Highly emissive D-A-π-D type aggregation-induced emission (AIE) or aggregation-induced emission enhancement (AIEE)-active benzothiadiazole derivatives with contrasting mechanofluorochromic features

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2022-06, Vol.274, p.121122, Article 121122
• Main Authors: Liu, Shanting, Yang, Yue, Deng, Dian-dian, Deng, Xiao-wen, Chen, Zhao, Wang, Xiao-Yan, Pu, Shouzhi
• Format: Article
• Language: English
• Subjects: Aggregation-induced emission; Aggregation-induced emission enhancement; Anthracene; Benzothiadiazole; Different solid state fluorescence; Three-color mechanofluorochromism
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2022.121122

[Display omitted] •Three D-A-π-D type benzothiadiazole derivatives were synthesized.•Compound 1 showed typical aggregation-induced emission effect.•Compounds 2 and 3 showed typical aggregation-induced emission enhancement features.•Luminophor 1 exhibited a two-color mechanofluorochromic phenomenon.•Luminophors 2 and 3 demonstrated interesting three-color mechanofluorochromic characteristics. Mechanochromic luminophors with strong solid-state emission are promising candidates for high-contrast mechanochromic luminescence materials. Meanwhile, mechanically responsive luminogenic molecules with tricolor switching are highly desirable but are seldom reported. In this work, three anthracene-based donor–acceptor-π-donor (D-A-π-D) type benzothiadiazole derivatives were designed and synthesized. These luminogens showed remarkable aggregation-induced emission (AIE) or aggregation-induced emission enhancement (AIEE) effect. Furthermore, these luminogens exhibited bright and different solid state fluorescence involving yellow-green, yellow and orange colors, and the fluorescence of their solids could be effectively regulated by mechanical grinding. For luminogen 1, its solid displayed reversible two-color mechanofluorochromic property. As for luminogens 2 and 3, their solids displayed fluorescent colors change from yellow to yellow-green upon slight grinding, and the yellow-green light-emitting solids were converted into orange fluorescent solids after heavy grinding, demonstrating interesting three-color mechanofluorochromism features.