Abstract
In the continuation of our study on heterocyclic mesogens, the structural motif of a 2,5-disubstituted benzothiophene as the central unit was utilised to design novel liquid crystals. Despite the bent molecular structure, the formation of a standard calamitic phase was observed. The mesomorphic properties of the model substances of series I was very close to that of the previously studied 6-substituted derivatives. Introduction of the chiral terminal unit led to appearance of the ferroelectric smectic C* (SmC*) phase in compounds IIa–d. 5-Phenylbenzothiophene based mesogens III exhibited higher clearing temperatures and polymorphism (nematic–smectic A–SmC sequence). Thus, the central benzothiophene unit can be successfully utilised in the design of various liquid crystals.
Acknowledgements
This project was supported by the Czech Science Foundation (project no. 202/09/0047 and P204/11/0723) and the Ministry of Education, Youth and Sports of the Czech Republic (project no. MSM6046137301).