Lactic acid derivatives with terphenyl molecular core

ABSTRACT

New lactic acid derivatives, based on terphenyl molecular core laterally substituted by chlorine atom, have been synthesised and their liquid crystalline properties studied. We varied the molecular structure by prolonging the non-chiral chain and analysed the mesogenic properties with respect to its length. We found that all new compounds reveal the SmA*–SmC* phase sequence in an extremely broad temperature interval. The experimental techniques, namely the polarising optical microscopy, differential scanning calorimetry, x-ray diffraction and helical pitch measurements, have been applied to establish the physical properties. Studied compounds exhibit very high values of the spontaneous polarisation and the tilt angle grows continuously on cooling up to 42°. The pitch values drop down when prolonging the molecular non-chiral chain.

GRAPHICAL ABSTRACT

KEYWORDS:

• Terphenyl molecular core
• lactic acid unit
• ferroelectric SmC* phase
• SmA phase

Acknowledgement

The authors acknowledge Dr. Oliva Pacherova for help with x-ray measurements.

Disclosure statement

No potential conflict of interest was reported by the authors.

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Additional information

Funding

This work was supported by the Czech Science Foundation [projects 15-02843S and 16-12150S], the Ministry of Education, Youth and Sports of the Czech Republic [project LD14007] and by an STSM Grant from COST Action IC1208.