A 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 and a synthesis method thereof

Abstract

This invention relates to a 4-(pyridine-2-methyleneamino)benzoic acid-functionalized NU-1000 and its synthesis method. 4-(pyridine-2-methyleneamino)benzoic acid is introduced through coordination of its carboxyl group with the NU-1000 node cluster. This invention is mainly used for the preparation of organic ligand-functionalized NU-1000. It solves the problem of fluorescence recognition detection of Al in the prior art. 3+ The high cost and poor stability of MOF synthesis.

Description

Technical Field

[0001] The invention belongs to the field of functional complex material preparation, and specifically relates to 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 and a synthesis method thereof. Background Art

[0002] As we all know, Al is the most abundant metal element in the earth's crust. It is widely present in cooking utensils, cans, food additives, water treatment agents, grain protection agents, etc. in our daily lives. It can enter the human body through drinking water and food and accumulate. 3+ It is not an essential trace element for the human body. When the content in the body is too high, the nervous system, bones, etc. will be affected, and further develop into diseases such as Alzheimer's disease, senile dementia, osteoporosis, non-iron deficiency anemia, etc., which seriously affect the health and quality of life of the human body. According to the World Health Organization, the daily intake of Al 3+ The intake should be less than 4 mg. 3+ In order to understand the harm that an imbalance in aluminum content can cause to human health, it is necessary to conduct highly selective and sensitive detection of the aluminum content in the environment and organisms.

[0003] Currently, a variety of methods have been developed to 3+ There are many methods for the detection of Al, such as atomic absorption spectroscopy, electrochemical method, inductively coupled plasma method, fluorescence sensing method, etc. Among them, fluorescence sensing method has attracted much attention due to its real-time monitoring, simple operation, less time consumption, low cost, and high sensitivity. Metal-organic frameworks (MOFs) are one of the commonly used materials for the preparation of fluorescent sensors, which have the characteristics of simple synthesis, rich structure, high porosity, large specific surface area, and uniform distribution of action sites. However, the currently reported methods for the fluorescent recognition and detection of Al 3+ Most MOFs are lanthanide MOFs with high cost and scarcity or transition metal-based MOFs with poor stability, while zirconium-based MOFs with low cost and good stability are less studied, and most of the research focuses on the selection and modification of their ligands, which limits their wide application in practical detection. Summary of the invention

[0004] Based on the problems existing in the background technology, the present invention provides a 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 and a synthesis method thereof, which solves the problem of fluorescent recognition and detection of Al 3+ The MOFs have the problems of high synthesis cost and poor stability.

[0005] The technical solution provided by the present invention is as follows:

[0006] A 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000, characterized in that 4-(pyridine-2-methyleneamino)benzoic acid is introduced through the coordination of carboxyl groups with the NU-1000 node cluster.

[0007] Furthermore, the infrared spectrum data of the 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 are 1176 (m), 1143 (w), 1095 (m), 1004 (w), 979 (w), 862 (w), 838 (w), 783 (s), 715 (m), 657 (s), 567 (w), 467 (s).

[0008] Furthermore, the 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 can be applied to Al 3+ Fluorescence identification.

[0009] A method for synthesizing NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid, characterized in that it comprises the following steps:

[0010] S1: Synthetic NU-1000

[0011] 10 mg ZrCl4, 386 mg benzoic acid and 1.2 mL DMF were weighed in a 15 mL polytetrafluoroethylene high temperature and high pressure reactor, stirred for 10 min, placed in an oven at 80 ° C for 1 h, cooled to room temperature, and then 6 mg 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene was added, stirred for 10 min, placed in an oven at 120 ° C for 3 days, cooled to room temperature and centrifuged to obtain yellow powder NU-1000;

[0012] S2: Activation of NU-1000

[0013] The NU-1000 synthesized by S1 was immersed in a mixed solution consisting of DMF and HCl, and then stirred at room temperature, filtered, and dried to obtain a solid, which was the activated NU-1000;

[0014] S3: Synthesis of 4-(pyridine-2-methyleneamino)benzoic acid

[0015] In a 25 mL round-bottom flask, 684 mg of p-aminobenzoic acid, 642 mg of 2-pyridinecarboxaldehyde and 10 mL of EtOH were weighed, and then stirred and refluxed at 80 °C for 3 h. After cooling to room temperature, the mixture was filtered, washed with 3×15 mL of EtOH, and dried to obtain a light yellow powdery solid, which is 4-(pyridine-2-methyleneamino)benzoic acid;

[0016] S4: Synthesis of NU-1000 functionalized with 4-(pyridin-2-methyleneamino)benzoic acid

[0017] NU-1000 activated by S2 and 4-(pyridine-2-methyleneamino)benzoic acid synthesized by S3 were mixed in DMF, with an excess of 4-(pyridine-2-methyleneamino)benzoic acid. The mixture was then heated and stirred, cooled to room temperature, filtered, and washed to obtain a light yellow powdery solid, which was NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) A Zr-based NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid was successfully synthesized by a simple solvent-assisted ligand incorporation method, in which 4-(pyridine-2-methyleneamino)benzoic acid was introduced by coordinating with the NU-1000 node cluster. Compared with NU-1000, NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid had a better affinity for Al 3+ It showed more sensitive fluorescence enhanced recognition performance, with Ksv of 1.0×10 3 M -1 , LOD is 1.29×10 -5 M.

[0020] (2) 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 for Al 3+ The fluorescence identification of Al2O3 has strong anti-interference ability and can be used for more than 4 rounds, which has potential application value in the fluorescence identification of harmful metal ions. 3+ Synthetic strategy of Zr-based MOFs with fluorescence recognition. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. It is obvious that the drawings described below are only one or more embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid and its PXRD pattern;

[0023] Figure 2 The 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 of the present invention and the N2 adsorption-desorption diagram and pore size distribution diagram of NU-1000;

[0024] Figure 3 The performance of the 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 of the present invention in fluorescent recognition of different metal ions;

[0025] Figure 4 The NU-1000 fluorescent recognition Al 3+ Selective graphs;

[0026] Figure 5 The NU-1000 fluorescent recognition Al 3+ Sensitivity diagram of

[0027] Figure 6 The NU-1000 fluorescent recognition Al 3+ Recyclability diagram of

[0028] Figure 7 The 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 and the NU-1000 fluorescent recognition Al 3+ Performance comparison chart. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0030] Reference Figure 1-7 NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid and its synthesis method and its application to Al 3+ The fluorescence identification includes the following steps:

[0031] 1. Preparation of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid

[0032] Example 1

[0033] 1.1 Preparation of NU-1000: 10 mg ZrCl4, 386 mg benzoic acid and 1.2 mL DMF were weighed in a 15 mL polytetrafluoroethylene high temperature and high pressure reactor, stirred for 10 min, and then placed in an oven at 80 ° C for 1 h, cooled to room temperature, and then 6 mg 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene (TBApy) was added, stirred for 10 min, and then placed in an oven at 120 ° C for 3 days. After cooling to room temperature, centrifugation was performed to obtain yellow powder NU-1000;

[0034] 1.2 Activation of NU-1000: 80 mg of NU-1000 synthesized in 1.1 was soaked in 25 mL of a mixed solution consisting of DMF and 8 mol / L HCl (the volume ratio of DMF to HCl was 24:1), then stirred at room temperature for 24 h, filtered, and dried to obtain a yellow powdery solid, which was the activated NU-1000;

[0035] 1.3 Preparation of 4-(pyridine-2-methyleneamino)benzoic acid: In a 25 mL round-bottom flask, weigh (5 mmol, 684 mg) p-aminobenzoic acid, (6 mmol, 642 mg) 2-pyridinecarboxaldehyde and 10 mL EtOH, then stir and reflux at 80 ° C for 3 h, cool to room temperature and filter, wash with 3×15 mL of EtOH, and dry at room temperature to obtain a light yellow powdery solid, which is 4-(pyridine-2-methyleneamino)benzoic acid;

[0036] 1.4 Preparation of 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000: Mix 0.015 mmol NU-1000 activated in 1.2 and 0.15 mmol 4-(pyridine-2-methyleneamino)benzoic acid synthesized in 1.3 in 10 mL DMF, then stir at 63°C and 300 rpm for 2 days. After cooling, filter and wash to obtain 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000.

[0037] 2.4-(pyridin-2-methyleneamino)benzoic acid functionalized NU-1000 for Al 3+ Fluorescence recognition

[0038] Example 2

[0039] 2 mg of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid obtained in Example 1 was taken, ground, and dispersed in 10 mL of methanol. Then 3 mL of the suspension was taken out and 10 uL of 100 mM Al was added. 3+ A methanol solution was prepared and ultrasonically treated, and then the fluorescence spectrum of the suspension was measured at room temperature. The fluorescence intensity was 1.85 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0040] Example 3

[0041] In implementation case 2, the added Al 3+ The solution was treated with an equal amount of Mg 2+ The solution was replaced, and the other steps were the same as in Example 1. The fluorescence intensity was detected by fluorescence spectrum, which was 0.93 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0042] Example 4

[0043] In implementation case 2, the added Al 3+ The solution was treated with an equal amount of Ag + The solution was replaced, and the other steps were the same as in Example 1. The fluorescence intensity was detected by fluorescence spectrum, which was 0.36 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0044] Example 5

[0045] In implementation case 2, the added Al 3+ The solution was treated with an equal amount of Ca 2+ The solution was replaced, and the other steps were the same as in Example 1. The fluorescence intensity was detected by fluorescence spectrum, which was 1.04 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0046] Example 6

[0047] In implementation case 2, the added Al 3+ The solution was treated with an equal amount of Zn 2+ The solution was replaced, and the other steps were the same as those in Example 1. The fluorescence intensity was detected by fluorescence spectroscopy and was 0.82 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0048] Example 7

[0049] In implementation case 2, the added Al 3+ The solution was treated with an equal amount of Cu 2+ The solution was replaced, and the other steps were the same as in Example 1. The fluorescence intensity was detected by fluorescence spectrum, which was 0.30 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0050] Example 8

[0051] In implementation case 2, the added Al 3+ The solution was treated with an equal amount of Cd 2+ The solution was replaced, and the other steps were the same as those in Example 1. The fluorescence intensity was detected by fluorescence spectroscopy and was 0.76 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0052] Example 9

[0053] In implementation case 2, the added Al 3+ The solution was treated with an equal amount of Ni 2+The solution was replaced, and the other steps were the same as those in Example 1. The fluorescence intensity was detected by fluorescence spectroscopy and was 0.68 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0054] Example 10

[0055] In implementation case 2, the added Al 3+ The solution was treated with an equal amount of Mn 2+ The solution was replaced, and the other steps were the same as in Example 1. The fluorescence intensity was detected by fluorescence spectrum, which was 0.95 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0056] Embodiment 11

[0057] In implementation case 2, the added Al 3+ The solution was treated with an equal amount of Cr 3+ The solution was replaced, and the other steps were the same as in Example 1. The fluorescence intensity was detected by fluorescence spectrum, which was 0.96 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0058] Example 12

[0059] In implementation case 2, the added Al 3+ The solution was treated with an equal amount of Co 2+ The solution was replaced, and the other steps were the same as in Example 1. The fluorescence intensity was detected by fluorescence spectrum, which was 1.12 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0060] 3.4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 fluorescence recognition of Al 3+ Selectivity

[0061] Embodiment 13

[0062] Take 2 mg of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid prepared in Example 1, grind it, disperse it in 10 mL of methanol, take out 3 mL, add 100 uL of 100 mM Al 3+ of methanol solution and 100uL of 100mM Ag + The suspension was then ultrasonically treated with a methanol solution and the fluorescence spectrum was measured at room temperature. The fluorescence intensity was 1.71 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0063] Embodiment 14

[0064] In implementation case 13, the added Ag+ The solution was treated with an equal amount of Cu 2+ The solution was replaced, and the other steps were the same as in Example 13. The fluorescence intensity was detected by fluorescence spectroscopy and was 1.62 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0065] Embodiment 15

[0066] In implementation case 13, the added Ag + The solution was treated with an equal amount of Co 2+ The solution was replaced, and the other steps were the same as in Example 13. The fluorescence intensity was detected by fluorescence spectroscopy and was 1.62 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0067] Example 16

[0068] In implementation case 13, the added Ag + The solution was treated with an equal amount of Mg 2+ The solution was replaced, and the other steps were the same as in Example 13. The fluorescence intensity was detected by fluorescence spectroscopy and was 1.84 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0069] Embodiment 17

[0070] In implementation case 13, the added Ag + The solution was treated with an equal amount of Cr 3+ The solution was replaced, and the other steps were the same as in Example 13. The fluorescence intensity was detected by fluorescence spectroscopy and was 1.65 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0071] Embodiment 18

[0072] In implementation case 13, the added Ag + The solution was treated with an equal amount of Ca 2+ The solution was replaced, and the other steps were the same as those in Example 13. The fluorescence intensity was detected by fluorescence spectroscopy and was 1.89 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0073] Embodiment 19

[0074] In implementation case 13, the added Ag + The solution was treated with an equal amount of Ni 2+ The solution was replaced, and the other steps were the same as in Example 13. The fluorescence intensity was detected by fluorescence spectroscopy and was 1.67 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0075] Embodiment 20

[0076] In implementation case 13, the added Ag + The solution was treated with an equal amount of Zn 2+ The solution was replaced, and the other steps were the same as in Example 13. The fluorescence intensity was detected by fluorescence spectroscopy and was 1.91 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0077] Embodiment 21

[0078] In implementation case 13, the added Ag + The solution was treated with an equal amount of Mn 2+ The solution was replaced, and the other steps were the same as in Example 13. The fluorescence intensity was detected by fluorescence spectroscopy and was 1.68 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0079] 4.4-(Pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 for fluorescence recognition of Al 3+ The cyclical nature

[0080] Embodiment 22

[0081] 50 mg of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid obtained in Example 1 was taken, ground, and dispersed in 5 mL of 1 mM Al 3+ The solid was placed in a methanol solution and centrifuged and dried after 10 minutes. The fluorescence spectrum of the solid was measured at room temperature. The test results showed that its fluorescence intensity was 1.9 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

[0082] Embodiment 23

[0083] The solid in Example 22 was repeatedly washed with ethanol for 5 times, then dried, and its fluorescence spectrum was measured at room temperature; the solid was added to 5 mL of 1 mM Al 3+ The solid was placed in a methanol solution and centrifuged after 10 minutes. The fluorescence spectrum of the solid was measured again at room temperature. The test results showed that the fluorescence intensities of the two tests were 0.9 times and 1.98 times that of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid, respectively.

[0084] Embodiment 24

[0085] The operation of Example 23 was repeated, and the results showed that the fluorescence intensities of the two tests were 0.91 times and 2.1 times the fluorescence intensity of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid, respectively.

[0086] Embodiment 25

[0087] The operation of Example 24 was repeated, and the results showed that the fluorescence intensities of the two tests were 0.87 times and 2.2 times the fluorescence intensity of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid, respectively.

[0088] 5.4-(Pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 and NU-1000 fluorescence recognition of Al 3+ Comparison

[0089] Embodiment 26

[0090] 2 mg of NU-1000 and 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 obtained in Example 1 were ground and dispersed in 10 mL of methanol, respectively. Then 3 mL of the suspension was taken out and 10 uL of 100 mM Al was added to each suspension. 3+ The fluorescence spectra of the two suspensions were measured at room temperature after ultrasonic treatment. 3+ The fluorescence intensity of NU-1000 was 1.3 times that of NU-1000 suspension. 3+ The fluorescence intensity of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid is 1.78 times that of the suspension of NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid, indicating that NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid has a strong affinity for Al 3+ The recognition effect is better.

[0091] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000, characterized in that: 4-(Pyridine-2-methyleneamino)benzoic acid was introduced via coordination of the carboxyl group to the NU-1000 node cluster.

2. The 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 according to claim 1, characterized in that: Its infrared spectrum data are 1656(s),1601(s),1539(m),1413(s),1249(w),1176(m),1143(w),1095(m),1004(w),979(w),862(w),838(w),783(s),715(m),657(s),567(w),467(s).

3. The 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000 according to claim 1, characterized in that: Can be used for Al 3+ Fluorescence identification.

4. A method for synthesizing 4-(pyridine-2-methyleneamino)benzoic acid functionalized NU-1000, characterized in that: The following steps are involved: S1: Synthetic NU-1000 10 mg ZrCl4, 386 mg benzoic acid and 1.2 mL DMF were weighed in a 15 mL polytetrafluoroethylene high temperature and high pressure reactor, stirred for 10 min, placed in an oven at 80 ° C for 1 h, cooled to room temperature, and then 6 mg 1,3,6,8-tetrakis (4-carboxyphenyl) pyrene was added, stirred for 10 min, placed in an oven at 120 ° C for 3 days, cooled to room temperature and centrifuged to obtain yellow powder NU-1000; S2: Activation of NU-1000 The NU-1000 synthesized by S1 was immersed in a mixed solution of DMF and HCl, and then stirred at room temperature, filtered, and dried to obtain a solid, which was the activated NU-1000; S3: Synthesis of 4-(pyridine-2-methyleneamino)benzoic acid In a 25 mL round-bottom flask, 684 mg of p-aminobenzoic acid, 642 mg of 2-pyridinecarboxaldehyde and 10 mL of EtOH were weighed, and then stirred and refluxed at 80 ° C for 3 h. After cooling to room temperature, the mixture was filtered, washed with 3×15 mL of EtOH, and dried to obtain a light yellow powdery solid, which is 4-(pyridine-2-methyleneamino)benzoic acid; S4: Synthesis of NU-1000 functionalized with 4-(pyridin-2-methyleneamino)benzoic acid NU-1000 activated by S2 and 4-(pyridine-2-methyleneamino)benzoic acid synthesized by S3 were mixed in DMF, with an excess of 4-(pyridine-2-methyleneamino)benzoic acid. The mixture was then heated and stirred, cooled to room temperature, filtered, and washed to obtain a light yellow powdery solid, which was NU-1000 functionalized with 4-(pyridine-2-methyleneamino)benzoic acid.

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