Journal
JOURNAL OF PHYSICAL CHEMISTRY B
Volume 117, Issue 41, Pages 12556-12566Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jp405341m
Keywords
-
Categories
Funding
- Center for Research Computing at Notre Dame
- NSF [CBET-1134238]
- Div Of Chem, Bioeng, Env, & Transp Sys
- Directorate For Engineering [1134238] Funding Source: National Science Foundation
Ask authors/readers for more resources
Molecular dynamics simulations were performed for aqueous solutions of five ionic liquids (ILs): 1-ethyl-3-methylimidazolium ([C(2)mirn]) bis-(trifluoromethanesulfonyl) imide ([NTf2]), 1-n-butyl-3-methylimidazolium ([C(4)mim]) [NTf2], 1-n-heryl-3-methylimidazolium ([C(6)mim]) [NTf2], [C(2)mim] ethylsulfate ([C2H5SO4]), and [C(2)mim] chloride (Cl) to determine whether the ions of these ILs are associated at relatively high dilutions and whether the association is governed by hydrophobicity/hydrophilicity of the ILs. The adaptive biasing force technique was applied to calculate the potential of mean force (PMF) for each IL ion pair. For all of the ILs, the PMF is characterized by two distinct contact minima in which the ions have different relative conformations. The hydrophobic ILs bearing the anion [NTf2](-) exist predominantly in the associative state; the strength of the association of these ILs increases with increase in the alkyl chain length. The most hydrophilic IL [C(2)mim] Cl was determined to be almost fully dissociated at the concentration examined in the study. [C(2)mim] [C2H5SO4] showed hydration behavior that was intermediate between that exhibited by the ILs in which the anion is substituted with either Cl- or [NTf2](-) paired with [C(2)mim]. Association constants for these ILs were also computed. Radial distribution functions calculated by constraining the ions at the contact minima showed that hydration of the anion plays the dominant role in determining the microscopic behavior of these ILs in aqueous solutions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available