2 H and 14 N Nmr of Cetylpyridinium Bromide Lyotropic and Thermotropic Liquid Crystals

2 H and 14 N NMR spectra of the cationic head group have been recorded for liquid crystalline systems of CPB (cetylpyridinium bromide), pentanol and NaBr brine, at low surfactant content. The 2 H quadrupolar splittings provided the order parameters of the aromatic ring at various temperatures. Using these order parameters, the experimentally determined 14 N quadrupolar splittings allowed the evaluation of the principal values of the nitrogen quadrupole coupling tensor, |C Q | = 0.41MHz and η = 0.39. 2 H quadrupolar splittings measured for the thermotropic liquid crystal given by pure CPB above 71°C allowed to calculate the ring order parameters also for this phase. These parameters and the 14 N |C Q | and η values led to 14 N splitting values in very good agreement with those actually observed for this thermotropic ionic liquid crystal.