Variety of mesophases in compounds with an increasing number of lactate units in the chiral chain

Abstract

Liquid-crystalline compounds with different numbers of lactate units, n, in the chiral part were synthesised and mesomorphic properties studied. Physical properties were compared with respect to n. In the compound with one lactate unit in the chiral part the TGBA–TGBC–SmC* phase sequence was detected. For two lactate units the antiferroelectric SmC*_A phase occurs. Finally, three-lactate material exhibits the tilted hexatic SmI*(F*) phase below the ferroelectric SmC* phase. Dielectric spectroscopy and spontaneous tilt and polarisation were measured. For the three-lactate compound the temperature dependences were analysed in the vicinity of the SmC*–hexatic phase transition, and these properties compared with the theoretically predicted behaviour.

Keywords:

• smectic phases
• ferroelectricity
• lactate unit
• TGB phases
• hexatic phase

Acknowledgements

This work was financially supported by the Czech Science Foundation (project No. P204/11/0723) and bilateral Czech–Polish project No. M100101211. NP acknowledges grant SVV-2012-265303.