Aggregation-induced emission based on a fluorinated macrocycle: visualizing spontaneous and ultrafast solid-state molecular motions at room temperature F F interactions

We for the first time report the efficient construction of novel tetraphenethylene (TPE)-based macrocycles with various mechanofluorochromism (MFC) behaviors involving solid-state molecular motions. We were able to facilely regulate the diverse solid-state molecular motion behaviors of 18-33-membered macrocycles by adjusting the sizes and shapes of the macrocycle rings. Notably, the building of an intermolecular 6-membered ring between two 20-membered fluorinated macrocycles via F F interactions afforded macrocycle 6F-2 , which exhibited changes in MFC behaviors that could be rapidly reversed, i.e. , within 100 seconds, at room temperature. X-ray structural analysis supported the unique role of fluorinated macrocycles in self-reversible MFC and the emission variation, particularly, in visualization of solid-state molecular motion. We report the first example of fluorinated macrocycle, where two adjacent 6F-2 macrocycles were linked by two C-F F-C halogen interactions, which endowed the molecule with autonomous and rapid MFC reversibility, within 100 s, at room temperature.