A method using N(BzBnme2) - Ionic liquid-modified metal-organic framework UiO-66-NH2 pickering emulsion, its preparation method and application
By modifying the metal-organic framework UiO-66-NH2 with N(BzBnme2)- ionic liquid to prepare Pickering emulsion, the problems of difficult separation and poor cycling performance of ionic liquid were solved, and efficient catalysis and catalyst stability of aldehyde-amine condensation reaction were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- LIAONING UNIVERSITY
- Filing Date
- 2026-03-06
- Publication Date
- 2026-06-12
AI Technical Summary
Existing ionic liquids suffer from problems such as difficult separation, complex purification, and poor recyclability in catalytic applications, and traditional porous materials have shortcomings in terms of catalytic efficiency and stability.
The metal-organic framework UiO-66-NH2 modified with N(BzBnme2)- ionic liquid was used to prepare Pickering emulsion. The porous structure of UiO-66-NH2 and the synergistic catalytic effect of Zr4+ and OAc- formed a stable Pickering emulsion system, increasing the contact area between the catalyst and the substrate.
It achieves highly efficient catalysis of aldehyde-amine condensation reaction. The catalyst maintains high activity and stability after multiple cycles and has good separation and recovery performance.
Smart Images
Figure CN122188170A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalytic synthesis technology, specifically relating to a method using N(BzBnme2) - Ionic liquid-modified metal-organic framework UiO-66-NH2 pickering emulsion, its preparation method and application. Background Technology
[0002] Ionic liquids (ILs) are a class of novel materials that are typically liquid at low temperatures. They consist of large organic cations and inorganic or organic anions. Compared to traditional organic solvents, ILs are more environmentally friendly to prepare, and due to their extremely low vapor pressure, they can replace solvents for volatile organic compounds, thus being considered "green solvents." Furthermore, based on their unique interionic interactions, ILs exhibit good compatibility with a variety of polar and nonpolar organic and inorganic compounds and can perform catalytic activities. Despite these excellent properties, ILs still face challenges in practical applications, such as difficult separation, complex purification, and poor recyclability, which limits their large-scale application to some extent. In contrast, heterogeneous catalysts have significant advantages in separation and reuse. Therefore, immobilizing ILs on supports to construct heterogeneous catalytic systems has become one of the effective strategies to improve their practicality. Metal-organic frameworks (MOFs) are a class of crystalline porous materials formed by the self-assembly of metal ions and organic ligands, characterized by high specific surface area, tunable pore structure, low density, and high porosity. Compared to traditional porous materials, MOFs allow for flexible control over the crystal structure and chemical composition of materials by selecting different metal nodes and organic linkers. Introducing ILs into MOF supports not only retains the excellent properties of ILs but also endows the system with the advantages of easy separation and recovery of heterogeneous catalysts, thus demonstrating broad potential in various catalytic and separation applications.
[0003] Pickering emulsions are a class of emulsion systems formed by solid particles (rather than traditional surfactants) as stabilizers. Their stabilization mechanism stems from the adsorption of solid particles at the oil / water interface, preventing droplet coalescence by reducing the interphase interface. The hydrophilicity or hydrophobicity of the particles is a key factor determining the emulsion type, i.e., water-in-oil (O / W) or oil-in-water (W / O) emulsions. Pickering interfacial catalysis refers to the solid particles simultaneously acting as emulsifiers and catalysts, significantly improving mass transfer and catalytic efficiency while forming a stable emulsion due to their large interfacial contact area.
[0004] Imines are important functional groups in medicinal chemistry, widely found in antibacterial agents, antimalarial drugs, and antifungal drugs. They are also important intermediates in the synthesis of other amine organic compounds. By selecting UiO-66-NH2 containing an amino functional group and ILs containing aldehyde groups, the ILs were immobilized on UiO-66-NH2 via a branching process, resulting in a N(BzBnme2)Br-modified composite material used for catalytic aldehyde-amine condensation to prepare imines. Summary of the Invention
[0005] The purpose of this invention is to provide a method based on N(BzBnme2) - Ionic liquid-modified metal-organic framework UiO-66-NH2 was used to prepare pickering emulsions for efficient catalysis of aldehyde-amine condensation.
[0006] The technical solution adopted in this invention is:
[0007] A method using N(BzBnme2) - An ionic liquid-modified metal-organic framework UiO-66-NH2 picklerin emulsion, wherein the picklerin emulsion is a UiO-66-N(Bnme)2OAc picklerin emulsion, which is a picklerin emulsion prepared using UiO-66-N(Bnme)2OAc as an emulsifier.
[0008] A method using N(BzBnme2) - The preparation method of the ionic liquid-modified metal-organic framework UiO-66-NH2 pickering emulsion includes the following steps:
[0009] 1) Disperse ZrCl4 and 2-aminoterephthalic acid in a mixture of DMF and glacial acetic acid, stir evenly, and then put it into a reaction vessel for hydrothermal reaction. After the reaction is completed, cool naturally to room temperature, wash with DMF and ethanol in sequence, and dry under vacuum to obtain UiO-66-NH2.
[0010] 2) Benzyl bromide and 4-dimethylaminobenzaldehyde were dispersed in acetonitrile, stirred, washed with diethyl ether, and dried under vacuum to obtain N(BzBnme2)Br;
[0011] 3) Disperse the UiO-66-NH2 obtained in step 1) and the N(BzBnme2)Br obtained in step 2) into methanol, stir, wash with diethyl ether, and dry under vacuum to obtain UiO-66-N(Bnme)2Br;
[0012] 4) Disperse the UiO-66-N(Bnme)2Br and potassium acetate obtained in step 3) into methanol, stir, wash with water and methanol successively, and dry under vacuum to obtain UiO-66-N(Bnme)2OAc;
[0013] 5) Add toluene and water to the UiO-66-N(Bnme)2OAc obtained in step 4), sonicate, and shake by hand three times to obtain UiO-66-N(Bnme)2OAc Picklein emulsion.
[0014] Furthermore, in the above preparation method, in step 1), the molar ratio of ZrCl4:2-aminoterephthalic acid is 1:1.
[0015] Furthermore, in the above preparation method, in step 1), the volume ratio of glacial acetic acid to DMF in the mixture of DMF and glacial acetic acid is 1:4.3.
[0016] Furthermore, in the above preparation method, in step 1), the stirring time is 30 min.
[0017] Furthermore, in the above preparation method, step 1), the hydrothermal reaction conditions are: 393 K hydrothermal reaction for 24 h.
[0018] Furthermore, in the above preparation method, step 2), the molar ratio of benzyl bromo:4-dimethylaminobenzaldehyde is 1:1; the volume of acetonitrile is 15 mL.
[0019] Furthermore, in the above preparation method, step 2), the stirring conditions are: stirring at 298 K for 48 h.
[0020] Furthermore, in the above preparation method, in step 3), the mass of UiO-66-NH2 is 531 mg, the mass of N(BzBnme2)Br is 384 mg, and the volume of methanol is 60 mL.
[0021] Furthermore, in the above preparation method, step 3), the stirring conditions are: stirring at 298 K for 24 h.
[0022] Furthermore, in the above preparation method, in step 4), the mass of UiO-66-N(Bnme)2Br is 850 mg, the mass of potassium acetate is 200 mg, and the volume of methanol is 80 mL.
[0023] Furthermore, in the above preparation method, step 4), the stirring conditions are: stirring at 298 K for 12 h.
[0024] Furthermore, in the above preparation method, in step 5), the mass of UiO-66-N(Bnme)2OAc is 35 mg, and the volumes of toluene and water are 2 mL and 3 mL, respectively.
[0025] The above-mentioned method uses N(BzBnme2) -Application of ionic liquid-modified metal-organic framework UiO-66-NH2 pickering emulsion in catalytic aldehyde-amine condensation reaction.
[0026] Furthermore, the above application method is as follows: Benzaldehyde and aniline are added to UiO-66-N(Bnme)2OAc Pickering emulsion and reacted at 333 K for 1 h.
[0027] In the UiO-66-N(Bnme)2OAc Pickering emulsion of the present invention, the metal center Zr of the metal-organic framework 4+ It is a Lewis acid site, OAc in ionic liquids. - These are base sites, and the two work together to catalyze the aldehyde-amine condensation reaction. The reaction equation is as follows:
[0028]
[0029] The beneficial effects of this invention are: This invention selects UiO-66-NH2 with a porous structure and good stability, grows an ionic liquid through aldehyde-amine condensation, and then forms a composite material UiO-66-N(Bnme)2OAc modified with the ionic liquid through anion exchange. In this invention, Zr in UiO-66-NH2... 4+ As a Lewis acid, it can reduce the electron density of the carbonyl oxygen, making it more susceptible to attack by amino groups and lowering the activation energy of nucleophilic reactions; while OAc - By abstracting a proton from the amino group of aniline, its nucleophilic ability to attack the carbonyl group is enhanced, and the two synergistically catalyze the aldehyde-amine condensation reaction. In this invention, UiO-66-N(Bnme)2OAc is dispersed in an emulsion system, which greatly increases the contact area between the substrate and the catalyst, thereby improving catalytic efficiency. Furthermore, after five cycles, UiO-66-N(Bnme)2OAc maintains high catalytic activity, exhibiting high stability and recyclability. The UiO-66-N(Bnme)2OAc of this invention demonstrates excellent catalytic performance in aldehyde-amine condensation. Attached Figure Description
[0030] Figure 1 This is an optical microscope image of the UiO-66-N(Bnme)2OAc Picklerin emulsion of the present invention.
[0031] Figure 2 This is the PXRD pattern of the UiO-66-N(Bnme)2OAc material of the present invention.
[0032] Figure 3 This is the FT-IR image of the UiO-66-N(Bnme)2OAc material of this invention.
[0033] Figure 4This is a catalytic activity diagram of the UiO-66-N(Bnme)2OAc Pickering emulsion of the present invention undergoing five cycles of catalytic reaction. Detailed Implementation
[0034] Example 1: A method using N(BzBnme2) - Ionic liquid-modified metal-organic framework UiO-66-NH2 pickering emulsion
[0035] (a) The preparation method is as follows:
[0036] 1) Synthesis of UiO-66-NH2
[0037] ZrCl4 (0.0995 g) and 2-aminoterephthalic acid (0.0773 g) were dispersed in a mixture of 43 mL N,N-dimethylformamide (DMF) and 10 mL glacial acetic acid. After stirring for 30 min, the mixture was placed in a reaction vessel and reacted in an oven at 393 K for 24 h. After the reaction was completed, the mixture was cooled to room temperature, washed successively with DMF and ethanol, and then vacuum dried in an oven at 353 K for 12 h to obtain UiO-66-NH2 for later use.
[0038] 2) Synthesis of N(BzBnme2)Br
[0039] Benzyl bromide (1 mmol, 1.18 mL) and 4-dimethylaminobenzaldehyde (1 mmol, 1.492 g) were dispersed in 15 mL of acetonitrile, stirred at 298 K for 48 h, washed with diethyl ether, and dried under vacuum in an oven at 333 K for 8 h to obtain N(BzBnme2)Br for later use.
[0040] 3) Synthesis of UiO-66-N(Bnme)2OAc
[0041] 531 mg of UiO-66-NH2 and 384 mg of N(BzBnme2)Br were dispersed in 60 mL of methanol and stirred at 298 K for 24 h. After washing with diethyl ether, the mixture was dried under vacuum to obtain UiO-66-N(Bnme)2Br. Then, 850 mg of UiO-66-N(Bnme)2Br and 200 mg of potassium acetate were dispersed in 80 mL of methanol and stirred at 298 K for 12 h. After washing with water and methanol successively, the mixture was dried under vacuum in an oven at 333 K for 8 h to obtain UiO-66-N(Bnme)2OAc material.
[0042] 4) Preparation of UiO-66-N(Bnme)2OAc Picklerin emulsion
[0043] Place 35 mg of UiO-66-N(Bnme)2OAc into a vial, add 2 mL of toluene and 3 mL of water, sonicate, and then simply shake by hand three times to prepare UiO-66-N(Bnme)2OAc Picklein emulsion.
[0044] (II) Testing
[0045] Figure 1 This is an optical microscope image of the synthesized UiO-66-N(Bnme)2OAc Picklerin emulsion. It can be seen that the stable UiO-66-N(Bnme)2OAc Picklerin emulsion droplets are uniformly dispersed and of uniform size.
[0046] Figure 2 The image shows the PXRD pattern of the UiO-66-N(Bnme)2OAc material, indicating that the UiO-66-N(Bnme)2OAc material has good crystallinity during the synthesis and preparation process, and the introduction of ionic liquid did not change the crystallinity of the material.
[0047] Figure 3 The FT-IR spectrum of UiO-66-N(Bnme)2OAc further demonstrates the successful introduction of the ionic liquid.
[0048] Example 2: Catalytic function of UiO-66-N(Bnme)2OAc Pickering emulsion in aldehyde-amine condensation reaction
[0049] (i) The aldehyde-amine condensation reaction was catalyzed using the UiO-66-N(Bnme)2OAc Pickering emulsion prepared in Example 1 as a catalyst.
[0050] The method is as follows:
[0051] The prepared UiO-66-N(Bnme)2OAc pickering emulsion was transferred to a 10 mL three-necked flask, and then 1.0 mmol aniline and 1.2 mmol benzaldehyde were added sequentially. The reaction was carried out at 333 K for 1 h. The yield of the product was monitored by gas chromatography (GC).
[0052] During the reaction, the catalytic performance of UiO-66-N(Bnme)2OAc Pickering emulsion on the tandem reaction was detected by GC. As the reaction proceeded, the yield gradually increased. After 30 min, the yield of N-benzylimine reached 94.19%, and after 1 h, the yield reached 99.9%.
[0053] (II) Reuse of UiO-66-N(Bnme)2OAc Picklein Emulsion
[0054] After the reaction was completed, the reaction mixture was centrifuged and filtered to separate it from UiO-66-N(Bnme)2OAc. The separated mixture was washed with ethanol, filtered, and dried. The UiO-66-N(Bnme)2OAc material was recovered.
[0055] The specific operation of the cyclic experiment: the recovered UiO-66-N(Bnme)2OAc material was used to prepare the Pickering emulsion-catalyzed aldehyde-amine condensation reaction again, and the reaction was carried out at 333K for 1 h.
[0056] Experimental results are as follows Figure 4 As shown, after five cycles of the cyclic experiment, the catalyst activity did not decrease significantly, and the recovered UiO-66-N(Bnme)2OAc material could still stably form Pickering emulsions. This indicates that UiO-66-N(Bnme)2OAc in the Pickering emulsion can be recycled as a catalyst for the aldehyde-amine condensation reaction.
Claims
1. A method using N(BzBnme2) - Ionic liquid-modified metal-organic framework UiO-66-NH2 pickeril emulsion, characterized in that, The picklite emulsion is a UiO-66-N(Bnme)2OAc picklite emulsion, which is a picklite emulsion prepared using UiO-66-N(Bnme)2OAc as an emulsifier.
2. A method using N(BzBnme2) - A method for preparing an ionic liquid-modified metal-organic framework UiO-66-NH2 pickeril emulsion, characterized in that, Includes the following steps: 1) Disperse ZrCl4 and 2-aminoterephthalic acid in a mixture of DMF and glacial acetic acid, stir evenly, and then put it into a reaction vessel for hydrothermal reaction. After the reaction is completed, cool naturally to room temperature, wash with DMF and ethanol in sequence, and dry under vacuum to obtain UiO-66-NH2. 2) Benzyl bromide and 4-dimethylaminobenzaldehyde were dispersed in acetonitrile, stirred, washed with diethyl ether, and dried under vacuum to obtain N(BzBnme2)Br; 3) Disperse the UiO-66-NH2 obtained in step 1) and the N(BzBnme2)Br obtained in step 2) into methanol, stir, wash with diethyl ether, and dry under vacuum to obtain UiO-66-N(Bnme)2Br; 4) Disperse the UiO-66-N(Bnme)2Br and potassium acetate obtained in step 3) into methanol, stir, wash with water and methanol successively, and dry under vacuum to obtain UiO-66-N(Bnme)2OAc; 5) Add toluene and water to the UiO-66-N(Bnme)2OAc obtained in step 4), sonicate, and shake by hand three times to obtain UiO-66-N(Bnme)2OAc Picklein emulsion.
3. The preparation method according to claim 2, characterized in that, In step 1), the molar ratio of ZrCl4:2-aminoterephthalic acid is 1:1; the volume ratio of glacial acetic acid to DMF in the mixture of DMF and glacial acetic acid is 1:4.
3.
4. The preparation method according to claim 2, characterized in that, In step 1), the stirring time is 30 min; the hydrothermal reaction conditions are: 393 K hydrothermal reaction for 24 h.
5. The preparation method according to claim 2, characterized in that, In step 2), the molar ratio of benzyl bromo:4-dimethylaminobenzaldehyde is 1:1; the volume of acetonitrile is 15 mL; and the stirring conditions are: stirring at 298 K for 48 h.
6. The preparation method according to claim 2, characterized in that, In step 3), the mass of UiO-66-NH2 is 531 mg, the mass of N(BzBnme2)Br is 384 mg, and the volume of methanol is 60 mL; the stirring conditions are: stirring at 298 K for 24 h.
7. The preparation method according to claim 2, characterized in that, In step 4), the mass of UiO-66-N(Bnme)2Br is 850 mg, the mass of potassium acetate is 200 mg, and the volume of methanol is 80 mL; the stirring conditions are: stirring at 298 K for 12 h.
8. The preparation method according to claim 2, characterized in that, In step 5), the mass of UiO-66-N(Bnme)2OAc is 35 mg, and the volumes of toluene and water are 2 mL and 3 mL, respectively.
9. The method according to claim 1 using N(BzBnme2) - Application of ionic liquid-modified metal-organic framework UiO-66-NH2 pickering emulsion in catalytic aldehyde-amine condensation reaction.
10. The application according to claim 9, characterized in that, The application method is as follows: Add benzaldehyde and aniline to UiO-66-N(Bnme)2OAc Pickering emulsion and react at 333 K for 1 h.