JPH02268167A - Optically active compound and use thereof - Google Patents

Abstract

NEW MATERIAL:The optically active compound of formula I [encircled P is group of formula II, formula III, etc.; R is alkyl, alkyloxy or alkyloxycarbonyl; L is-COO-,-OCO or direct bond; Q is -O- or direct bond; m is 0 or 1; at least one of R and CF3OCF(CF3) is optically active]. EXAMPLE:4-(5-Decyloxy-2-pyrimidinyl)benzoic acid 4'-(perfluoro-1- propyloxyethylcarbonyl)phenyl ester. USE:A component of liquid crystal composition. An optical switching element. PREPARATION:A compound of formula I wherein L is -OCO-, Q is -O- and m is 1 can be produced e.g. by reacting hydroquinone with a compound of formula N and reacting the resultant compound of formula V with a compound of formula VI.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides novel optically active compounds, liquid crystal compositions containing the compounds, and liquid crystal compositions containing the compounds or at least one of the compounds. The present invention relates to an optical switching element configured with.

[Conventional technology]

Currently, the display systems of liquid crystal display elements that are widely used in practical use are the twisted nematic type (TN) and the dynamic scattering type (O3). These are displays using nematic liquid crystal cells that mainly contain nematic liquid crystals, but one of the disadvantages of conventional nematic liquid crystal cells is the fact that the response speed is slow, and the response speed can only be on the order of a few milliseconds at most. can give. This is one of the factors that limits the range of applications of nematic liquid crystal cells. In contrast, it has recently become clear that a faster response can be obtained by using a smectic liquid crystal cell.

It is known that some optically active smectic liquid crystals exhibit ferroelectricity, and there is great interest in their applications. Ferroelectric liquid crystal was developed in 1975 by R.
, B. Meyer (RoB) was first synthesized by Meyer et al. [Journard de Physique (J. Phys.) Vol. amino)−
2'-methylbutylcinname) (DOBAMBC)
It is a Schiff base-based compound, of which the representative example is , and is characterized by exhibiting ferroelectricity in an optically active state, for example, chiral smectic C phase. After that, N.A.C1ark et al. [Applied Physics Letters (^pp1.Ph
ys, Lett.

Volume 36, page 899 (1980)
High-speed response on the microsecond order was discovered in AMBC's thin film cells, and this led to the discovery of ferroelectric liquid crystals, which are being used not only for displays such as LCD televisions, but also for optical printers, by utilizing their high-speed response and memory properties. It is attracting attention as a material that can be used for parts of optoelectronic devices such as heads, optical Fourier transform elements, and light valves. In ferroelectric liquid crystal cells, it is advantageous to use a material with a high dielectric constant and a large spontaneous polarization because the cell can be driven at high speed, so the development of a material with a large spontaneous polarization is desired.

In addition, for practical purposes, it is necessary that the liquid crystal compound or composition itself be stable and exhibit ferroelectricity over a wide temperature range centered around room temperature.

[Problem to be solved by the invention]

However, ship base type compounds such as DOBAMBC have drawbacks in terms of stability against water, light, etc., and the temperature range in which they exhibit ferroelectricity is 40°C or higher (from room temperature to 40°C);
However, it was not suitable for practical use. Therefore, it is highly anticipated that a material system that is physically and chemically stable and has large spontaneous polarization will be developed as a ferroelectric liquid crystal material.

An object of the present invention is to obtain a novel optically active compound that has excellent chemical stability and photostability, has large spontaneous polarization, and has a wide temperature range in the chiral smectic C phase. Further, the present invention aims to provide display elements and the like having high-speed response using such compounds or liquid crystal compositions.

[Failure to solve the problem]

To summarize the present invention, the first invention of the present invention relates to an optically active compound, which represents any of the following general formula I: where R is an alkyl group having 4 or more carbon atoms, an alkyloxy group, or an alkyl group. Oxycarbonyl group, L is -C00- group, -RoC0- group or direct bond, Q
is a 10-group or a direct bond, m is O or 1, and is a group R or C3P? It is characterized by being represented by a small number of 0CF (CFs) groups (one of which is an optically active group).

Moreover, the second invention of the present invention relates to a liquid crystal composition, and is characterized in that it contains at least one kind of the optically active compound of the first invention as a component.

A third invention of the present invention relates to an optical switching element, which is constructed using the optically active compound of the first invention or a liquid crystal composition containing at least one of these compounds as a component. It is characterized by

The compound of the general formula (I) has a central skeleton having an ester structure of phenylpyrazine or phenylpyrimidine,
Furthermore, since there are long-chain substituents (preferably 4 to 18 carbon atoms) at both ends of the molecule, the material itself exhibits liquid crystallinity. Furthermore, this compound has a carbonyl group and a CF3 group directly bonded to an asymmetric carbon, so it has high optical rotation. In addition, the presence of multiple fluorines causes a decrease in surface energy, which is expected to reduce the resistance to domain rotation in the thin cells essential for ferroelectric liquid crystals compared to non-fluorinated compounds. , these properties can be expected to provide high-speed response when used as a display element.

[Production method of compound]

The optically active compound of general formula I in the present invention can be produced, for example, according to the following synthetic route.

R-[F]-coo-○-QCOCF (Ch)OCs
Ft (I, L=-COD-, m= 1) ■ R-[F]-oco-〇-0CF(CF3)OC3Ft
, L=-OCO-, Q=-0-m=R-[F]-
Kano Ju (IX) CICDCF (Ch) OC, F.

(III) First, a hydroxy compound (rV) is produced by reacting optically active perfluoro-2-propyloxypropionic acid (n) with hydroquinone or acid chloride (III) with phenol.

Further, acid chloride (III) is reacted with 4-hydroxybenzoic acid to produce carboxylic acid (V), and acid chloride (VI) is produced using a chlorinating agent such as thionyl chloride.

When m=l, acid chloride (■) and hydroxy compound (IV) or hydroxy compound (■) and acid chloride (■), and when m=00, compound (IX
) and acid chloride (III) to form the general formula (I
) can be produced.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The scope of application of the present invention is not limited by these examples.

Example 1 (a) 2.5 g of phenol was dissolved in 30 rd carbon disulfide, 5 g of ground anhydrous aluminum chloride was added, and while stirring, 8.6 g of optically active perfluoro-2-propyloxypropionic acid chloride (III) was dissolved. A solution of 30ml of carbon disulfide was added dropwise at a temperature below 7°C, and then
Heated under reflux for an hour, poured into dilute hydrochloric acid after cooling, and washed with water.
The solvent was distilled off, and the toluene solution of the residue was passed through a silica gel column [IL, 4-(perfluoro-1-propyloxyethylcarbonyl)phenol (IV, m=
1, Q=direct bond) was prepared.

(b) 2-(4-carboxyphenyl)-5-tyloxypyrimidine 1. After reacting Ig with thionyl chloride by heating for 5 hours, the toluene solution of the product obtained by distilling off thionyl chloride was mixed with compound (TV) 1.3 g of toluene 35 rnl and triethylamine 0.5 mj! The solution was gradually added to a solution of 55±5°C for 8 hours, and after being left overnight, it was poured into an aqueous sodium acetate solution and extracted with toluene. The solvent was distilled off under reduced pressure, and the residue was purified by column chromatography on silica gel using hexane-toluene as a solvent, and further recrystallized using heptane to obtain compound (1): 4-(5-decyloxy- 2-pyrimidinyl) benzoin! −4' −(
perfluoro-1-propyloxyethylcarbonyl)
Phenyl ester was produced.

When this compound was sealed in a glass cell with a gap of about 3 μm between transparent electrodes and observed with a polarizing microscope while applying an electric field of ±5 V, LHz, it was found that the domains reversed as the electric field reversed from 59°C as the temperature decreased. Admitted. Other phase transition temperatures are shown in Table 1 along with other examples. Note that Cry is in a crystalline state, and 80 are ferroelectric chiral smectic C.
phase, which at least partially responds to the electric field. SA indicates a smectic A phase, Ch indicates a cholesteric phase, and ■ indicates an isotropic liquid phase. Also, / indicates that the phase exists.

This compound was sealed in a cell with an electrode gap of 115 μm, and the triangular wave method reported by Miyazato et al. pp1.
Phys, ), 1983, Volume 22, No. 661
page], the value was 176nC.
/crn”.

Example 2 Compound ■: 5-(4-octyloxyphenyl)pyrimidine-2-carboxylic acid was prepared in the same manner as in Example 1 except that 5-(4-octyloxyphenyl)pyrimidine-2-carboxylic acid was used as the raw material pyrimidine compound. Acid-4'-(
perfluoro-1-propyloxyethylcarbonyl)
Phenyl ester was produced.

The phase transition temperature of this compound is shown in Table 1. However, () indicates that the phase is monotropic.

In addition, the value of spontaneous polarization measured in the same manner as in Example 1 was 24
00 jin/cm".

Example 3 2 g of hydroquinone 4.5 g of optically active perfluoro-2-propyloxypropionic acid (II) and U p -)
0.5 g of luenesulfonic acid was heated to reflux with 180 g of toluene, and reacted for 300 hours while removing the water generated from the system with a water separator. After cooling, it was washed with water, dried over anhydrous magnesium sulfate, and a silica gel column was removed. After passing through, the solvent was distilled off and 4-(perfluoro-1-propyloxyethyloxy)phenol (IV, m=1, Q=-
(1-) was produced.

Compound ■: 2-(4-decylphenyl)pyrimidine-5-carboxylic acid was prepared in the same manner as in Example 1(b) using 2-(4-decylphenyl)pyrimidine-5-carboxylic acid and the above compound (IV). -4'-(perfluoro-
1-Propyloxyethyl (propyloxy)phenyl ester was prepared.

The phase transition temperature of this compound is shown in Table 1. However, - indicates that the existence of that phase is not clear.

Furthermore, the value of spontaneous polarization measured in the same manner as in Example 1 was 13
5 nC/cm''.

Example 4 5-year-old cutyloxy-2-(4-hydroxyphenyl)
3.0 g of pyrimidine and 3-triethylamine in 351 d of toluene! Dissolved in optically active perfluoro2-
Propyloxypropionic acid chloride (I[[) 3
．． Gradually drop a solution of 4 g of toluene 30-
After reacting at +4°C for 5 hours and incubating overnight, the mixture was washed with a dilute hydroxide solution and water, and then the reaction mixture of Example 1
Compound (2): 2-(4-(perfluoro-1-propyloxyethyloxy)phenyl-5-octyloxypyrimidine was produced by the same treatment as in (b). The phase transition temperature of this compound is shown in Table 1. As shown.

Example 5 2-(4-(3-methylpentyloxy)phenyl)
Compound ■: 2-(4-(3-methylpentyloxy)phenyl)-5-(perfluorinated di-1 -propyloxyethyl (propyloxy)pyrimidine was prepared. The phase transition temperature of this compound is shown in Table 1.

Example 6 4-(Perfluoro-1-propyloxyethylcarbonyloxy)benzoic acid (■, Q
=-0-) was produced.

Compound 1: 4-(perfluoro-1-propyloxyethylcarbonyloxy)benzoic acid was prepared in the same manner as in Example 1(b) using this compound and 5-year-old ctyloxy-2-(4-hydroxyphenyl)pyrimidine. 4'-(
5-year-old ctyloxy-2-pyrimidinyl) phenyl ester was prepared. The phase transition temperature of this compound is shown in Table 1.

Example 7 Compound ■: 5-(4-octylphenyl) was prepared in the same manner as in Example 1 (b) using 5-(4-octylphenyl)pyrazine-2-carboxylic acid and the compound (TV) in Example 3. Pyrazine-2-carboxylic acid-4'-(perfluoro-1-propyloxyethylcarbonyloxy)phenyl ester was produced. The phase transition temperature of this compound is shown in Table 1.

Example 8 Example 1 using 4-(5-decyloxy-2-pyrazinyl)benzoic acid and compound (IV) in Example 1
Compound ■: 4(5-decyloxy-
2-pyrazinyl)benzoic acid-4'-(perfluoro-
1-propyloxyethylcarbonyl) phenyl ester was produced. The phase transition temperature of this compound is shown in Table 1.

Example 9 Compound ■: 5-[4-(perfluoro-1-propyl) (oxyethylcarbonyloxy)
Phenyl]pyrazine-2-carboxylic acid octyl ester was produced. The phase transition temperature of this compound is shown in Table 1.

Example 10 Compound @: 2-[4-(perfluoro-1-propyl) Oxyethylcarbonyloxy)phenylpyrimidine-5-carboxylic acid hexyl ester was produced. The phase transition temperature of this compound is shown in Table 1.

Example 11 Compound ■: 2-[4-(perfluoro-1-propyloxyethylcarbonyl) Phenyl]-5-decyloxypyrimidine was produced. The phase transition temperature of this compound is shown in Table 1.

table Compound [F] 3MP represents an optically active -3-methylpentyl group.

ry ・63 ・68 ・74 ・31 ・37 ・84 ・78 ・81 ・27 ・46 ・27 86 pieces ・79 (・62) ・89 (・22) ・47 (・78) ・86 ・86 ・33 (・39) ・35 A ・121 ・105 ・116 ・118 ・123 ・102 h ・134 ・124 ・128 ・137 ・131 Example 12 (Liquid crystal composition) For 20 parts by weight of compound (1) in Example 5 , 4-( of the following structural formula, which is a non-chiral smectic liquid crystal
2-methylbutyl)-4'biphenylcarboxylic acid-41
-hexyloxyphenyl ester 30 weight 1, and h 4
-octyloxy-4'-biphenylcarboxylic acid-4'
Nonyloxyphenyl ester 50 weight ff1s G
ffi were combined to prepare a liquid crystal composition.

This liquid crystal composition exhibited an SC temperature in the range of 12 to 61°C, and the temperature range was significantly expanded compared to that of the single compound.

Example 13 (Liquid crystal composition) 20 parts by weight of each of the non-chiral smectic liquid crystal compounds in Example 12 and 4-- A liquid crystal composition was prepared by mixing 40 parts by weight of octyloxybenzoic acid-4'=(2-methylbutyloxy)phenyl ester.

C8 This liquid crystal composition exhibits SC temperature in the range of 4 to 57°C,
Its temperature range was significantly expanded compared to the single compound.

Example 14 Skin Crystal Composition) To 10 parts by weight of each of the compounds ■, ■, and 0 in Examples 1.4 and 10, 20 parts by weight of each of the non-chiral smectic liquid crystal compounds in Example 12 and the following structural formula. A liquid crystal composition was prepared by mixing 30 parts by weight of 2-(4-decylxyphenyl)-5-octylpyrimidine.

This liquid crystal composition exhibits an SC zero phase in the range of -8 to 55°C,
The temperature range was significantly expanded compared to when each compound was used alone.

As shown in the three examples above, by mixing the compound of the present invention with a liquid crystal compound having a different structure, a liquid crystal composition that becomes a chiral smectic C liquid crystal in a wider temperature range than when used alone and above and below room temperature can be obtained. can be obtained.

Example 15 (Optical switching element) A polyimide film formed on a glass surface with transparent electrodes was subjected to rubbing alignment treatment, and the compound obtained in Example 2 was placed in a glass cell in which the gap between the transparent electrodes was maintained at 3 μm with alumina powder. was heated and filled as an isotropic liquid. This cell was slowly cooled and maintained at 55°C, ±20V, 1
As a result of measuring the change in transmitted light intensity using a photomultiplier tube when a square wave of 0 Hz was applied, the response time for a change in light intensity of 0 to 90% was 45 μsec, indicating a high-speed response. Ta.

Example 16 (Optical switching element) A cell was produced in the same manner as in Example 15 using the liquid crystal compositions prepared in Examples 12 to 14. Measured temperature 40
The response times determined under the same conditions as Example 15 except that the temperature was 107.85 and 54 μsec, respectively, were found to exhibit high-speed response.

〔Effect of the invention〕

As explained above, according to the present invention, by using the optically active compound represented by the general formula I or a liquid crystal composition containing at least one of these optically active compounds as a component, the spontaneous polarization is large. When used as a display element, it is possible to provide not only a high-speed response but also a material system and an optical switching element that exhibit a chiral smectic phase over a wide temperature range.

Claims (1)

[Claims] 1. The following general formula I: ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) [However, [P] is ▲There are mathematical formulas, chemical formulas, tables, etc.▼,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
Represents any of the following: ▼, ▲Mathematical formulas, chemical formulas, tables, etc.▼, R is an alkyl group with 4 or more carbon atoms, an alkyloxy group, or an alkyloxycarbonyl group, L is a -COO- group, -OCO - group or direct bond, Q is -O-
a group or a direct bond, m is 0 or 1, and the group R or C
At least one of the _3F_7OCF (CF_3) groups is an optically active group. 2. A liquid crystal composition containing at least one optically active compound according to claim 1 as a component. 3. An optical switching element constructed using the optically active compound according to claim 1 or a liquid crystal composition containing at least one of the compounds as a component.