摘要:

Procedures are described for the preparation and extraction of carrier-free S35, based on the Cl35(n,p) S35reaction. Potassium chloride, sodium chloride, and ferric chloride have been used as target materials. The S35is found to appear in a chemical form which exchanges rapidly with sulphate ion. Separation of S35from irradiated potassium or sodium chloride is effected by taking advantage of the insolubility of these salts in aqueous hydrochloric acid solutions. Approximately 99.8% of the salt can be removed while leaving 95% of the S35in solution. Separation from irradiated ferric chloride is effected by solvent extraction of the ferric chloride from aqueous 6 to 8 Mhydrochloric acid solutions. Less than 0.1% of the total solids is left unextracted. The yield of S35approaches 100%.

ISSN:1923-4287    

DOI:10.1139/cjr49b-050

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

A homologue of Cyclonite has been prepared. This homologue, 1,3,6-trinitro-1,3,6-triazacycloheptane was formed by nitrolysis of methylene-bis-3,6-dinitro-1,3,6-triazacycloheptane, which was synthesized from N,N′-dimethylol-1,2-dinitraminoethane, formaldehyde, and ammonia. The reliability of this synthesis was established by analogous reactions. The nitrolysis yields also 1,8-diacetoxy-2,4,7-trinitro-2,4,7-triazaöctane via 1-acetoxymethyl-3,6-dinitro-1,3,6-triazacycloheptane. Ammonium nitrate has been shown to promote demethylolation in this series just as it does in the triazacyclohexane compounds. Analogies have therefore been drawn between these nitrolyses and that of hexamethylene-tetramine. Further comparisons derive from the isolation of 1-acetoxymethyl-3,6-dinitro-1,3,6-triazacycloheptane and 1-aceto-3,6-dinitro-1,3,6-triazacycloheptane by acetolysis of methylene-bis-dinitrotriazacycloheptane with acetic anhydride.

ISSN:1923-4287    

DOI:10.1139/cjr49b-051

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

When hexamethylenetetramine is nitrolyzed with nitric acid and an anhydride in absence of ammonium nitrate the synthesis of cyclic nitramines is decreased and the yields of esterified linear tetramethylenetrinitramines are increased. The two remaining carbon atoms and one nitrogen atom in hexamine can be accounted as esterified dimethylolnitramide. The isolation of a trace of linear pentamethylenetetranitramine from a normal nitrolysis of hexamethylenetetramine shows that in all of these reactions a common intermediate, dimethylolaminomethyldinitrotriazacyclohexane, must be present. This has never been isolated, but its reactions can be deduced from the behavior of methylene-bis-3,5-dinitro-1,3,5-triazacyclohexane.

ISSN:1923-4287    

DOI:10.1139/cjr49b-052

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Alternative hypotheses can account for the yield of more than one equivalent of Cyclonite from hexamine when the Bachmann reagents, ammonium nitrate, nitric acid, and acetic anhydride are used. In the nitrolysis, evidence for a stepwise synthesis from unit fragments is presented as the enhanced yield when methylenedinitramine is added with paraform to ammonium nitrate and acetic anhydride according to the Schiessler–Ross method for Cyclonite synthesis. However, this evidence is discounted because the expected by-product, 1,5-diacetoxy-2,4-dinitro-2,4-diazapentane is not found. Alternatively it is believed that the Bachmann reaction is actually a combination of the direct nitrolysis of hexamine with nitric acid, concurrent with a resynthesis of hexamine from the fragments produced by the nitrolysis. On this basis all by-products from the hexamethylenetetramine nitrolysis must be accounted as degradation products of hexamethylenetetramine and not capable of synthesis from unit fragments like formaldehyde, ammonia, and acetic acid. No exception has been found; the addition of acylamides to the Bachmann reaction mixture increases the yield of two by-products, 1-acyl-3,5-dinitro-1,3,5-triazacyclohexane and 1-acyl-3,5,7-trinitro-1,3,5,7-tetrazacycloöctane. It has been shown that these can be formed only from degradation products of hexamethylenetetramine such as 1,5-diaceto-3,7-endomethylene-1,3,5,7-tetrazacycloöctane and acetaminomethylhexamethylenetetramine nitrate.

ISSN:1923-4287    

DOI:10.1139/cjr49b-053

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Compensated gas counters of known efficiency, filled with carbon disulphide and carbon dioxide containing a mass-spectrometrically determined proportion of C14O2, have been used to determine the half life of C14. The half life has been found to be 6360 ± 200 years.

ISSN:1923-4287    

DOI:10.1139/cjr49b-054

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

The efficiencies of compensated gas counters filled with carbon dioxide and carbon disulphide have been investigated for the purpose of determining absolute disintegration rates of C14O2samples. In addition to comparing compensated counting units of different radii, a special counter has been constructed to determine the efficiency at different radii using a collimated beam of electrons from Tl-04. The carbon dioxide and carbon disulphide filled counters have been shown to be at least 97% efficient.

ISSN:1923-4287    

DOI:10.1139/cjr49b-055

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

When lignin is extracted from birch wood with acetic acid its behavior differs from that of lignin extracted with acetic acid and then boiled with formic acid. There is less hydroxyl lost per methoxyl gained when the lignin treated with formic acid is methylated with diazomethane. An increase in addition of Grignard reagent also corresponds to this increase in methoxyl. This indicates that a lactone linkage is present in extracted lignin but probably not in lignin in the wood, because the effect is less noticeable in lignin more mildly extracted by acetic acid. In dimethyl sulphate – alkali-methylated lignins, where the lactone would no longer be present there is evidence of a carboxyl group which can be diazomethane-methylated and the resulting ester saponified at will.

ISSN:1923-4287    

DOI:10.1139/cjr49b-056

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

Acetone has been isolated by permanganate oxidation of birch and spruce lignins extracted from wood by acetic or formic acid. Acetone was obtained also when the formic acid lignins were ozonized but not from the acetic acid – extracted lignins. This difference was confirmed when perbenzoic acid titration indicated unsaturation in the formic acid extract which was not present in the acetic acid extract. It is suggested that an α-hydroxy-β-methoxyisobutyl group is present in lignin; during acetic acid extraction the hydroxyl group is acetylated but during formic acid extraction the formic acid reduces the group to isobutenyl, which will give acetone when it is ozonized.

ISSN:1923-4287    

DOI:10.1139/cjr49b-057

出版商:NRC Research Press    

年代:1949

数据来源: NRC

摘要:

The ultraviolet absorption spectra of binary mixtures of nitric acid, water, acetic acid, acetic anhydride, and nitrogen pentoxide have been investigated over the ranges of concentration in which the systems exhibit sufficient chemical stability. The variations in the spectra are considered in relation to the other physical properties of the systems, as reported in the literature. The ultraviolet spectrum of nitric acid in the presence both of nitrogen pentoxide and water is interpreted in terms of a series of equilibria which involve the nitrate (NO3−) and nitronium (NO2+) ions and associated and nonassociated neutral molecules. The specific gravities of anhydrous nitric acid solutions of ammonium nitrate, potassium nitrate, ammonium acetate, acetic acid at 20 ± 0.1 °C. and of nitrogen pentoxide at 25 ± 0.1 °C. are also reported.

ISSN:1923-4287    

DOI:10.1139/cjr49b-058

出版商:NRC Research Press    

年代:1949

数据来源: NRC