Skillfully tuning 1-hydroxy-9H-fluoren-9-one forward-backward ESIPT processes by introducing electron-withdrawing groups: A theoretical exploration
Skillfully tuning 1-hydroxy-9H-fluoren-9-one forward-backward ESIPT processes by introducing electron-withdrawing groups: A theoretical exploration
复制标题
通过引入吸电子基团巧妙调控1-羟基-9H-芴-9-酮前向-后向ESIPT过程：理论探索
DOI：
10.1016/j.molliq.2020.112627
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发表时间：
2020-04-01
影响因子：
6
通讯作者：
Shi, Ying
中科院分区：
文献类型：
--
作者：
Cao, Bifa;Han, Jianhui;Shi, Ying
合理地调节前向-后向激发态分子内质子转移（ESIPT）势垒可以有效地影响白色光的产生。利用1-羟基-9H-芴-9-酮（HHF）的ESIPT特性作为原型，引入两个吸电子取代基（硝基和甲酰基）。用密度泛函理论（DFT）和含时密度泛函理论（TDDFT）方法研究了吸电子基团对正向-反向ESIPT过程能垒的影响。前线分子轨道、红外光谱、非共价相互作用、静电势、电子光谱、分子结构等对我们的结果进行了交叉验证。这些结果表明，吸电子基团显着促进正向ESIPT过程的发生，阻碍反向ESIPT。势能曲线表明，正向ESIPT能垒由HHF（7.64 kcal/mol）明显降低到5.73 kcal/mol（FIHF-CHO）和4.55 kcal/mol（HHF-NO2）.同时，后向ESIPT能垒由HHF（2.51 kcal/mol）有效地提高到3.57 kcal/mol（HHF-CHO）和3.84 kcal/mol（HHF-NO2）。通过引入吸电子基团，有效地调节了正向-反向ESIPT的能垒。此外，还获得了更稳定和更好的白色荧光。我们的工作将有助于改善分子的ESIPT性能和开发白色发光分子。(C)2020 Elsevier B. V.保留所有权利。
Judiciously tuning the forward-backward excited state intramolecular proton transfer (ESIPT) barriers can effectively influence the generation of white light. Harnessing the 1-hydroxy-9H-fluoren-9-one (HHF) ESIPT characteristics as the prototype, two electron-withdrawing substituents (nitro group and formyl group) were introduced. The influence of electron-withdrawing group on the energy barrier of the forward-backward ESIPT processes has been studied by density functional theory (DFT) and time-dependent DFT (TDDFT) methods. The frontier molecular orbitals, infrared spectra, non-covalent interactions, electrostatic potential, electronic spectra, molecular structure have cross-validated our results. These results indicate that the electron-withdrawing groups dramatically promote the occurrence of the forward ESIPT process and hinder the backward ESIPT. The potential curves revealed that the forward ESIPT energy barrier was obviously reduced to 5.73 kcal/mol (FIHF-CHO) and 4.55 kcal/mol (HHF-NO2) compared with HHF (7.64 kcal/mol). Meanwhile, the backward ESIPT energy barrier is availably improved to 3.57 kcal/mol (HHF-CHO) and 3.84 kcal/mol (HHF-NO2) compared with HHF (2.51 kcal/mol). Through the introduction of the electron-withdrawing groups, the energy barrier of the forward-backward ESIPT is efficaciously modulated. Furthermore, the more stable and better white fluorescence has been achieved. Our work will be conducive to improve molecular ESIPT properties and exploit white luminescent molecules. (C) 2020 Elsevier B.V. All rights reserved.