Liquid crystal composition and liquid crystal element

1. A liquid crystal composition comprising:

at least one compound represented by Formula (1),

in Formula (1),

R 1 is C1-12 alkyl in which at least one —(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;

a ring A 1 is 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, 2,6,7-trioxabicyclo[2.2.2] octane-1,4-diyl, naphthalene-2,6-diyl, or pyridine-2,5-diyl, at least one hydrogen on these rings may be substituted with a halogen or C1-3 alkyl;

Z 11 is a single bond; Z 12 is —C≡C—;

L 11 , L 12 , L 13 , L 14 , L 15 , L 16 , L 17 , and L 18 are hydrogen, fluorine, chlorine, methyl, ethyl or cyclopropyl;

Y 11 is hydrogen, fluorine, chlorine, methyl or ethyl;

Y 12 is hydrogen, fluorine or chlorine;

at least one of L 14 , L 15 , L 16 , L 17 , L 18 , and Y 11 is methyl or ethyl;

at least one of L 14 , L 15 , L 16 , L 17 , L 18 , and Y 11 is fluorine; and

a is 0 or 1, b is 1, c is 0 or 1, and a sum of a, b, and c is 2.

2. The liquid crystal composition according to claim 1 , further comprising:

at least one compound selected from the group consisting of compounds represented by Formulae (2) and (3),

in Formula (2),

R 2 is hydrogen, a halogen, or C1-12 alkyl in which at least one —CH 2 — may be substituted with —O— or —S— and at least one —(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—, and at least one hydrogen in these groups may be substituted with a halogen;

a ring A 2 is 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, 2,6,7-trioxabicyclo[2.2.2] octane-1,4-diyl, naphthalene-2,6-diyl, or pyridine-2,5-diyl, at least one hydrogen on these rings may be substituted with a halogen or C1-3 alkyl;

Z 21 and Z 22 are a single bond, —C≡C— or —C≡C—C≡C—;

L 21 , L 22 , L 23 , and L 24 are hydrogen, a halogen, C1-3 alkyl, or C3-5 cycloalkyl;

X 2 is —C≡C—CF 3 or —C≡C—C≡N;

Y 21 and Y 22 are hydrogen, a halogen, or C1-3 alkyl; and

d is 0 or 1, e is 0, 1, 2, or 3, and a sum of d and e is 1 to 3, and

in Formula (3),

R 31 is hydrogen or C1-12 alkyl, and in this alkyl, at least one —CH 2 — may be substituted with —O— or —S— and at least one —(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;

R 32 is R 31 or —N═C═S;

a ring A 3 is pyrimidine-2,5-diyl, naphthalene-2,6-diyl, or pyridine-2,5-diyl, and at least one hydrogen on these rings may be substituted with a halogen or C1-3 alkyl;

Z 31 and Z 32 are a single bond, —C≡C— or —C≡C—C≡C—;

L 31 , L 32 , L 33 , L 34 , L 35 , L 36 , L 37 , L 38 , and L 39 are hydrogen or a halogen; and

f is 0 or 1, g is 0, 1, or 2, and a sum of f and g is 0 to 2.

3. The liquid crystal composition according to claim 1 ,

wherein a proportion of the compounds represented by Formula (1) is within a range of 5 weight % to 80 weight % based on a weight of the liquid crystal composition.

4. The liquid crystal composition according to claim 2 , comprising:

at least one compound selected from the group consisting of compounds represented by Formulae (2-1) to (2-8) as the compound represented by Formula (2),

in Formulae (2-1) to (2-8),

R 2′ is C1-12 alkyl, and in this alkyl, at least one —(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;

L 21′ , L 22′ , L 23′ , and L 24′ are hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl; and

Y 21′ and Y 22′ are hydrogen, fluorine, chlorine, methyl, or ethyl.

5. The liquid crystal composition according to claim 2 ,

wherein a proportion of the compounds represented by Formula (2) is within a range of 5 weight % to 50 weight % based on a weight of the liquid crystal composition.

6. The liquid crystal composition according to claim 2 , comprising:

at least one compound selected from the group consisting of compounds represented by Formulae (3-1) to (3-6) as the compound represented by Formula (3),

in Formulae (3-1) to (3-6),

R 31′ is C1-12 alkyl, and in this alkyl, at least one —CH 2 — may be substituted with —O— and at least one —(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;

R 32′ is R 31′ or —N═C═S;

L 32′ , L 34′ , L 35′ , L 36′ , L 37′ , L 38′ , and L 39′ are hydrogen, fluorine, or chlorine; and

in Formula (3-6), when L 35′ , L 36′ , L 38′ , and L 39′ are hydrogen, R 32′ is —N═C═S.

7. The liquid crystal composition according to claim 2 ,

wherein a proportion of the compounds represented by Formula (3) is within a range of 5 weight % to 50 weight % based on a weight of the liquid crystal composition.

8. The liquid crystal composition according to claim 1 ,

wherein refractive index anisotropy at 25° C. at a wavelength of 589 nm is 0.35 or more.

9. The liquid crystal composition according to claim 1 ,

wherein dielectric anisotropy at 25° C. in a frequency range below 1 MHz is 5 or more.

10. The liquid crystal composition according to claim 1 ,

wherein dielectric anisotropy at 25° C. at at least one frequency from 1 GHz to 10 THz is within a range of 0.50 to 3.0.

11. The liquid crystal composition according to claim 1 , further comprising:

an optically active compound.

12. The liquid crystal composition according to claim 1 , further comprising:

a polymerizable compound.

13. The liquid crystal composition according to claim 1 , further comprising:

at least one of an antioxidant, an ultraviolet absorber, an antistatic agent, and a dichroic dye.

14. An element comprising:

the liquid crystal composition according to claim 1 ,

wherein the element is used for switching and is capable of reversibly controlling a dielectric constant by reversibly changing an orientation direction of liquid crystal molecules.

15. An element comprising:

the liquid crystal composition according to claim 1 ,

wherein the element is used for controlling electromagnetic waves in a frequency range from 1 GHz to 10 THz.

16. A liquid crystal lens, comprising:

the liquid crystal composition according to claim 1 .

17. A birefringent lens for stereoscopic image display, comprising:

the liquid crystal composition according to claim 1 .