The two-pronged approach of heteroatoms and substituents to achieve a synergistic regulation of the ESIPT process in amino 2-(2'-hydroxyphenyl)benzoxazole derivatives.
The two-pronged approach of heteroatoms and substituents to achieve a synergistic regulation of the ESIPT process in amino 2-(2'-hydroxyphenyl)benzoxazole derivatives.
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DOI：
10.1016/j.saa.2023.122318
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发表时间：
2023-01
期刊：
影响因子：
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通讯作者：
Yu Feng;Xindi Huang;Meiheng Lv;Yan Yu;Gaoshang Jiang;Haixiang He;Jianyong Liu
中科院分区：
文献类型：
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作者：
Yu Feng;Xindi Huang;Meiheng Lv;Yan Yu;Gaoshang Jiang;Haixiang He;Jianyong Liu
氨基2-(2‘-羟基苯基)苯并唑衍生物是一类具有优良光物理性质的分子。其中大部分可通过激发态分子内质子转移(ESIPT)过程用作荧光探针。在这项工作中，我们重点研究了杂原子(O，S)和取代基(乙酰丙酮，氢)在衍生物中的作用。用DFT/TDDFT方法结合B3LYP-D3BJ泛函，计算得到的吸收峰和发射峰与实验数据吻合较好。结构优化、红外光谱和密度梯度分析的结果表明，这些分子中存在S1态的电子自旋互穿转变过程，这也间接说明了杂原子S大于O，取代基乙酰丙酮大于氢具有较强的氢键。质子转移(PT)势能曲线(PECS)定性地表明，杂原子S比O更容易引发ESIPT，取代基乙酰丙酮比氢更容易引发ESIPT。在杂原子S和乙酰丙酮取代基同时堆积的共同影响下，PT过程的能垒可以有效降低，实现了协同策略，这对荧光材料的设计具有一定的指导意义。
Amino 2-(2′-hydroxyphenyl)benzazole derivatives are a class of molecules with excellent photophysical properties. Most of them can be applied as a fluorescent probe via the excited-state intramolecular proton transfer (ESIPT) process. In this work, we focus on the effects of heteroatoms (O, S) and substituents (acetylacetone, hydrogen) in the derivatives. Using DFT/TDDFT methods with the B3LYP-D3BJ functionals, the absorption and emission peaks are in good agreement with the experimental data. Results of optimized structures, infrared vibrational spectra, and reduced density gradient present the existence of the ESIPT process in the S1state in these molecules, it also indirectly shows that the heteroatom S is more than O, and the substituent acetylacetone is more than hydrogen has stronger hydrogen bonds. The proton transfer (PT) potential energy curves (PECs) qualitatively show that it is easier for the heteroatom S to induce ESIPT than that of O. The same for the substituent acetylacetone than that of hydrogen. Under the joint influence of the simultaneous stacking of heteroatom S and acetylacetone substituent, the energy barrier of the PT process can be effectively lowered, realizing a synergistic strategy, which can provide some guidance for the design of fluorescent materials.