Synthesis, spectroscopic, structural and antimicrobial studies of a dimeric complex of copper(II) with trichloroacetic acid and metronidazole

In this work, we report the synthesis and characterization of a novel dimeric complex Cu-2(mu-TCA)(2)(TCA)(2)(MET)(4) [where TCA = trichloroacetic acid; MET = metronidazole]. The reaction was carried out M room temperature to obtain a blue crystalline compound. The complex was characterized by elemental analysis, electronic spectroscopy, FT-IR, High-Field EPR and X-ray crystallography. The complex crystallized in the triclinic system with a = 11.3749(6), b = 11.8752(7), c = 12.3307(7) angstrom, and space group P-1. Each Cu centre in the complex is in a square pyramidal environment. High-Field EPR investigations, combined with DFT calculations, revealed very weak interactions between the Cu2+ ions in the centrosyrnmetric dimer. The biological potency of the complex has been tested by using bacterial strains, Escherichia coll., Salmonella typhi, Klebsiella pneumonia, Micrococcus luteus, Staphylococcus aureus and yeast Candida albicans strain and compared with metronidazole and trichloroacetic acid. In vitro antibacterial activities of the complex and the parent ligands were examined using agar diffusion method. The newly synthesized copper complex showed some antibacterial activity against some strains compared to each parent ligands used. Moreover, a significant inhibition was observed in the action of the copper complex against yeast Candida albicans.