Amidoxyl group ligands, and their use in the preparation of metal-organic framework materials

Abstract

The application belongs to the field of nanometer material preparation, and discloses a method for directly preparing metal-organic framework materials with amidoxime function by one-step reaction, and discloses an organic ligand with a novel structure, and the metal-organic framework material is constructed by using the ligand through one-step method.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nanomaterial preparation and application, and particularly relates to a kind of amidoxime functionalized metal-organic framework material, its ligand and preparation method. BACKGROUND

[0002] Uranium is an important strategic resource indispensable for the development of nuclear industry. According to the current consumption rate, the limited land uranium resources will be depleted within 100 years. The ocean contains about 4.5 billion tons of uranium, which is 1000 times of the land reserves. Therefore, the extraction of uranium from seawater is expected to solve the dilemma of uranium resource shortage. Currently, various technologies for extracting uranium from seawater have been established, such as adsorption, ion exchange and electrochemistry. Among them, adsorption technology shows unique advantages such as low energy consumption, environmental friendliness and strong adaptability, and the innovative design, optimization and application of new materials are the key to promote its development. Currently, different types of uranium adsorption materials have been developed, including hydrogels, covalent organic frameworks (COFs), porous organic polymers (POPs), porous aromatic framework materials (PAFs), metal-organic frameworks (MOFs), and biomaterials, etc., but their adsorption performance for uranium is still severely affected by the ultra-low concentration of uranium (about 3.3 ppb) in seawater, coexisting interfering ions and complex biological environment. Therefore, it is urgent to develop new adsorption materials with high adsorption capacity and selectivity.

[0003] Metal-organic frameworks (MOFs) are mixed crystal materials assembled by clusters of metal ions and organic ligands. Compared with traditional porous materials, MOFs have excellent structural properties (such as topological diversity and clear spatial structure) and flexible modifiable and customizable properties. Since MOFs were first applied to uranium extraction, different series (such as MILs, UiOs, ZIFs) and / or various functionalized MOFs adsorption materials have been developed. In order to obtain excellent adsorption performance, MOFs usually introduce amidoxime groups (AO), because AO has strong affinity and excellent selectivity for uranium, such as UiO-66-AO, PCN-222-AO, MIL-101-AO, etc. However, amidoxime functionalization is achieved by post-synthesis modification of MOFs, and the reaction results in low grafting efficiency and structural stability of the material, which ultimately affects the adsorption performance of MOFs for uranium in seawater.

[0004] In view of this, the application synthesizes an amidoxime group organic ligand and prepares an amidoxime functionalized metal-organic framework material by one-step method. The research of the application helps to improve the adsorption performance of the amidoxime functionalized metal-organic framework material and deepen the research of the amidoxime functionalized metal-organic framework material.

[0005] The name explanation in the application: COFs is the abbreviation of Covalent Oragnic Frameworks; POPs is the abbreviation of Porous Organic Polymers; PAFs is the abbreviation of Porous Aromatic Frameworks; MOFs is the abbreviation of Metal-Organic Frameworks. SUMMARY

[0006] The application aims at the defects of the prior art, and provides a new organic ligand and a preparation method of amidoamine functionalized metal-organic framework, so as to solve the problem that the amidoamine functionalized metal-organic framework cannot be synthesized in one step in the prior art.

[0007] To achieve the technical purpose, the application adopts the following technical scheme.

[0008] A ligand 2-(N'-hydroxyl carbamoyl) terephthalic acid which can be used for preparing metal-organic framework material, and the structural formula is as follows:

[0009]

[0010] An amidoamine functionalized metal-organic framework material is prepared by the one-step method from the 2-(N'-hydroxyl carbamoyl) terephthalic acid prepared above, and the core of the metal-organic framework material is ZrO4(OH)4, all the edges of the polyhedron are bridged by the carboxylic acid (-CO2) to form ZrO4(OH)4(CO2). 12 cluster, and the metal-organic framework material is called UiO-66-AO one .

[0011] The application provides a preparation method of amidoamine functionalized metal-organic framework material, and the steps are as follows: the ligand 2-(N'-hydroxyl carbamoyl) terephthalic acid and zirconium salt are dissolved into a solvent, and the amidoamine functionalized metal-organic framework material is synthesized by solvent thermal reaction.

[0012] As preferred, the zirconium salt in the above reaction is water-soluble zirconium salt (soluble in water), which can be selected from any one or a combination of several of ZrCl4 and ZrOCl2·8H2O.

[0013] As preferred, the above reaction is carried out in a mixed system of water and DMF, and the volume ratio of water to DMF is (0-1) : 1.

[0014] As preferred, an acid regulator is added in the above reaction, the acid is glacial acetic acid, hydrochloric acid, trifluoroacetic acid, and the volume ratio of the H2O / DMF mixed solution and the acid regulator is 1:(0-1).

[0015] As preferred, the reaction temperature in the above reaction is 95-150℃, and the reaction time is 12h-5d.

[0016] Meanwhile, the application provides a preparation method of 2-(N'-hydroxy carbamoyl) terephthalic acid, comprising the following steps:

[0017] (1) Compound A is reacted with di-tert-butyl dicarbonate and 4-dimethylaminopyridine to obtain compound B;

[0018] (3) Compound B is reacted with cuprous cyanide to obtain compound C;

[0019] (4) Compound C is reacted with hydroxylamine to obtain compound D;

[0020] (5) Compound D is deprotected under acidic conditions to obtain compound I.

[0021] In the formula, the compound structure is as follows:

[0022] BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is an SEM image of the amidoxime-based metal-organic framework material described in the application. DETAILED DESCRIPTION

[0024] The specific implementation of the application is further described below in combination with the drawings and examples, but the application is not limited by the following examples. It should be noted that if the following processes are not specifically described in detail, they can be implemented or understood by referring to the prior art by those skilled in the art. If the manufacturer of all reagents or instruments is not specified, it is considered that the product is a conventional product that can be purchased on the market.

[0025] Example 1 Preparation of 2-bromoterephthalic acid di-tert-butyl ester (B)

[0026] 2-bromoterephthalic acid (4.0 g, 16.4 mmol), (Boc)2O (10.7 g, 49.2 mmol) and DMAP (1.0 g, 8.2 mmol) were weighed and dissolved in dichloromethane (80 mL) to form a solution, which was stirred at room temperature overnight. The reaction solution was washed with H2O (3x30 mL), dried over anhydrous Na2SO4, filtered and concentrated. The crude product was purified by column chromatography (PE elution 200-300 mesh neutral alumina) to obtain 2-bromoterephthalic acid di-tert-butyl ester (5.38 g, 92.1%) as a colorless liquid. 1H NMR (300 MHz, DMSO-d6): 8.06 (d, 1 H, J = 1.2 Hz), 7.90 (dd, 1 H, Ji = 1.5 Hz, J2= 7.8 Hz), 7.71 (d, 1 H, J = 8.1 Hz), 1.54 (s, 9 H), 1.53 (s, 9 H). 13 C NMR (100 MHz, DMSO-d6): 165.15, 163.27, 138.45, 134.88, 134.01, 130.67, 128.58, 119.83, 83.33, 82.36, 28.05, 28.04. HR-MS m / z calcd. For C 16 H 21 BrO4[M+Na] + : 379.0515, found [M+Na] + : 379.0519.

[0027] Example 2 Preparation of di-tert-butyl 2-cyanoterephthalate (c)

[0028] Di-tert-butyl 2-bromoterephthalate (3.24 g, 9.1 mmol) was dissolved in 60 mL of DMF and copper cyanide (1.63 g, 18.2 mmol) was added. The reaction was heated at 110 °C overnight under Ar2and then cooled to room temperature. Petroleum ether (120 mL) was added and the organic phase was washed with saturated brine (3 x 50 mL). The organic layer was dried over anhydrous sodium sulfate, filtered and concentrated to give di-tert-butyl 2-cyanoterephthalate (2.37 g, 88.8%) as a white solid. 1 H NMR (300 MHz, DMSO-d6): 8.30 (d, 1 H, J = 1.2 Hz), 8.25 (dd, 1 H, Ji = 1.8 Hz, J2= 8.1 Hz), 8.15 (d, 1 H, J = 8.1 Hz), 1.59 (s, 9 H), 1.57 (s, 9 H). 13 C NMR (100 MHz, DMSO-d6): 162.98, 162.60, 136.93, 135.41, 135.27, 133.72, 131.70, 117.15, 112.32, 84.10, 82.97, 28.03, 27.97. HR-EI-MS m / z calcd. For C 17 H 21 NO4[M+H] + : 304.1543, found [M+H] + : 304.1541.

[0029] Preparation of 2-(N'-hydroxy carbamoyl)terephthalic acid di-tert-butyl ester (D)

[0030] A suspension of 2-cyanoterephthalic acid di-tert-butyl ester (2.00 g, 6.6 mmol), NH2OH HCI (1.38 g, 19.8 mmol) and Et3N (2.75 mL, 19.8 mmol) in i-PrOH (40 mL) was heated at 60 °C for 7 h. The i-PrOH was removed by rotary evaporation and the residue was dissolved in EA and washed with H2O (3 x 50 mL) and dried over anhydrous Na2S04. The filtrate was concentrated to give a crude product which was purified by column chromatography (200-300 mesh silica gel, eluted with 5% EA / PE) to give 2-(N'-hydroxy carbamoyl)terephthalic acid di-tert-butyl ester (1.20 g, 54.1%) as a white solid. 1 H NMR (300 MHz, DMSO-d6): 9.57 (s, 1H), 7.96-7.93 (m, 2H), 7.65 (d, 1H, J = 8.7 Hz), 5.89 (s, 2H), 1.56 (s, 9H), 1.48 (s, 9H). 13 C NMR (100 MHz, DMSO-d6): 166.89, 164.46, 151.51, 137.66, 134.54, 133.09, 129.99, 129.55, 129.13, 81.97, 81.90, 28.20, 28.10. HR-ESI-MS m / z calcd. For C 17 H 24 N2O5[M+H] + : 337.1758, found [M+H] + : 337.1760.

[0031] Preparation of 2-(N'-hydroxy carbamoyl)terephthalic acid (I)

[0032] 2-(N'-hydroxy carbamoyl)terephthalic acid di-tert-butyl ester (0.30 g, 0.9 mmol) was added to a mixture of CF3COOH (6 mL) and DCM (30 mL) and stirred at room temperature until TLC showed the reaction was complete. The solvent was removed by rotary evaporation and the residue was washed with DCM and dried in vacuum to give 2-(N'-hydroxy carbamoyl)terephthalic acid (0.20 g, 98.3%) as a white solid. 1H NMR (300 MHz, DMSO-d6): 13.68 (br, 2H), 11.24 (s, 1H), 9.03 (s, 2H), 8.27 (d, 1H, J = 8.1 Hz), 8.17 (d, 1H, J = 8.1 Hz), 8.03 (s, 1H). 13 C NMR (100 MHz, DMSO-d6): 166.05, 165.80, 160.16, 134.89, 134.60, 132.97, 131.61, 131.09, 128.32. HR-ESI-MS m / z calcd for C9H s N2O5[M+H] + : 225.0506, found [M+H] + : 225.0504.

[0033] Example 5 Preparation of Amidoxime functionalized metal-organic frameworks (MOFs)

[0034] ZrCl4(0.20 g, 0.86 mmol), glacial acetic acid (3.81 mL) and 2-(N'-hydroxy carbamoyl)terephthalic acid (0.19 g, 0.86 mmol) were added to 24 mL of DMF. After sonication for 0.5 h, the mixture was heated at 120 °C for 24 h. After cooling to room temperature, the reaction mixture was centrifuged at 8000 rpm for 5 min, washed with DMF and MeOH, and dried in vacuum to obtain the amidoxime functionalized metal-organic framework.

[0035] Example 6 Preparation of Amidoxime functionalized metal-organic frameworks (MOFs)

[0036] ZrOCl2.8H2O (0.28 g, 0.86 mmol), glacial acetic acid (3.81 mL) and 2-(N'-hydroxy carbamoyl)terephthalic acid (0.19 g, 0.86 mmol) were added to 24 mL of DMF. After sonication for 0.5 h, the mixture was heated at 120 °C for 24 h. After cooling to room temperature, the reaction mixture was centrifuged at 8000 rpm for 5 min, washed with DMF and MeOH, and dried in vacuum to obtain the amidoxime functionalized metal-organic framework.

[0037] Example 7 Preparation of Amidoxime functionalized metal-organic frameworks (MOFs)

[0038] ZrCI4(0.10 g, 0.43 mmol), ZrOCl2.8H2O (0.14 g, 0.43 mmol), trifluoroacetic acid (4.95 mL), and 2-(N'-hydroxy carbamoyl)terephthalic acid (0.19 g, 0.86 mmol) were added to 24 mL of DMF. After sonication for 0.5 h, the mixture was heated at 120 °C for 24 h. After cooling to room temperature, the reaction mixture was centrifuged at 8000 rpm for 5 min, washed with DMF and MeOH, and dried in vacuum to yield the amidoxime-functionalized metal-organic framework material.

[0039] Example 8 Preparation of amidoxime-functionalized metal-organic framework materials (MOFs)

[0040] ZrCI4(0.20 g, 0.86 mmol), H2O (12 mL), and 2-(N'-hydroxy carbamoyl)terephthalic acid (0.19 g, 0.86 mmol) were added to 12 mL of DMF. After sonication for 0.5 h, the mixture was heated at 120 °C for 24 h. After cooling to room temperature, the reaction mixture was centrifuged at 8000 rpm for 5 min, washed with DMF and MeOH, and dried in vacuum to yield the amidoxime-functionalized metal-organic framework material.

[0041] Example 9 Preparation of amidoxime-functionalized metal-organic framework materials (MOFs)

[0042] ZrCI4(0.20 g, 0.86 mmol), H2O (12 mL), and 2-(N'-hydroxy carbamoyl)terephthalic acid (0.19 g, 0.86 mmol) were added to 12 mL of DMF. After sonication for 0.5 h, the mixture was heated at 120 °C for 24 h. After cooling to room temperature, the reaction mixture was centrifuged at 8000 rpm for 5 min, washed with DMF and MeOH, and dried in vacuum to yield the amidoxime-functionalized metal-organic framework material.

[0043] Example 10 Preparation of amidoxime-functionalized metal-organic framework materials (MOFs)

[0044] ZrCI4(0.20 g, 0.86 mmol), H2O (12 mL), and 2-(N'-hydroxy carbamoyl)terephthalic acid (0.19 g, 0.86 mmol) were added to 12 mL of DMF. After sonication for 0.5 h, the mixture was heated at 120 °C for 24 h. After cooling to room temperature, the reaction mixture was centrifuged at 8000 rpm for 5 min, washed with DMF and MeOH, and dried in vacuum to yield the amidoxime-functionalized metal-organic framework material.

[0045] Example 10 Scanning Electron Microscope (SEM) determination of amine oxime functionalized metal-organic framework material MOFs

[0046] Figure 1 is a SEM image of the amine oxime functionalized metal-organic framework material prepared in Example 5 of the present invention. As shown in Figure 1 the material exhibits a nanoparticulate morphology.

Claims

1. A compound of formula I: ###0001### Formula I 2. A method of preparing an amido-hydroxamic acid functionalized metal-organic framework material, characterized in that, The metal-organic framework material is directly synthesized via solvothermal reaction of a compound of claim 1 as ligand and a zirconium salt.

3. The method of claim 2, wherein The zirconium salt is a water-soluble zirconium salt.

4. The method of claim 3 wherein The water-soluble zirconium salt is at least one selected from ZrCl4, ZrOCl2-8H2O.

5. The method of claim 2, wherein The solvent is H2O, DMF.

6. The method of claim 5, wherein The volume ratio of H2O, DMF is (0-1):

1.

7. The method of claim 5, wherein The H2O / DMF mixed solution further comprises an acid regulator, wherein the acid regulator is acetic acid, hydrochloric acid, trifluoroacetic acid.

8. The method of claim 7, wherein The volume ratio of the H2O / DMF mixed solution, acid regulator is 1:(0-1).

9. The method of claim 2 wherein The solvothermal reaction temperature is 95-150°C, and the reaction time is 12h-5d.

10. A method for preparing the compound of claim 1, comprising the following steps: (1) reacting compound A with di-tert-butyl dicarbonate and 4-dimethylaminopyridine to obtain compound B; (2) reacting compound B with cuprous cyanide to obtain compound C; (3) reacting compound C with hydroxylamine to obtain compound D; (4) removing Boc from compound D under acidic conditions to obtain compound I.

11. The method for preparing the compound of claim 9, wherein step (1) can also use the following method: reacting compound A with tert-butyl alcohol and concentrated hydrochloric acid to obtain compound B.

12. The method for preparing the compound of claim 9, wherein: the reaction with hydroxylamine in step (3) comprises hydroxylamine hydrochloride and a base system, hydroxylamine hydrochloride aqueous solution; wherein the base is selected from any one or combination of several of triethylamine, sodium bicarbonate, and sodium carbonate; the reaction in step (4) is carried out under acidic conditions, wherein the acid is selected from any one or combination of several of trifluoroacetic acid, hydrochloric acid, hydrobromic acid, and sulfuric acid.

13. A composition characterized in that, one or several of the compounds of formula C, D, I of claim 10.

14. Use of the compound of claim 1 in the preparation of a metal-organic framework material.

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