摘要:

The kinetics of formation of anodic oxide films on different crystal faces of single crystal indium antimonide have been investigated by measurements of charge passed, capacitance, and optical properties. Below a transition or breakdown region of voltage no difference in kinetics was found. Above this voltage a marked difference appeared. The transition voltage was found to depend on both the crystal face and the current density at which the film was formed.

ISSN:0008-4042    

DOI:10.1139/v66-089

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The formation of the protactinium complexes with malic, tartaric, trioxyglutaric, oxalic, aconitic, citric, and ethylenediaminetetraacetic acids has been studied by the ion-exchange method, and the instability constants have been calculated. The stability of the complexes increases in the following order: aconitic, malic, tartaric, oxalic, trioxyglutaric, citric, ethylenediaminetetraacetic acid.

ISSN:0008-4042    

DOI:10.1139/v66-090

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The miscibility gap in the binary system: Al–In has been investigated and the critical temperature and composition estimated as 945 °C and 68.8% In, 31.2% Al (by weight).The liquid–liquid partial miscibility region of the ternary system has also been determined. The lowest temperature at which two liquids can exist in equilibrium before a third (solid) phase appears was found to be approximately 590°. At this temperature, the ternary gap extends to 30.5% Ag, 34.7% Al, and 34.8 In. Isotherms of the ternary gap are given for 50° intervals between 650° and 900°. A true ternary critical point does not exist, i.e. the binary critical temperature is lowered continuously by addition of silver.

ISSN:0008-4042    

DOI:10.1139/v66-091

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The rate coefficients for the acid-catalyzed esterification in methanol at 35.0° of fourteen 3-substituted acrylic acids have been determined. Rate coefficients have also been determined for the alkaline hydrolysis in 70% v/v dioxin–water at 18.8° of 13 methyl esters and the carbonyl-stretching frequencies of the esters have been examined. The effect oftrans-substitution is assessed by use of the Hammett equation. In the alkaline hydrolysis, the transmission of polar effects is approximately 1.9 that of the meta- and para-substituted benzoates. An analysis of the steric effects in thecis-isomers in both reactions shows that the steric effects of the halogeno-substituents in the two reactions differ and an explanation is offered. The application of the Taft–Ingold equation to ortho-substituted benzoates is criticized. The carbonyl-stretching frequencies of thecis-halogeno-esters exhibit a shift of +8 cm−1compared with thetrans-isomers; this shift is attributed to an electrostatic effect.

ISSN:0008-4042    

DOI:10.1139/v66-092

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The prediction, based on earlier studies of the ruthenium(III) chloride catalyzed oxidation of H2by iron(III), that in the absence of iron(III) or other oxidants ruthenium(III) chloride should catalyze homogeneously the isotopic exchange between D2and H2O has been confirmed. A kinetic study was made of this exchange reaction in which the dependence of the exchange rate and of the exchange product distribution (HD:H2ratio) on the concentrations of ruthenium(III), hydrogen ion, and chloride ion were determined. The results, and in particular the observation that the HD:H2ratio of the exchange product increases with the concentrations cf H+and Cl−, support the view that the ruthenium (III)-catalyzed oxidation of D2by iron(III) and the D2–H2O exchange reaction proceed through related mechanisms involving a common rate-determining step in which D2is split heterolytically and a deuteridoruthenium(III) complex is formed.

ISSN:0008-4042    

DOI:10.1139/v66-093

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The aim of this work was to explore the effect of α-methylation on the reactivity and detailed mechanism of hydrolysis. Accordingly, rate data and derived parameters are given for the hydrolysis of a series of halides and sulfonates in water. From the differences in kinetic parameters, an attempt is made to infer further information relating structure and mechanism.

ISSN:0008-4042    

DOI:10.1139/v66-094

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Rate data and derived parameters for the hydrolysis of a series of para-substituted methyl benzenesulfonates are given. The introduction of such substituents has negligible effect on ΔCp≠, and the difference in rate is largely reflected in δXΔS≠.

ISSN:0008-4042    

DOI:10.1139/v66-095

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Calculations are presented for the equilibrium tritium isotope effect involving water, hydronium ion, and hydroxide ion. The results are used to predict the kinetic isotope effect in the transfer of protons to a mercury cathode.

ISSN:0008-4042    

DOI:10.1139/v66-096

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The low temperature polymerization of allyl acrylate in toluene solution has been investigated withn-butyllithium and 1,1-diphenyl-n-hexyllithium initiators. The latter was also used in a study of the polymerization of allyl methacrylate under the same conditions. The reactions between initiator and monomer were rapid in all cases. More than half of the initiator molecules reacted with monomer acrylic double bonds to start polymer chains, only a few of which grew to a high molecular weight, highly isotactic product. Most of the chains remained as a low molecular weight, precipitant-soluble product. The remaining initiator molecules reacted with the carbonyl groups of the monomers to produce species which could be detected as allyl alcohol, after termination of the reaction with acetic acid. The allyl double bonds were not involved in reactions during polymerization but were presumably responsible for the cross-linking which occurred when the polymers were exposed to air.

ISSN:0008-4042    

DOI:10.1139/v66-097

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

When sodium azide is irradiated with ultraviolet light the rate of photolysis at first decreases and then becomes constant. Two reaction mechanisms are involved: the first occurs only in salt which has not previously been irradiated, whereas the second requires the presence of metallic sodium. These two reactions are interpreted as the formation and linear growth of nuclei in the dislocation network of the salt and an equation developed from this model gives good agreement with the experimental results. Incorporation of Fe3+ions in NaN3leads to a greater number of nucleus-forming sites.

ISSN:0008-4042    

DOI:10.1139/v66-098

出版商:NRC Research Press    

年代:1966

数据来源: NRC