阅读说明：本技术 一种Ni的金属-有机骨架材料及其制备方法和用途 (Ni metal-organic framework material and preparation method and application thereof ) 是由 李亚平 张晓霞 于 2021-07-23 设计创作，主要内容包括：一种Ni的金属-有机骨架材料及其制备方法和用途,属于晶态材料技术领域。所述金属-有机骨架材料的化学分子式为[Ni(HDBPC)(H-(2)O)-(2)],其中H-(3)DBPC为有机配体3,5-二(1H-吡唑-4-基)-[1,1’-联苯]-4-羧酸。该金属-有机骨架材料的制备方法：封闭条件下,有机配体3,5-二(1H-吡唑-4-基)-[1,1’-联苯]-4-羧酸与氯化镍在N,N-二甲基甲酰胺和水的混合溶液中,经由溶剂热反应得到金属有机骨架材料的晶体。该金属-有机骨架材料在分子磁学和催化等方面具有潜在的应用价值。(A Ni metal-organic framework material, a preparation method and application thereof, belonging to the technical field of crystalline materials. The chemical molecular formula of the metal-organic framework material is [ Ni (HDBPC)) (H 2 O) 2 ]In which H is 3 DBPC is an organic ligand 3, 5-di (1H-pyrazol-4-yl) - [1, 1' -biphenyl]-4-carboxylic acid. The preparation method of the metal-organic framework material comprises the following steps: under the closed condition, the organic ligand 3, 5-di (1H-pyrazol-4-yl) - [1, 1' -biphenyl]And (3) carrying out solvothermal reaction on the 4-carboxylic acid and nickel chloride in a mixed solution of N, N-dimethylformamide and water to obtain crystals of the metal organic framework material. The metal-organic framework material has the advantages of molecular magnetism, catalysis and the likeHas potential application value.)

1. A pyrazole carboxylic acid organic ligand having the structural formula:

2. the process for the preparation of pyrazolecarboxylic acid organic ligands according to claim 1, comprising the steps of:

firstly, (3, 5-dibromophenyl) boric acid reacts with 4-iodomethyl benzoate to obtain 3, 5-dibromo- [1, 1' -biphenyl ] -4-carboxylic ester;

adding the 3, 5-dibromo- [1,1 '-biphenyl ] -4-carboxylic ester obtained in the last step, 1- (4-methoxybenzyl) -pyrazole boric acid ester, potassium carbonate, tetrakis (triphenylphosphine) palladium and 1, 4-dioxane into a reactor, sealing, vacuumizing, protecting by inert gas, and heating to react to obtain 3, 5-bis (1- (4-methoxybenzyl) -1H-pyrazol-4-yl) - [1, 1' -biphenyl ] -4-carboxylic ester;

finally, carrying out reflux reaction on 3, 5-bis (1- (4-methoxybenzyl) -1H-pyrazol-4-yl) - [1, 1' -biphenyl ] -4-carboxylic acid ester and ethanol solution of hydrochloric acid; after the reaction is finished, the mixture is further hydrolyzed in a mixed solution of sodium hydroxide, water, methanol and tetrahydrofuran, and the 3, 5-di (1H-pyrazol-4-yl) - [1, 1' -biphenyl ] -4-carboxylic acid is obtained by suction filtration.

3. The Ni metal-organic framework material based on the triangular pyrazole carboxylic acid ligand is characterized in that the chemical formula is [ Ni (HDBPC)) (H₂O)₂]，H₃DBPC is 3, 5-di (1H-pyrazol-4-yl) - [1, 1' -biphenyl]-4-carboxylic acid; the crystal structure of the metal-organic framework material belongs to a monoclinic system, the space group is C2/C, and the unit cell parameters are as follows: α＝γ＝90°,β＝93°。

4. a metal-organic framework material based on Ni as a ligand of triangular pyrazolecarboxylic acid according to claim 3, characterized in that each Ni in the metal-organic framework material²⁺And 2 axial O atoms in water molecules and 4 pyrazolyl N atoms from different ligands are coordinated to form an octahedral configuration; with 2 metals Ni attached per ligand²⁺The pyrazolyl group of the ligand is connected with Ni in a coordination mode of mu 1-eta 1: eta 0²⁺(ii) a The metal-organic framework is formed by the N atoms of two different pyrazoles on the same ligand and the metalA one-dimensional chain structure.

5. The process for the preparation of a Ni metal-organic framework material based on triangular pyrazole carboxylic acid ligands according to claim 3, characterized in that the organic ligand 3, 5-bis (1H-pyrazol-4-yl) - [1, 1' -biphenyl ] is used under hermetic conditions]-4-Carboxylic acid with NiCl₂·6H₂And carrying out solvothermal reaction on the O in a mixed solution of N, N-dimethylformamide and deionized water to obtain the metal-organic framework crystal.

6. The method according to claim 5, wherein the molar ratio of the organic ligand 3, 5-bis (1H-pyrazol-4-yl) - [1, 1' -biphenyl ] -4-carboxylic acid to the nickel chloride is 1:1 to 3, 1 to 4mL of N, N-dimethylformamide and 0.1 to 1.6mL of deionized water are used per 0.03mmol of nickel chloride, and the thermal reaction is carried out at a temperature of 80 to 150 ℃ for 12 to 48 hours.

7. Use of a metal-organic framework material according to claim 3 or 4 as a catalyst in a carbon dioxide cycloaddition reaction.

Technical Field

The invention relates to a crystalline material, in particular to a metal-organic coordination polymer material, and specifically belongs to a metal-organic framework material of Ni based on a triangular pyrazole carboxylic acid ligand, and a preparation method and application thereof.

Background

Fossil energy not only causes environmental pollution, but also causes global warming due to excessive emission of carbon dioxide. To address this challenge, the exploration of renewable/clean energy and the reuse of carbon dioxide are of interest to global scientists, whereCarbon capture, energy-related small molecule activation and CO₂Resource utilization has been a hot spot of chemists. Metal-organic frameworks (MOFs) have received a great deal of attention from researchers because of their high specific surface area, their potential applications in gas adsorption and storage, catalysis, etc., their attractive structures and diverse topological configurations. The metal-organic framework is a crystalline porous material with a periodic network structure, which is constructed by self-assembly of inorganic metal nodes (metal clusters) and organic ligand connectors. The structure and synthesis scheme of MOFs is more flexible to design and regulate than other porous compounds.

Pyrazole carboxylic acid ligands can provide multiple coordination sites including both pyrazole and carboxylic acid and can form different coordination modes; the ligand has a carboxyl group and two pyrazolyl groups, so that different metal cluster units can be formed with NI-ions in the process of synthesizing MOFs. The method not only can increase the stability of the coordination polymer framework structure, but also can strengthen the complex framework and CO₂The interaction of the gases can be used as a catalyst to catalyze CO₂The cycloaddition reaction has certain application value.

Disclosure of Invention

The invention aims to provide a Ni metal-organic framework material based on a triangular pyrazole carboxylic acid ligand, and a preparation method and application thereof.

The invention relates to a Ni metal-organic framework material based on a triangular pyrazole carboxylic acid ligand, which is characterized in that the chemical molecular formula is [ Ni (HDBPC)) (H₂O)₂]，H₃DBPC is an organic ligand 3, 5-di (1H-pyrazol-4-yl) - [1, 1' -biphenyl]-4-carboxylic acid.

From the perspective of framework connection construction, the crystal structure of the metal-organic framework belongs to a monoclinic system, space group is C2/C, unit cell parameters are:α＝γ＝90°,β＝93°。

in the metal-organic framework, each Ni²⁺And 2 axial O atoms in water molecules and 4 pyrazolyl N atoms from different ligands are coordinated to form an octahedral configuration; with 2 metals Ni attached per ligand²⁺The pyrazolyl group of the ligand is connected with Ni in a coordination mode of mu 1-eta 1: eta 0²⁺(ii) a The metal-organic framework forms a one-dimensional chain structure with metal through N atoms on two different pyrazoles on the same ligand.

From the topological viewpoint, when the metal and the pyrazolecarboxylic acid ligand in the metal-organic skeleton are simplified into nodes, the metal-organic skeleton can be simplified into a four-linked chain structure, and the schleffle symbol (c) issymbol) is (4 ·²)(4)₂Belonging to a topology of the type ttd.

Wherein the triangular pyrazole carboxylic acid ligand is 3, 5-di (1H-pyrazol-4-yl) - [1, 1' -biphenyl]-4-carboxylic acid (H)₃DPBC), the chemical formula is shown below:

the ligand simultaneously contains two functional groups of pyrazole and carboxylic acid; the included angle between benzoic acid in the ligand and two pyrazole rings is 120 degrees, and the included angle between the two pyrazole rings is 120 degrees.

The invention discloses a synthesis method of a triangular pyrazole carboxylic acid ligand, which comprises the following steps:

firstly, reacting (3, 5-dibromophenyl) boric acid with 4-iodomethyl benzoate to obtain 3, 5-dibromo- [1, 1' -biphenyl ] -4-carboxylic ester;

adding the 3, 5-dibromo- [1,1 '-biphenyl ] -4-carboxylic ester obtained in the last step, 1- (4-methoxybenzyl) -pyrazole boric acid ester, potassium carbonate, palladium tetratriphenylphosphine and 1, 4-dioxane into a reactor, sealing, vacuumizing, protecting by inert gas, and heating to react to obtain 3, 5-bis (1- (4-methoxybenzyl) -1H-pyrazol-4-yl) - [1, 1' -biphenyl ] -4-carboxylic ester;

finally, carrying out reflux reaction on 3, 5-bis (1- (4-methoxybenzyl) -1H-pyrazol-4-yl) - [1, 1' -biphenyl ] -4-carboxylic acid ester and ethanol solution of hydrochloric acid; after the reaction is finished, the product is further hydrolyzed in sodium hydroxide, water, methanol and tetrahydrofuran, and the 3, 5-di (1H-pyrazol-4-yl) - [1, 1' -biphenyl ] -4-carboxylic acid is obtained by suction filtration.

The synthesis method of the metal-organic framework material comprises the following steps:

under sealed condition, organic ligand 3, 5-di (1H-pyrazol-4-yl) - [1, 1' -biphenyl]-4-carboxylic acid (H)₃DPBC) and nickel chloride (NiCl)₂·6H₂O) in a mixed solution of N, N-dimethylformamide and deionized water, and obtaining the crystal of the metal-organic framework material through solvothermal reaction.

Wherein the organic ligand is 3, 5-di (1H-pyrazol-4-yl) - [1, 1' -biphenyl]-4-carboxylic acid (H)₃DPBC) and nickel chloride in a molar ratio of 1 (1-3), wherein each 0.03mmol of nickel chloride corresponds to 1-4 mL of N, N-dimethylformamide and 0.1-1.6 mL of deionized water, the temperature of the thermal reaction is 80-150 ℃, and the reaction time is 12-48 hours.

Compared with the prior art, the invention has the beneficial effects that: the organic ligand synthesized by the invention belongs to a novel triangular pyrazole carboxylic acid ligand, the metal-organic framework material prepared by the invention has good stability, and the material shows good catalytic performance in the cycloaddition reaction of propylene oxide and carbon dioxide, thereby showing that the material has potential application value in the aspects of molecular magnetism, catalysis and the like.

Drawings

FIG. 1 is a synthesis scheme of pyrazolecarboxylic acid ligands for synthesizing the metal-organic framework materials.

FIG. 2 shows Ni in the metal-organic framework²⁺And (4) an ion coordination environment diagram.

Fig. 3 is a one-dimensional chain diagram of the metal-organic framework.

Fig. 4 is a topological diagram of the metal-organic framework.

Detailed Description

The present invention will be further illustrated with reference to the following examples, but the present invention is not limited to the following examples.

Example 1

5.00g (17.87mmol) of (3, 5-dibromophenyl) boric acid, 16.66g (63.58mmol) of methyl 4-iodobenzoate, 11.72g (84.78mmol) of potassium carbonate, 0.60g (0.517mmol) of tetratriphenylphosphine palladium and 320mL of 1, 4-dioxane are added into a 500mL three-necked flask, and the mixture is sealed, vacuumized and protected by nitrogen and reacted at 80 ℃ for 12 hours. After completion of the reaction, extraction with ethyl acetate, washing with water, drying over anhydrous sodium sulfate, filtration and distillation under reduced pressure gave 4.5g (12.16mmol) of 3, 5-dibromo- [1, 1' -biphenyl ] -4-carboxylic acid ester.

4.5g (12.16mmol) of 3, 5-dibromo- [1, 1' -biphenyl obtained in the above step]-4-carboxylate and 10.62g (54.72mmol)1- (4-methoxybenzyl) -pyrazole borate, 6.72g (48.64mmol) potassium carbonate, 0.60g (0.517mmol) tetratriphenylphosphine palladium, 320mL ethylene glycol dimethyl ether were added to a 500mL three-necked flask, sealed, evacuated and protected with nitrogen, and reacted at 100 ℃ for 24 hours. After the reaction is finished, extracting by dichloromethane, washing by water, drying by anhydrous sodium sulfate, filtering, distilling under reduced pressure, and separating and purifying by silica gel column chromatography to obtain 3, 5-bis (1- (4-methoxybenzyl) -1H-pyrazol-4-yl) - [1, 1' -biphenyl]4.48g of an (E) -4-carboxylic acid ester was obtained in a yield of 72%.¹H NMR(DMSO-d₆,400MHz):δ＝8.16(s,1H),8.14(m,1H),7.99(s,2H),7.92(s,2H),7.72(s,2H),7.64(s,1H),7.59(s,2H),5.52(s,6H),3.90(s,3H)。

Finally 4.48g of 3, 5-bis (1- (4-methoxybenzyl) -1H-pyrazol-4-yl) - [1, 1' -biphenyl]-4-carboxylate, 200mL of ethanolic hydrogen chloride solution was added to a 500mL three-necked flask and reacted under reflux for 24 hours. After the reaction is finished, carrying out reduced pressure distillation, adding 100mL of deionized water, dropwise adding ammonia water until no precipitation at the bottom of the precipitate occurs, carrying out suction filtration to obtain a solid, continuously adding 100mL of water, methanol and tetrahydrofuran respectively, stirring 5.00g of NaOH in a 500mL round-bottom flask, reacting for 6 hours under the reflux condition, adding concentrated hydrochloric acid until no precipitation at the bottom of the precipitate occurs, and carrying out suction filtration to obtain a solid 3, 5-bis (1H-pyrazol-4-yl) - [1, 1' -biphenyl]-4-carboxylic acid.¹H NMR(DMSO-d₆,400MHz):δ＝8.38(s,4H),8.05(d,2H),7.97(d,2H),7.95(d,1H),7.84(d,2H)。

Example 2

Organic ligand H₃Mixing DPBC (0.01mmol) with nickel chloride (0.03mmol) in 2.00mL of N, N-dimethylformamide and 0.6mL of deionized waterMixing the mixed solution uniformly, and sealing in a small bottle. The crystals of the metal-organic framework are obtained via a thermal reaction at 100 ℃ for 36 hours.

Example 3

Organic ligand H₃DPBC (0.02mmol) and nickel chloride (0.05mmol) were mixed well in a mixed solution of 2.00mL of N, N-dimethylacetamide and 0.80mL of deionized water, and sealed in a vial. Crystals of the metal-organic framework were obtained via a thermal reaction at 135 ℃ for 18 hours.

The test results of the products obtained in the above examples are the same, and specifically the following are given:

(1) determination of crystal structure:

selecting powder with proper size, and collecting data by using a PANALYtic X' Pert PRO high-resolution powder diffractometer at 253K. Data collection Using Mo-Ka monochromated by graphite monochromatorA target ray. Data absorption correction was done using SCALE3 absack software. The crystal structure was resolved by direct methods using the program SHELXTL-97. Firstly, determining all non-hydrogen atom coordinates by using a difference function method and a least square method, obtaining the hydrogen atom position by using a theoretical hydrogenation method, and then refining the crystal structure by using SHELXTL-97. The structure is shown in fig. 2 to 4. The crystallographic data are shown in table 1.

TABLE 1 crystallography data for metal organic framework materials

The carboxylic acid pyrazole ligand synthesis scheme of figure 1 shows: firstly, (3, 5-dibromophenyl) boric acid reacts with 4-iodomethyl benzoate to obtain 3, 5-dibromo- [1, 1' -biphenyl ] -4-carboxylic ester; secondly, reacting the obtained product with 1- (4-methoxybenzyl) -pyrazole borate to obtain 3, 5-bis (1- (4-methoxybenzyl) -1H-pyrazol-4-yl) - [1,1 ' -biphenyl ] -4-carboxylic ester, and finally removing a protecting group of the 3, 5-bis (1- (4-methoxybenzyl) -1H-pyrazol-4-yl) - [1,1 ' -biphenyl ] -4-carboxylic ester and hydrolyzing to obtain the 3, 5-bis (1H-pyrazol-4-yl) - [1,1 ' -biphenyl ] -4-carboxylic acid.

The block diagram of fig. 2 shows: in this metal-organic framework the ligand is linked to the metal via the N atoms on the two pyrazoles, the carboxyl groups of which are not deprotonated.

The block diagram of fig. 3 shows: in the metal-organic framework, a ligand is connected with a central metal and extends along the direction of an a axis to form a one-dimensional chain pattern.

The block diagram of fig. 4 shows: ligands and central metals can be simplified to a four-junction topology in the metal-organic framework.

Example 4

Experiment on catalytic performance of metal-organic framework material on carbon dioxide cycloaddition

Table 2 comparison of the amounts of different catalysts for catalyzing CO₂Cycloaddition reaction with propylene oxide^a

Serial number	[Ni]: [ catalyst]	Reaction time (h)	Conversion rate/%
				1	1:0	6	0
2	1:1	6	11.3
				3	1:2	6	32.5
4	1:5	6	56.8
				5	1:10	6	76.5
6	1:20	6	80.1

a reaction condition: m (catalyst) 60 μmol, n (ethylene oxide)/n (nickel complex) 1:0, 1:1, 1:2, 1:5, 1:10, 1:20, CO₂＝2MPa。