SYNTHESIS AND CHARACTERIZATION OF 2 AZOBENZENE MODIFIED 1,3-CALIX[4]-BIS-CROWNS AS ARTIFICIAL POTENTIALLY ALLOSTERIC SYSTEMS

Citation
M. Saadioui et al., SYNTHESIS AND CHARACTERIZATION OF 2 AZOBENZENE MODIFIED 1,3-CALIX[4]-BIS-CROWNS AS ARTIFICIAL POTENTIALLY ALLOSTERIC SYSTEMS, Tetrahedron letters, 38(7), 1997, pp. 1187-1190
Citations number
31
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
ISSN journal
00404039
Volume
38
Issue
7
Year of publication
1997
Pages
1187 - 1190
Database
ISI
SICI code
0040-4039(1997)38:7<1187:SACO2A>2.0.ZU;2-A
Abstract
Azo calix[4]crowns1-[2,2'] and 1-[4,4'] have been synthetized consisti ng in unsymmetrical 1,3-calix[4]-bis-crowns combining one polyether cr own-6 and one arobenzene modified crown-6 O-attached at each side of a calix[4]arene in the 1,3-alternate conformation. Preliminary complexa tion of alkalis and ammonium picrates showed the cations to be located in the unmodified crown ether of the 1:1 complexes. Complexation indu ced changes in the trans/cis ratio of the azobenzene unit of 1-[4,4'] by an allosteric mechanism probably due to conformational changes. (C) 1997, Published by Elsevier Science Ltd.