Transition metal complexes of a new hexadentate macroacyclic N2O4-donor Schiff base: Inhibitory activity against bacteria and fungi

A new hexadentate macroacyclic N2O4 – donor ligand, glyoxal bis(N-nitroso phenylglycine) (gbnp), has been designed and structurally characterized. Manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of gbnp have been prepared and characterized by elemental analyses, molar conductance measurements, magnetic moment, spectral (IR, 1H NMR, electronic and FAB mass) and thermal studies. The molecular dynamics of the ligand was studied by the variable temperature NMR studies, which suggest the presence of two isomeric forms. The antimicrobial activity of all the compounds was studied against Escherichia coli, Bacillus cirroflagellosus, Aspergillus niger and Candida albicans. Among the new complexes, copper(II) complex has the highest potential against all the microorganisms tested.

The new macroacyclic hexadentate ligand has potential binding sites towards metal ions, coordinating through two azomethine nitrogens, two amide carbonyl oxygens and two nitroso oxygens in N2O4 fashion.Figure optionsDownload as PowerPoint slide