An organic-inorganic metal halide crystal material, a preparation method and application thereof

Abstract

The application relates to the field of functional materials, in particular to an organic-inorganic metal halide crystal material, a preparation method and application. The structural formula of the organic-inorganic metal halide crystal material is (C6H 14 N)2BiCl5, the space group is P na21 , the cell parameters are as follows: a =12.566±0.003Å, b =21.762±0.007Å, c =7.567±0.001Å, a = b = g =90°, Z =4, V =2069.40±0.06Å 3 . The application first obtains the organic-inorganic metal halide crystal material (C6H 14 N)2BiCl5, the crystal material has good nonlinear optical performance, the powder frequency doubling strength is about 0.85 times of KDP, the frequency doubling laser output of an Nd:YAG (1064nm) laser can be realized, and the crystal material is expected to be applied to an infrared solid laser.

Description

Technical Field

[0001] This invention relates to the field of functional materials, and more particularly to an organic-inorganic metal halide crystal material, its preparation method, and its application. Background Technology

[0002] Nonlinear optical crystals are crystals that exhibit second-order or higher nonlinear optical effects in response to strong electric fields from lasers. They are functional materials widely used in the field of laser technology. Nonlinear optical effects refer to effects such as frequency doubling, sum-frequency generation, difference-frequency generation, and parametric amplification. Only crystals with a non-symmetric center can exhibit nonlinear optical effects. Among them, frequency-doubling (or "frequency-conversion") crystals can be used to convert the laser wavelength, thereby expanding the tunable range of lasers, and have important application value in the field of laser technology.

[0003] Currently widely used nonlinear optical crystals include KH₂PO₄ (KDP), NH₄H₂PO₄ (ADP), KTiOPO₄ (KTP), BaB₂O₄ (BBO), and LiB₃O₅ (LBO). Frequency conversion techniques such as frequency doubling, mixing, parametric oscillation, and optical parametric amplification, generated by second-order nonlinear effects, can broaden the wavelength range of lasers and have been applied in nuclear fusion, medicine, underwater photography, optical communication, and optical ranging. These researches and applications have placed higher and more numerous demands on the physical and chemical properties of nonlinear optical crystals, and have also promoted the rapid development of nonlinear optical materials. Second-order organic-inorganic metal halide crystal materials must possess a non-centrosymmetric structure. Therefore, the design and synthesis of easily prepared and stable organic-inorganic metal halide crystal materials remain a hot research topic in this field. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide an organic-inorganic metal halide crystal material, a preparation method and an application, aiming to provide a new organic-inorganic metal halide crystal material.

[0005] The technical solution of the present invention is as follows: In a first aspect, the present invention provides an organic-inorganic metal halide crystal material having the structural formula (C6H12H2O) 14 N)2BiCl5.

[0006] Optionally, the space group of the organic-inorganic metal halide crystal material is P. na21 The unit cell parameters are: a =12.566±0.003Å, b = 21.762±0.007Å, c = 7.567±0.001Å, α = β = γ = 90°, Z = 4,V = 2069.40±0.06Å 3 .

[0007] Secondly, the present invention provides a method for preparing organic-inorganic metal halide crystal materials, comprising the following steps: Bismuth trioxide and hydrochloric acid were mixed and stirred to dissolve, forming a colorless and transparent solution. Then, 3-methylpiperidine was added, and the mixture was stirred and heated to 60-80°C until the reaction was complete. Subsequently, the mixture was evaporated and crystallized to obtain the organic-inorganic metal halide crystal material. The molar ratio of bismuth trioxide, HCl hydrochloric acid, and 3-methylpiperidine is 1:30-40:4.

[0008] Optionally, the evaporation and crystallization temperature is 25-35℃.

[0009] Thirdly, the present invention provides the application of the organic-inorganic metal halide crystal material in second-order nonlinear optical crystal materials. Optionally, the second-order organic-inorganic metal halide crystal material is an infrared solid-state laser.

[0010] Beneficial effects: This invention provides an organic-inorganic metal halide crystal material, its preparation method, and its application. This invention is the first to obtain an organic-inorganic metal halide crystal material (C6H... 14 N:2BiCl5 crystal exhibits excellent nonlinear optical properties, with a powder frequency doubling intensity of approximately 0.85 times KDP, enabling frequency-doubled laser output in Nd:YAG (1064nm) lasers. It holds promise for applications in infrared solid-state lasers.

[0011] The preparation method of the present invention is simple, the reaction conditions are mild, and the crystal material obtained is of high purity and the crystal is easy to grow to obtain large-size single crystals, which are suitable for making laser frequency doublers and can be used to prepare nonlinear optical devices. Attached Figure Description

[0012] Figure 1 This is an atomic packing diagram (c-axis direction) of a second-order organic-inorganic metal halide crystal material according to an embodiment of the present invention.

[0013] Figure 2 This is an atomic packing diagram (a-axis direction) of a second-order organic-inorganic metal halide crystal material according to an embodiment of the present invention.

[0014] Figure 3 This is a powder X-ray diffraction pattern of a second-order organic-inorganic metal halide crystal material according to an embodiment of the present invention.

[0015] Figure 4The Fourier transform infrared spectrum of the second-order organic-inorganic metal halide crystal material according to an embodiment of the present invention is shown.

[0016] Figure 5 This is a powder frequency doubling effect diagram of a second-order organic-inorganic metal halide crystal material according to an embodiment of the present invention. Detailed Implementation

[0017] This invention provides an organic-inorganic metal halide crystal material, its preparation method, and its applications. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] Although there are many usable organic and inorganic metal halide crystal materials, such as KTP (potassium titanate phosphate) for green light output and BBO (barium metaborate) for ultraviolet light output, they are not a panacea and each has obvious shortcomings, such as: Incomplete spectral coverage: Some materials perform well in a certain wavelength band, but perform poorly or are completely unusable in key wavelength bands such as deep ultraviolet (<200 nm) and mid-far infrared (>5 μm). For example, many oxide crystals have strong absorption in the infrared band and cannot be used for infrared laser output.

[0019] Limited power handling capacity: With the development of high-energy laser weapons, laser fusion and other fields, laser power is getting higher and higher. Traditional materials are easily damaged (low optical damage threshold), generate heat leading to performance degradation (thermal lensing effect), or even explode under high-power laser irradiation.

[0020] Transmission range and phase matching: The transmission range of a material itself limits the laser wavelengths it can handle. Simultaneously, achieving efficient frequency conversion requires phase matching, which necessitates a specific birefringence in the material. Many materials cannot simultaneously meet both conditions at the desired wavelength.

[0021] Insufficient physical and chemical stability: Some crystals are prone to deliquescence (such as some ultraviolet crystals), have insufficient hardness, are difficult to process, or cannot grow large-size, high-quality single crystals, all of which limit their practical applications.

[0022] Current research in quantum communication and quantum computing requires entangled photon pairs, which are typically generated through spontaneous parametric down-conversion processes in crystals. Developing novel crystals could enable more efficient and controllable generation of entangled light sources with specific wavelengths and properties.

[0023] Based on this, this embodiment provides an organic-inorganic metal halide crystal material with the structural formula (C6H). 14 N)2BiCl5.

[0024] In one specific embodiment, the space group of the organic-inorganic metal halide crystal material is P. na21 Its unit cell parameters are: a = 12.566±0.003Å, b = 21.762±0.007Å, c = 7.567±0.001Å, α = β = γ = 90°, Z = 4, V = 2069.40±0.06Å 3 .

[0025] The structure of the obtained crystal was analyzed by X-ray single-crystal diffraction. The X-ray single-crystal diffraction results showed that the chemical formula of the compound is C. 12 H 28 N₂BiCl₅, at room temperature (293 K), belongs to the orthorhombic crystal system, space group P. na21 Its unit cell parameters are: a = 12.566±0.003Å, b = 21.762±0.007Å, c = 7.567±0.001Å, α = β = γ =90°, Z = 4, V = 2069.40±0.06Å 3 .

[0026] Figure 1 This is a schematic diagram of the atomic packing projection along the c-axis of the crystal structure. Figure 2 This is a schematic diagram of the atomic packing projection along the a-axis of the crystal structure. From... Figure 1 , Figure 2 It can be seen that each Bi atom is connected to 6 Cl atoms to form a BiCl6 octahedral anionic framework structure. The octahedra are connected by Cl atoms sharing vertices to form a one-dimensional Z-shaped chain structure. This arrangement of one-dimensional chains along the c-axis of the anionic framework is beneficial to increasing the polarity of the compound, thus resulting in nonlinear optical properties. The cations are connected to the anionic framework through NH···Cl and CH···Cl hydrogen bonds, forming a one-dimensional chain structure along the c-axis.

[0027] It should be noted that the X-ray single-crystal diffraction was performed on a Rigaku XtaLABSynergy-R CCD X-ray single-crystal diffractometer. The data collection temperature was 293 K, the diffraction source was Cu-Kα rays (λ = 1.542 Å), and the scanning mode was ω-2θ. The data underwent absorption correction using the Multi-Scan method. Structural analysis was performed using the SHELXTL-97 software package; the positions of heavy atoms were determined using the direct method, and the coordinates of the remaining atoms were obtained using the difference Fourier synthesis method; the structure was analyzed using F-based... 2 The full matrix least squares method is used to refine the coordinates and anisotropic thermal parameters of all atoms.

[0028] Secondly, the present invention provides a method for preparing organic-inorganic metal halide crystal materials, comprising the following steps: Bismuth trioxide and hydrochloric acid were mixed and stirred to dissolve, forming a colorless and transparent solution. Then, 3-methylpiperidine was added, and the mixture was stirred and heated to 60-80°C until the reaction was complete. Subsequently, the mixture was evaporated and crystallized to obtain the organic-inorganic metal halide crystal material. The molar ratio of bismuth trioxide, HCl hydrochloric acid, and 3-methylpiperidine is 1:30-40:4.

[0029] In the preparation method of this embodiment, bismuth trioxide (Bi₂O₃) is dissolved by hydrochloric acid (HCl) to generate Bi₂O₃. 3+ With Cl - The final product is a bismuth chloride complex anion. This step provides the inorganic framework unit, the bismuth halide anion. The excess HCl in the hydrochloric acid provides an acidic environment, facilitating the protonation of the amine matrix in the next step. The subsequently added 3-methylpiperidine, a cyclic secondary amine with strong basicity, is protonated by the HCl in the bismuth chloride complex anion, forming an organic cation. The protonated organic cation combines with the bismuth chloride anion through electrostatic interactions, forming an ionic crystal, ultimately yielding the organic-inorganic metal halide crystal material of this invention. Only within a suitable temperature range can the protonated organic cation and the bismuth chloride anion effectively combine to form an ionic crystal, which is beneficial for forming high-quality crystals of this invention.

[0030] It should be noted that the preparation method of the present invention is simple, the reaction conditions are mild, and the crystal material obtained is of high purity. If appropriate methods and conditions are used, it is expected to prepare large-size single crystals, which are suitable for making laser frequency doublers and can be used to prepare nonlinear optical devices.

[0031] In one specific embodiment, the evaporation and crystallization temperature is 25-35°C.

[0032] Thirdly, the present invention provides the application of the organic-inorganic metal halide crystal material in second-order nonlinear optical crystal materials. The second-order organic-inorganic metal halide crystal material is an infrared solid-state laser.

[0033] The present invention will be further described below through specific embodiments.

[0034] Example 1 The method for preparing organic-inorganic metal halide crystal materials in this embodiment includes the following steps: Weigh 1.16g of bismuth trioxide and add it to 4.89g of hydrochloric acid. Mix and stir to dissolve to form a colorless and transparent solution. Then add 0.75g of 3-methylpiperidine and stir to allow it to react completely. Heat to 60℃ and stir to obtain a colorless and transparent solution. The resulting solution is then slowly evaporated and crystallized at 25℃.

[0035] The crystal obtained in this embodiment was subjected to X-ray single-crystal diffraction testing, and the results showed that the chemical formula of the crystal was C. 12 H 28 BiCl5N2, at room temperature (293K), belongs to the orthorhombic crystal system, space group Pna21, with cell parameters a = 12.566(3) Å, b = 21.762(7) Å, c = 7.567(1) Å, α = β = γ = 90°, Z = 4, V = 2069.40(6) Å. 3 .

[0036] Powder X-ray diffraction tests were performed on a Bruker D8 Advance X-ray powder diffractometer. The test conditions were: fixed target monochromatic light source Cu-Kα, wavelength 1.540598 Å, scanning range 5–50°, and scanning step size 0.2°. Figure 3 The results of powder X-ray diffraction (PXRD) testing are shown, along with the X-ray diffraction patterns obtained by fitting the single-crystal structure. Comparison of the two patterns reveals that the positions and intensities of the diffraction peaks are essentially consistent. The PXRD results are in high agreement with the theoretically simulated patterns, indicating that the experimentally prepared compound is free of impurities and of high purity, providing a common material guarantee for subsequent crystal performance testing.

[0037] The crystal (C6H) was analyzed using a Bruker VERTEX 70 Fourier transform infrared spectrometer. 14 Fourier transform infrared (FTIR) spectroscopy was performed on N)2BiCl5, with a scanning range of 400 cm⁻¹. -1 Up to 4000 cm -1 The results are as follows Figure 4 As shown, at 3452cm -1 The peak shown corresponds to the stretching vibration peak of NH at 3165 cm⁻¹. -1The peak shown corresponds to the stretching vibration peak of CH in methyl groups, at 3048 cm⁻¹. -1 The peak shown corresponds to the stretching vibration peak of CH on the benzene ring, at 1638 cm⁻¹. -1 The peak shown corresponds to the C=C stretching vibration peak in the benzene ring, 1200-1000 cm⁻¹. -1 The peak shown corresponds to the stretching vibration peak of CN in pyridine. The infrared analysis results are consistent with the functional groups of the single crystal structure, indicating that the prepared crystal has high purity.

[0038] A 1064nm wavelength laser generated by a Q-switched Nd:YAG solid-state laser with a frequency converter was used as the fundamental frequency light to irradiate the obtained crystal powder. The generated second harmonic was detected using a photomultiplier tube, and the harmonic intensity was displayed on an oscilloscope. Under the same test conditions, KH₂PO₄ (KDP) was used as a reference sample, and the results are as follows. Figure 5 As shown, the test results indicate that this crystal (C6H) 14 The powder SHG coefficient of N)2BiCl5 under 1064nm laser irradiation is 0.85 times that of KH2PO4(KDP).

[0039] Example 2 The method for preparing organic-inorganic metal halide crystal materials in this embodiment includes the following steps: Weigh 1.16 g of bismuth trioxide and add it to 4.89 g of hydrochloric acid. Mix and stir to dissolve to form a colorless and transparent solution. Then add 0.75 g of 3-methylpiperidine and stir to allow it to react completely. Heat to 65 °C and stir to obtain a colorless and transparent solution. The resulting solution is then slowly evaporated and crystallized at 25 °C.

[0040] The crystal obtained in this embodiment is the same as the crystal obtained in Example 1.

[0041] Example 3 The method for preparing organic-inorganic metal halide crystal materials in this embodiment includes the following steps: Weigh 1.16 g of bismuth trioxide and add it to 4.89 g of hydrochloric acid. Mix and stir to dissolve to form a colorless and transparent solution. Then add 0.75 g of 3-methylpiperidine and stir to allow it to react completely. Heat to 70 °C and stir to obtain a colorless and transparent solution. The resulting solution is then slowly evaporated and crystallized at 25 °C.

[0042] The crystal obtained in this embodiment is the same as the crystal obtained in Example 1.

[0043] Example 4 The method for preparing organic-inorganic metal halide crystal materials in this embodiment includes the following steps: Weigh 1.16 g of bismuth trioxide and add it to 4.89 g of hydrochloric acid. Mix and stir to dissolve to form a colorless and transparent solution. Then add 0.75 g of 3-methylpiperidine and stir to allow it to react completely. Heat to 75 °C and stir to obtain a colorless and transparent solution. The resulting solution is then slowly evaporated and crystallized at 25 °C.

[0044] The crystal obtained in this embodiment is the same as the crystal obtained in Example 1.

[0045] Example 5 The method for preparing organic-inorganic metal halide crystal materials in this embodiment includes the following steps: Weigh 1.16 g of bismuth trioxide and add it to 4.89 g of hydrochloric acid. Mix and stir to dissolve to form a colorless and transparent solution. Then add 0.75 g of 3-methylpiperidine and stir to allow it to react completely. Heat to 80 °C and stir to obtain a colorless and transparent solution. The resulting solution is then slowly evaporated and crystallized at 25 °C.

[0046] The crystal obtained in this embodiment is the same as the crystal obtained in Example 1.

[0047] In summary, this invention provides an organic-inorganic metal halide crystal material, its preparation method, and its applications. This invention is the first to obtain an organic-inorganic metal halide crystal material (C6H... 14 N:2BiCl5 crystal exhibits excellent nonlinear optical properties, with a powder frequency doubling intensity of approximately 0.85 times KDP, enabling frequency-doubled laser output in Nd:YAG (1064nm) lasers. It holds promise for applications in infrared solid-state lasers.

[0048] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An organic-inorganic metal halide crystal material, characterized in that, The structural formula is (C6H 14 N)2BiCl5.

2. The organic-inorganic metal halide crystal material according to claim 1, characterized in that, The space group of the organic-inorganic metal halide crystal material is P. na21 The unit cell parameters are: a = 12.566±0.003Å, b =21.762±0.007Å, c = 7.567±0.001Å, α = β = γ = 90°, Z = 4, V = 2069.40±0.06Å 3 .

3. A method for preparing an organic-inorganic metal halide crystal material as described in claim 1 or 2, characterized in that, Includes the following steps: Bismuth trioxide and hydrochloric acid were mixed and stirred to form a colorless and transparent solution. Then, 3-methylpiperidine was added, and the mixture was stirred and heated to 60-80°C until the reaction was complete. Subsequently, the mixture was evaporated and crystallized to obtain the organic-inorganic metal halide crystal material. The molar ratio of bismuth trioxide, HCl hydrochloric acid, and 3-methylpiperidine is 1:30-40:

4.

4. The method for preparing organic-inorganic metal halide crystal materials according to claim 3, characterized in that, The evaporation and crystallization temperature is 25-35℃.

5. The application of an organic-inorganic metal halide crystal material as described in claim 1 or 2 in second-order nonlinear optical crystal materials.

6. The application according to claim 5, characterized in that, The second-order nonlinear optical crystal material is an infrared solid-state laser.

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