Secondary Coordination Sphere Interactions Facilitate the Insertion Step in an Iridium(III) CO₂ Reduction Catalyst

There is considerable interest in both catalysts for CO2 conversion and understanding how CO2 reacts with transition metal complexes. Here we develop a simple model for predicting the thermodynamic favorability of CO2 insertion into Ir(III) hydrides. In general this reaction is unfavorable; however, we demonstrate that with a hydrogen bond donor in the secondary coordination sphere it is possible to isolate a formate product from this reaction. Furthermore, our CO2 inserted product is one of the most active water-soluble catalysts reported to date for CO2 hydrogenation.