Photoinduced reactions of 1-(dimethylethyl)-2,2-dimethylpropyl and cyclohexyl radicals in low-temperature solids

Photoinduced reactions of 1-(dimethylethyl)-2,2-dimethylpropyl and cyclohexyl radicals in 77 K solids were studied by the ESR method. 1-(Dimethylethyl)-2,2-dimethylpropyl is converted to 2,2,4,4-tetramethylpentyl radical with photoirradiation of 254 nm light. A hydrogen atom of methyl groups can hence directly transfer to the radical site at a carbon atom other than an adjacent one in the photoinduced reactions of alkyl radicals. Cyclohexyl radical is converted to cyclopentylmethyl radical with irradiation of 254 nm light. The photolysis of cyclohexyl radical causes C–C bond scission, and results in the formation of 5-hexenyl radical. It is then converted to cyclopentylmethyl radical through intramolecular rearrangement.