A chiral cyclophane molecule BinapoBox·4PF6 and its preparation method and application

Abstract

A chiral cyclophane molecule BinapoBox·4PF6 and its preparation method and application belong to the field of macrocyclic molecule research, specifically to a chiral cyclophane molecule and its preparation method and application. The present invention aims to solve the problems of high synthesis cost of existing chiral aromatic dyes and complex process of inducing chirality of achiral compounds. The chiral cyclophane molecule BinapoBox·4PF6 of the present invention has the general structural formula of C 92 H 70 F 24 N4O2P6. The chiral cyclophane molecule BinapoBox·4PF6 exhibits excellent binding ability and unique fluorescent properties with aromatic dyes, making it an ideal chiral host material for preparing chiral host-achiral guest CPL materials. This method avoids tedious synthetic modifications and expensive liquid crystal materials, allowing for large-scale production, significantly reducing costs. This chiral cyclophane molecule is a recyclable and versatile chiral cyclophane product.

Description

Technical Field

[0001] The present invention belongs to the field of macrocyclic molecule research, and specifically relates to a chiral cyclophane molecule, a preparation method and application thereof; Background Art

[0002] The use of macrocyclic synthetic receptors for molecular recognition is an important research area in supramolecular chemistry; pioneering examples on this topic date back to the 1980s. Macrocyclic models are key to further understanding the remarkable properties exhibited by proteins: high binding affinity, superior binding selectivity, and extreme catalytic performance.

[0003] In supramolecular chemistry, cyclophane is an artificial receptor, which is a cage-type macrocyclic compound formed by connecting two or more aromatic compounds with a short spacer (bridge). By changing or regulating the type of aromatic compound, the type and number of bridges, it is easy to give cyclophane physical and chemical properties such as hydrogen bonding, electrostatic interaction, hydrophobic interaction, π-π, ion-π interaction, etc., so that it combines some characteristics of crown ethers, cyclodextrins and multidentate ligands. With the development of cyclophane chemistry, more and more cyclophane compounds, especially chiral cyclophane compounds (belonging to CPL materials) have been synthesized. Due to their many properties such as molecular recognition and optical properties, they have been used in host-guest chemistry, analytical chemistry, catalysts, artificial enzymes, drugs, etc. Cyclophanes hold enormous potential for application in fields such as chemistry and materials science. Cyclophanes are numerous, diverse, and highly applicable. The design and synthesis of cyclophanes with specialized functions remains a hot topic in future research. Furthermore, cyclophanes possess multiple active sites and cavity sizes, enabling specific substrate recognition, providing a viable foundation for the development of dynamic chemistry, dynamic materials, smart materials, nanomaterials, chemistry and art, and supramolecular polymer chemistry. Although numerous cyclophanes have been synthesized, limited by current synthetic methods, reports of chiral cyclophanes are rare. However, we believe that with the deepening of research in chiral cyclophane chemistry, challenges in its development will be overcome, and chiral cyclophane chemistry will gradually become a significant research area. Currently, the synthesis of chiral aromatic dyes still relies on liquid-phase separation and asymmetric synthesis, making chiral compounds extremely expensive. Therefore, the development of novel chiral compounds that induce chirality through non-covalent bonds remains a hot topic in chiral chemistry. In particular, the induction of chirality in achiral luminophores to prepare multicolor CPLs has attracted considerable attention. Currently, three approaches are commonly used to induce chirality in achiral aromatic dyes: modification of chiral organic dyes, supramolecular assemblies, and liquid crystal doping. For example, to obtain organic CPL (circularly polarized luminescence)-active materials, the most common approach is to covalently bind a chiral moiety to a luminophore. However, tedious synthetic processes are sometimes unavoidable. Furthermore, the CPL activity of the resulting CPL materials is unpredictable. Similarly, inorganic CPL-active materials also require a difficult inorganic synthesis by loading a chiral source onto prefabricated nanomaterials. Therefore, the development of a simple and universal method for the production of CPL-active materials is of great significance. Summary of the Invention

[0004] In order to solve the problems of high synthesis cost of existing chiral aromatic dyes and complex process of inducing chirality of achiral compounds, the present invention proposes a chiral cyclophane molecule BinapoBox·4PF6 and its preparation method and application.

[0005] The structural formula of the chiral cyclophane molecule BinapoBox·4PF6 of the present invention is:

[0006]

[0007] The chiral cyclophane molecule BinapoBox·4PF6 has the general structural formula of C 92 H 70 F 24 N4O2P6.

[0008] The preparation method of the chiral cyclophane molecule BinapoBox·4PF6 is carried out according to the following steps:

[0009] Step 1, synthesis of 1,4-bis(bromomethyl)benzene:

[0010] 7.1-7.2 g of N-bromosuccinimide and 160-170 mg of azobisisobutyronitrile were added to 60-70 mL of p-xylene in acetonitrile; after stirring under reflux for 16-17 hours, the mixture was evaporated in vacuo and purified by chromatography to obtain 1,4-bis(bromomethyl)benzene;

[0011] The ratio of the mass of xylene to the volume of acetonitrile in the xylene-acetonitrile solution is 2-3 g: 60-90 mL;

[0012] Step 2: Synthesis of 4,4'-di(pyridin-4-yl)-1,1'-biphenyl:

[0013] 15-20 mL of dry N,N-dimethylformamide was degassed by bubbling N2 for 2 h, followed by the addition of 468-500 mg of 4,4'-dibromo-1,1'-biphenyl, 80-90 mg of Pd(PPh3)4, 400-500 mg of 4-pyridineboronic acid and 2.5-3.0g Cs2CO3, heating the mixture to 110°C and maintaining for 24 hours to form a suspension, evaporating the solvent, and extracting the remaining residue with chloroform. The extracted product is washed with K2CO3 solution and saturated brine in sequence, and the washed product is dried with MgSO4, and then the chloroform is removed by evaporation and concentration. 5-10mL of dichloromethane is added to dissolve the solid product obtained by evaporation and concentration, and 100-120mL of n-hexane is added to the obtained solution for precipitation. The obtained solid product is washed with 10-20mL of n-hexane and recrystallized with 10-20mL of ethyl acetate to obtain 4,4'-di(pyridin-4-yl)-1,1'-biphenyl;

[0014] Step 3: Synthesis of (R)-4,4-bis-4-pyridyl-1,1'-binaphthyl-2,2'-bisdiphenylphosphine:

[0015] 3.25-3.5 g of (R)-4,4-dibromo-1,1'-binaphthyl-2,2'-bisdiphenylphosphine, 0.07-0.10 g of Pd(PPh3)4, 1.08-1.20 g of 4-pyridineboronic acid, and 2.21-2.50 g of K2CO3 were placed in a mixture of 150-200 mL of 1,4-dioxane and water, and heated under reflux for 7 days in a nitrogen atmosphere. The resulting organic phase was washed with 275-300 mL of H2O. After evaporating the solvent, the remaining solid was recrystallized from propan-2-ol;

[0016] The volume ratio of 1,4-dioxane to water in the mixed solution of 1,4-dioxane and water is 2:1;

[0017] Step 4: Synthesis of bis(4-bromomethylbenzyl)(4,4′-(4,4′-biphenyl)bipyridinium-1-ium)bis(hexafluorophosphate):

[0018] ① In a round-bottom three-necked flask, add 5.14-5.2 g of 1,4-bis(bromomethyl)benzene prepared in step 1 to a mixture of 240 mL of CH2Cl2 and acetonitrile, heat and stir in a 50°C oil bath until all the solid matter is dissolved; then increase the oil bath temperature to 90°C to obtain a reaction solution;

[0019] The volume ratio of CH2Cl2 to acetonitrile in the mixture of CH2Cl2 and acetonitrile is 1:1;

[0020] ②. Add 0.6-0.7 g of 4,4'-di(pyridin-4-yl)-1,1'-biphenyl prepared in step 2 to 120-150 mL of acetonitrile, and then titrate into the reaction solution obtained in step ① within 4 hours. After heating under reflux for 24-30 hours, cool to room temperature, collect the yellow precipitate by filtration, and wash with CH2Cl2 to obtain a yellow solid; dissolve the yellow solid in 1-1.5 L of methanol below room temperature, and then add 400-500 mg of NH4PF6 and 1 L of H2O below room temperature to obtain bis(4-bromomethylbenzyl)(4,4'-(4,4'-biphenyl)bipyridin-1-ium)bis(hexafluorophosphate) after precipitation;

[0021] Step 5. Synthesis of chiral cyclophane molecule BinapoBox·4PF6:

[0022] 0.11-0.12 g of (R)-4,4-bis-4-pyridyl-1,1'-binaphthyl-2,2'-bisdiphenylphosphine prepared in step 3, 0.35-0.40 g of bis(4-bromomethylbenzyl)(4,4'-(4,4'-biphenyl)bipyridinium-1-ium)bis(hexafluorophosphate) prepared in step 4 and 0.027-0.030 g of tetrabutylammonium iodide were added to 180-200 mL of dry acetonitrile and stirred at 80-90 °C for 72-80 min. 80h, then add 3mL of concentrated hydrochloric acid to stop the reaction, filter and collect the precipitate, then wash the precipitate with acetone and CH2Cl2 in sequence to remove residual tetrabutylammonium iodide, dissolve the precipitate in 500-600mL of 60℃ methanol, and then add an aqueous solution of NH4PF6 to obtain a solid product. After the reaction, the precipitate is collected and filtered, and the product is dissolved in 10mL of acetonitrile to obtain a reaction solution, and the reaction solution is placed in an isopropyl ether vapor environment for 2-3 crystallizations to complete.

[0023] The chiral cyclophane molecule BinapoBox·4PF6 is used to combine with aromatic dyes to prepare CPL active materials. The preparation method is carried out according to the following steps:

[0024] 1. mixing the chiral cyclophane and a solvent to obtain a chiral cyclophane solution;

[0025] The solvent is acetonitrile or methanol;

[0026] The concentration of the chiral cyclophane solution is 1×10 -6 ~1×10 -2 mol / L;

[0027] 2. Dissolve the aromatic dye in the same solvent as in step 1, and then add it to the chiral cyclophane solution prepared in step 1 to complete the preparation of the CPL active material;

[0028] The concentration of the aromatic dye is 0.01-0.1 mol / L;

[0029] The molar ratio of the aromatic dye to the chiral cyclophane is (1-4):1.

[0030] The principles and beneficial effects of the present invention are:

[0031] 1. The chiral cyclophane molecule BinapoBox·4PF6 induces chirality by: the unique box-like structure of the chiral cyclophane molecule effectively binds to aromatic molecules through π-π interactions. Rotation of the chiral binaphthol unit of the cyclophane transfers axial chirality to the aromatic dye, thereby achieving chiral induction and preparing materials with chiral optical properties.

[0032] 2. The chiral cyclophane molecule BinapoBox·4PF6 of the present invention has excellent binding ability and unique fluorescent properties with aromatic dyes, making it an excellent chiral host material for preparing chiral host-achiral guest assembly (CPL) materials. The present invention avoids tedious synthetic modifications and also avoids expensive liquid crystal materials. It can be prepared in batches by scaling up equivalent quantities, greatly reducing costs. Furthermore, because the chiral cyclophane molecule BinapoBox·4PF6 of the present invention uses non-covalent bonding to induce guest chirality, guest replacement is less difficult. Organic solvent washing and replacement of different guest molecules can be achieved for recycling. It is also suitable for most aromatic small molecule dyes, making it a recyclable and versatile new chiral cyclophane product.

[0033] 3. The chiral cyclophane molecule BinapoBox·4PF6 of the present invention is an organic small molecule with readily available raw materials and low preparation cost. Compared with inorganic nanomaterials, organic synthesis modification, liquid crystal doping, etc., it can significantly reduce the preparation cost of chiral optically active materials.

[0034] 4. The chiral cyclophane molecule BinapoBox·4PF6 of the present invention has a box-like structure, which enables it to spatially identify aromatic hydrocarbons. That is, the chiral cyclophane molecule can be combined with aromatic hydrocarbons to form cyclophane-aromatic hydrocarbons. The CPL of cyclophane-aromatic hydrocarbons can be compared with the CPL of the chiral cyclophane molecule to achieve qualitative analysis of aromatic compounds. When the chiral cyclophane molecule BinapoBox·4PF6 combines with different aromatic hydrocarbons, the dihedral angle information of the cyclophane binaphthyl part will change, which will lead to changes in the CPL spectrum, causing g lum The chiral information of each aromatic hydrocarbon on binaphthyl changes differently, which provides a strong accuracy in the qualitative analysis of aromatic hydrocarbons. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The CD absorption change diagram of cyclophane combined with different equivalents of 4-(perylene-3-yl)pyridine dye guest;

[0036] Figure 2 This is the fluorescence spectrum change diagram (PL spectrum) of cyclophane combined with different equivalents of 4-(perylene-3-yl)pyridine dye guests. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any reasonable combination of the specific implementation methods.

[0038] Specific embodiment 1: The structural formula of the chiral cyclophane molecule BinapoBox·4PF6 in this embodiment is:

[0039]

[0040] The chiral cyclophane molecule BinapoBox·4PF6 has the general structural formula of C 92 H 70 F 24 N4O2P6.

[0041] 1. The principle of chiral cyclophane induction using the BinapoBox·4PF6 molecule in this embodiment is that the unique box-shaped structure of the chiral cyclophane molecule can effectively bind to aromatic molecules through π-π interactions. Rotation of the chiral binaphthol unit in the cyclophane transfers axial chirality to the aromatic dye, thereby achieving chiral induction and preparing materials with chiral optical properties.

[0042] 2. The chiral cyclophane molecule BinapoBox·4PF6 of this embodiment has excellent binding ability and unique fluorescent properties with aromatic dyes, making it an excellent chiral host material for preparing chiral host-achiral guest assembly CPL materials. This embodiment avoids tedious synthetic modifications and also avoids expensive liquid crystal materials. It can be prepared in batches by scaling up equivalent quantities, greatly reducing costs. Furthermore, because the chiral cyclophane molecule BinapoBox·4PF6 of this embodiment uses non-covalent bonds to induce guest chirality, guest replacement is less difficult. It can be washed with organic solvents and replaced with different guest molecules for recycling. It is also suitable for most aromatic small molecule dyes, making it a recyclable and versatile new chiral cyclophane product.

[0043] 3. The chiral cyclophane molecule BinapoBox·4PF6 in this embodiment is an organic small molecule. The raw materials for its preparation are easily available and the preparation cost is low. Compared with inorganic nanomaterials, organic synthesis modification, liquid crystal doping, etc., the preparation cost of chiral optically active materials can be greatly reduced.

[0044] 4. The chiral cyclophane molecule BinapoBox·4PF6 in this embodiment has a box-like structure, which enables it to spatially identify aromatic hydrocarbons. That is, the chiral cyclophane molecule can be combined with aromatic hydrocarbons to form cyclophane-aromatic hydrocarbons. The CPL of cyclophane-aromatic hydrocarbons can be compared with the CPL of the chiral cyclophane molecule to achieve qualitative analysis of aromatic hydrocarbon compounds. When the chiral cyclophane molecule BinapoBox·4PF6 combines with different aromatic hydrocarbons, the dihedral angle information of the cyclophane binaphthyl part will change, which will lead to changes in the CPL spectrum, causing g lum The chiral information of each aromatic hydrocarbon on binaphthyl changes differently, which provides a strong accuracy in the qualitative analysis of aromatic hydrocarbons.

[0045] Specific embodiment 2: The preparation method of the chiral cyclophane molecule BinapoBox·4PF6 in this embodiment is carried out according to the following steps:

[0046] Step 1, synthesis of 1,4-bis(bromomethyl)benzene:

[0047] 7.1-7.2 g of N-bromosuccinimide and 160-170 mg of azobisisobutyronitrile were added to 60-70 mL of p-xylene in acetonitrile; after stirring under reflux for 16-17 hours, the mixture was evaporated in vacuo and purified by chromatography to obtain 1,4-bis(bromomethyl)benzene;

[0048] The ratio of the mass of xylene to the volume of acetonitrile in the xylene-acetonitrile solution is 2-3 g: 60-90 mL;

[0049] Step 2: Synthesis of 4,4'-di(pyridin-4-yl)-1,1'-biphenyl:

[0050] 15-20 mL of dry N,N-dimethylformamide was degassed by bubbling N2 for 2 h, followed by the addition of 468-500 mg of 4,4'-dibromo-1,1'-biphenyl, 80-90 mg of Pd(PPh3)4, 400-500 mg of 4-pyridineboronic acid and 2.5-3.0g Cs2CO3, heating the mixture to 110°C and maintaining for 24 hours to form a suspension, evaporating the solvent, and extracting the remaining residue with chloroform. The extracted product is washed with K2CO3 solution and saturated brine in sequence, and the washed product is dried with MgSO4, and then the chloroform is removed by evaporation and concentration. 5-10mL of dichloromethane is added to dissolve the solid product obtained by evaporation and concentration, and 100-120mL of n-hexane is added to the obtained solution for precipitation. The obtained solid product is washed with 10-20mL of n-hexane and recrystallized with 10-20mL of ethyl acetate to obtain 4,4'-di(pyridin-4-yl)-1,1'-biphenyl;

[0051] Step 3: Synthesis of (R)-4,4-bis-4-pyridyl-1,1'-binaphthyl-2,2'-bisdiphenylphosphine:

[0052] 3.25-3.5 g of (R)-4,4-dibromo-1,1'-binaphthyl-2,2'-bisdiphenylphosphine, 0.07-0.10 g of Pd(PPh3)4, 1.08-1.20 g of 4-pyridineboronic acid, and 2.21-2.50 g of K2CO3 were placed in a mixture of 150-200 mL of 1,4-dioxane and water, and heated under reflux for 7 days in a nitrogen atmosphere. The resulting organic phase was washed with 275-300 mL of H2O. After evaporating the solvent, the remaining solid was recrystallized from propan-2-ol;

[0053] The volume ratio of 1,4-dioxane to water in the mixed solution of 1,4-dioxane and water is 2:1;

[0054] Step 4: Synthesis of bis(4-bromomethylbenzyl)(4,4′-(4,4′-biphenyl)bipyridinium-1-ium)bis(hexafluorophosphate):

[0055] ① In a round-bottom three-necked flask, add 5.14-5.2 g of 1,4-bis(bromomethyl)benzene prepared in step 1 to a mixture of 240 mL of CH2Cl2 and acetonitrile, heat and stir in a 50°C oil bath until all the solid matter is dissolved; then increase the oil bath temperature to 90°C to obtain a reaction solution;

[0056] The volume ratio of CH2Cl2 to acetonitrile in the mixture of CH2Cl2 and acetonitrile is 1:1;

[0057] ②. Add 0.6-0.7 g of 4,4'-di(pyridin-4-yl)-1,1'-biphenyl prepared in step 2 to 120-150 mL of acetonitrile, and then titrate into the reaction solution obtained in step ① within 4 hours. After heating under reflux for 24-30 hours, cool to room temperature, collect the yellow precipitate by filtration, and wash with CH2Cl2 to obtain a yellow solid; dissolve the yellow solid in 1-1.5 L of methanol below room temperature, and then add 400-500 mg of NH4PF6 and 1 L of H2O below room temperature to obtain bis(4-bromomethylbenzyl)(4,4'-(4,4'-biphenyl)bipyridin-1-ium)bis(hexafluorophosphate) after precipitation;

[0058] Step 5. Synthesis of chiral cyclophane molecule BinapoBox·4PF6:

[0059] 0.11-0.12 g of (R)-4,4-bis-4-pyridyl-1,1'-binaphthyl-2,2'-bisdiphenylphosphine prepared in step 3, 0.35-0.40 g of bis(4-bromomethylbenzyl)(4,4'-(4,4'-biphenyl)bipyridinium-1-ium)bis(hexafluorophosphate) prepared in step 4 and 0.027-0.030 g of tetrabutylammonium iodide were added to 180-200 mL of dry acetonitrile and stirred at 80-90 °C for 72-80 min. 80h, then add 3mL of concentrated hydrochloric acid to stop the reaction, filter and collect the precipitate, then wash the precipitate with acetone and CH2Cl2 in sequence to remove residual tetrabutylammonium iodide, dissolve the precipitate in 500-600mL of 60℃ methanol, and then add an aqueous solution of NH4PF6 to obtain a solid product. After the reaction, the precipitate is collected and filtered, and the product is dissolved in 10mL of acetonitrile to obtain a reaction solution, and the reaction solution is placed in an isopropyl ether vapor environment for 2-3 crystallizations to complete.

[0060] 1. The principle of chiral cyclophane induction using the BinapoBox·4PF6 molecule in this embodiment is that the unique box-shaped structure of the chiral cyclophane molecule can effectively bind to aromatic molecules through π-π interactions. Rotation of the chiral binaphthol unit in the cyclophane transfers axial chirality to the aromatic dye, thereby achieving chiral induction and preparing materials with chiral optical properties.

[0061] 2. The chiral cyclophane molecule BinapoBox·4PF6 of this embodiment has excellent binding ability and unique fluorescent properties with aromatic dyes, making it an excellent chiral host material for preparing chiral host-achiral guest assembly CPL materials. This embodiment avoids tedious synthetic modifications and also avoids expensive liquid crystal materials. It can be prepared in batches by scaling up equivalent quantities, greatly reducing costs. Furthermore, because the chiral cyclophane molecule BinapoBox·4PF6 of this embodiment uses non-covalent bonds to induce guest chirality, guest replacement is less difficult. It can be washed with organic solvents and replaced with different guest molecules for recycling. It is also suitable for most aromatic small molecule dyes, making it a recyclable and versatile new chiral cyclophane product.

[0062] 3. The chiral cyclophane molecule BinapoBox·4PF6 in this embodiment is an organic small molecule. The raw materials for its preparation are easily available and the preparation cost is low. Compared with inorganic nanomaterials, organic synthesis modification, liquid crystal doping, etc., the preparation cost of chiral optically active materials can be greatly reduced.

[0063] 4. The chiral cyclophane molecule BinapoBox·4PF6 in this embodiment has a box-like structure, which enables it to spatially identify aromatic hydrocarbons. That is, the chiral cyclophane molecule can be combined with aromatic hydrocarbons to form cyclophane-aromatic hydrocarbons. The CPL of cyclophane-aromatic hydrocarbons can be compared with the CPL of the chiral cyclophane molecule to achieve qualitative analysis of aromatic hydrocarbon compounds. When the chiral cyclophane molecule BinapoBox·4PF6 combines with different aromatic hydrocarbons, the dihedral angle information of the cyclophane binaphthyl part will change, which will lead to changes in the CPL spectrum, causing g lum The chiral information of each aromatic hydrocarbon on binaphthyl changes differently, which provides a strong accuracy in the qualitative analysis of aromatic hydrocarbons.

[0064] Specific embodiment three: This embodiment differs from specific embodiment two in that: the developing solvents used in the chromatographic purification in step one are petroleum ether and dichloromethane, and the volume ratio of petroleum ether to dichloromethane is 1:1.

[0065] Specific embodiment 4: This embodiment differs from specific embodiment 2 in that: the remaining residue in step 2 is extracted three times with chloroform, and the volume of chloroform used each time is 20-30 mL.

[0066] Specific embodiment five: This embodiment differs from specific embodiment two in that: when the K2CO3 solution is used to wash the extracted product in step 2, 30 to 40 mL of K2CO3 solution is used each time, and the washing is performed three times in total; when the saturated salt water is used to wash the extracted product, 30 to 40 mL of saturated salt water is used each time, and the washing is performed twice in total.

[0067] Specific embodiment 6: This embodiment differs from specific embodiment 2 in that the mass fraction of the K2CO3 solution in step 2 is 10%.

[0068] Specific embodiment seven: This embodiment differs from specific embodiment two in that the concentration of concentrated hydrochloric acid in step five is 12 mol / L.

[0069] Specific embodiment eight: This embodiment differs from specific embodiment two in that: in step five, the precipitate is washed three times with acetone and CH2Cl2 in sequence, using 3-5 mL acetone and 3-5 mL CH2Cl2 acetone and CH2Cl2 respectively each time.

[0070] Specific embodiment 9: The difference between this embodiment and specific embodiment 2 is that the mass fraction of NH4PF6 in the NH4PF6 aqueous solution in step 5 is 5%.

[0071] Specific embodiment 10: In this embodiment, the chiral cyclophane molecule BinapoBox·4PF6 is used to combine with aromatic dyes to prepare CPL active materials. The preparation method is carried out according to the following steps:

[0072] 1. mixing the chiral cyclophane and a solvent to obtain a chiral cyclophane solution;

[0073] The solvent is acetonitrile or methanol;

[0074] The concentration of the chiral cyclophane solution is 1×10 -6 ~1×10 -2 mol / L;

[0075] 2. Dissolve the aromatic dye in the same solvent as in step 1, and then add it to the chiral cyclophane solution prepared in step 1 to complete the preparation of the CPL active material;

[0076] The concentration of the aromatic dye is 0.01-0.1 mol / L;

[0077] The molar ratio of the aromatic dye to the chiral cyclophane is (1-4):1.

[0078] 1. The principle of chiral cyclophane induction using the BinapoBox·4PF6 molecule in this embodiment is that the unique box-shaped structure of the chiral cyclophane molecule can effectively bind to aromatic molecules through π-π interactions. Rotation of the chiral binaphthol unit in the cyclophane transfers axial chirality to the aromatic dye, thereby achieving chiral induction and preparing materials with chiral optical properties.

[0079] 2. The chiral cyclophane molecule BinapoBox·4PF6 of this embodiment has excellent binding ability and unique fluorescent properties with aromatic dyes, making it an excellent chiral host material for preparing chiral host-achiral guest assembly CPL materials. This embodiment avoids tedious synthetic modifications and also avoids expensive liquid crystal materials. It can be prepared in batches by scaling up equivalent quantities, greatly reducing costs. Furthermore, because the chiral cyclophane molecule BinapoBox·4PF6 of this embodiment uses non-covalent bonds to induce guest chirality, guest replacement is less difficult. It can be washed with organic solvents and replaced with different guest molecules for recycling. It is also suitable for most aromatic small molecule dyes, making it a recyclable and versatile new chiral cyclophane product.

[0080] 3. The chiral cyclophane molecule BinapoBox·4PF6 in this embodiment is an organic small molecule. The raw materials for its preparation are easily available and the preparation cost is low. Compared with inorganic nanomaterials, organic synthesis modification, liquid crystal doping, etc., the preparation cost of chiral optically active materials can be greatly reduced.

[0081] 4. The chiral cyclophane molecule BinapoBox·4PF6 in this embodiment has a box-like structure, which enables it to spatially identify aromatic hydrocarbons. That is, the chiral cyclophane molecule can be combined with aromatic hydrocarbons to form cyclophane-aromatic hydrocarbons. The CPL of cyclophane-aromatic hydrocarbons can be compared with the CPL of the chiral cyclophane molecule to achieve qualitative analysis of aromatic hydrocarbon compounds. When the chiral cyclophane molecule BinapoBox·4PF6 combines with different aromatic hydrocarbons, the dihedral angle information of the cyclophane binaphthyl part will change, which will lead to changes in the CPL spectrum, causing g lum The chiral information of each aromatic hydrocarbon on binaphthyl changes differently, which provides a strong accuracy in the qualitative analysis of aromatic hydrocarbons.

[0082] Example 1:

[0083] The structural formula of the chiral cyclophane molecule BinapoBox·4PF6 of the present invention is:

[0084]

[0085] The chiral cyclophane molecule BinapoBox·4PF6 has the general structural formula of C92 H 70 F 24 N4O2P6;

[0086] The preparation method of the chiral cyclophane molecule BinapoBox·4PF6 is carried out according to the following steps:

[0087] Step 1, synthesis of 1,4-bis(bromomethyl)benzene:

[0088] 7.1 g of N-bromosuccinimide and 160 mg of azobisisobutyronitrile were added to 60 mL of p-xylene in acetonitrile; after stirring under reflux for 16 hours, the mixture was evaporated in vacuo and purified by chromatography to obtain 1,4-bis(bromomethyl)benzene as a white powder in an 87% yield;

[0089] The ratio of the mass of xylene to the volume of acetonitrile in the xylene-acetonitrile solution is 2 g:60 mL;

[0090] The developing solvents used in the chromatographic purification are petroleum ether and dichloromethane, and the volume ratio of petroleum ether to dichloromethane is 1:1;

[0091] Step 2: Synthesis of 4,4'-di(pyridin-4-yl)-1,1'-biphenyl:

[0092] 15 mL of dry N,N-dimethylformamide was degassed by bubbling N2 for 2 hours, followed by the addition of 468 mg of 4,4'-dibromo-1,1'-biphenyl, 80 mg of Pd(PPh3)4, 400 mg of 4-pyridineboronic acid, and 2.5 g of Cs2CO3. The mixture was heated to 110°C and maintained for 24 hours to form a suspension. After evaporating the solvent, the remaining residue was extracted with chloroform, and the extracted product was washed with K2CO3 solution and saturated brine in sequence. The washed product was dried over MgSO4, and then the chloroform was removed by evaporation and concentration. 5 mL of dichloromethane was added to dissolve the solid product obtained by evaporation and concentration. 100 mL of n-hexane was added to the obtained solution for precipitation. The obtained solid product was washed with 10 mL of n-hexane and recrystallized with 10 mL of ethyl acetate to obtain 4,4'-di(pyridin-4-yl)-1,1'-biphenyl.

[0093] The remaining residue was extracted with chloroform three times, each time using a volume of 20 mL of chloroform;

[0094] When the K2CO3 solution was used to wash the extracted product, 30 mL of K2CO3 solution was used each time, and the product was washed three times in total. When the saturated saline solution was used to wash the extracted product, 30 mL of saturated saline solution was used each time, and the product was washed twice in total.

[0095] The mass fraction of the K2CO3 solution is 10%;

[0096] Step 3: Synthesis of (R)-4,4-bis-4-pyridyl-1,1'-binaphthyl-2,2'-bisdiphenylphosphine:

[0097] 3.25 g of (R)-4,4-dibromo-1,1'-binaphthyl-2,2'-bisdiphenylphosphine, 0.07 g of Pd(PPh3)4, 1.08 g of 4-pyridineboronic acid, and 2.21 g of K2CO3 were placed in a mixture of 150 mL of 1,4-dioxane and water and heated under reflux for 7 days in a nitrogen atmosphere. The resulting organic phase was washed with 275 mL of H2O. After evaporation of the solvent, the remaining solid was recrystallized from propan-2-ol; the yield was 84%;

[0098] The volume ratio of 1,4-dioxane to water in the mixed solution of 1,4-dioxane and water is 2:1;

[0099] Step 4: Synthesis of bis(4-bromomethylbenzyl)(4,4′-(4,4′-biphenyl)bipyridinium-1-ium)bis(hexafluorophosphate):

[0100] ① In a round-bottom three-necked flask, add 5.14 g of 1,4-bis(bromomethyl)benzene prepared in step 1 to a mixture of 240 mL of CH2Cl2 and acetonitrile, heat and stir in a 50°C oil bath until all the solid matter is dissolved; then increase the oil bath temperature to 90°C to obtain a reaction solution;

[0101] The volume ratio of CH2Cl2 to acetonitrile in the mixture of CH2Cl2 and acetonitrile is 1:1;

[0102] ②. Add 0.6 g of 4,4'-di(pyridin-4-yl)-1,1'-biphenyl prepared in step 2 to 120 mL of acetonitrile, and then titrate into the reaction solution obtained in step ① within 4 hours. After reflux heating for 24 hours, cool to room temperature, filter and collect the yellow precipitate, and wash with CH2Cl2 to obtain a yellow solid; dissolve the yellow solid in 1 L of methanol below room temperature, and then add 400 mg of NH4PF6 and 1 L of H2O below room temperature to obtain bis(4-bromomethylbenzyl)(4,4'-(4,4'-biphenyl)bipyridinium-1-ium)bis(hexafluorophosphate) after precipitation;

[0103] Step 5. Synthesis of chiral cyclophane molecule BinapoBox·4PF6:

[0104] 0.11 g of (R)-4,4-bis-4-pyridyl-1,1'-binaphthyl-2,2'-bisdiphenylphosphine prepared in step 3, 0.35 g of bis(4-bromomethylbenzyl)(4,4'-(4,4'-biphenyl)bipyridinium-1-ium)bis(hexafluorophosphate) prepared in step 4 and 0.027 g of tetrabutylammonium iodide were added to 180 mL of dry acetonitrile and stirred at 80 ° C for 72 h. Then, 3 mL of concentrated hydrochloric acid was added to stop the reaction, and the precipitate was filtered and collected. The precipitate was then washed sequentially with acetone and CH2Cl2 to remove residual tetrabutylammonium iodide. The precipitate was dissolved in 500 mL of 60°C methanol, and an aqueous solution of NH4PF6 was added to obtain a solid product. After the reaction, the precipitate was collected and filtered, and the product was dissolved in 10 mL of acetonitrile to obtain a reaction solution. The reaction solution was placed in an isopropyl ether vapor environment and crystallized three times to complete the reaction. The chiral cyclophane molecule BinapoBox·4PF6 was obtained as a yellow solid with a yield of 37%.

[0105] The concentration of the concentrated hydrochloric acid is 12 mol / L;

[0106] The precipitate was washed three times with acetone and CH2Cl2, using 4 mL of acetone and 4 mL of CH2Cl2, respectively;

[0107] The mass fraction of NH4PF6 in the aqueous solution of NH4PF6 is 5%;

[0108] The method for preparing CPL active materials by combining the chiral cyclophane molecule BinapoBox·4PF6 with aromatic dyes is carried out according to the following steps:

[0109] 1. Mixing a chiral cyclophane and acetonitrile to obtain a chiral cyclophane solution; measuring a CD (circular dichroism) absorption change diagram of the chiral cyclophane solution under 365 nm light excitation; Figure 1 The CD absorption change diagram of cyclophane combined with different equivalents of 4-(perylene-3-yl)pyridine dye guest;

[0110] The concentration of the chiral cyclophane solution is 1×10 -6 mol / L;

[0111] 2. Dissolve the aromatic dye in acetonitrile and add it to the chiral cyclophane solution prepared in step 1 to complete the preparation of the CPL active material. Measure the fluorescence emission changes of the mixed solution under 365nm light excitation; Figure 2 The fluorescence spectrum changes (PL spectrum) of cyclophane combined with different equivalents of 4-(perylene-3-yl)pyridine dye guests;

[0112] The concentration of the aromatic dye is 0.01 mol / L;

[0113] The molar ratio of the aromatic dye to the chiral cyclophane is 1:1;

[0114] Figure 1 The CD absorption change diagram of cyclophane combined with different equivalents of 4-(perylene-3-yl)pyridine dye guest; Figure 2 The fluorescence spectrum change diagram (PL spectrum) of cyclophane combined with different equivalents of 4-(perylene-3-yl)pyridine dye guest. The CD (circular dichroism) absorption change diagram ( Figure 1 ) and the fluorescence emission change diagram obtained in step 2 ( Figure 2 ) were compared comprehensively and it was found that a new absorption signal appeared in the absorption band of the dye, indicating that the achiral dye showed a chiral optical signal; the PL spectrum of the dye was observed through the change of fluorescence emission. The solution of the dye had no PL spectrum at this excitation wavelength, indicating that the cyclopentadienyl host and the dye guest formed a host-guest complex and there was an obvious energy transfer process.

Claims

1. A chiral cyclophane molecule BinapoBox·4PF6, characterized by: The structural formula of the chiral cyclophane molecule BinapoBox·4PF6 is: ； The molecular formula of the chiral cyclophane molecule BinapoBox·4PF6 is C 92 H 70 F 24 N4O2P6.

2. The method for preparing the chiral cyclophane molecule BinapoBox·4PF6 according to claim 1, characterized in that: The preparation method of the chiral cyclophane molecule BinapoBox·4PF6 is carried out according to the following steps: Step 1: Synthesis of 1,4-bis(bromomethyl)benzene: Add 7.1-7.2 g of N-bromosuccinimide and 160-170 mg of azobisisobutyronitrile to 60-70 mL of p-xylene in acetonitrile; after stirring at reflux for 16-17 hours, evaporate the mixture in vacuo and purify it by chromatography to obtain 1,4-bis(bromomethyl)benzene; The ratio of the mass of xylene to the volume of acetonitrile in the xylene-acetonitrile solution is 2-3 g: 60-90 mL; Step 2: Synthesis of 4,4'-di(pyridin-4-yl)-1,1'-biphenyl: 15-20 mL of dry N,N-dimethylformamide was degassed by bubbling N2 for 2 h, followed by the addition of 468-500 mg of 4,4'-dibromo-1,1'-biphenyl, 80-90 mg of Pd(PPh3)4, 400-500 mg of 4-pyridineboronic acid, and 2.5-3.0 g of Cs2CO3, the mixture is heated to 110°C and maintained for 24 hours to form a suspension, the remaining residue after evaporation of the solvent is extracted with chloroform, the extracted product is washed with K2CO3 solution and saturated brine in sequence, the washed product is dried with MgSO4, and then the chloroform is removed by evaporation and concentration, 5-10 mL of dichloromethane is added to dissolve the solid product obtained by evaporation and concentration, 100-120 mL of n-hexane is added to the obtained solution for precipitation, the obtained solid product is washed with 10-20 mL of n-hexane, and after washing, it is recrystallized with 10-20 mL of ethyl acetate to obtain 4,4'-di(pyridin-4-yl)-1,1'-biphenyl; Step 3: Synthesis of (R)-4,4-bis-4-pyridyl-1,1'-binaphthyl-2,2'-bisdiphenylphosphine: 3.25-3.5 g (R)-4,4-dibromo-1,1'-binaphthyl-2,2'-bisdiphenylphosphine, 0.07-0.10 g Pd(PPh3)4, 1.08-1.20 g 4-pyridineboronic acid, and 2.21-2.50 g K2CO3 were placed in a mixture of 150-200 mL 1,4-dioxane and water, and heated under reflux for 7 days in a nitrogen atmosphere. The resulting organic phase was washed with 275-300 mL H2O. After evaporation of the solvent, the remaining solid was recrystallized from propan-2-ol. The volume ratio of 1,4-dioxane to water in the mixed solution of 1,4-dioxane and water is 2:1; Step 4. Synthesis of bis(4-bromomethylbenzyl)(4,4′-(4,4′-biphenyl)bipyridinium-1-ium)bis(hexafluorophosphate): ① In a round-bottom three-necked flask, add 5.14-5.2 g of 1,4-bis(bromomethyl)benzene prepared in step 1 to a mixture of 240 mL of CH2Cl2 and acetonitrile. Heat and stir in a 50°C oil bath until all the solid matter is dissolved. Then, increase the oil bath temperature to 90°C to obtain a reaction solution. The volume ratio of CH2Cl2 to acetonitrile in the mixture of CH2Cl2 and acetonitrile is 1:1; ②. Add 0.6-0.7 g of 4,4'-di(pyridin-4-yl)-1,1'-biphenyl prepared in step 2 to 120-150 mL of acetonitrile, and then titrate into the reaction solution obtained in step ① within 4 hours. After heating under reflux for 24-30 hours, cool to room temperature, collect the yellow precipitate by filtration, and wash with CH2Cl2 to obtain a yellow solid; dissolve the yellow solid in 1-1.5 L of methanol below room temperature, and then add 400-500 mg of NH4PF6 and 1 L of H2O below room temperature to obtain bis(4-bromomethylbenzyl)(4,4'-(4,4'-biphenyl)bipyridin-1-ium)bis(hexafluorophosphate) after precipitation; Step 5. Synthesis of chiral cyclophane molecule BinapoBox·4PF6: 0.11-0.12 g of (R)-4,4-bis-4-pyridyl-1,1'-binaphthyl-2,2'-bisdiphenylphosphine prepared in step 3, 0.35-0.40 g of bis(4-bromomethylbenzyl)(4,4'-(4,4'-biphenyl)bipyridinium-1-ium)bis(hexafluorophosphate) prepared in step 4 and 0.027-0.030 g of tetrabutylammonium iodide were added to 180-200 mL of dry acetonitrile and stirred at 80-90 °C for 72-80 min. The reaction mixture was stirred for 80 h, and then 3 mL of concentrated hydrochloric acid was added to stop the reaction. The precipitate was filtered and collected. The precipitate was then washed with acetone and CH2Cl2 in sequence to remove residual tetrabutylammonium iodide. The precipitate was dissolved in 500-600 mL of 60°C methanol, and an aqueous solution of NH4PF6 was added to obtain a solid product. After the reaction, the precipitate was collected and filtered, and the product was dissolved in 10 mL of acetonitrile to obtain a reaction solution. The reaction solution was placed in an isopropyl ether vapor environment for 2-3 crystallizations to complete the reaction.

3. The method for preparing the chiral cyclophane molecule BinapoBox·4PF6 according to claim 2, characterized in that: The developing solvents used in the chromatographic purification in step 1 are petroleum ether and dichloromethane, and the volume ratio of petroleum ether to dichloromethane is 1:

1.

4. The method for preparing the chiral cyclophane molecule BinapoBox·4PF6 according to claim 2, characterized in that: The remaining residue in step 2 was extracted with chloroform three times, with the volume of chloroform used each time being 20-30 mL.

5. The method for preparing the chiral cyclophane molecule BinapoBox·4PF6 according to claim 2, characterized in that: When the product obtained by extraction is washed with K2CO3 solution as described in step 2, 30-40 mL of K2CO3 solution is used each time, and the washing is performed 3 times in total; When using saturated saline to wash the extracted product, use 30-40 mL of saturated saline each time, and wash twice in total.

6. The method for preparing the chiral cyclophane molecule BinapoBox·4PF6 according to claim 2, characterized in that: The mass fraction of the K2CO3 solution in step 2 is 10%.

7. The method for preparing the chiral cyclophane molecule BinapoBox·4PF6 according to claim 2, characterized in that: The concentration of the concentrated hydrochloric acid in step 5 is 12 mol / L.

8. The method for preparing the chiral cyclophane molecule BinapoBox·4PF6 according to claim 2, characterized in that: Wash the precipitate three times with acetone and CH2Cl2 as described in step 5, using 3-5 mL acetone and 3-5 mL CH2Cl2 respectively each time.

9. The method for preparing the chiral cyclophane molecule BinapoBox·4PF6 according to claim 2, characterized in that: The mass fraction of NH4PF6 in the aqueous solution of NH4PF6 in step 5 is 5%.

10. The use of the chiral cyclophane molecule BinapoBox·4PF6 according to claim 1, characterized in that: The chiral cyclophane molecule BinapoBox·4PF6 is used to combine with aromatic dyes to prepare CPL active materials. The preparation method is carried out according to the following steps:

1. mixing the chiral cyclophane and a solvent to obtain a chiral cyclophane solution; The solvent is acetonitrile or methanol; The concentration of the chiral cyclophane solution is 1×10 -6 ~1×10 -2 mol / L; 2. Dissolve the aromatic dye in the same solvent as in step 1, and then add it to the chiral cyclophane solution prepared in step 1 to complete the preparation of the CPL active material; The concentration of the aromatic dye is 0.01-0.1 mol / L; The molar ratio of the aromatic dye to the chiral cyclophane is (1-4):1.

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