摘要:

Transmittance measurements were used to investigate vertical concentration gradients, at temperatures slightly above the critical, in a binary liquid system. The gradients, which are predicted theoretically, did not begin to form during time intervals of several hours. It was found that a theoretical relation between transmittance and concentration gradient did not apply, even qualitatively, to the results obtained. The significance of these observations is discussed.

ISSN:0008-4042    

DOI:10.1139/v58-058

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

A technique is described in which the origins of the products of photooxidation of ketones can be obtained in respect to whether they arise from the carbonyl or the alkyl groups of the ketone molecule. This is accomplished with the use of reactant molecular oxygen which has been enriched in the O18isotope. Application of this to the photooxidation of acetone indicates that a large fraction of the carbon dioxide contains the carbonyl group of the ketone and that acetyl radicals play an important role in the oxidation to temperatures at least as high as 175 °C. Propionyl radicals are much less stable, and, in the photooxidation of diethyl ketone, their reactions, other than decomposition, appear to be negligible at quite low temperatures. Some comment is made on the mechanisms of these photooxidations.

ISSN:0008-4042    

DOI:10.1139/v58-059

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

A method is described whereby radiochemical analysis for the long-lived fission products Ru106, Sr90, Cs137, and Ce144may be performed on the same sample of soil, water, or biological material. Carriers are added and the material is fused at 550 °C. with KOH, KNO3, and K2CO3. Ruthenium and cesium are extracted with water, strontium and cerium remaining in the melt. Ruthenium is extracted into carbon tetrachloride as ruthenium tetroxide, cesium is absorbed on Duolite C-3 cation-exchange resin from alkaline solution, strontium and cerium are extracted from the melt with acid, cerium is precipitated as the hydroxide and strontium as the carbonate. The elements are precipitated, weighed, and counted according to standard procedures.

ISSN:0008-4042    

DOI:10.1139/v58-060

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v58-061

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Peat moss (Sphagnum) from the surface of an Atlantic peat bog has been extracted with a mixture of benzene and ethanol. The extract has been fractionated chromatographically on alumina. A mixture of sterols has been isolated from one fraction. This mixture has been proved by oxidation experiments to consist of β-sitostanol (stigmastanol) and β-sitosterol. It constituted approximately 0.2% by weight of the dried peat moss.

ISSN:0008-4042    

DOI:10.1139/v58-062

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The synthesis of lauric acids deuterated in the carboxyl, the terminal methyl, and the α-methylene groups and in various combinations of these is described. The methyl and methyl-d3esters of each of the acids were also prepared.Two further examples of homolytic halide addition to olefins are reported.The reaction between alkyl halides and silver acetylides is described. A mechanism involving a new type of free radical is postulated.

ISSN:0008-4042    

DOI:10.1139/v58-063

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The equivalent conductance of a series of alkali chlorides has been measured in water–hydrogen peroxide mixtures over the whole range of solvent composition. The measurements were made by a simple direct-current method, and the results obtained are interpreted in terms of the viscosity of the solvent.

ISSN:0008-4042    

DOI:10.1139/v58-064

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The conductivities of HCl, H2SO4, HNO3, and a number of their alkali metallic salts were measured in ethylene glycol. The influence of the addition of water, methanol, and hydrogen peroxide was determined. The results are discussed on the basis of well-known theories of electrolytic conductivity involving H+ions.

ISSN:0008-4042    

DOI:10.1139/v58-065

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Compounds previously known as nitraminopyridines and 2-nitraminothiazoles are formulated as nitrimino-(1H)pyridinium and 2-nitrimino-(3H)thiazolium inner salts on the basis of the infrared study. In the solid state, the three isomer nitriminopyridines do not exhibit any infrared absorption of the —NH group in the region 3400–3200 cm.−1but show a wide band at lower frequencies in the region 2880–2550 cm−1. 2-Nitriminothiazole shows only a wide band between 3140 and 2270 cm.−1. These shifts of absorption bands can be correlated with structures derived from the classical nitrimino tautomeric forms in which the resonance effect stabilizes (1H)pyridinium and (3H)thiazolium cations, and a nitrimino group carrying a negative charge.n-Butylnitramine, a non-resonating compound, absorbs strongly at 3300 cm.−1, indicating that nitramino groups are not associated.

ISSN:0008-4042    

DOI:10.1139/v58-066

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Desoxodihydroannotinine reacted with phenyl lithium to yield a diphenyl derivative, C28H35O2N (III). This compound yielded a ketone, C28H33O2N (V), upon oxidation by the Oppenauer procedure and a dihydroxyketone, C28H33O3N (VI), upon oxidation with chromic acid. A ketone VIII, epimeric with V, was obtained by treatment of III with potassium tertiary butoxide in cyclohexanone. Both V and VIII underwent elimination of their diphenyl carbinol groups upon treatment with potassium tertiary butoxide to yield an unsaturated ketone, C15H21ON (IX), and benzohydrol. These reactions are discussed in relation to the recently proposed structures for the parent alkaloid, annotinine.

ISSN:0008-4042    

DOI:10.1139/v58-067

出版商:NRC Research Press    

年代:1958

数据来源: NRC