A dimorphic compound, its preparation method and application

Abstract

This invention relates to a dimetacrystalline compound, its preparation method, and its applications. The liquid crystal composition formed by the dimetacrystalline compound provided by this invention has suitable optical anisotropy, dielectric anisotropy, clearing point, and flow viscosity, and can be applied to liquid crystal display devices. Furthermore, the synthesis route of this dimetacrystalline compound is short, the yield is high, the post-processing is simple, and the cost is low, making it suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of liquid crystal materials technology, and in particular to a dicrystalline compound, its preparation method, and its applications. Background Technology

[0002] Liquid crystal displays (LCDs) have experienced rapid development due to their small size, light weight, low power consumption, and excellent display quality, especially in portable electronic information products. With the increasing size of LCD screens used in portable computers, office applications, and video applications, LCDs have been able to be used for large-screen displays and have ultimately replaced cathode ray tube (CRT) displays.

[0003] As a liquid crystal material, it needs to have good chemical and thermal stability as well as stability to electric fields and electromagnetic radiation. It should have a wide nematic phase temperature range, suitable birefringence anisotropy, very high resistivity, good UV resistance, high charge retention rate and low vapor pressure. It also needs to have appropriate dielectric anisotropy, optical anisotropy and flow viscosity.

[0004] Therefore, providing a liquid crystal compound with excellent performance and a simple preparation method has good application prospects. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a dicrystalline compound, its preparation method, and its applications. The liquid crystal composition prepared from the dicrystalline compound provided by this invention exhibits suitable optical anisotropy, dielectric anisotropy, clearing point, and flow viscosity. Furthermore, the synthesis route of this dicrystalline compound is short, the post-processing is simple, and the cost is low, making it suitable for industrial production.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a dimesocrystalline compound having a structure as shown in Formula F:

[0008]

[0009] Wherein, Z is selected from methylene, substituted or unsubstituted groups of the following: phenylene, biphenylene, terphenylene, cyclohexane, bicyclohexane or tercyclohexane; wherein each of the substituted substituents is independently selected from -F, -CF3, -OCH3 or -OCF3;

[0010] Optionally, one or at least two -CH2- can be independently replaced by -O-, -S-, or -COO-. In the middle -CH2-, one or at least two Hs can be independently replaced by -F or -CF3;

[0011] X1 and X2 are each independently selected from -F, -CF3, -OCH3 or -OCF3;

[0012] n1 and n2 are each independently selected from integers from 1 to 10 (for example, they can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10);

[0013] m1 and m2 are each independently selected from integers from 0 to 4 (for example, they can be 0, 1, 2, 3, 4).

[0014] The liquid crystal composition formed by the dicrystalline compound provided in this invention has suitable optical anisotropy, dielectric anisotropy, clearing point and flow viscosity.

[0015] Preferably, the dimorphic compound is selected from any one of the following structures:

[0016]

[0017]

[0018] Where Z represents methylene;

[0019] n1, n2, X1, X2 have the same defined range as the general formula F.

[0020] Preferably, the dimorphic compound is selected from any one of the following structures:

[0021]

[0022] In a second aspect, the present invention provides a method for preparing the dimorphic compound according to the first aspect, the method comprising the following steps:

[0023] (1) Compound A reacts with compound B to give compound C; the reaction formula is shown below:

[0024]

[0025] (2) Compound C reacts with compound D to give compound E; the reaction formula is shown below:

[0026]

[0027] (3) Compound E undergoes a hydrogenation-reduction reaction to give compound F; the reaction formula is shown below:

[0028]

[0029] Wherein, Z is selected from methylene, substituted or unsubstituted groups of the following: phenylene, biphenylene, terphenylene, cyclohexane, bicyclohexane or tercyclohexane; wherein each of the substituted substituents is independently selected from -F, -CF3, -OCH3 or -OCF3;

[0030] Optionally, one or at least two -CH2- can be independently replaced by -O-, -S-, or -COO-. In the middle -CH2-, one or at least two Hs can be independently replaced by -F or -CF3;

[0031] Y1 and Y2 are each independently selected from halogens, and the reactivity of Y1 is greater than that of Y2;

[0032] X1 and X2 are each independently selected from -F, -CF3, -OCH3 or -OCF3;

[0033] B(OR)2 is selected from borate group or borate ester group;

[0034] n1 and n2 are each independently selected from integers from 1 to 10 (for example, they can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10);

[0035] m1 and m2 are each independently selected from integers from 0 to 4 (for example, they can be 0, 1, 2, 3, 4).

[0036] The method for preparing dimorphic compounds provided by this invention has a short synthetic route, high yield, simple post-processing, and low cost, making it suitable for industrial production.

[0037] In this invention, the halogen can be F, Cl, Br, or I, etc.

[0038] In this invention, B(OR)2 can be wait.

[0039] Preferably, the molar ratio of compound A and compound B in step (1) is 1:(2-4) (for example, it can be 1:2, 1:2.1, 1:2.2, 1:2.5, 1:2.8, 1:3, 1:4, etc.).

[0040] Preferably, the reaction in step (1) is carried out in the presence of a base.

[0041] Preferably, the base is selected from any one or a combination of at least two of triethylamine, diethylamine, pyridine, potassium acetate, or potassium carbonate.

[0042] Preferably, the molar ratio of compound A to base in step (1) is 1:(1 to 4) (for example, it can be 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.5, 1:3, 1:4, etc.).

[0043] Preferably, the reaction in step (1) is carried out in the presence of a catalyst.

[0044] Preferably, the catalyst is selected from any one or a combination of at least two of bis(diphenylphosphine)palladium dichloride, cuprous iodide, tetra(triphenylphosphine)palladium, or [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride(II).

[0045] Preferably, the molar ratio of compound A to catalyst in step (1) is 1:(0.004~0.2) (for example, it can be 1:0.004, 1:0.005, 1:0.006, 1:0.007, 1:0.008, 1:0.009, 1:0.01, 1:0.015, 1:0.02, 1:0.04, 1:0.05, 1:0.1, 1:0.2, etc.).

[0046] Preferably, the reaction in step (1) is carried out in the presence of a solvent.

[0047] Preferably, the solvent is selected from any one or a combination of at least two of toluene, tetrahydrofuran, N,N-dimethylformamide or N,N-dimethylacetamide.

[0048] Preferably, the reaction temperature in step (1) is 20 to 100°C (e.g., 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, etc.), and more preferably 50 to 80°C.

[0049] Preferably, the reaction time in step (1) is 2 to 10 hours (e.g., 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, etc.), and more preferably 2 to 4 hours.

[0050] Preferably, the reaction in step (1) is carried out in a protective gas.

[0051] Preferably, the protective gas is selected from nitrogen.

[0052] Preferably, the molar ratio of compound C and compound D in step (2) is 1:(2-4) (for example, it can be 1:2, 1:2.1, 1:2.2, 1:2.5, 1:2.8, 1:3, 1:4, etc.).

[0053] Preferably, the reaction in step (2) is carried out in the presence of a base.

[0054] Preferably, the alkali is selected from any one or a combination of at least two of potassium carbonate, sodium carbonate, sodium bicarbonate, cesium carbonate, potassium acetate, or potassium phosphate.

[0055] Preferably, the molar ratio of compound C to base in step (2) is 1:(1 to 4) (for example, it can be 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.5, 1:3, 1:4, etc.).

[0056] Preferably, the reaction in step (2) is carried out in the presence of a catalyst.

[0057] Preferably, the catalyst is selected from any one or a combination of at least two of bis(triphenylphosphine)palladium dichloride, tetra(triphenylphosphine)palladium, dichloroditert-butyl-(4-dimethylaminophenyl)phosphine (II) or tri(dibenzylideneacetone)palladium.

[0058] Preferably, the molar ratio of compound C to catalyst in step (2) is 1:(0.0002~0.05) (for example, it can be 1:0.0002, 1:0.0005, 1:0.001, 1:0.0015, 1:0.01, 1:0.015, 1:0.02, 1:0.04, 1:0.05, etc.).

[0059] Preferably, the reaction in step (2) is carried out in the presence of a solvent.

[0060] Preferably, the solvent is selected from any one or a combination of at least two of tetrahydrofuran, toluene, ethanol, or 1,4-dioxane.

[0061] Preferably, the reaction temperature in step (2) is 20 to 100°C (e.g., 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, etc.), and more preferably 50 to 80°C.

[0062] Preferably, the reaction time in step (2) is 2 to 10 hours (e.g., 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, etc.), and preferably 2 to 4 hours.

[0063] Preferably, the reaction in step (2) is carried out in a protective gas.

[0064] Preferably, the protective gas is selected from nitrogen.

[0065] Preferably, the hydrogenation reduction reaction in step (3) is carried out in the presence of a catalyst.

[0066] Preferably, the catalyst is selected from any one or a combination of at least two of palladium on carbon, platinum on carbon, ruthenium on carbon, or Raney nickel.

[0067] Preferably, the mass ratio of compound E to catalyst in step (3) is 1:(0.0001~0.05) (for example, it can be 1:0.0001, 1:0.0002, 1:0.0005, 1:0.001, 1:0.0015, 1:0.01, 1:0.015, 1:0.02, 1:0.04, 1:0.05, etc.).

[0068] Preferably, the hydrogenation reduction reaction in step (3) is carried out in the presence of a solvent.

[0069] Preferably, the solvent is selected from any one or a combination of at least two of tetrahydrofuran, diethyl ether, methanol, or toluene.

[0070] Preferably, the temperature of the hydrogenation reduction reaction in step (3) is 20 to 50°C (for example, it can be 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, etc.), preferably 30 to 40°C.

[0071] Preferably, the hydrogenation reduction reaction in step (3) takes 6 to 15 hours (e.g., 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 15 hours, etc.), with 6 to 10 hours being more preferred.

[0072] Preferably, the preparation method includes the following steps:

[0073] (1) Compound A, compound B, base and catalyst are mixed and reacted in a protective gas at 20-100℃ for 2-10 h to obtain compound C; the molar ratio of compound A, compound B, base and catalyst is 1:(2-4):(1-4):(0.004-0.2);

[0074] (2) Compound C, compound D, base, catalyst and solvent are mixed and reacted in a protective gas at 20-100℃ for 2-10 h to obtain compound E; the molar ratio of compound C, compound D, base and catalyst is 1:(2-4):(1-4):(0.0002-0.05);

[0075] (3) Mix compound E, catalyst and solvent, and carry out hydrogenation reduction reaction in hydrogen at 20-50℃ for 6-15h to obtain compound F; the mass ratio of compound E to catalyst is 1:(0.0001-0.05).

[0076] Thirdly, the present invention provides a liquid crystal composition comprising the dicrystalline compound as described in the first aspect.

[0077] Fourthly, the present invention provides a liquid crystal display device comprising the liquid crystal composition as described in the third aspect.

[0078] Compared with the prior art, the present invention has at least the following beneficial effects:

[0079] (1) The liquid crystal composition formed by the dicrystalline compound provided by the present invention has appropriate optical anisotropy, dielectric anisotropy, clearing point and flow viscosity, and can be applied to liquid crystal display devices.

[0080] (2) The preparation method of the dimorphic compound provided by the present invention has a short synthesis route, high yield, simple post-processing, low cost, and is suitable for industrial production. Detailed Implementation

[0081] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0082] Example 1

[0083] This embodiment provides a method for preparing the dimesocrystalline compound C-1, and the reaction formula is as follows:

[0084]

[0085] The procedure was as follows: In a 250 mL three-necked flask, 10.0 g (67 mmol) of compound A-1 (undec-1,10-diyne), 42.0 g (148 mmol) of compound B-1 p-bromoiodobenzene, 2.6 g (13 mmol) of cuprous iodide, and 0.2 g (0.3 mmol) of bis(triphenylphosphine)palladium dichloride were dissolved in triethylamine. The reaction was carried out under nitrogen atmosphere at 80 °C for 5 h. The organic phases were extracted, combined, washed with water, dried, dissolved, and passed through a column. The solvent was evaporated to dryness to obtain 30 g of white solid. The solid was recrystallized from ethanol, frozen, filtered, and dried to obtain 26 g of compound C-11,11-bis(4-bromophenyl)undec-1,10-diyne (purity: 95.91%, yield: 84%).

[0086] The mass spectrometry data of compound C-1 are: 298 (8%), 456 (32%), 457 (8%), 458 (100%), 459 (19%), 460 (100%), 466 (30%), 469 (51%), 470 (20%).

[0087] Example 2

[0088] This embodiment provides a method for preparing the dimesocrystalline compound C-2, and the reaction formula is as follows:

[0089]

[0090] The procedure was as follows: In a 250 mL three-necked flask, 10.0 g (67 mmol) of compound A-1 (undec-1,10-diyne), 28.4 g (148 mmol) of compound B-2 p-chlorobromobenzene, 2.6 g (13 mmol) of cuprous iodide, and 0.2 g (0.3 mmol) of bis(triphenylphosphine)palladium dichloride were dissolved in triethylamine. The reaction was carried out under nitrogen atmosphere at 80 °C for 5 h. The organic phases were extracted, combined, washed with water, dried, dissolved, and passed through a column. The solvent was evaporated to dryness to obtain 22 g of white solid. The solid was recrystallized from ethanol, frozen, filtered, and dried to obtain 20 g of compound C-2 1,11-bis(4-chlorophenyl)undec-1,10-diyne (purity: 94.22%, yield: 80%).

[0091] The mass spectrometry data of compound C-2 are: 320 (10%), 325 (8%), 338 (30%), 339 (8%), 340 (95%), 341 (17%), 368 (100%), 382 (30%), 422 (48%), and 423 (11%).

[0092] Example 3

[0093] This embodiment provides a method for preparing the dimesocrystalline compound C-3, and the reaction formula is as follows:

[0094]

[0095] The procedure was as follows: In a 250 mL three-necked flask, 10.0 g (48 mmol) of compound A-3 1,4-bis(pentan-4-yn-1-yl)benzene, 36.7 g (105 mmol) of compound B-3 4-bromo-1-iodo-2-(trifluoromethyl)benzene, 1.8 g (10 mmol) of cuprous iodide, and 0.1 g (0.2 mmol) of bis(triphenylphosphine)palladium dichloride were dissolved in triethylamine. The reaction was carried out under nitrogen atmosphere at 80 °C for 5 h. The organic phases were extracted, combined, washed with water, dried, dissolved, and passed through a column. The solvent was evaporated to dryness to obtain 27 g of a white solid. The solid was recrystallized from ethanol, frozen, filtered, and dried to obtain 25 g of compound C-3 1,11-bis(4-bromo-2-(trifluoromethyl)phenyl)undec-1,10-diyne (purity: 95.25%, yield: 88%).

[0096] The mass spectrometry data of compound C-3 are: 572 (10%), 577 (7%), 590 (28%), 591 (8%), 592 (92%), 593 (16%), 594 (100%), 634 (30%), 674 (43%), and 675 (10%).

[0097] Example 4

[0098] This embodiment provides a method for preparing the dimesocrystalline compound E-1, and the reaction formula is as follows:

[0099]

[0100] The procedure is as follows: In a 500 mL three-necked flask, 20.0 g (44 mmol) of compound C-1 1,11-bis(4-bromophenyl)undec-1,10-diyne, 25.0 g (109 mmol) of compound D-1 4-bromo-1-iodo-2-(trifluoromethyl)benzene, 24.1 g (175 mmol) of potassium carbonate, and 0.6 g (0.8 mmol) of bis(triphenylphosphine)palladium dichloride were fully dissolved in tetrahydrofuran. The reaction was carried out under nitrogen atmosphere at 75 °C for 3 h. The organic phases were extracted, combined, washed with water, dried, dissolved and passed through a column, and the solvent was evaporated to obtain 20 g of white solid. Recrystallization from ethanol, freezing, filtration and drying yielded 19 g of compound E-1 4',4”-(undeca-1,10-diyne-1,11-diyne)bis([1,1'-biphenyl]-4-nitrile) white solid (purity: 99.55%, yield: 86%).

[0101] The mass spectrometry data of compound E-1 are: 419 (10%), 433 (8%), 434 (92%), 435 (16%), 502 (100%), 576 (31%), 601 (33%), 616 (48%), and 617 (10%).

[0102] Example 5

[0103] This embodiment provides a method for preparing the dimesocrystalline compound E-1, and the reaction formula is as follows:

[0104]

[0105] The procedure was as follows: In a 500 mL three-necked flask, 20.0 g (54 mmol) of compound C-2 1,11-bis(4-chlorophenyl)undec-1,10-diyne, 19.9 g (135 mmol) of compound D-2 p-cyanobenzic acid, 29.9 g (175 mmol) of potassium carbonate, and 0.8 g (1.1 mmol) of bis(triphenylphosphine)palladium dichloride were fully dissolved in tetrahydrofuran. The reaction was carried out under nitrogen atmosphere at 75 °C for 3 h. The organic phases were extracted, combined, washed with water, dried, dissolved, and passed through a column. The solvent was evaporated to dryness to obtain 27 g of a white solid. The solid was recrystallized from ethanol, frozen, filtered, and dried to obtain 25 g of compound E-1 4',4”-(undec-1,10-diyne-1,11-diyne)bis([1,1'-biphenyl]-4-nitrile) as a white solid (purity: 99.34%, yield: 92%).

[0106] The mass spectrometry data of compound E-1 are: 419 (10%), 433 (8%), 434 (92%), 435 (16%), 502 (100%), 576 (31%), 601 (33%), 616 (48%), and 617 (10%).

[0107] Example 6

[0108] This embodiment provides a method for preparing the dimesocrystalline compound E-2, and the reaction formula is as follows:

[0109]

[0110] The procedure is as follows: In a 500 mL three-necked flask, 20.0 g (34 mmol) of compound C-3 1,11-bis(4-bromo-2-(trifluoromethyl)phenyl)undec-1,10-diyne, 18.1 g (84 mmol) of compound D-3 (4-cyano-3-(trifluoromethyl)phenyl)boric acid, 18.6 g (135 mmol) of potassium carbonate, and 0.5 g (0.7 mmol) of bis(triphenylphosphine)palladium dichloride were fully dissolved in tetrahydrofuran. The reaction was carried out under nitrogen atmosphere at 75 °C for 3 h. The organic phases were extracted, combined, washed with water, dried, dissolved and passed through a column, and the solvent was evaporated to obtain 16 g of white solid. Recrystallization from ethanol, freezing, filtration and drying yielded 15 g of compound E-2 4',4”-(undec-1,10-diyne-1,11-diyne)bis(3,3'-bis(trifluoromethyl)-[1,1'-biphenyl]-4-nitrile) white solid (purity: 99.22%, yield: 89%).

[0111] The mass spectrometry data of compound E-2 are: 719 (10%), 733 (8%), 734 (92%), 735 (16%), 774 (100%), 776 (31%), 801 (33%), 816 (48%), and 817 (10%).

[0112] Example 7

[0113] This embodiment provides a method for preparing the dimesocrystalline compound F-1, and the reaction formula is as follows:

[0114]

[0115] The procedure was as follows: In a 250 mL three-necked flask, 10.0 g (20 mmol) of compound E-1 (4',4”-(undecane-1,10-diyne-1,11-diyne) bis([1,1'-biphenyl]-4-nitrile) and 0.3 g (3% w) of palladium on carbon were fully dissolved in tetrahydrofuran. The reaction was carried out under hydrogen atmosphere at 40 °C for 10 h. The organic phases were separated, extracted, and combined, washed with water, dried, dissolved, and passed through a column. The solvent was evaporated to dryness to obtain 10 g of white solid. The solid was recrystallized from ethanol, frozen, filtered, and dried to obtain 9.5 g of compound F-1 4',4”-(undecane-1,11-dialkyl) bis([1,1'-biphenyl]-4-nitrile) white solid (purity: 99.90%, yield: 93.5%).

[0116] The mass spectrometry data of compound F-1 are: 467 (8%), 502 (32%), 503 (8%), 504 (70%), 505 (19%), 510 (100%), 556 (30%), 596 (51%), and 604 (13%).

[0117] Example 8

[0118] This embodiment provides a method for preparing the dimesocrystalline compound F-2, and the reaction formula is as follows:

[0119]

[0120] The procedure was as follows: In a 250 mL three-necked flask, 10.0 g (13 mmol) of compound E-2 4',4”-(undecane-1,10-diyne-1,11-diyne)bis(3,3'-bis(trifluoromethyl)-[1,1'-biphenyl]-4-nitrile) and 0.3 g (3% w) of palladium on carbon were fully dissolved in tetrahydrofuran. The reaction was carried out under hydrogen atmosphere at 40 °C for 10 h. The organic phases were separated, extracted, and combined, washed with water, dried, dissolved and passed through a column, and the solvent was evaporated to obtain 10 g of white solid. The solid was recrystallized from ethanol, frozen, filtered and dried to obtain 9.3 g of compound F-2 4',4”-(undecane-1,11-dialkyl)bis([1,1'-biphenyl]-4-nitrile) white solid (purity: 99.90%, yield: 92.0%).

[0121] The mass spectrometry data of compound F-2 are: 699 (8%), 702 (32%), 722 (8%), 734 (100%), 775 (19%), 782 (100%), 786 (30%), 796 (51%), and 800 (13%).

[0122] Example 9

[0123] This embodiment provides a method for preparing the dimesocrystalline compound F-3, and the reaction formula is as follows:

[0124]

[0125] The procedure was as follows: In a 250 mL three-necked flask, 10.0 g (16 mmol) of compound E-2 4',4'-(undec-1,10-diyne-1,11-diyne) bis(3'-(trifluoromethyl)-[1,1'-biphenyl]-4-nitrile) and 0.3 g (3% w) palladium on carbon were fully dissolved in tetrahydrofuran. The reaction was carried out under hydrogen atmosphere at 40 °C for 10 h. The organic phases were separated, extracted, and combined, washed with water, dried, dissolved, and passed through a column. The solvent was evaporated to dryness to obtain 10 g of white solid. The solid was recrystallized from ethanol, frozen, filtered, and dried to obtain 9.4 g of compound F-3 4',4'-(undec-1,11-dialkyl) bis(3'-(trifluoromethyl)-[1,1'-biphenyl]-4-nitrile) white solid (purity: 99.90%, yield: 92.8%).

[0126] The mass spectrometry data for compound F-3 are: 599 (10%), 605 (8%), 612 (30%), 619 (8%), 630 (95%), 641 (17%), 646 (100%), 683 (30%), 698 (48%), and 721 (11%). For ease of representation, the functional groups of the compounds in the following application examples are represented by the codes listed below:

[0127]

[0128]

[0129] Take the following compound with the following structural formula as an example:

[0130]

[0131] The structural formula, represented by the codes listed in Table 1, can be expressed as: nCCGF, where n represents the number of C atoms in the left-end alkyl group. For example, n = "3", indicating that the alkyl group is -C3H7. C represents cyclohexyl, G represents 2-fluoro-1,4-phenylene, and F represents fluorine. The abbreviated codes and test methods for the test items in the application examples are as follows:

[0132] The abbreviated codes for the test items in the following examples are as follows:

[0133] Cp clearing point (nematic-isotropic phase transition temperature, °C)

[0134] Δn optical anisotropy (589nm, 25℃)

[0135] Δε dielectric anisotropy (1 kHz, 25 °C)

[0136] η flow viscosity

[0137] in,

[0138] (1) Cp: obtained by melting point tester.

[0139] (2) Optical anisotropy was measured using an Abbe refractometer under a sodium lamp (589nm) light source at 25°C.

[0140] (3) Δε=ε ‖ -ε ⊥ , where ε ‖ ε is the dielectric constant parallel to the molecular axis. ⊥ The dielectric constant is perpendicular to the molecular axis. Test conditions: 25℃, 1KHz, test box is TN90 type, box thickness is 7μm.

[0141] (4) η (flow viscosity): Measured by an E-type viscometer under test conditions of 25±0.5℃.

[0142] Liquid crystal compositions were prepared according to the formulations of the liquid crystal compositions in the following application examples. The liquid crystal compositions were prepared according to conventional methods in the art, such as mixing in a specified ratio by heating, ultrasound, suspension, etc.

[0143] Application Example 1

[0144] This application example provides a liquid crystal composition comprising the components in the mass percentages shown in the table below, and performs performance testing by filling it between two substrates of a liquid crystal display:

[0145]

[0146] Application Example 2

[0147] This application example provides a liquid crystal composition comprising the components in the mass percentages shown in the table below, and performs performance testing by filling it between two substrates of a liquid crystal display:

[0148]

[0149] Application Example 3

[0150] This application example provides a liquid crystal composition comprising the components in the mass percentages shown in the table below, and performs performance testing by filling it between two substrates of a liquid crystal display:

[0151]

[0152]

[0153] The results show that the liquid crystal composition prepared by the dicrystalline compound provided by the present invention has appropriate optical anisotropy, dielectric anisotropy, clearing point and flow viscosity.

[0154] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A bimesogenic compound, characterized in that, The dimecic compound has a structure as shown in Formula F: Wherein, Z is selected from methylene, substituted or unsubstituted groups of the following: phenylene, biphenylene, terphenylene, cyclohexane, bicyclohexane or tercyclohexane; wherein each of the substituted substituents is independently selected from -F, -CF3, -OCH3 or -OCF3; optionally one or at least two -CH2- are each independently replaced with -O-, -S-, or -COO-, optionally one or at least two H on -CH2- are each independently replaced with -F, -CF3; X1 and X2 are each independently selected from -F, -CF3, -OCH3 or -OCF3; n1 and n2 are each independently selected from integers from 1 to 10; m1 and m2 are each independently selected from integers from 0 to 4.

2. The compound according to claim 1, wherein The dimorphic compound is selected from any one of the following structures: Where Z represents methylene; n1, n2, X1, X2 have the same defined range as the general formula F.

3. The compound of claim 1, wherein The dimorphic compound is selected from any one of the following structures:

4. A method for preparing a compound according to any one of claims 1 to 3, characterized in that The preparation method includes the following steps: (1) Compound A reacts with compound B to give compound C; the reaction formula is shown below: (2) Compound C reacts with compound D to give compound E; the reaction formula is shown below: (3) Compound E undergoes a hydrogenation-reduction reaction to give compound F; the reaction formula is shown below: Wherein, Z is selected from methylene, substituted or unsubstituted groups of the following: phenylene, biphenylene, terphenylene, cyclohexane, bicyclohexane or tercyclohexane; wherein each of the substituted substituents is independently selected from -F, -CF3, -OCH3 or -OCF3; optionally one or at least two -CH2- are each independently replaced with -O-, -S-, or -COO-, optionally one or at least two H on -CH2- are each independently replaced with -F, -CF3; Y1 and Y2 are each independently selected from halogens, and the reactivity of Y1 is greater than that of Y2; X1 and X2 are each independently selected from -F, -CF3, -OCH3 or -OCF3; B(OR)2 is selected from borate group or borate ester group; n1 and n2 are each independently selected from integers from 1 to 10; m1 and m2 are each independently selected from integers from 0 to 4.

5. The preparation method according to claim 4, characterized in that, The molar ratio of compound A and compound B in step (1) is 1:(2-4); Preferably, the reaction in step (1) is carried out in the presence of a base; Preferably, the base is selected from any one or a combination of at least two of triethylamine, diethylamine, pyridine, potassium acetate, or potassium carbonate; Preferably, the molar ratio of compound A to base in step (1) is 1:(1-4); Preferably, the reaction in step (1) is carried out in the presence of a catalyst; Preferably, the catalyst is selected from any one or a combination of at least two of bis(diphenylphosphine)palladium dichloride, cuprous iodide, tetra(triphenylphosphine)palladium, or [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride(II); Preferably, the molar ratio of compound A to catalyst in step (1) is 1:(0.004~0.2); Preferably, the reaction in step (1) is carried out in the presence of a solvent; Preferably, the solvent is selected from any one or a combination of at least two of toluene, tetrahydrofuran, N,N-dimethylformamide or N,N-dimethylacetamide; Preferably, the temperature of the reaction in step (1) is 20–100°C, more preferably 50–80°C; Preferably, the reaction time in step (1) is 2 to 10 hours, more preferably 2 to 4 hours; Preferably, the reaction in step (1) is carried out in a protective gas; Preferably, the protective gas is selected from nitrogen.

6. The preparation method according to claim 4, characterized in that, The molar ratio of compound C and compound D in step (2) is 1:(2-4); Preferably, the reaction in step (2) is carried out in the presence of a base; Preferably, the alkali is selected from any one or a combination of at least two of potassium carbonate, sodium carbonate, sodium bicarbonate, cesium carbonate, potassium acetate, or potassium phosphate; Preferably, the molar ratio of compound C to base in step (2) is 1:(1-4); Preferably, the reaction in step (2) is carried out in the presence of a catalyst; Preferably, the catalyst is selected from any one or a combination of at least two of bis(triphenylphosphine)palladium dichloride, tetra(triphenylphosphine)palladium, dichloroditert-butyl-(4-dimethylaminophenyl)phosphine (II)palladium(II) or tri(dibenzylideneacetone)palladium; Preferably, the molar ratio of compound C to catalyst in step (2) is 1:(0.0002~0.05); Preferably, the reaction in step (2) is carried out in the presence of a solvent; Preferably, the solvent is selected from any one or a combination of at least two of tetrahydrofuran, toluene, ethanol, or 1,4-dioxane; Preferably, the temperature of the reaction in step (2) is 20–100°C, more preferably 50–80°C; Preferably, the reaction time in step (2) is 2 to 10 hours, more preferably 2 to 4 hours; Preferably, the reaction in step (2) is carried out in a protective gas; Preferably, the protective gas is selected from nitrogen.

7. The preparation method according to claim 4, characterized in that, The hydrogenation reduction reaction described in step (3) is carried out in the presence of a catalyst; Preferably, the catalyst is selected from any one or a combination of at least two of palladium on carbon, platinum on carbon, ruthenium on carbon, or Raney nickel; Preferably, the mass ratio of compound E to catalyst in step (3) is 1:(0.0001~0.05); Preferably, the hydrogenation reduction reaction in step (3) is carried out in the presence of a solvent; Preferably, the solvent is selected from any one or a combination of at least two of tetrahydrofuran, diethyl ether, methanol, or toluene; Preferably, the temperature of the hydrogenation reduction reaction in step (3) is 20–50°C, more preferably 30–40°C; Preferably, the hydrogenation reduction reaction in step (3) takes 6 to 15 hours, more preferably 6 to 10 hours.

8. The preparation method according to claim 4, characterized in that, The preparation method includes the following steps: (1) Compound A, compound B, base and catalyst are mixed and reacted in a protective gas at 20-100℃ for 2-10 h to obtain compound C; the molar ratio of compound A, compound B, base and catalyst is 1:(2-4):(1-4):(0.004-0.2); (2) Compound C, compound D, base, catalyst and solvent are mixed and reacted in a protective gas at 20-100℃ for 2-10 h to obtain compound E; the molar ratio of compound C, compound D, base and catalyst is 1:(2-4):(1-4):(0.0002-0.05); (3) Mix compound E, catalyst and solvent, and carry out hydrogenation reduction reaction in hydrogen at 20-50℃ for 6-15h to obtain compound F; the mass ratio of compound E to catalyst is 1:(0.0001-0.05).

9. A liquid crystal composition, characterized in that, The liquid crystal composition includes the dicrystalline compound as described in any one of claims 1 to 3.

10. A liquid crystal display device, characterized in that, The liquid crystal display device includes the liquid crystal composition as described in claim 9.

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