Hoechst Aktiengesellschaft

Merck Patent Gesellschaft MIT Beschrankter Haftung

Gunter Scherowsky

Rainer Wingen

Wolfgang Trapp

Andreas Schliwa

Claus Escher

Dieter Ohlendorf

Hans-Rolf Dubal

Ingrid Muller

Wolfgang Hemmerling

Gerd Heppke

Jurgen Gay

Manel Gunaratne

Lutz Lehmann

Feodor Oestreicher

Gerd Illian

Anke Kaltbeitzel

Detlef Lotzsch

Claas Junghans

Christian Bahr

Yoshio Inoguchi

Michael Sefkow

Uwe Muller

Peter Schreiber

Kirsten Gruneberg

Britta Michalski

Michael Butow

Optically active 1,3-dioxolane derivatives which carry a mesogenic radical in the 4-position and have the general formula (I) ##STR1## are suitable for use as doping agents in liquid-crystal mixtures--in particular ferroelectric liquid-crystal mixtures. The symbols in the general formula have the following meanings:

Optically active 1,3-dioxolane derivatives carrying a mesogenic radical

A ferroelectric, liquid-crystalline polymer is composed of repeating units of the formula (I) ##STR1## in which Y=H, CH.sub.3 or F,

Ferroelectric liquid-crystalline polymers, a process for their

A ferroelectric, liquid-crystalline polymer is composed of repeating units of the formula I ##STR1## in which Y=H or CH.sub.3

Optically active oxirane derivatives containing a mesogenic molecular unit are suitable as dopes in liquid-crystal mixtures. They give liquid-crystalline ferroelectric phases having short response times and electroclinic phases having large electroclinic coefficients. A further advantage is that they induce a helix of very small pitch, so that they are also suitable for helix compensation in LC mixtures.

Optically active oxirane derivatives, and their use as dopes in

Azetidinones of the formula I ##STR1## in which, for example, R.sup.1 is an alkyl or alkenyl radical, R.sup.2 and R.sup.3 are hydrogen or an alkyl or alkenyl radical, Z is hydrogen or (pseudo)halogen, A.sup.1, A.sup.2 and A.sup.3 are a ring system, and M is a spacer group, can be added to liquid-crystal mixtures. Even when admixed in small amounts, they cause considerable twist in the cholesteric and smectic C* phase, which can compensate the pitch of another dope or produce a short S.sub.C * pitch.

Chiral azetidinone derivatives, and their use as dopes in liquid-crystal

Chiral oxazolidinones of the formula (I) or (II) ##STR1## in which R.sup.1 is, for example, a straight-chain or branched alkyl radical having 1 to 16 carbon atoms or

Oxazolidinone derivatives, and the use thereof as dopes in

Ferroelectric, liquid-crystalline polymers, a process for their

Ferroelectric, liquid-crystaline polymers contain repeating units of the formula (I) ##STR1## in which the symbols have the following meanings: B=a group having at least one chiral center, of the formula ##STR2## in which R.sup.6, R.sup.7 and R.sup.8 are identical or different and are H, CH.sub.3, OCH.sub.3, F, Cl or Br, and at least one of the groups R.sup.6, R.sup.7 and R.sup.8 must be H and X=H, F, Cl or Br and R.sup.9 =H or C.sub.1 -C.sub.10 -alkyl,

Chiral substituted tartarimides, a process for their preparation and their use as doping agents in liquid-crystal mixtures. The new chiral N-substituted tartarimides which are esterified on both of the OH groups (pyrrolidinediones) are characterized by the general formula (I) ##STR1## in which the symbols have the following meaning: R.sup.2 denotes linear or branched (C.sub.1 -C.sub.16)-alkyl, it being possible for one or two non-adjacent CH.sub.2 groups to be replaced by O or S, or, if n1=1, also denotes F, Cl, Br or CN,

Chiral substituted tartarimides

Optically active oxirane-2-carboxylic acid esters with a mesogenic molecular component suitable as dopants in liquid-crystal mixtures. They result in liquid-crystalline ferroelectric phases with short switching times and in electroclinic phases with large electroclinic coefficients. A further advantage lies in the fact that they induce a helix with a very small pitch so that they are also suitable for helix compensation in LC mixtures.

Use of optically active oxirane-2-carboxylic acid esters as dopants in

The new compounds produced from a molecular structural element with two chirality centers and at least one mesogenic structural element are defined by the general formula (I) ##STR1## in which the symbols have the following meaning: Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4 = in any two cases (a) hydroxy and MC--CO--O or, independently of each other, MC--CO--O and (b), independently of each other (C.sub.1 -C.sub.10)alkoxy, MC denoting the molecular radical of a mesogenic carboxylic acid after splitting off a COOH group, and it being possible for Y.sup.2 and Y.sup.3, in the case of (C.sub.1 -C.sub.10)alkoxy, also to be jointly part of a dioxolane ring, or Y.sup.1 and Y.sup.4 jointly = 0 as part of a tetrahydrofuran ring, and Y.sup.2 and Y.sup.3 = hydroxy and MC--CO--O or, independently of each other, MC--CO--O. Said esters preferably find application as dopants in twistable liquid crystal phases in which they produce temperature compensation and twisting.

Chiral reaction products produced from mesogenic molecular structural

The new compounds produced from a molecular structural element with two chirality centers and at least one mesogenic structural element are defined by the general formula (I) ##STR1## in which the symbols have the following meaning: Y.sup.1 =H, (C.sub.1 -C.sub.10)alkyl, MC--CH.sub.2 or MC--CO, MC denoting the molecular radical of a mesogenic carboxylic acid after splitting off a COOH group,

The novel compounds are chiral esters of .alpha.-substituted phenylalkanoic acids and mesogenic hydroxy compounds, the symbols in the general formula (I) ##STR1## being defined as follows: MO=molecular radical of a mesogenic hydroxy compound MOH after removal of one H, the radical MO being expressed by the general formula (II)

Chiral esters of .alpha.-substituted phenylalkanoic acids and mesogenic

The new esters derived from a chiral compound containing two OH groups and at least one mesogenic carboxylic acid which have the general formula (I) ##STR1## in which X.sup.1 =O--H or O--CO--(C.sub.1 to C.sub.12)alkyl and X.sup.2 =O--MC or X.sup.1 and X.sup.2 denote O-MC independently of each other, where MC is the molecular radical of a mesogenic monocarboxylic acid after splitting off an OH group. The esters or esters substituted in the aromatic part of the phenolic part preferably find application as an admixture intwistable liquid crystal phases in which they produce a temperature compensation and a high degree of twisting.

Chiral phenolic esters of mesogenic carboxylic acids and their use as

New anthraquinone dyestuffs of the general formula I ##STR1## wherein Hal is a halogen atom and the two radicals R are each H or NH.sub.2 and the alkyl group has 1-8 C atoms, exhibit a high order parameter and are suitable for use as components of liquid-crystal dielectrics.

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Gunter Scherowsky