Synthesis, Characterization and Antimicrobial Studies on Mn(II), Ni(II) and Co(II) Complexes of Amino Acid-Based Ligand

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.