中国物理B ›› 2022, Vol. 31 ›› Issue (3): 38202-038202.doi: 10.1088/1674-1056/ac21c6

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A DFT/TD-DFT study of effect of different substituent on ESIPT fluorescence features of 2-(2'-hydroxyphenyl)-4-chloro- methylthiazole derivatives

Shen-Yang Su(苏申阳), Xiu-Ning Liang(梁秀宁), and Hua Fang(方华)   

  1. Department of Chemistry and Material Science, College of Science, Nanjing Forestry University, Nanjing 210037, China
  • 收稿日期:2021-05-15 修回日期:2021-05-15 接受日期:2021-08-27 出版日期:2022-02-22 发布日期:2022-02-24
  • 通讯作者: Shen-Yang Su E-mail:susanfang20@gmail.com

A DFT/TD-DFT study of effect of different substituent on ESIPT fluorescence features of 2-(2'-hydroxyphenyl)-4-chloro- methylthiazole derivatives

Shen-Yang Su(苏申阳), Xiu-Ning Liang(梁秀宁), and Hua Fang(方华)   

  1. Department of Chemistry and Material Science, College of Science, Nanjing Forestry University, Nanjing 210037, China
  • Received:2021-05-15 Revised:2021-05-15 Accepted:2021-08-27 Online:2022-02-22 Published:2022-02-24
  • Contact: Shen-Yang Su E-mail:susanfang20@gmail.com

摘要: Based on density functional theory (DFT) and time-dependent density functional theory (TD-DFT), the effects of substituent on the excited-state intramolecular proton transfer (ESIPT) process and photophysical properties of 2-(2'-hydroxyphenyl)-4-chloromethylthiazole (HCT) are studied. The electron-donating group (CH3, OH) and electron-withdrawing group (CF3, CHO) are introduced to analyze the changes of intramolecular H-bond, the frontier molecular orbitals, the absorption/fluorescence spectra, and the energy barrier of ESIPT process. The calculation results indicate that electron-donating group strengthens the intramolecular H-bond in the S1 state, and leads to an easier ESIPT process. The electron-withdrawing group weakens the corresponding H-bond and makes ESIPT process a little harder. Different substituents also affect the photophysical properties of HCT. The electron-withdrawing group (CF3, CHO) has a little effect on electronic spectra. The electron-donating group (CH3, OH) red-shifts both the absorption and fluorescence emission peaks of HCT, respectively, which causes the Stokes shift to increase.

关键词: excited-state intramolecular proton transfer (ESIPT), TD-DFT, substitution

Abstract: Based on density functional theory (DFT) and time-dependent density functional theory (TD-DFT), the effects of substituent on the excited-state intramolecular proton transfer (ESIPT) process and photophysical properties of 2-(2'-hydroxyphenyl)-4-chloromethylthiazole (HCT) are studied. The electron-donating group (CH3, OH) and electron-withdrawing group (CF3, CHO) are introduced to analyze the changes of intramolecular H-bond, the frontier molecular orbitals, the absorption/fluorescence spectra, and the energy barrier of ESIPT process. The calculation results indicate that electron-donating group strengthens the intramolecular H-bond in the S1 state, and leads to an easier ESIPT process. The electron-withdrawing group weakens the corresponding H-bond and makes ESIPT process a little harder. Different substituents also affect the photophysical properties of HCT. The electron-withdrawing group (CF3, CHO) has a little effect on electronic spectra. The electron-donating group (CH3, OH) red-shifts both the absorption and fluorescence emission peaks of HCT, respectively, which causes the Stokes shift to increase.

Key words: excited-state intramolecular proton transfer (ESIPT), TD-DFT, substitution

中图分类号:  (Charge (electron, proton) transfer in biological systems)

  • 82.39.Jn
31.15.ee (Time-dependent density functional theory) 87.15.ht (Ultrafast dynamics; charge transfer)