An algorithm for analysing NMR data of nematic liquid crystals applied to the aromatic core of para-azoxyanisole

An algorithm is proposed to analyse the whole set of proton and deuterium NMR data associated with the aromatic core of nematic para-azoxyanisole (PAA) in terms of a model in which the molecular non-rigidity is described as internal rotations within a single mean conformation. It is shown that this set is not sufficient to completely determine this conformation and its order. Taking this feature into account, the actual uncertainties which affect our knowledge of various conformation and motion parameters at both ring and molecular length scales are estimated. There is no evidence of the existence of very different conformations in the nematic phase and we clearly prove that, in all cases, the molecular order matrix remains biaxial.