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

ABSTRACT

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 SmC_SP_A 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.

Graphical abstract

KEYWORDS:

• Bent-core liquid crystals
• apex substitution
• terephthalate unit
• polar smectic phase
• polymorphism

Acknowledgements

The project was financially supported by the Czech Science Foundation (project No. 18-14497S), by the Czech Ministry of Education, Youth and Sports in Operational Programme Research, Development and Education financed by European Structural and Investment Funds [project No. SOLID21 - CZ.02.1.01/0.0/0.0/16_019/0000760].

Disclosure statement

The authors declare no conflict of interest.

Supplementary material

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Additional information

Funding

This work was supported by the Grantová Agentura České Republiky [18-14497S]; Ministerstvo Školství, Mládeže a Tělovýchovy [SOLID21 - CZ.02.1.01/0.0/0.0/16_019/0000760].