Connecting the normal pressure equilibria of the two-component system CCl(CH3)3Â +Â CBrCl3 to the pressure-temperature phase diagrams of pure components

The orientationally disordered (OD) mixed crystals of the two-component system 2-methyl-2-chloropropane (CCl(CH3)3) + bromotrichloromethane (CBrCl3) have been characterized. The continuous formation of OD face-centred cubic (FCC) mixed crystals and the existence of a large concentration domain of OD rhombohedral (R) mixed crystals together with a narrow [R + FCC] two-phase equilibrium enable to get the thermodynamic properties of a virtual phase transition between a metastable R and the stable FCC phases for CCl(CH3)3 and to connect such a transition with the high-pressure stable phase for that compound, for which the symmetry is inferred.