RESEARCH ARTICLE THE EFFECT OF COUNTERION ON THE DNA BINDING OF TRANS - (RU(DMSO) 2 CL 4 ).(9 - AMINOACRIDIDE), (RU(DMSO) 3 CL 3 ).(N - ETHYLMORPHOLINE) AND (RU(DMSO) 3 CL 3 )

Several acridine and morpholine derivatives are well known for their antimicrobial properties and also for good DNA binding through intercalation. Moreover, dimethyl sulphoxide ( DMSO) molecule contributes to the reduction of cell growth and terminal differentiation of transformed cells. trans [RuCl 4 (dmso) 2 ](9 - aminoacridine) and [RuCl 3 (dmso) 3 ](N - ethylmorpholine) were synthesised and DNA binding ability of these complexes were studied. The molecular structure of the complexes was determined from single crystal X - ray diffraction study. Binding of these complexes with plasmid - DNA was studied by UV - Visible and Emission spectral techniques and further electrochemical studies were also performed . The evidences of DNA binding were found from the change of the Intensity of fluorescence band, stern - volmer constant, shift in λ max . and redox potentials. Binding constants (K b ) calculated from UV - spectroscopic titration are found to be 1.37 x 10 4 M - 1 and 4.6 x 10 4 M - 1 respectively.