JPH0225453A - Optically active compound and use thereof - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I [rings a, b and c contain at least one F or Cl and another ring is formula II (W, X, Y and Z are F or Cl); L is -COO- or -OCO-; Q is -COO- or direct bond; R1 and R2 are >=4C alkyl or alkyloxy and at least either thereof is optically active group]. EXAMPLE:3'-Fluoro-4'-(1-methylheptyloxycarbonyl)phenyl 2-fluoro-4-(4- decyloxytetrafluorobenzoyloxy)benzoate. USE:A chemically and optically stable liquid crystal display element substance having great spontaneous polarization, a wide temperature range of chiral smectic phase and high-speed responsiveness. PREPARATION:A phenolic compound expressed by formula III is condensed with an acid chloride expressed by formula IV in the presence of a basic substance to afford the compound expressed by formula I.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to 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 as a component. The present invention relates to an optical switching element characterized in that it is constructed using.

[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 (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 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 much 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. Mayer (R,B.

Meyer)
J, Phys, ), Volume 36, Page L69 (197
5)), it was first synthesized by 4-(4-
It is a compound of Schiff's base yarn, of which n-dioxybenzylideneamino)-21-methylbutylcinnamate (DOBAMBC) is a typical example, and it can be used in certain conditions.
For example, it is characterized by exhibiting ferroelectricity in the Caif/I/smectic C phase. After that, N.A.

Clark (N, A, Clark) et al. [Applied Physics Letters (Appl, Phys, Let
) Vol. 36, p. 899 (1980)] discovered a high-speed response on the microsecond order in the thin-film cell of DOBAMBC, and this suddenly led to the discovery of the high-speed response of ferroelectric liquid crystals. It is attracting attention as a material that can be used not only for displays such as LCD televisions, but also for parts of optoelectronic devices such as optical printer heads, optical Fourier transform elements, and light pulp, due to its memory and memory properties. . In ferroelectric liquid crystal cells,
The use of a material with a higher dielectric constant and a larger spontaneous polarization is advantageous in that the cell can be driven at higher speed, so the development of a material with a larger spontaneous polarization is desired.

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

[Problem to be solved by the invention]

However, Schiff base-type compounds such as DOBAMBC have drawbacks in terms of stability against water and light, and the temperature range in which they exhibit ferroelectricity is 40°C or more higher than room temperature, making them unsuitable for practical use. It wasn't something. Therefore, there are strong expectations for Higashio, a material system that is physically and chemically stable and has large spontaneous polarization, 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. The present invention also aims to provide display elements and the like having high-speed response using such optically active compounds or liquid crystal compositions.

[Means to solve the problem]

To summarize the present invention, the first invention of the present invention relates to an optically active compound, which includes the following - General 2 I: At least one ring contains one fluorine or chlorine, and the other ring contains Z represents chlorine), L is -Coo- group or -○c〇- group, Q is 1000 group or a direct bond, R1 and R2 are an alkyl group or an alkyloxy group having 4 or more carbon atoms. and & or R2
At least one of them 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 this compound as a component. It is characterized by

The compound of the general formula (1) has a central skeleton having three benzene rings and an ester structure, and further has long chain substituents (preferably having 4 to 18 carbon atoms) at both ends of the molecule. Therefore, it itself exhibits liquid crystallinity. In addition, this compound may have a CH3 group directly bonded to an asymmetric carbon, and it also has high optical rotation because it contains fluorine or chlorine in a direction transverse to the long axis of the molecule. .

Furthermore, since the presence of multiple fluorines causes a decrease in surface energy, it is expected that the resistance to domain rotation will be reduced compared to non-fluorinated compounds in the thin 70°C, which is essential for ferroelectric liquid crystals. , these properties can be expected to provide high-speed response when used as a display element.

[Production method of compound]

The optically active liquid crystal compound of general formula (1) in the present invention is:
For example, it can be produced according to the following synthetic meridian.

however, In the following reaction formula This also includes cases where it represents a Sen ring.

Alternatively, to outline the above manufacturing process, first, 4-alkyloxychlorofluorobenzoic acid (If a) and 4-alkyloxychlorofluorobenzoic acid M (nb and nc) are hydroxylated with tetrafluoro- or chlorofluorobenzonitrile. Produced by reaction with sodium. The above polyhalogenobenzonitrile is described in Reference 1: Virchal Yv (J, M, Birchal
l) and others, Journal of Chemical Society (
J.

chem.

Next, polyhalogenobenzonitrile is subjected to alkaline hydrolysis according to the method described in Document 1 to produce 4-hydroxypolyhalogenobenzoic acid (m a ~ Inc). In addition, these are reacted with alcohols such as optically active alcohols in the presence of an acid catalyst to produce 4-hydroxypolyhalogenobenzoic acid μkylene ethers (ffa to fVc). However, in the reaction with a secondary alcohol, the above reaction is also applicable, but more preferably, the halogen at the 4-position of polyhalogenobenzonitrile is changed to a methoxy group, and the nitrile group is hydrolyzed with an alkali. It is possible to produce a target compound with higher optical purity by producing CPi) by converting it into a carboxylic acid, producing an acid chloride, esterifying it, and then demethylating it.

Next, for the production of monohalogenated benzoic acids, 2-halogeno-4-alkyloxybenzoic acid (I[d) or 2-halogeno-4-hydroxybenzoic acid (Illd) is produced by alkaline hydrolysis of the corresponding nitrile compound. Manufacture. When X is chlorine, this compound is manufactured from the corresponding nitrile compound, and when X is fluorine, it is manufactured from the corresponding nitrile compound, and when X is fluorine, it is manufactured from Reference 3 = Sadao Takehara et al., Proceedings of the 11th Liquid Crystal Symposium, 1
985, p. 176. Compound (ffd) is produced by esterifying (ma) with alcohol-μ.

Next, 3-fluoro-4-alkyloxy-(lie) or 6-fluoro-4-hydroxybenzoic acid (nle) is produced according to Reference 6.

The latter is esterified to produce compound (IVe) in the same manner as in the case of polyhalides.

Also, 4-alkyloxybenzoic acid is N,N-dichloro-
Compound (If) is produced by chlorination using p-)/Reens μphonic acid amino)' (DCT).

Carboxylic acid compound (It) was converted into acid chloride (
V) and the above (ma) to (Il) in the presence of a basic substance.
le) with a compound of general formula (I[[) to produce a carboxylic acid of general formula (Vl). This compound is then converted into an acid chloride of the general formula (■) by a conventional method.

Alternatively, compound (I[) is condensed with a dihydroxy compound (■) in the presence of a basic substance to form a hydroxy compound (IX
) is manufactured.

On the other hand, 4-methoxybenzoyl chlorides) and the hydroxy compound (XI) are esterified in the presence of a basic substance, and then demethylated with aluminum chloride to form the phenol compound (XI). Make M.

Finally, acid chloride (■) and phenolic compound (XI)
, acid blackide (V) and phenolic compound (Xll)
Or phenolic compounds (ff) and acid flora, f
A compound of general formula 1 can be prepared by condensing do(X[[l ) in the presence of a basic substance.

〔Example〕

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

Example 1 (a) Metallic potassium 0752 was converted into N-methylpyrrolitone 5
In addition to 0- and 1-decano A/5at, heat and dissolve to make a homogeneous solution, and pentafluorobenzonitrile lv!
L8t was added and the mixture was heated and reacted at 65-76°C for 12 hours. Add cold drained water and extract toluene, wash with brine, dry over anhydrous magnesium sulfate, distill off toluene under reduced pressure, add 20% aqueous sodium hydroxide solution to the residue, and stir for 4 hours. The mixture was heated under reflux for an hour, made alkaline with an aqueous sodium carbonate solution, extracted with toluene to remove unreacted decyl alcohol, added hydrochloric acid to the aqueous layer, extracted with ether, distilled off the ether, and recrystallized with hexane.
-Decyloxytetrafluorobenzoic acid (■a) was obtained.

(b) Compound 4.21 above with thionichloride 1v20- and 4
The residue obtained by heating under reflux for an hour and distilling off thioni chloride μ under reduced pressure was dissolved in toluene, and this was dissolved in 2-fluoro-4-hydroxybenzoic acid (lllld) 1.9 F of pyridine 3
0- was gradually added to the solution and reacted at 60-68°C for 5 hours, after being left overnight, it was poured into water and extracted with toluene.
The solvent was distilled off through a silica gel column and recrystallized from methanol to obtain 2-fluoro-4-(4-7” siloxytetrafluorobenzoyloxy)benzoic acid (Vl).
was manufactured.

(c) 2-fluoro-4-hydroxybenzoic acid (Iu
d) 7.62 and optically active-2-octatool 11V
was heated to reflux with 5 parts of concentrated sulfuric acid and 140 rnt of toluene, and reacted for 7 hours while removing the produced water from the thread.
Water was added, extracted with toluene, extracted with dilute aqueous sodium hydroxide solution, and this aqueous solution was acidified with hydrochloric acid to obtain an oily substance. This was extracted with ether, washed with water, dried over anhydrous magnesium sulfate, distilled off the ether, and purified with silica gel column chromatography using hexane as a solvent. ,2
-Fluoro-4-hydroxybenzoic di-17-methylhebutyl ester) V (1vd) was obtained.

(cl) Compounds (Vl) and (C) produced in (b)
) was prepared in the same manner as in (b) above, except that hexane-toluene was used as the solvent in silica gel column chromatography, to obtain compound (IV d):
2-Fluoro-4-(4-decyloxytetrafluorobenzoyloxy)benzoic acid-3'-fluoro-4'-
(1-Methylhebutyloxycarbonyl) phenyl ester aL7'c.

(e) Compound (1) was encapsulated in a glass container with a gap of about 3 μm between transparent electrodes, and as a result of observation with a polarizing microscope, it showed an SC* phase from 63° C. upon temperature drop. In this temperature range, for example, when an electric field of ±5 μm, I Hz was applied, domain inversion was observed as the polarity of the electric field was reversed. Other phase transition temperatures are shown in Table 1 below. However, Cry indicates a crystalline state, SC* indicates a chiral smectic C phase, SA indicates a smectic A phase, Ch indicates a cholesteric phase, and C indicates an isotropic liquid phase. Note that 0 indicates that the phase is monotropic, / indicates that the phase exists, and - indicates that the phase is not clear.

In addition, this compound was sealed in a cell with an electrode gap of 120 pm, and the triangular wave method [K] reported by Miyazato et al.

Miyazato, S. Abe, H. Takezoe, A. Fukuda and E. Kuze (K, Miyasato %S, Abe %H, Ta
kezoe, nfukuda, E, Kuze
), Japanese Journal of Applied Physics (Jpn, J.

Appl, Phys, ), 1983, Volume 22,
When the spontaneous polarization was measured on page 661], the value was 83 nC/2.

Example 2 4-decyloxytetrafluorobenzoic acid was substituted with 4-decyloxytetrafluorobenzoic acid.
Decyloxy-2-chlorotrifluorobenzoic acid (Il
b), 4- produced in the same manner as in Example 1(c) from 4-hydroxybenzoic acid and optically active-2-octatool
Compound 1: 2-fluoro-4-(4-decyloxy-2-chlorotrifluorobenzoyloxy) Benzoic acid-47-(1 -Methylhebutyloxycarbonia L/ ) phenyl ester was produced. The phase transition temperature of this compound is as shown in Table 1.

Furthermore, the value of spontaneous polarization measured in the same manner as in Example 1 was 62
nC/lx”.

Example 3 3-fluoro-4-hydroxybenzoic acid (I[Ie)
and 3-fluoro-4-hydroxybenzoic acid-1-methylhebutyl ester (ffe) 4 produced in the same manner as in Example 1(C) from optically active -2-octano-μ and 4-methoxybenzoic acid 2 , 3f in Example 1 (b
) and 4-methoxybenzoic! -:2'-Fluoro-4'-(1-methylhebutyloxycarbonyl)phenyl ester was produced.

Next, 4t of this compound was mixed with 2v of anhydrous aluminum chloride, left for 2 hours, 50-cyclohexane was added thereto and kept at 65-70°C for 3 hours, extracted with Fluene, washed with water, and mixed with anhydrous magnesium sulfate. After drying and passing through a column of silicage μ, the solvent was distilled off and recrystallized from benzene to obtain 4-hydroxybenzoic acid-21-fluoro-4.
'-(1-Methylheptyloxycarbony)V) phenylester)V (Xll) Obtain*.

Then, from this compound and 4-decyloxy-3-chlorotrifluorobenzoic acid (lc), compound (1): 4-(4-decyloxy-3-chlorotrifluorobenzoyloxy)-benzoic acid was prepared in the same manner as in Example 1(d). -2'-Fluoro-41, -(1-methylhebutyloxycarbonyl)phenylester)v was produced. The phase transition temperature of this compound is as shown in Table 1.

Furthermore, the value of spontaneous polarization measured in the same manner as in Example 1 was 73
nC7cm”.

Example 4 The spontaneous polarization value measured in the same manner as Example 1 was 78.
It was nC/α2.

Example 5 F 4-(
4-decylbenzoyloxy)tetrafluorobenzoic acid (Vt) was produced.

Also, 4-hydroxy-2-chlorobenzoic acid (111(1
) to 4-hydroxy-2 in the same manner as in Example 1(c)
-chlorobenzoic acid-1P-methyl hebutyl ester/I/
(ffa) was produced.

Example 1 Using this compound and the above compound (Vl)
Compound (1): a-(4-decylbenzoyloxy)-tetrafluorobenzoic acid-3'-chloro-4'-(1-methylbutyloxycarbonyl)phenyl ester was prepared in the same manner as in (d). The phase transition temperature of this compound is as shown in Table 1.

F 4-octyloxybenzoic acid and 4-hydroxy-2-
From chlorotrifluorobenzoic acid (u[b) to Example 1 (
4-(4-octyloxybenzoyloxy)-2-chlorotrifluorobenzoic acid (Vl) was produced in the same manner as in b). Using this compound and 3-fluoro-4-hydroxybenzoic acid-1'-methyl-hebutyl ester (ffe) prepared in Example 3, compound -octyloxybenzoyloxy)-2-chlorotrifluorobenzoic acid-2'-fluoro-4'-(1-methylhebutyloxycarbonyl)
1Ll of phenyl ester.

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

Furthermore, the value of spontaneous polarization measured in the same manner as in Example 1 was 55
nC/cm".

Example 6 The spontaneous polarization value measured in the same manner as Example 1 was 45.
nC/cm".

Example 7 F 4-(4-decyloxybenzoyloxy)-tetrafluorobenzoic acid (W) was prepared from 4-decyloxybenzoic acid and 4-hydroxytetrafluorobenzoic acid (lna) in the same manner as in Example 1(b). Manufactured. Using this compound and the compound (ffcl) produced in Example 1(c), compound ①: 4-(4-decyloxybenzoyloxy)-tetrafluorobenzoic acid-3 was prepared in the same manner as in Example 1(d). '~Fluoro-4'-(1-methylheptyloxycarbonyl/I/) phenyl ester was prepared.

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

F' F 4-(3-Chloro-4-octyloxybenzoyloxy)benzoic acid ( Vl) 'It: Manufactured. Example 1 Compound (1): 5-(3-chloro-4-octyloxybenzoyloxy)-benzoic acid-4'-(1-methylhebutyloxycarbonyl)tetrafluorophenyl ester was prepared in the same manner as in (d). The phase transition temperature of this metal compound is as shown in Table 1.

Example 8 F 2-fluoro-4-decyloxybenzoic acid (1 [cl)
6 f, hydroquinone 31 and p-) toluenesulfonic acid 1.6 f'i) toluene 150 td,! : Both were heated to reflux, and reacted for 35 hours while removing the water produced from the system with a Dean-Stark water separator. After cooling, it was washed with water, extracted with dilute aqueous sodium hydroxide solution, acidified with dilute hydrochloric acid, and extracted with ether. It was extracted, washed with water, dried over anhydrous magnesium sulfate, ether was distilled off, dissolved in toluene, passed through a silica gel column, the solvent was distilled off, and recrystallized with benzene-hexane. Fluoro-4
-decyloxybenzoic acid-4'-hydroxyphenyl ester IVcM) o'R construction.

4 produced in the same manner as in Example 1(a) except that optically active-2-octatool was used in place of 1-decano μ.
Compound (1): 2-fluoro-4-decyμoxybenzoic acid- 4'-[4-(1-Methylhebutyloxy)tetrafluorobenzoi p-oquine]phenyl ester was produced. The phase transition temperature of this compound is shown in Table 1.

The value of spontaneous polarization measured in the same manner as in Example 1 was 43.
It was nC/α2.

Example 9 3-fluoro-4-decyloxybenzoic acid (11d) and 3-fluoro-4-hydroxybenzoic acid (use) were used in the same manner as in Example 1(b).
4-(2-Fluoro-4-decyloxypenzoyloxy)benzoic acid (■) was completely prepared.

Direct esterification of this compound and 4-hydroxy-6,5-dichlorodifluorobenzoic acid (Inc) with optically active 2-octatool produced a'L, manufactured by Shishi. 4-Hydroxy-3,5-dichlorosifuolobenzoe-1'-
Example 1 using methylheptyl ester (ffc)
Compound 09: 5-fluoro-4-(
2-Fluoro-4-decyloxybenzoyloxy)-
An JL-4'-(1-methyl-heptyloxycarponyl)-27,61-dichlorodifluorophenyl ester was produced. The phase transition temperature of this compound is shown in Table 1.

Example 10 2-Fluorobenzoic acid (lllld) to Example 1(b)
2-Fluoro-4-(4-dodecylbencyfureoxy)-benzoic acid (VT) was produced in the same manner as above.

This compound, 4-hydroxy-2-chlorotrifluorobenzoic acid (mb) and optically active 2-methylbutano-
The compound [ phase]: 2-fluoro-4-(4-dodecylbenzoyloxy)-benzoic acid-4'-(2-methylbutyloxycarbonyl)-3'-10 lotrifluorophenyl ester was prepared. 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 16
It was nC/piece 2.

Example 11 4-Dodecylbenzoic acid and 4-hydroxy-t F 4-hydroxy-3-chlorotrifluorobenzoic acid (I
By direct esterification of nc) with 1-octatool, 4-hydroxy-3-chlorotrifluorobenzoic acid-
Octyl ester (lVc) was produced. 4-Hydroxybenzoic acid-21-chlorotrifluoro-
4'-octyloxyca 7leponyl phenyl ester/L
/(■) was manufactured.

The above compound (store) and 3-fluoro-4-(2-methylbutylbutyl)oxybenzoic acid (I
ce) in the same manner as in Example 1(d) using Nishite compound ■:
4-(3-fluoro-4-(2-methylbutyloxy)
[Benzoyloxy]benzoic acid-4'-octyloxycarbonyl-21-chlorotrifluorophenyl ester was prepared. The phase transition temperature of this compound is as shown in Table 1.

Furthermore, the value of spontaneous polarization measured in the same manner as in Example 1 was 21
It was nC/Bi 2.

Example 12 Example 1(b) was prepared using F CL 2-fluoro-4-decyloxybenzoic acid and 3-fluoro-4-hydroxybenzoic acid.
) in the same manner as 3-fluoro-4-(2-)μo-4
-decyloxy)penzoyluoquine benzoic acid (W) was produced.

This compound and 4-hydroxy-2,6-dichlorodifluorobenzoic acid-2'-methylbutyl ester ~( r
Compound 0 was prepared in the same manner as in Example 1(d) using
:3-fluoro4-(2-fluoro-4-decyloxy)benzoyloxybenzoic acid-4'-(2-methylbutyloxycarbonyl)-37,5/-dichlorodifluorophenyl ester was produced. The phase transition temperature of this compound is shown in Table 1.

Example 13 <Liquid crystal composition> For 25 parts by weight of compound (1) in Example 1, 4'-
(2-methylbutyl)-4-biphenylcarboxylic acid (4
-octyloxyphenylene lv) ester/l/32 parts by weight, and 4'-octyloxy-4-biphenylcarbon d(4-bentyloxyphenylene/l/) ester 43
A liquid crystal composition was prepared by mixing all the ingredients.

This liquid crystal composition exhibited an SC* phase in the range of 10 to 57°C, and the temperature range was significantly expanded compared to each compound alone.

Example 14 Liquid crystal composition Compounds in Examples 8 to 10
．． 33 and 3 parts by weight of the non-chiral smectic liquid crystal in Example 13 were added to 12 and 15 parts by weight, respectively.
A liquid crystal composition was prepared by mixing 0 parts by weight. This liquid crystal composition exhibited an SC* phase in the range of 8 to 62°C, and its temperature range was significantly expanded compared to the single compound.

As described above, by mixing liquid crystal compounds with different structures, a liquid crystal composition can be obtained which exhibits a chiral smectic C liquid crystal phase above and below room temperature in a wider temperature range than when used alone.

Example 15 Luminous switching element> The compound (1) obtained in Example 4 was placed in a glass cell in which the polyimide on the transparent electrode was subjected to a rubbing alignment treatment, and the gap between the transparent electrodes was maintained at about 3 μm using alumina powder. The mixture was heated to form an isotropic liquid phase and then evaporated. When this cell was slowly cooled and maintained at 65°C and a square wave of ±20V and 10Hz was applied, the change in transmitted light intensity was measured using a photomultiplier tube. Response time is 78
It showed high-speed response in μsec.

Example 16 Light Switching Element> A cell was produced in the same manner as in Example 14 using the liquid crystal compositions prepared in Examples 13 and 14. The measured temperature is 32
The response times obtained under the same conditions as in Example 11 except for the temperature change were 65 and 32 μsec, respectively, indicating 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 1 or a liquid crystal composition containing at least one kind of this optically active compound as a component, the spontaneous polarization is large. Therefore, it is possible to provide not only a high-speed response when used as a display element, but also a material system that exhibits a chiral smectic phase over a wide temperature range and an optical switching element that exhibits a high-speed response.

Claims (1)

[Claims] 1. The following general formula I: ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) [However, the ring ▲There are mathematical formulas, chemical formulas, tables, etc.▼a, ▲
There are mathematical formulas, chemical formulas, tables, etc.▼b, or ▲mathematical formulas,
There are chemical formulas, tables, etc. ▼ At least one ring of c contains one fluorine or chlorine, and the other ring ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, W, X, Y
and Z represents fluorine or chlorine), L is -COO- group or -OCO- group, and Q is -C
OO- group or direct bond, R_1 and R_2 are an alkyl group or alkyloxy group having 4 or more carbon atoms, and at least one of R_1 or R_2 is an optically active group. active compound. 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.