Antiferroelectric liquid crystal from a banana-shaped achiral molecule

A new banana-shaped achiral compound, 1,3-phenylene bis[4-(3-fluoro-4-n-octyloxyphenyliminomethyl) benzoate] ( PBFOB) was synthesized and its antiferroelectric liquid crystallinity determined. The PBFOB was characterized by differential scanning calorimetry, X-ray diffractometry in the small and wide angle regions, and polarizing optical microscopy; its polarization and antiferroelectric properties were also investigated. The presence of a lateral fluoro-substituent in the banana-shaped achiral molecules containing a Schiff's base mesogen induced a decrease in melting temperature and formation of the switchable smectic B-2 phase in the melt. The spontaneous polarization for PBFOB was about 250 nC cm(-2) and the polarization of this phase switched on the reversal of an applied electric field.