High-resolution proton and fluorine resonance spectra of para -fluoro-aniline

Abstract

The proton and fluorine resonance spectra of liquid para-fluoro-aniline have been measured under resolving power of about 1 in 10$^{8}$. The spectra are complicated, because the chemical shifts between the protons adjacent to the fluorine atom and those adjacent to the amino group are comparable with the various spin-coupling constants between the four protons and between the protons and the fluorine. The proton spectrum is of the type known as A$_{2}$B$_{2}$X, and an analysis for the energy levels and the 64 transitions is given. The proton and fluorine resonance spectra are interpreted in terms of this analysis, and the chemical shifts and spin-spin-coupling constants are determined.