摘要:

The syntheses ofL-α-monomesylin,D-α,β- andDL-α,β-dimesylin, and trimesylin are described and some of their physical properties are reported. It was observed that the optical rotations ofL-α-monomesylin andD-α,β-dimesylin in pyridine solutions change with time, whereas the rotations of the same compounds in the sterically hindered base, 2,6-lutidine, remain constant. Of the two previously reported values for the refraction of the –O–SO2– group the value of Tasker and Purves was confirmed. The mono- and dimesylins form the starting materials for the syntheses of the diacylL-α-monomesylins and the acylD-α,β-dimesylins.

ISSN:0008-4042    

DOI:10.1139/v51-092

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

As part of a general program concerning the synthesis of the enantiomeric forms of asymmetrically substituted glycerol derivatives, dipalmitoyl and distearoylL-α-monomesylin, and palmitoyl and stearoylD-α,β-dimesylin were prepared. With the exception of stearoylD-α,β-dimesylin, each of the mixed acid triglycerides was synthesized by two independent procedures. The individual triglyceride, regardless of the method of synthesis, was obtained with the same rotation, thus assuring the optical purity not only of the mixed acid triglycerides but also ofL-α-monomesylin andD-α,β-dimesylin.

ISSN:0008-4042    

DOI:10.1139/v51-093

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

Ceric ion has been shown to exist in perchloric acid solution as a mixture of Ce4+, CeOH3+, and a dimer, probably (Ce-O-Ce)6+. From a spectral study between 395 and 430 mμ, the values of the equilibrium ratios have been determined, along with the molar extinction coefficients of each ion over this region of wave length. The thermodynamic quantities ΔH, ΔF°, and ΔS° have been determined for each reaction.

ISSN:0008-4042    

DOI:10.1139/v51-094

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

Ceric ion has been shown to associate with sulphate ion to form successively Ce(SO4++, Ce(SO4)2, and Ce(SO4)3−. The association constants relating these species have been determined at 25 °C. The molar extinction coefficients of each associated complex have been found between 395 and 430 mμ. Migration experiments bear out the results qualitatively.

ISSN:0008-4042    

DOI:10.1139/v51-095

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

A method for preparing sodium stearate by the action of sodium amalgam with stearic acid under moisture free conditions is described. From the similar density–temperature behavior of these samples and those prepared by titration of stearic acid followed by meltinginvacuo, it is concluded that melting under low pressure completely removes the water associated with the sodium ion in soaps.

ISSN:0008-4042    

DOI:10.1139/v51-096

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

Thirteen 3-amino-5-pyrazolones substituted only in position 4 have been synthesized from the corresponding mono- or disubstituted cyanoacethydrazides or cyanoacetic esters in alkaline medium. Their ultraviolet light absorption spectra have been determined in neutral and acid solutions.

ISSN:0008-4042    

DOI:10.1139/v51-097

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

The effects of a velocity gradient upon the dielectric constant were studied in solutions of macromolecules, in suspensions and in liquid crystals. Decreases in dielectric constant under shear were observed for polar polymers in polar and nonpolar solvents. For solutions of ethyl cellulose an increase in dielectric constant was obtained. Nonpolar polymers showed no changes of dielectric constant under shear. Large changes in dielectric constant at low rates of shear were observed in carbon black suspensions. The experimental results are discussed on the basis of particle orientation in a velocity gradient and in an electric field.

ISSN:0008-4042    

DOI:10.1139/v51-098

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

The rate of the condensation of an uncatalyzed, equimolecular solution of resorcinol and formaldehyde in water was determined at 60°C. By replacing a portion of the water in this system with aliphatic alcohols, a reduction in the rates of condensation was noted at the same temperature. However, these reaction rates were found to vary widely among themselves, depending on the alcohol used. These results are explained under the assumption of the intermediate formation of hemiacetals from the free formaldehyde and the alcohols. The retarding effect of these alcohols on the resorcinol–formaldehyde condensation is inversely related to their different tendency to form esters with acids, or acetals with aldehydes, as reported by other authors. The general importance of the formation of hemiacetals is emphasized where formaldehyde is applied in the presence of alcohols.

ISSN:0008-4042    

DOI:10.1139/v51-099

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

The condensation of resorcinol and formaldehyde in aqueous alcohols and dioxane is interpreted on the basis of competing electrophilic reactions of the hydroxymethyl carbonium ion with the resorcinol aromatic ring and with the oxygen atoms of the resorcinol and the solvents. The reaction of the carbonium ion and the alcohol groups leads to oxonium ions which may then form hemiacetals.

ISSN:0008-4042    

DOI:10.1139/v51-100

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

The fatty acid composition of the oil from Argentine rapeseed grown in Western Canada was investigated by converting the glyceride esters to methyl esters and distilling the latter in a Podbielniak Heligrid distillation column. Analyses of the fractions showed 6 to 10% more eicosenoic acid and 7 to 10% less erucic acid than was previously reported for rapeseed oils.

ISSN:0008-4042    

DOI:10.1139/v51-101

出版商:NRC Research Press    

年代:1951

数据来源: NRC