Synthesis, characterization and antimicrobial properties of Cobalt(III), Nickel(III), Copper(II) and Zinc(II) complexes with pyridine and thiocyanate

Mixed-ligand complexes of Co(III), Ni(III), Cu(II) and Zn(II) with pyridine and thiocyanate have been synthesized and characterized using elemental analysis, infrared and UV-Vis spectroscopy, thermal analytical techniques, melting point determination, molar conduc-tivity and room temperature magnetic susceptibility measurements. The results suggest that all complexes are stable and molecular with octahedral coordination geometry for the Co(III) and Ni(III) complexes, square planar or tetrahedral geometry for the Cu(II) complex and a tetrahedral geometry for the Zn(II) complex. Evaluation of the antimicrobial activities of the ligands, metals salts and complexes on four bacterial strains ( E. Coli, K.Pneumonia, S.typhi and S. flexneri) and four fungal strains (C. Albicans, C., Parapsilopsis, C. tropicalis and C. neoformans) showed higher activity of the complexes compared to the ligands and met-als salts. The Co(III) complex showed higher activity than the reference drugs; doxycycline and Penicillin while the Cu(II) complex showed higher activity than the reference antibi-otics; doxycycline and nystatin. (c) 2022 The Authors. Published by Elsevier B.V. on behalf of African Institute of Mathematical Sciences / Next Einstein Initiative. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )