Two Vanadium(V) Complexes Derived from Bromo and Chloro-Substituted Hydrazone Ligands: Syntheses, Crystal Structures and Antimicrobial Property

Abstract

Two vanadium(V) complexes derived from the bromo and chloro-substituted hydrazones N'-(4-bromo-2-hydroxybenzylidene)-2-chlorobenzohydrazide (H₂L¹) and N'-(3-bromo-5-chloro-2-hydroxybenzylidene)-3-methylbenzohydrazide (H₂L²) with the formula [VOL¹(OCH₃)(CH₃OH)] (1) and [VOL²(OCH₃)(CH₃OH)] (2) were newly synthesized and characterized by IR, UV-Vis and ¹H NMR spectroscopy. The structures of H₂L¹ and the complexes were further confirmed by single crystal X-ray diffraction. Both vanadium complexes are mononuclear, with the metal atoms coordinated by the hydrazone ligands, methanol ligands, and methanolate ligands, and the oxo groups, forming octahedral geometry. The hydrazones and the vanadium complexes were assayed for the antimicrobial activities on Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence, and the fungi Candida albicans and Aspergillus niger. The existence of the bromo and chloro groups in the hydrazone ligands may improve the antimicrobial property.