JP2622514B2 - Liquid crystal material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal compound useful for a display device or an electro-optical device and a liquid crystal composition containing the same.

[0002] At present, display elements made of liquid crystal materials are of a light-receiving type display method, and are widely used in practice because of their features such as low power consumption and fabrication of thin display devices. On the other hand, with a light-emitting display method, large screen display is possible
The development of electroluminescence (EL) and plasma displays characterized by high-speed response is also active.

[0003]

2. Description of the Related Art Most liquid crystals used in display devices are nematic liquid crystals, and the mainstream liquid crystal is a TN (Twisted Nematic) type. The TN display method has advantages such as small size and low power consumption, but has a disadvantage that the response speed of image display is slow. Development of a new liquid crystal display method is indispensable in order to make use of the characteristics of the liquid crystal display element such as a light receiving type and low power consumption and to secure a response comparable to a light emitting type display. As one of the attempts, a display device using the optical switching phenomenon of ferroelectric liquid crystal has been proposed.

[0004] Ferroelectricity is classified into chiral smectic C phase and chiral smectic I, which are classified and named on molecular arrangement.
Phase, chiral smectic F phase, chiral smectic G phase and chiral smectic H phase (hereinafter referred to as S
_C ^* phase, S _I ^* phase, S _F ^* phase, S _G ^* phase and S _H ^* abbreviated) to express the intensity response following equation based on dielectric [a] τ = η / Ps · E [a (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 possible to obtain a display element that can theoretically respond up to 1 μs. .

[0005] At present, ferroelectric liquid crystal compounds have a helical structure like cholesteric liquid crystals. It is necessary to unwind this spiral for the optical switching phenomenon to appear in the ferroelectric liquid crystal. One method of unwinding is to manufacture a cell in which the cell gap is controlled to a helical pitch P or less,
The helical pitch of many compounds is 1 to 3 μm, which is difficult with current cell fabrication technology. On the other hand, a method of unwinding a spiral has been considered from the viewpoint of the technique of compounding a liquid crystal compound (JP-A-61-195187). This is a method in which a compound having a smectic C phase is mixed with a ferroelectric smectic liquid crystal compound or a composition thereof. According to this method, a method of blending ferroelectric smectic liquid crystals (Japanese Patent Application Laid-Open Nos. 60-90290 and 61-17429).
Since the compounding is simplified as compared with No. 4), it is important for obtaining a practical liquid crystal composition.

[0006]

SUMMARY OF THE INVENTION Therefore, smectic C
As a compound having a phase, the temperature range showing the smectic C phase is wide and its maximum temperature is high, it mixes well with the ferroelectric smectic liquid crystal compound, and it is chemically, thermally and light-stable. It is desired to have various properties.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies from the above-mentioned viewpoints, and as a result, have excellent stability, are well mixed with a ferroelectric smectic liquid crystal compound, and have a wide temperature range showing a smectic C phase. The inventors have found a liquid crystal compound having a high maximum temperature and a liquid crystal composition containing the same, and have reached the present invention.

That is, the present invention provides a compound represented by the general formula [I]:

[0009]

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(Wherein, R ¹ represents a linear alkyl group or a linear alkoxy group having 1 to 20 carbon atoms, and R ² represents a linear alkyl group having 1 to 20 carbon atoms.)
Represents an optically active alkoxy group having an asymmetric carbon atom of
Y is

[0011]

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And Z is

[0013]

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And Q is

[0015]

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X represents a hydrogen atom or a halogen atom, respectively).

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

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Specific examples of typical examples of the compound represented by the general formula [I] can be divided into the following groups by the combination of Y, Q and Z in the formula.

[0019]

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(In the above formulas, R ¹ , R ² and X have the same meanings as described above.) The outline of the method for producing the compound of the present invention is as follows.

[0021]

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(In the above formulas, R ¹ , R ² , X and Y have the same meanings as described above, and TEA represents triethylamine.) The compounds of the present invention have the following actions and characteristics.

First, in an atmosphere containing water, since there is no group that can be easily decomposed or a group that isomerizes by light, it is very stable against moisture and light.

Next, since most of the compounds of the present invention show a smectic C phase in a wide temperature range alone, the compounds of the present invention and a compound of the present invention and a compound having an existing smectic C phase, for example, an ester compound, Smectic C is obtained by mixing biphenyl and pyrimidine compounds.
The temperature range showing the phase can be extended to a wide range including room temperature. Therefore, practically, even if the ferroelectric chiral smectic liquid crystal compound to be mixed has a narrow temperature range exhibiting ferroelectricity, the compound can be mixed, so that the range in which the compound can be selected is widened. It is also possible to mix the compound of the present invention with an optically active compound which does not exhibit ferroelectricity by itself.

According to the present invention, the compound of the formula [I] exhibiting optical activity has the ability to induce a twisted structure by adding it to a nematic liquid crystal. A nematic liquid crystal having a twisted structure, that is, a chiral nematic liquid crystal, does not generate a so-called reverse domain of a TN display element, and therefore the formula [I] showing the optical activity of the present invention is obtained. Can be used as an inhibitor of reverse domain formation.

[0026]

EXAMPLES The present invention will be described below by way of examples, wherein% in the examples indicates% by weight.

Production Example 1 4-Alkoxyphenylacetyl
Synthesis of Ren [B] In a 500 ml three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, 64 mmol of 4-alkoxybromobenzene and 3-methyl-1-butyn-3-ol in a nitrogen stream were introduced. 91 g (70 mmol), 270 mg of triphenylphosphine, 140 mg (0.20 mmol) of a dichlorobis (triphenylphosphine) palladium catalyst and 60 ml of triethylamine were charged and dissolved by stirring, and 45 mg of copper iodide was added. After stirring at room temperature for 3 hours, the mixture was gradually heated, and the internal temperature was adjusted to 80 ° C. in 30 minutes. The reaction was performed at this temperature for 10 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, 300 ml of ether was added to the residue, washed with water, and dried over anhydrous sodium sulfate. After filtration, ether was distilled off, and the residue was subjected to silica gel column chromatography (silica gel 100 mesh of 200 mesh).
g, developing solvent: benzene) to obtain a compound [A] of the following formula as an intermediate compound (yield 70-87%).

[0028]

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30 equipped with a stirrer, thermometer and distillation apparatus
In a 0 ml three-necked flask, 57.8 mmol of the compound [A], 120 ml of anhydrous toluene and sodium hydride (60% nujol dispersion) were placed in a nitrogen stream.
Then, the mixture was stirred at room temperature for 30 minutes. The temperature was gradually increased to 30 ° C. for 30 minutes. Reflux of acetone (by-product) started, and distillation started with toluene. The reaction was continued by further heating until the distillation temperature reached the boiling point of toluene. It took 2 hours during this time to remove 6
It was 0 ml. After the completion of the reaction, the temperature is returned to room temperature, and benzene 1
The residue was washed with water and dried over anhydrous sodium sulfate. After filtration, the organic solvent was distilled off, and the residue was subjected to silica gel column chromatography (100 g of 200-mesh silica gel, developing solvent: hexane).
Alkoxyphenylacetylene [B] was obtained in a yield of 85 to 95%. Its structure was confirmed by IR and NMR spectra.

The results are shown in Table 1.

[0031]

[Table 1]

Production Example 2 p-bromophenyl 4-al
Synthesis of Coxy (or alkyl) benzoate [C] In a 100 ml three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, 3.93 g (2.
5 mmol) and 10 ml of anhydrous pyridine were charged and dissolved with stirring. To this pyridine solution, 20 ml of a tetrahydrofuran solution containing 20 mmol of 4-alkoxy (or alkyl) benzoyl chloride was added under ice cooling. After returning the reaction temperature to room temperature, the mixture was brought to the reflux temperature and stirred for 8 hours.
After completion of the reaction, benzene was added, washed with water, washed with 10% caustic soda with alkaline water, washed with water in that order, and 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 obtain p-bromophenyl 4-alkoxy (or alkyl) benzoate [C] in Table 2 in a yield of 72 to 97%. .

Production Example 3 p-bromophenyl 4-al
Synthesis of Coxy-3-chlorobenzoate [C] Synthesis was performed under the same conditions as in Preparation Example 2 except that 20 mmol of 4-alkoxy-3-chlorobenzoyl chloride was used instead of 20 mmol of 4-alkoxy (or alkyl) benzoyl chloride. P-bromophenyl 4-alkoxy-3-chlorobenzoate [C]
Obtained in 2-91% yield.

Table 2 shows the above results.

[0035]

[Table 2]

Production Example 4p-alkoxy (or alkyl
L) Synthesis of phenyl 4-bromobenzoate [C] 100 ml three-piece with stirrer, thermometer and reflux condenser
P-Alkoxy (or alkyl)
Charge 18.2 mmol of ethanol and 10 ml of anhydrous pyridine
And dissolved under stirring. To this pyridine solution was added 4-bro
4.30 g of mobenzoyl chloride (19.6 mmol
20 ml of a tetrahydrofuran solution containing
I got it. After returning the reaction temperature to room temperature, it was set to the reflux temperature,
While stirring. After the completion of the reaction, benzene was added, washed with water,
Washed in the order of alkaline water with sodium hydroxide and water
Then, it was dried over anhydrous sodium sulfate. Solvent is removed under reduced pressure
The residue was isolated and purified from ethanol, and the p-
Alkoxy (or alkyl) phenyl 4-bromoben
Zoate [C] was obtained in 80-98% yield.

Production Example 5 4'-Alkoxy-3'-chloro
Synthesis of luphenyl 4-bromobenzoate [C] p-alkoxy (or alkyl) phenol 18.2m
All were synthesized under the same conditions as in Production Example 4 except that 18.2 mmol of 4-alkoxy-3-chlorophenol was used instead of mol, and 4′-alkoxy-3′-chlorophenyl 4-bromobenzoate [C] in Table 3 was used. 88 to 89
% Yield.

Table 3 shows the above results.

[0039]

[Table 3]

Production Example 6p-alkoxy (or alkyl
L) Synthesis of phenyl 6-chloronicotinate [D] 100 ml three-piece with stirrer, thermometer and reflux condenser
P-Alkoxy (or alkyl)
30 mmol of ethanol and 20 ml of anhydrous pyridine were charged,
Dissolved with stirring. To this pyridine solution, add 6-chlorni
Dichloroethane containing 35 mmol of cotinyl chloride
50 ml of the solution was added under ice cooling. The reaction temperature was returned to room temperature
Thereafter, the mixture was heated to 40 ° C. and stirred for 8 hours. After the reaction is complete,
Add senzen, wash with water, and 10% caustic soda in alkaline water
After washing and then washing with water, dry over anhydrous sodium sulfate.
did. The solvent is distilled off under reduced pressure and the residue is
After isolation and purification, the p-alkoxy (or alkyl)
88-95% of phenyl 6-chloronicotinate [D]
In a yield of

Production Example 7 4'-Alkoxy-3'-chloro
Synthesis of ruphenyl 6-chloronicotinate [D] p-alkoxy (or alkyl) phenol 30 mmol
4-alkoxy-3-chlorophenol 30 in place of 1
Synthesis was performed under the same conditions as in Production Example 6 except that mmol was used, and 4′-alkoxy-3′-chlorophenyl 6-chloronicotinate [D] in Table 4 was obtained at a yield of 83%.

Table 4 shows the above results.

[0043]

[Table 4]

Example 1 4- [p-alkoxy (or
Alkyl) phenylcarbonyloxy] -4'-alkoxy
Synthesis of Citran [Ia] (when X = H) In a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, the p-bromophenyl-4-alkoxy obtained in Production Example 2 was placed in a nitrogen stream. (Or alkyl) benzoate4.
8 mmol, 5.0 mmol of 4-alkoxyphenylacetylene obtained in Production Example 1, 65 mg of triphenylphosphine, 32 mg of dichlorobis (triphenylphosphine) palladium catalyst and 30 ml of triethylamine were charged, stirred and dissolved, and 6 mg of copper iodide was added. After stirring at room temperature for 2 hours, the mixture was gradually heated to 90 ° C. over 30 minutes. The reaction was carried out at this temperature for 16 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, 100 ml of ether was added to the residue, washed with water, and dried over anhydrous sodium sulfate. After filtration, ether was distilled off, and the residue was subjected to silica gel column chromatography (100 g of 200-mesh silica gel, developing solvent: benzene / hexane = 1 /
It was isolated and purified in 1). Recrystallization from hexane gave 4- [p-alkoxy (or alkyl) phenylcarbonyloxy] -4'-alkoxytolan [I] in Table 5 in 87-92% yield. The structure of each compound was confirmed by IR and NMR spectrum data.

[0045]

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Example 2 4- (4 "-alkoxy-3"
-Chlorophenylcarbonyloxy) -4'-alkoxy
Synthesis of Citran [Ia] (when X = Cl) p-bromophenyl-4-alkoxy (or alkyl)
The synthesis was carried out under the same conditions as in Example 1 except that 4.8 mmol of p-bromophenyl-4-alkoxy-3-chlorobenzoate obtained in Production Example 3 was used instead of 4.8 mmol of benzoate. (4 "-Alkoxy-3" -chlorophenylcarbonyloxy) -4'-alkoxytolan [I] was obtained in a yield of 80 to 89%. The structure of each compound was confirmed by IR and NMR spectrum data.

The results are shown in Table 5 together with the phase transition temperature of each compound obtained in Examples 1 and 2.

[0048]

[Table 5]

Example 3 4- [p-alkoxy (or
Alkyl) phenyloxycarbonyl] -4'-alkoxy
Synthesis of Citran [Ib] (when X = H) In a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser, the p-alkoxy (or alkyl) phenyl-4-bromo obtained in Production Example 4 was added. Benate 4.8 mmol,
5.0 mmol of 4-alkoxyphenylacetylene obtained in Production Example 1, 65 mg of triphenylphosphine, 32 mg of dichlorobis (triphenylphosphine) palladium catalyst and 30 ml of triethylamine were charged, dissolved by stirring, and 6 mg of copper iodide was added. After stirring at room temperature for 2 hours, the mixture was gradually heated to 80 to 90 ° C. over 30 minutes. The reaction was performed at this temperature for 10 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, 100 ml of ether was added to the residue, washed with water, and dried over anhydrous sodium sulfate. After filtration, ether was distilled off, and the residue was subjected to silica gel column chromatography (100 g of 200-mesh silica gel, developing solvent: benzene / hexane = 1 /
It was isolated and purified in 1). Recrystallization from hexane gave 4- [p-alkoxy (or alkyl) phenyloxycarbonyl] -4'-alkoxytolan [I] in Table 6 in 83-92% yield. The structure of each compound was confirmed by IR and NMR spectrum data.

[0050]

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Example 4 4- (4 "-alkoxy-3"
-Chlorophenyloxycarbonyl) -4'-alkoxy
Synthesis of Citran [Ib] (when X = Cl) Instead of 4.8 mmol of p-alkoxy (or alkyl) phenyl-4-bromobenzoate, 4'-alkoxy-3'-chlorophenyl- obtained in Preparation Example 5 Synthesized under the same conditions as in Example 3 except that 4.8 mmol of 4-bromobenzoate was used, and 4- (4 ″ -alkoxy-3 ″ -chlorophenyloxycarbonyl) -4 ′ in Table 6 was used.
-Alkoxytolan [I] was obtained in a yield of 81-91%. The structure of each compound was confirmed by IR and NMR spectrum data.

The results are shown in Table 6 together with the phase transition temperatures of the respective compounds obtained in Examples 3 and 4.

[0053]

[Table 6]

Embodiment 5p-alkoxy (or alkyl
Ru) phenyl 6- (p-alkoxyphenyl) ethini
Synthesis of Lunicotinate [Ic] (when X = H) In a reaction vessel, the p-A obtained in Production Example 6 was placed in a nitrogen stream.
Lucoxy (or alkyl) phenyl-6-chloronicot
4.8 mmol, 4-alcohol obtained in Production Example 1
5.0 mmol of xyphenylacetylene, triphenyl
65 mg of phosphine, dichlorobis (triphenylphos
Fin) 32 mg of palladium catalyst and triethylamine
Charge 30 ml, dissolve with stirring, add 6 mg of copper iodide
Was. After stirring for 2 hours at room temperature, gradually heat up and take 30 minutes
To 80 ° C. The reaction was carried out at this temperature for 16 hours. reaction
After that, the temperature was returned to room temperature, and triethylamine was distilled off under reduced pressure.
100 ml of ether was added to the distillate, and the mixture was washed with water.
Dried with thorium. After filtration, ether was distilled off and the residue remained.
The product is subjected to silica gel column chromatography (200 mesh).
100 g silica gel, developing solvent: benzene)
And purified. Recrystallized from hexane to obtain p
-Alkoxy (or alkyl) phenyl 6- (p-a
(Rucoxyphenyl) ethynyl nicotinate from 80 to 84
% Yield. The structure of each compound is represented by IR and NMR spectra.
Confirmed by the vector data.

Example 6 4'-Alkoxy-3'-chloro
Luphenyl 6- (p-alkoxyphenyl) ethynyl
Synthesis of nicotinate [Ic] (when X = Cl) 4'-alkoxy-3'-chlorophenyl obtained in Preparation Example 7 instead of 4.8 mmol of p-alkoxy (or alkyl) phenyl-6-chloronicotinate All were synthesized under the same conditions as in Example 5 except that 4.8 mmol of -6-chloronicotinate was used.
3'-Chlorophenyl 6- (p-alkoxyphenyl) ethynylnicotinate was obtained in 79-85% yield. The structure of each compound was confirmed by IR and NMR spectrum data.

Table 7 shows the results together with the phase transition temperatures of the compounds obtained in Examples 5 and 6.

[0057]

[Table 7]

Embodiment 71- (p-alkoxyphenyl)
) -2- {4 '-[p-alkoxy (or alkyl)
Phenylcarbonyloxy] phenyldiethane [Id]
Synthesis (when X = H) Stirrer, thermometer, reflux condenser, and rubber with hydrogen gas
In a flask equipped with a balloon, the 4- [p-
Alkoxy (or alkyl) phenylcarbonyloxy
[S] -4'-alkoxytolan 4.4 mmol, 5%
500 mg of radium-carbon catalyst and 10 ml of ethyl acetate
, And reacted at room temperature after purging with hydrogen gas. Responsive
The extent of progress was examined with a thin-layer chromatographic chip. The reaction is about 1
Time is almost complete, but further 2 hours in a hydrogen atmosphere
I continued to respond. After the reaction, a glass filter lined with a filter aid
The catalyst was removed with a solvent, and ethyl acetate was distilled off under reduced pressure. Anti
The crude product is subjected to silica gel column chromatography (2
50 g of 00 mesh silica gel, developing solvent: Benze
And purified from the 1- (p-alkoxyphene) in Table 8.
Nil) -2- {4 ′-[p-alkoxy (or alkyl
Phenylcarbonyloxy] phenyldiethane
[I] was obtained in 90-97% yield. The structure of each compound is
Confirmed by IR and NMR spectrum data.

[0059]

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Embodiment 81- (p-alkoxyphenyl)
) -2- [4 '-(4 "-alkoxy-3" -chloro
Phenylcarbonyloxy) phenyl] ethane [Id]
Synthesis of (when X = Cl) 4- [p-alkoxy (or alkyl) phenylcarbo
Nyloxy] -4'-alkoxytolan 4.4 mmol
Instead of 4- (4 ″ -alkoxy-) obtained in Example 2.
3 "-chlorophenylcarbonyloxy) -4'-al
Performed except for using 4.4 mmol of coxitran
Synthesized under the same conditions as in Example 7, and 1- (p-alkoxy) in Table 8 was used.
Phenyl) -2- [4 '-(4 "-alkoxy-3"-
Chlorphenylcarbonyloxy) phenyl] ethane
[I] was obtained in 91-95% yield. The structure of each compound is
Confirmed by IR and NMR spectrum data.

The results are shown in Table 8 together with the phase transition temperatures of the respective compounds obtained in Examples 7 and 8.

[0062]

[Table 8]

Embodiment 91- (p-alkoxyphenyl)
) -2- {4 '-[p-alkoxy (or alkyl)
Phenyloxycarbonyl] phenyldiethane [Ie]
Synthesis (when X = H) The 4- [p-alkoxy (or alkyl) phen of Example 7
3. Nylcarbonyloxy] -4'-alkoxytolan
4- [p-Alkoxy obtained in Example 3 instead of 4 mmol
[(Alkyl) phenyloxycarbonyl] -4 '
-Except using 4.4 mmol of alkoxytran
And synthesized under the same conditions as in Example 7.
Coxyphenyl) -2- {4 '-[p-alkoxy (also
Is alkyl) phenyloxycarbonyl) phenyl
Tan [I] was obtained in 90-98% yield. Structure of each compound
The structure was confirmed by IR and NMR spectrum data.

[0064]

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Example 10 1- (p-Alkoxyphenyl)
2-)-4 '-(4 "-alkoxy-3" -chloro
Phenyloxycarbonyl) phenyldiethane [Ie]
Synthesis of (when X = Cl) 4- [p-Alkoxy (or alkyl) phenylcarbonyloxy] -4'-alkoxytolan of Example 7
4- (4 "-alkoxy-3" -chlorophenyloxycarbonyl) -4 'obtained in Example 4 instead of 4 mmol
-Synthesis was performed under the same conditions as in Example 7 except that 4.4 mmol of alkoxytran was used, and 1- (p-alkoxyphenyl) -2- {4 '-(4 "-alkoxy-
3 ″ -Chlorophenyloxycarbonyl) phenyl diethane [I] was obtained in a yield of 93 to 98%. The structure of each compound was confirmed by IR and NMR spectral data.

Table 9 shows the results together with the phase transition temperatures of the respective compounds obtained in Examples 9 and 10.

[0067]

[Table 9]

Example 11 p-Alkoxy (or alkyl)
Ru) phenyl 6-β- (p-alkoxyphenyl) d
3. Synthesis of tylnicotinate [If] (when X = H) 4- [p-Alkoxy (or alkyl) phenylcarbonyloxy] -4' -alkoxytolan of Example 7
The synthesis was performed under the same conditions as in Example 7 except that 4.4 mmol of the p-alkoxy (or alkyl) phenyl-6- (p-alkoxyphenyl) ethynylnicotinate obtained in Example 5 was used instead of 4 mmol. P-alkoxy (or alkyl) phenyl 6-β- (p-alkoxy) ethyl nicotinate [I] was obtained in a yield of 91 to 95%. The structure of each compound was confirmed by IR and NMR spectrum data.

Example 12 4'-Alkoxy-3'-k
Lorphenyl 6-β- (p-alkoxyphenyl) d
3. Synthesis of tylnicotinate [If] (when X = Cl) 4- [p-Alkoxy (or alkyl) phenylcarbonyloxy] -4' -alkoxytolan of Example 7
4'-Alkoxy- obtained in Example 6 instead of 4 mmol
3′-Chlorophenyl 6- (p-Alkoxyphenyl) ethynyl nicotinate Synthesized under the same conditions as in Example 7 except that 4.4 mmol was used.
Alkoxy-3'-chlorophenyl 6-β- (p-alkoxyphenyl) ethyl nicotinate [I]
Obtained in 95% yield. The structure of each compound is IR and NMR
Confirmed by spectral data.

Table 10 shows the results together with the phase transition temperatures of the compounds obtained in Examples 11 and 12.

[0071]

[Table 10]

Example 13 4-ethyl-4'-cyanobiphenyl 20% 4-pentyl-4'-cyanobiphenyl 40% 4-octyloxy-4'-cyanobiphenyl 25% 4-pentyl-4'-cyanobiterphenyl A 15% nematic liquid crystal composition is coated with polyvinyl alcohol (PVA), its surface is rubbed, a parallel alignment treatment is performed, and the liquid crystal composition is injected into a cell having a transparent electrode in which the electrode interval is controlled to 10 μm, to thereby form a TN type display. When a cell was formed and observed under a polarizing microscope, it was observed that a reverse twist domain was generated.

Next, the above-mentioned nematic liquid crystal composition is added to the optically active liquid crystal compound of the present invention, that is,

[0074]

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When 1% of the compound represented by the formula (1) was added and observed in a TN-type cell in the same manner, the reverse twisted
Domains were eliminated and a homogeneous nematic phase was observed.

[0076]

The reverse twist domain can be erased by adding the optically active compound of the present invention to a nematic liquid crystal composition for a TN display element. Further, since many of the compounds of the present invention have a wide temperature range showing a smectic C phase, a smectic liquid crystal composition having a wide temperature range showing ferroelectricity can be obtained by adding a ferroelectric smectic liquid crystal or an optically active compound. Such effects are achieved by the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C09K 19/20 9279-4H C09K 19/20 19/34 9279-4H 19/34 G02F 1/13 500 G02F 1/13 500

Claims (2)

(57) [Claims] 1. A compound of the general formula [I] (Wherein, R ¹ represents a linear alkyl group or a linear alkoxy group having 1 to 20 carbon atoms, R ² represents an optically active alkoxy group having an asymmetric carbon atom having 1 to 20 carbon atoms, and Y represents 2] And Z is And Q is And X represents a hydrogen atom or a halogen atom, respectively). 2. A compound of the general formula [I] (Wherein, R ¹ represents a linear alkyl group or a linear alkoxy group having 1 to 20 carbon atoms, R ² represents an optically active alkoxy group having an asymmetric carbon atom having 1 to 20 carbon atoms, and Y represents 6] And Z is And Q is And X represents a hydrogen atom or a halogen atom, respectively).