摘要:
Bimetallic titanium and zirconium complexes with bridges (X) between Cp ligands were compared to Cp2MCl2 as catalysts in the presence of (BuLi)-Bu-n for the dehydrocoupling of PhSiH3 to polyphenylsilane. The monobridged bimetallic complexes developed were of the composition [mu-X(C5H4)(2)][CpMCl2](2) with X = Me2Si (M = Ti, Zr), Me2SiCH2SiMe2 (M = Ti) and Me2SiCH2CH2SiMe2 (M = Ti, Zr). The dibridged bimetallic complexes examined were of the type [mu,mu-(Me2Si)(2)(C5H3)(2)][Cp'TiCl2](2) (Cp' = Cp trans isomer, Cp' = Cp*, Irans and cis isomers). There was not a significant difference in the molecular weight of the polysilane produced from Cp2TiCl2 and the bimetallic titanium complexes after 48 h of reaction. However, the polysilane which was generated from the bimetallic complex [mu-(Me2Si)(C5H4)(2)][CpZrCl2](2) was approximately twice the molecular weight compared to that obtained from Cp2ZrCl2. The structure of the bimetallic complex [mu-(Me2SiCH2CH2SiMe2)(C5H4)(3)][CpZrCl2](2) was determined by X-ray diffraction (monoclinic, P2(1)/n, a = 8.7297(3)Angstrom, b = 6.7890(2) Angstrom, c = 24.9343(7) Angstrom, beta = 93.7850(10)degrees, Z = 2).