A Switchable Open/closed Polyaromatic Macrocycle that Shows Reversible Binding of Long Hydrophilic Molecules. (9th August 2017)

• Record Type: Journal Article
• Authors: Kurihara, Kohei; Yazaki, Kohei; Akita, Munetaka; Yoshizawa, Michito
• Is Part Of: Angewandte Chemie. Volume 129:Number 38(2017)
• Page Start: 11518
• Page End: 11522
• Publication Date: 2017-08-09
• Subjects: Acridinium -- Dynamische Bewegungen -- Makrocyclen -- pH-responsive Moleküle -- Wirt-Gast-Komplexe; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201703357
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: 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.