Abstract：
Aiming at shedding light on the molecular interactions in deep eutectic solvents (DESs), the DESs based on tetrabutylammonium bromide (TBAB) as hydrogen bond acceptor (HBA) and carboxylic acids (CAs) (formic acid (FA), oxalic acid (OA), and malonic acid (MA)) as hydrogen bond donor (HBD) were investigated by both experimental and theoretical techniques. The thermal behaviors of the prepared DESs were investigated by differential scanning calorimetry (DSC) method. In order to study the hydrogen bond formation between the DESs constituents, the FT-IR analysis was carried out. The large positive deviations of the iso solvent activity lines of ternary HBA + HBD + 2-propanol mixtures determined by the isopiestic technique from the semi-ideal behavior indicate that CAs interact strongly with TBAB and therefore they can form DESs. Molecular dynamics (MD) simulations were performed to present an atomic-scale image of the components and describe the microstructure of DESs. From the MD simulations, the radial distribution functions (RDFs), coordination numbers (CNs), combined distribution functions (CDFs), and spatial distribution functions (SDFs) were calculated to investigate the interaction between the components and three-dimensional visualization of the DESs. The obtained results confirmed the importance of hydrogen bonds in the formation of TBAB/CAs DESs.
摘要：
为了揭示低共熔溶剂(DES)中的分子相互作用，基于四丁基溴化铵（TBAB）作为氢键受体（HBA）和羧酸（CA）（甲酸（FA），草酸（OA），通过实验和理论技术研究了丙二酸（MA））作为氢键供体（HBD）。通过差示扫描量热法（DSC）研究了制备的DES的热行为。为了研究DES成分之间的氢键形成，进行FT-IR分析。通过同位技术确定的三元HBAHBD2-丙醇混合物的异溶剂活性线与半理想行为的正偏差较大，表明CA与TBAB相互作用强烈，因此它们可以形成DES。进行了分子动力学（MD）模拟，以显示组件的原子级图像并描述DES的微观结构。从MD模拟来看，径向分布函数(RDF)，协调号(CN)，组合分布函数(CDF)，和空间分布函数（SDF）进行了计算，以研究组件之间的相互作用和DES的三维可视化。获得的结果证实了氢键在TBAB/CAsDES形成中的重要性。
