Organic small molecule ionic crystal and preparation method thereof, and application as photochromic material
By synthesizing organic small molecule ionic crystals containing [H2imb]2+ groups and anionic groups, the problem of the inability to characterize the dose of photochromic materials in the early stage of X-ray radiation was solved, and simple and safe X-ray detection was achieved.
Patent Information
- Application Number
- CN202210010178.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-01-06
- Publication Date
- 2025-09-26
- Estimated Expiration
- 2042-01-06
AI Technical Summary
Existing photochromic materials cannot effectively characterize the dose in the early stages of X-ray radiation, making it difficult to avoid the risk of X-ray leakage.
Organic small molecule ionic crystals containing [H2imb]2+ groups and anionic groups such as Cl- or (NO3)- are synthesized through a one-step reaction to form a chair or boat conformation crystal structure with X-ray stimulation responsiveness.
The color change at the initial stage of X-ray radiation is achieved, which effectively characterizes the dose and avoids X-ray leakage. The synthesis is simple, non-toxic and harmless, and is suitable for industrial applications.
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Figure CN116444440B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to an organic small molecule ionic crystal, belonging to the field of single crystal growth. Background Art
[0002] X-rays are widely used in medical diagnosis and treatment, scientific research, industrial flaw detection, and nuclear research. However, due to their ultra-high photon energy and ultra-short wavelength, X-rays can cause radiation damage to human tissue after reaching a certain dose, whether in natural environments or industrial production. Therefore, X-ray protection and monitoring during use are crucial. Using photochromic materials to indicate the dose through color changes during the initial stages of X-ray exposure can effectively and intuitively mitigate the risk of X-ray leakage.
[0003] The principle of organic photochromic materials is that, under external energy stimulation, their molecular structure undergoes some kind of change, which can manifest as valence isomerism, cis-trans isomerism, bond cleavage, polymerization, oxidation-reduction, and pericyclic reactions. Electron transfer-type photochromic organic small molecule materials have a clear structural framework. Illumination can induce electron transfer in the organic portion, generating free radical ions, which exhibit good reversibility and fatigue resistance. Furthermore, through synthetically regulated structure, their photochromic properties can be adjusted, making them an ideal photochromic material for X-ray detection. However, selecting a photochromic material with an appropriate lifespan is a key prerequisite for its application. Summary of the Invention
[0004] According to one aspect of the present application, an organic small molecule ionic crystal is provided.
[0005] An organic small molecule ionic crystal, comprising a cationic group and an anionic group;
[0006] The cationic group is [H2imb] 2+ group;
[0007] Said [H2imb] 2+ The group is protonated 2,3-dimethyl-2,3-diimidazolin-2-ylbutane.
[0008] Optionally, in the organic small molecule ionic crystal, the anion group is selected from Cl - 、(NO3) - At least one of .
[0009] Alternatively, when the anionic group is Cl - When the organic small molecule ionic crystals contain crystalline water.
[0010] Alternatively, when the anionic group is Cl- When the organic small molecule ionic crystal belongs to the orthorhombic system and the Pbca space group;
[0011] The inventors of the present application have found that [H2imb](NO3)2 crystallizes in the Cmca space group, [H2imb] 2+ Under the action of nitrate anion, a chair conformation is formed, and the angle between C1-C2-C3 is 107.721°. [H2imb]Cl2·H2O crystallizes in the Pbca space group, [H2imb] 2+ Under the action of chloride ions and water molecules, a boat-type conformation is formed, and the angle between C1-C2-C3 is 109.46-111.97°.
[0012] Preferably, the unit cell parameters of the organic small molecule ionic crystal are α=β=γ=90°, Z = 8;
[0013] Further preferably, in the positive ion portion of the organic small molecule ionic crystal, two imidazole rings are bridged by 2,3-dimethylbutanediyl and are located on the same side thereof to form a boat-type conformation, Cl - Located in the gap.
[0014] Alternatively, when the anionic group is (NO3) - When the organic small molecule ionic crystal belongs to the orthorhombic system and the Cmca space group;
[0015] Preferably, the unit cell parameters of the organic small molecule ionic crystal are α=β=γ=90°, Z = 16;
[0016] Further preferably, in the positive ion part of the organic small molecule ionic crystal, two imidazole rings are bridged by 2,3-dimethylbutanediyl and located on both sides thereof to form a chair conformation, NO3 - Located in the gap.
[0017] The second aspect of the present application provides methods for producing the above two organic small molecule ionic crystals.
[0018] The above-mentioned method for producing organic small molecule ionic crystals comprises the following steps:
[0019] Mixing reactants including azobisisobutylimidazoline hydrochloride ([H2azoimp]Cl2) and a methanol solution in a reaction container and reacting to obtain the [H2imb]Cl2·H2O;
[0020] The molecular formula of the azobisisobutylimidazoline hydrochloride is C 12 H 24 Cl2N6, the structural formula can be represented by formula I:
[0021]
[0022] Optionally, the following steps are included:
[0023] Mixing reactants including azobisisobutylimidazoline hydrochloride, cobalt nitrate hexahydrate, and methanol solution in a reaction container and reacting to obtain the [H2imb](NO3)2;
[0024] Preferably, the concentration of the cobalt nitrate hexahydrate in the reactant is any value among 0.005 g / mL, 0.006 g / mL, 0.007 g / mL, 0.008 g / mL, 0.009 g / mL, 0.01 g / mL, or a value in a range consisting of any two values.
[0025] Optionally, in the reaction, the reaction temperature is independently any value among 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, or a value in the range of any two values, and the reaction time is any value among 12h, 15h, 18h, 21h, 24h, 27h, 30h, 33h, 36h, or a value in the range of any two values.
[0026] Preferably, the concentration of the azobisisobutylimidazoline hydrochloride methanol solution is any value among 0.005 g / mL, 0.006 g / mL, 0.007 g / mL, 0.008 g / mL, 0.009 g / mL, 0.01 g / mL, or a value in the range consisting of any two values.
[0027] The third aspect of the present application provides a photochromic material.
[0028] A photochromic material, comprising the above-mentioned [H2imb] 2+ Organic small molecule crystals containing [H2imb] groups and / or the organic small molecule crystals containing [H2imb] obtained by the above method 2+ Organic small molecule crystals of groups.
[0029] The fourth aspect of the present application provides the application of the above-mentioned photochromic material in X-ray detection.
[0030] An application of a photochromic material in X-ray detection, wherein the photochromic material is the above-mentioned photochromic material.
[0031] The beneficial effects of this application include:
[0032] 1) The organic small molecule ionic crystals provided in this application have X-ray stimulus response properties and can be used to detect X-rays
[0033] 2) The organic small molecule ionic crystals provided in this application are non-toxic and harmless, and are conducive to subsequent applications;
[0034] 3) The method for synthesizing organic small molecule ionic crystals provided in this application is simple to synthesize, and the product can be obtained in only one step, which is suitable for industrialization. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 [H2imb] in the materials obtained in Examples 1 and 2 of this application 2+ Schematic diagram of the structure of the group;
[0036] Figure 2 This is a schematic diagram of the structure of the material obtained in Example 1 of the present application;
[0037] Figure 3 This is a schematic diagram of the structure of the material obtained in Example 2 of the present application;
[0038] Figure 4 This is an X-ray photochromic effect diagram of the material obtained in Example 2 of the present application;
[0039] Figure 5 This is the infrared spectrum analysis diagram of the material obtained in Example 1 of the present application;
[0040] Figure 6 This is an infrared spectrum analysis diagram of the sample obtained in Example 2 of the present application before and after X-ray irradiation;
[0041] Figure 7 Thermogravimetric analysis spectra of the samples obtained in Examples 1 and 2 of the present application;
[0042] Figure 8 The X-ray diffraction pattern of the sample obtained in Example 1 of the present application, and the X-ray diffraction pattern of the sample obtained in Example 1 under theory;
[0043] Figure 9 The theoretical X-ray diffraction pattern of the sample obtained in Example 2 of the present application, the X-ray diffraction pattern before and after X-ray irradiation, and the X-ray diffraction pattern of the sample that faded after X-ray irradiation;
[0044] Figure 10 This is a UV-visible diffuse reflectance test graph of the sample obtained in Example 2 of the present application, and the sample obtained in Example 2 with water removed; DETAILED DESCRIPTION
[0045] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.
[0046] Unless otherwise specified, the raw materials and catalysts in the examples of the present application were purchased through commercial channels, wherein azobisisobutylimidazoline hydrochloride and cobalt sulfate hexahydrate were purchased from Adamas, and methanol was purchased from Sinopharm.
[0047] The analysis method in the examples of this application is as follows:
[0048] The structure of the samples was analyzed using a Mo target in a Bruker D8 Venture single crystal diffractometer at 200 K.
[0049] X-ray powder diffraction analysis and X-ray photochromism treatment were performed on the samples using a Rigaku Miniflex 600 model X-ray powder diffractometer;
[0050] The UV-visible diffuse reflectance test of the samples was performed using an Agilent Cary 5000 UV-visible-near-infrared spectrophotometer;
[0051] Thermogravimetric analysis of the samples was performed using a Mettler-Toledo TGA / DSC 1 model simultaneous thermal analyzer;
[0052] The samples were analyzed by infrared spectroscopy using a Thermo Nicolet is50 Fourier transform infrared spectrometer.
[0053] The samples were analyzed by X-ray photoelectron spectroscopy using a Thermo Fisher ESCALAB 250Xi X-ray photoelectron spectrometer.
[0054] Example 1
[0055] 300 mg of azobisisobutylimidazoline hydrochloride and 300 mg of cobalt nitrate hexahydrate were added to 50 mL of methanol solution, heated at 80° C. for 24 hours, cooled to room temperature, filtered, and the filtrate was evaporated to obtain a white powder sample, namely the [H2imb](NO3)2. The obtained sample is numbered 1#, and the crystal structure data of this sample is shown in Table 1.
[0056] Example 2
[0057] 300 mg of azobisisobutylimidazoline hydrochloride was added to 50 mL of methanol solution, heated at 80°C for 24 hours, cooled to room temperature, filtered, and the filtrate was evaporated to obtain a white powder sample, namely the [H2imb]Cl2·H2O. The obtained sample was numbered 2#. The crystal structure data of this sample is shown in Table 1.
[0058] Comparative Example 1
[0059] 300 mg of azobisisobutylimidazoline hydrochloride and 300 mg of cobalt nitrate hexahydrate were added to 50 mL of methanol solution, heated at 150° C. for 24 hours, cooled to room temperature, filtered, and the filtrate was evaporated to obtain a black solid.
[0060] The black solid obtained in Comparative Example 1 was irradiated with X-rays, and it was found that the substance did not have the property of changing color by X-rays.
[0061] Comparative Example 2
[0062] 300 mg of azobisisobutylimidazoline hydrochloride and 300 mg of cobalt nitrate hexahydrate were added to 50 mL of methanol solution, heated at 50° C. for 24 hours, cooled to room temperature, and filtered to obtain no product.
[0063] The crystal structure data of the materials obtained in Examples 1 and 2 of the present invention are shown in Table 1.
[0064] Table 1
[0065]
[0066] Sample 2# was used as the main research object. Sample 2# was irradiated with X-rays (radiation X-ray power was 2kW) for different time periods (0, 0.5, 1, 2 and 3 hours). The color changes after different irradiation times were as follows: Figure 4 As shown, it shows that the sample of Example 2 has a very good X-ray induced color change effect. Infrared spectroscopy analysis was performed on sample 1#, sample 2# and sample 2# after color change by X-ray irradiation. The results showed that the functional groups and structures obtained by characterization of sample 1# and sample 2# were consistent, and after X-ray irradiation, the structure of sample 2# remained basically the same as before irradiation. Thermogravimetric analysis was performed on sample 1# and sample 2# respectively, and the results showed that the skeleton structure of sample 1# can be stabilized to about 250°C, sample 2# loses water at 100°C, and its skeleton structure can be stabilized to about 300°C. Its thermogravimetric detection diagram is shown as follows Figure 7 The X-ray powder diffraction patterns of Sample 1#, Sample 2#, and their discoloration and fading after X-ray irradiation were compared with theoretical simulation patterns obtained by fitting single crystal data, as shown in the figure. The results show that Sample 1#, Sample 2#, and their discoloration and fading products after X-ray irradiation are all highly crystalline and pure.
[0067] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. Application of a photochromic material in X-ray detection, characterized in that: The photochromic material includes organic small molecule ionic crystals; The organic small molecule ionic crystal includes a cationic group and an anionic group; The cationic group is [H2imb] 2+ group; Said [H2imb] 2+ The group is protonated 2,3-dimethyl-2,3-diimidazolin-2-ylbutane; In the organic small molecule ionic crystal, the anion group is selected from Cl - 、(NO3) - At least one of; When the anionic group is Cl - When the organic small molecule ionic crystals further contain crystal water; the organic small molecule ionic crystals belong to the orthorhombic crystal system and the Pbca space group; the unit cell parameters of the organic small molecule ionic crystals are a=13.5867±0.0002 Å, b=9.7050±0.002 Å, c=23.928±0.003 Å, α=β=γ=90°, V=3155.1±0.1 Å 3 ,Z=8; When the anion group is (NO3) - When the organic small molecule ionic crystal belongs to the orthorhombic system and the Cmca space group, the unit cell parameters of the organic small molecule ionic crystal are a=9.708±0.003 Å, b=12.991±0.005 Å, c=12.614±0.005 Å, α=β=γ=90°, V=1590.8±1 Å 3 , Z=16.
2. The use according to claim 1, characterized in that When the anionic group is Cl - When the positive ion part of the organic small molecule ionic crystal is formed, the two imidazole rings are bridged by 2,3-dimethylbutanediyl and are located on the same side thereof to form a boat-type conformation. - Located in the gap.
3. The use according to claim 1, characterized in that When the anion group is (NO3) - When the positive ion part of the organic small molecule ionic crystal is formed, the two imidazole rings are bridged by 2,3-dimethylbutanediyl and located on both sides thereof to form a chair conformation, NO3 - Located in the gap.
4. The use according to claim 1, characterized in that When the anionic group is Cl - When the organic small molecule ionic crystal is prepared, the method comprises the following steps: Mixing reactants including azobisisobutylimidazoline hydrochloride and a methanol solution in a reaction vessel and reacting to obtain [H2imb]Cl2·H2O; the reaction temperature is 60-100°C; The molecular formula of the azobisisobutylimidazoline hydrochloride is C 12 H 24 Cl2N6, the structural formula is shown in Formula I: (Formula I).
5. The use according to claim 1, characterized in that When the anion group is (NO3) - When the organic small molecule ionic crystal is prepared, the method comprises the following steps: A reactant comprising azobisisobutylimidazoline hydrochloride, cobalt nitrate hexahydrate, and a methanol solution is mixed in a reaction container and reacted to obtain [H2imb](NO3)2; the reaction temperature is 60-100°C.
6. The use according to claim 5, characterized in that The concentration of the cobalt nitrate hexahydrate in the reactants is 0.005-0.01 g / mL.
7. The use according to claim 4 or 5, characterized in that The reaction time is 12-36h.
8. The use according to claim 4 or 5, characterized in that The concentration of the azobisisobutylimidazoline hydrochloride methanol solution is 0.005-0.01 g / mL.