Structures of 1,3,5-trichloro- and 1,3,5-trichlorotrifluorobenzene derived from n.m.r. spectra of nematic solutions

Abstract

It is shown that the anisotropic coupling constants previously determined from the ¹³C satellite proton n.m.r. spectrum of a nematic solution of 1,3,5-trichlorobenzene are consistent with a satisfactory structure provided that allowance is made for harmonic vibrational motion. The ¹³C satellite ¹⁹F spectra of 1,3,5-trichlorotrifluorobenzene have been analysed, and in this case vibrational averaging of the dipolar couplings has a negligible effect on the derived structure. There are, however, small but significant contributions to the total anisotropic couplings from the anisotropic components of the indirect, electron-coupled interactions.