Reactions of Mn(II) and Mn(III) with Alkyl, Peroxyalkyl, and Peroxyacyl Radicals in Water and Acetic Acid

TitleReactions of Mn(II) and Mn(III) with Alkyl, Peroxyalkyl, and Peroxyacyl Radicals in Water and Acetic Acid
Publication TypeJournal Article
Year of Publication2010
AuthorsJee JE, Bakac A
Journal TitleJournal of Physical Chemistry A
Volume114
Pages2136-2141
Date Published02/11
ISBN Number1089-5639
Accession NumberISI:000274270400011
Keywordsacyl radicals, AQUEOUS-SOLUTION, bromide, complexes, decarbonylation, hydrocarbon oxidation, inorganic radicals, kinetics, molecular-oxygen, rate constants
Abstract

The kinetics of oxidation of Mn(II) with acylperoxyl and alkylperoxyl radicals were determined by laser flash photolysis utilizing a macrocyclic nickel complex as a kinetic probe. Radicals were generated photochemically from the appropriate ketones in the presence of molecular oxygen. In both acidic aqueous solutions and in 95% acetic acid, Mn(II) reacts with acylperoxyl radicals with k = (0.5-1.6) x 10(6) M-1 s(-1) and somewhat more slowly with alkylperoxyl radicals, k = (0.5-5) x 10(5) M-1 s(-1). Mn(III) rapidly oxidizes benzyl radicals, k = 2.3 x 10(8) M-1 s(-1) (glacial acetic acid) and 3.7 x 10(8) M-1 s(-1) (95% acetic acid). The value in 3.0 M aqueous perchloric acid is much smaller, 1 x 10(7) M-1 s(-1). The decarbonylation of benzoyl radicals in H2O has k = 1.2 x 10(6) s(-1).

URL<Go to ISI>://000274270400011
DOIDoi 10.1021/Jp910140s