Structural studies of eight-co-ordinate metal complexes. Part I. Crystal and molecular structures of tetrakis(phenyldithioacetato)vanadium(IV) and tetrakis(dithiobenzoato)vanadium(IV)

Abstract

The structures of tetrakis(phenyldithioacetato)vanadium(IV)(I) and tetrakis(dithiobenzoato)vanadium(IV)(II), have been determined by X-ray methods. Crystals of (I) are triclinic, space group P, with a= 9·86(3), b= 11·395(5), c= 16·124(5)Å, α= 77·4(4)°, β= 101·0(4)°, γ= 106·1 (4)°, Z= 2. The structure was solved from 1831 photographic data by direct methods, and refined by block-diagonal least squares to R 0·119. Crystals of (II) are tetragonal, space group I4₁/a with a=b= 47·887(3), c= 6·72(2)Å, Z= 20. The structure was solved by use of 3120 reflections collected by automatic diffractometer, and by Patterson and Fourier techniques, and refined by least squares to R 0·078. Vanadium is eight-co-ordinate in both compounds, the ligands acting as bidentate chelates. The VS₈ co-ordination polyhedra approximate very closely to that of the dodecahedron, with chelation over the m edges (D_2d 2m isomers).