Phase equilibria of binary systems containing crystalline inclusion compounds. Part 1. The perhydrotriphenylene–n-heptane system

Abstract

The vapour pressure of saturated solutions containing the perhydrotriphenylene (PHTP)–n-heptane inclusion compound as a solid phase shows a maximum at ca. 10 °C below the m.p. of the crystalline adduct. A second pressure maximum coincident with a eutectic point, is observed in the case of mixtures very rich in PHTP. Moreover, a sudden increase in pressure is observed in the case of pure or nearly pure inclusion compound in the close vicinity of the m.p. Such a behaviour is consistent with that predicted on the basis of the phase rule. The experimental values agree with those calculated by assuming the complete dissociation of the adduct in the liquid phase.