Liquid crystal phase

A method for achieving temperature compensation in a liquid crystal display element containing a liquid crystal phase, comprising including in said phase at least 0.05% of at least one chiral compound having at least two chiral centers which are adjacent or separated from one another by an acyclic chain, wherein said chiral compound is of the formula

• R.sup.1 --CHCH.sub.3 --CHCH.sub.3 --R.sup.2
• wherein
• R.sup.1 and R.sup.2 independently of one another are each --Z.sup.1 --(A.sup.1).sub.m --Z.sup.2 --(A.sup.2).sub.n --Y, wherein A.sup.1 and A.sup.2 in each case independently of one another are 1,4-phenylene, pyrimidine-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, or one of said groups mono-substituted or poly-substituted by F, Cl, Br, CN, alkyl of up to 12 C. atoms, or C.sub.1-12 alkyl wherein 1 or 2 non-adjacent CH.sub.2 groups are replaced by 0 atoms,
• Z.sup.1 is --O--CO--, --CO--O--, --O-- or a single bond,
• Z.sup.2 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 0, 1 or 2 with the proviso that in each of R.sup.1 and R.sup.2, one of m and n is not zero when Z.sup.1 and Z.sup.2 are both single bonds, and
• Y is alkyl of up to 12 C atoms, or C.sub.1-12 -alkyl wherein 1 or 2 non-adjacent CH.sub.2 groups are replaced by 0 atoms, or, if n is 1 or 2, Y can also be F, Cl, Br or CN.

A method for rendering the electro-optical properties of a liquid crystal phase essentially independent of temperature comprising adding thereto at least 0.05% of at least one chiral compound having at least two chiral centers which are adjacent or separated from one another by an acyclic chain, wherein said chiral compound is of the formula

• R.sup.1 --CHCH.sub.3 --CHCH.sub.3 --R.sup.2
• wherein
• R.sup.1 and R.sup.2 independently of one another are each --Z.sup.1 --(A.sup.1).sub.m --Z.sup.2 --(A.sup.2).sub.n --Y, wherein A.sup.1 and A.sup.2 in each case independently of one another are 1,4-phenylene, pyrimidine-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, or one of said groups mono-substituted or poly-substituted by F, Cl, Br, CN, alkyl of up to 12 C atoms, or C.sub.1-12 alkyl wherein 1 or 2 non-adjacent CH.sub.2 groups are replaced by 0 atoms,
• Z.sup.1 is --O--CO--, --CO--O--, --O-- or a single bond,
• Z.sup.2 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 0, 1 or 2 with the proviso that in each of R.sup.1 and R.sup.2, one of m and n is not zero when Z.sup.1 and Z.sup.2 are both single bonds, and Y is alkyl of up to 12 C atoms, or C.sub.1-12 -alkyl wherein 1 or 2 non-adjacent CH.sub.2 groups are replaced by 0 atoms, or, if n is 1 or 2, Y can also be F, Cl, Br or CN.