Thermodynamicstudy of a series lithium β-diketonates

Thermal behaviour of a series of lithium β-diketonates: Li(dpm) (dpm=dipivaloylmethanate (2,2,6,6-tetramethylheptane-3,5- dionate)), Li(pta) (pta=pivaloyltrifluoracetonate (2,2-dimethyl-6,6,6-trifluoro-3,5-hexanedionate)), Li(tfa) (tfa=trifluoracetylacetonate (1,1,1-trifluoro-2,4-pentandionate)), Li(hfa) (hfa=hexafluoracetylacetonate (1,1,1,5,5,5-hexafluoro-2,4-pentandionate)) has been investigated. Gas phase composition of these complexes has been established. Temperature dependences of vapor pressure of lithium compounds were obtained by static and dynamic methods, and thermodynamic parameters were calculated. Dependence of compound volatility on ligand structure is shown. For Li(dpm) detailed investigation has been done by differential scanning calorimetry (DSC).