Synthesis, structural characterization and DNA interaction studies on a mononuclear copper complex: Nuclease activity via self-activation

Mononuclear copper(II) complex [Cu(Pyimpy)(Cl)(ClO4)] has been synthesized from a tridentate ligand Pyimpy (Pyimpy = 1-phenyl-1-(pyridin-2-yl)-2-(pyridin-2-ylmethylene)hydrazine) and characterized by elemental analysis, electronic absorption and IR spectroscopy. Molecular structure of 1 was determined by single crystal X-ray diffraction. Structural index parameter (tau) calculation supported distorted square pyramidal geometry around the metal centre. The stabilization of copper(II) centre was examined by electrochemical studies. DNA interaction studies were investigated by absorption spectral studies and EthBr displacement assay. Nuclease activity studies afforded cleavage of pBR322 plasmid DNA via self-activating mechanism. Investigation of mechanism indicated the possible role of reactive oxygen species in DNA cleavage. (C) 2011 Elsevier B.V. All rights reserved.