JP7464204B1 - Compound, and liquid crystal composition, liquid crystal display element, sensor, liquid crystal lens, optical communication device, and antenna using the compound - Google Patents

Abstract

The present invention aims to provide a compound capable of providing a liquid crystal composition having large Δn and large Δεr and having good storage stability at low temperature or room temperature, and a liquid crystal composition, a liquid crystal display element, a sensor, a liquid crystal lens, an optical communication device, and an antenna using the same. Specifically, the present invention provides a compound represented by general formula (i) having a predetermined indene structure and a predetermined side chain structure including an isothiocyanate group (-NCS) group, and a liquid crystal composition, a liquid crystal display element, a sensor, a liquid crystal lens, an optical communication device, and an antenna using the same.

Description

The present invention relates to a compound and a liquid crystal composition, a liquid crystal display element, a sensor, a liquid crystal lens, an optical communication device and an antenna using the compound.

Liquid crystals are widely used in displays, but as a new application, liquid crystal antennas that transmit and receive radio waves between a mobile object such as a car and a communication satellite are attracting attention. Conventionally, satellite communication uses parabolic antennas, but when used in a mobile object such as a car, the parabolic antenna must be pointed toward the satellite at any time, which requires a large movable part. However, liquid crystal antennas can change the direction of radio waves by moving the liquid crystal inside the panel, so there is no need to move the antenna itself and the shape of the antenna can be made flat. In addition, in order to realize global high-capacity and high-speed communication, low-orbit satellite constellations using a large number of low-orbit satellites are being studied. Liquid crystal antennas, which can easily change the direction of radio waves, are useful for tracking low-orbit satellites that appear to be constantly moving from the ground.
Generally, automatic driving of automobiles and the like requires downloading a large amount of data of high-precision 3D map information. However, if an antenna using liquid crystal is incorporated into an automobile, it becomes possible to download a large amount of data from a communication satellite without any mechanical moving parts. The frequency band used in satellite communication is about 13 GHz, which is significantly different from the frequencies used for liquid crystal displays up to now. Therefore, the required physical properties of the liquid crystal are also significantly different, and the Δn required for the liquid crystal for the antenna is, for example, about 0.4, and the operating temperature range is, for example, from -20 to 120°C.
Infrared laser image recognition and distance measuring devices using liquid crystals are also attracting attention as sensors for automatic driving of moving objects such as automobiles. The Δn required for liquid crystals for this purpose is, for example, 0.3 to 0.6, and the operating temperature range is, for example, 10 to 100°C.
Furthermore, it is known that many liquid crystal compounds constituting a liquid crystal composition exhibiting a high Δn of 0.2 or more have low compatibility, and therefore it is also important to select a liquid crystal compound having high compatibility.
On the other hand, as a technique for liquid crystal for antennas, for example, Patent Document 1 can be mentioned.
Also, Non-Patent Document 1 proposes the use of liquid crystal materials as components of high frequency devices.

JP 2016-37607 A

Dolfi, Electronics Letters, (UK), 1993, Vol. 29, No. 10, pp. 926-928

An object of the present invention is to provide a compound capable of providing a liquid crystal composition having large Δn and large Δε _r and having good storage stability at low temperature or room temperature, and a liquid crystal composition, a liquid crystal display element, a sensor, a liquid crystal lens, an optical communication device, and an antenna using the same.

As a result of intensive investigations, the present inventors have found that a compound represented by general formula (i) having a specific side chain structure including an indene structure and an isothiocyanate group (-NCS) can solve the above problems, and have completed the present invention.
An example of the configuration of the present invention that solves the above problem is as follows.

Item 1. The following general formula (i)

（一般式（ｉ）中、
Ｒ^ｉ１は、水素原子又は炭素原子数１～２０のアルキル基を表し、
当該アルキル基中の１つ又は２つ以上の－ＣＨ_２－は、それぞれ独立して、－Ｏ－、－Ｓ－、－ＣＯ－及び／又は－ＣＳ－で置換されていてもよく、
当該アルキル基中の１つ又は２つ以上の－ＣＨ_２－ＣＨ_２－は、それぞれ独立して、－ＣＯ－Ｏ－、－Ｏ－ＣＯ－、－ＣＯ－Ｓ－、－Ｓ－ＣＯ－、－ＣＯ－ＮＨ－、－ＮＨ－ＣＯ－、－ＣＨ＝ＣＨ－、－ＣＦ＝ＣＦ－及び／又は－Ｃ≡Ｃ－で置換されていてもよく、
当該アルキル基中の１つ又は２つ以上の水素原子は、それぞれ独立して、ハロゲン原子で置換されていてもよいが、
酸素原子と酸素原子が直接結合することはなく、
Ｘ^ｉ１は、水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、ペンタフルオロスルファニル基、ニトロ基、シアノ基、イソシアノ基、アミノ基、ヒドロキシル基、メルカプト基、チオイソシアノ基、イソチオシアネート基、イソシアネート基又は炭素原子数１～２０のアルキル基を表し、
当該アルキル基中の１つ又は２つ以上の－ＣＨ_２－は、それぞれ独立して、－Ｏ－、－Ｓ－、－ＣＯ－及び／又は－ＣＳ－で置換されていてもよく、
当該アルキル基中の１つ又は２つ以上の－ＣＨ_２－ＣＨ_２－は、それぞれ独立して、－ＣＯ－Ｏ－、－Ｏ－ＣＯ－、－ＣＯ－Ｓ－、－Ｓ－ＣＯ－、－ＣＯ－ＮＨ－、－ＮＨ－ＣＯ－、－ＣＨ＝ＣＨ－、－ＣＦ＝ＣＦ－及び／又は－Ｃ≡Ｃ－で置換されていてもよく、
当該アルキル基中の１つ又は２つ以上の水素原子は、それぞれ独立して、ハロゲン原子で置換されていてもよいが、
酸素原子と酸素原子が直接結合することはなく、
Ａ^ｉ１及びＡ^ｉ２は、それぞれ独立して、炭素原子数３～１６の炭化水素環又は炭素原子数３～１６の複素環のいずれかを表し、
前記Ａ^ｉ１及びＡ^ｉ２中の１つ又は２つ以上の水素原子は、それぞれ独立して、置換基Ｓ^ｉ１によって置換されていてもよく、
置換基Ｓ^ｉ１は、フッ素原子、塩素原子、臭素原子、ヨウ素原子、ペンタフルオロスルファニル基、ニトロ基、シアノ基、イソシアノ基、アミノ基、ヒドロキシル基、メルカプト基、メチルアミノ基、ジメチルアミノ基、ジエチルアミノ基、ジイソプロピルアミノ基、トリメチルシリル基、ジメチルシリル基、チオイソシアノ基、炭素原子数１～２０のアルキル基のいずれかを表し、
当該アルキル基における１つ又は２つ以上の－ＣＨ_２－は、それぞれ独立して、－Ｏ－、－Ｓ－及び／又は－ＣＯ－で置換されていてもよく、
当該アルキル基における１つ又は２つ以上の－ＣＨ_２－ＣＨ_２－は、それぞれ独立して、－ＣＨ＝ＣＨ－、－ＣＦ＝ＣＦ－、－Ｃ≡Ｃ－、－ＣＯ－Ｏ－、－Ｏ－ＣＯ－、－ＣＯ－Ｓ－、－Ｓ－ＣＯ－、－ＣＯ－ＮＨ－及び／又は－ＮＨ－ＣＯ－で置換されていてもよく、
当該アルキル基における１つ又は２つ以上の水素原子は、それぞれ独立して、ハロゲン原子で置換されていてもよいが、
酸素原子と酸素原子が直接結合することはなく、
置換基Ｓ^ｉ１が複数ある場合は、それらは同一であってもよく、異なっていてもよく、
Ｌ^ｉ１及びＬ^ｉ２は、それぞれ独立して、水素原子、フッ素原子、塩素原子、臭素原子、ヨウ素原子、ペンタフルオロスルファニル基、ニトロ基、シアノ基、イソシアノ基、アミノ基、ヒドロキシル基、メルカプト基、メチルアミノ基、ジメチルアミノ基、ジエチルアミノ基、ジイソプロピルアミノ基、トリメチルシリル基、ジメチルシリル基、チオイソシアノ基又は炭素原子数１から２０のアルキル基のいずれかを表し、
当該アルキル基における１つ又は２つ以上の－ＣＨ_２－は、それぞれ独立して、－Ｏ－、－Ｓ－、－ＣＯ－及び／又は－ＣＳ－で置換されていてもよく、
当該アルキル基における１つ又は２つ以上の－ＣＨ_２－ＣＨ_２－は、それぞれ独立して、－ＣＨ＝ＣＨ－、－ＣＦ＝ＣＦ－、－Ｃ≡Ｃ－、－ＣＯ－Ｏ－、－Ｏ－ＣＯ－、－ＣＯ－Ｓ－、－Ｓ－ＣＯ－、－ＣＯ－ＮＨ－及び／又は－ＮＨ－ＣＯ－で置換されていてもよく、
当該アルキル基における１つ又は２つ以上の水素原子は、それぞれ独立して、ハロゲン原子で置換されていてもよいが、
酸素原子と酸素原子が直接結合することはなく、
Ｚ^ｉ１及びＺ^ｉ２は、それぞれ独立して、単結合、炭素原子数１～２０のアルキレン基のいずれかを表し、
当該アルキレン基中の１つ又は２つ以上の－ＣＨ_２－は、それぞれ独立して、－Ｏ－、－ＣＦ_２－及び／又は－ＣＯ－で置換されていてもよく、
当該アルキレン基中の１つ又は２つ以上の－ＣＨ_２－ＣＨ_２－は、それぞれ独立して、－ＣＨ_２－ＣＨ（ＣＨ_３）－、－ＣＨ（ＣＨ_３）－ＣＨ_２－、－ＣＨ＝ＣＨ－、－ＣＦ＝ＣＦ－、－ＣＨ＝Ｃ（ＣＨ_３）－、－Ｃ（ＣＨ_３）＝ＣＨ－、－ＣＨ＝Ｎ－、－Ｎ＝ＣＨ－、－Ｎ＝Ｎ－、－Ｃ≡Ｃ－、－ＣＯ－Ｏ－及び／又は－Ｏ－ＣＯ－で置換されてもよく、
酸素原子と酸素原子が直接結合することはなく、
ｎ^ｉ１は、０～３の整数を表すが、
Ａ^ｉ２又はＺ^ｉ２が複数存在する場合は、それらはそれぞれ同一であってもよく、異なっていてもよい。）
で表される化合物。

(In the general formula (i),
R ⁱ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms;
one or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -CO- and/or -CS-;
one or more -CH ₂ -CH ₂ - in the alkyl group may each independently be substituted by -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH-, -NH-CO-, -CH=CH-, -CF=CF- and/or -C≡C-;
One or more hydrogen atoms in the alkyl group may be independently substituted with a halogen atom.
Oxygen atoms do not bond directly to each other,
X ⁱ¹ represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a thioisocyano group, an isothiocyanate group, an isocyanate group, or an alkyl group having 1 to 20 carbon atoms;
one or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -CO- and/or -CS-;
one or more -CH ₂ -CH ₂ - in the alkyl group may each independently be substituted by -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH-, -NH-CO-, -CH=CH-, -CF=CF- and/or -C≡C-;
One or more hydrogen atoms in the alkyl group may be independently substituted with a halogen atom.
Oxygen atoms do not bond directly to each other,
A ⁱ¹ and A ⁱ² each independently represent a hydrocarbon ring having 3 to 16 carbon atoms or a heterocycle having 3 to 16 carbon atoms;
One or more hydrogen atoms in A ⁱ¹ and A ⁱ² may each independently be substituted by a substituent S ⁱ¹ ;
the substituent S ⁱ¹ represents any one of a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a trimethylsilyl group, a dimethylsilyl group, a thioisocyano group, and an alkyl group having 1 to 20 carbon atoms;
One or more -CH ₂ - in the alkyl group may each independently be substituted with -O-, -S- and/or -CO-;
one or more -CH ₂ -CH ₂ - in the alkyl group may each independently be substituted by -CH=CH-, -CF=CF-, -C≡C-, -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH- and/or -NH-CO-;
One or more hydrogen atoms in the alkyl group may be independently substituted with a halogen atom.
Oxygen atoms do not bond directly to each other,
When there are a plurality of substituents S ⁱ¹ , they may be the same or different.
L ⁱ¹ and L ⁱ² each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a trimethylsilyl group, a dimethylsilyl group, a thioisocyano group, or an alkyl group having 1 to 20 carbon atoms;
One or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -CO- and/or -CS-;
one or more -CH ₂ -CH ₂ - in the alkyl group may each independently be substituted by -CH=CH-, -CF=CF-, -C≡C-, -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH- and/or -NH-CO-;
One or more hydrogen atoms in the alkyl group may be independently substituted with a halogen atom.
Oxygen atoms do not bond directly to each other,
Z ⁱ¹ and Z ⁱ² each independently represent a single bond or an alkylene group having 1 to 20 carbon atoms;
one or more -CH ₂ - in the alkylene group may each independently be substituted by -O-, -CF ₂ - and/or -CO-;
one or more -CH ₂ -CH ₂ - in the alkylene group may each independently be replaced by -CH ₂ -CH(CH ₃ )-, -CH(CH ₃ )-CH ₂ -, -CH=CH-, -CF=CF-, -CH=C(CH ₃ )-, -C(CH ₃ )=CH-, -CH=N-, -N=CH-, -N=N-, -C≡C-, -CO-O- and/or -O-CO-;
Oxygen atoms do not bond directly to each other,
n ⁱ¹ represents an integer of 0 to 3,
When a plurality of A ⁱ² or Z ⁱ² are present, they may be the same or different.
A compound represented by the formula:

Item 2. The compound represented by the general formula (i) is represented by the following general formulas (i-1) to (i-11):

（一般式（ｉ－１）～（ｉ－１１）中、
Ｒ^ｉ１、Ｌ^ｉ１、Ｌ^ｉ２、Ａ^ｉ１、Ａ^ｉ２及びＸ^ｉ１は、上記一般式（ｉ）中のＲ^ｉ１、Ｌ^ｉ１、Ｌ^ｉ２、Ａ^ｉ１、Ａ^ｉ２及びＸ^ｉ１とそれぞれ同じ意味を表す。）
で表される化合物からなる群から選ばれる項１に記載の液晶組成物。

(In general formulas (i-1) to (i-11),
R ⁱ¹ , L ⁱ¹ , L ⁱ² , A ⁱ¹ , A ⁱ² and X ⁱ¹ have the same meanings as R ⁱ¹ , L ⁱ¹ , L ⁱ² , A ⁱ¹ , A ⁱ² and X ⁱ¹ in the above general formula (i).
2. The liquid crystal composition according to item 1, wherein the compound is selected from the group consisting of compounds represented by the following formula:

Item 3. The compound according to item 1 or 2, wherein X ⁱ¹ represents a fluorine atom, a cyano group, an isothiocyanate group (-NCS), a linear alkyl group having 1 to 6 carbon atoms, or a linear alkoxy group having 1 to 6 carbon atoms.

Item 4. A liquid crystal composition comprising one or more compounds according to any one of items 1 to 3.

Item 5. A liquid crystal display element using the liquid crystal composition described in item 4.

Item 6. A sensor using the liquid crystal composition described in item 4.

Item 7. A liquid crystal lens using the liquid crystal composition described in item 4.

Item 8. An optical communication device using the liquid crystal composition described in item 4.

Item 9. An antenna using the liquid crystal composition described in item 4.

Item 10. The antenna according to item 9,
a first substrate having a plurality of slots;
a second substrate facing the first substrate and provided with a power supply unit;
a first dielectric layer provided between the first substrate and the second substrate;
A plurality of patch electrodes arranged corresponding to the plurality of slots;
a third substrate on which the patch electrode is provided;
a liquid crystal layer provided between the first substrate and the third substrate;
Item 5. An antenna, wherein the liquid crystal layer contains the liquid crystal composition according to item 4.

According to the present invention, by using a compound represented by general formula (i) having a predetermined side chain structure including an indene structure and an isothiocyanate group (-NCS) group, a liquid crystal composition having large Δn and large Δε _r and having good storage stability at low temperature or room temperature can be obtained, and the liquid crystal composition is useful for liquid crystal display elements, sensors, liquid crystal lenses, optical communication devices and antennas.

(Compound represented by general formula (i))
The compound according to the present invention is a compound represented by the following general formula (i) having a specific side chain structure including an indene structure and an isothiocyanate group (-NCS) group.

In addition, the liquid crystal composition of the present invention contains one or more compounds represented by general formula (i) having a specific side chain structure including an indene structure and an isothiocyanate group (-NCS) group.

In formula (i), the dashed line indicates the position of a double bond.
Specific examples of the indene structure include groups represented by the following general formulae (A ^indene -1) and (A ^indene -2).

In the general formulae (A ^indene -1) to (A ^indene -2), * represents a bond to L ⁱ¹ and L ⁱ² , a white dot represents a bond to R ⁱ¹ , and a black dot represents a bond to Z ⁱ¹ .
As the group represented by the general formula (A ^indene -1), groups represented by the following structural formulae (A ^indene -1-1) to (A ^indene -1-4) are preferable.

In the structural formulae (A ^indene -1-1) to (A ^indene -4), the white dots represent bonds to R ⁱ¹ , and the black dots represent bonds to Z ⁱ¹ .
As the group represented by the general formula (A ^indene -2), groups represented by the following structural formulae (A ^indene -2-1) to (A ^indene -2-4) are preferable.

In the structural formulae (A ^indene -2-1) to (A ^indene -2-4), the white dots represent bonds to R ⁱ¹ , and the black dots represent bonds to Z ⁱ¹ .
The compound represented by the general formula (i) has an indene structure, and therefore while weakening the intermolecular interaction, the π-conjugated bonds are expanded, thereby increasing Δn.
In formula (i), R ⁱ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.
The alkyl group may be a straight-chain, branched or cyclic alkyl group, and is preferably a straight-chain alkyl group.
The alkyl group preferably has 2 to 10, preferably 2 to 6 carbon atoms.
One or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -CO- and/or -CS-.
In addition, one or more -CH ₂ -CH ₂ - in the alkyl group may be each independently substituted by -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH-, -NH-CO-, -CH=CH-, -CF=CF- and/or -C≡C-.
Furthermore, one or more hydrogen atoms in the alkyl group may each independently be substituted with a halogen atom.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. However, when the alkyl group is substituted with a specific group, the oxygen atoms are not directly bonded to each other.
From the viewpoint of the stability of the compound, it is preferable that sulfur atoms and/or oxygen atoms are not directly bonded to each other.
For example, R ⁱ¹ can represent an alkoxy group having 1 to 19 carbon atoms by replacing one --CH ₂ -- in the alkyl group with --O--.
The alkoxy group is a linear, branched or cyclic alkoxy group, and is preferably a linear alkoxy group.
The alkoxy group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, R ⁱ¹ can represent an alkylsulfanyl group (alkylthio group) having 1 to 19 carbon atoms by replacing one --CH ₂ -- in the alkyl group with --S--.
The alkylsulfanyl group is a linear, branched or cyclic alkylsulfanyl group, and is preferably a linear alkylsulfanyl group.
The alkylsulfanyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms.
Furthermore, R ⁱ¹ can represent an alkenyl group having 2 to 20 carbon atoms by replacing one or more -CH ₂ -CH ₂ - in the alkyl group with -CH=CH-.
The alkenyl group is a linear, branched or cyclic alkenyl group, and is preferably a linear alkenyl group.
The alkenyl group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, R ⁱ¹ can represent a halogenated alkyl group having 1 to 20 carbon atoms, in which one or more hydrogen atoms in the alkyl group have been substituted with halogen atoms.
The halogenated alkyl group may be linear, branched or cyclic, and is preferably a linear halogenated alkyl group.
The halogenated alkyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
In addition, R ⁱ¹ can represent a halogenated alkoxy group having 1 to 19 carbon atoms, in which one -CH ₂ - in the alkyl group is replaced with -O-, and one or more hydrogen atoms in the alkyl group are replaced with halogen atoms.
The halogenated alkoxy group may be a linear, branched or cyclic halogenated alkoxy group, and is preferably a linear halogenated alkoxy group.
The halogenated alkoxy group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
Specific examples of the alkyl group having 1 to 20 carbon atoms for R ⁱ¹ (including substituted ones) include groups represented by formulae (R ⁱ¹ -1) to (R ⁱ¹ -39).

In the formulae (R ⁱ¹ -1) to (R ⁱ¹ -39), the black dots represent bonds to the indene structure.
From the viewpoint of solubility, R ⁱ¹ is preferably a linear alkyl group having 1 to 6 carbon atoms, a linear alkoxyalkyl group having 1 to 6 carbon atoms, or a linear alkenyl group having 2 to 6 carbon atoms.

In general formula (i), X ⁱ¹ represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a thioisocyano group, an isothiocyanate group, an isocyanate group, or an alkyl group having 1 to 20 carbon atoms.
The alkyl group may be a straight-chain, branched or cyclic alkyl group, and is preferably a straight-chain alkyl group.
The alkyl group preferably has 2 to 10, preferably 2 to 6 carbon atoms.
One or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -CO- and/or -CS-.
In addition, one or more -CH ₂ -CH ₂ - in the alkyl group may be each independently substituted by -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH-, -NH-CO-, -CH=CH-, -CF=CF- and/or -C≡C-.
Furthermore, one or more hydrogen atoms in the alkyl group may each independently be substituted with a halogen atom.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. However, when the alkyl group is substituted with a specific group, the oxygen atoms are not directly bonded to each other.
From the viewpoint of the stability of the compound, it is preferable that sulfur atoms and/or oxygen atoms are not directly bonded to each other.
For example, X ⁱ¹ can represent an alkoxy group having 1 to 19 carbon atoms by replacing one --CH ₂ -- in the alkyl group with --O--.
The alkoxy group is a linear, branched or cyclic alkoxy group, and is preferably a linear alkoxy group.
The alkoxy group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, X ⁱ¹ can represent an alkylsulfanyl group (alkylthio group) having 1 to 19 carbon atoms by substituting one --CH ₂ -- in the alkyl group with --S--.
The alkylsulfanyl group is a linear, branched or cyclic alkylsulfanyl group, and is preferably a linear alkylsulfanyl group.
The alkylsulfanyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms.
Furthermore, X ⁱ¹ can represent an alkenyl group having 2 to 20 carbon atoms by replacing one or more -CH ₂ -CH ₂ - in the alkyl group with -CH=CH-.
The alkenyl group is a linear, branched or cyclic alkenyl group, and is preferably a linear alkenyl group.
The alkenyl group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, X ⁱ¹ can represent a halogenated alkyl group having 1 to 20 carbon atoms, in which one or more hydrogen atoms in the alkyl group have been substituted with halogen atoms.
The halogenated alkyl group may be linear, branched or cyclic, and is preferably a linear halogenated alkyl group.
The halogenated alkyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
In addition, X ⁱ¹ can represent a halogenated alkoxy group having 1 to 19 carbon atoms, in which one -CH ₂ - in the alkyl group is replaced with -O-, and one or more hydrogen atoms in the alkyl group are replaced with halogen atoms.
The halogenated alkoxy group may be a linear, branched or cyclic halogenated alkoxy group, and is preferably a linear halogenated alkoxy group.
The halogenated alkoxy group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
Specific examples of the alkyl group having 1 to 20 carbon atoms for X ⁱ¹ (including substituted ones) include groups represented by formulae (X ⁱ¹ -1) to (X ⁱ¹ -39).

In formulae (X ⁱ¹ -1) to (X ⁱ¹ -39), the black dot represents a bond to A ⁱ¹ or A ⁱ² .
From the viewpoints of Δn and viscosity in the long wavelength and high frequency regions, it is preferable that X ⁱ¹ represents a fluorine atom, a cyano group, an isothiocyanate group (-NCS), a linear alkyl group having 1 to 6 carbon atoms, or a linear alkoxy group having 1 to 6 carbon atoms.

In formula (i), A ⁱ¹ and A ⁱ² each independently represent a hydrocarbon ring having 3 to 16 carbon atoms or a heterocycle having 3 to 16 carbon atoms.
More specifically, the hydrocarbon ring having 3 to 16 carbon atoms or the heterocycle having 3 to 16 carbon atoms is the following group (a), group (b), group (c), and group (d):
(a) a 1,4-cyclohexylene group (in which one —CH ₂ — or two or more non-adjacent —CH ₂ — groups may be replaced by —O— or —S—).
(b) a 1,4-phenylene group (in which one -CH= or two or more non-adjacent -CH= groups may be replaced by -N=).
(c) 1,4-cyclohexenylene group, bicyclo[2.2.2]octane-1,4-diyl group, naphthalene-2,6-diyl group, naphthalene-1,4-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, 5,6,7,8-tetrahydronaphthalene-1,4-diyl group, decahydronaphthalene-2,6-diyl group, anthracene-2,6-diyl group, anthracene-1,4-diyl group, anthracene-9,10-diyl group, phenanthracene-2,6-diyl group, anthracene-1,4-diyl group, anthracene-9,10-diyl group, a naphthalene-2,7-diyl group (one -CH= or two or more -CH= present in a naphthalene-2,6-diyl group, a naphthalene-1,4-diyl group, a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, a 5,6,7,8-tetrahydronaphthalene-1,4-diyl group, an anthracene-2,6-diyl group, an anthracene-1,4-diyl group, an anthracene-9,10-diyl group, or a phenanthrene-2,7-diyl group may be replaced by -N=);
(d) a thiophene-2,5-diyl group, a benzothiophene-2,5-diyl group, a benzothiophene-2,6-diyl group, a dibenzothiophene-3,7-diyl group, a dibenzothiophene-2,6-diyl group, or a thieno[3,2-b]thiophene-2,5-diyl group (one -CH= or two or more non-adjacent -CH= in this group may be replaced by -N=).
It is preferred that the aryl group represents a group selected from the group consisting of:

One or more hydrogen atoms in A ⁱ¹ and A ⁱ² may each independently be substituted with a substituent S ⁱ¹ .
The substituent S ⁱ¹ represents any one of a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a trimethylsilyl group, a dimethylsilyl group, a thioisocyano group, and an alkyl group having 1 to 20 carbon atoms.
The alkyl group may be a straight-chain, branched or cyclic alkyl group, and is preferably a straight-chain alkyl group.
The alkyl group preferably has 2 to 10, preferably 3 to 6, carbon atoms.
One or more -CH ₂ - in the alkyl group may each independently be substituted with -O-, -S- and/or -CO-.
Furthermore, one or more -CH ₂ -CH ₂ - in the alkyl group may be each independently substituted by -CH=CH-, -CF=CF-, -C≡C-, -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH- and/or -NH-CO-.
One or more hydrogen atoms in the alkyl group may each independently be substituted with a halogen atom.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
However, when the alkyl group is substituted with a specific group, the oxygen atoms are not directly bonded to each other.
From the viewpoint of the stability of the compound, it is preferable that sulfur atoms and/or oxygen atoms are not directly bonded to each other.
The substituent S ⁱ¹ is preferably a linear alkyl group having 1 to 10 carbon atoms, a chlorine atom, or a fluorine atom.
In addition, at least one of A ⁱ¹ and A ⁱ² is preferably substituted with at least one substituent S ⁱ¹ .
Also, A ⁱ² is preferably substituted with at least one substituent S ⁱ¹ .
When there are a plurality of substituents S ⁱ¹ , they may be the same or different.

The substitution position of the substituent S ⁱ¹ in A ⁱ¹ is preferably any one of the following formulae (A ⁱ¹ -SP-1) to (A ⁱ¹ -SP-4).

In the formulae (A ⁱ¹ -SP-1) to (A ⁱ¹ -SP-4), a white dot represents a bond to Z ⁱ¹ , and a black dot represents a bond to Z ⁱ² or X ⁱ¹ .
The substitution position of the substituent S ⁱ¹ in A ⁱ² is preferably any one of the following formulae (A ⁱ² -SP-1) to (A ⁱ² -SP-4).

In the formulae (A ⁱ² -SP-1) to (A ⁱ² -SP-4), a white dot represents a bond to Z ⁱ² , and a black dot represents a bond to Z ⁱ² or X ⁱ¹ .
More specifically, A ⁱ¹ preferably represents any one of the following formulae (A ⁱ¹ -1) to (A ⁱ¹ -13).

In the formulae (A ⁱ¹ -1) to (A ⁱ¹ -13), a white dot represents a bond to Z ⁱ¹ , and a black dot represents a bond to Z ⁱ² or X ⁱ¹ .
More specifically, A ⁱ² preferably represents any one of the following formulas (A ⁱ² -1) to (A ⁱ² -10).

In the formulae (A ⁱ² -1) to (A ⁱ² -10), a white dot represents a bond to Z ⁱ² , and a black dot represents a bond to Z ⁱ² or X ⁱ¹ .

In general formula (i), L ⁱ¹ and L ⁱ² each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a trimethylsilyl group, a dimethylsilyl group, a thioisocyano group, or an alkyl group having 1 to 20 carbon atoms.
The alkyl group having 1 to 20 carbon atoms may be a straight-chain, branched or cyclic alkyl group, and is preferably a straight-chain alkyl group.
The alkyl group having 1 to 20 carbon atoms preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
One or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -CO- and/or -CS-.
Furthermore, one or more -CH ₂ -CH ₂ - in the alkyl group may be each independently substituted by -CH=CH-, -CF=CF-, -C≡C-, -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH- and/or -NH-CO-.
Furthermore, one or more hydrogen atoms in the alkyl group may each independently be substituted with a halogen atom.
Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.
However, when the alkyl group is substituted with a specific group, the oxygen atoms are not directly bonded to each other.
From the viewpoint of the stability of the compound, it is preferable that sulfur atoms and/or oxygen atoms are not directly bonded to each other.
For example, L ⁱ¹ and L ⁱ² can represent an alkoxy group having 1 to 19 carbon atoms by replacing one --CH ₂ -- in the alkyl group with --O--.
The alkoxy group is a linear, branched or cyclic alkoxy group, and is preferably a linear alkoxy group.
The alkoxy group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, L ⁱ¹ and L ⁱ² can represent an alkylsulfanyl group (alkylthio group) having 1 to 19 carbon atoms by replacing one --CH ₂ -- in the alkyl group with --S--.
The alkylsulfanyl group is a linear, branched or cyclic alkylsulfanyl group, and is preferably a linear alkylsulfanyl group.
The alkylsulfanyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
Furthermore, L ⁱ¹ and L ⁱ² can represent an alkenyl group having 2 to 20 carbon atoms by replacing one or more -CH ₂ -CH ₂ - in the alkyl group with -CH=CH-.
The alkenyl group is a linear, branched or cyclic alkenyl group, and is preferably a linear alkenyl group.
The alkenyl group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, L ⁱ¹ and L ⁱ² can represent an alkynyl group having 2 to 20 carbon atoms by replacing one or more -CH ₂ -CH ₂ - in the alkyl group with -C≡C-.
The alkynyl group may be a linear, branched or cyclic alkynyl group, and is preferably a linear alkynyl group.
The alkynyl group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
In addition, L ⁱ¹ and L ⁱ² can represent an alkenyloxy group having 2 to 19 carbon atoms in which one —CH ₂ — in the alkyl group is replaced with —O— and one or more —CH ₂ —CH ₂ — are replaced with —CH═CH—.
The alkenyloxy group is a linear, branched or cyclic alkenyloxy group, and is preferably a linear alkenyloxy group.
The alkenyloxy group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, L ⁱ¹ and L ⁱ² can represent a halogenated alkyl group having 1 to 20 carbon atoms, in which one or more hydrogen atoms in the alkyl group have been substituted with halogen atoms.
The halogenated alkyl group may be linear, branched or cyclic, and is preferably a linear halogenated alkyl group.
The halogenated alkyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
In addition, L ⁱ¹ and L ⁱ² can represent a halogenated alkoxy group having 1 to 19 carbon atoms in which one -CH ₂ - in the alkyl group is replaced with -O- and one or more hydrogen atoms in the alkyl group are replaced with halogen atoms.
The halogenated alkoxy group may be a linear, branched or cyclic halogenated alkoxy group, and is preferably a linear halogenated alkoxy group.
The halogenated alkoxy group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.

Specific examples of the alkyl group having 1 to 20 carbon atoms (including substituted ones) in L ⁱ¹ and L ⁱ² include groups represented by the formulae (L ^i1/2 -1) to (L ^i1/2 -36).

In the formulae (L ^i1/2 -1) to (L ^i1/2 -36), the black dots represent bonds to the indene structure.
From the viewpoint of solubility and viscosity, at least one of L ⁱ¹ and L ⁱ² is preferably a hydrogen atom, a fluorine atom, or a linear alkyl group having 1 to 6 carbon atoms, and it is more preferable that L ⁱ¹ and L ⁱ² are a hydrogen atom or a fluorine atom.

In formula (i), Z ⁱ¹ and Z ⁱ² each independently represent a single bond or an alkylene group having 1 to 20 carbon atoms.
The alkylene group is a linear, branched or cyclic alkylene group, and is preferably a linear alkylene group.
The alkylene group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
One or more -CH ₂ - in the alkylene group may each independently be substituted with -O-, -CF ₂ - and/or -CO-.
Furthermore, one or more -CH ₂ -CH ₂ - in the alkylene group may each independently be substituted with -CH ₂ -CH(CH ₃ )-, -CH(CH ₃ )-CH ₂ -, -CH=CH-, -CF=CF-, -CH=C(CH ₃ )-, -C(CH ₃ )=CH-, -CH=N-, -N=CH-, -N=N-, -C≡C-, -CO-O- and/or -O-CO-.
However, when the alkylene group is substituted with a specific group, the oxygen atoms are not directly bonded to each other.
Specific examples of the alkylene group having 2 to 20 carbon atoms (including substituted ones) include groups represented by the formulae (Z ^i1/2 -1) to (Z ^i1/2 -24).

In the formulae (Z ^i1/2 -1) to (Z ^i1/2 -24), the white dots represent an indene structure, a bond to A ⁱ¹ or A ⁱ² , and the black dots represent a bond to A ⁱ¹ or A ⁱ² .
From the viewpoint of Δn, it is preferable that Z ⁱ¹ and Z ⁱ² each independently represent a single bond, —CH ₂ —CH ₂ —, —CO—O—, —N═N—, —N═CH—, —CH═CH— or —C≡C—.
From the viewpoint of Δn, it is preferable that at least one of Z ⁱ¹ and Z ⁱ² is -C≡C-.

In formula (i), n ⁱ¹ represents an integer of 0 to 3, preferably an integer of 1 or 2.
When a plurality of A ⁱ² or Z ⁱ² are present, they may be the same or different.

As the compound represented by general formula (i), it is preferable to use compounds represented by the following general formulas (i-1) to (i-11).

In the general formulas (i-1) to (i-11), R ⁱ¹ , L ⁱ¹ , L ⁱ² , A ⁱ¹ , A ⁱ² and X ⁱ¹ have the same meanings as R ⁱ¹ , L ⁱ¹ , L ⁱ² , A ⁱ¹ , A ⁱ² and X ⁱ¹ in the general formula (i), respectively, and the preferred groups are also the same.

As the compound represented by general formula (i-1), it is preferable to use compounds represented by the following general formulas (i-1-1) to (i-1-19).

In formulae (i-1-1) to (i-1-19), R ⁱ¹ , X ⁱ¹ and S ⁱ¹ have the same meanings as R ⁱ¹ , X ⁱ¹ and S ⁱ¹ in formula (i), respectively, and the preferred groups are also the same.
Specific examples of the compound represented by general formula (i-1-1) include compounds represented by the following structural formulas (i-1-1.1) to (i-1-1.10).

Specific examples of the compound represented by general formula (i-1-2) include the compounds represented by the following structural formulas (i-1-2.1) to (i-1-2.5).

Specific examples of the compound represented by general formula (i-1-3) include the compounds represented by the following structural formulas (i-1-3.1) to (i-1-3.6).

Specific examples of the compound represented by general formula (i-1-4) include the compounds represented by the following structural formulas (i-1-4.1) to (i-1-4.6).

Specific examples of the compound represented by general formula (i-1-5) include compounds represented by the following structural formulas (i-1-5.1) to (i-1-5.5).

Specific examples of the compound represented by general formula (i-1-6) include the compounds represented by the following structural formulas (i-1-6.1) to (i-1-6.6).

Specific examples of the compound represented by general formula (i-1-7) include the compounds represented by the following structural formulas (i-1-7.1) to (i-1-7.4).

Specific examples of the compound represented by general formula (i-1-8) include the compounds represented by the following structural formulas (i-1-8.1) to (i-1-8.5).

Specific examples of the compound represented by general formula (i-1-9) include the compounds represented by the following structural formulas (i-1-9.1) to (i-1-9.4).

Specific examples of the compound represented by general formula (i-1-10) include the compounds represented by the following structural formulas (i-1-10.1) to (i-1-10.2).

Specific examples of the compound represented by general formula (i-1-11) include the compounds represented by the following structural formulas (i-1-11.1) to (i-1-11.6).

Specific examples of the compound represented by general formula (i-1-12) include the compounds represented by the following structural formulas (i-1-12.1) to (i-1-12.6).

Specific examples of the compound represented by general formula (i-1-13) include the compounds represented by the following structural formulas (i-1-13.1) to (i-1-13.4).

Specific examples of the compound represented by general formula (i-1-14) include the compounds represented by the following structural formulas (i-1-14.1) to (i-1-14.4).

Specific examples of compounds represented by general formula (i-1-15) include compounds represented by the following structural formula (i-1-15.1).

Specific examples of compounds represented by general formula (i-1-16) include compounds represented by the following structural formula (i-1-16.1).

Specific examples of compounds represented by general formula (i-1-17) include compounds represented by the following structural formula (i-1-17.1).

Specific examples of compounds represented by general formula (i-1-18) include compounds represented by the following structural formula (i-1-18.1).

Specific examples of compounds represented by general formula (i-1-19) include compounds represented by the following structural formula (i-1-19.1).

As the compound represented by general formula (i-2), it is preferable to use compounds represented by the following general formulas (i-2-1) to (i-2-7).

In the general formulae (i-2-1) to (i-2-7), R ⁱ¹ , X ⁱ¹ and S ⁱ¹ have the same meanings as R ⁱ¹ , X ⁱ¹ and S ⁱ¹ in the above general formula (i), respectively, and the preferred groups are also the same.
Specific examples of the compound represented by general formula (i-2-1) include compounds represented by the following structural formulas (i-2-1.1) to (i-2-1.6).

Specific examples of the compound represented by general formula (i-2-2) include the compounds represented by the following structural formulas (i-2-2.1) to (i-2-2.4).

Specific examples of the compound represented by general formula (i-2-3) include the compounds represented by the following structural formulas (i-2-3.1) to (i-2-3.4).

Specific examples of the compound represented by general formula (i-2-4) include the compounds represented by the following structural formulas (i-2-4.1) to (i-2-4.6).

Specific examples of the compound represented by general formula (i-2-5) include compounds represented by the following structural formulas (i-2-5.1) to (i-2-5.5).

Specific examples of the compound represented by general formula (i-2-6) include the compounds represented by the following structural formulas (i-2-6.1) to (i-2-6.4).

Specific examples of the compound represented by general formula (i-2-7) include the compounds represented by the following structural formulas (i-2-7.1) to (i-2-7.4).

As the compound represented by general formula (i-3), it is preferable to use compounds represented by the following general formulas (i-3-1) to (i-3-10).

In formulae (i-3-1) to (i-3-10), R ⁱ¹ , X ⁱ¹ and S ⁱ¹ have the same meanings as R ⁱ¹ , X ⁱ¹ and S ⁱ¹ in formula (i), respectively, and the preferred groups are also the same.

Specific examples of the compound represented by general formula (i-3-1) include the compounds represented by the following structural formulas (i-3-1.1) to (i-3-1.6).

Specific examples of the compound represented by general formula (i-3-2) include the compounds represented by the following structural formulas (i-3-2.1) to (i-3-2.6).

Specific examples of the compound represented by general formula (i-3-3) include the compounds represented by the following structural formulas (i-3-3.1) to (i-3-3.6).

Specific examples of the compound represented by general formula (i-3-4) include compounds represented by the following structural formulas (i-3-4.1) to (i-3-4.4).

Specific examples of the compound represented by general formula (i-3-5) include the compounds represented by the following structural formulas (i-3-5.1) to (i-3-5.4).

Specific examples of the compound represented by general formula (i-3-6) include the compounds represented by the following structural formulas (i-3-6.1) to (i-3-6.6).

Specific examples of the compound represented by general formula (i-3-7) include the compound represented by the following structural formula (i-3-7.1).

Specific examples of compounds represented by general formula (i-3-8) include compounds represented by the following structural formula (i-3-8.1).

Specific examples of compounds represented by general formula (i-3-9) include compounds represented by the following structural formula (i-3-9.1).

Specific examples of compounds represented by general formula (i-3-10) include compounds represented by the following structural formula (i-3-10.1).

As the compound represented by general formula (i-4), it is preferable to use compounds represented by the following general formulas (i-4-1) to (i-4-6).

Specific examples of the compound represented by general formula (i-4-1) include the compounds represented by the following structural formulas (i-4-1.1) to (i-4-1.4).

Specific examples of the compound represented by general formula (i-4-2) include the compounds represented by the following structural formulas (i-4-2.1) to (i-4-2.4).

Specific examples of the compound represented by general formula (i-4-3) include the compounds represented by the following structural formulas (i-4-3.1) to (i-4-3.4).

Specific examples of the compound represented by general formula (i-4-4) include the compounds represented by the following structural formulas (i-4-4.1) to (i-4-4.4).

Specific examples of the compound represented by general formula (i-4-5) include the compound represented by the following structural formula (i-4-5.1).

Specific examples of compounds represented by general formula (i-4-6) include compounds represented by the following structural formula (i-4-6.1).

As the compound represented by general formula (i-5), it is preferable to use compounds represented by the following general formulas (i-5-1) to (i-5-4).

In the general formulae (i-5-1) to (i-5-4), R ⁱ¹ , X ⁱ¹ and S ⁱ¹ have the same meanings as R ⁱ¹ , X ⁱ¹ and S ⁱ¹ in the above general formula (i), respectively, and the preferred groups are also the same.

Specific examples of the compound represented by general formula (i-5-1) include the compounds represented by the following structural formulas (i-5-1.1) to (i-5-1.4).

Specific examples of the compound represented by general formula (i-5-2) include the compounds represented by the following structural formulas (i-5-2.1) to (i-5-2.4).

Specific examples of the compound represented by general formula (i-5-3) include the compounds represented by the following structural formulas (i-5-3.1) to (i-5-3.4).

Specific examples of the compound represented by general formula (i-5-4) include the compounds represented by the following structural formulas (i-5-4.1) to (i-5-4.4).

As the compound represented by general formula (i-6), it is preferable to use compounds represented by the following general formulas (i-6-1) to (i-6-4).

In the general formulae (i-6-1) to (i-6-4), R ⁱ¹ , X ⁱ¹ and S ⁱ¹ have the same meanings as R ⁱ¹ , X ⁱ¹ and S ⁱ¹ in the above general formula (i), respectively, and the preferred groups are also the same.

Specific examples of the compound represented by general formula (i-6-1) include the compounds represented by the following structural formulas (i-6-1.1) to (i-6-1.4).

Specific examples of the compound represented by general formula (i-6-2) include the compounds represented by the following structural formulas (i-6-2.1) to (i-6-2.4).

Specific examples of the compound represented by general formula (i-6-3) include the compounds represented by the following structural formulas (i-6-3.1) to (i-6-3.4).

Specific examples of the compound represented by general formula (i-6-4) include the compounds represented by the following structural formulas (i-6-4.1) to (i-6-4.4).

As the compound represented by general formula (i-7), it is preferable to use compounds represented by the following general formulas (i-7-1) to (i-7-4).

In the general formulae (i-7-1) to (i-7-4), R ⁱ¹ , X ⁱ¹ and S ⁱ¹ have the same meanings as R ⁱ¹ , X ⁱ¹ and S ⁱ¹ in the above general formula (i), respectively, and the preferred groups are also the same.

Specific examples of the compound represented by general formula (i-7-1) include the compounds represented by the following structural formulas (i-7-1.1) to (i-7-1.4).

Specific examples of the compound represented by general formula (i-7-2) include the compounds represented by the following structural formulas (i-7-2.1) to (i-7-2.4).

Specific examples of the compound represented by general formula (i-7-3) include the compounds represented by the following structural formulas (i-7-3.1) to (i-7-3.4).

Specific examples of the compound represented by general formula (i-7-4) include the compounds represented by the following structural formulas (i-7-4.1) to (i-7-4.4).

As the compound represented by general formula (i-8), it is preferable to use the compounds represented by the following general formulas (i-8-1) to (i-8-2).

In the general formulae (i-8-1) to (i-8-2), R ⁱ¹ , X ⁱ¹ and S ⁱ¹ have the same meanings as R ⁱ¹ , X ⁱ¹ and S ⁱ¹ in the above general formula (i), respectively, and the preferred groups are also the same.

Specific examples of the compound represented by general formula (i-8-1) include compounds represented by the following structural formulas (i-8-1.1) to (i-8-1.2).

Specific examples of the compound represented by general formula (i-8-2) include the compounds represented by the following structural formulas (i-8-2.1) to (i-8-2.2).

As the compound represented by general formula (i-9), it is preferable to use compounds represented by the following general formulas (i-9-1) to (i-9-4).

In the general formulae (i-9-1) to (i-9-4), R ⁱ¹ , X ⁱ¹ and S ⁱ¹ have the same meanings as R ⁱ¹ , X ⁱ¹ and S ⁱ¹ in the above general formula (i), respectively, and the preferred groups are also the same.

Specific examples of the compound represented by general formula (i-9-1) include the compounds represented by the following structural formulas (i-9-1.1) to (i-9-1.4).

Specific examples of the compound represented by general formula (i-9-2) include the compounds represented by the following structural formulas (i-9-2.1) to (i-9-2.4).

Specific examples of the compound represented by general formula (i-9-3) include the compounds represented by the following structural formulas (i-9-3.1) to (i-9-3.4).

Specific examples of the compound represented by general formula (i-9-4) include the compounds represented by the following structural formulas (i-9-4.1) to (i-9-4.4).

As the compound represented by general formula (i-10), it is preferable to use compounds represented by the following general formulas (i-10-1) to (i-10-2).

In formulae (i-10-1) to (i-10-2), R ⁱ¹ , X ⁱ¹ and S ⁱ¹ have the same meanings as R ⁱ¹ , X ⁱ¹ and S ⁱ¹ in formula (i), respectively, and the preferred groups are also the same.

Specific examples of the compound represented by general formula (i-10-1) include compounds represented by the following structural formulas (i-10-1.1) to (i-10-1.2).

Specific examples of the compound represented by general formula (i-10-2) include the compounds represented by the following structural formulas (i-10-2.1) to (i-10-2.2).

As the compound represented by general formula (i-11), it is preferable to use the compounds represented by the following general formulas (i-11-1) to (i-11-2).

In formulae (i-11-1) to (i-11-2), R ⁱ¹ , X ⁱ¹ and S ⁱ¹ have the same meanings as R ⁱ¹ , X ⁱ¹ and S ⁱ¹ in formula (i), respectively, and the preferred groups are also the same.

Specific examples of the compound represented by general formula (i-11-1) include compounds represented by the following structural formulas (i-11-1.1) to (i-11-1.2).

Specific examples of the compound represented by general formula (i-11-2) include compounds represented by the following structural formulas (i-11-2.1) to (i-11-2.2).

General formula (i), general formulas (i-1) to (i-11), general formulas (i-1-1) to (i-1-19), general formulas (i-2-1) to (i -2-7), general formulae (i-3-1) to (i-3-10), general formulae (i-4-1) to (i-4-6), general formula (i-5-1 ) to (i-5-4), general formulae (i-6-1) to (i-6-4), general formulae (i-7-1) to (i-7-4), general formula (i -8-1) to (i-8-2), general formulas (i-9-1) to (i-9-4), general formulas (i-10-1) to (i- 10-2), general formulas (i-11-1) to (i-11-2), structural formulas (i-1-1.1) to (i-1-1.10), structural formula (i- 1-2.1) to (i-1-2.5), structural formulas (i-1-3.1) to (i-1-3.6), structural formula (i-1-4.1) ~ (i-1-4.6), structural formulas (i-1-5.1) ~ (i-1-5.5), structural formulas (i-1-6.1) ~ (i-1- 6.6), structural formulas (i-1-7.1) to (i-1-7.4), structural formulas (i-1-8.1) to (i-1-8.5) , structural formulae (i-1-9.1) to (i-1-9.4), structural formulae (i-1-10.1) to (i-1-10.2), structural formulae (i- 1-11.1) to (i-1-11.6), structural formulas (i-1-12.1) to (i-1-12.6), structural formula (i-1-13.1) ~ (i-1-13.4), structural formula (i-1-14.1) ~ (i-1-14.4), structural formula (i-1-15.1), structural formula (i- 1-16.1), structural formula (i-1-17.1), structural formula (i-1-18.1), structural formula (i- 1-19.1), structural formulas (i-2-1.1) to (i-2-1.6), structural formulas (i-2-2.1) to (i-2-2.4) , structural formulae (i-2-3.1) to (i-2-3.4), structural formulae (i-2-4.1) to (i-2-4.6), structural formulae (i- 2-5.1) to (i-2-5.5), structural formulas (i-2-6.1) to (i-2-6.4), structural formula (i-2-7.1) ~ (i-2-7.4), structural formulas (i-3-1.1) ~ (i-3-1.6), structural formulas (i-3-2.1) ~ (i-3- 2. 6), structural formulae (i-3-3.1) to (i-3-3.6), structural formulae (i-3-4.1) to (i-3-4.4), structural formulae ( i-3-5.1) to (i-3-5.4), structural formulas (i-3-6.1) to (i-3-6.6), structural formula (i-3-7. 1), structural formula (i-3-8.1), structural formula (i-3-9.1), structural formula (i-3-10.1), structural formula (i-4-1.1) ~ (i-4-1.4), structural formulas (i-4-2.1) ~ (i-4-2.4), structural formulas (i-4-3.1) ~ (i-4 -3.4), structural formulas (i-4-4.1) to (i-4-4.4), structural formula (i-4-5.1), structural formula (i-4-6.1 ), structural formulae (i-5-1.1) to (i-5-1.4), structural formulae (i-5-2.1) to (i-5-2.4), structural formula (i -5-3.1) to (i-5-3.4), structural formulas (i-5-4.1) to (i-5-4.4), structural formula (i-6-1.1 ) to (i-6-1.4), structural formulas (i-6-2.1) to (i-6-2.4), structural formulas (i-6-3.1) to (i-6 - 3.4), structural formulas (i-6-4.1) to (i-6-4.4), structural formulas (i-7-1.1) to (i-7-1.4), structure Formulae (i-7-2.1) to (i-7-2.4), structural formulae (i-7-3.1) to (i-7-3.4), structural formula (i-7- 4.1) to (i-7-4.4), structural formulas (i-8-1.1) to (i-8-1.2), structural formulas (i-8-2.1) to ( i-8-2.2), structural formulas (i-9-1.1) to (i-9-1.4), structural formulas (i-9-2.1) to (i-9-2. 4) , structural formulae (i-9-3.1) to (i-9-3.4), structural formulae (i-9-4.1) to (i-9-4.4), structural formulae (i- 10-1.1) to (i-10-1.2), structural formulas (i-10-2.1) to (i-10-2.2), structural formula (i-11-1.1) The compounds represented by the structural formulae (i-11-1.2) to (i-11-2.1) and (i-11-2.2) may be used in the liquid crystal composition in one or two kinds. The number of species is preferably 1 to 10, more preferably 1 to 5, and still more preferably 1 to 3.

General formula (i), general formulas (i-1) to (i-11), general formulas (i-1-1) to (i-1-19), general formulas (i-2-1) to (i -2-7), general formulae (i-3-1) to (i-3-10), general formulae (i-4-1) to (i-4-6), general formula (i-5-1 ) to (i-5-4), general formulae (i-6-1) to (i-6-4), general formulae (i-7-1) to (i-7-4), general formula (i -8-1) to (i-8-2), general formulas (i-9-1) to (i-9-4), general formulas (i-10-1) to (i-10-2) , general formulae (i-11-1) to (i-11-2), structural formulae (i-1-1.1) to (i-1-1.10), structural formula (i-1-2. 1) to (i-1-2.5), structural formulas (i-1-3.1) to (i-1-3.6), structural formulas (i-1-4.1) to (i- 1-4.6), structural formulas (i-1-5.1) to (i-1-5.5), structural formulas (i-1-6.1) to (i-1-6.6) , structural formulae (i-1-7.1) to (i-1-7.4), structural formulae (i-1-8.1) to (i-1-8.5), structural formula (i- 1-9 . 1) to (i-1-9.4), structural formulas (i-1-10.1) to (i-1-10.2), structural formulas (i-1-11.1) to (i -1-11.6), structural formulas (i-1-12.1) to (i-1-12.6), structural formulas (i-1-13.1) to (i-1-13.4) ), structural formula (i-1-14.1) to (i-1-14.4), structural formula (i-1-15.1), structural formula (i-1-16.1), structural formula (i-1-17.1), structural formula (i-1-18.1), structural formula (i-1-19.1), structural formula (i-2 -1.1) to (i-2-1.6), structural formulas (i-2-2.1) to (i-2-2.4), structural formulas (i-2-3.1) to (i-2-3.4), structural formulas (i-2-4.1) to (i-2-4.6), structural formulas (i-2-5.1) to (i-2-5 .5), structural formulas (i-2-6.1) to (i-2-6.4), structural formulas (i-2-7.1) to (i-2-7.4), structural formula (i-3-1.1) to (i-3-1.6), structural formulas (i-3-2.1) to (i-3-2.6), structural formula (i-3-3 . 1) to (i-3 -3.6), structural formulas (i-3-4.1) to (i-3-4.4), structural formulas (i-3-5.1) to (i-3-5.4), Structural formulae (i-3-6.1) to (i-3-6.6), structural formula (i-3-7.1), structural formula (i-3-8.1), structural formula (i -3-9.1), structural formula (i-3-10.1), structural formula (i-4-1.1) to (i-4-1.4), structural formula (i-4-2 . 1) to (i-4-2.4), structural formulas (i-4-3.1) to (i-4-3.4), structural formulas (i-4-4.1) to (i -4-4 . 4), structural formula (i-4-5.1), structural formula (i-4-6.1), structural formula (i-5-1.1) to (i-5-1.4), Structural formulae (i-5-2.1) to (i-5-2.4), structural formulae (i-5-3.1) to (i-5-3.4), structural formula (i-5 -4.1) to (i-5-4.4), structural formulas (i-6-1.1) to (i-6-1.4), structural formulas (i-6-2.1) to (i-6-2.4), structural formulas (i-6-3.1) to (i-6-3.4), structural formulas (i-6-4.1) to (i-6-4 4) Structure Formulae (i-7-1.1) to (i-7-1.4), structural formulae (i-7-2.1) to (i-7-2.4), structural formula (i-7- 3.1) to (i-7-3.4), structural formulas (i-7-4.1) to (i-7-4.4), structural formulas (i-8-1.1) to ( i-8-1.2), structural formulas (i-8-2.1) to (i-8-2.2), structural formulas (i-9-1.1) to (i-9-1. 4), structural formulae (i-9-2.1) to (i-9-2.4), structural formulae (i-9-3.1) to (i-9-3.4), structural formulae (i-9-2.3) to (i-9-2.4), i-9-4.1 ) to (i-9-4.4), structural formulas (i-10-1.1) to (i-10-1.2), structural formulas (i-10-2.1) to (i-10 -2.2), structural formula (i-11-1.1) to (i-11-1.2) or structural formula (i-11-2.1) to (i-11-2.2) The lower limit of the total content of the compounds represented by the formula (I) in 100% by mass of the liquid crystal composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. It is preferable that the content is 5% by mass or more.

General formula (i), general formulas (i-1) to (i-11), general formulas (i-1-1) to (i-1-19), general formulas (i-2-1) to (i -2-7), general formulae (i-3-1) to (i-3-10), general formulae (i-4-1) to (i-4-6), general formula (i-5-1 ) to (i-5-4), general formulae (i-6-1) to (i-6-4), general formulae (i-7-1) to (i-7-4), general formula (i -8-1) to (i-8-2), general formulas (i-9-1) to (i-9-4), general formulas (i-10-1) to (i-10-2), General formula (i-11-1) to (i-11-2), structural formulas (i-1-1.1) to (i-1-1.10), structural formulas (i-1-2.1) to (i-1-2.5), structural formulas (i-1-3.1) to (i-1-3.6), structural formulas (i-1-4.1) to (i-1-4 .6), structural formulas (i-1-5.1) to (i-1-5.5), structural formulas (i-1-6.1) to (i-1-6.6), structural formula (i-1-7.1) to (i-1-7.4), structural formulas (i-1-8.1) to (i-1-8.5), structural formula (i-1-9 . 1) to (i-1- 9.4), structural formulas (i-1-10.1) to (i-1-10.2), structural formulas (i-1-11.1) to (i-1-11.6), structure Formulae (i-1-12.1) to (i-1-12.6), structural formulae (i-1-13.1) to (i-1-13.4), structural formula (i-1- 14.1) to (i-1-14.4), structural formula (i-1-15.1), structural formula (i-1-16.1), structural formula (i-1-17.1) , structural formula (i-1-18.1), structural formula (i-1-19.1), structural formula (i-2-1.1) to (i-2-1.6) ), structural formulae (i-2-2.1) to (i-2-2.4), structural formulae (i-2-3.1) to (i-2-3.4), structural formulae (i -2-4.1) to (i-2-4.6), structural formulas (i-2-5.1) to (i-2-5.5), structural formula (i-2-6.1) ) to (i-2-6.4), structural formulas (i-2-7.1) to (i-2-7.4), structural formulas (i-3-1.1) to (i-3 -1.6), structural formulas (i-3-2.1) to (i-3-2.6), structural formulas (i-3-3.1) to (i-3-3.6), Structural Formula (i-3-4.1) ~ (i-3-4.4), structural formulas (i-3-5.1) ~ (i-3-5.4), structural formulas (i-3-6.1) ~ (i-3- 6.6), structural formula (i-3-7.1), structural formula (i-3-8.1), structural formula (i-3-9.1), structural formula (i-3-10. 1), structural formulae (i-4-1.1) to (i-4-1.4), structural formulae (i-4-2.1) to (i-4-2.4), structural formulae ( i-4-3.1) to (i-4-3.4), structural formulas (i-4-4.1) to (i-4-4.4), structural formula (i-4-5. 1), structural formula (i -4-6.1), structural formulas (i-5-1.1) to (i-5-1.4), structural formulas (i-5-2.1) to (i-5-2.4) ), structural formulae (i-5-3.1) to (i-5-3.4), structural formulae (i-5-4.1) to (i-5-4.4), structural formula (i -6-1.1) to (i-6-1.4), structural formulas (i-6-2.1) to (i-6-2.4), structural formula (i-6-3.1 ) to (i-6-3.4), structural formulas (i-6-4.1) to (i-6-4.4), structural formulas (i-7-1.1) to (i-7 -1.4), structural formula (i- 7-2.1) to (i-7-2.4), structural formulas (i-7-3.1) to (i-7-3.4), structural formula (i-7-4.1) ~ (i-7-4.4), structural formulas (i-8-1.1) ~ (i-8-1.2), structural formulas (i-8-2.1) ~ (i-8- 2.2), structural formulas (i-9-1.1) to (i-9-1.4), structural formulas (i-9-2.1) to (i-9-2.4), structure Formulae (i-9-3.1) to (i-9-3.4), structural formulae (i-9-4.1) to (i-9-4.4), structural formula (i-10- 1.1) to (i-10- 1.2), structural formulae (i-10-2.1) to (i-10-2.2), structural formulae (i-11-1.1) to (i-11-1.2), or structure The upper limit of the total content of the compounds represented by formulae (i-11-2.1) to (i-11-2.2) in 100% by mass of the liquid crystal composition is 95% by mass or less. It is preferably 90% by mass or less, more preferably 85% by mass or less, more preferably 30% by mass or less, more preferably 20% by mass or less, and most preferably 15% by mass or less. preferable.

General formula (i), general formula (i-1) to (i-11), general formula (i-1-1) to (i-1-19), general formula (i-2-1) to (i-2-7), general formula (i-3-1) to (i-3-10), general formula (i-4-1) to (i-4-6), general formula (i-5-1) to (i-5-4), general formula (i-6-1) to (i-6-4), general formula (i-7-1) to (i-7-4), general formula (i-8-1) to (i-8-2), general formula (i-9-1) to (i-9-4), general formula (i-10-1) to (i-10-2), general formula (i-11-1) to (i-11-2), structural formula (i-1-1.1) to (i-1-1.10), structural formula (i-1-2.1) to (i-1-2.5), structural formula (i-1-3.1) to (i-1-3.6), structural formula (i-1-4.1) to (i-1-4.6), structural formula (i-1-5.1) to (i-1-5.5), structural formula (i-1-6.1) to (i-1-6.6), structural formula (i-1-7.1) to (i-1-7.4), structural formula (i-1-8.1) to (i- 1-8.5), structural formula (i-1-9.1) to (i-1-9.4), structural formula (i-1-10.1) to (i-1-10.2), structural formula (i-1-11.1) to (i-1-11.6), structural formula (i-1-12.1) to (i-1-12.6), structural formula (i-1-13.1) to (i-1-13.4), structural formula (i-1-14.1) to (i-1-14.4), structural formula (i-1-15.1), structural formula (i-1-16.1), structural formula (i-1-17.1), structural formula (i-1-18. 1), structural formula (i-1-19.1), structural formula (i-2-1.1) to (i-2-1.6), structural formula (i-2-2.1) to (i-2-2.4), structural formula (i-2-3.1) to (i-2-3.4), structural formula (i-2-4.1) to (i-2-4.6), structural formula (i-2-5.1) to (i-2-5.5), structural formula (i-2-6.1) to (i-2-6.4), structural formula (i-2-7.1) to (i-2-7.4), structural formula (i-3-1.1) to (i-3-1.6), structural formula (i-3- 2.1) to (i-3-2.6), structural formula (i-3-3.1) to (i-3-3.6), structural formula (i-3-4.1) to (i-3-4.4), structural formula (i-3-5.1) to (i-3-5.4), structural formula (i-3-6.1) to (i-3-6.6), structural formula (i-3-7.1), structural formula (i-3-8.1), structural formula (i-3-9.1), structural formula (i-3-10.1), structural formula (i-4-1.1) to (i-4-1.4), structural formula (i-4-2.1) to (i-4-2.4), structural formula Formulae (i-4-3.1) to (i-4-3.4), structural formulae (i-4-4.1) to (i-4-4.4), structural formula (i-4-5.1), structural formula (i-4-6.1), structural formula (i-5-1.1) to (i-5-1.4), structural formula (i-5-2.1) to (i-5-2.4), structural formula (i-5-3.1) to (i-5-3.4), structural formula (i-5-4.1) to (i-5-4.4), structural formula (i-6-1.1) to (i-6-1.4), structural formula (i-6-2.1) to (i-6-2.4), structural formula Structural formula (i-6-3.1) to (i-6-3.4), structural formula (i-6-4.1) to (i-6-4.4), structural formula (i-7-1.1) to (i-7-1.4), structural formula (i-7-2.1) to (i-7-2.4), structural formula (i-7-3.1) to (i-7-3.4), structural formula (i-7-4.1) to (i-7-4.4), structural formula (i-8-1.1) to (i-8-1.2), structural formula (i-8-2.1) to (i-8-2.2), structural formula (i-9-1.1) to (i-9-1.4), structural formula The total content of the compounds represented by formulae (i-9-2.1) to (i-9-2.4), structural formulae (i-9-3.1) to (i-9-3.4), structural formulae (i-9-4.1) to (i-9-4.4), structural formulae (i-10-1.1) to (i-10-1.2), structural formulae (i-10-2.1) to (i-10-2.2), structural formulae (i-11-1.1) to (i-11-1.2), or structural formulae (i-11-2.1) to (i-11-2.2) in 100% by mass of the liquid crystal composition is preferably _0.1 to 95% by mass, more preferably 0.5 to 90% by mass, more preferably 1 to 85% by mass, more preferably 1 to 30% by mass, more preferably 1 to 20% by mass, and more preferably 5 to 15% by mass, from the viewpoints of solubility, Δn, and/or Δε r.

The compound represented by formula (i) (including its sub-concepts) can be synthesized by known synthesis methods, some of which are exemplified below.
The indene derivative (A-1), which is a synthetic intermediate for the compound according to the present invention, can be obtained, for example, by the production method shown below.

In the formula, R ⁱ¹ , L ⁱ¹ and L ⁱ² have the same meanings as R ⁱ¹ , L ⁱ¹ and L ⁱ² in the general formula (i) above.
The indene derivative (A-2), which is a synthetic intermediate for the compound according to the present invention, can be obtained, for example, by the production method shown below.

In the formula, R ⁱ¹ , L ⁱ¹ and L ⁱ² have the same meanings as R ⁱ¹ , L ⁱ¹ and L ⁱ² in the general formula (i) above.
In the present invention, the compound represented by the general formula (i) can be produced, for example, as follows.
(Production Method 1) Production of a compound represented by the following general formula (s-6):

In the formula, R ⁱ¹ , A ⁱ² , L ⁱ¹ , L ⁱ² , S ⁱ¹ and X ⁱ¹ have the same meanings as R ⁱ¹ , A ⁱ² , L ⁱ¹ , L ⁱ² , S ⁱ¹ and X ⁱ¹ in the general formula (i) above.
The compound represented by the general formula (s-1) is reacted with magnesium, and then treated with triisopropyl borate and then with hydrochloric acid to obtain a boric acid derivative, which is a compound represented by the general formula (s-2).
Next, the compound represented by the general formula (s-2) is reacted with the compound represented by the general formula (s-3) to obtain the compound represented by the general formula (s-4).
The reaction method includes, for example, Suzuki coupling reaction using a palladium catalyst and a base.
Specific examples of palladium catalysts include [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride, palladium(II) acetate, dichlorobis[di-tert-butyl(p-dimethylaminophenyl)phosphino]palladium(II), dichlorobis(triphenylphosphine)palladium(II), tetrakis(triphenylphosphine)palladium(0), and the like.
Examples of the base include potassium carbonate, sodium carbonate, potassium phosphate, and the like.
Next, the compound represented by general formula (s-4) is reacted with the compound represented by general formula (s-5) to obtain the target compound represented by general formula (s-6).
The reaction method includes, for example, Sonogashira coupling reaction using a palladium catalyst, a copper catalyst and a base.
Specific examples of palladium catalysts include [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride, palladium(II) acetate, dichlorobis[di-tert-butyl(p-dimethylaminophenyl)phosphino]palladium(II), dichlorobis(triphenylphosphine)palladium(II), tetrakis(triphenylphosphine)palladium(0), and the like.
When palladium(II) acetate is used as the metal catalyst, a ligand such as triphenylphosphine or 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl may be added.
A specific example of the copper catalyst is copper(I) iodide.
A specific example of the base is triethylamine.
(Production Method 2) Production of a compound represented by the following general formula (s-12):

In the formula, R ⁱ¹ , A ⁱ² , L ⁱ¹ , L ⁱ² , S ⁱ¹ and X ⁱ¹ have the same meanings as R ⁱ¹ , A ⁱ² , L ⁱ¹ , L ⁱ² , S ⁱ¹ and X ⁱ¹ in the general formula (i) above.
The compound represented by the general formula (s-7) can be reacted with trimethylsilylacetylene, and then reacted with potassium carbonate in an alcohol solvent to obtain the compound represented by the general formula (s-8).
Reactions with trimethylsilylacetylene include the Sonogashira coupling reaction using a palladium catalyst, a copper catalyst and a base.
Specific examples of the palladium catalyst and the base include those mentioned above.
Next, the compound represented by general formula (s-8) is reacted with the compound represented by general formula (s-9) to obtain the compound represented by general formula (s-10).
The reaction method includes, for example, Sonogashira coupling reaction using a palladium catalyst, a copper catalyst and a base.
Specific examples of the palladium catalyst and the base include those mentioned above.
The target compound represented by general formula (s-12) can be obtained by reacting the compound represented by general formula (s-10) with the compound represented by general formula (s-11).
The reaction method includes, for example, Suzuki coupling reaction using a palladium catalyst and a base.
(Production Method 3) Production of a compound represented by the following general formula (s-17):

In the formula, R ⁱ¹ , A ⁱ² , L ⁱ¹ , L ⁱ² , S ⁱ¹ and X ⁱ¹ have the same meanings as R ⁱ¹ , A ⁱ² , L ⁱ¹ , L ⁱ² , S ⁱ¹ and X ⁱ¹ in the general formula (i) above.
First, a compound represented by general formula (s-13) is reacted with a compound represented by general formula (s-14) to obtain a compound represented by general formula (s-15).
The reaction method includes, for example, Sonogashira coupling reaction using a palladium catalyst, a copper catalyst and a base.
Specific examples of the palladium catalyst and the base include those mentioned above.
Furthermore, the target compound represented by general formula (s-17) can be obtained by reacting the compound represented by general formula (s-15) with the compound represented by general formula (s-16).
The reaction method includes, for example, Sonogashira coupling reaction using a palladium catalyst, a copper catalyst and a base.
Specific examples of the palladium catalyst and the base include those mentioned above.
(Production Method 4) Production of a compound represented by the following general formula (s-21):

In the formula, R ⁱ¹ , L ⁱ¹ , L ⁱ² and X ⁱ¹ have the same meanings as R ⁱ¹ , L ⁱ¹ , L ⁱ² and X ⁱ¹ in the general formula (i) above.
First, a compound represented by general formula (s-18) is reacted with magnesium, and then treated with triisopropyl borate and then with hydrochloric acid to obtain a boric acid derivative, which is a compound represented by general formula (s-19).
Next, the compound represented by general formula (s-19) is reacted with the compound represented by general formula (s-20) to obtain the target compound represented by general formula (s-21).
The reaction method includes, for example, Suzuki coupling reaction using a palladium catalyst and a base.
Specific examples of the palladium catalyst and the base include those mentioned above.
(Production Method 5) Production of a compound represented by the following general formula (s-24):

In the formula, R ⁱ¹ , L ⁱ¹ , L ⁱ² , S ⁱ¹ and X ⁱ¹ have the same meanings as R ⁱ¹ , L ⁱ¹ , L ⁱ² , S ⁱ¹ and X ⁱ¹ in the general formula (i) above.
The target compound represented by general formula (s-24) can be obtained by reacting a compound represented by general formula (s-22) with a compound represented by general formula (s-23).
The reaction method includes, for example, Sonogashira coupling reaction using a palladium catalyst, a copper catalyst and a base.
Specific examples of the palladium catalyst and the base include those mentioned above.
(Production Method 6) Production of a compound represented by the following formula (s-30):

In the formula, R ⁱ¹ , A ⁱ² , L ⁱ¹ , L ⁱ² and S ⁱ¹ have the same meanings as R ⁱ¹ , A ⁱ² , L ⁱ¹ , L ⁱ² and S ⁱ¹ in the general formula (i) above.
First, a compound represented by general formula (s-27) can be obtained by reacting a compound represented by general formula (s-25) with a compound represented by general formula (s-26).
The reaction method includes, for example, Suzuki coupling reaction using a palladium catalyst and a base.
Specific examples of the palladium catalyst and the base include those mentioned above.
Next, the compound represented by general formula (s-27) is reacted with the compound represented by general formula (s-28) to obtain the compound represented by general formula (s-29).
An example of the reaction method is the Wittig reaction.
Furthermore, the nitro group of the compound represented by general formula (s-29) is converted to an amino group using iron or the like, and the amino group is reacted with a thiocarbamate compound to obtain the target compound represented by general formula (s-30).
(Production Method 7) Production of a compound represented by the following general formula (s-34):

In the formula, R ⁱ¹ , A ⁱ¹ , A ⁱ² , L ⁱ¹ and L ⁱ² have the same meanings as R ⁱ¹ , A ⁱ¹ , A ⁱ² , L ⁱ¹ and L ⁱ² in the general formula (i) above.
First, a compound represented by general formula (s-31) is reacted with a compound represented by general formula (s-32) to obtain a compound represented by general formula (s-33).
The reaction method includes, for example, Sonogashira coupling reaction using a palladium catalyst, a copper catalyst and a base.
Specific examples of the palladium catalyst, copper catalyst and base include those mentioned above.
Next, the nitro group of the compound represented by general formula (s-33) is converted to an amino group using iron or the like, and the resulting compound is reacted with thiophosgene to obtain the target compound represented by general formula (s-34).
Reaction conditions other than those described in each step may be those described in, for example, Jikken Kagaku Koza (edited by the Chemical Society of Japan, published by Maruzen Co., Ltd.), Organic Syntheses (A John Wiley & Sons, Inc., Publication), Beilstein Handbook of Organic Chemistry (Beilstein-Institut fur Literatur der Organischen Chemie, Springer-Verlag Berlin and Heidelberg GmbH & Co. K), Fiesers' Reagents for Organic Synthesis (John Wiley & Sons, Sons, Inc.) or those included in databases such as SciFinder (Chemical Abstracts Service, American Chemical Society) and Reaxis (Elsevier Ltd.).
When a substance that is unstable to oxygen and/or moisture is handled in each step, it is preferable to carry out the work in an inert gas such as nitrogen gas or argon gas.
In each step, functional groups can be protected as necessary.
Examples of the protecting group include those described in GREENE'S PROTECTIVE GROUPS IN ORGANIC SYNTHESIS ((Fourth Edition), co-authored by PETER GM WUTS and THEODORA W. GREENE, A John Wiley & Sons, Inc., Publication).
In addition, purification may be carried out in each step as necessary.
Purification methods include chromatography, recrystallization, distillation, sublimation, reprecipitation, adsorption, and liquid separation.
Specific examples of the purification agent include silica gel, alumina, and activated carbon.

<Characteristic values of the compound represented by general formula (i) (including sub-concepts)>
The characteristic values of the compound represented by general formula (i) (including sub-concepts) can be measured as follows.
First, a compound represented by general formula (i) (including subordinate concepts) is added to a mother liquid crystal to prepare liquid crystal compositions containing 0 mass %, 5 mass %, and 10 mass % of the compound represented by general formula (i) (including subordinate concepts) per 100 mass % of the liquid crystal composition, and Δn (refractive index anisotropy) and _Δεr of each liquid crystal composition are measured.
Then, using the least squares method, Δn (refractive index anisotropy) and Δε r of 100% by mass of the compound represented by general formula (i) (including subordinate concepts), that is, the compound represented by general formula (i) (including subordinate concepts), are determined from extrapolated _values .

Δn (refractive index anisotropy) correlates with Δn in the near-infrared region used in the optical sensor described below.
The larger Δn is, the greater the phase modulation power of light of the target wavelength is, and therefore, this is particularly suitable for optical sensors.
Δn at 25° C. and 589 nm is determined from the difference ( _{ne −no )} between the extraordinary refractive index ( _ne ) and the ordinary refractive index (no) of the liquid crystal composition using an Abbe refractometer.
Also, Δn can be obtained from a phase difference measuring device.
The relationship between the retardation Re, the thickness d of the liquid crystal layer, and Δn is Δn=Re/d.
A liquid crystal composition is injected into a glass cell having a cell gap (d) of about 3.0 μm and a polyimide alignment film that has been subjected to anti-parallel rubbing treatment, and the in-plane Re is measured using a retardation film/optical material inspection device RETS-100 (manufactured by Otsuka Electronics Co., Ltd.).
The measurement was carried out at a temperature of 25° C. and at 589 nm, and the measurement was unitless.
The Δn at 25° C. and 589 nm of the compound (including subordinate concepts) represented by general formula (i) according to the present invention is preferably 0.30 or more, more preferably 0.35 to 0.60, more preferably 0.37 to 0.55, and even more preferably 0.40 to 0.55, from the viewpoint of the phase modulation power of light of the wavelength.

The higher the dielectric anisotropy in the high frequency region, the greater the phase modulation power for radio waves in the target frequency band, and therefore the material is particularly suitable for use in antennas.
In addition, in antenna applications, the smaller the dielectric tangent in the high frequency range, the smaller the energy loss in the target frequency band, which is preferable.
In the compound (including sub-concepts) represented by the general formula (i) according to the present invention, the dielectric anisotropy Δε _r at 10 GHz was measured as a representative characteristic in the high frequency range.
_Δεr =( _εr∥ − _εr⊥ ).
Here, "ε _r " is a dielectric constant, the subscript "∥" indicates a component parallel to the alignment direction of the liquid crystal, and "⊥" indicates a component perpendicular to the alignment direction of the liquid crystal.

_Δεr can be measured by the following method.
First, a liquid crystal composition is introduced into a capillary tube made of polytetrafluoroethylene (PTFE).
The capillary used here has an inner radius of 0.80 mm and an outer radius of 0.835 mm, with an effective length of 4.0 cm.
The capillary tube containing the liquid crystal composition is introduced into the center of a cavity resonator (manufactured by EM Lab Co., Ltd.) having a resonance frequency of 10 GHz.
The cavity has an outer diameter of 30 mm and a width of 26 mm.
A signal is then input, and the result of the output signal is recorded using a network analyzer (manufactured by Keysight Technologies, Inc.).
The dielectric constant (ε _r ) at 10 GHz is determined using the difference between the resonance frequency of a PTFE capillary tube containing no liquid crystal composition and the resonance frequency of a PTFE capillary tube containing a liquid crystal composition.
The resonance frequency and the like using a PTFE capillary tube filled with a liquid crystal composition are determined as values of characteristic components perpendicular and parallel to the alignment direction of the liquid crystal molecules by controlling the alignment of the liquid crystal molecules.
The magnetic field of a permanent magnet or electromagnet is used to align the liquid crystal molecules in the vertical direction (perpendicular to the effective length direction) or in the parallel direction (parallel to the effective length direction) of the PTFE capillary tube.
The magnetic field has, for example, a pole-to-pole distance of 45 mm and a magnetic field strength of 0.23 Tesla near the center.
The PTFE capillary tube containing the liquid crystal composition is rotated parallel or perpendicular to the magnetic field to obtain the desired characteristic components.
The measurements were made at a temperature of 25° C., and Δε _r has no unit.

The Δε _r at 25° C. of the compound (including subordinate concepts) represented by general formula (i) according to the present invention is preferably larger, and from the viewpoint of phase modulation power in the GHz band, it is preferably 0.33 or more, preferably 0.33 to 0.65, preferably 0.34 to 0.60, preferably 0.34 to 0.55, preferably 0.35 to 0.50, preferably 0.35 to 0.45, and preferably 0.35 to 0.40.

(Liquid Crystal Composition)
The liquid crystal composition according to the present invention can be produced, for example, by mixing the compound represented by the above general formula (i) (including sub-concepts) and, if necessary, other liquid crystal compounds and additives.

Additives include stabilizers, dye compounds, polymerizable compounds, azotolane compounds, etc.

Examples of the stabilizer include hydroquinones, hydroquinone monoalkyl ethers, tert-butylcatechols, pyrogallols, thiophenols, nitro compounds, β-naphthylamines, β-naphthols, nitroso compounds, hindered phenols, and hindered amines.
Examples of the hindered phenols include hindered phenol-based antioxidants represented by the following structural formulas (XX-1) to (XX-3).

Examples of hindered amines include hindered amine light stabilizers represented by the following structural formulas (YY-1) to (YY-2).

When a stabilizer is used, the type of stabilizer used in the liquid crystal composition is one or more, preferably 1 to 10 types, preferably 1 to 8 types, preferably 1 to 6 types, preferably 1 to 4 types, preferably 1 to 2 types.
When a stabilizer is used, the total content of the stabilizer in 100% by mass of the liquid crystal composition is preferably 0.005 to 1% by mass, more preferably 0.02 to 0.50% by mass, and even more preferably 0.03 to 0.35% by mass.

As other liquid crystal compounds, it is preferable that the liquid crystal composition contains one or more compounds represented by the following general formula (ii) from the viewpoints of solubility, Δn and/or Δεr.

In formula (ii), R ⁱⁱ¹ represents an alkyl group having 1 to 20 carbon atoms.
The alkyl group may be a straight-chain, branched or cyclic alkyl group, and is preferably a straight-chain alkyl group.
The alkyl group preferably has 2 to 10, preferably 2 to 6 carbon atoms.
One or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -NH-, -CO- and/or -CS-.
In addition, one or more -CH ₂ -CH ₂ - in the alkyl group may be substituted with -CH=CH-, -CF=CF- and/or -C≡C-.
Furthermore, one or more hydrogen atoms in the alkyl group may each independently be substituted with a halogen atom.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
However, when the alkyl group is substituted with a specific group, the oxygen atoms are not directly bonded to each other.
From the viewpoint of the stability of the compound, it is preferable that sulfur atoms and/or oxygen atoms are not directly bonded to each other.
For example, R ⁱⁱ¹ can represent an alkoxy group having 1 to 19 carbon atoms by replacing one --CH ₂ -- in the alkyl group with --O--.
The alkoxy group is a linear, branched or cyclic alkoxy group, and is preferably a linear alkoxy group.
The alkoxy group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, R ⁱⁱ¹ can represent an alkylsulfanyl group (alkylthio group) having 1 to 19 carbon atoms by replacing one —CH ₂ — in the alkyl group with —S—.
The alkylsulfanyl group is a linear, branched or cyclic alkylsulfanyl group, and is preferably a linear alkylsulfanyl group.
The alkylsulfanyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms.
Furthermore, R ⁱⁱ¹ can represent an alkenyl group having 2 to 20 carbon atoms by replacing one or more -CH ₂ -CH ₂ - in the alkyl group with -CH=CH-.
The alkenyl group is a linear, branched or cyclic alkenyl group, and is preferably a linear alkenyl group.
The alkenyl group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, R ⁱⁱ¹ can represent an alkynyl group having 2 to 20 carbon atoms by replacing one or more -CH ₂ -CH ₂ - in the alkyl group with -C≡C-.
The alkynyl group may be a linear, branched or cyclic alkynyl group, and is preferably a linear alkynyl group.
The alkynyl group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
As the alkynyl group, from the viewpoints of ease of synthesis and elongation of the conjugated system, an alkynyl group represented by the following formula (R ⁱⁱ¹ -A) is preferred.

In formula (R ⁱⁱ¹ -A), R ^ii1A represents an alkyl group having 1 to 18 carbon atoms.
The alkyl group having 1 to 18 carbon atoms may be a straight-chain, branched or cyclic alkyl group, and is preferably a straight-chain alkyl group.
The alkyl group having 1 to 18 carbon atoms preferably has 1 to 8 carbon atoms.
One or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -NH-, -CO- and/or -CS-.
Furthermore, one or more -CH ₂ -CH ₂ - groups in the alkyl group may each independently be substituted by -CH=CH-, -CF=CF- and/or -C≡C-.
Furthermore, one or more hydrogen atoms in the alkyl group may each independently be substituted with a halogen atom.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
However, when the alkyl group is substituted with a specific group, the oxygen atoms are not directly bonded to each other.
From the viewpoint of the stability of the compound, it is preferable that sulfur atoms and/or oxygen atoms are not directly bonded to each other.
In addition, in formula (R ⁱⁱ¹ -A), the black dot represents a bond to A ⁱⁱ¹ .
Furthermore, R ⁱⁱ¹ can represent an alkenyloxy group having 2 to 19 carbon atoms in which one —CH ₂ — in the alkyl group is replaced with —O— and one or more —CH ₂ —CH ₂ — are replaced with —CH═CH—.
The alkenyloxy group is a linear, branched or cyclic alkenyloxy group, and is preferably a linear alkenyloxy group.
The alkenyloxy group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, R ⁱⁱ¹ can represent a halogenated alkyl group having 1 to 20 carbon atoms, in which one or more hydrogen atoms in the alkyl group have been substituted with halogen atoms.
The halogenated alkyl group may be linear, branched or cyclic, and is preferably a linear halogenated alkyl group.
The halogenated alkyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
In addition, R ⁱⁱ¹ can represent a halogenated alkoxy group having 1 to 19 carbon atoms, in which one —CH ₂ — in the alkyl group is replaced with —O—, and one or more hydrogen atoms in the alkyl group are replaced with halogen atoms.
The halogenated alkoxy group may be a linear, branched or cyclic halogenated alkoxy group, and is preferably a linear halogenated alkoxy group.
The halogenated alkoxy group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
Specific examples of the alkyl group having 1 to 20 carbon atoms for R ⁱⁱ¹ (including substituted ones) include groups represented by formulae (R ⁱⁱ¹ -1) to (R ⁱⁱ¹ -56).

In formulae (R ⁱⁱ¹ -1) to (R ⁱⁱ¹ -56), the black dot represents a bond to A ⁱⁱ¹ .
When the ring structure to which R ⁱⁱ¹ is bonded is a phenyl group (aromatic), a linear alkyl group having 1 to 5 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms, and an alkenyl group having 4 to 5 carbon atoms are preferred; when the ring structure to which R ⁱⁱ¹ is bonded is a saturated ring structure such as cyclohexane, pyran, and dioxane, a linear alkyl group having 1 to 5 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms, and a linear alkenyl group having 2 to 5 carbon atoms are preferred.
In order to stabilize the nematic phase, R ⁱⁱ¹ preferably has a total of 5 or less carbon atoms and, if present, oxygen atoms, and is preferably linear.
From the viewpoint of solubility, R ⁱⁱ¹ is preferably a linear or branched alkyl group having 2 to 8 carbon atoms, a linear alkoxy group having 2 to 8 carbon atoms, a linear halogenated alkoxy group having 1 to 8 carbon atoms, a linear alkynyl group having 2 to 8 carbon atoms, or a linear alkylsulfanyl group having 1 to 6 carbon atoms.

In the general formula (ii), A ⁱⁱ¹ and A ⁱⁱ² each independently represent the following group (a), group (b), group (c), and group (d):
(a) a 1,4-cyclohexylene group (in which one —CH ₂ — or two or more non-adjacent —CH ₂ — groups may be replaced by —O— and/or —S—).
(b) a 1,4-phenylene group (in which one -CH= or two or more -CH= groups may be replaced by -N=).
(c) 1,4-cyclohexenylene group, bicyclo[2.2.2]octane-1,4-diyl group, naphthalene-2,6-diyl group, naphthalene-1,4-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, 5,6,7,8-tetrahydronaphthalene-1,4-diyl group, decahydronaphthalene-2,6-diyl group, anthracene-2,6-diyl group, anthracene-1,4-diyl group, anthracene-9,10-diyl group, phenanthrene-2,7-diyl group, 2,3-dihydroindene-2,5-diyl group, 2 ,3-dihydroindene-1,5-diyl group, 2,3-dihydroindene-3,5-diyl group (one -CH= or two or more -CH= present in a naphthalene-2,6-diyl group, a naphthalene-1,4-diyl group, a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, a 5,6,7,8-tetrahydronaphthalene-1,4-diyl group, an anthracene-2,6-diyl group, an anthracene-1,4-diyl group, an anthracene-9,10-diyl group, or a phenanthrene-2,7-diyl group may be replaced by -N=).
(d) thiophene-2,5-diyl group, benzothiophene-2,5-diyl group, benzothiophene-2,6-diyl group, dibenzothiophene-3,7-diyl group, dibenzothiophene-2,6-diyl group, thieno[3,2-b]thiophene-2,5-diyl group, benzo[1,2-b:4,5-b']dithiophene-2,6-diyl group (one -CH= or two or more -CH= present in this group may be replaced by -N=).
represents a group selected from the group consisting of:

One or more hydrogen atoms in A ⁱⁱ¹ and A ⁱⁱ² may each independently be substituted with a substituent S ⁱⁱ¹ .
The substituent S ⁱⁱ¹ represents any one of a halogen atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a trimethylsilyl group, a dimethylsilyl group, a thioisocyano group, and an alkyl group having 1 to 20 carbon atoms.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The alkyl group having 1 to 20 carbon atoms may be a straight-chain, branched or cyclic alkyl group, and is preferably a straight-chain alkyl group.
The alkyl group having 1 to 20 carbon atoms preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
One or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -NH-, -CO- and/or -CS-.
Furthermore, one or more -CH ₂ -CH ₂ - groups in the alkyl group may each independently be substituted by -CH=CH-, -CF=CF- and/or -C≡C-.
Furthermore, one or more hydrogen atoms in the alkyl group may each independently be substituted with a halogen atom.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
However, when the alkyl group is substituted with a specific group, the oxygen atoms are not directly bonded to each other.
From the viewpoint of the stability of the compound, it is preferable that sulfur atoms and/or oxygen atoms are not directly bonded to each other.
For example, the substituent S ⁱⁱ¹ can represent an alkoxy group having 1 to 19 carbon atoms by replacing one --CH ₂ -- in the alkyl group with --O--.
The alkoxy group is a linear, branched or cyclic alkoxy group, and is preferably a linear alkoxy group.
The alkoxy group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, the substituent S ⁱⁱ¹ can represent an alkylsulfanyl group (alkylthio group) having 1 to 19 carbon atoms by replacing one --CH ₂ -- in the alkyl group with --S--.
The alkylsulfanyl group is a linear, branched or cyclic alkylsulfanyl group, and is preferably a linear alkylsulfanyl group.
The alkylsulfanyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
Furthermore, the substituent S ⁱⁱ¹ can represent an alkenyl group having 2 to 20 carbon atoms by replacing one or more -CH ₂ -CH ₂ - in the alkyl group with -CH=CH-.
The alkenyl group is a linear, branched or cyclic alkenyl group, and is preferably a linear alkenyl group.
The alkenyl group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, the substituent S ⁱⁱ¹ can represent an alkynyl group having 2 to 20 carbon atoms by replacing one or more -CH ₂ -CH ₂ - in the alkyl group with -C≡C-.
The alkynyl group may be a linear, branched or cyclic alkynyl group, and is preferably a linear alkynyl group.
The alkynyl group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
In addition, the substituent S ⁱⁱ¹ can represent an alkenyloxy group having 2 to 19 carbon atoms by replacing one —CH ₂ — in the alkyl group with —O— and one or more —CH ₂ —CH ₂ — groups with —CH═CH—.
The alkenyloxy group is a linear, branched or cyclic alkenyloxy group, and is preferably a linear alkenyloxy group.
The alkenyloxy group preferably has 2 to 10, more preferably 2 to 6, carbon atoms.
Furthermore, the substituent S ⁱⁱ¹ can represent a halogenated alkyl group having 1 to 20 carbon atoms by substituting one or more hydrogen atoms in the alkyl group with halogen atoms.
The halogenated alkyl group may be linear, branched or cyclic, and is preferably a linear halogenated alkyl group.
The halogenated alkyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
In addition, the substituent S ⁱⁱ¹ can represent a halogenated alkoxy group having 1 to 19 carbon atoms, in which one -CH ₂ - in the alkyl group is replaced with -O-, and one or more hydrogen atoms in the alkyl group are replaced with halogen atoms.
The halogenated alkoxy group may be a linear, branched or cyclic halogenated alkoxy group, and is preferably a linear halogenated alkoxy group.
The halogenated alkoxy group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms.
Specific examples of the alkyl group having 1 to 20 carbon atoms (including substituted ones) in the substituent S ⁱⁱ¹ include groups represented by the formulae (S ^ii1R -1) to (S ^ii1R -36).

In formulae (S ^ii1R -1) to (S ^ii1R -36), the black dot represents a bond to A ⁱⁱ¹ or A ⁱⁱ² .
The substituent S ⁱⁱ¹ is preferably a linear alkyl group having 1 to 6 carbon atoms, a fluorine atom or a chlorine atom.
Furthermore, at least one of A ⁱⁱ¹ or A ⁱⁱ² is preferably substituted with at least one substituent S ⁱⁱ¹ , preferably with a halogen atom, and more preferably with a fluorine atom.
When there are a plurality of substituents S ⁱⁱ¹ , they may be the same or different.

The substitution position of the substituent S ⁱⁱ¹ in A ⁱⁱ¹ is preferably any one of the following formulae (A ⁱⁱ¹ -SP-1) to (A ⁱⁱ¹ -SP-12).

In formulae (A ⁱⁱ¹ -SP-1) to (A ⁱⁱ¹ -SP-12), a white dot represents a bond to R ⁱⁱ¹ or Z ⁱⁱ¹ , and a black dot represents a bond to Z ⁱⁱ¹ .
The substitution position of the substituent S ⁱⁱ¹ in A ⁱⁱ² is preferably any one of the following formulae (A ⁱⁱ² -SP-1) to (A ⁱⁱ² -SP-8).

In the formulae (A ⁱⁱ² -SP-1) to (A ⁱⁱ² -SP-8), the white dots represent bonds to Z ⁱⁱ¹ , and the black dots represent bonds to an isothiocyanate group (-NCS).
More specifically, A ⁱⁱ¹ preferably represents any one of the following formulae (A ⁱⁱ¹ -1) to (A ⁱⁱ¹ -34).

In formulae (A ⁱⁱ¹ -1) to (A ⁱⁱ¹ -34), a white dot represents a bond to R ⁱⁱ¹ or Z ⁱⁱ¹ , and a black dot represents a bond to Z ⁱⁱ¹ .
More specifically, A ⁱⁱ² preferably represents any one of the following formulas (A ⁱⁱ² -1) to (A ⁱⁱ² -10).

In formulae (A ⁱⁱ² -1) to (A ⁱⁱ² -10), white dots represent bonds to Z ⁱⁱ¹ , and black dots represent bonds to an isothiocyanate group (--NCS).

In formula (ii), Z ⁱⁱ¹ represents a single bond or an alkylene group having 1 to 20 carbon atoms.
One or more -CH ₂ - in the alkylene group may each independently be substituted with -O-, -CF ₂ - and/or -CO-.
Furthermore, one or more -CH ₂ -CH ₂ - in the alkylene group may each independently be substituted with -CH ₂ -CH(CH ₃ )-, -CH(CH ₃ )-CH ₂ -, -CH=CH-, -CF=CF-, -CH=C(CH ₃ )-, -C(CH ₃ )=CH-, -CH=N-, -N=CH-, -N=N-, -C≡C-, -CO-O- and/or -O-CO-.
However, when the alkylene group having 1 to 20 carbon atoms is substituted with a specific group, the oxygen atoms are not directly bonded to each other.
From the viewpoint of the stability of the compound, it is preferable that sulfur atoms and/or oxygen atoms are not directly bonded to each other.
Specific examples of the alkylene group having 1 to 20 carbon atoms (including substituted ones) include groups represented by the formulae (Z ⁱⁱ¹ -1) to (Z ⁱⁱ¹ -24).

In formulae (Z ⁱⁱ¹ -1) to (Z ⁱⁱ¹ -24), a white dot represents a bond to A ⁱⁱ¹ , and a black dot represents a bond to A ⁱⁱ¹ or A ⁱⁱ² .

In formula (ii), n ⁱⁱ¹ represents an integer of 1 to 4, preferably 1 or 2.
When n ⁱⁱ¹ is 1, Z ⁱⁱ¹ preferably represents a single bond or -C≡C- from the viewpoint of Δn and/or _Δεr .
When n ⁱⁱ¹ is 2, Z ⁱⁱ¹ preferably represents a single bond or -C≡C- from the viewpoint of Δn and/or _Δεr .
In addition, in general formula (ii), when a plurality of A ⁱⁱ¹ and Z ⁱⁱ¹ are present, they may be the same or different.

As the compound represented by general formula (ii), it is preferable to use compounds represented by the following general formulas (ii-1) to (ii-4).

In the general formulae (ii-1) to (ii-4), R ⁱⁱ¹ , A ⁱⁱ¹ and A ⁱⁱ² have the same meanings as R ⁱⁱ¹ , A ⁱⁱ¹ and A ⁱⁱ² in the above general formula (ii), respectively.
In formulae (ii-3) and (ii-4), the definitions of A ^ii1-2 are each independently the same as the definition of A ⁱⁱ¹ in formula (ii) above.

As the compound represented by general formula (ii-1), a compound represented by the following general formula (ii-1-1) is preferable.

In formula (ii-1-1), R ⁱⁱ¹ and S ⁱⁱ¹ each independently have the same meaning as R ⁱⁱ¹ and S ⁱⁱ¹ in formula (ii) above.
Specific examples of the compound represented by general formula (ii-1-1) include compounds represented by the following structural formulas (ii-1-1.1) to (ii-1-1.8).

As the compound represented by general formula (ii-2), it is preferable to use compounds represented by the following general formulas (ii-2-1) to (ii-2-4).

In the general formulae (ii-2-1) to (ii-2-4), R ⁱⁱ¹ and S ⁱⁱ¹ each independently represent the same meaning as R ⁱⁱ¹ and S ⁱⁱ¹ in the above general formula (ii), respectively.

Specific examples of the compound represented by general formula (ii-2-1) include compounds represented by the following structural formulas (ii-2-1.1) to (ii-2-1.2).

Specific examples of the compound represented by general formula (ii-2-2) include the compounds represented by the following structural formulas (ii-2-2.1) to (ii-2-2.3).

Specific examples of the compound represented by general formula (ii-2-3) include the compounds represented by the following structural formulas (ii-2-3.1) to (ii-2-3.3).

Specific examples of the compound represented by general formula (ii-2-4) include compounds represented by the following structural formulas (ii-2-4.1) to (ii-2-4.3).

As the compound represented by general formula (ii-3), a compound represented by the following general formula (ii-3-1) is preferable.

In formula (ii-3-1), R ⁱⁱ¹ and S ⁱⁱ¹ each independently have the same meaning as R ⁱⁱ¹ and S ⁱⁱ¹ in formula (ii) above.
Specific examples of the compound represented by general formula (ii-3-1) include compounds represented by the following structural formulas (ii-3-1.1) to (ii-3-1.4).

As the compound represented by general formula (ii-4), a compound represented by the following general formula (ii-4-1) is preferable.

In formula (ii-4-1), R ⁱⁱ¹ and S ⁱⁱ¹ each independently have the same meaning as R ⁱⁱ¹ and S ⁱⁱ¹ in formula (ii) above.

The type of compound represented by general formula (ii) used in the liquid crystal composition is one or more types, preferably 1 to 15 types, preferably 1 to 10 types, preferably 1 to 5 types.

The total content of the compounds represented by general formula (ii) in 100% by mass of the liquid crystal composition is preferably 75 to 95% by mass, more preferably 80 to 95% by mass, and even more preferably 85 to 95% by mass or more.

The types of compounds represented by general formula (ii-1), general formula (ii-1-1) or structural formulas (ii-1-1.1) to (ii-1-1.8) used in the liquid crystal composition are one or more types, preferably 1 to 10 types, preferably 1 to 5 types, and preferably 1 to 3 types.

The total content of the compounds represented by general formula (ii-1), general formula (ii-1-1) or structural formulas (ii-1-1.1) to (ii-1-1.8) in 100% by mass of the liquid crystal composition is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, and even more preferably 10 to 40% by mass.

The types of compounds represented by general formula (ii-2), general formulas (ii-2-1) to (ii-2-4), structural formulas (ii-2-1.1) to (ii-2-1.2), structural formulas (ii-2-2.1) to (ii-2-2.3), structural formulas (ii-2-3.1) to (ii-2-3.3) or structural formulas (ii-2-4.1) to (ii-2-4.3) used in the liquid crystal composition are one or more types, preferably 1 to 15 types, preferably 1 to 10 types, and preferably 1 to 7 types.

The total content of the compounds represented by general formula (ii-2), general formulas (ii-2-1) to (ii-2-4), structural formulas (ii-2-1.1) to (ii-2-1.2), structural formulas (ii-2-2.1) to (ii-2-2.3), structural formulas (ii-2-3.1) to (ii-2-3.3) or structural formulas (ii-2-4.1) to (ii-2-4.3) in 100% by mass of the liquid crystal composition is preferably 1 to 80% by mass, more preferably 3 to 75% by mass, more preferably 5 to 70% by mass, more preferably 5 to 25% by mass, and more preferably 5 to 15% by mass.

The compounds represented by general formula (ii-3), general formula (ii-3-1) or structural formulas (ii-3-1.1) to (ii-3-1.4) used in the liquid crystal composition are one or more types, preferably 1 to 10 types, preferably 1 to 5 types, and preferably 1 to 3 types.

The total content of the compounds represented by general formula (ii-3), general formula (ii-3-1) or structural formulas (ii-3-1.1) to (ii-3-1.4) in 100% by mass of the liquid crystal composition is preferably 1 to 80% by mass, more preferably 1 to 20% by mass, more preferably 1 to 15% by mass, and even more preferably 1 to 10% by mass.

The compounds represented by general formula (ii-4), general formula (ii-4-1) or structural formulas (ii-4-1.1) to (ii-3-1.4) used in the liquid crystal composition are one or more types, preferably 1 to 10 types, preferably 1 to 5 types, and preferably 1 to 3 types.

The total content of the compounds represented by general formula (ii-4), general formula (ii-4-1) or structural formulas (ii-3-1.1) to (ii-3-1.4) in 100% by mass of the liquid crystal composition is preferably 1 to 25% by mass, more preferably 1 to 20% by mass, and even more preferably 5 to 15% by mass.

The compound represented by general formula (ii) (including its sub-concepts) can be synthesized using known synthesis methods.

<Characteristic values of liquid crystal composition>
The liquid crystal phase upper limit temperature (T _ni ) is the temperature at which the liquid crystal composition undergoes phase transition from a nematic phase to an isotropic phase.
T _ni is measured by preparing a preparation in which the liquid crystal composition is sandwiched between a slide glass and a cover glass, and observing the preparation under a polarizing microscope while heating the preparation on a hot stage.
It can also be measured by differential scanning calorimetry (DSC).
The unit used is "℃".
The higher the _Tni , the more the nematic phase can be maintained even at high temperatures, and the wider the operating temperature range can be, but since the liquid crystal is heated and melted during production, if the temperature is too high, it is not preferable because the liquid crystal is thermally deteriorated and high-temperature melting equipment is required. Also, the higher the _Tni , the poorer the storage stability at low temperatures tends to be, so it is difficult to achieve both high _Tni and storage stability.
.
The upper limit temperature (T _ni ) of the liquid crystal phase of the liquid crystal composition according to the present invention can be appropriately set depending on whether the liquid crystal display element is used indoors, in a car, or outdoors, where the external temperature can be controlled, and from the viewpoint of the driving temperature range, it is preferably 100° C. or higher, more preferably 110 to 170° C., and even more preferably 115 to 165° C.

The liquid crystal phase lower limit temperature (T _→n ) is the temperature at which the liquid crystal composition undergoes phase transition from another phase (glass phase, smectic phase, crystalline phase) to the nematic phase.
T _→n is measured by filling a glass capillary with the liquid crystal composition, immersing it in a refrigerant at −70° C. to cause the liquid crystal composition to undergo phase transition to another phase, and observing while increasing the temperature.
It can also be measured by differential scanning calorimetry (DSC).
The unit used is "℃".
The lower T _→n is, the more the nematic phase can be maintained even at low temperatures, and therefore the wider the operating temperature range can be.
The liquid crystal phase lower limit temperature (T _→n ) of the liquid crystal composition according to the present invention is preferably 10°C or lower, more preferably -70 to 0°C, and even more preferably -40 to -5°C, from the viewpoint of driving temperature.

Δn (refractive index anisotropy) correlates with Δn in the near-infrared region used in the optical sensor described below.
The larger Δn is, the greater the phase modulation power of light of the target wavelength is, and therefore, it is particularly suitable for optical sensors.
Δn at 25° C. and 589 nm is determined from the difference ( _{ne −no )} between the extraordinary refractive index ( _ne ) and the ordinary refractive index (no) of the liquid crystal composition using an Abbe refractometer.
Also, Δn can be obtained from a phase difference measuring device.
The relationship between the retardation Re, the thickness d of the liquid crystal layer, and Δn is Δn=Re/d.
A liquid crystal composition is injected into a glass cell having a cell gap (d) of about 3.0 μm and a polyimide alignment film that has been subjected to anti-parallel rubbing treatment, and the in-plane Re is measured using a retardation film/optical material inspection device RETS-100 (manufactured by Otsuka Electronics Co., Ltd.).
The measurement was performed at 25° C. and 589 nm, and has no unit. In order to increase Δn, there is a method of using a compound with extended π-conjugation, but since the rotational viscosity (γ ₁ ) also increases at the same time, it is difficult to use it frequently from the viewpoint of response speed.
The Δn at 25° C. and 589 nm of the liquid crystal composition according to the present invention is preferably 0.40 or more, more preferably 0.40 to 0.55, more preferably 0.41 to 0.50, and even more preferably 0.43 to 0.48, from the viewpoint of the phase modulation power of light of the wavelength.

The rotational viscosity (γ ₁ ) is the viscosity coefficient related to the rotation of the liquid crystal molecules.
γ ₁ can be measured by filling the liquid crystal composition into a glass cell having a cell gap of about 10 μm, applying a voltage of 50 V, and using LCM-2 (manufactured by Toyo Corporation).
In the case of a liquid crystal composition having a positive dielectric anisotropy, a horizontally aligned cell is used, whereas in the case of a liquid crystal composition having a negative dielectric anisotropy, a vertically aligned cell is used.
The measurement is carried out at a temperature of 25° C., and the unit is mPa·s.
The smaller _γ1 is, the faster the response speed of the liquid crystal composition becomes, and therefore, it is suitable for any liquid crystal display element.
The rotational viscosity (γ ₁ ) of the liquid crystal composition according to the present invention at 25° C. is preferably from 150 to 1200 mPa·s, more preferably from 200 to 900 mPa·s, and even more preferably from 250 to 700 mPa·s, from the viewpoint of response speed.

The higher the dielectric anisotropy in the high frequency region, the greater the phase modulation power for radio waves in the target frequency band, and therefore the material is particularly suitable for use in antennas.
In addition, in antenna applications, the smaller the dielectric tangent in the high frequency range, the smaller the energy loss in the target frequency band, which is preferable.
In the liquid crystal composition according to the present invention, the dielectric anisotropy Δε _r and the average value tan δ _iso of the dielectric tangent at 10 GHz were measured as representative characteristics in the high frequency range.
Δε _r = (ε _r∥ - ε _r⊥ ) and tan δ _iso = (2ε _r⊥ tan δ _⊥ + ε _r∥ tan _δ∥ )/(2ε _r⊥ + ε _r∥ ).
Here, "εr" is the dielectric constant, "tan δ" is the dielectric tangent, the subscript "∥" indicates the component parallel to the alignment direction of the liquid crystal, and "⊥" indicates the component perpendicular to the alignment direction of the liquid crystal.

Δε _r and tan δ _iso can be measured by the following method.
First, a liquid crystal composition is introduced into a capillary tube made of polytetrafluoroethylene (PTFE).
The capillary used here has an inner radius of 0.80 mm and an outer radius of 0.835 mm, with an effective length of 4.0 cm.
The capillary tube containing the liquid crystal composition is introduced into the center of a cavity resonator (manufactured by EM Lab Co., Ltd.) having a resonance frequency of 10 GHz.
The cavity has an outer diameter of 30 mm and a width of 26 mm.
A signal is then input, and the result of the output signal is recorded using a network analyzer (manufactured by Keysight Technologies, Inc.).
The dielectric constant (ε _r ) and loss angle (δ) at 10 GHz are determined using the difference between the resonance frequency of a PTFE capillary tube containing no liquid crystal composition and the resonance frequency of a PTFE capillary tube containing a liquid crystal composition.
The tangent of the obtained δ is the dielectric tangent (tan δ).
The resonance frequency and the like using a PTFE capillary tube filled with a liquid crystal composition are determined as values of characteristic components perpendicular and parallel to the alignment direction of the liquid crystal molecules by controlling the alignment of the liquid crystal molecules.
The magnetic field of a permanent magnet or electromagnet is used to align the liquid crystal molecules in the vertical direction (perpendicular to the effective length direction) or in the parallel direction (parallel to the effective length direction) of the PTFE capillary tube.
The magnetic field has, for example, a pole-to-pole distance of 45 mm and a magnetic field strength of 0.23 Tesla near the center.
The PTFE capillary tube containing the liquid crystal composition is rotated parallel or perpendicular to the magnetic field to obtain the desired characteristic components.
The measurements were carried out at a temperature of 25° C., and both Δε _r and tan δ _iso have no unit.

The _Δεr at 25° C. of the liquid crystal composition according to the present invention is preferably larger, and from the viewpoint of phase modulation power in the GHz band, it is preferably 0.90 or more, more preferably 0.90 to 1.50, more preferably 0.95 to 1.40, and even more preferably 1.00 to 1.35.
The tan δ _iso at 25° C. of the liquid crystal composition according to the present invention is preferably smaller, and from the viewpoint of loss in the GHz band, it is preferably 0.025 or less, more preferably 0.001 to 0.025, more preferably 0.003 to 0.020, more preferably 0.005 to 0.017, more preferably 0.007 to 0.015, more preferably 0.008 to 0.013, and more preferably 0.009 to 0.012.

(Liquid crystal display elements, sensors, liquid crystal lenses, optical communication devices and antennas)
A liquid crystal display element, a sensor, a liquid crystal lens, an optical communication device, and an antenna using the liquid crystal composition according to the present invention will be described below.

The liquid crystal display element according to the present invention is characterized by using the above-mentioned liquid crystal composition, and is preferably driven by an active matrix system or a passive matrix system.
The liquid crystal display element according to the present invention is preferably a liquid crystal display element in which the dielectric constant is reversibly switched by reversibly changing the alignment direction of the liquid crystal molecules of the above-mentioned liquid crystal composition.

The sensor according to the present invention is characterized by using the above-mentioned liquid crystal composition, and examples of its embodiments include a distance measuring sensor that uses electromagnetic waves, visible light or infrared light, an infrared sensor that uses a change in temperature, a temperature sensor that uses a change in the wavelength of reflected light due to a change in the pitch of a cholesteric liquid crystal, a pressure sensor that uses a change in the wavelength of reflected light, an ultraviolet sensor that uses a change in the wavelength of reflected light due to a change in composition, an electrical sensor that uses a change in temperature due to a voltage or current, a radiation sensor that uses a temperature change accompanying the track of a radiation particle, an ultrasonic sensor that uses a change in the arrangement of liquid crystal molecules due to mechanical vibration of ultrasonic waves, and an electromagnetic field sensor that uses a change in the wavelength of reflected light due to a change in temperature or a change in the arrangement of liquid crystal molecules due to an electric field.
The distance measurement sensor is preferably for use in LiDAR (Light Detection and Ranging) that uses a light source.
LiDAR is preferably used for artificial satellites, aircraft, unmanned aerial vehicles (drones), automobiles, railways, and ships.
For automobiles, self-driving automobiles are particularly preferred.
The light source is preferably an LED or a laser, preferably a laser.
The light used in LiDAR is preferably infrared light, and its wavelength is preferably 800 to 2000 nm.
In particular, an infrared laser with a wavelength of 905 nm or 1550 nm is preferred.
When the cost of the photodetector to be used and sensitivity in all weather conditions are important, a 905 nm infrared laser is preferred, whereas when safety regarding human vision is important, a 1550 nm infrared laser is preferred.
The liquid crystal composition according to the present invention exhibits a high Δn value, and therefore has a large phase modulation power in the visible light, infrared light and electromagnetic wave regions, and can provide a sensor with excellent detection sensitivity.

The liquid crystal lens according to the present invention is characterized by using the above-mentioned liquid crystal composition, and for example, in one embodiment thereof, has a first transparent electrode layer, a second transparent electrode layer, a liquid crystal layer containing the above-mentioned liquid crystal composition provided between the first transparent electrode layer and the second transparent electrode layer, an insulating layer provided between the second transparent electrode layer and the liquid crystal layer, and a high-resistance layer provided between the insulating layer and the liquid crystal layer.
The liquid crystal lens according to the present invention is used, for example, as a 2D/3D switching lens, a lens for adjusting the focus of a camera, and the like.

The optical communication device according to the present invention is characterized by using the above-mentioned liquid crystal composition. For example, one of the embodiments of the optical communication device is a liquid crystal on silicon (LCOS) having a configuration in which a liquid crystal layer in which liquid crystals constituting each of a plurality of pixels are two-dimensionally arranged on a reflective layer (electrode).
The optical communication device according to the present invention is used, for example, as a spatial phase modulator.

The antenna according to the present invention is characterized by using the above-mentioned liquid crystal composition.
More specifically, the antenna of the present invention comprises a first substrate having a plurality of slots, a second substrate facing the first substrate and having a power supply section, a first dielectric layer provided between the first substrate and the second substrate, a plurality of patch electrodes arranged corresponding to the plurality of slots, a third substrate having the patch electrodes provided thereon, and a liquid crystal layer provided between the first substrate and the third substrate, wherein the liquid crystal layer contains the above-mentioned liquid crystal composition.
By using the liquid crystal composition according to the present invention, it is possible to provide an antenna that is highly reliable against external stimuli such as heat.
This makes it possible to provide an antenna that allows greater phase control for microwave or millimeter wave electromagnetic waves.
Preferably, the antenna according to the invention operates in the Ka or K or Ku band frequencies used for satellite communications.
The antenna according to the present invention preferably has a configuration in which a radial line slot array and a patch antenna array are combined.
The structure of the antenna according to the present invention can be applied by taking into consideration the matters described in, for example, International Publication No. 2021/157189.

The present invention will be further described below with reference to examples, but the present invention is not limited to these examples.
The compositions of the following Examples and Comparative Examples contained each compound in the proportions shown in the table, and the contents are shown in "mass %".
In addition, compounds which can take either cis or trans form will represent the trans form unless otherwise specified.
Example 1: Preparation of the compound represented by formula (I-1)

Under a nitrogen atmosphere, 30.0 g of the compound represented by formula (I-1-1), 0.75 g of copper iodide (I), 1.5 g of bis(triphenylphosphine)palladium (II) dichloride, 50 mL of triethylamine, and 100 mL of tetrahydrofuran were added to a reaction vessel. Next, while stirring at room temperature, a solution in which 20 g of the compound represented by formula (I-1-2) was dissolved in 100 mL of tetrahydrofuran was dropped and stirred at room temperature for 2 hours. After the reaction was completed, 10% by mass hydrochloric acid was poured into the reaction solution and extracted with toluene. The organic layer was washed with saline, and then purified by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane = 1/3) to obtain 29.0 g of the compound represented by formula (I-1-3).
Next, under a nitrogen atmosphere, 29.0 g of the compound represented by formula (I-1-3), 0.7 g of copper iodide (I), 1.25 g of bis(triphenylphosphine)palladium (II) dichloride, 50 mL of triethylamine, and 150 mL of N,N-dimethylformamide were added to the reaction vessel. Then, while heating at 70° C., a solution in which 8.4 g of trimethylsilylacetylene was dissolved in 25 mL of N,N-dimethylformamide was dropped, and the mixture was stirred at 70° C. for 2 hours. After the reaction was completed, 10% by mass hydrochloric acid was poured into the reaction liquid, and the mixture was extracted with toluene. The organic layer was washed with saline, and then column chromatography (silica gel, toluene) and solvent distillation were performed. Further, 10 g of potassium carbonate was added, and 200 ml of methanol was added, and the reaction vessel was heated to 50° C. and reacted for 2 hours. Then, the reaction liquid was extracted with toluene, and the organic layer was washed with saline, and then column chromatography (silica gel, toluene) and solvent distillation were performed. Next, 16.5 g of 4-bromo-2-fluoroaniline, 0.65 g of copper (I) iodide, 2.0 g of tetrakis (triphenylphosphine) palladium, 50 mL of triethylamine, and 150 mL of N,N-dimethylformamide were added to the reaction mixture. The reaction vessel was heated to 85°C and stirred for an additional 3 hours. After the reaction was completed, a saturated aqueous solution of ammonium chloride was poured into the reaction mixture, which was then extracted with ethyl acetate. The organic layer was washed with saline and then recrystallized from toluene to obtain 9.3 g of the compound represented by formula (I-1-4).
27 g of the compound represented by formula (I-1-4), 100 ml of dichloromethane, and 23 g of 1,1-thiocarbonyldiimidazole were added to a reaction vessel and heated under reflux for 2 hours. After completion of the reaction, the organic layer was washed with saline and then purified by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane=2/1) to obtain 25.5 g of the compound represented by formula (I-1).
MS (EI): m/z=433
Example 2: Preparation of the compound represented by formula (I-2)

Under a nitrogen atmosphere, 28.0 g of the compound represented by formula (I-2-1), 0.75 g of copper (I) iodide, 2.0 g of tetrakis (triphenylphosphine) palladium, 50 mL of triethylamine, and 150 mL of N,N-dimethylformamide were added to a reaction vessel. While heating the reaction vessel at 85°C, a solution in which 20.0 g of the compound represented by formula (I-2-2) was dissolved in 50 mL of N,N-dimethylformamide was dropped and stirred at 85°C for 3 hours. After the reaction was completed, a saturated aqueous ammonium chloride solution was poured into the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated saline, and then 28 g of the compound represented by formula (I-2-3) was obtained by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane = 3/1).
Next, 28 g of the compound represented by formula (I-2-3), 100 ml of dichloromethane, and 18 g of 1,1-thiocarbonyldiimidazole were added to a reaction vessel and heated under reflux for 2 hours. After completion of the reaction, the organic layer was washed with saturated saline and then purified by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane=2/1) to obtain 28.5 g of the compound represented by formula (I-2).
MS (EI): m/z=413
Example 3: Preparation of the compound represented by formula (I-3)

Under a nitrogen atmosphere, 22.0 g of the compound represented by formula (I-3-1), 1.1 g of tetrakis(triphenylphosphine)palladium, 20 g of potassium carbonate, 14 g of p-hydroxyphenylboric acid, 150 mL of tetrahydrofuran, and 25 mL of water were added to a reaction vessel, and the reaction vessel was heated to 70° C. After completion of the reaction, 10% by mass hydrochloric acid was poured into the reaction liquid, and the liquid was extracted with ethyl acetate. The organic layer was washed with saturated saline, and then the solvent was distilled off, and dispersion washing with hexane was performed to obtain 20 g of the compound represented by formula (I-3-2).
Next, in a nitrogen atmosphere, 20 g of the compound represented by formula (I-3-2), 150 ml of dichloromethane, and 10 g of pyridine were added to a reaction vessel, and the mixture was cooled to 10° C. or lower in an ice-water bath. Then, 50 mL of a dichloromethane solution containing 25 g of trifluoromethanesulfonic anhydride was slowly added dropwise. After the addition was completed, the mixture was stirred at room temperature for 2 hours. After the reaction was completed, 10% by mass hydrochloric acid was poured into the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with saline, and then the solvent was distilled off, and the mixture was purified by column chromatography (silica gel, hexane) to obtain 30.0 g of the compound represented by formula (I-3-3).
Further, under a nitrogen atmosphere, 30.0 g of the compound represented by formula (I-3-3), 0.6 g of copper (I) iodide, 1.5 g of tetrakis (triphenylphosphine) palladium, 75 mL of triethylamine, and 150 mL of N,N-dimethylformamide were added to the reaction vessel. While heating the reaction vessel at 85°C, a solution in which 14.7 g of the compound represented by formula (I-3-4) was dissolved in 50 mL of N,N-dimethylformamide was dropped, and the mixture was stirred at 85°C for 3 hours. After the reaction was completed, a saturated aqueous ammonium chloride solution was poured into the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with saline, and then 23.7 g of the compound represented by formula (I-3-5) was obtained by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane = 3/1).
Next, 23.7 g of the compound represented by formula (I-3-5), 100 ml of dichloromethane, and 18 g of 1,1-thiocarbonyldiimidazole were added to a reaction vessel and heated under reflux for 2 hours. After completion of the reaction, the organic layer was washed with saturated saline and then purified by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane=2/1) to obtain 22.5 g of the compound represented by formula (I-3).
MS (EI): m/z=427
Example 4: Preparation of compound represented by formula (I-4)

Under a nitrogen atmosphere, 10.0 g of the compound represented by formula (I-4-1), 6.4 g of the compound represented by formula (I-4-2), 0.3 g of tetrakis(triphenylphosphine)palladium, 5 g of potassium carbonate, 50 mL of tetrahydrofuran, and 10 mL of water were added to a reaction vessel, and the reaction vessel was heated to 70° C. After the reaction was completed, 10% by mass hydrochloric acid was poured into the reaction solution, and the solution was extracted with ethyl acetate. The organic layer was washed with saturated saline, and the solvent was distilled off, followed by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane=1/1) to obtain 7.2 g of the compound represented by formula (I-4-3).
Next, 7.2 g of the compound represented by formula (I-4-3), 50 ml of dichloromethane, and 5.4 g of 1,1-thiocarbonyl-di-2(1H)pyridone were added to a reaction vessel and reacted at room temperature for 2 hours. After completion of the reaction, the organic layer was washed with saturated saline and then purified by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane=2/1) to obtain 6.6 g of the compound represented by formula (I-4).
MS (EI): m/z=413
(Example 5) Preparation of the compound represented by formula (I-5)

Under a nitrogen atmosphere, 15.0 g of the compound represented by formula (I-5-1), 0.6 g of tetrakis(triphenylphosphine)palladium, 12 g of potassium carbonate, 8 g of 4-(formylphenyl)boric acid, 100 mL of tetrahydrofuran, and 15 mL of water were added to a reaction vessel, and the reaction vessel was heated to 70° C. After completion of the reaction, 10% by mass hydrochloric acid was poured into the reaction liquid, and the liquid was extracted with ethyl acetate. The organic layer was washed with saturated saline, and then the solvent was distilled off, and dispersion washing with hexane was performed to obtain 12.5 g of the compound represented by formula (I-5-2).
Next, in a nitrogen atmosphere, 57 g of the compound represented by formula (I-5-3) and 150 mL of tetrahydrofuran were added to a reaction vessel, and the reaction solution was cooled to 0° C. or lower. 7 g of potassium tertiary butoxide was added, and the mixture was stirred for 30 minutes. 150 ml of dichloromethane and 10 g of pyridine were added, and the mixture was cooled to 10° C. or lower in an ice-water bath. Then, 50 mL of a tetrahydrofuran solution in which 12.5 g of the compound represented by formula (I-5-2) was dissolved was slowly added dropwise. After the addition was completed, the mixture was stirred at room temperature for 2 hours. After the reaction was completed, 10% by mass hydrochloric acid was poured into the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated saline, and the solvent was removed by distillation, and 15.5 g of the compound represented by formula (I-5) was obtained by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane=2/1).
MS (EI): m/z=422
(Example 6) Preparation of compound represented by formula (I-6)

The compound represented by formula (I-6) was produced in the same manner as in Example 2, except that the compound represented by formula (I-2-1) was replaced by 4-bromo-3-fluoroaniline, and the compound represented by formula (I-2-2) was replaced by the compound represented by formula (I-6-1).
MS (EI): m/z=333
(Example 7) Preparation of compound represented by formula (I-7)

Under a nitrogen atmosphere, 10.0 g of the compound represented by formula (I-7-1), 6.6 g of the compound represented by formula (I-7-2), 300 mg of tetrakis(triphenylphosphine)palladium, 5.5 g of potassium carbonate, 75 mL of tetrahydrofuran, and 10 mL of water were added to a reaction vessel, and the reaction vessel was heated to 70° C. After completion of the reaction, a saturated aqueous solution of ammonium chloride was poured into the reaction solution, and the solution was extracted with ethyl acetate. The organic layer was washed with saturated saline, and then recrystallized from toluene to obtain 8.0 g of the compound represented by formula (I-7-3).
Next, 8.0 g of the compound represented by formula (I-7-3), 40 ml of dichloromethane, and 3.6 g of 1,1-thiocarbonyldiimidazole were added to a reaction vessel and heated under reflux for 2 hours. After completion of the reaction, the organic layer was washed with saturated saline and then purified by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane=3/1) to obtain 8.8 g of the compound represented by formula (I-7).
MS (EI): m/z=453
(Example 8) Preparation of compound represented by formula (I-8)

Under a nitrogen atmosphere, 27.0 g of the compound represented by formula (I-8-1), 0.75 g of copper iodide (I), 2.1 g of tetrakis (triphenylphosphine) palladium, 75 mL of triethylamine, and 100 mL of N,N-dimethylformamide were added to a reaction vessel. While heating the reaction vessel at 85°C, a solution in which 22.0 g of the compound represented by formula (I-8-2) was dissolved in 50 mL of N,N-dimethylformamide was dropped and stirred at 85°C for 6 hours. After the reaction was completed, a saturated aqueous ammonium chloride solution was poured into the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated saline, and then purified by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane = 2/1) to obtain 30.5 g of the compound represented by formula (I-8).
MS (EI): m/z=391
(Example 9) Preparation of compound represented by formula (I-9)

Under a nitrogen atmosphere, 29.0 g of the compound represented by formula (I-9-1), 0.75 g of copper iodide (I), 2.0 g of tetrakis (triphenylphosphine) palladium, 50 mL of triethylamine, and 150 mL of N,N-dimethylformamide were added to a reaction vessel. While heating the reaction vessel at 85 ° C., a solution in which 24.0 g of the compound represented by formula (I-9-2) was dissolved in 50 mL of N,N-dimethylformamide was dropped, and the mixture was stirred at 85 ° C. for 3 hours. After the reaction was completed, a saturated aqueous ammonium chloride solution was poured into the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated saline, and then 33 g of the compound represented by formula (I-9-3) was obtained by column chromatography (silica gel, toluene) and recrystallization (toluene / hexane = 3 / 1).
Next, 33 g of the compound represented by formula (I-9-4), 120 ml of dichloromethane, and 22 g of 1,1-thiocarbonyl-di-2(1H)pyridone were added to a reaction vessel and reacted at room temperature for 2 hours. After completion of the reaction, the organic layer was washed with saturated saline and then purified by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane=2/1) to obtain 28 g of the compound represented by formula (I-9).
MS (EI): m/z=463
(Example 10) Preparation of compound represented by formula (I-10)

Under a nitrogen atmosphere, 29.0 g of the compound represented by formula (I-10-1), 0.75 g of copper iodide (I), 2.0 g of tetrakis (triphenylphosphine) palladium, 50 mL of triethylamine, and 150 mL of N,N-dimethylformamide were added to a reaction vessel. While heating the reaction vessel at 85 ° C., a solution in which 20.0 g of the compound represented by formula (I-10-2) was dissolved in 50 mL of N,N-dimethylformamide was dropped, and the mixture was stirred at 85 ° C. for 3 hours. After the reaction was completed, a saturated aqueous ammonium chloride solution was poured into the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated saline, and then 31 g of the compound represented by formula (I-10-3) was obtained by column chromatography (silica gel, toluene) and recrystallization (toluene / hexane = 3 / 1).
Next, 33 g of the compound represented by formula (I-10-3), 120 ml of dichloromethane, and 21 g of 1,1-thiocarbonyl-di-2(1H)pyridone were added to a reaction vessel and reacted at room temperature for 2 hours. After completion of the reaction, the organic layer was washed with saturated saline and then purified by column chromatography (silica gel, toluene) and recrystallization (toluene/hexane=2/1) to obtain 23 g of the compound represented by formula (I-10).
MS (EI): m/z=445

(Preparation and Evaluation of Liquid Crystal Composition)
A base liquid crystal (LC-1) was prepared, which exhibited the following physical properties. All values were actually measured.
T _n-i (nematic phase-isotropic liquid phase transition temperature): 74.0° C.
Δε (dielectric anisotropy at 25 ° C. and 1 kHz): 5.11
Δn (refractive index anisotropy at 25° C. and 589 nm): 0.141
γ ₁ (rotational viscosity coefficient at 25° C.): 107 mPa·s

Compounds (I-1) to (I-10) obtained in the Examples and compounds represented by formulas (C-1) to (C-2) not adopting an indene structure were added to a base liquid crystal (LC-1) to prepare liquid crystal compositions containing each compound in an amount of 0 mass %, 5 mass %, or 10 mass % based on 100 mass % of the liquid crystal composition.
The least squares method was used to determine the extrapolated values of Δn and _Δεr at 100% by mass of each compound. The results are shown in Table 1.

(Storage stability test)
Compounds (I-1) to (I-10) obtained in the Examples and compounds represented by formulas (C-1) to (C-2) not adopting an indene structure were added to a base liquid crystal (LC-1) to prepare liquid crystal compositions containing 5% by mass of each compound in 100% by mass of the liquid crystal composition.
0.5 g of the prepared liquid crystal composition was weighed into a 1 mL sample bottle (manufactured by Maruemu Co., Ltd.) and degassed for 10 minutes at 150°C and 250 Pa. The bottle was then purged with dry nitrogen and the attached lid was placed on. This was stored in a temperature-controlled thermostatic chamber (SH-241, manufactured by Espec Corp.) at 0°C for two weeks, and the occurrence of crystallization of the liquid crystal composition was visually confirmed every week. Those in which no crystallization was visually confirmed after the first week were marked with "◯", and those in which crystallization was confirmed were marked with "X". The results are shown in Table 1.

From Example 13, Comparative Example 1, Example 16 and Comparative Example 2, it was confirmed that the compound represented by general formula (i) having a specific side chain structure including an indene structure and an isothiocyanate group (-NCS) group has large Δn and Δε _r .
In particular, the compounds having an isothiocyanate group (-NCS) exhibited a Δn of 0.35 or more.
It was also confirmed that the compound represented by general formula (i) having a specific side chain structure including an indene structure and an isothiocyanate group (-NCS) group has good storage stability at low temperatures.

In addition, LC-01 to LC-02 shown in Table 4 were prepared using the compound represented by general formula (i).
The compounds are described using the following abbreviations, and compounds which can take either cis or trans form are represented as trans forms unless otherwise specified.
<Ring structure>

<Terminal structure>

（ただし、表中のｎは自然数である。）

(However, n in the table is a natural number.)

<Interlocking structure>

（ただし、表中のｎは自然数である。）

(However, n in the table is a natural number.)

(Hindered phenol antioxidant)

(Hindered amine light stabilizer)

(Examples 18 to 31)
Liquid crystal compositions shown in Tables 5 to 7 were prepared using LC-01 to 02, hindered phenol antioxidants (XX-1) to (XX-3), and hindered amine light stabilizers (YY-1) to (YY-2), and the physical properties of the compositions were measured and a storage stability test was performed. The results are shown in Tables 5 to 7.
<Storage test>
0.5 g of the liquid crystal composition was weighed into a 1 mL sample bottle (manufactured by Maruemu Co., Ltd.), and degassed for 10 minutes at 150 to 250 Pa. After that, the bottle was purged with dry nitrogen and the attached lid was placed on the bottle. This was stored in a temperature-controlled thermostatic chamber (SH-241, manufactured by Espec Corp.) at 25°C for two weeks, and the occurrence of crystallization of the liquid crystal composition was visually confirmed every week.

From Examples 18 to 19, the liquid crystal compositions using the compound represented by general formula (i) had high T _ni , large Δn, large Δε _r , small tan δ _iso , and good storage stability at room temperature.
Furthermore, from Examples 20 to 31, it was confirmed that even when a hindered phenol-based antioxidant or a hindered amine-based light stabilizer was used in combination, T _ni was high, Δn was large, Δε _r was large, tan δ _iso was small, and storage stability at room temperature was good.

The compounds of the present invention can be used in liquid crystal compositions, liquid crystal display elements, sensors, liquid crystal lenses, optical communication devices and antennas.

Claims (9)

The following general formula (i)

(In the general formula (i),
The dashed lines represent the positions of the double bonds.
R ⁱ¹ represents an alkyl group having 1 to 20 carbon atoms;
one or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -CO- and/or -CS-;
one or more -CH ₂ -CH ₂ - in the alkyl group may each independently be substituted by -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH-, -NH-CO-, -CH=CH-, -CF=CF- and/or -C≡C-;
One or more hydrogen atoms in the alkyl group may be independently substituted with a halogen atom.
Oxygen atoms do not bond directly to each other,
X ⁱ¹ represents a fluorine atom, a cyano group, or an isothiocyanate group;
A ⁱ¹ represents a 1,4-phenylene group (in which one -CH= or two or more non-adjacent -CH= groups may be replaced by -N=) or a naphthalene-2,6-diyl group;
A ⁱ² represents a 1,4-phenylene group;
One or more hydrogen atoms in A ⁱ¹ and A ⁱ² may each independently be substituted by a substituent S ⁱ¹ ;
the substituent S ⁱ¹ represents any one of a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a trimethylsilyl group, a dimethylsilyl group, a thioisocyano group, and an alkyl group having 1 to 20 carbon atoms;
One or more -CH ₂ - in the alkyl group may each independently be substituted with -O-, -S- and/or -CO-;
one or more -CH ₂ -CH ₂ - in the alkyl group may each independently be substituted by -CH=CH-, -CF=CF-, -C≡C-, -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH- and/or -NH-CO-;
One or more hydrogen atoms in the alkyl group may be independently substituted with a halogen atom.
Oxygen atoms do not bond directly to each other,
When there are a plurality of substituents S ⁱ¹ , they may be the same or different.
L ⁱ¹ and L ⁱ² each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfanyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, a methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a trimethylsilyl group, a dimethylsilyl group, a thioisocyano group, or an alkyl group having 1 to 20 carbon atoms;
One or more -CH ₂ - in the alkyl group may each independently be substituted by -O-, -S-, -CO- and/or -CS-;
one or more -CH ₂ -CH ₂ - in the alkyl group may each independently be substituted by -CH=CH-, -CF=CF-, -C≡C-, -CO-O-, -O-CO-, -CO-S-, -S-CO-, -CO-NH- and/or -NH-CO-;
One or more hydrogen atoms in the alkyl group may be independently substituted with a halogen atom.
Oxygen atoms do not bond directly to each other,
Z ⁱ¹ and Z ⁱ² each independently represent a single bond, -CH=CH-, -C≡C-, a group represented by formula (Z ^i1/2 -5), a group represented by formula (Z ^i1/2 -6), a group represented by formula (Z ^i1/2 -11), a group represented by formula (Z ^i1/2 -12), or a group represented by formula (Z ^i1/2 -13);

( In formula (Z ^i1/2 -5), formula (Z ^i1/2 -6), formula (Z ^i1/2 -11), formula (Z ^i1/2 -12) or formula (Z ^i1/2 -13),
The white dots represent bonds to the indene structure, A ⁱ¹ or A ⁱ² .
The black dots represent bonds to A ⁱ¹ or A ⁱ² .
n ⁱ¹ represents an integer of 0 to 3,
When a plurality of A ⁱ² or Z ⁱ² are present, they may be the same or different.
A compound represented by the formula: The compound represented by the general formula (i) is represented by the following general formulas (i-1) , (i-2), (i-3), (i-4), (i-5), (i-6), (i-8), (i-9), (i-10) and (i-11):

(In general formulas (i-1) , (i-2), (i-3), (i-4), (i-5), (i-6), (i-8), (i-9), (i-10) and (i-11),
The dashed line, R ⁱ¹ , L ⁱ¹ , L ⁱ² , A ⁱ¹ , A ⁱ² and X ⁱ¹ have the same meanings as R ⁱ¹ , L ⁱ¹ , L ⁱ² , A ⁱ¹ , A ⁱ² and X ⁱ¹ in the general formula (i) above.
2. The liquid crystal composition according to claim 1, wherein the compound is selected from the group consisting of compounds represented by the following formula: A liquid crystal composition comprising one or more compounds according to claim 1 or 2. A liquid crystal display device using the liquid crystal composition according to claim 3 . A sensor using the liquid crystal composition according to claim 3 . A liquid crystal lens using the liquid crystal composition according to claim 3 . An optical communication device using the liquid crystal composition according to claim 3 . An antenna using the liquid crystal composition according to claim 3 . 9. An antenna as claimed in claim 8 ,
a first substrate having a plurality of slots;
a second substrate facing the first substrate and provided with a power supply unit;
a first dielectric layer provided between the first substrate and the second substrate;
A plurality of patch electrodes arranged corresponding to the plurality of slots;
a third substrate on which the patch electrode is provided;
a liquid crystal layer provided between the first substrate and the third substrate;
An antenna, wherein the liquid crystal layer contains the liquid crystal composition according to claim 3 .