Acta Chim. Sinica ›› 2019, Vol. 77 ›› Issue (8): 751-757.DOI: 10.6023/A19040109 Previous Articles     Next Articles



秦小转a, 王新潮b, 冯丹丹a, 贺加贝c, 郑丽萍a, 王勇a, 谢光辉a, 李靖靖a, 丁戈d   

  1. a 郑州工程技术学院化工食品学院 郑州 450044;
    b 菏泽学院药学院 菏泽 274015;
    c 郑州大学国际学院 郑州 450000;
    d 重庆文理学院化学化工学院 重庆 402160
  • 投稿日期:2019-04-01 发布日期:2019-07-12
  • 通讯作者: 秦小转, 王新潮, 丁戈;;
  • 基金资助:


Study on Properties of Excited-state Intermolecular Proton Transfer (ESPT) Reaction Dendrite Containing Benzidine Fragments of Organic Chromophore

Qin Xiaozhuana, Wang Xinchaob, Feng Dandana, He Jiabeic, Zheng Lipinga, Wang Yonga, Xie Guanghuia, Li Jingjinga, Ding Ged   

  1. a Zhengzhou Institute of Technology, School of Chemical Engineering & Food Science, Zhengzhou 450044;
    b Heze University, College of Parmacy, Heze 274015;
    c International College of Zhengzhou University, Zhengzhou 450000;
    d College of Materials and Chemical Engineering, Chongqing University of Arts and Sciences, Chongqing 402160
  • Received:2019-04-01 Published:2019-07-12
  • Contact: 10.6023/A19040109;;
  • Supported by:

    Project supported by the Department of Science and Technology of Henan Province (No. 192102210201) and the Youth Innovation Fund of Zhengzhou Institute of Technology (No. QNCXJJ2018K3).

In this paper, the intermediates 2'-hydroxybiphenyl-2-amine (I1) and 2'-methoxybiphenyl-2-amine (I2) were first synthetized via Suzuki reaction of 2-bromoaniline and arylboronic acid under 80℃. Meanwhile, organic dyes benzidine fragments ((E)-2'-(2-nitrobenzylideneamino)-biphenyl-3-ol (C1) and (E)-2'-(2,4-dinitrobenzylideneamino)-biphenyl-3-ol (C3)) which could undergo intermolecular proton transfer in excited states were synthetized via aminoaldehyde condensation of the intermediates biphenyl-2-amine and corresponding aldehyde. In addition, the dyes without proton transfer segments ((E)-2'-methoxy-N-(2-nitrobenzylidene)biphenyl-3-amine (C2) and (E)-2'-methoxy-N-(2,4-dinitrobenzylidene)biphenyl-3-amine (C4)) were also synthesized to act as references for comparisons experiment. The chemical structures of organic dyes were characterized by nuclear magnetic resonance (NMR) spectra, infrared spectra (IR), high resolution mass spectrometry (HR-MS) as well as elemental analysis. The analysis of X-ray single crystal diffraction and H NMR spectra suggest the presence of internal hydrogen bond with different strength in the target dyes C1 and C3. It indicated that the type of substituents has an effect on the chemical shift of hydroxyl groups, with the electron-withdrawing ability of substituents increases, the hydroxyl shift to higher field. Then the UV/visible spectra also confirm that the target dyes have intermolecular hydrogen bond, while there is no intermolecular hydrogen bond in the reference dyes C2 and C4. The excited-state intermolecular proton transfer (ESPT) properties of the organic dyes were further studied by fluorescence emission spectroscopy. It was found that target dye C3 could occur excited state intermolecular proton transfer (ESPT) via intermolecular hydrogen bonding in non-protonic solvents. In contrast, ESPT properties cannot be processed through hydrogen-bonding interaction of the studied target dye C1 no matter in protonic solvents, non-protonic solvents or in solid state. The target dye C1 and reference dyes (C2 and C4) only show the normal fluorescence emission peaks. It was worth mentioning that with the increasing concentration of C3 in solution, the ESPT reaction ability could be enhanced. Meanwhile, C3 can also occurs ESPT in solid state.

Key words: hydrogen bond, proton transfer, organic chromophore, excited-state, fluorescence emission spectroscopy