CATALYTIC DEHYDROCOUPLING OF PHENYLSILANE WITH CATION-LIKE ZIRCONOCENE DERIVATIVES - A NEW APPROACH TO LONGER SILICON CHAINS

The use of tris(pentafluorophenyl)borane, (C6F5)3B, as a cocatalyst in the dehydrocoupling of phenylsilane, in the presence of zirconocene-d erived catalysts, leads to suppression of chain scission reactions and to an increase in polysilane chain length (M(n) > 7000). An exhaustiv e multinuclear NMR study of the catalytic species leads to the conclus ion that they are zirconocene(IV) hydride bridged dimers, with a ''cat ion- like'' silylium ligand on each zirconium: [CP2Zr(SiHPh)(mu-H)]2[B u2-(C6F5)2B]2.