Chin. J. Org. Chem. ›› 2019, Vol. 39 ›› Issue (7): 2009-2017.DOI: 10.6023/cjoc201902015 Previous Articles     Next Articles

Special Issue: 有机超分子化学合辑



鄢剑锋a, 张睿祺a, 原野a, 袁耀锋a,b   

  1. a 福州大学化学学院 福州 350116;
    b 中国科学院福建物质结构研究所 结构化学国家重点实验室 福州 350002
  • 收稿日期:2019-02-18 修回日期:2019-03-10 发布日期:2019-03-21
  • 通讯作者: 袁耀锋
  • 基金资助:


4,4'-Dimethoxy-triphenylamine Conjugated Azobenzene Photochromic Switches:Synthesis, Electrochemical and Photoisomerization Studies

Yan Jianfenga, Zhang Ruiqia, Yuan Yea, Yuan Yaofenga,b   

  1. a College of Chemistry, Fuzhou University, Fuzhou 350116)(b State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002
  • Received:2019-02-18 Revised:2019-03-10 Published:2019-03-21
  • Contact: 10.6023/cjoc201902015
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 21772023), the Research Fund for the State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences (No. 20180020) and the Valuable Instrument and Equipment Open Test Fund of Fuzhou University (No. 2018T006).

Three azobenzenes 4~6 conjugated with 4,4'-dimethoxy-triphenylamine redox center have been synthesized by palladium-catalyzed Sonogashira coupling reactions in moderate yield after column chromatographic purification. They are all stable when exposed in air and moisture in both the solid and solution state. The 1H NMR spectra of 4~6 showned that the azobenzene groups are in the trans configuration. The UV/Vis spectra of the target molecule were studied. The UV/Vis absorption bands of 4~6 are less clearly separated, which is similar to those for aminoazobenzen or pseudostilbene. The absorption bands at the ππ* band of 4 and 6 are redshifted, due to the strong electronic interaction between the azobenzene unit and the para-triphenylamine unit, which results in the formation of a longer conjugation system than the corresponding meta isomers. Electrochemical and spectroelectrochemical studies indicate excellent redox reversibility of these compounds. Significant spectra change upon the process of redox makes these compounds have potential applications of electrochemical switching. Among the derivatives, compound 4 exhibits the highest cis form (45%) in the photostationary state (PSS) upon light irradiation at 435 nm. The photoisomerization studies indicate that the photochemistry properties is strongly influenced by the substituted position of the triphenylamine moiety. Photoisomerization studies showed that these compounds have fast photoisomerization rate due to the higher photoisomerization quantum yield, which is an order of magnitude larger than that of ferrocenyl (ethynyl) azobenzenes. Both compounds 4 and 6 exhibit excellent fatigue resistance and reversibility under several repeated reversible isomerization cycles. The cis-to-trans photoisomerization of 4 can be not only achieved by irradiation at UV lignt, but also realized by a more efficient way of change the state of redox center. Our study will provide a good basis for research in design new type of multiple-response molecular switches.

Key words: triphenylamine, azobenzene, photoisomerization, redox