The vapour pressures of liquid (2-diethylaminoethylamine (2-DEEA) + cyclohexane) mixtures were measured by a static method between (T = 273.15 and T = 363.15) K at 10 K intervals. The excess molar enthalpies H-E at 303.15 K were also measured. The molar excess Gibbs energies G(E) were obtained with Barker's method and fitted to the Redlich-Kister equation. The Wilson equation was also used. Deviations between experimental and predicted G(E) and H-E, by using DISQUAC model, were evaluated. The proximity effect of N atoms produces a decrease of the interactional parameters. (C) 2012 Elsevier Ltd. All rights reserved.