Mesomorphic properties of non-symmetric bent-core liquid crystals with a lateral substituent in the apex position

We present a new series of bent-core liquid crystals possessing a lateral substituent in the apex position of the central core and a terephthalate connecting unit in one elongating side arm. The synthesised materials have been studied by polarising optical microscopy, differential scanning calorimetry, dielectric spectroscopy and X-ray diffraction. Electro-optical studies have also been performed to confirm the character of the identified polar smectic phase. We document that materials substituted with fluorine exhibit polar synclininic antiferroelectric phase, for homologues with longer terminal alkyl chains, this SmCSPA phase is accompanied with a high-temperature SmC phase. Our results document that the introduction of the aforementioned structural features triggers significant modification of the mesomorphic behaviour previously observed for similar compounds.