Rhodium(III) and iridium(III) complexes as anticancer agents

► Rhodium(III) and iridium(III) complexes with polypyridyl ligands are effective cytotoxic agents. ► Selectivity for malignant cells can be improved by employing substituted phenanthroline ligands. ► Cellular impact of half-sandwich complexes depends on the donor properties of their facial coligands. ► Apoptosis induction and associated high levels of reactive oxygen species. ► Dose-dependent inhibition of mitochondrial respiration.