Butylperoxy radicals, interaction

Isobutane reacts with O2 by a free radical chain process similar to the one for n-butane except that cage combinations of r-butoxy radicals produced by terminating interactions of f-butylperoxy radicals gives di-t-butylperoxide . r-Butoxy radicals which escape the solvent cage undergo )8-scission to give methyl radicals and acetone ... 

Percent product distribution acetone 24.5 5.1, 2-methyl-2-propanol 18.8 4.0, 2-methyl-2-hydroperoxypropane 36.7 7.5, 2-methyl-propanal 14.0 3.9, 2-methyl-propanol 4.4 1.3, tertiary butylperoxide < 1.7. The peroxy radicals involved are primary 2-methyl-1-propylperoxy, primary methylperoxy and tertiary 2-methyl-2-propylperoxy. The relatively large yield of tertiary butanol is due to the interaction between CH3OO and tertiary butylperoxy radicals. Computer simulations based on the known rate coefficients for the self-reactions of these radicals [2] gave = 3 x 10" cm molecule s for the cross combination reaction. To simulate the observed ratio of primary alcohol and aldehyde requires a rate coefficient p 3 x 10" cm molecule s for the interaction between 2-methyl-1-propylperoxy and tertiary 2-methyl-2-propyl-peroxy radicals. The oxidation mechanism is quantitatively well understood. 

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