Synthesis and Physical Properties of Novel Dimesogenic Compounds Possessing both Lateral and Terminal Polar Groups

We prepared a homologous series of non-symmetric dimesogenic compounds 1-(4- fluorophenyl)-4-{ω -{4-[4-(4-hexylphenyl)-2,3-difluorophenyl]phenyloxy}alkyloxy} benzene ( I-n ) and investigated the physical properties. For comparison, we also prepared a compound ( II-6 ) possessing a 4-(4-cyanophenyl)benzene unit instead of the 4-(4- fluorophenyl)benzene unit. All the compounds exhibited an enantiotropic nematic phase. When an electric AC field was applied, a striped pattern that was similar to Williams domain appeared in the nematic phases of compounds I-n , whereas such a pattern was not observed in the nematic phase of II-6 . We discuss structure-property correlations of the polar liquid crystal oligomers.