[N... Cl... N] < + > two-dimensional supramolecular halogen bond organic framework XOF (Cl) as well as preparation method and application of [N... Cl... N] < + > two-dimensional supramolecular halogen bond organic framework XOF (Cl)

Abstract

The invention discloses a [N... Cl... N] < + > two-dimensional supramolecular halogen bond organic framework XOF (Cl) as well as a preparation method and application thereof, and belongs to the technical field of organic framework materials. The method comprises the following steps: adding hydrochloric acid into potassium permanganate at a certain temperature to generate chlorine in situ, controlling the concentration of the chlorine to be 25 vol.%-60 vol.% of an inert gas environment, then introducing the chlorine into a ligand solution, and adding an AgBF4 reagent at a certain temperature to react; after the reaction is completed, recovering and purifying the product to obtain the [N... Cl... N] < + > two-dimensional supramolecular halogen bond organic framework XOF (Cl); the ligand is a ligand containing polydentate substituted pyridine / imidazole. The method is simple in step and convenient to operate, stable Cl < + > exists in a rigid framework in the product, and the product is high in crystallinity and good in chemical stability and thermal stability. When used as a carrier of an active Pd (0) catalyst, the catalyst shows excellent catalytic activity in a Pd catalytic coupling reaction, and high yield can be realized even under an air condition. And the catalyst can be simply filtered and recycled, and can still keep stable catalytic performance after being recycled for multiple times.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic framework materials, and particularly relates to a [N···Cl···N] + A two-dimensional supramolecular halogen bond organic framework XOF(Cl) and a preparation method and application thereof. BACKGROUND

[0002] In recent years, the development of organic frameworks constructed through covalent and noncovalent interactions has given rise to a new class of multifunctional porous materials. These frameworks have permanent porosity, structural tunability, and functional adaptability, and thus are extremely attractive in applications such as gas storage, catalysis, solar energy conversion, organic electronics, and energy storage. Covalent bonds provide structural stability, while noncovalent interactions become an important tool for achieving flexibility and self-correction during the synthesis process. These reversible interactions, such as hydrogen bonds, halogen bonds, and π-π interactions, have the advantage of promoting highly ordered frameworks through dynamic rearrangement and error correction during assembly. The inherent directionality of noncovalent interactions enables precise control of molecular arrangement, which is crucial for the manufacture of highly crystalline materials. Covalent bonds can be too rigid, limiting flexibility, while noncovalent interactions are different, and they can strike a balance between order and adaptability. However, frameworks relying solely on noncovalent interactions may face challenges in maintaining stability under external stimuli, and achieving an appropriate balance between structural integrity and functional adaptability remains key. Therefore, it is still crucial to explore new connection modes to construct stable or highly adaptive structures.

[0003] Noncovalent interactions (NCI) play a crucial role in stabilizing and directing the assembly of functional materials, chemical systems, and biological structures. Although NCI is relatively weak compared to covalent bonds, it has attracted widespread attention due to its wide application in material science and supramolecular chemistry. Among various NCIs, halogen bond (XB) is defined as an attractive interaction between a halogen atom (X) and a Lewis base (Y), and has become a powerful tool for rationally designing supramolecular structures. This interaction is mainly driven by the σ-hole effect, in which the electron-deficient region on the halogen atom aligns with a nucleophilic species, resulting in a highly directional and predictable interaction. The development of XB-based systems has kept pace with the development of hydrogen bonds, highlighting the potential of XB in the fields of crystal engineering, catalysis, and molecular recognition. In recent decades, halogen bonds have been classified into three categories: neutral halogen bond (R-X···Y), fluorinated halogen bond (RF-X···Y), and charged three-center four-electron halogen bond ([D···X···D] +). These three classes of halogen bonds have different properties and can be used for tailored applications. For example, the neutral C-I···N system has been used for the development of phosphorescent materials, while the charged [N···X···N] + Halogen bonds have also contributed to the creation of supramolecular capsules, helical structures, and porous structures. The third class of halogen bonds has received particular attention because of the unique reactivity and geometric properties of halogens in hypercoordinated systems, where a positively charged halogen atom is stabilized between two Lewis bases, forming a linear three-center bond. Recent studies have utilized [N···I···N] + and [N···Br···N] + Halogen bonds have constructed two-dimensional halogen-bonded organic frameworks (XOFs) that have shown promise in areas such as fatty acid vapor adsorption, iodine substitution reactions, and oxidation processes.

[0004] In Chinese invention patent CN116239779A, the inventors' team discloses a two-dimensional halogen-bonded organic framework material for iodinating reagents, its preparation method and application. The organic framework material is a two-dimensional network structure, [N···I + ···N] connected halogen-bonded organic framework material has stable I + exists in a rigid skeleton, has good crystallinity and thermal stability, and the preparation method is simple and easy to operate. The iodinating reagent used in the iodination reaction of aryl boronic acid can make the reaction obtain good yield under catalyst-free and mild conditions. Chinese invention patent CN119454980A provides a drug composition based on two-dimensional halogen-bonded organic framework XOFs and its application in the treatment of bacterial keratitis. The two-dimensional halogen-bonded organic framework XOFs are selected from at least one of XOF(X)-TPPA and XOF(X)-TPPE, and X is halogen selected from I or Br. The drug composition forms a composite drug based on two-dimensional halogen-bonded organic framework XOFs by loading new indocyanine green, has good antibacterial effect and can have good therapeutic effect on bacterial keratitis.

[0005] XOFs based on iodine (I) and bromine (Br) show great promise, but it is of great significance to extend this approach to other halide ions, such as Cl + The potential advantage of Cl lies in its wide natural abundance and low cost, making it more economically attractive for industrial-scale production; in addition, the high electronegativity and smaller atomic size of Cl may endow XOFs with unique reactivity or electronic properties, such as excellent performance in catalysis or specific chemical environments, while Br and I are limited by higher cost and sensitivity, limiting their widespread application. Although [N···Cl···N] +Two-dimensional supramolecular halogen-bonded organic frameworks (XOFs) have significant economic and potential functional advantages over bromine and iodine, but also face unique technical challenges. The halogen bond strength increases with the increasing polarizability of the halogen atom, in the order of F < Cl < Br < I. Due to the low polarizability of Cl, the σ-hole of Cl is small, resulting in [N···Cl···N] + The electrostatic and covalent interactions of the bond are weak, and the stability of the framework is insufficient. Literature shows that Cl-based complexes (such as Py2Cl) need to be prepared in an argon environment at -78 ℃ and characterized at -80 ℃, highlighting their high sensitivity and instability. XOFs of I and Br (such as XOF-TPPE and XOF(Br)-TPy-BF4 / OTf) can form stable frameworks under milder conditions due to their strong halogen bonds. Directly applying the synthesis method (such as simple Ag + ion exchange) of XOF(Br) and XOF(I) to XOF(Cl) is difficult to crystallize due to the weak Cl halogen bond, and it is difficult to efficiently realize [N···Cl···N] + connected XOF(Cl) preparation. In summary, breaking through the bottleneck of the prior art and opening up a new path for the application of chlorine chemistry in supramolecular chemistry and materials science is of great significance. SUMMARY

[0006] In view of the above defects of the prior art, in the first aspect of the present application, a simple and efficient [N···Cl···N] + Two-dimensional supramolecular halogen-bonded organic framework XOF(Cl) preparation method, comprising the following steps: Add hydrochloric acid to potassium permanganate in situ to generate chlorine at a certain temperature, control the chlorine concentration to be 25 vol.%~60 vol.% of the inert gas environment, then pass the ligand solution, and add AgBF4 reagent at a certain temperature to react; after the reaction is complete, recover and purify the product to obtain [N···Cl···N] + Two-dimensional supramolecular halogen-bonded organic framework XOF(Cl); The ligand is a ligand containing a multi-dentate substituted pyridine / imidazole.

[0007] Preferably, the hydrochloric acid is 6~12 N hydrochloric acid; the molar ratio of hydrochloric acid to potassium permanganate is (3~5):1.

[0008] Preferably, the reaction temperature for in-situ generation of chlorine is -10~0 ℃.

[0009] Preferably, the ligand is at least one of the following structures: , , , , , .

[0010] Preferably, the molar ratio of the ligand, chlorine, AgBF4 is 1: (1.5~2): (1.5~2).

[0011] Preferably, the reaction is carried out at room temperature, and the reaction time is 1~4 h.

[0012] Preferably, the [N···Cl···N] + The specific operation of the preparation method of the two-dimensional supramolecular halogen bond organic framework XOF(Cl) is as follows: (1) Hydrochloric acid is added dropwise to potassium permanganate at a certain temperature to generate chlorine in situ, and the chlorine concentration is controlled to be 25 vol.%~60 vol.% of the inert gas environment; (2) The ligand is dissolved in an organic solvent I to obtain a ligand solution; (3) Chlorine is introduced into the obtained ligand solution, and stirring is carried out at a certain temperature to form a mixed solution; (4) AgBF4 is dissolved in an organic solvent II, and then added dropwise into the mixed solution, and stirring is carried out until the reaction is complete, and then the precipitate is separated, washed and dried to obtain a crude product; (5) The crude product is added to an organic solvent III, heated and treated for a certain time, and then the precipitate is separated by cooling, washed and dried to obtain [N···Cl···N] + The two-dimensional supramolecular halogen bond organic framework XOF(Cl).

[0013] Further preferably, the organic solvent I is a solvent formed by at least one of chloroform and methanol; the organic solvent II is methanol; and the organic solvent III is methanol or N-methyl pyrrolidone.

[0014] Further preferably, the stirring temperature is -10~0 ℃, and the stirring time is 0.5~1 h.

[0015] Further preferably, the temperature of the heat preservation treatment is 40~200 ℃, and the time is 0.1~2 h.

[0016] In the second aspect of the present application, a Cl + The [N···Cl···N] exists in a rigid skeleton, and has good crystallinity and thermal stability. + The two-dimensional supramolecular halogen bond organic framework XOF(Cl) is made by the preparation method of the first aspect of the present application, and has any one of the following structures: XOF(Cl)-BPy: ; XOF(Cl)-TPy: ; XOF(Cl)-TPPA: ; XOF(Cl)-TPPE: ; XOF(Cl)-TIB: ; XOF(Cl)-TPIB: .

[0017] In a third aspect of the present application, there is provided a [N···Cl···N] of the second aspect of the present application + application of the two-dimensional supramolecular halogen bond organic framework XOF(Cl), specifically for use as an active Pd(0) catalyst carrier.

[0018] Based on the above technical solutions, the design concept and principle of the present application are as follows: The invention motivation of the present solution stems from overcoming the limitation of weak Cl halogen bond. By developing a novel and economical synthesis strategy, using optimized Cl2 concentration control and multi-step coordination process, stable [N···Cl···N] + connected XOF(Cl) is achieved, thereby breaking through the bottleneck of the prior art and opening up a new path for the application of chlorine chemistry in supramolecular chemistry and materials science. In the preparation process of the present method, first, Cl + is coordinated with the ligand, and then BF4 - is introduced through anion exchange, and the Cl2 gas concentration is accurately controlled to obtain a product with high crystallinity, otherwise a stable structure cannot be obtained.

[0019] When the stable synthesis of XOF(Cl) is achieved, it can be used as a carrier for active Pd(0) catalyst in stable organic frameworks. The XOF(Cl)-Pd 0 prepared therefrom exhibits excellent catalytic activity in Pd-catalyzed coupling reactions such as Suzuki, Heck, and Sonogashira, and can achieve high yield even under air conditions. Importantly, when synthesizing industrially important related liquid crystal molecules and drug molecules, there is no detectable residual palladium, and the catalyst can be recovered by simple filtration and still maintain stable catalytic performance after multiple cycles. 0

[0020] Compared with the prior art, the present application has the following advantages and beneficial effects: The present application provides a [N···Cl···N] + The preparation method of the two-dimensional supramolecular halogen bond organic framework XOF(Cl) has simple steps and is easy to operate, and solves the problems of traditional [N···Cl···N] + ​The preparation process of the complex (Py2Cl) is complex and harsh, and the stability is low; BF4 is introduced by anion exchange - , and the Cl halogen bond sensitivity is overcome by accurately controlling the Cl2 gas concentration in multiple steps, so that [N···Cl···N] is efficiently prepared + The connected XOF(Cl) is connected.

[0021] The present application provides a [N···Cl···N] + The two-dimensional supramolecular halogen bond organic framework XOF(Cl) is [N···Cl···N] + The connected halogen bond organic framework material has stable Cl + It exists in a rigid skeleton, has high crystallinity, and has good chemical stability and thermal stability.

[0022] The present application provides a [N···Cl···N] + The application of the two-dimensional supramolecular halogen bond organic framework XOF(Cl) as a carrier of active Pd(0) catalyst exhibits excellent catalytic activity in Pd-catalyzed coupling reactions. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The [N···Cl···N] prepared by the present application is connected. + The X-ray photoelectron spectroscopy (XPS) diagram of the two-dimensional supramolecular halogen bond organic framework XOF(Cl) prepared by the present application is connected. Figure 2 The [N···Cl···N] prepared by the present application is connected. + The powder X-ray diffraction (PXRD) diagram of the two-dimensional supramolecular halogen bond organic framework XOF(Cl) prepared by the present application is connected. Figure 3 The [N···Cl···N] prepared by the present application is connected. + The halogen bond organic framework of the two-dimensional supramolecular halogen bond organic framework XOF(Cl) prepared by the present application is connected. Figure 4 The XOF(Cl)-TPy-Pd catalyst prepared by the present application is connected. 0 The conceptual diagram of the catalyst is connected. Figure 5 The yield of the reaction of Examples 3-5 is connected. a The yield under a nitrogen atmosphere is connected, b The yield under an air atmosphere is connected. Figure 6In the present application, (a) is a flow chart of the synthesis of the biphenyl liquid crystal molecule of industrial importance; (b) and (c) are XOF(Cl)-TPy-Pd 0 The residual amount of palladium in the catalyst and the recycling rate. DETAILED DESCRIPTION

[0024] The present application is further illustrated by the following examples without limiting the present application to the examples described. The experimental methods in the following examples, if not otherwise specified, are selected according to the conventional methods and conditions, or according to the instructions of the commercial products.

[0025] Example 1 [N···Cl···N] + The preparation method of the two-dimensional supramolecular halogen bond organic framework XOF(Cl) is as follows: (1) 6 N (generally, the reaction concentration is 6-12 N, and in the present application, 6 N is preferred) hydrochloric acid 0.15 mol (generally, the reaction molar amount is 0.15-0.6 mol, and in the present application, 0.15 mol is preferred) is added dropwise into potassium permanganate 0.05 mol (generally, the reaction molar amount is 0.05-0.2 mol, and in the present application, 0.05 mol is preferred) at -10 ℃ (generally, the reaction temperature is -10-0 ℃, and in the present application, -10 ℃ is preferred) to generate chlorine gas in situ in an inert gas environment (generally, the reaction concentration is 25 vol.%-60 vol.%, and in the present application, 25 vol.% is preferred); (2) The ligand (0.08-0.32 mmol) , , , , , is dissolved in 20 mL (generally, the reaction solvent amount is 20-120 mL, and in the present application, 20 mL is preferred) CHCl3 / MeOH (v / v=4:1) (either methanol and chloroform alone or a mixture of the two in any ratio can be used as the solvent, and in the present application, CHCl3 / MeOH (v / v=4:1) is preferred) mixed solution to obtain a ligand solution; (3) Chlorine gas 0.15 mmol (generally, the reaction molar amount is 0.15-0.45 mol, and in the present application, 0.15 mol is preferred) is introduced into the obtained ligand solution, and stirred at -10 ℃ (generally, the reaction temperature is -10-0 ℃, and in the present application, -10 ℃ is preferred) for 0.5 h (generally, the reaction time is 0.5-1 h, and in the present application, 0.5 h is preferred) to form a mixed solution; (4) 0.15 mmol of AgBF4 (the general reaction molar amount is 0.15-0.45 mol, preferably 0.15 mol in this embodiment) was dissolved in 5 mL (the general reaction solvent amount is 5-30 mL, preferably 5 mL in this embodiment) of methanol, and added dropwise to the mixed solution while stirring, and stirred at room temperature for 1 h; after the reaction was complete, the mixture was filtered, washed, and dried to obtain a light yellow solid; (5) In 2 mL (generally 2-10 mL of reaction solvent, preferably 2 mL in this embodiment) of MeOH / NMP (v / v = 2:1), stir at 130 °C (generally 40-200 °C, preferably 130 °C in this embodiment) for 1 h (generally 0.1-2 h, preferably 1 h in this embodiment), and then slowly cool down; filter the precipitate, wash with dichloromethane, and vacuum dry to obtain halogen bond organic frameworks XOF(Cl)-BPy, XOF(Cl)-TPy, XOF(Cl)-TPPA, XOF(Cl)-TPPE, XOF(Cl)-TIB, and XOF(Cl)-TPIB, respectively.

[0026] The molecular structures of the products are shown below: XOF(Cl)-BPy: ; XOF(Cl)-TPy: ; XOF(Cl)-TPPA: ; XOF(Cl)-TPPE: ; XOF(Cl)-TIB: ; XOF(Cl)-TPIB: .

[0027] Taking the representative product XOF(Cl)-TPy as an example, its X-ray photoelectron spectrum is as follows Figure 1 As shown in the figure, the data were collected on an ESCALAB 250Xi photoelectron spectrometer. As can be seen from the figure: in the spectrum of XOF(Cl)-TPy, the peaks at 202.8 eV and 204.5 eV can be attributed to Cl + Cl 2P 3 / 2 and Cl 2P 1 / 2 orbital, the peaks at 199.8 eV and 198.2 eV can be assigned to Cl - Cl 2P 3 / 2 and Cl 2P 1 / 2 orbitals, these results indicate that Cl + stable existence.

[0028] The powder X-ray diffraction pattern of the XOF(Cl)-TPy prepared in this example is shown in FIG. 1, and the data was collected on a Rigaku SmartLab SE X-ray diffractometer in Japan. As can be seen from the figure, a strong (110) diffraction peak was observed at 2q = 7.09°, while the diffraction peaks at 10.57°, 14.66°, 16.43°, 18.33° and 19.91° were indexed as (210), (201), (121), (4-21) and (5-50) reflections, respectively. This indicates that the prepared XOF(Cl)-TPy has good crystallinity. Figure 2

[0029] As shown in FIG. 2, the XOF(Cl)-TPy was placed in the chemical environment of common solvents (N,N-dimethylformamide, tetrahydrofuran, dichloromethane, acetone, methanol, n-hexane, water) at room temperature for 24 h. The PXRD pattern did not change, indicating that the XOF(Cl)-TPy has a stable crystal structure and high chemical stability when incubated with various solvents under the above conditions. Figure 3 The thermal stability curve of the two-dimensional halogen-bonded organic framework material prepared in this example is shown in FIG. 3; the data was collected on a TGA / DSC1 simultaneous thermal analyzer from Mettler Toledo, Switzerland. As can be seen from the figure, the halogen-bonded organic framework prepared in this example starts to lose weight from at least 300 °C, indicating its good thermal stability.

[0030] Figure 3 Example 2 In this example, Pd 0 was loaded onto the XOF(Cl) prepared in Example 1 to prepare a recyclable XOF(Cl)-TPy-Pd 0 catalyst, the flow chart is shown in FIG. 4, and the steps are as follows:

[0031] In this example, Pd 0 was loaded onto the XOF(Cl) prepared in Example 1 to prepare a recyclable XOF(Cl)-TPy-Pd 0 catalyst, the flow chart is shown in FIG. 4, and the steps are as follows: Figure 4 Na2PdCl4was dissolved in water under stirring, and then added dropwise to the aqueous solution of XOF(Cl); after stirring at room temperature for 12 h, a light yellow solid XOF(Cl)-TPy-Pd Ⅱ was formed. Then, hydrazine hydrate was added dropwise to the reaction system, and the reaction was continued for 1 h to form a brown-black powder; after washing with EtOH and vacuum drying overnight, XOF(Cl)-TPy-Pd 0 was obtained.

[0032] Example 3 Catalytic reaction evaluation: using Suzuki coupling reaction as a model reaction, iodobenzene and phenylboronic acid as the reaction substrates, XOF(Cl)-Pd0catalyst was used in Toluene / EtOH / H2O (2:1:1) at 110 ℃ for 8 h under nitrogen or air atmosphere. According to the experimental results, the product biphenyl was provided with a yield of 90%.

[0033] Scope study: the scope of different aryl halides and aryl substituted boronic acids was studied under nitrogen or air atmosphere. The results showed that most of the aryl substituted boronic acids could be efficiently converted into coupling products with a yield of up to 96%.

[0034] Suzuki coupling reaction conditions: iodobenzene (0.10 mmol), phenylboronic acid (0.15 mmol), potassium carbonate (0.30 mmol), XOF(Cl)-TPy-Pd 0 (0.5 mol.%), and Toluene / EtOH / H2O (2:1:1, 3 mL) were mixed and added to a round-bottom flask; the reaction was heated at 110 ℃ for 8 h under nitrogen or air atmosphere; after the reaction was completed (monitored by TLC), the catalyst was separated by filtration, and the reaction mixture was poured into water and extracted with diethyl ether; the extract was dried, and the solvent was removed under reduced pressure, and the product was purified by column chromatography, see Figure 5 .

[0035] Recyclability and palladium residue evaluation: taking the synthesis of an industrially important biphenyl liquid crystal molecule as an example, XOF(Cl)-TPy-Pd 0 can be removed and recycled from the reaction medium by simple filtration. After several recycling experiments, XOF(Cl)-TPy-Pd 0 still maintains high stability and catalytic activity. As Figure 6 shown in the figure, the catalytic efficiency of the supported catalyst prepared in this embodiment after being recycled for multiple times, it can be seen from the figure that the XOF(Cl)-TPy-Pd 0 catalyst of the present application still has a high recovery rate after being recycled for multiple times, and has no detectable palladium residue.

[0036] Example 4 Heck coupling reaction conditions: iodobenzene (0.10 mmol), olefin (0.12 mmol), triethylamine (TEA, 0.20 mmol), tetrabutylammonium bromide (TBAB, 0.20 mmol), and XOF(Cl)-TPy-Pd 0(0.5 mol%) was added to dioxane (3 mL); the reaction mixture was stirred at reflux under air atmosphere at 100 °C. After completion of the reaction (TLC monitoring), the mixture was filtered and the solid was washed with dichloromethane; the filtrate was evaporated under reduced pressure, the crude product was dissolved in ethyl acetate and filtered to remove excess TBAB; the solvent was evaporated under reduced pressure and the product was purified by column chromatography, see Figure 5 .

[0037] Example 5 Sonogashira coupling reaction conditions: iodoarene (0.10 mmol), phenylacetylene (0.15 mmol), urea (0.20 mmol), K2CO3(0.30 mmol) and XOF(Cl)-TPy-Pd 0 (0.5 mol%) was added to EtOH (3 mL). The reaction mixture was stirred at room temperature under air atmosphere; after completion of the reaction (TLC monitoring), the mixture was filtered and the solid was washed with dichloromethane; the filtrate was evaporated under reduced pressure and the product was purified by column chromatography, see Figure 5 .

[0038] In summary, the [N···Cl···N] halogen bond of the present application + The two-dimensional supramolecular halogen bond organic framework XOF(Cl) has stable Cl + exists in a rigid skeleton, and has good crystallinity and thermal stability. The preparation method has simple steps and is easy to operate. The XOF(Cl) can be used as a carrier for stable Pd(0) catalyst in an organic framework. The XOF(Cl)-Pd 0 exhibits excellent catalytic activity in Pd-catalyzed coupling reactions such as Suzuki, Heck and Sonogashira, and can achieve high yield even under air conditions. The XOF(Cl)-Pd 0 has no detectable residual palladium when synthesizing industrially important related liquid crystal molecules and drug molecules, and the catalyst can be recovered by simple filtration and still maintains stable catalytic performance after multiple cycles.

[0039] The above describes in detail the preferred embodiments of the present application. It should be understood that those skilled in the art can make many modifications and changes without creative labor according to the concept of the present application. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiment on the basis of the prior art according to the concept of the present application shall be within the protection scope defined by the claims.

Claims

1. A [N···Cl···N] + The preparation method of the two-dimensional supramolecular halogen bond organic framework XOF(Cl) is characterized in that: The steps include: At a certain temperature, hydrochloric acid is added to potassium permanganate to generate chlorine in situ. The chlorine concentration is controlled to be 25 vol.% to 60 vol.% of the inert gas environment. The chlorine is then introduced into the ligand solution. AgBF4 reagent is added at a certain temperature to react. After the reaction is complete, the product is recovered and purified to obtain [N···Cl···N] + Two-dimensional supramolecular halogen-bonded organic framework XOF(Cl); the ligand is a ligand containing multidentate substituted pyridine / imidazole.

2. [N···Cl···N] according to claim 1 + A method for preparing a two-dimensional supramolecular halogen-bonded organic framework XOF(Cl) is characterized by: The hydrochloric acid is 6-12 N hydrochloric acid; the molar ratio of hydrochloric acid to potassium permanganate is (3-5):

1.

3. [N···Cl···N] according to claim 1 + A method for preparing a two-dimensional supramolecular halogen-bonded organic framework XOF(Cl) is characterized by: The reaction temperature for the in-situ generation of chlorine is -10~0°C.

4. [N···Cl···N] according to claim 1 + A method for preparing a two-dimensional supramolecular halogen-bonded organic framework XOF(Cl) is characterized by: The ligand is at least one of the following structures: 、 、 、 、 、 。 5. [N···Cl···N] according to claim 1 + A method for preparing a two-dimensional supramolecular halogen-bonded organic framework XOF(Cl) is characterized by: The molar ratio of the ligand, chlorine gas and AgBF4 is 1: (1.5~2): (1.5~2).

6. [N···Cl···N] according to claim 1 + A method for preparing a two-dimensional supramolecular halogen-bonded organic framework XOF(Cl) is characterized by: The reaction is carried out at room temperature and the reaction time is 1 to 4 hours.

7. [N···Cl···N] according to claim 1 + The preparation method of the two-dimensional supramolecular halogen bond organic framework XOF(Cl) is characterized in that: Said [N···Cl···N] + The specific steps of the preparation method of the two-dimensional supramolecular halogen-bonded organic framework XOF(Cl) are as follows: (1) Hydrochloric acid is added dropwise to potassium permanganate at a certain temperature to generate chlorine in situ. The chlorine concentration is controlled to be 25 vol.%~60 vol.% of the inert gas environment; (2) dissolving the ligand in an organic solvent I to obtain a ligand solution; (3) Passing chlorine gas into the obtained ligand solution and stirring at a certain temperature to form a mixed solution; (4) dissolving AgBF4 in organic solvent II, then adding it dropwise to the mixed solution and stirring until the reaction is complete. The precipitate is then separated, washed, and dried to obtain a crude product. (5) The crude product is added to an organic solvent III, heated and kept warm for a certain period of time, then cooled and separated, and the precipitate is washed and dried to obtain [N···Cl···N] + Two-dimensional supramolecular halogen-bonded organic framework XOF(Cl).

8. [N···Cl···N] according to claim 7 + A method for preparing a two-dimensional supramolecular halogen-bonded organic framework XOF(Cl) is characterized by: The organic solvent I is a solvent formed by at least one of chloroform and methanol; the organic solvent II is methanol; the organic solvent III is methanol or N-methylpyrrolidone; the stirring temperature is -10~0°C, and the stirring time is 0.5 h; the temperature of the insulation treatment is 40~200°C, and the time is 0.1~2 h.

9. A [N···Cl···N] + Two-dimensional supramolecular halogen-bonded organic framework XOF(Cl), characterized by: It is prepared by the preparation method according to any one of claims 1 to 8, and has a structure as shown below: XOF(Cl)-BPy: ; XOF(Cl)-TPy: ; XOF(Cl)-TPPA: ; XOF(Cl)-TPPE: ; XOF(Cl)-TIB: 4 XOF(Cl)-TPIB: 。 10. [N···Cl···N] according to claim 9 + Application of the two-dimensional supramolecular halogen-bonded organic framework XOF(Cl), characterized by: As an active Pd(0) catalyst support.

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