Novel smectic liquid crystals based on benzo[c]cinnoline: their synthesis, mesomorphism, opto- and electro-chemical properties

ABSTRACT

A series of novel calamatic liquid crystals based on a polar benzo[c]cinnoline moiety were efficiently prepared through a facile route. Rich smectic mesophases were induced by the monoalkylated and dialkylated molecular design, including highly ordered smectic mesophases in the rectangular and hexagonal orders. Dialkylated phenylbenzocinnoline derivatives showed a very wide temperature range over 150°C for smectic C (SmC) phase, while the monoalkylated ones only presented the low-ordered mesophases, which exhibited a bilayer structure in crystalline phase. From pronounced reversible redox waves in a cyclic voltammogram and low-lying lowest unoccupied molecular orbital level of about −3.2 eV indicated possible electron-transporting behaviour. In addition, a switching behaviour originating from ferroelectricity in SmC* induced by chiral dopant was observed.

GRAPHICAL ABSTRACT

KEYWORDS:

• Smectic liquid crystals
• benzo[c]cinnoline
• smectic C phase
• a wide temperature range
• ferroelectricity

Acknowledgements

We thank Ms Y. Takayashiki, and Dr A. Ohno for very useful discussion. This work is supported by CREST under the JST Strategic Basic Research Programs sponsored by Japan Science and Technology Agency.

Disclosure statement

No potential conflict of interest was reported by the authors.

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Funding

This work is supported by CREST under the JST Strategic Basic Research Programs sponsored by Japan Science and Technology Agency.