Diffuse reflectance spectroscopy of visible alkene-O[sub 2] charge-transfer absorptions in zeolite Y and determination of photooxygenation quantum efficiencies

Journal Article · Thu Dec 15 04:00:00 EST 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100101a046· OSTI ID:6878994

Blatter, F; Moreau, F; Frei, H ^[1]

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1. Lawrence Berkeley Lab., CA (United States)

Very large red shifts of charge transfer bands of 2,3-dimethyl-2-butene-O[sub 2], 2-methyl-2-butene-O[sub 2], and trans-2-butene-O[sub 2] complexes in zeolite NaY have been observed by diffuse reflectance spectroscopy. Absorption tails are shifted by over 10 000 cm[sup [minus]1] compared to gas phase, solution or solid oxygen matrix. In zeolite BaY with its divalent counterions, the 2-butene-O[sub 2] absorption is further red shifted by several thousand wavenumbers. This points to stabilization of the excited charge-transfer states by the very strong electrostatic fields inside the zeolite cages as the origin of the observed red shifts. Reaction quantum efficiencies of previously reported selective photooxygenations of these alkenes by visible light are estimated on the basis of these spectra and found to be in the range 0.1-0.3. 26 refs., 4 figs.

• OSTI ID: 6878994
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:50; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201* -- Chemical & Physicochemical Properties
400500 -- Photochemistry
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
ALKENES
CHARGE TRANSPORT
CHEMICAL REACTIONS
COMPLEXES
ELEMENTS
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MATHEMATICAL MODELS
MINERALS
NONMETALS
ORGANIC COMPOUNDS
OXIDATION
OXYGEN
PHOTOCHEMICAL REACTIONS
SILICATE MINERALS
SPECTROSCOPY
ZEOLITES