Volatility and thermal stability of vanadyl β-diketonate complexes

Resumo

Thermal behavior and thermodynamic characteristics of vanadyl β-diketonates—acetylacetonate VO(acac)₂, dipivaloylmethanate VO(thd)₂, and tris-hexafluoroacetylacetonate VO(hfa)₂ (Hacac, 2,4-pentanedione; Hthd, 2,2,6,6-tetramethyl-3,5-heptanedione; Hhfa, 1,1,1,5,5,5-hexafluoro-2,4-pentanedione)—have been studied by thermal analysis and the Knudsen effusion mass spectrometry study of gas phase composition. The compounds have been shown to undergo congruent sublimation. Saturated vapor over the complexes has been shown to comprise monomeric VOL₂ molecules. Absolute values of partial pressures and sublimation enthalpies of these compounds have been determined.