Exploration and elaboration of photo-induced proton transfer dynamical mechanism for novel 2-[1,3]dithian-2-yl-6-(7aH-indol-2-yl)-phenol sensor

作     者：Lei Xu Tian-Jie Zhang Qiao-Li Zhang Da-Peng Yang 许磊;张天杰;张巧丽;杨大鹏

作者机构：School of Physics and ElectronicsNorth China University of Water Resources and Electronic PowerZhengzhou 450046China Collaborative Innovation Center of Light Manipulations and ApplicationsShandong Normal UniversityJinan 250358China 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2020年第29卷第5期

页      面：208-213页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 080202[工学-机械电子工程] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0802[工学-机械工程] 0703[理学-化学] 

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.11574083) 

主　　题：intramolecular charge transfer ESIPT molecular electrostatic potential potential energy curves 

摘      要：In this work, we theoretically probe into the photo-induced hydrogen bonding effects between S0 state and S1 state as well as the excited state intramolecular proton transfer(ESIPT) behavior for a novel 2-[1,3]dithian-2-yl-6-(7aH-indol-2-yl)-phenol(DIP) probe system. We first study the ground-state hydrogen bonding O–H··· N behavior for DIP. Then we analyze the primary geometrical parameters(i.e., bond length, bond angle, and infrared(IR) stretching vibrational mode)involved in hydrogen bond, and confirm that the O–H··· N of DIP should be strengthened in the first excited state. It is the significant prerequisite for ESIPT reaction. Combining the frontier molecular orbitals(MOs) with vertical excitation analyses, the intramolecular charge transfer(ICT) phenomenon can be found for the DIP system, which reveals that the charge redistribution facilitates ESIPT behavior. By constructing potential energy curves for DIP along the ESIPT reactional orientation, we obtain quite a small energy barrier(3.33 kcal/mol) and affirmed that the DIP molecule undergoes ultrafast ESIPT process once it is excited to the S1 state and quickly transfers its proton, forming DIP-keto tautomer. That is why no fluorescence of DIP can be observed in experiment, which further reveals the ultrafast ESIPT mechanism proposed in this work.