Mesogenic compounds, liquid-crystalline media and components for high-frequency technology

Abstract

A liquid-crystal medium containing a component A of one or more compounds of formula X ##STR00001##
the preparation thereof, and the use of these liquid-crystal media, in particular in components for high-frequency technology, and components of this type which contain the media, and the production and use of these components. The components are suitable for phase shifters in the microwave and millimeter wave region, for microwave and millimeter wave array antennae and for tuneable reflectarrays.

Claims

1. A liquid-crystal medium, comprising a component A which comprises one or more compounds of formula X, ##STR00364## in which L.sup.101 denotes H or F, X.sup.101 denotes NCS, Y.sup.101 denotes F, Y.sup.102 denotes H, F or Cl, R.sup.101 denotes unfluorinated alkyl or unfluorinated alkoxy, each having 1 to 15 C atoms, unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl, each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl, each having up to 15 C atoms, and R.sup.102 denotes unfluorinated alkyl having 2 to 5 C atoms or unfluorinated cycloalkyl or cycloalkenyl having 3 to 7 C atoms; and a component F which comprises one or more compounds of formula I-2 and/or of formula I-3 and/or of formula I-4 ##STR00365## in which R.sup.11 to R.sup.14 each, independently of one another, denotes unfluorinated alkyl or unfluorinated alkoxy, each having 1 to 15 C atoms, unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl, each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl, each having up to 15 C atoms, and alternatively one of R.sup.13 and R.sup.14 or both also denote H.

2. The liquid-crystal medium according to claim 1, wherein component A comprises one or more compounds of formula X-1 ##STR00366## in which X.sup.101, Y.sup.101, Y.sup.102, R.sup.101 and R.sup.102 have the meanings given under formula X.

3. A liquid-crystal medium, comprising a component A which comprises one or more compounds of formula X, ##STR00367## in which L.sup.101 denotes H or F, X.sup.101 denotes NCS, Y.sup.101 denotes F, Y.sup.102 denotes H, F or Cl, R.sup.101 denotes unfluorinated alkyl or unfluorinated alkoxy, each having 1 to 15 C atoms, unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl, each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl, each having up to 15 C atoms, and R.sup.102 denotes unfluorinated alkyl having 2 to 5 C atoms or unfluorinated cycloalkyl or cycloalkenyl having 3 to 7 C atoms; and a component F which comprises one or more compounds of formula I-2 and/or of formula I-3 and/or of formula I-4 ##STR00368## in which R.sup.11 to R.sup.14 each, independently of one another, denotes unfluorinated alkyl or unfluorinated alkoxy, each having 1 to 15 C atoms, unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl, each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl, each having up to 15 C atoms, and alternatively one of R.sup.13 and R.sup.14 or both also denote H; and one or more compounds of formula I-1 ##STR00369## in which L.sup.11 denotes alkyl having 1 to 6 C atoms, cycloalkyl having 3 to 6 C atoms, cycloalkenyl having 4 to 6 C atoms or halogen, X.sup.11 denotes H, alkyl having 1 to 3 C atoms or halogen, and R.sup.11 and R.sup.12 have the meanings given above.

4. The liquid-crystal medium according to claim 1, wherein component F comprises one or more compounds of formula I-2.

5. The liquid-crystal medium according to claim 3, wherein component F comprises one or more compounds of formula I-1, in which X.sup.11 denotes H.

6. The liquid-crystal medium according to claim 3, wherein component F comprises one or more compounds of formula I-1, in which X.sup.11 denotes F.

7. The liquid-crystal medium according to claim 1, which further, besides a component A, comprises one or more components selected from the group consisting of components B, C, D and E: a component B, which is a strongly dielectrically positive component, which has a dielectric anisotropy of 10 or more, a component C, which is a strongly dielectrically negative component, which has a dielectric anisotropy having a value of −5 or less, a component D, which has a dielectric anisotropy in the range from more than −5 to less than 10 and consists of compounds having seven or more five- or six-membered rings, and a component E, which has a dielectric anisotropy in the range from more than −5 to less than 10 and consists of compounds having up to six five- or six-membered rings.

8. The liquid-crystal medium according to claim 7, which comprises a component B.

9. The liquid-crystal medium according to claim 7, which comprises a component D.

10. The liquid-crystal medium according to claim 1, which further comprises one or more compounds of the formula VI ##STR00370## in which L.sup.61 denotes R.sup.61 and, in the case where Z.sup.61 and/or Z.sup.62 denote trans-CH═CH— or trans-CF═CF—, alternatively also denotes X.sup.61, L.sup.62 denotes R.sup.62 and, in the case where Z.sup.61 and/or Z.sup.62 denote trans-CH═CH— or trans-CF═CF—, alternatively also denotes X.sup.62, R.sup.61 and R.sup.62 each, independently of one another, denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, X.sup.61 and X.sup.62 each, independently of one another, denotes F or Cl, —CN, —NCS, —SF.sub.5, fluorinated alkyl or alkoxy having 1 to 7 C atoms or fluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2 to 7 C atoms, or —NCS, one of Z.sup.61 Z.sup.62 denotes trans-CH═CH—, trans-CF═CF— or —C≡C— and the other, independently thereof, denotes trans-CH═CH—, trans-CF═CF— or a single bond, and ##STR00371##  to ##STR00372##  each , independently of one another, denotes ##STR00373##

11. A process for preparing a liquid-crystal medium according to claim 1, comprising mixing together one or more compounds of formula X with one or more compounds of formula I-2 and/or of formula I-3 and/or of formula I-4, and optionally with one or more further compounds and/or with one or more additives.

12. A component for high-frequency technology, which contains a liquid-crystal medium according to claim 1.

13. A microwave antenna array, which comprises one or more components according to claim 12.

14. A method for tuning a microwave antenna array according to claim 13, comprising electrically addressing said component for high-frequency technology.

15. A liquid-crystal medium according to claim 1, wherein component A comprises one or more compounds of formula X-2 ##STR00374## in which X.sup.101, Y.sup.101,Y.sup.102, R.sup.101 and R.sup.102 having the meanings given under formula X.

16. The liquid-crystal medium according to claim 1, wherein R.sup.102 denotes unfluorinated cycloalkyl or cycloalkenyl having 3 to 7 C atoms.

17. The liquid-crystal medium according to claim 1, wherein component F comprises one or more compounds of formula I-3.

18. The liquid-crystal medium according to claim 1, wherein component F comprises one or more compounds of formula I-4.

19. A component for high-frequency technology, which contains a liquid-crystal medium according to claim 3.

20. A microwave antenna array, which comprises one or more components according to claim 19.

Description

EXAMPLES

(1) The following examples illustrate the present invention without limiting it in any way. However, it becomes clear to the person skilled in the art from the physical properties what properties can be achieved and in what ranges they can be modified. In particular, the combination of the various properties which can preferably be achieved is thus well defined for the person skilled in the art.

(2) The acetylenes employed, if not commercially available, are synthesised in accordance with standard laboratory procedures.

Substance Examples A

Illustrative Compounds of the Formula X for Component A

Synthesis Example 1a

Synthesis of 2-cyclopropyl-1-(4-n-butylphenylethynyl)-4-[3,4,5-trifluorophenyl)ethynyl]benzene

(3) ##STR00311##

(4) The compound is prepared in accordance with Scheme 10 analogously to compounds described below in this application.

(5) MS (EI): m/e (%)=428 (100, M.sup.+), 385 (45, [M−propyl].sup.+).

(6) Phase sequence: C 84° C. I.

(7) Data extrapolated from 10% solution in ZLI-4792:

(8) Δ∈=+12.9; Δn=0.316 and γ.sub.1=687 mPa.Math.s.

Synthesis Example 2a

Synthesis of 1-fluoro-2-cyclopropyl-3-(4-n-butylphenylethynyl)-6-[3,4,5-trifluorophenyl)ethynyl]benzene

(9) ##STR00312##

(10) The compound is prepared in accordance with Scheme 10 analogously to compounds described below in this application.

(11) MS (EI): m/e (%)=446 (100, M.sup.+), 403 (41, [M−propyl].sup.+), 389 (70), 369 (22), 159 (84).

(12) Phase sequence: C 97° C. I.

(13) Data extrapolated from 10% solution in ZLI-4792:

(14) Δ∈=+18.4; Δn=0.326 and γ.sub.1=603 mPa.Math.s.

Substance Examples B

Illustrative compounds of the formula I for component F

Substance Example 1b

(15) ##STR00313##

(16) Phase sequence: C 87° C. N 178.5° C. I; Δn=0.436; Δ∈=2.8.

Substance Example 2b

(17) ##STR00314##

(18) Phase sequence: C 78° C. N 172.3° C. I; Δn=0.437; Δ∈=2.6.

Substance Example 3b

(19) ##STR00315##

(20) Phase sequence: C 107° C. N 211.0° C. I; Δn=0.464; Δ∈=3.1.

Substance Example 4b

(21) ##STR00316##

(22) Phase sequence: C 87° C. N 130.7° C. I; Δn=0.451; Δ∈=2.1.

Substance Example 5b

(23) ##STR00317##

(24) Phase sequence: C 57° C. N 151.7° C. I; Δn=0.445; Δ∈=2.0.

Substance Example 6b

(25) ##STR00318##

(26) Phase sequence: C 29° C. N 119.2° C. I; Δn=0.402; Δ∈=1.7.

Substance Example 7b

(27) ##STR00319##

(28) Phase sequence: T.sub.g −54° C. C 14° C. N 119.2° C. I; Δn=0.393; Δ∈=1.8.

Substance Example 8b

(29) ##STR00320##

(30) Phase sequence: C 60° C. N 121.8° C. I; Δn=0.394; Δ∈=1.7.

Substance Example 9b

(31) ##STR00321##

(32) Phase sequence: C 81° C. N 160.7° C. I; Δn=0.432; Δ∈=3.2.

Substance Example 10b

(33) ##STR00322##

Synthesis Example 10

1,4-Bis(2-(4-butylphenyl)ethynyl)-2-cyclopropylbenzene

10b.1) 1,4-Dichloro-2-cyclopropylbenzene (2)

(34) ##STR00323##

(35) 20 g (73 mmol) of 1,4-dichloro-2-iodobenzene, 9.4 g (110 mmol) of cyclopropylboronic acid, 32 g (147 mmol) of potassium phosphate, 421 mg (0.7 mmol) of bis(dibenzylideneacetone)palladium(0) (Pd(dba).sub.2) and 1096 mg (1.5 mmol) of 1,2,3,4,5-pentaphenyl-1-(di-t-butylphosphine)ferrocene (CTCQ-PHOS) are dissolved in 600 ml of toluene and heated at 100° C. overnight. 100 ml of water are added to the cooled solution, and the mixture is extracted twice with toluene (100 ml). The combined organic phases are washed with water, dried over sodium sulfate and evaporated in vacuo. The residue is purified by column chromatography, giving the title compound as a colourless solid.

10b.2) 1,4-Bis(2-(4-butylphenyl)ethynyl)-2-cyclopropylbenzene (1)

(36) ##STR00324##

(37) 5 g (26 mmol) of 1,4-dichloro-2-cyclopropylbenzene, 9.4 g (58 mmol) of 1-n-butyl-4-ethynylbenzene, 19 g (58 mmol) of caesium carbonate, 69 mg (0.3 mmol) of bis(acetonitrile)palladium(II) chloride and 382 mg (0.8 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl are dissolved in 80 ml of dioxane under nitrogen, and the mixture is heated at 100° C. overnight. 100 ml of water are added to the cooled solution, and the mixture is extracted twice with methyl t-butyl ether (100 ml). The combined organic phases are washed with water, dried over sodium sulfate and evaporated in vacuo. The residue is purified by column chromatography and recrystallised from ethanol, giving the title compound I as a solid.

(38) .sup.1H-NMR (250 MHz, CDCl.sub.3): 7.4-7.08 (11H, m); 2.5 (4H, m); 1.6-1.3 (9H, m); 0.96 (6H, m); 0.6-0.4 (4H, m).

(39) Phase sequence: C 72° C. N 84.5° C. I; Δn=0.378; Δ∈=1.5.

Substance Example 11b

(40) ##STR00325##

(41) Phase sequence: T.sub.g −43° C. C 46° C. N 86.0° C. I; Δn=0.379; Δ∈=1.1.

Substance Example 12b

(42) ##STR00326##

Synthesis Example 12b

1,4-Bis(2-(4-butylphenyl)ethynyl)-2-cyclobutylbenzene (3)

(43) ##STR00327##

12b.1) 1-(2,5-Dibromophenyl)cyclobutanol (4)

(44) ##STR00328##

(45) 21.09 g (67 mmol) of 1,2,4-tribromobenzene are initially introduced in 100 ml of THF under nitrogen, cooled to −45° C., and a solution (1.3 M) of 51.54 ml (67 mmol) of isopropylmagnesium chloride/lithium chloride complex in THF is added dropwise. After 1 hour, the batch is warmed to −10° C., and 5 ml (66.34 ml) of cyclobutanone are added dropwise at this temperature. The batch is allowed to thaw, and sat. NH.sub.4Cl solution is added, the mixture is extracted with methyl t-butyl ether, the organic phase is dried over sodium sulfate and filtered, the solvent is removed in vacuo, and the residue is filtered through silica gel with dichloromethane, giving 4, which is employed in the next step without further purification.

12b.2) 1,4-Dibromo-2-cyclobutylbenzene (5)

(46) ##STR00329##

(47) 14.5 g (47.39 mmol) of 4 are dissolved in 50 ml of THF under nitrogen, and 35.72 ml (284.4 mmol) of boron trifluoride/diethyl ether complex are added dropwise at room temperature, and 12.54 g (189.6 mmol) of sodium cyanoborohydride are added dropwise in portions. The batch is heated under reflux overnight. The batch is allowed to cool to room temperature, sat. NaHCO.sub.3 solution is added, the mixture is extracted with methyl t-butyl ether, the organic phase is dried over sodium sulfate and filtered, the solvent is removed in vacuo, and the residue is filtered through silica gel with 1-chlorobutane, giving 5 as a yellow liquid.

12b.3) 1,4-Bis(2-(4-butylphenyl)ethynyl)-2-cyclobutylbenzene (3)

(48) ##STR00330##

(49) 7.8 g (47.0 mmol) of 1-butyl-4-ethynylbenzene are initially introduced in 100 ml of THF under nitrogen, cooled to −78° C., and 63.32 ml (63.20 mmol) of a 1 M solution of lithium bis(trimethylsilyl)amide in hexane are added dropwise. After 1 hour, 63.22 ml (63.20 mmol) of a 1 M solution of 9-methoxy-9-BBN in hexane are added, and the mixture is left to stir at −78° C. for 2 hours. In a second apparatus, 6.8 g (23.45 mmol) of 5, 0.916 g (1.0 mmol) of tris(dibenzylideneacetone)dipalladium(0) and 1.64 g (4.0 mmol) of 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl in 100 ml of THF are initially introduced. The first solution is slowly added dropwise, and the batch is heated at 100° C. overnight. 100 ml of water are added to the cooled solution, and the mixture is extracted twice with methyl t-butyl ether (100 ml). The combined organic phases are washed with water, dried over sodium sulfate and evaporated in vacuo. The residue is purified by column chromatography and recrystallised from isopropanol, giving the title compound 3 as a solid.

(50) Phase sequence: T.sub.g −39° C. C 69° C. N 70.1° C. I; Δn=0.359; Δ∈=0.9.

Substance Example 13b

(51) ##STR00331##

(52) Phase sequence: T.sub.g −36° C. C 57° C. N (?) (7.0)° C. I; Δn=0.334; Δ∈=−0.1.

Substance Example 14b

(53) ##STR00332##

(54) Phase sequence: T.sub.g −34° C. C 47° C. N 53.1° C. I; Δn=0.337; Δ∈=0.0.

Substance Example 15b

(55) ##STR00333##

Synthesis Example 15b

2-Cyclohexyl-4-(4-hexylphenylethynyl)-1-(4-propylphenylethynyl)benzene (6)

15b.1) 4-Chloro-2-cyclohexylbenzene trifluoromethanesulfonate (7)

(56) ##STR00334##

(57) 19 g (90.2 mmol) of 4-chloro-2-cyclohexylbenzene are dissolved in 264 ml of dichloromethane, cooled to −5° C., and 4.64 ml (33.18 mmol) of triethylamine and 223 mg (1.8 mmol) of 4-(dimethylamino)pyridine are added dropwise. The batch is stirred at room temperature overnight and filtered through silica gel with dichloromethane, giving the product 7, which is employed in the next step without further purification.

15b.2) (4-Chloro-2-cyclohexylphenylethynyl)trimethylsilane (8)

(58) ##STR00335##

(59) 21 g (61.3 mmol) of 7, 25.8 ml (183.8 mmol) of trimethylsilylacetylene, 2.15 g (3 mmol) of bis(triphenylphosphine)palladium(II) chloride and 21.2 ml (153.2 mmol) of triethylamine are dissolved in 60 ml of N,N-dimethylformamide under nitrogen, and the mixture is heated at 100° C. overnight. 100 ml of water are added to the cooled solution, and the mixture is extracted twice with methyl t-butyl ether (100 ml). The combined organic phases are washed with water, dried over sodium sulfate and evaporated in vacuo. The residue is purified by column chromatography, giving the product 8, which is employed in the next step without further purification.

15b.3) 4-Chloro-2-cyclohexyl-1-ethynylbenzene (9)

(60) ##STR00336##

(61) 16.6 g (57.1 mmol) of 8 are dissolved in 154 ml of tetrahydrofuran, cooled to 0° C., and a 1 M solution of tetra-n-butylammonium fluoride (68.48 mmol) is added dropwise. The batch is stirred at room temperature overnight, water is added, the mixture is extracted with methyl t-butyl ether, the organic phase is dried over sodium sulfate and filtered, the solvent is removed in vacuo, and the residue is filtered through silica gel with heptane/toluene, giving the product 9, which is employed in the next step without further purification.

15b.4) 4-Chloro-2-cyclohexyl-1-p-tolylethynylbenzene (10)

(62) ##STR00337##

(63) 6.6 g (30.17 mmol) of 9, 7.28 g (30.17 mmol) of 1-bromo-4-hexylbenzene, 21.63 g (66.39 mmol) of caesium carbonate, 78 mg (0.3 mmol) of bis(acetonitrile)palladium(II) chloride and 431 mg (0.9 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl are dissolved in 90 ml of dioxane under nitrogen and heated at 100° C. overnight. 100 ml of water are added to the cooled solution, and the mixture is extracted twice with methyl t-butyl ether (100 ml). The combined organic phases are washed with water, dried over sodium sulfate and evaporated in vacuo. The residue is purified by column chromatography.

15b.5) 2-Cyclohexyl-4-(4-hexylphenylethynyl)-1-(4-propylphenylethynyl)benzene (6)

(64) ##STR00338##

(65) 4.5 g (11.87 mmol) of 10, 1.7 g (11.87 mmol) of 1-n-propyl-4-ethynylbenzene, 8.5 g (26.12 mmol) of caesium carbonate, 30 mg (0.1 mmol) of bis(acetonitrile)palladium(II) chloride and 170 mg (0.35 mmol) of 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl are dissolved in 35 ml of dioxane under nitrogen and heated at 100° C. overnight. 100 ml of water are added to the cooled solution, and the mixture is extracted twice with methyl t-butyl ether (100 ml). The combined organic phases are washed with water, dried over sodium sulfate and evaporated in vacuo. The residue is purified by column chromatography, giving the title compound 6 as a solid.

(66) Phase sequence: T.sub.g −23° C. I; Δn=0.294; Δ∈=−0.6.

Substance Example 16b

(67) ##STR00339##

(68) The compound is prepared in accordance with Scheme 10 analogously to other syntheses described in this application.

(69) Phase sequence: C 90° C. N 193.9° C. I; Δn=0.435; Δ∈=3.0.

Substance Example 17b

(70) ##STR00340##

(71) The compound is prepared in accordance with Scheme 10 analogously to other syntheses described in this application.

(72) Phase sequence: C 53° C. N 143.5° C. I; Δn=0.401; Δ∈=2.5.

Substance Example 18b

(73) ##STR00341##

(74) The compound is prepared in accordance with Scheme 10 analogously to other syntheses described in this application.

(75) Phase sequence: T.sub.g −49 C 32° C. N 126.0° C. I; Δn=0.373; Δ∈=1.6.

Substance Example 19b

(76) ##STR00342##

Substance Example 20b

(77) ##STR00343##

(78) Phase sequence: T.sub.g −45° C. C 60° C. N 89.1° C. I; Δn=0.348; Δ∈=1.3.

Substance Example 21b

(79) ##STR00344##

(80) Phase sequence: T.sub.g −32° C. C 66° C. N (44.1)° C. I; Δn=0.322; Δ∈=0.6.

Substance Example 22b

(81) ##STR00345##

(82) Phase sequence: T.sub.g −37° C. C 52° C. N 78.2° C. I; Δn=0.339; Δ∈=0.9.

Synthesis Example 23b

(83) ##STR00346##
Step 23b.1

(84) ##STR00347##

(85) 25.4 g of 2-bromo-1,4-dichlorobenzene, 8.9 ml of iodoethane and 13.3 ml of DMPU are dissolved in 230 ml of THF, and a solution of 16.2 g of lithium tetramethylpiperidide in THF is added dropwise at −70° C. After a further 2 h at −70° C., the reaction mixture is allowed to warm to ambient temperature, and the batch is hydrolysed using water and subjected to extractive work-up. The crude product is purified by fractional distillation.

(86) B.p.: 73° C./0.1 bar. Colourless liquid.

(87) Step 23b.2

(88) ##STR00348##

(89) 12.5 ml of a 5% solution of methyllithium in diethyl ether are added to 2.4 g of anhydrous zinc bromide in 50 ml of THF at 25-40° C. 0.3 g of PdCl.sub.2-dppf, bis(diphenylphosphinoferrocene)palladium dichloride, is then added, the mixture is heated to the boil, and 4.6 g of the product from step 1.1, dissolved in a little THF, are added dropwise. The reaction mixture is subsequently heated under reflux for 15 h. The batch is hydrolysed using water and subjected to extractive work-up. The crude product is purified by chromatography (pentane/silica gel). Colourless liquid.

(90) Step 23b.3

(91) ##STR00349##

(92) 2.4 g of 4-butylphenylacetylene are initially introduced in 30 ml of THF and cooled to −78° C. 14.3 ml of a 1 M solution of lithium bis(trimethylsilyl)amide in hexane are added dropwise to this solution and allowed to react at −78° C. for a further 1 h. 14.3 ml of a 1 M solution of methoxy-9-BBN are then added dropwise, and the mixture is stirred at −78° C. for a further 2 h. In a second apparatus, 1.0 g of the product from the last step, dissolved in 40 ml of THF, is initially introduced with the catalyst comprising 0.2 g of tris(dibenzylideneacetone)dipalladium and 0.35 g of 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl, and the reaction solution from the first reaction is added at room temperature. The mixture is heated at the boil for 15 h. The batch is hydrolysed using water and subjected to extractive work-up. The crude product is purified by chromatography (pentane/silica gel). Recrystallisation from pentane gives the purified title product.

(93) Phase sequence: C 45° C. N 180° C. I.

Substance Example 24b

(94) ##STR00350##

(95) The compound is prepared analogously to Example 23b.

(96) Phase sequence: C 118° C. N 222° C. I; Δn=0.435; Δ∈=2.6.

Substance Example 25b

(97) ##STR00351##

(98) The title compound is prepared analogously to Example 23b.

(99) Phase sequence: C 41° C. N 161° C. I.

Substance Example 26b

(100) ##STR00352##

26b.1) Synthesis of 1-iodo-4-bromonaphthalene

(101) ##STR00353##

(102) 100 g (350 mmol) of 1,4-dibromonaphthalene are initially introduced in 1 l of THF, cooled to −70° C., and 235 ml of n-BuLi (1.6 M in hexane, 370 mmol) are added dropwise. After 1 h, 103 g (406 mmol) of I.sub.2 in 250 ml of THF are added dropwise, the mixture is stirred at −70° C. for a further 2 h, warmed to 0° C. and quenched by the addition of 50 ml (644 mmol) of aqueous NaHSC.sub.3 solution (w=39%). The phases are separated, and the aqueous phase is extracted once with MTB. The combined organic phases are washed with saturated sodium chloride soln., dried over sodium sulfate, filtered and evaporated in a rotary evaporator. The residue is purified by column chromatography (SiO.sub.2, heptane), and the further purification is carried out by recrystallisation from isopropanol, giving 1-iodo-4-bromonaphthalene as a yellow solid.

26b.2) Synthesis of 1-bromo-4-(4-n-propylphenylethynyl)naphthalene

(103) ##STR00354##

(104) 15.3 g (43.6 mmol) of 1-iodo-4-bromonaphthalene and 7.25 g (5.3 mmol) of 4-n-propylphenylacetylene are initially introduced in 200 ml of NEt.sub.3, 170 mg (0.9 mmol) of copper(I) iodide and 600 mg (0.9 mmol) of bis(triphenylphosphine)palladium(II) chloride are added, and the mixture is refluxed for 30 minutes. The batch is cooled, water and heptane are added, and the phases are separated. The organic phase is washed with saturated sodium chloride soln., dried over sodium sulfate, filtered and evaporated in a rotary evaporator. The residue is purified by column chromatography (SiO.sub.2, heptane), and the further purification is carried out by recrystallisation from isopropanol.

26b.3) Synthesis of 1-(4-n-butylphenylethynyl)-4-(4-n-propylphenylethynyl)naphthalene

(105) ##STR00355##

(106) 2.35 g (6.3 mmol) of 1-bromo-4-(4-n-propylphenylethynyl)naphthalene and 1.33 g (8.4 mmol) of 4-n-butylphenylacetylene are initially introduced in 40 ml of NEt.sub.3, 60 mg (0.3 mmol) of copper(I) iodide and 200 mg (0.3 mmol) of bis(triphenylphosphine)palladium(II) chloride are added, and the mixture is refluxed for 18 h.

(107) The batch is cooled, water and heptane are added, and the phases are separated. The organic phase is washed with saturated ammonium chloride solution and subsequently with saturated sodium chloride soln., dried over sodium sulfate, filtered and evaporated in a rotary evaporator. The residue of compound (1) is purified by column chromatography (SiO.sub.2, heptane), and the further purification is carried out by recrystallisation from isopropanol.

(108) MS (EI): m/e (%)=426 (100, M.sup.+), 397 (11, [M−ethyl].sup.+), 383 (16, [M−propyl].sup.+), 354 (18, [M−ethylpropyl].sup.+), 177 (14, [M−ethylpropyl].sup.2+).

(109) Phase sequence: C 78° C. N 191° C. I; Δn=0.450; Δ∈=2.9.

Substance Example 27b

(110) ##STR00356##

(111) The compound is prepared analogously to Example 26b.

(112) Phase sequence: C 108° C. N 194° C. I.

Substance Example 28b

(113) ##STR00357##

(114) The compound is prepared analogously to Example 26b.

(115) Phase sequence: C 63° C. N 171.7° C. I; Δn=0.435; Δ∈=2.3.

Substance Example 29b

(116) ##STR00358##

(117) The compound is prepared analogously to Example 26b.

(118) Phase sequence: C 76° C. N 176.2° C. I; Δn=0.427; Δ∈=2.4.

Substance Example 30b

(119) ##STR00359##

(120) The compound is prepared analogously to Example 26b.

(121) Phase sequence: C 100° C. N 162° C. I.

Substance Example 31b

(122) ##STR00360##

(123) The compound is prepared analogously to Example 26b.

(124) Phase sequence: C 61° C. N 139° C. I.

Substance Example 32b

(125) ##STR00361##

(126) This compound is prepared analogously to the preceding compounds in accordance with the right-hand reaction path of Scheme 15.

(127) Phase sequence: C 85° C. N 202.4° C. I; Δn=0.446; Δ∈=2.0.

Substance Example 33b

(128) ##STR00362##

(129) The compound is prepared analogously to Example 32b.

(130) Phase sequence: C 112° C. N 253.5° C. I; Δn=0.484; Δ∈=4.1.

Substance Example 34b

(131) ##STR00363##

(132) This compound is prepared analogously to the preceding compounds in accordance with the left-hand reaction path of Scheme 15.

(133) Phase sequence: C 93° C. N 212.4° C. I; Δn=0.527; Δ∈=0.8.

Use Examples

Comparative Examples 1 to 3

(134) A liquid-crystalline substance having the abbreviation PTP(2)TP-6-3 is prepared by the method of Hsu, C. S., Shyu, K. F., Chuang, Y. Y. and Wu, S.-T., Liq. Cryst., 27 (2), (2000), pp. 283-287, and investigated with respect to its physical properties, in particular in the microwave region. The compound has a nematic phase and a clearing point (T(N,I)) of 114.5° C. Further physical properties at 20° C. are: n.sub.e (589.3 nm)=1.8563; Δn (589.3 nm)=0.3250; ∈.sub.∥ (1 kHz)=3.4; Δ∈ (1 kHz)=0.8 and γ.sub.1=2100 mPa.Math.s. The compound is suitable for applications in the microwave region and/or millimetre wave region, in particular for phase shifters.

(135) TABLE-US-00007 TABLE 1A Properties of the compound PTP(2)TP-6-3 at 30 GHz T/° C. Ε.sub.r,| | Ε.sub.r,⊥ τ tan δ.sub.Ε,r,| | tan δ.sub.Ε,r,⊥ η 20 3.22 2.44 0.242 0.0029 0.0064 37.9

(136) TABLE-US-00008 TABLE 1B Properties of the compound PTP(2)TP-6-3 at 19 GHz T/° C. Ε.sub.r,| | Ε.sub.r,⊥ τ tan δ.sub.Ε,r,| | tan δ.sub.Ε,r,⊥ η 20 3.35 2.42 0.278 0.0029 0.0061 45.2

(137) In addition, the properties of the compound n-1-pentyl-4′-cyanobiphenyl (also called PP-5-N or CB15) and the liquid-crystal mixture ZLI-4792 (product from Merck KGaA, Darmstadt, Germany) were investigated at 19 GHz. The results are summarised in Table 2.

(138) TABLE-US-00009 TABLE 2 Comparison of the properties of the various examples at 19 GHz and 20° C. Example LC Ε.sub.r,| | Ε.sub.r,⊥ τ tan δ.sub.Ε,r,Max. η Comp. 1 P2-6-3* 3.35 2.42 0.278 0.0061 45.2 Comp. 2 PP-5-N.sup.$ 3.06 2.66 0.131 0.0273 4.8 Comp. 3 ZLI.sup.§ 2.57 2.29 0.107 0.0126 8.5 1 M-1 2.63 2.30 0.125 0.0116 10.8 2 M-2 3.33 2.40 0.278 0.0058 48.2 3 M-3 3.28 2.50 0.239 0.0171 14.0 4 M-4 3.29 2.41 0.268 0.0098 27.4 5 M-5 2.63 2.29 0.129 0.0117 11.0 6 M-6 3.33 2.40 0.280 0.0058 48.0 Notes: *) P2-6-3: PTP(2)TP-6-3, LC: liquid crystal, .sup.$) PP-5-N: CB15 and .sup.§) ZLI: ZLI-4792

Example 1

(139) A liquid-crystal mixture M-1 having the composition and properties as indicated in the following table is prepared.

(140) TABLE-US-00010 Composition Compound No. Abbreviation c/% 1 PTPI(c3)TU-4-F 10.0 2 CP-5-F 9.0 3 CP-6-F 7.2 4 CP-7-F 5.4 5 CCP-2-OT 7.2 6 CCP-3-OT 10.8 7 CCP-4-OT 6.3 8 CCP-5-OT 9.9 9 CCEP-3-OT 4.5 10 CCEP-5-OT 4.5 11 CPG-3-F 10.8 12 CPG-5-F 9.0 13 CGPC-3-3 1.8 14 CGPC-5-3 1.8 15 CGPC-5-5 1.8 Σ 100.0 Physical properties T(N, I) = 84.5° C. Δn (20° C., 589.3 nm) = 0.119 Δε (20° C., 1 kHz) = 6.0 k.sub.11 (20° C.) = t.b.d. pN k.sub.33/k.sub.11 (20° C.) = t.b.d. V.sub.0 (20° C.) = t.b.d. V γ.sub.1 (20° C.) = t.b.d. mPa .Math. s Notes: t.b.d.: to be determined.

(141) This mixture is very highly suitable for applications in the microwave region and/or millimetre wave region, in particular for phase shifters.

(142) TABLE-US-00011 TABLE 3 Properties of mixture M-1 at 19 GHz T/° C. Ε.sub.r,| | Ε.sub.r,⊥ τ tan δ.sub.Ε,r,| | tan δ.sub.Ε,r,⊥ η 20 2.63 2.30 0.125 0.0047 0.0116 10.8

Example 2

(143) A liquid-crystal mixture M-2 having the composition and properties as indicated in the following table is prepared.

(144) TABLE-US-00012 Composition Compound No. Abbreviation c/% 1 PTPI(c3)TU-4-F 10.0 2 PTP(2)TP-6-3 90.0 Σ 100.0 Physical properties T(N, I) = 106° C. Δn (20° C., 589.3 nm) = t.b.d. Δε (20° C., 1 kHz) = t.b.d. k.sub.11 (20° C.) = t.b.d. pN k.sub.33/k.sub.11 (20° C.) = t.b.d. V.sub.0 (20° C.) = t.b.d. V γ.sub.1 (20° C.) = t.b.d. mPa .Math. s Notes: t.b.d.: to be determined.

(145) This mixture is very highly suitable for applications in the microwave region and/or millimetre wave region, in particular for phase shifters.

(146) TABLE-US-00013 TABLE 4 Properties of mixture M-2 at 19 GHz T/° C. Ε.sub.r,| | Ε.sub.r,⊥ τ tan δ.sub.Ε,r,| | tan δ.sub.Ε,r,⊥ η 20 3.33 2.40 0.278 0.0025 0.0058 48.2

Example 3

(147) A liquid-crystal mixture M-3 having the composition and properties as indicated in the following table is prepared.

(148) TABLE-US-00014 Composition Compound No. Abbreviation c/% 1 PTPI(c3)TU-4-F 10.0 2 PPTUI-3-2 18.0 3 PPTUI-3-4 18.0 4 GGP-3-CL 7.2 5 GGP-5-CL 18.0 6 GPEP-3-CL 4.5 7 PTP-2-O1 7.2 8 PTP-3-O1 8.1 9 CPGP-4-3 4.5 10  CPGP-5-3 4.5 Σ 100.0 Physical properties T(N, I) = 126.5° C. Δn (20° C., 589.3 nm) = t.b.d. Δε (20° C., 1 kHz) = t.b.d. k.sub.11 (20° C.) = t.b.d. pN k.sub.33/k.sub.11 (20° C.) = t.b.d. V.sub.0 (20° C.) = t.b.d. V γ.sub.1 (20° C.) = t.b.d. mPa .Math. s Notes: t.b.d.: to be determined.

(149) This mixture is very highly suitable for applications in the microwave region and/or millimetre wave region, in particular for phase shifters.

(150) TABLE-US-00015 TABLE 5 Properties of mixture M-3 at 19 GHz T/° C. Ε.sub.r,| | Ε.sub.r,⊥ τ tan δ.sub.Ε,r,| | tan δ.sub.Ε,r,⊥ η 20 3.28 2.50 0.239 0.0060 0.0171 14.0

Example 4

(151) A liquid-crystal mixture M-4 having the composition and properties as indicated in the following table is prepared.

(152) TABLE-US-00016 Composition Compound No. Abbreviation c/% 1 PTPI(c3)TU-4-F 10.0 2 PTPI(2)TP-6-3 58.5 3 GGP-3-CL 9.0 4 GGP-5-CL 22.5 Σ 100.0 Physical properties T(N, I) = 106.5° C. Δn (20° C., 589.3 nm) = t.b.d. Δε (20° C., 1 kHz) = t.b.d. k.sub.11 (20° C.) = t.b.d. pN k.sub.33/k.sub.11 (20° C.) = t.b.d. V.sub.0 (20° C.) = t.b.d. V γ.sub.1 (20° C.) = t.b.d. mPa .Math. s Notes: t.b.d.: to be determined.

(153) This mixture is very highly suitable for applications in the microwave region and/or millimetre wave region, in particular for phase shifters.

(154) TABLE-US-00017 TABLE 6 Properties of mixture M-4 at 19 GHz T/° C. Ε.sub.r,| | Ε.sub.r,⊥ τ tan δ.sub.Ε,r,| | tan δ.sub.Ε,r,⊥ η 20 3.29 2.41 0.268 0.0034 0.0098 27.4

Example 5

(155) A liquid-crystal mixture M-5 having the composition and properties as indicated in the following table is prepared.

(156) TABLE-US-00018 Composition Compound No. Abbreviation c/% 1 PTG(c3)TU-4-F 10.0 2 CP-5-F 9.0 3 CP-6-F 7.2 4 CP-7-F 5.4 5 CCP-2-OT 7.2 6 CCP-3-OT 10.8 7 CCP-4-OT 6.3 8 CCP-5-OT 9.9 9 CCEP-3-OT 4.5 10 CCEP-5-OT 4.5 11 CPG-3-F 10.8 12 CPG-5-F 9.0 13 CGPC-3-3 1.8 14 CGPC-5-3 1.8 15 CGPC-5-5 1.8 Σ 100.0 Physical properties T(N, I) = 88.1° C. Δn (20° C., 589.3 nm) = 0.120 Δε (20° C., 1 kHz) = 6.6 k.sub.11 (20° C.) = t.b.d. pN k.sub.33/k.sub.11 (20° C.) = t.b.d. V.sub.0 (20° C.) = t.b.d. V γ.sub.1 (20° C.) = 154 mPa .Math. s Notes: t.b.d.: to be determined.

(157) This mixture is very highly suitable for applications in the microwave region and/or millimetre wave region, in particular for phase shifters.

(158) TABLE-US-00019 TABLE 7 Properties of mixture M-5 at 19 GHz T/° C. Ε.sub.r,| | Ε.sub.r,⊥ τ tan δ.sub.Ε,r,| | tan δ.sub.Ε,r,⊥ η 20 2.63 2.29 0.129 0.0048 0.0117 11.0 Note: t.b.d.: to be determined.

Example 6

(159) A liquid-crystal mixture M-6 having the composition and properties as indicated in the following table is prepared.

(160) TABLE-US-00020 Composition Compound No. Abbreviation c/% 1 PTG(c3)TU-4-F 10.0 2 PTP(2)TP-6-3 90.0 Σ 100.0 Physical properties T(N, I) = 109° C. Δn (20° C., 589.3 nm) = t.b.d. Δε (20° C., 1 kHz) = t.b.d. k.sub.11 (20° C.) = t.b.d. pN k.sub.33/k.sub.11 (20° C.) = t.b.d. V.sub.0 (20° C.) = t.b.d. V γ.sub.1 (20° C.) = t.b.d. mPa .Math. s Notes: t.b.d.: to be determined.

(161) This mixture is very highly suitable for applications in the microwave region and/or millimetre wave region, in particular for phase shifters.

(162) TABLE-US-00021 TABLE 8 Properties of mixture M-6 at 19 GHz T/° C. Ε.sub.r,| | Ε.sub.r,⊥ τ tan δ.sub.Ε,r,| | tan δ.sub.Ε,r,⊥ η 20 3.33 2.40 0.280 0.0025 0.0058 48.0