Liquid-crystalline medium

Abstract

The present invention relates to liquid-crystalline (LC) media or LC materials and to energy saving liquid-crystal displays (LCDs) containing these media, especially to gaming displays and AR / VR headsets addressed by an active matrix and in particular to LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, SA-HB-FFS, SA-XB-FFS, polymer stabilised SA-HB- FFS, polymer stabilised SA-XB-FFS, positive VA or positive PS-VA type.

Description

[0001] Foreignfiling text P24-166-SEC-WO01

[0002] 1

[0003] Liquid-crystalline medium

[0004] The present invention relates to liquid-crystalline (LC) media and to energy saving liquid-crystal displays (LCDs) containing these media, especially to automotive and

[0005] 5 gaming displays and AR / VR headsets. In particular, it relates to LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, SA- HB-FFS, SA-XB-FFS, polymer stabilised SA-HB-FFS, polymer stabilised SA-XB- FFS, positive VA or positive PS-VA type. In a preferred embodiment, the LC media have positive dielectric anisotropy.

[0006] LCDs are used in many areas for the display of information. LCDs are used both for direct-view displays and for projection-type displays. The electro-optical modes used are, for example, the twisted nematic (TN), super twisted nematic (STN), optically compensated bend (OCB) and electrically controlled birefringence (ECB) modes

[0007] 15 together with their various modifications, as well as others. All these modes utilise an electric field which generated substantially perpendicular to the substrates and the LC layer.

[0008] Besides these modes, there are also electro-optical modes that utilise an electric

[0009] 20 field which is substantially parallel to the substrates or the LC layer. For example, WO 91 / 10936 discloses a LC display in which the electric signals are generated in such a way that the electric fields have a significant component parallel to the LC layer, and which has since then become known as “in- lane switching" (IPS) display. The principles of operating such a display are described, for example, by

[0010] 25 R.A. Soref in Journal of Applied Physics, Vol. 45, No. 12, pp. 5466-5468 (1974).

[0011] IPS displays contain an LC layer between two substrates with planar orientation, where the two electrodes are arranged on only one of the two substrates and preferably have interdigitated, comb-shaped structures. On application of a voltage to the electrodes an electric field with a significant component parallel to the LC layer is generated between them. This causes realignment of the LC molecules in the layer plane.

[0012] EP 0 588 568, for example, discloses various possibilities for the design of the

[0013] 35 electrodes and for addressing an IPS display. DE 198 24 137 likewise describes Foreignfiling text P24-166-SEC-WO01

[0014] 2 various embodiments of such IPS displays.

[0015] LC materials for IPS displays of this type are described, for example, in DE 195 28 104.

[0016] 5

[0017] Furthermore, so-called “fringe-field switching" (FFS) displays have been reported (see, inter alia S.H. Jung et al., Jpn. J. Appl. Phys., Volume 43, No. 3, 2004, 1028), which contain two electrodes on the same substrate, one of which is structured in a comb-shaped manner and the other is unstructured. A strong, so-called "fringe field" is thereby generated, i.e. a strong electric field close to the edge of the electrodes, and, throughout the cell, an electric field which has both a strong vertical component and also a strong horizontal component. FFS displays have a low viewing-angle dependence of the contrast. FFS displays usually contain an LC medium with positive dielectric anisotropy, and an alignment layer, usually of polyimide, which

[0018] 15 provides planar alignment to the molecules of the LC medium.

[0019] LCDs of the IPS and FFS electro-optical mode are, in particular, suitable for use in modern desktop monitors, TV sets and multimedia applications. The LC media according to the present invention are preferably used in displays of this type. In

[0020] 20 general, dielectrically positive LC media having rather lower values of the dielectric anisotropy are used in FFS displays, but in some cases LC media having a dielectric anisotropy of only about 3 or even less are also used in IPS displays.

[0021] A further improvement has been achieved by the HB-FFS mode. One of the unique

[0022] 25 features of the HB-FFS mode in contrast to the traditional FFS technology is that it enables higher transmittance which allows operation of the panel with less energy consumption.

[0023] Another recently developed mode is the XB-FFS mode, wherein the LC medium additionally contains a polar liquid crystal compound with low dielectric anisotropy.

[0024] FFS and IPS displays can be operated as active-matrix displays (AMD) or passivematrix displays (PMD). In the case of active-matrix displays individual pixels are usually addressed by integrated, non-linear active elements such as, for example,

[0025] 35 thin-film transistors (TFTs), while in the case of passive-matrix displays individual Foreignfiling text P24-166-SEC-WO01

[0026] 3 pixels are usually addressed by the multiplex method as known from the prior art. The displays according to the present invention are preferably addressed by an active matrix, preferably by a matrix of TFT. However, the LC media according to the invention can also advantageously be used in displays having other known

[0027] 5 addressing means.

[0028] Typical applications of IPS and FFS technologies are monitors, notebooks, televisions, mobile telephones, tablet PCs, etc. Both the IPS and the FFS technology have certain advantages over other LCD technologies, such as, for example, the vertical alignment (VA) technology, e.g. a broad viewing angle dependency of the contrast.

[0029] The provision of further LC media and the use thereof in a display having high transmission, a good black state and a high contrast ratio is a central challenge for

[0030] 15 modern FFS and IPS applications. In addition, modern applications also require good low-temperature stability and fast addressing times.

[0031] Until now, it was not possible to design suitable LC media for automotive and gaming having a high contrast ratio e.g. high elastic constants and Kav, low

[0032] 20 temperature stability and low response time parameter y-| / Ki . Therefore, the overall picture quality in such devices still requires a further improvement. In particular, in the area of gaming applications, for the purpose of achieving fast switching speed other parameters, which are relevant for the image quality, have been often sacrificed.

[0033] 25

[0034] The present invention has the object of providing LC media, in particular for energy saving gaming FFS and IPS displays, automotive applications and AR / VR headsets, but also for TN, positive VA or STN displays, and in particular for active-matrix displays like those addressed by TFTs, which have a high average elastic constant Kavin combination with a low response time parameter and a low rotational viscosity and a relatively low birefringence An. Additionally, they need to have a high specific resistance, low threshold voltage, high dielectric anisotropy, a good low temperature stability (LTS), fast response times, and enable high brightness. In case Foreignfiling text P24-166-SEC-WO01

[0035] 4 brightness and reliability. However, it was found that the LC materials of the prior art do often not achieve all these requirements at the same time.

[0036] Surprisingly, the above technical problem has been solved by providing LC media

[0037] 5 as described and claimed hereinafter.

[0038] Prior art, for example WO 2011 I 076329 A1 and DE 102015 015 108 A1, discloses LC media comprising compounds with 5,6-dihydro-4 / 7-cyclopenta[b]thiophene as a core unit. WO 2011 / 076329 A1 teaches compounds containing a 5,6-dihydro-4 / 7- cyclopenta[b]thiophene unit which is linked directly to a 2- and / or 6-substituted 1,4- phenylene unit:

[0039] DE 102015 015 108 A1 describes compounds of the following general formula:

[0040] 20 as well as nematic LC media comprising the same.

[0041] 25

[0042] However, the LC media of the prior art still require an even further improvement in terms of a sufficiently high average elastic constant Kavin combination with a low response time parameter yi / K-| .

[0043] It has now been surprisingly found that LC media according to the present invention which contain one or more compounds of the Formula S Foreignfiling text P24-166-SEC-WO01

[0044] 5

[0045] 5 in which the individual substituents are specified in Claim 1, show several remarkable improvements, especially when being used in FFS mode displays, like a high average elastic constant Kav, a low response time parameter (Y1 / Ki) in combination with a low rotational viscosity as well as a good solubility, and enable fast response times.

[0046] Additionally, the LC media according to the present invention have high clearing

[0047] 15 points, an excellent low temperature stability (LTS) and provide a superior motion picture quality and an improved overall image quality, in particular a high contrast.

[0048] The present invention relates to a LC medium, characterised in that it comprises one or more compounds of Formula S:

[0049] 20 in which the individual substituents, on each occurrence identically or differently, and each, independently of one another, have the following meanings: Foreignfiling text P24-166-SEC-WO01

[0050] 5

[0051] R1 and R2 each, independently of one another, denote a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 to 12 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, -CH=CH-,

[0052] , -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by

[0053] 15 a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom; i to each, independently of one another, denote H, F or Cl;

[0054] 20 to yS each, independently of one another, denote a H atom, an alkyl group having 1 to 3 C atoms or an alkenyl group having 2 to 3 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or

[0055] 25 -O-CO- in such a way that O atoms are not linked directly to one another, preferably H or CH3;

[0056] Z1denotes -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2H4-,

[0057] -C2F4-, -CF2CH2-, -CH2CF2-, -CFHCFH-, -CFHCH2-, -CH2CFH-, -CF2CFH-, -CFHCF2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C=C- or a single bond; k denotes 0, 1, 2 or 3. Foreignfiling text P24-166-SEC-WO01

[0058] 7

[0059] A further aspect of the present invention relates to the compound of Formula S as defined above.

[0060] Yet a further aspect of the present invention relates to a process for preparation of

[0061] 5 the compound of Formula S.

[0062] The LC media according to the present invention are especially suitable for use in energy saving LC displays of the FFS, HB-FFS, XB-FFS and IPS mode for gaming based on dielectrically positive LC media, and polymer stabilised variants thereof.

[0063] The present invention further relates to the use of a LC medium as described above and below for electro-optical purposes, in particular for the use in LC displays, shutter glasses, LC windows, 3D applications, preferably in TN, PS-TN, STN, TN- TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-HB-FFS, PS-XB-FFS, SA-HB-

[0064] 15 FFS, SA-XB-FFS, polymer stabilised SA-HB-FFS, polymer stabilised SA-XB-FFS, positive VA and positive PS-VA displays, very preferably in FFS, HB-FFS, IPS, PS- HB-FFS and PS-IPS displays.

[0065] The invention further relates to an electro-optical LC display containing a LC

[0066] 20 medium as described above and below, in particular a TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-HB-FFS, PS-XB-FFS, SA-HB-FFS, SA-XB-FFS, polymer stabilised SA-HB-FFS, polymer stabilised SA-XB-FFS, positive VA or positive PS-VA display, preferably a FFS, HB-FFS, IPS, PS-HB-FFS or PS- IPS display.

[0067] 25

[0068] In the present application, all atoms may optionally include their isotopes. In some embodiments, one or more hydrogen atoms (H) may be optionally replaced by deuterium (D).

[0069] In the Formulae S, P and B, or YA, YB, YC, YD, YE and YF if R1, R2, R21, R22and R23 denote an alkyl group and / or an alkoxy group, this may be straight-chain or branched. It is preferably straight-chain, has 2, 3, 4, 5, or 6 C atoms and preferably denotes ethyl, propyl, butyl, pentyl, hexyl, ethoxy, propoxy, butoxy, pentoxy, or hexyloxy, furthermore methyl, methoxy. R1, R2, R2^, R22and R2^ preferably

[0070] 35 Foreignfiling text P24-166-SEC-WO01

[0071] 8 denote straight-chain alkyl having 1 to 6 C atoms or an alkenyl group having 2 to 6 C atoms.

[0072] Oxaalkyl preferably denotes straight-chain 2-oxapropyl (= methoxymethyl),

[0073] 5 2- (= ethoxymethyl) or 3-oxabutyl (= 2-methoxyethyl), 2-, 3- or 4-oxapentyl, 2-, 3-,

[0074] 4- or 5-oxahexyl.

[0075] If R1, R2, R21 , R22ANC| R23 denotes an alkoxy or oxaalkyl group it may also contain one or more additional oxygen atoms, provided that oxygen atoms are not linked directly to one another.

[0076] In another preferred embodiment, one or more of R1, R2, R21 , R22ANC| R23ARE

[0077] 15

[0078] 20 Ci-i2-alkylene or C2-i2-alkenylene and s2 is H, Ci .12-alkyl or C2-i2-alkenyl, and very preferably one or more of R\ R2, R21 , R22ANC| R23areselected from the

[0079] -O(CH2)4F.

[0080] If R1, R2, R21 , R22and R23 denotes an alkenyl group, this may be straight-chain or branched. It is preferably straight-chain and has 2 to 10 C atoms. Accordingly, it

[0081] 35 denotes, in particular, vinyl, prop-1- or -2-enyl, but-1-, -2- or -3-enyl, pent-1-, -2-, Foreignfiling text P24-166-SEC-WO01

[0082] -3- or -4-enyl, hex-1-, -2-, -3-, -4- or -5-enyl, hept-1-, -2-, -3-, -4-, -5- or -6-enyl, oct-1-, -2-, -3-, -4-, -5-, -6- or -7-enyl, non-1-, -2-, -3-, -4-, -5-, -6-, -7- or -8-enyl, dec- 1- , -2- , -3- , -4- , -5- , -6- , -7- , -8- or -9-enyl.

[0083] 5

[0084] If R1, R2, R21 , R22ANC| R23 denotes an alkyl or alkenyl group which is at least monosubstituted by halogen, this group is preferably straight-chain, and halogen is preferably F or Cl. In the case of polysubstitution, halogen is preferably F. The resultant groups also include perfluorinated groups. In the case of monosubstitution, the fluorine or chlorine substituent may be in any desired position, but is preferably in the ra-position.

[0085] Particularly preferred groups R R2, R21 , R22anR23 denotes alkyl, alkenyl, alkynyl or alkoxy having up to 12, preferably up to 8 C atoms, each of which is optionally substituted by halogen, in particular by F, particularly preferred are H, F,

[0086] 15 alkyl, alkenyl or alkynyl having up to 8 C atoms.

[0087] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl and n-octyl. Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl and pentenyl. Preferred alkynyl groups are, for example, ethynyl,

[0088] 20 propynyl, butynyl, pentynyl, hexynyl, heptynyl and octynyl. Preferred alkoxy groups are, for example, methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy. Halogen preferably denotes F or Cl, F being mostly preferred.

[0089] Compounds of Formula S

[0090] 25

[0091] Preference is given to LC media comprising the compounds of Formula S in which Foreignfiling text P24-166-SEC-WO01

[0092] 10 is particularly preferred.

[0093] I_3 and l_4 may each, independently of one another, denote H, F or Cl, preferably H or F, H being particularly preferred.

[0094] Preference is furthermore given to compounds of the Formula S in which k denotes

[0095] 15 0, 1 or 2, particularly preferably 0 or 1. Preference is furthermore given to compounds of the Formula S in which k denotes 0, 1 or 2, preferably 1 or 2 and very particularly preferably 1.

[0096] 7^ in Formula S particularly preferably denote -CF2O-, -OCF2- or a single bond,

[0097] 20 wherein a single bond is particularly preferred.

[0098] Preference is furthermore given to compounds of the Formula S in which R1 and R2 each, independently of one another, denote H, alkyl, alkenyl or alkynyl having up to 8, preferably up to 5 C atoms, each of which is optionally substituted by halogen, in

[0099] 25 particular by F.

[0100] Particularly preferred groups R1 and R2 in Formula S denote H, alkyl, alkenyl, alkynyl or alkoxy having up to 12, preferably up to 8 C atoms, each of which is optionally substituted by halogen, in particular by F, particularly preferred are alkyl, alkenyl or alkynyl having up to 8 C atoms. Preferably, at least one group is not H, particularly preferably both groups R^ and R^ are not H. R^ is very particularly preferably equal to alkyl. R2 is furthermore preferably H, alkyl, alkyl which is substituted by at least one fluorine. Very particularly preferably, R^ is alkyl and R^ is

[0101] 35 H or alkyl. R1, R2 each, independently of one another, very particularly preferably Foreignfiling text P24-166-SEC-WO01

[0102] 11 denote unbranched alkyl having 1 to 5 C atoms. If R1 and R2 denote substituted alkyl, alkoxy, alkenyl or alkynyl, the total number of C atoms in the two groups R^ and R2 is preferably less than 10.

[0103] 5

[0104] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl and n-octyl.

[0105] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl and pentenyl.

[0106] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl and octynyl.

[0107] Preferred alkoxy groups are, for example, methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy.

[0108] 15

[0109] Halogen preferably denotes F or Cl, F being mostly preferred.

[0110] The preferred compounds of the Formula S result in LC media having a particularly high clearing point, low rotational viscosity, a broad nematic phase range, high

[0111] 20 birefringence and an excellent thermal and UV stability.

[0112] Particularly preferred compounds of the Formula S are those selected from the following sub-formulae:

[0113] 25

[0114] 35 Foreignfiling text P24-166-SEC-WO01

[0115] 12

[0116] 25 in which in which Y^, Y^, Y^, Z^, R1 and R2 and U to l_4 have the meanings indicated in general Formula S.

[0117] In a more preferred embodiment

[0118] R1 and R2 denotes an alkyl or an alkoxy group having 1 to 6 C atoms or an alkenyloxy or an alkenyl group having 2 to 6 C atoms in which one or more CH2 groups are optionally substituted by -C=C-, -CF2O-, Foreignfiling text P24-166-SEC-WO01

[0119] 13 such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be substituted by a halogen atom, preferably alkyl, alkenyl or

[0120] 5 alkynyl having up to 5 C atoms; to yS each, independently from one another, denote a H atom or a methyl group, preferably a H atom; denotes a single bond, -C=C-, -CF2O-, -OCF2-, -CH2O-, -OCH2-,

[0121] -COO-, or -OCO-, preferably a single bond;

[0122] U to l_4 each, independently from one another, denote a H atom, F or Cl.

[0123] 15

[0124] LC media according to the present invention having a particularly advantageous properties are obtainable with the following compounds of the general Formula S: Foreignfiling text P24-166-SEC-WO01

[0125] 14

[0126] 35 Foreignfiling text P24-166-SEC-WO01

[0127] 15 wherein Y Y^, R1 and R^ are as defined above.

[0128] 20

[0129] In one preferred embodiment of the present invention, the LC medium comprises one or more compound of Formula S-5-2 and / or one or more compound of Formula S-5-3.

[0130] 25 In yet a further preferred embodiment, LC media comprise the following compounds of Formula S:

[0131] 35 Foreignfiling text P24-166-SEC-WO01

[0132] 16

[0133] 35 Foreignfiling text P24-166-SEC-WO01

[0134] 5 wherein n and m each, independently of one another, denote 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

[0135] Mostly preferred compounds of Formula S include, in particular, one or more of the following:

[0136] 15 Foreignfiling text P24-166-SEC-WO01

[0137] 18

[0138] 20

[0139] 35 Foreignfiling text P24-166-SEC-WO01 5 As a further possibility, the following compounds of Formula S can be used: Foreignfiling_text P24-166-SEC-WO01

[0140] 20

[0141] 10 Foreignfilingjext P24-166-SEC-WO01

[0142] 21 Foreignfiling text P24-166-SEC-WO01

[0143] As a further possibility, the following compounds of Formula S can be used: 5 Foreignfiling text P24-166-SEC-WO01

[0144] 23 5 Foreignfiling text P24-166-SEC-WO01

[0145] 1 5 Foreignfiling text P24-166-SEC-WO01

[0146] Very preferred are the compounds of formulae S-5-3-6 and S- 5-2-4.

[0147] The proportion of the compounds of Formula S or its subformulae in the LC medium is preferably from 0.5 to 40%, very preferably from 1 to 30%, most preferably from 1.5 to 20% by weight.

[0148] 15 Preparation of the compound of Formula S

[0149] The compounds of the general Formula S are prepared by methods known perse, as described in the literature (e.g. in the standard works, such as Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Georg-Thieme-

[0150] 20 Verlag, Stuttgart) under reaction conditions which are known and are suitable for said reactions. Use can be made of variants which are known perse, but are not mentioned here in greater detail.

[0151] If desired, the starting materials can also be formed in situ by not isolating them from

[0152] 25 the reaction mixture, but instead by immediately reacting them further into the compounds of Formula S.

[0153] The compounds of the Formula S may be prepared in analogy to the processes described in DE 102010 052810 A1. A preferred synthetic pathway towards compounds according to the invention is exemplified in Scheme 1 below in which the occurring groups and parameters have the meanings given for Formula S. X is a leaving group such as Cl, Br, I, OMs, OTs or OTf. The group M indicates a residue containing an atom selected from boron, zinc, tin, silicon, lithium and magnesium. The compound of Formula S can be readily prepared using a transition metal

[0154] 35 catalyzed cross coupling reaction from the building blocks 1 and 2. In one preferred Foreignfiling text P24-166-SEC-WO01 embodiment, the group M comprises a boron atom and the cross coupling reaction between the building blocks 1 and 2 is Suzuki cross coupling.

[0155] 25

[0156] Scheme 1

[0157] The preparation of the compound of Formula S is further illustrated by means of the working examples and can be adapted to the particular desired compounds of the general Formula S by choice of suitable starting materials.

[0158] In some preferred embodiments, the LC medium may additionally comprise one or more compounds selected from the following Formulae II and III:

[0159] 35 Foreignfiling text P24-166-SEC-WO01

[0160] 27 wherein the individual substituents, independently of each other and on each occurrence identically or differently, have the following meanings:

[0161] 15

[0162] 35 Foreignfiling text P24-166-SEC-WO01

[0163] RO has one of the meanings given for R1 and R2 in Formula S,

[0164] XO independently of one another denotes a halogen atom, -CN, -SCN, or an alkyl or alkoxy group having 1 to 6 C atoms or an alkenyl or alkenyloxy group having 2 to 6 C atoms in which one or more H

[0165] 5 atoms has been substituted by a halogen atom, l ’8 independently of one another H, F or Cl, and yO has one of the meanings given for in Formula S.

[0166] Preferred compounds of the Formula II and III are those wherein is H.

[0167] Further preferred compounds of the Formula II and III are those wherein R^ denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably

[0168] 15 ethyl, propyl, butyl, pentyl,

[0169] 20

[0170] XO preferably denotes F, CF3 , CHF2 , OCHF2 or OCFs, furthermore OCF=CF2, OCHFCF3 or Cl, very preferably F.

[0171] 25

[0172] In a preferred embodiment, the LC medium comprises one or more compounds of the Formula II selected from the following subformulae:

[0173] 35 Foreignfiling_text P24-166-SEC-WO01 Foreignfiling text P24-166-SEC-WO01

[0174] 30 in which have the meanings given in the Formula II.

[0175] Preferred compounds are those of the Formula 11-1 , II-2 and II-3, very preferred those of the Formula 11-1 and II-2.

[0176] In the compounds of the Formulae 11-1 to II-9 R^ preferably denotes alkyl having 1 to

[0177] 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl,

[0178] 15

[0179] 20

[0180] X0 preferably denotes F, CF3 , CHF2 , OCHF2 or OCFs, furthermore OCF=CF2, OCHFCF3 or Cl, very preferably F.

[0181] 25 As examples of particularly preferred compounds of Formula II the following compounds can be mentioned: Foreignfiling text P24-166-SEC-WO01

[0182] 31

[0183] "alkyF being an alkyl group with 1 to 6 C atoms, being preferably selected from ethyl, propyl, butyl, pentyl, wherein propyl is particularly preferred.

[0184] 5

[0185] In one embodiment, the LC medium contains one or more compounds of the Formula II or their subformulae as described above and below, wherein is CH3 . Very preferably, the LC medium according to this preferred embodiment comprises one or more compounds of the Formula II selected from the following subformulae:

[0186] 2 0

[0187] 35 Foreignfiling text P24-166-SEC-WO01 in which have the meanings given in the Formula II.

[0188] Preferred compounds are those of the Formula IIA-1 , IIA-2 and IIA-3, very preferred

[0189] 25 are those of Formula IIA-1 and IIA-2.

[0190] In the compounds of the Formulae IIA-1 to IIA-9 R^ preferably denotes alkyl having

[0191] 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl,

[0192] 35 Foreignfiling text P24-166-SEC-WO01

[0193] 33

[0194] XO preferably denotes F, CF3 , CHF2 , OCHF2 or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl, very preferably F.

[0195] The proportion of the compounds of the Formula II in the LC medium is typically

[0196] 5 from 0 to 30%, very preferably from 1 to 20%, most preferably from 2 to 15% by weight.

[0197] In a further preferred embodiment, the LC medium comprises one or more compounds of the Formula III selected from the following subformulae:

[0198] 15

[0199] 20

[0200] 35 Foreignfiling text P24-166-SEC-WO01

[0201] 5

[0202] 25

[0203] 35 Foreignfiling text P24-166-SEC-WO01 0 5 Foreignfiling text P24-166-SEC-WO01

[0204] 36

[0205] 15 in which have the meanings given in the Formula II.

[0206] Particularly preferred compounds are those of the Formulae 111-1 , HI-4, HI-6, HI -16, HI-19, HI-20 and HI-22.

[0207] 20

[0208] As examples of particularly preferred compounds of Formula HI the following compounds can be mentioned: Foreignfiling text P24-166-SEC-WO01

[0209] 37

[0210] 20

[0211] "alkyF being an alkyl group with 1 to 6 C atoms, being preferably selected from ethyl, propyl, butyl, pentyl, wherein propyl is particularly preferred.

[0212] 25 In the compounds of the Formulae 111-1 to HI-22 R^ preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl,

[0213] X0 preferably denotes F, CF3 , CHF2 , OCHF2 or OCFs, furthermore OCF=CF2,

[0214] OCHFCF3 or Cl, very preferably F.

[0215] 35 Foreignfiling text P24-166-SEC-WO01

[0216] The LC medium may contain one or more compounds of the Formula III or their subformulae as described above and below wherein is CH3 . Very preferably, the LC medium according to this preferred embodiment comprises one or more

[0217] 5 compounds of the Formula III selected from the following subformulae: Foreignfiling text P24-166-SEC-WO01

[0218] 39

[0219] 35 Foreignfiling text P24-166-SEC-WO01

[0220] 40

[0221] 20

[0222] 35 Foreignfiling text P24-166-SEC-WO01

[0223] 41

[0224] 5 in which have the meanings given in the Formula III.

[0225] Preferred compounds are those of the Formula IIIA-1, IIIA-4, IIIA-6, IIIA-16, IIIA-19 and IIIA-20.

[0226] In the compounds of the Formulae IIIA-1 to IIIA-21 R^ preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl,

[0227] 15 propyl, butyl, pentyl,

[0228] 20

[0229] X0 preferably denotes F, CF3 , CHF2 , OCHF2 or OCF3, furthermore OCF=CF2,

[0230] OCHFCF3 or Cl, very preferably F.

[0231] The proportion of the compounds of the Formula III in the LC medium is preferably from 2 to 60%, very preferably from 5 to 50%, most preferably from 10 to 30% by

[0232] 25 weight.

[0233] In a further preferred embodiment, the LC medium may additionally comprise one or more compounds selected from the following formulae:

[0234] 35 Foreignfiling text P24-166-SEC-WO01

[0235] 42 in which

[0236] The compounds of the Formula IV are preferably selected from the following formulae:

[0237] 35 Foreignfiling_text P24-166-SEC-WO01

[0238] 43 in which R^ and X^ have the meanings indicated in the Formulae II and III.

[0239] RO preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. preferably denotes F, CF3 , CHF2, OCHF2or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl.

[0240] The compounds of the Formula IVa are preferably represented by the following subformulae:

[0241] The compounds of the Formula IVb are preferably represented by the following

[0242] 35 formulae: Foreignfiling text P24-166-SEC-WO01

[0243] 44

[0244] The compounds of the Formulae IVc are preferably represented by the following a in which RO has the meanings indicated in the Formula II and is preferably alkyl

[0245] 20 having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, n- propyl, n- butyl or n- pentyl.

[0246] The compound(s) of the Formula IVc, in particular of the Formula IVc-1 , is (are) preferably employed in the LC media according to the invention in amounts of from 1%

[0247] 25 to 20% by weight, particularly preferably from 2 to 15% by weight.

[0248] The compounds of the Formula V are preferably selected from the following subformulae:

[0249] 35 Foreignfiling_text P24-166-SEC-WO01

[0250] 45

[0251] 30 in which R° and X° have the meanings indicated in the Formula II.

[0252] RO preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. X° preferably denotes F, CF3 , 35 CHF2 , OCHF2 and OCF3, furthermore OCF=CF2 , OCHFCF3 and OCH=CF2- Foreignfiling text P24-166-SEC-WO01

[0253] The compounds of the Formula VI are preferably selected from the following subformulae:

[0254] 20

[0255] 25 in which have the meanings indicated in the Formula II.

[0256] RO preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, n-propyl, n-butyl or n-pentyl. preferably denotes F, furthermore OCF3, CF3, OCHF2, CHF2, CF=CF2, OCHF2, OCHFCF3and OCH=CF2;

[0257] 35 Foreignfiling text P24-166-SEC-WO01

[0258] 47

[0259] Preferred compounds of the Formulae Via to Vie are those selected from the following subformulae:

[0260] "alkyF being an alkyl group with 1 to 6 C atoms, being preferably selected from ethyl, propyl, butyl, pentyl, wherein propyl is particularly preferred.

[0261] 25

[0262] The compounds of the Formula VII are preferably selected from the following subformulae:

[0263] 35 Foreignfiling text P24-166-SEC-WO01

[0264] 48

[0265] 5 in which have the meanings indicated in the Formula II.

[0266] RO preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. preferably denotes F, furthermore OCF3, OCHF2, CF3, CHF2, OCHFCF3 and OCH=CF2.

[0267] In some embodiments, the LC medium additionally comprises one or more compounds selected from the following formulae:

[0268] 15

[0269] 20

[0270] 35 Foreignfiling text P24-166-SEC-WO01

[0271] 49 in which each, independently of one another, have one of the meanings indicated in the Formula II,

[0272] 15 '4 each, independently of one another, denote H or F, yO denotes H or CH3, preferably H,

[0273] X° is preferably F, Cl, CF3CHF2OCHF2or OCF3, OCF=CF2,

[0274] OCHFCF3 ,

[0275] 20 RO preferably denotes alkyl, alkoxy, oxaalkyl, cycloalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms.

[0276] Very preferably, the LC medium according to the invention comprises one or more compounds of the following Formula XXa: in which R^ denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl and X^ denotes F, CF3 CHF2OCHF2or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl, very preferably F. R^ preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl and very

[0277] 35 particularly preferably n-propyl. Foreignfiling text P24-166-SEC-WO01

[0278] 50

[0279] The compound(s) of the Formula XX, in particular of the Formula XXa, is (are) preferably employed in the LC media according to the invention in amounts of 0-15% by weight, particularly preferably 1-10% by weight.

[0280] 5

[0281] The compounds of the Formula XXI are preferably represented by the Formulae XXIa

[0282] 20 in which RO denotes an alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl; and

[0283] X° denotes F, CF3CHF2OCHF2or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl.

[0284] 25

[0285] In a particularly preferred embodiment, the compounds of Formula XXI are represented by the following structure:

[0286] 35 Foreignfiling text P24-166-SEC-WO01

[0287] 51 in which R^ denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl . R^ preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl and very particularly preferably n-propyl.

[0288] 5

[0289] The compound(s) of the Formula XXI, in particular of the Formula XXIa-1 , is (are) preferably employed in the LC media according to the invention in amounts of 0-15% by weight, particularly preferably 1-10% by weight.

[0290] Further preferably, the LC medium according to the invention comprises one or more compounds of the Formula XXIIIa: in which RO denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms. RO preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or

[0291] 20 n-pentyl and very particularly preferably n-propyl or cycloalkyl, in particular cylclopentyl.

[0292] Preferred specific compounds of Formula XXIIIa include, in particular

[0293] In addition, or as an alternative to the compounds of Formula XXII la-1 , the following

[0294] 35 compound XXIIIa-3 may be employed: Foreignfiling text P24-166-SEC-WO01

[0295] 5

[0296] The compound(s) of the Formula XXIII, in particular of the Formula XXI I la, is (are) preferably employed in the LC media according to the invention in amounts of 0.5-5% by weight, particularly preferably 0.5-2% by weight.

[0297] The LC medium may additionally comprise one or more compounds of the Formula

[0298] XXIV: in which RO, X^ and U'6 have the meanings indicated in the Formula III, s denotes

[0299] 20 0 or 1 , and

[0300] 25

[0301] In the Formula XXIV, X^ may also denote an alkyl group having 1 to 6 C atoms or an alkoxy group having 1 to 6 C atoms. The alkyl or alkoxy group is preferably straight-chain.

[0302] RO preferably denotes alkyl having 1 to 6 C atoms. X^ preferably denotes F.

[0303] The compounds of the Formula XXIV are preferably selected from the following subformulae:

[0304] 35 Foreignfiling text P24-166-SEC-WO01

[0305] 53 Foreignfiling text P24-166-SEC-WO01

[0306] 54 in which RO, and U have the meanings indicated in the Formula III. R^ preferably denotes alkyl having 1 to 6 C atoms. preferably denotes F, and U is preferably F;

[0307] 5

[0308] 25

[0309] RO is straight-chain alkyl or alkenyl having 2 to 6 C atoms;

[0310] The LC medium may further comprise one or more compounds of the following formulae:

[0311] 35 Foreignfiling text P24-166-SEC-WO01

[0312] 55

[0313] 5 in which R^ have the meanings indicated in the Formula II for R^ and X^, respectively. R1 preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl . X^ preferably denotes F, CF3 CHF2 OCHF2 or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl, very preferably F. In the Formula XXIV, X^ very particularly preferably denotes Cl.

[0314] The LC medium may further optionally comprise one or more compounds of the following formulae: in which

[0315] 35 Foreignfiling text P24-166-SEC-WO01

[0316] 56 and R1, have the meanings indicated in the Formula II for RO, X^ and , respectively. R^ preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl . X^ preferably denotes F, CF3 , CHF2 , OCHF2 or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl,

[0317] 5 very preferably F, and Y^ preferably denotes H. In some embodiments, the LC medium according to the invention preferably comprises one or more compounds of the Formula XXIX in which X^ preferably denotes F.

[0318] The compounds of the Formula XXVII are preferably selected from the subformulae XXVIla, wherein XXVIIa-1 , XXVIIa-2 and XXVIIa-3 are mostly preferred:

[0319] "alkyl" being an alkyl group with 1 to 6 C atoms.

[0320] 35 Foreignfiling text P24-166-SEC-WO01

[0321] 57

[0322] The compounds of the Formula XXVIII are preferably selected from the subformulae

[0323] XXVIlla, wherein XXVIIIa-1 and XXVIIIa-2 are mostly preferred:

[0324] "alkyl" being an alkyl group with 1 to 6 C atoms.

[0325] 20

[0326] The compound(s) of the Formulae XXVII - XXX is (are) preferably employed in the LC media according to the invention in amounts of 1-20% by weight, particularly preferably 1-15% by weight. Particularly preferred LC media comprise at least one compound of the Formula XXIX and / or the Formula XXX.

[0327] 25

[0328] Very preferably, the LC medium according to the invention comprises one or more compounds of the Formulae XXIXa and / or XXXa:

[0329] 35 Foreignfiling text P24-166-SEC-WO01

[0330] 58

[0331] 5 in which R1 have the meanings indicated for R^ and in the Formula II, and preferably R^ denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl.

[0332] Preferred specific compounds of Formula XXIXa and XXXa include, in particular

[0333] The compound(s) of the Formulae XXIXa and / or XXXa is / are preferably employed in the LC media according to the invention in amounts of 0-15% by weight, particularly preferably 1-10% by weight.

[0334] The LC medium may further comprise one or more compounds of the following

[0335] 35 pyrimidine or pyridine compounds of the following formulae: Foreignfiling text P24-166-SEC-WO01

[0336] 15 in which R have the meanings indicated in the Formula II and Y^, respectively. R1 preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. X^ preferably denotes F, CF3 , CHF2 , OCHF2 or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl,

[0337] 20 very preferably F and Y^ preferably denotes H. The medium according to the invention particularly may optionally comprise one or more compounds of the Formula XXXI-1 , in which X^ preferably denotes F. The compound(s) of the Formulae XXXI-1 to XXXI-3 may be employed in the LC media according to the invention in amounts of 1-20% by weight, particularly preferably 1-15% by weight.

[0338] 25

[0339] Compounds of Formula P

[0340] In one preferred embodiment, the LC medium may also comprise one or more compounds of Formula P:

[0341] 35 Foreignfiling text P24-166-SEC-WO01

[0342] 60 in which the individual substituents, on each occurrence identically or differently, and each, independently of one another, have the following meanings:

[0343] R1 and R2 each, independently of one another, denote a H atom, a halogen atom, -CN, -SCN, -NCS, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 to 12 C atoms in

[0344] 15 which one or more non-adjacent CH2 groups are optionally substituted

[0345] 20

[0346] -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom;

[0347] 25 to 1. each, independently of one another, denote H, F or Cl; to yS each, independently of one another, denote a H atom, an alkyl group having 1 to 3 C atoms or an alkenyl group having 2 to 3 C atoms in which one or more non-adjacent CH2groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, preferably H or CH3;

[0348] 35 Foreignfiling text P24-166-SEC-WO01

[0349] 61

[0350] Z1denotes -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2H4-,

[0351] -C2F4-, -CF2CH2-, -CH2CF2-, -CFHCFH-, -CFHCH2-, -CH2CFH-, - CF2CFH-, -CFHCF2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-,

[0352] 5 -C=C- or a single bond; k denotes 0, 1 , 2 or 3.

[0353] The preferred compounds of the Formula P result in LC media having a particularly high clearing point, low rotational viscosity, a broad nematic phase range, high birefringence and an excellent thermal and UV stability.

[0354] Preference is furthermore given to compounds of the Formula P in which k denotes 0, 1 or 2, particularly preferably 0 or 1. Preference is furthermore given to com¬

[0355] 15 pounds of the Formula P in which k denotes 0, 1 or 2, preferably 1 or 2 and very particularly preferably 1.

[0356] A1 in Formula P particularly preferably denotes phenylene-1 ,4-diyl, which may also be mono- or polysubstituted by F, furthermore cyclohexane-1 ,4-diyl, cyclo-

[0357] 20 hexenylene-1 ,4-diyl, tetrahydropyran-2,5-diyl or 1 ,3-dioxane-2,5-diyl.

[0358] 7^ in Formula P particularly preferably denotes -CF2O-, -OCF2- or a single bond, wherein a single bond is particularly preferred.

[0359] 25

[0360] Preference is furthermore given to compounds of the Formula P in which R1 and R2 each, independently of one another, denote H, F, Cl, -CN, -SCN, -NCS, SF5, halogen, or alkyl, alkenyl or alkynyl having up to 8, preferably up to 5 C atoms, each of which is optionally substituted by halogen, in particular by F.

[0361] Particularly preferred groups R^ and R^ in Formula P denote H, halogen, or alkyl, alkenyl, alkynyl or alkoxy having up to 12, preferably up to 8 C atoms, each of which is optionally substituted by halogen, in particular by F, particularly preferred are H, F, alkyl, alkenyl or alkynyl having up to 8 C atoms. Preferably, at least one group is not

[0362] 35 H, particularly preferably both groups R1 and R2 are not H. R1 is very particularly Foreignfiling text P24-166-SEC-WO01

[0363] 62 preferably equal to alkyl. R2 is furthermore preferably H, alkyl, alkyl which is substituted by at least one fluorine or fluorine. Very particularly preferably, F is alkyl and R2 is H or alkyl. R1, R2 each, independently of one another, very

[0364] 5 particularly preferably denote unbranched alkyl having 1 to 5 C atoms. If R1 and R2 denote substituted alkyl, alkoxy, alkenyl or alkynyl, the total number of C atoms in the two groups R^ and R^ is preferably less than 10.

[0365] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl and n-octyl.

[0366] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl and pentenyl.

[0367] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl,

[0368] 15 hexynyl, heptynyl and octynyl.

[0369] Preferred alkoxy groups are, for example, methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy.

[0370] 20 Halogen preferably denotes F or Cl, F being mostly preferred.

[0371] Particularly preferred compounds of the Formula P are those selected from the following sub-formulae:

[0372] 35 Foreignfiling_text P24-166-SEC-WO01

[0373] 63

[0374] Formula P.

[0375] In a preferred embodiment,

[0376] 30

[0377] R1an alkyl or an alkoxy group having 1 to 6 C atoms or an alkenyl or an alkenyloxy group having 2 to 6 C atoms in which one or more CH2 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, Foreignfiling text P24-166-SEC-WO01

[0378] 64 such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be substituted by a halogen atom;

[0379] 5

[0380] R2a halogen atom, -CN, -SCN, -NCS, an alkyl or an alkoxy group having

[0381] 1 to 6 C atoms or an alkenyloxy or an alkenyl group having 2 to 6 C atoms in which one or more CH2 groups are optionally substituted such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be substituted by a halogen atom;

[0382] 15 and Y2each, independently from one another, denote a H atom or a methyl group, preferably a H atom; and to L® each, independently from one another, denote a H atom, F or Cl.

[0383] 20

[0384] R1 and R2may denote optionally fluorinated alkyl or alkoxy having 1 to 12 C atoms, optionally fluorinated alkenyl or alkynyl having 2 to 12 C atoms, optionally fluorinated cycloalkyl having 3 to 12 C atoms. and Y2are preferably a H atom or a methyl

[0385] 25 group.

[0386] Particularly preferred are optionally fluorinated alkyl, alkenyl or alkynyl having up to 5 C atoms. L2in the Formulae P-1-1 to P-1-6 preferably denotes F. In the Formulae P-1-4 to P-1-6, l_3 to l_6 preferably denote H.

[0387] In a particularly preferred embodiment, the compounds of Formula P are selected from the following structures:

[0388] 35 Foreignfiling text P24-166-SEC-WO01

[0389] 65

[0390] 5 where R1 has the same meaning as in the general Formula P;

[0391] R2 denotes a straight-chain or branched alkyl or alkoxy group having

[0392] 1 to 6 C atoms, or an akenyl, alkenyloxy, alkoxyalkyl group having

[0393] 2 to 6 C atoms, or a cycloalkyl or a cycloalkoxy group having 3 to

[0394] 12 C atoms, in which one or more non-adjacent CH2 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, -CH=CH-,

[0395] 15 or -O-CO- in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be substituted by a halogen atom; alternatively,

[0396] 20

[0397] R2 is X°, wherein

[0398] X0 a F atom or an alkyl or an alkoxy group having 1 to 3 C atoms or an alkenyl or an alkenyloxy group having 2 or 3 C atoms in which one or

[0399] 25 more H atoms are replaced by a F atom; and and l_2 both denote a F atom or, alternatively, denotes a F atom and L denotes a H atom; and each, independently from one another, denote a H atom or a straightchain or branched alkyl group having 1 to 3 C atoms.

[0400] LC media according to the present invention having a particularly advantageous

[0401] 35 properties are obtainable with the following compounds of the general Formula P: Foreignfiling text P24-166-SEC-WO01 Foreignfiling text P24-166-SEC-WO01 5 Foreignfiling_text P24-166-SEC-WO01

[0402] 68

[0403] 35 Foreignfiling_text P24-166-SEC-WO01

[0404] 69

[0405] 35 Foreignfiling text P24-166-SEC-WO01

[0406] 20 wherein Y^ , Y^, R1 and R2 are as defined above.

[0407] In one preferred embodiment of the present invention, the LC medium comprises one or more compound of Formula P-2-4 and / or one or more compound of Formula P-2-7.

[0408] 25

[0409] In yet a further preferred embodiment, LC media comprise the following compounds of Formula P: Foreignfilingjext P24-166-SEC-WO01

[0410] 71 Foreignfiling_text P24-166-SEC-WO01

[0411] 72 Foreignfilingjext P24-166-SEC-WO01

[0412] 73 Foreignfiling text P24-166-SEC-WO01

[0413] 15 wherein n and m each, independently of one another, denote 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

[0414] Mostly preferred compounds of Formula P include, in particular, one or more of the 0 following: 5 Foreignfiling text P24-166-SEC-WO01

[0415] 75

[0416] 35 Foreignfiling text P24-166-SEC-WO01

[0417] 76 Foreignfiling ext P24-166-SEC-WO01

[0418] 77

[0419] 20

[0420] 25

[0421] As a further possibility, the following compounds of Formula P can be used:

[0422] 35 Foreignfilingjext P24-166-SEC-WO01

[0423] 78 Foreignfilingjext P24-166-SEC-WO01

[0424] 79 Foreignfiling text P24-166-SEC-WO01

[0425] 80 5 As a further possibility, the following compounds of Formula P can be used: 5 Foreignfiling text P24-166-SEC-WO01 5 Foreig nfi li ng_text P24-166-SEC-WO01

[0426] 82 Foreignfiling text P24-166-SEC-WO01

[0427] 83

[0428] 15 5

[0429] Very preferred are the compounds of formulae P-3-9-2 and P-3-5-1.

[0430] The proportion of the compounds of Formula P or its subformulae in the LC medium may range from 0 to 40%, very preferably from 1 to 30%, most preferably from 2 to 20% by weight.

[0431] Compounds of Formula B 5 Foreignfiling text P24-166-SEC-WO01

[0432] 84

[0433] In a further preferred embodiment, the LC medium may further comprise one or more compounds of Formula B: in which the individual substituents, on each occurrence identically or differently, and wherein

[0434] 20 R1 and R^ each, independently of one another, denote one of the meanings given for R1 and R2 in the Formula P;

[0435] -CH2O-, -O-, -C2H4-, -OCH2-, or a single bond;

[0436] Y1-CH2-, -CH2CH2-, -CH=CH-, -CH2O-, -O- or -S-;

[0437] 25 and l_2 H, F or Cl, preferably H or F, very preferably F; k 0 or 1.

[0438] In a preferred embodiment of the present invention, the one or more compounds of the Formula B is selected from the following subformulae:

[0439] 35 Foreignfiling text P24-166-SEC-WO01

[0440] 85 wherein Y^ , U , l_2, R1 and R2 have the meanings given in the Formula B.

[0441] Preferred compounds of the Formula B1 are selected from the following subformulae:

[0442] 20 wherein R^ and R^ independently denote a straight-chain alkyl group having 1 to 6 C atoms, in which one or more CH2 groups are optionally substituted by -C=C-,

[0443] 35 Foreignfiling text P24-166-SEC-WO01 , -O-, -CO-O- or -O-CO- in such a way that O atoms are not linked

[0444] 5 directly to one another, and in which one or more H atoms may be replaced by a halogen atom.

[0445] Very preferred are compounds of the Formula B1-1 and B1-2 wherein both groups (O) denote an oxygen atom and R1 and R2 independently denote an alkyl group being methyl, ethyl, propyl, butyl, pentyl or hexyl, which are preferably straight- chained. Very preferably one “alkyl" is ethyl and the other “alkyl*" is n-pentyl.

[0446] Particularly preferred are compounds of the Formula B1-2.

[0447] 15

[0448] Preferably, the compounds of the Formula B1-1 are selected from the group of compounds of the Formulae B1-1-1 to B1-1-11 , preferably of the Formula B1-1-6:

[0449] 20

[0450] 35 Foreignfiling text P24-166-SEC-WO01

[0451] 87

[0452] 20

[0453] 25 in which

[0454] “alkyl" and “alkyl*" each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms,

[0455] “alkenyl" and “alkenyl*" each, independently of one another, denote a straight-chain alkenyl group having 2 to 6 C atoms,

[0456] “alkoxy” and “alkoxy*" each, independently of one another, denote a straight-chain alkoxy group having 1 to 6 C atoms.

[0457] 35 Foreignfiling text P24-166-SEC-WO01

[0458] 88

[0459] Preferably, the compounds of the Formula B1-2 are selected from the group of compounds of Formulae B1-2-1 to B1-2-10, preferably of Formula B1-2-6:

[0460] 20

[0461] 35 Foreignfiling text P24-166-SEC-WO01

[0462] 89 in which

[0463] “alkyl" and “alkyl*" each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms,

[0464] “alkenyl" and “alkenyl*" each, independently of one another, denote a straight-chain alkenyl group having 2 to 6 C atoms,

[0465] “alkoxy” and “alkoxy*" each, independently of one another, denote a straight-chain

[0466] 15 alkoxy group having 1 to 6 C atoms.

[0467] Optionally, the LC medium comprises one or more compounds of the Formula B1- 1A and / or B1-2A:

[0468] 20

[0469] B1-2A

[0470] 25 in which

[0471] (O) denotes O or a single bond,

[0472] RIHA denotes alkyl or alkenyl having up to 7 C atoms or a group Cy- CmH2m+1'’ m and n are, identically or differently, 0, 1 , 2, 3, 4, 5 or 6, preferably 1 , 2 or 3, very preferably 1 ,

[0473] Cy denotes a cycloaliphatic group having 3, 4 or 5 ring atoms, which is

[0474] 35 optionally substituted with alkyl or alkenyl each having up to 3 C atoms, Foreignfiling text P24-166-SEC-WO01

[0475] 90 or with halogen or CN, and preferably denotes cyclopropyl, cyclobutyl or cyclopentyl.

[0476] The compounds of the Formulae B1-1A and / or B1-2A are contained in the medium

[0477] 5 either alternatively or in addition to the compounds of the Formulae B1-1 and B1-2, preferably additionally.

[0478] Preferred compounds of the Formulae B1-1A and / or B1-2A are also the following: in which alkoxy denotes a straight-chain alkoxy group having 1 to 6 C atoms or alternatively -(CH2)nF in which n is 2, 3, 4, or 5, preferably C2H4F.

[0479] The proportion of the compounds of the Formula B1 or its subformulae in the LC

[0480] 35 medium is preferably from 1 to 20%, very preferably from 1 to 15% by weight. Foreignfiling text P24-166-SEC-WO01

[0481] Preferably, the LC medium contains 1 , 2 or 3 compounds of the Formula B1 or its subformulae.

[0482] 5 In a preferred embodiment of the present invention, the LC medium may comprise one or more compounds of the Formula B2-2 in which

[0483] R1 and R^ identically or differently, denote H, an alkyl or alkoxy group having 1 to

[0484] 6 C atoms, in which one or more CH2 groups in these groups are optionally replaced, independently of one another, by -C=C-, -CF2O-, -OCF2-, -CH=CH-,

[0485] 15 or -O-CO- in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen.

[0486] 20

[0487] The compounds of the Formula B2-2 are preferably selected from the group of compounds of the Formulae B2-2-1 to B2-2-10:

[0488] 35 Foreignfiling text P24-166-SEC-WO01

[0489] 92

[0490] 20

[0491] 25 in which R2 denotes alkyl having 1 to 6 C-atoms, preferably ethyl, n-propyl or n- butyl, or alternatively cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl or alternatively -(CH2)nF in which n is 2, 3, 4, or 5, preferably C2H4F.

[0492] Particularly preferred compounds of the Formula B2 are selected from the following subformulae:

[0493] 35 Foreignfiling text P24-166-SEC-WO01

[0494] The proportion of the compounds of the Formula B2 or its subformulae in the LC medium is preferably from 1 to 20%, very preferably from 1 to 15% by weight.

[0495] 15

[0496] Preferably, the LC medium contains 1, 2 or 3 compounds of the Formula B2 or its subformulae.

[0497] Preferred compounds of the Formula B3 are selected from the following

[0498] 20 subformulae:

[0499] 25

[0500] 30 wherein R1 has one of the meanings given in the Formula B3 and preferably denotes straight-chain alkyl having 1 to 6 C atoms, very preferably methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably ethyl or propyl, most preferably propyl, has one of the meanings given in the Formula B3 and preferably denotes CF3, CHF2, OCF3or OCHF2.

[0501] 35 Foreignfiling text P24-166-SEC-WO01

[0502] 94

[0503] Preferred compounds of the Formula B3 are selected from the following subformulae: wherein R1 has one of the meanings given in the Formula B3 and preferably

[0504] 20 denotes straight-chain alkyl having 1 to 6 C atoms, very preferably methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably ethyl or propyl, most preferably propyl.

[0505] Most preferred compound of the Formula B3-2-2 is B3-2-2-1.

[0506] 25

[0507] In a preferred embodiment, the LC medium contains one or more compounds of the Formula B or its subformulae B1, B2, B3, B1-1, B1-2, B2-1 , B2-2, B2-3, B3-1, B3-2, B3-1-1 , B3-1-2, B3-2-1 and B3-2-2 wherein the dibenzofuran or dibenzothiophene group is substituted by a methyl or methoxy group, preferably by a methyl group, preferably in p-position to the substituent F, very preferably in p-position to the

[0508] 35 substituent F ( / .e. in m-position to the terminal group R2 or X^). Foreignfiling text P24-166-SEC-WO01

[0509] 95

[0510] The proportion of the compounds of the Formula B3 or its subformulae in the LC medium is preferably from 1 to 20%, very preferably from 1 to 10% by weight.

[0511] 5 Preferably, the LC medium contains 1, 2 or 3 compounds of the Formula B3 or its subformulae.

[0512] Preferably, the total proportion of compounds of the Formula B or their subformulae in the LC medium is from 2 to 25%, very preferably from 3 to 20% by weight.

[0513] Further components

[0514] In some preferred embodiments, the LC medium may additionally comprise or more compounds of the Formulae YA, YB, YC, YD, YE and YF:

[0515] 15

[0516] 35 Foreignfiling text P24-166-SEC-WO01

[0517] 96 in which the individual substituents have the following meanings:

[0518] R21 and R^2 each, independently of one another, denote a H atom, a halogen atom, -CN, -SCN, -NCS, an alkyl or an alkoxy group having 1 to 12 C

[0519] 15 atoms or an alkenyl or an alkenyloxy group having 2 to 12 C atoms in which one or more non-adjacent CH2 groups are optionally substituted

[0520] 20 such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom, and wherein in

[0521] 25 the Formula YD R21 is different from cyclic alkyl or alkoxy;

[0522] U to l_3 each, independently of one another, denote F, Cl, CF3 or CHF2;

[0523] R23 denotes a H atom, an alkyl group having 1 to 3 C atoms or an alkenyl group having 2 to 3 C atoms in which one or more non-adjacent CH2groups are optionally substituted by -C=C-, -CF2O-,

[0524] -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, preferably H or CH3;

[0525] 35 Foreignfiling text P24-166-SEC-WO01

[0526] 97

[0527] 7^ and 7?- each, independently of one another, denote a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CH=CHCH2O;

[0528] 5 p 0, 1 or 2; and q 0 or 1.

[0529] In a preferred embodiment, the one or more compounds of Formula YA may be selected from one of the following:

[0530] 15

[0531] 20

[0532] 35 Foreignfiling text P24-166-SEC-WO01

[0533] 20

[0534] 35 Foreignfiling text P24-166-SEC-WO01

[0535] 99

[0536] 20

[0537] 35 Foreignfiling text P24-166-SEC-WO01

[0538] 100

[0539] 35 Foreignfiling text P24-166-SEC-WO01

[0540] 101

[0541] 35 Foreignfiling text P24-166-SEC-WO01

[0542] 102

[0543] 20

[0544] 35 Foreignfiling text P24-166-SEC-WO01

[0545] 103

[0546] 20 Foreignfiling text P24-166-SEC-WO01

[0547] 104

[0548] 35 Foreignfilingjext P24-166-SEC-WO01

[0549] 105 Foreignfiling text P24-166-SEC-WO01

[0550] 106

[0551] 20

[0552] 25

[0553] 35 Foreignfiling text P24-166-SEC-WO01

[0554] 107 , alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms, alkenyl denotes a straight-chain alkenyl group having 2 to 6 C atoms, and

[0555] (O) denotes an oxygen atom or a single bond, and

[0556] 15 alkenyl preferably denotes CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-

[0557] CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or

[0558] CH3-CH=CH-(CH2)2-.

[0559] 20

[0560] Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of formulae YA-2, YA-8, YA-10, YA- 16, YA-18, YA-40, YA-41, YA-42, YA-43, YA-77 and YA-78.

[0561] 25 Preferably, the one or more compounds of Formula YA-2 are preferably selected from the following subformulae:

[0562] 35 Foreignfiling text P24-166-SEC-WO01

[0563] Alternatively, preferably in addition to the compounds of the formulae YA-2-1 to YA- 2-5, the LC medium comprises one or more compounds of the following formulae:

[0564] 15

[0565] 20

[0566] 35 Foreignfiling text P24-166-SEC-WO01

[0567] 109

[0568] 5

[0569] Further preferably, the LC medium comprises one or more compounds of the formula YA-10 selected from the following sub-formulae:

[0570] 25

[0571] Alternatively, preferably in addition to the compounds of the formulae YA-10-1 to YA-10-5, the LC medium comprises one or more compounds of the following formulae:

[0572] 35 Foreignfiling text P24-166-SEC-WO01

[0573] 110

[0574] 2

[0575] Further preferably, the LC medium comprises one or more compounds of the formula YA-40 selected from the following sub-formulae:

[0576] 35 Foreignfiling text P24-166-SEC-WO01

[0577] 111

[0578] Alternatively, preferably in addition to the compounds of the formulae YA-40-1 to YA- 40-5, the LC medium comprises one or more compounds of the following formulae:

[0579] 35 Foreignfiling text P24-166-SEC-WO01

[0580] 112

[0581] 5

[0582] Further preferably, the LC medium comprises one or more compounds of the formula YA-42 selected from the following sub-formulae:

[0583] 25

[0584] Further preferably, the LC medium comprises one or more compounds of the formula YA-66 selected from the following subformulae:

[0585] YA-66-1

[0586] 35 Foreignfiling text P24-166-SEC-WO01

[0587] 113

[0588] Further preferably, the LC medium comprises one or more compounds of the formula

[0589] 20 YA-67 selected from the following sub-formulae:

[0590] 35 Foreignfiling text P24-166-SEC-WO01

[0591] 114

[0592] 15 Further preferably, the LC medium comprises one or more compounds of the formula YA-77 selected from the following sub-formulae:

[0593] 35 Foreignfiling text P24-166-SEC-WO01

[0594] 115

[0595] 5

[0596] In another preferred embodiment, the LC medium comprises one or more compounds of the formula YB selected from the group consisting of formulae YB-1 to YB-26 Foreignfiling text P24-166-SEC-WO01

[0597] 116

[0598] 1 5 Foreignfiling text P24-166-SEC-WO01

[0599] 117

[0600] 20

[0601] YB-24 Foreignfiling text P24-166-SEC-WO01

[0602] 118 in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2 to 6 C atoms, and

[0603] 15

[0604] (O) denotes an oxygen atom or a single bond, and alkenyl preferably denotes CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-

[0605] CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or

[0606] CH3-CH=CH-(CH2)2-.

[0607] 20

[0608] Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of formulae YB-2, YB-11 and YB-17.

[0609] 25 Preferably, the LC medium comprises one or more compounds of the formula YB-11 selected from the following sub-formulae:

[0610] 35 Foreignfiling text P24-166-SEC-WO01

[0611] 119

[0612] Alternatively, preferably in addition to the compounds of the formulae YB-11-1 to YB-11-5, the LC medium comprises one or more compounds of the following formulae:

[0613] 15

[0614] 35 Foreignfiling text P24-166-SEC-WO01

[0615] 120

[0616] 5

[0617] Preferably, the LC medium comprises one or more compounds of the formula YB-17 selected from the following sub-formulae:

[0618] 15

[0619] In another preferred embodiment the LC medium comprises one or more compounds of the formula YC selected from the formula YC-1, in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms.

[0620] 25

[0621] In another preferred embodiment, the LC medium comprises one or more compounds of the formula YD selected from the group consisting of the following formulae Foreignfiling text P24-166-SEC-WO01

[0622] 35 Foreignfiling text P24-166-SEC-WO01

[0623] 122

[0624] 20 Foreignfiling_text P24-166-SEC-WO01

[0625] 123

[0626] 10 Foreignfiling text P24-166-SEC-WO01

[0627] 124 in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms, alkenyl denotes a straight-chain alkenyl group having 2 to 6 C atoms,

[0628] (O) denotes an oxygen atom or a single bond,

[0629] 15

[0630] Y denotes H or CH3and alkenyl preferably denotes CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2- CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or

[0631] 20 CH3-CH=CH-(CH2)2-.

[0632] Further preferred LC media according to the invention comprise one or more compounds of the formula YD-1 and / or YD-4.

[0633] 25

[0634] Further preferred LC media according to the invention comprise one or more compounds of the formula YD, wherein q is 0, Y is H and R^2 denotes an alkyl or alkoxy radical having 1 to 6 C atoms wherein one CH2group is optionally replaced by a cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl group, preferably selected from formulae YD-1, YD-15, YD-16, YD-17, YD-18, YD-19, YD-20, YD-21 , YD-22 and YD-23, very preferably selected from formulae YD-1, YD-16, YD-21, YD-22 and YD-23.

[0635] Very preferred compounds of the formula YD are compounds selected from the following subformulae

[0636] 35 Foreignfiling text P24-166-SEC-WO01 Foreignfilingjext P24-166-SEC-WO01

[0637] 126 Foreignfiling_text P24-166-SEC-WO01

[0638] 127

[0639] 10

[0640] 15

[0641] 20 Foreignfiling text P24-166-SEC-WO01

[0642] 128

[0643] 15 5 Foreignfiling text P24-166-SEC-WO01

[0644] 15 wherein v is 1 , 2, 3, 4, 5 or 6.

[0645] In a preferred embodiment, the LC medium comprises one or more compounds of the formula YE selected from the group consisting of the following formulae:

[0646] 20

[0647] 35 Foreignfiling text P24-166-SEC-WO01

[0648] 130

[0649] YE- 10

[0650] 20

[0651] 35 Foreignfiling text P24-166-SEC-WO01

[0652] 131

[0653] 15 5 Foreignfiling text P24-166-SEC-WO01

[0654] 132 , alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms, alkenyl denotes a straight-chain alkenyl group having 2 to 6 C atoms, and

[0655] (O) denotes an oxygen atom or a single bond, and alkenyl preferably denotes CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or

[0656] 15 CH3-CH=CH-(CH2)2-.

[0657] Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of formulae YE-2, YE-8, YE-10, YE- 16, YE-18.

[0658] 20

[0659] Preferably, the LC medium comprises one or more compounds of the formula YE-2 selected from the following sub-formulae:

[0660] 35 Foreignfiling text P24-166-SEC-WO01

[0661] Preferably, the LC medium comprises one or more compounds of the formula YE-10 selected from the following sub-formulae:

[0662] 25

[0663] In another preferred embodiment, the LC medium comprises one or more compounds of the formula YF selected from the group consisting of the following formulae:

[0664] 35 Foreignfiling text P24-166-SEC-WO01

[0665] 134

[0666] 5 in which alkyl and alkyl* each, independently of one another, denote a straight-chain or branched alkyl group having 1 to 6 C atoms.

[0667] Preferably, the LC medium comprises one or more compounds of the formula YF-2 selected from the following sub-formulae:

[0668] 15

[0669] 20

[0670] Particularly preferred, LC media according to the invention comprise one or more compounds selected from the formulae YA-2, YA-8, YA-10, YA-16, YA-18, YA-40, YA-41 , YA-42, YA-43, YA-66, YA-67, YA-77, YB-2, YB-11, YB-16, YC-1 , YD-1 , YD- 4, YD-10, YD-16, YE-2, YE-8, YE-10, YE-16, YE-18, YE-37, YE-38, YE-39, YE-40

[0671] 35 and YF-2 or their subformulae. Foreignfiling text P24-166-SEC-WO01

[0672] 135

[0673] The total content of the compounds of Formulae YA to YF in the LC medium preferably ranges from 0 % to 15 % by weight, more preferably from 0.5 % to 10 % by weight.

[0674] 5

[0675] In addition to the compounds of the Formula S, the LC medium preferably contains one or more compounds of the Formulae N1 and N2:

[0676] 15 in which

[0677] R41 and R^2 each, independently of one another, denote an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 to 12 C atoms in which one or more non-adjacent CH2

[0678] 20 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-,

[0679] 25 such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom, preferably R^1 denotes alkyl and R42 denotes alkyl or alkoxy or R^1 denotes alkenyl and R^2 denotes alkyl, wherein one -CH2- group may be replaced by cyclopropylene, 1,3-cyclobutylene, 1 ,3- cyclopentylene, 1,3-cyclopentenylene, preferably by cyclopropylene or 1,3-cyclopentylene,

[0680] 35 Foreignfiling text P24-166-SEC-WO01

[0681] 136

[0682] 5 also these independently of one another, denote denotes or denote,

[0683] Z^1 and z42 independently of one another and, if Z^1 occurs twice, also these independently of one another, denote -CH2CH2-, -COO-, trans- CH=CH-, frans-CF=CF-, -CH2O-, -CF2O-, -C=C- or a single bond,

[0684] 35 preferably one or more thereof denotes / denote a single bond, and Foreignfiling text P24-166-SEC-WO01

[0685] 137 p denotes 0, 1 or 2, preferably 0 or 1 , and

[0686] R51 and R 2 independently of one another, have one of the meanings given

[0687] 5 for R41 and R42 and preferably denote alkyl having 1 to 12 C atoms, preferably n-alkyl, particularly preferably n-alkyl having 1 to 6 C atoms, alkoxy having 1 to 6 C atoms, preferably n- alkoxy, particularly preferably n-alkoxy having 2 to 6 C atoms, alkoxyalkyl, alkenyl or alkenyloxy having 2 to 6 C atoms, preferably having 2 to 4 C atoms, preferably alkenyloxy, wherein one -CH2- group may be replaced by cyclopropylene, 1 ,3-cyclobutylene, 1 ,3-cyclopentylene, 1 ,3-cyclo-pentenylene, preferably by cyclopropylene or 1 ,3-cyclopentylene,

[0688] 15 if present, each, independently of one another, denote

[0689] 20 preferably

[0690] 35 Foreignfiling text P24-166-SEC-WO01

[0691] 138 preferably preferably denotes

[0692] 20 z51 f0£53 each, independently of one another, denote -CH2-CH2-, -CH2-O-, -CH=CH-, -C=C-, -COO- or a single bond, preferably -CH2-CH2-, - CH2-O- or a single bond and particularly preferably a single bond, i and j each, independently of one another, denote 0 or 1 ,

[0693] 25 preferably denotes 0, 1 or 2, more preferably 0 or 1 and, most preferably, 1, and wherein the one or more, preferably one, of the aromatic rings present may optionally be substituted by an alkyl group, preferably by methyl.

[0694] In some embodiments, the compound of Formula N1 is represented by one of the following formulae:

[0695] 35 Foreignfiling text P24-166-SEC-WO01

[0696] 139 Foreignfiling text P24-166-SEC-WO01

[0697] 140

[0698] 5 wherein

[0699] "alkyl" and "alkyl*" each, independently from one another, denote an alkyl group having 1 to 6 C atoms;

[0700] "alkenyl" and "alkenyl*" each, independently of one another, denote an alkenyl group having 2 to 6 C atoms.

[0701] Very preferred are compounds of the Formula Z1 and Z2.

[0702] 15 Preferred compounds of the Formulae Z1 to Z11 are those selected from the following subformulae: Z1-1

[0703] 20

[0704] Z1-2

[0705] 35 Foreignfiling text P24-166-SEC-WO01

[0706] 141

[0707] 35 Foreignfiling text P24-166-SEC-WO01

[0708] 142

[0709] 15 In another preferred embodiment, the LC medium contains one or more compounds of the Formula Z1 or its preferred subformulae and / or one or more compounds selected from the Formulae Z2, Z3, Z4 and Z5 or their preferred subformulae.

[0710] Preferably, the total proportion of compounds of the Formula Z1, Z2, Z3, Z4, Z5 and

[0711] 20 Z6 or their subformulae, such as CC-3-V in the medium is from 10 to 65%, very preferably from 20 to 60%, most preferably from 25 to 55% by weight. In yet a more preferred embodiment, the compound of the Formula Z1-1 is used in concentrations ranging from 10 wt.-% to 60 wt.-%, more preferably 25 wt.-% to 50 wt.-%, based on the total weight of the LC medium. In a further preferred embodiment, the LC

[0712] 25 medium comprises 50 wt.-% to 70 wt.-% of compounds represented by the Formulae Z1-1 and Z4-2 in total.

[0713] Preferably, the medium contains 1 , 2 or 3 compounds selected from the Formulae Z1 , Z2, Z3 and Z4 or their subformulae.

[0714] The LC medium may additionally comprise one or more compounds of the following general formulae:

[0715] 35 Foreignfiling text P24-166-SEC-WO01

[0716] 143

[0717] 5 in which

[0718] R1 and R2 each, independently from one another, denote C-|_0-alkyl, C1.5- alkoxy or C2-6-alkenyl.

[0719] The compounds of the Formula XI are preferably selected from the following wherein “alkyl" and “alkyl*" each, independently from one another, denote methyl, ethyl, propyl, butyl, pentyl or hexyl.

[0720] 25

[0721] The LC medium may additionally comprise one or more compounds of the following general formulae:

[0722] 35 Foreignfiling text P24-166-SEC-WO01

[0723] 144

[0724] R1 and R2 each, independently from one another, denote C-|_0-alkyl, C1.5- alkoxy or C2-6'alkenyl.

[0725] The LC medium may additionally comprise one or more compounds of the following

[0726] 5 general formulae: in which

[0727] R1 and R^ each, independently from one another, denote Ci-g-alkyl, CI.Q- alkoxy or C2-6-alkenyl.

[0728] 15 The compounds of the Formula XII are preferably selected from the following subformulae:

[0729] 20

[0730] Xll-1d wherein “alkyl" and “alkyl*" each, independently from one another, denote methyl, ethyl, propyl, butyl, pentyl or hexyl.

[0731] Particular preference is given to the compounds of the Formulae Xll-1a and XII-1 c. In the Formula XI 1-1 b, "alkyl" preferably, independently of one another, denotes n-CsHy,

[0732] 35 Foreignfiling text P24-166-SEC-WO01 n-CztHg or n-CsH^ , in particular n-CgHy. In the Formula XI 1-1 c, "alkyl" preferably denotes n-CgHy and "alkyl*" is preferably CH3 or n-CgHy.

[0733] Particularly preferred compounds of the Formula XI 1-1 are described by the

[0734] 5 following structures:

[0735] In a further embodiment, the compound of Formula XII may be represented by the

[0736] 25 following Formula XII-2: in which

[0737] R1 and R^ each, independently from one another, denote Ci-g-alkyl, CI.Q- alkoxy or C2-6-alkenyl.

[0738] 35 Foreignfiling text P24-166-SEC-WO01

[0739] 146

[0740] The compounds of the Formula XII-2 may be selected from the following

[0741] In a further embodiment, the compound of Formula XII may be represented by the 3 in which

[0742] 15 R1 and R^ each, independently from one another, denote Ci-g-alkyl, C-i.g- alkoxy or C2-6-alkenyl.

[0743] The compounds of the Formula XII-3 may be selected from the following subformulae:

[0744] 20

[0745] 25

[0746] The LC medium may additionally comprise one or more compounds selected from the following formulae:

[0747] XIV

[0748] 35 Foreignfiling text P24-166-SEC-WO01

[0749] 5 in which and L have the meanings indicated in the Formula III, and F and R^ each, independently of one another, denote n-alkyl, cycloalkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms, and preferably each, independently of one another, denote alkyl having 1 to 6 C atoms; in the compound of the Formula XIV, at least one of the substituents R1 and R2 preferably denotes alkenyl having 2 to 6 C atoms.

[0750] The LC medium may further optionally comprise one or more compounds of the

[0751] 15 Formula XIV in which at least one of the substituents R^ and R^ denotes alkenyl having 2 to 6 C atoms, preferably those selected from the following subformulae: XlVa

[0752] 20

[0753] 25

[0754] XlVd in which "alkyl" and "alkyl*" have the meaning indicated above, and each, independently of one another, preferably denote methyl, ethyl or propyl.

[0755] The compounds of the Formulae XIV are preferably selected from the following subformulae:

[0756] 35 Foreignfiling text P24-166-SEC-WO01

[0757] 148

[0758] Very preferred are compounds of the Formulae XIVd-1 , XIVe-1, XIVe-2 and XIVe-3.

[0759] 20

[0760] The LC medium may further optionally comprise one or more compounds of the Formula XV in which at least one of the substituents R1 and R2 denotes alkyl or alkoxy having 2 to 6 C atoms, preferably those selected from the following subformulae:

[0761] 25 in which "alkyl" and "alkyl*" has the meaning indicated above, and each, independently of one another, preferably denote methyl, ethyl or propyl.

[0762] 35 Foreignfiling text P24-166-SEC-WO01

[0763] 149

[0764] The compounds of the Formulae XV are preferably represented by the following subformula:

[0765] In yet a further embodiment, the LC medium comprises one or more compounds of the Formula XVI:

[0766] XVI in which R1 and R2 have the meanings indicated for R^ in the Formula II, and

[0767] 15 preferably each, independently of one another, denote alkyl having 1 to 6 C atoms. L denotes H or F.

[0768] Particularly preferred compounds of the Formula XVI are those of the subformulae:

[0769] 20

[0770] XVI a

[0771] 35 Foreignfiling text P24-166-SEC-WO01

[0772] 150 in which

[0773] “alkyl" and “alkyl*" each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms, in particular ethyl, propyl or pentyl, and

[0774] “alkenyl" and “alkenyl*" each, independently of one another, denote a straight-chain alkenyl group having 2 to 6 C atoms, in particular CH2=CHC2H4, CH3CH=CHC2H4, CH2=CH and

[0775] 15 CH3CH=CH.

[0776] Particular preference is given to the compounds of the Formulae XVIb and XVIc.

[0777] Very particular preference is given to the compounds of the following subformulae:

[0778] 35 Foreignfiling text P24-166-SEC-WO01

[0779] The total content of the compounds of Formula XVI in the LC medium preferably ranges from 1 to 15 wt.-%, more preferably from 2 to 10 wt.-%.

[0780] In addition, or as an alternative to the compounds of Formula XVI, the following

[0781] 15 compounds of Formulae XVI’-1 or XVI’-2 may be employed:

[0782] 20

[0783] 25 in which

[0784] R° denotes a H atom, an alkyl or an alkoxy group having 1 to 6 C atoms or an alkenyl or an alkenyloxy group having 2 to 6 C atoms in which one or more non-adjacent CH2 groups are optionally substituted or -O-CO- in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a

[0785] 35 halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 6 C Foreignfiling text P24-166-SEC-WO01

[0786] 152 atoms, in which one or more H atoms may be replaced by a halogen atom.

[0787] In yet a further embodiment, the LC medium comprises one or more compounds of the Formula XIII:

[0788] 5 in which R^ and R^ have the meanings indicated for R^ in the Formula II, and preferably each, independently of one another, denote alkyl having 1 to 6 C atoms. L denotes H, F or Cl.

[0789] Particularly preferred compounds of the Formula XIII are those of the subformulae:

[0790] 15

[0791] 20 in which

[0792] “alkyl" and “alkyl*" each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms, in particular ethyl, propyl or pentyl, and

[0793] 35 Foreignfiling text P24-166-SEC-WO01

[0794] 153

[0795] “alkenyl" and “alkenyl*" each, independently of one another, denote a straight-chain alkenyl group having 2 to 6 C atoms, in particular CH2=CHC2H4, CH3CH=CHC2H4, CH2=CH and CH3CH=CH.

[0796] 5

[0797] Particular preference is given to the compounds of the Formulae XI I la and XI 11 b.

[0798] Very particular preference is given to the compounds of the following subformulae:

[0799] 20

[0800] In yet a further embodiment, the LC medium comprises one or more compounds of

[0801] 35 the Formula XIII: Foreignfiling text P24-166-SEC-WO01

[0802] 154

[0803] 5 in which R1 and R2 have the meanings indicated for R^ in the Formula II, and preferably each, independently of one another, denote alkyl having 1 to 6 C atoms. L denotes H, F or Cl.

[0804] Particularly preferred compounds of the Formula XIII are those of the subformulae:

[0805] 25 in which

[0806] “alkyl" and “alkyl*" each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms, in particular ethyl, propyl or pentyl, and

[0807] “alkenyl" and “alkenyl*" each, independently of one another, denote a straight-chain alkenyl group having 2 to 6 C atoms, in particular CH2=CHC2H4, CH3CH=CHC2H4, CH2=CH and CH3CH=CH.

[0808] 35 Foreignfiling text P24-166-SEC-WO01

[0809] 155

[0810] Particular preference is given to the compounds of the Formulae XI I la and XI 11 b.

[0811] Very particular preference is given to the compounds of the following subformulae:

[0812] 20

[0813] The LC medium may optionally comprise one or more compounds of the following

[0814] 35 Foreignfiling text P24-166-SEC-WO01

[0815] 156

[0816] 15 in which

[0817] R1 and R2 have the meanings indicated in the Formula S, respectively, and preferably each, independently of one another, denote alkyl having 1 to 6 C atoms. L denotes H or F.

[0818] 20 Very preferred are compounds of the Formula XVI la, wherein L is H or F. Very preferred are compounds of the Formula XVI I b, wherein L is F.

[0819] The LC medium may additionally comprise one or more compounds of the following formula:

[0820] 25 in which L, R1 and R2 have the meanings indicated in the Formula S for U , R1 and R2, respectively. R^ and R^ preferably denote alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms.

[0821] 35 Foreignfiling text P24-166-SEC-WO01

[0822] 157

[0823] Particularly preferred compounds of the Formula XXXII are those of the subformulae: in which

[0824] “alkyl" and “alkyl*" each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms, in particular ethyl, propyl

[0825] 15 or pentyl, and

[0826] “alkenyl" denotes a straight-chain alkenyl group having 2 to 6 C atoms, in particular CH2=CHC2H4, CH3CH=CHC2H4,

[0827] CH2=CH and CH3CH=CH.

[0828] 20

[0829] Very particular preference is given to the compounds of the following subformulae:

[0830] 35 Foreignfiling text P24-166-SEC-WO01

[0831] 158

[0832] In some further embodiments, the LC medium comprises one or more compounds of the following formulae:

[0833] 15 XXXV in which R1 and R2 each, independently from one another, have the meanings

[0834] 20 indicated in the Formula S for R^ and R^ and preferably each, independently of one another, denote alkyl having 1 to 6 C atoms.

[0835] Very particular preference is given to the compounds of the following subformulae: Foreignfiling text P24-166-SEC-WO01

[0836] 159

[0837] Advantageously, the LC medium of the present invention may comprise one or more compounds of the Formula LP1 and / or one or more compounds of the Formula LP2 in which the individual substituents have the following meanings:

[0838] R° has one of the meanings given in for RO in the Formula II;

[0839] 20

[0840] R2 denote an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by -C=C- t O atoms are not linked directly to one another, and in which one or more H atoms may be substituted by a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms; and l_2 has one of the meanings given in for i and l_2 in the Formula II;

[0841] X0 has one of the meanings given in the Formula II;

[0842] 35 yO denote H or CH3; and Foreignfiling text P24-166-SEC-WO01

[0843] 160 m and n denotes 0 or 1.

[0844] The one or more compounds of the Formulae LP1 and LP2 may be preferably

[0845] 5 described by the following Formulae:

[0846] R° is an alkyl or an alkoxy group having 1 to 6 C atoms or an alkenyl group having 2 to 6 C atoms in which one or more CH2 groups are

[0847] 35 or -O-CO- in such a way that O atoms are not linked directly to one Foreignfiling text P24-166-SEC-WO01

[0848] 161 another, and in which one or more H atoms may be substituted by a halogen atom;

[0849] R2 is an alkyl group having 1 to 6 C atoms, in which one or more CH2

[0850] 5 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, ms are not linked directly to one another, and in which one or more H atoms may be substituted by a halogen atom;

[0851] XO a F atom or an alkyl or an alkoxy group having 1 to 3 C atoms or an

[0852] 15 alkenyl or an alkenyloxy group having 2 or 3 C atoms in which one or more H atoms are replaced by a F atom; and

[0853] Y° H or CH3.

[0854] 20 The compounds of the general Formulae LP1 and LP2 can also be represented by one of the following structures:

[0855] 35 Foreignfiling text P24-166-SEC-WO01

[0856] 162

[0857] LP1j

[0858] 20

[0859] LP1k

[0860] LP2d

[0861] 35 Foreignfiling text P24-166-SEC-WO01

[0862] LP2h in which

[0863] R° is an alkyl or an alkoxy group having 1 to 12 C atoms in which one or

[0864] 15 more CH2 groups are optionally substituted by -C=C-, -CF2O-, toms are

[0865] 20 not linked directly to one another, and in which one or more H atoms may be substituted by a halogen atom, preferably an alkyl group having 1 to 4 C atoms, alkenyl or an alkenyloxy group having 2 to 6 C atoms or a cycloalkyl or a cycloalkyloxy group having 3 to 6 C atoms, wherein vinyl, allyl or cyclopentyl are particularly preferable;

[0866] 25 denotes 1, 2, 3, 4 or 5; and denotes 1, 2, 3 or 4.

[0867] Particularly preferred compounds of the Formula LP1 are those selected from the group consisting of the following subformulae:

[0868] 35 Foreignfiling text P24-166-SEC-WO01

[0869] 164 Foreignfiling text P24-166-SEC-WO01

[0870] 165

[0871] Particularly preferred compounds of the Formula LP2 are those selected from the group consisting of the following subformulae:

[0872] 15

[0873] 35 Foreignfiling text P24-166-SEC-WO01

[0874] 166

[0875] 20 LP2-2b

[0876] Very preferred are compounds of the Formulae LP2-1a, LP2-1b, LP2-1c, LP2-1d, and LP2-1 i, LP2-2b, LP2-3a, LP2-3c mostly preferred is the compound Formula

[0877] 35 LP2-1b. Foreignfiling text P24-166-SEC-WO01

[0878] 167

[0879] Preferably, the LC medium comprises one or more compounds of the Formula LP1 and one or more compounds of the Formula LP2.

[0880] 5 The total proportion of the compounds of the Formula LP1 or its subformulae in the LC medium is preferably from 0.5 to 35%, very preferably from 1 to 25%, mostly preferred from 2 to 15% by weight. The total proportion of the compounds of the Formula LP2 or its subformulae in the LC medium is preferably from 0.5 to 35%, very preferably from 1 to 25%, mostly preferred from 2 to 15% by weight.

[0881] Compounds of Formula ST

[0882] In some preferred embodiments of the present invention, the LC medium may further comprise one or more compounds of the general Formula ST:

[0883] 15

[0884] 20 in which in which the individual substituents have the following meanings:

[0885] 25 x21 x22each, independently of one another, denote -O-, -CH2-, -CHR23- or -N-R23- ,

[0886] R21 and R22each, independently of one another, denote a H atom or an alkyl- or alkoxy group having 1 to 12 C atoms, an alkenyl, alkynyl, alkenyloxy or alkoxyalkyl group having 2 to 12 C atoms or a cycloalkyl group having 3 to 12 C atoms, in which one or more non-adjacent CH2 groups are

[0887] 35 Foreignfiling text P24-166-SEC-WO01

[0888] 168

[0889] 5 or -O-CO- in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be substituted by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be substituted by a halogen atom,

[0890] R23 denotes a H atom, an alkyl or alkoxy group havingl to 10 C atoms, r denotes 0 or 1.

[0891] LC media comprising compounds of the following sub-formulae ST-1, ST-2 and ST-

[0892] 3 showed a particularly high long-term thermal and UV stability:

[0893] 15

[0894] 20

[0895] 35 Foreignfiling text P24-166-SEC-WO01

[0896] ST-4

[0897] 5 in which the individual substituents have the following meanings:

[0898] R21 and R22 each, independently of one another, denote a H atom or an alkyl or

[0899] 15 alkoxy group having 1 to 7 C atoms, and r denotes 0 or 1.

[0900] In particularly preferred embodiments, the compounds of the general Formula ST can be selected from the following specific structures:

[0901] 20

[0902] 35 Foreignfiling_text P24-166-SEC-WO01

[0903] 170 Foreignfilingjext P24-166-SEC-WO01

[0904] 171 Foreignfiling_text P24-166-SEC-WO01

[0905] 172 Foreignfiling text P24-166-SEC-WO01

[0906] 173

[0907] Typically, the LC medium of the present invention comprises 10 to 10 000 ppm by

[0908] 20 weight, more preferably 50 to 5 000 ppm by weight, even more preferably 100 to 1 000 ppm by weight of one or more compounds of Formula ST.

[0909] In a further preferred embodiment, the LC medium according to the present invention may comprise at least one further sterically hindered phenol, which is mentioned in Table B below.

[0910] 25

[0911] Compounds of Formula H

[0912] The LC medium may optionally comprise one or more compounds of the Formula H

[0913] 35 Foreignfiling text P24-166-SEC-WO01

[0914] 174 in which

[0915] R11 each, independently of one another, denotes a H atom, F, an alkyl group having 1 to 20 C atoms, in which one -CH2- group or, if

[0916] 5 present, a plurality of -CH2- groups may be substituted by -O- or -C(=O)-, but two adjacent -CH2- groups cannot be substituted by -O-, and one or, if present, a plurality of -CH2- groups may be substituted by -CH=CH- or -C=C-, and in which one H atom or a plurality of H atoms may be substituted by F, ORR15,

[0917] R12 each, independently of one another, denotes a H atom, an alkyl group having 1 to 20 C atoms, in which one -CH2- group or a plurality of -

[0918] 15 CH2- groups may be substituted by -O- or -C(=O)-, but two adjacent - CH2- groups cannot be substituted by -O-, a hydrocarbon group which contains a cycloalkyl or alkylcycloalkyl unit and in which one - CH2- group or a plurality of -CH2- groups may be substituted by -O-

[0919] 20 or -C(=O)-, but two adjacent -CH2- groups cannot be substituted by -O-, and in which one H atom or a plurality of H atoms may be substituted aromatic or heteroaromatic hydrocarbon group, in which one H atom or a plurality of H atoms may be substituted by OR^, N(R13)(R14) or R^S

[0920] 25

[0921] R13 and R^ each, independently of one another, denotes an alkyl or acyl group having 1 to 10 C atoms or an aromatic hydrocarbon or carboxylic acid group having 6 to 12 C atoms,

[0922] R15 each, independently of one another, denotes an alkyl group having 1 to 10 C atoms, in which one -CH2- group or a plurality of -CH2- groups may be substituted by -O- or -C(=O)-, but two adjacent -CH2- groups cannot be substituted by -O-,

[0923] 35 Foreignfiling text P24-166-SEC-WO01

[0924] 175

[0925] R16 each, independently of one another a H atom, an alkyl group or an alkoxy group having 1 to 10 C atoms, O-cycloalkyl group having 3 to 12 C atoms, O’ or OH,

[0926] 5 p denotes 1 or 2, q denotes 0 or 1, o denotes (3-p), n denotes an integer from 1 to 10, m denotes an integer from 0 to 8, wherein

[0927] 30 n * p denotes an integer from 1 to 10, preferably from 3 to 8, and denotes an organic moiety having (m+n) bonding sites,

[0928] 35 Foreignfiling text P24-166-SEC-WO01

[0929] In some preferred embodiments of the present invention, in the compounds of the Formula H, (benzene-1,2,4,5-tetrayl)

[0930] 15 (benzene-1 ,2,4-triyl),

[0931] 20

[0932] (frans-1 ,4-cyclohexylene) and / or wherein

[0933] 35 Foreignfiling text P24-166-SEC-WO01

[0934] 177

[0935] _Z12_S11-Z11 - on each occurrence, independently of one another, denotes -O-, S1 1-O-, -O-S1 1-O-, -(C=O)-O-S1 1-O-, -O-(C=O)-S1 1-O-, -O-(C=O)-S1 1-(C =O)-O-, -O-S1 1-(C=O)-O-, -(C=O)-O-S1 1-C, -(C=O)-O-S1 1-O-(C=O)- or -(

[0936] 5 N-R13)-S1 1-O-, -(N-R13-C(=O)-S1 1-(C=0)-0 or a single bond, preferably -O-, -S1 1-O-, -O-S1 1-O-, -(C=O)-O-S1 1-O-, -O-(C=O)-S1 1-O- preferably denotes an alkylene group having 1 to 20 C atoms, and / or

[0937] R11 if present, denotes alkyl, alkoxy or H, preferably H or alkyl, and / or

[0938] R12 denotes H, methyl, ethyl, propyl, isopropyl or 3-heptyl, or cyclohexyl.

[0939] In a preferred embodiment of the present application, in the compounds of the Formula H,

[0940] 15 denotes a group selected from the group of the formulae:

[0941] 20

[0942] 35 Foreignfiling text P24-166-SEC-WO01

[0943] In a further preferred embodiment of the present application, in the compounds of the Formula H,

[0944] 5 denotes a group selected from the group of the formulae

[0945] In yet a further preferred embodiment of the present invention, in the compounds of the Formula H in which p preferably denotes 1 ,

[0946] 25 particularly preferably -O-S^-O- or -S^-O-.

[0947] In a further preferred embodiment of the present invention, in the compounds of the Formula H, the group

[0948] 35 Foreignfiling text P24-166-SEC-WO01

[0949] 179

[0950] 5 denotes a group selected from the group of the formulae

[0951] 15 5 Foreignfiling text P24-166-SEC-WO01

[0952] 180

[0953] In a further preferred embodiment of the present invention, in which p is 2, which may be identical to or different from those described above, in the compounds of the Formula H,

[0954] 5 denotes a group selected from the group of the formulae and

[0955] 35 Foreignfiling text P24-166-SEC-WO01

[0956] 181

[0957] In yet a further preferred embodiment of the present invention, which may be identical to or different from those described above, in the compounds of the Formula H, the group on each occurrence, independently of one another, denotes

[0958] 25 Compounds of the following general Formulae H-1-1 , H-1-2 and H-1-3, showed to be particularly efficient UV stabilisers in LC mixtures, in particular, in terms of VHR stability:

[0959] 35 Foreignfiling text P24-166-SEC-WO01

[0960] 182

[0961] 5 wherein ZG, F ® and n are as defined above and n denotes an integer from 1 to 8. These compounds are highly suitable as stabilisers in LC mixtures and stabilise the VHR of the mixtures upon UV exposure.

[0962] In a particularly preferred embodiment, the one or more compounds of the Formula H may be selected from the group consisting of the compounds the following Formulae H-2-1 to H-2-6:

[0963] 35 Foreignfiling text P24-166-SEC-WO01

[0964] 35 Foreignfiling text P24-166-SEC-WO01

[0965] 184 in which

[0966] R11 each, independently of one another, denotes an H atom, an alkyl group having 1 to 20 C atoms, in which one -CH2- group or, if

[0967] 15 present, a plurality of -CH2- groups may be substituted by -O- or -C(=O)-, but two adjacent -CH2- groups cannot be substituted by -O-, and one or, if present, a plurality of -CH2- groups may be substituted by-CH=CH- or -C=C-, and in which one H atom or a plurality of H atoms may be substituted by F, OR

[0968] 20 R15,

[0969] R16 denotes a H atom or 0‘,

[0970] 25 n denotes an integer from 0 to 12, and each, independently of one another, denote an alkylene group having 1 to 20 C atoms, in which one -CH2- group or, if present, a plurality of -CH2- groups may be substituted by -O- or -C(=O)-, but two adjacent -CH2- groups cannot be substituted by -O-, and in which one H atom or a plurality of H atoms may be substituted by F, or R15 or denote a single bond.

[0971] 35 Foreignfiling_text P24-166-SEC-WO01

[0972] 185

[0973] In a preferred embodiment of the present invention, the LC media comprise in each case one or more compounds of the Formula H selected from the following group of the compounds of the formulae: Foreignfiling_text P24-166-SEC-WO01

[0974] 186

[0975] 30 Foreignfiling_text P24-166-SEC-WO01

[0976] 187 Foreignfiling text P24-166-SEC-WO01

[0977] 188

[0978] 35 Foreignfiling text P24-166-SEC-WO01

[0979] 35 Foreignfiling text P24-166-SEC-WO01

[0980] 190

[0981] 15

[0982] 35 Foreignfiling_text P24-166-SEC-WO01

[0983] 191 Foreignfiling text P24-166-SEC-WO01

[0984] 192

[0985] 25

[0986] 35 Foreignfiling text P24-166-SEC-WO01

[0987] 193

[0988] Preferred content of the one or more compounds of Formula H in the LC medium depends inter alia on the inherent chemical stability of the LC medium as well as on the nature of the compound of Formula H. Compounds of Formula H in which R16

[0989] 25 denotes O, which are known as NO radical type HALS are preferably used in proportion ranging from 50 ppm to 1000 ppm, based on the weight of the LC medium. Compounds of Formula H in which R^® denotes a H atom, which are known as NH radical type HALS are advantageously used in proportion ranging from 50 ppm to 2000 ppm, based on the weight of the LC medium.

[0990] Further preferred LC media are selected from the following preferred embodiments, including any combination thereof:

[0991] • a compound of Formula S in combination with a compound of Formula P, Z1 ,

[0992] 35 Z3 and III; Foreignfiling text P24-166-SEC-WO01

[0993] 194

[0994] • a compound of Formula S in combination with a compound of Formula II and / or III and a compound of Formula selected from the Formulae YA-9, YA- 10, YA-33, YA-34, YA-35, YA-36, YA-42, YA-43, YB-1 , YB-2, YB-3;

[0995] • a compound of Formula S in combination with a compound of the Formula P,

[0996] 5 Z1 , Z4, III and XVII;

[0997] • a compound of Formula S in combination with a compound of the Formula P,

[0998] Z1 , Z4, III and XII;

[0999] • a compound of Formula S in combination with a compound of the Formula P,

[1000] Z1 , Z7, III and XV;

[1001] • a compound of Formula S in combination with a compound of the Formula P,

[1002] Z1 , Z7, III and XXIII;

[1003] • a compound of Formula S in combination with a compound of the Formula P,

[1004] Z1 , LP1 and / or LP2;

[1005] • a compound of Formula S in combination with a compound of the Formula P,

[1006] 15

[1007] Z1 , Z3, Z4 and III;

[1008] • a compound of the Formula S in combination with compounds of the Formula

[1009] B1 and / or B3, Z1 and III;

[1010] • a compound of the Formula S in combination with compounds of the Formula

[1011] B1 and / or B3, one or more of YA to YE, and III;

[1012] 20

[1013] • a compound of the Formula S in combination with compounds of the Formula

[1014] B1 and / or B3, Z1 , Z3 and III

[1015] • a compound of the Formula S in combination with compounds of the Formula

[1016] B1-2, B3-2 and / or, Z1 , Z4 and III

[1017] • a compound of the Formula S in combination with compounds of the Formula

[1018] 25

[1019] B1 and / or B3, XVI and III

[1020] • a compound of the Formula S in combination with compounds of the Formula

[1021] B1 and / or B3, XIV and III

[1022] • a compound of the Formula S in combination with compounds of the Formula

[1023] B1 and / or B3, XXIIIa and III

[1024] • a compound of the Formula S in combination with compounds of the Formula

[1025] B1 and / or B3, XVII and III

[1026] • a compound of the Formula S in combination with compounds of the Formula

[1027] B1 and / or B3, Z1 and III

[1028] 35 Foreignfiling text P24-166-SEC-WO01

[1029] 195

[1030] • a compound of the Formula S in combination with compounds of the Formula

[1031] Z1-1 , Z4-2 and / or Z4-3

[1032] • a compound of the Formula S in combination with compounds of the Formula

[1033] 111-16, 111-1 , HI-6 and / or HI-20

[1034] 5 • a compound of the Formula S in combination with compounds of the Formula

[1035] HI-20 and XXXa

[1036] • a compound of the Formula S in combination with compounds of the Formula

[1037] LP1-1 and LP2-2

[1038] • a compound of the Formula S in combination with at least two compounds of

[1039] 10 the Formula XVI

[1040] • a compound of the Formula S in combination with at least two compounds of the Formula XVHb or at least two compounds of the Formula XVIIe

[1041] • a compound of the Formula S in combination with compounds of the Formula

[1042] HI-16 and H-2

[1043] 15

[1044] • a compound of the Formula S in combination with compounds of the Formula

[1045] XXI I la and H-2

[1046] • a compound of the Formula S in combination with compounds of the Formula

[1047] XI e, XIVd-1 and Z5

[1048] • a compound of the Formulae S and P in combination with a compound of the

[1049] 20

[1050] Formula LP2, any one of Z1 to Z11 and HI

[1051] • a compound of the Formulae S and P in combination with a compound of the

[1052] Formula LP1 , LP2, HI and a compound of the Formula Z1 and Z4

[1053] - The LC medium comprises one or more compounds of the Formula S or its subformulae, III and one or more compounds selected from the group consisting

[1054] 25 of the Formulae Z1 , Z2, Z3, Z4, Z5, V, VI, VII, VIII, XIV, XV, XVI, XVHa, XVHb, XVHc, XVIII, XIX, XX, XXI, XXIII, XXIV, XXV, XXVI, XXVII, XXVIII, XXIX, XXX, XXX-1 , XXX-2, XXX-3, XXXII, XXXIII and their subformulae.

[1055] - The LC medium comprises one or more compounds of the Formula S or its subformulae and B1 and / or B3, HI and one or more compounds selected from the

[1056] 30 group consisting of the Formulae Z1 , Z2, Z3, Z4, Z5, IV, VI, XII, XIV, XVI, XVHa, XVHb, XVHc, XX, LP1-1 , XXIII, XXIX and their subformulae.

[1057] - The LC medium comprises one or more compounds selected from the group consisting of the Formula IH-1 , HI-4, IH-6, HI-16, HI-19 and HI-20, very preferably from the group consisting of the Formula HI-1 , HI-6, HI-16 and HI-20. The

[1058] 35 individual concentration of each of these compounds is preferably from 2 to 15% Foreignfiling text P24-166-SEC-WO01

[1059] 196 by weight. The total concentration of these compounds is preferably from 5 to 30% by weight.

[1060] - The LC medium comprises one or more compounds of the Formula IV, preferably selected from the Formula IVa or IVc, very preferably from the Formula IVa-1 or

[1061] 5 IVc-1 , most preferably of the Formula I c-1. The individual concentration of each of these compounds is preferably from 2 to 15% by weight. The total concentration of these compounds is preferably from 5 to 20% by weight.

[1062] - The LC medium comprises one or more compounds of the Formula VI, preferably selected from the Formula Vlb. The individual concentration of each of these compounds is preferably from 1 to 20% by weight. The total concentration of these compounds is preferably from 5 to 20% by weight.

[1063] - The LC medium comprises one or more compounds of the Formula Z1 , preferably selected from the Formula Z1-1. The total concentration of these compounds is preferably from 10 to 70 % by weight, more preferably 20 to 60 %

[1064] 15 by weight, even more preferably 30 to 50 % by weight.

[1065] - The LC medium comprises one or more compounds of the Formula Z2, preferably selected from the Formulae Z2-1 and Z2-2. The total concentration of these compounds is preferably from 2 to 35%, very preferably from 3 to 25% by weight.

[1066] 20 - The LC medium comprises from 5 to 20% by weight of compounds of the Formula Z3, preferably of the Formula Z3-1.

[1067] - The LC medium comprises from 5 to 20% by weight of compounds of the Formula Z4, preferably of the Formula Z4-1.

[1068] - The LC medium comprises from 1 to 30%, very preferably from 2 to 15% by

[1069] 25 weight of compounds of Formula Z5.

[1070] - The LC medium comprises one or more compounds of the Formula LP1-1 , preferably of the Formula LP1-1a or LP2-1b, very preferably of the Formula LP1- 1a. The concentration of these compounds is preferably from 1 to 15% by weight.

[1071] - The LC medium comprises from 1 to 15% by weight of compounds of the Formula LP2-1b.

[1072] - The LC medium comprises one or more compounds of the Formula XII, preferably of the Formula XI 1-1 a or XI 1-1 b, very preferably of the Formula XI 1-1 a, most preferably of the Formula Xll-1a-1. The concentration of these compounds is preferably from 2 to 15% by weight.

[1073] 35 Foreignfiling text P24-166-SEC-WO01

[1074] 197

[1075] - The LC medium comprises from 1 to 15% by weight of compounds of the Formula Xll-1b.

[1076] - The LC medium comprises one or more compounds of the Formula XIV, preferably of the Formula Xl d, very preferably of the Formula XI d-1. The

[1077] 5 concentration of these compounds is preferably from 2 to 10% by weight.

[1078] - The LC medium comprises one or more compounds of the Formula XVIb, preferably of the Formula XVIb-1, XVIb-2 and / or XVIb-3. The concentration of these compounds is preferably from 2 to 15% by weight.

[1079] - The LC medium comprises one or more compounds of the Formula XVIc, preferably of the Formula XVIc-1, XVIc-2 and / or XVIc-3. The concentration of these compounds is preferably from 2 to 20% by weight.

[1080] - The LC medium comprises one or more compounds selected from the group consisting of the Formulae XVIIa, XVIIb and XVIIc, very preferably of the Formula XVIIa wherein L is H and of the Formula XVIIb wherein L is F. The total

[1081] 15 concentration of these compounds is preferably from 0.5 to 5% by weight.

[1082] - The LC medium comprises one or more compounds of the Formula XX, preferably of the Formula XXa. The concentration of these compounds is preferably from 2 to 10% by weight.

[1083] - The LC medium comprises one or more compounds of the Formula XXI,

[1084] 20 preferably of the Formula XXIa. The concentration of these compounds is preferably from 2 to 10% by weight.

[1085] - The LC medium comprises one or more compounds of the Formula XXIII, preferably of the Formula XXIIIa. The concentration of these compounds is preferably from 0.5 to 5% by weight.

[1086] 25 - The LC medium comprises one or more compounds of the Formula XXIX, preferably of the Formula XXIXa. The concentration of these compounds is preferably from 2 to 10% by weight.

[1087] - The LC medium comprises one or more compounds of the Formula XXX. The concentration of these compounds is preferably from 2 to 10% by weight.

[1088] - The LC medium comprises one or more compounds of the Formula XII. The concentration of these compounds is preferably from 2 to 10% by weight.

[1089] - The LC medium comprises one or more compounds of the Formula S, one or more compounds selected from the group consisting of the Formulae Z1, Z2 and Z4 or their subformulae, one or more compounds selected from the group consisting of

[1090] 35 the Formula XIV, one or more compounds selected from the group consisting of Foreignfiling text P24-166-SEC-WO01

[1091] 198 the Formulae IV, VI, XX, XXIII and XXIX or their subformulae, and one or more compounds selected from the group consisting of the Formulae, XVI, XVIIa, XVIIb, XVI Ic or their subformulae.

[1092] - The LC medium comprises one or more compounds of Formula S, preferably of

[1093] 5 the Formula S-5, III, one or more compounds selected from the group consisting of the Formulae Z1 , Z2, Z3, Z4 and Z5 or their subformulae, one or more compounds selected from the group consisting of the Formula XlVd or their subformulae, one or more compounds selected from the group consisting of the Formulae IVc, Vlb, XXa, XXI I la and XXIXa or their subformulae, and one or more compounds selected from the group consisting of the Formulae LP1-1b, XVIb, XVIc, XVIIa, XVIIb, XVIIc or their subformulae.

[1094] - The LC medium comprises one or more compounds of the Formula S, preferably of the Formula S-5, III, one or more compounds selected from the group consisting of the Formulae Z1 , Z2 and Z3 or their subformulae, one or more compounds of

[1095] 15 the Formula YA to YE, preferably selected from the group consisting of the Formulae YA and YB, one or more compounds selected from the group consisting of the Formula XIV, one or more compounds selected from the group consisting of the Formulae III, IV, VI, XX, XXIII and XXIX or their subformulae, and one or more compounds selected from the group consisting of the Formulae LP2-1 , XVI, XVIIa,

[1096] 20 XVIIb, XVIIc or their subformulae.

[1097] - The LC medium comprises one or more compounds of the Formula S, preferably of the Formula S-5-3, one or more compounds selected from the group consisting of the Formulae Z1 , Z2, Z3, Z4 and Z5 or their subformulae, one or more compounds of Formula B, preferably selected from the group consisting of the

[1098] 25 Formulae B1 , B2 and B3, one or more compounds of the Formula XlVd or their subformulae, one or more compounds selected from the group consisting of the Formulae III, IVc, Vlb, XXa, XXIIIa and XXIXa or their subformulae, and one or more compounds selected from the group consisting of the Formulae LP1-1b, XVIb, XVIc, XVIIa, XVIIb, XVIIc or their subformulae.

[1099] - Besides the compounds of the Formula S, P Oder B , the LC medium comprises further compounds selected from the group of the compounds of the Formula Z1 , Z2, Z3, IV, LP1-1 , XIV, XVI, XVIIa, XVIIb, XVIIc, XXI, XXIII, XXIX, XXX and XXIV or their subformulae.

[1100] - Besides the compounds of the Formulae S, B1 and / or B3, the LC medium com¬

[1101] 35 prises further compounds selected from the group of the compounds of the Foreignfiling text P24-166-SEC-WO01

[1102] 199

[1103] Formulae Z1, Z2, Z3, IV, LP2-1 , XIV, XVI, XVIIa, XVIIb, XVIIc, XXI, XXIII, XXIX, XXX and XXIV or their subformulae.

[1104] - The proportion of compounds of the Formula S or its subformulae in the LC medium is from 0,5 to 40%, very preferably from 1 to 30%, most preferably from

[1105] 5 1.5 to 20% by weight.

[1106] - The proportion of compounds of the Formulae Z1 , Z2, Z3, Z4 and Z5 or their subformulae in the LC medium as a whole is from 10 to 65%, very preferably from 20 to 60% by weight.

[1107] - The proportion of compounds of the Formula YA to YF or their subformulae in the LC medium as a whole is from 0 to 15%, very preferably from 2 to 10% by weight.

[1108] - The proportion of compounds of the Formula B or its subformulae in the LC medium as a whole is from 0 to 15%, very preferably from 2 to 10% by weight.

[1109] - The proportion of compounds of the Formulae III, IV-VIII, XVIII-XXIII and XXVII-

[1110] 15 XXX in the LC medium as a whole is 5 to 60% by weight, more preferred is 10 to 30% by weight.

[1111] - The proportion of compounds of the Formulae XIV and XV in the LC medium as a whole is 1 to 20% by weight.

[1112] - The proportion of compounds of the Formulae XIV, XVIIa-c and XXXII in the LC

[1113] 20 medium as a whole is 0.5 to 15% by weight.

[1114] The term "alkyl" or "alkyl*" in this application encompasses straight-chain and branched alkyl groups having 1 to 6 carbon atoms, in particular the straight-chain groups methyl, ethyl, propyl, butyl, pentyl and hexyl. Groups having 2 to 5 carbon

[1115] 25 atoms are generally preferred.

[1116] The term "alkenyl" or “alkenyl*" encompasses straight-chain and branched alkenyl groups having 2 to 6 carbon atoms, in particular the straight-chain groups. Preferred alkenyl groups are C2-Cy-1E-alkenyl, C^Cg-SE-alkenyl, in particular C2-C5-IE- alkenyl. Examples of particularly preferred alkenyl groups are vinyl, 1 E-propenyl, 1 E-butenyl, 1E-pentenyl, 1E-hexenyl, 3-butenyl, 3E-pentenyl, 3E-hexenyl, 4-pentenyl, 4Z-hexenyl, 4E-hexenyl and 5-hexenyl. Groups having up to 5 carbon atoms are generally preferred, in particular CH2=CH, CH3CH=CH.

[1117] 35 Foreignfiling text P24-166-SEC-WO01

[1118] 200

[1119] The term "fluoroalkyl" preferably encompasses straight-chain groups having a terminal fluorine, i.e. fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl and 7-fluoroheptyl. However, other positions of the fluorine are not excluded.

[1120] 5

[1121] The term "oxaalkyl" or "alkoxy" preferably encompasses straight-chain groups of the Formula CnH2n+i-O-(CH2)m, in which n and m each, independently of one another, denote 1 to 6. m may also denote 0. Preferably, n = 1 and m = 1 to 6 or m = 0 and n = 1 to 3. Further preferably the alkoxy or oxaalkyl group can also contain one or more further O atoms such that oxygen atoms are not directly linked to one another.

[1122] Through a suitable choice of the meanings in Formulae II and III, the addressing times, the threshold voltage, the steepness of the transmission

[1123] 15 characteristic lines, etc., can be modified in the desired manner. For example, 1E- alkenyl groups, 3E-alkenyl groups, 2E-alkenyloxy groups and the like generally result in shorter addressing times, improved nematic tendencies and a higher ratio between the elastic constants K3 (bend) and (splay) compared with alkyl and alkoxy groups. 4-Alkenyl groups, 3-alkenyl groups and the like generally give lower

[1124] 20 threshold voltages and lower values of K3 / compared with alkyl and alkoxy groups. The LC media according to the invention are distinguished, in particular, by high As values and thus have significantly faster response times than the LC media from the prior art.

[1125] 25

[1126] The optimum mixing ratio of the compounds of the above-mentioned formulae depends substantially on the desired properties, on the choice of the components of the above-mentioned formulae and on the choice of any further components that may be present.

[1127] Suitable mixing ratios within the range indicated above can easily be determined from case to case.

[1128] The total amount of compounds of the above-mentioned formulae in the LC media

[1129] 35 according to the invention is not crucial. The LC media can therefore comprise one Foreignfiling text P24-166-SEC-WO01

[1130] 201 or more further components for the purposes of optimisation of various properties. However, the observed effect on the desired improvement in the properties of the medium is generally greater, the higher the total concentration of compounds of the above-mentioned formulae.

[1131] 5

[1132] In a particularly preferred embodiment, the LC media according to the invention comprise compounds of the Formulae III to VIII (preferably IV and V) in which denotes F, CF3CHF2OCHF2or OCF3, OCHF2, OCH=CF2, OCF=CF2or OCF2-CF2H. A favourable synergistic action with the compounds of the Formulae S and P or S and B results in particularly advantageous properties. In particular, LC media comprising compounds of the Formulae S and P, III as well as of the Formulae S and B, III are distinguished by their low threshold voltage.

[1133] The individual compounds of the above-mentioned formulae and the subformulae

[1134] 15 thereof which can be used in the LC media according to the invention are either known or can be prepared analogously to the known compounds.

[1135] The invention also relates to a process for the preparation of a LC medium as described above and below, by mixing one or more compounds of Formula S and

[1136] 20 one or more compounds selected from the group consisting of the Formulae III, Z1, Z2, Z3, Z4, IV, VI, XIV, XVI, XVIIa, XVIIb, XVIIc, XX, XXIII, XXIX.

[1137] The LC medium of the present invention may optionally comprise one or more polymerisable compounds. The polymerisable compounds are preferably selected

[1138] 25 from the Formula M

[1139] Ra-Bl-(Zb-B2)m-Rb M in which the individual substituents, on each occurrence identically or differently, and each, independently of one another, have the following meaning:

[1140] Raand RbP, P-Sp-, H, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, SF5or straight-chain or branched alkyl having 1 to 25 C atoms, in which,

[1141] 35 in addition, one or more non-adjacent CH2groups may each be Foreignfiling text P24-166-SEC-WO01

[1142] 202 replaced, independently of one another, by -C(R0)=C(R00)-, -C=C-, -N(R00)-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and / or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by F, Cl, Br,

[1143] 5 I, CN, P or P-Sp-, where, if B^ and / or B^ contain a saturated C atom, Raand / or Rb may also denote a group which is spiro-linked to this saturated C atom, wherein at least one of the substituents Raand Rb denotes or contains a group P or P-Sp-,

[1144] P a polymerisable group,

[1145] Sp a spacer group or a single bond,

[1146] 15 B^ and B^ an aromatic, heteroaromatic, alicyclic or heterocyclic group, preferably having 4 to 25 ring atoms, which may also contain fused rings, and which is unsubstituted, or mono- or polysubstituted by L,

[1147] Zb-O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH2-, -CH2O-, -SCH2-,

[1148] 20

[1149] -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -(CH2)n1-, -CF2CH2-, -CH2CF2-, -(CF2)n1-, -CH=CH-, -CF=CF-, -C=C-, -CH=CH-COO-, single bond,

[1150] 25 RO and R^O each, independently of one another, denote H or alkyl having 1 to 12 C atoms, m denotes 0, 1 , 2, 3 or 4, n1 denotes 1 , 2, 3 or 4,

[1151] L P, P-Sp-, OH, CH2OH, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS,

[1152] -OCN, -SCN, -C(=O)N(RX)2, -C(=O)Y1, -C(=O)RX, -N(RX)2, optionally substituted silyl, optionally substituted aryl having 6 to 20 C atoms, or straight-chain or branched alkyl, alkoxy, alkylcarbonyl,

[1153] 35 Foreignfiling text P24-166-SEC-WO01

[1154] 203 alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 C atoms, in which, in addition, one or more H atoms may be replaced by F, Cl, P or P-Sp-,

[1155] 5 P and Sp have the meanings indicated in the Formula M above, denotes halogen,

[1156] Rxdenotes P, P-Sp-, H, halogen, straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, in which, in addition, one or more non- adjacent CH2 groups may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and / or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by F, Cl, P or P-Sp-, an optionally substituted aryl or aryloxy group having 6 to 40 C atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 40 C atoms.

[1157] 15

[1158] Further preferably, the LC media according to the present invention comprise one or more polymerisable compounds selected from Table H below.

[1159] Preferably, the proportion of polymerisable compounds in the LC medium,

[1160] 20 preferably selected from the Formula M and Table H, is from 0.01 to 5%, very preferably from 0.05 to 1%, most preferably from 0.1 to 0.5%.

[1161] It was observed that the addition of one or more polymerisable compounds to the LC medium, like those selected from the Formula M and Table H, leads to

[1162] 25 advantageous properties like fast response times. Such a LC medium is especially suitable for use in PSA displays where it shows low image sticking, a quick and complete polymerisation, the quick generation of a low pretilt angle which is stable after UV exposure, a high reliability, high VHR value after UV exposure, and a high birefringence. By appropriate selection of the polymerisable compounds it is possible to increase the absorption of the LC medium at longer UV wavelengths, so that it is possible to use such longer UV wavelengths for polymerisation, which is advantageous for the display manufacturing process.

[1163] 35 Foreignfiling text P24-166-SEC-WO01

[1164] 204

[1165] Preference is generally given to LC media which have a nematic LC phase, and preferably have no chiral liquid crystal phase.

[1166] The invention also relates to the use of a LC medium according to the present

[1167] 5 invention as described above and below for electro-optical purposes, in particular for the use is in shutter glasses, for 3D applications, in TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, positive VA and positive PS-VA displays, and to electro-optical displays, in particular of the aforementioned types, containing a LC medium according to the present invention as described above and below, in particular a TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, positive VA (vertically aligned) or positive PS-VA display.

[1168] The invention also relates to electro-optical displays, such as, for example, STN or matrix LC (MLC) displays, having two plane-parallel outer plates, which, together

[1169] 15 with a frame, form a cell, integrated non-linear elements for switching individual pixels on the outer plates, and a nematic LC medium having positive dielectric anisotropy and high specific resistance located in the cell, wherein the nematic LC medium is a LC medium according to the present invention as described above and below.

[1170] 20

[1171] The LC media according to the invention enable a significant broadening of the available parameter latitude. The achievable combinations of clearing point, viscosity at low temperature, thermal and UV stability and high optical anisotropy are far superior to previous materials from the prior art.

[1172] 25

[1173] In particular, the combination of compounds of the Formula S with compounds selected from the Formulae I l-XXXI I or their subformulae, leads to LC media which show a high average elastic constant Kavin combination with a low response time and a low rotational viscosity. This enables fast energy saving LC displays, especially of the FFS, HB-FFS, XB-FFS and IPS mode.

[1174] The LC media according to the invention are suitable for mobile applications and TFT applications, such as, for example, mobile telephones and PDAs. Furthermore, the LC media according to the invention are particularly suitably for use in FFS, HB-

[1175] 35 FFS, XB-FFS and IPS displays based on dielectrically positive liquid crystals. Foreignfiling text P24-166-SEC-WO01

[1176] 205

[1177] The LC media according to the present invention, while retaining the nematic phase down to -20 °C and preferably down to -30 °C, particularly preferably down to -40 °C, and the clearing point > 80 °C, preferably > 90 °C, more preferably

[1178] 5 > 100 °C. They preferably allow rotational viscosities yj of < 120 mPa • s, particularly preferably < 100 mPa • s, to be achieved, enabling excellent MLC displays having fast response times to be achieved. The rotational viscosities are determined at 20 °C.

[1179] The dielectric anisotropy As of the LC media according to the invention at 20 °C and 1 kHz is preferably > +1.5, very preferably from +3 to +18, most preferred from +5 to +15.

[1180] The birefringence An of the LC media according to the invention at 20 °C is preferably

[1181] 15 from 0.08 to 0.2, very preferably from 0.09 to 0.15.

[1182] The rotational viscosity yj of the LC media according to the invention is preferably

[1183] < 120 mPa ■ s, more preferably < 110 mPa ■ s, very preferably < 90 mPa ■ s.

[1184] 20

[1185] The ratio yj / Kj (wherein yj is the rotational viscosity and Kj is the elastic constant for splay deformation) of the LC media according to the invention is preferably

[1186] < 7.0 mPa ■ s / pN, very preferably < 5.0 mPa s / pN, most preferably < 4.0 mPa s / pN.

[1187] 25 The average elasticity constant ratio Kavof the LC media according to the invention is preferably at least 14.0 pN, very preferably at least 14.0 pN, most preferably at least 15.0 pN. Kavcan be calculated according to the following formula: Kav= (K^ + K2+ K3) / 3 « (K | +1 / 2* K | + K3) / 3.

[1188] The nematic phase range of the LC media according to the invention preferably has a width of at least 90 °C, more preferably of at least 100 °C, in particular at least 110 °C. This range preferably extends at least from -25 °C to +90 °C.

[1189] 35 Foreignfiling text P24-166-SEC-WO01

[1190] 206

[1191] It goes without saying that, through a suitable choice of the components of the LC media according to the invention, it is also possible for higher clearing points (for example above 100 °C) to be achieved at higher threshold voltages or lower clearing points to be achieved at lower threshold voltages with retention of the other

[1192] 5 advantageous properties. At viscosities correspondingly increased only slightly, it is likewise possible to obtain LC media having a higher As and thus low thresholds. The MLC displays according to the invention preferably operate at the first Gooch and Tarry transmission minimum [C.H. Gooch and H.A. Tarry, Electron. Lett. 10, 2-4, 1974; C.H. Gooch and H.A. Tarry, Appl. Phys., Vol. 8, 1575-1584, 1975], where, besides particularly favourable electro-optical properties, such as, for example, high steepness of the characteristic line and low angle dependence of the contrast (German patent 3022 818), lower dielectric anisotropy is sufficient at the same threshold voltage as in an analogous display at the second minimum. This enables significantly higher specific resistance values to be achieved using the LC

[1193] 15 media according to the invention at the first minimum than in the case of LC media comprising cyano compounds. Through a suitable choice of the individual components and their proportions by weight, the person skilled in the art is able to set the birefringence necessary for a pre-specified layer thickness of the MLC display using simple routine methods.

[1194] 20

[1195] Measurements of the voltage holding ratio (VHR) [S. Matsumoto et al., Liquid Crystals 5, 1320 (1989); K. Niwa et al., Proc. SID Conference, San Francisco, June 1984, p. 304 (1984); G. Weber et al., Liquid Crystals 5, 1381 (1989)] have shown that LC media according to the invention exhibit a significantly smaller decrease in

[1196] 25 the VHR on UV exposure than analogous LC media comprising cyano- phenylcyclohexanes of the Formula or esters of the Formula

[1197] The light stability and UV stability of the LC media according to the invention are considerably better, i.e. they exhibit a significantly smaller decrease in the HR on

[1198] 35 exposure to light, heat or UV. Foreignfiling text P24-166-SEC-WO01

[1199] 207

[1200] The construction of the MLC display according to the invention from polarisers, electrode base plates and surface-treated electrodes corresponds to the usual design for displays of this type. The term usual design is broadly drawn here and

[1201] 5 also encompasses all derivatives and modifications of the MLC display, in particular including matrix display elements based on poly-Si TFTs or MIM.

[1202] A significant difference between the displays according to the invention and the hitherto conventional displays based on the twisted nematic cell consists, however, in the choice of the LC parameters of the LC layer.

[1203] The LC media which can be used in accordance with the invention are prepared in a manner conventional perse, for example by mixing compounds of Claim 1 with one or more compounds of the Formulae I l-XXXI I or with further LC compounds and / or

[1204] 15 additives. In general, the desired amount of the components used in lesser amount is dissolved in the components making up the principal constituent, advantageously at elevated temperature. It is also possible to mix solutions of the components in an organic solvent, for example in acetone, chloroform or methanol, and to remove the solvent again, for example by distillation, after thorough mixing.

[1205] 20

[1206] The LC media may also comprise further additives known to the person skilled in the art and described in the literature, such as, for example, polymerisation initiators, inhibitors, surface-active substances, microparticles, free-radical scavengers, nanoparticles, etc. For example, 0 to 15% of pleochroic dyes or chiral dopants or

[1207] 25 initiators like Irgacure® 651 or Irgacure® 907 can be added. Suitable stabilisers and dopants are mentioned below in Tables F and G. In a preferred embodiment, the LC medium comprises one or more stabilisers selected from Table G. Preferably, the proportion of antioxidants and light stabilisers, like those of the Formula ST and H, as described above or listed in Table G, in the LC medium is from 10 to 2000 ppm, very preferably from 30 to 1000 ppm.

[1208] Furthermore, it is possible to add to the LC media, for example, 0 to 15% by weight of pleochroic dyes, furthermore nanoparticles, conductive salts, preferably ethyldimethyldodecylammonium 4-hexoxybenzoate, tetrabutylammonium

[1209] 35 tetraphenylborate or complex salts of crown ethers {cf., for example, Haller et al., Foreignfiling text P24-166-SEC-WO01

[1210] 208

[1211] Mol. Cryst. Liq. Cryst. 24, 249-258 (1973)), for improving the conductivity, or substances for modifying the dielectric anisotropy, the viscosity and / or the alignment of the nematic phases. Substances of this type are described, for example, in DE-A 22 09 127, 22 40 864, 2321 632, 23 38281, 24 50 088, 26 37430 and 28 53 728.

[1212] 5

[1213] For the present invention and in the following examples, the structures of the LC compounds are indicated by means of acronyms, with the transformation into chemical formulae taking place in accordance with Tables A to C below. All substituents CmH2m+i , CnH2n+i , and C|H2|+1orCmH2m-1’ CnH2n-1 and C|H2|-1 are straight-chain alkyl groups or alkylene groups, in each case having n, m and I C atoms respectively. Preferably, n, m and I are independently of each other 1, 2, 3, 4, 5, 6, or 7. Table A shows the codes for the ring elements of the nuclei of the compound, Table B lists the bridging units, and Table C lists the meanings of the symbols for the left- and right-hand end groups of the molecules. The acronyms are

[1214] 15 composed of the codes for the ring elements with optional linking groups, followed by a first hyphen and the codes for the left-hand end group, and a second hyphen and the codes for the right-hand end group. Table D shows illustrative structures of compounds together with their respective abbreviations.

[1215] 20

[1216] Table A: Ring elements

[1217] 35 Foreignfiling text P24-166-SEC-WO01

[1218] 209

[1219] 35 Foreignfiling text P24-166-SEC-WO01

[1220] 210 Foreignfiling text P24-166-SEC-WO01

[1221] 211

[1222] Table C: End

[1223] On the left individually or in combiOn the right individually or in comnation bination

[1224] 35 Foreignfiling text P24-166-SEC-WO01

[1225] 212

[1226] 35 Foreignfiling text P24-166-SEC-WO01

[1227] 213

[1228] On the left only in combination On the right only in combination

[1229] -...n...- -CnH2n- -...n... -CnH2n-

[1230] -...M...- -CFH- -...M... -CFH-

[1231] 5

[1232] -...D...- -CF2- -...D... -CF2-

[1233] -...V...- -CH=CH- -...V... -CH=CH-

[1234] -...Z...- -CO-O- -...Z... -CO-O-

[1235] -...Zl...- -O-CO- -...Zl... -O-CO-

[1236] -...K...- -CO- -...K... -CO-

[1237] -...W...- -CF=CF- -...W... -CF=CF- in which n and m are each integers, and the three dots are placeholders for

[1238] 15 other abbreviations from this table.

[1239] The following abbreviations are used:

[1240] (n, m, k and I are, independently of one another, each an integer, preferably 1 to 12 preferably 1 to 6, k and I possibly may be also 0 and preferably are 0 to 4, more

[1241] 20 preferably 0 or 2 and most preferably 2, n preferably is 1 , 2, 3, 4 or 5, in the combination “-nO-” it preferably is 1 , 2, 3 or 4, preferably 2 or 4, m preferably is 1 , 2,

[1242] 3, 4 or 5, in the combination “-Om” it preferably is 1 , 2, 3 or 4, more preferably 2 or

[1243] 4. The combination “-IVm” preferably is “2V1”.)

[1244] Preferred components of the LC medium are shown in Tables D and E.

[1245] 25

[1246] Table D Foreignfiling text P24-166-SEC-WO01

[1247] 214

[1248] MEnF.F MEnm

[1249] 20

[1250] 35 Foreignfiling text P24-166-SEC-WO01

[1251] 215

[1252] 20

[1253] 35 Foreignfiling text P24-166-SEC-WO01

[1254] 216

[1255] CFU

[1256] 20

[1257] Table E

[1258] In the following formulae, n and m each, independently of one another, denote 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, in particular 2, 3, 5, furthermore 0, 4, 6.

[1259] 35 Foreignfiling text P24-166-SEC-WO01

[1260] 217

[1261] 35 Foreignfiling text P24-166-SEC-WO01

[1262] 218 Foreignfiling text P24-166-SEC-WO01

[1263] 219

[1264] 20

[1265] CPPC-nV-Vm

[1266] 35 Foreignfiling text P24-166-SEC-WO01

[1267] 35 Foreignfiling text P24-166-SEC-WO01

[1268] 221

[1269] 35 Foreignfiling text P24-166-SEC-WO01

[1270] 222 Foreignfiling text P24-166-SEC-WO01

[1271] 223 Foreignfiling text P24-166-SEC-WO01

[1272] 224

[1273] PGUQU-(c5)-F

[1274] 20

[1275] 35 Foreignfilingjext P24-166-SEC-WO01

[1276] 225 Foreignfiling text P24-166-SEC-WO01

[1277] 25

[1278] 35 Foreignfiling text P24-166-SEC-WO01

[1279] 227

[1280] PYP-n-m

[1281] 15 Particular preference is given to LC media which, besides the compounds of the Formula S, comprise at least one, two, three, four or more compounds from Table E.

[1282] Table F

[1283] 20 Table F indicates possible dopants which are generally added to the LC media according to the invention. The LC media preferably comprise 0-10% by weight, in particular 0.01-5% by weight and particularly preferably 0.01-3% by weight of dopants.

[1284] CM 21 R / S-811

[1285] 35 Foreignfiling text P24-166-SEC-WO01

[1286] 228

[1287] Table G

[1288] Antioxidants and light stabilizers, which can additionally be added, for example, to the LC media according to the invention in amounts of 0 to 10% by weight, are mentioned below.

[1289] 35 Foreignfiling text P24-166-SEC-WO01

[1290] 229 n = 1, 2, 3, 4, 5, 6 or 7 n = 1, 2, 3, 4, 5, 6 or 7 q= 1, 2, 3, 4, 5, 6 or 7

[1291] 25

[1292] 35 Foreignfiling_text P24-166-SEC-WO01 Foreignfiling_text P24-166-SEC-WO01

[1293] 231 Foreignfiling text P24-166-SEC-WO01

[1294] 232

[1295] 5

[1296] 20

[1297] 25

[1298] 30

[1299] 35 Foreignfiling_text P24-166-SEC-WO01 Foreignfiling text P24-166-SEC-WO01

[1300] 234

[1301] 5 q = 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10

[1302] Table H

[1303] Table H shows illustrative reactive mesogenic compounds (RMs) which can be used in the LC media in accordance with the present invention. Foreignfiling text P24-166-SEC-WO01

[1304] 235

[1305] RM-7 RM-8

[1306] 15

[1307] RM-19 RM-20 5 Foreignfiling_text P24-166-SEC-WO01

[1308] 236 Foreignfiling text P24-166-SEC-WO01

[1309] 237

[1310] 35 Foreignfiling_text P24-166-SEC-WO01

[1311] 238 Foreignfiling_text P24-166-SEC-WO01

[1312] 239

[1313] 35 Foreignfiling text P24-166-SEC-WO01

[1314] 240 5 0 Foreignfiling text P24-166-SEC-WO01 Foreignfiling text P24-166-SEC-WO01

[1315] 242 0 5

[1316] RM-100 5 Foreignfiling_text P24-166-SEC-WO01

[1317] 243 Foreignfiling_text P24-166-SEC-WO01 Foreignfiling text P24-166-SEC-WO01

[1318] 15

[1319] 35 Foreignfiling text P24-166-SEC-WO01

[1320] 35 Foreignfiling text P24-166-SEC-WO01

[1321] 25

[1322] 35 Foreignfiling_text P24-166-SEC-WO01 Foreignfiling text P24-166-SEC-WO01

[1323] 35 Foreignfiling_text P24-166-SEC-WO01

[1324] RM-163 RM-164

[1325] 25

[1326] RM-165 RM-166

[1327] 35 Foreignfiling text P24-166-SEC-WO01

[1328] 251

[1329] RM-171 RM-172

[1330] RM-173 RM-174

[1331] 35 Foreignfiling text P24-166-SEC-WO01

[1332] The LC media according to the invention may optionally comprise one or more polymerizable compounds, preferably selected from the polymerizable compounds

[1333] 20 of the Formulae RM-1 to RM-184. Of these, compounds RM-1 , RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41 , RM-48, RM-52, RM-54, RM-57, RM-58, RM-64, RM-74, RM-76, RM-88, RM-91 , RM-102, RM-103, RM-109, RM- 116, RM-117, RM-120, RM-121, RM-122, RM-139, RM-140, RM-142, RM-143, RM- 145, RM-146, RM-147, RM-149, RM-156 to RM-163, RM-169, RM-170 and RM-171

[1334] 25 to RM- 184 are particularly preferred.

[1335] The following examples are intended to explain the invention without limiting it.

[1336] Above and below, percentage data denote per cent by weight. All temperatures are indicated in degrees Celsius, m.p. denotes melting point, cl.p. = clearing point. Furthermore, C = crystalline state, N = nematic phase, S = smectic phase and I = isotropic phase. The data between these symbols represent the transition temperatures. Furthermore, the following symbols are used

[1337] 35 VQ Freedericks threshold voltage, capacitive [V] at 20 °C, Foreignfiling text P24-166-SEC-WO01

[1338] 253

[1339] VIQ voltage [V] for 10% transmission, neextraordinary refractive index measured at 20 °C and 589 nm, ng ordinary refractive index measured at 20 °C and 589 nm,

[1340] An optical anisotropy measured at 20 °C and 589 nm,

[1341] 5 dielectric susceptibility (or "dielectric constant") perpendicular to the to the longitudinal axes of the molecules at 20 °C and 1 kHz, s 1 1 dielectric susceptibility (or "dielectric constant") parallel to the to the longitudinal axes of the molecules at 20 °C and 1 kHz, As dielectric anisotropy at 20 °C and 1 kHz, cl.p. or

[1342] T(N,I) clearing point [°C], v flow viscosity measured at 20 °C [mm^s^],

[1343] 71 rotational viscosity measured at 20 °C [mPa-s],

[1344] 15

[1345] Ki elastic constant, "splay1' deformation at 20 °C [pN],

[1346] K2 elastic constant, "twist' deformation at 20 °C [pN],

[1347] K3 elastic constant, "bend' deformation at 20 °C [pN], and

[1348] VHR voltage holding ratio.

[1349] 20

[1350] All physical properties are determined in accordance with "Merck Liquid Crystals, Physical Properties of Liquid Crystals", status Nov. 1997, Merck KGaA, Germany, and apply for a temperature of 20°C, unless explicitly indicated otherwise.

[1351] 25 Examples

[1352] Synthesis Example 1

[1353] Step 1.1 : 2-Thiophen-3-yl-methyl pentanoic acid

[1354] 35 Foreignfiling text P24-166-SEC-WO01

[1355] 254

[1356] Diisopropylamine (225 g, 1.601 mol) is dissolved in 700 ml THF, 15% solution of n- butyl lithium in hexane (1.0 I, 1.592 mol) is added at -20 °C and stirred for 30 min. Valeric acid (80 ml, 0.735 mol), dissolved in 50 ml THF, is added at -20 °C. 1,3- dimethyltetrahydro-2(1 / - / )-pyrimidinone (100 ml, 0.827 mol) is added to the resulting

[1357] 5 suspension. The mixture is allowed to come to room temperature and stirred for 30 minutes. 3-Bromomethyl thiophene (133 g, 0.726 mol), dissolved in 50 ml THF, is added to this solution at 10 to 15°C and the mixture is stirred overnight at room temperature. 200 ml of water is added under cooling at 5 to 10 °C, followed by 400 ml of 25% HCI, the organic phase is separated and the aqueous phase is extracted with MTBE. The combined organic phases are washed with water, dried over sodium sulphate and concentrated.

[1358] The obtained brown oil is mixed with water, alkalised with 80 ml 32% NaOH and extracted with MTBE. The aqueous phase is acidified with 150 ml 25% HCI and re¬

[1359] 15 extracted with MTBE. The combined extracts are washed with water, dried and concentrated under reduced pressure to deliver 149 g of a brown oil.

[1360] Step 1.2: 5-Propyl-4,5-dihvdro-cvclopentafb1thiophen-6-one

[1361] 20

[1362] 2-Thiophen-3-ylmethyl-pentanoic acid (150.00 g, 0.703 mol) is added at room

[1363] 25 temperature to thionyl chloride (110 ml, 1.516 mol) and heated under reflux overnight. Subsequently, the reaction mixture is cooled to room temperature and the excess of thionyl chloride is removed under reduced pressure (40 mbar). The crude 2-thiophen-3-ylmethyl-pentanoyl chloride is obtained as a brown oil and used directly in the subsequent step.

[1364] Anhydrous aluminium chloride (150.00 g, 1.125 mol) is added at room temperature to 700 ml of dichloromethane and the suspension is cooled to -40 °C. 2-Thiophen-3- ylmethyl-pentanoylchloride (156.83 g, 0.724 mol), dissolved in 300 ml dichloromethane, is added to the mixture. Subsequently, the reaction mixture is

[1365] 35 stirred for 4 h at -40 °C. The mixture is poured onto ice. The organic phase is Foreignfiling text P24-166-SEC-WO01

[1366] 255 removed and the aqueous phase is re-extracted with dichloromethane. The combined organic extracts are diluted with water and washed with sodium bicarbonate solution, dried over sodium sulphate and concentrated under reduced pressure. The obtained dark oil is eluted with dichloromethane over silica.

[1367] 5

[1368] Step 1.3: 5-Propyl-5,6-dihvdro-4H-cvclopenta[b1thiophene

[1369] Anhydrous aluminium chloride (30.40 g, 0.228 mol) is dissolved in portions in 150 ml of diethyl ether at 0-5 °C. Subsequently, lithium aluminium hydride (4.40 g, 0.119 mol) is added in portions at 0-5 °C. 5-propyl-4,5-dihydro-

[1370] 15 cyclopenta[b]thiophen-6-one, dissolved in 100 ml diethyl ether, is added at 5 °C. After the addition is complete, the reaction mixture is stirred for about 1 h at room temperature.

[1371] The mixture is then cooled to 5 °C and carefully added to ice / concentrated HCI upon

[1372] 20 stirring, pentane is added and the phases are separated. The aqueous phase is extracted twice with pentane and the combined organic extracts are washed with water and NaCI solution, dried and concentrated in vacuo. The residue is eluted with pentane over silica to deliver 15.8 g of a clear light brown liquid.

[1373] 25 Step 1.4: building block 2

[1374] 5-Propyl-5,6-dihydro-4H-cyclopenta[b]thiophene (26.90 g, 0.158 mol) is dissolved in THF and cooled to -70 °C. 15% solution of n-butyl lithium (110 ml, 0.175 mol) is added and stirring is continued for 30 min at -75 °C. Subsequently, the mixture is allowed to come to -20 °C, stirred at -20 °C for 5 min and then cooled again to - 75 °C.

[1375] 35 Foreignfiling text P24-166-SEC-WO01

[1376] 256

[1377] At -75 °C to -65 °C trimethyl borate (20 ml, 0.176 mol) is added, stirred for 30 min at -75 °C. The mixture is slowly warmed up to -15 °C and stirred with 100 ml water.

[1378] 20 ml concentrated hydrochloric acid is added and stirred for 5 min. The organic phase is separated and the aqueous phase is extracted with MTBE. The combined

[1379] 5 organic phases are washed with NaCI solution and concentrated to 100 ml. The product is diluted with THF and alkalised with 15 ml 50% NaOH solution while stirring and cooling at 20 °C. A fine crystalline precipitate is formed, the suspension is cooled to approx. -10 °C, the solids are separated, washed with MTBE and dried under reduced pressure.

[1380] 20

[1381] Sodium metaborate tetrahydrate (2.30 g, 16.43 mmol) is placed in water, 20 ml THF, hydrazinium hydroxide (0.02 ml, 0.412 mmol) and bis(tricyclohexylphosphine) palladium^ I) chloride (160 mg, 0.217 mmol) are added and stirred at room temperature for 5 min. The building block 1 (3.50 g, 10.91 mmol) and the building block 2 (4.00 g, 13.59 mmol) in 40 ml THF are added and refluxed overnight.

[1382] 25

[1383] The reaction mixture is diluted with water and MTBE and phases are separated. The aqueous phase is extracted with MTBE and the combined organic phases are washed with water, dried over sodium sulphate and concentrated under reduced pressure to yield 4.5 g of yellow crystals. The crude material is eluted with heptane over silica to give 2.0 g of white crystals, which are subsequently recrystallised from ethanol.

[1384] Example M1

[1385] 35 Foreignfiling text P24-166-SEC-WO01

[1386] 257

[1387] A nematic LC medium is formulated as follows:

[1388] 5

[1389] 15

[1390] 20

[1391] 25

[1392] Mixture Example S1 (stabilised with compound of Formula H-3-1)

[1393] A nematic LC mixture according to the invention is formulated as follows:

[1394] 35 Foreignfiling text P24-166-SEC-WO01

[1395] 258

[1396] Addition of 1 000 ppm of the compound of Formula H-3-1 significantly improves the

[1397] 5 VHR-ioo after UV exposure compared to the non-stabilized mixture M1, without affecting the remaining physical properties of the mixture M1.

[1398] Example M2

[1399] 15

[1400] A nematic LC medium is formulated as follows:

[1401] 20

[1402] 25

[1403] 35 Foreignfiling text P24-166-SEC-WO01

[1404] 259

[1405] 5

[1406] Mixture Example S2 (stabilised with compound of Formula ST-2-3)

[1407] A nematic LC mixture according to the invention is formulated as follows:

[1408] 15 Addition of 400 ppm of the compound of the Formula ST-2-3 significantly improves the VHR100 after UV exposure compared to the non-stabilized mixture M2, without affecting the remaining physical properties of the mixture.

[1409] 25 Example M3

[1410] A nematic LC medium is formulated as follows:

[1411] 35 Foreignfiling text P24-166-SEC-WO01

[1412] 260

[1413] 5

[1414] 15

[1415] Mixture Example S3 (stabilised with compound of Formula H -3-5}

[1416] 25

[1417] A nematic LC mixture according to the invention is formulated as follows:

[1418] Addition of 50 ppm of the compound of the Formula H-3-5 significantly improves the VHR100 after UV exposure compared to the non-stabilized mixture M3, without affecting the remaining physical properties of the mixture.

[1419] 35 Foreignfiling text P24-166-SEC-WO01

[1420] 261

[1421] Example M4

[1422] A nematic LC medium is formulated as follows:

[1423] 15

[1424] 20

[1425] 25

[1426] 35 Foreignfiling text P24-166-SEC-WO01

[1427] 262

[1428] 5

[1429] Mixture Example S4 (stabilised with compound of Formula ST-1-3)

[1430] A nematic LC mixture according to the invention is formulated as follows:

[1431] Addition of 400 ppm of the compound of the Formula ST-1-3 significantly improves the VHR100 after UV exposure compared to the non-stabilized mixture M4, without

[1432] 15 affecting the remaining physical properties of the mixture.

[1433] Example M5

[1434] 25 A nematic LC medium is formulated as follows:

[1435] 35 Foreignfiling text P24-166-SEC-WO01

[1436] 263

[1437] 5

[1438] 15

[1439] 20

[1440] Mixture Example S5 (stabilised with compound of Formula H-3-3)

[1441] 25

[1442] A nematic LC mixture according to the invention is formulated as follows:

[1443] Addition of 1 000 ppm of the compound of Formula H-3-3 significantly improves the VHR100 after UV exposure compared to the non-stabilized mixture M5, without affecting the remaining physical properties of the mixture.

[1444] 35 Foreignfiling text P24-166-SEC-WO01

[1445] 264

[1446] 5

[1447] Example M6

[1448] A nematic LC medium is formulated as follows:

[1449] 15

[1450] 20

[1451] 25

[1452] 35 Foreignfiling text P24-166-SEC-WO01

[1453] 265

[1454] Mixture Example S6 (stabilised with compound of Formula H-3-4)

[1455] A nematic LC mixture according to the invention is formulated as follows:

[1456] 5

[1457] Addition of 100 ppm of the compound of the Formula H-3-4 significantly improves the VHR100 after UV exposure compared to the non-stabilized mixture M6, without affecting the remaining physical properties of the mixture.

[1458] Example M7

[1459] 20

[1460] A nematic LC medium is formulated as follows:

[1461] 25

[1462] 35 Foreignfiling text P24-166-SEC-WO01

[1463] 266

[1464] 5

[1465] 15

[1466] 20

[1467] Mixture Example S7 (stabilised with compound of Formula ST-4-2)

[1468] 25

[1469] A nematic LC mixture according to the invention is formulated as follows:

[1470] Addition of 600 ppm of the compound of the Formula ST-4-2 significantly improves the VHR-|QQ after UV exposure compared to the non-stabilized mixture M7, without affecting the remaining physical properties of the mixture.

[1471] 35 Foreignfiling text P24-166-SEC-WO01

[1472] 267

[1473] Example M8

[1474] A nematic LC medium is formulated as follows:

[1475] 15

[1476] 20

[1477] 25

[1478] 35 Foreignfiling text P24-166-SEC-WO01

[1479] 268

[1480] 5

[1481] Mixture Example S8 (stabilised with compound of Formula H-3-2)

[1482] A nematic LC mixture according to the invention is formulated as follows:

[1483] 15

[1484] Addition of 50 ppm of the compound of the Formula H-3-2 significantly improves the VHR-|oo after UV exposure compared to the non-stabilized mixture M8, without affecting the remaining physical properties of the mixture.

[1485] 20

[1486] 25

[1487] Example M9

[1488] A nematic LC medium is formulated as follows:

[1489] 35 Foreignfiling text P24-166-SEC-WO01

[1490] 269

[1491] 5

[1492] 15

[1493] 20

[1494] 25

[1495] Mixture Example S9 (stabilised with compound of Formula H-3-6)

[1496] A nematic LC mixture according to the invention is formulated as follows:

[1497] 35 Foreignfiling text P24-166-SEC-WO01

[1498] 270

[1499] Addition of 50 ppm of the compound of the Formula H-3-6 significantly improves the VHR100 after UV exposure compared to the non-stabilized mixture M9, without affecting the remaining physical properties of the mixture.

[1500] 5

[1501] Example M10

[1502] 20

[1503] A nematic LC medium is formulated as follows:

[1504] 25

[1505] 35 Foreignfiling text P24-166-SEC-WO01

[1506] 271

[1507] 5

[1508] 15

[1509] 20

[1510] Mixture Example S10 (stabilised with compound of Formula H-3-7)

[1511] 25

[1512] A nematic LC mixture according to the invention is formulated as follows:

[1513] Addition of 500 ppm of the compound of Formula H-3-7 significantly improves the VHR100 after UV exposure compared to the non-stabilized mixture M10, without affecting the remaining physical properties of the mixture.

[1514] 35 Foreignfiling text P24-166-SEC-WO01

[1515] 272

[1516] Example M11

[1517] A nematic LC medium is formulated as follows:

[1518] 15

[1519] 20

[1520] 25

[1521] 35 Foreignfiling text P24-166-SEC-WO01

[1522] 273

[1523] 5

[1524] Mixture Example S11 (stabilised with compound of Formula H-3-8)

[1525] 15 A nematic LC mixture according to the invention is formulated as follows:

[1526] 20

[1527] Addition of 1000 ppm of the compound of Formula H-3-8 significantly improves the VHR-|oo after UV exposure compared to the non-stabilized mixture M11, without affecting the remaining physical properties of the mixture.

[1528] 25

[1529] 35 Foreignfiling text P24-166-SEC-WO01

[1530] 274

[1531] 15 Example M12

[1532] A nematic LC medium is formulated as follows:

[1533] 20

[1534] 25

[1535] 35 Foreignfiling text P24-166-SEC-WO01

[1536] 275

[1537] 5

[1538] 15

[1539] Mixture Example S12 (stabilised with compound of Formula H-3-12)

[1540] A nematic LC mixture according to the invention is formulated as follows:

[1541] 20

[1542] Addition of 100 ppm of the compound of the Formula H-3-12 significantly improves

[1543] 25 the VHR-|QQ after UV exposure compared to the non-stabilized mixture M12, without affecting the remaining physical properties of the mixture.

[1544] 35 Foreignfiling_text P24-166-SEC-WO01

[1545] 276

[1546] 20 A nematic LC medium is formulated as follows: Foreignfiling text P24-166-SEC-WO01

[1547] 277

[1548] 5

[1549] 15

[1550] 20

[1551] Mixture Example S13 (stabilised with compound of Formula H-3-17)

[1552] 25

[1553] A nematic LC mixture according to the invention is formulated as follows:

[1554] Addition of 100 ppm of the compound of the Formula H-3-17 significantly improves the VHR-|QQ after UV exposure compared to the non-stabilized mixture M13, without affecting the remaining physical properties of the mixture.

[1555] 35 Foreignfiling text P24-166-SEC-WO01

[1556] Example M14

[1557] A nematic LC medium is formulated as follows:

[1558] 15

[1559] 20

[1560] 25

[1561] 35 Foreignfiling text P24-166-SEC-WO01

[1562] 279

[1563] 5

[1564] Mixture Example S14 (stabilised with compound of Formula H-3-9)

[1565] A nematic LC mixture according to the invention is formulated as follows:

[1566] 15 Addition of 100 ppm of the compound of the Formula H-3-9 significantly improves the VHR100 after UV exposure compared to the non-stabilized mixture M14, without affecting the remaining physical properties of the mixture.

[1567] 20

[1568] 25

[1569] 35 Foreignfiling_text P24-166-SEC-WO01

[1570] 280

[1571] 35

Claims

Foreignfiling text P24-166-SEC-WO01281Patent Claims1. Liquid-crystalline medium, characterised in that it comprises one or more5 compounds of Formula Sin which the individual substituents, on each occurrence identically or differently, and each, independently of one another, have the following meanings:152025R1 and R2 each, independently of one another, denote a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 to 12 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, -CH=CH-,, -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C35Foreignfiling text P24-166-SEC-WO01282 atoms, in which one or more H atoms may be replaced by a halogen atom; to 1. each, independently of one another, denote H, F or Cl;5 to yS each, independently of one another, denote a H atom, an alkyl group having 1 to 3 C atoms or an alkenyl group having 2 to 3 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, preferably H or CH3;Z1denotes -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2H4-,15-C2F4-, -CF2CH2-, -CH2CF2-, -CFHCFH-, -CFHCH2-, -CH2CFH-, -CF2CFH-, -CFHCF2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C=C- or a single bond; k denotes 0, 1 , 2 or 3, preferably 1.

202. Medium according to Claim 1 , characterised in that the one or more compounds of Formula S are selected from the group consisting of the following compounds:2535Foreignfiling text P24-166-SEC-WO0128325 in whichR1 and R^ each, independently of one another, denote an alkyl or an alkoxy group having 1 to 6 C atoms or an alkenyl or an alkenyloxy group having 2 to 6 C atoms in which one or more CH2 groups areor -O-CO- in such a way that O atoms are not linked directly to oneForeignfiling text P24-166-SEC-WO01284 another, and in which one or more H atoms may be substituted by a halogen atom; to yS each, independently from one another, denote a H atom or a methyl5 group, preferably a H atom; andU to l_6 each, independently from one another, denote a H atom, F or Cl.

3. Medium according to Claim 1 or 2, characterized in that it comprises one or more compounds selected from the group consisting of the following formulae:15in which the individual substituents have the following meanings:Foreignfiling text P24-166-SEC-WO01285, ngs given in Claim 1 for R^ and R2 to l_15respectively; andXO denotes a halogen atom, -CN, -SCN, -NCS or an alkyl or an alkoxy group having 1 to 6 C atoms or an alkenyl or an alkenyloxy group having 2 to 6 C atoms in which one or more H atoms has been20 substituted by a halogen atom.

4. Medium according to Claim 3, wherein the one or more compounds ofFormula II are selected from the following subformulae:Foreignfiling text P24-166-SEC-WO0128625have the meanings given in Formula II.

5. Medium according to Claim 3, wherein the one or more compounds of Formula III are selected from the following subformulae:Foreignfiling text P24-166-SEC-WO012871520Foreignfiling text P24-166-SEC-WO0128835Foreignfiling text P24-166-SEC-WO012892035Foreignfiling text P24-166-SEC-WO0129015 in which RO andhave the meanings given in Formula III.

6. Medium according to one or more of Claims 1 to 5, characterised in that it additionally comprises one or more compounds selected from the group20 consisting of the following formulae:35Foreignfiling text P24-166-SEC-WO01291in which RO, X^, U,have the meanings given in Claim 3; l_3 and l_4 each, independently of one another, have the meanings given for U;20 zo denotes -C2H4-, -(CH2)4-, -CH=CH-, -CF=CF-, -C2F4-, -CH2CF2-,-CF2CH2-, -CH2O-, -OCH2-, -COO-, -CF2O-, or -OCF2-, in theFormulae V and VI also a single bond; and25 s denotes 0 or 1.

7. Medium according to one or more of Claims 1 to 6, characterised in that it comprises one or more compounds selected from the group consisting of the following formulae35Foreignfiling text P24-166-SEC-WO01292have the meanings given in Claim 3 for R®,i to L®, X0 and Y®, respectively.

8. Medium according to one or more of Claims 1 to 7, characterized in that it comprises one or more compounds selected from the group consisting of the following formulae:35Foreignfiling text P24-166-SEC-WO0120have the meanings given in Claim 3 for R^ and X^, respectively.

9. Medium according to one or more of Claims 1 to 8, characterized in that it comprises one or more compounds selected from the group consisting of the35 following formulae:Foreignfiling text P24-166-SEC-WO012945in which R^have the meanings given in Claim 3 for R^ and X^, respectively.

10. Liquid-crystalline medium according to one or more of Claims 1 to 9, characterised in that it comprises one or more compounds selected from the group of Formulae N1 and N2:1520 in which35Foreignfiling text P24-166-SEC-WO0115 and Z^2 independently of one another and, if Z^1 occurs twice, also these independently of one another, denote -CH2CH2-, -COO-, trans- CH=CH-, frans-CF=CF-, -CH2O-, -CF2O-, -C=C- or a single bond,20 P denotes 0, 1 or 2,R41 and R42 each, independently of one another, denote an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 to 12 C atoms in which one or more non-adjacent CH2 groups25 are optionally substituted by -C=C-, -CF2O-, -OCF2-,, -O-, -CO-O- or -O-CO- in such a way that O atoms are notlinked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom;35Foreignfiling text P24-166-SEC-WO01296if present, each, independently of one another, denoteR51 and R$2 each, independently of one another, have the meanings of R^120 and R42; z51 to Z$3 each, independently of one another, have the meanings of Z^1 and Z^2, and25 i and j each, independently of one another, denote 0 or 1 , wherein or more, preferably one, of the aromatic rings may optionally be substituted by an alkyl group, preferably by methyl.

11. Medium according to Claim 10, characterized in that the compound of FormulaN1 is represented by one of the following formulae:35F oreig nfi li ng_text P24-166-SEC-WO01297Foreignfiling text P24-166-SEC-WO012985 in which the individual substituents have the following meanings:"alkyl" and "alkyl*' each, independently from one another, an alkyl group having 1 to 6 C atoms;"alkenyl" and "alkenyl*' each, independently of one another, alkenyl group having 2 to 6 C atoms.

12. Medium according to one or more of Claims 1 to 11, characterised in that it15 comprises from 10 % to 60 % by weight of compound of Formula Z1-1:Z1-12013. Medium according to Claim 10, characterised in that the compound of FormulaN2 is represented by one of the following formulae:35Foreignfiling text P24-166-SEC-WO0129920 in whichR1 and R2 each, independently of one another, denote n-alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms, and25 l_1 denotes, H, F or Cl.Liquid-crystalline medium of one or more of Claims 1 to 13, characterised in that it further comprises one or more compounds of Formula P35Foreignfiling text P24-166-SEC-WO01300 in which the individual substituents, on each occurrence identically or differently, and each, independently of one another, have the following meanings:R1 and R2 each, independently of one another, denote a H atom, a halogen atom, -CN, -SCN, -NCS, an alkyl or an alkoxy group having 1 to 12 C atoms15 or an alkenyl or an alkenyloxy group having 2 to 12 C atoms in which one or more non-adjacent CH2groups are optionally substituted20such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom;25U to l_4 each, independently of one another, denote H, F or Cl; to yS each, independently of one another, denote a H atom, an alkyl group having 1 to 3 C atoms or an alkenyl group having 2 to 3 C atoms inwhich one or more non-adjacent CH2groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, preferably H or CH3;35Foreignfiling text P24-166-SEC-WO01301Z1denotes -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2H4-,-C2F4-, -CF2CH2-, -CH2CF2-, -CFHCFH-, -CFHCH2-, -CH2CFH-, - CF2CFH-, -CFHCF2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-,5 -C=C- or a single bond; k denotes 0, 1 , 2 or 3, preferably 1.

15. Liquid-crystalline medium of one or more of Claims 1 to 14, characterised in that it further comprises one or more compounds of Formula B15in which the individual substituents, on each occurrence identically or differently, and each, independently of one another, have the following meanings:2025whereinR1 and R2 each, independently of one another, denote one of the meanings given for R^ and R^ in the Formula P;7^ -CH2O-, -O-, -C2H4-, -OCH2-, or a single bond;Y1-CH2-, -CH2CH2-, -CH=CH-, -CH2O-, -O- or -S-;L1 and L H, F or Cl, preferably H or F, very preferably F; k 0 or 1.35Foreignfiling text P24-166-SEC-WO0130216. Medium according to one or more of Claims 1 to 15, characterized in that it further comprises one or more compounds selected from the group consisting of compounds of the Formulae YA, YB, YC, YD, YE and YF:52035Foreignfiling text P24-166-SEC-WO01303 in which the individual substituents have the following meanings:R21 and R22 each, independently of one another, denote a H atom, a halogen atom, -CN, -SCN, -NCS, an alkyl or an alkoxy group having 1 to 12 C5 atoms or an alkenyl or an alkenyloxy group having 2 to 12 C atoms in which one or more non-adjacent CH2 groups are optionallyor -O-CO- in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen15 atom, and wherein in the Formula YD R21 is preferably different from cyclic alkyl or alkoxy; to l_3 each, independently of one another, denote F, Cl, CF3 or CHF2;20R23 denotes a H atom, an alkyl group having 1 to 3 C atoms or an alkenyl group having 2 to 3 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by -C=C-,-CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that25 O atoms are not linked directly to one another, preferably H or CH3;7^ and z2 each, independently of one another, denote a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -C=C-, -CH=CHCH2O; p 0, 1 or 2, and q 0 or 1.35Foreignfiling text P24-166-SEC-WO0130417. Medium according to one or more of Claims 1 to 16, characterized in that it comprises one or more compounds selected from the group consisting of the following formulae LP1 and LP2, preferably one or more compounds of Formula LP1 and one or more compounds of Formula LP2:515 in which the individual substituents have the following meanings:RO and R2 each, independently of one another, denote an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group20 having 2 or 12 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-,25such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be substituted by a cycloalkyl or a cycloalkoxy group having 3 to12 C atoms;X0 has one of the meanings givenin the Formula II;YO denote H or CH3; and m and n denotes 0 or 1.35Foreignfiling text P24-166-SEC-WO0130518. Medium according to one or more of Claims 1 to 17, characterised in that it comprises one or more compounds of the Formulae S, one or more compounds of the Formulae P and, optionally, one or more compounds5 selected from the group consisting of the Formulae Z1, Z2, Z3, Z4, Z5, III, IV, VI, XIV, XX, XII, XXIII, XXIX, XVI, XVIIa, XVIIb, XVIIc.

19. Medium according to one or more of Claims 1 to 18, characterized in that it comprises one or more compounds of the Formula S, one or more compounds10 of the Formula B and, optionally, one or more compounds selected from the group consisting of the Formulae LP1 and / or LP2.

20. Medium according to one or more of Claims 1 to 19, characterized in that it comprises one or more compounds of the Formula S, one or more compounds15 selected from those of formulae YA, YB, YC, YD, YE and YF and, optionally, one or more compounds selected from the group consisting of the Formulae XXIX, XXX and XXVI I la.

21. Process for the preparation of a liquid-crystalline medium according to one or20 more of Claims 1 to 20, characterised in one or more compounds of the Formula S are mixed with one or more mesogenic compounds and optionally one or more polymerizable compounds and / or one or more additives.

22. A compound of Formula S2530in which the individual substituents, on each occurrence identically or differently, and each, independently of one another, have the following meanings:35Foreignfiling text P24-166-SEC-WO01306R1 and R2 each, independently of one another, denote a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 to 12 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, -CH=CH-,15, -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen20 atom; to each, independently of one another, denote H, F or Cl; to yS each, independently of one another, denote a H atom, an alkyl group25 having 1 to 3 C atoms or an alkenyl group having 2 to 3 C atoms in which one or more non-adjacent CH2 groups are optionally substituted by -C=C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, preferably H or CH3;Z1denotes -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2H4-,-C2F4-, -CF2CH2-, -CH2CF2-, -CFHCFH-, -CFHCH2-, -CH2CFH-,35Foreignfiling text P24-166-SEC-WO01307-CF2CFH-, -CFHCF2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C=C- or a single bond; k denotes 0, 1, 2 or 3.

523. Process for preparation of compound of Formula S according to Claim 22, characterised in that the building blocks 1 and 2 undergo a transition metal catalyzed cross coupling reaction to form the compound of Formula Swherein X is selected from Cl, Br, I, OMs, OTs or OTf, and15 M denotes a residue containing an atom selected from boron, zink, tin, silicon, lithium and magnesium.

24. Use of a liquid-crystalline medium according to one or more of Claims 1 to 20 for electro-optical purposes.2025. Electro-optical liquid-crystal display or an AR / VR headset containing a liquidcrystalline medium according to one or more of Claims 1 to 20.

26. Electro-optical liquid-crystal display according to Claim 25, characterized in that25 it is a TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-HB-FFS, PS-XB-FFS, SA-HB-FFS, SA-XB-FS, polymer stabilised SA-HB- FFS, polymer stabilised SA-XB-FFS, positive VA or positive PS-VA display.35

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