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Specific features of the crystal packing that enable styryl dyes of the pyridine series to undergo the solid-phase [2+2] photocycloaddition including the process with single crystal retentionстатья
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Kuz'mina L.G., Vedernikov A.I., Sazonov S.K., Lobova N.A., Loginov P.S., Howard J.A.K, Alfimov M.V., Gromov S.P.
- Журнал: Crystallography Reports
- Том: 53
- Номер: 3
- Год издания: 2008
- Издательство: Maik Nauka/Interperiodica Publishing
- Местоположение издательства: Russian Federation
- Первая страница: 428
- Последняя страница: 450
- DOI: 10.1134/S1063774508030103
- Аннотация: The crystal packing of a number of styryl dyes of the pyridine series is analyzed. The structures of three dyes and three [2 + 2] photocycloaddition (PCA) products, 1,2,3,4-tetrasubstituted cyclobutanes, obtained in single crystals are determined by X-ray diffraction. Stacks of planar organic cations are characteristic of styryl dye packings. The proceeding of the PCA reaction as a single crystal-to-sing e crystal transformation in the syn head-to-head stacks is in principle impossible. The syn head-to-tail stacking packings are favorable for the PCA reactions resulting in the centrosymmetric rtct isomers of cyclobutane. The stacking packings, in which molecules are related by the twofold axes (the anti arrangement of molecules), are also favorable for PCA in single crystals. In this case, the products are the rtct isomers of cyclobutane. The presence of the I- counterions in a packing is a factor impeding the PCA reaction, because the secondary I center dot center dot center dot H-C bonds increase the rigidity of the crystal lattice. The conditions necessary for proceeding the PCA reactions in styryl dyes as single crystal-to-single crystal processes are as follows: (1) the stacks split into pairs of organic cations (dimers) with the d distances within 4.2 angstrom in a dimer and d exceeding 4.2 angstrom between the dimers; and (2) the dimers are surrounded by flexible shells consisting of anions, solvate molecules, or flexible moieties of the organic cations themselves.
- Добавил в систему: Громов Сергей Пантелеймонович