Dioxidovanadium(V) complexes containing thiazol-hydrazone NNN-donor ligands and their catalytic activity in the oxidation of olefins

The reaction between tridentate NNN donor ligands, (E)-2-(2-(pyridin-2-ylmethylene)hydrazinyl)benzo [d]thiazole (HL1) and (E)-2-(2-(phenyl(pyridin-2-yl)methylene)hydrazinyl)benzo[d]thiazole (HL2), with VO(acac)(2) in ethanol gave [VO2(L-1)] (1) and [VO2(L-2)] (2) complexes. Complex [VO2(L-2)]center dot 0.2(H2O) (3) was produced from the reaction of HL2 and V2O5 in ethanol. Molecular structures of complexes were determined by single-crystal X-ray diffraction. All of the investigated compounds were further characterized by elemental analysis, FT-IR, UV-vis and NMR spectroscopy. The dioxidovanadium(V) species were used as catalysts for olefin oxidation in the presence of hydrogen peroxide (H2O2) as an oxidant. Under similar experimental conditions with equal vanadium loading, the presence of the [VO2(L-1)] (1) resulted in higher conversion than in the case of using [VO2(L-2)] (2) and [VO2(L-2)]center dot 0.2(H2O) (3) as catalytic agents. (C) 2016 Elsevier B.V. All rights reserved.