Historical basis of oxidation kinetics

Although autoxidation reactions have been studied for well over a hundred years, clear understanding of the processes had to await development of the concept of free radical chain reactions in the 1920s [1—3]. Credit for first recognizing the radical chain nature of an autoxidation 

A contemporary and widely held theory, occasionally advanced even today, proposed direct addition of ground-state oxygen to carbon—carbon double bonds to form endoperoxides or dioxetanes [3] 

Despite a diligent search for evidence of dioxetane formation, no one has been able to verify the occurrence of this proposed reaction. Moreover, since benzaldehyde could not undergo this type of reaction, an alternate explanation which could also be applied to olefins was desirable. 

That peroxy radicals were important and common radical intermediates in autoxidation became clearer from the work of Criegee et al. [4J. These workers showed that the peroxide resulting from UV-initiated autoxidation of cyclohexene was a hydroperoxide formed by removal of a reactive allylic hydrogen followed by addition of oxygen and chain transfer between cyclohexenyl peroxy radical and cyclohexene, viz. 

Later studies by Farmer and Sutton [5] greatly extended the concept of allylic hydroperoxidation to a variety of cyclic olefins. 

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