Pyrrole derivative and organic electroluminescent element containing pyrrole derivative

Abstract

The invention provides a pyrrole derivative, belongs to the technical field of organic electroluminescence, and also relates to an application of the compound in an organic electroluminescence device. The pyrrole derivative is characterized in that the compound has a structure as shown in a formula (1): # imgabs0 #, and an organic electroluminescent device containing the pyrrole derivative can effectively improve the balance of holes and electrons in a luminescent layer and improve the current efficiency of the device.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic electroluminescence, and particularly relates to a pyrrole derivative and the application of the compound in an organic electroluminescent device. Background Art

[0002] An organic light emitting diode is a self-luminous display device based on organic electroluminescent materials. Different from existing liquid crystal display devices, it has the characteristics of not requiring a backlight source and being thin, and is a technology suitable for flexible device devices (flexible light emitting display devices). An organic light emitting diode usually has a structure including an anode, a cathode, and an organic material layer therebetween. The organic material layer is usually composed of a multi-layer structure formed by various different substances. For example, it is composed of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, etc., which can enable the carriers of holes and electrons to recombine in the light emitting layer. The carriers recombine to generate excitons, and these excitons transition from the excited state to the ground state to generate light.

[0003] Since the excitons generated in the light emitting layer will move towards the hole transport layer, ultimately resulting in light emission at the interface between the hole transport layer and the organic light emitting layer, there is a problem of reduced light emission efficiency. Therefore, in order to improve the efficiency of the organic light emitting layer, it is necessary to add a light emission auxiliary layer between the hole transport layer and the light emitting layer to prevent efficiency roll-off and improve the stability of the device.

[0004] Therefore, developing a compound with excellent hole transport performance and capable of being used in an organic electroluminescent device to improve the current efficiency of the device has very important practical application value. Summary of the Invention

[0005] The purpose of the present invention is to provide a pyrrole derivative, including the application of the compound in an organic electroluminescent device. This compound is more suitable for the hole transport region and can improve the performance of the device.

[0006] A pyrrole derivative, characterized in that the compound has the structure shown in formula (1):

[0007]

[0008] Wherein, L 1 -L 4 each independently selected from a single bond, a substituted or unsubstituted C6-C60 arylene group, a substituted or unsubstituted C3-C60 heteroarylene group,

[0009] Ar 1 -Ar 2Each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 heterocycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl,

[0010] R 1 -R 4 Each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 heterocycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl,

[0011] When the "substituted or unsubstituted" is substituted, the substituents are each independently selected from one or a combination of deuterium, halogen, cyano, C1-C10 alkyl, C3-C10 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl.

[0012] The heteroatoms of the heteroaryl are selected from one or more of O, S, N, P, Si.

[0013] Preferably, the R 1 is selected from phenyl.

[0014] Preferably, the R 2 is selected from phenyl.

[0015] Preferably, the R 3 is selected from phenyl.

[0016] Preferably, the R 4 is selected from phenyl.

[0017] Preferably, the -L 1 -Ar 1 、-L 2 -Ar 2 are the same.

[0018] Preferably, the -L 1 -Ar 1 、-L 2 -Ar 2 are not the same.

[0019] Preferably, the L 1 -L 4Each independently selected from a single bond, a substituted or unsubstituted phenylene, a substituted or unsubstituted biphenylene, a substituted or unsubstituted naphthylene, a substituted or unsubstituted anthrylene, a substituted or unsubstituted phenanthrylene, a substituted or unsubstituted ylene, a substituted or unsubstituted 9,9-dimethylfluorenylene, a substituted or unsubstituted 9,9-diphenylfluorenylene, a substituted or unsubstituted spirobifluorenylene, a substituted or unsubstituted dibenzofuranylene, a substituted or unsubstituted dibenzothiophenylene.

[0020] Preferably, the L 3 and L 4 are not both single bonds at the same time.

[0021] Preferably, the Ar 1 and Ar 2 each independently selected from hydrogen, deuterium, halogen, cyano, a substituted or unsubstituted phenyl, a substituted or unsubstituted biphenyl, a substituted or unsubstituted terphenyl, a substituted or unsubstituted naphthyl, a substituted or unsubstituted phenylnaphthyl, a substituted or unsubstituted anthryl, a substituted or unsubstituted phenanthryl, a substituted or unsubstituted fluoranthenyl, a substituted or unsubstituted pyrenyl, a substituted or unsubstituted perylenyl, a substituted or unsubstituted triphenylene, a substituted or unsubstituted ylene, a substituted or unsubstituted 9,9-dimethylfluorenyl, a substituted or unsubstituted 9,9-diphenylfluorenyl, a substituted or unsubstituted spirobifluorenyl, a substituted or unsubstituted dibenzofuranyl, a substituted or unsubstituted dibenzothiophenyl, a substituted or unsubstituted carbazolyl.

[0022] More preferably, the -L 3 -L 4 - is selected from the following substituted or unsubstituted groups: indicating the connection site.

[0023] More preferably, the -L 1 -Ar 1 and -L 2 -Ar 2 each independently selected from hydrogen and the following substituted or unsubstituted groups:

[0024]

[0025]

[0026] indicating the connection site.

[0027] Preferably, when the "substituted or unsubstituted" is substituted, the substituents are each independently selected from one or more combinations of deuterium, halogen, cyano, methyl, ethyl, tert-butyl, cyclohexyl, phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, pyrenyl, fluoranthenyl, triphenylene, group, dibenzofuranyl, dibenzothiophenyl.

[0028] Use of the pyrrole derivative of the present invention as an organic electroluminescent material.

[0029] An organic electroluminescent device, characterized in that the organic electroluminescent device includes: a cathode, an anode, and one or more organic material layers disposed between the cathode and the anode and including a light-emitting layer, and one or more layers of the organic material layer contain the pyrrole derivative of the present invention.

[0030] Preferably, the organic electroluminescent device includes a substrate, an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode. The light-emitting layer is located between the anode and the cathode. The hole transport region is located between the anode and the light-emitting layer. The electron transport region is located between the light-emitting layer and the cathode. The hole transport region contains the pyrrole derivative of the present invention.

[0031] More preferably, the hole transport region includes a hole injection layer, a hole transport layer, and a light-emitting auxiliary layer. The hole transport layer is located between the hole injection layer and the light-emitting layer. The light-emitting auxiliary layer is located between the hole transport layer and the light-emitting layer. The light-emitting auxiliary layer contains the pyrrole derivative of the present invention.

[0032] An electronic device, including: one or more of a display, a monitor, and a lighting device, including the organic electroluminescent device of the present invention; and a control unit for driving the above display device.

[0033] The beneficial effects of the present invention are:

[0034] The pyrrole derivative of the present invention has a pyrrole structure connected with an amine group and can be used as a material with high hole transport performance in an organic electroluminescent device, effectively improving the balance between holes and electrons in the light-emitting layer and greatly improving the efficiency of the device. Description of the Drawings

[0035] Figure 1 It is a schematic structural diagram of the organic electroluminescent device described in Application Example 1, where 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is a light-emitting auxiliary layer, 6 is a light-emitting layer, 7 is a hole blocking layer, 8 is an electron transport layer, and 9 is a cathode. Detailed Embodiments

[0036] To more fully describe the present invention to those skilled in the art, embodiments of the present invention are provided. The scope of the present invention is not limited to the following embodiments. These embodiments can make the present invention more thorough and complete, and fully convey the concept of the present invention to those skilled in the art.

[0037] The present disclosure can be more readily understood by reference to the following detailed embodiments and the examples contained therein. Before disclosing and describing the compounds, devices, and / or methods of the present invention, it should be understood that, unless otherwise specified, they are not limited to specific synthetic methods or specific reagents, as these can vary. It should also be understood that the terms used in the present invention are only for describing specific aspects and are not intended to be limiting. Although any methods and materials similar or equivalent to those described in the present invention can be used in the practice or testing thereof, exemplary methods and materials are now described.

[0038] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; unless otherwise specified, the reagents, materials, etc. used in the following examples can all be obtained from commercial sources.

[0039] As used in the present invention, the term "halogen" can include fluorine, chlorine, bromine, or iodine.

[0040] As used in the present invention, the term "C1-C10 alkyl" refers to a monovalent substituent derived from a straight-chain or branched-chain saturated hydrocarbon having 1 to 10 carbon atoms, and examples thereof include, but are not limited to, methyl, ethyl, propyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, and hexyl.

[0041] As used in the present invention, the term "C3-C10 cycloalkyl" refers to a monovalent substituent derived from a monocyclic or polycyclic non-aromatic hydrocarbon having 3 to 10 carbon atoms. Examples of such cycloalkyls include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, adamantane, etc.

[0042] As used in the present invention, the term "C2-C10 heterocycloalkyl" has a monovalent substituent of a monocyclic or polycyclic ring having 2 to 10 carbon atoms, and at least one heteroatom is included in the ring, and the heteroatom is selected from O, S, N, P, Si.

[0043] As used in the present invention, the term "alkoxy" refers to a straight-chain, branched-chain, or cyclic chain. The number of carbon atoms in the alkoxy is not particularly limited herein, but the alkoxy preferably has 1 to 10 carbon atoms. Specific examples thereof include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, neopentyloxy, isopentyloxy, n-hexyloxy, benzyloxy.

[0044] As used in the present invention, the term "aryl having 6 to 60 carbon atoms" refers to a monovalent substituent derived from an aromatic hydrocarbon having a single ring or a combination of two or more rings and having 6 to 60 carbon atoms. Further, such an aryl may have a form in which two or more of the rings are simply linked to each other or fused to each other. Examples of such aryls include, but are not limited to, phenyl, biphenyl, naphthyl, phenanthryl, anthryl, pyrenyl, triphenylenyl, fluoranthenyl, dimethyl 9,9-dimethylfluorene, 9,9-diphenylfluorene, spirobifluorene, and the like.

[0045] As used in the present invention, the term "arylene" refers to a divalent aryl derived by removing one hydrogen atom from "aryl", for example, removing one hydrogen atom from phenyl to form phenylene, and removing one hydrogen atom from naphthyl to form naphthylene.

[0046] As used in the present invention, the term "heteroaryl having 3 to 60 carbon atoms" refers to a monovalent substituent derived from a monocyclic or polycyclic aromatic hydrocarbon having 3 to 60 carbon atoms. In this connection, at least one carbon, preferably 1 to 3 carbons in the ring, is replaced by a heteroatom such as N, O, S, P, B or Si. Further, such a heteroaryl may have a form in which two or more of the rings are simply linked to each other or fused to each other or fused to an aryl. Examples of such heteroaryls include, but are not limited to, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, indolizinyl, indolyl, indolopyridyl, purinyl, phenanthrolinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, thiazolyl, imidazolyl, oxazolyl, furyl, thienyl, benzofuryl, benzothienyl, benzothiazolyl, benzimidazolyl, benzoxazolyl, carbazolyl, dibenzofuryl, dibenzothienyl, and the like, and the present invention is not limited thereto.

[0047] As used in the present invention, the term "heteroarylene" refers to a divalent heteroaryl derived by removing one hydrogen atom from "heteroaryl", for example, removing one hydrogen atom from pyridyl to form pyridylene.

[0048] As used in the present invention, in the expression "Z group having AA - BB carbon atoms" or "Z group of C(AA - BB)", "having AA - BB carbon atoms" means the number of carbon atoms of the Z group when unsubstituted, excluding the carbon atoms of the substituents when substituted. For example, an aryl having 6 to 30 carbon atoms means that when unsubstituted, the number of carbon atoms in the aryl is any integer from 6 to 30, that is, when unsubstituted, the number of carbon atoms can be 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20... 30.

[0049] As used in the present invention, the term "single bond" means that groups are directly linked. For example, in formula (1), where L 1 is a single bond, which means

[0050] As used in the present invention, the term "substituted" means that a hydrogen atom in a compound is replaced by another substituent. The position where substitution occurs can be the position where the hydrogen atom is replaced. That is, the position is not limited to a specific position, as long as the hydrogen at that position can be replaced by a substituent. For example, unless otherwise specified in the present specification, the carbazolyl group includes any of the following groups, but is not limited thereto,

[0051]

[0052] represents the substitution position. "Unsubstituted" means that a hydrogen atom is retained, and in this case, the hydrogen atom includes protium, deuterium, and tritium.

[0053] As used in the present invention, the term "phenylnaphthyl" means

[0054] As used in the present invention, the term "phenylnaphthyl" includes

[0055] refers to the connection position.

[0056] When there are two or more substituents, the two or more substituents can be the same or different.

[0057] As used in the present invention, the hydrogen atom includes protium, deuterium, and tritium. The compounds described in the present invention may contain deuterium atoms of natural origin, or deuterium atoms may be introduced by deuterating a part or all of the starting compounds. If deuterium atoms are introduced from the starting materials, the deuteration rate can be 100%, or less than 100%, or less than 95%, or less than 90%, or less than 80%. The deuteration rate can also be 1% or more, or 5% or more, or 10% or more. If the deuteration rate is not 100%, it represents a mixture of deuterated compounds and non-deuterated compounds, or a mixture of fully deuterated compounds and incompletely deuterated compounds, or a mixture of fully deuterated compounds, non-deuterated compounds, and incompletely deuterated compounds.

[0058] As used in the present invention, terms such as the first, the second, A, B, etc. are used. The above terms are only used to distinguish the constituent elements and do not limit the nature or order of the constituent elements corresponding to the terms.

[0059] As used in the present invention, the term "amine group" means refers to the connection position.

[0060] Organic electroluminescent element

[0061] The structure used in the organic electroluminescent device of the present invention is a disclosed structure, which includes an anode, a cathode, and an organic layer located between the anode and the cathode. The organic layer includes a light-emitting layer, and at least one layer of the organic layer contains the compound of the present invention.

[0062] The organic layer may further include one or more of a hole injection layer, a hole transport layer, a light-emitting auxiliary layer, a hole blocking layer, an electron transport layer, and an electron injection layer, but is not limited thereto.

[0063] The light-emitting device of the present invention can be fluorescent emission, phosphorescent emission, or a combination of them. The light-emitting device can be a single light-emitting device or a series type of multiple light-emitting units.

[0064] As a simple light-emitting device, the following can be cited, but are not limited thereto.

[0065] (1) Hole transport layer / fluorescent light-emitting layer / electron transport layer;

[0066] (2) Hole transport layer / phosphorescent light-emitting layer / electron transport layer;

[0067] (3) Hole transport layer / first fluorescent light-emitting layer / second fluorescent light-emitting layer / electron transport layer;

[0068] (4) Hole transport layer / first phosphorescent light-emitting layer / second phosphorescent light-emitting layer / electron transport layer;

[0069] (5) Hole transport layer / fluorescent light-emitting layer / spacer layer / phosphorescent light-emitting layer / electron transport layer;

[0070] (6) Hole transport layer / light-emitting auxiliary layer / fluorescent light-emitting layer / electron transport layer;

[0071] (7) Hole transport layer / light-emitting auxiliary layer / fluorescent light-emitting layer / hole blocking layer / electron transport layer;

[0072] (8) Hole transport layer / light-emitting auxiliary layer / phosphorescent light-emitting layer / electron transport layer;

[0073] (9) Hole transport layer / light-emitting auxiliary layer / phosphorescent light-emitting layer / hole blocking layer / electron transport layer;

[0074] (10) Hole injection layer / hole transport layer / phosphorescent light-emitting layer / electron transport layer / electron injection layer;

[0075] (11) Hole injection layer / hole transport layer / fluorescent light-emitting layer / electron transport layer / electron injection layer;

[0076] (12) Hole injection layer / hole transport layer / light-emitting auxiliary layer / phosphorescent light-emitting layer / electron transport layer / electron injection layer;

[0078] (13) Hole injection layer / hole transport layer / luminescence assisting layer / fluorescent luminescence layer / electron transport layer / electron injection layer;

[0079] Each of the above phosphorescent / fluorescent luminescence layers can emit light of different colors.

[0080] As a tandem organic electroluminescent element, it can be an anode / first light-emitting unit / intermediate layer / second light-emitting unit / cathode. The intermediate layer is generally also called a charge generation layer, an electron extraction layer, a linking layer, etc. For example, when stacking a fluorescent luminescence layer and a phosphorescent luminescence layer, in order to prevent excitons generated in the phosphorescent luminescence layer from diffusing to the fluorescent luminescence layer or to adjust the balance of carriers, an intermediate layer is placed between the fluorescent luminescence layer and the phosphorescent luminescence layer.

[0081] When the organic light-emitting element includes a plurality of organic material layers, the organic material layers can be formed of the same material or different materials.

[0082] The organic electroluminescent element of the present specification can be manufactured by materials and methods known in the art, except that one or more of the organic material layers are formed by using the compound of formula (1).

[0083] As an anode material, a material having a relatively large work function can be used, and a transparent conductive oxide, a metal, a conductive polymer, etc. can be used.

[0084] As a cathode material, a material having a low work function is usually used to facilitate electron injection into the organic material layer, and a metal, a metal oxide, a conductive polymer, etc. can be used.

[0085] The hole injection layer is a layer that injects holes from the electrode and has the ability to transport holes. In order to reduce the energy level difference between the electrodes, the hole injection layer is mainly prepared based on aromatic amine compounds, and other materials having hole transport ability can also be used.

[0086] The hole transport layer is a layer that receives holes from the hole injection layer and transports the holes to the light-emitting layer, and a pyrrole derivative is a material having a high hole mobility that can appropriately receive holes from the anode or the hole injection layer and transfer the holes to the light-emitting layer.

[0087] The luminescence assisting layer is a layer that blocks electrons from reaching the anode, can adjust the energy level difference between the hole transport region and the light-emitting layer, facilitates holes to enter the light-emitting layer, and at the same time reduces the probability of electrons entering the hole transport region from the light-emitting layer. Commonly used ones are aromatic amine derivatives.

[0088] A light-emitting material is a material that can receive holes and electrons from a hole transport layer and an electron transport layer respectively, and combine the holes and electrons to emit light in the visible light region. The light-emitting layer material includes a host material and a doping material. Red, green, or blue light-emitting materials can be used, and if necessary, two or more light-emitting materials can be mixed. As the light-emitting material, a fluorescent material can be used, or a phosphorescent material can also be used. As the light-emitting material, a single-component material can be adopted, or a multi-component material can also be adopted.

[0089] An electron transport layer is a layer that receives electrons from an electron injection layer and transports the electrons to the light-emitting layer, and the electron transport material is a material with a high electron mobility that can receive electrons from the cathode and transfer the electrons to the light-emitting layer. Metal complexes such as triazine derivatives, oxadiazole derivatives, benzoquinone and its derivatives, naphthoquinone and its derivatives, anthraquinone and its derivatives, fluorenone derivatives, diphenyldicyanoethylene and its derivatives, 8-hydroxyquinoline and its derivatives, etc. can be used, and polymer materials and small molecule materials can also be used.

[0090] An electron injection layer is a layer that injects electrons from an electrode.

[0091] According to the materials used, the organic light-emitting device of this specification can be a top-emitting device, a bottom-emitting device, or a dual-emission type device.

[0092] In a specific embodiment of the present invention, the pyrrole derivative is selected from any one of the following compounds numbered 1-327:

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117] Synthesis general formula: The following general formula is only one synthesis method of the compounds of the present invention, and the compounds of the present invention can also be synthesized by other methods.

[0118]

[0119] wherein X represents a halogen. For different substitution positions, the same synthesis method can be adopted. L 1 -L 4 Ar 1 Ar 2 R 1 -R 4 have the same meanings as those represented in Claim 1.

[0120] Examples of compound preparation

[0121] The present invention will be specifically described through Examples 1-4.

[0122] Example 1: Preparation of Compound 115

[0123] (1) Preparation of Intermediate 115-1

[0124]

[0125] Under a nitrogen atmosphere, compound A (30.0 g, 174.39 mmol), compound B (30.0 g, 192.31 mmol), tetrakis(triphenylphosphine)palladium (4.0 g, 3.49 mmol), and potassium carbonate (48.0 g, 348.78 mmol) were added to a 1000 mL four-necked flask. 300 mL of THF and 100 mL of water were added, and the mixture was heated to reflux and stirred for 8 h. After the reaction was completed, the mixture was extracted and separated with dichloromethane and water. The organic phase was dried by rotary evaporation and purified by column chromatography (n-hexane:dichloromethane volume ratio = 25:1) to obtain intermediate 115-1 (26.6 g, yield 75%).

[0126] LC-MS (APCI): 204.13 (M+H) + 。

[0127] (2) Preparation of Intermediate 115-2

[0128]

[0129] Under a nitrogen atmosphere, intermediate 115-1 (20.0 g, 98.18 mmol), compound C (35.0 g, 196.40 mmol), palladium dichloride (1.7 g, 9.59 mmol), copper(I) chloride (38.9 g, 392.91 mmol), and sodium carbonate (10.4 g, 98.11 mmol) were added to a 1000 mL four-necked flask. 500 mL of 1,4-dioxane was added, and the mixture was stirred at room temperature for 72 h. After the reaction was completed, the mixture was extracted and separated with DCM and water. The organic phase was dried by rotary evaporation and purified by column chromatography (n-hexane:dichloromethane volume ratio = 25:1) to obtain 24.0 g of the crude product. The crude product was desolvated and crystallized with 250 mL of toluene to obtain intermediate 115-2 (15.8 g, yield 29%).

[0130] LC-MS (APCI): 558.42 (M+H) + 。

[0131] (3) Synthesis of Compound 115

[0132]

[0133] Under a nitrogen atmosphere, intermediate 115-2 (4.8 g, 8.59 mmol), compound D (3.6 g, 8.55 mmol), sodium tert-butoxide (1.6 g, 16.67 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.2 g, 0.22 mmol), and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (0.4 g, 0.98 mmol) were added to a 250 mL four-necked flask. 100 mL of toluene was added, and the reaction system was heated to reflux, followed by stirring at a constant temperature for 4 h. After the reaction was completed, heating was stopped, and flash column chromatography was performed to obtain white solid compound 115 (6.3 g, yield 78%).

[0134] LC-MS (APCI): 943.72 (M+H) + 。

[0135] 1 H NMR (400 MHz, Methylene Chloride-d2) δ 7.96 (ddd, 2H), 7.86–7.82 (m, 2H), 7.78 (dt, 2H), 7.48–7.41 (m, 5H), 7.40–7.35 (m, 7H), 7.32 (ddd, 1H), 7.24–7.20 (m, 4H), 7.17–7.08 (m, 6H), 7.08–7.03 (m, 6H), 7.02–7.00 (m, 6H), 6.95–6.91 (m, 4H), 6.91–6.87 (m, 4H), 6.79 (ddd, 1H).

[0136] Glass transition temperature Tg: 155 °C.

[0137] Example 2: Preparation of Compound 128

[0138] (1) Preparation of Intermediate 128-1

[0139]

[0140] Under a nitrogen atmosphere, compound E (10.0 g, 26.95 mmol), compound F (7.2 g, 26.97 mmol), sodium tert-butoxide (5.2 g, 54.17 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (1.1 g, 1.90 mmol), and tris(dibenzylideneacetone)dipalladium(0) (0.5 g, 0.55 mmol) were added to a four-necked reaction flask. 100 mL of toluene was added, and the temperature was raised to 110 °C. After reacting for 2 h, extraction and liquid separation were performed at room temperature, and purification by column chromatography (n-hexane:dichloromethane volume ratio = 5:1) gave intermediate 128-1 (10.0 g, yield 66%).

[0141] LC-MS (APCI): 558.49 (M+H) + .

[0142] (2) Preparation of Compound 128

[0143]

[0144] Under a nitrogen atmosphere, intermediate 128-1 (10.0 g, 17.92 mmol), compound G (5.7 g, 17.76 mmol), sodium tert-butoxide (3.4 g, 35.42 mmol), 4,5-bis(diphenylphosphine)-9,9-dimethyloxanthene (0.7 g, 1.21 mmol), tris(dibenzylideneacetone)dipalladium (0.3 g, 0.33 mmol) were added to a four-necked reaction flask, 100 mL of toluene was added, the temperature was raised to 110°C, and after reacting for 2 h, the liquid was extracted and separated at room temperature, and the crude product was purified by column chromatography (n-hexane: dichloromethane volume ratio = 5:1), and solid compound 128 (7.0 g, yield 47%) was obtained by slurrying with ethyl acetate.

[0145] LC-MS (APCI): 843.70 (M+H) + .

[0146] 1 H NMR(400MHz,Methylene Chloride-d2)δ7.61–7.56(m,4H),7.51–7.47(m,4H),7.46–7.40(m,4H),7.34–7.29(m,4H),7. 16–7.11(m,6H),7.09–7.05(m,6H),7.04–7.01(m,2H),6.99–6.90(m,10H),6.76–6.69(m,6H).

[0147] Glass transition temperature Tg: 136℃.

[0148] Example 3: Preparation of Compound 153

[0149]

[0150] Under a nitrogen atmosphere, intermediate 128-1 (5.0 g, 8.96 mmol), compound H (3.8 g, 8.96 mmol), sodium tert-butoxide (1.7 g, 17.71 mmol), tri-tert-butyl phosphine (0.18 g, 0.89 mmol), tri(dibenzylideneacetone)dipalladium (0.17 g, 0.19 mmol) were added to 40 mL of toluene solution, and the mixture was reacted at 110 ° C for 4 h. Then, compound 153 (7.0 g, yield 83%) was obtained by column chromatography (n-hexane: dichloromethane volume ratio = 1:2).

[0151] LC-MS (APCI): 943.61 (M+H) + .

[0152] 1 H NMR(400MHz,Methylene Chloride-d2)δ7.96–7.91(m,2H),7.87–7.74(m,5H),7.59(dd,1H),7.51–7.28( m,11H),7.26–7.21(m,2H),7.17–7.03(m,6H),6.98–6.82(m,17H),6.66(dq,6H).

[0153] Glass transition temperature Tg: 136℃.

[0154] Example 4: Preparation of Compound 229

[0155] (1) Preparation of Intermediate 229-1

[0156]

[0157] Under nitrogen atmosphere, compound I (4.9 g, 17.50 mmol), 2,3,4,5-tetraphenyl-1H-pyrrole (7.8 g, 21.00 mmol), tris(dibenzylideneacetone)dipalladium (1.6 g, 1.75 mmol), tri-tert-butylphosphine (1.1 g, 5.05 mmol) and sodium bis(trimethylsilyl)amide (6.4 g, 34.97 mmol) were added to a 500 mL four-necked bottle, 300 mL of xylene was added and stirred at room temperature for 36 h. After the reaction was complete, the liquid was extracted with dichloromethane and water, and the organic phase was subjected to column chromatography (n-hexane: dichloromethane volume ratio = 25:1) to obtain intermediate 229-1 (6.5 g, yield 71%).

[0158] LC-MS (APCI): 526.38 (M+H) + .

[0159] (2) Preparation of Compound 229

[0160]

[0161] Under a nitrogen atmosphere, intermediate 229-1 (6.5 g, 12.36 mmol), compound G (4.0 g, 12.46 mmol), sodium tert-butoxide (2.3 g, 23.96 mmol) and tris(dibenzylideneacetone)dipalladium(0) (0.3 g, 0.33 mmol), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (0.5 g, 1.22 mmol) were added into a 250 mL four-necked flask. 80 mL of toluene was added, and the reaction system was heated to reflux, and then stirred at a constant temperature for 4 h. After the reaction was completed, heating was stopped, and the product was purified by flash column chromatography to obtain 7.7 g of yellowish-white solid compound 229 (yield 81%).

[0162] LC-MS (APCI): 767.59 (M+H) + 。

[0163] 1 H NMR (400 MHz, Methylene Chloride-d2) δ 7.53–7.44 (m, 4H), 7.41–7.29 (m, 8H), 7.28–7.20 (m, 2H), 7.18–7.10 (m, 6H), 7.10–7.05 (m, 1H), 7.03–6.95 (m, 7H), 6.94–6.88 (m, 4H), 6.85–6.82 (m, 4H), 6.81 (d, 2H), 6.80–6.75 (m, 3H), 6.58 (ddd, 1H).

[0164] Glass transition temperature Tg: 130 °C.

[0165] Device Preparation Example

[0166] Through Application Example 1, the application effect of the compound of the present invention as a light-emitting auxiliary layer in a device is illustrated.

[0167] Application Example 1

[0168] This example provides an organic electroluminescent element, as Figure 1 shown, comprising a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, a light-emitting auxiliary layer 5, a light-emitting layer 6, a hole blocking layer 7, an electron transport layer 8 and a cathode 9 stacked from bottom to top. The hole injection layer 3, the hole transport layer 4, and the light-emitting auxiliary layer 5 are hole transport regions, and the hole blocking layer 7 and the electron transport layer 8 are electron transport regions.

[0169] The specific device structure is as follows:

[0170] ITO / HT1-PD3% (10 nm) / HT1 (60 nm) / HT2 (5 nm) / BH-BD3% (20 nm) /

[0171] HB (5 nm) / ET-LiQ 50% (30 nm) / Mg:Ag 1:9 (100 nm)

[0172] Device fabrication process:

[0173] The bottom-emitting glass substrate 1 used in this example was purchased from Guangdong Trulyst Optoelectronics Co., Ltd., and ITO was used as the anode 2. First, the bottom-emitting glass substrate was cleaned successively with ITO cleaning agent, deionized water, and isopropanol, and then baked at 180 °C for 30 minutes to dry it.

[0174] Then, the bottom-emitting glass substrate was placed into the evaporation chamber, and each organic layer was deposited on the ITO anode successively by thermal vacuum evaporation at a rate of 0.2 - 2 Å / s under a vacuum of about 10 -8 Torr. Among them, 3% of PD was doped in HT1 to form a hole injection layer 3 with a thickness of 10 nm, HT1 was formed to a thickness of 60 nm as the first hole transport layer 4, HT2 with a thickness of 5 nm was evaporated on HT1 as the light-emitting auxiliary layer 5, 3% of BD was doped in the anthracene host BH to form a blue light-emitting layer 6 with a thickness of 20 nm, HB was formed to a thickness of 5 nm as the hole blocking layer 7, ET doped with 50% Liq was formed to a thickness of 30 nm as the electron transport layer 8, and Mg:Ag (1:9) was formed to a thickness of 100 nm as the cathode 9. In this device example, the same layers were co-evaporated with different materials and existed in the layer in a certain volume ratio. For example, 50% of Liq means a volume ratio of ET 50% and Liq 50%. Finally, the device was transferred back to the glove box and encapsulated with a glass cover and a desiccant to complete the device, denoted as Comparative Example 1.

[0175] The above abbreviated compounds are specifically:

[0176]

[0177] IVL test instrument: F STAR Optical Measurement Systems, model: FS-2000GA4; in the atmospheric environment, at room temperature, the current efficiency was measured at a current density of 15 mA / cm 2 The current efficiency of the above Comparative Example 1 was 4.78 cd / A.

[0178] The light-emitting auxiliary layer 5 was prepared by replacing HT2 with compound 115, and an organic electroluminescent device was fabricated using the same method as the above Comparative Example 1, denoted as Example 1, and the current efficiency was 6.04 cd / A.

[0179] The light-emitting auxiliary layer 5 was prepared by replacing HT2 with compound 128, and an organic electroluminescent device was fabricated using the same method as in Comparative Example 1 described above, denoted as Example 2, with a current efficiency of 5.40 cd / A.

[0180] The light-emitting auxiliary layer 5 was prepared by replacing HT2 with compound 153, and an organic electroluminescent device was fabricated using the same method as in Comparative Example 1 described above, denoted as Example 3, with a current efficiency of 5.70 cd / A.

[0181] The light-emitting auxiliary layer 5 was prepared by replacing HT2 with compound 229, and an organic electroluminescent device was fabricated using the same method as in Comparative Example 1 described above, denoted as Example 4, with a current efficiency of 5.91 cd / A.

[0182] It can be seen from the above test results that applying the pyrrole derivative of the present invention in the light-emitting auxiliary layer can significantly improve the light-emitting efficiency.

[0183] The glass transition temperature of the compound of the present invention is much higher than that of HT2 (95 °C). The relatively high glass transition temperature of the compound of the present invention is conducive to forming a pinhole-free film during vacuum evaporation, which is beneficial to improving the device performance.

[0184] The above has introduced in detail a compound provided by the present invention and its application as an organic electroluminescent material. Specific examples are used herein to illustrate the principle and implementation manner of the present invention. The description of the above examples is only for helping to understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A pyrrole derivative, characterized in that The compound has the structure shown in formula (1): wherein, L 1 -L 4 each independently selected from a single bond, a substituted or unsubstituted C6-C60 arylene group, a substituted or unsubstituted C3-C60 heteroarylene group Ar 1 -Ar 2 Each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 heterocycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, R 1 -R 4 Each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 heterocycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, When the "substituted or unsubstituted" is substituted, the substituents are each independently selected from one or a combination of deuterium, halogen, cyano, C1-C10 alkyl, C3-C10 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl, and the heteroatoms of the heteroaryl are selected from one or more of O, S, N, and P.

2. The pyrrole derivative according to claim 1, wherein: Said R 1 -R 4 are each independently selected from phenyl; -L 1 -Ar 1 , -L 2 -Ar 2 are the same or different.

3. The compound according to claim 1, wherein: The said L 1 -L 4 Each independently selected from a single bond, a substituted or unsubstituted phenylene, a substituted or unsubstituted biphenylene, a substituted or unsubstituted naphthylene, a substituted or unsubstituted anthrylene, a substituted or unsubstituted phenanthrylene, a substituted or unsubstituted ylene, a substituted or unsubstituted 9,9-dimethylfluorenylene, a substituted or unsubstituted 9,9-diphenylfluorenylene, a substituted or unsubstituted spirobifluorenylene, a substituted or unsubstituted dibenzofuranylene, a substituted or unsubstituted dibenzothiophenylene.

4. The compound according to claim 1, wherein: -L 3 -L 4 - selected from the following substituted or unsubstituted groups: Represents the connection site.

5. The pyrrole derivative according to claim 1, wherein: The Ar 1 and Ar 2 are each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenylnaphthyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted fluoranthenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted perylenyl, substituted or unsubstituted triphenylenyl, substituted or unsubstituted yl, substituted or unsubstituted 9,9-dimethylfluorenyl, substituted or unsubstituted 9,9-diphenylfluorenyl, substituted or unsubstituted spirobifluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted carbazolyl.

6. The compound according to claim 1, characterized in that: -L 1 -Ar 1 -L 2 -Ar 2 Each is independently selected from hydrogen and the following substituted or unsubstituted groups: Indicates the attachment site.

7. The pyrrole derivative according to claim 1, characterized in that The compound is selected from any one of the following compounds numbered 1-327:

8. Use of the pyrrole derivative according to any one of claims 1-7 as an organic electroluminescent material.

9. An organic electroluminescent element, characterized in that, The organic electroluminescent element includes: A cathode, an anode, and one or more organic material layers disposed between the cathode and the anode and including a light-emitting layer, Wherein one or more of the organic material layers contain the pyrrole derivative according to any one of claims 1-7.

10. An electronic device, comprising: One or several of a display, a monitor, and a lighting device, including the organic electroluminescent element according to claim 9; And a control unit for driving the above display device.

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