Abstract: Flourobenzyl ether derivatives of the formula ##STR1## and liquid crystalline mixtures which contain such compounds are prepared and employed in electro-optical display devices.

Abstract: Compounds of the formula ##STR1## wherein Z.sup.1 denotes a single covalent bond or --CH.sub.2 Ch.sub.2 --; ring A.sup.1 represents 1,4-phenylene, pyrimidine-2,5-diyl, pyridine-2,5-diyl or, when Z.sup.1 stands for --CH.sub.2 CH.sub.2 --, also trans-1,4-cyclohexylene; X.sup.1 stands for fluorine or chlorine; X.sup.2 signifies fluorine, chlorine or hydrogen, with the proviso that X.sup.2 only signifies hydrogen when X.sup.1 is chlorine or when ring A.sup.1 signifies pyridine-2,5-diyl and Z.sup.1 signifies --CH.sub.2 CH.sub.2 --; and R.sup.1 signifies 1E-alkenyl with 2 to 12 carbon atoms,their manufacture, liquid crystalline mixtures which contain these compounds and their use for electro-optical purposes.

Abstract: Compounds of the formula ##STR1## wherein Z.sup.1 is a single covalent bond or --CH.sub.2 CH.sub.2 --, X.sup.1 is hydrogen, fluorine or chlorine and R.sup.1 is 1E-alkenyl with 2 to 12 carbon atoms,their preparation, liquid crystalline mixtures which contain these compounds and their use for electro-optical purposes.

Abstract: There is described compounds of the formula ##STR1## wherein X stands for CH and Y stands for N or X stands for N and Y stands for CH; A.sup.1 and A.sup.2 signify single covalent bonds or one of the groups A.sup.1 and A.sub.2 also signifies trans-1,4-cyclohexylene, cis-4-cyano-trans-1,4-cyclohexylene or 1,4-phenylene optionally substituted with halogen or methyl; ring B represents trans-1,4-cyclohexylene, 1,4-phenylene optionally substituted with halogen or methyl or, when A.sup.2 signifies a single covalent bond, also cis-4-cyano-trans-1,4-cyclohexylene; R.sup.1 denotes an optionally halogen-substituted alkyl or alkenyl group in which optionally one CH.sub.2 group or two non-adjacent CH.sub.2 groups is/are replaced by --O--, --COO-- and/or --OOC--; R.sup.2 signifies an optionally halogen-substituted alkyl or alkenyl group in which optionally one CH.sub.2 group or two non-adjacent CH.sub.2 groups is/are replaced by --O--, --COO-- and/or --OOC-- or R.sup.

Abstract: A liquid crystalline mixture comprising(a) at least one compound of the formula: ##STR1## wherein R.sup.1 is alkyl, alkoxy, p-alkylphenyl, p-alkoxyphenyl, trans-4-alkylcyclohexyl, 4'-alkyl-4-biphenylyl, p-(trans-4-alkylcyclohexyl)phenyl, 2-(trans-4-alkylcyclohexyl)ethyl or p-[2-(trans-4-alkylcyclohexyl)ethyl]phenyl and R.sup.2 is trans-4-alkylcyclohexyl; or R.sup.1 is trans-4-alkylcyclohexyl and R.sup.2 is p-(trans-4-alkylcyclohexyl)phenyl, p-[2-(trans-4-alkylcyclohexyl)ethyl]phenyl or 4'-(trans-4-alkylcyclohexyl)-4-biphenylyl; or R.sup.1 is p-alkylphenyl and R.sup.2 is p-[2-(trans-4-alkylcyclohexyl)ethyl]phenyl; and the alkyl and alkoxy groups in the substituents R.sup.1 and R.sup.2 are straight-chain groups of 1 to 7 carbon atoms, and;(b) at least one dichroic coloring substance selected from the group of compounds consisting of: ##STR2## wherein R.sup.3 is straight-chain C.sub.1 -C.sub.12 -alkyl and R.sup.4 is straight-chain C.sub.1 -C.sub.4 -alkyl, Z.sup.1 is hydrogen or chlorine, one of the symbols Z.

Abstract: Liquid crystal mixtures containing a coloring substance which comprise about 5 to about 40 weight % of trans-p-[5-(4-alkylcyclohexyl)-2-pyrimidinyl]benzonitriles, about 10 to about 60 weight % of trans-4-alkylcyclohexane carboxylic acid phenyl esters and about 0.1 to about 15 weight % of one or more coloring substances of the formula ##STR1## wherein m stands for the number 1 and X is alkoxy and Y is nitro; or m stands for the number 1 or 2; and X is p-alkoxyphenyl and Y is nitro or dialkylamino, or X is alkoxy and Y is -p-nitrophenyl or -(dialkylamino)phenyl; or m stands for the number 2, and X is alkoxy and Y is alkoxy, nitro or dialkylamino, or both X and Y are dialkylamino; and wherein the alkoxy denotes a straight-chain group containing 1 to 12 carbon atoms and the alkyl groups in the dialkylamino each denote a straight-chain alkyl group containing 1 to 4 carbon atoms are described.

Abstract: Liquid crystalline mixtures comprising trans-phenyldioxane, phenylpyrimidine and phenylbenzoate compounds which are useful in electro-optical apparatuses are disclosed.

Abstract: Liquid crystal mixtures having positive anisotropy of the dielectric constants comprising a nematogenic material having a clearing point above 60.degree. C., one or more compounds of the formula ##STR1## wherein R.sub.1 and R.sub.2 are hydrogen or straight-chain alkyl, provided that at least one of R.sub.1 and R.sub.2 is other than hydrogen and that R.sub.1 and R.sub.2 together contain no more than 9 carbon atoms,and, if desired, one or more additional doping agents, are described.