Spectroscopic, catalytic, and biological studies on mononuclear ruthenium(II) ONSN chelating thiosemicarbazone complexes

Abstract

A group of new ruthenium(II) thiosemicarbazone complexes, [Ru(CO)(B)(L)] (where B = PPh₃/AsPh₃/Py; L = dibasic tetradentate Schiff-base ligand), have been synthesized by reacting [RuHCl(CO)(PPh₃)₃], [RuHCl(CO)(AsPh₃)₃], and [RuHCl(CO)(Py)(PPh₃)₂] with the Schiff base in 1 : 1 molar ratio in an ethanol–benzene mixture. These complexes have been characterized by elemental analysis, FT-IR, UV-Vis, NMR, and mass spectroscopy. The redox behaviors of the complexes have been investigated by cyclic voltammetry. These complexes have been examined for their catalytic efficiency for aryl–aryl coupling and oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of oxygen. All the complexes were screened for their antibacterial activity. Further, one complex was tested for its binding with calf thymus-DNA using absorption spectroscopic studies and viscosity measurements.

Keywords:

• Thiosemicarbazone
• Molecular oxygen
• Aryl–aryl coupling
• Antibacterial
• DNA-binding