Pyrene compound and organic electroluminescent device

Abstract

The application provides a pyrene compound and an organic electroluminescent device. The pyrene compound is obtained by designing the structure of the pyrene compound, and the pyrene compound can be used as a host material of a light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has a lower driving voltage, a higher current efficiency and a longer service life.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescent materials technology, specifically relating to a pyrene compound and an organic electroluminescent device. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are devices fabricated by depositing one or more layers of organic material between two metal electrodes via spin coating or vacuum evaporation. A classic three-layer OLED comprises a hole transport layer, an emissive layer, and an electron transport layer. Holes generated by the anode combine with electrons generated by the cathode via the electron transport layer in the emissive layer to form excitons, which then emit light. OLEDs can be tuned to emit various desired light colors by changing the material of the emissive layer.

[0003] Organic electroluminescent devices, as a novel display technology, possess unique advantages such as self-illumination, wide viewing angle, low energy consumption, high efficiency, thinness, rich colors, fast response speed, wide applicable temperature range, low driving voltage, the ability to manufacture flexible, bendable, and transparent display panels, and environmental friendliness. They can be applied to flat panel displays and next-generation lighting, and can also serve as backlights for LCDs.

[0004] Since their invention in the late 1980s, organic light-emitting diodes (OLEDs) have been used in various industries, such as as screens in cameras and mobile phones. However, current OLED devices suffer from low efficiency and short lifespan, limiting their wider application, especially in large-screen displays. Therefore, it is necessary to improve device performance. A key factor limiting OLED device performance is the performance of the organic light-emitting materials used in the OLED. Thus, it is essential to develop stable and efficient organic light-emitting materials to improve the current efficiency and lifespan of OLED devices. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a pyrene-based compound and an organic electroluminescent device. By designing the structure of a pyrene-based compound, the present invention allows this compound to be used as the main material for the light-emitting layer of an organic electroluminescent device, resulting in an organic electroluminescent device with lower driving voltage, higher current efficiency, and longer lifespan.

[0006] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a pyrene compound having the structure shown in Formula I: Formula I; Ar1 is selected from hydrogen atoms or C6-C40 aryl groups; when Ar1 is selected from C6-C40 aryl groups, Ar1 and the benzene ring to which it is attached can be connected by -O-, Bridged into a quintuple, with dashed lines indicating connection points; R 01 R 02 Each is independently selected from any one of C1-C12 straight-chain or branched alkyl groups and C3-C12 cycloalkyl groups; In compounds of Formula I, each hydrogen atom can be independently replaced by at least one of deuterium, -F, cyano (-CN), C1-C12 straight-chain or branched alkyl, C3-C12 cycloalkyl, C1-C12 straight-chain or branched alkoxy, or C3-C12 cycloalkoxy.

[0007] This invention designs the structure of pyrene compounds, which can be used as the main material for the light-emitting layer of organic electroluminescent devices, resulting in organic electroluminescent devices with lower driving voltage, higher current efficiency, and longer lifespan.

[0008] In this invention, "D" represents a deuterium atom, and the same applies below.

[0009] In this invention, C6-C40 can be C6, C8, C10, C12, C13, C15, C18, C20, C24, C28, C30, C36 or C40, etc.

[0010] C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12.

[0011] C3-C12 can be C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12.

[0012] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0013] Preferably, the C1-C12 straight-chain or branched alkyl group is selected from any one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, undecyl, and dodecyl.

[0014] Preferably, the C3-C12 cycloalkyl group is selected from any one of cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0015] Preferably, the C1-C12 straight-chain or branched alkoxy group is selected from any one of methoxy, ethoxy, n-propoxy, isopropoxy, n-pentoxy, and n-hexoxy.

[0016] Preferably, the C3-C12 cycloalkoxy group is selected from any one of cyclopropoxy, cyclobutoxy, cyclopentoxy, and cyclohexyloxy.

[0017] Preferably, the C6-C40 aryl group is selected from at least one of phenyl, biphenyl, terphenyl, naphthyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, triphenylene, pyrene, anthracene, phenanthrene, fluoranthyl, and triphenylene.

[0018] Preferably, the Ar1 is selected from any one of hydrogen atom, phenyl, biphenyl, terphenyl, naphthyl, 9,9-dimethylfluorenyl, triphenylene, and pyrene, and more preferably any one of hydrogen atom, phenyl, biphenyl, terphenyl, and naphthyl.

[0019] Preferably, the R 01 R 02 Each is independently selected from any one of methyl, ethyl, or [methyl group].

[0020] Preferably, each hydrogen atom in the compound of Formula I can be independently replaced by at least one of deuterium, -F, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, n-propoxy, and isopropoxy.

[0021] Preferably, the pyrene compound has the structure shown in Formula I-1, Formula I-2 or Formula I-3: ; Ar1 has the same definition as above; the hydrogen atom in compounds of formula I-1, I-2, and I-3 can each be independently replaced by at least one of deuterium, -F, cyano (-CN), C1-C12 straight-chain or branched alkyl, C3-C12 cycloalkyl, C1-C12 straight-chain or branched alkoxy, and C3-C12 cycloalkoxy.

[0022] Preferably, the pyrene compound is selected from any one of the following substituted or unsubstituted compounds: ; The substitution refers to the replacement of at least one hydrogen atom in the above compound with a deuterium atom.

[0023] Preferably, the pyrene compound is selected from any one of the following substituted or unsubstituted compounds 1 to 11: , , , , , , , , , , ; The substitution refers to the replacement of at least one hydrogen atom in compounds 1 to 11 by a deuterium atom.

[0024] It should be noted that the present invention does not impose any special restrictions on the synthesis method of the pyrene compounds shown in Formula I, and commonly used synthesis methods in the art are applicable.

[0025] Thirdly, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode, the organic thin film layer comprising pyrene compounds as described in the first aspect.

[0026] Preferably, the organic thin film layer includes a light-emitting layer, which includes a pyrene compound as described in the first aspect.

[0027] Preferably, the light-emitting layer comprises a host material and a dopant material, wherein the host material comprises a pyrene compound as described in the first aspect.

[0028] Preferably, the doped material comprises at least one of a compound having the structure shown in Formula II and a compound having the structure shown in Formula III: Formula II; Formula III; Among them, Ar 21 Ar 22 Each is independently selected from any one of substituted or unsubstituted C6-C20 (e.g., C6, C8, C10, C12, C13, C15, C18, or C20) aryl groups, or substituted or unsubstituted C3-C20 (e.g., C3, C4, C5, C8, C9, C12, C15, C18, or C20) heteroaryl groups; R 21 R 22 and R 23Each is independently selected from hydrogen, C1-C12 (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, or C12) straight-chain or branched alkyl groups, and C3-C12 (e.g., C3, C4, C5, C6, C7, C8, C9, C10, C11, or C12) cycloalkyl groups; Ar 21 Ar 22 The substituents described herein are each independently selected from any one of C1-C5 (e.g., C1, C2, C3, C4, or C5) straight-chain or branched alkyl groups, and C6-C12 (e.g., C6, C10, or C12, etc.) aryl groups; Ar 31 Ar 32 Ar 33 and Ar 34 Each is independently selected from any one of substituted or unsubstituted C6-C22 (e.g., C6, C8, C9, C12, C15, C18, C20, or C22, etc.) aryl, or substituted or unsubstituted C12-C40 (e.g., C12, C13, C15, C18, C20, C24, C30, C36, or C40, etc.) heteroaryl; R 31 Selected from any one of phenyl, naphthyl, or biphenyl; a is selected from 0 or 1; Ar 31 Ar 32 Ar 33 Ar 34 The substituents described herein are each independently selected from C1-C5 straight-chain or branched alkyl groups or C6-C12 aryl groups.

[0029] Preferably, in formula II, the Ar 21 Ar 22 Each independently selected , , , , , , , , , , , , , , , , Any of the following, with dashed lines representing connection points.

[0030] Preferably, in formula II, R 21 R 22 and R 23Each is independently selected from any one of hydrogen, methyl, ethyl, propyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclohexyl, or adamantyl.

[0031] Preferably, in formula III, the Ar 31 Ar 32 Ar 33 and Ar 34 Each independently selected , , , , , , , , , Any one or at least two of the above, with dashed lines indicating connection sites.

[0032] Preferably, the compound having the structure shown in Formula II is selected from any one of the following compounds: .

[0033] Preferably, the compound having the structure shown in Formula III is selected from any one of the following compounds: .

[0034] Preferably, the volume percentage of the main material in the light-emitting layer is 60%-99.9% (e.g., it can be 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99.9%), more preferably 70%-99.5%, and even more preferably 85%-95%.

[0035] Preferably, the organic thin film layer further includes one or a combination of several of the following: a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. In this invention, no special limitations are placed on the materials used for the hole injection layer, hole transport layer, electron transport layer, and electron injection layer; any materials known in the art capable of hole injection, hole transport, electron transport, and electron injection can be used.

[0036] Thirdly, the present invention provides a display device comprising the organic electroluminescent device as described in the second aspect.

[0037] Compared with the prior art, the present invention has the following beneficial effects: This invention designs the structure of compounds to obtain pyrene compounds as the main material for the light-emitting layer of organic electroluminescent devices, thereby enabling the organic electroluminescent devices to have lower driving voltage, higher current efficiency and longer lifespan. Detailed Implementation

[0038] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0039] Preparation Example 1 This preparation example provides intermediate 10-1 and its synthesis method, which is as follows: In a nitrogen atmosphere, 180 mL of toluene, 60 mL of ethanol, and 15 mL of water were added sequentially to a three-necked flask. Then, 3.3 g of 3,5-dibromo-1,1'-biphenyl, 2.5 g of pyrene-2-boric acid, 2.12 g of sodium carbonate, and 0.23 g of tetrakis(triphenylphosphine)palladium were added. The mixture was slowly heated to reflux and reacted for 6 hours. After cooling to room temperature, water was added to liquidate the mixture. The organic layer was washed with water and dried with magnesium sulfate. After removing the desiccant, the mixture was concentrated to dryness and separated by silica gel column chromatography. The eluent was obtained by elution with a mixture of petroleum ether and ethyl acetate in a volume ratio of 10:1, yielding 2.2 g of intermediate 10⁻¹. The obtained intermediate 10-1 was subjected to mass spectrometry analysis, and the mass-to-charge ratio (m / z) was measured to be 432.05.

[0040] Preparation Example 2 This preparation example provides intermediate 11-1 and its synthesis method, which is as follows: Intermediate 11-1 was prepared by referring to the synthesis method provided in Preparation Example 1.

[0041] The obtained intermediate 11-1 was subjected to mass spectrometry analysis, and the mass-to-charge ratio (m / z) was measured to be 432.05.

[0042] Example 1 This embodiment provides compound 1 and its synthesis method, which is as follows: Compound 1 was prepared by referring to the synthetic method of intermediate 10-1 provided in Preparation Example 1.

[0043] The obtained compound 1 was subjected to mass spectrometry, and the mass-to-charge ratio (m / z) was measured to be 606.23.

[0044] Examples 2-11 Examples 2-11 provide a pyrene compound and its synthesis method. The synthesis method of the pyrene compound is the same as the synthesis method of compound 1 provided in Example 1. The mass spectra of the prepared pyrene compounds were tested, as detailed in Table 1 below.

[0045] Table 1 Other compounds for which specific synthetic steps are not listed can be prepared using common knowledge in the field, combined with the above synthetic examples.

[0046] The specific structures of the compounds used in the following application examples and comparative application examples are shown below: , , , , , , , , , , , , , , , , , , , .

[0047] Application Example 1 This application example provides an organic electroluminescent device with the following structure: ITO / HTL (80nm) / BH:BD-2 (5%) (30nm) / TPBI (30nm) / Al (150nm); The fabrication method of the above-mentioned organic electroluminescent device is as follows: Each layer of material was placed inside a vacuum chamber, and the vacuum was evacuated to 1×10⁻⁶. -5 ~1×10 -6 Pa is sequentially vacuum-deposited onto the cleaned ITO substrate; HTL (80nm) refers to the hole transport layer, which has a thickness of 80nm. BH:BD-2 (5%) (30nm) refers to the emitting layer, BH refers to the blue light host material, BD-2 is the dopant material, BH:BD-2 (5%) (30nm) means that the volume ratio of BH to the dopant material BD-2 in the emitting layer is 95:5, and the film thickness of the emitting layer is 30nm; in this application example, the BH material is compound 1; TPBI (30nm) refers to the electron transport layer, and the film thickness is 30nm; ITO refers to the anode, and Al (150nm) refers to the cathode.

[0048] Application Examples 2-4 Application Examples 2-4 each provide an organic electroluminescent device, differing from Application Example 1 only in the use of a different BH material (as shown in Table 2 below), while the other preparation steps are the same as in Application Example 1.

[0049] Comparative Application Examples 1-3 Comparative Application Examples 1-3 each provide an organic electroluminescent device. The only difference between them and Application Example 1 is the BH material (as shown in Table 2 below). The other preparation steps are the same as in Application Example 1.

[0050] The organic electroluminescent devices underwent performance testing, including tests on brightness, driving voltage, current efficiency, and LT80. LT80 refers to maintaining an initial brightness of 1000 cd / m². 2 With the current density remaining constant, the device efficiency drops to the initial luminance of 1000 cd / m². 2 The time required to achieve 80% of the corresponding efficiency. Among them, the drive voltage, current efficiency, and LT80 are all relative values ​​(based on Comparative Application Example 1).

[0051] The specific test results are shown in Table 2 below: Table 2 As can be seen from the above, by designing the structure of pyrene compounds, the present invention provides pyrene compounds that can be used as the main material for the light-emitting layer of organic electroluminescent devices, thereby enabling organic electroluminescent devices to have lower driving voltage, higher current efficiency, and longer lifespan.

[0052] Application Examples 5-7 Application Examples 5-7 each provide an organic electroluminescent device, which differs from Application Example 1 only in that the BH material is different (as shown in Table 3 below), while the other preparation steps are the same as in Application Example 1.

[0053] The organic electroluminescent devices underwent performance testing, including tests on brightness, driving voltage, current efficiency, and LT80. LT80 refers to maintaining an initial brightness of 1000 cd / m².2 With the current density remaining constant, the device efficiency drops to the initial luminance of 1000 cd / m². 2 The time required to achieve 80% of the corresponding efficiency. Among them, the drive voltage, current efficiency, and LT80 are all relative values ​​(based on Application Example 5).

[0054] The specific test results are shown in Table 3 below: Table 3 Application Examples 8-10 Application Examples 8-10 each provide an organic electroluminescent device. The only difference from Application Example 1 is that the BH material is different (as shown in Table 4 below), and BD-2 is replaced with BD-3. The other preparation steps are the same as in Application Example 1.

[0055] Performance testing was conducted on organic electroluminescent devices, including tests for luminance, driving voltage, current efficiency, and LT80; where LT80 refers to maintaining an initial luminance of 1000 cd / m². 2 With the current density remaining constant, the device efficiency drops to the initial luminance of 1000 cd / m². 2 The time required to achieve 80% of the corresponding efficiency. Among them, the drive voltage, current efficiency, and LT80 are all relative values ​​(based on Application Example 8).

[0056] The specific test results are shown in Table 4 below: Table 4 Application Examples 11-12 Application Examples 11-12 each provide an organic electroluminescent device. The only difference from Application Example 1 is that the BH material is different (as shown in Table 5 below), and BD-2 is replaced with BD-1. The other preparation steps are the same as in Application Example 1.

[0057] Performance testing was conducted on organic electroluminescent devices, including tests for luminance, driving voltage, current efficiency, and LT80; where LT80 refers to maintaining an initial luminance of 1000 cd / m². 2 With the current density remaining constant, the device efficiency drops to the initial luminance of 1000 cd / m². 2 The time required to achieve 80% of the corresponding efficiency. The drive voltage, current efficiency, and LT80 are all relative values ​​(based on Application Example 11).

[0058] The specific test results are shown in Table 5 below: Table 5 In summary, by designing the structure of pyrene compounds, this invention provides pyrene compounds as the main material for the light-emitting layer of organic electroluminescent devices, resulting in organic electroluminescent devices with lower driving voltage, higher current efficiency, and longer lifespan.

[0059] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A pyrene compound, characterized in that, The pyrene compounds have the structure shown in Formula I: Equation I; Ar1 is selected from hydrogen atoms or C6-C40 aryl groups; When Ar1 is selected from C6-C40 aryl groups, Ar1 and the benzene ring attached to it can be connected by -O-, Bridged into a quintuple, with dashed lines indicating connection points; R 01 R 02 Each is independently selected from any one of C1-C12 straight-chain or branched alkyl groups and C3-C12 cycloalkyl groups; In compounds of Formula I, each hydrogen atom can be independently replaced by at least one of deuterium, -F, cyano, C1-C12 straight-chain or branched alkyl, C3-C12 cycloalkyl, C1-C12 straight-chain or branched alkoxy, or C3-C12 cycloalkoxy.

2. The pyrene compound according to claim 1, characterized in that, The C1-C12 straight-chain or branched alkyl group is selected from any one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, undecyl, and dodecyl. Preferably, the C3-C12 cycloalkyl group is selected from any one of cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; Preferably, the C1-C12 straight-chain or branched alkoxy group is selected from any one of methoxy, ethoxy, n-propoxy, isopropoxy, n-pentoxy, and n-hexoxy. Preferably, the C3-C12 cycloalkoxy group is selected from any one of cyclopropoxy, cyclobutoxy, cyclopentoxy, and cyclohexyloxy. Preferably, the C6-C40 aryl group is selected from at least one of phenyl, biphenyl, terphenyl, naphthyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, triphenylene, pyrene, anthracene, phenanthrene, fluoranthyl, and triphenylene.

3. The pyrene compound according to claim 1 or 2, characterized in that, The Ar1 is selected from any one of hydrogen atom, phenyl, biphenyl, terphenyl, naphthyl, 9,9-dimethylfluorenyl, triphenylene, and pyrene, and is more preferably any one of hydrogen atom, phenyl, biphenyl, terphenyl, and naphthyl; Preferably, the R 01 R 02 Each is independently selected from any one of methyl, ethyl, and [other compounds]. Preferably, each hydrogen atom in the compound of Formula I can be independently replaced by at least one of deuterium, -F, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, n-propoxy, and isopropoxy.

4. The pyrene compound according to any one of claims 1-3, characterized in that, The pyrene compounds have the structures shown in Formula I-1, Formula I-2 or Formula I-3 as follows: ； Ar1 has the same definition as in claim 1; In compounds of formula I-1, I-2, and I-3, the hydrogen atom can be independently replaced by at least one of the following: deuterium atom, -F, cyano group, C1-C12 straight-chain or branched alkyl group, C3-C12 cycloalkyl group, C1-C12 straight-chain or branched alkoxy group, and C3-C12 cycloalkoxy group.

5. The pyrene compound according to any one of claims 1-4, characterized in that, The pyrene compounds are selected from any one of the following substituted or unsubstituted compounds: ； The substitution refers to the replacement of at least one hydrogen atom in the above compound with a deuterium atom; Preferably, the pyrene compound is selected from any one of the following substituted or unsubstituted compounds 1 to 11: 、 、 、 、 、 、 、 、 、 、 ； The substitution refers to the replacement of at least one hydrogen atom in compounds 1 to 11 by a deuterium atom.

6. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode, wherein the organic thin film layer includes a pyrene compound as described in any one of claims 1-5.

7. The organic electroluminescent device according to claim 6, characterized in that, The organic thin film layer includes a light-emitting layer, which includes the pyrene compound as described in any one of claims 1-5; Preferably, the light-emitting layer comprises a host material and a dopant material, wherein the host material comprises a pyrene compound as described in any one of claims 1-5; Preferably, the doped material comprises at least one of a compound having the structure shown in Formula II and a compound having the structure shown in Formula III: Formula II; Formula III; Among them, Ar 21 Ar 22 Each is independently selected from any one of substituted or unsubstituted C6-C20 aryl groups or substituted or unsubstituted C3-C20 heteroaryl groups; R 21 R 22 and R 23 Each is independently selected from any one of hydrogen, C1-C12 straight-chain or branched alkyl, and C3-C12 cycloalkyl; Ar 21 Ar 22 The substituents described herein are each independently selected from any one of C1-C5 straight-chain or branched alkyl groups and C6-C12 aryl groups; Ar 31 Ar 32 Ar 33 and Ar 34 Each is independently selected from any one of substituted or unsubstituted C6-C22 aryl groups or substituted or unsubstituted C12-C40 heteroaryl groups; R 31 Selected from any one of phenyl, naphthyl, or biphenyl; a is selected from 0 or 1; Ar 31 Ar 32 Ar 33 Ar 34 The substituents described herein are each independently selected from C1-C5 straight-chain or branched alkyl groups or C6-C12 aryl groups.

8. The organic electroluminescent device according to claim 7, characterized in that, In Formula II, the Ar 21 Ar 22 Each independently selected , , , , , , , , , , , , , , , , Any of the following, with dashed lines representing connection points; Preferably, in formula II, R 21 R 22 and R 23 Each is independently selected from any one of hydrogen, methyl, ethyl, propyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclohexyl, or adamantyl; Preferably, in formula III, the Ar 31 Ar 32 Ar 33 and Ar 34 Each independently selected , , , , , , , , , Any one or at least two of the above, with dashed lines indicating connection sites.

9. The organic electroluminescent device according to claim 7 or 8, characterized in that, The compound having the structure shown in Formula II is selected from any one of the following compounds: ； Preferably, the compound having the structure shown in Formula III is selected from any one of the following compounds: 。 10. The organic electroluminescent device according to any one of claims 7-9, characterized in that, The volume percentage of the main material in the light-emitting layer is 60%-99.9%, preferably 70%-99.5%, and more preferably 85%-95%.

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