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

There is considerable interest in both catalysts for CO(2) conversion and understanding how CO(2) reacts with transition metal complexes. Here we develop a simple model for predicting the thermodynamic favorability of CO(2) 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 CO(2) inserted product is one of the most active water-soluble catalysts reported to date for CO(2) hydrogenation.