Synthesis, structure and characterization of oxovanadium(IV) Schiff base complexes with tetradentate macrocyclic ligands

Two types of new oxovanadium(IV) complexes having general formula [VO(mac)]SO4 were designed and synthesized using vanadyl ion as template with ligands derived from condensation of 2,2’-pyridil or 1,1’-oxalyldiimidazole with 2,3-diamino-5-bromopyridine and their reactions with β-diketones such as acetylacetone, bezoylacetone, thenoyltrifluoroacetone and dibenzoylmethane are carried out to get macrocyclic complexes. Tentative structures of the complexes have been proposed on the basis of elemental analyses, molar conductance, magnetic moments and spectral (infrared, electronic and electron spin resonance) data. All the oxovanadium(IV) complexes are five coordinate wherein the ligands act as tetradentate chelating agents.