溶剂极性对1，5-二羟基蒽醌分子双质子转移过程的影响

具有激发态分子内双质子转移特性的分子在荧光传感器、激光材料、生物分子探针等领域具有广泛的应用. 羟基蒽醌作为蒽醌类化合物是自然界中广泛存在且具有质子转移特性的次级代谢物，其衍生物已被广泛研究并成功应用于染料、免疫增强和抗癌药物. 近年来，1，5-二羟基蒽醌(1，5-DHAQ)作为一种具有两个分子内氢键的羟基蒽醌衍生物受到了广泛的关注. 本文采用飞秒瞬态吸收光谱结合含时密度泛函理论方法研究了溶剂极性对1，5-DHAQ分子激发态分子内双质子转移过程的影响. 1，5-DHAQ分子在甲苯、四氢呋喃和乙腈溶剂中的稳态荧光光谱表明，溶剂极性的改变对1，5-DHAQ的荧光峰位置产生了影响. 瞬态吸收光谱表明，溶剂极性的增大加快了质子转移的速率. 超快动力学拟合结果表明，溶剂极性的增大有助于加快1，5-DHAQ分子中的激发态分子内双质子转移过程. 此外，通过理论计算得到的势能曲线分析表明质子转移的能垒随着溶剂极性的增加而逐渐减小，从而促进1，5-DHAQ分子激发态分子内双质子转移过程的发生，这进一步验证和解释了实验结果. 本工作有助于开发和合成更稳定、高效的羟基蒽醌衍生物.

Effect of Solvent Polarity on Excited-State Double Proton Transfer Process of 1,5-Dihydroxyanthraquinone

The excited-state double proton transfer (ESDPT) properties of 1,5-dihydroxyanthraquinone (1,5-DHAQ) in various solvents were investigated using femtosecond transient absorption spectroscopy and the DFT/TDDFT method. The steady-state fluorescence spectra in toluene, tetrahydrofuran (THF) and acetonitrile (ACN) solvents presented that the solvent polarity has an effect on the position of the ESDPT fluorescence emission peak for the 1,5-DHAQ system. Transient absorption spectra show that the increasing polarity of the solvent accelerates the rate of excited state dynamics. Calculated potential energy curves analysis further verified the experimental results. The ESDPT barrier decreases gradually with the increase of solvent polarity from toluene, THF to ACN solvent. It is convinced that the increase of solvent polarity can promote the occurrence of the ESDPT dynamic processes for the 1,5-DHAQ system. This work clarifies the mechanism of the influence of solvent polarity on the ESDPT process of 1,5-DHAQ, which provides novel ideas for design and synthesis of new hydroxyanthraquinone derivatives.