The present invention provides liquid crystalline compounds having a very high voltage holding ratio, very little variation of these properties depending on temperature, high &Dgr;n, and good compatibility in the other liquid crystal materials particularly under a low temperature, liquid crystal compositions containing these crystalline compounds, and liquid crystal display devices constituted by using the liquid crystal compositions. The liquid crystalline compounds are represented by general formula (1):
wherein R represents an alkyl, alkoxy or alkoxyalkyl group of 2-20 carbon atoms, and in each group, any 1-3 hydrogen atoms may be replaced by fluorine atoms; X shows an halogen atom or an alkyl group of 1-20 carbon atoms, any methylene groups (—CH2—) not adjacent each other in the alkyl group may be replaced by oxygen atoms, and any one or more hydrogen atoms in the alkyl group may be replaced by fluorine atoms; Z1, Z2 and Z3, each independently, represents —(CH2)2—, —(CH2)4—, —CH2O—, —OCH2—, —(CH2)3O—, —O(CH2)3— or a covalent bond; Y1-Y16 each independently represent hydrogen atoms or fluorine atoms, but at least two represent fluorine atoms; m represents 0 or 1, and any atom constituting the compound may be replaced by an isotope thereof.
本发明提供了具有非常高的电压保持比、在不同温度下性质变化非常小、高&Dgr;n和在其他液晶材料中具有良好相容性(特别是在低温下)的液晶化合物、含有这些晶体化合物的液晶组合物,以及使用液晶组合物构成的液晶显示装置。液晶化合物由通式(1)表示:其中R表示2-20碳原子的烷基、烷氧基或烷氧基烷基,并且在每个基团中,任意1-3个氢原子可以被
氟原子替换;X表示卤素原子或1-20碳原子的烷基,烷基中不相邻的任何亚甲基(—
CH2—)可以被氧原子替换,并且烷基中的任意一个或多个氢原子可以被
氟原子替换;Z1、Z2和Z3分别独立地表示—( )2—、—( )4—、— O—、—O —、—( )3O—、—O( )3—或共价键;Y1-Y16各自独立地表示氢原子或
氟原子,但至少有两个表示
氟原子;m表示0或1,化合物中的任何原子都可以被其同位素替换。