The isotopic and temperature dependent properties of hydrogen chloride dissolved in carbon tetrachloride. A molecular dynamics approach

Diluted mixtures of HCl and DCl in CCl4 were investigated by molecular dynamics simulation technique. The solutions were studied over a wide range of temperatures and at corresponding densities close to coexistence curve of the solvent. The thermodynamical properties obtained are found to be in good agreement with the experiment. The local structure around the solutes was described in terms of the calculated solute-solvent site-site pair distribution functions. We found that, over the entire range of investigation, the effect of density leads to a somewhat slight change of the basic solvation structure around the solute molecules. The behavior of the translational and rotational dynamics of the solutes with density was studied in terms of the center of mass linear velocity and the first-order reorientational autocorrelation functions (ACFs), respectively. We found that the extended Macedo-Litovitz theory [Ricci et al. J. Chem. Phys. 81 (1977) 171] predicts successfully the simulated diffusion coefficients of the solutes at these thermodynamic conditions. Finally, the simulated first-order reorientational ACFs of HCl and DCl were compared to each other as well as to the corresponding experimental ones and a reasonable agreement was obtained. (C) 2000 Elsevier Science B.V. All rights reserved.