Triptycene-derived calixarenes, heteracalixarenes and analogues

Abstract

Calixarenes, as the third generation of synthetic receptors, are a kind of phenol-derived cyclic oligomers. Featured by their ready preparation, unique structural scaffold and facile modification, they have been extensively studied as molecular platforms and host molecules in different domains of supramolecular chemistry. However, their applications have been limited by the highly flexible conformation. With rigid three-dimensional structures, triptycene derivatives are introduced into conventional calixarenes and heteracalixarenes to synthesize several kinds of novel macrocyclic compounds including triptycene-derived calixarenes, heteracalixarenes, homooxacalixarenes and their analogues by one-pot reactions or two-step methods. The NMR experiments and single-crystal X-ray structures demonstrate that these novel macrocycles have relatively stable conformations and expanded cavities. The electron-rich property of the triptycene moiety adds to the ability of the macrocycles to bind small organic molecules, fullerenes, organic dyes and even linear guests. The triptycene-derived (hetera)calixarenes can also self-assemble into supramolecular structures such as tubular structures, 2D superstructures and 3D microporous architectures due to their symmetric and rigid structures. All these unique properties make them promising candidates as an important kind of host molecules with diverse potential applications in supramolecular chemistry.