Fluoro-substitued alkenyl compounds, liquid crystal compositions, and liquid crystal display elements

摘要

The invention relates to a fluoro-substituted alkenyl compound represented by formula (1) wherein Y<1> , Y<2>, Y<3> and Y<4> are each independently H or F, provided that at least one of Y<1> and Y<2> is F; Q<1> is a single bond or an alkylene group of 1 - 20 carbon atoms, at least one -CH2- being optionally substituted by -O-, provided that two or more -O- are not adjacent to each other; Q<2> is a single bond or -C IDENTICAL C-; Rings A<1,> A<2> and A<3> are each independently a cyclohexane ring, a dioxane ring, a cyclohexene ring, a pyrimidine ring, a pyridine ring, or a benzene ring, or a benzene ring having at least one hydrogen atom substituted by F; Z<1,> Z<2> and Z<3> are each independently a single bond, -CH2CH2-, -CH2O-, -OCH2-, -COO-, -OCO-, -CH=CH-, -C IDENTICAL C-, -CF2O-, or -OCF2; and m and n are each independently 0 or 1; provided that Y<3> is F when Ring A<3> is a cyclohexane ring and Z<3> is a single bond. The liquid crystal composition comprising the compound, when used in liquid crystal display elements for various modes, excels in driving voltage and contrast.