Synthesis, characterization, DNA binding and catalytic applications of Ru(III) complexes

A new series of azodye ligands 5-chloro-3-hydroxy-4-(aryldiazenyl)pyridin-2(1H)-one (HLn) were synthesized
by coupling of 5-chloro-3-hydroxypyridin-2(1H)-one with aniline and its p-derivatives. These
ligands and their Ru(III) complexes of the type trans-[Ru(Ln)2(AsPh3)2]Cl were characterized by elemental
analyses, IR, 1H NMR and UV–Visible spectra as well as magnetic and thermal measurements. The molar
conductance measurements proved that all the complexes are electrolytes. IR spectra show that the
ligands (HLn) acts as a monobasic bidentate ligand by coordinating via the nitrogen atom of the azo group
(AN@NA) and oxygen atom of the deprotonated phenolic OH group, thereby forming a six-membered
chelating ring and concomitant formation of an intramolecular hydrogen bond. The molecular and electronic
structures of the investigated compounds (HLn) were also studied using quantum chemical calculations.
The calf thymus DNA binding activity of the ligands (HLn) and their Ru(III) complexes were
studied by absorption spectra and viscosity measurements. The mechanism and the catalytic oxidation
of benzyl alcohol by trans-[Ru(Ln)2(AsPh3)2]Cl with hydrogen peroxide as co-oxidant were described.