摘要:

AbstractThe effect of the polarity of seven solvents (ϵ ≈ 2–60) on the rate of ozone reactions with stilbene and allyl chloride has been studied. The data show that the rate of the reaction is insensitive to the medium polarity. The results of earlier publications are revised and are shown to be in agreement with the present

ISSN:0538-8066    

DOI:10.1002/kin.550160103

出版商:John Wiley&Sons, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe gas‐phase decompositions of methylsilane and methylsilane‐d3have been investigated in a single‐pulse shock tube at 4700 torr total pressure in the temperature range of 1125–1250 K. For CH3SiD3at 1200 K three primary steps occur in the homogeneous decomposition with efficiencies in parentheses:\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm CH}_{\rm 3} {\rm SiD}_{\rm 3} \mathop {\longrightarrow} \limits^1 {\rm CH}_{\rm 3} {\rm SiD} + {\rm D}_{\rm 2} \left( {0.71} \right) $$\end{document},\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm CH}_{\rm 3} {\rm SiD}_{\rm 3} \mathop {\longrightarrow} \limits^2 {\rm CH}_{\rm 4} + {\rm SiD}_{\rm 2} \left( {0.15} \right) $$\end{document}, and\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm CH}_{\rm 3} {\rm SiD}_{\rm 3} \mathop {\longrightarrow} \limits^3 {\rm CH}_{\rm 2} \raise1pt\hbox{=\kern-3.45 pt=} {\rm SiD}_{\rm 2} \left( {0.14} \right) $$\end{document}. For CH3SiH3at 1200 K the primary CH4elimination efficiency is 0.09 while the total primary H2elimination efficiency is 0.91. Minor product formations of C2H4, acetylene, dimethylsilane, and SiH4are di

ISSN:0538-8066    

DOI:10.1002/kin.550160104

出版商:John Wiley&Sons, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe static system pyrolysis of methylsilane (T∼ 700 K,PT∼ 150 torr), pure and in the presence of ethylene, propylene, and acetylene, has been investigated. It is proposed that in the uninhibited system, the major products (silane and dimethylsilane) are produced by free radical processes, and that the free radicals are formed at the walls from methylsilylenes. In the presence of olefins, the free radicals are trapped to form methylsilane adducts. In acetylene, trapping of methylsilylenes prevents free radical production and eliminates the free radical produced products of the pure and the olefin inhibited systems. Rates of initiation correlate with rates of reactant loss in acetylene inhibited systems, and with rates of hydrogen formation in olefin inhibited systems. Rough estimates of primary dissociation process yields give for the 1,1‐H2elimination ϕ1,1≅ 0.78, for the 1,2‐H elimination ϕ1,2≅ 0.16, and for the methane elimination ϕCH4≅ 0.06 at 700 K. Deuteration lowers initial step kinet

ISSN:0538-8066    

DOI:10.1002/kin.550160105

出版商:John Wiley&Sons, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe homogeneous gas‐phase decomposition kinetics of methylsilane and methylsilane‐d3have been investigated by the comparative‐rate‐single‐pulse shock‐tube technique at total pressures of 4700 torr in the 1125–1250 K temperature range. Three primary processes occur: CH3SiH3→ CH3SiH + H2(1), CH3SiH3→ CH4+ SiH2(2), and CH3SiH3→ CH2= SiH2+ H2(3). The high‐pressure rate constants for the primary processes in CH3SiH3obtained by RRKM calculations are log (k1+k3) (s−1) = 15.2 ‐ 64,780 Cal/θ and logk2(s−) = 14.50 ‐ 67,600 → 2800 Cal/θ. For CH3SiD3these same rate constants are logk1(s−) = 14.99 ‐ 64,700 cal/θ logk2(s−) = 14.68 – 66,700 → 200

ISSN:0538-8066    

DOI:10.1002/kin.550160106

出版商:John Wiley&Sons, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe absolute rate constants for the reactions of OH + HO2NO2(1) and OH + HNO3(2) have been measured with the technique of flash photolysis resonance fluorescence over the temperature ranges of 240–330 K at 760 torr He for reaction (1) and of 240–370 K at 50 and 760 torr He for reaction (2). Reactant concentrations were monitored continuously by ultraviolet and infrared spectrophotometry. The data can be fitted to the following Arrhenius expressions:\documentclass{article}\pagestyle{empty}\begin{document}$$ k_1 = \left( {5.9 \pm 0.4} \right) \times 10^{ - 13} \exp \left[ {{{\left( {650 \pm 30} \right)} \mathord{\left/ {\vphantom {{\left( {650 \pm 30} \right)} T}} \right. \kern-\nulldelimiterspace} T}} \right]{{{\rm cm}^{\rm 3} } \mathord{\left/ {\vphantom {{{\rm cm}^{\rm 3} } {{\rm molecule} \cdot {\rm s}}}} \right. \kern-\nulldelimiterspace} {{\rm molecule} \cdot {\rm s}}} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm CH}_{\rm 3} {\rm SiD}_{\rm 3} \mathop {\longrightarrow} \limits^3 {\rm CH}_{\rm 2} \raise1pt\hbox{=\kern-3.45 pt=} {\rm SiD}_{\rm 2} \left( {0.14} \right) $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k_2 = \left( {8.3 \pm 0.9} \right) \times 10^{ - 15} \exp \left[ {{{\left( {850 \pm 40} \right)} \mathord{\left/ {\vphantom {{\left( {850 \pm 40} \right)} T}} \right. \kern-\nulldelimiterspace} T}} \right]{{{\rm cm}^{\rm 3} } \mathord{\left/ {\vphantom {{{\rm cm}^{\rm 3} } {{\rm molecule} \cdot {\rm s}}}} \right. \kern-\nulldelimiterspace} {{\rm molecule} \cdot {\rm s}}} $$\end{document}These results are in very good agreement with recent studies of reaction (2), and also of reaction (1) at 29

ISSN:0538-8066    

DOI:10.1002/kin.550160107

出版商:John Wiley&Sons, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe rate coefficients for the gas‐phase pyrolyses of a series of structurally related secondary acetates have been measured in a static system over the temperature range of 289.1–359.5°C and the pressure range 50.0–203.0 torr. The temperature dependence of the rate coefficients is given by the following Arrhenius equations: for 3‐hexyl acetate, logk1(s−) = (12.12 ± 0.33) − (176.1 ± 3.9)kJ/mol/2.203RT; for 5‐methyl‐3‐hexyl acetate, logk1(s−) = (13.17 ± 0.20) − (186.2 ± 2.3)kJ/mol/2.303RT; and for 5,5‐dimethyl‐3‐hexyl acetate, logk1(s−) = (12.70 ± 0.19) − (177.4 ± 2.2)kJ/mol/2.303RT. The direction of elimination of these esters has shown from the invariability of olefin distributions at different temperatures and percentages of decomposition that steric hindrance is a determining factor in the eclipsedcisconformation. Moreover, a more detailed analysis indicates that the greater the alkyl–alkyl interaction, the less favored the elimination tends to be. Otherwise, an increase of alkyl–hydrogen interaction caused steric

ISSN:0538-8066    

DOI:10.1002/kin.550160108

出版商:John Wiley&Sons, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractCross‐disproportionation/combination ratios for CFH2and CF3with C2H5radicals have been determined to be Δ = 0.032 ± 0.012 and δ = 0.098 ± 0.020, respectively, over the temperature range 25–75°C. For the pathway that yields CFH and C2H6, δ = 0.020 ± 0.0

ISSN:0538-8066    

DOI:10.1002/kin.550160109

出版商:John Wiley&Sons, Inc.    

年代:1984

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550160102

出版商:John Wiley&Sons, Inc.    

年代:1984

数据来源: WILEY