期刊
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
卷 11, 期 14, 页码 2452-2458出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/b815835e
关键词
-
资金
- Australian Research Council
- DRM
According to dielectric spectroscopy measurements, ionic liquids (ILs) have rather modest dielectric constants that reflect contributions from distortion and electronic polarization caused by the molecular polarizability as well as the orientation polarization caused by the permanent dipole moment of the ions. To understand the relative importance of these various contributions, the electronic polarizabilities of 27 routinely used ionic liquid ions of different symmetry and size were calculated using ab initio-based methods such as HF and MP2. Using the Clausius-Mossotti equation, these polarizabilities were then used to obtain the electronic polarization contribution (epsilon(op)) to the dielectric constants of six ionic liquids, [C(2)mim][BF4], [C(2)mpyr][N(CN)(2)], [C(2)mim][CF3SO3], [EtNH3][NO3], [C(2)mim][NTf2] and [C(2)mim][EtSO4]. Theoretical epsilon(op) values were compared to experimental refractive indices of these ionic liquids as well as to those of traditional molecular solvents such as water, tetrahydrofuran (THF), dimethylsulfoxide (DMSO) and formamide. The dipole moments of the ions were also calculated, and from these it is shown that the molecular reorientation component of the dielectric constants of the ionic liquids consisting of ions with small or negligible dipole moments is quite small. Thus it is concluded that a contribution from a form of ionic polarization must be present.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据