Li Jie, Zhang Yang, Mei Ju, Lam Jacky W Y, Hao Jianhua, Tang Ben Zhong
Department of Chemistry, Institute for Advanced Study, Institute of Molecular Functional Materials, Division of Biomedical Engineering, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (S.A.R. China).
Chemistry. 2014 Nov 6. doi: 10.1002/chem.405118.
A novel molecular design strategy is provided to rationally tune the stimuli response of luminescent materials with aggregation-induced emission (AIE) characteristics. A series of new AIE-active molecules (AIE rotors) are prepared by covalently linking different numbers of tetraphenylethene moieties together. Upon gradually increasing the number of rotatable phenyl rings, the sensitivity of the response of the AIE rotors to viscosity and temperature is significantly enhanced. Although the molecular size is further enlarged, the performance is only slightly improved due to slightly increased effective rotors, but with largely increased rotational barriers. Such molecular engineering and experimental results offer more in-depth insight into the AIE mechanism, namely, restriction of intramolecular rotations. Notably, through this rational design, the AIE rotor with the largest molecular size turns out to be the most viscosensitive luminogen with a viscosity factor of up to 0.98.
提供了一种新颖的分子设计策略，用于合理调节具有聚集诱导发光（AIE）特性的发光材料的刺激响应。通过将不同数量的四苯乙烯部分共价连接在一起，制备了一系列新型AIE活性分子（AIE转子）。随着可旋转苯环数量的逐渐增加，AIE转子对粘度和温度的响应灵敏度显著提高。尽管分子尺寸进一步增大，但由于有效转子略有增加且旋转势垒大幅增加，性能仅略有改善。这种分子工程和实验结果为AIE机制，即分子内旋转受限，提供了更深入的见解。值得注意的是，通过这种合理设计，分子尺寸最大的AIE转子成为粘度敏感性最高的发光体，粘度因子高达0.98。
