Redox reactions of dioxygen complexes of cobalt(III) with organic radicals studied by pulse radiolysis. [9 MeV electrons, gamma rays]
Reduction processes of ..mu..-superoxo complexes of cobalt(III), ((NH/sub 3/)/sub 4/Co(..mu..O/sub 2/, ..mu..NH/sub 2/)Co(NH/sub 3/)/sub 4/)/sup 4 +/, 1, ((en)/sub 2/Co-(..mu..O/sub 2/, ..mu..NH/sub 2/)Co(en)/sub 2/)/sup 4 +/, 2 (en = ethylenediamine), ((CN)/sub 5/Co(..mu..O/sub 2/)Co(CN)/sub 5/)/sup 5 -/, 3, with the formate radical, the alkyl hydroxy radicals CH/sub 2/OH, CH/sub 3/CHOH, (CH/sub 3/)/sub 2/COH, and (CH/sub 3/)COH and the solvated electron were investigated. Reduction of these complexes occurs at the dioxygen center and the products of the reduction are determined to be the corresponding ..mu..-peroxo complexes. The reduction of complexes 2 and 3 by the solvated electron is studied and the biomolecular rate constant for the reduction of 2 is higher by two orders of magnitude than that for the reduction of 3. The same behavior is observed for the reaction of these ..mu..-superoxo complexes with the formate radical, indicating that the effect is due to the presence of the 4+ charge in 1 and 2 and the 5- charge in 3. The isopyropyl radical reacts with the ..mu..-superoxo cobalt(III) complexes faster than CH/sub 2/OH and C/sub 2/H/sub 4/OH radicals. The product observed for the reduction of the ..mu..-superoxo amine complexes by the isopropyl radical appears to be an isomer of the peroxo complex. It is proposed that the reaction of the isopropyl radical with the superoxo complexes proceeds in part by involving the metal center.
- Research Organization:
- Univ. of Notre Dame, IN
- OSTI ID:
- 6934688
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 85:2; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400600* -- Radiation Chemistry
ABSORPTION SPECTRA
ALCOHOLS
ALKALI METAL COMPOUNDS
AMINES
BEAMS
CARBOXYLIC ACID SALTS
CHALCOGENIDES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
COBALT COMPLEXES
COMPARATIVE EVALUATIONS
COMPLEXES
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
ELECTRONS
ELEMENTARY PARTICLES
ENERGY RANGE
ETHANOL
FERMIONS
FORMATES
G VALUE
GAMMA RADIATION
HYDROXY COMPOUNDS
IONIZING RADIATIONS
IRRADIATION
KINETICS
LEPTON BEAMS
LEPTONS
METHANOL
MEV RANGE
MEV RANGE 01-10
NITROGEN COMPOUNDS
NITROGEN OXIDES
NITROUS OXIDE
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PARTICLE BEAMS
PROPANOLS
PULSED IRRADIATION
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOLYSIS
REACTION KINETICS
REDOX REACTIONS
SODIUM COMPOUNDS
SOLVATED ELECTRONS
SPECTRA
TRANSITION ELEMENT COMPLEXES