Yang Shuaijun, Zhou Shaoxin, Li Hui, Nie Yong, Xu Huiyan, Liu Wei, Miao Jinling, Li Yexin, Gao Ge, You Jingsong, Jiang Xuchuan
Institute for Smart Materials & Engineering, University of Jinan, No. 336 Nanxinzhuang West Road, 250022 Jinan, P.R. China.
School of Chemistry and Chemical Engineering, University of Jinan, No. 336 Nanxinzhuang West Road, 250022 Jinan, P.R. China.
ACS Appl Mater Interfaces. 2022 Apr 13;14(14):16611-16620. doi: 10.1021/acsami.2c00468. Epub 2022 Mar 29.
Stimuli-responsive organic materials with controllable luminescence are of enormous importance because of their potential applications in sensing, data security, and display devices. In this study, a multistimuli-responsive squaraine dyad () composed of two rigid squaraine moieties and a flexible ethylene linker was rationally designed and synthesized. exhibits polymorphic luminescence, which can be reversibly switched by various external stimuli, including solvent vapor exposure, heat, and shear force. Unexpectedly, the weakly luminescent phase (O1) of exhibits concentration-controlled vapochromic behavior. Film O1 can convert to a highly green-emissive phase (G1) under a low concentration of CHCl vapor and convert to a highly yellow-emissive phase (Y) under a high concentration of CHCl vapor; these originate from two distinct crystallization-induced emission enhancement processes. To the best of our knowledge, this is the first investigation of the effect of vapor concentration on the phase transitions of organic vapochromic luminophores. By analyzing the single-crystal structures and photophysical properties of , we concluded that the green and yellow emissions probably originated from a zigzag stacking mode and an H-type π-π stacking mode, respectively. Finally, two prototypes based on for applications in information encryption and vapor sensing were successfully demonstrated.
具有可控发光的刺激响应性有机材料因其在传感、数据安全和显示设备中的潜在应用而具有极其重要的意义。在本研究中，合理设计并合成了一种由两个刚性方酸部分和一个柔性乙烯连接体组成的多刺激响应性方酸二元体（）。表现出多晶型发光，可通过各种外部刺激（包括暴露于溶剂蒸汽、加热和剪切力）进行可逆切换。出乎意料的是，的弱发光相（O1）表现出浓度控制的气致变色行为。薄膜O1在低浓度CHCl蒸汽下可转变为高绿色发射相（G1），在高浓度CHCl蒸汽下可转变为高黄色发射相（Y）；这些源自两个不同的结晶诱导发射增强过程。据我们所知，这是首次研究蒸汽浓度对有机气致变色发光体相变的影响。通过分析的单晶结构和光物理性质，我们得出结论，绿色和黄色发射可能分别源自锯齿形堆积模式和H型π-π堆积模式。最后，成功展示了基于的用于信息加密和蒸汽传感的两个原型。
