Cationic PCP iridaepoxide and carbene complexes for facile water elimination and activation processes

Abstract

Iridaepoxide dihydride complexes of a PCP ligand bearing benzo[b]thiophene linkers are synthesized through ligand coopertive N₂O and H₂ activations. These neutral complexes also eliminate water at elevated temperatures to form the corresponding PC_carbeneP complexes which results in the formal hydrogenation of N₂O to water. The synthesis of cationic iridaepoxide dihydride complexes are reported herein where the room temperature elimination of water is observed when a donating solvent is used. This supports a previously proposed mechanism for this water elimination where hydrides cis to the epoxide are required. Ir(I) and Ir(III) cationic PC_carbeneP complexes are also synthesized through protonation and through O–H oxidation additions of water and phenol.