Porphyrin-based uranium adsorption and reduction material as well as preparation method and application thereof
By preparing porphyrin-based adsorption and reduction materials for uranium, and utilizing their planar conjugated rigid structure and bidentate chelation coordination of the 2,2'-bipyridine group, efficient adsorption and photocatalytic reduction of uranyl ions in seawater were achieved. This solved the problems of low adsorption efficiency, poor selectivity, and severe biofouling in existing technologies, and provided an efficient solution for uranium extraction from seawater.
Patent Information
- Application Number
- CN202511259916.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-04
- Publication Date
- 2025-12-12
AI Technical Summary
Existing seawater uranium extraction adsorbents suffer from low adsorption efficiency, poor selectivity, severe biological pollution, and low reduction efficiency, making it difficult to achieve stable adsorption-reduction in complex seawater environments.
Uranium ion adsorption and reduction were achieved using porphyrin-based materials. Por-Br was prepared by substitution reactions of 3,5-di-tert-butylbenzaldehyde, pyrrole, and p-bromobenzaldehyde. Then, Ni-Por-Br was obtained by coordination reaction with nickel acetylacetone. Ni-Por-B was obtained by substitution reaction with pinacol diboronate. Finally, 2,2'-bipyridine groups were introduced into Ni-Por-B through a Suzuki coupling reaction with 5-bromo-2,2'-bipyridine to form a stable five-membered ring structure, thus achieving efficient adsorption and photocatalytic reduction of uranyl ions.
It improves adsorption stability and selectivity, possesses antibacterial properties, and can increase adsorption capacity and achieve efficient reduction of uranyl ions under light assistance, thus solving the problem of biocontamination in the process of uranium extraction from seawater.
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Figure CN121103323A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of material science, and particularly relates to a porphyrin-based adsorption and reduction uranium material and a preparation method and application thereof. BACKGROUND
[0002] The core position of uranium in the global energy and military fields is incomparable. In the critical period of energy transformation, nuclear energy as an efficient and low-carbon energy solution is crucial to reducing carbon emissions and alleviating the energy crisis, and uranium is the core fuel driving the stable operation of nuclear power plants. In the military, uranium-based nuclear technology supports strategic deterrent forces and deeply influences the international security pattern. Therefore, exploring innovative uranium resource acquisition approaches, especially extracting uranium from vast seawater resources, has become an urgent task related to global sustainable development and strategic security.
[0003] In recent years, significant progress has been made in the field of seawater uranium extraction. Adsorption method has become a research hotspot due to its simple operation and high cost-effectiveness. Currently, various adsorbents have been developed, including synthetic organic polymers and organic metal framework materials, which have improved the adsorption efficiency and capacity to some extent. However, the field still faces many challenges. First, the selectivity of adsorption materials is insufficient, and a large number of coexisting ions in seawater seriously interfere with the adsorption of uranium, resulting in low extraction capacity and purity. Second, the attachment and growth of marine microorganisms are difficult to effectively inhibit, and the formation of biofilms not only blocks the adsorption sites but also reduces the stability and service life of the materials. In addition, the existing materials require high conditions to achieve the adsorption and reduction of uranyl ions, and have weak binding capacity with uranium, making it difficult to achieve stable adsorption-reduction in complex seawater environment.
[0004] In view of the technical problems of low adsorption efficiency, poor selectivity, serious biological pollution, and low reduction efficiency of existing seawater uranium extraction adsorbents, it is urgent to find a material that can achieve efficient and selective adsorption of uranyl ions and perform photocatalytic reduction on them, effectively overcoming the key technologies of low adsorption efficiency, poor selectivity, serious biological pollution, and low reduction efficiency of existing seawater uranium extraction technologies, and providing a new idea for solving the current problems of insufficient energy supply and serious environmental pollution. SUMMARY
[0005] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide a porphyrin-based adsorption and reduction uranium material and a preparation method and application thereof, which solve the technical problems of low adsorption efficiency, poor selectivity, serious biological pollution, and low reduction efficiency of existing seawater uranium extraction adsorbents.
[0006] In order to achieve the above purpose, the following technical solutions are adopted in the present application: One of the purposes of the present application is: The present application provides a porphyrin-based adsorption and reduction uranium material, the structural formula of which is shown as formula 1: .
[0007] The second object of the present application is: The present application provides a preparation method of the above-mentioned porphyrin-based adsorption uranium reduction material, comprising the following steps: 1) uniformly mixing 3,5-di-tert-butylbenzaldehyde and pyrrole, uniformly dispersing in a first solvent by bubbling nitrogen in a solution, adding trifluoroacetic acid as a catalyst, stirring to react, quenching after the reaction is completed, cooling, washing with water, drying, and purifying to obtain 3,5-di-tert-butylphenyl dipyrromethene; 2) uniformly mixing 3,5-di-tert-butylphenyl dipyrromethene, 3,5-di-tert-butylbenzaldehyde and p-bromobenzaldehyde, uniformly dispersing in a first solvent by bubbling nitrogen in a solution, adding trifluoroacetic acid as a catalyst, stirring to react, then adding 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, removing the solvent after the reaction is completed, purifying, and recrystallizing to obtain Por-Br, and the structural formula of Por-Br is shown as formula 2: ; 3) uniformly dispersing Por-Br in a second solvent, adding acetylacetone nickel to stir to react, filtering after the reaction is completed, and recrystallizing to obtain solid Ni-Por-Br, and the structural formula of Ni-Por-Br is shown as formula 3: ; 4) uniformly mixing and dispersing Ni-Por-Br, bis(pinacolato)diboron, potassium acetate and (1,1'-bis(diphenylphosphino)ferrocene) palladium dichloride in a third solvent, stirring to react, eluting after the reaction is completed, separating, recrystallizing to obtain solid Ni-Por-B, and the structural formula of Ni-Por-B is shown as formula 4: ; 5) uniformly mixing and dispersing Ni-Por-B, 5-bromo-2,2'-bipyridine, tris(dibenzylideneacetone)dipalladium, triphenylphosphine and cesium carbonate in a fourth solvent, stirring to react, eluting after the reaction is completed, separating and recrystallizing to obtain solid Ni-Por-1, i.e. the porphyrin-based adsorption uranium reduction material, and the structural formula is shown as formula 1.
[0008] Preferably, in the step 1), the molar ratio of 3,5-di-tert-butylbenzaldehyde, pyrrole and trifluoroacetic acid is 1.0: (25.0~38.0): (0.05~0.25); The reaction is carried out under normal temperature and light shielding conditions, and the reaction time is 2~10 min.
[0009] Preferably, in the step 2), the molar ratio of 3,5-di-tert-butylphenyl dipyrromethene, 3,5-di-tert-butylbenzaldehyde, p-bromobenzaldehyde, trifluoroacetic acid, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and the first solvent is 1.0: (0.5~1.5): (0.5~1.5): (0.05~0.25): (0.05~0.25): (0.5~1.5); The molar ratio of 3,5-di-tert-butylphenyldipyrromethane, 3,5-di-tert-butylbenzaldehyde, and p-bromobenzaldehyde is 1.0:(0.35-0.75):(0.25-0.95); The molar ratio of 3,5-di-tert-butylbenzaldehyde and trifluoroacetic acid is 1.0:(0.05-0.25); The molar ratio of 3,5-di-tert-butylbenzaldehyde and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone is 1.0:(0.20-0.50); The first solvent is 1,2-dichloromethane, and the molar ratio of 3,5-di-tert-butylphenyldipyrromethane and 1,2-dichloromethane is 1.0:(800-1300); The reaction is carried out at room temperature under light shielding conditions, and the reaction time is 2-8 h.
[0010] Preferably, in step 3), The second solvent is toluene, and the molar ratio of Por-Br in step 3) and toluene is 1.0:(2000-2800); The molar ratio of Por-Br and nickel acetylacetonate is 1.0:(1.0-3.0); The reaction is carried out in an oil bath, the temperature is between 100-150°C, and the reaction time is 2-8 h.
[0011] Preferably, in step 4), The molar ratio of Ni-Por-Br, bis(pinacolato)diboron, potassium acetate, and (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride is 1.0:(2.55-3.50):(0.8-1.6):(0.014-0.07); The third solvent is 1,4-dioxane, and the molar ratio of Ni-Por-Br and 1,4-dioxane is 1.0:(150-250); The reaction is carried out in an oil bath, the reaction temperature is between 80-150°C, and the reaction time is 12-25 h.
[0012] Preferably, in step 5), The molar ratio of Ni-Por-B, 5-bromo-2,2'-bipyridine, tris(dibenzylideneacetone)dipalladium, phenylphosphine oxide, cesium carbonate, and cesium fluoride is 1.0:(1.0-1.7):(0.03-0.07):(0.1-0.5):(0.8-1.60):(0.7-1.30); The fourth solvent is a mixed solution of toluene and N, N-dimethylformamide, and the molar ratio of the Ni-Por-B, toluene and N, N-dimethylformamide is 1.0: (100-150): (50-150). The reaction is carried out in an oil bath pot, the reaction temperature is 80-150 DEG C, and the reaction time is 30-50 h.
[0013] Preferably, in the steps 1), 2), 4) and 5), the crude product is purified by silica gel column chromatography, and CH2Cl2 and petroleum ether are used as eluents.
[0014] Further preferably, the molar ratio of the CH2Cl2 and the petroleum ether is 1.0: (1.0-5.0).
[0015] The third object of the present application is achieved by the following technical solutions. The present application also provides an application of the above-mentioned oxazoline group adsorbing and reducing uranium material in uranium extraction from seawater.
[0016] Compared with the prior art, the present application has the following beneficial effects: The application also discloses a preparation method of the porphyrin-based adsorption and reduction uranium material, first, Por-Br is prepared through substitution reaction of 3,5-di-tert-butyl benzaldehyde, pyrrole and p-bromobenzaldehyde, then coordination reaction of Por-Br and acetylacetone nickel is carried out to obtain Ni-Por-Br, substitution reaction of Ni-Por-Br and pinacol diboron [(Bpin)2] is carried out to obtain Ni-Por-B, finally, 2,2'-bipyridine groups are introduced on the porphyrin base through Suzuki coupling reaction of Ni-Por-B and 5-bromo-2,2'-bipyridine to obtain red powder Ni-Por-1, the synthesis condition is mild and the operation is simple. The porphyrin has a planar conjugate rigid structure, can provide stable support for the adsorption material, improve the thermodynamic stability, has high flexibility of porphyrin structure modification, can regulate the coordination adsorption capacity of the material through substitution group modification, and the photosensitivity of the porphyrin can endow the material with specific properties such as light response characteristics and antibacterial properties, and can improve the adsorption capacity and the possibility of reducing uranyl ions under the assistance of light. Meanwhile, the 2,2'-bipyridine groups are introduced into the porphyrin skeleton, the two nitrogen atoms of 2,2'-bipyridine as a bidentate ligand (hard Lewis base) can realize bidentate chelation coordination with uranyl ions (hard Lewis acid) like the "bidentate chopsticks head" of chopsticks, so that a stable five-membered ring structure is formed. Moreover, the axial ligand distance between the two nitrogen atoms can perfectly adapt to the linear structure of uranyl ions (O=U=O), specific recognition is realized, and the adsorption stability and selectivity are greatly improved. The macrocyclic conjugate system of the porphyrin can absorb visible light, excite the electrons to jump from the ground state to the excited state, and generate electron-hole pairs, the 2,2'-bipyridine can quickly capture the electrons generated in the excited state of the porphyrin and transfer to the uranyl ions, and the reduction of the uranyl ions is realized through the synergistic mechanism of "light absorption-electron transfer-catalytic reduction". In addition, under the excitation of light, the active oxygen species (ROS) generated by the porphyrin can destroy the bacterial cell membrane, protein and DNA, and the 2,2'-bipyridine can also combine with the phospholipid and protein on the bacterial cell membrane, interfere with the cell membrane permeability, inhibit the metabolic enzyme activity of the bacteria, and the synergistic effect of the two can endow the adsorbent with excellent antibacterial performance, effectively solve the biological pollution problem in the seawater environment, and provide an important reference for the development of a new seawater uranium extraction material.
[0017] The application also discloses the porphyrin-based adsorption and reduction uranium material prepared by the preparation method.
[0018] The application also discloses application of the porphyrin-based adsorption and reduction uranium material in seawater uranium extraction, when the porphyrin-based adsorption and reduction uranium material is applied to seawater uranium extraction, the 2,2'-bipyridine functional group provides good selectivity to uranium, and provides selectivity for the seawater uranium extraction material. BRIEF DESCRIPTION OF DRAWINGS
[0019] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The illustrations, together with their description, serve to explain the application without unduly Figure 1 Synthetic scheme for the porphyrin-based adsorbing-reducing uranium material disclosed in the present application; Figure 2 1H NMR chart for the porphyrin-based adsorbing-reducing uranium material disclosed in the present application; Figure 3 HRMS chart for the porphyrin-based adsorbing-reducing uranium material disclosed in the present application; Figure 4 Synthetic finished product chart for the porphyrin-based adsorbing-reducing uranium material disclosed in the present application; Figure 5 Comparison chart for the porphyrin-based adsorbing-reducing uranium material disclosed in the present application before and after reduction of uranyl ions in the application of adsorbing and reducing uranyl ions; Figure 6 Adsorption capacity chart for the porphyrin-based adsorbing-reducing uranium material disclosed in the present application in 10 ppm uranium solution at different pH; Figure 7 Adsorption curve chart for the porphyrin-based adsorbing-reducing uranium material disclosed in the present application under two conditions (dark state and irradiation). DETAILED DESCRIPTION
[0020] The detailed description particularly refers to various exemplary embodiments of the application, which are illustrative of the various aspects thereof, and are not meant to limit the present application in any way, which can be embodied in various other forms without departing from the spirit of the present application. It is to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting in any way. In addition, it must be understood that, as used in the specification and the appended claims, the singular form of "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Furthermore, it is to be understood that terms such as "about" and "substantially" when used in reference to a particular recited value or a particular recited range of values, are intended to mean that the value or range of values is within a reasonable functional range of the value or range of values.
[0021] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All patents, patent applications, publications, and descriptions mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the patents, patent applications, publications, and descriptions are cited. In case of conflict, the content of the present specification will control.
[0022] Many modifications and variations of the present disclosure described in the specification are possible without departing from the scope or spirit of the present disclosure. Other implementations of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the present disclosure. The specification and examples are illustrative only. As used herein, "comprise", "comprising", "include", "including", "contain", "containing", "have", "having", and the like are open-ended terms that are intended to mean including, but not limited to.
[0023] The method of the present application is further described in the following examples with reference to the accompanying drawings. In the following examples, the instruments and apparatuses used are those of conventional use in the art, and the various materials and reagents used are those of conventional use in the art, or can be prepared or formulated by known methods or from the specifications of the reagents, unless otherwise stated. The experimental procedures in the following examples, where not specified, are generally carried out under conventional conditions, or under the conditions recommended by the manufacturer.
[0024] The present application is further described in detail by reference to the following drawings: Example 1 Step 1 : 3,5-di-tert-butylbenzaldehyde (5.00 g, 22.90 mmol), pyrrole (40 mL, 577.21 mmol) were added to a 250 mL three-necked flask, and N2 was bubbled through the solution. Trifluoroacetic acid (0.10 mL) was added to the three-necked flask, and the reaction was stirred at RT for 3 min under light protection. The reaction was quenched by adding aqueous NaOH solution, and the product was extracted with CH2Cl2after cooling to room temperature. The crude product was purified by column chromatography on silica gel (CH2Cl2 / petroleum ether as eluent) to give 2.58 g, 7.91 mmol, 35% yield.
[0025] Step 2: 3,5-di-tert-butylphenyldipyrromethane (7.62 g, 22.80 mmol), 3,5-di-tert- butylbenzaldehyde (1.73 g, 7.98 mmol), and p-bromobenzaldehyde (1.14 g, 5.70 mmol) were dissolved in CH2Cl2(1.0 L), and N2 was bubbled through the solution. Trifluoroacetic acid (0.1 mL) was added to the three-necked flask, and the reaction was stirred at room temperature for 2 h under light protection. 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (5.17 g, 22.80 mmol) was added, and the mixture was stirred for another 2 h. The solvent was removed, and the crude product was purified by column chromatography on silica gel (CH2Cl2 / petroleum ether as eluent 1 :1 ) and recrystallized to give purple solid Por-Br (0.28 g, 0.27 mmol, 13% yield) Step 3: By adding Por-Br (0.37 g, 0.37 mmol) into a 250 mL round bottom flask with a magnetic stir bar and dissolving in toluene (PhMe) (100 mL), after stirring for 5 min at 25 °C, nickel acetylacetonate (0.95 g, 0.37 mmol) was added, after stirring for 2 h at 100 °C, the product was filtered with a chromatography column packed with alumina to obtain red solid Ni-Por-Br (0.31 g, 0.30 mmol, 82% yield).
[0026] Step 4: By adding Ni-Por-Br (200 mg, 0.183 mmol), bis(pinacolato)diboron ((Bpin)2) (118 mg, 0.466 mmol), potassium acetate (14.36 mg, 0.146 mmol), (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride (Pd(dppf)Cl2) (2.01 mg, 0.0027 mmol) into a dry Schlenk reaction tube, then 3 mL of anhydrous 1,4-dioxane was added into the reaction tube with a syringe under nitrogen protection, the reaction tube was placed in an oil bath pot at 80 °C, and stirred at a constant speed for 12 h, after stopping the reaction, the reaction tube was allowed to cool completely, the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) with chloroform and eluted, after complete elution, rotary evaporation was performed to recover chloroform. The residue was separated by silica gel column chromatography (eluted with dichloromethane / n-hexane 1:1), recrystallized to obtain red solid Ni-Por-B (130 mg, 64%).
[0027] Step 5: By adding Ni-Por-B (500 mg, 0.441 mmol), 5-bromo-2,2'-bipyridine (111.81 mg, 0.441 mmol), tris(dibenzylideneacetone)dipalladium (Pd2(dba)3) (12.13 mg, 0.013 mmol), phenylphosphine oxide (pph3) (11.59 mg, 0.044 mmol), Cs2CO3 (114.66 mg, 0.353 mmol), CsF (48.13 mg, 0.309 mmol) into a dry Schlenk reaction tube, then 6 mL of toluene and 3 mL of N,N-dimethylformamide (DMF) was added into the reaction tube with a syringe under argon protection, the reaction tube was placed in an oil bath pot at 80 °C, and stirred at a constant speed for 30 h. After stopping the reaction, the reaction tube was allowed to cool completely, the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) with dichloromethane and eluted, after complete elution, rotary evaporation was performed. The residue was separated by silica gel column chromatography (eluted with dichloromethane / petroleum ether 1:1), recrystallized to obtain red solid Ni-Por-1 (330 mg, 71%).
[0028] The yields of 3,5-di-tert-butylphenyl dipyrromethene, Por-Br, Ni-Por-Br, Ni-Por-B, Ni-Por-1 were determined to be 35, 13%, 82%, 64%, 71%, respectively.
[0029] Example 2 Step 1: 3,5-di-tert-butylbenzaldehyde (5.00 g, 22.90 mmol), pyrrole (40 mL, 577.21 mmol) were added to a 250 mL three-necked flask, and N2 was bubbled through the solution. 0.20 mL trifluoroacetic acid was added to the three-necked flask, and the reaction was stirred at RT for 3 min under light shielding. The product was extracted with CH2Cl2, washed, and purified by silica gel column chromatography (CH2Cl2 / petroleum ether as eluent) to obtain 2.62 g, 8.21 mmol, with a yield of 37%.
[0030] Step 2: 3,5-di-tert-butylphenyl dipyrromethene (7.62 g, 22.80 mmol), 3,5-di-tert- butylbenzaldehyde (1.73 g, 7.98 mmol), and p-bromobenzaldehyde (1.60 g, 7.98 mmol) were dissolved in CH2Cl2(1.0 L), and N2 was bubbled through the solution. Trifluoroacetic acid (0.1 mL) was added to the three-necked flask, and the reaction was stirred at room temperature for 3 h under light shielding. 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (5.17 g, 22.80 mmol) was added, and the mixture was stirred for another 4 h. The solvent was removed, and the crude product was purified by silica gel column chromatography (CH2Cl2 / petroleum ether as eluent 1:1) and recrystallized to obtain purple solid Por-Br (0.29 g, 0.30 mmol, 15% yield).
[0031] Step 3: Por-Br (0.37 g, 0.37 mmol) was added to a 250 mL round-bottom flask with a magnetic stirring bar and dissolved in toluene (100 mL), and after stirring at 25 °C for 5 min, nickel acetylacetonate (0.95 g, 0.37 mmol) was added. After stirring at 110 °C for 4 h, the product was filtered with a chromatography column packed with alumina to obtain red solid Ni-Por-Br (0.31 g, 0.30 mmol, 85% yield).
[0032] Step 4: By adding Ni-Por-Br (200 mg, 0.183 mmol), (Bpin)2(118 mg, 0.466 mmol), potassium acetate (14.36 mg, 0.146 mmol), Pd(dppf)Cl2(2.01 mg, 0.0027 mmol) into a dry Schlenk reaction tube, then 3 mL of anhydrous 1,4-dioxane was added into the reaction tube under nitrogen protection, the reaction tube was placed in an oil bath at 100 °C, and stirred at a constant speed for 15 h. After the reaction was stopped, the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) with chloroform and eluted. After elution was complete, rotary evaporation was performed, and chloroform was recovered. The residue was separated by silica gel column chromatography (eluted with dichloromethane / n-hexane 1:1), and recrystallized to obtain red solid Ni-Por-B (140 mg, 68%).
[0033] Step 5: By adding Ni-Por-B (500 mg, 0.441 mmol), 5-bromo-2,2'-bipyridine (134.12 mg, 0.529 mmol), Pd2(dba)3(16.80 mg, 0.018 mmol), pph3(23.17 mg, 0.088 mmol), Cs2CO3(129.00 mg, 0.397 mmol), CsF (54.98 mg, 0.353 mmol) into a dry Schlenk reaction tube, then 6 mL of toluene and 3 mL of DMF were added into the reaction tube under argon protection, the reaction tube was placed in an oil bath at 90 °C, and stirred at a constant speed for 40 h. After the reaction was stopped, the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) with dichloromethane and eluted. After elution was complete, rotary evaporation was performed. The residue was separated by silica gel column chromatography (eluted with dichloromethane / petroleum ether 1:1), and recrystallized to obtain red solid Ni-Por-1 (340 mg, 73%).
[0034] The yield of 3,5-di-tert-butylphenyldipyrrolo, Por-Br, Ni-PorBr, Ni-Por-B, Ni-Por-1 obtained in this example was determined to be 37%, 15%, 85%, 68%, 73%.
[0035] Example 3 Step 1 : 3,5-di-tert-butylbenzaldehyde (5.00 g, 22.90 mmol), pyrrole (50 mL, 732.80 mmol) were added in a 250 mL three-necked flask, N2 was bubbled through the solution. 0.30 mL trifluoroacetic acid was added in the three-necked flask, the reaction was stirred at RT for 3 min under light protection. The reaction was quenched with aqueous NaOH solution, after cooling to room temperature, the product was extracted with CH2Cl2, washed, the crude was purified by silica gel column chromatography (CH2Cl2 / petroleum ether as eluent), 2.51 g, 8.02 mmol, 36% yield was obtained.
[0036] Step 2: 3,5-di-tert-butylphenyldipyrromethane (7.62 g, 22.80 mmol), 3,5-di-tert- butylbenzaldehyde (1.73 g, 7.98 mmol) and p-bromobenzaldehyde (1.60 g, 7.98 mmol) were dissolved in CH2Cl2(1.0 L), N2 was bubbled through the solution. Trifluoroacetic acid (0.1 mL) was added in the three-necked flask, and the reaction was stirred at room temperature for 3 h under light protection. 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (5.17 g, 22.80 mmol) was added, and the mixture was stirred for another 6 h. The solvent was removed, and the crude product was purified by silica gel column chromatography (CH2Cl2 / petroleum ether as eluent 1:2), recrystallization, purple solid Por-Br (0.30 g, 0.31 mmol, 16% yield) was obtained.
[0037] Step 3: Por-Br (0.37 g, 0.37 mmol) was added to a 250 mL round-bottom flask with a magnetic stir bar and dissolved in toluene (100 mL), after stirring at 25 °C for 5 min, nickel acetylacetonate (0.95 g, 0.37 mmol) was added, after stirring at 115 °C for 4 h, the product was filtered with a chromatography column packed with alumina, red solid Ni-Por-Br (0.32 g, 0.31 mmol, 86% yield) was obtained.
[0038] Step 4: By adding Ni-Por-Br (200 mg, 0.183 mmol), (Bpin)2(140 mg, 0.549 mmol), potassium acetate (18.00 mg, 0.183 mmol), Pd(dppf)Cl2(5.43 mg, 0.0073 mmol) to a dry Schlenk reaction tube, then 3 mL of anhydrous 1,4-dioxane was added to the reaction tube under nitrogen protection, the reaction tube was placed in an oil bath at 105 °C, and stirred at a constant speed for 16 h. After stopping the reaction, the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) with chloroform and eluted. After complete elution, rotary evaporation was performed to recover chloroform. The residue was separated by silica gel column chromatography (eluted with dichloromethane / n-hexane 1:1), recrystallized to obtain red solid Ni-Por-B (145 mg, 69%).
[0039] Step 5: By adding Ni-Por-B (500 mg, 0.441 mmol), 5-bromo-2,2'-bipyridine (142.50 mg, 0.562 mmol), Pd2(dba)3(20.53 mg, 0.022 mmol), pph3(34.76 mg, 0.132 mmol), Cs2CO3(143.24 mg, 0.441 mmol), CsF (61.83 mg, 0.397 mmol) to a dry Schlenk reaction tube, then 6 mL of toluene and 3 mL of DMF were added to the reaction tube under argon protection with a syringe, and the reaction tube was placed in an oil bath at 100 °C, and stirred at a constant speed for 42 h. After stopping the reaction, the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) with dichloromethane and eluted. After complete elution, rotary evaporation was performed. The residue was separated by silica gel column chromatography (eluted with dichloromethane / petroleum ether 1:2), recrystallized to obtain red solid Ni-Por-1 (345 mg, 75%).
[0040] The yield of 3,5-di-tert-butylphenyl porphyrin, Por-Br, Ni-PorBr, Ni-Por-B, Ni-Por-1 obtained in this example was determined to be 36%, 16%, 86%, 69%, 75%.
[0041] Example 4 Step 1 : 3,5-di-tert-butylbenzaldehyde (5.00 g, 22.90 mmol), pyrrole (55 mL, 801.5 mmol) were added in a 250 mL three-necked flask, N2 was bubbled through the solution. 0.20 mL trifluoroacetic acid was added in the three-necked flask, the reaction was stirred at RT for 5 min under light protection. The reaction was quenched with an aqueous solution of sodium hydroxide, after cooling to room temperature, the product was extracted with CH2Cl2, washed, the crude was purified by column chromatography on silica gel (CH2Cl2 / petroleum ether as eluent), 2.62 g, 8.56 mmol, 38% yield was obtained.
[0042] Step 2: 3,5-di-tert-butylphenyldipyrromethane (7.62 g, 22.80 mmol), 3,5-di-tert- butylbenzaldehyde (24.85 g, 11.4 mmol) and p-bromobenzaldehyde (2.11 g, 11.4 mmol) were dissolved in CH2Cl2(1.0 L), N2 was bubbled through the solution. Trifluoroacetic acid (0.2 mL) was added in the three-necked flask, and the reaction was stirred at room temperature for 4 h under light protection. 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (5.17 g, 22.80 mmol) was added, and the mixture was stirred for another 6 h. The solvent was removed, and the crude product was purified by column chromatography on silica gel (CH2Cl2 / petroleum ether as eluent 1 :2), recrystallized to obtain purple solid Por-Br (0.32 g, 0.33 mmol, 17% yield).
[0043] Step 3: Por-Br (0.37 g, 0.37 mmol) was added to a 250 mL round-bottom flask with a magnetic stir bar, and dissolved in toluene (150 mL), after stirring at 25 °C for 5 min, nickel acetylacetonate (1.90 g, 0.74 mmol) was added, after stirring at 120 °C for 4 h, the product was filtered with a column packed with alumina, red solid Ni-Por-Br (0.34 g, 0.32 mmol, 88% yield) was obtained.
[0044] Step 4: By adding Ni-Por-Br (200 mg, 0.183 mmol), (Bpin)2 (118 mg, 0.466 mmol), potassium acetate (14.36 mg, 0.146 mmol), Pd(dppf)Cl2 (2.01 mg, 0.0027 mmol) to a dry Schlenk reaction tube, then 3 mL of anhydrous 1,4-dioxane was added to the reaction tube under nitrogen protection, the reaction tube was placed in an oil bath at 115 °C, and stirred at a constant speed for 20 h. After stopping the reaction, the reaction tube was completely cooled, and the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) and eluted with chloroform. After complete elution, rotary evaporation was performed, and chloroform was recovered. The residue was separated by silica gel column chromatography (eluted with dichloromethane / n-hexane 1:1), and recrystallized to obtain red solid Ni-Por-B (147 mg, 70%).
[0045] Step 5: By adding Ni-Por-B (500 mg, 0.441 mmol), 5-bromo-2,2'-bipyridine (142.49 mg, 0.562 mmol), Pd2(dba)3 (20.53 mg, 0.022 mmol), pph3 (34.56 mg, 0.132 mmol), Cs2CO3 (171.83 mg, 0.529 mmol), CsF (68.68 mg, 0.441 mmol) to a dry Schlenk reaction tube, then 6 mL of toluene and 3 mL of DMF were added to the reaction tube under argon protection, and the reaction tube was placed in an oil bath at 120 °C, and stirred at a constant speed for 46 h. After stopping the reaction, the reaction tube was completely cooled, and the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) and eluted with dichloromethane / petroleum ether 1:2. After complete elution, rotary evaporation was performed. The residue was separated by silica gel column chromatography (eluted with dichloromethane / petroleum ether 1:2), and recrystallized to obtain red solid Ni-Por-1 (352 mg, 76%).
[0046] The yield of 3,5-di-tert-butylphenyldipyrrolo, Por-Br, Ni-PorBr, Ni-Por-B, Ni-Por-1 obtained in this example was determined to be 38%, 17%, 88%, 70%, and 76%, respectively.
[0047] Example 5 Step 1 : 3,5-di-tert-butylbenzaldehyde (5.00 g, 22.90 mmol), pyrrole (60 mL, 865.23 mmol) were added in a 250 mL three-necked flask, N2 was bubbled through the solution. 0.20 mL trifluoroacetic acid was added in the three-necked flask, the reaction was stirred at RT for 5 min under light protection. The reaction was quenched with aqueous NaOH solution, after cooling to room temperature, the product was extracted with CH2Cl2, washed, the crude was purified by silica gel column chromatography (CH2Cl2 / petroleum ether as eluent), 2.62 g, 8.56 mmol, 38% yield was obtained.
[0048] Step 2: 3,5-di-tert-butylphenyldipyrromethane (7.62 g, 22.80 mmol), 3,5-di-tert- butylbenzaldehyde (24.85 g, 11.4 mmol) and p-bromobenzaldehyde (2.11 g, 11.4 mmol) were dissolved in CH2Cl2(1.5 L), N2 was bubbled through the solution. Trifluoroacetic acid (0.2 mL) was added in the three-necked flask, and the reaction was stirred at room temperature for 4 h under light protection. 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (7.76 g, 34.2 mmol) was added, and the mixture was stirred for another 6 h. The solvent was removed, and the crude product was purified by silica gel column chromatography (CH2Cl2 / petroleum ether as eluent 1 :3), recrystallized to obtain purple solid Por-Br (0.34 g, 0.33 mmol, 18% yield).
[0049] Step 3: Por-Br (0.37 g, 0.37 mmol) was added to a 250 mL round-bottom flask with a magnetic stir bar, and dissolved in toluene (150 mL), after stirring at 25 °C for 5 min, acetylacetonatonickel (1.90 g, 0.74 mmol) was added, after stirring at 130 °C for 6 h, the product was filtered with a chromatography column packed with alumina, red solid Ni-Por-Br (0.35 g, 0.33 mmol, 90% yield) was obtained.
[0050] Step 4: By adding Ni-Por-Br (200 mg, 0.183 mmol), (Bpin)2 (140 mg, 0.552 mmol), potassium acetate (18.09 mg, 0.184 mmol), Pd(dppf)Cl2 (6.73 mg, 0.009 mmol) into a dry Schlenk reaction tube, then 3 mL of anhydrous 1,4-dioxane was added into the reaction tube under nitrogen protection, the reaction tube was placed in an oil bath pot at 125 °C, and stirred uniformly for 23 h. After stopping the reaction, the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) with chloroform and eluted. After elution was complete, rotary evaporation was performed, and chloroform was recovered. The residue was separated by silica gel column chromatography (eluted with dichloromethane / n-hexane 1:1), and recrystallized to obtain red solid Ni-Por-B (150 mg, 75%).
[0051] Step 5: By adding Ni-Por-B (500 mg, 0.441 mmol), 5-bromo-2,2'-bipyridine (154.67 mg, 0.661 mmol), Pd2(dba)3 (23.85 mg, 0.026 mmol), pph3 (46.24 mg, 0.176 mmol), Cs2CO3 (200.51 mg, 0.617 mmol), CsF (80.35 mg, 0.529 mmol) into a dry Schlenk reaction tube, then 6 mL of toluene and 3 mL of DMF were added into the reaction tube under argon protection, the reaction tube was placed in an oil bath pot at 135 °C, and stirred uniformly for 48 h. After stopping the reaction, the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) with dichloromethane and eluted. After elution was complete, rotary evaporation was performed. The residue was separated by silica gel column chromatography (eluted with dichloromethane / petroleum ether 1:2), and recrystallized to obtain red solid Ni-Por-1 (360 mg, 78%).
[0052] The yield of 3,5-di-tert-butylphenyl porphyrin, Por-Br, Ni-PorBr, Ni-Por-B, Ni-Por-1 obtained in this example was determined to be 38%, 18%, 90%, 75%, and 78%, respectively.
[0053] Example 6 Step 1 : 3,5-di-tert-butylbenzaldehyde (5.00 g, 22.90 mmol), pyrrole 2 (60 mL, 865.23 mmol) were added in a 250 mL three-necked flask, N2 was bubbled through the solution. 0.30 mL trifluoroacetic acid was added in the three-necked flask, the reaction was stirred at RT for 10 min under light protection. The reaction was quenched with aqueous sodium hydroxide solution, after cooling to room temperature, the product was extracted with CH2Cl2, washed, the crude was purified by column chromatography on silica gel (CH2Cl2 / petroleum ether as eluent), 2.41 g, 7.66 mmol, 32% yield was obtained.
[0054] Step 2: 3,5-di-tert-butylphenyldipyrrin (7.62 g, 22.80 mmol), 3,5-di-tert- butylbenzaldehyde (37.28 g, 17.1 mmol) and p-bromobenzaldehyde (4.00 g, 21.66 mmol) were dissolved in CH2Cl2(1.5 L), N2 was bubbled through the solution. Trifluoroacetic acid (0.3 mL) was added in the three-necked flask, and the reaction was stirred at room temperature for 4 h under light protection. 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (7.76 g, 34.2 mmol) was added, and the mixture was stirred for another 8 h. The solvent was removed, and the crude product was purified by column chromatography on silica gel (CH2Cl2 / petroleum ether as eluent 1 :4), recrystallized to obtain purple solid Por-Br (0.31 g, 0.32 mmol, 16% yield).
[0055] Step 3: Por-Br (0.37 g, 0.37 mmol) was added to a 250 mL round-bottom flask with a magnetic stir bar, and dissolved in toluene (150 mL), after stirring at 25 °C for 5 min, acetylacetonatonickel (2.85 g, 1.11 mmol) was added, after stirring at 150 °C for 8 h, the product was filtered with a column packed with alumina, red solid Ni-Por-Br (0.33 g, 0.31 mmol, 87% yield) was obtained.
[0056] Step 4: By adding Ni-Por-Br (200 mg, 0.183 mmol), (Bpin)2 (163 mg, 0.641 mmol), potassium acetate (28.81 mg, 0.293 mmol), Pd(dppf)Cl2 (9.72 mg, 0.013 mmol) into a dry Schlenk reaction tube, then 3 mL of anhydrous 1,4-dioxane was added into the reaction tube under nitrogen protection, the reaction tube was placed in an oil bath at 150 °C, and stirred at a constant speed for 25 h. After the reaction was stopped, the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) with chloroform and eluted. After complete elution, rotary evaporation was performed to recover chloroform. The residue was separated by silica gel column chromatography (eluted with dichloromethane / n-hexane 1:2), and recrystallized to obtain red solid Ni-Por-B (146 mg, 73%).
[0057] Step 5: By adding Ni-Por-B (500 mg, 0.441 mmol), 5-bromo-2,2'-bipyridine (175.50 mg, 0.750 mmol), Pd2(dba)3 (28.44 mg, 0.031 mmol), pph3 (57.81 mg, 0.220 mmol), Cs2CO3 (229.46 mg, 0.706 mmol), CsF (87.03 mg, 0.573 mmol) into a dry Schlenk reaction tube, then 6 mL of toluene and 3 mL of DMF were added into the reaction tube under argon protection, the reaction tube was placed in an oil bath at 150 °C, and stirred at a constant speed for 50 h. After the reaction was stopped, the reaction mixture was transferred to a prepared short silica gel column (length 5 cm, inner diameter 2 cm) with dichloromethane and eluted. After complete elution, rotary evaporation was performed. The residue was separated by silica gel column chromatography (eluted with dichloromethane / petroleum ether 1:3), and recrystallized to obtain red solid Ni-Por-1 (354 mg, 76%). The yield of 3,5-di-tert-butylphenyldipyrrolo, Por-Br, Ni-PorBr, Ni-Por-B, Ni-Por-1 obtained in this example was determined to be 32%, 16%, 87%, 73%, and 76%, respectively.
[0058] From the analysis of Examples 1-6, under the conditions of changing the reaction temperature, ratio and reaction time, the yield of 3,5-di-tert-butylphenyldipyrrolo, Por-Br, Ni-PorBr, Ni-Por-B, Ni-Por-1 obtained was determined to be 38%, 18%, 90%, 75%, and 78%, respectively.
[0059] Compared with the prior art, the raw material of the application is easy to obtain, and the condition is mild, and the application is more popular. The material ratio and process of the above-mentioned embodiment 5 are the best technical scheme of the application.
[0060] Referring to Figure 1 The synthesis route chart of the porphyrin-based adsorption and reduction uranium material disclosed in the application is shown in the figure. As can be seen from the figure, Por-Br is prepared through substitution reaction of 3, 5-di-tert-butylbenzaldehyde, pyrrole and p-bromobenzaldehyde, then Ni-Por-Br is obtained through coordination reaction of Por-Br and acetylacetone nickel, Ni-Por-Br is obtained through substitution reaction of Ni-Por-Br and boronic acid pinacol [(Bpin)2], finally, 2, 2'-bipyridine groups are introduced on the porphyrin base through Suzuki coupling reaction of Ni-Por-B and 5-bromo-2, 2'-bipyridine, and red powder Ni-Por-1 is obtained.
[0061] Referring to Figure 2 The H RMS chart of the porphyrin-based adsorption and reduction uranium material disclosed in the application is shown in the figure. 1 The H NMR chart shows that Ni-Por-1 is successfully synthesized.
[0062] Referring to Figure 3 The H RMS chart of the porphyrin-based adsorption and reduction uranium material disclosed in the application is shown in the figure. + Calcd for C 78 H 82 N6Ni 1162.3020;Found 1162.3024.
[0063] Referring to Figure 4 The synthesis finished product chart of the porphyrin-based adsorption and reduction uranium material disclosed in the application is shown in the figure, and it can be seen from the figure that Ni-Por-1 is a red powder.
[0064] Referring to Figure 5 The comparison chart of the porphyrin-based adsorption and reduction uranium material disclosed in the application before (right bottle) and after (left bottle) adsorption and reduction of uranyl ions in the application of adsorbing and reducing uranyl ions is shown in the figure, and it can be seen from the figure that in the adsorption and reduction experiment of uranyl ions, UO2 2+ is reduced to UO2 precipitate.
[0065] Referring to Figure 6 The adsorption capacity chart of the porphyrin-based adsorption and reduction uranium material disclosed in the application in 10 ppm uranium solution at different pH values is shown in the figure, and it can be seen from the figure that the optimal pH value of Ni-Por-1 is 6, and the adsorption capacity reaches 198.56 mg / g.
[0066] Referring to Figure 7The adsorption curve of the porphyrin-based adsorption reduction uranium material disclosed in the application under two conditions (dark state and irradiation) is shown in the figure, and it can be seen from the figure that the adsorption equilibrium time under the irradiation condition is shortened from 120 min under the dark state to 60 min, and the adsorption capacity at the equilibrium time is increased from 193 mg·g -1 to 239 mg·g -1 .
[0067] The above is only a preferred specific embodiment of the application, but the protection scope of the application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the application, which should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.
Claims
1. A porphyrin-based adsorption and reduction material for uranium, characterized in that, The structural formula is shown in Equation 1: 。 2. The method for preparing the porphyrin-based adsorption-reduction uranium material according to claim 1, characterized in that, Includes the following steps: 1) Mix 3,5-di-tert-butylbenzaldehyde and pyrrole evenly, bubble nitrogen through the solution, add trifluoroacetic acid as a catalyst, stir the reaction, quench the reaction after it is completed, cool, wash with water, dry and purify to obtain 3,5-di-tert-butylphenyl dipyrrole; 2) 3,5-di-tert-butylphenyl dipyrrole, 3,5-di-tert-butylbenzaldehyde and p-bromobenzaldehyde were mixed and uniformly dispersed in the first solvent by bubbling nitrogen gas through the solution. Trifluoroacetic acid was added as a catalyst and the reaction was stirred. Then 2,3-dichloro-5,6-dicyano-1,4-benzoquinone was added. After the reaction was completed, the solvent was removed, the solution was purified, and Por-Br was obtained by recrystallization. 3) Stir Por-Br evenly dispersed in the second solvent, add nickel acetylacetone and stir to react. After the reaction is complete, filter and recrystallize to obtain solid Ni-Por-Br; 4) Ni-Por-Br, pinacol diborate, potassium acetate, and (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride were mixed and stirred evenly in a third solvent. The reaction was stirred and then eluted, separated, and recrystallized to obtain solid Ni-Por-B. 5) Ni-Por-B, 5-bromo-2,2'-bipyridine, tris(dibenzylideneacetone)palladium, triphenylphosphine oxide, cesium carbonate, and cesium fluoride were mixed and stirred evenly in a fourth solvent. After stirring and reacting, the mixture was cooled, eluted, separated, and recrystallized to obtain solid Ni-Por-1, which is the porphyrin-based adsorbent-reduced uranium material.
3. The method for preparing porphyrin-based adsorption-reduction uranium material according to claim 2, characterized in that, In step 1), the molar ratio of 3,5-di-tert-butylbenzaldehyde to pyrrole is 1.0:(25.0~38.0); the molar ratio of 3,5-di-tert-butylbenzaldehyde to trifluoroacetic acid is 1.0:(0.05~0.25). The reaction was carried out at room temperature under light-proof conditions for 2 to 10 minutes.
4. The method for preparing porphyrin-based adsorption-reduced uranium material according to claim 2, characterized in that, In step 2): The molar ratio of 3,5-di-tert-butylphenyl dipyrrole, 3,5-di-tert-butylbenzaldehyde, and p-bromobenzaldehyde is 1.0:(0.35~0.75):(0.25~0.95). The molar ratio of 3,5-di-tert-butylbenzaldehyde to trifluoroacetic acid is 1.0:(0.05~0.25). The molar ratio of 3,5-di-tert-butylbenzaldehyde to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone is 1.0:(0.20~0.50). The first solvent is 1,2-dichloromethane, and the molar ratio of 3,5-di-tert-butylphenyl dipyrrole to 1,2-dichloromethane is 1.0:(800~1300). The reaction was carried out at room temperature under light-proof conditions for 2–8 hours.
5. The method for preparing porphyrin-based adsorption-reduction uranium material according to claim 2, characterized in that, In step 3): The second solvent is toluene, and the molar ratio of Por-Br to toluene in step 3) is 1.0:(2000~2800). The molar ratio of Por-Br to nickel acetylacetone is 1.0:(1.0~3.0). The reaction is carried out in an oil bath at a temperature between 100 and 150°C for 2 to 8 hours.
6. The method for preparing porphyrin-based adsorption-reduced uranium material according to claim 2, characterized in that, In step 4): The molar ratio of Ni-Por-Br, pinacol diborate, potassium acetate, and (1,1'-bis(diphenylphosphine)ferrocene)palladium dichloride is 1.0:(2.55~3.50):(0.8~1.6):(0.014~0.07). The third solvent is 1,4-dioxane, and the molar ratio of Ni-Por-Br to 1,4-dioxane is 1.0:(150~250). The reaction is carried out in an oil bath at a temperature between 80 and 150°C for 12 to 25 hours.
7. The method for preparing porphyrin-based adsorption-reduced uranium material according to claim 2, characterized in that, In step 5), The molar ratio of Ni-Por-B, 5-bromo-2,2'-bipyridine, tris(dibenzylacetone)palladium, phenylphosphine oxide, cesium carbonate, and cesium fluoride is 1.0:(1.0~1.7):(0.03~0.07):(0.1~0.5):(0.8~1.60):(0.7~1.30). The fourth solvent is a mixed solution of toluene and N,N-dimethylformamide, and the molar ratio of Ni-Por-B, toluene and N,N-dimethylformamide is 1.0:(100~150):(50~150). The reaction is carried out in an oil bath at a temperature of 80-150°C for 30-50 hours.
8. The method for preparing porphyrin-based adsorption-reduced uranium material according to claim 2, characterized in that, In steps 1), 2), 4), and 5), the crude product is purified by silica gel column chromatography, using CH2Cl2 and petroleum ether as eluents.
9. The method for preparing porphyrin-based adsorption-reduced uranium material according to claim 8, characterized in that, The molar ratio of CH2Cl2 to petroleum ether is 1.0:(1.0~5.0).
10. The application of the porphyrin-based adsorption-reduced uranium material according to claim 1 in uranium extraction from seawater.