Oxovanadium (IV) Complexes of α-Amino Acid Schiff Bases and Polypyridyl Ligands: Synthesis, Characterization and Antimicrobial Activity

Oxovanadium(IV) complexes of the type [VO(L)(bpy)] (V-1 to V-5) have been synthesized and characterized by FTIR and UV-Vis spectra, molar conductance, melting points, and magnetic susceptibilities measurements, where L= N-salicylidene-β-alanine (sal-ala), N-salicylidene-glycine (sal-gly), N-salicylidene-DL-β-phenylalanine (sal-pheala), N-salicylidene-leucine (sal-leu), and N-salicylidene-DL-methionine (sal-met), and bpy is 2,2´-bipyridine. The infrared spectral data reveals that the tridentate nature of the amino acid-based Schiff base ligand and the coordination of the ligand through azomethine nitrogen, phenolic oxygen and carboxylate oxygen with vanadyl (VO2+) ion. All of these complexes were determined to be non-electrolyte in nature, according to conductivity measurements. The magnetic moment measurements have been attributed that these complexes are paramagnetic and have d1 configuration of vanadium (IV) ion. In Virto antimicrobial activity of the synthesized complexes was evaluated against two gram-positive (Bacillus subtilis and Staphylococcus aureus) and two gram-negative (Escherichia coli, Proteus vulgaris) bacterial strains.