title: A molecular dynamics study of the ionic liquid, choline acetate.
abstract: Structural and dynamic properties of the ionic liquid (IL) choline acetate are studied using molecular dynamics (MD) simulations. The hydroxyl group of choline shows significant hydrogen-bonding interactions with the oxygen atoms of acetate. Nearly all choline cations are found to form a hydrogen bond with acetate anions at 400 K, while about 67% of cations participate in hydrogen-bonding interactions at 600 K. At 400 K, subdiffusive and prominent non-Gaussian behavior persist for t > 10 ns. At 600 K, the usual diffusion regime is obtained after a few hundred ps of subdiffusive behavior. Analysis of reorientational motions of acetate ions, particularly those of their short axes, indicates a high degree of dynamic heterogeneity, in agreement with previous work on different IL systems.
authors.affiliation: Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave, Pittsburgh, PA 15213, USA. hjkim@cmu.edu.
authors.forename: Jon A L
authors.initials: JA
authors.lastname: Willcox
authors.affiliation: Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave, Pittsburgh, PA 15213, USA. hjkim@cmu.edu.
authors.forename: Hyunjin
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave, Pittsburgh, PA 15213, USA. hjkim@cmu.edu and School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, Korea.
authors.forename: Hyung J
authors.initials: HJ
authors.lastname: Kim