Liquid Structure of the Ionic Liquid, 1-Methyl-4-cyanopyridinium Bis{(trifluoromethyl)sulfonyl}imide Determined from Neutron Scattering and Molecular Dynamics Simulations

Abstract

The liquid structure of 1-methyl-4-cyanopyridinium bis{(trifluoromethyl)sulfonyl}imide, a prototypical ionic liquid containing an electron-withdrawing group on the cation, has been investigated at 368 K. Experimental neutron scattering combined with empirical potential structure refinement analysis of the data and classical molecular dynamics simulations have been used to probe the liquid structure in detail. Both techniques generated highly consistent results that provide valuable validation of the force fields and refinement approaches. A significant degree of apparent charge ordering is found in the liquid structure, although the nonspherical shape of the ions results in interpenetration of cations into the first shell of adjacent cations, with much shorter closest contact distances than the averaged center-of-mass cation-cation and cation-anion separations.

Determination of the Activity of 1-Methyl-3-octylimidazolium Bis(trifluoromethanesulfonyl)amide in Binary Ionic Liquids from the Solubility in Water

“…However, a closer look at the variation of γ C 8 mimC 1 C 1 N IL with x C 8 mimC 1 C 1 N IL strongly suggests that the solvation environment around C 8 mim + considerably changes at the composition x C 8 mimC 1 C 1 N IL ≈ 0.3, where the phase transition presumably takes place. This may be taken as an example of the observation that changes in the structure of the microheterogeneity, which seems to be a common feature of many ILs, [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63] can affect the thermodynamic properties of binary ILs. …”

Applying neutron diffraction with isotopic substitution to the structure and proton-transport pathways in protic imidazolium bis{(trifluoromethyl)sulfonyl}imide ionic liquids

“…Within the EPSR simulations the [NTf 2 ] -anion was modelled as previously described 31 with no pre-constrained dihedral angles or restrictions to rotation. Simulations were equilibrated over ca.…”

Mutual Solubility of Hydrophobic Ionic Liquids and Water in Liquid-Liquid Two-phase Systems for Analytical Chemistry

“…This seems to be in harmony with the spatial heterogeneity in the structure of ILs. [229][230][231] The aggregation of the alkyl moiety of [Cnmim + ] would promote the association of water molecules. 232 Notable in Fig.…”