New opportunities in synthetic macrocyclic arenes.

Synthetic macrocyclic receptors generally display unique geometries, preorganized cavities, and tunable binding affinities, which facilitate their application in numerous fields including molecular recognition and self-assembly. Calix[n]arenes and pillar[n]arenes are very prevalent synthetic macrocyclic arenes, whose syntheses, host-guest properties, and supramolecular functions have been intensively studied. In recent years, some new families of synthetic macrocyclic arenes closely related to calix[n]arenes and pillar[n]arenes have emerged and represent new opportunities in modern supramolecular chemistry. Therefore, in this feature article, we present a comprehensive discussion on some newly designed, versatile macrocyclic arene receptors that sprang up during the past decade, focusing on their syntheses, structures, functionalization, and host-guest properties. Future perspectives of synthetic macrocyclic arene chemistry are also given. We hope that this feature article will be a timely and useful reference for those who are exploring new opportunities in functional macrocycles.