CN110669051A

CN110669051A - Compound, display panel and display device

Info

Publication number: CN110669051A
Application number: CN201910939930.6A
Authority: CN
Inventors: 肖文静; 高威; 代文朋; 张磊; 牛晶华; 安平
Original assignee: Shanghai Tianma AM OLED Co Ltd
Current assignee: Tianma Microelectronics Co Ltd; Shanghai Tianma AM OLED Co Ltd
Priority date: 2019-09-30
Filing date: 2019-09-30
Publication date: 2020-01-10

Abstract

The present invention relates to the field of OLED technology and provides a compound having TADF properties, which has a structure of formula (1): a. the₁And A₂Represents an electron-accepting group such as a hydrogen atom, a phosphorus-oxygen-containing substituent, a sulfone substituent, an aryl boron substituent or the like; l is₁And L₂Each independently selected from the group consisting of a single bond, phenylene, thienylene, naphthylene, anthracenylene, phenanthrenylene, pyrenylene; ar (Ar)₁And Ar₂Each independently selected from hydrogen atom, phenyl, thienyl, naphthyl, anthryl, phenanthryl, pyrenyl, phosphorus-oxygen-containing substituent, sulfone substituent, aryl boron substituent and the like. The condensed carbazole structure of the compound has strong electron donating capability and thermal stability. When the condensed carbazole structure acts as an electron donorWhen the bipolar main body material formed by combining the body with a proper acceptor material is applied to the light-emitting layer, good energy transfer can be realized between the bipolar main body material and the doping body, so that the light-emitting efficiency of the device is improved.

Description

Compound, display panel and display device

Technical Field

The invention relates to the technical field of organic electroluminescent materials, in particular to a compound with TADF (TADF) property, a display panel comprising the compound and a display device comprising the compound.

Background

With the development of electronic display technology, Organic Light Emitting Devices (OLEDs) are widely used in various display devices, and research and application of light emitting materials of the OLEDs are increasing.

The materials used for the light-emitting layer of an OLED mainly include the following four types according to the light-emitting mechanism:

(1) a fluorescent material; (2) a phosphorescent material; (3) triplet-triplet annihilation (TTA) material 0; (4) thermally Activated Delayed Fluorescence (TADF) material.

For fluorescent materials, the ratio of singlet to triplet excitons in excitons is 1:3 based on spin statistics, so that the maximum internal quantum yield of the fluorescent material does not exceed 25%. According to the lambertian emission mode, the light extraction efficiency is around 20%, so the External Quantum Effect (EQE) of the OLED based on fluorescent materials does not exceed 5%.

For the phosphorescent material, the phosphorescent material can enhance the intersystem crossing inside molecules through the spin coupling effect due to the heavy atom effect, and can directly utilize 75% of triplet excitons, so that the emission with the participation of S1 and T1 together at room temperature is realized, and the theoretical maximum internal quantum yield can reach 100%. According to the lambertian emission pattern, the light extraction efficiency is about 20%, so that the external quantum effect of OLEDs based on phosphorescent materials can reach 20%. However, the phosphorescent material is basically a heavy metal complex such as Ir, Pt, Os, Re, Ru and the like, and the production cost is high, so that the large-scale production is not facilitated. Under high current density, the phosphorescent material has serious efficiency roll-off phenomenon, and the stability of the phosphorescent device is not good.

For triplet-triplet annihilation (TTA) materials, two adjacent triplet excitons recombine to generate a higher energy singlet excited state molecule and a ground state molecule, but two triplet excitons generate a singlet exciton, so the theoretical maximum internal quantum yield can only reach 62.5%. In order to prevent the generation of the large efficiency roll-off phenomenon, the concentration of triplet excitons needs to be regulated during this process.

For a Thermally Activated Delayed Fluorescence (TADF) material, when the difference between the singlet excited state and the triplet excited state is small, reverse intersystem crossing (RISC) occurs inside the molecule, T1 state excitons are up-converted to S1 state by absorbing environmental heat, 75% of triplet excitons and 25% of singlet excitons can be simultaneously utilized, and the theoretical maximum internal quantum yield can reach 100%. The TADF material is mainly an organic compound, does not need rare metal elements and has low production cost. TADF materials can be chemically modified by a variety of methods. However, the TADF materials found so far are relatively few, and therefore, there is a need to develop new TADF materials that can be used in OLEDs.

Disclosure of Invention

In view of the above, the present invention provides a compound having a Thermally Activated Delayed Fluorescence (TADF) property, the compound having a structure represented by formula (1):

A₁and A₂Represents an electron-accepting group, and A₁And A₂Each independently selected from hydrogen atom, carbonyl group-containing substituent, imide substituent, phosphorus-oxygen-containing substituent, fluorine-containing substituent, sulfone substituent, aryl boron substituent and cyanogen-containing substituent;

L₁and L₂Each independently selected from the group consisting of a single bond, phenylene, thienylene, naphthylene, anthracenylene, phenanthrenylene, pyrenylene;

Ar₁and Ar₂Each independently selected from hydrogen atom, phenyl, thienyl, naphthyl, anthryl, phenanthryl, pyrenyl, carbonyl-containing substituent, imide substituent, phosphorus-oxygen-containing substituent, fluorine-containing substituent, sulfone substituent, aryl boron substituent and cyano-containing substituentA substituent group.

The structure of the condensed carbazole is similar to that of carbazole, and has strong electron donating capability and thermal stability. In addition, because the benzene rings are fused with two five-membered rings containing nitrogen atoms, a certain dihedral angle is formed between the two benzene rings of the fused carbazole, and the non-planar structure inhibits luminescence quenching caused by intermolecular stacking. On the other hand, under the action of condensed rings, the condensed carbazole core controls the torsion angle in a small range, namely certain 'planarity' is maintained, and the structure is favorable for intermolecular charge transfer and improves the carrier mobility of the whole molecule. Therefore, when the fused carbazole is used as a donor and combined with a proper acceptor material to form a bipolar host material to be applied to a light-emitting layer, good energy transfer can be realized between the bipolar host material and a dopant, so that the light-emitting efficiency of the device is improved.

Drawings

FIG. 1 is a general structure of a compound provided by an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of an OLED provided in an embodiment of the present invention;

fig. 3 is a schematic diagram of a display device according to an embodiment of the present invention.

Detailed Description

The present invention is further illustrated by the following examples and comparative examples, which are intended to be illustrative only and are not to be construed as limiting the invention.

One aspect of the present invention provides a compound having a structure represented by formula (1):

Ar₁and Ar₂Each independently selected from hydrogen atom, phenyl, thienyl, naphthyl, anthryl, phenanthryl, pyrenyl, carbonyl-containing substituent, imide substituent, phosphorus-oxygen-containing substituent, fluorine-containing substituent, sulfone substituent, aryl boron substituent and cyanogen-containing substituent.

According to one embodiment of the compounds of the invention, L₁And L₂Selected from phenylene.

According to one embodiment of the compounds of the invention, Ar₁And Ar₂Selected from hydrogen atoms.

According to one embodiment of the compounds of the invention, L₁And L₂Is phenylene, A₁And A₂Is a hydrogen atom.

According to one embodiment of the compounds of the invention, L₁And L₂Selected from the same group, A₁And A₂Are selected from the same group, and Ar₁And Ar₂Selected from the same group.

According to one embodiment of the compounds of the invention, L₁And L₂Selected from phenylene, Ar₁And Ar₂Each independently selected from carbonyl group-containing substituent, imide substituent, phosphorus-containing oxygen substituent, fluorine-containing substituent, sulfone substituent, aryl boron substituent and cyanogen-containing substituent.

According to one embodiment of the compound of the present invention, the compound has any one of the structures represented by formula (2), formula (3) and formula (4):

wherein Ar is₁、Ar₂And Ar₃Are respectively selected from one of phosphorus-oxygen-containing substituent groups, sulfone substituent groups and aryl boron substituent groups.

According to one embodiment of the compound of the present invention, the carbonyl-containing substituent is selected from one of the following groups:

wherein # represents a position capable of linking to formula (1), formula (2), formula (3) or formula (4), and R represents a C1-C20 alkyl group, a C1-C20 alkoxy group, a C2-C20 alkenyl group, a C2-C20 alkynyl group, a C4-C8 cycloalkyl group, a C6-C40 aryl group, a C4-C40 heteroaryl group.

According to one embodiment of the compound of the present invention, the imide-based substituent is selected from one of the following groups:

According to one embodiment of the compound of the present invention, the phosphorus-containing oxy substituent is selected from one of the following groups:

x is selected from O, S, -BR₄₁、-C(R₄₁)₂、-Si(R₄₁)₂and-NR₄₁Any one of the above;

R₃₀、R₃₁、R₃₂、R₃₃、R₃₄、R₃₅、R₃₆、R₃₇、R₃₈、R₃₉、R₄₀、R₄₁each independently selected from a hydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C3-C20 heterocyclic group, a substituted or unsubstituted C6-C40 aryl group, a substituted or unsubstituted C2 alkyl group-any one of C40 heteroaryl;

# represents a position at which the compound represented by formula (1), formula (2), formula (3) or formula (4) can be linked.

According to one embodiment of the compound of the present invention, the fluorine-containing substituent is selected from one of the following groups:

According to an embodiment of the compound of the present invention, the sulfone substituent is selected from one of the following groups:

According to one embodiment of the compound of the present invention, the aryl boron type substituent is selected from one of the following groups:

R₁₅-R₂₃each independently selected from alkyl, alkoxy, phenyl, aryl or heteroaryl; x₁Selected from the group consisting of boron, oxygen, sulfur, nitrogen, when X₁When it is an oxygen atom or a sulfur atom, R₂₃Is absent;

# represents the position to which formula (1), formula (2), formula (3) or formula (4) is linked.

According to one embodiment of the compound of the present invention, the cyano-containing substituent is selected from one of the following groups:

wherein # represents a position at which formula (1), (2), (3) or (4) can be linked. .

According to one embodiment of the compound of the present invention, the compound is selected from the following compounds:

according to one embodiment of the compounds of the present invention, the energy level difference Δ E between the lowest singlet energy level S1 and the lowest triplet energy level T1 of the compound_ST＝E_S1-E_T1≦0.30eV。

The compound has TADF (thermo-activated functional) characteristics, and can be used as a host material or a guest material of an OLED light-emitting layer.

The present invention also provides methods for preparing exemplary compounds P1, P2, P4, P5, P13, P14, P16, P17, P22, P27, P30, P31, P32, P33, as described in exemplary synthetic examples 1 to 14 below.

Example 1

Synthesis of Compound P1

S2(1mmol) and S18(2mmol) were dissolved in toluene solvent under nitrogen blanket, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P1(0.88mmol, 88%) as a solid.

MALDI-TOF MS：C₄₈H₃₀B₂N₂O₂Calculated m/z: 688.39, respectively; measurement values: 688.25.

elemental analysis results: c, 83.75; h, 4.39; b, 3.14; n, 4.07; o, 4.65; measurement values: c, 83.65; h, 4.49; b, 3.24; n, 4.05; and O, 4.57.

Example 2

Synthesis of Compound P2

S1(1mmol) was dissolved in o-dichlorobenzene as solvent under nitrogen protection, PPh was added₃Heating to reflux, and reacting for 8 h. After the reaction was completed, the reaction mixture was cooled to room temperature, and all the solvent was removed by distillation under the reduced pressure to collect a crude product. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane: chloroform (5:1) as an eluent to finally purify S2(0.92mmol, 92%) as a solid.

MALDI-TOF MS：C₁₂H₈N₂Calculated m/z: 180.21, respectively; measurement values: 180.07.

s2(1mmol) and S3(2mmol) were dissolved in toluene solvent under nitrogen blanket, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. Purifying the crude product with silica gel chromatography column using n-hexaneChloroform (5:1) as eluent, and finally purified to obtain P2(0.88mmol, 88%) as a solid.

MALDI-TOF MS：C₄₈H₃₄N₂O₂P₂Calculated m/z: 732.74, respectively; measurement values: 732.21.

elemental analysis results: c, 78.68; h, 4.68; n, 3.82; o, 4.37; p, 8.45; measurement values: c, 78.66; h, 4.71; n, 3.80; o, 4.39; p, 8.44.

Example 3

Synthesis of Compound P4

S2(1mmol) and S19(2mmol) were dissolved in toluene solvent under nitrogen blanket, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P4(0.88mmol, 88%) as a solid.

MALDI-TOF MS：C₄₈H₂₈N₂O₄S₂Calculated m/z: 760.88, respectively; measurement values: 760.15.

elemental analysis results: c, 75.77; h, 3.71; n, 3.68; o, 8.41; s, 8.43; measurement values: c, 75.67; h, 3.76; n, 3.71; o, 8.37; s, 8.49.

Example 4

Synthesis of Compound P5

S2(1mmol) and S20(2mmol) were dissolved in toluene solvent under nitrogen blanket, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to obtain P5(0.88mmol, 88%)。

MALDI-TOF MS：C₄₀H₂₀N₆Calculated m/z: 584.63, respectively; measurement values: 584.17.

elemental analysis results: c, 82.18; h, 3.45; n, 14.38; measurement values: c, 82.25; h, 3.55; n, 14.20.

Example 5

Synthesis of Compound P13

S4(1mmol) was dissolved in o-dichlorobenzene solvent under nitrogen protection, PPh3 was added, heated to reflux, and reacted for 8 h. After the reaction was completed, the reaction mixture was cooled to room temperature, and all the solvent was removed by distillation under the reduced pressure to collect a crude product. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane: chloroform (5:1) as an eluent to finally purify S5(0.92mmol, 92%) as a solid.

MALDI-TOF MS：C₁₈H₂₄N₂Si₂Calculated m/z: 324.57, respectively; measurement values: 324.15.

s5(1mmol) and S6(2mmol) were dissolved in toluene solvent under nitrogen blanket, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane: chloroform (5:1) as an eluent to finally purify S7(0.88mmol, 88%) as a solid.

MALDI-TOF MS：C₃₀H₃₂N₂Si₂Calculated m/z: 476.76, respectively; measurement values: 476.21.

s7(1mmol) and NBS (3mmol) were dissolved in dichloromethane under nitrogen and stirred at room temperature for 12 h. After the reaction was completed, all the solvent was distilled off under reduced pressure, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify S8(0.97mmol, 97%) as a solid.

MALDI-TOF MS：C₂₄H₁₄Br₂N₂Calculated m/z: 490.19, respectively; measurement values: 489.95.

s8(1mmol) and S9(2mmol) were dissolved in toluene solvent under nitrogen blanket, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P13(0.88mmol, 88%) as a solid.

MALDI-TOF MS：C₄₈H₂₆N₄O₄Calculated m/z: 722.74, respectively; measurement values: 722.20.

elemental analysis results: c, 79.77; h, 3.63; n, 7.75; o, 8.85; measurement values: c, 79.12; h, 3.59; n, 7.63; and O, 9.66.

Example 6

Synthesis of Compound P14

S8(1mmol) and S21(2mmol) were dissolved in toluene solvent under nitrogen blanket, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P14(0.88mmol, 88%) as a solid.

MALDI-TOF MS：C₆₀H₄₂N₂O₂P₂Calculated m/z: 884.94, respectively; measuringMagnitude: 884.27.

elemental analysis results: c, 81.43; h, 4.78; n, 3.17; o, 3.62; p, 7.00; measurement values: c, 81.45; h, 4.77; n, 3.21; o, 3.65; p, 6.92.

Example 7

Synthesis of Compound P16

S2(1mmol), S6(1mmol) and S10(1mmol) were dissolved in toluene solvent under nitrogen protection, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P16(0.68mmol, 68%) as a solid.

MALDI-TOF MS：C₃₉H₂₅N₅Calculated m/z: 563.65, respectively; measurement values: 563.21. elemental analysis results: c, 83.10; h, 4.47; n, 12.43; measurement values: c, 83.06; h, 4.49; n, 12.45.

Example 8

Synthesis of Compound P17

S2(1mmol), S6(1mmol) and S11(1mmol) were dissolved in toluene solvent under nitrogen protection, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P17(0.68mmol, 68%) as a solid.

MALDI-TOF MS：C₃₉H₂₅N₅Calculated m/z: 563.65, respectively; measurement values: 563.21.

elemental analysis results: c, 83.10; h, 4.47; n, 12.43; measurement values: c, 83.06; h, 4.49; n, 12.45.

Example 9

Synthesis of Compound P22

S2(1mmol), S6(1mmol) and S25(1mmol) were dissolved in toluene solvent under nitrogen protection, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P22(0.68mmol, 68%) as a solid.

MALDI-TOF MS：C₃₆H₂₅N₂Calculated OP, m/z: 532.57, respectively; measurement values: 532.17.

elemental analysis results: c, 81.19; h, 4.73; n, 5.26; o, 3.00; p, 5.82; measurement values: c, 81.17; h, 4.70; n, 5.31; o, 3.03; p, 5.79.

Example 10

Synthesis of Compound P27

S12(1mmol) was dissolved in o-dichlorobenzene solvent under nitrogen protection, PPh3 was added, heated to reflux, and reacted for 8 h. After the reaction was completed, the reaction mixture was cooled to room temperature, and all the solvent was removed by distillation under the reduced pressure to collect a crude product. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane: chloroform (5:1) as an eluent to finally purify S13(0.92mmol, 92%) as a solid.

MALDI-TOF MS：C₁₅H₁₆N₂Si, calculated m/z: 252.39, respectively; measurement values: 252.11.

s13(1mmol) and S6(2mmol) were dissolved in toluene solvent under nitrogen protection, and Pd (PPh) was added₃)₄At 120 ℃ CRefluxing for 6h under the condition. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane: chloroform (5:1) as an eluent to finally purify S14(0.68mmol, 68%) as a solid.

MALDI-TOF MS：C₂₇H₂₄N₂Si, calculated m/z: 404.58, respectively; measurement values: 404.17.

s14(1mmol) and NBS (3mmol) were dissolved in dichloromethane under nitrogen and stirred at room temperature for 12 h. After the reaction was completed, all the solvent was distilled off under reduced pressure, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify S15(0.97mmol, 97%) as a solid.

MALDI-TOF MS：C₂₄H₁₅BrN₂Calculated m/z: 411.29, respectively; measurement values: 410.04.

dissolving S15(1mmol) and S16(1mmol) in 1, 4-dioxane solvent under nitrogen protection, and adding Pd (PPh)₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P27(0.68mmol, 68%) as a solid.

MALDI-TOF MS：C₃₇H₂₂N₂O₃S, calculated value of m/z: 574.65, mol.wt.: 574.65; measurement values: 574.14.

elemental analysis results: c, 77.33; h, 3.86; n, 4.87; o, 8.35; s, 5.58; measurement values: c, 77.30; h, 3.89; n, 4.86; o, 8.37; and S, 5.58.

Example 11

Synthesis of Compound P30

S15(1mmol) and S17(1mmol) were dissolved in dioxane solvent under nitrogen protection, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P30(0.68mmol, 68%) as a solid.

MALDI-TOF MS：C₄₂H₂₇BN₂Calculated m/z: 570.49, respectively; measurement values: 570.23.

elemental analysis results: c, 88.42; h, 4.77; b, 1.90; n, 4.91; measurement values: c, 88.40; h, 4.79; b, 1.91; and N, 4.90.

Example 12

Synthesis of Compound P31

S8(1mmol) and S22(2mmol) were dissolved in toluene solvent under nitrogen blanket, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P31(0.88mmol, 88%) as a solid.

MALDI-TOF MS：C₄₈H₃₂N₂O₄S₂Calculated m/z: 764.91, respectively; measurement values: 764.18.

elemental analysis results: c, 75.37; h, 4.22; n, 3.66; o, 8.37; s,8.38 measurement: c, 75.34; h, 4.25; n, 3.69; o, 8.39; s, 8.33.

Example 13

Synthesis of Compound P32

S8(1mmol) and S23(2mmol) were dissolved in toluene solvent under nitrogen blanket, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P32(0.88mmol, 88%) as a solid.

MALDI-TOF MS：C₇₂H₄₆B₂N₂O₂Calculated m/z: 992.77, respectively; measurement values: 992.37.

elemental analysis results: c, 87.11; h, 4.67; b, 2.18; n, 2.82; o,3.22 measurement: c, 87.14; h, 4.63; b, 2.15; n, 2.87; and O, 3.21.

Example 14

Synthesis of Compound P33

S8(1mmol) and S24(2mmol) were dissolved in toluene solvent under nitrogen blanket, and Pd (PPh) was added₃)₄And refluxing for 6h at 120 ℃. After the reaction was completed, it was cooled to room temperature, and the crude product was collected. The crude product was purified by silica gel chromatography using a mixed solvent of n-hexane and chloroform (5:1) as an eluent to finally purify P33(0.88mmol, 88%) as a solid.

MALDI-TOF MS：C₅₄H₂₆N₈Calculated m/z: 786.84, respectively; measurement values: 786.23.

elemental analysis results: c, 82.43; h, 3.33; n,14.24 measurements: c, 82.47; h, 3.30; n, 14.23.

Parameter characterization of exemplary Compounds

Table 1 lists the main parameters of exemplary compounds P2, P13, P16, P17, P27, P30.

TABLE 1

Note that S1 represents the singlet energy level, T1 represents the triplet energy level, △ E_STRepresenting the difference between singlet and triplet energy levels, E_gIndicating the HOMO-LUMO energy level difference.

As can be seen from Table 1, the compound of the present invention has high singlet and triplet energy levels, and the HOMO energy level and LUMO energy level are in proper positions, can be well matched with a general electron transport layer material or a hole transport layer material, and is suitable for being used as a host material of a light emitting layer.

The invention also provides a display panel which comprises an organic light-emitting device, wherein the organic light-emitting device comprises an anode, a cathode and a light-emitting layer positioned between the anode and the cathode which are oppositely arranged, and the light-emitting material of the light-emitting layer comprises one or more compounds disclosed by the invention.

In one embodiment of the display panel provided by the present invention, the light-emitting material of the light-emitting layer includes a host material and a guest material, the host material is selected from one or more compounds described in the present invention, and the guest material is selected from a fluorescent material, a thermally activated delayed fluorescent material, or a phosphorescent light-emitting material.

In one embodiment of the display panel provided by the present invention, the light emitting layer includes a host material and a guest material, the host material is selected from 2, 8-bis (diphenylphosphino) dibenzothiophene, 4' -bis (9-carbazole) biphenyl, 3' -bis (N-carbazolyl) -1,1' -biphenyl, 2, 8-bis (diphenylphosphinoxy) dibenzofuran, bis (4- (9H-carbazolyl-9-yl) phenyl) diphenylsilane, 9- (4-tert-butylphenyl) -3, 6-bis (triphenylsilyl) -9H-carbazole, bis (2-diphenylphosphino) diphenyl ether, 1, 3-bis [3, 5-bis (pyridin-3-yl) phenyl ] benzene, and a guest material, Any one or more of 4, 6-bis (3, 5-bis (3-pyridinylphenyl) -2-methylpyrimidine, 9- (3- (9H-carbazolyl-9-yl) phenyl) -9H-carbazole-3-cyano, 9-phenyl-9- [4- (triphenylsilyl) phenyl ] -9H-fluorene, 1,3, 5-tris (1-phenyl-1H-benzimidazol-2-yl) benzene, diphenyl [4- (triphenylsilyl) phenyl ] phosphine oxide, 4' -tris (carbazol-9-yl) triphenylamine, 2, 6-dicarbazole-1, 5-pyridine, polyvinylcarbazole and polyfluorene, the guest material is selected from one or more of the compounds described in the present invention.

According to one embodiment of the display panel of the present invention, the organic light emitting device further includes one or more of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, or an electron injection layer.

The hole injection material, hole transport material and electron blocking material may be selected from 2,2 '-dimethyl-N, N' -di-1-naphthyl-N, N '-diphenyl [1,1' -biphenyl]-4,4 '-diamine (. alpha. -NPD), 4' -tris (carbazol-9-yl) triphenylamine (TCTA), 1, 3-dicarbazolyl-9-ylbenzene (mCP), 4 '-bis (9-Carbazolyl) Biphenyl (CBP), 3' -bis (N-carbazolyl) -1,1 '-biphenyl (mCBP), 2,3,6,7,10, 11-hexacyano-1, 4,5,8,9, 12-Hexaazatriphenylene (HATCN), 4' -cyclohexylbis [ N, N-bis (4-methylphenyl) aniline (TAPC), N '-diphenyl-N, N' - (1-naphthyl) -1,1 '-biphenyl-4, 4' -diamine (. alpha. -NPB), N, N ' -bis (naphthalen-2-yl) -N, N ' -bis (phenyl) biphenyl-4, 4' -diamine (NPB), poly (3, 4-ethylenedioxythiophene) -polystyrenesulfonic acid (PEDOT: PSS), Polyvinylcarbazole (PVK), 9-phenyl-3, 9-bicarbazole (CCP), molybdenum trioxide (MoO)₃) And the like, but not limited to the above materials.

The hole blocking material, the electron transporting material, and the electron injecting material may be selected from 2, 8-bis (diphenylphosphino) dibenzothiophene (PPT), TSPO1, 1,3, 5-tris (1-phenyl-1H-benzimidazol-2-yl) benzene (TPBi), 2, 8-bis (diphenylphosphinoxy) dibenzofuran (PPF), bis (2-diphenylphosphino) diphenyl ether (DPEPO), lithium fluoride (LiF), 4, 6-bis (3, 5-bis (3-pyridyl) ylphenyl) -2-methylpyrimidine (B3PYMPM), 4, 7-diphenyl-1, 10-phenanthroline (Bphen), 1,3, 5-tris [ (3-pyridyl) -3-phenyl ] phenanthroline (Bphen)]Benzene (TmPyBP), tris [2,4, 6-trimethyl-3- (3-pyridyl) phenyl]Borane (3TPYMB), 1, 3-bis (3, 5-bipyridin-3-ylphenyl) benzene (B3PYPB), 1, 3-bis [3, 5-bis (pyridin-3-yl) phenyl]Benzene (BMPYPHB), 2,4, 6-tris (biphenyl-3-yl) -1,3, 5-triazine (T2T), diphenylbis [4- (pyridin-3-yl) phenyl]Silane (DPPS), cesium carbonate (Cs)₂O₃) Bis (2-methyl-8-hydroxyquinoline-N1, O8) - (1,1' -biphenyl-4-hydroxy) aluminum (BALq),8-Hydroxyquinoline-lithium (Liq) and tris (8-Hydroxyquinoline) aluminum (Alq)₃) And the like, but not limited to the above materials.

In the display panel provided by the present invention, the anode material of the organic light emitting device may be selected from metals such as copper, gold, silver, iron, chromium, nickel, manganese, palladium, platinum, and the like, and alloys thereof. The anode material may also be selected from metal oxides such as indium oxide, zinc oxide, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), and the like; the anode material may also be selected from conductive polymers such as polyaniline, polypyrrole, poly (3-methylthiophene), and the like. In addition, the anode material may be selected from materials that facilitate hole injection in addition to the listed anode materials and combinations thereof, including known materials suitable for use as anodes.

In the display panel provided by the present invention, the cathode material of the organic light emitting device may be selected from metals such as aluminum, magnesium, silver, indium, tin, titanium, and the like, and alloys thereof. The cathode material may also be selected from multi-layered metallic materials such as LiF/Al, LiO₂/Al、BaF₂Al, etc. In addition to the cathode materials listed above, the cathode materials can also be materials that facilitate electron injection and combinations thereof, including materials known to be suitable as cathodes.

The organic light emitting device may be fabricated according to a method well known in the art and will not be described in detail herein. In the present invention, the organic light emitting device can be fabricated by: an anode is formed on a transparent or opaque smooth substrate, an organic thin layer is formed on the anode, and a cathode is formed on the organic thin layer. The organic thin layer can be formed by a known film formation method such as evaporation, sputtering, spin coating, dipping, ion plating, or the like.

In one embodiment of the display panel according to the present invention, the structure of an Organic Light Emitting Device (OLED) is as shown in fig. 2. Wherein 1 is a substrate (substrate) made of glass or other suitable materials (such as plastics); 2 is a transparent anode such as ITO or IGZO; 3 is an organic film layer (including a luminescent layer); and 4, metal cathodes which jointly form a complete OLED device.

The following exemplary organic light emitting device examples are provided to illustrate the practical use of the compounds of the present invention as host materials for the light emitting layer of an organic light emitting device in an organic light emitting display panel.

Device example 1

The anode substrate having an ITO thin film with a film thickness of 100nm was ultrasonically cleaned with distilled water, acetone, and isopropanol, placed in an oven for drying, surface-treated by UV for 30 minutes, and then moved to a vacuum evaporation chamber. Under vacuum degree of 2X 10^-6Pa, each layer of thin film was evaporated, 5nm thick HATCN was evaporated to form a hole injection layer, 40nm thick N, N ' -diphenyl-N, N ' - (1-naphthyl) -1,1' -biphenyl-4, 4' -diamine (NPB) was evaporated, and 10nm thick 4,4',4 ″ -tris (carbazol-9-yl) triphenylamine (TCTA) was evaporated to form a Hole Transport Layer (HTL). On the hole transport layer, the object compound P2 of the present invention was used as a host material for a light-emitting layer, Ir (ppy)₃As a guest material of the light-emitting layer, the dopant material and the host material were simultaneously evaporated to form a light-emitting layer having a thickness of 30 nm. Then diphenyl [4- (triphenylsilyl) phenyl ] is evaporated on the luminescent layer]Phosphine oxide (TSPO1) formed a Hole Blocking Layer (HBL) 5nm thick. Evaporating 4, 7-diphenyl-1, 10-phenanthroline (Bphen) on the hole blocking layer to form an Electron Transport Layer (ETL) of 30 nm. LiF with the thickness of 2.5nm and Al with the thickness of 100nm are sequentially evaporated on the electron transport layer to be used as an Electron Injection Layer (EIL) and a cathode, so that the organic light-emitting display device is manufactured.

The organic electroluminescent device can also be prepared by adopting a solution processing method.

Device example 2

The difference from device example 1 was that compound P2 was replaced with compound P13, and the other preparation steps were the same as those in device example 1.

Device example 3

The difference from device example 1 was that compound P2 was replaced with compound P16, and the other preparation steps were the same as those in device example 1.

Device example 4

The difference from device example 1 was that compound P2 was replaced with compound P17, and the other preparation steps were the same as those in device example 1.

Device example 5

The difference from device example 1 was that compound P2 was replaced with compound P27, and the other preparation steps were the same as those in device example 1.

Device example 6

The difference from device example 1 was that compound P2 was replaced with compound P30, and the other preparation steps were the same as those in device example 1.

Comparative device example 1

The difference from device example 1 is that compound P2 was replaced by compound CBP and the other preparation steps were the same as the corresponding steps in device example 1.

TABLE 2 device Performance characterization

As can be seen from table 2, EQE of the organic light emitting device using P2, P13, P16, P17, P27, P30 as host materials, compared to comparative device 1 using the classical blue light emitting material CBP as phosphorescent host material_(max)The organic electroluminescent material is obviously higher than a contrast device, and the excellent hole and electron transport efficiency of the P2, P13, P16, P17, P27 and P30 bipolar host materials is mainly benefited, so that the driving voltage of the device is reduced, and the efficiency of the device is improved.

Although the present application has been described with reference to preferred embodiments, it is not intended to limit the scope of the claims, and many possible variations and modifications may be made by one skilled in the art without departing from the spirit of the application.

Claims

1. A compound having the structure shown in formula (1):

2. The compound of claim 1, wherein L is₁And L₂Selected from phenylene.

3. The compound of claim 2, wherein Ar is Ar₁And Ar₂Selected from hydrogen atoms.

4. The compound of claim 1, wherein L is₁And L₂Is phenylene, A₁And A₂Is a hydrogen atom.

5. The compound of claim 1, wherein L is₁And L₂Selected from the same group, A₁And A₂Are selected from the same group, and Ar₁And Ar₂Selected from the same group.

6. The compound of claim 4, wherein Ar is Ar₁And Ar₂Each independently selected from carbonyl group-containing substituentsThe substituent group comprises a group, an imide substituent group, a phosphorus-oxygen-containing substituent group, a fluorine-containing substituent group, a sulfone substituent group, an aryl boron substituent group and a cyanogen-containing substituent group.

7. The compound of claim 1, wherein the compound has any one of the structures represented by formula (2), formula (3), and formula (4):

8. The compound of any one of claims 1 to 7, wherein said carbonyl-containing substituent is selected from one of the following groups:

9. A compound according to any one of claims 1 to 7, characterised in that the imide-based substituent is selected from one of the following groups:

10. The compound of any one of claims 1 to 7, wherein the phosphorus-oxygen-containing substituent is selected from one of the following groups:

R₃₀、R₃₁、R₃₂、R₃₃、R₃₄、R₃₅、R₃₆、R₃₇、R₃₈、R₃₉、R₄₀、R₄₁each independently selected from any one of a hydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C3-C20 heterocyclic group, a substituted or unsubstituted C6-C40 aryl group and a substituted or unsubstituted C2-C40 heteroaryl group;

11. The compound of any one of claims 1 to 7, wherein said fluorine-containing substituent is selected from one of the following groups:

12. A compound according to any one of claims 1 to 7, wherein the sulfone substituent is selected from one of the following groups:

13. A compound according to any one of claims 1 to 7, characterised in that the arylboron-based substituent is selected from one of the following groups:

14. A compound according to any one of claims 1 to 7, characterised in that the arylboron-based substituent is selected from one of the following groups:

15. The compound of any one of claims 1 to 7, wherein the cyano-containing substituent is selected from one of the following groups:

wherein # represents a position at which formula (1), (2), (3) or (4) can be linked.

16. The compound of claim 1, wherein the compound is selected from the group consisting of:

17. the compound of any one of claims 1 to 16, wherein the energy level difference Δ Ε between the lowest singlet energy level S1 and the lowest triplet energy level T1 is the compound_ST＝E_S1-E_T1≦0.30eV。

18. A display panel comprising an organic light emitting device, wherein the organic light emitting device comprises an anode and a cathode oppositely arranged, and a light emitting layer between the anode and the cathode, wherein a light emitting material of the light emitting layer comprises one or more compounds of any one of claims 1 to 17.

19. The display panel according to claim 18, wherein the light-emitting material of the light-emitting layer comprises a host material and a guest material, and the guest material is one or more compounds according to any one of claims 1 to 17.

20. The display panel according to claim 18, wherein the light-emitting material of the light-emitting layer comprises a host material and a guest material, and the host material is one or more compounds according to any one of claims 1 to 17.

21. The display panel according to any one of claims 18 to 20, wherein the organic light-emitting device further comprises one or more of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, or an electron injection layer.

22. A display device comprising the display panel of any one of claims 18 to 21.