New insights into the chemistry of oxovanadium (IV) complexes with tetradentate macrocyclic ligands

Macrocyclic ligands derived from condensation of 1,2-diaminopropane or 1,4-diaminobutane with furil and their reaction with β-diketones (viz. acetylacetone, benzoylacetone, thenoyltrifluroacetone and dibenzoylmethane) in the presence of vanadyl ion is reported. The oxovanadium(IV) complexes having general formula [VO(mac)]SO4 have been designed and synthesized using vanadyl ion as template without which these complexes might not be formed. The prepared macrocyclic complexes were characterized by elemental analyses, molar conductance, magnetic moments, infrared, electronic and electron spin resonance data. From the spectroscopic studies, five coordinated with square-pyramidal geometry for the VO(IV) complexes have been proposed wherein derived ligands act as tetradentate chelating agents.