Reactions of isopropoxyl radicals

Abstract

The thermal decomposition of di-isopropyl peroxide has been studied over the temperature range 121–159°C in the presence of nitricoxide. Kinetic data for the initial fission of the O—O bond have been established and used to estimate the enthalpy of formation of the isopropoxyl radical. iso-Propoxyl radicals react readily with nitric oxide by cross-combination to form the nitrite or by cross-disproportionation to form acetone and nitroxyl. The ratio of the rate constants is independent of the temperature. The abstraction of hydrogen atoms from the peroxide by methyl radicals (generated by the selective photolysis of azomethane) has been studied over the temperature range 47–93°C.

Arrhenius parameters have been determined for the following reactions: [graphic omitted] A value of –11.3 kcal mole ^–1 has been deduced for the heat of formation of the isopropoxyl radical.