Liquid crystal phase

Abstract

Liquid crystal phases containing at least one optically active compound of the formula I R.sup.1 --X.sup.1 --CHR.sup.o (CH.sub.2).sub.p X.sup.2 --R.sup.2 I wherein X.sup.1 and X.sup.2 independently of one another are each --CO--O-- or --O--CO--, one of X.sup.1 and X.sup.2 may also be --O--, R.sup.1 and R.sup.2 independently of one another are each a group --(A.sup.1 --Z).sub.m --(A.sup.2).sub.n -Y, wherein A.sup.1 and A.sup.2 in each case independently of one another are a 1,4-phenylene, pyrimidine-2,5-diyl, pyrazine-2,5-diyl, pyridine-2,5-diyl, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,3-dithiane-2,5-diyl or 1,4-bicyclo(2,2,2)-octylene group, it also being possible for this to be monosubstituted or polysubstituted by F, Cl, Br, CN and/or alkyl groups with up to 12 C atoms, and it being possible for 1 or 2 non-adjacent CH.sub.2 groups in the alkyl groups to be replaced by O atoms, Z is --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.2 O--, --CH.dbd.N--, --N.dbd.CH--, --N.dbd.N--, --N(O).dbd.N-- or a single bond, m and n in each case independently of one another are O, 1 or 2, Y is independently of one another a straight-chain or branched alkyl group with up to 12 C atoms, it being possible for 1 or 2 non-adjacent CH.sub.2 groups to be replaced by O atoms, or, if n is 1 or 2, also F, Cl, Br or CN, R.sup.0 is an alkyl group with up to 5 C Atoms or a phenyl group or a cyclohexyl group, display largely temperature-independent electrooptical parameters.

Dependencies are inferred from the claim text.