Pure and Applied Chemistry

Abstract: A review discussing general structural features of oxygen-bridged dinuclear vanadium(IV and/or V) complexes is presented, covering those that have been characterized by single-crystal X-ray diffraction. Many of these compounds contain functional Schiff bases or amines as ligands, this work illustrating the high propensity of the V center to increase its coordination number via dimerization of two tetra- or penta-coordinate monomers, if the steric and electronic control exerted by the ligands allows it. We also report the synthesis and characterization by single-crystal X-ray diffraction of two new dinuclear complexes: [{V^VO[sal(R,R-chen)]}₂(μ₂-O)₂] and [{V^VO[mvan(S,S-chen)]}₂(μ₂-O)₂]. The complexes contain tridentate ligands with O-phenolate, N-imine, and N-amine coordination to the V^V center. The molecular structures of these compounds demonstrate that they form dinuclear species in the solid state with a {OV^V(μ₂-O)₂V^VO} core.