Synthesis, characterization, and DNA binding study of ruthenium(II/III) complexes containing ONS donor Schiff base.

A chelating ligand of thioether with ONS donor Schiff base HL [(E)-2-(((2-(benzylthio)phenyl)imino)methyl)napthalen-1-ol] and its metal complexes (RuL1 and RuL2) have been synthesized. They have been characterized by UV-Vis, FTIR, 1H NMR, 13C NMR, mass spectrometry methods. The formulas of the synthesized compounds have been confirmed by elemental analysis and magnetic susceptibility measurements. The binding ability studies of the ligand (HL) and its Ru complexes (RuL1 and RuL2), with calf-thymus DNA have been explored by the absorption titration method. The binding interaction study reveals that the ligand (HL) and the complex RuL1 interact with CT-DNA through an intercalative mode of binding whereas the complex RuL2 does not show any interaction with CT-DNA due to steric effect.