Article révisé par les pairs
Résumé : This study explores the impact of a small structural modification on a biomimetic receptor. Thehosting structure is a calix[6]arene capped by a tetraaza core. Two receptors are compared: one (1)presents three anisole units while the other (2) has three phenols. The latter was obtained with anexcellent yield by selective demethylation thanks to a supramolecular strategy. Complexationstudies showed that [2.H]+ displays strong affinities for Cl−, NO3−, HSO4−, whereas [1.H]+ is nonresponsive.The anions are embedded at the level of the small rim, hydrogen-bonded to theprotonated cap and the phenol groups. Ternary complexes are obtained in the presence ofammoniums. Finally, [2.H]+ shows high affinity for small zwitterions presenting a carboxylateand an ammonium groups separated by one or two carbon atom(s), not three, due to multipointrecognition. These results open routes to the design of new receptors for a variety of anionicand zwitterionic guests.