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.
一种光学活性的4-巯基
肉桂酸衍
生物,由通式(1)表示##STR1##其中,R1代表一个具有6到14个碳原子的烷基,烷氧基烷
硫基;X为H或F;Y为H或
CH3;n为0或1;Z为 或
CF3;R2代表C2-8烷基。该化合物可降低液晶温度范围并加宽,能够实现双稳态或三稳态手性液晶相。该化合物可单独使用或与具有液晶相或
铁电液晶的其他液晶混合,作为液晶器件的材料。还提供了一种制备方法、至少包含一种此类衍
生物的双稳态或三稳态液晶组合物,以及包括该液晶组合物的液晶显示器件。