Aqueous Solutions of Ionic Liquids: Microscopic Assembly |
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| Authors: | Jose Manuel Vicent‐Luna Dr David Dubbeldam Dr Paula Gómez‐Álvarez Prof Sofia Calero |
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| Affiliation: | 1. Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, Seville, Spain;2. Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands |
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| Abstract: | Aqueous solutions of ionic liquids are of special interest, due to the distinctive properties of ionic liquids, in particular, their amphiphilic character. A better understanding of the structure–property relationships of such systems is hence desirable. One of the crucial molecular‐level interactions that influences the macroscopic behavior is hydrogen bonding. In this work, we conduct molecular dynamics simulations to investigate the effects of ionic liquids on the hydrogen‐bond network of water in dilute aqueous solutions of ionic liquids with various combinations of cations and anions. Calculations are performed for imidazolium‐based cations with alkyl chains of different lengths and for a variety of anions, namely, Br]?, NO3]?, SCN]?, BF4]?, PF6]?, and Tf2N]?. The structure of water and the water–ionic liquid interactions involved in the formation of a heterogeneous network are analyzed by using radial distribution functions and hydrogen‐bond statistics. To this end, we employ the geometric criterion of the hydrogen‐bond definition and it is shown that the structure of water is sensitive to the amount of ionic liquid and to the anion type. In particular, SCN]? and Tf2N]? were found to be the most hydrophilic and hydrophobic anions, respectively. Conversely, the cation chain length did not influence the results. |
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| Keywords: | hydrogen bonds imidazolium molecular dynamics ionic liquids structure of water |
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