JPH0196153A - Optically active pentanediol derivative - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I [R1 is 1-16C alkyl, alkoxy, alkanoyloxy, alkoxycarbonyl or alkoxycarbonyloxy; R2 is 1-10C alkyl; X is formula II or III or single bond; m and n are 1 or 2; C* and C** each are asymmetric carbon atoms respectively having independent absolute configura tion of (R) or (S)]. EXAMPLE:4'-{( 1R,3R )-1-methyl-3-ethoxybutyloxycarbonyl} phenyl 4-dodecyloxy benzoate. USE:Useful as an electrooptical display material, used especially as a liquid crystal material having ferroelectricity and especially useful as liquid crystal display elements having responsiveness and memory properties, readily produci ble and having great chemical stability. PREPARATION:A compound expressed by formula IV is reacted with an alkyl halide expressed by formula V to provide a product, which is subsequently reacted with a compound expressed by formula VI and then benzylamine, etc., to afford the aimed compound expressed by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel optically active bentanediol derivative useful as an electro-optical display material, and particularly to a liquid crystal material having ferroelectricity. Furthermore, the present invention provides a liquid crystal material that can be used for liquid crystal display elements and has particularly excellent responsiveness and memory performance compared to conventional liquid crystal materials.

[Prior art]

Liquid crystal display elements have many excellent properties, such as low voltage operation, low power consumption, the ability to display thinly, and because they are light-receiving, they can be used in bright places and do not cause eye strain. Therefore, they are now widely used as various display elements. Currently, Twi
The most common type is called the ated nematic (TN) type.

This TN type display system uses nematic liquid crystal, but while it has the excellent features mentioned above, its response is very slow compared to other light emitting display systems such as CRT. There were drawbacks. Furthermore, when the applied electric field was cut off, the display returned to its original state, so no memorization of the display (memory effect) was obtained. For these reasons, it is not suitable for application to moving picture screens in optical shutters, printer heads, televisions, etc., which require high-speed response and time-division operation, due to various restrictions.

In addition to the TN type, liquid crystal display elements include the dust-host (GH) type, controlled birefringence (ECB) type, and phase change type (p
c) type, thermal effect type, etc. have been researched and developed, and each has its own characteristics, but in terms of responsiveness, all of them are better than T.
It could not be said that there was any particular improvement compared to the N type. In response to these problems, a liquid crystal display system called a dual-frequency drive type was developed as a liquid crystal display system capable of obtaining high-speed response, and although a slight improvement was made in response, it is still not fully satisfactory. Moreover, it also had drawbacks such as the fact that its operating circuit was too complex.

For this reason, attempts have been made to develop new liquid crystal display systems with even better responsiveness.

In line with this objective, ferroelectric liquid crystals have recently been announced. (R, May@r @t al: J, Ph
ysiqe36 L69 (1975)) It has been pointed out that display elements using this ferroelectric liquid crystal have a high-speed response of 100 to 1000 times compared to conventional liquid crystal displays and a memory effect brought about by bistability. (
1jLA, C1ark, S, Ta Lagerwa
ll :Appl Phya Lstt :36899
(1980)) It can be expected to be applied to display elements on the moving picture screen of televisions, high-speed optical shutter printer heads, and other surfaces such as computer terminals.

The liquid crystal phase of ferroelectric liquid crystals belongs to the tilted chiral smectic phase, and among these, the one that is practically desirable is the chiral smectic C (hereinafter abbreviated as SC*) phase, which has the lowest viscosity. It is called.

Liquid crystal compounds exhibiting the SC* phase have been studied and many compounds have already been synthesized. However, these SC* compounds alone cannot be used as ferroelectric liquid crystal display elements under the following conditions: (a) exhibiting ferroelectricity in a wide temperature range including room temperature; and (b) having an appropriate tilt angle. There is no known material that simultaneously satisfies the following: ←→ has large spontaneous polarization; and (=l small viscosity; In order to satisfy these conditions, it is necessary to use an "sc" liquid crystal composition.

There are two ways to obtain the SC* composition, one is the S
This is a method of mixing a plurality of compounds exhibiting a C* phase, and another method is a method of adding a chiral liquid crystal compound to a liquid crystal compound or composition exhibiting a non-chiral smectic C (hereinafter abbreviated as SC) phase. It is.

With the former method, it is easy to obtain a wide temperature range and large spontaneous polarization. However, the compound having the SC* phase has an asymmetric carbon in the molecule, particularly in the side chain, and has a branched group. Because of these branched groups, the viscosity of the liquid crystal is high, and even if the spontaneous polarization of the liquid crystal is increased, it is difficult to obtain a high-speed response.

In the latter method, although it depends on the amount of the chiral liquid crystal compound added, it is difficult to obtain an SC'' composition with a large spontaneous polarization because the base SC liquid crystal does not have spontaneous polarization. However, since the liquid crystal compound in the parent 5CIA composition does not require the presence of a branched group, its viscosity is very low.
It is also easy to obtain a high-speed response by adding a chiral liquid crystal compound and providing spontaneous polarization as S01 liquid crystal, and the latter method is currently becoming mainstream.

As a chiral liquid crystal compound added to an SC liquid crystal composition, it is not necessary to exhibit an SC* phase alone, and it is not necessarily necessary to exhibit a liquid crystal phase, but in order not to narrow the temperature range of the composition, It is desirable that the liquid crystal phase exhibits a liquid crystal phase, especially an SC phase.1.In order to obtain a composition with a sufficiently large spontaneous polarization by adding a small amount of a chiral compound, it is necessary to A compound was desired.

[Problem that the invention seeks to solve]

The problem to be solved by the present invention is that it has a large spontaneous polarization and, in many cases, itself has an SC* phase.
The object of the present invention is to provide a novel chiral liquid crystal compound that exhibits an SC* phase over a wide temperature range including room temperature, either alone or in combination, and is capable of high-speed response.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention has been made to solve the above-mentioned problems. n each independently represents 1 or 2, C* and C**
provides compounds whose absolute configuration is (representing 81 asymmetric carbon atoms), each independently of the other.

The compound of formula (1) according to the present invention can be produced, for example, according to the following production method.

...0 [R1, R2, m, n in the above formulas (■) to (■)
, C" and C0 are R1, R2, m in formula (1)
, n, C" and C'**, respectively, and H
at represents a halodane atom. ] First step - After suspending a base such as sodium hydride in tetrahydrofuran (hereinafter abbreviated as THF) and dropping a THF solution of optically active 2,4-bentanediol, the halogen of formula (■) The alkyl compound was added and reacted. After the reaction is complete, dilute hydrochloric acid and ether are added to the reaction mixture for extraction, the organic layer is separated and dehydrated, the solvent is distilled off, and the resulting six-set product is purified by silica gel column chromatography to obtain the formula (2). optically active 1-methyl-3-alkoxybutanol is produced.

Step 2 - The compound of formula (to) and the acid chloride of formula (IV) are dissolved in pyridine and reacted by refluxing the solution. After completion of the reaction, add ethyl acetate, dilute hydrochloric acid and saturated carbonic acid.I) Wash with rum aqueous solution.

Wash the organic layer with water until the aqueous layer is neutral. The organic layer is dehydrated, the solvent is distilled off, and the resulting crude product is subjected to silica dull column chromatography to prepare a compound of formula (b).

3rd step - Dissolve the compound of formula ω in ether, add benzylamine to the solution, perform deacetylation reaction, wash with dilute hydrochloric acid, and wash the organic layer with water until the aqueous layer becomes neutral. . The organic layer is dehydrated and the solvent is distilled off to produce an optically active phenol derivative of formula (Vl).

Step 4 - The compound of formula (Vl) and the acid chloride of formula (Vll) are dissolved in pyridine and reacted by refluxing the solution. After the reaction is completed, ethyl acetate is added, and the mixture is washed with dilute hydrochloric acid, saturated carbonic acid, and an aqueous IJ solution, and the organic layer is washed with water until the aqueous layer becomes neutral. The crude product obtained by dehydrating the organic layer and distilling off the solvent is purified by silica gel column chromatography, and further recrystallized from ethanol to produce ffI, thereby producing the compound of formula (■) according to the present invention. be able to.

Note that the acid chloride of formula (IV) can be produced, for example, according to the following production method. 4-hydroxybenzoic acid (if n=1) or 4'-hydroxybenzoic acid
4-Calanoic acid (in the case of n=2) and acetic anhydride are mixed in chloroform, and a few drops of concentrated sulfuric acid are added to this mixture to cause a reaction. After the reaction is completed, insoluble matter is filtered off, and the organic layer is washed with water until the aqueous layer becomes neutral. The organic layer is dehydrated and the solvent is distilled off, and the resulting acetate is reacted with a chlorinating agent such as thionyl chloride in the presence of several drops of pyridine. Excess thionyl chloride is distilled off from the reaction mixture, toluene is added, insoluble matter is filtered off, and toluene is distilled off.
The acid chloride of formula (IV) can be prepared.

Table 1 lists the transition temperatures of typical compounds of formula (1) that can be produced in this manner.

The liquid crystal phase and phase transition temperature were measured using a polarizing microscope equipped with a temperature control stage and a differential scanning calorimeter (DSC), but the transition temperature may vary depending on the purity of the sample or the measurement conditions. It is subject to change.

In Table 1, C represents a crystalline phase, SC'' represents a chiral nematic C phase, SB represents a smectic B phase, SA represents a smectic human phase, and I represents an isotropic liquid phase. - represents the absence of that phase, the number to the right of . represents the transition temperature from that phase to a phase in a higher temperature range, and the numbers in parentheses represent that the phase is monotropic, (★) indicates that the phase exists during rapid cooling.

The structural feature of the compound of formula (1) is that it has a plurality of asymmetric carbon atoms in the molecule.

To date, there are no examples of ferroelectric liquid crystals using optically active diol derivatives. By the way, the dipole moments of the ferroelectric liquid crystals synthesized so far are not sufficiently oriented, considering the magnitude of the spontaneous polarization actually measured.
This was pointed out by Davld M. Walba et al. (Journal of th@AmericanC
chemical 5oelety, 1986.108
．． 5210-5221) The reasons for this include rotation of the liquid crystal molecules around the long axis of the liquid crystal molecules and rotation within the liquid crystal molecules;
Photography, etc. are being considered. The compound of formula (1), which is an optically active ntandiol derivative, has extremely large spontaneous polarization. This has a branched methyl group bonded to multiple asymmetric carbon atoms in the molecule, which inhibits the movement of these molecules, and K has an asymmetric carbon atom near the core and carnonyl group, so it has a large spontaneous movement. It seems to have polarization.

Now, as SC liquid crystal compounds or compositions to be used alone or in combination with compounds of formula (1), examples of bicyclic compounds include phenylbenzoate compounds (1) and pyrimidine compounds (such as odors, etc.) as shown below. can be given.

A: (R,, R4 represents any one of a linear alkyl group, an alkoxy group, an alkylcarnonyloxy group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group, and may be the same or different. )B; (Rs s Ra represents a linear alkyl group or an alkoxy group, and may be the same or different.) These can be used alone, but as a composition of two or more components. It is advantageous to use this method because a wider temperature range can be obtained. In addition to (m), (g), and (g), those in which the alkyl group in the side chain is a straight chain and exhibit an SC phase can be similarly used. Furthermore, even if a compound other than (B) does not exhibit an SC phase itself, if it is a liquid crystalline compound with low viscosity, it may be added in small amounts to reduce the viscosity of the composition and increase the response speed. This is an effective way to obtain it.

Now, 10-40% of the compound of formula (1) is added to the SC liquid crystal composition.
sc” liquid crystal composition obtained by adding about %
It has a spontaneous polarization of /an"ka10 fi C/c1n" and exhibits high-speed response on the order of microseconds at room temperature. For example, compound 10.A3 shown in Table 1. ii% and.

2fi! Among the phenylbenzoate compounds shown in A as examples of SC liquid crystal compounds or mixtures, three components in which R5 and R4 are both alkoxy groups (R3=R4" n-
C, Hl, o-I R5” n-CaHl 70- *
R4==n-C9H,p-:Rs”n-C6H1s
−+ R4”n-CeH4,-), etc.
9 of C liquid crystal composition (hereinafter abbreviated as base SC liquid crystal)
The liquid crystal composition consisting of 01f% has a spontaneous polarization of 3.3 C/Cm'' and exhibits a high-speed response of 80 μsec at 43°C.

The obtained liquid crystal compound or composition can be used as a liquid crystal display cell by forming a thin film with a uniform thickness (about 1 μm to 20 μm) between two transparent electrode plates.

In a display cell, liquid crystal molecules need to be so-called homosonic and uniformly oriented heptadomains in which the long axis of the molecules is parallel to the electrode plane. For this purpose, either the surface of the 'e1 electrode plate is subjected to an alignment treatment such as rubbing or vapor deposition, or an electric field or magnetic excitation is applied.
Alternatively, a direction is generally adopted in which the isotropic liquid phase is gradually cooled and oriented from the isotropic liquid phase to the liquid crystal phase by providing a temperature gradient or by using a combination of two or more of these methods. Even in the compound or composition of the present invention, uniformly oriented monodomain cells can be obtained by such a method.

〔Example〕

The present invention will be specifically explained below with reference to Examples, but of course the gist and scope of the present invention are not limited by these Examples.

Example 1 4'-((IR,3R)-1-methyl-3-ethoxybutyloxycar-nyl)phenyl 4-dodecyloxybenzoate (- at maximum (1) R1=n-C12
H250-, R2=-C2H51m=1, n=1
, X=-Coo-).

(a) (IR,3R) Synthesis of -1-methyl-3-ethoxybutanol 1.15.9 (48 mmol) of sodium hydride was mixed with 30 of tetrahydrofuran! Suspend in ILt, heat this suspension to 50 ° C., and while maintaining the same temperature, dropwise add a solution of 5 g (48 mmol) of (2R,4R)-bentanediol dissolved in tetrahydrofuran 207114 to this suspension. did. After stirring for 1 hour, iodoethane 9 was added to the mixture.
．． 9 (57.7 mmol) was added dropwise, and the mixture was further stirred for 6 hours. Next, leave to cool to room temperature, 10% hydrochloric acid 20rn
After adding 300 Inl of ether and stirring, the organic layer was separated. The aqueous layer was further extracted twice with ether lQQmj, and the organic layers were combined and dehydrated over anhydrous sodium sulfate.

The solvent was distilled off and subjected to silica gel column chromatography (
Purified with (xR, 3
R) -1-methyl-3-ethoxybutanol 4.24
．． 9 (yield 66%) was obtained.

(b) 4-((IR,3R)-, 1-methyl-
Synthesis of 3-ethoxybutyloxycargonyl)phenol.

4-Hydroxybenzoic acid 104,9 (0,753 mol)
3 drops of sulfuric acid were added to a mixture of 150 g (1.50 mol) of , IIk aqueous vinegar rlR, and 300 d of chloroform, and the mixture was stirred for several hours. After filtering off insoluble matter, the organic layer was washed with water until the aqueous layer became neutral. The organic layer was dehydrated with anhydrous sodium sulfate, the solvent was distilled off, and 4-7 setoxybenzoic acid 90.9j
1 (yield 72%) was obtained. To 15.0.9 of the obtained 4-acetoxybenzoic acid were added 15.9 of thionyl chloride and a few drops of pyridine, and the mixture was refluxed for 3 hours. Excess thionyl chloride was distilled off, 5 d of toluene was added, insoluble materials were filtered off, toluene was distilled off, and 4-acetoxybenzoic acid chloride 13.
2.9 (yield 80%) was obtained.

Obtained 4-acetoxybenzoic acid chloride 5.06J
' and (IR,3R)-1-methyl-3-ethoxybutanol (3.36N) were dissolved in 20ml of pyridine and refluxed for 3 hours. After cooling to room temperature, 200 g of ethyl acetate was added, and the mixture was washed successively with 10% hydrochloric acid and a saturated aqueous sodium carbonate solution, and the water washing was repeated until the aqueous layer became neutral. The organic layer was dehydrated over anhydrous sodium sulfate, the solvent was distilled off, and purified by silica gel column chromatography to obtain 4-[(IR
,3R) -1-methyl-3-ethoxybutyloxycar? phenyl acetate) 5.39.9 (yield 72
%) was obtained.

The obtained 4-((IR,3R)-1-methyl-3-
The mixture was dissolved in 50 ml of (ethoxybutyloxycargenyl)phenylacetyltraether, 14 d of benzylamine was added thereto, and the mixture was stirred at room temperature for 30 minutes. Wash with 10% hydrochloric acid,
The water wash was repeated repeatedly until the aqueous layer became neutral. The organic layer was dehydrated with anhydrous sodium sulfate, the solvent was distilled off, and 4-((I
R,3R)-1-methyl-3-ethoxybutyloxycarzenyl)phenol 4゜59II (yield 99%) was obtained.

(c) 4-((IR,3R)-1-methyl-3
4-((IR,3R)-1-methyl-3-ethoxybutyloxycaryl)phenol obtained in synthesis (b) of phenyl 4-dodecyloxyphenylpenzoate 500rn9 and 4-dodecyloxybenzoic acid chloride were dissolved in 650m95-pyridine8 and refluxed for 3 hours. Cool to room temperature, add 100 g of ethyl acetate, and dilute to 10%
The mixture was washed successively with an aqueous solution of hydrochloric acid and saturated hydrogen carbonate, and the washings were repeated repeatedly until the aqueous layer became neutral. The organic layer was dehydrated over anhydrous sodium sulfate, the solvent was distilled off, and purified by silica column chromatography, and further recrystallized from ethanol to give 4-[(IR,3R)-1-
445 ml of methyl-3-ethoxybutyloxycarginyl)phenyl 4-dodecyloxybenzoate was obtained.

This compound exhibits an SA phase upon rapid cooling. Melting point = 31.
5℃.

Example 2 4-((IR,3R)-1-methyl 3-ethoxybutyloxycar♂yl)phenyl 4'-decyloxybiphenyl 4-carboxylate (-R in formula (1)
1””n-Cl0H210-* R2””-C2H5z
Synthesis of m=2*n=1 rx=-coo-).

In Example 1 (e), 4'-decyloxybiphenyl-4-carboxylic acid chloride was used instead of 4-dodecyloxybenzoic acid chloride, and 4-((IR
,3R)-methyl-3-ethoxybutyloxycar? phenyl) phenyl 41-decyloxypi 12-4-cal♂xylene) was obtained.

Phase transition temperature: 5A-1 = 125.5℃SC-8A
= 112.0°C Melting point = 57.0°C Example 3 (IR, 3R) -1-methyl-3-ethoxybutyl 4
'-Dodecyloxybiphenyl-4-carxylate (-In formula (1), R1=-C42H250-,
Synthesis of R2=-C2H51m"1*n=1+X=single bond).

1.9 of 4'-dodecyloxybiphenyl-4-carboxylic acid chloride and 0.33.9 of (IR,3R)-1-methyl-3-nitoxybutanol were dissolved in 1Qml of pyridine, and the mixture was heated and stirred for 2 hours. . The same purification as in Example 1 (c) was carried out to obtain (IR, 3R) -1-methyl-3-ethoxybutyl 4'-dodecyloxybiphenyl-4-cal? xylene) 0.63.9 was obtained.

This compound exhibits an SA phase upon rapid cooling. Melting point = 35℃
.

Example 4 4-((IR,3R)-1-methy/L/-3-d
7-tyloxybutyloxycarinyl)phenyl4'
-dodecyloxypiphenyl-4-carboxylate (
- In formula (1), R1=n-C12H250-*
R2=-n-C5H11mm=2 # n=1 e X
Synthesis of =-COO-).

4- obtained in the same manner as (m) and (b) of Example 1
((IR.

3R) -1-Methyl-3-pentyloxybutyloxycarbonyl)phenol and 4-dodecyloxybenzoic acid chloride are reacted in the same manner as in Example 1 (e),
Purified, 4-((IR,3R)-1-methyl-3-
pentyloxybutyloxycarnonyl) phenyl 4'
-dodecyloxybiphenyl-4-carboxylate was obtained.

Phase transition temperature 28A-I = 102.0℃SC-8A
= 92.0°C Melting point = 58.0°C Example 5 4'-((IR,3R)-1-methyl-3-ethoxybutyloxycarbyl)biphenyl-4-yl 4-
Decanyloxybenzoate (-formula (R in 1)
,=n-C10H210-, R2=-C2H5, m=1
, n=2.

Synthesis of x=-coo-).

(IR, 3R) obtained by carrying out the same operation as in Example 1 (b) using 4-hydroxybiphenyl-4-carboxylic acid in place of 4- and droxybenzoic acid.
-1-Methyl-3-ethoxybutyl 4/ -hydroxybiphenyl-4-carxylate was purified by reacting 4-decyloxybenzoic acid chloride in the same manner as in Example 1 (c), and purified 4'-((IR .

3R) -1-methyl-3-ethoxybutyloxycarnonyl)biphenyl-4-1-4-decanyloxybenzoate was obtained.

IR:1730.1620.1520.1280.11
70.1120゜1080.850,770 (cm
)MS: w/@=588 (P”) Phase transition temperature: 5A-I =108.5℃SC-8A
= 84.0°C Melting point = 56.0°C Example 6 4'-((IR,3R)-1-methyl-3-ethoxybutyloxycar?nyl)biphenyl-4-yl 4-
Nonylbenzoate (-R,=n- in formula (1)
C, H, tp-m R2=-C2H5# m=1e n
=zex=-coo-).

(IR,3R) -1-methyl-3-ethoxybutyl4
1-Hydroxybiphenyl-4-cal&xylate and 4-nonylbenzoic acid chloride were added in Example 1 (c) and f.
After the JIK reaction, L, 4'-((IR, 3R)
-1-)fk-3-ethoxybutyloxycarbonyl)biphenyl-4-yl 4-nonylbenzoate was obtained.

Phase transition temperature: 5A-1 = 77.0°C 5B-8A =
60.0°C Melting point = 36.5°C Example 7 4'-((IR,3R)-1-methyl-3-pentyloxybutyloxycarnonyl)biphenyl-4-yl4-decanyloxybenzony)( - Formula (1) % Formula % Obtained in the same manner as in Example 5 (IR, 3R) -1-
Methyl-3-pentyloxybutyl 4'-hydroxypiphenyl-4-car-xylate and 4-decanyloxybenzoic acid chloride were reacted in the same manner as in Example 1 (c) and purified to give 4'-[(IR, 3R) -1-Methyl-3-pentyloxybutyloxycal? Biphenyl-4-yl 4-decanyloxybenzoate was obtained. Phase transition temperature: 5A-1 = 93.0°C SC-8A =
76.5°C Melting point = 71.5°C Example 8 Creation of optical switching device using compound (1) 4-((IR,3R)-1-methyl- obtained in Example 2)
3-Ethoxybutyloxycarbonyl)phenyl4'-
Decyloxybiphenyl-4-carxylate was heated to form an isotropic liquid, which was then connected to two glass transparent electrodes (one of which was subjected to polyimide rubbing alignment treatment) via a 2.5 μm thick spacer. ) to create a thin film cell.

Slow cooling was performed at a rate of 5°C per minute to orient the SA phase.
Uniform SC* phase monodomains were obtained at temperatures below 2°C.

When a rectangular wave of 25 V and 50 Hz was applied to this cell and the transmitted light intensity was measured, a fast response of 313 μsec at 50° C., for example, was confirmed. Also.

The value of spontaneous polarization at this time was 121 nc/-.

Example 9 Preparation of an SC* liquid crystal composition consisting of a liquid crystal composition exhibiting an SC phase and a compound of formula (1).

An SC liquid crystal composition consisting of equal weights of 4-octyloxyphenyl 4-octyloxybenzoate, 4-octyloxyphenyl 4-nonyloxybenzoate, and 4-hexyloxyphenyl 4-nonyloxybenzoate was prepared. The phase transition temperature of this composition is N-4 = 81°C
, 5A-N=73°C.

5C-8A=66.5°C, melting point: 43°C.

This SC liquid crystal composition (90% by weight) obtained in Example 3 (IR
,3R) -1-methyl-3-ethoxybutyl 4'-dodecyloxypiphenyl-4-car-xylate 101
An sC* liquid crystal composition consisting of f% was prepared. The phase transition temperature of this composition is N''-1=74°C.

5A-N" = 72°C, SC"-8A = 51°C, melting point = 42°C. Using this SC" liquid crystal composition, a cell similar to Example 8 was created, and its spontaneous polarization and The response time was measured and the value at 43° C. was 3.3 nc24- and 80 μsec.

〔Effect of the invention〕

The compound of formula (1) according to the present invention, when used alone or in combination to form an SC* liquid crystal composition, has a large spontaneous polarization compared to conventionally known ester-based ferroelectric liquid crystal compounds. There is.

Furthermore, as shown in the examples, the compound of formula (1) according to the present invention can be easily produced industrially, is colorless in itself, and has chemical stability against light, moisture, heat, etc. It is excellent and very practical.

Furthermore, the ferroelectric liquid crystal compound and the composition containing the same in the present invention have a response speed that is one of those of conventional nematic liquid crystals.
It is extremely fast, 00 times or more, and is extremely useful as an optical switching element for display.

Agent Patent Attorney Katsutoshi Takahashi

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ Representation, R
_2 represents an alkyl group having 1 to 10 carbon atoms, and X represents ▲a mathematical formula, a chemical formula, a table, etc.▼, ▲a mathematical formula, a chemical formula,
There are tables etc. ▼ or represents a single bond, m and n each independently represent 1 or 2, C^* and C^*^
* represents an asymmetric carbon atom whose absolute configuration is (R) or (S), each independently. ).