离子液体 1-乙基-3-甲基咪唑硫酸乙酯与水之间的氢键相互作用。
The hydrogen bonding interactions between the ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate and water.
机构信息
Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China.
出版信息
J Phys Chem B. 2010 Apr 15;114(14):4747-54. doi: 10.1021/jp1009498.
1-Ethyl-3-methylimidazolium ethyl sulfate (EMIES) is a novel ionic liquid with potential industrial applications. Attenuated total reflectance infrared spectroscopy, (1)H NMR spectroscopy, and quantum chemical calculations were employed to investigate the molecular interactions between water and EMIES. The infrared spectra were analyzed by two methods: excess spectroscopy and two-dimensional correlation spectroscopy. This showed that the hydrogen bond involving the -SO(3) group in the ethyl sulfate anion (ES) was enhanced, while those involving the aromatic C-H groups of 1-ethyl-3-methylimidazolium cation (EMI) were weakened in the presence of water. During the process of increasing water concentration, the hydrogen bonding interaction between H(2)O and SO is prior to that between H(2)O and the C-H group on the imidazolium ring. At low concentrations, water interacts selectively with -SO(3) in the ethyl sulfate anion, while, at high concentrations (mole fraction of water equal or greater than 0.6), it can also form hydrogen bonds directly with the imidazolium ring. The following sequential order of interaction strength is established: EMI-water-ES > EMI-ES > ES-water > EMI-water.
1-乙基-3-甲基咪唑硫酸乙酯（EMIES）是一种具有潜在工业应用的新型离子液体。采用衰减全反射红外光谱（ATR-IR）、（1）H 核磁共振光谱（1H NMR）和量子化学计算研究了水与 EMIES 之间的分子相互作用。通过两种方法对红外光谱进行了分析：过量光谱法和二维相关光谱法。结果表明，在水的存在下，硫酸乙酯阴离子（ES）中涉及-SO3 基团的氢键增强，而涉及 1-乙基-3-甲基咪唑阳离子（EMI）中芳族 C-H 基团的氢键减弱。在增加水浓度的过程中，H2O 与 SO 之间的氢键相互作用优先于 H2O 与咪唑环上的 C-H 基团之间的氢键相互作用。在低浓度时，水选择性地与硫酸乙酯阴离子中的-SO3 相互作用，而在高浓度（水的摩尔分数等于或大于 0.6）时，它也可以直接与咪唑环形成氢键。建立了以下相互作用强度的顺序：EMI-水-ES＞EMI-ES＞ES-水＞EMI-水。
Zotero 插件