文献类型：期刊文献

英文题名：Microscopic structures of ionic liquids 1-ethyl-3-methylimidazolium tetrafluoroborate in water probed by the relative chemical shift

作者：Xu YingJie[1,2];Gao Yan[1];Zhang LiQun[1];Yao Jia[1];Wang CongMin[1];Li HaoRan[1]

机构：[1]Zhejiang Univ, Dept Chem, Hangzhou 310027, Zhejiang, Peoples R China;[2]Shaoxing Univ, Dept Chem, Shaoxing 312000, Peoples R China

年份：2010

卷号：53

期号：7

起止页码：1561

外文期刊名：SCIENCE CHINA-CHEMISTRY

收录：SCI-EXPANDED(收录号：WOS:000280481500018)、、EI(收录号：20103313156014)、Scopus(收录号：2-s2.0-77955520617)、WOS

基金：The authors express their great thanks for the support from the National Natural Science Foundation of China (20773109 & 20704035) and the Natural Science Foundation of Zhejiang Province (Y4090453).

语种：英文

外文关键词：ionic liquids; H-1 NMR; microscopic structure; relative chemical shifts; 1-ethyl-3-methyl-imidazolium tetrafluoroborate

外文摘要：The relative chemical shifts (Delta delta) were put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF(4)) during the dilution process with water. The concentration-dependent Delta delta((C2)H-(C4)H), Delta delta((C2)H-(C5)H) and Delta delta((C4)H-(C5)H) were analyzed. The results reveal that the variations of the microscopic structures of three aromatic protons are inconsistent. The strength of the H-bond between water and three aromatic protons follows the order: (C2)H center dot center dot center dot O > (C4)H center dot center dot center dot O > (C5)H center dot center dot center dot O. The concentration-dependent Delta delta((C6)H-(C7)H) and Delta delta((C6)H-(C8)H) indicate the formation of the H-bonds of (Calkyl)H center dot center dot center dot O is impossible, and more water is located around (C6)H than around (C7)H or (C8)H. The concentration-dependent Delta delta((C2)H-(C4)H) and Delta delta((C2)H-(C5)H) both increase rapidly when x(water) > 0.9 or so, suggesting the ionic pairs of EmimBF(4) are dissociated rapidly. The turning points of concentration-dependent Delta delta((C2)H-(C4)H) and Delta delta((C2)H-(C5)H) indicate that some physical properties of the EmimBF(4)/water mixtures also change at the corresponding concentration point. The microscopic structures of EmimBF(4) in water could be clearly detected by the relative chemical shifts.