| Autor: |
Frank M. Harris, I.W. Griffiths, John H. Beynon, E.S. Mukhtar |
| Rok vydání: |
1982 |
| Předmět: |
|
| Zdroj: |
International Journal of Mass Spectrometry and Ion Physics. 43:283-292 |
| ISSN: |
0020-7381 |
| Popis: |
The average internal energies of photoexcited ions have been varied by changing the temperature of the source in which the ions are formed and photoexciting them through constant photoexcitation energies in the field-free region of a double-focusing mass spectrometer. It is shown that the relative rates of competing dissociation reactions of photoexcited n -butylbenzene and n -pentylbenzene molecular ions are highly sensitive to source temperature. By comparing the results with those obtained by varying the photoexcitation energy at a fixed source temperature it is deduced that the increase in the average internal energy of ions entering the field-free region (i.e. prior to photoexcitation) is about 0.27 eV for a 100dgC increase in source temperature. The magnitude of the chance is confirmed in an entirely different type of experiment in which the translational energies released for various dissociation reactions of photoexcited molecular ions of t -butylbenzene. nitrobenzene and n -propylbenzene are measured as a function of source temperature. Calculations using known thermodynamic data show that the effects observed are related to the change in the average internal energy of the sample molecules with source temperature. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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