Hydrogen Migration and Vinylidene Pathway for Formation of Methane in the 193 nm Photodissociation of Propene: CH3CHCH2 and CD3CDCD2
| Autor: | Joshua B. Halpern, Askar Fahr, Allan H. Laufer, Yi-Lei Zhao |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry A. 111:8330-8335 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/jp072475j |
| Popis: | Photodissociation channels and the final product yields from the 193 nm photolysis of propene-h6 (CH(2)=CHCH(3)) and propene-d6 (CD(2)=CDCD(3)) have been investigated, employing gas chromatography, mass spectroscopy, and flame ionization (GC/MS/FID) detection methods. The yields of methane as well as butadiene relative to ethane show considerable variations when propene-h6 or propene-d6 are photolyzed. This suggests significant variances in the relative importance of primary photolytic processes and/or secondary radical reactions, occurring subsequent to the photolysis. Theoretical calculations suggest the potential occurrence of an intramolecular dissociation through a mechanism involving vinylidene formation, accompanied by an ethylenic H-migration through the pi-orbitals. This process affects the final yields of methane-h4 versus methane-d4 with respect to other products. The product yields from previous studies of the 193 nm photolysis of methyl vinyl ketone-h6 and -d6 (CH(2)=CHCOCH(3), CD(2)=CDCOCD(3)), alternative precursors for generating methyl and vinyl radicals, are compared with the current results for propene. |
| Databáze: | OpenAIRE |
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