Boron-based electroluminescent compound and electroluminescent device

Abstract

The invention discloses an electroluminescent compound based on a boron element and an electroluminescent device. The compound has a structure as shown in a formula (1) or a formula (2). The boron element is introduced into the N-type main body material of the organic electroluminescent device, the performance of the device is improved, the luminous efficiency of the device is improved, the designed N-type main body material and a common P-type main body material can form a good Premix material, good P / N proportion stability and mass production stability are achieved in the evaporation process, and the performance of the device is improved. And the formed Premix material has more balanced carrier mobility, so that the luminous efficiency of the device is further improved, and the service life of the device is further prolonged. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the technical field of organic electroluminescence, and particularly relates to an electroluminescent compound based on boron element and an electroluminescent device. Background Art

[0002] Organic electroluminescence refers to the luminescence phenomenon generated by carrier injection under the action of an electric field in a light-emitting layer prepared from organic materials, and is usually used for display purposes. The composition structure of an organic electroluminescent device (OLED) includes a cathode, an anode, and an organic layer disposed therebetween. The organic layer generally includes a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, etc. For an organic electroluminescent device having the above-mentioned film layers, when a voltage is applied between the two electrodes, holes are injected from the anode into the organic layer, and electrons are injected from the cathode into the organic layer. When the holes and electrons meet, excitons are formed, thereby exciting the molecules of the light-emitting material and finally generating visible light.

[0003] The most important factor affecting the luminous efficiency of an organic electroluminescent device is the light-emitting material. In an organic electroluminescent device, if the compatibility between the light-emitting host materials is poor, it will lead to inefficient energy transfer to the doped material, resulting in a decrease in the luminous efficiency of the device. We found that for the P / N type red light-emitting host materials currently used in organic electroluminescent devices, as the evaporation time prolongs, the P / N material ratio will change greatly, resulting in large fluctuations in device performance, poor stability, and reduced yield. Summary of the Invention

[0004] The technical object of the present invention is to provide an improved light-emitting material to improve the performance of a device using the light-emitting material.

[0005] To achieve the above object, the technical solution provided by the present invention is as follows:

[0006] An electroluminescent compound based on boron element, characterized in that it has a structure shown in formula (1) or formula (2):

[0007]

[0008] In formula (1) or formula (2):

[0009] Ar1, Ar2, Ar3, and Ar4 are each independently selected from one of substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C5-C30 heteroaryl groups; the substituents of Ar1, Ar2, Ar3, and Ar4 are each independently selected from one or more of deuterium, deuterated or non-deuterated methyl groups, deuterated or non-deuterated C6-C20 aryl groups, deuterated or non-deuterated C5-C20 heteroaryl groups, halogens, and cyano groups;

[0010] R5, R6, and R7 are each independently hydrogen or deuterium, e and f each independently represent an integer from 0 to 2, and g represents an integer from 0 to 4.

[0011] As a more preferred embodiment, the electroluminescent compound of the present invention is characterized by having a structure represented by the following formula (1-1) or (1-2):

[0012]

[0013] In formula (1-1) and formula (1-2):

[0014] R1, R2, R3, and R4 each independently represent hydrogen or deuterium, X represents O or S, a, c, and d each independently represent an integer from 0 to 5, and b is an integer from 0 to 8.

[0015] As a preferred embodiment, one of the groups Ar1 and Ar2 is a phenyl group that is either deuterated or non-deuterated, and the other group is a dibenzofuranyl group that is either deuterated or non-deuterated; Ar3 and Ar4 each independently represent a phenyl group or a deuterated phenyl group, and Ar3 and Ar4 are the same or different groups.

[0016] As a preferred embodiment, the electroluminescent compound of the present invention based on boron element is selected from the following compounds:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028] An electroluminescent device, characterized in that it includes an anode, a cathode, and an organic layer formed between the anode and the cathode, and the organic layer contains the electroluminescent compound described in any one of the above.

[0029] Further, the organic layer includes a hole injection layer, a first hole transport layer, a second hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, and the light-emitting layer contains the boron element-based electroluminescent compound as described in any one of the above items.

[0030] The electroluminescent device is characterized in that the light-emitting layer contains a first host material compound and a second host material compound, wherein the first host material compound is selected from the boron element-based electroluminescent compounds as described in any one of the above items, and the second host material compound is formed by condensing 0-2 groups represented by formula (4-1) and 0-2 groups represented by formula (4-2) on the group represented by formula (3);

[0031]

[0032] In the above formula:

[0033] * represents a connection site. When formula (4-1) or formula (4-2) is condensed with the group represented by formula (3), it is connected to the adjacent site on its A benzene ring or B benzene ring; L1 is a direct bond, a phenyl group, or a biphenyl group;

[0034] Ar5 is selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C5-C30 heteroaryl groups, and the substituents of Ar5 are C3-C20 heteroaryl groups or C6-C20 aryl groups;

[0035] Y represents O, S, or NAr6 each time it appears, where Ar6 is selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C5-C30 heteroaryl groups, and the substituents of Ar6 are selected from C5-C20 heteroaryl groups or C6-C20 aryl groups.

[0036] As a preferred embodiment, the second host material compound has a structure represented by formula (5-1), (5-2), or (5-3):

[0037]

[0038] Among them,

[0039] Ar7 represents one of substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C5-C30 heteroaryl groups;

[0040] The substituents of Ar7 are selected from C6-C20 aryl groups or C5-C20 heteroaryl groups.

[0041] As a preferred embodiment, the second host material compound is selected from any one of the following compounds:

[0042]

[0043]

[0044] Beneficial effects

[0045] By introducing B (boron) element into the N-type host material of the organic electroluminescent host material, the carrier mobility of the material is improved, thereby improving the luminous efficiency of the device applying the material.

[0046] At the same time, compared with the prior art, the N-type host material (the first compound host material) designed by the present invention can form a good Premix material with some common P-type host materials (the second compound host material), so that it has good P / N ratio stability and mass production stability during the evaporation process, and the formed Premix material has a more balanced carrier mobility, thereby greatly improving the efficiency and life of the device. Brief description of the drawings

[0047] Figure 1 is a schematic structural diagram of the organic electroluminescent device provided by the present invention;

[0048] Figure 2 is the HPLC chart of Compound N1 of the present invention.

[0049] Figure 3 is the TGA spectrum of Compound N1 of the present invention.

[0050] Figure 4 is the DSC spectrum of Compound N1 of the present invention.

[0051] Figure 1 Each reference numeral in represents: 1 - anode, 2 - hole injection layer, 3 - first hole transport layer, 4 - second hole transport layer, 5 - light emitting layer, 6 - hole blocking layer, 7 - electron transport layer, 8 - electron injection layer, 9 - cathode. Detailed description of the invention

[0052] In order to further clarify the technical solution of the present invention, the present invention will be introduced in more detail below with reference to specific embodiments.

[0053] Unless otherwise specified, "aryl" in the specification refers to a group containing one or more aromatic rings, which includes but is not limited to benzene, naphthalene, phenanthrene, fluorene, acenaphthene, etc. "Heteroaryl" herein refers to a heteroaryl group obtained by replacing one or more C in the "aryl" structure with one or more heteroatoms (such as N, O, S, etc.).

[0054] The term "deuteration" in the specification refers to the re-coordination of at least one hydrogen of a certain group with a deuterium substituent group. "Deuterium" refers to a stable isotope of hydrogen, also known as heavy hydrogen, with the elemental symbol D.

[0055] For those not specified in the examples, they are carried out under conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0056] Example 1:

[0057]

[0058] The synthesis scheme of compound N1 is as follows:

[0059]

[0060] The specific preparation process of the synthesis scheme of compound N1:

[0061] Step 1: Add 25.9 g (0.1 mol) of the raw material into the reaction flask, add 300 ml of chloroform, cool down to -10 °C, and dropwise add 32.8 g (0.205 mol) of liquid bromine. After the addition is complete, react for 2 h, then add an aqueous solution of sodium bisulfite and stir for 30 min, then separate the layers. The organic phase is concentrated to dryness and purified by column chromatography to obtain approximately 25.2 g of compound 1 with a yield of 60%.

[0062] Step 2: In a 250 ml three-necked flask, sequentially add 25.1 g (60 mmol) of compound 1, 300 ml of THF, and 3.6 g of magnesium strip. Replace the nitrogen, heat to 50 °C and stir for 30 min; dissolve 13.14 g (60 mmol) of dimethyltin dichloride in 200 ml of toluene, and slowly drop the solution into the reaction system. After the addition is complete, let it rise to room temperature and react for 6 h. After the reaction is completed, add 60 ml of ice water to quench the reaction. Extract the reaction solution with DCM (200 ml * 3) and saturated brine (200 ml * 2) respectively. The organic phase is rotary evaporated to obtain an oil, and recrystallized with TOL (toluene) / EtOH to obtain 18.36 g of compound 2 with a yield of 75%.

[0063] Step 3: Add 18 g (44 mmol) of compound 2 into a 250 ml three-necked flask, sequentially add 7.32 g (44 mmol) of BBr3 and 200 ml of toluene, start stirring, replace the nitrogen, heat to 100 °C and reflux for 24 h, monitor the reaction end point by HPLC; introduce Cl2 and continue to react for 5 h; cool to room temperature, dry and pass through a column, and the organic phase is distilled under reduced pressure to obtain 12.42 g of compound 3 with a yield of 80%.

[0064] Step 4: Under nitrogen protection, add 12 g (34.4 mmol) of Compound 3 and 4.2 g (34.4 mmol) of phenylboronic acid into a 250 ml reaction flask. Then add 100 ml of toluene, 25 ml of ethanol, 9.5 g (68.8 mmol) of potassium carbonate, 25 ml of water, and 0.39 g (0.34 mmol) of the catalyst tetrakis(triphenylphosphine)palladium(0). Heat the mixture to reflux for 6 h. After the reaction is completed, cool it to room temperature, add 50 ml of water, separate the layers, concentrate the organic phase to dryness, and purify it by column chromatography to obtain 9.43 g of Compound 4 with a yield of 79%.

[0065] Step 5: Under nitrogen protection, add 9.2 g (26.5 mmol) of Compound 4 and 6.68 g (26.5 mmol) of boric acid compound into a 250 ml reaction flask. Then add 80 ml of toluene, 20 ml of ethanol, 7.3 g (53 mmol) of potassium carbonate, 20 ml of water, and 0.3 g (0.26 mmol) of the catalyst tetrakis(triphenylphosphine)palladium(0). Heat the mixture to reflux for 8 h. After the reaction is completed, cool it to room temperature, add 50 ml of water, separate the layers, concentrate the organic phase to dryness, and purify it by column chromatography to obtain 9.69 g of Compound 5 with a yield of 77%.

[0066] Step 6: Add 9.6 g (20 mmol) of Compound 5 into a 500 ml reaction flask. Then add 180 ml of dichloromethane, 180 ml of methanol, and 5.52 g (40 mmol) of potassium carbonate. Stir the mixture at room temperature for 4 h. After the reaction is completed, filter it by suction, and concentrate the filtrate to dryness to obtain approximately 7.1 g of Compound 6 with a yield of 88%.

[0067] Step 7: Under nitrogen protection, add 7 g (17.3 mmol) of Compound 6 into a 250 ml reaction flask. Then add 140 ml of toluene and 0.23 g (0.86 mmol) of platinum dichloride. Reflux the reaction for 6 hours, then turn off the heating. After cooling to room temperature, purify it by column chromatography to obtain 6.54 g of Compound 7 with a yield of 92.8%.

[0068] Step 8: Under nitrogen protection, add 6.5 g (16 mmol) of Compound 7 into a 250 ml reaction flask. Then add 65 ml of tetrahydrofuran, cool the temperature to -70 °C, and dropwise add 6.4 ml (2.5 M, 16 mmol) of n-butyllithium. After the addition is complete, stir for 30 min. Then dissolve 2.5 g (16 mmol) of bromobenzene in 10 ml of tetrahydrofuran and dropwise add it into the reaction solution. After the addition is complete, allow the reaction to naturally warm up to room temperature and react for 8 h. Quench the reaction with ice water, separate the layers, and concentrate the organic phase to obtain 5.88 g of Compound 8 with a yield of 90%.

[0069] Step 9: Under nitrogen protection, add 5.8 g (14 mmol) of Compound 8 into a 100 ml reaction flask, add 50 ml of dioxane, then add 4.26 g (16.8 mmol) of bis(pinacolato)diboron, followed by 3.4 g (35 mmol) of potassium acetate and 0.128 g (0.14 mmol) of catalyst Pd2(dba)3 and 0.133 g (0.28 mmol). Heat to reflux for 4 h, cool down, and then perform suction filtration. Purify the filter cake by column chromatography to obtain 6.1 g with a yield of 88.5%.

[0070] Step 10: Under nitrogen protection, add 6 g (12.1 mmol) of Compound 9 and 4.32 g (12.1 mmol) of the triazine raw material into a reaction flask, add 60 ml of toluene, 20 ml of ethanol, 3.34 g (24.2 mmol) of potassium carbonate, 20 ml of water, and 0.14 g (0.12 mmol) of tetrakis(triphenylphosphine)palladium. Reflux for 6 h, cool down, and then perform suction filtration. Purify the filter cake by column chromatography to obtain approximately 6.1 g of the target compound N1 with a yield of 73.5%.

[0071] Example 2:

[0072]

[0073] The synthesis scheme of Compound N113 is as follows:

[0074]

[0075] The specific preparation process of the synthesis scheme of Compound N1:

[0076] Step 1: Add 26.1 g (0.11 mol) of the raw material into a reaction flask, add 300 ml of chloroform, cool down to -10 °C, and dropwise add 33.2 g (0.215 mol) of liquid bromine. After the addition is complete, react for 2 h, then add an aqueous solution of sodium bisulfite and stir for 30 min. Separate the layers, concentrate the organic phase to dryness, and purify by column chromatography to obtain approximately 25.4 g of Compound 1 with a yield of 62%.

[0077] Step 2: Add 25.3 g (64 mmol) of Compound 1, 300 ml of THF, and 3.8 g of magnesium strip into a 250 ml three-necked flask in sequence. Replace the air with nitrogen, heat to 50 °C and stir for 30 min. Dissolve 13.2 g (60 mmol) of dimethyltin dichloride in 200 ml of toluene, and slowly add the solution dropwise to the reaction system. After the addition is complete, let it rise to room temperature naturally and react for 6 h. After the reaction is completed, add 60 ml of ice water to quench the reaction. Extract the reaction solution with DCM (200 ml * 3) and saturated brine (200 ml * 2) respectively. Rotate the organic phase to obtain an oily substance, and recrystallize it with TOL (toluene) / EtOH to obtain 18.42 g of Compound 2 with a yield of 77.1%.

[0078] Step 3: Add 18.2 g (44 mmol) of Compound 2 into a 250 ml three-necked flask, successively add 7.42 g (44 mmol) of BBr3 and 200 ml of toluene, start stirring, displace with nitrogen, heat to reflux at 100 °C, react for 24 h, and monitor the reaction end point by HPLC. Pass in Cl2 and continue to react for 5 h. Cool to room temperature, dry and column-chromatograph, and distill the organic phase under reduced pressure to obtain 12.52 g of Compound 3 with a yield of 82%.

[0079] Step 4: Under nitrogen protection, add 12.2 g (34.45 mmol) of Compound 3 and 4.3 g (34.48 mmol) of phenylboronic acid into a 250 ml reaction flask, add 100 ml of toluene, 25 ml of ethanol, 9.57 g (68.86 mmol) of potassium carbonate, 25 ml of water, and then add 0.43 g (0.38 mmol) of the catalyst tetrakis(triphenylphosphine)palladium(0). Heat to reflux and react for 6 h. After the reaction is completed, cool to room temperature, add 50 ml of water, separate the liquid, concentrate the organic phase to dryness, and purify by column chromatography to obtain 9.53 g of Compound 4 with a yield of 80%.

[0080] Step 5: Under nitrogen protection, add 9.32 g (26.56 mmol) of Compound 4 and 6.72 g (26.54 mmol) of boric acid compound into a 250 ml reaction flask, add 80 ml of toluene, 20 ml of ethanol, 7.35 g (55 mmol) of potassium carbonate, 20 ml of water, and then add 0.33 g (0.28 mmol) of the catalyst tetrakis(triphenylphosphine)palladium(0). Heat to reflux and react for 8 h. After the reaction is completed, cool to room temperature, add 50 ml of water, separate the liquid, concentrate the organic phase to dryness, and purify by column chromatography to obtain 9.72 g of Compound 5 with a yield of 77%.

[0081] Step 6: Add 9.53 g (22 mmol) of Compound 5 into a 500 ml reaction flask, add 180 ml of dichloromethane, 180 ml of methanol, 5.56 g (43 mmol) of potassium carbonate, stir at room temperature for 4 h. After the reaction is completed, filter by suction, and concentrate the filtrate to dryness to obtain approximately 7.16 g of Compound 6 with a yield of 89%.

[0082] Step 7: Under nitrogen protection, add 7 g (17.3 mmol) of Compound 6 into a 250 ml reaction flask, add 140 ml of toluene and 0.24 g (0.87 mmol) of platinum dichloride, reflux for 6 hours, then turn off the heating. After cooling to room temperature, purify by column chromatography to obtain 6.55 g of Compound 7 with a yield of 92.8%.

[0083] Step 8: Under nitrogen protection, add 6.47 g (16 mmol) of compound 7 into a 250 ml reaction flask, add 65 ml of tetrahydrofuran, cool down to -70 °C, dropwise add 6.4 ml (2.5 M, 16 mmol) of n-butyllithium. After complete addition, stir for 30 min. Then dissolve 2.5 g (16 mmol) of bromobenzene in 10 ml of tetrahydrofuran and dropwise add it into the reaction solution. After the addition is complete, let it rise to room temperature naturally and react for 8 h. Add ice water to quench the reaction. After liquid separation, concentrate the organic phase to obtain 5.88 g of compound 8, with a yield of 90%.

[0084] Step 9: Add 5.76 g (16 mmol) of compound 8 into a 250 ml reaction flask, add 65 ml of N,N-dimethylformamide, cool down to -5 °C, dropwise add 2.85 g (16 mmol) of N-bromosuccinimide dissolved in 20 ml of N,N-dimethylformamide. After complete addition, react for 4 h. Pour the reaction solution into water, and a solid will precipitate. Filter by suction to obtain 5.96 g of compound 9, with a yield of 86%.

[0085] Step 10: Under nitrogen protection, add 5.84 g (17 mmol) of compound 9 into a 100 ml reaction flask, add 50 ml of dioxane, add 4.29 g (16.9 mmol) of bis(pinacolato)diboron, then add 3.5 g (35 mmol) of potassium acetate and 0.13 g (0.14 mmol) of dichloropalladium(II) bis(diphenylphosphino)ferrocene. Heat under reflux for 4 h. After cooling, filter by suction, and purify the filter cake by column chromatography to obtain 6.16 g, with a yield of 88.5%.

[0086] Step 11: Under nitrogen protection, add 6.03 g (12.2 mmol) of compound 10 and 4.35 g (12.2 mmol) of the triazine raw material into a reaction flask, add 60 ml of toluene, 20 ml of ethanol, 3.38 g (24.3 mmol) of potassium carbonate, 20 ml of water, and 0.16 g (0.14 mmol) of tetrakis(triphenylphosphine)palladium. Heat under reflux for 6 h. After cooling, filter by suction, and purify the filter cake by column chromatography to obtain approximately 6.2 g of compound 11, with a yield of 76%.

[0087] The following compounds are obtained according to the similar methods of Example 1 and Example 2 above. The yields are shown in Table 1 below.

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] The synthetic identification results of the compounds prepared by the above method are shown in Table 2 below.

[0095] Table 2

[0096]

[0097] Basic performance tests were carried out on the above-synthesized compound materials, and the thermogravimetric temperature Td and the melting point temperature Tm were measured respectively. The test results are shown in Table 3 below.

[0098] Table 3

[0099] Compound Td / °C Tm / °C Compound Td / °C Tm / °C N1 516.69℃ 338.28℃ N86 524.95℃ 361.77℃ N3 528.64℃ 345.52℃ N89 513.79℃ 340.46℃ N6 535.12℃ 346.57℃ N97 510.82℃ 328.74℃ N13 528.74℃ 340.08℃ N99 519.89℃ 349.16℃ N17 512.10℃ 330.15℃ N113 509.32℃ 333.58℃ N22 537.41℃ 350.43℃ N121 514.72℃ 330.13℃ N24 543.43℃ 379.06℃ N129 512.94℃ 328.75℃ N25 510.34℃ 319.87℃ N131 527.34℃ 347.92℃ N27 537.42℃ 351.03℃ N145 515.88℃ 321.67℃ N33 509.34℃ 327.68℃ N150 527.82℃ 351.98℃ N38 538.20℃ 347.22℃ N155 519.64℃ 339.92℃ N41 510.97℃ 330.71℃ N161 507.98℃ 337.14℃ N48 535.91℃ 356.12℃ N169 514.31℃ 321.85℃ N55 501.67℃ 325.74℃ N171 530.09℃ 349.85℃ N57 498.71℃ 320.59℃ N177 513.10℃ 314.82℃ N63 540.14℃ 372.54℃ N179 528.16℃ 352.86℃ N70 524.19℃ 347.51℃ N185 516.17℃ 320.49℃ N73 495.15℃ 309.68℃ N195 521.75℃ 340.15℃ N81 511.52℃ 329.84℃

[0100] Note: The thermogravimetric temperature Td is the temperature at which the weight loss is 5% in a nitrogen atmosphere, and it is measured on a TGAN-1000 thermogravimetric analyzer with a nitrogen flow rate of 10 mL / min during the measurement; the melting point temperature Tm is measured by differential scanning calorimetry (DSC, Shinco DSC N-650) with a heating rate of 10 °C / min.

[0101] From the above data, it can be seen that the compounds synthesized in the present invention have excellent thermal stability, indicating that the compounds conforming to the structural general formula of the present invention all have excellent thermal stability and can meet the requirements for use as organic electroluminescent materials.

[0102] Device performance test:

[0103] Application Example 1:

[0104] ITO was used as the reflective layer anode substrate material, and it was surface-treated with water, acetone, and N 2 plasma in sequence;

[0105] Above the ITO anode substrate, 10 nm of HT-1 doped with 3% NDP-9 was deposited to form a hole injection layer (HIL);

[0106] Above the hole injection layer (HIL), 100 nm of HT-1 was evaporated to form the first hole transport layer (HTL);

[0107] Above the first hole transport layer (HTL), HT-2 was vacuum-evaporated to form a second hole transport layer with a thickness of 10 nm;

[0108] The compound N1 (N-type) prepared in Example 1 of the present invention and the compound P4 (P-type) are co-evaporated as the light-emitting host material in a ratio of 6:4, and RD-1 is used as the doping material (the amount of RD-1 is 3% of the total weight of the compound N1 and the compound P4), and evaporation is carried out on the second hole transport layer to form a light-emitting layer with a thickness of 30 nm;

[0109] HB-1 is evaporated onto the light-emitting layer to obtain a hole blocking layer (HBL) with a thickness of 20 nm;

[0110] ET-1 and Liq are co-evaporated onto the hole blocking layer (HBL) in a ratio of 5:5 to obtain an electron transport layer (ETL) with a thickness of 30 nm;

[0111] Magnesium (Mg) and silver (Ag) are mixed and evaporated in a ratio of 9:1 above the electron transport layer (ETL) to form an electron injection layer (ETL) with a thickness of 50 nm;

[0112] Thereafter, silver (Ag) is evaporated above the electron injection layer to form a cathode with a thickness of 100 nm. DNTPD with a thickness of 50 nm is deposited on the above cathode sealing layer. In addition, the cathode surface is sealed with a UV-curing adhesive and a packaging film (seal cap) containing a dehumidifying agent to protect the organic electroluminescent device from being affected by oxygen or moisture in the atmosphere. Thus, an organic electroluminescent device is prepared.

[0113] Other compounds used in the above process are as follows:

[0114]

[0115] Application Example 2-37:

[0116] Taking the compounds N1-N195 in Table 3 of the present invention as one of the host materials respectively, and P4, P8, P13 or P24 as the other host material, and under the conditions where other parts are the same as those in Application Example 1, the organic electroluminescent devices of Application Examples 2-37 are fabricated accordingly.

[0117] Comparative Examples 1-6: Taking the existing compounds J1, J2, J3 to replace the compound N1 as one of the host materials respectively, and P4, P8, P13 or P24 as the other host material, and under the conditions where other parts are the same as those in Application Example 1, the organic electroluminescent devices of Comparative Examples 1-6 are fabricated.

[0118]

[0119] The characteristics of the organic electroluminescent devices manufactured in the above application examples and the organic electroluminescent devices manufactured in the comparative examples are at a current density of 10 mA / cm 2It was measured under the condition that the luminescence color is red light, and the measurement results are shown in Table 4 below.

[0120] Table 4

[0121]

[0122]

[0123] As can be seen from Table 4 above, when the luminescent compound provided in the embodiment of the present invention is used as one of the host materials (N-type) of the light-emitting layer of an organic electroluminescent device, compared with the N-type host materials used in the prior art, when paired with the same P-type host material, at the same current density, the driving voltage of the organic electroluminescent device in the application example of the present invention is significantly reduced, and the luminous efficiency is improved.

[0124] After that, the organic electroluminescent devices prepared in Comparative Examples 1-3 and some Application Examples were selected for luminous lifetime testing to obtain the luminous lifetime T97% data (the time when the luminous brightness is reduced to 97% of the initial brightness). The testing equipment was the TEO luminous device lifetime testing system, and the testing condition was a current density of 10 mA / cm 2 , and taking the lifetime data of Comparative Example 1 as a reference, the results are shown in Table 5:

[0125] Table 5

[0126] Test group Luminescent layer material T97％ Test group Luminescent layer material T97％ Control Example 1 J1 + P4 100％ Application Example 8 N25 + P4 143％ Control Example 2 J2 + P4 118％ Application Example 9 N27 + P4 151％ Control Example 3 J3 + P4 105％ Application Example 10 N33 + P4 140％ Application Example 1 N1 + P4 144％ Application Example 11 N38 + P4 158％ Application Example 2 N3 + P4 147％ Application Example 12 N41 + P4 141％ Application Example 3 N6 + P4 160％ Application Example 13 N48 + P4 155％ Application Example 4 N13 + P4 155％ Application Example 14 N55 + P4 143％ Application Example 5 N17 + P4 145％ Application Example 31 N161 + P8 137％ Application Example 6 N22 + P4 159％ Application Example 32 N169 + P13 140％ Application Example 7 N24 + P4 168％ Application Example 36 N185 + P24 135％

[0127] As can be seen from Table 5, when the luminescent compound provided in the embodiment of the present invention is used as one of the host materials (N-type) of the light-emitting layer of an organic electroluminescent device, compared with the existing N-type host materials, after being paired with the same P-type host material, at the same current density, the service life of the device is significantly improved.

[0128] At the same time, the N-type host material designed by the present invention can form a good Premix material with the selected P-type host material, has good P / N ratio stability and mass production stability during the evaporation process, and the formed Premix material has a more balanced carrier mobility, thereby further improving the efficiency and life of the device.

[0129] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An electro-luminescent compound based on boron element, characterized in that, It has a structure represented by Formula (1) or Formula (2): In Formula (1) or Formula (2): Ar1, Ar2, Ar3, and Ar4 are each independently selected from a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C5-C30 heteroaryl group; the substituents of Ar1, Ar2, Ar3, and Ar4 are each independently selected from one or more of deuterium, deuterated or non-deuterated methyl, deuterated or non-deuterated C6-C20 aryl, deuterated or non-deuterated C5-C20 heteroaryl, halogen, and cyano. R5, R6, and R7 are each independently hydrogen or deuterium, e and f each independently represent an integer from 0 to 2, and g represents an integer from 0 to 4.

2. The electro-luminescent compound based on boron element according to claim 1, characterized in that, Formula (1) is expressed by Formula (1-1): In Formula (1-1): R1, R2, R3, and R4 each independently represent hydrogen or deuterium, X represents O or S, a, c, and d each independently represent an integer from 0 to 5, and b is an integer from 0 to 8.

3. The electro-luminescent compound based on boron element according to claim 1, characterized in that, Formula (2) is expressed by Formula (2-1): In Formula (2-1): R1, R2, R3, and R4 each independently represent hydrogen or deuterium, X represents O or S, a, c, and d each independently represent an integer from 0 to 5, and b is an integer from 0 to 8.

4. The boron-based electroluminescent compound according to claim 1, characterized in that: One of the groups of Ar1 and Ar2 is a deuterated or non-deuterated phenyl group, and the other group is a deuterated or non-deuterated dibenzofuranyl group; Ar3 and Ar4 each independently represent a phenyl group or a deuterated phenyl group, and Ar3 and Ar4 are the same or different groups.

5. The electro-luminescent compound based on boron element according to claim 1, characterized in that, Any one selected from the following compounds:

6. An electroluminescent device, characterized in that, It includes an anode, a cathode, and an organic layer formed between the anode and the cathode, and the organic layer contains the boron-based electroluminescent compound according to any one of claims 1-5.

7. The electroluminescent device according to claim 6, characterized in that, The organic layer includes a hole injection layer, a first hole transport layer, a second hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, and the light-emitting layer contains the boron-based electroluminescent compound according to any one of claims 1-5.

8. The electroluminescent device according to claim 6, wherein, The light-emitting layer contains a first host material compound and a second host material compound, wherein the first host material compound is selected from the boron-based electroluminescent compounds according to any one of claims 1-5, and the second host material compound is formed by fusing 0-2 groups represented by Formula (4-1) and 0-2 groups represented by Formula (4-2) to the group represented by Formula (3); In the above formula: * represents the connection site. When Formula (4-1) or Formula (4-2) is fused to the group represented by Formula (3), it is connected to the adjacent site on its A benzene ring or B benzene ring; L1 is a direct bond, a phenyl group, or a biphenyl group; Ar5 is selected from a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C5-C30 heteroaryl group, and the substituent of Ar5 is a C3-C20 heteroaryl group or a C6-C20 aryl group; Y represents O, S or NAr6, which is the same or different each time it appears, and Ar6 is selected from substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted C5-C30 heteroaryl, and the substituents of Ar6 are selected from C5-C20 heteroaryl or C6-C20 aryl.

9. The electroluminescent device according to claim 8, characterized in that, The second host material compound has a structure represented by Formula (5-1), (5-2) or (5-3): Wherein, Ar7 represents one of substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted C5-C30 heteroaryl; The substituents of Ar7 are selected from C6-C20 aryl or C5-C20 heteroaryl.

10. The electroluminescent device according to claim 8, wherein the second host material compound is selected from any one of the following compounds:

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