Analysis of the ESR spectra of the ∼CF2CFCF2∼ macroradical trapped in a γ-irradiated polytetrafluoroethylene matrix at 77 K

The p-fluorine atoms in the similar to CF(2)dFCF(2)similar to radical trapped in gamma-irradiated polytetrafluoroethylene (PTFE) were found to be nonequivalent and, hence, responsible for a doublet-triplet-triplet ESR spectral pattern. The conformational angle between the axis of the unpaired-electron orbital and the projection of C-beta-C-gamma bond is equal to 60 degrees. The hyperfine coupling constants for alpha- and beta-fluorine atoms were determined. The hyperfine splitting constants for two equivalent beta-fluorine atoms were found to be 7.2 mT. The corresponding value for the two other equivalent fluorine atoms is 1.8 mT, whereas the hyperfine splitting due to alpha-fluorine atom is 23.8 mT.