Sm-based metal organic complex and its preparation method and application

Abstract

The present invention discloses a Sm-based metal organic complex having the chemical formula {[Sm(C 12 O6N2H 5.5 )(H2O)(HCOO) 0.5 ]·1.5H2O} n The present invention also discloses a preparation method thereof, specifically comprising the following steps: in a sealed glass bottle, uniformly mixing an organic ligand 1-(imidazole-1-yl)-2,4,6-benzenetricarboxylic acid, Sm(NO3)3·6H2O, N,N-dimethylformamide, distilled water, and nitric acid, and reacting the mixture under solvent thermal conditions. The Sm-based metal organic complex of the present invention has good fluorescence properties and can detect the pesticide emamectin benzoate (EmB) with a low detection limit, good selectivity, and high sensitivity. The complex can also be recycled multiple times to maximize economic benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of rare earth complex preparation, and in particular relates to a Sm-based metal organic complex, and also relates to a preparation method and application of the Sm-based metal organic complex. Background Art

[0002] Pesticides can eliminate a large number of insects that harm plant growth, but due to their excellent stability and ability to survive in the environment for long periods of time, they accumulate in plants and humans, causing serious pollution. In recent years, a number of pesticides with excellent insecticide control, minimal harm, and low toxicity have come into the spotlight, such as pyraclostrobin (Pst), pyrimethanil (Pth), imazalil (Ima), emamectin benzoate (EmB), neutrophil (myc), 2,4-epibrassinolide (2,4-epi), triadimefon (Pro), prochloraz (Tdi), and fluazinam (Flu). Emamectin benzoate, also known as emamectin benzoate and emamectin benzoate, is an insecticide and acaricide, also known as emamectin benzoate and emamectin benzoate. It is widely used on fruits, vegetables, field crops, and fruit trees. It is safe and environmentally friendly, with insecticidal activity dozens of times higher than some other pesticides. However, excessive use can accumulate in the human body, causing poisoning and symptoms such as movement disorders, muscle tremors, dilated pupils, and, in severe cases, vomiting. Using too little can result in ineffective insect control. Therefore, developing a rapid, simple, and low-cost method for detecting Emamectin benzoate is crucial.

[0003] Rare earth organic frameworks (LMOFs) have become a hot topic of research due to their strong luminescence and large Stokes shifts. As excellent sensors, LMOFs possess strong sensing capabilities in a wide range of fields, such as explosives, pesticides, anions and cations, amino acids, and temperature. Tb-MOFs and Eu-MOFs, in particular, emit green and red light under ultraviolet light. Furthermore, Sm-MOFs, due to their strong UV absorption, exhibit excellent properties in photocatalytic degradation and fluorescence detection. Summary of the Invention

[0004] The present invention aims to provide an Sm-based metal organic complex having good fluorescence properties, a lower detection limit and a higher sensitivity in pesticide detection.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned Sm-based metal organic complex.

[0006] The third object of the present invention is to provide the use of the above-mentioned Sm-based metal organic complex in the detection of the pesticide emamectin benzoate.

[0007] The technical solution adopted by the present invention is that the Sm-based metal organic complex has the chemical formula {[Sm(C 12O6N2H 5.5 )(H2O)(HCOO) 0.5 ]·1.5H2O} n .

[0008] The crystal structure of Sm-based metal organic complexes belongs to the hexagonal system, the space group is C2 / c, and the unit cell parameters are: α=γ=90°, β=90.008(4)°.

[0009] Another technical solution adopted by the present invention is a method for preparing a Sm-based metal organic complex, which specifically comprises: under closed conditions, in a glass bottle, the organic ligand 1-(imidazole-1-yl)-2,4,6-benzenetricarboxylic acid, Sm(NO3)3·6H2O, N,N-dimethylformamide, distilled water, and nitric acid are uniformly mixed and reacted under solvent thermal conditions to obtain a Sm-based metal organic complex.

[0010] The present invention is also characterized in that:

[0011] The solvent thermal reaction temperature is 100-140°C, and the required reaction time is 3-5 days.

[0012] The molar ratio of the organic ligand 1-(imidazol-1-yl)-2,4,6-benzenetricarboxylic acid to Sm(NO3)3·6H2O is 1:2, and every 0.05 mmol of Sm(NO3)3·6H2O corresponds to 5 mL of N,N-dimethylformamide, 3 mL of distilled water and 60 μL of nitric acid.

[0013] The beneficial effects of the present invention are that the Sm-based metal organic complex has good fluorescence properties, can detect the pesticide emamectin benzoate (EmB), and has a low detection limit, good selectivity and high sensitivity, and can be recycled multiple times to maximize economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The Sm in the Sm-based metal organic framework compound of the present invention 3+ Coordination environment diagram of the ion;

[0015] Figure 2 The connection mode diagram of the ligand ttc in the Sm-based metal organic framework compound of the present invention

[0016] Figure 3 2D structure diagram of the Sm-based metal organic framework compound of the present invention;

[0017] Figure 4 3D structure diagram of the Sm-based metal organic framework compound of the present invention;

[0018] Figure 5This is the fluorescence spectrum of Sm-MOF under the action of different pesticides;

[0019] Figure 6 The luminescence spectrum of Sm-MOF dispersed in aqueous solution when EmB is increased;

[0020] Figure 7 is the linear relationship between I0 / I-1 and EmB concentration;

[0021] Figure 8 This is a fluorescence intensity diagram of the Sm-MOF of the present invention when it is mixed with EmB at different concentrations. DETAILED DESCRIPTION

[0022] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] The Sm-based metal organic complex of the present invention has the chemical formula {[Sm(C 12 O6N2H 5.5 )(H2O)(HCOO) 0.5 ]·1.5H2O} n .

[0024] From the perspective of its microscopic crystal structure and skeleton connection construction, the crystal structure of Sm-based metal organic complexes belongs to the hexagonal system, the space group is C2 / c, and the unit cell parameters are: α=γ=90°, β=90.008(4)°.

[0025] The crystallographic data of the Sm-based metal organic complex of the present invention are shown in Table 1;

[0026] Table 1 Crystallographic data of Sm-based organometallic complexes

[0027]

[0028] The preparation method of the Sm-based metal organic complex of the present invention is specifically as follows:

[0029] Under sealed conditions, in a glass bottle, the organic ligand 1-(imidazol-1-yl)-2,4,6-benzenetricarboxylic acid (TTC), samarium nitrate hexahydrate (Sm(NO3)3·6H2O), N,N-dimethylformamide (DMF), distilled water, and nitric acid (HNO3) are uniformly mixed and reacted under solvothermal conditions at a temperature of 100-140°C for 3-5 days to obtain a Sm-based metal organic complex (Sm-MOF).

[0030] Among them, the molar ratio of the organic ligand ttc to Sm(NO3)3·6H2O is 1:2, and every 0.05 mmol of Sm(NO3)3·6H2O corresponds to 5 mL of N,N-dimethylformamide, 3 mL of distilled water and 60 μL of nitric acid solution (6 mmol / L).

[0031] The Sm-based metal organic complex of the present invention has good fluorescence properties, can be used to detect the pesticide emamectin benzoate (EmB), and has a low detection limit, good selectivity and high sensitivity.

[0032] Example 1

[0033] The preparation method of the Sm-based metal organic complex of the present invention is specifically as follows:

[0034] Under sealed conditions, in a glass bottle, the organic ligand 1-(imidazol-1-yl)-2,4,6-benzenetricarboxylic acid (TTC), samarium nitrate hexahydrate (Sm(NO3)3·6H2O), N,N-dimethylformamide (DMF), distilled water, and nitric acid (HNO3) were mixed uniformly and reacted under solvothermal conditions at a temperature of 100°C for 5 days to obtain a Sm-based metal organic complex (Sm-MOF).

[0035] Among them, the molar ratio of the organic ligand ttc to Sm(NO3)3·6H2O is 1:2, and every 0.05 mmol of Sm(NO3)3·6H2O corresponds to 5 mL of N,N-dimethylformamide, 3 mL of distilled water and 60 μL of nitric acid solution (6 mmol / L).

[0036] Example 2

[0037] The preparation method of the Sm-based metal organic complex of the present invention is specifically as follows:

[0038] Under sealed conditions, in a glass bottle, the organic ligand 1-(imidazol-1-yl)-2,4,6-benzenetricarboxylic acid (TTC), samarium nitrate hexahydrate (Sm(NO3)3·6H2O), N,N-dimethylformamide (DMF), distilled water, and nitric acid (HNO3) were mixed uniformly and reacted under solvothermal conditions at a temperature of 120°C for 3.5 days to obtain a Sm-based metal organic complex (Sm-MOF).

[0039] Among them, the molar ratio of the organic ligand ttc to Sm(NO3)3·6H2O is 1:2, and every 0.05 mmol of Sm(NO3)3·6H2O corresponds to 5 mL of N,N-dimethylformamide, 3 mL of distilled water and 60 μL of nitric acid solution (6 mmol / L).

[0040] Example 3

[0041] The preparation method of the Sm-based metal organic complex of the present invention is specifically as follows:

[0042] Under sealed conditions, in a glass bottle, the organic ligand 1-(imidazol-1-yl)-2,4,6-benzenetricarboxylic acid (TTC), samarium nitrate hexahydrate (Sm(NO3)3·6H2O), N,N-dimethylformamide (DMF), distilled water, and nitric acid (HNO3) were mixed uniformly and reacted under solvothermal conditions at a temperature of 140°C for 3 days to obtain a Sm-based metal organic complex (Sm-MOF).

[0043] Among them, the molar ratio of the organic ligand ttc to Sm(NO3)3·6H2O is 1:2, and every 0.05 mmol of Sm(NO3)3·6H2O corresponds to 5 mL of N,N-dimethylformamide, 3 mL of distilled water and 60 μL of nitric acid solution (6 mmol / L).

[0044] Figure 1 The Sm in the Sm-based metal organic complex prepared by the present invention 3+ The coordination environment diagram of the ion can be seen from the figure: the central Sm 3+ Three different coordination modes are used, 9-coordinated Sm 3+ Six oxygens come from four different carboxyl groups, two oxygens come from coordinated water molecules, and one oxygen comes from a formate group; Figure 2 This is a diagram showing the connection pattern of the ligand ttc in the Sm-based metal organic complex prepared in the present invention. It can be seen that one ttc ligand is connected to three Sm;

[0045] Figure 3 and Figure 4 The 2D and 3D structural diagrams of the Sm-based metal-organic complex prepared by the present invention are respectively, and a 3D porous metal-organic framework material with a microporous structure is formed by TTC connection;

[0046] Nine pesticides, including pyraclostrobin (Pst), pyrimethanil (Pth), imazalil (Ima), emamectin benzoate (EmB), myc, 2,4-epi, triadimefon (Pro), prochloraz (Tdi), and fluazinam (Flu), were mixed with Sm-based metal organic complexes, ultrasonically treated for 30 minutes, and aged for 3 days to form stable suspensions for fluorescence experiments. The photoluminescence spectra of different pesticides (20 μL, 10 mmol / L) (λex = 321 nm) were recorded. Figure 5As shown in Figure 2, it was found that Sm-MOF had a significant fluorescence enhancement effect on EmB. Further research on the fluorescence enhancement of Sm-MOF at room temperature showed that with the increase of Flu concentration (10mmol / L, 0μmol / L-60μmol / L), the fluorescence intensity gradually increased. When the concentration increased to 60μmol / L, the fluorescence enhancement reached the highest level (as shown in Figure 2). Figure 6 shown).

[0047] In order to more accurately study the relationship between the concentration of EmB and the fluorescence intensity, according to the Stern-Volmer equation: I0 / I=1+K SV [Q], where I0 is the initial luminescence intensity, I is the luminescence intensity after adding EmB, Q is the concentration of EmB, and K SV is the quenching constant. When the concentration increases to 60 μM, in the low concentration range of 5×10 -6 -2.5×10 -5 :Y=-13800.62331X-0.09928(R 2 =0.99339) shows a good linear relationship (such as Figure 7 According to the LOD=3σ / K equation, the detection limit (LOD) of EmB was calculated to be 10 -7 In addition, EmB can be selectively tested among the interferences of other pesticides. EmB (20 μL, 10 mmol / L) was added to the Sm-MOF suspension to a mixture containing other pesticides (20 μL, 10 mmol / L). After the addition of other pesticides, the fluorescence intensity did not increase sharply, but after the addition of equimolar EmB, the fluorescence enhancement was significant (e.g. Figure 8 Anti-interference experiments showed that the addition of EmB was not affected by the competition of other pesticides, proving that Sm-MOF has better selectivity for EmB.

Claims

1. Sm-based metal organic complex, characterized in that The chemical formula is {[Sm(C 12 O6N2H 5.5 )(H2O)(HCOO) 0.5 ]·1.5H2O} n ; The crystal structure of Sm-based metal organic complexes belongs to the hexagonal system, the space group is C2 / c, and the unit cell parameters are: α=γ=90°, β=90.008(4)°.

2. The method for preparing the Sm-based metal organic complex according to claim 1, wherein Specifically: In a sealed glass bottle, the organic ligand 1-(imidazol-1-yl)-2,4,6-benzenetricarboxylic acid, Sm(NO3)3·6H2O, N,N-dimethylformamide, distilled water, and nitric acid were mixed uniformly and reacted under solvothermal conditions to obtain a Sm-based metal organic complex. The solvent thermal reaction temperature is 100-140°C and the required reaction time is 3-5 days; The molar ratio of the organic ligand 1-(imidazol-1-yl)-2,4,6-benzenetricarboxylic acid to Sm(NO3)3·6H2O is 1:2, and every 0.05 mmol of Sm(NO3)3·6H2O corresponds to 5 mL of N,N-dimethylformamide, 3 mL of distilled water and 60 μL of nitric acid.

3. Application of the Sm-based metal organic complex as claimed in claim 1 in detecting the pesticide emamectin benzoate.

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