title: Solvation Structure of Uracil in Ionic Liquids.
abstract: The local solvation environment of uracil dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate has been studied using neutron diffraction techniques. At solvent:solute (ionic liquid:uracil) ratios of 3:1 and 2:1, little perturbation of the ion-ion correlations compared to those of the neat ionic liquid are observed. We find that solvation of the uracil is driven predominantly by the acetate anion of the solvent. While short distance correlations exist between uracil and the imidazolium cation, the geometry of these contacts suggest that they cannot be considered as hydrogen bonds, in contrast to other studies by Araújo et al. (J. M. Araújo, A. B. Pereiro, J. N. Canongia-Lopes, L. P. Rebelo, I. M. Marrucho, J. Phys. Chem. B 2013, 117, 4109-4120). Nevertheless, this combination of interactions of the solute with both the cation and anion components of the solvents helps explain the high solubility of the nucleobase in this media. In addition, favourable uracil-uracil contacts are observed, of similar magnitude to those between cation and uracil, and are also likely to aid dissolution.
authors.affiliation: ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QX, UK.|School of Chemistry and Chemical Engineering, David Keir Building, Queen's University Belfast, Belfast, Northern Ireland, BT9 5AG, UK.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Norman
authors.affiliation: School of Chemistry and Chemical Engineering, David Keir Building, Queen's University Belfast, Belfast, Northern Ireland, BT9 5AG, UK.
authors.forename: Adam H
authors.identifier: http://orcid.org/0000-0002-0579-7982
authors.initials: AH
authors.lastname: Turner
authors.affiliation: School of Chemistry and Chemical Engineering, David Keir Building, Queen's University Belfast, Belfast, Northern Ireland, BT9 5AG, UK.
authors.forename: John D
authors.identifier: http://orcid.org/0000-0002-3084-8438
authors.initials: JD
authors.lastname: Holbrey
authors.affiliation: ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QX, UK.
authors.forename: Tristan G A
authors.identifier: http://orcid.org/0000-0003-3538-5572
authors.initials: TG
authors.lastname: Youngs
mesh_terms: D006860:Hydrogen Bonding; D052578:Ionic Liquids / Q000737:chemistry*; D015394:Molecular Structure; D033363:Neutron Diffraction; D012995:Solubility; D014498:Uracil / Q000737:chemistry*
chemical_list: D052578:Ionic Liquids; D014498:Uracil
keywords: ionic liquids; liquids; neutron diffraction; solvation structure; uracil