ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The pyrolyses of p-nitrophenyl t-butyl ether, p-methoxyphenyl t-butyl ether, p-aminophenyl t-butyl ether, p-nitrophenyl t-butyl sulfide, and propargyl t-butyl sulfide have been studied in a stirred-flow reactor over the temperature range 430-530°C and pressures in the range 7-14 torr, using toluene as carrier gas. The reactions yielded between 90 and 99% isobutene plus the corresponding phenol, thiophenol, or thiol as products. The first order rate coefficients for reactant consumption, based on isobutene production, followed the Arrhenius equationsp-nitrophenyl t-butyl ether\documentclass{article}\pagestyle{empty}\begin{document}$$ k({\rm s}^{ - 1}) = 10^{12.79 \pm 0.24} {\rm exp}(- 179 \pm 3{\rm kJ/mol}RT) $$\end{document} p-methoxyphenyl t-butyl ether \documentclass{article}\pagestyle{empty}\begin{document}$$ k({\rm s}^{ - 1}) = 10^{14.50 \pm 0.30} {\rm exp}(- 210 \pm 4{\rm kJ/mol}RT) $$\end{document} p-aminophenyl t-butyl ether: \documentclass{article}\pagestyle{empty}\begin{document}$$ k({\rm s}^{ - 1}) = 10^{14.59 \pm 0.28} {\rm exp}(- 208 \pm 4{\rm kJ/mol}RT) $$\end{document} p-nitrophenyl t-butyl sulfide \documentclass{article}\pagestyle{empty}\begin{document}$$ k({\rm s}^{ - 1}) = 10^{12.12 \pm 0.27} {\rm exp}(- 185 \pm 4{\rm kJ/mol}RT) $$\end{document} propargyl t--butyl sulfide: \documentclass{article}\pagestyle{empty}\begin{document}$$ k({\rm s}^{ - 1}) = 10^{13.79 \pm 0.24} {\rm exp}(- 204 \pm 3{\rm kJ/mol}RT) $$\end{document}The results support a unimolecular elimination of the isobutene involving polar, four-center cyclic transition states.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550221103
Permalink
