Gas Phase Thermolysis of Allyl Cyanomethyl Amine, Diallyl Cyanomethyl Amine, Diethyl Cyanomethyl Amine, and Diethyl Propargyl Amine

Article abstract of DOI:10.1002/kin.550270203

The title amines were pyrolyzed in a stirred-flow reactor at 380 - 510 deg 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: k(s^-1) = 10^{13.29 +/- 0.35}exp(-189 +/- 5 kJ/mol RT) Diallyl cyanomethyl amine: k(s^-1) = 10^{13.00 +/- 0.20}exp(-183 +/- 3 kJ/mol RT) Diethyl cyanomethyl amine gave a 20:1 gas mixture of ethylene 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 k(s^-1) = 10^{15.30 +/- 0.24}exp(-226 +/- 3 kJ/mol RT) Diethyl propargyl amine decomposed cleanly into allene and N-ethyl ethanaldimine.The first-order rate coefficients for allene formation fit the Arrhenius equation k(s^-1) = 10^{12.84 +/- 0.30}exp(-168 +/- 4 kJ/mol RT).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.