Lanthanide precursors and deposition of lanthanide-containing films using the same

Abstract

Lanthanide-containing film forming compositions comprising Lanthanide precursors having the general formulae: ##STR00001##
wherein Ln is a Lanthanide; A is independently N, Si, B, P or O; each E is independently C, Si, B or P; m and n are independently 0, 1 or 2; m+n>1; each R is independently an H or a C.sub.1-C.sub.4 hydrocarbyl group; L is a −1 anionic ligand selected from the group consisting of NR′.sub.2, OR′, Cp, amidinate, β-diketonate, or keto-iminate, wherein R′ is an H or a C.sub.1-C.sub.4 hydrocarbon group; and L′ is NR″ or O, wherein R″ is an H or a C.sub.1-C.sub.4 hydrocarbon group. Also disclosed are methods of synthesizing and using the disclosed precursors to deposit Lanthanide-containing films on one or more substrates via vapor deposition processes.

Claims

1. A method of forming a Lanthanide-containing film on a substrate, the method comprising the steps of: introducing the Lanthanide precursor into a reactor having a substrate disposed therein; and depositing at least part of the Lanthanide precursor onto the substrate to form the Lanthanide-containing film on the substrate using a vapor deposition process, wherein the Lanthanide precursor has the general formulae:
L-Ln-C.sub.5R.sub.4—[(ER.sub.2).sub.m-(ER.sub.2).sub.n-L′]-,
L-Ln-C.sub.4AR.sub.3-3-[(ER.sub.2).sub.m-(ER.sub.2).sub.n-L′]-,
L-Ln-C.sub.3(m-A.sub.2)R.sub.2-4-[(ER.sub.2).sub.m-(ER.sub.2).sub.n-L′]-, referring to the following structure formula, respectively: ##STR00007## wherein Ln is selected from Lanthanide elements consisting of La, Y, Sc, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu bonded in an η.sup.5 bonding mode to the aromatic group; A is independently N, Si, B, P or O; each E is independently C or Si; m and n are independently 0, 1 or 2; m+n>1; each R is independently an H or a C.sub.1-C.sub.4 hydrocarbyl group; each L is independently a −1 anionic ligand, wherein the −1 anionic ligand is selected from the group consisting of NR′.sub.2, OR′, Cp, Amidinate, β-diketonate, and keto-iminate, wherein R′ is an H or a C.sub.1-C.sub.4 hydrocarbon group; each L′ is independently NR″, wherein R″ is an H or a C.sub.1-C.sub.4 hydrocarbon group; and each of R.sub.2, R.sub.3 and R.sub.4 is an H or a C.sub.1-C.sub.4 hydrocarbyl group.

2. The method of claim 1, further comprising introducing a reactant species into the reactor.

3. The method of claim 2, wherein the reactant species is selected from the group consisting of O.sub.2, O.sub.3, H.sub.2O, H.sub.2O.sub.2, acetic acid, formalin, para-formaldehyde, and combinations thereof.

4. The method of claim 3, wherein the reactant species is ozone.

5. The method of claim 1, wherein the Lanthanide precursor is selected from the group consisting of (Me.sub.2N)-La—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Y—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Sc—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Ce—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Pr—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Nd—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Sm—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Eu—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Gd—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Tb—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Dy—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Ho—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Er—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Tm—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Yb—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-, (Me.sub.2N)—Lu—C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—NMe)-.

6. The method of claim 5, wherein the deposition process is an atomic layer deposition process.

7. The method of claim 1, further comprising introducing a precursor into the reactor, wherein the precursor is different from the Lanthanide precursor, and depositing at least part of the precursor to form the Lanthanide-containing film on the substrate.

8. The method of claim 7, wherein the precursor contains an element selected from the group consisting of Hf, Si, Al, Ga, Mn, Ti, Ta, Bi, Zr, Pb, Nb, Mg, Sr, Ba, Ca, and combinations thereof.

9. The method of claim 1, wherein the deposition process is a chemical vapor deposition process.

10. The method of claim 1, wherein the deposition process is an atomic layer deposition process.

Description

DESCRIPTION OF PREFERRED EMBODIMENTS

(1) Lanthanide-containing film forming compositions are disclosed. The Lanthanide-containing film forming compositions comprise Lanthanide precursors having the general formulae,
L-Ln-C.sub.5H.sub.4—[(ER.sub.2).sub.m-(ER.sub.2).sub.n-L′]-,
L-Ln-(A-containing aromatic group)-[(ER.sub.2).sub.m-(ER.sub.2).sub.n-L′]-,
wherein Ln is selected from Lanthanide elements consisting of La, Y, Sc, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu bonded in an η.sup.5 bonding mode to the aromatic group; A-containing aromatic group contains one or two As wherein the two As are at ortho- or meta-positions; A is independently N, Si, B, P or O; each E is independently C, Si, B or P; m and n are independently 0, 1 or 2; m+n>1; each R is independently an H or a C.sub.1-C.sub.4 hydrocarbyl group; adjacent Rs may be joined to form a hydrocarbyl ring; each L is independently a −1 anionic ligand selected from the group consisting of NR′.sub.2, OR′, Cp, amidinate, β-diketonate, or keto-iminate, wherein R′ is an H or a C.sub.1-C.sub.4 hydrocarbon group; adjacent R′s may joined to form a hydrocarbyl ring; and each L′ is independently NR″ or O, wherein R″ is an H or a C.sub.1-C.sub.4 hydrocarbon group; and adjacent R″s may joined to form a hydrocarbyl ring. One of ordinary skill in the art would recognize that the A-containing aromatic group is a heterocyclic cyclic group containing N, Si, B, P or O and may have a symmetric or asymmetric structure.

(2) The Lanthanide-containing film forming compositions further comprise the Lanthanide precursors having the following formulae:
L-Ln-C.sub.5R.sub.4—[(ER.sub.2).sub.m-(ER.sub.2).sub.n-L′]-,
L-Ln-C.sub.4AR.sub.3-3-[(ER.sub.2).sub.m-(ER.sub.2).sub.n-L′]-,
L-Ln-C.sub.3(m-A.sub.2)R.sub.2-4-[(ER.sub.2).sub.m-(ER.sub.2).sub.n-L′]-,
referring to the following structure formula, respectively:

(3) ##STR00005##
wherein Ln is selected from Lanthanide elements consisting of La, Y, Sc, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu bonded in an η.sup.5 bonding mode to the aromatic group; A is independently N, Si, B, P or O; each E is independently C, Si, B or P; m and n are independently 0, 1 or 2; m+n>1; each R is independently an H or a C.sub.1-C.sub.4 hydrocarbyl group; and adjacent Rs may be joined to form a hydrocarbyl ring; each L is independently a −1 anionic ligand selected from the group consisting of NR′.sub.2, OR′, Cp, amidinate, β-diketonate, or keto-iminate, wherein R′ is an H or a C.sub.1-C.sub.4 hydrocarbon group; and adjacent R′s may be joined to form a hydrocarbyl ring; and each L′ is independently NR″ or O, wherein R″ is an H or a C.sub.1-C.sub.4 hydrocarbon group and adjacent R″s may be joined to form a hydrocarbyl ring.

(4) Exemplary Ln-containing precursors wherein E is C; A is N; m+n=2; and each R is independently hydrogen or a hydrocarbon group having up to 4 carbon atoms include but are not limited to (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.iPr.sub.2N)- Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (Cp)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (HO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (MeO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (EtO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (Cp)-Ln-C.sub.5H.sub.4[(CH.sub.2).sub.2—NMe]-, (HO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (MeO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (EtO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (Et.sub.2)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.nPr.sub.2)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (Cp)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (HO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (MeO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (EtO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPr.sub.2N)- Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBu.sub.2)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (CP)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPrO)-Ln- C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu ]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPr.sub.2)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.iPr.sub.2N)-Ln- C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (Cp)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (HO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (MeO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (EtO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CH.sub.2).sub.2—O]—, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2- N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2- N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln- C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2- N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (HO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2- O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.4—[(CMe.sub.2).sub.2-O]—, (H.sub.2N)- Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (Cp)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (HO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (MeO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (EtO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NH]—, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (HO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NMe]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (HO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—NEt]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (Cp)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (HO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (MeO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (EtO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPrO)- Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (Cp)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (HO)-Ln- C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (MeO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (EtO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (HO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBuO)-Ln- C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (Et.sub.2N)-Ln- C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (HO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBuO)-Ln- C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (HO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (HO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBuO)-Ln- C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (Cp)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (HO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (MeO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (EtO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CH.sub.2).sub.2—O]—, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln- C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4- [(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2- N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln- C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Et.sub.sN)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)- Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4- [(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2- N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln- C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln- C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln- C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln- C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (HO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.5Me.sub.4-[(CMe.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.nBu.sub.2N)- Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.sBu.sub.2N)- Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me- 3-[(CH.sub.2).sub.2—NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (Me.sub.2N)- Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iBuO)- Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me- 3-[(CH.sub.2).sub.2—N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBuO)- Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBuO)- Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me- 3-[(CH.sub.2).sub.2—N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBuO)- Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBuO)- Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3- 1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3- 1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3- 1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3- 1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3- 1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]- , (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]- , (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.iBu]- , (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPrO)-Ln- C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.2-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1- Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3- 1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3- 1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]- , (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]- , (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me- 3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me- 3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CMe.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln- C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2- N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2- N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln- C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1- Me-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me- 3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2- N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2- N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)- Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.iBuO)- Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(CEt.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me- 3-[(C.sup.iPr.sub.2).sub.2—NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iBuO)- Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.tBuO)- Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me- 3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me- 3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (Cp)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3- [(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.iPr.sub.2).sub.2—O]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me- 3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln- C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me- 3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-Me- 3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (HO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nPrO)- Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-Me-3-[(C.sup.tBu.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (Cp)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (.sup.tBuO)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iBuO)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (.sup.tBuO)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (EtO)-Ln-C.sub.5H.sub.3- 1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (Et.sub.2N)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (MeO)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPrO)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.iPrO)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CH.sub.2).sub.2—O]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr- 3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr- 3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr- 3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CMe.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr- 3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr- 3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr- 3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2- N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(CEt.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.tBuO)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3- [(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3- [(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (MeO)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.iPr.sub.2).sub.2—O]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3- 1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr- 3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln- C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)- Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3- [(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (HO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.5H.sub.3-1- .sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.5H.sub.3-1-.sup.iPr-3-[(C.sup.tBu.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (MeO)-Ln- C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NH]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NMe]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—NEt]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln- C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3- [(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]- , (HO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBuO)-Ln- C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.iBu]-, (H.sub.2N)-Ln- C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3- [(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBuO)-Ln- C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3- [(CH.sub.2).sub.2—N.sup.tBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBuO)-Ln- C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3- 3-[(CH.sub.2).sub.2—O]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (Cp)- Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CH.sub.2).sub.2—O]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2- NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)- Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)- Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3- 3-[(CMe.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3- 3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)- Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Cp)- Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2- O]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CMe.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2- NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2- NH]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2- NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)- Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)- Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3- 3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln- C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Cp)- Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)- Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln- C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Cp)- Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln- C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(CEt.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3- 3-[(C.sup.iPr.sub.2).sub.2—NH]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.sBu.sub.2N)-Ln- C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NH]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iPrO)- Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3- 3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NMe]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iBuO)- Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3- 3-[(C.sup.iPr.sub.2).sub.2—NEt]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nBuO)- Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3- 3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3- 3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3- [(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nPrO)- Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (EtO)-Ln-C.sub.4NH.sub.3- 3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.tBu.sub.2N)-Ln- C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.tBuO)- Ln-C.sub.4NH.sub.3-3-[(C.sup.iPr.sub.2).sub.2—O]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3- [(C.sup.tBu.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln- C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)- Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.4NH.sub.3- 3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (HO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.sBuO)-Ln- C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.4NH.sub.3-3-[(C.sup.tBu.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NH]—, (H.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (EtO)-Ln-C.sub.3-(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NMe]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CH.sub.2).sub.2—NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CH.sub.2).sub.2—NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (.sup.iPrO)-Ln- C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (.sup.tBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—NEt]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPr.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (MeO)-Ln- C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.nBuO)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.sBuO)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CH.sub.2).sub.2—N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CH.sub.2).sub.2—N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (Cp)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (.sup.tBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CH.sub.2).sub.2—O]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CMe.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CMe.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CMe.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln- C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln- C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln- C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln- C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln- C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CMe.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CEt.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CEt.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(CEt.sub.2).sub.2-O]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NH]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NMe]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—NEt]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.3-(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln- C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iPr.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.tBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.sBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iPr.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.tBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.sBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2- 4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m- N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.iPr.sub.2).sub.2—O]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NH]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]- , (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]- , (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NMe]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]- , (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.nBuO)-Ln- C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.sBuO)-Ln- C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-NEt]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (HO)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (EtO)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nPr]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (MeO)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iPr]—, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2- N.sup.nBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.nBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2- N.sup.iBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]- , (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.iBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2- N.sup.sBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2- N.sup.sBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.sBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2- N.sup.tBu]-, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.tBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]- , (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-N.sup.tBu]-, (H.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (Me.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (Et.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iPr.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.sBu.sub.2N)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.tBu.sub.2N)- Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (Cp)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (HO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (MeO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (EtO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iPrO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.nBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.iBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, (.sup.sBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, and (.sup.tBuO)-Ln-C.sub.3(m-N.sub.2)H.sub.2-4-[(C.sup.tBu.sub.2).sub.2-O]—, wherein Ln is selected from Lanthanide elements consisting of La, Y, Sc, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu bonded in an η.sup.5 bonding mode to the aromatic group; N may be replaced with Si, B, P, or O; and bridged C may be replaced with Si, B or P.

(5) Preferred Lanthanide precursors include (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2)—NMe)- and (Me.sub.2N)-Ln-C.sub.5H.sub.3-1-Me-3-(CH.sub.2—CH.sub.2—O)—, corresponding to the following structure formula, respectively:

(6) ##STR00006##
wherein Ln is selected from Lantanide elements consisting of La, Y, Sc, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu bonded in an η.sup.5 bonding mode to the aromatic group. Specific compounds include: (Me.sub.2N)—La—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]—, (Me.sub.2N)—Y—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Sc—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Ce—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Pr—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Nd—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Sm—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Eu—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Gd—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Tb—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Dy—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Ho—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Er—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Tm—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Yb—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—Lu—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-, (Me.sub.2N)—La—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Y—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Sc—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Ce—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Pr—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Nd—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Sm—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Eu—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Gd—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Tb—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Dy—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Ho—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Er—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Tm—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, (Me.sub.2N)—Yb—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—, and (Me.sub.2N)—Lu—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—.

(7) Alternatively, the compounds include Cp-La—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Y—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Sc—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Ce—C.sub.5H.sub.3-1-Me- 3-[(CH.sub.2).sub.2—NMe]-; Cp-Pr—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Nd—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Sm—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Eu—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Gd—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Tb—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Dy—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Ho—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Er—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Tm—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Yb—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-Lu—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—NMe]-; Cp-La—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Y—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Sc—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Ce—C.sub.5H.sub.3-1- Me-3-[(CH.sub.2).sub.2—O]—; Cp-Pr—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Nd—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Sm—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Eu—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Gd—C.sub.5H.sub.3-1- Me-3-[(CH.sub.2).sub.2—O]—; Cp-Tb—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Dy—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Ho—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Er—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; Cp-Tm—C.sub.5H.sub.3-1- Me-3-[(CH.sub.2).sub.2—O]—; Cp-Yb—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—; and Cp-Lu—C.sub.5H.sub.3-1-Me-3-[(CH.sub.2).sub.2—O]—.

(8) The inventors recognize that the disclosed Lanthanide-containing precursors having the above structures, i.e., having one aromatic group with asymmetric structure may be liquid and less or not viscous. With smaller ligands the disclosed Lanthanide-containing precursors having the above structures may have high vapor pressure and may be used in direct liquid injection (DLI) where the precursor is fed in a liquid state and then vaporized before it is introduced into a reactor. In addition, bridged aromatic groups, for example, cyclopentadienyl (Cp)/amino or bridged Cp/alkoxy, may help to stabilize the compounds.

(9) The Lanthanide precursors offer unique physical and chemical properties when compared to their corresponding homoleptic compounds, which include tris-substituted cyclopentadienyl Lanthanum compounds, La(RCp).sub.3, tris-acetamidinate compounds, La(R—N—C(R′)═N—R).sub.3, or tris-formamidinate compounds, La(R—N—C(H)═N—R).sub.3. Such properties include better control of steric crowding around the metal center, which in turn controls the surface reaction on the substrate and the reaction with a second reactant (such as an oxygen source). Independently fine tuning the substituents on the ligands increases volatility and thermal stability and decreases melting point to yield either liquids or low melting solids.

(10) In order to synthesize stable Lanthanide precursors with properties suited for the vapor deposition process (i.e., a volatile, yet thermally stable, liquid or low melting solid (having a melting point below about 105° C.)), a direct correlation between the properties of the central metal ion (coordination number) and ligands (steric effect, ratio of two heteroleptic ligands) has been observed. Preferably, the metal compound has a 3+ charge and coordination number of 6. Preferably m is 2 and n is 1. Preferably the Lanthanide precursor has a melting point below about 105° C., preferably below about 80° C., more preferably below about 70° C., and even more preferably below about 40° C.

(11) The synthesis of the lanthanide precursors may be carried out by following methods:

(12) Method A

(13) By reacting at low temperature Ln(RCp).sub.2X (X═Cl, Br or I) with the corresponding alkanolamine and/or alkylamine in a suitable solvent, such as dichloromethane, THF or ether, where R is defined above. The alkanolamine and alkylamine are commercially available. After completion of the addition, the mixture warms to room temperature with stirring. The solvent is removed under vacuum. The residue is dissolved in a solvent, such as toluene. The resulting mixture is filtered. Removal of the solvent produces the lanthanide precursor.

(14) Method B

(15) By reacting Ln(RCp).sub.3 at low temperature with the corresponding alkanolamine in a suitable solvent, such as heptanes, dichloromethane, THF or ether, where R is defined above. The alkanolamine is commercially available. After completion of the addition, the mixture warms to room temperature with stirring. The solvent is removed under vacuum to produce the lanthanide precursor.

(16) Method C

(17) In-situ reacting LnX.sub.3 (where X═Cl, Br, I) (in a stepwise reaction without isolation of intermediate products) with a stoichiometric amount of RCpM (where R is selected from H or a C.sub.1-C.sub.4 alkyl chain; and M=Li, Na, K) followed by filtration, and reacting the filtrate with alkanolamine and/or alkylamine to result in lanthanide precursor.

(18) A portion of the disclosed precursor compounds (hereinafter the “Lanthanide precursor”) may be deposited to form Lanthanide-containing films using any vapor deposition methods known to those of skill in the art. Examples of suitable vapor deposition methods include without limitation, conventional chemical vapor deposition (CVD), atomic layer deposition (ALD), or other types of vapor depositions that are variations thereof, such as plasma enhanced ALD (PEALD), plasma enhanced CVD (PECVD), low pressure CVD (LPCVD), pulsed chemical vapor deposition (P-CVD), low pressure CVD (LPCVD), sub-atmospheric CVD (SACVD), atmospheric pressure CVD (APCVD), hot-wire CVD (HWCVD, also known as cat-CVD, in which a hot wire serves as an energy source for the deposition process), thermal ALD, thermal CVD, spatial ALD, hot-wire ALD (HWALD), radicals incorporated deposition, and super critical fluid deposition, or combinations thereof. The deposition method is preferably ALD, PE-ALD, or spatial ALD in order to provide suitable step coverage and film thickness control.

(19) The type of substrate upon which the Lanthanide-containing film will be deposited will vary depending on the final use intended. In some embodiments, the substrate may be chosen from oxides which are used as dielectric materials in MIM, DRAM, FeRam technologies or gate dielectrics in CMOS technologies (for example, HfO.sub.2 based materials, TiO.sub.2 based materials, GeO.sub.2 based materials, ZrO.sub.2 based materials, rare earth oxide based materials, ternary oxide based materials, etc.) or from nitride-based films (for example, TaN) that are used as an oxygen barrier between copper and the low-k layer. Other substrates may be used in the manufacture of semiconductors, photovoltaics, LCD-TFT, or flat panel devices. Examples of such substrates include, but are not limited to, solid substrates such as metal substrates (for example, Au, Pd, Rh, Ru, W, Al, Ni, Ti, Co, Pt and metal silicides, such as TiSi.sub.2, CoSi.sub.2, and NiSi.sub.2); metal nitride containing substrates (for example, TaN, TiN, WN, TaCN, TiCN, TaSiN, and TiSiN); semiconductor materials (for example, Si, SiGe, GaAs, InP, diamond, GaN, and SiC); insulators (for example, SiO.sub.2, Si.sub.3N.sub.4, SiON, HfO.sub.2, Ta.sub.2O.sub.5, ZrO.sub.2, TiO.sub.2, Al.sub.2O.sub.3, and barium strontium titanate); or other substrates that include any number of combinations of these materials. Plastic substrates, such as poly(3,4-ethylenedioxythiophene)poly(styrenesulfonte) [PEDOT:PSS], may also be used. The actual substrate utilized may also depend upon the specific precursor embodiment utilized. In many instances though, the preferred substrate utilized will be selected from TiN, Ru, and Si type substrates.

(20) The vapor of the Lanthanide precursor is introduced into a reactor containing at least one substrate. The temperature and the pressure within the reactor and the temperature of the substrate are held at conditions suitable for vapor deposition of at least part of the Lanthanide precursor onto the substrate. In other words, after introduction of the vaporized precursor into the reactor, conditions within the chamber are such that at least part of the vaporized precursor is deposited onto the substrate to form the Lanthanide-containing film. The reactor may be any enclosure or chamber of a device in which deposition methods take place, such as, without limitation, a parallel-plate type reactor, a cold-wall type reactor, a hot-wall type reactor, a single-wafer reactor, a multi-wafer reactor, or other such types of deposition systems.

(21) The reactor may be maintained at a pressure ranging from about 0.5 mTorr to about 20 Torr. In addition, the temperature within the reactor may range from about 250° C. to about 600° C. One of ordinary skill in the art will recognize that the temperature may be optimized through mere experimentation to achieve the desired result.

(22) The substrate may be heated to a sufficient temperature to obtain the desired Lanthanide-containing film at a sufficient growth rate and with desired physical state and composition. A non-limiting exemplary temperature range to which the substrate may be heated includes from 150° C. to 600° C. Preferably, the temperature of the substrate remains less than or equal to 450° C.

(23) The Lanthanide precursor may be fed in liquid state to a vaporizer where it is vaporized before it is introduced into the reactor. Prior to its vaporization, the Lanthanide precursor may optionally be mixed with one or more solvents, one or more metal sources, and a mixture of one or more solvents and one or more metal sources. The solvents may be selected from the group consisting of toluene, ethyl benzene, xylene, mesitylene, decane, dodecane, octane, hexane, pentane, or others. The resulting concentration may range from approximately 0.05 M to approximately 2 M. The metal source may include any metal precursors now known or later developed.

(24) Alternatively, the Lanthanide precursor may be vaporized by passing a carrier gas into a container containing the Lanthanide precursor or by bubbling the carrier gas into the Lanthanide precursor. Again, the carrier gas may include, but is not limited to, Ar, He, N.sub.2, and mixtures thereof. The carrier gas and Lanthanide precursor are then introduced into the reactor. If necessary, the container may be heated to a temperature that permits the Lanthanide precursor to be in its liquid phase and to have a sufficient vapor pressure. The carrier gas may include, but is not limited to, Ar, He, N.sub.2, and mixtures thereof. The Lanthanide precursor may optionally be mixed in the container with a solvent, another precursor, or a mixture thereof. The container may be maintained at temperatures in the range of, for example, 0-100° C. Those skilled in the art recognize that the temperature of the container may be adjusted in a known manner to control the amount of Lanthanide precursor vaporized.

(25) In addition to the optional mixing of the Lanthanide precursor with solvents, metal precursors, and stabilizers prior to introduction into the reactor, the Lanthanide precursor may be mixed with reactant species inside the reactor. Exemplary reactant species include, without limitation, H.sub.2, metal precursors such as TMA or other aluminum-containing precursors, other Lanthanide precursors, TBTDET, TAT-DMAE, PET, TBTDEN, PEN, and any combination thereof.

(26) When the desired Lanthanide-containing film also contains oxygen, such as, for example and without limitation, lanthanum oxide, the reactant species may include an oxygen source which is selected from, but not limited to, O.sub.2, O.sub.3, H.sub.2O, H.sub.2O.sub.2, acetic acid, formalin, para-formaldehyde, and combinations thereof.

(27) When the desired Lanthanide-containing film also contains nitrogen, such as, for example and without limitation, lanthanum nitride or lanthanum carbo-nitride, the reactant species may include a nitrogen source which is selected from, but not limited to, nitrogen (N.sub.2), ammonia and alkyl derivatives thereof, hydrazine and alkyl derivatives thereof, N-containing radicals (for instance N., NH., NH.sub.2.) NO, N.sub.2O, NO.sub.2, amines, and any combination thereof.

(28) When the desired Lanthanide-containing film also contains carbon, such as, for example and without limitation, Lanthanum carbide or Lanthanum carbo-nitride, the reactant species may include a carbon source which is selected from, but not limited to, methane, ethane, propane, butane, ethylene, propylene, t-butylene, isobutylene, CCl.sub.4, and any combination thereof.

(29) When the desired Lanthanide-containing film also contains silicon, such as, for example and without limitation, Lanthanum silicide, Lanthanum silica-nitride, Lanthanum silicate, Lanthanum silica-carbo-nitride, the reactant species may include a silicon source which is selected from, but not limited to, SiH.sub.4, Si.sub.2H.sub.6, Si.sub.3H.sub.8, TriDMAS, BDMAS, BDEAS, TDEAS, TDMAS, TEMAS, (SiH.sub.3).sub.3N, (SiH.sub.3).sub.2O, trisilylamine, disiloxane, trisilylamine, disilane, trisilane, an alkoxysilane SiH.sub.x(OR.sup.1).sub.4-x, a silanol Si(OH).sub.x(OR.sup.1).sub.4-x (preferably Si(OH)(OR.sup.1).sub.3; more preferably Si(OH)(OtBu).sub.3 an aminosilane SiH.sub.x(NR.sup.1R.sup.2).sub.4-x (where x is 1, 2, 3, or 4; R.sup.1 and R.sup.2 are independently H or a linear, branched or cyclic C1-C6 carbon chain; preferably TriDMAS, BTBAS, and/or BDEAS), and any combination thereof. The targeted film may alternatively contain Germanium (Ge), in which case the above-mentioned Si-containing reactant species could be replaced by Ge-containing reactant species.

(30) When the desired Lanthanide-containing film also contains another element, such as, for example and without limitation, Ge, Ti, Ta, Hf, Zr, Nb, Mg, Al, Sr, Y, Ba, Ca, As, Sb, Bi, Sn, Pb, or combinations thereof, the reactant species may include a precursor which is selected from, but not limited to, alkyls such as SbR.sup.i′.sub.3 or SnR.sup.i′.sub.4 (wherein each R.sup.i′ is independently H or a linear, branched, or cyclic C1-C6 carbon chain), alkoxides such as Sb(OR.sup.i).sub.3 or Sn(OR.sup.i).sub.4 (where each R.sup.i is independently H or a linear, branched, or cyclic C1-C6 carbon chain), and amines such as Sb(NR.sup.1R.sup.2)(NR.sup.3R.sup.4)(NR.sup.5R.sup.6) or Ge(NR.sup.1R.sup.2)(NR.sup.3R.sup.4)(NR.sup.5R.sup.6)(NR.sup.7R.sup.8) (where each R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, and R.sup.8 is independently H, a C1-C6 carbon chain, or a trialkylsilyl group, the carbon chain and trialkylsilyl group each being linear, branched, or cyclic), and any combination thereof.

(31) The Lanthanide precursor and one or more reactant species may be introduced into the reactor simultaneously (chemical vapor deposition), sequentially (atomic layer deposition), or in other combinations. For example, the Lanthanide precursor may be introduced in one pulse and two additional metal sources may be introduced together in a separate pulse [modified atomic layer deposition]. Alternatively, the reactor may already contain the reactant species prior to introduction of the Lanthanide precursor. The reactant species may be passed through a plasma system localized remotely from the reactor, and decomposed to radicals. Alternatively, the Lanthanide precursor may be introduced to the reactor continuously while other reactant species are introduced by pulse (pulsed-chemical vapor deposition). In each example, a pulse may be followed by a purge or evacuation step to remove excess amounts of the component introduced. In each example, the pulse may last for a time period ranging from about 0.01 s to about 10 s, alternatively from about 0.3 s to about 3 s, alternatively from about 0.5 s to about 2 s.

(32) In one non-limiting exemplary atomic layer deposition type process, the vapor phase of a Lanthanide precursor is introduced into the reactor, where at least part of the Lanthanide precursor reacts with a suitable substrate in a self-limiting manner. Excess Lanthanide precursor may then be removed from the reactor by purging and/or evacuating the reactor. An oxygen source, such as ozone, is introduced into the reactor where it reacts with the absorbed Lanthanide precursor. Any excess oxygen source is removed from the reactor by purging and/or evacuating the reactor. If the desired film is a Lanthanide oxide film, this two-step process may provide the desired film thickness or may be repeated until a film having the necessary thickness has been obtained.

(33) LaGeO.sub.x, wherein x is a number ranging from 1 to 5 inclusive, may spontaneously form when the ALD LaO film is deposited on a Ge or GeO.sub.2 substrate. The LaGeO.sub.x film may serve as a channel material in metal oxide semiconductor (MOS) devices due to high hole mobility and low dopant activation temperatures.

(34) Alternatively, the LaO.sub.x film may be deposited as a capping layer on an HfO.sub.x or ZrO.sub.x high k gate dielectric film, with x being a number ranging from 1 to 5 inclusive. The LaO.sub.x capping layer reduces Fermi level pinning effects between the gate dielectric layer and a metal gate.

(35) In another alternative, if the desired film is a Lanthanide oxide film containing another element, the two-step process above may be followed by introduction of the vapor of a precursor into the reactor. The precursor will be selected based on the nature of the Lanthanide metal oxide film being deposited and may include a different Lanthanide precursor. After introduction into the reactor, the precursor is contacted with the substrate. Any excess precursor is removed from the reactor by purging and/or evacuating the reactor. Once again, an oxygen source may be introduced into the reactor to react with the precursor. Excess oxygen source is removed from the reactor by purging and/or evacuating the reactor. If a desired film thickness has been achieved, the process may be terminated. However, if a thicker film is desired, the entire four-step process may be repeated. By alternating the provision of the Lanthanide precursor, precursor, and oxygen source, a film of desired composition and thickness can be deposited.

(36) The Lanthanide-containing films or Lanthanide-containing layers resulting from the processes discussed above may include La.sub.2O.sub.3, (LaLn)O.sub.3, La.sub.2O.sub.3-Ln.sub.2O.sub.3, LaSi.sub.xO.sub.y, LaGe.sub.xO.sub.y, (Al, Ga, Mn)LnO.sub.3, HfLaO.sub.x or ZrLaO.sub.x, LaSrCoO.sub.4, LaSrMnO.sub.4 where Ln is a different Lanthanide and x is 1 to 5 inclusive. Preferably, the Lanthanide-containing film may include HfLaO.sub.x or ZrLaO.sub.x. One of ordinary skill in the art will recognize that by judicial selection of the appropriate Lanthanide precursor and reactant species, the desired film composition may be obtained.

(37) Upon obtaining a desired film thickness, the film may be subject to further processing, such as thermal annealing, furnace-annealing, rapid thermal annealing, UV or e-beam curing, and/or plasma gas exposure. Those skilled in the art recognize the systems and methods utilized to perform these additional processing steps. For example, the lanthanum-containing film may be exposed to a temperature ranging from approximately 200° C. and approximately 1000° C. for a time ranging from approximately 0.1 second to approximately 7200 seconds under an inert atmosphere, an H-containing atmosphere, a N-containing atmosphere, an O-containing atmosphere, or combinations thereof. Most preferably, the temperature is 350° C. for 1800 seconds under an inert atmosphere of Argon. The resulting film may contain fewer impurities and therefore may have an improved density resulting in improved leakage current. The annealing step may be performed in the same reactor in which the deposition process is performed. Alternatively, the substrate may be removed from the reactor, with the annealing/flash annealing process being performed in a separate apparatus. Any of the above post-treatment methods, but especially thermal annealing, has been found effective to reduce carbon and nitrogen contamination of the Lanthanide-containing film. This in turn tends to improve the leakage current and the interface trap density (D.sub.it) of the film.

(38) While embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and not limiting. Many variations and modifications of the composition and method are possible and within the scope of the invention. Accordingly the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims.