JPS6127931A - Trans-ethylene derivative compound and liquid crystal composition containing same - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (-CH=CH- is trans-1,2-disubstituted ethylene bond; R is 1-8C alkyl; X is cyano, F or Cl). EXAMPLE:4-Chloro-4'-(trans-3''-pentenyl)biphenyl. USE:A component of a liquid crystal composition. It constitutes a liquid crystal composition having relatively high clearing point, high refractive index anisotropy and dielectric anisotropy and low viscosity, and is poured into an electrical and/or thermo-optical liquid crystal element or into a liquid crystal cell. The element or cell can be used in watches, electronic calculators, instruments, automotive meters, gaming machines, computer displays, etc. PREPARATION:The compound of formula I wherein X is Cl can be prepared by (1) reacting the compound of formula II with Br2 to obtain the compound of formula III, (2) preparing a Grignard reagent from the compound of formula IVand Mg, and (3) reacting the Grignard reagent with the compound of formula IIIin the presence of a coupling catalyst such as bis(1,2-diphenylphosphino)ethane nickel (II) chloride.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a trans-ethylene derivative compound used in liquid crystal electrical and/or thermo-optic elements and a liquid crystal composition containing the same.

[Prior Art] In the field of display devices, electrical and/or thermo-optical devices with low power consumption and high speed response are desired. Liquid crystal display elements utilize changes in the nematic, smectic, and cholesteric phases of liquid crystals due to electricity and/or heat, and are attracting attention as devices that meet such demands.

None of the liquid crystal materials used in liquid crystal display elements can withstand use alone in terms of operating temperature range, operating voltage, response performance, etc., and currently a mixture of several types of liquid crystal materials is used.

[Problems to be solved by the present invention J] Liquid crystal display elements using conventionally used liquid crystal mixtures do not operate at high temperatures, have insufficient contrast due to small refractive index anisotropy (Δn), and have low dielectric constant anisotropy. It had drawbacks such as a high operating voltage due to its low polarity, and a slow response speed due to its high viscosity.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems. - represents a trans-1,2-disubstituted ethylene bond, R represents an alkyl group of 8, and X represents a cyan group, a fluorine atom, or a chlorine atom). A liquid crystal composition characterized in that a derivative compound and at least one of the compounds are mixed in an amount of 1 to 50 wt%.

The general name of the compound represented by general formula (I) is 4-substituted-
4'-(trans-3''-fulkenyl)biphenyl.

In the compound represented by general formula (I), R has 1 carbon number
-8 alkyl group, but since the viscosity is generally high when the number of carbon atoms is large, the number of carbon atoms is preferably 1-5, and more preferably 1-5.
3 is preferred. Furthermore, since the clearing point of a liquid crystal composition to which the compound is added is generally lower than when R is an alkyl group having a branched chain, R is preferably a linear alkyl group.

Since the trans-ethylene derivatives of the present invention do not exhibit a sufficiently wide operating temperature range by themselves, one or more of them may be mixed with other liquid crystal compounds to obtain a mixture with a desired liquid crystal temperature range. In this case, the compound of the present invention is used in the mixture in an amount of 1 to 50 wt$, more preferably 3 to 30 wt$. Other liquid crystalline compounds vary depending on the application, required performance, etc., but they consist of a component that exhibits liquid crystallinity and additive components that are added as necessary, such as a component that exhibits liquid crystallinity at high temperatures, a low-viscosity component for low temperatures, Other components that improve dielectric anisotropy, components that impart cholesteric properties, components that have dichroism, components that impart electrical conductivity, and other additives may be mixed as appropriate.

Specifically, there are the following compounds.

Unlike R in the present invention, R and R' in the following formula represent groups such as an alkyl group, an alkoxy group, a halogen atom, and a cyano group.

R call o-N=N-o-R' Various materials can be selected and used, such as substitution with other six-membered rings, five-membered rings, etc., and changes in bonding groups between rings.

The composition of the present invention is used by being injected into a liquid crystal cell.

A typical electro-optic cell is a twisted nematic (TN) type liquid crystal cell, in which transparent electrodes such as In2O3-5n02 are formed in a desired pattern on the inner surface of a transparent substrate such as glass or plastic. 5i02 according to
The substrates with horizontal alignment layers are placed facing each other with an overcoat such as polyimide, the periphery is sealed, liquid crystal is injected and the injection port is sealed, and polarizing plates are laminated on both outer surfaces. used. In addition to this, there is also a phase transition type.

Guestphos I [, a dynamic scattering type, or a combination thereof may be used, or a type that performs writing by heat rather than electrically may be used.

Furthermore, as for the structure of the cell, between the transparent substrate and the transparent electrode,
Various applications are possible, such as providing an undercoat layer such as 5i02, Al2O2, using a reflective electrode, using a two-layer electrode, using a color polarizing plate, using a color filter, using a semiconductor substrate, and creating a two-layer device. and
It can be used for various purposes such as watches, calculators, measuring instruments, automobile instruments, games, computer terminals, etc.

A compound in which X is a chlorine atom in general formula (I) can be synthesized, for example, through the following steps.

↓Br2 That is, by reacting the compound of formula (II) with bromine (m
), and (III) is reacted with a Grignard reagent prepared from (IV) and magnesium in the presence of a coupling catalyst such as N1(dppe)C12 to obtain a compound of formula (I) in which X is a chlorine atom.

A compound in which X is a fluorine atom in general formula (I) can be synthesized, for example, through the following steps.

↓Br2 That is, in the same manner using the compound of formula (V) as a starting material, a compound of formula CI) in which X is a fluorine atom is obtained.

Further, a compound in which X is a cyano group in general formula (I) is synthesized, for example, through the following steps.

That is, in formula (I), a compound in which X is a chlorine atom is reacted with magnesium and then carbonated to form (■), and (■
) with a chlorinating agent such as oxalic acid dichloride (■)
Then, by reacting (■) with concentrated ammonia water, the amide (
IX) and dehydration of (IX) in the presence of a dehydrator such as para-toluenesulfonyl chloride provides a compound of formula CI) in which X is a cyan group.

[Example] Next, the present invention will be specifically explained using examples.

200 g of the compound of Example 1, 20 g of fine iron powder, and 500 g of carbon tetrachloride.
175 g of bromine was added dropwise to the mixture of m1, and the mixture was stirred at 30° C. or lower for 16 hours. Dichloromethane was added, and the organic layer was washed with an aqueous sodium sulfite solution, an aqueous sodium hydroxide solution, and further washed with water. After drying by adding anhydrous sodium sulfate, the solvent was distilled off, and the residual liquid was recrystallized twice from toluene to obtain a compound. Yield: 227g.

Next, from 14.9 g of a compound of the formula CHs-CH=CH-GH2-CH2Br and magnesium turnings, 40 g of ether
It took 30 minutes to prepare the Glycoyer reagent in +OL and wash the compound with the synthesized compound, benzene 80111, 40 ml of ether, and 0.5 g of bis(1,2-diphenylphosphino)ethanenickel(II) chloride. After stirring at room temperature for 4 hours, l
:5 300 ml of hydrochloric acid was added, the organic layer was separated, and the aqueous layer was extracted with dichloromethane. The organic layers were combined into one, washed with water, dried over anhydrous sodium sulfate, and the solvent was distilled off. The residue was recrystallized from n-hexane and further
12.8 g of 4-chloro-4'-()lance-3''-pentenyl)biphenyl was obtained by distillation.

Yield 83% Melting point 75.2℃ Its infrared spectrum (K
Br tablet) is shown in Figure 1.

Example 2 4-fluoro-4'-(trans-3''-pentekol)biphenyl represented by was obtained in the same manner as in Example 1 except that the compound in Example 1 was replaced with the following compound. The infrared spectrum (KBr tablet) of this compound is shown in Figure 2.
The HNMR spectrum was as follows.

'HNMR (CDCh solvent, TMS internal standard) δ (pp
m) 1.5-1.7 Cd, 4Hz 3H
)2.0~2.8 (complex m,
4H) 5.3~5.5 (com'pl'ex'
m, 2H) 8.8~? ,8' (complex
m, "8H) Example 3 A mixture of 12.8 g of the compound obtained in Example 1, 10.9 g of ethyl bromide and 60 ml of tetrahydrofuran was heated under a nitrogen stream.
Magnesium shavings 3.6g Tetrahydrofuran 40I
The mixture was added dropwise to the mixture of Ill at room temperature with stirring over 1 hour, and the mixture was further heated under reflux for 6 hours. Carbon dioxide gas is introduced while maintaining the temperature at -15°C.

Return to room temperature, add 1:5 hydrochloric acid, then add dichloromethane, separate the organic layer, wash with water, dry over anhydrous magnesium sulfate, evaporate the solvent, and recrystallize the residue from toluene to obtain the compound. 8.5g was obtained. Yield 71%.

4.2 g of the compound of formula (GOCI)2 and 8.1 g of the compound of formula (GOCI)2
Tetrachloride! ! 251. The mixture was mixed with 25 ml of benzene, 1 drop of N,N-diethylaniline was added, and the mixture was heated under reflux for 3 hours. Next, the excess (0001) 2 and the solvent were distilled off, and the resulting compound was diluted with n- The solution was dissolved in 30 ml of hexane and added dropwise to 30 ml of concentrated aqueous ammonia at 15° C. or below, and the precipitated compound was collected and dried under reduced pressure. Yield 3.9g Yield 83
% decomposition point 24.8°C. Its infrared spectrum (KBr tablet) is shown in Figure 3.

1.7g of compound, 1.4g of pyridine, 25m of benzene
1 and heated under reflux for 10 hours. After cooling the reaction mixture to room temperature, the furnace solution was chromatographed with alkaline n-hexane and recrystallized twice from n-hexane to give 4-cyano-4'-( ) Lance-3”-
(pentenyl)biphenyl was obtained. The melting point was 76.4°C. Observation under a polarizing microscope revealed that it was a monotropic liquid crystal that changed from an isotropic liquid to a nematic phase at 72.6°C upon cooling. The IR spectrum diagram of this compound (KBr tablet) is shown in the 4th column.
As shown in the figure. Moreover, the IHNMR spectrum of this compound was as follows.

IHNMR (CDCh solvent, TMS internal standard) δ (pp
m) 1.5-1. ? (d, J= tHz 3H
)2.0~2.85 (complex m,
4H) 5.4-5.8 (complex ta,
2H) 7.2 ~ 7.8 (complex
ra, 8H) Examples 4 to 9 Compounds 1 to 9 were obtained in the same manner as in Example 1.

4-chloro-4'-()lans-3''-hexenyl)biphenyl 4-chloro-4'-()lanse-3''-hebutenyl)biphenyl The following compound was obtained in the same manner as in Example 2. .

4-Fluoro-4'-()lans-3''-hexenyl)biphenyl 4-fluoro-4'-()lanse-3''-hebutenyl)biphenyl - In the same manner as in Example 3, the following compound was prepared. Obtained.

4-cyano-4'-()lans-3''-hexenyl)biphenyl 4-cyano-4'-()lanth-3''-hebutenyl)biphenyl Example 10 Compound 15wj$tl) Lt Risha Liquid Crystal (ZLI
-1585) 71,
It exhibited a nematic-isotropic liquid transition temperature of 3°C. 1 Its refractive index anisotropy is 0.131 at 25°C, and Z
That of LI-1565 was 0.124.

It can be seen that the compound is useful for increasing refractive index anisotropy.

A mixture of equal weights of the compound (referred to as base liquid crystal A) exhibits -1,52 dielectric constant anisotropy at 0°C;
The mixture added to the 5wt1 base liquid crystal has a temperature of -0 at 0°C.
, 87. It can be seen that this compound is useful for increasing dielectric anisotropy.

Compound 20wt! and Merck liquid crystal (ZLI-108
3) A 55 wt% mixture has a temperature of 45% at 0°C. ? cst
However, a liquid crystal composition in which 15 wt% of the compound was mixed with this mixed liquid crystal showed a viscosity of 37.7 cst at 0°C. Such compounds are found to be useful in reducing viscosity.

Compound of Example 11? , 8wt1 and host liquid crystal A 82.2wtX exhibited a nematic-isotropic transition temperature of π]. Also, its dielectric anisotropy is +O at 0°C, ? It was 5. The dielectric constant anisotropy of the base liquid crystal A at 0°C is -1,
52 is found to be useful for increasing dielectric anisotropy.

[Effects of the Invention] As described above, the present invention provides novel compounds in which -0
H-OH- represents a trans-1,2-disubstituted ethylene bond, R represents an alkyl group having 1 to 8 carbon atoms, and X represents a cyano group, a furan atom, or a chlorine atom). By providing an ethylene derivative compound, a liquid crystal composition having a relatively high clearing point, large refractive index anisotropy, large dielectric constant anisotropy, and low viscosity can be produced. It is something.

[Brief explanation of the drawing]

FIG. 1 shows the compound of Example 1, FIG. 2 shows the compound of Example 2, and FIG. 3 shows an intermediate for the synthesis of the compound of Example 3.
FIG. 4 is an infrared spectrum diagram of the compound of Example 3. Note 10 False-l ' Third Showa Procedural Amendment (Method) % Formula % 1. Description of the case 1982 Patent Application No. 146051 2. Name of the invention Trans-ethylene derivative compound and liquid crystal composition containing the same 3 , Relationship with the case of the person making the amendment Patent applicant address 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Name
(004) Asahi Glass Co., Ltd. 5. Date of amendment order: October 30, 1980 (shipment date) 8. Number of inventions increased by amendment: None 7.
Subject of amendment Specification 8, Contents of amendment As shown in the engraving of the specification originally attached to the application (no change in content) 8. Written amendment to attached documents procedure December 7th, 1982

Claims (3)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) (In the formula, -CH=CH- represents a trans-1,2-disubstituted ethylene bond, and R is an alkyl group having 1 to 8 carbon atoms. (X represents a cyano group, a fluorine atom, or a chlorine atom). (2) The trans-ethylene derivative compound according to claim 1, wherein in formula (I), R is a linear alkyl group having 1 to 5 carbon atoms. (3) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) (In the formula, -CH=CH- represents a trans-1,2-disubstituted ethylene bond, and R is an alkyl group having 1 to 8 carbon atoms. 1. A liquid crystal composition comprising 1 to 50 wt % of at least one trans-ethylene derivative compound represented by the following formula (X represents a cyano group, a fluorine atom, or a chlorine atom).