Abstract: Liquid crystalline fluorine-containing pyrimidine compounds have the formula I ##STR1## wherein R.sup.1 and R.sup.2 are H, R, OR or OCOR, and one of them can also be CN or F, or, if A is a covalent bond, also one or both of R.sup.1 and R.sup.2 can be 4-R.sup.4 -phenyl or 4-R-cyclohexyl, wherein R.sup.4 is R, OR, cyano, f or OCOR; wherein R is an alkyl group of 1 to 12 C atoms; R.sup.3 is F or, if one of the radicals R.sup.1 or R.sup.2 is F or 4-fluorophenyl, also H; Z is 1,3-pyrimidin-2,5-diyl; and A is 1,4-phenylene, 1,4-cyclohexylene or a covalent bond.Fluorine-containing pyrimidine compounds are useful components of liquid crystal dielectrics for electro-optical display devices.

Abstract: By suitable choice of the liquid crystal parameters K.sub.3 /K.sub.1 and K.sub.3 /K.sub.2, it becomes possible to achieve a steep electrooptical characteristic line and a maximum contrast with minimum dependence on the viewing angle in electrooptical display elements with a twist angle with a value between 150.degree. and 250.degree..

Abstract: The instant invention relates to compounds of the following formula: ##STR1## wherein R.sup.0 is H or linear alkyl of 1 to 7 C atoms, p is 1 or 2 and n is 0 or 2. The compounds are useful as liquid crystalline compositions in electrooptical display devices.

Abstract: Pyrimidine derivatives of the formula IR.sup.1 --Pry--A.sup.1 --Z.sup.1 --A.sup.2 -[Z.sup.2 --A.sup.3 ].sub.m --R.sup.2 Iin whichR.sup.1 and R.sup.2 each are an alkyl group having 1 to 12 C atoms, in which one or two non-adjacent CH.sub.2 groups can also be replaced by --O--, --CO--, --O--CO--, --CO--O-- or --CH.dbd.CH--, and one of the radicals R.sup.1 and R.sup.2 are H, F, Cl, Br or CN,Pyr is pyrimidine-2,5-diyl,A.sup.1 and A.sup.3 each are 1,4-cyclohexylene, unsubstituted 1,4-phenylene or 1,4-phenylene which is substituted by one or two F and/or Cl atoms and/or CH.sub.3 and /or CN groups,A.sup.2 is 1,4-phenylene which is unsubstituted or substituted by one or two F and/or Cl atoms and/or CH.sub.3 and/or CN groups,Z.sup.1 is --CH.sub.2 CH.sub.2 --, --CH.sub.2 O--, or --OCH.sub.2 --Z.sup.2 is --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, --CH.sub.2 O--, --O--CH.sub.2 -- or a single bond, andm is 0 or 1,are suitable for preparing liquid crystal phases having steep electro-optical characteristic curves.

Abstract: Nitrogen-containing heterocyclic compounds of the formula IR.sup.1 --A.sup.1 --Z.sup.1 --A.sup.2 --[Z.sup.2 --A.sup.3 ].sub.n --R.sup.2whereinR.sup.1 and R.sup.2 in each case independently of one another are an alkyl group with 1-15 C atoms, it also being possible for one or two non-adjacent CH.sub.2 groups to be replaced by O atoms and/or --CO-- groups and/or --O--CO-- groups and/or --CO--O-- groups, and one of the radicals R.sup.1 and R.sup.2 is also H, F, Cl, Br or CN,A.sup.1 is a 1,4-cyclohexylene group, it also being possible for one or two non-adjacent CH.sub.2 groups to be replaced by O atoms, a 1,4-bicyclo-(2,2,2)-octylene group or a 1,3-dithiane-2,5-diyl group,Z.sup.1 and Z.sup.2 in each case independently of one another are --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.2 O-- or a single bond,A.sup.2 and A.sup.

Abstract: Heterocyclic boron compounds of the formula IR.sup.1 --A.sup.1 --Z.sup.1 --A.sup.2 --R.sup.2 (I)can be used as components of liquid-crystal phases. A.sup.1 is --A--, --A.sup.4 --A--, or --A--A.sup.4 -- and A is ##STR1## .

Abstract: Liquid crystal compositions containing at least one compound of the formula IR-Dio-Ph-CN Iwherein R is alkyl of 2 to 5 carbon atoms, Dio is trans-1,3-dioxane-2,5-diyl and Ph is 1,4-phenylene, and at least one compound of each of the following groups A to D:R.sup.1 -Cy-Ph-R.sup.2 AR.sup.3 -Cy-Ph-Ph-R.sup.4 BR.sup.5 -Cy-Ph-CN CR.sup.6 -Cy-COO-Ph-O-R.sup.7 Dand, in addition in a total amount of 10 to 26% by weight at least five compounds of the formula ER.sup.8 -Pyr-Ph-O-R.sup.9 Eor at least one compound of each of the following groups F to K:R.sup.10 -Ph-COO-Ph-R.sup.11 FR.sup.12 -Cy-COO-Ph-Ph-CN GR.sup.13 -Ph-Ph-COO-Ph-Ph-CN HR.sup.14 -Ph-COO-Ph-COO-Ph-R.sup.15 JR.sup.16 -Ph-Ph-COO-PhF-R.sup.17 Kresult in surprisingly steep electrooptical characteristics and surprisingly low viewing-angle dependence of the contrast at simultaneously acceptable threshold voltages for commercially available drivers and multiplex ratios up to 1:100 when used in matrix displays.

Abstract: A liquid crystal phase containing at least one component selected from Group C compounds of the formulae VII to X ##STR1## has particularly advantageous properties.

Abstract: Six-membered ring compounds of the formula I ##STR1## wherein A is a benzene or cyclohexane ring,X.sup.1 to X.sup.6 independently of one another in each case are H, --OR, --COOR, --SR, --SOR, --SO.sub.2 R or, if A is a cyclohexane ring, also --O--COR, andR is in each case an alkyl group which has up to 15 C atoms and in which one or two CH.sub.2 groups can be replaced by O atoms, at least three of the substituents X.sup.1 to X.sup.6 being other than H,can be used as constituents of discotic liquid-crystal phases for liquid-crystal display elements.

Abstract: Organosilicon compounds of the formula IR.sup.1 --A.sup.1 --A.sup.2 --O--C.sub.n H.sub.2n --SiX.sub.a Y.sub.b Z.sub.c Iwherein R.sup.1, A.sup.1, A.sup.2, X, Y, Z, n, a, b and c have the meaning given can be used for producing a homotropic orientation of liquid crystal phases on surfaces.

Abstract: Compounds of the formula IR.sup.1 --A.sup.1 --Z.sup.1 --A.sup.2 --R.sup.2 IwhereinR.sup.1 and R.sup.2 are each an alkyl group having 1-10 C atoms, in which one or two non-adjacent CH.sub.2 groups can also be replaced by O atoms and/or CO groups and/or --OCO-- groups and/or --COO-- groups and/or --CH.dbd.CH-- groups, or are F, Cl, Br, CN or R.sup.3 --A.sup.3 --Z.sup.2 --,A.sup.1 is --A--, --A.sup.4 --A-- or --A--A.sup.4 --,A is a 1,3-dioxane-2,5-diyl or 1,3-dithiane-2,5-diyl group which is monosubstituted or polysubstituted in the 2-position and/or 4-position by alkyl each having 1-10 C atoms and/or in the 5-position by alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy each having 1-5 C atoms, or by F, Cl, Br or CN,A.sup.2, A.sup.3 and A.sup.4 each are 1,3-dithiane-2,5-diyl, piperidine-1,4-diyl, 1,4-bicyclo[2,2,2]octylene, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, 1,4-phenylene, 1,4-phenylene which is substituted by one or two F and/or Cl atoms and/or CH.sub.

Abstract: New bicyclohexylethanes of formula IR1--Cy--Cy--CH2CH2--A--(Cy)n--R2 (I)wherein R1 is alkyl; R2 is alkyl, in which one or two non-adjacent CH.sub.2 groups can be replaced by 0 atoms, or is F, Cl, Br, CN, --COOalkyl or --O--CO--alkyl; or one of the radicals R.sup.1 and R.sup.2 can also be H; A is Cy, or 1,4-phenylene which is unsubstituted or substituted by one or two F and/or Cl atoms and/or CH.sub.3 groups or by a CN group; Cy is 1,4-cyclohexylene and n is 0 or 1; the alkyl groups in each case containing 1-10 C atoms, with the proviso that n is 1 if A is Cy and R2 is CN, can be used as constituents of dielectrics for electrooptical display elements.

Abstract: Cyclohexane derivatives of formula IR.sup.1 --Cy--CH.sub.2 --Q--(Cy).sub.m --O--(CO).sub.n --CH.sub.2 --R.sup.2 IwhereR.sup.1 denotes alkyl with 1 to 12 C atoms in which also one or two non-adjacent CH.sub.2 groups may be replaced by --O--, --CO--, --O--CO--, --CO--O-- or --CH.dbd.CH--,R.sup.2 denotes H, alkyl with 1 to 12 C atoms in which also one or two non-adjacent CH.sub.2 groups may be replaced by --O--, --CO--, --O--CO-- or --CO--O--,Cy denotes trans-1,4-cyclohexyleneQ denotes --CH.sub.2 -- or --O--,m denotes 1 or 2, andn denotes 0 or 1,are suitable as components of liquid-crystalline phases.

Abstract: Dihydroazines of the formula IR.sub.1 --A.sup.1 --Z.sub.1 --A.sub.2 --R.sup.2 Iwherein R.sup.1, R.sup.2, A.sup.1, A.sup.2 and Z.sub.1 have the meanings specified herein may be used as components of liquid crystalline phases.

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: Compounds of the formula IR.sup.1 --A.sup.1 --Z.sup.1 --A.sup.2 --R.sup.2 IwhereinR.sup.1 and R.sup.2 are each H, an alkyl, alkoxy, alkanoyl, alkanoyloxy or alkoxycarbonyl group with in each case 1-10 C atoms, F, Cl, Br, CN or R.sup.3 --A.sup.3 --Z.sup.2 --,A.sup.1 is --A--, --A.sup.4 --A--or --A--A.sup.4 --,A is a 1,3-dioxane-2,5-diyl or a 1,3-dithiane-2,5-diyl group,A.sup.2, A.sup.3 are each a 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl,and A.sup.4 1,3-dithiane-2,5-diyl, piperidine-1,4-diyl or 1,4-bicyclo(2,2,2)octylene group, or a 1,4-phenylene, pyrimidine-2,5-diyl or pyridazine-3,6-diyl group which is unsubstituted or substituted by one or two F and/or Cl atoms and/or CH.sub.3 groups 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.2 O or a single bond andR.sup.3 is H, an alkyl, alkoxy, alkanoyl, alkanoyloxy or alkoxycarbonyl group with in each case 1-10 C atoms, F, Cl, Br or CN, with the proviso that(a) at least one group A.sup.2, A.sup.

Abstract: Nematic liquid crystal phases containing at least one liquid-crystalline compound, which exhibits at least one discotic phase, are suitable for electro-optic display elements with high multiplexing rates.

Abstract: Liquid crystal compounds containing the structural constituent --Py--Th--, wherein Py is a pyridine-2,5-diyl ring and Th is a thiophene-2,4- or -2,5-diyl ring, and in particular pyridylthiophenes of the formula IR.sup.1 --(A.sup.1 --Z.sup.1).sub.m --(A.sup.2 --Z.sup.2).sub.n --Py--Th--(Z.sup.3 --A.sup.3).sub.p --R.sup.2 Iwherein Py and Th have the meanings given, R.sup.1 and R.sup.2 are each an alkyl group with 1-15 C atoms, in which one or two CH.sub.2 groups can also be replaced by O atoms; F, Cl, Br, CN or --O--COR, and one of these radicals can also be H, A.sup.1, A.sup.2 and A.sup.3 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, it being possible for the cyclohexylene group(s) to be substituted in the 1- and/or 4-position by alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy with in each case 1-5 C atoms, F, Cl, Br and/or CN, Z.sup.1, Z.sup.2 and Z.

Abstract: New bicyclohexylethanes of formula IR.sup.1 --Cy--Cy--CH.sub.2 CH.sub.2 --A--(Cy).sub.n --R.sup.2 (I)wherein R.sup.1 is alkyl; R.sup.2 is alkyl, in which one or two non-adjacent CH.sub.2 groups can be replaced by O atoms, or is F, Cl, Br, CN, --COOalkyl or --O--CO-alkyl; or one of the radicals R.sup.1 and R.sup.2 can also be H; A is Cy, or 1,4-phenylene which is unsubstituted or substituted by one or two F and/or Cl atoms and/or CH.sub.3 groups or by a CN group; Cy is 1,4-cyclohexylene and n is 0 or 1; the alkyl groups in each case containing 1-10 C atoms, with the proviso that n is 1 if A is Cy and R.sup.2 is CN,can be used as constituents of dielectrics for electrooptical display elements.