Indium-based hybrid metal halide crystal and preparation method and application thereof

Abstract

The invention discloses an indium-based hybrid metal halide crystal and a preparation method and application thereof, and is characterized in that the chemical formula of the indium-based hybrid metal halide crystal is [(CH3) 4N] 2 [InCl5 (DMF)]; wherein the DMF is N, N '-dimethylformamide; the indium-based hybrid metal halide crystal has a zero-dimensional structure; a metal ion In < 3 + > of halide anions in the zero-dimensional structure is coordinated with five Cl <-> and one N from an organic solvent DMF to form an octahedral configuration; the indium-based hybrid metal halide crystal belongs to a monoclinic system, and the space group is C2 / c. The fluorescent material has the properties of a fluorescent material and an afterglow material, and has the properties of converting ultraviolet light into visible light, emitting green afterglow in 3 seconds and preventing counterfeiting.

Description

Technical Field

[0001] This invention relates to the field of phosphorescent materials technology, specifically to an indium-based hybrid metal halide crystal, its preparation method, and its application in the field of light emission. Background Technology

[0002] Organic-inorganic metal halides, with their advantages of simple preparation processes, tunable optical properties, and high quantum yield, have shown broad application prospects in fields such as light-emitting diodes, fluorescence sensing, bioimaging, and anti-counterfeiting encryption, becoming one of the current research hotspots in the field of optoelectronic materials. Among them, indium-based metal halides, as an important branch of lead-free metal halides, avoid the biotoxicity and environmental risks of lead-based halides due to their low toxicity, good chemical stability, and excellent optoelectronic physical properties, further broadening the application scenarios of metal halide materials, especially in fields with high requirements for biocompatibility and environmental safety, where they have irreplaceable advantages.

[0003] Existing indium-based metal halide materials mostly emit light in a single, fixed wavelength, which is insufficient to meet the requirements for multicolor emission and dynamic color switching. Furthermore, existing long-persistence indium-based halides generally have short afterglow times (e.g., <1 second), weak intensity, and fixed colors. They also often suffer from problems such as difficulty in balancing fluorescence quantum yield and afterglow performance, insufficient luminescence stability, and complex fabrication processes. In particular, there is a lack of materials that simultaneously possess excitation wavelength-dependent multicolor fluorescence emission and excitation wavelength-tunable multicolor long-persistence emission, especially those capable of maintaining a long afterglow exceeding 3 seconds.

[0004] Therefore, developing an indium-based metal halide material with stable chemical composition, low toxicity, excellent fluorescence emission and long afterglow performance, and tunable emission and afterglow colors that are dependent on excitation wavelength is an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] In view of the problems existing in the above and / or existing indium-based hybrid metal halide crystals, their preparation methods and applications, the present invention is proposed.

[0007] Therefore, the purpose of this invention is to provide an indium-based hybrid metal halide crystal, its preparation method and application, which has the properties of both fluorescent and afterglow materials, and features the ability to convert ultraviolet light into visible light, emit green afterglow for 3 seconds and has anti-counterfeiting properties.

[0008] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution: An indium-based hybrid metal halide crystal, characterized in that the chemical formula of the indium-based hybrid metal halide crystal is [(CH3)4N]2[InCl5(DMF)]; DMF is N,N'-dimethylformamide; The indium-based hybrid metal halide crystal has a zero-dimensional structure; The metal ions In of the halide anions in the zero-dimensional structure 3+ With five Cl - And an N-coordination from the organic solvent DMF forms an octahedral configuration.

[0009] As a preferred embodiment of the indium-based hybrid metal halide crystal described in this invention, the indium-based hybrid metal halide crystal belongs to the monoclinic crystal system and has a space group of [missing information]. C 2 / c .

[0010] As a preferred embodiment of the indium-based hybrid metal halide crystal described in this invention, the cell parameters of the indium-based hybrid metal halide crystal are as follows: a = 13.7839(8) Å, b = 11.5452(7) Å, c = 13.8314(8)Å, β = 94.148(2) °, V = 2195.3(2) Å 3 , Z = 4.

[0011] As a preferred embodiment of the indium-based hybrid metal halide crystal described in this invention, the indium-based hybrid metal halide crystal can convert visible light into ultraviolet light; the indium-based hybrid metal halide crystal can still maintain a green afterglow emission for 3 seconds when the ultraviolet light is turned off.

[0012] As a preferred embodiment of the indium-based hybrid metal halide crystal described in this invention, the indium-based hybrid metal halide crystal exhibits blue light emission under 355 nm light excitation, with the emission peak value ranging from 400 to 415 nm.

[0013] A method for preparing indium-based hybrid metal halide crystals, characterized by comprising the following steps: The indium-based hybrid metal halide crystals can be obtained by heating a mixture of tetramethylammonium chloride, InCl3·4H2O and DMF and holding it at that temperature for a certain period of time, then cooling it to room temperature and reacting it with a solvothermal agent.

[0014] In a preferred embodiment of the method for preparing an indium-based hybrid metal halide crystal according to the present invention, the temperature of the solvothermal reaction is 120-170℃ and the reaction time is 2-6 days; the temperature of the solvothermal reaction is 160℃ and the reaction time is 3 days.

[0015] A phosphorescent material, characterized in that it contains at least one of the indium-based hybrid metal halide crystals as described in any one of claims 1-5 or the indium-based hybrid metal halide crystals prepared by the preparation method described in any one of claims 6-7.

[0016] An anti-counterfeiting material, characterized in that it contains at least one of the indium-based hybrid metal halide crystals as described in any one of claims 1-5 or the indium-based hybrid metal halide crystals prepared by the preparation method described in any one of claims 6-7.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: The compound provided in this application is a novel type of indium-based hybrid metal halide, possessing both fluorescent and afterglow material properties. It has the ability to convert ultraviolet light into visible light, emits a 3-second green afterglow, and has anti-counterfeiting properties. This solves the problem that existing indium-based metal halide materials mostly emit light with a single fixed wavelength, making it difficult to meet the needs of multi-color emission and dynamic color switching. At the same time, existing long-afterglow indium-based halides generally have short afterglow times (e.g., <1 second), weak intensity, and fixed colors. They also often suffer from problems such as difficulty in balancing fluorescence quantum yield and afterglow performance, insufficient luminescence stability, and complex preparation processes. In particular, they lack the ability to simultaneously possess excitation wavelength-dependent multi-color fluorescence emission and excitation wavelength-tunable multi-color long-afterglow emission, especially the ability to maintain a long afterglow of more than 3 seconds. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0019] Figure 1 This is a schematic diagram of the crystal structure of an indium-based hybrid metal halide crystal according to the present invention; Figure 2 The excitation and emission spectra of an indium-based hybrid metal halide crystal according to the present invention are shown. Figure 3 This is the afterglow emission spectrum of an indium-based hybrid metal halide crystal according to the present invention; Figure 4 The phosphorescence emission spectrum of an indium-based hybrid metal halide crystal according to the present invention; Figure 5 This is a CIE coordinate diagram of an indium-based hybrid metal halide crystal according to the present invention; Figure 6 This is a schematic diagram of the lifetime test of an indium-based hybrid metal halide crystal according to the present invention; Figure 7 This is a photograph of the afterglow color of an indium-based hybrid metal halide crystal according to the present invention. Figure 8 This is a photograph of an indium-based hybrid metal halide crystal phosphorescent material according to the present invention. Figure 9 This is a photograph of an anti-counterfeiting material for an indium-based hybrid metal halide crystal according to the present invention. Detailed Implementation

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0021] Example Please see Figure 1 The present invention provides an indium-based hybrid metal halide crystal, the chemical formula of which is [(CH3)4N]2[InCl5(DMF)]; DMF is N,N'-dimethylformamide; Indium-based hybrid metal halide crystals have a zero-dimensional structure; Metal ions In halide anions in zero-dimensional structures 3+ With five Cl - And an N-coordination from the organic solvent DMF forms an octahedral configuration.

[0022] Indium-based hybrid metal halide crystals can be obtained by heating a mixture of tetramethylammonium chloride, InCl3·4H2O and DMF and holding it at that temperature for a certain period of time, then cooling it to room temperature and reacting it with a solvothermal agent.

[0023] The temperature for a solvothermal reaction is 120-170℃, and the reaction time is 2-6 days; the temperature for a solvothermal reaction is 160℃, and the reaction time is 3 days.

[0024] Specifically, 1 mmol of InCl3·4H2O powder, 1 mmol of tetramethylammonium chloride, and 3 mL of acetonitrile are mixed, added to a polytetrafluoroethylene liner, sealed in a corresponding stainless steel reactor, and placed in an oven and heated to 160 degrees Celsius. After 4 days, the mixture is removed, cooled, and washed three times with CH3CN at room temperature. After drying, a pure crystal sample can be obtained.

[0025] Furthermore, the molar ratio of tetramethylammonium chloride to InCl3·4H2O is 2:1; both tetramethylammonium chloride and InCl3·4H2O are solids.

[0026] Optionally, tetramethylammonium chloride and InCl3·4H2O are in the form of powder.

[0027] Characterization example Please see Figure 1 Indium-based hybrid metal halide crystals belong to the monoclinic crystal system, space group 1. C 2 / c .

[0028] The unit cell parameters of indium-based hybrid metal halide crystals are a = 13.7839(8) Å, b = 11.5452(7) Å, c =13.8314(8) Å, β = 94.148(2) °, V = 2195.3(2) Å 3 , Z = 4.

[0029] Specifically, the sample was characterized using X-ray single-crystal diffraction, and its structure was analyzed using Shelx 2018. The results showed that the sample is [(CH3)4N]2[InCl5(DMF)], which will be explained in detail below.

[0030] The crystal structure of the sample was obtained by X-ray single-crystal diffraction, such as... Figure 1 As shown. Crystals belong to C twenty one / c The space group has the following cell parameters: a = 13.7839(8) Å, b = 11.5452(7) Å, c = 13.8314(8) Å, β = 94.148(2) °, V =2195.3(2) Å 3 , Z = 4. Figure 1 The large, pure black sphere represents an In atom, the dark gray sphere connected to it represents a Cl atom, the gray-black spheres on the six-membered and five-membered rings represent N atoms, the gray-white spheres represent C atoms, and the white spheres represent H atoms.

[0031] Application Example 1 Please see Figure 2Indium-based hybrid metal halide crystals exhibit blue light emission under 355 nm light excitation, with the emission peak value ranging from 400 to 415 nm.

[0032] The sample emits blue light at 412 nm when excited by 355 nm ultraviolet light, and its solid-state quantum yield is measured to be 16.3% and its fluorescence lifetime is 3.35 ns; it emits blue light at 440 nm when excited by 287 nm ultraviolet light.

[0033] Application Example 2 Please see Figure 3 Indium-based hybrid metal halide crystals can convert visible light into ultraviolet light; indium-based hybrid metal halide crystals can still maintain a green afterglow emission for 3 seconds when ultraviolet light is turned off. The delayed phosphorescence emission spectrum of the sample is as follows Figure 3 As shown, when the sample is irradiated with ultraviolet light at a wavelength of 331 nm, the delayed phosphorescence spectrum (Delay: 0.1s) of the sample shows a broad emission peak at 490 nm, while the blue light emission at a wavelength of 400 nm completely disappears. Therefore, after the ultraviolet lamp is turned off, the blue light emission of the sample immediately disappears, but a green afterglow appears.

[0034] Application Example 3 The sample's emission in delayed mode exhibits a phosphorescent emission spectrum that varies with the excitation wavelength; please refer to [link to relevant documentation]. Figure 4 and Figure 7 The delayed phosphorescence spectra of the sample under excitation at 290 nm, 325 nm, and 365 nm showed maximum emission wavelengths of 460 nm, 490 nm, and 519 nm, respectively. Please refer to... Figure 5 The CIE coordinates show that the emitted colors are blue, blue-green, and green, respectively. Please refer to [link / reference]. Figure 6 The lifetime test results were 234.57 ms, 149.24 ms, and 159.82 ms, respectively.

[0035] Application Example 4 Please see Figure 7 The sample's emission color varied with the excitation wavelength, and the afterglow color also changed after the excitation source was turned off. Based on this, we applied this sample to simple ranges (such as...). Figure 8 (as shown) and complex anti-counterfeiting measures (such as) Figure 9 (As shown). In complex anti-counterfeiting applications, position a is filled with the sample, and position b is filled with commercially available blue phosphor. Because the sample has afterglow properties, while commercially available blue phosphor does not, the sample can be used as an advanced anti-counterfeiting measure.

[0036] Test case X-ray single-crystal diffraction was performed on a Rigaku Oxford Diffraction Synergy Custom (MetalJet) single-crystal diffractometer using a Ga target and K... α Radiation source ( λ = 1.3414 nm), tested at 100 K. The structure was analyzed using Shelx 2018.

[0037] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An indium-based hybrid metal halide crystal, characterized in that, The chemical formula of the indium-based hybrid metal halide crystal is [(CH3)4N]2[InCl5(DMF)]; wherein DMF is N,N'-dimethylformamide; The indium-based hybrid metal halide crystal has a zero-dimensional structure. The metal ion In of the halide anion in the zero-dimensional structure 3+ with five Cl - and one N coordination from the organic solvent DMF forms an octahedral configuration.

2. An indium-based hybrid metal halide crystal according to claim 1, wherein, The indium-based hybrid metal halide crystal belongs to a monoclinic system, and a space group is C 2 / c .

3. An indium-based hybrid metal halide crystal according to claim 2, wherein, The unit cell parameters of the indium-based hybrid metal halide crystal are a = 13.7839(8) Å, b = 11.5452(7) Å, c = 13.8314(8) Å, β = 94.148(2) °, V = 2195.3(2) Å 3 , Z = 4.

4. An indium-based hybrid metal halide crystal according to claim 3, wherein, The indium-based hybrid metal halide crystal can convert visible light into ultraviolet light; the indium-based hybrid metal halide crystal can still maintain green afterglow for 3 seconds when the ultraviolet light is turned off.

5. An indium-based hybrid metal halide crystal according to claim 4, wherein, The indium-based hybrid metal halide crystal exhibits blue light emission under 355 nm light excitation and the emission peak peak value ranges from 400-415 nm.

6. A method of producing an indium-based hybrid metal halide crystal, characterized by, The method comprises the following steps: The mixture of tetramethylammonium chloride, InCl3·4H2O and DMF is heated and kept for a certain time, and then cooled to room temperature, and the indium-based hybrid metal halide crystal can be obtained by using a solvothermal reaction.

7. The preparation method according to claim 6, characterized in that, The temperature of the solvothermal reaction is 120-170℃, and the reaction time is 2-6 days; the temperature of the solvothermal reaction is 160℃, and the reaction time is 3 days.

8. A phosphorescent material, characterized by, At least one of the indium-based hybrid metal halide crystals according to any one of claims 1-5 or the indium-based hybrid metal halide crystals prepared by the preparation method according to any one of claims 6-7.

9. A security material, characterized in that At least one of the indium-based hybrid metal halide crystals according to any one of claims 1-5 or the indium-based hybrid metal halide crystals prepared by the preparation method according to any one of claims 6-7.

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