Synthesis, characterization and crystal structure determination of a new oxovanadium(IV) Schiff base complex: The catalytic activity in the epoxidation of cyclooctene

A new oxovanadium(IV) Schiff base complex, (VOL2)-O-IV (1), was prepared by the reaction of a bidentate Schiff base ligand L and VO(acac)(2) (L=N-salicylidin-2-chloroethylimine). The Schiff base ligand, L, and its oxovanadium(IV) complex, 1, were characterized by the elemental analysis (CHN) and FT-IR spectroscopy. In addition, H-1-NMR was employed for characterization of the ligand. The crystal structure of 1 was determined by the single crystal X-ray analysis. The Schiff base ligand L acts as a chelating ligand and coordinates via one nitrogen and one oxygen atom to the vanadium center. The complex 1 crystallizes in the monoclinic system, with space group P2(1)/n, having one symmetry-independent V4+ ion coordinating in an approximately square pyramidal N2O3 geometry by two imine nitrogen, two phenolato oxygen atoms from two Schiff base ligands in a square plane and one oxygen atom in an apical position. The catalytic activity of the complex 1 was tested in the epoxidation of cyclooctene. The results showed that the complex 1 was highly active and selective catalyst in optimized conditions in the epoxidation of cyclooctene. (C) 2012 Elsevier B.V. All rights reserved.