Azobenzene‐Based Macrocyclic Arenes: Synthesis, Crystal Structures, and Light‐Controlled Molecular Encapsulation and Release
Yuezhou Liu, Hongliang Wang, Peiren Liu, Huangtianzhi Zhu, Bingbing Shi, Xin Hong, Feihe Huang
Abstract
Abstract Azobenzene (azo)‐based macrocycles are highly fascinating in supramolecular chemistry because of their light‐responsiveness. In this work, a series of azo‐based macrocyclic arenes 1 , 2 , 3 , and 4 , distinguished by the substituted positions of azo groups, is rationally designed and synthesized via a fragment‐cyclization method. From the crystal and computed structures of 1 , 2 , and 3 , we observe that the cavity size of these azo‐macrocycles decreases gradually upon E → Z photoisomerization. Moreover, light‐controlled host–guest complexations between azo‐macrocycle 1 and guest molecules (7,7,8,8‐tetracyanoquinodimethane, terephthalonitrile) are successfully achieved. This work provides a simple and effective method to prepare azo‐macrocycles, and the light‐responsive molecular‐encapsulation systems in this work may further advance the design and applications of novel photo‐responsive host–guest systems.