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[Cp 2 MCl 2 ] (M = Ti, Zr, Hf). The outcomes of the reactions differ for all three metals. While for the hafnium case the expected complex [Cp 2 Hf{Si(SiMe 3 ) 3 } 2 ] - was obtained, the analogous titanium reaction led to a product with two Si(H)(SiMe 3 ) 2 ligands. The reaction with zirconium caused the formation of a dinuclear fulvalene bridged complex. The desired [Cp 2 Zr{Si(SiMe 3 ) 3 } 2 ] - could be obtained by reduction of Cp 2 Zr{Si(SiMe 3 ) 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(SiMe 3 ) 3 ] - 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 1 or f n electron configuration, unambiguous characterization of all obtained complexes could only be achieved by single crystal XRD diffraction analysis.