摘要:

AbstractThe photolyses of ketene (at 313 and 280 nm) and diazirine at 313 nm in the presence ofcis‐butene‐2 were studied. Vibrational relaxation of chemically activated dimethylcyclopropane was shown to occur as a multistep process, and 17 ± 4 kJ mol−1was obtained for the average energy transferred per collision with butene‐2 collider. Activatedcis‐dimethylcyclopropane is formed in the reaction of singlet methylene andcis‐butene‐2 with broad energy distribution which originates from the energy partitioning in the photolytic act. About 30% of the energy released in the photolysis of the methylene source is carried by singlet methylene as vibrational energy at the time of reaction, and this fraction was found to be practically independent of the

ISSN:0538-8066    

DOI:10.1002/kin.550170202

出版商:John Wiley&Sons, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe kinetic deuterium isotope effect in the thermal dehydration stages of powdered SrCl2· 2H2O was examined by means of both isothermal and dynamic gravimetries. These dehydration processes proved to be controlled by a random nucleation and its subsequent growth mechanism. No significant kinetic isotope effect was seen in these dehydration stages. It seems that there exists a kinetic compensation effect between the hydrate and its deuterium analog, if any isotopic differences in activation energy and frequency factor could exist

ISSN:0538-8066    

DOI:10.1002/kin.550170203

出版商:John Wiley&Sons, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe thermal dehydrochlorination CF2ClCH3→ CF2 CH2+ HCl has been studied in a static system between 637 and 758 K. It is a homogeneous, molecular first‐order reaction and its rate constant is given by\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} {\rm }(k,{\rm s}^{ - {\rm 1}}) = - (53,400 \pm 100)/4.576{\rm T + (12}{\rm .21} \pm {\rm 0}{\rm .03)} $$\end{document}This reaction has also been studied in the presence of CCl4and mixtures of CCl4and HCl between 585 and 662 K. It is then accelerated and the initial rate increase is given by\documentclass{article}\pagestyle{empty}\begin{document}$$ v = d[{\rm CF}_{\rm 2} {\rm = CH}_{\rm 2} ]/dt = k' \left( {1 + k'' {\textstyle{{{\rm [HCl]}} \over {{\rm [CF}_{\rm 2} {\rm ClCH}_{\rm 3} {\rm ]}}}}} \right)^{{\raise0.5ex\hbox{$\scriptstyle 1$}\kern-0.1em/\kern-0.15em\lower0.25ex\hbox{$\scriptstyle 2$}}} [{\rm CF}_2 {\rm ClCH}_3 ]^{{\raise0.5ex\hbox{$\scriptstyle 3$}\kern-0.1em/\kern-0.15em\lower0.25ex\hbox{$\scriptstyle 2$}}} $$\end{document}with log10(k′,L½/mol½· s) = −(41,650 ± 180)/4.576T+ (10.84 ± 0.06) and log10k″ = (7900 ± 180)/4.576T− (0.59 ± 0.06). A radical chain mechanism is shown to be consistent with

ISSN:0538-8066    

DOI:10.1002/kin.550170204

出版商:John Wiley&Sons, Inc.    

年代:1985

数据来源: WILEY

摘要:

Abstracts‐Butoxy radicals have been generated by reacting fluorine withs‐butanol:\documentclass{article}\pagestyle{empty}\begin{document}$$ \mathop {\rm F}\limits^{\rm .} + {\rm CH}_3 {\rm CH}_2 {\rm CH}({\rm OH}){\rm CH}_3 \to {\rm HF} + {\rm CH}_3 {\rm CH}_2 {\rm CH}(\mathop {\rm O}\limits^{\rm .}){\rm CH}_3 $$\end{document}Over the temperature range 398.6 to 493.3 K thes‐butoxy radical decomposes by two different pathways to yield acetaldehyde and propionaldehyde, acetaldehyde being the major product:The ratiok1/k2was found to be temperature dependent. An Arrhenius plot of the data (398.6 to 493.3 K) yields the relative Arrhenius parameters,E1‐E2= −11.2 ± 0.8 kJ mol−1and (A1/A2) = 0.59 ± 0.14. The ratio of rate constantsk1/k2was shown to be independent of total pressure (80–600 torr) and of the pressure ofs‐butanol (2–13 torr). The kinetic results for theses‐butoxy decomposition reactions are discussed in relation to the literature data and in terms of the thermochemi

ISSN:0538-8066    

DOI:10.1002/kin.550170205

出版商:John Wiley&Sons, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractAn experimental investigation of the gas‐phase photooxidation of toluene–NOx–air mixtures at part‐per‐million concentrations has been carried out in a 65‐m3, outdoor smog chamber to assess our understanding of the atmospheric chemistry of toluene. In addition, six CONOx–air irradiations were conducted to characterize the chamber with regard to any wall radical sources. Measured parameters in the toluene–NOxexperiments included O3, NO, NO2, HNO3, peroxyacetyl nitrate (PAN), CO, toluene, benzaldehyde,o‐cresol,m‐nitrotoluene, peroxybenzoyl nitrate (PBZN), temperature, relative humidity, aerosol size distributions, and particulate organic carbon. Predictions of the reaction mechanism of Leone and Seinfeld [7] are found to be in good agreement with the data under a variety of initial conditions. Additional simulations are used to investigate various mechanistic pathways in areas where our understanding of toluene chemistr

ISSN:0538-8066    

DOI:10.1002/kin.550170206

出版商:John Wiley&Sons, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe gas phase pyrolysis of 1,1,1,2‐tetrachloropropane was studied in a static system and seasoned vessel over the temperature range of 393.0–452.8°C and pressure range of 27.5–118.5 torr. The reaction is homogeneous, unimolecular, follows a first‐order rate law, and is not affected by the presence of the free radical inhibitor, toluene, or propene. The main dehydrochlorination products are 1,1,1‐trichloro‐2‐propene and 1,1,2‐trichloro‐1‐propene. The temperature dependence of the rate coefficient is given by the Arrhenius equation\documentclass{article}\pagestyle{empty}\begin{document}$$ \log {\rm }k_1 ({\rm s}^{{\rm - 1}}) = (11.98 \pm 0.34) - (205.1 \pm 4.6){\rm kJ/mol/2}{\rm .303}RT $$\end{document}The Arrhenius parameters of this reaction are apparently low. Consequently, in estimating the transition state ofA= 1013.5, the following expression is obtained\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log }k_1 ({\rm s}^{ - {\rm 1}}) = 13.5 - 225.1{\rm kJ/mol/2}{\rm .303}RT $$\end{document}The partial rates and kinetic parameters for the parallel elimination products have been estimated and reported. The trichloromethyl substituent has been found to affect this elimination process through its electro

ISSN:0538-8066    

DOI:10.1002/kin.550170207

出版商:John Wiley&Sons, Inc.    

年代:1985

数据来源: WILEY

摘要:

AbstractThe high temperature pyrolysi of 1,3‐butadiene has been investigated in the shock tube with two time‐resolved diagnostic techniques: laser schlieren measurements of density gradient with 1, 2, 4, and 5% C4H6in Ar or Kr, 0.26

ISSN:0538-8066    

DOI:10.1002/kin.550170208

出版商:John Wiley&Sons, Inc.    

年代:1985

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550170209

出版商:John Wiley&Sons, Inc.    

年代:1985

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550170210

出版商:John Wiley&Sons, Inc.    

年代:1985

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550170201

出版商:John Wiley&Sons, Inc.    

年代:1985

数据来源: WILEY