Thermal studies on the adducts of bis(benzoylacetonato)oxovanadium(IV) with substituted pyridines

Abstract

Spectroscopic, magnetic and analytical studies on the adducts of bis(benzoylacetonato)oxovanadium(IV) with nitrogen donors have been previously reported. It was observed that the change in the substituent on the pyridine ring was accompanied by changes in the spectral parameters. Therefore it was of interest to investigate the thermal stability of the adducts with heterocyclic nitrogen donors of different steric requirements. The DTA curves corresponding to the decomposition of the adducts showed only a single endothermic peak. The mass loss accompanying the endothermic transition corresponded, on the TG curve, to the loss of one molecule of the ligand. From the DSC curves, activation energies have been calculated and the relationships between the activation energies and the enthalpies of the processes with the nature of the metal—ligand bond have been studied.