阅读说明：本技术 一种化合物及其应用 (Compound and application thereof ) 是由 黄金华 王志鹏 高文正 张维宏 黄鑫鑫 于 2020-06-30 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I所示的结构,首先在萘环的1-位上引入取代基-L～(1)-Ar～(1),不仅能够调节1-位的位阻大小,还能有效调控分子的扭曲度以降低分子结晶性；其次,在萘环2-位的N原子上取代特定结构的片段,与萘环结构、-L～(1)-Ar～(1)和-L～(2)-Ar～(2)搭配,能够有效调控分子整体的立体结构,提高分子的堆积致密度,优化LUMO和HOMO能级,改善分子空穴传输能力,同时能够有效改善分子的折光性能,从而使利用其所制备的器件性能进一步提高。本发明的化合物作为有机电致发光器件的电子阻挡层材料时,能够有效提高发光效率、降低驱动电压并延长器件的使用寿命。(The invention relates to a compound and application thereof, wherein the compound has a structure shown in formula I, and firstly, a substituent-L is introduced to 1-position of naphthalene ring 1 ‑Ar 1 Not only can adjust the steric hindrance of the 1-position, but also can effectively adjust and control the torsion resistance of the molecule to reduce the moleculeCrystallinity; secondly, a fragment with a specific structure is substituted on the N atom at the 2-position of the naphthalene ring, and the naphthalene ring structure, -L 1 ‑Ar 1 and-L 2 ‑Ar 2 The matching can effectively regulate and control the integral three-dimensional structure of molecules, improve the accumulation density of the molecules, optimize the LUMO and HOMO energy levels, improve the hole transmission capability of the molecules, and effectively improve the refractive property of the molecules, thereby further improving the performance of devices prepared by utilizing the molecules. When the compound is used as an electron barrier layer material of an organic electroluminescent device, the compound can effectively improve the luminous efficiency, reduce the driving voltage and prolong the service life of the device.)

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

in the formula I, Ar is¹And Ar²Each independently selected from any one of substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl;

in the formula I, L is¹And L²Each independently selected from any one of a single bond, a substituted or unsubstituted C6-C60 arylene, a substituted or unsubstituted C3-C60 heteroarylene;

in the formula I, theL³Any one selected from substituted or unsubstituted C6-C60 arylene, substituted or unsubstituted C3-C60 heteroarylene;

in the formula I, R is²Any one selected from hydrogen, halogen, carboxyl, cyano, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C1-C12 alkoxy, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C2-C12 alkenyl, substituted or unsubstituted C2-C12 alkynyl, C1-C20 alkylcarbonyl, substituted or unsubstituted C6-C60 aryl and C3-C60 heteroaryl;

Ar¹、Ar²、L¹、L²、L³and R²Wherein, the substituted groups are respectively and independently selected from any one or at least two combinations of halogen, cyano, carboxyl, amine, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C20 alkylcarbonyl, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl and C3-C30 heteroaryl.

2. The compound of claim 1, wherein the compound has a structure represented by formula II;

in the formula II, Ar is¹、Ar²、L¹、L²、L³And R²All having the same limitations as in formula I.

3. The compound of claim 1, wherein L is³Is selected from substituted or unsubstituted arylene groups of C6-C60, preferably substituted or unsubstituted arylene groups of C6-C30.

4. The compound of claim 1, wherein the compound has a structure according to formula III;

in the formula III, R is¹Any one selected from hydrogen, halogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl and C3-C30 heteroaryl, preferably hydrogen;

in the formula III, Ar is¹、Ar²、L¹、L²And R²All having the same limitations as in formula I.

5. The compound of claim 4, wherein the compound has a structure according to formula IV;

in the formula IV, R is¹、Ar¹、Ar²、L¹、L²And R²All having the same limitations as in formula III.

6. The compound of any one of claims 1-5, wherein Ar is Ar¹And Ar²Each independently selected from any one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl.

7. The compound of any one of claims 1-5, wherein Ar is Ar¹Any one selected from the following substituted or unsubstituted groups:

wherein the wavy line mark represents the access bond of the group.

8. The compound of any one of claims 1-5, wherein Ar is Ar²Any one selected from the following substituted or unsubstituted groups:

wherein the wavy line mark represents an access bond of the group;

preferably, Ar is²Any one selected from the following substituted or unsubstituted groups:

9. a compound according to any one of claims 1 to 5 wherein L is¹And L²Each independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene group, a substituted or unsubstituted C3-C30 heteroarylene group, preferably a single bond or a substituted or unsubstituted C6-C30 arylene group, further preferably a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted naphthylene group;

preferably, said R is²Selected from hydrogen.

10. The compound of claim 1, wherein the compound has any one of the structures shown as P1-P208 below:

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

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

12. An organic electroluminescent device comprising a first electrode, a second electrode and at least one organic layer interposed between the first electrode and the second electrode, the organic layer containing at least one compound according to any one of claims 1 to 10;

preferably, the organic layer comprises an electron blocking layer comprising at least one compound according to any one of claims 1 to 10.

Technical Field

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

Background

In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them well suited for fabrication on flexible substrates, allowing for the design and production of aesthetically pleasing and crunchy optoelectronic products, with unparalleled advantages over inorganic materials. Examples of such organic optoelectronic devices include Organic Light Emitting Diodes (OLEDs), organic field effect transistors, organic photovoltaic cells, organic sensors, and the like. Among them, OLEDs have been developed particularly rapidly, and have been commercially successful in the field of information display. The OLED can provide three colors of red, green and blue with high saturation, and a full-color display device manufactured by using the OLED does not need an additional backlight source and has the advantages of colorful, light, thin and soft color and the like.

The core of the OLED device is a thin film structure containing various organic functional materials. 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. When electricity is applied, electrons and holes are injected, transported to the light emitting region, and recombined therein, respectively, thereby generating excitons and emitting light.

People have developed various organic materials, and the organic materials are combined with various peculiar device structures, so that the carrier mobility can be improved, the carrier balance can be regulated and controlled, the electroluminescent efficiency can be broken through, and the attenuation of the device can be delayed. For quantum mechanical reasons, common fluorescent emitters mainly utilize singlet excitons generated when electrons and holes are combined to emit light, and are still widely applied to various OLED products. Some metal complexes, such as iridium complexes, can emit light using both triplet excitons and singlet excitons, which are called phosphorescent emitters, and the energy conversion efficiency can be increased by up to four times as compared with conventional fluorescent emitters. The thermal excitation delayed fluorescence (TADF) technology can still effectively utilize triplet excitons to achieve higher luminous efficiency without using a metal complex by promoting the conversion of triplet excitons to singlet excitons. Thermal excitation sensitized fluorescence (TASF) technology also achieves higher luminous efficiency by sensitizing the emitter by energy transfer using TADF-like materials.

As OLED products gradually enter the market, there are increasingly higher requirements on the performance of such products. The currently used OLED materials and device structures cannot completely solve the problems of OLED product efficiency, service life, cost and the like.

Therefore, there is a need in the art to develop an organic electroluminescent material that can improve the light emitting efficiency of the device, reduce the driving voltage, and prolong the lifetime.

Disclosure of Invention

It is an object of the present invention to provide a compound, especially an electron blocking layer material, for improving the device performance, such as increasing the light emitting efficiency, reducing the driving voltage, and prolonging the lifetime.

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, Ar is¹And Ar²Each independently selected from any one of substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl;

in the formula I, L is¹And L²Each independently selected from any one of a single bond, a substituted or unsubstituted C6-C60 arylene, a substituted or unsubstituted C3-C60 heteroarylene;

in the formula I, L is³Any one selected from substituted or unsubstituted C6-C60 arylene, substituted or unsubstituted C3-C60 heteroarylene;

in the formula I, R is²Any one selected from hydrogen, halogen, carboxyl, cyano, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C1-C12 alkoxy, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C2-C12 alkenyl, substituted or unsubstituted C2-C12 alkynyl, C1-C20 alkylcarbonyl, substituted or unsubstituted C6-C60 aryl and C3-C60 heteroaryl;

Ar¹、Ar²、L¹、L²、L³and R²Wherein, the substituted groups are respectively and independently selected from any one or at least two combinations of halogen, cyano, carboxyl, amine, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C20 alkylcarbonyl, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl and C3-C30 heteroaryl. Preferably, the substituents are selected from C6-C30 aryl groups including, but not limited to, phenyl, naphthyl, and the like.

The above "substituted or unsubstituted" group may be substituted with one substituent, or may be substituted with a plurality of substituents, and when a plurality of substituents are present, different substituents may be selected from different substituents.

In the present invention, the expression of chemical elements includes the concept of chemically identical isotopes, for example, hydrogen (H) includes¹H (protium, or written as H),²H (deuterium, or denoted as D), etc.; carbon (C) then comprises¹²C、¹³C and the like.

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

In the present invention, the expression "-" denotes a loop structure, and indicates that the linking site is located at an arbitrary position on the loop structure where the linking site can be bonded.

In the present invention, the C6-C60 aryl group includes C6-C60 monocyclic aryl group or C10-C60 fused ring aryl group, wherein monocyclic aryl group means that the aromatic ring exists as a single ring, no fusion exists, and includes, but is not limited to, phenyl, biphenyl, or terphenyl group; a fused ring aryl refers to a structure in which at least two aromatic rings are fused, including, but not limited to, naphthyl, anthryl, phenanthryl, fluorenyl, and the like.

In the present invention, the heteroaryl group of C3-C60 includes a monocyclic heteroaryl group of C3-C60 or a fused-ring heteroaryl group of C6-C30, wherein the monocyclic heteroaryl group means that the heteroaryl ring exists in the form of a single ring without fusion, including but not limited to pyridine, pyrimidine, triazine, or a group formed by connecting at least two thereof, etc.; fused heteroaryl refers to a fused ring aryl group containing a heteroatom, including but not limited to a dibenzofuran group, a dibenzothiophene group, or a carbazole group, and the like.

The C1-C20 chain alkyl group is preferably a C1-C10 chain alkyl group, more preferably a C1-C6 chain alkyl group, and examples thereof include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, n-octyl, n-pentyl, n-heptyl, n-nonyl, n-decyl and the like.

The above-mentioned C3-C20 cycloalkyl group is preferably cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl.

The above-mentioned C1-C12 alkoxy group is preferably methoxy; the above-mentioned C2-C12 alkenyl group is preferably vinyl; the above-mentioned C2-C12 alkynyl group is preferably ethynyl; the above-mentioned C1-C20 alkylcarbonyl group means R-CO-, wherein R represents C1-C20 alkyl.

The substituted or unsubstituted C6-C60 aryl group, preferably C6-C30 aryl group, is preferably selected from phenyl, biphenyl, terphenyl, naphthyl, anthryl, phenanthryl, indenyl, fluorenyl and derivatives thereof, fluoranthryl, triphenylene, pyrenyl, perylenyl, perylene, and the like,A group of the group consisting of a phenyl group and a tetracenyl group. The biphenyl group is selected from the group consisting of 2-biphenyl, 3-biphenyl, and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl and m-terphenyl-2-yl; the naphthyl group includes a 1-naphthyl group or a 2-naphthyl group; what is needed isThe anthracene group is selected from the group consisting of 1-anthracene group, 2-anthracene group, and 9-anthracene group; the fluorenyl group is selected from the group consisting of 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl and 9-fluorenyl; the fluorenyl derivative is selected from the group consisting of 9, 9-dimethylfluorene, 9-spirobifluorene and benzofluorene; the pyrenyl group is selected from the group consisting of 1-pyrenyl, 2-pyrenyl and 4-pyrenyl; the tetracene group is selected from the group consisting of 1-tetracene, 2-tetracene, and 9-tetracene.

The substituted or unsubstituted C3-C60 heteroaryl group, preferably C3-C30 heteroaryl group, preferably the heteroaryl group is furyl, thienyl, pyrrolyl, benzofuryl, benzothienyl, isobenzofuryl, indolyl, dibenzofuryl, dibenzothienyl, carbazolyl and derivatives thereof, wherein the carbazolyl derivative is preferably 9-phenylcarbazole, 9-naphthylcarbazole benzocarbazole, dibenzocarbazole, or indolocarbazole.

In the present invention, the numbers for the substitution sites on the naphthalene ring are as follows:

the invention provides a novel organic electroluminescent material, which is prepared by firstly introducing substituent-L on 1-position of naphthalene ring¹-Ar¹The size of the 1-position steric hindrance can be adjusted, and the molecular torsion resistance can be effectively adjusted to reduce the molecular crystallinity; secondly, substitution on the N atom in the 2-position of the naphthalene ringAnd naphthalene ring structure, -L¹-Ar¹and-L²-Ar²The matching can effectively regulate and control the integral three-dimensional structure of molecules, improve the accumulation density of the molecules, optimize the LUMO and HOMO energy levels, improve the hole transmission capability of the molecules, and effectively improve the refractive property of the molecules, thereby further improving the performance of devices prepared by utilizing the molecules.

When the compound is used as an electron barrier layer material of an organic electroluminescent device, the compound can effectively improve the luminous efficiency, reduce the driving voltage and prolong the service life of the device.

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.

Preferably, the compound has the structure shown in formula II;

in the formula II, Ar is¹、Ar²、L¹、L²、L³And R²All having the same selection ranges as in formula I.

Preferably, said L³Is selected from substituted or unsubstituted arylene groups of C6-C60, preferably substituted or unsubstituted arylene groups of C6-C30.

Preferably, the compound has the structure shown in formula III;

in the formula III, R is¹Any one selected from hydrogen, halogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl and C3-C30 heteroaryl, preferably hydrogen;

in the formula III, Ar is¹、Ar²、L¹、L²And R²All having the same selection ranges as in formula I.

Preferred L in the invention³The compound is a phenylene compound (namely a formula III), because the phenylene can regulate and control the energy levels of HOMO and LUMO of molecules, and because the structure size of the phenylene compound is proper, the crowding degree of the molecules can be effectively relieved, and meanwhile, the transmission performance of the material can be accurately regulated and controlled to match with a corresponding device, so that the performance of the device is further improved.

Preferably, the compound has the structure shown in formula IV;

in the formula IV, R is¹、Ar¹、Ar²、L¹、L²And R²All having the same selection range as in formula III.

The phenanthrene ring is further preferably substituted at the para position of the N atom (namely, the formula IV), and the para-position connection structure has better refractive property and hole transmission capability, so that the device performance is further improved.

Preferably, Ar is¹And Ar²Each independently selected from any one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl.

Preferably, Ar is¹Any one selected from the following substituted or unsubstituted groups:

wherein the wavy line mark represents the access bond of the group.

Further preferred in the present invention is Ar mentioned above¹Radicals, these radicals and naphthalene rings andand the matching is more beneficial to the improvement of the device performance.

Preferably said Ar²Any one selected from the following substituted or unsubstituted groups:

wherein the wavy line mark represents the access bond of the group.

Preferably, Ar is²Any one selected from the following substituted or unsubstituted groups:

further preferred in the present invention is Ar mentioned above²Radicals, these radicals and naphthalene rings andand the matching is more beneficial to the improvement of the device performance.

Preferably, said L¹And L²Each independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene group, a substituted or unsubstituted C3-C30 heteroarylene group, preferably a single bond or a substituted or unsubstituted C6-C30 arylene group, more preferably a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted naphthylene group.

Preferably, said R is²Selected from hydrogen.

Preferably, the compound has any one of the structures shown as P1-P208.

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

Preferably, the compound is used as an electron blocking layer material in the organic electroluminescent device.

It is a further object of the present invention to provide an organic electroluminescent device comprising a first electrode, a second electrode and at least one organic layer interposed between the first electrode and the second electrode, the organic layer containing at least one compound according to one of the objects.

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

The compound of the invention can be applied to organic electroluminescent devices, and can also be applied to other types of organic electronic devices, including organic field effect transistors, organic thin-film solar cells, information labels, electronic artificial skin sheets, sheet type scanners or electronic paper.

Specifically, another technical scheme 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 at least one of a hole injection layer, a hole transport layer, a light-emitting layer, an electron blocking layer and an electron transport layer, wherein the electron blocking layer contains at least one of the compounds.

The 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 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 have a multi-layer structure including at least one of a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), and an Electron Blocking Layer (EBL) using the compound of formula I according to the present invention.

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 including compounds shown below as HT-1 to HT-51; 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-51 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-51 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, the combination of one or more of BFD-1 through BFD-24 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 PH-1 to PH-85.

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

In one aspect of the invention, the electron transport layer material may be selected from, but is not limited to, the combination of one or more of ET-1 through ET-65 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:

the invention provides a novel organic electroluminescent material, which is prepared by firstly introducing substituent-L on 1-position of naphthalene ring¹-Ar¹The size of the 1-position steric hindrance can be adjusted, and the molecular torsion resistance can be effectively adjusted to reduce the molecular crystallinity; secondly, substitution on the N atom in the 2-position of the naphthalene ringAnd naphthalene ring structure, -L¹-Ar¹and-L²-Ar²The matching can effectively regulate and control the integral three-dimensional structure of molecules, improve the accumulation density of the molecules, optimize the LUMO and HOMO energy levels, improve the hole transmission capability of the molecules, and effectively improve the refractive property of the molecules, thereby further improving the performance of devices prepared by utilizing the molecules.

When the compound is used as an electron barrier layer material of an organic electroluminescent device, the compound can effectively improve the luminous efficiency, reduce the driving voltage and prolong the service life of the device, and the brightness of the organic electroluminescent device reaches 3000cd/m²The current efficiency is as high as 19.6cd/A and above, even more than 20cd/A, which is 8-19% higher than that of the compound in the prior art.

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.

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

wherein R is₂、L¹、L²、L³、Ar¹And Ar²Are all the same as the symbols in formula I; pd₂(dba)₃Representative of three(dibenzylacetone) dipalladium (0), IPr. HCl for 1, bis (2, diisopropylphenyl) imidurium chloride, NaOBu-t for sodium tert-butoxide, (t-Bu)₃P represents tri-tert-butylphosphine. The preparation of the compound of formula I of the present invention includes the above-mentioned methods, but is not limited to the above-mentioned methods, and the compound of formula I synthesized by other methods by those skilled in the art also belongs to the protection scope of the present invention.

More specifically, the present invention provides a specific synthesis method of a representative compound as exemplified by the following synthesis examples, in which the solvents and reagents used in the following synthesis examples, such as 3-bromo-9, 9-dimethylfluorene, 1, bis (2, diisopropylphenyl) imidazolium chloride, tris (dibenzylacetone) dipalladium (0), toluene, methanol, ethanol, tri-tert-butylphosphine, and other chemical reagents, are commercially available or custom-made from domestic chemical product markets, such as from national drug group reagent company, Sigma-Aldrich company, chlorothalocarb reagent company, and intermediates M1-M8, which are custom-made by reagent company. In addition, they can be synthesized by a known method by those skilled in the art.

Synthesis example 1: synthesis of Compound P2

In a 1000mL single-neck flask, 13.5g of M1, 16.5g of 9- (4-bromophenyl) phenanthrene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder M1-1.

In a 1000mL single-neck flask, 26g of M1-1, 11.5g of 4-bromo-biphenyl, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction solution, concentrating the organic phase, and adding methanolStirring for 1h and suction filtration gave P2 as a pale yellow powder.

M/Z theoretical value: 673; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 674.

synthesis example 2: synthesis of Compound P10

The synthesis method of M1-1 was the same as in Synthesis example 1.

In a 1000mL single-neck flask, 26g of M1-1, 13.6g of 3-bromo-9, 9-dimethylfluorene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and filtering to obtain light yellow powder P10.

M/Z theoretical value: 713; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 714.

synthesis example 3: synthesis of Compound P26

In a 1000mL single-neck flask, 13.5g of M1, 16.5g of 9- (3-bromophenyl) phenanthrene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder M1-2.

In a 1000mL single-neck flask, 23.5g of M1-2, 12.3g of 2-bromodibenzofuran, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene, 15g of t-butylAnd vacuumizing sodium alkoxide (NaOBu-t), changing nitrogen for 3 times, and heating to 110 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and filtering to obtain light yellow powder P26.

M/Z theoretical value: 687; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 688.

synthesis example 4: synthesis of Compound P61

In a 1000mL single-neck flask, 11g of M2, 16.5g of 9- (3-bromophenyl) phenanthrene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder M2-1.

In a 1000mL single-neck flask, 26g of M2-1, 13.6g of 2-bromo-9, 9-dimethylfluorene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and filtering to obtain light yellow powder P61.

M/Z theoretical value: 663; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 664.

synthesis example 5: synthesis of Compound P142

In a 1000mL single-neck flask, 16.8g of M3, 16.5g of 9- (3-bromophenyl) -phenanthrene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder M3-1.

In a 1000mL single neck flask, 29.5g of M3-1, 13.5g of 3-bromo-9, 9-dimethylfluorene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. And cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder P142.

M/Z theoretical value: 779; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 780.

synthesis example 6: synthesis of Compound P176

In a 1000mL single-neck flask, 15g of M4, 16g of 9- (4-bromophenyl) phenanthrene, 0.5g (1mmol) of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder M4-1.

In a 1000mL single neck flask, 28g of M4-1, 13.6g of 3-bromo-9, 9-dimethylfluorene, 0.9g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction solution, concentrating the organic phase, adding methanol, stirring for 1h, and vacuum filtering to obtain light yellow powderAnd finally P176.

M/Z theoretical value: 753; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 754.

synthesis example 7: synthesis of Compound P205

In a 1000mL single-neck flask, 16g of M5, 16.5g of 9- (3-bromophenyl) phenanthrene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder M5-1.

In a 1000mL single-neck flask, 28.5g of M5-1, 13g of 2-bromo-dibenzofuran, 0.9g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. And cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder P205.

M/Z theoretical value: 759; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 760.

synthesis example 8: synthesis of Compound P18

Into a 1000mL single-necked flask were added 13.5g of M1, 19g of 9- (4-bromonaphthyl) phenanthrene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction solution,concentrating the organic phase, adding methanol, stirring for 1h, and filtering to obtain light yellow powder M1-3.

In a 1000mL single neck flask, 28.5g of M1-3, 13.6g of 3-bromo-9, 9-dimethylfluorene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and filtering to obtain light yellow powder P18.

M/Z theoretical value: 763; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 764.

synthesis example 9: synthesis of Compound P101

In a 1000mL single-neck flask, 15g of M6, 16.6g of 9- (4-bromophenyl) phenanthrene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder M6-1.

In a 1000mL single-neck flask, 27.4g of M6-1, 12.3g of 2-bromo-dibenzofuran, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. And cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder P101.

M/Z theoretical value: 713; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 714.

synthesis example 10: synthesis of Compound P111

In a 1000mL single-neck flask, 16.8g of M7, 16.5g of 9- (4-bromophenyl) -phenanthrene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder M7-1.

In a 1000mL single-neck flask, 29.5g of M7-1, 15.4g of 4-bromo-terphenyl, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. And cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder P111.

M/Z theoretical value: 815; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 816.

synthesis example 11: synthesis of Compound P114

In a 1000mL single-neck flask, 29.5g of M7-1, 14g of 1- (4-bromophenyl) naphthalene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. And cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder P114.

M/Z theoretical value: 789; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 790.

synthesis example 12: synthesis of Compound P124

In a 1000mL single-neck flask, 16.8g of M7, 16.5g of 9- (3-bromophenyl) -phenanthrene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder M7-2.

In a 1000mL single-neck flask, 29.5g of M7-2, 8.7g of bromobenzene, 0.5g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. And cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder P124.

M/Z theoretical value: 663; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 664.

synthesis example 13: synthesis of Compound P179

In a 1000mL single-neck flask, 15.4g of M8, 16g of 9- (3-bromophenyl) phenanthrene, 0.5g (1mmol) of tris (dibenzylideneacetone) dipalladium (i.e., Pd)₂(dba)₃) 0.5g of IPr.HCl, 500mL of toluene, 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 90 ℃ for reaction for 5 hours. And stopping the reaction after the reaction is finished. Cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder M8-1.

In 1000mL of a monomerInto a mouth bottle, 28g of M8-1, 13.6g of 3-bromo-9, 9-dimethylfluorene, 0.9g of tris (dibenzylideneacetone) dipalladium (i.e., Pd) were added₂(dba)₃) 0.5mL of tri-tert-butylphosphine ((t-Bu)₃P), 500mL of toluene and 15g of sodium tert-butoxide (NaOBu-t), vacuumizing and changing nitrogen for 3 times, and heating the reaction to 110 ℃ for 5 hours. And stopping the reaction after the reaction is finished. And cooling to room temperature, separating the reaction liquid, concentrating the organic phase, adding methanol, stirring for 1h, and performing suction filtration to obtain light yellow powder P179.

M/Z theoretical value: 753; ZAB-HS type mass spectrometer (manufactured by Micromass, UK) M/Z measured value: 754.

example 1

The embodiment provides an organic electroluminescent device, which is specifically prepared as follows:

the glass plate coated with the ITO transparent conductive layer (as anode) 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 to less than 1 × 10^-5Pa, performing vacuum evaporation on the anode layer film to obtain HI-3 serving as a hole injection layer, wherein the evaporation rate is 0.1nm/s, and the evaporation film thickness is 10 nm;

evaporating HT-4 on the hole injection layer in vacuum to serve as a hole transport layer of the device, wherein the evaporation rate is 0.1nm/s, and the total film thickness of the evaporation is 80 nm;

and (3) evaporating the compound P2 on the hole transport layer in vacuum to be used as an electron barrier layer material of the device, wherein the evaporation rate is 0.1nm/s, and the total film thickness of the evaporation is 80 nm.

A luminescent layer of the device is evaporated on the electron blocking layer in vacuum, the luminescent layer comprises a main material and a dye material, the evaporation rate of the main material PH-59 is adjusted to be 0.1nm/s by using a multi-source co-evaporation method, the evaporation rate of the dye RPD-8 is set to be 3% of the main material in proportion, and the total evaporation film thickness is 30 nm;

and (3) carrying out vacuum evaporation on an electron transport layer of the device on the light-emitting layer, adjusting the ratio of the material ET-46: ET-57(50/50, w/w), evaporation rate of 0.1nm/s, total film thickness of 30 nm;

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

Examples 2 to 13 and comparative examples 1 to 4 were carried out in the same manner as in example 1 except that the compound P2 as an electron blocking layer material was replaced with the compounds shown in table 1, respectively.

The structure of the electron barrier material of the comparative example is as follows:

wherein R-1, R-2 and R-4 are described in detail in patent application CN110511151A, and R-3 is described in patent application WO2019164327A 1.

And (3) performance testing:

the organic electroluminescent device prepared by the above process was subjected to the following performance measurement: the current efficiencies of the organic electroluminescent devices prepared in the above examples and comparative examples were measured at the same luminance using a digital source meter (Keithley2400) and a luminance meter (ST-86LA model luminance meter, photoelectric instrument factory of beijing university). 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 3000cd/m²Then, the ratio of the brightness to the current density at this time was measured as the current efficiency, and the test results are shown in table 1.

TABLE 1

As can be seen from the data in Table 1, when the compound of the present invention is used as an electron blocking layer material of an organic electroluminescent device, the brightness of the device is improvedUp to 3000cd/m²When the current efficiency is as high as more than 19.6d/A, even more than 20cd/A, the current efficiency can be effectively improved, and the material is an electronic barrier layer material with good performance.

The compound R-1 of comparative example 1 is different from the compound P2 of example 1 in that the compound R-1 has a structure which is one less linking group (L) between phenanthryl and N than P2³) When the compound is used as an electron blocking layer material of an organic electroluminescent device, the current efficiency is 17.6cd/A, which is inferior to P2, due to the linking group (L)³) Compared with R-1, the introduction of the P2 has a better spatial structure and a higher refractive index, and has more reasonable LUMO and HOMO energy levels and better spatial orientation, thereby improving the current efficiency of the device. The compound R-2 of comparative example 2 differs from the compound P10 of example 2 in that there is one less linking group (L) between the phenanthryl and the N atom³) Comparative example 2 had a current efficiency of only 19.2cd/a, inferior to example 2 for the reasons described previously.

The compound R-3 of comparative example 3 is different from the compound P2 of example 1 in that the structure of the compound R-3 is not binaphthyl at the point of attachment to nitrogen, but 1-naphthyl substitution at position 10 of phenanthrene; when the compound is used as an electron blocking layer material of an organic electroluminescent device, the current efficiency is only 16.3cd/A, which is worse than that of P2, because the benzene rings of R-3 which are more than those of P2 change the LUMO and HOMO energy levels of molecules and greatly change the spatial orientation of the molecules, the current efficiency of the device is greatly reduced, and the problem is avoided by the optimization of the structure.

The compound R-4 of comparative example 4 is different from the compound P10 of example 2 in that the compound R-4 has a structure in which the N atom is substituted with 4- (1-naphthyl) benzene and P10 is substituted with 4- (9-phenanthryl) benzene; when the compound is used as an electron barrier layer material of an organic electroluminescent device, the current efficiency is 19.5cd/A, which is inferior to P10, because P10 has better hole transport capability than R-4, thereby improving the current efficiency of the device.

In conclusion, compared with the prior art, the invention uses the compoundsThe compound is matched with naphthalene rings, so that a better spatial structure and a higher refractive index can be obtained, and meanwhile, more reasonable LUMO and HOMO energy levels and better spatial orientation are achieved, so that the luminous efficiency of the device is further improved, compared with the prior art that the compound is improved by 8-19%, and the luminous efficiency is reduced by changing any one group.

By comparing example 8 with example 2, it can be seen that when L is³In the case of a phenylene group (example 2), when the formed compound is used in an organic electroluminescent device, the light emitting efficiency of the device can be further improved, because the phenylene group can regulate and control the HOMO and LUMO energy levels of molecules, and because the structure size is appropriate, the crowding degree of molecules can be effectively relieved, and simultaneously, the transport property of the material can be accurately regulated and controlled to match with that of the corresponding device.

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.