Anisotropy of indirect couplings and accurate molecular structures of 1,2- and 1,3-difluorobenzenes by combined analysis of gas electron diffraction, rotational spectroscopy and liquid crystal NMR data

In the combined analysis of gas-phase electron-diffraction scattering data, rotation constants and dipolar coupling constants from NMR experiments in liquid crystal solvents, not only are high-accuracy molecular structures of 1,2- and 1,3-difluorobenzene obtained, but the anisotropic components of some of the CF and FF indirect couplings have been deduced directly from the experimental data. The benefits of combined analyses of data from several different experimental techniques, and factors influencing the accuracy of structures determined in this way, are discussed.