Catalysts and methods for polymer synthesis

Abstract

The present invention provides bimetallic complexes having increased activity in the copolymerization of carbon dioxide and epoxides. Also provided are methods of using such metal complexes in the synthesis of polymers. According to one aspect, the present invention provides metal complexes comprising an activating species with co-catalytic activity tethered to a multidentate ligand that is coordinated to one or more active metal centers of the complex.

Claims

1. A catalyst for the copolymerization of epoxides and CO.sub.2 comprising two or more metal atoms, one or more multidentate ligands, and at least one tethered activating moiety tethered to one or more of the ligands, wherein the metal atoms are complexed to the one or more multidentate ligands, wherein the catalyst has the following structure: ##STR00328## wherein: M.sup.1 is a first metal atom; M.sup.2 is a second metal atom; ##STR00329## comprises a multidentate ligand system capable of coordinating both metal atoms; represents one or more activating moieties attached to the multidentate ligand system, where is a linker moiety covalently coupled to the ligand system and contains 1-30 atoms including at least one carbon atom, and optionally one or more atoms selected from the group consisting of N, O, S, Si, B, and P, m is an integer from 1 to 4 representing the number of Z groups present on an individual linker moiety; and each (Z) is an activating functional group.

2. The catalyst of claim 1, comprising two metal atoms coordinated to one multidentate ligand.

3. The catalyst of claim 1, wherein an activating moiety is selected from the group consisting of neutral nitrogen-containing functional groups, cationic moieties, phosphorous-containing functional groups and two or more of these.

4. The catalyst of claim 3, wherein each (Z) is an activating functional group independently selected from the group consisting of: ##STR00330## ##STR00331## ##STR00332## ##STR00333## wherein: each R.sup.1 and R.sup.2 is independently hydrogen or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring; wherein R.sup.1 and R.sup.2 can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more additional heteroatoms; each R.sup.3 is independently hydrogen or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring; wherein an R.sup.3 group can be taken with an R.sup.1 or R.sup.2 group to form one or more optionally substituted rings; and each R.sup.4 is independently hydrogen, a hydroxyl protecting group, or an optionally substituted radical selected from the group consisting of C.sub.1-20 acyl; C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring; R.sup.5 is R.sup.2 or hydroxyl; wherein R.sup.1 and R.sup.5 can be taken together with intervening atoms to form one or more optionally substituted carbocyclic, heterocyclic, aryl, or heteroaryl rings; each R.sup.6 and R.sup.7 is independently hydrogen or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring; wherein R.sup.6 and R.sup.7 can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more heteroatoms, and an R.sup.6 and R.sup.7 group can be taken with an R.sup.1 or R.sup.2 group to form one or more optionally substituted rings; each occurrence of R.sup.8 is independently selected from the group consisting of: halogen, NO.sub.2, CN, SR.sup.y, S(O)R.sup.y, S(O).sub.2R.sup.y, NR.sup.yC(O)R.sup.y, OC(O)R.sup.y, CO.sub.2R.sup.y, NCO, N.sub.3, OR.sup.7, OC(O)N(R.sup.y).sub.2, N(R.sup.y).sub.2, NR.sup.yC(O)R.sup.y, NR.sup.yC(O)OR.sup.y; or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring; and where two or more adjacent R.sup.8 groups can be taken together to form an optionally substituted saturated, partially unsaturated, or aromatic 5- to 12-membered ring containing 0 to 4 heteroatoms; each R.sup.y is independently H, or an optionally substituted radical selected from the group consisting of C.sub.1-6 aliphatic, phenyl, a 3-7 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 5-6 membered heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and 8- to 10-membered aryl; X.sup. is any anion; Ring A is an optionally substituted, 5- to 10-membered heteroaryl group; and Ring B is an optionally substituted, 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 0-2 heteroatoms in addition to the depicted ring nitrogen atom independently selected from nitrogen, oxygen, or sulfur.

5. The catalyst of claim 4, wherein M.sup.1 and M.sup.2 are independently selected from the group consisting of Cr, Mn, V, Fe, Co, Mo, W, Ru, Al, and Ni.

6. The catalyst of claim 4, wherein M.sup.1 and M.sup.2 are Co.

7. The catalyst of claim 4, wherein the moiety is a C.sub.2-30 aliphatic group wherein one or more methylene units are optionally and independently replaced by NR.sup.y, N(R.sup.y)C(O), C(O)N(R.sup.y), O, C(O), OC(O), C(O)O, S, Si(R.sup.y).sub.2, SO, SO.sub.2, C(S), C(NR.sup.y), or NN, wherein each occurrence of R.sup.y is independently H, or an optionally substituted radical selected from the group consisting of C.sub.1-6 aliphatic, phenyl, a 3-7 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 5-6 membered heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and 8- to 10-membered aryl.

8. The catalyst of claim 4, wherein the moiety is selected from the group consisting of: ##STR00334## ##STR00335## wherein each s is independently 0-6, t is 0-4, * represents the site of attachment to a ligand, and each # represents a site of attachment of an activating functional group.

9. The catalyst of claim 4, wherein the ##STR00336## moiety comprises a hexadentate ligand.

10. The catalyst of claim 9, wherein the hexadentate ligand is selected from the group consisting of: ##STR00337## ##STR00338## wherein: Q.sup.1, Q.sup.2, Q.sup.3, Q.sup.3, Q.sup.4, Q.sup.5 and Q.sup.6 are each independently oxygen, nitrogen or sulfur atoms which may be optionally substituted if allowed by valency rules; each is optionally present and independently represents an optionally substituted bridge containing 2 to 20 carbon atoms, wherein such bridges can independently, or in combination, optionally form one or more optionally substituted rings, wherein each bridge present optionally contains one or more heteroatoms; each ##STR00339## moiety is independently an optionally substituted carbon bridge that is optionally unsaturated, where any carbon atoms comprising the bridge may be part of one or more optionally substituted rings; one or more groups is optionally substituted with one or more ; rings C and D each independently represent an optionally substituted 5- to 12-membered mono- or polycyclic ring that may be saturated, partially unsaturated or aromatic and may optionally contain one or more heteroatoms; each R.sup.a and R.sup.b is independently a substituent present on phenyl rings where two or more R.sup.a groups and/or two or more R.sup.b groups may be taken together to form one or more optionally substituted rings; each R.sup.c and R.sup.d is independently selected from the group consisting of: a group, halogen, OR.sup.7, N(R.sup.y).sub.2, SR.sup.7, CN, NO.sub.2, SO.sub.2R.sup.y, SOR, SO.sub.2N(R.sup.y).sub.2; CNO, NR.sup.ySO.sub.2R.sup.y, NCO, N.sub.3, SiR.sub.3; or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring; where two or more R.sup.c or R.sup.d groups may be taken together with the carbon atoms to which they are attached and any intervening atoms to form one or more optionally substituted rings; and where when two R.sup.c or R.sup.d groups are attached to the same carbon atom, they may be taken together with the carbon atom to which they are attached to form a moiety selected from the group consisting of: a 3- to 8-membered spirocyclic ring, a carbonyl group, an optionally substituted alkene, an optionally substituted oxime, an optionally substituted hydrazone, and an optionally substituted imine; each R.sup.e is independently selected from the group consisting of hydrogen; a group; or an optionally substituted moiety selected from the group consisting of: C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring; wherein if two R.sup.e groups are present on the same position, they may be taken together to form a spirocyclic ring optionally containing one or more heteroatoms and optionally substituted with one or more R.sup.e groups; R.sup.12 is optionally present, and if present is selected from the group consisting of: a group; or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; and phenyl; h and i are independently 1, 2, 3, or 4; and q is 1 or 2.

11. The catalyst of claim 10, wherein the catalyst comprises: ##STR00340## wherein: X.sup.1 and X.sup.2 are each independently an anion or a nucleophile capable of ring opening an epoxide; and where one or more activating moieties are present on the indicated phenyl ring in any one or more available positions as valency allows.

12. The catalyst of claim 10, wherein the catalyst comprises: ##STR00341## wherein: X.sup.1 and X.sup.2 are each independently an anion or a nucleophile capable of ring opening an epoxide; and where one or more activating moieties are present on the indicated phenyl ring in any one or more available positions as valency allows.

13. The catalyst of claim 10, wherein the catalyst comprises: ##STR00342## wherein: X.sup.1 and X.sup.2 are each independently an anion or a nucleophile capable of ring opening an epoxide.

14. The catalyst of claim 10, wherein the catalyst comprises: ##STR00343## wherein: X.sup.1 and X.sup.2 are each independently an anion or a nucleophile capable of ring opening an epoxide.

15. The catalyst of claim 10, wherein the catalyst comprises: ##STR00344## wherein: X.sup.1 and X.sup.2 are each independently an anion or a nucleophile capable of ring opening an epoxide.

16. The catalyst of claim 10, wherein the catalyst comprises: ##STR00345## wherein: X.sup.1 and X.sup.2 are each independently an anion or a nucleophile capable of ring opening an epoxide.

17. The catalyst of claim 10, wherein the catalyst comprises: ##STR00346## wherein each of X.sup.1 and X.sup.2, if present, independently an anion or a nucleophile capable of ring opening an epoxide.

18. The catalyst of claim 4, wherein the catalyst is selected from those in Table 1, wherein each M is independently a metal ion.

19. The catalyst of claim 18, wherein each M is cobalt.

20. The catalyst of claim 10, wherein one or more Z group is independently a neutral functional group selected from the group consisting of amines, phosphines, guanidines, bis-guanidines, amidines, and nitrogen-containing heterocycles.

21. The catalyst of any of claim 10, wherein M.sup.1 and M.sup.2 are cobalt.

22. The catalyst of claim 4, wherein the catalyst contains a total of 1 to 4 Z groups.

23. The catalyst of claim 4, wherein at least one Z group is selected from the group consisting of: ##STR00347## ##STR00348##

24. The catalyst of claim 4, wherein at least one Z group is selected from the group consisting of: ##STR00349##

25. The catalyst of claim 24, wherein two or more of R.sup.1, R.sup.2, and R.sup.3 are taken together to form an optionally substituted ring optionally containing additional heteroatoms.

26. The catalyst of claim 4, wherein at least one Z group is selected from the group consisting of: ##STR00350##

27. The catalyst of claim 26, wherein two or more of R.sup.1 and R.sup.2 are taken together to form one or more optionally substituted rings optionally containing additional heteroatoms.

28. The catalyst of claim 4, wherein at least one Z group is selected from the group consisting of: ##STR00351## ##STR00352##

29. The catalyst of claim 4, wherein at least one Z group is ##STR00353##

30. The catalyst of claim 29, wherein two or more of R.sup.1 and R.sup.2 are taken together to form one or more optionally substituted rings optionally containing additional heteroatoms.

Description

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

(1) The present invention encompasses the recognition that there remains a need for metal complexes useful in the copolymerization of epoxides and carbon dioxide. Metal complexes provided by the present invention can show significant advantages for uses in the copolymerization of epoxides and carbon dioxide. While not wishing to be bound by any particular theory, it is believed that metal complexes of the present invention provide enhanced reactivity and/or selectivity when compared to known metal complexes. In certain embodiments, a provided metal complex is highly selective for a copolymerization reaction, resulting in little or no cyclic carbonate formation. In certain embodiments, a provided metal complex is highly selective for polycarbonate formation.

(2) The present invention provides, among other things, metal complexes for the copolymerization of carbon dioxide and epoxides and methods of using the same. In certain embodiments, provided metal complexes contain two or more metal atoms. In certain embodiments, the metal atoms are complexed to one or more multidentate ligands and at least one tethered activating moiety tethered to one or more of the ligands. In some embodiments, an activating moiety comprises a linker and one or more activating functional groups. In certain embodiments, at least one activating functional group present on the tethered moiety can act as a polymerization co-catalyst and thereby increase the rate of the copolymerization. In some embodiments, provided metal complexes act as polymerization catalysts.

(3) In certain embodiments, the present invention provides multi-metal complexes and methods for using the same in the copolymerization of carbon dioxide and epoxides.

(4) In some embodiments, provided metal complexes have a structure C-1:

(5) ##STR00003##
wherein: M.sup.1 is a first metal atom; M.sup.2 is a second metal atom;

(6) ##STR00004##
comprises a multidentate ligand system capable of coordinating both metal atoms; represents one or more activating moieties attached to the multidentate ligand system, where is a linker moiety covalently coupled to the ligand system, each Z is an activating functional group; and m is an integer from 1 to 4 representing the number of Z groups present on an individual linker moiety.
II. Linker Moieties

(7) In certain embodiments, each activating moiety comprises a linker coupled to at least one activating functional group Z as described above, with m denoting the number of activating functional groups present on a single linker moiety.

(8) In some embodiments, there may be one or more activating moieties tethered to a given metal complex; similarly, each activating moiety itself may contain more than one activating functional group Z. In certain embodiments, each activating moiety contains only one activating functional group (i.e. m=1). In some embodiments, each activating moiety contains more than one activating functional groups (i.e. m>1). In certain embodiments, an activating moiety contains two activating functional groups (i.e. m=2). In certain embodiments, an activating moiety contains three activating functional groups (i.e. m=3). In certain embodiments, an activating moiety contains four activating functional groups (i.e. m=4). In certain embodiments where more than one activating functional group is present on an activating moiety, the activating functional groups are the same. In some embodiments where more than one activating functional group is present on an activating moiety, two or more of the activating functional groups are different.

(9) In certain embodiments, each linker moiety contains 1-30 atoms including at least one carbon atom, and optionally one or more atoms selected from the group consisting of N, O, S, Si, B, and P.

(10) In certain embodiments, a linker is an optionally substituted C.sub.2-30 aliphatic group wherein one or more methylene units are optionally and independently replaced by -Cy-, NR.sup.y, N(R.sup.y)C(O), C(O)N(R.sup.y), O, C(O), OC(O), C(O)O, S, SO, SO.sub.2, C(S), C(NR.sup.y), or NN, wherein: each -Cy- is independently an optionally substituted 5-8 membered bivalent, saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an optionally substituted 8-10 membered bivalent saturated, partially unsaturated, or aryl bicyclic ring having 0-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; and each R.sup.y is independently H, or an optionally substituted radical selected from the group consisting of C.sub.1-6 aliphatic, phenyl, a 3-7 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 5-6 membered heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and 8- to 10-membered aryl.

(11) In certain embodiments, a linker moiety is a C.sub.4-C.sub.12 aliphatic group substituted with one or more moieties selected from the group consisting of halogen, NO.sub.2, CN, SR, S(O)R.sup.y, S(O).sub.2R.sup.y, NR.sup.yC(O)R.sup.y, OC(O)R.sup.y, CO.sub.2R.sup.y, NCO, N.sub.3, OR.sup.4, OC(O)N(R.sup.y).sub.2, N(R.sup.y).sub.2, NR.sup.yC(O)R.sup.y, and NR.sup.yC(O)OR.sup.y, where each R.sup.y and R.sup.4 is independently as defined above and described in classes and subclasses herein.

(12) In certain embodiments, a linker moiety is an optionally substituted C.sub.3-C.sub.30 aliphatic group. In certain embodiments, a linker is an optionally substituted C.sub.4-24 aliphatic group. In certain embodiments, a linker moiety is an optionally substituted C.sub.4-C.sub.20 aliphatic group. In certain embodiments, a linker moiety is an optionally substituted C.sub.4-C.sub.12 aliphatic group. In certain embodiments, a linker is an optionally substituted C.sub.4-10 aliphatic group. In certain embodiments, a linker is an optionally substituted C.sub.4-8 aliphatic group. In certain embodiments, a linker moiety is an optionally substituted C.sub.4-C.sub.6 aliphatic group. In certain embodiments, a linker moiety is an optionally substituted C.sub.6-C.sub.12 aliphatic group. In certain embodiments, a linker moiety is an optionally substituted C.sub.8 aliphatic group. In certain embodiments, a linker moiety is an optionally substituted C.sub.7 aliphatic group. In certain embodiments, a linker moiety is an optionally substituted C.sub.6 aliphatic group. In certain embodiments, a linker moiety is an optionally substituted C.sub.5 aliphatic group. In certain embodiments, a linker moiety is an optionally substituted C.sub.4 aliphatic group. In certain embodiments, a linker moiety is an optionally substituted C.sub.3 aliphatic group. In certain embodiments, a aliphatic group in the linker moiety is an optionally substituted straight alkyl chain. In certain embodiments, the aliphatic group is an optionally substituted branched alkyl chain. In some embodiments, a linker moiety is a C.sub.4 to C.sub.20 alkyl group having one or more methylene groups replaced by C(R.sup.).sub.2 wherein R.sup. is as defined above. In certain embodiments, a linker moiety consists of a bivalent aliphatic group having 4 to 30 carbons including one or more C.sub.1-4 alkyl substituted carbon atoms. In certain embodiments, a linker moiety consists of a bivalent aliphatic group having 4 to 30 carbons including one or more gem-dimethyl substituted carbon atoms.

(13) In certain embodiments, a linker moiety includes one or more optionally substituted cyclic elements selected from the group consisting of saturated or partially unsaturated carbocyclic, aryl, heterocyclic, or heteroaryl. In certain embodiments, a linker moiety consists of the substituted cyclic element, in some embodiments the cyclic element is part of a linker with one or more non-ring heteroatoms or optionally substituted aliphatic groups comprising other parts of the linker moiety.

(14) In some embodiments, a linker moiety is of sufficient length to allow one or more activating functional groups to be positioned near a metal atom of a metal complex. In certain embodiments, structural constraints are built into a linker moiety to control the disposition and orientation of one or more activating functional groups near a metal center of a metal complex. In certain embodiments, such structural constraints are selected from the group consisting of cyclic moieties, bicyclic moieties, bridged cyclic moieties and tricyclic moieties. In some embodiments, such structural constraints are the result of acyclic steric interactions. In certain embodiments, steric interactions due to syn-pentane, gauche-butane, and/or allylic strain in a linker moiety, bring about structural constraints that affect the orientation of a linker and one or more activating groups. In certain embodiments, structural constraints are selected from the group consisting of cis double bonds, trans double bonds, cis allenes, trans allenes, and triple bonds. In some embodiments, structural constraints are selected from the group consisting of substituted carbons including geminally disubstituted groups such as spirocyclic rings, gem dimethyl groups, gem diethyl groups and gem diphenyl groups. In certain embodiments, structural constraints are selected from the group consisting of heteroatom-containing functional groups such as sulfoxides, amides, and oximes.

(15) In certain embodiments, linker moieties are selected from the group consisting of:

(16) ##STR00005## ##STR00006##

(17) wherein each s is independently 0-6, t is 0-4, R.sup.y as defined above and described in classes and subclasses herein, * represents the site of attachment to a ligand, and each # represents a site of attachment of an activating functional group.

(18) In some embodiments, s is 0. In some embodiments, s is 1. In some embodiments, s is 2. In some embodiments, s is 3. In some embodiments, s is 4. In some embodiments, s is 5. In some embodiments, s is 6.

(19) In some embodiments, t is 1. In some embodiments, t is 2. In some embodiments, t is 3. In some embodiments, t is 4.

(20) II. Activating Functional Groups

(21) In some embodiments, an activating functional group is selected from the group consisting of neutral nitrogen-containing functional groups, cationic moieties, phosphorous-containing functional groups, and combinations of two or more of these.

(22) II.a. Neutral Nitrogen-Containing Activating Groups

(23) In some embodiments, one or more tethered activating functional groups on provided metal complexes are neutral nitrogen-containing moieties. In some embodiments, such moieties include one or more of the structures in Table Z-1:

(24) TABLE-US-00001 TABLE Z-1 0 0

(25) or a combination of two or more of these,

(26) wherein:

(27) each R.sup.1 and R.sup.2 is independently hydrogen or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, phenyl; or an 8- to 14-membered polycyclic aryl ring; wherein R.sup.1 and R.sup.2 can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more additional heteroatoms; each R.sup.3 is independently hydrogen or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring; wherein an R.sup.3 group can be taken with an R.sup.1 or R.sup.2 group to form one or more optionally substituted rings; and each R.sup.4 is independently hydrogen, a hydroxyl protecting group, or an optionally substituted radical selected from the group consisting of C.sub.1-20 acyl; C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, phenyl; or an 8- to 14-membered polycyclic aryl ring.

(28) In certain embodiments, each R.sup.1 group is the same. In other embodiments, R.sup.1 groups are different. In certain embodiments, R.sup.1 is hydrogen. In some embodiments, R.sup.1 is an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic, 5- to 14-membered heteroaryl, phenyl, 8- to 10-membered aryl and 3- to 7-membered heterocyclic. In some embodiments, R.sup.1 is an optionally substituted radical selected from the group consisting of a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring.

(29) In certain embodiments, R.sup.1 is an optionally substituted radical selected from the group consisting of C.sub.1-12 aliphatic and C.sub.1-12 heteroaliphatic. In some embodiments, R.sup.1 is optionally substituted C.sub.1-20 aliphatic. In some embodiments, R.sup.1 is optionally substituted C.sub.1-12 aliphatic. In some embodiments, R.sup.1 is optionally substituted C.sub.1-6 aliphatic. In some embodiments, R.sup.1 is optionally substituted C.sub.1-20 heteroaliphatic. In some embodiments, R.sup.1 is optionally substituted C.sub.1-12 heteroaliphatic. In some embodiments, R.sup.1 is optionally substituted phenyl. In some embodiments, R.sup.1 is optionally substituted 8- to 10-membered aryl. In some embodiments, R.sup.1 is an optionally substituted 5- to 6-membered heteroaryl group. In some embodiments, R.sup.1 is an optionally substituted 8- to 14-membered polycyclic heteroaryl group. In some embodiments, R.sup.1 is optionally substituted 3- to 8-membered heterocyclic.

(30) In certain embodiments, each R.sup.1 is independently hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, optionally substituted phenyl, or optionally substituted benzyl. In certain embodiments, R.sup.1 is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, phenyl or benzyl. In some embodiments, R.sup.1 is butyl. In some embodiments, R.sup.1 is isopropyl. In some embodiments, R.sup.1 is neopentyl. In some embodiments, R.sup.1 is perfluoro. In some embodiments, R.sup.1 is CF.sub.2CF.sub.3. In some embodiments, R.sup.1 is phenyl. In some embodiments, R.sup.1 is benzyl.

(31) In certain embodiments, each R.sup.2 group is the same. In other embodiments, R.sup.2 groups are different. In certain embodiments, R.sup.2 is hydrogen. In some embodiments, R.sup.2 is an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic, 5- to 14-membered heteroaryl, phenyl, 8- to 10-membered aryl and 3- to 7-membered heterocyclic. In some embodiments, R.sup.2 is an optionally substituted radical selected from the group consisting of a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring.

(32) In certain embodiments, R.sup.2 is an optionally substituted radical selected from the group consisting of C.sub.1-12 aliphatic and C.sub.1-12 heteroaliphatic. In some embodiments, R.sup.2 is optionally substituted C.sub.1-20 aliphatic. In some embodiments, R.sup.2 is optionally substituted C.sub.1-12 aliphatic. In some embodiments, R.sup.2 is optionally substituted C.sub.1-6 aliphatic. In some embodiments, R.sup.2 is optionally substituted C.sub.1-20 heteroaliphatic. In some embodiments, R.sup.2 is optionally substituted C.sub.1-12 heteroaliphatic. In some embodiments, R.sup.2 is optionally substituted phenyl. In some embodiments, R.sup.2 is optionally substituted 8- to 10-membered aryl. In some embodiments, R.sup.2 is an optionally substituted 5- to 6-membered heteroaryl group. In some embodiments, R.sup.2 is an optionally substituted 8- to 14-membered polycyclic heteroaryl group. In some embodiments, R.sup.2 is optionally substituted 3- to 8-membered heterocyclic.

(33) In certain embodiments, each R.sup.2 is independently hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, optionally substituted phenyl, or optionally substituted benzyl. In certain embodiments, R.sup.2 is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, phenyl or benzyl. In some embodiments, R.sup.2 is butyl. In some embodiments, R.sup.2 is isopropyl. In some embodiments, R.sup.2 is neopentyl. In some embodiments, R.sup.2 is perfluoro. In some embodiments, R.sup.2 is CF.sub.2CF.sub.3. In some embodiments, R.sup.2 is phenyl. In some embodiments, R.sup.2 is benzyl.

(34) In certain embodiments, each R.sup.1 and R.sup.2 are hydrogen. In some embodiments, each R.sup.1 is hydrogen each and each R.sup.2 is other than hydrogen. In some embodiments, each R.sup.2 is hydrogen each and each R.sup.1 is other than hydrogen.

(35) In certain embodiments, R.sup.1 and R.sup.2 are both methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, phenyl or benzyl. In some embodiments, R.sup.1 and R.sup.2 are each butyl. In some embodiments, R.sup.1 and R.sup.2 are each isopropyl. In some embodiments, R.sup.1 and R.sup.2 are each perfluoro. In some embodiments, R.sup.1 and R.sup.2 are CF.sub.2CF.sub.3. In some embodiments, R.sup.1 and R.sup.2 are each phenyl. In some embodiments, R.sup.1 and R.sup.2 are each benzyl.

(36) In some embodiments, R.sup.1 and R.sup.2 are taken together with intervening atoms to form one or more optionally substituted carbocyclic, heterocyclic, aryl, or heteroaryl rings. In certain embodiments, R.sup.1 and R.sup.2 are taken together to form a ring fragment selected from the group consisting of: C(R.sup.y).sub.2, C(R.sup.y).sub.2C(R.sup.y).sub.2, C(R.sup.y).sub.2C(R.sup.y).sub.2C(R.sup.y).sub.2, C(R.sup.y).sub.2OC(R.sup.y).sub.2, and C(R.sup.y).sub.2NR.sup.yC(R.sup.y).sub.2, wherein R.sup.y is as defined above. In certain embodiments, R.sup.1 and R.sup.2 are taken together to form a ring fragment selected from the group consisting of: CH.sub.2, CH.sub.2CH.sub.2, CH.sub.2CH.sub.2CH.sub.2, CH.sub.2OCH.sub.2, and CH.sub.2NR.sup.yCH.sub.2. In some embodiments, R.sup.1 and R.sup.2 are taken together to form an unsaturated linker moiety optionally containing one or more additional heteroatoms. In some embodiments, the resulting nitrogen-containing ring is partially unsaturated. In certain embodiments, the resulting nitrogen-containing ring comprises a fused polycyclic heterocycle.

(37) In certain embodiments, R.sup.3 is H. In certain embodiments, R.sup.3 is optionally C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic, 5- to 14-membered heteroaryl, phenyl, 8- to 10-membered aryl or 3- to 7-membered heterocyclic. In some embodiments, R.sup.3 is an optionally substituted radical selected from the group consisting of a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring. In certain embodiments, R.sup.3 is optionally substituted C.sub.1-12 aliphatic. In some embodiments, R.sup.3 is optionally substituted C.sub.1-6 aliphatic. In certain embodiments, R.sup.3 is optionally substituted phenyl.

(38) In certain embodiments, R.sup.3 is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, phenyl or benzyl. In some embodiments, R.sup.3 is butyl. In some embodiments, R.sup.3 is isopropyl. In some embodiments, R.sup.3 is perfluoro. In some embodiments, R.sup.3 is CF.sub.2CF.sub.3.

(39) In some embodiments, one or more R.sup.1 or R.sup.2 groups are taken together with R.sup.3 and intervening atoms to form an optionally substituted heterocyclic or heteroaryl ring. In certain embodiments, R.sup.1 and R.sup.3 are taken together to form an optionally substituted 5- or 6-membered ring. In some embodiments, R.sup.2 and R.sup.3 are taken together to form an optionally substituted 5- or 6-membered ring optionally containing one or more additional heteroatoms. In some embodiments, R.sup.1, R.sup.2 and R.sup.3 are taken together to form an optionally substituted fused ring system. In some embodiments, such rings formed by combinations of any of R.sup.1, R.sup.2 and R.sup.3 are partially unsaturated or aromatic.

(40) In certain embodiments, R.sup.4 is hydrogen. In some embodiments, R.sup.4 is an optionally substituted radical selected from the group consisting of C.sub.1-12 aliphatic, phenyl, 8- to 10-membered aryl, and 3- to 8-membered heterocyclic. In certain embodiments, R.sup.4 is a C.sub.1-12 aliphatic. In certain embodiments, R.sup.4 is a C.sub.1-6 aliphatic. In some embodiments, R.sup.4 is an optionally substituted 8- to 10-membered aryl group. In certain embodiments, R.sup.4 is optionally substituted C.sub.1-12 acyl or in some embodiments, optionally substituted C.sub.1-6 acyl. In certain embodiments, R.sup.4 is optionally substituted phenyl. In some embodiments, R.sup.4 is a hydroxyl protecting group. In some embodiments, R.sup.4 is a silyl protecting group. In some embodiments, R.sup.4 is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, allyl, phenyl or benzyl.

(41) In certain embodiments, R.sup.1 and R.sup.4 are taken together with intervening atoms to form one or more optionally substituted heterocyclic or heteroaryl rings optionally containing one or more additional heteroatoms.

(42) In some embodiments, an activating functional group is an N-linked amino group:

(43) ##STR00024##
wherein R.sup.1 and R.sup.2 are as defined above and described in classes and subclasses herein.

(44) In some embodiments, an N-linked amino activating functional group is selected from the group consisting of:

(45) ##STR00025## ##STR00026##

(46) In some embodiments, one or more activating functional groups is an N-linked hydroxyl amine derivative:

(47) ##STR00027##
wherein R.sup.1 and R.sup.4 are as defined above and described in classes and subclasses herein.

(48) In certain embodiments, one or more N-linked hydroxyl amine activating functional groups are selected from the group consisting of:

(49) ##STR00028##

(50) In some embodiments, an activating functional group in a provided metal complex is an amidine. In certain embodiments, such amidine activating functional groups are selected from:

(51) ##STR00029##
wherein each of R.sup.1, R.sup.2, and R.sup.3 is as defined above and described in classes and subclasses herein.

(52) In certain embodiments, an activating functional group is an N-linked amidine:

(53) ##STR00030##
wherein each of R.sup.1, R.sup.2, and R.sup.3 is as defined above and described in classes and subclasses herein. In certain embodiments, such N-linked amidine groups are selected from the group consisting of:

(54) ##STR00031##

(55) In certain embodiments, activating functional groups are amidine moieties linked through the imine nitrogen:

(56) ##STR00032##
wherein each of R.sup.1, R.sup.2, and R.sup.3 is as defined above and described in classes and subclasses herein. In certain embodiments, such imine-linked amidine activating functional groups are selected from the group consisting of:

(57) ##STR00033##

(58) In certain embodiments, activating functional groups are amidine moieties linked through a carbon atom:

(59) ##STR00034##
wherein each of R.sup.1, R.sup.2, and R.sup.3 is as defined above and described in classes and subclasses herein. In certain embodiments, such carbon-linked amidine activating groups are selected from the group consisting of:

(60) ##STR00035## ##STR00036##
In some embodiments, one or more activating functional groups is a carbamate. In certain embodiments, a carbamate is N-linked:

(61) ##STR00037##
wherein each of R.sup.1 and R.sup.2 is as defined above and described in classes and subclasses herein. In some embodiments, a carbamate is O-linked:

(62) ##STR00038##
wherein each of R.sup.1 and R.sup.2 is as defined above and described in classes and subclasses herein.

(63) In some embodiments, R.sup.2 is selected from the group consisting of: methyl, t-butyl, t-amyl, benzyl, adamantyl, allyl, 4-methoxycarbonylphenyl, 2-(methylsulfonyl)ethyl, 2-(4-biphenylyl)-prop-2-yl, 2-(trimethylsilyl)ethyl, 2-bromoethyl, and 9-fluorenylmethyl.

(64) In some embodiments, an activating functional group is a guanidine or bis-guanidine group:

(65) ##STR00039##
wherein each R.sup.1 and R.sup.2 is as defined above and described in classes and subclasses herein.

(66) In some embodiments, any two or more R.sup.1 or R.sup.2 groups are taken together with intervening atoms to form one or more optionally substituted carbocyclic, heterocyclic, aryl, or heteroaryl rings. In certain embodiments, R.sup.1 and R.sup.2 groups are taken together to form an optionally substituted 5- or 6-membered ring. In some embodiments, three or more R.sup.1 and/or R.sup.2 groups are taken together to form an optionally substituted fused ring system.

(67) In certain embodiments, where an activating functional group is a guanidine or bis guanidine moiety, it is selected from the group consisting of:

(68) ##STR00040## ##STR00041##

(69) In some embodiments, an activating functional group is a urea:

(70) ##STR00042##
wherein each R.sup.1 and R.sup.2 is independently as defined above and described in classes and subclasses herein.

(71) In certain embodiments, activating functional groups are oxime or hydrazone groups:

(72) ##STR00043##
wherein each of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 is as defined above and described in classes and subclasses herein.

(73) In some embodiments, an activating functional group is an N-oxide derivative:

(74) ##STR00044##
wherein each of R.sup.1 and R.sup.2 is as defined above and described in classes and subclasses herein.

(75) In certain embodiments, an N-oxide activating functional group is selected from the group consisting of:

(76) ##STR00045## ##STR00046##
II.b. Cationic Activating Groups

(77) In some embodiments, one or more tethered activating functional groups on provided metal complexes comprise a cationic moiety. In some embodiments, a cationic moiety is selected from a structure in Table Z-2:

(78) TABLE-US-00002 TABLE Z-2 0 - 0 0 or a combination of two or more of these,
wherein: each of R.sup.1, R.sup.2, and R.sup.3 is independently as defined above and described in classes and subclasses herein; R.sup.5 is R.sup.2 or hydroxyl; wherein R.sup.1 and R.sup.5 can be taken together with intervening atoms to form one or more optionally substituted carbocyclic, heterocyclic, aryl, or heteroaryl rings; each R.sup.6 and R.sup.7 is independently hydrogen or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, phenyl; or an 8- to 14-membered polycyclic aryl ring; wherein R.sup.6 and R.sup.7 can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more heteroatoms, and an R.sup.6 and R.sup.7 group can be taken with an R.sup.1 or R.sup.2 group to form one or more optionally substituted rings; each occurrence of R.sup.8 is independently selected from the group consisting of: halogen, NO.sub.2, CN, SR.sup.y, S(O)R.sup.y, S(O).sub.2R.sup.y, NR.sup.yC(O)R.sup.y, OC(O)R.sup.y, CO.sub.2R.sup.y, NCO, N.sub.3, OR.sup.7, OC(O)N(R.sup.y).sub.2, N(R.sup.y).sub.2, NR.sup.yC(O)R.sup.y, NR.sup.yC(O)OR.sup.y; or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, phenyl; or an 8- to 14-membered polycyclic aryl ring; wherein each R.sup.y is independently as defined above and described in classes and subclasses herein, and where two or more adjacent R.sup.8 groups can be taken together to form an optionally substituted saturated, partially unsaturated, or aromatic 5- to 12-membered ring containing 0 to 4 heteroatoms; X.sup. is any anion; Ring A is an optionally substituted, 5- to 10-membered heteroaryl group; and Ring B is an optionally substituted, 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 0-2 heteroatoms in addition to the depicted ring nitrogen atom independently selected from nitrogen, oxygen, or sulfur.

(79) In certain embodiments, a cationic activating functional group is a protonated amine:

(80) ##STR00078##
where each of R.sup.1 and R.sup.2 is as defined above and described in classes and subclasses herein.

(81) In some embodiments, a protonated amine activating functional group is selected from the group consisting of:

(82) ##STR00079## ##STR00080##

(83) In certain embodiments, an activating functional group is a guanidinium group:

(84) ##STR00081##
wherein each R.sup.1 and R.sup.2 is independently as defined above and described in classes and subclasses herein. In some embodiments, each R.sup.1 and R.sup.2 is independently hydrogen or C.sub.1-20 aliphatic. In some embodiments, each R.sup.1 and R.sup.2 is independently hydrogen or C.sub.1-12 aliphatic. In some embodiments, each R.sup.1 and R.sup.2 is independently hydrogen or C.sub.1-20 heteroaliphatic. In some embodiments, each R.sup.1 and R.sup.2 is independently hydrogen or phenyl. In some embodiments, each R.sup.1 and R.sup.2 is independently hydrogen or 8- to 10-membered aryl. In some embodiments, each R.sup.1 and R.sup.2 is independently hydrogen or 5- to 10-membered heteroaryl. In some embodiments, each R.sup.1 and R.sup.2 is independently hydrogen or 3- to 7-membered heterocyclic. In some embodiments, one or more of R.sup.1 and R.sup.2 is optionally substituted C.sub.1-12 aliphatic.

(85) In some embodiments, any two or more R.sup.1 or R.sup.2 groups are taken together with intervening atoms to form one or more optionally substituted carbocyclic, heterocyclic, aryl, or heteroaryl rings. In certain embodiments, R.sup.1 and R.sup.2 groups are taken together to form an optionally substituted 5- or 6-membered ring. In some embodiments, three or more R.sup.1 and/or R.sup.2 groups are taken together to form an optionally substituted fused ring system.

(86) In certain embodiments, a R.sup.1 and R.sup.2 group are taken together with intervening atoms to form a compound selected from:

(87) ##STR00082##
wherein each R.sup.1 and R.sup.2 is independently as defined above and described in classes and subclasses herein, and Ring G is an optionally substituted 5- to 7-membered saturated or partially unsaturated heterocyclic ring.

(88) It will be appreciated that when a guanidinium cation is depicted as

(89) ##STR00083##
all such resonance forms are contemplated and encompassed by the present disclosure. For example, such groups can also be depicted as

(90) ##STR00084##

(91) In some embodiments, a guanidinium activating functional group is selected from the group consisting of:

(92) ##STR00085##

(93) In some embodiments, an activating functional group is a sulfonium group or an arsonium group:

(94) ##STR00086##
wherein each of R.sup.1, R.sup.2, and R.sup.3 are as defined above and described in classes and subclasses herein.

(95) In some embodiments, an arsonium activating functional group is selected from the group consisting of:

(96) ##STR00087##

(97) In some embodiments, an activating functional group is an optionally substituted nitrogen-containing heterocycle. In certain embodiments, the nitrogen-containing heterocycle is an aromatic heterocycle. In certain embodiments, the optionally substituted nitrogen-containing heterocycle is selected from the group consisting of: pyridine, imidazole, pyrrolidine, pyrazole, quinoline, thiazole, dithiazole, oxazole, triazole, pyrazolem, isoxazole, isothiazole, tetrazole, pyrazine, thiazine, and triazine.

(98) In some embodiments, a nitrogen-containing heterocycle includes a quaternarized nitrogen atom. In certain embodiments, a nitrogen-containing heterocycle includes an iminium moiety such as

(99) ##STR00088##
In certain embodiments, the optionally substituted nitrogen-containing heterocycle is selected from the group consisting of pyridinium, imidazolium, pyrrolidinium, pyrazolium, quinolinium, thiazolium, dithiazolium, oxazolium, triazolium, isoxazolium, isothiazolium, tetrazolium, pyrazinium, thiazinium, and triazinium.

(100) In certain embodiments, a nitrogen-containing heterocycle is linked to a metal complex via a ring nitrogen atom. In some embodiments, a ring nitrogen to which the attachment is made is thereby quaternized, and in some embodiments, linkage to a metal complex takes the place of an NH bond and the nitrogen atom thereby remains neutral. In certain embodiments, an optionally substituted N-linked nitrogen-containing heterocycle is a pyridinium derivative. In certain embodiments, optionally substituted N-linked nitrogen-containing heterocycle is an imidazolium derivative. In certain embodiments, optionally substituted N-linked nitrogen-containing heterocycle is a thiazolium derivative. In certain embodiments, optionally substituted N-linked nitrogen-containing heterocycle is a pyridinium derivative.

(101) In some embodiments, an activating functional group is

(102) ##STR00089##
In certain embodiments, ring A is an optionally substituted, 5- to 10-membered heteroaryl group. In some embodiments, Ring A is an optionally substituted, 6-membered heteroaryl group. In some embodiments, Ring A is a ring of a fused heterocycle. In some embodiments, Ring A is an optionally substituted pyridyl group.

(103) In some embodiments, when Z is

(104) ##STR00090##
ring A is other than an imidazole, an oxazole, or a thiazole.

(105) In some embodiments, a nitrogen-containing heterocycle activating functional group is selected from the group consisting of:

(106) ##STR00091## ##STR00092##

(107) In certain embodiments, Ring B is a 5-membered saturated or partially unsaturated monocyclic heterocyclic ring. In certain embodiments, Ring B is a 6-membered saturated or partially unsaturated heterocycle. In certain embodiments, Ring B is a 7-membered saturated or partially unsaturated heterocycle. In certain embodiments, Ring B is tetrahydrofuranyl, tetrahydrothienyl, pyrrolidinyl, pyrrolidonyl, piperidinyl, pyrrolinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, decahydroquinolinyl, oxazolidinyl, piperazinyl, dioxanyl, dioxolanyl, diazepinyl, oxazepinyl, thiazepinyl, morpholinyl, and quinuclidinyl. In some embodiments, Ring B is piperidinyl.

(108) In some embodiments, an activating functional group is

(109) ##STR00093##
where each R.sup.1, R.sup.2, and R.sup.3 is independently as defined above and described in classes and subclasses herein.

(110) In some embodiments, an activating functional group is

(111) ##STR00094##
wherein each R.sup.1 and R.sup.2 is independently as defined above and described in classes and subclasses herein.

(112) In some embodiments, an activating functional group is

(113) ##STR00095##
wherein each R.sup.1, R.sup.2, and R.sup.3 is independently as defined above and described in classes and subclasses herein.

(114) In some embodiments, an activating functional group is

(115) ##STR00096##
wherein each of R.sup.1, R.sup.2, R.sup.6, and R.sup.7 is as defined above and described in classes and subclasses herein.

(116) In certain embodiments, R.sup.6 and R.sup.7 are each independently an optionally substituted group selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; phenyl, and 8-10-membered aryl. In some embodiments, R.sup.6 and R.sup.7 are each independently an optionally substituted C.sub.1-20 aliphatic. In some embodiments, R.sup.6 and R.sup.7 are each independently an optionally substituted C.sub.1-20 heteroaliphatic having. In some embodiments, R.sup.6 and R.sup.7 are each independently an optionally substituted phenyl or 8-10-membered aryl. In some embodiments, R.sup.6 and R.sup.7 are each independently an optionally substituted 5- to 10-membered heteroaryl. In some embodiments, R.sup.6 and R.sup.7 can be taken together with intervening atoms to form one or more rings selected from the group consisting of: optionally substituted C.sub.3-C.sub.14 carbocycle, optionally substituted C.sub.3-C.sub.14 heterocycle, optionally substituted C.sub.6-C.sub.10 aryl, and optionally substituted 5- to 10-membered heteroaryl. In some embodiments, R.sup.6 and R.sup.7 are each independently an optionally substituted C.sub.1-6 aliphatic. In some embodiments, each occurrence of R.sup.6 and R.sup.7 is independently methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, or benzyl. In some embodiments, each occurrence of R.sup.6 and R.sup.7 is independently perfluoro. In some embodiments, each occurrence of R.sup.6 and R.sup.7 is independently CF.sub.2CF.sub.3.

(117) In some embodiments, an activating functional group is

(118) ##STR00097##
wherein each R.sup.1 and R.sup.2 is independently as defined above and described in classes and subclasses herein.

(119) In some embodiments, an activating functional group is

(120) ##STR00098##
wherein each R.sup.1, R.sup.2, and R.sup.3 is independently as defined above and described in classes and subclasses herein.

(121) In some embodiments, an activating functional group is

(122) ##STR00099##
wherein each R.sup.1 and R.sup.2 is independently as defined above and described in classes and subclasses herein.

(123) In some embodiments, an activating functional group is

(124) ##STR00100##
wherein each R.sup.1 and R.sup.2 is independently as defined above and described in classes and subclasses herein.

(125) In some embodiments, an activating functional group is

(126) ##STR00101##
wherein each R.sup.1, R.sup.2, and R.sup.3 is independently as defined above and described in classes and subclasses herein.

(127) In some embodiments, an activating functional group is

(128) ##STR00102##
wherein each R.sup.1 and R.sup.2 is independently as defined above and described in classes and subclasses herein.
Counterions

(129) In certain embodiments, X is any anion. In certain embodiments, X is a nucleophile. In some embodiments, X is a nucleophile capable of ring opening an epoxide. In certain embodiments, X is absent. In certain embodiments, X is a nucleophilic ligand. Exemplary nucleophilic ligands include, but are not limited to, OR.sup.x, SR.sup.x, O(CO)R.sup.x, O(CO)OR.sup.x, O(CO)N(R.sup.x).sub.2, N(R.sup.x)CO)R.sup.x, NC, CN, halo (e.g., Br, I, Cl), N.sub.3, O(SO.sub.2)R.sup.x and OPR.sup.x.sub.3, wherein each R.sup.x is, independently, selected from hydrogen, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aryl and optionally substituted heteroaryl.

(130) In certain embodiments, X is O(CO)R.sup.x, wherein R.sup.x is selected from optionally substituted aliphatic, fluorinated aliphatic, optionally substituted heteroaliphatic, optionally substituted aryl, fluorinated aryl, and optionally substituted heteroaryl.

(131) For example, in certain embodiments, X is O(CO)R.sup.x, wherein R.sup.x is optionally substituted aliphatic. In certain embodiments, X is O(CO)R.sup.x, wherein R.sup.x is optionally substituted alkyl and fluoroalkyl. In certain embodiments, X is O(CO)CH.sub.3 or O(CO)CF.sub.3.

(132) Furthermore, in certain embodiments, X is O(CO)R.sup.x, wherein R.sup.x is optionally substituted aryl, fluoroaryl, or heteroaryl. In certain embodiments, X is O(CO)R.sup.x, wherein R.sup.x is optionally substituted aryl. In certain embodiments, X is O(CO)R.sup.x, wherein R.sup.x is optionally substituted phenyl. In certain embodiments, X is O(CO)C.sub.6H.sub.5 or O(CO)C.sub.6F.sub.5.

(133) In certain embodiments, X is OR.sup.x, wherein R.sup.x is selected from optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aryl, and optionally substituted heteroaryl.

(134) For example, in certain embodiments, X is OR.sup.x, wherein R.sup.x is optionally substituted aryl. In certain embodiments, X is OR.sup.x, wherein R.sup.x is optionally substituted phenyl. In certain embodiments, X is OC.sub.6H.sub.5 or OC.sub.6H.sub.2(2,4-NO.sub.2).

(135) In certain embodiments, X is halo. In certain embodiments, X is Br. In certain embodiments, X is Cl. In certain embodiments, X is I.

(136) In certain embodiments, X is O(SO.sub.2)R.sup.x. In certain embodiments X is OTs. In certain embodiments X is OSO.sub.2Me. In certain embodiments X is OSO.sub.2CF.sub.3. In some embodiments, X is a 2,4-dinitrophenolate anion.

(137) II.c. Phosphorous-Containing Activating Groups

(138) In some embodiments, activating functional groups Z are phosphorous containing groups.

(139) In certain embodiments, a phosphorous-containing functional group is chosen from the group consisting of: phosphines (PR.sup.y.sub.2); Phosphine oxides P(O)R.sup.y.sub.2; phosphinites P(OR.sup.4)R.sup.y.sub.2; phosphonites P(OR.sup.4).sub.2R.sup.y; phosphites P(OR.sup.4).sub.3; phosphinates OP(OR.sup.4)R.sup.y.sub.2; phosphonates; OP(OR.sup.4).sub.2R.sup.y; phosphates OP(OR.sup.4).sub.3; phosponium salts ([PR.sup.y.sub.3].sup.+) where a phosphorous-containing functional group may be linked to a metal complex through any available position (e.g. direct linkage via the phosphorous atom, or in some cases via an oxygen atom).

(140) In certain embodiments, a phosphorous-containing functional group is chosen from the group consisting of:

(141) ##STR00103##
or a combination of two or more of these wherein each R.sup.1, R.sup.2, and R.sup.4 is as defined above and described in classes and subclasses herein; and where two R.sup.4 groups can be taken together with intervening atoms to form an optionally substituted ring optionally containing one or more heteroatoms, or an R.sup.4 group can be taken with an R.sup.1 or R.sup.2 group to an optionally substituted carbocyclic, heterocyclic, heteroaryl, or aryl ring.

(142) In some embodiments, phosphorous containing functional groups include those disclosed in The Chemistry of Organophosphorus Compounds. Volume 4. Ter-and Quinquevalent Phosphorus Acids and their Derivatives. The Chemistry of Functional Group Series Edited by Frank R. Hartley (Cranfield University, Cranfield, U.K.). Wiley: New York. 1996. ISBN 0-471-95706-2, the entirety of which is hereby incorporated herein by reference.

(143) In certain embodiments, phosphorous containing functional groups have the formula:
(V).sub.b[(R.sup.9R.sup.10R.sup.11P).sup.+].sub.nW.sup.n-, wherein: V is O, N, or NR.sup.z, b is 1 or 0, each of R.sup.9, R.sup.10 and R.sup.11 are independently present or absent and, if present, are independently selected from the group consisting of optionally substituted C.sub.1-C.sub.20 aliphatic, optionally substituted phenyl, optionally substituted C.sub.8-C.sub.14 aryl, optionally substituted 3- to 14-membered heterocyclic, optionally substituted 5- to 14-membered heteroaryl, halogen, O, OR.sup.z, NR.sup.z, and N(R.sup.z).sub.2 where R.sup.z is hydrogen, or an optionally substituted C.sub.1-C.sub.20 aliphatic, optionally substituted phenyl, optionally substituted 8- to 14-membered aryl, optionally substituted 3- to 14-membered heterocyclic, or optionally substituted 5- to 14-membered heteroaryl, W is any anion, and n is an integer between 1 and 4.

(144) In some embodiments, an activating functional group is a phosphonate group:

(145) ##STR00104##
wherein each R.sup.1, R.sup.2, and R.sup.4 is independently as defined above and described in classes and subclasses herein.

(146) In specific embodiments, a phosphonate activating functional group is selected from the group consisting of:

(147) ##STR00105##

(148) In some embodiments, an activating functional group is a phosphonic diamide group:

(149) ##STR00106##
wherein each R.sup.1, R.sup.2, and R.sup.4 is independently as defined above and described in classes and subclasses herein. In certain embodiments, each R.sup.1 and R.sup.2 group in a phosphonic diamide is methyl.

(150) In some embodiments, an activating functional group is a phosphine group:

(151) ##STR00107##
wherein R.sup.1, and R.sup.2 are as defined above and described in classes and subclasses herein.

(152) In some embodiments, a phosphine activating functional group is selected from the group consisting of:

(153) ##STR00108##

(154) In some embodiments, the present invention provides bimetallic complexes and methods of using the same, wherein:

(155) i) an activating group is

(156) ##STR00109##

(157) ii) an activating group is

(158) ##STR00110##

(159) iii) an activating group is

(160) ##STR00111##

(161) iv) an activating group is

(162) ##STR00112##

(163) v) an activating group is

(164) ##STR00113##

(165) vi) an activating group is

(166) ##STR00114##

(167) vii) an activating group is

(168) ##STR00115##

(169) viii) an activating group is selected from the group consisting of

(170) ##STR00116##

(171) ix) an activating group is

(172) ##STR00117##

(173) x) an activating group is

(174) ##STR00118##

(175) xi) an activating group is

(176) ##STR00119##

(177) xii) an activating group is

(178) ##STR00120##

(179) xiii) an activating group is

(180) ##STR00121##

(181) xiv) an activating group is

(182) ##STR00122##

(183) xv) an activating group is

(184) ##STR00123##

(185) xvi) an activating group is

(186) ##STR00124##

(187) xvii) an activating group is

(188) ##STR00125##

(189) xviii) an activating group is

(190) ##STR00126##

(191) xix) an activating group is

(192) ##STR00127##

(193) xx) an activating group is

(194) ##STR00128##

(195) xxi) an activating group is

(196) ##STR00129##

(197) xxii) an activating group is

(198) ##STR00130##

(199) xxiii) an activating group is

(200) ##STR00131##

(201) xxiv) an activating group is

(202) ##STR00132##

(203) xxv) an activating group is

(204) ##STR00133##

(205) xxvi) an activating group

(206) ##STR00134##

(207) xxvii) an activating group is

(208) ##STR00135##

(209) xxviii) an activating group is

(210) ##STR00136##

(211) xxix) an activating group is

(212) ##STR00137##

(213) xxx) an activating group is

(214) ##STR00138##

(215) xxxi) an activating group is

(216) ##STR00139##

(217) xxxii) for subsets i) through xxxi), each R.sup.1 group is the same;

(218) xxxiii) for subsets i) through xxxi), each R.sup.1 group is hydrogen;

(219) xxxiv) for subsets i) through xxxi), at least one R.sup.1 group is different from other R.sup.1 groups;

(220) xxxv) for subsets i) through xxxi), R.sup.1 is optionally substituted C.sub.1-20 aliphatic;

(221) xxxvi) for subsets i) through xxxi), each R.sup.1 is independently hydrogen, CF.sub.2CF.sub.3, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, optionally substituted phenyl, or optionally substituted benzyl;

(222) xxxvii) for subsets i) through xxxvi), each R.sup.2 group is the same;

(223) xxxviii) for subsets i) through xxxvi), each R.sup.2 group is hydrogen;

(224) xxxix) for subsets i) through xxxvi), at least one R.sup.2 group is different from other R.sup.2 groups;

(225) xl) for subsets i) through xxxvi), R.sup.2 is optionally substituted C.sub.1-20 aliphatic;

(226) xli) for subsets i) through xxxvi), each R.sup.2 is independently hydrogen, CF.sub.2CF.sub.3, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, optionally substituted phenyl, or optionally substituted benzyl;

(227) xlii) for subsets i) through xli), R.sup.1 and R.sup.2 are the same;

(228) xliii) for subsets i) through xli) R.sup.1 and R.sup.2 are taken together with intervening atoms to form one or more optionally substituted carbocyclic, heterocyclic, aryl, or heteroaryl rings;

(229) xliv) for any of subsets i) through xliii) having R.sup.3, R.sup.3 is hydrogen;

(230) xlv) for any of subsets i) through xliii) having R.sup.3, R.sup.3 is optionally substituted C.sub.1-20 aliphatic;

(231) xlvi) for any of subsets i) through xliii) having R.sup.3, R.sup.3 is independently hydrogen, CF.sub.2CF.sub.3, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, optionally substituted phenyl, or optionally substituted benzyl;

(232) xlvii) for any of subsets i) through xliii) having R.sup.3, one or more R.sup.1 or R.sup.2 groups are taken together with R.sup.3 and intervening atoms to form an optionally substituted heterocyclic or heteroaryl ring;

(233) xlviii) for any of subsets i) through xlviii) having R.sup.4, R.sup.4 is hydrogen;

(234) xlix) for any of subsets i) through xlviii) having R.sup.4, R.sup.4 is optionally substituted C.sub.1-12 aliphatic;

(235) l) for any of subsets i) through xlviii) having R.sup.4, R.sup.1 and R.sup.4 are taken together with intervening atoms to form one or more optionally substituted heterocyclic or heteroaryl rings optionally containing one or more additional heteroatoms;

(236) li) for subsets xvi) and xvii), Ring A is a 5- to 6-membered heteroaryl group;

(237) lii) for subset li), R.sup.5 is hydroxyl;

(238) liii) for subset li), R.sup.5 is optionally substituted C.sub.1-20 aliphatic;

(239) liv) for subsets i) through xxxi) where an activating group is cationic, X is acetate;

(240) Iv) for subsets i) through xxxi) where an activating group is cationic, X is trifluoroacetate;

(241) lvi) for subsets i) through xxxi) where an activating group is cationic, X is optionally substituted benzoate;

(242) lvii) for subsets i) through xxxi) where an activating group is cationic, X is phenoxide;

(243) lviii) for subsets i) through xxxi) where an activating group is cationic, X is dinitrophenoxide;

(244) lvix) for subsets i) through xxxi) where an activating group is cationic, X is halo.

(245) It will be appreciated that for each of the classes and subclasses described above and herein, all possible combinations of the variables described in subsets i) through lvix) above are contemplated by the present invention. Thus, the invention encompasses any and all compounds of the formulae described above and herein, and subclasses thereof, generated by taking any possible combination of variables set forth herein (including, but not limited to subsets i) through lvix)).

(246) III. Metal Complexes

(247) In certain embodiments, the present invention provides metal complexes that include two metal atoms coordinated to a multidentate ligand system and at least one activating moiety tethered to a ligand.

(248) In some embodiments, provided metal complexes have a structure C-1:

(249) ##STR00140##
wherein: M.sup.1 is a first metal atom; M.sup.2 is a second metal atom;

(250) ##STR00141##
comprises a multidentate ligand system capable of coordinating both metal atoms; represents one or more activating moieties attached to the multidentate ligand system, where is a linker moiety covalently coupled to the ligand system, each Z is an activating functional group; and m is an integer from 1 to 4 representing the number of Z groups present on an individual linker moiety.

(251) In certain embodiments, provided metal complexes include two metal atoms coordinated to a multidentate ligand system and at least one activating moiety tethered to a multidentate ligand system. In some embodiments, there are 1 to 10 activating moieties tethered to a multidentate ligand. In certain embodiments, there are 1 to 8 such activating moieties tethered to a multidentate ligand. In certain embodiments, there are 1 to 4 such activating moieties tethered to the multidentate ligand.

(252) Syntheses of multidentate ligand systems are known in the art and include those described by Kember et al. Macromolecules 2010, 43, 2291-2298, and WO 2007/091616, the entire contents of each of which are hereby incorporated by reference. For example, in some embodiments a multidentate ligand is formed by reacting two equivalents of a dialdehyde (optionally comprising a activating moiety) with two equivalents of a diamine (optionally comprising a activating moiety). Such multidentate ligands may be combined (in some embodiments in situ) with two equivalents of a metal ion to form a bimetallic complex.

(253) Additional synthetic procedures for the synthesis of mono-metal complexes with tethered activating moieties are found in WO 2010/022388, the entire contents of which are hereby incorporated by reference.

(254) III.a. Metal Atoms

(255) In certain embodiments, M.sup.1 is a metal atom selected from periodic table groups 3-13, inclusive. In certain embodiments, M.sup.1 is a transition metal selected from periodic table groups 5-12, inclusive. In certain embodiments, M.sup.1 is a transition metal selected from periodic table groups 4-11, inclusive. In certain embodiments, M.sup.1 is a transition metal selected from periodic table groups 5-10, inclusive. In certain embodiments, M.sup.1 is a transition metal selected from periodic table groups 7-9, inclusive. In some embodiments, M.sup.1 is selected from the group consisting of Cr, Mn, V, Fe, Co, Mo, W, Ru, Al, and Ni. In some embodiments, M.sup.1 is a metal atom selected from the group consisting of: cobalt; chromium; aluminum; titanium; ruthenium, and manganese. In some embodiments, M.sup.1 is cobalt. In some embodiments, M.sup.1 is chromium. In some embodiments, M.sup.1 is aluminum. In some embodiments, M.sup.1 is zinc.

(256) In certain embodiments, M.sup.2 is a metal atom selected from periodic table groups 3-13, inclusive. In certain embodiments, M.sup.2 is a transition metal selected from periodic table groups 5-12, inclusive. In certain embodiments, M.sup.2 is a transition metal selected from periodic table groups 4-11, inclusive. In certain embodiments, M.sup.2 is a transition metal selected from periodic table groups 5-10, inclusive. In certain embodiments, M.sup.2 is a transition metal selected from periodic table groups 7-9, inclusive. In some embodiments, M.sup.2 is selected from the group consisting of Cr, Mn, V, Fe, Co, Mo, W, Ru, Al, and Ni. In some embodiments, M.sup.2 is a metal atom selected from the group consisting of: cobalt; chromium; aluminum; titanium; ruthenium, and manganese. In some embodiments, M.sup.2 is cobalt. In some embodiments, M.sup.2 is chromium. In some embodiments, M.sup.2 is aluminum. In some embodiments, M.sup.2 is zinc.

(257) In certain embodiments, M.sup.1 and M.sup.2 are the same metal. In other embodiments, M.sup.1 and M.sup.2 are different metals. In some embodiments, M.sup.1 and M.sup.2 are both cobalt. In some embodiments, M.sup.1 and M.sup.2 are both chromium. In some embodiments, M.sup.1 and M.sup.2 are both aluminum. In some embodiments, M.sup.1 and M.sup.2 are both zinc.

(258) In certain embodiments, a metal complex is dicobalt complex. In certain embodiments where the metal complex is a dicobalt complex, each cobalt atom has an oxidation state of 3+(i.e., Co(III)). In some embodiments, at least one cobalt metal has an oxidation state of 2+(i.e., Co(II)). In some embodiments, when the metal complex is a dicobalt complex, one cobalt atom has an oxidation state of 3+(i.e., Co(III)) and the other cobalt atom has an oxidation state of 2+(i.e., Co(II)).

(259) II.b. Ligands

(260) In some embodiments, a metal complex

(261) ##STR00142##
comprises two metal atoms coordinated to a single multidentate ligand system and in some embodiments, a metal complex comprises a chelate containing a plurality of individual ligands. In certain embodiments, a metal complex contains at least one bidentate ligand.

(262) In some embodiments, a metal complex contains at least one tridentate ligand. In some embodiments, a metal complex contains at least one tetradentate ligand. In some embodiments, a metal complex contains a hexadentate ligand.

(263) In certain embodiments, a multidentate ligand system in complexes of formula C1 has a structure

(264) ##STR00143##
where: Q.sup.1, Q.sup.2, Q.sup.3, Q.sup.3, Q.sup.4, Q.sup.5 and Q.sup.6 are each independently oxygen, nitrogen or sulfur atoms which may be optionally substituted if allowed by valency rules; each is optionally present and independently represents an optionally substituted bridge containing 2 to 20 carbon atoms, wherein such bridges can independently, or in combination, optionally form one or more optionally substituted rings, wherein each bridge present optionally contains one or more heteroatoms; and one or more groups is optionally substituted with one or more ; wherein each is independently an activating moiety as defined above and described in classes and subclasses herein.

(265) In certain embodiments, a multidentate ligand system in complexes of formula C1 has a structure

(266) ##STR00144##
where: Q.sup.1, Q.sup.2, Q.sup.3, Q.sup.4, Q.sup.5, Q.sup.6, and are independently as defined above and described in classes and subclasses herein; and each

(267) ##STR00145##
moiety is independently an optionally substituted carbon bridge that is optionally unsaturated, where any carbon atoms comprising the bridge may be part of one or more optionally substituted rings.

(268) In certain embodiments, a multidentate ligand system in complexes of formula C1 has a structure

(269) ##STR00146##
where: Q.sup.1, Q.sup.2, Q.sup.3, Q.sup.3, Q.sup.4, Q.sup.5, Q.sup.6 and are independently as defined above and described in classes and subclasses herein; rings C and D each independently represent an optionally substituted 5- to 12-membered mono- or polycyclic ring that may be saturated, partially unsaturated or aromatic and may optionally contain one or more heteroatoms; each R.sup.e is independently selected from the group consisting of hydrogen; a group; or an optionally substituted moiety selected from the group consisting of: C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring; wherein if two R.sup.e groups are present on the same position, they may be taken together to form a spirocyclic ring optionally containing one or more heteroatoms and optionally substituted with one or more R.sup.c groups (as defined below); and q is 1 or 2.

(270) In certain embodiments, a multidentate ligand system in complexes of formula C1 has a structure

(271) ##STR00147##
where: Q.sup.1, Q.sup.2, Q.sup.3, Q.sup.3, Q.sup.4, Q.sup.5, Q.sup.6, R.sup.e, and are independently as defined above and described in classes and subclasses herein; and each R.sup.a and R.sup.b is independently a substituent present on phenyl rings where two or more R.sup.a groups and/or two or more R.sup.b groups may be taken together to form one or more optionally substituted rings.

(272) In certain embodiments, R.sup.a and R.sup.b are independently selected from the group consisting of: a group, halogen, NO.sub.2, CN, SR.sup.y, S(O)R.sup.y, S(O).sub.2R.sup.y, NR.sup.yC(O)R.sup.y, OC(O)R.sup.y, CO.sub.2R.sup.y, NCO, N.sub.3, OR.sup.4, OC(O)N(R.sup.y).sub.2, N(R.sup.y).sub.2, NR.sup.yC(O)R.sup.y, NR.sup.yC(O)OR.sup.y; or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; phenyl; or an 8- to 14-membered polycyclic aryl ring; where two or more adjacent R.sup.a or R.sup.b groups can be taken together to form an optionally substituted saturated, partially unsaturated, or aromatic 5- to 12-membered ring containing 0 to 4 heteroatoms; wherein each R.sup.y and R.sup.4 is independently as defined above and described in classes and subclasses herein.

(273) In certain embodiments, a multidentate ligand system in complexes of formula C1 has a structure

(274) ##STR00148##
where: Q.sup.1, Q.sup.2, Q.sup.3, Q.sup.3, Q.sup.4, Q.sup.5, Q.sup.6, R.sup.a, R.sup.b and R.sup.c, are independently as defined above and described in classes and subclasses herein; and h and i are independently 1, 2, 3, or 4; and each R.sup.c and R.sup.d is independently selected from the group consisting of: a group, halogen, OR.sup.7, N(R.sup.y).sub.2, SR.sup.7, CN, NO.sub.2, SO.sub.2R.sup.y, SOR, SO.sub.2N(R.sup.y).sub.2; CNO, NR.sup.ySO.sub.2R.sup.y, NCO, N.sub.3, SiR.sub.3; or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, phenyl; or an 8- to 14-membered polycyclic aryl ring; where two or more R.sup.c or R.sup.d groups may be taken together with the carbon atoms to which they are attached and any intervening atoms to form one or more optionally substituted rings; and where when two R.sup.c or R.sup.d groups are attached to the same carbon atom, they may be taken together with the carbon atom to which they are attached to form a moiety selected from the group consisting of: a 3- to 8-membered spirocyclic ring, a carbonyl group, an optionally substituted alkene, an optionally substituted oxime, an optionally substituted hydrazone, and an optionally substituted imine.

(275) In certain embodiments, a multidentate ligand system in complexes of formula C1 has a structure

(276) ##STR00149##
where: Q.sup.1, Q.sup.2, Q.sup.3, Q.sup.3, Q.sup.4, Q.sup.5, Q.sup.6 R.sup.a, R.sup.b, R.sup.c, R.sup.d and R.sup.e are as defined above and described in classes and subclasses herein.

(277) In certain embodiments, a multidentate ligand system in complexes of formula C1 has a structure

(278) ##STR00150##
where: R.sup.a, R.sup.b, R.sup.c, R.sup.d and R.sup.e are independently as defined above and described in classes and subclasses herein; and R.sup.12 is optionally present, and if present is selected from the group consisting of: a group; or an optionally substituted radical selected from the group consisting of C.sub.1-20 aliphatic; C.sub.1-20 heteroaliphatic; and phenyl.

(279) In certain embodiments, at least one activating moiety is tethered to only one phenyl ring of a ligand, as shown in formula I:

(280) ##STR00151## where , M.sub.1, M.sup.2, R.sup.12, R.sup.a, R.sup.b, R.sup.c, R.sup.d, and R.sup.e are independently as defined above and described in classes and subclasses herein; X.sup.1 and X.sup.2 are each independently an anion or a nucleophile capable of ring opening an epoxide; and where one or more activating moieties present on the indicated phenyl ring in any one or more available positions as valency allows.

(281) It will be appreciated that, depending on the metal ion(s) selected and their oxidation state, additional counterion X groups and/or metals may be present. Alternatively or additionally, one or more X groups may interact with multiple metal centers. For example, the following formulae are contemplated by the present invention:

(282) ##STR00152##

(283) In certain embodiments, at least one activating moiety is tethered to two phenyl rings of a ligand, as shown in formula II:

(284) ##STR00153## where , M.sup.1, M.sup.2, R.sup.1, R.sup.a, R.sup.b, R.sup.c, R.sup.d, R.sup.e, X.sup.1, and X.sup.2 are independently as defined above and described in classes and subclasses herein; and where one or more activating moieties are present on each phenyl ring in any one or more available positions as valency allows.

(285) In certain embodiments of formulae described above, at least one phenyl ring of a ligand is independently selected from the group consisting of:

(286) ##STR00154## ##STR00155## ##STR00156##

(287) wherein each is independently an activating moiety bonded to any one or more unsubstituted positions of a phenyl ring.

(288) In certain embodiments, there is one group on each aryl ring in a position meta to the phenoxy group. In certain embodiments of complexes having formulae described above, at least one of the phenyl rings of a metal complex is independently selected from the group consisting of:

(289) ##STR00157## ##STR00158## ##STR00159##

(290) In certain embodiments both of the phenyl rings in ligands having the formula

(291) ##STR00160##
are substituted at one meta position as shown above. In certain embodiments, such ligands exist as a mixture of regioisiomers while in other embodiments, the ligands comprise substantially a single regioisomer.

(292) ##STR00161##

(293) In certain embodiments, there are two group on each aryl ring in a position meta to the phenoxy group. In certain embodiments of complexes having formulae described above, at least one of the phenyl rings of a metal complex is independently selected from the group consisting of:

(294) ##STR00162## ##STR00163## ##STR00164##

(295) In certain embodiments, there is one group on each aryl ring in a position para to the phenoxy group. In certain embodiments of complexes having formulae described above, at least one of the phenyl rings of a metal complex is independently selected from the group consisting of:

(296) ##STR00165##

(297) In certain embodiments, there is one group on a benzyl position of the phenyl ring. In certain embodiments of formulae described above, a metal complex comprises at least one moiety independently selected from the group consisting of:

(298) ##STR00166## ##STR00167## ##STR00168##

(299) As indicated above, two phenyl rings contained in a ligand structure need not be the same. Though not explicitly shown in certain formulae above, it is to be understood that a catalyst may have an activating moiety attached to different positions on each of the two rings, and such compounds are specifically encompassed within the scope of the present invention. Furthermore, activating moieties can be present on multiple parts of the ligand, for instance activating moieties can be present on the diamine bridge and on one or both phenyl rings in the same catalyst.

(300) In certain embodiments, at least one activating moiety is tethered to a diamine bridge of a ligand, as shown in formula III-a, III-b, and III-c:

(301) ##STR00169##

(302) wherein each of R.sup.a, R.sup.b, R.sup.c, R.sup.d, R.sup.e, Z, m, M.sup.1, M.sup.2, X.sup.1, X.sup.2, and R.sup.12 is independently as defined above and described in classes and subclasses herein.

(303) In certain embodiments, at least one activating moiety is tethered to a diamine bridge of a ligand, as shown in formula IV-a, IV-b, and IV-c:

(304) ##STR00170##

(305) wherein each of R.sup.a, R.sup.b, R.sup.c, R.sup.d, R.sup.e, Z, m, M.sup.1, M.sup.2, X.sup.1, X.sup.2, and R.sup.12 is independently as defined above and described in classes and subclasses herein.

(306) In certain embodiments, at least one activating moiety is tethered to a cyclic diamine bridge of a ligand, as shown in formula V-a, V-b, and V-c:

(307) ##STR00171##

(308) wherein each of R.sup.a, R.sup.b, R.sup.e, R.sup.d, R.sup.e, Z, m, M.sup.1, M.sup.2, X.sup.1, X.sup.2, and R.sup.12 is independently as defined above and described in classes and subclasses herein.

(309) In certain embodiments, at least one activating moiety is tethered to a cyclic diamine bridge of a ligand, as shown in formula VI-a, VI-b, and VI-c:

(310) ##STR00172##

(311) wherein each of R.sup.a, R.sup.b, R.sup.c, R.sup.d, R.sup.e, Z, m, M.sup.1, M.sup.2, X.sup.1, X.sup.2, and R.sup.12 is independently as defined above and described in classes and subclasses herein.

(312) In some embodiments, provided metal complexes are of formula VII-a through VII-e:

(313) ##STR00173##

(314) wherein each of X.sup.1 and X.sup.2, if present, is independently as defined above and described in classes and subclasses herein; and each of R.sup.c, R.sup.d, R.sup.e, Z, m, M.sup.1, and M.sup.2 is independently as defined above and described in classes and subclasses herein.

(315) In certain embodiments, metal complexes of the present invention include, but are not limited to those in Table 1 below:

(316) TABLE-US-00003 0 0 00 01 02 03 04 05 06 07 08 09 0 0 0 0 0 0 0 0 0 00 01 02 03 04 05 06 07 08 09 0

(317) wherein each M is independently as described above for M.sup.1 or M.sup.2.

(318) In certain embodiments, for complexes of Table 1, M.sup.1 and M.sup.2 is CoX, where X is as defined above and described in classes and subclasses herein. In certain embodiments, for complexes of Table 1, M.sup.1 and M.sup.2 is CoOC(O)CF.sub.3. In certain embodiments, for complexes of Table 1, M.sup.1 and M.sup.2 is CoOAc. In certain embodiments, for complexes of Table 1, M.sup.1 and M.sup.2 is CoOC(O)C.sub.6F.sub.5. In certain embodiments, for complexes of Table 1, M.sup.1 and M.sup.2 is CoN.sub.3. In certain embodiments, for complexes of Table 1, M.sup.1 and M.sup.2 is CoCl. In certain embodiments, for complexes of Table 1, M.sup.1 and M.sup.2 is Co-nitrophenoxy. In certain embodiments, for complexes of Table 1, M.sup.1 and M.sup.2 is Co-dinitrophenoxy. In some embodiments, for complexes of Table 1, M.sup.1 and M.sup.2 is CrX.

(319) IV. Polymers

(320) In some embodiments, the present disclosure provides methods of polymerization comprising contacting an epoxide with carbon dioxide in the presence of a provided metal complex to form a polycarbonate. In some embodiments, the present invention provides a method of polymerization, the method comprising: a) providing an epoxide of formula:

(321) ##STR00315## wherein: R.sup.a is hydrogen or an optionally substituted radical selected from the group consisting of C.sub.1-30 aliphatic; C.sub.1-30 heteroaliphatic; phenyl; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle, a 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; or an 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and each of R.sup.b, R.sup.c, and R.sup.d is independently hydrogen or an optionally substituted radical selected from the group consisting of C.sub.1-12 aliphatic; C.sub.1-12 heteroaliphatic; phenyl; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle, a 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur; a 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; or an 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur; wherein any of (R.sup.a and R.sup.c), (R.sup.c and R.sup.d), and (R.sup.a and R.sup.b) can be taken together with intervening atoms to form one or more optionally substituted rings; b) contacting the epoxide and carbon dioxide in the presence of a metal complex as described herein to provide a polymer having a formula selected from the group consisting of:

(322) ##STR00316##

(323) In some embodiments, a provided polymer has a formula:

(324) ##STR00317##
In some embodiments, a provided polymer has a formula:

(325) ##STR00318##
In some embodiments, carbon dioxide is optional and a provided polymer has a formula:

(326) ##STR00319##

(327) In certain embodiments, R.sup.b, R.sup.c, and R.sup.d are each hydrogen. In some embodiments, R.sup.a is optionally substituted C.sub.1-12 aliphatic. In some embodiments, R.sup.a is optionally substituted C.sub.1-12 heteroaliphatic. In some embodiments, the epoxide is ethylene oxide, propylene oxide, or cyclohexene oxide.

(328) In certain embodiments, one of R.sup.a, R.sup.b, R.sup.c, and R.sup.d is hydrogen. In certain embodiments, two of R.sup.e, R.sup.b, R.sup.c, and R.sup.d are hydrogen. In certain embodiments, three of R.sup.a, R.sup.b, R.sup.c, and R.sup.d are hydrogen.

(329) In certain embodiments, R.sup.a is hydrogen. In certain embodiments, R.sup.b is hydrogen. In certain embodiments, R.sup.a is hydrogen. In certain embodiments, R.sup.d is hydrogen.

(330) In certain embodiments, R.sup.a, R.sup.b, R.sup.c, and R.sup.d are each independently an optionally substituted C.sub.1-30 aliphatic group. In certain embodiments, R.sup.a, R.sup.b, R.sup.c, and R.sup.d are each independently an optionally substituted C.sub.1-20 aliphatic group. In certain embodiments, R.sup.a, R.sup.b, R.sup.c, and R.sup.d are each independently an optionally substituted C.sub.1-12 aliphatic group. In certain embodiments, R.sup.a, R.sup.b, R.sup.c, and R.sup.d are each independently an optionally substituted C.sub.1-8 aliphatic group. In certain embodiments, R.sup.a, R.sup.b, R.sup.c, and R.sup.d are each independently an optionally substituted C.sub.3-8 aliphatic group. In certain embodiments, R.sup.a, R.sup.b, R.sup.c, and R.sup.d are each independently an optionally substituted C.sub.3-12 aliphatic group.

(331) In certain embodiments, R.sup.a is an optionally substituted C.sub.1-30 aliphatic group. In certain embodiments, R.sup.b is an optionally substituted C.sub.1-30 aliphatic group. In certain embodiments, R.sup.c is an optionally substituted C.sub.1-30 aliphatic group. In certain embodiments, R.sup.d is an optionally substituted C.sub.1-30 aliphatic group.

(332) In some embodiments, an R.sup.a and an R.sup.b attached to the same carbon are taken together to form one or more optionally substituted 3-12-membered carbocyclic rings. In some embodiments, an R.sup.a and an R.sup.b attached to the same carbon are taken together to form a polycyclic carbocycle comprising two or more optionally substituted 3-8-membered carbocyclic rings. In some embodiments, an R.sup.a and an R.sup.b attached to the same carbon are taken together to form a polycyclic carbocycle comprising two or more optionally substituted 5-7-membered carbocyclic rings.

(333) In some embodiments, an R.sup.a and an R.sup.b attached to the same carbon are taken together to form a bicyclic carbocycle comprising two optionally substituted 3-12-membered carbocyclic rings. In some embodiments, an R.sup.a and an R.sup.b attached to the same carbon are taken together to form a bicyclic carbocycle comprising two optionally substituted 3-8-membered carbocyclic rings. In some embodiments, an R.sup.a and an R.sup.b attached to the same carbon are taken together to form a bicyclic carbocycle comprising two optionally substituted 5-7-membered carbocyclic rings.

(334) In certain embodiments, an R.sup.a and an R.sup.b attached to the same carbon are taken together to form an optionally substituted 3-12-membered carbocyclic ring. In certain embodiments, an R.sup.a and an R.sup.b attached to the same carbon are taken together to form an optionally substituted 3-8-membered carbocyclic ring. In certain embodiments, an R.sup.a and an R.sup.b attached to the same carbon are taken together to form an optionally substituted 5-7-membered carbocyclic ring.

(335) In some embodiments, an R.sup.b and an R.sup.c attached to adjacent carbons are taken together to form one or more optionally substituted 3-12-membered carbocyclic rings. In some embodiments, an R.sup.b and an R.sup.c attached to adjacent carbons are taken together to form a polycyclic carbocycle comprising two or more optionally substituted 3-8-membered carbocyclic rings. In some embodiments, an R.sup.b and an R.sup.c attached to adjacent carbons are taken together to form a polycyclic carbocycle comprising two or more optionally substituted 5-7-membered carbocyclic rings.

(336) In some embodiments, an R.sup.b and an R.sup.c attached to adjacent carbons are taken together to form a bicyclic carbocycle comprising two optionally substituted 3-12-membered carbocyclic rings. In some embodiments, an R.sup.b and an R.sup.c attached to adjacent carbons are taken together to form a bicyclic carbocycle comprising two optionally substituted 3-8-membered carbocyclic rings. In some embodiments, an R.sup.b and an R.sup.c attached to adjacent carbons are taken together to form a bicyclic carbocycle comprising two optionally substituted 5-7-membered carbocyclic rings.

(337) In certain embodiments, an R.sup.b and an R.sup.c attached to adjacent carbons are taken together to form an optionally substituted 3-12-membered carbocyclic ring. In certain embodiments, an R.sup.b and an R.sup.c attached to adjacent carbons are taken together to form an optionally substituted 3-8-membered carbocyclic ring. In certain embodiments, an R.sup.b and an R.sup.c attached to adjacent carbons are taken together to form an optionally substituted 5-7-membered carbocyclic ring.

(338) In certain embodiments, the polymer comprises a copolymer of two different repeating units where R.sup.a, R.sup.b, and R.sup.c of the two different repeating units are not all the same. In some embodiments, a polymer comprises a copolymer of three or more different repeating units wherein R.sup.a, R.sup.b, and R.sup.c of each of the different repeating units are not all the same as R.sup.a, R.sup.b, and R.sup.c of any of the other different repeating units. In some embodiments, a polymer is a random copolymer. In some embodiments, a polymer is a tapered copolymer.

(339) In some embodiments, a polymer contains a metal complex as described herein. In some embodiments, a polymer comprises residue of a metal complex as described herein. In some embodiments, a polymer comprises a salt of an organic cation and X, wherein X is a nucleophile or counterion. In some embodiments, X is 2,4-dinitrophenolate anion.

(340) In some embodiments, R.sup.a is optionally substituted C.sub.1-12 aliphatic. In some embodiments, R.sup.a is optionally substituted C.sub.1-12 heteroaliphatic. In some embodiments, R.sup.a is optionally substituted phenyl. In some embodiments, R.sup.a is optionally substituted 8- to 10-membered aryl. In some embodiments, R.sup.a is optionally substituted 5- to 10-membered heteroaryl. In some embodiments, R.sup.a is optionally substituted 3- to 7-membered heterocyclic.

(341) In certain embodiments, R.sup.a is selected from methyl, ethyl, propyl, butyl, vinyl, allyl, phenyl, trifluoromethyl,

(342) ##STR00320##
or any two or more of the above. In certain embodiments, R.sup.a is methyl. In certain embodiments, R.sup.a is ethyl. In certain embodiments, R.sup.a is propyl. In certain embodiments, R.sup.a is butyl. In certain embodiments, R.sup.a is vinyl. In certain embodiments, R.sup.a is allyl. In certain embodiments, R.sup.a is phenyl. In certain embodiments, R.sup.a is trifluoromethyl. In certain embodiments, R.sup.a is

(343) ##STR00321##
In certain embodiments, R.sup.a is

(344) ##STR00322##
In certain embodiments, R.sup.a is

(345) ##STR00323##
In certain embodiments, R.sup.a is

(346) ##STR00324##
In certain embodiments, R.sup.a is

(347) ##STR00325##
In certain embodiments, R.sup.a is

(348) ##STR00326##
In certain embodiments, R.sup.a is

(349) ##STR00327##

(350) In some embodiments, R.sup.b is hydrogen. In some embodiments, R.sup.b is optionally substituted C.sub.1-12 aliphatic. In some embodiments, R.sup.b is optionally substituted C.sub.1-12 heteroaliphatic. In some embodiments, R.sup.b is optionally substituted phenyl. In some embodiments, R.sup.b is optionally substituted 8- to 10-membered aryl. In some embodiments, R.sup.b is optionally substituted 5- to 10-membered heteroaryl. In some embodiments, R.sup.b is optionally substituted 3- to 7-membered heterocyclic.

(351) In some embodiments, R.sup.c is hydrogen. In some embodiments, R.sup.c is optionally substituted C.sub.1-12 aliphatic. In some embodiments, R.sup.c is optionally substituted C.sub.1-12 heteroaliphatic. In some embodiments, R.sup.c is optionally substituted phenyl. In some embodiments, R.sup.c is optionally substituted 8- to 10-membered aryl. In some embodiments, R.sup.c is optionally substituted 5- to 10-membered heteroaryl. In some embodiments, R.sup.c is optionally substituted 3- to 7-membered heterocyclic.

(352) In some embodiments, R.sup.a and R.sup.c are taken together with intervening atoms to form one or more rings selected from the group consisting of: optionally substituted C.sub.3-C.sub.14 carbocycle, optionally substituted 3- to 14-membered heterocycle, optionally substituted phenyl, optionally substituted C.sub.8-C.sub.10 aryl, and optionally substituted 5- to 10-membered heteroaryl.

(353) In some embodiments, R.sup.b and R.sup.c are taken together with intervening atoms to form one or more rings selected from the group consisting of: optionally substituted C.sub.3-C.sub.14 carbocycle, optionally substituted 3- to 14-membered heterocycle, optionally substituted phenyl, optionally substituted C.sub.8-C.sub.10 aryl, and optionally substituted 5- to 10-membered heteroaryl.

(354) In some embodiments, R.sup.a and R.sup.b are taken together with intervening atoms to form one or more rings selected from the group consisting of: optionally substituted C.sub.3-C.sub.14 carbocycle, optionally substituted 3- to 14-membered heterocycle, optionally substituted phenyl, optionally substituted C.sub.8-C.sub.10 aryl, and optionally substituted 5- to 10-membered heteroaryl.

(355) In some embodiments, the invention includes methods for synthesizing polyethers from epoxides. Suitable methods of performing these reactions are disclosed in U.S. Pat. No. 7,399,822, the entire contents of which are hereby incorporated herein by reference.

(356) In some embodiments, the invention includes methods for synthesizing cyclic carbonates from carbon dioxide and epoxides using catalysts described above, suitable methods of performing this reaction are disclosed in U.S. Pat. No. 6,870,004, which is incorporated herein by reference.

(357) While we have described a number of embodiments of this invention, it is apparent that our basic examples may be altered to provide other embodiments that utilize the compounds and methods of this invention. Therefore, it will be appreciated that the scope of this invention is to be defined by the appended claims rather than by the specific embodiments that have been presented by way of example.