Aromatic isothiocyanates

Abstract

The present invention relates to a compound of formula (UI) as defined in claim 1, to a liquid crystal medium comprising a compound of formula (UI) and to high-frequency components comprising these media, in particular microwave components for high-frequency devices, such as microwave phase shift devices, tunable filters, tunable metamaterial structures and electronic beam steering antennas, such as phased array antennas.

Description

[0001] The present invention relates to aromatic isothiocyanates, liquid crystal media containing the same and to high-frequency components containing these media, in particular microwave components for high-frequency devices such as microwave phase shifting devices, tunable filters, tunable metamaterial structures and electronic beam steering antennas (e.g. phased array antennas), and to devices containing the components.

[0002] Liquid-crystalline media have been used for many years in electro-optical displays (liquid crystal displays: LCD) for displaying information. However, more recently, liquid-crystalline media have also been proposed for use in components for microwave technology, such as in DE 10 2004 029 429.1 A and JP 2005-120208 (A).

[0003] A. Gaebler, F. Goelden, S. Müller, A. Penirschke and R. Jakoby, "Direct Simulation of Material Permittivites using an Eigen-Susceptibility Formulation of the Vector Variational Approach", 12 MTC 2009-International Instrumentation and Measurement Technology Conference, Singapore, 2009 (IEEE), pp. 463-467 describe the corresponding properties of the known liquid crystal mixture E7 (Merck KGaA, Germany).

[0004] DE 10 2004 029 429 A describes the use of liquid-crystalline media in microwave technology, in particular in phase shifters. The properties of liquid-crystalline media in the corresponding frequency range are discussed therein, and liquid-crystalline media based on mixtures of predominantly aromatic nitriles and isothiocyanates are demonstrated.

[0005] Fluorine atoms are frequently used in mesogenic compounds to introduce polarity. Especially in combination with terminal NCS groups, high dielectric anisotropy values ​​can be achieved, especially when the NCS group in the 1-position has two fluorine atoms in its ortho positions, since the overall molecular dipole is the sum of all the individual dipoles of the molecular part structures. On the other hand, since fluorine substitution generally has a negative effect on the nematic properties of the compounds, a well-balanced compromise has to be found with regard to the number of fluorine atoms.

[0006] In EP 2 982 730 A1, mixtures consisting entirely of isothiocyanate compounds are described.

[0007] However, compositions that can be used in microwave applications still have several disadvantages. There is a need to improve the general physical properties, shelf life and stability of these media when operated in devices. In view of the many different parameters that must be considered and improved in order to develop liquid crystal media for microwave applications, it is desirable to have a wider range of possible mixture components for developing such liquid crystal media.

[0008] It was an object of the present invention to provide compounds for use in liquid-crystalline media having improved properties in connection with applications in the microwave range of the electromagnetic spectrum.

[0009] To solve this problem, a compound of the formula UI defined below and a liquid crystal medium comprising the compound are provided.

[0010] The present invention relates to a compound of formula UI,

[0011]

[0012] in

[0013] R U represents H, a straight-chain or branched non-fluorinated alkyl group having 1 to 12 C atoms or a non-fluorinated alkenyl group having 2 to 12 C atoms, wherein one or more CH2- groups may be replaced by substitution, wherein one or more non-adjacent CH2-groups may be replaced by O, or represents a group R P ,

[0014] R P Indicates halogen, CN, NCS, fluorinated alkyl, R F -O- or R F -S-, where

[0015] R F represents a fluorinated alkyl or fluorinated alkenyl group having up to 9 C atoms,

[0016] Z U1 represents -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or -C≡CC≡C-, preferably -CF=CF- or -C≡C-,

[0017] X U1 , X U2 Identically or differently represents Cl or F, preferably F.

[0018]

[0019] represents a group selected from the following group:

[0020] a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L,

[0021] b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydronaphthalene-2,6-diyl, tetrahydronaphthalene-5,8-diyl, decahydronaphthalene-2,6-diyl, bicyclo[1.1.1]pentane-1,3-diyl, 4,4′-dicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl and spiro[3.3]heptane-2,6-diyl, in which one or two CH groups may be replaced by N, one or more non-adjacent CH2 groups may be replaced by -O- and / or -S-, and in which one or more H atoms may be replaced by L,

[0022] c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may also be mono- or poly-substituted by L,

[0023] L, identically or differently on each occurrence, represents F, Cl, CN, SCN, SF5 or linear or branched, in each case optionally fluorinated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, each having 1 to 12 C atoms,

[0024] u is 0 or 1,

[0025] v is 0 or 1,

[0026] The restriction condition is does not simultaneously represent an optionally fluorinated 1,4-phenylene group.

[0027] According to another aspect of the present invention, there is provided a liquid crystal medium comprising one or more compounds of formula UI.

[0028] Preferred embodiments of the invention are the subject matter of the dependent claims or can also be taken from the description.

[0029] Surprisingly, it has been found that it is possible to achieve liquid-crystalline media having excellent stability and at the same time high dielectric anisotropy, reasonably fast switching times, a suitable nematic phase range, high tunability and low dielectric losses in the microwave range of the electromagnetic spectrum by using compounds of the formula UI in liquid-crystalline media.

[0030] In particular, the medium according to the invention comprising the compound according to the invention is distinguished by an improved quality factor η due to a higher tunability τ and lower dielectric losses.

[0031] The media according to the invention are also characterized by a high brightness temperature, a broad nematic phase range and excellent low temperature stability (LTS). Thus, devices containing the media can be operated under extreme temperature conditions.

[0032] The medium is further characterized by a high dielectric anisotropy value and a low rotational viscosity. Therefore, the threshold voltage, i.e. the minimum voltage at which the device can switch, is very low. Low operating voltage and low threshold voltage are required in order to enable the device to have improved switching characteristics and high energy efficiency. Low rotational viscosity enables fast switching of the device according to the invention.

[0033] These properties overall make the medium particularly suitable for components and devices in high-frequency technology and for applications in the microwave range, in particular microwave phase shifting devices, tunable filters, tunable metamaterial structures and electronic beam steering antennas (eg phased array antennas).

[0034] Thus, according to another aspect of the invention, there is provided a component and a device comprising the component, both of which are operable in the microwave region of the electromagnetic spectrum. Preferred components are phase shifters, varactor diodes, wireless and radio wave antenna arrays, matching circuits and adaptable filters.

[0035] Herein, “high-frequency technology” means the use of electromagnetic radiation with a frequency in the range of 1 MHz to 1 THz, preferably 1 GHz to 500 GHz, more preferably 2 GHz to 300 GHz, particularly preferably about 5 GHz to 150 GHz.

[0036] As used herein, halogen is F, Cl, Br or I, preferably F or Cl, and particularly preferably F.

[0037] In this context, alkyl is linear or branched or cyclic and has 1 to 15 C atoms, preferably linear and, unless otherwise indicated, has 1, 2, 3, 4, 5, 6 or 7 C atoms, and is therefore preferably methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl or n-heptyl.

[0038] In this context, the branched alkyl group is preferably isopropyl, sec-butyl, isobutyl, isopentyl, 2-methylbutyl, 2-methylhexyl or 2-ethylhexyl.

[0039] As used herein, cycloalkyl means a straight-chain or branched alkyl or alkenyl radical having up to 12 C atoms, preferably an alkyl radical having 1 to 7 C atoms, wherein the radical CH2 is replaced by a carbocyclic ring having 3 to 5 C atoms, very preferably selected from the group consisting of cyclopropylalkyl, cyclobutylalkyl, cyclopentylalkyl and cyclopentenylalkyl.

[0040] Herein, alkoxy is straight-chain or branched and contains 1 to 15 C atoms. Alkoxy is preferably straight-chain and, unless otherwise indicated, has 1, 2, 3, 4, 5, 6 or 7 C atoms and is therefore preferably methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy or n-heptoxy.

[0041] Herein, alkenyl is preferably an alkenyl with 2 to 15 C atoms, the alkenyl being straight or branched, and containing at least one C-C double bond. The alkenyl is preferably straight chain, and has 2 to 7 C atoms. Therefore, the alkenyl is preferably vinyl, prop-1-enyl or prop-2-enyl, but-1-enyl, but-2-enyl or but-3-enyl, pent-1-enyl, pent-2-enyl, pent-3-enyl or pent-4-enyl, hex-1-enyl, hex-2-enyl, hex-3-enyl, hex-4-enyl or hex-5-enyl, hept-1-enyl, hept-2-enyl, hept-3-enyl, hept-4-enyl, hept-5-enyl or hept-6-enyl. If two C atoms of the C-C double bond are substituted, the alkenyl may be in the form of E and / or Z isomers (trans / cis). Generally speaking, the corresponding E isomer is preferred. Among the alkenyl groups, prop-2-enyl, but-2-enyl and but-3-enyl and also pent-3-enyl and pent-4-enyl are particularly preferred.

[0042] Herein, alkynyl is understood to mean an alkynyl radical having 2 to 15 C atoms, which is straight-chain or branched and contains at least one C—C triple bond. 1-Propynyl and 2-propynyl as well as 1-, 2- and 3-butynyl are preferred.

[0043] If R F represents a halogenated alkyl-, alkoxy-, alkenyl or alkenyloxy group, which may be branched or unbranched. Preferably, it is unbranched, monofluorinated, polyfluorinated or perfluorinated, preferably perfluorinated, and has 1, 2, 3, 4, 5, 6 or 7 C atoms, in the case of alkenyl, 2, 3, 4, 5, 6 or 7 C atoms.

[0044] R P Preferably represents CN, NCS, Cl, F, -(CH2) n -CH=CF2、-(CH2) n -CH=CHF, -(CH2) n -CH=Cl2、-C n F 2n+1 、-(CF2) n -CF2H, -(CH2) n -CF3, -(CH2) n -CHF2, -(CH2) n CH2F, -CH=CF2, -O(CH2)n -CH=CF2、-O(CH2) n CHCl2, -OC n F 2n+1 、-O(CF2) n -CF2H, -O(CH2) n CF3, -O(CH2) n -CHF2, -O(CF) n CH2F, -OCF=CF2, -SC n F 2n+1 、-S(CF) n -CF3, wherein n is an integer from 0 to 7.

[0045] Structurally related compounds having trifluorovinyl substituents are shown in CN105294526A for use as co-components in media for display devices.

[0046] The compounds of the general formula UI are prepared by methods known per se, specifically under reaction conditions known and suitable for the reaction, as described in the literature, for example in standard works such as Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Georg-Thieme-Verlag, Stuttgart. Variants known per se but not mentioned here in greater detail can be used here.

[0047] If desired, the starting materials can also be formed in situ without isolating them from the reaction mixture, but rather by reacting them immediately further to form the compound of the general formula UI.

[0048] Preferred synthetic routes to the compounds according to the invention are illustrated in the following Scheme 1, in which the radicals and parameters occurring have the meanings given for the formula UI. They are further illustrated with the aid of the working examples and can be adapted to the specific desired compounds of the general formula UI by selecting suitable starting materials.

[0049] Preferred building blocks 2 (Scheme 1) are 4-bromo-3,5-difluoroaniline, 4-bromo-3,5-dichloroaniline and 4-bromo-3-chloro-5-fluoroaniline, all of which are described in the literature and which can be reacted, for example, by a cross-coupling reaction generally known as the Sonogashira reaction (Scheme 1, where Z U1 -C≡C- and G is H), Suzuki coupling (where Z U1is -CH=CH-, -CF=CF-, -CH=CF- or -CF=CH-, and G is boronic acid or alkyl boronic ester group) and similar reactions thereof, and reacts with a suitable intermediate 1 to obtain a compound of formula UI. Reaction, wherein X and Y are leaving groups, or reaction with CS2 to obtain a compound of formula UI.

[0050] Scenario 1:

[0051]

[0052] A similar synthesis for structurally related compounds with trifluorovinyl substituents is shown in CN105294526 A, where compounds used as common components in display device media are disclosed. The compounds of formula UII shown below are prepared analogously or as described in EP 1 054 001 A1. Preferred reagents for the method according to the invention for converting compounds of formula N into compounds of formula UI are carbon disulfide, thiophosgene, thiocarbonyldiimidazole, di-2-pyridylthiocarbonate, bis(dimethylthiocarbamoyl)disulfide, dimethylaminothiocarbonyl chloride and phenylthiochloroformate, with thiophosgene being very preferred.

[0053] The reactions described should be regarded as illustrative only. A person skilled in the art can carry out corresponding variations of the syntheses described and also follow other suitable synthetic routes in order to obtain compounds of formula UI.

[0054] The compound of formula UI is preferably selected from the group of compounds consisting of formula UI-1, UI-2 and UI-3:

[0055]

[0056] Where R U , X U1 and X U2 has the meaning given above for formula UI, and wherein in formula UI-3, and At least one of the radicals represents trans-1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydronaphthalene-2,6-diyl, tetrahydronaphthalene-5,8-diyl, decahydronaphthalene-2,6-diyl, bicyclo[1.1.1]pentane-1,3-diyl, 4,4′-dicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl or spiro[3.3]heptane-2,6-diyl, wherein one or two CH groups may be replaced by N, one or more non-adjacent CH2 groups may be replaced by —O— and / or —S— and wherein one or more H atoms may be replaced by L, wherein

[0057] L, identically or differently on each occurrence, represents F, Cl, CN, SCN, SF5 or linear or branched, in each case optionally fluorinated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, each having 1 to 12 C atoms,

[0058] And preferably,

[0059] X U1 and X U2 Indicates F, R U preferably represents a straight-chain or branched or cyclic alkyl or alkenyl group having 1 to 7 C atoms, or a fluorinated alkyl or fluorinated alkoxy group having 1 to 7 C atoms, and

[0060] Preferably the same or different

[0061] Where R L represents, identically or differently on each occurrence, H or alkyl having 1 to 6 C atoms or represents One or more H atoms may be replaced by an alkyl group having 1 to 6 C atoms or by F. Very preferred

[0062] Preferred representation

[0063] More preferred Very preferred

[0064] in

[0065] R L represents H or an alkyl group having 1 to 6 C atoms.

[0066] Preferred compounds of formula UI are selected from the following sub-formulae:

[0067]

[0068]

[0069] Where R U has the meanings given above and preferably denotes straight-chain or branched alkyl having 1 to 7 C atoms, in particular methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl or n-heptyl.

[0070] The liquid-crystalline media according to the invention preferably comprise one or more compounds of the formula UI and further one or more compounds of the formula UII,

[0071]

[0072] in

[0073] R U represents H, straight-chain or branched alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms, wherein one or more CH2-groups may be replaced by substitution, wherein one or more non-adjacent CH2-groups may be replaced by: O, or a group R P ,

[0074] R P Indicates halogen, CN, NCS, R F -、R F -O- or R F -S-, where

[0075] R F represents a fluorinated alkyl or fluorinated alkenyl group having up to 9 C atoms,

[0076] Z U1 , Z U2 represent, identically or differently, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -C≡CC≡C- or a single bond, preferably -CF=CF-, -C≡C- or a single bond, very preferably -C≡C- or a single bond,

[0077] X U1 , X U2 Identically or differently represent Cl or F, preferably F,

[0078] and represents a group selected from the following group:

[0079] a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L,

[0080] b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydronaphthalene-2,6-diyl, tetrahydronaphthalene-5,8-diyl, decahydronaphthalene-2,6-diyl, bicyclo[1.1.1]pentane-1,3-diyl, 4,4'-dicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl and spiro[3.3]heptane-2,6-diyl, in which one or two CH groups may be replaced by N, one or more non-adjacent CH2 groups may be replaced by -O- and / or -S-, and in which one or more H atoms may be replaced by L,

[0081] c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may also be mono- or poly-substituted by L,

[0082] L, identically or differently on each occurrence, represents F, Cl, CN, SCN, SF5 or linear or branched, in each case optionally fluorinated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, each having 1 to 12 C atoms, and

[0083] u is 0, 1 or 2, preferably 1,

[0084] The compound of formula UI is not included in the compound of formula UII.

[0085] Preferably, the compound of formula UII is selected from the group consisting of compounds of formula UII-1, UII-2 and UII-3, preferably UII-1 and UII-2, especially UII-1:

[0086]

[0087] The radicals occurring therein have the meanings given above for formula UII and are preferably

[0088] and Same or different

[0089]

[0090] X U1 and X U2 Indicates F, R U Preferably it represents a straight-chain or branched or cyclic alkyl or alkenyl group having 1 to 7 C atoms, or a fluorinated alkyl or fluorinated alkoxy group having 1 to 7 C atoms.

[0091] Very preferred compounds of formula UII are selected from the following sub-formulae:

[0092]

[0093]

[0094] Where R U has the meanings given above and preferably denotes straight-chain or branched alkyl having 1 to 7 C atoms, in particular methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl or n-heptyl.

[0095] In a preferred embodiment, the medium according to the invention comprises one or more compounds selected from the group consisting of formulae I, II and III:

[0096]

[0097] in

[0098] R 1 represents H; unfluorinated alkyl or unfluorinated alkoxy having 1 to 17, preferably 2 to 10 C atoms; or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15, preferably 3 to 10 C atoms, wherein one or more CH2- groups may be or Instead, preferably an unfluorinated alkyl or unfluorinated alkenyl,

[0099] n is 0, 1, or 2,

[0100] to

[0101] In each occurrence, they are expressed independently of each other

[0102]

[0103] Where R L Indicate H the same or different on each occurrence

[0104] or an alkyl radical having 1 to 6 C atoms, preferably H,

[0105] Methyl or ethyl, particularly preferably H,

[0106]

[0107] One or more H atoms may have 1 to 6 C

[0108] Alkyl or F substitution of atoms,

[0109] And among them

[0110] Alternatively,

[0111]

[0112] Best

[0113]

[0114] And when n=2, One of the preferred representations and the other preferably represents

[0115]

[0116] Best

[0117] to

[0118] Independently express

[0119]

[0120] More preferred

[0121] express

[0122] express

[0123] express

[0124] R 2 represents H; unfluorinated alkyl or unfluorinated alkoxy having 1 to 17, preferably 2 to 10 C atoms; or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15, preferably 3 to 10 C atoms, wherein one or more CH2- groups may be Instead, preferably an unfluorinated alkyl or unfluorinated alkenyl,

[0125] Z 21 represents trans-CH=CH-, trans-CF=CF- or -C≡C-, preferably -C≡C- or trans-CH=CH-, and

[0126] and

[0127] Independently express

[0128]

[0129]

[0130] Where R L represents, identically or differently on each occurrence, H or alkyl having 1 to 6 C atoms, preferably H, methyl or ethyl, particularly preferably H,

[0131]

[0132] One or more H atoms may have 1 to 6 C

[0133] Alkyl or F substitution of atoms,

[0134] Best

[0135] and

[0136] Independently express

[0137]

[0138] Preferred representation

[0139] and

[0140] Preferred representation

[0141]

[0142] More preferred

[0143]

[0144] R 3 represents H; unfluorinated alkyl or unfluorinated alkoxy having 1 to 17, preferably 2 to 10 C atoms; or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15, preferably 3 to 10 C atoms, wherein one or more CH2- groups may be or Instead,

[0145] Preferably, it is an unfluorinated alkyl group or an unfluorinated alkenyl group,

[0146] Z 31 and Z 32 One of, preferably Z 32represents trans-CH=CH-, trans-CF=CF- or -C≡C-, and the other of them independently represents -C≡C-, trans-CH=CH-, trans-CF=CF- or a single bond, preferably one of them, preferably Z 32 represents -C≡C- or trans-CH=CH-, and the other represents a single bond, and

[0147]

[0148] to

[0149] Independently express

[0150]

[0151]

[0152] Where R L represents, identically or differently on each occurrence, H or alkyl having 1 to 6 C atoms, preferably H, methyl or ethyl, particularly preferably H,

[0153]

[0154] One or more H atoms may have 1 to 6 C

[0155] atom is substituted with an alkyl group or F, and wherein

[0156] Alternatively,

[0157]

[0158] Best

[0159] to

[0160] Independently express

[0161]

[0162] More preferred

[0163] express

[0164] express

[0165] In particular

[0166] express

[0167] In particular

[0168] In the compounds of formula I, formula II and formula III, R L Preferably it represents H.

[0169] In another preferred embodiment, in the compounds of formula I, II and III, one or two radicals R L , preferably a group R L Different from H.

[0170] In a preferred embodiment of the present invention, the compound of formula I is selected from the group consisting of compounds of formula I-1 to formula I-5:

[0171]

[0172]

[0173]

[0174] in

[0175] L 1 , L 2 and L 3 represents H or F in the same or different manner on each occurrence, and

[0176] The other groups have the corresponding meanings indicated above for formula I, and

[0177] Preferably

[0178] R 1 represents an unfluorinated alkyl group having 1 to 7 C atoms or an unfluorinated alkenyl group having 2 to 7 C atoms.

[0179] Preferably, the medium comprises one or more compounds selected from the compounds of formula I-1 and optionally one or more compounds selected from the compounds of formula Cy-1,

[0180]

[0181] The radicals occurring therein have the meanings given above for formula I-1. The total amount of compounds of formula I-1 and / or Cy-I in the medium according to the invention is less than 10%, more preferably less than 5% and in particular less than 2%. Particularly preferably, the medium contains no compounds of formula Cy-1.

[0182] The medium preferably comprises one or more compounds of the formula I-1, which are preferably selected from the group of compounds of the formulae I-1a to I-1d, preferably the group of compounds of the formula I-1b:

[0183]

[0184]

[0185] Where R 1 has the meanings indicated above for formula I and preferably denotes unfluorinated alkyl having 1 to 7 C atoms or unfluorinated alkenyl having 2 to 7 C atoms.

[0186] The medium preferably comprises one or more compounds of the formula I-2, which are preferably selected from the group of compounds of the formulae I-2a to I-2e, preferably the group of compounds of the formula I-2c:

[0187]

[0188] Where R 1 has the meanings indicated above for formula I and preferably denotes unfluorinated alkyl having 1 to 7 C atoms or unfluorinated alkenyl having 2 to 7 C atoms.

[0189] The medium preferably comprises one or more compounds of the formula I-3, which are preferably selected from the group of compounds of the formulae I-3a to I-3d, particularly preferably compounds of the formula I-3b:

[0190]

[0191] Where R 1 has the meanings indicated above for formula I and preferably denotes unfluorinated alkyl having 1 to 7 C atoms or unfluorinated alkenyl having 2 to 7 C atoms.

[0192] The medium preferably comprises one or more compounds of the formula I-4, which are preferably selected from the group of compounds of the formulae I-4a to I-4e, particularly preferably the group of compounds of the formula I-4b:

[0193]

[0194]

[0195] Where R 1 has the meanings indicated above for formula I and preferably denotes unfluorinated alkyl having 1 to 7 C atoms or unfluorinated alkenyl having 2 to 7 C atoms.

[0196] The medium preferably comprises one or more compounds of the formula I-5, which are preferably selected from the group of compounds of the formulae I-5a to I-5d, particularly preferably compounds of the formula I-5b:

[0197]

[0198] Where R1 has the meanings indicated above for formula I and preferably denotes unfluorinated alkyl having 1 to 7 C atoms or unfluorinated alkenyl having 2 to 7 C atoms.

[0199] The medium preferably comprises one or more compounds of formula II, which are preferably selected from the group of compounds of formulae II-1 to II-3, preferably from the group of compounds of formulae II-1 and II-2:

[0200]

[0201]

[0202] The radicals occurring therein have the meanings given above under formula II, and

[0203] Preferably R 2 represents a non-fluorinated alkyl or alkoxy group having 1 to 7 C atoms or a non-fluorinated alkenyl group having 2 to 7 C atoms, and

[0204] and One of them said

[0205]

[0206] and the other independently expresses

[0207]

[0208] Preferably

[0209]

[0210] Most preferably

[0211]

[0212] And preferably,

[0213] R 2 Represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0214] n represents an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0215] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0216] The compound of formula II-1 is preferably selected from the group of compounds of formulae II-1a to II-1e:

[0217]

[0218] in

[0219] R 2 has the meaning indicated above and preferably means C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0220] n represents an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0221] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0222] The compound of formula II-2 is preferably selected from the group of compounds of formula II-2a to formula II-2b:

[0223]

[0224] in

[0225] R 2 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,

[0226] n represents an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0227] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0228] The compound of formula II-3 is preferably selected from the group of compounds of formulae II-3a to II-3d:

[0229]

[0230] in

[0231] R 2 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,

[0232] n represents an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0233] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0234] The compound of formula III is preferably selected from the group of compounds of formulae III-1 to III-6, more preferably selected from the group of formulae III-1, III-2, III-3 and III-4, and particularly preferably the compound of formula III-1:

[0235]

[0236] in

[0237] Z 31 and Z 32 represents, independently of each other, trans-CH=CH- or trans-CF=CF-, preferably trans-CH=CH-, and in formula III-6, alternatively, Z 31 and Z 32 One of them may represent -C≡C- and the other group has the meaning given under formula III,

[0238] And preferably,

[0239] R 3 represents a non-fluorinated alkyl or alkoxy group having 1 to 7 C atoms or a non-fluorinated alkenyl group having 2 to 7 C atoms, and

[0240] to One of the following, preferably express

[0241]

[0242] Very preferably

[0243]

[0244] And the others are expressed independently of each other

[0245]

[0246] Preferably

[0247]

[0248] More preferably

[0249]

[0250] in

[0251] Alternatively,

[0252] And preferably,

[0253] R 3 Represents C n H 2n+1or CH2=CH-(CH2) Z ,

[0254] n represents an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0255] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0256] The compound of formula III-1 is preferably selected from the group of compounds of formulae III-1a to III-1j, more preferably selected from the group of compounds of formulae III-1a, III-1b, III-1g and III-1h, and particularly preferably selected from the group of compounds of formulae III-1b and / or III-1h:

[0257]

[0258]

[0259] in

[0260] R 3 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,

[0261] n represents an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0262] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0263] The compound of formula III-2 is preferably a compound of formula III-2a to III-21, very preferably III-2b and / or III-2j:

[0264]

[0265]

[0266]

[0267] in

[0268] R 3 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,

[0269] n represents an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0270] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0271] The compound of formula III-5 is preferably selected from the compounds of formula III-5a:

[0272]

[0273] R 3 has the meaning indicated above for formula III-5 and preferably represents C n H 2n+1 ,in

[0274] n represents an integer in the range of 1-7, preferably in the range of 2-6.

[0275] In a preferred embodiment, the medium according to the invention comprises one or more compounds selected from the group consisting of the compounds of the formula IIA-1-1 to IIA-1-12, very preferably compounds of IIA-1-1 or IIA-1-2:

[0276]

[0277]

[0278]

[0279] in

[0280] R 1 denotes an alkyl or alkenyl group having up to 7 C atoms, preferably ethyl, n-propyl, n-butyl or n-pentyl, n-hexyl,

[0281] R L represents, identically or differently on each occurrence, alkyl or alkenyl having 1 to 5 C atoms or cycloalkyl or cycloalkenyl having in each case 3 to 6 C atoms,

[0282] preferably methyl, ethyl, n-propyl, n-butyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclopent-1-enyl, very preferably ethyl,

[0283] And the compound of formula II-1 is not included therein.

[0284] Furthermore, in a certain embodiment, the liquid-crystalline medium according to the invention, which may be the same as or different from the previously preferred embodiments, preferably comprises one or more compounds of the formula IV,

[0285]

[0286] in

[0287]

[0288] express

[0289]

[0290] s is 0 or 1, preferably 1, and preferably

[0291] express

[0292]

[0293] Particularly preferably

[0294]

[0295] L 4 represents H or alkyl having 1 to 6 C atoms, cycloalkyl having 3 to 6 C atoms or cycloalkenyl having 4 to 6 C atoms, preferably CH3, C2H5, n-C3H7, i-C3H7, cyclopropyl, cyclobutyl, cyclohexyl, cyclopent-1-enyl or cyclohex-1-enyl, and particularly preferably CH3, C2H5, cyclopropyl or cyclobutyl,

[0296] X 4 denotes H, alkyl having 1 to 3 C atoms or halogen, preferably H, F or Cl, more preferably H or F and very especially preferably F,

[0297] R 41 To R 44 , independently of one another represent non-fluorinated alkyl or non-fluorinated alkoxy groups each having 1 to 15 C atoms, non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl groups each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl groups each having up to 15 C atoms, and alternatively R 43 and R 44 One or both of them also represent H,

[0298] Preferably

[0299] R 41 and R 42 , independently of one another represent a non-fluorinated alkyl or non-fluorinated alkoxy group each having 1 to 7 C atoms, or a non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl group each having 2 to 6 C atoms,

[0300] Particularly preferably

[0301] R 41 represents a non-fluorinated alkyl group having 1 to 7 C atoms or a non-fluorinated alkenyl group, a non-fluorinated alkenyloxy group or a non-fluorinated alkoxyalkyl group having 2 to 6 C atoms, and

[0302] Particularly preferably

[0303] R 42 represents a non-fluorinated alkyl or non-fluorinated alkoxy group each having 1 to 7 C atoms, and

[0304] Preferably

[0305] R 43 and R 44 represents H, non-fluorinated alkyl having 1 to 5 C atoms, non-fluorinated cycloalkyl or cycloalkenyl having 3 to 7 C atoms, non-fluorinated alkylcyclohexyl or non-fluorinated cyclohexylalkyl having 4 to 12 C atoms or non-fluorinated alkylcyclohexylalkyl having 5 to 15 C atoms, particularly preferably cyclopropyl, cyclobutyl or cyclohexyl, and very particularly preferably, R 43 and R 44 At least one of them represents n-alkyl, particularly preferably methyl, ethyl or n-propyl, and the other represents H or n-alkyl, particularly preferably H, methyl, ethyl or n-propyl.

[0306] Very preferably, the compound of formula IV is selected from the compounds of formula IV-1,

[0307]

[0308] Where R 41 and R 42 Identically or differently represent alkyl radicals having 2, 3, 4, 5 or 6 C atoms.

[0309] In a preferred embodiment of the present invention, the liquid-crystalline medium further comprises one or more compounds selected from the group consisting of compounds of the formula V, formula VI, formula VII, formula VIII and formula IX:

[0310]

[0311]

[0312] in

[0313] L 51 Represents R 51 or X 51 ,

[0314] L 52 Represents R 52 or X 52 ,

[0315] R 51 and R 52, independently of one another represent H, non-fluorinated alkyl or non-fluorinated alkoxy having 1-17, preferably 2-10 C atoms, or non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl having 2-15, preferably 3-10 C atoms, preferably alkyl or non-fluorinated alkenyl,

[0316] X 51 and X 52 , independently of one another represent H, F, Cl, -CN, SF5, a fluorinated alkyl group or a fluorinated alkoxy group having 1 to 7 C atoms, or a fluorinated alkenyl group, a fluorinated alkenyloxy group or a fluorinated alkoxyalkyl group having 2 to 7 C atoms, preferably a fluorinated alkoxy group, a fluorinated alkenyloxy group, F or Cl, and

[0317]

[0318] to

[0319] Independently express

[0320]

[0321] Preferably

[0322]

[0323] L 61 Represents R 61 and in Z 61 and / or Z 62 When trans-CH=CH- or trans-CF=CF- is represented, X is also represented alternatively. 61 ,

[0324] L 62 Represents R 62 and in Z 61 and / or Z 62 When trans-CH=CH- or trans-CF=CF- is represented, X is also represented alternatively. 62 ,

[0325] R 61 and R 62 , independently of one another represent H, non-fluorinated alkyl or non-fluorinated alkoxy having 1-17, preferably 2-10 C atoms, or non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl having 2-15, preferably 3-10 C atoms, preferably alkyl or non-fluorinated alkenyl,

[0326] X 61 and X 62, independently of one another represent F or Cl, -CN, SF5, a fluorinated alkyl or alkoxy group having 1 to 7 C atoms or a fluorinated alkenyl, alkenyloxy or alkoxyalkyl group having 2 to 7 C atoms,

[0327] Z 61 and Z 62 one of them represents trans-CH=CH-, trans-CF=CF- or -C≡C- and the other independently thereof represents trans-CH=CH-, trans-CF=CF- or a single bond, preferably one of them represents -C≡C- or trans-CH=CH- and the other represents a single bond, and

[0328]

[0329] to

[0330] Independently express

[0331]

[0332]

[0333] Preferably

[0334]

[0335] and

[0336] x represents 0 or 1;

[0337] L 71 Represents R 71 or X 71 ,

[0338] L 72 Represents R 72 or X 72 ,

[0339] R 71 and R 72 , independently of one another represent H, non-fluorinated alkyl or non-fluorinated alkoxy having 1-17, preferably 2-10 C atoms, or non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl having 2-15, preferably 3-10 C atoms, preferably alkyl or non-fluorinated alkenyl,

[0340] X 71 and X 72, independently of one another represent H, F, Cl, -CN, -NCS, -SF5, a fluorinated alkyl group or a fluorinated alkoxy group having 1 to 7 C atoms or a fluorinated alkenyl group having 2 to 7 C atoms, a non-fluorinated or fluorinated alkenyloxy group or a non-fluorinated or fluorinated alkoxyalkyl group, preferably a fluorinated alkoxy group, a fluorinated alkenyloxy group, F or Cl, and

[0341] Z 71 To Z 73 , independently represent trans-CH=CH-, trans-CF=CF-, -C≡C- or a single bond, preferably one or more of them represent a single bond, and particularly preferably all of them represent a single bond and

[0342] to

[0343] Independently express

[0344]

[0345]

[0346] Best

[0347]

[0348] R 81 and R 82 , independently of one another, represent H; unfluorinated alkyl or alkoxy having 1 to 15, preferably 2 to 10 C atoms; or unfluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15, preferably 3 to 10 C atoms, preferably unfluorinated alkyl or alkenyl,

[0349] Z 81 and Z 82 One of them represents trans-CH=CH-, trans-CF=CF- or -C≡C- and the other independently thereof represents trans-CH=CH-, trans-CF=CF- or a single bond, preferably, one of them represents -C≡C- or trans-CH=CH- and the other represents a single bond, and

[0350] express

[0351]

[0352] and

[0353] Independently express

[0354]

[0355]

[0356] L 91 Represents R 91 or X 91 ,

[0357] L 92 Represents R 92 or X 92 ,

[0358] R 91 and R 92 , independently of one another represent H, non-fluorinated alkyl or alkoxy having 1-15, preferably 2-10 C atoms, or non-fluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2-15, preferably 3-10 C atoms, preferably non-fluorinated alkyl or alkenyl,

[0359] X 91 and X 92 , independently of one another represent H, F, Cl, -CN, -NCS, -SF5, a fluorinated alkyl group or a fluorinated alkoxy group having 1 to 7 C atoms or a fluorinated alkenyl group having 2 to 7 C atoms, a non-fluorinated or fluorinated alkenyloxy group or a non-fluorinated or fluorinated alkoxyalkyl group, preferably a fluorinated alkoxy group, a fluorinated alkenyloxy group, F or Cl, and

[0360] Z 91 To Z 93 , independently of one another represent trans-CH=CH-, trans-CF=CF-, -C≡C- or a single bond, preferably one or more of them represent a single bond, and particularly preferably all represent a single bond,

[0361] express

[0362] to

[0363] Independently express

[0364]

[0365]

[0366] In a preferred embodiment of the present invention, the liquid-crystalline medium comprises one or more compounds of the formula V, preferably selected from the compounds of the formulae V-1 to V-3, preferably compounds of the formulae V-1 and / or V-2 and / or V-3, preferably compounds of the formulae V-1 and V-2:

[0367]

[0368] The radicals occurring therein have the corresponding meanings indicated above for formula V and are preferably

[0369] R 51 represents a non-fluorinated alkyl group having 1 to 7 C atoms or a non-fluorinated alkenyl group having 2 to 7 C atoms,

[0370] R 52 represents a non-fluorinated alkyl group having 1 to 7 C atoms or a non-fluorinated alkenyl group having 2 to 7 C atoms or a non-fluorinated alkoxy group having 1 to 7 C atoms,

[0371] X 51 and X 52 , independently represent F, Cl, -OCF3, -CF3, -CN or -SF5, preferably F, Cl, -OCF3 or -CN.

[0372] The compound of formula V-1 is preferably selected from the compounds of formulae V-1a to V-1d, preferably V-1c and V-1d:

[0373]

[0374]

[0375] wherein the parameters have the corresponding meanings indicated above for formula V-1 and wherein

[0376] Y 51 and Y 52 , independently of each other in each case represents H or F, and preferably

[0377] R 51 represents an alkyl or alkenyl group, and

[0378] X 51 It represents F, Cl or -OCF3.

[0379] The compound of formula V-2 is preferably selected from the compounds of formulae V-2a to V-2e and / or from the compounds of formulae V-2f and V-2g:

[0380]

[0381]

[0382] wherein in each case the compound of formula V-2a is not included in the compounds of formulae V-2b and V-2c, the compound of formula V-2b is not included in the compounds of formula V-2c and the compound of formula V-2f is not included in the compounds of formula V-2g, and

[0383] wherein the parameters have the corresponding meanings indicated above for formula V-1 and wherein

[0384] Y 51 and Y 52 , independently of one another in each case represent H or F, and preferably

[0385] Y 51 and Y 52 represents H and the other represents H or F, preferably both represent H.

[0386] The compound of formula V-3 is preferably a compound of formula V-3a:

[0387]

[0388] wherein the parameters have the corresponding meanings indicated above for formula V-1 and wherein preferably

[0389] X 51 represents F, Cl, preferably F,

[0390] X 52 It represents F, Cl or -OCF3, preferably -OCF3.

[0391] The compound of formula V-1a is preferably selected from the compounds of formula V-1a-1 and V-1a-2

[0392]

[0393]

[0394] in

[0395] R 51 has the meaning indicated above and preferably represents C n H 2n+1 ,in

[0396] n represents an integer in the range of 1-7, preferably in the range of 1-6 and particularly preferably in the range of 3-5.

[0397] The compound of formula V-1b is preferably a compound of formula V-1b-1:

[0398]

[0399] in

[0400] R 51 has the meaning indicated above, and preferably represents C n H 2n+1 ,in

[0401] n represents an integer in the range of 1-7, preferably in the range of 1-6 and particularly preferably in the range of 3-5.

[0402] The compound of formula V-1c is preferably selected from the group of compounds of formula V-1c-1 to formula V-1c-4, particularly preferably selected from the group of compounds of formula V-1c-1 and formula V-1c-2:

[0403]

[0404] in

[0405] R 51 has the meaning indicated above, and preferably represents C n H 2n+1 ,in

[0406] n represents an integer in the range of 1-7, preferably in the range of 1-6 and particularly preferably in the range of 3-5.

[0407] The compound of formula V-1d is preferably selected from the group of compounds of formula V-1d-1 and V-1d-2, and is particularly preferably a compound of formula V-1d-2:

[0408]

[0409] in

[0410] R 51 has the meaning indicated above, and preferably represents C n H 2n+1 ,in

[0411] n represents an integer in the range of 1-7, preferably in the range of 1-6 and particularly preferably in the range of 3-5.

[0412] The compound of formula V-2a is preferably selected from the group of compounds of formula V-2a-1 and V-2a-2, and is particularly preferably a compound of formula V-2a-1:

[0413]

[0414] in

[0415] R 51 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0416] R 52 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0417] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 1 to 6 and particularly preferably in the range of 3 to 5, and

[0418] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0419] R 51 With R 52 A preferred combination, especially in the case of formula V-2a-1 is (C n H 2n+1 With C m H 2m+1 )、(C n H 2n+1 With OC m H 2m+1 )、(CH2=CH-(CH2) Z With C m H 2m+1 )、(CH2=CH-(CH2) Z With OC m H 2m+1 ) and (C n H 2n+1 With (CH2) Z -CH=CH2).

[0420] Preferred compounds of formula V-2b are compounds of formula V-2b-1:

[0421]

[0422] in

[0423] R 51 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0424] R 52 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0425] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 1 to 6 and particularly preferably in the range of 3 to 5, and

[0426] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0427] R 51 With R 52The preferred combination here is especially C n H 2n+1 With C m H 2m+1 .

[0428] Preferably, the compound of formula V-2c is a compound of formula V-2c-1:

[0429]

[0430] in

[0431] R 51 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0432] R 52 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0433] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 1 to 6 and particularly preferably in the range of 3 to 5, and

[0434] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0435] In particular, here (R 51 With R 52 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ).

[0436] Preferably, the compound of formula V-2d is a compound of formula V-2d-1:

[0437]

[0438] in

[0439] R 51 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0440] R 52 has the meaning indicated above, and preferably represents C m H 2m+1 or OCm H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0441] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 1 to 6 and particularly preferably in the range of 3 to 5, and

[0442] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0443] In particular, here (R 51 With R 52 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ).

[0444] Preferably, the compound of formula V-2e is a compound of formula V-2e-1:

[0445]

[0446] in

[0447] R 51 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0448] R 52 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0449] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0450] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0451] In particular, here (R 51 With R 52 The preferred combination of ) is (C n H 2n+1 With OC m H 2m+1 ).

[0452] Preferred compounds of formula V-2f are compounds of formula V-2f-1:

[0453]

[0454] in

[0455] R 51 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0456] R 52 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0457] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0458] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0459] In particular, here (R 51 With R 52 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), particularly preferably (C n H 2n+1 With C m H 2m+1 ).

[0460] Preferably, the compound of formula V-2g is a compound of formula V-2g-1:

[0461]

[0462] in

[0463] R 51 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0464] R 52 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1or (CH2) Z -CH=CH2, and wherein

[0465] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0466] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0467] In particular, here (R 51 With R 52 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), particularly preferably (C n H 2n+1 With OC m H 2m+1 ).

[0468] The compound of formula VI is preferably selected from the group of compounds of formulae VI-1 to VI-5:

[0469]

[0470]

[0471] in

[0472] Z 61 and Z 62 represents -C≡C-, trans-CH=CH- or trans-CF=CF-, preferably -C≡C- or trans-CH=CH-, and the other groups and parameters occurring have the meanings given above under formula VI,

[0473] And preferably,

[0474] R 61 and R 62 , independently of one another represent H, unfluorinated alkyl or alkoxy having 1 to 7 C atoms or unfluorinated alkenyl having 2 to 7 C atoms,

[0475] X 62 represents F, Cl, -OCF3 or -CN,

[0476] The compound of formula VI-1 is preferably selected from the group of compounds of formula VI-1a and VI-1b, more preferably selected from the group of compounds of formula VI-1a:

[0477]

[0478] in

[0479] R 61 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0480] R 62 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0481] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0482] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0483] In particular, here (R 61 and R 62 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), in the case of formula VI-1a, particularly preferably (C n H 2n+1 With C m H 2m+1 ), and in the case of Formula VI-1b, it is particularly preferred that (C n H 2n+1 With OC m H 2m+1 ).

[0484] The compound of formula VI-3 is preferably selected from the compounds of formula VI-3a to VI-3e:

[0485]

[0486] wherein the parameters have the meanings given above under formula VI-3, and preferably

[0487] R 61 has the meaning indicated above, and preferably represents C n H 2n+1 ,in

[0488] n represents an integer in the range of 1 to 7, preferably in the range of 1 to 5, and

[0489] X 62 It represents -F, -Cl, -OCF3 or -CN.

[0490] The compound of formula VI-4 is preferably selected from the compounds of formula VI-4a to VI-4e:

[0491]

[0492]

[0493] wherein the parameters have the meanings given above under formula VI-4, and preferably

[0494] R 61 has the meaning indicated above, and preferably represents C n H 2n+1 ,in

[0495] n represents an integer in the range of 1 to 7, preferably in the range of 1 to 5, and

[0496] X 62 It represents F, Cl, OCF3 or -CN.

[0497] The compound of formula VI-5 is preferably selected from the group consisting of formula VI-5a to formula VI-5d, preferably compound VI-5b:

[0498]

[0499]

[0500] wherein the parameters have the meanings given above under formula VI-5, and preferably R 61 has the meaning indicated above, and preferably represents C n H 2n+1 , wherein n represents an integer in the range of 1 to 7, preferably in the range of 1 to 5, and X 62 It represents -F, -Cl, -OCF3 or -CN, and is particularly preferably -OCF3.

[0501] The compound of formula VII is preferably selected from the group of compounds of formulae VII-1 to VII-6:

[0502]

[0503] wherein the compound of formula VII-5 is not included in the compound of formula VII-6, and

[0504] wherein the parameters have the corresponding meanings indicated above for formula VII,

[0505] Y 71 , Y 72 , Y 73 independently of each other represent H or F,

[0506] And preferably,

[0507] R 71 represents an unfluorinated alkyl or alkoxy group each having 1 to 7 C atoms, or an unfluorinated alkenyl group having 2 to 7 C atoms,

[0508] R 72 represents an unfluorinated alkyl or alkoxy group each having 1 to 7 C atoms, or an unfluorinated alkenyl group having 2 to 7 C atoms,

[0509] X 72 represents F, Cl; NCS or -OCF3, preferably F or NCS, and

[0510] Particularly preferably

[0511] R 71 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0512] R 72 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0513] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0514] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0515] The compound of formula VII-1 is preferably selected from the group of compounds of formulae VII-1a to VII-1d:

[0516]

[0517]

[0518] Where X 72 has the meaning given above for Formula VII-2, and

[0519] R 71 has the meaning indicated above, and preferably represents Cn H 2n+1 ,in

[0520] n represents an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0521] z represents 0, 1, 2, 3 or 4, preferably 0 or 2, and

[0522] X 72 Preferably it represents F.

[0523] The compound of formula VII-2 is preferably selected from the group consisting of formula VII-2a and formula VII-2b, particularly preferably the group consisting of compounds of formula VII-2a:

[0524]

[0525] in

[0526] R 71 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0527] R 72 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0528] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0529] In particular, here (R 71 With R 72 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), particularly preferably (C n H 2n+1 With C m H 2m+1 ).

[0530] The compound of formula VII-3 is preferably a compound of formula VII-3a:

[0531]

[0532] in

[0533] R 71 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0534] R 72 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0535] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0536] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0537] In particular, here (R 71 With R 72 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), particularly preferably (C n H 2n+1 With C m H 2m+1 ).

[0538] The compound of formula VII-4 is preferably a compound of formula VII-4a:

[0539]

[0540] in

[0541] R 71 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0542] R 72 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H2m+1 or (CH2) Z -CH=CH2, and wherein

[0543] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0544] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0545] In particular, here (R 71 With R 72 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), particularly preferably (C n H 2n+1 With C m H 2m+1 ).

[0546] The compound of formula VII-5 is preferably selected from the group consisting of formula VII-5a and VII-5b, more preferably the group consisting of formula VII-5a:

[0547]

[0548]

[0549] in

[0550] R 71 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0551] R 72 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0552] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0553] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0554] In particular, here (R 71With R 72 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), particularly preferably (C n H 2n+1 With C m H 2m+1 ).

[0555] The compound of formula VII-6 is preferably selected from the group consisting of compounds of formula VII-6a and formula VII-6b:

[0556]

[0557] in

[0558] R 71 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0559] R 72 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0560] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0561] In particular, here (R 71 With R 72 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), particularly preferably (C n H 2n+1 With C m H 2m+1 ).

[0562] The compound of formula VII-7 is preferably selected from the group of compounds of formula VII-7a to formula VII-7d:

[0563]

[0564] in

[0565] R 71 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,

[0566] X 72 Indicates F, -OCF3 or -NCS,

[0567] n represents an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0568] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0569] The compound of formula VIII is preferably selected from the group of compounds of formulae VIII-1 to VIII-3, more preferably, these compounds of formula VIII consist essentially of, even more preferably essentially of and very especially preferably completely of:

[0570]

[0571]

[0572] where Y 81 and Y 82 One of represents H and the other represents H or F, and

[0573] R 81 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0574] R 82 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0575] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0576] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0577] In particular, here (R 81 With R 82 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), particularly preferably (C n H 2n+1 With C m H 2m+1 ).

[0578] The compound of formula VIII-1 is preferably selected from the group of compounds of formulae VIII-1a to VIII-1c:

[0579]

[0580] in

[0581] R 81 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0582] R 82 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0583] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0584] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0585] In particular, here (R 81 With R 82 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), particularly preferably (C n H 2n+1 With C m H 2m+1 ).

[0586] The compound of formula VIII-2 is preferably a compound of formula VIII-2a:

[0587]

[0588] in

[0589] R 81 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0590] R 82 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0591] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0592] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0593] In particular, here (R 81 With R 82 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 )、(C n H 2n+1 With OC m H 2m+1 ) and (CH2=CH-(CH2) Z With C m H 2m+1 ), particularly preferably (C n H 2n+1 With C m H 2m+1 ).

[0594] The compound of formula VIII-3 is preferably a compound of formula VIII-3a:

[0595]

[0596] in

[0597] R 81 has the meaning indicated above, and preferably represents C n H 2n+1or CH2=CH-(CH2) Z ,and

[0598] R 82 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0599] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0600] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0601] In particular, here (R 81 With R 82 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ).

[0602] The compound of formula IX is preferably selected from the group of compounds of formulae IX-1 to IX-3:

[0603]

[0604] wherein the parameters have the corresponding meanings indicated above under formula IX, and preferably

[0605] to one of

[0606] express

[0607] And among them

[0608] R 91 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0609] R 92 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z-CH=CH2, and wherein

[0610] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0611] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0612] In particular, here (R 91 With R 92 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ).

[0613] The compound of formula IX-1 is preferably selected from the group of compounds of formula IX-1a to formula IX-1e:

[0614]

[0615] wherein the parameters have the meanings given above and preferably

[0616] R 91 has the meaning indicated above, and preferably represents C n H 2n+1 ,and

[0617] n represents an integer in the range of 0 to 15, preferably in the range of 1 to 7 and particularly preferably in the range of 1 to 5, and

[0618] X 92 Preferably it represents F or Cl.

[0619] The compound of formula IX-2 is preferably selected from the group of compounds of formulae IX-2a to IX-2b:

[0620]

[0621] in

[0622] R 91 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0623] R 92 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1or (CH2) Z -CH=CH2, and wherein

[0624] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0625] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0626] In particular, here (R 91 With R 92 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ).

[0627] The compound of formula IX-3 is preferably a compound of formula IX-3a and IX-3b:

[0628]

[0629] in

[0630] R 91 has the meaning indicated above, and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0631] R 92 has the meaning indicated above, and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0632] n and m, independently of one another, represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 3 to 5, and

[0633] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0634] In particular, here (R 91 With R 92 The preferred combination of ) is (C n H 2n+1 With C m H 2m+1 ) and (C n H 2n+1 With OC m H 2m+1 ), particularly preferably (C n H 2n+1 With OCm H 2m+1 ).

[0635] In a preferred embodiment of the invention, the medium comprises one or more compounds of the formula X,

[0636]

[0637] in

[0638] R 101 represents H; alkyl or alkoxy having 1 to 15, preferably 2 to 10 C atoms; or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15, preferably 3 to 10 C atoms, preferably alkyl or alkenyl,

[0639] X 101 represents H, F, Cl, -CN, SF5, NCS, a fluorinated alkyl group or a fluorinated alkoxy group having 1 to 7 C atoms, or a fluorinated alkenyl group, a fluorinated alkenyloxy group or a fluorinated alkoxyalkyl group having 2 to 7 C atoms, preferably a fluorinated alkoxy group, a fluorinated alkenyloxy group, F, Cl or NCS, particularly preferably NCS,

[0640] Y 101 represents methyl, ethyl or Cl,

[0641] Y 102 represents H, methyl, ethyl, F or Cl, preferably H or F,

[0642] Z 101 , Z 102 represent, identically or differently, a single bond, -CH=CH-, -CF=CF- or -C≡C-,

[0643] and

[0644] Independently express

[0645]

[0646] Best

[0647]

[0648] And among them

[0649] Alternatively, and

[0650] n is 0 or 1.

[0651] Preferably, the compound of formula X is selected from sub-formula X-1 and sub-formula X-2

[0652]

[0653] The radicals and parameters occurring therein have the meanings given above for formula X.

[0654] Particularly preferably, the medium according to the invention comprises one or more compounds selected from the group of compounds of the formulae X-1-1 to X-1-9,

[0655]

[0656]

[0657] Where R 101 represents an alkyl group having 1 to 7 C atoms.

[0658] In a preferred embodiment, the medium according to the invention comprises one or more compounds of the formula XI,

[0659]

[0660] in

[0661] R S represents H, alkyl or alkoxy having 1 to 12 C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 12 C atoms, wherein one or more CH2- groups may be replaced by substituted, and one or more H atoms may be replaced by F,

[0662] and

[0663] In each occurrence, they are expressed independently of each other

[0664]

[0665]

[0666] Where R L Indicates H the same or differently on each occurrence,

[0667] Cl or a linear, branched or cyclic alkyl radical having 1 to 6 C atoms,

[0668] L S1 , L S2 represent H, Cl or F identically or differently,

[0669] R S1 , R S2 , identically or differently represent H, alkyl or alkenyl having up to 6 C atoms, or cyclopropyl, cyclobutyl, cyclopentenyl or cyclopentyl,

[0670] R Th1 , R Th2 represents, identically or differently, H, alkyl or alkenyl or alkoxy having up to 6 C atoms, or cyclopropyl, cyclobutyl, cyclopentenyl or cyclopentyl,

[0671] Z S1 , Z S2 , Z S3 represent, identically or differently, -CH=CH-, -CH=CF-, -CF=CH-, -CF=CF-, -C≡C- or a single bond,

[0672] a and b are the same or different and are 0 or 1.

[0673] Preferably, the compound of formula XI is selected from the group consisting of compounds of formula XI-1 to formula XI-24:

[0674]

[0675]

[0676]

[0677]

[0678] The radicals occurring therein have the meanings given above for formula XI and are preferably

[0679] R S represents an alkyl or alkenyl group having 2 to 6 C atoms, wherein one or more CH2-groups may be Instead,

[0680] R S1 and R S2 represent, identically or differently, H or an alkyl radical having 1 to 6 C atoms, preferably H,

[0681] R S3 denotes H, F or alkyl having up to 6 C atoms, or cyclopropyl, preferably H, F or ethyl, very preferably H,

[0682] L S1 and L S2 Identically or differently represents H or F, preferably F.

[0683] Preferably, the medium comprises one or more compounds of formula XII,

[0684]

[0685] in

[0686] R 12represents H, alkyl or alkoxy having 1 to 12 C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 12 C atoms, wherein one or more CH2- groups may be replaced by Replacement, or represents the group R P ,

[0687] R P Indicates halogen, CN, NCS, R F , R F -O- or R F -S-, where

[0688] R F represents a fluorinated alkyl or fluorinated alkenyl group having up to 9 C atoms,

[0689] Z 121 , Z 122 represent, identically or differently, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, preferably -C≡C- or a single bond,

[0690] X 1 , X 2 , X 3 and X 4 Identically or differently represent Cl or F, preferably F, t is 0 or 1, and

[0691] and

[0692] represents a group selected from the following group:

[0693] a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L, excluding tetrafluoro-1,4-phenylene,

[0694] b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, bicyclo[1.1.1]pentane-1,3-diyl, 4,4'-dicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, wherein one or more non-adjacent CH2 groups may be replaced by -O- and / or -S-, and wherein one or more H atoms may be replaced by F,

[0695] c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may also be mono- or poly-substituted by L,

[0696] L, identically or differently on each occurrence, represents F, Cl, CN, SCN, SF5 or linear or branched, in each case optionally fluorinated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms.

[0697] The compound of formula XII is preferably selected from the compounds of sub-formulae XII-1 to XII-11:

[0698]

[0699]

[0700] in

[0701] L 1 , L 2 and L 3 represents, identically or differently, H, F, Cl, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl, and

[0702] R 12 , X 1 , X 2 , X 3 and X 4 has the meaning given above.

[0703] Very preferably, the medium comprises a compound of the formula XII-3, in which the radicals occurring have the meanings given above, and especially preferably, L 1 Indicates H, X 1 , X 2 , X 3 and X 4 represents F, and R 12 represents an alkyl group having 1 to 7 C atoms.

[0704] The medium according to the invention preferably comprises one or more compounds of the formula XIII,

[0705]

[0706] in

[0707] R 13 represents H, alkyl or alkoxy having 1 to 12 C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 12 C atoms, wherein one or more CH2- groups may be replaced by Substitution, or group R P ,

[0708] R P Indicates halogen, CN, NCS, R F , R F -O- or RF -S-, where

[0709] R F represents a fluorinated alkyl or fluorinated alkenyl group having up to 9 C atoms,

[0710] Z 131 , Z 132 , Z 133 represent, identically or differently, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, preferably -C≡C- or a single bond,

[0711] X 1 , X 2 Identically or differently represent H, Cl, F, CH3 or C2H5, preferably H or F,

[0712] Y 1 , Y 2 , Y 3 , Y 4 represents, identically or differently, H, F, Cl or a linear or branched or cyclic alkyl, alkenyl, alkoxy or alkenyloxy radical each having up to 12 C atoms, wherein Y 1 , Y 2 , Y 3 and Y 4 At least one of is different from F,

[0713] s is 0, 1 or 2, preferably 0 or 1,

[0714] t is 0, 1 or 2, preferably 0 or 1, and

[0715] s+t is 0, 1 or 2, preferably 0 or 1,

[0716] and

[0717] represents a group selected from the following group:

[0718] a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L,

[0719] b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, bicyclo[1.1.1]pentane-1,3-diyl, 4,4'-dicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, wherein one or more non-adjacent CH2 groups may be replaced by -O- and / or -S-, and wherein one or more H atoms may be replaced by F,

[0720] c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may also be mono- or poly-substituted by L,

[0721] L, identically or differently on each occurrence, represents F, Cl, CN, SCN, SF5 or linear or branched, in each case optionally fluorinated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms.

[0722] In a preferred embodiment of the present invention, the compound of formula XIII is selected from the compounds of formulae XIII-1 to XIII-20, very preferably from the compounds of formulae XIII-1 to XIII-13:

[0723]

[0724]

[0725]

[0726]

[0727] The radicals occurring therein have the meanings indicated above for formula XIII and its subformulae, and preferably R 13 represents an alkyl group having 1 to 7 C atoms, Y 1 , Y 2 , Y 3 and Y 4 represents H, F, Cl, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl, and more preferably Y 1 and Y 2 independently represents H or F, especially H, and Y 3 and Y 4 Very preferably represents H, and L 1 and L 2 Very preferably, identically or differently, it represents H, F, methyl or ethyl, in particular H.

[0728] Preferably, the medium according to the invention comprises one or more compounds of formula T,

[0729]

[0730] in

[0731] R T Indicates halogen, CN, NCS, R F , R F -O- or R F -S-, where

[0732] R F represents a fluorinated alkyl or fluorinated alkenyl group having up to 12 C atoms,

[0733] and

[0734] In each occurrence, they are expressed independently of each other

[0735]

[0736]

[0737] L 4 and L 5 represents, identically or differently, F, Cl or a straight-chain, branched or cyclic alkyl or alkenyl group each having up to 12 C atoms;

[0738] Z T3 , Z T4 represent, identically or differently, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, and

[0739] t is 0 or 1.

[0740] In a preferred embodiment, the liquid-crystalline media according to the invention comprise one or more compounds selected from the group of compounds of the following formulae T-1a to T-3b:

[0741]

[0742] in

[0743] and has the meaning given above, and

[0744] n is 1, 2, 3, 4, 5, 6 or 7, preferably 1, 2, 3 or 4, particularly preferably 1.

[0745] In a particularly preferred embodiment of the invention, the medium comprises one or more compounds selected from the group consisting of compounds of the formula T-1a and formula T-2a.

[0746] Preferably, the compound of formula T-1a is selected from the group of compounds of the following sub-formulae:

[0747]

[0748] wherein n is 1, 2, 3 or 4, preferably 1.

[0749] Preferably, the compound of formula T-2a is selected from the group of compounds of the following sub-formulae:

[0750]

[0751]

[0752] wherein n is 1, 2, 3 or 4, preferably 1.

[0753] Very preferably, the medium according to the invention comprises one or more compounds of the formula T-1a-5.

[0754] In one embodiment, the medium according to the invention comprises one or more compounds of the formula I, II, III, IV, V, VI, VII, VIII, IX, X, in which the radical R 1 , R 2 , R 3 , R 41 , R 42 , R 51 , R 52 , R 61 , R 62 , R 71 , R 72 , R 81 , R 82 , R 91 , R 92 , R 101 , R 102 and R S are cycloalkyl groups respectively.

[0755] Highly preferred compounds containing a cycloalkyl group are selected from compounds of formula Cy-1 to Cy-14,

[0756]

[0757]

[0758]

[0759] The medium according to the invention comprises one or more chiral dopants. Preferably, the absolute value of the helical twisting power (HTP) of these chiral dopants is between 1 μm -1 Up to 150μm -1 In the range of 10 μm, preferably -1 Up to 100 μm -1In the case where the medium contains two or more chiral dopants, these may have opposite signs of their HTP values. For some specific embodiments, this condition is preferred because it allows to compensate the chirality of the corresponding compounds to a certain extent and can therefore be used to compensate for various temperature-dependent properties of the resulting medium in the device. However, in general, it is preferred that most of the chiral compounds, preferably all of the chiral compounds present in the medium according to the invention have the same sign of their HTP values.

[0760] Preferably, the chiral dopants present in the medium according to the present application are mesogenic compounds and most preferably they themselves exhibit a mesogenic phase.

[0761] In a preferred embodiment of the invention, the medium comprises two or more chiral compounds which all have the same algebraic sign of HTP.

[0762] The temperature dependence of the HTP of the individual compounds may be high or low. The temperature dependence of the pitch of the medium may be compensated by mixing compounds with different temperature dependencies of the HTP in corresponding ratios.

[0763] For the optically active component, a variety of chiral dopants are available to the person skilled in the art, some of which are commercially available, for example cholesteryl nonanoate, R- and S-811, R- and S-1011, R- and S-2011, R- and S-3011, R- and S-4011 or CB15 (all from Merck KGaA, Darmstadt).

[0764] Particularly suitable dopants are compounds which contain one or more chiral groups and one or more mesogenic groups, or one or more aromatic or alicyclic groups which form mesogenic groups with chiral groups.

[0765] Suitable chiral groups are, for example, chiral branched hydrocarbon groups, chiral ethylene glycol, binaphthol or dioxolane, furthermore mono- or polyvalent chiral groups selected from the group consisting of sugar derivatives, sugar alcohols, sugar acids, lactic acid, chiral substituted diols, steroid derivatives, terpenoid derivatives, amino acids or sequences of several (preferably 1 to 5) amino acids.

[0766] Preferred chiral groups are sugar derivatives, such as glucose, mannose, galactose, fructose, arabinose and dextrose; sugar alcohols, such as sorbitol, mannitol, iditol, galactitol or their dehydrated derivatives, in particular dianhydrohexitol, such as dianhydrosorbitol (1,4:3,6-dianhydro-D-sorbitol, isosorbide), dianhydromannitol (isosorbide) or dianhydroiditol (isoiditol); sugar acids, such as gluconic acid, gulonic acid and ketogulonic acid; chiral substituted diol groups, such as mono- or oligoethylene glycol or propylene glycol, in which one or more CH2 groups are substituted by alkyl or alkoxy groups; amino acids, such as alanine, valine, phenylglycine, thiazolyl glycol ... , 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene, 1-6-nitropropene,

[0767] The medium according to the invention preferably comprises a chiral dopant which is selected from the group of known chiral dopants. Suitable chiral groups and mesogenic chiral compounds are described, for example, in DE 34 25 503, DE 35 34 777, DE 35 34 778, DE 35 34779 and DE 35 34 780, DE 43 42 280, EP 01 038 941 and DE 195 41 820. Examples are also the compounds listed in Table F below.

[0768] The chiral compounds preferably used according to the present invention are selected from the formulae shown below.

[0769] Particularly preferred are chiral dopants selected from the compounds of the following formulae AI to A-III and A-Ch:

[0770]

[0771] in

[0772] R a11 , R a12 and R b12 independently of one another represent an alkyl radical having 1 to 15 C atoms, wherein, in addition, one or more non-adjacent CH2 groups may each independently of one another be replaced by -C(R z )=C(R z)-, -C≡C-, -O-, -S-, -CO-, -CO-O-, -O-CO- or -O-CO-O-, with the O and / or S atoms not being directly attached to one another, and wherein, in addition, one or more H atoms may each be replaced by F, Cl, Br, I or CN, preferably alkyl, more preferably n-alkyl, with the proviso that R a12 With R b12 different

[0773] R a21 and R a22 independently of one another represent an alkyl radical having 1 to 15 C atoms, wherein, in addition, one or more non-adjacent CH2 groups may each independently of one another be replaced by -C(R z )=C(R z )-, -C≡C-, -O-, -S-, -CO-, -CO-O-, -O-CO- or -O-CO-O-, in such a way that the O and / or S atoms are not directly connected to one another, and wherein, in addition, one or more H atoms may be replaced by F, Cl, Br, I or CN, preferably both of which are alkyl, more preferably n-alkyl,

[0774] R a31 , R a32 and R b32 independently of one another represent straight-chain and branched alkyl radicals having 1 to 15 C atoms, wherein, in addition, one or more non-adjacent CH2 groups may each independently of one another be replaced by -C(R z )=C(R z )-, -C≡C-, -O-, -S-, -CO-, -CO-O-, -O-CO- or -O-CO-O- are replaced in such a way that the O and / or S atoms are not directly connected to one another, and wherein, in addition, one or more H atoms may be replaced by F, Cl, Br, I or CN,

[0775] Preferably it is alkyl, more preferably n-alkyl, provided that R a32 With R b32 different,

[0776] R z represents H, CH3, F, Cl or CN, preferably H or F,

[0777] R 8 With the R given above a11 one of the meanings of , preferably alkyl, more preferably n-alkyl having 1 to 15 C atoms,

[0778] Z 8 represents -C(O)O-, CH2O, CF2O or a single bond, preferably -C(O)O-,

[0779] A 11As shown below A 12 defined, or alternatively

[0780]

[0781] A 12 express

[0782]

[0783] Preferably

[0784]

[0785] in

[0786] L 12 represents, independently of one another, halogen, CN or alkyl, alkenyl, alkoxy or alkenyloxy having up to 12 C atoms and in which one or more H atoms are optionally replaced by halogen, preferably methyl, ethyl, Cl or F, particularly preferably F,

[0787] A 21 express

[0788]

[0789] A 22 With A 12 The meaning given

[0790] A 31 With A 11 The meaning given,

[0791] or alternatively

[0792]

[0793] A 32 With A 12 The meaning given.

[0794] n2 is, identically or differently at each occurrence, 0, 1 or 2, and n3 is 1, 2 or 3, and

[0795] r is 0, 1, 2, 3 or 4.

[0796] Particularly preferred are dopants selected from the group consisting of compounds of the following formula:

[0797]

[0798]

[0799] in

[0800] m is an integer from 1 to 9, the same or different at each occurrence, and

[0801] n is an integer from 2 to 9, identically or differently at each occurrence.

[0802] Particularly preferred compounds of formula A are compounds of formula A-III.

[0803] Further preferred dopants are derivatives of isosorbide, isomannide or isoidide of the following formula A-IV:

[0804]

[0805] Among them for

[0806] (Dianhydrosorbitol),

[0807] (dianhydromannitol), or

[0808] (Iditol dianhydrogenate),

[0809] Preferably it is dianhydrosorbitol,

[0810] and chiral glycols, for example, diphenyl glycol (hydrogenated benzoin), in particular mesogenic hydrogenated benzoin derivatives of the following formula AV:

[0811]

[0812] including the (S,S) enantiomer not shown,

[0813] in

[0814]

[0815] and

[0816] are each independently 1,4-phenylene (which may also be mono-, di- or trisubstituted by L) or 1,4-cyclohexylene,

[0817] L is H, F, Cl, CN or an optionally halogenated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkoxycarbonyloxy group having 1 to 7 carbon atoms,

[0818] c is 0 or 1,

[0819] X is CH2 or -C(O)-,

[0820] Z 0 is -COO-, -OCO-, -CH2CH2- or a single bond, and

[0821] R 0 It is an alkyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group or an alkylcarbonyloxy group having 1 to 12 carbon atoms.

[0822] Examples of compounds of formula IV are:

[0823]

[0824]

[0825] Compounds of formula A-IV are described in WO 98 / 00428. Compounds of formula AV are described in GB-A-2,328,207.

[0826] Very particularly preferred dopants are chiral binaphthyl derivatives as described in WO 02 / 94805, chiral binaphthol acetal derivatives as described in WO 02 / 34739, chiral TADDOL derivatives as described in WO 02 / 06265 and chiral dopants having at least one fluorinated bridging group and a terminal or central chiral group as described in WO 02 / 06196 and WO 02 / 06195.

[0827] Particularly preferred are chiral compounds of formula A-VI

[0828]

[0829] in

[0830] X 1 , X 2 , Y 1 and Y 2 Each is independently F, Cl, Br, I, CN, SCN, SF5, a straight-chain or branched alkyl radical having 1 to 25 C atoms, which is unsubstituted or mono- or polysubstituted by F, Cl, Br, I or CN and wherein, in addition, one or more non-adjacent CH2 groups may each be independently substituted by -O-, -S-, -NH-, NR x -, -CO-, -COO-, -OCO-, -OCOO-, -S-CO-, -CO-S-, -CH=CH- or -C≡C- in such a way that the O and / or S atoms are not directly bonded to one another, polymerizable radicals with up to 20 C atoms or cycloalkyl or aryl radicals, which may optionally be mono- or polysubstituted by halogen, preferably F, or by polymerizable radicals,

[0831] x 1 and x2 are each independently 0, 1 or 2,

[0832] y 1 and 2are each independently 0, 1, 2, 3 or 4,

[0833] B 1 and B 2 each independently of one another is an aromatic or partially or fully saturated aliphatic six-membered ring, in which one or more CH groups may each be replaced by an N atom and one or more non-adjacent CH2 groups may each be replaced by O or S,

[0834] W 1 and W 2 Each independently of the other is -Z 1 -A 1 -(Z 2 -A 2 ) m -R, and either alternatively R 1 or A 3 , but they are not both H, or

[0835] yes

[0836]

[0837] U 1 and U 2 each independently of one another is CH2, O, S, CO or CS,

[0838] V 1 and V 2 Each independently is (CH2) n , one or two non-adjacent CH2 groups may each be replaced by O or S, or a single bond, n is 1, 2 or 3,

[0839] Z 1 and Z 2 Each is independently -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR x -,-NR x -CO-, -O-CH2-, -CH2-O-, -S-CH2-, -CH2-S-, -CF2-O-, -O-CF2-, -CF2-S-, -S-CF2-, -CH2-CH2-, -CF2-CH2-, -CH2-CF2-, -CF2-CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C≡C-, a combination of two of these radicals in which no two O and / or S and / or N atoms are directly bonded to each other, preferably -CH=CH-COO- or -COO-CH=CH- or a single bond,

[0840] R x represents an alkyl group having 1 to 6 C atoms,

[0841] A 1 , A 2 and A 3 are each independently 1,4-phenylene, in which one or two non-adjacent CH groups may each be replaced by N, 1,4-cyclohexylene, in which one or two non-adjacent CH2 groups may each be replaced by O or S, 1,3-dioxolane-4,5-diyl, 1,4-cyclohexenylene, 1,4-bicyclo[2.2.2]octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, in which each of these radicals may be mono- or polysubstituted by L, and in addition A 1 Can be a single key,

[0842] L is a halogen atom, preferably F, CN, NO2, an alkyl group having 1 to 7 C atoms, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group or an alkoxycarbonyloxy group, wherein one or more H atoms may each be replaced by F or Cl,

[0843] m is independently at each occurrence 0, 1, 2 or 3, and

[0844] R and R 1 Each independently of one another is H, F, Cl, Br, I, CN, SCN, SF5, a straight-chain or branched alkyl radical having 1 or 3 to 25 C atoms, which may optionally be mono- or polysubstituted by F, Cl, Br, I or CN and in which one or more non-adjacent CH2 groups may each be replaced by -O-, -S-, -NH-, -NR 0 -, -CO-, -COO-, -OCO-, -O-COO-, -S-CO-, -CO-S-, -CH=CH- or -C≡C-, wherein no two O and / or S atoms are directly bonded to each other, or a polymerizable group.

[0845] Particularly preferred are chiral binaphthyl derivatives of formula A-VI-1

[0846]

[0847] Among them, ring B, R 0 and Z 0 As defined for Formulas A-IV and AV, and b is 0, 1 or 2.

[0848] In particular those selected from the following formulae A-VI-1a to A-VI-1c:

[0849]

[0850]

[0851] Among them, ring B, R 0 , and Z 0 As defined for Formula A-VI-1, and

[0852] R 0 As defined in formula A-IV, or H or an alkyl group having 1 to 4 carbon atoms, and

[0853] b is 0, 1, or 2,

[0854] and Z 0 In particular -OC(O)- or a single bond.

[0855] The concentration of the one or more chiral dopants in the LC medium is preferably 0.001% to 20%, preferably 0.05% to 5%, more preferably 0.1% to 2%, and most preferably 0.5% to 1.5%. These preferred concentration ranges apply in particular to the chiral dopants S-4011 or R-4011 (both from Merck KGaA) and chiral dopants with the same or similar HTP. For chiral dopants with higher or lower absolute HTP values ​​compared to S-4011, these preferred concentrations must be proportionally reduced, or proportionally increased, according to their HTP value relative to S-4011.

[0856] The pitch p of the LC medium or host mixture according to the invention is preferably in the range from 5 to 50 μm, more preferably in the range from 8 to 30 μm and particularly preferably in the range from 10 to 20 μm.

[0857] Preferably, the medium according to the invention comprises a stabilizer chosen from compounds of formulae ST-1 to ST-18.

[0858]

[0859]

[0860]

[0861]

[0862] in

[0863] R ST represents H, alkyl or alkoxy having 1 to 15 C atoms, wherein in addition, one or more CH2 groups in these radicals may each independently of one another be replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O-, -O-CO- are substituted in such a way that the O atoms are not directly connected to one another, and wherein, in addition, one or more H atoms may be substituted by halogen,

[0864] express

[0865]

[0866]

[0867] Z ST each independently represents -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-CH2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond,

[0868] L 1 and L 2 each independently represents F, Cl, CF3 or CHF2,

[0869] p means 1 or 2,

[0870] q represents 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0871] Among the compounds of formula ST, the compounds of formula

[0872]

[0873] Where n = 1, 2, 3, 4, 5, 6 or 7, preferably n

[0874] =1 or 7

[0875]

[0876] Where n=1, 2, 3, 4, 5, 6 or 7, preferably n=3

[0877]

[0878] Where n=1, 2, 3, 4, 5, 6 or 7, preferably n=3

[0879]

[0880]

[0881] In the compounds of formulae ST-3a and ST-3b, n preferably represents 3. In the compounds of formula ST-2a, n preferably represents 7.

[0882] Very particularly preferred mixtures according to the invention comprise one or more stabilizers selected from the group consisting of compounds of the formulae ST-2a-1, ST-3a-1, ST-3b-1, ST-8-1, ST-9-1 and ST-12:

[0883]

[0884]

[0885] The compounds of the formulae ST-1 to ST-18 are preferably each present in the liquid-crystal mixtures according to the invention in an amount of 0.005 to 0.5%, based on the mixture.

[0886] If the mixtures according to the invention comprise two or more compounds of the formulae ST-1 to ST-18, the concentration is increased accordingly in the case of two compounds to 0.01 to 1%, based on the mixture.

[0887] However, the total proportion of compounds of the formulae ST-1 to ST-18, based on the mixture according to the invention, should not exceed 2%.

[0888] Other mesogenic compounds not explicitly mentioned above can also optionally and advantageously be used in the media according to the invention. Such compounds are known to those skilled in the art.

[0889] In a preferred embodiment of the invention, the total concentration of compounds of the formula UI in the liquid-crystalline medium is 5% or 6% or more, preferably 7% or more, very preferably 8% or more and particularly preferably 10% or 12% or more.

[0890] In a preferred embodiment of the invention, the total concentration of compounds of the formula UII in the liquid-crystalline medium is 5% or more, preferably 6% or more, very preferably 8% or more and especially preferably 10% or more.

[0891] In a preferred embodiment of the present invention, the liquid-crystalline media preferably comprise a total of 2% to 45%, preferably 5% to 40%, more preferably 6% to 30% and especially preferably 8% to 25% of compounds of the formula UI.

[0892] In a preferred embodiment of the present invention, the liquid-crystalline media preferably comprise a total of 2% to 40%, preferably 5% to 30% and particularly preferably 8% to 25% of compounds of the formula UII.

[0893] In a preferred embodiment of the present invention, the liquid-crystalline medium preferably comprises a total of 10% to 60%, preferably 12% to 55%, more preferably 15% to 50% and especially preferably 20% to 45% of compounds of the formulae UI and UII.

[0894] In a preferred embodiment of the present invention, the liquid-crystalline medium comprises a total of 5% to 35%, preferably 6% to 30% and particularly preferably 7% to 25% of one or more compounds of the formula T, which are preferably selected from the formulae T-1a and T-2a, very preferably selected from T-1a-5 and T-2a-2.

[0895] In a preferred embodiment, the medium comprises one or more compounds of formula I, preferably compounds of formula I-2 or formula I-3, in a total concentration in the range of 1% to 30%, more preferably 2% to 25%, very preferably 3% to 20% and especially preferably 5% to 15%.

[0896] In a preferred embodiment of the present invention, the medium contains one or more compounds of formula II, preferably compounds of formula II-1, in a total concentration of 2% to 20%, more preferably 3% to 15%, particularly preferably 5% to 10%.

[0897] In a preferred embodiment of the invention, the medium comprises one or more compounds of the formula IIA-1 in a total concentration of 5% to 25%, more preferably 8% to 20%, particularly preferably 12% to 17%.

[0898] In a preferred embodiment of the present invention, the medium comprises one or more compounds of the formula II-1 in a total concentration of 30% or less, more preferably 25% or less, particularly preferably 20% or less.

[0899] In a preferred embodiment of the present invention, the medium contains one or more compounds of formula III, preferably III-1 and / or III-2, more preferably III-1f and / or III-1b and / or III-1h, in a total concentration of 15% to 60% or 65% or 70%, more preferably 18% to 55%, and particularly preferably 20% to 50%.

[0900] In a preferred embodiment of the invention, the medium comprises one or more compounds of the formula XII in a total concentration of 5% to 30%, more preferably 8% to 25%, particularly preferably 10% to 20%.

[0901] In a preferred embodiment, the medium contains one or more compounds of formula UI and / or formula UII and one or more compounds selected from the group consisting of formula I, II and / or formula IIA, III, XII, T, and their total concentration is preferably 90% or higher, more preferably 95%, 96% or 97% or higher, very preferably 98% or higher and especially 99% or higher.

[0902] In a preferred embodiment, the medium contains one or more compounds of formula UI and / or formula UII and one or more compounds selected from the group consisting of formula I, II and / or formula IIA, III, XII, T, and their total concentration is in the range of 40% to 90% and 10% or more of one or more compounds of formula IV.

[0903] In a preferred embodiment, the medium comprises one or more compounds of formula UI and UII and one or more compounds selected from the group consisting of formula I, II and / or IIA, III, XII and T, and their total concentration is in the range of 40% to 70% and 30% or more of one or more compounds of formula IV.

[0904] In a preferred embodiment, the medium contains one or more compounds of formula UI and / or formula UII and one or more compounds selected from the group consisting of formula I, II and / or formula IIA, III, XII, T, and their total concentration is in the range of 40% to 60% and 40% or more of one or more compounds of formula IV.

[0905] More preferred embodiments of the present invention, alone or in combination with one another, are as follows, wherein some of the compounds are abbreviated using acronyms as described in Tables A and B below and given in Table C:

[0906] - the medium comprises one, two, three, four or more compounds of formula III-1, preferably selected from compounds of formula III-1b, III-1f and III-1h; more preferably compounds of formula III-1b and III-1h;

[0907] - the medium contains the compound of formula III-1b, preferably in a total concentration ranging from 5% to 35%, more preferably from 10% to 30%, in particular from 15% to 25%;

[0908] - the medium contains the compound of formula III-1h, preferably in a total concentration ranging from 5% to 35%, more preferably from 7% to 30%, in particular from 10% to 25%;

[0909] - the medium contains the compounds PPU-TO-S and / or PPTU-TO-S and / or PTPU-TO-S and / or PP(1)TO-nS;

[0910] - the medium contains one or more compounds of formula I-2d, preferably compounds PGU-2-S and / or PGU-3-S and / or PGU-4-S and / or CPU-2-S and / or CPU-3-S and / or CPU-4-S;

[0911] - the medium contains one or more compounds of formula II-1b, preferably compounds PTU-4-S and / or PTU-5-S;

[0912] - the medium contains one or more compounds of the formula PPTU-nS and / or PTPU-nS in a total concentration ranging from 15 to 25%;

[0913] - the medium contains one or more compounds of the formula PPTU-nS and / or PTPU-nS and / or PGTU-nS, wherein n is 1, 2, 3, 4, 5 or 6, in a total concentration ranging from 15% to 30%;

[0914] The medium comprises one or more compounds of the formula ST-3, preferably ST-3a and / or ST-3b, particularly preferably ST-3b-1, in a total concentration in the range from 0.01 to 1%, preferably from 0.05 to 0.5%, in particular from 0.10 to 0.15%.

[0915] The liquid-crystalline media according to the invention preferably have a clearing point of 90° C. or higher, more preferably 100° C. or higher, more preferably 110° C. or higher, more preferably 120° C. or higher, more preferably 130° C. or higher, particularly preferably 140° C. or higher and very particularly preferably 150° C. or higher.

[0916] The liquid-crystalline media according to the invention preferably have a clearing point of 160° C. or less, more preferably 140° C. or less, particularly preferably 120° C. or less and very particularly preferably 100° C. or less.

[0917] The nematic phase of the medium according to the invention preferably extends at least from 0° C. or lower to 90° C. or higher. Advantageously, the medium according to the invention exhibits an even broader nematic phase range, preferably at least from -10° C. or lower to 120° C. or higher, very preferably at least from -20° C. or lower to 140° C. or higher, and in particular, at least from -30° C. or lower to 150° C. or higher, very particularly preferably at least from -40° C. or lower to 170° C. or higher.

[0918] At 1 kHz and 20° C., the Δ∈ of the liquid-crystal media according to the invention is preferably 5 or more, more preferably 7 or more and very preferably 8 or more.

[0919] At 589nm (Na D ) and 20° C., the birefringence (Δn) of the liquid-crystalline medium according to the invention is preferably 0.280 or more, more preferably 0.300 or more, even more preferably 0.320 or more, very preferably 0.330 or more and in particular 0.350 or more.

[0920] At 589nm (Na D) and 20° C., the Δn of the liquid-crystal media according to the invention is preferably in the range from 0.200 to 0.900, more preferably in the range from 0.250 to 0.800, even more preferably in the range from 0.300 to 0.700 and very particularly preferably in the range from 0.350 to 0.600.

[0921] In a preferred embodiment of the present application, the Δn of the liquid-crystal medium according to the invention is preferably 0.50 or more, more preferably 0.55 or more.

[0922] The compounds of the formulae I to III include in each case dielectrically positive compounds having a dielectric anisotropy greater than 3, dielectrically neutral compounds having a dielectric anisotropy less than 3 and greater than −1.5 and dielectrically negative compounds having a dielectric anisotropy of −1.5 or less.

[0923] The compounds of the formulae UI, UII, I, II and III are preferably dielectrically positive.

[0924] In the present application, the expression dielectric positivity describes compounds or components where Δε>3.0, dielectric neutrality describes those where -1.5≤Δε≤3.0, and dielectric negativity describes those where Δε<-1.5. Δε is measured at a frequency of 1 kHz and at 20°C. The dielectric anisotropy of each compound is determined by the results of a 10% solution of each individual compound in a nematic host mixture. If the solubility of each compound in the host mixture is less than 10%, the concentration is reduced to 5%. The capacitance of the test mixture is measured in both a box with a homeotropic orientation and a box with a planar orientation. The box thickness of both types of boxes is about 20 μm. The applied voltage is a rectangular wave with a frequency of 1 kHz and an effective value of typically 0.5 V to 1.0 V, but it is always selected to be lower than the capacitance threshold of each test mixture.

[0925] Δε is defined as (ε || -ε ⊥ ), and ε ave . is (ε || +2ε ⊥ ) / 3.

[0926] The host mixture used for determining the physical constants of the pure compound by extrapolation is ZLI-4792 from Merck KGaA, Germany. The absolute value of the dielectric constant, the birefringence (Δn) and the rotational viscosity (γ1) of the compound are measured by the change in the respective values ​​of the host mixture after adding the compound. The concentration in the host is 10%, or 5% in the case of insufficient solubility. The value is extrapolated to a 100% concentration of the added compound.

[0927] In the examples, the phase sequence of pure compounds is given using the following abbreviations:

[0928] K: crystalline, N: nematic, SmA: smectic A, SmB: smectic B, I: isotropic.

[0929] The component having a nematic phase was measured as it was at a measuring temperature of 20° C., and all other components were treated like compounds.

[0930] In both cases, unless explicitly stated otherwise, the expression "threshold voltage" in this application refers to the optical threshold and is for a 10% relative contrast ratio (V 10 ) and the expression "saturation voltage" refers to optical saturation and is for 90% relative contrast (V 90 ). The capacitive threshold voltage (V0), also called the Freedericks threshold (V Fr ).

[0931] Unless expressly stated otherwise, the parameter ranges indicated in this application include the limit values.

[0932] The different upper and lower value limits indicated for the different property ranges combine with one another to give further preferred ranges.

[0933] Throughout the application, the following conditions and definitions apply, unless otherwise stated. All concentrations are given in weight percent and relate to the respective overall mixture, all temperature values ​​are given in degrees Celsius and all temperature differences are given in differential degrees. All physical properties are determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals", Status November 1997, Merck KGaA (Germany) and are given for a temperature of 20°C, unless explicitly stated otherwise. The optical anisotropy (Δn) is determined at a wavelength of 589.3 nm. The dielectric anisotropy (Δε) is determined at a frequency of 1 kHz. The threshold voltage and all other electro-optical properties are determined using a test cell produced by Merck KGaA, Germany. The cell thickness of the test cell used to determine Δε is approximately 20 μm. The electrodes are 1.13 cm 2 Area and guard ring of circular ITO electrode. || ), the orientation layer is SE-1211 from Nissan Chemicals, Japan, and for the plane orientation (ε ⊥ ), the orientation layer is polyimide AL-1054 from Japan SyntheticRubber. Using a Solatron 1260 frequency response analyzer, a sine wave and 0.3Vrms The capacitance is determined by the voltage at which the light is measured. The light used in the electro-optical measurement is white light. An apparatus using a commercially available DMS instrument from Autronic-Melchers, Germany, is used here. The characteristic voltage is determined under perpendicular observation. The threshold voltage (V 10 )、Mid-gray voltage (V 50 ) and saturation voltage (V 90 ).

[0934] As in A.Penirschke et al. "Cavity Perturbation Method for Characterization of Liquid Crystals up to 35GHz", 34 th The liquid crystal media described in the European Microwave Conference—Amsterdam, pp. 545-548 were investigated in the microwave frequency range with regard to their properties. In this respect, A. Gaebler et al. "Direct Simulation of Material Permittivities ...", 12 MTC 2009—International Instrumentation and Measurement Technology Conference, Singapore, 2009 (IEEE), pp. 463-467 and DE 10 2004 029 429 A were also compared, in which the measurement methods are likewise described in detail.

[0935] Liquid crystals are introduced into polytetrafluoroethylene (PTFE) or quartz capillaries. The inner diameter of the capillary is 0.5 mm and the outer diameter is 0.78 mm. The effective length is 2.0 cm. The filled capillary is introduced into the center of a cylindrical cavity with a resonant frequency of 19 GHz. The length of the cavity is 11.5 mm and the radius is 6 mm. An input signal (source) is then applied and the frequency-dependent response of the cavity is recorded using a commercial vector network analyzer (N5227APNA microwave network analyzer, Keysight Technologies Inc. USA). For other frequencies, the dimensions of the cavity are adapted accordingly.

[0936] The change in resonance frequency and Q factor between the measurement using a capillary filled with liquid crystal and the measurement using a capillary not filled with liquid crystal is used to determine the dielectric constant and loss angle at the corresponding target frequency, which is obtained by the above-mentioned publication A. Penirschke et al., 34 thEquations 10 and 11 are determined as described in European Microwave Conference—Amsterdam, pp. 545-548.

[0937] The values ​​of the components of the properties perpendicular and parallel to the director of the liquid crystal are obtained by the alignment of the liquid crystal in a magnetic field. For this purpose, the magnetic field of a permanent magnet is used. The magnetic field strength is 0.35 Tesla.

[0938] Preferred components are phase shifters, varactor diodes, wireless and radio wave antenna arrays, matching circuits, adaptive filters and others.

[0939] In this application, the term "compound" means one compound as well as a plurality of compounds, unless specifically stated otherwise.

[0940] All mixtures according to the present invention are nematic. The liquid crystal medium according to the present invention preferably has a nematic phase within the preferred range given above. Here, the statement that it has a nematic phase means that on the one hand, no smectic phase is observed at low temperatures at the corresponding temperature and no crystallization is observed, and on the other hand, no clearing occurs when heated from the nematic phase. At high temperatures, the clearing point is measured in a capillary by conventional methods. The study at low temperature is carried out in a flow viscometer at the corresponding temperature and is checked by the storage of bulk samples: at a given temperature T, the storage stability (LTS) in the bulk of the medium according to the present invention is determined by visual inspection. 2g of the medium of interest is filled into a closed glass container (bottle) of a suitable size placed in a refrigerator at a predetermined temperature. Check the bottle at a defined time interval whether a smectic phase or crystallization occurs. For each material and each temperature, two bottles are stored. If the appearance of crystallization or smectic phase is observed in at least one of the two corresponding bottles, the test is terminated, and the time of the last inspection before the appearance of a higher ordered phase is observed is recorded as the corresponding storage stability. Finally the test was terminated after 1000 hours, ie an LTS value of 1000 hours means that the mixture was stable at a given temperature for at least 1000 hours.

[0941] The liquid crystals used preferably have a positive dielectric anisotropy, which is preferably 2 or more, preferably 4 or more, particularly preferably 6 or more and very particularly preferably 10 or more.

[0942] Furthermore, the liquid crystal media according to the invention are characterized by high anisotropy values ​​in the microwave range. The birefringence at about 19 GHz is, for example, preferably 0.14 or more, particularly preferably 0.15 or more, particularly preferably 0.20 or more, particularly preferably 0.25 or more and very particularly preferably 0.30 or more. In addition, the birefringence is preferably 0.80 or less.

[0943] The dielectric anisotropy in the microwave range is defined as

[0944] △ε r ≡(ε r,|| -ε r,⊥ ).

[0945] The tunability (τ) is defined as

[0946] τ≡(△ε r / ε r,|| ).

[0947] Material quality (η) is defined as

[0948] η≡(τ / tanδ εr,max. ),in

[0949] The maximum dielectric loss is

[0950] tanδε r,max ≡max.{tanδ εr,⊥ ,;tanδ εr ,||}.

[0951] The tunability τ of the medium according to the invention measured at 20° C. and 19 GHz is 0.250 or more, preferably 0.300 or more, 0.310 or more, 0.320 or more, 0.330 or more, or 0.340 or more, very preferably 0.345 or more and in particular 0.350 or more.

[0952] Preferably, the material quality (η) of the liquid crystal material is 6 or more, preferably 8 or more, preferably 10 or more, preferably 15 or more, preferably 17 or more, preferably 20 or more, particularly preferably 25 or more and very particularly preferably 30 or more.

[0953] In the corresponding components, the phase shifter quality of the preferred liquid crystal material is 15° / dB or greater, preferably 20° / dB or greater, preferably 30° / dB or greater, preferably 40° / dB or greater, preferably 50° / dB or greater, particularly preferably 80° / dB or greater and very particularly preferably 100° / dB or greater.

[0954] However, in some embodiments, liquid crystals having negative values ​​of dielectric anisotropy may also be advantageously used.

[0955] The liquid crystals used are either a single substance or a mixture and preferably have a nematic phase.

[0956] The liquid crystal medium according to the invention may contain other additives and chiral dopants in the usual concentrations. The total concentration of these other components is 0% to 10%, preferably 0.1% to 6%, based on the entire mixture. The concentration of the individual compounds used is preferably 0.1% to 3% each. When the values ​​and concentration ranges of the liquid crystal components and liquid crystal compounds of the liquid crystal medium are quoted in this application, the concentrations of these and similar additives are not taken into account.

[0957] Preferably, the media according to the invention contain one or more chiral compounds as chiral dopants to adjust their cholesteric pitch. Their total concentration in the media according to the invention is preferably in the range of 0.05% to 15%, more preferably 1% to 10% and most preferably 2% to 6%.

[0958] Optionally, the medium according to the invention may contain other liquid crystal compounds to adjust the physical properties. Such compounds are known to those skilled in the art. Their concentration in the medium according to the invention is preferably from 0% to 30%, more preferably from 0.1% to 20% and most preferably from 1% to 15%.

[0959] Respectively, for relative tuning or relative contrast ratio of photoelectric response varying from 0% to 90% (t 90 –t0), the response time is the rise time (τ on ) is given, that is, including the delay time (t 10 –t0); for the relative contrast ratio of the relative tuning or photoelectric response changing from 100% back to 10% (t 100 –t 10 ) time, the response time is the decay time (τ off ) is given, and the total response time (τ 总计 =τ on +τ off ).

[0960] The liquid crystal medium according to the present invention consists of a plurality of compounds, preferably 3 to 30, more preferably 4 to 20 and very preferably 4 to 16 compounds. These compounds are mixed in a conventional manner. Usually, the desired amount of compound used in a smaller amount is dissolved in the compound used in a larger amount. If the temperature is above the clearing point of the compound used in a higher concentration, it is particularly easy to observe that the dissolution process is complete. However, the medium can also be prepared in other conventional ways, for example using a so-called premix, which can, for example, be a homogeneous mixture or a eutectic mixture of compounds, or using a so-called "multi-bottle" system, the components of which are themselves ready-to-use mixtures.

[0961] All temperatures, such as melting points T(C, N) or T(C, S), the transition from the smectic (S) phase to the nematic (N) phase T(S, N) and the clearing point of the liquid crystal T(N, I), are expressed in degrees Celsius. All temperature differences are expressed as a difference in degrees.

[0962] In the present invention and in particular in the following examples, the structures of the mesogenic compounds are indicated with the aid of abbreviations (also called acronyms). In these acronyms, the chemical formulae are abbreviated as follows using the following Tables A to C. All groups C n H 2n+1 , C m H 2m+1 and C l H 2l+1 and C n H 2n-1 , C m H 2m-1 and C l H 2l-1 = represents a straight-chain alkyl or alkylene group, respectively, having in each case n, m or 1 C atoms, wherein n and m are independently 1, 2, 3, 4, 5, 6 or 7, and 1 is 1, 2 or 3. Table A lists the codes for the ring elements of the core structures of the compounds, while Table B shows the linking groups and the terminal groups. Table C shows the illustrative structures of the compounds and their corresponding abbreviations.

[0963] Table A: Ring elements

[0964]

[0965]

[0966]

[0967]

[0968]

[0969] Table B: Linking Groups

[0970]

[0971] Table B: End Groups

[0972]

[0973]

[0974] Use in combination with other

[0975]

[0976] wherein n and m each represent an integer, and the triple dots "..." are placeholders for other abbreviations from this table.

[0977] The branched side groups are numbered starting from the position immediately adjacent to ring (1), with the longest chain selected, the lower number indicating the branch length, and the superscript number in brackets indicating the branch position, for example:

[0978]

[0979] The following table shows illustrative structures and their corresponding abbreviations. These are shown to illustrate the meaning of the abbreviation conventions. They further indicate preferred compounds for use.

[0980] Table C: Illustrative Structure

[0981] The following illustrative structures are examples and compounds which are preferably additionally used in the medium:

[0982]

[0983]

[0984]

[0985]

[0986]

[0987]

[0988]

[0989]

[0990]

[0991]

[0992]

[0993]

[0994]

[0995]

[0996]

[0997] wherein m and n are the same or different and are 1, 2, 3, 4, 5, 6 or 7.

[0998] Preferably, the medium according to the invention comprises one or more compounds chosen from the compounds of Table C.

[0999] The following table (Table D) shows illustrative compounds which can be used as alternative stabilizers in the mesomorphic media according to the invention. The total concentration of these and similar compounds in the medium is preferably 5% or less.

[1000] Table D

[1001]

[1002]

[1003] In a preferred embodiment of the present invention, the mesogenic medium comprises one or more compounds selected from the group of compounds from Table D.

[1004] The following table (Table E) shows illustrative compounds which can preferably be used as chiral dopants in the mesogenic media according to the present invention.

[1005] Table E

[1006]

[1007]

[1008]

[1009] In a preferred embodiment of the present invention, the mesogenic medium comprises one or more compounds selected from the group of compounds from Table E.

[1010] The mesogenic medium according to the present application preferably comprises two or more, preferably four or more compounds selected from the group consisting of compounds from the above table.

[1011] Unless indicated otherwise, parts or percentages are parts or percentages by weight.

[1012] In the above and below:

[1013] V o Indicates the threshold voltage at 20°C, capacitive [V]

[1014] n e Indicates the extraordinary refractive index at 20°C and 589nm.

[1015] n o It represents the ordinary refractive index at 20℃ and 589nm.

[1016] Δn represents the optical anisotropy at 20°C and 589 nm.

[1017] ε ⊥represents the dielectric permittivity perpendicular to the director at 20°C and 1kHz,

[1018] ε || represents the dielectric permittivity parallel to the director at 20°C and 1kHz,

[1019] Δε represents the dielectric anisotropy at 20°C and 1kHz,

[1020] cl.p.,T(N,I) represents the clearing point [℃],

[1021] γ1 represents the rotational viscosity [mPa·s] measured at 20°C,

[1022] K1 represents the elastic constant at 20°C, the “bending” deformation [pN],

[1023] K2 represents the elastic constant at 20°C, "twist" deformation [pN],

[1024] K3 represents the elastic constant at 20°C, "bending" deformation [pN],

[1025] K avg . represents the average elastic constant, which is defined as and

[1026] LTS stands for Low Temperature Stability (Nematic Phase) determined as detailed in test cells or in bulk.

[1027] Unless expressly stated otherwise, all values ​​indicated in this application with respect to temperature, such as melting point T(C,N), transition from smectic (S) phase to nematic (N) phase T(S,N) and clearing point T(N,I) or cl.p., are indicated in degrees Celsius (°C). Mp denotes melting point. Furthermore, Tg=glassy state, C=crystalline state, N=nematic phase, S=smectic phase and I=isotropic phase. The numbers between these symbols denote transition temperatures.

[1028] Unless explicitly indicated otherwise, the term "threshold voltage" used in the present invention relates to the capacitive threshold (V0), also known as the Freedericksz threshold. In embodiments, as is commonly used, the optical threshold (V 10 ).

[1029] The display used to measure the capacitance threshold voltage consisted of two plane-parallel glass outer plates with a spacing of 20 μm, each with an electrode layer on the inside and an unrubbed polyimide alignment layer on top, which achieved vertical edge alignment of the liquid crystal molecules.

[1030] By "HTP" is meant the helical twisting power (in μm) of an optically active or chiral substance in a LC medium. Unless otherwise indicated, the HTP was measured at a temperature of 20°C on a commercially available nematic LC host mixture MLD-6260 (Merck KGaA).

[1031] The clearing point was measured using a Mettler Thermosystem FP900. The optical anisotropy (Δn) was measured using an AbbeRefractometer H005 (sodium spectrum lamp Na10 at 589 nm, 20°C). The dielectric anisotropy (Δε) was measured using an LCR-Meter E4980A / Agilent (G005) (ε parallel box with JALS 2096-R1) at 20°C. The on-voltage (V0) was measured using an LCR-Meter E4980A / Agilent (G005) (ε parallel box with JALS 2096-R1) at 20°C. The rotational viscosity (γ1) was measured using a TOYO LCM-2 (0002) (γ1 negative box with JALS-2096-R 1) at 20°C. Elastic constants (K1, splay) were measured at 20°C using LCR-Meter E4980A / Agilent (G005) (ε parallel cell with JALS2096-R1). K3: Elastic constants (K3, bending) were measured at 20°C using LCR-Meter E4980A / Agilent (G005) (ε parallel cell with JALS 2096-R1).

[1032] Unless expressly indicated otherwise, all concentrations in the present application are indicated as weight percent and relate to the respective mixture as a whole (without solvent) comprising all solid or liquid crystal components. Unless expressly indicated otherwise, all physical properties are determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals", Status November 1997, Merck KGaA, Germany, and apply to a temperature of 20°C. Example

[1033] The following examples illustrate the invention without limiting it in any way.

[1034] It is clear to the person skilled in the art what properties can be achieved from the physical properties and to what extent they can be modified. In particular, the combination of various properties which can preferably be achieved is therefore well defined to the person skilled in the art.

[1035] Synthesis Example Abbreviations:

[1036] dist. Distillation

[1037] DABCO 1,4-diazabicyclo[2.2.2]octane

[1038] THF Tetrahydrofuran

[1039] MTB ether methyl-tert-butyl ether

[1040] dist. Distillation

[1041] XPhos 2-Dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl

[1042] XPhos Pd G2 Chloro(2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl)[2-(2'-amino-1,1'-biphenyl)palladium(II)

[1043] Synthesis Example 1: 2-[4-(4-butylcyclohexyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene

[1044] Step 1.1: 4-[4-(4-Butylcyclohexyl)phenyl]-3,5-difluoro-aniline

[1045]

[1046] Bis(benzhydrylene-acetone)palladium(0) (20 mg, 0.04 mmol) and tri-(o-tolyl)phosphine (50 mg, 0.2 mmol) were added to a mixture of [4-(4-butylcyclohexyl)phenyl]boronic acid (CAS516510-90-0) (4.5 g, 17 mmol) and 3,5-difluoro-4-iodoaniline (4.3 g, 17 mmol) in acetone (50 ml) under argon atmosphere at 50°C. Aqueous sodium hydroxide solution (2N) (17.0 ml, 34 mmol) was slowly added at reflux temperature and the reaction mixture was heated at reflux temperature overnight. Then, it was cooled to room temperature and quenched with distilled water and hydrochloric acid (2N), and diluted with MTB ether. The aqueous phase was separated and extracted with MTB ether. The combined organic layers were washed with brine, dried (sodium sulfate) and concentrated in vacuo. The residue was purified by silica gel chromatography (eluent 1-chlorobutane) to give 4-[4-(4-butylcyclohexyl)phenyl]-3,5-difluoro-aniline as a yellow solid.

[1047] Step 1.2: 2-[4-(4-Butylcyclohexyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene

[1048]

[1049] Thiophosgene (1.3 ml, 16 mmol) was slowly added to a solution of 4-[4-(4-butylcyclohexyl)phenyl]-3,5-difluoro-aniline (4.8 g, 12 mmol) and DABCO (4.0 g, 36 mmol) in dichloromethane (60 ml) at 0°C under argon atmosphere. The reaction mixture was stirred overnight at room temperature. It was then quenched with distilled water and brine. The aqueous phase was separated and extracted with dichloromethane. The combined organic phases were washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue was purified by silica gel chromatography (eluent heptane) and crystallization (heptane) to give colorless crystals of 2-[4-(4-butylcyclohexyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene.

[1050] Phase sequence K 91 N 160 I.

[1051] Δε=3.01

[1052] Δn=0.2455

[1053] γ1=525mPas

[1054] Synthesis Example 2: 2-[4-(4-butylphenyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene

[1055] Step 2.1: 4-[4-(4-Butylphenyl)phenyl]-3,5-difluoro-aniline

[1056]

[1057] Bis(benzhydrylene-acetone)palladium(0) (20 mg, 0.04 mmol) and tri-(o-tolyl)phosphine (50 mg, 0.2 mmol) are added to a mixture of [4-(4-butylphenyl)phenyl]boronic acid (CAS 145413-17-8; 4.5 g, 17 mmol) and 3,5-difluoro-4-iodoaniline (4.3 g, 17 mmol) in acetone (50 ml) at 50° C. under argon atmosphere. Aqueous sodium hydroxide solution (2N) (18.0 ml, 36 mmol) is added slowly at reflux temperature and the reaction mixture is heated at reflux temperature overnight. It is then allowed to cool to room temperature and quenched with distilled water and hydrochloric acid (2N) and diluted with MTB ether. The aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with brine, dried (sodium sulfate) and concentrated in vacuo. The residue was purified by silica gel chromatography (eluent 1-chlorobutane) to give 4-[4-(4-butylphenyl)phenyl]-3,5-difluoro-aniline as a yellow solid.

[1058] Step 2.2: 2-[4-(4-Butylphenyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene

[1059] Thiophosgene (1.3 ml, 16 mmol) was slowly added to a solution of 4-[4-(4-butylphenyl)phenyl]-3,5-difluoro-aniline (4.7 g, 14 mmol) and DABCO (4.0 g, 36 mmol) in dichloromethane (60 ml) at 0°C under argon atmosphere. The reaction mixture was stirred overnight at room temperature. It was then quenched with distilled water and brine. The aqueous phase was separated and extracted with dichloromethane. The combined organic phases were washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue was purified by silica gel chromatography (eluent heptane) and crystallization (heptane) to give colorless crystals of 2-[4-(4-butylphenyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene.

[1060] Phase sequence K 114 SmA(98)N 139 I.

[1061] Δε=3.92Δn=0.341

[1062] 4γ1=430mPas

[1063] Synthesis Example 3: 2-[2-(4-butylphenyl)ethynyl]-1,3-difluoro-5-isothiocyanato-benzene

[1064] Step 3.1: 4-[2-(4-Butylphenyl)ethynyl]-3,5-difluoro-aniline

[1065]

[1066] XPhos Pd G2 (40 mg, 0.05 mmol), XPhos (25 mg, 0.05 mmol) and copper (I) iodide (5 mg, 0.03 mmol) are added to a mixture of 1-butyl-4-ethynylbenzene (4.0 g, 25 mmol) and 3,5-difluoro-4-iodoaniline (6.3 g, 25 mmol) in diisopropylamine (60 ml) and THF (60 ml) under an argon atmosphere at a temperature slightly below the boiling point. The reaction mixture is heated overnight at reflux temperature. It is then allowed to cool to room temperature, and the precipitate is filtered off and washed with THF. The filtrate is concentrated in vacuo. The residue is purified by silica gel chromatography (eluent 1-chlorobutane) to give 4-[2-(4-butylphenyl)ethynyl]-3,5-difluoro-aniline (3) as a brown oil.

[1067] Step 3.2: 2-[2-(4-Butylphenyl)ethynyl]-1,3-difluoro-5-isothiocyanato-benzene

[1068]

[1069] Thiophosgene (1.9 ml, 24 mmol) is slowly added to a solution of 4-[2-(4-butylphenyl)ethynyl]-3,5-difluoro-aniline (6.1 g, 20 mmol) and DABCO (6.0 g, 53 mmol) in dichloromethane (100 ml) at 0°C under argon atmosphere, and the reaction mixture is stirred at room temperature for 1 hour. It is then quenched with distilled water and brine. The aqueous phase is separated and extracted with dichloromethane. The combined organic phases are washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue is purified by silica gel chromatography (eluent heptane) and crystallization (heptane) to give colorless crystals of 2-[2-(4-butylphenyl)ethynyl]-1,3-difluoro-5-isothiocyanato-benzene.

[1070] Phase sequence: K 44 N(29)I.

[1071] Δε=3.70

[1072] Δn=0.3690

[1073] γ1=53mPas

[1074] Synthesis Example 4: 1,3-Difluoro-5-isothiocyanato-2-[4-[4-(trifluoromethoxy)-phenyl]phenyl]benzene

[1075] Step 4.1: 3,5-Difluoro-4-[4-[4-(trifluoromethoxy)phenyl]phenyl]aniline

[1076]

[1077] Bis(benzhydrylene-acetone)palladium(0) (20 mg, 0.04 mmol) and tri-(o-tolyl)phosphine (45 mg, 0.1 mmol) were added to [4-(4-(trifluoromethoxy)phenyl]phenyl]-boronic acid (CAS 501944-50-9) (4.0 g, 14 mmol) and 4-bromo-3,5-difluoro-aniline (3.0 g, 14 mmol) in acetone (40 ml). Aqueous sodium hydroxide solution (2N) (15 ml, 30 mmol) was slowly added at reflux temperature, and the reaction mixture was heated overnight at reflux temperature. Then, it was cooled to room temperature and quenched with distilled water and diluted with MTB ether. The aqueous phase was separated and extracted with MTB ether. The combined organic phases were washed with brine, dried (sodium sulfate) and concentrated in vacuo. The residue was purified by silica gel chromatography (eluent 1-chlorobutane) to give 3,5-difluoro-4-[4-[4-(trifluoromethoxy)phenyl]phenyl]aniline as a yellow solid.

[1078] Step 4.2: 1,3-Difluoro-5-isothiocyanato-2-[4-[4-(trifluoromethoxy)phenyl]phenyl]-benzene

[1079]

[1080] Thiophosgene (1.0 ml, 13 mmol) was slowly added to a solution of 3,5-difluoro-4-[4-[4-(trifluoromethoxy)phenyl]phenyl]aniline (3.9 g, 11 mmol) and DABCO (3.0 g, 27 mmol) in dichloromethane (50 ml) at 0°C under argon atmosphere. The reaction mixture was stirred overnight at room temperature. It was then quenched with distilled water and brine. The aqueous phase was separated and extracted with dichloromethane. The combined organic phases were washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue was purified by silica gel chromatography (eluent heptane) and crystallization (heptane) to give white crystals of 1,3-difluoro-5-isothiocyanato-2-[4-[4-(trifluoromethoxy)phenyl]phenyl]benzene.

[1081] Phase sequence K 135 N(128)I.

[1082] Δε=3.47

[1083] Δn=0.3212

[1084] Similar to Synthesis Examples 1 to 4, the following compounds were obtained:

[1085]

[1086]

[1087]

[1088]

[1089]

[1090]

[1091]

[1092] The preferred compound of formula UII is prepared as follows

[1093] Synthesis Reference Example 1: 2-[4-[2-(4-butylphenyl)ethynyl]phenyl]-1,3-difluoro-5-isothiocyanato-benzene

[1094] Step 1.1: 2-[4-[2-(4-Butylphenyl)ethynyl]phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

[1095] XPhos Pd G2 (170 mg, 0.2 mmol), XPhos (100 mg, 0.2 mmol) and copper (I) iodide (20 mg, 0.1 mmol) were added to a mixture of 1-butyl-4-ethynylbenzene (18.0 g, 0.1 mol) and 2-(4-bromophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (30.0 g, 0.1 mol) in diisopropylamine (250 ml) and THF (27 ml) at 55 °C under argon atmosphere. The reaction mixture was heated at reflux temperature overnight. It was then allowed to cool to room temperature, filtered and concentrated in vacuo. The residue was dissolved in toluene, washed with distilled water, dried (sodium sulfate), filtered and concentrated in vacuo. The crude product was purified by chromatography on silica gel (eluent toluene) and crystallization (heptane) to give 2-[4-[2-(4-butylphenyl)ethynyl]phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane as yellow crystals.

[1096] Step 1.2: 4-[4-[2-(4-Butylphenyl)ethynyl]phenyl]-3,5-difluoro-aniline

[1097] Bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II) (7 mg, 0.01 mmol) is added to a mixture of 2-[4-[2-(4-butylphenyl)ethynyl]phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.5 g, 10 mmol) and 4-bromo-3,5-difluoro-aniline (2.0 g, 10 mmol) in ethylene glycol (20 ml) and THF (20 ml) at 60° C. under argon atmosphere. Aqueous sodium hydroxide solution (2N) (7.5 ml, 15 mmol) is added slowly at reflux temperature and the reaction mixture is heated at reflux temperature overnight. It is then allowed to cool to room temperature and quenched with acetic acid (0.9 ml, 16 mmol) and distilled water. MTB ether is added and the aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue was purified by silica gel chromatography (eluent dichloromethane) to give 4-[4-[2-(4-butylphenyl)ethynyl]phenyl]-3,5-difluoro-aniline as a yellow solid.

[1098] Step 1.3: 2-[4-[2-(4-butylphenyl)ethynyl]phenyl]-1,3-difluoro-5-isothiocyanato-benzene

[1099]

[1100] Thiophosgene (0.7 ml, 9 mmol) was slowly added to a solution of 4-[4-[2-(4-butylphenyl)ethynyl]phenyl]-3,5-difluoro-aniline (2.9 g, 8 mmol) and DABCO (2.3 g, 21 mmol) in dichloromethane (40 ml) at 0°C under argon atmosphere. The reaction mixture was stirred at room temperature for 1 hour. It was then quenched with distilled water and brine. The aqueous phase was separated and extracted with dichloromethane. The combined organic phases were washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue was purified by silica gel chromatography (eluent heptane) and crystallization (heptane) to give colorless crystals of 2-[4-[2-(4-butylphenyl)ethynyl]phenyl]-1,3-difluoro-5-isothiocyanato-benzene.

[1101] Phase sequence K 120 N 178 I.

[1102] Δε=4.92

[1103] Δn=0.4369

[1104] γ1=697mPas

[1105] Analogously to Reference Example 1, the following compound was obtained:

[1106]

[1107]

[1108]

[1109]

[1110] Mixture Examples

[1111] Comparative Examples C1 , C2 and Mixture Examples M1 to M13 were prepared and studied as described below.

[1112] Comparative Example C1

[1113]

[1114]

[1115] Mixture Example M1

[1116]

[1117]

[1118] Mixture Example M1 differs from Comparative Example C1 in that it additionally comprises compounds PTPUI-4-S, PPTUI-4-S and PTUI-4-S. Thus, due to the higher tunability τ and lower loss tan δ εr,⊥ , medium M1 exhibits an improved quality factor η.

[1119] Comparative mixture C2

[1120]

[1121] Mixture Example M2

[1122]

[1123] Mixture Example M2 differs from Comparative Example C2 in that it additionally contains the compound PTUI-4-S. Therefore, due to the lower loss tan δ εr,⊥ , medium M2 exhibits an improved quality factor η.

[1124] Mixture Example M3

[1125]

[1126]

[1127] Mixture Example M4

[1128]

[1129] Mixture Example M5

[1130]

[1131]

[1132] Mixture Example M6

[1133]

[1134]

[1135] Mixture Example M7

[1136]

[1137] Mixture Example M8

[1138]

[1139]

[1140] Mixture Example M9

[1141]

[1142]

[1143] Mixture Example M10

[1144]

[1145] Mixture Example M11

[1146]

[1147]

[1148] Mixture Example M12

[1149]

[1150]

[1151] Mixture Example M13

[1152]

Claims

1. A liquid-crystalline medium comprising one or more compounds of the formula UI in a total concentration of 5% to 40% by weight, in R U represents H, a straight-chain or branched non-fluorinated alkyl group having 1 to 12 C atoms or a non-fluorinated alkenyl group having 2 to 12 C atoms, wherein one or more CH2- groups may be replaced by substitution, wherein one or more non-adjacent CH2-groups may be replaced by O, or represents a group R P , R P Indicates halogen, CN, NCS, fluorinated alkyl, R F -O- or R F -S-, where R F represents a fluorinated alkyl or fluorinated alkenyl group having up to 9 C atoms, Z U1 Indicates -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or -C≡CC ≡C-， X U1 , X U2 Identically or differently represent Cl or F, and represents a group selected from the following group: a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L, b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydronaphthalene-2,6-diyl, tetrahydronaphthalene-5,8-diyl, decahydronaphthalene-2,6-diyl, bicyclo[1.1.1]pentane-1,3-diyl, 4,4'-dicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl or spiro[3.3]heptane-2,6-diyl, in which one or two CH groups may be replaced by N, one or more non-adjacent CH2 groups may be replaced by -O- and / or -S-, and in which one or more H atoms may be replaced by L, c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl and selenophene-2,5-diyl, each of which may also be mono- or poly-substituted by L, L, identically or differently on each occurrence, represents F, Cl, CN, SCN, SF5 or linear or branched, in each case optionally fluorinated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, each having 1 to 12 C atoms, u is 0 or 1, v is 0 or 1, The restriction condition is and does not simultaneously represent an optionally fluorinated 1,4-phenylene group, Wherein the liquid crystal medium comprises one or more compounds of formula UII-1 in R U represents H, straight-chain or branched alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms, wherein one or more CH2-groups may be replaced by substitution, wherein one or more non-adjacent CH2-groups may be replaced by O, or represents a group R P , R P Indicates halogen, CN, NCS, R F -、R F -O- or R F -S-, where R F represents a fluorinated alkyl or fluorinated alkenyl group having up to 9 C atoms, X U1 , X U2 Identically or differently represent Cl or F, and represents a group selected from the following group: a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L, b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydronaphthalene-2,6-diyl, tetrahydronaphthalene-5,8-diyl, decahydronaphthalene-2,6-diyl, bicyclo[1.1.1]pentane-1,3-diyl, 4,4'-dicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl and spiro[3.3]heptane-2,6-diyl, in which one or two CH groups may be replaced by N, one or more non-adjacent CH2 groups may be replaced by -O- and / or -S-, and in which one or more H atoms may be replaced by L, c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may also be mono- or poly-substituted by L, L, identically or differently on each occurrence, represents F, Cl, CN, SCN, SF5 or linear or branched, in each case optionally fluorinated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, each having 1 to 12 C atoms, Compounds of formula UI are not included.

2. A liquid-crystalline medium according to claim 1, wherein the compound of formula UI is selected from the group of compounds of formulae UI-1, UI-2 and UI-3, Where R U , X U1 and X U2 has the meaning given to it in claim 1, In formula UI-3, and At least one of them represents trans-1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydronaphthalene-2,6-diyl, tetrahydronaphthalene-5,8-diyl, decahydronaphthalene-2,6-diyl, bicyclo[1.1.1]pentane-1,3-diyl, 4,4′-dicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl and spiro[3.3]heptane-2,6-diyl, in which one or two CH groups may be replaced by N, one or more non-adjacent CH2 groups may be replaced by -O- and / or -S-, and in which one or more H atoms may be replaced by L, wherein L, identically or differently at each occurrence, represents F, Cl, CN, SCN, SF5 or a linear or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy group, each having 1 to 12 C atoms.

3. A liquid crystal medium according to claim 1 or 2, wherein X U1 and X U2 Indicates F.

4. A liquid-crystalline medium according to claim 1 or 2, wherein the medium comprises one or more compounds of the formula UII selected from the group of formulae UII-2 and UII-3, Where R U , X U1 and X U2 , and has the meaning given in claim 1.

5. A liquid-crystalline medium according to claim 1 or 2, wherein the medium additionally comprises one or more compounds selected from the group of compounds of the formulae I, II and III: in R 1 represents H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, wherein one or more CH2- groups may be replaced by Instead, n is 0, 1, or 2, to In each occurrence, they are expressed independently of each other Where R L represents, identically or differently on each occurrence, H or alkyl having 1 to 6 C atoms, or wherein one or more H atoms may be replaced by an alkyl radical having 1 to 6 C atoms or by F, And among them Alternatively, R 2 represents H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, wherein one or more CH2- groups may be replaced by Instead, Z 21 represents trans-CH=CH-, trans-CF=CF- or -C≡C-, and and Independently express Where R L In each occurrence, the same or different representation of H or Alkyl having 1 to 6 C atoms, or or One or more H atoms may have 1 to 6 C Alkyl or F substitution of atoms, R 3 represents H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, wherein one or more CH2- groups may be replaced by Instead, Z 31 and Z 32 one of them represents trans-CH=CH-, trans-CF=CF-, or -C≡C-, and the other independently thereof represents -C≡C-, trans-CH=CH-, trans-CF=CF-, or a single bond, and to Independently express Where R L In each occurrence, the same or different representation of H or Alkyl having 1 to 6 C atoms, or or wherein one or more H atoms may be replaced by an alkyl radical having 1 to 6 C atoms or by F, And among them Alternatively, 6. Liquid-crystalline medium according to claim 1 or 2, wherein the medium comprises one or more compounds selected from the group of compounds of the formulae I-1 to I-5, in L 1 , L 2 and L 3 represents H or F in the same or different manner on each occurrence, and R 1 , and has the meaning given in claim 5 for formula I.

7. A liquid-crystalline medium according to claim 1 or 2, wherein the medium comprises one or more compounds selected from the group of compounds of the formulae II-1 to II-3, in R 2 , and has the meaning given in claim 5 for formula II.

8. A liquid-crystalline medium according to claim 1 or 2, wherein the medium comprises one or more compounds of the formula III selected from the group consisting of compounds of the formulae III-1 to III-6, in Z 31 and Z 32 represents, independently of each other, trans-CH=CH- or trans-CF=CF-, preferably trans-CH=CH-, and in formula III-6, alternatively, Z 31 and Z 32 One of them may represent -C≡C- and the other group has the meaning given under formula III in claim 1, R 3 represents an unfluorinated alkyl or alkoxy group having 1 to 7 C atoms or an unfluorinated alkenyl group having 2 to 7 C atoms, and One of them said And the others are expressed independently of each other in Alternatively, 9. A liquid-crystalline medium according to claim 1 or 2, wherein the medium comprises one or more compounds of the formula T, in R T Indicates halogen, CN, NCS, R F , R F -O- or R F -S-, where R F represents a fluorinated alkyl or fluorinated alkenyl group having up to 12 C atoms, and In each occurrence, they are expressed independently of each other L 4 and L 5 represents, identically or differently, F, Cl or a straight-chain, branched or cyclic alkyl or alkenyl group each having up to 12 C atoms; Z T3 , Z T4 represent, identically or differently, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, and t is 0 or 1.

10. A liquid-crystalline medium according to claim 1 or 2, wherein the medium comprises one or more compounds of the formula U, in R U represents H, alkyl or alkoxy having 1 to 12 C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 12 C atoms, wherein one or more CH2- groups may be replaced by Replacement, or represents the group R P , R P Indicates halogen, CN, NCS, R F , R F -O- or R F -S-, where R F represents a fluorinated alkyl or fluorinated alkenyl group having up to 9 C atoms, Z U1 , Z U2 represent, identically or differently, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, X 1 , X 2 , X 3 and X 4 Identically or differently represent Cl or F, t is 0 or 1, and and represents a group selected from the following group: a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L, excluding tetrafluoro-1,4-phenylene, b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, bicyclo[1.1.1]pentane-1,3-diyl, 4,4'-dicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl and spiro[3.3]heptane-2,6-diyl, wherein one or more non-adjacent CH2 groups may be replaced by -O- and / or -S-, and wherein one or more H atoms may be replaced by F, and c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may also be mono- or poly-substituted by L, wherein L, identically or differently on each occurrence, represents F, Cl, CN, SCN, SF5 or linear or branched, in each case optionally fluorinated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms.

11. A liquid-crystalline medium according to claim 1 or 2, wherein the medium comprises one or more compounds selected from the group consisting of compounds of the formulae U-1 to U-11, in L 1 , L 2 and L 3 represents, identically or differently, H, F, Cl, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl, and R U , X 1 , X 2 , X 3 and X 4 has the meaning given in claim 10.

12. A component for high frequency technology, characterized in that It comprises a liquid-crystalline medium according to any one of claims 1 to 11.

13. The component of claim 12, wherein the component is a liquid crystal based antenna component, a phase shifter, a tunable filter, a tunable metamaterial structure, a matching network, or a varactor diode.

14. A microwave antenna array, characterized in that It comprises one or more components according to claim 12 or 13.

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