AROMATIC ISOTHIOCYANATES

Abstract

The present invention relates to a compound of formula UI

##STR00001##

as defined in claim 1, to a liquid crystal medium comprising a compound of formula UI and to high-frequency components comprising these media, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, tunable filters, tunable metamaterial structures, and electronic beam steering antennas, e.g. phased array antennas.

Claims

1. A compound of formula UI ##STR00537## in which R.sup.U denotes H, straight-chain or branched non-fluorinated alkyl having 1 to 12 C atoms or non-fluorinated alkenyl having 2 to 12 C atoms, in which one or more CH.sub.2-groups may be replaced by ##STR00538## where one or more non-adjacent CH.sub.2-groups may be replaced by O, or denotes a group R.sup.P, R.sup.P denotes halogen, CN, NCS, fluorinated alkyl, R.sup.F—O— or R.sup.F—S—, wherein R.sup.F denotes fluorinated alkyl or fluorinated alkenyl having up to 9 C atoms, Z.sup.U1 denotes —CH═CH—, —CF═CF—, —CH═CF—, —CF═CH—, —C—C— or —C═C—C═C—, X.sup.U1, X.sup.U2, identically or differently, denote Cl or F, ##STR00539## denote a radical selected from the following groups: a) the group consisting of 1,4-phenylene, 1,4-naphthylene, and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L, b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, tetralin-2,6-diyl, tetralin-5,8-diyl, decalin-2,6-diyl, bicyclo[1.1.1]pentane-1,3-diyl, 4,4′-bicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl or spiro[3.3]heptane-2,6-diyl, in which one or two CH groups may be replaced by N, one or more non-adjacent CH.sub.2 groups may be replaced by —O— and/or —S— and in which one or more H atoms 2 MERCK-5145 may be replaced by L, c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl and selenophene-2,5-diyl, each of which may also be mono- or polysubstituted by L, L on each occurrence, identically or differently, denotes F, Cl, CN, SCN, SF.sub.5 or straight-chain or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy each having 1 to 12 C atoms, u is 0 or 1, v is 0 or 1, ##STR00540## with the proviso that and do not both denote optionally fluorinated 1,4-phenylene.

2. The compound according to claim 1, wherein the compound is selected from the group of compounds of the formulae UI-1, UI-2 and UI-3 ##STR00541## in which R.sup.U, ##STR00542## X.sup.U1 and X.sup.U2 have the meanings given for formula UI. where in formula UI-3 at least one of ##STR00543## denotes trans-1,4-cyclohexylene, 1,4-cyclohexenylene, tetralin-2,6-diyl, tetralin-5,8-diyl, decalin-2,6-diyl, bicyclo[1.1.1]pentane-1,3-diyl, 4,4′-bicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl, and spiro[3.3]heptane-2,6-diyl, in which one or two CH groups may be replaced by N, one or more non-adjacent CH.sub.2 groups may be replaced by —O— and/or —S— and in which one or more H atoms may be replaced by L, wherein L, on each occurrence, identically or differently, denotes F, Cl, CN, SCN, SF.sub.s or straight-chain or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy each having 1 to 12 C atoms.

3. The compound according to claim 1, wherein X.sup.U1 and X.sup.U2denote F.

4. A liquid crystal medium comprising one or more compounds according to claim 1.

5. The liquid crystal medium according to claim 4, wherein the medium additionally comprises one or more compounds of formula UII ##STR00544## in which R.sup.U denotes H, straight-chain or branched alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms, in which one or more CH.sub.2-groups may be replaced by ##STR00545## where one or more non-adjacent CH.sub.2-groups may be replaced by O, or denotes a group R.sup.P, R.sup.P denotes halogen, CN, NCS, R.sup.F—, R.sup.F—O— or R.sup.F—S—, wherein R.sup.F denotes fluorinated alkyl or fluorinated alkenyl having up to 9 C atoms, Z.sup.U1, Z.sup.U2 identically or differently, denote —CH═CH—, —CF═CF—, —CH═CF—, —CF═CH—, —C═C—, —C—C—C—C— or a single bond, X.sup.U1, X.sup.U2, identically or differently, denote Cl or F, ##STR00546## denote a radical selected from the following groups: a) the group consisting of 1,4-phenylene, 1,4-naphthylene, and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L, b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, tetralin-2,6-diyl, tetralin-5,8-diyl, decalin-2,6-diyl, bicyclo[1.1.1]pentane-1,3-diyl, 4,4′-bicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl, and spiro[3.3]heptane-2,6-diyl, in which one or two CH groups may be replaced by N, one or more non-adjacent CH.sub.2 groups may be replaced by —O— and/or —S— and in which one or more H atoms may be replaced by L, c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may also be mono- or polysubstituted by L, L on each occurrence, identically or differently, denotes F, Cl, CN, SCN, SF.sub.s or straight-chain or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy each having 1 to 12 C atoms, and u is 0, 1 or 2, from which the compounds of formula UI are excluded.

6. The medium according to claim 5, wherein the medium comprises one or more compounds of formula UII selected from the group of the formulae UII-1, UII-2 and UII-3 ##STR00547## in which and R.sup.U, X.sup.U1 and X.sup.U2, ##STR00548## have the meanings given for formula UII.

7. The liquid crystal medium according to claim 4, wherein the medium additionally comprises one or more compounds selected from the group of compounds of the formulae I, II and III: ##STR00549## in which R.sup.1 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, in which one or more CH.sub.2-groups may be replaced by ##STR00550## n is 0, 1 or 2, ##STR00551## on each occurrence, independently of one another, denote ##STR00552## in which R.sup.L, on each occurrence, identically or differently, denotes H or alkyl having 1 to 6 C atoms, ##STR00553## in which one or more H atoms may be replaced by alkyl having 1 to 6 C atoms or F, or ##STR00554## and wherein alternatively denotes ##STR00555## R.sup.2 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, in which one or more CH.sub.2-groups may be replaced by ##STR00556## Z.sup.21 denotes trans-CH═CH—, trans-CF═CF— or —C—C—, and ##STR00557## independently of one another, denote ##STR00558## in which R.sup.L, on each occurrence, identically or differently, denotes H or alkyl having 1 to 6 C atoms, or ##STR00559## in which one or more H atoms may be replaced by alkyl having 1 to 6 C atoms or F, R.sup.3 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, in which one or more CH.sub.2-groups may be replaced by ##STR00560## one of Z.sup.31 and Z.sup.32 denotes trans-CH═CH—, trans-CF═CF— or —C—C— and the other one, independently thereof, denotes —C—C—, trans-CH═CH—, trans-CF═CF— or a single bond, and ##STR00561## independently of one another, denote ##STR00562## in which R.sup.L, on each occurrence, identically or differently, denotes H or alkyl having 1 to 6 C atoms, or ##STR00563## in which one or more H atoms may be replaced by alkyl having 1 to 6 C atoms or F, and wherein ##STR00564## alternatively denotes or ##STR00565##

8. The liquid crystal medium according to claim 7, wherein the medium comprises one or more compounds selected from the group of compounds of the formulae I-1 to I-5 ##STR00566## in which L.sup.1, L.sup.2 and L.sup.3 on each occurrence, identically or differently, denote H or F, and R.sup.1, ##STR00567## have the meanings given for formula I.

9. The liquid crystal medium according to claim 7, wherein the medium comprises one or more compounds selected from the group of compounds of the formulae I-1 to 11-3 ##STR00568## in which R.sup.2, ##STR00569## have the meanings given for formula II.

10. The liquid crystal medium according to claim 4, wherein the medium comprises one or more compounds of formula III selected from the group consisting of the compounds of the formulae III-1 to III-6 ##STR00570## in which Z.sup.31 and Z.sup.32 independently of one another denote trans-CH═CH— or trans-CF═CF—, preferably trans-CH═CH—, and in formula III-6 alternatively one of Z.sup.31 and Z.sup.32 may denote —C≡C—, R.sup.3 denotes unfluorinated alkyl or alkoxy having 1 to 7 C atoms or unfluorinated alkenyl having 2 to 7 C atoms, and one of ##STR00571## denotes ##STR00572## and the others, independently of one another, denote ##STR00573## where ##STR00574## alternatively denotes ##STR00575##

11. The liquid crystal medium according to claim 4, wherein the medium comprises one or more compounds of formula T ##STR00576## in which R.sup.T denotes halogen, CN, NCS, R.sup.F, R.sup.F—O— or R.sup.F—S—, wherein R.sup.F denotes fluorinated alkyl or fluorinated alkenyl having up to 12 C atoms, ##STR00577## on each occurrence, independently of one another, denote ##STR00578## L.sup.4 and L.sup.S identically or differently, denote F, Cl or straight-chain or branched or cyclic alkyl or alkenyl each having up to 12 C atoms; Z.sup.T3, Z.sup.T4 identically or differently, denote —CH═CH—, —CF═CF—, —CH═CF—, —CF═CH—, —C═C— or a single bond, and t is 0 or 1.

12. The liquid crystal medium according to claim 4, wherein the medium comprises one or more compounds of formula U ##STR00579## in which R.sup.U denotes H, alkyl or alkoxy having 1 to 12 C atoms, or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 12 C atoms, in which one or more CH.sub.2-groups may be replaced by or ##STR00580## or denotes a group R.sup.P, R.sup.P denotes halogen, CN, NCS, R.sup.F, R.sup.F—O— or R.sup.F—S—, wherein R.sup.F denotes fluorinated alkyl or fluorinated alkenyl having up to 9 C atoms, Z.sup.U1, Z.sup.U2 identically or differently, denote —CH═CH—, —CF═CF—, —CH═CF—, —CF═CH—, —C═C— or a single bond, X.sup.1, X.sup.2, X.sup.3 and X.sup.4 identically or differently, denote Cl or F, t is 0 or 1, and ##STR00581## denote a radical selected from the following groups: a) the group consisting of 1,4-phenylene, 1,4-naphthylene, and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L, wherein tetrafluoro-1,4-phenylene is excluded, b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, bicyclo[1.1.1]pentane-1,3-diyl, 4,4′-bicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl and spiro[3.3]heptane-2,6-diyl, in which one or more non-adjacent CH.sub.2 groups may be replaced by —O— and/or —S— and in which one or more H atoms may be replaced by F, and c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may also be mono- or polysubstituted by L, wherein L on each occurrence, identically or differently, denotes F, Cl, CN, SCN, SFs or straight-chain or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms.

13. The liquid crystal medium according to claim 12, wherein the medium comprises one or more compounds selected from the group consisting of the compounds of the formulae U-1 to U-11 ##STR00582## ##STR00583## in which L.sup.1, L.sup.2 and L.sup.3 identically or differently, denote H, F, Cl, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl, and R.sup.U, X.sup.1, X.sup.2, X.sup.3 and X.sup.4 have the meanings given for formula U.

14. A component for high-frequency technology, characterised in that it comprises the liquid crystal medium according to claim 4.

15. The component according to claim 14, wherein the component is a liquid-crystal based antenna element, a phase shifter, a tunable filter, a tunable metamaterial structure, a matching network or a varactor.

16. A microwave antenna array, characterised in that it comprises one or more components according to claim 14.

17. A method for the production of a compound of formula UI defined in claim 1, characterised in that a compound of formula N ##STR00584## in which the occurring groups and parameters have the meanings given for formula UI, is reacted with carbon disulfide or with a thionocarbonic acid derivative X—C(═S)—Y, in which X and Y, identically or differently, denote a leaving group.

Description

EXAMPLES

[0603] The following examples illustrate the present invention without limiting it in any way. It is 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.

Synthesis Examples

Abbreviations

[0604] dist. distilled [0605] DABCO 1,4-Diazabicyclo[2.2.2]octane [0606] THE Tetrahydrofuran [0607] MTB ether Methyl-tert-butyl ether [0608] dist. distilled [0609] XPhos 2-Dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl [0610] XPhos Pd G2 Chloro(2-dicyclohexylphosphino-2′,4′,6′-triisopropyl-1,1′-biphenyl)[2-(2′-amino-1,1′-biphenyl)palladium (II)

Synthesis Example 1: 2-[4-(4-Butylcyclohexyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene

Step 1.1: 4-[4-(4-Butylcyclohexyl)phenyl]-3,5-difluoro-aniline

[0611] ##STR00433##

[0612] Bis(dibenzylidene-acetone)palladium(0) (20 mg, 0.04 mmol) and tris-(o-tolyl)phosphine (50 mg, 0.2 mmol) are added to a mixture of [4-(4-butylcyclohexyl)phenyl]boronic acid (CAS 516510-90-0) (4.5 g, 17 mmol) and 3,5-difluoro-4-iodo-aniline (4.3 g, 17 mmol) in acetone (50 ml) under argon atmosphere at 50° C. Aqueous sodium hydroxide (2 N) (17.0 ml, 34 mmol) is slowly added at reflux temperature, and the reaction mixture is heated at reflux temperature overnight. Then it is allowed to cool to room temperature and is quenched with dist. water and hydrochloric acid (2 N) and diluted with MTB ether. The aqueous phase is separated and extracted with MTB ether. The combined organic layers are washed with brine, dried (sodium sulfate) and concentrated in vacuo. The residue is purified by silica gel chromatography (eluent 1-chlorobutane) to give 4-[4-(4-butylcyclohexyl)phenyl]-3,5-difluoro-aniline as a yellow solid.

Step 1.2: 2-[4-(4-Butylcyclohexyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene

[0613] ##STR00434##

[0614] Thiophosgene (1.3 ml, 16 mmol) is slowly added to a solution of 4-[4-(4-butylcyclohexyl)phenyl]-3,5-difluoro-aniline (4.8 g, 12 mmol) and DABCO (4.0 g, 36 mmol) in dichloromethane (60 ml) at 0° C. under argon atmosphere. The reaction mixture is stirred at room temperature overnight. Then it is quenched with dist. water and brine. The aqueous phase is separated and extracted with dichloromethane. The combined organic phases are washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue is purified by silica gel chromatography (eluent heptane) and crystallization (heptane) to give colorless crystals of 2-[4-(4-butylcyclohexyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene.

[0615] Phase sequence K 91 N 160 1.

[0616] Δε=3.01

[0617] Δn=0.2455

[0618] γ.sub.1=525 m Pas

Synthesis Example 2: 2-[4-(4-Butylphenyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene

Step 2.1: 4-[4-(4-Butylphenyl)phenyl]-3,5-difluoro-aniline

[0619] ##STR00435##

[0620] Bis(dibenzylidene-acetone)palladium(0) (20 mg, 0.04 mmol) and tris-(o-tolyl)phosphine (50 mg, 0.2 mmol) are added to a mixture of [4-(4-butylphenyl)phenyl]boronic acid (CAS 145413-17-8; 4.5 g, 17 mmol) and 3,5-difluoro-4-iodo-aniline (4.3 g, 17 mmol) in acetone (50 ml) under argon atmosphere at 50° C. Aqueous sodium hydroxide (2 N) (18.0 ml, 36 mmol) is slowly added at reflux temperature, and the reaction mixture is heated at reflux temperature overnight. Then it is allowed to cool to room temperature and quenched with dist. water and hydrochloric acid (2 N) and diluted with MTB ether. The aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with brine, dried (sodium sulfate) and concentrated in vacuo. The residue is purified by silica gel chromatography (eluent 1-chlorobutane) to give 4-[4-(4-butylphenyl)phenyl]-3,5-difluoro-aniline as a yellow solid.

Step 2.2: 2-[4-(4-Butylphenyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene

[0621] ##STR00436##

[0622] Thiophosgene (1.3 ml, 16 mmol) is slowly added to a solution of 4-[4-(4-butylphenyl)phenyl]-3,5-difluoro-aniline (4.7 g, 14 mmol) and DABCO (4.0 g, 36 mmol) in dichloromethane (60 ml) at 0° C. under argon atmosphere. The reaction mixture is stirred at room temperature overnight. Then it is quenched with dist. water and brine. The aqueous phase is separated and extracted with dichloromethane. The combined organic phases are washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue is purified by silica gel chromatography (eluent heptane) and crystallization (heptane) to give colorless crystals of 2-[4-(4-butylphenyl)phenyl]-1,3-difluoro-5-isothiocyanato-benzene.

[0623] Phase sequence K 114 SmA (98) N 139 I.

[0624] Δε=3.92

[0625] Δn=0.3414

[0626] γ.sub.1=430 mPas

Synthesis Example 3: 2-[2-(4-Butylphenyl)ethynyl]-1,3-difluoro-5-isothiocyanato-benzene

Step 3.1: 4-[2-(4-Butylphenyl)ethynyl]-3,5-difluoro-aniline

[0627] ##STR00437##

[0628] XPhos Pd G2 (40 mg, 0.05 mmol), XPhos (25 mg, 0.05 mmol) and copper(I) iodide (5 mg, 0.03 mmol) are added to a mixture of 1-butyl-4-ethynylbenzene (4.0 g, 25 mmol) and 3,5-difluoro-4-iodo-aniline (6.3 g, 25 mmol) in diisopropylamine (60 ml) and THE (60 ml) under argon atmosphere slightly below the boiling point. The reaction mixture is heated at reflux temperature overnight. Then it is allowed to cool to room temperature, and the precipitate is filtered off and washed with THF. The filtrate is concentrated in vacuo. The residue is purified by silica gel chromatography (eluent 1-chlorobutane) to give 4-[2-(4-butylphenyl)ethynyl]-3,5-difluoro-aniline (3) as a brown oil.

Step 3.2: 2-[2-(4-Butylphenyl)ethynyl]-1,3-difluoro-5-isothiocyanato-benzene

[0629] ##STR00438##

[0630] Thiophosgene (1.9 ml, 24 mmol) is slowly added to a solution of 4-[2-(4-butylphenyl)ethynyl]-3,5-difluoro-aniline (6.1 g, 20 mmol) and DABCO (6.0 g, 53 mmol) in dichloromethane (100 ml) at 0° C. under argon atmosphere, and the reaction mixture is stirred at room temperature for 1 h. Then it is quenched with dist. water and brine. The aqueous phase is separated and extracted with dichloromethane. The combined organic phases are washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue is purified by silica gel chromatography (eluent heptane) and crystallization (heptane) to give colorless crystals of 2-[2-(4-butylphenyl)ethynyl]-1,3-difluoro-5-isothiocyanato-benzene.

[0631] Phase sequence: K 44 N (29) 1.

[0632] Δε=3.70

[0633] Δn=0.3690

[0634] γ.sub.1=53 m Pas

Synthesis Example 4:1,3-Difluoro-5-isothiocyanato-2-[4-[4-(trifluoromethoxy)-phenyl]phenyl]benzene

Step 4.1: 3,5-Difluoro-4-[4-[4-(trifluoromethoxy)phenyl]phenyl]aniline

[0635] ##STR00439##

[0636] Bis(dibenzylidene-acetone)palladium(0) (20 mg, 0.04 mmol) and tris-(o-tolyl)phosphine (45 mg, 0.1 mmol) are added to a mixture of [4-(4-(trifluoromethoxy)phenyl]phenyl]-boronic acid (CAS 501944-50-9) (4.0 g, 14 mmol) and 4-bromo-3,5-difluoro-aniline (3.0 g, 14 mmol) in acetone (40 ml) at 50° C. under argon atmosphere. Aqueous sodium hydroxide (2 N) (15 ml, 30 mmol) is slowly added at reflux temperature, and the reaction mixture is heated at reflux temperature overnight. Then it is allowed to cool to room temperature and quenched with dist. water and diluted with MTB ether. The aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with brine, dried (sodium sulfate) and concentrated in vacuo. The residue is purified by silica gel chromatography (eluent 1-chlorobutane) to give 3,5-difluoro-4-[4-[4-(trifluoromethoxy)phenyl]phenyl]aniline as a yellow solid.

Step 4.2: 1,3-Difluoro-5-isothiocyanato-2-[4-[4-(trifluoromethoxy)phenyl]phenyl]-benzene

[0637] ##STR00440##

[0638] Thiophosgene (1.0 ml, 13 mmol) is slowly added to a solution of 3,5-difluoro-4-[4-[4-(trifluoromethoxy)phenyl]phenyl]aniline (3.9 g, 11 mmol) and DABCO (3.0 g, 27 mmol) in dichloromethane (50 ml) at 0° C. under argon atmosphere. The reaction mixture is stirred at room temperature overnight. Then it is quenched with dist. water and brine. The aqueous phase is separated and extracted with dichloromethane. The combined organic phases are washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue is purified by silica gel chromatography (eluent heptane) and crystallization (heptane) to give white crystals of 1,3-difluoro-5-isothiocyanato-2-[4-[4-(trifluoromethoxy)phenyl]phenyl]benzene.

[0639] Phase sequence K 135 N (128) 1.

[0640] Δε=3.47

[0641] Δn=0.3212

[0642] In analogy to Synthesis Examples 1 to 4 the following compounds are obtained:

TABLE-US-00008 physical No. Compound properties 5 [00441] 6 [00442] 7 [00443] 8 [00444] 9 [00445] 10 [00446] 11 [00447] 12 [00448] 13 [00449] 14 [00450] 15 [00451] K 59 I Δε = 4.32 Δn = 0.3956 γ.sub.1 = 37 mPas 16 [00452] K 75 I Δε = 2.52 Δn = 0.4026 γ.sub.1 = 51 mPas 17 [00453] K 82 I Δε = 3.72 Δn = 0.3732 γ.sub.1 = 58 mPas 18 [00454] K 63 N (36) I Δε = 3.12 Δn = 0.3489 γ.sub.1 = 61 mPas 19 [00455] 20 [00456] 21 [00457] 22 [00458] 23 [00459] 24 [00460] 25 [00461] 26 [00462] 27 [00463] 28 [00464] 29 [00465] 30 [00466] 31 [00467] K 116 N 163.2 I Δε = 3.12 Δn = 0.2646 γ.sub.1 = 493 mPas 32 [00468] K 94 N 163.9 I Δε = 3.32 Δn = 0.2460 γ.sub.1 = 678 mPas 33 [00469] 34 [00470] 35 [00471] 36 [00472] 37 [00473] 38 [00474] 39 [00475] 40 [00476] 41 [00477] 42 [00478] 43 [00479] 44 [00480] 45 [00481] 46 [00482] 47 [00483] 48 [00484] 49 [00485] 50 [00486] 51 [00487] 52 [00488] 53 [00489] 54 [00490] 55 [00491] 56 [00492] 57 [00493] 58 [00494] 59 [00495] 60 [00496] 61 [00497] 62 [00498] 63 [00499] 64 [00500] 65 [00501]

[0643] Preferred compounds of formula UII are prepared as follows

Synthesis of Reference Example 1: 2-[4-[2-(4-Butylphenyl)ethynyl]phenyl]-1,3-difluoro-5-isothiocyanato-benzene

Step 1.1: 2-[4-[2-(4-Butylphenyl)ethynyl]phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

[0644] ##STR00502##

[0645] XPhos Pd G2 (170 mg, 0.2 mmol), XPhos (100 mg, 0.2 mmol) and copper(I) iodide (20 mg, 0.1 mmol) are added to a mixture of 1-butyl-4-ethynylbenzene (18.0 g, 0.1 mol) and 2-(4-bromophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (30.0 g, 0.1 mol) in diisopropylamine (250 ml) and THE (27 ml) under argon atmosphere at 55° C. The reaction mixture is heated at reflux temperature overnight. Then it is allowed to cool to room temperature, filtered and concentrated in vacuo. The residue is dissolved in toluene, washed with dist. water, dried (sodium sulfate), filtered and concentrated in vacuo. The crude product is purified by silica gel chromatography (eluent toluene) and crystallization (heptane) to give 2-[4-[2-(4-butylphenyl)ethynyl]phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane as yellow crystals.

Step 1.2: 4-[4-[2-(4-Butylphenyl)ethynyl]phenyl]-3,5-difluoro-aniline

[0646] ##STR00503##

[0647] Bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II) (7 mg, 0.01 mmol) is added to a mixture of 2-[4-[2-(4-butylphenyl)ethynyl]phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.5 g, 10 mmol) and 4-bromo-3,5-difluoro-aniline (2.0 g, 10 mmol) in ethylene glycol (20 ml) and THE (20 ml) at 60° C. under argon atmosphere. Aqueous sodium hydroxide (2 N) (7.5 ml, 15 mmol) is slowly added at reflux temperature, and the reaction mixture is heated at reflux temperature overnight.

[0648] Then it is allowed to cool to room temperature and quenched with acetic acid (0.9 ml, 16 mmol) and dist. water. MTB ether is added, and the aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue is purified by silica gel chromatography (eluent dichloromethane) to give 4-[4-[2-(4-butylphenyl)ethynyl]phenyl]-3,5-difluoro-aniline as a yellow solid.

Step 1.3: 2-[4-[2-(4-Butylphenyl)ethynyl]phenyl]-1,3-difluoro-5-isothiocyanato-benzene

[0649] ##STR00504##

[0650] Thiophosgene (0.7 ml, 9 mmol) is slowly added to a solution of 4-[4-[2-(4-butylphenyl)ethynyl]phenyl]-3,5-difluoro-aniline (2.9 g, 8 mmol) and DABCO (2.3 g, 21 mmol) in dichloromethane (40 ml) at 0° C. under argon atmosphere. The reaction mixture is stirred at room temperature for 1 h. Then it is quenched with dist. water and brine. The aqueous phase is separated and extracted with dichloromethane. The combined organic phases are washed with brine, dried (sodium sulfate), filtered and concentrated in vacuo. The residue is purified by silica gel chromatography (eluent heptane) and crystallization (heptane) to give colorless crystals of 2-[4-[2-(4-butylphenyl)ethynyl]phenyl]-1,3-difluoro-5-isothiocyanato-benzene.

[0651] Phase sequence K 120 N 178 I.

[0652] Δε=4.92

[0653] Δn=0.4369

[0654] γ.sub.1=697 m Pas

[0655] In analogy to Reference Example 1, the following compounds are obtained:

TABLE-US-00009 2 [00505] 3 [00506] 4 [00507] K 82 SmA 138 N 227.1 I Δε = 6.32 Δn = 0.5069 γ.sub.1 = 385 mPas 5 [00508] K 85 SmA 155.5 N 222.8 I Δε = 4.52 Δn = 0.4939 6 [00509] 7 [00510] 8 [00511] 9 [00512] 10 [00513] 11 [00514] 12 [00515] 13 [00516] 14 [00517] 15 [00518] 16 [00519] 17 [00520] K 79 SmX 98 N 191.3 I Δε = 4.04 Δn = 0.4487 18 [00521] 19 [00522] 20 [00523] 21 [00524] 22 [00525] 23 [00526] 24 [00527] 25 [00528] 26 [00529] 27 [00530] 28 [00531] 29 [00532] 30 [00533] 31 [00534] 32 [00535] 33 [00536]

[0656] Mixture Examples

[0657] Comparative examples C1, C2 and Mixture Examples M1 to M13 are prepared and investigated as described below.

Comparative Example C1

[0658]

TABLE-US-00010 PPTU-4-S 6.0 T(N,I) [° C.]: 159 PPTU-5-S 15.0 Δε [1 kHz, 20° C.]: 15.1 PPU-TO-S 16.0 ε.sub.|| [1 kHz, 20° C.]: 18.7 CPTU-5-S 25.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.6 PTU-3-S 10.0 γ.sub.1 [mPa s, 20° C.]: 505 PTU-5-S 10.0 K.sub.1 [pN, 20° C.]: 17.7 CPU(F,F)-3-S 18.0 K.sub.3 [pN, 20° C.]: 24.7 Σ 100.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.39 V.sub.0 [V, 20° C.]: 1.14 LTS bulk [h, −40° C.]: 936 τ [20° C., 19 GHz]: 0.326 ε.sub.r,|| [20° C., 19 GHz]: 3.57 ε.sub.r,⊥ [20° C., 19 GHz]: 2.40 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0050 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0083 η [20° C., 19 GHz]: 39.3

TABLE-US-00011 PPTU-4-S 6.0 T(N,I) [° C.]: 159.5 PPTU-5-S 12.0 Δε [1 kHz, 20° C.]: 12.4 PPU-TO-S 8.0 ε.sub.|| [1 kHz, 20° C.]: 15.7 CPTU-5-S 25.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.3 PTU-5-S 7.0 γ.sub.1 [mPa s, 20° C.]: 435 CPU(F,F)-3-S 18.0 K.sub.1 [pN, 20° C.]: 18.9 PTPUI-4-S 4.0 K.sub.3 [pN, 20° C.]: 21.5 PPTUI-4-S 6.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.14 PTUI-4-S 14.0 V.sub.0 [V, 20° C.]: 1.33 Σ 100.0 τ [20° C., 19 GHz]: 0.334 ε.sub.r,|| [20° C., 19 GHz]: 3.60 ε.sub.r,⊥ [20° C., 19 GHz]: 2.40 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0049 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0071 η [20° C., 19 GHz]: 47.4

[0659] Mixture Example M1 differs from Comparative Example C in that it additionally comprises the compounds PTPUI-4-S, PPTUI-4-S and PTUI-4-S. As a result, the medium M1 shows an improved figure-of-merit rt due to a higher tunability ti and lower loss tan δ.sub.εr,⊥.

Comparative Mixture C2

[0660]

TABLE-US-00012 PPTU-4-S 10.0 T(N,I) [° C.]: 131 PPTU-5-S 20.0 Δε [1 kHz, 20° C.]: 10.4 CPTU-5-S 10.0 ε.sub.|| [1 kHz, 20° C.]: 13.5 PTU-5-S 10.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.2 PTP(2)TP-6-3 50.0 K.sub.1 [pN, 20° C.]: 22.0 Σ 100.0 K.sub.3 [pN, 20° C.]: 28.9 K.sub.3/K.sub.1 [pN, 20° C.]: 1.32 V.sub.0 [V, 20° C.]: 1.54 τ [20° C., 19 GHz]: 0.309 ε.sub.r,|| [20° C., 19 GHz]: 3.49 ε.sub.r,⊥ [20° C., 19 GHz]: 2.41 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0038 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0073 η [20° C., 19 GHz]: 42.3

Mixture Example M2

[0661]

TABLE-US-00013 PPTU-4-S 10.0 T(N,I) [° C.]: 129.5 PPTU-5-S 20.0 Δε [1 kHz, 20° C.]: 8.7 CPTU-5-S 10.0 ε.sub.|| [1 kHz, 20° C.]: 11.7 PTUI-4-S 10.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.0 PTP(2)TP-6-3 50.0 K.sub.1 [pN, 20° C.]: 19.5 Σ 100.0 K.sub.3 [pN, 20° C.]: 21.4 K.sub.3/K.sub.1 [pN, 20° C.]: 1.10 V.sub.0 [V, 20° C.]: 1.58 τ [20° C., 19 GHz]: 0.310 ε.sub.r,|| [20° C., 19 GHz]: 3.49 ε.sub.r,⊥ [20° C., 19 GHz]: 2.41 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0037 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0067 η [20° C., 19 GHz]: 46.2

[0662] Mixture Example M2 differs from Comparative Example C2 in that it additionally comprises the compounds PTUI-4-S. As a result, the medium M2 shows an improved figure-of-merit rt due to a lower loss tan δ.sub.ε r,⊥.

Mixture Example M3

[0663]

TABLE-US-00014 CPTU-5-S 23.5 T(N,I) [° C.]: 173.5 CPU(F,F)-3-S 19.0 τ [20° C., 19 GHz]: 0.299 CPUI-4-S 12.5 ε.sub.r,|| [20° C., 19 GHz]: 3.46 PTUI-4-S 10.0 ε.sub.r,⊥ [20° C., 19 GHz]: 2.43 UIPTU-5-S 15.0 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0043 PPTUI-4-S 20.0 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0048 Σ 99.00 η [20° C., 19 GHz]: 62.9

Mixture Example M4

[0664]

TABLE-US-00015 PPTU-4-S 10.0 T(N,I) [° C.]: 166.5 PPTU-5-S 20.0 Δε [1 kHz, 20° C.]: 17.7 CPTU-5-S 20.0 ε.sub.|| [1 kHz, 20° C.]: 21.3 PGTU-4-S 10.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.6 PGU-3-S 10.0 γ.sub.1 [mPa s, 20° C.]: 451 PPTU-TO-S 10.0 K.sub.1 [pN, 20° C.]: 23.3 PTUI-4-S 20.0 K.sub.3 [pN, 20° C.]: 22.8 Σ 100.0 K.sub.3/K.sub.1 [pN, 20° C.]: 0.98 V.sub.0 [V, 20° C.]: 1.21 τ [20° C., 19 GHz]: 0.354 ε.sub.r,|| [20° C., 19 GHz]: 3.79 ε.sub.r,⊥ [20° C., 19 GHz]: 2.45 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0054 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0095 η [20° C., 19 GHz]: 37.4

Mixture Example M5

[0665]

TABLE-US-00016 PPTU-4-S 6.0 T(N,I) [° C.]: 159 PPTU-5-S 10.0 Δε [1 kHz, 20° C.]: 14.4 PGTU-4-S 6.0 ε.sub.|| [1 kHz, 20° C.]: 17.9 PGU-3-S 12.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.6 PPU-TO-S 23.0 γ.sub.1 [mPa s, 20° C.]: 430 CPTU-5-S 22.0 K.sub.1 [pN, 20° C.]: 19.0 PTUI-4-S 21.0 K.sub.3 [pN, 20° C.]: 22.9 Σ 100.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.21 V.sub.0 [V, 20° C.]: 1.21 LTS bulk [h, −30° C.]: 1000 ε.sub.r,|| [20° C., 19 GHz]: 3.72 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0062 ε.sub.r,⊥ [20° C., 19 GHz]: 2.46 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0100 τ [20° C., 19 GHz]: 0.339 η [20° C., 19 GHz]: 34.0

Mixture Example M6

[0666]

TABLE-US-00017 PPTU-4-S 6.0 T(N,I) [° C.]: 160.5 PPTU-5-S 12.0 Δε [1 kHz, 20° C.]: 16.6 PGTU-4-S 6.0 ε.sub.|| [1 kHz, 20° C.]: 20.1 PGU-3-S 10.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.6 CPTU-5-S 10.0 γ.sub.1 [mPa s, 20° C.]: 568 PPU-TO-S 10.0 K.sub.1 [pN, 20° C.]: 22.7 PTUI-4-S 16.0 K.sub.3 [pN, 20° C.]: 24.4 CPU(F,F)-3-S 10.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.08 PPTU-4(1.sup.2)-S 20.0 V.sub.0 [V, 20° C.]: 1.24 Σ 100.0 ε.sub.r,|| [20° C., 19 GHz]: 3.73 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0050 ε.sub.r,⊥ [20° C., 19 GHz]: 2.45 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0082 τ [20° C., 19 GHz]: 0.344 η [20° C., 19 GHz]: 41.9

Mixture Example M7

[0667]

TABLE-US-00018 PPTU-4-S 6.0 T(N,I) [° C.]: 159.5 PPTU-5-S 10.0 Δε [1 kHz, 20° C.]: 14.7 PGTU-4-S 6.0 ε.sub.|| [1 kHz, 20° C.]: 18.3 PGU-3-S 12.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.6 PPU-TO-S 23.0 γ.sub.1 [mPa s, 20° C.]: 415 CPTU-5-S 22.0 K.sub.1 [pN, 20° C.]: 18.9 PTUI-2-S 11.0 K.sub.3 [pN, 20° C.]: 23.6 PTUI-4-S 10.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.25 Σ 100.0 V.sub.0 [V, 20° C.]: 1.20 LTS bulk [h, −30° C.]: 1000 ε.sub.r,|| [20° C., 19 GHz]: 3.72 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0062 ε.sub.r,⊥ [20° C., 19 GHz]: 2.44 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0099 τ [20° C., 19 GHz]: 0.344 η [20° C., 19 GHz]: 34.9

Mixture Example M8

[0668]

TABLE-US-00019 PPTU-4-S 6.0 T(N,I) [° C.]: 145.5 PPTU-5-S 12.0 Δε [1 kHz, 20° C.]: 14.2 PGTU-4-S 6.0 ε.sub.|| [1 kHz, 20° C.]: 17.9 PGU-3-S 16.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.6 PPU-TO-S 26.0 γ.sub.1 [mPa s, 20° C.]: 364 CPTU-5-S 8.0 K.sub.1 [pN, 20° C.]: 18.8 PTUI-2-S 13.0 K.sub.3 [pN, 20° C.]: 20.9 PTUI-4-S 13.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.11 Σ 100.0 V.sub.0 [V, 20° C.]: 1.21 ε.sub.r,|| [20° C., 19 GHz]: 3.77 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0067 ε.sub.r,⊥ [20° C., 19 GHz]: 2.46 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0106 τ [20° C., 19 GHz]: 0.348 η [20° C., 19 GHz]: 32.8

Mixture Example M9

[0669]

TABLE-US-00020 PPTU-4-S 6.0 T(N,I) [° C.]: 154.5 PPTU-5-S 12.0 Δε [1 kHz, 20° C.]: 14.8 PGTU-4-S 6.0 ε.sub.|| [1 kHz, 20° C.]: 18.4 PGU-3-S 16.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.7 PPU-TO-S 26.0 γ.sub.1 [mPa s, 20° C.]: 400 CPTU-5-S 12.0 K.sub.1 [pN, 20° C.]: 19.1 PTUI-2-S 12.0 K.sub.3 [pN, 20° C.]: 23.0 PTUI-4-S 10.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.20 Σ 100.0 V.sub.0 [V, 20° C.]: 1.20 ε.sub.r,|| [20° C., 19 GHz]: 3.82 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0065 ε.sub.r,⊥ [20° C., 19 GHz]: 2.52 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0106 τ [20° C., 19 GHz]: 0.341 η [20° C., 19 GHz]: 32.2

Mixture Example M10

[0670]

TABLE-US-00021 PPTU-4-S 6.0 T(N,I) [° C.]: 160 PPTU-5-S 15.0 Δε [1 kHz, 20° C.]: 14.3 PGU-3-S 12.0 ε.sub.|| [1 kHz, 20° C.]: 17.8 PPU-TO-S 23.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.5 CPTU-5-S 23.0 γ.sub.1 [mPa s, 20° C.]: 427 PTUI-2-S 11.0 K.sub.1 [pN, 20° C.]: 19.3 PTUI-4-S 10.0 K.sub.3 [pN, 20° C.]: 24.2 Σ 100.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.26 V.sub.0 [V, 20° C.]: 1.23 ε.sub.r,|| [20° C., 19 GHz]: 3.75 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0060 ε.sub.r,⊥ [20° C., 19 GHz]: 2.47 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0095 τ [20° C., 19 GHz]: 0.341 η [20° C., 19 GHz]: 36.1

Mixture Example M11

[0671]

TABLE-US-00022 PGU-3-S 6.0 T(N,I) [° C.]: 154 PPTU-4-S 6.0 Δε [1 kHz, 20° C.]: 12.3 PPTU-5-S 12.0 ε.sub.|| [1 kHz, 20° C.]: 15.6 PPU-TO-S 22.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.4 CPTU-5-S 23.0 γ.sub.1 [mPa s, 20° C.]: 403 CPU(F,F)-3-S 7.0 K.sub.1 [pN, 20° C.]: 18.2 PTUI-2-S 12.0 K.sub.3 [pN, 20° C.]: 23.1 PTUI-4-S 12.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.27 Σ 100.0 V.sub.0 [V, 20° C.]: 1.29 ε.sub.r,|| [20° C., 19 GHz]: 3.70 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0059 ε.sub.r,⊥ [20° C., 19 GHz]: 2.45 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0086 τ [20° C., 19 GHz]: 0.338 η [20° C., 19 GHz]: 39.3

Mixture Example M12

[0672]

TABLE-US-00023 PPTU-4-S 6.0 T(N,I) [° C.]: 160 PPTU-5-S 15.0 Δε [1 kHz, 20° C.]: 11.7 PPU-TO-S 15.0 ε.sub.|| [1 kHz, 20° C.]: 15.0 CPTU-5-S 25.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.3 CPU(F,F)-3-S 18.0 γ.sub.1 [mPa s, 20° C.]: 442 PTUI-2-S 10.0 K.sub.1 [pN, 20° C.]: 18.7 PTUI-4-S 11.0 K.sub.3 [pN, 20° C.]: 23.4 Σ 100.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.25 V.sub.0 [V, 20° C.]: 1.33 LTS bulk [h, −30° C.]: 816 ε.sub.r,|| [20° C., 19 GHz]: 3.64 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0052 ε.sub.r,⊥ [20° C., 19 GHz]: 2.43 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0073 τ [20° C., 19 GHz]: 0.333 η [20° C., 19 GHz]: 45.9

Mixture Example M13

[0673]

TABLE-US-00024 PPTU-4-S 6.0 T(N,I) [° C.]: 156 PPTU-5-S 15.0 Δε [1 kHz, 20° C.]: 11.8 PPU-TO-S 12.0 ε.sub.|| [1 kHz, 20° C.]: 15.1 CPTU-5-S 25.0 ε.sub.⊥ [1 kHz, 20° C.]: 3.3 CPU(F,F)-3-S 18.0 γ.sub.1 [mPa s, 20° C.]: 409 PTUI-2-S 12.0 K.sub.1 [pN, 20° C.]: 18.3 PTUI-4-S 12.0 K.sub.3 [pN, 20° C.]: 23.2 Σ 100.0 K.sub.3/K.sub.1 [pN, 20° C.]: 1.26 V.sub.0 [V, 20° C.]: 1.31 LTS bulk [h, −30° C.]: 1000 ε.sub.r,|| [20° C., 19 GHz]: 3.65 tan δ.sub.ε r,|| [20° C., 19 GHz]: 0.0052 ε.sub.r,⊥ [20° C., 19 GHz]: 2.44 tan δ.sub.ε r,⊥ [20° C., 19 GHz]: 0.0073 τ [20° C., 19 GHz]: 0.332 η [20° C., 19 GHz]: 45.8