JPS6210045A - Liquid crystal compound and liquid crystal composition - Google Patents

Abstract

NEW MATERIAL:A liquid crystal compound expressed by formula I {X is H or halogen; Y and Z are R-, formula II, III, etc.; [R represents 6-18C alkyl, and at least one of alkyl groups is optically active alkyl expressed by formula IV (n is an integer 0-3; m is 1 or 2; * is asymmetric carbon atom) including the asymmetric carbon atom}. EXAMPLE:(+)-4'-(2''-Methylbutyloxyphenyl) 6-octyloxynaphthalene-2-carboxylate. USE:Useful as one component of liquid crystal compositions capable of providing liquid crystal compositions assuming SC* phase at about room temperature by mixing with the compound and suitable for enlarging the upper limit of temperature range of the SC* phase. PREPARATION:For example, 2,6-hydroxynaphthalenecarboxylic acid expressed by formula V is alkylated and then reacted with an alcohol to afford the aimed compound expressed by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a novel optically active liquid crystal compound and a liquid crystal composition containing the liquid crystal.

(Conventional technology) Currently, various liquid crystal display elements are in practical use.

Among them, TN (Twi
The s t -ed Nematic) type display system has excellent performance such as extremely low power consumption, and is widely used. However, this display method has the drawback of slow response speed.

Recent advances in industrial technology have strongly demanded high-speed response from liquid crystal display elements, and in response to such demands, various attempts have been made to improve liquid crystal materials.

A display device (applied φ
Physix Fist Letter (Appl PhysLeft)
), 56.899 (I980)) have been proposed.

This ferroelectric liquid crystal is said to belong to a chiral smectic C phase (hereinafter abbreviated as S-) or a chiral smectic H phase (hereinafter abbreviated as 8 doors) in terms of its liquid crystal structure.

(Problems to be Solved by the Invention) Typical known ferroelectric liquid crystals are shown in Table 1.

However, these compounds are undesirable as display elements because they undergo isomerization in a short period of time when exposed to light, are unstable to moisture, and are unstable in that they undergo hydrolysis and no longer exhibit a liquid crystal phase. An object of the present invention is to provide a ferroelectric liquid crystal having photochemical and chemical stability free of such unstable elements and a composition containing the crystal.

(Means for Solving the Problems) In order to achieve the above-mentioned problems, the present inventors synthesized and studied liquid crystal substances containing many optically active groups, and as a result, they arrived at the present invention.

That is, the present invention relates to the general formula (I) (wherein, X is a hydrogen atom or a halogen atom, (where W is a hydrogen atom or a halogen atom, -(ca2)n represents an alkyl group, and at least one alkyl group contains an asymmetric carbon atom
D-(cHz)m-cH3 (n is an integer from 0 to 3, where m
is an integer of 1 or 2 and the stripes represent an asymmetric carbon atom) is an optically active alkyl group represented by)) and a liquid crystal compound represented by It is a composition.

The compounds of the present invention are typically synthesized by the following synthetic route.

(xXy, z are the same as above) In other words, after alkylating 2,6-hydroxynaphthalenecarboxylic acid or its halogen-substituted product (If) and esterifying it to a compound (I0 or (5)), Synthesized by reacting with alcohols, phenols, or carboxylic acids.

More specifically, from the compound (II) above, (I[)'
! Alternatively, the liquid crystal compound (I) can be obtained by manufacturing the compound (5) and using these as raw materials.

(I) or (
For producing the compound 5), for example, 6-alkyloxynaphthalene-2-carboxylic acids, 4-alkyloxyphenols, 4-alkyloxybenzoic acids, 4-hydroxybenzoic acid-41-alkyloxyphenyl esters, 4-alkyloxypiphenyl-4-carboxylic acids are used, and these compounds can be produced by known methods.

For example, ■6-alkyloxynaphthalene-2-force/
I/Honic acids are produced by a method of reacting 6-hydroxynaphthalene-2-carboxylic acids with alkyl bromides in the presence of potassium hydroxide in ethanol (Journal Op.
Chemical Nsaietei (J.

C! hem, 5oc), 195467B), ■4
- Alkyloxyphenols can be prepared by reacting hydroquinone with alkyl bromide in ethanol in the presence of potassium hydroxide (Journal of the American
Chemical science (, r, Am, chem, so
c,).

298 (I932)), ■ 4-Alkyloxybenzoic acids, method of alkylating 4-hydroxybenzoic acid (Journal Op Chemical Society (
J, C! hem, Soc,), 19351874)
, ■ 4-Alkyloxybiphenyl-41-carboxylic acids are alkylated with 4-hydroxybiphenyl-41-carboxylic acid (Journal of the Chemical Society (J, Chem, Soc, 1955.1)
412), and ■4-hydroxybenzoic acid-earkyloxyphenyl esters can be produced by a method such as reacting 4-alkyloxyphenol and hydroxybenzoic acid in toluene in the presence of concentrated sulfuric acid and boric acid. I can do it.

Many of the compounds of the present invention exhibit an SC'' phase, and some are characterized by a relatively low temperature range of approximately 45-70°C.

Therefore, by mixing these compounds, it is suitable to obtain a liquid crystal composition exhibiting an S-phase at around room temperature.

In addition, some compounds exhibit S-
Since it exhibits a phase, it is suitable for expanding the upper limit of the temperature range of the sa'' phase of a liquid crystal composition.

The liquid crystal composition of the present invention may be composed of one or more compounds of the general formula (I), or may be composed of a liquid crystal composition that exhibits an S-phase at room temperature by mixing the compound of the general formula (I) with other smectic liquid crystals. It can also be used to construct objects, all of which exhibit ferroelectricity.

Furthermore, if a compound that does not exhibit an S-phase in the general formula (I) is used in combination with a compound that exhibits an S-phase as a so-called liquid crystal compound, similar effects can be expected as a liquid crystal composition.

(Example) Hereinafter, the present invention will be specifically explained and explained with reference to Examples. .

The properties of the liquid crystal compounds and liquid crystal compositions produced in Examples are shown in the table.

In these tables, C is a crystalline phase, SA is a smectic A phase,
? is the chiral smectic C phase, Ch is the cholesteric (chiral nematic) phase, and ■ is the isotropic liquid and SX.
represents a smectic phase of unknown origin, the * symbol for each phase and the number to the right of it indicate the transition temperature from that phase to the phase on the right, and the - symbol means that the phase is not indicated. Note that values within 0 are monotropic phase transition temperatures.

Example 1 Production of 4-optically active alkyloxyphenyl-6-alkoxynaphthalene-2-carboxylic acid ester (g)-! -(2-methylbutyloxy)phenyl-
Production example 6 of 6-octyloxynaphthalene-2-carboxylic acid ester (compound No. 2 in Table 2) - n-octyloxynaphthalene-2-carboxylic acid 182, (tho)-4-(2'-methyl butyloxy)phenol 1.1S',N,N-dicyclohexylcarbodiimide (hereinafter abbreviated as DCC) 1.2S' and 4-pyrrolidinopyridine (hereinafter abbreviated as PRLPY)5
0rn9 in 50 m/methylene chloride and 15 m at room temperature.
I left it for a while. After the by-produced N,N'-dicyclohexylurea was separated by P, the organic layer was washed with 5% hydrochloric acid, an aqueous solution of 5-thiodium hydroxide, and water in this order, and dried over anhydrous magnesium sulfate. After methylene chloride was distilled off, the residue was purified using silica gel column chromatography using benzene as the eluent. The obtained crystals were further recrystallized twice from ethanol to obtain colorless needle crystals of 1.52 (t)-4'-()'-methylbutyloxy)phenyl-6-octyloxynaphthalene. -2-
A carboxylic acid ester was obtained. The yield of 59% and the phase transition temperature are shown in Table 2. Various 4-optically active alkyloxyphenyl-6-flucoxynaphthalene-2-carboxylic acid esters were obtained by similar reaction operations. Table 2 shows the phase transition temperatures of these compounds.

Table 2 Example 2 Production of 4'-alkoxyphenyl-6-optically active alkyloxynaphthalene-2-carboxylic acid esters 4'-decyloxyphenyl-6-1-2-methylbutyloxy)naphthalene-2-carboxylic acid Esters (Table 3
Production example 6 of (compound No. 11) (((t)-2-methylbutyloxy)naphthalene-
2-carboxylic acid toy 4-4'decyloxyphenol 1.01i', DCC800? '19 and PRL
The mixture of PY 201n9 was placed in 30 mA' methylene chloride and left at room temperature for 4 hours. After the by-produced N,N'-dicyclohexylurea was filtered off, the organic layer was washed in this order with 5% hydrochloric acid, an aqueous solution of pentate sodium hydroxide, and water, and dried over anhydrous magnesium sulfate. After methylene chloride was distilled off, the residue was purified using silica gel column chromatography using benzene as an eluent. Further, the obtained crystals were recrystallized twice from ethanol to obtain the desired colorless needle crystals of 1.12, 4'-decyloxyphenyl-6.
-((-1-)-2-methylbutyloxy)naphthalene-2 carboxylic acid ester was obtained. The yield of 58% and the phase transition temperature are shown in Table 3. Various 41-alkoxyphenyl-6-optically active alkyloxy)naphthalene-2-carboxylic acid esters were obtained by the same reaction procedure.

Table 3 shows the phase transition temperatures of these compounds.

Table 3 Example 6 Production of 4-(6'-alkyloxy-2-naphthoyloxy)benzoic acid l-optically active alkyloxyphenyl ester and its substituent derivatives 3-chloro-4-(6-
Process for producing adophaciloxy-2-naphthoyloxy)benzoic acid 4-((-1-)-2-methylbutyloxy)phenyl ester (compound No. 20 in Table 4) 6-Titradecyloxynaphnale -2-carboxylic acid 5
501719.6-chloro-4-hydroxybenzoic acid-
4'-((+)-2'-methylbutyloxy)phenyl ester 500 Tn9, DCo 300 mg, PR
LPY 20 rn9 was reacted in 50 ml of methylene chloride for 20 hours at room temperature.

After filtering off the by-produced N,N'-dicyclohexyl trichloride, the organic layer was washed with 5% hydrochloric acid, an aqueous 5q6 sodium hydroxide solution, and water in this order, and dried over anhydrous magnesium sulfate.

After distilling off methylene chloride, the residue was purified using silica gel column chromatography using benzene as an eluent. Further, the obtained crystals were recrystallized from ethanol-ethyl acetate to obtain the desired colorless needle crystals of 600 m9.
-Chloro-4-(6'-tetradecyloxy-2-naphthoyloxy)benzoic acid ni<(t)-2-methylbutyloxy)phenyl ester was obtained. The yield of 60% and the phase transition temperature are shown in Table 4. Various 4-(6'-alkyloxy-2-naphthoyloxy)benzoic acid 4''-optically active alkyloxyphenyl esters and their halogen substituent derivatives were produced by similar reaction operations. Phase transition temperature of these compounds are shown in Table 4.

Table 4 Example 4 Optically active alkyl-6-alkyloxynaphthalene-2
-Production of carboxylic acid ester (t)-2-methylbutyl-6-octyloxynaphthalene-2-carboxylic acid ester (compound number 2 in Table 5)
Production example 6-octyloxynaphthalene-2-carboxylic acid 2F,
5 m/ml of thionyl chloride was heated under reflux in 50 mJ of toluene for 5 hours. Toluene and excess thionyl chloride were distilled off under reduced pressure. Dissolve the residue in 20 ml of toluene and add 12
of (→-2-methylbutanol and 10 m/p of pyridine solution and stirred at room temperature for 10 hours. The reaction mixture was
% hydrochloric acid, 10% aqueous sodium hydroxide solution, and water in this order. The organic layer was dried over anhydrous magnesium sulfate.

After distilling off toluene, the residual oil was purified using silica gel column chromatography.

Dissolve the separated oil in 5 ml of n-hexane at -20°C.
The desired (t)-2-methylbutyl-6-octyloxynaphthalene-2-carboxylic acid ester was obtained as colorless plate-like crystals of 1.21.

Yield: 49 cm The phase transition temperature of this product is shown in Table 5.

When carrying out the above operation, various optically active alkyl-6-alkyloxynaphthalenes can be prepared by using various optically active substances in place of (he)-2-methylbutanol.
A 2-carboxylic acid ester could be obtained.

Table 5 shows the phase transition temperatures of some of the compounds.

Table 5 Table 5 (continued) Example 5 Production of 4-(6'-alkyloxy-2'-nando,yloxy)benzoic acid optically active alkyl ester 4-(6'-octyloxy-2'=naphthoyloxy) Benzoic acid-(+)-2″-methylbutyl ester (
Production Example 4 of Compound No. 50 in Table 6 - Hydroxybenzoic acid 201 and (-)-2-methylbutanol 20
P.) Add 2 ml of concentrated sulfuric acid to the stirred 300 ml of toluene.
Carefully add M, and then add 1 while distilling off the by-product water.
Heating and refluxing were performed for 5 hours. After cooling, the reaction mixture was washed with water, 5% aqueous sodium carbonate solution, and water in this order. After drying over anhydrous magnesium sulfate, toluene and excess (→
-2-Methylbutanol is distilled off and the desired 4-hydroxybenzoic acid (+)-2-methylbutyl ester 31y
I got -.

Then, this 4-hydroxybenzoic acid -(+)-2'-
Methyl butyl ester 700rn9.6-octyloxynaphthalene-2-carboxylic acid 1.0%, DCC700
mg, PRLPY 20rn9 was dissolved in 30rrLl of methylene chloride and left at room temperature for 10 hours.

After filtering off the by-produced N,N'-dicyclohexylurea,
(5% hydrochloric acid, 5% hydroxide) IJum aqueous solution,
It was washed successively with water and dried using anhydrous magnesium sulfate. After distilling off methylene chloride, the residue was purified using silica gel column chromatography using benzene as an eluent. Furthermore, the obtained crystals were recrystallized from ethanol.1.
The target 4-(6'
-Octyloxy-2'-naphthoyloxy)benzoic acid-(+)-2''-methylbutyl ester was obtained. Yield: 6
7%, and the phase transition temperature is shown in Table 6.

Various 4-(6'-alkyloxy-2'-naphthoyloxy)benzoic acid (optically active alkyl) esters were obtained using various 4-hydroxybenzoic acid-optically active alkyl esters for esterification.

Table 6 shows the phase transition temperatures of these compounds.

Example 6 6-(4'-alkyloxybenzoyloxy)naphthalene-2-carboxylic acid (optically active alkyl) ester and 5-halogeno-6-(4'-alkyloxybenzoyloxy)naphthalene-2-6-(4 '-tetradecyloxypenzoyloxy)naphthalene-2-carboxylic acid = ((+)-2''-methylbutyl) ester (Table 7
Preparation Example 6 of Compound No. 70) - Hydroxinaphthalene-2-carboxylic acid 5.0? ,
(-1-2-methylbutanol 10? and concentrated sulfuric acid 1 ml
The mixture was heated and refluxed in 200 ml of toluene for 15 hours while distilling off water as a by-product.

After cooling, the reaction mixture was mixed with water, 5% aqueous sodium carbonate solution,
It was washed successively with water and dried over anhydrous magnesium sulfate. After distilling off toluene and excess (-)-2-methylbutanol, the residue was diluted with benzene-ethyl acetate (I5: 1 v
/v) was used as an eluent and purified by silica gel column chromatography to obtain 4.5 Pi of the desired 6-hydroxynaphthalene-2-carboxylic acid-(+)-2-methylbutyl ester.

Yield 66%, melting point 84-85°C Next, 400 mg of this 6-hydroxynaphthalene-2-carboxylic acid-(+)-2-methylbutyl ester, 500rn9 of tetradecyloxybenzoic acid, D CC32
0■ and PRLPY10■ were reacted in 301 nl of methyl chloride at room temperature for 10 hours.

After filtering off the by-produced N,N'-dicyclohexylurea,
(5% hydrochloric acid, 5% hydroxide) IJum aqueous solution,
It was washed successively with water and dried using anhydrous magnesium sulfate. After distilling off methylene chloride, the residue was purified using silica gel column chromatography using benzene as an eluent. Furthermore, the obtained crystals were recrystallized from ethanol.
50 mg of the desired 6-(tetradecylokidipenzoyloxy)naphthalene-2- as colorless needle crystals.
Carboxylic acid-((+)-2''-methylbutyl) ester was obtained. Yield: 51% Phase transition temperature is shown in Table 7.

Various 6-(4'-alkyloxybenzoyloxy)naphthalene-2-power/I/
A bonic acid (optically active alkyl) ester was obtained. Table 7 shows the phase transition temperatures of these compounds.

In addition, in esterification, 6-hydroxynaphthalene-2
- instead of carboxylic acid optically active alkyl ester, 5
- producing 5-halogeno-6-(4'-alkyloxybenzoyloxy)naphthalene-2-carboxylic acid (optically active alkyl) ester using halogeno-6-hydroxynaphthalene-2-carboxylic acid optically active alkyl ester; Those compounds (compound numbers 74 and 75)
Table 7 shows the phase transition temperature of .

Example 7 6-(4″-alkyloxybiphenyl-4′-carbonyloxy)naphthalene-2-carboxylic acid (optically active alkyl) ester and 5-halogeno-6-(4″-
alkyloxybiphenyl-4'-carbonyloxy)
Production of naphthalene-2-carboxylic acid (optically active alkyl) ester υ 5-chloro-6-(4"-octyloxybiphenyl-
4′-carbonyloxy)naphthalene-2-carboxylic acid-((+)-2′″-methylbutyl) ester (Table 8
In the figure, a method for producing compound No. 77 is shown.

6.51 of 5-chloro-6-hydroxynaphthalene-2-carboxylic acid, 151 of (-)-2-methylbutanol and 1 ml of concentrated sulfuric acid were heated in 200 ml of toluene for 10 hours while distilling off the by-product water. It refluxed.

After cooling, the reaction mixture was mixed with water, 5% aqueous sodium carbonate solution,
It was washed successively with water and dried over anhydrous magnesium sulfate.

After distilling off toluene and excess (-)-2-methylbutanol, the residue was dissolved in benzene-ethyl acetate (I5: lv/v).
The product was purified by silica gel column chromatography using as an eluent to obtain 6.8y of the desired 5-chloro-6-hydroxynaphthalene-2-carboxylic acid-(+)-2-methylbutyl ester. Yield 80% Melting point 108℃
Next, this 5-chloro-6-hydroxynaphthalene-2
-Carboxylic acid-(+)-2-methylbutyl ester 50
0, 550m9 of 4'-octyloxybiphenyl-4-carboxylic acid, 111g of DCC350 and PRLP
Y 207V in 4011 Ll of methylene chloride at room temperature
Allowed time to react. After filtering off the by-produced N,N'-dicyclohexylurea, the organic layer was washed with 5% hydrochloric acid, a 5% aqueous sodium hydroxide solution, and water in this order, and dried over anhydrous magnesium sulfate. After distilling off methylene chloride, the residue was purified using silica gel column chromatography using benzene as an eluent.

The crystals were further recrystallized from ethanol-ethyl acetate to form colorless prismatic crystals with 600 rn9 of 5-chloro-
6-(4”-octyloxybiphenyl-4′-carbonyloxy)naphthalene-2-carboxylic acid-((+1-
2''-methylbutyl) ester was obtained.

Yield: 59% Phase transition temperature is shown in Table 8.

6-(4"-alkyloxybiphenyl-4'-carbonyloxy)naphthalene-2-carboxylic acid (optically active alkyl) ester was produced by the same reaction procedure. Table 8 shows the phase transition temperature.

Table 8 Example 8 Production of 6-(6'-alkyloxynaphthalene-2'-carbonyloxy)naphthalene-2-carboxylic acid (optically active alkyl) ester 6-(6'-hexyloxynaphthalene-2'-carbonyloxy) ) Naphthalene-2-carboxylic acid-((+)-
2"-methylbutyl) ester (compound number 78 in Table 9)
Production example 6-hexyloxynaphthalene-2-carboxylic acid 530
rn9.6-Hydroxinaphthalene-2-carboxylic acid (
(+)-2'-methylbutyl) ester 500~, DC
0400m9 and PRLPY 20rIT9 were dissolved in Group 40 methylene chloride and reacted at room temperature for 5 hours. After filtering off the by-produced N,N'-dicyclohexylurea, the organic layer was washed with 5% hydrochloric acid, a 5% aqueous sodium hydroxide solution, and water in this order, and dried using anhydrous magnesium sulfate. After distilling off methylene chloride, the residue was purified using silica gel column chromatography using benzene as an eluent. The obtained crystals were further recrystallized from ethanol-ethyl acetate to give 580 units of 6-(6'-hexyloxynaphthalene-2'-carbonyloxy)naphthalene-2-carboxylic acid-((+ )-27-methylbutyl) ester was obtained. The phase transition temperatures are shown in Table 9.

Similarly, various 6-(6'-alkyloxynaphthalene-
2-carbonyloxy)naphthalene-2-carboxylic acid (
An optically active alkyl) ester was obtained.

Table 9 shows the phase transition temperatures for these compounds.

Table 9 Example 9 A liquid crystal composition composed of other liquid crystals shows an SO4 phase up to 57°C, an SA phase from 57 to 72°C, and becomes an isotropic liquid at higher temperatures, and the display element at around room temperature It is suitable as

Example 10 The liquid crystal mixture of Example 9 was injected into a cell in which silica was obliquely deposited on the electrode surfaces and the electrode spacing was 5 μm.

When this liquid crystal cell was sandwiched between two polarizers arranged in a crossed Nicol state and a 5V low frequency (IHz) alternating current was applied, a clear switching phenomenon was observed, and the contrast was very good, as well as the response speed. Very fast (I
msec or less) A liquid crystal display element was obtained. Note that the spontaneous polarization value Ps was 9 nC/crl.

Example 11 A liquid crystal compound composed of the liquid crystal compound of the present invention and another liquid crystal compound shows a Se4 phase up to 62°C, an SA phase from 62 to 83°C, and becomes an isotropic liquid crystal at a temperature higher than that at around room temperature. It is suitable as a display element.

Example 12 The liquid crystal mixture of Example 11 was injected into a cell in which silica was obliquely deposited on the electrode surfaces and the electrode spacing was 5 μm. When this liquid crystal cell was sandwiched between two polarizers arranged in a crossed Nicol state and a 5V low frequency (IHz) alternating current was applied, a clear switching phenomenon was observed, and the contrast was very good, as well as the response speed. A very fast (Imsec or less) liquid crystal display element was obtained.

In addition, the value of spontaneous polarization Ps is 8nC/cr! Met.

Claims (1)

[Claims] 1) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, X is a hydrogen atom or a halogen atom, Y and Z are R-, ▲Mathematical formula , chemical formulas, tables, etc.▼,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (Here, W is a hydrogen atom or a halogen atom, R is an alkyl group having 6 to 18 carbon atoms, and at least one of the alkyl groups contains an asymmetric carbon atom. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (n is an integer of 0 to 3, m is an integer of 1 or 2, *
is an optically active alkyl group represented by (indicates an asymmetric carbon atom). ) is a monovalent group represented by)). 2) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, X is a hydrogen atom or a halogen atom, Y and Z are R-, There is▼,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. At least one alkyl group contains an asymmetric carbon atom ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (n is an integer of 0 to 3, m is an integer of 1 or 2, * is an asymmetric carbon atom) 1. A liquid crystal composition comprising at least one liquid crystal compound represented by: an optically active alkyl group represented by ); a monovalent group represented by );