CN110835350A

CN110835350A - Organic electroluminescent material and organic electroluminescent device

Info

Publication number: CN110835350A
Application number: CN201810932293.5A
Authority: CN
Inventors: 邢其锋; 李之洋; 黄鑫鑫; 高月
Original assignee: Beijing Eternal Material Technology Co Ltd
Current assignee: Beijing Eternal Material Technology Co Ltd
Priority date: 2018-08-15
Filing date: 2018-08-15
Publication date: 2020-02-25

Abstract

The present invention provides a novel organic electroluminescent material and an organic electroluminescent device using the same. The organic electroluminescent material of the present invention is represented by the general formula (1) wherein Z, X¹～X²、Y¹～Y⁸、R¹～R³Ar, n, m and p have the meanings given in the description.

Description

Organic electroluminescent material and organic electroluminescent device

Technical Field

The invention relates to a novel compound, in particular to a compound for an organic electroluminescent device and application thereof in the organic electroluminescent device.

Background

The organic electroluminescent display (hereinafter referred to as OLED) has a series of advantages of self-luminescence, low-voltage direct current drive, full curing, wide viewing angle, light weight, simple composition and process and the like, and compared with the liquid crystal display, the organic electroluminescent display does not need a backlight source, has large viewing angle, low power, 1000 times of response speed of the liquid crystal display, and lower manufacturing cost than the liquid crystal display with the same resolution, so the organic electroluminescent device has wide application prospect.

With the continuous advance of the OLED technology in the two fields of illumination and display, people pay more attention to the research of efficient organic materials affecting the performance of OLED devices, and an organic electroluminescent device with good efficiency and long service life is generally the result of the optimized matching of the device structure and various organic materials. In the most common OLED device structures, the following classes of organic materials are typically included: hole injection materials, hole transport materials, electron transport materials, and light emitting materials (dyes or doped guest materials) and corresponding host materials of each color. The phosphorescent host materials used at present have single carrier transport capability, such as hole-based transport hosts and electron-based transport hosts. The single carrier transport ability causes mismatching of electrons and holes in the light emitting layer, resulting in severe roll-off of efficiency and shortened lifetime. At present, in the use process of a phosphorescent host, a bipolar material or a double-host material matching mode is adopted to solve the problem of unbalanced carriers of a single-host material. The bipolar material realizes the common transmission of electrons and holes in one compound, and the molecular structure is more complex; the double-main-body material is used for realizing the transmission and combination of electrons and holes in the luminous layer by matching two materials, wherein one material is used as an electron type material, the other material is used as a hole type material, the electrons and the holes are combined at an interface after being conducted by the two materials, the two materials have wider sources, and the better device performance can be realized by adopting a combination mode of different materials.

A compound that improves the luminous efficiency, stability and device lifetime of an organic electroluminescent device is disclosed in KR 20140136722A.

A class of compounds is disclosed in WO2016032150A for ensuring high luminous efficiency, low driving voltage and high device lifetime of organic electroluminescent devices.

However, there is still room for improvement in the luminescence property of the conventional organic electroluminescent materials, and development of new organic electroluminescent materials is in demand.

Documents of the prior art

Patent document

Patent document 1: KR20140136722A

Patent document 2: WO2016032150A

Disclosure of Invention

As described above, in order to obtain high light emission efficiency and improve device lifetime in an organic electroluminescent device, an organic electroluminescent material having more matched charge transport properties is required.

In view of the above, the main object of the present invention is to provide a compound having a large planar structure with multiple conjugated condensed rings; further, the organic electroluminescent material is applied to an organic electroluminescent device as a host material.

That is, the present inventors have found that a compound having a condensed heteroaromatic ring structure with polycyclic conjugated characteristics can achieve good luminous efficiency when incorporated as a material for a light-emitting layer in an organic electroluminescent device.

Specifically, as one aspect of the present invention, there is provided an organic electroluminescent material comprising a compound represented by the following general formula (1),

wherein the content of the first and second substances,

z is S or O;

X¹and X²One of them is a single bond and the other is selected from O, S, NR or CR^1’R^2’Wherein R is selected from substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀Heteroaryl radical, R^1’And R^2’Each independently selected from H, substituted or unsubstituted C₁～C₁₂Alkyl, substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀Heteroaryl radical, R^1’And R^2’Can be mutually connected to form a ring;

Y¹～Y⁸each independently selected from C, CH or N, wherein the case of C means with R¹Or R³The case of connection;

ar is selected from substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀A heteroaryl group;

R¹represents substituted or unsubstituted C₁～C₁₂Alkyl, substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀A heteroaryl group; when there are more than one R¹When a plurality of R¹May be the same or different from each other, and may be fused with an adjacent benzene ring or heterocyclic ring;

R²represents substituted or unsubstituted C₁～C₁₂Alkyl, substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀A heteroaryl group; when there are more than one R²When a plurality of R²May be the same or different from each other, and may be fused with an adjacent benzene ring;

R³represents substituted or unsubstituted C₁～C₁₂Alkyl, substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀A heteroaryl group; when there are more than one R³When a plurality of R³May be the same or different from each other, and may be fused with an adjacent benzene ring or heterocyclic ring;

m, n and p are independently selected from integers of 0-4;

substituted in "substituted or unsubstituted" by one or more substituents selected from C₁～C₁₂Alkyl of (C)₁～C₁₂Alkoxy group of (C)₆～C₁₈Aryl of (C)₃～C₁₂Substituted by a substituent in the heteroaryl, cyano or hydroxyl group.

As another aspect of the present invention, there is also provided a use of the organic electroluminescent material as described above in an organic electroluminescent device.

As still another aspect of the present invention, there is also provided an organic electroluminescent device comprising a first electrode, a second electrode, and an organic layer including at least a light-emitting layer interposed between the first electrode and the second electrode, characterized in that the organic layer contains therein an organic electroluminescent material as described above.

According to the invention, the compound with a large plane structure containing multiple conjugated condensed rings can improve the charge transmission efficiency and the luminous efficiency, and meanwhile, the structure can improve the thermodynamic stability of the material, is beneficial to solid-state accumulation among molecules and prolongs the service life of the material.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below.

In the present specification, unless otherwise indicated, the following terms have the following meanings:

in the present invention, the expression of Ca to Cb means that the group has carbon atoms a to b, and the carbon atoms do not include the carbon atoms of the substituents unless otherwise specified. In the present invention, the expression of chemical elements includes the concept of chemically identical isotopes, such as the expression of "hydrogen", and also includes the concept of chemically identical "deuterium" and "tritium". In the present invention, "D" may be used to represent "deuterium".

In the present specification, the substitution in "substituted or unsubstituted" means being substituted by one or more selected from C₁～C₁₂Alkyl of (C)₁～C₁₂Alkoxy group of (C)₆～C₁₂Aryl of (C)₃～C₁₂Heteroaryl, cyano, or a substituent of a hydroxyl groupMore specifically, the substituent may be substituted with a group selected from halogen, cyano, hydroxyl, alkoxy, alkyl, aryl, heteroaryl, preferably fluorine, cyano, methoxy, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, biphenyl, naphthyl, phenanthryl, fluorenyl, dibenzofuranyl, dibenzothienyl, pyridyl, quinolyl, phenylpyridinyl, pyridylphenyl and the like.

In the present specification, the alkyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 12. Specific examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, and the like.

In the present specification, the aryl group is not particularly limited, but preferably has 6 to 30 carbon atoms. Specific examples of aryl groups include phenyl, biphenyl, naphthyl, anthryl, phenanthryl, and the like.

In the present specification, the heteroaryl group is a heteroaryl group containing at least one of O, N, S, Si as a heteroatom, and the number of carbon atoms is preferably 3 to 30. Specific examples of heteroaryl groups include thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, and the like.

In the present specification, the expression of the "-" underlined loop structure means that the linking site is located at an arbitrary position on the loop structure where the linking site can be bonded.

Hereinafter, a material for an organic electroluminescent device according to an aspect of the present invention will be described.

The material for an organic electroluminescent device of the present invention comprises a compound represented by the following general formula (1).

In the above general formula (1), Z is S or O, preferably S, because when Z is an S atom, the electron donating ability of the heterocyclic ring including Z is stronger than that in the case where Z is an O atom, which is more favorable for charge transport and improves the light emitting efficiency.

In the above general formula (1), X¹And X²One of them is a single bond and the other is selected from O, S, NR or CR^1’R^2，Preferably X¹And X²One is a single bond and the other is NR.

And R is selected from substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀A heteroaryl group. Preferably, R is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl, fluorenyl, dibenzothienyl, dibenzofuranyl, triazinyl, quinazolinyl, pyrazinyl, pyrimidinyl.

And, R^1’And R^2’Each independently selected from H, substituted or unsubstituted C₁～C₁₂Alkyl, substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀Heteroaryl radical, R^1’And R^2’Can be connected with each other to form a ring.

As C₁～C₁₂Examples of alkyl groups include: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and the like, among which methyl, ethyl, n-propyl, isopropyl are preferred, and methyl is more preferred;

as C₁～C₁₂Alkoxy includes the above-mentioned C₁～C₁₂Examples of the alkyl group include groups bonded to-O-, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy and the like, among which methoxy, ethoxy, propoxy and more preferably methoxy;

as C₆～C₃₀Examples of aryl groups include: phenyl, biphenyl, terphenyl, naphthyl, anthryl, phenanthryl, fluorenyl, pyrenyl,

Fluoro, anthryl, benzo [ a ]]Anthracenyl, benzo [ c ]]PhenanthrylTriphenylene, benzo [ k ]]Fluoranthenyl, benzo [ g ]]

Radical, benzo [ b]Triphenylene, picene, perylene, etc., of which phenyl and naphthyl are preferred, and phenyl is more preferred;

as C₃～C₃₀The heteroaryl group may be a nitrogen-containing heteroaryl group, an oxygen-containing heteroaryl group, a sulfur-containing heteroaryl group, and the like, and specific examples thereof include: pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, quinolyl, isoquinolyl, naphthyridinyl, phthalazinyl, quinoxalinyl, quinazolinyl, phenanthridinyl, acridinyl, phenanthrolinyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, indolyl, benzimidazolyl, indazolyl, imidazopyridinyl, benzotriazolyl, carbazolyl, furyl, thienyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, thiadiazolyl, benzofuranyl, benzothienyl, benzoxazolyl, benzothiazolyl, benzisoxazolyl, benzisothiazolyl, benzoxadiazolyl, benzothiadiazolyl, dibenzofuranyl, dibenzothienyl, piperidyl, pyrrolidinyl, piperazinyl, morpholinyl, phenazinyl, phenothiazinyl, phenoxazinyl, and the like are preferred among them, pyridyl, quinolyl, pyrrolidinyl, piperazinyl, morpholinyl, phenazinyl, phenothiazinyl, and the like, Dibenzofuranyl and dibenzothienyl, and more preferably pyridyl.

In the above general formula (1), Y¹～Y⁸Each independently selected from C (in which case represents a carbon atom and R¹Or R³In the case of ligation), CH or N, preferably CH.

In the above general formula (1), Ar is selected from substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀A heteroaryl group. Preferably, Ar is selected from the group consisting of substituted or unsubstituted triazinyl, pyrimidinyl, quinazolinyl, quinoxalinyl, pyrazinyl, phenyl, naphthyl, biphenyl, fluorenyl, phenanthryl, anthracyl, pyrenyl, fluoranthenyl, benzanthryl, benzophenanthryl, benzofuranyl, benzothienyl, isobenzothienyl, pyridyl, quinolinyl, isoquinolinyl, acridinyl, phenanthridinyl, phenothiazinyl, phenazinylPyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthoimidazolyl, phenanthroimidazolyl, pyridoimidazolyl, pyrazinoimidazolyl, quinoxalinylamidazolyl, oxazolyl, benzoxazolyl, naphthooxazolyl, anthra oxazolyl, phenanthroizolyl, isoxazolyl, 1, 2-thiazolyl, 1, 3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyrazinyl, benzopyrimidinyl, quinoxalinyl, phenazinyl, naphthyridinyl, azacarbazolyl, benzocarbazinyl, phenanthrolinyl, 1, 2, 3-triazolyl, 1, 2, 4-triazolyl, benzotriazolyl, 1, 2, 3-oxadiazolyl, 1, 2, 4-oxadiazolyl, 1, 2, 5-oxadiazolyl, 1, 3, 4-oxadiazolyl, 1, 2, 3-thiadiazolyl, 1, 2, 4-thiadiazolyl, 1, 2, 5-thiadiazolyl, 1, 3, 4-thiadiazolyl, tetrazolyl, 1, 2, 4, 5-tetrazinyl, 1, 2, 3, 4-tetrazinyl, 1, 2, 3, 5-tetrazinyl, purinyl, pteridinyl, indolizinyl, or combinations thereof.

Preferably, X¹And X²One is a single bond and the other is NR; further preferred are groups in which one of R and Ar is an electron-withdrawing group and the other is an electron-donating group, such combinations of substituents being advantageous in increasing both electron and hole transport capability and achieving better device luminous efficiency, and further preferred examples of such combinations are those in which R is selected from substituted or unsubstituted, phenyl, naphthyl, biphenyl, fluorenyl, and Ar is selected from substituted or unsubstituted triazinyl, pyrimidinyl, quinazolinyl, quinoxalinyl, pyrazinyl, pyridoimidazolyl, pyrazinoimidazolyl, quinoxalimidazolyl, oxazolyl, benzoxazolyl, naphthooxazolyl, anthra oxazolyl, naphthooxazolyl, isooxazolyl, 1, 2-thiazolyl, 1, 3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyrazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalyl, pyrazinyl, phenazinyl, pyridazinyl, etc, Naphthyridinyl, azacarbazolyl, benzocarbazinyl or phenanthrolinyl.

R¹Represents substituted or unsubstituted C₁～C₁₂Alkyl, substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀A heteroaryl group; when in useIn the presence of a plurality of R¹When a plurality of R¹May be the same or different from each other, and may be fused with an adjacent benzene ring or heterocyclic ring.

R²Represents substituted or unsubstituted C₁～C₁₂Alkyl, substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀A heteroaryl group; when there are more than one R²When a plurality of R²May be the same or different from each other, and may be fused with an adjacent benzene ring.

R³Represents substituted or unsubstituted C₁～C₁₂Alkyl, substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀A heteroaryl group; when there are more than one R³When a plurality of R³May be the same or different from each other, and may be fused with an adjacent benzene ring or heterocyclic ring.

m, n and p are independently selected from 0 to 4, preferably 0 to 2.

The specific reason why the compound of the present invention has the above-mentioned mother nucleus of the polyconjugated condensed ring structure and the compound of the present invention has excellent performance as a material for a light-emitting layer is not clear, and the following reasons are presumed to be possible:

firstly, the fused heteroaromatic ring parent structure with the polycyclic conjugated characteristic has high bond energy among atoms and good thermal stability, is favorable for solid-state accumulation among molecules, and prolongs the service life of the material.

Secondly, the larger conjugated structure of the compound can effectively improve the migration rate of charges in molecules, improve the efficiency of materials and reduce voltage.

In addition, as described above, when X is present in the compound of the present invention¹And X²One of which is a single bond and the other is NR and one of R and Ar is an electron withdrawing group and the other is an electron donating group, and an electron withdrawing-donating structure exists in the molecule, and then the compound of the present invention has a very good balance of electron and hole migration in the molecule, and shows very high light-emitting efficiency in the device.

Further, preferable examples of the novel compounds of the general formula of the present invention include the following representative compounds a1 to a 79:

in addition, the invention also provides application of the compound containing the novel multi-conjugated fused ring structure in an organic electroluminescent device. Wherein the compound may be used as a host material of a light emitting layer.

Specifically, one embodiment of the present invention provides an organic electroluminescent device comprising a first electrode, a second electrode, and one or more organic layers interposed between the first electrode and the second electrode, wherein the organic layers comprise the above-described compound of a polyconjugated fused ring structure.

Further, the organic layer between the first electrode and the second electrode at least includes a light-emitting layer, and usually further includes an organic layer such as an electron injection layer, an electron transport layer, a hole injection layer, a hole blocking layer, and the like, and among them, the organic layer containing the compound of the present invention can be used as, but not limited to, a light-emitting layer.

The compound of the present invention can be applied to organic electronic devices, for example, organic electroluminescent devices, lighting devices, organic thin-film transistors, organic field-effect transistors, organic thin-film solar cells, large-area sensors such as information labels, electronic artificial skin sheets and sheet-type scanners, electronic paper, organic EL panels, and the like.

Next, the organic electroluminescent device will be explained in detail.

The organic electroluminescent device includes first and second electrodes on a substrate, and an organic layer between the electrodes, which may be a multi-layered structure. For example, the organic layer may include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer.

As the substrate, a substrate used for a general organic light emitting display, for example: glass, polymer materials, glass with TFT components, polymer materials, and the like.

The first electrode material may be Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), or tin dioxide (SnO)₂) Transparent conductive materials such as zinc oxide (ZnO), metal materials such as silver and its alloys, aluminum and its alloys, organic conductive materials such as PEDOT, and multilayer structures of these materials.

The second electrode material can be selected from, but not limited to, metals, metal mixtures, oxides, such as magnesium silver mixtures, LiF/Al, ITO, and the like.

The material of the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylenevinylene, polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly (3, 4-ethylenedioxythiophene)/poly (4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphorsulfonic acid (Pani/CSA), polyaniline/poly (4-styrenesulfonate) (Pani/PSS), aromatic amine derivatives such as compounds shown below in HT-1 to HT-34; or any combination thereof.

The hole injection layer is located between the anode and the hole transport layer. The hole injection layer may be a single compound material or a combination of a plurality of compounds. For example, the hole injection layer may employ one or more compounds of HT-1 to HT-34 described above, or one or more compounds of H11-HI3 described below; one or more of the compounds HT-1 to HT-34 may also be used to dope one or more of the compounds HI1-HI3 described below.

The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit different wavelength spectra, and may also include a Host material (Host). The light emitting layer may be a single color light emitting layer emitting a single color of red, green, blue, or the like. The single color light emitting layers of a plurality of different colors may be arranged in a planar manner in accordance with a pixel pattern, or may be stacked to form a color light emitting layer. When the light emitting layers of different colors are stacked together, they may be spaced apart from each other or may be connected to each other. The light-emitting layer may be a single color light-emitting layer capable of emitting red, green, blue, or the like at the same time.

According to different technologies, the luminescent layer material can be different materials such as fluorescent electroluminescent material, phosphorescent electroluminescent material, thermal activation delayed fluorescent luminescent material, and the like. In an OLED device, a single light emitting technology may be used, or a combination of a plurality of different light emitting technologies may be used. These technically classified different luminescent materials may emit light of the same color or of different colors.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light emitting layer thereof may be selected from, but not limited to, a combination of one or more of RPD-1 to RPD-28 listed below.

The OLED organic material layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may be an Electron Transport Layer (ETL) of a single-layer structure including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing a plurality of compounds. The electron transport region may also be a multilayer structure including at least one of an Electron Injection Layer (EIL), an Electron Transport Layer (ETL), and a Hole Blocking Layer (HBL).

The electron transport layer may be, but is not limited to, a combination of one or more of the compounds of ET1-ET57 listed below.

In one aspect of the invention, the electron transport layer material may be selected from, but is not limited to, the combination of one or more of ET-1 through ET-57 listed below.

An electron injection layer may also be included in the organic electroluminescent device between the electron transport layer and the second electrode, the electron injection layer material including, but not limited to, combinations of one or more of the following.

LiQ、LiF、NaCl、CsF、Li₂O、Cs₂CO₃、BaO、Na、Li、Ca。

Examples

The present invention will be described in further detail below with reference to specific embodiments in order to make the present invention better understood by those skilled in the art.

Synthetic examples

The specific production method of the above-mentioned novel compound of the present invention will be described in detail below by taking a plurality of synthesis examples as examples, but the production method of the present invention is not limited to these synthesis examples.

Compounds not mentioned in the synthesis process of the present invention are all starting products obtained commercially. The various chemicals used in the examples were purchased from commercially available chemical suppliers, including, but not limited to, Shang Tata Technique, Inc. and Xilonga chemical, Inc.

Analytical testing of intermediates and compounds in the present invention used an ABCIEX mass spectrometer (4000QTRAP) and Brookfield nuclear magnetic resonance spectrometer (400M Hz).

The synthesis of the compounds of the present invention is briefly described below.

Representative synthetic route 1:

the above synthesis method uses C-C coupling and C-N coupling, but is not limited to this coupling method, and those skilled in the art can select other methods without being limited to these methods.

More specifically, the following gives synthetic methods of representative compounds of the present invention.

Synthesis example 1: synthesis of Compound A1

To a reaction flask, M36 g (100mmol), 2-bromonitrobenzene 15.5g (110mmol), tetrakis (triphenylphosphine palladium) 0.9g (0.785mmol, 0.5%), toluene 1500ml, ethanol 1000ml, potassium carbonate 43.3g (314 mmol)/water 1000ml were added, and reaction was carried out at 80 ℃ for 3.5 hours. And stopping the reaction after the reaction is finished. After cooling to room temperature, the reaction mixture was separated, the organic phase was concentrated, and the resulting solid was filtered to give M1 as a yellow powder.

In N₂Under protection, 35g (100mmol) of M1 is added, 17.7g of triphenylphosphine (100mmol) and 1000ml of o-dichlorobenzene are added, heating reflux is carried out, reaction is carried out for 12h, after the reaction is finished, the solvent is removed by evaporation, and silica gel column chromatography is carried out, so as to obtain an M2 intermediate.

Into a reaction flask were charged M221.8g (100mmol), bromobenzene 16.5g (110mmol), Pd2(dba)₃0.9g (0.785mmol, 0.5%), toluene 1500ml, potassium carbonate 43.3g (314mmol), 100 deg.CThe reaction time is 3.5 h. And stopping the reaction after the reaction is finished. Cooled to room temperature, filtered and the resulting solid purified by recrystallization from toluene to give M3 as a yellow powder.

1000ml three-mouth bottle, stirring with magnetic force, N₂And (4) protecting. Sequentially adding the intermediate M320g and about 500ml of tetrahydrofuran, cooling to below-78 ℃ by liquid nitrogen, dropwise adding sec-butyl lithium, and controlling the temperature to be below-78 ℃. After the dropwise addition, controlling the temperature to be below-50 ℃, reacting for 2h, cooling to below-78 ℃, dropwise adding triisopropyl borate, controlling the temperature, naturally heating to room temperature after the dropwise addition, and reacting overnight. 500ml of water was added to the solution, diluted hydrochloric acid was added to adjust the pH to acidity, and extraction was performed with ethyl acetate, followed by liquid separation. Combining the organic phases, the organic phase is over anhydrous MgSO₄Drying, filtration through silica gel and spin-drying gave M4 as a yellow solid. Directly putting into the next reaction.

To a reaction flask, M436g (100mmol), 15.5g (110mmol) of 2-bromonitrobenzene, 0.9g (0.785mmol, 0.5%) of tetrakis (triphenylphosphine palladium), 1500ml of toluene, 1000ml of ethanol, 43.3g (314mmol) of potassium carbonate/1000 ml of water were added, and the reaction was carried out at 80 ℃ for 3.5 hours. And stopping the reaction after the reaction is finished. After cooling to room temperature, the reaction mixture was separated, the organic phase was concentrated, and the resulting solid was filtered to give M5 as a yellow powder.

N₂And (3) protecting, adding 35g (100mmol) of M5, adding 17.7g of triphenylphosphine (100mmol) and 1000ml of o-dichlorobenzene, heating and refluxing for 12 hours, reacting, evaporating to remove a solvent after the reaction is finished, and performing silica gel column chromatography to obtain an M6 intermediate.

In a 500ml single-necked bottle, N₂Under protection, sequentially adding M620g, NaH1g and DMF 200ml, stirring at normal temperature for 2h, adding 10g of 2-chloro-4, 6-diphenyl triazine, and reacting at normal temperature for 24 h. Stopping the reaction, adding water into the reaction solution to separate out yellow solid, filtering, leaching the filter cake with water and ethanol, and drying. Placing the solid in a single-mouth bottle, adding dimethylbenzene, and heating to reflux and boiling and washing twice. Filtering to obtain the final product A1.

¹H NMR(CDCl₃，400MHz)9.03(s，1H)，8.54(d，J＝8.0Hz，3H)，8.36(s，3H)，7.78(s，1H)，7.64-7.55(m，4H)，7.51(d，J＝8.0Hz，8H)，7.13(d，J＝10.0Hz，3H)。

Synthesis example 2: synthesis of Compound A9

N₂And (3) protecting, adding 35g (100mmol) of M1, adding 17.7g of triphenylphosphine (100mmol) and 1000ml of o-dichlorobenzene, heating and refluxing for 12 hours, reacting, evaporating to remove a solvent after the reaction is finished, and performing silica gel column chromatography to obtain an M2 intermediate.

Into a reaction flask, M221.8g (100mmol), 2-bromonaphthalene 16.5g (110mmol), Pd₂(dba)₃0.9g (0.785mmol, 0.5%), toluene 1500ml, potassium carbonate 43.3g (314mmol), reaction at 100 ℃ for 3.5 h. And stopping the reaction after the reaction is finished. Cooled to room temperature, filtered and the resulting solid purified by recrystallization from toluene to give M3 as a yellow powder.

1000ml three-mouth bottle, stirring with magnetic force, N₂And (4) protecting. Sequentially adding the intermediate M320g and about 500ml of tetrahydrofuran, cooling to below-78 ℃ by liquid nitrogen, dropwise adding sec-butyl lithium, and controlling the temperature to be below-78 ℃. After the dropwise addition, controlling the temperature to be below-50 ℃, reacting for 2h, cooling to below-78 ℃, dropwise adding triisopropyl borate, controlling the temperature, naturally heating to room temperature after the dropwise addition, and reacting overnight. 500ml of water was added to the solution, diluted hydrochloric acid was added to adjust the pH to acidity, and extraction was performed with ethyl acetate, followed by liquid separation. Combining the organic phases, the organic phase is over anhydrous MgSO₄Drying, filtering through silica gel, and spin-drying to obtain yellow solid M4. Directly putting into the next reaction.

In a 500ml single-necked bottle, N₂Under protection, sequentially adding M620g, NaH1g and DMF 200ml, stirring at normal temperature for 2h, adding 10g of 2-chloro-4-phenylquinazoline, and reacting at normal temperature for 24 h. Stopping the reaction, adding water into the reaction solution to separate out yellow solid, filtering, leaching the filter cake with water and ethanol, and drying. Placing the solid in a single-mouth bottle, adding dimethylbenzene, and heating to reflux and boiling and washing twice. Filtering to obtain the final product A9.

¹H NMR(CDCl₃，400MHz)8.58-8.33(m，10H)，8.19(s，3H)，8.13(s，2H)，8.03(s，5H)，7.85-7.57(m，11H)，7.57-7.40(m，11H)，7.36(s，2H)，7.13(d，J＝10.0Hz，6H)。

Synthetic example 3: synthesis of Compound A31

In a reaction flask, M36 g (100mmol), 2-chloroaniline 15.5g (110mmol), Pd were added₂(dba)₃0.9g (0.785mmol, 0.5%), toluene 1500ml, potassium carbonate 43.3g (314mmol), reaction at 100 ℃ for 3.5 h. And stopping the reaction after the reaction is finished. Cooled to room temperature, filtered and the resulting solid purified by recrystallization from toluene to give M1 as a yellow powder.

Into a reaction flask were charged M221.8g (100mmol), bromobenzene 16.5g (110mmol), Pd2(dba)₃0.9g (0.785mmol, 0.5%), toluene 1500ml, potassium carbonate 43.3g (314mmol), reaction at 100 ℃ for 3.5 h. After the reaction is finished, the reaction kettle is used for reaction,the reaction was stopped. Cooled to room temperature, filtered and the resulting solid purified by recrystallization from toluene to give M3 as a yellow powder.

In a 500ml single-necked bottle, N₂Under protection, sequentially adding M620g, NaH1g and DMF 200ml, stirring at normal temperature for 2h, adding 2-chloro-4-phenylquinazoline 10g, and reacting at normal temperature for 24 h. Stopping the reaction, adding water into the reaction solution to separate out yellow solid, filtering, leaching the filter cake with water and ethanol, and drying. Placing the solid in a single-mouth bottle, adding dimethylbenzene, and heating to reflux and boiling and washing twice. Filtering to obtain the final product A31.

¹H NMR(CDCl₃，400MHz)8.70(s，1H)，8.64-8.38(m，3H)，8.19(s，1H)，8.13(s，1H)，8.01(s，1H)，7.84-7.75(m，4H)，7.72(s，1H)，7.56(d，J＝12.0Hz，10H)，7.40(s，1H)，7.16(dd，J＝12.0，8.0Hz，4H)。

Application examples

The technical effects and advantages of the present invention are demonstrated and verified by testing practical use performance by specifically applying the compound of the present invention to an organic electroluminescent device.

(A) Preparation of organic electroluminescent device

The preparation process of the organic electroluminescent device is as follows:

the glass plate coated with the ITO transparent conductive layer was sonicated in a commercial detergent, rinsed in deionized water, washed in acetone: ultrasonically removing oil in an ethanol mixed solvent, baking in a clean environment until the water is completely removed, cleaning by using ultraviolet light and ozone, and bombarding the surface by using low-energy cationic beams;

placing the glass substrate with the first electrode in a vacuum chamber, and vacuumizing to 1 × 10^-5～9×10^-3Pa, performing vacuum evaporation on the first electrode layer film to form HI-3 serving as a hole injection layer, wherein the evaporation rate is 0.1nm/s, and the evaporation film thickness is 10 nm;

evaporating HT-5 on the hole injection layer in vacuum to serve as a hole transport layer of the device, wherein the evaporation rate is 0.1nm/s, and the total film thickness of the evaporation is 80 nm;

the light-emitting layer of the device is vacuum evaporated on the hole transport layer, the light-emitting layer comprises a main material and a dye material, the evaporation rate of the main material in each of the examples and the comparative examples is adjusted to be 0.1nm/s, the evaporation rate of the dye RPD-1 is set in a proportion of 3%, and the total evaporation film thickness is 30nm by using a multi-source co-evaporation method;

vacuum evaporating an electron transport layer material ET42 of the device on the light-emitting layer, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 30 nm;

LiF with the thickness of 0.5nm is vacuum-evaporated on the Electron Transport Layer (ETL) to be used as an electron injection layer, and an Al layer with the thickness of 150nm is used as a second electrode of the device.

(B) Method for testing organic electroluminescent device

Example 1E to E.C.were measured at the same brightness using a model PR 750 type photoradiometer model ST-86LA from Photoresearch corporation (photoelectric Instrument factory, university of Beijing) and a Keithley4200 test system7, and the organic electroluminescent devices prepared in comparative examples 1 and 2, driving voltage, current efficiency, and lifetime of the devices. Specifically, the voltage was raised at a rate of 0.1V per second, and it was determined that the luminance of the organic electroluminescent device reached 5000cd/m²The current density is measured at the same time as the driving voltage; the ratio of the luminance to the current density is the current efficiency. The life test of LT95 is as follows: using a luminance meter at 5000cd/m²The luminance drop of the organic electroluminescent device was measured to be 4750cd/m by maintaining a constant current at luminance²Time in hours.

Example 1

The following devices were prepared according to the above-described method using the compound a1 of the present invention as a host material in the light-emitting layer, and device performance tests were carried out according to the above-described organic electroluminescent device test method.

Example 2

The following devices were prepared according to the above-described method using the compound a9 of the present invention as a host material in the light-emitting layer, and device performance tests were carried out according to the above-described organic electroluminescent device test method.

Example 3

The following devices were prepared according to the above-described method using the compound a12 of the present invention as a host material in the light-emitting layer, and device performance tests were carried out according to the above-described organic electroluminescent device test method.

Example 4

The following devices were prepared according to the above-described method using the compound a31 of the present invention as a host material in the light-emitting layer, and device performance tests were carried out according to the above-described organic electroluminescent device test method.

Example 5

The following devices were prepared according to the above-described method using the compound a32 of the present invention as a host material in the light-emitting layer, and device performance tests were carried out according to the above-described organic electroluminescent device test method.

Example 6

The following devices were prepared according to the above-described method using the compound a42 of the present invention as a host material in the light-emitting layer, and device performance tests were carried out according to the above-described organic electroluminescent device test method.

Example 7

The following devices were prepared according to the above-described method using the compound a56 of the present invention as a host material in the light-emitting layer, and device performance tests were carried out according to the above-described organic electroluminescent device test method.

Example 8

The following devices were prepared according to the above-described method using the compound a71 of the present invention as a host material in the light-emitting layer, and device performance tests were carried out according to the above-described organic electroluminescent device test method.

Example 9

The following devices were prepared according to the above-described method using the compound a76 of the present invention as a host material in the light-emitting layer, and device performance tests were carried out according to the above-described organic electroluminescent device test method.

Comparative example 1

The dye material selected for the organic electroluminescent device in comparative example 1 was R-1,

the following devices were prepared in the manner described above using the compound R-1 as a host material in the light-emitting layer, and device performance tests were conducted in the manner described above for the organic electroluminescent device.

Comparative example 2

The dye material selected for the organic electroluminescent device in comparative example 2 was R-2,

the following devices were prepared in the manner described above using the compound R-2 as a host material in the light-emitting layer, and device performance tests were conducted in the manner described above for the organic electroluminescent device.

The organic electroluminescent device properties are given in the following table:

in examples 1 to 9, the compound of the present invention was used as a host material of an OLED light-emitting layer, and in comparative examples 1 and 2, a compound having a structure different from that of the polyconjugated fused ring mother nucleus of the present invention was used as a host material of an OLED light-emitting layer, and it was found that when organic electroluminescence properties of the compounds are compared: the devices of examples 1-9 achieved lower drive voltages, higher current efficiencies, and higher device lifetimes; this shows that the material based on the specific polyconjugated condensed ring mother nucleus of the invention has obvious advantages when being used as a main body for preparing an organic electroluminescent device.

Meanwhile, in example 8, when the compound a71 of the present invention is used as a host material of an OLED light-emitting layer, compared with other examples, the performance obtained by a71 is inferior; this shows that when the organic electroluminescent material of the present invention is used as a host material, the case where Z in the general formula (1) is an S atom has advantages of more significantly reducing the driving voltage and improving the luminous efficiency.

In addition, as can be seen from the data of the above examples, the organic electroluminescence performance of example 7 using the compound a56 of the present invention as a host material of the light emitting layer of the OLED is poor because: as mentioned above, X in the compound of the general formula (1) of the present invention¹And X²When one of the substituents is a single bond and the other is NR, and one of R and Ar is an electron-withdrawing group and the other is an electron-donating group, the combination of the substituents is beneficial to simultaneously improving the transmission capability of electrons and holes and realizing better luminous efficiency of the device.

The results show that the novel organic material is used for the organic electroluminescent device, can effectively reduce the take-off and landing voltage, improve the current efficiency and prolong the service life of the device, and is a main material with good performance.

Although the invention has been described in connection with the embodiments, the invention is not limited to the embodiments described above, and it should be understood that various modifications and improvements can be made by those skilled in the art within the spirit of the invention, and the scope of the invention is outlined by the appended claims.

Claims

1. An organic electroluminescent material comprising a compound represented by the general formula (1),

wherein the content of the first and second substances,

z is S or O;

Y¹～Y⁸each independently selected from C, CH or N;

R²represents substituted or unsubstituted C₁～C₁₂Alkyl, substituted or unsubstituted C₆～C₃₀Aryl or substituted or unsubstituted C₃～C₃₀Heteroaromatic compoundsA group; when there are more than one R²When a plurality of R²May be the same or different from each other, and may be fused with an adjacent benzene ring;

m, n and p are independently selected from integers of 0-4;

2. The organic electroluminescent material according to claim 1, wherein Z is S.

3. The organic electroluminescent material according to claim 1, wherein X is¹And X²One is a single bond and the other is NR.

4. The organic electroluminescent material as claimed in claim 3, wherein R is a group selected from a substituted or unsubstituted phenyl group, naphthyl group, fluorenyl group or biphenyl group, and Ar is a group selected from a substituted or unsubstituted triazinyl group, pyrimidinyl group, quinazolinyl group, quinoxalinyl group, pyrazinyl group, pyridoimidazolyl group, pyrazinoimidazolyl group, quinoxaloimidazolyl group, oxazolyl group, benzoxazolyl group, naphthooxazolyl group, anthra oxazolyl group, phenanthroizolyl group, isoxazolyl group, 1, 2-thiazolyl group, 1, 3-thiazolyl group, benzothiazolyl group, pyridazinyl group, benzopyrazinyl group, pyrimidinyl group, benzopyrimidinyl group, quinoxalinyl group, pyrazinyl group, phenazinyl group, naphthyridinyl group, azacarbazolyl group, benzocarbazinyl group or phenanthrolinyl group.

5. The organic electroluminescent material according to claim 1, wherein the compound is a compound having a structure selected from the group consisting of structures represented by a1 to a 79:

6. use of the organic electroluminescent material according to any one of claims 1 to 5 in an organic electroluminescent device.

7. Use according to claim 6, wherein the organic electroluminescent material is used as host material for the light-emitting layer.

8. An organic electroluminescent device comprising a first electrode, a second electrode and an organic layer comprising at least a light-emitting layer interposed between the first electrode and the second electrode, characterized in that the organic layer contains the organic electroluminescent material according to any one of claims 1 to 5.

9. The organic electroluminescent device according to claim 8, wherein the organic layer containing the organic electroluminescent material is a light-emitting layer.