Solid bromine-loaded material as well as preparation method and application thereof

Abstract

The invention discloses a solid bromine-loaded material as well as a preparation method and application thereof, and belongs to an adsorption technology. The porous metal organic framework material Cd-MOF provided by the invention can capture and store bromine at normal temperature, and can be used as a novel bromine carrier. Further, in view of the efficient adsorption capacity and stability of the Cd-MOF to the bromine elementary substance, the Cd-MOF can be used for loading bromine to obtain Br2amp; the Br5-atBr-Cd-MOF is the solid bromine-loaded material, and the solid bromine-loaded material can be used as a bromine source to be applied to bromination reaction of toluene and aniline.

Description

Technical Field

[0001] The invention belongs to the field of adsorption technology, and specifically relates to a solid bromine-carrying material and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Bromine-containing compounds are widely used in industrial and agricultural production, such as brominated flame retardants, pesticides, chemical intermediates, halogenated rubber production, etc. Bromination reaction is one of the most important transformations in organic synthesis, which can be carried out using bromine or other bromine-containing reagents. At present, the largest source of bromine is extracted from underground salt water or seawater. The global seawater has abundant bromine reserves, accounting for about 99% of the total bromine reserves on the earth, so bromine is known as the "marine element". The bromine content in seawater is 65mg·L -1 . The air blowing method is currently the main method for extracting bromine from seawater. In view of the high energy consumption disadvantage of traditional processes, it is of great significance to develop simple and environmentally friendly new methods to separate bromine from seawater. Using porous solid materials to study the adsorption and separation of bromine at room temperature can achieve the strategic requirements of low energy consumption and environmental protection. However, due to the high reactivity and strong oxidizing property of bromine, there are not many reports on porous materials (including porous organic polymers (POPs), porous organic cages (POCs) and metal organic frameworks (MOFs)) used for bromine adsorption research. Summary of the invention

[0004] In order to address the deficiencies of the prior art, the purpose of the present invention is to provide a solid bromine-loaded material, a preparation method and an application thereof. Studies have found that a highly stable porous metal-organic framework material Cd-MOF can capture and store bromine at room temperature. Therefore, bromine-loaded Cd-MOF is used as a bromine source in the bromination reaction of toluene and aniline.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] In a first aspect, the present invention provides an application of Cd-MOF in the preparation of a solid bromine-carrying material, wherein the ligand of the Cd-MOF is 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole, and the metal salt is Cd(ClO 4 ) 2 .

[0007] In a second aspect, the present invention provides a solid bromine-loaded material, comprising Cd-MOF and bromine loaded on the Cd-MOF, wherein the ligand of the Cd-MOF is 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole, and the metal salt is Cd(ClO 4 ) 2 ; The bromine is physically adsorbed Br 2 molecules, through ClO 4 - Br obtained by anion exchange - With Br 2 Br formed by molecular interactions 5 - ions and N-Br bonds formed by reaction with amino groups.

[0008] Preferably, the solid bromine-carrying material is Br 2 &Br 5 - @Br-Cd-MOF.

[0009] In a third aspect, the present invention provides a method for preparing the above-mentioned solid bromine-carrying material, comprising the following steps:

[0010] The activated Cd-MOF is placed in a bromine-containing solution for adsorption, and taken out after adsorption to obtain the product.

[0011] In a fourth aspect, the present invention provides the use of the above-mentioned solid bromine-carrying material as a bromine source, preferably, as a bromine source in a bromination reaction; further preferably, the bromination reaction is selected from the bromination reaction of aromatic hydrocarbons or the bromination reaction of aromatic amines, further preferably, the aromatic hydrocarbon includes toluene, and the aromatic amine includes aniline.

[0012] In a fifth aspect, the present invention provides a method for brominating toluene, comprising the following steps: using the above-mentioned solid bromine-carrying material as a bromine source, adding toluene, and stirring the reaction at room temperature.

[0013] In a sixth aspect, the present invention provides a method for brominating aniline, comprising the following steps: using the above-mentioned solid bromine-carrying material as a bromine source, adding aniline and an organic solvent, and stirring the reaction at room temperature and pressure.

[0014] One or some of the above technical solutions have the following advantages or beneficial effects:

[0015] (1) Highly stable porous metal-organic framework material Cd-MOF (composed of 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole and metal Cd(ClO 4 ) 2If the solid bromine carrier can capture and store bromine at room temperature, it can be used as a new bromine carrier to realize solid bromine loading, which can store and transport bromine more safely and conveniently.

[0016] (2) Cd-MOF can be used as an environmentally friendly, efficient and recyclable new material to capture bromine in seawater or salt water. The Cd-MOF captures bromine through multi-path synergistic mechanisms such as physical adsorption, chemical adsorption and anion exchange. The efficiency and reusability of Cd-MOF in adsorbing bromine from seawater were studied through simulation. The adsorption rate was 65% in 1h and 90% in 1.5h. After debromination, the system can still be reused. After three repeated cycles, the adsorption performance only decreased slightly. In addition, the material adsorbing bromine is stable at 100°C, which also shows that Cd-MOF, as a bromine carrier, not only has a high adsorption capacity for bromine, but also has good stability.

[0017] (3) Since bromine has high volatility, toxicity and strong reactivity, and exists in liquid form at room temperature and pressure with high density, it is also inconvenient to use. Therefore, it is very necessary to develop a solid bromine carrier for bromination reaction. In view of the high adsorption capacity and stability of Cd-MOF for bromine, the present invention utilizes Cd-MOF (Br 2 &Br 5 - @Br-Cd-MOF) was used as a bromine source in the bromination reaction of toluene and aniline, verifying its feasibility as a solid bromine reagent.

[0018] (4) According to the structure of MOFs (coordinate bond connection) and the high reactivity and strong oxidizing property of bromine, there are few MOFs used for bromine adsorption. Most MOFs are unstable in bromine adsorption. At the same time, the molecular weight is large (containing metal atoms), and the adsorption amount is generally low. The advantage of the present invention is that Cd-MOF has a high adsorption capacity for Br. 2 The stability of the bromine adsorption system makes it possible to clearly and in detail elucidate its adsorption mechanism by means of single crystal X-ray diffraction. The strong adsorption force of bromine makes the structure stable after adsorption of bromine and allows for a long storage time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] Figure 1 This is a color change diagram of Cd-MOF before and after bromine adsorption in Example 1 of the present invention;

[0021] Figure 2 Cd-MOF and Br in Example 1 of the present invention 2 &Br5 - UV-visible spectrum of @Br-Cd-MOF;

[0022] Figure 3 is Br in Example 1 of the present invention 2 &Br 5 - ORTEP diagram of @Br-Cd-MOF;

[0023] Figure 4 is Br in Example 1 of the present invention 2 &Br 5 - @Br-Cd-MOF crystal structure analysis diagram; Figure 4 The middle part is Br 2 &Br 5 - @Br-Cd-MOF crystal structure, Figure 4 The left side is the frame exchange Br 5 - The arrangement of ions, Figure 4 The lower side is the arrangement of physically adsorbed bromine in the one-dimensional channel. Figure 4 The right side of is the N-Br bond generated by the chemical reaction;

[0024] Figure 5 In Example 1 of the present invention, in DMSO-d 6 Br 2 &Br 5 - @Br-Cd-MOF and Cd-MOF 1 HNMR diagram; the red line represents Br 2 &Br 5 - @Br-Cd-MOF, blue-green lines represent Cd-MOF;

[0025] Figure 6 is Br in Example 1 of the present invention 2 &Br 5 - @FT-IR images of Br-Cd-MOF and Cd-MOF crystals;

[0026] Figure 7 is Br in Example 1 of the present invention 2 &Br 5 - @Thermogravimetric analysis of Br-Cd-MOF and Cd-MOF crystals;

[0027] Figure 8This is an experiment of capturing bromine from seawater or salt water in Application Example 1 of the present invention; wherein (a) is the color change of the bromine salt solution at different times after addition, and (b) is the change of the maximum absorption wavelength of the ultraviolet-visible absorption spectrum with time;

[0028] Fig. 9 This is a graph showing the change in absorbance of the maximum absorption wavelength over time during three repeated adsorption cycles in Application Example 1 of the present invention;

[0029] Fig.10 is the gas-mass spectrum of the toluene bromination reaction in Application Example 2 of the present invention;

[0030] Fig.11 In Application Example 2 of the present invention, in DMSO-d 6 p-Bromoaniline 1 HNMR spectra;

[0031] Fig.12 In Application Example 2 of the present invention, in DMSO-d 6 2,4-Dibromoaniline 1 HNMR spectra;

[0032] Fig.13 In Application Example 2 of the present invention, in DMSO-d 6 2,4,6-Tribromoaniline 1 HNMR spectrum. DETAILED DESCRIPTION

[0033] The existing technology has the following problems: (1) the air blowing method is currently the main method for extracting bromine from seawater, and its energy consumption is relatively high; (2) liquid bromine is generally stored in a brown bottle, covered with a layer of water, and the bromine water on the bromine is easily decomposed by light (similar to chlorine water). In addition, the dropper bottle containing bromine cannot be a rubber-tipped dropper because bromine can react with rubber. Therefore, liquid bromine is not safe to store and inconvenient to use, and the development of solid bromine carriers is necessary; (3) At present, there are relatively few bromine sources for bromination reactions.

[0034] In view of the shortcomings of the prior art, the present invention has found a highly stable porous metal organic framework material Cd-MOF (composed of 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole and metal Cd (ClO 4 ) 2The Cd-MOF captures bromine through a multi-path synergistic mechanism of physical adsorption, chemical adsorption and anion exchange. The efficiency and reusability of Cd-MOF in adsorbing bromine from seawater were studied by simulation, and the adsorption rate reached 90% in 1.5h. After debromination, the system can be reused, and the adsorption performance decreases slightly after three repeated cycles. Since bromine has high volatility and toxicity as well as strong reactivity, and exists in liquid form at room temperature and pressure and has a high density, it is also inconvenient to use. Therefore, it is very necessary to develop a solid bromine carrier for bromination reaction. In view of the high adsorption capacity and stability of Cd-MOF for bromine, the feasibility of Cd-MOF as a solid bromine reagent was verified by further using bromine-loaded Cd-MOF as a bromine source in the bromination reaction of toluene and aniline.

[0035] The first typical embodiment of the present invention provides the use of Cd-MOF in the preparation of solid bromine-carrying materials, wherein the ligand of the Cd-MOF is 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole, and the metal salt is Cd(ClO 4 ) 2 .

[0036] The Cd-MOF is composed of 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole and Cd(ClO 4 ) 2 Preferably, 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole and Cd(ClO 4 ) 2 The mass ratio of is (5-15): (35-45). The Cd-MOF material is [CdL 2 (ClO 4 ) 2 ]·2CH 2 Cl 2 , L is 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole).

[0037] The preparation method of the Cd-MOF is as follows: 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole is dissolved in dichloromethane, Cd(ClO 4 ) 2 Specifically, 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole (10 mg) was dissolved in 7 mL of dichloromethane, and Cd(ClO 4 ) 2(40 mg) was dissolved in 7 mL methanol, mixed and allowed to stand for 4 days. For details, please refer to the paper (Liu Qikui. Self-assembly chemistry and properties of five-membered heterocyclic bridged organic ligands and fluorescent organic ligands [D]. Shandong Normal University.).

[0038] A second typical embodiment provides a solid bromine-loaded material, the solid bromine-loaded material comprising Cd-MOF and bromine loaded on the Cd-MOF, wherein the ligand of the Cd-MOF is 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole, and the metal salt is Cd(ClO 4 ) 2 ; The bromine is physically adsorbed Br 2 molecules, through ClO 4 - Br obtained by anion exchange - With Br 2 Br formed by molecular interactions 5 - ions and N-Br bonds formed by reaction with amino groups.

[0039] Preferably, the solid bromine-carrying material is Br 2 &Br 5 - @Br-Cd-MOF.

[0040] In some examples of this embodiment, the mass ratio of Cd-MOF to bromine is (20-40):(3-8), preferably (30-40):(7-8).

[0041] In some embodiments of this embodiment, the solid bromine-carrying material crystallizes in the tetragonal system and belongs to P4 3 212 chiral space point group, unit cell volume is

[0042] Preferably, the physically adsorbed Br 2 The Br-Br bond length of the molecule is Br 5 - The Br-Br bond length in the ion is The N-Br bond length is

[0043] Preferably, the molecular formula of the solid bromine-carrying material is

[0044] C 48 H 35.6425 CdCl 12 O 4 Br 4.8575 , where the weight percentage of Br element is 28%.

[0045] A third typical embodiment of the present invention provides a method for preparing the above-mentioned solid bromine-carrying material, comprising the following steps:

[0046] The activated Cd-MOF is placed in a bromine-containing solution for adsorption, and taken out after adsorption to obtain the product.

[0047] In some examples of this embodiment, the bromine-containing solution includes liquid bromine, a cyclohexane solution of bromine, seawater or a brine solution containing bromine.

[0048] Preferably, when placed in liquid bromine, the adsorption time is 30min-2h.

[0049] Preferably, when placed in a bromine-containing cyclohexane solution, the adsorption time is 12-72 hours, preferably 24-48 hours.

[0050] Preferably, when placed in bromine-containing seawater or salt water solution, the adsorption time is 1.5-3 hours, preferably 1.5-2 hours.

[0051] Preferably, in the bromine-containing cyclohexane solution, the ratio of bromine to cyclohexane is (1-5 mg):(0.1-2 mL), preferably (2-4 mg):(0.5-1.5 mL).

[0052] Preferably, the mass concentration of the saline solution is 1-5%.

[0053] Preferably, ventilation and standing are required after adsorption is completed.

[0054] In some examples of this embodiment, the Cd-MOF material is [CdL 2 (ClO 4 ) 2 ]·2CH 2 Cl 2 , L is 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole), the activation is to make the Cd-MOF material lose the guest dichloromethane molecule at 140-160° C. for 2-5 h to obtain [CdL 2 (ClO 4 ) 2 ]·H 2 O is the activated Cd-MOF. The reason for activation is to remove the solvent molecules in the framework. The activation temperature is preferably 150°C.

[0055] In some examples of this embodiment, in the bromine-containing cyclohexane solution, the ratio of bromine to cyclohexane is (1-5 mg):(0.1-2 mL), preferably (2-4 mg):(0.5-1.5 mL).

[0056] In some examples of this embodiment, the mass ratio of Cd-MOF to bromine is (10-30):(1-5), preferably (25-25):(2-4).

[0057] In some examples of this embodiment, when placed in a bromine-containing cyclohexane solution, the adsorption time is 12-72 hours, preferably 24-48 hours.

[0058] In some examples of this embodiment, when directly placed in liquid bromine, 0.05 mL of liquid bromine is volatilized by steam, and the adsorption time is 30 min-2 h.

[0059] A fourth embodiment of the present invention provides the use of a solid bromine-carrying material as a bromine source, preferably, as a bromine source in a bromination reaction; further preferably, the bromination reaction is selected from the bromination reaction of aromatic hydrocarbons or the bromination reaction of aromatic amines; preferably, the aromatic hydrocarbon includes toluene, and the aromatic amine includes aniline.

[0060] The fifth embodiment of the present invention provides a method for brominating toluene, comprising the following steps: using the above-mentioned solid bromine-carrying material as a bromine source, adding toluene, and stirring the reaction at room temperature.

[0061] In some examples of this embodiment, the ratio of solid bromine-supporting material to toluene is (30-70 mg):(1-5 mL), preferably (40-60 mg):(1-3 mL).

[0062] In some examples of this embodiment, the stirring reaction time is 1-6 hours, preferably 3-5 hours.

[0063] A sixth embodiment of the present invention provides a reaction method of aniline, comprising the following steps: using the above-mentioned solid bromine-carrying material as a bromine source, adding aniline and an organic solvent, and stirring the reaction at room temperature and pressure.

[0064] In some examples of this embodiment, the organic solvent is an alcohol solvent, and the alcohol includes methanol.

[0065] In some examples of this embodiment, the ratio of solid bromine-carrying material, aniline and organic solvent is (200-400 mg):(30-70 mg):(1-10 mL), preferably (250-350 mg):(40-60 mg):(4-7 mL).

[0066] In some examples of this embodiment, the stirring reaction time is 2-8 hours, preferably 3-5 hours.

[0067] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0068] Example 1

[0069] Bromine vapor absorption experiments were performed as follows: activated (403K, 3h) colorless Cd-MOF (20mg) crystals were placed in a 1cm diameter test tube in a 25mL pressure tube containing a cyclohexane solution (1mL) of dissolved bromine (3mg) (Caution: Bromine is toxic and irritating; appropriate precautions should be taken). After bromine vapor adsorption (48h), the orange crystals ( Figure 1 ) and placed in a fume hood at room temperature for 2 hours to evaporate and remove any bromine adhering to the surface, and finally obtain orange Br 2 &Br 5 - @Br-Cd-MOF.

[0070] like Figure 2 As shown, UV-visible spectroscopy characterization shows that compared with Cd-MOF, Br after adsorption of bromine 2 &Br 5 - @Br-Cd-MOF has obvious visible light absorption in the range of 400-650nm, with maximum absorption at 445nm, which is consistent with the orange color of the crystals.

[0071] Depend on Figure 3 The crystal structure analysis shows that Br 2 &Br 5 - @Br-Cd-MOF crystallizes in the tetragonal system and belongs to P4 3 2 1 2 chiral space point group, the same as Cd-MOF. An asymmetric unit consists of a Cd(II) metal center, a ligand L molecule, a ClO 4 - anion and an adsorbed Br 2 and a Br 5 - Compared with Cd-MOF, Br 2 &Br 5 - @Br-Cd-MOF unit cell volume from Increase to

[0072] like Figure 4 As shown, Br 2 &Br 5 - @Br-Cd-MOF crystal structure (middle); exchange of Br within the framework 5 -Arrangement of ions (left); Arrangement of physically adsorbed bromine in a one-dimensional channel (bottom); N-Br bond generated by chemical reaction (right). Bromine is captured into the framework of Cd-MOF through multiple pathways, including physically adsorbed Br 2 , anion exchange Br 5 - and chemical reaction to form N-Br bonds. 2 and Br 5 - The Br-Br bond lengths are and Both are slightly larger than the Br-Br bond length of bromine at room temperature and pressure. The N-Br bond length is The bond length is the same as that of N-Br in N-bromosuccinimide. 2 The Br…Br distance between them is This Br…Br interaction holds the two Br 2 The molecules are in a one-dimensional channel. One of the ClO 4 - The anion is Br - Exchange, with a stronger The interaction fixes the other two Br 2 Molecules, based on Br 5 - ions. - The chemically generated N-Br bond holds three Br 2 The molecules are in the wall gaps and pores of Cd-MOF. The three adsorption modes of physical adsorption, anion exchange and chemical reaction work synergistically, resulting in Cd-MOF having efficient bromine adsorption and storage performance. 48 H 35.6425 CdCl 12 O 4 Br 4.8575 The weight percentage of Br element in the formula can reach 28%. This material with three adsorption pathways at the same time is of great significance for extracting bromine from seawater.

[0073] In addition to single crystal structure analysis, Br 2 &Br 5 - The crystals of @Br-Cd-MOF were dissolved in deuterated DMSO solvent and the following spectrum was obtained by NMR hydrogen spectrum test, such as Figure 5 As shown, in DMSO-d 6 Br 2 &Br 5 -@Br-Cd-MOF (red line) and Cd-MOF (blue-green line) 1 HNMR (400 MHz, 25 °C). Compared with Cd-MOF, Br 2 &Br 5 - The integral of amino protons in @Br-Cd-MOF is significantly reduced, indicating that the amino groups on the organic ligands are brominated; the proton displacements on the disubstituted benzene ring and pyridine ring move significantly to the downfield, indicating that a large amount of Br in the solution 2 The presence of makes the deuterated reagent acidic, thus affecting the chemical shift of the protons on the pyridine ring and the benzene ring.

[0074] like Figure 6 As shown, Fourier transform infrared (FT-IR) spectroscopy analysis showed that Br 2 Specifically, at 3250cm -1 The characteristic absorption peak of NH at 1610 cm-1 has obvious changes, which indicates the influence of bromine adsorption on amino groups. -1 The C=N stretching vibration absorption peak at 1635 cm-1 and 1595 cm-1 was split into two peaks. -1 , reflecting the effect of bromine adsorption on the ligand heterocycle. -1 ClO 4 - The absorption peak intensity decreases, indicating that ClO 4 - Br 5 - Partial exchange.

[0075] like Figure 7 As shown in Figure 2, the absorption of bromine by Cd-MOF at room temperature was further confirmed by thermogravimetric analysis (TGA). The TGA curve shows that the material adsorbing bromine is stable at 100°C. There is a weight loss of about 20% between 120 and 240°C, which corresponds to the Br in the Cd-MOF framework. 2 of loss.

[0076] Application Example 1: Capturing Bromine from Seawater / Brine

[0077] The effective adsorption of bromine vapor by Cd-MOF suggests its potential for capturing bromine from seawater. Therefore, the adsorption of bromine from brine solutions containing bromine by Cd-MOF was tested in an environment that simulates the extraction of bromine from seawater.

[0078] Figure 8 (a) shows the color change of the bromine salt solution after addition. Figure 8 (b) shows the change of the maximum absorption wavelength (393nm) of the UV-visible absorption spectrum over time. Figure 8 (a) and Figure 8 As can be seen in (b), a Cd-MOF sample (40 mg) was added to a saline solution (3.5% saline, 5 mL) containing bromine (7.8 mg). At ambient temperature, the orange color of the solution gradually faded, and the solution became colorless after 2 h. About 65% of the bromine was removed within an hour. About 90% of the bromine was removed after one and a half hours. The bromine adsorption rate is much faster than that of existing porous materials.

[0079] After bromine is captured, the weakly bound Br 2 From Br 2 &Br 5 - @Br-Cd-MOF. After removing bromine, the Cd-MOF system can be reused. To verify its reusability, three cycle experiments were conducted. Fig. 9 is the change of absorbance at the maximum absorption wavelength (393 nm) over time during three repeated adsorption cycles. Fig. 9 It can be observed that the adsorption performance slightly decreased after three cycles. The above adsorption cycle experiments show that Cd-MOF has potential application prospects in extracting material bromine from brine and seawater.

[0080] Application Example 2: Bromination reaction as a bromine source

[0081] 1.Br 2 &Br 5 - @Br-Cd-MOF was used as a bromine source for bromination reaction test:

[0082] Br 2 &Br 5 - @Br-Cd-MOF (50 mg) was added to toluene (2 mL) and the mixture was stirred at room temperature for 4 hours.

[0083]

[0084] After the reaction, a gas quality test was performed, which showed that benzyl bromide product was generated ( Fig.10 ), indicating its feasibility as a bromine source for bromination reaction. Among them, the yield of toluene bromination product is 52%.

[0085] 2. Br 2 &Br 5 - @Br-Cd-MOF was used as a bromine source to perform the bromination reaction of aniline:

[0086] Br 2 &Br 5 -@Br-Cd-MOF (306 mg) was added to aniline (50 mg) and methanol (5 mL) was used as solvent, and the mixture was stirred at room temperature and pressure for 4 hours.

[0087]

[0088] After the reaction, column chromatography was performed to obtain three brominated products, namely p-bromoaniline (9.1 mg), 2,4-dibromoaniline (9 mg), and 2,4,6-tribromoaniline (18.2 mg). The products were dissolved in deuterated DMSO and the following spectra were obtained by NMR testing. ( Fig.11 : p-bromoaniline, Fig.12 :2,4-dibromoaniline, Fig.13 :2,4,6-tribromoaniline). The yields of the three products of aniline bromination are 14% for monobromoaniline, 12% for dibromoaniline, and 15% for tribromoaniline.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Application of Cd-MOF in the preparation of solid bromine-carrying materials, wherein: The ligand of the Cd-MOF is 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole, and the metal salt is Cd(ClO4)2.

2. A solid bromine-carrying material, characterized in that: The solid bromine-loaded material comprises Cd-MOF and bromine loaded on the Cd-MOF, wherein the ligand of the Cd-MOF is 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole, and the metal salt is Cd(ClO4)2; The bromine is physically adsorbed as Br2 molecules, through ClO4 - Br obtained by anion exchange - Br5 formed by interaction with Br2 molecules - ions and N-Br bonds formed by reaction with amino groups.

3. The solid bromine-carrying material according to claim 2, characterized in that: The mass ratio of Cd-MOF to bromine is (20-40):(3-8), preferably (30-40):(7-8).

4. The solid bromine-carrying material according to claim 2, characterized in that: The solid bromine-carrying material crystallizes in the tetragonal system, belongs to the P43212 chiral space point group, and has a unit cell volume of Preferably, the Br-Br bond length of the physically adsorbed Br2 molecule is Br5 - The Br-Br bond length in the ion is The N-Br bond length is Preferably, the molecular formula of the solid bromine-carrying material is C 48 H 35.6425 CdCl 12 O4Br 4.8575 , where the weight percentage of Br element is 28%.

5. A method for preparing the solid bromine-carrying material according to any one of claims 2 to 4, characterized in that: The following steps are involved: The activated Cd-MOF is placed in a bromine-containing solution for adsorption, and taken out after adsorption to obtain the product.

6. The preparation method according to claim 5, characterized in that: Bromine-containing solutions include liquid bromine, bromine cyclohexane solution, bromine-containing seawater or salt water solution; Preferably, when placed in liquid bromine, the adsorption time is 30min-2h; Preferably, when placed in a bromine-containing cyclohexane solution, the adsorption time is 12-72 hours, preferably 24-48 hours; Preferably, when placed in bromine-containing seawater or brine solution, the adsorption time is 1.5-3h, preferably 1.5-2h; Preferably, in the bromine-containing cyclohexane solution, the ratio of bromine to cyclohexane is (1-5 mg):(0.1-2 mL), preferably (2-4 mg):(0.5-1.5 mL); Preferably, the mass concentration of the saline solution is 1-5%; Preferably, ventilation and standing are required after adsorption is completed.

7. The preparation method according to claim 5, characterized in that: The Cd-MOF material is [CdL2(ClO4)2]·2CH2Cl2, L is 4-amino-3,5-di(4-pyridine-3-phenyl)-1,2,4-triazole), and the activation is to make the Cd-MOF material lose the guest dichloromethane molecule at 140-160°C for 2-5h to obtain [CdL2(ClO4)2]·H2O with nanopores, which is the activated Cd-MOF.

8. Use of the solid bromine-carrying material according to any one of claims 2 to 4 as a bromine source, preferably, use as a bromine source in a bromination reaction; further preferably, the bromination reaction is selected from the bromination reaction of aromatic hydrocarbons or the bromination reaction of aromatic amines; preferably, the aromatic hydrocarbon includes toluene, and the aromatic amine includes aniline.

9. A method for brominating toluene, characterized in that: The method comprises the following steps: using the solid bromine-carrying material according to any one of claims 2 to 4 as a bromine source, adding toluene, and stirring the reaction at room temperature; Preferably, the ratio of solid bromine-carrying material to toluene is (30-70 mg):(1-5 mL), preferably (40-60 mg):(1-3 mL); Preferably, the stirring reaction time is 1-6 h, preferably 3-5 h.

10. A method for brominating aniline, characterized in that: The method comprises the following steps: using the solid bromine-carrying material according to any one of claims 2 to 4 as a bromine source, adding aniline and an organic solvent, and reacting by stirring at room temperature and pressure; Preferably, the organic solvent is an alcohol solvent; Preferably, the ratio of the solid bromine-carrying material, aniline and organic solvent is (200-400 mg):(30-70 mg):(1-10 mL), preferably (250-350 mg):(40-60 mg):(4-7 mL); Preferably, the stirring reaction time is 2-8 h, preferably 3-5 h.

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