Binary phase diagram between phenanthrene and its main impurity: dibenzothiophene

The binary phase diagram between commercial Phenanthrene and its main impurity, Dibenzothiophene, is established under atmospheric pressure by means of structural and thermal analyses. This determination appears as a requirement for performing efficient zone melting on Phenanthrene. The investigations on this binary phase diagram reveal stable and metastable eutectic invariants and a single eutectoid invariant. Two hypotheses are proposed for an undetermined invariant detected at 80°C in the domain rich in Dibenzothiophene. Moreover, solid-solutions in the Phenanthrene rich-domain are characterized. Finally, the impact of these heterogeneous equilibria on the feasibility of Phenanthrene refining by means of zone melting is discussed