Full Length Research Paper

Synthesis, physico-chemical and antimicrobial properties of Co(II), Ni(II) and Cu(II) mixed-ligand complexes of dimethylglyoxime - Part I

A. A. Osunlaja¹*, N. P. Ndahi¹ and J. A. Ameh²

¹Department of Chemistry, University of Maiduguri, Maiduguri, Borno State, Nigeria.

²Department of Veterinary Microbiology, University of Maiduguri, Maiduguri, Borno State, Nigeria.

*Corresponding author. E-mail: Osunlajasolidrock@yahoo.com. Tel: 08026549872.

Accepted 17 October, 2008

Some mixed-ligand complexes of the general formula [M(Hdmg)₂B], where Hdmg = dimethylglyoximato monoanion, B = 2-aminophenol, diethylamine or malonic acid were prepared. The complexes were characterized by metal analysis, melting points, solubility, conductivity, infrared and UV/VIS electronic spectra. The antimicrobial activities of he complexes were tested using Escherichia coli, staphylococcus aureus, Aspergillus niger and Aspergillus flavus. The complexes melted/decomposed at 120 - 306°C and, most of them dissolved only in polar solvents. The complexes are mostly dark-brown or black. The IR spectra indicated that the complexes coordinated, through the N atom of the oxime group of Hdmg, and O atoms of the 2-aminophenol or malonic acid. In the electronic spectra of the complexes, the absorption bands observe in the UV/VIS region are presumed to be either due to charge transfer or intra-ligand transitions form the ligands or d-d transitions form the metal ions. The complexes showed antimicrobial activity against the tested micro-organisms at 10 mg/ml. The possible used of he complexes as antibiotic can therefore be suggested.

Key words: Dimethylglyoxime, UV/Visible spectroscopy, infrared spectroscopy, antimicrobial activities.