Abstract We herein report on the application and structural investigation of a new set of complexes that contain bidentate N-heterocyclic carbenes (NHCs) and primary amine moieties of the type [M (arene) Cl (L)][M= Ru, Ir, or Rh; arene= p-cymene or pentamethylcyclopentadienyl; L= 1-(2-aminophenyl)-3-(n-alkyl) imidazol-2-ylidine]. These complexes were tested and compared in the hydrogenation of acetophenone with ...