Thermodynamic study of sublimation, melting and vaporization of scandium(III) dipivaloylmethanate derivatives

• Thermal properties of two volatile fluorinated Sc(III) beta-diketonates were studied.
• Saturated and unsaturated vapor pressures were measured.
• DSC analysis was carried out.
• Sublimation, evaporation and melting enthalpies and entropies were derived.
• Effect of fluorine introduction on volatility and thermal stability was established.

The present work deals with the investigation of thermal properties of two volatile scandium(III) beta-diketonates with 2,2,6,6-tetramethyl-4-fluoro-3,5-heptanedione and 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione which have been synthesized and purified. Using the static method with glass membrane gauge-manometer the temperature dependencies of saturated and unsaturated vapor pressure were measured for the first time. The temperatures and enthalpies of melting were measured for these compounds by differential scanning calorimetry. The standard thermodynamic characteristics of enthalpy and entropy for sublimation, vaporization and melting processes were derived.

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