A DFT/TDDFT study of the excited state intramolecular proton transfer based sensing mechanism for the aqueous fluoride chemosensor BTTPB
A DFT/TDDFT study of the excited state intramolecular proton transfer based sensing mechanism for the aqueous fluoride chemosensor BTTPB
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基于激发态分子内质子转移的水性氟化物化学传感器 BTPPB 传感机制的 DFT/TDDFT 研究
DOI：
10.1039/c3ra44900a
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发表时间：
2014-01-01
期刊：
影响因子：
3.9
通讯作者：
Chu, Tian-Shu
中科院分区：
文献类型：
--
作者：
Chen, Jun-Sheng;Zhou, Pan-Wang;Chu, Tian-Shu
采用密度泛函理论（DFT）/时间分辨傅立叶变换（TDDFT）方法研究了N-（3-（苯并[d]噻唑-2-基）-4-（叔丁基二苯基硅氧基）苯基）-苯甲酰胺（BTTPB）水溶液氟离子化学传感器的传感机理.具有17.6 kcal mol−1的中等跃迁势垒的脱甲硅烷基化反应和脱甲硅烷基化反应产物（3-BTHPB）的激发态分子内质子转移（ESIPT）一起用于荧光传感机制。优化的3-BTHPB（烯醇式）和3-BTHPB-e（酮式）构型在S 0和S1态上的势能曲线表明，ESIPT是一个低势垒过程（0.1 kcal mol−1），优化构型的能量表明ESIPT过程是放热的。计算的基态和第一单重激发态的垂直激发能与实验的紫外-可见吸收光谱和荧光发射光谱吻合较好。
The sensing mechanism of the aqueous fluoride chemosensor N-(3-(benzo[d]thiazol-2-yl)-4-(tert-butyldiphenyl silyloxy)phenyl)-benzamide (BTTPB) has been studied in detail by DFT/TDDFT methods. The desilylation reaction which has a moderate transition barrier of 17.6 kcal mol−1 and the excited state intramolecular proton transfer (ESIPT) of the desilylation reaction product (3-BTHPB) work together for the fluorescent sensing mechanism. The constructed potential energy curves among the optimized 3-BTHPB (enol form) and 3-BTHPB-e (keto form) geometries on the S0 and S1 states, indicated that the ESIPT is a low barrier process (0.1 kcal mol−1), and the energies of the optimized geometries showed that the ESIPT process is exothermic. The calculated vertical excitation energies in the ground state and the first singlet excited state reproduced the experimental UV-Vis absorbance and fluorescence emission spectra well.