阅读说明：本技术 一种化合物及包含该化合物的有机电致发光器件 (Compound and organic electroluminescent device containing same ) 是由 杜明珠 刘辉 鲁秋 邵钰杰 苗玉鹤 于 2020-06-28 设计创作，主要内容包括：本发明提供一种化合物及包含该化合物的有机电致发光器件,涉及有机电致发光技术领域。本发明提供的化合物,首先,可以减少分子间的π-π堆积,作为发光辅助层材料使用,能够降低发光层和阳极界面之间的能级差,有利于实现在发光层内的电荷均衡,并且具有较高的玻璃化温度和热稳定性。其次,可以有效的阻挡电子从发光层向空穴传输层扩散,实现发光层内的电荷均衡,将激子限制在发光层内,避免界面发光现象的发生。本发明还提供一种机电致发光器件,具有高的发光效率和优异的寿命表现。(The invention provides a compound and an organic electroluminescent device containing the compound, and relates to the technical field of organic electroluminescence. The compound provided by the invention can reduce the pi-pi accumulation among molecules, can be used as a light-emitting auxiliary layer material, can reduce the energy level difference between a light-emitting layer and an anode interface, is favorable for realizing charge balance in the light-emitting layer, and has higher glass transition temperature and thermal stability. And secondly, electrons can be effectively prevented from diffusing from the light-emitting layer to the hole transport layer, so that charge balance in the light-emitting layer is realized, excitons are limited in the light-emitting layer, and the interface light-emitting phenomenon is avoided. The present invention also provides an organic electroluminescent device having high luminous efficiency and excellent life performance.)

1. A compound having a structure represented by formula (I) or formula (II):

wherein M has a structure represented by the following formula (III);

x is O, S, C (R)₄)(R₅) Or N (R)₆)；

R₄、R₅、R₆Independently selected from H, C1-C15 alkyl or C6-C30 aryl, or R₄、R₅Bonding to form a ring structure;

R₁、R₂independently selected from H, C1-C15 alkyl or C6-C30 aryl, or two adjacent R₁、R₂Bonding to form a ring structure;

R₃selected from H, C1-C15 alkyl or C6-C30 aryl, or two adjacent R₃Bonding to form a ring structure;

p is 0, 1,2 or 3, q is 0, 1,2, 3 or 4, n is 0, 1,2, 3 or 4;

L₁arylene selected from single bond or C6-C30;

L₂、L₃independently selected from arylene of C6-C30;

Ar₁、Ar₂、Ar₃、Ar₄、Ar₅independently selected from aryl of C6-C30 or heteroaryl of C3-C30;

the aryl group, the arylene group and the heteroaryl group are each substituted or unsubstituted with one or more substituents selected from the group consisting of a deuterium atom, an alkyl group having from C1 to C4, an aryl group having from C6 to C30 and a heteroaryl group having from C3 to C20, and when the substituents are substituted with a plurality of substituents, the substituents may be the same or different from one another.

2. A compound according to claim 1, wherein M is selected from any one of the following groups:

3. a compound according to claim 1, wherein L is₁Selected from a single bond or any of the following groups:

4. a compound according to claim 1, wherein Ar is Ar₁Any one selected from the following groups:

5. a compound according to claim 1, wherein L is₂、L₃Independently selected from any one of the following groups:

6. a compound according to claim 1, wherein Ar is Ar₂、Ar₃、Ar₄、Ar₅Independently selected from any one of the following groups:

7. a compound according to claim 1, selected from any one of the following compounds:

8. an organic electroluminescent device comprising a cathode, an organic layer, an anode and a substrate, wherein the organic layer contains the compound according to any one of claims 1 to 7.

9. The organic electroluminescent device according to claim 8, wherein the organic layer contains a light-emitting auxiliary layer containing the compound according to any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of organic electroluminescence, in particular to a compound and an organic electroluminescent device containing the compound.

Background

An Organic Light-Emitting Diode (OLED) is an all-solid-state Light-Emitting device, and has the advantages of high brightness, high contrast, high definition, wide viewing angle, wide color gamut, ultra-thinness, ultra-Light, low power consumption, wide temperature, self-luminescence, high luminous efficiency, short reaction time, transparency, flexibility, and the like, and is already commercially available in the fields of mobile phones, televisions, micro displays, and the like, and is called as a "illusion display" by the people in the industry, and will become a novel display technology with the most development potential in the future.

The light emitting mechanism of the organic electroluminescent device is: when a voltage is applied between the anode and the cathode, electrons are injected from the cathode side, holes are injected from the anode side, the electrons and the holes are combined in the light-emitting layer to form excitons (exiton), and the excitons are restored from an excited state to a ground state, so that light is emitted, and electric energy is directly converted into light energy of organic semiconductor material molecules. However, due to the difference in the transport speed of holes and electrons, the carriers in the light-emitting layer are mismatched, thereby affecting the light-emitting performance of the device. Therefore, the development of a material which can balance current carriers and has good thermal stability so as to improve the performance of the organic electroluminescent device in efficiency, service life and the like has important significance.

Disclosure of Invention

In view of the above problems in the prior art, the present invention provides a compound and an organic electroluminescent device comprising the same.

The invention provides a compound, which has a structure shown as the following formula (I) or formula (II):

wherein M has a structure represented by the following formula (III);

x is O, S, C (R)₄)(R₅) Or N (R)₆)；

R₄、R₅、R₆Independently selected from H, C1-C15 alkyl or C6-C30 aryl, or R₄、R₅Bonding to form a ring structure;

R₁、R₂independently selected from H, C1-C15 alkyl or C6-C30 aryl, or two adjacent R₁、R₂Bonding to form a ring structure;

R₃selected from H, C1-C15 alkyl or C6-C30 aryl, or two adjacent R₃Bonding to form a ring structure;

p is 0, 1,2 or 3, q is 0, 1,2, 3 or 4, n is 0, 1,2, 3 or 4;

L₁arylene selected from single bond or C6-C30;

L₂、L₃independently selected from arylene of C6-C30;

Ar₁、Ar₂、Ar₃、Ar₄、Ar₅independently selected from aryl of C6-C30 or heteroaryl of C3-C30;

the aryl group, the arylene group and the heteroaryl group are each substituted or unsubstituted with one or more substituents selected from the group consisting of a deuterium atom, an alkyl group having from C1 to C4, an aryl group having from C6 to C30 and a heteroaryl group having from C3 to C20, and when the substituents are substituted with a plurality of substituents, the substituents may be the same or different from one another.

The invention also provides an organic electroluminescent device which comprises a cathode, an organic layer, an anode and a substrate, wherein the organic layer contains the compound.

The invention has the beneficial effects that:

the invention provides a compound, wherein an M group with a three-dimensional non-planar structure is introduced into a structure, so that the pi-pi accumulation among molecules can be reduced, the compound has a proper highest occupied molecular orbital energy level, and the compound is used as a light-emitting auxiliary layer material between a hole transport layer and a light-emitting layer, so that the energy level difference between the light-emitting layer and an anode interface can be reduced, and the charge balance in the light-emitting layer can be realized. And secondly, the M group has certain distortion on a spatial three-dimensional structure, so that the film forming property of the compound can be improved, and the stability of the compound is better. Thirdly, the special cyclic structure of the M group enables the compound to have higher glass transition temperature and thermal stability.

Furthermore, the compound of the invention introduces substituents with rigidity and large pi conjugated system such as fluorene, furan/thiophene, carbazole and the like, so that the compound has good thermal stability and higher carrier mobility, and can effectively prevent electrons from diffusing from the luminescent layer to the hole transport layer through the synergistic effect between M group and the substituents, thereby realizing charge balance in the luminescent layer, limiting excitons in the luminescent layer and avoiding the occurrence of interface luminescence phenomenon.

The present invention also provides an organic electroluminescent device having high luminous efficiency and excellent life performance.

Drawings

FIG. 1 shows the compound prepared in example 1 of the present invention¹H NMR chart.

FIG. 2 shows the compound prepared in example 5 of the present invention¹H NMR chart.

FIG. 3 shows the compound prepared in example 6 of the present invention¹H NMR chart.

FIG. 4 shows the compound prepared in example 10 of the present invention¹H NMR chart.

FIG. 5 shows the compound prepared in example 14 of the present invention¹H NMR chart.

FIG. 6 shows the compound prepared in example 15 of the present invention¹H NMR chart.

FIG. 7 shows a compound prepared in example 16 of the present invention¹H NMR chart.

FIG. 8 shows a compound prepared in example 17 of the present invention¹H NMR chart.

Detailed Description

The following will clearly and completely describe the technical solutions of the specific embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of protection of the present invention.

The invention firstly provides a compound which has a structure shown as a formula (I) or a formula (II):

wherein M has a structure represented by the following formula (III);

x is O, S, C (R)₄)(R₅) Or N (R)₆)；

R₄、R₅、R₆Independently selected from H, C1-C15 alkyl or C6-C30 aryl, or R₄、R₅Bonding to form a ring structure;

R₁、R₂independently selected from H, C1-C15 alkyl or C6-C30 aryl, or two adjacent R₁、R₂Bonding to form a ring structure;

R₃selected from H, C1-C15 alkyl or C6-C30 aryl, or two adjacent R₃Bonding to form a ring structure; preferably, a C5-C20 monocyclic or polycyclic ring is formed.

p is 0, 1,2 or 3, q is 0, 1,2, 3 or 4, n is 0, 1,2, 3 or 4;

L₁arylene selected from single bond or C6-C30;

L₂、L₃independently selected from arylene of C6-C30;

Ar₁、Ar₂、Ar₃、Ar₄、Ar₅independently selected from aryl of C6-C30 or heteroaryl of C3-C30;

the aryl group, the arylene group and the heteroaryl group are each substituted or unsubstituted with one or more substituents selected from the group consisting of a deuterium atom, an alkyl group having from C1 to C4, an aryl group having from C6 to C30 and a heteroaryl group having from C3 to C20, and when the substituents are substituted with a plurality of substituents, the substituents may be the same or different from one another. The substituent may include, by way of example, deuterium atom, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, phenyl group, biphenyl group, terphenyl group, naphthyl group, anthracenyl group, phenanthrenyl group, benzophenanthrenyl group, perylenyl group, pyrenyl group, fluorenyl group, 9-dimethylfluorenyl group, dianilinyl group, carbazolyl group, 9-phenylcarbazolyl group, furyl group, thienyl group, phenothiazinyl group, phenoxazinyl group, acridinyl group, pyridyl group, pyrazinyl group, triazinyl group, pyrimidinyl group, etc., but is not limited thereto, and may be a substituent other than those listed above as long as the technical effects of the present invention can be achieved. The substituent may be one or more, and when the substituent is plural, plural substituents may be the same or different.

The alkyl group in the present invention refers to a hydrocarbon group obtained by dropping one hydrogen atom from an alkane molecule, and it may be a straight-chain alkyl group, a branched-chain alkyl group, or a cyclic alkyl group, and preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Examples may include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, cyclopentyl, cyclohexyl, and the like, but are not limited thereto.

The aryl group in the present invention is a general term for a monovalent group remaining after one hydrogen atom is removed from an aromatic nucleus carbon of an aromatic compound molecule, and the number of aryl carbon atoms is preferably C6 to C30, more preferably C6 to C20, and still more preferably C6 to C12, and may be a monocyclic aryl group, a polycyclic aryl group, or a fused ring aryl group. The monocyclic aryl group means an aryl group having only one aromatic ring in the molecule, for example, phenyl group and the like, but is not limited thereto; the polycyclic aromatic group means an aromatic group having two or more independent aromatic rings in the molecule, for example, biphenyl group, terphenyl group and the like, but is not limited thereto; the fused ring aryl group refers to an aryl group having two or more aromatic rings in a molecule and fused together by sharing two adjacent carbon atoms, and examples thereof include, but are not limited to, naphthyl, anthryl, phenanthryl, fluorenyl, benzofluorenyl, pyrenyl, triphenylenyl, fluoranthenyl, spirobifluorenyl, and the like.

The arylene group in the present invention refers to a general term of divalent groups remaining after two hydrogen atoms are removed from the aromatic core carbon of a substituted or unsubstituted aromatic compound molecule, and may be monocyclic arylene group, polycyclic arylene group or fused ring arylene group. The monocyclic arylene group includes phenylene group and the like, but is not limited thereto; the polycyclic arylene group includes, but is not limited to, biphenylene, terphenylene, and the like; the condensed ring arylene group includes naphthylene, anthrylene, phenanthrylene, fluorenylene, pyrenylene, triphenylene, fluoranthenylene, phenylfluorenylene, and the like, but is not limited thereto.

The heteroaryl group in the invention refers to a general term of a group obtained by replacing one or more aromatic nucleus carbon atoms in an aryl group by heteroatoms, including but not limited to oxygen, sulfur, nitrogen or phosphorus atoms, the connecting site of the heteroaryl group can be positioned on ring-forming carbon atoms or ring-forming heteroatoms, wherein the number of carbon atoms is preferably C3-C30, further preferably C3-C20, more preferably C3-C12, and the heteroaryl group can be monocyclic heteroaryl, polycyclic heteroaryl or fused ring heteroaryl. The monocyclic heteroaryl group includes pyridyl, pyrimidyl, triazinyl, furyl, thienyl, pyrrolyl, imidazolyl and the like, but is not limited thereto; the polycyclic heteroaryl group includes bipyridyl, phenylpyridyl, and the like, but is not limited thereto; the fused ring heteroaryl group includes quinolyl, isoquinolyl, indolyl, phenanthrolinyl, dibenzofuranyl, dibenzothienyl, carbazolyl, benzocarbazolyl, acridinyl, 9, 10-dihydroacridinyl, phenoxazine, xanthenyl, thianthrenyl and the like, but is not limited thereto.

Preferably, M is selected from any one of the following groups:

further preferably, M is selected from any one of the following groups:

preferably, in the formula (I), L₁Selected from a single bond or any of the following groups:

further preferred, L₁Selected from a single bond or any of the following groups:

preferably, in the formula (I), Ar₁Any one selected from the following groups:

preferably, in the formula (II), L₂、L₃Independently selected from any one of the following groups:

further preferred, L₂、L₃Independently selected from any one of the following groups:

preferably, Ar is₂、Ar₃、Ar₄、Ar₅Independently selected from any one of the following groups:

。

preferably, the compound is selected from any one of the following compounds:

while specific structural forms of the compounds of the present invention have been illustrated above, the present invention is not limited to these listed chemical structures, and any substituent group as defined above is included on the basis of the structure represented by formula (I) or formula (II).

The preparation method of the compound of the present invention can be prepared by a coupling reaction which is conventional in the art, and can be prepared by the following synthetic routes, for example, but the present invention is not limited thereto:

compound (A) with Ar₁The aromatic amine compound of (a) is subjected to Buchwald reaction to obtain an intermediate (A-1); intermediate (A-1) with a further compound containing a group MCarrying out Buchwald reaction on bromide to finally obtain a target compound shown as a formula (I);

containing Ar₂、Ar₃With a compound containing Ar₄、Ar₅The aromatic amine compound of (a) undergoes a Buchwald reaction to obtain an intermediate (A-2); and carrying out Buchwald reaction on the intermediate (A-2) and bromide containing the group M to finally obtain the target compound shown as the formula (II).

The bromides containing the group M can be prepared, but the invention is not limited thereto, by the following synthetic route:

the aniline compound and paraformaldehyde are condensed in trifluoroacetic acid to obtain an intermediate B, and the intermediate B reacts with NBS to generate bromide containing a group M.

Wherein, the definition of each substituent is as described above, and the description is omitted.

The reaction conditions for the above reactions are not particularly limited in the present invention, and those well known to those skilled in the art may be used. The starting materials used in the above reactions are not particularly limited in the present invention, and may be commercially available products or prepared by methods known to those skilled in the art. The compound provided by the invention has the advantages of few synthesis steps, simple treatment and easiness in industrial production.

The invention also provides an organic electroluminescent device which comprises a cathode, an organic layer, an anode and a substrate, wherein the organic layer contains the compound.

Preferably, the organic layer contains a light-emitting auxiliary layer containing the compound.

Regarding the organic electroluminescent device of the present invention, the organic layers may include a hole injection layer, a hole transport layer, a light emission auxiliary layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, however, the structure of the organic electroluminescent device of the present invention is not limited by the above structure, and a plurality of organic layers may be omitted or simultaneously provided if necessary. For example, organic layers having the same function may be made into a stacked structure of 2 or more layers, for example, the hole transport layer may further include a first hole transport layer and a second hole transport layer, and the electron transport layer may further include a first electron transport layer and a second electron transport layer.

With regard to the organic electroluminescent device of the present invention, any material used for the layer as in the prior art can be used for the other layers except that the luminescence auxiliary layer contains the compound represented by (I).

As the anode of the organic electroluminescent device of the present invention, a material having a large work function can be used, and examples thereof include: metals such as vanadium, chromium, copper, zinc, gold, or alloys thereof; metal oxides such as zinc oxide, Indium Tin Oxide (ITO), and Indium Zinc Oxide (IZO); combinations of metals with oxides, e.g. ZnO: Al or SnO₂Sb; conductive polymers, e.g. poly (3-methyl compounds), poly [3,4- (ethylene-1, 2-dioxy) compounds](PEDOT), polypyrrole, polyaniline, and the like, but are not limited thereto.

As the cathode of the organic electroluminescent device of the present invention, a material having a small work function can be used, and examples thereof include: metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead, or alloys thereof; materials of multilayer construction, e.g. LiF/Al or LiO₂Al, etc., but are not limited thereto.

As for the light emitting layer of the organic electroluminescent device of the present invention, a red light emitting material, a green light emitting material, or a blue light emitting material can be used as the light emitting material, and two or more light emitting materials can be mixed and used if necessary. The light-emitting material may be a host material alone or a mixture of a host material and a dopant material, and the light-emitting layer is preferably formed using a mixture of a host material and a dopant material.

The hole transport layer of the organic electroluminescent device of the present invention is required to have a suitable ion potential and a high hole mobility, and an organic material based on arylamine, a conductive polymer, a block copolymer having both a conjugated portion and a non-conjugated portion, and the like can be used, but the present invention is not limited thereto. Examples thereof include: 4,4 '-bis [ N- (1-naphthyl) -N-phenylamino ] biphenyl (NPB), 4,4,4 ″ -tris (N-carbazolyl) triphenylamine (TCTA), N' -bis (3-methylphenyl) -N, N '-diphenyl- [1, 1-biphenyl ] -4,4' -diamine (TPD), N '-bis (naphthalen-1-yl) -N, N' -diphenylbenzidine (a-NPD), and the like.

The electron transport layer of the organic electroluminescent device of the present invention is required to have a high electron affinity for an electron transport material, to be capable of efficiently transporting electrons, and to be less likely to generate impurities that act as traps during production and use. The electron-transporting material used in the electron-transporting layer is not particularly limited, and examples thereof include (1) metal complexes such as aluminum complexes, beryllium complexes, and zinc complexes, (2) aromatic heterocyclic compounds such as imidazole derivatives, benzimidazole derivatives, and phenanthroline derivatives, and (3) polymer compounds, but the invention is not limited thereto. Examples thereof include: tris (8-hydroxyquinoline) aluminum (Alq)₃) Phenanthroline derivatives such as 1,3, 5-tris (1-naphthyl-1H-benzimidazol-2-yl) benzene (TPBI) and 4, 7-diphenyl-1, 10-phenanthroline (BPhen).

The electron injection layer of the organic electroluminescent device of the present invention is mainly used for improving the efficiency of injecting electrons from the cathode into the electron transport layer and the light-emitting layer, and is required to have the ability to transport electrons, and an alkali metal salt such as lithium fluoride and cesium fluoride, an alkaline earth metal salt such as magnesium fluoride, a metal oxide such as aluminum oxide, or the like can be used.

The present invention is not particularly limited to the thickness of each organic layer of the organic electroluminescent device, and may be any thickness commonly used in the art.

The organic electroluminescent device can be prepared by various methods such as solution coating such as spin coating and ink-jet printing or vacuum evaporation.

The starting materials used in the following examples are not particularly limited in their source, and may be commercially available products or prepared by methods known to those skilled in the art.

The mass spectrum used by the compound of the invention uses AXIMA-CFRplus matrix assisted laser desorption ionization flight mass spectrometer of Kratos Analytical company of Shimadzu corporation, and chloroform is used as a solvent;

elemental analysis using a Vario EL cube type organic element analyzer of Elementar corporation, Germany, the sample mass was 5 mg;

nuclear magnetic resonance (¹HNMR) Using a Bruker-510 type nuclear magnetic resonance spectrometer (Bruker, Germany), 600MHz, CDCl₃As solvent, TMS as internal standard.