Bio-Mimetic Catalase-like Activity, Corrosion Inhibition, Antibacterial, DFT and Spectroscopic Characterization of Mixed Ligand Complexes of 1,10-Phenanthroline with Dibasic Benzoin Schiff Base Ligand

Four novel mix ligand complexes of manganese(II), iron(III), cobalt(II) and nickel(II) with dibasic tetra dentate Schiff base ligand BENZOEN and 1, 10-phenanthroline have been synthesized with the general composition of [M(BENZOEN)(1,10-phen)], where M = Mn(II), Co(II), Ni(II) and [Fe(BENZOEN)(1,10-phen)]Cl. The synthesized ligand and complexes were characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility, ESIMS spectrometry, electronic spectra, FT-IR, H NMR and C NMR spectroscopy. Theoretical computation and combined experimental theoretical characterization were carrying out by Gaussian 09 software package using density functional theory (DFT) method to confirm the geometry of the investigated compounds. Additionally, molecular electrostatic potential map (MEP), HOMO, LUMO, NBO and Mullikan charge analysis were also been performed. Spectroscopic chracterization and DFT study proposed a distorted octahedral structure of complex 1-4. In vitro biomimetic catalase activity of the ligand and complexes was done by measuring amount of dioxygen evolve. Saturation kinetics of H2O2 decomposition was fitted to the Michaelis-Menten equation and Lineweaver-Burk plot. The antibacterial activity of the ligand and complexes against Escherichia coli shows complexes were found more potent than the BENZOEN. MIC of complexes shows that complex 2 is more active than other complexes even at lower concentration.