SYNTHESIS, CHARACTERIZATION AND PHYSICOCHEMICAL PROPERTIES OF PEROXO-VANADIUM(V) COMPLEXES WITH GLYCINE AS THE HETEROLIGAND

The first glycineperoxo complexes of vanadium- (V), NH4[VO(O2)2GlyH]·H2O (1), K[VO(O2)2- GlyH]·H2O (2)and [V2O2(O2)3(GlyH)2(H2O)2] (3) have been synthesised from the reaction of V2O5 with hydrogen peroxide and glycine (GlyH) at pH 3-4 (1 and 2) and pH 2 (3), respectively. The compounds have been characterised by elemental analysis, magnetic susceptibility and ESR, UVVis and IR spectroscopy. While glycine, occurring in its zwitterionic form, is coordinated to the V(V) centre in a monodentate fashion through its carboxylic oxygen, the peroxides in 1 and 2 occur as terminal bidentate ones. In compound 3 one of the peroxide ligands is present as a μ-peroxo group. Typically, an aqueous solution of 2 exhibits peroxoV(V) LMCT bands at 328 and in the 200-190 nm region, whereas complex 3 shows only one broad LMCT band at 310-330 nm. © 1990.