Photomechanical macroscopic movements driven by photoinduced topochemical[2+2]cycloaddition reaction in tridentate cyanostilbene  

三齿氰基苯乙烯中光诱导的拓扑化学[2+2]环加成反应驱动的宏观光机械运动

作　　者：Hui Yu Shuyu Li Wenbo Wu Yutong Yao Jiaxuan Zhu Haoqiang Qi Ting Wang Xin Huang Na Wang Hongxun Hao 余辉;李澍雨;武文波;姚昱同;朱家萱;齐浩强;王霆;黄欣;王娜;郝红勋

机构地区：[1]National Engineering Research Center of Industrial Crystallization Technology,School of Chemical Engineering and Technology,Tianjin University,Tianjin,300072,China [2]Collaborative Innovation Center of Chemical Science and Engineering(Tianjin),Tianjin,300072,China

出　　处：《Science China Materials》2025年第4期1038-1046,共9页中国科学(材料科学)(英文版)

基　　金：supported by the National Natural Science Foundation of China(22208237)。

摘　　要：Photomechanical crystals are capable of converting light energy into mechanical energy, making them as potential candidates for a wide range of applications in areas such as actuators, artificial muscles, and optical switches. In this work, we successfully synthesized a tridentate cyano styrene derivative molecule, (2Z,2′Z,2′Z)-3,3′,3′-(benzene-1,3,5-triyl)tris-(2-(4-(trifluoromethoxyl)ph-enyl)acrylonitrile) (C3-CF3), along with its three different polymorphs. Both blocky Form I and sheet-like Form II, exhibit photosalient effects (ballistic splitting, moving, and jumping) under both ultraviolet and visible lasers. More importantly, they could even respond to sunlight and light-emitting diode white light with a subdued photomechanical response. 1H nuclear magnetic resonance indicates that Form I and Form II undergo photo-induced [2 + 2] cycloaddition reactions under various light sources. The kinetic analysis of the photoreactions reveals that both polymorphs demonstrate rapid reaction kinetics and high photodimerization conversion when exposed to 420 nm visible laser, with conversions reaching 97.6% and 95.26% after 300 s of irradiation, respectively. Additionally, although the needle-shaped Form III of C3-CF3 lacks photomechanical activity, it possesses notable mechanical flexibility. Finally, films composed of powders from Form I or Form II with poly(vinyl alcohol) were created, which were capable of controllable photo-induced bending.光机械晶体能够将光能转化为机械能,其在致动器、人造肌肉和光开关等领域具有巨大的应用潜力.在本研究中,我们设计并合成了一种三齿氰基苯乙烯衍生物(2Z,2′Z,2′Z)-3,3′,3′-(苯-1,3,5-三烷基)三-(2-(4-(三氟甲氧基)苯基)丙烯腈)(C3-CF3).C3-CF3的块状晶型Ⅰ和片状晶Ⅱ在紫外光或420 nm可见光照射下都表现出爆裂和突然跳跃的光显著效应.同时,晶型Ⅰ和晶型Ⅱ在太阳光和LED白光照射下也表现出缓慢的光机械运动.1H NMR表明,晶型Ⅰ和晶型Ⅱ在各种光源下发生光诱导的[2+2]环加成反应.光反应动力学研究表明,在420 nm可见光照射300秒后,晶型Ⅰ和晶型Ⅱ的转化率分别达到97.6%和95.26%.此外,不具备光活性的针状晶型Ⅲ具有良好的机械弹性.最后,分别将晶型Ⅰ和晶型Ⅱ的粉末与聚乙烯醇(PVA)结合制备成光诱导定向弯曲的复合薄膜IPVA和Ⅱ-PVA.

关 键 词：cyanostilbene photomechanical crystals photosalient visible light CYCLOADDITION 

分 类 号：O621.2[理学—有机化学]