Evidence for an anisotropic contribution to ³J_FF from the ¹⁹F N.M.R. spectrum of hexafluorocyclopropane dissolved in a nematic phase

Abstract

Analysis of the fluorine N.M.R. spectrum of a sample of hexafluorocyclopropane dissolved in p-ethoxybenzylidene-p-n-butylaniline (EBBA) has given the magnitudes and relative signs of three anisotropic and three isotropic coupling constants. The anisotropic couplings ² T _FF and ³ T _FF(cis) appear to be entirely dipolar in origin, whereas the value of ³ T _FF(trans) can be considered as 86 per cent dipolar, the remaining 14 per cent being attributed to an anisotropy in the electron-coupled spin-spin interaction.