Collect. Czech. Chem. Commun.
2001, 66, 641-662
https://doi.org/10.1135/cccc20010641
New Calix[4]arene-Based Amides - Their Synthesis, Conformation, Complexation
Ivan Stibora,*, Martina Růžičkováa, Rostislav Krátkýb, Michal Vindyša, Jaroslav Havlíčekb, Evguenni Pinkhassika, Pavel Lhotáka, Asiya R. Mustafinac, Yuliya E. Morozovac, Ella Kh. Kazakovac and Valentina P. Gubskayac
a Department of Organic Chemistry, Institute of Chemical Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
b Department of Analytical Chemistry, Institute of Chemical Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
c Department of Organic Chemistry, Kazan State University, 420008 Kazan, Russia
Abstract
New chiral calix[4]arene-based diol-diamides 1a, 1b, tetraamides 2a, 2b and 7 as well as achiral diamide 3 and tetraamides 4-6 were prepared. The conformation of 1 has been studied in solution by NMR and in solid state by X-ray crystallography. The pinched-cone conformation of the calix[4]arene skeleton in 1 was found to be stabilized by a circular array of hydrogen bonds formed by two phenolic O-H and two amidic N-H bonds at lower rim. Whereas no significant complexation of Na+ was observed in solution for diamides 1 and 3, tetraamides 2, 4, 5, and 6 give strong complexes with Na+ as confirmed by NMR titrations of 2 and 4. The influence of anions and the solvents used on complexation ability of 2 towards Na+ is negligible.
Keywords: Complexation; Calix[4]arenes; Calixarenes; Conformation analysis; NMR spectroscopy; X-Ray diffraction; Receptors; Recognition.
References: 76 live references.
