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Lariat ethers with fluoroaryl side-arms: a study of CF center dot center dot center dot metal cation interaction in the complexes of N-(o-fluoroaryl)azacrown ethersстатья
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: 18 июля 2013 г.
- Авторы: Sazonov Petr K., Minacheva Lidiya Kh, Churakov Andrei V., Sergienko Vladimir S., Artamkina Galina A., Oprunenko Yuri F., Beletskaya Irina P.
- Журнал: Dalton Transactions
- Номер: 5
- Год издания: 2009
- Издательство: Royal Society of Chemistry
- Местоположение издательства: United Kingdom
- Первая страница: 843
- Последняя страница: 850
- DOI: 10.1039/b807199c
- Аннотация: New lariat ethers, N-(o-fluorophenyl)aza-15-crown-5 (F-A15C5) and N,N'-bis(o-fluorophenyl) diaza-18-crown-6 (F(2)-A(2)18C6), were prepared by the N-arylation of the corresponding azacrown ethers. The interaction of the ligands with metal cations was studied in solution by (1)H and (19)F NMR (in acetone-d(6)) and UV spectroscopy (MeOH) confirming the formation of complexes of F(2)-A(2)18C6 with K(+), Na(+), Ag(+), Ba(2+), Pb(2+) and of F-A15C5 with Na(+) and giving evidence of CF center dot center dot center dot metal cation interaction. Cation binding constants (beta, evaluated by UV titration method), demonstrate that F-A15C5 and F(2)-A(2) 18C6 form more stable complexes than their fluorine-free analogs. The effect depends on the nature of the metal cation and is at a maximum for hard, singly charged cations ( up to 3 log beta units for K(+) complex of F(2)-A(2)18C6). The X-ray structures of complexes [Pb(F(2)-A(2)18C6)-(H(2)O)](ClO(4))(2) (1) and [Ba(F(2)-A(2)18C6)(ClO(4))(2)] (2) reveal short Pb-F (2.805 angstrom) and Ba-F (2.965 angstrom) contacts. Complex 2 is centrosymmetric (C(i)), while complex 1 has C(2) symmetry with one-side coordination of o-fluorophenyl groups to Pb2+. This "one-side" coordination mode of Pb2+ is indicative of a partial localization of the Pb(2+) lone pair.
- Добавил в систему: Опруненко Юрий Федорович