Dichroic dye composition

1. A liquid-crystalline medium comprising:

two or more compounds of formula I

and two or more compounds of formula II

wherein

R 1 on each occurrence, identically or differently, denotes H, F, CN, N(R z ) 2 , Si(R z ) 3 , or a straight-chain having 1 to 20 C atoms or branched alkyl or alkoxy having 3 to 20 C atoms, in which, in addition, one or more non-adjacent CH 2 groups may each be replaced, independently of one another, by —C(R z )═C(R z )—, —C≡C—,

—N(R z )—, —O—, —S—, —CO—, —CO—O—, —O—CO— or —O—CO—O— in such a way that O and/or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may each be replaced by F or CN,

X on each occurrence, identically or differently, denotes CR a or N,

R a on each occurrence, identically or differently, denotes H, straight-chain alkyl having 1 to 12 C atoms, branched alkyl having 3 to 12 C atoms, F, Cl, N(R z ) 2 or CN,

R 2 and R z on each occurrence, identically or differently, denote H, halogen, or straight-chain alkyl having 1 to 12 C atoms, branched alkyl having 3 to 12 C atoms, or cyclic alkyl having 3 to 12 C atoms, in which, in addition, one or more non-adjacent CH 2 groups may each be replaced by —O—, —S—, —CO—, —CO—O—, —O—CO— or —O—CO—O— in such a way that O and/or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may each be replaced by F or Cl,

Ar 1 and Ar 2 on each occurrence, identically or differently, denote an aryl or heteroaryl group, which may be substituted by one or more radicals L,

L on each occurrence, identically or differently, denotes F, Cl, CN, OH, SCN, SF 5 , N(R z ) 2 , straight-chain, optionally fluorinated, alkyl or alkoxy having 1 to 12 C atoms, branched, optionally fluorinated, alkyl or alkoxy having 3 to 12 C atoms, straight-chain alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, optionally fluorinated, having 2 to 12 C atoms, or branched alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, optionally fluorinated, having 4 to 12 C atoms

Z 1 on each occurrence, identically or differently, denotes a single bond, —O—, —S—, —C(O)—, —CR y1 R y2 —, —CF 2 O—, —OCF 2 —, —C(O)—O—, —O—C(O)—, —OCH 2 —, —CH 2 O—, —CR x1 ═CR x2 —, —C≡C—, —CR x1 ═CR x2 —CO—, —CO—CR x1 ═CR x2 —, —CR x1 ═CR x2 —COO—, —OCO—CR x1 ═CR x2 — or —N═N—,

Z 2 on each occurrence, identically or differently, denotes a single bond, —CF 2 O—, —OCF 2 — or —C≡C—,

a, b, c and d independently of one another, denote 0 or 1,

R x1 , R x2 independently of one another, denote H, F, Cl, CN or alkyl having 1 to 12 C atoms,

R y1 denotes H or alkyl having 1 to 12 C atoms, and

R y2 denotes alkyl having 1 to 12 C atoms, and

one or more mesogenic compounds,

wherein the composition comprises at least one purple dye, at least one blue dye, at least one yellow dye, at least one red dye and at least one near-infrared dye.

2. The liquid-crystalline medium according to claim 1 , wherein Ar 1 and Ar 2 denote, independently of one another, 1,4-phenylene, 1,4-naphthylene, 2,6-naphthylene, thiazole-2,5-diyl, thiophene-2,5-diyl or thienothiophene-2,5-diyl, wherein one or more H atoms may be replaced by the group L as defined in claim 1 .

3. The liquid-crystalline medium according to claim 1 , wherein at least one of Ar 1 is thiophene-2,5-diyl or thienothiophene-2,5-diyl.

4. The liquid-crystalline medium according to claim 1 , wherein

R 1 identically or differently, denotes a straight-chain alkyl or alkoxy having 1 to 15 C atoms, branched alkyl or alkoxy having 3 to 15 C atoms, or N(R b ) 2 ,

R b is, independently of one another, a straight-chain alkyl having 1 to 9 C atoms, R 2 identically or differently, denotes a straight-chain alkyl having 1 to 9 C atoms,

a, b, c, and d each denote 1,

Z 1 is a single bond, and

Z 2 is a single bond.

5. The liquid-crystalline medium according to claim 1 , wherein at least one of said two or more compounds of formula I is selected from the compounds of formulae I-1, I-2, I-3, and I-4

and at least one of said two or more compounds of formula II

is selected from the compounds of formulae II-1, II-2, II-3, II-4, and II-5

6. The liquid-crystalline medium according to claim 1 , wherein the medium comprises one or more compounds selected from the group of compounds of formulae CY, PY, and AC

wherein

denotes

denote

denotes

R 1 , R 2 ,

R AC1 , R AC2 each, independently of one another, denote alkyl having 1 to 12 C atoms, where, in addition, one or two non-adjacent CH 2 groups may each be replaced by —O—, —CH═CH—, —CO—, —OCO— or —COO— in such a way that O atoms are not linked directly to one another,

Z x , Z y , Z AC each, independently of one another, denote —CH 2 CH 2 —, —CH═CH—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CO—O—, —O—CO—, —C 2 F 4 —, —CF═CF—, —CH═CH—CH 2 O— or a single bond,

L 1 , L 2 , L 3 , L 4 each, independently of one another, denote F, Cl, CN, OCF 3 , CF 3 , CH 3 , CH 2 F, or CHF 2 ,

a is 1 or 2,

b is 0 or 1,

c is 0, 1 or 2, and

d is 0 or 1.

7. The liquid-crystalline medium according to claim 1 , wherein the medium comprises one or more compounds selected from the group of compounds of formulae IIA to VIII

wherein

each, independently of one another, denote

identically or differently, denotes a halogenated or unsubstituted alkyl or alkoxy radical having 1 to 15 C atoms, where, in addition, one or more CH 2 groups in these radicals may each be replaced, independently of one another, by —C≡C—, —CF 2 O—, —CH═CH—,

—O—, —CO—O— or —O—CO— in such a way that O atoms are not linked directly to one another,

X 20 identically or differently, denotes F, Cl, CN, SF 5 , SCN, NCS, a halogenated alkyl radical having 1 to 6 C atoms, a halogenated alkenyl radical having 2 to 6 C atoms, a halogenated alkoxy radical having 1 to 6 C atoms, or a halogenated alkenyloxy radical having 2 to 6 C atoms, and

Y 20 , Y 21 , Y 22 , Y 23 , Y 24 each, identically or differently, denote H or F,

Z 20 denotes —C 2 H 4 —, —(CH 2 ) 4 —, —CH═CH—, —CF═CF—, —C 2 F 4 —, —CH 2 CF 2 —, —CF 2 CH 2 —, —CH 2 O—, —OCH 2 —, —COO— or —OCF 2 —, and, in formulae V to VIII, Z 20 can also be —CF 2 O—,

r denotes 0 or 1, and

s denotes 0 or 1.

8. The liquid-crystalline medium according to claim 1 , wherein the medium additionally comprises one or more compounds selected from the group of compounds of formulae DK and O

wherein

R 5 , R 6 , R O1

and R O2 each, independently of one another, denote alkyl having 1 to 12 C atoms, where, in addition, one or two non-adjacent CH 2 groups may each be replaced by —O—, —CH═CH—, —CO—, —OCO— or —COO— in such a way that O atoms are not linked directly to one another,

denotes

denotes

denotes

denotes

Z O1 denotes —CH 2 CH 2 —, —CF 2 CF 2 —, —C═C—, or a single bond,

Z O2 denotes CH 2 O, —C(O)O—, —CH 2 CH 2 —, —CF 2 CF 2 —, or a single bond,

o is 1 or 2, and

e is 1 or 2.

9. The liquid-crystalline medium according to claim 1 , wherein the medium additionally comprises one or more compounds selected from the group of compounds of formulae O3 to O5

wherein R O1 and R O2 , identically or differently, denote straight-chain alkyl having 1 to 6 C atoms or straight-chain alkenyl having 2 to 6 C atoms.

10. The liquid-crystalline medium according to claim 1 , wherein the medium additionally comprises one or more compounds selected from the group of compounds of formulae DK1 to DK12:

in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, and alkenyl denotes a straight-chain alkenyl radical having 2 to 6 C atoms.

11. A device for regulating the passage of energy from an outside space into an inside space, said device comprising a switching layer that contains a liquid-crystalline medium according to claim 1 .

12. A window comprising the device according to claim 11 .

13. An architectural window or a car sunroof, comprising a liquid crystalline medium according to claim 1 .

14. The liquid-crystalline medium according to claim 1 , wherein at least one of Ar 1 is thiophene-2,5-diyl.

15. The liquid-crystalline medium according to claim 1 , wherein

R 1 identically or differently, denotes a branched, alkyl or alkoxy having 3 to 15 C atoms or N(R b ) 2 ,

R b is, independently of one another, ethyl, butyl, or hexyl,

R 2 identically or differently, denotes ethyl,

a, b, c, and d each denote 1,

Z 1 is a single bond, and

Z 2 is a single bond.

16. The liquid-crystalline medium according to claim 5 , wherein the composition contains two or more compounds selected from the compounds of formulae I-1, I-2, I-3, and I-4, and two or more compounds selected from the compounds of formulae II-1, II-2, II-3, II-4, and II-5.

17. The liquid-crystalline medium according to claim 5 , wherein at least one of said two or more compounds of formula I is a compound of formula I-1 and at least one of said two or more compounds of formula II is a compound of formulae II-1.

18. The liquid-crystalline medium according to claim 1 , wherein each compound of formula I is present in said medium in an amount of 0.005% by weight to 12.5% by weight, and each compound of formula II is present in said medium in an amount of 0.005% by weight to 12.5% by weight.

19. The liquid-crystalline medium according to claim 1 , wherein the total concentration of compounds of formula I and compounds of formula II in said medium is 0.01% by weight to 30% by weight.

20. The liquid-crystalline medium according to claim 5 , wherein at least one of said two or more compounds of formula I is a compound of formula I-1, and said two or more compounds of formula II includes a compound of formulae II-1 and a compound of formulae II-4.

21. The liquid-crystalline medium according to claim 5 , wherein said two or more compounds of formula I includes a compound of formula I-1 and a compound of formula I-2, and said two or more compounds of formula II includes a compound of formulae II-1 and a compound of formulae II-4.