Microscopic Solvation Structure of Glucose in 1-Ethyl-3-methylimidazolium Methylphosphonate Ionic Liquid
Microscopic Solvation Structure of Glucose in 1-Ethyl-3-methylimidazolium Methylphosphonate Ionic Liquid
复制标题
1-乙基-3-甲基咪唑甲基膦酸离子液体中葡萄糖的微观溶剂化结构
DOI：
10.1021/acs.jpcb.5b00724
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发表时间：
2015
期刊：
影响因子：
3.3
通讯作者：
and M. Shibayama.
中科院分区：
文献类型：
--
作者：
K. Hirosawa;K. Fujii *;K. Hashimoto;Y. Umebayashi;and M. Shibayama.
利用高能X射线衍射（HEXRD）实验和分子动力学（MD）模拟研究了葡萄糖在1-乙基-3-甲基咪唑甲基膦酸盐、[C2mIm +][CH 3（H）PO 3-]离子液体中的溶剂化结构以及纯[C2mIm+][CH 3（H）PO 3-]的液体结构.在纯[C2mIm+][CH 3（H）PO 3-]中，发现了阳离子和阴离子之间的特殊相互作用，即CH 3（H）PO 3-中的氧原子与C2mIm+中C2位的氢形成氢键。在葡萄糖/[C2 mIm +][CH 3（H）PO 3-]溶液中，实验径向分布函数在2.6 Å处观察到明显的峰，并且随着葡萄糖浓度的增加而增强。分子动力学模拟发现，该峰起源于葡萄糖与[C2mIm+][CH 3（H）PO 3-]中阴离子的最近邻分子间相互作用。由分子动力学结果导出的原子-原子对关联函数表明，葡萄糖的羟基与CH_3（H）PO_3-中的氧原子通过氢键相互作用。在葡萄糖分子中，分子间氢键与分子内氢键共存。我们的结论是，葡萄糖是容易形成的氢键与极性的CH 3（H）PO 3阴离子，但在离子液体中，葡萄糖的分子内氢键的断裂是不够的。
The solvation structure of glucose in 1-ethyl-3-methylimidazolium methylphosphonate, [C2mIm+][CH3(H)PO3–] ionic liquid and the liquid structure of the neat [C2mIm+][CH3(H)PO3–] were investigated by high-energy X-ray diffraction (HEXRD) experiments with the aid of molecular dynamics (MD) simulations. In neat [C2mIm+][CH3(H)PO3–], a specific interaction between the cation and anion is found, that is, the oxygen atoms within CH3(H)PO3–are hydrogen bonded with the hydrogen of the C2 position within C2mIm+. In glucose/[C2mIm+][CH3(H)PO3–] solutions, a significant peak is observed at 2.6 Å in experimental radial distribution functions and is enhanced with increasing glucose concentration. It is found from MD simulations that the peak originated from the nearest-neighbor intermolecular interaction between glucose and the anion in [C2mIm+][CH3(H)PO3–]. The atom–atom pair correlation function derived from MD results shows that hydroxyl groups of glucose interact with oxygen atoms within CH3(H)PO3–through the hydrogen bonds. The intermolecular hydrogen bonds coexist with the intramolecular hydrogen bond in a glucose molecule. We conclude that glucose is easy to form a hydrogen bond with a polar CH3(H)PO3anion; however, rupture of intramolecular hydrogen bonds within glucose is not enough in the ionic liquid.