Characterization and biological activities of two copper(II) complexes with diethylenetriamine and 2,2′-bipyridine or 1,10-phenanthroline as ligands

Two new mixed ligand copper(II) complexes with diethylenetriamine, 2,2′-bipyridine and 1,10-phenanthroline have been synthesized. The crystal and molecular structures of [Cu(dien)(phen)](ClO4)2 and [Cu(dien)(bipy)](BF4)2 (dien = diethylenetriamine, phen = 1,10-phenanthroline, bipy = 2,2′-bipyridine) were determined by X-ray crystallography from single crystal data. These two complexes have similar structures. The EPR spectral data also suggest that these complexes have distorted square pyramidal geometry about copper(II). Anti-microbial and superoxide dismutase activities of these complexes have also been measured. They show the higher SOD activity than the corresponding simple Cu(II)-dien/Cu(II)-PMDT (PMDT = N,N,N′,N′,N″-pentamethyldiethylenetriamine) complexes because of a strong axial bond of one of the nitrogen atoms of the α-diimine. Both the complexes have been found to cleave plasmid DNA in the presence of co-reductants such as ascorbic acid and glutathione.