Computer-Aided Molecular Design of New Task-Specific Ionic Liquids for Extractive Desulfurization of Gasoline

New ionic liquids
(ILs) for extractive removal of organic sulfur
compounds from gasoline are proposed following the results of computer-aided
molecular design (CAMD), comprising application of the extensive group
contribution model for infinite dilution activity coefficients of
molecular solutes in ILs presented previously [J. Chem. Inf.
Model. 2016, 56, 1420–1437].
Infinite dilution selectivity of model system thiophene/n-heptane was adopted as a benchmark property. The proposed structures,
selected on the basis of screening of almost 25 800 cation–anion
combinations, were synthesized and characterized from the point of
view of their thermal behavior and fundamental physical properties,
density, and dynamic viscosity. Besides, general remarks regarding
an impact of cation/anion structure on extraction selectivity are
highlighted and discussed based on the calculations carried out. Liquid–liquid
phase equilibrium diagrams in ternary systems {IL + thiophene + n-heptane} were determined at T = 308.15
K in the entire range of feed composition in order to verify robustness
and reliability of the applied CAMD approach. Finally, performance
of the proposed extraction solvents in thiophene/n-heptane separation is confronted against 39 other ILs reported in
the literature.