The physicochemical, thermodynamic, spectroscopic, and electronic properties of α‐mangostin dye (1,3,6‐trihydroxy‐7‐methoxy‐2,8‐bis(3‐methyl‐2‐buten‐1‐yl)‐9H‐xanthen‐9‐one) were investigated. Five conformers of the α‐mangostin dye were obtained using three different polarizable continuum model (PCM)/density functional theory (DFT) methods: wB97XD/6‐31+G(d,p), M06‐2X/6‐31+G(d,p), and B3LYP/6‐31+G(d,p). The species distribution of the five conformers in acetonitrile, water, and the gas phase was derived from the Gibbs free energy changes of their interconversion equilibria. Three dominant conformers (Conformers 2, 3, and 4) were found as coexisting species in solvents. Chemical descriptors of the three dominant conformers of the α‐mangostin in acetonitrile and water were obtained. Simulated UV–Vis spectra of the existing conformers and their mixtures in acetonitrile and water derived from the PCM/TD‐DFT calculations were in good agreement with experimental results. Because the three dominant conformers of α‐mangostin absorb light in the UV region, the application of α‐mangostin dye for UV protection is suggested. The performance of the three dominant α‐mangostin conformers in dye sensitized solar cells was also investigated.

中文翻译：

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α-Mangostin构象异构体的存在以及非质子和质子溶剂对其平衡，UV-Vis光谱和化学描述符的影响：密度泛函理论和随时间变化的密度泛函理论研究

α-Mangostin染料（1,3,6-三羟基-7-甲氧基-2-2,8-双（3-甲基-2-丁烯-1-基）-9H-黄嘌呤的理化，热力学，光谱和电子性质‐9‐1）进行了调查。使用三种不同的极化连续体模型（PCM）/密度泛函理论（DFT）方法获得了五个构象的α-芒果蛋白染料：wB97XD / 6-31 + G（d，p），M06-2X / 6-31 + G （d，p）和B3LYP / 6-31 + G（d，p）。五个构象异构体在乙腈，水和气相中的物种分布是由相互转换平衡的吉布斯自由能变化得出的。三个优势构象（构象2，3和4被发现是在溶剂中共存的物种。获得了在乙腈和水中的α-Mangostin的三个主要构象异构体的化学描述符。从PCM / TD-DFT计算得出的现有构象异构体及其混合物在乙腈和水中的模拟UV-Vis光谱与实验结果非常吻合。由于α-Mangostin的三个主要构象异构体在紫外线区域吸收光，因此建议将α-Mangostin染料用于紫外线防护。还研究了染料敏化太阳能电池中三种主要的α-芒果素构象异构体的性能。