Boron-oxygen molecular crystalline compound as well as preparation method and application thereof
By adding 4-methylpyrazole to react with boron-containing compounds under the induction of copper halide, the Cu4(B4O4)(Z)8X4 boron oxide crystalline compound is formed, which solves the difficult problem of synthesizing the [B4O4] boron oxide octagonal ring and realizes the efficient and stable synthesis of [B4O4] boron oxide crystalline compounds and the application of nonlinear optical materials.
Patent Information
- Application Number
- CN202410450801.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-15
- Publication Date
- 2025-10-21
AI Technical Summary
It is difficult to efficiently synthesize inorganic-organic hybrid functional materials with [B4O4] boron-oxygen octagonal ring as the central skeleton with existing technologies, and the process of transitioning the [B3O3] unit to the [B4O4] octagonal ring is complicated and difficult to form.
Under the induction of copper halide, 4-methylpyrazole is added as a N-containing donor to react with boron-containing compounds to form a Cu4(B4O4)(Z)8X4 boron-oxygen crystalline compound, which utilizes the B←N bond to form a stable [B4O4] central skeleton, and the 4-methylpyrazole ligand prevents the hydrolysis of [B4O4] borate ester.
A simple and efficient synthesis of [B4O4] boron oxide crystalline compounds has been achieved with a yield of over 70%, making it suitable for large-scale production. The material is stable in air and ethanol, exhibits good third-order nonlinear optical properties, and can be used as a nonlinear optical material.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of crystal material preparation, and in particular relates to a Cu4(B4O4)(Z)8X4 boron-oxygen molecule crystalline compound and a preparation method and application thereof. Background Art
[0002] Boric acid and its derivatives are an important class of compounds due to their widespread applications in organic synthesis, catalysis, medicinal chemistry, and optics. Boric acid and organoboronic acids readily condense or self-condense with diols to form borate esters. The formation of borate esters often increases the complexity of the monomers and leads to more flexible linkers. However, compared to [B3O3] borate esters, the formation of [B4O4] boroxy octahedral rings is more difficult. Therefore, the development of novel boroxy clusters with boroxy octahedral rings as the central skeleton is of great significance for the synthesis and performance research of inorganic-organic hybrid functional materials. Summary of the Invention
[0003] Boron-nitrogen bonds (B←N bonds) have unique chemical properties due to their strong covalent nature, directionality, and reversibility. When a B←N bond is formed, the configuration of the B atom can be trigonal planar (sp 2 ) into a tetrahedral geometry (sp 3 ), so the addition of a N-containing donor can provide the steric hindrance required for the transition from a planar [B3O3] unit to a [B4O4] eight-membered ring. To this end, the present application forms a Cu4B4O4(Pz-CH3)8X4 boron-oxygen crystalline compound by adding 4-methylpyrazole as a N-containing donor and a boron-containing compound under the induction of copper halide. The compound has a stable [B4O4] central skeleton, and the peripheral 4-methylpyrazole ligand can not only form a stable B←N bond as support, but also, as an organic component, can prevent the sensitive [B4O4] borate ester from being partially hydrolyzed. This method is of great significance for the development of new [B4O4] borate inorganic-organic hybrid crystals and the study of their properties.
[0004] To achieve the above-mentioned object, the present invention provides a Cu4(B4O4)(Z)8X4 boron-oxygen crystalline compound, wherein Z is the group remaining after removing the hydrogen bonded to the nitrogen atom on 4-methylpyrazole;
[0005] X is Cl, Br or I;
[0006] When X is Cl, the Cu4(B4O4)(Z)8Cl4 boron-oxygen crystalline compound has substantially the following properties: Figure 4 The X-ray powder diffraction pattern shown;
[0007] When X is Br, the Cu4(B4O4)(Z)8Br4 boron-oxygen crystalline compound has substantially the following properties: Figure 5 The X-ray powder diffraction pattern shown;
[0008] When X is I, the Cu4(B4O4)(Z)8I4 boron-oxygen molecular crystalline compound has substantially the following properties: Figure 6 The X-ray powder diffraction pattern is shown.
[0009] According to an embodiment of the present invention, the Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystalline material has a central configuration of an eight-membered boron-oxygen ring, the periphery of which is coordinated with eight 4-methylpyrazoles that have been deprotonated, and four copper halides are bridged by 4-methylpyrazoles at the upper and lower ends of the eight-membered boron-oxygen ring.
[0010] According to the present invention, the Cu4(B4O4)(Z)8Cl4 boron-oxygen molecular crystalline compound is a pure phase.
[0011] According to the present invention, the Cu4(B4O4)(Z)8Cl4 boron-oxygen molecular crystalline compound is an organic-inorganic hybrid compound.
[0012] According to the present invention, the Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystalline compound has a symmetrical structure.
[0013] According to an embodiment of the present invention, through single crystal X-ray analysis, the Cu4(B4O4)(Z)8Cl4 boron-oxygen molecular crystalline compound has the following crystal parameters:
[0014]
[0015] The present invention also provides a method for preparing the above-mentioned Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystalline compound, which is a reaction of a boron compound with pyrazole induced by cuprous or copper ions, comprising the following steps:
[0016] Boron compound, cuprous halide CuX or copper halide CuX2, and 4-methylpyrazole are heated and reacted in a solvent to prepare Cu4(B4O4)(Z)8X4 molecular crystalline material;
[0017] wherein Z and X have the same meanings as above.
[0018] According to an embodiment of the present invention, the cuprous halide CuX is selected from at least one of cuprous chloride, cuprous bromide and cuprous iodide.
[0019] According to an embodiment of the present invention, the copper halide CuX2 is selected from at least one of copper chloride, copper bromide and copper iodide.
[0020] According to an embodiment of the present invention, the boron compound is selected from at least one of boric acid, trimethyl borate, phenylboronic acid, 3-formyl-phenylboronic acid, pyridine-3-boric acid, and quinoline-8-boric acid, preferably boric acid.
[0021] According to the present invention, the molar ratio of the boron compound to 4-methylpyrazole may be (1:1) to (1:10), preferably (1:1) to (1:4).
[0022] According to the present invention, the molar ratio of the boron compound to cuprous halide CuX or copper halide CuX2 can be (0.5:1) to (3:1), preferably (1:1) to (2:1).
[0023] According to the present invention, the solvent is selected from at least one of acetonitrile, N,N-dimethylformamide, and 1,4-dioxane, preferably acetonitrile.
[0024] According to the present invention, the temperature of the heating reaction may be 60-140°C; preferably 70-120°C, such as 80°C.
[0025] According to the present invention, the reaction time can be 3 to 240 hours, more preferably 6 to 72 hours, such as 24 hours. For example, the reaction can be carried out at 80°C for 24 hours, or at 80°C for 12 hours, or at 100°C for 48 hours.
[0026] According to the present invention, the reaction can be carried out in a glass bottle or a polytetrafluoroethylene pressure vessel;
[0027] Preferably, the reaction further comprises a step of purifying the reaction product, wherein the purification comprises washing and separating the reaction product. Furthermore, the reaction product is preferably washed with an alcohol solvent and dried at room temperature to obtain a Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystalline compound.
[0028] Preferably, the alcohol solvent used for cleaning is ethanol.
[0029] Preferably, the yield of the Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystalline material can reach more than 70%.
[0030] The present invention also provides the use of the above-mentioned Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystal as a nonlinear optical material.
[0031] Beneficial effects
[0032] 1. The Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystalline material of the present invention is obtained by mixing the reaction raw materials and then subjecting them to a solvent thermal synthesis method to a one-step self-assembly reaction. This method has simple synthesis steps, high repeatability, can be synthesized stably in large quantities, has low requirements for the purity of the raw materials, and can achieve a yield of more than 70%. It can also be synthesized in large quantities, which is conducive to large-scale production. In addition, the above raw materials are easy to obtain and inexpensive, which is low in cost and is conducive to large-scale production. In addition, the post-processing of this method is simple and easy. A pure crystalline product can be obtained by simple alcohol washing and separation and drying at room temperature, which is less polluting and meets green environmental protection requirements.
[0033] 2. The Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystalline prepared by the present invention has good stability in air and ethanol, and exhibits a saturated absorption response signal in the third-order nonlinear optical performance test, and can be used as a nonlinear optical material. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Figure 1 Schematic diagram and crystal photograph of the crystal structure of the crystalline product prepared in Example 1 of the present invention;
[0035] Figure 2 Schematic diagram and crystal photograph of the crystal structure of the crystalline product prepared in Example 2 of the present invention;
[0036] Figure 3 Schematic diagram and crystal photograph of the crystal structure of the crystalline product prepared in Example 3 of the present invention;
[0037] Figure 4 The X-ray powder diffraction pattern of the Cu4(B4O4)(Z)8Cl4 boron oxide crystalline material prepared in Example 1; wherein the "simulated pattern" is the X-ray powder diffraction pattern obtained by simulating the crystal structure; the stability in air, ethanol and water is the X-ray powder diffraction pattern of the crystalline material tested on an X-ray powder diffractometer in the corresponding environments;
[0038] Figure 5 The X-ray powder diffraction pattern of the Cu4(B4O4)(Z)8Br4 boron oxide crystalline material prepared in Example 2; wherein the "simulated pattern" is the X-ray powder diffraction pattern obtained by simulating the crystal structure; the stability in air, ethanol and water is the X-ray powder diffraction pattern of the crystalline material tested on an X-ray powder diffractometer in the corresponding environments;
[0039] Figure 6The X-ray powder diffraction pattern of the Cu4(B4O4)(Z)8I4 boron oxide crystalline material prepared in Example 3; wherein the "simulated pattern" is the X-ray powder diffraction pattern obtained by simulating the crystal structure; the stability in air, ethanol, and water is the X-ray powder diffraction pattern of the crystalline material tested on an X-ray powder diffractometer in the corresponding environments;
[0040] Figure 7 This is a picture of the third-order nonlinear optical performance test of the Cu4(B4O4)(Z)8I4 boron-oxygen molecular crystal prepared in Example 3;
[0041] Figure 8 Diagram of the reaction mechanism of boric acid and pyrazole induced by copper ions for the preparation of Cu4(B4O4)(Z)8X4 boron oxide molecular crystals. DETAILED DESCRIPTION
[0042] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of protection of the present invention.
[0043] Unless otherwise stated, the reagents used in the present invention are commercially available.
[0044] The single crystal structure analysis of the present invention was performed using a Rigaku Supernova single crystal diffractometer.
[0045] The X-ray powder diffraction test used Cu-Kα radiation as the radiation source.
[0046] Example 1
[0047] Preparation of Cu4(B4O4)(Z)8Cl4 Boron Oxygen Molecular Crystals
[0048] The specific preparation method is as follows: CuCl (0.5 mmol), boric acid (1 mmol), 4-methylpyrazole (1 mmol), and acetonitrile (3 mL) are placed in a 20 mL glass bottle, mixed uniformly at room temperature, reacted in an 80°C oven for 24 hours, removed, and naturally cooled to room temperature. The solid phase is separated and then rinsed with ethanol and naturally dried in air to obtain the light blue rhombus crystalline target product, boron oxide molecular crystal (Cu4(B4O4)(Z)8Cl4). The yield is about 75% (calculated based on the mass of CuCl).
[0049] Example 2
[0050] Preparation of Cu4(B4O4)(Z)8Br4 Boron Oxygen Molecular Crystals
[0051] The specific preparation method is as follows: CuBr (0.5 mmol), boric acid (1 mmol), 4-methylpyrazole (1 mmol), and acetonitrile (3 mL) are placed in a 20 mL glass bottle, mixed evenly at room temperature, reacted in an 80°C oven for 24 hours, taken out, naturally cooled to room temperature, the solid phase is separated and then rinsed with ethanol, and naturally dried in air to obtain a light blue rhombus crystalline target product boron oxide molecular crystal (Cu4(B4O4)(Z)8Br4). The yield is about 78% (calculated based on the mass of CuBr).
[0052] Example 3
[0053] Preparation of Cu4(B4O4)(Z)8I4 Boron Oxygen Molecular Crystals
[0054] The specific preparation method is as follows: CuI (0.5 mmol), boric acid (1 mmol), 4-methylpyrazole (1 mmol), and acetonitrile (3 mL) are placed in a 20 mL glass bottle, mixed evenly at room temperature, reacted in an 80°C oven for 24 hours, taken out, naturally cooled to room temperature, the solid phase is separated and then rinsed with ethanol, and naturally dried in air to obtain a light blue rhombus crystalline target product boron oxide molecular crystal (Cu4(B4O4)(Z)8I4). The yield is about 81% (calculated based on the mass of CuI).
[0055] 2. Third-order nonlinear optical performance test
[0056] Cu4(B4O4)(Z)8I4 (2 mg) prepared in the above example was ultrasonically dispersed in 1 mL of ethanol solvent to obtain a homogeneous solution as the test sample. The open Z scanning technique was used, and the instrument model was NLO-MZ. The Nd:YAG laser was used as the excitation light source (repetition frequency 10 Hz, period 8.5 ns, wavelength 532 nm). All measurements were performed at room temperature. The third-order nonlinear optical properties of the crystal dispersed in ethanol were measured, see Figure 7 .
[0057] Figure 1-3 The crystal structure diagram and crystal photo of the boron-oxygen molecular crystal prepared in Example 1-3 are shown. Figure 1-3 It can be seen that the Cu4(B4O4)(Z)8X4 boron-oxygen molecule crystal has a stable boron-oxygen eight-membered ring central configuration, the periphery of which is coordinated with eight 4-methylpyrazoles that have been deprotonated, and then four copper halides are bridged by 4-methylpyrazoles at the upper and lower ends of the boron-oxygen eight-membered ring. Figure 1-3 From the crystal photos, we can see that the color of the Cu4(B4O4)(Z)8X4 boron oxide molecule crystal changes with the difference of X. Cu4(B4O4)(Z)8Cl4 is light blue, Cu4(B4O4)(Z)8Br4 is dark blue, and Cu4(B4O4)(Z)8I4 is dark green.
[0058] The Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystals prepared in Examples 1-3 were subjected to X-ray powder diffraction tests. The test results are as follows: Figure 4-6 shown.
[0059] from Figure 4-6 As can be seen from the figure, the X-ray powder diffraction pattern of the Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystal is consistent with the theoretical simulation, proving that the obtained crystal is the target structure.
[0060] The purity of Cu4(B4O4)(Z)8X4 boron oxide molecule crystal is high (95%). The Cu4(B4O4)(Z)8X4 boron oxide molecule crystal was placed in ethanol and water for three days respectively. The XRD results of the crystal after placement are as follows: Figure 4-6 As shown. Figure 4-6 It can be seen that the three crystalline substances are very stable and can exist stably in air, ethanol and water.
[0061] from Figure 7 As can be seen from the figure, the Z-scan curve of the Cu4(B4O4)(Z)8I4 boron oxide crystalline material prepared in Example 3 exhibits an upward peak, demonstrating saturation absorption characteristics. Furthermore, as the transmittance of the sample decreases, the saturation absorption signal gradually increases, making it a potential nonlinear optical material. The same phenomenon is observed for Cu4(B4O4)(Z)8Br4 and Cu4(B4O4)(Z)8I4.
[0062] from Figure 8 The preparation of Cu4(B4O4)(Z)8X4 borane molecular crystals is a copper-ion-induced reaction between boric acid and pyrazole. Both organic and inorganic boric acids can be used as starting materials, with copper ions having an inductive effect. When organic boric acid is used as the starting material, copper ions induce the cleavage of the boron-carbon bond. When inorganic boric acid is used as the starting material, copper ions promote the formation of [B4O4].
[0063] The above describes exemplary embodiments of the present invention. However, the scope of protection of this application is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A Cu4(B4O4)(Z)8X4 boron oxide crystalline compound, wherein Z is the group remaining after removing the hydrogen attached to the nitrogen atom of 4-methylpyrazole; and X is Cl, Br, or I; characterized in that: When X is Cl, the Cu4(B4O4)(Z)8Cl4 boron-oxygen molecular crystalline compound has an X-ray powder diffraction pattern substantially as shown in FIG4 ; When X is Br, the Cu4(B4O4)(Z)8Br4 boron-oxygen molecular crystalline compound has an X-ray powder diffraction pattern substantially as shown in FIG5 ; When X is I, the Cu4(B4O4)(Z)8I4 boron-oxygen molecular crystalline compound has an X-ray powder diffraction pattern substantially as shown in FIG. 6 .
2. The Cu4(B4O4)(Z)8Cl4 boron oxide crystalline material according to claim 1, characterized in that The Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystalline material has a central boron-oxygen eight-membered ring configuration, the periphery of which is coordinated with eight deprotonated 4-methylpyrazoles, and four copper halides are bridged by 4-methylpyrazoles at the upper and lower ends of the boron-oxygen eight-membered ring.
3. The Cu4(B4O4)(Z)8Cl4 boron oxide crystalline material according to claim 1 or 2, characterized in that Through single crystal X-ray analysis, the Cu4(B4O4)(Z)8Cl4 boron-oxygen molecular crystalline compound has the following crystal parameters: 。 4. The method for preparing the Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystalline compound according to any one of claims 1 to 3, which is a reaction of a boron compound with pyrazole induced by cuprous or copper ions, characterized in that: The following steps are involved: Boron compound, cuprous halide CuX or copper halide CuX2, and 4-methylpyrazole are heated and reacted in a solvent to prepare Cu4(B4O4)(Z)8X4 molecular crystalline material; Wherein, Z and X have the definitions as described in claim 1.
5. The method according to claim 4, characterized in that The cuprous halide CuX is selected from at least one of cuprous chloride, cuprous bromide, and cuprous iodide; the copper halide CuX2 is selected from at least one of cupric chloride, cupric bromide, and cupric iodide.
6. The method according to claim 4 or 5, characterized in that The boron compound is selected from at least one of boric acid, trimethyl borate, phenylboric acid, 3-formyl-phenylboric acid, pyridine-3-boric acid, and quinoline-8-boric acid.
7. The method according to any one of claims 4 to 6, characterized in that: The molar ratio of the boron compound to 4-methylpyrazole is (1:1) to (1:10).
8. The method according to any one of claims 4 to 7, characterized in that: The molar ratio of the boron compound to cuprous halide CuX or copper halide CuX2 is (0.5:1) to (3:1).
9. The method according to any one of claims 4 to 8, characterized in that The temperature of the heating reaction is 60-140°C.
10. Use of the Cu4(B4O4)(Z)8X4 boron-oxygen molecular crystal according to any one of claims 1 to 3 as a nonlinear optical material.