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A Dynamic Hydrogen‐Bonded Azo‐Macrocycle for Precisely Photo‐Controlled Molecular Encapsulation and Release
Author(s) -
Ye Zecong,
Yang Zhiyao,
Wang Lei,
Chen Lixi,
Cai Yimin,
Deng Pengchi,
Feng Wen,
Li Xiaopeng,
Yuan Lihua
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201906912
Subject(s) - photoisomerization , molecule , chemistry , encapsulation (networking) , photochemistry , stoichiometry , molecular machine , host–guest chemistry , irradiation , isomerization , photochromism , mass spectrometry , controlled release , hydrogen , materials science , nanotechnology , supramolecular chemistry , organic chemistry , catalysis , chromatography , computer network , computer science , physics , nuclear physics
Abstract A light‐responsive system constructed from hydrogen‐bonded azo‐macrocycles demonstrates precisely controlled propensity in molecular encapsulation and release process. A significant decrease in the size of the cavity is observed in the course of the E→Z photoisomerization based on the results from DFT calculations and traveling wave ion mobility mass spectrometry. These macrocyclic hosts exhibit a rare 2:1 host–guest stoichiometry and guest‐dependent slow or fast exchange on the NMR timescale. With the slow host–guest exchange and switchable shape change of the cavity, quantitative release and capture of bipyridinium guests is achieved with the maximum release of 68 %. This work underscores the importance of slow host–guest exchange on realizing accurate release of organic cations in a stepwise manner under light irradiation. The light‐responsive system established here could advance further design of novel photoresponsive molecular switches and mechanically interlocked molecules.