HKUST-Shenzhen Research Institute , No. 9 Yuexing first RD, South Area, Hi-tech Park, Nanshan, Shenzhen 518057, China.
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Institute of Molecular Functional Materials, Institute for Advanced Study, Division of Biomedical Engineering and Division of Life Science, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong, China.
J Am Chem Soc. 2018 Feb 7;140(5):1966-1975. doi: 10.1021/jacs.7b13364. Epub 2018 Jan 27.
Seeking new methods to obtain elaborate artificial on-demand photoswitching with multiple functionalities remains challenging. Most of the systems reported so far possess only one specific function and their nonemissive nature in the aggregated state inevitably limit their applications. Herein, a tailored cyanostilbene-based molecule with aggregation-induced emission characteristic was synthesized and was found to exhibit efficient, multiple and controllable photoresponsive behaviors under different conditions. Specifically, three different reactions were involved: (i) reversible Z/E isomerization under room light and thermal treatment in CHCN, (ii) UV-induced photocyclization with a concomitant dramatic fluorescence enhancement, and (iii) regio- and stereoselective photodimerization in aqueous medium with microcrystal formation. Experimental and theoretical analyses gave visible insights and detailed mechanisms of the photoreaction processes. Fluorescent 2D photopattern with enhanced signal-to-background ratio was fabricated based on the controllable "turn-on" and "turn-off" photobehaviors in different states. The present study thus paves an easy yet efficient way to construct smart multiphotochromes for unique applications.
寻求新的方法来获得具有多种功能的精细人工按需光开关仍然具有挑战性。到目前为止，大多数报道的系统只具有一种特定的功能，它们在聚集状态下的非发光性质不可避免地限制了它们的应用。在此，合成了一种具有聚集诱导发射特性的定制氰基二苯乙烯基分子，发现在不同条件下表现出高效、多重和可控的光响应行为。具体而言，涉及三种不同的反应：(i) 在室温下和 CHCN 中的热处理下的可逆 Z/E 异构化，(ii) 伴随荧光显著增强的 UV 诱导环化，以及 (iii) 在水介质中微晶体形成的区域和立体选择性光二聚化。实验和理论分析提供了对光反应过程的可见见解和详细机制。基于不同状态下可控的“开启”和“关闭”光致行为，制备了具有增强的信号与背景比的荧光 2D 光图案。因此，本研究为独特应用构建智能多光色体提供了一种简单而有效的方法。
