Trithiocyanuric acid aminoguanidine ultraviolet birefringent crystal as well as preparation method and application thereof
By designing tripolymer aminoguanidine tripolythiocyanate ultraviolet birefringent crystal-(CN4H7)H2C3N3S3, the problem of insufficient transmission range and birefringent index of existing ultraviolet birefringent crystal materials is solved, and the balance between large birefringent and wide transmission range is achieved, which is suitable for the preparation of miniaturized optical devices.
Patent Information
- Application Number
- CN202510572880.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2025-07-22
AI Technical Summary
The existing ultraviolet birefringent crystal materials have shortcomings in terms of transmission range and birefringence, which limits their application fields, especially the small birefringence of MgF2 and the α-BaB2O4 is prone to cracking during the growth of large-sized crystals.
The ultraviolet birefringent crystal of tripolymer thiocyanate--(CN4H7)H2C3N3S3 was designed and synthesized. By introducing (CN4H7)+ groups with wide band gap and significant anisotropic polarization, crystals with large birefringence and shorter UV cut-off edges were prepared by combining the weak interaction of the anionic group.
The balance of large birefringence and wide transmission range is achieved, and the ultraviolet cut-off edge blue shift is suitable for the preparation of miniaturized optical devices, such as optical isolators, circulators, beam displacements, optical polarizers and optical modulators, and has good chemical stability.
Smart Images
Figure CN120350436A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of optoelectronic functional materials, and particularly relates to a thiocyanuric acid aminoguanidine ultraviolet birefringent crystal, a preparation method thereof, and an application thereof. Background Art
[0002] When a light wave is projected onto the crystal interface, usually the birefringence phenomenon occurs, that is, two refracted light beams are generated. This phenomenon is caused by the anisotropy of the crystal. When light propagates in a crystal (except for crystals of the cubic crystal system), except along the optical axis direction, it will decompose into two polarized light beams with perpendicular vibration directions, different refractive indices, and unequal propagation speeds. Such a crystal is called a birefringent crystal. The birefringence property of a crystal is an important optical performance parameter of optoelectronic functional material crystals. Utilizing the characteristics of birefringent crystals, linearly polarized light can be obtained, and the displacement of light beams can be achieved, etc. Thus, birefringent crystals become the key materials for making optical elements such as optical isolators, circulators, beam displacers, optical polarizers, and optical modulators. Currently, the commercially widely used birefringent crystal materials mainly include α-BaB2O4, MgF2, etc. Although these crystal materials all have excellent properties, there are also some deficiencies that limit their application fields.
[0003] MgF2 is one of the birefringent crystal materials that can be applied to the deep ultraviolet. Its cut-off edge reaches 110 nm. However, its birefringence is very small (Δ n= 0.0128@253.7 nm), which greatly limits its application; the transmission range of the α-BaB2O4 crystal is 189 - 3500 nm, and the birefringence is relatively large. However, this crystal is prone to cracking during the growth process of large-sized crystals. Therefore, it is urgent to explore ultraviolet birefringent crystals with excellent comprehensive performance.
[0004] In recent years, the planar π-conjugated (HC3N3S3) − / (H2C3N3S3) − anionic group, due to its large anisotropic polarizability, has become an ideal unit for designing high-performance birefringent crystals. Moreover, the synthesis of thiocyanates can adopt mild synthesis methods (such as aqueous solution method, hydrothermal method), which is beneficial to the growth of large-sized and high-quality single crystals, providing a basis for the large-scale preparation of optical devices. Therefore, the present invention selects the planar π-conjugated (HC3N3S3) − / (H2C3N3S3) − anionic group to design and synthesize a new type of birefringent crystal with excellent optical performance. In addition to the contribution of the anionic group to birefringence, the contribution of the cation cannot be ignored. Recent extensive research shows that planar π-conjugated group cations can effectively increase the birefringence. Summary of the Invention
[0005] The technical problem solved by the present invention is to provide a thiocyanuric acid aminoguanidine ultraviolet birefringent crystal with a wide transmission range and a large birefringence, and a preparation method thereof. The crystal can be used as a birefringent crystal material in the ultraviolet band. The present invention selects (CN4H7) + group with a wide band gap (5.98 eV) and a significant anisotropic polarizability (21.68 a.u.) and introduces it into (HC3N3S3) − / (H2C3N3S3) − system. Furthermore, by utilizing the weak interaction between cationic and anionic groups, the functional groups are arranged in a favorable manner. Based on the above design concept, the present invention successfully designs and synthesizes the first metal-free thiocyanurate ultraviolet birefringent crystal - (CN4H7)H2C3N3S3. The crystal exhibits a balance of a large birefringence (0.319 @ 546.1 nm) and a short ultraviolet cut-off edge (336 nm). Its ultraviolet cut-off edge is significantly blue-shifted, and the birefringence is much higher than that of the reported (CN4H7) + -based compounds.
[0006] The present invention adopts the following technical solution to solve the above problems: A thiocyanuric acid aminoguanidine ultraviolet birefringent crystal, the chemical formula of the crystal is (CN4H7)H2C3N3S3, which has a centrosymmetric structure, the crystal structure belongs to the triclinic system, and the space group is , and the unit cell parameters a =6.7573(4) Å, b =8.7534(4) Å, c =8.9165(3) Å, α =91.103(3), β =92.980(4), γ =102.896(4), Z =2, and the unit cell volume is V =513.15(4) Å 3 . The crystal has a wide transmission range and a large birefringence, and can be used as a birefringent crystal material in the ultraviolet band.
[0007] Further defined, the experimental birefringence of the crystal is 0.221 @ 546.1 nm, the theoretical birefringence is 0.319 @ 546.1 nm, and its ultraviolet absorption edge is 336 nm.
[0008] The preparation method of the thiocyanuric acid aminoguanidine ultraviolet birefringent crystal described in the present invention specifically comprises the following steps: Mix the raw materials C2H8N4O3 and H3C3N3S3 or the raw materials C2H8N4O3, H3C3N3S3 and NaF evenly in a solvent, and then carry out a hydrothermal reaction at 80-100 °C to obtain the thiocyanuric acid aminoguanidine ultraviolet birefringent crystal.
[0009] It is further defined that when the raw materials are C2H8N4O3 and H3C3N3S3, the molar ratio of C2H8N4O3 to H3C3N3S3 is (1-6):1, preferably (1-1.1):1; when the raw materials are C2H8N4O3, H3C3N3S3 and NaF, the molar ratio of C2H8N4O3, H3C3N3S3 and NaF is (1-6):(1-1.1):(0.01-3.5), preferably 1:1:(0.1-3.2).
[0010] It is further defined that the solvent is deionized water, and the feeding ratio of the total mass of C2H8N4O3 and H3C3N3S3 or the total mass of C2H8N4O3, H3C3N3S3 and NaF to the solvent is (9-107) g:100 mL, preferably (75-107) g:100 mL.
[0011] It is further defined that the hydrothermal reaction temperature is 90° C., and the hydrothermal reaction time is (3 to 120) h, preferably (3 to 72) h.
[0012] Application of the aminoguanidine thiocyanate ultraviolet birefringent crystal of the present invention in optical devices.
[0013] It is further defined that the aminoguanidine thiocyanate ultraviolet birefringent crystal is used in the preparation of an optical isolator, a circulator, a beam displacer, an optical polarizer or an optical modulator.
[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The polarizing microscope of the present invention tests the birefringence of the (CN4H7)H2C3N3S3 ultraviolet birefringent crystal, and its birefringence is 0.221@546.1 nm, which shows that the aminoguanidine thiocyanate ultraviolet birefringent crystal prepared by the present invention has a large birefringence, and is significantly larger than the currently reported (CN4H7) + Based compounds are expected to achieve miniaturization of devices and expand the application range of trithiocyanate ultraviolet birefringent crystals; at the same time, its ultraviolet absorption edge is 336nm, so (CN4H7)H2C3N3S3 crystals can be used to prepare optical isolators, circulators, beam shifters, optical polarizers or optical modulators.
[0015] 2. The first metal-free (CN4H7)H2C3N3S3 ultraviolet birefringent crystal prepared by the present invention has the properties of being colorless, transparent, non-deliquescent, and having good chemical stability. Therefore, it is expected to be widely used in various optical fields, and will open up the application of ultraviolet birefringent crystal materials in the ultraviolet band to promote the development of related disciplines and industrial technologies.
[0016] 3. The purity and quality of the (CN4H7)H2C3N3S3 ultraviolet birefringent crystal prepared by selecting C2H8N4O3, H3C3N3S3 and NaF as raw materials in the present invention are significantly improved. Among them, NaF is used as a mineralizer, and F - ions increase the solubility of the target compound in the reaction system, promote the dissolution of small-sized or defective crystals, and drive the solute to recrystallize directionally on the surface of high-quality crystal nuclei. This process follows the Ostwald ripening principle and finally forms large-sized, low-defect single crystals. Moreover, F - is preferentially adsorbed on the high-energy crystal planes of the crystal, reducing its surface energy, and can effectively inhibit the twin defects caused by anisotropic growth. In addition, since trithiocyanuric acid mainly exists in four forms in water, namely (C3N3S3) 3- , (HC3N3S3) 2- , (H2C3N3S3) - and (H3C3N3S3), which form mainly exists depends mainly on the pH value of the aqueous solution. When pH > 12, it mainly exists in the form of (C3N3S3) 3- ; when pH = 8 - 10, it mainly exists in the form of (HC3N3S3) 2- ; when pH = 5 - 8, it mainly exists in the form of (H2C3N3S3) - ; when pH < 5, it mainly exists in the form of (H3C3N3S3). Therefore, in order to obtain the (H2C3N3S3) - group, the present invention selects to adjust the pH value to 5 - 8, preferably pH = 7, when using NaF as a mineralizer. In order not to introduce other impurity ions, NaOH and HCl are used to precisely adjust the reaction pH value, and the generated NaCl is also a mineralizer, which is beneficial to improving the crystal quality. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 is the X-ray powder diffraction pattern of the (CN4H7)H2C3N3S3 ultraviolet birefringent crystal prepared in Example 1.
[0018] Figure 2 is the schematic diagram of the unit cell structure of the (CN4H7)H2C3N3S3 ultraviolet birefringent crystal prepared in Example 1.
[0019] Figure 3 is the working principle diagram of a typical birefringent optical device made of the (CN4H7)H2C3N3S3 ultraviolet birefringent crystal prepared in Example 1, where 1 - first coupler, 2 - birefringent crystal, 3 - optical rotation material, 4 - second coupler.
[0020] Figure 4The UV-Vis-NIR diffuse reflectance spectrum of the (CN4H7)H2C3N3S3 UV birefringent crystal prepared in Example 1.
[0021] Figure 5 The theoretical birefringence curve of the (CN4H7)H2C3N3S3 UV birefringent crystal prepared in Example 1.
[0022] Figure 6 The experimental birefringence value of the (CN4H7)H2C3N3S3 UV birefringent crystal prepared in Example 1 at 546.1 nm. Detailed implementation manners
[0023] The above content of the present invention will be further described in detail through the following implementation cases, but it should not be understood that the scope of the above subject matter of the present invention is limited to the following examples. All technologies implemented based on the above content of the present invention belong to the scope of the present invention.
[0024] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods. In the following examples, an Empyrean X-ray powder diffractometer equipped with a Cu target was used to characterize the obtained (CN4H7)H2C3N3S3 single crystal; test conditions: room temperature. Example 1
[0025] (CN4H7)H2C3N3S3 single crystal was prepared by hydrothermal reaction Raw materials used for preparing (CN4H7)H2C3N3S3 single crystal: C2H8N4O3 0.749 g (0.0055 mol) H3C3N3S3 0.886 g (0.0050 mol) The specific operation steps are as follows: After weighing the above raw materials according to the above dosages, they are loaded into a 25 mL Teflon-lined autoclave, then 4 mL of deionized water is added, and then the mixture is subjected to hydrothermal reaction at 90 °C for 5 h. Finally, it is slowly cooled to room temperature, washed with ethanol, and dried in air to obtain the (CN4H7)H2C3N3S3 crystal.
[0026] The X-ray powder diffraction pattern of the (CN4H7)H2C3N3S3 single crystal prepared in this example is as Figure 1 shown. The results in the figure show that the (CN4H7)H2C3N3S3 single crystal obtained in this example is a single pure phase with high purity. The schematic diagram of its unit cell structure is as Figure 2 shown. The (CN4H7)H2C3N3S3 UV birefringent crystal has a centrosymmetric structure, the crystal structure belongs to the triclinic system, and the space group is , and the unit cell parameters area = 6.7573(4) Å, b = 8.7534(4) Å, c = 8.9165(3) Å, α = 91.103(3), β = 92.980(4), γ = 102.896(4), Z = 2, and the unit cell volume is V = 513.15(4) Å 3 ., Figure 4 is the ultraviolet-visible-near-infrared diffuse reflectance spectrum of the (CN4H7)H2C3N3S3 ultraviolet birefringent crystal prepared in this example. It can be seen from the figure that the ultraviolet absorption edge of the prepared (CN4H7)H2C3N3S3 ultraviolet birefringent crystal is 336 nm; Figure 5 is the theoretical birefringence curve of the (CN4H7)H2C3N3S3 ultraviolet birefringent crystal prepared in this example. It can be seen from the figure that the theoretical birefringence of the prepared (CN4H7)H2C3N3S3 ultraviolet birefringent crystal is 0.319@546.1 nm; Figure 6 is the experimental birefringence value of the (CN4H7)H2C3N3S3 ultraviolet birefringent crystal prepared in this example at 546.1 nm. It can be seen from the figure that the experimental birefringence of the prepared (CN4H7)H2C3N3S3 ultraviolet birefringent crystal is 0.221@546.1 nm. Example 2
[0027] A single crystal of (CN4H7)H2C3N3S3 was prepared by a hydrothermal reaction Raw materials used for preparing the (CN4H7)H2C3N3S3 single crystal: C2H8N4O3 0.749 g (0.0055 mol) H3C3N3S3 0.975 g (0.0055 mol) The specific operation steps are as follows: After weighing the above raw materials according to the above dosages, they are loaded into a 25 mL high-pressure hydrothermal autoclave with a polytetrafluoroethylene liner, then 4 mL of deionized water is added, and then the mixture is subjected to a hydrothermal reaction at 90 °C for 72 h. Finally, it is slowly cooled to room temperature, washed with ethanol, and dried in air to obtain the (CN4H7)H2C3N3S3 crystal.
[0028] The powder X-ray diffraction pattern of the crystal obtained in this example is consistent with the X-ray diffraction pattern simulated based on the (CN4H7)H2C3N3S3 single crystal structure, indicating that the obtained crystal is (CN4H7)H2C3N3S3 crystal. Example 3
[0029] (CN4H7)H2C3N3S3 single crystal was prepared by hydrothermal reaction Raw materials used for preparing (CN4H7)H2C3N3S3 single crystal: C2H8N4O3 0.749 g (0.0055 mol) H3C3N3S3 0.9754 g (0.0055 mol) NaF 0.210 g (0.005 mol) The specific operation steps are as follows: After weighing the above raw materials according to the above dosages, they are loaded into a 25 mL Teflon-lined autoclave, and then 2 mL of deionized water is added. The pH of the mixed system is adjusted to 7 with NaOH and HCl. Then the mixture is subjected to hydrothermal reaction at 90 °C for 3 h. Finally, it is slowly cooled to room temperature, washed with ethanol, and dried in air to obtain (CN4H7)H2C3N3S3 crystal.
[0030] The powder X-ray diffraction pattern of the crystal obtained in this example is consistent with the X-ray diffraction pattern simulated based on the (CN4H7)H2C3N3S3 single crystal structure, indicating that the obtained crystal is (CN4H7)H2C3N3S3 crystal. Example 4
[0031] (CN4H7)H2C3N3S3 single crystal was prepared by hydrothermal method Raw materials used for preparing single crystal: C2H8N4O3 7.49 g (0.055 mol) H3C3N3S3 9.75 g (0.055 mol) NaF 7.35 g (0.175 mol) The specific operation steps are as follows: After weighing the above raw materials according to the above dosages, they are loaded into a 100 mL Teflon-lined autoclave, and then 30 mL of deionized water is added. The pH of the mixed system is adjusted to 7 with NaOH and HCl. Then the mixture is subjected to hydrothermal reaction at 90 °C for 3 h. Finally, it is slowly cooled to room temperature, washed with ethanol, and dried in air to obtain (CN4H7)H2C3N3S3 crystal.
[0032] The powder X-ray diffraction pattern of the crystal obtained in this example is consistent with the X-ray diffraction pattern simulated based on the (CN4H7)H2C3N3S3 single crystal structure, indicating that the obtained crystal is (CN4H7)H2C3N3S3 crystal.
[0033] The above embodiments have described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention will have various changes and improvements, and all these changes and improvements fall within the scope of protection of the present invention.
Claims
1. Ammonium guanidine trithiocyanate ultraviolet birefringent crystal, characterized in that: The chemical formula of the crystal is (CN4H7)H2C3N3S3. It has a centrosymmetric structure. The crystal structure belongs to the triclinic system, and the space group is , and the unit cell parameters are a a = 6.7573(4) Å, b b = 8.7534(4) Å, c c = 8.9165(3) Å, α α = 91.103(3), β β = 92.980(4), γ γ = 102.896(4), Z Z = 2, and the unit cell volume is V V = 513.15(4) Å 3 . This crystal has a wide transmission range and a large birefringence, and can be used as a birefringent crystal material in the ultraviolet band.
2. The thiocyanuric acid aminoguanidine ultraviolet birefringent crystal according to claim 1, wherein: The experimental birefringence of the crystal is 0.221 @ 546.1 nm, and the theoretical birefringence is 0.319 @ 546.1 nm. Its ultraviolet absorption edge is 336 nm.
3. The preparation method of the thiocyanuric acid aminoguanidine ultraviolet birefringent crystal according to claim 1 or 2, characterized in that The specific preparation steps are as follows: After uniformly mixing the raw materials C2H8N4O3 and H3C3N3S3 or the raw materials C2H8N4O3, H3C3N3S3 and NaF in a solvent, perform a hydrothermal reaction at 80 - 100 °C to obtain the guanidine aminotritonate ultraviolet birefringent crystal.
4. The preparation method of the cyanuric acid aminoguanidine ultraviolet birefringent crystal according to claim 3, characterized in that: When the raw materials are C2H8N4O3 and H3C3N3S3, the molar ratio of the feed of C2H8N4O3 to C3H3N3S3 is (1 - 6):1; when the raw materials are C2H8N4O3, H3C3N3S3 and NaF, the molar ratio of the feed of C2H8N4O3, H3C3N3S3 to NaF is (1 - 6):(1 - 1.1):(0.01 - 3.5).
5. The preparation method of the cyanuric acid aminoguanidine ultraviolet birefringent crystal according to claim 3, characterized in that: The solvent is deionized water, and the feeding ratio of the total mass of C2H8N4O3 and H3C3N3S3 or the total mass of C2H8N4O3, H3C3N3S3 and NaF to the solvent is (9 - 107) g:100 mL.
6. The preparation method of the aminoguanidine trithiocyanurate ultraviolet birefringent crystal according to claim 3, characterized in that: The hydrothermal reaction temperature is 90 °C, and the hydrothermal reaction time is (3 - 120) h.
7. Application of the guanidine aminotritonate ultraviolet birefringent crystal according to claim 1 or 2 in optical devices.
8. Application of the guanidine aminotritonate ultraviolet birefringent crystal according to claim 1 or 2 in the preparation of optical isolators, circulators, beam displacers, optical polarizers or optical modulators.