摘要:

Hg (63P1) at room temperature and at 300 °C. and Hg (61P1) at room temperature fail to react with carbon tetrafluoride at a measurable rate. Xe (3P1) causes carbon tetrafluoride to decompose with a quantum efficiency of about unity to yield fluorine and an unidentified solid product. It is concluded that the energy necessary to break the first C–F bond m CF4is more than 154 and less than 194 kcal. per mole. Hydrogen atoms produced from Hg (63P1) at room temperature and at 300 °C. and from Hg (61P1) at room temperature do not react with carbon tetrafluoride. It is concluded from this that the activation energy of the reaction CF4 + H → CF3 + HF is not less than 14 kcal. per mole.

ISSN:1923-4287    

DOI:10.1139/cjr50b-025

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Dielectric measurements were performed on solutions of polyvinyl acetate in toluene at three fixed frequencies over a temperature range. Both the molecular weight of the samples and their concentration in solution were systematically varied. The experiments show that the dielectric behavior of polyvinyl acetate in solution is in better qualitative agreement with the Debye theory of dielectrics than that generally found for solid polymers. Nevertheless serious discrepancies appear when a quantitative comparison is made. It was found that only rough approximations of the molecular size can be made from the Debye theory. Activation energies and entropies for dipole rotation were calculated on the basis of the theory of absolute reaction rates. Small positive values of the entropy were found, indicating restricted dipole rotation. A relatively narrow distribution of relaxation times, approaching that commonly associated with nonpolymeric materials, was found.

ISSN:1923-4287    

DOI:10.1139/cjr50b-026

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The variation of the diffusion coefficient of polystyrene with molecular weight in bromobenzene, toluene, and methyl ethyl ketone, obtained with a modified Northrop cell, obeyed the relation 1/D = AMϵwhereAand ϵ are empirical constants. The decrease in the exponent ϵ with increasing molecular weight agrees qualitatively with the predictions of Debye and Bueche. Both the exponent and the ratio of the diffusion coefficients of a low to high molecular weight sample increased in better solvents, indicating that in such solvents the polystyrene molecules are elongated. Using this ratio as a criterion of solvent power, there is good agreement with the results of swelling and precipitation studies. The decrease in the diffusion coefficient – solvent viscosity product for a low and a high molecular weight polymer in good solvents suggests an increase in the degree of solvation of the polymer. The variation of this product with solvent composition in solvent mixtures indicates the existence of selective solvation by the good solvent. The activation energies of diffusion were of the order of 3 kcal. for both high and low molecular weight polymers in good and poor solvents. This supports Eyring's theory of segment flow for polymer diffusion.

ISSN:1923-4287    

DOI:10.1139/cjr50b-027

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Nine α-amino acids, namely,dl-α-aminoundecylic acid,dl-α-aminostearic acid,dl-α-amino-β-methylcaproic acid,dl-α-amino-β-ethylvaleric acid,dl-α-amino-β-methylenanthic acid,dl-α-amino-α-acetylacetic acid,dl-α-amino-γ-cyclohexylbutyric acid,dl-α-(1-indanyl)-α-aminoacetic acid, anddl-proline have been prepared from ethyl alkylcyanoacetates. When a mixture of formic and hydrochloric acids and water was used, instead of hydrochloric acid, as hydrolyzing agent, α-amino-β-ethylvaleric acid and α-(1-indanyl)-α-aminoacetic acid were obtained with better yields. The following compounds, as far as the authors are aware, have been prepared for the first time: ethyl α-cyanoundecylate, α-cyanoundecylic hydrazide, anisal α-cyanoundecylic hydrazide, α-cyanoundecylic azide, α-carbethoxyaminoundecylonitrile,dl-α-aminoundecylic acid, 5-(n-nonyl)-hydantoin, α-cyanostearic hydrazide, anisal α-cyanostearic hydrazide, α-cyanostearic azide, α-carbethoxyaminostearonitrile, α-cyano-β-methylcaproic hydrazide, anisal α-cyano-β-methylcaproic hydrazide, α-cyano-β-methylcaproic azide, α-carbethoxyamino-β-methylcaproonitrile,dl-α-amino-β-methylcaproic acid and its copper salt, α-cyano-β-ethylvaleric hydrazide, anisal α-cyano-β-ethylvaleric hydrazide, α-cyano-β-ethylvaleric azide, α-carbethoxyamino-β-ethylvaleronitrile,dl-α-amino-β-ethylvaleric acid, and its copper salt, ethyl α-cyano-β-methylenanthate, α-cyano-β-methylenanthic hydrazide, anisal α-cyano-β-methylenanthic hydrazide, α-cyano-β-methylenanthic azide, α-carbethoxyamino-β-methylenanthonitrile,dl-α-amino-β-methylenanthic acid, and its copper salt, α-cyano-α-acetylacetic hydrazone, anisal α-cyano-α-acetylacetic hydrazone, α-cyano-α-acetylacetic azide, α-carbethoxyamino-α-acetylacetonitrile,dl-α-amino-α-acetylacetic acid, ethyl-α-cyano-γ-cyclohexylbutyrate, α-cyano-γ-cyclohexylbutyric hydrazide, anisal α-cyano-γ-cyclohexylbutyric hydrazide, α-cyano-γ-cyclohexylbutyric azide, α-carbethoxyamino-γ-cyclohexylbutyronitrile, 5-(β-cyclohexylethyl)-hydantoin, 1-in-danyl bromide, ethyl α-(1-indanyl)-α-cyanoacetate, α-(1-indanyl)-α-cyanoacetic hydrazide, anisal α-(1-indanyl)-α-cyanoacetic hydrazide, α-(1-indanyl)-α-cyanoacetic azide, α-(1-indanyl)-α-carbethoxyaminoacetonitrile,dl-α-(1-indanyl)-α-aminoacetic acid, and its copper salt, ethyl δ-chloro-α-cyanovalerate, δ-chloro-α-cyanovaleric hydrazide, anisal δ-chloro-α-cyanovaleric hydrazide, δ-chloro-α-cyanovaleric azide, δ-chloro-α-carbethoxyaminovaleronitrile.

ISSN:1923-4287    

DOI:10.1139/cjr50b-028

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The nitrolysis of N,N′-dicyclohexylimidazolidine has been effected with formation of the nitrate salt, the nitroso derivative, and the aceto derivative of N,N′-dicyclohexyl-N-nitro-1,2-diaminoethane. The absence of the dinitro derivative suggests that demethylolation is not related to nitramine formation. When formaldehyde splits off to leave a weakly basic amine, as in hexamethylenetetramine nitrolysis, then subsequent nitration will occur; but it will not take place if the resulting amine is strongly basic. Nitrolysis will depend also on reactivity of nitric acid, which can be decreased by addition of ammonium nitrate. This decrease will prevent esterification of intermediate N-methylolamines but not nitrolysis of hexamethylenetetramine types. However both nitrolysis and esterification are thus prevented with dicyclohexylimidazolidine. On the other hand the two nitrolyses are related by the fact that both are accelerated by electropositive chlorine.

ISSN:1923-4287    

DOI:10.1139/cjr50b-029

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Experiments have been performed to investigate whether the common acids formed by water can be replaced by solutions of proton donors in nonaqueous solvents for dissolving metals and oxides. Hydrogen chloride as proton donor and nitrogen compounds as solvents have been examined in particular. It has been found that molten hydrochlorides of some aromatic amines dissolve metals and oxides readily and at convenient temperatures. The advantages to be gained in analytical and radiochemistry by the use of such compounds instead of acids formed by water are discussed.

ISSN:1923-4287    

DOI:10.1139/cjr50b-030

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

One of the four racemates of XIV has been synthesized. The starting material was 2-cyclohexanone acetic acid. This compound was converted into the ethyl ester of 2-aminocyclohexylacetic acid which gave, with homoveratrylbromide, N-homoveratrylhexahydroöxindol. This compound by cyclization and hydrogenation was converted into XIV.

ISSN:1923-4287    

DOI:10.1139/cjr50b-031

出版商:NRC Research Press    

年代:1950

数据来源: NRC