Type I organic molecular cage porous liquid and preparation method thereof

Abstract

The invention relates to an I-type organic molecular cage porous liquid and a preparation method thereof. The method comprises the following steps: taking an organic molecular cage containing Lewis base as a core, taking a polyethylene glycol oligomer containing Bronsted acid as a liquefying reagent, and carrying out acid-base reaction to obtain an ionized organic molecular cage and a polyethylene glycol oligomer; the two are subjected to supramolecular assembly under the action of electrostatic complexation to directly form the I-type organic molecular cage porous liquid with a permanent microporous structure. The prepared porous liquid is in a uniform transparent state at room temperature, has good fluidity, and shows excellent CO2 gas adsorption and gas phase and liquid phase iodine molecule capture performance. The I-type organic molecular cage porous liquid is simple in preparation method, high in synthesis efficiency, low in cost and convenient for large-scale synthesis, and the single-time synthesis yield can exceed 1kg; a new thought can be provided for design synthesis, large-scale production and application of the porous liquid, and industrial development of the porous liquid material is expected to be promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of porous material synthesis, and particularly relates to a type-I organic molecular cage porous liquid material having fluidity at room temperature, a preparation method thereof, and applications in CO 2 gas adsorption and the capture of iodine molecules in the gas phase and liquid phase. Background Art

[0002] Porous materials are a class of solid materials with permanent and rigid pore structures. Their rich and interconnected internal pore structures show broad application prospects in the fields of gas adsorption and separation, mass transfer, catalysis, sensing, and energy storage. However, most solid porous materials exist in the form of powders, which brings great inconvenience to the processing, transportation, storage, and use of the materials. As early as 2007, James et al. proposed the concept of porous liquids, that is, liquid materials with permanent porosity, and classified porous liquids: type-I porous liquids refer to liquid materials composed purely of molecules with cavity structures, type-II refers to liquid materials formed by dissolving molecules with cavity structures in sterically hindered solvents, and type-III refers to liquid materials formed by uniformly dispersing porous materials in sterically hindered solvents. Porous liquid materials can combine the characteristics of the rigid porous structure of solids and the fluidity of liquids. Among them, the rigid pores can store substances / energy, and the fluidity enables them to shorten the diffusion path through stirring and other means, thus showing good heat transfer and mass transfer properties. Therefore, porous liquids show unique advantages and great application potential in gas adsorption, material separation, etc.

[0003] However, due to the contradictory properties of rigid pores and liquid fluidity, it is a great challenge to construct a cavity structure with permanent porosity in liquids, and there are not many reported successful cases so far. At the same time, type-II and type-III porous liquids are essentially mixtures, and their use process is greatly affected by sterically hindered solvents, and there are problems such as unstable porous structures, limited selection of solvent types, easy volatilization of solvents, low pore volume content, and uneven pore structure distribution. Although type-I porous liquids can effectively avoid the above problems, their synthesis routes are relatively complex and the synthesis efficiency is not high, which hinders their further development. Therefore, designing and developing a general method for simply and efficiently synthesizing type-I porous liquids is an urgent problem to be solved in the development of porous liquid materials at present. Summary of the Invention

[0004] The purpose of the present invention is to provide a type-I organic molecular cage porous liquid and a preparation method thereof. The preparation method is simple and has high synthesis efficiency, and can realize the large-scale synthesis of porous liquids. The single synthesis output can exceed 1 kilogram; the prepared porous liquid has a permanent and stable cavity structure and good fluidity, and shows excellent CO 2 gas adsorption and the performance of capturing iodine molecules in the gas phase and liquid phase.

[0005] In the first aspect of the present invention, a class of type I organic molecular cage porous liquids is provided. The porous liquid is directly formed by the supramolecular assembly of ionized organic molecular cages and polyethylene glycol oligomers through electrostatic complexation, and the molar ratio between the two is 1:3 to 1:12.

[0006] The organic molecular cage is cationic, and the positively charged group attached thereto is a quaternary ammonium salt group, and the number of positively charged groups attached to each molecular cage is 3 to 12.

[0007] The polyethylene glycol oligomer is anionic, and the negatively charged group attached thereto is a carboxylate group, a sulfonate group, etc., and the number of negatively charged groups attached to each polyethylene glycol oligomer is 1.

[0008] The organic molecular cage framework nodes carry positive charges and repel each other, which can effectively avoid the collapse of the molecular cage framework; the molecular cage window has a high charge density and strong hydrophilicity, which can avoid the insertion of the hydrophobic alkyl end of the polyethylene glycol oligomer to the greatest extent, so a permanently stable cavity structure is shown.

[0009] In the second aspect of the present invention, a preparation method of a class of type I organic molecular cage porous liquids is provided, which specifically includes the following steps:

[0010] Step 1: Synthesis of imine bond organic molecular cages

[0011] The aldehyde and amine monomers required for synthesizing the imine bond organic molecular cages are respectively added to an organic solvent in a certain proportion, stirred well to dissolve them, and then stirred and reacted at room temperature.

[0012] Step 2: Reduction of imine bond organic molecular cages

[0013] The reducing agent is added to the reaction solution obtained in Step 1 in a certain proportion, and stirred and reacted at room temperature; then, the solvent is removed by rotary evaporation, the remaining solid is washed with water multiple times, and vacuum dried to obtain a reduced organic molecular cage containing secondary amine groups.

[0014] Step 3: Preparation of porous liquids

[0015] The reduced organic molecular cage containing secondary amine groups obtained in Step 2 is directly added to the polyethylene glycol oligomer liquid containing Bronsted acid groups in a certain proportion, and stirred and reacted at room temperature. After the reduced organic molecular cage is completely dissolved, a homogeneous, transparent viscous liquid is the type I organic molecular cage porous liquid.

[0016] In the above preparation method, in step 1, when the aldehyde is a trialdehyde, it includes 1,3,5-benzenetricarboxaldehyde, 2-hydroxy-1,3,5-benzenetricarboxaldehyde, etc., and when the amine is a diamine, it includes ethylenediamine, 1,3-propanediamine, 1,2-cyclohexanediamine, 1,2-cyclopentanediamine, etc. At this time, the molar ratio of aldehyde to amine is 4:6, and the synthesized organic molecular cages include but are not limited to CC1, CC2, CC3, CC3-OH, CC4, etc.;

[0017] CC1 is synthesized from 1,3,5-benzenetricarboxaldehyde and ethylenediamine, and its molecular formula is C 48 H 48 N 12 ;

[0018] CC2 is synthesized from 1,3,5-benzenetricarboxaldehyde and 1,3-propanediamine, and its molecular formula is C 54 H 60 N 12 ;

[0019] CC3 is synthesized from 1,3,5-benzenetricarboxaldehyde and 1,2-cyclohexanediamine, and its molecular formula is C 72 H 84 N 12 ;

[0020] CC3-OH is synthesized from 2-hydroxy-1,3,5-benzenetricarboxaldehyde and 1,2-cyclohexanediamine, and its molecular formula is C 72 H 84 N 12 O 4 ;

[0021] CC4 is synthesized from 1,3,5-benzenetricarboxaldehyde and 1,2-cyclopentanediamine, and its molecular formula is C 66 H 72 N 12 .

[0022] When the aldehyde is a dialdehyde, it includes isophthalaldehyde, terephthalaldehyde, 4,4'-biphenyldicarboxaldehyde, etc., and when the amine is a triamine, it includes tris(2-aminoethyl)amine, tris(2-aminopropyl)amine, etc. At this time, the molar ratio of aldehyde to amine is 3:2, and the synthesized organic molecular cages include but are not limited to A3T2, D3T2, F3T2, etc.

[0023] A3T2 is synthesized from isophthalaldehyde and tris(2-aminoethyl)amine, and its molecular formula is C 36 H 42 N 8 ;

[0024] D3T2 is synthesized from terephthalaldehyde and tris(2-aminoethyl)amine, and its molecular formula is C 36 H 42 N 8 ;

[0025] F3T2 is synthesized from 4,4'-biphenyldicarboxaldehyde and tris(2-aminoethyl)amine, and its molecular formula is C 54 H 54 N 8 。

[0026] In the above preparation method, in step 1, the organic solvent is one or more of dichloromethane, chloroform, methanol, tetrahydrofuran, and acetone, and the mass / volume (g / mL) ratio of the aldehyde monomer to the organic solvent is 1:10 to 1:80.

[0027] In the above preparation method, in step 1, the stirring rate is 100 to 600 rpm, and the reaction time is 4 to 48 hours.

[0028] In the above preparation method, in step 2, the reducing agent is sodium borohydride, ammonia borane, dimethylamine borane, hydrazine hydrate, etc., and the molar ratio of the reducing agent to the imine bond is 0.5:1 to 4:1.

[0029] In the above preparation method, in step 2, the stirring rate is 300 to 1200 rpm, the reaction time is 12 to 48 hours, the rotary evaporation temperature is 20 to 50 °C, the number of water washes is 3 to 5 times, the vacuum drying temperature is 50 to 80 °C, and the vacuum drying time is 12 to 48 hours.

[0030] In the above preparation method, in step 3, the poly(ethylene glycol) oligomer containing a Bronsted acid group is composed of an alkyl group, a polyethylene glycol chain, and a Bronsted acid group. Among them, the alkyl group is a benzene ring, a long aliphatic chain, etc., the Bronsted acid group is a carboxylic acid, a sulfonic acid group, etc., and the degree of polymerization of ethylene glycol is 5 to 20. Including but not limited to lauryl polyoxyethylene ether carboxylic acid, with a molecular weight of about 360 to 690 g / mol; oleyl polyoxyethylene ether carboxylic acid, with a molecular weight of about 720 g / mol; 4-tert-butylphenol polyoxyethylene ether carboxylic acid, with a molecular weight of about 430 g / mol; lauryl polyoxyethylene ether sulfonic acid, with a molecular weight of about 310 g / mol, etc.

[0031] In the above preparation method, in step 3, the molar ratio between the reduced organic molecular cage (synthesized from a molar ratio of tri-aldehyde to di-amine of 4:6) and the poly(ethylene glycol) oligomer containing a Bronsted acid group is 1:4 to 1:12; the molar ratio between the reduced organic molecular cage (synthesized from a molar ratio of di-aldehyde to tri-amine of 3:2) and the poly(ethylene glycol) oligomer containing a Bronsted acid group is 1:3 to 1:6.

[0032] In the above preparation method, in step 3, the stirring rate is 300 to 1200 rpm, and the reaction time is 12 to 48 hours.

[0033] The type-I organic molecular cage porous liquid prepared by the present invention is applied to the adsorption of CO 2 gas and the capture of iodine molecules in the gas phase and liquid phase.

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

[0035] 1. The type-I organic molecular cage porous liquid proposed by the present invention has a simple composition. Among them, the ionized organic molecular cage has a stable structure and can provide a rigid and stable microporous structure; the polyethylene glycol oligomer has a low viscosity and can provide good fluidity.

[0036] 2. The preparation method uses electrostatic complexation to perform "one-step" supramolecular assembly on the organic molecular cage and polyethylene glycol oligomer, avoiding complex and cumbersome synthesis and functionalization routes. The method is simple, has a high synthesis efficiency, is convenient for large-scale preparation, and its single synthesis output can exceed 1 kilogram.

[0037] 3. The preparation method has good universality. By combining different organic molecular cages and polyethylene glycol oligomers, a series of type-I porous liquids can be obtained, and the regulation of the cavity size, pore volume ratio, liquid viscosity, fluidity and function of the porous liquid can be realized.

[0038] 4. The preparation method has a single process route and low requirements for equipment; no post-treatment is required and the energy consumption is low; therefore, the production cost can be effectively reduced, and it is expected to be applied to industrial production and promote the industrial development of porous liquid materials. Description of the Drawings

[0039] Figure 1 It is a schematic diagram of the synthesis route for preparing the PLcage-1 porous liquid in Example 1 of the present invention.

[0040] Figure 2 It is the Fourier transform infrared spectrum of the PLcage-1 porous liquid prepared in Example 1 of the present invention.

[0041] Figure 3 It is the 1 H-NMR diagram of the PLcage-1 porous liquid prepared in Example 1 of the present invention.

[0042] Figure 4 It is the positron annihilation lifetime spectrum of the PLcage-1 porous liquid prepared in Example 1 of the present invention.

[0043] Figure 5 It is the DSC curve of the PLcage-1 porous liquid prepared in Example 1 of the present invention.

[0044] Figure 6 It is the CO 2 gas adsorption isotherm of the PLcage-1 porous liquid prepared in Example 1 of the present invention.

[0045] Figure 7 These are the photos of PLcage-1 porous liquid before and after gas-phase capturing of iodine molecules in Example 1 of the present invention.

[0046] Figure 8 This is the adsorption curve of PLcage-1 porous liquid for gas-phase capturing of iodine molecules in Example 1 of the present invention.

[0047] Figure 9 These are the photos of PLcage-1 porous liquid before and after liquid-phase capturing of iodine molecules in Example 1 of the present invention.

[0048] Figure 10 This is the UV-Vis absorption spectrum of PLcage-1 porous liquid for liquid-phase capturing of iodine molecules in Example 1 of the present invention.

[0049] Figure 11 This is the CO 2 gas adsorption isotherm of PLcage-2 porous liquid prepared in Example 2 of the present invention.

[0050] Figure 12 This is the Fourier transform infrared spectrum of PLcage-3 porous liquid prepared in Example 3 of the present invention.

[0051] Figure 13 This is the CO 2 gas adsorption isotherm of PLcage-3 porous liquid prepared in Example 3 of the present invention.

[0052] Figure 14 This is the adsorption curve of PLcage-4 porous liquid for gas-phase capturing of iodine molecules in Example 4 of the present invention.

[0053] Figure 15 These are the photos of large-scale preparation of PLcage-1 porous liquid in Example 5 of the present invention.

[0054] Figure 16 These are the 1 1H-NMR spectra of large-scale preparation of PLcage-1 porous liquid in Example 5 of the present invention.

[0055] Figure 17 This is the CO 2 gas adsorption isotherm of large-scale preparation of PLcage-1 porous liquid in Example 5 of the present invention. Detailed implementation manners

[0056] The following further elaborates on the type-I organic molecular cage porous liquid and its preparation method involved in the present invention through specific examples in combination with the attached drawings. It should be noted that the following specific examples are only exemplary in nature, aiming to explain the details involved in the present invention and should not be construed as a limitation to the present invention.

[0057] In the following examples, the drugs and solvents involved, unless otherwise specified, are commercially available reagent products.

[0058] Example 1

[0059] (1) Weigh 0.65 g (4 mmol) of 1,3,5-benzenetricarbaldehyde and add it to a 20 mL dichloromethane / methanol mixed solution (volume ratio 1:1). Stir at 300 rpm for 5 minutes to completely dissolve it. Then, weigh 0.69 g (6 mmol) of 1,2-cyclohexanediamine and add it to the above solution at the same rotation speed. Under room temperature conditions, continuously stir and react for 24 hours. At this time, the synthesized CC3 molecular cage is completely dissolved in the dichloromethane / methanol mixed solution.

[0060] (2) Filter the above CC3 molecular cage solution to remove insoluble impurities. Weigh 0.91 g (24 mmol) of sodium borohydride and add it to the filtered solution in two portions at 600 rpm (the time interval between additions is 10 minutes). Then, under room temperature conditions, continuously stir and react for 24 hours. After the reaction is completed, remove the reaction solvent by rotary evaporation at 20 °C (the reaction solvent obtained by rotary evaporation can be recycled and reused). Add 50 mL of deionized water to the solid obtained by rotary evaporation, fully shake it, and then filter it to obtain a white solid powder. Add 50 mL of deionized water again, fully shake it, and then filter it. Repeat this 3 times, and then put the obtained white solid powder into a vacuum drying oven and vacuum dry it at 50 °C for 24 hours to finally obtain a reduced CC3 organic molecular cage containing secondary amine groups.

[0061] (3) Weigh 8.28 g (12 mmol) of lauryl polyoxyethylene ether carboxylic acid (ethylene glycol polymer is 10, molecular weight is 690 g / mol), and weigh 1.14 g (1 mmol) of the reduced CC3 organic molecular cage obtained in step 2, and directly add it to the above weighed lauryl polyoxyethylene ether carboxylic acid. Under room temperature and 600 rpm rotation speed, continuously stir and react. After 24 hours, the reduced CC3 organic molecular cage is completely dissolved in lauryl polyoxyethylene ether carboxylic acid to form a homogeneous, transparent, and viscous porous liquid of the organic molecular cage, denoted as PLcage-1.

[0062] The PLcage-1 porous liquid is composed of a cationized reduced CC3 organic molecular cage (with 12 quaternary ammonium salt groups attached) and lauryl polyoxyethylene ether carboxylate anions, and the ratio of the two is 1:12. Its synthetic route is as Figure 1 shown.

[0063] Figure 2 is the Fourier transform infrared spectrum of the PLcage-1 porous liquid. It can be observed from the figure that at 3500 cm-1 A broad peak attributed to N-H stretching vibration at a wavenumber and a stretching vibration peak attributed to C-O-C at 1091 cm -1 The stretching vibration peak attributed to C-O-C at a wavenumber indicates the presence of organic molecular cages and polyvinyl alcohol oligomers in the porous liquid; while at 1608 and 1461 cm -1 The stretching vibration peak attributed to equal -COO - The stretching vibration peak of C-O in it proves the formation of carboxylate anions.

[0064] Figure 3 For the 1 H-NMR spectrum of PLcage-1 porous liquid, the chemical shifts at 7.14 and 2.27 ppm in the CC3 organic molecular cage move to higher fields to 7.36 and 2.82 ppm respectively after the formation of the porous liquid, indicating a decrease in the outer electron cloud density of the corresponding proton hydrogens, predicting the formation of electron-deficient quaternary ammonium groups on the molecular cage skeleton.

[0065] Figure 4 For the positron annihilation lifetime spectrum of PLcage-1 porous liquid. By fitting the positron annihilation lifetime spectrum, the annihilation lifetime of positronium obtained is 2.69 ns, and thus the corresponding pore size of the porous liquid is calculated to be about 0.68 nm. This size is consistent with the inner cavity size of the CC3 molecular cage reported in the literature, proving that the cationic molecular cage and anionic polyethylene glycol oligomers can maintain the inner cavity structure of the molecular cage during the supramolecular assembly process.

[0066] Figure 5 For the DSC curve of PLcage-1 porous liquid, the glass transition temperature of the porous liquid in the figure is about 23 °C, indicating that PLcage-1 can exist in liquid form at room temperature and has good fluidity.

[0067] Application examples

[0068] The PLcage-1 porous liquid prepared in Example 1 of the present invention is respectively used for CO 2 gas adsorption, gas-phase and liquid-phase capture of iodine molecules.

[0069] The CO 2 gas adsorption performance of PLcage-1 porous liquid is tested by an ASAP2020 full-automatic gas adsorption instrument, and the test temperature is 273 K, and the CO 2 gas pressure is 1 bar. Figure 6 For the CO 2 gas adsorption isotherm of PLcage-1 porous liquid. It can be seen from the figure that: PLcage-1 has an adsorption capacity for CO 2It shows reversible adsorption behavior that changes with pressure, which belongs to the category of physical adsorption. The maximum adsorption capacity is 0.41mmol / g, which is better than most type I porous liquids.

[0070] The specific steps of the PLcage-1 porous liquid gas phase capture iodine molecule experiment are as follows:

[0071] Take 100 mg of PLcage-1 porous liquid and place it at the bottom of a 3 mL open transparent glass bottle. Weigh its mass and record it as m1 in mg. Then, put it into another sealed container, in which 1 g of iodine is weighed and placed at the bottom of the bottle. Put the entire device into a 75°C constant temperature oven, take it out at regular intervals, and after it cools to room temperature, take out the vial containing the PLcage-1 porous liquid, weigh its mass and record it as m2 in mg. The gas phase capture experiment of iodine molecules lasts for 36 hours. The adsorption amount of iodine molecules by the porous liquid is calculated by the following formula, and the adsorption curve is drawn.

[0072]

[0073] Figure 7 The photos are before and after the PLcage-1 porous liquid gas phase captures iodine molecules. From the photos, it can be seen that after the iodine molecules are captured, the color of the porous liquid changes from light yellow to dark brown.

[0074] Figure 8 This is the adsorption curve of iodine molecules captured by PLcage-1 porous liquid in gas phase. In the first 10 hours, the adsorption of iodine molecules by the porous liquid increased rapidly, and then the adsorption rate gradually slowed down. After 30 hours, the adsorption equilibrium was basically reached, and the maximum adsorption amount was about 110wt%.

[0075] The specific steps of the PLcage-1 porous liquid phase capture iodine molecule experiment are as follows:

[0076] Take 100 mg of PLcage-1 porous liquid and place it at the bottom of a 3 mL transparent glass bottle. Then, add 2 mL of iodine molecule petroleum ether solution (concentration is 1 mg / mL) to the glass bottle. After sealing the glass bottle, place it on an oscillator and perform liquid phase capture of iodine molecules at an oscillation rate of 60 rpm. Every 20 minutes, the upper layer of iodine molecule petroleum ether solution is sucked out and UV-Vis absorbance test is performed. The liquid phase capture experiment of iodine molecules lasts for 4 hours.

[0077] Figure 9 The photos are before and after the PLcage-1 porous liquid captures iodine molecules. From the photos, we can see that the porous liquid can completely absorb the iodine molecules in the solution. The iodine molecule petroleum ether solution changes from the initial pink to colorless and transparent after the capture. The color of the porous liquid after the capture of iodine molecules is slightly darker.

[0078] Figure 10 UV-Vis absorption spectrum of iodine molecules captured by PLcage-1 porous liquid in the liquid phase. As the capture time prolongs, the UV-Vis absorbance of the iodine molecule petroleum ether solution gradually decreases and approaches 0 after 4 hours, indicating that the iodine molecules in the solution have been completely captured.

[0079] Example 2

[0080] (1) Weigh 0.65 g (4 mmol) of 1,3,5-benzenetricarbaldehyde and add it to 20 mL of a dichloromethane / methanol mixed solution (volume ratio 1:1). Stir it at 300 rpm for 5 minutes to completely dissolve it. Then, weigh 0.69 g (6 mmol) of 1,2-cyclohexanediamine and add it to the above solution at the same rotation speed. Under room temperature conditions, continuously stir and react for 24 hours. At this time, the synthesized CC3 molecular cage is completely dissolved in the dichloromethane / methanol mixed solution.

[0081] (2) Filter the above CC3 molecular cage solution to remove insoluble impurities. Weigh 0.91 g (24 mmol) of sodium borohydride and add it to the filtered solution in two portions at 600 rpm (the time interval between additions is 10 minutes). Then, under room temperature conditions, continuously stir and react for 24 hours. After the reaction is completed, remove the reaction solvent by rotary evaporation at 20 °C (the reaction solvent obtained by rotary evaporation can be recycled and reused). Add 50 mL of deionized water to the solid obtained by rotary evaporation, shake it well and then filter it to obtain a white solid powder. Add 50 mL of deionized water again, shake it well and then filter it. Repeat this 3 times, and then put the obtained white solid powder into a vacuum drying oven and vacuum dry it at 50 °C for 24 hours to finally obtain a reduced CC3 organic molecular cage containing secondary amine groups.

[0082] (3) Weigh 1.86 g (6 mmol) of lauryl polyoxyethylene ether sulfonic acid (molecular weight 310 g / mol), weigh 1.14 g (1 mmol) of the reduced CC3 organic molecular cage obtained in step 2, and directly add it to the above weighed lauryl polyoxyethylene ether sulfonic acid. Under room temperature and at 1200 rpm, continuously stir and react. After 24 hours, the reduced CC3 organic molecular cage is completely dissolved in lauryl polyoxyethylene ether sulfonic acid to form a homogeneous, transparent and viscous organic molecular cage porous liquid, denoted as PLcage-2.

[0083] PLcage-2 porous liquid is composed of a cationized reduced CC3 organic molecular cage (with 6 quaternary ammonium salt groups attached) and lauryl polyoxyethylene ether sulfonate anions, and the ratio of the two is 1:6.

[0084] Application Example

[0085] The PLcage-2 porous liquid prepared in Example 2 of the present invention was used for CO 2 gas adsorption.

[0086] The CO 2 gas adsorption performance of the PLcage-2 porous liquid was tested using an ASAP2020 fully automatic gas sorption analyzer at a test temperature of 273 K and a CO 2 gas pressure of 1 bar. Figure 11 Shown is the CO 2 gas adsorption isotherm of the PLcage-2 porous liquid. As can be seen from the figure, the adsorption behavior of PLcage-2 for CO 2 is similar to that of PLcage-1, showing reversible adsorption with changing pressure, belonging to the category of physical adsorption; its maximum adsorption capacity is 0.57 mmol / g, higher than that of PLcage-1. The reason is that PLcage-2 has a higher molecular cage content and exposes more secondary amine group adsorption sites.

[0087] Example 3

[0088] (1) Weigh 0.65 g (4 mmol) of 1,3,5-benzenetricarbaldehyde and add it to 40 mL of a dichloromethane / methanol mixed solution (volume ratio 1:1). Stir at 300 rpm for 5 minutes to completely dissolve it. Then, weigh 0.36 g (6 mmol) of ethylenediamine and add it to the above solution at the same rotation speed. Under the conditions of room temperature and 600 rpm rotation speed, continuously stir and react for 24 hours. At this time, the synthesized CC1 molecular cage is completely dissolved in the dichloromethane / methanol mixed solution.

[0089] (2) Filter the above CC1 molecular cage solution to remove insoluble impurities. Weigh 0.46 g (12 mmol) of sodium borohydride and add it to the filtered solution in two portions at 1200 rpm (the time interval between additions is 30 minutes). Then, under the condition of room temperature, continuously stir and react for 24 hours. After the reaction, remove the reaction solvent by rotary evaporation at 20 °C (the recovered reaction solvent can be reused after recycling). Add 50 mL of deionized water to the solid obtained by rotary evaporation, shake well and then filter by suction to obtain a white solid powder. Add 50 mL of deionized water again, shake well and then filter by suction. Repeat this 3 times, and then put the obtained white solid powder into a vacuum drying oven and vacuum dry it at 50 °C for 24 hours to finally obtain a reduced CC1 organic molecular cage containing secondary amine groups.

[0090] (3) Weigh 8.28 g (12 mmol) of lauryl polyoxyethylene ether carboxylic acid (ethylene glycol polymer is 10, molecular weight is 690 g / mol), and weigh 0.82 g (1 mmol) of the reduced CC1 organic molecular cage obtained in step 2. Add it directly to the above-weighed lauryl polyoxyethylene ether carboxylic acid, and continuously stir and react at room temperature and a rotation speed of 1200 rpm. After 24 hours, the reduced CC1 organic molecular cage is completely dissolved in lauryl polyoxyethylene ether carboxylic acid, forming a homogeneous, transparent, and viscous organic molecular cage porous liquid, denoted as PLcage-3.

[0091] The PLcage-3 porous liquid is composed of a cationized reduced CC1 organic molecular cage (with 12 quaternary ammonium salt groups attached) and lauryl polyoxyethylene ether carboxylate anions, and the ratio of the two is 1:12.

[0092] Figure 12 is the Fourier transform infrared spectrum of the PLcage-3 porous liquid. The positions of the infrared characteristic peaks of PLcage-3 and PLcage-1 are similar, indicating that they have similar chemical structures.

[0093] Application Example

[0094] The PLcage-3 porous liquid prepared in Example 3 of the present invention is used for CO 2 gas adsorption.

[0095] The CO 2 gas adsorption performance of the PLcage-3 porous liquid is tested by an ASAP2020 fully automatic gas adsorption instrument, and the test temperature is 273 K and the CO 2 gas pressure is 1 bar. Figure 13 is the CO 2 gas adsorption isotherm of the PLcage-3 porous liquid, and its maximum adsorption capacity is 0.36 mmol / .

[0096] Example 4

[0097] (1) Weigh 0.41 g (3 mmol) of isophthalaldehyde, add it to a 10 mL dichloromethane / methanol mixed solution (volume ratio is 1:1), and stir at a rotation speed of 600 rpm for 5 minutes to completely dissolve it. Then, weigh 0.30 g (2 mmol) of tris(2-aminoethyl)amine and add it to the above solution at the same rotation speed. Under room temperature conditions, continuously stir and react for 24 hours. At this time, the synthesized A3T2 molecular cage is completely dissolved in the dichloromethane / methanol mixed solution.

[0098] (2) Filter the above A3T2 molecular cage solution to remove insoluble impurities. Weigh 0.46 g (12 mmol) of sodium borohydride and add it to the filtered solution in two portions at a rotation speed of 1200 rpm (the time interval between additions is 10 minutes). Then, under room temperature conditions, continuously stir and react for 24 hours. After the reaction is completed, remove the reaction solvent by rotary evaporation at 30 °C (the reaction solvent obtained by rotary evaporation can be recycled and reused). Add 20 mL of deionized water to the solid obtained by rotary evaporation, fully shake it, and then filter it to obtain a white solid powder. Add 20 mL of deionized water again, fully shake it, and then filter it. After repeating this 3 times, put the obtained white solid powder into a vacuum drying oven and vacuum dry it at 70 °C for 24 hours to finally obtain a reduced A3T2 organic molecular cage containing secondary amine groups.

[0099] (3) Weigh 4.14 g (6 mmol) of lauryl polyoxyethylene ether carboxylic acid (ethylene glycol polymer is 10, molecular weight is 690 g / mol), weigh 0.70 g (1 mmol) of the reduced A3T2 organic molecular cage obtained in step (2), and directly add it to the above-mentioned weighed lauryl polyoxyethylene ether carboxylic acid. Under room temperature and a rotation speed of 600 rpm, continuously stir and react. After 24 hours, the reduced A3T2 organic molecular cage is completely dissolved in lauryl polyoxyethylene ether carboxylic acid to form a homogeneous, transparent, and viscous organic molecular cage porous liquid, denoted as PLcage-4.

[0100] The PLcage-4 porous liquid is composed of a cationized reduced A3T2 organic molecular cage (with 6 quaternary ammonium salt groups attached) and lauryl polyoxyethylene ether carboxylate anions, and the ratio of the two is 1:6.

[0101] Application Example

[0102] Use the PLcage-4 porous liquid prepared in Example 4 of the present invention for gas-phase capture of iodine molecules. The specific experimental steps are the same as those of PLcage-1.

[0103] Figure 14 This is the adsorption curve of the PLcage-4 porous liquid for gas-phase capture of iodine molecules. The adsorption amount of the PLcage-4 porous liquid for iodine molecules gradually increases with time and reaches a maximum value of 93 wt% at 36 hours.

[0104] Example 5

[0105] For the large-scale preparation of PLcage-1 porous liquid, the steps are as follows. Steps 1 and 2 are the same as in Example 1. In Step 3: Weigh 911 g (about 1.32 mol) of lauryl alcohol polyoxyethylene ether carboxylic acid (ethylene glycol polymer is 10, molecular weight is 690 g / mol), and weigh 126 g (about 0.11 mol) of reduced CC3 organic molecular cage. Add it to the above-mentioned weighed lauryl alcohol polyoxyethylene ether carboxylic acid in batches, and continuously stir and react at room temperature and a rotation speed of 1200 rpm. After 48 hours, the reduced CC3 organic molecular cage is completely dissolved in lauryl alcohol polyoxyethylene ether carboxylic acid, forming a homogeneous, transparent and viscous organic molecular cage porous liquid PLcage-1. Weigh its mass, which is about 1037 g.

[0106] Figure 15 Photo of the large-scale preparation of PLcage-1 porous liquid.

[0107] Figure 16 For the large-scale preparation of PLcage-1 porous liquid 1 1H-NMR spectrum, whose proton chemical shift is the same as that of the PLcage-1 porous liquid prepared in Example 1, indicating that the two have the same chemical structure.

[0108] Application Example

[0109] The PLcage-1 porous liquid prepared in large quantities in Example 5 of the present invention is used for CO 2 gas adsorption.

[0110] CO of the PLcage-1 porous liquid prepared in large quantities 2 The gas adsorption performance of the gas is tested by an ASAP2020 fully automatic gas adsorption instrument, and the test temperature is 273 K and the CO 2 gas pressure is 1 bar. Figure 17 CO of the PLcage-1 porous liquid prepared in large quantities 2 gas adsorption isotherm, whose maximum adsorption capacity is 0.40 mmol / g, which is similar to the adsorption capacity of the PLcage-1 prepared in Example 1.

[0111] The above results show that: The large-scale preparation of PLcage-1 porous liquid has no effect on its structure and performance.

[0112] It should be emphasized that:

[0113] The above specific embodiments are only used to explain the details involved in the present invention, rather than to limit the technical solutions described in the present invention. Those skilled in the art should easily understand and can modify or equivalently replace the technical solutions of the present invention; any modification, equivalent replacement, improvement, etc. made to the technical solutions of the present invention within the spirit and principle of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A type I organic molecular cage porous liquid, characterized in that: The porous liquid is directly formed by supramolecular assembly of ionized organic molecular cages and polyethylene glycol oligomers through electrostatic complexation, and the molar ratio between the two is 1:3 to 1:

12.

2. The type I organic molecular cage porous liquid according to claim 1, characterized in that: The organic molecular cage is of cationic type and has positively charged groups; the polyethylene glycol oligomer is of anionic type and has negatively charged groups.

3. The type I organic molecular cage porous liquid according to claim 2, characterized in that: The positively charged groups of the organic molecular cage are quaternary ammonium salt groups, and the number of positive charges attached to each molecular cage is 3 to 12; the negatively charged groups of the polyethylene glycol oligomer are carboxylate groups or sulfonate groups, and the number of negative charges attached to each polyethylene glycol oligomer is 1.

4. A method for preparing a type I organic molecular cage porous liquid, characterized in that: The steps include: Step 1: Synthesis of imine bonded organic molecular cages The aldehyde and amine monomers required for synthesizing the imine bond organic molecular cage are added to an organic solvent in a certain proportion, stirred sufficiently to dissolve them, and then stirred to react at room temperature; Step 2: Reduction of the imine bonded organic molecular cage Adding a reducing agent in a certain proportion to the reaction solution obtained in step 1, stirring the reaction at room temperature; then, removing the solvent by rotary evaporation, washing the remaining solid with water for multiple times, and vacuum drying to obtain a reduced organic molecular cage containing a secondary amine group; Step 3: Preparation of porous liquid The reduced organic molecular cage containing secondary amine groups obtained in step 2 is directly added to the polyethylene glycol oligomer liquid containing Bronsted acid groups in a certain proportion, and the reaction is stirred at room temperature. After the reduced organic molecular cage is completely dissolved, a uniform, transparent viscous liquid is formed, which is the type I organic molecular cage porous liquid.

5. The preparation method according to claim 4, characterized in that: In step 1, When the aldehyde is a trialdehyde, it is 1,3,5-benzenetricarboxaldehyde or 2-hydroxy-1,3,5-benzenetricarboxaldehyde, and when the amine is a diamine, it is ethylenediamine, 1,3-propylenediamine, 1,2-cyclohexanediamine or 1,2-cyclopentanediamine, and the molar ratio of the aldehyde to the amine is 4:6; When the aldehyde is a dialdehyde, it is isophthalaldehyde, terephthalaldehyde or 4,4'-biphenyldicarboxaldehyde, and when the amine is a triamine, it is tri(2-aminoethyl)amine or tri(2-aminopropyl)amine, and the molar ratio of the aldehyde to the amine is 3:

2.

6. The preparation method according to claim 4, characterized in that: In step 1, the organic solvent is one or more of dichloromethane, chloroform, methanol, tetrahydrofuran, and acetone, and the mass / volume (g / mL) ratio of aldehyde to organic solvent is 1:10 to 1:

80.

7. The preparation method according to claim 4, characterized in that: In step 2, the reducing agent is sodium borohydride, ammonia borane, dimethylamine borane or hydrazine hydrate, and the molar ratio of the reducing agent to the imine bond is 0.5:1 to 4:

1.

8. The preparation method according to claim 4, characterized in that: In step 3, the polyethylene glycol oligomer containing Bronsted acid groups is composed of an alkyl group, a polyethylene glycol chain and a Bronsted acid group; wherein the alkyl group is a benzene ring or a long aliphatic chain, the Bronsted acid group is a carboxylic acid group or a sulfonic acid group, and the degree of polymerization of ethylene glycol is 5 to 20.

9. The preparation method according to claim 4, characterized in that: In step 3, When the reduced organic molecular cage is synthesized from trialdehyde and diamine in a molar ratio of 4:6, the molar ratio between the reduced organic molecular cage and the polyethylene glycol oligomer containing Bronsted acid groups is 1:4 to 1:12; When the reduced organic molecular cage is synthesized from dialdehyde and triamine at a molar ratio of 3:2, the molar ratio between the reduced organic molecular cage and the polyethylene glycol oligomer containing Bronsted acid groups is 1:3-1:

6.

10. The type I organic molecular cage porous liquid according to any one of claims 1 to 3 is used for CO2 gas adsorption and gas-phase and liquid-phase capture of iodine molecules.

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