摘要:

The Arrhenius parameters of some 20 reactions, in which different atoms and radicals attack methane, have been compared in the light of the thermochemistry of the reactions. Attention has been focussed on family relationships amongst the attacking species.Where direct kinetic data are lacking, Arrhenius parameters have been calculated from data available for the reverse reactions.

ISSN:0008-4042    

DOI:10.1139/v67-060

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Phosgene has been identified by infrared spectroscopy as one of the major products of both continuous and flash photolyses of dilute, oxygenated CCl4solutions of six α,β-unsaturated ketones at wavelengths longer than 3 000 Å. This product is absent from degassed solutions photolyzed similarly. Acetone, benzophenone, naphthalene, and anthracene show parallel behaviour.s-transketones appear to be more effective in causing the CCl4decomposition than thes-cisspecies. The photosensitized decomposition of CCl4is a possible mechanism for this common behavior.

ISSN:0008-4042    

DOI:10.1139/v67-061

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The preparation and partial characterization of some new complexes of gallium(III) and indium(III) halides with triphenylphosphine, tri-p-tolylphosphine, and tri-p-methoxyphenyl-phosphine are described. Complexes of gallium(III) halides with the chelating diphosphine l,2-bis(diphenylphosphino)ethane are also described. Conductivity and infrared spectral measurements have been used to interpret the stereochemistry of these compounds.

ISSN:0008-4042    

DOI:10.1139/v67-062

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Crystals of thioformaldehyde trimer, (CH2S)3are orthorhombic, space group Pmn21with a = 7.697 Å, b = 7.067 Å, c = 5.323 Å. There are two molecules in the unit cell with sulfur and carbon atoms in positions (4b) and (2a). The atomic parameters for sulfur and carbon have been determined from a three-dimensional analysis using observed and calculated differential syntheses with isotropic temperature factors. No absorption corrections were applied to the intensity data and no attempt has been made to establish the hydrogen positions. The final discrepancy index is R = 0.093. The molecule has the chair configuration and shows no significant difference between the lengths of any S—C bonds. The mean S—C bond distance is 1.818 Å and the standard deviation of the mean is 0.003 Å. This value is in good agreement with the commonly accepted value of 1.817 ± 0.005 Å for the S—C paraffinic bond.

ISSN:0008-4042    

DOI:10.1139/v67-063

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The densities of aqueous solutions of the homologous salts RNH3Br, where R varies from H ton-octyl, have been measured at 25 °C to the sixth decimal place by a float method. From this series, it is possible to study the transition in behavior of typical simple salts to long-chain micellar salts. The apparent molal volumes extrapolated to infinite dilution can be used to evaluate the additivity of the volume of the methylene groups. The concentration dependence of the apparent molal volumes and the change in volume during micelle formation can be interpreted in terms of a competition between the increase in ice-likeness of water and loss of free space near the solute during hydrophobic hydration. The present results show no indications of dimerization of the cations below the critical micelle concentration.

ISSN:0008-4042    

DOI:10.1139/v67-064

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

A mass-spectrometric stirred-reactor technique was used to study the reaction of atomic oxygen with methane with low concentrations of molecular oxygen. An overall rate constant for oxygen-atom disappearance due to added methane was obtained for the temperature range 375 to 576°K. This rate constant was 4 × 1014exp (− 10 000/RT) cm3mole−1s−1and was compared with a previous rate constant for this reaction that had been measured in the presence of a large excess of molecular oxygen. This comparison showed that the presence of an excess of molecular oxygen produced a considerable increase in oxygen-atom consumption at low temperatures, but only a small increase at high temperatures. From product analyses, the stoichiometry of the reaction could be approximately represented byFrom the reaction stoichiometry and the rate constant for the oxygen-atom disappearance, the rate constant for methane disappearance was calculated to be 1 × 1014exp (− 10 000/RT) cm3mole−1s−1. The presence of excess molecular oxygen has very little effect on this rate constant, contrary to the result found for the disappearance of atomic oxygen.

ISSN:0008-4042    

DOI:10.1139/v67-065

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

An approximation is suggested for calculating the third virial cross-coefficientCijkfrom available generalized tables for pure-component third virial coefficientsCiiiwhich are based on any one of several, spherically symmetric potential functions. A comparison of calculated results with the very limited experimental data now available indicates that the suggested approximation can reproduce the experimental results essentially within the probable (large) experimental uncertainty.

ISSN:0008-4042    

DOI:10.1139/v67-066

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The reaction between diarsines and disulfides to give compounds containing As—S bonds has been further investigated. Compounds with S—S bonds are cleaved by (CH3)2AsH and HCl. CF3SCl cleaves diarsines. Compounds with As—S bonds are cleaved by CF3SCl and (CH3)2AsH. New compounds obtained are C6H5SAs(CH3)2, C6H5SSCF3, CH3SSCF3, and C2H5SCH3.

ISSN:0008-4042    

DOI:10.1139/v67-067

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

A high temperature solution calorimeter of a novel design has been developed whereby the separated components are brought together and mixed within a completely enclosed, vacuum-sealed cell. The instrument consists of an inner spherical compartment containing the reaction cell, surrounded by a number of concentric spherical shells made of Inconel alloy. The calorimeter may be operated at temperatures up to 1 200 °C. The temperature-sensing circuit includes a differential thermopile, a d-c. microvolt amplifier, and a recording millivoltmeter. With this instrument calorific effects of the order of 0.1 cal could be detected.

ISSN:0008-4042    

DOI:10.1139/v67-068

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Ionic, fully fluorinated, ethoxides,n-propoxides, isopropoxides, andn-butoxides of the heavier alkali metals may be made by the reaction of the appropriate acyl fluoride, or of hexafluoroacetone, with the metal fluoride. Factors affecting the stability and possible synthetic use of such compounds are discussed, together with n.m.r. (nuclear magnetic resonance) and infrared spectral data.

ISSN:0008-4042    

DOI:10.1139/v67-069

出版商:NRC Research Press    

年代:1967

数据来源: NRC