{Cd3}-MOF hybrid materials containing various trinuclear clusters, their preparation methods, and their applications in the preparation of tunable white light HLEDs

Abstract

The present invention provides a {Cd3}-MOF hybrid material containing multiple trinuclear clusters, the general chemical formula of which is {[Cd 12 (npd) 12 (tpt)4(H2O)2](H2O) 10} n , belongs to the triclinic system, space group is P-1, unit cell parameters, in the chemical formula, component npd 2‑ It is obtained by removing two protons from the organic carboxylic acid H2npd. The structures of the components H2npd and TPT are shown in the following formula. The {Cd3}-MOF hybrid material prepared by the present invention is a porous three-dimensional metal-organic framework. The raw materials are readily available, the preparation conditions are mild, the operation is simple, the yield is about 75%, the physical phase purity is high, and it has good thermal stability. The hybrid light-emitting diode HLED prepared from this fluorescent hybrid material can emit tunable white light that changes with the current intensity during operation, and the white light wavelength covers the 400-760nm visible light band.

Description

Technical Field

[0001] The present application belongs to the field of advanced fluorescent materials, and specifically relates to {Cd3}-MOF hybrid materials containing multiple trinuclear clusters, their preparation methods, and their applications in the preparation of tunable white light HLEDs. Background Art

[0002] Traditional light-emitting diodes (LEDs), known as LEDs, offer energy-saving, long lifespans, and compact size. They are widely used in indication, display, and lighting applications, representing the most significant lighting revolution of the 20th century. Since the 1960s, red and orange LEDs have been developed using semiconductor luminescent materials containing elements such as gallium (Ga), arsenic (As), phosphorus (P), and nitrogen (N). Following the advent of blue diodes in the late 1980s, chip coating with inorganic phosphors became the mainstream technology for LED manufacturing. The resulting LEDs are also known as "electro-optical" LEDs. Because both the chip's luminescent element and the phosphor are inorganic and contain no carbon or hydrogen, they are also known as inorganic light-emitting diodes in the industry. The inorganic phosphors used are primarily mixtures or composites of various metal oxides, typically exceeding 60% metal content. These phosphors are dense and difficult to recycle.

[0003] In the chemical industry, inorganic-organic hybrid materials (Hybrid Materials) refer to solid functional materials composed of inorganic and organic compounds. They can be simply divided into disordered hybrid materials (mixtures) and ordered hybrid materials (pure substances). Ordered hybrid materials are pure substances obtained by chemical reactions between inorganic and organic raw materials. They have a well-defined structure, low density, diverse properties, and a wide range of applications. Their limited metal content facilitates degradation and recycling, making them a key research topic in the field of new materials. Since the ordered hybrid material 8-hydroxyquinoline aluminum (AlQ3) was used in the manufacture of light-emitting devices in 1987, fluorescent metal-organic hybrid materials, including metal-organic frameworks (MOFs), coordination polymers, and coordination supramolecular materials, have become important advanced luminescent materials. Electro-optical light-emitting diodes (LEDs) fabricated using fluorescent hybrid materials instead of inorganic phosphors are called hybrid light-emitting diodes (HLEDs).

[0004] Fluorescent MOF hybrid materials with porous structures not only possess structural order, excellent stability, high transmittance, and low density, but also exhibit excellent luminescence properties. Because rare earths are the "vitamins" of the metallurgical industry and a non-renewable national strategic resource, while common transition metal salts are inexpensive and readily available, non-rare earth fluorescent MOF hybrid materials have become a highly sought-after new material, potentially replacing or partially replacing rare earth-based phosphors. However, due to the complex microscopic processes of chemical reactions and the numerous influencing factors, predicting the structure and structure-activity relationship of MOF materials remains difficult, making it a challenging and cutting-edge research topic. Summary of the Invention

[0005] To achieve the above object, the present invention provides the following technical solution: a {Cd3}-MOF hybrid material containing multiple trinuclear clusters, the general chemical formula of which is {[Cd 12 (npd) 12 (tpt)4(H2O)2](H2O) 10} n , belongs to the triclinic system, space group is Pī, unit cell parameters In the chemical formula, component npd 2- It is obtained by removing two protons from an organic carboxylic acid H2npd. The structure of H2npd is shown in Formula I. The structure of component tpt is shown in Formula II.

[0006]

[0007] Furthermore, in the asymmetric unit of the crystal structure of the {Cd3}-MOF hybrid material, 12 crystallographically independent Cd 2+ ions, 12 npd 2- , 4 tpt, 2 coordinated water molecules and 10 lattice water molecules; the organic component npd 2- Four coordination modes are adopted to bridge two Cd 2+ ions or 3 Cd 2+ ions or 4 Cd 2+ ions; Cd 2+ Among the coordination numbers of ions, Cd2, Cd3, Cd5, and Cd11 have a coordination number of 7, and the rest of Cd 2+ The coordination number of the ion is 6; the bond lengths of Cd-O and Cd-N range from Carboxylate, pyridinic N and water molecules form four different trinuclear clusters {Cd3}; the organic component npd 2- The coordination modes of tpt and tpt are shown in formula III to VII, where M represents metal Cd 2+ ions; Cd 2+The coordination patterns are shown in formulas VIII to XI, and the numbers on the right side of the element symbols represent the atom numbers in the asymmetric unit.

[0008]

[0009] Furthermore, in the spatial structure of the {Cd3}-MOF hybrid material, there is a π…π interaction between the aromatic rings of the [Cd3(tpt)] structural unit, and the interplanar spacing is Then form supramolecular chain [Cd3(tpt)] n The above three-core cluster {Cd3} can be simplified into 7-connected nodes, and the organic component npd 2- and tpt components bridge the trinuclear cluster {Cd3} to form a [Cd 12 (npd) 12 (tpt)4(H2O)2], the three-dimensional metal-organic framework {Cd3}-MOF can be simplified into a 3,7-connected two-node topological network. In addition, in {Cd3}-MOF, there are two different tunnels, A and B, with cross-sectional dimensions of and The porosity of {Cd3}-MOF calculated by Platon is 22.6%.

[0010] Furthermore, the {Cd3}-MOF hybrid material is prepared by a solvothermal synthesis method using H2npd, tpt, Cd(NO3)2·4H2O and HNO3 as raw materials and a mixed solution of acetonitrile and water as a solvent.

[0011] Furthermore, the preparation method specifically comprises the following steps:

[0012] (1) Mixing the above raw materials and solvent to form a reaction system, and placing it in a sealed container; the molar ratio of the raw materials H2npd, tpt, Cd(NO3)2·4H2O and HNO3 is 1:1:2:1.4-7.0; the volume ratio of the solvent acetonitrile and water is 1-9:9-1;

[0013] (2) The reaction system is stirred at room temperature for 10 to 30 minutes, and then the reaction temperature is raised to 100 to 160°C and reacted for 3 to 5 days, followed by natural cooling, filtration, and drying to obtain block crystals.

[0014] Furthermore, the molar ratio of H2npd, tpt, Cd(NO3)2·4H2O and HNO3 in step (1) is 1:1:2:3.5.

[0015] Furthermore, the initial molar concentration of H2npd in the reaction system is 5 mmol / L.

[0016] Furthermore, the reaction temperature in step (2) is 120° C., and the drying refers to washing the crystals with distilled water and then drying them naturally in air at room temperature.

[0017] The {Cd3}-MOF hybrid material containing multiple trinuclear clusters prepared by the above method is used in the preparation of hybrid light-emitting diodes HLED and composite fluorescent materials. The prepared HLED can emit tunable white light that changes with the current intensity during operation, and the white light wavelength covers the visible light band of 400-760nm.

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

[0019] (1) The {Cd3}-MOF hybrid material containing multiple trinuclear clusters prepared by the present invention is a crystalline MOF hybrid material synthesized by coordination bond drive. In its crystal structure, the trinuclear cluster {Cd3} can be simplified to 7 connected nodes, and the organic component npd 2- and tpt components bridge the trinuclear cluster {Cd3} to form a [Cd 12 (npd) 12 The three-dimensional metal-organic framework {Cd3}-MOF, based on a novel (tpt)4(H2O)2] structure, exhibits a 3,7-connected, two-node topological network. Two distinct tunnels, A and B, exist within {Cd3}-MOF. The porosity of {Cd3}-MOF is calculated by Platon to be 22.6%. These structural features provide a model for the development of novel crystalline luminescent materials.

[0020] (2) The {Cd3}-MOF hybrid material containing multiple trinuclear clusters prepared by the present invention has readily available organic raw materials and metal salts, does not require rare earth raw materials, has mild experimental conditions, is simple to operate, has an experimental yield of approximately 75%, has high phase purity, and has good thermal stability.

[0021] (3) The {Cd3}-MOF hybrid material provided by the present invention, as a single-component phosphor, was packaged into a 1W violet LED chip via electro-optical technology to produce a novel hybrid light-emitting diode (HLED). Driven at a certain power, the HLED emitted adjustable white light with varying input current strength. The wavelength of the emitted white light ranged from 400 to 760 nm, covering the visible light region. The HLED parameters revealed that the {Cd3}-MOF hybrid material provided by the present invention is a novel fluorescent material with potential application prospects in the LED field. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the X-ray powder diffraction pattern of the {Cd3}-MOF hybrid material of the present invention;

[0023] Figure 2 This is a thermogravimetric curve of the {Cd3}-MOF hybrid material of the present invention;

[0024] Figure 3 This is the infrared spectrum of the {Cd3}-MOF hybrid material of the present invention;

[0025] Figure 4 The {Cd3}-MOF hybrid material Cd 2+ Four coordination modes of ions (a) and the crystal structure of the trinuclear cluster {Cd3} (b);

[0026] Figure 5 The crystal structure diagram of the {Cd3}-MOF hybrid material of the present invention;

[0027] Figure 6 This is the solid-state fluorescence spectrum of the {Cd3}-MOF hybrid material of the present invention;

[0028] Figure 7 The luminescence spectrum, chromaticity coordinates, and photos of the HLED encapsulated with the {Cd3}-MOF hybrid material of the present invention before and after luminescence are shown.

[0029] Figure 8 This is a relationship diagram of the light color parameters of the HLED encapsulated by the {Cd3}-MOF hybrid material of the present invention as a function of current intensity. DETAILED DESCRIPTION

[0030] The present invention is described in detail below with reference to specific embodiments and accompanying drawings. The present invention performs single crystal X-ray diffraction tests on the crystalline products of {Cd3}-MOF hybrid materials containing various trinuclear clusters to analyze their precise electronic structures; and performs a series of characterizations on the final products, such as powder X-ray diffraction, infrared, and thermogravimetric analysis, to determine that their chemical composition formula is {[Cd 12 (npd) 12 (tpt)4(H2O)2](H2O) 10} n The yield is calculated based on the amount of H2npd used, that is, the amount of npd in the product composition. 2- The yield is the ratio of the theoretically obtained mass of the compound to the actual mass of the product obtained. In this invention, the Chinese chemical name of H2npd is 1,4-naphthalenedicarboxylic acid, and the Chinese name of the component TPT is 2,4,6-tris(4-pyridyl)-1,3,5-triazine.

[0031] 1. Preparation of {Cd3}-MOF hybrid materials containing various trinuclear clusters of the present invention

[0032] Example 1

[0033] The following materials were prepared by mass or volume: H₂npd (10.8 mg, 0.05 mmol), tpt (15.6 mg, 0.05 mmol), Cd(NO₃)₂·4H₂O (30.8 mg, 0.1 mmol), CH₃CN (9 mL), H₂O (1 mL), and HNO₃ solution (7 mol / L, 25 μL, 0.175 mmol). The molar ratio of H₂npd:tpt:Cd(NO₃)₂·4H₂O:HNO₃ was 1:1:2:3.5. These materials were placed in a 25 mL polytetrafluoroethylene-lined container and stirred for approximately 30 minutes. The container was then sealed in a stainless steel reactor and heated to 120°C in an electric forced-air oven. After a constant temperature reaction for 3 days, the reaction was allowed to cool naturally to room temperature to obtain a bulk crystal sample. This crystal was filtered from the mother liquor, washed with distilled water, and air-dried at room temperature.

[0034] The prepared crystal samples were subjected to powder diffraction tests using a Shimadzu XRD-6100 X-ray diffractometer (see Figure 1 , horizontal axis - angle; vertical axis - diffraction intensity), the peaks of the test spectrum and the peaks of the crystal structure simulation spectrum (software Mercury) can match well, indicating that the structure of the obtained crystalline sample is the same as the structure obtained from the single crystal data, indicating that the sample phase purity is high.

[0035] Thermogravimetric analysis of the obtained crystallized samples showed that (see Figure 2 , nitrogen atmosphere, horizontal axis - temperature; vertical axis - residue), from Figure 2 It can be seen that the crystal sample of the porous MOF hybrid material loses 3.45% of its weight before 70°C, and almost all the guest water molecules are released (theoretical calculation value is 3.34%); at 280°C, it loses 4.11% of its weight, and almost all the guest water molecules and coordinated water molecules are released (theoretical calculation value is 4.01%). Data analysis shows that the obtained MOF hybrid material has high thermal stability. The infrared spectrum of the sample is at 3364cm -1 Absorption near the α-Cd3-Hydroxy-MoF hybrid indicates the presence of hydroxyl groups or molecules in the structure. Significant weight loss after 360°C may be due to skeleton collapse or decomposition. This demonstrates that the porous {Cd3}-MOF hybrid prepared in this invention has good thermal stability.

[0036] Determination of single crystal structure: Select appropriate single crystals and perform diffractometry on a SMARTAPEX II single crystal diffractometer (Mo-Ka, Graphite monochromator), X-ray diffraction data were collected at low temperature of 100(2)K and corrected by Lp factor. The crystal structure was solved by direct method, and the structure analysis and refinement were completed by SHELXTL-97 program package, and then the full matrix least squares method F was used. 2Anisotropic refinement was performed on all non-hydrogen atoms. Hydrogen atomic coordinates of the organic ligands were obtained by theoretical hydrogenation. Key crystallographic data are shown in Table 1; coordination bond lengths are shown in Table 2.

[0037] Table 1 Main crystallographic data

[0038]

[0039] *R1=Σ||F o |-|F c || / Σ|F o |,wR2=[Σ w (F o 2 -F c 2 ) 2 / Σ w (F o 2 ) 2 ] 1 / 2

[0040] Table 2 Some coordination bond lengths

[0041]

[0042] Based on the above characterization data, the general formula of the prepared {Cd3}-MOF hybrid materials containing various trinuclear clusters is {[Cd 12 (npd) 12 (tpt)4(H2O)2](H2O) 10} n , the structural unit chemical formula is C 216 H 144 N 24 O 60 Cd 12 The chemical formula weight is 5384.43, wherein the elemental analysis calculated value (%) is: C 48.18, H 2.70, N 6.26, Cd 25.05; CHN actual measured value (%) is: C 48.14, H 2.67, N 6.24. Figure 3 The infrared spectrum of the new substance of the present invention (abscissa - wave number; ordinate - transmittance). FT-IR (KBr, cm -1): 3364(w), 3066(w), 1520(vs), 1448(m), 1350(s), 1253(m), 1052(m), 838(s), 788(s), 653(s), 580(w). Note: Elemental analysis values ​​were obtained using a Perkin-Elmer 2400 elemental analyzer; infrared spectra were obtained using a Perkin-Elmer FT-IR Spectrometer with a KBr base at 400-4000 cm -1 Measured within the range.

[0043] The single crystal X-ray diffraction data is analyzed to obtain the precise microscopic electronic structure, i.e. the crystal structure. In the asymmetric unit of the crystal structure of the {Cd3}-MOF hybrid material, there are 12 crystallographically independent Cd 2+ ions, 12 npd 2- , 4 tpt, 2 coordinated water molecules and 10 lattice water molecules. Figure 4 As shown in a, the organic component npd 2- Four coordination modes were adopted, bridging two Cd 2+ ions or 3 Cd 2+ ions or 4 Cd 2+ ions; Cd 2+ Among the coordination numbers of ions, Cd2, Cd3, Cd5, and Cd11 have a coordination number of 7, and the rest of Cd 2+ The coordination number of the ion is 6; the bond lengths of Cd-O and Cd-N range from Organic component npd 2- The coordination modes of tpt and tpt are shown in formula III to VII, where M represents metal Cd 2+ ions; Cd 2+ Four different trinuclear clusters {Cd3}( Figure 4 b), the coordination mode is shown in formula VIII to XI, and its composition, Cd(II) internuclear distance The parameters of the angle between the nuclei (°) are shown in Table 3.

[0044] Table 3 Composition and internuclear distance of the trinuclear cluster {Cd3} Angle between nuclei (°)

[0045]

[0046] like Figure 5 As shown, in the spatial structure of {Cd3}-MOF hybrid materials, there is a π…π interaction between the aromatic rings of the [Cd3(tpt)] structural unit, and the interplanar spacing Then form supramolecular chain [Cd3(tpt)] nThe above three-core cluster {Cd3} can be simplified into 7-connected nodes, and the organic component npd 2- and tpt components bridge the trinuclear cluster {Cd3} to form a [Cd 12 (npd) 12 The three-dimensional metal-organic framework {Cd3}-MOF with (tpt)4(H2O)2] can be simplified into a 3,7-connected two-node topological network. In {Cd3}-MOF, there are two different tunnels, A and B, with cross-sectional dimensions of and The porosity of {Cd3}-MOF calculated by Platon is 22.6%.

[0047] At room temperature, the fluorescence spectrum of the {Cd3}-MOF hybrid material was tested ( Figure 6 Spectral data analysis shows that the fluorescence emission wavelength is broadly distributed over a range of 490-800 nm, with a peak at 580 nm and strong shoulder peaks at 522 nm and 547 nm, indicating that the emitted fluorescence is yellow-green. Excitation wavelengths range from 315-500 nm, with fluorescence being generated at 404 nm, 422 nm, and 467 nm.

[0048] This example was repeated several times, and the actual mass of the obtained {Cd3}-MOF hybrid material was maintained at 13.9-16.9 mg, and the yield calculated based on H2npd was 62.0%-75.3%.

[0049] Example 2

[0050] The following materials were prepared by mass or volume: H₂npd (10.8 mg, 0.05 mmol), tpt (15.6 mg, 0.05 mmol), Cd(NO₃)₂·4H₂O (30.8 mg, 0.1 mmol), CH₃CN (1 mL), H₂O (9 mL), and HNO₃ solution (7 mol / L, 50 μL, 0.35 mmol). The molar ratio of H₂npd:tpt:Cd(NO₃)₂·4H₂O:HNO₃ was 1:1:2:7. These materials were placed in a 25 mL polytetrafluoroethylene-lined container and stirred for approximately 30 minutes. The container was then sealed in a stainless steel reactor and heated to 100°C in an electric forced-air oven. After a constant temperature reaction for 5 days, the reaction was allowed to cool naturally to room temperature. A bulk crystal sample was filtered from the mother liquor, washed with distilled water, and air-dried at room temperature.

[0051] The product was characterized by powder X-ray diffraction (see Figure 1 ), the data obtained are similar to those in Example 1. This indicates that the crystal structure of the sample prepared in Example 2 has not changed and the sample has high phase purity.

[0052] This example was repeated several times, and the actual mass of the obtained {Cd3}-MOF hybrid material was maintained at 12.1-13.5 mg, and the yield calculated based on H2npd was 53.9%-60.2%.

[0053] Example 3

[0054] The following materials were prepared by mass or volume: H₂npd (10.8 mg, 0.05 mmol), tpt (15.6 mg, 0.05 mmol), Cd(NO₃)₂·4H₂O (30.8 mg, 0.1 mmol), CH₃CN (7 mL), H₂O (3 mL), and HNO₃ solution (7 mol / L, 10 μL, 0.07 mmol). The molar ratio of H₂npd:tpt:Cd(NO₃)₂·4H₂O:HNO₃ was 1:1:2:1.4. These materials were placed in a 25 mL polytetrafluoroethylene-lined container and stirred for approximately 10 minutes. The container was then sealed in a stainless steel reactor and heated to 160°C in an electric forced-air oven. After a constant temperature reaction for 3 days, the reaction was allowed to cool naturally to room temperature. A bulk crystal sample was obtained, filtered from the mother liquor, washed with distilled water, and air-dried at room temperature.

[0055] The product was characterized by powder X-ray diffraction (see Figure 1 ), the data obtained are similar to those in Example 1. This indicates that the crystal structure of the sample prepared in Example 3 has not changed and the sample phase purity is high.

[0056] This example was repeated several times, and the actual mass of the obtained {Cd3}-MOF hybrid material was maintained at 13.1-15.2 mg, and the yield calculated based on H2npd was 58.4%-67.8%.

[0057] 2. Preliminary application of the {Cd3}-MOF hybrid material of the present invention

[0058] Example 4 Preparation of Tunable White Light HLED Device

[0059] In the experiment, a standard capped violet LED chip with a power of approximately 1W was used for packaging. The {Cd3}-MOF hybrid material was ground into a single-component ordered hybrid phosphor and encapsulated onto the LED chip. After curing for 72 hours, a hybrid light-emitting diode (HLED) capable of emitting white light was obtained.

[0060] The luminescence spectrum of the device was tested at a steady current of 30mA (voltage 3V). Figure 7The following are the emission spectrum, chromaticity coordinates, and photos of the HLED device before and after operation (horizontally—wavelength, vertically—intensity). Data analysis shows that the device emits a correlated color temperature of 7272K, a color rendering index (CRI Ra) of 65.0, and a dominant wavelength of 511.3nm. Photos of the device in operation reveal a slightly greenish white light. In the CIE 1931 chromaticity diagram, the spectral data corresponds to color coordinates (0.2917, 0.3604), which lean toward the green region; therefore, the actual light color is consistent with the color indicated by the coordinates. The spectrum shows an emission wavelength range of 400-760nm, essentially covering the entire visible light region.

[0061] Experimental studies have found that by controlling the current intensity and driving the device with a current of 10 to 30 mA, the relative intensity of green light in the normalized spectrum of white light emitted by the device gradually decreases, and the correlated color temperature increases from 5536K [chromaticity coordinates (0.3318, 0.4081)] to 7272K [chromaticity coordinates (0.2917, 0.3604)]. Figure 8 As shown in Figure 2, analysing relative intensity changes, as the driving current increases, the relative intensity of green light in the 500-570nm band decreases, while the relative intensity of blue-violet light in the 400-450nm band increases, and the white light gradually becomes cooler. This tunable property is likely determined by the structure and properties of the light conversion layer, and this property also gives this tunable white light hybrid device a wider range of potential applications.

[0062] Data from the preliminary preparation of tunable white light HLED devices show that the calculated metal element content of the light-conversion layer made from the {Cd3}-MOF hybrid material in the present invention is approximately 25%, which is much lower than the number of metal element types and total content in inorganic phosphors. Therefore, the fluorescent hybrid material of the present invention not only saves rare earth resources but is also more environmentally friendly, providing experimental reference data for the development of new non-rare earth single-component fluorescent materials.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A {Cd3}-MOF hybrid material containing multiple trinuclear clusters, characterized in that: Its general chemical formula is {[Cd 12 (npd) 12 (tpt)4(H2O)2](H2O) 10 } n , belongs to the triclinic system, and the space group is Unit cell parameters In the chemical formula, component npd 2- It is obtained by removing two protons from an organic carboxylic acid H2npd. The structure of the component H2npd is shown in Formula I; the structure of the component tpt is shown in Formula II.

2. The {Cd3}-MOF hybrid material containing multiple trinuclear clusters according to claim 1, characterized in that The asymmetric unit of the crystal structure of the {Cd3}-MOF hybrid material contains 12 crystallographically independent Cd 2+ ions, 12 npd 2- , 4 tpt components, 2 coordinated water molecules and 10 lattice water molecules; the organic component npd 2- Four coordination modes are adopted to bridge two Cd 2+ ions or 3 Cd 2+ ions or 4 Cd 2+ ions; Cd 2+ Among the coordination numbers of ions, Cd2, Cd3, Cd5, and Cd11 have a coordination number of 7, and the rest of Cd 2+ The coordination number of the ion is 6; the bond lengths of Cd-O and Cd-N range from Carboxylate, pyridinic N and water molecules form four different trinuclear clusters {Cd3}; the organic component npd 2- The coordination modes of tpt and tpt are shown in formula III to VII, where M represents metal Cd 2+ ions; Cd 2+ The coordination patterns are shown in formulas VIII to XI, and the numbers on the right side of the element symbols represent the atom numbers in the asymmetric unit.

3. The {Cd3}-MOF hybrid material containing multiple trinuclear clusters according to claim 2, characterized in that: In the spatial structure of the {Cd3}-MOF hybrid material, there is a π…π interaction between the aromatic rings of the [Cd3(tpt)] structural unit, and the interplanar spacing is Then form supramolecular chain [Cd3(tpt)] n The above three-core cluster {Cd3} can be simplified into 7-connected nodes, and the organic component npd 2- and tpt components bridge the trinuclear cluster {Cd3} to form a [Cd 12 (npd) 12 (tpt)4(H2O)2], a three-dimensional metal-organic framework {Cd3}-MOF, can be simplified into a 3,7-connected two-node topological network.

4. A method for preparing a {Cd3}-MOF hybrid material containing multiple trinuclear clusters according to any one of claims 1 to 3, characterized in that: The {Cd3}-MOF hybrid material is prepared by a solvothermal synthesis method using H2npd, TPT, Cd(NO3)2·4H2O and HNO3 as raw materials and a mixed solution of acetonitrile and water as a solvent.

5. The method for preparing a {Cd3}-MOF hybrid material containing multiple trinuclear clusters according to claim 4, characterized in that: The preparation method specifically comprises the following steps: (1) Mixing the above raw materials and solvent to form a reaction system, and placing it in a sealed container; the molar ratio of the raw materials H2npd, tpt, Cd(NO3)2·4H2O and HNO3 is 1:1:2:1.4-7.0; the volume ratio of the solvent acetonitrile and water is 1-9:1-9; (2) The reaction system is stirred at room temperature for 10 to 30 minutes, and then the reaction temperature is raised to 100 to 160°C and reacted for 3 to 5 days, followed by natural cooling, filtration, and drying to obtain block crystals.

6. The method for preparing a {Cd3}-MOF hybrid material containing multiple trinuclear clusters according to claim 5, characterized in that: The molar ratio of H2npd, tpt, Cd(NO3)2·4H2O and HNO3 in step (1) is 1:1:2:3.

5.

7. The method for preparing a {Cd3}-MOF hybrid material containing multiple trinuclear clusters according to claim 5, characterized in that: The initial molar concentration of H2npd in the reaction system was 5 mmol / L.

8. The method for preparing a {Cd3}-MOF hybrid material containing multiple trinuclear clusters according to claim 5, characterized in that: The reaction temperature in step (2) is 120° C., and the drying refers to washing the crystals with distilled water and then drying them naturally in air at room temperature.

9. Application of a {Cd3}-MOF hybrid material containing multiple trinuclear clusters, characterized in that: The use of the {Cd3}-MOF hybrid material prepared by the method described in any one of claims 4 to 8 in the preparation of HLED, the prepared hybrid light-emitting diode HLED can emit tunable white light that changes with the current intensity during operation, and the white light wavelength covers the visible light band of 400-760nm.

10. Application of a {Cd3}-MOF hybrid material containing multiple trinuclear clusters, characterized in that: Use of the {Cd3}-MOF hybrid material prepared by the method according to any one of claims 4 to 8 in the preparation of composite fluorescent materials.

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