物理化学学报 >> 2014, Vol. 30 >> Issue (9): 1605-1610.doi: 10.3866/PKU.WHXB201407012

热力学,动力学和结构化学 上一篇    下一篇

离子液体1-乙基-3-甲基咪唑三氟甲基磺酸盐与水之间的氢键作用

宋大勇1,2, 陈静1   

  1. 1. 中国科学院兰州化学物理研究所, 羰基合成与选择氧化国家重点实验室, 兰州 730000;
    2. 中国科学院大学, 北京 100049
  • 收稿日期:2014-05-21 修回日期:2014-06-30 发布日期:2014-08-29
  • 通讯作者: 陈静 E-mail:chenj@licp.cas.cn
  • 基金资助:

    国家重点基础研究发展规划项目(973)(2011CB201404)和国家自然科学基金(21133011)资助

Hydrogen-Bonding Interactions between Ionic Liquid 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate and Water

SONG Da-Yong1,2, CHEN Jing1   

  1. 1. State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu Province, P. R. China;
    2. University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2014-05-21 Revised:2014-06-30 Published:2014-08-29
  • Contact: CHEN Jing E-mail:chenj@licp.cas.cn
  • Supported by:

    The project was supported by the National Key Basic Research Program of China (973) (2011CB201404) and National Natural Science Foundation of China (21133011).

摘要:

通过衰减全反射红外(ATR-IR)光谱、二维红外相关谱结合量子化学计算研究了1-乙基-3-甲基咪唑三氟甲基磺酸盐([emim][OTf])和水之间的氢键作用. 结果表明,在[emim][OTf]-水体系中,当水的浓度较低时(0.1< x(D2O)< 0.3),水分子的主要存在形式是包裹在离子液体中的没有缔合的单体. 水分子优先填充到[emim][OTf]的空隙中,并且与[emim][OTf]的阴离子形成“[OTf]-…HOH…[OTf]-”结构,水分子与[emim][OTf]的阳离子的相互作用位点是烷基氢而不是芳香氢;当水分子浓度较高时,水分子倾向于自身缔合形成小团簇结构,水分子与[emim][OTf]的阳离子的相互作用位点是芳香氢而不是烷基氢.

关键词: 离子液体, 氢键相互作用, 衰减全反射红外光谱, 二维红外相关谱

Abstract:

Attenuated total reflectance infrared (ATR-IR) spectroscopy, two- dimensional correlation spectroscopy, and quantum chemical calculations were used to elucidate the hydrogen-bonding interactions between an ionic liquid (IL), namely 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][OTf]), and water over a wide concentration range. It was found that water molecules are isolated from each other and embedded in the IL environment at low water concentrations (0.1<x(D2O)< 0.3). The water molecules occupy the IL interstices, and one water molecule forms two hydrogen bonds, with two [OTf]- anions."[OTf]-…HOH… [OTf]-"hydrogen-bonded complexes exist in the [emim][OTf]- water system. In this concentration range, the hydrogen-bonding interaction sites between the cation and water is the alkyl C―H rather than the aromatic C―H. At higher water concentrations, the water molecules form hydrogen bonds with themselves, producing water clusters in the mixture. The hydrogen-bonding interaction site between the cation and water is the aromatic C―H rather than the alkyl C―H.

Key words: Ionic liquid, Hydrogen bonding interaction, Attenuated total reflectance infrared spectroscopy, Two-dimensional correlation spectroscopy

MSC2000: 

  • O645