Synthesis, characterization, anticancer properties and theoretical study of asymmetrical Cd(II)[sbnd]N2-Schiff base complexes

Abstract

In this study, synthesis, characterization and anticancer properties of four cadmium(II) complexes of a new asymmetrical bidentate Schiff base ligand (abbreviated as L) with a CdLX2 (X = Cl−, Br−, I− and SCN−) general formula are reported. The ligand and its complexes were characterized by elemental analysis, molar conductance, UV–Vis, FT-IR, 1H NMR and 13C NMR spectra. Coordination of the ligand was confirmed by consistent changes in FT-IR and NMR spectra when compared with the spectra of free ligand. Redox properties of ligand and complexes were investigated by the electrochemical method, cyclic voltammetry. Also, changes in the cathodic and anodic peaks potentials of complexes regarding free ligand, confirm synthesis of complexes. All complexes correspond to Cd(II)/Cd(0) system show one pair anodic and cathodic peaks. The density function theory calculations are used to investigate the electronic structures of the ligand and its complexes. In vitro anticancer activity of ligand and complexes was studied on cancer cells lines HT29 and A549. Obtained data confirmed the potent cytotoxic activity in the chloro and bromo substituted Cd(II) complexes when compared with free ligand, control sample and other Cd(II) compounds. The IC50 values for ligand and complexes were approximately less than 0.1 mg mL−1.