A comprehensive survey of Mn(i) carbonyls as CO-releasing molecules reported over the last two decades

Abstract

Over the last two decades, manganese(I) carbonyl complexes have been widely investigated as carbon monoxide releasing molecules (CORMs) to transfer small quantities of CO to biological targets to have beneficial impacts such as preventing ischemia reperfusion injury and reducing organ transplant rejection. Furthermore, these complexes exhibit beneficial anti-coagulative, anti-apoptotic, anti-inflammatory, and anti-proliferative properties. Owing to their highly controlled substitution chemistry and oxidative durability, Mn(I) carbonyl moieties were combined with a wide range of auxiliary ligands, including biomolecules. This review focused on tri- and tetracarbonyl Mn(I) complexes that were exposed to light, changed the redox status, or underwent thermal activation to release carbon monoxide. Kinetic parameters, stability in the dark, number of CO release equivalents, CO detection tools, and the nature of solvents used in the studies are reported and tabulated. An overview of all the previously published Mn(I) CORMs is specifically provided to define the method of action of these promising biologically active compounds and discuss their possible therapeutic applications in relation to their CO-releasing and biocompatibility characteristics.