Acid-responsive organogel mediated by arene–perfluoroarene and hydrogen bonding interactions

Abstract

A phenyl and a 2,3,5,6-tetrafluorophenyl ring, each bearing a tris(n-dodecyloxy)benzylamine moiety via an amide bond, were tethered together through an imine linkage to give a non-covalent synthon (imine 1) with a strong capacity of supramolecular self-assembly. Gelation was observed in several organic solutions, within which fibrous aggregate morphologies were visualized by SEM and AFM. Both arene–perfluoroarene stacking and amide–amide hydrogen bonding interactions were responsible for such self-assembly behaviours, as evidenced by 1H NMR studies. Hydrolysis of the imine linkage catalyzed by acid strongly weakened the intermolecular interactions, resulting in dissociation of the low molecular weight gelator and giving rise to an acid-mediated gel–sol transition.