Synthesis, Crystal Structures and Antimicrobial Activity of Oxidovanadium(V) Complexes with Hydrazone and Pyrone Ligands

Ling-Wei Xue,Yong-Jun Han,Xiao-Qiang Luo

doi:10.17344/acsi.2019.5039

Abstract

A pair of oxidovanadium(V) complexes, [VOLL1] (1) and [VOLL2] (2), where L is the dianionic form of the hydrazone ligand N'-(5-chloro-2-hydroxybenzylidene)pivalohydrazide (H2L), L1 and L2 are the deprotonated forms of 3-hydroxy-2-methyl-4H-pyran-4-one (HL1; maltol) and 2-ethyl-3-hydroxy-4H-pyran-4-one (HL2; ethyl maltol), respectively, have been prepared and characterized by elemental analyses, IR and UV-Vis spectroscopy, and single-crystal X-ray crystallographic determination. The V atoms in the complexes are in octahedral coordination, with the hydrazone ligand coordinated to the V atoms through the phenolate O, imino N and enolate O atoms, and with the pyrone ligands coordinated to the V atoms through two O atoms. The effect of the compounds on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.

Highlights

Schiff bases are important ligands in coordination chemistry.[1]
The hydrazone compound H2L was prepared by the condensation of equimolar quantities of 5-chlorosalicylaldehyde with pivalohydrazide in methanol
The V atoms are in octahedral coordination, with the three donor atoms of the hydrazone ligand, and the hydroxyl O atom of the pyrone ligand defining the equatorial plane, and with the carbonyl O atom of the pyrone ligand, and the oxo O group occupying the axial positions

Summary

Introduction

Schiff bases are important ligands in coordination chemistry.[1]. In recent years, metal complexes of Schiff bases have attracted remarkable attention due to their versatile biological activity, such as antifungal, antibacterial and antitumor.[2]. Two oxidovanadium(V) complexes, [VOLL1] (1) and [VOLL2] (2), where L is the dianionic form of the hydrazone ligand N’-(5-chloro-2-hydroxybenzylidene)pivalohydrazide (H2L), L1 and L2 are the deprotonated form of 3-hydroxy-2-methyl-4H-pyran-4-one (HL1; maltol) and 2-ethyl-3-hydroxy-4H-pyran-4-one (HL2; ethyl maltol), respectively, are reported. Xue et al.: Synthesis, Crystal Structures and Antimicrobial Activity ...

Results

Conclusion