Properties, structure and stability of V(IV) hydrazide Schiff base ligand complex

The reaction of vanadyl sulfate, VOSO4 center dot H2O, with Schiff base ligand based on 2-hydroxybenzhydrazide and 5-bromosalicylaldehyde, with addition of 1,10-phenantroline as co-ligand, in ethanolic solution results in isolation of oxovanadium(IV) complex [VO(phen)L]center dot H2O (1). The complex was characterized by elemental analysis, single crystal X-ray structure measurements, IR, UV-Vis, EPR spectroscopy and cyclic voltammetry. Magnetic susceptibility measurements indicated the +4 vanadium oxidation state. The molecular structure of the complex was confirmed by single-crystal X-ray diffraction, revealing that the central vanadium atom was located in a six-coordinate distorted octahedral geometry. The stability of the complex at native pH and pH = 2.00 was also measured and the results are promising for application the vanadium complex as insulin mimetic compound. (C) 2018 Elsevier B.V. All rights reserved.