Authors:N. Morozova, P. Semyannikov, S. Sysoev, V. Grankin, and I. Igumenov
The temperature dependency of the saturated vapor pressure of Ir(acac)3 has been measured by the method of calibrated volume (MCV), the Knudsen method, the flow transpiration method, and the membrane
method. The thermodynamic parameters of phase transition of a crystal to gas were calculated using each of these methods,
and the following values of ΔHT0 (kJ mol−1) and ΔST0 (J mol−1K−1), respectively, were obtained: MCV: 101.59, 156.70; Knudsen: 130.54, 224.40; Flow transpiration: 129.34, 212.23; Membrane:
Coprocessing of obtaining data (MCV, flow transportation method and Knudsen method) at temperature ranges 110−200C as also
conducted:ΔHT0 =127.92.1 (kJ mol−1 ); ΔST0 =215.25.0 (J mol−1 K−1 ).
Authors:S. Sysoev, T. Cheremisina, L. Zelenina, S. Tkachev, K. Zherikova, N. Morozova, and N. Kuratieva
The comprehensive analysis of volatile β-diketonate compound—ruthenium(III) trifruoroacetylacetonate (Ru(tfac)3)—was carried out. By means of flow method in quasi-equilibrium conditions and static method the temperature dependencies
of saturated vapor pressure have been measured over solid and liquid cis- and trans-modifications of Ru(tfac)3 and isomer mixture. The thermodynamic characteristics of sublimation, evaporation, melting, and phase conversion have been
calculated for structural isomers. Also by differential-scanning calorimetry the temperature meanings and the thermodynamic
characteristics of melting have been determined for individual isomers of Ru(tfac)3 and their mixtures. By XRD the structures for cis- and trans-modifications have been determined. Both structures consist of neutral molecules arranged in pseudo layers.
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:S. Sysoev, N. Morozova, G. Zharkova, I. Igumenov, P. Semyannikov, and V. Grankin
A thermoanalytical study of the diethyldithiocarbamates of the platinum metals Pt(II), Pd(II), Rh(III), Ir(III) and Ru(III)
was carried out by means of DTA techniques in an inert atmosphere and in vacuum. Decomposition temperatures were determined
and the mass loss curves were obtained for these compounds in helium and in vacuum. The X-ray diffraction patterns of the
solid products of M(dtk)n thermolysis were studied. The temperature dependences of the saturated vapour pressures of the listed
chelates were measured by flow and Knudsen methods, and the vaporization parameters were determined.
Authors:G. I. Zharkova, S. V. Sysoev, P. A. Stabnikov, V. A. Logvinenko, and I. K. Igumenov
Volatile palladium(II) β-iminoketonates of the general formula Pd(R–C(NH)–CH–CO–R1),where R and R1 are CH3, CF3, C(CH3)3 in various combinations, were synthesized and identified. Thermal properties of the resulting palladium(II) complexes in the solid phase were studied by thermogravimetric analysis under an argon atmosphere. The temperature dependence of the saturated vapor pressure was measured for the compounds by the flow method and thermodynamic characteristics of vaporization processes, enthalpy ΔHT and entropy ΔSTo, were determined. The atom-atomic potential calculation of the van der Waals energy (Ecryst) of the crystal lattice was performed and the results were compared to the experimental values of the sublimation enthalpy for the complexes under study.
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.
Authors:A. F. Bykov, N. B. Morozova, I. K. Igumenov, and S. V. Sysoev
By means of a tensimetric flow method and a static method with a silica-membrane zero gauge, the dependence of vapour pressure on temperature was obtained for tris(2,4-pentanedionato)ruthenium(III), Ru(aa)3, and tris(1,1,1-trifluoropentane-2,4-dionato)ruthenium(III), Ru(tfa)3. The thermodynamic characteristics of vaporization and sublimation of these complexes were determined. The processes of thermal decomposition of the vapour of the compounds in vacuum, hydrogen and oxygen were investigated by using mass spectrometry in the temperature range 170–550‡C for Ru(aa)3 and 150–620‡C for Ru(tfa)3. The threshold temperatures of the stability of the vapour of the complexes and the rate constants of the thermolysis processes were determined. The main gaseous products of the thermal decomposition and the dependences of their composition on the presence of hydrogen and oxygen were established.