An amide macrocycle for fluoride ion recognition and its preparation method and application

Abstract

The present invention discloses an amide macrocycle for fluoride ion recognition, a preparation method thereof, and an application thereof, belonging to the technical field of design of supramolecular chemistry macrocyclic bodies and host-guest recognition. The macrocyclic aromatic amide body is prepared by Suzuki coupling reaction and condensation reaction. The macrocyclic receptor is mainly composed of three 2,6-pyridinediamide molecular fragments and three biphenyl molecular fragments. The molecule prepared by the present invention contains a huge cavity inside and contains abundant hydrogen bond recognition sites. It can selectively recognize fluoride ions in solution through hydrogen bond interactions, and the complexation constant for fluoride ions is as high as 10 4 M ‑1 The preparation process of the present invention is simple and the raw materials are readily available. It has potential application prospects in the fields of fluoride detection and removal of fluorine-containing pollutants.

Description

Technical Field

[0001] The present invention belongs to the technical field of supramolecular chemical macrocyclic main body design and host-guest recognition, and specifically relates to an amide macrocycle for fluoride ion recognition, and a preparation method and application thereof. Background Art

[0002] Anions play a well-known role in our daily lives. Among the many biologically important anions, fluoride is the smallest anion found naturally in the environment. It is crucial for the healthy development of teeth and the proper functioning of various bodily organs. In addition to its biological functions, fluoride is also required as a necessary chemical processing reagent in a variety of modern high-tech technologies and industrial products, such as quartz glass engraving, precious metal recycling, and the production of fertilizers and semiconductor materials. Consequently, the industrial wastewater, solid waste, and exhaust gases generated by these industries inevitably contain significant amounts of fluoride or hydrofluoric acid, leading to significant environmental pollution. Therefore, the optimal use of fluoride while minimizing its environmental pollution and harm to the body has been a key research topic for many years.

[0003] In recent years, people have found that anion recognition receptors have potential for wide applications in the fields of anion sensing and extraction, catalysis and transmembrane transport. Today, the construction of supramolecular hosts with anion recognition function has become a hot research field in supramolecular chemistry. Among the many supramolecular anion recognition receptors, the structure of the macrocyclic aromatic amide host is basically rigid due to the presence of intramolecular hydrogen bonds, and usually has a persistent or non-foldable shape. At the same time, 2,6-pyridinediamide is a molecular fragment of an effective anion receptor. The "V"-shaped semi-enclosed region it forms can selectively recognize specific anionic species. The introduction of this functional group can increase the selectivity of the macrocyclic aromatic amide host for anion recognition. However, the macrocyclic aromatic amide hosts synthesized in the prior art often show similar affinity for anions other than fluoride ions in anion recognition, making it difficult to highly selectively recognize fluoride ions in highly polar solutions. Summary of the Invention

[0004] To solve the above problems, the present invention aims to provide an amide macrocycle for fluoride ion recognition, and a preparation method and application thereof.

[0005] To achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions:

[0006] An amide macrocycle for fluoride ion recognition has the following structural formula:

[0007]

[0008] Wherein R is a C1-C16 alkane group, and n=1-3.

[0009] The method for preparing the amide macrocycle for fluoride ion recognition comprises the following steps:

[0010] 1) Compound 1 and Compound 2 are dissolved in an organic solvent, water and a base are added, the mixture is stirred and mixed uniformly, and the mixture is heated to 80-150° C. in an argon environment. A catalyst is then added thereto and the reaction is carried out for 10-24 hours. After the reaction is completed, the pH value of the solution is adjusted to 6.5-7 using hydrochloric acid. The resulting reaction solution is distilled under reduced pressure to remove the solvent. The resulting residue is purified by column chromatography using a solvent having a volume ratio of dichloromethane to methanol of 50-100:1 as a developing solvent to obtain an intermediate diamine product;

[0011] The structural formula of the compound 1 is Wherein R is a C1-C16 alkane group;

[0012] The structural formula of compound 2 is Where n = 1 to 3;

[0013] 2) The intermediate diamine product prepared in step 1) and 2,6-pyridinedicarboxylic acid are added to an organic solvent 2, and then 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole are added thereto, and the mixture is heated to 55-80° C. and reacted for 4-5 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and the resulting residue is purified by column chromatography using a solvent having a volume ratio of dichloromethane to methanol of 40-60:1 as a developing solvent, and then recrystallized to obtain an amide macrocycle for fluoride ion recognition.

[0014] The organic solvent in step 1) is dioxane or dimethylformamide.

[0015] The base in step 1) is potassium carbonate or sodium carbonate.

[0016] The catalyst in step 1) is tetrakis(triphenylphosphine)palladium or bis(triphenylphosphine)palladium dichloride.

[0017] The volume ratio of the organic solvent to water in step 1) is 4 to 8:1.

[0018] The molar ratio of compound 1, compound 2, base and catalyst in step 1) is 1:2-2.5:5-8:0.01-0.02.

[0019] The organic solvent 2 in step 2) is tetrahydrofuran or dichloromethane.

[0020] The molar ratio of 2,6-pyridinedicarboxylic acid, intermediate diamine product, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole in step 2) is 1:1-1.5:2-4:2-4.

[0021] The solvent used for the recrystallization in step 2) is a mixed solution of petroleum ether and dichloromethane in a volume ratio of 10:1.

[0022] Preferably, the compound 1 in step 1) is The compound 2 is The organic solvent is dioxane; the base is potassium carbonate; the catalyst is tetrakis(triphenylphosphine)palladium; the molar ratio of compound 1, compound 2, base and catalyst is 1:2:6:0.01; the volume ratio of the organic solvent and water in step 1) is 5:1.

[0023] Preferably, the organic solvent 2 in step 2) is tetrahydrofuran; the heating is to 65° C.; the molar ratio of the 2,6-pyridinedicarboxylic acid, the intermediate diamine product, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole is 1:1:3:3.

[0024] The present invention also includes the application of the amide macrocycle for fluoride ion recognition in host-guest recognition, fluoride detection and removal of fluorine-containing pollutants.

[0025] The synthetic route of the amide macrocycle for fluoride ion recognition of the present invention is:

[0026]

[0027] Wherein R is a C1-C16 alkane group, and n=1-3.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] The amide macrocycle for fluoride ion recognition of the present invention is a supramolecular macrocyclic aromatic amide main compound based on 2,6-pyridinediamide, and is prepared through a two-step reaction of Suzuki coupling reaction and condensation reaction. By studying the recognition process of the amide macrocyclic aromatic amide main molecule for fluoride ion recognition for various anions such as halogen, bisulfate, and trifluoromethanesulfonate, it was confirmed that the amide macrocycle for fluoride ion recognition has extremely high selective recognition ability for fluoride ions in highly polar solutions, and the color change phenomenon caused by binding with fluoride ions that can be observed with the naked eye is attributed to the fact that the amide macrocycle for fluoride ion recognition has a large cavity and contains abundant hydrogen bond recognition sites, forming multiple hydrogen bond interactions with fluoride ions in solution.

[0030] The amide macrocycle for fluoride ion recognition of the present invention is a rigid molecule with a "saddle-shaped" structure in three-dimensional space. The macrocycle structure has a large spatial size, which is conducive to accommodating more anionic guests. It can have high selectivity and binding strength for fluoride ions in a highly polar solvent environment. The amide macrocycle for fluoride ion recognition can form a 1:3 complex with fluoride ions, and the binding constant is as high as 10 4 M -1 , which can be applied to host-guest identification, fluoride detection and removal of fluorine-containing pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the intermediate diamine product prepared in Example 1 of the present invention;

[0032] Figure 2 This is a high-resolution mass spectrum of the intermediate diamine product prepared in Example 1 of the present invention;

[0033] Figure 3 This is a hydrogen nuclear magnetic resonance spectrum of the amide macrocycle for fluoride ion recognition prepared in Example 1 of the present invention;

[0034] Figure 4 This is a high-resolution mass spectrum of the amide macrocycle for fluoride ion recognition prepared in Example 1 of the present invention;

[0035] Figure 5 This is a proton nuclear magnetic resonance spectrum of the amide macrocycle for fluoride ion recognition prepared in Example 1 of the present invention after adding 5 equivalents of fluoride ion, chloride ion, bromide ion, iodide ion, bisulfate and triflate in deuterated dimethyl sulfoxide (DMSO-d6);

[0036] Figure 6 This is a color change diagram of the amide macrocycle for fluoride ion recognition prepared in Example 1 of the present invention after adding anions;

[0037] Figure 7 This is a UV-visible absorption spectrum of the amide macrocycle for fluoride ion recognition prepared in Example 1 of the present invention after adding 5 equivalents of fluoride ion, chloride ion, bromide ion, iodide ion, bisulfate and trifluoromethanesulfonate in dimethyl sulfoxide. DETAILED DESCRIPTION

[0038] In order to better understand the technical solutions of the present invention, the following is a further detailed description of the above content of the present invention through specific implementation methods in the form of examples. However, this should not be construed as limiting the scope of the above subject matter of the present invention to the following examples. All technologies implemented based on the above content of the present invention fall within the scope of the present invention.

[0039] Example 1 1) 1,3-dibromo-5-methoxybenzene 1.50 g and 4-aminophenylboronic acid pinacol ester 2.47 g were dissolved in 180 ml of a mixed solution of dioxane and water in a volume ratio of 5:1, 4.67 g of potassium carbonate was added, and the mixture was stirred and mixed evenly. The mixture was heated to 100 ° C. in an argon environment, and 0.13 g of tetrakis(triphenylphosphine)palladium was added thereto. The reaction was allowed to react for 12 hours. After the reaction was completed, the pH value of the solution was adjusted to 7 with hydrochloric acid, and the solvent was removed by distillation under reduced pressure. The residue was developed using a solvent of dichloromethane and methanol in a volume ratio of 80:1. The mixture was purified by column chromatography to obtain 1.41 g of an intermediate diamine product with a yield of 86.11%. The obtained intermediate diamine product was characterized by nuclear magnetic resonance and high-resolution mass spectrometry, and its detection spectrum was as shown below. Figure 1 and Figure 2 As shown. 1 HNMR (400MHz, DMSO-d6) δ7.44-7.38(m,4H),7.23(t,J=1.6Hz,1H),6.90(d,J=1.5Hz,2H),6.66-6.60(m,4H),5.23(s,4H),3.83(s,3H). 13 C NMR (101MHz, DMSO-d6) δ160.05,148.37,142.37,127.62,127.27,115.27,114.03,108.44,54.98. HRMS(ESI)for C 19 H 18 N2O,m / z,[M+H] + ,Calculated:290.3660,Found:291.1491.

[0040] 2) 1.41 g of the intermediate diamine product obtained in step 1) and 0.81 g of 2,6-pyridinedicarboxylic acid were added to 150 ml of tetrahydrofuran, and then 2.79 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.97 g of 1-hydroxybenzotriazole were added thereto, and the mixture was heated to 65°C for 5 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The obtained residue was developed using a solvent of dichloromethane and methanol in a volume ratio of 50:1, and purified by column chromatography. The residue was then recrystallized using a mixed solution of petroleum ether and dichloromethane in a volume ratio of 10:1 to obtain an amide macrocycle for fluoride ion recognition. The obtained amide macrocycle for fluoride ion recognition was characterized by nuclear magnetic resonance and high-resolution mass spectrometry, and its detection spectrum was as follows: Figure 3 and Figure 4 As shown. 1H NMR (400MHz, DMSO-d6) δ11.16(s,1H),8.45(d,J=7.7Hz,1H),8.34(dd,J=8.5,6.9Hz, 1H), 8.03 (d, J = 8.4Hz, 2H), 7.88 (d, J = 8.3Hz, 2H), 7.22 (d, J = 1.4Hz, 1H), 3.92 (s, 1H). 13 C NMR (101MHz, DMSO-d6) δ161.90,160.29,148.97,141.92,137.65,136.31,134.17,127.39,125.36,121.64,118.74,111.55,55.46. HRMS(ESI)for C 78 H 57 N9O9Na,m / z,[M+Na] + ,Calculated:1286.3572,Found:1286.4171.

[0041] Example 2 1) 1 g of 1,3-dibromo-5-methoxy and 2.79 g of 4-{4-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]phenyl}aniline were dissolved in 150 ml of a mixed solution of dioxane and water in a volume ratio of 4:1, 3.11 g of potassium carbonate was added, and the mixture was stirred and mixed evenly. The mixture was heated to 80°C in an argon environment, and 0.09 g of tetrakis(triphenylphosphine)palladium was added thereto. The mixture was reacted for 24 hours. After the reaction was completed, the pH value of the solution was adjusted to 6.5 with hydrochloric acid, and the solvent was removed by distillation under reduced pressure. The residue was developed using a solvent of dichloromethane and methanol in a volume ratio of 50:1, and purified by column chromatography to obtain 1.78 g of an intermediate diamine product with a yield of 79.61%. The obtained intermediate diamine product was characterized by nuclear magnetic resonance. 1 H NMR(400MHz,DMSO-d6)δ7.78-7.73(m,4H),7.70(t,J=2.2Hz,1H),7.68-7.63(m,12H), 7.51-7.46(m,4H),7.25(d,J=2.2Hz,2H),6.76-6.61(m,4H),5.36(s,4H),3.81(s,3H). 13CNMR(101MHz,DMSO-d6)δ159.72,148.00,140.90,140.88,140.87,140.67,140.27,135.74,130.43 ,128.09,127.97,127.94,127.90,127.86,127.85,127.83,127.66,123.31,115.76,111.21,55.62.

[0042] 2) 1.78 g of the intermediate diamine product obtained in step 1) and 0.50 g of 2,6-pyridinedicarboxylic acid were added to 150 ml of tetrahydrofuran, and 2.29 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.62 g of 1-hydroxybenzotriazole were added thereto. The mixture was heated to 80° C. and reacted for 5 h. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The resulting residue was purified by column chromatography using a solvent having a volume ratio of dichloromethane and methanol of 40:1 as a developing solvent, and then recrystallized using a mixed solution of petroleum ether and dichloromethane having a volume ratio of 10:1 to obtain an amide macrocycle for fluoride ion recognition.

[0043] Example 3 1) 1 g of 1,3-dibromo-5-ethoxybenzene and 1.96 g of 4-aminophenylboronic acid pinacol ester were dissolved in 150 ml of a mixed solution of dimethylformamide and water in a volume ratio of 6:1, 4.31 g of sodium carbonate was added, and the mixture was stirred and mixed evenly. The mixture was heated to 150° C. in an argon environment, and 0.05 g of bis(triphenylphosphine)palladium dichloride was added thereto. The mixture was reacted for 15 hours. After the reaction was completed, the pH value of the solution was adjusted to 6.8 using hydrochloric acid. The solvent was removed by distillation under reduced pressure from the obtained reaction solution. The obtained residue was developed using a solvent of dichloromethane and methanol in a volume ratio of 100:1 and purified by column chromatography to obtain 0.91 g of the intermediate diamine product with a yield of 83.71%; wherein 1 H NMR(400MHz, DMSO-d6)δ7.52-7.46(m,4H),7.28(d,J=2.2Hz,2H),7.15(t,J=2.2Hz ,1H),6.72-6.66(m,4H),5.36(s,4H),4.09(q,J=6.7Hz,2H),1.39(t,J=6.7Hz,3H). 13 C NMR (101MHz, DMSO-d6) δ159.01,148.00,141.39,130.40,127.70,123.08,115.07,113.15,63.86,14.58.

[0044] 2) 0.91 g of the intermediate diamine product obtained in step 1) and 0.75 g of 2,6-pyridinedicarboxylic acid were added to 120 ml of dichloromethane, and 2.29 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.62 g of 1-hydroxybenzotriazole were added thereto. The mixture was heated to 60° C. and reacted for 5 h. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The resulting residue was purified by column chromatography using a solvent having a volume ratio of dichloromethane to methanol of 60:1 as a developing solvent, and then recrystallized using a mixed solution of petroleum ether and dichloromethane in a volume ratio of 10:1 to obtain an amide macrocycle for fluoride ion recognition.

[0045] Example 4 1) 1 g of 1,3-dibromo-5-ethoxybenzene and 3.32 g of 4-{4-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]phenyl}aniline were dissolved in 180 ml of a mixed solution of dioxane and water in a volume ratio of 8:1, 2.96 g of potassium carbonate was added, and the mixture was stirred and mixed uniformly. The mixture was heated to 120° C. in an argon environment, and 0.04 g of tetrakis(triphenylphosphine)palladium was added thereto. The mixture was reacted for 10 hours. After the reaction was completed, the pH value of the solution was adjusted to 7 with hydrochloric acid, and the solvent was removed by distillation under reduced pressure from the obtained reaction solution. The obtained residue was purified by column chromatography using a solvent in a volume ratio of dichloromethane and methanol in a ratio of 60:1 as a developing solvent to obtain 1.72 g of an intermediate diamine product with a yield of 79.17%; wherein 1 H NMR (400MHz, DMSO-d6) δ7.78-7.74(m,4H),7.70(t,J=2.1Hz,1H),7.68-7.64(m,12H),7.51-7.47(m,4H ), 7.30 (d, J = 2.2Hz, 2H), 6.72-6.67 (m, 4H), 5.36 (s, 4H), 4.09 (q, J = 6.7Hz, 2H), 1.39 (t, J = 6.7Hz, 3H). 13 C NMR(100MHz,DMSO-d6)δ159.00,148.00,141.58,140.90,140.88,140.87,140.27,135.74,130.43,128 .09,127.97,127.94,127.90,127.86,127.85,127.83,127.66,123.06,115.76,113.15,63.86,14.58.

[0046] 2) 1.72 g of the intermediate diamine product obtained in step 1) and 0.57 g of 2,6-pyridinedicarboxylic acid were added to 150 ml of tetrahydrofuran, and 1.63 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.15 g of 1-hydroxybenzotriazole were added thereto. The mixture was heated to 65° C. and reacted for 4.5 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The residue was purified by column chromatography using a solvent having a volume ratio of 50:1 of dichloromethane and methanol as a developing solvent, and then recrystallized using a mixed solution of petroleum ether and dichloromethane having a volume ratio of 10:1 to obtain an amide macrocycle for fluoride ion recognition.

[0047] Example 5 1) 1 g of 1,3-dibromo-5-octyloxybenzene and 1.20 g of 4-aminophenylboronic acid pinacol ester were dissolved in 150 ml of a mixed solution of dioxane and water in a volume ratio of 5:1, 2.27 g of potassium carbonate was added, and the mixture was stirred and mixed evenly. The mixture was heated to 140° C. in an argon environment, and 0.06 g of tetrakis(triphenylphosphine)palladium was added thereto. The mixture was reacted for 20 hours. After the reaction was completed, the pH value of the solution was adjusted to 6.7 with hydrochloric acid, and the solvent was removed by distillation under reduced pressure from the obtained reaction solution. The obtained residue was purified by column chromatography using a solvent with a volume ratio of dichloromethane and methanol of 80:1 as a developing solvent to obtain 0.89 g of the intermediate diamine product with a yield of 83.40%; wherein 1 H NMR (400MHz, DMSO-d6) δ7.52-7.47(m,4H),7.24(d,J=2.2Hz,2H),7.15(t,J=2.2Hz,2H),6.69(d,J=8.3Hz,4H),5.36(s,4H),4.02(t, J=6.3Hz,2H),1.75(t,J=7.4,6.4Hz,2H),1.48-1.39(m,2H),1.32-1.31(m,2H),1.29(s,2H),1.29(s,2H),1.28(s,2H),0.89(s,3H). 13 C NMR(100MHz,DMSO-d6)δ160.06,148.00,141.30,130.40,127.70,123.16, 115.07,112.99,68.62,31.72,29.42,29.25,29.20,26.03,22.65,14.05.

[0048] 2) 0.89 g of the intermediate diamine product obtained in step 1) and 0.38 g of 2,6-pyridinedicarboxylic acid were added to 120 ml of tetrahydrofuran, and 1.32 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 0.93 g of 1-hydroxybenzotriazole were added thereto. The mixture was heated to 75° C. and reacted for 4 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The resulting residue was purified by column chromatography using a solvent having a volume ratio of 50:1 of dichloromethane and methanol as a developing solvent, and then recrystallized using a mixed solution of petroleum ether and dichloromethane having a volume ratio of 10:1 to obtain an amide macrocycle for fluoride ion recognition.

[0049] Example 6 1) 1 g of 1,3-dibromo-5-octyloxybenzene and 2.03 g of 4-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]aniline were dissolved in 180 ml of a mixed solution of dioxane and water in a volume ratio of 5:1, 3.32 g of sodium carbonate was added, and the mixture was stirred and mixed uniformly. The mixture was heated to 100° C. in an argon environment, and 0.04 g of bis(triphenylphosphine)palladium dichloride was added thereto. The mixture was reacted for 24 hours. After the reaction was completed, the pH value of the solution was adjusted to 6.5 with hydrochloric acid, and the solvent was removed by distillation under reduced pressure from the obtained reaction solution. The obtained residue was purified by column chromatography using a solvent with a volume ratio of dichloromethane and methanol of 70:1 as a developing solvent to obtain 1.27 g of the intermediate diamine product with a yield of 85.52%; wherein 1 H NMR(400MHz,DMSO-d6)δ7.78-7.74(m,4H),7.70(t,J=2.1Hz,1H),7.68-7.64 (m,4H),7.51-7.47(m,4H),7.27(d,J=2.2Hz,2H),6.72-6.67(m,4H),5.36(s, 4H),4.02(t,J=6.3Hz,2H),1.79-1.71(m,2H),1.44(m,J=7.7,6.7Hz,2H),1.3 2(d,J=0.7Hz,2H),1.30(s,2H),1.29-1.28(m,2H),1.27(s,2H),0.89(s,3H). 13 CNMR(100MHz,DMSO-d6)δ160.04,148.00,141.48,140.28,135.74,130.43,128.09,127.85 ,127.66,123.14,115.77,112.99,68.62,31.72,29.42,29.25,29.20,26.03,22.65,14.05.

[0050] 2) 1.27 g of the intermediate diamine product obtained in step 1) and 0.47 g of 2,6-pyridinedicarboxylic acid were added to 150 ml of tetrahydrofuran, and 1.80 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.27 g of 1-hydroxybenzotriazole were added thereto. The mixture was heated to 65° C. and reacted for 5 h. After the reaction was completed, the solvent was removed by distillation under reduced pressure. The resulting residue was purified by column chromatography using a solvent having a volume ratio of 50:1 of dichloromethane and methanol as a developing solvent, and then recrystallized using a mixed solution of petroleum ether and dichloromethane having a volume ratio of 10:1 to obtain an amide macrocycle for fluoride ion recognition.

[0051] Performance Testing

[0052] The amide macrocycle for fluoride ion recognition prepared in Example 1 was subjected to anion recognition experiment. The specific experimental method is as follows: the amide macrocycle for fluoride ion recognition prepared in Example 1 was used to recognize different halogen ions, bisulfate ions, and trifluoromethanesulfonate ions, wherein the halogen ions were provided by tetraethylammonium fluoride, tetraethylammonium chloride, tetraethylammonium bromide, and tetraethylammonium iodide, respectively; the bisulfate ion was provided by tetraethylammonium bisulfate; and the trifluoromethanesulfonate ion was provided by tetraethylammonium trifluoromethanesulfonate. The amide macrocycle for fluoride ion recognition was prepared with deuterated dimethyl sulfoxide to a concentration of 2.97×10 -2 M solution, 5 equivalents of anions were added thereto, and the obtained solution was subjected to nuclear magnetic resonance testing by hydrogen nuclear magnetic resonance spectrometer. The detection spectrum is as follows Figure 5 As shown. Figure 5 The results show that after the addition of different anions to the amide macrocycle used for fluoride ion recognition, only the addition of fluoride ions causes significant changes in the nuclear magnetic resonance hydrogen spectrum of the amide macrocycle used for fluoride ion recognition, with a huge chemical shift of the amide hydrogen and an obvious chemical shift of the hydrogen in the aromatic region; the addition of other ions does not cause significant changes in the hydrogen spectrum, indicating that the amide macrocycle used for fluoride ion recognition only forms a very strong recognition effect with fluoride ions.

[0053] The amide macrocycle for fluoride ion recognition prepared in Example 1 of the present invention was found to have a sharp color change from colorless to yellow after tetraethylammonium fluoride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, tetraethylammonium hydrogen sulfate and tetraethylammonium trifluoromethanesulfonate were added to the dimethyl sulfoxide solution of the amide macrocycle for fluoride ion recognition. The results are as follows: Figure 6 As shown in Figure 4, the addition of several other anions did not result in any noticeable color change. This distinct color change also reflects the highly selective recognition of fluoride ions by the amide macrocycle used for fluoride ion recognition, making it a useful tool for the rapid detection and identification of fluoride.

[0054] In order to further study the color change phenomenon after adding fluoride ions, the dimethyl sulfoxide solution of the amide macrocycle for fluoride ion recognition prepared in Example 1 of the present invention was subjected to UV-visible spectrophotometry. -4 M), 5 equivalents of various anions were added, and the resulting solution was subjected to UV-visible absorption test. The UV-visible absorption spectrum was as shown in FIG. Figure 7 As shown. Figure 7 It can be seen that all anions lead to an increase in the absorption intensity in the visible light band. However, after the addition of fluoride ions, the UV-visible absorption spectrum of the amide macrocycle used for fluoride ion recognition not only increases in absorbance, but also shows an obvious red shift and forms a new shoulder peak. Combined with the changes in the chemical shifts of the amide group and aromatic region peaks in the nuclear magnetic resonance hydrogen spectrum after the addition of fluoride ions, it further indicates that the amide macrocycle used for fluoride ion recognition forms a stable complex with fluoride ions in dimethyl sulfoxide solution.

[0055] The above results show that the amide macrocycle for fluoride ion recognition prepared by the present invention has a strong binding force with fluoride anions and is highly selective. The complexation can be detected by the naked eye with a clear color change. At the same time, the amide macrocycle for fluoride ion recognition can form a 1:3 complex with fluoride ions, with a binding constant of up to 10 4 M -1 Therefore, the characteristics of the amide macrocycle for fluoride ion recognition of the present invention in binding to fluoride anions (strong, selective, and detectable without instruments) will provide a basis for various applications in the field of fluoride detection and removal of fluorine-containing pollutants.

[0056] Although the above describes the specific implementation methods of the present invention, it does not limit the scope of protection of the present invention. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. An amide macrocycle for fluoride ion recognition, characterized in that: Its structural formula is as follows: Wherein R is a C1-C16 alkane group, and n = 1.

2. The method for preparing an amide macrocycle for fluoride ion recognition according to claim 1, wherein: The following steps are involved: 1) Compound 1 and Compound 2 are dissolved in an organic solvent, water and a base are added, the mixture is stirred and mixed uniformly, and the mixture is heated to 80-150°C in an argon atmosphere. A catalyst is then added and the mixture is reacted for 10-24 hours. After the reaction is completed, the pH value of the solution is adjusted to 6.5-7 with hydrochloric acid. The solvent is removed by vacuum distillation of the resulting reaction solution. The resulting residue is purified by column chromatography using a solvent having a volume ratio of dichloromethane to methanol of 50-100:1 as a developing solvent to obtain an intermediate diamine product; The structural formula of the compound 1 is , wherein R is a C1-C16 alkane group; The structural formula of compound 2 is , where n = 1; 2) The intermediate diamine product prepared in step 1) and 2,6-pyridinedicarboxylic acid are added to organic solvent 2, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole are added thereto. The mixture is heated to 55-80° C. and reacted for 4-5 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure. The resulting residue is purified by column chromatography using a solvent having a volume ratio of dichloromethane to methanol of 40-60:1 as a developing solvent, and then recrystallized to obtain an amide macrocycle for fluoride ion recognition.

3. The method for preparing an amide macrocycle for fluoride ion recognition according to claim 2, wherein: The organic solvent in step 1) is dioxane or dimethylformamide; the base in step 1) is potassium carbonate or sodium carbonate; the catalyst in step 1) is tetrakis(triphenylphosphine)palladium or bis(triphenylphosphine)palladium dichloride.

4. The method for preparing an amide macrocycle for fluoride ion recognition according to claim 2, wherein: The volume ratio of the organic solvent to water in step 1) is 4-8:

1.

5. The method for preparing an amide macrocycle for fluoride ion recognition according to claim 2, wherein: In step 1), the molar ratio of compound 1, compound 2, base and catalyst is 1:2-2.5:5-8:0.01-0.

02.

6. The method for preparing an amide macrocycle for fluoride ion recognition according to claim 2, wherein: The organic solvent 2 in step 2) is tetrahydrofuran or dichloromethane; the molar ratio of 2,6-pyridinedicarboxylic acid, the intermediate diamine product, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole in step 2) is 1:1~1.5:2~4:2~4.

7. The method for preparing an amide macrocycle for fluoride ion recognition according to claim 2, wherein: The solvent used for the recrystallization in step 2) is a mixed solution of petroleum ether and dichloromethane in a volume ratio of 10:

1.

8. The preparation method of the amide macrocycle for fluoride ion identification as claimed in claim 2, wherein The feature is that: the compound 1 in step 1) is ; The compound 2 is ; The organic solvent is dioxane; the base is potassium carbonate; the catalyst is tetrakis(triphenylphosphine)palladium; the molar ratio of compound 1, compound 2, base and catalyst is 1:2:6:0.01; the volume ratio of the organic solvent and water in step 1) is 5:

1.

9. The method for preparing an amide macrocycle for fluoride ion recognition according to claim 2, wherein: In step 2), the organic solvent 2 is tetrahydrofuran; the heating temperature is 65° C.; the molar ratio of the 2,6-pyridinedicarboxylic acid, the intermediate diamine product, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole is 1:1:3:

3.

10. Use of the amide macrocycle for fluoride ion recognition according to claim 1 in the preparation of reagents for the detection of fluoride and the removal of fluorine-containing pollutants.

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