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

作　　者：汪迪 周悄 魏强 宋朋 Di Wang;Qiao Zhou;Qiang Wei;Peng Song(Department of Physics,Liaoning University Shenyang 10036,China;Cllge of Mathematics and Information Engineering,Chongqing University of Eduation,Chongqing 400065,China;schol of Science,Chongqing University of Technology,Chongqing 400050,China)

机构地区：[1]Department of Physics,Liaoning University,Shenyang 10036,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

出　　处：《Chinese Physics B》2023年第2期499-503,共5页中国物理B（英文版）

基　　金：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 S1state. 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 

分 类 号：O626[理学—有机化学] O641.1[理学—化学]