摘要:

AbstractThe reaction of NO2with C2F4was studied at 30°, 68°, 114°, and 157°C by in situ monitoring the infrared absorption bands of the products. The major primary products of the reaction are O2NCF2CFO and FNO. Smaller amounts of CF2O (and presumably NO) are also produced. There was no evidence for other primary products, though they may have been produced in minor amounts. The rate laws for the production of both O2NCF2CFO and CF2O are first order in both [NO2] and [C2F4]. CF2O production is at least partly heterogeneous as demonstrated by packing the quartz reaction vessel with Pyrex beads and by using a Monel cell. The homogeneous rate constant obtained from the high‐temperature results gives a rate constant of 3.4 × 108exp (minus;17000/RT)M−1sec−1for CF2O production. Actually these Arrhenius parameters represent lower limits, since the heterogeneous reaction may still be playing a significant role. The production rate of O2NCF2CFO is not much affected by changing the nature of the surface or the surface to volume ratio. However the reaction may be heterogeneous, since the rate constant for its formation of 1.3 × 104e×p (−7500/RT)M−1sec−1has an abnormally low pree×ponential factor. E×periments in the presence of NO indicate that the mechanism for O2NCF2CFO formatlon is\documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{l} \begin{array}{*{20}c} {(11)} & {{\rm NO}_{\rm 2} + {\rm C}_{\rm 2} {\rm F}_{\rm 4} \to {\rm O}_{\rm 2} {\rm NCF}_{\rm 2} {\rm CF}_{\rm 2} } \\ \end{array} \\ \begin{array}{*{20}c} {(12)} & {{\rm O}_{\rm 2} + {\rm NCF}_{\rm 2} {\rm CF}_{\rm 2} + {\rm NO}_{\rm 2} \to {\rm O}_{\rm 2} {\rm NCF}_{\rm 2} {\rm CFO} + {\rm FNO}} \\ \end{array} \\ \end{array}$$\end{document}The intermediate can also react with NO:\documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{*{20}c} {(13)} & {{\rm O}_{\rm 2} {\rm NCF}_{\rm 2} {\rm CF}_{\rm 2} + {\rm NO} \to {\rm O}_{\rm 2} {\rm NCF}_{\rm 2} {\rm CF}_{\rm 2} {\rm NO}} \\ \end{array}$$\end{docum

ISSN:0538-8066    

DOI:10.1002/kin.550040602

出版商:John Wiley&Sons, Inc.    

年代:1972

数据来源: WILEY

摘要:

AbstractAn e×tensive table is given of the Kassel integral\documentclass{article}\pagestyle{empty}\begin{document}$$I(S,B,D) = \Gamma \mathop {(S)}\limits^1 \int_0^\infty {\frac{{x^{S - 1} e^{ - x} dx}}{{1 + 10^D \left({\frac{x}{{B + x}}} \right)^{S - 1} }}}$$\end{document}that occurs in the Rice‐Ramsperger‐Kassel theory of unimolecular gas react

ISSN:0538-8066    

DOI:10.1002/kin.550040603

出版商:John Wiley&Sons, Inc.    

年代:1972

数据来源: WILEY

摘要:

AbstractElectron transfer involving triplet molecules of anthraquinone sulfonates has been studied by flash photolysis. It was revealed that semiquinone radicals were formed in one‐electron oxidation of carbonate anions. Absorption spectra and the kinetics of decay transients in aqueous and aqueous‐alcoholic solutions have been stud

ISSN:0538-8066    

DOI:10.1002/kin.550040604

出版商:John Wiley&Sons, Inc.    

年代:1972

数据来源: WILEY

摘要:

AbstractThe thermal decompositions of 1‐chloro‐1‐fluoroethane and 1‐chloro‐1,1‐difluorethane at atmospheric pressure have been studied in the temperature range 500–600°C in a flow system. The dehydrochlorinations are homogenous in a carbonaceous reactor and unimolecular. The rate constants are given by\documentclass{article}\pagestyle{empty}\begin{document}$$k_{\rm I} = 10^{13.94 \pm 0.05} \exp (- 57,015 \pm 200/RT)^{\sec - 1}$$\end{document}and\documentclass{article}\pagestyle{empty}\begin{document}$$k_{{\rm II}} = 10^{14.35 \pm 0.12} \exp (- 60,200 \pm 500/RT)^{\sec - 1}$$\end{document}The criteria for molecular or chain processes in thermal dehydrochlorinations

ISSN:0538-8066    

DOI:10.1002/kin.550040605

出版商:John Wiley&Sons, Inc.    

年代:1972

数据来源: WILEY

摘要:

AbstractStudy ofn‐butane pyrolysis at high temperature in a flow system allows measurement of the sum of the rate constants of the initiation reactions\documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{l} \begin{array}{*{20}c} {(1)} & {{\rm C}_{\rm 4} {\rm H}_{{\rm 10}} \to {\rm 2C}_{\rm 2} {\rm H}_{\rm 5} ^{\rm .} } \\ \end{array} \\ \begin{array}{*{20}c} {(2)} & {{\rm C}_{\rm 4} {\rm H}_{{\rm 10}} \to {\rm CH}_{\rm 3} ^{\rm .} } \\ \end{array} + {\rm C}_{\rm 3} {\rm H}_{\rm 7} ^{\rm .} \\ \end{array}$$\end{document}and of the Arrhenius parameters of the reactions\documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{l} \begin{array}{*{20}c} {(3)} & {{\rm CH}_{\rm 3} ^{\rm .} + {\rm C}_{\rm 4} {\rm H}_{{\rm 10}} \to {\rm CH}_{\rm 4} + {\rm C}_{\rm 4} {\rm H}_{\rm 9} ^{\rm .} } \\ \end{array} \\ \begin{array}{*{20}c} {(4)} & {{\rm C}_{\rm 2} {\rm H}_{\rm 5} ^{\rm .} + {\rm C}_{\rm 4} {\rm H}_{{\rm 10}} \to {\rm C}_{\rm 2} {\rm H}_{\rm 6} } \\ \end{array} + {\rm C}_{\rm 4} {\rm H}_{\rm 9} ^{\rm .} \\ \end{array}$$\end{document}Established data fork1/k2allow estimation ofk1for 951°K and this, with recent thermochemical data, yields the result logk−1(l.mole s−1) = 8.5, in remarkable agreement with a recent measurement [20] but over si×ty times smaller than conventional assumption. The productk3k4(l.2mole−2s−2) is found to be associated with the Arrhenius parameters log (A3A4) = 21.90 ± 0.6 and (E3+ E4) = 38.3 ± 2.7 kcal/mole. These values are much higher than would be e×pected on the basis of low temperature estimates. Independent evaluation gives logA4= 10.5 ± 0.4 (l.mole−1s−1) andE4= 20.1 ± 1.7 kcal/mole, hence logA3= 11.4 ± 0.8 (l.mole−1s−1) andE3= 18.2 ± 3.2 kcal/mole. These values are shown to be entirely consistent with a wide range of results from pyrolytic studies, and it is argued that they further confirm the view that Arrhenius plots for alkyl radical–alkane metathetical reactions are strongly curved, in part due to tunneling and, appreciably, to other as yet unidentified effects. Since there is published evidence that metathetical reactions involving hydrogen atoms show even greater curvature, it is suggested that this may be a characteristic of

ISSN:0538-8066    

DOI:10.1002/kin.550040606

出版商:John Wiley&Sons, Inc.    

年代:1972

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550040601

出版商:John Wiley&Sons, Inc.    

年代:1972

数据来源: WILEY