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

A number of paramagnetic silylated d(1) group 4 metallates were prepared by reaction of potassium tris(trimethylsilyl)silanide with group 4 metallates of the type K[Cp2MCl2] (M = Ti, Zr, Hf). The outcomes of the reactions differ for all three metals. While for the hafnium case the expected complex [Cp2Hf{Si(SiMe3)(3)}(2)](-) was obtained, the analogous titanium reaction led to a product with two Si(H)(SiMe3)(2) ligands. The reaction with zirconium caused the formation of a dinuclear fulvalene bridged complex. The desired [Cp2Zr{Si(SiMe3)(3)}(2)](-) could be obtained by reduction of Cp2Zr{Si(SiMe3)(3)}(2) with potassium. In related reactions of potassium tris(trimethylsilyl)silanide with some lanthanidocenes Cp(3)Ln (Ln = Ce, Sm, Gd, Ho, Tm) complexes of the type [Cp(3)Ln Si(SiMe3)(3)](-) with either [18-crown-6 center dot K](+) or the complex ion [18-crown-6 center dot K center dot Cp center dot K center dot 18-crown-6] as counterions were obtained. Due to d(1) or f(n) electron configuration, unambiguous characterization of all obtained complexes could only be achieved by single crystal XRD diffraction analysis.