Conformational change of ternary copper(II) complexes of cationic Schiff-bases and N-heteroaromatic amines induced by intercalative binding to DNA

DNA-fiber EPR spectra revealed that intercalative binding of the ternary copper(II) complexes of cationic Schiff-bases and N-heteroaromatic amines induced the rearrangement of coordination spheres of the complexes from tetragonal pyramidal to square planar geometries. The binding of the complexes was also characterized by UV–vis, CD and fluorescence spectroscopy together with DFT calculation of the conformational change. The synergetic effect of the intercalation, the electrostatic interaction and the rearrangement of the coordination spheres enhanced the oxidative and the photodynamic DNA cleavage activities.