SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF A POLYOXOVANADATE COORDINATION COMPLEX [V4O8(CH3O)4(BIPY)2] WITH A TETRAMETALLATE CORE

A vanadium(V) tetramer, [V4O8(CH3O)4(bipy)2] (1), has been isolated from a solution of [V(IV)O(sal-gly)(H2O)] (2) (sal-gly = N-salicylideneglycinate) and bipyridyl. Its structure has been determined by X-ray diffraction analysis. There is one molecule per unit cell and its centre lies at a crystallographic inversion centre. The vanadium atoms lie on the corners of a diamond-shaped planar unit and each of the two independent vanadium atoms V(1) and V(2) are octahedrally coordinated. The tetramer contains a V4O8 core, two mu3-OCH3, two CH3O- and two bipy ligands. The magnetic susceptibility was measured and data could be fitted to a chi(p) = A + C/T function with A = 9.087 x 10(-5) emu mol-1 and C = 1.809 x 10(-3) emu K mol-1.