JPS62148452A - Novel liquid crystal substance and liquid crystal composition - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R is 1-18C alkyl; n is 3-7; *represents optical activity). EXAMPLE:(S)-4-octylbiphenyl-4'-yl p-(4-methylhexyl)oxybenzoate. USE:A substance for liquid crystal display element. It has chemical stability, exhibits ferroelectricity and expands temperature range of chiral smectic C- phase. PREPARATION:The compound of formula I can be produced by reacting (S)-p-(4- methylhexyl)oxybenzoic acid chloride of formula II with 4-octyl-4'- hydroxybiphenyl of formula III in a solvent such as benzene in the presence of a base such as pyridine.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a novel liquid crystal compound useful as a component of a ferroelectric liquid crystal composition and having excellent chemical stability, and at least one of the liquid crystal compounds. The present invention relates to a liquid crystal composition containing seeds.

(Prior Art) In 1980, Clark and Lagerval (Applied
Physics Letters, 36, 899, 1980
) has announced a display method using the optical switching phenomenon of ferroelectric liquid crystals, which has excellent properties not found in conventional display methods using nematic liquid crystals, namely high-speed response, and is expected to be used as a next-generation display element. It is attracting attention.

Ferroelectric liquid crystal was first discovered in 1975 by R.B. Meyer et al.
In order for a liquid crystal substance to exhibit ferroelectricity, it must satisfy the following conditions.

■ It must have an asymmetric carbon atom in its molecular structure and be optically active.

(9) Must have a permanent dipole moment perpendicular to the long axis direction of the molecule.

■ It must have a chiral smectic C phase (SmC" phase).

Typical conventional ferroelectric liquid crystals are shown below in terms of their structural formula and other details.

Cr78 t −→EimH” ←→5InC−→Sm
A ←→ 工 s.

(a) is the first ferroelectric liquid crystal material discovered by Meyer et al., and (1) l is known as a compound with large spontaneous polarization. Both are thick bases and are unstable in moisture. (C) is stable in moisture, but Sm
The temperature range of the C” phase is narrow.

(Disclosure of the Invention) The present inventors have succeeded in providing a novel compound that is chemically stable and useful as a component of a ferroelectric liquid crystal composition.

The novel compound according to the present invention is a chemically stable substance, and when used as a component of a liquid crystal composition, can provide a display element with a wide operating temperature range.

That is, the compound according to the present invention is useful as a component for expanding the temperature range of the SmC'' phase in a liquid crystal composition.

The present invention will be explained in detail below.

The novel compound according to the present invention has the general formula (11 (wherein R is an alkyl group having 1 to 18 carbon atoms, n represents an integer of 3 to 7, and the reference numeral indicates an optically active atom. It is a liquid crystalline compound represented by

The compounds according to the present invention can be produced by the synthetic route shown by the following scheme.

The symbols (1) to (x1) shown in the diagram are all assigned to the corresponding compounds in the examples.

EXAMPLES Below, the compounds according to the present invention, their production examples, and usage examples will be specifically explained with reference to Examples.

Example 1 (S) -4-octylbiphenyl-4'-yl p-(
Synthesis of 4-methylhexyl)oxybenzoate (x) (a) Synthesis of 4-acetoxy-4/-cabrarylbiphenyl (1) Anhydrous aluminum chloride 1262, methylene chloride 400C
Add cabrylyl chloride 92 to the mixture of C with stirring.
2 was added dropwise, and then 80 t of 4-acetoxybiphenyl was added dropwise thereto as a methylene chloride solution at room temperature. After reacting at the same temperature for 5 hours, the reaction solution was poured into dilute hydrochloric acid. The liberated methylene chloride layer was thoroughly washed with water and dried with Glauber's salt. After distilling off the solvent, the 4-acetoxy-4/839 was recrystallized twice from ethanol.
-caprylyl biphenyl fi) was obtained.

(b) Synthesis of 4-octyl-4/-hydroquinbiphenyl (11) Add 4-acetoxy-4'-cabryl biphenyl (1) (92 t, ) ethylene glycol 450C to a reaction vessel.
C185% caustic potash 602 (dissolved in 100 cc of water) and 85% hydrazine hydrate 852 were charged, and under reflux, 3
Stir for hours. Next, the water in the reaction system is distilled off.
The temperature was raised to 0'C, and the reaction was continued at the same temperature for 4 hours. After cooling, the reaction solution was poured into dilute hydrochloric acid, and the precipitate was extracted with isopropyl ether (IPE). After thoroughly washing the IPE layer with water, it was dried with Glauber's salt. By distilling off the PE and recrystallizing the residue from ethanol, 4-octyl-4'-hydroxybiphenyl (ii) of 667 was obtained.
fc. m, 11.139~1・10°C (c)
1-4-Methylhex/rubromide (Mol.

crystal, Liq, Crystal It4237-2
-Synthesized according to the reaction example of t71984. 1), p, 7
1~72°C/23.5 mmHg) 30? ,
Anhydrous potassium carbonate, 167 and cyclohexanone 30
0CC was charged and stirred at 130-140°C for 5 hours.

The reaction solution was poured into water, and then the liberated organic layer was extracted with benzene. This benzene layer was thoroughly washed with water and then dried with sodium sulfate. The solvent was distilled off and the residue was distilled under reduced pressure (
S)-p-(4-methylhexyl)ox7benzoate methyl (iii) 37.5 ? I got it. 1), p. 13
6-137°C/0,4 mmHg(d) (S
l-p-(4-methylhexyl)oxybenzoic acid (1
In the synthesis reaction vessel of v), methyl (S)-p-(4-methylhexyl)oxybenzoate (iii) 37.5 ? , methanol 200cc, 95% caustic soda 182 (water 100cc)
(dissolved in CC) and stirred under reflux for 4 hours.

The reaction solution was poured into dilute hydrochloric acid, and the precipitate was extracted with isopropyl ether (IPE). After thoroughly washing this IPE layer with water, it was dried with Glauber's salt. After distilling off the PE, the residue was recrystallized from hexane to obtain (S)-p-(4-methylhexyl)oxybenzoic acid (iv) 34S'. m
, 1), 118-125.5°C (e) (8)
-p-(4-methylhexyl)oxybenzoic acid chloride (S) -p-(ll-methylhexyl)
Prepared 347 cc/benzoic acid and 150 cc benzene.
Thionyl chloride 357 was added dropwise while stirring under reflux.

Then, after reacting at the same temperature for 6 hours, the solvent and excess thionyl chloride were distilled off. The residue was distilled under reduced pressure (S)-
p-(4-methylhexyl)oxybenzoic acid chloride M 32.79 was obtained.

1), p, 133°C/0, 3 mmHg (f
) (S) '4-Octylbiphenyl-4'-yl p-(4-methylhexyl)oxybenzoate (×
) 4-octyl-4/-hydroxybiphenyl (li12f, benzene 30CC, H')',;
)-(4-Methylhexyl)oxybenzoic acid chloride M2? was dripped. After reacting at room temperature for 2 hours and further under reflux for 3 hours, the reaction solution was poured into water. The liberated benzene layer was thoroughly washed with water and dried with Glauber's salt.

Benzene was distilled off, and the residue was recrystallized twice from acetone to give (S)-4-octylbiphenyl-4'-yl p
-(ll-methylhexyl)oxybenzoate (phantom 1
．． I got 37.

The content of this substance was determined to be 99% by liquid chromatography.
The above was one spot in thin layer chromatography. Furthermore, according to the infrared absorption torque measurement, the characteristic values are 2800 to 3000 m-', 17 = l Ocm,
It was 1260 cm. In addition, mass spectrometry analysis revealed a molecular ion peak at 500, supporting the chemical structure of this product.

This product was placed on a Mettler hot stage FP-82, and the phase change was observed under a polarizing microscope, and the following was observed.

108 Ya125 153 Cry8 11-→SmC←--→Ch←--→Engineering SO
Examples 2 to 1 According to Example 2, various derivatives were synthesized using the same powder, and the phase transition temperatures were measured. Table 1 shows the results. [In the table, R is R in the general formula (1), thereby indicating each compound] Example 5 (S) -4-Octylbiphenyl-,1/-yl p-
(6-methyloctyl)oxybenzonyt-(xi)
Synthesis (a) (Synthesis of Si6-methyloctyl bromide (vl)) 13.89 g of powdered magnesium and 160 cc of tetrahydrofuran (purified by distillation after treatment with lithium aluminum hydride) were charged into a reaction vessel, and (S)
-2-methylbutyl bromide (Mo1.Crest,
Synthesis according to the reaction example of Li (1, Cr3'St 4837-521978 1), p, 123-124 °C)
A Grignard reagent was prepared by adding 78 f dropwise.

Separately, 1,4-dibromobutane 1237
, tetrahydrofuran (THF) 350 cc.

and Q, l mol/t of dilithium tetrachlorocuprate-THF bath solution (Li2CuC74/
18 cc of THF was charged, and the Grignard reagent mentioned above was added dropwise at 0°C or below.

After stirring for 1 hour at 0°C or lower, 1 hour at 10''C, and 1 hour at room temperature, the reaction solution was poured into dilute hydrochloric acid.The liberated organic layer was extracted with benzene, and the benzene layer was thoroughly Washed with water. After drying the benzene layer with Glauber's salt, the solvent was distilled off and the residue was distilled under reduced pressure to obtain (S)-6~methyloctyl bromide (vi)60?b, p, 1
02~114°C/27 mmHg(t)) (S
)-p-(6~methyloctyl)methyl oxybenzoate (40.3? of methyl p-hydroxybenzoate in the synthesis reaction vessel of viO,
(S)-6-methyloctyl bromide 502, anhydrous potassium carbonate 677 and cyclohexanone 350CC
and stirred at 120-125°C for 5 hours.

Next, the reaction solution was poured into water, and the liberated organic layer was extracted with ethyl ether. The ether layer was thoroughly washed with water and dried with Glauber's salt. After distilling off the solvent, the residue was distilled under reduced pressure (Sl
Methyl p(6-methyloctyl)oxybenzoate ~1i155.59 was obtained.

b, p, 169-171 °C/l, OmmHg (
C) Synthesis of (S) p (6-methyloctyl)oxybenzoic acid (vii+) Into a reaction vessel, add 549.95 methyl (S) -p -(6-methyloctyl)oxybenzoate and 209 chloride (
(Dissolved in 200 cc of water) and 300 cc of methanol were added, and the mixture was stirred under reflux for 3 hours. Pour the reaction solution into dilute hydrochloric acid,
The precipitate was extracted with benzene. After thoroughly washing the benzene layer with water, it was dried with Glauber's salt.

After distilling off the solvent, the residue was recrystallized from hexane to obtain (S
) to p-(6-methyloctyl)oxybenzoic acid (vi
ti) 43, 19 was obtained. m, 1), 126.
5-127°C (d) (Sip-(6-methyloctyl)oxybenzoic acid chloride (1x) synthesis reaction vessel (S) -p = (6-methyloctyl)oxybenzoic acid 487 and benzene 2000C) After charging, thionyl chloride +5 r was added dropwise while stirring under reflux. After reacting for 6 hours at homogeneity, benzene and excess thionyl chloride were distilled off. The residue was distilled under reduced pressure (Sl
' p-(6-methyloctyl)oxybenzoic acid chloride (ix) 18 Si' was obtained.

b, p, 151'C/0.25 mmHg (e
) (St-,+-octylbiphenyl-4'-yl p-(6-methyloctyl)oxybenzoate (xi
) into a synthesis reaction vessel, 4-octyl-1'-hydroquinobiphenyl 27, benzene 30 CC, H') syn 0.67
was charged, and while stirring, 2.21 g of (S)-p-(6-methyloctyl)oxybenzoic acid chloride was added dropwise. After reacting at room temperature for 2 hours and further under reflux for 3 hours, the reaction solution was poured into water.

The liberated benzene layer was thoroughly washed with water and then dried with Glauber's salt.

After distilling off the solvent, the residue was recrystallized twice from ethanol (
S) -4-octylbiphenyl-4'-yl p-(6
-Methyloctyl)oxybenzoate 1.89% was obtained.

The content of this substance was determined to be 99% by liquid chromatography.
The above was one spot in thin layer chromatography. In addition, according to infrared absorption peak measurement, the characteristic values are 2800 to 3000 cm-', 1730 cm-',
It was 1260 cm-'. Mass spectroscopy analysis revealed a molecular ion peak at 528, supporting the chemical structure of this product. This material was placed in a Mettler hot station FP-82, and the phase change was observed under a polarized jaw mirror, and the following was observed.

87.9 Ka 140 154.8Cryst
SmC←-→Ch SO Examples 6 to 8 Based on Example 5, various derivatives were synthesized in the same manner, and the phase transition temperatures were measured. Table 2 shows the results. [In the table,
R is R in the general formula (I) and indicates each compound] The compounds obtained in each example have an enantiotropic smc" phase in a wide temperature range,
Any of these is effective as a component for extending the temperature range of the ferroelectric liquid crystal composition.

Example 9 On the surface, t? A liquid crystal cell was assembled by sandwiching a Mylar film between two glass substrates having transparent electrodes coated with an IJ imide-based bulk polymer film and subjected to rubbing treatment. In addition, 2
The rubbing directions of the two substrates were parallel to each other, and the cell spacing was 9 μm. The compounds obtained in each example were sealed in this liquid crystal cell and slowly cooled from an isotropic liquid to a SmC'' phase.This liquid crystal cell was sandwiched between two polarizing plates, and a voltage was applied to reverse the polarity. When I did this, the display status changed.

As described above, the SmC'' phase of each compound obtained in each example exhibits ferroelectricity and can be used as an electro-optical element.

The compounds according to the present invention are chemically stable and useful as components for extending the temperature range of ferroelectric liquid crystal compositions.

Claims (1)

[Claims] 1) General formula (I) ▲There are numerical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R is an alkyl group having 1 to 18 carbon atoms,
n represents an integer of 3 to 7, and the symbol * represents an optically active atom.) A liquid crystalline compound represented by: 2) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R is an alkyl group having 1 to 18 carbon atoms,
n represents an integer of 3 to 7, and the symbol * represents an optically active atom.) A liquid crystal composition comprising at least one liquid crystal compound represented by the following.