| 摘要 |
<p>An object of the invention is to provide novel liquid crystalline compounds which 1) exhibit a low threshold voltage, 2) have a low viscosity, 3) maintain or lower dielectric anisotropy of liquid crystal compositions when added thereto, and further are excellent in miscibility with other known liquid crystalline compounds, particularly excellent in the miscibility at low temperatures; to provide liquid crystal compositions comprising the compound; and to provide liquid crystal display devices comprising the composition; and the liquid crystalline compounds are alpha , alpha -difluorobenzyl ether derivatives expressed by the general formula (1) <CHEM> wherein R<1> represents a straight chain or branched alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 15 carbon atoms one or not-adjacent two or more CH2 groups in the alkyl or alkenyl group may be replaced by oxygen atom; ring A and ring B independently represent 1,4-cyclohexylene group one or more CH2 groups on the ring may be replaced by oxygen atom or sulfur atom, or 1,4-phenylene group one or more CH groups on the ring may be replaced by nitrogen atom, and one or more hydrogen atoms on the ring may be replaced by a halogen atom; ring C and ring D independently represent 1,4-phenylene group one or more hydrogen atoms on the ring may be replaced by a halogen atom; Z<1>, Z<2>, and Z<3> independently represent -CH2CH2-, -CH=CH-, -C IDENTICAL C-, or single bond; X represents a halogen atom, CF3, OCF3, OCHF2, or CN; Y represents hydrogen atom or a halogen atom; l and m are 0 or 1; l + m </= 1; and an element which constitutes the compound may be replaced by its isotope.</p> |
