Authors:E. Filatov, S. Sysoev, Ludmila Zelenina, Tamara Chusova, V. Logvinenko, P. Semyannikov, and I. Igumenov
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).
Authors:Kseniya V. Zherikova, Ludmila N. Zelenina, Natalia B. Morozova, and Tamara P. Chusova
Complexes of ruthenium(III) with the following beta-diketone derivatives: 2,4-pentanedione (Ru(acac)3), 1,1,1,6,6,6-hexafluoro-2,4-pentanedione (Ru(hfac)3), and 2-methoxy-2,6-dimethyl-3,5-heptanedione (Ru(mdhd)3) were synthesized, purified, and identified by chemical analysis and melting points. By difference-scanning calorimetry (DSC) in vacuum the thermodynamic characteristics of melting processes were defined. Using the static method with quartz membrane zero-manometer, the temperature dependencies of saturated and unsaturated vapor pressure were obtained for Ru(hfac)3. The standard thermodynamic characteristics of vaporization processes enthalpy ΔHT* and entropy ΔS°T* were determined.
Authors:Ksenia Zherikova, Natalia Morozova, Ludmila Zelenina, S. Sysoev, Tamara Chusova, and I. Igumenov
Five volatile hafnium(IV) and zirconium(IV) β-diketonates: hafnium(IV) acetylacetonate, hafnium(IV) trifluoroacetylacetonate,
hafnium(IV) pivaloyltrifluoroacetonate, hafnium(IV) 2,2,6,6-tetramethylheptane-3,5-dionate and zirconium(IV) 2,2,6,6-tetramethylheptane-3,5-dionate
were obtained, purified and identified. Thermal behavior of solid compounds was investigated by thermogravimetry (TG) and
differential scanning calorimetry (DSC) in helium atmosphere and in vacuum. DSC method was also used for definition of thermodynamic
characteristics of melting processes. Using the static method with quartz membrane zero-manometer and the flow method the
temperature dependencies of saturated vapor pressure for hafnium(IV) complexes was obtained. The standard thermodynamic characteristics
ΔHT0 and ΔST0 of sublimation and evaporation processes were calculated from the temperature dependences of saturated vapor pressure.