We investigated phase behavior, self-assembled structure and electric responsivity of a liquid crystal (LC) compound bearing 1,3-dioxane unit in the mesogen core part (DIO) by differential scanning calorimetry, polarized optical microscopy, X-ray diffraction, dielectric relaxation, polarization switching and second harmonic generation (SHG) studies, and also proposed a possible mechanism why DIO showed the anomalously large dielectric permittivity Δεwhich was several thousand at 10 kHz and more than 10 thousand at 1 kHz in a specific mesophase MP.

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Cybotactic nematic phase (Ncyb) has attracted much attention; however, almost all molecules under investigation have had a bent-shaped structure or mixture of rod and disc shaped molecules. Recently, a U-shaped compound possessing two 1,4-diphenyl-2,3-difluorobenzene units was found to exhibit an Ncyb phase with a temperature range of 20 K and an semctic C (SmC) phase [1]. Also, the rod-like compound, 4-[4-(6-hydroxyhexyloxy)phenyl]-1-(4-hexyloxyphenyl)-2,3-difluorobenzene, was found to exhibit an Ncyb with a temperature range of 25 K and an SmC phase. Dielectric spectroscopic studies have been performed to investigate the molecular dynamics of U-shaped and rod shaped Ncyb nematic phases. Electric field induced Ncyb-SmC phase transition temperature has been observed. Moreover, application of external electric phases induces a collective mode relaxation process in U-shaped Ncyb phase.

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