Synthesis and X-ray structural characterization of tris(L-glycinato) vanadium(III) and trans-tetraquadichlorovanadium(III) chloride

Despite the importance of V(III) in biology, only three V(III) complexes of naturally occurring amino acids have been structurally characterized. We report the structure of the. rst vanadium complex incorporating a glycine ligand, [V(Gly)(3)] center dot 2DMSO, which crystallizes in a monoclinic system with space group Cc, a = 8.9186(5) angstrom, b = 21.5347(9) angstrom, c = 9.9064(5) angstrom and beta = 110.536(3)degrees. The X-ray structural data show the central V(III) metal octahedrally coordinated by three bidentate glycinato ligands arranged a mer configuration, with both Delta and Lambda enantiomers present in the unit cell. The bulk sample was isolated as [V(Gly)(3)] center dot DMSO center dot NaCl. Structural comparisons are made with the corresponding homoleptic glycinato complexes of Co(III), Cr(III) and Ni(II). The structure of trans-[V(OH(2))(4)Cl(2)] Cl center dot 2H(2)O has also been re-determined. This latter complex crystallizes in a monoclinic system in the P(2)(1)/c space group, a = 6.4381(9) angstrom, b = 6.3843(9) angstrom, c = 11.7980(17) angstrom and beta = 98.057(2)degrees. The vanadium atom lies at a crystallographic inversion centre within the distorted octahedron formed by the four water and two chloride ligands. (C) 2007 Elsevier B. V. All rights reserved.