Reactions of methyl radicals with 3-methyloxetane, 3,3-dimethyloxetane and 2,2-dimethyloxetane

Abstract

The reactions of methyl radicals with 3-methyloxetane, 3,3-dimethyloxetane and 2,2-dimethyloxetane have been studied. The overall rates of hydrogen-atom abstraction from these three compounds have been obtained over the temperature range 100–200 °C by assuming the value of Quinn and coworkers (J. Chem. Soc., Faraday Trans. 1, 1976, 72, 1935) for the rate of recombination of methyl radicals. The following rate expressions were found: log₁₀(k₄/cm³ mol^–1 s^–1)_(3ox)= 11.69 (± 0.20)–38.23 (± 0.84) kJ mol^–1/2.303RT log₁₀(k₄/cm³ mol^–1 s^–1)_(3,3ox)= 11.72 (± 0.20)–39.47 (± 1.0) kJ mol^–1/2.303 RT log₁₀(k₄/cm³ mol^–1 s^–1)_(2,2ox)= 11.99 (± 0.23)–41.24 (± 1.13) kJ mol^–1/2.303 RT. From these rate expressions and those obtained previously for three other oxetane molecules, the rate parameters for hydrogen-atom abstraction from five distinct sites in the substituted oxetane molecules have been obtained.