Group 4 Metal and Lanthanide Complexes in the Oxidation State +3 with Tris(trimethylsilyl)silyl Ligands.

A number of paramagnetic silylated d group 4 metallates were prepared by reaction of potassium tris(trimethylsilyl)silanide with group 4 metallates of the type K[CpMCl] (M = Ti, Zr, Hf). The outcomes of the reactions differ for all three metals. While for the hafnium case the expected complex [CpHf{Si(SiMe)}] was obtained, the analogous titanium reaction led to a product with two Si(H)(SiMe) ligands. The reaction with zirconium caused the formation of a dinuclear fulvalene bridged complex. The desired [CpZr{Si(SiMe)}] could be obtained by reduction of CpZr{Si(SiMe)} with potassium. In related reactions of potassium tris(trimethylsilyl)silanide with some lanthanidocenes CpLn (Ln = Ce, Sm, Gd, Ho, Tm) complexes of the type [CpLn Si(SiMe)] with either [18-crown-6·K] or the complex ion [18-crown-6·K·Cp·K·18-crown-6] as counterions were obtained. Due to d or f electron configuration, unambiguous characterization of all obtained complexes could only be achieved by single crystal XRD diffraction analysis.