NMR investigation of a thermotropic liquid crystal showing isotropic-isotropic'-(columnar)-cubic phase transitions.

In this work, we report a first detailed study of the mesophasic behaviour of the calamitic liquid crystal, a (4,4′-bis(4″-carboxybelzyloxy)biphenyl derivate, labelled 9/2 RS/RS, showing an isotropic-isotropic-(columnar)-cubic phase behaviour on cooling.1H NMR diffusometry allowed to distinguish between the two isotropic phases in terms of diffusion characterized by different Arrhenius activation energy, while13C NMR static measurements and2H NMR investigations were of help in understanding the orientational ordering properties of the metastable columnar phase and confirmed the isotropic state of the sample in the cubic phase. [ABSTRACT FROM AUTHOR]