Geminate recombination kinetics has been studied using the diffuse reflectance laser flash technique of radical ion pairs (RIP) formed by electron transfer from triphenylamine to triplet benzophenone, 9,1 O-anthraquinone, duroquinone or 2,6diphenyl-1,4benzoquinone both adsorbed onto porous silica. T
Laser flash photolysis study of ketone—phenol—cyclodextrin inclusion complexes. Geminate recombination kinetics of triplet radical pairs
✍ Scribed by P.P. Levin; Ya.N. Malkin; V.A. Kuzmin
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 481 KB
- Volume
- 175
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
The kinetics of the 4-carboxybenzophenone triplet excited state quenching by 2,4,6&methylphenol and the formation of ketyl and phenoxyl radicals in aqueous P-cyclodextrin solutions have been studied using the laser flash technique. One third of the ketyl and the phenoxyl radicals are formed by a fast process and this formation has been ascribed to a reaction in the cyclodextrin cavity containing both the donor and the acceptor molecules. The rate constant of geminate recombination of triplet radical pairs within the cavity was independent of the external magnetic field up to 0.24 T. The value of this rate constant (I .2X IO's_' ) is close to those for intersystem recombination of contact triplet radical pairs in other organized systems.
📜 SIMILAR VOLUMES
The geminate recombination kinetics of radical pairs formed by hydrogen-atom transfer from 2,4,6-trimethylphenol to the triplet state of benzophenone coadsorbed on microcrystalline cellulose has been studied, using the diffuse-reflectance laser-flash technique. The kinetics is described by the sum o