Autoxidation RUSSELL mechanism

A detailed mechanism is proposed for this recombination process. On the basis of the experimental results obtained, Beutel (for details see 13>) comes to the conclusion that in the case of dimedone autoxidation the triplet triketone D = O cannot be efficiently quenched by ground-state triplet oxygen formed in the decomposition of a Russell tetroxide which in this case should have the formula. 

Russell GA (1957) Deuterium-isotope effects in the autoxidation of aralkyl hydrocarbons. Mechanism of the interaction of peroxy radicals. J Am Chem Soc 79 3871-3877... 

Termination of the autoxidation chain process occurs as peroxyl radicals couple to yield non-radical products. This reaction takes place through an unstable tetroxide intermediate. Primary and secondary tetroxides decompose rapidly by the Russell termination mechanism to yield three non-radical products via a six-membered cyclic transition state (Fig. 95). The decomposition yields the corresponding alcohol, carbonyl compound, and molecular oxygen (often in the higher energy singlet oxygen state) three... 

Russell, G. A. Deuterium-isotope Effects in the Autoxidation of Aralkyl Hydrocarbons. Mechanisms of the Interaction of Peroxy Radicals. /. Am. Chem. Soc. 79 3871, 1957. 

Russell, G.A. Pathways in autoxidation, in Peroxide Reaction Mechanisms, pp. 107-128 (1962) (edited by J. O. Edwards), Interscience Publ., New York. 

The autoxidations of certain carbanions, such as fluorenide anion, have been demonstrated to proceed via a chain mechanism involving electron transfer (Russell, 1953 Russell et al., 1965, 1968) as shown in Scheme 8. In MejSO... 

Russell (10) suggested that the bimolecular self-reaction of S-RO2 involves the concerted decomposition of a cyclic tetroxide formed by combination of the radicals. This mechanism was deduced from a consideration of the results of a kinetic and product study of the autoxidation of ethylbenzene. Thus Russell found that almost one molecule of acetophenone is produced per two kinetic chains and that CeHsCHCCHa)O2 interact to form non-radical products nearly twice as fast as CsHsCDCcHs) O2. The former result is only compatible with (29) if all the alkoxy radicals disproportionate in the solvent cage (30) while the deuterium isotope effect requires a H-atom transfer reaction to be rate controlling, which is unlikely for the radical pathway. 

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