Abstract: Two Schiff base ligands, 4-nitrobenzaldehyde - ethylenediamine (L1) and acetophenone - ethylenediamine (L2) and their Cr(III) and Mn(II) complexes have been prepared. Characterization of the ligands and complexes was made by the elemental analysis, magnetic susceptibility, mass spectra, IR, 1H NMR, UV-visible spectral studies. The complexes have been found to posses 1:1 (M:L) stoichiometry. The electronic spectral data and magnetic moment measurement suggest octahedral geometry of these complexes. Kinetic and thermodynamic parameters were computed from the thermal data using Coats and Redferm method which confirm first order kinetics. The bioefficacy of the ligands and their complexes have been examined against the growth of bacteria and pathogenic fungi in vitro to evaluate their anti-microbial potential. The results indicate that the ligands and their metal complexes possess notable antimicrobial properties.
 

Keywords: Biological activities, spectra, Schiff base, Cr(III), Mn(II) complexes, thermal decomposition kinetics