Optically active 4-mercaptocinnamic acid derivatives, preparation method thereof and use thereof

Abstract

An optically active 4-mercaptocinnamic acid derivative represented by general formula (1) ##STR1## wherein R.sup.1 represents an alkyl group, an alkoxy group alkylthio group having 6 to 14 carbon atoms; X is H or F; Y is H or CH.sub.3 ; n is 0 or 1; Z is CH.sub.3 or CF.sub.3 ; and R.sup.2 represents a C.sub.2-8 alkyl group, preparation method, bistable or tristable liquid crystal composition containing at least one such derivative, and a liquid crystal display device including such a liquid crystal composition. The compound of general formula (1) decreases liquid crystal temperature range and broadens it, and enables realizing a bistable or tristable chiral smectic phase. The compound can be used alone or as blended with other liquid crystals having a smectic phase or ferroelectric liquid crystals as a material for liquid crystal devices.

Dependencies are inferred from the claim text.