Organomineral hybrid zirconium-based polyacid derivatives, process for their preparation and use as photochromic materials
By synthesizing organic-inorganic hybrid zirconium-based polyacid derivatives through self-assembly, the problems of insufficient photochromic rate and stability of existing polyacid-based photochromic materials have been solved, realizing rapid reversible photochromism and inkless printing applications. It has the characteristics of simple, safe and low energy consumption in synthesis.
Patent Information
- Application Number
- CN202311215832.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-20
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2043-09-20
AI Technical Summary
Existing polyacid-based photochromic materials have shortcomings in terms of photochromic rate and stability, and their synthesis process is complex and energy-intensive, making it difficult to meet the needs of practical applications.
A self-assembly synthesis strategy was adopted to prepare an organic-inorganic hybrid zirconium-based polyacid derivative in aqueous solution. By reacting DL-tartaric acid, sodium tungstate, dimethylamine hydrochloride, and Na9[SbW9O33]·19.5H2O with ZrOCl2·8H2O, a zirconium-based polyacid derivative with rapid and reversible photochromic properties was formed. Photochromism was achieved by utilizing the W6+→W5+ charge transfer.
It achieves rapid and reversible photochromic performance, improves the photochromic rate, and has a simple, safe, and low-energy synthesis process. It also maintains stability under different ambient temperatures and is suitable for inkless printing applications.
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Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of polyacid-based photochromic materials, specifically relating to an example of a zirconium-based polyacid derivative with photochromic organic-inorganic hybrid structure, its preparation method, and its application as a photochromic material. Background Technology
[0002] Organic-inorganic hybrid covalent materials possess excellent physicochemical properties and have been widely researched and applied in fields such as catalysis and materials science. Polymetallic hydrochlorides, or polyacids for short, have been extensively studied in recent years due to their remarkable stability, catalytic properties, and magnetic properties. Zr 4+ Zr ions possess high oxidation states, large ionic radii, and variable coordination modes; therefore, Zr... 4+ Substituted polyacids exhibit structural features distinct from those substituted with lanthanides and transition metals (TM). Introducing organic carboxylic acid ligands into polyacids via covalent bonding is a highly effective synthetic strategy for synthesizing organic-inorganic hybrid materials, as the oxygen atom on the carboxylic acid can replace the oxygen atom on the metal-oxygen polyhedron in the polyacid to form a covalent bond.
[0003] In recent years, zirconium-substituted polyacid derivatives with carboxylic acid functionalization have been gradually reported, most exhibiting dimerized sandwich structures. In this system, Zr... 4+ It is embedded into the vacancy site of the polyacid building block, while the organic carboxylic acid ligand acts as a ligand with Zr. 4+ Coordination leads to the formation of diverse structures, exhibiting excellent catalytic and proton-conducting properties. Based on this synthetic strategy, in 2013, the inventors discovered a series of ligands composed of different O-donor ligands [Zr4(μ3-O)2(μ-O2)2(Ac)2(P2W]. 16 O 59 )2] 18− ,[Zr4(μ3-O)2(Mal)2(H2O)2(P2W 16 O 59 )2] 16− and [{Zr4(OH)6(Ac)2}(SiW 10 O 37 )2-Modified inorganic-organic hybrid tetranuclear zirconium-substituted phosphotungstate (D. Li, H. Han, Y. Wang, et al. European Journal of Inorganic Chemistry, 2012, (10-11):1926-1934). In 2018, the applicant reported oxalate-functionalized Zr4-substituted dimer silicotungstate [Zr4(μ3-O)2(μ-OH)2(ox)2(SiW 10 O 37 )2]14- (Y. Wang, Z. Zhang, H. Li, et al. European Journal of Inorganic Chemistry, 2019, 2019(3-4): 417-422). In the same year, two new examples of Zr4 cluster sandwich Keggin-type polyoxometalates were reported, namely Zr4(H2O)2(μ-OH)(μ3-O)2(D-tartH)(GeW 10 O 37 )2] 12- And glycolic acid-functionalized Zr4(H2O)2(μ-OH)(μ3-O)2(gly)2(GeW 10 O 37 )2] 12- (Z. Ni, H. Li, X. Li, et al. CrystEngComm, 2019, 21(5): 876-883). In terms of the properties of polyacids themselves, they can accept one or more electrons without decomposing the skeleton, forming heteropolyblues with mixed valence states. Summary of the Invention
[0004] The purpose of this invention is to overcome the defects of the existing technology and provide an example of an organic-inorganic hybrid zirconium-based polyacid derivative, its preparation method, and its application as a photochromic material.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] An example of an organic-inorganic hybrid zirconium-based polyacid derivative, wherein the molecular formula of the zirconium-based polyacid derivative is [H2N(CH3)2]. 10 H8[Zr(DL-tartH)2(SbW 17 ZrO 58 )2]·36H2O (DL-tartH = DL-Tartaric Acid, DL-tartaric acid); the zirconium-based polyacid derivative belongs to the monoclinic crystal system, space group is P 21 / c Cell parameters a = 24.399(9) Å, b =15.301(5) Å, c = 26.941(8) Å, α=90°, β=104.794(7)°, γ=90°, V = 9724(6) Å 3 , Z = 2, R1=0.0876, wR 2 = 0.1708.
[0007] A method for preparing the above-mentioned organic-inorganic hybrid zirconium-based polyacid derivative, comprising DL-tartaric acid, sodium tungstate, dimethylamine hydrochloride, and Na₂[SbW₁₉O₂]₂. 33 Dissolve 19.5H2O in distilled water and stir for 10-30 min. Add ZrOCl2·8H2O and stir for 10-30 min at room temperature. Adjust the pH to 3.0-3.5 and then heat at 85 ± 5℃ for 1.5-2 h. After the reaction is complete, cool and filter. Let the filtrate stand (approximately 15-22 days) to precipitate colorless blocky crystals, which are the organic-inorganic hybrid zirconium-based polyacid derivatives.
[0008] Specifically, in the preparation process, DL-tartaric acid, sodium tungstate, and Na₂[SbW₁₈O₂] are used. 33 The molar ratio of 19.5H2O, ZrOCl2·8H2O, and dimethylamine hydrochloride can be 100:91:15-20:29-30:580-600. Among them, the polyacid precursor Na9[SbW9O] 33 19.5H2O can be prepared according to the literature (M. Boesing, I. Loose, H. Pohlmann, et al. Chemistry - A European Journal, 1997, 3(43): 1232-1237).
[0009] Furthermore, the pH value can be adjusted to maintain at 3.0-3.5 by adding 1-3 mol / L HCl.
[0010] This invention provides the application of the above-mentioned organic-inorganic hybrid zirconium-based polyacid derivatives as photochromic materials.
[0011] Furthermore, the present invention also provides the application of the above-mentioned organic-inorganic hybrid zirconium-based polyacid derivatives as reversible photochromic materials.
[0012] The organic-inorganic hybrid zirconium-based polyoxometalate derivative of this invention exhibits rapid and reversible photochromism; therefore, this invention also provides its application as a reversible photochromic material. Experiments have shown that the photochromic mechanism mainly involves W within the polyoxometalate tungsten cluster. 6+ →W 5+ This is caused by charge transfer. The target product of this invention has good, rapid, and reversible photochromic properties. However, the fading rate of the sample after photochromism is greatly affected by the surrounding environment, and the fading rate varies at different temperatures or with different oxygen concentrations.
[0013] This invention synthesizes an organic-inorganic hybrid zirconium-based polyacid derivative using a self-assembly synthesis strategy, comprising DL-tartaric acid, sodium tungstate, dimethylamine hydrochloride, and Na₂[SbW₁₉O₂]. 3319.5H2O is dissolved in water in a certain proportion, and ZrOCl2·8H2O is added. The ligand tartaric acid, as a carboxylic acid, can react with Zr. 4+ The ions coordinate with each other, thus protecting Zr. 4+ The role of ions to prevent Zr 4+ Ions hydrolyze in aqueous solution; polyacid precursor Na9[SbW9O] 33 19.5H2O reacts with sodium tungstate to assemble new polyacid building blocks at different pH values, and then reacts with Zr. 4+ The ions react with carboxylic acids to form stable zirconium polyacid derivatives through bonding and bridging.
[0014] Compared with traditional polyacid-based color-changing materials, the organic-inorganic hybrid zirconium-based polyacid derivatives of this invention have the following advantages:
[0015] 1) This invention uses X-ray single-crystal diffraction technology to accurately characterize and analyze the crystal structure of the target product;
[0016] 2) This invention employs a synthesis strategy of self-assembly in aqueous solution, which is simple to operate, safe to operate, low in energy consumption, and has a high yield.
[0017] 3) This invention investigated the solid-state diffuse reflectance changes during the photochromic process of organic-inorganic hybrid zirconium-based polyacid derivatives, and found that a deep blue color visible to the naked eye was achieved after 150 seconds of light irradiation.
[0018] 4) This invention investigates the effect of ambient temperature on the fading of photochromic zirconium-based polyacid derivative samples with organic-inorganic hybrid structure, providing experimental basis and theoretical reference for the potential application of this photochromic material.
[0019] 5) Compared with the photochromic rate of existing polyacid derivatives, the photochromic rate of the target product of this invention, the organic-inorganic hybrid zirconium-based polyacid derivative, is greatly improved, and it also exhibits excellent photochromic properties under simulated sunlight and visible light.
[0020] 6) Dissolve the target product 1, an organic-inorganic hybrid zirconium-based polyacid derivative, in water, and evenly coat the solution onto 7cm cellulose filter paper. Irradiate it with a 300W xenon lamp. A noticeable blue change can be observed, thus achieving inkless printing. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the ball-and-stick design of the anion structure of target product 1. It shows the tartaric acid-modified Zr. 4+ Ions are inserted into two disordered W and Zr [SbW] atoms. 17 ZrO 58 ] 7- The building blocks form the target product of sandwich-type dimer anions;
[0022] Figure 2 These are the infrared spectra of the original sample, the discolored sample, and the faded sample of target product 1. This demonstrates that the skeleton of target product 1 remains consistent with the original sample after photochromism and fading.
[0023] Figure 3 The images show the simulated XRD pattern of target product 1, the XRD pattern of the sample before photochromism, and the XRD pattern of the sample after fading at room temperature. This demonstrates that the structural framework of target product 1 remains unchanged after photochromic fading.
[0024] Figure 4 This is the TGA chart of target product 1;
[0025] Figure 5 This is a diagram showing the photochromic and fading process of target product 1 at room temperature. Similar infrared spectra confirm that target product 1 exhibits photochromic properties at room temperature.
[0026] Figure 6 This is a diagram showing the fading process of target product 1 after photochromism at 50 ℃ and 80 ℃. It demonstrates that the fading process of the sample after photochromism of target product 1 is affected by ambient temperature.
[0027] Figure 7 The infrared spectrum of target product 1 at 20-200 °C proves that target product 1 has good thermal stability.
[0028] Figure 8 The time-resolved solid diffuse reflection diagram of target product 1 under simulated sunlight irradiation using a 300W xenon lamp CEL-Am1.5 filter;
[0029] Figure 9 The photochromic dynamics of the target product under simulated sunlight irradiation using a 300W xenon lamp CEL-Am1.5 filter showed that the color change process can be divided into two stages: the first stage has a faster color change rate and the second stage has a slower color change rate.
[0030] Figure 10 The difference in color depth after applying solutions of target product 1 at different concentrations onto cellulose filter paper and irradiating them with a 300W xenon lamp is as follows:
[0031] Figure 11 The target product 1 was dissolved in water, and the solution was evenly coated onto 7 cm cellulose filter paper. When irradiated with a 300W xenon lamp, a noticeable blue change was observed, which turned colorless after 150 minutes. Specific implementation methods
[0032] The present invention will be further described in detail below through implementation, but this is not a limitation of the present invention. Various modifications and improvements can be made according to the basic idea of the present invention, but as long as they do not depart from the basic idea of the present invention, they are all within the scope of the invention.
[0033] In the following examples, all raw materials used are commercially available products that can be directly purchased or prepared using conventional methods in the art. Room temperature refers to 25±5℃.
[0034] Example 1:
[0035] An example of an organic-inorganic hybrid zirconium-based polyacid derivative, with the molecular formula [H2(CH3)2N]. 10 H8[Zr(DL-tartH)2(SbW 17 ZrO 58 )2]·36H2O (DL-tartH = DL-Tartaric Acid).
[0036] The preparation method of the above-mentioned organic-inorganic hybrid zirconium-based polyacid derivative includes the following steps:
[0037] 1) The ligand DL-tartaric acid (0.15 g, 1.0 mmol), sodium tungstate (0.30 g, 0.910 mmol), and polyacid precursor Na9[SbW9O] were added. 33 ·19.5H2O (0.56 g, 0.196 mmol) and dimethylamine hydrochloride (0.48 g, 5.88 mmol) were dissolved in 20 mL of distilled water and stirred for 20 min. Then, ZrOCl2·8H2O (0.096 g, 0.298 mmol) was added and stirred at room temperature for 20 min. The pH was then adjusted to 3.5 with 1 mol / L HCl aqueous solution.
[0038] 2) Place the solution obtained in step 1) into a water bath at 90°C and heat with stirring for 2 hours. After the reaction is complete, remove the solution, cool it to room temperature, filter it, and let the filtrate stand for three weeks to slowly evaporate. Colorless blocky crystals will then precipitate, which is the target product 1, an organic-inorganic hybrid zirconium polyacid derivative.
[0039] Example 2:
[0040] The target product 1 was irradiated under a 300W xenon lamp for 3 min, and the color of the target product 1 changed from colorless to dark blue; then, under dark conditions, the discolored sample was placed in air at room temperature for 18 h to restore it to colorless.
[0041] Example 3:
[0042] The fading of the discolored target product 1 is greatly affected by the ambient temperature. The discolored target product 1 returns to colorless after being placed at 50±5℃ for 10 hours; the discolored target product 1 returns to colorless after being placed at 80±5℃ for 7 hours.
[0043] Example 4
[0044] Dissolve 50 mg of target product 1 in 3 mL of water, and evenly spread the solution onto 7 cm cellulose filter paper. Allow it to air dry. Repeat the above steps until all 3 mL of solution is coated onto the filter paper. Using a template, irradiate the cellulose filter paper with a 300W xenon lamp. A noticeable blue change will be observed; the color deepens with increasing concentration of the target product, achieving inkless printing. Place the irradiated cellulose filter paper in a dark environment; it will return to colorless after 150 minutes (see [link to product description]). Figure 10 ).
[0045] The present invention uses X-ray single-crystal diffraction technology to determine and characterize the crystal structure of the target product 1 prepared in Example 1 above. Its unit cell parameters are as follows: monoclinic crystal system, space group . P 21 / c Cell parameters a = 24.399(9) Å, b = 15.301(5) Å, c = 26.941(8) Å, α = 90°, β = 104.794(7)°, γ = 90°, V = 9724(6) Å 3 , Z =2, R 1 = 0.0876, wR 2 = 0.1708.
[0046] Figure 1 A schematic diagram of the ball-and-stick assembly showing the anion structure of target product 1. Figure 1 It can be seen that: target product 1 consists of a dimer Zr(DL-tartH)2(SbW 17 ZrO 58 )2 18- Ionic framework, 10 H2(CH3)N + Composed of counteracting cations and 36 lattice water molecules, along with 8 H atoms + Protons are directly added to the polyanion to achieve charge balance. H + The addition of protons coincides with an acidic reaction environment (pH 3.5). Dimeric Zr(DL-tartH)₂[SbW 17 ZrO 58 ]218- The ion can be considered as consisting of two disordered [SbW] ions. 17 ZrO 58 ] 7- Fragments and organic-inorganic hybrids of [Zr(DL-tartH)2] 4‒ It is composed of fragments. [Zr(DL-tartH)2] 4- It can be viewed as being composed of a Zr 4+ The ion is formed by the chelation of two tartaric acid ligands through the O atom of the carboxyl group and the O atom of the hydroxyl group. Two (SbW 17 ZrO 58 ) 7- The fragment is composed of [SbW9O] 33 ] 9‒ The precursor and sodium tungstate are reassembled in an acidic environment, through the coordination of oxygen and tungsten atoms of the tartaric acid ligand, resulting in the formation of two [SbW] atoms. 17 ZrO 58 ] 7‒ With [Zr(DL-tartH)2] 2‒ They are interconnected (see Figure 1 ).
[0047] Figure 2 These are the infrared spectra of the original sample, the discolored sample, and the faded sample of target product 1. Figure 2 It can be seen that the original sample, the discolored sample, and the faded sample of target product 1 have similar infrared spectra in the range of 700–1100 cm⁻¹. ‒1 Within the range corresponding to the {SbW9} polyacid skeleton ν (W–Ot) (954 cm -1 ), ν (W–Ob) (889 cm -1 )and ν (W–Oc) (759 cm -1 Stretching vibration. At 3160 cm -1 and 1620 cm -1 The absorption peak at this point corresponds to the tartaric acid ligand in the tartaric acid ligand. ν (C–H) and ν (C=O) Symmetrical stretching vibration, 1466 cm⁻¹ -1 The strong absorption peak is attributed to [H2(CH3)2N]. + In cations ν (C–N) stretching vibration. Infrared spectroscopy analysis and single-crystal diffraction analysis results are consistent, confirming that target product 1 contains a polyacid framework and tartaric acid ligands, as well as [H2(CH3)2N]. + Counter cations (see Figure 2 ).
[0048] Figure 3 These are the simulated XRD patterns of target product 1, the XRD patterns of the sample before photochromism, the XRD patterns of the sample after photochromism, and the XRD patterns of the sample after fading at room temperature. Figure 3 It can be seen that the XRD patterns of the target product 1 before photochromism, after photochromism, and after fading at room temperature have similar peak positions compared with the simulated XRD. The difference in peak intensity may be due to the different preferential orientation of the XRD peaks of the target product 1 during the collection process (see...). Figure 3 ).
[0049] Figure 4 This is the TGA plot of target product 1. From 25℃ to 154℃, the TGA curve shows a weight reduction of approximately 6.66% (theoretical value: 6.63%) in one step, corresponding to the release of lattice water molecules. Therefore, the number of lattice water molecules is approximately 36. [H2(CH3)2N] 10 H8[Zr(DL-tartH)2(SbW 17 ZrO 58 Elemental analysis of [2]·36H2O: Mr = 9780.22 g·mol -1 Theoretical values (%): C, 3.44; N, 1.43; H, 1.68. Measured values: C, 3.27; N, 1.53; H, 1.73.
[0050] Figure 5 This is a diagram showing the photochromic and fading process of target product 1 at room temperature. Figure 6 This is a diagram showing the fading process of target product 1 after photochromism under conditions of 50℃ and 80℃. Figure 5 and 6 It can be seen that: under the irradiation of a 300 W ultraviolet xenon lamp, the sample of target product 1 gradually changes from colorless to deep blue with increasing irradiation time, realizing its color change process (see...). Figure 5 After discoloration, the sample returned to its original colorless state after 18 hours in air at room temperature. At 50 °C, the sample returned to its original colorless state after 10 hours; at 80 °C, it returned to its original colorless state after 7 hours (see...). Figure 6 Investigating the effect of ambient temperature on the fading process provides a theoretical basis and experimental foundation for the potential applications of this photochromic material. The thermal stability of target product 1 was investigated at different temperatures ranging from 20 to 200 °C, showing that the framework of target product 1 remains stable at 200 °C (see...). Figure 7 This demonstrates that target product 1 has good thermal stability.
[0051] Figure 8 This is a time-resolved solid-state diffuse reflectance map of target product 1 under 300 W xenon lamp irradiation. Figure 8 It can be seen that in the solid diffuse reflectance diagram showing the change with xenon lamp irradiation time, the spectral band gap of target product 1 (2.91 eV) is higher than that of the sample after 150 s of xenon lamp irradiation (2.86 eV), and the ultraviolet absorption intensity at approximately 700 nm gradually increases, which is attributed to W 6+ →W 5+ The occurrence of charge transfer proves that target product 1 can undergo photochromism (see...). Figure 8 ).
[0052] Figure 9 This describes the photochromic kinetics of target product 1 under 300 W xenon lamp irradiation. Figure 9 This indicates that the color-changing process can be divided into two stages: the first stage has a faster color-changing rate, and the second stage has a slower color-changing rate.
[0053] Figure 10 It is to combine different concentrations (3.41×10) -3 mol / L, 1.70×10 -3 The color depth of a solution of target product 1 (mol / L) applied to cellulose filter paper after irradiation with a 300W xenon lamp at different times (0-240s). Figure 10 The results showed that the higher the concentration of the target product, the darker the color.
[0054] Figure 11 The changes were observed after dissolving 50 mg of target product 1 in 2 mL of distilled water to prepare a 0.00256 mol / L solution, coating it onto cellulose filter paper, and irradiating it with a 300W xenon lamp. From... Figure 11 As can be seen, the stained cellulose filter paper showed a distinct blue color, which returned to colorless after 150 minutes.
[0055] In summary, the target product of this invention, an organic-inorganic hybrid zirconium-based polyacid derivative, has a high photochromic rate and exhibits excellent photochromic properties under simulated sunlight and visible light. It can be used as a photochromic material, especially a reversible photochromic material.
Claims
1. An organic-inorganic hybrid zirconium-based polyacid derivative, characterized in that, The zirconium-based polyacid derivative has the molecular formula [H2N(CH3)2]. 10 H8[Zr(DL-tartH)2(SbW 17 ZrO 58 )2]·36H2O, wherein DL-tartH is DL-tartaric acid; the zirconium-based polyacid derivative belongs to the monoclinic crystal system, space group is P 21 / c Cell parameters a = 24.399(9) Å, b = 15.301(5)Å, c = 26.941(8) Å, α=90°, β=104.794(7)°, γ=90°, V = 9724(6) Å 3 , Z = 2, R1 = 0.0876, wR 2 = 0.1708.
2. The method for preparing the organic-inorganic hybrid zirconium-based polyacid derivative according to claim 1, characterized in that, DL-tartaric acid, sodium tungstate, dimethylamine hydrochloride, and Na₂[SbW₁₉O₂]₂ were added. 33 Dissolve 19.5H2O in distilled water and stir for 10-30 min. Add ZrOCl2·8H2O and stir for 10-30 min at room temperature. Adjust the pH to 3.0-3.5 and then heat at 85 ± 5℃ for 1.5-2 h. After the reaction is complete, cool and filter. Let the filtrate stand and colorless blocky crystals will precipitate, which are the organic-inorganic hybrid zirconium-based polyacid derivatives.
3. The method for preparing the organic-inorganic hybrid zirconium-based polyacid derivative as described in claim 2, characterized in that, DL-tartaric acid, sodium tungstate, Na₂[SbW₁₈O₂] 33 The molar ratio of 19.5H2O and ZrOCl2·8H2O is 100:91:15-20:29-30.
4. The method for preparing the organic-inorganic hybrid zirconium-based polyacid derivative as described in claim 2, characterized in that, The pH value was adjusted to be maintained at 3.0-3.5 by adding 1-3 mol / L HCl dropwise.
5. The application of the organic-inorganic hybrid zirconium-based polyacid derivative of claim 1 as a photochromic material.
6. The application of the organic-inorganic hybrid zirconium-based polyacid derivative of claim 1 as a reversible photochromic material.