Relaxation, temporal diffusion, and polarity of aromatic hydrocarbons in ionic liquid

The influence of the polarity of aromatic hydrocarbons on the temporal heterogeneities in ionic liquids (IL)–aromatic hydrocarbons by molecular dynamics simulations are studied. The IL chosen for modeling belongs common class of ionic liquids based on imidazolium cation (dmim + ) with an average radius of 1,3-dimethyl-imidazolium cation equal to 3.30 × 10 −10 m, which can serve as a model for more complex non-symmetrical imidazolium salts. Based on the analysis of dynamic properties of ionic liquid solutions, the descriptions of diffusion mechanisms are built for dimethyl-imidazolium chloride (dmim + /Cl – )–aromatic hydrocarbons’ solute systems. The relaxation processes at short times are shown to determine the relaxation processes in dmim + /Cl – –aromatic hydrocarbon solutions; the dynamic properties of dmim + /Cl – suggest that when aromatic hydrocarbons with a non-zero dipole moment are dissolved in such IL, they increase relaxation time and retard the particle motion in the dmim + /Cl − IL to a greater extent than the non-polar aromatic hydrocarbons.