Transition metal complex for use in or as a catalyst for olefin polymerization

Abstract

A catalyst for olefin polymerization containing at least one metal complex comprising at least one —SF.sub.5 group attached to a ligand bound to the metal. The invention further relates to catalyst, a process for making polyolefins and dispersions of UHMWPE.

Claims

1. Transition metal complex suitable for use in a catalyst for olefin polymerization wherein the metal complex comprises at least one —SF.sub.5 group attached to a ligand bound to the metal, wherein the metal is Ti, Zr, or Hf.

2. The transition metal complex according to claim 1, having one of the structures according to: ##STR00038##

3. A catalyst for polymerization of olefins, the catalyst comprising a transition metal complex according to claim 1 and optionally a cocatalyst.

4. A process for the (co)polymerization of olefinic monomers, the process comprising polymerizing one or more olefinic monomers in the presence of a catalyst comprising a transition metal complex according to claim 1 and optionally a cocatalyst, wherein an activator is present and the molar ratio of the activator to the catalyst is in the range from 0.1 to 10.

5. Transition metal complex suitable for use in a catalyst for olefin polymerization wherein the metal complex comprises at least one —SF.sub.5 group attached to a ligand bound to the metal, and wherein the complex is a catalyst or compound having the general structure 12. ##STR00039## where the substituents and indices have the following meanings: M is a transition metal from groups 3 to 10 of the periodic table of the elements, L.sub.1 denotes a neutral Lewis base, L.sub.2 denotes halide ions, amide ions (R.sup.16).sub.hNH.sub.2-h, h denoting an integer from 0 to 2, C.sub.1-C.sub.6 alkyl anions, allyl anions, benzyl anions or aryl anions, wherein optionally L.sub.1 and L.sub.2 are linked by one or more covalent bonds; X is CR or nitrogen atom (N), wherein R is hydrogen, a C.sub.1-C.sub.6 alkyl group, a C.sub.7-C.sub.13 aralkyl radical or a C.sub.6-C14 aryl group, unsubstituted or substituted by one or more C.sub.1-C.sub.12 alkyl groups, halogens, mono- or polyhalogenated C.sub.1-C.sub.12 alkyl groups, C.sub.1-C.sub.12 alkoxy groups, silyloxy groups OSiR.sup.11R.sup.12R.sub.13; amino groups NR.sup.14R.sup.15 or C.sub.1-C.sub.12 thioether groups; Y is OH group, oxygen, sulfur, N-R.sup.10 or P-R.sup.10, provided that when Y is OH group, the bond between Y and M is a coordinate bond; a is 1 or 2; b=0 or 1; c=0 or 1, and wherein a+b+c equals the valency of the transition metal M and wherein b+c is 1 or 2; R.sup.1 to R.sup.9 are independently of one another: hydrogen; C.sub.1-C.sub.12 alkyl, the alkyl groups being branched or unbranched, optionally C.sub.1-C.sub.12 alkyl being substituted one or more times by identical or different substituents selected from C.sub.1-C.sub.12 alkyl groups, halogens, C.sub.1-C.sub.12 alkoxy groups, C.sub.1-C.sub.12 thioether groups; and C.sub.7-C.sub.13 aralkyl; C.sub.3-C.sub.12 cycloalkyl; C.sub.3-C.sub.12 cycloalkyl substituted one or more times by identical or different substituents selected from C.sub.1-C.sub.12 alkyl groups, halogens, C.sub.1-C.sub.12 alkoxy groups and C.sub.1-C.sub.12 thioether groups; C.sub.6-C.sub.14 aryl, optionally substituted by identical or different substituents selected from one or more C.sub.1-C.sub.12 alkyl groups, halogens, mono- or polyhalogenated C.sub.1-C.sub.12 alkyl groups, C.sub.1-C.sub.12 alkoxy groups, silyloxy groups OSiR.sup.11R.sup.12R.sup.13; amino groups NR.sup.14R.sup.15 and C.sub.1-C.sub.12 thioether groups; C.sub.1-C.sub.12 alkoxy groups; silyloxy groups OSiR.sup.11R.sup.12R.sup.13; halogens; NO.sub.2 groups or amino groups NR.sup.14R.sup.15; or —SF.sub.5 groups or radicals of the formula 14 below, where n is an integer from 1 to 5; optionally in each case two adjacent radicals R.sup.1 to R.sup.9 forming with one another a saturated or unsaturated 5- to 8-membered ring; R.sup.10 to R.sup.16 independently of one another being hydrogen, C.sub.1-C.sub.20 alkyl groups, which are optionally substituted with O(C.sub.1-C.sub.6 alkyl) or N(C.sub.1-C.sub.6 alkyl).sub.2 groups, C.sub.3-C.sub.12 cycloalkyl groups, C.sub.7-C.sub.13 aralkyl radicals, C.sub.7-C.sub.13 substituted aralkyl radicals, C.sub.6-C.sub.14 aryl groups or substituted C.sub.6-C.sub.14 aryl groups; wherein at least one of the radicals R.sup.1 to R.sup.9 is in the form of a —SF.sub.5 group or a radical of the formula 14 below ##STR00040## where n is an integer from 1 to 5.

6. A catalyst for olefin polymerization, the catalyst comprising at least one transition metal complex according to claim 5.

7. The transition metal complex according to claim 5, wherein the metal M is a transition metal from groups 3-6 of the period table, a is 2, indicating that the transition metal comprises 2 ligands.

8. The transition metal complex according to claim 5, wherein the complex has a structure according to formula 13, ##STR00041## and wherein R.sup.1-R.sup.9, L.sub.1, L.sub.2, M, X, and Y have the meanings as defined in claim 5.

9. The transition metal complex according to claim 5, wherein Y is an —OH group or oxygen.

10. The transition metal complex according to claim 8, wherein the complex has a structure represented by formula 15 ##STR00042## wherein R.sup.5, R.sup.7, and R.sup.9 are independently H, methyl, isopropyl, NO.sub.2 or ##STR00043## wherein R.sup.1 and R.sup.3 are independently H, methyl, isopropyl, NO.sub.2, I, or ##STR00044## where n is an integer from 1 to 5; with the proviso that at least one of R.sup.1, R.sup.3, R.sup.5, R.sup.7 and R.sup.9 is a ##STR00045## wherein n is an integer from 1 to 5.

11. The transition metal complex according to claim 5, wherein the —SF.sub.5 containing group is a 3,5-dipentafluorosulfanyl phenyl group.

12. The transition metal complex according to claim 8, wherein the complex has a structure represented by any one of formula 13.sub.1-13.sub.5, ##STR00046## wherein in formula 13.sub.3 and 13.sub.4, R.sup.5 and R.sup.9 are independently H, —CH.sub.3 or iso-propyl, and ##STR00047## wherein in formula 13.sub.1 and formula 13.sub.5, R.sup.1 and R.sup.3 are independently H, CH.sub.3, isopropyl, phenyl, naphthyl, anthracenyl, —NO.sub.2, or ##STR00048## wherein in formula 13.sub.1-13.sub.5, L.sub.1 is pyridine or 3,3′,3″-phosphanetriyl tris(benzenesulfonic acid) trisodium salt and L.sub.2 is a methyl group.

13. The transition metal complex according to claim 5, wherein L.sub.1 is pyridine or 3,3′,3″-phosphanetriyl tris(benzenesulfonic acid) trisodium salt, L.sub.2 is a methyl group, R.sup.1 and R.sup.3 are independently H, CH.sub.3, isopropyl, phenyl, naphthyl, anthracenyl, NO.sub.2, or ##STR00049##

14. The transition metal complex according to claim 5, wherein L.sub.1 denotes phosphanes (R.sup.19).sub.xPH.sub.3-x or amines (R.sup.16).sub.xNH.sub.3-x with identical or different radicals R.sup.16, ethers (R.sup.16).sub.2O, H.sub.2O, alcohols (R.sup.16)OH, pyridine, pyridine derivatives of the formula C.sub.5H.sub.5-x (R.sup.16).sub.xN, CO, C.sub.1-C.sub.12 alkylnitriles, C.sub.6-C.sub.14 arylnitriles or ethylenically unsaturated double bond systems, and wherein x denotes an integer from 0 to 3, wherein R.sup.16 has the same meaning as defined in claim 3, and R.sup.19 is a C.sub.1-C.sub.20 alkyl group, C.sub.3-C.sub.12 cycloalkyl group, C.sub.7-C.sub.13 aralkyl radical, C.sub.6-C.sub.14 aryl group, which alkyl, cycloalkyl, aralkyl and aryl groups are optionally substituted in turn by O(C.sub.1-C.sub.6 alkyl) or N(C.sub.1-C.sub.6 alkyl).sub.2 groups, sulfonated groups or the salts of sulfonated groups.

15. The transition metal complex according to claim 14, wherein L.sub.1 denotes phosphanes of the formula (R.sup.19).sub.xPH.sub.3-x, and the phosphanes are selected from the salts of mono, di and tri sulphonated triphenylphosphanes.

16. The transition metal complex according to claim 15, wherein the phosphanes of the formula (R.sup.19).sub.xPH.sub.3-x are the sodium salts of mono, di or tri sulphonated triphenylphosphanes.

Description

EXAMPLES

(1) Determination of Molecular Weight

(2) Molecular weights (weight-average molecular weight (Mw) and number-average molecular weight (Mn)) of obtained polyethylenes were determined by HT-GPC in 1,2,4-trichlorobenzene at 160° C. at a flow rate of 1 mL min-1 on a Polymer Laboratories 220 instrument equipped with Olexis columns with differential refractive index, viscosity, and light scattering detectors. Determination of Mw and Mn was performed in accordance with the method of ASTM D647412.

(3) Polymerization in Toluene

(4) Ethylene polymerizations in toluene were carried out in a 300 mL stainless steel mechanically stirred pressure reactor equipped with a heating/cooling jacket supplied by a thermostat controlled by a thermocouple dipping into the polymerization mixture. This reactor was placed under vacuum and backfilled with argon, this process was repeated three times at temperatures above 60° C. to ensure the reactor was thoroughly degassed before cooling to 5° C. below the desired temperature. 100 mL of distilled and degassed toluene was then cannula-transferred to the cooled reactor and stirred at 500 rpm. 5 μmol of the appropriate precatalyst was then dissolved in minimal toluene and transferred to the reactor via syringe. The stirring speed was increased to 1000 rpm and the reactor was pressurized to a constant pressure of 40 bar of ethylene, while the temperature was increased to the desired value. Ethylene flow to the reactor was stopped after 40 minutes and the reactor was carefully vented. Bulk polymer was precipitated in methanol, filtered, washed thoroughly with methanol and dried in vacuum oven (50° C., 30 mBar) overnight.

(5) Polymerization in Aqueous Dispersion

(6) Ethylene polymerizations in aqueous media were carried out in a 300 mL stainless steel mechanically stirred pressure reactor equipped with a heating/cooling jacket supplied by a thermostat controlled by a thermocouple dipping into the polymerization mixture. This reactor was placed under vacuum and backfilled with argon, this process was repeated three times at temperatures above 60° C. to ensure the reactor was thoroughly degassed before cooling to 10° C. In a 250 mL Schienk-type glass vessel, SOS (sodiumdodecylsulfate) (1.5 or 3 g) and CsOH (512 mg, if required) were dissolved in 100 mL distilled and degassed water, 90 mL of the resulting homogenous solution was then cannula-transferred to the cooled reactor and stirred at 500 rpm. 5 μmol of the appropriate precatalyst was then dissolved in the remaining 10 mL of aqueous solution and transferred to the reactor via syringe. The stirring speed was increased to 1000 rpm and the reactor was pressurized to a constant pressure of 40 bar of ethylene, while the temperature was increased to the desired value. Ethylene flow to the reactor was stopped after the appropriate time (30 or 60 minutes) and the reactor was carefully vented. The resulting dispersion was filtered over cotton wool, and the solids content was determined by precipitation of a 20 g aliquot with 150 mL methanol. The obtained bulk polymer was then filtered, washed thoroughly (with water and methanol) and dried in a vacuum oven (50° C., 30 mBar) overnight.

(7) Examples with group 7-10 Transition Metals.

(8) Synthesis of —SF.sub.5Substituted Compounds

(9) Synthesis of the desired —SF.sub.5-substituted ligands was simple and required only a few steps. The commercially available 1-bromo-3,5-bis(pentafluorosulfanyl)benzene is easily converted to the pinacol-protected boronic acid ester (3) using Pd(dppf)Cl.sub.2. GC showed conversion of the starting material to the product was >95% after 4.5 hours and the pure product could be isolated in a 76% yield.

(10) ##STR00028##

(11) From the boronic acid ester, the desired anilines (4, 6) were synthesized by Suzuki coupling either with 2,6-dibromo- or 2,4,6-tribromoaniline. Salicylaldimines (5, 7) were then synthesized by acid catalysed condensation of these anilines with the appropriate salicylaldehyde. Precatalysts (1-SF.sub.5/Py, 2-SF.sub.5/Py) were obtained in near quantitative yields by reaction with (TMEDA)NiMe2 in the presence of pyridine (Scheme 1).

(12) Synthesis of a water soluble complex is performed by introducing TPPTS (3,3′,3″-Phosphanetriyltris (benzenesulfonic acid) trisodium salt) as a ligand to an intermediate complex, stabilised by the labile neutral ligand DMF. Complete exchange of DMF for TPPTS was unsuccessful but by washing away the lipophilic intermediate catalyst a crude pre-catalyst mixture of the water soluble complex 1-SF.sub.5/TPPTS, free TPPTS, and residual DMF was isolated. From the 1H NMR relative ratios of these compounds can be determined, allowing for an approximate molecular weight to be calculated. This crude mixture could then be used to give stable dispersions of polyethylene through direct polymerisation.

(13) ##STR00029##

(14) ##STR00030## ##STR00031##

(15) Further two catalysts (1-SF.sub.5/TPPTS and 2-SF.sub.5/TPPTS) have been prepared according to the following structures:

(16) ##STR00032##
TPPTS is 3,3′,3″-Phosphanetriyltris(benzenesulfonic acid) trisodium salt

COMPARATIVE EXAMPLES

(17) Nickel catalyst were prepared using CF.sub.3 substituents (as comparative examples), and the catalytic performance was compared to the catalysts bearing the inventive —SF.sub.5 substituents.

Comparative Examples (CF.SUB.3 .Substituents)

(18) ##STR00033##
Polymerizations

(19) Initial polymerisations were carried out in toluene over a wide temperature range (30-70° C.) to assess the effect of the substituent on both catalyst performance and polymer properties. In toluene —SF.sub.5-substituted complexes show reduced productivity when compared to analogous CF.sub.3-complexes, (shown in FIG. 2) particularly in the case of 2-SF.sub.5/Py at 30° C. (Table 1, Entry 7).

(20) TABLE-US-00001 TABLE 1 Ethylene Polymerisation Results with Complexes 1-SF.sub.5/Py, 2-SF.sub.5/Py and CF.sub.3-Analogs (1-CF.sub.3/Py, 2-CF.sub.3/Py) as Precatalysts in Toluene..sup.a M.sub.n T Yield [10.sup.3 T.sub.m Crystallinity Branches/ Entry Precatalyst [° C.] [g] TOF.sup.b g/mol].sup.c M.sub.w/M.sub.n.sup.c [° C.].sup.d [%].sup.d 1000 C..sup.e 1 1-SF.sub.5/Py 30 1.88 2.02 302.8 1.6 134 55 1.0 2 1-SF.sub.5/Py 50 4.85 5.20 115.1 2.5 128 56 2.5 3 1-SF.sub.5/Py 70 7.38 7.91 24.1 2.3 122 54 7.2 4 1-CF.sub.3/Py 30 3.41 3.66 174.6 1.8 131 53 2.9 5 1-CF.sub.3/Py 50 5.47 5.86 26.5 2.3 121 59 8.1 6 1-CF.sub.3/Py 70 10.7 11.41 10.0 2.0 115 61 11.7 7 2-SF.sub.5/Py 30 0.40 0.42 263.3 2.0 132 58 1.0 8 2-SF.sub.5/Py 50 3.29 3.53 122.3 3.3 128 56 3.0 9 2-SF.sub.5/Py 70 9.48 10.15 25.1 2.3 121 56 8.0 10 2-CF.sub.3/Py 30 4.06 4.35 466.1 1.6 132 55 1.7 11 2-CF.sub.3/Py 50 6.91 7.40 31.5 2.5 118 55 10.6 12 2-CF.sub.3/Py 70 19.03 20.39 11.6 2.2 113 52 15.2.sup.f .sup.aPolymerisation Conditions: 5 μmol of precatalyst, 100 mL of toluene, 40 bar of C.sub.2H.sub.4, 40 min. .sup.b10.sup.4 × mol [C.sub.2H.sub.4] × mol.sup.−1 [Ni] × h.sup.−1. .sup.cDetermined by GPC at 160° C. .sup.dDetermined by DSC. .sup.eDetermined by .sup.13C NMR spectroscopy. .sup.fIncludes 1.1 ethyl branches and <0.5 n-propyl branches.

(21) While the loss of activity may seem like a drawback to using —SF.sub.5-complexes, it is relatively small and in the case of 1-SF.sub.5/Py the turnover frequencies (TGIF) are comparable. There are also several known methods for enhancing the activity of these neutral Ni (II) salicylaldiminato complexes. These include destabilising the resting state through ligand design, the use of less strongly coordinating ligands and removing the neutral ligand via phase transfer or addition of appropriate scavengers. The —SF.sub.5-substituent also has a significant effect on polymer properties. As the polymerisation temperature is increased, an increase in β-hydrogen elimination leads to a decrease in polymer melting temperature as branching increases (and molecular weight decreases). Compared with polymers produced using the CF.sub.3-analogs, this decrease in melting temperature is significantly reduced, which can be a significant advantage in certain polymer applications. While the melting temperatures of the polymers produced at 30° C. are comparable, the polymers produced using —SF.sub.5— complexes at 70° C. have melting temperatures 7 and 8° C. higher than those produced by CF.sub.3-analogs. The branches that are formed by the —SF.sub.5-substituted catalysts are shown by .sup.13C NMR to be exclusively methyl branches, showing that even after β-hydrogen elimination, chain walking is limited and subsequent insertions are fast. Furthermore NMR confirms the significant decrease in branching at higher temperatures for —SF.sub.5-substituted complexes. Unlike the CF.sub.3-analogs, 1-SF.sub.5/Py and 2-SF.sub.5/Py show very similar degrees of branching, despite the significantly different catalyst structures. Comparing 1-SF.sub.5/Py and 1-CF.sub.3/Py there are significant gains in molecular weight at all temperatures. Polymerisation at 50° C. (Table 1. Entries 2 and 5) is perhaps the clearest example of how effective this simple substitution can be with the introduction of —SF.sub.5-substituents leading to a tripling of molecular weight. With 2-SF.sub.5/Py and 2-CF.sub.3/Py a similar trend is seen, with polymerisations at higher temperatures (50, 70° C.) giving polymers with significantly higher molecular weights when 2-SF.sub.5/Py is used. Overall it is clear that the introduction of —SF.sub.5-substituents leads to a significant improvement in polymer properties, although there is a slight reduction in productivity.

(22) Polymerisation with the water soluble catalyst 1-SF.sub.5/TPPTS, were carried out to obtain dispersions of high molecular weight, linear polyethylene. Unlike the polymerisations in toluene, there does not seem to be a significant difference in productivity between —SF.sub.5- and CF.sub.3-substituted complexes in aqueous media. Adding CsOH (to suppress hydrolysis), increases the productivity of 1-CF.sub.3/TPPTS to the point where it is more productive than 1-SF.sub.5/TPPTS. Suggesting that in the absence of hydrolysis, 1-CF3/TPPTS may be more productive, as might be expected from the results in toluene. However it could also arise from the large amounts of free ligand present in the crude mixture of 1-SF.sub.5/TPPTS stabilising the catalyst.

(23) TABLE-US-00002 TABLE 2 Ethylene Polymerisation Results with Complex 1-SF.sub.5/TPPTS and its CF.sub.3-Analog, 1-CF.sub.3/TPPTS as Precatalysts in Water..sup.a M.sub.n Particle Yield [10.sup.3 T.sub.m Crystallinity Size Branches/ Entry Precatalyst [g] TON.sup.c g/mol].sup.d M.sub.w/M.sub.n.sup.d ° C.].sup.e [%].sup.e (nm).sup.f 1000 C..sup.g 1 1-SF.sub.5/TPPTS 3.20 2.30 1195 1.3 141/137 75/56 27 <0.7 .sup. 2.sup.b 1-SF.sub.5/TPPTS 3.95 2.85 1406 1.3 140/136 76/51 25 <0.7 3 1-CF.sub.3/TPPTS 2.18 1.56 428 1.2 137/132 72/58 22 2.6 .sup. 4.sup.b 1-CF.sub.3/TPPTS 4.62 3.30 501 1.2 136/131 75/53 29 2.4 .sup.aPolymerisation Conditions: 5 μmol of precatalysts, 100 mL H.sub.2O, 15° C., 1.5 g SDS, 40 bar of C.sub.2H.sub.4, 30 min. .sup.b100 mL H.sub.2O, 15° C., 3 g SDS, 512 mg CsOH•H.sub.2O, 60 min. .sup.c10.sup.4 × mol [C.sub.2H.sub.4] × mol.sup.−1 [Ni]. .sup.dDetermined by GPC at 160° C. .sup.eDetermined by DSC, 1.sup.st/2.sup.nd heating. .sup.fDetermined by DLS, volume average. .sup.gDetermined by .sup.13C NMR spectroscopy.

(24) Unlike the CF.sub.3-analog, complex 1-SF.sub.5ITPPTS produces a dispersion of polyethylene with the characteristic melt properties of linear ultra-high molecular weight polyethylene (UHMWPE) i.e. an exaggerated first melting temperature in the region of 140° C. while a melting temperature of ≈135° C. is obtained for all subsequent melting. Dispersions with these melting properties have been obtained previously as ‘ideal polyethylene nanocrystals’, however this required a lower polymerisation temperature of 10° C., to limit branching and the Mn was not exceeding 420.000 g/mol. Polymerisation at 10° C. is undesirable because at this temperature ethylene hydrate formation can lead to large temperature changes and destabilization of the polyethylene dispersion. At 10° C. polymerization is only possible for short reaction times through the use of additives (such as PEG) which can suppress ethylene hydrate formation. Complex 1-SF.sub.5/TPPTS is also significantly more productive than the catalyst used to produce ideal polyethylene nanocrystals, producing dispersions with higher polymer content at half the catalyst loading. Although the ‘ideal polyethylene nanocrystals’ synthesized previously showed similar melting behaviour to linear UHMWPE. They had a relatively low molecular weight (Mn=420 kg mol-1) compared to UHMWPE (Mn >500 kg mol-1). This disparity in melt behaviour and molecular weight is reduced by using complex 1-SF.sub.5/TPPTS. With this catalyst polyethylene with molecular weights (as Mn) of over 1,000 kg mol-1 are obtained, and with appropriate additives a gain in molecular weight of 1,000 kg mol-1 above the previous state of the art can be obtained (Table 2. Entry 2). Like other dispersions produced using this method of polymerisation, the polyethylene is produced in the form of highly organised crystals. Although the crystals produced by this catalyst are larger (<250 nm) and less uniform in size, a high crystallinity is maintained (575%) and that the polyethylene is disentangled is evident from the fact that an exaggerated first melting temperature is not observed when slow melting rates are used.

(25) Example with Ti as Transition Metal

(26) Ti-catalysts having the below pre-catalysts structures have been prepared.

(27) Pre-Catalyst Structures:

(28) ##STR00034##

(29) The catalyst having CF.sub.3 groups is a comparative catalysts, while the catalyst with —SF.sub.5 groups is a catalyst according to the present invention.

(30) Synthesis of TMS-Ligand:

(31) ##STR00035##
Synthesis of —SF.sub.5-Fl Ligand:

(32) Aminophenylsulfurpentafluoride (1.096 g, 5 mmol) and 3-tert-butylsalicylaldehyde (0.893 g, 5 mmol) were dissolved in toluene (6 mL) acidified with TsOH.H.sub.2O. This mixture was stirred at 70° C. overnight. After overnight stirring solvents removed to give an oily yellow solid, this was washed with methanol (2×5 mL) and yellow powder dried under high vacuum (1.49 g, 3.9 mmol, 79%).

(33) ##STR00036##

(34) .sup.1H NMR (400 MHz, CDCl.sub.3): δ 13.04 (br s, 1H) OH, 8.50 (s, 1H) 5, 7.91 (dd, J=8.4, 1.3 Hz, 1H) 1, 7.59 (td, J=7.7, 1.4 Hz, 1H) 3, 7.49 (dd, J=7.7, 1.7 Hz, 1H) 8, 7.37 (t, J=7.9 Hz, 1H) 2, 7.30 (dd, J=7.7, 1.8 Hz, 1H) 6, 7.10 (m, 1H) 4, 6.93 (t, J=7.7 Hz, 1H) 7, 1.52 (s, 9H) 9.

(35) Synthesis of TMS-SF.sub.5-Fl Ligand:

(36) SF.sub.5-Fl ligand (1.25 g, 3.3 mmol) was dissolved in abs. THF (12 mL) and added to a schlenk containing NaH (450 mg). This was then stirred at 50° C. for 3 hours before addition of excess TMSCl (2.1 mL). The resulting decoloured mixture was allowed to stir for 2 hours before solvents were removed. Solids were re-suspended in pentanes (15 mL) and filtered. Removal of pentanes gave the product as a white solid (810 mg, 1.8 mmol, 54%).

(37) ##STR00037##

(38) .sup.1H NMR (400 MHz, CDCl.sub.3): δ 8.65 (s, 1H) 5, 8.03 (dd, J=7.7, 1.9 Hz, 1H) 6, 7.87 (dd, J=8.4, 1.3 Hz, 1H) 1, 7.52 (m, 2H) 3, 8, 7.28 (t, J=7.9 Hz, 1H) 2, 7.07 (t, J=7.7 Hz, 1H) 7, 6.94 (d, J=7.9 Hz, 1H) 4, 1.47 (s, 9H) 9, 0.31 (s, 9H) 10.

(39) Synthesis of (tBu_SF.sub.5_SA).sub.2TiCl.sub.2 Via Dehalosilylation:

(40) TMS-SF.sub.5-Fl ligand (271 mg, 0.6 mmol) was dissolved in toluene (3 mL) and added to a solution of TiCl.sub.4 (57 mg, 0.3 mmol) in toluene (1 mL). Solution immediately turned red and was left to stir for 3.5 hours. Solvents were removed under vacuum giving an oily red solid which was washed with pentanes (2×5 mL) giving a red/orange powder (85 mg, 0.1 mmol, 33%).

(41) .sup.1H NMR (400 MHz, C.sub.6D.sub.6): δ 7.85 (s, 2H), 7.47 (d, J=8.6 Hz, 2H) 7.30 (d, J=7.9 Hz, 4H) 6.87 (t, J=7.73 Hz, 2H), 6.74 (d, J=7.5 Hz, 2H), 6.66 (m, 4H), 1.46 (s, 18H).

(42) TABLE-US-00003 Temperature Yield TON T.sub.m Mn Mw Catalyst (° C.) (g) (×10.sup.3 Ti.sup.−1) (° C.) (kg mol.sup.−1) (kg mol.sup.−1) PDI CF.sub.3 70 0.070 2.5 >135 38 201 5.3 SF.sub.5 70 0.136 4.3 >135 149 438 2.9 Catalyst Loading: 1 μmol, Al:Ti = 750:1.
Polymerization Procedure

(43) Ethylene polymerizations with titanium catalysts in toluene were carried out in a 300 mL stainless steel mechanically stirred pressure reactor equipped with a heating/cooling jacket supplied by a thermostat controlled by a thermocouple dipping into the polymerization mixture. This reactor was placed under vacuum and backfilled with argon, this process was repeated three times at temperatures above 60° C. to ensure the reactor was thoroughly degassed before cooling to the desired temperature. 100 mL of distilled and degassed toluene was then cannula-transferred to the cooled reactor and stirred at 500 rpm. 0.5 mL MAO-10T (750 μmol) was then added to the reactor via syringe and allowed to stir. 1 μmol of the appropriate precatalyst was then added via syringe. The stirring speed was increased to 1000 rpm and the reactor was pressurized to a constant pressure of 6 bar of ethylene. Ethylene flow to the reactor was stopped after 10 minutes and the reactor was carefully vented. Polymer was collected and stirred in methanol (acidified with HCl.), filtered, washed thoroughly with methanol and dried in a vacuum oven (50° C., 30 mBar) overnight.