Abstract: Nitrogen-containing heterocyclic compounds of the formula IR.sup.I --(A--Z).sub.n --A--R.sup.2 Iwherein R.sup.1 and R.sup.2 in each case independently of one another are alkyl group with 1-15 C atoms, wherein one or two non-adjacent CH.sub.2 groups can also be replaced by 0 atoms and/or --CO-- group and/or --O--CO-- groups and/or --CO--O-- groups, and one of the radicals R.sup.1 and R.sup.2 can also be H, CN, F, Cl or Br, the groups A in each case independently of one another are a 1,4-phenylene group, wherein one or two CH groups can also be replaced by N atoms, a 1,4-cyclohexylene group, wherein one or two CH.sub.2 groups which are not adjacent can be replaced by 0 atoms, a 1,3-dithiane-2,5-diyl group, a 1,4-bicyclo(2,2,2)-octylene group, a decahydronapthalene-2,6-diyl group or a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, the group Z in each case independently of one another are --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.

Abstract: Bicyclooctane derivatives of the formula IR.sup.1 --A.sup.1 --A.sup.2 --R.sup.2 IwhereinR.sup.1 and R.sup.2 independently of one another are each an alkyl group which has 1-12 C atoms and in which it is also possible for one or two non-adjacent CH.sub.2 groups to be replaced by O atoms and/or CO groups and/or --O13 CO groups and/or --CO--O groups and/or --CH.dbd.CH-- groups, one of the radicals R.sup.1 and R.sup.2 being also --A.sup.3 --R.sup.3,A.sup.1 is a 1,4-cyclohexylene group which is unsubstituted or substituted in the 1-position and/or 2-position and/or 3-position and/or 4-position by alkyl which has in each case 1-5 C atoms and is unsubstituted or substituted or fluorinated, and in which it is also possible for one or two non-adjacent CH.sub.2 groups to be replaced by one or two different groupings from the group --O--, --CO--, --CH.dbd.CH--, --S--, --SO-- or --SO.sub.2 --, or is substituted by F, Cl, Br, CN and/or CHO,A.sup.2 is a 1,4-bicyclo[2.2.2] octylene group,--A.sup.3 --R.sup.3 is --Cy--R.sup.

Abstract: A Cyclohexylbiphenyl of the formula ##STR1## wherein R.sub.1 is alkyl of 1-12 C atoms;R.sub.6 is alkyl or alkoxy each of 1-12 C atoms, CN or fluorine; andR.sub.2, R.sub.3, R.sub.4 and R.sub.5 each is hydrogen or fluorine, with the proviso that at least one, but not more than two of R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are fluorine.

Abstract: Cyclohexane derivatives of formula IR.sup.1 --(A.sup.1).sub.m --Z.sup.1 --A--Z.sup.2 --(A.sup.2).sub.n --R.sup.2 Iwherein R.sup.1 and R.sup.2 are each H, an alkyl group which has 1-10 C atoms and in which one or two CH.sub.2 groups can also be replaced by O atoms, F, CL, Br, CN or --O--COR, A.sup.1 and A.sup.2 are each 1,4-phenylene, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, piperidine-1,4-diyl, 1,4-bicyclo(2,2,2)-octylene or pyrimidine-2,5-diyl groups which are unsubstituted or substituted by 1-4 F atoms, A is a 1,4-cyclohexylene group which is substituted in the 1-position and/or 4-position by alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy, each of which has 1-5 C atoms, F, Cl, Br and/or CN and which can also carry 1 or 2 further F, Cl or Br atoms and/or CN groups, Z.sup.1 and Z.sup.2 are each --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.

Abstract: A phenylcyclohexene of the formula ##STR1## wherein n is 1 or 2, X is --H, --R, --OR, --OCOR, --OCOOR, --CF.sub.3 or --F, and when n is 1, X can also be ##STR2## R is alkyl of 1-8 C atoms and when two R groups are present they can be the same or different, has valuable liquid crystalline properties.

Abstract: A liquid crystal composition comprising, as the essential components, trans-4-n-propyl-(4-ethylphenyl)-cyclohexane, trans-4-n-propyl-(4-cyanophenyl)-cyclohexane, trans-4-n-pentyl-(4-cyanophenyl)-cyclohexane, trans-4-n-pentyl-(4'-ethylbiphenyl-4)-cyclohexane and 4-(trans-4-n-pentylcyclohexyl)-4'-(trans-4-n-propylcyclohexyl)-biphenyl is drivable over a wide temperature range and can be operated rapidly at low temperatures.

Abstract: A liquid crystal composition comprising trans-4-n-propyl-(4-ethylphenyl)-cyclohexane, trans-4-n-pentyl-(4-cyanophenyl)-cyclohexane, trans-4-n-pentyl-(4' -ethylbiphenyl-4)cyclohexane, trans-4-n-pentyl-(4'-cyanobiphenyl-4)-cyclohexane, 4-n-propylphenyl-4-(trans-4-n-propylcyclohexyl)benzoate, and 4-(trans-4-n-pentyl-cyclohexyl)-4'-(trans-4-n-propylcyclohexyl)-biphenyl is drivable over a wide temperature range and can be operated rapidly at low temperatures.

Abstract: Compounds of the formula ##STR1## wherein R.sub.1 and R.sub.2 are identical or different and each is alkyl or alkoxy each of up to 8 C atoms, and one or two of the substituents X are fluorine and the others are hydrogen are valuable liquid crystalline materials.

Abstract: A Cyclohexylbiphenyl of the formula ##STR1## wherein R.sub.1 is alkyl of 1-12 C atoms;R.sub.6 is alkyl or alkoxy each of 1-12 C atoms, CN or fluorine; andR.sub.2, R.sub.3, R.sub.4 and R.sub.5 each is hydrogen or fluorine, with the proviso that at least one, but not more than two of R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are fluorine.

Abstract: Liquid-crystalline tetrahydroquinazolines of the formula ##STR1## wherein R.sub.1 is alkyl, alkoxy, alkanoyloxy or alkoxycarbonyloxy of up to 8 carbon atoms in each case, CN, CF.sub.3, halogen or NO.sub.2 ; and R.sub.2 is alkyl of up to 10 carbon atoms are valuable components for liquid crystalline dielectrics.

Abstract: Cyclohexylphenyl derivatives of the formula ##STR1## wherein X is --CH.sub.2 --CH.sub.2 --, --CH.sub.2 --O--, --CH.sub.2 --S--, --O--CH.sub.2 -- or --S--CH.sub.2 --; R.sub.1 is alkyl of up to 8 carbon atoms; R.sub.2 is alkyl or alkoxy each of up to 8 carbon atoms, fluorine, chlorine, bromine or cyano; and R.sub.3 and R.sub.4 are both hydrogen or one is hydrogen and the other is fluorine, chlorine, bromine or cyano, with the proviso that R.sub.3 and R.sub.4 are both hydrogen when X is --CH.sub.2 --CH.sub.2 -- or R.sub.2 is fluorine, chlorine, bromine or cyano, are valuable liquid crystalline compounds.

Abstract: Liquid crystal display elements based on a twisted nematic cell are almost free from interference colors and show only a very little angular dependence of the contrast, if the product of the layer thickness and the optical anisotropy of the liquid crystalline dielectric has a value of 150 to 600 nanometers.

Abstract: Liquid crystalline naphthalene derivatives of the formula ##STR1## wherein ring A is 1,4-phenylene, trans-1,4-cyclohexylene or 1,4-cyclohex-1-enylene and ring system BC is 2,6-naphthylene, 3,4-dihydro-2,6-naphthylene or 1,2,3,4-tetrahydro-2,6-naphthylene, with the proviso that A is not 1,4-phenylene when BC is 2,6-naphthylene; and R.sub.1 and R.sub.2, which are identical or different, are each alkyl of up to 8 C atoms or, when the rings to which they are bonded are aromatic, also can be alkoxy, alkanoyloxy or alkoxycarbonyloxy having up to 8 C atoms in each case; or one of R.sub.1 and R.sub.2 also can be CN, halogen, CF.sub.3 or NO.sub.2 are valuable components for liquid crystalline dielectrics.

Abstract: Diketones of the formula ##STR1## wherein R.sub.1 is alkyl, perfluoroalkyl or alkoxy, each of 1-18 carbon atoms; R.sub.2 is alkyl or perfluoroalkyl, each of 1-12 carbon atoms; and X is 1,4-trans-cyclohexylene, 1,4-phenylene or 4,4'-cyclohexylphenyl are liquid crystalline compounds.

Abstract: Partially hydrogenated oligo-1,4-phenylenes of the formula ##STR1## wherein n is 1 or 2, the rings A and B are identical or different and are trans-4-alkylcyclohexyl or 4-alkylcyclohex-1-enyl, and the alkyl groups in each case are of up to 10 carbon atoms, have valuable liquid crystalline properties.

Abstract: Compounds of the formula ##STR1## wherein R.sub.1 is alkyl of 1-12 C atoms and R.sub.2 is an optionally perfluorinated alkyl, alkoxy or alkanoyloxy group, each of 1-12 C atoms are valuable liquid crystalline components for broadening the mesophase temperature range of liquid crystalline dielectrics having negative dielectric anisotropy.

Abstract: Fluorophenylcyclohexanes of the formula ##STR1## wherein R is alkyl of 1 to 17 carbon atoms and Z is carbonyl or methylene, are valuable components for use in liquid crystal dielectrics.

Abstract: Diketones of the formula ##STR1## wherein R.sub.1 is alkyl, perfluoroalkyl or alkoxy, each of 1-18 carbon atoms; R.sub.2 is alkyl or perfluoroalkyl, each of 1-12 carbon atoms; and X is 1,4-trans-cyclohexylene, 1,4-phenylene or 4,4'-cyclohexylphenyl are liquid crystalline compounds.

Abstract: A liquid-crystalline dielectric having a positive dielectric anisotropy comprises a biphenyl derivative of the formula ##STR1## wherein R.sub.1 is alkyl of 1-4 C atoms or alkoxy of 1-3 C atoms, and a phenylcyclohexane derivative of the formula ##STR2## wherein R.sub.2 is alkyl of 1-4 C atoms, in a weight ratio of 3:1 to 1:3.

Abstract: Carboxylic acid esters of the formula ##STR1## in which one of A or B is 1,4-disubstituted phenyl and the other is trans-1,4-disubstituted cyclohexane and R.sub.1 and R.sub.2 are independently each alkyl of 1-10 carbon atoms have liquid crystalline properties and are valuable components of liquid crystalline dielectrics.