Electron spin resonance spectra of tetrafluoroethylene radical cation

Abstract

Exposure of a solid solution of FCCl3 containing C2F4 to γ-rays at 77 K gave a species whose e.s.r. spectrum comprised an anisotropic quintet attributed to hyperfine coupling to the four equivalent fluorines of the C2F4 radical cation. An extra, small doublet splitting is assigned tentatively to the fluorine of a matrix molecule interacting with the radical cation. INDO calculations show that the radical cation has a planar structure with the unpaired electron in the bonding π orbital, the estimated 19F coupling constants being in good agreement with the experimental data.