阅读说明：本技术 一种化合物及其应用 (Compound and application thereof ) 是由 孙恩涛 方仁杰 刘叔尧 吴俊宇 于 2020-04-10 设计创作，主要内容包括：本发明涉及一种化合物及其应用,所述化合物具有式(1)所示的结构,该化合物以苯并呋喃并噻唑或者苯并噻吩并噻唑为母核,并通过桥联基团L连接特定的Ar基团,形成的化合物结构具有相对更强的缺电子性,因此有利于电子的注入。同时,本发明化合物中含有大共轭结构的缺电子基团使分子具有良好的平面共轭性,从而有利于提高电子的迁移率,因而分子整体表现出良好的电子注入和迁移性能。所以,当将本发明的化合物用作有机电致发光器件中的电子传输层材料时,可以有效提升器件中的电子注入和迁移效率,从而确保器件获得高发光效率、低启动电压的优异效果。(The invention relates to a compound and application thereof, wherein the compound has a structure shown in a formula (1), and the compound takes benzofurothiazole or benzothienothiazole as a parent nucleus and is connected with a specific Ar group through a bridging group L, so that the formed compound structure has relatively stronger electron deficiency property, and is favorable for electron injection. Meanwhile, the compound contains an electron-deficient group with a large conjugated structure, so that the molecule has good plane conjugation, the mobility of electrons is improved, and the molecule integrally shows good electron injection and migration performances. 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.)

1. A compound having a structure represented by formula (1);

in the formula (1), X is O or S;

in the formula (1), L is selected from substituted or unsubstituted C6-C50 arylene or substituted or unsubstituted C3-C50 heteroarylene;

in the formula (1), Ar is selected from any one of substituted or unsubstituted C10-C50 fused ring aryl, substituted or unsubstituted C3-C50 heteroaryl or cyano;

in the formula (1), n is an integer of 0-4;

in the formula (1), R is selected from any one of deuterium, halogen, C1-C10 chain alkyl, C3-C18 cycloalkyl, C2-C10 alkenyl, cyano, C1-C10 alkoxy, C2-C10 alkynyl, substituted or unsubstituted C6-C50 aryl and substituted or unsubstituted C3-C50 heteroaryl;

l, Ar and R, the substituted groups are respectively and independently selected from one or the combination of at least two of halogen, nitryl, cyano, hydroxyl, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 condensed ring heteroaryl.

2. The compound of claim 1, wherein the compound has any one of the structures represented by formulas (1-1) to (1-5);

the X, L, Ar, n and R have the same limitations as defined in claim 1.

3. A compound according to claim 1 or 2, wherein L is selected from substituted or unsubstituted C6-C30 arylene or substituted or unsubstituted C3-C30 heteroarylene, preferably substituted or unsubstituted C6-C30 arylene, further preferably substituted or unsubstituted phenylene.

4. A compound according to claim 1 or 2, wherein Ar is selected from cyano or substituted or unsubstituted C3-C30 heteroaryl, preferably cyano or substituted or unsubstituted C3-C30 electron deficient heteroaryl.

5. The compound of claim 1 or 2, wherein Ar is selected from cyano or any one of the groups represented by formula (2) to formula (5);

wherein the wavy line indicates the bond of the group;

in the formula (2), the Y₁-Y₆Each independently selected from CR_aOr N, and Y₁-Y₆At least one of them is N;

in the formula (3), Z₁-Z₅Each independently selected from CR_aN, O or S, and Z₁-Z₅At least one of N, O or S;

in the formula (4), W₁-W₈Each independently selected from CR_aOr N, and W₁-W₈At least one of them is N;

in the formula (5), Q₁-Q₇Each independently selected from CR_aN, O or S, and Q₁-Q₇At least one of which is N, O or S, preferably Q₁-Q₃At least one of N, O or S;

the R is_aEach independently selected from any one of hydrogen, halogen, nitryl, cyano, hydroxyl, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 fused ring heteroaryl.

6. A compound according to claim 1 or 2, wherein Ar is selected from cyano or any one of the following substituted or unsubstituted groups:

wherein the wavy line indicates the bond of the group;

preferably, Ar is selected from cyano or any one of the following substituted or unsubstituted groups:

wherein the wavy line indicates the bond of the group;

preferably, Ar is selected from cyano or substituted or unsubstituted triazinyl.

7. A compound according to claim 1 or 2, wherein n is 0 or 1;

preferably, R is selected from any one of C1-C10 chain alkyl, substituted or unsubstituted C6-C50 aryl and substituted or unsubstituted C3-C50 heteroaryl, and is preferably selected from any one of methyl, phenyl or spirofluorenyl.

8. The compound of claim 1 or 2, wherein the substituted groups in L, Ar and R are each independently selected from C6-C30 monocyclic aryl or C10-C30 fused ring aryl, preferably any one or a combination of at least two of phenyl, biphenyl, or naphthyl.

9. The compound of claim 1, wherein the compound has any one of the following structures C1-C68:

10. a compound according to any one of claims 1 to 9 for use in an organic electroluminescent device;

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

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

preferably, the organic layer comprises an electron transport layer comprising at least one compound according to any one of claims 1 to 9.

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.

The OLED light-emitting device with lower driving voltage, better light-emitting efficiency and longer service life is prepared, the performance of the OLED device is continuously improved, the structure and the manufacturing process of the OLED device are required to be innovated, and the photoelectric functional material in the OLED device is required to be continuously researched and innovated, so that the functional material with higher performance is 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 order to further satisfy the continuously increasing demand for the photoelectric properties of OLED devices and the energy saving demand of mobile electronic devices, new and efficient OLED materials need to be continuously developed, wherein the development of new electron transport materials with high electron injection capability and high mobility is of great significance.

Disclosure of Invention

An object of the present invention is to provide a compound, particularly a compound for an organic electroluminescent device, and more particularly, a compound used as an electron transport material for an organic electroluminescent device, which has high electron injection ability and electron mobility, and can improve current efficiency of the device and reduce driving 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 (1);

in the formula (1), X is O or S;

in the formula (1), L is selected from substituted or unsubstituted C6-C50 arylene or substituted or unsubstituted C3-C50 heteroarylene;

in the formula (1), Ar is selected from any one of substituted or unsubstituted C10-C50 fused ring aryl, substituted or unsubstituted C3-C50 heteroaryl or cyano;

in the formula (1), n is an integer of 0-4, such as 1, 2, 3, etc.;

in the formula (1), R is selected from any one of deuterium, halogen, C1-C10 chain alkyl, C3-C18 cycloalkyl, C2-C10 alkenyl, cyano, C1-C10 alkoxy, C2-C10 alkynyl, substituted or unsubstituted C6-C50 aryl and substituted or unsubstituted C3-C50 heteroaryl;

when n is an integer of 2-4, 2-4R groups exist in the formula (1), and the 2-4R groups can be the same group or different groups;

l, Ar and R, the substituted groups are respectively and independently selected from one or the combination of at least two of halogen, nitryl, cyano, hydroxyl, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 condensed ring heteroaryl. "monocyclic aryl" refers to aryl groups that do not contain fused groups, e.g., phenyl, biphenyl, terphenyl, are monocyclic aryl groups, "fused aryl" refers to fused aryl groups, e.g., naphthyl, anthryl, phenanthryl, and the like, monocyclic heteroaryl and fused ring heteroaryl are synonymous.

The groups listed in the above paragraph refer to the selection range of the substituent when the substituent exists in the "substituted or unsubstituted" group, and the "substituted or unsubstituted" group may be substituted with one substituent or a plurality of substituents, and when the substituent is a plurality of substituents, the substituent may be selected from different substituents, and when the expression mode in the invention is the same, the meanings are the same, and the selection ranges of the substituents are all as shown above and are not repeated.

In the present invention, the heteroatom of heteroaryl is generally referred to as N, O, S.

In the present invention, the expression of the "-" underlined loop structure indicates that the linking site is located at an arbitrary position on the loop structure where the linkage can be formed.

In the present invention, the carbon number of the C1-C10 chain alkyl group, C2-C10 alkenyl group, and C2-C10 alkynyl group may be C2, C3, C4, C5, C6, C7, C8, C9, C10, or the like; the carbon number of the C3-C18 cycloalkyl can be C4, C5, C6, C7, C8, C9, C10, C12, C16 and the like; the number of carbons of the C3-C10 cycloalkyl can be C4, C5, C6, C7, C8, C9 and the like; the carbon number of the C1-C10 alkoxy and C1-C10 thioalkoxy can be C2, C3, C4, C5, C6, C7, C8, C9, C10 and the like; the carbon number of the C6-C50 (arylene) group may be C8, C10, C12, C14, C16, C18, C20, C26, C28, C30, C32, C34, C36, C38, C40, C42, C46, C48, or the like; the carbon number of the C3-C50 (arylene) heteroaryl group may be C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, C30, C32, C34, C36, C38, C40, C42, C46, C48, etc.; the carbon number of the C6-C30 arylamino can be C8, C10, C12, C14, C16, C18, C20, C26, C28 and the like; the number of carbons of the C3-C30 heteroaryl amino group can be C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28 and the like; the number of carbons of the C6-C30 monocyclic aryl can be C8, C10, C12, C14, C16, C18, C20, C26, C28 and the like; the number of carbons of the C10-C30 condensed ring aryl can be C12, C14, C16, C18, C20, C26, C28 and the like; the C3-C30 monocyclic heteroaryl can have the carbon number of C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28 and the like; the number of carbons of the C6-C30 fused ring heteroaryl can be C8, C10, C12, C14, C16, C18, C20, C26, C28 and the like. The number of carbons is merely an example and is not limited to the above.

The compound of formula (1) of the present invention is a compound represented by formula (1) whereinIs a mother nucleus and is connected with a specific Ar group through a bridging group L, and the structure of the formed compound has relatively strong electron deficiency, thereby being beneficial to the injection of electrons. Meanwhile, the compound contains electron-deficient groups with large conjugated structures, so that molecules have good plane conjugation, and the mobility of electrons is 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.

In addition, the preparation process of the compound is simple and feasible, the raw materials are easy to obtain, and the compound is suitable for mass production and amplification.

The term "electron-deficient group" as used herein means a group in which the electron cloud density on an aromatic ring is reduced when the group substitutes for a hydrogen on the aromatic 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 Thomas H.Lowry and Kathelen Schueler Richardson, "mechanics and Theory In Organic Chemistry", New York,1987, 143-. 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 any one of the structures represented by formulae (1-1) to (1-5);

x, L, Ar, n and R all have the same meanings as in formula (1).

Preferably, L is selected from substituted or unsubstituted C6-C30 arylene or substituted or unsubstituted C3-C30 heteroarylene, preferably substituted or unsubstituted C6-C30 arylene, further preferably substituted or unsubstituted phenylene.

Preferably, Ar is selected from cyano or substituted or unsubstituted C3-C30 heteroaryl, preferably cyano or substituted or unsubstituted C3-C30 electron deficient heteroaryl. "Electron deficient heteroaryl" is intended to have the meaning of "electron deficient group" as defined above.

In a preferred technical scheme of the invention, the mother nucleus is connected with cyano or heteroaryl (especially electron-deficient heteroaryl) through a bridging group L, and the specific Ar is matched with the mother nucleus, so that the compound has stronger electron-deficiency property, is more beneficial to electron injection, further improves the electron injection and migration performance of the compound, and can further improve the performance of a device as an electron transport material.

Preferably, Ar is selected from cyano or any one of groups shown in formulas (2) to (5);

wherein the wavy line indicates the bond of the group;

in the formula (2), the Y₁-Y₆Each independently selected from CR_aOr N, andY₁-Y₆at least one of the terms is N, such as two, three, etc.;

in the formula (3), Z₁-Z₅Each independently selected from CR_aN, O or S, and Z₁-Z₅At least one of which is N, O or S, e.g., two, three, etc.;

in the formula (4), W₁-W₈Each independently selected from CR_aOr N, and W₁-W₈At least one of them is N, such as two, three, four, five, six, etc.;

in the formula (5), Q₁-Q₇Each independently selected from CR_aN, O or S, and Q₁-Q₇At least one of which is N, O or S, e.g., two, three, four, etc., preferably Q₁-Q₃At least one of N, O or S, e.g., both;

the R is_aEach independently selected from any one of hydrogen, halogen, nitryl, cyano, hydroxyl, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 fused ring heteroaryl. When at least two R are present in Ar_aWhen these are at least two R_aMay or may not be the same.

Preferably, Ar is selected from cyano or any one of the following substituted or unsubstituted groups:

wherein the wavy line indicates the bond of the group.

Preferably, Ar is selected from cyano or any one of the following substituted or unsubstituted groups:

wherein the wavy line indicates the bond of the group.

According to the invention, Ar is further preferably an electron-deficient group such as substituted or unsubstituted pyridine, pyrimidine, triazine, quinazoline and the like, and the electron-deficient groups are connected to a parent nucleus through a bridging group L to form a novel electron transmission material. Therefore, when the compound is used as an electron transport material of an organic electroluminescent device, the luminous efficiency of the device can be improved, and the driving voltage can be reduced.

Preferably, Ar is selected from cyano or substituted or unsubstituted triazinyl.

Preferably, n is 0 or 1.

Preferably, R is selected from any one of C1-C10 chain alkyl, substituted or unsubstituted C6-C50 aryl and substituted or unsubstituted C3-C50 heteroaryl, and is preferably selected from any one of methyl, phenyl or spirofluorenyl.

Preferably, L, Ar and R, the substituted groups are each independently selected from C6-C30 monocyclic aryl or C10-C30 fused ring aryl, preferably any one or at least two combinations of phenyl, biphenyl or naphthyl.

Preferably, the compound has any one of the following structures shown as C1 to C68:

the second purpose of the invention is to provide the compound described in the first purpose, and the compound is applied to an organic electroluminescent device.

Preferably, the compound is used as an electron transport material in 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 comprising at least one compound according to one of the objects.

The OLED device prepared by the compound has low starting voltage and high luminous efficiency, can meet the requirements of panel manufacturing enterprises on high-performance materials at present, and has better effect particularly when being used as an electron transmission material.

Specifically, one embodiment of the present invention provides an organic electroluminescent device including a substrate, and an anode layer, a plurality of light emitting functional layers, and a cathode layer sequentially formed on the substrate; the light-emitting functional layer comprises a hole injection layer, a hole transport layer, a light-emitting layer and an electron transport layer, wherein the hole injection layer is formed on the anode layer, the hole transport layer is formed on the hole injection layer, the cathode layer is formed on the electron transport layer, and the light-emitting layer is arranged between the hole transport layer and the electron transport layer; wherein the electron transport layer contains the compound of the general formula of the present invention represented by the above formula (1).

More specifically, the organic electroluminescent device will be described in detail.

The OLED device 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 a specific embodiment, 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), and aromatic amine derivatives as 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 not limited to, the combination of one or more of BFH-1 through BFH-17 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 electroluminescent device of the present invention includes 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 region may also be formed using the compound of the present invention for a multilayer structure including at least one 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、Cs₂CO₃、BaO、Na、Li、Ca。

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

the compound of formula (1) of the invention takes benzofuran thiazole or benzothiophene thiazole as a parent nucleus, and is connected with a specific Ar group through a bridging group L, so that the formed compound structure has relatively stronger electron deficiency, thereby being beneficial to the injection of electrons. Meanwhile, the compound contains electron-deficient groups with large conjugated structures, so that molecules have good plane conjugation, and the mobility of electrons is 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.

In addition, the preparation process of the compound is simple and feasible, the raw materials are easy to obtain, and the compound is suitable for mass production and amplification.

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.

Four representative synthetic routes for the compounds of formula (1) of the present invention are as follows:

the method comprises the following steps:

the first step is as follows: performing ring closure reaction on 2-bromophenylacetonitrile or derivatives thereof, chlorobenzaldehyde and sulfur powder under the catalysis of cuprous chloride and 1, 10-phenanthroline (1,10-phen) to generate an intermediate M1-1; the second step, the intermediate M1-1 reacts with the pinacol ester diboron to generate a boron ester intermediate M1-2; and in the third step, the intermediate M1-2 and various aryl heteroaryl chloride react through Suzuki coupling reaction to generate a target product Cx.

Wherein DMSO is dimethyl sulfoxide, L, Ar, R and n have the same meanings as in formula (1), and G represents halogen.

The second method comprises the following steps:

the first step is as follows: performing ring closing reaction on the chloro-2-bromophenylacetonitrile, various aryl heteroaryl aldehydes and sulfur powder under the catalysis of cuprous chloride and 1, 10-phenanthroline to generate an intermediate M2-1; the second step, the intermediate M2-1 reacts with the pinacol ester diboron to generate a boron ester intermediate M2-2; and in the third step, the intermediate M2-2 and various aryl heteroaryl chloride react through Suzuki coupling reaction to generate a target product Cx.

Wherein DMSO is dimethyl sulfoxide, L, Ar, R and n have the same meanings as in formula (1), and G represents halogen.

The third method comprises the following steps:

the first step is as follows: coupling reaction of 2-amido-3-bromo benzofuran or its derivative and chlorobenzoyl chloride to produce intermediate M3-1; in the second step, the intermediate M3-1 is subjected to ring closing reaction under the action of phosphorus pentasulfide and sodium hydroxide to generate an intermediate M3-2; thirdly, reacting the intermediate M3-2 with pinacol diboron to generate a boron ester intermediate M3-3; in the fourth step, the intermediate M3-3 and various aryl heteroaryl chloride react through Suzuki coupling reaction to generate a target product Cx.

Wherein L, Ar, R and n have the same meanings as in formula (1), and G represents a halogen.

The method four comprises the following steps:

the first step is as follows: coupling reaction of chloro-2-amino-3-bromo benzofuran and substituted benzoyl chloride to produce intermediate M4-1; in the second step, the intermediate M4-1 is subjected to ring closing reaction under the action of phosphorus pentasulfide and sodium hydroxide to generate an intermediate M4-2; thirdly, reacting the intermediate M4-2 with pinacol diboron to generate a boron ester intermediate M4-3; in the fourth step, the intermediate M4-3 and various aryl heteroaryl chloride react through Suzuki coupling reaction to generate a target product Cx.

Wherein L, Ar, R and n have the same meanings as in formula (1), and G represents a halogen.

The following synthesis examples provide specific methods for synthesizing compounds, and the basic chemical materials used for various chemicals such as ethyl acetate, sodium sulfate, toluene, tetrahydrofuran, dichloromethane, acetic acid, potassium carbonate, etc. are commercially available from Shanghai Tantake technology, Inc. and Xilongchemical, Inc. The mass spectrometer used for determining the following compounds was a ZAB-HS type mass spectrometer measurement (manufactured by Micromass, UK).

Synthesis example 1:

synthesis of Compound C5

(1) Preparation of Compound 1-1

2-bromo-5-chlorobenzonitrile (229g, 1mol), p-cyanobenzaldehyde (262g, 2mol), sulfur powder (384g, 1.5mol), and potassium carbonate (138g, 1mol) were dissolved in a flask containing 25L of dimethyl sulfoxide at room temperature, nitrogen gas was replaced, and cuprous chloride (20g, 0.2mol) and 1, 10-phenanthroline (36g, 0.2mol) were added with stirring. After the addition, the mixture is heated to 120 ℃ under nitrogen atmosphere and stirring for reaction for 30 hours, and the TLC detection reaction is finished. Cooling to room temperature, pouring the reaction solution into a large amount of water, filtering the precipitated solid, washing with water, washing with ethanol and drying in the air. The resulting crude product was purified by column chromatography to give compound 1-1(201g, 61%).

(2) Preparation of Compounds 1-2

Compound 1-1(163g, 0.5mmol), pinacol diboron ester (190g, 0.75mol) and potassium acetate (147g, 1.5mol) were charged into a flask containing 1, 4-dioxane (3L), and after replacing nitrogen with stirring at room temperature, palladium acetate (2.24g, 10mmol) and 2-dicyclohexylphosphine-2 ',6' -dimethoxybiphenyl (SPhos, 8.2g, 20mmol) were added. After the addition was complete, the reaction was refluxed with stirring for 12 hours, and the end of the reaction was monitored by TLC. The 1, 4-dioxane was removed by rotary evaporation, the mixture was separated with water and dichloromethane, the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 1-2(167g, yield 80%).

(3) Preparation of Compound C5

Compounds 1-2(7.5g, 18mmol), 2-bromo-9, 9-spirobifluorene (7.1g, 18mmol), potassium carbonate (7.45g, 54mmol) and [1,1' -bis (diphenylphosphino) ferrocene]Palladium dichloride (pd) (dppf) Cl₂132mg, 0.18mmol) was added to a flask containing 100mL tetrahydrofuran and 25mL water, the nitrogen was replaced and the reaction was heated to reflux under nitrogen for 8 hours and TLC indicated completion of the reaction. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to give compound C5(8.8g, yield 81%). Calculated molecular weight: 606.12, found C/Z: 606.1.

synthesis example 2:

synthesis of Compound C19

(1) Preparation of Compound 2-1

2-Bromophenylacetonitrile (195g, 1mol), 3-chlorobenzaldehyde (280g, 2mol), sulfur powder (384g, 1.5mol), and potassium carbonate (138g, 1mol) were dissolved in a flask containing 25L of dimethyl sulfoxide at room temperature, nitrogen was replaced, and cuprous chloride (20g, 0.2mol) and 1, 10-phenanthroline (36g, 0.2mol) were added with stirring. After the addition, the mixture is heated to 120 ℃ under nitrogen atmosphere and stirring for reaction for 24 hours, and the TLC detection reaction is finished. Cooling to room temperature, pouring the reaction solution into a large amount of water, filtering the precipitated solid, washing with water, washing with ethanol and drying in the air. The resulting crude product was purified by column chromatography to give compound 2-1(177g, 62%).

(2) Preparation of Compound 2-2

Compound 2-1(143g, 0.5mmol), pinacol diboron ester (190g, 0.75mol) and potassium acetate (147g, 1.5mol) were charged into a flask containing 1, 4-dioxane (3L), and after replacing nitrogen with stirring at room temperature, palladium acetate (2.24g, 10mmol) and SPhos (8.2g, 20mmol) were added. After the addition was complete, the reaction was refluxed with stirring for 12 hours, and the end of the reaction was monitored by TLC. The 1, 4-dioxane was removed by rotary evaporation, and the mixture was separated with water and dichloromethane, and the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 2-2(153g, yield 81%).

(3) Preparation of Compound C19

The compound 2-2(6.8g, 18mmol), 2-chloro-3-phenylquinoxaline 4.3g, 18mmol, potassium carbonate (7.45g, 54mmol), pd (dppf) Cl₂(132mg, 0.18mmol) was added to a flask containing 100mL tetrahydrofuran and 25mL water, the nitrogen was replaced and the reaction was heated to reflux under nitrogen for 10 hours and TLC indicated completion of the reaction. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to give compound C19(7.3g, yield 86%). Calculated molecular weight: 471.09, found C/Z: 471.1.

synthesis example 3:

synthesis of Compound C31

(1) Preparation of Compound 3-1

2-bromo-4-chlorobenzonitrile (229g, 1mol), benzaldehyde (212g, 2mol), sulfur powder (384g, 1.5mol) and potassium carbonate (138g, 1mol) were dissolved in a flask containing 25L of dimethyl sulfoxide at room temperature, nitrogen gas was replaced, and cuprous chloride (20g, 0.2mol) and 1, 10-phenanthroline (36g, 0.2mol) were added with stirring. After the addition, the mixture is heated to 120 ℃ under nitrogen atmosphere and stirred for reaction for 25 hours, and the TLC detection reaction is finished. Cooling to room temperature, pouring the reaction solution into a large amount of water, filtering the precipitated solid, washing with water, washing with ethanol and drying in the air. The resulting crude product was purified by column chromatography to give compound 3-1(195g, 65%).

(2) Preparation of Compound 3-2

Compound 3-1(151g, 0.5mmol), pinacol diboron ester (190g, 0.75mol) and potassium acetate (147g, 1.5mol) were charged into a flask containing 1, 4-dioxane (3L), and after replacing nitrogen with stirring at room temperature, palladium acetate (2.24g, 10mmol) and SPhos (8.2g, 20mmol) were added. After the addition was complete, the reaction was refluxed with stirring for 10 hours, and the end of the reaction was monitored by TLC. The 1, 4-dioxane was removed by rotary evaporation, and the mixture was separated with water and dichloromethane, and the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 3-2(157g, yield 82%).

(3) Preparation of Compound C31

Compounds of 3-2(7.1g, 18mmol), 2- (4-bromophenyl) -4, 6-diphenyl-1, 3, 5-triazine (7.0g, 18mmol), potassium carbonate (7.45g, 54mmol), pd (dppf) Cl₂(132mg, 0.18mmol) was added to a flask containing 100mL tetrahydrofuran and 25mL water, the nitrogen was replaced and the reaction was heated to reflux under nitrogen for 9 hours and TLC indicated completion of the reaction. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to give compound C31(8.9g, yield 86%). Calculated molecular weight: 574.13, found C/Z: 574.1.

synthesis example 4:

synthesis of Compound C58

(1) Synthesis of Compound 4-1

2-bromo-6-chlorobenzonitrile (229g, 1mol), benzaldehyde (212g, 2mol), sulfur powder (384g, 1.5mol) and potassium carbonate (138g, 1mol) were dissolved in a flask containing 25L of dimethyl sulfoxide at room temperature, nitrogen gas was replaced, and cuprous chloride (20g, 0.2mol) and 1, 10-phenanthroline (36g, 0.2mol) were added with stirring. After the addition, the mixture was heated to 120 ℃ under nitrogen atmosphere with stirring for 28 hours, and the reaction was completed by TLC. Cooling to room temperature, pouring the reaction solution into a large amount of water, filtering the precipitated solid, washing with water, washing with ethanol and drying in the air. The resulting crude product was purified by column chromatography to give compound 4-1(190g, 63%).

(2) Preparation of Compound 4-2

Compound 4-1(151g, 0.5mmol), pinacol diboron ester (190g, 0.75mol) and potassium acetate (147g, 1.5mol) were charged into a flask containing 1, 4-dioxane (3L), and after replacing nitrogen with stirring at room temperature, palladium acetate (2.24g, 10mmol) and SPhos (8.2g, 20mmol) were added. After the addition was complete, the reaction was refluxed with stirring for 12 hours, and the end of the reaction was monitored by TLC. The 1, 4-dioxane was removed by rotary evaporation, the mixture was separated with water and dichloromethane, the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 4-2(123g, yield 81%).

(3) Preparation of Compound 4-3

The compound 2-chloro-4-phenylquinazoline (24g, 0.1mol), 3-chloro-phenylboronic acid (15.6g, 0.1mol), potassium carbonate (41g, 0.3mol), pd (dppf) Cl₂(732mg, 1mmol) was added to a flask containing tetrahydrofuran/water 400mL/100mL, the reaction was refluxed for 8 hours under nitrogen while displacing nitrogen, and TLC showed completion of the reaction. Cooling to room temperature, separating, extracting water phase with ethyl acetate, combining organic phases, drying with anhydrous sodium sulfate, and purifying by column chromatography to obtain compound 4-3(21g, 65%).

(4) Preparation of Compound C58

Compounds 4-2(7.1g, 18mmol), 4-3(5.7g, 18mmol), potassium carbonate (7.45g, 54mmol), tris (dibenzylacetone) dipalladium (0) (pd)₂(dba)₃367mg, 0.4mmol), Sphos (328mg, 0.8mmol) were added to a flask containing 1, 4-dioxane/water 150mL/15mL, the reaction was replaced with nitrogen and heated under nitrogen at reflux for 15 hours, and TLC showed completion of the reaction. Filtering to obtain solid, rinsing with water and ethanol, drying, and separating by column chromatographyIsolation and purification gave compound C58(8.3g, 85% yield). Calculated molecular weight: 547.12, found C/Z: 547.1.

synthesis example 5:

synthesis of Compound C66

(1) Preparation of Compound 5-1

Dissolving 2-amino-3-benzofuran (211g, 1mol) and triethylamine (202g, 2mol) in a flask containing 2L dichloromethane at room temperature, cooling to 0 ℃ in an ice bath, dropwise adding p-chlorobenzoyl chloride (191g, 1.1mol) into the system, keeping the temperature not higher than 10 ℃ in the dropwise adding process, naturally raising the temperature to room temperature after the dropwise adding, stirring for reacting overnight, and detecting by TLC to finish the reaction. The reaction was quenched by addition of water, the layers were separated, the organic phase was dried over anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation under reduced pressure. The crude product 5-1 was used directly in the next reaction.

(2) Preparation of Compound 5-2

The intermediate compound 5-1 obtained in the above reaction, phosphorus pentasulfide (333g, 1.5mol) and sodium hydroxide (40g, 1mol) were added to a flask containing DMF (3L), the reaction system was heated to 80 ℃ for 10 hours, and the end of the reaction was monitored by TLC. Cooling to room temperature, pouring the reaction system into a large amount of water, filtering the precipitated solid, washing with water and ethanol respectively, and drying in the air. The resulting crude product was purified by column chromatography to give compound 5-2(162g, yield 57%).

(3) Preparation of Compound 5-3

Compound 5-2(143g, 0.5mmol), pinacol diboron ester (190g, 0.75mol) and potassium acetate (147g, 1.5mol) were charged into a flask containing 1, 4-dioxane (3L), and after replacing nitrogen with stirring at room temperature, palladium acetate (2.24g, 10mmol) and SPhos (8.2g, 20mmol) were added. After the addition was complete, the reaction was refluxed with stirring for 10 hours, and the end of the reaction was monitored by TLC. The 1, 4-dioxane was removed by rotary evaporation, the mixture was separated with water and dichloromethane, the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 5-3(151g, yield 80%).

(4) Preparation of Compound C66

Compounds of 5-3(6.8g, 18mmol), 2-chloro-4-phenyl-6- (1-naphthyl) -1,3, 5-triazine (5.7g, 18mmol), potassium carbonate (7.5g, 54mmol), pd (dppf) Cl₂(132mg, 0.18mmol) was added to a flask containing 100mL tetrahydrofuran and 25mL water, the nitrogen was replaced and the reaction was heated to reflux under nitrogen for 15 hours and TLC indicated completion of the reaction. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to give compound C66(7.4g, yield 77%). Calculated molecular weight: 532.14, found C/Z: 532.1.

example 1

The embodiment provides an organic electroluminescent device and a preparation method thereof, which specifically comprise 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 the compounds C5 and ET-57 of the invention on the hole blocking layer by a multi-source co-evaporation method to be used as an electron transport layer, adjusting the evaporation rate of the compound C5 to be 0.1nm/s, setting the evaporation rate to be 100 percent of the evaporation rate of the ET-57 (the evaporation rate of the compounds C5 and ET-57 is 1:1), and setting the total film thickness of the evaporated film 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 2-11 differ from example 1 only in that compound C5 was replaced by another compound, as specified in table 1.

Comparative example 1

The difference from example 1 is that compound C5 is replaced by compound D-1 (see in detail WO2015076600A 1).

Comparative example 2

The difference from example 1 is that compound C5 is replaced by compound D-2 (see patent KR1020150103921A for details).

Comparative example 3

The difference from example 1 is that compound C5 was replaced by the aforementioned compound ET-9.

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; brightness of lightThe ratio of the current density 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, under the condition that other materials in the organic electroluminescent device structure are the same, the organic electroluminescent device provided by the embodiment of the present invention has high current efficiency and low driving voltage, wherein the current efficiency is 8.51 to 9.21cd/a, and the driving voltage is 3.72 to 4.14V.

The driving voltage of the device using the compound D-1 of comparative example 1 as an electron transporting material was 5.16V, the current efficiency was 7.01cd/A, and the difference in performance was large compared with the device of example. The reason is probably that the electron-deficient group of the compound of the invention is matched with the electron-deficient group of triazine, pyrimidine, quinazoline and the like through bridging to form a new electron-transporting material. Compared with the compound formed by heterocyclic pyrrole and electron-deficient group, the pyrrole is an electron-donating group, the whole molecule is an electron donor-electron acceptor structure molecule, the electron affinity of the compound is obviously reduced compared with the electron transport material of the formula (1), and the injection capability of electrons is obviously inferior to that of the compound. And thus its voltage is relatively high and current efficiency is relatively low.

Comparative example 2 the compound D-2 was used as an electron transporting material, and although D-2 also contained a triazine group, the molecule thereof as a whole was also an electron donor-electron acceptor structure which was not suitable as an electron transporting material to be used in a device structure, similarly to comparative example 1, and therefore the device performance of comparative example 2 was significantly inferior to that of the examples.

Comparative example 3 using the aforementioned compound ET-9 as an electron transport material, since ET-9 has only one triazine electron deficient group in the molecule, the electron affinity thereof is relatively poor compared to the compound of the present invention, and thus the electron injecting ability thereof is relatively weak, resulting in a device using it as an electron transport material having a relatively high voltage and a relatively low current efficiency.

Therefore, the new electron transport material formed by bridging a specific Ar group and matching the electron-deficient group of the compound benzofuran (or thiophene) thiazole has higher electron injection and migration performances, so that the device has higher current efficiency and lower driving voltage.

The experimental data show that the novel organic material is an organic luminescent functional material with good performance as an electron transport material of an organic electroluminescent device, and has wide application prospect.

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.