Ames Laboratory; Chemistry
Chemistry, Ames Laboratory
Journal of the American Chemical Society
The chemical and electronic interaction of organometallic species with metal oxide support materials is of fundamental importance for the development of new classes of catalytic materials. Chemisorption of Cp*(PMe3)IrMe2 on sulfated alumina (SA) and sulfated zirconia (SZ) led to an unexpected redox mechanism for deuteration of the ancillary Cp* ligand. Evidence for this oxidative mechanism was provided by studying the analogous homogeneous reactivity of the organometallic precursors toward trityl cation ([Ph3C]+), a Lewis acid known to effect formal hydride abstraction by one electron oxidation followed by hydrogen abstraction. Organometallic deuterium incorporation was found to be correlated with surface sulfate concentration, as well as the extent of dehydration under thermal activation conditions of sulfated alumina and sulfated zirconia supports. Surface sulfate concentration dependence, in conjunction with a computational study of surface electron affinity, indicates an electron deficient pyrosulfate species as the redox active moiety. These results provide further evidence for the ability of sulfated metal oxides to participate in redox chemistry not only toward organometallic complexes, but also in the larger context of their application as catalysts for the transformation of light alkanes.
Department of Energy Subject Categories
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Iowa State University Digital Repository, Ames IA (United States)