Ruthenium (ii) Schiff Base: Complexes, Physico-chemical, Spectrometric, Microbial and Dna Binding and Cleaving Studies

Stable ruthenium(II) carbonyl complexes having the general composition [Ru(CO) (PPh3)(py)(L)] (where L= bianion of tridentate Schiff bases (H2L, H2L and H2L)) were synthesized from the reaction of [RuHCl(CO)(PPh3)2(py)] with bidentate Schiff base ligands derived from condensation of isatin with o-aminophenol / o-aminothiophenol / o-aminobenzoic acid. The new complexes were characterized by elemental analysis, Mass spectra, IR, UV-Vis and H, C and P NMR spectral data. The redox property of the complexes were studied by cyclic voltammetric technique. An octahedral geometry has been assigned tentatively for all the complexes. In all the above reactions, the Schiff bases replaces a hydride and chloride ion and PPh3 from the starting complexes, which indicate that the Ru–N bonds present in the complexes containing heterocyclic nitrogen bases are stronger than the Ru–P. These complexes were also subjected to study their biocidal activity against S. epidermidis and E. coli. Some of the complexes show higher efficiency when compared with the standard (Ciprofloxacin and Co-trimoxazole). DNA (Herring Sperm) binding behaviour of the complex [Ru(L)(CO)(PPh3)(py)] has been studied by electronic spectra, cyclic voltammetric, differential pulse voltametric (DPV), circular dichorism and gel electrophoresis techniques.