Comprehensive thermochemical study of sublimation, melting and vaporization of scandium(III) beta-diketonates

Abstract The pressure of saturated and unsaturated vapor over solid and liquid scandium(III) complexes with acetylacetone Sc(acac)3, trifluoroacetylacetone Sc(tfac)3, and hexafluoroacetylacetone Sc(hfac)3 has been measured using a static method with glass membrane-gauge manometers and Knudsen effusion method with mass spectrometric gas phase monitoring. The temperatures and enthalpies of melting were measured for these compounds by differential scanning calorimetry. As a result of this study the thermal stabilities of investigated complexes were established, the temperature dependences of saturated vapor pressure were obtained, the thermodynamic characteristics of processes under study (ΔprH°T, ΔprS°T) were calculated. Thermal properties of these compounds were compared with literature data.