Study on the interaction of a palladium complex with DNA

The complex [Pd(bipy)Cl2] (1) (bipy = 2,2′-bipyridyl) has been synthesized and characterized by NMR spectroscopy, elemental analysis and X-ray diffraction method. The first step hydrolysis reaction kinetics for the complex was studied by UV-absorption spectroscopy; the speed constant (k1) was found to be 3.0×10−4 s−1. The fluorescence spectra have been collected to investigate the interaction of complex (1) with fish sperm DNA (FS-DNA) and the results indicate that the complex (1) has an effective intercalation within DNA. The reaction of complex (1) with adenine in ethanol/water results in the compound [Pd2(bipy)2(ade)2]Cl2·3H2O (2) (ade = adenine) whose crystal structure was determined by X-ray diffraction method. The structure is orthorhombic, Pmmn, a = 12.993(4) Å, b = 14.512(5) Å, c = 9.837(3) Å, V = 1854.8(11) Å3, Z = 2 (C30H30Cl2N14O3Pd2), final R1 = 0.0675. The palladium complex is a binuclear cation, where two ade ligands bridge two Pd(II) centers, while each Pd(II) is also chelated by one bipy ligand.