title: Single-Site Zeolite-Anchored Organoiridium Carbonyl Complexes: Characterization of Structure and Reactivity by Spectroscopy and Computational Chemistry.
abstract: A family of HY zeolite-supported cationic organoiridium carbonyl complexes was formed by reaction of Ir(CO)2 (acac) (acac=acetylacetonate) to form supported Ir(CO)2 complexes, which were treated at 298 K and 1 atm with flowing gas-phase reactants, including C2 H4 , H2 , (12) CO, (13) CO, and D2 O. Mass spectrometry was used to identify effluent gases, and infrared and X-ray absorption spectroscopies were used to characterize the supported species, with the results bolstered by DFT calculations. Because the support is crystalline and presents a nearly uniform array of bonding sites for the iridium species, these were characterized by a high degree of uniformity, which allowed a precise determination of the species involved in the replacement, for example, of one CO ligand of each Ir(CO)2 complex with ethylene. The supported species include the following: Ir(CO)2 , Ir(CO)(C2 H4)2 , Ir(CO)(C2 H4), Ir(CO)(C2 H5), and (tentatively) Ir(CO)(H). The data determine a reaction network involving all of these species.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Davis, One Shields Avenue, Davis, California, 95616 (USA).
authors.forename: Claudia
authors.initials: C
authors.lastname: Martinez-Macias
authors.affiliation: Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama, 35487 (USA).|National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831 (USA).
authors.forename: Mingyang
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama, 35487 (USA).
authors.forename: David A
authors.initials: DA
authors.lastname: Dixon
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Davis, One Shields Avenue, Davis, California, 95616 (USA). bcgates@ucdavis.edu.
authors.forename: Bruce C
authors.initials: BC
authors.lastname: Gates
keywords: CO probe molecule; DFT calculations; iridium carbonyls; iridium hydride; zeolites