Compound, liquid crystal medium containing the compound and application thereof

Abstract

The present invention discloses a compound of which a structural formula thereof is represented as the following formula: ##STR00001##
The compound disclosed by the present invention can be used as a liquid crystal compound and overcomes the problem that solubility of the traditional dibenzothiophene-class liquid crystals is poor, and thus can be better applied to the liquid crystal material field. The present invention further discloses a liquid crystal medium containing the compound and an application thereof.

Claims

1. A liquid crystal medium containing one or more of the compounds having a following formula I: ##STR00180## wherein: R represents one of a cyclopropyl group, a cyclopentyl group, and a 2-tetrahydrofuryl group; Z represents one of a single bond, —O—, —CH.sub.2CH.sub.2—, —CH.sub.2O—, —CF.sub.2O—, and —COO—; and X represents one of H, F, an alkyl group having 1-7 carbon atoms, and an alkoxygroup having 1-7 carbon atoms, wherein in the alkyl group having 1-7 carbon atoms and the alkoxygroup having 1-7 carbon atoms, one or more H atoms can be substituted by F, wherein the liquid crystal medium further comprises one or more compounds of the following formulas IV1 to IV15: ##STR00181## ##STR00182## wherein: R2 and R3 respectively and independently represent any one group in the following groups represented by (1)-(3): (1) a linear alkyl group having 1-7 carbon atoms or a linear alkoxygroup having 1-7 carbon atoms; (2) a group formed by substituting —O—, —COO—, —OOC—, or —CH═CH— for one or more —CH2—in anyone group represented by (1); and (3) a group formed by substituting F, Cl, —CH═CH.sub.2, or —CH═CH—CH.sub.3 for one or more H atoms in anyone group represented by (1); ##STR00183## respectively and independently represent any one group in the following groups: ##STR00184## and wherein in formula IV4, ##STR00185## are not both ##STR00186##

2. The liquid crystal medium according to claim 1, wherein the liquid crystal medium further comprises one or more compounds of which a structural formula is formula V: ##STR00187## wherein: R.sub.4 and R.sub.5 respectively and independently represent an alkyl group having 1-10 carbon atoms or an alkenyl group having 2-10 carbon atoms, in which any —CH.sub.2— can be substituted by —CH.sub.2O—, —OCH.sub.2—, or —C═C—, and any H atom can be substituted by F; ##STR00188## respectively and independently represent the following groups: ##STR00189## p, q, and r respectively and independently represent 0 or 1; and Z.sub.4, Z.sub.5, and Z.sub.6 respectively and independently represent one of a single bond, —C.sub.2H.sub.4—, —CH═CH—, —COO—, —OOC—, —CH.sub.2O—, —OCH.sub.2—, —CF.sub.2O—, and —OCF.sub.2—, in which any H atom can be substituted by F.

3. The liquid crystal medium according to claim 2, wherein in the liquid crystal medium, a mass percentage of the compound of which the structural formula is formula I being 1-24%, a mass percentage of the compound of which the structural formula is formula IV being 35-58%, and a mass percentage of the compound of which the structural formula is formula V being 30-46%.

4. The liquid crystal medium according to claim 2, wherein the structural formula of the compound of which the structural formula is formula V being specifically represented as the following formulas V1 to V16: ##STR00190## ##STR00191## wherein: R.sub.4 and R.sub.5 respectively and independently represent an alkyl group having 1-10 carbon atoms or an alkenyl group having 2-10 carbon atoms, in which any —CH.sub.2— can be substituted by —CH.sub.2O—, —OCH.sub.2—, or —C═C—, any H atom can be substituted by F; and (F) respectively and independently represents F or H.

5. A liquid crystal display device comprising the liquid crystal medium according to claim 1.

6. The liquid crystal medium according to claim 3, wherein the structural formula of the compound of which the structural formula is formula V being specifically represented as the following formulas V1 to V16: ##STR00192## ##STR00193## wherein: R.sub.4 and R.sub.5 respectively and independently represent an alkyl group having 1-10 carbon atoms or an alkenyl group having 2-10 carbon atoms, in which any —CH.sub.2— can be substituted by —CH.sub.2O—, —OCH.sub.2—, or —C═C—, any H atom can be substituted by F; and (F) respectively and independently represents F or H.

7. A method of preparing a liquid crystal mixture, a material for a liquid crystal display device, or a material for an electro-optical display device, the method comprising administering the liquid crystal medium according to claim 1.

8. A method of preparing a liquid crystal mixture, a material for a liquid crystal display device, or a material for an electro-optical display device, the method comprising administering the liquid crystal medium according to claim 2.

9. A method of preparing a liquid crystal mixture, a material for a liquid crystal display device, or a material for an electro-optical display device, the method comprising administering the liquid crystal medium according to claim 3.

10. A method of preparing a liquid crystal mixture, a material for a liquid crystal display device, or a material for an electro-optical display device, the method comprising administering the liquid crystal medium according to claim 4.

11. An electro-optical display device comprising the liquid crystal medium according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The specific embodiments of the present invention are further described below with reference to the drawings.

(2) FIG. 1 shows a mass spectrogram of a compound of formula I12-2 according to embodiment 4.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(3) In order to more clearly describe the present invention, the present invention is further described below with reference to the preferred embodiments and the drawings. The similar components in the drawings are represented by the same drawing number. A person skilled in the art should understand that the following specific description content is for description instead of for limitation, and the protection scope of the present invention shall not limited thereto.

(4) In the present invention, all the preparation methods, if not specifically described, are conventional methods; all the used raw materials, if not specifically described, can be obtained via a public commercial approach; and all the percentages, if not specifically described, are mass percentages.

(5) In the present invention, a specific meaning of each symbol and a test condition are as follows:

(6) GC represents gas chromatographic purity, MP represents a melting point, CP represents a clearing point, MS represents a mass spectrum, Δε represents dielectric anisotropy, and Δn represents optical anisotropy.

(7) Methods for measuring GC, MP, CP, MS, Δε, and Δn are all conventional methods.

Embodiment 1

(8) For a compound of which a structural formula is formula I1-1:

(9) ##STR00028##

(10) a preparation method thereof is as follows.

(11) Step 1:

(12) ##STR00029##

(13) 36.3 g (0.14 mol) of 2-fluoro-6-bromo-3-cyclopentylphenol, 22.6 g (0.14 mol) of 2,3-difiuorophenylboronic acid, 43 g (0.31 mol) of potassium carbonate, 300 ml of methylbenzene, and 100 ml of pure water are added into a 1 L three-necked flask and mixed for total dissolution, 0.05 g of Pd-132 is added under the protection of nitrogen, and the mixture is heated at reflux for 6 h; after the reaction stops, 400 ml of pure water is added to and mixed with the mixture for liquid separation, a water layer is extracted by using 200 ml×2 of methylbenzene, organic layers are merged and washed by using 400 ml×2 of saturated salt solution, a solvent is spin-dried in reduced pressure, 80 g of petroleum ether is added to and mixed well with an obtained liquid, and recrystallization is performed in a temperature of −20° C. to obtain a white solid (1-a) with a mass of 33 g, GC of 98.5%, and a yield coefficient of 80.6%.

(14) Step 2:

(15) ##STR00030##

(16) 33 g (0.11 mol) of (1-a), 21.5 g (0.17 mol) of Dimethylcarbamothioic chloride, 22.2 g (0.22 mol) of triethylamine, and 300 ml of dichloromethane are added into a 1 L three-necked flask and mixed for 6 h in a room temperature for a reaction; after the reaction stops, 400 ml of pure water is added to and mixed with the mixture for liquid separation, a water layer is extracted by using 200 ml×2 of dichloromethane, organic layers are merged and washed by using 400 ml×2 of saturated sodium bicarbonate solution, a solvent is spin-dried in reduced pressure after being dried by using anhydrous sodium sulfate, 100 g of petroleum ether is added to and mixed well with an obtained liquid, and recrystallization is performed in a temperature of −20° C. to obtain a white solid (1-b) with a mass of 35 g, GC of 98.0%, and a yield coefficient of 83%.

(17) Step 3:

(18) ##STR00031##

(19) 35 g (0.092 mol) of (1-b) and 300 ml of methylbenzene are added into a 1 L three-necked flask and mixed for total dissolution. 0.94 g of Pd(PtBu.sub.3).sub.2 is added under the protection of nitrogen, and the mixture is heated to 100° C. for a reaction of 4 h; after the reaction stops, 400 ml of pure water is added to and mixed with the mixture for liquid separation, a water layer is extracted by using 200 ml×2 of methylbenzene, organic layers are merged and washed by using 400 ml×2 of saturated salt solution, a solvent is spin-dried in reduced pressure, 100 g of petroleum ether is added to and mixed well with an obtained liquid, and recrystallization is performed in a temperature of −20° C. to obtain a white solid (1-c) with a mass of 30 g, GC of 99.1%, and a yield coefficient of 86%.

(20) Step 4:

(21) ##STR00032##

(22) 30 g (0.08 mol) of (1-c) is added into a 500 ml three-necked flask, 200 ml of dimethyl sulfoxide (DMSO) is added under the protection of nitrogen for well mixing, 8.8 g (0.22 mol) of 60% sodium hydride mineral oil is added, and the mixture is heated to 100° C. for stirring of 4 h; after the reaction stops, the mixture is cooled to a room temperature, a reaction liquid is poured into 300 g of ice water for stirring to separate out a large amount of solids, suction filtration is performed by using a filter cloth to obtain a solid, the solid is aired and heated to total dissolution after 200 ml of petroleum ether is added thereto, then chromatography with 30 g of hot silica column is performed, the column is flushed by using 200 ml of hot petroleum ether, a solution is spin-dried, methylbenzene and petroleum ether of the same amount with the solution are added for heating to total dissolution, and recrystallization is performed for two times in a temperature of 0° C. to obtain a white solid (I1-1) with a mass of 15 g, GC of 99.92%, and a yield coefficient of 65%.

Embodiment 2

(23) For a compound of which a structural formula is formula 16-2:

(24) ##STR00033##

(25) a preparation route thereof is as follows.

(26) Step 1: a compound of the following formula 2-a is synthesized by using 2-fluoro-6-bromo-3-cyclopentylphenol and 2,3-difluoro-4-trifluoromethoxyphenylboronic acid as raw materials with reference to step 1 in embodiment 1:

(27) ##STR00034##

(28) Step 2:

(29) a compound of the following formula 2-b is synthesized by using the compound 2-a as a raw material with reference to the synthetic method in step 2 in embodiment 1:

(30) ##STR00035##

(31) Step 3:

(32) a compound of the following formula 2-c is synthesized by using the compound 2-b as a raw material with reference to step 3 in embodiment 1:

(33) ##STR00036##

(34) Step 4:

(35) the target compound, that is, the compound of which the structural formula is formula 16-2 is synthesized by using the compound 2-c as a raw material with reference to step 4 in embodiment 1:

(36) ##STR00037##

Embodiment 3

(37) For a compound of which a structural formula is the following formula I12-1:

(38) ##STR00038##

(39) a preparation route thereof is as follows.

(40) Step 1:

(41) a compound of the following formula 3-a is synthesized by using 2-fluoro-6-bromo-3-cyclopropylmethoxyphenol and 2,3-difluoro-4-ethoxylphenylboronic acid as raw materials with reference to step 1 in embodiment 1:

(42) ##STR00039##

(43) Step 2:

(44) a compound of the following formula 3-b is synthesized by using the compound 3-a as a raw material with reference to the synthetic method in step 2 in embodiment 1:

(45) ##STR00040##

(46) Step 3:

(47) a compound of the following formula 3-c is synthesized by using the compound 3-b as a raw material with reference to step 3 in embodiment 1:

(48) ##STR00041##

(49) Step 4:

(50) the target compound, that is, the compound of which the structural formula is formula. I12-1 is synthesized by using the compound 3-c as a raw material with reference to step 4 in embodiment 1:

(51) ##STR00042##

Embodiment 4

(52) For a compound of which a structural formula is the following formula I12-2:

(53) ##STR00043##

(54) a preparation route thereof is as follows.

(55) Step 1:

(56) a compound of the following formula 4-a is synthesized by using 2-fluoro-6-bromo-3-cyclopentylmethoxyphenol and 2,3-difluoro-4-butoxyphenylboronic acid as raw materials with reference to step 1 in embodiment 1:

(57) ##STR00044##

(58) Step 2:

(59) a compound of the following formula 4-b is synthesized by using the compound 4-a as a raw material with reference to the synthetic method in step 2 in embodiment 1:

(60) ##STR00045##

(61) Step 3:

(62) a compound of the following formula 4-c is synthesized by using the compound 4-b as a raw material with reference to step 3 in embodiment 1:

(63) ##STR00046##

(64) Step 4:

(65) the target compound, that is, the compound of which the structural formula is formula I12-2 is synthesized by using the compound 4-c as a raw material with reference to step 4 in embodiment 1:

(66) ##STR00047##

(67) A spectrum of the obtained compound of formula I12-2 is as shown in FIG. 1.

Embodiment 5

(68) For a compound of which a structural formula is the following formula I15-2:

(69) ##STR00048##

(70) a preparation route thereof is as follows.

(71) Step 1:

(72) a compound of the following formula 5-a is synthesized by using 2-fluoro-6-bromo-3-(2-tetrahydrofuran)ethylphenol and 2,3-difluoro-4-butoxyphenylboronic acid as raw materials with reference to step 1 in embodiment 1:

(73) ##STR00049##

(74) Step 2:

(75) a compound of the following formula 5-b is synthesized by using the compound 5-a as a raw material with reference to the synthetic method in step 2 in embodiment 1:

(76) ##STR00050##

(77) Step 3:

(78) a compound of the following formula 5-c is synthesized by using the compound 5-b as a raw material with reference to step 3 in embodiment 1:

(79) ##STR00051##

(80) Step 4:

(81) the target compound, that is, the compound of which the structural formula is formula I15-2 is synthesized by using the compound 5-c as a raw material with reference to step 4 in embodiment 1:

(82) ##STR00052##

Mixture Embodiment

Embodiments 6-13

(83) Embodiments 6-13 list preparation methods of different liquid crystal mediums, wherein a monomer structure and a dosage (weight percentage) of a specific compound in each embodiment, and a performance parameter test result of an obtained liquid crystal medium are respectively as shown in the following tables 1-8.

(84) The temperature unit involved in each embodiment is ° C. and specific meanings and test conditions of other symbols are as follows:

(85) S—N represents a melting point (° C.) for converting a liquid crystal from a crystalline state to a nematic phase;

(86) c.p. represents a clearing point (° C.) of the liquid crystal, wherein a test instrument is: Mettler-Toledo-FP System micro-thermal analyzer;

(87) γ.sub.1 is rotational viscosity (mPa.Math.s), wherein a test condition is as follows: 25° C., INSTEC: ALCT-IR1, and an 18-micrometer vertical box;

(88) K.sub.11 is twist elastic constant, K.sub.33 is a splay elastic constant, wherein a test condition is as follows: 25° C. INSTEC: ALCT-IR1, and an 18-micrometer vertical box;

(89) Δε represents dielectric anisotropy, Δε=.sub.ε.sub.//.sub.31 ε.sub.⊥.sup.Δε=ε.sup.//.sup.−ε.sup.⊥, wherein ε.sub.// is a dielectric constant of a direction parallel to a molecular axis, ε.sub.⊥ is a dielectric constant of a direction perpendicular to the molecular axis, and a test condition is as follows: 25° C., INSTEC: ALCT-IR1, and an 18-micrometer vertical box;

(90) Δn represents optical anisotropy, Δn=n.sub.o−n.sub.e, wherein n.sub.o is an ordinary Refractive index, n.sub.e is an extraordinary refractive index, and a test condition is as follows: 589 nm, and 25±0.2° C.

(91) In the present invention, compounds of formulas I, IV, and V are respectively and proportionally weighed out to prepare the liquid crystal medium, wherein devices and instruments used for the preparation of the liquid crystal medium are as follows:

(92) (1) an electronic precision balance (with accuracy of 0.1 mg);

(93) (2) a stainless steel beaker: used to weigh out a compound raw material;

(94) (3) a spoon: used to add a raw material;

(95) (4) a magnetic rotor: used for stirring;

(96) (5) a temperature-controlling electromagnetic stirrer.

(97) The preparation method of the liquid crystal medium includes the following steps:

(98) (1) the used raw materials are arranged orderly;

(99) (2) the stainless steel beaker is placed on the balance, and the compound of formula I is put into the stainless steel beaker by using the spoon;

(100) (3) other compound raw materials are sequentially added according to required weights thereof;

(101) (4) the stainless steel beaker which all of the materials are added is placed on the magnetic stirring instrument and heated to melt the mixture; and (5) after most of the mixture in the stainless steel beaker is melted, one magnetic rotor is added into the stainless steel beaker to stir the liquid crystal mixture for well mixing, and the liquid crystal medium is obtained after the mixture is cooled to a room temperature.

(102) The obtained liquid crystal medium are applied between two substrates of a liquid crystal display for performance test.

(103) TABLE-US-00001 TABLE 1 Component proportion and performance parameter of the liquid crystal medium in embodiment 6 Compound general Weight formula Liquid crystal structural formula percentage (%) Performance parameter V 8 S-N: ≤−40° C.; c.p: 80° C.; γ.sub.1: 110 mPa .Math. s; V 10 Δn: 0.091; n.sub.e: 1.573; Δε: −4.3; V 10 ε.sub.⊥: 8.3; K.sub.11/K.sub.33: 13.5/14.7; the liquid crystal medium V 5 does not crystallize after being placed in a temperature of −20° C. IV 9 for 480 h. IV 9 IV 8 IV 0 4 IV 3 IV 5 IV 5 IV 10 IV 2 I 5 I 7

(104) TABLE-US-00002 TABLE 2 Component proportion and performance parameter of the liquid crystal medium in embodiment 7 Compound general Weight formula Liquid crystal structural formula percentage (%) Performance parameter V 38 S-N: ≤−40° C.; c.p: 80° C.; γ.sub.1: 90 mPa .Math. s; V 3 Δn: 0.100; n.sub.e: 1.579; Δε: −3.8; IV 0 5 ε.sub.⊥: 8.0; K.sub.11/K.sub.33: 14.5/16.0; the liquid crystal medium does not crystallize IV 8 after being placed in a temperature of −20° C. for 480 h. IV 10 IV 10 IV 11 IV 6 I 4 I 5

(105) TABLE-US-00003 TABLE 3 Component proportion and performance parameter of the liquid crystal medium in embodiment 8 Compound general Weight formula Liquid crystal structural formula percentage (%) Performance parameter V 12 S-N: ≤−40° C.; c.p: 90° C.; γ.sub.1: 134 mPa .Math. s; V 10 Δn: 0.150; n.sub.e: 1.640; Δε: −4.5; V 0 3 ε.sub.⊥: 8.5; K.sub.11/K.sub.33: 14.2/14.8; the liquid crystal V 5 medium does not crystallize after being placed IV 3 in a temperature of −20° C. for 480 h. IV 9 IV 6 IV 3 IV 5 IV 15 IV 13 I 6 I 0 10

(106) TABLE-US-00004 TABLE 4 Component proportion and performance parameter of the liquid crystal medium in embodiment 9 Compound general Weight Performance formula Liquid crystal structural formula percentage (%) parameter V 17 S-N: ≤−40° C.; c.p: 100° C.; γ.sub.1: 140 mPa .Math. s; V 12 Δn: 0.105; n.sub.e: 1.594; Δε: −3.6; V 4 ε.sub.⊥: 7.4; K.sub.11/K.sub.33: 15.5/18.0; the liquid crystal V 3 medium does not crystallize after being placed V 5 in a temperature of −20° C. for 480 h. IV 5 IV 4 IV 4 IV 8 IV 00 8 IV 01 5 IV 02 12 IV 03 12 I 04 1

(107) TABLE-US-00005 TABLE 5 Component proportion and performance parameter of the liquid crystal medium in embodiment 10 Compound general Weight Performance formula Liquid crystal structural formula percentage (%) parameter V 05 14 S-N: ≤−40° C.; c.p: 78° C.; γ.sub.1: 89 Pa .Math. s; V 06 7 Δn: 0.106; n.sub.e: 1.595; Δε: −3.6; V 07 3 ε.sub.⊥: 7.4; K.sub.11/K.sub.33: 13.2/13.5; the liquid crystal V 08 8 medium does not crystallize after being placed V 09 7 in a temperature of −20° C. for 480 h. V 0 7 IV 5 IV 5 IV 9 IV 5 IV 10 IV 10 IV 5 I 5

(108) TABLE-US-00006 TABLE 6 Component proportion and performance parameter of the liquid crystal medium in embodiment 11 Compound general Weight Performance formula Liquid crystal structural formula percentage (%) parameter V 14 S-N: ≤−40° C.; c.p: 77° C.; γ.sub.1: 88 Pa .Math. s; V 0 7 Δn: 0.104; n.sub.e: 1.587; Δε: −3.7; V 3 ε.sub.⊥: 7.6; K.sub.11/K.sub.33: 13.7/13.9; the liquid crystal V 8 medium does not crystallize after being placed V 7 in a temperature of −20° C. for 480 h. V 7 IV 5 IV 5 IV 9 IV 5 IV 10 IV 0 10 IV 5 I 5

(109) TABLE-US-00007 TABLE 7 Component proportion and performance parameter of the liquid crystal medium in embodiment 12 Compound general Weight Performance formula Liquid crystal structural formula percentage (%) parameter V 32 S-N: ≤−40° C.; c.p: 85° C.; γ.sub.1: 145 mPa .Math. s; IV 12 Δn: 0.100; n.sub.e: 1.582; Δε: −5.0; ε.sub.⊥: 9.3; K.sub.11/K.sub.33: 14.5/16.5; IV 12 the liquid crystal medium does not crystallize after being placed in a temperature IV 8 of −20° C. for 480 h. IV 8 IV 8 IV 8 I 0 5 I 7

(110) TABLE-US-00008 TABLE 8 Component proportion and performance parameter of the liquid crystal medium in embodiment 13 Compound general Weight Performance formula Liquid crystal structural formula percentage (%) parameter V 38 S-N: ≤−40° C.; c.p: 75° C.; γ.sub.1: 108 mPa .Math. s; V 3 Δn: 0.100; n.sub.e: 1.581; Δε: −5.0; IV 5 ε.sub.⊥: 9.3; K.sub.11/K.sub.33: 14.5/18.5; the liquid crystal medium does not crystallize IV 8 after being placed in a temperature of −20° C. for 480 h. IV 10 IV 10 IV 6 IV 6 I 0 9 I 5

Comparison Embodiment 1

(111) A component is as shown in the following table 9, wherein components thereof include a compound of which a structural formula is formula VI but do not include the compound of which the structural formula is formula I.

Comparison Embodiment 2

(112) A component is as shown in the following table 10, wherein the components thereof include a compound of which a structural formula is formula VII but do not include the compound of which the structural formula is formula I.

(113) TABLE-US-00009 TABLE 9 Component proportion and performance parameter of the liquid crystal medium in embodiment 1 Compound general Weight Performance formula Liquid crystal structural formula percentage (%) parameter V 14 S-N: ≤−20° C.; c.p: 70° C.; γ.sub.1: 84 Pa .Math. s; V 7 Δn: 0.100; n.sub.e: 1.586; Δε: −3.2; V 3 ε.sub.⊥: 6.8; K.sub.11/K.sub.33: 12.3/12.8; the liquid crystal V 8 medium crystallizes after being placed in a temperature V 7 of −20° C. for 240 h. V 7 IV 5 IV 5 IV 0 9 IV 5 IV 10 IV 10 IV 5 VI 5

(114) TABLE-US-00010 TABLE 10 Component proportion and performance parameter of the liquid crystal medium in embodiment 2 Compound general Weight Performance formula Liquid crystal structural formula percentage (%) parameter V 14 S-N: ≤−20° C.; c.p: 71° C.; γ.sub.1: 88 Pa .Math. s; V 7 Δn: 0.103; n.sub.e: 1.584; Δε: −3.3; V 3 ε.sub.⊥: 6.7; K.sub.11/K.sub.33: 12.0/12.5; the liquid crystal V 8 medium crystallizes after being placed in a temperature V 0 7 of −20° C. for 240 h. V 7 IV 5 IV 5 IV 9 IV 5 IV 10 IV 10 IV 5 VII 5

(115) It can be known from the performance parameters of the liquid crystal compositions shown in embodiments 6-13 that, the liquid crystal compositions of the present invention have excellent intersolubility and a negative dielectric constant of an extremely large absolute value. In addition, it can be known from the comparisons of embodiment 10 with comparison embodiment 1 and comparison embodiment 2 that, dibenzothiophene-class liquid crystal compounds using a cyclopropyl group, a cyclopentyl group, and a 2-tetrahydrofuryl group as end groups have better intersolubility than traditional dibenzothiophene-class liquid crystals using a flexible alkyl chain as an end group, and low temperature stability thereof is correspondingly improved. Therefore, the compound of formula I provided by the present invention can improve intersolubility of the liquid crystal compounds, thereby expanding an application range of a liquid crystal mixture; and the compound thus has an important application value.

(116) Although the present invention only lists out the specific compounds and proportion dosages thereof (weight percentage) of the above-described eight embodiments and the comparison embodiments thereof and the performance tests are performed, based on the above-described embodiments, the liquid crystal composition of the present invention can be further expanded and modified by using the liquid crystal compounds represented by formulas I, IV, and V involved in the present invention and preferred liquid crystal compounds of formulas I, IV, and V, and the objective of the present invention can be achieved by appropriately adjusting the proportion dosages thereof.

(117) Apparently, the above-described embodiments of the present invention are merely illustrative for clear description of the present invention and are not intended to limit the embodiments of the present invention, and those skilled in the art could also make other changes or modifications of different forms on the basis of the above description. The changes and modifications of all of the embodiments are not exhaustive herein, and any obvious changes or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.