化学学报 ›› 2011, Vol. 69 ›› Issue (12): 1415-1424. 上一篇    下一篇

研究论文

侧链取代的芴苯共聚物的光电性质及其溶剂化效应研究

刘天西*,1,2,杨贵忠2,韦春*,1   

  1. (1有色金属及材料加工新技术教育部重点实验室 桂林理工大学材料科学与工程学院 桂林541004)
    (2聚合物分子工程教育部重点实验室 复旦大学高分子科学系 上海200433)
  • 投稿日期:2011-01-25 修回日期:2011-02-15 发布日期:2011-02-25
  • 通讯作者: 刘天西 E-mail:txliu@fudan.edu.cn

Side Chain and Solvation Effects on the Photophysical Properties of Fluorene-alt-Benzene Based Conjugated Block Copolymers

Liu Tianxi*,1,2 Yang Guizhong2 Wei Chun*,1   

  1. (1 Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Ministry of Education, Guilin University of Technology, Guilin 541004) (2 Key Laboratory of Molecular Engineering of Polymers of Ministry of Education, Department of Macromolecular Science, Fudan University, Shanghai 200433)
  • Received:2011-01-25 Revised:2011-02-15 Published:2011-02-25
  • Contact: Tianxi Liu E-mail:txliu@fudan.edu.cn

采用Suzuki偶联聚合的方法合成了一系列化学结构明确、侧基性质(长度、体积、给/吸电子性质)不同的Hairy-Rod型芴苯共聚物. 通过光谱、电化学和模拟计算等手段研究了苯环上不同性质的侧基取代芴苯聚合物的发光性质、电化学性质和溶剂化效应等, 同时研究了侧基性质的变化对这些物理性质的影响规律. 苯环上烷基侧链长度的改变对取代共聚物的光谱、电化学和发光效率等影响很小|而随着苯环上烷氧基侧链长度的增加, 聚合物的光谱稳定性逐渐增强, 荧光发射光谱中的0-1转变逐渐被抑制, 荧光发射半峰宽减小. 苯环上取代侧基的给/吸电子性质变化对聚合物的光电性能具有全面的影响, 改变取代侧基的给/吸电子性质可调节芴苯共聚物的发光颜色和HOMO, LUMO能级以及HOMO-LUMO能隙等, 因此, 通过引入不同性质的侧基可实现对此类聚合物光物理性能的调控. 溶剂的极性对聚合物溶液的光谱性质具有显著影响, 溶液光谱随溶剂极性的增大逐渐向长波移动. 当聚合物本身带有强极性基团时, 在强极性溶剂中将发生聚合物分子链与溶剂分子间的强极性相互作用, 从而会引起更复杂的结果.

关键词: 聚芴, 共聚物, 侧链, 光电性能, 溶剂化效应

A series of hairy-rod fluorene-alt-benzene based conjugated polymers with different substituted groups on phenylene were synthesized through Suzuki coupling polymerization. The optical properties, fluorescence quantum yields (QY) and electrochemical properties of these polymers were investigated. It was found that the optical properties of the polymers did not show obvious dependence on the alkyl length on phenylene. However, the spectral stability was increased, and the 0-1 transition and the full width at the half-maximum (FWHM) of photoluminescence spectra were decreased with the increase of the alkoxy length on phenylene. The nature (e.g. electron-donating and electron-withdrawing) of the substituted side groups on phenylene has obvious effect on the optical properties, QY and electrochemical properties of the polymers. Thus, the photophysical properties of the polymers can be tuned by attaching different substituted side groups onto the phenylene. The spectra of the polymers in solutions exhibit dependence on dielectric constants of the solvents used, and the spectra of the polymer solutions shift to longer wavelength with increasing the dielectric constants of the solvents.

Key words: polyfluorene, block copolymer, side chain, photophysical property, solvation effect