摘要:

AbstractCyclopropyl cyanide isomerizes in the gas phase at 660°–760°K and 2–89 torr to give mainlycis‐ andtrans‐crotonitrile and allyl cyanide, with traces of methacrylonitrile. The reactions are first order, homogeneous, and unaffected by the presence of radical‐chain inhibitors. The rate constants are given by Overall:\documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k/{\rm sec}^{ - 1} = (14.58 \pm 0.08) - (242.0 \pm 1.2){\rm kJ}\,{\rm mole}^{ - 1} /2.303RT$$\end{document}cis‐Crotonitrile:\documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k/{\rm sec}^{ - 1} = (14.01 \pm 0.11) - (237.6 \pm 1.4){\rm kJ}\,{\rm mole}^{ - 1} /2.303RT$$\end{document}trans‐Crotonitrile:\documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k/{\rm sec}^{ - 1} = (14.09 \pm 0.07) - (243.7 \pm 0.9){\rm kJ}\,{\rm mole}^{ - 1} /2.303RT$$\end{document}Allyl cyanide:\documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k/{\rm sec}^{ - 1} = (14.59 \pm 0.13) - (252.0 \pm 1.8){\rm kJ}\,{\rm mole}^{ - 1} /2.303RT$$\end{document}where the error limits are standard deviations. On the basis of a biradical mechanism, it is deduced that the CHCN radical center is resonance stabilized by ca. 30 kJ mole−1. Approximate equilibrium data are given for interconversion of the 1

ISSN:0538-8066    

DOI:10.1002/kin.550050112

出版商:John Wiley&Sons, Inc.    

年代:1973

数据来源: WILEY

摘要:

AbstractAbsolute rate constants for the reaction of S(3P) with ethylene episulfide were measured over a C2H4S concentration range of 5, a total pressure of 20–200 tort, and a flash intensity range of ˜4. Over this range of variables, the bimolecular rate constant was found to be invariant. Because of limitations imposed by the physical properties of the reactant C2H4S, temperature variations were necessarily held to the range 298–355°K. The bimolecular rate constant was found to be invariant over this limited temperature range, having a value of (4.47 ± 0.26) × 10−11cm3molec.−1sec−1. The possible influence of this reaction in studies of the S(3P)–ethylene syste

ISSN:0538-8066    

DOI:10.1002/kin.550050113

出版商:John Wiley&Sons, Inc.    

年代:1973

数据来源: WILEY

摘要:

AbstractThe I2‐catalyzed isomerization of allyl chloride tocis‐ andtrans‐ l‐chloro‐l‐propene was measured in a static system in the temperature range 225–329°C. Propylene was found as a side product, mainly at the lower temperatures. The rate constant for an abstraction of a hydrogen atom from allyl chloride by an iodine atom was found to obey the equation log [k,/M−1sec−1] = (10.5 ± 0.2) −; (18.3 ± 10.4)/θ, where θ is 2.303RTin kcal/mole. Using this activation energy together with 1 ± 1 kcal/mole for the activation energy for the reaction of HI with alkyl radicals givesDH0(CH2CHCHClH) = 88.6 ± 1.1 kcal/mole, and 7.4 ± 1.5 kcal/mole as the stabilization energy (SE) of the chloroallyl radical. Using the results of Abell and Adolf on allyl fluoride and allyl bromide, we concludeDH0(CH2CHCHFH) = 88.6 ± 1.1 andDH0(CH2CHCHBrH) = 89.4 ± 1.1 kcal/ mole; the SE of the corresponding radicals are 7.4 ± 2.2 and 7.8 ± 1.5 kcal/mole. The bond dissociation energies of the CH bonds in the allyl halides are similar to that of propene, while the SE values are about 2 kcal/mole less than in the allyl radical, resulting perhaps more from the stabilization of alkyl radicals by α‐halogen atoms than f

ISSN:0538-8066    

DOI:10.1002/kin.550050114

出版商:John Wiley&Sons, Inc.    

年代:1973

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550050115

出版商:John Wiley&Sons, Inc.    

年代:1973

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550050116

出版商:John Wiley&Sons, Inc.    

年代:1973

数据来源: WILEY

ISSN:0538-8066    

DOI:10.1002/kin.550050101

出版商:John Wiley&Sons, Inc.    

年代:1973

数据来源: WILEY