Comparative study of helical pitch and electro-optical behaviours of highly twisted SC* and Sc*α phases

Abstract

The helical pitch measurement of a new fluoro substituted tolan derivatives series have revealed a strong torsion in all the phases (SC*, TGBA, TGBC). The compound n=12 (FH/FH/HH-12BTMHC) exhibits an extremely small pitch value of about 0.06μm in the Sc* phase. Such a small pitch value has only been observed in the Sc*α phase of a thiobenzoate series. A comparative electro-optical and thermal pitch behaviour study of the Sc* and Sc*α phases is performed in order to know if the switching current peaks in the Sc*α phase are directly linked up to its structure.