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.