Effect of fluorine substitution on tetraphenylethene-benzothiadiazole based AIE-active copolymers

Abstract

The influence of fluorine substitution on the aggregation-induced emission enhancement of alternating tetraphenylethene–benzothiadiazole copolymers pBTPE and pBFTPE is investigated. The presence of difluorobenzothiadiazole in pBFTPE significantly enhances the intensity of emission upon aggregation, whereas pBTPE without fluorinated substituents exhibits relatively weak aggregation-enhanced emission. Furthermore, both the TEM image and 2-D GIWAXS reveal a denser packing for pBFTPE. The fluorine atoms on the polymer backbone may promote more pronounced inter-polymer interactions, improving molecular packing and resulting in a conformational difference. It may dictate the nature of aggregation between polymers and the resulting photophysical behavior.