Compound, organic electroluminescent device and display device

Abstract

The invention discloses a compound, an organic electroluminescent device and a display device. The compound has a structure as shown in a formula (I). When the compound is applied to the organic light-emitting device and the display device, the compound is contained in an organic layer of the organic light-emitting device, and the compound is especially suitable for preparation of a hole transport layer. The invention aims to improve the performance of the organic electroluminescent compound material through reasonable introduction of deuterium so as to improve the luminous efficiency and prolong the service life of the luminescent device and the application device, and through reasonable design of the deuteration position, the deuteration has economical efficiency while improving the performance of the material and the device. # imgabs0 # (I).

Description

Technical Field

[0001] The present invention relates to the technical field of electroluminescence, and in particular to a compound, an organic electroluminescent device and a display device. Background Art

[0002] OLED, the full name of which is Organic Light-Emitting Diode, is a current-type organic light-emitting device. Its working principle is that under the action of the electric field, the holes generated by the anode and the electrons generated by the cathode move, are injected into the hole transport layer and the electron transport layer respectively, and migrate to the light-emitting layer. When the holes and electrons meet in the light-emitting layer, energy excitons are generated, thereby exciting the molecules of the light-emitting material to finally produce visible light. Deuterium (D) is a stable form of non-radioactive isotope in nature, with a larger atomic mass than hydrogen. Studies have shown that the introduction of deuterium atoms into OLED materials can stabilize the molecular structure, improve the luminous efficiency and stability of OLED devices, and extend the service life. However, through practical verification, whether the introduction of deuterium can specifically improve the performance of materials and devices is also related to the method of introduction, and the introduction of deuterium materials will lead to a significant increase in production costs. Therefore, at a certain cost, how to reasonably introduce deuterium and other modifying groups to achieve more cost-effective materials and device performance improvements is a problem worthy of attention in the industry. Summary of the invention

[0003] The purpose of the present invention is to provide a compound, an organic electroluminescent device and a display device in view of the above problems.

[0004] The purpose of the present invention is achieved through the following technical solutions: A compound, characterized in that it has a structure as shown in formula (I): (I) In the above formula: Ar1 and Ar2 each independently represent different groups, and one of the groups is dimethylfluorene, and the other group is a substituted or unsubstituted C6-C30 aryl group or C6-C30 heteroaryl group, the substituent of the C6-C30 aryl group is selected from one or more of an alkyl group, a deuterated alkyl group, a phenyl group, a phenyl group substituted by an alkyl group, and a phenyl group substituted by a deuterated alkyl group; the substituent of the C6-C30 heteroaryl group is selected from a deuterated or undeuterated C6-C20 aryl group; (D)m represents m deuterium substituents connected to the benzene ring, and m represents an integer of 1-5; (D)n represents n deuterium substituents connected to the benzene ring, and n represents an integer of 1-4.

[0005] As a preferred embodiment, one of Ar1 and Ar2 is dimethylfluorene, and the other is selected from a diphenyl group, a terphenyl group, a diphenyl group substituted with a methyl group or a phenyl group, and a diphenyl group substituted with a deuterated methyl group.

[0006] As a preferred embodiment, one of Ar1 and Ar2 is dimethylfluorene, and the other is selected from substituted or unsubstituted oxafluorene groups, and the substituent of the oxafluorene group is phenyl or deuterated phenyl.

[0007] As a preferred embodiment, m is 5 and n is 4.

[0008] As a preferred embodiment, one of Ar1 and Ar2 is selected from a group represented by any one of the structural formulas of Formula (1-1) to Formula (1-5), and the other is selected from a group represented by any one of the structural formulas of Formula (2-1) to Formula (2-4):

[0009] Among them, R1 and R2 are the same or different and represent phenyl, methyl or deuterated methyl; R3 and R4 are the same or different and represent phenyl or deuterated phenyl; i, j, p, q each independently represent an integer of 0 or 1; X represents O or S; * represents a connection site.

[0010] As a preferred embodiment, formula (I) is represented by structural formula (I-1) or (I-2):

[0011] Wherein, R1 and R2 are the same or different and represent phenyl, methyl or deuterated methyl; R3 and R4 are the same or different and represent phenyl or deuterated phenyl; i, j, p, q each independently represent an integer of 0 or 1; and X represents O or S.

[0012] As a preferred embodiment, the compound is selected from one of the following compounds:

[0013] An organic electroluminescent device, characterized in that it comprises a first electrode, a second electrode and an organic layer formed therebetween, wherein the organic layer contains the compound described in any of the above schemes.

[0014] Preferably, the organic layer comprises 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, wherein the first hole transport layer or the second hole transport layer contains the compound as described in any one of the above items.

[0015] A display device, characterized by comprising the organic electroluminescent device as described in any one of the above items.

[0016] Beneficial effects of the present invention: 1) The present invention improves the stability of the organic electroluminescent compound material by introducing deuterium, thereby improving the stability and service life of the light-emitting device using the material; 2) In the compounds of the present invention, since the introduction position of deuterium is at the active site of the compound structure, compared with the compounds that are fully deuterated or heavily deuterated but not deuterated at the active site, the deuteration of the compounds of the present invention improves the performance of materials and devices while being economical; 3) While the deuterated compounds of the present invention improve stability, the molecular weight of the compounds is effectively controlled, which is beneficial to the control of the evaporation temperature and sublimation temperature of the compounds, thereby improving the stability and yield of the production line; 4) The compound of the present invention has good carrier mobility, and good carrier mobility improves the luminous efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of an organic electroluminescent device provided by the present invention; Figure 2 HPLC chart of compound 4 prepared in Example of the present invention; Figure 3The DSC spectrum of compound 4 prepared in the embodiment of the present invention; Figure 4 This is the TGA spectrum of compound 4 prepared in the example of the present invention.

[0018] Figure 1 The reference numerals in the figure represent: 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

[0019] In order to further illustrate the technical solution of the present invention, the present invention is described in more detail below in conjunction with specific examples. If no specific conditions are specified in the examples, the conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0020] Embodiment 1:

[0021] Compound 4 was prepared as follows: Step S1:

[0022] Add SM1 (50 g, 0.256 mol, 1 eq) and ultra-dry THF (250 ml) into a 1 L three-necked flask, cool to below -65 °C, add 2.5 M n-butyl lithium (107.5 ml, 0.269 mol, 1.05 eq) dropwise, stir for 1 h, add SM2 (27 g, 0.2432 mol, 0.95 eq) in ultra-dry THF (135 ml) dropwise, add dropwise, stir at room temperature overnight; The reaction was stopped, quenched by adding 400 ml of saturated aqueous ammonium chloride solution, stirred and separated, the aqueous phase was extracted with DCM, the organic phases were combined, dried over anhydrous sodium sulfate, and the filtrate was concentrated to dryness under reduced pressure and used directly in the next reaction without purification.

[0023] Step S2:

[0024] Add ZJ1 (theoretical 55.35g, 0.2432mol, 1eq), I2 (98.8g, 0.289mol, 1.6eq), potassium carbonate (100.8g, 0.7296mol, 3eq) and tert-butyl alcohol (500ml) into a 1L three-necked flask. Heat to 90℃ and stir to react for 20h~24h under N2 protection. The reaction was stopped, quenched by adding 500 ml of 50% aqueous sodium thiosulfate solution, extracted three times by adding EA (300 ml*3), the organic phases were combined, washed twice with water, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated to dryness under reduced pressure to obtain 53.88 g of a yellow oil with a two-step yield of 98.2%.

[0025] Step S3:

[0026] SM3 (58.61 g, 0.251 mol, 1 eq) and ultra-dry THF (300 ml) were added to a 1 L three-necked flask, and the temperature was lowered to below -65 °C. 2.5 M n-butyl lithium (106 ml, 0.264 mol, 1.05 eq) was added dropwise. After the addition was completed, the mixture was stirred at this temperature for 30 min. A solution of ZJ2 (53.88 g, 0.239 mol, 0.95 eq) in ultra-dry THF (200 ml) was added dropwise. After the addition was completed, the mixture was stirred at room temperature and reacted overnight. The reaction was stopped, quenched by adding 400 ml of saturated aqueous ammonium chloride solution, stirred and separated, the aqueous phase was extracted with DCM, the organic phases were combined, dried over anhydrous sodium sulfate, and the filtrate was concentrated to dryness under reduced pressure and used directly in the next reaction without purification.

[0027] Step S4:

[0028] Add ZJ3 (theoretical 90.8 g, 0.239 mol, 1 eq) and DCM (450 ml) to a 1 L single-necked flask, cool to below 0 °C, add methanesulfonic acid (91.9 g, 0.956 mol, 4 eq), move to room temperature and stir for 1-2 h, monitor ZJ3 ≤ 0.5% by HPLC; Stop the reaction, add 200 ml of ethanol, concentrate under low temperature and reduced pressure to remove most of the DCM until there is almost no droplet, filter, rinse the filter cake with ethanol 3 to 4 times, and dry the filter cake at 85°C to obtain 60.5 g of gray solid, with a two-step yield of 70%.

[0029] Step S5:

[0030] ZJ4 (40 g, 0.111 mol, 1 eq), SM4 (39.97 g, 0.111 mol, 1 eq), sodium tert-butoxide (12.8 g, 0.1332 mol, 1.2 eq), XPhos (2.12 g, 4.44 mmol, 0.04 eq) and toluene (400 ml) were added to a 1 L three-necked flask. Palladium acetate (0.5 g, 2.22 mmol, 0.02 eq) was added under N2 protection. After the addition was completed, the temperature was raised to 100 °C and stirred for reaction. ZJ4 was monitored by HPLC to be ≤ 0.5%; Stop the reaction, filter through silica gel while hot, concentrate the filtrate to dryness under reduced pressure, add 100 ml of toluene and 400 ml of ethanol, stir and beat at 65°C for 2 h, cool and stir to crystallize overnight, filter, recrystallize the filter cake with toluene / ethanol 3 times, filter, recrystallize the filter cake with toluene once, filter, and dry the filter cake at 85°C to obtain 45.13 g of off-white solid with HPLC purity of 99.9642% and a yield of 59.2%.

[0031] The following other compounds were obtained by a similar method, see Table 1-1, Table 1-2, Table 1-3, Table 1-4, Table 1-5, Table 1-6, Table 1-7, Table 1-8, Table 1-9, Table 1-10, Table 1-11, Table 1-12, Table 1-13, Table 1-14, Table 1-15, Table 1-16, Table 1-17, Table 1-18 for details.

[0032] Table 1-1

[0033] Table 1-2

[0034] Table 1-3

[0035] Table 1-4

[0036] Table 1-5

[0037] Table 1-6

[0038] Table 1-7

[0039] Table 1-8

[0040] Table 1-9

[0041] Table 1-10

[0042] Table 1-11

[0043] Table 1-12

[0044] Table 1-13

[0045] Table 1-14

[0046] Table 1-15

[0047] Table 1-16

[0048] Table 1-17

[0049] Table 1-18

[0050] The synthesis and identification results of the compounds prepared by the above method are shown in Table 2 below.

[0051] Table 2 Compound FD-Quality Compound FD-Quality 1 m / z=686.34 (C52H30D9N=686.36) 3 m / z=700.35 (C53H32D9N= 700.37) 4 m / z=686.35 (C52H30D9N=686.36) 9 m / z=700.34 (C53H32D9N= 700.37) 12 m / z= 703.38 (C53H29D12N=703.39) 13 m / z=700.35 (C53H32D9N= 700.37) 16 m / z= 703.35 (C53H29D12N=703.39) 19 m / z=700.38 (C53H32D9N= 700.37) 21 m / z= 700.35 (C53H32D9N=700.37) 23 m / z=700.40 (C53H32D9N= 700.37) 24 m / z= 703.40 (C53H29D12N=703.39) 26 m / z=703.39 (C53H29D12N= 703.39) 34 m / z= 703.38 (C53H29D12N=703.39) 36 m / z=703.38 (C53H29D12N= 703.39) 38 m / z=714.37 (C54H34D9N=714.39) 43 m / z= 720.40 (C54H28D15N=720.42) 48 m / z=714.35 (C54H34D9N=714.39) 49 m / z= 714.40 (C54H34D9N=714.39) 51 m / z= 720.40 (C54H28D15N=720.42) 57 m / z=714.37 (C54H34D9N=714.39) 58 m / z=714.40 (C54H34D9N=714.39) 60 m / z=720.39 (C54H28D15N=720.42) 67 m / z=720.39 (C54H28D15N=720.42) 69 m / z=720.38 (C54H28D15N=720.42) 71 m / z=686.35 (C52H30D9N=686.36) 73 m / z=700.35 (C53H32D9N= 700.37) 74 m / z=686.34(C52H30D9N=686.36) 79 m / z=700.35 (C53H32D9N= 700.37) 82 m / z= 703.35 (C53H29D12N=703.39) 83 m / z=700.36 (C53H32D9N= 700.37) 86 m / z= 703.32 (C53H29D12N=703.39) 89 m / z=700.41 (C53H32D9N= 700.37) 91 m / z=700.39 (C53H32D9N= 700.37) 93 m / z=700.40 (C53H32D9N= 700.37) 94 m / z=703.41(C53H29D12N=703.39) 96 m / z=703.41(C53H29D12N=703.39) 104 m / z=703.40(C53H29D12N=703.39) 106 m / z=703.40(C53H29D12N=703.39) 108 m / z=714.41(C54H34D9N=714.39) 113 m / z=720.43(C54H28D15N=720.42) 118 m / z=714.38(C54H34D9N=714.39) 119 m / z=714.40(C54H34D9N=714.39) 121 m / z=720.39(C54H28D15N=720.42) 127 m / z=714.42(C54H34D9N=714.39) 128 m / z=714.38(C54H34D9N=714.39) 130 m / z=720.45(C54H28D15N=720.42) 137 m / z=720.38(C54H28D15N=720.42) 139 m / z=720.39(C54H28D15N=720.42) 141 m / z=686.37(C52H30D9N=686.36) 143 m / z=686.34(C52H30D9N=686.36) 147 m / z=700.35(C53H32D9N= 700.37) 148 m / z=703.31(C53H29D12N=703.39) 149 m / z=700.34(C53H32D9N= 700.37) 152 m / z=703.35(C53H29D12N=703.39) 153 m / z=700.32(C53H32D9N= 700.37) 156 m / z=703.35(C53H29D12N=703.39) 157 m / z=700.37(C53H32D9N= 700.37) 162 m / z=703.37(C53H29D12N=703.39) 164 m / z=703.38(C53H29D12N=703.39) 168 m / z= 700.14(C52H28D9ON=700.34 ) 169 m / z=776.31(C58H32D9ON=776.37 ) 172 m / z= 776.35(C58H32D9ON=776.37) 174 m / z=776.37(C58H32D9ON=776.37 ) 176 m / z=700.33(C52H28D9ON=700.34 ) 177 m / z= 700.33(C52H28D9ON=700.34 ) 178 m / z= 700.31(C52H28D9ON=700.34 ) 179 m / z=776.35(C58H32D9ON=776.37) 181 m / z= 775.34 (C58H32D9ON=776.37) 183 m / z=700.32 (C52H28D9ON=700.34) 185 m / z=700.32 (C52H28D9ON=700.34) 187 m / z=700.35 (C52H28D9ON=700.34) 188 m / z=776.35 (C58H32D9ON=776.37) 190 m / z=700.18 (C52H28D9ON=700.34) 193 m / z=700.25 (C52H28D9ON=700.34) 195 m / z=700.29 (C52H28D9ON=700.34) The above materials were subjected to basic performance tests, including thermal weight loss temperature Td and melting point temperature Tm. The test results are shown in Table 3 below.

[0052] Table 3 Test material (compound) Td / ℃ Tm / ℃ Test material (compound) Td / ℃ Tm / ℃ 1 417.66℃ 200.76℃ 3 409.12℃ 198.33 ℃ 4 419.59℃ 205.43℃ 9 410.97℃ 197.54℃ 12 412.30℃ 201.61℃ 13 410.64℃ 197.10℃ 16 413.14℃ 205.12℃ 19 413.21℃ 204.62℃ 21 412.60℃ 204.98℃ 23 411.59℃ 204.61℃ 24 414.79℃ 203.14℃ 26 413.60℃ 205.41℃ 34 413.55℃ 204.36℃ 36 412.98℃ 203.69℃ 38 389.84℃ 186.45℃ 43 392.69℃ 184.95℃ 49 390.10℃ 190.35℃ 49 389.41℃ 187.64℃ 51 393.61℃ 192.64℃ 57 390.43℃ 192.68℃ 58 391.20℃ 192.76℃ 60 394.01℃ 185.94℃ 67 393.32℃ 187.69℃ 69 392.64℃ 186.91℃ 71 416.64℃ 196.77℃ 73 410.95℃ 203.64℃ 74 417.69℃ 198.96℃ 79 411.31℃ 202.37℃ 82 412.75℃ 195.64℃ 83 413.10℃ 200.76℃ 86 414.20℃ 195.30℃ 89 412.12℃ 200.31℃ 91 409.32℃ 191.37℃ 93 413.25℃ 197.56℃ 94 415.02℃ 205.97℃ 96 414.92℃ 199.67℃ 104 416.20℃ 204.16℃ 106 414.98℃ 197.46℃ 108 403.13℃ 188.43℃ 113 406.84℃ 192.37℃ 118 404.50℃ 190.51℃ 119 402.17℃ 188.19℃ 121 407.21℃ 195.39℃ 127 404.64℃ 190.62℃ 128 403.55℃ 187.98℃ 130 407.30℃ 190.34℃ 137 408.21℃ 190.57℃ 139 406.85 ℃ 189.78℃ 141 417.61℃ 200.61℃ 143 416.14℃ 197.56℃ 147 409.26℃ 198.55℃ 148 411.31℃ 200.85℃ 149 408.85℃ 196.34℃ 152 409.14℃ 195.68℃ 153 408.10℃ 196.79℃ 156 410.87℃ 201.74℃ 157 407.66℃ 194.64℃ 162 410.20℃ 200.05℃ 164 411.10℃ 205.87℃ 168 425.64℃ 215.62℃ 169 430.14℃ 220.54℃ 172 431.42℃ 222.76℃ 174 424.34℃ 217.95℃ 176 425.32℃ 215.10℃ 177 426.21℃ 215.42℃ 178 424.75℃ 217.95℃ 179 430.10℃ 219.85℃ 181 430.91℃ 224.15℃ 183 425.31℃ 214.39℃ 185 425.21℃ 218.47℃ 187 426.32℃ 220.72℃ 188 432.32℃ 227.54℃ 190 424.10℃ 220.54℃ 193 426.69℃ 223.10℃ 195 425.33℃ 219.32℃ Note: Thermogravimetric temperature Td is the temperature at which the weight loss is 5% in a nitrogen atmosphere, and is measured on a TGA N-1000 thermogravimetric analyzer with a nitrogen flow rate of 10 mL / min. The melting point temperature Tm is measured by differential scanning calorimetry (DSC, Shinco DSC N-650) with a heating rate of 10°C / min.

[0053] It can be seen from the above data that the compound synthesized in the present invention has excellent thermal stability and can meet the requirements for use of organic electroluminescent materials.

[0054] Device performance test: Application Example 1: The organic electroluminescent device is prepared by the following process: ITO was used as the reflective layer anode substrate material, and its surface was treated with water, acetone, and N2 plasma in sequence; On top of the ITO anode substrate, 10 nm of HT-1 doped with 5% NDP-9 was deposited to form a hole injection layer (HIL); 100 nm of HT-1 was evaporated on the hole injection layer (HIL) to form the first hole transport layer (HTL); Vacuum evaporating the compound 4 of the present invention on the first hole transport layer (HTL) to form a second hole transport layer (GPL) with a thickness of 10 nm; GH-2 and GH-1 were co-evaporated at a ratio of 5:5 (mass ratio) as the main luminescent materials, and GD-1 was evaporated as the doping material (the amount of GD-1 was 8% of the total weight of GH-1 and GH-2) on the second hole transport layer (GPL) to form a luminescent layer with a thickness of 20 nm; HB-1 was evaporated onto the light-emitting layer to obtain a hole blocking layer (HBL) with a thickness of 20 nm; ET-1 and LiQ were co-evaporated onto the hole blocking layer (HBL) at a ratio of 5:5 to obtain an electron transport layer (ETL) with a thickness of 30 nm; Magnesium (Mg) and silver (Ag) are mixed in a ratio of 9:1 and evaporated on the electron transport layer (ETL) to form an electron injection layer (EIL) with a thickness of 50nm; silver (Ag) is then evaporated on the electron injection layer to form a cathode with a thickness of 100nm, and DNTPD with a thickness of 50nm is deposited on the cathode sealing layer; In addition, the cathode surface is sealed with a UV curable adhesive and a seal cap containing a dehumidifier to protect the organic electroluminescent device from being affected by oxygen or moisture in the atmosphere, thereby preparing an organic electroluminescent device.

[0055] Other compounds used in the above process are as follows:

[0056] Application Example 2-75: The other compounds synthesized in Table 1-1, Table 1-2, Table 1-3, Table 1-4, Table 1-5, Table 1-6, Table 1-7, Table 1-8, Table 1-9, Table 1-10, Table 1-11, Table 1-12, Table 1-13, Table 1-14, Table 1-15, Table 1-16, Table 1-17, and Table 1-18 are used as the second hole transport layer material, and the other parts are consistent with the conditions in Application Example 1 to produce the organic electroluminescent device of Application Example 2-75.

[0057] Comparative Examples 1-6: Compounds P1-P6 were used as the second hole transport layer materials respectively, and other parts were in accordance with the same conditions as those in Application Example 1 to prepare organic electroluminescent devices of Comparative Examples 1-6.

[0058] The structures of the compounds P1-P6 are as follows:

[0059] The characteristics of the organic electroluminescent device manufactured in the above application example and the organic electroluminescent device manufactured in the control example are that at a current density of 10 mA / cm 2 The results were shown in Table 4 below.

[0060] Table 4 Test items Second hole transport layer compound Voltage (V) Luminous efficiency (Cd / A) Test items Second hole transport layer compound Voltage (V) Luminous efficiency (Cd / A) Comparative Example 1 P1 3.82 160.8 Application Example 36 96 3.16 215.6 Comparative Example 2 P2 3.51 189.8 Application Example 37 104 3.13 217.1 Comparative Example 3 P3 3.69 170.1 Application Example 38 106 3.16 215.3 Comparative Example 4 P4 3.49 194.9 Application Example 39 108 3.18 213.9 Comparative Example 5 P5 3.75 167.4 Application Example 40 113 3.09 219.8 Comparative Example 6 P6 3.60 178.2 Application Example 41 118 3.18 213.9 Application Example 1 1 3.48 204.0 Application Example 42 119 3.20 212.7 Application Example 2 3 3.44 208.1 Application Example 43 121 3.11 216.9 Application Example 3 4 3.45 207.3 Application Example 44 127 3.20 213.0 Application Example 4 9 3.44 207.9 Application Example 45 128 3.20 213.1 Application Example 5 12 3.15 215.5 Application Example 46 130 3.01 220.3 Application Example 6 13 3.40 208.9 Application Example 47 137 3.05 219.7 Application Example 7 16 3.16 215.8 Application Example 48 139 3.15 217.8 Application Example 8 19 3.39 209.2 Application Example 49 141 3.44 207.8 Application Example 9 21 3.37 210.3 Application Example 50 143 3.45 206.7 Application Example 10 23 3.45 207.9 Application Example 51 147 3.40 208.1 Application Example 11 24 3.16 215.4 Application Example 52 148 3.17 214.9 Application Example 12 26 3.20 213.0 Application Example 53 149 3.38 209.2 Application Example 13 34 3.12 216.3 Application Example 54 152 3.15 215.8 Application Example 14 36 3.46 205.7 Application Example 55 153 3.44 207.3 Application Example 15 38 3.17 214.0 Application Example 56 156 3.16 214.6 Application Example 16 43 3.07 219.8 Application Example 57 157 3.40 209.5 Application Example 17 48 3.21 212.9 Application Example 58 162 3.17 214.6 Application Example 18 49 3.21 212.7 Application Example 59 164 3.20 213.8 Application Example 19 51 3.14 216.8 Application Example 60 168 3.55 202.3 Application Example 20 57 3.20 213.7 Application Example 61 169 3.53 203.1 Application Example 21 58 3.22 211.9 Application Example 62 172 3.50 204.7 Application Example 22 60 3.05 219.8 Application Example 63 174 3.53 203.5 Application Example 23 67 3.14 217.8 Application Example 64 176 3.58 200.9 Application Example 24 69 3.02 220.1 Application Example 65 177 3.51 204.1 Application Example 25 71 3.45 205.3 Application Example 66 178 3.53 203.7 Application Example 26 73 3.40 208.6 Application Example 67 179 3.38 210.4 Application Example 27 74 3.43 204.9 Application Example 68 181 3.50 204.2 Application Example 28 79 3.45 206.8 Application Example 69 183 3.55 202.9 Application Example 29 82 3.21 212.4 Application Example 70 185 3.52 201.8 Application Example 30 83 3.45 207.6 Application Example 71 187 3.48 205.4 Application Example 31 86 3.16 215.8 Application Example 72 188 3.39 209.3 Application Example 32 89 3.45 207.3 Application Example 73 190 3.40 208.7 Application Example 33 91 3.41 208.4 Application Example 74 193 3.50 203.5 Application Example 34 93 3.38 210.0 Application Example 75 195 3.36 210.2 Application Example 35 94 3.15 215.7 The luminous colors of application examples 1-75 are all green, and the x value ranges from 0.21 to 0.28 in the CIE color coordinates, and the y value ranges from 0.68 to 0.75.

[0061] It can be seen from the above table that the compounds of the present invention are applied to organic electroluminescent devices, under the same current density: 1) Compared with the control example using compound P1 (non-deuterated), the luminous efficiency of the device in the application example of the present invention has been greatly improved, the starting voltage of the device has been reduced, and the power consumption of the device has been relatively reduced; compared with the control examples using compounds P2, P3 and P5 (non-deuterated at the active site or insufficiently deuterated at the active site), the luminous efficiency of the device in the application example of the present invention has been improved to varying degrees; 2) Compared with the control example using compound P4 (deuterated positions cover the active site and are also deuterated at other positions), the luminous efficiency and power consumption of the device of the application example of the present invention are basically at the same level, but due to the reduction in the amount of deuterated benzene, the production cost can be significantly reduced, and the application in the industry has better economic efficiency; 3) Compared with the control example using compound P6 (amine groups with different structures), the luminous efficiency of the device in the application example of the present invention is improved, the starting voltage of the device is reduced, and the power consumption of the device is relatively reduced.

[0062] Next, the organic electroluminescent devices prepared in the control examples 1-6 and some application examples were further tested for luminescence lifetime to obtain the luminescence lifetime T97% data (the time when the luminescence brightness decreases to 97% of the initial brightness). The test equipment was the TEO luminescent device lifetime test system, and the test conditions were a current density of 10 mA / cm 2 The life span data of the P1 compound control example was used as a reference, and the results are shown in Table 5: Table 5 Test items Second hole transport layer compound T97% Test items Second hole transport layer compound T97% Comparative Example 1 P1 100% Application Example 28 79 135% Comparative Example 2 P2 120% Application Example 29 82 136% Comparative Example 3 P3 109% Application Example 30 83 134% Comparative Example 4 P4 128% Application Example 35 94 135% Comparative Example 5 P5 102% Application Example 39 108 131% Comparative Example 6 P6 119% Application Example 47 130 134% Application Example 1 1 141% Application Example 51 143 144% Application Example 4 4 143% Application Example 52 148 137% Application Example 5 12 138% Application Example 53 149 138% Application Example 6 13 135% Application Example 54 152 140% Application Example 7 16 138% Application Example 60 168 150% Application Example 15 38 130% Application Example 69 183 148% Application Example 16 43 133% Application Example 75 193 146% Application Example 27 74 143% It can be seen from the above table that, compared with the control examples, when the compounds of the present invention are applied to organic electroluminescent devices, the service life of the devices is improved to varying degrees at the same current density.

[0063] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A compound, characterized in that It has a structure as shown in formula (I): （I） In the above formula: Ar1 and Ar2 each independently represent different groups, and one of the groups is dimethylfluorene, and the other group is a substituted or unsubstituted C6-C30 aryl group or C6-C30 heteroaryl group; the substituent of the C6-C30 aryl group is selected from one or more of an alkyl group, a deuterated alkyl group, a phenyl group, a phenyl group substituted by an alkyl group, and a phenyl group substituted by a deuterated alkyl group; the substituent of the C6-C30 heteroaryl group is selected from a deuterated or undeuterated C6-C20 aryl group; (D) m represents m deuterium substituents connected to the benzene ring, and m represents an integer of 1 to 5; (D)n represents n deuterium substituents connected to the benzene ring, and n represents an integer of 1-4.

2. The compound according to claim 1, characterized in that: One of Ar1 and Ar2 is dimethylfluorene, and the other is selected from a diphenyl group, a terphenyl group, a diphenyl group substituted with a methyl group or a phenyl group, and a diphenyl group substituted with a deuterated methyl group.

3. The compound according to claim 1, characterized in that: One of Ar1 and Ar2 is dimethylfluorene, and the other is selected from substituted or unsubstituted oxafluorene groups, wherein the substituent of the oxafluorene group is phenyl or deuterated phenyl.

4. The compound according to claim 1, characterized in that: The value of m is 5 and the value of n is 4.

5. The compound according to claim 1, characterized in that: One of Ar1 and Ar2 is selected from the group represented by any one of the structural formulas from Formula (1-1) to Formula (1-5), and the other is selected from the group represented by any one of the structural formulas from Formula (2-1) to Formula (2-4): ； in: R1 and R2 are the same or different and represent phenyl, methyl or deuterated methyl, and R3 and R4 are the same or different and represent phenyl or deuterated phenyl; i, j, p, and q each independently represent an integer of 0 or 1; X represents O or S; * indicates the attachment site.

6. The compound according to claim 1, characterized in that Formula (I) is represented by formula (I-1) or (I-2): ; in: R1 and R2 are the same or different and represent phenyl, methyl or deuterated methyl; R3 and R4 are the same or different and represent phenyl or deuterated phenyl; i, j, p, and q each independently represent an integer of 0 or 1; and X represents O or S.

7. The compound according to claim 1, characterized in that One of the following compounds: 。 8. An organic electroluminescent device, characterized in that: The invention comprises a first electrode, a second electrode and an organic layer formed therebetween, wherein the organic layer contains the compound according to any one of claims 1 to 7.

9. The organic electroluminescent device according to claim 8, characterized in that: The organic layer comprises 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, wherein the first hole transport layer or the second hole transport layer contains the compound according to any one of claims 1 to 7.

10. A display device, characterized in that: Comprising the organic electroluminescent device as claimed in claim 8 or 9.

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