Dehydrogenative polymerization of silanes to polysilanes by zirconocene and hafnocene catalysts. A new polymerization mechanism

Article abstract of DOI:10.1021/ja00202a070

We have found that a number of zirconium and hafnium siyl complexes of the type Cp′₂M(SiR₃)R′ (Cp′ = η⁵-C₅H₅, Cp (η⁵-C₅Me₅); M = Zr, Hf; R = Me, Ph, SiMe₃; R′ = Cl, alkyl, silyl) are catalyst precursors for this dehydrogenative coupling reaction and that polymer molecular weights can vary as a function of reaction conditions and catalyst. Improvement of this method relies heavily on an understanding of the polymerization mechanism, which has remained obscure. This report describes observations that suggest a mechanism for dehydrogenative silane polymerization by zirconocene and hafnocene catalysts.