Preparation and Characterization of Tris(trimethylsilyl)silyl and Tris(trimethylsilyl)germyl Derivatives of Zirconium and Hafnium. X-ray Crystal Structures of (Eta5-C5Me5)Cl2HfSi(SiMe3)3 and (Eta5-C5Me5)Cl2HfGe(SiMe3)3

摘要

Our investigations of early transition metal silyl compounds have shown that the reactivity of early metal-silicon bonds can be dramatically influenced by changes of substituents at both the metal and silicon. For example, whereas Cp2Zr(SiMe3)Cl1a(Cp = eta5-C5H5) and CpCp Zr(Si(SiMe3)3)l1b,e (Cp = eta5-C5Me5) combine rapidly with carbon monoxide to form eta2-COSiR3 derivatives, Cp2Zr(Si(SiMe3)3)l1a is unreactive toward CO under similar conditions. This implies that elucidation of structure-reactivity correlations can be very important in the development of this area. Presently studies directed toward this goal are complicated by the fact that relatively few early transition-metal silyl complexes have been described. All reported zirconium and hafnium silyls are 16- or 18-electron metallocene derivatives of the type(eta5-C5R5)(eta5-C5R5)M(SiR3)X (R, R = H, Me). Clearly, thorough investigations of the chemistry of early transition-metal-silicon bonds will rely on efficient synthetic routes to a range of complexes. Hafnium compounds, Silicon, Silanes, Chlorine compounds, Reprints. (mjm)