Preparation method and application of pure organic X-ray scintillator material

Abstract

The invention discloses a preparation method and application of a pure organic X-ray scintillator material, and belongs to the field of optical functional materials. The material of the scintillator contains a phenoselenazine unit, and the material of the scintillator is one of # imgabs 0 #, # imgabs 1 #, # imgabs 2 #, # imgabs 3 #, # imgabs 4 # and # imgabs 5 #. According to the scintillator material disclosed by the invention, the spatial position of a heavy atom is regulated and controlled by adjusting the position of a methyl substituent, so that the X-ray radiation luminescence property is regulated and controlled. Compared with a traditional inorganic scintillator material, the scintillator material is simple in preparation method, easy to obtain, low in cost and high in machinability. After the scintillator material is made into a glassy state, clear imaging under X-rays is achieved, and the scintillator material has certain application potential in the field of medical X-ray imaging and the field of safety inspection.

Description

Technical Field

[0001] The invention relates to the field of optical functional materials, and in particular to a preparation method and application of a pure organic X-ray scintillator material. Background Art

[0002] X-ray responsive materials with large X-ray attenuation coefficients due to their heavy element composition have important applications in bioimaging, radiotherapy, and nondestructive testing. Conventional X-ray responsive materials include non-emissive radiocontrast agents (e.g., iodohexanol and iodopropylamine) and ceramic scintillators, which can convert high-energy X-ray beams into low-energy visible photons. Existing X-ray scintillators reported in studies are limited to inorganic phosphors or organometallic complexes containing heavy metals.

[0003] Metal-free organic phosphors have inherent advantages as scintillators, such as abundant resource supply, high mechanical flexibility, easy processing and large-scale manufacturing; however, weak X-ray absorption and inefficient exciton utilization have hindered the development of organic molecular scintillators. Organic phosphors are mainly composed of carbon, hydrogen, nitrogen and other light atoms, and have weak absorption of X-rays (attenuation coefficient μ∝Z 4 ). In addition, the weak spin-orbit coupling of conventional organic phosphors can only generate fluorescence from singlet excitons after irradiation. In principle, about 75% of the excitons are not well utilized due to the dark state characteristics of triplet excitons in metal-free organophosphors.

[0004] At room temperature, bright triplet excitons in organic light-emitting materials can generate phosphorescence. One strategy to achieve room temperature phosphorescence is to promote the intersystem crossing process (ISC) by heavy halogen atoms or aromatic carbonyl groups. It is worth noting that the ISC rate constant (k ISC ) is proportional to the atomic number 30 to the eighth power (k ISC ∝Z 8 ), indicating that heavy atoms can effectively fill triplet excitons. Another strategy is to construct a rigid environment to suppress non-radiative energy dissipation through crystal engineering, host-guest doping or polymerization, where halogen atoms can effectively harvest triplet excitons due to enhanced spin-orbit coupling.

[0005] X-ray scintillators are inseparable from phosphorescence. Some studies have achieved the regulation of phosphorescence properties by changing the substitution position of halogen atoms or the number of substituents to adjust the relative position of heavy atoms and chromophores. Some studies have shown that the spatial position of halogen atoms can be indirectly regulated by introducing groups with certain steric hindrances, determining the position of halogen atoms, and adjusting the position of steric hindrance groups, thereby achieving the regulation of phosphorescence properties. However, at present, whether in the field of phosphorescence or organic X-ray scintillators, the in-depth mechanism of the influence of halogen atoms on luminescence properties is still unknown.

[0006] In view of this, it is indeed necessary to provide a technical solution to the above problems. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a preparation method and application of a pure organic X-ray scintillator material.

[0008] According to one aspect of the present invention, a pure organic X-ray scintillator material is provided, wherein the scintillator material contains a pheneselenazine unit. , , , , or One of them.

[0009] According to a second aspect of the present invention, a method for preparing the pure organic X-ray scintillator material is proposed, and the preparation method is as follows: S1. Under a nitrogen atmosphere, pheneselenazine, a base, a palladium catalyst and tri-tert-butylphosphine tetrafluoroborate are first dissolved in a toluene solution to form a mixed solution, which is heated to 90° C. and refluxed for 0.5 h; S2. Under a nitrogen atmosphere, the mixed solution is added into a toluene solution containing halogenated benzene, heated to 90° C. and refluxed for 5 h to obtain a pure organic X-ray scintillator material.

[0010] Furthermore, the base is potassium tert-butoxide or sodium tert-butoxide.

[0011] Furthermore, the palladium catalyst is palladium acetate or tris dibenzylideneacetone dipalladium.

[0012] Furthermore, the halogenated benzene is any one of 1-bromo-4-iodobenzene, 2-bromo-5-iodotoluene, 5-bromo-2-iodotoluene, 1-bromo-3-iodobenzene, 2-bromo-4-iodotoluene or 2-bromo-6-iodotoluene.

[0013] Further, the structural formula of the 1-bromo-4-iodobenzene is The structural formula of the 2-bromo-5-iodotoluene is , the structural formula of the 5-bromo-2-iodotoluene is , the structural formula of the 1-bromo-3-iodobenzene is , the structural formula of the 2-bromo-4-iodotoluene is , the structural formula of the 2-bromo-6-iodotoluene is .

[0014] Furthermore, the structural formula of the pheneselenazine is .

[0015] Furthermore, the molar ratio of the pheneselenazine, the base, the palladium catalyst and tri-tert-butylphosphine tetrafluoroborate is 5: (5-7): (0.2-0.5): (0.2-0.5).

[0016] Furthermore, the molar ratio of the phenoselenazine to the halogenated benzene is 5:(5-7).

[0017] According to a third aspect of the present invention, an application of the pure organic X-ray scintillator material in the field of medical X-ray imaging and security inspection is proposed.

[0018] Beneficial effects of the present invention: The pure organic X-ray scintillator material provided by the present invention adjusts the position of the methyl substituent, resulting in different steric hindrance effects, affecting the relative position of the heavy atom and the chromophore, thereby achieving the regulation of the performance of the scintillator material, so that the scintillator material exhibits different radioluminescence properties. Compared with traditional inorganic scintillator materials, the preparation method of the pure organic X-ray scintillator material provided by the present invention is simple, low in cost, and has strong processability. After the scintillator material is made into a glassy state, it can achieve clear imaging under X-rays, providing material support for the field of X-ray imaging. The scintillator material has certain application potential in the field of medical X-ray imaging and security inspection. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a nuclear magnetic resonance hydrogen spectrum of the scintillator material of formula (I) described in the embodiment of the present invention; Figure 2 is a nuclear magnetic resonance hydrogen spectrum of the scintillator material of formula (II) described in the embodiment of the present invention; Figure 3 is a nuclear magnetic resonance hydrogen spectrum of the scintillator material of formula (III) described in the embodiment of the present invention; Figure 4 is a nuclear magnetic resonance hydrogen spectrum of the scintillator material of formula (IV) described in the embodiment of the present invention; Figure 5 is a hydrogen nuclear magnetic resonance spectrum of the scintillator material of formula (V) described in an embodiment of the present invention; Figure 6 is a hydrogen nuclear magnetic resonance spectrum of the scintillator material of formula (VI) described in an embodiment of the present invention; Figure 7 Graph showing the test results of the photophysical properties of the scintillator materials of formula (I), formula (II) and formula (III) described in the embodiments of the present invention; Figure 8 Graph showing the test results of the photophysical properties of the scintillator materials of formula (IV), formula (V) and formula (VI) described in the embodiments of the present invention; Fig. 9is a radioluminescence spectrum diagram of the scintillation material described in an embodiment of the present invention under X-ray stimulation; Fig.10 is a result diagram of the X-ray detection limit of the scintillator material of formula (II) described in the embodiment of the present invention; Fig.11 An imaging image of the scintillator material of formula (II) in the glass state described in the embodiment of the present invention; Fig.12 Graph showing the modulation transfer function of the scintillator material of formula (II) in the glassy state according to the embodiment of the present invention. DETAILED DESCRIPTION

[0020] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0022] Since the current X-ray scintillators are limited to inorganic phosphors or organic metal complexes containing heavy metals, and the in-depth mechanism of the influence of halogen atoms on luminescence performance is still unknown, the first object of the present invention is to propose a pure organic X-ray scintillator material, which realizes the regulation of the spatial position of heavy atoms, thereby realizing the regulation of the X-ray radiation luminescence properties.

[0023] The second object of the present invention is to provide a method for preparing the pure organic X-ray scintillator material, which has the advantages of simple preparation method, low cost and strong processability.

[0024] The third object of the present invention is to propose an application of the pure organic X-ray scintillator material in the field of medical X-ray imaging and security inspection.

[0025] Example 1: Preparation of scintillator material of formula (I) Take 1.24g (5mmol) of pheneselenazine, 1.70g (6mmol) of sodium tert-butoxide (t-BuONa), 0.229g (0.25mmol) of tridibenzylideneacetone palladium (Pd(dba)2) and 0.073g (0.25mmol) of tri-tert-butylphosphine tetrafluoroborate (P(t-Bu)3HBF4), add 40ml of toluene to dissolve under nitrogen atmosphere, heat to 90℃ and reflux for 0.5h. Take 1-bromo-4-iodobenzene, 1.69g (6mmol), dissolve in 20ml of toluene under nitrogen atmosphere, heat to 90℃ and reflux. Add a series of pheneselenazine solutions dropwise and reflux at 90℃ for 5h. Cool to room temperature, extract with ethyl acetate and saturated brine, retain the organic phase, add anhydrous magnesium sulfate to dry, filter, heat and evaporate to remove excess solvent to obtain a crude product, use column chromatography (pure petroleum ether) to obtain the scintillator material of formula (I), use dichloromethane and ethanol for recrystallization, and obtain a product mass of 0.62g with a yield of 31%. The specific preparation reaction formula is as follows:

[0026] The scintillator material of formula (I) is characterized by a nuclear magnetic resonance spectrum. Figure 1 Shown: 1HNMR (500 MHz, DMSO-d6) δ 7.54 (dd, J = 14.3, 8.2 Hz, 4H), 7.24 (t, J = 7.7Hz, 2H), 7.10 (t, J = 7.4 Hz, 2H), 7.04 (d, J = 8.8 Hz, 2H), 6.99 (d, J = 8.0Hz, 2H). Example 2: Preparation of scintillator material of formula (II) Take 1.24g (5mmol) of pheneselenazine, 1.70g (6mmol) of sodium tert-butoxide (t-BuONa), 0.229g (0.25mmol) of tridibenzylideneacetone palladium (Pd(dba)2) and 0.073g (0.25mmol) of tri-tert-butylphosphine tetrafluoroborate (P(t-Bu)3HBF4), add 40ml of toluene to dissolve under nitrogen atmosphere, heat to 90℃ and reflux for 0.5h. Take another 1.79g (6mmol) of 2-bromo-5-iodotoluene, dissolve it in 20ml of toluene under nitrogen atmosphere, heat to 90℃ and reflux. Add a series of pheneselenazine solutions dropwise, and reflux at 90℃ for 5h. Cool to room temperature, extract with ethyl acetate and saturated brine, retain the organic phase, add anhydrous magnesium sulfate to dry, filter, heat and evaporate to remove excess solvent to obtain a crude product, use column chromatography (pure petroleum ether) to obtain the scintillator material of formula (II), use dichloromethane and ethanol for recrystallization, and obtain a product mass of 0.71g with a yield of 34%. The specific preparation reaction formula is as follows:

[0027] The scintillator material of formula (II) is characterized by a nuclear magnetic resonance spectrum. Figure 2 Shown: 1HNMR (500 MHz, DMSO-d6) δ 7.64 (d, J = 8.5 Hz, 1H), 7.45 (d, J = 7.4 Hz, 2H),7.21 – 7.14 (m, 3H), 7.04 (t, J = 7.4 Hz, 2H), 6.96 (dd, J = 8.5, 2.2 Hz,1H), 6.84 (d, J = 8.0 Hz, 2H), 2.32 (s, 3H). Example 3: Preparation of scintillator material of formula (III) Take 1.24g (5mmol) of pheneselenazine, 1.70g (6mmol) of sodium tert-butoxide (t-BuONa), 0.229g (0.25mmol) of tridibenzylideneacetone palladium (Pd(dba)2) and 0.073g (0.25mmol) of tri-tert-butylphosphine tetrafluoroborate (P(t-Bu)3HBF4), add 40ml of toluene to dissolve under nitrogen atmosphere, heat to 90℃ and reflux for 0.5h. Take another 1.79g (6mmol) of 2-bromo-5-iodotoluene, dissolve it in 20ml of toluene under nitrogen atmosphere, heat to 90℃ and reflux. Add a series of pheneselenazine solutions dropwise, and reflux at 90℃ for 5h. The mixture was cooled to room temperature, extracted with ethyl acetate and saturated brine, the organic phase was retained, anhydrous magnesium sulfate was added for drying, filtered, and the excess solvent was removed by heating and evaporation to obtain a crude product, and the scintillator material of formula (III) was obtained by column chromatography (pure petroleum ether), and recrystallized with dichloromethane and ethanol to obtain a product with a mass of 0.44 g and a yield of 21%. The specific preparation reaction formula is shown below:

[0028] The scintillator material of formula (III) is characterized by a nuclear magnetic resonance spectrum. Figure 3 Shown: 1HNMR (500 MHz, DMSO-d6) δ 7.78 (s, 1H), 7.67 (d, J = 8.3 Hz, 1H), 7.44 (d, J =8.3 Hz, 1H), 7.24 (d, J = 7.5 Hz, 2H), 6.96 (s, 2H), 6.86 (t, J = 7.3 Hz, 2H), 6.18 (d, J = 8.1 Hz, 2H), 2.12 (s, 3H). Example 4: Preparation of scintillator material of formula (IV) Take 1.24g (5mmol) of pheneselenazine, 1.70g (6mmol) of sodium tert-butoxide (t-BuONa), 0.229g (0.25mmol) of tridibenzylideneacetone palladium (Pd(dba)2) and 0.073g (0.25mmol) of tri-tert-butylphosphine tetrafluoroborate (P(t-Bu)3HBF4), add 40ml of toluene to dissolve under nitrogen atmosphere, heat to 90℃ and reflux for 0.5h. Take 1.69g (6mmol) of 1-bromo-4-iodobenzene, dissolve in 20ml of toluene under nitrogen atmosphere, heat to 90℃ and reflux. Add a series of pheneselenazine solutions dropwise, and reflux at 90℃ for 5h. Cool to room temperature, extract with ethyl acetate and saturated brine, retain the organic phase, add anhydrous magnesium sulfate to dry, filter, heat and evaporate to remove excess solvent to obtain a crude product, use column chromatography (pure petroleum ether) to obtain the scintillator material of formula (IV), use dichloromethane and ethanol for recrystallization, and obtain a product mass of 0.51g with a yield of 25%. The specific preparation reaction formula is as follows:

[0029] The scintillator material of formula (IV) is characterized by a nuclear magnetic resonance spectrum. Figure 4 Shown: 1HNMR (500 MHz, DMSO-d6) δ 7.62 (d, J = 7.5 Hz, 2H), 7.33 (t, J = 7.4 Hz, 2H), 7.22 (ddt, J = 21.7, 15.0, 7.6 Hz, 6H), 7.08 (s, 1H), 6.96 (d, J = 7.6 Hz, 1H). Example 5: Preparation of scintillator material of formula (V) Take 1.24g (5mmol) of pheneselenazine, 1.70g (6mmol) of sodium tert-butoxide (t-BuONa), 0.229g (0.25mmol) of tridibenzylideneacetone palladium (Pd(dba)2) and 0.073g (0.25mmol) of tri-tert-butylphosphine tetrafluoroborate (P(t-Bu)3HBF4), add 40ml of toluene to dissolve under nitrogen atmosphere, heat to 90℃ and reflux for 0.5h. Take another 1.79g (6mmol) of 2-bromo-4-iodotoluene, dissolve it in 20ml of toluene under nitrogen atmosphere, heat to 90℃ and reflux. Add a series of pheneselenazine solutions dropwise, and reflux at 90℃ for 5h. Cool to room temperature, extract with ethyl acetate and saturated brine, retain the organic phase, add anhydrous magnesium sulfate to dry, filter, heat and evaporate to remove excess solvent to obtain a crude product, use column chromatography (pure petroleum ether) to obtain the scintillator material of formula (V), use dichloromethane and ethanol for recrystallization, and obtain a product mass of 0.40g with a yield of 18%. The specific preparation reaction formula is as follows:

[0030] The scintillator material of formula (V) is characterized by a nuclear magnetic resonance spectrum. Figure 5 Shown: 1HNMR (500 MHz, DMSO-d6) δ 7.48 (d, J = 7.7 Hz, 2H), 7.41 (d, J = 8.3 Hz, 1H), 7.34 (d, J = 2.3 Hz, 1H), 7.20 (t, J = 7.7 Hz, 2H), 7.11 (dd, J = 8.3, 2.3Hz, 1H), 7.06 (t, J = 7.5 Hz, 2H), 6.87 (d, J = 8.1 Hz, 2H), 2.35 (s, 3H). Example 6: Preparation of scintillator material of formula (VI) Take 1.24g (5mmol) of pheneselenazine, 1.70g (6mmol) of sodium tert-butoxide (t-BuONa), 0.229g (0.25mmol) of tridibenzylideneacetone palladium (Pd(dba)2) and 0.073g (0.25mmol) of tri-tert-butylphosphine tetrafluoroborate (P(t-Bu)3HBF4), add 40ml of toluene to dissolve under nitrogen atmosphere, heat to 90℃ and reflux for 0.5h. Take another 1.79g (6mmol) of 2-bromo-6-iodotoluene, dissolve it in 20ml of toluene under nitrogen atmosphere, heat to 90℃ and reflux. Add a series of pheneselenazine solutions dropwise, and reflux at 90℃ for 5h. Cool to room temperature, extract with ethyl acetate and saturated brine, retain the organic phase, add anhydrous magnesium sulfate to dry, filter, heat and evaporate to remove excess solvent to obtain a crude product, use column chromatography (pure petroleum ether) to obtain the scintillator material of formula (VI), use dichloromethane and ethanol for recrystallization, and obtain a product mass of 0.36g with a yield of 17%. The specific preparation reaction formula is as follows:

[0031] The scintillator material of formula (VI) is characterized by a nuclear magnetic resonance spectrum. Figure 6 Shown: 1HNMR (500 MHz, DMSO-d6) δ 7.82 (d, J = 8.0 Hz, 1H), 7.53 (d, J = 7.8 Hz, 1H), 7.45 (t, J = 7.8 Hz, 1H), 7.26 (d, J = 7.5 Hz, 2H), 6.98 (t, J = 7.7 Hz, 2H), 6.87 (t, J = 7.4 Hz, 2H), 6.17 (d, J = 8.3 Hz, 2H), 2.23 (s, 3H). Example 7: Performance comparison of scintillator materials Photophysical properties test The photophysical properties of the scintillator materials of formula (I), formula (II), formula (III), formula (IV), formula (V) and formula (VI) obtained in Examples 1 to 6 were tested. The results are as follows: Figure 7 and Figure 8 shown.

[0032] Figure 7 wherein p-BPSe, p-2BPSe and p-3B correspond to the scintillator materials of formula (I), formula (II) and formula (III) respectively. Figure 7 It can be seen from the a in that under the excitation of 365nm ultraviolet light, the scintillator materials of formula (I), formula (II) and formula (III) all exhibit obvious blue-green emission. The luminescence lifetime of this wavelength is tested, and the test results are as follows: Figure 7 As shown in b, the lifetimes of the scintillator materials of formula (I), formula (II) and formula (III) are 217μs, 60μs and 94μs respectively, all of which are lifetimes of the order of microseconds, and are attributed to phosphorescence. Figure 7 From c in the formula, it can be obtained that the phosphorescence quantum efficiencies of the scintillator materials of formula (I), formula (II) and formula (III) are 17%, 10% and 14% respectively.

[0033] Figure 8 The m-BPSe, m-2BPSe and m-6BPSe in the formula correspond to the scintillator materials of formula (IV), formula (V) and formula (VI), respectively. Figure 8 It can be seen from the a in that under the excitation of 365nm ultraviolet light, the scintillator materials of formula (IV), formula (V) and formula (VI) all exhibit obvious blue-green emission. The luminescence lifetime of this wavelength is tested, and the test results are as follows: Figure 8 As shown in b, the lifetimes of the scintillator materials of formula (IV), formula (V) and formula (VI) are 1106μs, 41μs and 29μs respectively, all of which are lifetimes of the order of microseconds, and are attributed to phosphorescence. Figure 8 From c in the formula, it can be obtained that the phosphorescence quantum efficiencies of the scintillator materials of formula (IV), formula (V) and formula (VI) are 23%, 10% and 5%, respectively.

[0034] Take 50 mg of each of the scintillator materials of formula (I), formula (II), formula (III), formula (IV), formula (V) and formula (VI) and test their radioluminescence properties under X-ray. The results are as follows Fig. 9 As shown, except for the scintillator material of formula (IV), the other scintillator materials all exhibit good radiation luminescence performance, among which the scintillator material of formula (II) has the best comprehensive properties.

[0035] Comparison of Photoluminescence Properties The photoluminescent properties of the scintillator materials of formula (I), formula (II), formula (III), formula (IV), formula (V) and formula (VI) obtained in Examples 1 to 6 were compared, mainly including the comparison of luminescent wavelength, efficiency and lifespan. The results are as follows: Fig. 9 shown. Fig. 9 Among them, p-BPSe, p-2BPSe, p-3B, m-BPSe, m-2BPSe and m-6BPSe correspond to the scintillator materials of formula (I), formula (II), formula (III), formula (IV), formula (V) and formula (VI) respectively.

[0036] Depend on Fig. 9From the a in the formula, it can be seen that the scintillator materials of formula (I), formula (II) and formula (III) show almost the same luminescence peak position, but the lifetime and luminescence efficiency of the three show obvious differences: the scintillator material of formula (I) is 217μs, 17%; the scintillator material of formula (II) is 60μs, 10%; the scintillator material of formula (III) is 94μs, 14%. Under X-ray stimulation, the three show obvious intensity differences, which not only illustrates the feasibility of the strategy of regulating the position of heavy atoms through methyl groups to achieve the regulation of luminescence properties, but also shows the application potential of these materials under radiation.

[0037] Depend on Fig. 9 From b in the formula, it can be seen that the scintillator materials of formula (IV), formula (V) and formula (VI) exhibit almost the same luminescence peak position, but the lifetime and luminescence efficiency of the three show obvious differences: the scintillator material of formula (IV) is 1106μs, 23%; the scintillator material of formula (V) is 41μs, 10%; the scintillator material of formula (VI) is 29μs, 5%. Under the stimulation of X-rays, the three also show obvious intensity differences. The scintillator material of formula (IV) basically has no radioluminescence property, and the radioluminescence performance of the scintillator material of formula (V) and the scintillator material of formula (VI) has been gradually greatly improved. This not only illustrates the feasibility of the strategy of regulating the position of heavy atoms through methyl groups to achieve the regulation of luminescence properties, but also shows the application potential of these materials under radiation.

[0038] 3. X-ray imaging test Since the scintillator material of formula (II) exhibited good comprehensive properties in the above experiments, the scintillator material of formula (II) was used for X-ray imaging test.

[0039] Take 50 mg of the scintillator material of formula (II) and test its X-ray detection limit. The result is as follows: Fig.10 As shown, it can be seen that the scintillator material of formula (II) exhibits a good detection limit value, specifically 175 nGy / s.

[0040] Then, 100 mg of the scintillator material of formula (II) is placed on a glass cover plate, heated to 180° C. to completely melt the material to present a colorless transparent liquid state, and then cooled to room temperature to form a uniform transparent glass state, and then the obtained material is used for X-ray imaging testing and imaging. Fig.11 The transparency of the film and its imaging photos are shown. The scintillator material of formula (II) exhibits good photoluminescence and radioluminescence behavior, the label with Santa Claus pattern is well presented, and the chip imaging also shows a clear texture pattern. Then the resolution of the scintillator material of formula (II) in the glass state is tested, and the results are as follows Fig.12As shown, the resolution of the scintillator material of formula (II) can reach 27.5 lp / mm, showing great potential in radiographic imaging.

[0041] The above describes the specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A pure organic X-ray scintillator material, characterized in that: The scintillator material contains a pheneselenazine unit, and the scintillator material is , , , , or One of them.

2. A method for preparing a pure organic X-ray scintillator material as claimed in claim 1, characterized in that: The preparation method is as follows: S1. Under a nitrogen atmosphere, pheneselenazine, a base, a palladium catalyst and tri-tert-butylphosphine tetrafluoroborate are first dissolved in a toluene solution to form a mixed solution, which is then heated to 90° C. and refluxed for 0.5 h; S2. Under a nitrogen atmosphere, the mixed solution is added into a toluene solution containing halogenated benzene, heated to 90° C. and refluxed for 5 h to obtain a pure organic X-ray scintillator material.

3. The method for preparing a pure organic X-ray scintillator material according to claim 2, characterized in that: The base is potassium tert-butoxide or sodium tert-butoxide.

4. The method for preparing a pure organic X-ray scintillator material according to claim 2, characterized in that: The palladium catalyst is palladium acetate or tris dibenzylideneacetone dipalladium.

5. The method for preparing a pure organic X-ray scintillator material according to claim 2, characterized in that: The halogenated benzene is any one of 1-bromo-4-iodobenzene, 2-bromo-5-iodotoluene, 5-bromo-2-iodotoluene, 1-bromo-3-iodobenzene, 2-bromo-4-iodotoluene or 2-bromo-6-iodotoluene.

6. The method for preparing a pure organic X-ray scintillator material according to claim 5, characterized in that: The structural formula of the 1-bromo-4-iodobenzene is , the structural formula of the 2-bromo-5-iodotoluene is , the structural formula of the 5-bromo-2-iodotoluene is , the structural formula of the 1-bromo-3-iodobenzene is , the structural formula of the 2-bromo-4-iodotoluene is , the structural formula of the 2-bromo-6-iodotoluene is .

7. The method for preparing a pure organic X-ray scintillator material according to claim 2, characterized in that: The structural formula of the phenoselenazine is .

8. The method for preparing a pure organic X-ray scintillator material according to claim 2, characterized in that: The molar ratio of the phenoselenazine, the base, the palladium catalyst and tri-tert-butylphosphine tetrafluoroborate is 5:(5-7):(0.2-0.5):(0.2-0.5).

9. The method for preparing a pure organic X-ray scintillator material according to claim 2, characterized in that: The molar ratio of the phenoselenazine to the halogenated benzene is 5:(5-7).

10. Application of the pure organic X-ray scintillator material according to claim 1 in the field of medical X-ray imaging and security inspection.

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