Conjugated nitrile derivative, liquid crystal composition, and liquid crystal display elements

Abstract

Liquid crystalline compounds having a wide temperature range of liquid crystal phase, a high dielectric anisotropy, and a high optical anisotropy; and liquid crystal compositions and display devices containing the composition. The liquid crystalline compounds are conjugated nitrile derivatives expressed by the formula (1) ##STR1## wherein R represents an alkyl group or a fluoroalkyl group each having 1 to 10 carbon atoms, halogen atom, or cyano group provided that in the alkyl or fluoroalkyl group, one or not-adjacent two or more methylene or fluoromethylene groups may be replaced by oxygen atom or 1,2-ethenylene group; A.sub.1, A.sub.2, A.sub.3 and A.sub.4 represent 1,4-cyclohexylene group, 1,4-phenylene in which one or two hydrogen atoms on the ring may be replaced by fluorine atom, 1,3-dioxane-2,5-diyl, or pyrimidine-2,5-diyl; B.sub.1, B.sub.2, and B.sub.3 independently represent a covalent bond, 1,2-ethylene group, 1,2-ethenylene group, 1,2-ethynylene group, carbonyloxy group, methylenoxy group, or 1,4-butylene group; m, n, and p are 0 or 1; and G represents a group expressed by the formula ##STR2##

Dependencies are inferred from the claim text.