Absolute rate constants for hydrocarbon autoxidation. 32. On the self-reaction of 1,1-diphenylethylperoxyl in solution

• Published in: Canadian journal of chemistry Vol. 60; no. 20; pp. 2566 - 2572
• Main Authors: Howard, J. A, Chenier, J. H. B, Yamada, T
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 15.10.1982
• ISSN: 0008-4042; 1480-3291
• DOI: 10.1139/v82-369

The major products of the self-reaction of 1,1-diphenylethylperoxyl have been determined from product studies of the autoxidation of 1,1-diphenylethane, induced decomposition of 1,1-diphenylethyl hydroperoxide, and decomposition of 2,2,3,3-tetraphenylbutane under an atmosphere of oxygen. Overall self-reaction is a complex free-radical process involving the intermediacy of 1,1-diphenylethoxyl and 1-phenyl-1-phenoxyethoxyl which undergo H-atom abstraction, β-scission and, in the case of the former radical, rearrangement. Hydroperoxide decomposition under an atmosphere of 36 O 2 has shown that 1,1-diphenylethylperoxyl undergoes β-scission faster than α-cumylperoxyl at 303 K in solution. The values of the rate constants for self-reaction of Ph 2 C(Me)O 2 * relative to those for tert-butylperoxyl are, however, not affected by this reaction. Furthermore they are not affected to any appreciable extent by the efficiency with which Ph 2 C(Me)O * , formed in nonterminating self-reactions, escape from the solvent cage. They are influenced principally by the first-order rate of decomposition of Ph 2 C(Me)OOOOC(Me)Ph 2 .