Amide macrocycle for fluorine ion recognition as well as preparation method and application of amide macrocycle

Abstract

The invention discloses an amide macrocyclic compound for fluorine ion recognition and a preparation method and application thereof, and belongs to the technical field of supramolecular chemical macrocyclic subject design and subject-object recognition, a macrocyclic aromatic amide subject is prepared through Suzuki coupling reaction and condensation reaction, and a macrocyclic receptor is mainly composed of three 2, 3-difluoro-2, 3-difluoro-2, 3-difluoro-2, 3-difluoro-2, 3-difluoro-2, 3-difluoro-2, 3-difluoro-2, 3-difluoro-2, 3-difluoro-2, 3- the molecular fragments comprise a 1, 6-pyridine diamide molecular fragment and three biphenyl molecular fragments; the molecules prepared by the method internally contain huge cavities and rich hydrogen bond recognition sites, fluorine ions can be selectively recognized in a solution through hydrogen bond interaction, and the complexing constant on the fluorine ions is as high as 104M <-1 >; the preparation process is simple and convenient, and raw materials are easily available; the method has potential application prospects in the fields of fluoride detection, fluorine-containing pollutant removal and the like.

Description

Technical Field

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

[0002] Anions play well-known roles in our daily lives. Among the numerous anions of great biological significance, fluorine is the smallest anion present in the natural environment, and it is essential for the healthy development of teeth and the normal functioning of various body organs. In addition to biological functions, various modern high-tech technologies and industrial products require fluoride as a necessary chemical processing reagent, such as the engraving of quartz glass, the recovery of precious metals, the production of fertilizers and semiconductor materials, etc. Therefore, the industrial wastewater, solid waste and waste gas generated by these industries inevitably contain a lot of fluoride or hydrofluoric acid, which leads to serious pollution of the environment by fluoride. Therefore, how to avoid the pollution of the environment and the harm of the body by fluoride while applying fluoride has been an important research topic for many years.

[0003] In recent years, it has been 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 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, as a molecular fragment of an effective anion receptor, forms a "V"-shaped semi-enclosed region that 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 host synthesized in the prior art often shows similar affinity for anions other than fluoride ions in anion recognition, and it is difficult to highly selectively recognize fluoride ions in highly polar solutions. Summary of the invention

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

[0005] In order to achieve the above object, 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 evenly, and the mixture is heated to 80-150° C. in an argon environment, and a catalyst is 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, and the obtained reaction solution is subjected to reduced pressure distillation to remove the solvent, and the obtained residue is subjected to column chromatography purification 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 the compound 2 is Where n = 1 to 3;

[0013] 2) The intermediate diamine product obtained 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. for reaction for 4-5 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and the 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] In step 1), the base 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] 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.

[0020] In step 2), the organic solvent 2 is tetrahydrofuran or dichloromethane.

[0021] In step 2), the molar ratio of 2,6-pyridinedicarboxylic acid, intermediate diamine product, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1-hydroxybenzotriazole is 1:1-1.5:2-4:2-4.

[0022] 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.

[0023] 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.

[0024] Preferably, in step 2), the organic solvent 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.

[0025] 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.

[0026] The synthetic route of the amide macrocycle for fluoride ion recognition of the present invention is:

[0027]

[0028] Wherein R is a C1-C16 alkane group, and n=1-3.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] 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 by 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 to various anions such as halogen, hydrogen sulfate, trifluoromethanesulfonate, etc., it is 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 by the naked eye is attributed to the fact that the amide macrocycle for fluoride ion recognition has a huge cavity and contains abundant hydrogen bond recognition sites, and forms multiple hydrogen bond interactions with fluoride ions in the solution.

[0031] 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 huge spatial size, which is conducive to accommodating more anionic guests and 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 recognition, fluoride detection and removal of fluorine-containing pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the intermediate diamine product prepared in Example 1 of the present invention;

[0033] Figure 2 This is a high-resolution mass spectrum of the intermediate diamine product prepared in Example 1 of the present invention;

[0034] 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;

[0035] 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;

[0036] Figure 5 The nuclear magnetic resonance hydrogen 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, hydrogen sulfate and triflate respectively in deuterated dimethyl sulfoxide (DMSO-d6);

[0037] 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;

[0038] 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, hydrogen sulfate and trifluoromethanesulfonate in dimethyl sulfoxide. DETAILED DESCRIPTION

[0039] In order to better understand the technical solution of the present invention, the above content of the present invention is further described in detail below through specific implementation methods in the form of embodiments, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples. All technologies realized based on the above content of the present invention belong to the scope of the present invention.

[0040] Example 1 1) 1.50 g of 1,3-dibromo-5-methoxybenzene and 2.47 g of 4-aminophenylboronic acid pinacol ester 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, the mixture was stirred and mixed evenly, and the mixture was heated to 100°C in an argon environment. 0.13 g of tetrakis(triphenylphosphine)palladium was added thereto, and the reaction was carried out for 12 hours. After the reaction was completed, the pH value of the solution was adjusted to 7 with hydrochloric acid, and the obtained reaction solution was distilled under reduced pressure to remove the solvent. The obtained residue was purified by column chromatography using a solvent in a volume ratio of 80:1 of dichloromethane and methanol as a developing solvent 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 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.

[0041] 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 reaction for 5 hours. After the reaction was completed, the solvent was removed by vacuum distillation, and the obtained residue was purified by column chromatography using a solvent having a volume ratio of 50:1 of dichloromethane and methanol as a developing agent, 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. The obtained amide macrocycle for fluoride ion recognition was characterized by nuclear magnetic resonance and high-resolution mass spectrometry, and its detection spectrum is 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.

[0042] 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 obtained reaction solution was distilled under reduced pressure to remove the solvent. The obtained residue was purified by column chromatography using a solvent in a volume ratio of 50:1 of dichloromethane and methanol as a developing solvent 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, wherein 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.

[0043] 2) 1.78 g of the intermediate diamine product obtained in step 1) and 0.50 g of 2,6-pyridinedicarboxylic acid are added to 150 ml of tetrahydrofuran, and then 2.29 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.62 g of 1-hydroxybenzotriazole are added thereto, and the mixture is heated to 80° C. and reacted for 5 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and the obtained residue is 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 in a volume ratio of 10:1 to obtain an amide macrocycle for fluoride ion recognition.

[0044] 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, the mixture was stirred and mixed evenly, and heated to 150°C in an argon environment. 0.05 g of di(triphenylphosphine)palladium dichloride was added thereto, and the reaction was carried out for 15 hours. After the reaction was completed, the pH value of the solution was adjusted to 6.8 with hydrochloric acid, and the obtained reaction solution was distilled under reduced pressure to remove the solvent. The obtained residue was purified by column chromatography using a solvent in a volume ratio of dichloromethane and methanol of 100:1 as a developing solvent to obtain 0.91 g of an 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.

[0045] 2) 0.91 g of the intermediate diamine product obtained in step 1) and 0.75 g of 2,6-pyridinedicarboxylic acid are added to 120 ml of dichloromethane, and then 2.29 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.62 g of 1-hydroxybenzotriazole are added thereto, and the mixture is heated to 60° C. and reacted for 5 hours. After the reaction is completed, the solvent is removed by reduced pressure distillation, and the obtained residue is purified by column chromatography using a solvent having a volume ratio of dichloromethane and 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.

[0046] 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 evenly. 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 h. After the reaction was completed, the pH value of the solution was adjusted to 7 with hydrochloric acid, and the obtained reaction solution was distilled under reduced pressure to remove the solvent. The obtained residue was purified by column chromatography using a solvent in a volume ratio of 60:1 of dichloromethane and methanol 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.

[0047] 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 then 1.63 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.15 g of 1-hydroxybenzotriazole were added thereto, and 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, and the obtained residue was purified by column chromatography using a solvent having a volume ratio of dichloromethane and methanol of 50:1 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.

[0048] 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, the mixture was stirred and mixed evenly, and heated to 140°C in an argon environment, and 0.06 g of tetrakis(triphenylphosphine)palladium was added thereto, and the reaction was carried out for 20 hours. After the reaction was completed, the pH value of the solution was adjusted to 6.7 with hydrochloric acid, and the obtained reaction solution was distilled under reduced pressure to remove the solvent. The obtained residue was purified by column chromatography using a solvent in a volume ratio of 80:1 of dichloromethane and methanol as a developing solvent to obtain 0.89 g of an 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.

[0049] 2) 0.89 g of the intermediate diamine product obtained in step 1) and 0.38 g of 2,6-pyridinedicarboxylic acid are added to 120 ml of tetrahydrofuran, and then 1.32 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 0.93 g of 1-hydroxybenzotriazole are added thereto, and the mixture is heated to 75° C. and reacted for 4 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and the obtained residue is purified by column chromatography using a solvent having a volume ratio of dichloromethane and methanol of 50:1 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.

[0050] 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 evenly. 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 obtained reaction solution was distilled under reduced pressure to remove the solvent. The obtained residue was purified by column chromatography using a solvent in a volume ratio of 70:1 of dichloromethane and methanol as a developing solvent to obtain 1.27 g of an 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.

[0051] 2) 1.27 g of the intermediate diamine product obtained in step 1) and 0.47 g of 2,6-pyridinedicarboxylic acid are added to 150 ml of tetrahydrofuran, and then 1.80 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.27 g of 1-hydroxybenzotriazole are added thereto, and the mixture is heated to 65° C. and reacted for 5 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and the obtained residue is purified by column chromatography using a solvent having a volume ratio of dichloromethane and methanol of 50:1 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.

[0052] Performance Testing

[0053] The amide macrocycle for fluoride ion recognition prepared in Example 1 was subjected to anion recognition experiment. The specific experimental method is: the amide macrocycle for fluoride ion recognition prepared in Example 1 is used to recognize different halogen ions, hydrogen sulfate ions and trifluoromethanesulfonate ions, wherein the halogen ions are provided by tetraethylammonium fluoride, tetraethylammonium chloride, tetraethylammonium bromide and tetraethylammonium iodide, respectively, the hydrogen sulfate ions are provided by tetraethylammonium hydrogen sulfate, and the trifluoromethanesulfonate ions are provided by tetraethylammonium trifluoromethanesulfonate. The amide macrocycle for fluoride ion recognition is configured 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 a nuclear magnetic resonance hydrogen spectrometer. The detection spectrum is as follows Figure 5 As shown. Figure 5 The results show that after adding different anions to the amide macrocycle used for fluoride ion recognition, only the addition of fluoride ions causes a significant change 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; while the addition of other ions did not cause a significant change in the hydrogen spectrum, indicating that the amide macrocycle used for fluoride ion recognition only forms a very strong recognition effect with fluoride ions.

[0054] In the recognition process of tetraethylammonium fluoride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, tetraethylammonium hydrogen sulfate and tetraethylammonium trifluoromethanesulfonate, the amide macrocycle for fluoride ion recognition prepared in Example 1 of the present invention was found that after adding tetraethylammonium fluoride to the dimethyl sulfoxide solution of the amide macrocycle for fluoride ion recognition, the color can be observed to change sharply from colorless to yellow by naked eyes. The results are as follows Figure 6 As shown; in contrast, the addition of several other anions did not result in any obvious color change. This obvious 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 rapid detection and identification of fluoride.

[0055] 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 experiment. -4 M), 5 equivalents of various anions were added, and then the obtained solution was subjected to UV-visible absorption test. The UV-visible absorption spectrum results are as follows 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 hydrogen nuclear magnetic resonance spectrum after the addition of fluoride ions, it further indicates that the amide macrocycle used for fluoride ion recognition forms a stable complex with the fluoride ion in the dimethyl sulfoxide solution.

[0056] From the above results, it can be seen that the amide macrocycle for fluoride ion recognition prepared by the present invention has a strong binding force with fluoride anions and has high selectivity. The complexation can be detected by naked eyes with obvious color changes. At the same time, 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 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.

[0057] 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=1-3.

2. The method for preparing an amide macrocycle for fluoride ion recognition according to claim 1, characterized in that: 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 evenly, and the mixture is heated to 80-150° C. in an argon environment, and a catalyst is 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, and the obtained reaction solution is subjected to reduced pressure distillation to remove the solvent, and the obtained residue is subjected to column chromatography purification 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 the compound 2 is Where n = 1 to 3; 2) The intermediate diamine product obtained 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. for reaction for 4-5 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and the 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, characterized in that: 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, characterized in that: The volume ratio of the organic solvent to water in step 1) is 4 to 8:

1.

5. The method for preparing an amide macrocycle for fluoride ion recognition according to claim 2, characterized in that: 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, characterized in that: The organic solvent 2 in step 2) is tetrahydrofuran or dichloromethane; 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.

7. The method for preparing an amide macrocycle for fluoride ion recognition according to claim 2, characterized in that: 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 method for preparing an amide macrocycle for fluoride ion recognition according to claim 2, characterized in that: In step 1), the compound 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, characterized in that: 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 host-guest recognition, fluoride detection and removal of fluorine-containing pollutants.

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