Reversible CO2 Fixation by Iridium(I) Complexes Containing Me2PhP as Ligand

The iridium(I) complexes [IrCl(Me2PhP)3] (1), [Ir(Me2PhP)4]Cl (2), [Ir(Me2PhP)4]I (3), and [Ir(Me2PhP)4]PF6 (4) are prepared from the iridium(I) precursors [IrX(coe)2]2 (X = Cl, I). Complex 1 reacts reversibly with CO2 to form the metallacyclic compound [IrCl(C2O4-k2C,O)(Me 2PhP)3] (5), which was characterized by NMR and IR measurements as well as elemental analysis. Additionally, [mer-Ir(Cl) 2(H)(Me2PhP)3] (6) and [mer-Ir(CO 3)(H)(Me2PhP)3] (7) are formed as side products from water present in the used CO2 and the solvents. Compound 2 yields similar results. When the iodo compound 3 is used, the cationic compound [Ir(I)(H)(Me2PhP)4]+I- (9) is formed as one of the products. Molecular structures of 1, 2, 5, and 9 are presented. © 2010 American Chemical Society.This work was funded by MEC (Grants CTQ2006-01629 and CONSOLIDER INGENIO- 2010 CSD2006-0015) and the Deutsche Forschungsgemeinschaft (DFG) with grants to J.L. (LA 2474/1-1 and LA 2474/1-2).Peer Reviewe