Proton and fluorine N.M.R. spectra of fluorobenzene

Abstract

Proton and fluorine resonance spectra of fluorobenzene have been obtained under high resolution using a Varian spectrometer operating at 100 Mc/s and 94·1 Mc/s respectively. These have been analysed by treating the molecule as a six-spin system off the type AB ₂ C ₂ X with C _2v symmetry. The best parameters available were used to solve the secular equation using an IBM 1620 computer. Carbontetrachloride, chlorform, dioxan and benzene were used as solvents and spectra were obtained at different concentrations. Both ¹H and ¹⁹F spectra show concentration dependence. Splittings of the spectra due to the natural abundance of ¹³C were observed. The coupling constants J _13C-H and J _13C-F have the values 160·0± 2·0 c/s and 265·5± 2·0 c/s respectively.