Kinetics of the Simplest Criegee Intermediate CH 2 OO Reaction with tert -Butylamine.

The kinetics of the simplest Criegee intermediate (CH 2 OO) reaction with tert -butylamine ((CH 3 ) 3 CNH 2 ) was studied under pseudo-first-order conditions with the OH laser-induced fluorescence (LIF) method at the temperature range of 283-318 K and the pressure range of 5-75 Torr. Our pressure-dependent measurement showed that at 5 Torr─the lowest pressure measured in the current experiment─this reaction was under the high-pressure limit condition. At 298 K, the reaction rate coefficient was measured to be (4.95 ± 0.64) × 10 -12 cm 3 molecule -1 s -1 . The title reaction was observed to be negative temperature-dependent; the activation energy of (-2.82 ± 0.37) kcal mol -1 and the pre-exponential factor of (4.21 ± 0.55) × 10 -14 cm 3 molecule -1 s -1 were derived from the Arrhenius equation. The rate coefficient of the title reaction is slightly larger than (4.3 ± 0.5) × 10 -12 cm 3 molecule -1 s -1 of the CH 2 OO reaction with methylamine; the electron inductive effect and the steric hindrance effect might play a role in contributing to such difference.