DE19933175B4 - Sulfur sulfenate derivatives and use for a liquid crystalline medium - Google Patents

Abstract

worin
R¹ H, einen unsubstituierten, einen einfach durch CN oder CF₃ oder einen mindestens einfach durch Halogen substituierten Alkylrest mit 1–12 C-Atomen oder Alkenylrest mit 2–12 C-Atomen, wobei in diesen Resten auch eine oder mehrere nicht benachbarte CH₂-Gruppen jeweils unabhängig voneinander durch -O-, -S-, -CO-, -CH=CH-,

-CO-O-, -O-CO- oder -O-CO-O- ersetzt sein können,
A¹ und A²
a) trans-Cyclohexan-1,4-diylrest, worin auch eine oder mehrere nicht benachbarte CH₂-Gruppen durch -O- und/oder -S- ersetzt sein können,
b) 1,4-Phenylenrest, worin auch eine oder zwei CH-Gruppen durch N ersetzt sein können,
c) Rest aus der Gruppe 1,4-Bicyclo(2,2,2)-octylen, Piperidin-1,4-diyl, Naphthalin-2,6-diyl, Decahydronaphthalin-2,6-diyl und 1,2,3,4-Tetrahydronaphthalin-2,6-diyl,
wobei die Reste a) und b) durch CN, Cl oder F substituiert sein können, und
mindestens einer der Reste A¹/A² in den Formeln ein Naphthalin-2,6-diyl, Decahydronaphthalin-2,6-diyl oder 1,2,3,4-Tetrahydronaphthalin-2,6-diyl
bedeutet,
L H oder F,
Z¹ und Z² jeweils...Sulfur pentafluoride derivatives of the formula I or IA

wherein
R ¹ H, an unsubstituted, a simple by CN or CF ₃ or at least one halogen-substituted alkyl radical having 1-12 C-atoms or alkenyl radical having 2-12 C-atoms, wherein in these radicals also one or more non-adjacent CH ₂ groups each independently of one another by -O-, -S-, -CO-, -CH = CH-,

-CO-O-, -O-CO- or -O-CO-O- may be replaced,
A ¹ and A ²
a) trans-cyclohexane-1,4-diyl radical, in which also one or more non-adjacent CH ₂ groups may be replaced by -O- and / or -S-,
b) 1,4-phenylene radical, in which also one or two CH groups can be replaced by N,
c) radical from the group consisting of 1,4-bicyclo (2,2,2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl and 1,2,3 , 4-tetrahydronaphthalene-2,6-diyl,
where the radicals a) and b) may be substituted by CN, Cl or F, and
at least one of the radicals A ¹ / A ² in the formulas a naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl
means
L H or F,
Z ¹ and Z ² each ...

Description

worin
R¹ H, einen unsubstituierten, einen einfach durch CN oder CF₃ oder einen mindestens einfach durch Halogen substituierten Alkylrest mit 1–12 C-Atomen oder Alkenylrest mit 2–12 C-Atomen, wobei in diesen Resten auch eine oder mehrere nicht benachbarte CH₂-Gruppen jeweils unabhängig voneinander durch -O-, -S-, -CO-, -CH=CH-,

-CO-C-, -C-CO- oder -O-CO-O- ersetzt sein können,
A¹ und A²

• a) trans-Cyclohexan-1,4-diylrest, worin auch eine oder mehrere nicht benachbarte CH₂-Gruppen durch -O- und/oder -S- ersetzt sein können,
• b) 1,4-Phenylenrest, worin auch eine oder zwei CH-Gruppen durch N ersetzt sein können,
• c) Rest aus der Gruppe 1,4-Bicyclo(2,2,2)-octylen, Piperidin-1,4-diyl, Naphthalin-2,6-diyl, Decahydronaphthalin-2,6-diyl und 1,2,3,4-Tetrahydronaphthalin-2,6-diyl,

wobei die Reste a), b) durch CN, Cl oder F substituiert sein können, und mindestens einer der Reste A¹/A² in den Formeln ein Naphthalin-2,6-diyl, Decahydronaphthalin-2,6-diyl oder 1,2,3,4-Tetrahydronaphthalin-2,6-diyl bedeutet,
L H oder F
Z¹ und Z² jeweils unabhängig voneinander -CO-O-, -O-CO-, -CH₂O-, -O-, -O-CH₂, -CH₂CH₂-, -CF₂CF₂-, -CH=CH-, -C≡C- oder eine Einfachbindung,
und worin
für Formel I
n und m 0,1 oder 2, und
n+m 1 oder 2,
bzw.
für Formel IA
m 1 oder 2
bedeutet.The invention relates to novel sulfur pentafluoride derivatives of the formula I.

wherein
R ¹ H, an unsubstituted, a simple by CN or CF ₃ or at least one halogen-substituted alkyl radical having 1-12 C-atoms or alkenyl radical having 2-12 C-atoms, wherein in these radicals also one or more non-adjacent CH ₂ groups each independently of one another by -O-, -S-, -CO-, -CH = CH-,

-CO-C-, -C-CO- or -O-CO-O- may be replaced,
A ¹ and A ²

• a) trans-cyclohexane-1,4-diyl radical, in which also one or more non-adjacent CH ₂ groups can be replaced by -O- and / or -S-,
• b) 1,4-phenylene radical, in which also one or two CH groups can be replaced by N,
• c) radical from the group consisting of 1,4-bicyclo (2,2,2) -octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl and 1,2,3 , 4-tetrahydronaphthalene-2,6-diyl,

where the radicals a), b) may be substituted by CN, Cl or F, and at least one of the radicals A ¹ / A ² in the formulas a naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1, 2,3,4-tetrahydronaphthalene-2,6-diyl,
L H or F
Z ¹ and Z ^{2 are} each independently of one another -CO-O-, -O-CO-, -CH ₂ O-, -O-, -O-CH ₂ , -CH ₂ CH ₂ -, -CF ₂ CF ₂ -, -CH = CH-, -C≡C- or a single bond,
and in which
for formula I
n and m are 0,1 or 2, and
n + m 1 or 2,
respectively.
for formula IA
m 1 or 2
means.

The The invention further relates to the use of these compounds as components of liquid crystalline Media. liquid-crystal and electro-optical display elements comprising the liquid-crystalline Contain media are disclosed.

The compounds of the formula I can be used as components of liquid-crystalline media, in particular for displays based on the principle of the twisted cell, the guest-host effect, the effect of deformation of upright phases DAP or ECB, Electrically controlled birefringence or the effect of the dynamic Scattering based. The substances used so far for this purpose always have certain Disadvantages, for example, too low stability against the action of heat, light or electric fields, unfavorable elastic and / or dielectric properties.

Similar phenyl-sulfur pentafluoride derivatives are known, for example DE 37 21 268 ,

Of the Invention was based on the object new stable liquid crystalline or to find mesogenic compounds which are components of liquid-crystalline Media, especially for TFT and STN displays are suitable.

It has now been found that the Compounds of the formula I excellently as components of liquid crystalline Media are suitable. With their help can be stable liquid crystalline Media, especially suitable for TFT or STN displays, receive. The new connections are mainly characterized by a high thermal stability out for that a high "holding ratio "advantageous is and show favorable values at comparatively low rotational viscosity the clearing points. The compounds of formula I have a strong positive dielectric Anisotropy with high optical anisotropy on. she are also characterized by very good solubility in different host mixtures.

With the provision of compounds of formula I is quite general the range of liquid crystalline Substances that differ from different application-technical points of view for the production of liquid crystalline Mixtures are suitable, considerably widened.

The Compounds of the formula I have a wide range of applications. Dependent on from the choice of substituents, these compounds can be considered as Base materials serve, from which liquid-crystalline media for the predominant Part are composed; it can but also compounds of the formula I liquid-crystalline base materials be added from other classes of compounds, for example the dielectric and / or optical anisotropy of such a dielectric to influence and / or its threshold voltage and / or its viscosity to optimize.

The Compounds of the formula I are colorless in the pure state and form liquid crystalline Mesophases in a for the electro-optical use favorable located temperature range. Chemical, thermal and against light they are stable. Of the formula I, all isotopes of in comprises the compounds of the formula I occurring elements.

object The invention thus relates to the compounds of the formula I and the Use of these compounds as components of liquid-crystalline Media. Also disclosed are liquid-crystalline media a content of at least one compound of the formula I and liquid-crystal display elements, in particular electro-optical display elements, such media contain.

Above and below, A ¹ , A ¹ , A ² , Z ¹ , Z ² , L, m and n have the indicated meaning, unless expressly stated otherwise.

Of the In the following, Cyc means a 1,4-cyclohexylene radical, Che is a 1,4-Ocyclohexenylenrest, Dio a 1,3-dioxane-2,5-diyl, Dit one 1,3-dithian-2,5-diyl, Phe a 1,4-phenylene, Pyd a Pyridine-2,5-diyl, Pyr is pyrimidine-2,5-diyl and Bco is one Bicyclo (2,2,2) -octylene radical, where Cyc and / or Phe are unsubstituted or may be mono- or polysubstituted by Cl, F or CN.

worin R¹, A¹, Z¹, m und L die oben angegebene Bedeutung aufweisen.Formula I comprises the preferred compounds IA and IB:

wherein R ¹ , A ¹ , Z ¹ , m and L have the meaning given above.

formula IA is particularly preferred.

In the compounds of the formulas IA and IB, Z ^{1 is} preferably a single bond or -COO-, in particular a single bond. A ¹ in these compounds is preferably Phe and m is preferably 0 or 1.

R ¹ in the compounds of the formula IA is preferably straight-chain alkyl or alkoxy having 1 to 10 C atoms or alkenyl or alkenyloxy having 2 to 10 C atoms. Most preferably, R ^{1 is} alkenyl or alkenyloxy having 2 to 7 carbon atoms. The preferred meaning of m is 0 or 1, n is preferably 0.

A ¹ and A ² independently of one another are preferably Phe, Cyc, Che, Pyd, Pyr or Dio. The compounds of the formula I preferably contain no more than one of the radicals Bco, Pyd, Pyr, Dio or Dit.

If the ring A ¹ is present several times, the two rings can have the same or different meanings. The same applies to the bridge Z ¹ as well as to all other groups which occur several times in the compounds of the formula I.

Preference is also given to compounds of the formula I and of all subformulae in which A ¹ denotes mono- or disubstituted by F or CN-substituted 1,4-phenylene.

Z¹ und Z² bedeuten unabhängig voneinander bevorzugt -CH₂CH₂-, -CH=CH-, -C≡C- oder eine Einfachbindung, insbesondere bevorzugt eine Einfachbindung oder -C≡C-. Ganz besonders bevorzugt weist Z¹ die Bedeutung einer Einfachbindung auf.Preferably, A ¹ and A ²

Z ¹ and Z ² independently of one another are preferably -CH ₂ CH ₂ -, -CH = CH-, -C≡C- or a single bond, particularly preferably a single bond or -C≡C-. Most preferably, Z ^{1 has} the meaning of a single bond.

Compounds of the formula I are preferred, which are characterized in that R ^{1 is} straight-chain alkyl or alkoxy having 1 to 10 carbon atoms or alkenyl having 2 to 10 carbon atoms and Z ^{1 has} the meaning of a single bond.

If R ¹ in the formulas above and below denotes an alkyl radical and / or an alkoxy radical, this may be straight-chain or branched. Preferably, it is straight-chain, has 2, 3, 4, 5, 6 or 7 C-Ato and therefore preferably denotes ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy or heptyloxy, furthermore methyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, Octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy or tetradecyloxy.

oxaalkyl preferably denotes straight-chain 2-oxapropyl (= methoxymethyl), 2 - (= ethoxymethyl) or 3-oxabutyl (= 2-methoxyethyl), 2-, 3- or 4-oxapentyl, 2-, 3-, 4- or 5-oxahexyl, 2-, 3-, 4-, 5- or 6-oxaheptyl, 2-, 3-, 4-, 5-, 6- or 7-oxo-octyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-oxanonyl, 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-oxadecyl.

If R ^{1 is} an alkenyl radical, this may be straight-chain or branched. It is preferably straight-chain and has 2 to 10 C atoms. It therefore means especially vinyl, prop-1, or prop-2-enyl, but-1, 2- or but-3-enyl, pent-1, 2-, 3- or pent-4-enyl, hex 1-, 2-, 3-, 4- or hex-5-enyl, hept-1, 2-, 3-, 4-, 5- or hept-6-enyl, Oct-1, 2-, 3-, 4-, 5-, 6- or oct-7-enyl, non-1-, 2-, 3-, 4-, 5-, 6-, 7- or non-8-enyl, Dec-1 -, 2-, 3-, 4-, 5-, 6-, 7-, 8- or dec-9-enyl.

R ¹ particularly preferably denotes an alkenyl radical from the following group:

If R ^{1 is} an alkenyloxy radical, this may be straight-chain or branched. It is preferably straight-chain and has 2 to 10 C atoms. It particularly preferably represents a radical of the following group:

If R ^{1 is} an alkyl radical in which one CH ₂ group is replaced by -O- and one by -CO-, these are preferably adjacent. Thus, these include an acyloxy group -CO-O- or an oxycarbonyl group -O-CO-. Preferably, these are straight-chain and have 2 to 6 carbon atoms.

she therefore especially acetyloxy, propionyloxy, butyryloxy, Pentanoyloxy, hexanoyloxy, acetyloxymethyl, propionyloxymethyl, Butyryloxymethyl, pentanoyloxymethyl, 2-acetyloxyethyl, 2-propionyloxyethyl, 2-butyryloxyethyl, 3-acetyloxypropyl, 3-propionyloxypropyl, 4-acetyloxybutyl, Methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, Pentoxycarbonyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, propoxycarbonylmethyl, Butoxycarbonylmethyl, 2- (methoxycarbonyl) ethyl, 2- (ethoxycarbonyl) ethyl, 2- (propoxycarbonyl) ethyl, 3- (methoxycarbonyl) propyl, 3- (ethoxycarbonyl) propyl, 4- (methoxycarbonyl) butyl.

If R ^{1 is} an alkyl radical in which a CH ₂ group is replaced by unsubstituted or substituted -CH = CH- and an adjacent CH ₂ group by CO or CO-O or O-CO-, it may be straight-chain or branched be. Preferably, it is straight-chain and has 4 to 13 carbon atoms. It therefore particularly means acryloyloxymethyl, 2-acryloyloxyethyl, 3-acryloyloxypropyl, 4-acryloyloxybutyl 5-acryloyloxypentyl, 6-acryloyloxyhexyl, 7-acryloyloxyheptyl, 8-acryloyloxyoctyl, 9-acryloyloxynonyl, 10-acryloyloxydecyl, methacryloxy-oxymethyl, 2-methacryloyloxyethyl, 3-methacryloyloxypropyl, 4-methacryloyloxybutyl, 5-methacryloyloxypentyl, 6-methacryloyloxyhexyl, 7-methacryloyloxyheptyl, 8-methacryloyloxyoctyl, 9-methacryloyloxynonyl.

If R ^{1 is} an alkyl or alkenyl radical which is monosubstituted by CN or CF ₃ , this is Preferably, the radical is straight-chain and the substitution by CN or CF ₃ in the ω position.

If R ^{1 is} an alkyl or alkenyl radical which is at least monosubstituted by halogen, this radical is preferably straight-chain and halogen is preferably F or Cl. In the case of multiple substitution, halogen is preferably F. The resulting radicals also include perfluorinated radicals. For single substitution, the fluoro or chloro substituent may be in any position, but preferably in the ω position.

Occasionally, compounds of the formula I having branched wing group R ¹ may be of importance for better solubility in the usual liquid-crystalline base materials, but especially as chiral dopants, if they are optically active. Smectic compounds of this type are useful as components of ferroelectric materials.

Branched groups of this type usually contain no more than one chain branch. Preferred branched radicals R ¹ are isopropyl, 2-butyl (= 1-methylpropyl), isobutyl (= 2-methylpropyl), 2-methylbutyl, isopentyl (= 3-methylbutyl), 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl, 2-propylpentyl, isopropoxy, 2-methylpropoxy, 2-methylbutoxy, 3-methylbutoxy, 2-methylpentyloxy, 3-methylpentyloxy, 2-ethylhexyloxy, 1-methylhexyloxy, 1-methylheptyloxy.

formula I included both the racemates of these compounds and the optical antipodes as well as their mixtures.

Under these compounds of the formula I and the sub-formulas are those preferably, in which at least one of the radicals contained therein has one of the preferred meanings given.

In the compounds of the formula I, those stereoisomers are preferred, in which the rings cyc and piperidine are trans-1,4-disubstituted. Those of the above formulas containing one or more Groups Pyd, Pyr and / or Dio contain, each enclosing the two 2,5-position isomers.

The Compounds of the formula I are prepared by methods known per se as described in the literature (e.g., in the standard works as Houben-Weyl, Methods of Organic Chemistry, Georg-Thieme-Verlag, Stuttgart) are described under reaction conditions, the for the said reactions are known and suitable.

there One can make use of known per se, not mentioned here variants.

The 4-substituted phenyl-sulfur pentafluorides used as starting compounds can e.g. according to the literature (W.A. Sheppard, J. Am. Chem. Soc., 84, 3064, 1962) to be obtained.

there starting from di (p-nitrophenyl) disulfide, from which by reacting obtained with silver difluoride p-Nitrophenylschwefelpentafluorid, the again as the starting compound of many 4-substituted phenylsulfur pentafluorides can serve.

The Starting materials can if desired also be formed in situ, such that they are removed from the reaction mixture not isolated, but immediately further to the compounds of the formula I implements.

Schema 2

in = 1 oder 2 Schema 3

m = 1 oder 2The compounds according to the invention can be prepared, for example, according to the following reaction schemes: Scheme 1

Scheme 2

in = 1 or 2 Scheme 3

m = 1 or 2

ester of the formula I can also by esterification of corresponding carboxylic acids (or their reactive derivatives) with alcohols or phenols (or their reactive derivatives) or by the DCC method (DCC = dicyclohexylcarbodiimide) can be obtained.

The corresponding carboxylic acids and alcohols or phenols are known or can be prepared in analogy to known Process are produced.

When reactive Derivatives of said carboxylic acids In particular, the acid halides are suitable, especially the chlorides and bromides, furthermore the anhydrides, azides or esters, in particular alkyl esters having 1-4 C atoms in the alkyl group.

When reactive Derivatives of the alcohols or phenols mentioned come in particular the corresponding metal alcoholates or phenolates, preferably an alkali metal such as Na or K, into consideration.

The Esterification becomes advantageous in the presence of an inert solvent carried out. Particularly suitable are, in particular, ethers, such as diethyl ether, di-n-butyl ether, THF, Dioxane or anisole, ketones such as acetone, butanone or cyclohexanone, Amides such as DMF or phosphoric acid hexamethyltriamide, Hydrocarbons such as benzene, toluene or xylene, halogenated hydrocarbons such as carbon tetrachloride or tetrachlorethylene and sulfoxides such as Dimethyl sulfoxide or sulfolane. Water immiscible solvents can at the same time advantageous for azeotropic distilling off the at Esterification of water formed can be used. Occasionally also a surplus of one organic base, e.g. Pyridine, quinoline or triethylamine, as solvent for the Esterification can be applied. The esterification can also be in the absence a solvent, e.g. by simply heating the components in the presence of sodium acetate, be performed. The reaction temperature is usually between -50 ° and + 250 °, preferably between -20 ° and + 80 °. In these Temperatures are the esterification reactions usually after 15 Minutes to 48 hours.

In particular, the reaction conditions for the esterification depend largely on the nature of the starting materials used. Thus, a free carboxylic acid is reacted with a free alcohol or phenol usually in the presence of a strong acid, for example a mineral acid such as hydrochloric acid or sulfuric acid. A preferred mode of reaction is the reaction of an acid anhydride or in particular an acid chloride with an alcohol, preferably in a basic medium, wherein as bases in particular alkali metal hydroxides such as sodium or potassium hydroxide, alkali metal carbonates or bicarbonates such as sodium carbonate, sodium bicarbonate, potassium carbonate or potassium bicarbonate, alkali metal acetates such as sodium or potassium acetate, alkaline earth metal hydroxides such as calcium hydroxide or organic bases such as triethylamine, pyridine, lutidine, collidine or quinoline are of importance.

A further preferred embodiment the esterification is that the alcohol or the Phenol first into the sodium or potassium alcoholate or phenate, e.g. by treatment with ethanolic soda or caustic potash, this isolated and with an acid anhydride or in particular acid chloride implements.

nitrites can by exchanging halogens with copper cyanide or alkali cyanide to be obtained.

In a further process for the preparation of the compounds of formula I wherein Z ¹ and / or Z ^{2 is} -CH = CH-, an aryl halide is reacted with an olefin in the presence of a tertiary amine and a palladium catalyst (see RF Heck, Acc Chem. Res. 12 (1979) 146). Suitable aryl halides are, for example, chlorides, bromides and iodides, in particular bromides and iodides. The tertiary amines required for the success of the coupling reaction, such as triethylamine, are also suitable as solvents. As palladium catalysts, for example, its salts, in particular Pd (II) acetate, with organic phosphorus (III) compounds such as triarylphosphines are suitable. It can be in the presence or absence of an inert solvent at temperatures between about 0 ° C and 150 ° C, preferably between 20 ° C and 100 ° C, work; Suitable solvents are, for example, nitriles such as acetonitrile or hydrocarbons such as benzene or toluene. The aryl halides and olefins used as starting materials are widely available commercially or can be prepared by literature methods, for example by halogenation of corresponding parent compounds or by elimination reactions of corresponding alcohols or halides.

On Stilbenderivate can be prepared in this way, for example. The Style levels can be further prepared by reacting a 4-substituted Benzaldehyde with a corresponding phosphorylide according to Wittig. But you can also produce tolans of formula I by replacing instead of the olefin used monosubstituted acetylene (Synthesis 627 (1980) or Tetrahedron Lett. 27, 1171 (1986)).

Farther can for the coupling of aromatic aryl halides with aryl tin compounds be implemented. These reactions are preferred with addition a catalyst such as e.g. a palladium (0) complex in inert solvents such as hydrocarbons at high temperatures, e.g. in boiling Xylene, carried out under protective gas.

couplings of alkynyl compounds with aryl halides can be prepared analogously to that of A.O. King, E. Negishi, F.J. Villani and A. Silveira in J. Org. Chem 43, 358 (1978).

tolans of the formula I in which Z is -C≡C- mean, can also over the Fritsch-Guttenberg-Wiechell rearrangement (Ann. 279, 319, 1984) are rearranged in the 1,1-diaryl-2-haloethylene become diarylacetylenes in the presence of strong bases.

tolans of the formula I can also be prepared by brominating the corresponding stilbene and subsequently subjected to dehydrohalogenation. It is possible to know, here unspecified variants apply this implementation.

Ethers of the formula I are obtainable by etherification of corresponding hydroxy compounds, preferably corresponding phenols, wherein the hydroxy compound is suitable first in a corresponding metal derivative, for example by treatment with NaH, NaNH ₂ , NaOH, KOH, Na ₂ CO ₃ or K ₂ CO ₃ in the corresponding alkali metal alcoholate or alkali metal phenolate is converted. This can then be reacted with the entprechenden alkyl halide, sulfonate or dialkyl sulfate, suitably in an inert solvent such as acetone, 1,2-dimethoxythane, DMF or dimethyl sulfoxide or with an excess of aqueous or aqueous-alcoholic NaOH or KOH at temperatures between about 20 ° C and 100 ° C.

to Preparation of laterally substituted fluorine or chlorine compounds of the formula I can corresponding aniline derivatives with sodium nitrite and either with tetrafluoroboric (for the introduction of an F atom) or with copper (I) chloride (for the introduction of a Cl atoms) are converted to the diazonium salts, which then at temperatures from 100 ° -140 ° thermally be decomposed.

The shortcut an aromatic nucleus with a non-aromatic nucleus or two non-aromatic nuclei are preferably obtained by condensation a lithium or organomagnesium compound with a ketone, if between the nuclei an aliphatic group Z should be.

The organometallic compounds are prepared, for example, by metal-halogen exchange (e.g., according to Org. React. 6, 339-366 (1951)) between the corresponding halogen compound and a organolithium compound such as preferably tert-butyllithium or lithium naphthalenide or by sales of magnesium turnings.

The linking of two aromatic rings or aliphatic group Z with an aromatic ring is preferably carried out by Friedel-Crafts alkylation or acylation by reacting the corresponding aromatic compounds under Lewis acid catalysis. Suitable Lewis acids are, for example, SnCl ₄ , ZnCl ₂ or especially AlCl ₃ and TiCl ₄ .

Farther let yourself The link of two aromatic rings by the Ullmann reaction (e.g., Synthesis 1974, 9) between aryl iodides with copper iodide, but preferably between an aryl-copper compound and an aryl iodide, or by the Gomberg-Bachmann reaction between an aryl diazonium salt and the corresponding aromatic compound (e.g., Org. React. 2, 224 (1944)). The representation of the tolans of formula I is e.g. through implementation the corresponding aryl halides with an acetylide in a basic solvent under transition metal catalysis; preferred here palladium catalysts are used, in particular a Mixture of bis (triphenylphosphine) palladium (II) chloride and copper iodide in piperidine as solvent.

Furthermore can the compounds of formula I are prepared by adding a Compound which otherwise corresponds to the formula I, but in place of H atoms one or more reducible groups and / or C-C bonds contains reduced.

Suitable reducible groups are preferably carbonyl groups, in particular keto groups, furthermore, for example, free or esterified hydroxy groups or aromatically bonded halogen atoms. Preferred starting materials for the reduction are compounds corresponding to formula I, but instead of a cyclohexane ring, a cyclohexene ring or cyclohexanone ring and / or in place of a -CH ₂ CH ₂ group a -CH = CH group and / or in place of a -CH ₂ group, a -CO group and / or instead of an H atom, a free or a functional (eg in the form of its p-toluenesulfonate) modified OH group.

The reduction can be carried out, for example, by catalytic hydrogenation at temperatures between about 0 ° and about 200 ° and pressures between about 1 and 200 bar in an inert solvent, for example an alcohol such as methanol, ethanol or isopropanol, an ether such as tetrahydrofuran (THF) or dioxane , an ester such as tetrahydrofuran (THF) or dioxane, an ester such as ethyl acetate, a carboxylic acid such as acetic acid or a hydrocarbon such as cyclohexane. Suitable catalysts are suitably noble metals such as Pt or Pd, which can be used in the form of oxides (eg PtO ₂ , PdO), on a support (eg Pd on carbon, calcium carbonate or strontium carbonate) or in finely divided form.

Ketones can also be prepared by the methods of Clemmensen (with zinc, amalgamated zinc or tin and hydrochloric acid, expediently in aqueous-alcoholic solution or in heterogeneous phase with water / toluene at temperatures between about 80 and 120 °) or Wolff-Kishner (with hydrazine, conveniently in the presence of alkali such as KOH or NaOH in a high boiling solvent such as diethylene glycol or triethylene glycol at temperatures between about 100 and 200 °) to the corresponding compounds of formula I containing alkyl groups and / or -CH ₂ CH ₂ bridges ,

Furthermore, reductions with complex hydrides are possible. For example, arylsulfonyloxy groups can be removed by reduction with LiAlH ₄ , in particular p-toluenesulfonyloxymethyl groups can be reduced to methyl groups, expediently in an inert solvent such as diethyl ether or THF at temperatures between about 0 and 100 °. Double bonds can be hydrogenated with NaBH ₄ or tributyltin hydride in methanol.

The Starting materials are either known or can analogously to known Connections are made.

The liquid-crystalline media preferably contain in addition to one or more inventive Compounds as further constituents 2 to 40, in particular 4 to 30 components. With very particular preference these media contain, in addition to one or more compounds according to the invention, 7 to 25 components. These further constituents are preferably selected from nematic or nematogenic (monotropic or isotropic) substances, in particular substances from the classes of azoxybenzenes, benzylideneanilines, biphenyls, terphenyls, phenyl or cyclohexyl benzoates, cyclohexane-carboxylic acid phenyl or cyclohexyl esters, phenyl or cyclohexyl esters Cyclohexylbenzoic acid, phenyl or cyclohexyl esters of cyclohexylcyclohexanecarboxylic acid, cyclohexyl phenyl esters of benzoic acid, of cyclohexanecarboxylic acid or of cyclohexylcyclohexanecarboxylic acid, phenylcyclohexanes, cyclohexylbiphenyls, phenylcyclohexylcyclohexanes, cyclohexylcyclohexanes, cyclohexylcyclohexylcyclohexenes, 1,4-biscyclohexylbenzenes, 4,4'-bis- cyclohexylbiphenyls, phenyl- or cyclohexylpyrimidines, phenyl- or cyclohexylpyridines, phenyl- or cyclohexyl-dioxanes, phenyl- or cyclohexyl-1,3-dithiane, 1,2-diphenylethane, 1,2-dicyclohexylethane, 1-phenyl-2-cyclohexylethane, 1 Cyclohexyl-2- (4-phenyl-cyclohexyl) -ethanes, 1-Cyc lohexyl-2-biphenylylethanes, 1-phenyl-2-cyclohexyl-phenylethanes, optionally halogenated stilbenes, benzylphenyl ethers, tolans and substituted cinnamic acids. The 1,4-phenylene groups in these compounds can also be fluorinated.

The most important compounds which may be considered as further constituents of these media can be characterized by the formulas 1, 2, 3, 4 and 5: R'-LE-R '' 1 R'-L-COO-E-R "2 R'-L-OOC-E-R "3 R'-L-CH ₂ CH ₂ -E-R "4 R'-LC≡CE-R "5

In the formulas 1, 2, 3, 4 and 5, L and E, the same or different could be, each independently each other is a bivalent radical from the group consisting of -Phe-, -Cyc-, -Phe-Phe-, -Phe-Cyc, -Cyc-Cyc, -Pyr-, -Dio, -G-Phe- and -G-Cyc- and their Mirror images formed group, with Phe unsubstituted or fluorine-substituted 1,4-phenylene, Cyc trans-1,4-cyclohexylene or 1,4-cyclohexylene, pyr pyrimidine-2-5-diyl or pyridine-2,5-diyl, Dio 1,3-dioxane-2,5-diyl and G 2- (trans-1,4-cyclohexyl) -ethyl, pyrimidine-2,5-diyl, Pyridine-2,5-diyl or 1,3-dioxane-2,5-diyl.

Preferably one of the radicals L and E is Cyc, Phe or Pyr. E is preferred Cyc, Phe or Phe-Cyc. Preferably, the liquid crystalline Media one or more components selected from the compounds of Formulas 1, 2, 3, 4 and 5, wherein L and E are selected from the group Cyc, Phe and Pyr and at the same time one or more components selected from the compounds of formulas 1, 2, 3, 4 and 5, wherein one of the radicals L and E selected is selected from the group Cyc, Phe and Pyr and the other radical is selected from the group -Phe-Phe-, -Phe-Cyc, -Cyc-Cyc, -G-Phe and -G-Cyc-, and optionally one or multiple components selected from the compounds of the formulas 1, 2, 3, 4 and 5, wherein the radicals L and E selected are from the group -Phe-Cyc, -Cyc-Cyc, -G-Phe and -G-Cyc-.

R 'and R' 'are in a smaller subgroup the compounds of formulas 1, 2, 3, 4 and 5 are each independently Alkyl, alkenyl, alkoxy, alkoxyalkyl, alkenyloxy or alkanoyloxy with up to 8 carbon atoms. Below is this smaller one Subgroup group A called and the compounds are with the Partial formulas 1a, 2a, 3a, 4a and 5a. For most of these Compounds are R 'and R '' different from each other, wherein one of these radicals is usually alkyl, alkenyl, alkoxy or alkoxyalkyl is.

In a smaller subgroup of compounds of formulas 1, 2, 3, 4 and 5, other than group B, R '' is -F, -Cl, -NCS or - (O) _i CH ₃ - _{(k + 1)} F _k Cl _l , where i is 0 or 1 and k and l are 1, 2 or 3; the compounds in which R "has this meaning are designated by the subformulae 1b, 2b, 3b, 4b and 5b. Particular preference is given to those compounds of the subformulae 1b, 2b, 3b, 4b and 5b in which R "has the meaning -F, -Cl, -NCS, -CF ₃ , -OCHF ₂ or -OCF ₃ .

In R 'has the compounds of the sub-formulas 1b, 2b, 3b, 4b and 5b in the compounds sub-formulas 1a-5a given meaning and is preferably alkyl, alkenyl, alkoxy or alkoxyalkyl.

In a further smaller subgroup of the compounds of the formulas 1, 2, 3, 4 and 5, R " -CN; this subgroup is referred to below as group C and the compounds of this subgroup are described respectively with sub-formulas 1c, 2c, 3c, 4c and 5c. In the compounds of sub-formulas 1c, 2c, 3c, 4c and 5c, R 'has the meaning given for the compounds of sub-formulas 1a-5a and is preferably alkyl, alkoxy or alkenyl.

Next the preferred compounds of groups A, B and C are also others Compounds of formulas 1, 2, 3, 4 and 5 with other variants the proposed substituents in use. All these substances are available by literature methods or in analogy thereto.

In addition to the compounds of the formula I according to the invention, the liquid-crystalline media preferably contain one or more compounds which are selected from the group A and / or group B and / or group C. The mass fractions of the compounds from these groups on the media according to the invention are preferably: Group A: 0 to 90%, preferably 20 to 90%, in particular 30 to 90% Group B: 0 to 80%, preferably 10 to 80%, in particular 10 to 65% Group C: 0 to 80%, preferably 5 to 80%, in particular 5 to 50% wherein the sum of the mass fractions of the compounds of the groups A and / or B and / or C contained in the respective liquid-crystalline media is preferably 5% -90% and in particular 10% to 90%.

The liquid crystalline Media preferably contain 1 to 40%, especially preferably 5 to 30% of the compounds of the invention. Further preferred are media containing more than 40%, in particular 45 to 90% of compounds of the invention. The media preferably contain three, four or five compounds according to the invention.

The Production of liquid crystalline Media is done in per se Wise. In general, the components are dissolved in each other, useful in increased Temperature. By suitable additives can they liquid crystalline Phases according to the invention are modified so that they are in all types of liquid crystal display elements known so far can be used. Such additives are known in the art and described in detail in the literature (H.Kalkker / R.Hatz, Handbook of Liquid Crystals, Verlag Chemie, Weinheim, 1980).

For example can pleochroic dyes for the preparation of colored guest-host systems or substances for change the dielectric anisotropy, the viscosity and / or orientation of the nematic phases are added.

The following examples are intended to illustrate the invention without limiting it. Above and below, percentages are by weight. All temperatures are in degrees Celsius. Mp means melting point Clp = clearing point. Furthermore, K = crystalline state, N = nematic phase, Sm = smectic phase and I = isotropic phase. The data between these symbols represent the transition temperatures. Δn means optical anisotropy (589 nm 20 ° C) and Δε the dielectric anisotropy (1 kHz, 20 ° C). The viscosity (mm ² / sec) was determined at 20 ° C.

"Usual processing" means: one gives optionally water added, extracted with methylene chloride, diethyl ether or toluene, separates, the organic phase is dried, evaporated and purifies the product by distillation under reduced pressure or crystallization and / or chromatography.

THF

Tetrahydrofuran

KOtBu

Kalium-tert.-butylat

RT

Raumtemperatur

MTB-Ether

Methyl-tert.-butylether

Verglechsbeispiele 4–11 und Beispiele 12–31:

Vergleichsbeispiele 32–39 und Beispiele 40–59:

Vergleischsbeispiele 60–66 und Beispiele 67–87

Beispiele 88–115:

Beispiele 116–126:

Beispiele 127–121:

The following abbreviations are used:

THF

tetrahydrofuran

KOtBu

Potassium tert-butoxide

RT

room temperature

MTB ether

Methyl tert-butyl ether

Comparative Examples 4-11 and Examples 12-31:

Comparative Examples 32-39 and Examples 40-59:

Comparative Examples 60-66 and Examples 67-87

Examples 88-115:

Examples 116-126:

Examples 127-121:

Claims (5)

Sulfur pentafluoride derivatives of the formula I or IA

wherein R ^{1 is} H, an unsubstituted, a simply by CN or CF ₃ or at least one halogen-substituted alkyl radical having 1-12 C atoms or alkenyl radical having 2-12 C atoms, wherein in these radicals also one or more non-adjacent CH ₂ groups are each independently of one another by -O-, -S-, -CO-, -CH = CH-,

May be replaced with -CO-O-, -O-CO- or -O-CO-O-, A ¹ and A ² a) trans -cyclohexane-1,4-diyl radical, in which also one or more non-adjacent CH ₂ - B) 1,4-phenylene radical, in which also one or two CH groups may be replaced by N, c) radical from the group consisting of 1,4-bicyclo (2 , 2,2) -octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl and 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein the Radicals a) and b) may be substituted by CN, Cl or F, and at least one of the radicals A ¹ / A ² in the formulas a naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2, 3,4-tetrahydronaphthalene-2,6-diyl L H or F, Z ¹ and Z ^{2 are} each independently of one another -CO-O-, -O-CO-, -CH ₂ O-, -O-, -O-CH ₂ , -CH ₂ CH ₂ -, - CH = CH-, -C≡C- or a single bond, and wherein for formula I n and m is 0.1 or 2, and n + m is 1 or 2, or for formula IA m is 1 or 2. Sulfur pentafluoride derivatives according to Claim 1, characterized in that R ¹ denotes straight-chain alkyl or alkoxy having 1 to 10 C atoms or alkenyl or alkenyloxy having 2 to 10 C atoms. Sulfur pentafluoride derivatives according to Claim 1 or 2, characterized in that the radicals Z ¹ and Z ^2, independently of one another, denote -CH ₂ CH ₂ -, -CH = CH-, -C≡C- or a single bond. Compounds according to claim 1 of the formula IB:

wherein R ¹ , A ¹ , Z ¹ , m and L have the meaning indicated. Use of compounds of the formula I, IA and IB according to claim 1 to 4 as components of liquid-crystalline media.