A pyridine zinc complex, its preparation method and application

Abstract

The present invention belongs to the technical field of luminescent materials, and particularly relates to a pyridine zinc complex, a preparation method thereof and an application. The present invention provides a pyridine zinc complex having the structure shown in Formula I. The pyridine zinc complex provided by the present invention can emit green afterglow when excited by an ultraviolet lamp with a wavelength of 365 nm, and emit orange afterglow when excited by an ultraviolet lamp with a wavelength of 395 nm, realizing long afterglow luminescence in the green and orange double color systems.

Description

Technical Field

[0001] The present invention belongs to the technical field of luminescent materials, and particularly relates to a zinc pyridine complex, a preparation method thereof, and an application thereof. Background Art

[0002] Long afterglow luminescent materials are materials that can store the energy of external light radiation such as ultraviolet light and visible light, and then slowly release this stored energy in the form of visible light at room temperature, and have important application values in the fields of information display, information encryption, and biological imaging.

[0003] The long afterglow phenomenon of long afterglow luminescent materials generally originates from the crystal defects of the matrix material, and these crystal defects can be generated by doping. The crystal defects lead to the generation of localized energy levels in the forbidden band energy level of the matrix. In the excitation stage, these localized energy levels can capture holes or electrons. When the excitation ends, these electrons or holes are released under the thermal action of the environment, and the energy is transferred to the activator ions to cause them to emit light. Since the thermal release of energy is a slow process, the luminescence of the activator ions exhibits the characteristics of long afterglow luminescence.

[0004] The existing long afterglow materials in the visible light region are mainly divided into red, yellow-green, and blue systems. However, most of the existing long afterglow materials are single-color systems. For example, Patent No. CN114369457A discloses a green long afterglow luminescent material; CN102585815A discloses an orange-red afterglow luminescent material. The single-color luminescence characteristics limit the application of long afterglow luminescent materials in the fields of information display, encryption, or imaging. Summary of the Invention

[0005] The purpose of the present invention is to provide a zinc pyridine complex, a preparation method thereof, and an application thereof. The zinc pyridine complex provided by the present invention can achieve green and orange dual-color long afterglow luminescence.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] The present invention provides a zinc pyridine complex having the structure shown in Formula I:

[0008]

[0009] Preferably, the zinc pyridine complex is monoclinic, the space group is P212121, and the unit cell parameters are α = 90°, β = 90°, γ = 90°,

[0010] The present invention also provides a preparation method of the zinc pyridine complex described in the above technical solution, including the following steps:

[0011] Mix the compound with the structure shown in Formula II, a water-soluble zinc salt, water, and a polar organic solvent, and obtain the pyridine zinc complex through a coordination reaction;

[0012]

[0013] Preferably, the water-soluble zinc salt includes one or more of zinc acetate, zinc nitrate, and zinc perchlorate.

[0014] Preferably, the molar ratio of the compound with the structure shown in Formula II to the water-soluble zinc salt is 1:4 to 2:1.

[0015] Preferably, one or more of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

[0016] Preferably, the volume ratio of water to the polar organic solvent is 1:2.5 to 10;

[0017] The molar amount of the compound with the structure shown in Formula II is in a ratio of 0.4 mmol:4 mL to the total volume of water and the polar organic solvent.

[0018] Preferably, the temperature of the coordination reaction is 100 to 160 °C, and the heat preservation time is 72 to 108 h.

[0019] Preferably, the heating rate for raising the temperature to the coordination reaction is 3 to 20 °C / min.

[0020] The present invention also provides the application of the pyridine zinc complex described in the above technical solution or the pyridine zinc complex prepared by the preparation method described in the above technical solution as a long afterglow luminescent material.

[0021] The present invention provides a pyridine zinc complex with the structure shown in Formula I. The pyridine zinc complex provided by the present invention can emit green afterglow after being excited by an ultraviolet lamp with a wavelength of 365 nm and emit orange afterglow after being excited by an ultraviolet lamp with a wavelength of 395 nm, realizing long afterglow luminescence in the green and orange double color systems. Through experimental characterization and theoretical calculation, it is confirmed that the multicolor emission of this compound is mainly caused by different aggregation states of the ligand. At the same time, the existence of coordination bonds promotes the charge separation inside the ligand, strengthens the intermolecular charge transfer, and further promotes the generation of charge transfer-induced room temperature phosphorescence. At the same time, the rigid structure of this complex effectively inhibits the rotation and vibration of the organic ligand, inhibits non-radiative transitions, and further enhances the generation of room temperature phosphorescence. Description of the Drawings

[0022] Figure 1 Schematic diagram of the coordination environment structure of Zn in the pyridine zinc complex obtained in Example 1;

[0023] Figure 2Schematic diagram of the smallest asymmetric unit structure in the zinc pyridine complex obtained in Example 1;

[0024] Figure 3 Schematic diagram of the dia structure of the zinc pyridine complex obtained in Example 1;

[0025] Figure 4 Schematic diagram of the three-dimensional structure of the zinc pyridine complex obtained in Example 1 along the c-axis;

[0026] Figure 5 XRD pattern of the zinc pyridine complex obtained in Example 1;

[0027] Figure 6 Thermogravimetric curve of the zinc pyridine complex obtained in Example 1;

[0028] Figure 7 Photoluminescence spectra of the zinc pyridine complex obtained in Example 1 under different excitation peaks;

[0029] Figure 8 Lifetime diagrams of the zinc pyridine complex obtained in Example 1 at different fluorescence peaks;

[0030] Figure 9 Phosphorescence spectra of the zinc pyridine complex obtained in Example 1 under different excitation peaks. Detailed implementation manners

[0031] The present invention provides a zinc pyridine complex having the structure shown in Formula I:

[0032]

[0033] In the present invention, the zinc pyridine complex is preferably monoclinic, with the space group P212121, and the unit cell parameters are α = 90°, β = 90°, γ = 90°,

[0034] In the present invention, the basic structure of the zinc pyridine complex is a three-dimensional network structure; the smallest asymmetric unit structural unit contains one Zn II ion and two molecules of the compound (1H-1,2,3-triazole[4,5-b]pyridine) having the structure shown in Formula II; wherein the Zn II ion is a four-coordinate structure, and the Zn II ion coordinates with one nitrogen atom from four 1H-1,2,3-triazole[4,5-b]pyridine molecules respectively to form a three-dimensional network structure; the Zn II ion forms a classical signature dia structure through 1H-1,2,3-triazole[4,5-b]pyridine molecules. There is no π-π interaction between the pyridyl groups of 1H-1,2,3-triazole[4,5-b]pyridine.

[0035] The present invention also provides a preparation method of the zinc pyridine complex described in the above technical solution, comprising the following steps:

[0036] Mix a compound having the structure shown in Formula II, a water-soluble zinc salt, water and a polar organic solvent, and obtain the zinc pyridine complex through a coordination reaction;

[0037]

[0038] In the present invention, unless otherwise specified, all preparation raw materials are commercially available products well-known to those skilled in the art.

[0039] In the present invention, the water-soluble zinc salt preferably includes one or more of zinc acetate, zinc nitrate and zinc perchlorate. In the present invention, the polar organic solvent preferably includes one or more of N,N-dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone.

[0040] In the present invention, the molar ratio of the compound having the structure shown in Formula II to the water-soluble zinc salt is 1:4 to 2:1. In the present invention, the volume ratio of water to the polar organic solvent is preferably 1:2.5 to 10, more preferably 1:3. In the present invention, the molar amount of the compound having the structure shown in Formula II to the total volume of water and the polar organic solvent is preferably 0.4 mmol:4 mL.

[0041] The present invention has no special limitation on the mixing process, and those well-known to those skilled in the art can be used.

[0042] In the present invention, the temperature of the coordination reaction is 100-160 °C, more preferably 110-150 °C, still more preferably 120-140 °C; the heating rate to the coordination reaction is 3-20 °C / min; the heat preservation time is 72-108 h. In the present invention, the coordination reaction is preferably carried out in a hydrothermal reaction kettle.

[0043] After the coordination reaction, the present invention also preferably includes sequentially cooling, filtering, washing and drying the obtained reaction liquor. In the present invention, the cooling is preferably natural cooling to room temperature. In the present invention, the drying method is preferably natural air drying at room temperature.

[0044] In the present invention, the yield of the zinc pyridine complex is preferably above 60%.

[0045] The preparation method provided by the present invention has the advantages of simple synthesis method, easy operation, good stability, high yield and good repeatability.

[0046] The present invention also provides the use of the zinc pyridine complex described in the above technical solution or the zinc pyridine complex prepared by the preparation method described in the above technical solution as a long afterglow luminescent material. The present invention has no special limitation on the specific implementation manner of the use, and those well-known to those skilled in the art can be adopted.

[0047] In the present invention, the zinc pyridine complex can emit green afterglow after being excited by an ultraviolet lamp with a wavelength of 365 nm, and emit orange afterglow after being excited by an ultraviolet lamp with a wavelength of 395 nm, realizing green and orange double-color long afterglow luminescence.

[0048] In order to further illustrate the present invention, the following describes in detail a zinc pyridine complex and its preparation method and use provided by the present invention in conjunction with the drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0049] Example 1

[0050] Dissolve 1H-1,2,3-triazole[4,5-b]pyridine (the compound shown in formula II, 48 mg, 0.4 mmol) and zinc acetate (44 mg, 0.2 mmol) in a mixed solvent of 4 mL of water and DMF (where the volume ratio of water to DMF is 1:3); place the obtained mixed system in a hydrothermal reaction kettle, heat it to 100 °C at a heating rate of 10 °C / h, and keep it warm for 3 days for coordination reaction; cool it to room temperature under natural conditions, and obtain brown granular crystals after filtration. Wash the collected massive crystals and dry them naturally at room temperature to obtain the zinc pyridine complex, and the yield is about 64.2%.

[0051] Example 2

[0052] Dissolve 1H-1,2,3-triazole[4,5-b]pyridine (the compound shown in formula II, 48 mg, 0.4 mmol) and zinc nitrate (60 mg, 0.2 mmol) in a mixed solvent of 4 mL of water and DMF (where the volume ratio of water to DMF is 1:3); place the obtained mixed system in a hydrothermal reaction kettle, heat it to 120 °C at a heating rate of 5 °C / h, and keep it warm for 3 days for coordination reaction; cool it to room temperature under natural conditions, and obtain brown granular crystals after filtration. Wash the collected massive crystals and dry them naturally at room temperature to obtain the zinc pyridine complex, and the yield is about 65.7%.

[0053] Performance Test

[0054] Test Example 1

[0055] Determine the crystal structure of the zinc pyridine complex obtained in Example 1;

[0056] The transparent crystal of the complex obtained in Example 1 was glued onto a capillary glass rod and placed at room temperature on a SuperNova, Singlesource at offset, Eos S2 X-ray single crystal diffractometer for testing. Using graphite monochromator filtered as the incident light source, diffraction intensity data was collected within a certain angular range in a / scan mode. The structure was analyzed using Olex2 and the Intrinsic Phasing in the ShelXT program package, and refined using the least squares method in the ShelXL program package;

[0057] The detailed crystal determination data obtained is shown in Table 1;

[0058] Table 1 Crystallographic data of the pyridine zinc complex obtained in Example 1

[0059]

[0060]

[0061] where R = [∑||F0|–|F c || / ∑|F0|], R W = ∑ W [|F0 2 –Fc 2 | 2 / ∑ W (|F w | 2 ) 2 1 / 2 ;

[0062] The important bond length data of the complex is shown in Table 2;

[0063] Table 2 Important bond length data of the pyridine zinc complex obtained in Example 1

[0064]

[0065]

[0066] The important bond angle data of the complex is shown in Table 3;

[0067] Table 3 Important bond angle data of the pyridine zinc complex obtained in Example 1

[0068]

[0069]

[0070] Symmetry codes: A: x, -y, z - 1 / 2; B: -x + 1 / 2, -y + 1 / 2, -z.​

[0071] The schematic diagram of the coordination environment structure of Zn in the obtained pyridine zinc complex is as shown in Figure 1 ; The schematic diagram of the structure of the smallest asymmetric unit in the complex is as shown in Figure 2 ; The schematic diagram of the dia structure of the complex is as shown in Figure 3 ; The schematic diagram of the three-dimensional structure of the complex along the c-axis is as shown in Figure 4 ; It can be seen from Figures 1 to 4 that the complex is a compound with a three-dimensional non-interpenetrating structure.

[0072] Test Example 2

[0073] The pyridine zinc complex obtained in Example 1 was subjected to X-ray diffraction test, and the obtained XRD pattern is as shown in Figure 5 ; It can be seen from Figure 5 that the pyridine zinc complex provided by the present invention is consistent with the simulated diffraction pattern, indicating that it has reliable phase purity, providing a guarantee for its application as an optical material.

[0074] Test Example 3

[0075] The thermal stability of the pyridine zinc complex obtained in Example 1 was tested;

[0076] A thermogravimetric analyzer with the instrument model SII EXStar6000 TG / DTA6300 was used to perform thermogravimetric analysis on the complex, and the obtained thermogravimetric analysis curve is as shown in Figure 6 ; It can be seen from Figure 6 that the framework of the complex can still stably exist at about 300 °C, having certain thermal stability, providing a thermal stability guarantee for its further development and application as a material. As the temperature rises, all the final organic ligands are lost, and the final product is metal oxide.

[0077] Test Example 4

[0078] After the pyridine zinc complex obtained in Example 1 was subjected to enrichment treatment, a fluorescence spectrophotometer with the instrument model HITACHI / F-7000 was used to test the solid fluorescence spectrum and fluorescence lifetime of the complex, and the obtained test results are as shown in Figure 7 and Figure 8 ; Among them, Figure 7 is the photoluminescence spectrum of the pyridine zinc complex obtained in Example 1 under different excitation peaks; Figure 8 is the lifetime diagram of the pyridine zinc complex obtained in Example 1 at different fluorescence peaks

[0079] It can be seen from Figure 7It can be seen that at different excitation wavelengths, the peak positions of the fluorescence emission peaks of the complex remain basically unchanged. As the excitation peak changes from 280 to 320 nm, the emission peaks in the range of 250 to 350 nm have unchanged positions except for the change in emission intensity;

[0080] From Figure 8 It can be seen that the fluorescence lifetimes of the complex at 330 nm, 344 nm, 360 nm, and 405 nm are 3.63 ns, 9.47 ns, 4.12 ns, and 12.03 ns, respectively.

[0081] Test Example 5

[0082] After the zinc pyridine complex obtained in Example 1 was enriched, a solid phosphorescence test of the complex was carried out using an Edinburgh FLS1000 steady-state transient fluorescence spectrometer with the instrument model number, and the test results obtained are as Figure 9 shown;

[0083] From Figure 9 It can be seen that at different excitation wavelengths, the phosphorescence emission peaks of the complex are constantly changing, showing excitation wavelength-dependent dynamic phosphorescence properties. The specific test results are as follows: When the complex is excited every 5 nm from 240 to 255 nm, the positions of the emission peaks are around 400 nm and around 550 nm. Among them, the emission peak near 400 nm gradually weakens and disappears compared with the emission peak near 550 nm. Under the excitation of 365 nm ultraviolet light, when the ultraviolet lamp is turned off, a visible green afterglow is emitted. Under the excitation of 395 nm ultraviolet light, when the ultraviolet lamp is turned off, a visible orange afterglow is emitted.

[0084] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, not all embodiments. Other embodiments can be obtained according to this embodiment without creative work, and these embodiments all belong to the protection scope of the present invention.

Claims

1. A pyridine zinc complex, characterized in that, The basic structure of the pyridine zinc complex is a three-dimensional network structure; the smallest asymmetric unit structural unit contains one Zn II ion and two 1H-1,2,3-triazole[4,5-b]pyridine molecules; among them, Zn II ion is a four-coordinate structure, and the Zn II ion coordinates with one nitrogen atom from four 1H-1,2,3-triazole[4,5-b]pyridine molecules respectively to form a three-dimensional network structure; the Zn II ion forms a dia structure through 1H-1,2,3-triazole[4,5-b]pyridine molecules; There is no π-π interaction between the pyridyl groups of the 1H-1,2,3-triazole[4,5-b]pyridine; The pyridine zinc complex is monoclinic, with the space group P212121 and the unit cell parameters as α = 90°, β = 90°, γ = 90°, 2. The preparation method of the pyridine zinc complex according to claim 1, characterized in that, It includes the following steps: Mix the compound with the structure shown in Formula II, water-soluble zinc salt, water and polar organic solvent, and obtain the pyridine zinc complex through a coordination reaction; 3. The preparation method according to claim 2, characterized in that, The water-soluble zinc salt includes one or more of zinc acetate, zinc nitrate and zinc perchlorate.

4. The preparation method according to claim 2 or 3, characterized in that, The molar ratio of the compound with the structure shown in Formula II to the water-soluble zinc salt is 1:4 to 2:

1.

5. The preparation method according to claim 2, wherein The polar organic solvent includes one or more of N,N-dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone.

6. The preparation method according to claim 2 or 5, characterized in that The volume ratio of water to the polar organic solvent is 1:2.5 to 10; The molar amount of the compound with the structure shown in Formula II and the total volume of the water and the polar organic solvent are in a ratio of 0.4 mmol:4 mL.

7. The preparation method according to claim 2, characterized in that, The temperature of the coordination reaction is 100 to 160 °C, and the heat preservation time is 72 to 108 h.

8. The preparation method according to claim 7, wherein, The heating rate for raising the temperature to the coordination reaction is 3 to 20 °C / min.

9. Use of the pyridine zinc complex described in claim 1 or the pyridine zinc complex prepared by the preparation method described in any one of claims 2 to 8 as a long afterglow luminescent material.

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