An X-ray luminescent material, its synthesis method and application

Abstract

This application discloses an X-ray luminescent material, its synthesis method, and its application, belonging to the field of luminescent material technology. The X-ray luminescent material is a crystalline material with the chemical formula Ca@L R MnCl4·2H2O; where, L R It is a crown ether ligand. A novel, rapid, and simple supramolecular assembly technique was used to achieve the efficient synthesis of X-ray luminescent materials. This technique significantly shortens the synthesis cycle, simplifies the operation steps, and reduces the synthesis risks by optimizing intermolecular interactions and assembly pathways, selecting specific metallic manganese, and using an acid-free, green synthesis route.

Description

Technical Field

[0001] This application relates to an X-ray luminescent material, its synthesis method, and its application, belonging to the field of luminescent material technology. Background Technology

[0002] In recent years, X-ray detection and imaging technology, with its superior performance and broad application prospects, has occupied a pivotal position in many key fields, including medical diagnosis, environmental monitoring, flaw detection technology in the defense industry, nuclear technology and radiation safety detection, and even astronomical observation. This trend has prompted researchers worldwide to explore and pay close attention to it. In this technological system, scintillator materials, as core components, have the ability to convert radiant energy into visible light. Besides traditional scintillators, metal halide perovskite materials, due to their strong X-ray absorption capacity and high photoluminescence quantum yield (PLQY), have also been applied to X-ray detection and imaging. Compared with the use of traditional small cations, based on the formation of cation complexes between crown ethers and alkali or alkaline earth metal ions through host-guest interactions, these complexes can serve as cation building blocks to form low-dimensional organic-inorganic hybrid metal halide crystalline materials. Their unique low-dimensional structural characteristics bring higher structural stability and photoluminescence quantum efficiency. Their predictable low-dimensional structure provides a basis for constructing novel supramolecular building blocks. Currently published X-ray technologies based on crown ether metal halides involve the synthesis of cuprous complexes under acidic conditions. However, cuprous complexes have poor thermal stability, limiting their practical applications. Furthermore, acidic environments significantly increase costs, safety concerns, and environmental pollution. Specifically, the hazards of acidic environments include: 1. Corrosion and Hazards: Equipment Corrosion: Acids are corrosive to reaction equipment and containers, potentially causing damage, shortened lifespan, or even leaks. Operational Hazards: Many acids are highly corrosive, irritating, or toxic, posing a threat to operator health. Improper handling during synthesis can lead to skin burns, eye damage, or inhalation of toxic gases. 2. Environmental Pollution: Waste Treatment: Acidic wastewater generated during synthesis is difficult to treat. Direct discharge into the environment can pollute water bodies, soil, and ecosystems. Gas Emissions: Some metal halides may decompose under acidic conditions to produce toxic gases, such as hydrogen chloride. The emission of these gases not only harms human health but may also pollute the atmospheric environment; 3. Increased costs: Process costs: Corrosion-resistant materials need to be selected to manufacture reaction equipment, and corresponding anti-corrosion measures need to be taken. At the same time, subsequent waste liquid needs to be treated separately, adding extra procedures; 4. Time costs: Increased pretreatment and posttreatment. Summary of the Invention

[0003] To address the limitations of existing crown ether metal halide crystalline materials, such as poor thermal stability of the complexes restricting their practical applications and the increased cost, safety, and environmental pollution caused by the acidic environment required for preparation, this application provides an X-ray luminescent material, its synthesis method, and its application. A novel, rapid, and simple supramolecular assembly technique is employed to achieve efficient synthesis of the X-ray luminescent material, utilizing manganese metal as a complex to achieve a synthesis process in an acid-free environment.

[0004] The technical solution adopted in this application is as follows:

[0005] According to one aspect of this application, an X-ray luminescent material is provided, said X-ray luminescent material being a crystalline material with the chemical formula Ca@L R MnCl4·2H2O;

[0006] Among them, L R It is a crown ether ligand.

[0007] Optionally, the crown ether ligand is selected from at least one of the supramolecular hosts with macrocyclic structures shown in formulas (1) to (12):

[0008]

[0009] The macrocyclic host exhibits flexible designability, a characteristic reflected in the precise control of host size, the diverse selection of peripheral groups, and the ingenious introduction of asymmetric substituents. These design strategies enable the macrocyclic host to be precisely matched with alkaline earth metals, thereby achieving for the first time the synthesis of organic-inorganic hybrid manganese halide X-ray luminescent materials based on crown ethers.

[0010] Crown ethers, as leading molecular building blocks, exhibit exceptional selectivity in complexing metal ions and organic cations, providing us with a powerful tool for precisely controlling supramolecular structures. This selectivity not only ensures the precision and predictability of the assembly process but also greatly enriches the diversity of the final products, highlighting the enormous potential of crown ethers in supramolecular chemistry.

[0011] According to another aspect of this application, a method for preparing the above-mentioned X-ray luminescent material is provided, comprising the following steps:

[0012] S1. Obtain crown ether ligands;

[0013] S2. Dissolve a mixture of crown ether ligands, calcium chloride, and manganese chloride in alcohol, and obtain the X-ray luminescent material after the solvent evaporates.

[0014] Previous reports on crown ether organic-inorganic hybrid materials have mostly focused on copper-based halides, and assembly typically requires an acidic environment. However, in this application, we innovatively adopted a manganese-based strategy to replace the copper-based approach, successfully achieving an acid-free assembly process. This shift not only simplifies the synthesis steps and reduces production costs but also mitigates the safety and environmental risks associated with acidic environments, making industrial production possible.

[0015] Optionally, in step S2, the molar ratio of the crown ether ligand, calcium chloride, and manganese chloride is 1:(1-2):(1-2);

[0016] Optionally, the ratio of the crown ether ligand to the alcohol is 1 mmol: 4 to 10 mL.

[0017] Optionally, in step S2, the conditions for solvent evaporation include: a temperature of 20–40°C and an evaporation time of 10–30 min.

[0018] Optionally, in step S2, the alcohol is selected from at least one of ethanol and methanol.

[0019] Optionally, in step S1, the preparation method of the crown ether ligand includes:

[0020] A mixture containing starting material, p-toluenesulfonate group material, and sodium hydroxide was dissolved in 1,4-dioxane, refluxed, filtered, and concentrated to obtain crude product.

[0021] The crude product was extracted with chloroform / saturated brine to obtain the crown ether ligand.

[0022] Optionally, the starting material is selected from at least one of (2R,2R)-2,3-butanediol and R-1,1-bi-2-naphthol.

[0023] Optionally, the p-toluenesulfonate-based raw material is selected from at least one of triethylene glycol di-p-toluenesulfonate and pentylene glycol di-p-toluenesulfonate.

[0024] Optionally, the molar ratio of the starting material, the p-toluenesulfonate-based material, and sodium hydroxide is 1:(0.5-1.5):(2-3);

[0025] Optionally, the ratio of the starting material to 1,4-dioxane is 1 mmol: 4-8 mL.

[0026] Optionally, the reflux reaction conditions include: a reaction temperature of 90–110°C and a reaction time of 48–72 h.

[0027] According to another aspect of this application, the application of the above-described X-ray luminescent material or the X-ray luminescent material prepared according to the above method in X-ray detection and imaging technology is also provided.

[0028] The beneficial effects that this application can produce include:

[0029] (1) The X-ray luminescent material provided in this application is a low-dimensional organic-inorganic hybrid metal halide crystalline material formed by the interaction between a crown ether-constructed cation module and a metal manganese halide anion through a supramolecular assembly strategy controlled by fine intermolecular forces. This material combines the flexibility of organic components with the stability of inorganic components.

[0030] (2) The synthesis process of the X-ray luminescent material provided in this application does not require the use of acid, thus improving safety and productivity. It aligns with the concepts of green chemistry and sustainable development, completely breaking the limitation that the synthesis of traditional crown ether crystal materials must rely on an acidic environment. This creates a novel acid-free synthesis route, successfully achieving rapid, simple, and efficient synthesis of X-ray luminescent materials. The synthesis process utilizes the high designability of organic ligands and the unique properties of manganese-based compounds. In particular, the innovative design of complexing crown ethers with alkaline earth metals to form a cation module greatly simplifies the synthesis process, reduces potential hazards, and improves the efficiency and safety of the synthesis. It also provides a new approach for synthesizing 0D hybrid manganese-based halides with specific optical properties.

[0031] (3) This application is the first to realize the successful application of crown ether organic-inorganic hybrid manganese-based halides in the field of X-ray luminescence. The X-ray luminescence material provided in this application, as the scintillator of the core component, can efficiently convert X-rays into visible light signals, providing more accurate and faster image information for multiple fields such as medical diagnosis, security inspection, and scientific research. Attached Figure Description

[0032] Figure 1 For the ligand L of this application R Self-assembly process and assembly Ca@L R A schematic diagram of the single crystal structure of MnCl4·2H2O.

[0033] Figure 2 For this application Ca@L R PXRD and simulated XRD of MnCl4·2H2O crystal material.

[0034] Figure 3 For this application Ca@L R Properties of MnCl4·2H2O crystal material: (a) thermogravimetric analysis curve; (b) solid UV-Vis diffuse reflectance spectrum; (c) excitation / emission spectrum; (d) fluorescence decay curve of single crystal.

[0035] Figure 4 For this application Ca@L R Emission (PL) and radiation emission (RL) spectra of MnCl4·2H2O crystal materials. Detailed Implementation

[0036] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0037] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0038] It was not further purified before use. The deuterated solvent was purchased from Adamas and Bailingwei Technology Co., Ltd.

[0039] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.

[0040] One-dimensional NMR spectroscopy was performed using a Bruker Biospin Avance III (400MHz) NMR analyzer. The chemical shift values ​​in the proton NMR spectrum were determined based on the residual peaks of the deuterated solvent. Powder X-ray diffraction was performed using a benchtop X-ray diffractometer from Kairi Gaku Corporation, Japan. The single-crystal structure was determined using a Synergy-R-Mo single-crystal diffractometer from Kairi Gaku Corporation, Japan. Optical spectroscopy was performed using an Edinburgh FS5 spectrometer, UK. Thermogravimetric analysis was conducted by Nanjing Huicheng Instrument Co., Ltd.

[0041] Example 1

[0042] Step 1: Obtaining ligand L R

[0043] As shown in the schematic diagram of the reaction process of formula (1), (2R,2R)-2,3-butanediol (7.6 g, 84 mmol), triethylene glycol di-p-toluenesulfonate (37 g, 89 mmol), and sodium hydroxide (9 g, 225 mmol) were dissolved in 500 mL of 1,4-dioxane. The mixture was refluxed at 101 °C for three days. The reaction mixture was filtered and concentrated under reduced pressure. The crude product was further purified by chloroform / saturated brine extraction to give a yellow oily product, which is the ligand L shown in formula (1). R (Yield: 32%, 4.5g, 14.06mmol).

[0044] The NMR results were as follows: 1H NMR (400MHz, CD3CN, 298K) δ=3.80-3.71(m,4H), 3.59-3.65(m,4H), 3.54-3.58(m,4H), 3.46-3.50(m,4H), 3.39-3.45(m,4H), 1.18(d,J=6.2Hz,12H).

[0045] Step 2: Ca@L R Synthesis of MnCl4·2H2O Crystal Material

[0046] like Figure 1 The reaction process is illustrated in the schematic diagram. At room temperature, the ligand L prepared in Example 1 is... R (0.5 g, 1.56 mmol) of calcium chloride (0.173 g, 1.56 mmol) and manganese chloride (0.196 g, 1.56 mmol) were dissolved in 10 mL of ethanol. After solvent evaporation at room temperature for 15 minutes, green blocky crystals were obtained, which is Ca@L R MnCl4·2H2O crystal material (yield: 75%, based on manganese chloride). Crystal structure diagram as shown below. Figure 1 As shown, PXRD and simulated XRD are as follows Figure 2 As shown.

[0047] Example 2

[0048] Steps 1 and 2 of the crystal material synthesis are the same as in Example 1, the difference being the acquisition of ligand L. R The raw materials used in the process were: (2R,2R)-2,3-butanediol was replaced with the same molar amount of R-1,1-bi-2-naphthol, and triethylene glycol di-p-toluenesulfonate was replaced with the same molar amount of pentylene glycol di-p-toluenesulfonate, to obtain ligand L. R It is a crystalline material with the structure shown in equation (2).

[0049]

[0050] Test Example 1: Ca@L R Optical testing of MnCl4·2H2O crystal materials

[0051] Ca@L prepared in Example 1 R MnCl4·2H2O is a typical example; it emits green light under ultraviolet excitation due to the tetrahedral coordination of manganese metal with halide ions. The optical properties of crystals are determined by their solid-state ultraviolet-visible diffuse reflectance spectra. Figure 3 b) Excitation / emission spectrum ( Figure 3 c), time-resolved PL spectrum ( Figure 3 d), and radiative emission spectrum ( Figure 4 Characterization, results from Figure 3 From this, we can know that Ca@L R MnCl4·2H2O exhibits good thermal stability, and its UV-Vis absorption spectrum almost perfectly matches the absorption peaks of its excitation spectrum, showing absorption in the 250-300 nm, 350-400 nm, and 400-500 nm ranges, although the intensities vary. Under UV excitation, the sample exhibits green emission centered at 528 nm, which is consistent with the characteristics of MnCl4·2H2O. 2+ Ions in Ca@L R The fluorescence decay lifetime of the sample was measured using the MnCl4·2H2O crystal field, which is related to the d→d transitions. The excitation wavelength was 375 nm, and the measured fluorescence lifetime was 1.91 ms. This ms fluorescence lifetime is related to other Mn... 2+ Compounds that emit light after an ion undergoes a d→d transition are similar. From Figure 4 It can be seen from this that under X-ray irradiation, halides Ca@L R The crystal MnCl4·2H2O emits green light. Its RL spectrum is almost identical to the emission (PL) spectrum measured by a transient spectrometer, indicating that the final emission process of X-ray scintillation is the same as the PL process.

[0052] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. An X-ray luminescent material, characterized in that, The X-ray luminescent material is a crystalline material with the chemical formula Ca@L R MnCl4·2H2O; Among them, L R It is a crown ether ligand; The crown ether ligands are selected from the supramolecular host of the macrocyclic structure shown in formula (1); 。 2. The method for preparing the X-ray luminescent material according to claim 1, characterized in that, Includes the following steps: S1. Obtain crown ether ligands; The crown ether ligands are selected from the supramolecular host of the macrocyclic structure shown in formula (1); S2. Dissolve a mixture of crown ether ligands, calcium chloride, and manganese chloride in alcohol, and obtain the X-ray luminescent material after the solvent evaporates.

3. The preparation method according to claim 2, characterized in that, In step S2, the molar ratio of the crown ether ligand, calcium chloride, and manganese chloride is 1:(1~2):(1~2).

4. The preparation method according to claim 2, characterized in that, The ratio of the crown ether ligand to the alcohol is 1 mmol: 4~10 mL.

5. The preparation method according to claim 2, characterized in that, In step S2, the conditions for solvent evaporation include: a temperature of 20~40℃ and an evaporation time of 10~30min.

6. The preparation method according to claim 2, characterized in that, In step S2, the alcohol is selected from at least one of ethanol and methanol.

7. The preparation method according to claim 2, characterized in that, In step S1, the preparation method of crown ether ligands includes: A mixture containing starting material, p-toluenesulfonate group material, and sodium hydroxide was dissolved in 1,4-dioxane, refluxed, filtered, and concentrated to obtain crude product. The crude product was extracted with chloroform / saturated brine to obtain the crown ether ligands; The starting material is selected from (2R,2R)-2,3-butanediol; The p-toluenesulfonate-based raw material is selected from triethylene glycol di-p-toluenesulfonate.

8. The preparation method according to claim 7, characterized in that, The molar ratio of starting material, p-toluenesulfonate-based raw material, and sodium hydroxide is 1:(0.5~1.5):(2~3).

9. The preparation method according to claim 7, characterized in that, The ratio of the starting material to 1,4-dioxane is 1 mmol: 4~8 mL.

10. The preparation method according to claim 7, characterized in that, The conditions for the reflux reaction include: a reaction temperature of 90~110℃ and a reaction time of 48~72h.

11. The application of the X-ray luminescent material of claim 1 in X-ray detection.

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