Gesamtdruckmessungen und Gasphasenzusammensetzung über Re2O7, ReO3 und ReO2

Total Pressure Measurements and Gas Phase Composition over Re₂O₇, ReO₃, and ReO₂ The total pressures over Re₂O₇, ReO₃, and ReO₂ have been determined by means of a membrane pressure gauge. The sublimation pressure over Re₂O₇ will be measureable at a temperature above 225°C and amounts 230 Torr at the melting point (at 315°C). The values are . ReO₃ decomposes at a temperature above 400°C according to with ΔH°_r,T = 214.6 ± 2kJ/mol and ΔS°_r,T = 263.2 ± 4J/K · mol. ReO₃ is not detectable in the gaseous phase in measurable quantities. ReO₂ decomposes at a temperature above 800°C according to with ΔH°_r,T = 387,0 ± 8.4 kJ/mol and ΔS°_r,T = 289.1 ± 12.5 J/K · mol.