Difluoroethylene compounds and liquid crystal compositions containing them

Abstract

A difluoroethylene compound of the following formula (1): R.sup.1 --(A.sup.1).sub.m --Y.sup.1 --A.sup.2 --CF.dbd.CF--A.sup.3 --Y.sup.2 --(A.sup.4).sub.n --R.sup.2 (1) wherein A.sup.3 is a trans-1,4-cyclohexylene group, and each of A.sup.1, A.sup.2 and A.sup.4, which are independent from one another, is a trans-1,4-cyclohexylene group or a 1,4-phenylene group, wherein each of such cyclic groups is unsubstituted or substituted by one or more halogen atoms or cyano groups, one or more .dbd.CH-- groups constituting rings of such cyclic groups may be substituted by nitrogen atoms, and one or more --CH.sub.2 -- groups constituting rings of such cyclic groups may be substituted by oxygen atoms or sulfur atoms.

Dependencies are inferred from the claim text.