CN110698485A

CN110698485A - Compound and application thereof

Info

Publication number: CN110698485A
Application number: CN201911149003.0A
Authority: CN
Inventors: 刘叔尧; 孙恩涛; 方仁杰
Original assignee: Beijing Eternal Material Technology Co Ltd
Current assignee: Beijing Eternal Material Technology Co Ltd
Priority date: 2019-11-21
Filing date: 2019-11-21
Publication date: 2020-01-17

Abstract

The invention relates to a compound and application thereof, wherein the compound has a structure shown in a formula I, a mother nucleus is formed by azabenzoindolizine, and the structure of the compound has good electron deficiency property, so that the compound is favorable for electron injection, and simultaneously has a relatively larger planar structure, so that the electron mobility is improved, and the electron mobility of the whole newly-constructed molecule is favorably improved. The structural characteristics of the two aspects can make the molecule show good electron injection and migration performance. Therefore, when the compound is used as an electron transport layer material in an organic electroluminescent device, the electron injection and migration efficiency in the device can be effectively improved, so that the excellent effects of high luminous efficiency and low starting voltage of the device are ensured.

Description

Compound and application thereof

Technical Field

The invention relates to the technical field of organic electroluminescence, in particular to a compound and application thereof.

Background

Organic Light Emission Diodes (OLED) devices are a kind of devices with sandwich-like structure, which includes positive and negative electrode films and Organic functional material layers sandwiched between the electrode films. And applying voltage to the electrodes of the OLED device, injecting positive charges from the positive electrode and injecting negative charges from the negative electrode, and transferring the positive charges and the negative charges in the organic layer under the action of an electric field to meet for composite luminescence. Because the OLED device has the advantages of high brightness, fast response, wide viewing angle, simple process, flexibility and the like, the OLED device is concerned in the field of novel display technology and novel illumination technology. At present, the technology is widely applied to display panels of products such as novel lighting lamps, smart phones and tablet computers, and further expands the application field of large-size display products such as televisions, and is a novel display technology with fast development and high technical requirements.

With the continuous advance of OLEDs in both lighting and display areas, much attention has been paid to the research on their core materials. This is because an efficient, long-lived OLED device is generally the result of an optimized configuration of the device structure and various organic materials, which provides great opportunities and challenges for chemists to design and develop functional materials with various structures. Common functionalized organic materials are: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, and light emitting host materials and light emitting objects (dyes), and the like.

In order to prepare an OLED light-emitting device with lower driving voltage, better light-emitting efficiency and longer service life, the performance of the OLED device is continuously improved, the structure and the manufacturing process of the OLED device need to be innovated, and photoelectric functional materials in the OLED device need to be continuously researched and innovated, so that functional materials with higher performance can be prepared. Based on this, the OLED material industry has been working on developing new organic electroluminescent materials to achieve low starting voltage, high luminous efficiency and better lifetime of the device.

In the current manufacturers of OLED screens, Liq (lithium octahydroxyquinoline) is widely used as a technical means for doping into an ET material layer, so as to achieve low voltage and high efficiency of devices, and have the effect of prolonging the service life of the devices. Liq mainly has the effect that a small amount of metal lithium can be reduced under the action of electrons injected from the cathode, so that the N-doping effect of the electron transport material is achieved, the injection effect of electrons is remarkably improved, and on the other hand, lithium ions can achieve the effect of improving the electron mobility of the ET material through the coordination effect of N atoms in the electron transport material, so that a device with the Liq doped with the ET has low working voltage and high luminous efficiency.

However, in order to further satisfy the increasing demand for the photoelectric properties of OLED devices and the demand for energy saving of mobile electronic devices, new and efficient OLED materials are continuously developed, wherein the development of new electron transport materials with high electron injection capability and high mobility is of great importance.

Disclosure of Invention

The invention aims to provide a compound which has good electron injection and migration performance, can improve the electron injection and migration efficiency of an organic electroluminescent device, and obtains excellent effects of high luminous efficiency and low starting voltage.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a compound, which has a structure shown in a formula I;

in the formula I, X is¹、X²And X³Each independently selected from CR₁、CR₂、CR₃Or N, and at least one is N;

the R is₁、R₂、R₃、R₄、R₅And R₆Each independently selected from hydrogen, halogen, cyano, substituted or unsubstituted C1-C12 (e.g. C2, C3, C4, C5, C6, C7, C8, C9, C10) chain alkyl, substituted or unsubstituted C3-C12 (e.g. C4, C5, C6, C7, C8, C9, C10, etc.) cycloalkyl, substituted or unsubstituted C6-C30 (e.g. C10, C12, C14, C16, C18, C20, C26, C28, etc.) aryl, substituted or unsubstitutedAny one of C3 to C60 (e.g., C4, C6, C8, C12, C15, C18, C20, C23, C25, C28, C30, C36, C40, C46, C48, C50, C54, C58, etc.);

in the formula I, m is an integer of 0-3, such as 1 or 2; when m is 2 or 3, R₆The same or different;

in the formula I, L is any one selected from a single bond, substituted or unsubstituted C6-C30 (such as C10, C12, C14, C16, C18, C20, C26, C28 and the like) arylene, substituted or unsubstituted C3-C30 (such as C4, C6, C8, C12, C15, C18, C20, C23, C25, C28 and the like) heteroarylene;

in formula I, Ar is selected from any one of C6-C60 (such as C8, C12, C15, C18, C20, C23, C25, C28, C30, C36, C40, C46, C48, C50, C54, C58 and the like) aryl substituted with an electron-withdrawing group, substituted or unsubstituted C3-C60 (such as C4, C6, C8, C12, C15, C18, C20, C23, C25, C28, C30, C36, C40, C46, C48, C50, C54, C58 and the like) heteroaryl, and Ar is an electron-withdrawing group;

when the above groups have substituents, the substituents are each independently selected from halogen, C1 to C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.) chain alkyl, C3 to C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C1 to C10 (e.g., C2, C3, C4, etc.) haloalkyl, C4 to C4 (e.g., C4, etc.) alkenyl, C4 to C4 (e.g., C4, etc.) C4, C4, etc. C4, C, C8, C12, C15, C18, C20, C23, C25, C28, C30, C36, C40, C46, C48, C50, C54, C58, etc.) monocyclic heteroaryl, C6 to C30 (e.g., C8, C12, C15, C18, C20, C23, C25, C28, etc.) fused ring heteroaryl, or a combination of at least two thereof. When a substituent exists in the "substituted or unsubstituted" group in the present invention, the substituent has the above selection range, and may be substituted with one group, or may be substituted with two or more groups, which is not described in detail below.

The parent nucleus of the compound of the formula I is formed by azabenzindolizine, and the N atom on the benzene ring is not in the ortho position with the N of the indolizine group, so that the weak electron donating property of the indolizine can be balanced. The structural characteristics of the two aspects can make the molecule show good electron injection and migration performance. Therefore, when the compound is used as an electron transport layer material in an organic electroluminescent device, the electron injection and migration efficiency in the device can be effectively improved, so that the excellent effects of high luminous efficiency and low starting voltage of the device are ensured.

The "electron-withdrawing group" in the present invention means a group in which the electron cloud density on the benzene ring is decreased after the group substitutes for hydrogen on the benzene ring, and usually such a group has a Hammett value of more than 0.6. The Hammett value is a representation of the charge affinity for a particular group and is a measure of the electron withdrawing group (positive Hammett value) or electron donating group (negative Hammett value). The Hammett equation is described In more detail In Thomash, Lowry and Kathelen Schueler Richardson, "mechanics and Theory In organic chemistry", New York,1987, page 143-151, which is incorporated herein by reference. Such groups may be listed but are not limited to: triazinyl, pyrimidinyl, benzopyrimidinyl, benzopyridyl, naphthyridinyl, phenanthridinyl, pyrazinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, pyridazinyl, and alkyl-or aryl-substituted ones of the foregoing.

Preferably, the compound has a structure represented by (2-1) to (2-6);

the R is₁、R₂、R₃、R₄、R₅、R₆M, L and Ar all have the same meaning as in formula I.

The structures shown in (2-1) to (2-6) are preferably selected, 2-3N atoms are totally arranged on a mother nucleus, the structures are not connected with N of the indolizine group at the ortho position, the weak electron supply performance of the indolizine can be balanced, and the increased 1-2 nitrogen atoms can enable the whole structure group to have stronger electron-withdrawing performance, so that the electron injection and migration capability of the material can be further improved, the light-emitting efficiency of the device is improved, and the driving voltage is reduced.

Preferably, the electron withdrawing group includes any one or a combination of at least two of nitro, arylamino, cyano, halogen, phosphorus oxy, carbonyl and acyl groups, preferably halogen and/or cyano. The aryl group of C6-C60 can be substituted with an electron-withdrawing group, or can be simultaneously substituted with two or more electron-withdrawing groups, and the two or more electron-withdrawing groups can be the same or different.

Preferably, the Ar is selected from any one of substituted or unsubstituted triazinyl, substituted or unsubstituted pyrimidyl, substituted or unsubstituted pyridyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted quinolyl, substituted or unsubstituted imidazolyl, C6-C20 aryl substituted with cyano, and C6-C20 aryl substituted with halogen.

Preferably, the L is selected from any one of a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted naphthyl group, and a substituted or unsubstituted anthracenyl group.

Preferably, said R is₁、R₂、R₃、R₄、R₅And R₆Each independently selected from any one of hydrogen, phenyl, biphenyl, naphthyl, cyano, halogen, pyridyl, C1-C4 chain alkyl and C3-C6 cycloalkyl.

Preferably, the compound has any one of the following structures A1 to a 108:

the second object of the present invention is to provide the use of the compound according to the first object for the application to electronic devices.

Preferably, the electronic device includes an organic electroluminescent device, an optical sensor, a solar cell, a lighting element, an organic thin film transistor, an organic field effect transistor, an organic thin film solar cell, an information label, an electronic artificial skin sheet, a sheet type scanner, or electronic paper, preferably an organic electroluminescent device.

Preferably, the compound of one of the objects is used as an electron transport layer material of the organic electroluminescent device.

The invention also provides an organic electroluminescent device which comprises a substrate, a first electrode, a second electrode and at least one organic layer positioned between the first electrode and the second electrode, wherein the organic layer contains at least one compound for one purpose.

Preferably, the organic layer comprises an electron transport layer containing at least one compound according to one of the objects.

Specifically, an organic electroluminescent device (OLED) includes first and second electrodes, and an organic material layer between the electrodes. The organic material may in turn be divided into a plurality of regions. For example, the organic material layer may include a hole transport region, a light emitting layer, and an electron transport region.

In particular embodiments, a substrate may be used below the first electrode or above the second electrode. The substrate is a glass or polymer material having excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a Thin Film Transistor (TFT) may be provided on a substrate for a display.

The first electrode may be formed by sputtering or depositing a material used as the first electrode on the substrate. When the first electrode is used as an anode, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), tin dioxide (SnO) may be used₂) And transparent conductive oxide materials such as zinc oxide (ZnO), and any combination thereof. When the first electrode is used as a cathode, a metal or an alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), or any combination thereof can be used.

The organic material layer may be formed on the electrode by vacuum thermal evaporation, spin coating, printing, or the like. The compound used as the organic material layer may be an organic small molecule, an organic large molecule, and a polymer, and a combination thereof.

The hole transport region is located between the anode and the light emitting layer. The hole transport region may be a Hole Transport Layer (HTL) of a single layer structure including a single layer containing only one compound and a single layer containing a plurality of compounds. The hole transport region may also be a multilayer structure including at least one of a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), and an Electron Blocking Layer (EBL).

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 HI-1 to HI-3 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 HI-1 to HI-3 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 a fluorescent electroluminescence technique. The luminescent layer fluorescent host material may be selected from, but is not limited to, the combination of one or more of BFH-1 through BFH-16 listed below.

In one aspect of the invention, the light-emitting layer employs a fluorescent electroluminescence technique. The luminescent layer fluorescent dopant may be selected from, but is not limited to, combinations of one or more of BFD-1 through BFD-12 listed below.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The host material of the light emitting layer is selected from, but not limited to, one or more of GPH-1 to GPH-80.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light emitting layer can be selected from, but is not limited to, one or more of GPD-1 to GPD-47 listed below.

Wherein D is deuterium.

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.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light-emitting layer can be selected from, but is not limited to, one or more of YPD-1 to YPD-11 listed below.

The organic OLED light-emitting device of the present invention includes an electron transport region between a light-emitting layer and a 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 include a multilayer structure of at least one of an Electron Injection Layer (EIL), an Electron Transport Layer (ETL), and a Hole Blocking Layer (HBL).

The electron transport region may also be formed by applying the organic electronic material of the present invention to a structure including at least one or more layers of an Electron Injection Layer (EIL), an Electron Transport Layer (ETL), and a Hole Blocking Layer (HBL), although the material of the electron transport region may also be combined with one or more of ET-1 to ET-57 listed below.

An electron injection layer may also be included in the device between the electron transport layer and the cathode, the electron injection layer material including, but not limited to, combinations of one or more of the following: LiQ, LiF, NaCl, CsF, Li₂O、Cs₂CO₃BaO, Na, Li or Ca.

Compared with the prior art, the invention has the following beneficial effects:

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

A representative synthetic route for the compounds of formula I of the present invention is as follows:

basic chemical materials such as ethanol, dioxane, toluene, Tetrahydrofuran (THF), 2-methyltetrahydrofuran, xylene, toluene, potassium acetate, potassium carbonate, tetratriphenylphosphine palladium, 2-dicyclohexylphosphine-2 ',4',6 '-triisopropylbiphenyl, 1' -bisdiphenylphosphinoferrocene palladium dichloride, 2-dicyclohexylphosphino-2 ',6' -dimethoxybiphenyl, tris (dibenzylideneacetone) dipalladium (0) and the like used in the present invention are purchased from Shanghai Tantake technology GmbH and Xilong chemical Co., some of the intermediates are purchased from pharmaceutical intermediates manufacturers.

The following halide intermediates were custom synthesized to the chemical manufacturer (synthesis according to the above procedure is also possible by those skilled in the art):

the mass spectrometer used for determining the following compounds was a ZAB-HS type mass spectrometer measurement (manufactured by Micromass, UK).

The following synthesis examples provide specific synthetic methods for compounds:

synthesis example 1:

synthesis of Compound A1

Preparation of Compound A1-1

A500 mL three-necked flask was charged with M1(28g, 100mmol), phenylboronic acid (14.64g, 120mmol), and potassium carbonate (41.4g, 300mmol) followed by 280mL of toluene40mL of ethanol and 40mmol of water. After nitrogen substitution was carried out three times, tetrakis (triphenylphosphine) palladium (Pd (PPh) was added₃)₄1.1g, 1mmol) and then heated to 110 c for 5h, TLC showed the reaction was complete. Toluene was concentrated, water was added and extraction was performed with DCM, and the organic phase was collected, concentrated and then stirred with silica gel to obtain compound A1-1(17.6g, yield 63%) by silica gel column chromatography.

Preparation of Compound A1

Compound A1-1(13.90g, 50mmol), potassium carbonate (20.7g, 150mmol) and 2- (4-boronic acid pinacol ester group) phenyl-4, 6-diphenyl-1, 3, 5-triazine (13.6g, 50mmol) were added to a flask containing dioxane, water (200mL:40mL), nitrogen was replaced with stirring at room temperature, and tris (dibenzylacetone) dipalladium (Pd) was added₂(dba)₃0.74g, 1.02mmol) and 2-dicyclohexylphosphine-2 ',6' -dimethoxybiphenyl (Sphos, 0.74g, 2.04 mmol). After the addition was complete, the reaction was refluxed with stirring under nitrogen for 8 hours and TLC showed completion. Cooled to room temperature and the precipitated white solid was filtered. The resulting solution was dissolved in 2L of toluene under reflux, subjected to column chromatography under reduced pressure and filtered, collected, concentrated and then recrystallized to obtain Compound A1(14.05g, yield 51%) as a white solid. Calculated molecular weight: 551.21, found C/Z: 551.2.

Synthesis example 2:

synthesis of Compound A3

Preparation of Compound A3-1

A500 mL three-necked flask was charged with M2(27.9g, 100mmol), pinacol diboron diboride (30.48g, 120mmol), and potassium acetate (29.4g, 300mmol) followed by 300mL dioxane. After nitrogen substitution was carried out three times, palladium acetate (Pd (OAc) was added₂0.22g, 1mmol) and Sphos (0.83g, 2mmol), followed by heating to 120 ℃ for 8h, TLC showed complete reaction. Dioxane was concentrated, water was added and extraction was performed with DCM, the organic phase was collected, after concentration, silica gel was added and the mixture was stirred, and compound a3-1 was obtained by silica gel column chromatography (29.6g, yield 80%).

Preparation of Compound A3

Compound A3-1(18.55g, 50mmol), potassium carbonate (20.7g, 150mmol) and 2- (3, 3-bromobiphenyl) -4, 6-diphenyl-1, 3, 5-triazine (23.15g, 50mmol) were added to a flask containing toluene, ethanol, water (200mL:40mL:40mL), nitrogen was replaced at room temperature with stirring, and Pd (PPh) was added₃)₄(1.1g, 1 mmol). After the addition was complete, the reaction was refluxed with stirring under nitrogen for 4 hours and TLC showed completion. Cooled to room temperature and the precipitated white solid was filtered. The resulting solution was dissolved in 3L of toluene under reflux, subjected to column chromatography under reduced pressure and filtered, collected, concentrated and recrystallized to obtain Compound A3(23.55g, yield 75%) as a white solid. Calculated molecular weight: 628.24, found C/Z: 628.2.

Synthesis example 3:

synthesis of Compound A10

Compound M3(9.09g, 30mmol), potassium carbonate (12.42g, 90mmol) and 2- (4-boronic acid pinacol ester group) phenyl-4, 6-bis (2-pyridyl) -pyridine (13.05g, 30mmol) were added to a flask containing tetrahydrofuran: water (200mL:40mL), nitrogen gas was replaced at room temperature with stirring, and Pd (PPh)₃)₄(1.1g, 1 mmol). After the addition was complete, the reaction was refluxed with stirring under nitrogen for 6 hours and TLC showed completion. Cooled to room temperature and the precipitated white solid was filtered. The resulting solution was dissolved in 2L of toluene under reflux, subjected to column chromatography under reduced pressure and filtered, collected, concentrated and then recrystallized to obtain Compound A10(11.75g, yield 68%) as a white solid. Calculated molecular weight: 576.21, found C/Z: 576.2.

Synthesis example 4:

synthesis of Compound A18

Preparation of Compound A18-1

A500 mL three-necked flask was charged with M4(17.84g, 50mmol), 2-pyridineboronic acid (7.38g, 60mmol), and potassium carbonate (20.7g, 150mmol), followed by 200mL tetrahydrofuran and 40mL water. After three nitrogen replacements, tetrakistriphenylphosphine palladium (0.55g, 0.5mmol) was added and then heated to reflux for 5h, and TLC showed completion. Tetrahydrofuran was concentrated, water was added and extraction was performed with DCM, and the organic phase was collected, concentrated and stirred with silica gel to obtain compound A18-1(14.77g, yield 83%) by silica gel column chromatography.

Preparation of Compound A18

Compound A18-1(10.68g, 30mmol), potassium carbonate (12.42g, 90mmol) and 3-fluoro 5- (1-naphthalene) -p-phenylboronic acid (10.26g, 30mmol) were charged into a flask containing 150mL dioxane and 20mL water, and after nitrogen exchange at room temperature with stirring, tris (dibenzylideneacetone) dipalladium (0) (0.37g, 0.05mmol) and 2-dicyclohexylphosphino-2 ',6' -dimethoxybiphenyl (0.37g, 1.02mmol) were added. After the addition, the mixture was stirred under nitrogen atmosphere and heated under reflux to complete the reaction of A18-1, and the heating was stopped. Naturally cooling to room temperature, and filtering precipitated white solid. The resulting solution was dissolved in 1.5L of xylene under heating and refluxing, subjected to column chromatography under reduced pressure and filtered, collected, concentrated and then recrystallized to obtain Compound A18(9.82g, yield 55%) as a white solid. Calculated molecular weight: 618.22, found C/Z: 618.2.

Synthesis example 5:

synthesis of Compound A33

Preparation of Compound A33-1

A500 mL three-necked flask was charged with M5(17.79g, 50mmol), 2-pyridineboronic acid (7.38g, 60mmol), and potassium carbonate (20.7g, 150mmol), followed by 200mL of 2-methyltetrahydrofuran and 40mL of water. After three nitrogen replacements, tetrakistriphenylphosphine palladium (0.55g, 0.5mmol) was added and then heated to 80 ℃ for 7h, TLC showed complete reaction. 2-methyltetrahydrofuran was concentrated, water was added and extraction was performed with DCM, and the organic phase was collected, concentrated, and then added with silica gel to mix it with a sample, followed by silica gel column chromatography to obtain Compound A33-1(14.38g, yield 81%).

Preparation of Compound A33

Compound A33-1(10.65g, 30mmol) and A33-2(14.4g, 30mmol) were put in a flask containing dioxane and water (150mL:20mL), potassium carbonate (12.42g, 90mmol) was added, after completion of addition, nitrogen gas was replaced with stirring at room temperature, and Pd was added₂(dba)₃(0.37g, 0.05mmol) and 2-dicyclohexylphosphonium-2 ',4',6' -triisopropylbiphenyl (0.41g, 1.02 mmol). After the addition was complete, the reaction was refluxed with stirring under nitrogen for 8 hours and TLC showed completion. Cooled to room temperature and the precipitated white solid was filtered. The resulting solution was dissolved in 4L of toluene under reflux, subjected to column chromatography under reduced pressure and filtered, collected, concentrated and then recrystallized to obtain Compound A33(11.91g, yield 59%) as a white solid. Calculated molecular weight: 673.23, found C/Z: 673.2.

Synthesis example 6:

synthesis of Compound A42

Preparation of Compound A42-1

A500 mL three-necked flask was charged with M6(28g, 100mmol), phenylboronic acid (14.64g, 120mmol), 280mL of toluene, 40mL of ethanol, and potassium carbonate (41.4g, 300mmol) was then weighed out and dissolved in 40mL of water. After three nitrogen replacements, Pd (PPh) was added₃)₄(1.1g, 1mmol) and then heated to 110 ℃ for 7h, TLC showed completion of the reaction. Toluene was concentrated, water was added and extraction was performed with DCM, and the organic phase was collected, concentrated and then stirred with silica gel to obtain compound A42-1(19.46g, yield 70%) by silica gel column chromatography.

Preparation of Compound A42

Compound A42-1(8.34g, 30mmol) and A42-2(14.4g, 30mmol) were added to a flask containing dioxane: water (150mL:20mL), potassium carbonate (12.42g, 90mmol) was added thereto, and after replacement of nitrogen gas at room temperature with stirring, tris (dibenzylideneacetone) dipalladium (0) (0.37g, 0.05mmol) and Sphos (0.37g, 1.02mmol) were weighed. After the addition was complete, the reaction was refluxed with stirring under nitrogen for 6 hours and TLC showed completion. Cooled to room temperature and the precipitated white solid was filtered. The resulting solution was dissolved in 3L of toluene under reflux, subjected to column chromatography under reduced pressure and filtered, collected, concentrated and then recrystallized to obtain Compound A42(11.96g, yield 62%) as a white solid. Calculated molecular weight: 623.24, found C/Z: 623.2.

Synthesis example 7

Synthesis of Compound A57

Preparation of Compound A57-1

A500 mL single-neck flask was charged with M7(28g, 100mmol), phenylboronic acid (14.64g, 120mmol), and potassium carbonate (41.4g, 300mmol), followed by 280mL of toluene, 40mL of ethanol, and 40mL of water. After three nitrogen replacements, tetrakistriphenylphosphine palladium (1.1g, 1mmol) was added, followed by heating to 105 ℃ for reaction, and M7 was checked by TLC for completion. The reaction was stopped and toluene was concentrated, water was added and extraction was performed with DCM, the organic phase was collected, after concentration, silica gel was added and the sample was stirred, and compound A57-1 was obtained by silica gel column chromatography (20.29g, yield 73%).

Preparation of Compound A57

Compound a57-1(8.34g, 30mmol), potassium carbonate (12.42g, 90mmol) and a57-2(15.0g, 30mmol) were added to a solution containing dioxane: in a flask with water (150mL:20mL), nitrogen was purged with stirring at room temperature, and tris (dibenzylideneacetone) dipalladium (0) (0.37g, 0.05mmol) and 2-dicyclohexylphosphorus-2 ',4',6' -triisopropylbiphenyl (0.37g, 1.02mmol) were added. After the addition was complete, the reaction was refluxed with stirring under nitrogen for 7 hours and TLC showed completion. Cooled to room temperature and the precipitated white solid was filtered. The resulting solution was dissolved in 4L of toluene under reflux, subjected to column chromatography under reduced pressure and filtered, collected, concentrated and then recrystallized to obtain Compound A57(11.52g, yield 64%) as a white solid. Calculated molecular weight: 600.23, found C/Z: 600.2.

Synthesis example 8

Synthesis of Compound A76

Adding M8(9.57g, 30mmol), potassium carbonate (12.42g, 90mmol) and A76-1(12.24g, 30mmol)Putting into a flask, measuring 150mL of dioxane and 25mL of water, adding into the system, stirring at room temperature, replacing nitrogen, and adding Pd₂(dba)₃(0.37g, 0.05mmol) and Sphos (0.37g, 1.02 mmol). After the addition, the mixture is stirred and heated under the protection of nitrogen for reflux reaction, and TLC detection is carried out every 2 hours until M8 is completely reacted, and then the reaction is stopped. Cooled to room temperature and the precipitated white solid was filtered. The resulting solution was dissolved in 3L of toluene under reflux, subjected to column chromatography under reduced pressure and filtered, collected, concentrated and then recrystallized to obtain Compound A76(8.30g, yield 49%) as a white solid. Calculated molecular weight: 565.23, found C/Z: 565.2.

Synthesis example 9

Synthesis of Compound A88

Preparation of Compound A88-1

A500 mL three-necked flask was charged with M9(34g, 100mmol), o-chlorobenzoic acid (15.6g, 120mmol), and potassium carbonate (41.4g, 300mmol), and further charged with 300mL of toluene, 40mL of ethanol, and 40mmol of water. After three nitrogen replacements, Pd (PPh) was added₃)₄(1.1g, 1mmol) and then heated to 110 ℃ for reaction overnight, with TLC showing completion of the reaction. Toluene was concentrated, water was added and extraction was performed with DCM, and the organic phase was collected, concentrated and then stirred with silica gel to obtain compound A88-1(31.62g, yield 85%) by silica gel column chromatography.

Preparation of Compound A88

Potassium carbonate (12.42g, 90mmol) is weighed, dissolved in 20mL of water, added to a 250mL round-bottom flask, compound A88-1(11.16g, 30mmol) and 2- (3-boronic acid pinacol ester group) phenyl-4, 6-diphenyl-1, 3, 5-triazine (13.0g, 30mmol) are weighed, added to the system, then dioxane 150mL is added, and after the addition, Pd is added₂(dba)₃(0.37g, 0.05mmol) and Sphos (0.37g, 1.02 mmol). The nitrogen was replaced three times, the reaction was heated to reflux under nitrogen with stirring overnight, and TLC showed completion of the reaction. Cooled to room temperature and the precipitated white solid was filtered. Heating with 4L toluene under reflux for dissolving, performing reduced pressure column chromatography and filtering, collecting filtrate, concentrating, and concentratingCrystallization gave compound A88 as a white solid (11.03g, 57% yield). Calculated molecular weight: 645.23, found C/Z: 645.2.

Synthesis example 10

Synthesis of Compound A92

Preparation of Compound A92-1

M10(30.8g, 100mmol) was added to a 500mL three-necked flask, dissolved in 280mL of toluene, 40mL of ethanol was added, phenylboronic acid (14.64g, 120mmol) and potassium carbonate (41.4g, 300mmol) were weighed into the three-necked flask, and 40mL of water was measured and added to the system. After three nitrogen replacements, Pd (PPh) was added₃)₄(0.56g, 0.5mmol) and then heated to 108 ℃ until the M10 reaction is complete. Toluene was concentrated, water was added and extraction was performed with DCM, and the organic phase was collected, concentrated and then stirred with silica gel to obtain compound A92-1(22.7g, yield 74%) by silica gel column chromatography.

Preparation of Compound A92

Compound A92-1(9.21g, 30mmol), potassium carbonate (12.42g, 90mmol) and A92-2(13.8g, 30mmol) were added to a flask containing dioxane, water (150mL:20mL), nitrogen gas was replaced with stirring at room temperature, and Pd was added₂(dba)₃(0.37g, 0.05mmol) and Sphos (0.37g, 1.02 mmol). After the addition was complete, the reaction was heated to reflux under nitrogen with stirring overnight and TLC showed completion of the reaction. Cooled to room temperature and the precipitated white solid was filtered. The resulting solution was dissolved in 3L of toluene under reflux, subjected to column chromatography under reduced pressure and filtered, collected, concentrated and then recrystallized to obtain Compound A92(10.71g, yield 59%) as a white solid. Calculated molecular weight: 605.23, found C/Z: 605.2.

Synthesis example 11

Synthesis of Compound A103

Preparation of Compound A103-1

A500 mL three-necked flask was charged with M11(23.94g, 60mmol), pinacol diboron diboride (19.81g, 78mmol), and potassium acetate (24.84g, 180mmol) and then 300mL dioxane was added. After nitrogen substitution three times, 1' -bisdiphenylphosphinoferrocene palladium dichloride (1.31g, 1.8mmol) was added and the reaction was heated under reflux overnight, and TLC showed completion. Dioxane was concentrated, dissolved in 1000mL of DCM, filtered, the filtrate was collected, concentrated, added 250mL of ethanol, heated to 80 ℃ and boiled for half an hour, and then filtered and dried to give Compound A103-1(23.33g, 87% yield).

Preparation of Compound A103

Compound A103-1(13.41g, 30mmol), potassium carbonate (12.42g, 90mmol) and A103-2(11.46g, 30mmol) were charged into a flask containing dioxane, water (150mL:20mL), nitrogen gas was replaced with stirring at room temperature, and Pd was added₂(dba)₃(0.37g, 0.05mmol) and Sphos (0.37g, 1.02 mmol). After the addition was complete, the reaction was heated to reflux under nitrogen with stirring overnight and TLC showed completion of the reaction. Cooled to room temperature and the precipitated white solid was filtered. The resulting mixture was dissolved in 3L of toluene under reflux, subjected to column chromatography under reduced pressure and filtered, collected, concentrated, and then dissolved in 1000mL of xylene under reflux, followed by natural cooling to room temperature to recrystallize, to obtain Compound A103(12.61g, yield 63%) as a white solid. Calculated molecular weight: 667.26, found C/Z: 667.2.

Synthesis example 12

Synthesis of Compound A104

Compound M12(11.49g, 30mmol), K₂CO₃(12.42g, 90mmol) and A104-1(10.26g, 30mmol) were charged into a flask containing dioxane: water (150mL:20mL), nitrogen was replaced with stirring at room temperature, and Pd was rapidly added₂(dba)₃(0.37g, 0.05mmol) and Sphos (0.37g, 1.02 mmol). After the addition was complete, the reaction was heated to reflux under nitrogen with stirring overnight and TLC showed completion of the reaction. Cooled to room temperature and the precipitated white solid was filtered. Heating with 3L toluene under reflux for dissolving, performing column chromatography under reduced pressure while hot, filtering, collecting hot filtrate, and standingAfter standing overnight, a large amount of solid precipitated, which was filtered and the cake rinsed three times with n-hexane and dried under vacuum to give A104(11.22g, 58% yield). Calculated molecular weight: 645.29, found C/Z: 645.2.

Example 1

The embodiment provides an organic electroluminescent device, and the preparation method comprises the following steps:

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 anode in a vacuum chamber, and vacuumizing until the pressure is less than 10^-5Pa, performing vacuum evaporation on the anode layer film by using a multi-source co-evaporation method to obtain HI-3 as a hole injection layer, wherein the evaporation rate is 0.1nm/s, and the evaporation film thickness is 10 nm;

evaporating HT-4 on the hole injection layer in vacuum to serve as a first hole transport layer of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 40 nm;

evaporating HT-14 on the first hole transport layer in vacuum to serve as a second hole transport layer of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 10 nm;

a luminescent layer of the device is vacuum evaporated on the second hole transport layer, the luminescent layer comprises a main material and a dye material, the evaporation rate of the main material BFH-4 is adjusted to be 0.1nm/s, the evaporation rate of the dye BFD-4 is set in a proportion of 5%, and the total film thickness of evaporation is 20nm by using a multi-source co-evaporation method;

vacuum evaporating ET-17 on the luminescent layer to be used as a hole blocking layer of the device, wherein the evaporation rate is 0.1nm/s, and the total film thickness is 5 nm;

evaporating an electron transport layer on the hole blocking layer by using a multi-source co-evaporation method, adjusting the evaporation rate of the compound A1 to be 0.1nm/s, setting the proportion of the evaporation rate of the compound A1 to the evaporation rate of ET-57 to be 100%, and setting the total film thickness of evaporation to be 23 nm;

LiF with the thickness of 1nm 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 80nm is used as a cathode of the device.

Examples 2 to 12 and comparative examples 1 to 3 differ from example 1 only in that compound a1 was replaced with another compound, as specified in table 1.

The electron transport materials in comparative examples 1 to 3 have the following structures:

wherein D1 and D2 are detailed in patent KR1020190033218A, and D3 is detailed in patent KR 1020170111539A.

And (3) performance testing:

the driving voltage and current efficiency of the organic electroluminescent devices prepared in the examples and comparative examples were measured at the same brightness using a PR 750 type photoradiometer of Photo Research, a ST-86LA type brightness meter (photoelectric instrument factory of university of beijing) and a Keithley4200 test system. 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 1000cd/m²The current density is measured at the same time as the driving voltage; the ratio of the brightness to the current density is the current efficiency; the results of the performance tests are shown in table 1.

TABLE 1

As can be seen from Table 1, the organic electroluminescent devices of the above examples and comparative examples are different only in the electron transport material, and the other materials are the same, and the devices of the examples have higher current efficiency and lower driving voltage than the comparative examples, the current efficiency is 7.86-8.89 cd/A, and the driving voltage is 4.59-4.86V. The reason is presumably that the azabenzindolizine group contained in the compound of the invention has strong electron withdrawing capability and is beneficial to electron injection, and meanwhile, the compound in the embodiment is mainly structurally characterized in that 2 electron withdrawing groups (azabenzindolizine parent nucleus and Ar) are bridged through L to form an 'A-pi-A' structure or an 'A-A' structure, and the structure is beneficial to electron injection and migration, so that the device efficiency is improved.

In addition, Ar is connected with one side of a benzene ring of the azabenzoindolizine through L, so that the balance of the injection and transmission capabilities of electrons is facilitated, and the phenomenon that the efficiency of the device is reduced due to the fact that the electron injection capability is too large and the electron transmission capability is poor is avoided.

In addition, the compound is connected with a conjugated group Ar in an extended manner at a specific position of the azabenzoindolizine, so that the molecular weight can be increased, the glass transition temperature (Tg) and the evaporation temperature can meet the requirements of devices, and the compound also has good plane conjugation property, and the structure of the azabenzoindolizine has a larger structural plane, thereby being beneficial to the transmission of electrons.

The electron transport material D1 in comparative example 1 contains electron donating dibenzofuran group, and triazine group is connected to N hetero aromatic ring, which balances the electron withdrawing property of triazine group, and at the same time, connected to N hetero aromatic ring, so that the electron capturing ability of the material is reduced, which is not favorable for electron injection and migration, and the device performance is reduced.

The position of the N hetero on the parent nucleus group of the electron transport material D2 in comparative example 2 is different from that of the present invention, and two N exist on the five-membered ring, so that the polarity of the molecule becomes too large, which causes the scattering effect of the transferred electrons and the dipole of the molecule, and at the same time, the electron-donating dibenzofuran group is also contained, which is not favorable for the injection of electrons, and the device performance is reduced.

The parent nucleus of the electron transport material D3 in comparative example 3 only contains one N atom and contains an electron donating carbazole group, and the whole structure shows electron donating performance, which is also not beneficial to electron injection and transport, so that the performance of the device is reduced.

The present invention is illustrated in detail by the examples described above, but the present invention is not limited to the details described above, i.e., it is not intended that the present invention be implemented by relying on the details described above. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. A compound having a structure according to formula I;

the R is₁、R₂、R₃、R₄、R₅And R₆Each independently selected from any one of hydrogen, halogen, cyano, substituted or unsubstituted C1-C12 chain alkyl, substituted or unsubstituted C3-C12 cycloalkyl, substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted C3-C60 heteroaryl;

in the formula I, m is an integer of 0-3;

in the formula I, L is any one selected from a single bond, substituted or unsubstituted C6-C30 arylene, and substituted or unsubstituted C3-C30 heteroarylene;

in the formula I, Ar is any one of C6-C60 aryl substituted with an electron-withdrawing group and substituted or unsubstituted C3-C60 heteroaryl, and Ar is the electron-withdrawing group;

when the above groups have substituents, the substituents are respectively and independently selected from any one or at least two combinations of halogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 haloalkyl, C2-C10 alkenyl, C1-C6 alkoxy, C1-C6 thioalkoxy, carbonyl, carboxyl, nitro, cyano, amino, C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C60 monocyclic heteroaryl and C6-C30 condensed ring heteroaryl.

2. The compound of claim 1, wherein the compound has a structure of (2-1) to (2-6);

the R is₁、R₂、R₃、R₄、R₅、R₆M, L and Ar all have the same limitations as defined in claim 1.

3. A compound according to claim 1 or 2, wherein the electron-withdrawing group comprises any one or a combination of at least two of nitro, arylamino, cyano, halogen, phosphoxy, carbonyl and acyl groups, preferably halogen and/or cyano.

4. The compound of claim 1 or 2, wherein Ar is selected from any one of substituted or unsubstituted triazinyl, substituted or unsubstituted pyrimidyl, substituted or unsubstituted pyridyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted quinolyl, substituted or unsubstituted imidazolyl, C6 to C20 aryl substituted with cyano, and C6 to C20 aryl substituted with halogen.

5. The compound of claim 1 or 2, wherein L is selected from any one of a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted naphthyl group, and a substituted or unsubstituted anthracenyl group.

6. A compound according to claim 1 or 2, wherein R is₁、R₂、R₃、R₄、R₅And R₆Each independently selected from any one of hydrogen, phenyl, biphenyl, naphthyl, cyano, halogen, pyridyl, C1-C4 chain alkyl and C3-C6 cycloalkyl.

7. The compound of claim 1, wherein the compound has any one of the following structures A1-a 108:

8. use of a compound according to any one of claims 1 to 7 in an electronic device;

preferably, the electronic device includes an organic electroluminescent device, an optical sensor, a solar cell, a lighting element, an organic thin film transistor, an organic field effect transistor, an organic thin film solar cell, an information label, an electronic artificial skin sheet, a sheet-type scanner, or electronic paper, preferably an organic electroluminescent device;

preferably, the compound is used as an electron transport layer material of the organic electroluminescent device.

9. An organic electroluminescent device comprising a substrate, a first electrode, a second electrode, and at least one organic layer between the first electrode and the second electrode, wherein the organic layer comprises at least one compound according to any one of claims 1 to 7.

10. The organic electroluminescent device according to claim 9, wherein the organic layer comprises an electron transport layer containing at least one compound according to any one of claims 1 to 7.