| 摘要 |
Liquid crystalline compounds are disclosed which have large dielectric anisotropy and relatively low viscosity, and which are represented by formula (1) wherein R1 represents hydrogen or C1-C15 alkyl in which one or more non-adjacent methylene may be replaced by oxygen, sulfur or -CH=CH- and one or more hydrogen may be replaced by halogen; R2 represents hydrogen, cyano, halogen or C1-C15 alkyl in which one or more non-adjacent methylene may be replaced by oxygen, sulfur or -CH=CH- and one or more hydrogen may be replaced by halogen; L represents halogen or hydrogen; A1, A2, A4 and A5 each independently represent trans-1,4-cyclohexylene or 1,4-phenylene, one or more -CH2- in the trans-1,4-cyclohexylene may be replaced by oxygen or sulfur, one or more =CH- in the 1,4-phenylene may be replaced by nitrogen, and one or more hydrogen in the 1,4-phenylene ring may be replaced by halogen; A3 represents trans-1,4-cyclohexylene in which one or more -CH2- may be replaced by oxygen or sulfur; Z1, Z2, Z3 and Z4 each independently represent -COO-, -OCO-, -CH2CH2-, -(CH2)4-, -CH2O-, -OCH2-, -CF2O-, -OCF2- or a single bond; Q represents -CF2CH2- or -CH2CF2-; and k, l, m and n each independently represent 0 or 1 with the condition of k+l+m+n<=2. Further, liquid crystal compositions comprising at least one liquid crystalline compound of formula (1) and liquid crystal display devices composed of the compositions are disclosed.
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