Abstract The relationships between the structure and the thermodynamic behavior and the hydrogen bond (HB) interactions in H2O + ionic liquid (IL) systems were systematically investigated for the first time. Imidazolium-based ILs comprising 1-alkyl-3-methylimidazolium cations ([RMIM]+) and various anions such as acetate ([AC]-), thiocyanate ([SCN]-), tetrafluoroborate ([BF4]-), and bis(trifluoromethylsulfonyl)imide ([Tf2N]-) were investigated. The vapor–liquid equilibrium (VLE) of H2O + IL systems was experimentally determined and predicted by the UNIFAC-Lei model. The results demonstrated that the vapor pressure is mainly dependent on the type of anion and increases slightly with an increase in the cation alkyl chain length. Quantum chemistry calculation and wavefunction analysis clearly revealed the relationship between the VLE and the HB interactions. This study provides theoretical guidance for designing and screening task-specific ILs for chemical processes such as gas dehydration and dehumidification.

中文翻译：

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结构对水-离子液体体系热力学行为和氢键相互作用的影响

摘要 首次系统地研究了H2O+离子液体(IL)体系中结构与热力学行为以及氢键(HB)相互作用之间的关系。基于咪唑鎓的离子液体包含 1-烷基-3-甲基咪唑鎓阳离子 ([RMIM]+) 和各种阴离子，例如乙酸盐 ([AC]-)、硫氰酸盐 ([SCN]-)、四氟硼酸盐 ([BF4]-) 和双研究了(三氟甲基磺酰基)亚胺([Tf 2 N]-)。H2O + IL 系统的汽液平衡 (VLE) 由 UNIFAC-Lei 模型通过实验确定和预测。结果表明，蒸气压主要取决于阴离子的类型，并随着阳离子烷基链长度的增加而略有增加。量子化学计算和波函数分析清楚地揭示了 VLE 和 HB 相互作用之间的关系。本研究为设计和筛选用于气体脱水和除湿等化学过程的特定任务 IL 提供了理论指导。