Substituent effects on the mechanochromic behaviour of pyrene-based AIEgens

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2025-02, Vol.459, p.116020, Article 116020
• Main Authors: Yang, Guang, Xue, Zeng-Min, Liang, Ling, Meng, Fei, Liu, Kai-Yue, Wang, Jia-Hao, Lin, Hong-Tao, Zhao, Wen-Xuan, Chen, Shu-Hai, Yamato, Takehiko, Redshaw, Carl, Wang, Chuan-Zeng
• Format: Article
• Language: English
• ISSN: 1010-6030
• DOI: 10.1016/j.jphotochem.2024.116020

A novel strategy was established to comstruct mechanoresponsive pyrene-based AEE luminogens with high fluorescence efficiency and positional effects. Excellent reversibility makes such system very attractive smart photoelectric materials. [Display omitted] •A series of mechanoresponsive pyrene-based AEE luminogens.•The excellent fatigue resistance properties were observed in this system.•An important strategy was established by functionalization in pyrene nodal plane (2- and 7-positions). It is extremely significant and desirable to integrate the fascinating properties of mechanochromism and aggregation-induced emission (AIE) in one simple molecule. Herein, pyrene-based aggregation-induced emission luminogens (AIEgens) with mechanofluorochromic (MFC) properties solve the traditionally existing aggregation-caused quenching (ACQ) challenge. Three cyanoethylene-functionalized pyrene-based derivatives were designed and synthesized. All compounds exhibit remarkable aggregation-enhanced emission (AEE) activity by a 3–20 times enhancement in mixed H2O/THF solutions. More importantly, high fluorescence efficiency was recorded in the solid state, especially for the luminogen 2c, with more than 200 times observed increased efficiency from 0.3% in solution to 69.8% in the solid state. Meanwhile, excellent mechanochromism properties and reversibility against the grinding treatment was systematically investigated. The excellent fatigue resistance properties are a necessity for potential applications in the field of anti-counterfeiting fluorescent inks and for the encryption of security information.