Metal ion-directed synthesis of 16-membered tetraazamacrocyclic complexes and their physico-chemical studies

Complexes of Co(II), Ni(II), Cu(II) and Zn(II) containing macrocyclic tetradentate nitrogen donor (N4) ligand have been synthesized from the template condensation reaction between o-phthalaldehyde and o-phenylenediamine. The newly synthesized ligand and its complexes have been characterized on the basis of results of elemental analysis, molar conductance, magnetic susceptibility measurements, FT-IR, electronic, 1H FT NMR spectral data and Job's method. Their thermal behaviour has been studied by the thermogravimetric analysis. An octahedral geometry has been proposed for all of these complexes except the copper complexes, which show distorted octahedral geometry. The low conductivity data suggest their non-ionic nature. The biological activities of the metal complexes have also been studied against different bacteria.