Aggregation Promotes Excited-State Intramolecular Proton Transfer for Benzothiazole-Substituted Tetraphenylethylene Compound
Aggregation Promotes Excited-State Intramolecular Proton Transfer for Benzothiazole-Substituted Tetraphenylethylene Compound
复制标题
聚集促进苯并噻唑取代的四苯乙烯化合物的激发态分子内质子转移
DOI：
10.1021/acsabm.9b00818
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发表时间：
2019
影响因子：
4.7
通讯作者：
Zheng Yujun
中科院分区：
文献类型：
--
作者：
Zhao Jinfeng;Dong Hao;Yang Huan;Zheng Yujun
激发态分子内质子转移（ESIPT）结合聚集诱导增强发射（AIEE）为设计更高效的高发射材料提供了一条更好的途径。这些材料通常在生物化学传感领域表现出潜在的能力。本文主要研究了苯并噻唑取代四苯乙烯类化合物（BTZ-TPE-1a）在液相和固相中的ESIPT和AIEE机理。值得一提的是，BTZ-TPE-1a具有生物相容性，在细胞成像和细胞活力方面发挥着重要作用。由于其无毒和生物相容性，BTZ-TPE-1a是癌症生物医学成像的优秀成像剂。我们首先探索BTZ-TPE-1a系统的氢键相互作用。光激发导致的双氢键和分子内电荷转移（ICT）的增强揭示了ESIPT趋势。模拟电子光谱和势能面（PES）表明BTZ-TPE-1a分子的激发态分子内单质子转移（ESISPT）机理。相关的实验报告证实了我们的结果。通过从过渡态（TS）结构开始进行Born-Oppenheimer分子动力学（BOMD）模拟，我们可以进一步验证ESISPT机制。在固相方面，采用ONIOM模型实现了量子力学和分子力学（QM/MM）模拟，在此基础上阐述了BTZ-TPE-1a的AIEE机理。我们不仅说明了BTZ-TPE-1a的具体ESISPT机制并弥补了实验的不足，而且还提出了对ESIPT和AIEE在聚集状态（即，聚集促进BTZ-TPE-1a的ESIPT）。我们希望本工作能促进苯并噻唑取代四苯乙烯类化合物在生物医学和光电应用方面的进一步发展。
Excited-state intramolecular proton transfer (ESIPT) coupled to aggregation-induced enhanced emission (AIEE) offers a better route to design more efficient highly emissive materials. These materials usually present potential abilities in biochemical sensing fields. In this work, we mainly focus on ESIPT and AIEE mechanism for the benzothiazole-substituted tetraphenylethylene compound (BTZ-TPE-1a) in liquid and solid phases. It is worth mentioning that BTZ-TPE-1a is biocompatible in nature and plays important roles in cell imaging and cell viability. Given its nontoxicity and biocompatiblility properties, BTZ-TPE-1a is an excellent imaging agent in cancer biomedical imaging. We first explore hydrogen-bonding interactions for the BTZ-TPE-1a system. The strengthening dual hydrogen bonds and intramolecular charge transfer (ICT) resulting from photoexcitation reveals an ESIPT tendency. Simulated electronic spectra and potential energy surfaces (PESs) indicate the excited-state intramolecular single-proton-transfer (ESISPT) mechanism for BTZ-TPE-1a molecule. Related experimental reports confirm our results. By performing Born–Oppenheimer molecular dynamics (BOMD) simulations starting from a transition state (TS) structure, we can further verify the ESISPT mechanism. In the solid phase, quantum mechanics and molecular mechanics (QM/MM) simulation is realized in the ONIOM model, on the basis of which the AIEE mechanism of BTZ-TPE-1a is elaborated. We not only illustrate the specific ESISPT mechanism for BTZ-TPE-1a and compensate for the inadequacy of the experiment but also present direct insights into ESIPT and AIEE in the aggregation state (i.e., aggregation promotes ESIPT for BTZ-TPE-1a). We hope this work promotes further development of benzothiazole-substituted tetraphenylethylene compounds in biomedical and optoelectronic applications.