A systematic analysis of the structure-reactivity trends for some 'cation-like' early transition metal catalysts for dehydropolymerization of silanes

Article abstract of DOI:10.1016/0022-328X(96)06357-7

The use of 'cation-like' metallocene combination catalysts (Cp′₂MCl₂-2BuLi-B(C₆F₅)₃; Cp′ = η⁵-cyclopentadienyl, or substituted η⁵-cyclopentadienyl; M = Ti, Zr, Hf, U) for dehydropolymerization of silanes significantly improves the polymer molecular weight. For example, under the same conditions a Cp(C₅Me₅)ZrCl₂-2BuLi catalyst gives M_n = 1890, while a Cp(C₅Me₅)ZrCl₂-2BuLi-B(C₆F₅)₃ gives M_n = 7270. The influence of various factors (steric and electronic effects of the cyclopentadienyl ligands, the nature of the metal, temperature, solvent, concentration and structure of silane) on the build-up of polysilane chains are systematically analyzed.