ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The pyrolysis of 2,2-dichloro-1,1,1-trifluoroethane was studied over the temperature range of 1120-1260°K at total reflected shock pressures from ∼2800 to 3100 torr. Below 1260°K, the decomposition leads to three reaction products which were identified as CF2CFCl, CF2CFH, and CF3CCl3. The results are interpreted in terms of a parallel C—Cl bond rupture process which becomes competitive with the molecular HCI elimination. The rate constant for the α,α-elimination process \documentclass{article}\pagestyle{empty}\begin{document}$$ CF_3 CHCl_2 \to CF_2 CFCl + HCL $$\end{document} has been deduced to be \documentclass{article}\pagestyle{empty}\begin{document}$$ \log \left( {K_1 ^\infty /\sec ^{ - 1} } \right) = \left( {13.4 \pm 0.7} \right) - \left( {63.1 \pm 3.8kcal} \right)/2.303RT $$\end{document} It was also possible to obtain the overall rate constant for the formation of CF2CFH, which is given by \documentclass{article}\pagestyle{empty}\begin{document}$$ \log \left( {K^{''} /\sec ^{ - 1} } \right) = \left( {11.5 \pm 0.8} \right) - \left( {54.1 \pm 3.8kcal} \right)/2.303RT $$\end{document} Some evidence for hydrogen fluoride elimination was found at temperatures above 1260°K. However, at these higher temperatures C—C bond scission also occurs and the kinetics of the system become untractable.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550050307
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