A new type of five-ring banana-shaped mesogens with strong dielectric response

Abstract

Three new homologous bent-shaped mesogens with terminal octyloxy P8, decyloxy P10 and dodecyloxy P12 groups were synthesized. Calorimetric, X-ray and electro-optic investigations prove the existence of two mesophases of the SmCP_A type for compound P10 but only one SmCP_A phase for the homologues P8 and P12. The static dielectric permittivities of compound P12 and that of the low-temperature phase of substance P10 are in the order of 30 and agree with results on bent-core mesogens published before. Surprisingly, the dielectric permittivities of P8 and of the high-temperature phase of P10 are of about 1000. We explain this extremely high dielectric response with the soft reaction of ferroelectric units in the external electrical field.

Keywords:

• liquid crystals
• bent-shaped molecules
• antiferroelectric phases

Acknowledgements

The authors are indebted to the DFG (project Kr 1182/14 and the GRK 894 for financial support.