Liquid crystal material based on cation-pi interaction construction and preparation method and application thereof

Abstract

The application relates to a liquid crystal material constructed based on cation-pi interaction and a preparation method and application thereof, first, a styrylpyridine carrying an alkyl tail chain is synthesized, and a corresponding styrylpyridine salt is obtained through a simple methylation reaction, then the cation-pi interaction between the head-to-tail alternating benzene rings and the pyridine salt cations is used to orderly assemble columnar liquid crystal materials. The double cation-pi interaction between adjacent liquid crystal molecules effectively enhances the orderly assembly capacity between the liquid crystal units, thereby widening the temperature interval of the liquid crystal material and improving the stability of the liquid crystal material. The preparation method of the supramolecular liquid crystal material based on the cation-pi interaction not only widens the force category of the supramolecular liquid crystal material, but also provides a new strategy for the preparation of the supramolecular liquid crystal material; in addition, the prepared liquid crystal material based on the cation-pi interaction has great application prospects in the fields of information storage, photoelectric materials and the like due to the high molecular order.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of liquid crystal materials, and relates to a liquid crystal material constructed based on cation-pi interaction and a preparation method and application thereof. BACKGROUND

[0002] Liquid crystals, as a kind of functional soft material with molecular order and liquid flowability, have wide application prospects in the fields of information, energy, environment and separation. Among them, ordered liquid crystal materials assembled by supramolecular means can effectively avoid the cumbersome synthesis and purification steps of traditional covalent liquid crystal materials, thereby further expanding the research scope of liquid crystals. In addition, the dynamic reversible characteristics of non-covalent bonds also endow supramolecular liquid crystal materials with novel functions such as structure controllability and stimulus responsiveness. Therefore, it is of great scientific significance to develop new supramolecular interactions to construct liquid crystal materials.

[0003] Document 1 "Beatriz Feringan, Pilar Romero, Jose Luis Serrano, Cesar L. Folcia, Jesus Etxebarria, Josu Ortega, Roberto Termine, Attilio Golemme, Raquel Gimenez, Teresa Sierra. H-Bonded Donor-Acceptor Units Segregated in Coaxial Columnar Assemblies: Toward High Mobility Ambipolar Organic Semiconductors. Journal of the American Chemical Society, 2016, 138, 12511-12518." discloses a columnar liquid crystal material constructed by hydrogen bond interaction, which realizes the ambipolar transport function of electrons and holes. However, this construction method usually needs to introduce specific hydrogen bond interaction groups, thereby limiting the diversity design of liquid crystal molecules, and the additional hydrogen bond interaction groups may interfere with the ordered arrangement of liquid crystal molecules, which will be detrimental to the stability of supramolecular liquid crystals and the expression and optimization of their functions.

[0004] Document 2 "Yi-Xiong Hu, Xingtian Hao, Lin Xu, Xiaolin Xie, Bijin Xiong, Zhubin Hu, Haitao Sun, Guang-Qiang Yin, Xiaopeng Li, Haiyan Peng, Hai-Bo Yang. Construction of Supramolecular Liquid-Crystalline Metallacycles for Holographic Storage of Colored Images. Journal of the American Chemical Society, 2020, 142, 6285-6294." discloses a strategy for constructing supramolecular liquid crystal materials using coordination-driven self-assembly, and realizes its application in the field of holographic storage by applying external light stimulation, but this construction method also relies on the introduction of some specific metal coordination functional groups, thereby interfering with the highly ordered arrangement of liquid crystal molecules, and the order of liquid crystal molecule assembly directly determines the stability and final optoelectronic function of the material; SUMMARY

[0005] Technical problems to be solved

[0006] In order to avoid the shortcomings of the prior art, the present application proposes a liquid crystal material constructed based on cation-π interaction and a preparation method and application thereof. The preparation method of the supramolecular liquid crystal material constructed by head-to-tail alternating cation-π interaction between styrylpyridine salts further widens the scope of action of the supramolecular liquid crystal material and provides a new strategy for the preparation of the supramolecular liquid crystal material.

[0007] Technical scheme

[0008] A liquid crystal material constructed based on cation-π interaction, characterized in that a one-dimensional supramolecular column is formed by head-to-tail alternating double cation-π interaction between liquid crystal units, and an ordered arrangement forms a two-dimensional columnar liquid crystal structure. The liquid crystal material is (E)-1-methyl-4-(3,4,5-trialkoxy styryl) pyridine-1-chloride, and its structural formula is:

[0009]

[0010] A preparation method of a liquid crystal material constructed based on cation-π interaction, characterized in that the steps are as follows:

[0011] Step 1: 3,4,5-trihydroxybenzaldehyde, 1-bromoalkane, tetrabutylammonium iodide and potassium carbonate were dissolved in N,N-dimethylformamide in a molar ratio of 1:4:0.03:8, and the reaction was stirred; after the reaction solution was cooled to room temperature, the reaction was quenched with water, followed by extraction with dichloromethane, and then purified by column chromatography to obtain white solid 3,4,5-trialkoxybenzaldehyde;

[0012] Step 2: 3,4,5-trialkoxybenzaldehyde, 4-methylpyridine, potassium tert-butoxide were dissolved in N,N-dimethylformamide in a molar ratio of 1:1:1.5, and the reaction was stirred; after the reaction solution was cooled to room temperature, the reaction was quenched with water, followed by extraction with dichloromethane, and then dried over anhydrous magnesium sulfate and rotary evaporated to remove the solvent, and then purified by column chromatography to obtain white solid (E)-4-(3,4,5-trialkoxyphenylstyryl)pyridine;

[0013] Step 3: (E)-4-(3,4,5-trialkoxyphenylstyryl)pyridine and iodomethane were dissolved in acetonitrile in a molar ratio of 1:5, and the reaction was stirred; after the reaction solution was cooled to room temperature, the precipitated solid was collected by suction filtration and washed with acetonitrile several times, and then dried to obtain red solid (E)-1-methyl-4-(3,4,5-trialkoxyphenylstyryl)pyridine-1-iodide;

[0014] Step 4: (E)-1-methyl-4-(3,4,5-trialkoxyphenylstyryl)pyridine-1-iodide and ammonium hexafluorophosphate were dissolved in anhydrous methanol in a molar ratio of 1:2, respectively, and the methanolic solution of ammonium hexafluorophosphate was slowly added to the methanolic solution of the above iodide, and the reaction was stirred at room temperature; after the reaction was completed, the precipitated solid was collected by suction filtration and washed with methanol several times, and then dried to obtain yellow solid (E)-1-methyl-4-(3,4,5-trialkoxyphenylstyryl)pyridine-1-hexafluorophosphate;

[0015] Step 5: (E)-1-methyl-4-(3,4,5-trialkoxyphenylstyryl)pyridine-1-iodide and ammonium tetrafluoroborate were dissolved in anhydrous methanol in a molar ratio of 1:2, respectively, and the methanolic solution of ammonium tetrafluoroborate was slowly added to the methanolic solution of the above iodide, and the reaction was stirred at room temperature; after the reaction was completed, the precipitated solid was collected by suction filtration and washed with methanol several times, and then dried to obtain yellow solid (E)-1-methyl-4-(3,4,5-trialkoxyphenylstyryl)pyridine-1-tetrafluoroborate;

[0016] Step 6: (E)-1-methyl-4-(3,4,5-trialkoxy styryl) pyridine-1-hexafluorophosphate and tetrabutyl ammonium bromide with a molar ratio of 1:2 were dissolved in acetonitrile respectively, the acetonitrile solution of tetrabutyl ammonium bromide was slowly added into the acetonitrile solution of the above hexafluorophosphate, and the reaction was stirred at room temperature; after the reaction was completed, the solid precipitate was extracted by suction filtration and washed with acetonitrile for multiple times, and then dried to obtain a yellow solid (E)-1-methyl-4-(3,4,5-trialkoxy styryl) pyridine-1-bromide;

[0017] Step 7: (E)-1-methyl-4-(3,4,5-trialkoxy styryl) pyridine-1-hexafluorophosphate and tetrabutyl ammonium chloride with a molar ratio of 1:2 were dissolved in acetonitrile respectively, the acetonitrile solution of tetrabutyl ammonium chloride was slowly added into the acetonitrile solution of the above hexafluorophosphate, and the reaction was stirred at room temperature; after the reaction was completed, the solid precipitate was extracted by suction filtration and washed with acetonitrile for 3 times, and then dried to obtain a yellow solid (E)-1-methyl-4-(3,4,5-trialkoxy styryl) pyridine-1-chloride, which is a liquid crystal material constructed based on cation-π interaction.

[0018] The stirring reaction temperature of steps 1, 2 and 3 is 80-85℃, and the stirring reaction time is more than 12 hours.

[0019] The acetonitrile washing times of steps 3, 6 and 7 are 3-4 times.

[0020] The stirring reaction time of steps 4, 5, 6 and 7 at room temperature is 5-6 hours.

[0021] The methanol washing times of steps 4 and 5 are 3 times.

[0022] The anhydrous methanol is a solvent dried by 5A molecular sieves.

[0023] The stirring reaction temperature of steps 1, 2 and 3 is heated under constant temperature oil bath condition.

[0024] The stirring reaction at room temperature is carried out under constant temperature 25℃ oil bath condition.

[0025] The application of the liquid crystal material constructed based on cation-π interaction prepared by the method has high molecular order, and has great application in the fields of information storage and optoelectronic materials.

[0026] Advantages

[0027] This invention proposes a liquid crystal material constructed based on cation-π interactions, its preparation method, and its applications. One-dimensional supramolecular pillars are formed through alternating head-to-tail double cation-π interactions between liquid crystal molecules, which are then further arranged in an ordered manner to form a two-dimensional columnar liquid crystal structure. First, styrylpyridine carrying an alkyl tail chain is synthesized, and the corresponding styrylpyridine salt is obtained through a simple methylation reaction. Then, columnar liquid crystal materials are formed through the ordered assembly of alternating head-to-tail benzene rings and pyridine salt cations via cation-π interactions. The double cation-π interactions between adjacent liquid crystal molecules effectively enhance the ordered assembly ability between liquid crystal molecules, thereby widening the temperature range and improving the stability of the liquid crystal material. This method for preparing supramolecular liquid crystal materials based on cation-π interactions not only broadens the range of interaction forces in supramolecular liquid crystal materials but also provides a new strategy for their preparation. Furthermore, the prepared liquid crystal material based on cation-π interactions has great application potential in fields such as information storage and optoelectronic materials due to its high molecular order. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the molecular structure of the liquid crystal material prepared by the method of this invention.

[0029] Figure 2 This is a representative 1H NMR spectrum of the liquid crystal molecules prepared by the method of this invention.

[0030] Figure 3 This is a representative X-ray scattering image of the liquid crystal material prepared in Example 1 of the present invention.

[0031] Figure 4 The liquid crystal texture of the liquid crystal material prepared in Example 2 of the present invention under a polarizing microscope. Detailed Implementation

[0032] The present invention will now be further described in conjunction with the embodiments and accompanying drawings:

[0033] This invention proposes a method for constructing supramolecular liquid crystal materials through alternating head-to-tail cation-π interactions between styrylpyridinium salts, further broadening the scope of interaction forces in supramolecular liquid crystal materials and providing a new strategy for their preparation.

[0034] A liquid crystal material constructed based on cation-π interactions, characterized in that the structural formula of the liquid crystal molecules is:

[0035]

[0036] A method for preparing a liquid crystal material constructed by cation-π interaction, characterized by the following steps:

[0037] Step 1: 3,4,5-trihydroxybenzaldehyde, 1-bromoalkane, tetrabutylammonium iodide and potassium carbonate were dissolved in N,N-dimethylformamide at a molar ratio of 1:4:0.03:8, and stirred at 80-85°C overnight; after the reaction solution was cooled to room temperature, the reaction was quenched with water, followed by extraction with dichloromethane, and then purified by column chromatography to obtain white solid 3,4,5-trialkoxybenzaldehyde;

[0038] Step 2: 3,4,5-trialkoxybenzaldehyde, 4-methylpyridine and potassium tert-butoxide were dissolved in N,N-dimethylformamide at a molar ratio of 1:1:1.5, and stirred at 80-85°C overnight; after the reaction solution was cooled to room temperature, the reaction was quenched with water, followed by extraction with dichloromethane, and then dried over anhydrous magnesium sulfate and rotary evaporated to remove the solvent, and then purified by column chromatography to obtain white solid (E)-4-(3,4,5-trialkoxyphenylstyryl)pyridine;

[0039] Step 3: (E)-4-(3,4,5-trialkoxyphenylstyryl)pyridine and iodomethane were dissolved in acetonitrile at a molar ratio of 1:5, and stirred at 85-90°C overnight; after the reaction solution was cooled to room temperature, the precipitated solid was collected by suction filtration and washed with acetonitrile for 3-4 times, and then dried to obtain red solid (E)-1-methyl-4-(3,4,5-trialkoxyphenylstyryl)pyridine-1-iodide;

[0040] Step 4: (E)-1-methyl-4-(3,4,5-trialkoxyphenylstyryl)pyridine-1-iodide and ammonium hexafluorophosphate were dissolved in anhydrous methanol at a molar ratio of 1:2, respectively, and the methanolic solution of ammonium hexafluorophosphate was slowly added to the methanolic solution of the above iodide, and stirred at room temperature for 5-6h; after the reaction was completed, the precipitated solid was collected by suction filtration and washed with methanol for 3 times, and then dried to obtain yellow solid (E)-1-methyl-4-(3,4,5-trialkoxyphenylstyryl)pyridine-1-hexafluorophosphate;

[0041] Step 5: (E)-1-methyl-4-(3,4,5-trialkoxyphenylstyryl)pyridine-1-iodide and ammonium tetrafluoroborate were dissolved in anhydrous methanol at a molar ratio of 1:2, respectively, and the methanolic solution of ammonium tetrafluoroborate was slowly added to the methanolic solution of the above iodide, and stirred at room temperature for 5-6h; after the reaction was completed, the precipitated solid was collected by suction filtration and washed with methanol for 3 times, and then dried to obtain yellow solid (E)-1-methyl-4-(3,4,5-trialkoxyphenylstyryl)pyridine-1-tetrafluoroborate;

[0042] Step 6: (E)-1-methyl-4-(3,4,5-trialkoxyphenylvinyl)pyridine-1- hexafluorophosphate and tetrabutylammonium bromide were dissolved in acetonitrile at a molar ratio of 1:2, and the acetonitrile solution of tetrabutylammonium bromide was slowly added dropwise into the acetonitrile solution of the above hexafluorophosphate, and stirred at room temperature for 5-6 h; after the reaction was completed, the solid precipitate was separated by suction filtration, and washed with acetonitrile for 3 times, and dried to obtain a yellow solid (E)-1-methyl-4-(3,4,5-trialkoxyphenylvinyl)pyridine-1-bromide;

[0043] Step 7: (E)-1-methyl-4-(3,4,5-trialkoxyphenylvinyl)pyridine-1- hexafluorophosphate and tetrabutylammonium chloride were dissolved in acetonitrile at a molar ratio of 1:2, and the acetonitrile solution of tetrabutylammonium chloride was slowly added dropwise into the acetonitrile solution of the above hexafluorophosphate, and stirred at room temperature for 5-6 h; after the reaction was completed, the solid precipitate was separated by suction filtration, and washed with acetonitrile for 3 times, and dried to obtain a yellow solid (E)-1-methyl-4-(3,4,5-trialkoxyphenylvinyl)pyridine-1-bromide; Specific embodiments:

[0045] Example 1:

[0046] 2 g of 3,4,5-trihydroxybenzaldehyde, 8.58 g of 1-bromodecane, 400 mg of tetrabutylammonium iodide, and 7.28 g of potassium carbonate were dissolved in 50 mL of N,N-dimethylformamide, and stirred at a constant temperature of 80°C overnight; after the reaction solution was cooled to room temperature, 100 mL of water was added, followed by extraction with 50 mL x 2 times of dichloromethane, and then purified by column chromatography (eluent: n-hexane: ethyl acetate = 50:1) to obtain a white solid 3,4,5-tri(decyloxy)benzaldehyde;

[0047] 5.6 g of 3,4,5-tri(dodecyloxy)benzaldehyde, 1 g of 4-methylpyridine, and 1.4 g of potassium tert-butoxide were dissolved in 100 mL of N,N-dimethylformamide, and stirred at a constant temperature of 80°C overnight; after the reaction solution was cooled to room temperature, 100 mL of water was added to quench the reaction, followed by extraction with 50 mL x 3 times of dichloromethane, and then dried over anhydrous magnesium sulfate and rotary evaporated to remove the solvent, and then purified by column chromatography (eluent: n-hexane: ethyl acetate = 30:1) to obtain a white solid (E)-4-(3,4,5-tri(dodecyloxy)phenylvinyl)pyridine;

[0048] Dissolve 4.2 g of (E)-4-(3,4,5-tri(decyloxy)styryl)pyridine and 1 g of methyl iodide in 50 mL of acetonitrile, and reflux the mixture at 90°C for 12 hours. After the reaction solution is cooled to room temperature, collect the precipitated solid by suction filtration, and wash the solid with 20 mL of acetonitrile for 3 times. Dry the solid to obtain a red solid of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-iodide.

[0049] Dissolve 2 g of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-iodide and 1 g of ammonium hexafluorophosphate in 20 mL of anhydrous methanol, respectively. Slowly add the methanol solution of ammonium hexafluorophosphate into the methanol solution of the above iodide, and stir the mixture at room temperature for 5 hours. After the reaction is completed, collect the precipitated solid by suction filtration, and wash the solid with 20 mL of methanol for 3 times. Dry the solid to obtain a yellow solid of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-hexafluorophosphate.

[0050] Dissolve 2 g of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-iodide and 1 g of ammonium tetrafluoroborate in 20 mL of anhydrous methanol, respectively. Slowly add the methanol solution of ammonium tetrafluoroborate into the methanol solution of the above iodide, and stir the mixture at room temperature for 5 hours. After the reaction is completed, collect the precipitated solid by suction filtration, and wash the solid with 20 mL of methanol for 3 times. Dry the solid to obtain a yellow solid of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-tetrafluoroborate.

[0051] Dissolve 1.5 g of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-hexafluorophosphate and 1 g of tetrabutylammonium bromide in 20 mL of acetonitrile, respectively. Slowly add the acetonitrile solution of tetrabutylammonium bromide into the acetonitrile solution of the above hexafluorophosphate, and stir the mixture at room temperature for 5 hours. After the reaction is completed, collect the precipitated solid by suction filtration, and wash the solid with 20 mL of acetonitrile for 3 times. Dry the solid to obtain a yellow solid of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-bromide.

[0052] Dissolve 1 g of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-hexafluorophosphate and 500 mg of tetrahexylammonium chloride in 20 mL of acetonitrile, respectively. Slowly add the acetonitrile solution of tetrahexylammonium chloride into the acetonitrile solution of the above hexafluorophosphate, and stir the mixture at room temperature for 5 hours. After the reaction is completed, collect the precipitated solid by suction filtration, and wash the solid with 20 mL of acetonitrile for 3 times. Dry the solid to obtain a yellow solid of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-chloride.

[0053] From the above, it can be seen that the compounds of the present application have the following advantages: Figure 2The nuclear magnetic resonance hydrogen spectrum of the liquid crystal molecule prepared in Embodiment 1 can be seen to have been successfully synthesized;

[0054] From Figure 3 The X-ray scattering diagram of the liquid crystal material prepared in Embodiment 1 can be seen to exhibit an ordered hexagonal columnar liquid crystal phase structure;

[0055] From Figure 4 The texture under a polarizing microscope can be seen to exhibit a typical columnar liquid crystal phase texture of the liquid crystal material prepared in Embodiment 2.

[0056] Embodiment Two:

[0057] 3.2g of 3,4,5-trihydroxybenzaldehyde, 13.73g of 1-bromodecane, 640mg of tetrabutylammonium iodide, 11.6g of potassium carbonate were dissolved in 80mL of N,N-dimethylformamide, and the reaction was stirred at a constant temperature of 80°C overnight; after the reaction liquid was cooled to room temperature, 120mL of water was added, followed by extraction with dichloromethane 80mL x 2 times, and then column chromatography was used for separation and purification (the eluent was n-hexane: ethyl acetate = 50:1), to obtain white solid 3,4,5-tri(decyloxy)benzaldehyde;

[0058] 8.96g of 3,4,5-tri(dodecyloxy)benzaldehyde, 1.6g of 4-methylpyridine, 2.24g of potassium tert-butoxide were dissolved in 120mL of N,N-dimethylformamide, and the reaction was stirred at a constant temperature of 80°C overnight; after the reaction liquid was cooled to room temperature, 120mL of water was added to quench the reaction, followed by extraction with dichloromethane 80mL x 3 times, and then dried over anhydrous magnesium sulfate, and then rotary evaporation was used to remove the solvent, and then column chromatography was used for separation and purification (the eluent was n-hexane: ethyl acetate = 30:1), to obtain white solid (E)-4-(3,4,5-tri(decyloxy)styryl)pyridine;

[0059] 6.72g of (E)-4-(3,4,5-tri(decyloxy)styryl)pyridine, 1.6g of iodomethane were dissolved in 80mL of acetonitrile, and the reaction was stirred at a constant temperature of 90°C under reflux overnight; after the reaction liquid was cooled to room temperature, the solid precipitate that separated out was collected by suction filtration, and washed with 35mL of acetonitrile 3 times, and then dried to obtain red solid (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-iodide;

[0060] Dissolve 3.2 g of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1- iodide and 1.8 g of ammonium hexafluorophosphate in 60 mL of anhydrous methanol, respectively, slowly drop the methanol solution of ammonium hexafluorophosphate into the methanol solution of the above iodide, stir at room temperature for 5 h; after the reaction is completed, the solid precipitate is separated by suction filtration, and washed with 40 mL of methanol for 3 times, and dried to obtain a yellow solid of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1- hexafluorophosphate;

[0061] Dissolve 3.1 g of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1- iodide and 1.5 g of ammonium tetrafluoroborate in 60 mL of anhydrous methanol, respectively, slowly drop the methanol solution of ammonium tetrafluoroborate into the methanol solution of the above iodide, stir at room temperature for 5 h; after the reaction is completed, the solid precipitate is separated by suction filtration, and washed with 40 mL of methanol for 3 times, and dried to obtain a yellow solid of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1- tetrafluoroborate;

[0062] Dissolve 2.4 g of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1- hexafluorophosphate and 1.7 g of tetrabutylammonium bromide in 50 mL of acetonitrile, respectively, slowly drop the acetonitrile solution of tetrabutylammonium bromide into the acetonitrile solution of the above hexafluorophosphate, stir at room temperature for 5 h; after the reaction is completed, the solid precipitate is separated by suction filtration, and washed with 40 mL of acetonitrile for 3 times, and dried to obtain a yellow solid of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1- bromide;

[0063] Dissolve 1.6 g of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1- hexafluorophosphate and 800 mg of tetrahexylammonium chloride in 50 mL of acetonitrile, respectively, slowly drop the acetonitrile solution of tetrahexylammonium chloride into the acetonitrile solution of the above hexafluorophosphate, stir at room temperature for 5 h; after the reaction is completed, the solid precipitate is separated by suction filtration, and washed with 40 mL of acetonitrile for 3 times, and dried to obtain a yellow solid of (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1- chloride;

[0064] Example Three:

[0065] 3.66g 3,4,5-trihydroxybenzaldehyde, 15.7g 1-bromodecane, 732mg tetrabutylammonium iodide, 13.3g potassium carbonate were dissolved in 100mL of N,N-dimethylformamide, constant temperature 80℃ stirring overnight; after the reaction liquid cooled to room temperature, add 150mL water, then extracted with dichloromethane 100mL x 2 times, and then purified by column chromatography (eluent is n-hexane: ethyl acetate = 50:1) to obtain white solid 3,4,5-tris (decyloxy) benzaldehyde;

[0066] 10.3g 3,4,5-tris (dodecyloxy) benzaldehyde, 1.85g 4-methylpyridine, 2.56g potassium tert-butoxide were dissolved in 150mL of N,N-dimethylformamide, constant temperature 80℃ stirring overnight; after the reaction liquid cooled to room temperature, add 200mL water to quench the reaction, then extracted with dichloromethane 150mL x 3 times, and then dried over anhydrous magnesium sulfate and rotary evaporation to remove the solvent, and then purified by column chromatography (eluent is n-hexane: ethyl acetate = 30:1) to obtain white solid (E)-4-(3,4,5-tris (decyloxy) styryl) pyridine;

[0067] 7.68g (E)-4-(3,4,5-tris (decyloxy) styryl) pyridine, 2g iodomethane were dissolved in 100mL of acetonitrile, constant temperature 90℃ stirring reflux reaction overnight, after the reaction liquid cooled to room temperature, the collected solid precipitate was washed with 80mL of acetonitrile 3 times, and then dried to obtain red solid (E)-1-methyl-4-(3,4,5-tris (decyloxy) styryl) pyridine-1-iodide;

[0068] 3.66g (E)-1-methyl-4-(3,4,5-tris (decyloxy) styryl) pyridine-1-iodide, 2.1g ammonium hexafluorophosphate were dissolved in 70mL of anhydrous methanol, the ammonium hexafluorophosphate methanol solution was slowly added to the iodide methanol solution, and stirred at room temperature for 5h; after the reaction was completed, the solid precipitate was collected by suction filtration and washed with 60mL of methanol 3 times, and then dried to obtain yellow solid (E)-1-methyl-4-(3,4,5-tris (decyloxy) styryl) pyridine-1-hexafluorophosphate;

[0069] 3.8g (E)-1-methyl-4-(3,4,5-tris (decyloxy) styryl) pyridine-1-iodide, 2.3g ammonium tetrafluoroborate were dissolved in 80mL of anhydrous methanol, the ammonium tetrafluoroborate methanol solution was slowly added to the iodide methanol solution, and stirred at room temperature for 5h; after the reaction was completed, the solid precipitate was collected by suction filtration and washed with 50mL of methanol 3 times, and then dried to obtain yellow solid (E)-1-methyl-4-(3,4,5-tris (decyloxy) styryl) pyridine-1-tetrafluoroborate;

[0070] 2.7g (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-hexafluorophosphate, 2.2g tetrabutylammonium bromide were dissolved in 70mL acetonitrile respectively, the acetonitrile solution of tetrabutylammonium bromide was slowly added to the hexafluorophosphate acetonitrile solution, stirred at room temperature for 5h; after the reaction was completed, the solid precipitate was extracted by suction filtration, and washed with 60mL acetonitrile for 3 times, and dried to obtain a yellow solid (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-bromide;

[0071] 1.9g (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-hexafluorophosphate, 1.3g tetrahexylammonium chloride were dissolved in 75mL acetonitrile respectively, the acetonitrile solution of tetrahexylammonium chloride was slowly added to the hexafluorophosphate acetonitrile solution, stirred at room temperature for 5h; after the reaction was completed, the solid precipitate was extracted by suction filtration, and washed with 60mL acetonitrile for 3 times, and dried to obtain a yellow solid (E)-1-methyl-4-(3,4,5-tri(decyloxy)styryl)pyridine-1-chloride.

[0072] The liquid crystal material based on cation-π interaction constructed by the application has high molecular order, and has great application in the fields including but not limited to information storage, optoelectronic materials and the like.

Claims

1. A liquid crystal material based on cation-π interactions, characterized in that The one-dimensional supramolecular column is formed by the head-to-tail alternation of the double cation-π interaction between liquid crystal units, and the two-dimensional columnar liquid crystal structure is formed by the ordered arrangement of (E)-1-methyl-4-(3, 4, 5-trialkoxy styryl) pyridine salt, and the structural formula is as follows: 。 2. A method for preparing the liquid crystal material based on cation-π interaction according to claim 1, characterized in that The steps are as follows: Step 1: 3, 4, 5-trihydroxybenzaldehyde, 1-bromide alkane, tetrabutylammonium iodide and potassium carbonate in a molar ratio of 1:4:0.03:8 are dissolved in N, N-dimethylformamide, and the stirring reaction is carried out; after the reaction solution is cooled to room temperature, the reaction is quenched by adding water, then extracted with dichloromethane, and then separated and purified by column chromatography to obtain white solid 3, 4, 5-trialkoxybenzaldehyde; Step 2: 3, 4, 5-trialkoxybenzaldehyde, 4-methylpyridine and potassium tert-butoxide in a molar ratio of 1:1:1.5 are dissolved in N, N-dimethylformamide, and the stirring reaction is carried out; after the reaction solution is cooled to room temperature, the reaction is quenched by adding water, then extracted with dichloromethane, then dried over anhydrous magnesium sulfate, and then rotary evaporated to remove the solvent, and then separated and purified by column chromatography to obtain white solid (E)-4-(3, 4, 5-trialkoxy styryl) pyridine; Step 3: (E)-4-(3, 4, 5-trialkoxy styryl) pyridine and methyl iodide in a molar ratio of 1:5 are dissolved in acetonitrile, and the stirring reaction is carried out; after the reaction solution is cooled to room temperature, the solid precipitate is collected by suction filtration, washed with acetonitrile for multiple times, and dried to obtain red solid (E)-1-methyl-4-(3, 4, 5-trialkoxy styryl) pyridine-1-iodide; Step 4: (E)-1-methyl-4-(3, 4, 5-trialkoxy styryl) pyridine-1-iodide and ammonium hexafluorophosphate in a molar ratio of 1:2 are respectively dissolved in anhydrous methanol, the methanol solution of ammonium hexafluorophosphate is slowly added to the methanol solution of the above iodide, and the stirring reaction is carried out at room temperature; after the reaction is completed, the solid precipitate is collected by suction filtration and washed with methanol for multiple times, and dried to obtain yellow solid (E)-1-methyl-4-(3, 4, 5-trialkoxy styryl) pyridine-1-hexafluorophosphate; The 1-bromide alkane is 1-bromide decane.

3. The method of claim 2, wherein: The stirring reaction temperature of step 1, step 2 and step 3 is 80-85℃, and the stirring reaction is carried out for more than 12 hours.

4. The method of claim 2, wherein: Step 3 is washed with acetonitrile for 3-4 times.

5. The method of claim 2, wherein: The stirring reaction of step 4 is carried out at room temperature for 5-6 h.

6. The method of claim 2, wherein: The methanol washing of step 4 is carried out for 3 times.

7. The method of claim 2, wherein: The anhydrous methanol is a solvent dried by 5A molecular sieves.

8. The method of claim 2, wherein: The stirring reaction temperature of step 1, step 2 and step 3 is heated under constant temperature oil bath conditions.

9. The method of claim 2, wherein: The stirring reaction at room temperature is carried out under constant temperature 25℃ oil bath conditions.

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