DNA-binding, catalytic oxidation, CC coupling reactions and antibacterial activities of binuclear Ru(II) thiosemicarbazone complexes: Synthesis and spectral characterization

New hexa-coordinated binuclear Ru(II) thiosemicarbazone complexes of the type {[(B)(EPh3)(CO)ClRu]2L} (where, E = P or As; B = PPh3 or AsPh3 or pyridine; L = mononucleating NS donor of N-substituted thiosemicarbazones) have been synthesized and characterized by elemental analysis, FT-IR, UV–vis and 31P{1H} NMR cyclic voltammetric studies. The DNA-binding studies of Ru(II) complexes with calf thymus DNA (CT-DNA) were investigated by UV–vis, viscosity measurements, gel-electrophoresis and fluorescence spectroscopy. The new complexes have been used as catalysts in CC coupling reaction and in the oxidation of alcohols to their corresponding carbonyl compounds by using NMO as co-oxidant and molecular oxygen (O2) atmosphere at ambient temperature. Further, the new binucleating thiosemicarbazone ligands and their Ru(II) complexes were also screened for their antibacterial activity against Klebsiella pneumoniae, Shigella sp., Micrococcus luteus, Escherichia coli and Salmonella typhi. From this study, it was found out that the activity of the complexes almost reaches the effectiveness of the conventional bacteriocide.