title: Reactions of Mn(II) and Mn(III) with alkyl, peroxyalkyl, and peroxyacyl radicals in water and acetic acid.
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 H(2)O has k = 1.2 x 10(6) s(-1).
authors.affiliation: Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Joo-Eun
authors.initials: JE
authors.lastname: Jee
authors.forename: Andreja
authors.initials: A
authors.lastname: Bakac
mesh_terms: D000085:Acetates / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D007659:Ketones / Q000737:chemistry; D007700:Kinetics; D008345:Manganese / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010777:Photochemistry; D014867:Water / Q000737:chemistry*
chemical_list: D000085:Acetates; D005609:Free Radicals; D007659:Ketones; D014867:Water; D008345:Manganese; D010100:Oxygen