A single-component white light-emitting coordination polymer
The single-component white light coordination polymer [Zn(bpdo)(fum)(H2O)2]n synthesized by solvothermal reaction solves the problems of white light emission instability and chromaticity difference in the prior art, and achieves the white light emission and photochromic effects with high color rendering index.
Patent Information
- Application Number
- CN202310582883.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-23
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2043-05-23
AI Technical Summary
In the prior art, the three primary color LED chip stacking method and the dye doping method have problems such as complex preparation, high cost and poor luminescence stability, while the composite method cannot achieve white light emission alone, and the existing zinc coordination polymer has poor color development.
The single-component white light coordination polymer [Zn(bpdo)(fum)(H2O)2]n was synthesized by solvothermal reaction, and a two-dimensional layered structure was formed with fumaric acid and 4,4'-bipyridine-N,N'-dioxide and Zn ions were used to form a two-dimensional layered structure, which emitted white light at an excitation wavelength of 320-370 nm, and photochromic was achieved under the irradiation of xenon lamp.
A high color rendering index white light emission in the excitation wavelength range of 320-370nm is achieved, and photochromic occurs under light, with high thermal stability and chromogenicity.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of metal complexes, in particular to a single-component white light coordination polymer. Background Art
[0002] White light-emitting diodes (WLEDs) have attracted widespread attention due to their advantages in energy conservation and device miniaturization in solid-state lighting and displays. Three typical approaches to achieving WLEDs are used: 1) combining red, green, and blue (RGB) LED chips; 2) coating blue LED chips with yellow phosphors; and 3) coating ultraviolet LED chips with a mixture of RGB phosphors. The disadvantages of stacking blue, green, and red primary color emitting layers are the complex preparation process and high cost, poor voltage stability of the emission color, and the multilayer structure is prone to self-absorption, which reduces the quantum yield of light. The disadvantage of the dye doping method is that it is difficult to achieve high energy transfer efficiency between the host luminescent material and the guest dye material, which affects the luminescence of the guest dye. Furthermore, the dye concentration and applied voltage significantly affect the emission color and efficiency. Improper concentration control can lead to poor chromaticity and low efficiency. The composite method also has the disadvantage that it requires a combination of other methods to achieve white light emission, and cannot achieve a white light-emitting device solely through exciplexes or the addition of a hole-blocking layer.
[0003] Single-component white light luminescent materials not only overcome the above shortcomings, but also have the advantages of simple preparation and high color reproducibility, and have attracted much attention in recent years. Metal-organic frameworks (MOFs), as an emerging crystalline material, have rich and diverse structures, which give them great advantages in catalysis, gas capture and purification, magnetism and other fields. Luminescent MOFs (LMOFs) have shown various applications, such as optoelectronic devices and sensors. The study of Zn-MOFs as luminescent sensors has also attracted attention. For example, Xie Yangbin et al. (Synthetic Chemistry, 2020, 28 (7), 632-636) studied the synthesis of new zinc (II) coordination polymers and their near-white light temperature sensing properties. A new Zn (II) complex [Zn2 (L) 2 (bpe) 2] n was synthesized under hydrothermal conditions. Under an excitation wavelength of 380 nm, the complex has a strong emission peak at 550 nm. However, if zinc coordination polymers are to be used in industrial production, new single-component white light materials need to be developed, which is of great importance and urgent significance for improving the performance of white light emitting diodes. Summary of the Invention
[0004] In response to the above-mentioned prior art, the present invention aims to provide a single-component white-light coordination polymer. This invention synthesizes a single-component crystalline white-light coordination polymer using a solvothermal reaction in a single step. This compound emits white light within the excitation wavelength range of 320-370nm and exhibits a high color rendering index.
[0005] To achieve the above object, the present invention adopts the following technical solutions:
[0006] In a first aspect of the present invention, a single-component white light coordination polymer is provided, wherein the chemical formula of the single-component white light coordination polymer is [Zn(bpdo)(fum)(H2O)2] n , where bpdo represents 4,4′-bipyridine-N,N′-dioxide and fum represents fumaric acid.
[0007] Preferably, the structural unit of the single-component white light coordination polymer is a triclinic system, the space group is P1, and the unit cell parameters are α=87.312(7)°, β=82.988(8)°, γ=73.760(8)°.
[0008] Preferably, the unit cell volume of the single-component white light coordination polymer is
[0009] Preferably, the number of molecules Z in the unit cell of the single-component white light coordination polymer is 1.
[0010] Preferably, the single-component white light coordination polymer emits white light in an excitation wavelength range of 320-370 nm.
[0011] More preferably, the single-component white light coordination polymer has a color coordinate of (0.24, 0.25) and a color temperature of 91.3 at a laser wavelength of 330 nm, a color coordinate of (0.24, 0.25) and a color temperature of 92.1 at a laser wavelength of 340 nm, a color coordinate of (0.25, 0.26) and a color temperature of 91.8 at a laser wavelength of 350 nm, a color coordinate of (0.26, 0.27) and a color temperature of 90.7 at a laser wavelength of 360 nm, and a color coordinate of (0.27, 0.30) and a color temperature of 88.4 at a laser wavelength of 370 nm.
[0012] Preferably, the single-component white light coordination polymer changes color under irradiation with a 200W xenon lamp: gradually changes from pink to yellow-green within 5 minutes.
[0013] The second aspect of the present invention provides a method for preparing the above-mentioned single-component white light coordination polymer, the method comprising:
[0014] 4,4′-bipyridine-N,N′-dioxide, fumaric acid and ZnSO4·7H2O were added to a mixed solution of DMF, anhydrous ethanol and distilled water for a solvothermal reaction. The resulting product was filtered to obtain pink block crystals, which were single-component white light-emitting coordination polymers.
[0015] Preferably, the ratio of the added amounts of 4,4′-bipyridine-N,N′-dioxide, fumaric acid, ZnSO4·7H2O, DMF, anhydrous ethanol and distilled water is 0.1 mmol: 0.1 mmol: 0.094 mmol: 3 mL: 3 mL: 3 mL.
[0016] Preferably, the temperature of the solvent thermal reaction is 80-100° C., and the time is 12-36 hours.
[0017] The third aspect of the present invention provides the use of a single-component white light coordination polymer in preparing a white light emitting device and a photochromic device.
[0018] Beneficial effects of the present invention:
[0019] The present invention synthesizes a single-component white-light-emitting coordination polymer crystalline material in a single step using a solvothermal reaction. The compound emits white light within an excitation wavelength range of 320-370 nm and exhibits a high color rendering index. Furthermore, the single-component white-light-emitting coordination polymer crystalline material prepared by the present invention exhibits photochromic properties under irradiation with a 200W xenon lamp, achieving both high-color rendering index white light emission and photochromic properties. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 :Crystal structure diagram of single-component white light coordination polymer;
[0021] Figure 2 : XRD pattern of single-component white light coordination polymer;
[0022] Figure 3 : Thermogravimetric curves of single-component white light coordination polymers under nitrogen atmosphere;
[0023] Figure 4 : Emission spectrum of the single-component white light coordination polymer at an excitation wavelength of 320-370 nm (a), (b) white light photograph of compound 1 under 365 nm ultraviolet light irradiation, and the corresponding color coordinates (c).
[0024] Figure 5 : Photos (a) and solid-state UV spectra (b) of single-component white light coordination polymers under different illumination times. DETAILED DESCRIPTION
[0025] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.
[0026] As described in the background technology section, the zinc coordination polymers in the prior art can only emit near-white light with poor color rendering. Based on this, the purpose of the present invention is to provide a single-component white light coordination polymer. The crystal structure of the single-component white light coordination polymer of the present invention is as follows: Figure 1 As shown, in the crystal structure of the zinc metal coordination polymer of the present invention, each Zn(II) ion is coordinated with two fumaric acid ligands, two 4,4'-bipyridyl-N,N'-dioxide ligands, and two water molecules to form a two-dimensional layered structure. Fumaric acid acts as an electron donor, and 4,4'-bipyridyl-N,N'-dioxide acts as an electron acceptor. Under excitation from a xenon lamp, photoinduced electron transfer occurs, resulting in photochromic properties. Furthermore, due to the synergistic coordination between fumaric acid, 4,4'-bipyridyl-N,N'-dioxide, and the Zn(II) ion, white light emission is generated under excitation from ultraviolet light in the 320-370nm range.
[0027] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below with reference to specific embodiments.
[0028] The test materials used in the examples of the present invention are all conventional test materials in the art and can be purchased through commercial channels.
[0029] Example
[0030] 4,4′-Bipyridine-N,N′-dioxide (bpdo, 0.1 mmol, 20 mg), fumaric acid (fum, 0.1 mmol, 11 mg) and ZnSO4·7H2O (0.094 mmol, 27 mg) were added to a mixed solution of 3 mL DMF, 3 mL anhydrous ethanol and 3 mL distilled water. The mixture was placed in a 17 mL stainless steel reactor and reacted at 90°C for 1 day. Pink block crystals were obtained by filtration.
[0031] Characterization:
[0032] During the determination of the crystal structure of the zinc metal coordination polymer, a single crystal of suitable size was selected and placed on a Gemimi E / xx-9100CCD X-ray diffractometer with a graphite monochromator (Agilent Gemimi E / xx-9100 CCD four-circle single crystal diffractometer, USA). α(λ = 1.54184 nm) radiation was used, and data were collected in ω / 2θ scanning mode at 293(2) K. All diffraction intensity data were corrected by LP factors and empirical absorption, and the crystal structure was solved by direct method. The structure analysis was completed using the Olex2 program, and the coordinates of all non-hydrogen atoms and anisotropy parameters were refined by full matrix least squares F2 refinement.
[0033] The crystallographic data of the single-component white light coordination polymer prepared in the examples are shown in Table 1.
[0034] Table 1
[0035]
[0036] Note: a R1=∑||F o |–|F c || / ∑|F o |; b ωR2={∑ω[(F o ) 2 –(F c ) 2 ] 2 / ∑ω[(F o )2] 2} 1 / 2 .
[0037] The purity of the single-component white light coordination polymer prepared in the example (experimental peak) can be confirmed by comparing it with the simulated X-ray powder peak, such as Figure 2 As shown. This shows that the prepared zinc metal coordination polymer sample is pure phase. The single component white light coordination polymer prepared in Example can be stable to at least 185℃ (such as Figure 3 ), indicating that the prepared zinc metal coordination polymer sample has high thermal stability.
[0038] Note: The experimental peaks were obtained by X-ray powder diffractometer testing of the single-component white light coordination polymer prepared in Example 1; while the simulated peaks were obtained by converting the single crystal cif file using Mercury software. This allows the comparison of the two to indicate whether the bulk synthesized crystal powder is pure phase.
[0039] Test Example 1: White light test
[0040] The coordination polymers prepared in the example were placed in an FLS1000 fluorescence spectrometer, and five fluorescence emission spectra were obtained at excitation wavelengths of 330 nm, 340 nm, 350 nm, 360 nm, and 370 nm. The color coordinates and color temperatures obtained by processing and converting the emission spectrum data using CIE caculator-version 3 software are shown in Tables 2 and Figure 4 .
[0041] Table 2
[0042] Excitation wavelength (nm) Color coordinates Color temperature 330 (0.24,0.25) 91.3 340 (0.24,0.25) 92.1 350 (0.25,0.26) 91.8 360 (0.26,0.27) 90.7 370 (0.27,0.30) 88.4
[0043] From Table 2 and Figure 4 It can be seen that the complex prepared in the present invention can emit white light at an excitation wavelength of 330-370 nm, its color coordinates are all within the range of white light, and has a high color rendering index.
[0044] The coordination polymer prepared in the example was irradiated with a 365nm ultraviolet lamp, and the coordination polymer emitted white light. Figure 4 (b).
[0045] Test Example 2: Photochromic Test
[0046] The coordination polymer prepared in the embodiment was arranged into the shape of an eighth note, and a 200W xenon lamp was used to simulate sunlight to irradiate the note. Figure 5 (a) It can be seen that after 1 minute of irradiation, the note changes from pink to yellow, and after 5 minutes of irradiation, the note changes from pink to yellow-green. Figure 5 As shown in (b), the ultraviolet absorption spectrum gradually increases in the range of 400-1200 nm, indicating that the single-component white light coordination polymer prepared in the present invention has photochromic properties.
[0047] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.
Claims
1. Use of a single-component white light coordination polymer in the preparation of a white light emitting device, characterized in that: The chemical formula of the single-component white light coordination polymer is [Zn(bpdo)(fum)(H2O)2] n , wherein bpdo represents 4,4′-bipyridine-N,N′-dioxide, and fum represents fumaric acid; the single-component white light coordination polymer emits white light in the excitation wavelength range of 320-370 nm; the structural unit of the single-component white light coordination polymer is triclinic system, the space group is P1, and the unit cell parameters are a = 5.3563(5)Å, b = 7.3075(6)Å, c = 9.7457(9)Å, α = 87.312(7)°, β = 82.988(8)°, γ = 73.760(8)°; The single-component white light coordination polymer is prepared by the following method: 4,4′-bipyridine-N,N′-dioxide, fumaric acid, and ZnSO4∙7H2O were added to a mixed solution of DMF, anhydrous ethanol, and distilled water for a solvothermal reaction. Pink block crystals were obtained by filtration, which is a single-component white light coordination polymer. The ratio of the added amounts of 4,4′-bipyridine-N,N′-dioxide, fumaric acid, ZnSO4∙7H2O, DMF, anhydrous ethanol and distilled water is 0.1 mmol: 0.1 mmol: 0.094 mmol: 3 mL: 3 mL: 3 mL.
2. The use according to claim 1, characterized in that The unit cell volume of the single-component white light coordination polymer is V = 363.47(6)Å 3 .
3. The use according to claim 1, characterized in that The number of molecules Z in the unit cell of the single-component white light coordination polymer is 1.
4. The use according to claim 1, characterized in that The single-component white light coordination polymer changes color under irradiation with a 200W xenon lamp: gradually changes from pink to yellow-green within 5 minutes.
5. The use according to claim 1, characterized in that The temperature of the solvent thermal reaction is 80-100° C., and the time is 12-36 h.