Ruthenium, rhodium, and iridium complexes featuring fluorenyl benzohydrazone derivatives: Synthesis and preliminary investigation of their anticancer and antibacterial activity

Abstract

A convenient synthesis of twelve complexes (1–12) of ruthenium(II), rhodium(III) and iridium(III) containing fluorenyl benzohydrazone ligands having the general formula [(arene)M(L)Cl] (arene: benzene/p-cymene/Cp*; l-bidentate substituted benzoyl hydrazone derivatives) has been carried out. The characterization of the complexes has been done by FT-IR, UV–Vis, NMR and X-ray crystallographic studies. The metal complexes exhibit N∩O binding mode through the azomethine nitrogen and the imidolate oxygen forming a five-membered chelating ring. All the compounds were tested for their antibacterial properties against three strains of bacterial microorganisms - Staphylococcus aureus (+ve), Klebsiella pneumoniae (-ve) and Escherichia coli (-ve). In-vitro assay results further revealed that complexes 4 and 6 significantly act against Gram-positive (Staphylococcus aureus) and Gram-negative (E. coli and Klebsiella pneumoniae). An in-vitro assessment of the cytotoxic effects of both the complexes and ligands was performed, and the findings indicate that complex 9 exhibited the most promising results with the lowest IC50 value in terms of cell viability percentage against HeLa cell lines. These results highlight the potential of further investigating the anticancer properties of this particular complex.