The Addition of Neopentane to Slowly Reacting Mixtures of Hydrogen and Oxygen at 480 DEG C: Formation of Primary Products from Neopentane.

摘要

When small amounts of neopentane are added to slowly reacting mixtures of H2+O2+N2 at 480 C, the major primary products are isobutene, 3,3-dimethyloxetan, CH3COCH3,CH4, and HCHO. In the initial stages of the reaction, the product ratios (CH3COCH3)/(3,3-dimethyloxetan) and ((CH3COCH3)+(3,3-dimethyloxetan))/(isobutene) are almost linearly dependent on the pressure of o2 used. An oxidative mechanism involving the formation of (CH3) 2C (CH2OOH)CH2 and (CH3)2C (CH2OOH)CH2O2 radicals is proposed, and rate constants for a number of the elementary steps have been determined. The rate constant obtained for the reaction(CH3)3CCH2O2 yields (CH3)2C(CH2OOH)CH2 is a factor of about 100 lower than previously suggested. Mechanisms for the formation of the minor primary products, 2-methylprop-2en-l-al, 2-methylprop-2-en-l-ol, and isobutyraldehyde are also discussed. A maximum value of 1/1600 sec is obtained for the rate constant of the methyl-group transfer reaction (CH3)3CCH2O2 (CH3)2CCH2OOch3.