Two Copper(II) Complexes with Tridentate Polypyridyl Ligands:Synthesis,Characterization and Their Interaction with DNA

Two copper(Ⅱ) complexes [Cu(phpi)Cl2]·H2O (1) and [Cu(tpy)Cl2]·2H2O (2) (phpi=2-(benzimidazol-2)-1,10-phenanthroline,tpy=2,2:6′,2″-terpyridine) were synthesized and characterized by elemental analysis,molar conductivity,IR and UV spectroscopy. The interaction of the two complexes with DNA was also studied by electronic absorption spectroscopy,ethidium bromide (EB) fluorescence spectroscopy,viscosity and gel electrophoresis measurements. It was found that the two complexes could cause significant cleavage of double-strand pBR322 DNA in the presence of ascorbic acid. In addition,the mechanism of DNA cleavage was primarily suggested.