Liquid-Phase Structure of Dialkylimidazolium Ionic Liquids from Computer Simulations

Abstract

We present a detailed computational study of the structure of ionic liquids based on the imidazolium cation. Both imidazolium-ring stacking and hydrogen bonding behavior are investigated from radial and spatial orientational distribution functions, as well as orientational correlation functions. The alkyl chain size and anion effect on the liquid structure are provided and discussed. Our results support models for liquid organization comparable to those formulated on the basis of experimental observations.

How ideal are binary mixtures of room-temperature ionic liquids?

“…Recently, de Andrade et al [50] performed a detailed analysis of the structure of liquid [emim] [BF 4 ]. According to these simulations the local environment of the cations is characterized by the stacking of [emim] + in the z-direction perpendicular to the imidazolium rings, whereas the counterions are located in the equatorial planes.…”

Correlation between Dynamic Heterogeneity and Local Structure in a Room‐Temperature Ionic Liquid: A Molecular Dynamics Study of [bmim][PF6]

“…They interpreted the a relaxation to arise possibly from librations of the cations and a slower, sub-a relaxation to arise from relaxation of stacked cation rings. [19] Ludwig et al have carried out FTIR and NMR experiments as well as density functional theory (DFT)-based calculations on the IL [C 2 mim][NTf 2 ] (mim = methylimidazolium; [NTf 2 ] = bis(trifluoromethylsulfonyl)-imide) to study the dynamics of the cation-anion hydrogen bond. [7,20] Moreover, they also studied the validity of StokesEinstein (SE) and Stokes-Einstein-Debye (SED) relations using molecular dynamics (MD) simulations, [21] and found that both the SE and SED relations do not hold good for [C 2 mim][NTf 2 ].…”

Entanglement network of agarose in various solvents

“…It has been proposed that ionic liquids form three-dimensional structures even in the liquid state because of cation-anion hydrogen bonding and cation-cation ring stacking. [11][12][13] The threedimensional structure may contribute to the modulus of the solutions; if the elasticity due to the network of solvent molecules contributes to the plateau modulus (G N 0 ), then M e,melt is reduced. The aim of this study is to clarify whether or not the network formed by the ionic liquid molecules contributes to G N 0 .…”