Liquid-crystalline medium and liquid-crystal display comprising the same

1. A liquid-crystalline medium which comprises: one or more compounds of formula T

in which

R S1 denotes optionally fluorinated alkyl or optionally fluorinated alkoxy having 1 to 7 C atoms, wherein one —CH 2 — group is optionally replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene or 1,3-cyclo-pentenylene, or alkenyloxy, alkoxyalkyl or optionally fluorinated alkenyl having 2 to 7 C atoms, wherein one —CH 2 — group is optionally replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene,

R S2 denotes optionally fluorinated alkyl or optionally fluorinated alkoxy having 1 to 7 C atoms, wherein one —CH 2 — group is optionally replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene or 1,3-cyclo-pentenylene, or optionally fluorinated alkenyloxy, alkoxyalkyl or optionally fluorinated alkenyl having 2 to 7 C atoms, wherein one —CH 2 — group is optionally replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, or denotes, F, Cl, CN, or NCS, and

Y S1 and Y S2 independently of one another, denote H or F, and

wherein one or more of the aromatic rings in formula T are optionally substituted by an alkyl group; and

one or more compounds of formula L

in which

R L1 denotes optionally fluorinated alkyl or optionally fluorinated alkoxy having 1 to 7 C atoms, wherein one —CH 2 — group are optionally replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, or optionally fluorinated alkenyl, or alkenyloxy or alkoxyalkyl of 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,

R L2 denotes optionally fluorinated alkyl or optionally fluorinated alkoxy having 1 to 7 C atoms, wherein one —CH 2 — group is optionally replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, or optionally fluorinated alkenyl, optionally fluorinated alkenyloxy or alkoxyalkyl of 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, or denotes F, Cl, CN, or NCS, and

Y L1 and Y L2 independently of one another, denote H or F, and

wherein the aromatic ring in formula L is optionally further substituted by an alkyl group.

2. The medium according to claim 1 , which comprises one or more compounds of formula T, which are selected from compounds of formulae T-1 and T-2:

wherein R S1 , R S2 , Y S1 and Y S2 have the respective meanings given under formula T above, with the exception that R S2 in formula T-1 may not denote X S , and

in which

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

X S denotes F, Cl, CN, NCS, fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy or fluorinated alkenyloxy, the fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy and fluorinated alkenyloxy groups having 1 to 4 C atoms, and

wherein the one or more of the aromatic rings in formula T-2 are optionally be substituted by an alkyl group.

3. The medium according to claim 2 , which comprises one or more compounds of formula T-1.

4. The medium according to claim 1 , which comprises one or more compounds of formula L, which are selected from compounds of formulae L-1 and L-2:

wherein R 1L , R 2L , Y L1 and Y L2 have the respective meanings given under formula L in claim 1 , with the exception that R L2 in formula L-1 may not denote X L , and in which

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

X L denotes F, Cl, CN, NCS, fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy or fluorinated alkenyloxy, the fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy and fluorinated alkenyloxy groups having 1 to 4 C atoms, and

wherein the aromatic ring in formulae L-1 and L-2 is optionally substituted by an alkyl group.

5. The medium according to claim 4 , which comprises one or more compounds of formula L-2.

6. The medium according to claim 4 , which comprises one or more compounds of formula L-1.

7. The medium according to claim 1 , which further comprises one or more compounds selected from compounds of formulae II and III:

in which

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

on each appearance, independently of one another, denote

L 21 and L 22 denote H or F,

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,

m denotes 0, 1, 2 or 3,

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

wherein the one or more of the aromatic rings in formulae II and III are optionally be substituted by an alkyl group,

with the condition that the compounds of formula L are excluded from formula III.

8. The medium according to claim 1 , which further comprises one or more compounds of formulae IV and V:

in which

R 41 and R 42 , independently of one another, denote optionally fluorinated alkyl or optionally fluorinated alkoxy having 1 to 7 C atoms, or alkenyloxy, alkoxyalkyl or optionally fluorinated alkenyl having 2 to 7 C atoms,

independently of one another and, if

 occurs twice,

also these independently of one another, denote

Z 41 and Z 42 , independently of one another and, if Z 41 occurs twice, also these independently of one another, denote —CH 2 CH 2 —, —COO—, trans-CH═CH—, trans-CF═CF—, —CH 2 O—, —CF 2 O—, —C≡C— or a single bond,

p denotes 0, 1 or 2,

R 51 and R 52 , independently of one another, have one of the meanings given for R 41 and R 42

 to

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

wherein one or more of the aromatic rings in formulae IV and V are optionally substituted by an alkyl group, and

with the condition that the compounds of formula L are excluded from formula IV.

9. The medium according to claim 1 , wherein the total concentration of the compounds of formula T in the medium as a whole is 3% or more to 60% or less.

10. The medium according to claim 1 , which additionally comprises one or more chiral compounds.

11. The electro-optical display or electro-optical component, which comprises a liquid-crystalline medium according to claim 1 .

12. The electro-optical display according to claim 11 , which is based on the IPS- or FFS mode.

13. The electro-optical display according to claim 11 , which contains an active-matrix addressing device.

14. The electro-optical display according to claim 11 , which is a display for gaming or a mobile display.

15. A process for the preparation of the liquid-crystalline medium according to claim 1 , comprising mixing one or more compounds of formula T with one or more compounds of formula L and, optionally, with one or more mesogenic compounds different from those of the formula T or formula L.

16. The medium according to claim 8 , wherein the total concentration of the compounds of formula T in the medium as a whole is 3% or more to 60% or less.

17. The medium according to claim 1 , wherein the total concentration of the compounds of formula T in the medium as a whole is 5% or more to 40% or less.

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

for R S1 and R S2 one —CH 2 — group is optionally replaced by cyclopropylene or 1,3-cyclopentylene,

alternatively, R S2 denotes X S , where

X S is F, Cl, CF 3 or OCF 3 ,

for Y S1 and Y S2 at least one denotes F,

the optional alkyl group substitutions for the aromatic rings in formula T are methyl,

for R L1 and R L2 one —CH 2 — group is optionally replaced by cyclopropylene or 1,3-cyclopentylene,

alternatively, R L2 denotes X L , where

X L denotes F, Cl, CF 3 or OCF 3 ,

for Y L1 and Y L2 at least one of them denote H, and

the optional alkyl group substitutions for the aromatic ring in formula L are methyl.

19. The medium according to claim 2 , wherein:

for R S one —CH 2 — group is optionally replaced by cyclopropylene or 1,3-cyclopentylene,

X S denotes F, Cl, CF 3 or OCF 3 , and

the optional alkyl group substitutions for the aromatic rings in formulae T-1 and T-2 are methyl.

20. The medium according to claim 4 , wherein:

R L is alkyl, alkoxy, alkenyl or alkenyloxy and the options for one —CH 2 — group is optionally replaced by cyclopropylene or 1,3-cyclopentylene,

X L denotes F, Cl, CF 3 or OCF 3 , and

wherein at least one of the aromatic rings for L-1 or L-2 are optionally substituted by methyl.

21. The medium according to claim 1 , wherein

R S2 denotes optionally fluorinated alkyl or optionally fluorinated alkoxy having 1 to 7 C atoms, wherein one —CH 2 — group is optionally replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene or 1,3-cyclo-pentenylene, or optionally fluorinated alkenyloxy, alkoxyalkyl or optionally fluorinated alkenyl having 2 to 4 C atoms, wherein one —CH 2 — group is optionally replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, or denotes, F, Cl, CN, or NCS, and

R L2 denotes optionally fluorinated alkyl or optionally fluorinated alkoxy having 1 to 7 C atoms, wherein one —CH 2 — group is optionally replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclo-pentenylene, or optionally fluorinated alkenyl, optionally fluorinated alkenyloxy or alkoxyalkyl of 2 to 4 C atoms, wherein one —CH 2 — group may be replaced by cyclo-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene or 1,3-cyclo-pentenylene, or denotes F, Cl, CN, or NCS.