Thermal decomposition of cyclopentane and related compounds

Cyclopentane has been decomposed in comparative‐rate single‐pulse shock‐tube experiments. The pyrolytic mechanism involves isomerization to 1‐pentene and also a minor pathway leading to cyclopropane and ethylene. This is followed by the decomposition of 1‐pentene and cyclopropane. The rate expressions over the temperature range of 1000°–1200° K are\documentclass{article}\pagestyle{empty}\begin{document}$$ k(c-{\rm C}_{\rm 5} {\rm H}_{{\rm 10}} \to 1-{\rm C}_{\rm 5} {\rm H}_{{\rm 10}}) = 10^{16.1} \exp (- 42,700/T)\sec ^{- 1} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k(c-{\rm C}_{\rm 5} {\rm H}_{\rm 10} \to (c-{\rm C}_{\rm 3} {\rm H}_{\rm 6} + {\rm C}_{\rm 2} {\rm H}_{\rm 4}) = 10^{16.25} \exp (- 47,840/T)\sec ^{- 1} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k(1 - {\rm pentene} \to {\rm C}_{\rm 3} {\rm H}_{\rm 6} + {\rm C}_{\rm 2} {\rm H}_{\rm 5}) \sim 10^{16} \exp (- 35,900/T)\sec ^{- 1} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k(1 - {\rm pentene} \to {\rm C}_{\rm 3} {\rm H}_{\rm 6} + {\rm C}_{\rm 2} {\rm H}_{\rm 4}) \sim 10^{12.5} \exp (- 28,900/T)\sec ^{- 1} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k(c-{\rm C}_{\rm 3} {\rm H}_{\rm 6} \to {\rm C}_{\rm 3} {\rm H}_{\rm 6}) = 10^{14.3} \exp (- 31,100/T)\sec ^{- 1} {\rm at}\ {\rm 5}\ {\rm atm} $$\end{document}\documentclass{article}\pagestyle{empty}\begin{document}$$ k(c-{\rm C}_{\rm 3} {\rm H}_{\rm 6} \to {\rm C}_{\rm 3} {\rm H}_{\rm 6}) = 10^{14.1} \exp (- 31,100/T)\sec ^{- 1} {\rm at}\ {\rm 1.7}\ {\rm atm} $$\end{document}Details of the cyclopentane decomposition processes are considered, and it appears that if the trimethylene radical is an intermediate, then Δ H f (trimethylene) ≤ 280 kJ/mol at 300°K.