摘要:

Ultrasonic absorption has been measured in pure butyric acid by a pulse technique from 0 ° to 40 °C. and values of the relaxation frequency obtained. The activation energy of the relaxation process is shown to be 1.1 kcal./mole. These results are compared with published values for acetic and propionic acids and possible relaxation processes are discussed.

ISSN:0008-4042    

DOI:10.1139/v58-164

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Recent work on the mechanism of the anodic dissolution of magnesium is reviewed and additional data on the temperature dependence of the rate of hydrogen evolution at magnesium anodes during electrolysis is given. It is concluded that the results obtained and the literature on this subject are explained more logically by a kinetic mechanism involving initial solution of a univalent magnesium ion followed by subsequent reaction of this ion with water than by postulating self-corrosion with hydrogen evolved at local cathodes.

ISSN:0008-4042    

DOI:10.1139/v58-165

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Dilatometric measurements have been made of the reaction rates in the reversible equilibrium anionic polymerization of α-methylstyrene initiated by sodium naphthalene in tetra-hydrofuran solution, at temperatures of −10°, −40°, and −77°. The kinetic results and measurements made of the viscosity of the polymer conform with the mechanism of the reaction proposed by Szwarcet al., modified by the large degree of reversibility found with this monomer at these temperatures.

ISSN:0008-4042    

DOI:10.1139/v58-166

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Annotinine, C16H21O3N, reacted with phenyl lithium to yield diphenylannotinine, C28H33O3N, containing two hydroxyl functions. Oxidation of diphenylannotinine by the Oppenauer procedure yielded a monohydroxyketone, C28H31O3N, while oxidation with chromic acid yielded a dihydroxyketone, C28H31O4N. A mechanism for the formation of these compounds is discussed in relation to the chemistry of annotinine.

ISSN:0008-4042    

DOI:10.1139/v58-167

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

Rhodium salts react with a solution of tin (II) bromide in hydrobromic acid to produce an intense yellow color suitable for a spectrophotometric determination of rhodium. The method described is relatively simple and is the most sensitive for this metal published to date. Several factors influencing the intensity and stability of the colored species, whose nature is unknown, are described. Since the other platinum metals and base metals interfere it is necessary to isolate the rhodium prior to its determination. However, a fair estimation of rhodium can be made even when equivalent quantities of iridium are present. The procedure may be adapted, with a small loss in sensitivity, to determine rhodium in solutions which have been fumed with sulphuric acid.

ISSN:0008-4042    

DOI:10.1139/v58-168

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The extent of the abnormal recombination of cyanisopropyl radicals to yield the ketenimine intermediate has been investigated at 80 °C. in toluene. It is found that 54.4% of the radicals recombine this way. This value is 75% higher than that reported previously. This result makes it possible to estimate a better value for the molar extinction of intermediate, and suggests the possibility that in the decomposition of the latter both free-radical and molecular processes are co-operative.

ISSN:0008-4042    

DOI:10.1139/v58-169

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

A mass spectrometric study was made of oxygen activated by microwave and by a-c. glow discharge. Appearance potential curves for normal oxygen at masses 16 and 32 indicated the occurrence of multiple electron impact processes. The change in the curves when the oxygen was activated could be interpreted by assuming the presence of O-atoms in the3Pground state, and O2molecules in the1Δgexcited state. No evidence was obtained for the presence of ozone up to pressures of 2 mm. Hg. The recombination coefficient of O-atoms on pyrex was found to be 1.1 × 10−4. Only one oxygen atom in 21 was ionized before recombining in the mass spectrometer ion source. The rate constant for the reaction of O-atoms with N2O is less than 1 × 10−8 cm.3mole−1sec.−1, and several orders of magnitude less than this for the reaction O(3P) + N2O → 2NO. The reaction of O-atoms with NO2was much faster than with NO, but no evidence was found for the formation of NO3.

ISSN:0008-4042    

DOI:10.1139/v58-170

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The reactions of hydrogen atoms with dimethyl- and trimethyl-amines produced mainly methane, together with relatively large quantities of ethane and small amounts of hydrogen cyanide. Dimethylamine was also a product of the trimethylamine reaction.

ISSN:0008-4042    

DOI:10.1139/v58-171

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

An empirical method for predicting standard enthalpies and free energies of formation of isoelectronic molecules bearing in turn the groupings —F, —OH, —NH2, and —CH3is proposed and used. It appears to be accurate to about ±10 kcal. mole−1or better depending on the procedure employed.

ISSN:0008-4042    

DOI:10.1139/v58-172

出版商:NRC Research Press    

年代:1958

数据来源: NRC

摘要:

The infrared spectra of 17 amine hydrohalides have been measured in the solid state, in aqueous solutions, and in their conjugate amine. Their NH+stretching and scissoring bands are discussed.The stretching bands of hydrogen-bonded aliphatic and aromatic amine hydrohalides fall into the same part of the spectrum. In the solid state, the hydrogen bonds are of typeThe aliphatic amine salts usually exhibit many sharp bands, while the aromatic amine salts have broad but composite bands. Tertiary amine salts show a hypsochromic shift in the order hydrochloride, hydrobromide, hydriodide; primary and secondary aliphatic amine salts show a slight bathochromic shift in the same order. Primary and secondary aromatic amine salts behave less regularly, although in most cases the shift is hypsochromic. These facts can be explained qualitatively by considering the charge distribution in the ionized amino groups and the contribution of electrostatic and delocalization effects to the energy of the hydrogen bonds.The anharmonicity of the potential surface which causes the appearance of strong combination bands may lead to the broadening of bands or to many sharp bands. There is no parallelism in this latter case between shift and broadening of the bands.The assignment of a strong band which appears in many cases near 2000 cm−1is discussed.The above-mentioned characteristic band shifting is absent in the spectra of aqueous solutions and it is concluded that in this case hydrogen bonding is not of thebut of thetype.

ISSN:0008-4042    

DOI:10.1139/v58-173

出版商:NRC Research Press    

年代:1958

数据来源: NRC