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 N 2-butanol N 2- pentanol. The comparison of G12 and other calculated parameters for IL+2-alkanolmixtures reveals that the interactions between dissimilarmolecules 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
