摘要
运用密度泛函(DFT)和含时密度泛函(TDDFT)计算方法研究了10-羟基苯并喹啉(HBQ)及其衍生物分子内质子转移过程,探究了取代基效应对质子转移过程的影响,研究发现,HBQ及其衍生物可以形成分子内氢键,且激发态时氢键增强.基态时各分子以醇式构型稳定存在,激发态时酮式构型为优势构象.各化合物的最大吸收峰和发射峰主要是电子从HOMO到LUMO之间的跃迁引起的.基态分子内质子转移(醇式→酮式)需要跃过较高的能垒因而难以发生,而激发态时只需跃过较低能垒就很容易发生分子内质子转移,吸电子基的引入可以使该过程的能垒降低,因此吸电子基有利于激发态质子转移.取代基效应影响化合物的光谱性质.
The intramolecular proton transfer processes of 10 -Hydroxybenzo [ h ] quinoline （HBQ） compounds have been studied by using DFT and TDDFT methods, and the substituent effects existed in the intramolecular proton transfer reactions have been explored. The calculated results show that HBQ compounds can form intramolecular hydrogen bonds, which can be significantly strengthened in the excited state. In the ground state, the enol form is the normal form, but the keto form is the normal form in the excited state. The maximum absorption peaks and emission peaks of each compound are mainly caused by the transition of electrons from HOMO to LU- MO. Because the GSIPT（ enol form→keto form） barrier is very high, the proton transfer process is hard to occur. However, in the excited state, there is only a low - barrier ESIPT curve for HBQ compounds, and the barrier decreases when the substituent is electron withdrawing, so the electron withdrawing substituent is in favor of ESIPT. Substituent effects affect the spectral properties of HBQ compounds.
出处
《原子与分子物理学报》
CAS
北大核心
2018年第1期13-20,共8页
Journal of Atomic and Molecular Physics
基金
国家自然科学基金(21172066
20971041)
湖南省高校科技创新团队项目(湘教通[2012]318)
