  The development of novel task-specific ionic liquids (ILs) represents an
essential challenge in modern organic and physical chemistries. Recently we
reported surface-active ILs contained the two well-known organic cations
(1-butyl-3-methylimidazolium and tetrabutylammonium) and the two surface-active
anions (lauryl sulfate, lauryl ether sulfate). In the present work, we
investigate the affinity of these ionic compounds to the selected small
molecules that exhibit practical implications: water, hydrogen fluoride,
hydrogen sulfate, and carbon dioxide. We identified that the sulfate group, the
ether groups, and the aromatic imidazole ring make the strongest contributions
to the physical sorption of the polar gas molecules. In turn, the
tetrabutylammonium cation, the saturated hydrocarbon chain of the anions, and
the alkyl chains of 1-butyl-3-methylimidazolium contribute to a significantly
smaller extent. The reported data are interesting in the context of using
surface-active ILs in the oil industry to capture and store undesirable and
toxic gases.
