Solvation Structure of Uracil in Ionic Liquids. Issue 23 (11th October 2016)

• Record Type: Journal Article
• Authors: Norman, Sarah E.; Turner, Adam H.; Holbrey, John D.; Youngs, Tristan G. A.
• Is Part Of: Chemphyschem. Volume 17:Issue 23(2016)
• Page Start: 3923
• Page End: 3931
• Publication Date: 2016-10-11
• Subjects: ionic liquids -- liquids -- neutron diffraction -- solvation structure -- uracil; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201600984
• Languages: English
• ISSNs: 1439-4235

Abstract

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. Abstract : Anions driving dissolution : The solution structure of uracil in an ionic liquid was studied with neutron diffraction, showing that the primary contact with the uracil was made by the anion through hydrogen bonds. Direct interactions between uracil and the cation were negligible, but a high probability for finding the cation's alkyl tails adjacent to the uracil ring was revealed.