Τίτλος:
On the interplay between the local structure and dynamics in low concentration mixtures of H2O and HOD in the [Emim+][TF2N−] room temperature ionic liquid
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Molecular Dynamics simulations have been employed to investigate the local structural and dynamic properties of low-concentrated water and HOD dissolved in an ionic liquid consisting of the 1-ethyl-3-methylimidazolium cation and the bis(trifluoromethylsulfonyl)imide anion. The results obtained disclose that the water molecules interpenetrate the ionic structural networks and interact with the anions and the cations of the ionic liquid. The calculations have also revealed a strong interaction between the oxygen atoms of the anion and the hydrogen atoms of the water molecules and a quite important interaction between the hydrogen atoms of the imidazolium ring with the water oxygen atoms. The translational and rotational diffusion of water molecules is almost one order of magnitude lower in comparison with pure water, but still one order of magnitude higher in comparison with the ionic liquid's anions and cations. The translational diffusion of the anions is lower than the diffusion of the cations, whereas the rotational diffusion is very similar. However, the reorientational dynamics of the anion and the cation is very anisotropic and the mechanisms of the rotation around different intramolecular axes take place at different time scales. The calculated orientational anisotropy of the O-D vector of HOD in the ionic liquid has been found to be in very good agreement with available experimental data, showing more pronounced differences with the O-H vector reorientational dynamics at long-time scales. © 2019 Elsevier B.V.
Συγγραφείς:
Skarmoutsos, I.
Spyrogiannopoulos, L.
Kainourgiakis, E.
Samios, J.
Περιοδικό:
Journal of Molecular Liquids
Λέξεις-κλειδιά:
Anisotropy; Atoms; Diffusion in solids; Hydrogen; Molecular dynamics; Molecules; Negative ions; Oxygen; Positive ions; Water, Isotopic effects; Molecular dynamics simulations; Orientational anisotropy; Preferential solvation; Reorientational dynamics; Room temperature ionic liquids; Rotational dynamics; Structural and dynamic properties, Ionic liquids
DOI:
10.1016/j.molliq.2019.111135
