JPH10120600A - New alkenyltolane derivative - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new compound having large refractive index anisotropy and high upper limit temperature of nematic phase and having small viscosity as a tricyclic compound and capable of effectively using as a material for nematic liquid crystal display. SOLUTION: This compound is represented by formula I [R is a 1-10C alkyl; a ring A is (fluorine-substituted) 1,4-phenylene or trans-1,4-cyclohexylene; (m) is an integer of 2-6; R' is H or a 1-5C alkyl; when R' is an alkyl, double bond has cis (Z) configuration or trans (E) configuration]. The compound includes e.g. a compound of formula II. The compound of formula I is obtained by reacting, e.g. an alkenylbenzene derivative of formula III (X is Br, I, Cl, etc.) with a phenylacetylene derivative of formula IV in the presence of a catalyst. A liquid crystal composition having low viscosity and large refractive index anisotropy and wide liquid crystal temperature range can be obtained by adding the compound of formula I to a host liquid crystal composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an alkenyl tolan derivative, a novel liquid crystal compound, and a liquid crystal composition containing the same. These are useful as materials for electro-optical liquid crystal display, particularly as materials for nematic liquid crystal display.

[0002]

2. Description of the Related Art Liquid crystal display elements have been used in various measuring instruments, such as watches and calculators, automobile panels, word processors, electronic organizers, printers, computers, televisions, and the like. Typical liquid crystal display methods are TN (twisted nematic) type and S type.
TN (super twisted nematic) type, DS (dynamic light scattering) type,
There are GH (guest / host) type or FLC (ferroelectric liquid crystal) type, and the driving method is multiplex driving instead of conventional static driving, and simple matrix method, recently active matrix method is practical. Has been

[0003] In accordance with these display methods and drive methods, various characteristics are required as liquid crystal materials. Above all, high-speed response is very important in most cases. The physical properties required of the liquid crystal material in order to increase the response speed are directly (i) decreasing the viscosity or (i)
i) To increase the elastic constant. However,
When the elastic constant is increased, the threshold voltage often increases. Therefore, when low voltage driving is required, it is necessary to reduce the viscosity without increasing the elastic constant too much.

Further, as a means for increasing the response speed of the liquid crystal element, it is very effective to reduce the cell thickness. However, in a liquid crystal element, the product (Δnd) of the cell thickness (d) and the refractive index anisotropy (Δn) is set to a certain value (0.
5, 1.0, 1.6, 2.2, usually the former are often used. ) Must be set. Therefore, to reduce the cell thickness, a liquid crystal material having a large refractive index anisotropy (Δn) is required.

It is also very important for a liquid crystal material to exhibit a wide temperature range. However, in general, compounds having low viscosity often have low liquid crystallinity, so that in order to obtain a liquid crystal composition having low viscosity and a wide temperature range,
A liquid crystal compound having a high maximum nematic phase temperature (T _{N- I} ) and a low viscosity is also required.

[0006] From the above, in order to prepare a liquid crystal composition having a wide temperature range and capable of high-speed response, the refractive index anisotropy (Δn) is large, the nematic phase maximum temperature (T _NI ) is high, and Further, it is understood that a liquid crystal compound whose viscosity is not so large is necessary.

At present, as a liquid crystalline compound which satisfies these conditions relatively well, for example, a compound represented by the general formula (II):

[0008]

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(Wherein, R ^a and R ^b represent a straight-chain alkyl group). However, it is becoming difficult to meet the demand for improving the characteristics of liquid crystal materials accompanying the improvement in display quality even with the use of this, and liquid crystal compounds having more excellent characteristics are desired.

By using an alkenyl group having a double bond in place of the side chain alkyl group in the liquid crystal compound, the above-mentioned effects (decrease in viscosity, increase in Δn, increase in T
_NI rise). However, it is not easy to introduce an alkenyl group into the side chain of the tolan derivative, and thus no specific compound has been known.

[0011]

The object of the present invention is to provide a liquid crystal compound having a very large Δn, a high T _NI and a small viscosity as a tricyclic compound in order to meet the above objects. A novel alkenyl tolan derivative, which is further provided with a low viscosity and refractive index anisotropy (Δ
It is to provide a liquid crystal composition having a large n) and a wide liquid crystal temperature range.

[0012]

The present invention has been made in order to solve the above problems. General formula (I)

[0013]

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(Wherein, R represents an alkyl group having 1 to 10 carbon atoms, and ring A represents 1,4 or
-Represents a phenylene group or a trans-1,4-cyclohexylene group, m represents an integer of 2 to 6, and R 'represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Also,
When R 'is an alkyl group, the double bond is in a cis (Z) configuration or a trans (E) configuration. ). 2. 1 above wherein m = 2 in the general formula (I)
A compound as described. 3. 3. A liquid crystal composition comprising the compound according to 1 or 2 above. As the above-mentioned solution.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the present invention will be described below. In the general formula (I), R represents 1 to 1 carbon atoms.
It represents 10 alkyl groups, preferably a linear alkyl group having 1 to 7 carbon atoms, and particularly preferably a linear alkyl group having 1 to 5 carbon atoms. Ring A represents a 1,4-phenylene group or a trans-1,4-cyclohexylene group which may be substituted with fluorine, but a 1,4-phenylene group, a 2-fluoro-1,4-phenylene group or a trans- 1,4-
A cyclohexylene group is preferred, and 2-fluoro-1,4
-A phenylene group or a trans-1,4-cyclohexylene group is particularly preferred. m represents an integer of 2 to 6,
An even number of 4 or 6 is preferred, and 2 is most preferred.
R ′ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, but if the side chain is too long, the viscosity increases, so that a hydrogen atom or a methyl group is preferable. When R ′ is an alkyl group, the configuration of the double bond is preferably trans (E).

The compound of the general formula (I) can be produced, for example, as follows. That is, the general formula (III)
a)

[0017]

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An alkenylbenzene derivative represented by the general formula (IVb)

[0019]

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It can be easily produced by reacting with a phenylacetylene derivative represented by the following formula in the presence of a catalyst. In the above formula, X is a bromine atom, an iodine atom,
It represents a leaving group such as a chlorine atom, a p-toluenesulfonyl group, a methanesulfonyl group or a trifluoromethanesulfonyl group, but a bromine atom or an iodine atom is preferred from the viewpoint of ease of production and reactivity of the compound of the general formula (IIIa). . Further, R, ring A, m and R ′ have the same meaning as in general formula (I).

As the catalyst, it is effective and preferable to use a palladium catalyst and a copper (I) compound, particularly copper (I) iodide in combination. The reaction is performed in a solvent, and dimethylformamide (DMF), dimethylacetamide (D
So-called aprotic polar solvents such as MA) and dimethyl sulfoxide (DMSO) are preferred, and usually an amine-based solvent such as triethylamine is used in combination.

Alternatively, the compound of the general formula (I) has the general formula (IIIb)

[0023]

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A phenylacetylene derivative represented by the general formula (Iva)

[0025]

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The compound can be easily produced by reacting the alkenylbenzene derivative represented by the above formula in the same manner. In the above formula, Y represents a leaving group such as a bromine atom, an iodine atom, a chlorine atom, a p-toluenesulfonyl group, a methanesulfonyl group or a trifluoromethanesulfonyl group. A bromine atom or an iodine atom is preferred from the viewpoint of reactivity and reactivity. Further, R, ring A, m and R ′ have the same meaning as in general formula (I).

The general formula (I) of the present invention thus produced
Table 1 shows the phase transition temperatures of typical compounds represented by the following formulas.

[0028]

[Table 1]

(In the table, Cr represents a crystal phase, N represents a nematic phase, and I represents an isotropic liquid phase, and the phase transition temperature is “° C.”.) The compound of the present invention is contained in a liquid crystal composition. The excellent effects obtained by adding the compound to are as follows.

In the compounds represented by the general formula (I) of the present invention, ring A is a representative compound representing a trans-1,4-cyclohexylene group, m = 2 and R = H in Table 1 No. (I-1)

[0031]

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20% by weight of the compound (A) and the host liquid crystal composition (H)

[0033]

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Liquid crystal composition (M-1) consisting of 80% by weight
Was prepared. Here, the physical property values of the host liquid crystal composition (H) are as follows. T _NI : 54.5 ° C. Viscosity (20 ° C.): 21.0 cp Response time (τr = τd): 39.2 ms Refractive index anisotropy (Δn): 0.092 Here, viscosity is a measured value at 20 ° C. The response time is a measured value at the time of applying a voltage at which the rise time (τr) and the fall time (τd) are equal.

On the other hand, the physical properties of (M-1) were as follows. T _NI : 85.4 ° C. Viscosity (20 ° C.): 22.1 cp Response time (τr = τd): 41.1 ms Refractive index anisotropy (Δn): 0.132 Thus, the general formula (I) of the present invention ), The T _NI increases by about 31 ° and the refractive index anisotropy (Δ
It can be seen that n) has increased by 40% or more. Nevertheless, the viscosity has increased by only 5%,
Response time also increased by only about 5%.

On the other hand, the compound represented by the general formula (II) represented by the general formula (II) having a structure similar to that of the general formula (I) (similarly having a tolan structure, but having both straight-chain alkyl groups).
-1)

[0037]

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20% by weight of the compound (A) and a host liquid crystal (H)
A composition (MR-1) consisting of 80% by weight was prepared.
Physical properties of (MR-1) were as follows. T _NI : 83.0 ° C. Viscosity (20 ° C.): 22.3 cp Response time (τr = τd): 45.8 ms Refractive index anisotropy (Δn): 0.131 The physical property value of (MR-1) is as follows. Compared with (M-1) of the present invention, the viscosity and the refractive index anisotropy (Δn) hardly change, but the response time and the maximum temperature of the nematic phase (T _NI ) reach (M-1). It turns out there is no.

Therefore, No. 1 represented by the general formula (I) of the present invention. The compound of formula (I-1) is used for obtaining a liquid crystal composition having low viscosity, excellent responsiveness, large refractive index anisotropy, and a wide nematic phase temperature range.
It is clear that the compound exhibits an effect superior to the compound of I-1).

Similarly, in the compound represented by the general formula (I) of the present invention, the ring A is a representative compound representing a 2-fluoro-1,4-phenylene group, m = 2, and R = H. No. 1 in Table 1. (I-2)

[0041]

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20% by weight of the compound (A) and a host liquid crystal (H)
A liquid crystal composition (M-2) consisting of 80% by weight was prepared.
Physical properties of this (M-2) were as follows. T _NI : 77.5 ° C. Viscosity (20 ° C.): 24.1 cp Response time (τr = τd): 53.6 ms Refractive index anisotropy (Δn): 0.147 Compared with (M-1) Then, the T _NI is slightly lower and the viscosity and the response time are slightly inferior, but the refractive index anisotropy (Δn) is further increased and is increased by about 60% as compared with the host liquid crystal (H). I understand.

Accordingly, the compound of the general formula (I) of the present invention, when mixed with another nematic liquid crystal compound, has a T
It can be suitably used for an N-type or STN-type field effect type display cell, particularly as a material having low viscosity and high response speed. In addition, since the compound of the general formula (I) does not have a strong polar group in the molecule, it is easy to obtain a large specific resistance and a high voltage holding ratio. Is also possible.

The present invention also provides a liquid crystal composition containing at least one compound represented by the general formula (I) as a constituent. Preferable typical examples of the nematic liquid crystal compound which can be used as a mixture with the compound of the general formula (I) of the present invention in this composition include, for example, 4-substituted phenyl 4-substituted benzoic acid and 4-substituted benzoic acid 4-substituted phenyl cyclohexanecarboxylate, 4-substituted biphenylyl 4-substituted cyclohexanecarboxylate, 4-substituted phenyl 4- (4-substituted cyclohexanecarbonyloxy) benzoate, 4-substituted 4- (4-substituted cyclohexyl) benzoate Phenyl, 4- (4-
(Substituted cyclohexyl) benzoic acid 4-substituted cyclohexyl, 4,4'-substituted biphenyl, 1- (4-substituted cyclohexyl) -4-substituted benzene, 4,4'-substituted bicyclohexane, 1- [2- (4-substituted Cyclohexyl) ethyl] -4-substituted benzene, 1- (4-substituted cyclohexyl) -2- (4-substituted cyclohexyl) ethane, 4,
4 "-substituted terphenyl, 4- (4-substituted cyclohexyl) -4'-substituted biphenyl, 4- [2- (4-substituted cyclohexyl) ethyl] -4'-substituted biphenyl, 4-
(4-substituted phenyl) -4′-substituted bicyclohexane,
4- [2- (4-substituted cyclohexyl) ethyl] -4 ′
-Substituted biphenyl, 4- [2- (4-substituted cyclohexyl) ethyl] cyclohexyl-4'-substituted benzene,
-[2- (4-substituted phenyl) ethyl] -4'-substituted bicyclohexane, 1- (4-substituted phenylethynyl)-
4-substituted benzene, 1- (4-substituted phenylethynyl)
-4- (4-substituted cyclohexyl) benzene, 2- (4
-Substituted phenyl) -5-substituted pyrimidine, 2- (4'-
Examples include (substituted biphenylyl) -5-substituted pyrimidine and compounds in which the benzene ring in each of the above compounds has a lateral substituent.

Among them, 4,4'-substituted biphenyl, 1- (4-substituted cyclohexyl) -4-substituted benzene, 4,4'-substituted bicyclohexane, 1- [2- (4- Substituted cyclohexyl)
Ethyl] -4-substituted benzene, 1- (4-substituted cyclohexyl) -2- (4-substituted cyclohexyl) ethane,
4,4 "-substituted terphenyl, 4- (4-substituted cyclohexyl) -4'-substituted biphenyl, 4- [2- (4-substituted cyclohexyl) ethyl] -4'-substituted biphenyl,
4- (4-substituted phenyl) -4'-substituted bicyclohexane, 4- [2- (4-substituted cyclohexyl) ethyl]-
4'-substituted biphenyl, 4- [2- (4-substituted cyclohexyl) ethyl] cyclohexyl-4'-substituted benzene, 4- [2- (4-substituted phenyl) ethyl] -4'-
Substituted bicyclohexane, 1- (4-substituted phenylethynyl) -4-substituted benzene, 1- (4-substituted phenylethynyl) -4- (4-substituted cyclohexyl) benzene and compounds in which the benzene ring is fluorine-substituted Is suitable.

[0046]

EXAMPLES Examples of the present invention are shown below to further explain the present invention. However, the invention is not limited to these examples.

The structure of the compound was confirmed by a nuclear magnetic resonance spectrum (NMR), a mass spectrum (MS) and an infrared absorption spectrum (IR). In addition, "%" of the composition
Represents "% by weight". Reference Example 1 Synthesis of 4-iodo-1- (3-butenyl) benzene 16.4 g of magnesium was suspended in 20 mL of dry THF. To this 4-bromo-1- (3-butenyl)
A solution of 150 g of benzene in 600 mL of THF was added dropwise at a rate at which the solvent continued to gently reflux. After completion of the dropwise addition, the mixture was stirred for 2 hours and allowed to cool to room temperature. 162 g of iodine in THF4
It was dissolved in 80 mL and added dropwise at 10 ° C. for 1 hour. After completion of the dropwise addition, the mixture was stirred for 1 hour, added with water and then with an aqueous solution of sodium hydrogen sulfite, and extracted with toluene. Water the organic layer,
Then, it was washed with saturated saline and dried over anhydrous sodium sulfate. The crude product obtained by distilling off the solvent was purified using silica gel column chromatography (hexane) to give 4-iodo-1- (3-butenyl) benzene 171.
g was obtained. Reference Example 2 Synthesis of 1- (3-butenyl) -4-ethynylbenzene 86.4 g of 4-iodo-1- (3-butenyl) benzene obtained in Reference Example 1, dichlorobis (triphenylphosphine) palladium (II) ) 2.35 g and copper (I) iodide 637
mg of DMF (120 mL) and triethylamine (90 m).
L. A solution of 42.2 g of 2-methyl-3-butyn-2-ol in 60 mL of DMF was added dropwise at 30 ° C. or lower, and the mixture was further stirred at room temperature for 2 hours.

[0048] Dilute hydrochloric acid and toluene were added, the aqueous layer was extracted with toluene, and the organic layers were combined and washed with water and then with saturated saline. After dehydration and drying with anhydrous sodium hydrogen sulfate, the solvent was distilled off under reduced pressure to obtain 73.7 g of a crude product of 4- [4- (3-butenyl) phenyl] -2-methyl-3-butyn-2-ol. Obtained.

670 mg of sodium hydroxide was added to the whole amount, and the mixture was stirred at 80 ° C. for 2 hours while distilling off the generated acetone. Distillation under reduced pressure (165 ° C./15 mmHg) gave 19.3- (3-butenyl) -4-ethynylbenzene 39.3.
g was obtained. Example 1 Synthesis of 1- [4- (trans-4-propylcyclohexyl) phenyl] -2- [4- (3-butenyl) phenyl] ethyne (I-1)

[0050]

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19.1 g of 1- (trans-4-propylcyclohexyl) -4-iodobenzene was added to DMF120.
dissolved in 20 ml of triethylamine and 400 ml of dichlorobistriphenylphosphine palladium (II).
And 100 mg of copper (I) iodide, and the mixture was stirred. To this, 10 g of 1- (3-butenyl) -4-ethynylbenzene obtained in Reference Example 2 was added dropwise at 30 ° C. or lower over 2 hours, and the mixture was further stirred at room temperature for 2 hours. Water and 10% hydrochloric acid were added, the aqueous layer was separated, extracted with toluene, the organic layers were combined, and 10% hydrochloric acid,
Washed with water and then with saturated saline. After dehydration and drying with anhydrous sodium sulfate, the solvent is distilled off to give 1- [4- (trans-4-propylcyclohexyl) phenyl] -2-.
Crude crystal of [4- (3-butenyl) phenyl] ethyne 2
1.3 g were obtained. This was purified using silica gel column chromatography (hexane), and further recrystallized from ethanol to obtain 15.8 g of a purified product. This compound was crystalline at room temperature and had a melting point of 91 ° C, and showed a nematic phase up to 214 ° C.

The following compounds were obtained in the same manner. 1- [4- (trans-4-methylcyclohexyl) phenyl] -2- [4- (3-butenyl) phenyl] ethyne 1- [4- (trans-4-ethylcyclohexyl) phenyl] -2- [4- (3-butenyl) phenyl] ethyne 1- [4- (trans-4-butylcyclohexyl) phenyl] -2- [4- (3-butenyl) phenyl] ethyne 1- [4- (trans-4-pentylcyclohexyl)
Phenyl] -2- [4- (3-butenyl) phenyl] ethyne 1- [4- (trans-4-methylcyclohexyl) phenyl] -2- [4- (trans-3-pentenyl) phenyl] ethyne 1- [ 4- (trans-4-ethylcyclohexyl) phenyl] -2- [4- (trans-3-pentenyl) phenyl] ethyne 1- [4- (trans-4-propylcyclohexyl)
Phenyl] -2- [4- (trans-3-pentenyl)
Phenyl] ethyne 1- [4- (trans-4-butylcyclohexyl) phenyl] -2- [4- (trans-3-pentenyl) phenyl] ethyne 1- [4- (trans-4-pentylcyclohexyl)
Phenyl] -2- [4- (trans-3-pentenyl)
Phenyl] ethyne 1- [4- (trans-4-methylcyclohexyl) phenyl] -2- [4- (trans-3-hexenyl) phenyl] ethyne 1- [4- (trans-4-ethylcyclohexyl) phenyl]- 2- [4- (trans-3-hexenyl) phenyl] ethyne 1- [4- (trans-4-propylcyclohexyl)
Phenyl] -2- [4- (trans-3-hexenyl)
Phenyl] ethyne 1- [4- (trans-4-butylcyclohexyl) phenyl] -2- [4- (trans-3-hexenyl) phenyl] ethyne 1- [4- (trans-4-pentylcyclohexyl)
Phenyl] -2- [4- (trans-3-hexenyl)
Phenyl] ethyne 1- [4- (trans-4-methylcyclohexyl) phenyl] -2- [4- (5-hexenyl) phenyl] ethyne 1- [4- (trans-4-ethylcyclohexyl) phenyl] -2- [4- (5-Hexenyl) phenyl] ethyne 1- [4- (trans-4-propylcyclohexyl)
Phenyl] -2- [4- (5-hexenyl) phenyl]
Ethyne 1- [4- (trans-4-butylcyclohexyl) phenyl] -2- [4- (5-hexenyl) phenyl] ethyne 1- [4- (trans-4-pentylcyclohexyl)
Phenyl] -2- [4- (5-hexenyl) phenyl]
Ethine (Reference Example 3) Synthesis of 2-fluoro-4-propyl-4'-ethynylbiphenyl 23.7 g of anhydrous aluminum chloride was added to dichloromethane 70
The solution was dissolved in mL, and 15.1 g of acetyl chloride was added dropwise at room temperature, and the mixture was further stirred for 1 hour, and then cooled with ice to adjust the internal temperature to 5 ° C or lower. This is followed by 2-fluoro-4-propylbiphenyl 3
A solution of 1.7 g of dichloromethane in 100 mL was prepared at an internal temperature of 10 mL.
The mixture was added dropwise at a rate not exceeding ℃, and the mixture was further stirred for 2 hours. Pour the reaction solution into vigorously stirred ice water and separate the organic layer.
Washed with water and saturated saline. After dehydration and drying with anhydrous sodium sulfate, the solvent was distilled off to obtain 38 g of 2-fluoro-4-propyl-4′-acetylbiphenyl.

The whole amount was dissolved in 100 mL of dichloromethane, and the solution was added dropwise to 40.2 g of phosphorus pentachloride suspended in 50 mL of dichloromethane at room temperature, followed by further stirring for 8 hours. The reaction solution was cooled to room temperature with a 10% aqueous sodium hydroxide solution 5
After dropping into 00 mL and stirring for 1 hour, the organic layer was separated,
It was dehydrated and dried with anhydrous sodium sulfate. After distilling off the solvent,
It was dissolved in 150 mL of THF, and a solution of 33.3 g of potassium t-butoxide in 100 mL of THF was added dropwise at room temperature. After stirring under reflux for 1 hour, the mixture was allowed to cool to room temperature,
Poured into 200 mL of 10% hydrochloric acid. The organic layer was separated and the solvent was distilled off. The aqueous layer was extracted with 200 mL of ethyl acetate and combined with the concentrated liquid of the organic layer. After washing with water and saturated saline,
It was dehydrated and dried with anhydrous sodium sulfate. After distilling off the solvent,
Purification was performed using silica gel column chromatography (hexane) to obtain 22 g of 2-fluoro-4-propyl-4′-ethynylbiphenyl. (Example 2) 2-fluoro-4-propyl-4'-
Synthesis of [4- (3-butenyl) phenyl] ethynylbiphenyl (I-2)

[0054]

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2-fluoro-4-propyl-4′-ethynylbiphenyl obtained in Reference Example 3 and 4-fluoro-4-propyl-4'-ethynylbiphenyl obtained in Reference Example 1
From iodo-1- (3-butenyl) benzene, 2-fluoro-4-propyl-4- [4-
(3-Butenyl) phenyl] ethynylbiphenyl was obtained. This compound is crystalline at room temperature and has a melting point of 82.5.
° C and showed a nematic phase up to 184 ° C.

The following compounds were obtained in the same manner. 2-fluoro-4-methyl-4 '-[4- (3-butenyl) phenyl] ethynylbiphenyl 2-fluoro-4-ethyl-4'-[4- (3-butenyl) phenyl] ethynylbiphenyl 2-fluoro- 4-butyl-4 '-[4- (3-butenyl) phenyl] ethynylbiphenyl 2-fluoro-4-pentyl-4'-[4- (3-butenyl) phenyl] ethynylbiphenyl 2-fluoro-4-methyl- 4 '-[4- (trans-
3-pentenyl) phenyl] ethynylbiphenyl 2-fluoro-4-ethyl-4 ′-[4- (trans-
3-Pentenyl) phenyl] ethynylbiphenyl 2-fluoro-4-propyl-4 '-[4- (trans-3-pentenyl) phenyl] ethynylbiphenyl 2-fluoro-4-butyl-4'-[4- (trans-
3-Pentenyl) phenyl] ethynylbiphenyl 2-fluoro-4-pentyl-4 '-[4- (trans-3-pentenyl) phenyl] ethynylbiphenyl 2-fluoro-4-methyl-4'-[4- (trans-
3-hexenyl) phenyl] ethynylbiphenyl 2-fluoro-4-ethyl-4 '-[4- (trans-
3-hexenyl) phenyl] ethynylbiphenyl 2-fluoro-4-propyl-4 ′-[4- (trans-3-hexenyl) phenyl] ethynylbiphenyl 2-fluoro-4-butyl-4 ′-[4- (trans-
3-hexenyl) phenyl] ethynylbiphenyl 2-fluoro-4-pentyl-4 ′-[4- (trans-3-hexenyl) phenyl] ethynylbiphenyl 2-fluoro-4-methyl-4 ′-[4- (5- [Hexenyl) phenyl] ethynylbiphenyl 2-fluoro-4-ethyl-4 '-[4- (5-hexenyl) phenyl] ethynylbiphenyl 2-fluoro-4-propyl-4'-[4- (5-hexenyl) phenyl] Ethynylbiphenyl 2-fluoro-4-butyl-4 '-[4- (5-hexenyl) phenyl] ethynylbiphenyl 2-fluoro-4-pentyl-4'-[4- (5-hexenyl) phenyl] ethynylbiphenyl 3- Fluoro-4-methyl-4 '-[4- (3-butenyl) phenyl] ethynylbiphenyl 3-fluoro-4-ethyl 4 '-[4- (3-butenyl) phenyl] ethynylbiphenyl 3-fluoro-4-butyl-4'-[4- (3-butenyl) phenyl] ethynylbiphenyl 3-fluoro-4-pentyl-4 '-[ 4- (3-butenyl) phenyl] ethynylbiphenyl 3-fluoro-4-methyl-4 ′-[4- (trans-
3-pentenyl) phenyl] ethynylbiphenyl 3-fluoro-4-ethyl-4 ′-[4- (trans-
3-Pentenyl) phenyl] ethynylbiphenyl 3-fluoro-4-propyl-4 ′-[4- (trans-3-pentenyl) phenyl] ethynylbiphenyl 3-fluoro-4-butyl-4 ′-[4- (trans-
3-Pentenyl) phenyl] ethynylbiphenyl 3-fluoro-4-pentyl-4 ′-[4- (trans-3-pentenyl) phenyl] ethynylbiphenyl 3-fluoro-4-methyl-4 ′-[4- (trans-
3-hexenyl) phenyl] ethynylbiphenyl 3-fluoro-4-ethyl-4 ′-[4- (trans-
3-hexenyl) phenyl] ethynylbiphenyl 3-fluoro-4-propyl-4 ′-[4- (trans-3-hexenyl) phenyl] ethynylbiphenyl 3-fluoro-4-butyl-4 ′-[4- (trans-
3-hexenyl) phenyl] ethynylbiphenyl 3-fluoro-4-pentyl-4 ′-[4- (trans-3-hexenyl) phenyl] ethynylbiphenyl 3-fluoro-4-methyl-4 ′-[4- (5- [Hexenyl) phenyl] ethynylbiphenyl 3-fluoro-4-ethyl-4 '-[4- (5-hexenyl) phenyl] ethynylbiphenyl 3-fluoro-4-propyl-4'-[4- (5-hexenyl) phenyl] Ethynylbiphenyl 3-fluoro-4-butyl-4 '-[4- (5-hexenyl) phenyl] ethynylbiphenyl 3-fluoro-4-pentyl-4'-[4- (5-hexenyl) phenyl] ethynylbiphenyl 2, 3-difluoro-4-methyl-4 ′-[4- (3-
(Butenyl) phenyl] ethynylbiphenyl 2,3-difluoro-4-ethyl-4 ′-[4- (3-
(Butenyl) phenyl] ethynylbiphenyl 2,3-difluoro-4-butyl-4 ′-[4- (3-
(Butenyl) phenyl] ethynylbiphenyl 2,3-difluoro-4-pentyl-4 ′-[4- (3
-Butenyl) phenyl] ethynylbiphenyl 4- [4- (3-butenyl) phenyl] ethynyl-4 ′
-Methylbiphenyl 4- [4- (3-butenyl) phenyl] ethynyl-4 ′
-Ethylbiphenyl 4- [4- (3-butenyl) phenyl] ethynyl-4 ′
-Propylbiphenyl 4- [4- (3-butenyl) phenyl] ethynyl-4 ′
-Butylbiphenyl 4- [4- (3-butenyl) phenyl] ethynyl-4 ′
-Pentylbiphenyl 4- [4- (trans-3-pentenyl) phenyl] ethynyl-4'-methylbiphenyl 4- [4- (trans-3-pentenyl) phenyl] ethynyl-4'-ethylbiphenyl 4- [4- (Trans-3-pentenyl) phenyl] ethynyl-4'-propylbiphenyl 4- [4- (trans-3-pentenyl) phenyl] ethynyl-4'-butylbiphenyl 4- [4- (trans-3-pentenyl) phenyl ] Ethynyl-4'-pentylbiphenyl 4- [4- (trans-3-hexenyl) phenyl] ethynyl-4'-methylbiphenyl 4- [4- (trans-3-hexenyl) phenyl] ethynyl-4'-ethylbiphenyl 4- [4- (trans-3-hexenyl) phenyl] ethynyl-4′-propylbiphenyl 4- 4- (trans-3-hexenyl) phenyl] ethynyl-4'-butylbiphenyl 4- [4- (trans-3-hexenyl) phenyl] ethynyl-4'-pentylbiphenyl 4- [4- (5-hexenyl) phenyl Ethynyl-
4'-methylbiphenyl 4- [4- (5-hexenyl) phenyl] ethynyl-
4'-ethylbiphenyl 4- [4- (5-hexenyl) phenyl] ethynyl-
4'-propylbiphenyl 4- [4- (5-hexenyl) phenyl] ethynyl-
4'-butylbiphenyl 4- [4- (5-hexenyl) phenyl] ethynyl-
4′-Pentylbiphenyl (Example 3) Preparation of liquid crystal composition (1) General-purpose host liquid crystal (H)

[0057]

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Was prepared. This host liquid crystal (H) is 5
A nematic phase was exhibited at 4.5 ° C. or lower, and the viscosity, response time at that time, and refractive index anisotropy (Δn) were as follows. Viscosity (20 ° C.): 21.0 cp Response time (τr = τd): 39.2 ms Refractive index anisotropy (Δn): 0.092 Here, viscosity is a measured value at 20 ° C., and response time is 20
This is a measured value at the time of voltage application in which the rise time (τr) and the fall time (τd) at ° C. become equal.

This host liquid crystal (H) 80% and Example 1
(I-1) in Table 1 obtained in

[0060]

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A nematic liquid crystal composition (M-1) consisting of 20% of the compound was prepared. The characteristic values of (M-1) were as follows. T _NI : 85.4 ° C. Viscosity (20 ° C.): 22.1 cp Response time (τr = τd): 41.1 ms Refractive index anisotropy (Δn): 0.132 Thus, (M− In 1), T _NI increases by about 31 °, and the refractive index anisotropy (Δn) increases by 40% or more. Nevertheless, the viscosity has increased by only 5% and the response time has also increased by only about 5%. Therefore, in the case of the present invention, It can be seen that the compound (I-1) is extremely effective for obtaining a nematic liquid crystal composition having a wide temperature range up to a high temperature range, a large refractive index anisotropy and a small viscosity. (Comparative Example 1) On the other hand, a compound represented by the general formula (II) having a structure similar to that of the general formula (I) (similarly having a tran skeleton, but both side chains are linear alkyl groups) I
I-1)

[0062]

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Compound 20% and host liquid crystal (H) 80
% Of the composition (MR-1) was as follows. T _NI : 83.0 ° C. Viscosity (20 ° C.): 22.3 cp Response time (τr = τd): 45.8 ms Refractive index anisotropy (Δn): 0.131 This is the physical property value of (M-1). Compared with, there is almost no change in the viscosity and the refractive index anisotropy (Δn),
It can be seen that the response time is about 10% slower than (M-1) and lower than (M-1) even in the maximum nematic phase temperature (T _NI ). Accordingly, in the case of No. 2 of the present invention. (I-1)
It is clear that the compound of formula (II-1) exhibits an effect superior to that of the compound of formula (II-1) in obtaining a liquid crystal composition having low viscosity, excellent responsiveness, large refractive index anisotropy and a wide nematic phase temperature range. It is. (Example 4) Preparation of liquid crystal composition (2) Host liquid crystal (H) 80% and No. 1 in Table 1 obtained in Example 2 (I-2)

[0064]

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A nematic liquid crystal composition (M-2) consisting of 20% of the compound was prepared. The characteristic value of (M-2) was as follows. T _NI : 77.5 ° C. Viscosity (20 ° C.): 24.1 cp Response time (τr = τd): 53.6 ms Refractive index anisotropy (Δn): 0.147 Compared with (M-1) Then, the T _NI is slightly lower, and the viscosity and response time are slightly inferior. However, it can be seen that the refractive index anisotropy (Δn) is further increased and is increased by about 60% as compared with the host liquid crystal (H).

[0066]

As described in Examples, the alkenyl tolan derivatives provided by the present invention can be easily produced industrially. The obtained alkenyl tolan derivative has a higher maximum temperature of the nematic phase and an excellent effect of improving its responsiveness as compared with a conventionally used tricyclic tolan derivative compound having a similar or similar skeleton. The composition is extremely useful as a practical liquid crystal, particularly for a liquid crystal display requiring a high-speed response over a wide temperature range.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G02F 1/13 500 G02F 1/13 500

Claims (3)

[Claims] 1. A compound of the general formula (I) (Wherein, R represents an alkyl group having 1 to 10 carbon atoms,
Ring A represents a 1,4-phenylene group or a trans-1,4-cyclohexylene group which may be substituted with fluorine,
m represents an integer of 2 to 6, and R 'represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. When R ′ is an alkyl group, the double bond has a cis (Z) configuration or a trans (E) configuration. ). 2. The compound according to claim 1, wherein m = 2 in the general formula (I). 3. A liquid crystal composition containing the compound according to claim 1.