LIQUID CRYSTAL COMPOUND, LIQUID CRYSTAL COMPOSITION THEREOF, AND LIQUID CRYSTAL DISPLAY DEVICE

Abstract

A liquid crystal compound represented by general formula F is useful as a liquid crystal composition and as a liquid crystal display device that contains the liquid crystal composition. The liquid crystal compound has a large clearing point, large optical anisotropy and sizable or large dielectric anisotropy absolute value under the condition of maintaining a suitable rotary viscosity, enabling the liquid crystal composition that contains the compound represented by general formula F has a large optical anisotropy, small rotational viscosity, high VHR (UV) and long low-temperature storage duration under the condition of maintaining proper clearing point, proper dielectric anisotropy absolute value and proper VHR (initial), and the liquid crystal display device that contains the liquid crystal composition of the present invention has good contrast, high response speed, high reliability and good low-temperature storage stability.

Claims

1.-12. (canceled)

13. A liquid crystal compound of general formula F: ##STR00125## wherein, R.sub.F1 represents H, halogen, C.sub.1-12 linear or branched alkyl, ##STR00126## wherein one or more nonadjacent CH.sub.2 in the C.sub.1-12 linear or branched alkyl can each be independently replaced by CC, O, CO, COO or OCO, and one or more H in the C.sub.1-12 linear or branched alkyl can each be independently substituted by F or Cl; ring ##STR00127## and ring ##STR00128## each independently represents ##STR00129## wherein one or more CH.sub.2 in ##STR00130## can be replaced by O, one or more single bond in the rings can be replaced by double bond, wherein one or more H on ##STR00131## can each be independently substituted by CN, F or Cl, and one or more CH in the rings can be replaced by N; X.sub.F represents O, S or CO; L.sub.F1 and L.sub.F2 each independently represents H, F, Cl, CF.sub.3 or OCF.sub.3; Z.sub.F1 and Z.sub.F2 each independently represents single bond, COO, OCO, CH.sub.2O, OCH.sub.2, CHCH, CC, CH.sub.2CH.sub.2, CF.sub.2CF.sub.2, (CH.sub.2).sub.4, CF.sub.2O or OCF.sub.2; n.sub.F1 and n.sub.F2 each independently represents 0, 1 or 2, wherein, when n.sub.F1 represents 2, ring ##STR00132## can be the same or different, wherein when n.sub.F2 represents 2, ring ##STR00133## can be the same or different, and Z.sub.F2 can be the same or different; and n.sub.F3 represents an integer of 0-4.

14. The liquid crystal compound according to claim 13, wherein the compound of general formula F is selected from a group consisting of the following compounds: ##STR00134## ##STR00135## ##STR00136## wherein, X.sub.F1 and X.sub.F2 each independently represents CH.sub.2 or O.

15. The liquid crystal compound according to claim 13, wherein both of n.sub.F1 and n.sub.F2 represent 0.

16. The liquid crystal compound according to claim 13, wherein the compound of general formula F-1 is selected from a group consisting of the following compounds: ##STR00137## ##STR00138## the compound of general formula F-2 is selected from a group consisting of the following compounds: ##STR00139## ##STR00140## the compound of general formula F-5 is selected from a group consisting of the following compounds: ##STR00141## the compound of general formula F-6 is selected from a group consisting of the following compounds: ##STR00142## the compound of general formula F-9 is selected from a group consisting of the following compounds: ##STR00143##

17. A liquid crystal composition comprising at least one liquid crystal compound of general formula F according to claim 13.

18. The liquid crystal composition according to claim 17, wherein the liquid crystal composition comprises at least one compound of general formula N: ##STR00144## wherein, R.sub.N1 and R.sub.N2 each independently represents C.sub.1-12 linear or branched alkyl, ##STR00145## wherein one or more nonadjacent CH.sub.2 in the C.sub.1-12 linear or branched alkyl can each be independently replaced by CHCH, CC, O, CO, COO or OCO; ring ##STR00146## and ring ##STR00147## each independently represents or ##STR00148## wherein one or more CH.sub.2 in ##STR00149## can be replaced by O, one or more single bond in the rings can be replaced by double bond, wherein one or more H on ##STR00150## can each be independently substituted by F, Cl or CN, and one or more CH in the rings can be replaced by N; Z.sub.N1 and Z.sub.N2 each independently represents single bond, COO, OCO, CH.sub.2O, OCH.sub.2, CHCH, CC, CH.sub.2CH.sub.2, CF.sub.2CF.sub.2, (CH.sub.2).sub.4, CF.sub.2O or OCF.sub.2; L.sub.N1 and L.sub.N2 each independently represents H, C.sub.1-3 alkyl, or halogen; n.sub.N1 represents 0, 1, 2 or 3, n.sub.N2 represents 0 or 1, and 0n.sub.N1+n.sub.N23, when n.sub.N1=2 or 3, ring ##STR00151## can be the same or different, and Z.sub.N1 can be the same or different.

19. The liquid crystal composition according to claim 18, wherein the compound of general formula N is selected from a group consisting of the following compounds: ##STR00152## ##STR00153## ##STR00154## ##STR00155##

20. The liquid crystal composition according to claim 18, wherein the liquid crystal composition further comprises at least one compound of general formula M: ##STR00156## wherein, R.sub.M1 and R.sub.M2 each independently represents C.sub.1-12 linear or branched alkyl, ##STR00157## wherein one or more nonadjacent CH.sub.2 in the C.sub.1-12 linear or branched alkyl can each be independently replaced by CHCH, CC, O, CO, COO or OCO; ring ##STR00158## ring ##STR00159## and ring ##STR00160## each independently represents ##STR00161## wherein one or more CH.sub.2 in ##STR00162## can be replaced by O, one or more single bond in the rings can be replaced by double bond, wherein at most one H on ##STR00163## can be substituted by halogen; Z.sub.M1 and Z.sub.M2 each independently represents single bond, COO, OCO, CH.sub.2O, OCH.sub.2, CC, CHCH, CH.sub.2CH.sub.2 or (CH.sub.2).sub.4; and n.sub.M represents 0, 1 or 2, wherein when n.sub.M=2, ring ##STR00164## can be the same or different, and Z.sub.M2 can be the same or different.

21. The liquid crystal composition according to claim 20, wherein the compound of general formula M is selected from a group consisting of the following compounds: ##STR00165## ##STR00166## ##STR00167##

22. The liquid crystal composition according to claim 20, wherein the liquid crystal composition further comprises at least one polymerizable compound of general formula RM: ##STR00168## wherein, R.sub.1 represents H, halogen, CN, -Sp.sub.2-P.sub.2, C.sub.1-12 linear or branched alkyl, ##STR00169## wherein one or more nonadjacent CH.sub.2 in the C.sub.1-12 linear or branched alkyl, ##STR00170## can each be independently replaced by CHCH, CC, O, CO, COO or OCO, and one or more H can each be independently substituted by F or Cl; ring ##STR00171## and ring ##STR00172## each independently represents ##STR00173## wherein one or more CH.sub.2 in ##STR00174## can be replaced by O, and one or more single bond in the rings can be replaced by double bond, wherein one or more H on ##STR00175## can each be independently substituted by F, Cl, CN, -Sp.sub.3-P.sub.3, C.sub.1-12 halogenated or unhalogenated linear alkyl, C.sub.1-11 halogenated or unhalogenated linear alkoxy, ##STR00176## and one or more CH in the rings can be replaced by N; ring ##STR00177## represents ##STR00178## wherein one or more H on ##STR00179## can each be independently substituted by F, Cl, CN, -Sp.sub.3-P.sub.3, C.sub.1-12 halogenated or unhalogenated linear alkyl, C.sub.1-11 halogenated or unhalogenated linear alkoxy, ##STR00180## and one or more CH in the rings can be replaced by N; P.sub.1, P.sub.2 and P.sub.3 each independently represents a polymerizable group; Sp.sub.1, Sp.sub.2 and Sp.sub.3 each independently represents a spacer group or single bond; Z.sub.1 and Z.sub.2 each independently represents O, S, CO, COO, OCO, OCOO, CH.sub.2O, OCH.sub.2, CH.sub.2S, SCH.sub.2, CF.sub.2O, OCF.sub.2, CF.sub.2S, SCF.sub.2, (CH.sub.2).sub.d, CF.sub.2CH.sub.2, CH.sub.2CF.sub.2, (CF.sub.2).sub.d, CHCH, CFCF, CHCF, CFCH, CC, CHCHCOO, OCOCHCH, CH.sub.2CH.sub.2COO, OCOCH.sub.2CH.sub.2, CHR.sup.1, CR.sup.1R.sup.2 or single bond, wherein R.sup.1 and R.sup.2 each independently represents C.sub.1-12 linear or branched alkyl, and d represents an integer of 1-4; X.sub.0 represents O, S, CO CF.sub.2, NH or NF; a represents 0, 1 or 2, b represents 0 or 1, wherein when a represents 2, ring ##STR00181## can be the same or different, and Z.sub.1 can be the same or different.

23. The liquid crystal composition according to claim 22, wherein the compound of general formula RM is selected from a group consisting of the following compounds: ##STR00182## ##STR00183## ##STR00184## ##STR00185## X.sub.1-X.sub.10 and X.sub.12 each independently represents F, Cl, -Sp.sub.3-P.sub.3, C.sub.1-5 linear alkyl or alkoxy, ##STR00186##

24. The liquid crystal composition according to claim 22, wherein the compound of general formula F provides 0.1-30 wt. % of the total weight of the liquid crystal composition; the compound of general formula N provides 0.1-70 wt. % of the total weight of the liquid crystal composition; the compound of general formula M provides 0.1-70 wt. % of the total weight of the liquid crystal composition; the polymerizable compound of general formula RM provides 0.001-5 wt. % of the total weight of the liquid crystal composition.

25. The liquid crystal composition according to claim 17, wherein the liquid crystal composition further comprises at least one additive, the structure of the additive is ##STR00187## wherein, n represents a positive integer of 1-12.

26. A liquid crystal display device comprising the liquid crystal composition according to claim 17.

Description

DRAWINGS

[0138] FIG. 1 is a mass spectrogram of compound F-2-4.

[0139] FIG. 2 is a DSC cooling thermogram of compound F-2-4.

[0140] FIG. 3 is a DSC heating thermogram of compound F-2-4.

[0141] FIG. 4 is a mass spectrogram of compound F-1-4.

[0142] FIG. 5 is a DSC cooling thermogram of compound F-1-4.

[0143] FIG. 6 is a DSC heating thermogram of compound F-1-4.

DETAILED EMBODIMENTS

[0144] The present invention will be illustrated by combining the detailed embodiments below. It should be noted that, the following Examples are instances of the present invention, which are only used to illustrate the present invention, not to limit it. Other combinations and various modifications within the conception of the present invention are possible without departing from the subject matter and scope of the present invention.

[0145] In the present invention, if not specified otherwise, content refers to weight percent.

[0146] For the convenience of the expression, the group structures of the compounds in the following Examples are represented by the codes listed in Table 2:

TABLE-US-00002 TABLE 2 Codes of the group structures of the compounds Unit structure of group Code Name of group [00095] C 1,4-cyclohexylidene [00096] P 1,4-phenylene [00097] L 1,4-cyclohexene [00098] C(5) cyclopentyl [00099] G 2-fluoro-1,4-phenylene [00100] G' 3-fluoro-1,4-phenylene [00101] W 2,3-difluoro-1,4-phenylene [00102] B(O) 4,6-difluoro-dibenzo[b,d]furan-3,7-diyl [00103] B(S) 4,6-difluoro-dibenzo[b,d]thiophene-3,7-diyl [00104] V(2F) difluoroalkenyl F F fluorine substituent O O oxygen bridge bond CHCH or CHCH.sub.2 V ethenylene or ethenyl CH.sub.2O IO methyleneoxy CH.sub.2CH.sub.2 2 ethyl bridge bond C.sub.nH.sub.2n+1 or C.sub.nH.sub.2n n (n represents an alkyl or alkylene integer of 1-12)

[0147] Take the compound with following structural formula as an example:

##STR00105##

[0148] represented by the codes listed in Table 2, this structural formula can be expressed as nCCGF, in which, n in the code represents the number of the carbon atoms of the alkyl on the left, for example, n is 3, meaning that the alkyl is C.sub.3H.sub.7; C in the code represents 1,4-cyclohexylidene, G represents 2-fluoro-1,4-phenylene, and F represents fluorine substituent.

[0149] The abbreviated codes of the test items in the following Examples are as follows: [0150] Cp clearing point (nematic-isotropy phases transition temperature, C.) [0151] n optical anisotropy (589 nm, 20 C.) [0152] dielectric anisotropy (1 KHz, 20 C.) [0153] VHR(initial) initial voltage holding ratio (%) [0154] VHR(UV) voltage holding ratio after ultraviolet light (UV) irradiation (%) [0155] t.sub.30 C. low-temperature storage time (day, at 30 C.) [0156] .sub.1 rotational viscosity (mPa.Math.s, at 20 C.) [0157] wherein,

[0158] Cp: tested by melting point apparatus.

[0159] n: tested using an Abbe Refractometer under a sodium lamp (589 nm) light source at 20 C.

[0160] : =.sub.|.sub., in which, .sub.| is the dielectric constant parallel to the molecular axis, .sub. is the dielectric constant perpendicular to the molecular axis, test conditions: 20 C., 1 KHz, VA-type test cell with a cell gap of 6 m.

[0161] VHR (initial): initial voltage holding ratio, tested using a TOY06254 liquid crystal physical property evaluation system; the test temperature is 60 C., the test voltage is 5 V, the test frequency is 6 Hz, TN-type test cell with a cell gap of 9 m.

[0162] VHR (UV): tested using a TOY06254 liquid crystal physical property evaluation system; tested after using UV light with a wavelength of 365 nm and energy of 6000 mJ/cm.sup.2 to irradiate the liquid crystal, the test temperature is 60 C., the test voltage is 5 V, the test frequency is 6 Hz, TN-type test cell with a cell gap of 9 m.

[0163] t.sub.30 C.: the time recorded when precipitation of crystals is observed after the nematic liquid crystal medium being placed in a glass bottle and stored at 30 C.

[0164] .sub.1: tested using a LCM-2 type liquid crystal physical property evaluation system; test conditions: 20 C., 160-260 V, the cell gap is 20 m.

[0165] The liquid crystal compound of the general formula F of the present invention can be prepared by conventional organic synthesis methods, wherein the methods of introducing target terminal groups, ring structures and linking groups into the starting material are documented in the following literatures: Organic Synthesis, John Wiley & Sons Inc., Organic Reactions, John Wiley & Sons Inc., Comprehensive Organic Synthesis, Pergamon Press and so forth.

[0166] The method of synthesizing the linking groups Z.sub.F1 to Z.sub.F3 in the liquid crystal compound of general formula F can refer to the following process, wherein MSG.sup.1 or MSG.sup.2 is a monovalent organic group having at least one ring, and a plurality of MSG.sup.1 (or MSG.sup.2) used in the following process can be the same or different.

(1) Synthesis of Single Bond

##STR00106##

[0167] Aryl boronic acid 1 is reacted, in an aqueous solution of sodium carbonate in the presence of a catalyst, such as tetrakis(triphenylphosphine)palladium (Pd(PPh.sub.3).sub.4), with Compound 2 synthesized by a well-known method, to obtain a single-bonded Compound IA. Single-bonded Compound IA can also be prepared by reacting Compound 3 synthesized by a well-known method with n-butyllithium (n-BuLi), and then with zinc chloride and after that with Compound 2 in the presence of a catalyst, such as dichlorobis(triphenylphosphine)palladium (PdCl.sub.2(PPh.sub.3).sub.2) to prepare the single bonded Compound IA.

(2) Synthesis of COO and OCO

##STR00107##

[0168] Compound 3 is reacted with n-butyllithium and then with carbon dioxide to obtain carboxylic acid 4. Compound IB with COO is synthesized by dehydrating Compound 4 in the presence of 1,3-dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP) with Compound 5 synthesized by a well-known method. Compounds having OCO can also be synthesized by this method.

(3) Synthesis of CF.sub.2O and OCF.sub.2

##STR00108##

[0169] Referring to M. Kuroboshi et al., Chem. Lett., 1992,827, Compound 6 is obtained by treating Compound IB with a sulfiding agent, such as Lawesson's reagent, and then Compound IC with CF.sub.2O is synthesized by fluorination of Compound 6 by hydrofluoro-pyridine (HF-Py) and N-bromosuccinimide (NBS). Compound IC with CF.sub.2O can also be prepared by fluorination of Compound 6 with (diethylamino)sulfur trifluoride (DAST) with reference to W. H. Bunnelle et al., J. Org. Chem, 1990, 55, 768. Compounds having OCF.sub.2 can also be synthesized by these methods.

(4) Synthesis of CHCH

##STR00109##

[0170] Compound 3 is reacted with n-butyllithium and then with formamide, such as N,N-dimethylformamide (DMF) to obtain Compound 7. Phosphonium generated via reacting potassium tert-butoxide (t-BuOK) with a phosphonium salt 8 synthesized by a well-known method is reacted with Compound 7 to obtain Compound ID. The above method generates a cis-isomer due to the reaction conditions. It would be understood that the cis-isomer can be converted to a trans-isomer by the well-known method as needed.

(5) Synthesis of CH.sub.2CH.sub.2

##STR00110##

[0171] Compound IE can be prepared by conducting hydrogenation of Compound ID by using catalyst, such as, palladium on carbon (Pd/C).

(6) Synthesis of CH.sub.2O or OCH.sub.2

##STR00111##

[0172] Compound 7 is reduced using sodium borohydride (NaBH.sub.4) to obtain Compound 9. Compound 10 is then obtained by halogenating Compound 9 with hydrobromic acid, or, Compound 11 is obtained by protecting the hydroxyl group of Compound 9 with p-toluenesulfonic acid (TsOH). Compound 10 or Compound 11 is then reacted with Compound 5 in the presence of potassium carbonate to obtain Compound IF. Compounds with OCH.sub.2 can also be synthesized by these methods.

(7) Synthesis of CHCF.SUB.2

##STR00112##

[0173] Compound IG can be prepared by removing the hydrofluoric acid from the end group chain of compound 11 using a tetrahydrofuran solution of lithium diisopropylamide (LDA).

[0174] With respect to ring structures such as 1,4-cyclohexylidene, 1,3-dioxan-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, 2,3,5,6-tetrafluoro-1,4-phenylene and the like, commercially available starting materials already exist, or synthetic methods thereof are known in the art.

[0175] Followings clarify preferred synthetic methods of representative compounds.

Synthetic Example 1

[0176] Synthetic route of compound F-2-4 is shown as below:

##STR00113##

Step 1. Preparation of Compound of Formula B-3

[0177] 99 g of compound of formula B-1 ((4-butoxy-2,3-difluorophenyl)boronic acid), 100 g of compound of formula B-2 (2-bromo-6-fluorophenol), and 110 g of sodium carbonate are added into a 2 L reaction flask, and fully dissolved with 1.2 L of a mixed solvent consisting of toluene, ethanol, and water (the volume ratio of toluene, ethanol, and water is 2:1:1). Under the condition of being protected with nitrogen atmosphere, 1.8 g Pd(PPh.sub.3).sub.4 is added therein and a reflux reaction is conducted at 100 C. for 6 h. The reaction solution is cooled to room temperature, 300 mL water is added for liquid separation, and the aqueous phase is extracted with 20 mL of toluene, and the organic phases are combined, washed with saturated NaCl aqueous solution to pH=7, dried over anhydrous Na.sub.2SO.sub.4, concentrated, and recrystallized with a mixed solvent consisting of petroleum ether and toluene (the volume ratio of petroleum ether and toluene is 24:1) to obtain 109.5 g of compound of formula B-3 (4-butoxy-2,3,3-trifluoro-[1,1-biphenyl]-2-ol) as a white solid (yield: 85%).

Step 2. Preparation of Compound of Formula B-4

[0178] 110 g of compound of formula B-3 and 72 g of potassium carbonate are added into a 2 L reaction flask and fully dissolved with 700 mL of N,N-dimethylformamide, and reacted at 120 C. for 9 h. The reaction mixture is cooled to room temperature, added with 3.5 L of water, stirred, and filtered to obtain the crude product. After ethanol pulping, filtering, and drying over anhydrous Na.sub.2SO.sub.4, 88.5 g of compound of formula B-4 (3-butoxy-4,6-difluorodibenzo[b,d]furan) as a gray solid is obtained (yield: 86.3%).

Step 3. Preparation of Compound of Formula B-5

[0179] 38 g of diisopropylamine is added into a 2 L reaction flask, fully dissolved with 500 mL of tetrahydrofuran, 150 mL of n-butyllithium is added under the condition of being protected with nitrogen atmosphere at a controlled temperature of 20 C., and reaction is carried out at a controlled temperature of 20 C. for 3 h. 90 g of compound of formula B-4 is added therein and reacted at a controlled temperature of 78 C. for 3 h. 70 g of triisopropyl borate is added, and reacted at a controlled temperature of 78 C. for 3 h. The pH is adjusted with dilute hydrochloric acid to 2-3, and the liquid is separated. The aqueous phase is extracted with ethyl acetate, the organic phases are combined, washed with saturated NaCl aqueous solution to pH=7, dried over anhydrous Na.sub.2SO.sub.4, concentrated, slurried with dichloromethane, and suction filtered. The filter cake is dried to obtain 73 g of compound of formula B-5 ((4,6-difluoro-7-butoxydibenzo[b,d]furan-3-yl)boronic acid) as a white solid (yield: 70%).

Step 4. Preparation of Compound of Formula B-6

[0180] 70 g of compound of formula B-5 is added into a 2 L reaction flask, fully dissolved with 700 mL of tetrahydrofuran, 68 g of 30% hydrogen peroxide is added at a controlled temperature of 10 C., and the reaction is carried out at 10 C. for 9 h. The reaction is quenched with 500 mL of 5% sodium thiosulfate solution, the liquid is separated, the aqueous phase is extracted with ethyl acetate, and the organic phases are combined, washed with saturated NaCl aqueous solution to pH=7, dried over anhydrous Na.sub.2SO.sub.4, concentrated, slurried with 25 mL of dichloromethane, and suction filtered. The filter cake is dried to obtain 55.6 g of compound of formula B-6 (4,6-difluoro-7-butoxydibenzo[b,d]furan-3-ol) as a white solid (yield: 90%).

Step 5. Preparation of Compound of Formula B-7

[0181] 70 g of compound of formula B-6 is added into a 2 L reaction flask, fully dissolved with 700 mL of tetrahydrofuran, and 68 g of trifluoroethanol is added at a controlled temperature of 10 C., and the reaction is carried out at a controlled temperature of 10 C. for 9 h. The aqueous phase is extracted with ethyl acetate, and the organic phases are combined, washed with saturated NaCl aqueous solution to pH=7, dried over anhydrous Na.sub.2SO.sub.4, concentrated, slurried with 25 mL of dichloromethane, and suction filtered. The filter cake is dried to obtain 53.8 g of compound of formula B-7 (4,6-difluoro-3-butoxy-7-(2,2,2-trifluoroethoxy)dibenzo[b,d]furan) as a white solid (yield: 60%).

Step 6. Preparation of Compound of Formula F-2-4

[0182] 40 g of compound of formula B-7 is added in a 2 L reaction flask, fully dissolved with 700 mL of tetrahydrofuran, and 40 g of 30% sodium hydroxide solution is added at a controlled temperature of 10 C. The reaction is carried out for 8 h. The reaction is quenched with 500 mL of 5% sodium thiosulfate, and the liquid is separated. The aqueous phase is extracted with ethyl acetate, and the organic phases are combined, washed with saturated NaCl aqueous solution to pH=7, dried over anhydrous Na.sub.2SO.sub.4, concentrated, slurried with 25 mL of dichloromethane, and filtered. Dried over, concentrated, slurried with 25 mL of dichloromethane, and suction filtered. The filter cake is dried to obtain 28.4 g of compound of formula F-2-4 (3-((2,2-difluorovinyl)oxy)-4,6-difluoro-7-butoxydibenzo[b,d]furan) as a white solid (yield: 75%).

[0183] The mass spectrogram of compound F-2-4 is shown in FIG. 1.

[0184] The DSC cooling thermogram of compound F-2-4 is shown in FIG. 2.

[0185] The DSC heating thermogram of compound F-2-4 is shown in FIG. 3.

Synthetic Example 2

[0186] Synthetic route of compound F-1-4 is shown as below:

##STR00114##

[0187] The synthetic method of the compound of formula B-3 is the same as that in Synthetic Example 1.

Step 1. Preparation of Compound of Formula B-8

[0188] 120 g of compound of formula B-3, 120 g of dimethylamino thioformyl chloride and 90 g of triethylamine are added in a 1 L reaction flask, fully dissolved with 440 mL of isododecane, and the reflux reaction is carried out under the condition of being protected with nitrogen atmosphere at a controlled temperature of 165 C. for 18 h. The reaction is cooled to 25 C., suction filtered, recrystallized with ethanol, and suction filtered. The filter cake is dried to obtain 78.9 g of compound of formula B-8 (3-butoxy-4,6-difluorodibenzo[b,d]thiophene) as a brown solid (yield: 66.667%).

Step 2. Preparation of Compound of Formula B-9

[0189] 38 g of diisopropylamine is added into a 2 L reaction flask, fully dissolve with 500 mL of tetrahydrofuran, 150 mL n-butyllithium is added under the condition of being protected with nitrogen atmosphere at a controlled temperature of 20 C., and the reaction is carried out at a controlled temperature of 20 C. for 3 h. 80 g of compound of formula B-8 is added, and the reaction is carried out at a controlled temperature of 78 C. for 3 h. 70 g of triisopropyl borate is added, and the reaction is carried out at a controlled temperature of 78 C. for 3 h. The pH is adjusted with dilute hydrochloric acid to 23, the liquid is separated. The aqueous phase is extracted with ethyl acetate, the organic phases are combined, washed with saturated NaCl aqueous solution to pH=7, dried over anhydrous Na.sub.2SO.sub.4, concentrated, slurried with dichloromethane, and suction filtered. The filter cake is dried to obtain 69 g of compound of formula B-9 (((4,6-difluoro-7-butoxydibenzo[b,d]thiophen-3-yl)boronic acid) as a white solid (yield: 75%).

Step 3. Preparation of Compound of Formula B-10

[0190] 70 g of compound of formula B-9 is added in a 2 L reaction flask, fully dissolved with 700 mL of tetrahydrofuran, 80 g of 30% hydrogen peroxide is added at a controlled temperature of 10 C., the reaction is carried out at a controlled temperature of 10 C. for 9 h. The reaction is quenched with 500 mL of 5% sodium thiosulfate solution. The liquid is separated, and the aqueous phase is extracted with ethyl acetate. The organic phases are combined, washed with saturated NaCl aqueous solution to pH=7, dried over anhydrous Na.sub.2SO.sub.4, concentrated, slurried with 25 mL of dichloromethane, and suction filtered. The filter cake is dried to obtain 41.3 g of compound of formula B-10 (4,6-difluoro-7-butoxydibenzo[b,d]thiophene-3-ol) as a white solid (yield: 64.3%).

Step 4. Preparation of Compound of Formula B-11

[0191] 70 g of compound of formula B-10 is added into a 2 L reaction flask, fully dissolved with 700 mL of tetrahydrofuran, and 68 g of trifluoroethanol is added at a controlled temperature of 10 C. The reaction is carried out at a controlled temperature of 10 C. for 9 h. The aqueous phase is extracted with ethyl acetate. The organic phases are combined, washed with saturated NaCl aqueous solution to pH=7, dried over anhydrous Na.sub.2SO.sub.4, concentrated, slurried with 25 mL dichloromethane, and suction filtered. The filter cake is dried to 56.7 g of compound of formula B-11 (4,6-difluoro-3-butoxy-7-(2,2,2-trifluoroethoxy)dibenzo[b,d]furan) as a white solid (yield: 64%).

Step 5. Preparation of Compound of Formula F-1-4

[0192] 40 g of compound of formula B-11 is added into a 2 L reaction flask, fully dissolved with 700 mL of tetrahydrofuran, 40 g of 30% sodium hydroxide solution is added at controlled temperature of 10 C., the reaction is carried out at controlled temperature of 10 C. for 8 h. The reaction is quenched with 500 mL of 5% sodium thiosulfate, the liquid is separated, and the aqueous phase is extracted with ethyl acetate. The organic phases are combined, washed with saturated NaCl aqueous solution to pH=7, dried over anhydrous Na.sub.2SO.sub.4, concentrated, slurried with 25 mL of dichloromethane, and suction filtered. The filter cake is dried to give 30.4 g of compound of formula F-1-4 (3-((2,2-difluorovinyl)oxy)-4,6-difluoro-7-butoxydibenzo[b,d]furan) as a white solid (yield: 80%).

[0193] The mass spectrogram of compound F-1-4 is shown in FIG. 4.

[0194] The DSC cooling thermogram of compound F-1-4 is shown in FIG. 5.

[0195] The DSC heating thermogram of compound F-1-4 is shown in FIG. 6.

[0196] The compound of general formula F prepared in the above Examples and compounds DB-1

##STR00115##

and DB-2

##STR00116##

known in the prior art are mixed with a parent liquid crystal in the ratio of 10%:90% by weight, respectively, to form mixtures. The values of the performance parameters of the compounds to be tested are calculated using the extrapolation method, wherein the extrapolated values of Cp, n and =((measured value of the mixture)0.9(measured value of the parent liquid crystal))/0.1 and the extrapolated value of .sub.1=10.sup.10(IgA-0.9IgB) wherein A is .sub.1 of the mixture and B is .sub.1 of the parent liquid crystal. The derivations of the values of the performance parameters such as clear point Cp, optical anisotropy n, dielectric anisotropy , and rotational viscosity .sub.1 are carried out according to this method.

TABLE-US-00003 TABLE 3 Composition of the parent liquid crystal Code of Test results for the Code of Weight general performance component percent formula parameters 3CCV 21 M-1 Cp 0.0896 3CWO2 20 N-2 n 91.20 5CWO2 5 N-2 3.4 3CPWO2 6 N-21 .sub.1 120 3CPWO3 6 N-21 3CCWO2 6 N-9 5CCWO2 7 N-9 4CCWO2 11 N-9 3CCWO3 6 N-9 5CC3 4 M-1 VCCP1 8 M-11 Total 100

[0197] The extrapolation results of liquid crystal performance parameters of the above compounds are shown in Table 4 below:

TABLE-US-00004 TABLE 2 Code of general Compound formula Cp n .sub.1 1OB(O)O4 DB-1 26 0.1557 194 11 C(5)OB(O)O4 DB-2 50 0.1594 250 12 4OB(O)OV2F F-2-4 84 0.1603 190 10.5 2OB(S)OV2F F-1-2 76 0.1613 200 15.8 3L1OB(O)OV2F F-9-3 120 0.1654 301 12 4OB(S)OV2F F-1-4 82 0.1619 201 16.4

[0198] As can be seen from the comparison of the test results of the performance parameters of compounds DB-1, DB-2 and the compound of formula F of the present invention in Table 4, the compound of general formula F of the present invention has a larger clearing point, a larger optical anisotropy and a comparable or larger absolute value of the dielectric anisotropy while maintaining an appropriate rotational viscosity.

[0199] The components used in the following Examples can either be synthesized by methods known in the art or be obtained commercially. The synthetic techniques are conventional, and each of the obtained liquid crystal compounds is tested to meet the standards of electronic compound.

[0200] In the present invention, if not specified otherwise, content refers to weight percent.

[0201] The liquid crystal compositions are prepared in accordance with the ratios of each of the liquid crystal compositions specified in the following Examples. The preparation of the liquid crystal compositions is proceeded according to the conventional methods in the art, such as mixed and prepared according to the ratios via heating, ultrasonic processing, suspending processing and so forth.

Application Comparative Example 1

[0202] The liquid crystal composition of Application Comparative Example 1 is prepared according to each compound and weight percentage listed in Table 5 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00005 TABLE 5 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CCV 37 M-1 Cp 79 3CWO2 10 N-2 n 0.1062 3CCWO1 6 N-9 3.9 3CCWO2 10 N-9 .sub.1 101 4CCWO2 7 N-9 VHR(initial) 92 2CPWO2 3 N-21 VHR(UV) 79 3CPWO2 10 N-21 t.sub.30 C. <7 2PWP3 4 N-24 3PWO2 9 N-19 2OB(S)O5 4 Total 100

Application Example 1

[0203] The liquid crystal composition of Application Example 1 is prepared according to each compound and weight percentage listed in Table 6 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00006 TABLE 6 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CCV 37 M-1 Cp 80.5 3CWO2 10 N-2 n 0.109 3CCWO1 6 N-9 4 3CCWO2 10 N-9 .sub.1 95 4CCWO2 7 N-9 VHR(initial) 92.3 2CPWO2 3 N-21 VHR(UV) 88 3CPWO2 10 N-21 t.sub.30 C. >7 2PWP3 4 N-24 3PWO2 9 N-19 4OB(S)OV(2F) 4 F-1-4 Total 100

[0204] As can be seen from the comparison of the Application Comparative Example 1 and the Application Example 1, the liquid crystal composition of the present invention has a smaller rotational viscosity, a higher VHR(UV) and a longer low temperature storage time while maintaining an appropriate clearing point, an appropriate optical anisotropy, an appropriate absolute value of the dielectric anisotropy and an appropriate VHR(initial).

Application Comparative Example 2

[0205] The liquid crystal composition of Application Comparative Example 2 is prepared according to each compound and weight percentage listed in Table 7 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00007 TABLE 7 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CCV1 8 M-1 Cp 75 2CC3 13.5 M-1 n 0.1085 3CC4 6 M-1 3.4 3CCP1 12 M-11 .sub.1 102 3CCP3 7 M-11 VHR(initial) 93 3CCWO2 8.5 N-9 VHR(UV) 75 3CWO2 20.5 N-2 t.sub.30 C. <7 3PWO2 3.5 N-19 2PWP3 8 N-24 2OB(S)O5 4 2OB(S)O4 3 2OB(S)O6 3 1PP2V1 3 M-4 Total 100

Application Example 2

[0206] The liquid crystal composition of Application Example 2 is prepared according to each compound and weight percentage listed in Table 8 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00008 TABLE 8 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CCV1 8 M-1 Cp 78 2CC3 13.5 M-1 n 0.114 3CC4 6 M-1 3.6 3CCP1 12 M-11 .sub.1 97 3CCP3 7 M-11 VHR(initial) 92.8 3CCWO2 8.5 N-9 VHR(UV) 85 3CWO2 20.5 N-2 t.sub.30 C. >7 3PWO2 3.5 N-19 2PWP3 8 N-24 2OB(S)OV(2F) 4 F-1-2 3OB(S)OV(2F) 3 F-1-3 4OB(S)OV(2F) 3 F-1-4 1PP2V1 3 M-4 Total 100

[0207] As can be seen from the comparison of the Application Comparative Example 2 and the Application Example 2, the liquid crystal composition of the present invention has a larger optical anisotropy, a smaller rotational viscosity, a higher VHR(UV) and a longer low temperature storage time while maintaining an appropriate clearing point, an appropriate absolute value of dielectric anisotropy and an appropriate VHR(initial).

Application Comparative Example 3

[0208] The liquid crystal composition of Application Comparative Example 3 is prepared according to each compound and weight percentage listed in Table 9 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00009 TABLE 9 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CCV 38.5 M-1 Cp 79.5 3CCWO1 4 N-9 n 0.1034 3CCWO2 10 N-9 4.4 3CLWO2 7 N-12 .sub.1 102 3CLWO3 3 N-12 VHR(initial) 90.3 2CPWO2 4 N-21 VHR(UV) 79 3CPWO2 10 N-21 t.sub.30 C. <7 3CWO2 9.5 N-2 3PWO2 6 N-19 2OB(S)O5 4 2OB(O)O5 4 Total 100

Application Example 3

[0209] The liquid crystal composition of Application Example 3 is prepared according to each compound and weight percentage listed in Table 10 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00010 TABLE 10 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CCV 38.5 M-1 Cp 82.3 3CCWO1 4 N-9 n 0.106 3CCWO2 10 N-9 4.5 3CLWO2 7 N-12 .sub.1 93 3CLWO3 3 N-12 VHR(initial) 91.3 2CPWO2 4 N-21 VHR(UV) 84 3CPWO2 10 N-21 t.sub.30 C. >9 3CWO2 9.5 N-2 3PWO2 6 N-19 4OB(S)OV(2F) 4 F-1-4 2OB(O)OV(2F) 4 F-2-2 Total 100

[0210] As can be seen from the comparison of the Application Comparative Example 3 and the Application Example 3, the liquid crystal composition of the present invention has a smaller rotational viscosity, a higher VHR(UV) and a longer low temperature storage time while maintaining an appropriate clearing point, an appropriate optical anisotropy, an appropriate absolute value of the dielectric anisotropy and an appropriate VHR(initial).

Application Example 4

[0211] The liquid crystal composition is prepared according to each compound and weight

##STR00117##

percentage listed in Table 11, 0.3 wt. %is added into the liquid crystal composition shown in Table 11 as Application Example 4 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00011 TABLE 11 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 2CLWO2 9 N-12 Cp 80 3CLWO3 4 N-12 n 0.11 5CLWO2 9 N-12 3.8 3CCV 37 M-1 .sub.1 90 3CLWO2 26 N-12 VHR(initial) 92.9 3PGWO4 2 N-30 VHR(UV) 88 3PGWO2 2 N-30 t.sub.30 C. >7 5PGWO2 2 N-30 4PGWO2 1 N-30 1VCPWO2 3 N-21 4OB(S)OV(2F) 3 F-1-4 2OB(S)OV(2F) 2 F-1-2 Total 100

Application Example 5

[0212] Adding 0.3% polymerizable compound RM-1-1 into the liquid crystal composition of Example 1 can realize polymerization with a faster speed for forming an angle and a smaller pre-tilt angle is formed.

##STR00118##

Application Example 6

[0213] Adding 0.3% polymerizable compound RM-2-1 the liquid crystal composition of Example 2 can realize polymerization with a faster speed for forming an angle and a smaller pre-tilt angle is formed.

##STR00119##

Application Example 7

[0214] The liquid crystal composition of Application Example 7 is prepared according to each compound and weight percentage listed in Table 12 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00012 TABLE 12 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CCV 35.5 M-1 Cp 75 3CCV1 10 M-1 n 0.11 3CCP1 2 M-11 3.1 3CCWO1 2 N-9 .sub.1 80 3CLWO2 9.5 N-12 VHR(initial) 96.1 2CPWO2 10 N-21 VHR(UV) 92 3CPWO2 10.5 N-21 t.sub.30 C. >7 3PWO2 16.5 N-19 3PGWO2 1 N-30 20B(O)OV(2F) 3 F-2-2 Total 100

Application Example 8

[0215] The liquid crystal composition of Application Example 8 is prepared according to each compound and weight percentage listed in Table 13 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00013 TABLE 13 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CPP2 1 M-13 Cp 75.7 2CPWO2 11.5 N-21 n 0.114 3CLWO2 4 N-12 3 3CCP3 6.5 M-11 .sub.1 65 3CCP1 12.5 M-11 VHR(initial) 95.9 3PWO2 6 N-19 VHR(UV) 91 3CCV 25.5 M-1 t.sub.30 C. >7 3CCV1 9 M-1 1OG'WO2 5 N-27 2OPWO2 11 N-19 2OB(O)OV(2F) 3 F-2-2 2OB(S)OV(2F) 5 F-1-2 Total 100

Application Example 9

[0216] The liquid crystal composition is prepared according to each compound and weight percentage listed in Table 14, 0.3 wt. %

##STR00120##

is added into the liquid crystal composition shown in Table 14 as Application Example 9 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00014 TABLE 14 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CLWO2 9.2 N-12 Cp 75 3CLWO3 6.7 N-12 n 0.109 5CLWO2 9.2 N-12 4 3PWO2 12.5 N-19 .sub.1 85 3OGWO2 5 N-27 VHR(initial) 93.9 3CCV 35.4 M-1 VHR(UV) 90 3LWO2 9 N-3 t.sub.30 C. >7 1VCPWO2 5 N-21 4OB(S)OV(2F) 4 F-1-4 2OB(S)OV(2F) 4 F-1-2 Total 100

Application Example 10

[0217] The liquid crystal composition is prepared according to each compound and weight percentage listed in Table 15, 0.3 wt. %

##STR00121##

is added into the liquid crystal composition shown in Table 15 as Application Example 10 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00015 TABLE 15 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CLWO2 9.2 N-12 Cp 76 3CLWO3 6 N-12 n 0.106 5CLWO2 9.2 N-12 4 3PWO2 5 N-19 .sub.1 90 3OGWO2 4 N-27 VHR(initial) 93.9 3CCV 30.4 M-1 VHR(UV) 88 3LWO2 9 N-3 t.sub.30 C. >7 3CWO2 14.2 N-2 1VCPWO2 5 N-21 4OB(S)OV(2F) 4 F-1-4 2OB(S)OV(2F) 4 F-1-2 Total 100

Application Example 11

[0218] The liquid crystal composition is prepared according to each compound and weight percentage listed in Table 16, 0.3 wt. %

##STR00122##

is added into the liquid crystal composition shown in Table 16 as Application Example 11 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00016 TABLE 16 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CLWO2 9.2 N-12 Cp 85 3CLWO3 6.7 N-12 n 0.114 5CLWO2 9.2 N-12 4.2 3PWO2 12.5 N-19 .sub.1 99 3OGWO2 5 N-27 VHR(initial) 92.9 3CCV 35.4 M-1 VHR(UV) 88 3LWO2 9 N-3 t.sub.30 C. >7 1VCPWO2 5 N-21 4C1OB(S)OV(2F) 4 F-6-4 2L1OB(S)OV(2F) 4 F-5-2 Total 100

Application Example 12

[0219] The liquid crystal composition is prepared according to each compound and weight percentage listed in Table 17, 0.3 wt. %

##STR00123##

is added into the liquid crystal composition shown in Table 17 as Application Example 12 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00017 TABLE 17 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CLWO2 9.2 N-12 Cp 78.7 4CLWO2 9.2 N-12 n 0.111 3OGWO2 3.8 N-27 4.5 5CLWO2 9.2 N-12 .sub.1 98 2OPWO2 7 N-19 VHR(initial) 92.9 3PWO2 3 N-19 VHR(UV) 86 3CCV 34.7 M-1 t.sub.30 C. >7 3LWO2 18.5 N-3 2OB(O)OV(2F) 2 F-2-2 4OB(S)OV(2F) 2 F-1-4 2OB(S)OV(2F) 1.4 F-1-2 Total 100

Application Example 13

[0220] The liquid crystal composition is prepared according to each compound and weight percentage listed in Table 18, 0.3 wt. %

##STR00124##

is added into the liquid crystal composition shown in Table 18 as Application Example 13 and the performance test is carried out by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00018 TABLE 18 Formulation and test results for the performance parameters of the liquid crystal composition Code of Code of Weight general Test results for the component percent formula performance parameters 3CCWO2 9.2 N-9 Cp 73 4CCWO2 9.2 N-9 n 0.108 3OG'WO2 3.8 N-27 4.3 5CLWO2 9.2 N-12 .sub.1 105 2OPWO2 7 N-19 VHR(initial) 92.9 3PWO2 3 N-19 VHR(UV) 86 3CCV 34.7 M-1 t.sub.30 C. >7 3CWO2 18.5 N-2 2OB(O)OV(2F) 2 F-2-2 4OB(S)OV(2F) 2 F-1-4 2OB(S)OV(2F) 1.4 F-1-2 Total 100

[0221] In conclusion, the liquid crystal compound of general formula F provided by the present invention has a larger clearing point, a larger optical anisotropy, and a comparable or larger absolute value of dielectric anisotropy while maintaining an appropriate rotational viscosity; the liquid crystal composition of the present invention has a larger optical anisotropy, a smaller rotational viscosity, a higher VHR(UV), and a longer low temperature storage time while maintaining an appropriate clearing point, an appropriate absolute value of dielectric anisotropy and an appropriate VHR(initial), such that the liquid crystal display device comprising the same has a better contrast, a faster response speed, a higher reliability and a better low-temperature storage stability.

[0222] The above embodiments are merely illustrative of the technical concepts and features of the present invention, and provided for facilitating the understanding and practice of the present invention by those skilled in the art. However, the protection scope of the invention is not limited thereto. Equivalent variations or modifications made without departing from the spirit and essence of the present invention are intended to be contemplated within the protection scope of the present invention.

INDUSTRIAL APPLICABILITY

[0223] The liquid crystal compound, the liquid crystal composition thereof, and the liquid crystal display device involved in the present invention can be applied to the field of liquid crystal.