摘要:

AbstractThe heat of formation of benzophenone oxide, Ph2CO2, was measured using photoacoustic calorimetry. The enthalpy of the reaction Ph2CN2+ O2→ Ph2CO2+ N2was found to be −48.0 ±0.8 kcal mol−1and ΔHf(Ph2CN2) was determined by measuring the reaction enthalpy for Ph2CN2+ EtOH → Ph2CHOEt + N2(−53.6 ±1.0 kcal mol−1). Taking ΔHf(PhCHOEt) = −10.6 kcal mol−1led to ΔHf(Ph2CN2) = 99.2 ± 1.5 kcal mol−1and hence to ΔHf(Ph2CO2) = 51.1 ± 2.0 kcal mol−1. The results imply that the self‐reaction of benzophenone oxide i.e., 2Ph2CO2→ 2Ph2CO + O2is exot

ISSN:0538-8066    

DOI:10.1002/kin.550210302

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe canonical formalism of the statistical adiabatic channel model is used to calculate limiting high pressure rate constants for the H + CH3→ CH4recombination reaction on a recently reported analytic potential energy surface based onab initiocalculations. An effective adiabatic channel potential which incorporates theGϕϕmatrix element of the twofold degenerate H3CH transitional bending mode, quartic anharmonicity, and state selected mode coupling effects is implemented. The rate constants calculated over the temperature range 200–1000 K are in very good agreement with recent canonical variational transition state theory calculations performed on the same surface. The comparison with experimental results is also di

ISSN:0538-8066    

DOI:10.1002/kin.550210303

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

Abstract2‐Methylbut‐1‐ene‐3‐yne and Propyne mixtures were pyrolyzed at 350–450°C in the absence and presence of O2and NO. The major product of the reaction is a polymer, butm‐xylene andp‐xylene are also produced and were studied as the species of interest. The C8H10formation rate is first‐order in C3H4and C5H6. The rate coefficient is best fitted by\documentclass{article}\pagestyle{empty}\begin{document}$$\log [k({\rm C}_{\rm 8} {\rm H}_{{\rm 10}}),M^{ - 1} s^{ - 1}] = (11.2 \pm 1.0) - (166 \pm 13)/2.3RT$$\end{document}though it is not inconsistent with\documentclass{article}\pagestyle{empty}\begin{document}$$\log [k({\rm C}_{\rm 8} {\rm H}_{{\rm 10}}),M^{ - 1} s^{ - 1}] = (8.17) - (125.9)/2.3RT$$\end{document}whereRis the ideal gas constant in kJ/mol‐K. Experiments in the presence of NO show thatm‐xylene andp‐xylene formation occur by two processes: a concerted molecular mechanism (≃ 41%) and a singlet d

ISSN:0538-8066    

DOI:10.1002/kin.550210304

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe pyrolysis kinetics of the title compounds has been studied in a stirred‐flow reactor over the temperature range 440–530°C and pressures between 5 and 14 torr. Benzylt‐butyl sulfide and phenylt‐butyl ether formed isobutene as product in over 98% yield, together with the corresponding benzyl thiol and phenol. The benzyl thiol decomposes to a large extent into hydrogen sulfide and bibenzyl. In the pyrolysis of phenylt‐butyl sulfide, the hydrocarbon products consisted of 80 ±5% isobutene plus 20% isobutane, while the sulfur containing products were thiophenol and diphenyl disulfide. Order one kinetics was observed for the consumption of the reactants. The first order rate coefficients, based on isobutene production, followed the Arrhenius equations: Benzylt‐butyl sulfide:\documentclass{article}\pagestyle{empty}\begin{document}$$k(s^{ - 1}) = 10^{13.82 \pm 0.41} \exp ( - 214 \pm 6{\rm kJ/mol }RT)$$\end{document}Phenylt‐butyl sulfide:\documentclass{article}\pagestyle{empty}\begin{document}$$k(s^{ - 1}) = 10^{12.03 \pm 0.39} \exp ( - 188 \pm 6{\rm kJ/mol }RT)$$\end{document}Phenylt‐butyl ether:\documentclass{article}\pagestyle{empty}\begin{document}$$k(s^{ - 1}) = 10^{14.30 \pm 0.21} \exp ( - 211 \pm 3{\rm kJ/mol }RT)$$\end{document}For benzylt‐butyl sulfide and phenylt‐butyl ether, the results suggest a unimolecular mechanism involving polar four center cyclic transition states. For phenylt‐butyl sulfide, thet‐butyl‐sulfur single bond fission mechanism is a parallel, less important process t

ISSN:0538-8066    

DOI:10.1002/kin.550210305

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe photo‐oxidation ofn‐heptane in synthetic air containing methyl nitrite and nitric oxide has been ivestigated in an atmospheric flow reactor. By measuring the total yields of heptyl nitrate products, relative to the depletion of then‐heptane, the rate constant ratio,k3b/k3ahas been determined for the reactions:Over the temperature range 253–325 K and at a total pressure of 730 Torr, the following relative Arrhenius equation has been obtained from the present study together with literature data:\documentclass{article}\pagestyle{empty}\begin{document}$$k_{3b} /k_{3a} = (1.4 \pm 1.1) \times 10^{ - 3} \exp [1640 \pm 250)/T]$$\end{document}These results confirm that the formation of alkyl nitrates from the photo‐oxidation ofn‐alkanes arise from a primary reaction between the alkylperoxy radicals and nitric oxide. Furthermore the present experiments show that the lifetime of the intermediate in this type of reaction, presumed to be an alkyl peroxynitrite, ROONO, must be less than a

ISSN:0538-8066    

DOI:10.1002/kin.550210306

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550210301

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY