An atropisomeric M2L4 cage mixture displaying guest-induced convergence and strong guest emission in water. Issue 31 (24th July 2020)

• Record Type: Journal Article
• Authors: Tsutsui, Takahiro; Catti, Lorenzo; Yoza, Kenji; Yoshizawa, Michito
• Is Part Of: Chemical science. Volume 11:Issue 31(2020)
• Page Start: 8145
• Page End: 8150
• Publication Date: 2020-07-24
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d0sc03223a
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : A complex mixture of atropisomeric M2 L4 cages is shown to undergo perfect convergence to a single isomer upon encapsulation of spherical C60 in water. Moreover, the cage mixture displays very strong guest emission upon encapsulation of a BODIPY dye. Abstract : Introduction of atropisomeric axes into a bent bispyridine ligand leads to the quantitative formation of a complex mixture of atropisomeric M2 L4 cages upon treatment with metal ions. Whereas the isomer ratio of the obtained cage mixture, consisting of up to 42 isomers, is insensitive to temperature and solvent, the quantitative convergence from the mixture to a single isomer is accomplished upon encapsulation of a large spherical guest, namely fullerene C60 . The observed isomerization with other guests depends largely on their size and shape ( e.g., <10 and 82% convergence with planar triphenylene and bowl-shaped corannulene guests, respectively). Besides the unusual guest-induced convergence, the present cage mixture displays the strongest guest emission ( Φ F = 68%) among previously reported M n L m cages and capsules, upon encapsulation of a BODIPY dye in water.