Toru Tsukahara, and Dale C. Swenson, R. F. Jordan
Jul 22, 1997
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0
Influential Citations
67
Citations
Journal
Organometallics
Abstract
The reaction of Zr(CH2Ph)4 with the pyridine alcohols 6-pyCR1R2OH (2a, R1 = R2 = CF3; 2b, R1 = R2 = Me; 2c, R1 = H, R2 = CF3) yields dibenzyl complexes (pyCR1R2O)2Zr(CH2Ph)2 (3a−c). These species adopt distorted octahedral structures with a trans-O, cis-N, cis-C ligand arrangement but undergo rapid inversion of configuration at Zr on the NMR time scale, with racemization barriers in the range from 8.6 (3b) to 10.1 (3c) kcal/mol. 3a and 3b react with B(C6F5)3 to yield [(pyCR1R2O)2Zr(CH2Ph)][PhCH2B(C6F5)3] (6a,b) and with [HNMe2Ph][B(C6F5)4] to yield [(pyCR1R2O)2Zr(CH2Ph)][B(C6F5)4] (7a,b). NMR spectra indicate that 6a,b and 7a,b are not strongly ion-paired in CD2Cl2. 6a polymerizes ethylene and 1-hexene to low molecular weight polymers. [{pyCH(CF3)O}2Zr(CH2Ph)][PhCH2B(C6F5)3] (6c, generated in situ) is much less active for ethylene polymerization than 6a, and 6b is inactive.