DC Field | Value | Language |
---|---|---|
dc.contributor.author | LOVEJOY, ER | ko |
dc.contributor.author | Kim, Sangkyu | ko |
dc.contributor.author | ALVAREZ, RA | ko |
dc.contributor.author | MOORE, CB | ko |
dc.date.accessioned | 2013-02-25T23:11:34Z | - |
dc.date.available | 2013-02-25T23:11:34Z | - |
dc.date.created | 2012-02-06 | - |
dc.date.created | 2012-02-06 | - |
dc.date.issued | 1991-09 | - |
dc.identifier.citation | JOURNAL OF CHEMICAL PHYSICS, v.95, no.6, pp.4081 - 4093 | - |
dc.identifier.issn | 0021-9606 | - |
dc.identifier.uri | http://hdl.handle.net/10203/65940 | - |
dc.description.abstract | Intramolecular carbon atom exchange in highly vibrationally excited ketene was studied by monitoring the carbon monoxide fragments (CO)-C-12 and (CO)-C-13 from the photodissociation of (CH2)-C-12 (CO)-C-13 and (CH2)-C-13 (CO)-C-12. Two experimental techniques were employed. In one set of experiments the IR transient absorptions of (CO)-C-12 and (CO)-C-13 were measured following pulsed excimer excitation of ketene C-13 isotopomers, giving carbon atom exchange yields at 351 and 308 nm in a low pressure gas cell. In the other set of experiments, jet-cooled ketene C-13 isotopomers were excited with tunable near-UV radiation, and the CO products were detected by monitoring their VUV laser-induced fluorescence. Carbon atom exchange yields were measured for energies extending from below the triplet decomposition threshold (CH2CO --> CH2 (X 3B1) + CO(X 1-SIGMA+)) to about 4000 cm-1 above the singlet threshold (CH2CO --> CH2 (a 1A1) + CO(X 1-SIGMA+)). The exchange yields range from 4 to 19%, and the energy dependence of the yield exhibits pronounced structure, with maxima at the triplet and singlet decomposition thresholds. Kinetic measurements of the appearance of the CO products were also performed. The time constant for the appearance of the exchanged CO (e.g., (CO)-C-13 from (CH2)-C-13 (CO)-C-12) is significantly longer than that for the direct CO fragment (e.g., (CO)-C-12 from (CH2)-C-13 (CO)-C-12). All the experimental observations are consistent with a simple reaction mechanism involving ketene isomerization, (CH2)-C-13 (CO)-C-12 reversible (CH2)-C-12 (CO)-C-13, and dissociation, (CH2)-C-13 (CO)-C-12 --> (CH2)-C-13 + (CO)-C-12 and (CH2)-C-12 (CO)-C-13 --> (CH2)-C-12 + (CO)-C-13. The isomerization rate was determined by analyzing the CO kinetics and the carbon atom exchange yields in terms of the simple isomerization mechanism. A fit of the energy dependence of the isomerization rate constant to the results of tunneling-corrected Rice-Ramsberger-Kassel-Marcus (RRKM) calculations gave the threshold (28360 +/- 60 cm-1) for the isomerization process. | - |
dc.language | English | - |
dc.publisher | AMER INST PHYSICS | - |
dc.subject | LASER-INDUCED FLUORESCENCE | - |
dc.subject | ELECTRONIC STATES | - |
dc.subject | RATE CONSTANTS | - |
dc.subject | OXIRENE INTERMEDIATE | - |
dc.subject | PHOTOFRAGMENTATION | - |
dc.subject | REARRANGEMENT | - |
dc.subject | DISSOCIATION | - |
dc.subject | CH2(X3B1) | - |
dc.subject | ABINITIO | - |
dc.subject | CO | - |
dc.title | KINETICS OF INTRAMOLECULAR CARBON-ATOM EXCHANGE IN KETENE | - |
dc.type | Article | - |
dc.identifier.wosid | A1991GF09900024 | - |
dc.identifier.scopusid | 2-s2.0-0000787985 | - |
dc.type.rims | ART | - |
dc.citation.volume | 95 | - |
dc.citation.issue | 6 | - |
dc.citation.beginningpage | 4081 | - |
dc.citation.endingpage | 4093 | - |
dc.citation.publicationname | JOURNAL OF CHEMICAL PHYSICS | - |
dc.identifier.doi | 10.1063/1.460764 | - |
dc.contributor.localauthor | Kim, Sangkyu | - |
dc.contributor.nonIdAuthor | LOVEJOY, ER | - |
dc.contributor.nonIdAuthor | ALVAREZ, RA | - |
dc.contributor.nonIdAuthor | MOORE, CB | - |
dc.type.journalArticle | Article | - |
dc.subject.keywordPlus | LASER-INDUCED FLUORESCENCE | - |
dc.subject.keywordPlus | ELECTRONIC STATES | - |
dc.subject.keywordPlus | RATE CONSTANTS | - |
dc.subject.keywordPlus | OXIRENE INTERMEDIATE | - |
dc.subject.keywordPlus | PHOTOFRAGMENTATION | - |
dc.subject.keywordPlus | REARRANGEMENT | - |
dc.subject.keywordPlus | DISSOCIATION | - |
dc.subject.keywordPlus | CH2(X3B1) | - |
dc.subject.keywordPlus | ABINITIO | - |
dc.subject.keywordPlus | CO | - |
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