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The role of radical cations in the radiation chemistry of aldehydes: An ESR study and a quantum chemical analysisстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Belevskii V.N., Tyurin D.A., Chuvylkin N.D.
- Журнал: High Energy Chemistry
- Том: 32
- Номер: 6
- Год издания: 1998
- Издательство: Pleiades Publishing, Ltd
- Местоположение издательства: Road Town, United Kingdom
- Первая страница: 381
- Последняя страница: 391
- Аннотация: The electronic and geometrical structures of the radical cations of ethanal, propanal, butanal, pentanal, and their distonic isomers were calculated using the MNDO-UHF semiempirical method. The results revealed maximum positive charges and spin populations at the oxygen atoms, adjacent carbon atoms, and also at the aldehydic H atoms. The C-H bond corresponding to the aldehydic proton as well as the adjacent C-O and C-C bonds in the radical cations proved to be significantly weakened in comparison with those in neutral molecules. Accordingly, these bonds exhibit maximum tendency to rupture. The rupture of the bond results in acyl radicals (products of deprotonation) and products of alpha- and beta-cleavage (the latter species were identified in the mass spectra of aldehydes). Distonic radical cations are considerably more stable than the corresponding classical isomers. The calculation results are supported by the ESR data for aldehydes irradiated in Freon matrices at 77 K and in a liquid state. Both acyl radicals resulting from deprotonation of the radical cations and the (CH3CHOH)-C-. radical;species resulting from H atom transfer tin the case of ethanal) were detected by ESR. In addition, the products of rearrangement of "normal" radical cations to distonic isomers were observed ((CH3CHCH)-C-.=OH+ and( .)CH(2)CH(2)CH=OH+ for propanal, and (CH2CH2CH2CH)-C-.=OH+ for butanal).
- Добавил в систему: Тюрин Даниил Александрович