Electron transport material containing triazine structure and organic electroluminescent device thereof

Abstract

The invention belongs to the technical field of organic electroluminescent materials, and particularly relates to an electron transport material containing a triazine structure and an organic electroluminescent device.The electron transport material with excellent performance is obtained by means of the electron deficiency characteristic of a triazine group, and meanwhile, along with continuous bond extension of aryl, the electron transport material with the excellent performance is obtained. The material types are enriched, the LUMO orbital energy level is optimized, the adaptability of the material is further improved on the basis of improving the stability of the material, and the application scene of the material is enriched.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescent materials, and in particular relates to an electron transport material containing a triazine structure and an organic electroluminescent device thereof. Background Art

[0002] In the field of small and medium-sized panels, the shipment volume of organic electroluminescent devices (OLEDs) has surpassed that of liquid crystal displays (LCDs) in 2024. As the application scenarios of OLEDs become more and more diverse, the requirements for the performance of organic electroluminescent materials are also becoming higher and higher. Obtaining high-efficiency and long-life devices remains the most important goal for their commercialization.

[0003] Since the synthesis process of existing organic electroluminescent materials is relatively complex and time-consuming, in view of the current industrial application requirements of OLED devices and the requirements of the optoelectronic properties of OLED devices, more suitable electroluminescent materials with high performance must be selected to achieve the comprehensive characteristics of high efficiency, long life and low voltage of the device. Therefore, the further development of organic electroluminescent compounds is imminent. Application-oriented organic electron transport materials should have high thermal stability, high electron mobility, and low LUMO energy level (favorable for electron injection). Although a large number of organic electron transport materials have been reported, it has always been challenging to design and synthesize organic small molecule electron transport materials with excellent comprehensive performance. Summary of the invention

[0004] In order to solve the problems existing in the background technology, the first object of the present invention is to provide an electron transport material containing a triazine structure, and the technical solution is as follows:

[0005] An electron transport material containing a triazine structure, the structure of which is shown in the following general formula (I):

[0006]

[0007] in, Indicates that R3 is connected by a single bond or does not exist; R1 is the same or different and is independently selected from substituted or unsubstituted aryl groups of 6 to 18 carbon atoms; R2 is the same and is selected from D or F, and m is an integer of 0 to 5; R3 is selected from substituted or unsubstituted aryl groups of 6 to 18 carbon atoms, substituted or unsubstituted heteroaryl groups of 3 to 18 carbon atoms;

[0008] When substitution is present, the substituent is selected from the group consisting of: D, F, cyano, methyl, isopropyl, tert-butyl, methoxy, phenyl, naphthyl, and pyridyl.

[0009] As a preferred embodiment of the present invention, the aromatic group of 6 to 18 carbon atoms is selected from the following structures:

[0010]

[0011] The heteroaryl group of 3 to 18 carbon atoms is selected from the following structures:

[0012]

[0013] As a preference in the present invention, m=0 or 5.

[0014] As a preferred embodiment of the present invention, its structure is one of the following structures:

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028] Another object of the present invention is to provide an organic electroluminescent device, comprising a first electrode, a second electrode and an organic material layer disposed therebetween, wherein the organic material layer comprises the above-mentioned electron transport layer material containing a triazine structure.

[0029] As a preferred embodiment of the present invention, the organic electroluminescent device is used to manufacture display devices, lighting sources, signal lights, and signboards. The display devices include mobile phone displays, computer displays, television displays, smart watch displays, smart car display panels, VR or AR helmet displays.

[0030] The beneficial effects of the present invention are as follows:

[0031] By utilizing the electron-deficient characteristics of the triazine group, an electron transport material with excellent performance is obtained. At the same time, with the continuous bonding expansion of the aromatic group, not only the types of materials of the present invention are enriched, but also the LUMO orbital energy level is optimized. On the basis of improving the stability of the material, the adaptability of the material is further improved, enriching the application scenarios of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0033] Figure 1 This is a comparison diagram of the current-voltage curves of single-electron devices prepared using compound 1 and comparative compounds 1 and 2. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] If the specific conditions are not specified in the embodiments, they are carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially. Some reaction compounds are purchased from commodity suppliers (Zhengzhou Alpha Chemical Co., Ltd.), and some compounds that cannot be directly purchased are prepared by simple reactions of commercially available raw materials. The percentages all refer to mass percentages, and the temperature is degrees Celsius (℃). Such method principles, operating procedures, conventional post-treatments, silica gel columns, recrystallization purification and other means are well known to synthesizers in the art, and the synthesis process can be fully realized to obtain the target product. The reactions in each preparation embodiment are generally carried out under positive pressure of nitrogen or argon.

[0036] Preparation Example

[0037] Example 1: Preparation of Compound 1

[0038]

[0039]

[0040] Synthesis of compound 1-2: Under nitrogen protection, compound 1-1 (2.64 g, 10 mmol), bis(pinacol)diboron (3.81 g, 15 mmol), potassium acetate (2.45 g, 25 mmol), tris(dibenzylideneacetone)dipalladium(0) (Pd2(dba)3) (0.92 g, 1 mmol), and tricyclohexylphosphine (0.28 g, 1 mmol) were added to 20 ml of dioxane, and the resulting mixture was heated under reflux. After the reaction was completed, the reaction product was cooled to room temperature, dissolved in a large amount of toluene, and filtered through silica gel. The organic layer obtained therefrom was concentrated, precipitated by pouring hexane thereto, and the precipitate was filtered to obtain compound 1-2 (3.10 g, yield 87%);

[0041] Synthesis of compound 1-4: Under nitrogen protection, compound 1-3 (1.88 g, 10 mmol), bis(pinacol)diboron (3.81 g, 15 mmol), potassium acetate (2.45 g, 25 mmol), tris(dibenzylideneacetone)dipalladium(0) (Pd2(dba)3) (0.92 g, 1 mmol), and tricyclohexylphosphine (0.28 g, 1 mmol) were added to 20 ml of dioxane, and the resulting mixture was heated under reflux. After the reaction was completed, the reaction product was cooled to room temperature, dissolved in a large amount of toluene, and filtered through silica gel. The organic layer obtained therefrom was concentrated, precipitated by pouring hexane thereto, and the precipitate was filtered to obtain compound 1-4 (2.47 g, yield 88%);

[0042] Synthesis of compound 1-6: Compound 1-5 (2.25 g, 10 mmol), compound 1-2 (4.27 g, 12 mmol), tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (0.23 g, 0.2 mmol), and sodium carbonate (Na2CO3) (2.12 g, 20 mmol) were added to 10 ml of toluene, 10 ml of dioxane, 10 ml of water, and the resulting mixture was stirred at a temperature of 80° C. for 20 hours. After adding toluene thereto, the product obtained therefrom was filtered through silica gel and recrystallized using toluene to obtain compound 1-6 (2.31 g, yield 55%);

[0043] Synthesis of compound 1: Compound 1-6 (2.10 g, 5 mmol), compound 1-4 (1.68 g, 6 mmol), tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (0.12 g, 0.1 mmol), and potassium phosphate (2.12 g, 10 mmol) were added to 100 ml of tetrahydrofuran, and the resulting mixture was stirred at a temperature of 80° C. for 20 hours. After adding toluene thereto, the product obtained therefrom was filtered through silica gel and recrystallized by using toluene to obtain compound 1 (2.20 g, yield 82%), MS: 537.34.

[0044] Example 2: Preparation of Compound 6

[0045]

[0046] The synthesis of compound 6-2 is the same as that of compound 1-4, except that compound 6-1 is used to replace compound 1-3;

[0047] The synthesis of compound 6 is the same as that of compound 1, except that compound 1-4 is replaced by compound 6-2, MS: 613.40.

[0048] Example 3: Preparation of Compound 9

[0049]

[0050] The synthesis of compound 9-2 is the same as that of compound 1-4, except that compound 9-1 is used to replace compound 1-3;

[0051] The synthesis of compound 9 is the same as that of compound 1, except that compound 1-4 is replaced by compound 9-2, MS: 538.35.

[0052] Example 4: Preparation of Compound 15

[0053]

[0054] The synthesis of compound 15-2 is the same as that of compound 1-2, except that compound 15-1 is used to replace compound 1-1;

[0055] The synthesis of compound 15-4 is the same as the synthesis of compound 1-4, except that compound 15-3 is used to replace compound 1-3;

[0056] The synthesis of compound 15-5 is the same as that of compound 1-6, except that compound 15-2 is used to replace compound 1-2;

[0057] The synthesis of compound 15 is the same as that of compound 1, except that compound 15-5 is used to replace compound 1-6, and compound 15-4 is used to replace compound 1-4, MS: 687.47.

[0058] Example 5: Preparation of Compound 26

[0059]

[0060]

[0061] The synthesis of compound 26-2 is the same as that of compound 1-2, except that compound 1-1 is replaced by compound 26-1;

[0062] The synthesis of compound 26-4 is the same as the synthesis of compound 1-4, except that compound 26-3 is used to replace compound 1-3;

[0063] The synthesis of compound 26-5 is the same as that of compound 1-6, except that compound 26-2 is used to replace compound 1-2;

[0064] The synthesis of compound 26 is the same as that of compound 1, except that compound 26-5 is used to replace compound 1-6, and compound 26-4 is used to replace compound 1-4, MS: 726.47.

[0065] Example 6: Preparation of Compound 32

[0066]

[0067] The synthesis of compound 32-2 is the same as the synthesis of compound 1-2, except that compound 1-1 is replaced by compound 32-1;

[0068] The synthesis of compound 32-3 is the same as the synthesis of compound 1-6, except that compound 1-2 is replaced by compound 32-2;

[0069] The synthesis of compound 32 is the same as that of compound 6, except that compound 1-6 is replaced by compound 32-3, MS: 713.38.

[0070] Example 7: Preparation of Compound 59

[0071]

[0072] The synthesis of compound 59-2 is the same as the synthesis of compound 1-2, except that compound 1-1 is replaced by compound 59-1;

[0073] The synthesis of compound 59-4 is the same as the synthesis of compound 1-4, except that compound 1-3 is replaced by compound 59-3;

[0074] The synthesis of compound 59-5 is the same as that of compound 1-6, except that compound 1-2 is replaced by compound 59-2;

[0075] The synthesis of compound 59 is the same as that of compound 1, except that compound 59-5 is used to replace compound 1-6, and compound 59-4 is used to replace compound 1-4, MS: 750.42.

[0076] Example 8: Preparation of Compound 76

[0077]

[0078] The synthesis of compound 76-2 is the same as that of compound 1-6, except that compound 1-5 is replaced by compound 76-1;

[0079] The synthesis of compound 76 is the same as that of compound 1, except that compound 1-6 is replaced by compound 76-2, MS: 532.31.

[0080] Example 9: Preparation of Compound 141

[0081]

[0082] The synthesis of compound 141-2 is the same as that of compound 1-2, except that compound 141-1 is used to replace compound 1-1;

[0083] The synthesis of compound 141-4 is the same as that of compound 1-6, except that compound 141-3 is used to replace compound 1-5, and compound 141-2 is used to replace compound 1-2;

[0084] The synthesis of compound 141 is the same as that of compound 1, except that compound 141-4 is used to replace compound 1-6, MS: 779.39.

[0085] Example 10: Preparation of Compound 175

[0086]

[0087] The synthesis of compound 175-2 is the same as that of compound 1-2, except that compound 175-1 is used to replace compound 1-1;

[0088] The synthesis of compound 175-4 is the same as the synthesis of compound 1-4, except that compound 175-3 is used to replace compound 1-3;

[0089] The synthesis of compound 175-5 is the same as that of compound 1-6, except that compound 175-2 is used to replace compound 1-2;

[0090] The synthesis of compound 175 was the same as that of compound 1, except that compound 175-5 was used to replace compound 1-6, and compound 175-4 was used to replace compound 1-4, MS: 739.48.

[0091] Example 11: Preparation of Compound 197

[0092]

[0093]

[0094] The synthesis of compound 197-2 is the same as that of compound 1-2, except that compound 197-1 is used to replace compound 1-1;

[0095] The synthesis of compound 197-3 is the same as the synthesis of compound 1-6, except that compound 197-2 is used to replace compound 1-2;

[0096] The synthesis of compound 197 was the same as that of compound 59, except that compound 59-5 was replaced by compound 197-3, MS: 644.44.

[0097] Example 12: Preparation of Compound 225

[0098]

[0099] The synthesis of compound 225-2 is the same as that of compound 1-2, except that compound 1-1 is replaced by compound 225-1;

[0100] The synthesis of compound 225-3 is the same as that of compound 1-6, except that compound 1-2 is replaced by compound 225-2;

[0101] The synthesis of compound 225 was the same as that of compound 26, except that compound 225-3 was used to replace compound 26-5, MS: 665.39.

[0102] In addition, it should be noted that other compounds of the present application can be obtained by referring to the preparation methods of the above-mentioned embodiments, so they will not be listed one by one here.

[0103] Device Embodiment

[0104] Preparation of Device Example 1:

[0105] A glass substrate coated with ITO (indium tin oxide) having a thickness of 500 angstroms as a thin film was placed in distilled water in which a detergent was dissolved and ultrasonically cleaned. After the ITO was cleaned for 30 minutes, ultrasonic cleaning was repeated twice with distilled water for 10 minutes, and then the substrate was ultrasonically cleaned with isopropyl alcohol, acetone, and methanol solvents, dried, transferred to a plasma cleaner for cleaning for 5 minutes, and then transferred to a vacuum depositor;

[0106] On the ITO transparent electrode, compound [HI] was thermally vacuum deposited to a thickness of 100 angstroms to form a hole injection layer; compound [HT] was vacuum deposited to 800 angstroms on the hole injection layer to form a hole transport layer; compound [BH] and compound [BD] were vacuum deposited to a thickness of 200 angstroms at a ratio of 97:3 on the hole transport layer to form a light emitting layer; compound 1 and compound [LiQ] (lithium quinoline) were vacuum deposited to a ratio of 1:1 on the light emitting layer to form an electron transport layer with a thickness of 300 angstroms; yttrium (Yb) and magnesium silver (1:9) were sequentially deposited on the electron transport layer to a thickness of 10 angstroms and 1000 angstroms, respectively, to form a cathode. The vacuum degree during deposition was maintained at 1×10 -7 Up to 5×10 -8 Entrust.

[0107] Preparation of device examples 2 to 12:

[0108] When forming the electron transport layer, the compound shown in Table 1 was used instead of Compound 1 in Device Example 1, and an organic electroluminescent device was prepared by the same method as in Example 1.

[0109] Preparation of Comparative Device Example 1-2:

[0110] An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that Comparative Compounds 1 and 2 were used instead of Compound 1 in Device Example 1 when forming the electron transport layer.

[0111] The structure of the compound used in the above preparation process is as follows:

[0112]

[0113] For the organic electroluminescent devices made using the compounds as electron transport layers in the examples and comparative examples, the 2 The driving voltage and current efficiency were measured at a current density of 50 mA / cm 2The time required for the brightness to decrease to 97% of the initial brightness (LT97) was measured at a current density of , wherein the dipole moment was calculated by Gaussian calculation software for the corresponding compound, and the results are shown in Table 1 below:

[0114] Table 1

[0115]

[0116]

[0117] As can be seen from the table, on the one hand, compared with Comparative Example 1, in terms of structure, the molecular skeleton of the embodiment and Comparative Example 2 has an "I"-shaped structure, and the molecule has an advantageous conformation, which makes it have a certain rigidity and a higher phase transition temperature, which can significantly improve the life of the device; on the other hand, it can be seen from the dipole moment data of the embodiment and the comparative example that the conformation in the molecular structure of Comparative Example 2 has the greatest influence on the electron cloud distribution (the dipole moment is the smallest, and the electron cloud distribution in the molecule is concentrated), see the attached Figure 1 (The device structure is ITO (50nm) / ET (50nm) / 50% Liq: ET (30nm) / Liq (2nm) / Al (100nm), wherein ET in different devices is compound 1, comparative compound 1, and comparative compound 2, respectively). Since the electron cloud distribution of compound 1 is more uniform, the carrier mobility of the single-electron device prepared therefrom is higher than that of the single-electron device prepared by comparative compound 2, indicating that the device prepared by using the compound provided in the present application as an electron transport layer can achieve both high efficiency and long life compared to the device prepared by using comparative compounds 1 and 2 as an electron transport layer.

Claims

1. An electron transport material containing a triazine structure, characterized in that: The structure is shown in the following general formula (I): in, Indicates that R3 is connected by a single bond or does not exist; R1 is the same or different and is independently selected from substituted or unsubstituted aryl groups of 6 to 18 carbon atoms; R2 is the same and is selected from D or F, and m is an integer of 0 to 5; R3 is selected from substituted or unsubstituted aryl groups of 6 to 18 carbon atoms, substituted or unsubstituted heteroaryl groups of 3 to 18 carbon atoms; When substitution is present, the substituent is selected from the group consisting of: D, F, cyano, methyl, isopropyl, tert-butyl, methoxy, phenyl, naphthyl, and pyridyl.

2. The electron transport material containing a triazine structure according to claim 1, characterized in that: The aromatic group of 6 to 18 carbon atoms is selected from the following structures: The heteroaryl group of 3 to 18 carbon atoms is selected from the following structures:

3. The electron transport material containing a triazine structure according to claim 1, characterized in that: m=0 or 5.

4. An electron transport material containing a triazine structure according to any one of claims 1 to 3, characterized in that: Its structure is one of the following:

5. An organic electroluminescent device, characterized in that: The invention comprises a first electrode, a second electrode and an organic material layer arranged therebetween, wherein the organic material layer comprises the electron transport layer material containing a triazine structure as claimed in any one of claims 1 to 4.

6. The organic electroluminescent device according to claim 5, characterized in that: The organic electroluminescent device is used to manufacture display devices, lighting sources, signal lights, and signboards. The display devices include mobile phone display screens, computer display screens, television display screens, smart watch display screens, smart car display panels, and VR or AR helmet display screens.

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