摘要:

Spruce sawdust was chlorinated under various conditions in an attempt to procure a homogeneous lignin chloride. Success finally attended the use of methyl alcohol as a medium for chlorination. The lignin chloride, which was dissolved by the alcohol during the chlorination and subsequently precipitated by the addition of water, was cream white in color, and analysis showed it to be an alcohol lignin.A homogeneous fraction (No. 2) was obtained from the re-chlorinated product, and it proved to be a chlorinated analogue of Hibbert's monomethylated methyl alcohol lignin, the formulas of the two products being C42H22O6Cl13(OH)2(OCH3)7, and C42H32O6(OH)3(OCH3)7. The molecular weight and the presence of the two hydroxyl groups were confirmed by acetylation, when 2.0 acetyl groups entered the molecule. Eleven of the chlorine atoms in Fraction 2 have evidently replaced ten hydrogen atoms and one hydroxyl group by simple substitution in methyl alcohol lignin, leaving two chlorine atoms which have apparently entered to saturate a double bond. Seven of these chlorine atoms have been shown to be readily removable either by an alkali or by acid reduction. The other six, because of their stable union with the molecule, are surmised to be joined to an aromatic nucleus or at least to some type of ring structure. The product has been shown to react stoichiometrically within limits as narrow as could be expected for such a large molecule.

ISSN:1923-4287    

DOI:10.1139/cjr37b-031

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

A new method of obtaining information concerning the participation of free radicals in decomposition reactions is described. A mixture of two organic compounds is decomposed, all the hydrogen in one of the compounds having been replaced by deuterium. By an examination of the distribution of deuterium among the products, it is possible to obtain considerable insight into the mechanism of the process.Mixtures of deutero-acetone and dimethyl ether have been decomposed at 590 °C. It is found that the hydrogen in the products is entirely "light" within the experimental error. This precludes the possibility that formaldehyde (which is the source of the hydrogen) decomposes by a free radical mechanism, HCHO = H + CHO, as otherwise reaction of hydrogen atoms with deutero-acetone would lead to the formation of HD.It is also concluded that it is unlikely that formaldehyde formed in the methyl ether decomposition is decomposed by sensitization from methyl radicals from the ether decomposition. If this were the case we would expect to have the reactionsand again hydrogen atoms by reaction with deutero-acetone would yield HD.The method of investigation seems to have interesting possibilities and to be of wide applicability.

ISSN:1923-4287    

DOI:10.1139/cjr37b-032

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

A partial survey of the Province of Alberta shows that mottled enamel of the teeth in a mild form is endemic in several parts of the province, especially in the area surrounding Lethbridge and in the area south of Red Deer. From an examination of more than 250 samples of water from different parts of the province, a relation has been found to exist between high fluorine in the water supply and the prevalence of mottled enamel.

ISSN:1923-4287    

DOI:10.1139/cjr37b-033

出版商:NRC Research Press    

年代:1937

数据来源: NRC