Metal organic framework crystalline state material containing N-ethyl morpholine buffer system as well as preparation method and application of metal organic framework crystalline state material
By introducing N-(2-aminoethyl)morpholine groups into metal-organic framework materials to simulate the active sites of histidine residues, MOF materials containing a self-contained NEM buffer system are formed, solving the problem of easy deactivation of catalytic active centers, realizing efficient catalytic hydrolysis under humidity conditions, and expanding the application of protective equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-25
- Publication Date
- 2026-04-03
AI Technical Summary
Existing metal-organic framework materials are prone to deactivation of their catalytic active centers under conditions without alkaline buffer solutions, making it difficult to efficiently catalyze the hydrolysis of organophosphate nerve agents in humid environments, thus limiting their application in protective equipment.
By introducing N-(2-aminoethyl)morpholine groups as a basic buffer, mimicking the active sites of histidine residues, and combining with the active centers of metal clusters, MOFs materials containing a self-contained NEM buffer system are formed, enabling solid-phase catalytic hydrolysis under humidity conditions.
Under humid conditions, the material can efficiently catalyze the hydrolysis of organophosphate compounds, and the catalyst can be reused, expanding the application range of protective equipment.
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Figure CN121779732A_ABST
Abstract
Description
Technical Field
[0001] This invention specifically relates to a self-contained [material] that can be used for solid-phase catalytic hydrolysis of organophosphate nerve agents under humid conditions. N -Ethylmorpholine (NEM) buffer system metal-organic framework crystalline material belongs to the intersection of metal-organic framework crystalline materials and chemical protection. Background Technology
[0002] Organophosphate derivatives, such as nerve agents and pesticides, are among the most toxic compounds known. Representative organophosphate nerve agents include sarin (isopropyl methylflufenicol), soman (terhexyl methylflufenicol), and VX S-(2-diisopropylaminoethyl)-methylthiophosphonate ethyl ester. These compounds, after inhalation or skin absorption, inhibit the activity of acetylcholinesterase in the body, leading to a large accumulation of the neurotransmitter acetylcholine at neuronal synapses. This disrupts signal transmission from the nervous system to muscles, causing severe damage even at extremely low concentrations and within a very short time. Traditional antidotes typically involve neutralization with strongly alkaline solutions or high-temperature incineration, but these methods have limitations in terms of long-term protection and on-site detoxification.
[0003] Currently effective degradation methods include biodegradation and chemical hydrolysis. Biodegradation mainly relies on organophosphate hydrolases, such as phosphotriesterases (PTEs) found in eukaryotes. These enzymes hydrolyze organophosphates through nucleophilic attack of the phosphorus center by bridging hydroxides. The phosphoryl oxygen coordinates with the metal, polarizing the phosphorus center and allowing the bridging hydroxide to undergo nucleophilic attack, thus degrading the neurotoxin. However, biological enzymes are easily inactivated in complex environments, making them unsuitable for practical applications. In the field of chemical hydrolysis, metal-organic frameworks (MOFs), especially zirconium-based metal-organic frameworks (Zr-MOFs), such as MOF-808, UiO-66-NH2, and NU-1000, constitute a growing class of phosphatase-like nanozymes, exhibiting unique advantages in catalyzing the hydrolysis of organophosphate neurotoxins. Firstly, the metal nodes of Zr-MOF materials are Zr6 clusters, whose active sites mimic the Zn content of the phosphatase family. II –OH–Zn II The active sites greatly promote the catalytic hydrolysis of P−X (X = F, S, CN, etc.) bonds. Secondly, Zr-MOFs materials possess mesoporous and microporous structures, and their extremely large specific surface area allows nerve agents to be adsorbed into the pores, subsequently degraded using abundant catalytic sites; these are known as self-excreting catalysts. However, catalytic reactions are often limited to alkaline buffer solutions (typically using...). NIn the absence of buffer solution, the active sites of MOFs bind to hydrolysis products, leading to the deactivation of their catalytic active centers. The fluidity, volatility, and corrosiveness of liquid alkaline buffer solutions severely limit the application of Zr-MOF catalytic systems in areas such as camp protective equipment (protective clothing, gas masks), and antidotes.
[0004] Therefore, achieving efficient catalytic degradation of organophosphates under humidity conditions is of great significance for the development of protective equipment, and researchers at home and abroad have conducted extensive research. For example, Chen, Baek, and others have used and developed several solid amine polymer buffers, including linear, branched, and dendritic polyethyleneimine (PEI), polyethylenediamine (PAMAM) dendritic macromolecules, and polymorpholine (P(MEMA)), to replace the buffering effect of NEM. After being combined with Zr-MOFs, they achieved solid-phase catalytic hydrolysis of nerve agents under humidity conditions. However, the thick polymer layer reduces the porosity of the MOF catalyst, acting as a mass transfer barrier, which greatly reduces the diffusion rate of nerve agents and water, resulting in a decrease in catalytic activity. Farha, Navarro, Liu, and others have used solution-assisted ligand insertion or vapor diffusion methods to immobilize Li(OR), Mg(OMe)2, imidazole, and carboxylic acid ligands containing basic amine groups (morpholine, dimethylamine, etc.) onto the Zr6 clusters or pores of Zr-MOF catalysts. However, because the catalytic sites of the Zr6 cluster are occupied, the accessibility of the catalytic active sites becomes worse, and the catalytic ability is reduced.
[0005] To meet the needs of protective equipment development, the development of protective materials capable of efficiently degrading organophosphorus phosphates under solid-phase conditions has become an urgent requirement. By mimicking the active sites of PTE and the histidine residues linked to them, functional groups with water-absorbing and alkaline buffering functions are introduced into Zr-MOF materials, resulting in a single material capable of efficiently hydrolyzing nerve agents under certain humidity conditions. This represents one of the most reliable solutions to the current protective equipment problem. No relevant literature reports have been found to support this approach. Summary of the Invention
[0006] Based on the current state of technology, the purpose of this invention is to provide a self-contained N The metal-organic framework crystalline material of the ethylmorpholine (NEM) buffer system is used to treat organophosphates to achieve solid-phase catalytic hydrolysis of organophosphate nerve agents under humid conditions; another objective is to provide its preparation method.
[0007] To achieve the objectives of this invention, we have developed a series of products containing... NA biomimetic catalyst based on porous crystalline metal-organic frameworks (MOFs-NEMs) using a (2-aminoethyl)morpholine buffer system. MOFs possess periodic Lewis acidic metal-oxygen clusters, and their M-OH-M sites are similar to the Zn-OH-Zn active sites of PTEs, enabling the activation and breaking of P−X bonds. The NEM groups mimic the substrate activation of histidine residues and provide an alkaline environment for the system, allowing MOFs-NEM materials to catalyze the hydrolysis of organophosphate compounds in the absence of an alkaline buffer and with the participation of water molecules in the air. Furthermore, this type of catalyst exhibits reusability in catalytic hydrolysis of phosphate esters.
[0008] The specific technical solution is as follows: This invention starts with ligand modification to create compounds with buffering and hydrophilic properties. N (2-Aminoethyl)morpholine is introduced into a carboxylic acid ligand, and then, utilizing the high specific surface area, porous structure, and modifiable nature of MOFs, it is self-assembled with metal ions or metal clusters such as Zr, Hf, and Ce to obtain crystalline materials MOF-NEMs containing NEM base sites. MOF-NEMs introduce basic NEM groups near the active centers of metal clusters, enabling solid-phase catalytic hydrolysis of organophosphate nerve agents under humid conditions. When organophosphate nerve agent vapors are adsorbed by the pores of MOF-NEMs, they are catalytically hydrolyzed by the active centers of the metal clusters in conjunction with the NEM groups, with the participation of H2O molecules in the air. Simultaneously, the OH groups provided by the NEM groups... – This avoids the deactivation of the active centers of the metal clusters. More importantly, the catalytically treated material can be washed away with a weakly alkaline solution to remove the catalytic products, enabling the catalyst to be reused. The MOF-NEMs synthesized in this invention can eliminate the dependence on large amounts of water and alkaline buffer solutions when degrading phosphate ester compounds, greatly improving the applicability of MOFs and providing a feasible solution for individual soldier protective materials and spatiotemporal protection in military camps in practical applications.
[0009] The general molecular formula of the carboxylic acid ligand containing the N-(2-aminoethyl)morpholine group is: m = 2-4, n = 1-4, x = 0 or 1, Ar = benzene, biphenyl, p-terphenyl, 1,3,6,8-tetraphenylpyrene, 1,3,5-triphenylbenzene.
[0010] This invention selects transition metals Zr, Hf, and Ce and introduces... N Carboxylic acid organic ligands with the -(2-aminoethyl)morpholine group are linked to form structurally stable metal-organic framework structures, as shown in Table 1.
[0011] Table 1. MOFs designed in this invention (1) Synthesis of MOF-808-xNEM with spn topology Based on the MOF-808 ligand pyromellitic acid (H3BTC), ligands containing different numbers of NEM functional groups, namely H3BTC-NEM, H3BTC-2NEM, and H3BTC-3NEM, were synthesized. The synthetic strategy utilized trimethyl-2-bromophenyl-1,3,5-tricarboxylic acid ester with... N The Buchwald-Hartwig cross-coupling reaction between (2-aminoethyl)morpholine and morpholine yielded the ligand H3BTC-NEM upon hydrolysis. When the substrate was changed to a trimethyl-2,4-dibromophenyl-1,3,5-tricarboxylic acid ester containing two bromine atoms or a trimethyl-2,4,6-tribromophenyl-1,3,5-tricarboxylic acid ester containing three bromine atoms, H3BTC-2NEM and H3BTC-3NEM were obtained respectively via the same synthetic route.
[0012] Based on H3BTC-NEM, H3BTC-2NEM and H3BTC-3NEM and M 4+ Ions (M = Zr, Hf, Ce, etc.) or MO 2+ Ion or metal cluster M6 ( μ 3-O)4( μ 3-OH)4 self-assembly can yield M-MOF-808-NEM, M-MOF-808-2NEM and M-MOF-808-3NEM with 3,6-c connected spn topology. Figure 1 ).
[0013] (2) Synthesis of UiO-NEMs with fcu topology Based on the ligand terephthalic acid (H2BDC) of UiO-66, using H2BDC-Br with... N The Buchwald-Hartwig cross-coupling reaction between (2-aminoethyl)morpholine and H2BDC-NEM was obtained by hydrolysis.
[0014] Based on the UiO-67 ligand 1,4-biphenyl dicarboxylic acid (H2BPDC), the ligand H2BPDC-NEM was designed. The synthetic scheme is as follows: 2-methyl-4,4'-biphenyl dicarboxylic acid diethyl ester was synthesized via a Suzuki coupling reaction between ethyl 4-bromo-3-methylbenzoate and 4-ethoxycarbonylphenylboronic acid; the methyl group was then brominated using N-bromosuccinimide (NBS) as the brominating agent. The bromine and N-(2-aminoethyl)morpholine underwent an ammonolytic coupling reaction in alkaline solution, followed by hydrolysis to yield the ligand H2BPDC-NEM.
[0015] Based on the UiO-68 ligand [1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid (H2TDA), ligands H2TDA-xNEM (x = 1 and 2) were designed. H2TDA-NEM and H2TDA-2NEM have larger sizes, and H2TDA-2NEM contains two NEM functional groups. The synthetic scheme is as follows: 2'-methyl-[1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid ester is synthesized via a Suzuki coupling reaction between 1,4-dibromo-2-toluene and 4-boronic acid benzoate. N Bromosuccinimide (NBS) is used as a brominating agent to bromine methyl groups. N -(2-Aminoethyl)morpholine undergoes an ammonocoupling reaction in alkaline solution, followed by hydrolysis to yield the ligand H2TDA-NEM. By changing the substrate to 1,4-dibromo-2,5-xylene and following the same synthetic route, H2TDA-2NEM can be obtained.
[0016] The ligands H2BDC-NEM, H2TDA-NEM, and H2TDA-2NEM are respectively associated with M 4+ Ions or MO 2+ Ion or metal cluster M6 ( μ 3-O)4( μ 3-OH)4 (M = Zr, Hf, Ce, etc.) undergoes a self-assembly reaction in the presence of a template agent (formic acid, acetic acid, benzoic acid, trifluoroacetic acid, etc.) to yield crystals M-UiO-66-NEM, M-UiO-67-NEM, M-UiO-68-NEM, and UiO-68-2NEM. Figure 2 ).
[0017] To obtain ligands with different topologies, larger sizes, and the ability to introduce more NEM functional groups, H4TBAPy-4NEM was synthesized based on the NU-1000 ligand. The synthetic strategy for the ligand involved the Suzuki coupling reaction of 1,3,6,8-tetrabromopyrene with 4-(methoxycarbonyl)-3-methylphenylboronic acid ester to synthesize 4,4',4'',4''-(pyrene-1,3,6,8-tetramethyl)tetra(3-methylcarbamate), followed by NBS bromide methylation and... N -(2-Aminoethyl)morpholine undergoes an ammonolysis coupling reaction in alkaline solution, followed by hydrolysis to yield the ligand H4TBAPy-4NEM.
[0018] Following the same MOF-NEM synthesis scheme, based on H4TBAPy-4NEM and M 4+ Ions or MO 2+Ion or metal cluster M6 ( μ 3-O)4( μ 3-OH)4 (M = Zr, Hf, Ce, etc.) can self-assemble in the presence of different template agents to obtain M-NU-901-4NEM with 8-c-linked scu topology and M-NU-1000-4NEM with csq topology. Figure 3 ).
[0019] Based on the ligand 1,3,5-tris(4-carboxyphenyl)benzene (H3BTB) of the two-dimensional material Zr-BTB, H3BTB-NEM, H3BTB-2NEM, and H3BTB-3NEM were synthesized. The synthetic strategy involved the Suzuki coupling reaction of 1,3,5-tribromobenzene with varying numbers of methyl-substituted esters with 4-borate benzoate, followed by NBS bromination of the methyl groups. The reaction utilized bromine with... N The aminohydrocoupling reaction between -(2-aminoethyl)morpholine yields ligands H3BTB-NEM, H3BTB-2NEM, and H3BTB-3NEM containing 1, 2, and 3 NEMs, respectively, after hydrolysis.
[0020] Based on H3BTB-NEM, H3BTB-2NEM and H3BTB-3NEM and M 4+ Ions or MO 2+ Ion or metal cluster M6 ( μ 3-O)4( μ 3-OH)4 (M = Zr, Hf, Ce, etc.) self-assembly can yield M-BTB-NEM, M-BTB-2NEM and M-BTB-3NEM with 3,6-c connected kgd topologies. Figure 4 ).
[0021] Advantages of this invention: The enzyme-like MOF-NEM catalyst described in this invention uses transition metals (Zr, Hf, Ce) as catalytic active centers, enabling efficient solid-phase catalytic degradation of organophosphate nerve agent mimics under humid conditions. This MOF contains abundant Lewis acid catalytic sites and provides an alkaline environment through Lewis basic functional groups, effectively mimicking the structure of phosphotriesterase (PET) in nature. The MOF's porous structure can adsorb water vapor from the air, achieving efficient solid-state degradation of the nerve agent mimic DMNP under humid conditions. This solves the problem of traditional catalysts' over-reliance on alkaline buffer solutions for detoxification, hindering efficient nerve agent degradation. Furthermore, it expands the range of enzyme-like MOF catalysts, facilitating research into the degradation mechanisms of chemical warfare agents. This provides a reference for the preparation of protective materials for chemical warfare agents in actual battlefield environments. Attached Figure Description
[0022] Figure 1 The spn topology M-MOF-NEMs synthesized in this invention (taking Zr-MOF-808-NEM as an example); Figure 2 The fcu topology M-UiO-NEMs synthesized in this invention (taking Zr-UiO-66-NEM as an example); Figure 3 The SCU topology M-NU-1000-NEM and CSQ topology M-NU-901-NEM synthesized in this invention (taking Zr as an example); Figure 4 The above describes the kgd topological MOF-NEMs synthesized in this invention (taking Zr-BTB-NEM as an example). Figure 5 The images show the relevant performance characteristics of the MOF-808-NEM synthesized in this invention, including (a) PXRD; (b) SEM; (c) nitrogen adsorption-desorption curves; (d) FT-IR; and (e) after digestion. d (f) NMR of DMSO / D2SO4; (g) Solvent stability test; (h) EDX elemental mapping; (f) Water contact angle; Figure 6 The figures show the performance of the MOF-808-NEM solid-phase catalytic hydrolysis of DMNP synthesized in this invention, where (a) is compared with MOF-808 with a catalyst loading of 12 mol%; (b) the catalytic performance with catalyst loadings of 6 mol%, 12 mol%, and 18 mol%; (c) the catalytic performance at RH of 50%, 75%, and 99%; and (d) the catalytic performance at temperatures of 25ºC, 45ºC, and 65ºC. Figure 7 The following are the NEM performance diagrams of the UiO-66-N synthesized in this invention, including (a) PXRD; (b) SEM; (c) nitrogen adsorption-desorption curve; (d) FT-IR; (e) NMR after digestion (NaOD / D2O); (f) solvent stability test; (g) EDX elemental mapping; and (h) water contact angle. Figure 8 The following are performance diagrams of the solid-phase catalytic hydrolysis of DMNP using UiO-66-NEM synthesized in this invention: (a) comparison with MOF-808 at 12 mol% catalyst loading; (b) catalytic performance at 6 mol%, 12 mol%, and 18 mol% catalyst loading; (c) catalytic performance at RH of 50%, 75%, and 99%; and (d) catalytic performance at temperatures of 25ºC, 45ºC, and 65ºC. Detailed Implementation
[0023] The invention will be further illustrated by the following examples: Example 1: Synthesis of (Zr)MOF-808-NEM material and its application in solid-state degradation of nerve agent simulants under humidity conditions (1) Synthesis of H3BTC-NEM 2-( N Synthesis of methyl 2-bromo-1,3,5-trimethylammonium phosphate (2-aminoethyl)morpholine-1,3,5-trimethylammonium phosphate: 1000 mg of methyl 2-bromo-1,3,5-trimethylammonium phosphate (3 mmol) was prepared. N 1,4-Dioxane (1.42 g, 9 mmol), cesium carbonate (1.95 g, 6 mmol), 4,5-bis(diphenylphosphine)-9,9-dimethyloxanthracene (XANTPHOS) (350 mg, 0.6 mmol), and Pd2(dba)3 (280 mg, 0.3 mmol) were uniformly dispersed in 50 mL of 1,4-dioxane. The mixture was heated to 95 °C and stirred under nitrogen protection for 60 h. The reaction was cooled to room temperature, and the reaction was quenched with about 50 mL of water. The mixture was extracted three times with ethyl acetate, and the organic phase was retained. The product was separated by column chromatography (eluent: petroleum ether: ethyl acetate = 2:1) to give a pure yellow solid with a yield of about 75%. 1 H NMR (400 MHz, DMSO) δ 8.14 (s, 2H), 3.62 - 3.51 (m, 5H), 3.17 (t, J = 6.7 Hz, 3H), 2.47 (t, J = 6.8 Hz, 2H), 2.38 (s, 4H).
[0024] 2-( N Synthesis of 2-(N-(2-aminoethyl)morpholine)-1,3,5-pyromellitic acid: 200 mg (0.53 mmol) of methyl 2-(N-(2-aminoethyl)morpholine)-1,3,5-pyromellitic acid was weighed and dissolved in a mixed solution of 3 mL 1M KOH, 3 mL CH3OH and 3 mL THF. The mixture was heated to 60-65 °C and stirred under reflux for 24 h. The reaction mixture was cooled to room temperature and extracted with ethyl acetate, retaining the aqueous phase. The aqueous phase was adjusted to pH 3-4 with 1M HCl and evaporated to dryness using a rotary evaporator. The resulting solid was recrystallized from ethanol solution, filtered to remove insoluble inorganic salts, and the liquid was retained and evaporated to dryness. The product was a white solid with a yield of approximately 76%. 1 HNMR (400 MHz, DMSO) δ 8.14 (s, 6H, ArH), 3.56 (t, J = 8 Hz, 4H, CH2), 3.17 (t,J = 7.8 Hz, 2H, CH2), 2.49 (t, J = 8 Hz, 2H, CH2), 2.45 (t, J = 7.8 Hz, 4H, CH2).
[0025] (2) Synthesis of Zr-MOF-808-NEM Weigh out 23 mg (0.1 mmol) ZrCl4 and (11 mg, 0.0336 mmol) 2-( N (2-Aminoethyl)morpholine-1,3,5-pyromellitic acid was added to a 5 mL screw-top vial, followed by 350 μL of acetic acid and 1 mL of DMF. The mixture was sonicated for 20 min to ensure homogeneity. The vial was then placed in a 130 °C oven and reacted for 48 h. After cooling to room temperature, the solid was washed three times with 8 mL of DMF every two hours, followed by three times with 8 mL of acetone every two hours, including one soaking in acetone for 12 h. The resulting white crystals were dried in a vacuum drying oven at 80 °C.
[0026] (3) Characterization of Zr-MOF-808-NEM PXRD and SEM showed that Zr-MOF-808-NEM had the same crystal planes as MOF-808, as well as good crystallinity and phase purity. Figure 5 (ab). The N2 adsorption-desorption isotherms of Zr-MOF-808-NEM show type I isotherms, indicating that Zr-MOF-808-NEM has microporous characteristics. The specific surface area (BET) is 450 m². 2 g -1 It is far lower than the 1567 m of MOF-808. 2 g -1 This can be attributed to the NEM functional groups introduced into the channels ( Figure 5 c). FT-IR spectroscopy confirms the presence of CN stretching vibration absorption peaks in the material. Figure 5 (d). Additionally, by adding Zr-MOF-808-NEM to... d After digestion in a mixed solution of DMSO and D2SO4, from 1 Characteristic peaks of NEM groups can be observed in H NMR ( Figure 5 (e). TEM-EDX elemental mapping images show a uniform distribution of Zr, C, O, and N elements. Figure 5 (g). These test results all demonstrate the successful introduction of the NEM group and the successful preparation of Zr-MOF-808-NEM. The reduction in pore surface area also gives Zr-MOF-808-NEM good stability in common solvents such as tetrahydrofuran, water, toluene, etc.N , N It remains stable after being soaked in dimethylformamide and 1,4-dioxane for 48 hours. Figure 5 (f). Water contact angle tests showed that the contact angles of water droplets on the MOF-808 and Zr-MOF-808-NEM surfaces were 45.2° and 33.4°, respectively, indicating that Zr-MOF-808-NEM has better hydrophilicity than MOF-808. Figure 5 (h).
[0027] (4) Zr-MOF-808-NEM solid-state catalytic hydrolysis of organophosphate nerve agent mimic 4-nitrobenzene phosphate (DMNP) The solid-state catalytic hydrolysis reaction of DMNP was carried out in a DHTHM-27-20-P-SD ambient humidity chamber. Before catalysis, Zr-MOF-808-NEM material was activated under vacuum at 100 °C for 12 h. The required amount of Zr-MOF-808-NEM was weighed into a 10 mL screw-top glass bottle, and then DMNP (4 μL, 0.025 mmol) was added. After thorough mixing, the bottle was placed in the humidity chamber, which had already met the preset reaction conditions, and left open. After the reaction was complete, 0.7 mL of a D2SO4 / DMSO-d6 (15 / 100) mixed solution was added. The Zr-MOF-808-NEM was completely digested by sonication. The reaction mixture was then transferred to an NMR tube, and the NMR was measured... 31 The hydrolysis conversion of DMNP was obtained from P NMR data. The analysis was performed on a Bruker Avance-400 spectrometer. 1 H NMR and in situ 31 P NMR spectroscopy experiment.
[0028] This invention investigated the catalytic performance of Zr-MOF-808-NEM in degrading organophosphorus nerve agents under humid conditions. Zr-MOF-808-NEM was uniformly mixed with DMNP and placed in a humidity chamber. After catalysis, 600 μL (100 / 15) of a mixed solution of d-DMSO and D2SO4 was used. 31 The degradation results were analyzed by integral calculation using P NMR. For example... Figure 6 As shown in Figure a, under conditions of 25℃, 99% RH, and a catalyst dosage of 12 mol%, the half-life of MOF-808-NEM in degrading DMNP was less than 30 min, compared to MOF-808, which did not reach half the conversion rate even after 12 h. Zr-MOF-808-NEM exhibited significantly higher catalytic activity than MOF-808, approximately 3.5 times the catalytic rate of MOF-808. This indicates that under RH conditions, NThe introduction of α-(2-aminoethyl)morpholine enhanced the catalytic performance of the material. We found that by varying the catalyst dosage of Zr-MOF-808-NEM... Figure 6 (b) A 12 mol% catalyst showed good catalytic degradation of DMNP. The catalytic performance of Zr-MOF-808-NEM under different humidity conditions was investigated by varying humidity levels. Figure 6 As shown in Figure c, the catalytic activity of Zr-MOF-808-NEM gradually decreased with decreasing humidity (RH = 50%, 75%, 99%). The experimental results indicate that the catalytic process mainly requires water and has a high water dependence. Maintaining RH = 99% and a catalyst dosage of 12 mol%, the reaction temperature was changed... Figure 6 (d) The activity of Zr-MOF-808-NEM in degrading DMNP at different temperatures increases with increasing temperature.
[0029] Example 2: Synthesis of (Zr)UiO-66-NEM material and its application in solid-state degradation of nerve agent simulants under humidity conditions (1) Synthesis of ligand H2BDC-NEM 2-( N Synthesis of methyl 2-bromo-1,4-terephthalate: methyl 2-bromo-1,4-terephthalate (820 mg, 3 mmol) was prepared. N (2-Aminoethyl)morpholine (950 mg, 6 mmol), cesium carbonate (1.95 g, 6 mmol), XANTPHOS (350 mg, 0.6 mmol), and Pd2(dba)3 (280 mg, 0.3 mmol) were uniformly dispersed in 50 mL of 1,4-dioxane. The mixture was heated to 95 °C and stirred under nitrogen protection for 60 h. The reaction was cooled to room temperature, and about 50 mL of water was added to quench the reaction. The mixture was extracted three times with ethyl acetate, and the organic phase was retained. The product was separated by column chromatography (eluent: petroleum ether: ethyl acetate = 2:1) to give a pure yellow solid with a yield of about 72%. 1 H NMR (400 MHz, CDCl3) δ 7.95 (d, J = 8.3 Hz, 1H), 7.34 (d, J = 1.3 Hz, 1H), 7.20 (dd, J = 8.3, 1.5 Hz, 1H), 3.90 (d, J = 11.2Hz, 6H), 3.80 - 3.72 (m, 4H), 3.35 (dd,J = 11.1, 6.2 Hz, 2H), 2.70 (t, J = 6.3Hz, 2H), 2.52 (s, 4H).
[0030] 2-( N Synthesis of (2-aminoethyl)morpholine-1,4-terephthalic acid: Weigh 2-( N Methyl 1,4-(2-aminoethyl)morpholine)-1,4-terephthalate (200 mg, 0.6 mmol) was dissolved in a mixture of 2 mL 1M KOH solution, 2 mL methanol, and 2 mL tetrahydrofuran. The mixture was heated to 60-65 °C and refluxed with stirring for 16 h. The reaction mixture was cooled to room temperature and extracted with ethyl acetate, retaining the aqueous phase. The aqueous phase was adjusted to pH 4-5 with 1M HCl, and ethanol was added and evaporated to dryness. The resulting solid was then added back to ethanol, and the mixture was sonicated to completely dissolve the product in ethanol. The insoluble inorganic salts were removed by filtration, and the liquid was retained and evaporated to dryness. The product was a yellow solid with a yield of 74%. ¹H NMR (400 MHz, DMSO) δ 7.77 (d, J = 8.2 Hz, 1H), 7.15 (s, 1H), 6.99 (d, J =8.2 Hz, 1H), 3.51 (d, J = 4.1 Hz, 4H), 3.19 (t, J = 6.1 Hz, 2H), 2.51 (t, J = 6.1Hz, 2H), 2.35 (s, 4H).
[0031] (2) Synthesis of Zr-UiO-66-NEM Weigh ZrCl4 (10 mg, 0.043 mmol) and 2-(N-(2-aminoethyl)morpholine)-1,4-terephthalic acid (13 mg, 0.043 mmol) into a 10 mL screw-top vial, then add 200 μL of acetic acid and 5 mL of DMF. Sonicate for 20 min to mix thoroughly. Weigh out a total of 6 vials. Place the vials in a 120 °C oven and react for 24 h. Cool to room temperature. Wash the solid three times with 8 mL of DMF every two hours, then wash three times with 8 mL of acetone every two hours, including one soaking in acetone for 12 h. Dry the resulting yellow solid in a vacuum drying oven at 80 °C.
[0032] (3) Characterization of Zr-UiO-66-NEM Characterization of Zr-UiO-66-NEM as follows Figure 7 As shown. The crystal structure of Zr-UiO-66-NEM was tested using PXRD, as shown. Figure 7 As shown in Figure a, Zr-UiO-66-NEM exhibits the same PXRD diffraction peak positions as UiO-66, located at 2θ = 7.3, 8.5, and 25.8°, respectively, which are related to the (111), (002), and (224) crystal planes, respectively. This is completely consistent with the characteristic peaks exhibited by Zr-UiO-66-NEM. SEM shows that Zr-UiO-66-NEM is octahedral with a particle size of approximately 400 nm. Figure 7 (b). The nitrogen adsorption-desorption isotherm of Zr-UiO-66-NEM shows a type I hysteresis loop ( Figure 7 (c) has a microporous structure and a specific surface area of 330 m². 2 ·g -1 FT-IR display tests were conducted at 1603 and 1260 cm⁻¹. -1 The absorption peaks observed at 769 and 665 cm⁻¹ correspond to the skeletal vibrations of the benzene ring and the stretching vibrations of CN in the Zr-UiO-66-NEM. -1 The peak at that location originates from the stretching vibration of Zr-O. Figure 7 (d). The results of FT-IR spectroscopy indicate that... N Characteristic peaks of the -(2-aminoethyl)morpholine group were observed, and the NEM was present in Zr-UiO-66-NEM without any chemical change due to the synthesis of MOF. 1 H NMR investigation of the ligand 1H NMR spectrum after Zr-UiO-66-NEM digestion ( Figure 7 (e), observed N The characteristic peaks of the -(2-aminoethyl)morpholine group at 3.56, 3.44, 2.47, and 2.38 ppm indicate that during the synthesis of Zr-UiO-66-NEM from the ligand, N The -(2-aminoethyl)morpholine group exhibits good chemical stability. After soaking Zr-UiO-66-NEM in different solutions for over 48 hours, Zr-UiO-66-NEM maintained good stability and crystallinity, indicating that Zr-UiO-66-NEM remains stable under both polar and non-polar solutions.
[0033] (4) Solid-state catalytic degradation of DMNP by Zr-UiO-66-NEM The results of Zr-UiO-66-NEM solid-state catalytic degradation of DMNP are as follows: Figure 8 As shown. Zr-UiO-66-NEM and DMNP were mixed thoroughly and placed in a humidity chamber. At different catalytic time points, the reacted MOF was digested with a mixed solution of 600 μL (100 / 15) of d-DMSO and D2SO4. 31The degradation results were analyzed by integral calculation using P NMR. For example... Figure 8 As shown in Figure a, under reaction conditions of 25 °C, RH = 99%, and catalyst dosage of 12 mol%, Zr-UiO-66-NEM reached its catalytic degradation half-life in 30 min, while UiO-66 only achieved a catalytic conversion rate of 15% after 12 h. Zr-UiO-66-NEM exhibited a significantly higher catalytic rate than UiO-66, approximately five times that of UiO-66. This indicates that under humid conditions... N The introduction of -(2-aminoethyl)morpholine enhanced the catalytic performance of UiO-66. At a catalyst dosage of 12 mol%, DMNP exhibited the best contact with MOF and moisture in the air, and also the optimal catalytic capacity. Figure 8 (b) The catalytic performance of Zr-UiO-66-NEM under different humidity conditions was investigated by changing the humidity, such as... Figure 8 As shown in Figure c, the catalytic half-life of Zr-UiO-66-NEM degradation of DMNP gradually increases with decreasing humidity, and the final conversion rate also decreases with decreasing humidity. When the RH is 75% and 50%, the final conversion rates are 45% and 36%, respectively. The experimental results indicate that the catalytic process mainly requires the participation of water, and the higher the humidity, the better the catalytic degradation effect. Maintaining a reaction condition of 99% humidity, changing the reaction temperature, the reaction rate of Zr-UiO-66-NEM gradually increases with increasing reaction temperature. Figure 8 (d).
[0034] It can be seen that the series of crystalline metal-organic framework materials synthesized in this invention can achieve highly efficient catalytic hydrolysis of the organophosphate nerve agent mimic 4-nitrophenyl phosphate (DMNP) under humid conditions.
Claims
1. A series of metal-organic framework materials, characterized in that: Utilizing N The carboxylic acid ligand of the -(2-aminoethyl)morpholine group and the metal M 4+ Ions or MO 2+ Ion or metal cluster M6 ( μ 3-O)4( μ 3-OH)4 undergoes a self-assembly reaction in the presence of formic acid, acetic acid, propionic acid, benzoic acid, or trifluoroacetic acid as a template agent to synthesize a series of compounds containing... N -Ethylmorpholine buffer system metal-organic framework materials, abbreviated as MOFs-NEM; MOFs contain pores containing N -Ethylmorpholine functional group; the metal M is selected from Zr, Hf, Ce; the containing N The general molecular formula of the carboxylic acid ligand with the -(2-aminoethyl)morpholine group is: m = 2-4, n = 1-4, x = 0 or 1, Ar = benzene, biphenyl, p-terphenyl, 1,3,6,8-tetraphenylpyrene or 1,3,5-triphenylbenzene.
2. The metal-organic framework material as described in claim 1, characterized in that, The containing N The carboxylic acid ligand of the -(2-aminoethyl)morpholine group is selected from one of the following compounds: Series A: ； Series B: ； ； C series: ； D series: 。 3. The metal-organic framework material as described in claim 1 or 2, characterized in that, It has spn topology, fcu topology, csq topology, scu topology or kgd topology.
4. A method for preparing the metal-organic framework material as described in claims 1, 2, or 3, characterized in that, This can be achieved through the following steps: (1) Preparation containing N Polycarboxylic acid ligands with -(2-aminoethyl)morpholino group Carboxylic acid ester ligand derivatives corresponding to the target analyte and N The -(2-aminoethyl)morpholine group is obtained by hydrolysis via amination coupling or Buchwald-Hartwig cross-coupling reaction to yield a product containing... N Polycarboxylic acid ligands with a (2-aminoethyl)morpholine group; (2) Preparation containing N -(2-aminoethyl)morpholine metal-organic frameworks The above-prepared product containing N -(2-aminoethyl)morpholino group polycarboxylic acid ligands and metal M 4+ Ions or MO 2+ Ion or metal cluster M6 ( μ 3-O)4( μ 3-OH)4 undergoes a self-assembly reaction in the presence of formic acid, acetic acid, propionic acid, benzoic acid, or trifluoroacetic acid as a template agent to yield a product containing... N - (2-aminoethyl)morpholine buffer system metal-organic framework material; the metal M is selected from Zr, Hf, Ce.
5. The application of the metal-organic framework material as described in claim 1, 2, or 3 in the hydrolysis of organophosphates, characterized in that, It was used for the solid-phase catalytic hydrolysis of organophosphate nerve agents sarin (GB), soman (GD), VX (VX), or their analogues under humid conditions.
6. The application of the metal-organic framework material as described in claim 5 in the hydrolysis of organophosphates, characterized in that, Catalytic reaction conditions: Atmospheric humidity of 30-100%.