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 fr om a solution of [V(IV)O(sal-gly)(H2O)] (2) (sal-gly = N-salicylideneg lycinate) and bipyridyl. Its structure has been determined by X-ray di ffraction analysis. There is one molecule per unit cell and its centre lies at a crystallographic inversion centre. The vanadium atoms lie o n the corners of a diamond-shaped planar unit and each of the two inde pendent vanadium atoms V(1) and V(2) are octahedrally coordinated. The tetramer contains a V4O8 core, two mu3-OCH3, two CH3O- and two bipy l igands. The magnetic susceptibility was measured and data could be fit ted to a chi(p) = A + C/T function with A = 9.087 x 10(-5) emu mol-1 a nd C = 1.809 x 10(-3) emu K mol-1.