Gas phase thermolysis of allyl cyanomethyl amine, diallyl cyanomethyl amine, diethyl cyanomethyl amine, and diethyl propargyl amine

The title amines were pyrolyzed in a stirred‐flow reactor at 380–510°C, pressures of 8–15 torr and residence times of 0.3–2.4 s, using toluene as carrier gas. The substrates with an allyl group yielded propene and iminonitriles as reaction products. HCN is formed by decomposition of the iminonitriles. The first‐order rate coefficients for propene formation fit the Arrhenius equations Allyl cyanomethyl amine:\documentclass{article} \pagestyle{empty} \begin{document} $$ k({\rm s}^{ - {\rm 1}}) = 10^{13.29 \pm 0.35} {\rm exp(} - {\rm 189} \pm 5{\rm kJ/mol }RT{\rm)} $$ \end{document}Diallyl cyanomethyl amine:\documentclass{article} \pagestyle{empty} \begin{document} $$ k({\rm s}^{ - {\rm 1}}) = 10^{13.00 \pm 0.20} {\rm exp(} - {\rm 183} \pm 3{\rm kJ/mol }RT{\rm)} $$ \end{document}Diethyl cyanomethyl amine gave a 20:1 gas mixture of ehylene and ethane, plus HCN. The liquid product fraction contained mainly N ‐ethyl methanaldimine. The first‐order rate coefficients for ethylene formation followed the Arrhenius equation\documentclass{article}\pagestyle{empty}\begin{document}$$ k({\rm s}^{ - {\rm 1}}) = 10^{15.30 \pm 0.24} {\rm exp(} - {\rm 226} \pm 3{\rm kJ/mol }RT{\rm)} $$\end{document}Diethyl propargyl amine decomposed cleanly into allene and N ‐ethyl ethanaldimine. The first‐order rate coefficients for allene formation fit the Arrhenius equation\documentclass{article}\pagestyle{empty}\begin{document}$$ k({\rm s}^{ - {\rm 1}}) = 10^{12.84 \pm 0.30} {\rm exp(} - {\rm 168} \pm 4{\rm kJ/mol }RT{\rm)} $$\end{document}The results suggest that the above allyl and propargyl amines decompose unimolecularly by mechanisms involving six‐center cyclic transition states. For diethyl cyanomethyl amine, a nonchain free radical mechanism is proposed. © 1995 John Wiley & Sons, Inc.