中国物理B ›› 2023, Vol. 32 ›› Issue (2): 28201-028201.doi: 10.1088/1674-1056/ac65f4

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Effects of π-conjugation-substitution on ESIPT process for oxazoline-substituted hydroxyfluorenes

Di Wang(汪迪)1, Qiao Zhou(周悄)1,2,†, Qiang Wei(魏强)3, and Peng Song(宋朋)1,‡   

  1. 1 Department of Physics, Liaoning University, Shenyang 110036, China;
    2 College of Mathematics and Information Engineering, Chongqing University of Education, Chongqing 400065, China;
    3 School of Science, Chongqing University of Technology, Chongqing 400050, China
  • 收稿日期:2022-02-06 修回日期:2022-04-08 接受日期:2022-04-11 出版日期:2023-01-10 发布日期:2023-01-18
  • 通讯作者: Qiao Zhou, Peng Song E-mail:zhouq@cque.edu.cn;songpeng@lnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11974152), the Shenyang High level Innovative Talents Program (Grant No. RC200565), the Science program of Liaoning Provincial Department of Education (Grant No. LJKZ0097), the Intercollegiate cooperation project of colleges and universities of Liaoning Provincial Department of Education.

Effects of π-conjugation-substitution on ESIPT process for oxazoline-substituted hydroxyfluorenes

Di Wang(汪迪)1, Qiao Zhou(周悄)1,2,†, Qiang Wei(魏强)3, and Peng Song(宋朋)1,‡   

  1. 1 Department of Physics, Liaoning University, Shenyang 110036, China;
    2 College of Mathematics and Information Engineering, Chongqing University of Education, Chongqing 400065, China;
    3 School of Science, Chongqing University of Technology, Chongqing 400050, China
  • Received:2022-02-06 Revised:2022-04-08 Accepted:2022-04-11 Online:2023-01-10 Published:2023-01-18
  • Contact: Qiao Zhou, Peng Song E-mail:zhouq@cque.edu.cn;songpeng@lnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11974152), the Shenyang High level Innovative Talents Program (Grant No. RC200565), the Science program of Liaoning Provincial Department of Education (Grant No. LJKZ0097), the Intercollegiate cooperation project of colleges and universities of Liaoning Provincial Department of Education.

摘要: Excited-state intramolecular proton transfer (ESIPT) molecules are broadly applied to UV absorbers, fluorescence sensing, and lighting materials. In previous work, the fluorescence colors of oxazoline-substituted hydroxyfluorenes and hydroxylated benzoxazole were diversified by adding the π-conjugation. There is intriguing that the mechanism of diversified fluorescence colors induced by ESIPT. Here, the density functional theory (DFT) and time-dependent DFT (TDDFT) are advised to identify the effects of π-conjugation on ESIPT and photophysical properties. The stabilized geometrical configurations, frontier molecular orbitals (FMOs) isosurfaces, and O-H stretching vibration frequency analysis demonstrate that PT processes are more active in S1 state. Constructing the minimum energy pathways of ESIPT processes, we find that the calculated peak of enol and keto fluorescence of naphthoxazole (NO-OH) is distinctly bathochromic-shift relative to the oxazoline-substituted hydroxyfluorenes (Oxa-OH) configuration when adding π-conjugation-substitution, and it means that π-conjugation-substitution can diversify the fluorescence color. We hope our studies can establish new channels to devise the ESIPT-based molecules.

关键词: density functional theory (DFT) and time-dependent DFT (TDDFT), excited-state proton transfer, intramolecular hydrogen bonding, π -conjugation-substitution

Abstract: Excited-state intramolecular proton transfer (ESIPT) molecules are broadly applied to UV absorbers, fluorescence sensing, and lighting materials. In previous work, the fluorescence colors of oxazoline-substituted hydroxyfluorenes and hydroxylated benzoxazole were diversified by adding the π-conjugation. There is intriguing that the mechanism of diversified fluorescence colors induced by ESIPT. Here, the density functional theory (DFT) and time-dependent DFT (TDDFT) are advised to identify the effects of π-conjugation on ESIPT and photophysical properties. The stabilized geometrical configurations, frontier molecular orbitals (FMOs) isosurfaces, and O-H stretching vibration frequency analysis demonstrate that PT processes are more active in S1 state. Constructing the minimum energy pathways of ESIPT processes, we find that the calculated peak of enol and keto fluorescence of naphthoxazole (NO-OH) is distinctly bathochromic-shift relative to the oxazoline-substituted hydroxyfluorenes (Oxa-OH) configuration when adding π-conjugation-substitution, and it means that π-conjugation-substitution can diversify the fluorescence color. We hope our studies can establish new channels to devise the ESIPT-based molecules.

Key words: density functional theory (DFT) and time-dependent DFT (TDDFT), excited-state proton transfer, intramolecular hydrogen bonding, π -conjugation-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)