An analysis of the possible causes of apparent compensation effects when investigating a substance under varying experimental conditions

The major causes leading to the apparent compensation effect (lgA=aE+b) at the thermal decomposition of one and the same substance in a series of experimental conditions (varying of the mass of the sample, of the heating rate, of disperseness, and at different distances from the equilibrium) were discussed. It was found that the appearance of a compensation effect at the study of the thermal decomposition of one and the same substance demonstrates the incorrect setup of the experiment, resulting in erroneous values calculated for the kinetic parameters.

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Zusammenfassung Die Hauptursachen, welche zum scheinbaren Kompensationseffekt (lgA=aE+b) der thermischen Zersetzung ein und derselben Substanz führen, wurden unter verschiedenen Versuchsbedingungen untersucht: unter Änderung der Probenmasse, der Aufheizgeschwindigkeit, der Dispersität und der Entfernung vom Gleichgewicht. Es wurde festgestellt, daß das Auftreten eines Kompensationseffekts bei der Untersuchung der thermischen Zersetzung ein und derselben Substanz auf die unrichtige Durchführung des Experiments hinweist, die zur Berechnung falscher Werte der kinetischen Parameter führt.

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Résumé On a étudié les causes principales de l'effet de compensation apparent (lgA=aE+ +b) lors de la décomposition thermique de la même substance dans différentes conditions expérimentales, en faisant varier notamment la masse du prélèvement, la vitesse du chauffage, la dispersion et l'écart à l'équilibre. On a trouvé que l'apparition d'un effet de compensation lors de l'étude de la décomposition thermique de la même substance résultait de l'exécution incorrecte de l'expérience qui mène à des valeurs fausses lors du calcul des paramètres cinétiques.

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, (lg A=aE+b) : , , , . , , .

     

Stabilization of reaction products of ureas with polyfluoro ketones

Conclusions Polyfluorinated tetrahydro-1,3,5-oxadiazine derivatives were obtained by the condensation of urea and thiourea with polyfluoro ketones.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2168–2169, September, 1977.     

Photochemical and thermal transformations of azomethine imines

The thermal and photochemical fragmentations of a few bisazoalkenes have been investigated. 2-Phenyl-4,5-disubstituted-1, 2,3-triazoles were obtained both in the thermolysis and photolysis of 1, 2-bisphenylazo-(4, 4′-dichloro) stilbene, 1, 2-bisphenylazo(4, 4′-dimethoxy)stilbene, 1, 2-bisphenylazocyclohexene and o-(phenylazo) phenyldiazocyanide. Both 2, 3-bisphenylazo-2-butene and 1, 2-bisphenylazoethylene failed to undergo either photolysis or thermolysis in the expected manner. However, 2, 3-bisphenylazo-2-butene underwent an acid-catalysed valence isomerisation to anhydro 1-phenylimino-2-phenyl-4, 5-dimethyl-1, 2, 3-trizolium hydroxide, which on photolysis gave 2-phenyl-4, 5-dimethyl-1, 2, 3-triazole. The same iminotriazolium intermediate gave a cycloadduct, 2, 6-diphenyl-3, 3a-dimethyl-4, 5-dicarbomethoxypyrazolino [2.3.c][1.2.3] triazole, on treatment with dimethyl acetylenedicarboxylate, whereas treatment with carbon disulphide gave 2-phenyl-4, 5-dimethyl-1, 2, 3-triazole. Both photolysis and thermolysis of C-biphenylene-N^α(4-chlorophenyl)-N^β-cyanoazomethine imine gave 9-fluorenone-N- (4-chlorophenyl) anil. Photolysis of 1, 2-bisphenylazoacenaphthylene in methanol gave acenaphthenequinone monophenylhydrazone.     

Simple method for the preparation of 1-oxo-1-chlorophospholenes

Conclusions A new and simple method has been found for the synthesis of 1-oxo-1-chlorophospholenes by the reaction of phosphorus trichloride, a diene, and an oxygen-donor compound, the best of which is acetone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1847–1848, August, 1972.     

The role of electronic factors in reagents in controlling thestereochemistry of arylsulfenyl chlorides addition

For a series of substituted arylsulfenyl chlorides the stereochemistry of Ad_E-reactions with a series of substituted Z- and E-β-deuterostyrenes has been elucidated. Non-stereospecific reaction was observed only for the pair 2,4-dinitrobenzenesulfenyl chloride-p-methoxystyrene; for all the other reactants the reaction proceeded in a strictly stereospecific manner.