Synthesis and properties of antiferroelectric and/or ferroelectric compounds with the –CH₂O group close to chirality centre

ABSTRACT

Novel chiral three-ring compounds with the –CH₂O group close to chirality centre were synthesised and their properties were studied. The phase transitions and phase sequences were observed using a polarising optical microscope. The phase transition temperatures and enthalpies were checked by differential scanning calorimetry. A broad-frequency dielectric spectroscopy was also used to confirm the phase transition temperatures as well as the phase sequence. The helical pitch was measured by the spectrophotometry method. It was found that the compounds differing only in one lateral substituted fluorine atom create two different chiral tilted smectic phases, one a ferroelectric phase (SmC*) and the other an antiferroelectric phase (SmC_A*).

Graphical abstract

KEYWORDS:

• AFLCs
• FLCs
• synthesis
• phase transitions
• enthalpies
• helical pitch
• dielectric spectroscopy

Acknowledgments

I want to thank Mr. Kacper Tomala for the help with the synthesis of compounds.

Disclosure statement

No potential conflict of interest was reported by the authors.

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Funding

This work was supported by the Military University of Technology grant [RMN 08-972].