An organic-inorganic hybrid crystal having photoluminescence properties and a preparation method and applications thereof

Abstract

The application discloses an organic-inorganic hybrid crystal with photoluminescence characteristics and a preparation method and application thereof. 18 H 40 N2MnBr4, which can emit green light under the irradiation of an ultraviolet lamp; the crystal has a central-symmetrical crystallographic structure and crystallizes in a monoclinic P21 / c space group; the preparation method of the material is a solvent evaporation crystallization method; 1-ethyl-3.5-dimethylpiperidine is first synthesized, then the 1-ethyl-3.5-dimethylpiperidine is dissolved in diluted hydrobromic acid, a mixed solution is formed by adding manganese bromide with a certain stoichiometric ratio, the mixed solution is filtered, and the solvent is naturally volatilized at room temperature to obtain yellow-green crystals. The preparation process is simple and easy to operate, the product has high purity, large yield and significant green phosphorescence emission, and is expected to be applied in the fields of display, illumination, medical imaging and the like.

Description

Technical Field

[0001] This invention relates to an organic-inorganic hybrid crystal, its preparation method, and its application, specifically to an organic-inorganic hybrid crystal with photoluminescence properties, its preparation method, and its application. Background Technology

[0002] Organic-inorganic hybrid photoluminescent crystals have been extensively studied and show great promise for applications in displays, lighting, medical imaging, and optical sensing due to their diverse structures, rich optical properties, ease of synthesis, and low cost. Manganese is frequently introduced as a luminescent center into various materials because manganese-based compounds typically exhibit excellent luminescent properties, and manganese is widely distributed in nature and has low toxicity to living systems. Furthermore, based on the quantum confinement effect, zero-dimensional manganese-based photoluminescent crystals exhibit higher photoluminescence quantum yields compared to materials with other structural dimensions. This is because the four-coordinate manganese ion configuration lacks a center of symmetry, and the electronic transitions are only spin-forbidden dd(...). 4 T1(G)→ 6 A1(S)) radiative transition. Therefore, it possesses [MnX4]. 2- Manganese-based compounds with a tetrahedral (X = Cl, Br, I) geometry typically emit green light. However, manganese-based organic-inorganic hybrid luminescent crystals are generally hygroscopic and readily hydrolyze and melt at room temperature, which severely hinders the commercial application of these materials. Therefore, there is an urgent need to design and synthesize manganese-based photoluminescent crystals with excellent photoluminescence properties and high stability. Summary of the Invention

[0003] Objective of the invention: The present invention aims to provide an organic-inorganic hybrid crystal with photoluminescence properties, which has high photoluminescence quantum yield and strong stability; another objective of the present invention is to provide a method for preparing an organic-inorganic hybrid crystal with photoluminescence properties, which is simple, easy to operate and time-saving.

[0004] Technical solution: The present invention relates to an organic-inorganic hybrid crystal with photoluminescence properties, the molecular formula of which is C0. 18 H 40 N2MnBr4 has a zero-dimensional structure and emits bright green phosphorescence under ultraviolet light.

[0005] The chemical structural formula is shown below:

[0006]

[0007] Furthermore, the organic cations and inorganic anions in the crystal self-assemble into a zero-dimensional structure through weak intermolecular interactions. This crystal belongs to the monoclinic crystal system, with space group P21 / c and cell parameters of [missing information]. β=114.21(4)°、Z=4、

[0008] The present invention also provides a method for preparing the above-mentioned organic-inorganic hybrid crystal with photoluminescence properties, comprising the following steps:

[0009] (1) Preparation of 1-ethyl-3,5-dimethylpiperidine;

[0010] (2) Dissolve the 1-ethyl-3,5-dimethylpiperidine obtained in step (1) above in a solvent;

[0011] (3) Add hydrobromic acid solution dropwise to the solution in step (2) and stir to obtain a mixed solution;

[0012] (4) Add manganese bromide to the mixed solution in step (3) and stir to obtain a colorless and transparent solution;

[0013] (5) After filtering the colorless and transparent solution obtained in step (4), a clear solution is obtained. The solvent is allowed to evaporate naturally at room temperature to obtain light yellow-green crystals.

[0014] Furthermore, 1-ethyl-3,5-dimethylpiperidine was prepared by the following method: 3,5-dimethylpiperidine was dissolved in a solvent, then bromoethane was added and the temperature was raised to carry out the reaction. After the reaction was completed, the precipitate was collected, which is 1-ethyl-3,5-dimethylpiperidine.

[0015] Furthermore, in step (1), the molar ratio of bromoethane to 3,5-dimethylpiperidine is 3 to 4:5; the solvent is acetonitrile; the reaction temperature is 60°C; and the reaction time is 12 hours.

[0016] Furthermore, in step (2), 1-ethyl-3,5-dimethylpiperidine is dissolved in a mixed solution of methanol and acetonitrile.

[0017] Further, in step (3), the molar ratio of the white solid 1-ethyl-3,5-dimethylpiperidine to hydrobromic acid is 10:15-16.

[0018] Furthermore, in step (4), the molar ratio of the white solid 1-ethyl-3,5-dimethylpiperidine to manganese bromide is 5:2 to 4.

[0019] Further, in step (4), the concentration of the colorless and transparent solution is 0.2-0.5 mmol / mL. -1 Dissolve 2-5 mmol of 1-ethyl-3,5-dimethylpiperidine in every 10 mL of acetonitrile.

[0020] Furthermore, in step (5), the volatilization temperature of the container placed at room temperature for natural volatilization is 20-40℃.

[0021] On the other hand, the present invention provides an application of the above-mentioned organic-inorganic hybrid crystal with photoluminescence properties in display, lighting or bioimaging.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The organic-inorganic hybrid crystal has a zero-dimensional structure and can emit bright green phosphorescence under ultraviolet light irradiation. It has a high quantum yield and good thermal stability and moisture resistance. (2) The material has the characteristics of simple structure, simple synthesis path, cheap and readily available raw materials, environmental friendliness, and high stability, and is suitable for large-scale industrial production. Attached Figure Description

[0023] Figure 1 Compound C of this invention 18 H 40 Synthetic route diagram of N2MnBr4;

[0024] Figure 2 Compound C in Example 1 18 H 40 Crystal structure diagram of N2MnBr4 at 20℃;

[0025] Figure 3 Compound C in Example 1 18 H 40 The actual sample of N2MnBr4 and the simulated powder diffraction X-ray pattern based on crystallographic data.

[0026] Figure 4 Compound C in Example 1 18 H 40 DSC curve of N2MnBr4.

[0027] Figure 5 Compound C in Example 1 18 H 40 Excitation and emission spectra of N2MnBr4;

[0028] Figure 6 Compound C in Example 1 18 H 40 Fluorescence decay curve of N2MnBr4. Detailed Implementation

[0029] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0030] Figure 1 Compound C of this invention 18 H 40Synthetic route diagram of N2MnBr4. Examples 1-2 show the preparation of this compound according to this synthetic route.

[0031] Example 1

[0032] This embodiment provides a method for preparing an organic-inorganic hybrid crystal with photoluminescence properties, comprising the following steps:

[0033] (1) At room temperature, 10 mol of 3,5-dimethylpiperidine was dissolved in 50 mL of acetonitrile and stirred until it was fully dissolved to obtain a colorless and transparent solution. 8 mol of bromoethane was added dropwise and the temperature was raised to 60 °C to carry out a chemical reaction. After repeated rotary evaporation and washing, a white solid 1-ethyl-3,5-dimethylpiperidine was obtained.

[0034] (2) Dissolve 5 mmol of 1-ethyl-3,5-dimethylpiperidine in a 30 ml mixture of methanol and acetonitrile and stir until homogeneous to obtain a mixed solution;

[0035] (3) Add 2 mmol of manganese bromide and 8 mmol of hydrobromic acid solution to the above mixed solution, stir for 30 min, filter the mixed solution to obtain a colorless and transparent solution, and allow the solvent to evaporate naturally at room temperature to obtain light yellow-green crystals C. 18 H 40 N2MnBr4.

[0036] Example 2

[0037] This embodiment provides a method for preparing an organic-inorganic hybrid crystal with photoluminescence properties, comprising the following steps:

[0038] (1) At room temperature, 5 mol of 3,5-dimethylpiperidine was dissolved in 30 mL of acetonitrile and stirred until it was fully dissolved to obtain a colorless and transparent solution. 3 mol of bromoethane was added dropwise and the temperature was raised to 60 °C to carry out a chemical reaction. After repeated rotary evaporation and washing, a white solid 1-ethyl-3,5-dimethylpiperidine was obtained.

[0039] (2) Dissolve 10 mmol of 1-ethyl-3,5-dimethylpiperidine in a 50 ml mixture of methanol and acetonitrile and stir until homogeneous to obtain a mixed solution;

[0040] (3) Add 8 mmol of manganese bromide and 15 mmol of hydrobromic acid solution to the above mixed solution in sequence. After stirring for 30 min, filter the mixed solution to obtain a colorless and transparent solution. Allow the solvent to evaporate naturally at room temperature to obtain light yellow-green crystals C. 18 H 40 N2MnBr4.

[0041] The light yellow-green crystals prepared in Example 1 were subjected to single-crystal structure analysis using a single-crystal diffractometer manufactured by Bruker GmbH, Germany. Crystal data of the compound were obtained by cutting, selecting, and measuring single crystals. The data collection temperature was 20°C, and the diffraction source was graphite-monochromatic Mo-Kα rays with a scanning mode of ω. Data were processed using the Multi-Scan method for absorption correction. Cell parameters were determined using the least squares method, and data structure analysis was performed using Olex2 software. All non-hydrogen atoms underwent anisotropic refinement using the full-matrix least squares method.

[0042] Table 1. Main crystallographic data of the compounds

[0043]

[0044] K[a] R1=Σ||F o |-|F c || / |F o | [b] wR2=[Σw(F o 2 -F c 2 ) 2 ] / Σw(F o 2 ) 2 ] 1 / 2 .

[0045] The molecular formula of this compound is C. 18 H 40 N2MnBr4, crystal space group P21 / c, specific unit cell parameters are as follows: β=114.21(4)°、Z=4、

[0046] Figure 1 Regarding C in Example 1 18 H 40 Flowchart of N2MnBr4 crystal preparation.

[0047] Figure 2 Crystal structure diagram of the compound in Example 1. The asymmetric unit cell diagram includes two protonated 3,5-dimethylpiperidine cations and one [MnBr4] cation. 2- Inorganic anion unit.

[0048] Figure 3This image compares the powder X-ray diffraction (PXRD) pattern of the sample from Example 1, simulated based on the crystal structure obtained from single-crystal X-ray diffraction, with the PXRD pattern obtained after the sample was ground into powder. Powder X-ray diffraction (PXRD) tests were performed on a Bruker-D8 X-ray powder diffractometer from Bruker GmbH, Germany. The test conditions were: fixed target monochromatic light source Cu-Kα, wavelength, voltage, and current of 40 kV / 20 A, slit widths (DivSlit / RecSlit / SctSlit) of 2.00 deg / 0.3 mm / 2.00 deg, scanning range of 10–70°, and scanning step size of 0.02°. The image clearly shows that the PXRD pattern obtained after grinding the sample is consistent with the simulated crystal structure obtained from single-crystal diffraction, indicating that the prepared C… 18 H 40 The N2MnBr4 crystal is a pure phase, containing no impurities, which also indicates that the crystal structure obtained by the single-crystal diffractometer is correct.

[0049] Figure 4 To test the DSC curve of the crystals in Example 1 after they were ground into powder, a NETZSCH-214 differential scanning calorimeter was used. The DSC curve of the compound showed that it had no obvious thermal change in the range of 30-115℃, indicating that it had good thermal stability.

[0050] Figure 5 To test the excitation and emission spectra of the crystal in Example 1, a Fluorescence Spectrofluorometer FS1000 was used. It can be clearly seen from the figure that the compound has three excitation peaks located at 277, 362 and 454 nm, respectively, but the emission spectrum only shows one emission peak located at 522 nm. These results are consistent with the green light emission of the sample.

[0051] Figure 6 The photoluminescence decay lifetime of the crystal in Example 1 was tested. As shown in the figure, C 18 H 40 The photoluminescence lifetime of N2MnBr4 crystal is 0.402ms, therefore the sample emits green phosphorescence.

Claims

1. An organic-inorganic hybrid crystal with photoluminescence properties, characterized in that: The crystal is (1-ethyl-3,5-dimethylpiperidine)MnBr4, with the molecular formula C. 18 H 40 N2MnBr4, possessing a zero-dimensional structure, emits bright green phosphorescence under ultraviolet light. Its chemical structural formula is shown below:

2. The organic-inorganic hybrid crystal with photoluminescence properties according to claim 1, characterized in that: The organic cations and inorganic anions in the crystal self-assemble into a zero-dimensional structure through weak intermolecular interactions. This crystal belongs to the monoclinic crystal system, crystallizes in the centrosymmetric space group P21 / c, and belongs to the triclinic crystal system, with cell parameters of [missing information]. ° β=114.21(4), Z=4, 3. A method for preparing an organic-inorganic hybrid crystal with photoluminescence properties according to any one of claims 1-2, characterized in that, Includes the following steps: (1) Preparation of 1-ethyl-3,5-dimethylpiperidine; (2) Dissolve the 1-ethyl-3,5-dimethylpiperidine obtained in step (1) above in a solvent; (3) Add hydrobromic acid solution dropwise to the solution in step (2) and stir to obtain a mixed solution; (4) Add manganese bromide to the mixed solution in step (3) and stir to obtain a colorless and transparent solution; (5) After filtering the colorless and transparent solution obtained in step (4), a clear solution is obtained. The solvent is allowed to evaporate naturally at room temperature to obtain light yellow-green crystals.

4. The method for preparing the organic-inorganic hybrid crystal according to claim 3, characterized in that: In step (1), 1-ethyl-3,5-dimethylpiperidine is prepared by the following method: 3,5-dimethylpiperidine is dissolved in a solvent, then bromoethane is added and the temperature is raised to carry out the reaction. After the reaction is completed, the precipitate is collected, which is 1-ethyl-3,5-dimethylpiperidine.

5. The method for preparing the organic-inorganic hybrid crystal according to claim 4, characterized in that: In step (1), the molar ratio of bromoethane and 3,5-dimethylpiperidine is 3 to 4:

5.

6. The method for preparing the organic-inorganic hybrid crystal according to claim 4, characterized in that: In step (2), 1-ethyl-3,5-dimethylpiperidine is dissolved in a mixed solution of methanol and acetonitrile.

7. The method for preparing the organic-inorganic hybrid crystal according to claim 4, characterized in that: In step (3), the molar ratio of 1-ethyl-3,5-dimethylpiperidine to hydrobromic acid is 10:15-16.

8. The method for preparing the organic-inorganic hybrid crystal according to claim 4, characterized in that: In step (4), the molar ratio of 1-ethyl-3,5-dimethylpiperidine to manganese bromide is 5:2 to 4.

9. The method for preparing the organic-inorganic hybrid crystal according to claim 4, characterized in that: In step (5), the volatilization temperature of the product placed at room temperature for natural volatilization is 20-40℃.

10. The application of an organic-inorganic hybrid crystal with photoluminescence properties as described in any one of claims 1-2 in display, illumination or bioimaging.

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