Selective photooxidation of small alkenes by O[sub 2] with red light in zeolite Y
- Lawrence Berkeley Lab., CA (United States)
Upon loading number of UV photons per unit a and O[sub 2] into zeolite NaY, photochemistry was observed at wavelengths as long as 760 nm. Similarly, photoexcitation of trans- or cis-2-butene and O[sub 2] in this zeolite resulted in chemical reaction at a threshold wavelength of 600 nm. Reactions were initiated either with filtered tungsten-source light or the emission of a CW dye laser and typically conducted at -50[degree]C. Products identified by FT-infrared spectroscopy were 2,3-dimethyl-3-hydroperoxy-l-butene (>90%) and acetone in the case of DMB + O[sub 2]. trans- or cis-2-butene + O[sub 2] gave exclusively 3-hydroperoxy-1-butene. This constitutes the first synthesis of this hydroperoxide by direct photolysis of 2-butene-O[sub 2] pairs. Laser reaction excitation spectra in the 500-700-nm region revealed a continuous absorption for both the DMB[center dot]O[sub 2] and the 2-butene-O[sub 2] systems. It is attributed to a charge-transfer transition. Comparison with corresponding absorption spectra in conventional media shows that the excited alkene-O[sub 2] charge-transfer states are stabilized by electrostatic interactions with the zeolite NaY environment by 12 000cm[sup [minus]1]. Substantially less stabilization was observed in high-silica faujasite. 50 refs., 10 figs., 2 tabs.
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 7069289
- Journal Information:
- Journal of the American Chemical Society; (United States), Vol. 116:5; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALKENES
OXIDATION
PHOTOLYSIS
ACETONE
BUTENES
DYE LASERS
EXPERIMENTAL DATA
FAUJASITE
INFRARED SPECTRA
OXYGEN
PHOTOCHEMISTRY
ZEOLITES
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
ELEMENTS
HYDROCARBONS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
KETONES
LASERS
LIQUID LASERS
MATERIALS
MINERALS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
SILICATE MINERALS
SPECTRA
400500* - Photochemistry
400102 - Chemical & Spectral Procedures