SYNTHESIS AND FERROELECTRIC PROPERTIES OF LATERALLY SUBSTITUTED FLUORO LIQUID-CRYSTALS DERIVED FROM 4-MERCAPTOBENZOIC ACID

Several new ferroelectric liquid crystals with thiobenzoate mesogenic cores have been synthesized and the influence of a single fluorine atom ortho to the alkyloxy tail on the mesomorphic properties of some two and three benzene ring core compounds has been studied. The two benzene ring derivatives do not display the ferroelectric smectic C phase but the three phenyl ring compounds exhibit a wide temperature range S(C)* phase. The transition temperatures and enthalpies of transition for these compounds have been determined, the spontaneous polarization, response time and tilt angle have also been measured and are discussed as a function of the structure near to the chiral centre.