Syntheses, characterization, crystal structures, and antimicrobial activity of oxidovanadium(V) complexes with hydrazone and pyrone ligands

A pair of new oxidovanadium(V) complexes, [VOLL1] (1) and [VOLL2] (2), where L is the dianionic form of the hydrazone ligand N′-(2-hydroxy-3-methoxybenzylidene)-3-methylbenzohydrazide (H2L), L1 and L2 are the deprotonated form of 3-hydroxy-2-methyl-4H-pyran-4-one (HL1) and 3-hydroxy-2-ethyl-4H-pyran-4-one (HL2), respectively, have been prepared and characterized by elemental analyses, IR, UV-Vis, 1H NMR and single crystal X-ray determination. The V atoms in the complexes are in octahedral coordination, with the hydrazone ligand coordinates to the metal atoms through the phenolate O, imino N, and enolate O atoms, and with the pyrone ligands through the carbonyl and hydroxyl O atoms. The effect of the compounds on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.