A single crystal of a Zn(II) complex, its preparation method and applications

Abstract

The present invention belongs to the fields of coordination chemistry and detection, and discloses a single crystal of a Zn(II) complex and a preparation method thereof. Its chemical formula is: {[Zn2(H3BTB)2L2]∙H2O} n , where H3BTB is 1,3,5-tris(4-carboxyphenyl)benzene, and L is 1,4-bis(1-imidazolyl)benzene; it belongs to the monoclinic system, and the space group is P 21 / c , a =12.220(2) Å, b =16.319(3) Å, c =34.256(7) Å, α =90.000°, β =93.74(3)°, γ =90.000°, V =6816.7(2) Å 3 . Zinc nitrate hexahydrate, 1,3,5-tris(4-carboxyphenyl)benzene, and 1,4-bis(1-imidazolyl)benzene are dissolved in N,N'-dimethylformamide and distilled water, sealed in a reaction flask, and ultrasonically prepared at room temperature. This complex can stably exist in water, has good stability, and is convenient to use. It can be used as a probe to detect norfloxacin and mesotrione in water, realizing qualitative and quantitative detection.

Description

Technical Field

[0001] The present invention relates to the fields of coordination chemistry and detection, and particularly relates to a Zn(II) complex single crystal capable of detecting the contents of norfloxacin and mesotrione in water and a preparation method thereof. Background Art

[0002] Norfloxacin is a synthetic antibacterial drug mainly used for antibacterial and anti-inflammatory purposes. Currently, norfloxacin is widely used in human and livestock treatment as well as aquaculture. However, most of the norfloxacin cannot be completely absorbed by the human body or animals, and the unabsorbed part will be discharged into the environment in the form of metabolites. At present, different levels of norfloxacin content have been detected in some water bodies, mainly in surface water. Long-term drinking of surface water containing norfloxacin by people can induce heart disease, stroke and decreased body resistance (Inorganic Chemistry, 2021, 60, 16966 - 16976). Therefore, the monitoring and control of norfloxacin in drinking water are of great significance. Mesotrione is a broad-spectrum selective herbicide used before and after corn seeding. Some studies have shown that mesotrione has strong solubility in alkaline environments and will cause a certain degree of pollution to surface water and groundwater. Therefore, the monitoring and control of mesotrione in drinking water are equally of great significance.

[0003] For this reason, many researchers have developed numerous methods for detecting norfloxacin and mesotrione. Fluorescence analysis has been widely used due to its characteristics such as short response time, simple operation, high sensitivity, and good selectivity, which has led researchers to be committed to constructing various fluorescence probes (Inorganic Chemistry, 2022, 61, 16952 - 16962). In recent years, metal-organic framework materials (MOFs) have been widely used in the detection of various antibiotics and pesticides because of their large specific surface area, permanent porosity, adjustable chemical functions, finely tunable pore structures, and in particular, various functional groups can be reasonably introduced to modify the microporous structure by metal ligands (Inorganic Chemistry, 2022, 61, 3942 - 3950), thus generating more active sites. Referring to the literature, modifying carboxyl groups on metal-organic frameworks can well detect norfloxacin and mesotrione. Carboxyl groups are prone to react with the amino group in norfloxacin and the alkoxy group in mesotrione. Since carboxyl groups belong to electron-withdrawing groups and amino groups and alkoxy groups belong to strong electron-donating groups, this makes the detection easier to carry out. Therefore, designing and synthesizing a carboxyl-group-modified metal-organic framework probe with a fast response speed, simple operation, high sensitivity, and wide detection range is more conducive to detecting norfloxacin and mesotrione in water. Summary of the Invention

[0004] The object of the present invention is to provide a metal-organic framework probe with high sensitivity, wide detection range, fast response speed and simple operation, and apply it to the detection of norfloxacin and mesotrione. Another object is to provide a preparation method thereof.

[0005] To achieve the object of the present invention, a single crystal of Zn(II) complex was synthesized.

[0006] Its chemical formula is: {[Zn2(H3BTB)2L2]·H2O} n , where H3BTB is 1,3,5-tris(4-carboxyphenyl)benzene and L is 1,4-bis(1-imidazolyl)benzene; it belongs to the monoclinic system, and the space group is P21 / c, α = 90.000°, β = 93.74(3)°, γ = 90.000°,

[0007] The preparation method of the probe of the present invention: Dissolve zinc nitrate hexahydrate, 1,3,5-tris(4-carboxyphenyl)benzene and 1,4-bis(1-imidazolyl)benzene in N,N'-dimethylformamide and distilled water, seal them in a reaction flask, ultrasonicate at room temperature, place them in a constant-temperature oven, and then cool to room temperature to obtain colorless transparent block crystals, and obtain the target product, that is, the Zn(II) single crystal probe.

[0008] This complex can be used as a probe to detect norfloxacin and mesotrione in water, realizing qualitative and quantitative detection.

[0009] The advantages of the present invention are as follows: The Zn(II) complex single crystal can stably exist in water, and carboxyl groups are modified in the pores of its three-dimensional framework structure, which is beneficial to the interaction with norfloxacin and mesotrione, and thus can quickly and sensitively detect norfloxacin and mesotrione in water. When detecting the concentration of norfloxacin in water, it has a wide detection range (1 - 300 μM), a low detection limit (0.21 μM) and a short response time (1 minute). Similarly, when detecting the concentration of mesotrione in water, it also has a wide detection range (1 - 30 μM), a low detection limit (0.054 μM) and a short response time (1 minute). In addition, the preparation process of the present invention is simple, the yield is high, and it has good application prospects. Description of the Drawings

[0010] Figure 1 It is the coordination environment diagram of Zn(II) in the Zn(II) complex crystal of the present invention;

[0011] Figure 2 It is the single crystal structure diagram of the probe of the present invention (a: one-dimensional structure diagram b: three-dimensional structure diagram);

[0012] Figure 3 Comparison diagram of single-crystal simulated powder diffraction pattern, experimental powder diffraction pattern and powder diffraction pattern after soaking in water for 24 hours of the probe of the present invention; 1 is the single-crystal simulated powder diffraction pattern, 2 is the powder diffraction pattern of the Zn(II) complex of the present invention, and 3 is the powder diffraction pattern of the probe of the present invention after soaking in water for 24 hours;

[0013] Figure 4 Fluorescence intensity change diagram of the probe of the present invention for detecting the concentration of norfloxacin in water (excitation peak: 292 nm, emission peak: 310 - 500 nm);

[0014] Figure 5 Linear range of the probe of the present invention for detecting the concentration of norfloxacin in water;

[0015] Figure 6 Fluorescence intensity change diagram of the probe of the present invention for detecting the concentration of mesotrione in water (excitation peak: 292 nm, emission peak: 310 - 500 nm);

[0016] Figure 7 Linear range of the probe of the present invention for detecting the concentration of mesotrione in water. Detailed implementation mode

[0017] The present invention will be further described below through examples:

[0018] Example 1: Synthesis of Zn(II) single-crystal probe

[0019] Zinc nitrate hexahydrate (17.8 mg, 0.06 mmol), 1,3,5-tris(4-carboxyphenyl)benzene (13.2 mg, 0.03 mmol) and 1,4-bis(1-imidazolyl)benzene (6.3 mg, 0.03 mmol) were dissolved in N,N'-dimethylformamide (3 mL) and water (3 mL), sealed in a reaction flask, and kept at a constant temperature of 100 °C for two days under solvothermal conditions, and then cooled to room temperature to obtain colorless transparent block crystals. The molecular formula of the colorless block crystals is: {[Zn2(H3BTB)2L2]·H2O}, which is the Zn(II) single-crystal probe.

[0020] Select single crystals of appropriate size under a microscope for X-ray diffraction experiments at room temperature. On a Bruker SmartApex-II CCD diffractometer, using Mo-K radiation monochromatized by a graphite monochromator Diffraction data were collected in the φ–ω mode. Data reduction was carried out using the Bruker SAINT program. Absorption correction for the diffraction data of partial structures was performed using the SADABS program. The crystal structure was solved by direct methods combined with difference Fourier synthesis. All non-hydrogen atom coordinates and anisotropic parameters were refined by full-matrix least-squares methods, and the positions of C–H atoms were determined according to the theoretical model. The coordination environment diagram of the metal zinc in the complex is shown in Figure 1 ; The crystal structure diagram of the complex is shown in Figure 2 ; The detailed crystal determination data are shown in Table 1.

[0021] Table 1 Main crystallographic data of the complex

[0022]

[0023]

[0024] Example 2: Application of the Zn(II) single crystal probe of the present invention in detecting the concentrations of norfloxacin and mesotrione in water

[0025] First, the Zn(II) single crystal probe synthesized in the present invention was ground in an agate mortar for 1 hour, and then 3 mg of the ground sample was added to 10 mL of distilled water to obtain a 0.3 mg mL -1 suspended Zn(II) probe. Secondly, different concentrations of norfloxacin were added to the 0.3 mg mL -1 suspended Zn(II) probe. After equilibration for 1 minute, the fluorescence change was detected using an Edinburgh fluorescence spectrometer, as shown in Figure 4 . And it showed a good linear range, as shown in Figure 5 . Then, different concentrations of mesotrione were added to the 0.3 mg mL -1 suspended Zn(II) probe. After equilibration for 1 minute, the fluorescence change was detected using an Edinburgh fluorescence spectrometer, as shown in Figure 6 . And it showed a good linear range, as shown in Figure 7 . This probe can well detect the concentration of 1 - 300 μM norfloxacin and the concentration of 1 - 30 μM mesotrione in water.

Claims

1. Application of the single crystal of the Zn(II) complex, characterized in that, Using it as a probe to qualitatively or quantitatively detect norfloxacin or mesotrione in water; the chemical formula of the single crystal of the Zn(II) complex is: {[Zn2(H3BTB)2L2]∙H2O} n , where H3BTB is 1,3,5-tris(4-carboxyphenyl)benzene and L is 1,4-bis(1-imidazolyl)benzene; it belongs to the monoclinic system and the space group is P 21 / c , a = 12.220(2) Å, b = 16.319(3) Å, c = 34.256(7) Å, α = 90.000°, β = 93.74(3)°, γ = 90.000°, V = 6816.7(2) Å 3 .

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