Trans-monofluoroethylene liquid crystal compound having negative dielectric anisotropy, a liquid crystal composition using the compound and a liquid crystal display device

1. A compound represented by formula (1):

wherein R 1 and R 2 are each independently alkyl having 1 to 10 carbons, and in the alkyl, arbitrary —CH 2 — may be replaced by —O—, —S—, —CO—, —CH═CH— or —C≡C—, and in these groups, arbitrary hydrogen may be replaced by halogen or —C≡N; A 1 and A 2 are each independently 1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-phenylene, and in these rings, arbitrary —CH 2 — may be replaced by —O—, arbitrary —CH═ may be replaced by —N═, and arbitrary hydrogen may be replaced by fluorine, chlorine or bromine; Z 1 and Z 2 are each independently a single bond, —(CH 2 ) 2 —, —(CF 2 ) 2 —, —COO—, —OCO—, —OCH 2 —, —CH 2 O—, —CH═CH—, —C≡C—, —(CH 2 ) 4 —, —O(CH 2 ) 3 — or —(CH 2 ) 3 O—; X is fluorine or chlorine; and p and q are each independently 0 or 1.

2. The compound according to claim 1 , wherein R 1 and R 2 are each independently alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons or alkoxy having 1 to 9 carbons; A 1 and A 2 are each independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2-fluoro-1,4-phenylene or 3-fluoro-1,4-phenylene; Z 1 and Z 2 are each independently a single bond, —(CH 2 ) 2 —, —COO—, —OCO—, —OCH 2 —, —CH 2 O—, —CH═CH— or —C≡C—.

3. The compound according to claim 1 , wherein R 1 is alkyl having 1 to 10 carbons; R 2 is alkoxy having 1 to 9 carbons; A 1 is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene or 2,3-difluoro-1,4-phenylene; Z 1 is a single bond; X is fluorine; and p is 1 and q is 0.

4. The compound according to claim 1 , wherein R 1 is alkyl having 1 to 10 carbons; R 2 is alkoxy having 1 to 9 carbons; A 1 and A 2 are each independently 1,4-cyclohexylene, 1,4-phenylene or 2,3-difluoro-1,4-phenylene; Z 1 and Z 2 are a single bond; X is fluorine; and p is 1 and q is 1.

5. A liquid crystal composition comprising at least one of compounds according to claim 1 .

6. The liquid crystal composition according to claim 5 , further comprising at least one compound selected from the group of compounds represented by formulas (2), (3) and (4):

wherein R 3 is alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in these groups, arbitrary hydrogen may be replaced by fluorine and arbitrary —CH 2 — may be replaced by —O—; X 1 is fluorine or chlorine; the ring A 2 , the ring A 3 and the ring A 4 are each independently 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, tetrahydropyran-2,5-diyl or 1,4-phenylene in which arbitrary hydrogen may be replaced by fluorine; Z 1 and Z 2 are each independently —(CH 2 ) 2 —, —(CH 2 ) 4 —, —COO—, —CF 2 O—, —OCF 2 —, —CH═CH—, —C≡C—, —CH 2 O— or a single bond; and L 1 and L 2 are each independently hydrogen or fluorine.

7. The liquid crystal composition according to claim 5 , further comprising at least one compound selected from the group of compounds represented by formula (5):

wherein R 4 is alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and the alkenyl, arbitrary hydrogen may be replaced by fluorine and arbitrary —CH 2 — may be replaced by —O—; X 2 is —C≡N or —C≡C—C≡N; the ring B 1 , the ring B 2 and the ring B 3 are each independently 1,4-cyclohexylene, 1,4-phenylene in which arbitrary hydrogen may be replaced by fluorine, 1,3-dioxane-2,5-diyl, tetrahydropyran-2,5-diyl or pyrimidine-2,5-diyl; Z 3 is —(CH 2 ) 2 —, —COO—, —CF 2 O—, —OCF 2 —, —C≡C—, —CH 2 O— or a single bond; L 3 and L 4 are each independently hydrogen or fluorine; and q is 0, 1 or 2 and r is 0 or 1.

8. The liquid crystal composition according to claim 5 , further comprising at least one compound selected from the group of compounds represented by formulas (6), (7), (8), (9), (10) and (11):

wherein R 5 is alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in these groups, arbitrary hydrogen may be replaced by fluorine; R 6 is alkoxy having 1 to 9 carbons or alkenyloxy having 2 to 9 carbons, and in these groups, arbitrary hydrogen may be replaced by fluorine; the ring C 1 , the ring C 2 , the ring C 3 and the ring C 4 are each independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene in which arbitrary hydrogen may be replaced by fluorine, tetrahydropyran-2,5-diyl or decahydronaphthalene-2,6-diyl; Z 4 , Z 5 , Z 6 and Z 7 are each independently —(CH 2 ) 2 —, —COO—, —CH 2 O—, —OCF 2 —, —OCF 2 (CH 2 ) 2 — or a single bond; L 5 and L 6 are each independently fluorine or chlorine; and j, k, l, m, n and p are each independently 0 or 1, and the sum of k, l, m and n is 1 or 2.

9. The liquid crystal composition according to claim 5 , further comprising at least one compound selected from the group of compounds represented by formulas (12), (13) and (14):

wherein R 7 and R 8 are each independently alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in these groups, arbitrary hydrogen may be replaced by fluorine and arbitrary —CH 2 — may be replaced by —O—; the ring D 1 , the ring D 2 and the ring D 3 are each independently 1,4-cyclohexylene, pyrimidine-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; and Z 8 and Z 9 are each independently —C≡C—, —COO—, —(CH 2 ) 2 —, —CH═CH— or a single bond.

10. The liquid crystal composition according to claim 6 , further comprising at least one compound selected from the group of compounds represented by formula (5):

wherein R 4 is alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in the alkyl and the alkenyl, arbitrary hydrogen may be replaced by fluorine and arbitrary —CH 2 — may be replaced by —O—; X 2 is —C≡N or —C≡C—C≡N; the ring B 1 , the ring B 2 and the ring B 3 are each independently 1,4-cyclohexylene, 1,4-phenylene in which arbitrary hydrogen may be replaced by fluorine, 1,3-dioxane-2,5-diyl, tetrahydropyran-2,5-diyl or pyrimidine-2,5-diyl; Z 3 is —(CH 2 ) 2 —, —COO—, —CF 2 O—, —OCF 2 —, —C≡C—, —CH 2 O— or a single bond; L 3 and L 4 are each independently hydrogen or fluorine; and q is 0, 1 or 2 and r is 0 or 1.

11. The liquid crystal composition according to claim 6 , further comprising at least one compound selected from the group of compounds represented by formulas (12), (13) and (14):

wherein R 7 and R 8 are each independently alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in these groups, arbitrary hydrogen may be replaced by fluorine and arbitrary —CH 2 — may be replaced by —O—; the ring D 1 , the ring D 2 and the ring D 3 are each independently 1,4-cyclohexylene, pyrimidine-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; and Z 8 and Z 9 are each independently —C≡C, —COO—, —(CH 2 ) 2 —, —CH═CH— or a single bond.

12. The liquid crystal composition according to claim 7 , further comprising at least one compound selected from the group of compounds represented by formulas (12), (13) and (14):

wherein R 7 and R 8 are each independently alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in these groups, arbitrary hydrogen may be replaced by fluorine and arbitrary —CH 2 — may be replaced by —O—; the ring D 1 , the ring D 2 and the ring D 3 are each independently 1,4-cyclohexylene, pyrimidine-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; and Z 8 and Z 9 are each independently —C≡C—, —COO—, —(CH 2 ) 2 —, —CH═CH— or a single bond.

13. The liquid crystal composition according to claim 8 , further comprising at least one compound selected from the group of compounds represented by formulas (12), (13) and (14):

wherein R 7 and R 8 are each independently alkyl having 1 to 10 carbons or alkenyl having 2 to 10 carbons, and in these groups, arbitrary hydrogen may be replaced by fluorine and arbitrary —CH 2 — may be replaced by —O—; the ring D 1 , the ring D 2 and the ring D 3 are each independently 1,4-cyclohexylene, pyrimidine-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; and Z 8 and Z 9 are each independently —C≡C—, —COO—, —(CH 2 ) 2 —, —CH═CH— or a single bond.

14. The liquid crystal composition according claim 5 , further comprising at least one optically active compound and/or one polymerizable compound.

15. The liquid crystal composition according to claim 5 , further comprising at least one antioxidant and/or one ultraviolet light absorber.

16. A liquid crystal display device containing the liquid crystal composition according to claim 5 .