摘要:

The reduction of chloroform by chromous perchlorate in aqueous solution gave chloropentaaquochromium(III) perchlorate and dichloromethylpentaaquochromium(III) perchlorate in equimolecular amounts.

ISSN:0008-4042    

DOI:10.1139/v59-011

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

A method is described for studying both the surface and homogeneous decay of N atoms in which the atom concentration reaching a reaction vessel after a period of decay is measured as a function of pressure by HCN production from ethylene or ethane under conditions of complete consumption of the atoms and complete initial dissociation of the nitrogen. The results indicated that the surface decay proceeded by a first-order mechanism between 55 °C and 400 °C, with the collision efficiency for an Na2HPO4surface essentially constant at 2.75 × 10−4. The activation energy of surface decay was 1.0 kcal mole−1and the concentration of surface species 1.9 × 1014cm−2. It was concluded that the surface decay probably leads directly to molecules in the ground state.Depending on the temperature and whether or not N2and N were considered equivalent as third bodies, the rate constant of the homogeneous decay varied from 1.09 × 10−33to 13.2 × 10−33cc2molecule−2sec−1. The homogeneous decay therefore appears to have a positive temperature coefficient and to be of only secondary importance below about 2 mm pressure under the prevailing conditions. The similarity ofone-halfthe rate constant of homogeneous decay at 25 °C (0.55 × 10−33to 0.97 × 10−33) to the rate constant of afterglow emission obtained by Berkowitzetal. (2 × 10−33) suggests thatallhomogeneous decay gives rise to afterglow via the5Σ state.

ISSN:0008-4042    

DOI:10.1139/v59-012

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

When tetrachloroethylene is irradiated with Co60gamma rays in the presence of oxygen or air, the main products are trichloroacetyl chloride, phosgene, and oxalyl chloride. The reaction is a chain reaction. Possible reaction mechanisms are discussed.

ISSN:0008-4042    

DOI:10.1139/v59-013

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

A radio tracer method has been used to measure the heat and entropy of association of all the lanthanide ions (except promethium) with the chelating agent EDTA. Entropy terms are largely responsible for the remarkable stability of these complex ions. The results suggest, but do not prove, that a change in configuration of the complex occurs after gadolinium (element 64).

ISSN:0008-4042    

DOI:10.1139/v59-014

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The reaction of organic isothiocyanates with sodium azide in ethanol and water has been investigated. Water is shown to be the more advantageous solvent for this reaction giving higher yields and initially purer 1-substituted-tetrazoline-5-thiones. A series of these latter compounds was made by this procedure. The yield of product appears to be dependent on the electrical properties of the substituent of the isothiocyanate, the yields decreasing as the electron-donating properties increase. A series of new 4-substituted-thiosemicarbazides has been prepared and converted by diazotization to the corresponding 5-(substituted)aminothiatriazoles. A theory to account for the differences in the mode of reaction of hydrazoic acid and azide ion is presented and discussed. The basic conversion of 5-(substituted)aminothiatriazoles to 1-substituted-tetrazolinethiones may involve a simple dearrangement–rearrangement mechanism complicated by side reactions. A summary of known isomeric 5-(substituted)aminothiatriazoles and 1-substituted-tetrazolinethiones is presented.

ISSN:0008-4042    

DOI:10.1139/v59-015

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

3-Amino-5-pyrazolones did not react with guanidine in aqueous solution, but with aldehydes in the presence of piperidine, the amino group was removed in some cases. 5-Pyrazolonoguanidines were synthesized by the direct fusion of 3-amino-5-pyrazolones and dicyandiamide. The infrared spectra of the pyrazolone derivatives prepared are briefly discussed.

ISSN:0008-4042    

DOI:10.1139/v59-016

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v59-017

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v59-018

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v59-019

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

A theoretical treatment has been developed for the rates of electron-transfer reactions in aqueous solution, with particular reference to the ferric–ferrous system. The reactions are considered to be diffusion-controlled processes, the approach of the ions being hindered by the electrostatic repulsion between them. Calculations have been made of the free energy of the diffusion process and for the repulsion, account being taken of the variation in dielectric constant with the electric field. The form of the potential-energy barrier between the ions is calculated for various separations, and the transmission coefficient calculated using the quantum-mechanical expression corresponding to a rectangular barrier. The total free energy of activation for the reaction, which is the sum of the contributions due to diffusion, repulsion, and tunnelling, is found to pass through a minimum at a separation of about 4 Å. The calculated free energy of activation for the reaction is 15.4 kcal, in good agreement with the experimental value of 16.8 kcal. The energy and entropy of activation for the reaction are also briefly discussed.

ISSN:0008-4042    

DOI:10.1139/v59-020

出版商:NRC Research Press    

年代:1959

数据来源: NRC