Preparations, Structures, and Properties of Sulfato-Bridged Dinuclear and Tetranuclear Vanadium(III) Complexes with a Dinucleating Ligand, 2-Oxo-N,N′-bis(2-pyridylmethyl)-1,3-propanediamine-N,N′-diacetate

New dinuclear and tetranuclear vanadium(III) complexes with sulfato bridge(s), [{V III (H20)}2(μ-hpnbpda)-(μ-OH)(μ-SO 4 )].5.25H 2 O (1) and [V III 4(μ-hpnbpda) 2 (μ-OH) 2 (μ-SO 4 ) 2 ]·12H 2 O (2), where hpnbpda is an alkoxobridging dinucleating ligand, 2-oxo-N,N'-bis(2-pyridylmethyl)-1,3-propanediamine-N,N'-diacetate, were prepared, and their structures were determined by X-ray crystallography. The vanadium(III) center in 1 adopts heptacoordinate structure while that in 2 has a hexacoordinate structure. In 2, the two dinuclear vanadium(III) units bridged by the alkoxo group of hpnbpda are further linked by two hydroxo and two sulfato bridging groups, resulting in a dimer-of-dimers structure. Measurement of the temperature dependence of the magnetic susceptibility of 1 revealed that the two vanadium(III) ions are antiferromagnetically coupled with J = -5.9 cm -1 and g = 1.90.