Recent advances in cobalt group metal complexes as anticancer agents: influence of ligands on therapeutic efficacy

Following the groundbreaking discovery of cisplatin as a potent anticancer agent, transition-metal complexes have garnered significant interest for their potential therapeutic applications. Among them, cobalt group metals - cobalt (Co), rhodium (Rh), and iridium (Ir) - have emerged as particularly promising candidates for the development of novel anticancer drugs. Their appeal lies in their ability to adopt multiple oxidation states, exhibit rich coordination chemistry, and undergo redox reactions, all while interacting favorably with biological targets. Notably, the nature of ligands coordinated to the metal center plays a crucial role in modulating the complex's electronic structure and, consequently, its anticancer efficacy. This review presents a comprehensive overview of recent advancements over the past decade, with particular emphasis on the structural diversity of cobalt group complexes arising from varied ligand environments and their corresponding therapeutic potential against a range of cancer types.