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Three-membered ring or open chain molecule - (F3C)F 2SiONMe2 a model for the α-effect in silicon chemistryстатья
Статья опубликована в высокорейтинговом журнале
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: 14 февраля 2019 г.
- Авторы: Mitzel N.W., Vojinović K., Fröhlich R., Foerster T., Robertson H.E., Borisenko K.B., Rankin D.W.H
- Журнал: Journal of the American Chemical Society
- Том: 127
- Номер: 39
- Год издания: 2005
- Издательство: American Chemical Society
- Местоположение издательства: United States
- Первая страница: 13705
- Последняя страница: 13713
- DOI: 10.1021/ja052865o
- Аннотация: (F3C)F2SiONMe2 was prepared from LiONMe2 and F3CSiF3. It was characterized by gas IR and multinuclear solution NMR spectroscopy and by mass spectrometry. Its structure was elucidated by single crystal X-ray crystallography and by gas electron diffraction. (It exists as a conformer mixture.) Important findings were extremely acute SiON angles [solid 74.1(1)°, gas anti 84.4(32)° and gauche 87.8(20)°] and short Si⋯N distances [solid 1.904(2) Å]. The bending potential of the SiON unit was calculated at the MP2/6-311++G(3df,2dp) level of theory and appears very flat and highly asymmetric. The calculated atomic charges (NPA) are counterintuitive to the expected behavior for a classical Si-N dative bond, as upon formation of the Si⋯N bond electron density is transferred mainly from oxygen to nitrogen, while the silicon charge is almost unaffected. Despite the molecular topology of a three-membered ring, the topology of the electron density shows neither a bond critical point between Si and N atoms nor a ring critical point, but the electron density and Laplacian values are related to other hypercoordinate Si compounds. The electronic properties of (F3C)F2SiONMe 2 were compared to those of the adduct (F3C)F 2(MeO)Si-NMe3, whose properties and structure were also calculated. The charge distribution and Laplacian values along the Si-N vectors in both molecules are similar but not equivalent. (F3C)F 2SiONMe2 contains thus a nonclassical Si⋯N bond, and its properties can be regarded as a new model for the explanation of the old postulate of an α-effect in silicon chemistry, explaining the behavior of compounds with geminal Si and N atoms. © 2005 American Chemical Society.
- Добавил в систему: Borisenko Konstantin B.