Comparison of the coordination capabilities of thiodiacetate and oxydiacetate ligands through the X-ray characterization and DFT studies of [V(O)(tda)(phen)]•4H2O and [V(O)(oda)(phen)]•1.5H2O

The vanadium thiodiacetate complex [V(O)(tda)(phen)]center dot 4H(2)O (1) (tda = S(CH2COO)(2)(2-)) was obtained through reaction of aqueous [V(O)(acac)(2)] with thiodiacetic acid and subsequent addition of o-phenanthroline (phen). The structures of 1 and the analogous oxydiacetate compound [V(O)(oda)(phen)]center dot 1.5H(2)O (2) (oda = O(CH2COO)(2)(2-)) were characterized by X-ray crystallography and the geometric features of both ligands were compared in a similar environment. Additionally, both [V(O)(tda)(phen)] and [V(O)(oda)(phen)] were analyzed by theoretical calculations at the DFT level. Finally, the synthesis and X-ray characterization of the related oda-vanadium compound [V(O)(oda){(MeO)(2)bipy}] (3) ((MeO)(2)bipy = 4,4'-dimethoxy-2,2'-bipyridine) was also reported. (C) 2010 Elsevier Ltd. All rights reserved.