Compounds for a liquid-crystalline medium, and the use thereof for high-frequency components

Abstract

The present invention relates to compounds of the formula I ##STR00001##
where one or more of the radicals A.sup.1-5 denote a 1,4-naphthylene or 1,4- or 9,10-anthracenylene radical, and the other parameters are as defined in Claim 1. The invention additionally includes liquid-crystalline media which comprise the title compounds, and components for high-frequency technology which comprise these media, in particular phase shifters and microwave array antennae.

Claims

1. Compounds of the formula I ##STR00052## in which A.sup.1-5, independently of one another, denote a) a radical of the formula ##STR00053## b) 1,4-phenylene, in which one or more CH groups may be replaced by N, c) trans-1,4-cyclohexylene or cyclohexenylene, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O and/or S and in which H may be replaced by F, or d) a radical from the group 1,4-bicyclo[2.2.2]octylene, cyclobut-1,3-diyl, spiro[3.3]heptane-2,6-diyl, ##STR00054## and in which, in groups a), b), c) and d), one or more H atoms may also be replaced by Br, Cl, F, CN, NCS, SCN, SF.sub.5, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.10 alkoxy or a mono- or polyfluorinated C.sub.1-C.sub.10 alkyl or alkoxy group, and where at least one radical from A.sup.1 to A.sup.5 represents a radical according to a), R.sup.1 and R.sup.2 each, independently of one another, denote a halogenated or unsubstituted alkyl radical having 2 to 10 C atoms, where, in addition, one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by CC, CHCH, CFCF, CFCH, CHCF, (CO)O, O(CO), (CO) or S in such a way that O or S atoms are not linked directly to one another, or F, Br, CN, CF.sub.3, OCF.sub.3, SCN, NCS or SF.sub.5, Z.sup.2 denotes CC or ##STR00055## Y.sup.1, Y.sup.2, denote F, Z.sup.1, Z.sup.5, independently of one another, denote a single bond, CC, CHCH, CH.sub.2O, (CO)O, CF.sub.2O, CF.sub.2CF.sub.2, CH.sub.2CF.sub.2, CH.sub.2CH.sub.2, (CH.sub.2).sub.4, CHCF or CFCF, where asymmetrical bridges may be oriented to both sides, and m, n, independently of one another, denote 0, 1 or 2.

2. Compounds according to claim 1, characterised in that at least one group from A.sup.2, A.sup.3 and A.sup.4 denotes an optionally substituted 1,4-naphthylene radical or a 1,4-anthracenylene radical.

3. Compounds according to claim 1, characterised in that the compounds of the formula I contain one or two optionally substituted 1,4-naphthylene radicals or 1,4-anthracenylene radicals.

4. Compounds according to claim 1, characterised in that m and n are 0.

5. Liquid-crystal medium, characterised in that it comprises one or more compounds of the formula I ##STR00056## in which A.sup.1-5, independently of one another, denote a) a radical of the formula ##STR00057## b) 1,4-phenylene, in which one or more CH groups may be replaced by N, c) trans-1,4-cyclohexylene or cyclohexenylene, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O and/or S and in which H may be replaced by F, or d) a radical from the group 1,4-bicyclo[2.2.2]octylene, cyclobut-1,3-diyl, spiro[3.3]heptane-2,6-diyl, ##STR00058## and in which, in groups a), b), c) and d), one or more H atoms may also be replaced by Br, Cl, F, CN, NCS, SCN, SF.sub.5, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.10 alkoxy or a mono- or polyfluorinated C.sub.1-C.sub.10 alkyl or alkoxy group, and where at least one radical from A.sup.1 to A.sup.5 represents a radical according to a), R.sup.1 and R.sup.2 each, independently of one another, denote a halogenated or unsubstituted alkyl radical having 2 to 10 C atoms, where, in addition, one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by CC, CHCH, CFCF, CFCH, CHCF, (CO)O, O(CO), (CO) or S in such a way that O or S atoms are not linked directly to one another, or F, Br, CN, CF.sub.3, OCF.sub.3, SCN, NCS or SF.sub.5, Z.sup.2 denotes CC or ##STR00059## Y.sup.1, Y.sup.2, independently of one another, denote H, F, Cl, or C.sub.1-C.sub.10 alkyl, Z.sup.1, Z.sup.5, independently of one another, denote a single bond, CC, CHCH, CH.sub.2O, (CO)O, CF.sub.2O, CF.sub.2CF.sub.2, CH.sub.2CF.sub.2, CH.sub.2CH.sub.2, (CH.sub.2).sub.4, CHCF or CFCF, where asymmetrical bridges may be oriented to both sides, and m, n, independently of one another, denote 0, 1 or 2.

6. Liquid-crystal medium according to claim 5, characterised in that it additionally comprises one or more compounds selected from the compounds of the formula II: ##STR00060## in which L.sup.11 denotes R.sup.11 or X.sup.11, L.sup.12 denotes R.sup.12 or X.sup.12, R.sup.11 and R.sup.12, independently of one another, denote 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.11 and X.sup.12, independently of one another, denote F, Cl, Br, CN, NCS, SCN, SF.sub.5, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or fluorinated alkenyl, fluorinated alkenyloxy or fluorinated alkoxyalkyl having 2 to 7 C atoms, p denotes 0 or 1, Z.sup.11 to Z.sup.13, independently of one another, denote trans-CHCH, trans-CFCF, CC or a single bond, and ##STR00061## independently of one another, denote a) 1,4-phenylene, in which one or more, preferably one or two, CH groups may be replaced by N, b) trans-1,4-cyclohexylene or cyclohexenylene, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O and/or S and in which H may be replaced by F, and in which, in groups a) and b), one or more H atoms may also be replaced by Br, Cl, F, CN, NCS, SCN, SF.sub.5, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.10 alkoxy or a mono- or polyfluorinated C.sub.1-C.sub.10 alkyl or alkoxy group.

7. Liquid-crystal medium according to claim 5, characterised in that the concentration of the compounds of the formula I in the medium is in the range from in total 5% to 95%.

8. A method comprising adding a compound of the formula I according to claim 5 to a liquid-crystalline mixture.

9. A method comprising adding a compound of the formula I according to claim 1 to a component for high-frequency technology.

10. Process for the preparation of a liquid-crystal medium according to claim 5, characterised in that one or more compounds of the formula I are mixed with one or more further compounds and optionally with one or more additives.

11. Component for high-frequency technology, characterised in that it comprises a liquid-crystal medium according to claim 5.

12. Component according to claim 11, characterised in that it is one or more functionally connected phase shifters.

13. A method comprising incorporating a liquid-crystal medium according to claim 5 in a component for high-frequency technology.

14. Phase-controlled group antenna, characterised in that it comprises one or more components according to claim 11.

15. Liquid-crystal medium according to claim 5, wherein for one or more compounds of the formula I, Y.sup.1 and Y.sup.2 denote F.

Description

EXAMPLES

(1) The acetylenes and boronic acids employed are commercially available, the 1,1,2-trifluorotriethylsilylethene building block is synthesised by standard laboratory procedures.

Synthesis Example 1: 1-Iodo-4-bromonaphthalene

(2) ##STR00038##

(3) 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 of I.sub.2 (406 mmol) 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 NaHSO.sub.3 solution (w=39%).

(4) The phases are separated, and the aqueous phase is extracted once with MTB. The combined organic phases are washed with saturated sodium chloride solution, 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.

Synthesis Example 2: 1-Bromo-4-(4-n-propylphenylethynyl)naphthalene

(5) ##STR00039##

(6) 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 solution, 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.

Synthesis Example 3: 1-(4-n-Propylphenylethynyl)-4-(Z-1,2-difluoro-2-triethylsilylethylenyl)naphthalene

(7) ##STR00040##

(8) 4.9 g (13.2 mmol) of 1-bromo-4-(4-n-propylphenylethynyl)naphthalene are initially introduced in 100 ml of THF and cooled to 70 C., and 9 ml of n-BuLi (1.6 M in hexane, 14.3 mmol) are added dropwise. After 1 h, 4 g (19.6 mmol) of pure 1,1,2-trifluorotriethylsilylethene are added, and the batch is warmed overnight at RT, before being quenched by the addition of semisaturated ammonium chloride solution. The batch is diluted with MTB, and the phases are separated. The aqueous phase is extracted with MTB, the combined organic phases are washed with saturated sodium chloride solution, dried over sodium sulfate, filtered and evaporated in a rotary evaporator. The residue is purified by column chromatography (SiO.sub.2, heptane.fwdarw.heptane/MTB=10:1).

Synthesis Example 4: 1-(4-n-Propylphenylethynyl)-4-(E-1,2-difluoroethylenyl)naphthalene

(9) ##STR00041##

(10) The product obtained from the previous step (13.2 mmol) is initially introduced in 100 ml of THF and 5 ml of water, and 13 ml of a solution of tetrabutylammonium fluoride (1 M in THF, 13 mmol) are added. The batch is stirred overnight at RT and quenched by the addition of semi-saturated sodium chloride solution and MTB. The phases are separated, and the organic phase is dried over sodium sulfate, filtered and evaporated in a rotary evaporator. The residue is purified by column chromatography (SiO.sub.2, heptane).

Synthesis Example 5: 1-(4-n-Propylphenylethynyl)-4-(Z-1,2-difluoro-2-iodo-ethylenyl)naphthalene

(11) ##STR00042##

(12) The product obtained from the previous step (6 mmol) is initially introduced in 55 ml of THF and cooled to 70 C., and 4.3 ml of n-BuLi (1.6 M in hexane, 6.8 mmol) are added dropwise. After 1 h, 1.9 g (7.5 mmol) of iodine in 15 ml of THF are added, and the mixture is stirred at 60 C. for 1 h. The batch is subsequently warmed to 0 C. and quenched by the addition of water. 1 g (4 mmol) of sodium thiosulfate pentahydrate and MTB are then added, and the phases are separated. The aqueous phase is extracted with MTB, and the combined organic phases are washed with saturated sodium chloride solution, dried over sodium sulfate, filtered and evaporated in a rotary evaporator. The residue is purified by column chromatography (SiO.sub.2, heptane).

Synthesis Example 6: 1-(4-n-Propylphenylethynyl)-4-[E-1,2-difluoro-2-(4-trifluoromethylphenyl)ethylenyl]naphthalene

(13) ##STR00043##

(14) 2.48 mmol of iodide and 3.16 mmol of boronic acid are initially introduced in 30 ml of toluene, and 0.6 g (2.28 mmol) of Na.sub.2CO.sub.3 in 15 ml of water and 4 ml of EtOH are added, before 150 mg (0.13 mmol) of tetrakis(triphenylphosphine)palladium(0) are added. The batch is refluxed for 16 h and cooled, and the phases are separated. The aqueous phase is extracted with toluene, and the combined organic phases are washed with saturated sodium chloride solution, 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 heptane/EtOH=20:1.

(15) MS (EI): m/e (%)=476 (100, M.sup.+), 447 (58, [Methyl].sup.+)

(16) =+10.9

(17) n=0.33

(18) .sub.1=3238 mPa.Math.s

(19) C 125 N 167 I

(20) The following are prepared analogously to Synthesis Examples 1 to 6:

Synthesis Example 7: 1-(4-n-Propylphenylethynyl)-4-[E-1,2-difluoro-2-(4-n-butylphenyl)ethylenyl]naphthalene

(21) ##STR00044##

(22) The title compound is prepared analogously to Example 6 using 4-n-butyl-phenylboronic acid.

(23) MS (EI): m/e (%)=464 (100, M.sup.+), 435 (10, [Methyl].sup.+), 421 (7, [Mpropyl].sup.+), 392 (3, [Mpropyl-ethyl].sup.+), 196 (11, [Mpropylethyl].sup.2+).

(24) =+1.6

(25) n=0.34

(26) .sub.1=2244 mPa.Math.s

(27) Tg 34 C 67 N 181 I

Synthesis Example 8: 1-(4-n-Propylphenylethynyl)-4-[E-1,2-difluoro-2-(3,4,5-trifluorophenyl)ethylenyl]naphthalene

(28) ##STR00045##

Synthesis Example 9: 1-(4-n-Butylphenylethynyl)-4-[E-1,2-difluoro-2-(3,4,5-trifluorophenyl)ethylenyl]naphthalene

(29) ##STR00046##

(30) MS (EI): m/e (%)=476 (100, M.sup.+), 433 (65, [Mpropyl].sup.+).

(31) =+12.3

(32) n=0.31

(33) .sub.1=1627 mPa.Math.s

(34) C 111 N (87) I

Synthesis Example 10: 1-(4-n-Butylphenylethynyl)-4-[E-1,2-difluoro-2-(4-n-butylphenyl)ethylenyl]naphthalene (1)

(35) ##STR00047##

(36) MS (EI): m/e (%)=478 (100, M.sup.+), 435 (27, [Mpropyl].sup.+).

(37) =+0.8

(38) n=0.31

(39) .sub.1=2018 mPa.Math.s

(40) Tg 37 C 65 N 162 I

Synthesis Example 11: 1-(4-n-Butylphenylethynyl)-4-[E-1,2-difluoro-2-(2,3-difluoro-3-ethoxyphenyl)ethylenyl]naphthalene

(41) ##STR00048##

(42) MS (EI): m/e (%)=502 (100, M.sup.+), 459 (22, [Mpropyl].sup.+), 431 (18, [Mpropylethyl].sup.+).

(43) =3.6

(44) n=0.30

(45) .sub.1=3920 mPa.Math.s

(46) Tg 10 C 98 N 195 I

Synthesis Example 12: 1,4-Bis-[E-1,2-difluoro-2-(4-n-butylphenyl)-ethylenyl]naphthalene

(47) ##STR00049##

(48) MS (EI): m/e (%)=516 (100, M.sup.+).

(49) =+1.3

(50) n=0.23

(51) .sub.1=2855 mPa.Math.s

(52) C 88 N 141 I

Synthesis Example 13: 4-(2-{(4-[1,2-Difluoro-2-(4-methylnaphthalen-1-yl)-vinyl]naphthalen-1-yl}-1,2-difluorovinyl)-2-fluoro-4-pentyl[1,1;4,1]terphenyl

(53) ##STR00050##

(54) MS (EI): m/e (%)=708 (100, M.sup.+), 325.5 (12, [Mbutyl].sup.2+).

(55) C 205 N 312 I

Synthesis Example 14

(56) ##STR00051##

(57) MS (EI): m/e (%)=768 (100, M.sup.+), 690 (10, [MBr].sup.+).

(58) =+2.4

(59) n=0.41

(60) .sub.1=63815 mPa.Math.s

(61) C 176 N 318 I

Mixture Example 1

(62) A liquid-crystal mixture M-1 having the composition and properties as indicated in the following table is prepared. Compound (I) originates from Synthesis Example 10.

(63) TABLE-US-00004 Composition Compound No. Abbreviation 1 BCH-3F.F 10.8% 2 BCH-5F.F 9.00% 3 ECCP-30CF3 4.50% 4 ECCP-50CF3 4.50% 5 CBC-33F 1.80% 6 CBC-53F 1.80% 7 CBC-55F 1.80% 8 PCH-6F 7.20% 9 PCH-7F 5.40% 10 CCP-20CF3 7.20% 11 CCP-30CF3 10.8% 12 CCP-40CF3 6.30% 13 CCP-50CF3 9.90% 14 PCH-5F 9.00% 15 (1) 10.0% 100.0% Physical properties T(N, I) = 99 C. n (20 C., 589.3 nm) = 0.120 (20 C., 1 kHz) = 4.9 .sub.1 (20 C.) = 179 mPa .Math. s

(64) This mixture is used for applications in the microwave area, in particular for phase shifters (phased arrays).

(65) For comparison, a mixture C-1 without component (1) is prepared from compound Nos. 1-14 of M-1, where compound Nos. 1-14 are present in the same relative amounts.

(66) TABLE-US-00005 TABLE Properties of mixture M-1 and C-2 at 19 GHz (20 C.) Mixture .sub.r, .sub.r, tan .sub.,r, tan .sub.,r, M-1 2.58 2.33 0.097 0.0041 0.0125 7.79 C-1 2.49 2.30 0.079 0.0048 0.0139 5.70

(67) The tunability and the material quality are improved compared with comparative mixture C-1.

(68) Further combinations of the embodiments and variants of the invention in accordance with the description also arise from the following claims.