Alkynyl-tolanes, liquid-crystal mixtures containing them and components for high-frequency technology

Abstract

Compounds of formula I ##STR00001##
their use in liquid-crystalline media, for example, for the phase shifting of microwaves for tunable phased-array antennae, and their use for high-frequency components, in particular antennae, especially for the gigahertz range.

Claims

1. A compound of formula I ##STR00054## in which ##STR00055## ##STR00056## where in the 1,4-phenylene groups, one CH group or two CH groups are optionally replaced by N, Y denotes S or O, L.sup.0 on each occurrence, independently of one another, denotes H, 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, R.sup.01 and R.sup.02 each, independently of one another, denote 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 CC, CHCH, CFCF, CFCH, CHCF, (CO)O, O(CO), (CO), O or S in such a way that O or S atoms are not linked directly to one another, and R.sup.01 also denotes ethynyl, and R.sup.03 and R.sup.04 each, independently of one another, denote a halogenated or unsubstituted alkyl radical having 1 to 6 C atoms, in which one or more CH.sub.2 groups are optionally replaced, independently of one another, by CC, CHCH, CFCF, CFCH, CHCF, (CO)O, O(CO), (CO), O or S in such a way that O or S atoms are not linked directly to one another.

2. The compound according to claim 1, wherein ##STR00057##

3. The compound according to claim 1, wherein ##STR00058##

4. The compound according to claim 1, wherein ##STR00059##

5. The compound according to claim 1, wherein R.sup.01 denotes alk-1-ynyl.

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

7. The liquid-crystal medium according to claim 6, further comprising one or more compounds of 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 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, 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-CHCH, trans-CFCF, CC or a single bond, ##STR00061## independently of one another, denote ##STR00062## L on each occurrence, independently of one another, denotes branched or unbranched alkyl, alkenyl or alkynyl having 1 to 12 C atoms, in which one or more CH.sub.2 groups are, independently of one another, 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. The liquid-crystal medium according to claim 6, wherein the concentration of the one or more compounds of formula I in the medium is in total 5% to 95%.

9. A process for preparing the liquid-crystal medium according to claim 6, comprising mixing the 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, comprising a liquid-crystal medium according to claim 6.

11. The component according to claim 10, which is a phase shifter or a plurality of functionally connected phase shifters.

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

13. The compound according to claim 1, wherein R.sup.03 and R.sup.04 each, independently of one another, denote a halogenated or unsubstituted alkyl radical having 1, 2 or 3 C atoms, in which one or more CH.sub.2 groups are optionally replaced, independently of one another, by CC, CHCH, CFCF, CFCH, CHCF, (CO)O, O(CO), (CO), O or S in such a way that O or S atoms are not linked directly to one another.

14. The compound according to claim 1, wherein R.sup.02 denotes a propyl, butyl, pentyl or hexyl radical.

15. The compound according to claim 4, which is ##STR00063##

16. A liquid-crystal medium, comprising one or more compounds according to claim 4.

17. The liquid-crystal medium according to claim 16, further comprising one or more compounds of formula II: ##STR00064## in which: L.sup.11 denotes R.sup.11 or X.sup.1, 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, 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-CHCH, trans-CFCF, CC or a single bond, ##STR00065## independently of one another, denote ##STR00066## and L on each occurrence, independently of one another, denotes branched or unbranched alkyl, alkenyl or alkynyl having 1 to 12 C atoms, in which one or more CH.sub.2 groups are, independently of one another, 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.

18. The liquid-crystal medium according to claim 16, wherein the concentration of the one or more compounds of formula I in the medium is in total 5% to 95%.

19. A component for high-frequency technology, comprising a liquid-crystal medium according to claim 16, and which is a phase shifter or a plurality of functionally connected phase shifters.

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

21. A compound of formula I ##STR00067## in which ##STR00068## where in the 1,4-phenylene groups, one CH group or two CH groups are replaced by N, which one CH group or two CH groups are present as a result of L.sup.0 being H on the carbon atom of said one CH group or two CH groups, ##STR00069## where in the 1,4-phenylene groups, one CH group or two CH groups are optionally replaced by N, L.sup.0 on each occurrence, independently of one another, denotes H, 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, R.sup.01 and R.sup.02 each, independently of one another, denote 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 CC, CHCH, CFCF, CFCH, CHCF, (CO)O, O(CO), (CO), O or S in such a way that O or S atoms are not linked directly to one another, and R.sup.01 also denotes ethynyl, and R.sup.03 and R.sup.04 each, independently of one another, denote a halogenated or unsubstituted alkyl radical having 1 to 6 C atoms, in which one or more CH.sub.2 groups are optionally replaced, independently of one another, by CC, CHCH, CFCF, CFCH, CHCF, (CO)O, O(CO), (CO), O or S in such a way that O or S atoms are not linked directly to one another.

22. The compound according to claim 1, wherein ##STR00070##

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 corresponding situation applies to C.sub.3H.sub.7, C.sub.5H.sub.11, C.sub.6H.sub.13, etc.

1. Synthesis Example 1: Synthesis of 1-(4-n-butylphenylethynyl)-2-methyl-4-propyn-1-ylbenzene (corresponds to 4-n-butylphenyl(2-methyl-4-propyn-1-ylphenyl)ethyne)

(2) ##STR00043##

(3) 1.1 Steps 1.1 and 1.2

(4) 6.8 g of 1-butyl-4-ethynylbenzene in 300 ml of THF are introduced into a 1 l apparatus which has been rendered inert with N.sub.2, and the mixture is cooled to 78 C. 41 ml of a 1M solution of lithium bis(trimethylsilyl)amide in n-hexane are added dropwise to this solution, and the mixture is stirred at 78 C. for 30 min. A clear, yellowish reaction mixture forms. 41 ml of a 1M solution of 9-methoxy-9-BBN are then added dropwise. A somewhat darker (pale-orange), clear reaction mixture forms. This is subsequently stirred at 78 C. for 40 min.

(5) 1.2 Step 1.3

(6) 6.3 g of 1-bromo-2-methyl-4-prop-1-ynylbenzene in 400 ml of THF are introduced into a further apparatus which has been rendered inert with N.sub.2, and the catalyst, bis(tricyclohexylphosphine)palladium(II) chloride, is added. The reaction mixture from the first step is then slowly added dropwise at RT. The mixture is subsequently heated under reflux for 12 hours with stirring.

(7) The mixture is subsequently subjected to conventional work-up. In detail, the mixture is cooled to RT, water and MTB are added, and the organic phase is extracted, washed and dried using sodium sulfate, giving a reddish-brown material as crude product. This is eluted over silica gel with heptane. The viscous liquid obtained in this way is crystallised twice from 15 times the amount of pentane at 40 C., giving the product

(8) ##STR00044##
in the form of yellowish crystals. The purity of the product is determined both by means of GC (99.4%) and also by means of HPLC (99.5%). The product is identified by means of mass spectrometry and NMR, and its physical properties are investigated. These are as follows:

(9) C 39 I; =+1.6; n=0.360 and .sub.1=223 mPa.Math.s.

2. Synthesis Example 2: Synthesis of 1-(4-n-butylphenylethynyl)-3-methyl-4-propyn-1-ylbenzene (corresponds to 4-n-butylphenyl-(3-methyl-4-propyn-1-ylphenyl)ethyne)

(10) ##STR00045##

(11) The product from step 1.2 of Example 1 is, as described in step 1.3, added to a solution of 1-bromo-3-methyl-4-prop-1-ynylbenzene. Reaction and work-up of the reaction mixture gives the product

(12) ##STR00046##

(13) T.sub.g 58 C 24 N (23.2) I; =1.4; n=0.347 and .sub.1=166 mPa.Math.s.

3. Comparative Synthesis Example 1: Synthesis of 1-(4-n-butylphenylethynyl)-2,3-dimethyl-4-propyn-1-ylbenzene (corresponds to 4-n-butylphenyl-(2,3-dimethyl-4-propyn-1-ylphenyl)ethyne)

(14) ##STR00047##

(15) The product from step 1.2 of Example 1 is, as described in step 1.3, added to a solution of 1-bromo-2,3-dimethyl-4-prop-1-ynylbenzene. Reaction and work-up of the reaction mixture gives the product

(16) ##STR00048##

(17) C 72 N (51) I; =2.6; n=0.350 and .sub.1=224 mPa.Math.s.

4. Synthesis Example 3: Synthesis of 1-(4-n-but-1-yn-1-ylphenylethynyl)-2,3-dimethyl-4-propyn-1-ylbenzene (corresponds to 4-n-but-1-yn-1-ylphenyl(2,3-dimethyl-4-propyn-1-ylphenyl)ethyne)

(18) ##STR00049##

(19) The reaction is carried out analogously to that described in Example 1. Reaction and work-up of the reaction mixture gives the product

(20) ##STR00050##

(21) C 119 N 127.7 I; =2.3; n=0.494 and .sub.1=610 mPa.Math.s.

(22) The following are synthesised analogously or in a comparable manner:

5. Substance Example 4

(23) ##STR00051##

(24) C 22 I; =0.5; n=0.408 and .sub.1=482 mPa.Math.s.

6. Substance Example 5

(25) ##STR00052##

(26) T.sub.g 52 I; =0.7; n=0.270 and .sub.1=356 mPa.Math.s.

7. Substance Example 6

(27) ##STR00053##

(28) C 87 I; =1.8; n=0.350 and .sub.1=108 mPa.Math.s.

Mixture Examples

Mixture Example 1

(29) 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.

(30) 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% 100.0% Physical properties T (N, I) = 90.2 C. n (20 C., 589.3 nm) = 0.123 (20 C., 1 kHz) = 4.8 .sub.1 (20 C.) = 139 mPa .Math. s

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

(32) For comparison, a medium CM-0 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 to 6 and Comparative Mixture Example 0

(33) Liquid-crystal media M-2 to M-6 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 (3) from Synthesis Example 3 is employed instead of compound (1), etc.

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

(35) TABLE-US-00005 TABLE 1 General physical properties of the mixtures Property Mixture T (N, I)/ C..sub.| n .sub.1/mPa .Math. s M-1 90.2 0.123 4.8 139 M-2 88.8 0.122 4.8 137 M-3 100.2 0.137 5.0 153 M-4 83.1 0.127 4.7 150 M-5 85.3 0.114 4.8 139 M-6 90.0 0.122 5.0 129 CM-0 92.0 0.097 5.2 t.b.d. t.b.d.: to be determined

(36) TABLE-US-00006 TABLE 2 Properties of the mixtures at 19 GHz (20 C.) Property Mixture .sub.r,|| .sub.r, tan .sub.,r,|| tan .sub.,r, M-1 2.63 2.29 0.131 0.0046 0.0118 11.3 M-2 2.56 2.26 0.118 0.0044 0.0118 10.0 M-3 2.68 2.32 0.135 0.0046 0.0120 11.3 M-4 t.b.d. t.b.d. t.b.d. t.b.d. t.b.d. t.b.d. M-5 t.b.d. t.b.d. t.b.d. t.b.d. t.b.d. t.b.d. M-6 t.b.d. t.b.d. t.b.d. t.b.d. t.b.d. t.b.d. CM-0 2.56 2.29 0.107 0.0049 0.0126 8.50 = tunability; = material quality; tan .sub.,r = dielectric loss factors, t.b.d.: to be determined

(37) The tunability and the material quality are significantly improved for mixtures M-1 to M-3 compared with comparative mixture CM-0 and comparative mixture CM-1.

(38) The results and the comparison with base mixture CM-0 are shown in Table 1. Compared with base mixture CM 0, both significantly increased tunability, and also better material quality are evident.