Slow kinetics of phase transformation in a dipole-functionalized discotic liquid crystal

The kinetics of phase transformation from the liquid crystalline mesophase to the crystalline phase has been studied in a model dipole-functionalized hexabenzocoronene derivative by x-ray diffraction, solid state NMR recoupling techniques, and dielectric spectroscopy. These probes revealed long-lived metastability and an intermediate state involving a change in the unit cell prior to crystallization. The barrier properties were dominant and amount to 1 and 2.5 eV, respectively, for the unit cell transformation and crystallization processes. These effects should be considered in the design of discotic liquid crystals for electronic applications.