Photochemical activation of C-H bonds on a rhodium catalyst. Observation of a competitive effect on the surface

Journal Article · Wed Mar 09 04:00:00 EST 1994 · Journal of the American Chemical Society; (United States)

DOI:https://doi.org/10.1021/ja00084a002· OSTI ID:7069293

Wong, J C.S.; Yates, Jr, J T ^[1]

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1. Univ. of Pittsburgh, PA (United States)

The UV (325 nm) photolysis of the Rh[sup 1](CO)[sub 2] species on an Al[sub 2]O[sub 3] support produces an active surface intermediate, Rh[sup 1](CO), which reacts with the C-H bond of cyclohexane by oxidative addition to form a postulated surface species, Rh(CO)(H)(C[sub 6]H[sub 11]). This species degrades to form a stable C[sub 6]H[sub 11] species on the surface. Unexpectedly, the normalized yield of surface C[sub 6]H[sub 11] species was found to be higher for lower Rh loadings using the same number of UV photons per unit area. This could be qualitatively explained by the fact that the formation of a dimer surface species, Rh[sub 2](CO)[sub 3] (a competitive reaction for the intermediate, Rh[sup 1](CO)[sub 7] responsible for C-H bond activation), is favored for high surface concentrations of Rh[sup 1](CO)[sub 2]. It is shown that the dimer formation competes with the desired C-H bond activation process. 41 refs., 9 figs., 1 tab.

• OSTI ID: 7069293
• Journal Information: Journal of the American Chemical Society; (United States), Journal Name: Journal of the American Chemical Society; (United States) Vol. 116:5; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400500* -- Photochemistry
ALKANES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BOSONS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYSTS
CHALCOGENIDES
CHEMICAL ACTIVATION
CHEMICAL BONDS
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
CYCLOALKANES
CYCLOHEXANE
DECOMPOSITION
DIMERS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
HYDROCARBONS
INFRARED SPECTRA
MASSLESS PARTICLES
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOLYSIS
PHOTONS
RADIATIONS
RHODIUM COMPLEXES
SPECTRA
TRANSITION ELEMENT COMPLEXES
ULTRAVIOLET RADIATION