Yin Yingrui, Chen Zuzhi, Zhang Dan, Yang Lujia, Wang Mingli, Yang Yunfan
Opt Lett. 2024 Aug 1;49(15):4190-4193. doi: 10.1364/OL.532228.
The study of salicylideneaniline (SA) and its derivatives is critical due to their special photophysical properties and environmental sensitivity. In this work, the density time-dependent functional theory (TDDFT) and complete-active-space self-consistent-field (CASSCF) methods were carried out to calculate the substituent effect on excited-state properties and dynamics of SA derivatives. We found the para-substitution triggers the excited-state intramolecular proton transfer (ESIPT) reaction, exhibiting the dual-fluorescent phenomena. However, the meta- and ortho-substitutions impel the non-radiative transition process along the minimum energy conical intersection (MECI), forming the twisted intramolecular charge transfer (TICT) state to prevent ESIPT. This investigation of substituent effects on the photochemical processes and photophysical properties will provide the benchmarks for the design of fluorescent materials.
由于水杨醛苯胺（SA）及其衍生物具有特殊的光物理性质和环境敏感性，对其进行研究至关重要。在这项工作中，采用密度泛函含时理论（TDDFT）和完全活性空间自洽场（CASSCF）方法来计算取代基对SA衍生物激发态性质和动力学的影响。我们发现对位取代引发了激发态分子内质子转移（ESIPT）反应，呈现出双荧光现象。然而，间位和邻位取代促使沿着最低能量锥形交叉点（MECI）发生非辐射跃迁过程，形成扭曲分子内电荷转移（TICT）态以阻止ESIPT。这项关于取代基对光化学过程和光物理性质影响的研究将为荧光材料的设计提供基准。
