中国物理B ›› 2018, Vol. 27 ›› Issue (2): 23103-023103.doi: 10.1088/1674-1056/27/2/023103

• SPECIAL TOPIC—Soft matter and biological physics (Review) • 上一篇    下一篇

Excited state intramolecular proton transfer mechanism of o-hydroxynaphthyl phenanthroimidazole

Shuang Liu(刘爽), Yan-Zhen Ma(马艳珍), Yun-Fan Yang(杨云帆), Song-Song Liu(刘松松), Yong-Qing Li(李永庆), Yu-Zhi Song(宋玉志)   

  1. 1. School of Physics and Electronics, Shandong Normal University, Jinan 250014, China;
    2. Department of Physics, Liaoning University, Shenyang 110036, China
  • 收稿日期:2017-10-10 修回日期:2017-11-22 出版日期:2018-02-05 发布日期:2018-02-05
  • 通讯作者: Yong-Qing Li, Yu-Zhi Song E-mail:yqli@lnu.edu.cn;yzsong@sdnu.edu.cn
  • 基金资助:

    Project supported by the Shandong Provincial Higher Educational Science and Technology Program, China (Grant No. J17KA186), the Taishan Scholar Project of Shandong Province, China, the Natural Science Foundation of Liaoning Province, China (Grant No. 20170540408), and the Science and Technology Plan Project of Shenyang City, China (Grant No. 17-231-1-06).

Excited state intramolecular proton transfer mechanism of o-hydroxynaphthyl phenanthroimidazole

Shuang Liu(刘爽)1, Yan-Zhen Ma(马艳珍)2, Yun-Fan Yang(杨云帆)2, Song-Song Liu(刘松松)1, Yong-Qing Li(李永庆)2, Yu-Zhi Song(宋玉志)1   

  1. 1. School of Physics and Electronics, Shandong Normal University, Jinan 250014, China;
    2. Department of Physics, Liaoning University, Shenyang 110036, China
  • Received:2017-10-10 Revised:2017-11-22 Online:2018-02-05 Published:2018-02-05
  • Contact: Yong-Qing Li, Yu-Zhi Song E-mail:yqli@lnu.edu.cn;yzsong@sdnu.edu.cn
  • About author:31.15.ae; 31.15.A-; 31.15.es
  • Supported by:

    Project supported by the Shandong Provincial Higher Educational Science and Technology Program, China (Grant No. J17KA186), the Taishan Scholar Project of Shandong Province, China, the Natural Science Foundation of Liaoning Province, China (Grant No. 20170540408), and the Science and Technology Plan Project of Shenyang City, China (Grant No. 17-231-1-06).

摘要:

By utilizing the density functional theory (DFT) and the time-dependent density functional theory (TDDFT), the excited state intramolecular proton transfer (ESIPT) mechanism of o-hydroxynaphthyl phenanthroimidazole (HNPI) is studied in detail. Upon photo is excited, the intramolecular hydrogen bond is obviously enhanced in the S1 state, which thus promotes the ESIPT process. Hydrogen bond is shown to be strengthened via comparing the molecular structures and the infrared vibration spectra of the S0 and S1 states. Through analyzing the frontier molecular orbitals, we can conclude that the excitation is a type of the intramolecular charge transfer excitation, which also indicates the trend of proton transfer in S1 state. The vertical excitation based on TDDFT calculation can effectively repeat the absorption and fluorescence spectra of the experiment. However, the fluorescence spectrum of normal structure, which is similar to the spectrum of isomer structure is not detected in the experiment. It can be concluded that the fluorescence measured in the experiment is attributed to both structures. In addition, by analyzing the potential energy curves (PECs) calculated by the B3LYP functional method, it can be derived that since the molecule to cross the potential barrier in the S1 state is smaller than in the S0 state and the reverse proton transfer process in the S1 state is more difficult than in the S0 state, the ESIPT occurs in the S1 state.

关键词: hydrogen bond, ESIPT, RDG, PECs

Abstract:

By utilizing the density functional theory (DFT) and the time-dependent density functional theory (TDDFT), the excited state intramolecular proton transfer (ESIPT) mechanism of o-hydroxynaphthyl phenanthroimidazole (HNPI) is studied in detail. Upon photo is excited, the intramolecular hydrogen bond is obviously enhanced in the S1 state, which thus promotes the ESIPT process. Hydrogen bond is shown to be strengthened via comparing the molecular structures and the infrared vibration spectra of the S0 and S1 states. Through analyzing the frontier molecular orbitals, we can conclude that the excitation is a type of the intramolecular charge transfer excitation, which also indicates the trend of proton transfer in S1 state. The vertical excitation based on TDDFT calculation can effectively repeat the absorption and fluorescence spectra of the experiment. However, the fluorescence spectrum of normal structure, which is similar to the spectrum of isomer structure is not detected in the experiment. It can be concluded that the fluorescence measured in the experiment is attributed to both structures. In addition, by analyzing the potential energy curves (PECs) calculated by the B3LYP functional method, it can be derived that since the molecule to cross the potential barrier in the S1 state is smaller than in the S0 state and the reverse proton transfer process in the S1 state is more difficult than in the S0 state, the ESIPT occurs in the S1 state.

Key words: hydrogen bond, ESIPT, RDG, PECs

中图分类号:  (Electronic structure and bonding characteristics)

  • 31.15.ae
31.15.A- (Ab initio calculations) 31.15.es (Applications of density-functional theory (e.g., to electronic structure and stability; defect formation; dielectric properties, susceptibilities; viscoelastic coefficients; Rydberg transition frequencies))