Liquid crystal compound, liquid crystal composition, and liquid crystal display device

1. A compound represented by Formula (1):

wherein Ra and Rb each independently is hydrogen or linear alkyl having 1 to 20 carbon atoms; in the alkyl, arbitrary —CH 2 — may be replaced by —O—, or —CH═CH and arbitrary hydrogen may be replaced by fluorine;

ring A 1 is 1,4-cyclohexylene, 1,4-phenylene, pyridine-2,5-diyl, pyridazine-3,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, 5,6,7,8-tetrahydronaphthalene-2,6-diyl, or naphthalene-2,6-diyl; arbitrary —CH 2 — constituting the rings may be replaced by —O—, and arbitrary hydrogen directly bonded to the rings may be replaced by fluorine, —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , or —OCH 2 F;

Z 1 is a single bond or alkylene having 1 to 4 carbon atoms; in the alkylene, arbitrary —CH 2 — may be replaced by —O—, —CO—, —CH═CH—, —CF═CF—, or —C≡C—, and arbitrary hydrogen may be replaced by fluorine;

Y 1 is hydrogen, fluorine, chlorine, —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , or —OCH 2 F; and

m is 1, 2, or 3; and when m is 2 or 3, plural rings A 1 may be identical groups or different groups, and plural Z 1 may be identical groups or different groups.

2. The compound according to claim 1 , wherein Ra and Rb each independently is linear alkyl having 1 to 20 carbon atoms, linear alkoxy having 1 to 19 carbon atoms, linear alkoxyalkyl having 2 to 19 carbon atoms, linear alkenyl having 2 to 21 carbon atoms, linear fluorinated alkyl having 1 to 20 carbon atoms, or linear fluorinated alkoxy having 1 to 19 carbon atoms;

ring A 1 is 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyridine-2,5-diyl, 6-fluoropyridine-2,5-diyl, or pyridazine-3,6-diyl;

Z 1 is a single bond, —(CH 2 ) 2 —, —COO—, —OCO—, —CH 2 O—, —OCH 2 —, —CF 2 O—, —OCF 2 —, —CH═CH—, —CF═CF—, —C≡C—, —CH 2 CO—, —COCH 2 —, —(CH 2 ) 2 COO—, —OCO(CH 2 ) 2 —, —(CH 2 ) 2 CF 2 O—, —OCF 2 (CH 2 ) 2 —, —(CH 2 ) 3 O—, —O(CH 2 ) 3 —, or —(CH 2 ) 4 —; and

Y 1 is hydrogen, fluorine, chlorine, —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , or —OCH 2 F.

3. The compound according to claim 1 , wherein Ra and Rb each independently is linear alkyl having 1 to 10 carbon atoms, linear alkoxy having 1 to 10 carbon atoms, linear alkoxyalkyl having 2 to 10 carbon atoms, linear alkenyl having 2 to 10 carbon atoms, linear fluorinated alkyl having 1 to 10 carbon atoms, or linear fluorinated alkoxy having 1 to 10 carbon atoms;

ring A 1 independently is 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, or 2,6-difluoro-1,4-phenylene;

Z 1 independently is a single bond, —(CH 2 ) 2 —, —COO—, —OCO—, —CH 2 O—, —OCH 2 —, —CF 2 O—, —OCF 2 —, —CH═CH—, —CF═CF—, —C≡C—, —(CH 2 ) 2 COO—, —OCO(CH 2 ) 2 —, —(CH 2 ) 2 CF 2 O—, —OCF 2 (CH 2 ) 2 —, —(CH 2 ) 3 O—, —O(CH 2 ) 3 —, or —(CH 2 ) 4 —; and

Y 1 is hydrogen, fluorine, chlorine, —CF 3 , —CHF 2 , or —CH 2 F.

4. The compound according to claim 1 , wherein Ra and Rb each independently is linear alkyl having 1 to 10 carbon atoms, linear alkoxy having 1 to 10 carbon atoms, linear alkoxyalkyl having 2 to 10 carbon atoms, linear alkenyl having 2 to 10 carbon atoms, —CH 2 F, or —OCH 2 F;

ring A 1 is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,3-difluoro-1,4-phenylene;

Z 1 is a single bond, —(CH 2 ) 2 —, —COO—, —OCO—, —CH 2 O—, —OCH 2 —, —CF 2 O—, —OCF 2 —, —CH═CH—, or —C≡C—; and

Y 1 is hydrogen, fluorine, —CF 2 H, or —CF 3 .

5. The compound according to claim 1 , wherein Ra is linear alkoxy having 1 to 6 carbon atoms, linear alkoxyalkyl having 2 to 6 carbon atoms, or an linear alkenyl having 2 to 6 carbon atoms;

Rb is linear alkyl having 1 to 6 carbon atoms or linear alkoxy having 1 to 6 carbon atoms;

ring A 1 is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,3-difluoro-1,4-phenylene;

Z 1 is a single bond or —(CH 2 ) 2 —; and

Y 1 is hydrogen or fluorine.

6. A compound represented by one of formulae (I) to (V):

wherein Ra and Rb each independently is linear alkyl having 1 to 10 carbon atoms, linear alkoxy having 1 to 10 carbon atoms, linear alkoxyalkyl having 2 to 10 carbon atoms, or an linear alkenyl having 2 to 10 carbon atoms;

Z 1 independently is a single bond, —(CH 2 ) 2 —, —COO—, —OCO—, —CH 2 O—, —OCH 2 —, —CF 2 O—, —OCF 2 —, —CH═CH—, —CF═CF—, —C≡C—, —(CH 2 ) 2 COO—, —OCO(CH 2 ) 2 —, —(CH 2 ) 2 CF 2 O—, —(CH 2 ) 3 O—, —O(CH 2 ) 3 —, or —(CH 2 ) 4 —; and

Y 1 is hydrogen, fluorine, chlorine, —CF 3 , or —CF 2 H.

7. The compound according to claim 6 , wherein Ra and Rb each independently is linear alkyl having 1 to 10 carbon atoms, linear alkoxy having 1 to 10 carbon atoms, or linear alkenyl having 2 to 10 carbon atoms;

Z 1 independently is a single bond, —(CH 2 ) 2 —, —CH═CH—, or —(CH 2 ) 4 —; and

Y 1 is hydrogen, fluorine, chlorine, —CF 3 , or —CF 2 H.

8. The compound according to claim 6 , wherein Ra and Rb each independently is linear alkyl having 1 to 10 carbon atoms, linear alkoxy having 1 to 10 carbon atoms, or linear alkenyl having 2 to 10 carbon atoms;

Z 1 independently is a single bond or —(CH 2 ) 2 —; and

Y 1 is hydrogen, fluorine, or —CF 3 .

9. The compound according to claim 6 , wherein Ra and Rb each independently is linear alkyl having 1 to 6 carbon atoms;

Z 1 is a single bond; and

Y 1 is fluorine.

10. A compound represented by the formula below:

11. A compound represented by the formula below:

12. A compound represented by the formula below:

13. A liquid crystal composition comprising at least one compound selected from the group consisting of the compounds according to claim 1 .

14. The liquid crystal composition according to claim 13 , wherein the composition further comprises at least one compound selected from the group consisting of compounds represented by Formulae (2), (3) and (4):

wherein R 1 is an alkyl having 1 to 10 carbon atoms; in the alkyl, arbitrary —CH 2 — may be replaced by —O— or —CH═CH—, and arbitrary hydrogen may be replaced by fluorine;

X 1 is fluorine, chlorine, —OCF 3 , —OCHF 2 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 2 CHF 2 , or —OCF 2 CHFCF 3 ;

ring B independently is 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, or 1,4-phenylene, in which arbitrary hydrogen may be replaced by fluorine;

Z 4 independently is —(CH 2 ) 2 —, —(CH 2 ) 4 —, —COO—, —CF 2 O—, —OCF 2 —, —CH 2 ═CH 2 —, or a single bond; and

L 1 independently is hydrogen or fluorine.

15. The liquid crystal composition according to claim 13 , wherein the composition further comprises at least one compound selected from the group consisting of compounds represented by Formulae (5) and (6):

wherein R 1 is an alkyl having 1 to 10 carbon atoms; in the alkyl, arbitrary —CH 2 — may be replaced by —O— or —CH═CH—, and arbitrary hydrogen may be replaced by fluorine;

X 2 is —CN or —C≡C—CN;

ring G is 1,4-cyclohexylene, 1,4-phenylene, 1,3-dioxane-2,5-diyl, or pyrimidine-2,5-diyl;

ring J is 1,4-cyclohexylene, pyrimidine-2,5-diyl, or 1,4-phenylene in which arbitrary hydrogen may be replaced by fluorine;

ring K is 1,4-cyclohexylene or 1,4-phenylene;

Z 5 is —(CH 2 ) 2 —, —COO—, —CF 2 O—, —OCF 2 —, or a single bond;

L 1 independently is hydrogen or fluorine; and

b independently is 0 or 1.

16. The liquid crystal composition according to claim 13 , wherein the composition further comprises at least one compound selected from the group consisting of compounds represented by Formulae (7), (8), (9), (10) and (11):

wherein R 1 is an alkyl having 1 to 10 carbon atoms; in the alkyl, arbitrary —CH 2 — may be replaced by —O— or —CH═CH—, and arbitrary hydrogen may be replaced by fluorine;

R 2 is fluorine or an alkyl having 1 to 10 carbon atoms; in the alkyl, arbitrary —CH 2 — may be replaced by —O— or —CH═CH—, and arbitrary hydrogen may be replaced by fluorine;

ring M is 1,4-cyclohexylene, 1,4-phenylene, or decahydro-2,6-naphthalene;

Z 6 independently is —(CH 2 ) 2 —, —COO—, or a single bond; and

L 2 independently is hydrogen or fluorine, and at least one of L 2 is fluorine.

17. The liquid crystal composition according to claim 13 , wherein the composition further comprises at least one compound selected from the group consisting of compounds represented by Formulae (12), (13) and (14):

wherein R 1 independently is an alkyl having 1 to 10 carbon atoms; in the alkyl, arbitrary —CH 2 — may be replaced by —O— or —CH═CH—, and arbitrary hydrogen may be replaced by fluorine;

ring J independently is 1,4-cyclohexylene, pyrimidine-2,5-diyl, or 1,4-phenylene in which arbitrary hydrogen may be replaced by fluorine; and

Z 7 independently is —C≡C—, —COO—, —(CH 2 ) 2 —, —CH═CH—, or a single bond.

18. The liquid crystal composition according to claim 14 , wherein the composition further comprises at least one compound selected from the group consisting of compounds represented by Formulae (5) and (6):

wherein R 1 is an alkyl having 1 to 10 carbon atoms; in the alkyl, arbitrary —CH 2 — may be replaced by —O— or —CH═CH—, and arbitrary hydrogen may be replaced by fluorine;

X 2 is —CN or —C≡C—CN;

ring G is 1,4-cyclohexylene, 1,4-phenylene, 1,3-dioxane-2,5-diyl, or pyrimidine-2,5-diyl;

ring J is 1,4-cyclohexylene, pyrimidine-2,5-diyl, or 1,4-phenylene in which arbitrary hydrogen may be replaced by fluorine;

ring K is 1,4-cyclohexylene or 1,4-phenylene;

Z 5 is —(CH 2 ) 2 —, —COO—, —CF 2 O—, —OCF 2 —, or a single bond;

L 1 independently is hydrogen or fluorine; and

b independently is 0 or 1.

19. The liquid crystal composition according to claim 14 , wherein the composition further comprises at least one compound selected from the group consisting of compounds represented by Formulae (12), (13) and (14):

wherein R 1 independently is an alkyl having 1 to 10 carbon atoms; in the alkyl, arbitrary —CH 2 — may be replaced by —O— or —CH═CH—, and arbitrary hydrogen may be replaced by fluorine;

ring J independently is 1,4-cyclohexylene, pyrimidine-2,5-diyl, or 1,4-phenylene in which arbitrary hydrogen may be replaced by fluorine; and

Z 7 independently is —C≡C—, —COO—, —(CH 2 ) 2 —, —CH═CH—, or a single bond.

20. The liquid crystal composition according to claim 15 , wherein the composition further comprises at least one compound selected from the group consisting of compounds represented by formulae (12), (13) and (14):

wherein R 1 independently is an alkyl having 1 to 10 carbon atoms; in the alkyl, arbitrary —CH 2 — may be replaced by —O— or —CH═CH—, and arbitrary hydrogen may be replaced by fluorine;

ring J independently is 1,4-cyclohexylene, pyrimidine-2,5-diyl, or 1,4-phenylene in which arbitrary hydrogen may be replaced by fluorine; and

Z 7 independently is —C≡C—, —COO—, —(CH 2 ) 2 —, —CH═CH—, or a single bond.

21. The liquid crystal composition according to claim 16 , wherein the composition further comprises at least one compound selected from the group consisting of compounds represented by Formulae (12), (13) and (14):

wherein R 1 independently is an alkyl having 1 to 10 carbon atoms; in the alkyl, arbitrary —CH 2 — may be replaced by —O— or —CH═CH—, and arbitrary hydrogen may be replaced by fluorine;

ring J independently is 1,4-cyclohexylene, pyrimidine-2,5-diyl, or 1,4-phenylene in which arbitrary hydrogen may be replaced by fluorine; and

Z 7 independently is —C≡C—, —COO—, —(CH 2 ) 2 —, —CH═CH—, or a single bond.

22. The liquid crystal composition according to claim 13 , wherein the composition further comprises an optically active compound.

23. A liquid crystal display device comprising the liquid crystal composition according to claim 13 .