摘要:

Acetone has been photolyzed at temperatures above 300 °C. The formation of ethylene becomes of increasing importance at higher temperatures. The normal kinetics of the reaction are followed, however, and ethylene does not appear to be formed at the expense of ethane or methane.

ISSN:0008-4042    

DOI:10.1139/v54-042

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

Solutions of pureD-threose andD-erythrose, buffered with bicarbonate (0.82 moles) plus carbonate (0.18 moles), were treated with an equimolar amount of C14-labeled KCN. The aldonic acids were isolated as salts, using carrier technique, in yields of 90–95% based on the radioactive carbon.D-Erythrose gave 1.89 times as much arabonic as ribonic acid whileD-threose gave 2.36 times as much lyxonic as xylonic acid. Despite the unfavorable ratio in the latter case it was found thatD-xylose could be obtained in an over-all yield of 22%, based on the cyanide.

ISSN:0008-4042    

DOI:10.1139/v54-043

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

Chromatographic separation of the products formed on heating a mixture of the anomers of 2,3,4,6-tetra-O-acetyl-D-glucose and tri-O-acetyl-D-glucosanat 100 °C. affordedD-trehalose and theneo-D-trehalose of Haworth and Hickinbottom. Evidence was obtained to show that the latter compound is in fact α-D-glucopyranosyl β-D-glucopyranoside.

ISSN:0008-4042    

DOI:10.1139/v54-044

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

The relative rates of formation of C12—S32and C12—S34bonds in the bisulphite addition reaction of heptanal, benzaldehyde, anisaldehyde, and 2-heptanone have been measured and found to approximate unity. This result has been interpreted in terms of the Bigeleisen treatment of isotope effects in unidirectional processes.

ISSN:0008-4042    

DOI:10.1139/v54-045

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

The reaction of nitrogen atoms with propane has been found to produce hydrogen cyanide as the main product, together with smaller amounts of acetylene, ethylene, and ethane, which were recovered at all propane flow rates. Complete consumption of nitrogen atoms was not attained at any propane flow rate used at 63 °C, but was attained at 250 °C for ratios of propane to nitrogen atoms greater than 1.3. An activation energy of 5.6 ± 0.6 kcal. and a steric factor between 10−2and 10−3was estimated from second order rate constants.

ISSN:0008-4042    

DOI:10.1139/v54-046

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

Monoaminates of the trichlorides and pentachlorides of phosphorus, arsenic, antimony, and bismuth have been prepared, as well as triaminates of the trichlorides of phosphorus and arsenic and mixed polyaminates of the remaining chlorides. The co-ordinate valences and possible structures of the compounds are related to a model that depends on the geometry of the molecular halide and on the outer orbitals of the atoms in it.

ISSN:0008-4042    

DOI:10.1139/v54-047

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

TheD-glucose diethyl thioacetal tetraacetate prepared by Wolfrom and associates both by detritylation of 6-O-trityl-D-glucose diethyl thioacetal tetraacetate and mercaptalation of 2,3,4,6-tetra-O-acetyl-β-D-glucose was obtained by direct acetylation ofD-glucose diethyl thioacetal with acetic anhydride and sodium acetate. Methylation of the tetraacetate followed by deacetylation and demercaptalation gave only 2-O-methyl glucose and methyl β-D-glucopyranoside.

ISSN:0008-4042    

DOI:10.1139/v54-048

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

The pyrolysis of ethyl formate, isopropyl formate, ethyl acetate, and isopropyl acetate has been carried out under conditions which favor the decomposition of these esters into the corresponding acid and alkene to the exclusion of side reactions. The rate expressions found were: ethyl formate,k = 2.13 × 1011e−44,140 ± 200/RTsec−1; isopropyl formate,k = 3.8 × 1012e−44,000 ± 100/RTsec−1; ethyl acetate,k = 3.06 × 1012e−47,750 ± 100/RTsec−1; isopropyl acetate,k = 1.00 × 1013e−45,000 ± 100/RTsec−1. The nature of the transition state is discussed and compared with that for similar decompositions.

ISSN:0008-4042    

DOI:10.1139/v54-049

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

Approximately 0.003Msolutions of pyrogallol and of vanillin in boric acid – sodium hydroxide buffers were used at 25 °C. to reduce hypoiodite and hypochlorite solutions made from sixfold molar amounts of the halogens. In all four cases the reduction reached a maximum in a narrow range near pH 9, and with hypoiodite the production of iodoform was restricted to this range. Slower secondary reductions were superimposed on very fast primary reactions. When oxidized with an equimolar amount of halogen near pH 8.5, vanillin gave a 90% yield of 5-iodovanillin and 65% of the 5-chloro derivative. These yields decreased with increasing alkalinity as the halogenations became slower. A new, simple preparation of trichloropyrogallol in 72% yield consisted of carrying out the chlorination with 3 moles of hypochlorite at pH 12. An equilibrium between pyrogallol–hypoiodite and 3-hydroxy-1,2-benzoquinone–iodide appeared to exist at the same pH.

ISSN:0008-4042    

DOI:10.1139/v54-050

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

In the silver catalyzed oxidation of ethylene or ethylene oxide (EtO), the silver catalyst activity measured under constant standard conditions in a flow system was found to be dependent on the conditions of previous catalyst treatment such as reaction temperature and reactant composition. The results are explained on the basis of slow establishment of equilibrium respecting fixation of stably sorbed oxygen atoms and surface products of oxidation. It is emphasized that in view of the slow processes observed, the kinetic measurements must be punctuated by frequent stabilizing check runs in order to maintain the catalyst in the same reference state.

ISSN:0008-4042    

DOI:10.1139/v54-051

出版商:NRC Research Press    

年代:1954

数据来源: NRC