Homolytic Se−H Bond Energy and Ionization Energy of Benzeneselenol and the Acidity of the Corresponding Radical Cation
| Autor: | Hilkka I. Kenttämaa, Ruomei Li, Leonard J. Chyall, Diane T. Leeck |
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| Rok vydání: | 1996 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry. 100:6608-6611 |
| ISSN: | 1541-5740 0022-3654 |
| Popis: | The homolytic Se−H bond energy of benzeneselenol, a very efficient radical trap in solution and in the gas phase, was determined experimentally by using two independent approaches in a Fourier-transform ion cyclotron resonance mass spectrometer. The hydrogen−selenium bond strength was concluded to be 76−80 kcal mol-1 based on the measurement of the efficiency of hydrogen atom abstraction from benzeneselenol by several radical cations. The Se−H bond energy was also determined indirectly through the use of a thermochemical cycle. This approach required the measurement of the adiabatic ionization energy of benzeneselenol and the proton affinity of C6H5Se•. An adiabatic ionization energy of 8.3 ± 0.1 eV was obtained by measurement of the efficiencies of various electron transfer reactions in the forward and reverse directions. The proton affinity of C6H5Se• (acidity of the benzeneselenol radical cation) was found to be 200 ± 3 kcal mol-1 based on the measured efficiencies of several proton transfer reactions.... |
| Databáze: | OpenAIRE |
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