Rapid, Highly Linear-Selective Dehydrocoupling of Phenylsilane with New Group 4 Metallocene-Based Combination Catalysts

The dehydrocoupling of phenylsilane with Cpʹ2MCl2/Red-Al (Cpʹ = C5H5 or C51Me5; M = Ti, Zr, Hf; Red-Al = Na[H2AI(OCH2CH2OMe)2]) combination catalysts rapidly produces linear polyphenylsilanes, and the linear selectivity drastically decreases in the order of Cp(C5Me5)Hf > Cp2Hf > Cp(C5Me5)Zr > Cp2Zr > Cp2Ti; in the presence of solvent (neat > toluene > THF) and 4 A molecular sieve; with heating.