Acta Chim. Sinica ›› 2015, Vol. 73 ›› Issue (8): 819-825.

Article

### 基于六苯基苯骨架四苯基乙烯衍生物的合成及聚集诱导发光性质研究 2016 Awarded

1. 光化学转换与功能材料重点实验室 中国科学院理化技术研究所 北京 100190
• 投稿日期:2015-04-02 发布日期:2015-04-30
• 通讯作者: 曾毅, 李嫕 E-mail:zengyi@mail.ipc.ac.cn;yili@mail.ipc.ac.cn
• 基金资助:

项目受科技部国家重点基础研究发展计划(Nos. 2013CB834703, 2013CB834505)和国家自然科学基金(Nos. 21273258, 21233011, 21172229, 21004072)资助.

### Synthesis and Aggregation-induced Emission of Tetraphenylethylene Derivatives Based on Hexakisphenylbenzene Backbone

Xun Zhiqing, Tang Haiyun, Zeng Yi, Chen Jinping, Yu Tianjun, Zhang Xiaohui, Li Yi

1. Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190
• Received:2015-04-02 Published:2015-04-30
• Supported by:

Project supported by the 973 Program (Nos. 2013CB834703, 2013CB834505) and the National Natural Science Foundation of China (Nos. 21273258, 21233011, 21172229, 21004072).

A series of tetraphenylethylene (TPE) derivatives based on hexakisphenylbenzene backbone (HPB-nTPE, n=2, 4, 6) were synthesized by cobalt carbonyl-catalyzed cyclotrimerization of alkynes with 1,2-bis(4-(tert-butyl)phenyl)ethyne and 1,2-bis(4'-(1,2,2-triphenylvinyl)-[1,1'-biphenyl]-4-yl)ethyne (TPE-TPE) as starting materials. By varying the ratio of the starting materials, HPB-nTPE (n=2, 4, 6) with 2, 4 or 6 TPE substituents were obtained. The structures of HPB-nTPE (n=2, 4, 6) were characterized by IR, 1H NMR and MALDI-TOF mass spectra. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) show that the decomposition temperatures of HPB-nTPE are all above 440 ℃, indicative of high thermal stability of HPB-nTPE. The photophysical properties of the tetrahydrofuran solution, the aggregate and the neat solid of HPB-nTPE were investigated. The aggregates of HPB-nTPE (n=2, 4, 6) were obtained in tetrahydrofuran/water mixed solvents with various volume fractions of water, which was confirmed by the scanning electron microscope (SEM). HPB-nTPE (n=2, 4, 6) show typical aggregation induced emission properties, almost non-emissive in tetrahydrofuran solution, but strongly emissive in the aggregate or solid state. The highest fluorescence quantum yields for HPB-nTPE (n=2, 4, 6) in aggregate state are 0.37, 0.36 and 0.37, respectively, which are more than 400 times higher than that in tetrahydrofuran. The quantum yields of the neat solid of HPB-nTPE (n=2, 4, 6) are determined to be 0.39, 0.36 and 0.36, which are ca. 1.8 times of that of the neat solid of tetraphenylethylene. Both restrictions of the intramolecular rotation of phenyl rings and the inter/intramolecular π-π stacking of the TPE chromophores caused by the star-shape rigidity structure of hexakisphenylbenzene suppress the nonradiative transition, consequently, giving higher fluorescence quantum yield of the aggregates and the neat solid of HPB-nTPE in comparison with TPE. This work is of importance for developing highly emissive organic materials in solid states.