Cyclopentane-1,3-diyl radical cation; ESR evidence for its intermediacy in the radiolytic oxidation of bicyclo[2.1.0]pentane to the cyclopentene radical cation in Freon matrices

Abstract

The title radical cation (2) has been detected and characterized by ESR spectroscopy as the initial product of the radiolytic oxidation of bicyclo[2.1.0]pentane (1) in the CF₃CCl₃, CF₂ClCFCl₂, CFCl₂CFCl₂, and CFCl₃ matrices at 77K, its formation being accompanied by retention of C_s symmetry with the development of planar carbon centres at the original bridgehead positions; (2) undergoes subsequent isomerization to the cyclopentene radical cation (3) by intramolecular hydrogen transfer at ca. 100K.