CN110407803A - A kind of benzothiophene polymerizable compound and its application - Google Patents

Abstract

The invention belongs to the technical field of liquid crystal materials, and specifically relates to a benzothiophene polymerizable compound and an application thereof. The compound has a structure represented by general formula I. Compared with the prior art, the compound of the present invention has good solubility, better alignment effect, faster polymerization rate, more complete polymerization, and lower residue, thereby greatly improving the problem of poor display. The liquid crystal composition containing this compound has lower viscosity, can realize rapid response, has moderate dielectric anisotropy Δ ￡ simultaneously, and the liquid crystal display element or liquid crystal display that comprises this liquid crystal composition has wider nematic phase temperature range, suitable or higher birefringence anisotropy △n, higher resistivity, good UV resistance, high charge retention and low vapor pressure.

Description

A kind of benzothiophene polymerizable compound and its application

technical field

The invention belongs to the technical field of liquid crystal materials, and relates to a benzothiophene polymerizable compound and an application thereof.

Background technique

In recent years, liquid crystal display devices have been widely used in various electronic devices such as smartphones, tablet computers, car navigation systems, televisions, and the like. Representative liquid crystal display modes include twisted nematic (TN) type, super twisted nematic (STN) type, in-plane switching (IPS) type, fringe field switching (FFS) type and vertical alignment (VA) type. Among them, the VA mode has attracted more and more attention due to its fast fall time, high contrast, wide viewing angle, and high-quality images.

However, the liquid crystal medium used in the display elements of the active matrix addressing mode such as VA mode has its own shortcomings, such as the afterimage level is obviously worse than that of the display elements with positive dielectric anisotropy, the response time is relatively slow, and the driving voltage is relatively low. higher. In order to solve the above problems, some new VA display technologies have emerged, such as MVA technology, PVA technology, and PSVA technology. Among them, PSVA technology not only realizes the wide viewing angle display mode similar to MVA/PVA, but also simplifies the CF process, realizes the reduction of CF cost, improves the aperture ratio, and can obtain higher brightness, and then obtain higher contrast. In addition, since the entire liquid crystal has a pre-tilt angle, there is no domino delay phenomenon, and a faster response time can be obtained while maintaining the same driving voltage, and the afterimage level will not be affected.

It has been found in the prior art that LC mixtures and RMs still have some disadvantages for their application in PSA displays. Firstly, not every soluble RM desired so far is suitable for use in PSA displays: at the same time, if one wishes to polymerize by means of UV light without adding photoinitiators (which may be advantageous for some applications) , the selection becomes even smaller: In addition, the "material system" formed by combining the LC mixture (hereinafter also referred to as "LC host mixture") with the selected polymerizable components should have the lowest rotational viscosity and the best optoelectronic properties , used to increase the "Voltage Hold Ratio" (VHR) to achieve the effect. In terms of PSVA, it is very important to use high VHR after (UV) light irradiation, otherwise it will cause problems such as afterimage in the final display. So far, due to the problem that the UV sensitive wavelength of the polymerizable unit is too short, or there is no or insufficient tilt angle after irradiation, or the uniformity of the polymerizable component is poor after irradiation. Not all combinations of LC mixtures and polymerizable components are suitable for PSVA displays.

Therefore, the synthesis of polymeric compounds with novel structures and the study of their structure-property relationship has become an important task in the field of liquid crystals.

Contents of the invention

The first object of the present invention is to provide a benzothiophene polymerizable compound. Compared with the prior art, the polymerizable liquid crystal compound of the present invention has good solubility, better alignment effect, and faster polymerization rate , the polymerization is more complete and the residue is lower, thus greatly improving the problem of poor display.

The liquid crystal composition containing this compound has lower viscosity, can realize rapid response, has moderate dielectric anisotropy Δ ￡ simultaneously, and the liquid crystal display element or liquid crystal display that comprises this liquid crystal composition has wider nematic phase temperature range, suitable or higher birefringence anisotropy △n, higher resistivity, good UV resistance, high charge retention and low vapor pressure.

The liquid crystal compound described in the present invention has the following structure:

Wherein, the P ₁ , P ₂ , and P ₃ independently represent an acrylate group, a methacrylate group, a fluoroacrylate group, a chloroacrylate group, a vinyloxy group, an oxetanyl group, or a ring Oxygen;

The Z ₁ , Z ₂ , and Z ₃ independently represent a single bond, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, - CH=N-, -N=CH-, -N=N-, C ₁ -C ₁₂ alkylene or C ₂ -C ₁₂ alkenyl, wherein the C ₁ -C ₁₂ alkylene or One or more hydrogen atoms in a C ₂ -C ₁₂ alkenyl group may be independently substituted by F, Cl, or CN, and one or more non-adjacent -CH ₂ - groups may be independently substituted by -O-, -S-, -NH-, -CO-, COO-, -OCO-, -OCOO-, -SCO-, -COS- or -C=C- are replaced in a manner that is not directly connected to each other;

The ring A and ring B independently represent 1,4-cyclohexylene or 1,4-phenylene;

The L ₁ , L ₂ , and L ₃ independently represent -F, -Cl, -CN, -NO ₂ , -CH ₃ , -C ₂ H ₅ , -C(CH ₃ ) ₃ , -CH(CH ₃ ) ₂ , -CH ₂ CH(CH ₃ )C ₂ H ₅ , -OCH ₃ , -OC ₂ H ₅ , -COCH ₃ , -COC ₂ H ₅ , -COOCH ₃ , -COOC ₂ H ₅ , -CF ₃ , -OCF ₃ , -OCHF ₂ or -OC ₂ F ₅ ;

r ₁ , r ₂ , r ₃ independently represent 0, 1, 2 or 3;

m represents 0 or 1.

In general formula I, regarding P ₁ , P ₂ , P ₃ : preferably, P ₁ , P ₂ , P ₃ independently represent methacrylate, acrylate, fluoroacrylate or chloroacrylic acid Ester group;

More preferably, P ₁ , P ₂ , P ₃ independently represent a methacrylate group or an acrylate group.

About Z ₁ , Z ₂ , Z ₃ :

Preferably, Z ₁ , Z ₂ , and Z ₃ independently represent a single bond, -O-, -S-, -CO-O-, -O-CO-, C ₁ -C ₆ alkylene or C ₂ -C ₆ alkenyl, wherein one or more hydrogen atoms in the C ₁ -C ₆ alkylene or C ₂ -C ₆ alkenyl can be independently substituted by F, and one or more Two non-adjacent -CH ₂ - groups can be independently replaced by -O- in a manner that is not directly connected to each other;

More preferably, Z ₁ , Z ₂ , Z ₃ independently represent a single bond, -O-, C ₁ -C ₆ alkylene or alkoxy.

About L ₁ , L ₂ :

Preferably, said L ₁ , L ₂ , and L ₃ independently represent -F, -Cl, -CH ₃ , -C ₂ H ₅ , -OCH ₃ , -OC ₂ H ₅ , -CF ₃ or OCF ₃ ;

More preferably, L ₁ and L ₂ represent -F, -Cl, -CH ₃ , -OCH ₃ , -C ₂ H ₅ , -OC ₂ H ₅ .

About _L3 :

Preferably, L ₃ represents one of -F, -Cl, -CH ₃ , -C ₂ H ₅ , -OCH ₃ , -OC ₂ H ₅ , -CF ₃ or OCF ₃ ;

More preferably, L3 represents F or _Cl .

About r ₁ , r ₂ , r ₃ :

Preferably, r ₁ , r ₂ , r ₃ independently represent 0, 1 or 2; more preferably, r ₃ represents 0 or 1.

Among the compounds described in the present invention, preferably, in the general formula I, P ₁ , P ₂ , and P ₃ independently represent a methacrylate group, an acrylate group, a fluoroacrylate group or a chloroacrylate group ;

The Z ₁ , Z ₂ , and Z ₃ independently represent a single bond, -O-, -S-, -CO-O-, -O-CO-, C ₁ -C ₆ alkylene or C ₂ - C ₆ alkenyl, wherein one or more hydrogen atoms in the C ₁ -C ₆ alkylene or C ₂ -C ₆ alkenyl can be independently substituted by F, and one or more Non-adjacent -CH ₂ - groups can be replaced independently of each other by -O- in a manner that is not directly connected to each other;

The ring A and ring B independently represent 1,4-cyclohexylene or 1,4-phenylene;

The L ₁ , L ₂ , and L ₃ independently represent -F, -Cl, -CH ₃ , -C ₂ H ₅ , -OCH ₃ , -OC ₂ H ₅ , -CF ₃ or OCF ₃ ;

r ₁ , r ₂ , r ₃ independently represent 0, 1 or 2;

m represents 0 or 1.

Further preferably, in the general formula I, P ₁ , P ₂ , and P ₃ independently represent a methacrylate group or an acrylate group;

The Z ₁ , Z ₂ , and Z ₃ independently represent a single bond, -O-, C ₁ -C ₆ alkylene or alkoxy;

The ring A and ring B independently represent 1,4-cyclohexylene or 1,4-phenylene;

L ₁ and L ₂ represent -F, -Cl, -CH ₃ , -OCH ₃ , -C ₂ H ₅ , -OC ₂ H ₅ ;

L ₃ represents F or Cl;

r ₁ , r ₂ , r ₃ independently represent 0, 1 or 2.

m means 0 or 1;

As a further preferred technical scheme of the present invention, in the compound:

When m=0 and ring A is 1,4-cyclohexylene, L ₁ , L ₂ , and L ₃ independently represent -F or -Cl;

Or, when m=1, ring A is 1,4-cyclohexylene, and ring B is 1,4-phenylene, r ₃ represents 0;

Or, when m=1, ring A and ring B are both 1,4-cyclohexylene, r ₁ =r ₂ =0;

or, when r ₁ and/or r ₂ represent 2, r ₃ represents 0;

Or, when L ₂ represents one of -CH ₃ , -OCH ₃ , -C ₂ H ₅ , -OC ₂ H ₅ , and r ₂ is not 0, r ₃ represents 0;

Or, when ring A is 1,4-phenylene, r ₁ +r ₂ +r ₃ ≤4.

As the most preferred technical scheme of the present invention, the compound is selected from one of the following compounds:

As the best embodiment of the present invention, the compound is selected from one of the following compounds:

The second object of the invention is to protect the composition containing said liquid crystal compound. Preferably, the mass percentage of the compound in the composition is 0.01-10%, more preferably 0.01-5%, even more preferably 0.1-3%.

The third object of the present invention is to protect the application of the liquid crystal compound and the composition containing the liquid crystal compound in the field of liquid crystal display, preferably in liquid crystal display devices. The liquid crystal display devices include but are not limited to TN, ADS, VA, PSVA, FFS or IPS liquid crystal displays. The composition using the liquid crystal compound or containing the liquid crystal compound has a wide nematic phase temperature range, suitable or high birefringence anisotropy Δn, high resistivity, and good UV resistance performance, high charge retention, and low vapor pressure.

Detailed ways

The following examples are used to illustrate the present invention, but not to limit the scope of the present invention. All other equivalent changes or modifications that do not deviate from the spirit disclosed in the present invention should be included in the scope of the claims.

The liquid crystal compounds used in the following examples, unless otherwise specified, can be synthesized by known methods or obtained from public commercial sources. These synthesis techniques are conventional, and the obtained liquid crystal compounds are tested to be in line with electronic compounds. standard.

According to conventional detection methods in this field, various performance parameters of the liquid crystal compound are obtained by linear fitting, wherein, the specific meanings of each performance parameter are as follows:

Δn represents optical anisotropy (25°C); Δε represents dielectric anisotropy (25°C, 1000Hz); γ1 represents rotational viscosity (mPa.s, 25°C); Cp represents clearing point.

Example 1

The structural formula of the liquid crystal compound is:

The synthetic route for preparing compound BYLC-01 is as follows:

Specific steps are as follows:

(1) Synthesis of compound BYLC-01-1:

Add 45.0g Y-1, 34.2g 3,5-dihydroxybiphenylboronic acid, 16.0g anhydrous potassium carbonate, 200ml toluene, 150ml ethanol, 150ml water, 0.3g tetrakistriphenylphosphine palladium to the reaction flask, heat to reflux After 8 hours of reaction, conventional post-treatment was carried out to obtain 56.5 g of off-white solid (compound BYLC-01-1), HPLC: 99.5%, yield 85.2%;

(2) Synthesis of compound BYLC-01-2:

Add 56.5g of compound BYLC-01-1, 8.0g of NaOH, 200ml of deionized water, and 200ml of ethanol into the reaction flask, and react at 65°C to 70°C for 2h. After acidification with hydrochloric acid, conventional post-treatment was carried out to obtain a white solid (compound BYLC-01-2), 53.4g, HPLC: 99.6%, yield 92.6%

(3) Synthesis of compound BYLC-01:

Under the protection of nitrogen, add 53.4g of compound BYLC-01-2, 35.5g of triethylamine and 300mL of dichloromethane into the reaction flask, cool down to -10°C, and add 36.8g of methpropylene dropwise at -10°C to 0°C Acyl chloride, raised to room temperature and reacted for 6 hours, poured the reaction solution into water, neutralized it with aqueous uranium bicarbonate solution, performed conventional post-treatment, purified by chromatography, eluted with n-hexane, and recrystallized from ethanol to obtain 69.2 g of a white solid (Compound BYLC-01) , LC: 99.5%, Yield: 80.5%.

The obtained white solid BYLC-01 was analyzed by GC-MS, and the m/z of the product was 538.1 (M+).

1H-NMR (300MHz, CDCl3): 1.55-2.15 (m, 9H), 5.35-6.55 (m, 6H), 6.65-7.95 (m, 11H).

Example 2

The structural formula of the liquid crystal compound is:

The synthetic route for preparing compound BYLC-02 is as follows:

Specific steps are as follows:

Synthesis of compound BYLC-02:

Under the protection of nitrogen, add 42.0g of compound BYLC-01-2, 31.0g of triethylamine and 250mL of dichloromethane into the reaction flask, cool down to -10°C, and add 27.0g of acryloyl chloride dropwise at -10°C to 0°C, Rise to room temperature and react for 6 hours. Pour the reaction liquid into water, neutralize it with aqueous uranium bicarbonate solution, perform conventional post-treatment, and purify by chromatography, eluting with n-hexane, and recrystallizing from ethanol to obtain 53.3 g of a white solid (Compound BYLC-02), LC : 99.7%, yield: 85.6%.

The obtained white solid BYLC-02 was analyzed by GC-MS, and the m/z of the product was 496.1 (M+).

1H-NMR (300MHz, CDCl3): 5.15-5.75 (m, 3H), 5.85-6.85 (m, 8H), 7.05-7.95 (m, 9H).

Example 3

The structural formula of the liquid crystal compound is:

by replace Other reaction conditions are with embodiment 1.

The obtained white solid BYLC-03 was analyzed by GC-MS, and the m/z of the product was 574.1 (M+).

1H-NMR (300MHz, CDCl3): 1.55-2.15 (m, 7H), 5.35-6.55 (m, 6H), 6.65-7.95 (m, 11H).

Example 4

The structural formula of the liquid crystal compound is:

by replace Other reaction conditions are with embodiment 1.

The obtained white solid BYLC-04 was analyzed by GC-MS, and the m/z of the product was 556.1 (M+).

1H-NMR (300MHz, CDCl3): 1.55-2.15 (m, 8H), 5.35-6.55 (m, 6H), 6.65-7.95 (m, 11H).

Example 5

The structural formula of the liquid crystal compound is:

by replace Other conditions are with embodiment 1.

The obtained white solid BYLC-05 was analyzed by GC-MS, and the m/z of the product was 556.1 (M+).

1H-NMR (300MHz, CDCl3): 1.55-2.15 (m, 8H), 5.35-6.55 (m, 6H), 6.65-7.95 (m, 11H).

Example 6

The structural formula of the liquid crystal compound is:

by replace Other reaction conditions are with embodiment 1.

The obtained white solid BYLC-06 was analyzed by GC-MS, and the m/z of the product was 538.1 (M+).

1H-NMR (300MHz, CDCl3): 1.55-2.15 (m, 7H), 5.35-6.55 (m, 8H), 6.65-7.95 (m, 11H).

Example 7

The structural formula of the liquid crystal compound is:

by replace Other conditions are with embodiment 1.

The obtained white solid BYLC-07 was analyzed by GC-MS, and the m/z of the product was 552.1 (M+).

1H-NMR (300MHz, CDCl3): 1.55-2.15 (m, 8H), 5.35-6.55 (m, 8H), 6.65-7.95 (m, 11H).

Example 8

The structural formula of the liquid crystal compound is:

The obtained white solid BYLC-08 was analyzed by GC-MS, and the m/z of the product was 598.1 (M+).

1H-NMR (300MHz, CDCl3): 1.55-2.15 (m, 9H), 5.35-6.85 (m, 14H), 7.05-7.95 (m, 7H).

Example 9

The structural formula of the liquid crystal compound is:

by replace Other reaction conditions are with embodiment 1.

The obtained white solid BYLC-09 was analyzed by GC-MS, and the m/z of the product was 462.1 (M+).

1H-NMR (300MHz, CDCl3): 1.55-2.15(m, 9H), 5.35-6.85(m, 8H), 7.05-7.95(m, 5H).

Example 10

The structural formula of the liquid crystal compound is:

The obtained white solid BYLC-10 was analyzed by GC-MS, and the m/z of the product was 554.1 (M+).

1H-NMR (300MHz, CDCl3): 1.55-2.15(m, 9H), 2.35-4.15(m, 3H), 5.35-6.85(m, 6H), 7.05-7.95(m, 7H).

Example 11

The structural formula of the liquid crystal compound is:

The obtained white solid BYLC-11 was analyzed by GC-MS, and the m/z of the product was 552.1 (M+).

1H-NMR (300MHz, CDCl3): 1.55-2.15 (m, 12H), 5.35-6.55 (m, 6H), 6.65-7.95 (m, 9H).

Example 12

According to the technical solutions of the above embodiments, the following liquid crystal compounds can be synthesized by simply replacing the corresponding raw materials without changing any substantive operations.

Example 13

The properties of the liquid crystal mixture BHR87800 are listed in Table 1:

Table 1 Summary of properties of mixed crystal BHR87800

Among them, the mixture BHR87800 was purchased from Bayi Space-Time Liquid Crystal Technology Co., Ltd. Add 0.3% of the polymerizable compound BYLC-01 provided in Example 1 to the 99.7% liquid crystal composition BHR87800, and dissolve it uniformly to obtain the mixture PM-1.

Add 0.3% of the polymerizable compound BYLC-02 provided in Example 2 to the 99.7% liquid crystal composition BHR87800, and dissolve it uniformly to obtain the mixture PM-2.

Add 0.3% of the polymerizable compound BYLC-06 provided in Example 6 to the 99.7% liquid crystal composition BHR87800, and dissolve it uniformly to obtain the mixture PM-3.

Add 0.3% of the polymerizable compound BYLC-07 provided in Example 7 to the 99.7% liquid crystal composition BHR87800, and dissolve it uniformly to obtain the mixture PM-4.

The physical properties of PM-1, PM-2, PM-3, and PM-4 were almost the same as those of the above-mentioned mixture BHR87800. PM-1, PM-2, PM-3, and PM-4 were injected into test cells with a gap of 4.0 μm and vertical alignment using a vacuum infusion method. While applying a square wave with a frequency of 60HZ and a driving voltage of 16V, a high-pressure mercury ultraviolet lamp is used to irradiate ultraviolet rays to the test box, adjust the irradiation intensity on the surface of the box to 30mW/cm2, and irradiate for 600s to obtain a vertically aligned liquid crystal display after polymerization For components, use LCT-5016E liquid crystal photoelectric parameter tester to measure the pretilt angle, then decompose the test box, and use high performance liquid chromatography (HPLC) to measure the residual polymeric compound in the liquid crystal composition. The results are summarized in Table 2 and Table 3.

comparative example

0.3% of the polymerizable compound of CP was added to 99.7% liquid crystal composition BHR87800, and it was dissolved uniformly, and the mixture PM-5 was obtained. The physical properties of PM-5 were almost the same as those of the above-mentioned mixture BHR87800. PM-5 was injected into a test cell with a gap of 4.0 μm and a vertical alignment using a vacuum infusion method. While applying a square wave with a frequency of 60HZ and a driving voltage of 16V, a high-pressure mercury ultraviolet lamp is used to irradiate ultraviolet rays to the test box, adjust the irradiation intensity on the surface of the box to 30mW/cm2, and irradiate for 600s to obtain a vertically aligned liquid crystal display after polymerization For components, use LCT-5016E liquid crystal photoelectric parameter tester to measure the pretilt angle, then decompose the test box, and use high performance liquid chromatography (HPLC) to measure the residual polymeric compound in the liquid crystal composition. The results are summarized in Table 2 and Table 3.

Table 2 Summary of UV front and rear pretilt angles

Table 3 Summary of polymer residue data

From the comparative data in Table 2 and Table 3, it can be seen that compared with the polymerizable liquid crystal compound CP, the polymeric compound of the present invention has a better alignment effect, faster polymerization rate, more complete polymerization, and lower residue, so that the larger The problem of poor display has been improved.

Although, the present invention has been described in detail with general description, specific implementation and test above, but on the basis of the present invention, some modifications or improvements can be made to it, which will be obvious to those skilled in the art . Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (10)

1. a kind of benzothiophene kind can poly- property compound, which is characterized in that have structure shown in general formula I:

Wherein, the P₁、P₂、P₃Acrylate-based, methacrylate, fluoropropenes acid ester group, chlorine are indicated independently of one another For acrylate-based, ethyleneoxy, oxetanyl or epoxy group；

The Z₁、Z₂、Z₃Singly-bound ,-O- ,-S- ,-CO- ,-CO-O- ,-O-CO- ,-O-CO-O- ,-CH=are indicated independently of one another N- ,-N=CH- ,-N=N-, C₁-C₁₂Alkylidene or C₂-C₁₂Alkenyl, wherein the C₁-C₁₂Alkylidene or C₂-C₁₂'s One or more hydrogen atoms in alkenyl can be replaced by F, Cl or CN independently of one another, and it is one or more it is non-conterminous- CH₂Group can be independently of one another by-O- ,-S- ,-NH- ,-CO-, COO- ,-OCO- ,-OCOO- ,-SCO- ,-COS- or-C= C- is replaced in a manner of not being connected directly mutually；

The ring A and ring B indicates 1,4- cyclohexylidene or 1,4- phenylene independently of one another；

The L₁, L₂, L₃Expression-F ,-Cl ,-CN ,-NO independently of one another₂、-CH₃、-C₂H₅、-C(CH₃)₃、-CH(CH₃)₂、- CH₂CH(CH₃)C₂H₅、-OCH₃、-OC₂H₅、-COCH₃、-COC₂H₅、-COOCH₃、-COOC₂H₅、-CF₃、-OCF₃、-OCHF₂Or- OC₂F₅；

The r₁、r₂、r₃0,1,2 or 3 are indicated independently of one another；

The m indicates 0 or 1.

2. compound according to claim 1, which is characterized in that P₁、P₂、P₃Methacrylate is indicated independently of one another Base, acrylate-based, fluoropropenes acid ester group or chloropropene perester radical；

Preferably, P₁、P₂、P₃Methacrylate or acrylate-based is indicated independently of one another.

3. compound according to claim 1 or 2, which is characterized in that Z₁、Z₂、Z₃Independently of one another indicate singly-bound ,-O- ,- S-、-CO-O-、-O-CO-、C₁-C₆Alkylidene or C₂-C₆Alkenyl, wherein the C₁-C₆Alkylidene or C₂-C₆Alkene One or more hydrogen atoms in base can be replaced by F independently of one another, and one or more non-conterminous-CH₂Group can be with It is replaced in a manner of not being connected directly mutually by-O- independently of one another；

Preferably, Z₁、Z₂、Z₃Singly-bound ,-O-, C are indicated independently of one another₁-C₆Alkylidene or alkoxy.

4. compound according to claim 1-3, which is characterized in that the L₁, L₂Independently of one another expression-F ,- Cl、-CH₃、-C₂H₅、-OCH₃、-OC₂H₅、-CF₃Or OCF₃；

Preferably, L₁、L₂Expression-F ,-Cl ,-CH independently of one another₃、-OCH₃、-C₂H₅Or-OC₂H₅。

5. compound according to claim 1-4, which is characterized in that the L₃Expression-F ,-Cl ,-CH₃、- C₂H₅、-OCH₃、-OC₂H₅、-CF₃Or OCF₃One of；

Preferably, L₃Indicate F or Cl.

6. compound according to claim 1-5, which is characterized in that the r₁、r₂、r₃It indicates independently of one another 0,1 or 2；

Preferably, the r₃Indicate 0 or 1.

7. compound according to claim 1-6, which is characterized in that in general formula I:

Work as m=0, when ring A is 1 or 4 cyclohexylidene, L₁、L₂、L₃Expression-F or-Cl independently of one another；

Or, work as m=1, ring A is 1 or 4 cyclohexylidene, and when ring B is Isosorbide-5-Nitrae-phenylene, r₃Indicate 0；

Or, work as m=1, and when ring A and ring B are 1 or 4 cyclohexylidene, r₁=r₂=0；

Or, working as r₁And/or r₂When indicating 2, r₃Indicate 0；

Or, working as L₂Expression-CH₃、-OCH₃、-C₂H₅、-OC₂H₅One of, and r₂When not being 0, r₃Indicate 0；

Or, when ring A is Isosorbide-5-Nitrae-phenylene, r₁+r₂+r₃≤4。

8. compound according to claim 1-7, which is characterized in that one kind selected from following compound:

Preferably, selected from one of following compound:

9. a kind of liquid-crystal composition, which is characterized in that contain the described in any item compounds of claim 1-8；

Preferably, the mass percent of the compound in the composition be 0.01~10%, more preferably 0.01~ 5%, further preferably 0.1~3%.

10. the described in any item compounds of claim 1-8 and/or composition as claimed in claim 9 are in field of liquid crystal display Application, the application preferably in liquid crystal display device；The more preferably described liquid crystal display device include TN, ADS, VA, PSVA, FFS or IPS liquid crystal display.