Absolute rate constants for hydrocarbon autoxidation. 28. A low temperature kinetic electron spin resonance study of the self-reactions of isopropylperoxy and related secondary alkylperoxy radicals in solution

Abstract

Isopropylperoxy radicals at low temperatures exist in equilibrium with di-isopropyl tetroxide. The thermodynamic parameters for this equilibrium are very similar to the values of ΔH⁰ and ΔS⁰ for the tert-butylperoxy radical – di-tert-butyl tetroxide equilibrium. Differences in second-order rate constants for mutual destruction of secondary and tertiary alkylperoxy radical appear to result from differences in rate constants for unimolecular decomposition of secondary and tertiary alkyl tetroxides.Isopropylperoxy radicals have the same termination rate constant in the gas phase and in solution.