Thiophene compound, liquid-crystalline medium and liquid-crystal display comprising the same

1. A liquid-crystalline medium comprising one or more compounds of formula T

in which

denotes

and each

independently of each other, denotes

wherein the rings

optionally may each be substituted with one or two alkyl groups,

n denotes 1 or 2,

R 5 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy, wherein one —CH 2 — group may be replaced by cyclopropylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, cyclopentylene, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, wherein one —CH 2 — group may be replaced by cyclopropylene, 1,3-cyclobutylene, 1,3-cyclopentylene, 1,3-cyclo-pentenylene, and

X 5 denotes F, Cl, CN, NCS fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy or fluorinated alkenyloxy,

at least one or more compounds of formula IV-1 and/or IV-2

alkyl and alkyl′, independently of one another, denote alkyl having 1 to 7 C atoms,

alkenyl denotes an alkenyl radical having 2 to 5 C atoms,

and

a compound of formula II-2

in which

L 21 and L 22 denote independently of each other H or F,

L 23 and L 24 independently of one another denote H or F,

R 2 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, or alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms,

are each independently

and

X 2 denotes halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms.

2. The liquid-crystalline medium according to claim 1 , comprising one or more compounds T of formulae T-1 and/or T-2:

in which

R S denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, and

X S denotes F, Cl, CN, NCS, fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy or fluorinated alkenyloxy.

3. The liquid-crystalline medium according to claim 2 , comprising one or more compounds of formula T-1.

4. The liquid-crystalline medium according to claim 1 , further comprising one or more compounds of formula III:

in which

R 3 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms

on each appearance, independently of one another, are

L 31 and L 32 , independently of one another, denote H or F,

X 3 denotes halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms, F, Cl, —OCF 3 , —OCHF 2 , —O—CH 2 CF 3 , —O—CH═CF 2 , —O—CH═CH 2 or —CF 3 ,

Z 3 denotes —CH 2 CH 2 —, —CF 2 CF 2 —, —COO—, trans-CH═CH—, trans-CF═CF—, —CH 2 O— or a single bond, and

n denotes 0, 1, 2 or 3.

5. The liquid-crystalline medium according to claim 1 , further comprising one or more compounds of formula V:

in which

R 51 and R 52 , independently of one another, are alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms,

if present, each, independently of one another, denote

Z 51 to Z 53 each, independently of one another, denote —CH 2 —CH 2 —, —CH 2 —O—, —CH═CH—, —C≡C—, —COO— or a single bond, and

i and j each, independently of one another, denote 0 or 1.

6. The liquid-crystalline medium according to claim 5 , further comprising one or more compounds of formulae VI to IX:

wherein

R 61 denotes an unsubstituted alkyl radical having 1 to 7 C atoms, an unsubstituted alkenyl radical having 2 to 7 C atoms, an unsubstituted alkoxy radical having 1 to 6 C atoms or an unsubstituted alkenyloxy radical having 2 to 6 C atoms,

R 62 denotes an unsubstituted alkyl radical having 1 to 7 C atoms, an unsubstituted alkoxy radical having 1 to 6 C atoms or an unsubstituted alkenyloxy radical having 2 to 6 C atoms, and

l denotes 0 or 1,

R 71 denotes an unsubstituted alkyl radical having 1 to 7 C atoms, or an unsubstituted alkenyl radical having 2 to 7 C atoms,

R 72 denotes an unsubstituted alkyl radical having 1 to 7 C atoms, an unsubstituted alkoxy radical having 1 to 6 C atoms or an unsubstituted alkenyloxy radical having 2 to 6 C atoms,

denotes

R 81 denotes an unsubstituted alkyl radical having 1 to 7 C atoms, or an unsubstituted alkenyl radical having 2 to 7 C atoms,

R 82 denotes an unsubstituted alkyl radical having 1 to 7 C atoms, an unsubstituted alkoxy radical having 1 to 6 C atoms or an unsubstituted alkenyloxy radical having 2 to 6 C atoms, preferably having 2, 3 or 4 C atoms,

denotes

Z 8 denotes —(C═O)—O—, —CH 2 —O—, —CF 2 —O— or —CH 2 —CH 2 —,

o denotes 0 or 1,

R 91 and R 92 independently of one another have the meaning given for R 72 above,

denotes

p and q independently of each other denote 0 or 1.

7. The liquid-crystalline medium according to claim 1 , further comprising one or more compounds of formula I

in which

denotes

denotes

n denotes 0 or 1,

R 11 and R 12 independently of each other denote alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy, preferably having 1 to 7 C atoms, wherein one —CH 2 — group may be replaced by cyclopropylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, wherein one —CH 2 — group may be replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, and R 11 alternatively denotes R 1 and R 12 alternatively denotes X 1 ,

R 1 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy wherein one —CH 2 — group may be replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, wherein one —CH 2 — group may be replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, and

X 1 denotes F, Cl, fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy or fluorinated alkenyoxy.

8. The liquid-crystalline medium according to claim 7 , having a total concentration of the compounds of formula T in the medium of 1% to 60%.

9. The liquid-crystalline medium according to claim 1 , additionally comprising one or more chiral compounds.

10. An electro-optical display or electro-optical component, comprising a liquid-crystalline medium according to claim 1 .

11. The electro-optical display according to claim 10 , operating in IPS-, FFS, HB-FFS or XB-FFS mode.

12. The electro-optical display according to claim 10 , containing an active-matrix addressing device.

13. The electro-optical display according to claim 10 , that is a mobile display.

14. A process for the preparation of a liquid-crystalline medium according to claim 1 , comprising mixing one or more compounds of formula T with one or more additional mesogenic compounds.

15. A compound of formula T

in which

denotes

independently of each other, denote

wherein the rings

optionally may each be substituted with one or two alkyl groups,

n denotes 1 or 2,

R S denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy, wherein one —CH 2 — group may be replaced by cyclopropylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, wherein one —CH 2 — group may be replaced by cyclopropylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, and

X S denotes F, CF 3 or OCF 3 .

16. A process for the preparation of a compound of formula T according to claim 15 , comprising coupling a fluorinated biphenyl halogenide to a polar thiophene boronic acid or an ester of a thiophene boronic acid.