Ferrielectric smectic C phases stabilized using a chiral liquid crystal oligomer.

A chiral liquid crystal oligomer, (R)-1-methylheptyl 4'-{8-[4-(5-octylpyrimidin-2-yl)phenyloxy]octanoyloxy}biphenyl-4-carboxylate, was prepared. Its physical properties were investigated using optical microscopy, differential scanning calorimetry, and X-ray diffraction. The oligomer was found to exhibit two ferrielectric smectic C phases with a wide temperature range between ferroelectric and antiferroelectric smectic C phases. Furthermore, ferrielectric-like ordering was observed in a racemic mixture of the enantiomers. The oligomeric effect can produce highly chirality-dependent ordering in the racemic system.