DE3939982A1 - New 2,4-substd.-phenyl or -bi:phenyl 5-substd.-alkyl pyridine cpds. - used in liq. crystal phase esp. dielectric for electro-optical display - Google Patents

Abstract

New 2-(4-substd.-(bi)phenyl)-5-(substd.-alkyl)-pyridine cpds. of formula (I) are new; where R1 and R2 independently = 1-12 C alkyl, alkenyl or oxaalkyl; L1 and L2 independently = H or F; Y = -O-, -CO-O, -O-CO- or a single bond; m = 1 or 2; Z = H,F,OH or 1-5 C alkyl; and Q = -O-, -O-CO- or, if z = F or OH, may also = a single bond. (I) may be prepd. by standard methods, e.g. as described in Houben-Weyl, Methoden der Organischen Chemie, George-Thieme-Verlag, Stuttgart. USE/ADVANTAGE - (I), which are pref. optically active, are claimed for use in chiral tilted smectic liq. crystal (LC) phases, esp. as dielectric for electroptical displays. They give stable chiral tilted smectic LC phases with favourable ferroelectric phase region, esp. with wide SC (asterisk) phase region, negative or positive dielectric anisotropy, low optical anisotropy, favourable pitch height, low viscosity, esc. low temp. dependence of the switching time, high spontaneous polarisation and very short switching times. (I) are also useful as intermediates for other substances used in LC phases.

Description

The invention relates to a 2,5-disubstituted heterocycle of formula I.

wherein

R¹ and R² each independently of one another alkyl, alkenyl or oxaalkyl with up to 12 C atoms,
L¹ and L² each independently of one another H or F,
Y -O-, -CO-O-, -O-CO- or a single bond,
m 1 or 2,
Z is H, F, OH or alkyl having up to 5 carbon atoms, and
Q -O-, -O-CO- or, if Z is fluorine or hydroxy, also means a single bond.

The compounds of formula I can be like similar in DE-OS 35 15 373 and DE-OS 35 15 374 described compounds as components of chiral tilted smectic liquid crystalline phases are used.

Chiral tilted smectic liquid crystalline phases with ferroelectric properties can be manufactured by using base mixtures with one or more tilted smectic phases with a suitable chiral dopant added (L.A. Beresnev et al., Mol. Cryst. Liq. Cryst. 89, 327 [1982]; H.R. Brand et al., J. Physique 44 [lett.], L-771 [1983]). Such phases can used as dielectrics for fast switching displays on the one described by Clark and Lagerwall Principle of SSFLC technology (N.A. Clark and S.T. Lagerwall, Appl. Phys. Lett. 36, 899 [1980]; USP 43 67 924) the basis of the ferroelectric properties of the chiral based phase. In this phase, the elongated ones are Molecules arranged in layers, the Molecules have a tilt angle to the layer normal. As it progresses from layer to layer, the changes Tilt direction by a small angle with respect to a vertical axis to the layers, so that a helical structure is trained. In displays based on the principle based on SSFLC technology are smectic Layers arranged perpendicular to the plates of the cell. The helical arrangement of the tilt directions of the molecules is due to a very small distance between the plates (approx. 1-2 µm) suppressed. As a result, the longitudinal axes of the Forced molecules to be parallel to each other in one plane Arrange plates of the cell, making two excellent Tilt orientations arise. By creating a suitable one alternating electrical field can be a spontaneous Liquid crystalline phase having polarization  toggled between these two states will. This switching process is much faster than with conventional twisted cells (TN-LCD's) that are based on based on nematic liquid crystals.

A big disadvantage for many applications of the currently available Materials with chiral tilted smectic Phases (such as Sc *) is their relatively high optical anisotropy, those due to relatively high viscosity values not sufficiently short switching times, and that the dielectric Anisotropy values greater than zero or, if negative, has little non-zero values. Negatives Dielectric anisotropy values are required if the required planar orientation Overlay of the control field with an AC holding field small amplitude (J.M. Geary, SID conference, Orlando / Florida, April / May 1985, lecture 8.3). In the end is the temperature dependency of the switching times at the moment available ferroelectric mixtures so large that in electronic compensation is required in many cases is.

It has now been found that the use of compounds of the formula I as components of chiral tilted smectic Mixtures significantly reduce the disadvantages mentioned can. The compounds of formula I are thus as components of chiral tilted smectic liquid crystalline Phases excellent. In particular are chemically particularly stable chirals with their help tilted smectic liquid crystalline phases with favorable ferroelectric phase areas, in particular with wide Sc * phase ranges, negative or too positive dielectric anisotropy, low optical Anisotropy, favorable pitch height, low viscosity, particularly low temperature dependence of the switching times  and for such phases high values for the spontaneous Polarization and very short switching times can be produced. P is the spontaneous polarization in nC / cm².

With the provision of the compounds of formula I will also generally the range of liquid crystalline Substances that can be found under various application technology Aspects of manufacturing ferroelectric Mixtures are suitable, considerably widened.

The compounds of formula I have a wide range of applications. Depending on the choice of substituents can use these compounds as base materials serve from which liquid crystalline phases predominantly Part are composed; but it can also Compounds of formula I liquid crystalline base materials added from other classes of compounds, for example the dielectric and / or optical anisotropy and / or the spontaneous polarization and / or the Phase range and / or the tilt angle and / or the pitch and / or to vary the switching times of such a phase. The compounds of formula I are also suitable as intermediates to produce other substances that are use as components of liquid crystalline phases to let.

The compounds of formula I are in a pure state colorless and show favorable values of optical anisotropy on. Some of the compounds of formula I liquid-crystalline mesophases in one for electro-optical Use of conveniently located temperature range, however, it can also be isotropic or monotropic liquid crystalline Compounds of formula I as components chiral tilted smectic phases are advantageously used will. Are chemical, thermal and against light they very stable.  

The invention thus relates to the compounds of Formula I and the use of the compounds of the formula I as components of liquid crystalline phases.

The invention also relates to chiral tilted smectic liquid crystalline phases containing at least a compound of formula I.

The invention further relates to electro-optical display elements, that contain such phases.

Above and below, R 1, R 2, m , L 1, L 2, Y, Z and Q have the meaning given, unless expressly stated otherwise.

The compounds of formula I accordingly include in particular compounds of the sub-formulas Ia and Ib:

Among them, those of the formula Ia are particularly preferred.

Compounds of the formulas above and below with branched ones Wing groups R¹ or R² can be important be. Branched groups of this type are included in the Usually no more than two chain branches. R1 is preferred a straight-chain group or a branched one Group with no more than one chain branch.  

Preferred branched radicals are isopropyl, 2-butyl (= 1- Methylpropyl), isobutyl (= 2-methylpropyl), tert.-butyl, 2-methylbutyl, isopentyl (= 3-methylbutyl), 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2-ethylhexyl, 5-methylhexyl, 2-propylpentyl, 6-methylheptyl, 7-methyloctyl, isopropoxy, 2-methylpropoxy, 2-methylbutoxy, 3-methylbutoxy, 2-methylpentoxy, 3-methylpentoxy, 2-ethylhexoxy, 1-methylhexoxy, 1-methylheptoxy, 2-oxa-3-methylbutyl, 3-oxa-4- methylpentyl.

The radical R¹ and in particular also the radical R² can also an optically active organic residue with an asymmetrical Be a carbon atom.

R¹ and R² are preferably alkyl or alkenyl up to 12 carbon atoms. Alkyl with are particularly preferred 2 to 12 carbon atoms, i. H. Ethyl, propyl, butyl, pentyl, Hexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl. These groups can be straight-chain or branched, straight chain alkyl groups are preferred. R² means however also preferably methyl or branched Alkyl with a methyl branch, e.g. B. isopropyl.

Y is preferably -O- or -CO-O-, particularly preferred -O-.

m is preferably 1.

The rest

preferably has one of the following Meanings 1 to 6:  

The meanings 1 and 2, in particular 1, are special prefers. The position of the fluorine in 6 is arbitrary.

The preferred compounds wherein Z is alkyl with up to 5 C atoms means are preferably optically active and are used as chiral dopants for ferroelectric Mixtures used. Z is preferably methyl, ethyl, n-propyl or iso-propyl. Methyl is particularly preferred.

The most preferred compounds, wherein Z is fluorine means are preferably optically active and are considered chiral dopants used for ferroelectric mixtures. In this case, Q is preferably a single bond and R² is preferably straight or branched Alkyl with up to 10 carbon atoms, preferably with 3 to 8 C atoms.

The preferred compounds in which Z is OH are interesting intermediates, especially for liquid crystals. In this case, Q is preferably a single bond and R² is preferably straight or branched Alkyl with up to 10 carbon atoms, preferably with 3 to 8 carbon atoms.  

The preferred compounds where Z is H are preferably achiral base materials for ferroelectric Mixtures. In this case, Q is -O- or -O-CO-.

Among the compounds of formula I and Ia to Id are preferred those in which at least one of them is included contained residues one of the preferred meanings indicated Has.

The compounds of formula I are known per se Methods produced as described in the literature (e.g. in the standard works such as Houben-Weyl, methods of organic chemistry, Georg-Thieme-Verlag, Stuttgart) are described, namely under reaction conditions, known and suitable for the above-mentioned implementations are. You can also from well-known, here make use of variants not mentioned in more detail.

If desired, the starting materials can also be in situ are formed such that they can be removed from the reaction mixture not isolated, but immediately to the Reacts compounds of formula I.

Thus, the compounds of formula I or their Suitable precursors are manufactured by to obtain a compound of the formula I ′,

wherein R¹, Y, L¹, L², m and X have the meaning given above, or a suitable precursor under basic conditions with an epoxide of formula II

implemented, wherein n is 0 to 12. If n is 1 to 12, an optically active epoxy is preferably used. The compounds of the formula Id according to the invention or, if ethylene oxide is used, the likewise new intermediates of the formula Ie

which are also the subject of the present invention and in which R 1, Y, L 1, L 2, m and X have the preferred meanings indicated above.

The reaction conditions of the implementation of I 'with epoxides are not critical in themselves. The 2- substituted 5-methylpyridines of formula I 'among the conditions mentioned in DE 36 32 411 (Example 3) (where the use of DMPU can be dispensed with) and then gives an equimolar amount at chiral at -10 ° C Epoxy of formula II too. The epoxy becomes regioselective opened the less substituted carbon atom and you get the corresponding (optically active) alcohols, which under Inversion with DAST (dimethylamino sulfur trifluoride) in the fluorine compounds of formula Ic according to the invention can be transferred (M. Hudlický, Organic Reactions 35, 513-637 [1988]). Etherification or esterification of the Alcohols under the conditions usual in the literature gives the ethers and esters of the formulas according to the invention Ia and Ib.  

The starting materials of formula II are known or available in analogy to known compounds. Various Compounds of formula II are commercial available. The starting materials of formula I 'are obtainable from 2-p-methoxyphenyl-5-methylpyridine basic ether cleavage with K-tert-butoxide in N-methylpyrrolidone (NMP) at 150 ° -200 ° C and then another Etherification with the corresponding alkyl halides or by cross-coupling the corresponding aromatic Boronic acids with 2-bromo-5-methylpyridine according to M. J. Sharp, W. Cheng and V. Snieckus, Tetrahedron Letters 28, 5093 (1987).

The phases according to the invention contain at least one, preferably at least two compounds of the formula I. Chiral tilted ones according to the invention are particularly preferred smectic liquid crystalline phases, their achiral Base mixture in addition to compounds of formula I at least another component with negative or amount contains small positive dielectric anisotropy. The chirality is preferably partially or completely based on chiral compounds of formula I. These Phases preferably contain one or two chiral compounds of formula I. However, it can also be achiral Compounds of formula I (for example in the form of a Racemates) are used, with the chirality the phase caused by other optically active compounds becomes. If chiral compounds of the formula I are used in addition to the purely optical ones Antipodes also mixtures with an enantiomeric excess. The above-mentioned further component (s) of the achiral Base mixture can be 1 to 50%, preferably 10 to 25% of the basic mix.

The compounds of formula I are also suitable as components nematic liquid crystalline phases, e.g. B. for Avoiding reverse twist.  

These liquid-crystalline phases according to the invention exist from 2 to 25, preferably 3 to 15 components, including at least one compound of formula I. Die other ingredients are preferably selected from the nematic or nematogenic substances, in particular the known substances from the classes of azoxybenzenes, Benzylidene anilines, biphenyls, terphenyls, phenyl or cyclohexyl benzoates, cyclohexane carboxylic acid phenyl or cyclohexyl esters, phenylcyclohexanes, cyclohexylbiphenyls, Cyclohexylcyclohexanes, cyclohexylnaphthalenes, 1,4-bis-cyclohexylbenzenes, 4,4'-bis-cyclohexylbiphenyls, Phenyl- or cyclohexylpyrimidines, phenyl- or cyclohexylpyridazines as well as their N-oxides, phenyl- or cyclohexyldioxanes, Phenyl- or cyclohexyl-1,3-dithiane, 1,2-diphenylethane, 1,2-dicyclohexylethane, 1-phenyl-2- cyclohexylethanes, optionally halogenated stilbenes, Benzylphenyl ether, tolanes and substituted cinnamic acids.

The most important as components of such liquid crystalline Leave phases in question are characterized by the formula I ′,

R′-L-G-E-R ′ ′ (I ′)

where L and E each have a carbocyclic or heterocyclic ring system from that from 1,4-disubstituted benzene and Cyclohexane rings, 4,4′-disubstituted biphenyl, Phenylcyclohexane and cyclohexylcyclohexane systems, 2,5-disubstituted pyrimidine and 1,3-dioxane rings, 2,6-disubstituted naphthalene, di- and tetrahydronaphthalene, Quinazoline and tetrahydroquinazoline formed Group,  

or a single C-C bond,

Y halogen, preferably chlorine, or -CN, and

R ′ and R ′ ′ alkyl, alkoxy, alkanoyloxy, alkoxycarbonyl or alkoxycarbonyloxy with up to 18, preferably up to to 8 carbon atoms, or one of these residues also CN, NC, NO₂, CF₃, F, Cl or Br mean.

For most of these compounds, R 'and R' 'are from each other different, with one of these residues mostly is an alkyl or alkoxy group. But others too Variants of the proposed substituents are common. Many such substances or mixtures thereof are commercially available. All of these substances are available according to methods known from the literature.

The phases according to the invention contain about 0.1 to 99, preferably 10 to 95%, one or more compounds of formula I. Furthermore preferred according to the invention liquid-crystalline phases, containing 0.1-40, preferably 0.5-30% of one or more compounds of formula I.

The phases according to the invention are produced in in a usual way. As a rule, the components dissolved in one another, expediently at elevated temperature.  

By means of suitable additives, the liquid crystalline Phases according to the invention are modified so that they in all types of liquid crystal display elements that have become known can be used.

The following examples are intended to illustrate the invention, without limiting it. Mp. = Melting point, Kp. = Clearing point. Percentages above and below mean percentages by weight; all temperatures are given in degrees Celsius. "Normal work-up" means: water is added, extracted with methylene chloride, separated, dried organic phase, evaporates and purifies the product by crystallization and / or chromatography.

It also means:
K: crystalline solid state, S: smectic phase (the index indicates the phase type), N: nematic state, Ch: cholesteric phase, I: isotropic phase. The number between two symbols indicates the transition temperature in degrees Celsius.

example 1

With exclusion of moisture and N₂ atmosphere there to a solution of 90 ml THF (tetrahydrofuran) and 15.6 ml diisopropylamine 70 ml of a solution of n-BuLi in hexane at about -40 ° C and then at the same Temperature 29.7 g of 2-p-octyloxyphenyl-5-methylpyridine dissolved in 100 ml THF. The reaction mixture is stirred 30 minutes at -10 ° C and then add 12.8 g optically active 1,2-epoxioctane dissolved in 20 ml THF. You stir then 3 hours at room temperature and works then on as usual. Optically active 2-p Octyloxyphenyl-5- (3-hydroxynonyl) pyridine.  

The following are produced analogously:
2-p-nonyloxyphenyl-5- (3-hydroxynonyl) pyridine
2-p-decyloxyphenyl-5- (3-hydroxynonyl) pyridine
2-p-Undecyloxyphenyl-5- (3-hydroxynonyl) pyridine
2-p-dodecyloxyphenyl-5- (3-hydroxynonyl) pyridine
2-p- (1,4-dioxanonyl) phenyl-5- (3-hydroxynonyl) pyridine
2-p- (7-octenyloxy) phenyl-5- (3-hydroxynonyl) pyridine
2- (4-octyloxybiphenyl-4'-yl) -5- (3-hydroxynonyl) pyridine
2- (3-fluoro-4-octyloxy) phenyl-5- (3-hydroxynonyl) pyridine
2- (2-fluoro-4-octyloxy) phenyl-5- (3-hydroxynonyl) pyridine
2-p-octanoyloxyphenyl-5- (3-hydroxynonyl) pyridine

Example 2

To a solution of 10.6 g of optically active 2-p-octyloxyphenyl-5- (3-hydroxynonyl) pyridine in 70 ml of dichloromethane, 5 ml of DAST dissolved in 10 ml of dichloromethane are added dropwise at -20 ° C. with exclusion of moisture. After the reaction is complete, the reaction mixture is poured onto ice water and then worked up as usual. Optically active 2-p-octyloxyphenyl-5- (3-fluorononyl) pyridine, K 66 S _I * 73 S _C * 86 S _A 90 I is obtained.

The following are produced analogously:
2-p-octyloxyphenyl-5- (3-fluoro-butyl) pyridine
2-p-octyloxyphenyl-5- (3-fluoropentyl) pyridine
2-p-octyloxyphenyl-5- (3-fluoro-hexyl) pyridine
2-p-octyloxyphenyl-5- (3-fluoro-heptyl) pyridine
2-p-octyloxyphenyl-5- (3-fluoro-octyl) pyridine
2-p-octyloxyphenyl-5- (3-fluoro-decyl) pyridine
2-p-octyloxyphenyl-5- (3-fluoro-undecyl) pyridine
2-p-octyloxyphenyl-5- (3-fluorododecyl) pyridine
2-p-hexyloxyphenyl-5- (3-fluoro-butyl) pyridine
2-p-hexyloxyphenyl-5- (3-fluoropentyl) pyridine
2-p-hexyloxyphenyl-5- (3-fluoro-hexyl) pyridine
2-p-hexyloxyphenyl-5- (3-fluoro-heptyl) pyridine
2-p-hexyloxyphenyl-5- (3-fluoro-octyl) pyridine
2-p-hexyloxyphenyl-5- (3-fluoro-nonyl) pyridine
2-p-hexyloxyphenyl-5- (3-fluoro-decyl) pyridine
2-p-hexyloxyphenyl-5- (3-fluoro-undecyl) pyridine
2-p-Hexyloxyphenyl-5- (3-fluorododecyl) pyridine
2-p-Hexyloxyphenyl-5- (3-fluoro-4-methylpentyl) pyridine
2-p-heptyloxyphenyl-5- (3-fluoro-butyl) pyridine
2-p-heptyloxyphenyl-5- (3-fluoropentyl) pyridine
2-p-heptyloxyphenyl-5- (3-fluoro-hexyl) pyridine
2-p-heptyloxyphenyl-5- (3-fluoro-heptyl) pyridine
2-p-heptyloxyphenyl-5- (3-fluoro-octyl) pyridine
2-p-heptyloxyphenyl-5- (3-fluoro-nonyl) pyridine
2-p-heptyloxyphenyl-5- (3-fluoro-decyl) pyridine
2-p-heptyloxyphenyl-5- (3-fluoro-undecyl) pyridine
2-p-heptyloxyphenyl-5- (3-fluoro-dodecyl) pyridine
2-p-heptyloxyphenyl-5- (3-fluoro-4-methylpentyl) pyridine
2-p-nonyloxyphenyl-5- (3-fluoro-butyl) pyridine
2-p-nonyloxyphenyl-5- (3-fluoropentyl) pyridine
2-p-nonyloxyphenyl-5- (3-fluoro-hexyl) pyridine
2-p-nonyloxyphenyl-5- (3-fluoro-heptyl) pyridine
2-p-nonyloxyphenyl-5- (3-fluoro-octyl) pyridine
2-p-nonyloxyphenyl-5- (3-fluoro-nonyl) pyridine
2-p-nonyloxyphenyl-5- (3-fluoro-decyl) pyridine
2-p-nonyloxyphenyl-5- (3-fluoro-undecyl) pyridine
2-p-Nonyloxyphenyl-5- (3-fluorododecyl) pyridine
2-p-nonyloxyphenyl-5- (3-fluoro-4-methylpentyl) pyridine
2-p-decyloxyphenyl-5- (3-fluoro-butyl) pyridine
2-p-decyloxyphenyl-5- (3-fluoropentyl) pyridine
2-p-decyloxyphenyl-5- (3-fluoro-hexyl) pyridine
2-p-decyloxyphenyl-5- (3-fluoro-heptyl) pyridine
2-p-decyloxyphenyl-5- (3-fluoro-octyl) pyridine
2-p-decyloxyphenyl-5- (3-fluoro-nonyl) pyridine
2-p-decyloxyphenyl-5- (3-fluoro-decyl) pyridine
2-p-decyloxyphenyl-5- (3-fluoro-undecyl) pyridine
2-p-decyloxyphenyl-5- (3-fluorododecyl) pyridine
2-p-decyloxyphenyl-5- (3-fluoro-4-methylpentyl) pyridine
2- (3-fluoro-4-octyloxyphenyl-5- (3-fluoro-butyl) pyridine
2- (3-fluoro-4-octyloxyphenyl-5- (3-fluoro-pentyl) pyridine
2- (3-fluoro-4-octyloxyphenyl-5- (3-fluoro-hexyl) pyridine
2- (3-fluoro-4-octyloxyphenyl-5- (3-fluoro-heptyl) pyridine
2- (3-fluoro-4-octyloxyphenyl-5- (3-fluoro-octyl) pyridine
2- (3-fluoro-4-octyloxyphenyl-5- (3-fluoro-nonyl) pyridine
2- (3-fluoro-4-octyloxyphenyl-5- (3-fluoro-decyl) pyridine
2- (3-fluoro-4-octyloxyphenyl-5- (3-fluoro-undecyl) pyridine
2- (3-fluoro-4-octyloxyphenyl-5- (3-fluoro-dodecyl) pyridine
2- (3-fluoro-4-octyloxyphenyl-5- (3-fluoro-4-methylpentyl) pyridine
2- (2,3-difluoro-4-octyloxyphenyl-5- (3-fluoro-butyl) pyridine
2- (2,3-difluoro-4-octyloxyphenyl-5- (3-fluoropentyl) pyridine
2- (2,3-difluoro-4-octyloxyphenyl-5- (3-fluoro-hexyl) pyridine
2- (2,3-difluoro-4-octyloxyphenyl-5- (3-fluoro-heptyl) pyridine
2- (2,3-difluoro-4-octyloxyphenyl-5- (3-fluoro-octyl) pyridine
2- (2,3-difluoro-4-octyloxyphenyl-5- (3-fluoro-nonyl) pyridine
2- (2,3-difluoro-4-octyloxyphenyl-5- (3-fluoro-decyl) pyridine
2- (2,3-difluoro-4-octyloxyphenyl-5- (3-fluoro-undecyl) pyridine
2- (2,3-difluoro-4-octyloxyphenyl-5- (3-fluorododecyl) pyridine
2- (2,3-difluoro-4-octyloxyphenyl-5- (3-fluoro-4-methylpentyl) pyridine

Example 3

By esterifying optically active 2-p-octyloxyphenyl 5- (3-hydroxybutyl) pyridine (obtainable as in Example 1 by reacting 2-p-octyloxyphenyl-5-methylpyridine with chiral propylene oxide) with n-pentanoic acid gives 2-p- Octyloxyphenyl-5- (3-pentanoyloxy-butyl) pyridine, K 37 I.  

Example 4

By etherification of 2-p-octyloxyphenyl-5- (3-hydroxypropyl) - pyridine (obtainable analogously to Example 1 by reaction of 2-p-octyloxyphenyl-5-methylpyridine with ethylene oxide) n-butyl bromide gives 2-p-octyloxyphenyl-5- (4-oxaoctyl) pyridine.

The following are produced analogously:
2-p-octyloxyphenyl-5- (4-oxaheptyl) pyridine
2-p-octyloxyphenyl-5- (4-oxanonyl) pyridine
2-p-octyloxyphenyl-5- (4-oxadecyl) pyridine
2-p-octyloxyphenyl-5- (4-oxaundecyl) pyridine
2-p-octyloxyphenyl-5- (4-oxadodecyl) pyridine
2-p-nonyloxyphenyl-5- (4-oxapentyl) pyridine
2-p-nonyloxyphenyl-5- (4-oxahexyl) pyridine
2-p-nonyloxyphenyl-5- (4-oxaheptyl) pyridine
2-p-nonyloxyphenyl-5- (4-oxaoctyl) pyridine
2-p-nonyloxyphenyl-5- (4-oxanonyl) pyridine
2-p-nonyloxyphenyl-5- (4-oxadecyl) pyridine
2-p-nonyloxyphenyl-5- (4-oxaundecyl) pyridine
2-p-nonyloxyphenyl-5- (4-oxadodecyl) pyridine
2-p-nonyloxyphenyl-5- (4-oxa-6-methyloctyl) pyridine
2-p-decyloxyphenyl-5- (4-oxapentyl) pyridine
2-p-decyloxyphenyl-5- (4-oxahexyl) pyridine
2-p-decyloxyphenyl-5- (4-oxaheptyl) pyridine
2-p-decyloxyphenyl-5- (4-oxaoctyl) pyridine
2-p-decyloxyphenyl-5- (4-oxanonyl) pyridine
2-p-decyloxyphenyl-5- (4-oxadecyl) pyridine
2-p-decyloxyphenyl-5- (4-oxaundecyl) pyridine
2-p-decyloxyphenyl-5- (4-oxadodecyl) pyridine
2-p-decyloxyphenyl-5- (4-oxa-6-methyloctyl) pyridine
2-p-dodecyloxyphenyl-5- (4-oxapentyl) pyridine
2-p-dodecyloxyphenyl-5- (4-oxahexyl) pyridine
2-p-dodecyloxyphenyl-5- (4-oxaheptyl) pyridine
2-p-dodecyloxyphenyl-5- (4-oxaoctyl) pyridine
2-p-dodecyloxyphenyl-5- (4-oxanonyl) pyridine
2-p-dodecyloxyphenyl-5- (4-oxadecyl) pyridine
2-p-dodecyloxyphenyl-5- (4-oxaundecyl) pyridine
2-p-dodecyloxyphenyl-5- (4-oxadodecyl) pyridine
2-p-dodecyloxyphenyl-5- (4-oxa-6-methyloctyl) pyridine
2-p-heptyloxyphenyl-5- (4-oxapentyl) pyridine
2-p-heptyloxyphenyl-5- (4-oxahexyl) pyridine
2-p-heptyloxyphenyl-5- (4-oxaheptyl) pyridine
2-p-heptyloxyphenyl-5- (4-oxaoctyl) pyridine
2-p-heptyloxyphenyl-5- (4-oxanonyl) pyridine
2-p-heptyloxyphenyl-5- (4-oxadecyl) pyridine
2-p-heptyloxyphenyl-5- (4-oxaundecyl) pyridine
2-p-heptyloxyphenyl-5- (4-oxadodecyl) pyridine
2-p-heptyloxyphenyl-5- (4-oxa-6-methyoctyl) pyridine
2-p-hexyloxyphenyl-5- (4-oxapentyl) pyridine
2-p-hexyloxyphenyl-5- (4-oxahexyl) pyridine
2-p-hexyloxyphenyl-5- (4-oxaheptyl) pyridine
2-p-hexyloxyphenyl-5- (4-oxaoctyl) pyridine
2-p-hexyloxyphenyl-5- (4-oxanonyl) pyridine
2-p-hexyloxyphenyl-5- (4-oxadecyl) pyridine
2-p-hexyloxyphenyl-5- (4-oxaundecyl) pyridine
2-p-hexyloxyphenyl-5- (4-oxadodecyl) pyridine
2-p-Hexyloxyphenyl-5- (4-oxa-6-methyloctyl) pyridine
2-p-butyloxyphenyl-5- (4-oxapentyl) pyridine
2-p-butyloxyphenyl-5- (4-oxahexyl) pyridine
2-p-butyloxyphenyl-5- (4-oxaheptyl) pyridine
2-p-butyloxyphenyl-5- (4-oxaoctyl) pyridine
2-p-butyloxyphenyl-5- (4-oxanonyl) pyridine
2-p-butyloxyphenyl-5- (4-oxadecyl) pyridine
2-p-butyloxyphenyl-5- (4-oxaundecyl) pyridine
2-p-butyloxyphenyl-5- (4-oxadodecyl) pyridine
2-p-butyloxyphenyl-5- (4-oxa-6-methyloctyl) pyridine
2-p-ethoxyphenyl-5- (4-oxapentyl) pyridine
2-p-ethoxyphenyl-5- (4-oxahexyl) pyridine
2-p-ethoxyphenyl-5- (4-oxaheptyl) pyridine
2-p-ethoxyphenyl-5- (4-oxaoctyl) pyridine
2-p-ethoxyphenyl-5- (4-oxanonyl) pyridine
2-p-ethoxyphenyl-5- (4-oxadecyl) pyridine
2-p-ethoxyphenyl-5- (4-oxaundecyl) pyridine
2-p-ethoxyphenyl-5- (4-oxadodecyl) pyridine
2-p-ethoxyphenyl-5- (4-oxa-6-methyloctyl) pyridine
2-p-methoxyphenyl-5- (4-oxapentyl) pyridine
2-p-methoxyphenyl-5- (4-oxahexyl) pyridine
2-p-methoxyphenyl-5- (4-oxaheptyl) pyridine
2-p-methoxyphenyl-5- (4-oxaoctyl) pyridine
2-p-methoxyphenyl-5- (4-oxanonyl) pyridine
2-p-methoxyphenyl-5- (4-oxadecyl) pyridine
2-p-methoxyphenyl-5- (4-oxaundecyl) pyridine
2-p-methoxyphenyl-5- (4-oxadodecyl) pyridine
2-p-methoxyphenyl-5- (4-oxa-6-methyloctyl) pyridine

Example 5

A mixture consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine,
3% 2-p-heptyloxyphenyl-5-heptylpyrimidine,
3% 2-p-octyloxyphenyl-5-heptylpyrimidine,
3% 2-p-nonyloxyphenyl-5-heptylpyrimidine,
7% 2-p-hexyloxyphenyl-5-nonylpyrimidine,
23% 2-p-nonyloxyphenyl-5-nonylpyrimidine,
28% r-1-cyano-cis-4- (4'-octyloxybiphenyl-4-yl) -1-butylcyclohexane,
14% r-1-cyano-cis-4- (4'-heptylbiphenyl-4-yl) -1-hexylcyclohexane,
6% r-1-cyano-cis-4- (trans-4-pentylcyclohexyl) -1- (trans-4-pentylcyclohexyl) cyclohexane and
10% chiral 2-pn-octyloxyphenyl-5- (3-fluoro-nonyl) pyridine,

shows K <-20 S _c * 76 S _A 84 Ch 97 I, a spontaneous polarization of 11.3 nC / cm² at 20 ° and a switching time of 150 µs at 15 V / µm.

Example 6

If the chiral pyridine in the mixture from Example 5 is replaced by 10% chiral 2-p-octyloxyphenyl-5- (3-pentanoyloxy-butyl) pyridine, the ferroelectric mixture obtained S _c * 66 S _A 72 Ch 88 I shows a spontaneous Polarization of 8.5 nC / cm² at 20 ° and a switching time of 170 µs at 15 V / µm.

Claims (10)

1. 2,5-disubstituted heterocycle of the formula I. wherein R¹ and R² each independently of one another alkyl, alkenyl or oxaalkyl with up to 12 C atoms,
L¹ and L² each independently of one another H or F,
Y -O-, -CO-O-, -O-CO- or a single bond,
m 1 or 2,
Z is H, F, OH or alkyl having up to 5 carbon atoms, and
Q -O-, -O-CO- or, if Z is fluorine or hydroxy, also means a single bond. 2. heterocycle according to claim 1, characterized by the formula Ia wherein n is 0 or 1 and R¹, R², Y, L¹, L² and m have the meaning given in claim 1. 3. heterocycle according to claim 2, characterized in that that it is optically active. 4. heterocycle according to claim 1, characterized by the formula Ib wherein n is 0 or 1 and R¹, R², Y, L¹, L² and m have the meaning given in claim 1. 5. heterocycle according to claim 1, characterized by the formula Ic wherein R¹, R², Y, L¹, L² and m have the meaning given in claim 1. 6. heterocycle according to claim 5, characterized in that that it is optically active.   7. heterocycle according to claim 1, characterized by the formula Id wherein R¹, R², Y, L¹, L² and m have the meaning given in claim 1. 8. Chiral tilted smectic liquid crystalline Phase with at least two liquid crystalline components, characterized in that at least a connection to at least one of the Claims 1 to 7 contains. 9. Use of the compounds after at least one of claims 1 to 7 as components of liquid crystalline Phases. 10. Electro-optical display element, characterized in that there is a phase after as a dielectric Claim 8 contains.