Laser flash photolysis study of paraquat reduction by photogenerated aromatic ketyl radicals and carbonyl triplets
Results of a kinetic study based on 337.1-nm laser flash photolysis are presented for electron-transfer reactions with paraquat (PQ/sup 2 +/) as the oxidant for the triplets of a number of substituted benzophenones and acetophenones and the corresponding ketyl radicals. The ketyl radicals were generated from the ketone triplets by laser flash photolysis in the presence of excess of p-methoxyphenol. The electron-transfer rate constants (2 x 10/sup 8/-8 x 10/sup 9/ M/sup -1/ s/sup -1/) as well as the fractions (0.5-1.0) of the triplet quenching events that result in net reduction of PQ/sup 2 +/ correlate well with the electron-releasing nature of the substituents in the ketones. Quantitative data concerning the transient absorption spectra of substituted benzophenone triplets and diarylhydroxymenthyl radicals are also reported. 5 figures, 1 table.
- Research Organization:
- Univ. of Notre Dame, Indiana
- OSTI ID:
- 6695899
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 88:7; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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ABSORPTION SPECTRA
AROMATICS
AZINES
BIPYRIDINES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ELECTRON TRANSFER
ETHERS
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
KETONES
KINETICS
LASER RADIATION
MULTIPLETS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PHENOLS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PYRIDINES
RADIATIONS
RADICALS
REACTION KINETICS
REDUCTION
SPECTRA
TRIPLETS