Spectroscopic and electrochemical study for evaluating DNA interaction activity of 4‐(3‐halophenyl)‐6‐(pyridin‐2‐yl)pyrimidin‐2‐amine based piano stool Cp* Rh (III) and Ir (III) complexes

Abstract

Six novel organometallic half sandwich complexes [(η5‐C 5 Me 5 )M(L 1–3 )Cl]Cl.2H 2 O were synthesized using [{(η 5 ‐C 5 Me 5 )M(μ‐Cl)Cl 2 ], where M = Ir (III)/Rh (III) and L 1–3 = three pyridyl pyrimidine based ligands; and characterized by NMR, Infra‐red spectroscopy, conductance, elemental and thermal analysis. The complex‐DNA binding mode and/or strength evaluated using absorption titration, electrochemical studies and hydrodynamic measurement proposed intercalative binding mode, which was also confirmed by molecular docking study. Differential pulse voltammetry and cyclic voltammetry studies indicated an alteration in oxidation and reduction potentials of complexes (M +4 /M +3 ) in presence of CT‐DNA. The metal complexes can cleave plasmid DNA as proposed in gel electrophoretic analysis. The LC 50 values of complexes evaluated on brine shrimp suggested their potent cytotoxic nature.