Nonoxido and oxido vanadium complexes featuring O- and N- donor ligands in relation to biological and catalytic activities

Abstract

Synthesis, X-ray structure and characterization of three highly stable, hexacoordinated nonoxido vanadium(IV), VIV(L)2, complexes with tridentate aroylhydrazonates containing ONO- donor atoms have been reported. All the complexes are stable in open air in the solid state as well as in solution, a phenomenon rarely observed in nonoxido vanadium(IV) complexes. The complexes have good solubility in organic solvents, permitting electrochemical and various spectroscopic investigations. The existence of nonoxido vanadium(IV) complexes was confirmed by elemental analysis, ESI mass spectroscopy, cyclic voltammetry, EPR and magnetic susceptibility measurements. X-ray crystallography showed the N2O4 donor set to define a trigonal prismatic geometry in each case. All the complexes show in vitro insulin mimetic activity against insulin responsive L6 myoblast cells. In addition, the in vitro antiproliferative activity of all the complexes against HeLa cell line was assayed, where the complexes found to show good cytotoxic activity.