Double-bowl-shaped molecular container based on isoanion induction as well as preparation method and application of double-bowl-shaped molecular container

Abstract

The invention discloses a double-bowl-shaped molecular container based on isoanion induction as well as a preparation method and application of the double-bowl-shaped molecular container, and relates to the technical field of supramolecular materials. The method comprises the following steps: dissolving 1, 2, 3, 4, 5, 6-hexabromomethyl benzene and 9-(2-(1H-imidazole-1-yl) ethyl)-9H-carbazole into acetonitrile, so as to obtain a first intermediate product; dissolving the first intermediate product in methanol, and dropwise adding a saturated ammonium hexafluorophosphate methanol solution while stirring to obtain a second intermediate product; and dissolving the second intermediate product and tetrabutylammonium bromide in acetonitrile, filtering, adding the filtrate into isopropyl ether, sealing, and standing at room temperature for 12-24 hours to obtain the double-bowl-shaped molecular container. Under the common induction of bromide ions and hexafluorophosphate ions, the six arms are alternately folded up and down three times to form the double-bowl-shaped molecular container.

Description

Technical Field

[0001] The present invention relates to the technical field of supramolecular materials, and in particular to a double-bowl-shaped molecular container based on heteroanion induction, a preparation method thereof, and an application thereof. Background Art

[0002] Bowl-shaped molecular containers, due to their unique topological structure and cavities, have been widely used in molecular recognition, catalysis, and adsorption. Therefore, the design and synthesis of bowl-shaped molecular containers, especially those with multiple cavities, is of great significance for enriching their structure and applications.

[0003] The prior art discloses a method for synthesizing a bibowl-shaped molecular container via the coupling of bicyclic dibromoolefins and a multi-step reaction. However, the cumbersome synthesis steps of this method result in a low final yield, limiting the application of bibowl-shaped molecular containers. The prior art also discloses a method for synthesizing a bibowl-shaped cavity via a condensation reaction between triethylamine or tripropylamine and a trialdehyde derivative. Although the bowl-shaped molecular container synthesized by this method has good stability, the fixed size of the cavity limits the molecules that can be recognized. Summary of the Invention

[0004] To address the shortcomings of the aforementioned background technology, the present invention provides a bi-bowl-shaped molecular container based on heteroanion induction, as well as its preparation method and application. This method uses a series of organic synthesis methods to produce a compound containing six flexible arms, wherein the six arms fold into a four-up, two-down configuration. Upon addition of tetrabutylammonium bromide, under the combined induction of bromide ions and hexafluorophosphate ions, the six arms adopt an alternating three-up, three-down folding pattern, forming a bi-bowl-shaped molecular container. This bi-bowl-shaped molecular container has great application prospects in fields such as molecular recognition, catalysis, and adsorption.

[0005] The first object of the present invention is to provide a method for preparing a double-bowl-shaped molecular container based on heteroanion induction, comprising the following steps: Dissolve 1,2,3,4,5,6-hexabromomethylbenzene and 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole in acetonitrile, heat to 90-95° C., stir and reflux for 18-24 hours to obtain a first intermediate product; The first intermediate product was dissolved in methanol, and a saturated methanol solution of ammonium hexafluorophosphate was added dropwise under stirring until no more precipitate was formed. The stirring was continued for 30 to 40 minutes to obtain a second intermediate product. The second intermediate product and tetrabutylammonium bromide are dissolved in acetonitrile. After filtering, the filtrate is added to isopropyl ether, sealed, and left at room temperature for 12 to 24 hours to obtain a double bowl-shaped molecular container.

[0006] Preferably, the molar ratio of 1,2,3,4,5,6-hexabromomethylbenzene to 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole is 1:7-10.

[0007] Preferably, the molar ratio of the second intermediate product to tetrabutylammonium bromide is 1:2-3.

[0008] Preferably, the first intermediate product is 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) bromide; The second intermediate product is 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium)hexafluorophosphate.

[0009] Preferably, after standing at room temperature for 12 to 24 hours, the method further comprises: filtering and washing the filter cake with isopropyl ether; After continuing stirring for 30 to 40 minutes, the process is filtered and the filter cake is washed several times with methanol and water. After refluxing for 18 to 24 hours, the mixture was cooled to room temperature and filtered, and the filter cake was washed several times with acetonitrile and dichloromethane respectively.

[0010] Preferably, the second intermediate product and tetrabutylammonium bromide are dissolved in acetonitrile, and filtered using a 220-micron organic filter head.

[0011] Preferably, the 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole is prepared according to the following steps: Dissolve 2-(9H-carbazol-9-yl)ethanol and triphenylphosphine in acetonitrile, cool in an ice bath for 10-15 minutes, add carbon tetrabromide while stirring, continue stirring and return to room temperature, and react for 12-16 hours. After the reaction is completed, the solvent is removed under reduced pressure, and the concentrate is dissolved in dichloromethane, and then washed multiple times with a saturated sodium chloride aqueous solution and deionized water, respectively. The organic phases are combined, dried over anhydrous sodium sulfate, and the solvent is removed under reduced pressure to obtain a crude product. The crude product is separated by gel chromatography to obtain 9-(2-bromoethyl)-9H-carbazole. Imidazole and potassium hydroxide are uniformly dissolved in N,N-dimethylformamide, and 9-(2-bromoethyl)-9H-carbazole is added. After stirring and reacting at 90-100°C for 12-14 hours, 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole is obtained through purification.

[0012] Preferably, the 2-(9H-carbazol-9-yl)ethanol is prepared according to the following steps: Carbazole and potassium hydroxide are added to N,N-dimethylformamide, stirred and mixed at room temperature, and then 2-bromoethanol is added. Subsequently, oxygen is removed by Schlenk technique. Thereafter, the solution is heated to 90-100°C under nitrogen atmosphere and stirred for 16-24 hours. After post-treatment, 2-(9H-carbazol-9-yl)ethanol is obtained.

[0013] The second object of the present invention is to provide a double-bowl-shaped molecular container based on heteroanion induction.

[0014] The third object of the present invention is to provide an application of a double-bowl-shaped molecular container based on heteroanion induction in molecular recognition, catalysis or adsorption.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a double-bowl-shaped molecular container based on heteroanion induction, as well as its preparation method and application. Through a series of organic synthesis methods, the present invention obtains a compound containing six flexible arms, 3,3',3'',3''',3''',3''''-(phenyl-1,2,3,4,5,6-hexenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate. The six arms fold into a four-up, two-down conformation. Upon addition of tetrabutylammonium bromide, under the combined induction of bromide ions and hexafluorophosphate ions, the six arms adopt an alternating three-up, three-down folding pattern, forming a double-bowl-shaped molecular container. This method is simple to operate, has a high yield, and can achieve gram-scale preparation. In addition, this double-bowl-shaped molecular container has great application prospects in fields such as molecular recognition, catalysis, and adsorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The mass spectrum of 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate is shown; Figure 2 It is a single crystal structure of a double bowl-shaped molecular container; Figure 3 This is the mass spectrum of the double bowl-shaped molecular container; Figure 4 This is a single crystal morphology of a double-bowl-shaped molecular container; Figure 5 To prove by nuclear magnetic titration that the double bowl-shaped molecular container prepared in Example 1 has the ability to recognize fluoride ions; Figure 6To prove by nuclear magnetic titration that the double bowl-shaped molecular container prepared in Example 1 has the ability to recognize chloride ions; Figure 7 The crystal structure of 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) bromide; Figure 8 The crystal structure of 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments and drawings, but the embodiments are not intended to limit the present invention.

[0018] The purpose of the present invention is to provide a double-bowl-shaped molecular container based on heteroanion induction, a preparation method thereof and an application thereof.

[0019] In order to achieve the above object, the first aspect of the present invention provides a method for preparing a double-bowl-shaped molecular container based on heteroanion induction, comprising the following steps: Dissolve 1,2,3,4,5,6-hexabromomethylbenzene and 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole in acetonitrile, heat to 90-95° C., stir and reflux for 18-24 hours to obtain a first intermediate product; The first intermediate product was dissolved in methanol, and a saturated methanol solution of ammonium hexafluorophosphate was added dropwise under stirring until no more precipitate was formed. The stirring was continued for 30 to 40 minutes to obtain a second intermediate product. The second intermediate product and tetrabutylammonium bromide are dissolved in acetonitrile. After filtering, the filtrate is added to isopropyl ether, sealed, and left at room temperature for 12 to 24 hours to obtain a double bowl-shaped molecular container.

[0020] Wherein, the molar ratio of the 1,2,3,4,5,6-hexabromomethylbenzene to 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole is 1:7-10.

[0021] The molar ratio of the second intermediate product to tetrabutylammonium bromide is 1:2-3.

[0022] The first intermediate product is 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) bromide; The second intermediate product is 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium)hexafluorophosphate.

[0023] Specifically, after standing at room temperature for 12 to 24 hours, the method further comprises: filtering and washing the filter cake with isopropyl ether; After continuing stirring for 30 to 40 minutes, the process is filtered and the filter cake is washed several times with methanol and water. After refluxing for 18 to 24 hours, the mixture was cooled to room temperature and filtered, and the filter cake was washed several times with acetonitrile and dichloromethane respectively.

[0024] The second intermediate product and tetrabutylammonium bromide were dissolved in acetonitrile and filtered using a 220-micron organic filter head.

[0025] According to the present invention, the 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole is prepared according to the following steps: Dissolve 2-(9H-carbazol-9-yl)ethanol and triphenylphosphine in acetonitrile, cool in an ice bath for 10-15 minutes, add carbon tetrabromide while stirring, continue stirring and return to room temperature, and react for 12-16 hours. After the reaction is completed, the solvent is removed under reduced pressure, and the concentrate is dissolved in dichloromethane, and then washed multiple times with a saturated sodium chloride aqueous solution and deionized water, respectively. The organic phases are combined, dried over anhydrous sodium sulfate, and the solvent is removed under reduced pressure to obtain a crude product. The crude product is separated by gel chromatography to obtain 9-(2-bromoethyl)-9H-carbazole. Imidazole and potassium hydroxide are uniformly dissolved in N,N-dimethylformamide, and 9-(2-bromoethyl)-9H-carbazole is added. After stirring and reacting at 90-100°C for 12-14 hours, 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole is obtained through purification.

[0026] Wherein, the 2-(9H-carbazol-9-yl)ethanol is prepared according to the following steps: Carbazole and potassium hydroxide are added to N,N-dimethylformamide, stirred and mixed at room temperature, and then 2-bromoethanol is added. Subsequently, oxygen is removed by Schlenk technique. Thereafter, the solution is heated to 90-100°C under nitrogen atmosphere and stirred for 16-24 hours. After post-treatment, 2-(9H-carbazol-9-yl)ethanol is obtained.

[0027] Exemplarily, a method for preparing a double-bowl-shaped molecular container based on heteroanion induction comprises: Step 1: In a single-necked round-bottom flask, carbazole and potassium hydroxide were added in a molar ratio of 1:6, and then anhydrous N,N-dimethylformamide was added as a solvent. After stirring at room temperature for 30 minutes, 1.1 equivalents of 2-bromoethanol were added. The above solution was deoxygenated by Schlenk technique, and then the solution was heated to 90°C under nitrogen atmosphere and stirred for 24 hours. After the reaction was completed, the reaction mixture was filtered while hot, the filtrate was collected and the solvent was removed by vacuum distillation, and then the concentrate was dissolved in an appropriate amount of dichloromethane, washed with saturated brine and deionized water 3 times each, the organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was separated by gel chromatography column, and the eluent was petroleum ether: ethyl acetate = 4:1 to obtain a white solid 2-(9H-carbazole-9-yl)ethanol; The Schlenk technique in step 1 is as follows: after adding the reactants and solvent into a dry Schlenk tube, first freeze it with liquid nitrogen, then evacuate it under a nitrogen atmosphere, then introduce nitrogen, and then freeze it again with liquid nitrogen. This freeze-thaw-freeze operation is repeated many times.

[0028] Step 2: Add 2-(9H-carbazole-9-yl)ethanol and triphenylphosphine in a molar ratio of 1:2 in a single-necked round-bottom flask, add an appropriate amount of acetonitrile, and cool in an ice bath for 30 minutes. Slowly add 3 equivalents of carbon tetrabromide under constant stirring. Stir the mixture and slowly return to room temperature and react for 12 hours. Remove the solvent under reduced pressure, dissolve the concentrate in an appropriate amount of dichloromethane, and then wash it three times with a saturated sodium chloride aqueous solution and an aqueous solution, combine the organic phases, dry them over anhydrous sodium sulfate, and remove the solvent under reduced pressure to obtain a crude product. The crude product was separated by gel chromatography column, and the eluent was petroleum ether: ethyl acetate = 10:1 to obtain a white solid 9-(2-bromoethyl)-9H-carbazole; The ice bath cooling of the solution in step 2 is carried out at 0°C in an ice-water mixture.

[0029] Step 3: Add imidazole and potassium hydroxide in a molar ratio of 1:10 in a single-necked round-bottom flask, then add anhydrous N,N-dimethylformamide as a solvent, stir at room temperature for 30 minutes, and then add 0.5 equivalents of 9-(2-bromoethyl)-9H-carbazole. After continuing to stir the reaction at 100°C for 12 hours, filter while hot, concentrate the collected filtrate by rotary evaporation, then add dichloromethane to dissolve the mixture, and transfer it to a separatory funnel for extraction after it is fully dissolved. Wash it three times with saturated brine and then three times with deionized water. Collect the organic phase, add anhydrous sodium sulfate and dry it for 10 minutes, then remove the solvent from the organic phase by rotary evaporator. The crude product was separated by gel chromatography column, and the eluent was petroleum ether / ethyl acetate / methanol = 4:1:1 to obtain a white solid 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole; Step 4: 1,2,3,4,5,6-hexabromomethylbenzene and 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole obtained in Step 3 were added to a single-necked flask at a molar ratio of 1:7-10. Anhydrous acetonitrile was added as a solvent, and the mixture was heated to 90°C and stirred under reflux for 24 hours. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed three times with acetonitrile and dichloromethane, respectively, and dried to obtain a white solid 3,3',3'',3''',3''',3''''-(benzene-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) bromide. Step 5: Dissolve 3,3',3'',3''',3'''',3''''-(phenyl-1,2,3,4,5,6-hexenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) bromide in an appropriate amount of methanol. Saturated ammonium hexafluorophosphate methanol solution was slowly added dropwise with constant stirring until no more precipitate formed. Stirring was continued for 30 minutes. Filter, and the filter cake was washed three times with methanol and three times with water. After drying, a white solid 3,3',3'',3''',3'''',3''''-(phenyl-1,2,3,4,5,6-hexenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate was obtained. Step 6: 3,3',3'',3''',3''',3''''-(phenyl-1,2,3,4,5,6-hexenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate and tetrabutylammonium bromide are added to a vial at a molar ratio of 1:2-3, and then an appropriate amount of acetonitrile solution is added to fully dissolve the mixture. The mixture is filtered through a 220-micron organic filter head, and the filtrate is placed into a new vial. Finally, the mixture is transferred to a wide-mouth bottle containing an appropriate amount of isopropyl ether, sealed, and placed at room temperature overnight to cultivate a single crystal of a bibowl-shaped molecule. The mixture is filtered, and the filter cake is washed with isopropyl ether to obtain white crystals. The bibowl-shaped molecular container is obtained by drying. The anhydrous N,N-dimethylformamide and anhydrous acetonitrile solvents in step 1, step 3 and step 4 are solvents dried over 5A molecular sieves.

[0030] The solution heating in steps 1 to 4 is carried out in a constant temperature oil bath.

[0031] The synthetic route of the double bowl-shaped molecular container is as follows: .

[0032] The second aspect of the present invention provides a double-bowl-shaped molecular container based on heteroanion induction.

[0033] The third aspect of the present invention provides an application of a double-bowl-shaped molecular container based on heteroanion induction in molecular recognition, catalysis or adsorption.

[0034] It should be noted that the experimental methods used in the present invention are all conventional methods unless otherwise specified; the reagents and materials used are all commercially available unless otherwise specified.

[0035] Example 1 A method for preparing a double-bowl-shaped molecular container based on heteroanion induction, comprising: To a single-necked round-bottom flask, carbazole (8.35 g, 0.05 mol), potassium hydroxide (16.8 g, 0.3 mmol), and 200 ml of anhydrous N,N-dimethylformamide were added sequentially. After stirring at room temperature for 30 minutes, 2-bromoethanol (6.87 g, 0.055 mol) was added. The solution was deoxygenated using a Schlenk technique and then heated to 90°C under a nitrogen atmosphere with stirring for 24 hours. After the reaction, the hot reaction mixture was filtered, the filtrate collected, and the solvent removed by vacuum distillation. The concentrate was dissolved in 200 mL of dichloromethane and washed three times with saturated brine and deionized water (50 mL x 3). The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent removed under reduced pressure to obtain the crude product. The crude product was separated by gel chromatography using a 4:1 ratio of petroleum ether to ethyl acetate as the eluent to afford 2-(9H-carbazol-9-yl)ethanol as a white solid (yield 64%).

[0036] To a single-necked round-bottom flask, 2-(9H-carbazol-9-yl)ethanol (3.37 g, 16.0 mmol) and triphenylphosphine (5.03 g, 19.2 mmol) were added sequentially, followed by 150 mL of anhydrous acetonitrile and ice-cooled for 30 minutes. Carbon tetrabromide (6.37 g, 19.2 mmol) was slowly added with constant stirring. The mixture was stirred and slowly returned to room temperature, and the reaction was continued for 12 hours. The solvent was removed under reduced pressure, and the concentrate was dissolved in 200 mL of dichloromethane and washed three times with saturated sodium chloride solution and then with water (50 mL x 3). The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain the crude product. The crude product was separated by gel chromatography using a 10:1 ratio of petroleum ether to ethyl acetate as the eluent to afford 9-(2-bromoethyl)-9H-carbazole as a white solid (80% yield).

[0037] To a single-necked round-bottom flask, imidazole (0.68 g, 10 mmol) and potassium hydroxide (0.56 g, 10 mmol) were added sequentially, followed by 50 mL of anhydrous N,N-dimethylformamide as the solvent. After stirring at room temperature for 30 minutes, 9-(2-bromoethyl)-9H-carbazole (1.36 g, 5 mmol) was added. The reaction was stirred at 100°C for 12 hours. The mixture was then filtered while hot and concentrated by vacuum distillation. 200 mL of dichloromethane was added to dissolve the mixture. Once fully dissolved, the mixture was transferred to a separatory funnel for extraction. The mixture was washed three times with saturated brine (50 mL x 3) and then three times with deionized water (50 mL x 3). The organic phase was collected, dried over anhydrous sodium sulfate for 10 minutes, and then the solvent was removed by vacuum distillation. The crude product was separated by gel chromatography using petroleum ether / ethyl acetate / methanol = 4:1:1 as eluent to obtain 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole as a white solid (yield 61%).

[0038] 1,2,3,4,5,6-Hexabromomethylbenzene (0.32 g, 0.5 mmol) and 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole (1.04 g, 4 mmol) were added to a one-necked flask. 50 ml of anhydrous acetonitrile was added as the solvent, and the mixture was heated to 90°C with stirring and reflux for 24 hours. After the reaction, the mixture was cooled to room temperature and filtered. The filter cake was washed three times with acetonitrile and three times with dichloromethane. After drying, 3,3',3'',3''',3'''',3''''-(benzene-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) bromide was obtained as a white solid (yield 92%).

[0039] Dissolve 3,3',3'',3''',3''',3''''-(phenyl-1,2,3,4,5,6-hexenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) bromide in an appropriate amount of methanol. Saturated ammonium hexafluorophosphate methanol solution was slowly added dropwise with continuous stirring until no further precipitation occurred. Stirring was continued for 30 minutes. Filter the mixture, wash the filter cake three times with methanol and three times with water, and dry it to obtain 3,3',3'',3''',3'''',3''''-(phenyl-1,2,3,4,5,6-hexenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate as a white solid (yield 95%).

[0040] Among them, the molecular structure of 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate is: .

[0041] See also Figure 1 As shown in the figure, the mass spectrum of 3,3',3'',3''',3'''',3'''''-(benzene-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate further illustrates that the present invention achieves the successful preparation of 3,3',3'',3''',3'''',3'''''-(benzene-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate.

[0042] 3,3',3'',3''',3''',3''''-(phenyl-1,2,3,4,5,6-hexenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate (0.1 g, 0.038 mmol) and tetrabutylammonium bromide (24.5 mg, 0.076 mmol) were added to a vial at a molar ratio of 1:2. 2 mL of anhydrous acetonitrile was then added to fully dissolve the product. The product was filtered through a 220-μm organic filter. The filtrate was transferred to a new vial, sealed with tin foil, and evenly punctured with small holes using a needle. The product was then transferred to a wide-mouth bottle containing an appropriate amount of isopropyl ether, sealed, and allowed to stand at room temperature overnight. The product was filtered, and the filter cake was washed with isopropyl ether. After drying, white crystals of a bibowl-shaped molecular container were obtained.

[0043] See also Figure 2 Figure 2 shows the single crystal structure of the double-bowl-shaped molecular container prepared in this example. (a) Top view; (b) Side view.

[0044] See also Figure 3 As shown, the mass spectrum of the double bowl-shaped molecular container prepared in this embodiment; from Figure 3 It can be seen that the mass spectrum of the double bowl-shaped molecular container shows that the theoretical mass-to-charge ratio (C 114 H 102 F 24 N 18 P4Br2): [M-2PF6] 2+= 1086.8094, [M-3PF6] 3+ =675.8835 and test value: [M-2PF6] 2+ = 1086.8094, [M-3PF6] 3+ = 675.8835, which shows that the double-container molecular container was successfully synthesized.

[0045] See also Figure 4 As shown in FIG, the single crystal morphology of the double bowl-shaped molecular container prepared in this embodiment; Figure 4 It can be seen that this is a macroscopic morphology image of the double-bowl-shaped molecular container single crystal. It can be clearly seen that it presents an octahedral shape, indicating that the single crystal of the double-bowl-shaped molecular container has been successfully synthesized.

[0046] See also Figure 5 As shown, nuclear magnetic titration proves that the double bowl-shaped molecular container prepared in this embodiment has the ability to recognize fluoride ions; Figure 5 It can be seen that as fluoride ions are continuously added to the double-bowl-shaped molecular container, the chemical shift of the proton located on the imidazole element in the double-bowl-shaped molecular container gradually moves to the low field, with an offset of 0.49 ppm. This is mainly because the fluoride ions are bonded to the holes in the double-bowl-shaped molecular container and interact with the protons on the imidazole element. This further confirms that the double-bowl-shaped molecular container has a recognition effect on fluoride ions.

[0047] See also Figure 6 As shown, nuclear magnetic titration proves that the double bowl-shaped molecular container prepared in this embodiment has good recognition ability for chloride ions; Figure 6 It can be seen that as chloride ions are continuously added to the double-bowl-shaped molecular container, the chemical shift of the proton located on the imidazole element in the double-bowl-shaped molecular container gradually moves to the low field, with an offset of 0.93 ppm. This is mainly because the chloride ions are bonded in the hole of the double-bowl-shaped molecular container and interact with the protons on the imidazole element. This further confirms that the double-bowl-shaped molecular container has a recognition effect on chloride ions.

[0048] Example 2 Same as Example 1, except that, 1,2,3,4,5,6-hexabromomethylbenzene and 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole were added into a single-necked flask at a molar ratio of 1:10; 3,3',3'',3''',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate and tetrabutylammonium bromide were added to a vial at a molar ratio of 1:3.

[0049] It should be noted that when there is only one anion, such as 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) bromide or 3,3',3'',3''',3'''',3''''-(phenyl-1,2,3,4,5,6-hexenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate, the single crystal structure shows that it is not a double bowl-shaped molecular container, but presents an irregular folded conformation.

[0050] See also Figure 7 As shown, the crystal structure of 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) bromide salt is shown; see Figure 8 The crystal structure of 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) hexafluorophosphate is shown.

[0051] The present invention describes preferred embodiments and their effects. However, those skilled in the art, once informed of the basic inventive concept, may make additional changes and modifications to these embodiments. Therefore, it is intended that the appended claims be interpreted to include the preferred embodiments as well as all changes and modifications that fall within the scope of the invention.

[0052] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a double-bowl-shaped molecular container based on heteroanion induction, characterized in that: The following steps are involved: Dissolve 1,2,3,4,5,6-hexabromomethylbenzene and 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole in acetonitrile, heat to 90-95° C., stir and reflux for 18-24 hours to obtain a first intermediate product; The first intermediate product was dissolved in methanol, and a saturated methanol solution of ammonium hexafluorophosphate was added dropwise under stirring until no more precipitate was formed. The stirring was continued for 30 to 40 minutes to obtain a second intermediate product. The second intermediate product and tetrabutylammonium bromide are dissolved in acetonitrile. After filtering, the filtrate is added to isopropyl ether, sealed, and left at room temperature for 12 to 24 hours to obtain a double bowl-shaped molecular container.

2. The method for preparing a double-bowl-shaped molecular container based on heteroanion induction according to claim 1, characterized in that: The molar ratio of the 1,2,3,4,5,6-hexabromomethylbenzene to 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole is 1:7-10.

3. The method for preparing a double-bowl-shaped molecular container based on heteroanion induction according to claim 1, characterized in that: The molar ratio of the second intermediate product to tetrabutylammonium bromide is 1:2-3.

4. The method for preparing a double-bowl-shaped molecular container based on heteroanion induction according to claim 1, characterized in that: The first intermediate product is 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium) bromide; The second intermediate product is 3,3',3'',3''',3'''',3'''''-(phenyl-1,2,3,4,5,6-hexaenylhexamethylene)hexamethylene(1-(2-(9H-carbazol-9-yl)ethyl)-1H-imidazol-3-ium)hexafluorophosphate.

5. The method for preparing a double-bowl-shaped molecular container based on heteroanion induction according to claim 1, characterized in that: After standing at room temperature for 12 to 24 hours, the process further comprises: filtering and washing the filter cake with isopropyl ether; After continuing stirring for 30 to 40 minutes, the process is filtered and the filter cake is washed several times with methanol and water. After refluxing for 18 to 24 hours, the mixture was cooled to room temperature and filtered, and the filter cake was washed several times with acetonitrile and dichloromethane respectively.

6. The method for preparing a double-bowl-shaped molecular container based on heteroanion induction according to claim 1, characterized in that: The second intermediate product and tetrabutylammonium bromide were dissolved in acetonitrile and filtered using a 220-micron organic filter head.

7. The method for preparing a double-bowl-shaped molecular container based on heteroanion induction according to claim 1, characterized in that: The 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole is prepared according to the following steps: Dissolve 2-(9H-carbazol-9-yl)ethanol and triphenylphosphine in acetonitrile, cool in an ice bath for 10-15 minutes, add carbon tetrabromide while stirring, continue stirring and return to room temperature, and react for 12-16 hours. After the reaction is completed, the solvent is removed under reduced pressure, and the concentrate is dissolved in dichloromethane, and then washed multiple times with a saturated sodium chloride aqueous solution and deionized water, respectively. The organic phases are combined, dried over anhydrous sodium sulfate, and the solvent is removed under reduced pressure to obtain a crude product. The crude product is separated by gel chromatography to obtain 9-(2-bromoethyl)-9H-carbazole. Imidazole and potassium hydroxide are uniformly dissolved in N,N-dimethylformamide, and 9-(2-bromoethyl)-9H-carbazole is added. After stirring and reacting at 90-100°C for 12-14 hours, 9-(2-(1H-imidazol-1-yl)ethyl)-9H-carbazole is obtained through purification.

8. The method for preparing a double-bowl-shaped molecular container based on heteroanion induction according to claim 7, characterized in that: The 2-(9H-carbazol-9-yl)ethanol is prepared according to the following steps: Carbazole and potassium hydroxide are added to N,N-dimethylformamide, stirred and mixed at room temperature, and then 2-bromoethanol is added. Subsequently, oxygen is removed by Schlenk technique. Thereafter, the solution is heated to 90-100°C under nitrogen atmosphere and stirred for 16-24 hours. After post-treatment, 2-(9H-carbazol-9-yl)ethanol is obtained.

9. A double-bowl-shaped molecular container based on heteroanion induction prepared by the method according to any one of claims 1 to 8.

10. Use of the double-bowl-shaped molecular container based on heteroanion induction according to claim 9 in molecular recognition, catalysis or adsorption.

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