The preparation and crystal and molecular structures of trichlorobis(methyldiphenylphosphine)vanadium(III) and its acetonitrile adduct

Abstract

The complex [VCl₃(PPh₂Me)₂] has been prepared from [VCl₃(MeCN)₃] or [VCl₃(thf)₃](thf = tetrahydrofuran) and the tertiary phosphine in toluene. In the crystal there are two independent trigonal-bipyramidal molecules with axial phosphine ligands. There is considerable distortion from regular co-ordination polyhedra and mean bond distances are V–Cl, 2.22 and 2.23 Å and V–P, 2.54 and 2.53 Å. On long reflux of a solution of [VCl₃(MeCN)₃] and PPh₂Me in toluene, the complex [VCl₃(MeCN)(PPh₂Me)₂] is obtained. It contains six-co-ordinate vanadium(III) with meridional V–Cl bonds of average length 2.30 Å. Other bond distances are V–N, 2.140(3)Å and V–P, 2.56 Å(av.).