摘要:

The preparation of the three crystalline potassium salts of fumaric acid, "acid" potassium hydrogen fumarate (2KHC4H2O4.H2C4H2O4), potassium hydrogen fumarate (KHC4H2O4), and dipotassium fumarate dihydrate (K2C4H2O4.2H2O), is discussed, and suitable pH values for the growth of single crystals of each are given. Unit cell, space group, and X-ray diffraction powder identification data for the three salts are presented.

ISSN:0008-4042    

DOI:10.1139/v61-227

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

The solubilities of anhydrous CaSO4and CaSO4.2H2O in concentrated aqueous solutions of NaCl at a series of temperatures—25 °C, 30 °C, 40 °C, and 50 °C, have been determined. It was found that the transition temperature for the reactionwhich in pure water has a value of 42 °C, is shifted progressively to lower temperatures with increasing NaCl concentration. It was also found that the variation of the transition temperature with NaCl concentration could be adequately represented by the equationwhere ΔG, ΔH, and ΔSare the Gibbs free energy, enthalpy, and entropy of the reaction andP0andPare the vapor pressures of pure water and the solution respectively at the absolute temperatureT.

ISSN:0008-4042    

DOI:10.1139/v61-228

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

From the kinetics of the reaction of ethylene oxide with aqueous ethanol and methanol, catalyzed by perchloric acid, the relative basicities of water, methanol, and ethanol have been determined. The value ofK1in the expressionhas been found to be 1.2 × 102for methanol and 2.1 × 102for ethanol, in good agreement with previous values.

ISSN:0008-4042    

DOI:10.1139/v61-229

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

A statistical evaluation of the empirical linear correlations of infrared group frequencies and band intensities in aliphatic and benzene derivatives with substituent constants has been carried out. The correlations of frequencies with substituent constants generally give low standard deviations and acceptable correlation coefficients, and may thus be employed for the estimation of substituent constants. The correlations of band intensities with substituent constants show an interesting trend of the sign and magnitude of the slopes (ρ values) with the electrical property of the bond or group involved in the vibration. The ρ value decreases with the increasing electron-withdrawing power of the group.

ISSN:0008-4042    

DOI:10.1139/v61-230

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

Methyl 4,6-O-benzylidene-2-benzylthio-2-deoxy-α-D-altropyranoside and methyl 4,6-O-benzyldene-3-benzylthio-3-deoxy-α-D-altropyranoside have been prepared by the reaction of sodium benzylmercaptide with methyl 2,3-anhydro-4,6-O-benzylidene-α-D-allopyranoside and methyl 2,3-anhydro-4,6-O-benzylidene-α-D-mannopyranoside respectively.These two thio ethers were successfully reduced by sodium in liquid ammonia to methyl 2-deoxy-2-mercapto-α-D-altropyranoside and methyl 3-deoxy-3-mercapto-α-D-altropyranoside. An attempted replacement of the tosyl group in 1,2;5,6-di-O-isopropylidene-3-O-tosyl-α-D-glucofuranose by benzyl mercaptan was unsuccessful.

ISSN:0008-4042    

DOI:10.1139/v61-231

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

The variation of the hydrogen yield with the composition of binary gaseous mixtures containing cyclohexane and benzene, cyclohexene, or propylene is qualitatively similar to that in the liquid phase.The quantitative experimental data were tested against several possible reaction mechanisms and two mechanisms gave straight-line plots.One mechanism involved scavenging of hydrogen atoms. The values of the kinetic parameters derived from this mechanism might not be unreasonable in the mixtures of cyclohexane with cyclohexene or propylene. The values for benzene, however, seem less likely.The second mechanism involved the transfer of energy (excitation or ionization) from cyclohexane to the second substance. The values of the ratio of the rate constants,k7/k6, of the reactionsis about 103times greater in the gas than in the liquid phase. Consideration of possible detailed mechanisms of reactions [6] and [7] indicates that this difference is reasonable if C6H12** is a positive ion rather than an excited molecule.

ISSN:0008-4042    

DOI:10.1139/v61-232

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

After excitation by 3130-Å light the anion of 1-naphthoic acid in ethanol solution internally converts to the triplet form of the acid. The excited-state equilibrium can be shifted by the addition of a base or an acid. Numerous total emission spectra of 1-naphthoic acid in various solvents can be understood in terms of some well-established principles governing non-radiative energy transfer processes within and between complex molecules.No quantitative equilibrium studies are presented. The results indicate that the lowest excited states of the acid, singlet and triplet, are of π,π* character. The lowest excited singlet state of the anionic form is most probablyn,π*, while the lowest triplet level is π,π*.

ISSN:0008-4042    

DOI:10.1139/v61-233

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

The previously made absorption-band assignment (1) for the C=S stretching mode in xanthate-type compounds, 1020–1070 cm−1, has been confirmed by the characteristic behavior of the C=S dipole in a range of different solvents (Bellamy and Rogasch (2)).

ISSN:0008-4042    

DOI:10.1139/v61-234

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

It has been shown that nitroguanidine, nitriminoimidazolidine, and 1-benzyl-2-nitriminoimidazolidine behave like urea by formation of potassium salts which completely hydrolyze in water. By contrast to true primary nitramines with which they might be considered to be tautomeric, the nitrimines are classed like urea as practically neutral compounds. Despite this ostensible tautomerism which was formerly evoked to explain the survival of nitroguanidine and nitriminoimidazolidine in alkaline solution it is now believed that the salts of nitroguanidine and nitraminoimidazolidine, from which the original nitrimines are regenerated upon acidification, are not intermediates, but rather end products, in the slow reaction with alkali. The intermediate is now postulated as an hydroxyisonitraminate anion from which the several products of the reaction are formed by appropriate fission. Presumably this anionic intermediate also is operative when tetraethylnitroguanidine or 1,3-dibenzyl-2-nitriminoimidazolidine is converted by alkali into tetraethylurea and 1,3-dibenzyl-2-inuclazolidine respectively.

ISSN:0008-4042    

DOI:10.1139/v61-235

出版商:NRC Research Press    

年代:1961

数据来源: NRC

摘要:

Methylation ofL-arabinose diethyl mercaptal in tetrahydrofuran with methyl iodide and silver oxide yielded mainly 2-O-methyl-L-arabinose and a trace of 5-O-methyl-L-arabinose. The identity of the major component was inferred by its behavior on electrophoresis and confirmed by the preparation of the crystalline amide. The polymethylated components were not examined. 2-O-Methyl-L-arabono-γ-lactone, previously known as a sirup, has now been obtained crystalline.

ISSN:0008-4042    

DOI:10.1139/v61-236

出版商:NRC Research Press    

年代:1961

数据来源: NRC