Tris{(diphenylphosphino)dimethylsilyl}methane: a sterically hindered tripod
The synthesis and characterization of a new tripodal tris(phosphine) molecule, HC(Me2SiPPh2)3 (3) is described. The impact of dimethylsilyl "elbows" on the conformational preferences of this tris(dimethylsilyl)methane core in solution and in the solid state was assessed for 3 and its precursor HC(Me2SiBr)3 (2). Hindered rotation around the "arms" of 3, evident from its solid state structure, has been probed in solution by variable temperature, 1H{31P} NMR spectroscopy, and molecular modelling studies based on the solid state structure of 2 also indicate significant barriers to rotation in this molecule. The susceptibility of 3 to cleavage of the P-Si bonds by protic reagents is described.Key words: tripodal tris(phosphine), polyphosphine, trisilylmethane, C3-symmetry.