Large-scale preparation method of pyrazolyl copper trinuclear single crystal

Abstract

The embodiment of the invention discloses a large-scale preparation method of pyrazolyl copper trinuclear single crystals, relates to the technical field of preparation and synthesis of metal-organic complex materials, and aims to develop a method for efficiently synthesizing pyrazolyl cyclic trinuclear copper single crystals in a large scale. The large-scale preparation method of the pyrazolyl copper trinuclear single crystal comprises the following steps: putting a pyrazolyl ligand, copper acetate monohydrate and ethanol into a hydrothermal reaction kettle according to a preset proportion, carrying out ultrasonic dissolution, and then putting into a drying oven at 120-150 DEG C for reaction; and after the reaction is finished, sequentially carrying out filtering treatment, washing treatment and drying treatment to obtain a white single crystal product, namely the pyrazolyl copper trinuclear single crystal.

Description

Technical Field

[0001] This application relates to the technical field of the preparation and synthesis of metal-organic complex materials, and specifically relates to a method for the large-scale preparation of pyrazolyl copper trinuclear single crystals. Background Art

[0002] Pyrazolyl trinuclear copper (CuCTC) is an important member of the cyclic trinuclear coinage metal-organic complex family. Such complexes have unique structures and properties. Their close intra-ring triangular metal-metal distances, nearly planar configurations, and the characteristics that the ligands and metal clusters are easy to synthesize and modify make them widely studied and applied in the fields of chemistry, materials, chemical engineering, biology, medicine, etc.

[0003] In recent years, the research on CuCTC has covered a wide range of fields from basic theory to innovative applications. Among them, the single crystal of CuCTC has always been an active research direction in the long-term study of copper-based metal M(I)-M(I) interactions. Moreover, various non-covalent interactions inside CuCTC endow it with rich properties such as luminescence and carrier transport, thus opening up broad potential application prospects, including photoluminescence imaging, reversible chemisorption / desorption of ethylene gas, industrial catalytic synthesis of paraffin alkynes, etc. These application scenarios have extremely high demands for the usage amount of CuCTC.

[0004] The existing CuCTC synthesis methods reported in the literature mainly include solid-solid reaction method and solvothermal method.

[0005] In 1990, James Trotter et al. first synthesized CuCTC by the solid-solid reaction method. In this method, copper hydroxide and ligands were directly mixed and reacted under nitrogen protection at 130 °C for 10 days. After the reaction, acetone was used to wash away the excess ligands. The resulting product was mainly brown CuCTC polymer, and only a small amount of colorless single crystals could be obtained by manual selection. Although the crude product yield could reach 60%, this method had the following obvious defects: (1) strict nitrogen protection was required; (2) the reaction cycle was as long as 10 days; (3) the single crystal content in the product was low and manual sorting was needed; (4) it was difficult to achieve large-scale preparation. These factors severely restricted the practical application value of this method. In 2000, H.V. Rasika Dias et al. developed a solvothermal method for synthesizing CuCTC. This method used cuprous oxide and ligands as raw materials, reacted in benzene solvent at 50 °C - 60 °C for 48 hours, and after filtration and washing with diatomite, vacuum distillation was carried out to obtain a colorless solid (yield 77%). To obtain high-quality single crystals, recrystallization purification in n-hexane was also required. This method had the following deficiencies: (1) toxic organic solvents such as benzene and n-hexane had to be used; (2) single crystals could only be obtained through the recrystallization step; (3) the solvent cost was relatively high; (4) the overall process was complex and not conducive to large-scale production. In 2004, Mohammad A. Omary and H.V. Rasika Dias et al. improved the solvothermal method. They introduced a high-temperature vacuum sublimation step at 245 °C after the reaction and successfully obtained high-purity single crystal products. However, this improved method still had obvious limitations: (1) the high-temperature vacuum sublimation process was complex and difficult to operate; (2) high requirements for equipment were needed; (3) it was difficult to achieve large-scale production; (4) the energy consumption was relatively large. In 2006, Dan Li and Xiao-Chun Huang et al. developed an improved solvothermal synthesis. This method used copper nitrate and ligands to react in a mixed solvent of methanol / ammonia water, sealed the mixture in a reaction kettle, and reacted at 180 °C for 80 hours, with a yield of up to 70%. Compared with the previous work, the main advantages of this method were: (1) high-purity single crystals could be directly obtained without manual screening; (2) the use of toxic organic solvents was avoided. But this method still had the following deficiencies: (1) the reaction temperature was as high as 180 °C; (2) the reaction time was as long as 80 hours; (3) two reagents, methanol and ammonia water, had to be used at the same time. These existing CuCTC synthesis methods often could only prepare single crystal products in milligram amounts, and had problems such as complex operations, relatively high reaction temperatures, long reaction times, and the need to use toxic reagents. These all restricted the preparation yield of CuCTC and further limited the wide application and in-depth research of CuCTC in more fields.

[0006] Therefore, it is of great significance to develop a method for efficiently synthesizing pyrazolyl cyclotrinuclear copper single crystals in large quantities. Summary of the Invention

[0007] The main object of the present application is to provide a method for mass preparation of pyrazolyl copper trinuclear single crystals, aiming to develop a method for efficiently and massively synthesizing pyrazolyl ring trinuclear copper single crystals.

[0008] To achieve the above object, the technical solution adopted in the embodiments of the present application is as follows: A method for mass preparation of pyrazolyl copper trinuclear single crystals, comprising the following steps:

[0009] Load a pyrazolyl ligand, copper acetate monohydrate and ethanol into a hydrothermal reaction kettle according to a preset ratio, perform ultrasonic dissolution, and then place it in an oven at 120°C - 150°C for reaction;

[0010] After the reaction is completed, perform filtration treatment, washing treatment and drying treatment in sequence to obtain a white single crystal product, which is the pyrazolyl copper trinuclear single crystal.

[0011] As some alternative embodiments of the present application, the preset ratio is: 15 mmol - 20 mmol pyrazolyl ligand: 15 mmol - 20 mmol copper acetate monohydrate: 150 ml - 200 ml ethanol.

[0012] As some alternative embodiments of the present application, the preset ratio is: 16 mmol - 18 mmol pyrazolyl ligand: 16 mmol - 18 mmol copper acetate monohydrate: 150 ml - 180 ml ethanol.

[0013] As some alternative embodiments of the present application, the preset ratio is: 17 mmol pyrazolyl ligand: 17 mmol copper acetate monohydrate: 160 ml ethanol.

[0014] As some alternative embodiments of the present application, the reaction time for placing it in an oven at 120°C - 150°C for reaction is 50 h - 75 h, preferably 65 h - 75 h.

[0015] On the other hand, the embodiments of the present application provide: A pyrazolyl copper trinuclear single crystal obtained by the method described in any one of the above.

[0016] As some alternative embodiments of the present application, the general structural formula of the pyrazolyl copper trinuclear single crystal is as follows:

[0017]

[0018] Among them, R1, R2 and R3 are all substituents;

[0019] The substituents include at least one of a hydrogen atom, a hydrocarbon group, an aromatic group, a halogen and a trifluoromethyl group.

[0020] As some alternative embodiments of the present application, the pyrazolyl copper trinuclear single crystal is (Me-Me)Pz-Cu, and its structural formula is shown as follows:

[0021]

[0022] As some alternative embodiments of the present application, the pyrazolyl copper trinuclear single crystal is (Br-Me)Pz-Cu, and its structural formula is shown as follows:

[0023]

[0024] As some alternative embodiments of the present application, the pyrazolyl copper trinuclear single crystal is (I-Me)Pz-Cu, and its structural formula is shown as follows:

[0025]

[0026] Compared with the prior art, the present application discloses a method for mass preparation of pyrazolyl copper trinuclear single crystals, that is: loading a pyrazolyl ligand, copper acetate monohydrate and ethanol into a hydrothermal reaction kettle according to a preset ratio, ultrasonically dissolving them, and then putting them into an oven at 120°C - 150°C for reaction; after the reaction is completed, filtering, washing and drying treatments are carried out in sequence to obtain a white single crystal product, which is the pyrazolyl copper trinuclear single crystal. This preparation method has the advantages of large yield, high productivity, simple synthesis method, environmentally friendly reagents, relatively low temperature, etc. The yield of more than grams can be obtained in a single reaction. The obtained product is a high-quality single crystal, which has more excellent crystal structure information and better luminescence performance compared with the powder. Description of the Drawings

[0027] Figure 1 For the structural formula and corresponding abbreviated name of representative CuCTC;

[0028] Figure 2 For the microscope photo of the CuCTC single crystal obtained in the example of the present application. Among them, the obtained CuCTC product is a large or fibrous single crystal. The internal scale is 500μm (photographing conditions: fluorescence microscope, equipped with a 5× objective lens and a 10× eyepiece);

[0029] Figure 3 For the single synthesis yield of a single hydrothermal reaction kettle. Taking (Me-Me)Pz-Cu as an example, the single yield is as high as 2.3 g, and the productivity is as high as 87% (calculated based on copper element);

[0030] Figure 4X-ray powder diffraction pattern of CuCTC involved in the embodiments of this application; the simulated and synthesized subfigure a represents the X-ray powder diffraction pattern of (Me-Me)Pz-Cu, subfigure b represents the X-ray powder diffraction pattern of (Br-Me)Pz-Cu, subfigure c represents the X-ray powder diffraction pattern of (Br-Br)Pz-Cu, subfigure d represents the X-ray powder diffraction pattern of (Br-Br-Br)Pz-Cu, and subfigure e represents the X-ray powder diffraction pattern of (I-Me)Pz-Cu;

[0031] Figure 5 Photoluminescence excitation spectrum and emission spectrum of CuCTC involved in the embodiments of this application; Figure 6 Comparison of photoluminescence properties of CuCTC involved in the embodiments of this application; subfigure a represents the normalized emission spectrum, λ ex = 310 nm; subfigure b represents the normalized excitation spectrum, and the λ of (Me-Me)Pz-Cu, (Br-Me)Pz-Cu, and (Br-Br)Pz-Cu em are 625 nm, 635 nm, and 625 nm respectively; subfigure c represents the CIE color coordinates;

[0032] Figure 7 Photoluminescence lifetime decay spectrum of CuCTC involved in the embodiments of this application;

[0033] Figure 8 Photoluminescence quantum yield of CuCTC involved in the embodiments of this application; subfigure a represents (Me-Me)Pz-Cu; subfigure b represents (Br-Br)Pz-Cu; subfigure c represents (Br-Br)Pz-Cu;

[0034] Figure 9 Absorption coefficient and attenuation efficiency diagram of CuCTC involved in the embodiments of this application; subfigure a represents the absorption coefficient diagram; subfigure b represents the relationship between attenuation efficiency and thickness; X-ray radiation is generated by a metal tungsten target, and the excitation energy is 8 keV;

[0035] Figure 10 Radioluminescence characterization of CuCTC involved in the embodiments of this application; among them, subfigure a represents the photos of solid CuCTC under natural light, ultraviolet light, and X-rays; subfigure b represents the RL spectrum of CuCTC; subfigure c represents the comparison of light yields between CuCTC and commercial scintillators; subfigure d represents the stability evaluation of RL intensity (X-ray dose rate is 705 μGy air / s, lasting for 30 minutes); subfigure e represents the linear fitting of X-ray dose rate and RL intensity; subfigure f represents the comparison of photoluminescence quantum yield and light yield of CuCTC;

[0036] Figure 11This is the radioluminescence spectrum obtained by CuCTC and the commercial scintillator lutetium aluminum garnet doped with cerium (LuAG(Ce)) under the same measurement conditions. Among them, by comparing the emission peak area of CuCTC with that of LuAG(Ce), the light yields of (Me-Me)Pz-Cu, (Br-Me)Pz-Cu, (Br-Br)Pz-Cu, (Br-Br-Br)Pz-Cu, and (I-Me)Pz-Cu can be calculated to be 70475 photons / MeV, 31257 photons / MeV, 23761 photons / MeV, 1635 photons / MeV, and 8155 photons / MeV respectively. X-ray tube parameters: tungsten target, 50 kV, 20 μA; sample thickness 1 mm;

[0037] Figure 12 This is the RL data graph under different X-ray dose rates involved in the embodiments of this application; sub-graph a represents (Me-Me)Pz-Cu; sub-graph b represents (Br-Me)Pz-Cu; sub-graph c represents (Br-Br)Pz-Cu;

[0038] Figure 13 This is the linear regression curve of X-ray dose rate and RL intensity involved in the embodiments of this application; sub-graph a represents (Me-Me)Pz-Cu; sub-graph b represents (Br-Me)Pz-Cu; sub-graph c represents (Br-Br)Pz-Cu;

[0039] Figure 14 This is a photo of the (Me-Me)Pz-Cu scintillator screen involved in the embodiments of this application;

[0040] Figure 15 This is the dynamic X-ray imaging based on the CuCTC scintillator screen involved in the embodiments of this application; among them, sub-graph a represents a photo of the (Me-Me)Pz-Cu scintillator screen under ultraviolet light (254 nm) and a schematic diagram of a self-made X-ray imaging system; sub-graphs b - e respectively represent the bright field (upper) and X-ray (lower) images of (b) a cross-body bag, (c) a pill encapsulated with a metal spring, (d) a crab, and (e) a resolution standard ruler; sub-graph f represents the simulation of real-time angiography using the (Me-Me)Pz-Cu scintillator screen; sub-graph g represents the stability evaluation of the (Me-Me)Pz-Cu scintillator screen under X-ray (dose rate: 705 μGy air / s); sub-graph h represents the comprehensive performance evaluation of CuCTC;

[0041] Figure 16 This is the X-ray spatial resolution MTF distribution of the (Me-Me)Pz-Cu scintillator screen involved in the embodiments of this application;

[0042] Figure 17Schematic diagram of the synthesis reaction involved in the preparation method described in the embodiments of the present application. Detailed implementation manners

[0043] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0044] As described above, due to its strong penetration characteristics, X-ray has become an indispensable technical means in the fields of industrial non-destructive testing (such as material defect analysis), public safety inspection, and medical imaging diagnosis. As the core conversion material of X-ray detectors, scintillators can convert high-energy X-ray photons into ultraviolet / visible light signals, which can then be recognized by conventional optoelectronic sensors. Compared with complex direct detectors that need to directly achieve "X-ray - electron" conversion, the indirect detection technology based on scintillators has more significant practical advantages.

[0045] However, the current scintillator material system has significant defects. Traditional inorganic scintillators rely on high-temperature sintering processes, contain toxic heavy metal elements such as lead and cadmium, and have high manufacturing costs. On the other hand, new scintillators often have problems such as low light yield, poor environmental stability, complex synthesis processes, high costs, and residues of toxic elements, which seriously restrict their industrial applications.

[0046] Based on this, the present application proposes a series of pyrazolyl copper trinuclear metal-organic complex scintillator materials and their preparation methods. The scintillator materials obtained by the preparation method of the present application have a light yield of up to 70475 photons / MeV and a photoluminescence quantum yield of 75.62% compared with existing scintillator materials, and have good irradiation stability and relatively fast scintillation speed, and can be applied to dynamic X-ray imaging. In addition, the preparation method described in the present application synthesizes the scintillator materials in one step at 120°C - 150°C, does not involve toxic heavy metals during the preparation process, and has relatively low production costs. It can be seen that the preparation method described in the present application has great application value in scenarios such as medical CT and security detection.

[0047] When the scintillator material is used in scenarios such as medical CT and security detection, it is necessary to prepare large-area scintillation screens, and thus a large amount of scintillator materials are required. Based on this, the present application provides a method for mass-producing pyrazolyl copper trinuclear single crystals, aiming to develop an efficient, inexpensive, and mass-synthesis method for pyrazolyl copper trinuclear single crystals. The mass-production method, as Figure 17 shown, includes the following steps:

[0048] Step S10: Load the pyrazolyl ligand, copper acetate monohydrate, and ethanol into a hydrothermal reactor in a preset ratio. After ultrasonic dissolution, place it in an oven at 120°C - 150°C for reaction; preferably, the preset ratio is: 15 mmol - 20 mmol pyrazolyl ligand: 15 mmol - 20 mmol copper acetate monohydrate: 150 ml - 200 ml ethanol. More preferably, the preset ratio is: 16 mmol - 18 mmol pyrazolyl ligand: 16 mmol - 18 mmol copper acetate monohydrate: 150 ml - 180 ml ethanol. Most preferably, the preset ratio is: 17 mmol pyrazolyl ligand: 17 mmol copper acetate monohydrate: 160 ml ethanol. Preferably, the reaction time for placing it in an oven at 120°C - 150°C for reaction is 50 h - 75 h, preferably 65 h - 75 h.

[0049] Step S20: After the reaction is completed, perform filtration, washing, and drying treatments in sequence to obtain a white single-crystal product, which is a trinuclear copper pyrazolyl single crystal.

[0050] The general structural formula of the trinuclear copper pyrazolyl single crystal (which can also be called a trinuclear copper pyrazolyl ring single crystal, and the two refer to the same thing) is as follows:

[0051]

[0052] Among them, R1, R2, and R3 are all substituents; the substituents include at least one of a hydrogen atom, a hydrocarbon group, an aromatic group, a halogen, and a trifluoromethyl group.

[0053] Preferably, the trinuclear copper pyrazolyl single crystal is (Me-Me)Pz-Cu, and its structural formula is as follows:

[0054]

[0055] Preferably, the trinuclear copper pyrazolyl single crystal is (Br-Me)Pz-Cu, and its structural formula is as follows:

[0056]

[0057] Preferably, the trinuclear copper pyrazolyl single crystal is (I-Me)Pz-Cu, and its structural formula is as follows:

[0058]

[0059] As shown in the attached drawing Figure 1As shown, the obtained series of pyrazolyl copper trinuclear complexes are named (Me-Me)Pz-Cu, (Br-Me)Pz-Cu, (Br-Br)Pz-Cu, (Br-Br-Br)Pz-Cu, and (I-Me)Pz-Cu, respectively. Among them, (Br-Me)Pz-Cu and (I-Me)Pz-Cu are compounds reported for the first time, and their crystallographic data can be obtained from the Cambridge Crystallographic Data Centre, with reference numbers CCDC2417111 and 2431879, respectively.

[0060] These CuCTC single crystals can be prepared in large quantities by a simple one-pot synthesis method, using only ethanol as the solvent, ensuring operational simplicity and environmental friendliness. As Figure 2 shown, these crystalline products form bulk or needle-shaped single crystals with a diameter of approximately 100 - 400 μm. Under solid-state conditions at room temperature, ultraviolet excitation can cause CuCTC to emit bright light, exhibiting aggregation-induced emission (AIE) characteristics. Through efficient and large-scale one-pot preparation, more than 2.3 g of product can be obtained in a single reaction, with a yield as high as 87% ( Figure 3 ). The phase purity of these CuCTC was confirmed by X-ray powder diffraction patterns (PXRD) ( Figure 4 ).

[0061] Steady-state photoluminescence analysis was used to study the photophysical properties of CuCTC ( Figure 5 ). A photoluminescence spectrum with a broad emission band can be observed for CuCTC at 570 - 640 nm, and its excitation peaks are all below 350 nm ( Figure 6 ). Time-resolved photoluminescence (TRPL) analysis shows that the lifetimes of (Me-Me)Pz-Cu, (Br-Me)Pz-Cu, and (Br-Br)Pz-Cu are 40.61 μs, 29.80 μs, and 25.55 μs, respectively ( Figure 7 and Table 1). The microsecond-level lifetimes indicate phosphorescence. In addition, the photoluminescence quantum yields (PLQY) of (Me-Me)Pz-Cu, (Br-Me)Pz-Cu, and (Br-Br)Pz-Cu are 78.88%, 90.76%, and 83.69%, respectively ( Figure 8 and Table 1).

[0062] Table 1:

[0063]

[0064] On the other hand, the embodiments of the present application also provide an imaging application of the pyrazolyl copper ring trinuclear scintillator, that is, using the pyrazolyl copper ring trinuclear scintillator to prepare a scintillation screen material for X-ray imaging. Specifically, it includes: using the pyrazolyl copper ring trinuclear scintillator to prepare a scintillation screen material for medical imaging, such as using the pyrazolyl copper ring trinuclear scintillator to prepare a simulated X-ray dynamic vascular imaging scintillation screen material. Another example is using the pyrazolyl copper ring trinuclear scintillator to prepare a scintillation screen material for security detection imaging.

[0065] It should be noted that the scintillation screen material is obtained through the following steps:

[0066] Mix polymethyl methacrylate and CuCTC and add them to dichloromethane. After stirring evenly at a preset temperature, cast them on a silicone mold and air-dry to obtain a CuCTC scintillator screen. Specifically, the mixing mass ratio of the polymethyl methacrylate to the CuCTC is about 1:1; the mixing volume ratio of the dichloromethane to the polymethyl methacrylate is 5:1. The preset temperature is 35 °C, and the stirring time is 5 min - 30 min.

[0067] The light yield of the pyrazolyl copper ring trinuclear scintillator of the present application can reach 70,000 photons / MeV, and the photoluminescence quantum yield of the pyrazolyl copper ring trinuclear scintillator can reach 75.62%.

[0068] Next, the preparation process and performance testing of the pyrazolyl copper trinuclear single crystal of the present application will be elaborated in detail with specific examples:

[0069] Example 1

[0070] Synthesis of CuCTC:

[0071] (Me-Me)Pz-Cu, (Br-Me)Pz-Cu, (Br-Br)Pz-Cu, (Br-Br-Br)Pz-Cu, and (I-Me)Pz-Cu use 3,5-dimethyl-1H-pyrazole, 3-bromo-5-methyl-1H-pyrazole, 3,5-dibromo-1H-pyrazole, 3,4,5-tribromo-1H-pyrazole, and 3-iodo-5-methyl-1H-pyrazole as ligands respectively, and can be synthesized according to the existing technology.

[0072] Measurement of X-ray scintillation characteristics:

[0073] According to the XCOM database provided by the National Institute of Standards and Technology (NIST) of the United States, obtain the relationship between the total X-ray absorption coefficient and the photon energy. Use formula (1) to further calculate the attenuation efficiency (AE, %):

[0074] (1) AE = (1 - e -tρd ) × 100%

[0075] where ρ (g / cm) is the density of the scintillator and d (cm) is the thickness of the scintillator.

[0076] The X-ray light yield (LY) and detection limit (DL) were measured using a tungsten X-ray tube equipped on a fluorescence spectrometer. The LY was determined by a reference method, using a commercial LuAg(Ce) crystal as the standard scintillator. To minimize the thickness effect, all samples were prepared to have a thickness ≥ 1 mm. Both the samples and the standard scintillator were irradiated with an X-ray tube operating at a working voltage of 50 kV and a current of 20 μA. The emitted photons (P measured ) were quantified and normalized to 100% X-ray attenuation (AE) according to Equation (2):

[0077]

[0078] where AE(d) is the attenuation coefficient at the actual thickness when the photon energy is 8 keV (the peak energy of the tungsten tube). The attenuation coefficients of LuAg(Ce), (Me-Me)Pz-Cu, (Br-Me)Pz-Cu, (Br-Br)Pz-Cu, (Br-Br-Br)Pz-Cu, and (I-Me)Pz-Cu were calculated to be 100%, 97.85%, 100%, 100%, 100%, and 100%, respectively.

[0079] The light yield (LY) of the sample can be calculated by Equation (3):

[0080]

[0081] where the LY of LuAG(Ce) is 25000 photons / MeV.

[0082] The detection limit (DL) was analyzed at X-ray tube voltages of 6 - 10 kV and currents of 7 - 15 μA. The emitted photons (P measured ) were quantified by a fluorometer. The DL can be calculated using the 3σ / slope method as shown in Equation (4):

[0083]

[0084] where SD represents the standard deviation of the emission wavelength signal intensity obtained from at least 11 consecutive background noise measurements. The slope refers to the slope of the linear regression curve of the radioluminescence intensity of CuCTC versus the X-ray dose rate (slope).

[0085] For X-ray imaging, a scintillation screen (6 × 4 cm 2) After adding 500 mg of (Me-Me)Pz-Cu, the mixture was stirred to form a homogeneous suspension, poured into a silicon mold, and air-dried. X-ray imaging was performed using a self-made device equipped with a tungsten filament X-ray tube with an excitation source of 50 kV and 200 μA. Digital cameras were used for photography and video capture. The photo exposure time was 1 s, and the video frame rate was 25 frames per second. The spatial resolution of the images was quantified by the modulation transfer function (MTF), which was obtained and analyzed by software from three graphs containing I max and I min values, and the formula is shown in Equation (5).

[0086]

[0087] Based on the detection by the above method, the following conclusions can be drawn:

[0088] Radioluminescence characteristics:

[0089] With the increase in the halogen substitution amount, the X-ray absorption ability of CuCTC was significantly enhanced ( Figure 9 ). CuCTC all showed strong luminescence under X-ray excitation ( Figure 10 , subfigure a). In this application, their LY was evaluated by comparing it with the commercial scintillator LuAG(Ce) ( Figure 10 , subfigure b in and Figure 11 ). The results showed that (Me-Me)Pz-Cu, (Br-Me)Pz-Cu, (Br-Br)Pz-Cu, (I-Me)Pz-Cu, and (Br-Br-Br)Pz-Cu showed light yields of approximately 70475 photons / MeV, 31257 photons / MeV, 23761 photons / MeV, 8155 photons / MeV, and 1635 photons / MeV, respectively (Table 1). CuCTCs showed excellent photoluminescence characteristics, and their light yields were significantly better than those of traditional scintillators ( Figure 10 , subfigure c), and showed advantages such as excellent irradiation stability and low detection limit. Under continuous X-ray irradiation (total dose of 1.269 Gy), CuCTC all showed excellent stability ( Figure 10 , subfigure d). By adjusting the X-ray dose, their linear luminescence response to X-rays was confirmed ( Figure 10 , subfigure e in and Figure 12 ). According to the slope of the linear regression curve and the standard deviation of the background noise, the detection limits of (Me-Me)Pz-Cu, (Br-Me)Pz-Cu, and (Br-Br)Pz-Cu were calculated to be 0.49 μGy / s, 0.90 μGy / s, and 1.09 μGy / s, respectively ( Figure 13 and Table 2).

[0090] Table 2:

[0091]

[0092] Dynamic X-ray Imaging:

[0093] The AIE property of CuCTC makes it suitable for use as a solid-state scintillator. In this paper, polymethyl methacrylate (PMMA) was used as the polymer matrix to successfully prepare a 6×4 cm 2 Flashing screen ( Figure 14 ). Under ultraviolet light, the scintillator emits bright orange-yellow fluorescence ( Figure 15 Using a self-made X-ray imaging system ( Figure 15 (a in the figure), this application successfully demonstrated that the (Me-Me)Pz-Cu scintillator screen can efficiently and clearly reveal the internal structure of various objects under X-ray irradiation. For example, it effectively visualized the metal thermos in a shoulder bag, the hidden metal spring in a pill capsule, and the skeletal structure of a crab, highlighting its potential applications in security inspection and medical imaging ( Figure 15 The X-ray images obtained using the line pair resolution standard ruler show that the contrast boundary remains clear when the spatial resolution reaches 14.3 lp / mm ( Figure 15 By drawing the I based on the line pairs in the acquired image max and I min The modulation transfer function (MTF) distribution of the calculated values determines the spatial resolution to be 13.4lp / mm ( Figure 16 ).

[0094] Therefore, in order to verify the dynamic imaging performance of the (Me-Me)Pz-Cu scintillating screen, the present application conducted a vascular angiography simulation experiment. The experimental results show that the (Me-Me)Pz-Cu scintillating screen can record real-time video at a fast frame rate of 25 frames per second, clearly capturing the flow of the contrast agent ( Figure 15 (f in the middle). This performance is attributed to the excellent LY value and relatively short luminescence lifetime of (Me-Me)Pz-Cu, which enables bright and clear imaging even at a short frame interval of 40ms. This rapid blinking response surpasses conventional angiographic imaging in clinical applications. As a verification of long-term stability, the RL intensity of the (Me-Me)Pz-Cu scintillator screen shows negligible degradation after 200 on-off cycles ( Figure 15 These results highlight CuCTCs as a promising indirect scintillator material with excellent light yield, low detection limit and fast scintillation response. In addition, they have a simple synthesis method and extremely low cost. These advantages make CuCTCs a promising alternative to traditional commercial scintillators (Figure 15 A better alternative to the h-subgraph

[0095] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for mass preparation of a pyrazolyl copper trinuclear single crystal, characterized in that, It includes the following steps: Load the pyrazolyl ligand, copper(II) acetate monohydrate and ethanol into a hydrothermal reaction kettle according to a preset ratio, perform ultrasonic dissolution, and then place it in an oven at 120°C - 150°C for reaction; After the reaction is completed, perform filtration, washing and drying treatments in sequence to obtain a white single crystal product, which is a trinuclear copper pyrazolyl single crystal.

2. The method for mass preparation of the pyrazolyl copper trinuclear single crystal according to claim 1, wherein The preset ratio is: 15 mmol - 20 mmol pyrazolyl ligand: 15 mmol - 20 mmol copper(II) acetate monohydrate: 150 ml - 200 ml ethanol.

3. The method for mass preparation of the pyrazolyl copper trinuclear single crystal according to claim 1, wherein The preset ratio is: 16 mmol - 18 mmol pyrazolyl ligand: 16 mmol - 18 mmol copper(II) acetate monohydrate: 150 ml - 180 ml ethanol.

4. The method for large-scale preparation of the pyrazolyl copper trinuclear single crystal according to claim 1, characterized in that, The preset ratio is: 17 mmol pyrazolyl ligand: 17 mmol copper(II) acetate monohydrate: 160 ml ethanol.

5. The method for large-scale preparation of the pyrazolyl copper trinuclear single crystal according to claim 1, characterized in that, The reaction time for placing it in an oven at 120°C - 150°C for reaction is 50 h - 75 h.

6. A pyrazolyl copper trinuclear single crystal, characterized in that, Prepared by the method according to any one of claims 1 - 5.

7. The pyrazolyl copper trinuclear single crystal according to claim 6, wherein The general structural formula of the trinuclear copper pyrazolyl single crystal is as follows: Wherein, R1, R2 and R3 are all substituents; The substituents include at least one of a hydrogen atom, a hydrocarbon group, an aromatic group, a halogen and a trifluoromethyl group.

8. The pyrazolyl copper trinuclear single crystal according to claim 7, characterized in that, The trinuclear copper pyrazolyl single crystal is (Me - Me)Pz - Cu, and its structural formula is as follows:

9. The pyrazolyl copper trinuclear single crystal according to claim 7, wherein The trinuclear copper pyrazolyl single crystal is (Br - Me)Pz - Cu, and its structural formula is as follows:

10. The pyrazolyl copper trinuclear single crystal according to claim 7, characterized in that, The trinuclear copper pyrazolyl single crystal is (I - Me)Pz - Cu, and its structural formula is as follows:

Images