A near-infrared light-emitting metal halide that can be excited by blue light, its preparation and application

Abstract

This invention belongs to the field of luminescent materials technology, and discloses a near-infrared light-emitting metal halide that can be excited by blue light, its preparation, and its application. The chemical formula of the metal halide of this invention is [TPPen]₂[SbBr₅]; wherein, [TPPen]₂... + It is a pentyltriphenylphosphine cation. The trivalent antimony ion forms a complex anion with the bromide ion, which is ultimately compensated for by the charge of the organic cation. This invention prepares metal halide crystals or powders via a solution method. This metal halide exhibits a high quantum yield, with its emission peak in the near-infrared band and excitation peak covering the blue light region. Near-infrared optical devices fabricated from this material have potential applications in the near-infrared display field.

Description

Technical Field

[0001] This invention relates to the field of luminescent materials, specifically to a near-infrared light-emitting metal halide that can be excited by blue light, its preparation method, and its application in near-infrared light source display devices. Background Technology

[0002] Near-infrared light sources, due to their lossless nature and high penetration, have been widely studied in applications such as medical diagnosis, night vision, and food analysis. Near-infrared light, with its emission wavelength in the 700-1100nm range, has a significant penetration depth into biological tissues. Considering its near-harmlessness to human tissues and organ functions, it has excellent application potential in medical and biological diagnostics. Traditional near-infrared light sources, such as halogen lamps, are insufficient to meet diverse needs due to their large size, low luminous efficiency, and high operating temperature. Therefore, exploring novel near-infrared luminescent materials is currently a research hotspot.

[0003] Zero-dimensional metal halides hold great promise for applications in the field of light emission due to their rich structural features and efficient luminescence properties. Notably, these materials are simple and low-cost to prepare. By selecting different metals and halide ions, efficient emission of red, orange, yellow, green, and blue light can be achieved. However, research reports on zero-dimensional metal halide materials exhibiting near-infrared light emission are scarce.

[0004] Currently reported zero-dimensional metal halides exhibiting near-infrared luminescence include the entirely inorganic Cs₂ZnCl₄:Sb 3+ and Cs2ZnBr4:Sb 3+ (Sb 3+ -Doping in Cesium Zinc Halides Single Crystals Enabling High-Efficiency Near-Infrared Emission. Advanced Functional Materials 2021, 31, 2105316) and organic-inorganic hybrids (C 13 H 22 N)2Sb2Cl8、(C 10 H 16 N)2Sb2Cl8、(C 16 H 36 P)SbCl4(HighlyDistorted Antimony(III)Chloride[Sb2Cl8] 2-Dimers for Near-Infrared Luminescence up to 1070 nm. Angewandte Chemie-International Edition 2022, 61, e202208881. However, the excitation wavelengths of these materials are in the ultraviolet region. Near-infrared emitting materials excited by ultraviolet light have a large Stokes shift, which consumes a lot of energy, resulting in low luminous efficiency. In addition, ultraviolet light source chips are more expensive than blue light source chips on the market. Therefore, exploring near-infrared light materials that can be excited by blue light for near-infrared light source applications is of great research significance. Summary of the Invention

[0005] To address the shortcomings and deficiencies of the existing technologies, one objective of this invention is to develop a near-infrared emitting metal halide that can be excited by blue light. This material has a simple synthesis method, and the prepared material exhibits a high photoluminescence quantum yield. Its excitation peak covers the blue light region, and its emission peak covers the near-infrared light region, thus solving the key problem of the current lack of blue light-excited zero-dimensional metal halide near-infrared light materials.

[0006] The second objective of this invention is to provide a method for preparing near-infrared light-emitting metal halides that can be excited by blue light. This preparation method is simple, easy to operate, requires low-cost equipment, and is pollution-free.

[0007] A third objective of this invention is to provide the application of the aforementioned near-infrared light-emitting metal halide that can be excited by blue light in near-infrared light source display devices.

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0009] This invention provides a near-infrared light-emitting metal halide that can be excited by blue light, the chemical formula of which is [TPPen]2[SbBr5], wherein [TPPen]... + It is a pentyltriphenylphosphine cation.

[0010] This invention provides a method for preparing near-infrared light-emitting metal halides that can be excited by blue light, comprising the following steps:

[0011] (1) Mix antimony tribromide and pentyltriphenylphosphine bromide [TPPen]Br in a molar ratio of 1:3 or 1:2 and dissolve them in one or more solvents such as acetonitrile and dichloromethane. Stir at room temperature or under heating until completely or partially dissolved. The heating temperature is 50-60°C and the heating and stirring time is 30-60 min.

[0012] (2) Filter the solution from step (1) while it is still hot to obtain a clear solution;

[0013] (3) Let the solution from step (2) stand in the presence of one or more antisolvents such as acetone or diethyl ether or stand directly for 24 to 72 hours to slowly evaporate until crystals or powder precipitate.

[0014] (4) Separate the crystals or powder precipitated in step (3) by filtration, wash them two or three times with one or more organic solvents such as acetone and diethyl ether, and then place them in a vacuum drying oven at a temperature of 40-60°C for 6-24 hours to obtain seed crystals or powder, which are the near-infrared light emitting metal halide materials.

[0015] Further, in step (1), the molar volume ratio of antimony tribromide and pentyltriphenylphosphine bromide [TPPen]Br to the solvent is 1:2 to 1:6 mmol / mL.

[0016] This invention employs a simple solution method, utilizing the different solubilities of materials in different solvents. An antisolvent is used to allow crystals to precipitate through supersaturation. In experiments without an antisolvent, the volatility of the solvent is utilized, allowing the solution to quickly reach saturation and precipitate crystals. This synthesis method does not involve high-temperature solid-phase reactions, thus solving the problems of energy consumption and time-consuming processes. The metal halide used is a low-toxicity antimony-based bromide.

[0017] This invention also provides the application of the aforementioned near-infrared emitting metal halide material in near-infrared light source display devices. The fabrication of this device involves a 440nm emitting blue LED chip and the fabricated near-infrared emitting metal halide material.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] (1) This invention prepares and synthesizes low-dimensional metal halide crystals / powders by a simple solution method, which has a high photoluminescence quantum yield of about 40%. Its emission peak is in the near-infrared band, and the excitation peak covers the blue light region. The optimal excitation peak wavelength is 430 nm and the optimal emission peak wavelength is 730 nm.

[0020] (2) The near-infrared light source device obtained by the present invention can capture the texture of blood vessels in the palm, which has potential application value in biomedicine.

[0021] (3) The metal halide preparation process realized by the present invention is easy to operate, has good repeatability, low equipment cost and no pollution, and can generate huge social and economic benefits, and is suitable for widespread use. Attached Figure Description

[0022] Figure 1 These are the single-crystal structure diagrams of [TPPen]2[SbBr5] prepared in Examples 1-7;

[0023] Figure 2 These are the XRD diffraction patterns of the [TPPen]2[SbBr5] powders prepared in Examples 1-7;

[0024] Figure 3 These are the excitation and emission spectra of [TPPen]2[SbBr5] prepared in Examples 1-7;

[0025] Figure 4 This is a graph showing the luminescence lifetime decay of [TPPen]2[SbBr5] prepared in Examples 1-7;

[0026] Figure 5 This relates to the bioimaging application of the near-infrared optical device [TPPen]2[SbBr5] prepared in Example 8. Detailed Implementation

[0027] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading this invention, any modifications of the invention by those skilled in the art in various equivalent forms will fall within the scope defined by the appended claims.

[0028] Example 1

[0029] Weigh 414 mg and 361 mg of samples of pentyltriphenylphosphine bromide and SbBr3 respectively in a molar ratio of 2:1, pour them into a 3 mL glass bottle, add 1 mL of dichloromethane solution to the container, stir at room temperature for 10 min to obtain a solution with a small amount of precipitate, filter to obtain a clear solution; place the obtained solution in 2 mL of diethyl ether as an antisolvent atmosphere and let it stand for 24 h; after the reaction is completed, separate the precipitated crystals or powder by vacuum filtration and wash with diethyl ether two to three times; finally, place the above crystals or powder in a vacuum drying oven at 40°C and dry for 24 h to obtain the final near-infrared emitting metal halide material [TPPen]2[SbBr5].

[0030] Example 2

[0031] According to the molar ratio of pentyltriphenylphosphine bromide and SbBr3 of 3:1, 621 mg and 361 mg of samples were weighed respectively and poured into 3 mL glass bottles. 1 mL of dichloromethane solution was added to the container and stirred at room temperature for 10 min to obtain a solution with a small amount of precipitate. The solution was filtered to obtain a clear solution. The obtained solution was placed in 2 mL of diethyl ether as an antisolvent atmosphere and allowed to stand for 72 h. After the reaction was completed, the precipitated crystals or powder were separated by vacuum filtration and washed two to three times with diethyl ether. Finally, the above crystals or powder were placed in a vacuum drying oven at 40°C and dried for 24 h to obtain the final near-infrared emitting metal halide material [TPPen]2[SbBr5].

[0032] Example 3

[0033] Weigh 414 mg and 361 mg of samples of pentyltriphenylphosphine bromide and SbBr3 respectively in a molar ratio of 2:1, pour them into a 3 mL glass bottle, add 1 mL of dichloromethane solution to the container, stir at room temperature for 10 min to obtain a solution with a small amount of precipitate, filter to obtain a clear solution; place the obtained solution in 2 mL of acetone as an antisolvent atmosphere and let it stand for 72 h; after the reaction is completed, separate the precipitated crystals or powder by vacuum filtration and wash with acetone two to three times; finally, place the above crystals or powder in a vacuum drying oven at 40 °C for 24 h to obtain the final near-infrared emitting metal halide material [TPPen]2[SbBr5].

[0034] Example 4

[0035] According to the molar ratio of pentyltriphenylphosphine bromide and SbBr3 of 3:1, 621 mg and 361 mg of the sample were weighed respectively and poured into a 10 mL glass bottle. 6 mL of acetonitrile solution was added to the container, and the mixture was heated and stirred at 50 °C for 60 min to obtain a clear solution. The solution was sealed with sealing film, and small holes were punched in it. The solution was allowed to stand for 24 h. After the reaction was completed, the precipitated crystals or powder were separated by vacuum filtration and washed two to three times with ether. Finally, the crystals or powder were placed in a vacuum drying oven at 60 °C and dried for 6 h to obtain the final near-infrared emitting metal halide material [TPPen]2[SbBr5].

[0036] Example 5

[0037] According to the molar ratio of pentyltriphenylphosphine bromide and SbBr3 of 3:1, 621 mg and 361 mg of the sample were weighed respectively and poured into a 10 mL glass bottle. 2 mL of acetonitrile solution was added to the container, and the mixture was heated and stirred at 60 °C for 30 min to obtain a clear solution. The obtained solution was placed in 4 mL of diethyl ether as an antisolvent atmosphere and allowed to stand for 72 h. After the reaction was completed, the precipitated crystals or powder were separated by vacuum filtration and washed two to three times with diethyl ether. Finally, the crystals or powder were placed in a vacuum drying oven at 40 °C and dried for 24 h to obtain the final near-infrared emitting metal halide material [TPPen]2[SbBr5].

[0038] Example 6

[0039] According to the molar ratio of pentyltriphenylphosphine bromide and SbBr3 of 3:1, 621 mg and 361 mg of the sample were weighed respectively and poured into a 3 mL glass bottle. 2 mL of acetonitrile solution was added to the container, and the mixture was heated and stirred at 60 °C for 30 min to obtain a clear solution. The obtained solution was placed in 4 mL of acetone as an antisolvent atmosphere and allowed to stand for 72 h. After the reaction was completed, the precipitated crystals or powder were separated by vacuum filtration and washed two to three times with diethyl ether. Finally, the above crystals or powder were placed in a vacuum drying oven at 40 °C and dried for 24 h to obtain the final near-infrared emitting metal halide material [TPPen]2[SbBr5].

[0040] Example 7

[0041] Weigh 414 mg and 361 mg of samples respectively according to the molar ratio of pentyltriphenylphosphine bromide and SbBr3 of 2:1, pour them into 10 mL glass bottles, add 6 mL of acetonitrile solution to the container, heat and stir at 50 °C for 60 min to obtain a clear solution; seal with sealing film, poke small holes and let stand for 24 h; after the reaction is completed, separate the precipitated crystals or powder by vacuum filtration, and wash with ether two to three times; finally, place the above crystals or powder in a vacuum drying oven at 60 °C for 6 h to obtain the final near-infrared emitting metal halide material [TPPen]2[SbBr5].

[0042] Example 8

[0043] Take 5 mg of the [TPPen]2[SbBr5] crystal or powder prepared in Examples 1-7 and encapsulate it on a 440nm blue LED chip with UV-curable adhesive.

[0044] X-ray single-crystal diffraction, X-ray powder diffraction, excitation and emission spectra, and luminescence lifetime were performed on the [TPPen]2[SbBr5] crystals or powders prepared in Examples 1-7.

[0045] The application of near-infrared imaging in the encapsulation material prepared in Example 8 is demonstrated.

[0046] Figure 1 This is a single-crystal structure diagram of [TPPen]₂[SbBr₅] prepared in Examples 1-7. In this structure, Sb atoms and Br atoms form [SbBr₅]. 2- The halide anion is then reacted with [TPPen]. + The organic cations are in charge balance. Notably, Br is present in the structure with an occupation of 0.83. [TPPen] + Organic cations are represented by the ball-and-stick model in the diagram, where the balls represent C, H, or P atoms and the sticks represent the bonds connecting two atoms.

[0047] Figure 2 These are the XRD diffraction patterns of the [TPPen]2[SbBr5] powders prepared in Examples 1-7. The diffraction peaks of the prepared powder samples are consistent with those of the single-crystal diffraction simulation, and no impurity phases are generated, indicating that a pure phase material has been obtained.

[0048] Figure 3 These are the excitation and emission spectra of [TPPen]₂[SbBr₅] prepared in Examples 1-7. It can be seen that the [TPPen]₂[SbBr₅] crystal has a wide excitation range, with most excitation peaks located in the blue light region, the optimal excitation peak at 430 nm, and the emission peak at 730 nm, covering the red and even near-infrared light regions. Notably, its photoluminescence quantum yield under blue light excitation is as high as 40%. This spectrum indicates that the material exhibits typical STE luminescence.

[0049] Figure 4 This is a graph showing the luminescence lifetime decay of [TPPen]2[SbBr5] prepared in Examples 1-7. Figure 4 The study showed that the material exhibited a luminescence lifetime of 1.21 μs under 450 nm excitation, further illustrating typical STE luminescence.

[0050] Figure 5 The image shows a photograph of a hand illuminated by the near-infrared light source device of [TPPen]2[SbBr5] prepared in Example 8. The photograph was captured by a near-infrared camera. The blood vessels of the hand can be clearly seen in the image, indicating that the near-infrared light source device prepared by this material has potential applications in biomedicine.

[0051] It should be understood that the above detailed description of the technical solutions of the present invention with reference to optimized embodiments is illustrative and not restrictive. It should not be considered that the specific implementation of the present invention is limited to this. For those skilled in the art, any modifications to the technical solutions described in the embodiments or equivalent substitutions of some technical features without departing from the concept of the present invention should be considered as falling within the scope of patent protection defined by the claims submitted by the present invention.

[0052] The above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A near-infrared light-emitting metal halide that can be excited by blue light, characterized in that, The chemical composition formula of the metal halide is [TPPen]2[SbBr5], wherein [TPPen] + is a pentyltriphenylphosphonium cation.

2. A method for preparing a near-infrared light-emitting metal halide that can be excited by blue light as described in claim 1, characterized in that, Includes the following steps: (1) Mix antimony tribromide and pentyltriphenylphosphine bromide [TPPen]Br in a solvent and dissolve them completely or partially at room temperature or under heating and stirring. (2) Filter the solution from step (1) to obtain a clear solution; (3) Let the solution from step (2) stand under the action of an antisolvent or let it stand to evaporate until crystals or powder precipitate. (4) Separate the crystals or powders precipitated in step (3) by filtration, wash them two or three times with organic solvents, and then dry them in a vacuum drying oven to obtain seed crystals or powders, namely the near-infrared light emitting metal halides that can be excited by blue light.

3. The preparation method according to claim 2, characterized in that, In step (1), the molar ratio of antimony tribromide to pentyltriphenylphosphine bromide [TPPen]Br is 1:2 or 1:

3.

4. The preparation method according to claim 2, characterized in that, In step (1), the solvent is one or more of acetonitrile and dichloromethane.

5. The preparation method according to claim 2, characterized in that, In step (1), the molar volume ratio of the raw material to the solvent is 1:2 to 1:6 mmol / mL; the raw material is antimony tribromide and pentyltriphenylphosphine bromide [TPPen]Br.

6. The preparation method according to claim 2, characterized in that, In step (1), the heating and stirring temperature is 50-60°C and the heating and stirring time is 30-60 min.

7. The preparation method according to claim 2, characterized in that, In step (3), the antisolvent is one or more of acetone and diethyl ether; the standing time is 24 to 72 hours.

8. The preparation method according to claim 2, characterized in that, In step (4), the organic solvent is one or more of acetone and diethyl ether.

9. The preparation method according to claim 2, characterized in that, In step (4), the temperature of the vacuum drying oven is 40-60°C, and the vacuum drying time is 6-24 hours.

10. The application of the near-infrared light-emitting metal halide that can be excited by blue light as described in claim 1 in a near-infrared light source display device.

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