| Autor: |
Dixon-Warren, St. J., Leggett, K., Matyjaszczyk, M. S., Polanyi, J. C., Young, P. A. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 9/1/1990, Vol. 93 Issue 5, p3659, 14p, 12 Graphs |
| Abstrakt: |
The surface-aligned photoreaction (PRXN) of OCS physisorbed on LiF(001) was investigated at 222 nm. Ultraviolet PRXN within the adsorbate was detected over a wide range of coverages. Diatomic sulphur was produced by reaction of photolytically generated sulphur atoms with a coadsorbed OCS molecule: S*, S+OCS(ad)→S*2, S2(g)+CO(ad/g). Translational energy and angular distributions of the S2 reaction product were obtained by angle-resolved time-of-flight mass spectrometry. The dynamics of PRXN were found to vary with adsorbate coverage. At low coverages (<10-2 ML), reaction was attributed to a ‘‘direct’’ abstraction mechanism, leading to energetic S2. As the coverage was increased above 10-2 ML, both ‘‘direct’’ and ‘‘indirect’’ PRXN dynamics were observed. Possible origins of these differing photoreaction dynamics are discussed. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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