Synthesis, characterization and DNA binding studies of new ruthenium(II)bisterpyridine complexes

Two new ruthenium(II) complexes, [Ru(itpy)(2)](PF6)(2), 1 and [Ru(bitpy)(2)](PF6)(2) 2, were synthesized and characterized by ESI-Mass, UV-Visible, H-1 NMF, fluorescence spectroscopy and cyclic voltammetry. Complex 1 has been characterized crystallographically. Interaction of these complexes with CT-DNA has been studied using absorption and CD spectra. Absorption spectral titration and CD spectral measurements show that complex 1 binds with DNA through intercalation. Complex 2 on the other hand shows dual mode of binding to DNA, groove binding as well as intercalation. Photo nuclease activity of these complexes has been studied using agarose gel electrophoresis and both the complexes have been shown to exhibit photonuclease activity. However, complex 1 has been found to show higher DNA cleaving efficiency compared to complex 2. (C) 2009 Elsevier Masson SAS. All rights reserved.