JPH0256446A - Liquid crystal material - Google Patents

Abstract

NEW MATERIAL:A liquid crystal compound having a tolan skeleton or a diarenylethane skeleton shown by formula I [R is 1-20 alkyl or alkoxy; Q is ethynylene or ethylene; m is 1-5: n is 0-5; * is asymmetric C]. EXAMPLE:A compound shown by formula II. USE:A component for chiral smectic liquid crystal composition. A ferroelectric liquid crystal compound useful as a display element having excellent responsibility of image display. PREPARATION:An optically active compound shown by formula III is reacted with a compound shown by formula IV in the presence of a complex mixture catalyst shown by formula V and triethylamine to form a compound shown by formula VI, which is reacted in the presence of NaH to give a compound shown by formula VII. A compound shown by formula VIII is reacted with a compound shown by formula IX in the presence of pyridine to give a compound shown by formula X, which is reacted with the compound shown by formula VII in the presence of the complex mixture catalyst shown by formula Y and triethylamine to give a compound shown by formula I wherein Q is ethynylene.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ferroelectric liquid crystal compound useful as a display element with excellent responsiveness for nine-image display, and a chiral smectic liquid crystal composition containing the same.

Currently, display elements using liquid crystal materials are of a light-receiving type, and have advantages such as low power consumption and the ability to create thin display devices, and are in widespread practical use. On the other hand, EL (electroluminescence) and plasma displays, which are light-emitting display systems and feature high-speed response, are being actively developed.

[Conventional technology]

Most of the liquid crystals that have been used for display elements so far have been nematic liquid crystals, and the mainstream is TNC twisted nematic (
Twisted Nematic ) ] type. Although this TN type display system has advantages such as small size and low power consumption, it also has the disadvantage that the response speed of nine-image display is slow. Improvements in this respect have been seen in seeds 4U, but
Molecular Crystals and the Kid Fighting Listals
dLiquid Crystals), Vol. 94, pp. 155-165, and it appears that the development of materials for TN type displays has almost reached its limit.

Therefore, in order to overcome the above-mentioned drawbacks, interest has recently shifted to the development of Kaif/Si liquid crystals instead of nematic liquid crystals, and in particular, considerable progress has been made in ferroelectric liquid crystals.

What was the first ferroelectric liquid crystal developed?

Rho C1oH21O8CH=N(3-CH=CH-CO
A compound represented by 2-H3 -CH2CHC2H5 * (in the formula, * represents an asymmetric carbon atom) (
(hereinafter abbreviated as DOBAMBC), its liquid crystal phase series and phase transition temperature (° C.) are as follows.

(In the formula, C is a crystalline phase, SA is a smectic A phase, Sc*
indicates chiral smectic C phase, SH* indicates chiral smectic H phase, and ■ indicates isotropic liquid, respectively).

Ferroelectricity is expressed in the chiral smectic C phase (hereinafter abbreviated as Sc*) or chiral smectic H phase (hereinafter abbreviated as Sl+*), which are classified and named based on the molecular arrangement.1The response based on ferroelectricity is expressed by the following formula [ A) τ-''/P5.ECA] (where τ is the response time, η is the viscosity of the liquid crystal material, Ps is the spontaneous polarization, and E is the electric field), so it is a display that can theoretically respond up to 1 μs. The possibility of obtaining such a device has been confirmed by researchers such as R.B.
urnal of physics France)
Volume 36, page 69 (1975).

[Problem that the invention seeks to solve]

There are compounds shown in Table 1 as typical ferroelectric liquid crystals. However, these compounds undergo isomerization in a short period of time when exposed to light, are unstable to moisture, exhibit liquid crystallinity due to hydrolysis reactions, and are therefore undesirable as materials for display elements.

Recently, ferroelectric liquid crystal compounds shown in Table 2 have been disclosed.

Table 2 [Means for solving problems] The present inventors have conducted intensive research from the above viewpoint.

We have discovered a ferroelectric liquid crystal compound with excellent stability, a high upper limit temperature belonging to the Sc* phase or the SH'' phase, and a large Ps value, and a liquid crystal composition containing the same, and have thus arrived at the present invention.

That is, 9 the present invention has the general formula [I] (f) In Table 2, R and R represent an alkyl group, and wood represents an asymmetric carbon atom, respectively.

These compounds solve the above problems.

Although the value of spontaneous polarization (Ps) is relatively large, the upper limit temperature of the chiral smectic phase exhibiting ferroelectricity is too low to be practical.

(In the formula, R is an alkyl group or an alkoxy group having 1 to 20 carbon atoms, and Q is an ethynylene group or an ethylene group.

m is an integer of 1 to 5, n is an integer of O to 5, and * is an asymmetric carbon atom). be.

The present invention also provides a liquid crystal composition containing at least one compound represented by the above general formula [I].

In the general formula (Il), the tolan skeleton is named as follows when Q is an ethynylene group.

3 2 2'3' Therefore, the compound represented by the above general formula [I] C, 4-(R or S
)-alkoxycarbonyl-4'-p-alkyl (or alkoxy)phenylcarbonyloxytran.

Specifically, in general formula (1), the diarynylethane skeleton is named as follows when Q is an ethylene group.

Therefore, the compound represented by the above general formula [I] is
1-C4-(R or S)-alkoxycarbonylphenyl:]-2-[4'-<p-alkyl or alkoxyphenyl]ethane.

The method for producing the compound represented by general formula [I] is detailed below, and an alcohol compound having an optically active group is used as one of the raw materials. It can be obtained at low cost due to its industrial versatility. For example, as a primary alcohol. 2-methylbutanol, 3-
Methylpentanol, 4-methylhexanol, 5-methylheptatool, 6-methyloctatool, etc. 2
R alcohol toshite. ■-Methyl propatool, 1-methylbutanol, l-methylpentanol.

(1)-Methyl hexanor/L/, l-methyl heptatool, (2)-methyl octatool, and the like are frequently used.

The outline of the method for producing the compound of the present invention is as follows.

[C]

[In the above formula, R is an alkyl group or a having a carbon number of 1 to 20, m is an integer of 1 to 5, n is an integer of O to 5, * indicates an asymmetric carbon atom), TEA is triethylamine, THF
represent tetrahydrofuran, respectively. ] [Function] The compound of the present invention exhibits the following actions and features.

First, in an atmosphere containing moisture. A group that can be easily decomposed, a group that does not have an azomethine group (-N=CH-) and is isomerized by light (-ζ)-〇H=C
Since it does not have H-), moisture. Very stable against light. Second, the compound of the present invention has a high upper limit temperature at which it exhibits ferroelectricity even when used alone. The compounds of the present invention. Or the compound of the present invention and an existing ferroelectric liquid crystal compound. For example, esters. Biphenyl type. By mixing pyrimidine etc.

It is also possible to set the lower limit of the temperature range exhibiting ferroelectricity to below room temperature.

Moreover, the compound of the present invention has a large Ps (spontaneous fraction IM) fh
tY when used as a blend material in a mixed system. In addition to achieving the objective of lowering the melting point, Ps in the mixed system
It is possible to improve the value.

〔Example〕

The present invention will be explained below by way of examples.

% in the examples indicates weight %.

500 CC. equipped with stirrer, thermometer and reflux condenser. In a three-necked flask, Ml element 'A in stream f 4 -
7 /l/ Koxycarponylbromobenzene 54 m
+nol, 3-methyl- 1-phytin-
3-all 5.91? (70
mmol).

270 μ of triphenylphosphine, 14 oq (0,2
0 mmol) and 60 m of triethylamine were added, stirred and dissolved, and 45~ of copper iodide was added. 3 at room temperature
After stirring for a while, gradually heat the mixture until the internal temperature reaches 80°C over 30 minutes.
And so. The reaction was allowed to proceed at this temperature for 10 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, and 300 ml of ether was added to the residue, which was washed with water and dried over anhydrous sodium sulfate. After filtration, the ether was distilled off, and the residue was subjected to silica gel column chromatography (200 mesh silica gel iI/10051, developing solvent dichloromethane) to obtain compound (A) of the 9th formula as an intermediate compound C.

300 cc with H3 stirring 2g, thermometer and distillation equipment,
The above compound [A] 5 was placed in a three-bottle flask in a nitrogen stream.
7.8 mmo+, 120 mt of anhydrous toluene, and 200 μm of sodium hydride (60% Nudur dispersant) were charged and stirred at room temperature for 30 minutes. Heat gradually.

It took 30 minutes to bring the internal temperature to 70°C. Acetone (by-product)
The mixture began to reflux and began to be distilled out together with toluene, but the reaction continued with further heating until the distillation temperature reached the boiling point of toluene. It took 2 hours during this time, and the solvent distilled out was 60ml.
Met. After the reaction is complete, return to room temperature and add 100 m
In addition, it was washed with water and dried with anhydrous sodium sulfate. After passing through F5, the organic solvent was distilled off, and the residue was subjected to silica gel column chromatography (200 mesh silica gel 100
F, developing solvent: benzene), 4- in Table 3
Alkoxy, dicarbonylphenylacetylene 85-8
Obtained with a yield of 8%. Its structure was confirmed by IR and NMR spectra.

The results are shown in Table 3.

Table sa Example 2 p-Bromophenyl-4-alkoxy (or (Note 1): There is an absorption peak based on CmiC at 2100 to 2150 F-1, but it is extremely weak.

In a 100 cc, three-neck flask equipped with a stirrer, thermometer, and reflux condenser, add 3.93 p-bromopheno-zlz.
9 (25 rnmol) and 10 ml of anhydrous pyridine were charged and dissolved under stirring. Add 20rr of 4-alkoxy (or alkyl)benzoyl chloride to this pyridine solution.
20 ml of a tetrahydrofuran solution containing unol was added under water cooling. After returning the reaction temperature to room temperature, it was brought to reflux temperature.

Stirred for 8 hours. After the reaction is complete, add benzene.

After washing with water, alkaline washing with 10% caustic soda, and washing with water, it was dried over anhydrous sodium sulfate.

The solvent was distilled off under reduced pressure, and the residue was isolated and purified as crystals from ethanol to give p-bromopheny/L/-4-alkoxy (or alkyl/l/)benzoate I:C) at 72%
Obtained in ~97% yield.

The results are shown in Table 4.

Table 4e (c) The clearing point in Table 4 indicates the transition point from a liquid crystal phase to an isotropic liquid, and () indicates the transition point from a liquid crystal phase to an isotropic liquid in a supercooled state below the melting point. show.

In a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, in a nitrogen atmosphere, the p-7'' lomophenyl)V-4-alkoxy (also Lt 7 /l/k/l) obtained in Production Example 2 was added.
/ ) Benzoate 4.8 old no! , 4-alcokynecarboni-phenylacetylene 5 obtained in Production Example 1,
0 mmo! , Triphenylphosphine 65Tng
, 32 ml of dichlorobin(triphenylphosphine) palladium catalyst and 80 ml of triethylamine were charged, stirred and dissolved, and 6 ml of copper iodide was added. After stirring at room temperature for 2 hours, the mixture was gradually heated to reflux temperature over 30 minutes. The reaction was allowed to proceed at this temperature for 10 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, and the residue was diluted with ether/L/
100 ml was added, washed with water, and dried over anhydrous sodium sulfate. After filtration, the ether was distilled off and the residue was subjected to silica gel column chromatography (200 mesh silica gel/
L/1oOr, R opening solvent: benzene/hexane = 171
) and isolated and purified. Recrystallized from hexane to obtain 4-alkoxycarbonyl-4-[p-alkoxy[or alkyl/l/)phenyl]carbonyloxytran[
I] was obtained in a yield of 81-90%. The structure of each compound is I
R.

Confirmed with NMR spectrum data.

Example 1. C compound floor 3] IR, J/, l,,,! 2928.1728.1720
．． 1276, 762 cm-"NMR: a":,'
, ¥38.1~6.8 (In, 12H), 5.1 (
m, LH).

4.0 (t, 2H), 2.0-0.7 (m, 31
~33H) ppm Example 2. [Compound I&L8] IR, νl11. x 2924,1732.17
12.1270,880°NMR:δ? Dt'r38.
1 (m, 4H), 7.6 (m, 4H), 7.3 (m, 4H)
H).

5.2 (m, LH), 2.7 (t, 2B), 1
．． 9-0.7 (m, , 30-31 H) 991n The results are shown in Table 5 along with the phase transition temperature of each compound obtained.

(f) The symbols in Table 5 indicate the following.

C: crystalline phase, Sx: smectic phase of undetermined identity.

S^: Smectic A phase, S(': Chiral smectic C phase.

Ch: cholesteric phase, ■ diisotropic liquid phase.

PS: value of spontaneous polarization (IIC//cnl).

was distilled off under reduced pressure. The crude product was purified by silica gel column chromatography (200 mesh silica gel/v5
oy, Ropen HK: benzene/hexane = 1/1). Yield was 90-97%. The structure of each compound was confirmed by IR and NMR spectra.

Example 1. [Combined moving part 13] In a flanco equipped with a stirrer, a thermometer, a reflux condenser, and a rubber balloon containing hydrogen gas, mf: 4-alkoxycarbonyl-lukoxy (or alkyl/V) phenyl] was added in Example 1. Carbonyloxytran 4.4 mmol, 5
% palladium-carbon catalyst and 500 ml of ethyl acetate were charged. After replacing with hydrogen gas, the reaction was carried out at room temperature. The extent of reaction progress was examined using a thin layer chromatography chip. The reaction was almost complete in about 6 hours. Stirring was continued in a hydrogen atmosphere for an additional 14 hours. After the reaction, remove the particles using a glass filter lined with dicalide. Ethyl acetate I
R, v,,, x2924, 1732, 1
708, 1280, 846.

762cm" NMR: δ::' 8.2-7.9 (m.4H),
7.3-6.8 (m, 8H).

5, 2 (m. 1) 1), 4.0 (t, 2H),
3.0 (8.4.H).

2, 1-0.67 (m, 31-32H) ppm Example 2.
[Compound NIL18] IR, ti,. 2928. 1730.
1710. 1278. 1178.

7 5 6 an-” NMR: δ?:s 8.1 (In, 4H), 7.8
(m, 8H), 5.1 (fll.IH).

3.0 (8,4H), 2.7 (t, 2H),
2.0 to 0.67 (+n, 31) 1) ppm The results are shown in Table 6 along with the phase transition temperature of each compound obtained.

(f) The symbols in Table 6 indicate the following.

C: crystalline phase, Sx: smectic phase of undetermined identity.

SA: smectic A phase, Sc*: chiral smectic C phase.

Ch: cholesteric phase, ■ diisotropic liquid phase.

PS: Value of spontaneous polarization (nC7crl) Example 3 Combined dynamic magnetism 7 in Table 5. Compounds No. 11 and N11 of Table 6
The liquid crystal compositions shown in Table 7 below were prepared using 12 liquid crystal compounds of the present invention, and the phase transition temperatures thereof were measured, and the results were as shown in Table 7.

Table 7 This liquid crystal composition was coated with a polyimide film and rubbed on one surface for parallel alignment treatment, and the cell thickness was controlled to 2 μm.Transparent! When injected into a cell with poles, Sc
A uniformly oriented cell was obtained. Also, under a temperature of 40℃
When IOV square wave voltage is applied, response time is 0.53 m.
5. Contrast) 10 display elements were obtained.

Example 4 A liquid crystal composition consisting of 80% of the liquid crystal composition of Example 3 and 20% of the compound represented by the following structural formula was prepared, and its phase transition temperature was measured, and the results were as follows.

35℃ 62℃ 92℃C--
---5c*---S8-111-■ When this liquid crystal composition was injected into a cell similar to the cell used in Example 3, a cell with uniform orientation could be obtained in Sc. Ta. When this cell responds at 40°C: 11J]o, 51m5. The contrast was 13. In addition to ester-based materials, it was also possible to lower the melting point and expand the temperature range of Sc* by mixing with biphenyl-based, pyrimidine-based liquid crystal compounds, etc.

Example 5 Compound N112. of Table 6. The liquid crystal compositions shown in Table 8 below were prepared using the liquid crystal compounds of the present invention of Magnetic 17 and N120, and the phase transition temperatures thereof were measured.

It was as shown in Table 8.

Table 8 When this liquid crystal composition was injected into a cell similar to the cell used in Example 3, it was possible to obtain a cell with uniform alignment under SC*. The response time of this cell at 45°C is 0.50m5.
A display element with a contrast of 10 was obtained.

Example 6 A liquid crystal composition consisting of 80% of the liquid crystal composition of Example 5 and 20% of the compound represented by the following structural formula was prepared, and its phase transition temperature was measured, and the results were as follows.

When this liquid crystal composition was injected into a cell similar to the cell used in Example 3, a cell with uniform orientation in Sc could be obtained. Response time of this cell at 40°C: 0.45 ms
, the contrast was 13. It was also possible to lower the melting point and expand the temperature range of Sc* by mixing it with other materials such as biphenyl and pyrimidine liquid crystal compounds.

〔Effect of the invention〕

As shown in Examples 1, 2.3, and 5 above, the compound of the present invention exhibits a Sc phase and has 9 ferroelectricity, and from the results of Examples 4 and 6, it has a wide temperature range including room temperature. It is clear that it will be an effective component in obtaining a chiral smectic liquid crystal composition.

Claims (1)

[Claims] 1. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. ▼ [I] (In the formula, R is an alkyl group or alkoxy group having 1 to 20 carbon atoms, and Q is an ethynylene group or ethylene group, m is 1 to 5
, n is an integer of 0 to 5, and * represents an asymmetric carbon atom, respectively. 2. The liquid crystalline compound according to claim 1, wherein Q is an ethynylene group. 3. The liquid crystal compound according to claim 1, wherein Q is an ethylene group. 4. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (In the formula, R is an alkyl group or alkoxy group having 1 to 20 carbon atoms, Q is an ethynylene group or ethylene group, and m is 1 ~5
, n is an integer of 0 to 5, and * represents an asymmetric carbon atom). liquid crystal composition. 5. The liquid crystal composition according to claim 4, wherein Q is an ethynylene group. 6. The liquid crystal composition according to claim 4, wherein Q is an ethylene group.