Facial chiral [2.2] cyclic aromatic compound, preparation method and application thereof

Abstract

The invention belongs to the technical field of fluorescent materials, and particularly relates to a planar chiral [2.2] cycloaromatic compound as well as a preparation method and application thereof, and the planar chiral [2.2] cycloaromatic compound comprises a planar chiral [2.2] cycloaryl-4-(dicyanomethylene)-4H-pyran compound with a structure as shown in a formula (I). The planar chiral [2.2] cycloaromatic compound is prepared and is modulated under the assistance of acid to obtain the white-light organic circularly polarized light-emitting solid material, the white-light material has circularly polarized light-emitting performance, a white light preparation method is simple, and the planar chiral [2.2] cycloaromatic compound is convenient to purify, high in yield and good in optical stability and can be used for preparing the white-light organic circularly polarized light-emitting solid material. The white circularly polarized luminescent material can be prepared, and the technical problems that in the prior art, a planar chiral white light circularly polarized luminescent material of a [2.2] cyclic aromatic structure is complex in preparation process, high in cost and difficult to widely apply are solved. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the technical field of fluorescent materials, and particularly relates to a planar chiral [2.2]paracyclophane compound, a preparation method thereof, and an application thereof. Background Art

[0002] Circularly polarized light (CPL) is a special polarization phenomenon, which refers to the phenomenon that chiral luminescent materials or achiral luminescent materials emit different left-handed or right-handed circularly polarized light in a chiral environment. CPL materials can directly emit CPL without using a circular polarization filter, and are gradually becoming an important way to generate circularly polarized light. They show important application prospects in the fields of 3D display, information encryption, biological coding, asymmetric synthesis, and optoelectronic detection, attracting wide attention from scientists. The performance of CPL materials is mainly characterized by two important parameters, the luminescence asymmetry factor and the luminescence quantum efficiency. Preparing white light CPL materials with both high asymmetry factor and high luminescence efficiency is a difficult point in this field.

[0003] [2.2]Paracyclophane (PCP) is a polycyclic aromatic hydrocarbon. It has a strong electron-donating ability and a distorted benzene ring structure, which can inhibit the π-π stacking interaction between molecules and improve the luminescence characteristics of [2.2]paracyclophane compounds. Introducing it into the pyranone and 4-(dicyanomethylene)-4H-pyran structures can obtain two chiral fluorescent materials. By modulating these two chiral fluorescent materials under acid assistance, a solid film of PMMA doped with a binary system can emit nearly perfect white light. This white light material can be applied to white-emitting CPL materials and has great application potential in the field of CPL materials. Therefore, we provide a planar chiral [2.2]paracyclophane compound, a preparation method thereof, and an application thereof to solve the problems of the preparation of planar chiral optofunctional organic compounds and the development of highly efficient CPL materials in the prior art. The synthesis method is simple, the purification is convenient, the yield is high, the stability is good. In addition, it does not require metal catalysis or other expensive catalysts, and the cost is low, which is suitable for wide application. Summary of the Invention

[0004] In view of the technical problems existing in the preparation of the above-mentioned planar chiral photo-functional organic compounds and the development of efficient CPL materials, the present invention provides a planar chiral [2.2]cyclophanopyranone and a planar chiral [2.2]cyclophane 4-(dicyanomethylene)-4H-pyran and a preparation method thereof. By controlling the different ratios of the two compounds, a solid white-emitting material is obtained. This white light-emitting material has circularly polarized luminescence properties, so as to solve the problems in the preparation of planar chiral photo-functional organic compounds and the development of efficient CPL materials in the prior art. The synthesis method is simple, easy to purify, has a high yield and good stability. In addition, it does not require metal catalysis or other expensive catalysts, has a low cost, and is a planar chiral [2.2]cyclophane compound and its preparation method suitable for wide application, as well as its application in white circularly polarized luminescence materials.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: A planar chiral [2.2]cyclophane compound, including a compound of planar chiral [2.2]cyclophane 4-(dicyanomethylene)-4H-pyran, which has the structure of formula (Ⅰ):

[0006]

[0007] In order to achieve the convenient preparation of planar chiral [2.2]cyclophane 4-(dicyanomethylene)-4H-pyran, a method for preparing a planar chiral [2.2]cyclophane compound is provided as follows:

[0008] Among them, the raw material for the preparation of planar chiral [2.2]cyclophane 4-(dicyanomethylene)-4H-pyran is a planar chiral cyclophanopyranone compound, and the (Rp) isomer of the planar chiral cyclophanopyranone compound has the structure shown in formula (Ⅱ):

[0009]

[0010] The (Sp) isomer has the structure shown in formula (Ⅲ):

[0011]

[0012] Based on the above, when the preparation method of this embodiment is used for preparation, the (Rp) isomer of planar chiral [2.2]cyclophane 4-(dicyanomethylene)-4H-pyran also has the structure shown in the above formula (Ⅰ), and the (Sp) isomer has the structure shown in formula (Ⅳ):

[0013]

[0014] That is to say, by using planar chiral cycloaromatic pyranones, namely planar chiral 5-acetyl-4-hydroxy[2.2]cycloarene, planar chiral [2.2]cycloarene-4-(dicyanomethylene)-4H-pyran is obtained through four-step reactions. Among them, the planar chiral 5-acetyl-4-hydroxy[2.2]cycloarene is one of (Rp)-5-acetyl-4-hydroxy[2.2]cycloarene and (Sp)-5-acetyl-4-hydroxy[2.2]cycloarene. In this example, the planar chiral [2.2]cycloarene-4-(dicyanomethylene)-4H-pyran is prepared from the planar chiral cycloaromatic pyranone compound of formula (Ⅱ), and the synthesis route is as follows:

[0015]

[0016] The present invention provides a method for preparing planar chiral [2.2]cycloarene compounds, which obtains planar chiral [2.2]cycloarene-4-(dicyanomethylene)-4H-pyran through four-step reactions. Preferably, the preparation steps include:

[0017] S1: Take planar chiral 5-acetyl-4-hydroxy[2.2]cycloarene and ethyl acetate with a molar ratio of 1:(1.2 - 1.5), and add catalyst ① thereto, and carry out a condensation reaction at 100 - 120 °C to obtain the first-step product;

[0018] S1.1: After the condensation reaction, add ice water thereto, and adjust the pH value of the reaction solution to 6 - 7 with a hydrochloric acid solution having a concentration of 1.2 mol / L;

[0019] S1.2: Precipitate the reaction solution treated in step S1.1, and carry out suction filtration, drying, and purification to obtain the first-step product as a yellow solid;

[0020] S2: Take the first-step product in step S1, and add catalyst ② thereto, and carry out a condensation reaction at 100 - 120 °C to obtain the second-step product;

[0021] S2.1: After the condensation reaction, add ice water thereto, and adjust the pH value of the reaction solution to 6 - 7 with a saturated sodium carbonate solution;

[0022] S2.2: Precipitate the reaction solution treated in step S2.1, and carry out suction filtration, drying, and purification to obtain the second-step product as a yellow solid;

[0023] S3: Take the second-step product in step S2, add malononitrile thereto, and the molar ratio of the second-step product to malononitrile is 1:(1.2 - 1.5), and add catalyst ③, and carry out a condensation reaction at 120 - 140 °C to obtain the third-step product;

[0024] S3.1: After the condensation reaction, add distilled water thereto and stir for 0.5 h;

[0025] S3.2: The reaction solution treated in step S3.1 is precipitated, and then subjected to suction filtration, drying, and purification to obtain the third product as a red solid;

[0026] S4: Take the third product in step S3, add p-dimethylaminobenzaldehyde thereto, and add catalyst ④, and carry out a condensation reaction at 120-140 °C to obtain planar chiral [2.2] paracyclophane-4-(dicyanomethylene)-4H-pyran;

[0027] S4.1: After the condensation reaction, extract with dichloromethane and rotary evaporate to remove the solvent;

[0028] S4.2: The reaction solution treated in step S4.1 is precipitated, and then subjected to suction filtration, drying, and purification to obtain planar chiral [2.2] paracyclophane-4-(dicyanomethylene)-4H-pyran as a red solid.

[0029] Preferably, in step S1, the condensation reaction is carried out in tetrahydrofuran as the solvent, the catalyst ① is a tetrahydrofuran suspension of sodium hydride, and the molar ratio of the catalyst ① to the planar chiral 5-acetyl-4-hydroxy[2.2]paracyclophane is (4-5):1.

[0030] Preferably, in step S2, the condensation reaction is carried out in acetic acid as the solvent, the catalyst ② is acetic acid and concentrated sulfuric acid, and the molar ratio of the first product to concentrated sulfuric acid is 1:(0.02-0.06).

[0031] Preferably, in step S3, the condensation reaction is carried out in acetic anhydride as the solvent, and the catalyst ③ is acetic anhydride.

[0032] Preferably, in step S4, the condensation reaction is carried out in toluene as the solvent, and the catalyst ④ is piperidine and acetic acid.

[0033] The present invention also provides the application of the planar chiral [2.2] paracyclophane compound in the field of white circularly polarized luminescent materials. Preferably, for the application of the planar chiral [2.2] paracyclophane compound, it is characterized in that 36 μL of 5×10 -4 mol / L planar chiral [2.2] paracyclophane-4-(dicyanomethylene)-4H-pyran, 30 μL of 5×10 -3 mol / L planar chiral paracyclophane pyranone compound, and 540 μL of 5×10 -4 mol / L trifluoroacetic acid are added to 2384 μL of dichloromethane solution to obtain a solution with white emission.

[0034] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0035] 1. A planar-chiral [2.2]paracyclophane compound provided by the present invention has an emission wavelength up to 616 nm and a fluorescence quantum yield of 4%. The method for preparing the planar-chiral [2.2]paracyclophane compound has a simple synthesis method, convenient purification, high yield, good stability. In addition, it does not require metal catalysis or other expensive catalysts, with low cost and is suitable for wide application. For the application of the planar-chiral [2.2]paracyclophane compound prepared by the above method, a solid white emission material is obtained by controlling the different ratios of two compounds. This white light-emitting material has circularly polarized luminescence properties, so as to solve the problems of the preparation of planar-chiral photo-functional organic compounds and the development of efficient CPL materials in the prior art. Specifically: the planar-chiral paracyclophane pyranone compound is excited by an ultraviolet light source to emit light with a peak wavelength in the range of 470 - 500 nm, and through intramolecular fluorescence resonance energy transfer (FRET), the planar-chiral [2.2]paracyclophane-4-(dicyanomethylene)-4H-pyran emits light in the range of 550 - 760 nm, generating stable white emission. This type of white light material has circularly polarized luminescence properties, and the white light configuration method is simple. The planar-chiral [2.2]paracyclophane compound is convenient to purify, has high yield and good optical stability, and can be used to prepare white circularly polarized luminescent materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 1H NMR spectrum of planar-chiral [2.2]paracyclophane-4-(dicyanomethylene)-4H-pyran provided by the present invention;

[0038] Figure 2 13C NMR spectrum of planar-chiral [2.2]paracyclophane-4-(dicyanomethylene)-4H-pyran provided by the present invention;

[0039] Figure 3 Fluorescence emission spectrum of the white light solution provided by the present invention;

[0040] Figure 4 Physical picture of the white light solution provided by the present invention;

[0041] Figure 5 CIE coordinate diagram of the white light solution provided by the present invention;

[0042] Figure 6 The fluorescence emission spectrum of the white light PMMA film provided by the present invention;

[0043] Figure 7 The physical picture of the white light PMMA film provided by the present invention;

[0044] Figure 8 The CIE coordinate diagram of the white light PMMA film provided by the present invention;

[0045] Figure 9 The circularly polarized luminescence spectra of the combination of the (Rp)-enantiomeric [2.2]paracyclophane derivative (Rp)-enantiomeric paracyclophanopyrone compound and the (Rp)-enantiomeric [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran and the (Sp)-enantiomeric [2.2]paracyclophane derivative (Sp)-enantiomeric paracyclophanopyrone compound and the (Sp)-enantiomeric [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran in different ratios provided by the present invention;

[0046] Figure 10 The circularly polarized luminescence spectra of the combination of the (Rp)-enantiomeric [2.2]paracyclophane derivative (Rp)-enantiomeric paracyclophanopyrone compound and the (Sp)-enantiomeric [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran and the (Sp)-enantiomeric [2.2]paracyclophane derivative (Sp)-enantiomeric paracyclophanopyrone compound and the (Rp)-enantiomeric [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran in different ratios provided by the present invention. Detailed implementation manners

[0047] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0048] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the present invention is not limited by the specific embodiments disclosed in the following specification.

[0049] Embodiment 1, a kind of enantiomeric [2.2]paracyclophane compound, including the Rp isomer of enantiomeric [2.2]paracyclophane-4-(dicyanomethylene)-4H-pyran has the structure shown in formula (I), and it has the structure of formula (I):

[0050]

[0051] The Sp isomer has the structure shown in formula (II):

[0052]

[0053] To achieve the convenient preparation of face-chiral [2.2] paracyclophane 4-(dicyanomethylene)-4H-pyran, a method for preparing face-chiral [2.2] paracyclophane compounds is provided as follows:

[0054] That is to say, using face-chiral paracyclophane pyranone compounds, namely face-chiral 5-acetyl-4-hydroxy[2.2] paracyclophane, through four steps of reaction to obtain face-chiral [2.2] paracyclophane-4-(dicyanomethylene)-4H-pyran. Among them, face-chiral 5-acetyl-4-hydroxy[2.2] paracyclophane is one of (Rp)-5-acetyl-4-hydroxy[2.2] paracyclophane and (Sp)-5-acetyl-4-hydroxy[2.2] paracyclophane. In this example, taking the preparation of face-chiral [2.2] paracyclophane 4-(dicyanomethylene)-4H-pyran of formula (Ⅰ) as an example, the synthesis route is as follows:

[0055]

[0056] Of course, the above-mentioned face-chiral paracyclophane pyranone compounds and preparation methods are prior art and have been recorded in the following literature [Dyes and Pigments, 2022, 205, 110491.], and the details will not be elaborated here.

[0057] In this example, the above four-step reaction to obtain face-chiral [2.2] paracyclophane-4-(dicyanomethylene)-4H-pyran includes the following preparation steps:

[0058] S1: Take face-chiral 5-acetyl-4-hydroxy[2.2] paracyclophane and ethyl acetate with a molar ratio of 1:(1.2 - 1.5), and add catalyst ① thereto, and carry out a condensation reaction at 100 - 120 °C to obtain the first-step product;

[0059] To ensure the effective preparation of the first-step product, in step S1, the condensation reaction is carried out in tetrahydrofuran as the solvent, and the condensation reaction time is 10 - 20 min. Catalyst ① is a tetrahydrofuran suspension of sodium hydride, and among them, sodium hydride is pre-treated with n-hexane; further, the molar ratio of catalyst ① to face-chiral 5-acetyl-4-hydroxy[2.2] paracyclophane is (4 - 5):1; during the process of adjusting the pH value of the reaction solution after the condensation reaction, hydrochloric acid solution can be used, and the concentration of the hydrochloric acid solution is 1.0 - 1.4 mol / L to ensure the precipitation of the condensation product in step S1. The precipitated product is in the form of a yellow solid, and then the precipitated yellow solid is subjected to suction filtration, drying, and purification steps. Among them, drying is carried out using a vacuum drying oven, and purification is carried out by silica gel column chromatography separation using a developing agent of petroleum ether / dichloromethane with a volume ratio of 1:1;

[0060] S2: Take the product of the first step in S1, add catalyst ② thereto, and carry out a condensation reaction at 100 - 120 °C to obtain the product of the second step;

[0061] To ensure the convenient preparation of the product of the second step, in S2: The condensation reaction is carried out in acetic acid as the solvent, and the reaction time of the condensation reaction is 0.5 - 1 h; Further, catalyst ② is acetic acid and concentrated sulfuric acid, and the material dosage thereof is that the molar ratio of the product of the first step to concentrated sulfuric acid is 1:(0.02 - 0.06); After the condensation reaction, adjust the pH value of the reaction solution to ensure the precipitation of the condensation product in S2. The precipitated product is in the form of a yellow solid. Subsequently, carry out the steps of suction filtration, drying, and purification on the precipitated yellow solid. Among them, drying is carried out using a vacuum drying oven, and purification is carried out by silica gel column chromatography separation using a developing agent of petroleum ether / dichloromethane with a volume ratio of 1:1;

[0062] S3: Take the product of the second step in S2, add malononitrile thereto, and the molar ratio of the product of the second step to malononitrile is 1:(1.2 - 1.5), and add catalyst ③, and carry out a condensation reaction at 120 - 140 °C to obtain the product of the third step;

[0063] To ensure the convenient preparation of the product of the third step, in S3: Catalyst ③ is acetic anhydride, the condensation reaction is carried out in acetic anhydride as the solvent, and the reaction time of the condensation reaction is 10 - 14 h; After the condensation reaction, add distilled water thereto and stir for 0.5 h to ensure the precipitation of the condensation product in S3. The precipitated product is in the form of a red solid; Subsequently, carry out the steps of suction filtration, drying, and purification on the precipitated red solid. Among them, drying is carried out using a vacuum drying oven, and purification is carried out by silica gel column chromatography separation using a developing agent of petroleum ether / dichloromethane with a volume ratio of 1:1.

[0064] S4: Take the product of the third step in S3, add p - dimethylaminobenzaldehyde thereto, and add catalyst ④, and carry out a condensation reaction at 120 - 140 °C to obtain planar chiral [2.2]paracyclophane - 4 - (dicyanomethylene)-4H - pyran;

[0065] To ensure the effective preparation of planar chiral [2.2]paracyclophane-4-(dicyanomethylene)-4H-pyran, in step S4: The third-step product and p-dimethylaminobenzaldehyde are reacted at a molar ratio of 1:(1.1 - 1.5), and the catalyst ④, namely piperidine and acetic acid, is selected; the condensation reaction is carried out in toluene as the solvent, and the reaction time of the condensation reaction is 12 - 16 h. After the condensation reaction, dichloromethane is added for extraction, and the solvent is removed by rotary evaporation. Among them, the obtained planar chiral [2.2]paracyclophane compound is in the form of a red solid. Subsequently, the steps of filtering, drying, and purification are carried out on the precipitated red solid. Among them, drying is carried out using a vacuum drying oven, and purification is carried out by silica gel column chromatography separation using a developing agent of petroleum ether / dichloromethane with a volume ratio of 1:3.

[0066] The emission wavelength of the planar chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran prepared by the above preparation method can reach 616 nm, and the fluorescence quantum yield is 4%. The CIE coordinates of the prepared white light solution are (0.32, 0.33), and the CIE coordinates of the white light material doped in the PMMA film are (0.33, 0.32). In addition, the synthesis method of this preparation method is simple, the purification is convenient, the yield is high, and the stability is good. In addition, no metal catalysis or other expensive catalysts are required, the cost is low, and it is suitable for wide application.

[0067] The above specific reaction process is described as follows:

[0068] (1) Take planar chiral 5-acetyl-4-hydroxy[2.2]paracyclophane, and under nitrogen protection, add anhydrous tetrahydrofuran to dissolve it, then add ethyl acetate to it, and then add a catalyst, and carry out a condensation reaction at 110 °C. After reacting for 15 minutes, a reaction solution is obtained.

[0069] Among them, the catalyst is a tetrahydrofuran suspension of sodium hydride, and sodium hydride is pre-washed three times with n-hexane. Further, the molar ratio of the catalyst to the planar chiral 5-acetyl-4-hydroxy[2.2]paracyclophane is 4.5:1, and the molar ratio of the planar chiral 5-acetyl-4-hydroxy[2.2]paracyclophane to ethyl acetate is 1:1.4.

[0070] (2) Add ice water to the reaction solution obtained in step (1) and adjust the pH value to 7.5 to precipitate the product. The precipitated product is in the form of a yellow solid. Among them, the pH value of the reaction solution is adjusted using a hydrochloric acid solution with a concentration of 1.2 mol / L.

[0071] (3) Filter, dry, and purify the product precipitated in step (2). Among them, drying is carried out using a vacuum drying oven, and purification is carried out by column chromatography purification, and purification is carried out by silica gel column chromatography separation using a developing agent of petroleum ether / dichloromethane with a volume ratio of 1:1.

[0072] (4) Take the separated product in step (3) and protect it with nitrogen. Add acetic acid to dissolve it, and then add a catalyst thereto and stir for 1 hour to obtain a reaction solution; wherein, the catalyst is concentrated sulfuric acid, and the molar ratio of the catalyst to the product in step (3) is 0.04:1.

[0073] (5) Add ice water to the reaction solution obtained in step (4) and adjust the pH value to 7.5 to precipitate the product. The precipitated product is in the form of a yellow solid. Among them, the pH value of the reaction solution is adjusted using saturated sodium carbonate solution.

[0074] (6) Filter, dry, and purify the product precipitated in step (5). Among them, drying is carried out using a vacuum drying oven, and purification is carried out using column chromatography purification. Moreover, silica gel column chromatography separation is carried out using a developing agent of petroleum ether / dichloromethane with a volume ratio of 1:1.

[0075] (7) Take the separated product in step (6) and protect it with nitrogen. Add acetic anhydride to dissolve it, and then add malononitrile thereto and carry out a condensation reaction at 130 °C. After reacting for 12 h, a reaction solution is obtained; wherein, the molar ratio of the product in step (6) to malononitrile is 1:1.4.

[0076] (8) Add water to the reaction solution obtained in step (7) and distill for 0.5 h to precipitate the product. Filter, dry, and purify the product. Among them, drying is carried out using a vacuum drying oven, and purification is carried out using column chromatography purification. Moreover, silica gel column chromatography separation is carried out using a developing agent of petroleum ether / dichloromethane with a volume ratio of 1:1.

[0077] (9) Take the separated product in step (8) and protect it with nitrogen. Add anhydrous toluene to dissolve it, and then add 4-dimethylaminobenzaldehyde thereto. Then, add a catalyst thereto and carry out a condensation reaction at 130 °C. After reacting for 14 h, a reaction solution is obtained; wherein, the catalyst is a solution of piperidine and acetic acid in equal volume, the molar ratio of the catalyst to the separated product in step (8) is 0.03:1, and the molar ratio of the separated product in step (8) to 4-dimethylaminobenzaldehyde is 1:1.3.

[0078] It should be noted that in step (1), when the facial chiral 5-acetyl-4-hydroxy[2.2]paracyclophane is (Rp)-5-acetyl-4-hydroxy[2.2]paracyclophane, the obtained facial chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran is the Rp isomer; when the facial chiral 5-acetyl-4-hydroxy[2.2]paracyclophane is (Sp)-5-acetyl-4-hydroxy[2.2]paracyclophane, the obtained facial chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran is the Sp isomer.

[0079] Example 2: The planar-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran in this example is the same as that in Example 1. The Rp isomer of the planar-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran has the structure shown in Formula (I), and the Sp isomer has the structure shown in Formula (II).

[0080] The preparation method of the planar-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran in this example is the same as that in Example 1, except that:

[0081] In step (1), the molar ratio of the catalyst to the planar-chiral 5-acetyl-4-hydroxy[2.2]paracyclophane is 4:1, the molar ratio of the planar-chiral 5-acetyl-4-hydroxy[2.2]paracyclophane to the ethyl acetate is 1:1.2. In step (4), the molar ratio of the catalyst to the product of step (3) is 0.02:1. In step (7), the molar ratio of the product of step (6) to the malononitrile is 1:1.2, and in step (9), the molar ratio of the catalyst to the separated product in step (8) is 0.01:1. In step (8), the molar ratio of the separated product to the 4-dimethylaminobenzaldehyde is 1:1.1.

[0082] Example 3: The planar-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran in this example is the same as that in Example 1. The Rp isomer of the planar-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran has the structure shown in Formula (I), and the Sp isomer has the structure shown in Formula (II).

[0083] The preparation method of the planar-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran in this example is the same as that in Example 1, except that: In step (1), the molar ratio of the catalyst to the planar-chiral 5-acetyl-4-hydroxy[2.2]paracyclophane is 5:1, the molar ratio of the planar-chiral 5-acetyl-4-hydroxy[2.2]paracyclophane to the ethyl acetate is 1:1.5. In step (4), the molar ratio of the catalyst to the product of step (3) is 0.06:1. In step (7), the molar ratio of the product of step (6) to the malononitrile is 1:1.5. In step (9), the molar ratio of the catalyst to the separated product in step (8) is 0.05:1. In step (8), the molar ratio of the separated product to the 4-dimethylaminobenzaldehyde is 1:1.5.

[0084] Example 4: The planar-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran in this example is the same as that in Example 1. The Rp isomer of the planar-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran has the structure shown in Formula (I), and the Sp isomer has the structure shown in Formula (II).

[0085] The preparation method of the planar chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran in this example is the same as that in Example 1, except that: in steps (1), (4), (7) and (9), nitrogen protection is not used.

[0086] Example 5: The planar chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran in this example is the same as that in Example 1. The Rp isomer of the planar chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran has the structure shown in formula (I), and the Sp isomer has the structure shown in formula (II).

[0087] The preparation method of the planar chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran in this example is the same as that in Example 1, except that: in step (9), the catalyst is one of piperidine and acetic acid, and the molar ratio of the catalyst to the separated product is 0.1:1.

[0088] To verify the technical effects of the planar chiral [2.2]paracyclophane compounds obtained by the preparation method provided in this example, the following tests were carried out:

[0089] I. Proton nuclear magnetic resonance spectrum

[0090] The proton nuclear magnetic resonance spectra of the planar chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran obtained in Examples 1-5 were measured by nuclear magnetic resonance, as Figure 1 shown. It is the proton nuclear magnetic resonance spectrum of the planar chiral [2.2]paracyclophane compound. In the proton nuclear magnetic resonance spectrum of the planar chiral [2.2]paracyclophane compound: 1 H NMR(500MHz, CDCl3)δ7.63(d, J = 15.7Hz, 1H), 7.56(d, J = 8.5Hz, 2H), 6.88(s, 1H), 6.82(d, J = 7.7Hz, 1H), 6.76(d, J = 7.9Hz, 3H), 6.72(d, J = 15.7Hz, 1H), 6.67(dd, J = 7.9, 1.9Hz, 1H), 6.62(dd, J = 7.9, 1.9Hz, 1H), 6.25(dd, J = 7.9, 1.9Hz, 1H), 6.13(dd, J = 7.9, 1.9Hz, 1H), 3.71–3.65(m, 1H), 3.60(ddd, J = 15.3, 9.6, 6.1Hz, 1H), 3.42(ddd, J = 14.1, 9.6, 3.3Hz, 1H), 3.29–3.22(m, 1H), 3.09(s, 6H), 3.08–3.03(m, 2H), 2.85(dddd, J = 37.2, 13.5, 10.1, 6.4Hz, 2H).

[0091] II. Carbon nuclear magnetic resonance spectrum

[0092] The facial-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran obtained in Examples 1-5 was subjected to carbon nuclear magnetic resonance measurement, as Figure 2 shown. It is the carbon spectrum of a facial-chiral [2.2]paracyclophane compound. In the carbon spectrum of the facial-chiral [2.2]paracyclophane compound: 13 C NMR (126 MHz, CDCl3) δ 157.0, 155.0, 152.7, 151.9, 141.4, 139.4, 139.3, 139.0, 139.0, 133.6, 132.2, 131.7, 129.9, 129.9, 127.6, 127.3, 122.6, 118.9, 117.0, 116.1, 113.5, 112.1, 105.3, 64.1, 40.2, 36.3, 35.7, 34.1, 31.3.

[0093] III. Preparation Experiment of White Light Emitting Materials

[0094] Take the facial-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran prepared in Experimental Example 1 and dissolve it in dichloromethane solution to prepare a 5×10 -4 mol / L solution. According to the records in the existing literature, prepare a facial-chiral paracyclophanepyranone compound and dissolve it in dichloromethane solution to prepare a 5×10 -3 mol / L solution. Dissolve trifluoroacetic acid in dichloromethane solution to prepare a 5×10 -4 mol / L solution.

[0095] Take 36 μL of 5×10 -4 mol / L facial-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran, 30 μL of 5×10 -3 mol / L facial-chiral paracyclophanepyranone compound, and 540 μL of 5×10 -4 mol / L trifluoroacetic acid and add them to 2384 μL of dichloromethane solution to obtain a solution with white emission.

[0096] Measure the fluorescence spectrum signal and the physical diagram of white light of the solution according to the above method, as Figure 3 、 Figure 4 shown; The CIE chromaticity coordinate diagram is as Figure 5 shown, where 1a is the facial-chiral paracyclophanepyranone compound and 1b is the facial-chiral [2.2]paracyclophane 4-(dicyanomethylene)-4H-pyran.

[0097] Take 5×10 -436 μL of planar-chiral [2.2] paracyclophane 4-(dicyanomethylene)-4H-pyran at mo l / L, 30 μL of planar-chiral paracyclophane pyranone compounds at 5×10 -3 mol / L, and 1000 μL of trifluoroacetic acid at mo l / L were added to a dichloromethane solution of PMMA at a concentration of 10 mg / mL. After standing for the solvent to evaporate completely, a PMMA film with white emission was obtained. -4 According to the above method, the fluorescence spectrum signal and white light physical map of the PMMA film were measured, as shown in

[0098] ; The CI E chromaticity coordinate diagram is shown in Figure 6 、 Figure 7 ; Among them, 1a is the planar-chiral paracyclophane pyranone compound, and 1b is planar-chiral [2.2] paracyclophane 4-(dicyanomethylene)-4H-pyran. Figure 8

[0099] Specifically: Planar-chiral [2.2] paracyclophane 4-(dicyanomethylene)-4H-pyran has strong and stable fluorescence emission in dichloromethane solution. By adding it, planar-chiral paracyclophane pyranone compounds and trifluoroacetic acid in proportion, a solution with white light emission can be obtained. That is to say: A solid PMMA material with white circularly polarized luminescence can be obtained through different ratio combinations.

[0100] IV. Circularly Polarized Luminescence Spectrum Experiment of White Light Materials

[0101] The circularly polarized luminescence spectrum of the above PMMA film was measured using a circularly polarized fluorescence spectrometer. Among them, the measurement conditions of the spectral data are as follows: The excitation wavelength is 375 nm.

[0102] Figure 9 Among them, Figure 10 、 are the circularly polarized luminescence data of PMMA white light films configured according to different planar-chiral isomers of planar-chiral [2.2] paracyclophane 4-(dicyanomethylene)-4H-pyran and planar-chiral paracyclophane pyranone compounds. Among them, 1a is the planar-chiral paracyclophane pyranone compound, and 1b is planar-chiral [2.2] paracyclophane 4-(dicyanomethylene)-4H-pyran;

[0103] ​​

[0104] V. Yield of Facial Chiral [2.2] Paracyclophane 4-(Dicyanomethylene)-4H-Pyran

[0105] The preparation of facial chiral [2.2] paracyclophane 4-(dicyanomethylene)-4H-pyran was carried out respectively according to the preparation methods in Examples 1-5. After it was separated, it was weighed and its separation yield was calculated. The calculation results are shown in Table 1 below:

[0106] Table 1 Calculation Results of Yield:

[0107] Group Yield (%) Example 1 43 Example 2 40 Example 3 37 Example 4 21 Example 5 27

[0108] The above are only the preferred embodiments of the present invention, and are not limitations to the present invention in other forms. Any person skilled in the art may use the technical content disclosed above to make changes or modifications into equivalent embodiments with equivalent changes and apply them to other fields. However, as long as it does not depart from the technical solution content of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A face-chiral [2.2] paracyclophane compound, characterized in that, A compound including a planar chiral [2.2]paracyclophane-4-(dicyanomethylene)-4H-pyran, which has the structure of formula (Ⅰ):

2. The method for preparing the planar chiral [2.2] paracyclophane compound according to claim 1, wherein The planar chiral [2.2]paracyclophane-4-(dicyanomethylene)-4H-pyran is obtained through four-step reactions, including the following preparation steps: S1: Take planar chiral 5-acetyl-4-hydroxy[2.2]paracyclophane and ethyl acetate with a molar ratio of 1:(1.2 - 1.5), and add catalyst ① thereto, and conduct a condensation reaction at 100 - 120 °C to obtain the first-step product; S1.1: After the condensation reaction, add ice water thereto, and adjust the pH value of the reaction solution to 6 - 7 with a hydrochloric acid solution having a concentration of 1.2 mol / L; S1.2: Precipitate the reaction solution treated in step S1.1, and conduct suction filtration, drying, and purification to obtain the first-step product as a yellow solid; S2: Take the first-step product in step S1, and add catalyst ② thereto, and conduct a condensation reaction at 100 - 120 °C to obtain the second-step product; S2.1: After the condensation reaction, add ice water thereto, and adjust the pH value of the reaction solution to 6 - 7 with a saturated sodium carbonate solution; S2.2: Precipitate the reaction solution treated in step S2.1, and conduct suction filtration, drying, and purification to obtain the second-step product as a yellow solid; S3: Take the second-step product in step S2, add malononitrile thereto, and the molar ratio of the second-step product to malononitrile is 1:(1.2 - 1.5), and add catalyst ③, and conduct a condensation reaction at 120 - 140 °C to obtain the third-step product; S3.1: After the condensation reaction, add distilled water thereto and stir for 0.5 h; S3.2: Precipitate the reaction solution treated in step S3.1, and conduct suction filtration, drying, and purification to obtain the third-step product as a red solid; S4: Take the third-step product in step S3, add p-dimethylaminobenzaldehyde thereto, and add catalyst ④, and conduct a condensation reaction at 120 - 140 °C to obtain planar chiral [2.2]paracyclophane-4-(dicyanomethylene)-4H-pyran; S4.1: After the condensation reaction, extract with dichloromethane and rotary evaporate to remove the solvent; S4.2: Precipitate the reaction solution treated in step S4.1, and conduct suction filtration, drying, and purification to obtain planar chiral [2.2]paracyclophane-4-(dicyanomethylene)-4H-pyran as a red solid.

3. The method for preparing a face-chiral [2.2] paracyclophane compound according to claim 2, wherein, In step S1, the condensation reaction is carried out in tetrahydrofuran as the solvent, the catalyst ① is a tetrahydrofuran suspension of sodium hydride, and the molar ratio of the catalyst ① to the planar chiral 5-acetyl-4-hydroxy[2.2]paracyclophane is (4 - 5):

1.

4. The method for preparing axially chiral [2.2]paracyclophane compounds according to claim 3, characterized in that, In step S2, the condensation reaction is carried out in acetic acid as the solvent, the catalyst ② is acetic acid and concentrated sulfuric acid, and the molar ratio of the first-step product to concentrated sulfuric acid is 1:(0.02 - 0.06).

5. The method for preparing the planar chiral [2.2]paracyclophane compound according to claim 4, wherein, In step S3, the condensation reaction is carried out in acetic anhydride as the solvent, and the catalyst ③ is acetic anhydride.

6. The method for preparing a planar chiral [2.2]paracyclophane compound according to claim 5, wherein In step S4, the condensation reaction is carried out in toluene as the solvent, and the catalyst ④ is piperidine and acetic acid.

7. Use of the planar chiral [2.2] paracyclophane compound according to claim 1, characterized in that, Take 5×10 - 4 mol / L planar chiral [2.2]paracyclophane-4-(dicyanomethylene)-4H-pyran 36 μL, 5×10 -3 mol / L planar chiral paracyclophane pyranone compound 30 μL and 5×10 -4 mol / L trifluoroacetic acid 540 μL are added to 2384 μL dichloromethane solution to obtain a solution with white emission.

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