A Neutron Diffraction and Molecular Dynamics Investigation of Acetate-Based Ionic Liquids as Solvents for Glucose

• Published in: ECS transactions Vol. 33; no. 7; pp. 611 - 620
• Main Authors: Mullan, Claire L., Hardacre, Christopher, Holbrey, John, Lagunas, Cristina, Youngs, Tristan, Bowron, Daniel, Gladden, Lynn, Mantle, Mick, D'Agostino, Carmine
• Format: Journal Article
• Language: English
• Published: 01.01.2010
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/1.3484819

The liquid state structure of the ionic liquid, 1-ethyl-3-methylimidazolium acetate, and the solute/solvent structure of glucose dissolved in the ionic liquid at a 1:6 molar ratio have been investigated at 323 K by molecular dynamics simulations and neutron diffraction experiments using H/D isotopically substituted materials. Interactions between hydrogen-bond donating cation sites and polar, directional hydrogen-bond accepting acetate anions are examined. Ion-ion radial distribution functions for the neat ionic liquid, calculated from both MD and derived from the empirical potential structure refinement model to the experimental data, show the alternating shell-structure of anions around the cation, as anticipated. Spatial probability distributions reveal the main anion-to-cation features as in-plane interactions of anions with imidazolium ring hydrogens and cation-cation planar stacking. Interestingly, the presence of the polarised hydrogen-bond acceptor anion leads to increased anion-anion tail-tail structuring within each anion shell, indicating the onset of hydrophobic regions within the anion regions of the liquid.