Synthesis, Characterization and Antimicrobial Studies on Mn(II), Ni(II) and Co(II) Complexes of Amino Acid-Based Ligand
R. L. Danhalilu *
Department of Science Laboratory Technology, The Federal Polytechnic Kaura Namoda, Zamfara State, Nigeria.
I. A. Kankara
Department of Science Laboratory Technology, The Federal Polytechnic Kaura Namoda, Zamfara State, Nigeria.
K. S. Uthman
Department of Science Laboratory Technology, The Federal Polytechnic Kaura Namoda, Zamfara State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Amino acid ligand derived from the condensation reaction of histidine and acetophenone and its Mn(II), Ni(II) and Co(II) complexes were characterized by solubility test, melting point / decomposition temperature, elemental analysis, UV-visible spectroscopy, molar conductance, FTIR spectroscopy and magnetic susceptibility. Elemental analysis indicated 1:2 metal:ligand ratio. Percentage yield of the ligand is 62.84% with a melting point of 188ºC. The percentage yields of the complexes were 89.98%, 57.64% and 81.82% for Mn(II), Ni(II) and Co(II) complexes respectively. The decomposition temperatures of the complexes were in the range of 208-222ºC, low molar conductance values of the complexes indicated their non-electrolytic nature. The values of the magnetic moments (5.9BM, 4.0BM and 4.3BM) showed that they are paramagnetic. The ligand and its complexes were tested against bacterial isolates; S. aureus & S. typhi and fungal isolates; C. albicans and A. flavus, using the disc diffusion method. The results indicated that the ligand and its metal(II) complexes exhibited activity at different concentrations against all the species tested.
Keywords: Amino acid ligand, histidine, bacterial isolates, fungal isolates, antimicrobial activity