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 (H 2lact) as heteroligand, K 2[{VO(O 2)(lact)} 2] ( 1), 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 V 2O 2 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.