Highly efficient divanadium(V) pre-catalyst for mild oxidation of liquid and gaseous alkanes

A new binuclear oxovanadium(V) complex bearing an NO2-donor Schiff base ligand, [{VO(EtO)(EtOH)}(2)(1 kappa O-2,kappa N:2 kappa O-2,kappa N-L)]center dot 2H(2)O (H4L=bis(2-hydroxybenzylidene)oxalohydrazonic acid) was prepared and fully characterized by IR, H-1 NMR and electronic spectroscopies, elemental analysis and single crystal X-ray diffraction. In the presence of 2-pyrazinecarboxylic acid (PCA) or another acid promoter, this compound acts as a highly efficient pre-catalyst towards the oxidation of gaseous and liquid alkanes by aqueous H2O2 under mild conditions, in aqueous MeCN. Total yields of oxygenates up to 45% and overall turnover numbers up to 7.8 x 10(3) are achieved. (C) 2013 Elsevier B.V. All rights reserved.