JPH0262847A - Optically active compound and use thereof - Google Patents

Abstract

NEW MATERIAL:An optically active compound shown by formula I [W to Z are F or Cl; Q1 is O or OCO; Q2 is COO or OCO; m is 1 or 2; R is >=4C alkyl; at least one of CF(CF2)OC3F7 and R is optically active group]. EXAMPLE:4-(4-Octyloxytetrafluorobenzoyloxy)-4'-(perfluoro-1- propyloxyethylcarbonyl)biphenyl. USE:A liquid crystal compound useful for producing optical switch element having high-speed responsibility, having excellent chemical stability, optical stability, high spontaneous polarization and a wide temperature range of chiral smectic C phase. PREPARATION:A compound shown by formula VI is condensed with a compound shown by formula III or a compound shown by formula VII is condensed with a compound shown by formula VIII in the presence of a basic substance to give a compound shown by formula Ia or Ib.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a novel optically active compound, a liquid crystal composition containing the compound, and a liquid crystal composition containing the compound or at least one of the compounds. The present invention relates to an optical switching element composed of.

[Prior Art] Display systems of liquid crystal display elements that are currently widely used in practical use are twisted nematic type (TI) and dynamic scattering type (D8). 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 that the response speed is slow, and the response speed can only be on the order of a few milliseconds at most. can be given. This is a factor that limits the range of applications of nematic liquid crystal cells. On the other hand, it has recently become clear that a smectic liquid crystal cell can be used to obtain three answers faster.

It is known that some optically active liquid crystals exhibit ferroelectricity, and there is great interest in their applications. Ferroelectric liquid crystal was developed in 1975 by Mayer (R,B.

Mayer) et al.
, Phys, '), Volume 36, LIS? Page (19
75)] was first synthesized by Yoshikazu, but it is 4-(4
-decyloxybenzylideneamino)-2'-methylbutylcinname) (CDOBAMEO) is a typical thick base compound, which is in an optically active state
For example, it is characterized by exhibiting ferroelectricity in chiral smectic C phase. After that, Clark (M
, Mu, O'1ark) et al.
Letters (AppLPhys, Lett, ), No. 3
Volume 6, page 899 (1980)] Yoshi, DOBAM
High-speed response on the order of microseconds was discovered in EOO 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 printer heads, by taking advantage of 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 optical Fourier transform elements and light valves. In a ferroelectric liquid crystal cell, 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, thick base type compounds such as DOEAMBO have problems in terms of stability against water and light, and the temperature range in which they exhibit ferroelectricity is 4 CIC or higher than room temperature. However, it was not suitable for practical use. Therefore, there are strong expectations for the realization of materials that are physically and chemically stable and have large spontaneous polarization as ferroelectric liquid crystal materials.

An object of the present invention is to obtain a novel liquid crystal 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.

[Means for Solving Section M] To summarize the present invention, the first invention of the present invention is an invention relating to an optically active compound, which has the following formula I: (wherein W, X, Y and 2 are Fluorine or chlorine, ql
is -〇- group or -0CO- group, q is -COO- group or -0aO- group, m is a number of 1 or 2, R is an alkyl group having 4 or more carbon atoms, -01F((!F , )00,7 group, or 迦R, at least 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 fifth 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 the compounds as a component. It is characterized by

The above formula IO compound has a central skeleton having a benzoic acid ester structure, and further has long chain substituents (
(preferably having 4 to 18 carbon atoms), it itself exhibits liquid crystallinity. In addition, this compound has a carbonyl group and a ClPm group directly bonded to the asymmetric carbon, and the dipole moment of fluorine or chlorine acts transversely to the long axis of the molecule, so it has a high degree of optical rotation. . In addition, due to the presence of multiple fluorine atoms, the surface energy decreases, which is expected to reduce the resistance to domain rotation in the thin cells essential for ferroelectric liquid crystals compared to non-fluorinated compounds. , When these elements are combined and used as a display element, high-speed 6-response performance can be expected.

[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.

(In the case of L = -OH, group) (L = -OR or -〇Eken) (■) (I%Qs=-0-1c4., = -aoo-) (!,
Q, = -000-1Q, = -000-) The above manufacturing process f: a.
The compound (lIDt- is prepared by diacylation with I).

When L removes a methyl group in the compound @), it is oxidized with an oxidizing agent such as potassium permanganate to form a carboxylic acid compound (
goods).

On the other hand, 4-alkyloxypolyfluorobenzoic acids (V
) 'Th using a chlorinating agent such as thionyl chloride to form cyanoyl chloride (4).

Finally, acid chloride (4) and phenolic compound @)
Alternatively, the compound of general formula 1 can be produced by condensing the phenol compound (4) and the acid chloride of phenol compound (4) in the presence of a basic substance.

In addition, in the above manufacturing process, polyfluorobenzoic acid (
esters) (V, ■).Reference 1: Birchall (J, M, Birahall) et al., Journal of Chemical Research (J.

OMm, 8oa, ), 1971, No. 1545
It can be produced from tetrafluoro-al or chlorofluoro-benzonitrile according to page 2: Akio Takaoka, Nobuo Ishikawa et al., Journal of the Chemical Society of Japan, 1985, p. 2155.

Regarding compound (translation), for example, Document 3: Clark (H, T, 01arke), Organic Synthesis (Organic Synthesis), etc.
) Collective Volume Volume ■, Page 135 (1
966), it can be produced according to the synthesis of 0-chlorobenzoic acid.

When using matarasemic perfluoro-2-propyloxypropionic acid chloride, - Formula (7) ~
The compound of general formula (1) can be produced using a compound in which one alkyl group in the compound (2) is optically active.

〔Example〕

Below, the present invention will be put into practice! ! Although a more specific explanation will be given below, the scope of application of the present invention is not limited by these Examples.

Implementation row 1 F? (However, 0 represents an asymmetric carbon.) (a) Dissolve 4t of 4-hydrogysibifuC,, = 4t in 120-carbon disulfide, add 5t of anhydrous aluminum chloride, and stir while stirring the optically active perfluorinated 2- Probyloxyglopionic acid chloride (II) 7.8F/
Solution i1 of 50-carbon disulfide (Dropped below Ic, heated under reflux for 7 hours, cooled, poured into dilute hydrochloric acid, water, cooled oxyhydrogen solution) The toluene solution of the residue was passed through a silica gel column, the solvent was distilled off, and 4-hydroxy-4'-(berfluoro-1-propyloxyethylcarbonyl)piphenyl (il1%L=-011%m =2) 12F
'S: Got it.

伽) Metallic sodium IJium in a nitrogen atmosphere 2. ．． 5t, 1
-Octanol 169 and toluene 250- are heated and stirred, and after the sodium has dissolved, toluene is distilled off under reduced pressure, and pentafluorobenzonitrile 191ON-
Add 140ml of methylpyrrolidone solution to 140±5
The reaction was carried out by heating at ℃ for 20 hours. After cooling, add water and extract with an aqueous sodium carbonate solution, add hydrochloric acid to the aqueous layer and extract with toluene, wash with water and dry over anhydrous magnesium sulfate.
The toluene solution was passed through a silica gel column, the solvent was distilled off, and the residue was heated under reflux with 20% sodium hydroxide for 15 hours. After cooling, diluted hydrochloric acid was added to make it acidic. / to give 4-ocdylfluorobenzoic acid (VsR” OmExt
, W=X=Y=Z=IF) 9.7F was obtained.

(c) Carboxylic acid compound (V) 1 produced in (b)
After adding thionyl chloride 10- to 811F and reacting with heating for 3 hours, the toluene solution of the product obtained by distilling off thionyl chloride was gradually added to the hyridine solution of compound @) t211F and heated at 60 to 68°C for 5 hours. After allowing the reaction to proceed overnight, it was poured into water and extracted with toluene. The toluene solution was washed with a dilute aqueous sodium hydroxide solution, then with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off. In silica gel column chromatography, ms
and further recrystallized from heptane to obtain compound ■: 4-(4
-Octyl oyster tetrafluorobenzoyloxy)
-al ++ <perfluoro-1-propyloxyethylcarbonyl)biphenyl'klu manufactured Lt.

Compound (1) was sealed in a glass cell with a gap of about 3 μm between transparent electrodes, and when observed with a polarizing microscope, the results were 55.7-67.5.
When an electric field of, for example, ±5 V, IHi, was applied in the temperature range of .degree. C., domain inversion was observed as the polarity of the electric field was reversed.

Other phase transition temperatures are shown in Table 1 below along with other examples. However, Cry indicates a crystalline state, BC* indicates a chiral smectic C phase, Bhrl smectic phase, and C indicates an isotropic liquid phase. Note that . indicates that the phase exists.

In addition, this compound was sealed in a cell with an electrode gap of 120 μm,
The triangular wave method reported by Miyazato et al. [K, Miyazato, S, Ape,
■、Tagazoe、Mu、Fukuda (K、Miyasato、Japan、Mube%) 1. Takezoe, A.

IFulcuda) et al., Japanese Journal of Applied Physics (Jpn, J.

AppL ph7a, ), 1983, Volume 22, Page L661], the spontaneous polarization was measured and the value was 124 nc! /a++1.

Example 2 Compound ■: 4-(
4-octyloxy-5-chlorotrifluorobenzoyloxy)-41-(perfluoro-1-propyloxyethercarbonylcopyphenyl) was produced.

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

Spontaneous polarization value id measured in the same manner as in Example 1
It was 158 rxc/i.

Example 3 Compound ■: 4-(4- Tesilo-6-chlorotrifluorobenzoyloxy)-4'-(perfluoro-1-
Propylene carbonyl)biphenyl was produced. The phase transition temperature of this compound is shown in Table 1.

Furthermore, the value of spontaneous polarization measured in the same manner as in Example 1 was 12
It was 0 nO,/3e.

Example 4 Compound ■: 4-(4- 9. Preparation of 2-chlorotrifluorohensoyloxy)-4'-(perfluoro-1-propyrodiethylcarbonyl)biphenyl. The phase transition temperature of this compound is shown in Table 1).

In addition, the value of spontaneous polarization measured in the same manner as in Example 1 was 18
7 no/vice command.

As shown in Example gAU5, by mixing with a non-chiral liquid crystal compound, S
Expression of et phase was observed.

Example 6 Same as Example 1 except that 1-decanol is used instead of 1-octatool, t-3,5-dichlorotrifluorobenzonitrile is used instead of pentafluorobenzonitrile, and phenol is used instead of 4-hydroxybiphenyl. Compound (1): 4-decyloxy-5-dichlorodifluorobenzoic acid-4'-(perfluoro-1-propyloxyethercarbonyl) phenyl ester tn was prepared.

The phase transition temperature of this compound is as shown in Table 1. However, - indicates that the existence of that phase is unclear. This compound was prepared in the same manner as in Example 1 except that 1-hexanol was used instead of y at 1-octatool and 2.4.6-trichlorodifluorobenzonitrile was used instead of pentafluorobenzonitrile as shown in Example 9110. Compound ■: 4-(4-hexyloxy-2,6
-cyclodifluorobenzoyloxy)-4'-(perfluoro-1-probifluorinated diethylcarbonyl)biphenyl was prepared. The phase transition temperature of this compound is shown in Table 1.

Example 7 Optically active 2-octatool was used instead of 1-octatool, 3-chlorotetrafluorobenzonitrile was used instead of pentafluorobenzonitrile, and 7-octatool was used instead of optically active perfluoro-2-propyloxypropionic acid. Compound:4-
(4-(1-methylhebutyloxy)-3-chlorotrifluorobenzoyloxy)-4'-(perfluoro-
1-propyloxyethercarbonyl)biphenyl was produced. The phase transition temperature of this compound is shown in Table 1).

Actual row 8 F? Compound (1): 4-octyloxytetrafluorobenzoic fi-4'-(berfluoro-1-propyloxyethylcarbonyl)phenyl ester' was produced in the same manner as in Example 1, except that phenol was used in place of 4-hydroxybiphenyl. t.

Ta. The phase transition temperature of this compound is as shown in Table 1.

Example 9 Perform 4-methylbiphenyl instead of sibiphenyl in 4-hydro ff1J 1 In the same manner as in (a), 4-
Methyl-4'-(perfluoro-1-propyloxyethercarbonyl)biphenyl was produced. This compound was subjected to an oxidation reaction according to literature 3, and 4-(perfluoro-
1-propyloxyethylcarbonyl) ++ al-
Biphenylcarboxylic acid (conversion) was produced. Compound (1): 4-(perfluoro-1-propyloxyethercarbonyl)-4'-biphenylcarboxylic acid-41-octyloxycarbonyltetra A fluorophenyl ester was produced. The phase transition temperature of this compound is as shown in Table 1.

Aim 0e@@@@@O@(Q Example 10 Liquid Crystal Composition) With respect to the 3D weight part of the compound (■) in Example 5, 4-(
2-methylbutyl)-4'-biphenylcarboxylic acid-4
40 parts by weight of 1-hexyloxyphenyl ester, and 4-octyloxy-4'-biphenylcarboxylic acid-4
1-be/thyloxyphenyl ester 30 parts by weight 5ea
A liquid crystal composition was prepared.

For 20 parts by volume of compound (1) in Example 8, 4-( of the following structural formula, which is a non-chiral smectic liquid crystal)
2-methylbutyl)-4'-biphenylcarboxylic acid-4
A liquid crystal composition was prepared by mixing 70 parts by weight of '-octyloxyphenyl ester and 10 parts by weight of 4-octyloxybenzoic acid-4-(2-methylbutyloxy)phenyl ester.

This liquid crystal composition underwent sc main phase combination in the range of 15 to 55 DEG C., and the temperature range was significantly expanded compared to Compound (1) alone.

Example 11 Liquid crystal composition> This liquid crystal composition undergoes SC main phase combination in the range of 4 to 46°C,
The temperature range was significantly expanded compared to Compound ① alone.

Example 12 (Liquid crystal composition) Example 911 was added to A10.15 and 18 parts by weight of the compounds ■, ■, and ■ in Examples 3.4 and 6, respectively.
A liquid crystal composition was prepared by mixing 45 parts by weight and 12 parts by weight of the non-chiral smectic liquid crystal in Example 1, respectively. This liquid crystal composition exhibited an SC ratio phase in the range of 3 to 43°C, and the temperature range was significantly expanded compared to that of the single compound.

The above three actual hffJ [as shown in MJ, it can be used by mixing liquid crystal compounds with different structures, or it can be used alone] is a liquid crystal composition that forms a chiral smectic O liquid crystal over a wide temperature range and above and below room temperature. can be obtained.

Example 13 (Optical switching element) A polyimide film was subjected to a rubbing alignment treatment, and the compound (1) obtained in Example 1 was heated to form an isotropic liquid in a glass cell with a gap of about 3 μm between transparent electrodes. did. This cell was slowly cooled and maintained at 59°C, and the voltage was set at ±20V, 10Hz.
As a result of measuring the change in the transmitted light intensity using a photomultiplier tube when a square wave of 1 was applied, the response time for a change in light intensity of 0 to 90% was 84 μlNl0, 69, indicating a fast response.

Example 14 (Optical switching device) A cell was prepared in the same manner as in Example 13 using the liquid crystal compositions prepared in Examples 10 to 12. Measured temperature 41
The response times obtained under the same conditions as Example 15 except that the temperature was 3180.155 and 73μ8θC, respectively, indicating high-speed response.

[Effects of the Invention] As explained above, according to the present invention, - Equation! By using an optically active compound represented by or a liquid crystal composition containing at least one member of this optically active compound as a component, high-speed response is possible when used as a display element due to its large spontaneous polarization. In addition, it is possible to provide a material system and optical switching device that exhibits a chiral smectic phase over a wide temperature range.

Claims (1)

[Claims] 1. General formula I: ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] (In the formula, W, X, Y and Z are fluorine or chlorine, and Q_1 is -O- group or -OCO- group, Q_2 is -COO- group or -OCO- group, m is a number of 1 or 2, R is an alkyl group having 4 or more carbon atoms, -CF(CF_3)OC_2F_7
An optically active compound characterized in that at least one of the group or the group R 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 this compound as a component.