Kinetics of the thermal gas-phase decomposition of 2,3-epoxy-2-methylbutane

Abstract

The kinetics of the gas-phase decomposition of 2,3-epoxy-2-methylbutane have been studied over the temperature range 665–715 K at pressures between 1.5 and 27 Torr. Isomerizations to 2,2-dimethylpropanal, 3-methylbutan-2-one, ethyl isopropenyl ether, 2-methylbut-3-en-2-ol and 3-methylbut-3-en-2-ol account for ∼95 % of the primary reactions and these isomerizations occur by first-order, homogeneous, non-radical processes. k_{2,2-dimethylpropanal}/s^–1= 10^{13.03 ± 0.26} exp(– 226.2 ± 3.5 kJ mol^–1/RT)k_{3-methylbutan-2-one}/s^–1= 10^{13.05 ± 0.38} exp(– 224.9 ± 5.0 kJ mol^–1/RT)k_{ethyl isopropenyl ether}/s^–1= 10^{13.18 ± 0.29} exp(– 230.6 ± 3.8 kJ mol^–1/RT)k_{2-methylbut-3-en-2-ol}/s^–1= 10^{12.01 ± 0.23} exp(– 228.9 ± 3.1 kJ mol^–1/RT)k_{3-methylbut-3-en-2-ol}/s^–1= 10^{11.94 ± 0.62} exp(– 213.5 ± 8.2 kJ mol^–1/RT)

Comparisons of the results from this study and from studies of gas-phase thermal reactions of other epoxides are made and questions are raised regarding the validity of a biradical reaction mechanism.