Crystal Structure and DNA Interaction Property of COI) Complex with 4-Chloro-2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol

A new mononuclear copper complex [Cu(L)(5-Cl-sal)(DMF)]CIO4 center dot DMF (5-Cl-Hsal=5-chloro-salicylalde-hyde) has been designed and synthesized by phenanthroline derivatives 4-chloro-2-(1H-imidazo [4,5-f] [1,10] phenanthrolin-2-yl)phenol (HP. It was characterized by element analysis and X-ray single crystal diffraction. The crystal structure of complex belongs to triclinic system with space group P (1) over bar. Interactions of the complex with DNA binding have been investigated by absorption spectroscopy, fluorescence spectroscopy and agarose gel electrophoresis. The spectrophotometric studies show that the mode of binding of the complex could be intercalation and its binding constant K-b is 1.02x10(3) L.mol(-1). At the same time the complex can quench EB-DNA complexes to a large extent. The apparent binding constant value for the complex is 4.37x10(5) L.mol(-1), which is slightly less than the classical bond constant 10(7) L.mol(-1). In addition, the quenching mechanism of complex is dynamic quenching. The agarose gel electrophoresis showed that the complex can cleave circular pBR322 plasmid DNA to both nicked and linear forms with addition of hydrogen peroxide, and the higher the concentration, the better the cutting effect. The cleavage mechanism between the complex and plasmid DNA is likely to involve singlet oxygen O-1(2) and hydroxyl radical center dot OH as reactive oxygen species. CCDC: 702844.