Binding studies of some novel macroacyclic transition metal complexes towards CT-DNA via multispectroscopic techniques

C. Joel1, *S. Theodore David1,

Abstract

A novel macroacyclic N2O2 based Schiff base ligand (L), obtained by the condensation of 9,10-phenanthrenequinone and 1,8-diaminonaphthalene, has been used to synthesize the mononuclear complexes of the type [M(L)]Cl2 [M= Co(II), Ni(II), Cu(II) and Zn(II)]. The newly synthesized ligand (L) and its complexes have been characterized with the help of elemental analyses, conductance measurements, electronic, 13C-NMR, infrared and mass spectral studies. The formation of macroacyclic framework has been inferred from the appearance of imine (C=N) and (MN) band in IR spectra and the signal observed in 13C-NMR spectra. The stoichiometry and the nature of the complexes have been deduced from the results of elemental analyses and conductance data. The structural distortion in Cu(II) complex has been deduced on EPR data. The electrochemical behaviour of the Cu(II) complex has been studied by cyclic voltammetry. Absorption, Fluorescence, circular dichroism and viscosity measurement studies on the complexes proved a significant binding to calf thymus DNA.