Rhodium and Iridium Complexes with α-Diketimine Ligands: Oxidative Addition of H2 and O2

The treatment of [M(mu-Cl)(coe)(2)](2) (M = Rh, Ir; coe = cyclooctene) with the alpha-diketimines ArN=C(Me)C(Me)=NAr (Ar = Ph, Xy; Xy = 2,6-Me2C6H3) in thf, followed by the addition of CNtBu, gave the alpha-diketimine complexes [M(Cl){ArN=C(Me)C(Me)=NAr} (CNtBu)] (1: M = Rh, Ar = Ph; 2: M = Rh, Ar = Xy; 3: M = Ir, Ar = Xy). The reaction of 3 with dihydrogen resulted in the formation of the iridium dihydrido complex [Ir(Cl)(H)(2){XyN=C(Me)C(Me)=NXy}(CNtBu)] (4). The complexes 2 and 3 reacted with O-2 or O-18(2) to yield the peroxido complexes [M(Cl)(O-2){XyN=C(Me)C(Me)=NXy}(CNtBu)] (5a: M = Rh; 6a: M = Ir) and [M(Cl)(O-18(2)){XyN=C(Me)C(Me)=NXy}(CNtBu)] (5b: M = Rh; 6b: M = Ir), respectively. All of the complexes were characterized by NMR and IR spectroscopy. In addition, complexes 3 and 5a were characterized by X-ray crystallography.