Studies on the Interaction of Cobalt Mixed-Ligand Coordination Compound Containing Tetrapyrido [3,2-a: 2' 3'-c: 3″ 2″ h: 2'″, 3'″-j] phenazine with DNA

A new monometallic complex [Co(phen)2tpphz]3+ (where tpphz is tetrapyrido [3,2-a: 2',3'-c: 3″,2″-h: 2'″,3'″-j] phenazine) was synthesized by the reaction of 5,6-diamino-1,10-phenanthroline with [Co(phen)2(phendione)]3+. It was characterized by elemental analysis, molar conductivity, IR, 1H NMR, ultraviolet and fluorescence spectroscopy. The interaction of the complex with DNA was also investigated. The complex shows the absorption hypochromicity, fluorescence enhancement, the specific viscosity increased when bound to calf thymus DNA. The cyclic voltammetry (CV) measurement showed a change in peak current with the addition of DNA. All the results provide the support for the intercalative binding mode of the mononuclear complex.