Rationalizing the diverse solid-liquid equilibria of binary mixtures of benzene and its fluorinated derivatives.
The solid-liquid phase behavior of benzene plus hexafluorobenzene binary mixtures is characterized by a stable congruent-melting binary solid, (C(6)H(6)·C(6)F(6)). In this work, differential scanning calorimetry (DSC) was used to build, for the first time, the temperature-composition phase diagrams of ten other binary mixtures involving benzene and its fluorinated derivatives. Distinct types of solid-liquid equilibria were observed, namely those exhibiting the usual eutectic behavior associated with ideal or quasi-ideal solubility conditions, or, in other cases, systems with equimolar congruent-melting solids. Data have been interpreted and rationalized using a unifying framework that takes into account the molecular dipole and quadrupole moments of the two components of each binary system and the structural motifs associated with each type of crystal.
Ruivo
Diana
D
Instituto de Tecnologia Química e Biológica, (www.itqb.unl.pt), UNL, Av. República, Apartado 127, 2780-901 Oeiras, Portugal.
Pereiro
Ana B
AB
Esperança
José M S S
JM
Canongia Lopes
José N
JN
Rebelo
Luis P N
LP