Hexadienes radiolysis

For example, EPR evidence showed that cyclohexane-1,4-diyl, generated by radiolysis of hexadiene, rearranged to cyclohexene radical cation. Similarly, ant/-5-methylbicyclo[2.1.0]-pentane radical cation (33) rearranged to 1-methylcy-clopentene radical cation (34) via a 1,2-shift of the syn-5-hydrogen. ... 

Pan X-M, Bastian E, von Sonntag C (1988) The reactions of hydroxyl radicals with 1,4- and 1,3-cydo-hexadiene in aqueous solution. A pulse radiolysis and product study. Z Naturforsch 43b 1201-... 

Liquid hexafluorobenzene, upon radiolysis with Co y-radiation - produces hexafluorobicyclo[2.2.0]hexa-2,5-diene. In the gas phase, perfluorocyclo-hexadiene is produced as well. 

Figure 2 also gives the G-values of the various products in the radiolysis of mixtures of cyclopropane-propene. The maximum in the acetylene yield is at a cyclopropane molar fraction of 0.75 and in the ethylene yield at cyclopropane molar fraction of 0.25 indicating probably that they are produced in competing reactions of the same intermediate. The curve of the yields of isobutane, 4-methyl-1-pentene and 1,5-hexadiene indicate bimolecular reactions since none of them is formed in the pure components. Foldiak and Horvath" suggested that the formation of these hydrocarbons may be explained by combination reactions between the reactive intermediates existing in high steady state concentrations in the system, as in equations 48 and 49 ... 

Many studies used radiation chemistry to produce the radical and radical cations and anions of various dienes in order to measure their properties. Extensive work was devoted to the radical cation of norbomadiene in order to solve the question whether it is identical with the cation radical of quadricyclane . Desrosiers and Trifunac produced radical cations of 1,4-cyclohexadiene by pulse radiolysis in several solvents and measured by time-resolved fluorescence-detected magnetic resonance the ESR spectra of the cation radical. The cation radical of 1,4-cyclohexadiene was produced by charge transfer from saturated hydrocarbon cations formed by radiolysis of the solvent. In a similar system, the radical cations of 1,3- and 1,4-cyclohexadiene were studied in a zeolite matrix and their isomerization reactions were studied. Dienyl radicals similar to many other kinds of radicals were formed by radiolysis inside an admantane matrix. Korth and coworkers used this method to create cyclooctatrienyl radicals by radiolysis of bicyclo[5.1.0]octa-2,5-diene in admantane-Di6 matrix, or of bromocyclooctatriene in the same matrix. Williams and coworkers irradiated 1,5-hexadiene in CFCI3 matrix to obtain the radical cation which was found to undergo cyclization to the cyclohexene radical cation through the intermediate cyclohexane-1,4-diyl radical cation. 

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