Synthesis, spectroscopy, electrochemistry and thermal study of vanadyl unsymmetrical Schiff base complexes

The new tetradentate unsymmetrical N2O2 Schiff base ligands and VO(IV) complexes were synthesised and characterized by using IR, UV–Vis and elemental analysis. The electrochemical properties of the vanadyl complexes were investigated by means of cyclic voltammetry. The oxidation potentials are increased by increasing the electron-withdrawing properties of functional groups of the Schiff base ligands according to the trend of MeO < H < Br < NO2. The thermogravimetry (TG) and differential thermoanalysis (DTA) of the VO(IV) complexes were carried out in the range of 20–700 °C. The complexes were decomposed in two stages. Also decomposition of synthesised complexes is related to the Schiff base characteristics. The thermal decomposition of the studied reactions was first order.