Organic near-infrared room-temperature phosphorescent material, preparation method thereof and near-infrared light-emitting diode
By combining thiocarbonyl and auxiliary electron-absorbing groups, an organic near-infrared room temperature phosphorescence dye with a dispersed matrix was developed, which solved the processability and toxicity of traditional materials and achieved low molecular weight near- Infrared phosphorescence effect and suitable for ultraviolet light emitting diodes.
Patent Information
- Application Number
- CN202411140517.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-19
- Publication Date
- 2024-12-13
AI Technical Summary
Traditional inorganic and organometallic system phosphorescent materials rely on expensive and toxic heavy metals, and the problem of large-plane luminescent solubility limits its processability, and the carcinogenicity of fused-ring aromatic hydrocarbons is not easy to degrade, making it difficult to achieve low molecular weight near-infrared room temperature phosphorescence.
Using thiocarbonyl and auxiliary electron-absorbing groups to combine with the dispersed matrix, an organic near-infrared room temperature phosphorescent material without heavy metals and fused ring aromatic hydrocarbons was developed, and the It is coated on the ultraviolet light emitting diode.
It realizes near-infrared room temperature phosphorescence at ultra-low molecular weight, has good processability and cost-effectiveness, and avoids the use of heavy metals, and is suitable for the application of irregular surfaces.
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Figure CN119120006A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of organic light-emitting materials, and in particular to an organic near-infrared room temperature phosphorescent material and a preparation method thereof, and a near-infrared light-emitting diode. Background Art
[0002] Luminescent materials with various unique properties have attracted interest from scientific research to industry. Room temperature phosphorescence (RTP) materials have attracted widespread attention due to their large Stokes shift and longer lifetime compared to fluorescence. These advantages have promoted their application in molecular switches, organic light-emitting diodes (OLEDs), anti-counterfeiting and bio-imaging.
[0003] Traditional phosphorescent materials focus on inorganic and organic metal systems, which usually rely on heavy metals such as platinum and iridium to promote the intersystem crossing (ISC) process. In order to avoid the use of these expensive and toxic heavy metals, pure organic room temperature phosphorescence has developed in recent years. Among them, the introduction of heavy atoms such as bromine and iodine and heteroatom-containing groups such as carbonyl groups are used to enhance ISC, while strategies such as crystallization, copolymerization, and host-guest interaction are used to suppress the non-radiative transition of the luminophore. However, whether for fluorescence or phosphorescence, long-wavelength emission is usually achieved by extending conjugation, and the solubility problem of luminophores with large planes limits their processability, and polycyclic aromatic hydrocarbons are carcinogenic and not easily degraded. Summary of the invention
[0004] The present application provides an organic near-infrared room temperature phosphorescent material and a preparation method thereof, and a near-infrared light-emitting diode, which can achieve near-infrared room temperature phosphorescence while maintaining an ultra-low molecular weight.
[0005] In a first aspect, an embodiment of the present application provides an organic near-infrared room temperature phosphorescent material, comprising a near-infrared phosphorescent dye and a dispersed matrix, wherein the near-infrared phosphorescent dye comprises a thiocarbonyl group and an auxiliary electron-withdrawing group, and the chemical structure of the near-infrared phosphorescent dye is shown in formula (I):
[0006]
[0007] Among them, EWG is an auxiliary electron-withdrawing group.
[0008] In some embodiments, the electron withdrawing group includes at least one of a cyano group, an ethoxyl group, an alkynyl group, a trifluoromethyl group, a fluorine atom, and a nitro group.
[0009] In some embodiments, the electron withdrawing group is a cyano group or an ethoxy group.
[0010] In some embodiments, the dispersion matrix includes at least one of polymethyl methacrylate, polyvinyl alcohol, polyacrylamide, and cyclodextrin.
[0011] In some embodiments, the molar ratio of the dispersed matrix to the near-infrared phosphorescent dye is 10-10000:1.
[0012] In some embodiments, the phosphorescence emission wavelength of the organic near-infrared room temperature phosphorescent material at room temperature is greater than 700 nm, and the Stokes shift of the organic near-infrared room temperature phosphorescent material at room temperature is greater than 300 nm.
[0013] In a second aspect, the present application provides a method for preparing an organic near-infrared room temperature phosphorescent material, comprising the following steps:
[0014] (1) dissolving a near-infrared phosphorescent dye and a dispersion matrix in a volatile solvent to obtain a mixed solution;
[0015] (2) After the mixed solution is dried, the organic near-infrared room temperature phosphorescent material is obtained.
[0016] In some embodiments, the method for preparing the near-infrared phosphorescent dye in step (1) comprises: using chelidonic acid as a reaction raw material, and obtaining the near-infrared phosphorescent dye after esterification and sulfurization.
[0017] In some embodiments, the volatile solvent in step (1) comprises at least one of methanol, ethanol, dichloromethane, chloroform, water, ethyl acetate, dimethylformamide, and dimethyl sulfoxide.
[0018] In a third aspect, an embodiment of the present application provides a near-infrared light-emitting diode, comprising an organic near-infrared room-temperature phosphorescent material and an ultraviolet light-emitting diode, wherein the organic near-infrared room-temperature phosphorescent material is coated on a housing of the ultraviolet light-emitting diode.
[0019] It can be seen from the above technical scheme that the present specification provides an organic near-infrared room temperature phosphorescent material based on a small molecular weight phosphorescent dye, wherein the near-infrared phosphorescent dye (comprising a thiocarbonyl group and an auxiliary electron-withdrawing group) is doped with a dispersed matrix, and the organic near-infrared room temperature phosphorescent material is obtained by the lowering effect of the triplet energy level and the rigidification effect of the matrix. The organic near-infrared room temperature phosphorescent material utilizes the characteristic that the lone electron pairs of the thiocarbonyl group are weakly attracted to the atomic nucleus, combined with the electron-withdrawing characteristics of the electron-withdrawing group, to reduce the triplet energy level, thereby achieving near-infrared room temperature phosphorescence while maintaining an ultra-low molecular weight; and the organic near-infrared room temperature phosphorescent material has good processability and can be conveniently applied to the surface of irregular objects, such as ultraviolet light-emitting diodes. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. 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 work.
[0021] Figure 1 The absorption and phosphorescence emission spectra of the phosphorescent material provided in Example 1 of the present application are shown;
[0022] Figure 2 The absorption and phosphorescence emission spectra of the phosphorescent material provided in Example 2 of the present application are shown;
[0023] Figure 3 The electroemission spectrum of the light-emitting diode with near-infrared emission provided in Example 3 of the present application is shown;
[0024] Figure 4 The electroemission spectrum of the light-emitting diode with near-infrared emission provided in Example 4 of the present application is shown. DETAILED DESCRIPTION
[0025] In order to facilitate the understanding of this specification, the specification will be described more fully below with reference to the relevant drawings. The preferred embodiments of this specification are given in the drawings. However, this specification can be implemented in many different forms without departing from the core spirit of this specification and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of this specification more thorough and comprehensive.
[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this specification belongs. The terms used herein in this specification are only for the purpose of describing specific embodiments and are not intended to limit this specification. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0027] In a first aspect, an embodiment of the present application provides an organic near-infrared room temperature phosphorescent material, comprising a near-infrared phosphorescent dye and a dispersed matrix, wherein the near-infrared phosphorescent dye comprises a thiocarbonyl group and an auxiliary electron-withdrawing group, and the chemical structure of the near-infrared phosphorescent dye is shown in formula (I):
[0028]
[0029] Among them, EWG is an auxiliary electron-withdrawing group.
[0030] An embodiment of the present application provides an organic near-infrared room temperature phosphorescent material based on a small molecular weight phosphorescent dye, wherein the near-infrared phosphorescent dye (comprising a thiocarbonyl group and an auxiliary electron-withdrawing group) is doped with a dispersed matrix, and the organic near-infrared room temperature phosphorescent material is obtained by lowering the triplet energy level and rigidifying the matrix. The organic near-infrared room temperature phosphorescent material utilizes the property that the lone electron pair of the thiocarbonyl group is weakly attracted to the atomic nucleus, combined with the electron-withdrawing property of the electron-withdrawing group, to reduce the triplet energy level, thereby achieving near-infrared room temperature phosphorescence while maintaining an ultra-low molecular weight; moreover, the organic near-infrared room temperature phosphorescent material has good processability and can be conveniently coated on the surface of irregular objects, such as ultraviolet light-emitting diodes.
[0031] In some embodiments of the present application, the electron withdrawing group includes at least one of a cyano group, an ethoxyl group, an alkynyl group, a trifluoromethyl group, a fluorine atom, and a nitro group.
[0032] Specifically, the chemical structural formulas of the near-infrared phosphorescent dyes provided in the embodiments of the present application are shown in formulas (II)-(VII).
[0033]
[0034]
[0035] The above-mentioned near-infrared phosphorescent dyes are all monocyclic phosphorescent dyes with extremely small molecular weights. After being doped with a dispersed matrix, an organic near-infrared room temperature phosphorescent material can be obtained through the reduction of the triplet energy level and the rigidification of the matrix. The obtained organic near-infrared room temperature phosphorescent material can achieve near-infrared room temperature phosphorescence while maintaining an ultra-low molecular weight. Compared with traditional phosphorescent materials prepared based on inorganic or metal organic compounds, the components of this organic near-infrared room temperature phosphorescent material are all organic compounds, without the participation of heavy metals and condensed ring aromatic hydrocarbons, and are easy to prepare. Amorphous materials with good processability can be obtained, and the cost and toxicity are low.
[0036] Among them, "amorphous" means that the molecules of the substance have no regularity and periodicity, but are arranged in disorder. The amorphous product state is conducive to further processing.
[0037] In some embodiments of the present application, the electron-withdrawing group is a cyano group or an ethoxylated group. When the electron-withdrawing group is a cyano group, the chemical structural formula of the near-infrared phosphorescent dye is shown in formula (II). When the electron-withdrawing group is an ethoxylated group, the chemical structural formula of the near-infrared phosphorescent dye is shown in formula (III),
[0038] In some embodiments of the present application, the dispersion matrix includes at least one of polymethyl methacrylate, polyvinyl alcohol, polyacrylamide, and cyclodextrin.
[0039] Through a large number of experiments, it is found that the selection of the dispersing matrix can be determined according to the sensitivity of the thiocarbonyl group in the near-infrared phosphorescent dye to weak nucleophilic reagents. For example, when the near-infrared phosphorescent dye is of formula (II) or formula (III), polymethyl methacrylate can be used as the dispersing matrix.
[0040] In some embodiments of the present application, the molar ratio of the dispersed matrix and the near-infrared phosphorescent dye is 10-10000:1. For example, the molar ratio of the dispersed matrix and the near-infrared phosphorescent dye can be 10:1, 100:1, 500:1, 1000:1, 2000:1, 4000:1, 6000:1, 8000:1, 10000:1, or any molar ratio between any two of the above molar ratios.
[0041] Further, the molar ratio of the dispersed matrix to the near-infrared phosphorescent dye can be 100-1000:1, for example, the molar ratio of the dispersed matrix to the near-infrared phosphorescent dye can be 100:1, 200:1, 300:1, 400:1, 500:1, 600:1, 700:1, 800:1, 900:1, 1000:1, or any molar ratio between any two of the above molar ratios.
[0042] In the embodiments of the present application, the emission wavelength or other properties of the phosphorescent material can be regulated by adjusting the molar ratio between the dispersed matrix and the near-infrared phosphorescent dye.
[0043] In some embodiments of the present application, the phosphorescence emission wavelength of the organic near-infrared room temperature phosphorescent material at room temperature is greater than 700 nm, and the Stokes shift of the organic near-infrared room temperature phosphorescent material at room temperature is greater than 300 nm.
[0044] Stokes shift refers to the difference between the strongest wavenumber or wavelength of the same electronic transition in the absorption spectrum and the emission spectrum. The organic near-infrared room temperature phosphorescent material provided in the embodiment of the present application has a very large Stokes shift due to its forbidden S0→S1 transition. For example, the Stokes shift can be 301nm, 350nm, 403nm, 405nm, 410nm, or other displacement values greater than 300nm. On this basis, the organic near-infrared room temperature phosphorescent material provided in the embodiment of the present application can have a phosphorescence emission wavelength greater than 700nm at room temperature (18-27°C). For example, the phosphorescence emission wavelength can be 701nm, 702nm, 703nm, 704nm, 710nm, 750nm, 760nm, or other wavelength values greater than 700nm.
[0045] In a second aspect, the present application provides a method for preparing an organic near-infrared room temperature phosphorescent material, comprising the following steps:
[0046] (1) dissolving a near-infrared phosphorescent dye and a dispersion matrix in a volatile solvent to obtain a mixed solution;
[0047] (2) After the mixed solution is dried, an organic near-infrared room temperature phosphorescent material is obtained.
[0048] In step (2), the mixed solution can be placed in a container or applied to the surface of an object, and dried at a temperature of -100°C to 150°C in a vacuum to normal pressure environment. The drying time depends on the specific situation. For example, the drying time can be 10 minutes to 10 days.
[0049] In some embodiments of the present application, the preparation method of the near-infrared phosphorescent dye in step (1) comprises: using chelidonic acid as a reaction raw material, and obtaining the near-infrared phosphorescent dye after esterification and sulfurization. In the embodiments of the present application, the near-infrared phosphorescent dye can be synthesized from natural products, for example, the near-infrared phosphorescent dye can be obtained from chelidonic acid (a natural product derived from chelidonium) after esterification and sulfurization.
[0050] In some embodiments of the present application, the volatile solvent in step (1) includes at least one of methanol, ethanol, dichloromethane, chloroform, water, ethyl acetate, dimethylformamide, and dimethyl sulfoxide.
[0051] In a third aspect, an embodiment of the present application provides a near-infrared light-emitting diode, comprising an organic near-infrared room-temperature phosphorescent material and an ultraviolet light-emitting diode, wherein the organic near-infrared room-temperature phosphorescent material is coated on a shell of the ultraviolet light-emitting diode.
[0052] The following are specific preparation examples involved in the above content of the present disclosure. It should be clear that the following examples are only for illustrating the organic near-infrared room temperature phosphorescent material and its preparation method, and near-infrared light-emitting diode disclosed above, and the specific implementation methods and parameters used therein are only one or several methods in accordance with the many processes and methods described above. Those skilled in the art can use other parameters according to the content introduced in this specification to prepare organic near-infrared room temperature phosphorescent materials and near-infrared light-emitting diodes according to the above method without deviating from the core spirit disclosed in the application.
[0053] Example 1
[0054] This embodiment provides an organic near-infrared room temperature phosphorescent material, and the preparation method includes the following steps:
[0055] (1) reflux chelidonic acid in 0.83 M hydrogen chloride in ethanol solution for 24 hours under argon protection, and purify by silica gel chromatography to obtain an esterification product;
[0056] (2) reflux the esterification product in benzene with 1.2 equivalents of tetraphosphorus decasulfide for 35 minutes, and purify by silica gel chromatography to obtain a near-infrared phosphorescent dye, wherein the near-infrared phosphorescent dye is as shown in formula (III) and has a thiocarbonyl group and an electron-withdrawing group (ethoxyacyl group);
[0057] (3) Dissolving the near-infrared phosphorescent dye prepared in step (2) and 100 times the mass of polymethyl methacrylate in 200 times the mass of dichloromethane, pouring the solution into a culture dish with a diameter of about 5 cm, placing the culture dish in a controllable vacuum to evaporate the solvent, and then placing it in a high vacuum to dry, to obtain an organic near-infrared room temperature phosphorescent material.
[0058] Figure 1 The absorption and phosphorescence emission spectra of the organic near-infrared room temperature phosphorescent material provided in Example 1 are shown. Figure 1 As shown, the absorption peak of the organic near-infrared room temperature phosphorescent material prepared in Example 1 is located at about 355nm (such as Figure 1 The phosphorescence emission peak is located at 704 nm (as shown by the dotted line). Figure 1 The solid line shows the Stokes shift of 13964 cm -1 (349nm).
[0059] Example 2
[0060] This embodiment provides an organic near-infrared room temperature phosphorescent material, and the preparation method includes the following steps:
[0061] (1) The esterification product obtained in step (1) of Example 1 was placed in 20% ammonia water at 0° C. and stirred for 1 hour, then placed in a 4.9 equivalent trifluoroacetic anhydride dioxane solution and stirred at room temperature for 24 hours, and purified by silica gel chromatography to obtain chelidonitrile;
[0062] (2) reflux chelidonitrile with 1.2 equivalents of tetraphosphorus decasulfide in benzene for 35 minutes, and purify by silica gel chromatography to obtain a near-infrared phosphorescent dye, wherein the near-infrared phosphorescent dye is as shown in formula (II) and has a thiocarbonyl group and an electron-withdrawing group (cyano group);
[0063] (3) Dissolve the near-infrared phosphorescent dye prepared in step (2) and 100 times the mass of polymethyl methacrylate in 200 times the mass of dichloromethane, and pour the solution into a culture dish with a diameter of about 5 cm. Place the culture dish in a controlled vacuum to evaporate the solvent, and then place it in a high vacuum to dry, to obtain an organic near-infrared room temperature phosphorescent material.
[0064] Figure 2 The absorption and phosphorescence emission spectra of the organic near-infrared room temperature phosphorescent material provided in Example 2 are shown. Figure 2 As shown, the absorption peak of the organic near-infrared room temperature phosphorescent material prepared in Example 2 is located at about 347nm (such as Figure 2The phosphorescence emission peak is located at 750nm (as shown by the dotted line). Figure 2 The solid line shows the Stokes shift of 15485 cm -1 (403nm).
[0065] Example 3
[0066] This embodiment provides a near-infrared light-emitting diode, and the preparation method includes the following steps:
[0067] (1) dropping a mixed dichloromethane solution of the near-infrared phosphorescent dye prepared in step (2) of Example 1 and polymethyl methacrylate onto the housing of a UV light-emitting diode, and purging with argon for 15 seconds, and repeating this step 5 times;
[0068] (2) The culture dish is placed in a controlled vacuum to evaporate the solvent, and then placed in a high vacuum to dry, thereby obtaining a light-emitting diode with near-infrared emission.
[0069] Figure 3 The electro-emission spectrum of the near-infrared light-emitting diode provided in Example 3 is shown. Figure 3 As shown, the unabsorbed visible light component in the ultraviolet LED spectrum and the near-infrared emission component around 704nm can be observed.
[0070] Example 4
[0071] This embodiment provides a near-infrared light-emitting diode, and the preparation method includes the following steps:
[0072] (1) dropping a mixed dichloromethane solution of the near-infrared phosphorescent dye and polymethyl methacrylate prepared in step (2) of Example 2 onto the housing of a UV light-emitting diode, and purging with argon for 15 seconds, and repeating this step 5 times;
[0073] (2) The culture dish is placed in a controlled vacuum to evaporate the solvent, and then placed in a high vacuum to dry, thereby obtaining a light-emitting diode with near-infrared emission.
[0074] Figure 4 The electro-emission spectrum of the near-infrared light-emitting diode provided in Example 4 is shown. Figure 4 As shown, the unabsorbed visible light component in the UV LED spectrum and the near-infrared emission component around 750nm can be observed.
[0075] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0076] The above-described embodiments only express several embodiments of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided by the present invention are all within the protection scope of the claims attached to the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims, and the description and drawings may be used to interpret the contents of the claims.
Claims
1. An organic near-infrared room temperature phosphorescent material, characterized in that: It comprises a near-infrared phosphorescent dye and a dispersed matrix, wherein the near-infrared phosphorescent dye comprises a thiocarbonyl group and an auxiliary electron-withdrawing group, and the chemical structural formula of the near-infrared phosphorescent dye is shown in formula (I): Among them, EWG is an auxiliary electron-withdrawing group.
2. The organic near-infrared room temperature phosphorescent material according to claim 1, characterized in that: The electron withdrawing group includes at least one of a cyano group, an ethoxyl group, an alkynyl group, a trifluoromethyl group, a fluorine atom, and a nitro group.
3. The organic near-infrared room temperature phosphorescent material according to claim 2, characterized in that: The electron withdrawing group is a cyano group or an ethoxyacyl group.
4. The organic near-infrared room temperature phosphorescent material according to claim 1, characterized in that: The dispersion matrix includes at least one of polymethyl methacrylate, polyvinyl alcohol, polyacrylamide and cyclodextrin.
5. The organic near-infrared room temperature phosphorescent material according to claim 1, characterized in that: The molar ratio of the dispersed matrix to the near-infrared phosphorescent dye is 10-10000:
1.
6. The organic near-infrared room temperature phosphorescent material according to claim 1, characterized in that: The phosphorescence emission wavelength of the organic near-infrared room temperature phosphorescent material at room temperature is greater than 700 nm, and the Stokes shift of the organic near-infrared room temperature phosphorescent material at room temperature is greater than 300 nm.
7. A method for preparing an organic near-infrared room temperature phosphorescent material, characterized in that: The following steps are involved: (1) dissolving a near-infrared phosphorescent dye and a dispersion matrix in a volatile solvent to obtain a mixed solution; (2) After the mixed solution is dried, the organic near-infrared room temperature phosphorescent material is obtained.
8. The method for preparing an organic near-infrared room temperature phosphorescent material according to claim 7, characterized in that: The preparation method of the near-infrared phosphorescent dye in step (1) comprises: taking chelidonic acid as a reaction raw material, and obtaining the near-infrared phosphorescent dye after esterification and sulfurization.
9. The method for preparing an organic near-infrared room temperature phosphorescent material according to claim 7, characterized in that: The volatile solvent in step (1) includes at least one of methanol, ethanol, dichloromethane, chloroform, water, ethyl acetate, dimethylformamide and dimethyl sulfoxide.
10. A near-infrared light-emitting diode, characterized in that: The invention comprises an organic near-infrared room temperature phosphorescent material and an ultraviolet light emitting diode, wherein the organic near-infrared room temperature phosphorescent material is coated on the outer shell of the ultraviolet light emitting diode.