An organic compound taking benzene as a core, a preparation method and application thereof, and an organic electroluminescent device

Abstract

The application provides an organic compound with benzene as a core and a preparation method and application thereof, and an organic electroluminescent device, and belongs to the technical field of semiconductors. The organic compound provided by the application has benzene as a core and is connected with an electron-donating group, has high hole mobility, and has high hole transport rate, which can effectively reduce the starting voltage of the device and improve the efficiency of the organic electroluminescent device. The triamine structure in the compound can reduce the crystallinity of the molecule, reduce the planarity of the molecule, prevent the molecule from moving on the plane, and thus improve the thermal stability of the molecule. Meanwhile, the structure of the compound provided by the application makes the distribution of electrons and holes in the light-emitting layer more balanced, improves the hole injection and transport performance under the appropriate HOMO energy level, and can improve the current efficiency and service life of the device.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to an organic compound with pyromellitic ether as its core, its preparation method and application, and an organic electroluminescent device. Background Technology

[0002] Organic light-emitting diode (OLED) technology can be used to manufacture novel display products and lighting products, and it holds promise as a replacement for existing liquid crystal displays and fluorescent lighting, with a wide range of applications. OLEDs have a sandwich-like structure, consisting of electrode material layers and organic functional materials sandwiched between them. These various functional materials are stacked together according to their intended use to form the OLED. As a current-carrying device, when a voltage is applied to the two electrodes of the OLED, and an electric field is applied to the positive and negative charges in the organic functional material layers, these charges recombine in the light-emitting layer, thus generating organic light emission.

[0003] Organic optoelectronic functional material films constituting organic electroluminescent devices consist of at least two layers. Industrially applied organic electroluminescent device structures include multiple layers such as hole injection layers, hole transport layers, electron blocking layers, luminescent layers, hole blocking layers, electron transport layers, and electron injection layers. In other words, the optoelectronic functional materials used in organic electroluminescent devices include at least hole injection materials, hole transport materials, luminescent materials, and electron transport materials, exhibiting richness and diversity in material types and combinations. Furthermore, the optoelectronic functional materials used in combination with different organic electroluminescent device structures exhibit strong selectivity; the same material may perform drastically differently in devices with different structures.

[0004] Therefore, in order to meet the current industrial application requirements of OLED devices and the photoelectric characteristics requirements of different functional film layers of organic electroluminescent devices, it is necessary to select high-performance organic electroluminescent functional materials to achieve the comprehensive characteristics of high efficiency, long lifespan and low voltage of the devices. Summary of the Invention

[0005] In view of this, the present invention aims to provide an organic compound with pyromellitic styrene as its core, its preparation method and application, and an organic electroluminescent device. The organic compound with pyromellitic styrene as its core provided by the present invention can effectively improve the current efficiency and lifespan of OLED devices.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides an organic compound with pyromellitic ether as its core, having the structure shown in formula (1):

[0008]

[0009] In equation (1), Ar1, Ar2, Ar3, and Ar4 are each independently substituted or unsubstituted C6-C. 30 aryl, substituted or unsubstituted C5-C containing one or more heteroatoms 30 Mixed aromatics;

[0010] X1 is an oxygen atom or a sulfur atom;

[0011] X2 is an oxygen atom or a sulfur atom;

[0012] Among the above-mentioned substituted groups, each substituent is independently a deuterium atom, alkoxy group, cyano group, halogen atom, or C1-C group. 20 Alkyl, C3-C 20 cycloalkyl, C6-C 30 One or more of aryl and heteroaryl containing one or more heteroatoms;

[0013] The heteroatom is one or more of oxygen, sulfur, or nitrogen atoms.

[0014] Preferably, it has the structure shown in any one of equations (2-1) to (2-2):

[0015]

[0016] Preferably, it has the structure shown in formula (3-1):

[0017]

[0018] Preferably, it has the structure shown in any one of equations (4-1) to (4-2):

[0019]

[0020] Preferably, it has the structure shown in any one of equations (5-1) to (5-2):

[0021]

[0022] Preferably, Ar1, Ar2, Ar3, and Ar4 are each independently substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted dimethylfluorenyl, substituted or unsubstituted carbazole, or substituted or unsubstituted pyridyl.

[0023] In the above-mentioned substituted groups, each substituent is independently one or more of the following: fluorine atom, methoxy, cyano, methyl, ethyl, propyl, adamantyl, isopropyl, tert-butyl, pentyl, phenyl, naphthyl, diphenyl, naphthidyl, or pyridyl.

[0024] This invention provides a method for preparing the above-mentioned organic compound with pyromellitic ether as the core, comprising the following steps:

[0025] A compound having the structure shown in formula a, a compound having the structure shown in formula b, and a compound having the structure shown in formula c undergo a first substitution reaction to obtain a compound having the structure shown in formula d.

[0026]

[0027] A compound having the structure shown in formula d undergoes a second substitution reaction with a compound having the structure shown in formula e to obtain an organic compound with pyromellitic core having the structure shown in formula (1).

[0028]

[0029] This invention provides the application of the above-mentioned organic compounds with pyromellitic ether as the core in the preparation of organic electroluminescent devices.

[0030] The present invention provides an organic electroluminescent device, comprising a cathode, an anode, and an organic functional layer, wherein the organic functional layer is located between the anode and the cathode, and the organic functional layer comprises the aforementioned organic compound with pyromellitic as the core.

[0031] Preferably, the organic functional layer includes a hole transport region, a light-emitting region, and an electron transport region, wherein the hole transport region includes the aforementioned organic compound with pyromellitic tin oxide as its core.

[0032] This invention provides an organic compound with pyromellitic ether as its core, having the structure shown in formula (1). The organic compound provided by this invention, with pyromellitic ether as its core and connected to electron-donating groups, exhibits high hole mobility. This high hole transport rate effectively reduces the onset voltage of the device and improves the efficiency of the organic electroluminescent device. Furthermore, the triamine structure reduces the crystallinity and planarity of the molecule, preventing it from moving on the plane and thus improving its thermal stability. Simultaneously, the structure of the compound provided by this invention allows for a more balanced distribution of electrons and holes in the light-emitting layer, enhancing hole injection and transport performance at appropriate HOMO energy levels, thereby improving the current efficiency and lifetime of the device. The results of the embodiments show that the organic electroluminescent device obtained using the pyromellitic ether as its core material has a current efficiency of 140.3–158.6 and a lifetime of 362.8–384.2 h.

[0033] This invention provides a method for preparing the above-mentioned organic compound with pyromellitic ether as the core. This method is simple to operate and suitable for industrial mass production.

[0034] This invention provides an organic electroluminescent device, comprising a cathode, an anode, and an organic functional layer, wherein the organic functional layer is located between the anode and the cathode, and the organic functional layer comprises the aforementioned organic compound with pyromellitic styrene as its core. The organic electroluminescent device provided by this invention exhibits good device efficiency and lifetime. Attached Figure Description

[0035] Figure 1 This is a schematic cross-sectional view of the organic electroluminescent device of the present invention. Detailed Implementation

[0036] This invention provides an organic compound with pyromellitic ether as its core, having the structure shown in formula (1):

[0037]

[0038] In equation (1), Ar1, Ar2, Ar3, and Ar4 are each independently substituted or unsubstituted C6-C. 30 aryl, substituted or unsubstituted C5-C containing one or more heteroatoms 30 Mixed aromatics;

[0039] X1 is an oxygen atom or a sulfur atom;

[0040] X2 is an oxygen atom or a sulfur atom;

[0041] Among the above-mentioned substituted groups, each substituent is independently a deuterium atom, alkoxy group, cyano group, halogen atom, or C1-C group. 20 Alkyl, C3-C 20 cycloalkyl, C6-C 30 One or more of aryl and heteroaryl containing one or more heteroatoms;

[0042] The heteroatom is one or more of oxygen, sulfur, or nitrogen atoms.

[0043] In this invention, This represents any connectable site that can be attached to an adjacent benzene ring.

[0044] In this invention, Ar1, Ar2, Ar3, and Ar4 are each preferably substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted dimethylfluorenyl, substituted or unsubstituted carbazole, or substituted or unsubstituted pyridyl.

[0045] In this invention, the substituents are preferably one or more selected from the following groups: fluorine atom, methoxy, cyano, methyl, ethyl, propyl, adamantyl, isopropyl, tert-butyl, pentyl, phenyl, naphthyl, diphenyl, naphthidyl, or pyridyl.

[0046] In this invention, the organic compound with benzene as its core preferably has the structure shown in any one of formulas (2-1) to (2-2):

[0047]

[0048]

[0049] In this invention, the organic compound with benzene as its core preferably has the structure shown in formula (3-1):

[0050]

[0051] In this invention, the organic compound with benzene as its core preferably has the structure shown in any one of formulas (4-1) to (4-2):

[0052]

[0053] In this invention, the organic compound with benzene as its core preferably has the structure shown in any one of formulas (5-1) to (5-2):

[0054]

[0055] In this invention, the organic compound with benzene as its core preferably has the structure shown in any one of formulas 1 to 18:

[0056]

[0057]

[0058] This invention provides a method for preparing the above-mentioned organic compound with pyromellitic ether as the core, comprising the following steps:

[0059] A compound having the structure shown in formula a, a compound having the structure shown in formula b, and a compound having the structure shown in formula c undergo a first substitution reaction to obtain a compound having the structure shown in formula d.

[0060]

[0061]

[0062] A compound having the structure shown in formula d undergoes a second substitution reaction with a compound having the structure shown in formula e to obtain an organic compound with pyromellitic core having the structure shown in formula (1).

[0063]

[0064] In this invention, a compound having the structure shown in formula a, a compound having the structure shown in formula b, and a compound having the structure shown in formula c undergo a first substitution reaction to obtain a compound having the structure shown in formula d. In this invention, the molar ratio of the compound having the structure shown in formula a, the compound having the structure shown in formula b, and the compound having the structure shown in formula c is preferably 1:1:1.

[0065] In this invention, the first substitution reaction is preferably carried out in the presence of a catalyst, preferably Pd2(dba)3 and triphenylphosphine, wherein the molar ratio of Pd2(dba)3 to triphenylphosphine is preferably 1:1.

[0066] In this invention, the first substitution reaction is preferably carried out in the presence of potassium tert-butoxide, and the molar ratio of the compound having the structure shown in Formula a to potassium tert-butoxide is preferably 1:5.

[0067] In this invention, the solvent used for the first substitution reaction is preferably toluene. In this invention, the temperature of the first substitution reaction is preferably reflux temperature, and the reaction time is preferably 18 hours.

[0068] Following the first substitution reaction, the present invention preferably performs post-treatment on the obtained first substitution reaction solution, the post-treatment preferably including the following steps:

[0069] The first substitution reaction solution was filtered, the filtrate was rotary evaporated, and passed through a silica gel column to obtain a pure compound with the structure shown in formula d.

[0070] In this invention, a compound having the structure shown in formula d undergoes a second substitution reaction with a compound having the structure shown in formula e to obtain an organic compound with a pyromellitic core having the structure shown in formula (1). In this invention, the preferred molar ratio of the compound having the structure shown in formula d to the compound having the structure shown in formula e is 1:1.2.

[0071] In this invention, the second substitution reaction is preferably carried out in the presence of a catalyst, preferably Pd2(dba)3 and triphenylphosphine, wherein the molar ratio of Pd2(dba)3 to triphenylphosphine is preferably 1:1.

[0072] In this invention, the substitution reaction is preferably carried out in the presence of potassium tert-butoxide, and the molar ratio of the compound having the structure shown in formula d to potassium tert-butoxide is preferably 1:3.

[0073] In this invention, the solvent used for the second substitution reaction is preferably toluene. In this invention, the temperature of the second substitution reaction is preferably reflux temperature, and the time is preferably 20 hours.

[0074] Following the second substitution reaction, the present invention preferably performs post-treatment on the obtained second substitution reaction solution, the post-treatment preferably including the following steps:

[0075] The second substitution reaction solution was filtered, the filtrate was rotary evaporated, and passed through a silica gel column to obtain an organic compound with the structure shown in formula (1) as the core of pyromellitic ether.

[0076] This invention provides the application of the above-mentioned organic compounds with pyromellitic ether as the core in the preparation of organic electroluminescent devices.

[0077] The present invention provides an organic electroluminescent device, comprising a cathode, an anode, and an organic functional layer, wherein the organic functional layer is located between the anode and the cathode, and the organic functional layer comprises the aforementioned organic compound with pyromellitic as the core.

[0078] In this invention, the organic functional layer preferably includes a hole transport region, a light-emitting region, and an electron transport region, wherein the hole transport region includes the aforementioned organic compound with pyromellitic benzoylene as its core.

[0079] In this invention, the hole transport region preferably includes a hole transport layer and / or an electron blocking layer, wherein the hole transport layer contains the aforementioned organic compound with pyromellitic benzoylene as its core.

[0080] In this invention, the organic functional layer preferably comprises a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, an electron transport layer, and an electron injection layer stacked sequentially, wherein the hole injection layer is in contact with the anode and the electron injection layer is in contact with the cathode.

[0081] In this invention, the surface of the cathode layer is preferably provided with a light extraction layer.

[0082] The present invention does not have any special requirements for the materials of the anode, hole injection layer, electron blocking layer, light-emitting layer, electron transport layer, electron injection layer and cathode; materials well known to those skilled in the art can be used.

[0083] As a specific embodiment of the present invention, the cross-sectional structural schematic diagram of the organic electroluminescent device is shown below. Figure 1 As shown. Figure 1 In the diagram, 1-substrate layer, 2-anode layer, 3-hole injection layer, 4-hole transport layer, 5-electron blocking layer, 6-light emitting layer, 7-electron transport layer, 8-electron injection layer, 9-cathode layer, and 10-light extraction layer.

[0084] Each organic layer in the organic electroluminescent device provided by the present invention is preferably prepared by vacuum evaporation, molecular beam evaporation, solvent-based dip coating, spin coating, rod coating, or inkjet printing. Metal electrodes are preferably prepared by evaporation or sputtering.

[0085] The following detailed description, in conjunction with embodiments, provides an organic compound with pyromellitic precipitate as its core, its preparation method and application, and an organic electroluminescent device provided by the present invention. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0086] Example 1: Synthesis of Compound 15

[0087]

[0088] In a 250ml three-necked flask under a nitrogen atmosphere, add 0.01mol of raw material A-1, 0.02mol of raw material B-1, 0.05mol of potassium tert-butoxide, and 1×10⁻⁶ kJ / L. -4 molPd2(dba)3, 1×10 -4 1 mol of triphenylphosphine, 200 ml of toluene, heated under reflux for 18 hours, sampled and spotted on TLC, the reaction was complete; cooled naturally, filtered, the filtrate was rotary evaporated, and passed through a silica gel column to obtain intermediate D-1.

[0089] In a 250ml three-necked flask under a nitrogen atmosphere, add 0.01mol of intermediate D-1, 0.012mol of raw material C-1, 0.03mol of potassium tert-butoxide, and 1×10⁻⁶ mol of [unspecified ingredient]. -4 molPd2(dba)3, 1×10 -4 mol triphenylphosphine, 150 mL toluene, heated under reflux for 20 hours, sampled and spotted on TLC plate; reaction completed; naturally cooled, filtered, filtrate rotary evaporated, and passed through silica gel column chromatography to obtain target compound 15; elemental analysis structure (molecular formula C15). 62 H 41 N3O2): Theoretical values: C, 86.59; H, 4.81; N, 4.89; Measured values: C, 86.44; H, 4.77; N, 5.01. LC-MS: Theoretical value: 859.32; Measured value: 859.44.

[0090] The following compounds were prepared using the same method as in Example 1, and the raw materials are shown in Table 1 below.

[0091] Table 1. Synthetic raw materials for different embodiments

[0092]

[0093]

[0094] The proton NMR data of different embodiments are shown in Table 2.

[0095] Table 2. Proton NMR data for different embodiments

[0096]

[0097]

[0098] The following examples 1-7 and comparative examples 1-4 detail the application effects of the organic compound with pyromellitic styrene as its core in the device provided by the present invention. The fabrication processes of the devices in examples 1-7 and comparative examples 2-4 are completely identical to those in comparative example 1, and the same substrate and electrode materials are used, with the electrode film thickness remaining consistent. The difference lies in the replacement of the hole transport layer material. The device structures obtained in each example are shown in Table 3, and the performance test results of the devices are shown in Table 4.

[0099] After completing the fabrication of the electroluminescent device according to the above steps, the current efficiency of the device was measured, and the results are shown in Table 4. The molecular structural formulas of the relevant materials are shown below:

[0100]

[0101]

[0102] Table 3 shows the device structures obtained from each application example.

[0103]

[0104] Table 4 shows the test data of the electroluminescent devices.

[0105]

[0106]

[0107] Note: Current efficiency was tested using an IVL (current-voltage-luminance) testing system at a current density of 10 mA / cm². 2 .

[0108] As can be seen from the results in Table 4, the compound with pyromellitic phosphine as the core prepared in this invention can be applied to the fabrication of organic electroluminescent devices. Compared with comparative examples 1 to 4, both the efficiency and lifetime are significantly improved compared with known organic electroluminescent materials.

[0109] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An organic compound with benzene as its core, having the structure shown in any one of Formula 16 or Formula 17: Formula 16; Formula 17.

2. The method for preparing the organic compound with pyromellitic ether as the core according to claim 1, characterized in that, The organic compound with benzene as its core has the structure shown in any one of Formula 16 or Formula 17, and the preparation method includes the following steps: A compound having the structure shown in formula a, a compound having the structure shown in formula b, and a compound having the structure shown in formula c undergo a first substitution reaction to obtain a compound having the structure shown in formula d. Formula a; Formula b; Formula c; Formula d; A compound having the structure shown in formula d undergoes a second substitution reaction with a compound having the structure shown in formula e to obtain an organic compound with pyromellitic as the core. Formula e.

3. The application of the organic compound with pyromellitic tin oxide as the core as described in claim 1 or the organic compound with pyromellitic tin oxide as the core prepared by the preparation method described in claim 2 in the preparation of organic electroluminescent devices.

4. An organic electroluminescent device, comprising a cathode, an anode, and an organic functional layer, wherein the organic functional layer is located between the anode and the cathode, characterized in that, The organic functional layer includes the organic compound with pyromellitic tin as the core as described in claim 1 or the organic compound with pyromellitic tin as the core prepared by the preparation method described in claim 2.

5. The organic electroluminescent device according to claim 4, characterized in that, The organic functional layer includes a hole transport region, a light-emitting region, and an electron transport region. The hole transport region includes an organic compound with pyromellitic tin as its core as described in claim 1 or an organic compound with pyromellitic tin as its core prepared by the preparation method described in claim 2.

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