A layered metal-organic framework material, preparation method and application

Abstract

A layered metal-organic framework material, a preparation method and an application, belonging to the technical field of crystalline materials. The chemical formula is [Zr6(μ3-O)4(μ3-OH)4(OH)4(H2O)4(HPCDA)4], wherein the organic ligand (H3PCDA) is 4,4'-(9-(1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl) dibenzoic acid. The synthesis of this metal-organic framework is carried out under closed conditions. The organic ligand 4,4'-(9-(1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl) dibenzoic acid and a zirconium salt are in an organic solvent, and metal-organic framework material crystals are obtained through a solvothermal reaction; this metal-organic framework material has certain chemical stability. Due to its large pore size and specific surface area, this metal-organic framework material is expected to become a new material for SO2 capture.

Description

Technical Field

[0001] The technology of the present invention relates to metal-organic coordination polymer materials and belongs to the technical field of crystalline materials. Specifically, it relates to a layered metal-organic framework material, a corresponding preparation method and applications. Background Art

[0002] As a new type of organic-inorganic porous material, Metal-Organic Frameworks (MOFs), due to their characteristics such as diverse structures, adjustable sizes, and large specific surface areas, have been widely applied in fields such as gas storage and separation, water treatment, fluorescence detection, and catalysis. The diverse secondary building units (SBUs) and organic ligands make the controllable synthesis of MOFs possible, and among them, the reasonable design and synthesis of organic ligands are effective means to achieve the diversification and functionalization of MOFs.

[0003] Single high-symmetry carboxylic acid or pyrazole ligands have been widely studied due to their wide variety and diverse structures. In recent years, scholars at home and abroad have constructed a series of representative MOFs using low-symmetry single carboxylic acid or pyrazole ligands, such as NU-1000 and Co-BDP. The research on synthesizing metal-organic frameworks with low-symmetry carboxylic acid-pyrazole ligands is relatively less. Carboxylic acid-pyrazole ligands can coordinate with different metal ions or SBUs to construct metal-organic framework materials with large sizes.

[0004] Sulfur dioxide (SO2) is a harmful gas that endangers the environment and health. Therefore, reducing its emissions is crucial for environmental protection. Currently, there are various technologies available for removing SO2 from industrial waste gases. These technologies mainly include wet, semi-dry, and dry desulfurization technologies. Dry adsorption sulfur dioxide removal technology shows the potential to reduce energy consumption and waste generation. Although physical adsorbents such as porous carbon, zeolites, and porous organic polymers have been studied, they have certain limitations in treating trace (500–3000 ppm) SO2 because the selectivity of SO2 relative to CO2 and H2O is low. Metal-organic frameworks (MOFs) are potential materials for gas separation and purification. Some MOFs exhibit high SO2 adsorption capacities at atmospheric pressure, such as MFM-101 and MFM-170, but the MOF-SO2 binding is weak, which limits their performance under low-pressure conditions. In addition, the co-adsorption of moisture may reduce the SO2 adsorption capacity and even cause hydrolysis or degradation of MOFs. Therefore, although MOFs exhibit good adsorption characteristics, when treating trace SO2, it is necessary to solve the problem of the MOF-SO2 binding strength and the possible influence brought by moisture co-adsorption. Overcoming these challenges requires further research and development to make MOFs an efficient choice for treating trace SO2. Summary of the Invention

[0005] The object of the present invention is to provide a layered metal-organic framework material, a corresponding preparation method and an application

[0006] The first object of the present invention is to provide a layered metal-organic framework material based on a bifunctional ligand Zr. The chemical molecular formula of the metal-organic framework material is [Zr6(μ3-O)4(μ3-OH)4(OH)4(H2O)4(HPCDA)4], where Zr6 is an ion cluster; μ3-O / μ3-OH are bridging oxygen atoms on the Zr6 cluster; OH / H2O are hydroxide ions / water molecules on the Zr6 cluster; HPCDA is 4,4'-(9-(1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl) dibenzoate ion.

[0007] On the basis of the above solution, further, from the perspective of framework connection construction, the crystal structure of the layered metal-organic framework material is tetragonal system, the space group is P42 / nmc, and the unit cell parameters are:

[0008] On the basis of the above solution, further, there are two types of Zr with different connection relationships in the metal-organic framework material 4+ , where the first Zr 4+ coordinates with four O atoms from different ligands, two μ3-O and two μ3-OH; the second Zr 4+ coordinates with two O atoms from different ligands, two μ3-O, two μ3-OH, one terminal OH and one terminal H2O; three first Zr 4+ and three second Zr 4+ form a Zr6 cluster through μ3-O and μ3-OH entities.

[0009] On the basis of the above solution, further, in the metal-organic framework material, each HPCDA stacks face-to-face with adjacent HPCDA through π…π interactions between benzene rings (the center distance is ). The connection between the Zr6 cluster and the HPCDA ligands paired in a face-to-face manner forms a two-dimensional (2D) layer, which is a sql topological network.

[0010] On the basis of the above solution, further, the metal-organic framework is composed of a two-dimensional layered structure and stacks in a parallel manner into an interdigitated bilayer, thereby generating a three-dimensional (3D) overall structure as shown in Figure 3 (a).

[0011] On the basis of the above solution, further, the metal-organic framework material has octahedral polygonal cavities along the a and b axis directions, and the side lengths of the cavities are 8.91, 15.39 and , see Figure 3 (b).

[0012] The second object of the present invention is to provide a novel bifunctional ligand 4,4'-(9-(1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl) dibenzoic acid (abbreviated as H3PCDA) and a corresponding preparation method.

[0013] The central core of the ligand is carbazole, which is connected to the first benzoic acid, the second benzoic acid, and pyrazole. The angle between the first dotted line formed by the extension of the first benzoic acid towards the carbazole direction and the second dotted line formed by the extension of the second benzoic acid towards the carbazole direction is 90°. The angles between the pyrazole and the first dotted line and the second dotted line are independently 135°. The specific structural formula of the H3PCDA is as follows:

[0014]

[0015] On the basis of the above scheme, further, the preparation method of the H3PCDA,

[0016]

[0017] Specifically, it includes the following four steps:

[0018] Step S1, mix 3,6-dibromo-9H-carbazole, 4-iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole, cesium carbonate, lithium chloride, copper(I) iodide, and N,N-dimethylformamide, and under the conditions of an inert atmosphere, a pressure of 0.1 - 0.3 MPa, a temperature of 80 - 110 °C, and a time of 24 - 48 h, obtain 3,6-dibromo-9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole; the weight ratio of the 3,6-dibromo-9H-carbazole, the 4-iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole, the cesium carbonate, the lithium chloride, and the copper(I) iodide is 20.0:(18.1 - 20.7):(18.7 - 21.6):(5.4 - 7.4):(0.6 - 0.8); the concentration of the 3,6-dibromo-9H-carbazole in the N,N-dimethylformamide is 60 - 70 g / L;

[0019] Step S2: Mix the 3,6-dibromo-9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole, 4-(methoxycarbonyl)phenyl)boronic acid, potassium carbonate, tetrakis(triphenylphosphine)palladium, and 1,4-dioxane. Under the conditions of an inert atmosphere, a pressure of 0.1 - 0.3 MPa, a temperature of 80 - 100 °C, and a time of 12 - 24 h, obtain dimethyl 4,4'-(9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl)dibenzoate; the weight ratio of the 3,6-dibromo-9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole, the 4-(methoxycarbonyl)phenyl)boronic acid, the potassium carbonate, and the tetrakis(triphenylphosphine)palladium is 15:(12.5 - 14.5):(13.1 - 14.4):(3.7 - 4.6), and the concentration of the 3,6-dibromo-9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole in 1,4-dioxane is 60 - 65 g / L;

[0020] Step S3: Reflux the dimethyl 4,4'-(9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl)dibenzoate in a hydrochloric acid ethanol solution with a concentration of 2 M for 8 - 12 h, then add deionized water, adjust the pH to 8 - 10 to completely precipitate the precipitate, and then perform suction filtration to obtain methyl 4-(3,6-bis(1H-pyrazol-4-yl)-9H-carbazole-9-yl)benzoate; the concentration of the dimethyl 4,4'-(9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl)dibenzoate in the hydrochloric acid ethanol solution is (30 - 40) g / L; the volume ratio of the hydrochloric acid ethanol solution to the deionized water is 1:1 - 1:3;

[0021] Step S4: Reflux the methyl 4-(3,6-bis(1H-pyrazol-4-yl)-9H-carbazole-9-yl)benzoate in potassium hydroxide, tetrahydrofuran, methanol, and deionized water for 8 - 12 h, then adjust the pH to 6 - 8 to completely precipitate the precipitate, and then perform suction filtration to obtain the ligand; the weight ratio of the methyl 4-(3,6-bis(1H-pyrazol-4-yl)-9H-carbazole-9-yl)benzoate to the potassium hydroxide is 2.1:(3.0 - 5.0), the concentration of the methyl 4-(3,6-bis(1H-pyrazol-4-yl)-9H-carbazole-9-yl)benzoate in the tetrahydrofuran is 23 - 35 g / L, and the volume ratio of the tetrahydrofuran, the methanol, and the deionized water is 1:(1 - 1.5):(1 - 1.5).

[0022] The third object of the present invention is to provide a method for preparing a layered metal-organic framework material.

[0023] Under the conditions of an inert atmosphere, a pressure of 0.1-0.5 MPa, a temperature of 80-135 °C, and a time of 12-48 h, a ligand, a metal salt, and a solvent are mixed and reacted to obtain the layered metal-organic framework material. The metal salt is selected from one or more of zirconium tetrachloride and zirconyl chloride octahydrate; when the metal salts are zirconium tetrachloride and zirconyl chloride octahydrate, the molar ratio of zirconium tetrachloride to zirconyl chloride octahydrate is 1:(1-2); the solvent is water and an organic solvent, and the volume ratio of water to the organic solvent is (0.2-0.8):(1-4); preferably, the organic solvent is one or more of DMF, acetic acid, DMSO, and NMP; the molar ratio of the ligand to the metal salt is 1:(2-6); the concentration of the metal salt in the solvent is 0.04-0.15 mol / L.

[0024] The fourth object of the present invention is to provide an application of a layered metal-organic framework material in gas adsorption, especially in the adsorption and capture of SO2.

[0025] The beneficial technical effects of the present invention are as follows: 1. A layered metal-organic framework material based on a bifunctional ligand Zr and its synthesis method: It relates to a crystalline porous material, which is a layered metal-organic framework constructed based on a bifunctional ligand Zr. This material has a novel two-dimensional layered structure, and its advantages include a large specific surface area, high stability, etc. Its solvothermal synthesis method is simple and efficient and can be used to prepare this layered metal-organic framework material; 2. The design and synthesis of a bifunctional ligand: The present invention provides a novel bifunctional ligand, namely 4,4'-(9-(1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl) dibenzoic acid. The design of this ligand is not only unique in structure, but also the synthetic route for preparing the target compound from readily available starting materials through synthesis steps S1, S2, S3, and S4 is simple and efficient, and the yield is also relatively high; 3. The application of a layered metal-organic framework material based on a bifunctional ligand Zr in the adsorption and capture of SO2. This material exhibits a relatively high adsorption capacity for SO2 and the ability to capture trace amounts of SO2 under high humidity. This characteristic makes it have potential application value in the adsorption and capture of SO2.

[0026] The organic ligand synthesized in the present invention belongs to a novel pyrazole-carboxylic acid ligand. The metal-organic framework of the present invention has a novel structure, a stable framework, large pore sizes, and a large specific surface area, and has potential applications in SO2 capture. Description of the Drawings

[0027] Figure 1 1H nuclear magnetic resonance spectrum of this low-symmetry pyrazole-carboxylic acid ligand. 1 ​

[0028] Figure 2 It is the two-dimensional layered diagram of the metal-organic framework.

[0029] Figure 3 It is (a) the schematic diagram of the three-dimensional stacking structure of the metal-organic framework; (b) the schematic diagram of the octahedral polygon cavity in the metal-organic framework material.

[0030] Figure 4 It is the 77K nitrogen adsorption isotherm diagram of the metal-organic framework material after being treated under different conditions.

[0031] Figure 5 It is the SO2 adsorption isotherm diagram of the metal-organic framework material at 298K.

[0032] Figure 6 It is the capture effect diagram of trace SO2 in simulated flue gas by the metal-organic framework material. Detailed implementation mode

[0033] The present invention will be further described below in conjunction with embodiments, but the present invention is not limited to the following embodiments.

[0034] Embodiment 1

[0035] 20.0 g of 3,6-dibromo-9H-carbazole, 20.5 g of 4-iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole, 21.0 g of cesium carbonate, 6.3 g of lithium chloride, 0.7 g of copper(I) iodide and 300 mL of N,N-dimethylformamide were added to a 500 mL three-necked flask, and stirred and reacted at 100 °C for 48 h under a nitrogen atmosphere and a pressure of 0.1 MPa. After the reaction was completed, the mixture was cooled to room temperature and filtered, and 3,6-dibromo-9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole was obtained after silica gel purification.

[0036] The 15.0 g of 3,6-dibromo-9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole, 13.2 g of 4-(methoxycarbonyl)phenyl)boronic acid, 13.9 g of potassium carbonate, 3.9 g of tetrakis(triphenylphosphine)palladium(0) and 250 mL of 1,4-dioxane were added to a 500 mL three-necked flask, and stirred and reacted at 100 °C for 24 h under a nitrogen atmosphere and a pressure of 0.1 MPa. After the reaction was completed, the mixture was cooled to room temperature and filtered, and dimethyl 4,4'-(9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl)dibenzoate was obtained after silica gel purification.

[0037] Add 3.0 g of dimethyl 4,4'-(9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl)dibenzoate and 100 mL of 2 M hydrochloric acid ethanol solution to a 250 mL three-necked flask, and react under reflux for 24 hours. After the reaction stops, carry out vacuum distillation, then add 100 mL of deionized water, add ammonia water until no precipitate is formed, and then filter to obtain methyl 4-(3,6-bis(1H-pyrazol-4-yl)-9H-carbazol-9-yl)benzoate.

[0038] Add 2.1 g of methyl 4-(3,6-bis(1H-pyrazol-4-yl)-9H-carbazol-9-yl)benzoate, 3.0 g of potassium hydroxide, 60 mL of deionized water, 60 mL of tetrahydrofuran, and 60 mL of methanol to a 250 mL three-necked flask, and reflux and react at 70 °C for 24 hours. After the reaction stops, filter, dropwise add 2 M dilute hydrochloric acid to the filtrate until no precipitate settles out, then carry out suction filtration and dry to obtain 4,4'-(9-(1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl)dibenzoic acid, the 1 1H nuclear magnetic resonance spectrum is shown in Figure 1 . Figure 1 of the low-symmetry pyrazole-carboxylic acid ligand 1 The 1H nuclear magnetic resonance spectrum shows that the 4,4'-(9-(1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl)dibenzoic acid is obtained.

[0039] Example 2

[0040] Mix 0.02 mmol of the organic ligand H3PCDA with 0.08 mmol of ZrOCl2·8H2O evenly in 2.0 mL of N,N-dimethylformamide, add 0.1 mL of deionized water, and seal in a vial. Obtain the crystals of the metal-organic framework through a thermal reaction at 120 °C for 36 hours.

[0041] Example 3

[0042] Mix 0.02 mmol of the organic ligand H3PCDA with 0.12 mmol of ZrOCl2·8H2O evenly in 1.0 mL of N,N-dimethylformamide, add 0.4 mL of deionized water, and seal in a vial. Obtain the crystals of the metal-organic framework through a thermal reaction at 135 °C for 12 hours.

[0043] Example 4

[0044] The organic ligand H3PCDA (0.02 mmol) was mixed evenly with ZrOCl2·8H2O (0.04 mmol) in 0.5 mL of N,N-dimethylformamide, 0.25 mL of deionized water was added, and the mixture was sealed in a vial. The crystals of the metal-organic framework were obtained through a thermal reaction at 80 °C for 48 hours.

[0045] The test results of the products obtained in the above examples are the same, as shown below:

[0046] (1) Determination of crystal structure:

[0047] Single crystals of appropriate size obtained from Examples 2-4 were selected, and data were collected at 333 K using an Agilent Technologies SuperNova X-ray single crystal diffractometer. The data collection used Cu-Kα( ) target radiation monochromatized by a filter monochromator. The absorption correction of the data was completed using the SCALE3 ABSPACK software. The crystal structure was solved by direct methods using the SHELXTL-97 program. First, the coordinates of all non-hydrogen atoms were determined by the difference function method and the least squares method, and the positions of hydrogen atoms were obtained by theoretical hydrogenation. Then, the crystal structure was refined using SHELXTL-97. The crystallographic data are shown in Table 1.

[0048] Table 1 Crystallographic data of the metal-organic framework material

[0049]

[0050]

[0051] The crystal structure diagram of the metal-organic framework is shown in Figure 2 and Figure 3 . Figure 2 The structure diagram shows that the metal-organic framework is composed of a two-dimensional layered structure, which is an sql topological network and is stacked in a parallel manner into an interdigitated bilayer. Figure 3 The structure diagram shows that the cavities of the metal-organic framework material in the a and b axis directions have side lengths of 8.91, 15.39, and

[0052] (2) Stability characterization

[0053] The nitrogen adsorption curves of the metal-organic framework material were measured at 77 K after being soaked in different acid-base solutions. The operation steps were as follows: 100 mg of the activated newly synthesized material was taken and soaked in 0.01 M NaOH, 1 M HCl, 1 M H2SO4, and saturated H2SO3 (~1.5 M) solutions at room temperature for 24 h, and then the nitrogen adsorption curves were measured.

[0054] Figure 4 The nitrogen adsorption isotherm curves of the material were measured at 77 K after being soaked in different acid and base solutions. It can be seen that the material maintains a complete porosity in different acid and base solutions. The maximum N2 adsorption capacity of the material is 480 cm 3 ·g -1 , and the specific surface area calculated from it is 1682 m 2 g -1 .

[0055] (3) Characterization of SO2 adsorption and capture performance

[0056] The MOF powder sample (about 100 mg) was heated in 20 mL of DMF (containing 2 mL of concentrated hydrochloric acid) at 60 °C for 24 hours. Next, the DMF was decanted, and the sample was transferred to a Soxhlet extractor with refluxing methanol (300 mL) for activation for three days. After solvent exchange, the sample was collected by centrifugation and dried in air. Before the adsorption experiment, the air-dried sample was loaded into an adsorption tube and degassed at room temperature for 24 hours. The isotherms of SO2, CO2, O2, and N2 were collected using a temperature-controlled water bath. Figure 5 Figure shows the gas adsorption isotherm curves of the metal-organic framework material at 298 K. It can be seen from the figure that the maximum adsorption capacities of the material for SO2, CO2, O2, and N2 at 298 K are 12.2, 1.07, 0.07, and 0.08 mmol g -1 .

[0057] The breakthrough experiment was carried out using a typical dynamic gas breakthrough device under ambient conditions. In a typical experiment, 50 mg of the MOF powder sample was loaded into a quartz glass column (80 mm in length and 4 mm in inner diameter) and in-situ activated under a He gas flow (15 mL min -1 ) at room temperature for 6 hours. For the trace SO2 capture experiment, a gas mixture simulating flue gas was used: 2500 ppm SO2, 13.5% CO2, 4% O2, and 82.25% N2 (flow rate of 8 mL min -1 ). Figure 6 Figure shows the capture effect diagram of trace SO2 in the simulated flue gas by the metal-organic framework material. The breakthrough experiment confirmed that the material can effectively remove SO2 in the simulated flue gas under dry or 80% relative humidity conditions, and the capture amount is 53.8 mg g -1 .

Claims

1. A layered metal-organic framework material based on a bifunctional ligand Zr, characterized in that, The chemical formula is [Zr6( μ 3-O)4( μ 3-OH)4(OH)4(H2O)4(HPCDA)4]; Among them, Zr6 is an ion cluster; μ 3-O / μ 3-OH are bridging oxygen atoms on the Zr6 cluster; OH / H2O are hydroxide ions / water molecules on the Zr6 cluster; HPCDA is 4,4'-(9-(1 H -pyrazol-4-yl)-9 H -carbazole-3,6-diyl)dibenzoate ion; From the perspective of the framework connection structure, the crystal structure of the layered metal-organic framework material is tetragonal, and the space group is P4 2 / nmc , and the unit cell parameters are: a a = b = 18.5994(±2) Å, c = 32.9902(±4) Å, α α = β = γ = 90 o , V = 11412.6(±3) Å 3 ; The layered metal-organic framework material is composed of a two-dimensional layered structure, specifically an sql topological network structure, and the two-dimensional layered structure is stacked in an interdigitated manner into a three-dimensional overall structure; There are two types of Zr with different connection relationships in the structure of the metal-organic framework material 4+ , where the first Zr 4+ is coordinated with four O atoms from different ligands, two μ3-O and two μ3-OH; the second Zr 4+ is coordinated with two O atoms from different ligands, two μ3-O, two μ3-OH, one terminal OH and one terminal H2O; three first Zr 4+ and three second Zr 4+ form a Zr6 cluster through μ3-O and μ3-OH entities; Each HPCDA is stacked face-to-face with an adjacent HPCDA through π...π interactions between benzene rings, with a center-to-center distance of 3.80 Å; the interconnection of Zr6 clusters and HPCDA ligands paired in a face-to-face manner forms a two-dimensional layer, which is an sql topological network.

2. A bifunctional ligand, characterized in that, The ligand is 4,4'-(9-(1 H -pyrazol-4-yl)-9 H -carbazole-3,6-diyl)dibenzoic acid, abbreviated as H3PCDA. The central core of the ligand is carbazole, which is connected to the first benzoic acid, the second benzoic acid, and pyrazole. The angle between the first dotted line formed by the extension of the first benzoic acid towards the carbazole and the second dotted line formed by the extension of the second benzoic acid towards the carbazole is 90°. The angles between the pyrazole and the first dotted line and the second dotted line are each independently 135°. The specific structural formula of H3PCDA is as follows: 。 3. The preparation method of the bifunctional ligand according to claim 2, characterized in that, It includes the following steps: Step S1: Mix 3,6-dibromo-9 H -carbazole, 4-iodo-1-(tetrahydro-2 H -pyran-2-yl)-1 H -pyrazole, cesium carbonate, lithium chloride, copper(I) iodide and N , N N,N-dimethylformamide. Under the conditions of an inert atmosphere, a pressure of 0.1 - 0.3 MPa, a temperature of 80 - 110 °C, and a time of 24 - 48 h, obtain 3,6-dibromo-9-(1-(tetrahydro-2 H -pyran-2-yl)-1 H -pyrazol-4-yl)-9 H -carbazole; the weight ratio of the 3,6-dibromo-9 H -carbazole, the 4-iodo-1-(tetrahydro-2 H -pyran-2-yl)-1 H -pyrazole, the cesium carbonate, the lithium chloride, and the copper(I) iodide is 20.0:(18.1 - 20.7):(18.7 - 21.6):(5.4 - 7.4):(0.6 - 0.8); the concentration of the 3,6-dibromo-9 H -carbazole in the N , N N,N-dimethylformamide is (60 - 70) g / L; Step S2, mix the 3,6-dibromo-9-(1-(tetrahydro-2 H -pyran-2-yl)-1 H -pyrazol-4-yl)-9 H -carbazole, 4-(methoxycarbonyl)phenyl)boronic acid, potassium carbonate, tetrakis(triphenylphosphine)palladium, and 1,4-dioxane, and under the conditions of an inert atmosphere, a pressure of 0.1 to 0.3 MPa, a temperature of 80 to 100 °C, and a time of 12 to 24 h, obtain dimethyl 4,4'-(9-(1-(tetrahydro-2 H -pyran-2-yl)-1 H -pyrazol-4-yl)-9 H -carbazole-3,6-diyl)dibenzoate; The weight ratio of the 3,6-dibromo-9-(1-(tetrahydro-2 H -pyranyl)-1 H -pyrazol-4-yl)-9 H -carbazole, the 4-(methoxycarbonyl)phenyl)boronic acid, the potassium carbonate and the tetrakis(triphenylphosphine)palladium is 15:(12.5~14.5):(13.1~14.4):(3.7~4.6), and the concentration of the 3,6-dibromo-9-(1-(tetrahydro-2 H -pyranyl)-1 H -pyrazol-4-yl)-9 H -carbazole in 1,4-dioxane is (60~65) g / L; Step S3, reflux dimethyl 4,4'-(9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl)dibenzoate in a hydrochloric acid ethanol solution with a concentration of 2 M for 8 to 12 h, then add deionized water and adjust the pH to 8 to 10 to completely precipitate the precipitate, and then perform suction filtration to obtain methyl 4-(3,6-bis(1H-pyrazol-4-yl)-9H-carbazol-9-yl)benzoate; the concentration of dimethyl 4,4'-(9-(1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)-9H-carbazole-3,6-diyl)dibenzoate in the hydrochloric acid ethanol solution is (30 to 40) g / L; the volume ratio of the hydrochloric acid ethanol solution to the deionized water is 1:1 to 1:3; H -pyran-2-yl)-1 H -pyrazol-4-yl)-9 H -carbazole-3,6-diyl)dibenzoate in a hydrochloric acid ethanol solution with a concentration of 2 M for 8 to 12 h, then add deionized water and adjust the pH to 8 to 10 to completely precipitate the precipitate, and then perform suction filtration to obtain methyl 4-(3,6-bis(1 H -pyrazol-4-yl)-9 H -carbazol-9-yl)benzoate; the 4,4'-(9-(1-(tetrahydro-2 H -pyran-2-yl)-1 H -pyrazol-4-yl)-9 H -carbazole-3,6-diyl)dibenzoate in the hydrochloric acid ethanol solution is (30 to 40) g / L; the volume ratio of the hydrochloric acid ethanol solution to the deionized water is 1:1 to 1:3; Step S4, reflux methyl 4-(3,6-bis(1 H -pyrazol-4-yl)-9 H -carbazol-9-yl)benzoate in potassium hydroxide, tetrahydrofuran, methanol, and deionized water for 8 - 12 h, then adjust the pH to 6 - 8 to completely precipitate the precipitate, and then perform suction filtration to obtain the ligand; The weight ratio of methyl 4-(3,6-bis(1 H -pyrazol-4-yl)-9 H -carbazol-9-yl)benzoate to the potassium hydroxide is 2.1:(3.0 - 5.0), and the concentration of methyl 4-(3,6-bis(1 H -pyrazol-4-yl)-9 H -carbazol-9-yl)benzoate in the tetrahydrofuran is 23 - 35 g / L. The volume ratio of the tetrahydrofuran, the methanol, and the deionized water is 1:(1 - 1.5):(1 - 1.5).

4. The preparation method of the layered metal-organic framework material according to claim 1, characterized in that, Under the conditions of an inert atmosphere, a pressure of 0.1 - 0.5 MPa, a temperature of 80 - 135 °C, and a time of 12 - 48 h, the ligand, metal salt, and solvent are mixed and reacted to obtain the layered metal-organic framework material, and the metal salt is selected from one or more of zirconium tetrachloride and / or zirconyl chloride octahydrate.

5. The preparation method of the layered metal-organic framework material according to claim 4, characterized in that, The metal salt includes zirconium tetrachloride and / or zirconyl chloride octahydrate; when the metal salt is zirconium tetrachloride and zirconyl chloride octahydrate, the molar ratio of zirconium tetrachloride to zirconyl chloride octahydrate is 1:(1 - 2); The solvent is water and an organic solvent, and the volume ratio of water to the organic solvent is (0.2 - 0.8):(1 - 4); the organic solvent is one or more of DMF, acetic acid, DMSO, and NMP; The molar ratio of the ligand to the metal salt is 1:(2 - 6); The concentration of the metal salt in the solvent is 0.04 - 0.15 mol / L.

6. The application of the layered metal-organic framework material according to claim 1 in gas adsorption, for the adsorption and capture of SO2.

Images