The Interaction of DNA with Phenanthroline and New Phenanthrocyanine Complexes of Zn(II)

The interaction of DNA with complexes of Zn(II) and 1,10-phenanthroline derivatives in aqueous salt solutions has been studied by the optical spectroscopy, fluorescence, and DNA melting methods. Bis-(1,10-phenanthroline)-(1,10-phenanthrocyanine)-dizinc (II) acetate (diZn) and its precursor, bis-(1,10-phenanthroline)-zinc (II) acetate (monoZn) have been used. The interaction of DNA with phenanthroline significantly differs from that with phenanthroline metal complexes. MonoZn and diZn form complexes with DNA. Depending on the molar ratio of the components, ligands may interact with DNA in several ways; one of these is presumably intercalation. No saturation binding was detected at 0.1 ≤ r ≤ 20 and 0.1 ≤ r ≤ 1.67 for monoZn and diZn, respectively. The formation of secondary complexes of monoZn and diZn with DNA is possible. The interaction with DNA leads to quenching the fluorescence of the metal complexes.