An optically active compound represented by formula (I): ##STR1## wherein R.sup.1 represents an alkyl group having from 6 to 18 carbon atoms or an alkoxy group having from 6 to 18 carbon atoms; A represents ##STR2## or ##STR3## wherein ring ##STR4## represents a nitrogen-containing hetero-aromatic ring; n and m each represents 0 or 1; R.sup.2 represents an alkyl group having from 1 to 12 carbon atoms; and C* is an asymmetric carbon atom. The compound of formula (I) exhibits excellent physicochemical stability, a low temperature range for the chiral smectic C phase when used either alone or in combination with other compounds, and a rapid response.
化学式(I)所代表的光学活性化合物:##STR1## 其中,R1代表具有6至18个碳原子的烷基基团或具有6至18个碳原子的烷氧基团;A代表##STR2##或##STR3##其中环##STR4##代表含氮杂环芳香环;n和m各自代表0或1;R2代表具有1至12个碳原子的烷基基团;C*为不对称碳原子。化合物(I)表现出优异的物理
化学稳定性,在单独使用或与其他化合物组合使用时,具有较低的手性液晶C相温度范围和快速响应。