FLUORINATED ALKYL ETHER COMPOUNDS, LIQUID-CRYSTAL COMPOSITIONS, AND LIQUID-CRYSTAL DISPLAY DEVICES

摘要

Liquid-crystal compounds which are excellent in compatibility with other liquid-crystal materials particularly even at low temperatures, have a high voltage retention and a low threshold voltage, are lowered in the temperature dependence of these characteristic values, have a high DELTA n value, and exhibit liquid-crystal properties over a wide temperature range, the compounds being represented by the general formula: Ra-A1-Z1-A2-Z2-(-A3-Z3-)m-A0-Rf (wherein m is 0 or 1; A0, A1, A2 and A3 are each a six-membered ring, with A0 being 1,4-phenylene which may be substituted with one to three fluorine and/or chlorine atoms and A1, A2 and A3 being selected each independently from among trans-1,4-cyclohexane, optionally halogenated 1,4-phenylene, cyclohexene-1,4-diyl and 1,3-dioxane-2,5-diyl; Z1, Z2 and Z3 are each independently a bridge between rings and selected from among -(CH2)2-, -(CH2)4-, -CH2O- and -OCH2- which may be halogenated, and single bond (-); Rf is -OCF2CF2H or -OCF2CFHCF3; and Ra is a C1-C20 linear or branched monovalent organic group); liquid-crystal compositions comprising at least one of the compounds; and liquid-crystal display devices made by using the compositions.