摘要:

The kinetics of the thermal decomposition of nitrous oxide on a silver catalyst has been investigated. The rate of the reaction can be expressed by the equationIt may therefore be concluded that the nitrous oxide is slightly adsorbed by the catalyst, while oxygen is fairly strongly adsorbed and retards the reaction. Added oxygen affects the reaction in the manner predicted by the rate equation, in contrast to its behavior on a platinum catalyst as previously found by Steacie and McCubbin.

ISSN:1923-4287    

DOI:10.1139/cjr37b-025

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

Ethylidene dibutyrate and heptylidene diacetate decompose in the vapor state at temperatures between 200° and 300 °C. to form an aldehyde and an anhydride. The reactions are homogeneous, unimolecular, and complete. The activation energy is the same as that previously found for other members of this homologous series. Ethylidene dibutyrate decomposes at the same rate as ethylidene diacetate, and thus provides further evidence that the specific reaction velocity is independent of the size of the anhydride radicals. Heptylidene diacetate decomposes at the same rate as butylidene diacetate. This indicates that after the aldehyde radical has attained a certain size (three or four carbon atoms) the addition of –CH2− groups leaves the specific reaction velocity unchanged. The velocity constants are given by the equations

ISSN:1923-4287    

DOI:10.1139/cjr37b-026

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

Trichlorethylidene diacetate and trichlorethylidene dibutyrate have been found to decompose at temperatures between 200° and 290 °C. at a measurable rate to give chloral and an acid anhydride. The reactions are homogeneous and of the first order, and have the same specific velocity in both the liquid and vapor states. The activation energy is identical (within experimental error) with that previously found for non-chlorinated members of this series of esters. The two compounds decompose at the same rate, in agreement with the hypothesis that the anhydride radicals do not easily exchange energy with the bonds that break. This reaction velocity, which is somewhat smaller than that of ethylidene diacetate at any temperature, is given by the equation.

ISSN:1923-4287    

DOI:10.1139/cjr37b-027

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

The vapor phase decomposition of furfurylidene diacetate and crotonylidene diacetate to acetic anhydride and their respective aldehydes is homogeneous, first order, and complete. The activation energy is that characteristic of the series,viz., 33,000 cal. The specific reaction rates of the two esters are the same, and are about six times as great as that of ethylidene diacetate at any temperature. It is suggested that the increased velocity is due to the presence of the double bond. Velocity constants are given by the equation.

ISSN:1923-4287    

DOI:10.1139/cjr37b-028

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

Using the Wood-Bonhoeffer method, an investigation has been made of the reaction of deuterium atoms with methane at temperatures up to 500 °C. Owing to the difficulties involved in poisoning the walls to prevent atom recombination at high temperatures, the atom concentration was very variable. The results are therefore only approximate, but they serve to establish definitely the presence of a reaction at the temperatures under investigation, and enable the estimation of the activation energy of the reactionviz., 12.9 ± 2 Kcal. This is in good agreement with values obtained in other investigations.

ISSN:1923-4287    

DOI:10.1139/cjr37b-029

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

Bicuculline, protopine, and cryptopine have been isolated from both of the species mentioned in the title. In addition,Dicentra chrysanthawas found to contain two new alkaloids, namely, −v, C19H17O6N, phenolic, andchrycentrine, C18H15O5N, non-phenolic. Neither alkaloid contains methoxyl groups. A very small quantity of a sixth alkaloid, as yet not characterized fromD.chrysantha, proved to be identical with a base recently isolated fromCorydalis ochotensis.

ISSN:1923-4287    

DOI:10.1139/cjr37b-030

出版商:NRC Research Press    

年代:1937

数据来源: NRC