Calculation of Kirkwood-Buff integrals for binary mixtures of 1-butyl-3-methylimidazolium nitrate ionic liquid and alcohols at 298.15 K

Abstract

Mixtures formed by 1-butyl-3-methylimidazolium + 2-Alkanol have been investigated in the framework of the Kirkwood–Buff theory of solution. The alcohols considered are 2-propanol, 2-butanol, and 2-pentanol. Data for the Kirkwood–Buff integrals, Gij excess or deficit number of molecules around the central ones, Δnij and coefficients of linear solvation, δij are reported. For solutions with a given ionic liquid (IL), the increase in the –CH2 groups of alcohols chain causes a decrease in G12 by the following sequences: 2-propanol > 2-butanol > 2-pentanol. The comparison of G12 and other calculated parameters for IL + 2-alkanol mixtures reveals that the interactions between dissimilar molecules are more outstanding and the rise of alkyl chain in alcohols leads to the weakening of interactions related to the self–association of 2-alkanol and structural effects. These trends are consistent with experimental data on excess molar volumes.