heteroaromatic isothiocyanates

Abstract

The present invention relates to heteroaromatic isothiocyanates of formula (N) as defined in claim 1, to liquid crystalline media comprising one or more compounds of formula (N), and to high-frequency components comprising these media, in particular to microwave components for high-frequency devices, such as devices for changing the phase of microwaves, tunable filters, tunable metamaterial structures and electron beam steering antennas, such as phased array antennas.

Description

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

[0002] Liquid crystal media have been used for many years in electro-optical displays (liquid crystal displays: LCD) to display information. However, more recently, liquid crystal media have also been proposed for use in components for microwave technology, for example in DE 10 2004 029 429.1A 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”, 12MTC 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 the liquid-crystalline media in the relevant frequency range are discussed, and liquid-crystalline media based on mixtures of predominantly aromatic nitriles and isothiocyanates are shown.

[0005] In EP 2 982 730 A1, mixtures consisting entirely of isothiocyanate compounds are described.

[0006] Fluorine atoms are commonly used in mesogenic compounds to introduce polarity. In particular, in combination with terminal NCS groups, high dielectric anisotropy values ​​can be achieved.

[0007] However, compositions that can be used for microwave applications still have several disadvantages. There is a need to improve the general physical properties, shelf life, and stability of these media during operation 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 would be 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 liquid-crystalline media which have improved properties in connection with applications in the microwave range of the electromagnetic spectrum.

[0009] In order to solve this problem, a compound of the formula N shown below and a liquid crystal medium comprising the compound of the formula N are provided.

[0010] Therefore, the present invention relates to compounds of formula N

[0011]

[0012] in

[0013] R N represents H, an alkyl or alkoxy radical having 1 to 12 C atoms, or an alkenyl, alkenyloxy or alkoxyalkyl radical having 2 to 12 C atoms, wherein one or more CH2- radicals may be Replacement, or represents the group R P ,

[0014] R P Indicates halogen, CN, NCS, R F , R F -O- or R F -S-, where R F represents a fluorinated alkyl group having 1 to 9 C atoms or a fluorinated alkenyl group having 2 to 9 C atoms,

[0015] Z N1 and Z N2 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,

[0016] W represents N, CF or C-Cl,

[0017] X 1 and X 2 represent, identically or differently, H, Cl, F, methyl or ethyl,

[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, bicyclo-[1.1.1]pentane-1,3-diyl, 4,4′-bicyclohexylene, 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,

[0022] 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 polysubstituted by L,

[0023] L, on each occurrence, identically or differently, 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, and

[0024] n is 0, 1 or 2.

[0025] The present invention further relates to compounds of formula NH

[0026]

[0027] The radicals and parameters occurring therein have the meanings given above for the formula N,

[0028] And a method for synthesizing a compound of formula N from a compound of formula NH.

[0029] The present invention further relates to liquid-crystalline media comprising compounds of the formula N and to the use of liquid-crystalline media comprising compounds of the formula N in components for high-frequency technology.

[0030] According to another aspect of the invention, there is provided a component and a device comprising said component, both 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 adaptive filters.

[0031] Preferred embodiments of the invention are the subject matter of the dependent claims or can also be taken from the description.

[0032] Surprisingly, it has been found that by using compounds of the formula N in liquid-crystalline media, 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 can be obtained.

[0033] The media according to the present invention are characterized by a high clearing temperature, a broad nematic phase range and excellent low temperature stability (LTS). Therefore, devices containing the media can be operated under extreme temperature conditions.

[0034] The medium is also characterized by high dielectric anisotropy and low rotational viscosity. Consequently, the threshold voltage, or the minimum voltage at which the device can switch, is very low. Low operating voltage and threshold voltage are necessary for devices with improved switching characteristics and high energy efficiency. Low rotational viscosity enables fast switching of the devices of the present invention.

[0035] In particular, media comprising the compounds according to the invention are distinguished by very low dielectric losses.

[0036] These properties as a whole make the medium particularly suitable for components and devices for high-frequency technologies and applications in the microwave range, in particular devices for changing the phase of microwaves, tunable filters, tunable metamaterial structures and electronic beam steering antennas (e.g. phased array antennas).

[0037] In this context, “high-frequency technology” refers to the application 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.

[0038] As used herein, halogen is F, Cl, Br or I, preferably F or Cl, particularly preferably F.

[0039] In this context, alkyl is linear, branched or cyclic and has 1 to 15 C atoms, is preferably linear and, unless otherwise specified, 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.

[0040] In this context, the branched alkyl group is preferably isopropyl, s-butyl, isobutyl, isopentyl, 2-methylbutyl, 2-methylhexyl or 2-ethylhexyl.

[0041] As used herein, cycloalkyl refers to straight-chain or branched alkyl or alkenyl groups having up to 12 C atoms, preferably alkyl groups having 1 to 7 C atoms, in which the CH group is replaced by a carbocyclic ring having 3 to 5 C atoms, very preferably selected from cyclopropylalkyl, cyclobutylalkyl, cyclopentylalkyl and cyclopentenylalkyl.

[0042] In this context, alkoxy is straight-chain or branched and contains 1 to 15 C atoms. It is preferably straight-chain and, unless otherwise specified, has 1, 2, 3, 4, 5, 6 or 7 C atoms and is therefore preferably methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexyloxy or n-heptyloxy.

[0043] In this article, alkenyl is preferably an alkenyl with 2-15 C atoms, which is straight or branched and contains at least one C-C double bond. It is preferably straight and has 2-7 C atoms. Therefore, it is preferably vinyl, prop-1-enyl or prop-2-enyl, but-1-enyl, but-2-enyl or but-3-enyl, penta-1-enyl, penta-2-enyl, penta-3-enyl or penta-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, alkenyl can be E and / or Z isomer (trans / cis) form. Usually, preferred respective E isomers. Among the alkenyl groups, particular preference is given to prop-2-enyl, but-2- and -3-enyl, and pent-3- and -4-enyl.

[0044] In this context, alkynyl is an alkynyl radical having 2 to 15 C atoms, which is straight-chain or branched and contains at least one C—C triple bond. Preference is given to 1- and 2-propynyl and 1-, 2- and 3-butynyl.

[0045] In R F In the case of a fluorinated alkyl, alkoxy, alkenyl or alkenyloxy group, it may be branched or unbranched. Preferably, it is unbranched, mono-, poly- or perfluorinated, preferably perfluorinated, and has 1, 2, 3, 4, 5, 6 or 7 C atoms, in the case of an alkenyl group 2, 3, 4, 5, 6 or 7 C atoms.

[0046] R P Preferably, it 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.

[0047] The compounds of the general formula N are prepared by methods known per se, as described in the literature (e.g. in standard works such as Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Georg-Thieme-Verlag, Stuttgart), specifically under reaction conditions known and suitable for the described reactions. Variants known per se can be used here, but are not mentioned in greater detail here.

[0048] If desired, the starting materials can also be formed in situ by not isolating them from the reaction mixture, but by immediately reacting them further to give the compound of the general formula N.

[0049] The preferred synthetic route of the compounds of the present invention is illustrated in the scheme below and further illustrated by the examples. Suitable synthesis is also disclosed in, for example, Juanli Li, Jian Li, Minggang Hu, Zhaoyi Che, Lingchao Mo, Xiaozhe Yang, Zhongwei An & Lu Zhang (2017) The effect of locations of triple bond at terphenyl skeleton on the properties of isothiocyanate liquid crystals, Liquid Crystals, 44: 9, 1374-1383, and can be adapted to a specific desired compound of formula N by selecting suitable starting materials.

[0050] Preferred intermediates are 2-amino-5-bromopyrazine, 2-amino-5-bromo-3-fluoropyrazine, etc., all of which are described in the literature or can be obtained by synthetic procedures known to the skilled person.

[0051] The precursor 2-amino-5-bromopyrazine can be synthesized from pyrazine as shown in Scheme 1: iodination according to Dong, Zhi-Bing et al., Journal of Organometallic Chemistry, 695(5), 775-780; 2010, followed by amination as described by Jyothi, Boggavarapu and Madhavi, Nannapaneni, Asian Journal of Chemistry, 32(1), 84-90; 2020, gives aminopyrazine. Aminopyrazine is brominated with NBS, for example, according to Lizano, Enric et al., Synlett, 30(17), 2000-2003; 2019, to give 2-amino-5-bromopyrazine:

[0052] Solution 1

[0053]

[0054] 2-Fluoro-3-iodopyrazine (Scheme 2) is known from WO 2010 / 057121 and US 2010 / 0160280 and can also be converted into 2-amino-3-fluoropyrazine. Analogously to the method described in Scheme 1, 2-amino-5-bromo-3-fluoropyrazine is obtained:

[0055] Option 2

[0056]

[0057] Similarly, the isomeric 2-amino-5-bromo-6-fluoropyrazines (Scheme 3) were obtained from the known commercial product 2-amino-6-fluoropyrazine:

[0058] Option 3:

[0059]

[0060] Starting from the commercial product 2-cyano-3,6-difluoropyrazine, 2-amino-5-bromo-3,6-difluoropyrazine is synthesized, for example, in the method known from CN 105622526 A, as shown in Scheme 4, and then brominated as described above.

[0061] Option 4

[0062]

[0063] Fluorinated pyrazines can also be readily obtained by nucleophilic substitution of chlorine, as described in Schimler, Sydonie D. et al., Journal of Organic Chemistry, 80(24), 12137-12145; 2015:

[0064] Option 5

[0065]

[0066] The above precursors can be reacted with appropriate intermediates to give compounds of formula N or NH, for example by cross-coupling reactions commonly known as Suzuki, Stille, Sonogashira reactions, etc. Preferred pathways are illustrated in Schemes 6 and 7, wherein the radicals and parameters have the meanings defined in claim 1.

[0067] Option 6

[0068]

[0069] Option 7

[0070]

[0071] Preferred reagents for the process according to the invention for converting a compound of formula NH into a compound of formula N (Scheme 8) are carbon disulfide, thiophosgene, thiocarbonyldiimidazole, di-2-pyridylthiocarbonate, bis(dimethylthiocarbamoyl)disulfide, dimethylthiocarbamoyl chloride and phenylchlorothioformate, very preferably thiophosgene.

[0072] Option 8

[0073]

[0074] The reactions described above and below should be considered as illustrative only. A person skilled in the art can carry out corresponding variations of the syntheses described and can also follow other suitable synthetic routes to obtain compounds of formula N.

[0075] According to a first aspect of the present invention, there are provided compounds of formula N and its subformulae, wherein R N 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 Instead, preference is given to straight-chain or branched alkyl or alkenyl radicals having up to 12 C atoms, very preferably straight-chain or branched alkyl radicals having 1 to 7 C atoms.

[0076] According to a second aspect of the present invention, there are provided compounds of formula N and its subformulae, wherein the group R N Represents R P , where R P Indicates halogen, CN, NCS, R F 、R F -O- or R F -S-, and where R F represents a fluorinated alkyl or fluorinated alkenyl group having up to 9 C atoms, preferably a perfluorinated alkyl or perfluorinated alkenyl group having up to 9 C atoms, very preferably CF3 or OCF3, in particular OCF3.

[0077] The compound of formula N is preferably selected from formula N-1, N-2 and N-3:

[0078]

[0079] where R N 、 Z N1 , Z N2 、X 1 、X 2 and n have the corresponding meanings given above for formula N.

[0080] In formula N and its subformulas N-1, N-2 and N-3, preferably Express the same or different meanings on each occurrence

[0081] in

[0082] R L represents, identically or differently on each occurrence, H or an alkyl radical having 1 to 6 C atoms, preferably H, methyl or ethyl, particularly preferably H,

[0083] L represents F or an alkyl group having 1-6 C atoms, and

[0084] r is 0, 1, 2, 3, 4, 5 or 6, preferably 0 or 1,

[0085] in Alternatively expressed where R H Represents H or CH3.

[0086] In a preferred embodiment, the group X in formula N and its subformulas 1 and X 2 Both represent H.

[0087] In a preferred embodiment, the group X in formula N and its subformulas1 Represents H and group X 2 Indicates F or Cl.

[0088] In a preferred embodiment, the group X in formula N and its subformulas 1 represents F or Cl and group X 2 Indicates H.

[0089] In a preferred embodiment, the group X in formula N and its subformulas 1 and X 2 represents F or Cl, preferably both are F.

[0090] The compounds of the formulae N-1, N-2 and N-3 are preferably selected from the group consisting of formulae N-1-1 to N-1-12, N-2-1 to N-2-12 and N-3-1 to N-3-12:

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097] where R N 、X 1 and X 2 has the meanings given above and L, identically or differently on each occurrence, represents H, F, methyl, ethyl or cyclopropyl.

[0098] In a preferred embodiment, the medium according to the invention comprises a compound of the formula NI

[0099]

[0100] in

[0101] R N 、 Z N1 , Z N2 , W, X 1 、X 2 and n have the corresponding meanings given for formula N in claim 1 .

[0102] The compound of formula NI is preferably selected from the compounds of formula NI-1 and NI-2

[0103]

[0104] where R N , Z N1 , Z N2 、 has the meaning given above for formula N, Y 1 and Y 2 represents H, F or Cl identically or differently, and t is 0 or 1.

[0105] In the compound of formula NI or NI-1 or NI-2, Independently of each other, preferred representations

[0106] in

[0107] Alternatively expressed and

[0108] L 1 and L 2 represents, identically or differently, H, F, Cl or a linear, branched or cyclic alkyl or alkenyl group each having up to 12 C atoms.

[0109] In the compounds of formula NI or NI-1 or NI-2, Z N1 and Z N2 Identically or differently preferably represents -C≡C- or a single bond.

[0110] In a preferred embodiment of the present invention, the compounds of formula NI-1 and NI-2 are selected from the compounds of formula NI-1-1 to NI-1-12 and formula NI-2-1 to NI-2-12.

[0111]

[0112]

[0113]

[0114]

[0115] in

[0116] 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

[0117] R N 、Y 1 and Y 2have the meanings given above for formulae N-1 and N-2, and wherein very preferably the group It is expressed as follows:

[0118]

[0119]

[0120] In a preferred embodiment, in the compounds of formula NI and subformulae thereof, Y 1 and Y 2 One or two of them represent H, preferably both represent H.

[0121] In another preferred embodiment, in the compounds of formula N and its subformulae, Y 1 and Y 2 Both represent F.

[0122] In a preferred embodiment of the invention, the medium comprises one or more compounds selected from the group consisting of compounds of formulae I, II and III,

[0123]

[0124] in

[0125] R 1 represents H, a non-fluorinated alkyl or non-fluorinated alkoxy radical having 1 to 17, preferably 3 to 10, C atoms, or a non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl radical having 2 to 15, preferably 3 to 10, C atoms, wherein one or more CH2- radicals may be replaced by Instead, preferably a non-fluorinated alkyl or non-fluorinated alkenyl group,

[0126] n is 0, 1, or 2,

[0127] to

[0128] Each occurrence represents independently of each other

[0129]

[0130] where R L Each occurrence indicates H in the same or different way

[0131] or an alkyl radical having 1 to 6 C atoms, preferably H, methyl or ethyl, particularly preferably H,

[0132] and among them

[0133]

[0134] Alternatively expressed

[0135]

[0136] Preferred

[0137]

[0138] And in the case of n=2, One of the preferred representations and another preferred representation

[0139]

[0140] Preferred

[0141] to

[0142] Independently express

[0143]

[0144] More preferred

[0145] express

[0146] express

[0147] express

[0148] R 2 represents H, a non-fluorinated alkyl or non-fluorinated alkoxy radical having 1 to 17, preferably 3 to 10, C atoms, or a non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl radical having 2 to 15, preferably 3 to 10, C atoms, wherein one or more CH2- radicals may be replaced by Instead, preferably a non-fluorinated alkyl or non-fluorinated alkenyl group,

[0149] Z 21 represents trans-CH=CH-, trans-CF=CF- or -C≡C-, preferably -C≡C- or trans-CH=CH-, and

[0150] and

[0151] Independently express

[0152]

[0153] where R L Each occurrence indicates H in the same or different way

[0154] or an alkyl radical having 1 to 6 C atoms, preferably H, methyl or ethyl, particularly preferably H,

[0155] and among them

[0156] Preferably

[0157] and

[0158] Independently express

[0159]

[0160] Preferred representation

[0161]

[0162] and

[0163] Preferred representation

[0164]

[0165] More preferred

[0166]

[0167] R 3 represents H, a non-fluorinated alkyl or non-fluorinated alkoxy radical having 1 to 17, preferably 3 to 10, C atoms, or a non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl radical having 2 to 15, preferably 3 to 10, C atoms, wherein one or more CH2- radicals may be replaced by Instead, preferably a non-fluorinated alkyl group or a non-fluorinated alkenyl group,

[0168] Z 31 and Z 32 One, preferably Z 32 , represents trans-CH=CH-, trans-CF=CF- or -C≡C- and the other 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

[0169] to

[0170] Independently express

[0171]

[0172]

[0173] where R L Each occurrence indicates H in the same or different way

[0174] or an alkyl group having 1 to 6 C atoms, preferably H,

[0175] Methyl or ethyl, particularly preferably H,

[0176] and among them

[0177] Alternatively expressed

[0178]

[0179] Preferred

[0180] to

[0181] Independently express

[0182]

[0183] More preferred

[0184] express

[0185]

[0186] express

[0187] in particular

[0188] express

[0189] in particular

[0190] In the compounds of formula I, II and III, R L Preferably it represents H.

[0191] In another preferred embodiment, in the compounds of the formulae I, II and III, one or two radicals R L , preferably a group R L Different from H.

[0192] In a preferred embodiment of the present invention, the compound of formula I is selected from the compounds of formulae I-1 to I-5:

[0193]

[0194]

[0195] in

[0196] L 1 、L 2 and L 3 Each occurrence represents H or F, either identically or differently.

[0197] and the other groups have the corresponding meanings shown above for formula I, and

[0198] Preferably

[0199] R 1 represents a non-fluorinated alkyl group having 1 to 7 C atoms or a non-fluorinated alkenyl group having 2 to 7 C atoms.

[0200] The medium preferably comprises one or more compounds of the formula I-1, which are preferably selected from the compounds of the formulae I-1a to I-1d, preferably the compound of the formula I-1b:

[0201]

[0202] where R 1 has the meanings indicated above for formula I and preferably represents a non-fluorinated alkyl group having 1 to 7 C atoms or a non-fluorinated alkenyl group having 2 to 7 C atoms.

[0203] The medium preferably comprises one or more compounds of formula I-2, which are preferably selected from the compounds of formulae I-2a to I-2e, preferably compounds of formula I-2c:

[0204]

[0205]

[0206] where R 1 has the meanings indicated above for formula I and preferably represents a non-fluorinated alkyl group having 1 to 7 C atoms or a non-fluorinated alkenyl group having 2 to 7 C atoms.

[0207] The medium preferably comprises one or more compounds of the formula I-3, which are preferably selected from the compounds of the formulae I-3a to I-3d, particularly preferably compounds of the formula I-3b:

[0208]

[0209] where R 1 has the meanings indicated above for formula I and preferably represents a non-fluorinated alkyl group having 1 to 7 C atoms or a non-fluorinated alkenyl group having 2 to 7 C atoms.

[0210] The medium preferably comprises one or more compounds of the formula I-4, which are preferably selected from the compounds of the formulae I-4a to I-4e, particularly preferably those of the formula I-4b:

[0211]

[0212] where R 1 has the meanings indicated above for formula I and preferably represents a non-fluorinated alkyl group having 1 to 7 C atoms or a non-fluorinated alkenyl group having 2 to 7 C atoms.

[0213] The medium preferably comprises one or more compounds of the formula I-5, which are preferably selected from the compounds of the formulae I-5a to I-5d, particularly preferably the compound of the formula I-5b:

[0214]

[0215]

[0216] where R 1 has the meanings indicated above for formula I and preferably represents a non-fluorinated alkyl group having 1 to 7 C atoms or a non-fluorinated alkenyl group having 2 to 7 C atoms.

[0217] The medium preferably comprises one or more compounds of formula II, which are preferably selected from the compounds of formulae II-1 to II-3, preferably from the compounds of formulae II-1 and II-2:

[0218]

[0219] The radicals occurring therein have the meanings given above under formula II, and

[0220] Preferably

[0221] R 2 represents H, 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,

[0222] and

[0223] and One of them said

[0224]

[0225] and another independently expressed

[0226]

[0227] Preferred

[0228]

[0229] Best

[0230]

[0231] And preferably

[0232] R 2 Indicates C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0233] n represents an integer of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and

[0234] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0235] The compound of formula II-1 is preferably selected from the compounds of formulae II-1a to II-1e:

[0236]

[0237]

[0238] in

[0239] R 2 has the above meanings and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0240] n independently of one another represents an integer from 0 to 15, preferably from 1 to 7 and particularly preferably from 1 to 5, and

[0241] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0242] The compound of formula II-2 is preferably selected from the compounds of formula II-2a and II-2b:

[0243]

[0244] in

[0245] R 2 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,

[0246] n represents an integer of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and

[0247] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0248] The compound of formula II-3 is preferably selected from the compounds of formulae II-3a to II-3d:

[0249]

[0250]

[0251] in

[0252] R 2 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,

[0253] n represents an integer of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and

[0254] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0255] The compound of formula III is preferably selected from the compounds of formulae III-1 to III-6, more preferably selected from the compounds of formulae III-1, III-2, III-3 and III-4, and particularly preferably the compound of formula III-1:

[0256]

[0257] in

[0258] Z 31 and Z 32 represents, independently of one another, 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 above under formula III,

[0259] And preferably

[0260] R 3 represents H, 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,

[0261] and

[0262] to One, preferably express

[0263]

[0264] Preferred

[0265]

[0266] and other independent representations

[0267]

[0268] Preferred

[0269]

[0270] More preferred

[0271]

[0272] in

[0273] Alternatively expressed

[0274] And preferably

[0275] R 3 Indicates C n H 2n+1 or CH2=CH-(CH2) Z ,

[0276] n represents an integer of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and

[0277] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0278] The compound of formula III-1 is preferably selected from the compounds of formulae III-1a to III-1k, more preferably selected from the compounds of formulae III-1a, III-1b, III-1g and III-1H, particularly preferably formulae III-1b and / or III-1h:

[0279]

[0280]

[0281] in

[0282] R 3 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,

[0283] n represents an integer of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and

[0284] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0285] 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:

[0286]

[0287]

[0288]

[0289] in

[0290] R 3 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,

[0291] n represents an integer of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and

[0292] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0293] The compound of formula III-5 is preferably selected from the compounds of formula III-5a:

[0294]

[0295] R 3 has the meanings shown above for formula III5 and preferably represents C n H 2n+1 ,in

[0296] n represents an integer of 0-7, preferably 1-5.

[0297] 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 formulae IIA-1-1 to IIA-1-12, very preferably IIA-1-1 or IIA-1-2:

[0298]

[0299]

[0300]

[0301] in

[0302] R 1 represents an alkyl or alkenyl group having up to 7 C atoms, preferably ethyl, n-propyl, n-butyl or n-pentyl, n-hexyl,

[0303] R Lrepresents, 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, preferably methyl, ethyl, n-propyl, n-butyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclopent-1-enyl, very preferably ethyl,

[0304] And the compounds of formula II-1 are excluded.

[0305] Furthermore, in a certain embodiment which may be identical to or different from the previously preferred embodiments, the liquid-crystalline media according to the invention preferably comprise one or more compounds of the formula IV,

[0306]

[0307] in

[0308] express

[0309] s is 0 or 1, preferably 1, and

[0310] Preferred

[0311] express

[0312]

[0313] Especially preferred

[0314]

[0315] L 4 represents H or an alkyl group having 1 to 6 C atoms, a cycloalkyl group having 3 to 6 C atoms or a cycloalkenyl group having 4 to 6 C atoms, preferably CH3, C2H5, n-C3H7, i-C3H7, cyclopropyl, cyclobutyl, cyclohexyl, cyclopent-1-enyl or cyclohex-1-enyl, particularly preferably CH3, C2H5, cyclopropyl or cyclobutyl,

[0316] X 4 represents H, alkyl having 1 to 3 C atoms or halogen, preferably H, F or Cl, more preferably H or F and very particularly preferably F,

[0317] R 41 to R 44represents, independently of one another, a non-fluorinated alkyl or non-fluorinated alkoxy group each having 1 to 15 C atoms, a non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl group each having 2 to 15 C atoms, or a cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl group each having up to 15 C atoms, and alternatively, R 43 and R 44 One or both represent H,

[0318] Preferably

[0319] R 41 and R 42 independently of one another represent a non-fluorinated alkyl group or a non-fluorinated alkoxy group each having 1 to 7 C atoms, or a non-fluorinated alkenyl group, a non-fluorinated alkenyloxy group or a non-fluorinated alkoxyalkyl group each having 2 to 7 C atoms,

[0320] Particularly preferably

[0321] 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 each having 2 to 7 C atoms, and

[0322] Particularly preferably

[0323] R 42 represents a non-fluorinated alkyl group or a non-fluorinated alkoxy group each having 1 to 7 C atoms, and

[0324] Preferably

[0325] 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 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.

[0326] In a preferred embodiment of the present invention, the liquid-crystalline medium additionally comprises one or more compounds selected from the group consisting of compounds of the formulae V, VI, VII, VIII and IX:

[0327]

[0328] in

[0329] L51 Represents R 51 or X 51 ,

[0330] L 52 Represents R 52 or X 52 ,

[0331] R 51 and R 52 independently of one another represent H, a non-fluorinated alkyl or non-fluorinated alkoxy group having 1 to 17, preferably 3 to 10, C atoms or a non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl group having 2 to 15, preferably 3 to 10, C atoms, preferably an alkyl or non-fluorinated alkenyl group,

[0332] 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

[0333] to

[0334] Independently express

[0335]

[0336] Preferred

[0337]

[0338] L 61 Represents R 61 , and in Z 61 and / or Z 62 In the case of trans-CH=CH- or trans-CF=CF-, X is represented instead. 61 ,

[0339] L 62 Represents R 62 , and in Z 61 and / or Z 62 In the case of trans-CH=CH- or trans-CF=CF-, X is represented instead. 62 ,

[0340] R 61 and R 62independently of one another represent H, non-fluorinated alkyl or non-fluorinated alkoxy having 1 to 17, preferably 3 to 10, C atoms, or non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl having 2 to 15, preferably 3 to 10, C atoms, preferably alkyl or non-fluorinated alkenyl,

[0341] 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,

[0342] Z 61 and Z 62 one of them represents trans-CH=CH-, trans-CF=CF- or -C≡C- and the other independently 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

[0343] to

[0344] Independently express

[0345]

[0346] Preferred

[0347]

[0348] and

[0349] x represents 0 or 1;

[0350] L 71 Represents R 71 or X 71 ,

[0351] L 72 Represents R 72 or X 72 ,

[0352] R 71 and R 72 independently of one another represent H, non-fluorinated alkyl or non-fluorinated alkoxy having 1 to 17, preferably 3 to 10, C atoms or non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl having 2 to 15, preferably 3 to 10, C atoms, preferably alkyl or non-fluorinated alkenyl,

[0353] X 71 and X 72independently 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, a non-fluorinated or fluorinated alkenyloxy group or a non-fluorinated or fluorinated alkoxyalkyl group having 2 to 7 C atoms, preferably a fluorinated alkoxy group, a fluorinated alkenyloxy group, F or Cl, and

[0354] Z 71 to Z 73 Independently of each other, they represent trans-CH=CH-, trans-CF=CF-, -C≡C- or a single bond, preferably one or more of them represent a single bond, particularly preferably all of them represent a single bond and

[0355] to

[0356] Independently express

[0357]

[0358] Preferred

[0359]

[0360] R 81 and R 82 independently of one another represent H, non-fluorinated alkyl or alkoxy having 1 to 15, preferably 3 to 10, C atoms or non-fluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15, preferably 3 to 10, C atoms, preferably non-fluorinated alkyl or alkenyl,

[0361] Z 81 and Z 82 one of them represents trans-CH=CH-, trans-CF=CF- or -C≡C- and the other independently 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

[0362] express

[0363] and

[0364] Independently express

[0365]

[0366] L 91 Represents R 91 or X 91 ,

[0367] L 92Represents R 92 or X 92 ,

[0368] R 91 and R 92 independently of one another represent H, non-fluorinated alkyl or alkoxy having 1 to 15, preferably 3 to 10, C atoms or non-fluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15, preferably 3 to 10, C atoms, preferably non-fluorinated alkyl or alkenyl,

[0369] 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, a non-fluorinated or fluorinated alkenyloxy group or a non-fluorinated or fluorinated alkoxyalkyl group having 2 to 7 C atoms, preferably a fluorinated alkoxy group, a fluorinated alkenyloxy group, F or Cl, and

[0370] 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,

[0371] express

[0372]

[0373] to

[0374] Independently express

[0375]

[0376] 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 group consisting of the compounds of the formulae V-1 to V-3, preferably the formulae V-1 and / or V-2 and / or V-3, preferably the formulae V-1 and V-2:

[0377]

[0378] The radicals occurring therein have the corresponding meanings indicated above for formula V and are preferably

[0379] 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,

[0380] R 52represents 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,

[0381] X 51 and X 52 Independently of one another, they represent F, Cl, -OCF3, -CF3, -CN or -SF5, preferably F, Cl, -OCF3 or -CN.

[0382] 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:

[0383]

[0384] wherein the parameters have the corresponding meanings indicated above for formula V-1, and wherein

[0385] Y 51 and Y 52 represents in each case independently of one another H or F, and preferably

[0386] R 51 represents an alkyl or alkenyl group, and

[0387] X 51 It represents F, Cl or -OCF3.

[0388] The compound of formula V-2 is preferably selected from the compounds of formulae V-2a to V-2e and / or compounds of formulae V-2f and V-2g:

[0389]

[0390]

[0391] wherein in each case, the compound of formula V-2a is excluded from the compounds of formulae V-2b and V-2c, the compound of formula V-2b is excluded from the compounds of formula V-2c and the compound of formula V-2f is excluded from the compounds of formula V-2g, and

[0392] wherein the parameters have the corresponding meanings indicated above for formula V-1, and wherein

[0393] Y 51 and Y 52 represents in each case independently of one another H or F, and

[0394] Preferably

[0395] Y 51 and Y 52 represents H and the other represents H or F, preferably both represent H.

[0396] The compound of formula V-3 is preferably a compound of formula V-3a:

[0397]

[0398] wherein the parameters have the corresponding meanings indicated above for formula V-1, and wherein preferably

[0399] X 51 represents F, Cl, preferably F,

[0400] X 52 represents F, Cl or -OCF3, preferably -OCF3.

[0401] The compound of formula V-1a is preferably selected from the compounds of formula V-1a-1 and V-1a-2:

[0402]

[0403]

[0404] in

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

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

[0407] The compound of formula V-1b is preferably a compound of formula V-1b-1:

[0408]

[0409] in

[0410] R 51 Has the above meaning and preferably represents C n H 2n+1 , wherein n represents an integer of 1-7, preferably 1-6 and particularly preferably 3-5.

[0411] The compound of formula V-1c is preferably selected from the compounds of formulae V-1c-1 to V-1c-4, particularly preferably selected from the compounds of formulae V-1c-1 and V-1c-2:

[0412]

[0413] in

[0414] R 51 Has the above meaning and preferably represents C n H 2n+1 , wherein n represents an integer of 1-7, preferably 1-6 and particularly preferably 3-5.

[0415] The compound of formula V-1d is preferably selected from the compounds of formula V-1d-1 and V-1d-2, and the compound of formula V-1d-2 is particularly preferred:

[0416]

[0417] in

[0418] R 51 Has the above meaning and preferably represents C n H 2n+1 , wherein n represents an integer of 1-7, preferably 1-6 and particularly preferably 3-5.

[0419] The compound of formula V-2a is preferably selected from the compounds of formula V-2a-1 and V-2a-2, particularly preferably the compound of formula V-2a-1:

[0420]

[0421] in

[0422] R 51 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0423] R 52 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0424] n and m independently of one another represent an integer of 1 to 7, preferably 1 to 6 and particularly preferably 3 to 5, and

[0425] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0426] R 51 With R 52 Preferred combinations, particularly in the case of formula V-2a-1, are:

[0427] (C n H 2n+1 and C m H 2m+1 )、(C n H 2n+1 and OC m H 2m+1 )、(CH2=CH-(CH2) Z and C m H2m+1 )、(CH2=CH-(CH2) Z and OC m H 2m+1 ) and (C n H 2n+1 and (CH2) Z -CH=CH2).

[0428] Preferred compounds of formula V-2b are compounds of formula V-2b-1:

[0429]

[0430] in

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

[0432] R 52 Has the above meaning 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 of 1 to 7, preferably 1 to 6 and particularly preferably 3 to 5, and

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

[0435] Here R 51 With R 52 The preferred combination is especially C n H 2n+1 and C m H 2m+1 .

[0436] A preferred compound of formula V-2c is a compound of formula V-2c-1:

[0437]

[0438] in

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

[0440] R 52 Has the above meaning and preferably represents Cm H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

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

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

[0443] Here (R 51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ).

[0444] Preferred compounds of formula V-2d are compounds of formula V-2d-1:

[0445]

[0446] in

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

[0448] R 52 Has the above meaning 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 of 1 to 7, preferably 1 to 6 and particularly preferably 3 to 5, and

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

[0451] Here (R 51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ).

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

[0453]

[0454] in

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

[0456] R 52 Has the above meaning 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 of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

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

[0459] Here (R 51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and OC m H 2m+1 ).

[0460] Preferred compounds of formula V-2f are compounds of formula V-2f-1:

[0461]

[0462] in

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

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

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

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

[0467] Here (R51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 ).

[0468] A preferred compound of formula V-2g is a compound of formula V-2g-1:

[0469]

[0470] in

[0471] R 51 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0472] R 52 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0473] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0474] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0475] Here (R 51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ), particularly preferably (C n H 2n+1 and OC m H 2m+1 ).

[0476] The compound of formula VI is preferably selected from the compounds of formulae VI-1 to VI-5:

[0477]

[0478] in

[0479] 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,

[0480] And preferably

[0481] R 61 and R 62 independently of one another represent H, a non-fluorinated alkyl or alkoxy radical having 1 to 7 C atoms or a non-fluorinated alkenyl radical having 2 to 7 C atoms,

[0482] X 62 represents F, Cl, -OCF3 or -CN,

[0483] The compound of formula VI-1 is preferably selected from the compounds of formula VI-1a and VI-1b, more preferably selected from the compounds of formula VI-1a:

[0484]

[0485] in

[0486] R 61 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0487] R 62 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0488] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0489] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0490] Here (R 61 and R 62 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (Cn H 2n+1 and OC m H 2m+1 ), and in the case of Formula VI-1a, (C n H 2n+1 and C m H 2m+1 ) and in the case of formula VI-1b, particularly preferably (C n H 2n+1 and OC m H 2m+1 ).

[0491] The compound of formula VI-3 is preferably selected from the compounds of formulae VI-3a to VI-3e:

[0492]

[0493] wherein the parameters have the meanings given above under formula VI-3, and preferably

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

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

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

[0497] The compound of formula VI-4 is preferably selected from the compounds of formulae VI-4a to VI-4e:

[0498]

[0499] wherein the parameters have the meanings given above under formula VI-4, and preferably

[0500] R 61 Has the above meaning and preferably represents C n H 2n+1 ,in

[0501] n represents an integer of 1 to 7, preferably 1 to 5, and

[0502] X 62 represents F, Cl, OCF3, or -CN.

[0503] The compound of formula VI-5 is preferably selected from the compounds of formula VI-5a to VI-5d, preferably VI-5b:

[0504]

[0505]

[0506] wherein the parameters have the meanings given above under formula VI-5, and preferably

[0507] R 61 Has the above meaning and preferably represents C n H 2n+1 ,in

[0508] n represents an integer of 1 to 7, preferably 1 to 5, and

[0509] X 62 represents -F, -Cl, -OCF3, or -CN, particularly preferably -OCF3.

[0510] The compound of formula VII is preferably selected from the compounds of formulae VII-1 to VII-6:

[0511]

[0512]

[0513] wherein the compound of formula VII-5 is excluded from the compound of formula VII-6, and

[0514] wherein the parameters have the corresponding meanings indicated above for formula VII,

[0515] Y 71 、Y 72 、Y 73 represent H or F independently of each other,

[0516] And preferably

[0517] R 71 represents a non-fluorinated alkyl or alkoxy group each having 1 to 7 C atoms, or a non-fluorinated alkenyl group having 2 to 7 C atoms,

[0518] R 72 represents a non-fluorinated alkyl or alkoxy group each having 1 to 7 C atoms, or a non-fluorinated alkenyl group having 2 to 7 C atoms,

[0519] X 72 represents F, Cl, NCS or -OCF3, preferably F or NCS, and

[0520] Especially preferred

[0521] R 71 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0522] R72 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0523] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0524] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0525] The compound of formula VII-1 is preferably selected from the compounds of formulae VII-1a to VII-1d:

[0526]

[0527]

[0528] where X 72 has the meaning given above for Formula VII-2, and

[0529] R 71 Has the above meaning and preferably represents C n H 2n+1 ,in

[0530] n represents an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0531] z represents 0, 1, 2, 3 or 4, preferably 0 or 2, and

[0532] X 72 Preferably it represents F.

[0533] The compound of formula VII-2 is preferably selected from the compounds of formula VII-2a and VII-2b, particularly preferably formula VII-2a:

[0534]

[0535] in

[0536] R 71 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0537] R 72 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2)Z -CH=CH2, and wherein

[0538] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0539] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0540] Here (R 71 and R 72 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 ).

[0541] The compound of formula VII-3 is preferably a compound of formula VII-3a:

[0542]

[0543] in

[0544] R 71 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0545] R 72 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0546] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0547] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0548] Here (R 71 and R 72 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1and OC m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 ).

[0549] The compound of formula VII-4 is preferably a compound of formula VII-4a:

[0550]

[0551] in

[0552] R 71 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0553] R 72 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0554] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0555] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0556] Here (R 71 and R 72 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 ).

[0557] The compound of formula VII-5 is preferably selected from the compounds of formula VII-5a and VII-5b, more preferably formula VII-5a:

[0558]

[0559] in

[0560] R 71Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0561] R 72 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0562] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0563] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0564] Here (R 71 and R 72 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 ).

[0565] The compound of formula VII-6 is preferably selected from the compounds of formula VII-6a and VII-6b:

[0566]

[0567] in

[0568] R 71 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0569] R 72 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0570] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0571] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0572] Here (R 71 and R 72 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 ).

[0573] The compound of formula VII-7 is preferably selected from the compounds of formulae VII-7a to VII-7d:

[0574]

[0575] in

[0576] R 71 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,

[0577] X 72 Indicates F, -OCF3 or -NCS,

[0578] n represents an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0579] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0580] The compound of formula VIII is preferably selected from the compounds of formulae VIII-1 to VIII-3, more preferably these compounds of formula VIII consist predominantly thereof, even more preferably consist essentially thereof, very particularly preferably consist entirely thereof:

[0581]

[0582] in

[0583] Y 81 and Y 82 One of them represents H and the other represents H or F, and

[0584] R 81 Has the above meaning and preferably represents C n H 2n+1or CH2=CH-(CH2) Z ,and

[0585] R 82 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0586] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0587] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0588] Here (R 81 and R 82 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 ).

[0589] The compound of formula VIII-1 is preferably selected from the compounds of formulae VIII-1a to VIII-1c:

[0590]

[0591]

[0592] in

[0593] R 81 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0594] R 82 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0595] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0596] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0597] Here (R 81 and R 82 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 ).

[0598] The compound of formula VIII-2 is preferably a compound of formula VIII-2a:

[0599]

[0600] in

[0601] R 81 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0602] R 82 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0603] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0604] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0605] Here (R 81 and R 82 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ), (C n H 2n+1 and OC m H 2m+1 ) and (CH2=CH-(CH2) Z and C m H2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 ).

[0606] The compound of formula VIII-3 is preferably a compound of formula VIII-3a:

[0607]

[0608] in

[0609] R 81 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0610] R 82 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0611] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0612] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0613] Here (R 81 and R 82 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ).

[0614] The compound of formula IX is preferably selected from the compounds of formulae IX-1 to IX-3:

[0615]

[0616] wherein the parameters have the corresponding meanings indicated above under formula IX, and preferably

[0617] to one

[0618] express

[0619] and among them

[0620] R 91 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0621] R 92 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0622] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0623] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0624] Here (R 91 and R 92 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ).

[0625] The compound of formula IX-1 is preferably selected from the compounds of formulae IX-1a to IX-1e:

[0626]

[0627] wherein the parameters have the meanings given above and are preferably

[0628] R 91 Has the above meaning and preferably represents C n H 2n+1 ,and

[0629] n represents an integer of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and

[0630] X 92 Preferably it represents F or Cl.

[0631] The compound of formula IX-2 is preferably selected from the compounds of formula IX-2a and IX-2b:

[0632]

[0633] in

[0634] R 91 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0635] R 92 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0636] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0637] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0638] Here (R 91 and R 92 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ).

[0639] The compound of formula IX-3 is preferably a compound of formula IX-3a and IX-3b:

[0640]

[0641] in

[0642] R 91 Has the above meaning and preferably represents C n H 2n+1 or CH2=CH-(CH2) Z ,and

[0643] R 92 Has the above meaning and preferably represents C m H 2m+1 or OC m H 2m+1 or (CH2) Z -CH=CH2, and wherein

[0644] n and m independently of one another represent an integer of 1 to 7, preferably 2 to 6 and particularly preferably 3 to 5, and

[0645] z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0646] Here (R 91 and R 92) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and OC m H 2m+1 ), particularly preferably (C n H 2n+1 and OC m H 2m+1 ).

[0647] In a preferred embodiment of the present invention, the medium comprises one or more compounds of formula X

[0648]

[0649] in

[0650] R 101 represents H, an alkyl or alkoxy group having 1 to 15, preferably 3 to 10, C atoms or a non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl group having 2 to 15, preferably 3 to 10, C atoms, preferably an alkyl or alkenyl group,

[0651] 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,

[0652] Y 101 represents methyl, ethyl or Cl,

[0653] Y 102 represents H, methyl, ethyl, F or Cl, preferably H or F,

[0654] Z 101 , Z 102 Identical or different represent single bonds, -CH=CH-, -CF=CF- or -C≡C-,

[0655] and

[0656] Independently express

[0657]

[0658] Preferred

[0659]

[0660] and among them

[0661] Alternatively expressed and

[0662] n is 0 or 1.

[0663] Preferably, the compound of formula X is selected from the group consisting of subformulas X-1 and X-2

[0664]

[0665] The radicals and parameters occurring therein have the meanings given above for formula X.

[0666] Particularly preferably, the medium according to the invention comprises one or more compounds selected from the group consisting of compounds of the formulae X-1-1 to X-1-9

[0667]

[0668] where R 101 has the meaning given above for formula X.

[0669] In a preferred embodiment, the medium according to the invention comprises one or more compounds of the formula XI

[0670]

[0671] in

[0672] R S represents H, an alkyl or alkoxy radical having 1 to 12 C atoms, or an alkenyl, alkenyloxy or alkoxyalkyl radical having 2 to 12 C atoms, wherein one or more CH2- radicals may be substituted, and wherein one or more H atoms may be replaced by F,

[0673] and

[0674] Each occurrence represents independently of each other

[0675]

[0676] where R L represents, identically or differently on each occurrence, H, Cl or a linear, branched or cyclic alkyl radical having 1 to 6 C atoms,

[0677] L S1 、L S2 identically or differently represent H, Cl or F,

[0678] R S1 、R S2, identically or differently represent H, alkyl or alkenyl having up to 6 C atoms, or cyclopropyl, cyclobutyl, cyclopentenyl, or cyclopentyl,

[0679] R Th1 、R Th2 identically or differently represent H, alkyl or alkenyl or alkoxy having up to 6 C atoms, or cyclopropyl, cyclobutyl, cyclopentenyl or cyclopentyl,

[0680] Z S1 , Z S2 , Z S3 represents, identically or differently, -CH=CH-, -CH=CF-, -CF=CH-, -CF=CF-, -C≡C-, or a single bond,

[0681] a and b are the same or different and are 0 or 1.

[0682] Preferably, the compound of formula XI is selected from the compounds of formulae XI-1 to XI-24:

[0683]

[0684]

[0685]

[0686]

[0687] The radicals occurring therein have the meanings given above for formula XI and are preferably

[0688] R S represents an alkyl or alkenyl group having 2 to 6 C atoms, wherein one or more CH2- groups may be Alternative,

[0689] R S1 and R S2 Identically or differently represent H or an alkyl group having 1 to 6 C atoms, preferably H,

[0690] R S3 represents H, F or alkyl with up to 6 C atoms, or cyclopropyl, preferably H, F or ethyl, very preferably H,

[0691] L S1 and L S2 Identically or differently represents H or F, preferably F.

[0692] Preferably, the medium according to the invention comprises one or more compounds of formula T

[0693]

[0694] in

[0695] 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,

[0696]

[0697] Each occurrence represents independently of each other

[0698]

[0699] L 4 and L 5 represent, identically or differently, F, Cl or a linear, branched or cyclic alkyl or alkenyl group each having up to 12 C atoms;

[0700] Z T3 , Z T4 represents, identically or differently, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, and

[0701] t is 0 or 1.

[0702] In a preferred embodiment, the liquid-crystalline media according to the invention comprise one or more compounds selected from the compounds of the following formulae T-1a to T-3b:

[0703]

[0704] in

[0705] has the meaning given above and

[0706] n is 1, 2, 3, 4, 5, 6 or 7, preferably 1, 2, 3 or 4, particularly preferably 1.

[0707] In a particularly preferred embodiment of the present invention, the medium comprises one or more compounds selected from the group consisting of compounds of formulae T-1a and T-2a.

[0708] Preferably, the compound of formula T-1a is selected from the compounds having the following sub-formulas:

[0709]

[0710] wherein n is 1, 2, 3 or 4, preferably 1.

[0711] Preferably, the compound of formula T-2a is selected from the group consisting of the following sub-formulas:

[0712]

[0713]

[0714] wherein n is 1, 2, 3 or 4, preferably 1.

[0715] Very preferably, the medium according to the invention comprises one or more compounds of the formula T-1a-5.

[0716] In one embodiment, the medium according to the invention comprises one or more compounds of the formula N, NI, I, II, III, IV, V, VI, VII, VIII, IX, X, in which the radical R N ,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.

[0717] Very preferred compounds containing cyclic alkyl groups are selected from the compounds of formulae Cy-1 to Cy-14

[0718]

[0719]

[0720]

[0721] The medium according to the present 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 and -1 Up to 150μm -1 The range is preferably 10 μm -1 to 100μm -1In the case where the medium contains two or more chiral dopants, these chiral dopants may have HTP values ​​of opposite signs. This condition is preferred for some specific embodiments because it allows for a certain degree of compensation of the chirality of the individual compounds and can therefore be used to compensate for various temperature dependencies of the resulting medium in the device. However, it is generally preferred that the majority, and preferably all, of the chiral compounds present in the medium according to the present invention have HTP values ​​of the same sign.

[0722] Preferably, the chiral dopants present in the medium according to the present application are mesogenic compounds, and most preferably they themselves exhibit a mesophase.

[0723] In a preferred embodiment of the invention, the medium comprises two or more chiral compounds, all of which have the same algebraic sign of HTP.

[0724] The temperature dependence of the HTP of the individual compounds can be high or low. The temperature dependence of the pitch of the medium can be compensated by mixing compounds with different HTP temperature dependencies in corresponding proportions.

[0725] For the optically active component, a large number of chiral dopants are available to the person skilled in the art, some of which are commercially available, such as 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).

[0726] 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.

[0727] Suitable chiral groups are, for example, chiral branched hydrocarbon groups, chiral ethylene glycol, binaphthol or dioxolane, as well as monovalent or polyvalent chiral groups selected from sugar derivatives, sugar alcohols, sugar acids, lactic acid, chiral substituted diols, steroid derivatives, terpene derivatives, amino acids or several, preferably 1-5, amino acid sequences.

[0728] 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 dianhydrohexitols 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; chirally substituted diol groups such as mono- or oligoethylene glycol or propylene glycol; diols in which one or more CH2 groups are substituted by alkyl or alkoxy groups; amino acids such as alanine, valine, phenylglycine or phenylalanine, or sequences of 1 to 5 of these amino acids; steroid derivatives such as cholesteryl or cholic acid; terpene derivatives such as menthyl, neomenthyl, camphoryl, pineyl, terpinenyl, isolongifolenyl, fenchyl, carreyl, myrtyl, nopyl, geranyl, linaloyl, neryl, citronellyl or dihydrocitronellyl.

[0729] The medium according to the invention preferably contains a chiral dopant 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 34 779 and DE 35 34 780, DE 43 42 280, EP 01 038 941 and DE 195 41 820. Examples also include the compounds listed in Table F below.

[0730] The chiral compounds preferably used according to the invention are selected from the group consisting of the following formulae.

[0731] Particularly preferred are chiral dopants selected from the group consisting of compounds of the following formulae AI to A-III and A-Ch:

[0732]

[0733] in

[0734] R a11 、R a12 and R b12 independently of one another represent an alkyl radical having 1 to 15 C atoms, wherein additionally 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 connected to one another, and wherein additionally, 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 Different from R b12 ,

[0735] R a21 and R a22 independently of one another represent an alkyl radical having 1 to 15 C atoms, wherein additionally 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 all by alkyl, more preferably n-alkyl,

[0736] R a31 、R a32 and R b32 independently of one another represent straight-chain or branched alkyl radicals having 1 to 15 C atoms, wherein additionally 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 each other, and wherein in addition one or more H atoms may be replaced by F, Cl, Br, I or CN, preferably alkyl, more preferably n-alkyl, with the proviso that R a32 Different from R b32 ;

[0737] R z represents H, CH3, F, Cl, or CN, preferably H or F,

[0738] R 8 With R given above a11 one of the meanings of , preferably alkyl, more preferably n-alkyl having 1 to 15 C atoms,

[0739] Z 8 represents -C(O)O-, CH2O, CF2O or a single bond, preferably -C(O)O-,

[0740] A 11 As shown in the following A 12 defined, or alternatively expressed

[0741]

[0742] A 12 express

[0743] Preferred

[0744]

[0745] in

[0746] L 12 Each occurrence independently represents halogen, CN, or

[0747] Alkyl, alkenyl, alkoxy or alkenyloxy groups with more than 12 carbon atoms and

[0748] One or more H atoms are optionally replaced by halogen, preferably methyl, ethyl

[0749] , Cl or F, particularly preferably F,

[0750] A 21 express

[0751]

[0752] A 22 With A 12 The meaning given

[0753] A 31 With A 11 The meaning given, or alternatively

[0754]

[0755] A 32 With A 12 The meaning given.

[0756] n2 is 0, 1, or 2, either identically or differently, on each occurrence, and

[0757] n3 is 1, 2, or 3,

[0758] n4 is 0 or 1, preferably 0, and

[0759] r is 0, 1, 2, 3, or 4.

[0760] Particularly preferred are dopants selected from the group consisting of compounds of the following formulae:

[0761]

[0762]

[0763] in

[0764] m is an integer from 1 to 9, the same or different each time it appears.

[0765] n is an integer from 2 to 9, which may be the same or different each time it appears.

[0766] Particularly preferred compounds of formula A are compounds of formula A-III.

[0767] Further preferred dopants are derivatives of isosorbide, isomannide or isoidide of the following formula A-IV:

[0768]

[0769] Among them for:

[0770] (dianhydrosorbitol),

[0771] (dianhydromannitol), or

[0772] (dianhydroidinol),

[0773] Preferably dianhydrosorbitol,

[0774] and chiral glycols, such as diphenyl glycol (hydrobenzoin), in particular mesomorphic hydrogenated benzoin derivatives of the following formula AV:

[0775]

[0776] including the (S,S) enantiomer not shown,

[0777] in

[0778]

[0779] and

[0780] are each independently 1,4-phenylene, which may also be mono-, di- or tri-substituted by L, or 1,4-cyclohexylene,

[0781] L is H, F, Cl, CN or optionally halogenated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkoxycarbonyloxy having 1 to 7 C atoms,

[0782] c is 0, 1, or 2,

[0783] X is CH2 or -C(O)-,

[0784] Z 0 is -COO-, -OCO-, -CH2CH2- or a single bond, and

[0785] R 0 is alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkylcarbonyloxy having 1 to 12 C atoms.

[0786] Examples of compounds of formula IV are:

[0787]

[0788]

[0789] where R IV is alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkylcarbonyloxy having up to 12 C atoms.

[0790] Compounds of formula A-IV are described in WO 98 / 00428. Compounds of formula AV are described in GB-A-2,328,207.

[0791] 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.

[0792] Particularly preferred are chiral compounds of formula A-VI

[0793]

[0794] in

[0795] X 1 、X 2 、Y 1 and Y 2 Each independently of one another is 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 additionally, one or more non-adjacent CH2 groups may each independently of one another be replaced by -O-, -S-, -NH-, NR x-, -CO-, -COO-, -OCO-, -OCOO-, -S-CO-, -CO-S-, -CH=CH- or -C≡C-, replaced in such a way that O and / or S atoms are not directly bonded to one another, a polymerizable radical or a cycloalkyl or aryl radical having up to 20 C atoms, which may optionally be mono- or polysubstituted by halogen, preferably F, or by polymerizable radicals,

[0796] x 1 and x 2 are each independently 0, 1 or 2,

[0797] y 1 and y 2 are each independently 0, 1, 2, 3 or 4,

[0798] B 1 and B 2 are each independently an aromatic or partially or fully saturated aliphatic six-membered ring, in which one or more CH groups may each be replaced by N and one or more non-adjacent CH2 groups may each be replaced by O or S,

[0799] W 1 and W 2 Each is independently -(Z 1 -A 1 ) m1 -(Z 2 -A 2 ) m2 -R, and either one is R instead 1 or A 3 , but both are not H at the same time, or

[0800] for

[0801] or

[0802]

[0803] U 1 and U 2 are each independently CH2, O, S, CO or CS,

[0804] V 1 and V 2 Each independently of the other is (CH2) n , wherein 1-4 non-adjacent CH2 groups may each be replaced by O or S, and V 1 and V 2 One of them may represent a single bond, and in which

[0805] for In the case of , all are single bonds,

[0806] n is 1, 2, or 3

[0807] 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 groups, 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,

[0808] R x represents an alkyl group having 1 to 6 C atoms,

[0809] 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]octanylene, 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 bond,

[0810] 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,

[0811] m1 is 0 or 1,

[0812] m2 is independently 0, 1, or 2 at each occurrence,

[0813] and

[0814] R and R 1Each independently of one another is H, F, Cl, Br, I, CN, SCN, SF5, a straight-chain or branched alkyl group having 1 or 3-25 C atoms, which may be optionally monosubstituted or polysubstituted by F, Cl, Br, I or CN, and wherein 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.

[0815] Particularly preferred are chiral binaphthyl derivatives of formula A-VI-1

[0816]

[0817] wherein ring B represents 1,4-phenylene or 1,4-cyclohexylene, which is optionally mono- or poly-substituted by F, and R 0 represents an alkyl group having 1 to 7 C atoms,

[0818] Z 0 represents -O-, -COO-, -OCO-, -OCH2-, -CH2O-, -CH2CH2- or -CH=CH-, and b is 0, 1 or 2,

[0819] In particular those selected from the following formulae A-VI-1a to A-VI-1c:

[0820]

[0821] where R 0 and Z 0 has the meaning defined above and preferably

[0822] R 0 represents an alkyl group having 1 to 4 C atoms, and

[0823] Z 0 It is -OC(O)- or a single bond.

[0824] The concentration of the one or more chiral dopants in the LC medium is preferably from 0.001% to 20%, preferably from 0.05% to 5%, more preferably from 0.1% to 2%, and most preferably from 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 having the same or similar HTP. For chiral dopants having a higher or lower absolute HTP value than S-4011, these preferred concentrations must be proportionally reduced or increased, respectively, depending on the ratio of their HTP value relative to that of S-4011.

[0825] The pitch p of the LC medium or host mixture according to the invention is preferably 5-50 μm, more preferably 8-30 μm, particularly preferably 10-20 μm.

[0826] Preferably, the medium according to the invention comprises a stabilizer selected from the compounds of formulae ST-1 to ST-19.

[0827]

[0828]

[0829]

[0830]

[0831]

[0832] in

[0833] R ST represents H, alkyl or alkoxy having 1 to 15 C atoms, wherein additionally one or more CH2 groups in these groups may each independently of one another be replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O-, -O-CO- are replaced in such a way that the O atoms are not directly connected to one another, and wherein additionally one or more H atoms may be replaced by halogen,

[0834] express

[0835]

[0836]

[0837] 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,

[0838] L 1 and L 2 each independently represents F, Cl, CF3 or CHF2,

[0839] p represents 1 or 2, and

[0840] q means 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0841] Among the compounds of formula ST, the compounds of formula

[0842]

[0843]

[0844] wherein n=1, 2, 3, 4, 5, 6 or 7, preferably n=1 or 7

[0845]

[0846] wherein n=1, 2, 3, 4, 5, 6 or 7, preferably n=3

[0847]

[0848] wherein n=1, 2, 3, 4, 5, 6 or 7, preferably n=3

[0849]

[0850]

[0851] In the compounds of formulae ST-3a and ST-3b, n preferably represents 3. In the compound of formula ST-2a, n preferably represents 7.

[0852] 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:

[0853]

[0854]

[0855] The compounds of the formulae ST-1 to ST-19 are preferably each present in the liquid-crystal mixture according to the invention in an amount of 0.005 to 0.5%, based on the mixture.

[0856] If the mixtures according to the invention comprise two or more compounds selected from the compounds of the formulae ST-1 to ST-19, the concentration is correspondingly increased to 0.01 to 1% in the case of two compounds, based on the mixture.

[0857] However, the total proportion of the compounds of the formulae ST-1 to ST-18, based on the mixture according to the invention, should not exceed 2%.

[0858] Other mesogenic compounds not explicitly mentioned above can also optionally and advantageously be used in the media according to the invention. These compounds are known to those skilled in the art.

[0859] In a preferred embodiment of the present invention, the total concentration of compounds of the formula N in the liquid-crystalline medium is 5% or more, preferably 7% or more, very preferably 9% or more.

[0860] In a preferred embodiment of the present invention, the liquid-crystalline medium preferably comprises in total 2% to 50%, more preferably 5% to 45%, very preferably 7% to 40% and in particular 8% to 35% of compounds of the formula N.

[0861] In a preferred embodiment of the present invention, the liquid-crystalline medium preferably comprises in total 2% to 55%, more preferably 5% to 50%, very preferably 7% to 45% and in particular 8% to 40% of compounds of the formulae N and NI.

[0862] In a preferred embodiment of the present invention, the liquid-crystalline medium comprises a total of 5% to 45%, preferably 10% to 40%, particularly preferably 15% to 35% of one or more compounds of the formula T, preferably selected from the formulae T-1a and T-2a, very preferably selected from T-1a-5 and T-2a-4.

[0863] In a preferred embodiment of the present invention, the liquid-crystalline medium comprises in total 5% to 35%, preferably 10% to 30%, particularly preferably 15% to 25%, of one or more compounds of the formula T-1a.

[0864] In a preferred embodiment of the invention, the liquid-crystalline media comprise a total of 5% to 35%, preferably 10% to 30%, particularly preferably 15% to 25%, of one or more compounds of the formula T-1a and a further 5% to 15% of one or more compounds of the formula T-2a-4.

[0865] In a preferred embodiment, the medium comprises one or more compounds of formula I, preferably formula I-2 or I-3, in a total concentration of 1% to 25%, more preferably 2% to 20%, particularly preferably 5% to 15%.

[0866] In a preferred embodiment of the present invention, the medium comprises one or more compounds of the formula II, preferably compounds of the formula II-1, in a total concentration of 5% to 35%, more preferably 10% to 30%, particularly preferably 15% to 25%.

[0867] 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%.

[0868] 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.

[0869] 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-1h and / or III-1b, in a total concentration of 15%-70%, more preferably 25%-60%, particularly preferably 35%-50%.

[0870] In a preferred embodiment, the medium comprises one or more compounds of formula N and I and II and / or IIA and III and T, preferably in a total concentration of 90% or more, more preferably 95%, 96% or 97% or more, very preferably 98% or more, in particular 99% or more.

[0871] In a preferred embodiment, the medium comprises one or more compounds of formula N and I and II and / or IIA and III and T and NI, preferably in a total concentration of 90% or more, more preferably 95%, 96% or 97% or more, very preferably 98% or more, in particular 99% or more.

[0872] In a preferred embodiment, the medium comprises one or more compounds of formula N and II and III and T, preferably in a total concentration of 90% or more, more preferably 95%, 96% or 97% or more, very preferably 98% or more, in particular 99% or more.

[0873] In a preferred embodiment, the medium comprises one or more compounds of formula N and I and III and T, preferably in a total concentration of 90% or more, more preferably 95%, 96% or 97% or more, very preferably 98% or more, in particular 99% or more.

[0874] Further preferred embodiments of the present invention, alone or in combination with one another, are as follows, wherein some of the compounds are abbreviated using the acronyms given in Table C below:

[0875] - the medium comprises one, two, three, four or more compounds of formula III-1, preferably selected from the group consisting of compounds of formula III-1b, III-1f and III-1h; more preferably III-1b and III-1h;

[0876] - the medium contains the compound of formula III-1b, preferably in a total concentration of 5% to 35%, more preferably 10% to 30%, in particular 15% to 25%;

[0877] - the medium contains the compound of formula III-1h, preferably in a total concentration of 10% to 40%, more preferably 15% to 35%, in particular 18% to 30%;

[0878] - the medium contains the compounds PPU-TO-S and / or PPTU-TO-S and / or PTPU-TO-S and / or PP(1)TO-nS;

[0879] - 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;

[0880] - the medium contains one or more compounds of formula I-2d and formula II-1b, preferably compounds PGU-3-S and / or PGU-4-S and PTU-3-S and / or PTU-4-S and / or PTU-5-S;

[0881] - the medium contains one or more compounds of formula PPTU-nS and / or PTPU-nS in a total concentration of 15% to 25%;

[0882] - 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 of 15-30%;

[0883] 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 of 0.01-1%, preferably 0.05-0.5%, in particular 0.10-0.15%.

[0884] 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.

[0885] 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.

[0886] 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, 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.

[0887] 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, very preferably 10 or more.

[0888] The liquid-crystal medium according to the invention has a peak at 589 nm (Na D ) and the birefringence (Δn) at 20° C. are preferably 0.280 or greater, more preferably 0.300 or greater, even more preferably 0.320 or greater, very preferably 0.330 or greater, and particularly 0.350 or greater.

[0889] The liquid-crystal medium according to the invention has a peak at 589 nm (Na D ) and Δn at 20° C. are preferably from 0.200 to 0.900, more preferably from 0.250 to 0.800, even more preferably from 0.300 to 0.700, very particularly preferably from 0.350 to 0.600.

[0890] In a preferred embodiment of the present application, the Δn of the liquid-crystalline media according to the invention is preferably 0.50 or greater, more preferably 0.55 or greater.

[0891] The compounds of 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.

[0892] The compounds of formulae N, I, II and III are preferably dielectrically positive.

[0893] In this application, the expression dielectric positivity describes compounds or components in which Δε>3.0, dielectric neutrality describes compounds or components in which -1.5≤Δε≤3.0, and dielectric negativity describes compounds or components in which Δε<-1.5. Δε is measured at a frequency of 1 kHz and at 20°C. The dielectric anisotropy of each compound is determined from the results of a 10% solution of each individual compound in a nematic host mixture. If the solubility of the corresponding compound in the host mixture is less than 10%, the concentration is reduced to 5%. The capacitance of the test mixture is measured in a box with homeotropic alignment and in a box with planar alignment. The cell thickness of both types of cells 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 below the capacitance threshold of the corresponding test mixture.

[0894] Δε is defined as (ε||-ε ⊥ ), and ε ave. =(ε||+2ε ⊥ ) / 3.

[0895] The host mixture used for extrapolation determination of the physical constants of the pure compounds was ZLI-4792 from Merck KGaA (Germany). The absolute values ​​of the dielectric constant, birefringence (Δn), and rotational viscosity (γ1) of the compounds were determined from the changes in the respective values ​​of the host mixture upon addition of the compound. The concentration in the host was 10% or, in the case of insufficient solubility, 5%. These values ​​were extrapolated to a concentration of 100% of the added compound.

[0896] In the examples, the phase sequences of the pure compounds are given using the following abbreviations:

[0897] K: crystalline, N: nematic, SmA: smectic A, SmB: smectic B, I: isotropic.

[0898] The component having a nematic phase at a measurement temperature of 20° C. was measured as it was, and all other components were treated like compounds.

[0899] Unless otherwise expressly stated, in all cases in this application the expression "threshold voltage" refers to the optical threshold and is given for a 10% relative contrast ratio (V 10 ) and the expression "saturation voltage" refers to the optical saturation and is for 90% relative contrast (V 90 ) is referenced by the capacitive threshold voltage (V0), also known as the Freedericks threshold (V Fr ), only used when explicitly mentioned.

[0900] Unless expressly stated otherwise, parameter ranges indicated in this application include the limit values.

[0901] The different upper and lower value limits indicated for the various property ranges give rise to further preferred ranges in combination with one another.

[0902] Throughout the application, the following conditions and definitions apply unless expressly stated otherwise. All concentrations are quoted in percent by weight and relate to the corresponding mixture as a whole. All temperatures are quoted in degrees Celsius and all temperature differences are quoted in differential degrees. All physical properties are determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals", Status Nov. 1997, Merck KGaA (Germany) and are quoted at a temperature of 20°C unless otherwise stated. The optical anisotropy (Δn) is measured at a wavelength of 589.3 nm. The dielectric anisotropy (Δε) is measured at a frequency of 1 kHz. The threshold voltage and all other electro-optical properties are measured using a test cell produced by Merck KGaA, Germany. The test cell used to determine Δε has a cell thickness of approximately 20 μm. The electrodes are 1.13 cm 2The circular ITO electrode with the same area and guard ring. For the homeotropic orientation (ε||), the alignment layer is SE-1211 from Nissan Chemicals, Japan; for the axial orientation (ε ⊥ ), the alignment layer was polyimide AL-1054 from Synthetic Rubber (Japan). A Solatron 1260 frequency response analyzer was used with a voltage of 0.3 V. rms The capacitance is measured with a sine wave. The light used in the electro-optical measurement is white light. A device using a commercially available DMS instrument from Autronic-Melchers, Germany, is used here. The characteristic voltage is measured under vertical observation. The threshold values ​​(V 10 )、Medium Gray(V 50 ) and saturation (V 90 )Voltage.

[0903] For example, "Cavity Perturbation Method for Characterization of Liquid Crystals up to 35GHz" by A.Penirschke et al., 34 th The properties of liquid crystal media in the microwave frequency range are investigated, as described in the European Microwave Conference - Amsterdam, pp. 545-548. Also in this context are 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 029429 A, which also describe measurement methods in detail.

[0904] Liquid crystals were introduced into polytetrafluoroethylene (PTFE) or quartz capillaries. The capillaries had an inner diameter of 0.5 mm and an outer diameter of 0.78 mm. The effective length was 2.0 cm. The filled capillary was introduced into the center of a cylindrical cavity with a resonant frequency of 19 GHz. The cavity had a length of 11.5 mm and a radius of 6 mm. An input signal (source) was then applied, and the frequency-dependent response of the cavity was recorded using a commercial vector network analyzer (N5227A PNA Microwave Network Analyzer, Keysight Technologies Inc. USA). For other frequencies, the cavity dimensions were adjusted accordingly.

[0905] The changes in the resonance frequency and the Q factor between the measurement with the capillary filled with liquid crystal and the measurement without the capillary filled with liquid crystal are used to calculate the resonant frequency and the Q factor of the capillary filled with liquid crystal by the above-mentioned publication A. Penirschke et al., 34 th Equations 10 and 11 in the European Microwave Conference—Amsterdam, pp. 545-548, are used to determine the dielectric constant and loss angle at the corresponding target frequency, as described therein.

[0906] The values ​​of the characteristic components perpendicular and parallel to the liquid crystal director are obtained by aligning the liquid crystal in a magnetic field using a permanent magnet with a magnetic field strength of 0.35 Tesla.

[0907] Preferred components are phase shifters, varactor diodes, wireless and radio wave antenna arrays, matching circuits adaptive filters, etc.

[0908] In this application, unless expressly stated otherwise, the expression "compound" refers to both one compound and a plurality of compounds.

[0909] All mixtures according to the present invention are nematic. The liquid-crystalline media according to the present invention preferably have a nematic phase within the preferred ranges given above. The expression "having a nematic phase" here means, on the one hand, that no smectic phase or crystallization is observed at low temperatures at the corresponding temperature, and, on the other hand, that no clearing occurs upon heating from the nematic phase. At elevated temperatures, the clearing point is measured in a capillary tube by conventional methods. Low-temperature studies are performed in a flow viscometer at the corresponding temperature and checked by storing a large number of samples: the storage stability (LTS) of the media according to the present invention in bulk at a given temperature T is determined by visual inspection. 2 g of the medium of interest are filled into closed, appropriately sized glass containers (bottles) and placed in a refrigerator at a predetermined temperature. The bottles are checked at specified time intervals for the appearance of smectic phases or crystallization. Two bottles are stored for each material and at each temperature. If the appearance of crystallization or a smectic phase is observed in at least one of the two corresponding bottles, the test is terminated, and the time of the last check before the appearance of a more ordered phase is recorded as the corresponding storage stability. The test was finally terminated after 1000 h, ie an LTS value of 1000 h means that the mixture was stable at the given temperature for at least 1000 h.

[0910] The liquid crystals used preferably have a positive dielectric anisotropy of preferably 2 or more, preferably 4 or more, particularly preferably 6 or more, very particularly preferably 10 or more.

[0911] Furthermore, the liquid-crystalline media according to the invention are characterized by high anisotropy values ​​in the microwave range. The birefringence at approximately 19 GHz is, for example, preferably 0.14 or greater, particularly preferably 0.15 or greater, particularly preferably 0.20 or greater, particularly preferably 0.25 or greater, and very particularly preferably 0.30 or greater. Furthermore, the birefringence is preferably 0.80 or less.

[0912] The dielectric anisotropy in the microwave range is defined as

[0913] Δε r ≡(ε r,|| -ε r,⊥ ).

[0914] Adjustability (τ) is defined as

[0915] τ≡(Δε r / ε r,|| ).

[0916] The material mass (η) is defined as

[0917] η≡(τ / tanδ εr,max. ),in

[0918] The maximum dielectric loss is

[0919] tanδεr,max. ≡max.{tanδ εr,⊥, tanδ εr,||}.

[0920] 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, in particular 0.350 or more.

[0921] Preferred liquid crystal materials have a material mass (η) of 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, very particularly preferably 30 or more.

[0922] In the corresponding components, preferred liquid crystal materials have a phase shifter quality of 15° / dB or higher, preferably 20° / dB or higher, preferably 30° / dB or higher, preferably 40° / dB or higher, preferably 50° / dB or higher, particularly preferably 80° / dB or higher, very particularly preferably 100° / dB or higher.

[0923] However, in some embodiments, liquid crystals with negative dielectric anisotropy may also be advantageously used.

[0924] The liquid crystals used are individual substances or mixtures. They preferably have a nematic phase.

[0925] The liquid-crystalline media according to the invention may contain other additives and chiral dopants in customary concentrations. The total concentration of these other ingredients, based on the entire mixture, is 0% to 10%, preferably 0.1% to 6%. The concentration of the individual compounds used is preferably 0.1% to 3%. The concentrations of these and similar additives are not taken into account when quoting values ​​and concentration ranges for the liquid-crystalline components and liquid-crystalline compounds of the liquid-crystalline media in this application.

[0926] 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 0.05% to 15%, more preferably 1% to 10%, most preferably 2% to 6%.

[0927] Optionally, the media according to the invention may contain additional liquid crystal compounds to adjust the physical properties. These compounds are known to those skilled in the art. Their concentration in the media according to the invention is preferably 0% to 30%, more preferably 0.1% to 20%, and most preferably 1% to 15%.

[0928] Response time is expressed as rise time (τ on) are given as the relative tuning change time (t 90 -t0), including the delay time (t 10 -t0), with decay time (τ off ) are given as the relative tuning change time (t 100 -t 10 ) and as the total response time (τ total =τ on +τ off ) is given.

[0929] 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. Typically, the desired amount of the compound used in the smaller amount is dissolved in the compound used in the larger amount. Completion of the dissolution process is particularly easily observed if the temperature is above the clearing point of the compound used in the higher concentration. However, the medium can also be prepared in other conventional ways, for example using so-called premixes, which can be, for example, homologous or eutectic mixtures of the compounds, or using so-called "multi-bottle" systems, the components of which are themselves ready-to-use mixtures.

[0930] All temperatures, such as the melting point of liquid crystals 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 T(N,I), are expressed in degrees Celsius. All temperature differences are expressed in differential degrees.

[0931] In the present invention, and in particular in the following examples, the structures of the mesogenic compounds are represented by abbreviations, also called acronyms. In these acronyms, the chemical formulae are abbreviated as follows using Tables A to D below. All groups C n H 2n+1 , C m H 2m+1 and C l H 2l+1 , and C n H 2n , C m H 2m and C l H 2l represents a straight-chain alkyl or alkylene group, respectively. In each case, there are n, m, or 1 carbon atoms, where n and m are independently 1, 2, 3, 4, 5, 6, or 7, and l is 1, 2, or 3. Table A lists the codes for the ring elements of the core structure of the compound, while Table B shows the linking groups. Table C gives the code meanings for the left-hand or right-hand end groups. Table D shows exemplary structures of the compounds and their respective abbreviations.

[0932] Table A: Ring Elements

[0933]

[0934]

[0935]

[0936]

[0937]

[0938]

[0939]

[0940] Table B: Linking Groups

[0941]

[0942] Table B: End Groups

[0943]

[0944]

[0945] Use in combination with other

[0946]

[0947] wherein n and m each represent an integer, and the three dots "..." are placeholders for other abbreviations from the table.

[0948] The side groups of the branches are numbered starting from the position next to the longest chain ring (1). The smaller number indicates the length of the branch. The superscript number in brackets indicates the position of the branch. For example:

[0949]

[0950] The following table shows exemplary structures and their corresponding abbreviations. These are for the purpose of illustrating the meaning of the abbreviation rules. They also represent preferred compounds for use.

[0951] Table C: Example Structure

[0952] The following exemplary structures are compounds that are preferably additionally used in the medium:

[0953]

[0954]

[0955]

[0956]

[0957]

[0958]

[0959]

[0960]

[0961]

[0962]

[0963]

[0964]

[0965]

[0966]

[0967]

[0968]

[0969] wherein m and n are the same or different and are 1, 2, 3, 4, 5, 6 or 7.

[0970] Preferably, the medium according to the invention comprises one or more compounds chosen from the compounds of Table C.

[0971] The following table, Table D, shows exemplary compounds that can be used as alternative stabilizers in the mesomorphic medium according to the present invention. The total concentration of these and similar compounds in the medium is preferably 5% or less.

[0972] Table D

[0973]

[0974]

[0975]

[0976] In a preferred embodiment of the present invention, the mesogenic medium comprises one or more compounds selected from the group consisting of compounds of Table D.

[0977] The following table, Table E, shows exemplary compounds that may be preferably used as chiral dopants in the mesogenic medium according to the present invention.

[0978] Table E

[0979]

[0980]

[0981]

[0982] In a preferred embodiment of the present invention, the mesogenic medium comprises one or more compounds selected from the group consisting of compounds of Table E.

[0983] The mesogenic medium according to the present application preferably comprises two or more, preferably four or more, compounds selected from the group consisting of the compounds from the above table. Example

[0984] The following examples illustrate the present invention but do not limit it in any way.

[0985] For a person skilled in the art, it is clear from the physical properties which properties can be achieved and within what range they can be varied. In particular, the combinations of various properties that can preferably be achieved are therefore well defined for a person skilled in the art.

[0986] Synthesis Example

[0987] abbreviation:

[0988] RT Room temperature (20℃±1℃)

[0989] MTB ether tert-butyl methyl ether

[0990] DABCO 1,4-diazabicyclo[2.2.2]octane

[0991] dist. distilled

[0992] THF Tetrahydrofuran

[0993] XPhos 2-Dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl

[0994] XPhos Pd G2 Chloro(2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl)[2-(2'-amino-1,1'-biphenyl)palladium(II)

[0995] Synthesis Example 1: 2-[4-(4-Butylcyclohexyl)phenyl]-5-isothiocyanatopyrazine

[0996] Step 1.1: 5-[4-(4-Butylcyclohexyl)phenyl]pyrazin-2-amine

[0997]

[0998] Under an argon atmosphere, a mixture of [4-(4-butylcyclohexyl)phenyl]boronic acid (CAS 516510-90-0, 6.0 g, 23 mmol), 5-bromopyrazin-2-amine (CAS 59489-71-3, 4.0 g, 23 mmol), and potassium carbonate (6.4 g, 46 mmol) in distilled water (20 ml) and 1,4-dioxane (80 ml) was treated with [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II)-dichloromethane complex (1.0 g, 1 mmol). The reaction mixture was stirred at 90°C overnight. It was then cooled to room temperature and filtered through Celite. The filtrate was diluted with MTB ether and distilled water was added. The aqueous phase was separated and extracted with MTB ether. The combined organic phases were washed with brine, dried (sodium sulfate), filtered, and concentrated in vacuo. The residue was purified by silica gel chromatography (MTB ether) to give 5-[4-(4-butylcyclohexyl)phenyl]pyrazin-2-amine as yellow crystals.

[0999] Step 1.2: 2-[4-(4-Butylcyclohexyl)phenyl]-5-isothiocyanatopyrazine

[1000]

[1001] At 0 ° C, under an argon atmosphere, thiophosgene (2.1 ml, 27 mmol) was slowly added to a solution of 5-[4-(4-butylcyclohexyl)phenyl]pyrazine-2-amine (6.8 g, 22 mmol) and DABCO (6.2 g, 55 mmol) in dichloromethane (230 ml). The reaction mixture was stirred at room temperature overnight. 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 (1-chlorobutane) and crystallized (heptane) to obtain 2-[4-(4-butylcyclohexyl)phenyl]-5-isothiocyanatopyrazine as yellow crystals.

[1002] Phase sequence

[1003] K 99SmA 134N 233I.

[1004] Δε=8.9

[1005] Δn=0.3189

[1006] Synthesis Example 2:2-[2-(4-Butylphenyl)ethynyl]-5-isothiocyanatopyrazine

[1007] Step 2.1: 5-[2-(4-Butylphenyl)ethynyl]pyrazin-2-amine

[1008]

[1009] Under argon atmosphere, a solution of 1-butyl-4-ethynyl-benzene (CAS 79887-09-5, 5.1 g, 32 mmol), 5-bromopyrazin-2-amine (CAS 59489-71-3, 5.0 g, 28.7 mmol) and diisopropylamine (70 ml) in THF (70 ml) was treated with copper (I) iodide (5.5 mg), chloro(2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl)(2'-amino-1,1'-biphenyl-2-yl)palladium (II) (46 mg) and 2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl (28 mg) at room temperature. The reaction mixture was stirred at 70 ° C overnight. It was then cooled to room temperature and concentrated in vacuo. The residue was purified by silica gel chromatography (heptane and dichloromethane) to give 5-[2-(4-butylphenyl)ethynyl]pyrazin-2-amine as a brown solid.

[1010] Step 2.2: 2-[2-(4-Butylphenyl)ethynyl]-5-isothiocyanatopyrazine

[1011]

[1012] A solution of 5-[2-(4-butylphenyl)ethynyl]pyrazin-2-amine (7.8 g, 31 mmol) and DABCO (10.4 g, 93 mmol) in dichloromethane (100 ml) was cooled to 0°C and treated with thiophosgene (3.7 ml, 47 mmol). The suspension was stirred overnight at room temperature. It was then hydrolyzed with distilled water and brine, dried (sodium sulfate) and concentrated in vacuo. The residue was purified by silica gel chromatography (heptane and dichloromethane) and crystallization (heptane). 2-[2-(4-butylphenyl)ethynyl]-5-isothiocyanatopyrazine was isolated as a beige solid.

[1013] Phase sequence:

[1014] K 67N 72I.

[1015] Δε=10.3

[1016] Δn=0.4282

[1017] g1=61mPas

[1018] Synthesis Example 3: 5-[4-(4-Butylcyclohexyl)phenyl]-4-fluoro-2-isothiocyanatopyridine

[1019] Step 3.1: 5-[4-(4-Butylcyclohexyl)phenyl]-4-fluoro-pyridin-2-amine

[1020]

[1021] A mixture of [4-(4-butylcyclohexyl)phenyl]boronic acid (CAS 516510-90-0, 5.5 g, 21 mmol), 5-bromo-4-fluoro-pyridin-2-amine (2) (CAS 944401-69-8, 4.0 g, 20 mmol) and potassium carbonate (5.7 g, 41 mmol) in distilled water (20 ml) and 1,4-dioxane (80 ml) was treated with [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II)-dichloromethane complex (0.9 g, 1 mmol) under argon atmosphere at room temperature. The reaction mixture was stirred at 90°C overnight. It was then cooled to room temperature and filtered through Celite. The filtrate was diluted with MTB ether and distilled water. The aqueous phase was separated and extracted with MTB ether. The combined organic phases were washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue was purified by silica gel chromatography (MTB ether) to give 5-[4-(4-butylcyclohexyl)phenyl]-4-fluoro-pyridin-2-amine as yellow crystals.

[1022] Step 3.2: 5-[4-(4-Butylcyclohexyl)phenyl]-4-fluoro-2-isothiocyanatopyridine

[1023]

[1024] At 0 ℃ under argon atmosphere, thiophosgene (1.8ml, 23mmol) is slowly added to 5-[4-(4-butylcyclohexyl) phenyl]-4-fluoro-pyridine-2-amine (6.1g, 19mmol) and DABCO (5.3g, 47mmol) in dichloromethane (120ml) solution, and the reaction mixture is stirred at room temperature overnight. It is then quenched with distilled water and saline. The aqueous phase is separated and extracted with dichloromethane. The combined organic phase is washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue is purified through silica gel chromatography (1-chlorobutane) and crystallization (heptane) to obtain 5-[4-(4-butylcyclohexyl) phenyl]-4-fluoro-2-isothiocyanate pyridine yellow crystals.

[1025] Phase sequence:

[1026] K 60 N 169 I.

[1027] Δε=7.3

[1028] Δn=0.2549

[1029] Synthesis Example 4: 5-[4-(4-Butylcyclohexyl)phenyl]-4-chloro-2-isothiocyanatopyridine

[1030] Step 4.1: 5-[4-(4-Butylcyclohexyl)phenyl]-4-chloro-pyridin-2-amine

[1031]

[1032] At room temperature under argon atmosphere, a mixture of [4-(4-butylcyclohexyl)phenyl]boronic acid (CAS 516510-90-0, 4.2 g, 16.1 mmol), 5-bromo-4-chloro-pyridin-2-amine (CAS 942947-94-6, 3.5 g, 16 mmol) and potassium carbonate (4.5 g, 33 mmol) in 1,4-dioxane (60 ml) and distilled water (15 ml) was treated with [1,1'-bis(diphenylphosphino)ferrocene]-dichloropalladium(II)-dichloromethane complex (680 mg, 0.8 mmol), and the reaction mixture was stirred at reflux temperature overnight. It was then cooled to room temperature, diluted with MTB ether and distilled water, and filtered through Celite. The aqueous phase was separated and extracted with MTB ether. The combined organic phases were washed with distilled water and brine, dried (sodium sulfate), and concentrated in vacuo. The residue was purified by silica gel chromatography (MTB ether) to give 5-[4-(4-butylcyclohexyl)phenyl]-4-chloro-pyridin-2-amine (3) as a grey solid.

[1033] Step 4.2: 5-[4-(4-Butylcyclohexyl)phenyl]-4-chloro-2-isothiocyanatopyridine

[1034]

[1035] A solution of 5-[4-(4-butylcyclohexyl)phenyl]-4-chloro-pyridin-2-amine (5.2 g, 15 mmol) and DABCO (4.3 g, 38 mmol) in dichloromethane (150 ml) was cooled to 0°C and treated with thiophosgene (1.5 ml, 19 mmol). The suspension was stirred at room temperature overnight. It was then hydrolyzed with distilled water, filtered through silica gel and concentrated in vacuo. The residue was purified by silica gel chromatography (1-chlorobutane) and crystallization (heptane). 5-[4-(4-butylcyclohexyl)phenyl]-4-chloro-2-isothiocyanatopyridine was isolated as a yellow solid.

[1036] Phase sequence:

[1037] K 70N 89I.

[1038] Δε=6.31

[1039] Δn=0.2082

[1040] Synthesis Example 5: 5-[4-(4-Butylcyclohexyl)phenyl]-3-chloro-2-isothiocyanatopyrazine

[1041] Step 5.1: 5-[4-(4-Butylcyclohexyl)phenyl]-3-chloro-pyrazin-2-amine

[1042]

[1043] At room temperature under argon atmosphere, a mixture of [4-(4-butylcyclohexyl)phenyl]boronic acid (CAS 516510-90-0, 4.4 g, 17 mmol), 5-bromo-3-chloro-pyrazin-2-amine (CAS 38185-55-6, 3.5 g, 17 mmol) and potassium carbonate (4.7 g, 34 mmol) in 1,4-dioxane (60 ml) and distilled water (15 ml) was treated with [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II)-dichloromethane complex (700 mg, 0.8 mmol), and the reaction mixture was stirred at reflux temperature overnight. It was then cooled to room temperature, diluted with MTB ether and distilled water, and filtered through Celite. The aqueous phase was separated and extracted with MTB ether. The combined organic phases were washed with distilled water and brine, dried (sodium sulfate), and concentrated in vacuo. The residue was purified by silica gel chromatography (dichloromethane) to give 5-[4-(4-butylcyclohexyl)phenyl]-3-chloro-pyrazin-2-amine as an orange solid.

[1044] Step 5.2: 5-[4-(4-Butylcyclohexyl)phenyl]-3-chloro-2-isothiocyanatopyrazine

[1045]

[1046] A solution of 5-[4-(4-butylcyclohexyl)phenyl]-3-chloro-pyrazin-2-amine (5.4 g, 15 mmol) and DABCO (4.2 g, 37 mmol) in dichloromethane (100 ml) was cooled to 0°C and treated with thiophosgene (1.5 ml, 19 mmol). The suspension was stirred at room temperature overnight. It was then hydrolyzed with distilled water, filtered through silica gel, and concentrated in vacuo. The residue was purified by silica gel chromatography (1-chlorobutane) and crystallization (n-heptane). 5-[4-(4-butylcyclohexyl)phenyl]-3-chloro-2-isothiocyanatopyrazine was isolated as a yellow solid.

[1047] Phase sequence:

[1048] Tg-35K 46N 61I.

[1049] Δε=6.9

[1050] Δn=0.2592

[1051] The following compounds were obtained analogously to Synthesis Examples 1 to 5:

[1052]

[1053]

[1054]

[1055]

[1056]

[1057]

[1058]

[1059]

[1060]

[1061]

[1062] Mixture Examples

[1063] Liquid crystal mixtures H1, H2 and M1 to M11 having the compositions and properties shown in the table below were prepared and characterized with respect to their general physical properties and their suitability for use in microwave components at 19 GHz and 20°C.

[1064] Main mixture H1

[1065]

[1066]

[1067] Main medium H2

[1068]

[1069] Host mixture H3

[1070]

[1071]

[1072] Mixture Example M1

[1073]

[1074] The addition of the compound CPPz-4-S according to the invention to the medium H1 leads to an improvement in the quality factor h from 29.3 to 31.6, which is due to the dielectric loss tan δε r,⊥ Significantly lower.

[1075] Mixture Example M2

[1076]

[1077]

[1078] Mixture Example M3

[1079]

[1080] Mixture Example M4

[1081]

[1082] Mixture Example M5

[1083]

[1084] Mixture Example M6

[1085]

[1086]

[1087] Mixture Example M7

[1088]

[1089] Mixture Example M8

[1090]

[1091] Mixture Example M9

[1092]

[1093] Mixture Example M10

[1094]

[1095]

[1096] Mixture Example M11

[1097]

[1098] Mixture Example M12

[1099]

[1100] Mixture Example M13

[1101]

[1102]

[1103] Mixture Example M14

[1104]

[1105] Mixture Example M15

[1106]

[1107]

[1108] Mixture Example M16

[1109]

[1110] Mixture Example M17

[1111]

[1112]

[1113] Mixture Example M18

[1114]

[1115] Mixture Example M19

[1116]

[1117] Mixture Example M20

[1118]

[1119] Mixture Example M21

[1120]

[1121] Mixture Example M22

[1122]

[1123] Mixture Example M23

[1124]

[1125] Mixture Example M24

[1126]

[1127]

[1128] Mixture Example M25

[1129]

[1130] Mixture Example M26

[1131]

Claims

1. A compound of formula N, selected from the group consisting of formula N-1, N-2 and N-3: in R N represents H, an alkyl or alkoxy radical having 1 to 12 C atoms, or an alkenyl, alkenyloxy or alkoxyalkyl radical having 2 to 12 C atoms, wherein one or more CH2- radicals may be Replacement; Express the same or different meanings each time it appears in R L represents, identically or differently on each occurrence, H or an alkyl radical having 1 to 6 C atoms, L represents F or an alkyl group having 1-6 C atoms, and r is 0, 1, 2, 3, 4, 5, or 6, in Alternatively expressed where R H Indicates H; Z N1 and Z N2 Identically or differently represent -C≡C- or a single bond; X 1 and X 2 identically or differently represent H, Cl, F, methyl or ethyl; and n is 0, 1 or 2.

2. The compound according to claim 1, wherein X 1 and X 2 Indicates H.

3. The compound according to claim 1, wherein X 1 Indicates H and X 2 Indicates F or Cl.

4. The compound according to claim 1, wherein X 1 Indicates F or Cl and X 2 Indicates H.

5. The compound according to claim 1, wherein X 1 and X 2 Indicates F.

6. A liquid-crystalline medium comprising one or more compounds according to any one of claims 1 to 5.

7. A liquid-crystalline medium according to claim 6, wherein the medium comprises a compound of the formula NI in R N 、 Z N1 , Z N2 , W, X 1 、X 2 and n have the corresponding meanings given for formula N in claim 1 .

8. Liquid-crystalline medium according to claim 6 or 7, wherein the medium comprises one or more compounds selected from the group consisting of compounds of the formulae I, II and III, in R 1 represents H, a non-fluorinated alkyl or non-fluorinated alkoxy radical having 1-17 C atoms, or a non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl radical having 2-15 C atoms, wherein one or more CH2- groups may be Alternative, n is 0, 1, or 2, to Each occurrence represents independently of each other where R L Each occurrence represents H in the same or different way or with 1-6 C atoms in the alkyl group, and among them Alternatively expressed R 2 represents H, a non-fluorinated alkyl or non-fluorinated alkoxy radical having 1-17 C atoms, or a non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl radical having 2-15 C atoms, wherein one or more CH2- groups may be Alternative, Z 21 represents trans-CH=CH-, trans-CF=CF- or -C≡C-, and Independently express where R L Each occurrence is the same or different, indicating H or having Alkyl groups with 1 to 6 carbon atoms; R 3 represents H, a non-fluorinated alkyl or non-fluorinated alkoxy radical having 1-17 C atoms, or a non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl radical having 2-15 C atoms, wherein one or more CH2- groups may be Alternative, Z 31 and Z 32 one represents trans-CH=CH-, trans-CF=CF- or -C≡C- and the other independently represents -C≡C-, trans-CH=CH-, trans-CF=CF- or a single bond, and to Independently express where R L Each occurrence is the same or different, indicating H or having Alkyl groups with 1 to 6 C atoms, and among them Alternatively expressed 9. Liquid-crystalline medium according to claim 6 or 7, wherein the medium comprises one or more compounds selected from the group consisting of compounds of the formulae I-1 to I-5 in L 1 、L 2 and L 3 Each occurrence represents H or F, either identically or differently, and R 1 、 has the meaning given for formula I in claim 8.

10. Liquid-crystalline medium according to claim 6 or 7, wherein the medium comprises one or more compounds selected from the group consisting of compounds of the formulae II-1 to II-3 in R 2 、 has the meaning given in claim 8 for formula II.

11. Liquid-crystalline medium according to claim 6 or 7, wherein the medium comprises one or more compounds selected from the group consisting of compounds of the formulae III-1 to III-6 in R 3 、 has the meaning given in claim 8 for formula III, and Z 31 and Z 32 represent, independently of each other, trans-CH=CH- or trans-CF=CF-, and in formula III-6, Z 31 and Z 32 One alternatively represents -C≡C-.

12. A liquid-crystalline medium according to claim 6 or 7, wherein the medium comprises one or more compounds of 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, Each occurrence represents independently of each other L 4 and L 5 represent, identically or differently, F, Cl or a linear, branched or cyclic alkyl or alkenyl group each having up to 12 C atoms; Z T3 , Z T4 represents, identically or differently, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, and t is 0 or 1.

13. A component for high-frequency technology, characterized in that it comprises a liquid-crystalline medium according to any of claims 6 to 12.

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

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

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