CN109309163B

CN109309163B - Organic electroluminescent device

Info

Publication number: CN109309163B
Application number: CN201710618597.XA
Authority: CN
Inventors: 乔娟; 王瑞
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2017-07-26
Filing date: 2017-07-26
Publication date: 2019-12-17
Anticipated expiration: 2037-07-26
Also published as: CN109309163A

Abstract

The invention provides an organic electroluminescent device, which comprises a cathode, an anode and organic thin film layers, wherein at least one layer of the organic thin film layers contains a compound shown in the following formula (1) singly or as a mixture component:In the formula (1), X is selected from nitrogen atom or R¹Bonded carbon atoms, C₁To C₅Are each independently selected from the group consisting of²Bonded carbon atoms, R¹And R²Each independently selected from a hydrogen atom, a cyano group, a straight-chain alkyl group or a fluoroalkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms. The present invention also provides a novel compound selected from the above-mentioned general formula (1). The organic electroluminescent device has very good electrical property, and the compound with the general formula can be used as a luminescent material, so that the stability is very good.

Description

Organic electroluminescent device

Technical Field

The present invention relates to a novel organic electroluminescent device that can be used in the field of luminescence, and more particularly, to an organic electroluminescent device using a novel stable luminescent material.

Background

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

With the continuous advance of the OLED technology in the two fields of illumination and display, people pay more attention to the research of efficient organic materials influencing the performance of OLED devices, and an OLED device with good efficiency and long service life is generally the result of the optimized matching of the device structure and various organic materials. In the most common OLED device structures, the following classes of organic materials are typically included: hole injection materials, hole transport materials, electron transport materials, and light emitting materials (dyes or doped guest materials) and corresponding host materials of each color.

One class of OLED materials that is currently hot is called Thermally Activated Delayed Fluorescence (TADF) materials. The energy difference between the singlet energy level and the triplet energy level of such materials is small. Therefore, a large amount of triplet excitons generated by the electro-excitation can be changed into singlet excitons capable of generating radiative transition through the reverse intersystem crossing, and the high efficiency of the corresponding device is realized. Such materials are generally electron donor-linker-electron acceptor structures.

The lifetime of an OLED device is affected by many factors, and the stability of the light-emitting material is an essential factor determining its lifetime. The stability of the luminescent material mainly includes the stability of chemical bonds in the material molecules and the oxidation resistance of the material. Studies have reported that the excitation energy of many light-emitting materials is equivalent to the energy of the weakest bond in the molecule, which is generally the bond between the electron donor and the linker, and thus the weakest bond is easily broken in the excited state, thereby causing the materials to be degraded and the device lifetime to be reduced. On the other hand, most of the electron donors of the luminescent materials have the problems of low oxidation potential and much larger hole-transporting capability than electron-transporting capability, which causes the problems that the electron donors are easy to generate charge injection imbalance or oxidation and the like during the working process, and the efficiency and the service life of the device are reduced.

Disclosure of Invention

In order to solve the above problems of the prior art, the present invention provides a highly efficient and long-life organic electroluminescent device which emits light efficiently by using a light-emitting material with excellent stability and a TADF mechanism, and also provides a novel compound having a TADF light-emitting mechanism with excellent stability.

The present invention provides an organic electroluminescent device comprising a cathode, an anode, and an organic thin film layer comprising at least one layer comprising a light-emitting layer and disposed between the cathode and the anode, wherein at least one of the organic thin film layers comprises a compound represented by the following general formula (1) alone or as a component of a mixture:

In the general formula (1), X is selected from nitrogen atom or R¹Bound carbon atoms, i.e. CR¹，C₁To C₅Are each independently selected from the group consisting of²bound carbon atoms, i.e. CR²Said R is¹And R²Each independently selected from a hydrogen atom, a cyano group, a straight-chain alkyl group or a fluoroalkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms.

when R is¹And R²When the substituents are independently selected from substituted aromatic hydrocarbon groups or heteroaromatic hydrocarbon groups, the substituents on the substituents are independently preferably trifluoromethyl, cyano, or selected from alkyl or cycloalkyl, alkenyl, alkoxy or thioalkoxy groups having 1 to 10 carbon atoms, or independently selected from monocyclic or fused ring aryl groups containing a heteroatom selected from N, O, S, Si and having 4 to 15 ring carbon atoms.

When R is¹And R²When each is independently selected from a substituted aromatic hydrocarbon group or a heteroaromatic hydrocarbon group, the substituent on the group is preferably independently selected from a cyano group, a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, an alkoxy group, a phenyl group, a naphthyl group, a pyridyl group, and a pyrrolyl group.

C₁To C₅At least 1 is a carbon atom bonded to a cyano group. More preferably, C₁To C₅1 to 3 of which are carbon atoms bonded to a cyano group.

At the same time, C₁To C₅of which 1 or 2 are selected from carbon atoms bonded to the group Q via a dotted line, or from carbon atoms bonded to the group Q via a group L.

The L group is a divalent group selected from the group consisting of an alkylene group having 1 to 20 carbon atoms, a carbonyl group (-CO-), a sulfoxide group (-SO-), and a sulfone group (-SO-)₂-) or phenylene.

The general structural formula of the group Q is shown as a general formula (2):

In the general formula (2), X₁To X₄Each independently selected from a nitrogen atom, a carbon atom bonded to a hydrogen atom, and R³Bound carbon atoms, i.e. CR³And X₁To X₄At least one of them is selected from nitrogen atoms. Further preferably X₁To X₄In (1) is only X₁Or X₃Selected from nitrogen atoms.

The R is³selected from the group consisting of a straight chain alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a trifluoromethyl group, a bromine atom.

y is selected from a hydrogen atom, a straight chain alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms.

R is as defined above¹、R²And R³preferred examples of the alkyl group each independently selected from a straight-chain alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms include: methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, chloromethyl, 1-chloroethyl, 2-chloroethyl, 1, 2-dichloroethyl, 2, 3-dichlorotert-butyl, bromomethyl, 1, 2-dibromoethyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl.

R is as defined above¹and R²Preferred examples each independently selected from substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms include: phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 4-phenanthryl, 9-phenanthryl, 1-tetracenyl, 2-tetracenyl, 9-tetracenyl, 1-pyrenyl, 2-pyrenyl, 4-pyrenyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, p-terphenyl-4-yl, p-terphenyl-3-yl, m-terphenyl-4-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p-tert-butylphenyl, p- (2-phenylpropyl) p-tolyl) Phenyl, 3-methyl-2-naphthyl, 4-methyl-1-anthryl, 4' -methyl biphenyl.

R is as defined above¹And R²Preferred examples each independently selected from the group consisting of substituted or unsubstituted heteroaromatic hydrocarbon groups having 5 to 30 carbon atoms include: 1-pyridine, 2-pyridyl, 3-pyridyl, 2-quinolyl, 3-quinolyl, 6-quinolyl, 3-isoquinolyl, 2-quinoxalyl, 5-quinoxalyl, 1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 9-carbazolyl, 1-phenanthridinyl, 9-phenanthridinyl.

Further, the present invention provides an organic electroluminescent device wherein the compound constituted by the combination of the general formula (1) and the general formula (2) may preferably have the following general formula (1-1), (1-2) or (1-3):

In the above general formulae (1-1), (1-2) and (1-3), the group Q is synonymous with Q in the above general formula (2). In the formula (1-1), the group L is the same as L in the above formula (1). In the formulae (1-3), X is defined synonymously with X in the general formula (1).

A₁To A₄Each independently selected from a cyano group, a hydrogen atom, a straight chain alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms, and A₁To A₄Up to two of which are simultaneously selected from cyano groups.

A above₁To A₄Preferred examples of the alkyl group each independently selected from a straight-chain alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms include: methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, chloromethyl, 1-chloroethyl, 2-chloroethyl, 1, 2-dichloroethyl, 2, 3-dichlorotert-butyl, bromomethyl, 1, 2-dibromoethyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl.

a above₁To A₄Preferred examples each independently selected from substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms include: phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 4-phenanthryl, 9-phenanthryl, 1-tetracenyl, 2-tetracenyl, 9-tetracenyl, 1-pyrenyl, 2-pyrenyl, 4-pyrenyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, p-terphenyl-4-yl, p-terphenyl-3-yl, m-terphenyl-4-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p-tert-butylphenyl, p- (2-phenylpropyl) phenyl, 3-methyl-2-naphthyl, 4-methyl-1-naphthyl, 4-methyl-1-anthryl and 4' -methyl biphenyl.

a above₁To A₄Preferred examples each independently selected from the group consisting of substituted or unsubstituted heteroaromatic hydrocarbon groups having 5 to 30 carbon atoms include: 1-pyridine, 2-pyridyl, 3-pyridyl, 2-quinolyl, 3-quinolyl, 6-quinolyl, 3-isoquinolyl, 2-quinoxalyl, 5-quinoxalyl, 1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 9-carbazolyl, 1-phenanthridinyl, 9-phenanthridinyl.

In particular, when defining R as defined above¹、R²And A₁To A₄Each independently selected from aromatic hydrocarbon groups means an aromatic ring system having a certain number of carbon atoms in the ring skeleton, and includes monocyclic structure substituent groups such as phenyl, etc., aromatic ring substituent groups having a covalently bonded structure such as biphenyl, terphenyl, etc., condensed ring structure substituent groups such as naphthyl, anthryl, etc., condensed ring structure substituent groups linked to monocyclic structure aryl groups such as biphenylnaphthyl, naphthylbiphenyl, biphenylanthryl, etc., and condensed aromatic ring substituent groups having a covalently bonded structure such as binaphthyl, etc.

In particular, when defining the above R¹、R²And A₁To A₄Each independently selected from heteroaromatic hydrocarbon groups means a monocyclic or fused ring aryl group containing one or more heteroatoms selected from B, N, O, S, P (═ O), Si and P and having a ring carbon atom.

Further, the present invention provides an organic electroluminescent device wherein the structure of the compound disclosed in the general formula (2) and the general formulae (1-1), (1-2) and (1-3) may preferably be the following general formulae (1-11), (1-21) or (1-31):

In the above formulae (1-11), (1-21) and (1-31), A₁To A₄are the same as defined in the general formulae (1-1), (1-2) and (1-3). M₁And M₂independently selected from carbon atoms bonded to hydrogen atoms, and R⁴Bound carbon atoms, i.e. CR⁴Said R is⁴selected from a linear alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a trifluoromethyl group or a bromine atom. In the formulae (1 to 31), X is defined synonymously with X in the general formula (1).

The invention also provides a compound shown as the following general formula (1):

When R is¹And R²When each is independently selected from substituted aromatic hydrocarbon group or heteroaromatic hydrocarbon group, the substituents thereon are independently preferably selected from trifluoromethyl group, cyano group, or from group having 1 to 10 substituentsAn alkyl or cycloalkyl, alkenyl, alkoxy or thioalkoxy group of carbon atoms, or independently selected from monocyclic or fused ring aryl groups containing a heteroatom selected from N, O, S, Si and having 4 to 15 ring carbon atoms.

r is as defined above¹And R²Preferred examples each independently selected from substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms include: phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 4-phenanthryl, 9-phenanthryl, 1-tetracenyl, 2-tetracenyl, 9-tetracenyl, 1-pyrenyl, 2-pyrenyl, 4-pyrenyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, p-terphenyl-4-yl, p-terphenyl-3-yl, m-terphenyl-4-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p-tert-butylphenyl, p- (2-phenylpropyl) phenyl, 3-methyl-2-naphthyl, 4-methyl-1-naphthyl, 4-methyl-1-anthryl and 4' -methyl biphenyl.

Further, the general structural formula of the compound constituted by combining the general formula (1) and the general formula (2) may preferably be the following general formula (1-1), (1-2) or (1-3):

a above₁To A₄Preferred examples each independently selected from the group consisting of substituted or unsubstituted heteroaromatic hydrocarbon groups having 5 to 30 carbon atoms include: 1-pyridine, 2-pyridyl, 3-pyridyl, 2-quinolyl, 3-quinolyl, 6-quinolyl, 3-isoquinolyl, 2-quinoxalyl, 5-quinoxalyl, 1-carbazolyl, 2-quinolyl,3-carbazolyl, 9-carbazolyl, 1-phenanthridinyl and 9-phenanthridinyl.

Further, the structure of the compound disclosed in the general formula (2) and the general formulae (1-1), (1-2) and (1-3) may preferably be the following general formulae (1-11), (1-21) or (1-31):

further, the present invention discloses a specific preferred structure as follows:

The novel organic luminescent material and the organic electroluminescent device adopting the compound have the following advantages:

First, the novel organic electroluminescent device of the present invention is designed by preferably using a novel compound having carboline as a donor as a light emitting material, and the device has very good electrical properties, low luminance, high current efficiency, and long lifetime.

In the prior art, the hole transport capacity of a material taking carbazole or acridine and the like as donors is often far greater than that of electrons, so that unbalanced transport and injection of carriers are caused, and excessively strong hole transport capacity can cause generation of carrier traps in an optical layer and positive charge accumulation, which can cause reduction of efficiency and service life of corresponding OLED devices.

The preferable novel compound uses carboline as a donor, and the electron donating capability of the carboline is weaker than that of carbazole, so that the hole transport capability of the corresponding material is reduced to a certain extent, the electron transport capability of the material is greatly improved, and the material with matched electron and hole transport capabilities is easier to obtain.

Therefore, when the compound with the general formula is adopted in the novel organic electroluminescent device, electrons and holes injected and transmitted in the device are matched, the lighting voltage of the device is lower, the efficiency of the device is higher, and the service life of the device is longer.

In addition, the luminescent layer in the organic electroluminescent device of the invention can only adopt a novel compound which is preferably selected from the compounds with the general formula and takes carboline as a donor, namely the material does not need to be doped with a luminescent main body material, thereby realizing a non-doped device with simpler device structure and easier preparation method.

Secondly, the novel compounds of the general formula of the present invention have good molecular stability. The invention focuses on the research result of the present academic world on the stability of the material when designing the structure of the material. It is considered that, in order to stabilize a light emitting material, the bond energy of the weakest bond in the material molecule is required to be higher than the excitation energy of the material molecule, otherwise, the weakest bond is easily broken in the excited state, which leads to instability of the material and short device lifetime. Most of the current TADF materials have a D (donor) -pi-A (acceptor) structure, the weakest bond is a D-pi bond, quantum chemistry calculations show that the dissociation energy (BDE) of the D-pi bond of the materials is generally lower than 3.5eV, and thus, the traditional materials taking pure carbazole (or carbazole modified by electron-donating substituents) and acridine as donors have the condition that C-N bond is broken to cause the degradation of material molecules in the working process. The preferable molecular structure in the novel compound designed by the invention is that carboline is taken as a donor, and the BDE of the C-N bond between the carboline (D) and benzene can exceed 3.7eV and is far higher than the energy of blue light about 3 eV; this ensures that the molecular framework is stable in the excited state.

In addition, another reason why the material is unstable is that it may be photo-or electro-oxidized, i.e. injected with more than 1 hole, during its operation, which may result in that the material molecule cannot emit light and even further undergoes chemical changes, thereby reducing the lifetime of the device. In the design of the invention, the nitrogen at the 1-position of the carboline is sp²Hybridization actually plays a role in electron absorption, and is helpful for reducing the pi electron density on the Highest Occupied Molecular Orbital (HOMO) level, so that the HOMO level of the material can be effectively reduced, and the oxidation potential of the material can be improved.

In combination of the above two points, the stability of the novel material using carboline as donor, which is preferable in the compound of the general formula provided by the present invention, is greatly improved compared with the stability of the material using pure carbazole (or carbazole substituted by electron-donating groups such as alkyl, methoxy and carbazolyl) or acridine as donor. Furthermore, the lifetime of the organic electroluminescent device using the novel compound of the present invention, particularly the preferred carboline-donor compound as the light-emitting material, is greatly improved, and reference is made to the following contents of examples 1 to 4 and the accompanying drawing 3 of the corresponding specification.

Thirdly, the novel organic electroluminescent device of the present invention may preferably be a blue device, and the novel compound of the present invention may be an excellent blue electroluminescent material. In the molecular design process of the material, the electron-withdrawing group is replaced, so that the energy of a front line orbit of the material is reduced. Such molecular design enables the material to more easily obtain a bluer luminescence and the material to have a higher color purity. On the other hand, as the energy of the front-line orbit of the material is reduced, the energy gap between the occupied orbit and the vacuum level is larger, so that the material is less prone to be oxidized, the novel compound provided by the invention is ensured to have very good stability, and the corresponding novel organic electroluminescent device provided by the invention has a longer service life.

Drawings

These and/or other aspects and advantages of the present invention will become more apparent and more readily appreciated from the following detailed description of the embodiments of the invention, taken in conjunction with the accompanying drawings of which:

Fig. 1 is a schematic configuration diagram of an example of an organic electroluminescent device according to an embodiment of the present invention.

FIG. 2 is a front line orbital plot of preferred compounds of the invention, C1 and C3.

Fig. 3 is a graph of life test performance data for devices prepared according to examples 1-4 of the present invention.

Detailed Description

In order that those skilled in the art will better understand the present invention, the following detailed description of the invention is provided in conjunction with the accompanying drawings and the detailed description of the invention.

Mode for preparing an organic electroluminescent device embodiment of the present invention:

Referring to fig. 1, the present invention further provides a selective organic electroluminescent device 1, which includes an anode 3, an organic thin film layer 10 and a cathode 4, wherein the organic thin film layer 10 further includes a hole injection layer 6, a hole transport layer 7, a light emitting layer 5, an electron transport layer 8 and an electron injection layer 9, which are sequentially stacked.

The anode 3 is used for injecting holes into the hairIn the optical layer, the anode should be made of a conductive material, and specifically, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), and tin dioxide (SnO) can be mentioned₂) And one or more of zinc oxide (ZnO), silver, aluminum, gold, platinum and palladium.

When light emission from the light-emitting layer is extracted from the anode side, the transmittance of light in the visible region of the anode is preferably set to be greater than 10%. The sheet resistance of the anode is preferably several hundred ohms per square or less. The thickness of the anode is selected depending on the material, and is usually in the range of 10nm to 1 μm, preferably 10nm to 200 nm.

As the cathode, a material having a small work function is preferable for the purpose of injecting electrons into the light-emitting layer. Specifically, indium, aluminum, magnesium, a magnesium-indium alloy, a magnesium-aluminum alloy, an aluminum-lithium alloy, an aluminum-scandium-lithium alloy, a magnesium-silver alloy, and the like can be used.

The cathode may be formed with a thin film on the electron transport layer or the electron injection layer by a method such as vapor deposition, as in the case of the anode. Further, light emission from the light-emitting layer may be extracted from the cathode side. When light emission from the light-emitting layer is extracted from the cathode side, the transmittance of light in the visible region of the cathode is preferably set to be greater than 10%. The sheet resistance of the cathode is preferably several hundred ohms per square or less. The thickness of the cathode is selected depending on the material, and is usually 10nm to 1 μm, preferably 50nm to 200 nm.

The hole injection layer and/or the hole transport layer is a layer which assists injection of holes into the light-emitting layer and transport them to the light-emitting region, and a compound having a large hole mobility and a small ionization energy is used. As a material for forming the hole injecting and/or transporting layer, a material having a higher hole mobility at a lower electric field intensity and capable of transporting holes to the light-emitting layer is preferable, and for example, one or more of phthalocyanine compounds and aromatic amine compounds are suitably used, specifically, 4, 4 ' -bis [ N- (1-naphthyl) -N-phenylamino ] biphenyl (NPB), N ' -bis (3-methylphenyl) -N, N ' -diphenylbiphenyl (TPD), 1,3, 5-tris (3-methyldiphenylamino) benzene (m-MTDATA), Polyvinylcarbazole (PVK), or the like.

The electron injection and/or electron transport layer assists injection of electrons into the light emitting layer and transports them to a layer of the light emitting region, using a compound having high electron mobility. As the compound used in the electron injecting and/or transporting layer, a material having a high electron mobility is preferably used, such as an aromatic heterocyclic compound having 1 or more hetero atoms in the molecule, particularly preferably a nitrogen-containing ring derivative, preferably a heterocyclic compound having a nitrogen-containing 6-or 5-membered ring skeleton, specifically, one or more of an oxazole compound, a quinoline compound, an oxinoid compound, a diazaanthracene derivative and a phenanthroline derivative.

The compound with the general formula can be applied to organic electroluminescent devices, namely OLED devices as a luminescent material.

The light-emitting layer of the present invention is not limited to one layer, and a plurality of light-emitting layers may be stacked. When the organic electroluminescent element of the present invention has a plurality of light-emitting layers, at least one of the light-emitting layers may contain the compound of the above general formula disclosed in the present invention, and the other light-emitting layer may be a fluorescent light-emitting layer or a phosphorescent light-emitting layer. In the case where the organic electroluminescent device of the present invention has a plurality of light-emitting layers, these light-emitting layers may also be disposed adjacent to each other.

In the organic compound layer other than the light-emitting layer of the organic electroluminescent device of the present invention, any compound can be selected from known compounds used in conventional OLED devices, in addition to the above-mentioned exemplified compounds.

The method of forming each layer of the organic electroluminescent element of the present invention is not particularly limited except for the above-mentioned methods, and a dry film forming method such as vacuum deposition, sputtering, plasma, ion plating, or the like can be used; and known methods such as wet film formation methods including spin coating, dipping, flow coating, and ink jet.

The film thickness of each organic layer of the organic electroluminescent element of the present invention is not particularly limited except for the film thickness mentioned above, but generally, when the film thickness is too thin, defects such as pinholes tend to occur, whereas when the film thickness is too thick, a high applied voltage is required and the efficiency is deteriorated, so that a range of from 10nm to 1 μm is generally preferable.

In the following examples 1 to 3, three organic electroluminescent devices of the present invention, OLED-1, OLED-2 and OLED-3, respectively, were prepared.

Example 1: preparation of OLED-1

The glass plate coated with the ITO transparent conductive layer is subjected to ultrasonic treatment in a cleaning agent, washed in deionized water, ultrasonically degreased in a mixed solvent of acetone and ethanol, baked in a clean environment to completely remove moisture, cleaned by ultraviolet light and ozone, and bombarded on the surface of the ITO transparent conductive layer by low-energy cation beams, so that the glass substrate 2 with the anode 3 is obtained, wherein the ITO transparent conductive layer is the anode 3.

Placing the glass plate 2 with the anode 3 in a vacuum chamber, and vacuumizing to 1 × 10^-5～9×10^-3pa, HAT-CN as a hole injection layer 6 was vacuum-deposited on the anode at a deposition rate of 0.1nm/s and a deposition thickness of 5 nm. Then NPB with a thickness of 20nm and TCTA with a thickness of 20nm were sequentially evaporated at a rate of 0.1nm/s as the hole transport layer 7.

a layer of DPEPO was vacuum evaporated onto the surface of the hole transport layer 7 facing away from the glass plate: 8 wt% of C1 was used as the organic light-emitting layer 5 of the device, the evaporation rate was 0.1nm/s, and the total film thickness was 20 nm.

DPEPO with a thickness of 10nm and TPBi with a thickness of 30nm are sequentially evaporated on the organic light-emitting layer 5 at a rate of 0.1nm/s to form a hole transport layer 8.

And evaporating a layer of LiF as an electron injection layer 9 on the surface of the electron transport layer 8 far away from the organic light-emitting layer 5, wherein the evaporation rate is 0.1nm/s, and the evaporation film thickness is 0.8 nm.

And finally, evaporating a layer of Al on the surface of the electron injection layer 9 to be used as a cathode, wherein the evaporation rate is 0.3nm/s, and the thickness is 100 nm.

The structures of the above various organic materials are shown in the following figures:

Example 2: preparation of OLED-2

This embodiment is substantially the same as embodiment 1, except that: the luminescent material is DPEPO: 8% wtC 3.

example 3: preparation of OLED-3

This embodiment is substantially the same as embodiment 1, except that: the luminescent material is DPEPO: 8% wtC 9.

Example 4 below as a comparative example to inventive examples 1 to 3, a parallel comparative device OLED-4 was prepared using exactly the same device structure design:

Example 4: preparation of OLED-4

This embodiment is substantially the same as embodiment 1, except that: the luminescent material is DPEPO:

8% wtDCzTrz, which is a commonly used blue light emitting material in the prior art, and has a structural formula shown in the following figure:

The properties of the OLED-1, OLED-2, OLED-3 and OLED-4 are detailed in Table 1.

TABLE 1

In Table 1, "ITO/HAT-CN (5nm)/NPB (20nm)/TCTA (20 nm)/DPEPO: 8 wt% C1(20nm)/DPEPO (10nm)/TPBi (30nm)/LiF (0.8nm)/Al (100nm) "means in this order: the anode is ITO; HAT-CN formed a film with a thickness of 5 nm; NPB forms a film with a thickness of 20 nm; TCTA forms a film with a thickness of 20 nm; DPEPO and 8 wt% C1 formed into a film with a thickness of 20 nm; DPEPO formed a film with a thickness of 10 nm; TPBi forms a film with a thickness of 30 nm; LiF forms a film with a thickness of 0.8 nm; al forms a film (cathode) with a thickness of 100 nm. By analogy, the meanings of other parts in the structure composition of table 1 can be known, and the description is omitted here. T is₅₀Is a device at 500cd/m²Initial brightness ofMeasured under, i.e. T₅₀The luminous intensity of the device is from 500cd/m²Attenuation to 250cd/m²the elapsed time.

The organic electroluminescent device prepared in the embodiment of the invention adopts the optional compounds C1, C3 and C9, and specific experimental data in Table 1 show that:

First, compared with a reference device OLED-4, the luminescent colors of OLED-1, OLED-2 and OLED-3 adopting the compound are blue light with higher color purity, and are particularly represented by smaller y value of color coordinate.

Secondly, OLED-1, OLED-2 and OLED-3 all have relatively high luminous efficiency, and especially the luminous efficiency of OLED-2 is improved by nearly 3% compared with that of comparative example OLED-4.

Thirdly, compared with a reference device OLED-4, the OLED-1, the OLED-2 and the OLED-3 adopting the compound have the service life which is greatly superior to that of the comparative example OLED-4, and particularly the service life of the OLED-3 reaches more than 6 times of that of the comparative example OLED-4.

It can be seen that the organic electroluminescent device of the present invention indeed has very good electrical properties, in particular excellent performance in terms of lifetime, and thus it is also demonstrated that the present invention proposes that such novel compounds have very good stability on the basis of very good luminescent properties.

Preparation of novel compounds synthesis embodiments of the invention:

Compounds of synthetic methods not mentioned in the present invention are all starting products obtained commercially. Various chemicals used in the examples, such as 9H-alpha-carboline, 2, 4-difluorophenylboronic acid, and 2, 5-dichloroterephthalonitrile, and other chemical raw materials or intermediates, are commercially available in domestic chemical products.

The analytical detection of intermediates and compounds in the present invention uses an AXIMA Performance mass spectrometer.

synthesis examples:

Synthesis example 1: synthesis of Compound C1

1.1 Synthesis of intermediate C1-1

C1-1 Structure As shown in the above figure, 4-chloro-1, 3-benzenedinitrile (1.00g, 6.2mmol), 2, 4-difluorophenylboronic acid (1.26g, 8.0mmol), potassium carbonate (3.50g, 25.4mmol) and tetrakis (triphenylphosphine) palladium (0.35g, 0.3mmol) were added in this order to a 100mL flask, followed by 10mL of water and 30mL of dioxane under oxygen. Oxygen in the system is removed by vacuumizing and introducing nitrogen, and then the system is heated to 95 ℃ and refluxed for 18 hours. After cooling to room temperature, the aqueous phase was separated and the organic phase was spin-dried, the product was purified by silica gel column chromatography using 1:1 dichloromethane-petroleum ether as eluent, and 1.08g of a white solid was obtained in 73% yield after spin-drying the solvent.

1.2 Synthesis of C1

A100 mL flask was charged with 9H- α -carboline (1.00g, 6.0mmol) and 50mL dry tetrahydrofuran, added NaH (0.18g, 7.5mmol), stirred under nitrogen for 20min, then added C1-1(1g, 4.2mmol), heated to 75 deg.C under nitrogen reflux for 24H. After cooling to room temperature, suction filtration was carried out, and the filter cake was washed successively with water, methanol and dichloromethane to give 1.01g of a white solid in a yield of 45%. Mass spectrometry analysis: MALDI-TOF-MS m/z: 536.2. Elemental analysis: theoretical values of C80.6%, H3.8% and N15.6%; the experimental values are C80.9%, H3.8% and N15.2%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.56(4H),8.43(2H),8.16(1H),8.10-8.09(3H),7.94(2H),7.56(1H),7.40(1H),7.35-7.20(6H)

Synthesis example 2: synthesis of Compound C3

2.1 Synthesis of intermediate C3-1

The structure of C3-1 is shown in the above figure. In a 100mL flask were added 2, 5-dichloroterephthalonitrile (1.00g, 5.1mmol), 2, 4-difluorophenylboronic acid (2.05g, 13.0mmol), potassium carbonate (3.50g, 25.4mmol), and tetrakis (triphenylphosphine) palladium (0.35g, 0.3mmol) in that order, followed by 10mL of water and 30mL of dioxane under oxygen. Oxygen in the system is removed by vacuumizing and introducing nitrogen, and then the system is heated to 95 ℃ and refluxed for 18 hours. After cooling to room temperature, suction filtration was carried out and the filter cake was washed successively with water, methanol and dichloromethane to give 1.2g of a white solid in 65% yield.

2.2 Synthesis of C3

A100 mL flask is added with 9H-alpha-carboline (2.35g, 14mmol) and 50mL dry tetrahydrofuran, then NaH (0.41g, 17mmol) is added, stirring is carried out for 20min under the protection of nitrogen, finally C31(1g, 2.84mmol) is added, nitrogen is introduced for protection, and heating is carried out to 75 ℃ for reflux for 24H. After cooling to room temperature, suction filtration was carried out and the filter cake was washed successively with water, methanol and dichloromethane to give 0.5g of a white solid in 19% yield. Mass spectrometry analysis: MALDI-TOF-MS m/z: 944.7. Elemental analysis: theoretical values of C81.3%, H3.8%, N14.8%; the experimental values are C81.6%, H3.7% and N14.5%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.55(8H),8.43(4H),8.09(4H),7.97(2H),7.94(4H),7.40(2H),7.35-7.20(12H)。

example 3: synthesis of Compound C2

This example is substantially the same as synthetic example 1 except that: in this case, the 9H- α -carboline of the second step is changed to an equivalent amount of 9H-3, 6-dimethyl- α -carboline. Mass spectrometry analysis: MALDI-TOF-MS m/z: 592.2. Elemental analysis: theoretical values of C81.0%, H4.8%, N14.2%; the experimental values are C81.2%, H4.7% and N14.0%.¹H-NMR(400MHz,CDCl3,δ[ppm]):8.73(2H),8.42(2H),8.16(1H),8.12-8.11(3H),7.85-7.70(4H),7.56(1H),7.42(1H),6.88(2H),2.35-2.32(12H)。

Example 4: synthesis of Compound C4

This example is essentially the same as synthetic example 2, except that: in this case, the 9H- α -carboline of the second step is changed to an equivalent amount of 9H-3, 6-dimethyl- α -carboline. Mass spectrometry analysis: MALDI-TOF-MS m/z: 1056.3. Elemental analysis: theoretical values of C81.8%, H5.0%, N13.3%; the experimental values are C81.6%, H4.9% and N13.5%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.73(4H),8.42(4H),8.09(4H),7.96(2H),7.85-7.70(8H),7.40(2H),6.88(4H)，2.35-2.32(24H)。

Example 5: synthesis of Compound C5

This example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloroterephthalonitrile of the first step is exchanged for an equivalent amount of 3, 6-dichloro-1, 2-benzenedinitrile. Mass spectrometry analysis: MALDI-TOF-MS m/z: 944.2. Elemental analysis: theoretical values of C81.8%, H5.0%, N13.3%; the experimental values are C81.5%, H3.8% and N14.5%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.55(8H),8.42(4H),8.31(2H),8.09(4H),7.98(4H),7.40(2H),7.35-7.20(12H)。

example 6: synthesis of Compound C6

This example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloro-terephthalonitrile in the first step is replaced by an equal amount of 3, 6-dichloro-1, 2-benzenedinitrile; the 9H-alpha-carboline of the second step needs to be changed into 9H-3, 6-dimethyl-alpha-carboline with the same quantity. Mass spectrometry analysis: MALDI-TOF-MS m/z: 1056.4. Elemental analysis: theoretical values of C81.8%, H5.0%, N13.3%; the experimental values are C81.7%, H4.9% and N13.3%.¹H-NMR(400MHz,CDCl3,δ[ppm]):8.72(4H),8.42(4H),8.09(4H),8.31(2H),7.85-7.70(8H),7.40(2H),6.88(4H)，2.35-2.31(24H)。

Example 7: synthesis of Compound C7

this example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloro-terephthalonitrile of the first step is exchanged for an equal amount of 2, 5-dichloro-1, 3-benzenedinitrile. Mass spectrometry analysis: MALDI-TOF-MS m/z: 944.3. Elemental analysis: theoretical values of C81.3%, H3.8%, N14.8%; the experimental values are C81.2%, H3.8% and N14.7%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.53(8H),8.41(4H),8.10-8.06(6H),7.98(4H),7.39(2H),7.35-7.20(12H)。

Example 8: synthesis of Compound C8

This example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloro-terephthalonitrile in the first step is replaced by an equal amount of 2, 5-dichloro-1, 3-benzenedinitrile; the 9H-alpha-carboline of the second step needs to be changed into 9H-3, 6-dimethyl-alpha-carboline with the same quantity. Mass spectrometry analysis: MALDI-TOF-MS m/z 1056.4. Elemental analysis: theoretical values of C81.8%, H5.0%, N13.3%; the experimental values are C81.7%, H4.9% and N13.3%.¹H-NMR(400MHz,CDCl3,δ[ppm]):8.73(4H),8.43(4H),8.11-8.06(4H),7.85-7.70(8H),7.40(2H),6.88(4H)，2.35-2.32(24H)。

Example 9: synthesis of Compound C9

This example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloroterephthalonitrile in the first step is replaced by an equal amount of picolonitrile. Mass spectrometry analysis: MALDI-TOF-MS m/z: 944.1. Elemental analysis: theoretical values of C81.3%, H3.8%, N14.8%; the experimental values are C81.4%, H3.8% and N14.5%.¹H-NMR(400MHz,CDCl3,δ[ppm]):8.61(4H),8.53(8H),8.43(4H),7.94(4H),7.51-7.50(6H),7.45(2H),7.42(1H),7.35-7.20(12H)。

Example 10: synthesis of Compound C10

This example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloroterephthalonitrile in the first step needs to be changed into the same amount of the picolyl nitrile; the 9H-alpha-carboline of the second step needs to be changed into 9H-3, 6-dimethyl-alpha-carboline with the same quantity. Mass spectrometry analysis: MALDI-TOF-MS m/z: 1056.5. Elemental analysis: theoretical values of C81.8%, H5.0%, N13.3%; the experimental values are C81.3%, H5.0% and N13.5%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.73(4H),8.60(4H),8.41(4H),7.85-7.70(8H),7.51-7.50(4H),7.45(2H),7.42(1H),6.88(4H)，2.35-2.32(24H)。。

Example 11: synthesis of Compound C11

This example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloro-terephthalonitrile of the first step is exchanged for an equivalent amount of 3, 5-dichloro-1, 2-benzenedinitrile. Mass spectrometry analysis: MALDI-TOF-MS m/z: 944.4. Elemental analysis: theoretical values of C81.3%, H3.8%, N14.8%; the experimental values are C81.2%, H3.9% and N14.8%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.54-8.53(8H),8.43(4H),8.16(1H),8.10-8.08(4H),7.94(4H),7.87(1H),7.40(2H),7.35-7.20(12H)。

example 12: synthesis of Compound C12

This embodiment and combinationThe same as example 2, except that: in this case, the 2, 5-dichloro-terephthalonitrile of the first step is exchanged for an equivalent amount of 3, 5-dichloro-1, 2-benzenedinitrile. The 9H-alpha-carboline of the second step needs to be changed into 9H-3, 6-dimethyl-alpha-carboline with the same quantity. Mass spectrometry analysis: MALDI-TOF-MS m/z: 1056.2. Elemental analysis: theoretical values of C81.8%, H5.0%, N13.3%; the experimental values are C81.7%, H5.0%, N13.1%.¹H-NMR(400MHz,CDCl3,δ[ppm]):8.73(4H),8.42(4H),8.16(1H),8.10-8.09(4H),7.85-7.70(8H),7.86(1H),7.41(2H),6.89(4H)，2.35-2.32(24H)。

Example 13: synthesis of Compound C13

This example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloroterephthalonitrile of the first step is exchanged for an equivalent amount of 4, 6-dichloro-1, 3-benzenedinitrile. Mass spectrometry analysis: MALDI-TOF-MS m/z: 944.5. Elemental analysis: theoretical values of C81.3%, H3.8%, N14.8%; the experimental values are C81.4%, H3.8% and N14.5%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.55-8.53(8H),8.43(4H),8.10(4H),8.05(1H),7.94(4H),7.63(1H),7.40(2H),7.35-7.20(12H)。

Example 14: synthesis of Compound C14

This example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloro-terephthalonitrile of the first step is exchanged for an equivalent amount of 2, 4-dichloro-1, 3-benzenedinitrile. The 9H-alpha-carboline of the second step needs to be changed into 9H-3, 6-dimethyl-alpha-carboline with the same quantity. Mass spectrometry analysis: MALDI-TOF-MS m/z: 1056.3. Elemental analysis: theoretical values of C81.8%, H5.0%, N13.3%; the experimental values are C81.8%, H4.9% and N13.1%.¹H-NMR(400MHz,CDCl3,δ[ppm]):8.73(4H),8.42(4H),8.09(4H),8.05(H),7.85-7.70(8H),7.63(1H),7.40(2H),6.88(4H)，2.35-2.32(24H)。

example 15: synthesis of Compound C15

This example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloro-terephthalonitrile of the first step is exchanged for an equivalent amount of 2, 4-dichloro-1, 3-benzenedinitrile. Mass spectrometry analysis: MALDI-TOF-MS m/z: 944.6. Elemental analysis: theoretical values of C81.3%, H3.8%, N14.8%; the experimental value C is 81.3 percent,H 3.7％，N 14.6％。¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.55-8.53(8H),8.43(4H),8.11-8.09(5H),8.04(1H),7.94(4H),7.40(2H),7.35-7.20(12H)。

Example 16: synthesis of Compound C16

this example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloro-terephthalonitrile of the first step is exchanged for an equivalent amount of 2, 4-dichloro-1, 3-benzenedinitrile. The 9H-alpha-carboline of the second step needs to be changed into 9H-3, 6-dimethyl-alpha-carboline with the same quantity. Mass spectrometry analysis: MALDI-TOF-MS m/z: 1056.4. Elemental analysis: theoretical values of C81.8%, H5.0%, N13.3%; the experimental values are C81.6%, H4.9% and N13.2%.¹H-NMR(400MHz,CDCl3,δ[ppm]):8.73(4H),8.42(4H),8.11-8.09(4H),8.04(H),7.85-7.70(8H),7.40(2H),6.88(4H),2.35-2.32(24H)。

example 16: synthesis of Compound C16

This example is essentially the same as synthetic example 2, except that: in this case, the 2, 5-dichloro-terephthalonitrile of the first step is exchanged for an equivalent amount of 2, 4-dichloro-1, 3-benzenedinitrile. The 9H-alpha-carboline of the second step needs to be changed into 9H-3, 6-dimethyl-alpha-carboline with the same quantity. Mass spectrometry analysis: MALDI-TOF-MS m/z: 1056.4. Elemental analysis: theoretical values of C81.8%, H5.0%, N13.3%; the experimental values are C81.6%, H4.9% and N13.2%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.73(4H),8.42(4H),8.11-8.09(4H),8.04(H),7.85-7.70(8H),7.40(2H),6.88(4H),2.35-2.32(24H)。

Example 17: synthesis of Compound C17

This example is substantially the same as synthetic example 1 except that: in this case, the 4-chloro-1, 3-benzenedinitrile of the first step is replaced by an equivalent amount of 2,4, 6-tricyanobenzene. Mass spectrometry analysis: MALDI-TOF-MS m/z: 561.2. Elemental analysis: theoretical values of C79.1%, H3.4%, N17.5%; the experimental values are C79.2%, H3.5%, N17.2%.¹H-¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.55(4H),8.43(2H),8.16(2H),7.94(2H),7.87(2H),7.41(1H),7.35-7.20(6H)。

Example 18: synthesis of Compound C18

This embodiment andSynthetic example 2 is essentially the same except that: in this case, the 4-chloro-1, 3-benzenedinitrile in the first step is changed to an equivalent amount of 2-chloro-5-trifluoromethylbenzonitrile; the 2, 4-difluorophenylboronic acid was exchanged for an equivalent amount of 2, 4-difluoro-4-methylphenylboronic acid. Mass spectrometry analysis: MALDI-TOF-MS m/z: 593.2. Elemental analysis: theoretical values of C74.2%, H3.8%, N11.8%, F9.6%; the experimental values C74.1%, H3.7%, N11.7%, F9.6%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.52(4H),8.44(2H),8.39(1H),7.97-7.94(5H),7.90(1H),7.35-7.20(6H),2.34(3H)。

Example 19: synthesis of Compound C19

A100 mL flask was charged with 9H- α -carboline (0.80g, 4.8mmol) and 50mL dry tetrahydrofuran, followed by addition of NaH (0.18g, 7.5mmol), stirring under nitrogen for 20min, then addition of 2' -cyano-2, 4-dichlorobenzophenone (1g, 3.6mmol), and heating to 75 deg.C under nitrogen reflux for 24H. After cooling to room temperature, the aqueous phase was separated and the organic phase was spin-dried, and the product was purified by silica gel column chromatography using 1:1 dichloromethane-petroleum ether as eluent to give 1.28g of a white solid in 73% yield. Mass spectrometry analysis: MALDI-TOF-MS m/z: 539.1. Elemental analysis: theoretical values of C80.1%, H3.9%, N13.0%, O3.0%; the experimental values are C80.0%, H3.8%, N12.8% and O3.1%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.60(2H),8.54-8.52(4H),8.43(2H),7.96-7.94(3H),7.83-7.75(3H),7.63(1H),7.36-7.20(6H)。

Example 20: synthesis of Compound C20

This example is substantially the same as synthetic example 19 except that: in this case, the 4-chloro-1, 3-benzenedinitrile in the first step is replaced by an equal amount of 42' -cyano-2, 4-dichlorodiphenyl sulfone. Mass spectrometry analysis: MALDI-TOF-MS m/z: 559.1. Elemental analysis: theoretical values of C73.0%, H3.7%, N12.2%, S5.6%, O5.6%; the experimental values are C72.6%, H3.8%, N12.3%, S5.6%, and O5.6%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.55(4H),8.43(2H),8.09(2H),8.01(1H),7.94(2H),7.81-7.79(2H),7.63(1H),7.44(1H),7.35-7.20(6H)。

Example 21: synthesis of Compound C21

This example is substantially the same as synthetic example 1 except that: in this case, the 4-chloro-1, 3-benzenedinitrile of the first step is replaced by an equal amount of 4' -chloro-1, 4-dicyanobenzene. Mass spectrometry analysis: MALDI-TOF-MS m/z: 612.2. Elemental analysis: theoretical values of C82.3%, H4.0%, N13.7%; the experimental values are C82.6%, H3.9% and N13.3%.¹H-NMR(400MHz,CDCl₃,δ[ppm]):8.55(4H),8.43(2H),8.15(1H),8.10-8.09(3H),7.94(2H),7.57(1H),7.39(1H),7.35-7.20(10H)。

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims

1. An organic electroluminescent device comprising a cathode, an anode and an organic thin film layer comprising at least one layer comprising a light-emitting layer and disposed between the cathode and the anode, characterized in that at least one of the organic thin film layers comprises a compound represented by the following general formula (1) singly or as a component of a mixture:

In the general formula (1), X is selected from nitrogen atom or R¹bound carbon atoms, i.e. CR¹，C₁To C₅Are each independently selected from the group consisting of²Bonded to each otherCarbon atom or CR²Said R is¹And R²Each independently selected from a hydrogen atom, a cyano group, a straight or fluorinated alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms;

when R is¹And R²When the substituents are respectively and independently selected from substituted aromatic hydrocarbon groups or heteroaromatic hydrocarbon groups, the substituents on the substituents are independently selected from trifluoromethyl, cyano, alkyl or cycloalkyl with 1 to 10 carbon atoms, alkenyl, alkoxy or thioalkoxy groups, or are independently selected from monocyclic or fused ring aryl containing a heteroatom selected from N, O, S, Si and having 4 to 15 ring carbon atoms;

Said C is₁To C₅At least 1 of which is a carbon atom bonded to a cyano group;

And C₁To C₅1 or 2 of which are selected from carbon atoms bonded to the group Q via a dotted line, or from carbon atoms bonded to the group Q through a group L, which is a divalent group selected from an alkylene group having 1 to 20 carbon atoms, a carbonyl group (-CO-), a sulfoxide group (-SO-), a sulfone group (-SO-)₂-) or phenylene;

In the general formula (2), X₁To X₄Each independently selected from a nitrogen atom, a carbon atom bonded to a hydrogen atom, and R³Bound carbon atoms, i.e. CR³And X₁To X₄At least one of them is selected from nitrogen atoms;

The R is³Selected from a linear alkyl group having from 1 to 20 carbon atoms, a branched or cyclic alkyl group having from 3 to 20 carbon atoms, a trifluoromethyl group or a bromine atom;

2. The organic electroluminescent device according to claim 1, wherein the organic thin film layer comprises compounds having a general structural formula:

In the formula (1), the C₁To C₅1 to 3 of (a) are carbon atoms bonded to a cyano group;

X in the formula (2)₁to X₄In (1) is only X₁or X₃Selected from nitrogen atoms.

3. the organic electroluminescent device according to claim 1 or 2, wherein the compound contained in the organic thin film layer has a general structural formula selected from the group consisting of the following formulas (1-1), (1-2) and (1-3):

In the formulae (1-1), (1-2) and (1-3), Q is synonymous with the general formula (1), in the formula (1-1), L is synonymous with the general formula (1), in the formula (1-3), X is synonymous with the general formula (1);

A₁To A₅Each independently selected from a cyano group, a hydrogen atom, a straight-chain alkyl group or a fluoroalkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms, and A₁To A₅At least one is selected from cyano;

When A is₁To A₅And when the substituents are respectively and independently selected from substituted aromatic hydrocarbon groups or heteroaromatic hydrocarbon groups, the substituents on the substituents are respectively and independently selected from trifluoromethyl, cyano, alkyl, cycloalkyl and alkenyl with 1 to 10 carbon atoms, or monocyclic or condensed ring aryl containing a heteroatom selected from N, O, S, Si and having 4 to 15 ring carbon atoms.

4. The organic electroluminescent device according to claim 3, wherein the compound contained in the organic thin film layer has a general structural formula selected from the group consisting of the following formulae (1-11), (1-21), and (1-31):

In the formulae (1-11), (1-21) and (1-31), A₁to A₄The same as defined in the general formulae (1-1), (1-2) and (1-3);

in the formulae (1-31), X is the same as in the general formula (1);

M₁And M₂Each independently selected from a straight chain alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a trifluoromethyl group, or a bromine atom.

5. The organic electroluminescent device according to claim 1 or 2, wherein the compound contained in the organic thin film layer has a general structural formula selected from the group consisting of the following formulae (1-11), (1-21), and (1-31):

In the formulae (1-11), (1-21) and (1-31), A₁To A₄Each independently selected from a cyano group, a hydrogen atom, a straight-chain alkyl group or a fluoroalkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms, and A₁To A₄At least one ofIs selected from cyano;

When A is₁To A₄When the substituents are respectively and independently selected from substituted aromatic hydrocarbon groups or heteroaromatic hydrocarbon groups, the substituents on the substituents are independently selected from trifluoromethyl, cyano, alkyl, cycloalkyl and alkenyl with 1 to 10 carbon atoms, or are independently selected from monocyclic or condensed ring aryl containing a heteroatom selected from N, O, S, Si and having 4 to 15 ring carbon atoms;

In the formulae (1-31), X is the same as in the general formula (1);

6. A compound of the general formula (1):

In the general formula (1), X is selected from nitrogen atom or R¹Bound carbon atoms, i.e. CR¹，C₁To C₅are each independently selected from the group consisting of²bound carbon atoms, i.e. CR²Said R is¹and R²Each independently selected from a hydrogen atom, a cyano group, a straight or fluorinated alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms;

Said C is₁To C₅At least 1 of which is substituted with cyanoA bonded carbon atom;

In the general formula (2), X₁To X₄Each independently selected from a nitrogen atom, a carbon atom bonded to a hydrogen atom, and R³Bound carbon atoms, i.e. CR³And X₁To X₄At least one of which is a nitrogen atom;

The R is³Selected from linear alkyl groups having from 1 to 20 carbon atoms, branched or cyclic alkyl groups having from 3 to 20 carbon atoms, trifluoromethyl, bromine atoms;

7. A compound of formula (la) according to claim 6, wherein:

C in the formula (1)₁To C₅1 to 3 of (a) are carbon atoms bonded to a cyano group;

8. A compound of formula (la) according to claim 6, wherein in formula (1):

The R is¹、R²And R³Each independently selected from: methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octylChloromethyl, 1-chloroethyl, 2-chloroethyl, 1, 2-dichloroethyl, 2, 3-dichloro-tert-butyl, bromomethyl, 1, 2-dibromoethyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl;

or said R is¹And R²Each independently selected from: phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 4-phenanthryl, 9-phenanthryl, 1-tetracenyl, 2-tetracenyl, 9-tetracenyl, 1-pyrenyl, 2-pyrenyl, 4-pyrenyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, p-terphenyl-4-yl, p-terphenyl-3-yl, m-terphenyl-4-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p-tert-butylphenyl, p- (2-phenylpropyl) phenyl, 3-methyl-2-naphthyl, 4-methyl-1-naphthyl, 4-methyl-1-anthracenyl, 4' -methylbiphenyl;

Or said R is¹And R²Each independently selected from: 1-pyridine, 2-pyridyl, 3-pyridyl, 2-quinolyl, 3-quinolyl, 6-quinolyl, 3-isoquinolyl, 2-quinoxalyl, 5-quinoxalyl, 1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 9-carbazolyl, 1-phenanthridinyl, 9-phenanthridinyl.

9. A compound of formula (la) according to claim 6 or 7, having a general structural formula selected from the following formulae (1-1), (1-2) or (1-3):

A₁to A₄each independently selected from a cyano group, a hydrogen atom, a straight chain alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms, and A₁To A₄One or both of which are simultaneously selected from cyano;

When A is₁To A₄and when the substituents are respectively and independently selected from substituted aromatic hydrocarbon groups or heteroaromatic hydrocarbon groups, the substituents on the substituents are respectively and independently selected from trifluoromethyl, cyano, alkyl, cycloalkyl and alkenyl with 1 to 10 carbon atoms, or monocyclic or condensed ring aryl containing a heteroatom selected from N, O, S, Si and having 4 to 15 ring carbon atoms.

10. A compound of formula (la) according to claim 9, having a formula selected from the following formulae (1-11), (1-21) or (1-31):

In the formulae (1-11), (1-21) and (1-31), A₁To A₄The same as defined in the general formulae (1-1), (1-2) and (1-3); in the formulae (1-31), X is the same as in the general formula (1);

M₁And M₂Each independently selected from a carbon atom bonded to a hydrogen atom, and R⁴Bound carbon atoms, i.e. CR⁴Said R is⁴Selected from a linear alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a trifluoromethyl group or a bromine atom.

11. A compound of formula (la) according to claim 6 or 7, having a general structural formula selected from the following formulae (1-11), (1-21) or (1-31):

In the formulae (1-11), (1-21) and (1-31), A₁To A₄Each independently selected from a cyano group, a hydrogen atom, a straight-chain alkyl group or a fluoroalkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms, and A₁To A₄At least one is selected from cyano;

In the formulae (1-31), X is the same as in the general formula (1);

12. a compound of formula (la) according to claim 6, selected from the following specific formulae: