PREPARATION AND CHARACTERIZATION OF (R2N)(2)VCL2 [R=CY,I-PR] AND ITS ACTIVITY AS OLEFIN POLYMERIZATION CATALYST

Reaction of VCl3(THF)(3) with one equivalent of R2NLi [R = i-Pr, Cy] f ormed the tetravalent (R2N)(2) VCl2 [R = i-Pr (1a), Cy (1b)] which was isolated in crystalline form. The formation of these species is likel y to be ascribed to a disproportionation reaction since a divalent van adium complex, VCl2(TMEDA)(2) complex was isolated upon treatment of t he reaction mixtures with TMEDA. Complexes 1 can be alkylated with RLi to yield the corresponding (R2N)(2)VR2 (2) derivatives in good yield. Preliminary data on ethylene-propylene (EP) co-polymerization obtaine d with compounds 1 in conjunction with various aluminum alkyl compound s are described. (C) 1998 Elsevier Science S.A. All rights reserved.