ESR studies on cation-radicals of simple olefins and dienes produced in. gamma. -irradiated frozen solutions of trichlorofluoromethane
Cation radicals of butene-1, trans and cis butene-2, isobutene, tetramethylethylene, cyclopentene, cyclohexene, butadiene, 1,3-pentadiene, cyclopentadiene, 1,3- and 1,4-cyclohexadienes have been produced mostly for the first time in ..gamma..-irradiated frozen matrix of trichlorofluoromethane at 77 K. Well resolved ESR spectra at 77 K or at 130--155 K permit the determination of proton hyperfine coupling constants. Large hyperfine coupling constants of methylene and methyl protons adjacent to ..pi.. electron systems indicate an extensive hyperconjugation in the cations. The following photoisomerizations are found: butene-1/sup +/..-->..butene-2/sup +/, cyclopentene/sup +/..-->..1,3-pentadiene/sup +/, 1,4-cyclohexadiene/sup +/..-->.. 1,3-cyclohexadiene/sup +/, 1,3-cyclohexadiene/sup +/..-->..1,3,5-hexatriene/sup +/. The nonplanar cations of cyclopentene and 1,3-cyclohexadiene undergo puckering motion in a limitedly warmed matrix. In the warmed matrix, where diffusions of the cation radicals toward unreacted hydrocarbon molecules proceed slowly, proton transfer reactions are induced. Decisive evidence for the formation of dimer cations is not obtained under the conditions studied.
- Research Organization:
- Department of Chemistry, Faculty of Science, Kyoto University, Kyoto, Japan
- OSTI ID:
- 7011849
- Journal Information:
- J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 73:12; ISSN JCPSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400600* -- Radiation Chemistry
ALKENES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
DIENES
ELECTROMAGNETIC RADIATION
ELECTRON SPIN RESONANCE
GAMMA RADIATION
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROCARBONS
IONIZING RADIATIONS
MAGNETIC RESONANCE
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
POLYENES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOLYSIS
RESONANCE