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Synthesis, structure, and ion selective complexation of trans and cis isomers of photochromic dithia-18-crown-6 ethersстатья
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: Alfimov M.V., Gromov S.P., Fedorov Y.V., Fedorova O.A., Vedernikov A.I., Churakov A.V., Kuz'mina L.G., Howard J.A.K, Bossmann S., Braun A., Woerner M., Sears D.F., Saltiel J.
- Журнал: Journal of the American Chemical Society
- Том: 121
- Номер: 21
- Год издания: 1999
- Издательство: American Chemical Society
- Местоположение издательства: United States
- Первая страница: 4992
- Последняя страница: 5000
- DOI: 10.1021/ja990370r
- Аннотация: Photochromic styryl dyes containing benzodithia-18-crown-6 and N-substituted benzothiazolium moieties are synthesized and characterized spectroscopically and, for a specific case, by X-ray crystallography. The effects of the N-substituent and of sulfur atom substitution in the crown ether cavity on metal cation complex formation and on photochromism due to reversible trans-cis photoisomerization are evaluated. High selectivities for heavy metal ions, such as Ag+ and Hg2+, are observed, in contrast to the benzo-18-crown-6 dyes which selectively bind alkali and alkali earth cations. Relative complex formation stability constants, determined spectrophotometrically, are converted to absolute values by polarographic measurements. The stability constant for Hg2+ complex formation by the trans dye is enhanced 47-fold upon substitution of the 4-butylsulfonate group for methyl at the nitrogen of the benzothiazolium moiety. Photoisomerization to the cis dye is accompanied by a further 11-fold stability constant increase and by spectral changes that are consistent with formation of an ion-"capped" complex, involving intramolecular coordination of the sulfonate anion to Hg2+. Addition of a large excess of Mg2+ ions disrupts this intramolecular coordination bond without displacing the Hg2+ ion from the dithiacrown ether cavity.
- Добавил в систему: Громов Сергей Пантелеймонович