Compounds having a C—C triple bond

Abstract

Compounds containing at least one C—C triple bond within a chain of at least 3 ring systems which have positive dielectric anisotropy, the use thereof for high-frequency components, liquid-crystalline media containing these compounds, and high-frequency components, in particular antennae, especially for the gigahertz region, containing these media. The liquid-crystalline media serve, for example, for the phase shifting of microwaves for tuneable phased-array antennae.

Claims

1. A compound of formula I ##STR00053## in which H/F means H or F, A.sup.1-5 independently of one another, denote a) 1,4-phenylene, in which one or more CH groups are optionally replaced by N, or b) a radical of one of the following formulae ##STR00054##  wherein in a) and b), optionally one or more H atoms are independently replaced by L, which L in a) and b) each, independently of one another, denotes Br, Cl, F, CN, —NCS, —SCN, SF.sub.5, C.sub.1-C.sub.10 alkyl, C.sub.1-C.sub.10 alkoxy, C.sub.3-C.sub.6 cycloalkyl or a mono- or polyfluorinated C.sub.1-C.sub.10 alkyl or alkoxy group, and wherein one of the rings A.sup.3 and A.sup.4 denotes ##STR00055## Y denotes S or O, R.sup.1 denotes a halogenated or unsubstituted alkyl radical having 1 to 15 C atoms, in which one or more CH.sub.2 groups are optionally replaced, independently of one another, by —CH═CH—, —CF═CF—, —CF═CH—, —CH═CF—, —(CO)O—, —O(CO)—, —(CO)—, —O— or —S— in such a way that O or S atoms are not linked directly to one another, or denotes F, Cl, Br, CN, SCN, NCS or SF.sub.5, X denotes F, Cl, Br, CN, SCN, NCS, SF.sub.5 or a halogenated alkyl radical having 1 to 15 C atoms, in which one or more CH.sub.2 groups are optionally replaced, independently of one another, by —CH═CH—, —CF═CF—, —CF═CH—, —CH═CF—, —(CO)O—, —O(CO)—, —(CO)—, —O— or —S— in such a way that O or S atoms are not linked directly to one another, Z.sup.1, Z.sup.2, Z.sup.4, Z.sup.5 all denote a single bond, and m, n, p, q independently denote 0 or 1, where m+n+p+q is 1, 2, 3 or 4.

2. A compound according to claim 1, wherein A.sup.3 denotes 1,4-phenylene, in which one or more CH groups are optionally replaced by N.

3. A compound according to claim 1, wherein m and n are 0.

4. A compound according to claim 1, wherein A.sup.1, A.sup.2, A.sup.5 and one of A.sup.3 or A.sup.4, if present, each denote an optionally substituted 1,4-phenylene ring.

5. A compound according to claim 1, wherein m+n+p+q is 1.

6. A liquid-crystal medium, comprising one or more compounds according to claim 1.

7. A liquid-crystal medium according to claim 6, further comprising one or more compounds of formula II: ##STR00056## 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 alkynyl, 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, or 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, q independently denote 0 or 1, Z.sup.11 to Z.sup.13 independently of one another, denote trans-CH═CH—, trans-CF═CF—, —C≡C— or a single bond, and ##STR00057##  independently of one another, denote ##STR00058## L′ independently denotes branched or unbranched alkyl, alkenyl or alkynyl having 1 to 12 C atoms, in which, independently of one another, one or more CH.sub.2 groups are optionally replaced by O, or denotes C.sub.3-C.sub.6 cycloalkyl, C.sub.3-C.sub.6 cycloalkenyl, fluorinated alkyl or alkenyl, fluorinated alkoxy or alkenyloxy, F, Cl, Br, CN, NCS, SCN or SF.sub.5.

8. A liquid-crystal medium according to claim 6, wherein the concentration of the compounds of formula I in total is 5% to 95%.

9. A process for preparing a liquid-crystal medium according to claim 6, comprising mixing together one or more compounds of formula I with one or more further compounds and optionally with one or more additives.

10. A component for high-frequency technology, which contains a liquid-crystal medium according to claim 6.

11. A component according to claim 10, which comprises one or more functionally connected phase shifters.

12. A phased array antenna, which comprises one or more components according to claim 10.

13. A compound according to claim 1, wherein L each, independently of one another, denotes methyl, ethyl or straight or branched propyl.

14. A compound according to claim 1, wherein L each, independently of one another, denotes cyclopropyl.

15. A compound according to claim 1, wherein one of the rings A.sup.3 and A.sup.4 denotes ##STR00059##

16. A compound according to claim 1, wherein one of the rings A.sup.3 and A.sup.4 denotes ##STR00060##

17. A compound according to claim 1, wherein one of the rings A.sup.3 and A.sup.4 denotes ##STR00061##

18. A compound according to claim 1, wherein R.sup.1 denotes an unsubstituted alkyl radical having 1 to 15 C atoms, in which one or more CH.sub.2 groups are optionally replaced, independently of one another, by —CH═CH—, —CF═CF—, —CF═CH—, —CH═CF—, —(CO)O—, —O(CO)—, —(CO)—, —O— or —S— in such a way that O or S atoms are not linked directly to one another, or denotes F, Cl, Br, CN, SCN, NCS or SF.sub.5.

19. A compound according to claim 1, wherein X denotes F, Cl, Br, SCN, NCS, SF.sub.5 or a halogenated alkyl radical having 1 to 15 C atoms, in which one or more CH.sub.2 groups are optionally replaced, independently of one another, by —CC—, —CH═CH—, —CF═CF—, —CF═CH—, —CH═CF—, —(CO)O—, —O(CO)—, —(CO)—, —O— or —S— in such a way that O or S atoms are not linked directly to one another.

20. A compound according to claim 1, wherein m+n is 0 or 1.

Description

EXAMPLES

(1) The acetylenes and boronic acids employed are commercially available or can be prepared analogously to known syntheses which are known to the person skilled in the art. The radicals “C.sub.4H.sub.9” stand for unbranched n-butyl radicals. The same applies correspondingly to C.sub.3H.sub.7, C.sub.6H.sub.13, etc.

Synthesis Example 1

1.1 Synthesis of 1-bromo-3-ethyl-4-(4-n-butylphenylethynyl)benzene

(2) ##STR00037##

(3) 65 g (209 mmol) of 1-iodo-2-ethyl-4-bromobenzene and 38 g (226 mmol) of 4-n-butylphenylacetylene are initially introduced in 300 ml of NEt.sub.3, 1 g (5.3 mmol) of copper(I) iodide and 3.6 g (5.1 mmol) of bis(triphenylphosphine)palladium(II) chloride are added, and the mixture is stirred at RT for 2 h. 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); the product is obtained as a colourless oil.

1.2 Synthesis of 3-ethyl-4-(4-n-butylphenylethynyl)phenylboronic acid

(4) ##STR00038##

(5) 63 g (180 mmol) of the bromide obtained in the preceding reaction are initially introduced in 450 ml of tetrahydrofuran and cooled to −70° C., and 125 ml (1.6 M in hexane, 200 mmol) of n-butyllithium are added dropwise. After 1 h, 23 ml (203 mmol) of trimethyl borate in 50 ml of tetrahydrofuran are added, and the mixture is stirred at −70° C. for a further 2 h and warmed to 0° C. The mixture is then worked up using water and 1 M hydrochloric acid, MTB is added, 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 washed by stirring with heptane and filtered off. The boronic acid is obtained as a colourless solid.

1.3 Synthesis of 4-bromo-3-fluoro-3′-ethyl-4′-(4-n-butylphenylethynyl)biphenyl

(6) ##STR00039##

(7) 16.8 g (162 mmol) of sodium carbonate and 14.9 g (49 mmol) of 1-bromo-2-fluoro-4-iodobenzene are initially introduced in 60 ml of water and 75 ml of toluene and warmed to 70° C. 1.6 g (1.4 mmol) of tetrakis(triphenylphosphine)-palladium(0) and 15 g (49 mmol) of the boronic acid obtained in the preceding reaction in 50 ml of ethanol are then added dropwise, and the mixture is heated under reflux for 16 h. Work-up is carried out by addition of MTB and water. The phases are separated, and the aqueous phase is extracted twice 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/toluene=9:1); the further purification is carried out by recrystallisation from isopropanol.

1.4 Synthesis of 3,4,5-trifluoro-2′-fluoro-3″-ethyl-4″-(4-n-butylphenylethynyl)-p-terphenyl (1)

(8) ##STR00040##

(9) 3.3 g (31.1 mmol) of sodium carbonate and 5 g (11.5 mmol) of the bromide obtained in the preceding reaction are initially introduced in 15 ml of water and 60 ml of toluene and warmed to 70° C. 640 mg (0.55 mmol) of tetrakis-(tri-phenylphosphine)palladium(0) and 2.4 g (13.6 mmol) of 3,4,5-trifluorophenyl-boronic acid in 25 ml of ethanol are then added dropwise, and the mixture is heated under reflux for 16 h. Work-up is carried out by addition of MTB and water, the phases are separated, and 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/toluene=9:1). The further purification is carried out by recrystallisation from ethanol.

(10) MS (EI): m/e (%)=486 (100, M.sup.+), 443 (40, [M-propyl].sup.+).

(11) C, 76; N, 159; I.

(12) Δ∈=+16

(13) Δn=0.35

(14) γ.sub.1=2.5 Pa.Math.s

(15) The following are synthesised analogously or comparably:

2. 3-Fluoro-4-trifluoromethoxy-2′-fluoro-3″-ethyl-4″-(4-n-butylphenylethynyl)-p-terphenyl (2)

(16) ##STR00041##

(17) MS (EI): m/e (%)=534 (100, M.sup.+), 491 (45, [M-propyl].sup.+).

(18) C, 87; N, 198; I.

(19) Δ∈=13

(20) Δn=0.34

(21) γ.sub.1=2.8 Pa.Math.s

3. 3-Fluoro-4-cyano-2′-fluoro-3″-ethyl-4″-(4-n-butylphenylethynyl)-p-terphenyl

(22) ##STR00042##

(23) MS (EI): m/e (%)=475 (100, M.sup.+), 432 (43, [M-propyl].sup.+).

(24) C, 135; N, 262; I.

(25) Δ∈=29

(26) Δn=0.43

(27) γ.sub.1=18.0 Pa.Math.s

4. 3,5-Difluoro-4-trifluoromethoxy-2′-fluoro-3″-ethyl-4″-(4-n-butylphenyl-ethynyl)-p-terphenyl (4)

(28) ##STR00043##

(29) MS (EI): m/e (%)=552 (100, M.sup.+), 537 (7, [M-methyl].sup.+), 509 (45, [M-propyl].sup.+).

(30) C, 87; N, 169; I.

(31) Δ∈=17

(32) Δn=0.33

(33) γ.sub.1=2.4 Pa.Math.s

5. 3,5-Difluoro-4-trifluoromethyl-2′-fluoro-3″-ethyl-4″-(4-n-butylphenyl-ethynyl)-p-terphenyl

(34) ##STR00044##

(35) MS (EI): m/e (%)=536 (100, M.sup.+), 521 (6, [M-methyl].sup.+), 493 (50, [M-propyl].sup.+).

(36) C, 113; N, 144; I.

(37) Δ∈=22

(38) Δn=0.34

(39) γ.sub.1=3.4 Pa.Math.s

6. 3,4,5-Trifluoro-2′-fluoro-3″-ethyl-4″-(4-n-hexylphenylethynyl)-p-terphenyl

(40) ##STR00045##

(41) MS (EI): m/e (%)=514 (100, M.sup.+), 499 (6, [M-methyl].sup.+), 443 (44, [M-pentyl].sup.+).

(42) C, 77; N, 144; I.

(43) Δ∈=13

(44) Δn=0.34

(45) γ.sub.1=2.7 Pa.Math.s

7. 3,4,5-Trifluoro-3″-ethyl-4″-(4-n-butylphenylethynyl)-p-terphenyl

(46) ##STR00046##

(47) MS (EI): m/e (%)=468 (100, M.sup.+), 453 (8, [M-methyl].sup.+), 425 (39, [M-propyl].sup.+), 410 (21, [M-methyl-propyl].sup.+).

(48) C, 75; N, 184; I.

(49) Δ∈=12

(50) Δn=0.37

(51) γ.sub.1=2.2 Pa.Math.s

8. 3,4-Difluoro-3″-ethyl-4″-(4-n-butylphenylethynyl)-p-terphenyl

(52) ##STR00047##

(53) MS (EI): m/e (%)=450 (100, M.sup.+), 435 (8, [M-methyl].sup.+), 407 (35, [M-propyl].sup.+), 392 (22, [M-methyl-propyl].sup.+).

(54) C, 106; N, 231; I.

(55) Δ∈=7

(56) Δn=0.40

(57) γ.sub.1=3.9 Pa.Math.s

9. 3,4,5-Trifluoro-2′-fluoro-2″-fluoro-3″-propyl-4″-(4-n-butylphenylethynyl)-p-terphenyl

(58) ##STR00048##

(59) MS (EI): m/e (%)=518 (100, M.sup.+), 503 (5, [M-methyl].sup.+), 489 (26, [M-ethyl].sup.+), 475 (16, [M-propyl].sup.+), 461 (10), 446 (27).

(60) Tg −31 C, 95; N, 105; I.

(61) Δ∈=24

(62) Δn=0.30

(63) γ.sub.1=2.7 Pa.Math.s

10. 4-(3,4,5-Trifluorophenylethynyl)-3-ethyl-2′-fluoro-4″-n-butyl-p-terphenyl

(64) ##STR00049##

(65) MS (EI): m/e (%)=486 (100, M.sup.+), 443 (66, [M-propyl].sup.+), 428 (12, [M-methyl-propyl].sup.+).

(66) C, 89; N, 160; I.

(67) Δ∈=18

(68) Δn=0.35

(69) γ.sub.1=1.3 Pa.Math.s

11. 4-(3,4,5-Trifluorophenylethynyl)-3-ethyl-2′-fluoro-4′-n-butyl-p-biphenyl

(70) ##STR00050##

(71) MS (EI): m/e (%)=410 (100, M.sup.+), 395 (6, [M-methyl].sup.+), 367 (74, [M-propyl].sup.+), 352 (17, [M-methyl-propyl].sup.+).

(72) Tg −51 C, 25; I.

(73) Δ∈=10

(74) Δn=0.22

(75) γ.sub.1=0.2 Pa.Math.s

12. 4-(3,4,5-Trifluorophenylethynyl)-2-ethyl-2′,6′-difluoro-4′-n-butyl-p-biphenyl

(76) ##STR00051##

(77) MS (EI): m/e (%)=428 (100, M.sup.+), 413 (20, [M-methyl].sup.+), 385 (39, [M-propyl].sup.+), 370 (20, [M-methyl-propyl].sup.+).

(78) C, 59; I.

(79) Δ∈=14

(80) Δn=0.20

(81) γ.sub.1=0.2 Pa.Math.s

13. 3,4,5-Trifluoro-3′,4′-(n-butylphenylethynyl)-p-biphenyl

(82) ##STR00052##

(83) MS (EI): m/e (%)=392 (100, M.sup.+), 377 (10, [M-methyl].sup.+), 349 (84, [M-propyl].sup.+), 334 (36, [M-methyl-propyl].sup.+).

(84) Tg −47 I

(85) Δ∈=9

(86) Δn=0.25

(87) γ.sub.1=0.3 Pa.Math.s

Mixture Example 1

(88) A liquid-crystal medium M-1 having the composition and properties as indicated in the following table is prepared. Compound (1) (No. 15) originates from Synthesis Example 1.

(89) TABLE-US-00004 Composition Compound No. Abbreviation 1 BCH-3F.F 10.8% 2 BCH-5F.F 9.0% 3 ECCP-30CF3 4.5% 4 ECCP-50CF3 4.5% 5 CBC-33F 1.8% 6 CBC-53F 1.8% 7 CBC-55F 1.8% 8 PCH-6F 7.2% 9 PCH-7F 5.4% 10  CCP-20CF3 7.2% 11  CCP-30CF3 10.8% 12  CCP-40CF3 6.3% 13  CCP-50CF3 9.9% 14  PCH-5F 9.0% 15  (1) 10.0% Σ 100.0% Physical properties T(N, I) = 96° C. Δn (20° C., 589.3 nm) = 0.124 Δε (20° C., 1 kHz) = 4.9 γ.sub.1 (20° C.) = 166 mPa .Math. s

(90) This mixture is used for applications in the microwave region, in particular for phase shifters for phased-array antennae.

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

Mixture Examples 2 and 3

(92) Liquid-crystal media M-2 and M-3 having the composition of M-1 are prepared with the difference that for M-2, compound (2) from Synthesis Example 2 is employed instead of compound (1), and for M-3, compound (4) from Synthesis Example 4 is employed instead of compound (1).

(93) The results for the mixture examples are shown in the following table.

(94) TABLE-US-00005 TABLE Properties of mixtures M-1, M-2, M-3 and C-1 (comparison) at 19 GHz (20° C.) Mixture ε.sub.r, | | ε.sub.r, ⊥ τ tan δ.sub.ε, r, | | tan δ.sub.ε, r, ⊥ η M-1 2.63 2.29 0.130 0.0045 0.0116 11.2 M-2 2.64 2.31 0.127 0.0047 0.0129 9.82 M-3 2.62 2.30 0.125 0.0046 0.0119 10.46 C-1 2.56 2.29 0.107 0.0049 0.0126 8.50

(95) The tuneability τ and the material quality η are significantly improved for mixtures M-1, M-2 and M-3 compared with comparative mixture C-1.