Methyl Affinities Determined by Photolysis of Azomethane

The thermal decomposition of acetyl peroxide forms acetate radicals which decarboxylate into methyl radicals. The reaction products may result, therefore, either from methyl radicals or from acetate radicals which decarboxylate simultaneously as they interact with the substrate. To identify the reacting species, reactions previously investigated in an acetyl peroxide system were reinvestigated using the photolysis of azomethane as the source of radicals. The results prove that at least in hydrocarbon solvents methyl radicals, and not acetate radicals, are the reacting species in the acetyl peroxide system. Furthermore, it was shown that photolysis of azomethane in solution provides us with a clean and simple system to study reactions of methyl radicals.