Deep‐eutectic solvents (DESs) are regarded as alternative green solvents to ionic liquids. In this work we report the structural properties and hydrogen bonding (H‐bonding) interactions of an aqueous DES system. The used DES, ethaline (ETH), is composed of choline chloride and ethylene glycol (EG) in 1 : 2 molar ratio. The investigations were carried out by FTIR spectroscopy combined with quantum chemical calculations. Excess spectroscopy and two‐dimensional correlation spectroscopy (2D‐COS) were used to explore the data in detail. The results showed that, upon mixing, ETH transforms to EG dimers and trimers and D₂O clusters transform to various ETH‐D₂O complexes. Theoretical calculations show that water molecules insert between the anion and cation of ETH, break the strong doubly ionic Cl^−…H−O_Ch+ H‐bond, share charges of the ions and form H‐bond with them, thus modulate the interaction properties of ETH. This study deepens our molecular‐level understanding of the system and would shed light on its applications.

中文翻译：

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水合对Ethaline深共晶溶剂的结构和相互作用的影响：光谱和计算研究。

深共熔溶剂（DES）被视为离子液体的替代绿色溶剂。在这项工作中，我们报告了水性DES系统的结构特性和氢键（H键）相互作用。所用的DES乙胺（ETH）由氯化胆碱和乙二醇（EG）以1：2的摩尔比组成。研究是通过FTIR光谱结合量子化学计算进行的。多余光谱和二维相关光谱（2D-COS）用于详细研究数据。结果表明，混合后，ETH转化为EG二聚体和三聚体，D ₂ O团簇转化为各种ETH-D ₂O配合物。理论计算表明，水分子插入ETH的阴离子和阳离子之间，打破强双重离子氯^{- ...} H-O _{CH +}氢键，离子和形式H-键与他们的共享电荷，从而调制的相互作用性质ETH。这项研究加深了我们对该系统的分子水平的了解，并将阐明其应用。