JPH01283258A - optically active liquid crystal compound - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I [L and M are -COO- or L is -OCO- and M is -O-) W, X, Y and Z are F or Cl; m is 1 or 2; R is >=4C alkyl; at least one of C3F7OCF(CF3)- and R is optically active group]. EXAMPLE:4''-(Octyloxycarbonyl)tetrafluorophenyl 4'-(perfluoro-1-propyloxyethyl) carbonyloxy-4-biphenylcarboxylate. USE:A liquid crystal material excellent in chemical and light stability with great spontaneous polarization and a wide temperature range of chiral smectic C phase. PREPARATION:An optically active perfluoro-2-propyloxypropionic acid is reacted with a hydroxycarboxylic acid compound in the presence of an acid catalyst to provide a compound expressed by formula IV, which is then reacted with a compound expressed by formula Il in the presence of pyridine, etc., according to the reaction formula to afford the aimed compound expressed by formula I.

Description

[Detailed description of the invention] [Field for sedentary work] The present invention relates to thin, optically active liquid crystal compounds.

[Conventional technology]

Currently, the display systems of liquid crystal display elements that are widely used in practical use are twisted nematic (TN) and dynamic scattering (DS). These are displays using nematic liquid crystal cells that are made entirely of 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. can be given. This is one of the factors that limits the range of applications of nematic liquid crystal cells. On the other hand, 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., Mayer (R.B.

[Shurnard de Physique (J. Phys.), No. 36]
Vol. L69 (1975)], which is 4-(4'-
n-Decyloxybensyriteneamino)-2-methylbutersi/namate (DOBAMBC) is a typical Schiff-based compound that exhibits ferromagnetic properties in a specific optically active state, e.g., the Caicyl Smectic C phase.
The t% image indicates that it exhibits torturous properties. After that, N.
A, Clark (N, A, C1ark) et al. [Applied Fixtures Letters (Appl, Phyθ, Lθ
11. ) Vol. 36, p. 899 (1980)] discovered a high-speed response on the order of microseconds in the thin film cell of DOBAMBC, and this served as an opportunity for strong electrospinning liquid crystals to improve their high-speed response and memory properties. Take advantage of
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 former printer heads, optical Fourier transform elements, and light pulp. In a ferroelectric liquid crystal cell, the use of a material with a higher permittivity and a larger spontaneous polarization is advantageous because the cell can be driven in a continuous manner, so the development of a material with a larger spontaneous polarization is desired. In addition, in practical terms, the liquid crystal compound itself is stable, 1 and furthermore, it is forced to induce i! over a wide temperature range centered on chamber m! It is necessary to show one's sexuality.

[Problem that the invention seeks to solve]

However, Schiff base-type compounds such as DOBAMBC are at a critical point in terms of stability against water and light, and their pervasive coercive properties are on the extreme side of the 1140°C indoor temperature range, making them difficult to put into practical use. It wasn't suitable. Therefore,
There are strong expectations for the realization of material threads that are physically and chemically stable and have large spontaneous polarization as ferroelectric liquid crystal cells.

An object of the present invention is to obtain a novel liquid crystal compound which has excellent chemical stability and five-element stability, has a large spontaneous polarization, and has a wide range of chiral smectic C phase. The present invention also aims to provide a display element having high-speed response using this novel optically active liquid crystal compound or a liquid crystal composition containing the same.

[Means to solve the problem of confusion]

To summarize the present invention, the present invention relates to an optically active liquid crystal compound, which is a compound represented by the following general formula l (wherein L and M are -coo- group, or L is -OC〇- group, M is 10-group, W, C3F70CF (CF3
At least one of the URs is an optically active group) The compound of general formula 1 has a trifluoromethyl group or a carbonyl group tangentially bonded to the asymmetric carbon, and also has a Because it contains fluorine or fluorine and chlorine in the direction, it is effective in increasing electrical polarization.
It is expected that there will be a rotational relationship. In addition, the central skeleton contains a biphenylcarboxylic acid ester or benzoic acid phenyl ester structure9, and since a long-chain alkyl group is present at the end of the molecule, it itself exhibits liquid crystallinity. Furthermore, since it contains multiple fluorine compounds, it has a lower viscosity than non-fluorinated yarn compounds, and it is expected that a smectic C phase will develop at low temperatures, resulting in a high-speed response when used as a display element. You can expect sex. Note that the alkyl group of the group R preferably has 4 to 18 carbon atoms.

The compound of general formula 1 of the present invention can be synthesized, for example, according to the following method.

(…a) (river b)
(Kawari↑ROHj ROHj ROH ↓KOH↓KOH↓KOH (na) (mb)
(Otori C3FyOCF (CF3) COOH+
Hoshinta coon→ C3F'700F'(CF,)C
OOQCOOH (Iv) → C3F70CF (CF3)
COOaCOC2C3F70CF(CF3)COOH+
HO&TSOH→ C3F70CF(CF3)cOOOQ
OH(V)1'i' Y 4-hydroxy-tetrafluoro-(lad, 2-
Chlorotrifluoro- or U2,6-dichlorodifluorobenzoic alkyl esters (llb) I-J4-hydroxy-tetrafluorobenzoic acid, etc., and this compound 1l-
IJ, M, Hartyal (J, M, Birchall)
In addition, the Journal of Chemistry (J, C
hem, 8oc, 1971, p. 1646] by reacting it with an alcohol in the presence of an acid catalyst. Also 4-hydroxy-6
-Chlorotetofluoro or H3゜5-dichlorodifluorobenzentanyl alkyl esters (4-hydroxy-6-chlorotetrafluorobenzonitrile or 6,5
-Dichlorotrifluorobenzonitrile [Can be produced using pencchlorobe/zonitrile according to the report by Ishikawa et al. (Akio Takaoka, Nobuo Ishikawa, et al., Journal of the Chemical Society of Japan, 1985, p. 2155)] All phases described by Bharteyal et al. It can be manufactured in the same way.

Next, 4-alkyloxy-tetrafluoro-(weighed,
2-Chlorotrifluoro- and 2,6-dichlorodifluorobenzoic acids (till) According to the above report by Harteyal et al. The nitrile is reacted with potassium alkoxide in an aprotic polar bath medium to introduce an alkyloxy group at the 4-position by a nucleophilic substitution reaction, and then heated with the total potassium hydroxide water bath solution to hydrolyze the cyano group. (1) and (1b) can be obtained. Also, for the preparation of (1), using 6-chlorotetrafluoro- or 3.5-dichlorotrifluorobenzonitrile, the above (I
It can be manufactured in the same manner as in case b).

Next, optically active perfluoro-2-propyloquine globionic acid was reacted with a hydroxycarboxylic acid compound in the presence of an acid catalyst to obtain a carboxylic acid compound (lv) into which a perfluoro-2-propyloxy ether group was introduced. can get.

Furthermore, after reacting 4'-dihydroxybiphenyl with perfluoro-2-propyloxypropionic acid in the presence of a completely dispersed catalyst, the alkali 'J'0]' bath part was completely isolated. Hydroxy-4'-(perfluoro-
1-propyloxyether)carbonyloxybiphenyl (v) is obtained.

Finally, K(IV)(DW) is reacted with the acid chloride of (11) and (V)'(r) in the presence of a basic compound such as pyridine, and the general formula ( All of the compounds shown in 1) can be produced.

In addition, when oxyglobionic acid is used for racemic perfluoro-2-pObi, all compounds of the general formula CM) in which the alkyl group R of the compound is optically active are used.
1) Compound km! ! ! can be built.

〔Example〕

Hereinafter, all examples of unfired BAs will be explained in detail, but the scope of application of the present invention is not limited to these examples.

Example 1 [In general formula 1, L=M=COO, W=X=Y=Z
= F, m = 2% R = (compound represented by 4HH) (a) 4'-hydroxy-4-biphenylcarboxylic acid 5. Of b jt Scientifically active perfluoro-2-propyloxypropion W6.6t, p- 1-luenesulfone g 1.4 f and toluene 15 (ld') were heated to reflux and reacted for 300 hours while removing the water produced by Teen Stark water separation a to the outside of the thread, and after cooling, extracted with toluene by pouring all the water into the mixture. , was extracted with a dilute aqueous sodium carbonate solution, and the water bath was acidified with hydrochloric acid to produce a solid.This was recrystallized from total ethanol to give 4'-(perfluoro-1-propyloxyethyl)carbonyloxy-4-biphenyl. Carboxylic acid (IV.

However, m=2) was obtained.

(cut 4-hydroxytetrafluorobenzoic acid hydrate 2
5t, 1-octatool 152, p-toluenesulfone [1,4f & toluene 650d k After reacting in the same manner as (a), extracting with dilute sodium hydroxide water bath solution,
This water! [: When the mixture was made 1!12 with hydrochloric acid, an oily substance was produced. All of this was extracted with ether, washed with water, dried over anhydrous magnesium sulfate, distilled off the ether, and subjected to silica gel column chromatography using hexane as a solvent.
4-Hydroxytetrafluorobenzooctyl ester (la, R=CsHxt)' was obtained.

(C) 4'-(perfluoro-1 obtained in (a)
-propyloxy-diethyl)carbonyloxy-4-biphenylcarboxylic acid 1.52 f to thionyl chloride 1〇-
After heating for 2 hours, thionyl chloride was removed under reduced pressure, and this was made into a toluene bath solution, which was gradually added dropwise to a solution of pyridine 50vt of benzoic acid ester α81f obtained in (1)) at 55-65°C. The reaction was carried out for 5 hours, and after being incubated for one night, the water was washed with an aqueous sodium sulfur solution and then with water, dried over anhydrous magnesium sulfate, and the solvent was removed. It was purified by microchromatography and further recrystallized with heptane to obtain the optically active compound 'flJ:4'-(perfluoro-1-probyloxyethylnocarbonyloxy-4-biphenylcarbonyl Tetrafluorophenyl ester was obtained.

This compound 't-x* was sealed in a cell with transparent electrodes with a gap of about 3 μm and observed under a polarizing microscope.
It showed a S corrosion phase in the range of 18°C. In this OjA degree range, when an electric field of ±5 V and IHz was applied, domain inversion was observed as the polarity of the electric field was reversed. Other inversion degrees are as shown in Table 1 below along with other examples. Incidentally, Cry indicates a crystalline state, SC indicates a chiral smectic C phase, 8A indicates a smectic A phase, and C indicates an isotropic liquid phase. Also, / indicates that the phase exists.

Moreover, this compound has l! between all electrodes! When it was sealed in a cell with an A40 μm transparent electrode and the spontaneous polarization was measured using the triangular wave method,
The value was 152 n'C/crn2 0 Example 2 Q) ■, ■ ■Y=F, Z=Ct; ■Y=Z=C2 Example 1 (
Optically active compound ■: 4'-(perfluoro-1-propyloxy ether 9 carbonyloxy-4-biphenyl carbon &-4”
-(ySyloxycarbonyl)tetrafluorophenyl ester was obtained. 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 115 nc7'ttr? I failed.

Also, instead of 4-hydroxytetrafluorobenzoic acid, 2-chloro-5,5, rhotrifluoro- or 2,6-
Optically active liquid crystal compound (1): 4'-(perfluoro-1-propyloxyethene A/)carbonyloxy-4 was prepared in the same manner as in Example 1 except that dichloro-5,5-difluoro-4-hydroxybenzoic acid was used. −biphenylcarvone [
-4'-octyloxycarbonyl-6''-chloro-2
:5:'6''-trifluorophenyl ester and h■:
4'-(perfluoro-1-propyloxyether)carbonyloxy-4-biphenylcarboxylic acid-4''-octyloxycarbonyl-3';5''-dichloro-2
','6''-difluorophenyl ester was obtained.

Furthermore, 4-hydroxytetrafluorobenzoic acid (D group bO
Optically active compound ■: 4 in the same manner as in Example 1, except that 1-hexanol was used instead of YCS-chloro-2,5,6-toIJ fluorobenzoate.
'-(perfluoro-1-propyloxyether)carbonyloxy-4-biphenylcarboxylic acid-4#-hexyloxycarbonyl-21-chloro-3';5':
6''-trifluorophenyl ester was obtained.The phase transition temperatures of these compounds are as shown in Table 1. Example 6 (, QW=F, X=C1: ($W=X=C1 nitrogen Metal potassium 2.Of 1-octatool 50- in atmosphere
Then, heat to make a homogeneous solution, and make a solution of pentafluorobenzonitrile 961 and N,N-dimethylacetamide 80#! /! were added and reacted by heating at 85 to 94°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, and add 20% potassium hydroxide water bath solution 1801Rt to the residue.
was heated under reflux for 4 hours, and after cooling, extracted with toluene to remove unreacted octyl alcohol/l/f.
Add all the acid and extract with ether, distill off the ether, and recrystallize the residue from butane to obtain 4-octyloxytetrafluorobenzoin (R (jab R= Cl1H17)
I got k.

゛Also, instead of pentafluorobenzonitrile, 2-
Chlorotetrafluoro or fi2.6-cyclotrifluoropenzonitrile was added to 1 instead of 1-octatool.
-4-decyloxy-2-chloro-3,5,rotrifluoro-(
lt+, R=C10H21, w=F, x=cz) and 4
-decyloxy-2,6-dichloro-6,5-difluorobenzoic acid (lb, R=Cl0H21, W=X=
ct) 2 obtained.

Furthermore, 4-octyloxy-6,5-cyclo-2,6-difluoroamne Incense m(t, R= (4H17,
W = X = CL) '(+l' got 04.4
'-dihydroxypiphenyl 219 and p-toluenesulfonic acid 1.5 t 'i Toluene 650- A solution of optically active perfluoro-2-propyloxyprobionic acid 332 in toluene 300 was gradually dissolved over 6 hours. Water dripping to catch insects? The mixture was reacted for 10 hours while being removed using a Teen Stark water separator, then cooled in a vacuum cleaner for 11 hours, extracted with toluene, extracted 5 times with dilute sodium hydroxide bath solution, and acidified with total hydrochloric acid. The resulting solid was extracted with ether, washed with water, dried over anhydrous (magnesium 11E), the ether was distilled off and recrystallized with ethanol, and 4-hydroxy-4'-(perfluoro-
1-propyloxyethyl)carbonyloxybiphenyl (V)' was obtained.

4-octyloxynato2fluorobenzoic acid α81f'
i Heated with 5-thionyl chloride for 2 hours, distilled off the thionyl chloride, and dissolved the residue in toluene 10- to give 4'-(perfluoro-1-propyloxyethyl)carbonyloxy-4-hydroxypiphenyl 1. .25 f was gradually added to a solution of pyridine 30, and reacted at 61-72°C for 10 hours. After standing overnight, it was poured into water and extracted with toluene. The toluene solution was soaked in a 1% potassium hydroxide water bath, then The residue obtained by washing with water and drying over anhydrous magnesium sulfate and distilling off the solvent under reduced pressure was purified by silica gel column chromatography using hexane-toluene as a solvent, and further recrystallized with heptane. Optically active compound ■: 4
-Octyloxytetrafluorobenzoic acid-4''-(perfluoro-1-propyloxyethyl)carbonyloxy-4'-biphenyl ester was obtained.

4-decyloxy-2-chloro-5,5,rotrifluoro-,4-decyloxy-2,6-dichloro-6,5
-difluoro- or 4-octyloxy-3,5-dichloro-2,6-difluorobenzoin was prepared in the same manner as above except that the optically active compound: 4-7'siloxy-2-chloro-3,5,6 -Trifluorobenzoic acid-
4″~(perfluoro-1-propyloxyethyl)carbonyloxy-4′-biphenyl ester, original active compound vl) ■: 4-Tesyloxy-2,6-dichloro-
6,5-difluorobenzoic acid-4″-(perfluoro-
1-propyloxyether)carbonyloxy-4'-
Biphenyl ester &U"lt science fts f+ compound ■: 4-octyloxy-3,5-dichloro-2-
2,6-difluorobenzoate-4”-(perfluoro-
1-propyloxyethyl)carbonyloxy-4'-
Obtained biphenyl ester.

The phase transition temperatures of these compounds are shown in Table 1. Moreover, the value of spontaneous polarization created in the same manner as in Example 1 is 0.
127 and 0185 nc/cWP.

Example 4 An optically active compound [phase] 4'-(perfluoro-1- Probyloxyethernocarbonyloxy-4-biphenylcarboxylic acid-4''-(1-methylhegyloxycarboel)teto2fluorophenyl ester was obtained. The phase transition temperature of this compound is as shown in Table 1. Furthermore, the value of spontaneous polarization created in the same manner as in Example 1 was 79 nC/-.

Example 5 Substitute 9 for 4'-hydroxy-4-biphenylcarboxylic acid
Example 1 except that 4-hydroxybenzoic acid [1-
In the same manner as in a), 4-(perfluoro-1-propyloxyether)carbonyloxybenzoic@(N, but m
=1) was obtained.

This acid chloride and & 4-hydroxy-2-chloro-
Optically active compound ■: 4-[
4'-(perfluoro-1-globyloxyethylbenzoyloxy)-2-chloro-6,
5゜Rotrifluorobenzoic acid octyl ester and optically active compound@: 4-[4'-(perfluoro-1-globyloxyethylcarbonyloxy)be/zo4yloxy]-tetrafluorobenzoic acid hexyl ester km
is.

The phase transition temperatures of these compounds are shown in Table 1. Note that () indicates that the phase is monotropic.

Example 6 For the optically active compound 010 in Example 5, 4′-(2-methylbutyl)-4-biphenylcarboxylic acid-4″-octyloxyphenyl ester having the following structural formula, which is a non-chiral smectic liquid crystal, was used. 40N
Sumire HVS &? J 4'-Oythyloxy-4-biphenylcarbon[-4''-nonyloxyphenyl ester 50% t m k 1n was combined to completely prepare a liquid crystal composition vlJ.

C2H5CH(CH3)CH2CpaD-COOQOC,
HI3 This liquid crystal composition exhibited an SCG phase in the range of 23 to 62°C. Also, the value of spontaneous polarization is 35 nC/ctn"
I failed. In this way, by mixing liquid crystal compounds with different structures, it is possible to obtain a liquid crystal composition that exhibits chiral smectic CG crystals in a wider temperature range than when used alone and in the vicinity of the brocade.

〔Effect of the invention〕

As described above, according to the present invention, by using the optically active liquid crystal compound represented by the general formula 1, the temperature range of the di-chiral smectic C liquid crystal phase is lowered compared to conventional non-halogen yarn materials. , it is possible to provide a liquid crystal element that exhibits chiral smectic C811 on the side closer to room temperature and has large spontaneous polarization.

Claims (1)

[Claims] 1. The following general formula I: ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] (In the formula, L and M are -COO- groups, or L is -OCO-
In the group, M is -O- group, W, X, Y and Z are fluorine or chlorine, m is a number of 1 or 2, R is an alkyl group having 4 or more carbon atoms, and of the group C_3F_7OCF (CF_3) or R An optically active liquid crystal compound, at least one of which is an optically active group.