Highly stable Cp*-Ir(III) complexes with N-heterocyclic carbene ligands as C-H activation catalysts for the deuteration of organic molecules.

The preparation of a series of complexes of the type CpIrX2(NHC) provides effective catalysts for the H/D exchange of a wide range of organic molecules in methanol-d4. The reaction proceeds with higher yields under milder reaction conditions than previous CpIr systems reported thus far. For comparative purposes, we also studied the catalytic activity of CpIrCl2(PMe3) under the same reaction conditions. The molecular structures of two of the new CpIr(NHC) complexes are described.