Thermochemical kinetics of nitrogen compounds. V. The unimolecular thermal decomposition of diallylamine in the gas phase

摘要

AbstractThe kinetics of the thermal decomposition of diallylamine to propylene and prop‐2‐enaldimine have been studied in the gas phase in presence of an excess of methylamine over the temperature range of 532.7 to 615.6°K, using a static reaction system. Methylamine reacted with the unstable primary product prop‐2‐enaldimine, forming the thermally stableN‐methyl prop‐2‐enaldimine.First‐order rate constants, based on the internal standard technique, fit the Arrhenius relationship logk(s−1) = (11.04 ± 0.13) − (37.11 ± 0.33 kcal/mole)/2.303RT.They were independent on the initial total pressure (46–340 torr), the initial pressure of diallylamine (9.2–65 torr), or methylamine as well as the conversion attained. Despite an apparent surface sensitivity, the reaction is essentially homogeneous in nature as demonstrated by experiments carried out in a packed reaction vessel.The observed activation parameters for the title reaction together with those observed earlier for triallylamine and allylcyclohexylamine are consistent with the proposed concerted reaction mechanism involving a cyclic 6‐center transition state. The observed substituent effects suggest a nonsynchronous mode of bond