Antiproliferative activity and electrochemical oxygen evolution by Ni(ii) complexes ofN′-(aroyl)-hydrazine carbodithioates

Abstract

The electrochemical water splitting by transition metal complexes is emerging very rapidly. The nickel complexes also play a very vital role in various biological activities. Here, three new ligands {H2mbhce =N′-(4-methyl-benzoyl), H2pchce =N′-(pyridine-carbonyl) and H2hbhce =N′-(2-hydroxy-benzoyl) hydrazine carbodithioic acid ethyl ester} and their corresponding Ni(ii) complexes [Ni(Hmbhce)2(py)2] (1), [Ni(pchce)(o-phen)2]·CH3OH·H2O (2) and [Ni(hbhce)(o-phen)2]·1.75CHCl3·H2O (3) have been synthesized and fully characterized by various physicochemical and X-ray crystallography techniques. The photoluminescence study and thermal degradations were also examined. The treatment of K562 cells with the increasing concentrations of the nickel salts, ligands, and complexes1,2, and3showed dose-dependent cytotoxicity. The cytotoxic activity of ligands reveals that ligand H2mbhce is more potent in inhibiting the growth of tumor cells in comparison to other ligands H2pbhce and H2hbhce. Cytotoxicity assay results indicate that all complexes have remarkable cytotoxic potential in comparison to either nickel salts or the free ligands. Among these complexes, complex1has significantly better anti-tumor activity as compared to complexes2and3. The electrochemical study of complexes1,2, and3for water oxidation reveals that all the complexes possess admirable electrocatalytic activity towards oxygen evolution reaction (OER) and have lower overpotential (328, 338, and 370 mV, respectively) than many previously reported complexes and RuO2(390 mV). Among complexes1,2, and3, complex-2shows a better water oxidation response. Consequently, these complexes have great potential to be utilized in fuel cells. The more reliable electrochemical parameter TOF is also calculated for all three complexes. © The Royal Society of Chemistry 2021.