Preparation method of sulfonated calixarene structure functional material and application thereof

Abstract

The application discloses a preparation method of a sulfone calixarene structure functional material and iodine adsorption-separation application. A p-tert-butyl sulfone calix[4] arene is synthesized from a thiacalix[4] arene and NaBO3 as raw materials, and a metal-organic functional material with a sulfone calixarene structure is assembled from the p-tert-butyl sulfone calix[4] arene and 4,4'-(azo-1,2-diyl)bis(2-aminobenzoic acid). The material has a special structure of a multi-stage porous material, contains multiple cavities in a cage and between cages, so that small molecule iodine can be effectively wrapped to achieve the adsorption effect. And under the action of ethanol, small molecule iodine can be separated from the functional material without affecting the structure and performance, so that the recycling and efficient separation purposes are achieved. Compared with the existing iodine adsorption-separation technology, the application has the advantages of simple preparation method, easy-to-obtain raw materials, stable structure, good adsorption effect, large adsorption capacity and good recycling performance.

Description

Technical Field

[0001] This invention belongs to the field of preparation and application of metal-organic coordination supramolecular compounds. Specifically, it relates to a method for preparing metal-organic functional materials based on sulfonylcalixarene structures and their application in the adsorption-separation of iodine. Background Technology

[0002] In recent decades, due to the rapid development of the nuclear industry, the disposal of volatile radioactive materials and nuclear waste has become an increasingly important topic. During nuclear fuel fission, the use of concentrated nitric acid can lead to excessively high temperatures in the system and generate large amounts of acidic substances. In subsequent processing, this inevitably releases large quantities of the radioactive element iodine, which is not environmentally friendly. 129 I is a typical radioactive isotope found in nuclear waste. It rapidly diffuses into the atmosphere, causing continuous pollution to the environment and posing a significant threat to human health. Therefore, developing simple, efficient, and easily recyclable adsorbent materials is crucial.

[0003] Currently, various materials have been used for the adsorption and separation of elemental iodine, such as activated carbon, zeolites, silica gel, porous organic cages (POCs), metal-organic frameworks (MOFs), and covalent organic frameworks (COFs). However, the application of most materials is limited due to unsatisfactory adsorption and high cost. For example, activated carbon, although possessing high porosity, is prone to causing secondary pollution; natural zeolites have the advantage of small pore size, allowing for selective adsorption of small molecules, but the pores are easily blocked, reducing adsorption efficiency; furthermore, some studies have reported silver-loaded zeolites, which, although exhibiting strong chemisorption capacity for iodine, suffer from the high cost and toxicity of silver; silica gel has a large adsorption capacity but lacks uniform and fixed pore size, hindering selective adsorption and separation. Metal-organic cage compounds, due to their high specific surface area and hierarchical porous structure, are considered ideal adsorption materials. However, research on the adsorption and separation of elemental iodine using such materials is still relatively rare.

[0004] With the development of supramolecular chemistry, metal-organic cage compounds have attracted much attention as a new type of porous crystalline material. Among them, calixarenes occupy an important position in the synthesis of metal-organic polyhedra due to their special structure. Among calixarenes, thiazolidinyl calixarenes[4] are the most commonly used. They contain multiple coordination sites, including oxygen atoms on hydroxyl groups and oxygen atoms on sulfonyl groups. These coordination sites can coordinate with metals, and after coordination, they form secondary building units, which then self-assemble with bridging ligands to form metal-organic polyhedra. The metal-organic polyhedra synthesized from calixarenes contain multiple cavities, including multiple outer cavities with calixarenes as vertices and an inner cavity formed after assembly with bridging ligands. It is precisely because of this special hierarchical porous structure that calixarene-based metal-organic cage compounds can encapsulate a large number of guest molecules, thereby achieving adsorption-separation effects. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a metal-organic functional material based on a sulfonyl calixarene structure and its application in iodine adsorption-separation. The metal-organic functional material is obtained by coordination assembly of p-tert-butylsulfonyl calixarene[4], 4,4'-(azo-1,2-diyl)bis(2-aminobenzoic acid) and zinc nitrate. In addition, the metal-organic functional material can be used for the adsorption and separation of radioactive iodine, and has great industrial application value and practical prospects.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for preparing functional materials based on sulfonylcalixarene structures includes the following steps:

[0008] A. Using thiacalix[4] aromatics and NaBO3 as raw materials, add chloroform, heat to 40℃ and add glacial acetic acid, heat to 50℃ and react for 18h; after the reaction is completed, add distilled water to the reaction mixture, continue stirring for 30min, add distilled water for extraction, add chloroform in small amounts several times for extraction, take the organic layer for back-extraction, add a large amount of distilled water for back-extraction, add a small amount of chloroform for extraction, then dry with anhydrous Na2SO4, filter, concentrate the filtrate to precipitate solid using a rotary evaporator, add methanol, filter and dry to obtain white solid;

[0009] B. Using 2-amino-p-nitrobenzoic acid as a raw material, NaOH was added, and the mixture was heated to 50°C under vigorous stirring. During the heating process, D-glucose solution was added, and the reaction was carried out for 2 hours. After cooling to room temperature, acetic acid was added, and the mixture was filtered and dried to obtain a red solid.

[0010] C. Place the products prepared in steps A and B into a glass bottle, add N,N'-dimethylacetamide (DMA), dissolve, add zinc nitrate hexahydrate and triethylamine, place in an oven and react for a period of time, then slowly cool to room temperature. Red single crystals precipitate out, wash with methanol and diethyl ether, and dry to obtain a metal-organic functional material based on a sulfonylcalixarene structure.

[0011] Preferably, in step A, the mass ratio of the reactants of thiacalix[4]arene and NaBO3 is 1:2.

[0012] Preferably, in step A, the volume ratio of chloroform to glacial acetic acid is 3:5.

[0013] Preferably, in step A, vacuum concentration is used when concentrating the filtrate. The conditions for vacuum concentration are a temperature not higher than 40°C and a vacuum degree of 0.09-0.1 MPa.

[0014] Preferably, in step B, the volume ratio of D-glucose solution to NaOH solution is 7:12.

[0015] Preferably, in step B, the concentration of acetic acid is 5 mol / L.

[0016] Preferably, in step C, the volume ratio of N,N'-dimethylacetamide to triethylamine is 4:1.

[0017] Preferably, in step C, the molar ratio of the product prepared in step B, 4,4'-(azo-1,2-diyl)bis(2-aminobenzoic acid), and zinc nitrate hexahydrate is 1:2:4.

[0018] Preferably, in step C, the temperature of the solvothermal treatment (oven treatment) is 100-140°C and the reaction time is 12-16 h; more preferably, the temperature of the solvothermal treatment is 100°C and the reaction time is 12 h.

[0019] The functional material prepared in this invention is a metal-organic functional material based on a sulfonylcalixarene structure. The metal-organic functional material has multiple cavities inside and between cages, which can effectively adsorb radioactive iodine. Moreover, the metal-organic functional material has good structural stability and maintains its complete structure and good performance in multiple cycles of iodine adsorption-release experiments. It can be applied to the field of iodine adsorption-separation.

[0020] The beneficial effects of this invention are:

[0021] 1. The metal-organic functional material based on the sulfonylcalixarene structure of the present invention has a novel structure with internal cavities within the cages and cavities between the cages, which can effectively adsorb radioactive iodine and maintain structural integrity while releasing iodine under specific conditions. Therefore, this material has potential application prospects in the adsorption and separation of radioactive iodine.

[0022] 2. The preparation method of the present invention is simple, the raw materials are readily available, the yield is high, the structure is stable, the adsorption effect is good, and the adsorption capacity is large. Attached Figure Description

[0023] Figure 1 The image shows the XRD pattern of the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3.

[0024] Figure 2 The infrared spectrum of the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3;

[0025] Figure 3 This is an asymmetric structural unit diagram of the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3;

[0026] Figure 4 This is a three-dimensional packing diagram of the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3;

[0027] Figure 5 The diagram shows the kinetic distribution of iodine adsorption in iodine vapor for the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3. The inset shows the color change of the organic functional material when exposed to iodine vapor.

[0028] Figure 6 The linear fitting adsorption rate constant (3.0 × 10⁻⁶) for the adsorption of iodine in iodine vapor by the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3 is given. -5 min -1 )picture;

[0029] Figure 7 The diagram shows the kinetic distribution of iodine adsorption in n-hexane solution of the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3. The inset shows the color change of the organic functional material in the n-hexane solution of iodine.

[0030] Figure 8 The linearly fitted adsorption rate constant (3.34 × 10⁻⁶) for the adsorption of iodine in a hexane solution by the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3 is given. -5 min -1 )picture;

[0031] Figure 9 The image shows the UV spectrum of the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3, which adsorbs iodine in a hexane solution.

[0032] Figure 10 This is an experiment on the desorption of iodine in ethanol after the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3 adsorbs iodine.

[0033] Figure 11 This is a cyclic experiment of iodine adsorption in iodine vapor by the metal-organic functional material based on the sulfonyl calixarene structure prepared in Example 3. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] A method for preparing tert-butylthiacalixarene includes the following steps:

[0037] Thiacalix[4]arene (2 g, 2.76 mmol) and NaBO3 (4 g, 2.6 mmol) were placed in a 250 mL double-necked flask, 60 mL of chloroform was added, the temperature was raised to 40 °C, 100 mL of glacial acetic acid was added, the temperature was raised to 50 °C, and the reaction was carried out for 18 h. After the reaction was completed, 50 mL of distilled water was added and stirred for 30 min, then poured into a separatory funnel, and 100 mL of distilled water was added for extraction. Then, 120 mL of chloroform was used for extraction three times, 40 mL each time. The organic layer was taken, back-extracted with 200 mL of distilled water, and then extracted with 20 mL of chloroform. The mixture was dried with anhydrous Na2SO4, filtered, concentrated, and 500 mL of methanol was added. After filtration, a white powder was obtained.

[0038] Example 2

[0039] The preparation method of 4,4'-(azo-1,2-diyl)bis(2-aminobenzoic acid) includes the following steps:

[0040] 3 g (16.47 mmol) of 2-amino-p-nitrobenzoic acid was placed in a 250 mL double-necked flask, and 60 mL of sodium hydroxide solution (5 mol / L) was added. The mixture was heated to 50 °C, and 35 mL of D-glucose solution (3.7 mol / L) was added during the heating process. The reaction was allowed to proceed for 2 h. After cooling to room temperature, 35 mL of acetic acid was added, and the mixture was filtered and dried to obtain a red solid.

[0041] Example 3

[0042] A method for preparing a metal-organic functional material with a sulfonylcalixarene structure includes the following steps:

[0043] The product prepared in Example 1 (8.5 mg, 0.01 mmol) and the product prepared in Example 2 (6.0 mg, 0.01 mmol) were placed in a 10 mL glass bottle. After dissolving in 0.5 mL of N,N'-dimethylacetamide (DMA), zinc nitrate hexahydrate (8.9 mg, 0.03 mmol) was added, followed by 6d triethylamine. The mixture was placed in a 100 °C oven and reacted for 12 h. Afterward, it was removed and slowly cooled to room temperature, resulting in the precipitation of red single crystals. These crystals were washed at least three times with methanol and diethyl ether, respectively. The crystals were dried to obtain red crystals. Yield: 92%. IR (KBr disk, cm⁻¹) -1 ):v=3459(w),3352(w),2961(w),1610(m),1579(w),1494(m),1438(w),1384(s),1334(w),1262(m),1 220(w),1130(m),1080(m),905(w),837(w),795(s),764(w),707(w),624(m),560(s),525(w),478(w).

[0044] The spectrum and structure of the metal-organic functional material based on the sulfonylcalixarene structure prepared in Example 3 are as follows: Figure 1-4 As shown.

[0045] Example 4

[0046] Adsorption experiments of iodine vapor on metal-organic functional materials based on sulfonylcalixarene structures from Example 3:

[0047] A 10 mg sample of calixarene-based metal-organic functional material was placed on a petri dish, and the dish containing the sample was weighed as a control. The petri dish containing the sample was then placed in a container containing iodine and sealed. The container was then heated until iodine vapor filled the entire container, and the changes in the sample were observed. At regular intervals, the petri dish containing the sample was removed and weighed, and the amount of iodine adsorbed by the calixarene-based metal-organic functional material was calculated. Observation showed that after adsorbing iodine vapor, the color of the calixarene-based metal-organic functional material changed from red to black. Figure 5 The calixarene-based metal-organic functional material achieved a maximum adsorption capacity of 380 mg / g at room temperature. A pseudo-second-order kinetic linear fitting model indicated that the adsorption rate constant of this functional material was 3.0 × 10⁻⁶. -5 min -1 ( Figure 6).

[0048] Example 5

[0049] Experiment on the ability of metal-organic functional materials based on sulfonylcalixarene structures to capture iodine in solution from Example 3:

[0050] 16 mg of calixarene-based metal-organic functional material was immersed in 4 mL of n-hexane solution, and then 0.9 mL of an iodine solution in n-hexane (15.7 mmol / L) was added. Over time, the solution color changed from purplish-red to nearly colorless. Figure 7 The calixarene-based metal-organic functional material achieved a maximum adsorption capacity of 228.42 mg / g at room temperature. A quasi-second-order kinetic linear fitting model indicated that the adsorption rate constant of this functional material was 3.34 × 10⁻⁶. -5 min -1 ( Figure 8 The UV-Vis spectrum of the solution was monitored at different time intervals. Figure 9 ), select the absorbance at the maximum wavelength of iodine (λmax=522nm), and calculate the concentration of iodine in the solution.

[0051] Example 6

[0052] Experiment on the desorption of iodine in ethanol from metal-organic functional materials based on sulfonylcalixarene structures from Example 3:

[0053] The functional material, after adsorbing iodine, was immersed in 20 mL of ethanol solution for 24 hours. For example... Figure 10 As shown, the solution gradually darkens, indicating that the captured iodine molecules were successfully transferred to the ethanol solution. The metal-organic functional material was collected by centrifugation and reactivated under vacuum at 100°C for 6 hours.

[0054] Example 7

[0055] Cyclic experiments on iodine adsorption by metal-organic functional materials based on sulfonylcalixarene structures from Example 3:

[0056] The functional materials from Example 6 were weighed and used in an iodine adsorption-desorption experiment. For example... Figure 11 As shown, this functional material retains structural integrity and good adsorption performance after five adsorption-desorption cycles.

[0057] In summary, the above implementation examples are based on the preparation method of metal-organic functional materials with sulfonylcalix aromatic structures. Thiazacalix[4]arene and NaBO3 are used as raw materials. After reaction, p-tert-butylsulfonylcalix[4]arene is obtained, and 4,4'-(azo-1,2-diyl)bis(2-aminobenzoic acid) and zinc nitrate are added for coordination, ultimately yielding the metal-organic functional material. The metal-organic functional material of this invention is a multi-level porous material with a special structure, including cavities within the cages and cavities between the cages, which can effectively encapsulate small molecule elements such as iodine (…). Figure 4 This invention not only adsorbs iodine vapor but also effectively captures iodine in n-hexane solution. Importantly, the adsorption of iodine by the material exhibits significant reversibility and recyclability; in this experiment, it maintained good adsorption performance even after five cycles. This invention provides a simple and feasible method for the adsorption-separation of iodine, and has potential practical applications in the adsorption-separation of radioactive iodine.

[0058] The above detailed embodiments provide a specific description of the analytical methods involved in this invention. It should be noted that the above description is only intended to help those skilled in the art better understand the methods and ideas of this invention, and is not intended to limit the scope of the invention. Without departing from the principles of this invention, those skilled in the art can make appropriate adjustments or modifications to this invention, and such adjustments and modifications should also fall within the protection scope of this invention.

Claims

1. A method for preparing functional materials based on sulfonylcalixarene structures, characterized in that, Includes the following steps: A. Using thiacalix[4] aromatics and NaBO3 as raw materials, add chloroform, heat to 40 °C and add glacial acetic acid, heat to 50 °C and react for 18 h; after the reaction is completed, add distilled water to the reaction mixture, continue stirring for 30 min, add distilled water for extraction, add chloroform in small amounts several times for extraction, take the organic layer for back-extraction, add a large amount of distilled water for back-extraction, add a small amount of chloroform for extraction, then dry with anhydrous Na2SO4, filter, concentrate the filtrate to precipitate solid using a rotary evaporator, add methanol, filter and dry to obtain p-tert-butylthiacalix aromatics; B. Using 2-amino-p-nitrobenzoic acid as a raw material, NaOH solution was added, and the temperature was raised to 50 °C under vigorous stirring. During the heating process, D-glucose solution was added, and the reaction was carried out for 2 h. After cooling to room temperature, acetic acid was added, and the mixture was filtered and dried to obtain 4,4'-(azo-1,2-diyl)bis(2-aminobenzoic acid). C. Place p-tert-butylthiacalixarene and 4,4'-(azo-1,2-diyl)bis(2-aminobenzoic acid) in a glass bottle, add N,N'-dimethylacetamide, dissolve, add zinc nitrate hexahydrate and triethylamine, place in an oven and react for a period of time, then slowly cool to room temperature, red single crystals precipitate, wash with methanol and diethyl ether, and dry to obtain a functional material based on the sulfonylcalixarene structure.

2. The method for preparing a functional material based on a sulfonylcalixarene structure according to claim 1, characterized in that, In step A, the mass ratio of thiacalix[4] aromatic hydrocarbon to NaBO3 is 1:

2.

3. The method for preparing a functional material based on a sulfonylcalixarene structure according to claim 1, characterized in that, In step A, the initial volume ratio of chloroform to glacial acetic acid is 3:

5.

4. The method for preparing a functional material based on a sulfonylcalixarene structure according to claim 1, characterized in that, In step A, vacuum concentration is used to concentrate the filtrate. The conditions for vacuum concentration are: temperature not higher than 40 ℃ and vacuum degree 0.09-0.1 MPa.

5. The method for preparing a functional material based on a sulfonylcalixarene structure according to claim 1, characterized in that, In step B, the volume ratio of D-glucose solution to NaOH solution is 7:

12.

6. The method for preparing a functional material based on a sulfonylcalixarene structure according to claim 1, characterized in that, In step B, the concentration of acetic acid is 5 mol / L.

7. The method for preparing a functional material based on a sulfonylcalixarene structure according to claim 1, characterized in that, In step C, the volume ratio of N,N'-dimethylacetamide to triethylamine is 4:

1.

8. The method for preparing a functional material based on a sulfonylcalixarene structure according to claim 1, characterized in that, In step C, the molar ratio of tert-butylthiacalixarene, 4,4'-(azo-1,2-diyl)bis(2-aminobenzoic acid) and zinc nitrate hexahydrate is 1:2:

4.

9. The method for preparing a functional material based on a sulfonylcalixarene structure according to claim 1, characterized in that, In step C, the oven treatment temperature is 100-140 ℃, and the time is 12-16 h.

10. An application of a functional material based on a sulfonylcalixarene structure in iodine adsorption-separation, characterized in that, The functional material based on the sulfonyl calixarene structure is prepared by the method described in any one of claims 1-9.

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