Silver complex luminescent material, preparation method and application

Abstract

The present invention provides a silver complex luminescent material, a preparation method and an application thereof; the general chemical formula of the silver complex luminescent material is C 60 H 44 Ag2Br2N4P4S2, whose structural formula is shown below: #imgabs0#. The luminescent silver complex obtained in this application has excellent performance and can be used in the light-emitting layer of organic electroluminescent devices and optical sensors, showing broad application prospects and significant application value.

Description

Technical Field

[0001] The present application relates to the technical field of synthesis of complex-type luminescent functional materials, and in particular to a silver complex luminescent material, a preparation method and an application thereof. Background Art

[0002] Silver ions belong to d 10 The electronic configuration and coordination mode are very flexible and can form a rich structure, showing excellent optoelectronic properties and biological characteristics. They have important and extensive applications in the fields of luminescence, catalysis and antibacterial. Especially in the field of luminescence, silver complexes can realize high-performance organic electroluminescent devices and are considered to be alternatives to precious metal iridium and platinum phosphorescent materials. At the same time, luminescent silver complexes also have important application value in optical sensors. Therefore, the development of silver complex-based luminescent functional materials has important significance and economic value. However, the preparation process of silver complex luminescent materials is complex and highly polluting. In addition, the photoluminescence quantum yield is low, and it is difficult to obtain stable and efficient OLED blue light materials. Summary of the Invention

[0003] In view of the above-mentioned prior art, at least one of the above-mentioned technical problems is solved. The luminescent silver complex obtained in this application has excellent performance and can be applied to the light-emitting layer of organic electroluminescent devices and can also be used in optical sensors. It has broad application prospects and important application value.

[0004] The present invention provides a silver complex luminescent material, the general chemical formula of which is C 60 H 44 Ag2Br2N4P4S2, its structural formula is shown below

[0005] .

[0006] In some embodiments, the silver complex luminescent material is AgLBr; it uses a benzothiadiazole bisphosphine compound L as a ligand; AgBr is a silver source; the silver complex is a stable Y-shaped structure formed by the coordination of the central soft acid metal ion Ag(I) and the soft base coordinating atom P in the ligand L and the bromide ion.

[0007] In some embodiments, the silver complex luminescent material has a symmetrical binuclear structure, and the angle between P-Ag-P is 128.74(4)°.

[0008] In some embodiments, a method for preparing a silver complex luminescent material is provided, comprising the following steps:

[0009] Dissolve 4,7-difluorobenzothiadiazole in a solvent, add potassium diphenyl phosphate, and reflux for 7 hours; cool to room temperature, and evaporate to remove the solvent to obtain a crude product;

[0010] Recrystallization with methanol gave a benzothiadiazole bisphosphine compound L;

[0011] The benzothiadiazole bisphosphine compound L and silver bromide are added to a mixed solvent and stirred for reaction for 2-3 hours. The solvent is evaporated and concentrated, and then filtered to obtain AgLBr; wherein the mixed solvent includes dichloromethane and methanol in a volume ratio of 4-2:1.

[0012] The volume ratio of the mixed solvent composed of dichloromethane and methanol can be: 30mL:10mL (V:V)-50mL:10mL (V:V), which has no obvious effect on the synthesis of the compound, but the cost increases slightly due to the increase in the amount of dichloromethane used, and the amount of waste liquid increases.

[0013] In some embodiments, the molar ratio of the potassium diphenyl phosphate to the 4,7-difluorobenzothiadiazole is greater than or equal to 2.

[0014] However, when the molar ratio of potassium diphenyl phosphate to 4,7-difluorobenzothiadiazole is less than 2, 4,7-difluorobenzothiadiazole remains, affecting the purity and yield of the product during subsequent methanol recrystallization; wherein the molar ratio of potassium diphenyl phosphate to 4,7-difluorobenzothiadiazole is preferably 2.05.

[0015] In some embodiments, the solvent is tetrahydrofuran, and the addition ratio of the 4,7-difluorobenzothiadiazole to the solvent is 0.1-0.25 mmol / mL.

[0016] The addition ratio of 4,7-difluorobenzothiadiazole to the solvent may be in the range of 0.1-0.25 mmol / mL, preferably 0.2 mmol / mL.

[0017] In some embodiments, the solvent is removed by evaporation and the solvent is recovered by rotary evaporation.

[0018] In some embodiments, the molar ratio of the benzothiadiazole bisphosphine compound L to silver bromide is 1:1.

[0019] In some embodiments, an organic light-emitting diode is provided, comprising a solid film in which the silver complex luminescent material described in any of the above embodiments is dispersed; wherein the chemical formula of the silver complex luminescent material is C 60 H 44 Ag2Br2N4P4S2, its structural formula is shown below

[0020] .

[0021] In some embodiments, the solid film is polymethyl methacrylate, wherein the mass percentage of the silver complex luminescent material is 5% based on the mass of the solid film.

[0022] The silver complex luminescent material, preparation method and application proposed in this application have the following beneficial effects compared with the prior art:

[0023] (1) The preparation method of the silver complex with excellent photoluminescent properties provided by the present invention is simple, the total yield can reach 70%, and it is easy to produce on a large scale. In addition, the organic solvent used in the reaction can be recycled and reused, resulting in low pollution.

[0024] (2) At 298 K, the maximum emission wavelength of the solid powder of the silver complex is 541 nm, and the photoluminescence quantum yield is 35%. Of particular importance is that the emission wavelength of the polymethyl methacrylate (PMMA) film containing 5% AgLBr by mass is 486 nm, and the photoluminescence quantum yield is 23%.

[0025] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0027] Figure 1 These are photos of the solid film in this application under visible light and ultraviolet light respectively;

[0028] Figure 2 The single crystal structure diagram of the silver complex AgLBr in this application;

[0029] Figure 3 is the UV-visible absorption spectrum of the silver complex AgLBr and ligand L in dichloromethane solution in this application;

[0030] Figure 4 is the solid-state UV-visible absorption spectrum of the silver complex AgLBr in this application;

[0031] Figure 5 Photoluminescence spectrum (left) and chromaticity coordinate (CIE) diagram (right) of the silver complex AgLBr solid powder of this application;

[0032] Figure 6 The photoluminescence spectrum (left) and chromaticity coordinate (CIE) diagram (right) of the emitted light of the solid film containing 5% AgLBr mass fraction in this application. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments, and are not intended to limit the scope of disclosure of the present application. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts disclosed in the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of this application.

[0034] The accompanying drawings illustrate schematic diagrams of the structures of the embodiments disclosed herein. These figures are not drawn to scale; for the purpose of clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0035] The present application provides a method for preparing a silver complex luminescent material, including the following steps:

[0036] Dissolving 4,7-difluorobenzothiadiazole in a solvent, wherein the solvent is tetrahydrofuran, and the addition ratio of 4,7-difluorobenzothiadiazole to the solvent is 0.2 mmol / mL; adding potassium diphenyl phosphate to the dissolved 4,7-difluorobenzothiadiazole and reacting under reflux for 7 hours, wherein the molar ratio of 4,7-difluorobenzothiadiazole to potassium diphenyl phosphate is 1:2.05; cooling to room temperature, evaporating the solvent by rotary evaporation, and recovering the solvent to obtain a crude product; and recrystallizing the crude product from methanol to obtain a benzothiadiazole bisphosphine compound L;

[0037] The synthetic route of benzothiadiazole bisphosphine compound L is .

[0038] Add benzothiadiazole bisphosphine compound L and silver bromide in a molar ratio of 1:1 to a mixed solvent and stir to react for 2-3 hours. After evaporation and concentration of the solvent, filter to obtain AgLBr. The mixed solvent includes dichloromethane and methanol in a volume ratio of 3:1. The synthesis route of the silver complex AgLBr is as follows: .

[0039] For example, at room temperature and pressure, 10.0 mmol, 1.72 g of 4,7-difluorobenzothiadiazole was dissolved in 50.0 mL of tetrahydrofuran (THF), and then 20.5 mmol, 22.0 mL of potassium diphenylphosphate was slowly added. The mixture was refluxed for 7 hours. After cooling to room temperature, the solvent was evaporated to obtain a crude product, which was then recrystallized from methanol to obtain 8.49 mmol, 4.28 g of ligand L. The calculated yield of ligand L was 85%. Elemental analysis of ligand L showed that the product was C 30 H 22 N2P2S, theoretical value (%): C, 71.42; H, 4.40; N, 5.55; experimental value (%): C, 71.49; H, 4.37; N, 5.50.

[0040] 2.00 mmol, 1.01 g of the ligand L prepared above, 2.00 mmol, and 0.376 g of silver bromide were added to a mixed solvent consisting of 30 mL of dichloromethane and 10 mL of methanol. The mixture was stirred for 3 h. The solvent was evaporated and filtered to obtain 0.82 mmol of the silver compound and 1.14 g of AgLBr. The yield of AgLBr was calculated to be 82%. Elemental analysis of AgLBr was performed. 60 H 44 Ag2Br2N4P4S2, theoretical (%): C, 52.05; H, 3.20; N, 4.05; experimental (%): C, 51.98; H, 3.17; N, 4.09. Thermal evaporation of the solid product, AgLBr, allows for the simultaneous recovery of the reaction solvent. The filtered mother liquors can be combined and concentrated to yield more AgLBr. Therefore, industrial production can further improve product yield.

[0041] The silver complex luminescent material prepared in the above embodiment has the general chemical formula C 60 H 44 Ag2Br2N4P4S2, its structural formula is shown below

[0042] .

[0043] The silver complex luminescent material is AgLBr; the benzothiadiazole bisphosphine compound L is used as a ligand; AgBr is used as a silver source to obtain the target silver complex AgLBr; the structural formula of the benzothiadiazole bisphosphine compound L is (Ligand L). The silver complex obtained in this example is a stable Y-shaped structure formed by the coordination of the central soft acid metal ion Ag(I) with the soft base coordinating atom P in the ligand L and the bromide ion.

[0044] In some embodiments, the silver complex luminescent material has a symmetrical binuclear structure, and the angle between P-Ag-P is 128.74(4)°.

[0045] Specifically, the structure of the silver complex AgLBr was determined using a Bruker APEX-II CCD X-ray single crystal diffractometer, and some of the crystallographic parameters are shown in Table 1. Diffraction data were collected at 296 K using Mo-Kα radiation (λ = 0.7103 Å) with a graphite monochromator. Absorption correction was performed using the SADABS program. The resulting structural data were analyzed and refined using ShelXT and ShelXS in the OLEX2 program package, and the hydrogen atom positions were obtained using the theoretical hydrogenation method. The crystallographic parameters of the silver complex AgLBr are shown in Table 1.

[0046] Table 1 Crystallographic parameters of silver complex AgLBr

[0047]

[0048] The silver complex AgLBr in this embodiment is a symmetrical binuclear structure, in which each Ag(I) is coordinated with two ligands P and Br. - ion coordination, thus forming a planar triangular structure. Figure 2 As shown in the single crystal structure of the silver complex, there is a dichloromethane molecule. Due to the steric effect, the angle between P-Ag-P is slightly larger than 120 o , is 128.74(4)º. In the obtained single crystal structure, there are lattice dichloromethane molecules (C 61 H 46 Ag2Br2Cl2N4P4S2), this solvent molecule can be easily lost, for example, during storage or drying, and therefore does not affect subsequent property determination.

[0049] In some embodiments, the photophysical properties of the silver complex AgLBr were tested, and the results were as follows:

[0050] (1) UV-visible absorption spectrum

[0051] At room temperature 298 K, the UV-visible absorption spectra of the silver complex AgLBr solution and the ligand L solution were measured using a Hitachi UV-visible near-infrared spectrophotometer UH4150. The UV-visible absorption spectra of the silver complex AgLBr solution and the ligand L solution are as follows: Figure 3 It is obvious that the absorption spectrum of the complex AgLBr is very similar to the absorption of the ligand L itself, indicating that the absorption of the complex mainly depends on the absorption properties of the ligand L.

[0052] In addition, the UV-visible absorption spectrum of the silver complex AgLBr was measured. Figure 4 As shown, Figure 4 It can be seen that the silver complex AgLBr in the solid powder state has a strong broad peak absorption in the UV-visible absorption spectrum between 300-500 nm due to the interaction between molecules.

[0053] (2) Photoluminescence properties of silver complex AgLBr

[0054] The photoluminescence properties of the silver complex AgLBr were measured at 298 K using a HORIBA Fluorolog-3 fluorescence spectrometer. Figure 5 As shown in the figure, the maximum excitation wavelength of the silver complex AgLBr powder is 390 nm, and the maximum emission wavelength is 541 nm; the photoluminescence quantum efficiency reaches 35%, which proves that it is an excellent green light-emitting material.

[0055] In some embodiments, an organic light-emitting diode is provided, which includes a solid film in which the silver complex luminescent material of any of the above embodiments is dispersed; wherein the chemical formula of the silver complex luminescent material is C 60 H 44 Ag2Br2N4P4S2, its structural formula is shown below:

[0056] .

[0057] In some embodiments, the solid film is polymethyl methacrylate, wherein the mass percentage of the silver complex luminescent material is 5% based on the mass of the solid film.

[0058] A small amount of dichloromethane was added to a certain amount of polymethyl methacrylate (PMMA), and after dissolving, a small amount of silver complex AgLBr was added. After stirring and dissolving, the solution was evaporated to obtain a solid film containing 5% of silver complex AgLBr. Figure 1 Figure 3 shows photos of a solid film containing 5% AgLBr under visible light and ultraviolet light, respectively.

[0059] The photoluminescence properties of the solid film were measured using a HORIBA Fluorolog-3 fluorescence spectrometer at 298 K. Figure 6 It can be seen that the maximum excitation wavelength of this solid film is 372 nm, the maximum emission wavelength is 496 nm, and the photoluminescence quantum efficiency reaches 23%. It is a type of high-performance blue-green luminescent material and has important uses in organic electroluminescence, anti-counterfeiting and luminescent coatings.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0062] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A silver complex luminescent material, characterized in that: Its chemical formula is C 60 H 44 Ag2Br2N4P4S2, its structural formula is shown below 2. The silver complex luminescent material according to claim 1, wherein The silver complex luminescent material is AgLBr; it uses a benzothiadiazole diphosphine compound L as a ligand; AgBr is a silver source; the silver complex is a stable Y-shaped structure formed by the coordination of a central soft acid metal ion Ag(I) and a soft base coordination atom P in the ligand L and a bromide ion.

3. The silver complex luminescent material according to claim 1, characterized in that The silver complex luminescent material has a symmetrical binuclear structure, and the angle between P-Ag-P is 128.74(4)°.

4. A method for preparing the silver complex luminescent material as claimed in claim 2 or 3, characterized in that: The following steps are involved: Dissolve 4,7-difluorobenzothiadiazole in a solvent, add potassium diphenyl phosphate, and reflux for 7 hours; cool to room temperature, and evaporate to remove the solvent to obtain a crude product; Recrystallization with methanol gave a benzothiadiazole bisphosphine compound L; The benzothiadiazole bisphosphine compound L and silver bromide are added to a mixed solvent and stirred for reaction for 2-3 hours. The solvent is evaporated and concentrated, and then filtered to obtain AgLBr; wherein the mixed solvent is dichloromethane and methanol with a volume ratio of 4-2:

1.

5. The preparation method according to claim 4, characterized in that The molar ratio of the potassium diphenyl phosphate to the 4,7-difluorobenzothiadiazole is equal to 2.

6. The preparation method according to claim 4, characterized in that The solvent is tetrahydrofuran, and the addition ratio of the 4,7-difluorobenzothiadiazole to the solvent is 0.1-0.25 mmol / mL.

7. The preparation method according to claim 4, characterized in that The solvent is removed by evaporation and recovered by rotary evaporation.

8. The preparation method according to claim 4, characterized in that The molar ratio of the benzothiadiazole bisphosphine compound L to silver bromide is 1:

1.

9. An organic light emitting diode, characterized in that: comprising a solid film in which the silver complex luminescent material according to any one of claims 1 to 3 is dispersed; The chemical formula of the silver complex luminescent material is C 60 H 44 Ag2Br2N4P4S2, its structural formula is shown below 10. The organic light emitting diode according to claim 9, characterized in that: The solid film is polymethyl methacrylate, wherein the mass percentage of the silver complex luminescent material is 5% based on the mass of the solid film.

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