A 193-nm-laser photofragmentation time-of-flight mass spectrometric study of dimethylsulfoxide
| Autor: | D. P. Heck, W. S. Jenks, Y.-S. Cheung, Cheuk-Yiu Ng, T. Tetzlaff, H.-Q. Zhao |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | The Journal of Chemical Physics. 106:86-93 |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/1.473025 |
| Popis: | The photodissociation of dimethylsulfoxide [(CH3)2SO] at 193.3 nm has been investigated using the molecular beam time-of-flight (TOF) mass spectrometric technique. In addition to CH3 and SO, CH3SO is also observed as a stable primary product, indicating that CH3SO+CH3 is an important product channel for the 193.3 nm photodissociation of (CH3)2SO. The analysis of the TOF data provides evidence that SO is formed via a stepwise mechanism: (CH3)2SO+hν (193.3 nm)→CH3SO+CH3→2CH3+SO. The analysis also indicates that ≈53% of the primary CH3SO radicals undergo further dissociation to produce CH3+SO, yielding a quantum yield of ≈1.53 for CH3. Within the sensitivity of our experiment, the product channel of CH3SCH3+O is not found. The angular distribution for the formation of CH3SO+CH3 is found to be isotropic, an observation consistent with a predissociation mechanism, in which the dissociation of photoexcited (CH3)2SO is slow compared to its rotational period. The energetics for selected dissociation reactions of ... |
| Databáze: | OpenAIRE |
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