Guo Jingjing, Li Jianqing, Wu Tai, Peng Xiaoluo, Wang Shihuai, Zhao Zujin, Hua Yong, Tang Ben Zhong, Zhao Yanli
State Key Laboratory of Luminescent Materials and Devices, Key Laboratory of Luminescence from Molecular Aggregates of Guangdong Province, South China University of Technology, Guangzhou 510640, China.
School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
J Am Chem Soc. 2023 Apr 12;145(14):7837-7844. doi: 10.1021/jacs.2c12738. Epub 2023 Mar 30.
As an important category of photochemical reactions, photocyclization is regarded as an ideal entry point for building intelligent photoresponsive materials. Herein, a series of aggregation-induced emission luminogens (AIEgens) with sensitive photoresponsive behavior are developed based on 2,3-diphenylbenzo[]thiophene -dioxide (DP-BTO), and the impacts of substituents with different electronic structures are investigated. The comprehensive experimental and computational characterizations reveal that their photoresponsive activity is resulted from triplet diradical-mediated intramolecular photocyclization, followed by dehydrogenation to yield stable polycyclic photoproducts. This photocyclization process is active in solution but suppressed in the solid state, and thus can act as a supplementary nonradiative decay channel for the excited state to contribute to AIE effect. Moreover, the generated triplet diradical intermediates upon light irradiation can effectively inhibit the growth of , indicative of their promising application as antibacterial agents. This work provides an in-depth mechanistic description about the photocyclization of DP-BTO derivatives and furnishes a perspective on the correlation of photochemical decay and photophysical property.
作为光化学反应的一个重要类别，光环化被视为构建智能光响应材料的理想切入点。在此，基于2,3-二苯基苯并噻吩二氧化物（DP-BTO）开发了一系列具有敏感光响应行为的聚集诱导发光发光团（AIEgens），并研究了不同电子结构取代基的影响。全面的实验和计算表征表明，它们的光响应活性源于三线态双自由基介导的分子内光环化，随后脱氢生成稳定的多环光产物。这种光环化过程在溶液中是活跃的，但在固态中受到抑制，因此可以作为激发态的补充非辐射衰变通道，对AIE效应做出贡献。此外，光照下产生的三线态双自由基中间体可以有效抑制细菌的生长，表明它们作为抗菌剂具有广阔的应用前景。这项工作提供了关于DP-BTO衍生物光环化的深入机理描述，并为光化学衰变与光物理性质的相关性提供了一个视角。
