Photo-controlled fluorescence on/off switching of a pseudo[3]rotaxane between an AIE-active pillar[5]arene host and a photochromic bithienylethene guest.

A fluorescence photo-switch was constructed based on a host-guest pseudo[3]rotaxane between an AIE-active pillar[5]arene host bearing tetraphenyl ethylene moieties and a photo-responsive dithienylethylene guest containing two cyano-triazole branches. Its fluorescence on/off switching could be controlled by the photochromism reaction of the dithienylethylene unit.