Solid/liquid phase equilibria and solid compound formation in mixtures of hexafluorobenzene with nitrogen containing compounds

Abstract

Thermal methods have been used to determine with high precision the solid/liquid phase equilibria diagrams for mixtures of hexafluorobenzene with N-methylmorpholine, N-methylpiperidine and NN′-dimethylpiperazine. Solid addition compounds form in all three systems. Exploratory measurements show that hexafluorobenzene does not form solid addition compounds with triethylamine, acetonitrile or NN-dimethylacetamide. A comparison of the phase diagrams for a number of systems containing hexafluorobenzene suggests that compound formation with hexafluorobenzene results from a combination of favorable packing geometry and electrostatic interactions.