Destabilizing effects of chlorine on complexes belonging to the benzene family: p-C6H4Cl2-C6F6 and p-C6H4CH3Cl-C6F6 systems

Equilibrium phase diagrams of the p-dichlorobenzene-hexafluorobenzene and t he p-chlorotoluene-hexafluorobenzene binary systems are experimentally dete rmined by differential scanning calorimetry and X-ray diffraction analysis and optimized by computational thermodynamic analyses. Resulting data are t hermo-dynamically assessed through a substituted model for liquid phase and lead to the Gibbs free energy of complexation in the case of the p-chlorot oluene-hexafluorabenzene system. The first diagram is of the eutectic type, and the second one presents an equimolar complex. The comparison of these two systems with the benzene-hexafluorobenzene and the chlorobenzene-hexafl uorobenzene binaries shows that the stability of the complex decreases with number of H atoms substituted by Cl atoms in the benzenic ring.