Literature data for vapor liquid equilibria, activity coefficients at infinite dilution, enthalpies of mixing, volumes of mixing of alpha,omega-dichloroalkane (ClCH2-(CH2)(m-2)-CH2Cl, from m=1 to 6) + n-alkane mixtures together with vaporization enthalpies and molar volumes of pure dichloroalkanes were examined on the basis of the Nitta-Chao model. In this paper structure-dependent interaction energetic coefficients for this model were presented for a first time. According to the proximity effect when the two chloro groups of the chloroalkane are more separated they become independent and the reported values of the energetic parameters approach to those of the 1-chloroalkane. Similar trends were reported previously for several authors in the framework of the DISQUAC model A comparison with the predictions of DISQUAC and UNIFAC (version of Larsen et al.) is presented.