CN108997400B

CN108997400B - Aromatic compound and organic light-emitting display device

Info

Publication number: CN108997400B
Application number: CN201810844146.2A
Authority: CN
Inventors: 高威; 王湘成; 张磊; 牛晶华; 刘营; 邓东阳; 罗学强; 安平; 黄高军
Original assignee: Shanghai Tianma AM OLED Co Ltd
Current assignee: Wuhan Tianma Microelectronics Co Ltd
Priority date: 2018-07-27
Filing date: 2018-07-27
Publication date: 2021-09-07
Anticipated expiration: 2038-07-27
Also published as: CN108997400A

Abstract

The invention relates to an aromatic compound with Thermal Activation Delayed Fluorescence (TADF) performance, which has a structure shown in a formula (I), wherein D is an electron donor, and A is an electron acceptor; r₁₀And R₂₀Each is a cycloalkyl group; m, n are the number of electron donors D and electron acceptors A, respectively, which are linked to formula (I), D and e are substituents R, respectively₁₀And R₂₀F is the number of parent phenyl groups; f is 1 or 2; d and e are each 1 or 2; m and n are each 1, 2 or 3; when f is 1, m + n + d + e is less than or equal to 6, and when f is 2, m + n + d + e is less than or equal to 10. The aromatic compound has a light-emitting mechanism of thermal activation delayed fluorescence and high light-emitting efficiency. When the material is used as a light-emitting material, a light-emitting host material or a guest material in an organic light-emitting display device, the light-emitting efficiency of the organic light-emitting display device can be improved, and the advantages of low cost and longer service life are achieved. The invention also provides an organic light emitting display device.

Description

Aromatic compound and organic light-emitting display device

Technical Field

The invention relates to the field of organic electroluminescent materials, in particular to a cycloalkyl-containing aromatic compound material with a Thermal Activation Delayed Fluorescence (TADF) performance and an application of the material in an organic light-emitting display device.

Background

With the development of electronic display technology, OLEDs are widely used in various display devices, and research and application of OLED light emitting materials are increasing.

According to the light emitting mechanism, the following four materials can be used for the light emitting layer of the OLED:

(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 light emitting mode, the light extraction efficiency is about 20%, so the EQE of the OLED device based on the fluorescent material is not more than 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 light emitting mode, the light extraction efficiency is about 20%, so the EQE of the OLED device based on the phosphorescent material 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%. Mainly organic compounds, does not need rare metal elements and has low production cost. Chemical modification can be performed 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 OLED devices.

Disclosure of Invention

An object of the present invention is to provide an aromatic compound containing a cycloalkyl group, which has a Thermally Activated Delayed Fluorescence (TADF) property and is a novel electroluminescent material.

The aromatic compound containing the naphthenic base has a structure shown in a formula (I):

wherein D represents a chemical group as an electron donor, A represents a chemical group as an electron acceptor;

R₁₀and R₂₀Each is cycloalkyl and is independently selected from cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl;

m represents the number of electron donors D linked to formula (I), the individual electron donors D being identical or different; n represents the number of electron acceptors A linked in formula (I), each electron acceptor A being the same or different; d and e each represent a substituent R₁₀And R₂₀F represents the number of benzene rings in formula (I);

f is selected from 1 or 2; d and e are each independently 1 or 2; m, n are each independently selected from 1, 2 or 3, and when f is 1, m + n + d + e ≦ 6, and when f is 2, m + n + d + e ≦ 10.

In the present invention, a cycloalkyl group is introduced into a benzene ring nucleus, and the introduction of the cycloalkyl group has the following effects:

(1) compared with linear alkyl, the cycloalkyl has larger space volume and larger steric hindrance, can inhibit the molecular rotation between the donor unit and the acceptor unit, further improves the dihedral angle between the donor unit and the acceptor unit, and forms better space separation of HOMO energy level and LUMO energy level; resulting in a lower Δ E_STAnd a better TADF effect is formed, and the luminous efficiency is improved.

(2) The cycloalkyl has larger steric hindrance, and the introduction of the cycloalkyl with the large steric hindrance can inhibit the free rotation of a structural unit in a molecule, enhance the rigidity of the molecule, reduce the vibration in the whole molecule, effectively improve the color purity of the TADF material, and obtain a luminescent material with smaller FWHM and narrow emission.

(3) The introduction of the cycloalkyl can effectively improve the solubility of the material in a solvent, improve the solution-soluble processing type of the material, and further carry out solution methods such as ink-jet printing and the like to prepare large-area devices. The solution method has high material utilization rate, realizes large-size and batch R2R processing, and is easy to realize mass production processing.

Drawings

FIG. 1 is a general chemical formula of the aromatic compound having the heat-activated delayed fluorescence property of the present invention;

FIG. 2 is a HOMO energy level diagram of compound P1 according to the present invention;

FIG. 3 is a LUMO energy level diagram of compound P1 according to the present invention;

FIG. 4 is a schematic structural diagram of one embodiment of an organic light emitting device of the present invention;

fig. 5 is a schematic view of an embodiment of an organic light emitting display device of the present invention.

Detailed Description

The present invention is further illustrated by the following examples, which are intended to be illustrative only and are not to be construed as limiting the invention. The technical scheme of the invention is to be modified or replaced equivalently without departing from the scope of the technical scheme of the invention, and the technical scheme of the invention is covered by the protection scope of the invention.

One aspect of the present invention is to provide an aromatic compound having Thermally Activated Delayed Fluorescence (TADF) properties, the aromatic compound having a structure represented by formula (I):

According to an embodiment of the aromatic compound of the present invention, the electron donor D is selected from any one or more of the following groups:

wherein, Y, Y₁And Y₂Each independently selected from a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom or a silicon atom;

# denotes a position at which the linker of formula (I) can be attached;

x and y are each independently selected from 0,1, 2 or 3;

R₁、R₂、R₃、R₄each independently selected from hydrogen atom, C1-C20 alkyl, C1-C20 alkoxy, and substituted or unsubstituted C6-C40 aromatic hydrocarbonAny one of a substituted or unsubstituted C4-C40 heteroaryl, a substituted or unsubstituted C12-C40 carbazolyl group and a derivative group thereof, a substituted or unsubstituted C12-C40 diphenylamine group and a derivative group thereof, a substituted or unsubstituted C3-C40 azine group and a derivative group thereof, and a group shown in a formula (21);

when Y is an oxygen atom or a sulfur atom, R₃Is absent; when Y is₁When it is an oxygen atom or a sulfur atom, R₃Is absent; when Y is₂When it is an oxygen atom or a sulfur atom, R₄Is absent;

wherein, in formula (21), Y₃Selected from carbon atom, nitrogen atom, oxygen atom, sulfur atom or silicon atom;

R₂₁、R₂₂、R₂₃each independently selected from any one of a hydrogen atom, a C1-C20 alkyl group, a C1-C20 alkoxy group, a substituted or unsubstituted C6-C40 aryl group and a substituted or unsubstituted C4-C40 heteroaryl group;

r, s are each independently selected from 0,1, 2 or 3; p is selected from 0,1 or 2; when Y is₃When is oxygen atom or sulfur atom, p is 0;

and # denotes the attachment position.

wherein, # denotes a position at which the compound of formula (I) can be bonded, and R denotes a C1-C20 alkyl group, a C1-C20 alkoxy group, a C2-C20 alkenyl group, a C2-C20 alkynyl group, a C6-C40 aryl group, or a C4-C40 heteroaryl group.

In this embodiment of the aromatic heterocyclic compound of the present invention, when the electron donor D is a carbazolyl group or a derivative group thereof, the following advantages are obtained: (1) the raw materials are cheap, and the cost is low; (2) the modification of molecular properties is easy to carry out on the basis of not changing the main skeleton structure of the molecule; (3) the nitrogen atom is easy to be functionally modified; (4) the carbazole group has a plurality of connecting positions which can be connected with other molecular structures; (5) the thermal stability and the chemical stability are good; (6) has a high triplet energy level; (7) has excellent electron donating ability, light emitting property and hole transporting property.

wherein Y is selected from a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom or a silicon atom;

# denotes a position at which the linker of formula (I) can be attached;

r, s are each independently selected from 0,1, 2 or 3; p and q are each independently selected from 0,1 or 2;

R₁、R₂、R₃、R₄each independently selected from any one of a hydrogen atom, a C1-C20 alkyl group, a C1-C20 alkoxy group, a substituted or unsubstituted C6-C40 aryl group, a substituted or unsubstituted C4-C40 heteroaryl group, a substituted or unsubstituted C12-C40 carbazolyl group and a derivative group thereof, a substituted or unsubstituted C12-C40 diphenylamine group and a derivative group thereof, a substituted or unsubstituted C3-C40 azine group and a derivative group thereof, and a group shown in a formula (21);

when Y is an oxygen atom or a sulfur atom, p is 0 or q is 0; when Y is a nitrogen atom, p and q are independently selected from 0 or 1; when Y is a carbon atom or a silicon atom, p and q are each independently selected from 0,1 or 2.

wherein # represents a position at which the linker of formula (I) can be attached.

In this embodiment of the heteroaromatic compound of the present invention, when the electron donor D is an acridine group and a derivative group thereof or a group similar to an acridine structure, there are the following advantages: (1) very strong electron-donating ability and shorter delayed fluorescence lifetime; (2) the HOMO and LUMO can be better separated; (3) the rigid molecular structure can effectively reduce the non-radiative decay of an excited state; (4) the rigid molecular structure reduces the free rotational vibration in molecules, is beneficial to improving the monochromaticity of the material and reducing the FWHM (full width at half maximum) of the material; (5) high triplet energy level.

# denotes the position of linkage to formula (I);

u, v are each independently selected from 0,1, 2 or 3;

R₁、R₂each independently selected from any one of a hydrogen atom, a C1-C20 alkyl group, a C1-C20 alkoxy group, a substituted or unsubstituted C6-C40 aryl group, a substituted or unsubstituted C4-C40 heteroaryl group, a substituted or unsubstituted C12-C40 carbazolyl group and a derivative group thereof, a substituted or unsubstituted C12-C40 diphenylamine group and a derivative group thereof, a substituted or unsubstituted C3-C40 azine group and a derivative group thereof, and a group shown in a formula (21).

In this embodiment of the heteroaromatic compound of the present invention, when the electron donor D is a diphenylamine group or a derivative thereof, the following advantages are obtained: (1) moderate electron donor characteristics; (2) good thermal stability and chemical stability, wide raw material source, low cost and easy chemical modification, and can effectively realize the spatial separation of HOMO and LUMO by combining with an electron acceptor.

wherein # represents a position at which the linker of formula (I) can be attached. These compounds also have good electron donor properties.

According to one embodiment of the aromatic compound of the present invention, the electron acceptor a is selected from one or more of a nitrogen-containing heterocyclic substituent, a cyano-containing substituent, a triarylboron substituent, a benzophenone substituent, an aromatic heterocyclic ketone substituent, and a sulfone substituent.

According to an embodiment of the aromatic compound of the present invention, the nitrogen-containing heterocyclic group substituent is selected from any one or more of the following groups:

wherein # represents a position capable of linking to formula (I);

r is selected from hydrogen atom, C1-C20 alkyl, C1-C20 alkoxy, C4-C8 cycloalkyl, C6-C40 aryl and C4-C40 heteroaryl.

According to an embodiment of the aromatic compound of the present invention, the cyano group-containing substituent is selected from any one or more of the following groups:

In the embodiment of the compound, the cyano substituent has strong electron-withdrawing capability, can effectively inhibit non-radiative transition, and can construct low delta E_STA TADF molecule of type D-A with high radiation transition rate constant kr.

According to an embodiment of the aromatic compound of the present invention, the triarylboron-based substituent is selected from any one or more of the following groups:

In the embodiment of the compound, due to the existence of an empty p orbit in the boron atom, when the boron atom is connected with an aromatic ring, a conjugated plane can be provided, and a substituent on the aromatic ring can protect the boron atom from being damaged by oxygen and water, so that the whole molecule has better optical performance, and can be used for synthesizing triaryl derivatives, and the obtained triaryl boron substituent can be used for constructing D-A type TADF materials.

According to an embodiment of the aromatic compound of the present invention, the benzophenone-based substituent and the heterocyclic benzophenone-based substituent are selected from any one or more of the following groups:

wherein # represents a position capable of linking with formula (I), and R in each structural formula independently represents C1-C20 alkyl, C1-C20 alkoxy, C2-C20 alkenyl, C2-C20 alkynyl, C4-C8 cycloalkyl, C6-C40 aryl, C4-C40 heteroaryl.

In bookIn this embodiment of the compounds of the invention, the benzophenone-based substituent or the heterocyclophenone-based substituent contains an electron-deficient carbonyl group (C ═ O), and the carbonyl group has a large twist angle with the benzene ring as an electron acceptor, so that intersystem crossing is very efficient (kscc ═ 10)¹¹·s^-1) The pure organic phosphor is very suitable for being used as an electron acceptor to construct D-A type TADF blue light molecules.

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

In the embodiment of the compound, when the sulfone substituent is used as an electron acceptor, the compound has good electron-withdrawing capability, presents a certain torsion angle at the center of the molecule so as to obtain a lower delta EST value, and can be used as the electron acceptor to construct a D-A type TADF molecule.

According to one embodiment of the aromatic compound of the present invention, the electron acceptor a is selected from one or more of the following groups:

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

according to a preferred embodiment of the aromatic compound according to the present invention, the electron donor D and the electron acceptor a are attached to the aromatic compound of formula (I) in ortho position to each other. Ortho-connection means that the electron donor D and the electron acceptor A are each connected to two adjacent carbon atoms in the compound of the formula (I). The use of ortho-ligation has the following advantages: (1) the effective separation of HOMO and LUMO is more favorably realized; (2) the electron donor D unit and the electron acceptor A unit are connected through the ortho position of the benzo five-membered heteroaromatic ring, so that the dihedral angle between the electron donor D unit and the electron acceptor A unit can be increased, the electron donor D unit and the electron acceptor A unit have larger steric hindrance, and smaller delta E is obtained_st(ii) a (3) The space restriction effect in the molecule is increased, the positive solvatochromic effect of the molecule can be reduced, the luminescent color purity of the molecule can be improved, and the lower half-peak width is realized.

According to one embodiment of the aromatic compound 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 aromatic compound_st＝E_S1-E_T10.30eV, preferably Δ E ≦_st＝E_S1-E_T1≦0.25eV。

Based on the thermal activation delayed fluorescence property of the compound, the compound can be used as a light-emitting material of a light-emitting layer in an organic light-emitting display device, or a host material of the light-emitting layer or a guest material of the light-emitting layer. Meanwhile, the compound of the present invention may be used as a red light emitting material, a green light emitting material, or a blue light emitting material of a light emitting layer in an organic light emitting display device. Accordingly, the present invention also provides an organic light emitting display device including the aromatic compound.

Since the light emitting mechanism of the compounds of the present invention is Thermally Activated Delayed Fluorescence (TADF), these compounds have high light emitting efficiency, and when they are applied to an organic light emitting display device, the light emitting efficiency of the organic light emitting display device can be improved. In addition, the TADF material is an organic compound, and has the advantage of lower cost compared with a phosphorescent metal complex.

In another aspect of the invention, several exemplary methods of preparing the aromatic compounds are provided. In the examples that follow, the synthesis of compounds P1, P5, P6 and P10 is described exemplarily.

Example 1

Synthesis of intermediate S2

To a 50mL single neck flask was added 20mL of concentrated sulfuric acid at room temperature followed by 6mL of bromobenzene S1(57mmol), stirred at room temperature for half an hour to give a white turbid liquid, then added 1.0g of mercaptosalicylic acid (6.5mmol) in portions over half an hour. Stirring at room temperature for 24h, then heating at 100 ℃ for 2-3h, cooling to room temperature, carefully pouring into ice water, filtering to obtain a solid, then adding 20% NaOH aqueous solution, stirring for 2h, filtering, washing with water to neutrality to obtain yellow solid S2(5.2mmol, 80%).

¹H NMR(400MHz,CDCl₃,ppm):7.70-7.90(s,2H),7.40-7.60(m,4H),7.30(m,1H)。MALDI-TOF MS:m/z calcd for C₁₃H₇BrOS:289.9；found:290.0

Synthesis of intermediate S3

At room temperature, 40mL of glacial acetic acid and 20mL of dichloromethane are added into a 50mL single-neck flask, the raw material intermediate S2(3mmol) and 5-fold equivalent of 30% hydrogen peroxide are added, the mixture is stirred at 55-60 ℃ for 20-24h, and after cooling to room temperature, dichloromethane is extracted and the mixture is subjected to column chromatography to obtain a white solid S3(2.6mmol, 85%).

MALDI-TOF MS:m/z calcd for C₁₃H₇BrO₃S:321.9；found:321.8

In a 250mL three-necked flask, S4(30mmol), pinacol diboron (36mmol), (1,1' -bis (diphenylphosphino) ferrocene) dichloropalladium (II) (0.3mmol) and potassium acetate (75mmol) were first added, followed by stirring and rapid repetition of 3 times of degassing and nitrogen substitution, and 100mL of tetrahydrofuran was added via syringe. Stirring at a certain rotating speed, and heating and refluxing the obtained mixed solution reactant at the reaction temperature of 80 ℃ for 5 hours; after the reaction was completed, it was cooled to room temperature and 100ml of water was added, extraction was performed with ether, the resulting organic phase was dried over anhydrous sodium sulfate, the solvent was distilled off, and purification was performed using column chromatography to obtain intermediate S5(21.6mmol, 72%).

MALDI-TOF MS:m/z calcd for C₂₂H₃₂BFO₂:358.2；found:358.5

Weighing compounds S3(10mmol), S5(10.2mmol) and [ Pd ] under nitrogen protection₂(dba)₃]·CHCl₃(0.2mmol) and HP (t-Bu)₃·BF₄(0.4mmol) was charged into a 100mL two-necked flask. 30mL of toluene (N was introduced into the flask in advance)₂Oxygen removal for 15 min), then 2mL of 1M K were added dropwise₂CO₃Aqueous solution (Advance N)₂15min deoxygenated), stirred at room temperature overnight. After the reaction was complete, 20mL of deionized water was added and a few drops of 2M HCl were added dropwise. Extracting with dichloromethane, collecting organic phase, and extracting with anhydrous Na₂SO₄And (5) drying. The dried solution was filtered and the solvent was removed using a rotary evaporator to give the crude product. The crude product was purified by silica gel chromatography to give S6 as a solid (6.4mmol, 64%).

MALDI-TOF MS:m/z calcd for C₂₉H₂₇FO₃S:474.2；found:474.6

Calculated values of elemental analysis: c, 73.39; h, 5.73; f, 4.00; o, 10.11; s, 6.76; test values are: c, 73.42; h, 5.75; f, 4.00; o, 10.09; and S, 6.74.

S6(10.0mmol), S7(10.5mmol), (dibenzylideneacetone) dipalladium (0) (0.05mmol), sodium tert-butoxide (14.0mmol), 4, 5-bis-diphenylphosphine-9, 9-dimethylxanthene (0.2mmol) were put in a 50mL three-necked flask, and while stirring, degassing and nitrogen substitution were rapidly repeated 3 times, and 20mL of toluene was added via a syringe. The mixture was heated to reflux under a stream of nitrogen for 3 hours. After the reaction, water was added to the reaction solution which was left to cool to room temperature, followed by extraction with dichloromethane and washing with a saturated saline solution. After the organic layer was dried over anhydrous sodium sulfate, the solvent was distilled off, and purification was performed by column chromatography to obtain P1(6.3mmol, 63%).

MALDI-TOF MS:m/z calcd for C₄₄H₄₁NO₃S:663.3；found:663.1

Calculated values of elemental analysis: c, 79.61; h, 6.22; n, 2.11; o, 7.23; s, 4.83; test values are: c, 79.60; h, 6.22; n, 2.10; o, 7.26; and S, 4.82.

Example 2

S8(20mmol) is weighed under the protection of nitrogen, 60mL of acetic acid is added, 24mmol of liquid bromine is dropwise added under the condition of stirring, and the obtained mixed solution is stirred for 5 hours at 80 ℃. With NaHSO₃The excess bromine was quenched with aqueous solution, extracted with dichloromethane (100 mL. times.3), the organic phase collected and dried over anhydrous Na₂SO₄And (5) drying. Filtration and removal of the solvent by distillation under reduced pressure using a rotary evaporator gave the crude product. Purifying the crude product by silica gel column chromatography gradient elution, and finally purifying by n-hexane recrystallization to obtain a solidPowder S9(16.8mmol, 84%).

MALDI-TOF MS:m/z calcd for C₁₂H₇BrS₂:293.9；found:293.8

At room temperature, 40mL of glacial acetic acid and 20mL of dichloromethane are added into a 50mL single-neck flask, the raw material intermediate S9(6mmol) and 5-fold equivalent of 30% hydrogen peroxide are added, the mixture is stirred at 55-60 ℃ for 20-24h, and after cooling to room temperature, dichloromethane is extracted and the mixture is subjected to column chromatography to obtain a white solid S10(5.1mmol, 85%).

MALDI-TOF MS:m/z calcd for C₁₂H₇BrO₄S₂:357.9；found:358.0

In a 250mL three-necked flask, S4(30mmol), pinacol diboron (36mmol), (1,1' -bis (diphenylphosphino) ferrocene) dichloropalladium (II) (0.3mmol) and potassium acetate (75mmol) were first added, followed by stirring and rapid repetition of 3 times of degassing and nitrogen substitution, and 100mL of tetrahydrofuran was added via syringe. Stirring at a certain rotating speed, and heating and refluxing the obtained mixed solution reactant at the reaction temperature of 80 ℃ for 5 hours; after the reaction was complete, it was cooled to room temperature and 100ml of water was added, extracted with ether, the resulting organic phase was dried over anhydrous sodium sulfate, the solvent was distilled off, and purified using column chromatography to give intermediate S5(20.4mmol, 68%).

MALDI-TOF MS:m/z calcd for C₂₄H₃₆BFO₂:386.3；found:386.4

Under the protection of nitrogen, weighing the compounds S10(8mmol), S12(10.2mmol) and [ Pd ]₂(dba)₃]·CHCl₃(0.2mmol) and HP (tBu)₃·BF₄(0.4mmol) was charged into a 100mL two-necked flask. 30mL of toluene (N was introduced into the flask in advance)₂Oxygen removal for 15 min), then 2mL of 1M K were added dropwise₂CO₃Aqueous solution (Advance N)₂15min deoxygenated), stirred at room temperature overnight. After the reaction was complete, 20mL of deionized water was added and a few drops of 2M HCl were added dropwise. Extracting with dichloromethane, collecting organic phase, and extracting with anhydrous Na₂SO₄And (5) drying. The dried solution was filtered and the solvent was removed using a rotary evaporator to give the crude product. The crude product was purified by silica gel chromatography to give S13 as a solid (5.6mmol, 70%).

MALDI-TOF MS:m/z calcd for C₃₀H₃₁FO₄S₂:538.2；found:538.5

Calculated values of elemental analysis: c, 66.89; h, 5.80; f, 3.53; o, 11.88; s, 11.90; test values are: c, 66.86; h, 5.81; f, 3.53; o, 11.90; and S, 11.90.

S13(10mmol), S7(10.5mmol), (dibenzylideneacetone) dipalladium (0) (0.05mmol), sodium tert-butoxide (14mmol), 4, 5-bis-diphenylphosphine-9, 9-dimethylxanthene (0.2mmol) were put in a 50mL three-necked flask, and degassing and nitrogen substitution were rapidly repeated 3 times while stirring, and 20mL of toluene was added via a syringe. The mixture was heated to reflux under a stream of nitrogen for 3 hours. After the reaction, water was added to the reaction solution which was left to cool to room temperature, followed by extraction with dichloromethane and washing with a saturated saline solution. After the organic layer was dried over anhydrous sodium sulfate, the solvent was distilled off, and purification was performed by column chromatography to obtain P5(6.4mmol, 64%).

MALDI-TOF MS:m/z calcd for C₄₅H₄₅NO₄S₂:727.3；found:727.8

Calculated values of elemental analysis: c, 74.24; h, 6.23; n, 1.92; o, 8.79; s, 8.81; test values are: c, 74.20; h, 6.24; n, 1.92; o, 8.82; s, 8.81.

Example 3

S13(8mmol), S7(10.5mmol), (dibenzylideneacetone) dipalladium (0) (0.05mmol), sodium tert-butoxide (14mmol), 4, 5-bis-diphenylphosphine-9, 9-dimethylxanthene (0.2mmol) were put in a 50mL three-necked flask, and degassing and nitrogen substitution were rapidly repeated 3 times while stirring, and 20mL of toluene was added via a syringe. The mixture was heated to reflux under a stream of nitrogen for 3 hours. After the reaction, water was added to the reaction solution which was left to cool to room temperature, followed by extraction with dichloromethane and washing with a saturated saline solution. After the organic layer was dried over anhydrous sodium sulfate, the solvent was distilled off, and the product was purified by column chromatography to obtain intermediate S14(5.3mmol, 66%).

MALDI-TOF MS:m/z calcd for C₃₃H₃₈BrN:527.2；found:527.5

In a 250mL three-necked flask, S14(30mmol), pinacol diboron (36mmol), (1,1' -bis (diphenylphosphino) ferrocene) dichloropalladium (II) (0.3mmol) and potassium acetate (75mmol) were first added, followed by stirring and rapid repetition of 3 times of degassing and nitrogen substitution, and 100mL of tetrahydrofuran was added via syringe. Stirring at a certain rotating speed, and heating and refluxing the obtained mixed solution reactant at the reaction temperature of 80 ℃ for 5 hours; after the reaction was completed, it was cooled to room temperature and 100ml of water was added, extraction was performed with diethyl ether, the resulting organic phase was dried over anhydrous sodium sulfate, the solvent was distilled off, and purification was performed using column chromatography to obtain intermediate S15(21.9mmol, 73%).

MALDI-TOF MS:m/z calcd for C₃₉H₅₀BNO₂:575.4；found:575.7.

Weighing the compounds S16(10mmol), S15(10.2mmol) and [ Pd ] under the protection of nitrogen₂(dba)₃]·CHCl₃(0.2mmol) and HP (tBu)₃·BF₄(0.4mmol) was charged into a 100mL two-necked flask. 30mL of toluene (N was introduced into the flask in advance)₂Oxygen removal for 15 min), then 2mL of 1M K were added dropwise₂CO₃Aqueous solution (Advance N)₂15min deoxygenated), stirred at room temperature overnight. After the reaction was complete, 20mL of deionized water was added and a few drops of 2M HCl were added dropwise. Extracting with dichloromethane, collecting organic phase, and extracting with anhydrous Na₂SO₄And (5) drying. The dried solution was filtered and the solvent was removed using a rotary evaporator to give the crude product. The crude product was purified by silica gel chromatography to give P6 as a solid (6.2mmol, 62%).

MALDI-TOF MS:m/z calcd for C₃₀H₃₁FO₄S₂:538.2；found:538.5

Example 4

S17(10.0mmol), S18(10.5mmol), (dibenzylideneacetone) dipalladium (0) (0.05mmol), sodium tert-butoxide (14.0mmol), 4, 5-bis-diphenylphosphine-9, 9-dimethylxanthene (0.2mmol) were put in a 50mL three-necked flask, and while stirring, degassing and nitrogen substitution were rapidly repeated 3 times, and 20mL of toluene was added via a syringe. The mixture was heated to reflux under a stream of nitrogen for 3 hours. After the reaction, water was added to the reaction solution which was left to cool to room temperature, followed by extraction with dichloromethane and washing with a saturated saline solution. After the organic layer was dried over anhydrous sodium sulfate, the solvent was distilled off, and the product was purified by column chromatography to obtain intermediate S19(6.0mmol, 60%).

MALDI-TOF MS:m/z calcd for C₃₀H₃₂BrN:485.2；found:485.6

Weighing S19(8mmol), putting into a 100mL two-neck flask, stirring while rapidly repeating degassing and nitrogen replacement for 3 times, adding 40mL dry ether to dissolve S20, dropwise adding n-BuLi solution (9.5mmol) at-78 ℃, continuously stirring for 15min, slowly heating to room temperature, stirring for 1h, cooling to-78 ℃ again, dropwise adding S24 ether solution (8.2mmol in 25mL), stirring for 30min, slowly heating to room temperature overnight, distilling under reduced pressure to remove volatile solvent, washing crude product (5 × 10mL) with methanol, and finally refining by column chromatography to obtain compound P10(4.9mmol, 62%).

MALDI-TOF MS:m/z calcd for C₄₈H₅₄BN:655.4；found:655.8

Calculated values of elemental analysis: c, 87.92; h, 8.30; b, 1.65; n, 2.14; test values are: c, 87.88; h, 8.32; b, 1.65; and N, 2.16.

Example 5

Optimizing and calculating the distribution condition of the molecular front track by applying a Density Functional Theory (DFT) and aiming at compounds P1-P10 under the calculation level of B3LYP/6-31G (d) by utilizing a Gaussian 09 program; meanwhile, based on the time-density functional theory (TDDFT), the singlet state energy level S of the molecule is calculated in a simulation mode₁And triplet state energy level T₁。

The data relating to examples P1 to P10 are shown in Table 1.

TABLE 1

In Table 1, S₁Represents a singlet energy level, T₁Represents the triplet energy level,. DELTA.E_STRepresenting singlet and triplet statesThe energy level difference, Eg, represents the HOMO-LUMO energy level difference.

Fig. 2 and 3 show the orbital arrangement of compound P1, wherein fig. 2 is the HOMO level profile of compound P1, and fig. 3 is the LUMO level profile of compound P1. As is evident from FIGS. 2 and 3, the arrangement of the HOMO and LUMO of compound P1 on different units, respectively, achieves a complete separation, which contributes to a reduction of the energy difference Δ E between the systems_STThereby improving reverse intersystem crossing capability.

As can be seen from Table 1, Δ E of all compounds_STAre all less than 0.3ev, and the small energy level difference between the singlet state and the triplet state is realized; meanwhile, the fluorescence lifetime of all compounds is in microsecond order, and the delayed fluorescence effect is obvious.

It is still another aspect of the present invention to provide an organic light emitting display device including an anode, a cathode, and at least one or more organic thin film layers (fig. 4) between the anode and the cathode, the organic thin film layers serving as a light emitting layer of the organic light emitting display device. The light-emitting material of the light-emitting layer includes one or more compounds among the compounds described in the present invention. As a special case, the light emitting material of the light emitting layer may be the compound itself according to the present invention.

Fig. 4 is a schematic structural view of an organic light emitting device according to an embodiment. The organic light emitting device includes a first electrode 1, a light emitting layer 2, and a second electrode 3, which are sequentially stacked. A substrate may additionally be provided under the first electrode 1 or above the second electrode 3. For use as a substrate, any substrate used in general organic light emitting devices may be used, and the substrate may be a glass substrate or a transparent plastic substrate each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.

The light emitting layer 2 is disposed on the first electrode 1, and the light emitting layer 2 may include a hole transport region, an emission layer, and an electron transport region. The hole transport region may be disposed between the first electrode 1 and the light emitting layer 2. The hole transport region may include at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or any combination thereof. The hole transport region may include only a hole injection layer or a hole transport layer. The hole transport region may include a buffer layer. The buffer layer may compensate an optical resonance distance according to a wavelength of light emitted from the light emitting layer 2, and may improve efficiency of the organic light emitting device.

The light emitting layer 2 may include a host and a dopant. The electron transport region may include at least one of a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof. For example, the electron transport region may have a hole blocking layer/electron transport layer/electron injection layer structure or an electron transport layer/electron injection layer structure, but the structure of the electron transport region is not limited thereto. The electron transport layer may have a single layer structure or a multi-layer structure including two or more different materials.

In the organic light emitting display device provided by the present invention, the anode material may be selected from metals such as copper, gold, silver, iron, chromium, nickel, manganese, palladium, platinum, etc., 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 also be selected from materials that facilitate hole injection in addition to the anode materials listed above, and combinations thereof, including known materials suitable for use as anodes.

In the organic light emitting display device provided by the present invention, the cathode material 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 substrate according to the present invention may be a rigid substrate (borosilicate glass, float soda lime glass, high refractive index glass, stainless steel, etc.) or a flexible substrate (e.g., a Polyimide (PI) plastic substrate, a polyethylene terephthalate (PET) plastic substrate, a polyethylene naphthalate (PEN) plastic substrate, a polyether sulfone resin substrate (PES), a polycarbonate plastic substrate (PC), an ultra-thin flexible glass substrate, a metal foil substrate, etc.).

The organic thin layer in the organic light emitting display device includes at least one emission layer (EML), and may further include at least one of other functional layers such as a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Electron Blocking Layer (EBL), a Hole Blocking Layer (HBL), an Electron Transport Layer (ETL), and an Electron Injection Layer (EIL).

The hole injection material, the hole transport material and the electron blocking material may be selected from N, N ' -diphenyl-N, N ' - (1-naphthyl) -1,1' -biphenyl-4, 4' -diamine (α -NPD), 4',4 ″ -tris (carbazol-9-yl) triphenylamine (TCTA), 1, 3-dicarbazole-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, N ' -diphenyl-N, N ' - (1-naphthyl) -1,1' -biphenyl-4, 4' -diamine (. alpha. -NPB), N ' -di (naphthalen-2-yl) -N, N ' -di (phenyl) biphenyl-4, 4' -diamine (NPB), poly (3, 4-ethylenedioxythiophene) -polystyrene sulfonic acid (PEDOT: PSS), Polyvinylcarbazole (PVK), 9-phenyl-3, 9-dicarbazole (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, TPBi, 2, 8-bis (diphenylphosphinoxy) dibenzofuran (PPF), bis (2-diphenylphosphino) diphenyl ether (DPEPO), lithium fluoride (LiF), 4, 6-bis (3, 5-bis (3-pyridinylphenyl) -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 (Cs2O3), bis (2-methyl-8-hydroxyquinoline-N1, O8) - (1,1' -biphenyl-4-hydroxy) aluminum (BALq), 8-hydroxyquinoline-lithium (Liq),Tris (8-hydroxyquinoline) aluminum (Alq)₃) And the like, but not limited to the above materials.

In the present invention, the organic light emitting display device may 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.

The aromatic compound of the present invention can be used as a dopant material, or a co-dopant material, or a host material in a light-emitting layer of an organic thin layer.

In the organic light emitting display device provided by the present invention, the light emitting layer of the organic light emitting display device includes one of a host material and a guest material, wherein the host material or the guest material may be one or more of the aromatic compounds per se described in the present invention.

In one embodiment of the organic light emitting display device, the light emitting layer includes a red light emitting material, and a singlet level of the red light emitting material is 1.61-1.99 eV.

In one embodiment of the organic light emitting display device, the light emitting layer includes a green light emitting material, and a singlet level of the green light emitting material is 2.15-2.52 eV.

In one embodiment of the organic light emitting display device, the light emitting layer includes a blue light emitting material, and a singlet level of the blue light emitting material is 2.52-2.73 eV.

In one embodiment of the organic light emitting display device 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 than one of the aromatic compounds; the difference between the HOMO of the host material and the HOMO of the guest material is less than 0.6eV, or the difference between the LUMO of the host material and the LUMO of the guest material is less than 0.6 eV.

In one embodiment of the organic light emitting display device provided by the present invention, the singlet energy level of the host material is higher than the singlet energy level of the guest material, and the difference between the singlet energy level of the host material and the singlet energy level of the guest material is less than 1.0 eV.

In one embodiment of the organic light-emitting display device 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 of the aromatic compounds described in the present invention, the guest material is selected from a fluorescent material, a thermally activated delayed fluorescent material, or a phosphorescent light-emitting material, a difference between a HOMO level of the host material and a HOMO level of the guest material is less than 0.6eV, or a difference between a LUMO level of the host material and a LUMO level of the guest material is less than 0.6 eV.

In one embodiment of the organic light-emitting display device 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 of the aromatic compounds described in the present invention, the guest material is selected from a fluorescent material or a thermally activated delayed fluorescent material, the singlet level of the guest material is smaller than the singlet level of the host material, and the difference between the singlet level of the host material and the singlet level of the guest material is smaller than 1.0 eV.

In one embodiment of the organic light-emitting display device 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 of the aromatic compounds described in the present invention, the guest material is selected from a phosphorescent material, a triplet energy level of the guest material is smaller than a triplet energy level of the host material, and a difference between the triplet energy level of the host material and the triplet energy level of the guest material is smaller than 1.0 eV.

In the present invention, the organic light emitting display device may be an OLED, which may be used in an organic light emitting display device, wherein the organic light emitting display device may be a display screen of a mobile phone, a computer, a liquid crystal television, a smart watch, a VR or AR helmet, a display screen of various smart devices, and the like. Fig. 5 is a schematic diagram of a display screen of a mobile phone, wherein 5 denotes the display screen.

The following examples 6 to 8 describe the preparation of organic light emitting devices and device properties.

Example 6

Vapor deposition preparation process of organic electroluminescent device

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^-6Under Pa, 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 (α -NPD) was evaporated, and then 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, a compound of the present invention was used as a dopant material for the light-emitting layer, and 3,3 '-bis (N-carbazolyl) -1,1' -biphenyl (mCBP) was used as a host material for the light-emitting layer, and the dopant material and the host material were simultaneously deposited 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 a thickness of 2.5nm and Al with a thickness of 100nm were sequentially evaporated on the electron transport layer as an Electron Injection Layer (EIL) and a cathode, thereby fabricating an organic light emitting display device.

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

The specific steps for preparing the undoped device comprise: the ITO glass is sequentially ultrasonically cleaned twice by acetone, alkaline cleaning solution, ultrapure water and isopropanol for 15 minutes each time, and then is treated for 15 minutes by an ozone cleaning machine. Spin-coating a 40nm thick PEDOT: PSS solution, dried in a vacuum oven at 120 ℃ for 45 minutes, dried in PEDOT: a TAPC layer and an mCP layer were prepared as a hole transport layer and an electron blocking layer, respectively, on PSS, and then a toluene solution (concentration of 12mg/mL) of the compound according to the present invention was coated as a light emitting layer with a thickness of 40 nm. And transferring the substrate into a vacuum chamber for thermal evaporation coating to prepare an electron transport layer (TmPyPb, 50nm), an electron injection layer (LiF, 0.5-1nm) and a cathode (Al, 100nm) so as to form a complete device.

The step of preparing the doped device further comprises: o-dichlorobenzene solutions (with the concentration of 12mg/mL) of the host luminescent material and the guest luminescent material are respectively prepared, 50uL (5%) of the guest material solution is added into the host material solution by a liquid-transferring gun, and the luminescent layer is coated after the mixture is uniformly stirred by magnetic force. The rest is the same as the specific steps for preparing the undoped device.

In this example, the solution processing method was an ink jet printing method.

The structure of the organic electroluminescent device according to the present invention is shown in fig. 4.

Example 7

Device prepared by vacuum evaporation method

Compounds P1-P10 are used as luminescent materials, non-doped devices N1-N10 are designed, and the structure is as follows:

ITO(100nm)/α-NPD(40nm)/TCTA(10nm)/P(40nm)/TmPyPb(50nm)/

LiF (0.5nm)/Al (100nm), the results are shown in Table 2.

TABLE 2 Performance results for undoped devices prepared by vacuum deposition (P1-P10 as emitters)

P1-P10 are used as fluorescent dopants, CBP is used as a main material, doped devices N11-N20 are designed, and the structure is as follows: ITO (100 nm)/alpha-NPD (40nm)/TCTA (10nm)/CBP P (40nm)/TmPyPb (50nm)/LiF (0.5nm)/Al (100 nm). In addition, as a comparison, BCzVBi is used as a fluorescent dopant, CBP is used as a host material, and a doped device C1 is designed, and has the structure:

ITO (100nm)/α -NPD (40nm)/TCTA (10nm)/CBP BCzVBi (40nm, 5%)/TmPyPb (50nm)/LiF (0.5nm)/Al (100nm) and the results are shown in Table 3.

TABLE 3 Performance results for doped devices prepared by vacuum deposition (P1-P10 as fluorescent dopants)

As can be seen from tables 2 and 3, the devices prepared by the undoped vacuum evaporation method using P1 to P10 as the light emitting material achieved a maximum external quantum efficiency of 12.5%. This shows that, thanks to the introduction of cycloalkyl, the interaction between D unit and a unit in the molecule is stronger, the molecular twisting strength is increased, a larger dihedral angle is formed, effective separation of HOMO orbital and LUMO is achieved, the exciton quenching problem caused by pi-pi stacking (pi-pi stacking) is weakened, meanwhile, the molecule maintains a certain molecular rigidity, and a higher photoluminescence quantum yield PLQY can be achieved, thereby obtaining more satisfactory device performance.

Furthermore, as can be seen from table 3, the EQE of the N9-N16 (doped) devices compared to the reference device C1 using the classical blue-emitting material BCzVBi as the fluorescent dopant_(max)The total area is obviously higher than that of a contrast device, the TADF characteristics of P1-P6, P21 and P30 are mainly benefited, and triplet excitons which are forbidden by the transition of traditional fluorescent molecules (such as BCzVBi) can be used for emitting light, so that the efficiency of the device is improved.

The doping device taking P1-P10 as the luminescent material of the doping body and mCBP as the main material obtains the maximum external quantum efficiency of 22.3 percent, and is further improved compared with a non-doping device, which shows that the pi-pi accumulation effect can be better avoided through doping, and the concentration quenching phenomenon is reduced.

A compound P2 is used as a host material, a fluorescent material or a phosphorescent material is used as a doping body, and doped devices N21-N22 are designed, and the structure is as follows: ITO (100 nm)/alpha-NPD (40nm)/TCTA (10nm)/P2 dopant (fluorescent material or phosphorescent material) (40nm)/TmPyPb (50nm)/LiF (0.5nm)/Al (100 nm). The fluorescent material is selected from rubrene, and the phosphorescent material is selected from Ir (ppy)3, and the results are shown in Table 4.

TABLE 4 Performance results of doped devices prepared by vacuum deposition

As can be seen from table 4, the doping device using the compound P2 of the present invention as the host material and rubrene and ir (ppy)3 as the dopant material respectively achieves the maximum external quantum efficiencies of 8.3% and 19.4%, which indicates that the compound of the present invention can be used as the host material of fluorescent material and phosphorescent material.

Example 8

Device prepared by solution method

Meanwhile, a solution method is adopted to process and manufacture a corresponding doped device N23 and a corresponding undoped device N24, and the device structure is as follows:

the structure of the doped device is as follows:

ITO(100nm)/PEDOT:PSS(40nm)/PVK:P3(40nm)/TmPyPb(50nm)/LiF(0.5nm)/Al(100nm)。

the doping device takes a classical polymer material PVK as a main material.

The non-doped device has the structure as follows:

ITO(100nm)/PEDOT:PSS(40nm)/P3(40nm)/TmPyPb(50nm)/LiF(0.5nm)/Al(100nm)。

the data relating to the above devices are shown in table 5.

Table 5 device performance results from solution process

As can be seen from table 5, the solution method for preparing the undoped and doped devices using the compound of the present invention as the light emitting material achieved the maximum external quantum efficiencies of 9.7% and 15.8%, respectively.

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. An aromatic compound selected from compounds of any one of the following structural formulae:

2. an organic light emitting display device comprising an anode, a cathode, 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 of the aromatic compounds according to claim 1.

3. The organic light-emitting display device according to claim 2, wherein the light-emitting material of the light-emitting layer is one or more of the aromatic compounds according to claim 1.

4. The organic light-emitting display device according to claim 2, wherein when the light-emitting material of the light-emitting layer is a red light-emitting material, a singlet level of the red light-emitting material is 1.61 to 1.99 eV;

when the luminescent material of the luminescent layer is a green luminescent material, the singlet state energy level of the green luminescent material is 2.15-2.52 eV;

when the luminescent material of the luminescent layer is a blue luminescent material, the singlet state energy level of the blue luminescent material is 2.52-2.73 eV.

5. The organic light-emitting display device according to claim 2, wherein the light-emitting layer comprises a host material and a guest material, wherein 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) diphenylether, 1, 3-bis [3, 5-bis (pyridin-3-yl) phenyl ] benzene, p-phenylene, 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, a guest material selected from one or more of the aromatic compounds of claim 1; the difference between the HOMO level of the host material and the HOMO level of the guest material is less than 0.6eV, or the difference between the LUMO level of the host material and the LUMO level of the guest material is less than 0.6 eV.

6. The organic light-emitting display device according to claim 5, wherein the singlet energy level of the host material is higher than the singlet energy level of the guest material, and a difference between the singlet energy level of the host material and the singlet energy level of the guest material is less than 1.0 eV.

7. The organic light-emitting display device according to claim 2, wherein the light-emitting material of the light-emitting layer comprises a host material selected from one or more of the aromatic compounds according to claim 1 and a guest material selected from a fluorescent material or a phosphorescent light-emitting material; the difference between the HOMO level of the host material and the HOMO level of the guest material is less than 0.6eV, or the difference between the LUMO level of the host material and the LUMO level of the guest material is less than 0.6 eV.

8. The organic light-emitting display device according to claim 5, wherein the light-emitting material of the light-emitting layer comprises a host material selected from one or more of the aromatic compounds according to claim 1 and a guest material selected from the fluorescent materials, wherein the singlet level of the guest material is smaller than that of the host material, and wherein the difference between the singlet level of the host material and the singlet level of the guest material is smaller than 1.0 eV.

9. The organic light-emitting display device according to claim 5, wherein the light-emitting material of the light-emitting layer comprises a host material selected from one or more of the aromatic compounds according to claim 1 and a guest material selected from a phosphorescent material, wherein the triplet energy level of the guest material is smaller than that of the host material, and wherein the difference between the triplet energy level of the host material and the triplet energy level of the guest material is smaller than 1.0 eV.