Article révisé par les pairs
Résumé : The straightforward synthesis of a Cs symmetrical calix[6]arene possessing carboxylic acid groups as well as an ammonium arm is described. This calixarene can encapsulate ammonium ions through a highly selective recognition process thanks to the presence of an internal ion-paired cap that preorganizes the cavity and constitutes an efficient binding site. © 2008 Elsevier Ltd. All rights reserved.