Chemistry Research and Practice

Dialkyl Substituent Effects on the Interaction of Imidazolium Ionic Liquids with POPC Membranes by Molecular Dynamics

Abstract

Leandro Segat, Luís Alberto Loureiro dos Santos and Hubert Stassen

We employed molecular dynamics computer simulations to examine the effect of a second alkyl group on the cations of imidazolium-based ionic liquids on the properties of a fully hydrated POPC membrane. While maintaining a fixed hexadecyl group on the cations, a second methyl, butyl, and octyl group were considered. In any case, the cations rapidly inserted into the bilayer, maintaining membrane integrity without structural disruption. Radial distribution functions and density profiles indicate that an increase in the second alkyl chain on the cation favors a configuration with deeper insertion. The presence of the cations promotes structural perturbations in the lipid area and bilayer thickness, particularly the cation with the butyl substituent, while preserving the hydration of the polar region of the bilayer without promoting water penetration into the lipophilic region.

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