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.