Characterization of the Titanium(III) Tris(alkyl) Ti{CH(SiMe3)2}3 and its Conversion to a Dimeric Alkyl-bridged Titanium(IV) Species.

The reaction of three equivalents of LiCH(SiMe3)2 with TiCl3(NMe3)2 afforded the rare homoleptic Ti(III) alkyl Ti{CH(SiMe3)2}3 (1) which crystallized as blue needles in 32 % yield. Single crystal X-Ray data for 1 showed a trigonal pyramidal coordination geometry around titanium, which could be ascribed to weak interactions between the C-H bonds and the Ti(III) atom based on computational results. X-band EPR spectroscopy give spectral parameters consistent with the proposed Ti(III) formulation. Solutions of 1 are unstable at room temperature owing to intramolecular C-H activation that gave a dimeric Ti(IV) complex [{(Me3Si)2HC}Ti{μ-CH HSiMe3}]2 (2).