Synthesis,characterization, crystal structure,catalytic activity in oxidative bromination,and thermal study of a new oxidovanadium Schiff base complex containing O,N-bidentate Schiff base ligand

A new oxidovanadium(IV) Schiff base complex, VOL₂ (1), HL = 2-{(E)-[2- (bromoethyl)imino]methyl}-6-methoxy phenol, containing ethyl bromide pendant group was synthesized by direct reaction of HL and VO(acac)₂ in the ratio of 2 : 1 in methanol at reflux. The Schiff base ligand and its vanadyl complex were characterized by FT-IR spectra and CHN analysis. Additionally, the Schiff base ligand has been characterized by ¹H NMR spectroscopy. The crystal structure of 1 was also determined by single-crystal X-ray analysis, showing the distorted square-pyramidal N₂O₃ coordination around vanadium(IV). The catalytic activity of 1 was studied in the oxidative bromination of 2-nitrophenol as a model substrate, and different reaction parameters were investigated. The oxidative bromination of some organic compounds in the presence of 1 in optimal conditions showed that it was an effective and selective catalyst in those optimal conditions. Thermogravimetric analysis of 1 showed that it decomposed in two stages. 1 was thermally decomposed in air at 660 °C, and the XRD pattern of the obtained solid showed the formation of the V₂O₅ nanoparticles with average size of 34 nm .