Room Temperature Hydrogenation of CO2 Utilizing a Cooperative Phosphorus Pyridone‐Based Iridium Complex

The synthesis, characterization and application of a new complex, [Ir(κ2-P,N-6-DCyPon*)(COD)] (1), where 6-DCyPon* is the anionic species, 6-dicyclohexylphosphino-2-oxo-pyridinide, is reported herein. Complex 1 was found to be an active catalyst in the hydrogenation of CO2 at room temperature. The ligand, 6-DCyPon*, is derived via deprotonation of a novel pro-ligand, 6-DCyPon (6-dicyclohexylphosphino-2-pyridone) during the synthesis of 1. The ligand is shown to participate within the reversible hydrogenation of 1, via a cooperative process, in which the species, [IrH3(κ2-P,N-6-DCyPon)(COD)] (2), was spectroscopically characterized, where 1 reacts with two equivalents of H2.