Molecular structure of a mono-peroxo vanadium(V) complex formed by _D _,_L-lactic acid

Abstract

The peroxo complex formed by vanadium(V) in the presence of D ,L-lactic acid (H2lact) as heteroligand, K2[{VO(O2)(lact)}2], is described. A single-crystal X-ray diffraction study indicates that the ligand behaves as a bidentate chelator adopting the (O-, COO-) donor set. The complex has a dinuclear core based on the V2O2 cyclic arrangement arising from two vanadium(V) atoms sharing the hydroxyl oxygens of two ligands. The coordination sphere of each vanadium includes two hydroxyl oxygens, an oxygen atom from a carboxylate group, an oxo ligand and two peroxo oxygens. The geometry at the metal ion is severely distorted and, in the ideal limit, it could be described as a trigonal bipyramid, in which one of the equatorial bonds corresponds to the axis joining the vanadium atom and the centre of the peroxo group. A strikingly short interatomic O---O distance, 1.35 Å, is measured for the peroxo group, suggesting both σ- and π-donor ability in the bonding to the metal ion