Abstract: Ferroelectric liquid crystal mixtures containing compounds of the formula (I): ##STR1## wherein R.sup.1 is, for example, a straight-chain or branched alkyl radical having 1 to 22 carbon atoms, in which one --CH.sub.2 -- group may be replaced by --O-- or --CO--O--.

Abstract: Bifunctional compounds of the formula (I), ##STR1## in which: ##STR2## are naphthalene-2,6-diyl or ##STR3## is naphthalene-2,6-diyl or ##STR4## U, X, Y and Z are --CH.dbd., --CF.dbd. and --N.dbd., with the proviso that --CF.dbd. and --N.dbd. may each only be represented at most twice per six-membered ring, and that --CF.dbd. and --N.dbd. may not at the same time be represented twice in a six-membered ring;Hal is Cl, Br or I; or H, if X and/or Y are --CF.dbd.R.sup.3 is CH.sub.3 or OCH.sub.3l is 0 or 1m and n are 0, 1, 2 or 3.The compounds of the formula I are useful intermediates for the preparation of liquid-crystalline mixtures.

Abstract: Compounds of the formula (I)R.sup.1 --(A.sup.1).sub.a (--M.sup.1).sub.b --(--A.sup.2).sub.c (--M.sup.2).sub.d (--A.sup.3).sub.e (--M.sup.3).sub.f (--A.sup.4).sub.g --H(I)in which the symbols and indices have the following meanings:R.sup.1 is B or a straight-chain or branched alkyl radical having 1 to 22 carbon atoms (with or without an asymmetrical carbon atom) in which, in addition, it is possible for one or two non-adjacent --CH.sub.2 -- groups to be replaced by --O--, --S--, --CO--, --CO--O--, --O--CO--, --CO--S--, --S--CO--, --O--CO--O--, --CH.dbd.CH--, --C.tbd.C--, .DELTA. or --Si(CH.sub.3).sub.2 --, and in which, in addition, one or more hydrogen atoms of the alkyl radical may be substituted by F, Cl, Br or CN, or is a chiral group, for example an epoxide, a dioxolane or a cyclic lactone,--(A.sup.1).sub.a (--M.sup.1).sub.b --(--A.sup.2).sub.c (--M.sup.2).sub.d (--A.sup.3).sub.e (--M.sup.3).sub.f (--A.sup.4).sub.

Abstract: Thiadiazole derivatives of the formula (I)X-B-A.sup.1 -(M.sup.1 -A.sup.2 -).sub.m (M.sup.2 -A.sup.3).sub.n -R.sup.1(I )in which the symbols and indices have the following meanings:X is Cl, Br or I;B is 1,3,4-thiadiazole-2,5-diyl;A.sup.1, A.sup.2 and A.sup.3 are identical or different and are substituted or unsubstituted 1,4-phenylene, pyrazine-2,5-diyl, pyridazine-3,6-diyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl, trans-1,4-cyclohexylene, 1,3,4-thiadiazole-2,5-diyl, 1,3-dioxane-2,5-diyl, 1,3-dithiane-2,5-diyl, 1,3-thiazole-2,4-diyl, 1,3-thiazole-2,5-diyl, thiophene-2,4-diyl, thiophene-2,5-diyl, piperazine-1,4-diyl, piperazine-2,5-diyl, naphthalene-2,6-diyl, bicyclo?2.2.2!octane-1,4-diyl, or 1,3-dioxaborinane-2,5-diyl;M.sup.1 and M.sup.2 are identical or different and are --CO--O--, --O--CO--, --O--CO--O--, --O--CS--O--, --CH.sub.2 --O--, --O--CH.sub.2 --, --CH.dbd.CH--, --C.tbd.C-- or a single bond;R.sup.

Abstract: Disclosed are derivatives of fluoroalkylethynyl- and difluoroalkylethynylbenzenes of the formula (I) herein. These compounds exhibit useful properties as liquid crystal compounds and are useful in nematic liquid crystal mixtures.

Abstract: A 3,4,5-trifluorobenzene derivatives of formula (I): ##STR1## in which R.sup.1 is a straight-chain or branched alkyl having 1 to 15 carbon atoms in which one or two nonadjacent --CH.sub.2 --groups are optionally replaced by --O--, --CH.dbd.CH--, --C.tbd.C--, cyclopropane-1,2-diyl or --Si(CH.sub.3).sub.2 --, and in which one or more H atoms in the alkyl radical may be substituted by F; A.sup.1, A.sup.2 and A.sup.3 are identical or different 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl in which one or two H atoms are, optionally, replaced by F, trans-1,4-cyclohexylene, 1,3-dioxane-2,5-diyl or naphthalene-2,6-diyl,M.sup.1 and M.sup.2 are identical or different --CH.sub.2 CH.sub.2 --,--CH.dbd.CH--,--C.tbd.C--,--CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 --, --CH.sub.2 --O--,--O--CH.sub.2 --,--CO--O-- or--O--CO; X is --CH.sub.2 --O--,--OCH.sub.2 -- or --O--CO--; andk, l, m, n, o and p are zero or one provided that the sum k+m+o is greater than zero.

Abstract: Novel oxiranylmethyl ethers can advantageously be employed in liquid-crystal mixtures since they have high spontaneous-polarization values and features in their molecular structure which make them miscible with other components of liquid-crystal systems.

Abstract: Compounds of formula I ##STR1## in which R.sup.1 and R.sup.2 are, for example, an alkyl chain,A is a mesogenic group, andM is a spacer group,are highly suitable as components of liquid-crystal mixtures.

Abstract: 2-Fluoropyridines, processes for their preparation and their use in ferroelectric liquid crystal mixturesA 2-fluoropyridine of the formula (I) ##STR1## in which the symbols have the following meaning: R.sup.1, R.sup.2, independently of one another, are, for example, H or straight-chain or branched alkyl, A.sup.1, A.sup.2, A.sup.3, A.sup.4, identical or different, are, for example, 1-phenylene, pyrazine-2,5-diyl or trans-1,4-cyclohexylene, M.sup.1, M.sup.2, M.sup.3, M.sup.4, identical or different, are, for example, --O-- or --CO--O--, R.sup.3, R.sup.4, R.sup.6, R.sup.7, independently of one another, are, for example, H or straight-chain or branched alkyl, M.sup.5 is, for example, --O--CO-- or a single bond, k, l, m, n, o, p, q, r are zero or one, with the proviso that the sum of k+m+p+r is less than 4 and greater than zero, can advantageously be used as a component in ferroelectric liquid crystal mixtures.

Abstract: 3-Chloropyridines, process for their preparation, and their use in liquid-crystal mixturesA 3-chloropyridine of the formula (I) ##STR1## in which the symbols have the following meaning: R.sup.1 and R.sup.2, independently of one another, are, for example, H or straight-chain or branched alkyl, A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are identical or different and are, for example, 1,4-phenylene, pyrazine-2,5-diyl or trans-1,4-cyclohexylene, M.sup.1, M.sup.2, M.sup.3 and M.sup.4 are identical or different and are, for example, --O-- or --CO--O--, R.sup.3, R.sup.4, R.sup.6 and R.sup.7, independently of one another are, for example, H or straight-chain or branched alkyl, M.sup.5 is, for example, --O--CO-- or a single bond, k, l, m, n, o, p, q and r are zero or one, with the proviso that the sum k+m+p+r is less than 4 and greater than zero, can advantageously be employed as a component in ferroelectric liquid-crystal mixtures.

Abstract: An aromatic compound of the formula (I)R.sup.1 (--A.sup.1).sub.a (--M.sup.1).sub.b (--A.sup.2).sub.c (--M.sup.2).sub.d --B(--M.sup.3).sub.c (--A.sup.3).sub.f (--M.sup.4).sub.g (--A.sup.4).sub.h --R.sub.2 (I)in whichB is one of the two following aromatic groups: ##STR1## Q.sup.1, Q.sup.2, Q.sup.3 and Q.sup.4 are identical or different and are CH.sub.2, CF.sub.2, N--R.sup.3, S, O or C.dbd.O;P.sup.1, P.sup.2 and P.sup.3 are identical or different and are C--H, C--F or N; andthe remaining symbols and indicies define mesogenic radicals, The compounds are suitable as components of liquid-crystalline mixtures.

Abstract: 2-Fluoropyrazines, process for their preparation, and their use in liquid-crystalline mixturesA 2-fluoropyrazine of the formula (I) ##STR1## in which the symbols have the following meanings: R.sup.1 and R.sup.2, independently of one another, are, for example, H or straight-chain or branched alkyl,A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are identical or different and are, for example, 1,4-phenylene orM.sup.1, M.sup.2, M.sup.3 and M.sup.4 are identical or different and are, for example, --0-- or --CO--O--,R.sup.3, R.sup.4, R.sup.6 and R.sup.7, independently of one another, are, for example, H or straight-chain or branched alkyl,M.sup.5 is, for example, --O--CO-- or a single bond,k, l, m, n, o, p, q and r are zero or one, with the condition that the sum of k+m+p+r is less than 4 and greater than zero,can advantageously be employed as a component in liquid-crystal mixtures.

Abstract: A process for preparing polycyclic aromatic compounds by cross-coupling aromatic boronic acids with aromatic halogen compounds or perfluoroalkylsulfonates in the presence of metallic palladium, if desired applied to a support material, as catalyst, wherein the coupling is carried out in the presence of a ligand and a base. The process of the invention allows the yield of polycyclic aromatic compounds to be significantly increased in comparison with processes not using a ligand and thus allows a yield optimum for the Pd(0)-catalyzed cross-coupling of aromatic boronic acids with aromatic halogen compounds to be achieved.

Abstract: Azaaromatic compounds of the formula I ##STR1## in which R.sup.1 and R.sup.2 are, for example, alkyl radicals,M is, for example, --O--, --COO-- or --O--CO--O--,A is an aromatic or heteroaromatic ring,V, X, Y and Z are CH, CF or N,a,b,c,d,m and n are 0 or 1, where m+n is 0 or 1 and a+d is 0 or 1.The compounds of the formula I are suitable as components of liquid-crystal mixtures.

Abstract: Meta-substituted aromatic compounds having six-membered rings, for use in liquid-crystal mixturesCompounds of the formula I ##STR1## in which X is CH, CF or N,R.sup.2 is, for example, an alkyl, ether or ester group, which may also contain a chiral center, andR.sup.1 (--A.sup.1).sub.a (--M.sup.1).sub.b (--A.sup.2).sub.c (--M.sup.2) .sub.d (--A.sub.3).sub.e (--M.sub.3).sub.f is a mesogenic radical,can advantageously be used as components of liquid-crystal mixtures, in particular ferroelectric liquid-crystal mixtures.The substances of the formula I have a particularly favorable effect on the optical switching angle and the critical pulse area of the mixtures.

Abstract: A 3-fluoropyridine of the formula (I) ##STR1## in which the symbols have the following meanings: R.sup.1 and R.sup.2, independently of one another, are, for example, H or straight-chain or branched alkyl, A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are identical or different and are, for example, 1,4-phenylene, pyrazine-2,5-diyl or trans-1,4-cyclohexylene, M.sup.1, M.sup.2, M.sup.3 and M.sup.4 are identical or different and are, for example, --O-- or --CO--O--, R.sup.3, R.sup.4, R.sup.6 and R.sup.7, independently of one another are, for example, H or straight-chain or branched alkyl, M.sup.5 is for example, --O--CO-- or a single bond, k, l, m, n, o, p, q and r are zero or one, with the proviso that the sum k+m+p+r is less than 4 and greater than zero, can advantageously be employed as a component in ferroelectric liquid-crystal mixtures.

Abstract: Process for preparing 2,5-dibromopyrimidine A process for preparing 2,5-dibromopyrimidine comprises reacting 5-bromo-2-chloropyrimidine with a solution of hydrogen bromide in a non-aqueous acid at a temperature of between 0.degree. and 120.degree. C.The process can be carried out at low cost and gives high yields.

Abstract: Dry developable top surface imageable photoresist compositions which comprise, in admixture, a film-forming aromatic polymer resin activated to electrophilic substitution, an acid catalyzable agent capable of being inserted into the aromatic polymer resin, and a radiation degradable acid generating compound and processes for generating positive tone resist images on substrates therewith.

Abstract: The present invention relates to a process for negative tone imaging of photoresist to improve resolution of lithographic patterns.