Oxidation of substituted alkyl radicals by IrCl/sub 6//sup 2 -/, Fe(CN)/sub 6//sup 3 -/, and MnO/sub 4//sup -/ in aqueous solution. Electron transfer versus chlorine transfer from IrCl/sub 6//sup 2 -/
- Institut fuer Strahlenchemie in Max-Planck-Institut Fuer Kohlenforschung, Muelheim, Germany
Alkyl radicals substituted at C/sub ..cap alpha../ by alkyl, carboxyl, hydroxyl, alkoxyl, and chlorine react in aqueous solutions with Ir/sup IV/Cl/sub 6//sup 2 -/ to yield Ir(III) species. In the case of substitution by hydroxyl and alkoxyl, the rate constants are in the diffusion-controlled range ((4-6) x 10/sup 9/ M/sup -1/s/sup -1/) and the reaction proceeds by electron transfer. In the case of ethyl, methyl, carboxymethyl, and chloromethyl radicals the rate constants range from 3.1 x 10/sup 9/ for ethyl to 2.8 x 10/sup 7/M/sup -1/s/sup -1/ for trichloromethyl and the reaction proceeds by chlorine transfer from IrCl/sub 6//sup 2 -/ to the alkyl radical. With isopropyl and tert-butyll radicals the reaction proceeds by both electron and chlorine transfer. Alkyl radicals also react with Fe(CN)/sub 6//sup 3 -/. The rate constants increase strongly with increasing alkylation at C/sub ..cap alpha../ from 5 x 10/sup 6/ for methyl to 3.6 x 10/sup 9/M/sup -1/s/sup -1/ for tert-butyl, indicating that the transition state for the reaction is highly polar. Rate constants for reaction of MnO/sub 4//sup -/ with alkyl radicals are of the order 10/sup 9/M/sup -1/s/sup -1/. 4 figures, 1 table.
- OSTI ID:
- 5582937
- Journal Information:
- J. Am. Chem. Soc.; (United States), Vol. 104:5
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALKYL RADICALS
CHEMICAL REACTION KINETICS
ELECTRON TRANSFER
OXIDATION
WATER
RADIOLYSIS
ALKYLATION
AQUEOUS SOLUTIONS
CHLORINE
CYANATES
ELECTRON EXCHANGE
FERRICYANIDES
IRIDIUM CHLORIDES
MANGANATES
PULSED IRRADIATION
CARBONIC ACID DERIVATIVES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
COMPLEXES
DECOMPOSITION
DISPERSIONS
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HALOGENS
HYDROGEN COMPOUNDS
IRIDIUM COMPOUNDS
IRON COMPLEXES
IRRADIATION
KINETICS
MANGANESE COMPOUNDS
MIXTURES
NITROGEN COMPOUNDS
NONMETALS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
REACTION KINETICS
SOLUTIONS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS
400600* - Radiation Chemistry