Synthesis, Characterization and Crystal Structures of Oxidovanadium(V) Complexes with Schiff Base and Pyrone Ligands and Their Antimicrobial Activity

Abstract

Two oxidovanadium(V) complexes, [VOLL a ] (1) and [VOLL b ] (2), where L is the dianionic form of the Schiff base ligand 2-(((2-hydroxyethyl)imino)methyl)-6-methylphenol (H 2 L), L a and L b are the deprotonated forms of 3-hydroxy-2-methyl-4H-pyran-4-one (HL a) and 2-ethyl-3-hydroxy-4H-pyran-4-one (HL b), respectively, have been prepared and characterized by elemental analyses, IR, UV−Vis, 1 H NMR and single−crystal X−ray crystallographic determination. The V atoms in the complexes are in octahedral coordination, with the Schiff base ligand mer-coordinated to the metal atoms through the phenolate O, imino N and hydroxyl O atoms, and with the pyrone ligands coordinated to the metal atoms through the two O atoms. The effect of the compounds on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.

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

“…calc. for C 16 71, 163.20, 152.57, 134.30, 131.99, 131.78, 131.20, 130.75, 130.62, 127.77, 127.12, 122.56, 119.50, 119.38, 74.43, 48.58. Λ M (10 -3 M in methanol): 37 Ω -1 cm 2 mol -1 .…”

“…7c Moreover, when compared with the vanadium complexes with chloro and fluoro-containing hydrazone ligands, both complexes are to some extent have higher MIC values. 7b,15 When compared with the vanadium complexes with Schiff base ligand 2-(((2-hydroxyethyl)imino)methyl)-6-methylphenol and the pyrone ligands 3-hydroxy2methyl-4H-pyran-4-one or 2-ethyl-3-hydroxy-4H-pyran-4-one, 16 and the vanadium complexes with the ligands N'- (5-chloro-2-hydroxybenzylidene)pivalohydrazide and 3-hydroxy2-methyl-4H-pyran-4-one or 2-ethyl-3-hydroxy-4H-pyran-4-one, 17 the complexes 1 and 2 in this work is weaker for the bacteria S. aureus, E. coli, and C. albicans. 16 The present complexes have higher activities against B. subtilis, S. aureus and E. coli, when compared with the vanadium complex with the ligands N'-(3-bromo-2-hydroxybenzylidene)picolinohydrazide and 2-hydroxybenzohydroxamate.…”