Synthesis, Spectroscopic, Molecular Modeling and Anti-Fungal Studies of Some Divalent Metal Complexes of 4-Hydroxyacetophenone Isonicotinoyl Hydrazone

Abstract

A novel ligand N-4-hydroxyacetophenone isonicotinoyl hydrazone and its manganese(II) and nickel(II) metal complexes have been synthesized. The synthesized Schiff base and its metal complexes have been characterized by physical state determination, melting point and solubility measurements in different solvents, infrared, proton nuclear magnetic resonance, mass spectrometric and powder X-ray spectroscopic techniques. The thermal properties of the prepared compounds were obtained from TG/DTG measurements. On the basis of the analytical techniques, the ligand was found to be bidentate in nature coordinating to the metal ions through the azomethine nitrogen and carbonyl oxygen atoms leading to distorted octahedral geometries of the metal complexes which were modeled using MM2 force field. The ligand and its metal(II) complexes were evaluated for antifungal activity against Aspergillus fumigatus, Aspergillus niger, Candida albicans and Rhizopus stolonifera. The antifungal evaluation results revealed an enhanced activity upon coordination of the ligand with the metal(II) ions. The activity of the metal complex to the tested fungal strains was in the order Ni(II) > Mn(II).