Synthesis, characterization and crystal structures of vanadium(V) complexes derived from halido-substituted tridentate hydrazone compounds with antimicrobial activity

Three new chlorido-substituted hydrazone compounds N'-(3,5-dichloro-2-hydroxybenzylidene)benzo-hydrazide (H2L1), N'-(3,5-dichloro-2-hydroxybenzylidene)-4-fluorobenzohydrazide (H2L2) and N'-(2hydroxy-3-methylbenzylidene)-4-trifluoromethylbenzohydrazide (H2L3), were prepared and characterized by IR, UV-Vis and H-1 NMR spectra. Based on the hydrazone compounds, three new vanadium(V) complexes, [VOL1(OEt)(EtOH)center dot[VOL1(OEt)(MeOH)] (1), [VOL2(OEt)(EtOH)] (2) and [VOL3(OEt)(EtOH)] (3), were prepared and characterized by IR and UV-Vis spectra, as well as single crystal X-ray diffraction. X-ray analysis indicates that the complexes are mononuclear vanadium(V) species, with the V atoms coordinated in octahedral geometry. The hydrazone compounds and their vanadium complexes were evaluated against the bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence, and the fungi Candida albicans and Aspergillus niger. The existence of the fluoro groups in the hydrazone ligands can improve the antibacterial activities. (C) 2018 Elsevier Ltd. All rights reserved.