Liquid crystal compounds, and liquid crystal compositions and devices containing the same.

Abstract

To provide a liquid crystal compound having a novel structure and exhibiting ferroelectricity.SOLUTION: Provided is a liquid crystal compound represented by formula (1-1) or formula (2-1).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This invention relates to liquid crystal compounds, as well as liquid crystal compositions and devices containing them. [Background technology]

[0002] Traditionally, liquid crystal compounds have been used in applications such as liquid crystal displays due to their property of aligning in a specific direction in the presence of an electric field, i.e., exhibiting dielectric anisotropy.

[0003] In recent years, it has been reported that liquid crystal compounds possessing a permanent dipole moment of a certain magnitude or greater in a specific direction exhibit ferroelectricity, meaning they polarize even in the absence of an external electric field. Such ferroelectric liquid crystal compounds have properties such as high relative permittivity and dielectric anisotropy, hysteresis in the relationship between the electric field and polarization, and reversible reversal of polarization by changing the direction of the external electric field. For these reasons, ferroelectric liquid crystal compounds can be suitably used in applications such as liquid crystal displays, optical devices, memory media, and sensors.

[0004] As an example of a liquid crystal compound exhibiting such ferroelectricity, Patent Document 1 describes compound DIO-3, which has the following structure. [ka]

[0005] According to Patent Document 1, the compound DIO-3 exhibits, for example, a very large relative permittivity of about 10,000 in the temperature range of 48 to 66°C and the frequency range of 1 Hz to 1 kHz. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2017-145298 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Although the compound described in Patent Document 1 exhibits a very high dielectric constant, its synthesis is not necessarily easy. For example, the 1,3-dioxane ring in the compound described in Patent Document 1 is formed by reacting the corresponding aldehyde and 1,3-diol (acetalization reaction), but these aldehydes and 1,3-diols are not inexpensive, which may limit the synthesis of analogues. Furthermore, among the geometric isomers (cis and trans) obtained by the acetalization reaction, it is necessary to purify the trans isomer, which exhibits higher ferroelectricity (separation and removal of the cis isomer), which can increase manufacturing costs. For this reason, there is a need for liquid crystal compounds exhibiting ferroelectricity with novel structures.

[0008] Therefore, the present invention provides liquid crystal compounds and the like that exhibit ferroelectric properties with a novel structure. [Means for solving the problem]

[0009] The present invention is, for example, as follows:

[0010] [1] The following formula (1-1) or formula (1-2): [ka] (In the above formula, R 1 This is a hydrogen atom, a polymerizable group, and an alkyl group having 1 to 20 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-, and any hydrogen atom in the alkyl group may be replaced with a halogen. X is hydrogen, a polymerizable group, halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, or an alkyl group having 1 to 3 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced by -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. Any hydrogen in the alkyl group may be replaced by halogen, and -CH3 in the alkyl group may be replaced by -CN. Ar 1 , Ar 2 , Ar 3 , Ar 4 , and Ar 5 are each independently a substituted or unsubstituted arylene or a substituted or unsubstituted heteroarylene. A 1 , A 2 , and A 3 are each independently a single bond or an alkylene having 1 to 8 carbon atoms. Any -CH2- in the alkylene may be replaced by -O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N=N-, -CH=N-, -N=CH-, -N(O)=N-, -N=N(O)-, -CH=CH-, -CF=CF-, or -C≡C-. Any hydrogen in the alkylene may be replaced by halogen. n and m are each independently 0 or 1) A liquid crystal compound represented by [2] The following formula (1-2) or formula (2-2): [Chemical formula] (In the above formula, R 1 is hydrogen, a polymerizable group, or an alkyl group having 1 to 20 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced by -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. Any hydrogen in the alkyl group may be replaced by halogen. R 2These are, independently, a polymerizable group, a halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, and an alkyl group having 1 to 3 carbon atoms, where any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-, any hydrogen in the alkyl group may be replaced with a halogen, and any -CH3 in the alkyl group may be replaced with -CN. X is hydrogen, a polymerizable group, a halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, or an alkyl group having 1 to 3 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-, any hydrogen in the alkyl group may be replaced with a halogen, and any -CH3 in the alkyl group may be replaced with -CN. A 3 This is an alkylene with a single bond and 1 to 8 carbon atoms, and any -CH2- in the alkylene may be replaced with -O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N=N-, -CH=N-, -N=CH-, -N(O)=N-, -N=N(O)-, -CH=CH-, -CF=CF-, -C≡C-, and any hydrogen in the alkylene may be replaced with a halogen. (Each p is an independent integer between 0 and 4.) The liquid crystal compound described above [1], represented by [1]. [3] Equations (1-3) to (2-4) below: [ka] (In the above formula, R 1 This is a hydrogen atom, a polymerizable group, and an alkyl group having 1 to 20 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-, and any hydrogen atom in the alkyl group may be replaced with a halogen. R3 These are, independently, hydrogen, a polymerizable group, a halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, and an alkyl group having 1 to 3 carbon atoms, where any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-, any hydrogen in the alkyl group may be replaced with a halogen, and any -CH3 in the alkyl group may be replaced with -CN. X is hydrogen, a polymerizable group, a halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, or an alkyl group having 1 to 3 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-, any hydrogen in the alkyl group may be replaced with a halogen, and any -CH3 in the alkyl group may be replaced with -CN. The liquid crystal compound described above [1], represented by [1]. [4] Equations (1) to (13) below: [ka] The liquid crystal compound described above [1], represented by [1]. [5] A liquid crystal compound according to any of [1] to [4] above, wherein the relative permittivity is 1000 or more. [6] A liquid crystal compound according to any of [1] to [5] above, wherein the dipole moment is 8.5D or less. [7] A liquid crystal composition comprising any of the liquid crystal compounds described in [1] to [6] above. [8] A liquid crystal composition comprising two or more liquid crystal compounds as described in any of [1] to [6] above. [9] The liquid crystal composition according to [7], further comprising a liquid crystal compound with a relative permittivity of less than 1000.

[10] The liquid crystal composition according to [8] above, further comprising a liquid crystal compound with a relative permittivity of less than 1000.

[11] A device comprising a liquid crystal compound as described in any of [1] to [6] above or a liquid crystal composition as described in any of [7] to

[10] above.

[12] The element according to

[11] , further comprising a voltage application section. [Effects of the Invention]

[0011] The present invention provides liquid crystal compounds exhibiting ferroelectricity of a novel structure. These liquid crystal compounds may have at least one of the following effects: inexpensive synthesis of a variety of analogs, high yield production, high relative permittivity, hysteresis phenomenon in the relationship between electric field and polarization, and reversible reversal of polarization by changing the direction of the external electric field. [Brief explanation of the drawing]

[0012] [Figure 1] These are polarized light microscope (POM) images of the A phase of the liquid crystal compounds of Examples 1 to 4, measured using an unoriented cell. Figure 1A shows the ferroelectric nematic phase (NF phase) of the liquid crystal compound of Example 1. Figure 1B shows the ferroelectric nematic phase (NF phase) of the liquid crystal compound of Example 2. Figure 1C shows the ferroelectric nematic phase (NF phase) of the liquid crystal compound of Example 3. Figure 1D shows the ferroelectric smectic phase (SmF phase) of the liquid crystal compound of Example 4. [Figure 2] Figure 2A shows the electric flux density-electric field (DE) curves of the liquid crystal compounds of Examples 1 to 4. Figure 2A shows the DE curve of the liquid crystal compound of Example 1 (frequency: 100 Hz). Figure 2B shows the DE curve of the liquid crystal compound of Example 2 (frequency: 200 Hz). Figure 2C shows the DE curve of the liquid crystal compound of Example 3 (frequency: 100 Hz). Figure 2D shows the DE curve of the liquid crystal compound of Example 4 (frequency: 10 Hz). [Figure 3] This is a logarithmic graph showing the relationship between relative permittivity and temperature at a frequency of 1000 Hz for the liquid crystal compounds of Examples 1 to 4. [Figure 4]This figure shows the change in phase transition temperature of the liquid crystal compositions of Examples 14 to 19. Figure 4A shows data for Example 2, Examples 14 to 16, and Example 3 (horizontal axis: liquid crystal compound content of Example 3, vertical axis: phase transition temperature). Figure 4B shows data for Example 15, Examples 17 to 19, and Comparative Example 5 (horizontal axis: liquid crystal compound content of compound A, vertical axis: phase transition temperature). [Modes for carrying out the invention]

[0013] The embodiments for carrying out the present invention will be described in detail below.

[0014] 1.Liquid crystal compound The liquid crystal compound according to the present invention is represented by the following formula (1-1) or formula (1-2).

[0015] [ka]

[0016] In the above formula, R 1 The group consists of hydrogen, a polymerizable group, and an alkyl group having 1 to 20 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. In addition, any hydrogen in the alkyl group may be replaced with a halogen.

[0017] Examples of polymerizable groups include functional groups containing acrylic groups, methacrylic groups, vinyloxy groups, isocyanate groups, isothiocyanate groups, epoxy groups, aziridine groups, azulactone groups, chloro-s-triazine groups, or β-chloroethylaminosulfonyl groups. The polymerizable group can be represented, for example, by any of the following formulas (3-1) to (3-10). [ka]

[0018] In the above formula, L can be a single bond, methylene, ethylene, propylene, isopropylene, butylene, pentylene, hexylene, heptylene, 2-ethylhexylene, -O-, -S-, etc. Furthermore, in formula (1-1), "*" represents the linkage with the carbon atom of the carbonyl group, and in formula (2-1), it represents the linkage with the oxygen atom.

[0019] Examples of alkyl groups having 1 to 20 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, and decyl.

[0020] When any -CH2- in an alkyl group is replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-, C1- to C20 alkyl groups include: -O-;-S-;-COO-;-OCO-;-CH=CH-;-CF=CF-;-C≡C-; C1- to C20 alkoxys such as methoxy, ethoxy, propyloxy, butyloxy, and tert-butyloxy; C1- to C20 alkoxyalkyls such as methoxymethyl, methoxyethyl, methoxypropyl, ethoxymethyl, ethoxyethyl, and ethoxypropyl; methylthio, ethylthio, propylthio, isopropylthio, and butylthio Examples include C1-C20 alkylthios such as tert-butylthio; C1-C20 alkylthios such as methylthiomethyl, methylthioethyl, ethylthiomethyl, and ethylthioethyl; C1-C20 alkylcarbonyloxys such as methylcarbonyloxy and ethylcarbonyloxy; C1-C20 alkoxycarbonyls such as methoxycarbonyl and ethoxycarbonyl; C1-C20 alkenyls such as vinyl, 1-propenyl, 2-propenyl, 2-butenyl, and 3-butenyl; C1-C20 difluoroalkenyls such as 1,2-difluorovinyl; and C1-C20 alkynyls such as methylidine and propargyl.

[0021] Examples of alkyl groups with 1 to 20 carbon atoms when any hydrogen atom in the alkyl group is replaced by a halogen include fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, and bromomethyl.

[0022] Of these, R 1 The element is preferably hydrogen, an alkyl group having 1 to 20 carbon atoms, or an alkenyl group having 1 to 20 carbon atoms; more preferably an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms; even more preferably an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 1 to 5 carbon atoms; particularly preferably an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 1 to 3 carbon atoms; very preferably an alkyl group having 1 to 3 carbon atoms; and most preferably a propyl group.

[0023] X is hydrogen, a polymerizable group, a halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, or an alkyl group having 1 to 3 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. Also, any hydrogen in the alkyl group may be replaced with a halogen. Furthermore, any -CH3 in the alkyl group may be replaced with -CN.

[0024] The polymerizable group is R 1 It is similar to the polymerizable group of the above, and is specifically represented by formulas (3-1) to (3-10).

[0025] Examples of halogens include fluorine, chlorine, bromine, and iodine.

[0026] Examples of alkyl groups having 1 to 3 carbon atoms include methyl, ethyl, propyl, and isopropyl.

[0027] Examples of C1-C3 alkyl groups in which any -CH2- in the alkyl group is replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C- include: C1-C3 alkoxys such as methoxy, ethoxy, and propyloxy; C1-C3 alkoxyalkyls such as methoxymethyl, methoxyethyl, and ethoxymethyl; C1-C3 alkylthios such as methylthio, ethylthio, propylthio, and isopropylthio; and methylthiomethyl and methylthio Examples include C1-C3 alkylthios such as oethyl and ethylthiomethyl; C1-C3 alkylcarbonyloxys such as methylcarbonyloxy and ethylcarbonyloxy; C1-C3 alkoxycarbonyls such as methoxycarbonyl and ethoxycarbonyl; C1-C20 alkenyls such as vinyl, 1-propenyl, and 2-propenyl; C1-C3 difluoroalkenyls such as 1,2-difluorovinyl; and C1-C3 alkynyls such as methylidine and propargyl.

[0028] Examples of C1-C3 alkyl groups in which any hydrogen atom in the alkyl group is replaced by a halogen include fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, and bromomethyl.

[0029] Examples of alkyl groups with 1 to 3 carbon atoms in which the -CH3 group is replaced by -CN include cyanomethyl and cyanoethyl.

[0030] Of these, X is preferably halogen, -CN, -NO2, -NCO, -NCS, -CF3, or -OCF3, more preferably fluorine, -CN, -NO2, or -CF3, and particularly preferably fluorine, -CN, or -NO2. In one embodiment, X is fluorine. In one embodiment, X is -CN. In one embodiment, X is -NO2.

[0031] Ar 1 Ar 2 Ar 3Ar 4 , and Ar 5 These are, independently, substituted or unsubstituted arylenes and substituted or unsubstituted heteroarylenes.

[0032] Examples of arylenes include divalent groups derived from phenyl, naphthyl, and anthracenyl.

[0033] Examples of heteroarylenes include furan, pyrrole, imidazole, pyrazole, oxazole, isoxazole, thiazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, quinoline, isoquinoline, naphthyridine, phthalazine, quinoxaline, quinazoline, benzoxazole, benzothiazole, and divalent groups derived from carbazole.

[0034] The substituents that arylenes and heteroarylenes may have include hydrogen, polymerizable groups, halogens, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, and alkyl groups having 1 to 3 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. In addition, any hydrogen in the alkyl group may be replaced with a halogen. Furthermore, any -CH3 in the alkyl group may be replaced with -CN.

[0035] Specific examples of substituents that arylenes and heteroarylenes may have are the same as those described as X above.

[0036] Of these, Ar 1 Ar 2 Ar 3 Ar 4 , and Ar 5 Each of these is preferably independently a substituted or unsubstituted phenylene, more preferably a substituted or unsubstituted phenylene, and even more preferably represented by any of the following formulas (4-1) to (4-10). Note that "*" represents an oxygen atom, A1 ~A 5 , or the connection point with X.

[0037] [ka]

[0038] In one embodiment, Ar 1 It is preferable that the group is represented by formula (4-1). In one embodiment, Ar 2 It is preferable that the group is represented by formula (4-1). In one embodiment, Ar 3 It is preferable that the group is represented by formula (4-1) or formula (4-5). In one embodiment, Ar 4 It is preferable that the group is represented by formula (4-2) or formula (4-5). In one embodiment, Ar 5 It is preferable that the group is represented by formula (4-5).

[0039] In one preferred embodiment, Ar 3 is a group represented by formula (4-1), and Ar 4 is a group represented by formula (4-2) or formula (4-5), and Ar 5 It is preferable that the group is represented by formula (4-5), and Ar 3 is a group represented by formula (4-1), and Ar 4 is a group represented by formula (4-2), and Ar 5 It is more preferable that the base is represented by formula (4-5). In one preferred embodiment, Ar 3 is a group represented by formula (4-5), and Ar 4 is a group represented by formula (4-2) or formula (4-5), and Ar 5 It is preferable that the group is represented by formula (4-5), and Ar 3 is a group represented by formula (4-5), and Ar 4 is a group represented by formula (4-2), and Ar 5is a group represented by formula (4-5), or Ar 3 is a group represented by formula (4-5), and Ar 4 is a group represented by formula (4-5), and Ar 5 It is more preferable that the base is represented by formula (4-5).

[0040] A 1 , A 2 , and A 3 Each of these is an alkylene with a single bond and 1 to 8 carbon atoms. In this case, any -CH2- in the alkylene may be replaced with -O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N=N-, -CH=N-, -N=CH-, -N(O)=N-, -N=N(O)-, -CH=CH-, -CF=CF-, or -C≡C-. In addition, any hydrogen in the alkylene may be replaced with a halogen.

[0041] Examples of alkylenes having 1 to 8 carbon atoms include methylene, ethylene, propylene, isopropylene, butylene, pentylene, hexylene, heptylene, and 2-ethylhexylene.

[0042] Alkylenes with 1 to 8 carbon atoms in which any -CH2- in the alkylene is replaced with -O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N=N-, -CH=N-, -N=CH-, -N(O)=N-, -N=N(O)-, -CH=CH-, -CF=CF-, -C≡C- include -O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N=N-, -CH=N-, -N=CH-, -N(O)=N-, -N=N(O)-, -CH=CH-, -CF=CF -, -C≡C-, -CH2-O-, -CH2CH2-O-, -CH2CH2CH2-O-, -CH2-O-CH2-, -CH2CH2-O-CH2-, -CH2CH2-O-CH2CH2-, -CH2-S-, -CH2CH2-S-, -CH Examples include 2CH2CH2-S-, -CH2-S-CH2-, -CH2CH2-S-CH2-, -CH2CH2-S-CH2CH2-, -CH2-COO-, -CH2CH2-COO-, -CH2-OCO-, -CH2CH2-OCO-, and the like.

[0043] Of these, A 1 , A 2 , and A 3 Each of these is preferably a single bond, -O-, -COO-, and -OCO-, more preferably a single bond, -COO-, and -OCO-, and even more preferably a single bond, and -COO-. In one embodiment, A 3 It is preferably a single bond, -O-, -COO-, -OCO-, more preferably a single bond, -COO-, -OCO-, even more preferably a single bond, -COO-, and particularly preferably -COO-.

[0044] n and m are each independently 0 or 1, preferably 0.

[0045] Of the above, from the viewpoint of potentially improving dielectric properties, the compound represented by formula (1-1) is preferred.

[0046] The liquid crystal compound according to the present invention is preferably represented by the following formula (1-2) or formula (2-2). [ka]

[0047] In the above formula, R 1 This consists of hydrogen, a polymerizable group, and an alkyl group having 1 to 20 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. Any hydrogen in the alkyl group may be replaced with a halogen.

[0048] R 1 This is the same as described above in equations (1-1) and (2-1).

[0049] Of these, R 1The element is preferably hydrogen, an alkyl group having 1 to 20 carbon atoms, or an alkenyl group having 1 to 20 carbon atoms; more preferably an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms; even more preferably an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 1 to 5 carbon atoms; particularly preferably an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 1 to 3 carbon atoms; very preferably an alkyl group having 1 to 3 carbon atoms; and most preferably a propyl group.

[0050] R 2 These are, independently, a polymerizable group, a halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, and an alkyl group having 1 to 3 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. Also, any hydrogen in the alkyl group may be replaced with a halogen. Furthermore, any -CH3 in the alkyl group may be replaced with -CN.

[0051] R 2 This is the same as what is described in formulas (1-1) and (2-1) as possible substituents of arylene and heteroarylene (i.e., what is described as X).

[0052] Of these, R 2 The halogen is preferably a halogen, -CN, -NO2, -NCO, -NCS, -CF3, or -OCF3, more preferably fluorine, -CN, -NO2, or -CF3, and particularly preferably fluorine, -CN, or -NO2. In one embodiment, R 2 It is fluorine. In one embodiment, R 2 is -CN. In one embodiment, R 2 It is -NO2.

[0053] X is hydrogen, a polymerizable group, a halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, or an alkyl group having 1 to 3 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. Also, any hydrogen in the alkyl group may be replaced with a halogen. Furthermore, any -CH3 in the alkyl group may be replaced with -CN.

[0054] X is the same as the one written as X in equations (1-1) and (2-1).

[0055] Of these, X is preferably halogen, -CN, -NO2, -NCO, -NCS, -CF3, or -OCF3, more preferably fluorine, -CN, -NO2, or -CF3, and particularly preferably fluorine, -CN, or -NO2. In one embodiment, X is fluorine. In one embodiment, X is -CN. In one embodiment, X is -NO2.

[0056] A 3 This is an alkylene with a single bond and 1 to 8 carbon atoms. In this case, any -CH2- in the alkylene may be replaced with -O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N=N-, -CH=N-, -N=CH-, -N(O)=N-, -N=N(O)-, -CH=CH-, -CF=CF-, or -C≡C-. Also, any hydrogen in the alkylene may be replaced with a halogen.

[0057] A 3 In equations (1-1) and (2-1), A 3 This is the same as what was described.

[0058] Of these, A 3It is preferable that the bond is a single bond, -O-, -COO-, or -OCO-; more preferably a single bond, -COO-, or -OCO-; even more preferably a single bond, or -COO-; and particularly preferably -COO-.

[0059] Each of the variables p is an independent integer between 0 and 4, preferably between 0 and 2.

[0060] Of the above, from the viewpoint of potentially improving dielectric properties, the compound represented by formula (1-2) is preferred.

[0061] The liquid crystal compound according to the present invention is more preferably a compound represented by the following formulas (1-3) to (2-4). [ka]

[0062] In the above formula, R 1 The group consists of hydrogen, a polymerizable group, and an alkyl group having 1 to 20 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. In addition, any hydrogen in the alkyl group may be replaced with a halogen.

[0063] R 1 This is the same as described above in equations (1-1) and (2-1).

[0064] Of these, R 1 The element is preferably hydrogen, an alkyl group having 1 to 20 carbon atoms, or an alkenyl group having 1 to 20 carbon atoms; more preferably an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 1 to 10 carbon atoms; even more preferably an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 1 to 5 carbon atoms; particularly preferably an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 1 to 3 carbon atoms; very preferably an alkyl group having 1 to 3 carbon atoms; and most preferably a propyl group.

[0065] R3 These are, independently, hydrogen, a polymerizable group, a halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, and an alkyl group having 1 to 3 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. Also, any hydrogen in the alkyl group may be replaced with a halogen. Furthermore, any -CH3 in the alkyl group may be replaced with -CN.

[0066] R 3 With respect to elements other than hydrogen, these are the same as those described in formulas (1-1) and (2-1) as possible substituents of arylene and heteroarylene (i.e., those described as X).

[0067] Of these, R 3 The halogen is preferably a halogen, -CN, -NO2, -NCO, -NCS, -CF3, or -OCF3, more preferably fluorine, -CN, -NO2, or -CF3, and particularly preferably fluorine, -CN, or -NO2. In one embodiment, R 3 It is hydrogen. In one embodiment, R 3 It is fluorine. In one embodiment, R 3 is -CN. In one embodiment, R 3 It is -NO2.

[0068] X is hydrogen, a polymerizable group, a halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, or an alkyl group having 1 to 3 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. Also, any hydrogen in the alkyl group may be replaced with a halogen. Furthermore, any hydrogen in the alkyl group may be replaced with a halogen.

[0069] X is the same as the one written as X in equations (1-1) and (2-1).

[0070] Of these, X is preferably halogen, -CN, -NO2, -NCO, -NCS, -CF3, or -OCF3, more preferably fluorine, -CN, -NO2, or -CF3, and particularly preferably fluorine, -CN, or -NO2. In one embodiment, X is fluorine. In one embodiment, X is -CN. In one embodiment, X is -NO2.

[0071] Of the above, from the viewpoint of potentially improving dielectric properties, the compound represented by formula (1-3) is preferred.

[0072] The liquid crystal compound according to the present invention is more preferably a compound represented by the following formulas (1-5) to (2-6). [ka]

[0073] In the above formula, R 1 And X is the same as that described in equations (1-3) to (2-4) above.

[0074] R 4These are, independently, a polymerizable group, a halogen, -CN, -NO2, -NCO, -NCS, -CH2F, -CHF2, -CF3, -OCH2F, -OCHF2, -OCF3, and an alkyl group having 1 to 3 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. Also, any hydrogen in the alkyl group may be replaced with a halogen. Furthermore, any -CH3 in the alkyl group may be replaced with -CN.

[0075] R 4 This is the same as what is described in formulas (1-1) and (2-1) as possible substituents of arylene and heteroarylene (i.e., what is described as X).

[0076] Of these, R 4 The halogen is preferably a halogen, -CN, -NO2, -NCO, -NCS, -CF3, or -OCF3, more preferably fluorine, -CN, -NO2, or -CF3, and particularly preferably fluorine, -CN, or -NO2. In one embodiment, R 3 It is fluorine. In one embodiment, R 3 is -CN. In one embodiment, R 3 It is -NO2.

[0077] Of the above, from the viewpoint of potentially improving dielectric properties, the compound is preferably represented by formula (1-5) or formula (1-6). In one embodiment, the liquid crystal compound according to the present invention is preferably a compound represented by formula (1-5). Furthermore, in one embodiment, the liquid crystal compound according to the present invention is preferably a compound represented by formula (1-6).

[0078] In one embodiment, the liquid crystal compound according to the present invention is represented by any of the following formulas (1) to (13). [Chemistry]

[0079] Among these, the liquid crystal compound is more preferably a compound represented by the following formulas (1) to (4). [Chemistry]

[0080] The liquid crystal compound according to the present invention exhibits a ferroelectric nematic phase (N F phase), a nematic phase (N phase), a ferroelectric smectic phase (Sm F phase), and a smectic phase (Sm phase) according to a predetermined temperature, pressure, etc. At this time, the ferroelectric smectic phase (Sm F phase) can be a ferroelectric smectic A phase (SmA F phase) or a ferroelectric smectic C phase (SmC F phase). Also, the smectic phase (Sm phase) can be a smectic A phase (SmA phase) or a smectic C phase (SmC phase). In this specification, "ferroelectric" means exhibiting a hysteresis phenomenon in the relationship between an electric field and polarization. Specifically, it means exhibiting hysteresis in the electric flux density - electric field (D - E) curve obtained from the measurement of the polarization reversal current. At this time, the measurement of the polarization reversal current is performed by the method described in the examples.

[0081] In a preferred embodiment, the liquid crystal compound according to the present invention exhibits a ferroelectric nematic phase (N F phase). In a preferred embodiment, the liquid crystal compound according to the present invention exhibits a ferroelectric smectic phase (Sm F phase).

[0082] The relative permittivity of the liquid crystal compound according to the present invention is preferably 100 or more, more preferably 500 or more, even more preferably 1000 or more, and particularly preferably 10000 or more. In this specification, the relative permittivity of the liquid crystal compound refers to the dielectric constant of the ferroelectric nematic phase (N) of the liquid crystal compound. F This refers to the highest relative permittivity at the temperature at which the phase becomes the N-phase or nematic phase (N-phase). In this case, the relative permittivity is measured by the method described in the examples.

[0083] The dipole moment of the liquid crystal compound according to the present invention is preferably 12D or less, more preferably 10D or less, even more preferably 8.5D or less, particularly preferably 4 to 8.5D, and most preferably 4 to 7.5D, 4 to 7D, 5 to 7D, 6 to 7D, 7 to 8.5D, 7.2 to 8.5D, 7.5 to 8.5D, 7.2 to 8D, and 7.5 to 8D. Despite having a low dipole moment, the liquid crystal compound according to the present invention can exhibit high dielectric properties (for example, relative permittivity of 100 or more, 1000 or more, or 10000 or more). In this specification, the dipole moment of the liquid crystal compound is measured by the method described in the examples.

[0084] Since the liquid crystal compounds of the present invention do not contain a 1,3-dioxane ring, they can be manufactured without using expensive raw materials, making the synthesis of analogues easy. Furthermore, because no geometric isomers (cis and trans isomers) based on the 1,3-dioxane ring are formed, liquid crystal compounds can be manufactured in high yield, resulting in excellent cost-effectiveness.

[0085] 2. Liquid crystal composition According to one embodiment of the present invention, a liquid phase composition is provided. The liquid crystal composition includes the liquid crystal compound according to the present invention as described above. In this specification, "liquid crystal composition" includes two or more liquid crystal compounds. By mixing two or more liquid crystal compounds, it may be possible to widen the operating temperature range, optimize physical properties (optical properties, viscosity, dielectric properties, etc.), improve response speed, improve stability, and reduce manufacturing costs.

[0086] [Liquid crystal compound] The liquid crystal composition contains two or more liquid crystal compounds. In one embodiment, the liquid crystal composition contains two or more liquid crystal compounds according to the present invention as described above.

[0087] In one preferred embodiment, the liquid crystal composition can be used in combinations of the compound represented by formula (1) and the compound represented by formula (2), combinations of the compound represented by formula (1) and the compound represented by formula (3), combinations of the compound represented by formula (1) and the compound represented by formula (4), combinations of the compound represented by formula (2) and the compound represented by formula (3), combinations of the compound represented by formula (2) and the compound represented by formula (4), combinations of the compound represented by formula (1), the compound represented by formula (2), and the compound represented by formula (3), combinations of the compound represented by formula (1), the compound represented by formula (2), and the compound represented by formula (4), combinations of the compound represented by formula (1), the compound represented by formula (3), and the compound represented by formula (4), and combinations of the compound represented by formula (1), the compound represented by formula (2), the compound represented by formula (3), and the compound represented by formula (4).

[0088] The content of the liquid crystal compound according to the present invention is preferably 5 to 100% by mass, 10 to 100% by mass, 20 to 100% by mass, 30 to 100% by mass, or 40 to 100% by mass, and more preferably 50 to 100% by mass, based on the total mass of the liquid crystal composition. The liquid crystal composition may consist of two or more liquid crystal compounds according to the present invention (100% by mass). In one embodiment, the content of the liquid crystal compound according to the present invention is preferably 60 to 100% by mass, 70 to 100% by mass, or 80 to 100% by mass, more preferably 90 to 100% by mass, even more preferably 95 to 100% by mass, and most preferably 100% by mass, based on the total mass of the liquid crystal composition. High dielectric properties can be obtained by having the content of the liquid crystal compound according to the present invention within the above range. In one embodiment, the content of the liquid crystal compound according to the present invention is preferably 40 to 80% by mass, more preferably 40 to 75% by mass, 40 to 65% by mass, 50 to 75% by mass, 50 to 65% by mass, and even more preferably 40 to 65% by mass, based on the total mass of the liquid crystal composition. When the content of the liquid crystal compound according to the present invention is within the above range, it may be possible to widen the operating temperature range.

[0089] The liquid crystal composition may contain one or more of the liquid crystal compounds according to the present invention described above, together with other liquid crystal compounds.

[0090] The other liquid crystal compounds are liquid crystal compounds other than the liquid crystal compounds according to the present invention, and are preferably liquid crystal compounds having a relative permittivity of less than 1000. That is, in one embodiment, the liquid crystal composition contains one or more of the liquid crystal compounds according to the present invention and a liquid crystal compound having a relative permittivity of less than 1000. In one embodiment, the liquid crystal composition contains one liquid crystal compound according to the present invention and a liquid crystal compound having a relative permittivity of less than 1000. Also, in one embodiment, the liquid crystal compound contains two or more liquid crystal compounds according to the present invention and a liquid crystal compound having a relative permittivity of less than 1000.

[0091] The liquid crystal compound having a relative permittivity of less than 1000 is not particularly limited, and examples thereof include compounds represented by the following formula (5-1) or formula (6-1). Since the number of phenylene groups is one less than that in the above formula (1-2) or formula (2-2), the rigidity of the compound is relatively reduced, and thus the relative permittivity can be less than 1000.

Chemical formula

[0092] In the above formula, R 1 , R 2 , A 3 , X, and p are the same as those described in the above formula (1-2) or formula (2-2).

[0093] Liquid crystal compounds with a relative permittivity of less than 1000 are preferably represented by the following formulas (5-2) to (6-3). [ka]

[0094] In the above formula, R 1 , R 3 , and X are the same as those described in equations (1-3) to (2-4) above.

[0095] Specific examples of liquid crystal compounds with a relative permittivity of less than 1000 include compounds represented by the following formulas (A) to (F).

[0096] [ka]

[0097] The content of liquid crystal compounds with a relative permittivity of less than 1000 is preferably 60% by mass or less of the total mass of the liquid crystal composition. In one embodiment, the amount of the liquid crystal compound with a relative permittivity of less than 1000 is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, based on the total mass of the liquid crystal composition. High dielectric properties can be obtained by having a liquid crystal compound with a relative permittivity of less than 1000 in content of 20% by mass or less. In one embodiment, the liquid crystal compound with a relative permittivity of less than 1000 is preferably 20 to 60% by mass, more preferably 25 to 60%, 35 to 60%, 25 to 50%, or 35 to 50% by mass, based on the total mass of the liquid crystal composition. Having the liquid crystal compound with a relative permittivity of less than 1000 within this range can potentially broaden the operating temperature range.

[0098] 3. Elements According to one embodiment of the present invention, an element is provided. The element comprises the above-mentioned liquid crystal compound or liquid crystal composition.

[0099] The liquid crystal compound or liquid crystal composition according to the present invention can exhibit ferroelectricity and can therefore be used in various devices. Examples include liquid crystal displays (LCDs), capacitor non-volatile memory devices, and sensors. In this case, the type of liquid crystal display (LCD) is not particularly limited and may be any of the following: TN (Twisted Nematic), STN (Super Twisted Nematic), VA (Vertical Alignment), IPS (In-Plane Switching), OCB (Optically Compensated Bende), etc.

[0100] The element according to the present invention preferably includes a voltage application section. Because the voltage application section includes a liquid crystal compound that can exhibit ferroelectricity, the polarization direction of the liquid crystal compound can be changed by an external electric field. [Examples]

[0101] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0102] [Example 1] Synthesis of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl4-n-butyryloxy-2,6-difluorobenzoate (compound 1) [ka]

[0103] 5.74 g (44.1 mmol) of 3,5-difluorophenol (A-1) and 6.91 g (40.4 mmol) of benzyl bromide (A-2) were dissolved in 44 mL of anhydrous tetrahydrofuran (THF). 9.20 g (66.6 mmol) of potassium carbonate was added to this solution, and the reaction mixture was stirred overnight at 60°C. After cooling to room temperature, insoluble matter was removed by suction filtration, the filtrate was concentrated, and then dried. The resulting yellow liquid was dissolved in 100 mL of n-hexane and washed three times with 100 mL of distilled water. The organic layer was dried over anhydrous sodium sulfate, the solvent was removed, and the mixture was purified by silica gel column chromatography (eluent: n-hexane) to obtain benzyl 3,5-difluorophenyl ether (A-3) as a colorless liquid. Yield: 8.35 g (Yield: 94.8%).

[0104] 7.00 g (31.8 mmol) of benzyl 3,5-difluorophenyl ether (A-3) was dissolved in 50 mL of anhydrous THF, and the solution was cooled to -78°C under a nitrogen atmosphere using dry ice / acetone. At this temperature, 25 mL (40 mmol, 1.3 equivalents) of 1.6 M n-butyllithium in n-hexane solution was gradually added, and the mixture was stirred for 10 minutes. Then, 28 g (0.64 mol) of dry ice was added at -78°C, and the mixture was stirred for 10 minutes, followed by stirring at room temperature for 30 minutes. After stopping the reaction by adding 5 mL of distilled water, the solvent was removed. The residue was dissolved in 50 mL of distilled water, and 1 M hydrochloric acid was added to adjust the pH to 2-3. The resulting precipitate was collected by suction filtration, washed with distilled water, and dried under reduced pressure to obtain 4-benzyloxy-2,6-difluorobenzoic acid (A-4) as a white solid. Yield: 5.29 g (Yield: 62.9%).

[0105] 5.28 g (20.0 mmol) of 4-benzyloxy-2,6-difluorobenzoic acid (A-4), 244 mg (2.00 mmol) of 4-dimethylaminopyridine (DMAP), and 5.33 g (22.0 mmol) of 3-fluoro-4-(3,4,5-trifluorophenyl)phenol (A-5) were dissolved in 100 mL of dichloromethane (DCM). 4.39 g (22.9 mmol) of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (WSC) was added to this solution, and the reaction mixture was stirred overnight at room temperature. The resulting precipitate was collected by suction filtration and washed with DCM. After concentrating the filtrate, it was added to methanol, and the resulting precipitate was also collected. These solids were mixed, dried under reduced pressure, and 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-benzyloxy-2,6-difluorobenzoate (A-6) was obtained as a white solid. Yield: 7.44g (76.2%).

[0106] 7.33 g (15.0 mmol) of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-benzyloxy-2,6-difluorobenzoate (A-6) was dissolved in 60 mL of THF, and 367 mg of 5 wt% palladium-carbon (Pd / C) was added. The mixture was stirred overnight at room temperature under a hydrogen atmosphere. The solid was filtered off by suction filtration, and after concentrating the filtrate, the residue was reprecipitation with an acetone / n-hexane mixture. After drying under reduced pressure, 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-hydroxybenzoate (A-7) was obtained as a white solid. Yield: 5.57 g (Yield: 93.3%).

[0107] 796 mg (2.19 mmol) of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-hydroxybenzoate (A-7) and 222 mg (2.19 mmol) of triethylamine were added to 10 mL of anhydrous THF and dissolved. After cooling this solution to 0°C under an ice bath, 5 mL of anhydrous THF solution of 234 mg (2.20 mmol) of n-butyryl chloride (A-8) was gradually added. The reaction mixture was stirred at room temperature for one day, and the resulting precipitate was filtered off by suction filtration, and the filtrate was concentrated. The residue was dissolved in DCM and washed three times with ultrapure water. The organic layer was dried over anhydrous sodium sulfate, the solvent was removed, and the resulting solid was purified by silica gel column chromatography (eluent: n-hexane / DCM = 1:1 (volume ratio)). Further recrystallization was performed in a mixed solvent of n-hexane / DCM to obtain 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-n-butyryloxy-2,6-difluorobenzoate (compound 1) as a white solid. Yield: 804 mg (yield: 85.8%). 1 H NMR(400MHz,CDCl3,ppm): δ 7.46-7.42(m, 1H,phenyl), 7.20-7.15(m, 4H, phenyl), 6.90 (d, 2H, J = 8.8 Hz, phenyl), 2.58 (t, 2H, J = 7.2 Hz, -CH2-C=O), 1.80 (sext, 2H, J = 7.4 Hz, CH3-CH2-), 1.06 (t, 3H, J = 7.2 Hz, CH3-). HRMS(FAB+)m / z:calcd for C 23 H 14 F6O4:468.0796;found:469.0875(M+H).

[0108] According to the above manufacturing method, it was possible to manufacture the product using inexpensive raw materials. Furthermore, excluding the protection and deprotection steps of the phenolic hydroxyl group, the target liquid crystal compound could be manufactured in just three steps. Moreover, since it does not contain a 1,3-dioxane ring, no geometric isomers (cis and trans isomers) are formed, so the separation and purification steps were not required, and as a result, the target liquid crystal compound could be manufactured in high yield.

[0109] [ka]

[0110] [Example 2] Synthesis of 4-(4-cyano-3,5-difluorophenyl)-3-fluorophenyl4-n-butyryloxy-2,6-difluorobenzoate (compound 2) [ka]

[0111] 2.86 g (22.0 mmol) of 3,5-difluorophenol (A-1) and 2.20 g (21.7 mmol) of triethylamine were dissolved in 20 mL of DCM. 3.00 g (19.9 mmol) of tert-butyldimethylsilyl chloride was gradually added to this solution at 0°C, and the reaction mixture was stirred at room temperature for 2 days. The resulting precipitate was filtered off by suction filtration, and the filtrate (DCM solution) was separated three times with distilled water. The organic layer was dried over anhydrous sodium sulfate, the solvent was removed, and tert-butyldimethylsilyl 3,5-difluorophenyl ether (A-9) was obtained as a pale yellow liquid by vacuum drying. Yield: 4.87 g (>99%).

[0112] 9.54 g (39.0 mmol) of tert-butyldimethylsilyl 3,5-difluorophenyl ether (A-9) was dissolved in 30 mL of anhydrous THF and cooled to -78°C in dry ice-acetone under a nitrogen atmosphere. At this temperature, 30 mL (48 mmol, 1.2 equivalents) of a 1.6 M n-butyllithium solution in n-hexane was gradually added dropwise, and the mixture was stirred for 10 minutes. Then, 3.14 g (43.0 mmol) of anhydrous N,N-dimethylformamide (DMF) was added, and the mixture was stirred at -78°C for 10 minutes. After returning to room temperature, the reaction was stopped by adding distilled water, the organic solvent was removed, and the residue was added to distilled water. The pH of this aqueous solution was adjusted to approximately 4 with 1 M hydrochloric acid, and the resulting precipitate was collected by suction filtration. After drying under reduced pressure, the precipitate was washed with DCM to obtain 2,6-difluoro-4-hydroxybenzaldehyde (A-10) as a white solid. Yield: 4.21g (68.2%).

[0113] 20 mL of a DCM solution containing 1.02 g (6.45 mmol) of 2,6-difluoro-4-hydroxybenzaldehyde (A-10) and 715 mg (7.07 mmol) of triethylamine was cooled to 0°C in an ice bath. 3 mL of a DCM solution containing 750 mg (7.04 mmol) of n-butyryl chloride (A-8) was gradually added dropwise. The reaction mixture was stirred at room temperature for 2 days, after which DCM was added. The mixture was then separated and washed with aqueous sodium bicarbonate solution and then distilled water. The organic layer was dried over anhydrous sodium sulfate, concentrated, and the resulting residue was purified by silica gel column chromatography (eluent: n-hexane / DCM = 1:1 (volume ratio)) to obtain 4-n-butyryloxy-2,6-difluorobenzaldehyde (A-11) as a colorless solution. Yield: 1.43 g (Yield: 94.3%).

[0114] To 2.0 mL of a dimethyl sulfoxide (DMSO) solution containing 1.34 g (5.87 mmol) of 4-n-butyryloxy-2,6-difluorobenzaldehyde (A-11), 2.10 g (29.9 mmol) of 2-methyl-2-butene was added, followed by 5.0 mL of an aqueous solution of 2.17 g (24.0 mmol) of sodium dihydrogen phosphate. This mixture was cooled in an ice bath, and 4.0 mL of an aqueous solution of 2.17 g (24.0 mmol) of sodium chlorite was added. The reaction mixture was stirred at 0°C for 2 hours. After stirring for another 2 hours at room temperature, 1 M hydrochloric acid was added to adjust the pH to approximately 3. The resulting precipitate was collected by suction filtration, washed with distilled water, and dried under reduced pressure to obtain 4-n-butyryloxy-2,6-difluorobenzoic acid (A-12) as a white solid. Yield: 1.01 g (Yield: 70.1%).

[0115] 977 mg (4.00 mmol) of 4-n-butyryloxy-2,6-difluorobenzoic acid (A-12) and 1.20 g (4.82 mmol) of 4-(4-cyano-3,5-difluorophenyl)-3-fluorophenol (A-13) were added to 30 mL of DCM. 1.05 g (5.48 mmol) of WSC was gradually added to this mixture, and the reaction mixture was stirred at room temperature for 2.5 hours. Then, 50 mL of DCM was added, and the mixture was separated and washed three times with 50 mL of ultrapure water. The organic layer was dried over anhydrous sodium sulfate, the solvent was removed, and the residue was purified by silica gel column chromatography (n-hexane / DCM = 1:2 (volume ratio)). Subsequently, recrystallization was performed with an n-hexane / DCM mixture to obtain 4-(4-cyano-3,5-difluorophenyl)-3-fluorophenyl 4-n-butyryloxy-2,6-difluorobenzoate (compound 2) as a white solid. Yield: 638 mg (33.6%). 1H NMR(400MHz,CDCl3,ppm): δ 7.52-7.48(m, 1H, phenyl), 7.28-7.21(m, 4H, phenyl), 6.91 (d, 2H, J = 9.2 Hz, phenyl), 2.59 (t, 2H, J = 7.4 Hz, -CH2-COO-), 1.84-1.75 (m, 2H, CH3-CH2-), 1.06 (t, 3H, J = 7.4 Hz, CH3-). HRMS(FAB+)m / z:calcd for C 24 H 14 F5NO4:475.0843;found:476.0923(M+H).

[0116] [ka]

[0117] [Example 3] Synthesis of 4-(3,5-difluoro-4-nitrophenyl)-3-fluorophenyl4-n-butyryloxy-2,6-difluorobenzoate (compound 3) [ka]

[0118] 900 mg (3.69 mmol) of 4-n-butyryloxy-2,6-difluorobenzoic acid (A-12) and 1.15 g (4.27 mmol) of 4-(3,5-difluoro-4-nitrophenyl)-3-fluorophenol (A-14) were added to 10 mL of DCM. 860 mg (4.49 mmol) of WSC was gradually added to this mixture, and the reaction mixture was stirred at room temperature for 2 hours. Then, 100 mL of DCM was added, and the mixture was separated and washed three times with 100 mL of ultrapure water. The organic layer was dried over anhydrous sodium sulfate, the solvent was removed, and the resulting crude product was purified by silica gel column chromatography (eluent: n-hexane / DCM = 1:1 (volume ratio)). Recrystallization was then performed in an n-hexane / DCM mixed solvent to obtain 4-(3,5-difluoro-4-nitrophenyl)-3-fluorophenyl 4-n-butyryloxy-2,6-difluorobenzoate (compound 3) as a white solid. Yield: 724 mg (Yield: 40.0%). 1 H NMR(400MHz,DMSO-d6,ppm): δ 7.84-7.79(m, 3H, phenyl), 7.55(dd, 1H, J = 12.0, 2.0 Hz, phenyl), 7.38-7.34(m, 3H, phenyl), 2.62 (t, 2H, J = 7.0 Hz, -CH2-COO-), 1.72-1.63 (m, 2H, CH3-CH2-), 0.99 (t, 3H, J = 7.6 Hz, CH3-). HRMS(FAB+)m / z:calcd for C 23 H 14 F5NO6:495.0741;found:496.0821(M+H).

[0119] [ka]

[0120] [Example 4] Synthesis of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-n-butyryloxybenzoate (compound 4) [ka]

[0121] 4.56 g (20.0 mmol) of 4-benzyloxybenzoic acid (A-15), 5.33 g (22.0 mmol) of 3-fluoro-4-(3,4,5-trifluorophenyl)phenol (A-5), and 2.44 g (20.0 mmol) of DMAP were dissolved in 100 mL of DCM. 4.50 g (23.5 mmol) of WSC was added to this solution, and the reaction mixture was stirred overnight at room temperature. The resulting precipitate was collected by suction filtration, washed with DCM, and the target product was obtained. Separately, the filtrate was separated and washed with dilute hydrochloric acid, then with distilled water, and the organic layer was dried over anhydrous sodium sulfate to remove the solvent. The residue was then washed with methanol to obtain 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-benzyloxybenzoate (A-16). Yield: 8.69 g (Yield: 96.0%).

[0122] 8.69 g (19.2 mmol) of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-benzyloxybenzoate (A-16) was added to 100 mL of THF solution, and 900 mg of 5 wt% Pd / C (10 wt% relative to the substrate) was added. The mixture was stirred at room temperature under a hydrogen atmosphere for 2 days. After filtering off the solid, the filtrate was concentrated and reprecipitation was performed with an acetone / n-hexane mixed solvent to obtain 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-hydroxybenzoate (A-17) as a white solid. Yield: 6.33 g (Yield: 90.9%).

[0123] 1.09 g (3.00 mmol) of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-hydroxybenzoate (A-17) and 334 mg (3.30 mmol) of triethylamine were added to 30 mL of DCM and cooled to 0°C under an ice bath. 330 mg (3.30 mmol) of n-butyryl chloride (A-8) was gradually added dropwise, and the reaction mixture was stirred at room temperature for 1 hour. The precipitate was filtered off, and 50 mL of the filtrate was washed twice with 50 mL of distilled water, and then with 50 mL of ultrapure water. After drying over anhydrous sodium sulfate, the solvent was removed, and 1.53 g of the resulting crude product was purified by silica gel column chromatography (eluent: n-hexane / DCM = 1:1 → 1:2 (volume ratio)). Subsequently, recrystallization was performed in a mixed solvent of n-hexane / DCM to obtain 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-n-butyryloxybenzoate (compound 4) as a white solid. Yield: 1.15 g (Yield: 85.8%). 1 H NMR(400MHz,CDCl3,ppm): δ 8.24(d, 2H, J = 8.8 Hz, phenyl), 7.46-7.41(m, 1H, phenyl), 7.28-7.26(m, 2H, phenyl), 7.19(t, 2H, J = 7.2 Hz, phenyl ),7.14-7.10(m, 2H, phenyl )2.60 (t, 2H, J = 7.2 Hz, -CH2-C=O), 1.86-1.77 (m, 2H, CH3-CH2-), 1.07 (t, 3H, J = 7.4 Hz, CH3-). HRMS(FAB+)m / z:calcd for C 23 H 16 F4O4:432.0985;found:433.1064(M+H).

[0124] [ka]

[0125] [Example 5] Synthesis of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl4-acetyloxy-2,6-difluorobenzoate (compound 5) [ka]

[0126] 3-Fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-acetyloxy-2,6-difluorobenzoate (compound 5) was synthesized in the same manner as in Example 1, except that 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-hydroxybenzoate (A-7) was reacted with acetyl chloride instead of n-butyryl chloride (A-8).

[0127] [ka]

[0128] [Example 6] Synthesis of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-propionyloxybenzoate (compound 6) [ka]

[0129] 3-Fluoro-4-(3,4,5-trifluorophenyl)phenyl2,6-difluoro-4-propionyloxybenzoate (compound 6) was synthesized in the same manner as in Example 1, except that 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl2,6-difluoro-4-propionyloxybenzoate (compound 6) was reacted with propionyl chloride instead of n-butyryl chloride (A-8) in 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl2,6-difluoro-4-propionyloxybenzoate (compound 6).

[0130] [ka]

[0131] [Example 7] Synthesis of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-valeryloxybenzoate (compound 7) [ka]

[0132] 3-Fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-valeryloxybenzoate (compound 7) was synthesized in the same manner as in Example 1, except that 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-valeryloxybenzoate (compound 7) was reacted with valeryl chloride instead of n-butyryl chloride (A-8).

[0133] [ka]

[0134] [Example 8] Synthesis of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-isovaleryloxybenzoate (compound 8) [ka]

[0135] 3-Fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-isovaleryloxybenzoate (compound 8) was synthesized in the same manner as in Example 1, except that 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-isovaleryloxybenzoate (compound 8) was reacted with isovaleryl chloride instead of n-butyryl chloride (A-8).

[0136] [ka]

[0137] [Example 9] Synthesis of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-(DL-2-methylbutyryloxy)benzoate (compound 9) [ka]

[0138] 3-Fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-(DL-2-methylbutyryloxy)benzoate (compound 9) was synthesized in the same manner as in Example 1, except that 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-(DL-2-methylbutyryloxy)benzoate (compound 9) was reacted with DL-2-methylbutyryl chloride instead of n-butyryl chloride (A-8) in the reaction of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-(DL-2-methylbutyryloxy)benzoate (compound 9).

[0139] [ka]

[0140] [Example 10] Synthesis of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl4-crotonoyloxy-2,6-difluorobenzoate (compound 10) [ka]

[0141] 3-Fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-crotonoyloxy-2,6-difluorobenzoate (compound 10) was synthesized in the same manner as in Example 1, except that 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-hydroxybenzoate (A-7) was reacted with crotonic acid instead of n-butyryl chloride (A-8).

[0142] [ka]

[0143] [Example 11] Synthesis of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-(trans-3-pentenoyloxy)benzoate (compound 11) [ka]

[0144] 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-(trans-3-pentenoyloxy)benzoate (compound 11) was synthesized in the same manner as in Example 1, except that 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-(trans-3-pentenoyloxy)benzoate (compound 11) was reacted with trans-3-pentenoic acid instead of n-butyryl chloride (A-8) using the same method as in Example 1.

[0145] [ka]

[0146] [Example 12] Synthesis of 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-propionyl oxybenzoate (compound 12) [ka]

[0147] 3-Fluoro-4-(3,4,5-trifluorophenyl)phenyl4-propionyloxybenzoate (compound 12) was synthesized in the same manner as in Example 4, except that 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl4-hydroxybenzoate (A-17) was reacted with propionyl chloride instead of n-butyryl chloride (A-8).

[0148] [ka]

[0149] [Example 13] Synthesis of 3-Fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-valeryloxybenzoate (Compound 13) [Chemical Formula]

[0150] 3-Fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-valeryloxybenzoate (Compound 13) was synthesized in the same manner as in Example 4, except that 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 4-hydroxybenzoate (A-17) was reacted with valeryl chloride instead of n-butyryl chloride (A-8).

[0151] [Chemical Formula]

[0152] [Comparative Examples 1-4] The following compounds were used as Comparative Examples 1-4. [Chemical Formula]

[0153] [Evaluation] Various evaluations were performed on the liquid crystal compounds of Examples 1-4 and Comparative Examples 1-4.

[0154] (Measurement of Phase Transition Temperature) Differential scanning calorimetry (DSC) was measured using a measurement device DSC 1 STARe system (manufactured by METTLER TOLEDO) under the condition of 5°C / min. Specifically, exothermic peaks and endothermic peaks were measured in the order of primary heating, primary cooling, secondary heating, and secondary cooling.

[0155] <000​​Note that the phase transition from the crystalline phase to phase A is based on the endothermic peak data during the initial heating, while the phase transitions to other phases are based on the exothermic peak data during the second cooling. Phase transitions below the melting point are monotropic phase transitions that occur in a supercooled state during cooling, while all others are enantiotropic phase transitions.

[0156] [Table 1]

[0157] (Identification of each phase) By performing polarized light microscopy (POM) observation, small-angle X-ray scattering (SAXS) measurements, and polarization reversal current measurements, the A to E phases observed in Examples 1 to 4 and Comparative Examples 1 to 4 were identified.

[0158] (1) Preparation of the measuring cell Bare glass cells, unoriented treated cells, and vertically oriented (homeotropic orientation) treated cells were prepared.

[0159] The non-oriented cell was prepared by injecting a liquid crystal compound into a plain glass cell (manufactured by EHC Corporation) (area 1 m²). 2 Cell thickness: 10 μm). The vertically aligned (homeotropically aligned) cells were fabricated as follows: A glass substrate with indium tin oxide (ITO) electrodes was ultrasonically cleaned in Shikaclean, distilled water, and acetone, followed by ozone cleaning. As a surface modifier, a cyclopentane solution of octadecyltrimethoxysilane (concentration: 2 vol%) was spin-coated at 3000 rpm for 30 seconds. After firing at 130°C for 10 minutes, it was ultrasonically cleaned in cyclopentanone, and then in ethanol. Subsequently, after vacuum firing at 130°C for 3 hours, a sandwich cell was assembled using a 10 μm thick PET film. The vertically aligned (homeotropically aligned) cells were fabricated by injecting a liquid crystal compound into the sandwich cell.

[0160] (2) Polarized light microscopy (POM) observation The ECLIPSE LV100NPO L-WinP (manufactured by Nikon Corporation), which is a polarizing microscope, and the DS-Ri2 camera (manufactured by Nikon Corporation), which is a microscope digital camera, were used. For the measurement cell, an unoriented treatment cell and a vertical alignment (homeotropic alignment) treatment cell were used. The measurement cell was placed on a temperature-controlled stage, which was then placed on the stage of the polarizing microscope. Temperature control was performed at a rate of 5 °C / min for heating and cooling, and observations were made under crossed nicols.

[0161] In the liquid crystal compound of Example 1, when the A phase was observed by POM, a striped texture characteristic of the ferroelectric nematic phase (N F phase) was observed. Therefore, the A phase was identified as the ferroelectric nematic phase (N F phase). Also, as a result of POM observation, the B phase was identified as the nematic phase (N phase), and the C phase was identified as the isotropic phase (Iso phase).

[0162] In the liquid crystal compounds of Example 2 and Example 3, when the A phase was observed by POM, a striped texture characteristic of the ferroelectric nematic phase (N F phase) was observed. Therefore, the A phase was identified as the ferroelectric nematic phase (N F phase). Also, as a result of POM observation, the C phase was identified as the nematic phase (N phase), and the D phase was identified as the isotropic phase (Iso phase). Regarding the B phase between the A phase (N F phase) and the C phase (N phase), since both the sandy texture observed in the C phase (N phase) and the striped texture observed in the A phase (N F phase) were observed, it was identified as an unidentified nematic phase (N X phase).

[0163] In the liquid crystal compound of Example 4, when the A phase was observed by POM, a mosaic texture characteristic of the ferroelectric smectic phase (Sm F phase) was observed. Therefore, the A phase was identified as the ferroelectric smectic phase (Sm FIt was identified as a phase. Furthermore, POM observations identified phase B as the nematic phase (N phase) and phase C as the isotropic phase (Iso phase).

[0164] Figure 1 shows POM images of the A phase of the liquid crystal compounds of Examples 1 to 4, measured using an unoriented cell. Figure 1A shows the ferroelectric nematic phase (N) of the liquid crystal compound of Example 1. F Figure 1B shows the ferroelectric nematic phase (N) of the liquid crystal compound of Example 2. F Figure 1C shows the ferroelectric nematic phase (N) of the liquid crystal compound of Example 3. F Figure 1D shows the ferroelectric smectic phase (Sm) of the liquid crystal compound of Example 4. F (Agreement)

[0165] (3) Small-angle X-ray scattering (SAXS) measurement Ferroelectric smectic phase (Sm F The A phase of the liquid crystal compound in Example 4, which was identified as the A phase, was further structurally analyzed by small-angle X-ray scattering measurement. Specifically, small-angle X-ray scattering (SAXS) measurements were performed using the Kyushu University beamline (BL06) located at the Saga Prefectural Kyushu Synchrotron Light Research Center (SAGA-LS). A crystalline compound was injected into a hall stage (diameter: 3 mm, depth: 1 mm) equipped with a pair of magnets (magnetic field: approximately 560 mT), and the stage was positioned so that the direction of the magnetic field (direction of the liquid crystal compound) and the direction of X-ray irradiation were perpendicular. Measurements were performed under cooling operation at 90-145°C with an aging time of 1 minute and an exposure time of 10 seconds, and a one-dimensional profile was obtained by integrating the resulting SAXS images.

[0166] The measurement results showed strong primary scattering observed in the smectic A phase, therefore the A phase of the liquid crystal compound in Example 4, i.e., the ferroelectric smectic phase (Sm F The phase is the ferroelectric smectic A phase (SmA). F It was identified as being in the phase.

[0167] (4) Measurement of polarization reversal current An apparatus equipped with a 2411B arbitrary waveform generator (manufactured by Toyo Technica Co., Ltd.), a Wave Book / 516A analog-to-digital converter (manufactured by Toyo Technica Co., Ltd.), and a model 6254C current-voltage / charge-voltage (I-V / Q-V) converter (manufactured by Toyo Technica Co., Ltd.) was used. In addition, a vertically aligned (homeotropic alignment) processing cell was used as the measurement cell.

[0168] The polarization reversal current was measured by the triangular wave method at an applied voltage of 20 Vpp (±10 V) and a frequency of 10 to 200 Hz, and the measured current was integrated to obtain the electric flux density-electric field (D-E) curve.

[0169] Figure 2 shows the D-E curves of the liquid crystal compounds of Examples 1 to 4. Figure 2A is the D-E curve (frequency: 100 Hz) of the liquid crystal compound of Example 1, Figure 2B is the D-E curve (frequency: 200 Hz) of the liquid crystal compound of Example 2, Figure 2C is the D-E curve (frequency: 100 Hz) of the liquid crystal compound of Example 3, and Figure 2D is the D-E curve (frequency: 10 Hz) of the liquid crystal compound of Example 4.

[0170] The liquid crystal compound of Example 1 showed hysteresis in the D-E curve at 95 to 100 °C showing the A phase. The liquid crystal compound of Example 2 showed hysteresis in the D-E curve at 80 to 100 °C showing the A phase. The liquid crystal compound of Example 3 showed hysteresis in the D-E curve at 60 to 100 °C showing the A phase. The liquid crystal compound of Example 4 showed hysteresis in the D-E curve at 90 to 120 °C showing the A phase. Therefore, it was confirmed that all of the A phases of Examples 1 to 4 have ferroelectricity.

[0171] (5) Results The A to F phases specified from the results of (2) to (4) above are as shown in Table 2 below. In Table 2, "N F phase" is a ferroelectric nematic phase, "N phase" is a nematic phase, "N x phase" is NF A phase that can occur on the high temperature side of the [phase name] and the low temperature side of the N phase, and N F It is an unexplained nematic phase different from the [phase name] phase and the N phase. "N F ' phase" is N F It is a ferroelectric nematic phase that can occur on the low temperature side of the phase. It is an unexplained ferroelectric nematic phase different from the N F phase. "SmA F phase" is the ferroelectric nematic A phase. "SmA F ' phase" is SmA F It is a ferroelectric smectic A phase that can occur on the low temperature side of the SmA phase. It is an unexplained ferroelectric smectic A phase different from the SmA F phase. "Iso phase" is the isotropic phase.

[0172] [Table 2]

[0173] From the results of Table 1, it was found that the liquid crystal compounds of Examples 1 to 4 can form a [phase name] phase, an N F phase or a SmA F phase, an N phase, and an Iso phase, and furthermore, they can form an N X phase to a certain extent. That is, it was found that the liquid crystal compounds of Examples 1 to 4 have a simpler phase transition behavior compared to the liquid crystal compounds of Comparative Examples 1 to 4. In addition, it was found that the liquid crystal compounds of Examples 1 to 4 have a lower phase transition temperature compared to the liquid crystal compounds of Comparative Examples 1 to 4. For example, in the liquid crystal compounds of Examples 1 to 4, since there is no 1,3-dioxane ring that the liquid crystal compounds of Comparative Examples 1 to 4 have, it is considered that the phase transition was simplified and the phase transition temperature was lowered by reducing the intermolecular interaction.

[0174] (Dipolar moment) The dipole moments of the liquid crystal compounds of Examples 1 to 4 and Comparative Examples 1 to 4 were calculated from the most stable structures obtained by quantum chemical calculations (density functional theory, B3LYP / 6-31+G(2d, p)) using Gaussian1'six'. The obtained results are shown in Table 3 below.

[0175] [Table 3]

[0176] The results in Table 3 show that Examples 1-4 had lower dipole moments compared to the corresponding Comparative Examples 1-4. Conventionally, it was thought that a larger dipole moment in a liquid crystal compound was advantageous for the development of ferroelectricity. However, despite having low dipole moments, Examples 1-4 exhibited excellent dielectric properties, as will be described later. Therefore, the results for Examples 1-4 are surprising as they contradict conventional knowledge.

[0177] (Dielectric properties) The dielectric properties of the liquid crystal compounds in Examples 1 to 4 were evaluated by measuring their dielectric relaxation spectra. Dielectric relaxation spectrum measurements were performed as follows. Measurements were taken using an impedance / gain phase analyzer, the SI1260 (manufactured by Solatron Metrology), with an applied voltage of 0.1 Vrms. Furthermore, the vertically oriented (homeotropically oriented) cells prepared in the "Identification of Each Phase" section above were used as samples. First, the resistance and capacitance of the indium tin oxide (ITO) electrode were measured using an empty cell, and the dielectric constant was determined by using the obtained values ​​to correct the impedance of the sample.

[0178] The results obtained are shown in Tables 4-1 and 4-2 below. Table 4-1 shows the results measured at a frequency of 100 Hz, and Table 4-2 shows the results measured at a frequency of 1000 Hz. Figure 3 is a logarithmic graph showing the relationship between relative permittivity and temperature at a frequency of 1000 Hz for the liquid crystal compounds of Examples 1 to 4.

[0179] [Table 4-1] [Table 4-2]

[0180] From the results in Tables 4-1 and 4-2, and Figure 3, it was found that the liquid crystal compounds of Examples 1 to 4 had a relative permittivity of at least 100 and exhibited excellent dielectric properties. The compounds in Examples 1-3 exhibited extremely high dielectric constants of 10,000 or more. Furthermore, the compounds of Examples 2 and 3 exhibited high dielectric constants over a wide temperature range.

[0181] [Examples 14-19: Liquid Crystal Compositions] A liquid crystal composition was produced by mixing the liquid crystal compounds of Examples 2 and 3 and compound A, in which the relative permittivity of the nematic phase is less than 1000, as shown in Table 5, heating, and then cooling. Table 5 also lists Examples 2 and 3, as well as Comparative Example 5, in which Compound A was used alone.

[0182] [Table 5]

[0183] The structure of compound A is as follows: [ka]

[0184] [evaluation] The liquid crystal compositions of Examples 14-19 and the liquid crystal compound of Comparative Example 5 were subjected to differential scanning calorimetry (DSC), polarizing microscope (POM) observation, polarization reversal current measurement, and dielectric relaxation spectrum measurement using the same methods as in Examples 1-4. The results are shown in Table 6 below. Figure 4 shows the change in phase transition temperature of the liquid crystal compositions of Examples 14 to 19. Figure 4A shows the data for Examples 2, 14 to 16, and 3 (horizontal axis: liquid crystal compound content of Example 3, vertical axis: phase transition temperature), and Figure 4B shows the data for Examples 15, 17 to 19, and Comparative Example 5 (horizontal axis: liquid crystal compound content of compound A, vertical axis: phase transition temperature).

[0185] Note that all phase transition data is from the second cooling. Phase transitions below the melting point are monotropic phase transitions that occur in a supercooled state during cooling, while all others are enantiotropic phase transitions. [Table 6]

[0186] From the results in Table 6 and Figure 4, in the liquid crystal compositions of Examples 14-16, which were obtained by mixing the liquid crystal compounds of Examples 2 and 3, N F The temperature at which the phase transition from the phase to the crystalline phase occurs is 40-43°C, which is lower than when the liquid crystal compounds of Example 2 or 3 are used individually (53°C or 60°C). In other words, by mixing the liquid crystal compounds of Example 2 and 3, N F We were able to broaden the temperature range in which the phase manifests.

[0187] Furthermore, in Examples 17-19, where compound A was further mixed with Example 15 (an equimolar mixture of the liquid crystal compounds from Examples 2 and 3), N F It was found that the temperature at which the phase transition from one phase to the crystalline phase occurs is 24-30°C, and can even decrease further.

Claims

1. Formulas (1-5) to (2-6) below: 【Chemistry 1】 (In the above formula, R1 is hydrogen, a polymerizable group, and an alkyl group having 1 to 20 carbon atoms. In this case, any -CH2- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-, and any hydrogen in the alkyl group may be replaced with a halogen. R4 is independently halogen, -CN, -NO2, -NCO, -NCS, -CF3, and -OCF3. X is hydrogen, a polymerizable group, a halogen, -CN, -NO₂, -NCO, -NCS, -CH₂F, -CHF₂, -CF₃, -OCH₂F, -OCHF₂, -OCF₃, or an alkyl group having 1 to 3 carbon atoms. In this case, any -CH₂- in the alkyl group may be replaced with -O-, -S-, -COO-, -OCO-, -CH=CH-, -CF=CF-, or -C≡C-. Any hydrogen in the alkyl group may be replaced with a halogen, and any -CH₃ in the alkyl group may be replaced with -CN. A liquid crystal compound represented by [the formula shown].

2. The liquid crystal compound according to claim 1, wherein X is halogen, -CN, -NO2, -NCO, -NCS, -CF3, -OCF3.

3. The compound according to claim 1, wherein X is a halogen, -CN, and -NO2.

4. The liquid crystal compound according to claim 1, wherein R4 is a halogen.

5. Equations (1) to (13) below: 【Chemistry 2】 The liquid crystal compound according to claim 1, as represented by [the formula].

6. The liquid crystal compound according to claim 1, wherein the relative permittivity is 1000 or more.

7. The liquid crystal compound according to claim 1, wherein the dipole moment is 8.5D or less.

8. A liquid crystal composition comprising the liquid crystal compound described in claim 1.

9. A liquid crystal composition comprising two or more liquid crystal compounds as described in claim 1.

10. The liquid crystal composition according to claim 8, further comprising a liquid crystal compound having a relative permittivity of less than 1000.

11. The liquid crystal composition according to claim 9, further comprising a liquid crystal compound having a relative permittivity of less than 1000.

12. A device comprising a liquid crystal compound according to any one of claims 1 to 7 or a liquid crystal composition according to any one of claims 8 to 11.

13. The element according to claim 12, further comprising a voltage application section.

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