Synthesis and DNA binding behavior of a dipyridocatecholate bridged dicopper(II) complex

1,10-Phenanthroline-5,6-diol (dpcatH2) was prepared conveniently from 1,10-phenanthroline-5,6-dione using hydrazine sulfate as reductant, and a new bimetallic Cu(II) complex, [(phen)Cu(dpcat)Cu(phen)](ClO4)2, where phen denotes 1,10-phenanthroline was synthesized by a “one-pot” method. Presence of calf thymus DNA would result in an evident change in the electronic absorption, quenching effect on the fluorescence, protection from fluorescence quencher ferrocyanide and disappearance of redox process of the complex, and the viscosity of DNA would be enhanced by addition of the complex. All these facts suggest that the dicopper(II) complex binds to double helix DNA by classical intercalation.