A liquid-liquid extractant for separating chloride ions, its preparation method, and its application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANXI UNIV
- Filing Date
- 2026-03-13
- Publication Date
- 2026-06-02
AI Technical Summary
[0004]针对现有氯离子液液萃取体系依赖四烷基季铵盐协萃剂、试剂消耗量大、萃取效率偏低、生产成本高昂且难以工业化应用的技术瓶颈，本发明提供一种用于氯离子分离的液液萃取剂及其制备方法
[0023] The extractant of this invention eliminates the need for expensive tetraalkyl quaternary ammonium salts as co-extractants during chloride ion extraction, significantly reducing production costs. It exhibits excellent selectivity for chloride ions and a high extraction efficiency (99%), enabling almost quantitative extraction of chloride ions from the aqueous phase into a dichloromethane solution. The extraction process is simple and rapid, and the extractant can be recycled and regenerated through reverse-phase extraction of chloride ions from the organic phase using pure water. These characteristics make the extractant highly valuable and promising for the cyclic dechlorination treatment of industrial chlorinated wastewater.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of industrial wastewater treatment and resource utilization technology, specifically relating to a liquid-liquid extractant for separating chloride ions, its preparation method, and its application. Background Technology
[0002] With the continuous expansion of industrial production, the discharge of high-concentration chlorine-containing wastewater from industries such as energy and chemical engineering, pharmaceuticals, and mining has shown a year-on-year increasing trend. If this type of wastewater is discharged directly into natural water bodies without effective treatment, it will not only disrupt the original ecological balance of the water bodies and exacerbate water salinization, causing a sharp decline in fishery and aquaculture production, but may also pollute deep groundwater through soil infiltration, thereby threatening the safety of drinking water sources. At the same time, the strong electrochemical corrosiveness of chloride ions will continuously erode steel pipes in industrial pipeline networks, causing hidden dangers such as pipe wall thinning and leakage, significantly shortening the service life of equipment and increasing the operation and maintenance costs of enterprises. In addition, high concentrations of chloride ions will also pose multiple hazards to biological systems—it will interfere with the normal physiological metabolism of poultry and livestock, and when the chloride concentration in drinking water accumulates to a threshold, it can lead to poisoning or even death of livestock and poultry. It can also damage the cell membrane integrity and enzymatic activity of microorganisms in the wastewater biological treatment system by increasing the environmental osmotic pressure, significantly inhibiting the metabolic function of degrading bacteria, and ultimately causing a significant decrease in wastewater treatment efficiency. Currently, conventional chlorine removal technologies such as chemical precipitation, membrane separation, adsorption, electrolysis, and evaporation crystallization still have room for improvement in terms of treatment efficiency and adaptability to various application scenarios, making it difficult to simultaneously meet the dual requirements of efficient purification and resource recovery of industrial chlorine-containing wastewater. Therefore, researchers are continuously exploring more efficient and environmentally friendly chlorine removal technologies. Among these, solvent extraction, with its advantages of high separation efficiency, simple equipment processes, and ease of continuous operation and automated control, has become a promising technology for industrial application.
[0003] Among the reported chloride ion liquid-liquid extraction systems, the neutral acceptor-tetraalkyl quaternary ammonium salt binary co-extraction system is one of the research hotspots. This system is inspired by the mature metal ion co-extraction technology in hydrometallurgy, utilizing a neutral anion acceptor for chloride ion extraction. - The specific recognition and phase transfer ability of quaternary ammonium salts work synergistically to achieve Cl in the aqueous phase - Highly efficient separation is achieved. However, such systems have significant drawbacks: firstly, tetraalkyl quaternary ammonium salts are expensive and prone to dissolution at the water-organic interface, resulting in high reagent consumption and processing costs; secondly, most systems suffer from low extraction efficiency and insufficient cycle stability due to factors such as the synergistic matching between the neutral acceptor and the quaternary ammonium salt, and the control of back-extraction conditions. These shortcomings collectively restrict the industrialization of such systems. Therefore, developing a single chloride ion extractant that requires no co-extractant and possesses both high selectivity and high extraction efficiency has become a core research direction in the field of liquid-liquid extraction. Summary of the Invention
[0004] To address the technical bottlenecks of existing chloride ion liquid-liquid extraction systems, which rely on tetraalkyl quaternary ammonium salt co-extractants, resulting in high reagent consumption, low extraction efficiency, high production costs, and limited industrial application, this invention provides a liquid-liquid extractant for chloride ion separation and its preparation method. This extractant eliminates the need for a co-extractant during chloride ion extraction, exhibits both high selectivity and high extraction efficiency for chloride ions, and requires only pure water for back-extraction of the chloride-loaded organic phase, enabling the regeneration of the extractant. It demonstrates significant application value and industrialization prospects in the cyclic dechlorination treatment of industrial chlorinated wastewater.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0006] A liquid-liquid extractant for separating chloride ions, the molecular formula of the liquid-liquid extractant being: C 52 H 76 N 12 O4; the structural formula is:
[0007] .
[0008] A method for preparing a liquid-liquid extractant includes the following steps:
[0009] Step 1: Propyleneamine is reacted with 1,2-bis(2-iodoethoxy)ethane to generate the intermediate N,N'-dipropyne-1,10-diaza-18-crown-6-ether (E 1 );
[0010] Step 2, using the intermediate N,N'-diazepine-1,10-diaza-18-crown-6-ether (E 1 It undergoes a click reaction with 6-azido-2-hexanone to generate the intermediate N,N'-bis(6-oxohexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether (E 2 );
[0011] Step 3, under the catalysis of trifluoroacetic acid, the intermediate N,N'-bis(6-oxohexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether (E 2 The condensation of pyrrole yields the intermediate N,N'-bis(5,5-dipyrrolithyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether (E 3 ).
[0012] Step 4, under the catalysis of boron trifluoride diethyl ether, the intermediate N,N'-bis(5,5-dipyrrolithyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether (E 3The liquid-liquid extractant meso-hexamethyl-meso-bis(4-(1-triazolylmethylene)butyl)-1,10-diaza-18-crown-6-ether calix[4]pyrrole (E) was obtained by condensation reaction of meso-hexamethyl-meso-bis(4-(1-triazolylmethylene)butyl)-1,10-diaza-18-crown-6-ether calix[4]pyrrole.
[0013] Further, the specific process of step 1 is as follows: An equimolar amount of propargylamine and 1,2-bis(2-iodoethoxy)ethane are dissolved in acetonitrile, then 3-5 times the volume of sodium carbonate is added, the mixture is heated under reflux for 24 h, the solvent is removed under reduced pressure, and the residue is separated by column chromatography to obtain the intermediate N,N'-dipropargyl-1,10-diaza-18-crown-6-ether (E 1 );
[0014] Intermediate N,N'-dipropynyl-1,10-diaza-18-crown-6-ether (E 1 The chemical structural formula of ) is: .
[0015] Further, the specific process of step 2 is as follows: N,N'-diamylacetyl-1,10-diaza-18-crown-6-ether (E 1 Dissolve the compound in DMF, then add 2 molar amounts of 6-azido-2-hexanone, followed by 0.1–0.4 molar amounts of copper sulfate and 0.2–0.8 molar amounts of sodium ascorbate. Stir at room temperature for 24 h, remove the solvent under reduced pressure, and separate the residue by column chromatography to obtain the intermediate N,N'-bis(6-oxohexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether (E 2 );
[0016] Intermediate N,N'-bis(6-oxohexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether (E 2 The chemical structural formula of ) is:
[0017] .
[0018] Further, the specific process of step 3 is as follows: N,N'-bis(6-oxohexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether (E 2 Dissolved in pyrrole, then 2-4 molar amounts of trifluoroacetic acid were added. The mixture was heated to 60 °C and stirred for 1 h. After cooling, triethylamine was added to quench the reaction. The solvent was removed under reduced pressure. The residue was separated by column chromatography to obtain the intermediate N,N'-bis(5,5-dipyrrolithyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether (E 3 );
[0019] Intermediate N,N'-bis(5,5-dipyrrolithyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether (E 3 The chemical structural formula of ) is: .
[0020] Further, the specific process of step 4 is: N,N'-bis(5,5-dipyrrolithyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether (E 3 Dissolved in acetone, 1-3 moles of 47% boron trifluoride diethyl ether solution were added with stirring, and then reacted at room temperature for 12 h. Triethylamine was added to quench the reaction, and the solvent was removed under reduced pressure. The residue was separated by column chromatography to obtain the liquid-liquid extractant meso-hexamethyl-meso-bis(4-(1-triazolylmethylene)butyl)-1,10-diaza-18-crown-6-ether calix[4]pyrrole (E).
[0021] The application of a liquid-liquid extractant prepared by the above method in the cyclic dechlorination treatment of industrial chlorine-containing wastewater.
[0022] Compared with the prior art, the present invention has the following advantages:
[0023] The extractant of this invention eliminates the need for expensive tetraalkyl quaternary ammonium salts as co-extractants during chloride ion extraction, significantly reducing production costs. It exhibits excellent selectivity for chloride ions and a high extraction efficiency (99%), enabling almost quantitative extraction of chloride ions from the aqueous phase into a dichloromethane solution. The extraction process is simple and rapid, and the extractant can be recycled and regenerated through reverse-phase extraction of chloride ions from the organic phase using pure water. These characteristics make the extractant highly valuable and promising for the cyclic dechlorination treatment of industrial chlorinated wastewater. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a flowchart of the extraction agent preparation method of the present invention.
[0026] Figure 2 The extractant E of this invention 1 HNMR nuclear magnetic resonance spectrum.
[0027] Figure 3 This is a high-resolution mass spectrum of extractant E in this invention.
[0028] Figure 4 For the selective extraction experiment of chloride ions in this invention 1 H NMR spectrum.
[0029] Figure 5 This invention relates to a reversible cyclic experiment for extracting chloride ions. 1 H NMR spectrum. Detailed Implementation
[0030] To gain a deeper understanding of this invention, we will provide a comprehensive and detailed description. However, this invention has various implementations and is not limited to the specific examples listed herein. These examples are presented to enhance a full understanding of the disclosure of this invention.
[0031] Example 1:
[0032] Preparation of a liquid-liquid extractant for removing chloride ions:
[0033] (1) Intermediate E 1 Preparation: Propyleneamine (2.30 g, 40 mmol) and 1,2-1,2-bis(2-iodoethoxy)ethane (14.8 g, 40 mmol) were dissolved in 150 mL of acetonitrile, and then sodium carbonate (1.32 g, 120 mmol) was added. The mixture was refluxed for 24 h, and the solvent was removed under reduced pressure. The residue was separated by column chromatography. The method was as follows: a flash column with sand plates and an inner diameter of 50 mm was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel, and a mixed solvent with a volume ratio of n-hexane:isopropanol = 100:10 was used as the eluent. 2.01 g of product was obtained, with a yield of 30%.
[0034] (2) Intermediate E 2 Preparation of E: 1 (2.00 g, 5.90 mmol) was dissolved in 200 mL DMF, and then 6-azido-2-hexanone (1.67 g, 11.80 mmol) was added, followed by CuSO4•5H2O (0.15 g, 0.59 mmol) and NaAsc (0.24 g, 1.18 mmol). The mixture was stirred at room temperature for 24 h, poured into 500 mL of water, and extracted three times with dichloromethane. The organic phase was dried over anhydrous sodium sulfate, filtered, and the solvent was removed under reduced pressure. The residue was separated by column chromatography using the following method: a 50 mm inner diameter flash column with sand plates was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel, and a mixed solvent of n-hexane:isopropanol = 10:1 (v / v) was used as the eluent. 1.40 g of product was obtained, with a yield of 38%.
[0035] (3) Intermediate E 3 Preparation of E: 2 (1.00 g, 1.62 mmol) was dissolved in 15 mL of pyrrole, and then trifluoroacetic acid (0.37 g, 3.24 mmol) was added. The mixture was heated to 60 °C and stirred for 1 h. After cooling, triethylamine was added to quench the reaction, and the solvent was removed under reduced pressure. The residue was separated by column chromatography. The method was as follows: a flash column with sand plates and an inner diameter of 50 mm was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel, and a mixed solvent with a volume ratio of dichloromethane:n-hexane:isopropanol = 100:100:10 was used as the eluent. 0.81 g of product was obtained, with a yield of 59%.
[0036] (4) Preparation of intermediate E: E 3 (1.16 g, 1.24 mmol) was dissolved in 600 mL of acetone, and boron trifluoride diethyl ether solution (0.40 mL, 1.24 mmol) was added with stirring. The reaction was then carried out at room temperature for 12 h. The mixture was quenched with triethylamine, and the solvent was removed under reduced pressure. The residue was separated by column chromatography. The method was as follows: a flash column with sand plates and an inner diameter of 50 mm was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel, and a mixed solvent with a volume ratio of dichloromethane:n-hexane:isopropanol = 100:100:10 was used as the eluent. 93 mg of product was obtained, with a yield of 8%.
[0037] Example 2
[0038] Preparation of a liquid-liquid extractant for removing chloride ions:
[0039] (1) Intermediate E 1 Preparation: Propyleneamine (2.30 g, 40 mmol) and 1,2-1,2-bis(2-iodoethoxy)ethane (14.8 g, 40 mmol) were dissolved in 150 mL of acetonitrile, and then sodium carbonate (1.32 g, 160 mmol) was added. The mixture was refluxed for 24 h, and the solvent was removed under reduced pressure. The residue was separated by column chromatography. The method was as follows: a flash column with sand plates and an inner diameter of 50 mm was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel, and a mixed solvent with a volume ratio of n-hexane:isopropanol = 100:10 was used as the eluent. 2.86 g of product was obtained, with a yield of 42%.
[0040] (2) Intermediate E 2 Preparation of E: 1(2.00 g, 5.90 mmol) was dissolved in 200 mL DMF, and then 6-azido-2-hexanone (1.67 g, 11.80 mmol) was added, followed by CuSO4•5H2O (0.30 g, 1.18 mmol) and NaAsc (0.48 g, 2.36 mmol). The mixture was stirred at room temperature for 24 h, poured into 500 mL of water, and extracted three times with dichloromethane. The organic phase was dried over anhydrous sodium sulfate, filtered, and the solvent was removed under reduced pressure. The residue was separated by column chromatography: a 50 mm inner diameter flash column with sand plates was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel, and a mixed solvent of n-hexane:isopropanol = 10:1 (v / v) was used as the eluent. 1.98 g of product was obtained, with a yield of 54%.
[0041] (3) Intermediate E 3 Preparation of E: 2 (1.00 g, 1.62 mmol) was dissolved in 15 mL of pyrrole, and then trifluoroacetic acid (0.37 g, 4.86 mmol) was added. The mixture was heated to 60 °C and stirred for 1 h. After cooling, triethylamine was added to quench the reaction. The solvent was removed under reduced pressure. The residue was separated by column chromatography. The method was as follows: a flash column with a sand plate and an inner diameter of 50 mm was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel. A mixed solvent with a volume ratio of dichloromethane:n-hexane:isopropanol = 100:100:10 was used as the eluent to separate 1.14 g of product, with a yield of 83%.
[0042] (4) Preparation of intermediate E: E 3 (1.16 g, 1.24 mmol) was dissolved in 600 mL of acetone, and boron trifluoride diethyl ether solution (0.80 mL, 2.48 mmol) was added with stirring. The reaction was then carried out at room temperature for 12 h. Triethylamine was added to quench the reaction, and the solvent was removed under reduced pressure. The residue was separated by column chromatography. The method was as follows: a flash column with sand plates and an inner diameter of 50 mm was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel, and a mixed solvent with a volume ratio of dichloromethane:n-hexane:isopropanol = 100:100:10 was used as the eluent. 0.13 g of product was obtained, with a yield of 11%.
[0043] Example 3
[0044] Preparation of a liquid-liquid extractant for removing chloride ions:
[0045] (1) Intermediate E 1Preparation: Propyleneamine (2.30 g, 40 mmol) and 1,2-1,2-bis(2-iodoethoxy)ethane (14.8 g, 40 mmol) were dissolved in 150 mL of acetonitrile, and then sodium carbonate (1.32 g, 200 mmol) was added. The mixture was refluxed for 24 h, and the solvent was removed under reduced pressure. The residue was separated by column chromatography. The method was as follows: a flash column with sand plates and an inner diameter of 50 mm was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel, and a mixed solvent with a volume ratio of n-hexane:isopropanol = 100:10 was used as the eluent. 3.05 g of product was obtained, with a yield of 45%.
[0046] (2) Intermediate E 2 Preparation of E: 1 (2.00 g, 5.90 mmol) was dissolved in 200 mL DMF, and then 6-azido-2-hexanone (1.67 g, 11.80 mmol) was added, followed by CuSO4•5H2O (0.60 g, 2.36 mmol) and NaAsc (0.48 g, 4.72 mmol). The mixture was stirred at room temperature for 24 h, poured into 500 mL of water, and extracted three times with dichloromethane. The organic phase was dried over anhydrous sodium sulfate, filtered, and the solvent was removed under reduced pressure. The residue was separated by column chromatography using the following method: a 50 mm inner diameter flash column with sand plates was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel, and a mixed solvent of n-hexane:isopropanol = 10:1 (v / v) was used as the eluent. 3.00 g of product was obtained, with a yield of 82%.
[0047] (3) Intermediate E 3 Preparation of E: 2 (1 g, 1.62 mmol) was dissolved in 15 mL of pyrrole, and then trifluoroacetic acid (0.37 g, 6.48 mmol) was added. The mixture was heated to 60 °C and stirred for 1 h. After cooling, triethylamine was added to quench the reaction. The solvent was removed under reduced pressure. The residue was separated by column chromatography. The method was as follows: a flash column with sand plates and an inner diameter of 50 mm was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel. A mixed solvent with a volume ratio of dichloromethane:n-hexane:isopropanol = 100:100:10 was used as the eluent to separate 1.21 g of product, with a yield of 88%.
[0048] (4) Preparation of intermediate E: E 3(1.16 g, 1.36 mmol) was dissolved in 600 mL of acetone, and boron trifluoride diethyl ether solution (1.20 mL, 3.72 mmol) was added with stirring. The reaction was then carried out at room temperature for 12 h. The reaction was quenched with triethylamine, and the solvent was removed under reduced pressure. The residue was separated by column chromatography. The method was as follows: a flash column with sand plates and an inner diameter of 50 mm was packed with 100-200 mesh silica gel to a height of 20 cm. The residue to be separated was added above the silica gel, and a mixed solvent with a volume ratio of dichloromethane:n-hexane:isopropanol = 100:100:10 was used as the eluent. 0.15 g of product was obtained, with a yield of 13%.
[0049] Example 4
[0050] Chloride ion liquid-liquid extraction was performed using extractant E from Example 3.
[0051] (1) Extraction performance and selective extraction experiment: 0.5 mL of a 4 mM CD₂Cl₂ solution containing the main molecule E was added to an NMR tube, followed by 0.5 M aqueous solutions of a single alkali metal chloride (LiCl, NaCl, KCl, or RbCl). The mixture was shaken by hand and allowed to stand for 1 min until the two phases were completely separated. The organic phase was then immediately measured. 1 H NMR spectrum (with) Figure 4 Experimental results show that in single-ion systems, the host molecule E exhibits excellent extraction capabilities for LiCl, NaCl, KCl, and RbCl. The characteristic signal peaks of E in the organic phase completely disappear in all four systems, while a new set of characteristic signal peaks appears. This indicates that E forms stable complexes with alkali metal ions and chloride ions in the organic phase. Based on the detection sensitivity analysis using 1H NMR spectroscopy, the residual E content in the organic phase is less than 1%, indicating that the host E achieves an extraction efficiency of over 99% for alkali metal chlorides, approaching quantitative levels.
[0052] To further investigate the recognition selectivity of E, an ion-competitive extraction experiment was conducted. An aqueous solution containing equimolar amounts (0.5 M each) of LiCl, NaCl, KCl, and RbCl was added to the organic solution of E. After the same extraction procedure, the organic phase was measured. 1 H NMR spectrum (with) Figure 4 f). The results show that in the mixed system, the characteristic signal peak of E in the organic phase still completely disappeared, and the obtained spectrum was the same as that when only NaCl was added. Figure 1 This indicates that although E has high extraction capacity for all four alkali metal chlorides, under equimolar competition conditions, E still preferentially coordinates with NaCl. Therefore, host E exhibits significant selectivity for NaCl.
[0053] (2) Reversible Cycling Experiment: To investigate the reversibility of the system, the organic phase containing NaCl was separated from the aqueous phase, and 0.5 mL of deionized water was added to the organic phase. After shaking and phase separation for 1 min, the NMR spectrum was immediately measured. Figure 5 c). The spectrum shows that the signal peak of the main component E reappears in the organic phase, indicating that E reacts with Cl. - It undergoes dissociation through coordination with Na⁺.
[0054] Subsequently, the upper aqueous phase was removed, and the organic phase was thoroughly washed with deionized water to remove residual salts. A second extraction was performed using 0.5 M NaCl aqueous solution, and the NMR spectrum was recorded. Figure 5 d). Experimental results show that after the above regeneration process, the main body E can still extract NaCl efficiently, and its extraction performance has almost no decline compared with the first use, proving that the extractant has excellent stability for recycling.
[0055] Contents not described in detail in this specification are prior art known to those skilled in the art. Although illustrative specific embodiments of the invention have been described above to facilitate understanding by those skilled in the art, it should be understood that the invention is not limited to the scope of the specific embodiments. Various modifications are readily apparent to those skilled in the art as long as they fall within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of this invention are protected.
Claims
1. A liquid-liquid extractant for separating chloride ions, characterized in that, The molecular formula of the liquid-liquid extractant is: C 52 H 76 N 12 O4; the structural formula is: 。 2. A method for preparing the liquid-liquid extractant as described in claim 1, characterized in that, Includes the following steps: Step 1: Reaction of propargylamine with 1,2-bis(2-iodoethoxy)ethane to generate intermediate N,N'-dipropargyl-1,10-diaza-18-crown-6-ether; Step 2: The intermediate N,N'-dipropynyl-1,10-diaza-18-crown-6-ether is reacted with 6-azido-2-hexanone in a click reaction to generate the intermediate N,N'-bis(6-oxohexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether. Step 3: Under the catalysis of trifluoroacetic acid, the intermediate N,N'-bis(6-oxohexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether is condensed with pyrrole to obtain the intermediate N,N'-bis(5,5-dipyrrolithylhexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether; Step 4: Under the catalysis of boron trifluoride ether, the intermediate N,N'-bis(5,5-dipyrrolithyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether is condensed with acetone to obtain the liquid-liquid extractant meso-hexamethyl-meso-bis(4-(1-triazolylmethylene)butyl)-1,10-diaza-18-crown-6-etherylcalix[4]pyrrole.
3. The preparation method according to claim 2, characterized in that, The specific process of step 1 is as follows: equimolar amounts of propargylamine and 1,2-bis(2-iodoethoxy)ethane are dissolved in acetonitrile, then 3 to 5 times the volume of sodium carbonate of propargylamine is added, the mixture is heated under reflux for 24 h, the solvent is removed under reduced pressure, and the residue is separated by column chromatography to obtain the intermediate N,N'-dipropargyl-1,10-diaza-18-crown-6-ether; The chemical structural formula of the intermediate N,N'-diazepine-1,10-diaza-18-crown-6-ether is as follows: .
4. The preparation method according to claim 2, characterized in that, The specific process of step 2 is as follows: N,N'-dipropynyl-1,10-diaza-18-crown-6-ether is dissolved in DMF, then 2 molar amounts of 6-azido-2-hexanone are added, followed by 0.1~0.4 molar amounts of copper sulfate and 0.2~0.8 molar amounts of sodium ascorbate. The mixture is stirred at room temperature for 24 h, and the solvent is removed under reduced pressure. The residue is separated by column chromatography to obtain the intermediate N,N'-bis(6-oxohexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether. The chemical structural formula of the intermediate N,N'-bis(6-oxohexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether is as follows: 。 5. The preparation method according to claim 2, characterized in that, The specific process of step 3 is as follows: N,N'-bis(6-oxohexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether is dissolved in pyrrole, and then 2-4 molar amounts of trifluoroacetic acid are added. The mixture is heated to 60 °C and stirred for 1 h. After cooling, triethylamine is added to quench the reaction. The solvent is removed under reduced pressure. The residue is separated by column chromatography to obtain the intermediate N,N'-bis(5,5-dipyrrolithylhexyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether. The chemical structural formula of the intermediate N,N'-bis(5,5-dipyrrolithyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether is as follows: 。 6. The preparation method according to claim 2, characterized in that, The specific process of step 4 is as follows: N,N'-bis(5,5-dipyrrolithyl-1-triazolylmethylene)-1,10-diaza-18-crown-6-ether is dissolved in acetone, and 1-3 moles of boron trifluoride diethyl ether solution is added under stirring. Then, the reaction is carried out at room temperature for 12 h, and triethylamine is added to quench the reaction. The solvent is removed under reduced pressure, and the residue is separated by column chromatography to obtain the liquid-liquid extractant meso-hexamethyl-meso-bis(4-(1-triazolylmethylene)butyl)-1,10-diaza-18-crown-6-ether calix[4]pyrrole.
7. The application of a liquid-liquid extractant prepared by any one of claims 2 to 6 in the cyclic dechlorination treatment of industrial chlorine-containing wastewater.