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Mechanism of Hydrogen Abstraction by O- Species in Oxidative Dehydrogenation of Early Al kanes: Propane, Ethane and Methane. Model Theoretical DFT Study

Góra A., Broclawik E.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 9

1793-1799

EN

Decomposition of methanol was adopted as a simple test for standardizing of activity of ZnO containing superbasic catalysts with respect to their applicability in CH3OH synthesis. The values of the rate constants and activation energies were evaluated considering the reaction mechanism. Obtained data were compared with those obtained for Pd/SiO2 and Pt/SiO2 catalysts.

2

An Evaluation of the Kinetic Data for Hydrogen Abstraction from Germanes in the Gas Phase by CF3 and C2F5 Radicals

Pieniążek M.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 12

1739-1746

EN

After the review of kinetic data for reaction of hydrogen abstraction from germanoorganic compounds by trifluoromethyl and pentafluoroethyl radicals in the gas phase it was possible to determine the relative kinetic reactivity of the two radicals under consideration. The contributing factors are the thermochemical effects of the investigated reactions, steric hindrance derived mainly from the size of substrate molecules and the polar interaction between the polarized germane molecules and the radicals of different electrophilicity. The polar effects occurring in these radical reactions contribute primarily to the activation energy, but they have no significant contribution to the preexponential factor.

3

Kinetyka reakcji rodników trifluorometylowych z sulfidem dimetylowym

Pieniążek M.

Chemia i Inżynieria Ekologiczna

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2000

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Vol. 7, nr 8-9

909-913

PL

Badania kinetyki fotolizy jodku trifluorometylowego w obecności sulfidu dimetylowego prowadzono w fazie gazowej w układzie statycznym w fazie gazowej w przedziale temperatur 357-446 K i przedziale ciśnień dla: jodku trifluorometylowego 616-7116 N/m2 oraz sulfidu dimetylowego 150-1333 N/m2. Przebieg reakcji kontrolowano za pomocą chromatografii gazowej. Stałe szybkości reakcji odrywania atomów wodoru z sulfidu dimetylowego przez rodniki trifluorometylowe wyznaczono w odniesieniu do znanej wartości stałej szybkości reakcji rekombinacji rodników CF3. Wyznaczone wartości parametrów równania Arrheniusa wynoszą: E = 24,39 kJ/mol, log A[cm 3/mol s] = 11,28. Wyniki badań omówiono i porównano z literaturowymi danymi kinetycznymi dla analogicznych reakcji rodnikowego odrywania wodoru.

EN

The gas-phase kinetic study of trifluoromethyl iodide photolysis in the presence of dimethyl sulphide has been carried out in the static system in the temperature range 357-446 K and pressure range 616-7116 N/m2 for trifluoromethyl iodide, 150-1333 N/m2 for dimethyl sulphide. The reactions have been controlled by gas chromatography. The rate constants of hydrogen abstraction reactions from dimethyl sulphide by trifluoromethyl radicals based on the known value of the rate constant for the recombination of trifluoromethyl radicals. The following Arrhenius parameters have been determined: E = 24,39 kJ/mol, log A [cmJ/mol s] = 11,28. The results have been discussed and compared with kinetic data for the hydrogen abstraction reactions for analogous radicals.