Synthesis and spectroscopic characterization of tris{(diphenylphosphino) dimethylsilyl}methane complexes of cr(0) and w(0)

Abstract

Treatment of M(CO)6 (M = Cr, W) with (Ph2PMe2Si)3CH in toluene at elevated temperatures resulted in the isolation of pale green [Cr(CO)3{(Ph2PMe2Si)3CH}] and pale brown [W(CO)3{(Ph2PMe2Si)3CH}] in high yield. These complexes have been characterized by elemental analysis, conductivity measurements, TGA, mass spectrometry, and IR, electronic, 1H and 31P{1H} NMR spectroscopy. The complexes have pseudo octahedral geometry around the metal atom with tridentate coordination of the multidentate ligand. The six-membered MPSiCSiP metallacycles are shown to have high fluxionality at room temperature on the NMR time scale.