Axial chiral circularly polarized luminescent liquid crystal compounds, and preparation method and application thereof

Abstract

The application belongs to the field of chiral luminescent liquid crystals, and specifically discloses an axially chiral circularly polarized luminescent liquid crystal compound and a preparation method and application thereof. 1 selected from substituted or unsubstituted alkyl, 2 selected from hydrogen, substituted or unsubstituted alkyl. The application first introduces a flexible chiral group, an alkylene cyclohexane, into a liquid crystal system, so that the molecule has both chirality and liquid crystal properties, and is combined with an aggregation-induced emission group, cyanodiphenyl ethylene, to obtain a novel skeleton of chiral 1-(4-cyanodiphenyl styryl phenyl)-4-alkylene cyclohexane, so that the molecule still has luminescent properties in an aggregated state (crystalline state, liquid crystal state). The application provides a novel axially chiral luminescent liquid crystal compound having chirality, liquid crystal properties and luminescent properties, and the axially chiral luminescent liquid crystal compound has extremely high circularly polarized luminescent brightness and optical quantum efficiency, and realizes excellent circularly polarized luminescent properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of chiral luminescent liquid crystals, and in particular relates to an axially chiral circularly polarized luminescent liquid crystal compound and a preparation method and application thereof. Background Art

[0002] There are two main ways to achieve circularly polarized luminescence through liquid crystal systems: first, doping chiral agents and non-chiral luminescent dyes into commercial non-chiral nematic liquid crystals (such as 5CB, E7, etc.); second, directly synthesizing chiral luminescent liquid crystals.

[0003] Among them, although chiral doping systems have been studied more, they often face problems such as a wide variety of additives, poor molecular matching, and easy phase separation of luminescent dyes, which makes the system complex and difficult to adjust; chiral luminescent liquid crystals are less reported because they need to take into account the introduction of molecular chirality, liquid crystal properties and luminescent properties, which makes molecular design difficult.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide an axially chiral circularly polarized luminescent liquid crystal compound and its preparation method and application, aiming to solve the problem in the prior art of the lack of new chiral luminescent liquid crystal materials with excellent circularly polarized luminescence properties.

[0006] The technical solutions of the present invention are as follows:

[0007] In a first aspect, the present invention provides an axially chiral circularly polarized luminescent liquid crystal compound, wherein the axially chiral circularly polarized luminescent liquid crystal compound has the following chemical structural formula:

[0008] Among them, R 1 is selected from substituted or unsubstituted alkyl groups, R 2 One selected from hydrogen, substituted or unsubstituted alkyl.

[0009] In a second aspect, the present invention provides a method for preparing the axially chiral circularly polarized luminescent liquid crystal compound, comprising the steps of:

[0010] S1, reacting compound 1 with trifluoromethanesulfonic anhydride and a base in a halogenated hydrocarbon solvent to obtain compound 2;

[0011] S2, reacting the compound 2 with a phosphorus ylide in a first organic solvent to obtain a racemate of the compound 3;

[0012] S3, reacting the racemate of compound 3 with a p-formylphenyl boron reagent, a palladium salt, a phosphine ligand, a base in a second organic solvent to obtain a racemate of compound 4, and performing chiral column chromatography separation on the racemate of compound 4 to obtain a single-handed enantiomer, i.e. compound (S)-4 and compound (R)-4;

[0013] S4, respectively reacting the compound (S)-4 and compound (R)-4 with a phenylacetonitrile derivative and a base in a third organic solvent to obtain the axially chiral circularly polarized luminescent liquid crystal compound (S)-V and (R)-V respectively.

[0014] The above synthesis route is as follows:

[0015]

[0016] In step S1, optionally, the base is at least one of pyridine, triethylamine and triisopropylamine; and the halogenated hydrocarbon solvent is at least one of dichloromethane, dichloroethane and trichloromethane.

[0017] Optionally, the molar ratio of compound 1 to trifluoromethanesulfonic anhydride is 1:1.2, and the molar ratio of compound 1 to the base is 1:2.

[0018] Optionally, the reaction temperature of compound 1, trifluoromethanesulfonic anhydride and the base in the halogenated hydrocarbon solvent is 0-40℃, and the reaction time is 1-24h.

[0019] In step S2, optionally, the molar ratio of compound 2 to phosphorus ylide is 1.13:1.

[0020] Optionally, the first organic solvent is at least one of tetrahydrofuran, methyl tetrahydrofuran, diethyl ether and 1,4-dioxane.

[0021] Optionally, the reaction temperature of compound 2 and phosphorus ylide in the first organic solvent is -80-40℃, and the reaction time is 1-24h.

[0022] In step S3, optionally, the p-formylphenyl boron reagent is p-formylphenyl boronic acid or p-formylphenyl boronic ester.

[0023] Optionally, the palladium salt is at least one of palladium chloride, palladium acetate and palladium trifluoromethanesulfonate.

[0024] Optionally, the phosphine ligand is at least one of triphenylphosphine, 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl.

[0025] Optionally, the base is at least one of sodium carbonate, potassium carbonate, cesium carbonate or potassium tert-butoxide.

[0026] Optionally, the second organic solvent is at least one of acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and toluene.

[0027] Optionally, the reaction temperature of the racemate of compound 3 with the p-formylphenylborane reagent, the palladium salt, the phosphine ligand and the base in the second organic solvent is 80-120° C., and the reaction time is 6-48 h.

[0028] Optionally, the solvent system used for the chiral column chromatography separation of the racemate of compound 4 is a mixed solvent of n-hexane and isopropanol, and the volume ratio of n-hexane to isopropanol is 4:1 to 200:1.

[0029] Optionally, the chiral column is one of IB, ID, IF and IH columns.

[0030] In step S4, optionally, the base is at least one of sodium methoxide, sodium ethoxide and piperidine.

[0031] Optionally, the third organic solvent is at least one of methanol, ethanol and pyridine.

[0032] Optionally, the temperature for reacting the compound (S)-4 or compound (R)-4 with the benzyl cyanide derivative and the base in the third organic solvent is 40-120° C., and the reaction time is 6-48 h.

[0033] In a third aspect, the present invention provides an application of the axially chiral circularly polarized luminescent liquid crystal compound in optical data storage, optical quantum information science, chirality recognition and medical imaging.

[0034] The present invention has the following beneficial effects:

[0035] The present invention addresses the difficulties in the design of chiral luminescent liquid crystals. By introducing a flexible chiral group alkylene cyclohexane, the molecule has both chirality and liquid crystal properties, and combining it with the aggregation-induced emission (AIE) group cyanodiphenylethylene, a chiral 1-(4-cyanodiphenylethylene phenyl)-4-alkylene cyclohexane skeleton is obtained, which is also a new skeleton that has not been reported. This allows the compound to still have luminescence properties in the aggregated state (crystalline state, liquid crystal state). This is the first time that the axial chiral unit alkylene cyclohexane in the structural unit has been applied to a liquid crystal system. Therefore, the present invention has produced a new axial chiral luminescent liquid crystal compound molecule that has both chirality, liquid crystal properties and luminescence properties, and achieved the circularly polarized luminescence performance of the axial chiral liquid crystal compound, with extremely high circularly polarized luminescence brightness B CPL and quantum efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a circularly polarized luminescence (CPL) test chart of the axially chiral circularly polarized luminescent liquid crystal compound prepared in Example 1 of the present invention.

[0037] Figure 2 This is a differential scanning calorimetry (DSC) graph of the axially chiral circularly polarized luminescent liquid crystal compound prepared in Example 1 of the present invention.

[0038] Figure 3 This is a polarizing microscope (POM) test image of the axially chiral circularly polarized luminescent liquid crystal compound prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0039] The present invention provides an axially chiral circularly polarized luminescent liquid crystal compound, a preparation method, and applications thereof. To clarify the objectives, technical solutions, and effects of the present invention, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0040] Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0041] An embodiment of the present invention provides an axially chiral circularly polarized luminescent liquid crystal compound. The axially chiral circularly polarized luminescent liquid crystal compound has the following chemical structure:

[0042] Among them, R 1 is selected from substituted or unsubstituted alkyl groups, R 2 One selected from hydrogen, substituted or unsubstituted alkyl.

[0043] This invention introduces a flexible chiral group, alkylenecyclohexane, into a liquid crystal system for the first time, allowing the molecule to possess both chirality and liquid crystal properties. This is combined with the aggregation-induced luminescence group, cyanodiphenylethylene, to produce a novel chiral 1-(4-cyanodiphenylphenylphenyl)-4-alkylenecyclohexane skeleton, which retains luminescence properties in aggregated (crystalline, liquid crystal) states. The compound represented by the chemical formula (S)-V or (R)-V possesses a chiral liquid crystal phase and forms a chiral self-assembled structure upon cooling and crystallization, achieving high g lum Value of circularly polarized luminescence, solid phase luminescence asymmetry factor |g lum | Up to 2.1*10 -2The photoluminescence quantum efficiency of the compound (S)-V or (R)-V in solid phase is high, up to 98.4%. The circularly polarized luminescence brightness B of the compound (S)-V or (R)-V in solid phase is high, up to 320M CPL cm -1 -1 The novel axially chiral luminescent liquid crystal compound provided by the application has chiral, liquid crystal and luminescent properties, has extremely high circularly polarized luminescence brightness and photoluminescence quantum efficiency, and realizes excellent circularly polarized luminescence performance.

[0044] The application further provides a preparation method of the axially chiral circularly polarized luminescent liquid crystal compound, comprising the following steps:

[0045] S1, reacting compound 1, triflic anhydride and a base in a halogenated hydrocarbon solvent to obtain compound 2;

[0046] S2, reacting the compound 2 with a phosphorus ylide in a first organic solvent to obtain a racemate (rac)-3 of compound 3;

[0047] S3, reacting the racemate (rac)-3 of compound 3 with a p-formyl phenyl boron reagent, a palladium salt, a phosphine ligand and a base in a second organic solvent to obtain a racemate (rac)-4 of compound 4, and performing chiral column chromatography separation on the racemate (rac)-4 of compound 4 to obtain a single enantiomer, i.e. compound (S)-4 and compound (R)-4;

[0048] S4, respectively reacting the compound (S)-4 and the compound (R)-4 with a phenylacetonitrile derivative and a base in a third organic solvent to obtain the axially chiral circularly polarized luminescent liquid crystal compounds (S)-V and (R)-V respectively;

[0049] The corresponding synthesis route of the above preparation method is shown as follows:

[0050]

[0051] In some embodiments, the base is at least one of pyridine, triethylamine and triisopropylamine; and the halogenated hydrocarbon solvent is at least one of dichloromethane, dichloroethane and trichloromethane.

[0052] In some embodiments, the molar ratio of the compound 1 to triflic anhydride is 1:1.2, and the molar ratio of the compound 1 to the base is 1:2.

[0053] In some embodiments, the reaction temperature of the compound 1, triflic anhydride and the base in the halogenated hydrocarbon solvent is 0-40℃, and the reaction time is 1-24h.

[0054] ​In step S2, in some embodiments, the molar ratio of compound 2 to phosphorus ylide is 1.13:1.

[0055] In some embodiments, the first organic solvent is at least one of tetrahydrofuran, methyltetrahydrofuran, diethyl ether and 1,4-dioxane.

[0056] In some embodiments, the reaction temperature of the compound 2 and the phosphorus ylide in the first organic solvent is -80-40° C., and the reaction time is 1-24 h.

[0057] In step S3, in some embodiments, the p-formylphenylborane reagent is p-formylphenylboronic acid or p-formylphenylboronic ester.

[0058] In some embodiments, the palladium salt is at least one of palladium chloride, palladium acetate, and palladium trifluoromethanesulfonate.

[0059] In some embodiments, the phosphine ligand is at least one of triphenylphosphine, 4,5-bisdiphenylphosphino-9,9-dimethylxanthene, 2-biscyclohexylphosphino-2',6'-dimethoxybiphenyl, and 2-biscyclohexylphosphino-2',4',6'-triisopropylbiphenyl.

[0060] In some embodiments, the base is at least one of sodium carbonate, potassium carbonate, cesium carbonate, or potassium tert-butoxide.

[0061] In some embodiments, the second organic solvent is at least one of acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and toluene.

[0062] In some embodiments, the reaction temperature of the racemate of compound 3 with the p-formylphenylborane reagent, the palladium salt, the phosphine ligand, and the base in the second organic solvent is 80-120° C., and the reaction time is 6-48 h.

[0063] In some embodiments, the solvent system used for the chiral column chromatography separation of the racemate of compound 4 is a mixed solvent of n-hexane and isopropanol, and the volume ratio of n-hexane to isopropanol is 4:1 to 200:1.

[0064] In some embodiments, the chiral column is one of IB, ID, IF and IH columns.

[0065] In step S4, in some embodiments, the base is at least one of sodium methoxide, sodium ethoxide and piperidine.

[0066] In some embodiments, the third organic solvent is at least one of methanol, ethanol and pyridine.

[0067] In some embodiments, the temperature for reacting the compound (S)-4 or compound (R)-4 with the benzyl cyanide derivative and the base in the third organic solvent is 40-120° C., and the reaction time is 6-48 h.

[0068] An embodiment of the present invention provides an application of the axially chiral circularly polarized luminescent liquid crystal compound in optical data storage, optical quantum information science, chirality recognition, and medical imaging.

[0069] The following describes it in detail through specific examples.

[0070] Example 1

[0071] Synthesis of compound 1:

[0072]

[0073] 4-(4-Hydroxyphenyl)cyclohexanone (9.00 g, 47.31 mmol) was weighed into a 250 mL round-bottom flask and evacuated three times to a nitrogen atmosphere. The flask was placed in an ice bath and ultra-dry pyridine (8.52 mL, 94.62 mmol) and ultra-dry dichloromethane (47 mL) were added to the round-bottom flask using syringes. Trifluoromethanesulfonic anhydride (10.20 mL, 56.77 mmol) and ultra-dry dichloromethane (23.7 mL) were mixed in a nitrogen-filled Erlenmeyer flask and added to the round-bottom flask using a syringe. The mixture was stirred at 0°C for 3 hours and then slowly warmed to room temperature for overnight reaction. After the reaction, the pyridine was quenched with dilute hydrochloric acid (1 mol / L, 10 mL). The organic phase was extracted three times with water and dried over anhydrous sodium sulfate. The solvent was dried by rotary evaporation, and the residue was separated and purified by column chromatography (PE:EA=10:1 v / v) to obtain a white solid (11.00 g, 72% yield).

[0074] Synthesis of compound 2:

[0075]

[0076] Triphenylphosphine (3.41 g, 13.00 mmol) and 1-iodohexane (2.30 g, 10.83 mmol) were weighed into a 250 mL two-necked flask. The system was evacuated three times to a nitrogen atmosphere. Toluene solution (50 mL) was added to the flask via syringe and stirred at 100°C for 12 hours. After the reaction, ultra-dry tetrahydrofuran (10 mL) was added and stirred for half an hour to obtain a solid-liquid mixture. Filter the mixture to obtain a white solid (3.33 g, 65% yield).

[0077] Synthesis of racemate (rac)-3 of compound 3:

[0078]

[0079] Compound 2 (2.80 g, 5.90 mmol) was weighed and added to a 100 mL round-bottom flask. The system was evacuated three times to a nitrogen atmosphere. The flask was placed in an ethyl acetate bath and ultra-dry tetrahydrofuran (10 mL) was added to the flask via syringe. The ethyl acetate bath was cooled to -78°C with liquid nitrogen. n-Butyllithium solution (2.48 mL, 6.20 mmol) was slowly added to the flask and stirred at -78°C for 1 hour. Compound 1 (2.14 g, 6.65 mmol) was dissolved in ultra-dry tetrahydrofuran (20 mL). The mixture was added to the flask via syringe and stirred at -78°C for 2 hours. The mixture was then allowed to react at room temperature for 12 hours. After the reaction, the n-Butyllithium was quenched with ultrapure water (10 mL). The mixture was then extracted with ethyl acetate and ultrapure water. The resulting organic phase solution was dried over anhydrous sodium sulfate. The solvent was dried by rotary evaporation and then purified by column chromatography (PE) to obtain a colorless liquid (1.56 g, 68% yield).

[0080] Synthesis of racemate (rac)-4 of compound 4:

[0081]

[0082] Compound 3 (0.5 g, 1.28 mmol), p-formylphenylboronic acid pinacol ester (357.56 mg, 1.54 mmol), anhydrous potassium carbonate (354.87 mg, 2.57 mmol), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (50.0 mg, 0.128 mmol), and palladium acetate (41.0 mg, 0.105 mmol) were weighed into a 50 mL round-bottom flask. The system was evacuated three times to a nitrogen atmosphere. 12 mL of ultra-dry acetonitrile solution was added to the flask via syringe and stirred at 100°C for 12 hours. After the reaction was completed, ethyl acetate (30 mL) was added to dilute the reaction mixture and extracted with saturated sodium bicarbonate solution and ethyl acetate solution. The resulting organic phase solution was dried over anhydrous sodium sulfate. The solvent was dried by rotary evaporation, and the residue was separated and purified by column chromatography (PE:EA=30:1 v / v) to obtain a white viscous solid (266.15 mg, 60% yield).

[0083] Separation of compound (S)-4 and compound (R)-4:

[0084]

[0085] The chiral separation column used was a CHIRALPAK IH column (0.46 cm ID x 15 cmL). The injection volume was 2 μL per column, and the mobile phase was n-hexane / isopropanol (95 / 5, v / v) at a flow rate of 1 mL / min. (R)-4 (0.1087 g, ee: 99.8%, retention time: 3.399 min) and (S)-4 (0.1253 g, ee: -99.9%, retention time: 4.158 min) were obtained as colorless liquids.

[0086] Synthesis of p-alkoxyphenylacetonitrile:

[0087]

[0088] 4-Hydroxyphenylacetonitrile (3.00 g, 22.53 mmol), n-decane bromide (4.15 g, 18.78 mmol), and anhydrous potassium carbonate (3.37 g, 24.41 mmol) were weighed into a 250 mL round-bottom flask and purged three times to a nitrogen atmosphere. Ultra-dry acetonitrile solution (80 mL) was added to the flask via syringe and stirred at 100°C for 12 hours. After the reaction, the anhydrous potassium carbonate solid was filtered to obtain an organic phase solution. The solvent was dried by spin drying and then purified by column chromatography (PE:DCM = 3:1 v / v) to obtain a white solid (3.33 g, 65% yield).

[0089] Synthesis of compound (R)-V:

[0090]

[0091] p-Alkoxyphenylacetonitrile (78.91 mg, 288.59 μmol) was weighed and added to a 10 mL round-bottom flask. The system was evacuated three times to a nitrogen atmosphere. Anhydrous sodium ethanol solution (19.64 mg, 288.59 μmol) and anhydrous methanol solution (0.5 mL) were syringed into the round-bottom flask. Compound (R)-4 (0.1 g, 288.59 μmol) was weighed and added to the flask. The mixture was stirred at 50°C for 24 hours. After the reaction, the mixture was extracted three times with ultrapure water and ethyl acetate. The resulting organic phase was dried over anhydrous sodium sulfate. The solvent was dried by spin-drying and purified by column chromatography (PE:EA = 20:1 v / v) to obtain a white solid (144.18 mg, 83% yield).

[0092] Synthesis of compound (S)-V:

[0093]

[0094] The p-alkoxyphenylacetonitrile (78.91 mg, 288.59 μmol) was weighed into a 10 mL round-bottom flask, and the system was replaced with nitrogen three times. The anhydrous sodium ethoxide solution (19.64 mg, 288.59 μmol) and the anhydrous methanol solution (0.5 mL) were measured and injected into the round-bottom flask with a syringe, and the compound (S)-4 (0.1 g, 288.59 μmol) was weighed into the flask and stirred at 50°C for 24 hours. After the reaction was completed, the organic phase solution was obtained by extracting with ultrapure water and ethyl acetate solution three times, and dried with anhydrous sodium sulfate. After the solvent was spun dry, the product was purified by column chromatography (PE:EA = 20:1 v / v) to obtain a white solid (144.18 mg, 83% yield).

[0095] (R)-V or (S)-V was poured into a liquid crystal cell at 150°C, and kept at this temperature for 10 minutes, then reduced to 110°C and kept for 10 minutes, and then cooled to room temperature.

[0096] The results of the CPL (circularly polarized luminescence) test are shown in Figure 1 where (R)-V shows a negative CPL signal and (S)-V shows a positive CPL signal. After (S)-V or (R)-V is heated to above 110°C and kept for ten minutes and then reduced to room temperature, the prepared compound has circularly polarized luminescence properties.

[0097] The results of the POM (polarizing optical microscope) test are shown in Figure 3 The sample shows a focal conic texture at 110°C, which can be confirmed as a smectic liquid crystal.

[0098] The results of the DSC (differential scanning calorimetry) test are shown in Figure 2 The results show that the sample has an endothermic peak at 108°C, 162°C and 174°C during the heating process, and an exothermic peak at 91°C, 162°C and 173°C during the cooling process.

[0099] In combination with the results of POM and DSC, it is shown that the liquid crystal interval of the sample is 91°C to 174°C during heating, and 108°C to 173°C during cooling.

[0100] It should be understood that the application of the present application is not limited to the above examples, and those of ordinary skill in the art can make improvements or changes according to the above description, and all such improvements and changes shall fall within the scope of protection of the appended claims of the present application.

Claims

1. An axially chiral circularly polarized luminescent liquid crystal compound, characterized in that: It has the following chemical structure: Among them, R 1 is an unsubstituted alkyl group, R 2 One selected from hydrogen and unsubstituted alkyl.

2. A method for preparing an axially chiral circularly polarized luminescent liquid crystal compound according to claim 1, characterized in that: Including steps: S1, reacting compound 1 with trifluoromethanesulfonic anhydride and a base in a halogenated hydrocarbon solvent to obtain compound 2; S2, reacting the compound 2 with a phosphorus ylide in a first organic solvent to obtain a racemate of the compound 3; S3. reacting the racemate of compound 3 with a p-formylphenylborane reagent, a palladium salt, a phosphine ligand, and a base in a second organic solvent to obtain a racemate of compound 4, and separating the racemate of compound 4 by chiral column chromatography to obtain single chiral enantiomers, namely, compound (S)-4 and compound (R)-4; S4, reacting the compound (S)-4 and the compound (R)-4 with a benzyl cyanide derivative and a base in a third organic solvent to obtain the axially chiral circularly polarized luminescent liquid crystal compounds (S)-V and (R)-V, respectively; The above synthetic route is as follows:

3. The method for preparing an axially chiral circularly polarized luminescent liquid crystal compound according to claim 2, wherein: In step S1, the base is at least one of pyridine, triethylamine and triisopropylamine; the halogenated hydrocarbon solvent is at least one of dichloromethane, dichloroethane and chloroform; The molar ratio of the compound 1 to trifluoromethanesulfonic anhydride is 1:1.2, and the molar ratio of the compound 1 to the base is 1:2; 4. The method for preparing an axially chiral circularly polarized luminescent liquid crystal compound according to claim 3, wherein: The reaction temperature of the compound 1, trifluoromethanesulfonic anhydride and the base in the halogenated hydrocarbon solvent is 0-40° C., and the reaction time is 1-24 h.

5. The method for preparing an axially chiral circularly polarized luminescent liquid crystal compound according to claim 2, wherein: In step S2, the molar ratio of compound 2 to phosphorus ylide is 1.13:1; The first organic solvent is at least one of tetrahydrofuran, methyltetrahydrofuran, diethyl ether and 1,4-dioxane.

6. The method for preparing an axially chiral circularly polarized luminescent liquid crystal compound according to claim 5, wherein: The reaction temperature of the compound 2 and the phosphorus ylide in the first organic solvent is -80-40° C., and the reaction time is 1-24 h.

7. The method for preparing an axially chiral circularly polarized luminescent liquid crystal compound according to claim 2, wherein: In step S3, the p-formylphenylboronic acid reagent is p-formylphenylboronic acid or p-formylphenylboronic acid ester; The palladium salt is at least one of palladium chloride, palladium acetate and palladium trifluoromethanesulfonate; The phosphine ligand is at least one of triphenylphosphine, 4,5-bisdiphenylphosphino-9,9-dimethylxanthene, 2-biscyclohexylphosphino-2',6'-dimethoxybiphenyl and 2-biscyclohexylphosphino-2',4',6'-triisopropylbiphenyl; The base is at least one of sodium carbonate, potassium carbonate, cesium carbonate and potassium tert-butoxide; The second organic solvent is at least one of acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and toluene; The reaction temperature of the racemate of the compound 3 with the p-formylphenylborane reagent, the palladium salt, the phosphine ligand, and the base in the second organic solvent is 80-120° C., and the reaction time is 6-48 hours.

8. The method for preparing an axially chiral circularly polarized luminescent liquid crystal compound according to claim 2, wherein: In step S3, the solvent system used for the chiral column chromatography separation of the racemate of compound 4 is a mixed solvent of n-hexane and isopropanol, and the volume ratio of n-hexane to isopropanol is 4:1 to 200:1; The chiral column is one of IB, ID, IF and IH columns.

9. The method for preparing an axially chiral circularly polarized luminescent liquid crystal compound according to claim 2, wherein: In step S4, the base is at least one of sodium methoxide, sodium ethoxide and piperidine; The third organic solvent is at least one of methanol, ethanol and pyridine; The temperature for reacting the compound (S)-4 or the compound (R)-4 with the benzyl cyanide derivative and the base in the third organic solvent is 40-120° C., and the reaction time is 6-48 hours.

10. Use of the axially chiral circularly polarized luminescent liquid crystal compound according to claim 1 in optical data storage, optical quantum information, chiral recognition and medical imaging.

Images