摘要:

AbstractThe rate constants of peroxy radical recombination in the oxidation of 1‐methyl‐3‐phenylindan, 1,3‐dimethyl‐3‐phenylindan, and 1,1‐dimethyl‐3‐phenylindan were measured using the nonstationary‐state technique. A cooxidation method was applied to obtain the reactivities of these compounds with respect to α‐pheny

ISSN:0538-8066    

DOI:10.1002/kin.550130202

出版商:John Wiley&Sons, Inc.    

年代:1981

数据来源: WILEY

摘要:

AbstractThe reactivity of amines towardstert‐butoxy radicals depends upon the amine ionization potential and the solvent, indicating that polar structures contribute to the reactivity of these compounds. Nevertheless, the dependence with the amine potential is smaller than the one obtained for the quenching of carbonyl excited states by amines and other factors as the strength of the broken hydrogen bond and steric hindrance are also significant in determining the rate of the proces

ISSN:0538-8066    

DOI:10.1002/kin.550130203

出版商:John Wiley&Sons, Inc.    

年代:1981

数据来源: WILEY

摘要:

AbstractA new method of theoretical prediction of the kinetic rate constants of fast chemical reactions in solutions is presented. It takes into account the effect of finite diffusive displacements of the reacting molecules. The approach is based on the solution of the steady‐state Fokker–Planck equation by the moments method of Grad developed in the theory of coagulation of aerosol particles. A comparison of the predicted rate constants with the experimental data provided by Schuh and Fischer for the self‐reaction oftert‐butyl radicals inn‐alkanes shows a good corre

ISSN:0538-8066    

DOI:10.1002/kin.550130204

出版商:John Wiley&Sons, Inc.    

年代:1981

数据来源: WILEY

摘要:

AbstractThe rate of the cerium (IV) oxidation ofp‐chloromandelic acid has been studied in perchlorate media at an ionic strength of 1.50 mol/dm3by the stopped‐flow technique and in H2SO4MHSO4(M+= Li+, Na+, K+) and H2SO4MClO4(M+= H+, Li+, Na+) mixtures at constant total electrolyte concentrations of 1.00 and 2.00 mol/dm3using the conventional spectrophotometric method. In perchlorate media the kinetic data indicate the formation of two intermediate complexes between cerium (IV) and the organic substrate, but only one is significantly involved in the intramolecular electron‐transfer process. The oxidation rate is markedly lower in sulfate media, where two reaction paths have been found to contribute to the overall redox reaction. The univalent cations examined exhibit negative specific effects upon the overall oxidation rate increasing in the order H+

ISSN:0538-8066    

DOI:10.1002/kin.550130205

出版商:John Wiley&Sons, Inc.    

年代:1981

数据来源: WILEY

摘要:

AbstractOverall and detailed kinetic descriptions of the pyrolysis of C3H8have been proposed as a result of a turbulent flow reactor investigation in the temperature range of 1110–1235 K and at atmospheric pressure. The overall reaction was described by a first‐order rate expression with an activation energy of 58.65 kcal/mol and a preexponential factor of 3.2 × 1012sec−1. This expression agrees with previously reported rate data. In addition, a kinetic mechanism involving 13 chemical species and 32 elementary reactions has been postulated to describe the kinetics. Experimental data from the present flow reactor experiments and from static vessel and shock tube experiments reported in the literature were used to verify the mechanism. Agreement over the temperature range of 800–1400 K and over the pressure range of 0.1–8.5 atm was obtained by adjusting three rate constants. Previously reported values for these rate constants appear to require reexamination. The reactions in question are the following:The sum of the rate constants for reactions (2a) and (2b) and the rate constant for reaction (23) are best represented by\documentclass{article}\pagestyle{empty}\begin{document}$$ k_{2a} + k_{2b} = 10^{- 0.1} T^4 \exp (-8300/{\rm RT}){\rm cm}^3 /{\rm mol}\;{\rm sec} $$\end{document}and\documentclass{article}\pagestyle{empty}\begin{document}$$ k_{23} = 10^{14.55} \exp (-14,340/{\rm RT}){\rm cm}^3 /{\rm mol}\;{\rm sec} $$\end{document}which differ with the expressions in the

ISSN:0538-8066    

DOI:10.1002/kin.550130206

出版商:John Wiley&Sons, Inc.    

年代:1981

数据来源: WILEY

摘要:

AbstractTwo‐parameter equation correlations are reported for radical reactions of aromatic compounds. In these correlations polar and resonance substituent constants identical with the substituent constants of aliphatic compounds were used. The equations correlate the rate constants for H abstraction reactions and for the addition of a variety of free radicals to theortho‐,meta‐, andpara‐substituted aromatic compounds. Besides, they correlate parameters of the spectra for substituted aromatic radicals. The correlations show that the effects ofparasubstituents on the reactions studied are nearly entirely resonance effects, whereas for themeta‐ andortho‐substituted compounds polar (inductive) effects become essential. Application of the two‐parameter correlations permits also to determine the structure of transition states (σ or π‐complex) in free

ISSN:0538-8066    

DOI:10.1002/kin.550130207

出版商:John Wiley&Sons, Inc.    

年代:1981

数据来源: WILEY

摘要:

AbstractThe rates of several novel elementary reactions involving ClO, BrO and SO free radicals in their ground states were studied in a discharge‐flow system at 295 K, using mass spectrometry. The rate constantk2was determined from the decay of SO radicals in the presence of excess ClO radicals:\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm SO} + {\rm ClO} \to {\rm SO}_{\rm 2} + {\rm Cl;}} & {k_{\rm 2} = (2.3{\rm } \pm {\rm 0}{\rm .6}) \times 10^{ - 11} {\rm cm}^3 \sec ^{ - 1} } \\ \end{array}$$ \end{document}The SO + OClO overall reaction has a complex mechanism, with the primary step having a rate constantk5equal to (1.9 ± 0.7) × 10−12cm3sec−1:\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm SO} + {\rm OClO } \to {\rm SO}_{\rm 2} + {\rm ClO} $$\end{document}A lower limit for the rate constant of the rapid reaction of SO radicals with BrO radicals was determined:\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm SO} + {\rm BrO} \to {\rm SO}_{\rm 2} + {\rm Br;}} & {k_{17} } \\ \end{array} \ge 4 \times 10^{ - 11} {\rm cm}^3 \sec ^{ - 1} $$\end{d

ISSN:0538-8066    

DOI:10.1002/kin.550130208

出版商:John Wiley&Sons, Inc.    

年代:1981

数据来源: WILEY

摘要:

AbstractResults on the oxidation of N 3−by Br2in neutral and acid media are presented. The rate of the reaction is found to be proportional to [N 3−] and [Br2]. The gaseous product of oxidation is found to be pure nitrogen. The stoichiometry of the reaction is\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm Br}_2 + 2{\rm N}_{\rm 3}^ - \to 2{\rm Br}^ - + 3{\rm N}_{\rm 2} {\rm ([N}_{\rm 3}^ -]) > [{\rm Br}_2] $$\end{document}The reaction shows a positive salt effect. It is found that the addition of Br−stabilizes the complex BrN3, which decomposes into Br−and N2:\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm Br}_2 + {\rm N}_{\rm 3}^ - \rightleftharpoons {\rm BrN}_{\rm 3} + {\rm Br}^ - } \\ {{\rm BrN}_3 + {\rm N}_{\rm 3}^ - \to {\rm Br}^ - + 3{\rm N}_{\rm 2} } \\ \end{array} $$\end{document}The spectroscopic measurements also support the kinetic observation. The equilibrium constantK, the rate constants and the thermodynamic parameters were calculated. It is observed that H+ion inhibits the reaction. The mechanism is discussed in terms of the kine

ISSN:0538-8066    

DOI:10.1002/kin.550130209

出版商:John Wiley&Sons, Inc.    

年代:1981

数据来源: WILEY

摘要:

AbstractBy measuring the rates of decay of ozone in a large excess of reactant, second‐order rate constants have been obtained for the reactions of ozone with ethene, propene, but‐1‐ene,trans‐but‐2‐ene, isobutene, hex‐1‐ene, cyclopentene, cyclohexene, isoprene, vinyl fluoride, 1,1‐difluoroethene,cis‐1,2‐difluoroethene,trans‐1,2‐difluoroethene, trifluoroethene, tetrafluoroethene, and 2,5dihydrofuran. The reactions have been studied in synthetic air at atmospheric pressure and at temperatures of 294 and 260 K. The rate constants and Arrhenius parameters are discussed in relation to existing kinetic dat

ISSN:0538-8066    

DOI:10.1002/kin.550130210

出版商:John Wiley&Sons, Inc.    

年代:1981

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550130201

出版商:John Wiley&Sons, Inc.    

年代:1981

数据来源: WILEY