The ultraviolet absorption spectrum of the neopentyl peroxy radical (CH3)3CCH2O2, and the kinetics and products of its self reaction have been studied in the gas phase at 298 K. Absorption cross sections were quantified over the wavelength range 230-290 nm. Our measured spectrum is in good agreement with previous work. The rate constant for the self reaction is k4 = (1.07 ± 0.22) × 10-12 cm3 molecule-1 s-1. The branching ratio k4a/k4 was measured to be 0.39 ± 0.03. In the presence of 150 torr of O2, neopentoxy radicals produced from reaction (4a) decompose to give HCHO and t-butyl radicals. These findings show that the correct mechanistic interpretation of the distinctly nonsecond order decay of UV absorption in kinetic studies of the self reaction of neopentyl peroxy radicals is that proposed by P. D. Lightfoot et al. Namely, the observed slowly decaying residual absorption is caused by the formation of t-butyl peroxy radicals from the decomposition of neopentoxy radicals.
|Number of pages||15|
|Journal||International Journal of Chemical Kinetics|
|Publication status||Published - Jul 1992|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry