摘要:

A review is given of gas reactions photosensitized by metal vapors, with special emphasis on the reactions of hydrocarbons sensitized by zinc, cadmium, and mercury.

ISSN:1923-4287    

DOI:10.1139/cjr48b-062

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

The reactions of atomic sodium with organic halides are briefly reviewed, with particular reference to the subsequent reactions of the free radicals formed. New values are reported for the rate constants of the reactions of atomic sodium with vinyl chloride and vinyl bromide. The formation of sodium hydride is shown to be important when hydrogen is used as the carrier gas. Vinyl radicals react with hydrogen to give ethylene. Acetylene and ethylene are formed by a disproportionation reaction.

ISSN:1923-4287    

DOI:10.1139/cjr48b-063

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

Spectroscopic evidence indicates that reactions photosensitized by fluorine would take place by way of fluorine atoms. Similarly, the sensitizing action of chlorine will practically always be due to chlorine atoms. For bromine, when the wave length is less than 5107 Å, reaction will be by way of bromine atoms. Experiments using wave lengths 5107–6290 Å also probably involve bromine atoms although the possibility of reaction due to excited bromine molecules cannot be wholly ruled out. Iodine atoms are produced in photosensitization experiments involving iodine and wave lengths less than 4989 Å. Experimental evidence also favors the production of iodine atoms using wave lengths up to 6200 Å. Mechanisms in accordance with the above are advanced for a number of chlorine sensitized oxidation reactions. In the oxidation reactions an intermediate compound with a trivalent carbon is formed which reacts with oxygen forming a peroxide, giving rise to a chain reaction. Reactions sensitized by bromine and iodine are also discussed. It appears that all the halogen sensitized gaseous photoreactions thus far known can be explained by chemical mechanisms involving halogen atoms.

ISSN:1923-4287    

DOI:10.1139/cjr48b-064

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

Methylene diacetate, paraldehyde, and their homologues decompose in the gaseous state by a unimolecular mechanism at temperatures low enough to ensure the absence of free radical complications. The effect of molecular structure on the activation energies, frequency factors, etc., of these and other decompositions is discussed.

ISSN:1923-4287    

DOI:10.1139/cjr48b-065

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

Radiation chemistry is a study of the chemical effects produced by the high energy particles and quanta usually associated with nuclear mutations. When water absorbs this kind of radiation, it is decomposed into hydrogen and hydrogen peroxide. The primary act of absorption is thought to result in the production of hydrogen atoms and hydroxyl radicals which then react to give the decomposition products. In dilute aqueous solutions the effects of radiation can generally be explained from a consideration of the probable effects of hydrogen atoms and hydroxyl radicals on the solute. This is true when the solute consists of biologically active material. Since biological systems consist largely of water, the "indirect effect" that radiation has upon them through the medium of atoms and radicals produced in the water is very important. In this laboratory an attempt is being made to gain information about the "indirect effect" by investigating the properties of irradiated water. Evidence has been obtained for the production of long lived activity in irradiated water which may be attributed to vibrationally excited "polymers" of water. The extraordinary efficiency of the indirect effect" of radiation is possibly related to properties of these excited polymers.

ISSN:1923-4287    

DOI:10.1139/cjr48b-066

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

An analysis of the products of sodium-catalyzed polymerization of butadiene and isoprene in the presence of toluene suggests that initiation of polymerization takes place by the formation of a disodium addend rather than a free radical. The diaddend reacts with toluene to yield butene-2 and sodium benzyl. Since all of the low molecular weight polymers analyzed were shown to conform to the general formula C6H5CH2(monomer)nH, sodium benzyl is considered to be the chief chain initiator. Chain termination took place by reaction with toluene to regenerate the chain carrier, sodium benzyl. The nature of the acids separated on carbonation of a polymerizing system supports this conclusion.

ISSN:1923-4287    

DOI:10.1139/cjr48b-067

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

Reasonably satisfactory preparations, starting from either methylated or ethylated vanillin, are given for the following compounds, which are believed to be new: 3-methoxy-4-ethoxybenzylamine, m.p. 48 °C., and its hydrochloride, m.p. 229 °C.; N-ethyl-3,4-dimethoxybenzalimine, m.p. 56 °C.; N-ethyl-3,4-dimethoxybenzylamine (uncrystallized); N-ethyl-3-methoxy-4-ethoxybenzylamine (uncrystallized); N,N′-di-(3,4-dimethoxybenzyl)-urea, m.p. 174 °C.; 3-methoxy-4-ethoxybenzylurea, m.p., 178 °C.; N,N′-di-(3-methoxy-4-ethoxybenzyl)-urea, m.p., 185 °C.;sym-N,N′-diethyl-di-(3,4-dimethoxybenzyl)-urea, m.p., 85 °C.; andsym-N,N′-diethyl-di-(3-methoxy-4-ethoxybenzyl)-urea, m.p. 74 °C. Di-(3,4-dimethoxybenzyl)-amine, m.p., 70 °C., and the phenyl carbamate of di-(3-methoxy-4-ethoxybenzyl)-amine, m.p., 95 °C., are incidentally described, together with an improved preparation of 3,4-dimethoxybenzylamine.

ISSN:1923-4287    

DOI:10.1139/cjr48b-068

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

Preparations are given forsym-N,N′-diethyl-di-(3-methoxy-4-ethoxybenzyl)-oxamide, m.p. 86 °C.; the corresponding succinamide, m.p. 125 °C.; forsym-N,N′-diethyldibenzylsuccinamide itself, m.p. 75 °C.; and for 3-methoxy-4-ethoxycinnamamide (o-ethyl ferulamide), m.p. 186 °C. No descriptions of these four substances were found in the literature. A convenient alternative preparation of ethyl benzylamine is described.

ISSN:1923-4287    

DOI:10.1139/cjr48b-069

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

The object of the work was to prepare alkoxylated derivatives ofsym-diethyldiphenylurea from methylated and ethylated vanillin. Standard procedures for converting methylated vanillin to 3,4-dimethoxyaniline were extended to the syntheses of the known 3-methoxy-4-ethoxyaniline. The following derivatives of 3,4-dimethoxyaniline are believed to be new: the formanilide, m.p. 91 °C.; sulphonamide, m.p. 132 °C.; N-ethylsulphonamide, m.p. 94 °C.; N-ethylacetanilide, m.p. 62 °C.; and the N-ethylaniline, an uncrystallized oil. Condensations of the last with phosgene yielded the N-ethylcarbamyl chloride, m.p. 86 °C.; N-ethyl-NN'-NN′-(3,4-dimethoxyphenyl)-urea, m.p. 159 °C.; and the correspondingsym-N,N′-diethyl derivative, m.p. 79 °C. N,N′-di-(3,4-dimethoxyphenyl)-urea, m.p. 214 °C., was synthesized by a method that removed previous doubt about its structure. The derivatives of 3-methoxy-4-ethoxyaniline believed to be new are: the hydrochloride, m.p. 221 °C.; the formanilide, m.p. 103 °C.; the N-ethylformanilide, m.p. 80 °C.; and the N-ethylaniline, m.p. 43 °C. Condensations of the last with phosgene gave the N-ethylcarbamyl chloride, m.p. 85 °C.; N-ethyl-N,N′-di-(3-methoxy-4-ethoxyphenyl)-urea, m.p. 127 °C. and the corresponding N,N′-diethyl derivative, m.p. 51 °C. A condensation of 3-methoxy-4-ethoxyaniline with urea resulted in the corresponding monosubstituted urea, m.p. 177 °C.; and N,N′-disubstituted urea, m.p. 209 °C. Yields were uniformly higher than those obtained in the 3,4-dimethoxy series.

ISSN:1923-4287    

DOI:10.1139/cjr48b-070

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

N-Ethyl-3,4-dimethoxyaniline (N-ethyl-4-aminoveratrole) was prepared in 50% to 60% yield by heating 4-bromoveratrole with aqueous ethylamine and a cuprous chloride catalyst at 95° to 100 °C. This synthesis was much better than those previously reported. Replacement of the ethylamine with ammonia yielded only 33% of crystalline 4-aminoveratrole, which others have shown to be much more readily accessible from the 4-nitro derivative. Some of the published methods of preparing 4-bromoveratrole from guaiacol were compared, and the compound was also obtained by the direct bromination of veratrole. The acetate of 4-bromoveratrole, m.p. 49 °C., and 3,4-dimethoxyformanilide, m.p. 88 °C., were described, apparently for the first time.

ISSN:1923-4287    

DOI:10.1139/cjr48b-071

出版商:NRC Research Press    

年代:1948

数据来源: NRC