Room temperature phosphorescent material based on pyridine-substituted triphenylamine derivatives and preparation method and application thereof

Abstract

The present invention discloses a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative, as well as its preparation method and application. The preparation method comprises: dispersing polyvinyl alcohol or polymethyl methacrylate in a solvent to obtain a polyvinyl alcohol solution or a polymethyl methacrylate solution; dispersing a triphenylamine derivative containing a pyridine group in the polyvinyl alcohol solution or the polymethyl methacrylate solution to obtain a mixed solution; and annealing the mixed solution to obtain the room temperature phosphorescent material based on the pyridine-substituted triphenylamine derivative. The present invention obtains the corresponding room temperature phosphorescent material by doping a small molecule of a pyridine-substituted triphenylamine derivative into different polymers that do not inherently exhibit room temperature phosphorescence. For example, when the small molecule is doped into polyvinyl alcohol, the presence of hydrogen bonding can suppress the non-radiative transition of triplet excitons, inducing ultra-long pure organic room temperature phosphorescence, and exhibiting reversible responses to humidity and temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and in particular to a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative, and a preparation method and application thereof. Background Art

[0002] Phosphorescent materials, that is, materials that can still emit light when the excitation source is stopped, usually have a long luminescence lifetime and high luminescence efficiency. In recent years, they have shown potential application value in light-emitting devices, biological imaging, and multiple anti-counterfeiting.

[0003] Doping is a simple and convenient method for producing amorphous room-temperature phosphorescent materials. The raw materials used are inexpensive and readily available, and the emission color and lifetime can be easily manipulated by the doping guest. However, current amorphous room-temperature phosphorescent materials obtained through doping suffer from a monotonous molecular structure, unclear structure-activity relationships, and low phosphorescence quantum yields.

[0004] Therefore, the existing technology needs to be further improved and enhanced. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a room temperature phosphorescent material based on pyridine-substituted triphenylamine derivatives and its preparation method and application, aiming to solve the problem of low phosphorescence quantum yield of existing room temperature phosphorescent materials.

[0006] A method for preparing a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative, comprising:

[0007] dispersing polyvinyl alcohol or polymethyl methacrylate in a solvent to obtain a polyvinyl alcohol solution or a polymethyl methacrylate solution;

[0008] dispersing a triphenylamine derivative containing a pyridine group in the polyvinyl alcohol solution or the polymethyl methacrylate solution to obtain a mixed solution;

[0009] The mixed solution is subjected to annealing treatment to obtain the room temperature phosphorescent material based on the pyridine-substituted triphenylamine derivative.

[0010] Optionally, the preparation method of the room temperature phosphorescent material based on pyridine-substituted triphenylamine derivatives, wherein the triphenylamine derivative containing a pyridine group is selected from

[0011] One or more of the above, the triphenylamine derivative containing a pyridine group is the guest, and polyvinyl alcohol (PVA) or polymethyl methacrylate (PMMA) is the host.

[0012] Optionally, in the method for preparing the room temperature phosphorescent material based on pyridine-substituted triphenylamine derivatives, the mass ratio of the polyvinyl alcohol or polymethyl methacrylate to the triphenylamine derivative containing a pyridine group is (100:1)-(10:1).

[0013] Optionally, in the method for preparing the room temperature phosphorescent material based on pyridine-substituted triphenylamine derivatives, the annealing temperature is 60-80°C.

[0014] Optionally, in the method for preparing the room temperature phosphorescent material based on pyridine-substituted triphenylamine derivatives, the polyvinyl alcohol is dispersed in water to obtain a polyvinyl alcohol solution, and the polymethyl methacrylate is dispersed in an organic solvent to obtain a polymethyl methacrylate solution.

[0015] Optionally, in the method for preparing the room temperature phosphorescent material based on pyridine-substituted triphenylamine derivatives, the annealing time is 50-75 minutes.

[0016] A room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative is prepared by using the above-mentioned method for preparing a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative.

[0017] An application of a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative, wherein the room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative is used to prepare an organic light-emitting device.

[0018] An application of a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative, wherein the room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative is used for an anti-counterfeiting mark.

[0019] Beneficial effects: Compared with the prior art, the present invention enables polyvinyl alcohol or polymethyl methacrylate, which does not have phosphorescence, to emit phosphorescence by doping the pyridine-substituted triphenylamine derivative into the non-phosphorescent polyvinyl alcohol or polymethyl methacrylate. The hydrogen bond interaction between the pyridine-substituted triphenylamine derivative and the polyvinyl alcohol or polymethyl methacrylate is used to inhibit the non-radiative transition of the molecule. The phosphorescence quantum yield of the obtained room temperature phosphorescent material reaches 22.5%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the transient / delayed spectrum of the amorphous film M1 in Example 1;

[0021] Figure 2 is the transient / delayed spectrum of the amorphous film M2 in Example 2;

[0022] Figure 3 is the transient / delayed spectrum of the amorphous film M3 in Example 3;

[0023] Figure 4 is the transient / delayed spectrum of the amorphous film M4 in Example 4;

[0024] Figure 5 is the transient / delayed spectrum of the amorphous film M5 in Example 5;

[0025] Figure 6 is the transient / delay spectrum of the amorphous film M6 in Example 6

[0026] Figure 7 is the transient / delay spectrum of the amorphous film M7 in Example 7

[0027] Figure 8 are the fluorescence decay curves of the amorphous films M1, M2, and M3 in Examples 1 to 3;

[0028] Figure 9 are the phosphorescence decay curves of the amorphous films M1, M2, and M3 in Examples 1 to 3;

[0029] Figure 10 are the fluorescence decay curves of the amorphous films M4, M5, M6, and M7 in Examples 4 to 7;

[0030] Figure 11 are the phosphorescence decay curves of the amorphous films M4, M5, M6, and M7 in Examples 4 to 7;

[0031] Figure 12 The delayed fluorescence decay curves obtained by doping M2 materials with different contents of Rhodamine B;

[0032] Figure 13 The delayed fluorescence spectra obtained by doping M2 materials with different contents of Rhodamine B;

[0033] Figure 14 is the pH response and humidity response of the amorphous thin film material M2;

[0034] Figure 15 Different delayed fluorescence colors and delayed fluorescence lifetimes are exhibited for amorphous thin film materials M8-M13;

[0035] Figure 16 The mouse and the cheese in its hand are made of amorphous film materials M2 and M11 respectively. After turning off the UV light, the mouse shows the afterglow of the cheese. After about 2 seconds, the cheese in the mouse's hand disappears, leaving only the phosphorescence of the mouse itself.

[0036] Figure 17 It is an encrypted message, showing "AUORTP". "A" is the non-phosphorescent film material, "U" is the material M13, "O" is the material M9, and "RTP" is the material M2;

[0037] Figure 18 It is a photoactivated image of amorphous thin film materials M4, M5 and M6. No phosphorescence will be displayed without continuous UV light irradiation. When sufficient UV light irradiation is obtained and the UV lamp is turned off, room temperature phosphorescence caused by photoactivation can be obtained. DETAILED DESCRIPTION

[0038] The present invention provides a room-temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative, as well as its preparation method and application. To clarify the objectives, technical solutions, and effects of the present invention, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0039] The preparation method of the room temperature phosphorescent material based on pyridine-substituted triphenylamine derivatives provided by the present invention comprises the following steps:

[0040] S10, dispersing polyvinyl alcohol or polymethyl methacrylate in a solvent to obtain a polyvinyl alcohol solution or a polymethyl methacrylate solution;

[0041] S20, dispersing a triphenylamine derivative containing a pyridine group in the polyvinyl alcohol solution or the polymethyl methacrylate solution to obtain a mixed solution;

[0042] S30, performing annealing treatment on the mixed solution to obtain the room temperature phosphorescent material based on the pyridine-substituted triphenylamine derivative.

[0043] In this embodiment, by selecting a pyridine group as a substituent of a triphenylamine derivative as a guest material, polyvinyl alcohol (PVA) is selected as a host material. At the molecular design level, the nitrogen atom on the pyridine group is utilized to promote the intersystem crossing of the molecule, so that the exciton is more conducive to transitioning from the singlet state to the triplet state. For materials doped with polyvinyl alcohol (PVA), the PVA system is mainly the hydrogen bond formed between the pyridine group and the PVA matrix, which suppresses the non-radiative transition of the molecule and promotes the triplet state to return to the ground state by means of radiative transition, thereby emitting phosphorescence. For materials doped with polymethyl methacrylate (PMMA), the PMMA system is mainly the rigid structure inherent in the polymer matrix itself, which can suppress the non-radiative transition of the molecule. The light activation characteristics it has are achieved by controlling the dissipation of oxygen in the thin film material through illumination. This type of material has an ultra-long room temperature phosphorescence lifetime, and can also be transferred to rhodamine B by energy. By adjusting the different contents of rhodamine B, multi-color regulated long-life delayed fluorescence is achieved.

[0044] The following is a further explanation of the preparation method and properties of a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative of the present invention through specific examples:

[0045] Example 1: Preparation of organic room temperature phosphorescent material M1 (TPA-Py@PVA);

[0046] Weigh 1.50 g of PVA and dissolve it in 50 mL of water. Take 2.33 mL of the solution and add TPA-Py (1 mg). Stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 60°C for 1 h. The amorphous film M1 is obtained. Its transient / delayed spectrum is shown in Figure 2. Figure 1 As shown in the figure, the phosphorescence quantum yield is 5.5%.

[0047] Example 2: Preparation of organic room temperature phosphorescent material M2 (TPA-2Py@PVA);

[0048] Weigh 1.50 g of PVA and dissolve it in 50 mL of water. Take 2.33 mL of the solution and add TPA-2Py (1 mg). Stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 60°C for 1 h. The amorphous film M2 is obtained. Its transient / delayed spectrum is shown in Figure 2. Figure 2 As shown in the figure, the phosphorescence quantum yield is 15.2%.

[0049] Example 3: Preparation of organic room temperature phosphorescent material M3 (TPA-3Py@PVA);

[0050] Weigh 1.50 g of PVA and dissolve it in 50 mL of water. Take 2.33 mL of the solution and add TPA-3Py (1 mg). Stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 60°C for 1 h. The amorphous film M3 is obtained. Its transient / delayed spectrum is shown in Figure 2. Figure 3 As shown in the figure, the phosphorescence quantum yield is 10.0%.

[0051] The main material PMMA was solution-blended with a triphenylamine derivative containing a pyridine group in a mass ratio of 70:1. The annealing temperature was 80°C and the annealing time was 1 hour.

[0052] Example 4: Preparation of organic room temperature phosphorescent material M4 (TPA-Py@PMMA);

[0053] Weigh 1.50 g of PMMA and dissolve it in 50 mL of DMF. Add 1 mg of TPA-Py to 2.33 mL of the solution and stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 80°C for 1 h. The amorphous film M4 is obtained, and its transient / delayed spectrum is shown in Figure 2. Figure 4 As shown in the figure, the phosphorescence quantum yield is 22.5%.

[0054] Example 5: Preparation of organic room temperature phosphorescent material M5 (TPA-2Py@PMMA);

[0055] Weigh 1.50 g of PMMA and dissolve it in 50 mL of DMF. Add 1 mg of TPA-2Py to 2.33 mL of the solution and stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 80°C for 1 h. The amorphous film M5 is obtained, and its transient / delayed spectrum is shown in Figure 2. Figure 5 The phosphorescence quantum yield was tested to be 18.0%.

[0056] Example 6: Preparation of organic room temperature phosphorescent material M6 (TPA-3Py@PMMA).

[0057] Weigh 1.50 g of PMMA and dissolve it in 50 mL of DMF. Add 1 mg of TPA-3Py to 2.33 mL of the solution and stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 80°C for 1 h. The amorphous film M6 is obtained, and its transient / delayed spectrum is shown in Figure 2. Figure 6 As shown in the figure, the phosphorescence quantum yield is 18.2%.

[0058] Example 7: Preparation of organic room temperature phosphorescent material M7 (TPA-2Ph@PMMA).

[0059] Weigh 1.50 g of PMMA and dissolve it in 50 mL of DMF. Add 1 mg of TPA-2Ph to 2.33 mL of the solution and stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 80°C for 1 h. The amorphous film M7 is obtained, and its transient / delayed spectrum is shown in Figure 2. Figure 7 shown.

[0060] The main material PVA was mixed with a triphenylamine derivative containing a pyridine group in a solution, and then different proportions of rhodamine B were added. The mass ratio was 70:1. The annealing temperature was 60℃ and the annealing time was 1 hour.

[0061] Example 8: Preparation of delayed fluorescence and organic room temperature phosphorescent material M8 (TPA-2Py@BR 1%@PVA).

[0062] Weigh 1.50 g of PVA and dissolve it in 50 mL of water. Take 2.33 mL of the solution and add TPA-Py (1 mg). Then add 10 μL of an aqueous solution of rhodamine B (1 mg / mL) and stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 60°C for 1 h to obtain an amorphous film M8.

[0063] Example 9: Preparation of delayed fluorescence and organic room temperature phosphorescent material M9 (TPA-2Py@BR 5%@PVA).

[0064] Weigh 1.50 g of PVA and dissolve it in 50 mL of water. Take 2.33 mL of the solution and add TPA-Py (1 mg). Then add 50 μL of an aqueous solution of rhodamine B (1 mg / mL) and stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 60°C for 1 h to obtain an amorphous film M9.

[0065] Example 10: Preparation of delayed fluorescence and organic room temperature phosphorescent material M10 (TPA-2Py@BR10%@PVA).

[0066] Weigh 1.50 g of PVA and dissolve it in 50 mL of water. Take 2.33 mL of the solution and add TPA-Py (1 mg). Then add 100 μL of an aqueous solution of rhodamine B (1 mg / mL) and stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 60°C for 1 h to obtain an amorphous film M10.

[0067] Example 11: Preparation of delayed fluorescence and organic room temperature phosphorescent material M11 (TPA-2Py@BR15%@PVA).

[0068] Weigh 1.50 g of PVA and dissolve it in 50 mL of water. Take 2.33 mL of the solution and add TPA-Py (1 mg). Then add 150 μL of an aqueous solution of rhodamine B (1 mg / mL) and stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 60°C for 1 h to obtain an amorphous film M11.

[0069] Example 12: Preparation of delayed fluorescence and organic room temperature phosphorescent material M12 (TPA-2Py@BR20%@PVA).

[0070] Weigh 1.50 g of PVA and dissolve it in 50 mL of water. Take 2.33 mL of the solution and add TPA-Py (1 mg). Then add 200 μL of an aqueous solution of rhodamine B (1 mg / mL) and stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 60°C for 1 h to obtain an amorphous film M12.

[0071] Example 13: Preparation of delayed fluorescence and organic room temperature phosphorescent material M13 (TPA-2Py@BR25%@PVA).

[0072] Weigh 1.50 g of PVA and dissolve it in 50 mL of water. Take 2.33 mL of the solution and add TPA-Py (1 mg). Then add 200 μL of an aqueous solution of rhodamine B (1 mg / mL) and stir vigorously overnight. The next day, take 20 μL of the mixed solution and drop it onto a quartz plate. Volatilize the water in a drying oven and anneal at 60°C for 1 h to obtain an amorphous film M13.

[0073] Figure 9 The time-resolved phosphorescence emission decay curves of amorphous thin film materials M1-M3 are 703.6ms, 798.4ms, and 564.0ms, respectively, according to exponential fitting.

[0074] Figure 11 The time-resolved phosphorescence emission decay curves of amorphous thin film materials M5-M7 after photoactivation are 287ms, 209ms, 88ms, and 429ms, respectively, according to exponential fitting.

[0075] Figure 12 The time-resolved fluorescence emission decay curves of amorphous thin film materials M8-M13 for rhodamine B were obtained by transferring the triplet energy of TPA-2Py to rhodamine B. The decay curves were 542.2 ms, 322.5 ms, 201.6 ms, 154.4 ms, 111.2 ms, and 86.3 ms, respectively, according to exponential fitting.

[0076] Figure 14 When the M2 material is fumigated with hydrochloric acid, TPA-2Py is protonated and loses the property of room temperature phosphorescence; or when fumigated with water vapor, the hydrogen bond is destroyed and the property of room temperature phosphorescence is lost, but room temperature phosphorescence can be obtained by heating and annealing again.

[0077] Figure 15 This is the delayed fluorescence image obtained by doping M2 material with different contents of Rhodamine B. As the content of Rhodamine B increases, the delayed fluorescence lifetime gradually decreases.

[0078] Figure 16 The mouse and the cheese in its hand are made of amorphous thin film materials M2 and M11 respectively. After turning off the UV light, the mouse is shown holding the cheese with a luminous afterglow. After about 2 seconds, the cheese in the mouse's hand disappears, leaving only the phosphorescence displayed by the mouse itself.

[0079] Figure 17 The encrypted message reads "AUORTP." "A" represents the non-phosphorescent film material, "U" represents material M13, "O" represents material M9, and "RTP" represents material M2. All of these materials fluoresce under ultraviolet light. The moment the UV light is turned off, "A" ceases to glow. About 1.5 seconds later, "U" ceases to glow. After about 3 seconds, only "RTP," made of material M2, remains luminescent. The message "RTP" is revealed by this time-dependent change.

[0080] Figure 18 It is a photoactivated image of amorphous thin film materials M4, M5 and M6. No phosphorescence will be displayed without continuous UV light irradiation. When sufficient UV light irradiation is obtained and the UV lamp is turned off, room temperature phosphorescence caused by photoactivation can be obtained.

[0081] In summary, the present invention presents a pyridine-based triphenylamine derivative-doped thin-film room-temperature phosphorescent material that can be obtained through physical blending and annealing, demonstrating ease of operation and broad applicability. This invention provides a simple, universal design principle that is beneficial for the development of novel non-covalently interacting amorphous room-temperature phosphorescent materials, further promoting their applications in electroluminescent devices, chemical sensing, bioimaging, data encryption, and anti-counterfeiting marking.

[0082] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative, characterized in that: include: dispersing polymethyl methacrylate in a solvent to obtain a polymethyl methacrylate solution; dispersing a triphenylamine derivative containing a pyridine group in the polymethyl methacrylate solution to obtain a mixed solution; annealing the mixed solution to obtain the room temperature phosphorescent material based on the pyridine-substituted triphenylamine derivative; The mass ratio of the polymethyl methacrylate to the triphenylamine derivative containing a pyridine group is (100:1)-(10:1).

2. The method for preparing a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative according to claim 1, characterized in that: The triphenylamine derivative containing a pyridine group is selected from One or more of .

3. The method for preparing a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative according to claim 1, characterized in that: The annealing temperature is 60-80°C.

4. The method for preparing a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative according to claim 1, wherein: The polymethyl methacrylate is dispersed in an organic solvent to obtain a polymethyl methacrylate solution.

5. The method for preparing a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative according to claim 3, characterized in that: The annealing time is 50-75 minutes.

6. A room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative, characterized in that: The room temperature phosphorescent material is prepared by the preparation method of any one of claims 1 to 5 based on a pyridine-substituted triphenylamine derivative.

7. An application of a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative, characterized in that: The room temperature phosphorescent material based on the pyridine-substituted triphenylamine derivative according to claim 6 is used to prepare an organic light-emitting device.

8. An application of a room temperature phosphorescent material based on a pyridine-substituted triphenylamine derivative, characterized in that: The room temperature phosphorescent material based on the pyridine-substituted triphenylamine derivative according to claim 6 is used for anti-counterfeiting marking.

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