Li Xiaoxiao, Wang Qiujie, Song Liying, Zhao Jinfeng, Jin Bing
Institute of Molecular Sciences and Engineering, Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao 266237, China; State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China.
Institute of Molecular Sciences and Engineering, Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao 266237, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Oct 15;279:121377. doi: 10.1016/j.saa.2022.121377. Epub 2022 May 12.
The excited-state proton transfer (ESIPT) behavior of organic fluorophores has been of great interest due to their unique photophysical properties. In this work, we have focused on the excited state kinetic behavior of four Schiff base organic molecules (i.e. CPMP, CPMMP, CPMDP, and CPMN) in acetonitrile solvents. The electron-donating of substituents and conjugation effects on the photophysical properties and ESIPT process of the Schiff base derivatives are investigated by theoretical methods. The results show that the hydrogen bonds are all enhanced in the excited states, which could provide the impetus for the ESIPT process. To further reveal the reaction process of ESIPT, we have scanned the potential energy curves of the ESIPT process and compared the potential barriers. It is found that the stronger the substituents give electrons and the conjugation effects the more favorable the excited state proton transfer (ESIPT). In the meantime, this study paves the way for the development of new Schiff base materials based on ESIPT.
由于其独特的光物理性质，有机荧光团的激发态质子转移（ESIPT）行为一直备受关注。在这项工作中，我们聚焦于四种席夫碱有机分子（即CPMP、CPMMP、CPMDP和CPMN）在乙腈溶剂中的激发态动力学行为。通过理论方法研究了取代基的给电子作用以及共轭效应对席夫碱衍生物光物理性质和ESIPT过程的影响。结果表明，氢键在激发态均得到增强，这可为ESIPT过程提供动力。为了进一步揭示ESIPT的反应过程，我们扫描了ESIPT过程的势能曲线并比较了势垒。发现取代基给电子能力越强以及共轭效应越强，激发态质子转移（ESIPT）越有利。同时，本研究为基于ESIPT的新型席夫碱材料的开发铺平了道路。
