An organic cage framework synthesized based on the Yamamoto coupling reaction, its preparation method, and its application in oil-water separation.

Abstract

This invention discloses a type of organic cage framework synthesized based on Yamamoto coupling reaction, its preparation method, and its application in oil-water separation, belonging to the field of porous organic material polymer technology. This invention is the first to propose extending porous organic cages from 0D to 3D polymer materials of organic cage framework using Yamamoto coupling reaction. Based on tetraaldehyde resorcinol calix[4] aromatics, bromine-functionalized porous organic cages with high specific surface area are extended into porous polymers of organic cage framework with high specific surface area using Yamamoto coupling reaction, and a series of hydrophobic OCFs materials are constructed, which have stable and excellent separation effect on oil-water mixtures. Through Yamamoto coupling reaction, the parent material, namely porous organic cages that can be dissolved in most organic solvents, is polymerized into organic cage framework materials that are insoluble in common organic solvents, solving the problem of solubility of porous organic cages while retaining their porous properties, which is beneficial for efficient separation of oil-water mixtures.

Description

Technical Field

[0001] This invention belongs to the field of porous organic polymer technology, specifically relating to a class of organic cage frameworks (OCFs) synthesized based on Yamamoto coupling reaction, their preparation method, and their application in oil-water separation. Background Technology

[0002] Large quantities of oil-water mixtures are generated as byproducts in industrial production processes, and a significant amount of wastewater produced globally flows into oceans and lakes without adequate treatment, severely harming ecosystems. This not only causes serious environmental problems but also endangers public health and affects people's vital interests. Therefore, developing efficient oil-water separation materials has become a critical issue that urgently needs to be addressed. To date, several hydrophobic materials, such as polymers, metal-organic frameworks, zeolites, and nanoparticles, have been coated onto matrix materials such as mesh supports, filter paper, and sponges for oil-water separation. However, these materials suffer from problems such as easy heavy metal pollution, low oil-water separation efficiency, and easy detachment of nanoparticles. Therefore, developing a novel oil-water separation material with high efficiency and stability remains an urgent problem to be solved.

[0003] Porous organic cages (POCs) are a new type of porous crystalline material mainly composed of light elements (C, H, O, and N, etc.). Due to their structural diversity, high crystallinity, and regular pores, they have broad potential applications in energy storage, catalysis, gas adsorption and separation, and drug delivery. However, porous organic cages are easily soluble in most organic solvents, making them difficult to apply to oil-water separation.

[0004] This invention is the first to extend the polymerization of porous organic cages via Yamamoto coupling reaction into organic cage framework materials (OCFs), reducing the solubility of the porous organic cages while maintaining the main framework. The resulting organic cage framework materials (OCFs) exhibit high hydrophobicity, and their high specific surface area is beneficial for oil-water separation applications. This invention is the first to polymerize porous organic cages via Yamamoto coupling reaction and the first to apply materials based on porous organic cages to the field of oil-water separation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a class of organic cage frameworks (OCFs) synthesized based on the Yamamoto coupling reaction, their preparation method, and their application in oil-water separation. This invention utilizes brominated porous organic cages as the parent material, and synthesizes a porous, stable, and insoluble organic cage framework material based on the Yamamoto coupling reaction with a crosslinking agent in the presence of a catalyst and organic solvent. By changing the type of crosslinking agent, a series of organic cage framework materials were synthesized, exhibiting excellent and stable separation effects on oil-water mixtures.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] The synthetic route and structure of a class of parent materials for organic cage frameworks (OCFs) based on Yamamoto coupling reactions, namely porous organic cages, are as follows:

[0008]

[0009] Aldehyde-functionalized resorcinol calix[4] aryl hydrocarbons were dissolved in a solvent with 5-bromo-1,3-phenylenediamine and added to a pressure-resistant bottle to react at 90°C for 3 days.

[0010] A method for synthesizing organic cage frameworks (OCFs) based on Yamamoto coupling reactions includes the following steps:

[0011] In an organic solvent, a porous organic cage reacts with a crosslinking agent under the catalysis of a catalyst. Then, a certain concentration of hydrochloric acid is added to precipitate the product. After washing and drying, organic cage framework materials (OCFs) are obtained.

[0012] According to the present invention, the organic solvent includes, but is not limited to, one of ethanol, tetrahydrofuran, acetonitrile, 1,4-dioxane, N,N-dimethylformamide, and N,N-dimethylacetamide, preferably a mixed solvent of tetrahydrofuran and N,N-dimethylformamide; preferably, the volume ratio of tetrahydrofuran to N,N-dimethylformamide is 0.5-2:1.

[0013] According to the present invention, the crosslinking agent is preferably 4,4'-dibromobiphenyl, 1,3,5-tris(4-bromophenyl)benzene or tetra(4-bromophenyl)methane.

[0014] According to the present invention, the crosslinking agents each have the following structures:

[0015]

[0016] According to a preferred embodiment of the present invention, the catalyst is Ni(π-C3H5)2, Ni(COD)2 or Ni(CDT); preferably Ni(COD)2.

[0017] According to a preferred embodiment of the present invention, the mass ratio of the porous organic cage, crosslinking agent, catalyst, and organic solvent is 1:(0.05-10):(0.2-2):(10-1000); the most preferred ratio is 1:(0.05-1):(0.75-1.5):(100-500).

[0018] According to the present invention, preferably, the reaction should be carried out under an inert atmosphere to ensure catalyst activity; preferably, it should be carried out in a nitrogen glove box.

[0019] According to the present invention, the reaction temperature is (0-100℃) and the reaction time is 0.5-120h; more preferably, the reaction temperature is 20-30℃ and the reaction time is 24h-48h.

[0020] According to a preferred embodiment of the present invention, the hydrochloric acid is an aqueous solution with a concentration of 1-12 mol / L; more preferably, the hydrochloric acid is an aqueous solution with a concentration of 3-6 mol / L.

[0021] According to a preferred embodiment of the present invention, the drying temperature is 60-100°C.

[0022] According to the above-described organic cage skeleton material of the present invention, it is used as an oil-water separation material for oil-water separation.

[0023] According to the present invention, the oil is an oily substance represented by dichloromethane, trichloromethane, tetrachloromethane, etc.

[0024] The technical features and beneficial effects of this invention are as follows:

[0025] This invention, through Yamamoto coupling, applies porous organic cages, characterized by structural diversity, high crystallinity, and regular pores, to oil-water separation for the first time. Due to their inherent solubility, porous organic cages have not been explored for application in oil-water separation. This invention introduces bromine-functionalized porous organic cages and extends them into organic cage framework materials through Yamamoto coupling, retaining their porous properties while solving the problem of easy solubility. The resulting organic cage framework materials have a large water droplet surface contact angle, strong hydrophobicity, extremely low solubility, and high stability. The resulting series of organic cage framework materials all exhibit excellent oil-water separation performance, with an oil-water separation efficiency greater than 99% and a water contact angle reaching 110°. The obtained materials do not require regeneration and can be used multiple times for oil-water separation, maintaining an oil-water separation efficiency of over 99% even after more than 20 cycles. Attached Figure Description

[0026] Figure 1 This is a single-crystal structure diagram of NKCPOC-Br.

[0027] Figure 2 These are infrared images of NKCPOC-Br and OCFs.

[0028] Figure 3 This is a thermogravimetric diagram of NKCPOC-Br and OCFs.

[0029] Figure 4 Solid-state NMR of NKCPOC-Br, crosslinking agent and OCFs 13 Figure C.

[0030] Figure 5 It is the contact angle of the water droplet surface of OCFs.

[0031] Figure 6 This is a graph showing the oil-water separation efficiency of OCFs. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0033] Example 1

[0034] Synthesis of tetraaldehyde resorcinol calix[4] aromatics (refer to J.Org.Chem.2013,78,22,

[0035] 11597–11601), the specific route is as follows:

[0036]

[0037] Example 2

[0038] The preparation method of NKCPOC-Br is as follows:

[0039]

[0040] Figure 1 This is a single-crystal structure diagram of the bromine-functionalized porous organic cage obtained in Example 2.

[0041] Table 1 shows the structural data of the single-crystal NKCPOC-Br of the bromine-functionalized porous organic cage obtained in Example 2.

[0042] Table 1

[0043]

[0044]

[0045] In Example 3, under a nitrogen atmosphere in a glove box, NKCPOC-Br (900 mg, 0.2 mmol), 4,4'-dibromobiphenyl (124.8 g, 0.4 mmol), Ni(COD)2 (750 mg), cyclooctadiene (368 μL), 2,2'-bipyridine (423.8 mg), tetrahydrofuran (100 mL), and N,N-dimethylformamide (100 mL) were added to a 500 mL flat-bottomed flask and stirred at 30 °C for 1 day. The resulting suspension was removed from the glove box, cooled to room temperature, and 3 mol of hydrochloric acid was slowly added until no more bubbles were produced, at which point a significant precipitate formed. The mixture was filtered, and the resulting residue was washed sequentially with N,N-dimethylformamide (3 × 30 mL), water (3 × 30 mL), and ethanol (3 × 30 mL). The resulting red powder was dried in an oven at 80 °C for 24 h to obtain the organic cage framework OCP-2.

[0046] Example 4

[0047] In a nitrogen-atmospheric glove box, NKCPOC-Br (900 mg, 0.2 mmol), 1,3,5-tris(4-bromophenyl)benzene (217.2 g, 0.4 mmol), Ni(COD)2 (900 mg), cyclooctadiene (405 μL), 2,2'-bipyridine (509 mg), tetrahydrofuran (100 mL), and N,N-dimethylformamide (100 mL) were added to a 500 mL flat-bottomed flask and stirred at 30 °C for 1 day. The resulting suspension was removed from the glove box, cooled to room temperature, and 3 mol of hydrochloric acid was slowly added until no more bubbles were produced, at which point a clear precipitate formed. The mixture was filtered, and the resulting residue was washed successively with N,N-dimethylformamide (3 × 30 mL), water (3 × 30 mL), and ethanol (3 × 30 mL). The resulting red powder was dried in an oven at 80 °C for 24 h to obtain the organic cage framework OCP-3.

[0048] Example 5

[0049] In a nitrogen-atmospheric glove box, NKCPOC-Br (900 mg, 0.2 mmol), tetra(4-bromobenzene)methane (254.4 mg, 0.4 mmol), Ni(COD)2 (1 g), cyclooctadiene (450 μL), 2,2'-bipyridine (565 mg), tetrahydrofuran (100 mL), and N,N-dimethylformamide (100 mL) were added to a 500 mL flat-bottomed flask and stirred at 30 °C for 1 day. The resulting suspension was removed from the glove box, cooled to room temperature, and 3 mol of hydrochloric acid was slowly added until no more bubbles were produced, at which point a clear precipitate formed. The mixture was filtered, and the resulting residue was washed successively with N,N-dimethylformamide (3 × 30 mL), water (3 × 30 mL), and ethanol (3 × 30 mL). The resulting red powder was dried in an oven at 80 °C for 24 h to obtain the organic cage framework OCP-4.

[0050] Figure 2 The infrared spectra of the products obtained in Examples 2-5 are shown in the figure. As can be seen from the figure, the infrared characteristic peaks of C=C, CN, C=O, C=CH of the porous organic cage are all retained, indicating that the basic structure of the porous organic cage in the obtained organic cage skeleton material is retained.

[0051] Figure 3 The thermogravimetric diagrams of the products obtained in Examples 2-5 show that the organic cage skeleton material exhibits excellent thermal stability and meets the temperature requirements for industrial applications.

[0052] Figure 4 Solid-state NMR spectra of the products obtained in Examples 2-5 13 C. As shown in the figure, the obtained organic cage skeleton material is mainly composed of a very small portion of crosslinking agent for the vast majority of porous organic cages.

[0053] Figure 5 The figure shows the water droplet surface contact angles corresponding to the products obtained in Examples 3-5. As can be seen from the figure, the obtained organic cage skeleton material exhibits strong hydrophobicity.

[0054] Example 9

[0055] S1. Take out about 30 mg of the organic cage skeleton material prepared in Examples 2-5 and disperse it evenly in methanol. Use a vacuum filtration method to evenly deposit the powder sample onto commercial filter paper.

[0056] S2. Mix 100ml of oily liquid (dichloromethane, trichloromethane, carbon tetrachloride) and 100ml of water, and sonicate for 1 hour to prepare an oil-water mixture.

[0057] S3. Slowly add the oil-water mixture into the funnel. Place commercial filter paper with sample powder deposited on it at the bottom of the funnel so that the oil-water mixture passes through the filter paper only under the action of gravity.

[0058] S4. Calculate the oil-water separation efficiency according to the formula efficiency = m1 / m0 × 100%, where m1 and m0 are the mass of the oily solution passing through the filter paper and the mass of the added oily liquid, respectively.

[0059] Figure 6 The oil-water separation efficiency of the products obtained in Examples 3-5 for different oily solutions is shown. The oil-water separation efficiency is over 99%, which is extremely high and has broad prospects for industrial application.

[0060] The organic cage skeleton material of this invention, after oil-water separation, can be reused for oil-water separation without any regeneration process. After 20 cycles, the oil-water separation efficiency remains above 99%.

[0061] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. Those skilled in the art can easily make various modifications to these embodiments, including but not limited to modifying the porous organic cage matrix material such as POCs, MOCs, and HOCs; modifying the solvent and ratio used for the ligands; modifying the type, ratio, and amount of catalyst; modifying the type of crosslinking agent; modifying the ratio of the matrix material and the crosslinking agent; modifying the reaction time and temperature; and applying the general principles described herein to other embodiments without inventive effort. Therefore, the present invention is not limited to the embodiments described herein. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A method for preparing an organic cage framework based on Yamamoto coupling reaction, characterized in that: First, an aldehyde-functionalized macrocyclic compound and a brominated aniline were subjected to a hydrothermal reaction under certain conditions to construct a porous organic cage, NKCPOC-Br, as the parent material. Then, NKCPOC-Br, a crosslinking agent, a catalyst, and an organic solvent were reacted at a certain temperature for a certain time to obtain an organic cage framework (OCFs). The porous organic cage was expanded into an organic cage framework through Yamamoto coupling. The aldehyde-functionalized macrocyclic compound was selected from calixarenes and columnar aromatics. The brominated aniline was selected from 5-bromo-1,3-phenylenediamine and 2-bromo-1,4-phenylenediamine. The crosslinking agent was selected from 4,4'-dibromobiphenyl, 1,3,5-tris(4-bromophenyl)benzene, and tetra(4-bromophenyl)methane.

2. The method for preparing the organic cage framework based on the Yamamoto coupling reaction according to claim 1, characterized in that, The solvent is selected from one of ethanol, tetrahydrofuran, acetonitrile, 1,4-dioxane, N,N-dimethylformamide, and N,N-dimethylacetamide; the catalyst is one of Ni(π-C3H5)2, Ni(COD)2, and Ni(CDT).

3. The method for preparing the organic cage framework based on the Yamamoto coupling reaction according to claim 1, characterized in that, The mass ratio of NKCPOC-Br: crosslinking agent: catalyst: organic solvent is 1:(0.05-10):(0.2-2):(10-1000).

4. The method for preparing the organic cage framework synthesized based on the Yamamoto coupling reaction according to claim 1, characterized in that, The Yamamoto coupling reaction is carried out at a temperature of 0 to 100 °C for 0.5 to 120 h; the reaction vessel is selected from glass bottles, round-bottom flasks, or pressure-resistant bottles; the mixing method is selected from stirring or ultrasonication.

5. A class of organic cage frameworks synthesized based on Yamamoto coupling reactions, characterized in that, The organic cage skeleton material (OCFs) is prepared by any one of the methods in claims 1-4.

6. The use of the organic cage framework synthesized based on the Yamamoto coupling reaction according to claim 5, characterized in that, Organic cage frames (OCFs) are used as oil-water separation materials.

7. The use of the organic cage framework synthesized based on the Yamamoto coupling reaction according to claim 6, characterized in that, Using common commercial filter paper as the base material, the organic cage skeleton is evenly dispersed on the filter paper. Under the action of gravity, only the oil layer can pass through the filter paper, thus achieving the separation of oil and water mixtures.

8. The use of the organic cage framework synthesized based on the Yamamoto coupling reaction according to claim 6 or 7, characterized in that, The organic cage frame after oil-water separation does not need to be regenerated before it can be used for the next oil-water separation application.

Images