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A Switchable Open/closed Polyaromatic Macrocycle that Shows Reversible Binding of Long Hydrophilic Molecules
Author(s) -
Kurihara Kohei,
Yazaki Kohei,
Akita Munetaka,
Yoshizawa Michito
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201703357
Subject(s) - chemistry , molecule , base (topology) , small molecule , crystallography , organic chemistry , mathematical analysis , biochemistry , mathematics
In spite of wide‐ranging previous studies on synthetic macrocycles, the installation of open–close functions into the frameworks remains a challenge. We present a new polyaromatic macrocycle capable of switching between open and closed forms in response to external stimuli, namely, base and acid. The macrocycle, which is prepared in three steps, has a well‐defined hydrophobic cavity with a length of around 1 nm, surrounded by four pH‐responsive acridinium panels. The open and closed structures were confirmed by single‐crystal X‐ray analysis. The cylindrical cavity can bind long hydrophilic molecules up to 2.7 nm in length in neutral water and then release the bound guests through a reversible open‐to‐closed structural change upon simple addition of base.