Premium
NMR Diffusion Measurements as a Simple Method to Examine Solvent–Solvent and Solvent–Solute Interactions in Mixtures of the Ionic Liquid [Bmim][N(SO 2 CF 3 ) 2 ] and Acetonitrile
Author(s) -
Keaveney Sinead T.,
Schaffarczyk McHale Karin S.,
Stranger James W.,
Ganbold Batchimeg,
Price William S.,
Harper Jason B.
Publication year - 2016
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201600927
Subject(s) - ionic liquid , acetonitrile , chemistry , solvent , diffusion , ionic bonding , inorganic chemistry , organic chemistry , ion , thermodynamics , physics , catalysis
The self‐diffusion coefficients of each component in mixtures of 1‐butyl‐3‐methylimidazolium bis (trifluoromethanesulfonyl)imide ([Bmim][N(SO 2 CF 3 ) 2 ]) and acetonitrile were determined. The results suggest that the hydrodynamic boundary conditions change from “stick” to “slip” as the solvent composition transitions from “ionic liquid dissolved in acetonitrile” ( χ IL <0.4) to “acetonitrile dissolved in ionic liquid” ( χ IL >0.4). At higher χ IL , the acetonitrile species are affected by “cage” and “jump” events, as the acetonitrile molecules reside nearer to the charged centre on the ions than in the “non‐polar” regions. The self‐diffusion coefficients of hexan‐1‐amine, dipropylamine, 1‐hexanol and dipropylether in mixtures of [Bmim][N(SO 2 CF 3 ) 2 ] and acetonitrile were determined. In general, the nitrogen‐containing solutes were found to diffuse slower than the oxygen‐containing solutes; this indicates that there are greater ionic liquid–N interactions than ionic liquid–O interactions. This work demonstrates that the self‐diffusion coefficients of species can provide valuable information about solvent–solvent and solvent–solute interactions in mixtures containing an ionic liquid.