Template Synthesis of Polyaza Macrocyclic Copper(II) and Nickel(II) Complexes: Spectral Characterization and Antimicrobial Studies

The template synthesis of copper(II) and nickel(II) complexes derived from 2,6-diformyl-4-methylphenol with diethylenetriamine or 1,2-bis(3-aminopropylamino)ethane produce the 12-membered N3O and 17-membered N4O macrocyclic complexes, respectively. The geometry of the complexes has been determined with the help of electronic and EPR spectroscopic values and found to be five coordinated square pyramidal and, six coordinated distorted tetragonal for 12-membered and 17-membered macrocyclic complexes, respectively. Electrochemical studies of the mononuclear N3O and N4O copper(II) complexes show one irreversible oneelectron reduction wave at Epc = –1.35 and –1.15 V respectively, and the corresponding nickel(II) complexes show irreversible one-electron reduction wave at Epc = –1.25 and –1.22 V, respectively. The nickel(II) complexes show irreversible one-electron oxidation wave at Epa = +0.84 and +0.82 V, respectively. All the complexes were evaluated for in vitro antimicrobial activity against the human pathogenic bacteria and fungi.