Mateescu, C.Voyiatzis, G.Kaliva, M.Raptopoulou, C. P.Salifoglou, A.Terzis, A.Gabriel, C.Ζερβού, ΜαρίαWASHINGTONDiverse vanadium biological activities entail complex interactions with physiological target ligands in aqueous media and constitute the crux of the undertaken investigation at the synthetic level. Facile aqueous redox reactions, as well as nonredox reactions, of V(III) and V(V) with physiological citric acid and hydrogen peroxide, under pH-specific conditions, led to the synthesis and isolation of a well-formed crystalline material upon the addition of ethanol as the precipitating solvent Elemental analysis pointed to the molecular formulation (NH4)(4)[(VO2) {VO(O-2)}(C6H5O7)(2)]center dot 1.5H(2)O (1). Complex 1 was further characterized by Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (MAR), Raman spectroscopy, cyclic voltammetry, and X-ray crystallography. The crystallographic structure of 1 reveals the presence of the first dinuclear V(V)-citrate complex with non-peroxo- and peroxo-containing V(V) ions, concurrently present within the basic (V2O2)-O-v core. The nonperoxo unit VO2+ and the peroxo unit VO(O-2)(+) are each coordinated to a triply deprotonated citrate ligand in a distinct coordination mode and coordination geometry around the V(V) ions. These units are similar to those in homodinuclear complexes bearing oxo or peroxo groups. The unique assembly of both units in the anion of 1 renders the latter as a potential intermediate in the peroxidation process, from [V2O4(C6HSO7)(2)](4-) to [V2O2(O-2)(2)(C(6)H(6)O7)(2)](2-). The transformation reactions of 1 establish its connection with several V(V) and V(IV) dinudear species present in the aqueous distribution of the V(IV,V)-citrate systems. The shown position of 1 as an intermediate in the mechanism of H2O2 addition to dinudear V(V)-citrate species portends its role in the complex aqueous distribution of species in the ternary V(V)-peroxocitrate system and its potential reactivity in (bio)chemically relevant media.Adobe PDF11423-1143610.1021/ic201204s0020-1669https://hdl.handle.net/10442/12555engAmerican Chemical Society© AMER CHEMICAL SOC© AMER CHEMICAL SOCInorganic ChemistryChemistry, Inorganic & NuclearA Unique Dinuclear Mixed V(V) Oxo-peroxo Complex in the Structural Speciation of the Ternary V(V)-Peroxo-citrate System. Potential Mechanistic and Structural Insight into the Aqueous Synthetic Chemistry of Dinuclear V(V)-Citrate Species with H2O2Άρθρο σε επιστημονικό περιοδικό2011-11-21Δημοσίευση σε περιοδικόPublication in journalΧημείαChemical sciencesFrascati 42Επιστημονικό άρθροScientific articleΕθνικό Ίδρυμα Ερευνών (ΕΙΕ)Greek Aggregator OpenArchives.gr | National Documentation Centre (EKT)