NMR evidence of hydrogen bonding in 1-ethyl-3-methylimidazolium-tetrafluoroborate room temperature ionic liquid

被引：158

作者：

Huang, JF ^{[1
]}

Chen, PY ^{[1
]}

Sun, IW ^{[1
]}

Wang, SP ^{[1
]}

机构：

[1] Natl Cheng Kung Univ, Dept Chem, Tainan 70101, Taiwan

来源：

INORGANICA CHIMICA ACTA | 2001年 / 320卷 / 1-2期

关键词：

hydrogen bonding; ionic liquids; phase transitions;

D O I：

10.1016/S0020-1693(01)00477-7

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The 1-ethyl-3-methylimidazolium-tetrafluoroborate (EMI-BF4) room temperature ionic liquid was investigated with NMR techniques. Diffusion coefficients measured at temperatures ranging from 300 to 360 K indicate that phase-change occurred in the vicinity of 333 K, which is supported by B-11 quadrupolar relaxation rates. This phase change is ascribed to the transformation of the diffusion particle from 'discrete ion-pair' to 'individual ion' at temperatures above 335 K due to decomposition of the EMI-BF4, ion pair. Analysis of the C-13 dipole-dipole relaxation rates identifies the formation of hydrogen bond (C2H . . .F) between the counterions, EMI+ and BF4-. This hydrogen bonding may have significant contribution to the higher viscosity of this ionic liquid in comparison with the EMI-AlCl4 ionic liquid at corresponding temperatures. (C) 2001 Elsevier Science B.V. All rights reserved.

引用

页码：7 / 11

页数：5

共 30 条

[1] UPON THE STRUCTURE OF ROOM-TEMPERATURE HALOGENOALUMINATE IONIC LIQUIDS [J].