2-(Benzo[d]thiazol-2-yl)-3-methoxynaphthalen-1-ol (MMT) is one of the key materials for making naphthalene. Distinguishing photophysical phenomena of MMT were observed in different solvents [U. Warde and S. Nagaiyan, J. Photochem. Photobiol., A, 2017, 337, 33]. However, the solvent effect on the hydrogen bond dynamical process has not been carefully analyzed theoretically. Based on state-of-the-art ab initio calculations, we provide a molecular-level investigation where excited-state hydrogen bonds and proton transfers are affected by solvent polarity. The computed absorption and fluorescence emission spectra of MMT are in agreement with the experimental peak values. The calculated hydrogen bond parameters and infrared vibration spectra confirm the excited-state hydrogen bond enhancing mechanism and uncovered the intensity of the excited-state hydrogen bond weakening as a perfect solvent polarity augment. Importantly, Hirshfeld charges unveiled that the excited-state hydrogen bond strength depends on solvent effects and electronegativity of the proton donor and proton acceptor. Based on frontier molecular orbitals of MMT, we found that the degree of charge transfer gradually increased with an increase in solvent polarity. By analyzing the potential energy curves, we concluded that the excited state intramolecular proton transfer (ESIPT) reaction of MMT is gradually inhibited by increasing solvent polarity. Revealing the mechanism of solvent effects will help to develop new products in optoelectronics and analytical tools.

中文翻译：

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揭示溶剂的作用：2-（苯并[ d ]噻唑-2-基）-3-甲氧基萘-1-醇的 激发态氢键和质子转移

2-（苯并[ d ]噻唑-2-基）-3-甲氧基-1-醇（MMT）是用于使萘的关键材料之一。在不同的溶剂中观察到了MMT的光物理现象。Warde和S.Nagaiyan，J.Photochem 。光生物学。，A，2017，337，33]。但是，理论上没有仔细分析溶剂对氢键动力学过程的影响。基于最先进的从头算计算中，我们提供了分子水平的研究，其中激发态氢键和质子转移受溶剂极性的影响。MMT的计算吸收光谱和荧光发射光谱与实验峰值一致。计算得出的氢键参数和红外振动光谱证实了激发态氢键增强的机理，并揭示了作为理想溶剂极性增强剂的激发态氢键减弱的强度。重要的是，Hirshfeld电荷揭示出，激发态氢键强度取决于质子供体和质子受体的溶剂效应和电负性。基于MMT的前沿分子轨道，我们发现电荷转移的程度随着溶剂极性的增加而逐渐增加。通过分析势能曲线，我们得出结论，MMT的激发态分子内质子转移（ESIPT）反应受溶剂极性的增加逐渐抑制。揭示溶剂效应的机理将有助于开发光电和分析工具方面的新产品。