A fluorene derivative and its application

Abstract

The present invention relates to the technical field of organic electroluminescent materials, and in particular to a fluorene derivative and its application. The structural formula of the fluorene derivative is shown in formula (I); the compound shown in formula (I) provided by the present invention has the structure of fluorene. The compound is used in an organic electroluminescent element to significantly reduce the driving voltage, improve the luminous efficiency and lifespan;

Description

Technical Field

[0001] The invention relates to the technical field of organic electroluminescent materials, and in particular to a fluorene derivative and application thereof in an organic light-emitting element. Background Art

[0002] Generally speaking, organic luminescence refers to the phenomenon of light emission when electrical energy is applied to an organic substance; that is, when an organic layer is arranged between an anode and a cathode, if a voltage is applied between the two electrodes, holes are injected from the anode into the organic layer, and electrons are injected from the cathode into the organic layer; when the injected holes and electrons meet, excitons are formed, and when the excitons transition to the ground state, light and heat are emitted.

[0003] In recent years, organic electroluminescent display technology has become mature, and some products have entered the market, but there are still many problems to be solved in the process of industrialization. In particular, there are many problems that have not been solved in the various organic materials used to make components, such as carrier injection and transmission performance, material electroluminescent performance, service life, color purity, matching between various materials and between electrodes, etc.; in particular, the luminous efficiency and service life of the light-emitting components have not met the practical requirements, which greatly limits the development of OLED technology. The metal complex phosphorescent materials that use triplet luminescence have high luminous efficiency, and their green and red light materials have met the use requirements, but the metal complex phosphorescent materials require phosphorescent materials or hole materials with high triplet energy levels to match them. Therefore, the development of phosphorescent materials or hole materials with high triplet energy levels is an urgent need for the current development of OLED.

[0004] Under the current technological development, both fluorescent materials and phosphorescent materials need to be improved, especially in terms of operating voltage, efficiency and life span used in organic electroluminescent elements and thermal stability during sublimation.

[0005] Therefore, in order to overcome the above-mentioned technical problems and further improve the characteristics of organic electroluminescent elements, there continues to be a demand for the development of more stable and effective substances that can be used as phosphorescent materials or hole materials in organic electroluminescent elements.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The object of the present invention is to provide a fluorene derivative, which can improve the thermal stability of the material and the ability to transport carriers. The organic electroluminescent element prepared using the fluorene derivative can significantly reduce the driving voltage, improve the luminous efficiency and life; another object of the present invention is to provide an application of the compound.

[0008] Specifically, the present invention provides the following technical solutions:

[0009] The present invention provides a fluorene derivative, the structural formula of which is shown in formula (I):

[0010]

[0011] in,

[0012] L 1 Selected from single bonds, substituted or unsubstituted C6-C 60 Arylene, or substituted or unsubstituted C2-C 60 The group consisting of heteroarylene;

[0013] R 1 , R 2 are each independently selected from hydrogen, substituted or unsubstituted C1-C 40 Alkyl, substituted or unsubstituted C2-C 40 Alkenyl, substituted or unsubstituted C3-C 40 Cycloalkyl, substituted or unsubstituted C3-C 40 Cycloalkenyl, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C2-C 60 Heteroaryl, or R 1 and R 2 The ring is closed to form the following groups represented by formula A1 to A7:

[0014]

[0015] And R 1 and R 2 At most one of them can be selected from substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C2-C 60 heteroaryl;

[0016] R 3 selected from hydrogen, deuterium, fluorine, hydroxyl, nitrile, nitro, carboxyl or its carboxylate, sulfonic acid or its sulfonate, phosphate or its phosphate, substituted or unsubstituted C1-C 40 Alkyl, substituted or unsubstituted C1-C 40 Alkoxy, substituted or unsubstituted C2-C 40 Alkenyl, substituted or unsubstituted C1-C 40 Alkylthio, substituted or unsubstituted C1-C 40 Alkoxy, substituted or unsubstituted C3-C 40 Cycloalkyl, substituted or unsubstituted C1-C 40 Alkylsulfoxide, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C6-C 60 Aryloxy, substituted or unsubstituted C6-C60 Arylthio, substituted or unsubstituted C3-C 40 Silyl, or substituted or unsubstituted C2-C 60 The group consisting of heterocyclic aromatic groups; R 3 for one or more;

[0017] Ar 1 ,Ar 2 Each is independently selected from substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C6-C 60 Condensed ring aromatic group, substituted or unsubstituted C6-C 60 Arylamine, or substituted or unsubstituted C2-C 60 The group consisting of heterocyclic aromatic groups; wherein Ar 1 ,Ar 2 , L 1 They may be arbitrarily joined or cyclized to form substituted or unsubstituted rings, and the formed rings may or may not contain heteroatoms O, S, N or Si;

[0018] Represents R 1 or R 2 connection key.

[0019] In the present invention, in the substituted or unsubstituted ring formed by the combination of adjacent groups, "ring" refers to a substituted or unsubstituted hydrocarbon ring, or a substituted or unsubstituted heterocycle. Condensed ring refers to a condensed aliphatic ring, a condensed aromatic ring, a condensed aliphatic heterocycle, a condensed aromatic heterocycle, or a combination thereof.

[0020] The fluorene derivative according to the present invention is represented by the above chemical formula (I), wherein the fluorene derivative containing alkene and the fluorene derivative containing heteroaryl group L 1 NAr 1 Ar 2 The compound represented by formula (I) of the present invention is not only electrochemically stable and excellent in hole mobility, but also has a high glass transition temperature and excellent thermal stability, compared to the conventionally known structures B-1 to B-4.

[0021]

[0022] Therefore, the fluorene derivative of the present invention has excellent hole transport ability and luminescent properties, and can be used as a material for any of the hole injection layer, hole transport layer, luminescent layer and electron blocking layer of the organic layer of the organic electroluminescent element. It is preferably used as a material for any of the luminescent layer and the electron blocking layer, and more preferably used as a material for the electron blocking layer.

[0023] Specifically, the compound shown in the formula (I) of the present invention is by comprising the fluorene derivative of alkene and triarylamine, thus compared with the alkene containing two aryl groups with strong electron-donating group ability, such as B-1 to B-4, there is stronger hole transport ability and electron blocking ability, can show relatively high luminous efficiency and high glass transition temperature. Thus, when the fluorene derivative shown in the formula (I) of the present invention is used for organic electroluminescent element, not only can excellent thermal stability and carrier transport ability, especially electron blocking ability and luminous ability be expected, but also the driving voltage of the element can be reduced, efficiency and lifespan can be improved, and as the latest electron blocking layer material, the excellent efficiency rise caused by the triplet-triplet fusion effect can be shown due to the high triplet energy level.

[0024] In addition, the fluorene derivative represented by the formula (I) of the present invention is obtained by 1 , R 2 and the substituent R 3 By introducing a substituent, the HOMO and LUMO energy levels can be adjusted according to the type of the substituent, thereby having a wide band gap. In an organic electroluminescent device using such a compound, high hole-transporting properties and electron-blocking properties can be exhibited most effectively.

[0025] In addition, the fluorene derivative represented by the formula (I) of the present invention is modified by introducing various substituents L into the above basic skeleton. 1 and Ar 1 ,Ar 2 , especially aryl and / or heteroaryl groups, the molecular weight of the compound is significantly increased, thereby increasing the glass transition temperature, thereby having higher thermal stability than previous luminescent materials. Therefore, the performance and life characteristics of the organic electroluminescent element containing the compound according to the present invention can be greatly improved. The organic electroluminescent element with improved performance and life characteristics can ultimately maximize the performance of the full-color organic light-emitting panel.

[0026] The fluorene derivative represented by formula (I) of the present invention comprises R 1 and R 2 In this case, preferably, the fluorene derivative is selected from the group consisting of the following structures:

[0027]

[0028] Wherein, n and m are each independently selected from integers from 0 to 40;

[0029] p and q are each independently selected from integers from 1 to 40;

[0030] R 4 , R 5Each is independently selected from the group consisting of hydrogen, deuterium, fluorine, nitrile, methyl, tert-butyl, phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, triphenylene, carbazolyl, fluorenyl, dibenzofuran or dibenzothiophene.

[0031] Preferably, the R 3 , R 4 , R 5 Each is independently hydrogen, tert-butyl or phenyl.

[0032] Preferably, n and m are each independently selected from integers from 0 to 10.

[0033] Preferably, p and q are each independently selected from integers of 1 to 5.

[0034] Preferably, the aryl, heteroaryl or heterocyclic aryl is selected from phenyl, naphthyl, anthracenyl, benzanthryl, phenanthrenyl, pyrenyl, yl, peryl, fluoranthene, tetraphenyl, pentacene, benzopyrenyl, biphenyl, phenylene, terphenyl, triphenyl, quadriphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthryl, triphenylene, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indenofluorenyl, cis- or trans-indenocarbazolyl, indolecarbazolyl, benzofuranocarbazolyl, benzothiophenocarbazolyl, benzocarbazolyl, dibenzocarbazolyl, azadibenzo[g,iD]naphtho[2,1,8-cde]azulene, trimerized indenyl, isotrimerized indenyl, spirotrimerized indenyl, spiroisotrimerized indenyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, pyrrolyl, indolyl, isoindolyl, carbazolyl, pyridinyl, quinolyl, isoquinolyl, acridinyl, phenanthridinyl, benzo[5,6]quinolyl, benzo[6,7]quinolyl, benzo[7,8]quinolyl, phenothiazinyl, phenoxazinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthoimidazolyl, phenanthroimidazolyl, pyridoimidazolyl, pyrazinoimidazolyl, quinoxalinoimidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthrazolyl, phenanthroxazolyl, isoxazolyl, 1,2- Thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, hexaazatriphenylene radical, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthryl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenoxazinyl, phenothiazinyl, fluorescein ring radical, naphthyridinyl, azacarbazolyl, benzocarbolinyl, carbolinyl, phenanthrolinyl, 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1 ,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purinyl, pteridinyl, indolizinyl, quinazolinyl, benzothiadiazolyl or a group derived from a combination of these systems.

[0035] Furthermore, the Ar 1 ,Ar 2Each is independently selected from the group consisting of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted triphenylene, substituted or unsubstituted carbazolyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted dibenzofuranyl, or substituted or unsubstituted dibenzothiophene.

[0036] In the fluorene derivative represented by formula (I) of the present invention, L 1 In order to combine the above-mentioned olefin-containing fluorene derivative with the above-mentioned NAr 1 Ar 2 The functional group connected, at this time, preferably, the L 1 Selected from a single bond or the group consisting of the following groups shown in III-1 to III-23:

[0037]

[0038] The dotted line represents the connection site of the group. In this case, the binding position of the group shown in the above formulas III-1 to III-23 is not limited and can be ortho, meta, or para. 1 can be independently selected from deuterium, halogen atoms, nitrile groups, C1-C 40 Alkyl, C6-C 60 Aryl and C2-C 60 In the group consisting of heterocyclic aromatic groups, one or more substituents are substituted. In this case, when there are multiple substituents, the multiple substituents are preferably the same as or different from each other.

[0039] In the present invention, the term "substituted or unsubstituted" means a group selected from hydrogen, deuterium, a halogen atom, a hydroxyl group, a nitrile group, a nitro group, an amino group, an amidine group, a hydrazine group, a hydrazone group, a carboxyl group or a carboxylate thereof, a sulfonic acid group or a sulfonate thereof, a phosphoric acid group or a phosphate thereof, a C1-C 40 Alkyl, C2-C 40 Alkenyl, C2-C 40 Alkynyl, C1-C 40 Alkoxy, C3-C 40 Cycloalkyl, C3-C 40 Cycloalkenyl, C6-C 60 Aryl, C6-C 60 Aryloxy, C6-C 60 Aryl sulfide group and C2-C 60 The heterocyclic aryl group may be substituted or unsubstituted with one or more substituents, or may be substituted or unsubstituted with a substituent in which two or more substituents among the substituents exemplified above are linked together.

[0040] The aryl group in the sense of the present invention contains 6 to 60 carbon atoms, and the heteroaryl group contains 2 to 60 carbon atoms and at least one heteroatom, provided that the total number of carbon atoms and heteroatoms is at least 5; the heteroatom is preferably selected from N, O or S. In this case, the two or more rings of the heteroaryl group may be attached to each other simply or in a condensed form, and further, may also include a condensed form with the aryl group. As non-limiting examples of such heteroaryl groups, there can be mentioned six-membered monocyclic rings such as pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl; polycyclic rings such as phenoxathiyl, indolizinyl, indolyl, purinyl, quinolyl, benzothiazolyl, carbazolyl; and 2-furanyl, N-imidazolyl, 2-isoxazolyl, 2-pyridinyl, 2-pyrimidinyl, etc.

[0041] Alkyl in the sense of the present invention is a straight-chain or branched alkyl radical containing 1 to 40 carbon atoms, in which individual hydrogen atoms or -CH2- groups may also be substituted; an alkenyl or alkynyl radical containing at least two carbon atoms, and, by way of non-limiting example, an alkyl, alkenyl or alkynyl radical is preferably taken to mean the following radicals: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, neopentyl, cyclopentyl, n-hexyl, neohexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl.

[0042] Alkoxy is preferably taken to mean alkoxy having 1 to 40 carbon atoms, methoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, sec-pentoxy, 2-methylbutoxy, n-hexyloxy, cyclohexyloxy, n-heptyloxy, cycloheptyloxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy and 2,2,2-trifluoroethoxy.

[0043] The heteroalkyl group is preferably an alkyl group having 1 to 40 carbon atoms and refers to a group in which a single hydrogen atom or a -CH2- group is replaced by an oxygen, sulfur or halogen atom, and as non-limiting examples, alkoxy, alkylthio, fluorinated alkoxy, fluorinated alkylthio, in particular methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio, tert-butylthio, trifluoromethylthio 4-fluoro-1,4-difluoro-2,4-difluoro-3,4-difluoro-4,4-difluoro-5,4-difluoro-6,4-difluoro-7,4-difluoro-8,4-difluoro-9,4-difluoro-10,4-difluoro-11,4-difluoro-12,4-difluoro-13,4-difluoro-14,4-difluoro-15,4-difluoro-26,4-difluoro-16,4-difluoro-17,4-difluoro-28,4-difluoro-18,4-difluoro-29,4-difluoro-30,4-difluoro-31,4-difluoro-32,4-difluoro-33,4-difluoro-34,4-difluoro-35,4-difluoro-36,4-difluoro-37,4-difluoro-38,4-difluoro-39,4-difluoro-40,4-difluoro-41,4-difluoro-42,4-difluoro-54,4-difluoro-39

[0044] Generally speaking, the cycloalkyl and cycloalkenyl groups according to the present invention can be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptyl, cycloheptenyl, wherein one or more -CH2- groups can be replaced by the above groups; in addition, one or more hydrogen atoms can also be replaced by deuterium atoms, halogen atoms or nitrile groups.

[0045] The heterocycloalkyl group used in the present invention refers to a monovalent functional group obtained by removing one hydrogen atom from a non-aromatic hydrocarbon having an atomic nucleus number of 3 to 40. In this case, one or more carbon atoms, preferably 1 to 3 carbon atoms in the ring are substituted by heteroatoms such as N, O or S. Non-limiting examples thereof include tetrahydrofuran, tetrahydrothiophene, morpholine, piperazine and the like.

[0046] The condensed ring aromatic group used in the present invention refers to a monovalent functional group obtained by removing one hydrogen atom from an aromatic hydrocarbon having 6 to 60 carbon atoms and combining two or more rings. In this case, the two or more rings may be attached to each other in a simple or condensed form. Non-limiting examples thereof include phenanthrenyl, anthracenyl, fluoranthenyl, pyrenyl, triphenylene, perylene, Ji et al.

[0047] The arylamine group used in the present invention refers to an amine substituted by an aryl group having 6 to 60 carbon atoms, and non-limiting examples of the arylamine group include diphenylamine, N-phenyl-1-naphthylamine, N-(1-naphthyl)-2-naphthylamine, etc. The heteroarylamine group refers to an amine substituted by an aryl group having 6 to 60 carbon atoms and a heteroaryl group having 2 to 60 carbon atoms, and non-limiting examples of the heteroarylamine group include N-phenylpyridine-3-amine, N-([1,1'-biphenyl]-4-yl)dibenzo[b,d]furan-2-amine, N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-9H-fluorene-2-amine, etc.

[0048] The alkoxy group used in the present invention refers to RO - The monovalent functional group represented by R is an alkyl group having 1 to 40 carbon atoms, which may include a straight chain, a branched chain or a ring structure. Non-limiting examples of such alkoxy groups include methoxy, ethoxy, n-propoxy, 1-propoxy, tert-butoxy, n-butoxy, pentyloxy, cyclopentyloxy, cyclohexyloxy, and the like.

[0049] The aryloxy group used in the present invention refers to R'O - The monovalent functional group represented by is an aryl group having a carbon number of 6 to 60. Non-limiting examples of such an aryloxy group include phenoxy, naphthoxy, biphenyloxy and the like.

[0050] The alkylsilyl group used in the present invention refers to a silyl group substituted by an alkyl group having 1 to 40 carbon atoms, and the number of carbon atoms constituting the alkylsilyl group is at least 3. Non-limiting examples of the alkylsilyl group include trimethylsilyl and triethylsilyl. The arylsilyl group refers to a silyl group substituted by an aryl group having 6 to 60 carbon atoms.

[0051] The arylphosphino group used in the present invention refers to a diarylphosphino group substituted with an aryl group having 6 to 60 carbon atoms, and non-limiting examples of the arylphosphino group include diphenylphosphino group, di(4-trimethylsilylphenyl)phosphino group, etc. The aryloxyphosphino group is a diarylphosphino group in which the phosphorus atom is oxidized to the highest valence state.

[0052] The aryl boryl group used in the present invention refers to a diaryl boryl group substituted by an aryl group having 6 to 60 carbon atoms, and non-limiting examples of the aryl boryl group include diphenyl boryl and di(2,4,6-trimethylphenyl)boryl. The alkyl boryl group refers to a dialkyl boryl group substituted by an alkyl group having 1 to 40 carbon atoms, and non-limiting examples of the alkyl boryl group include di-tert-butyl boryl and diisobutyl boryl.

[0053] Preferably, the fluorene derivative is selected from the compounds shown in the following formulae D475-D606:

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061] Wherein, *—T1—*, *—T2—* are each independently selected from *—O—*, *—S—* or one of the following structures:

[0062]

[0063] *— and —* represent connecting keys.

[0064] The present invention also provides a method for preparing the above-mentioned fluorene derivative, as shown in Scheme 1:

[0065] Option 1,

[0066]

[0067] In Scheme 1, the symbols used are as defined in formula (I), and X1 is Cl, Br or OTf;

[0068] The raw materials for synthesizing the compound represented by formula (I) can be purchased from commercial sources. The principle, operation process, conventional post-treatment, column purification, recrystallization purification and other means of this method are well known to synthesizers in the art and can fully realize the synthesis process to obtain the target product.

[0069] Specifically, the compound of formula (I) is composed of an iodinated benzene derivative S0 and R 1 , R 2 The substituted α-bromoacrylic acid is subjected to a decarboxylation substitution reaction to prepare intermediate S1; intermediate S1 is reacted with Ar 1 Ar 2 NL 1 Boric acid or boric acid pinacol ester is subjected to SUZUKI coupling reaction to prepare compound formula (I) or with Ar 1 Ar 2 NH undergoes Buchwald-Hartwig coupling reaction to prepare the compound of formula (I) of the present invention. Intermediate Ar 1 Ar 2 NL 1 Boric acid or boronic acid pinacol ester and Ar 1 Ar2 NH is prepared by palladium-catalyzed or base-catalyzed coupling reactions.

[0070] The palladium catalyst that can be used for the palladium-catalyzed coupling reaction can be selected from: Pd(P- t Any one of Bu3)2, Pd(PPh3)4, Pd2(dba)3, Pd2(dba)3CHCl3, PdCl2(PPh3)2, PdCl2(CH3CN)2, Pd(OAc)2, Pd(acac)2, Pd / C, PdCl2, [Pd(allyl)Cl]2, etc., or a mixture of two or more thereof.

[0071] In addition, the base used in the palladium-catalyzed coupling reaction or the base-catalyzed coupling reaction can be selected from: sodium tert-butoxide, potassium tert-butoxide, sodium hydride, lithium hydride, sodium tert-amylate, sodium ethoxide, sodium methoxide, sodium carbonate, potassium carbonate, cesium carbonate, lithium, potassium hydride, triethylamine, cesium fluoride, etc., and a mixture of one or two or more thereof.

[0072] The coupling reaction can be carried out in an organic solvent, wherein the organic solvent can be selected from: ether, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, ethylene glycol ethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ether, diethylene glycol diethyl ether, or ether solvents such as anisole, benzene, toluene, xylene and other aromatic hydrocarbon agents, chlorobenzene, dichlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, cyclopentane, etc., and one or a mixture of two or more can be used.

[0073] The present invention also provides an organic electroluminescent material, the raw material of which includes the fluorene derivatives mentioned above; the organic electroluminescent material including the fluorene derivatives of the present invention has the ability of carrier transmission.

[0074] The present invention also provides the use of the above-mentioned fluorene derivative in the preparation of an organic electroluminescent element.

[0075] The present invention also provides an organic electroluminescent element, which comprises: a first electrode, a second electrode, a capping layer and one or more organic layers disposed between the first electrode and the second electrode; the material of at least one layer of the organic layer or the capping layer comprises the above-mentioned fluorene derivative.

[0076] The organic electroluminescent element comprises a cathode, an anode and at least one luminescent layer. In addition to these layers, it may also comprise other layers, for example, in each case, one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers and / or charge generation layers. An intermediate layer having, for example, an exciton blocking function may also be introduced between two luminescent layers. However, it should be noted that each of these layers does not necessarily have to be present. The organic electroluminescent device described herein may comprise one luminescent layer, or it may comprise multiple luminescent layers. That is, a variety of luminescent compounds capable of luminescence are used in the luminescent layer. A system having three luminescent layers is particularly preferred, wherein the three layers may display blue, green and red luminescence. If there are more than one luminescent layer, then according to the present invention, at least one of these layers comprises a fluorene derivative of the present invention.

[0077] Furthermore, the organic electroluminescent element according to the present invention does not contain a separate hole injection layer and / or hole transport layer and / or hole blocking layer and / or electron transport layer, that is, the light-emitting layer is directly adjacent to the electron blocking layer or the hole transport layer or the anode, and / or the light-emitting layer is directly adjacent to the electron transport layer or the electron injection layer or the cathode.

[0078] In the other layers of the organic electroluminescent element according to the invention, in particular in the hole injection and hole transport layers and in the electron injection and electron transport layers, all materials can be used in the manner commonly used according to the prior art. A person skilled in the art will therefore be able to use all materials known about organic electroluminescent elements in combination with the emitting layer according to the invention without inventive effort.

[0079] Furthermore, preference is given to organic electroluminescent components in which one or more layers are applied by means of a sublimation process, in which the organic electroluminescent components are applied in a vacuum sublimation apparatus at temperatures below 10 -5 Pa, preferably less than 10 -6 The material is applied by vapor deposition at an initial pressure of 10 Pa. However, the initial pressure may also be even lower, for example below 10 -7 Pa.

[0080] Likewise preferred is an organic electroluminescent component in which one or more layers are applied by means of an organic vapor phase deposition method or by means of carrier gas sublimation, wherein at 10 -5 The material is applied at a pressure of between 100 Pa and 1 Pa. A particular example of this method is the organic vapor jet printing method, in which the material is applied directly through a nozzle and is thus structured.

[0081] Furthermore, preference is given to organic electroluminescent elements in which one or more layers are produced from solution, for example by spin coating, or by means of any desired printing method, for example screen printing, flexographic printing, lithography, photoinduced thermography, thermal transfer, inkjet printing or nozzle printing. Soluble compounds, for example obtained by suitable substitution. These methods are also particularly suitable for oligomers, dendrimers and polymers. Also possible are hybrid methods, in which, for example, one or more layers are applied from solution and one or more further layers are applied by vapor deposition.

[0082] These methods are generally known to those skilled in the art, and they can apply them to organic electroluminescent elements comprising the compounds according to the invention without inventive step.

[0083] The present invention therefore also relates to a method for producing an organic electroluminescent element according to the invention, applying at least one layer by means of a sublimation method and / or characterized in that at least one layer is applied by means of an organic vapor phase deposition method or by means of carrier gas sublimation and / or characterized in that at least one layer is applied from a solution by spin coating or by means of a printing method.

[0084] In addition, the present invention relates to a fluorene derivative according to the present invention comprising at least one of the above-mentioned fluorene derivatives. The same preferences as indicated above for the organic electroluminescent element apply to the compounds according to the present invention. In particular, other compounds may also be preferably included in addition to the fluorene derivatives. The treatment of the fluorene derivatives according to the present invention from the liquid phase, for example by spin coating or by a printing method, requires a preparation for the treatment of the compounds according to the present invention. These preparations may, for example, be solutions, dispersions or emulsions. For this purpose, a mixture of two or more solvents may preferably be used. Suitable and preferred solvents are, for example, toluene, anisole, o-xylene, m-xylene or p-xylene, methyl benzoate, mesitylene, tetralin, o-dimethoxybenzene, tetrahydrofuran, methyltetrahydrofuran, tetrahydropyran, chlorobenzene, dioxane, phenoxytoluene, in particular 3-phenoxytoluene, (-)-fennel, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, α-terpenes alcohol, benzothiazole, butyl benzoate, isopropylbenzene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, methyl benzoate, 1-methylpyrrolidone, p-cymene, phenethyl ether, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, or a mixture of these solvents.

[0085] Preferably, the organic layer includes a hole injection layer, a hole transport layer, a hole blocking layer, a light emitting layer, an electron transport layer, an electron injection layer or an electron blocking layer.

[0086] Furthermore, the light-emitting layer or the electron blocking layer comprises the fluorene derivative of the present invention.

[0087] Furthermore, the electron blocking layer comprises the fluorene derivative of the present invention.

[0088] The present invention also provides a consumer product, which includes the organic electroluminescent element mentioned above.

[0089] In addition, unless otherwise specified, the raw materials used in the present invention can be obtained commercially, and any range recorded in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0090] Beneficial effects achieved by the present invention:

[0091] The fluorene derivative represented by formula (I) provided by the present invention can be applied to the organic layer of an organic electroluminescent element due to its excellent hole mobility, electron blocking property, thermal stability and luminescent properties. In particular, when the fluorene derivative represented by formula (I) of the present invention is used in an electron blocking layer or a luminescent layer, an organic electroluminescent element having a lower driving voltage, higher efficiency and longer life than conventional electron blocking materials can be manufactured, and further, a full-color display panel with improved performance and life can also be manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Figure 1 A schematic diagram of an organic light-emitting device 100 is shown. The illustration is not necessarily drawn to scale. The device 100 may include a substrate 101, an anode layer 102, a hole injection layer 103, a hole transport layer 104, an electron blocking layer 105, a light-emitting layer 106, a hole blocking layer 107, an electron transport layer 108, an electron injection layer 109, a cathode layer 110, and a capping layer (CPL) 111. The device 100 may be manufactured by depositing the described layers in order.

[0093] Figure 2 Schematic diagram of an organic light-emitting device 200 showing two light-emitting layers. The device includes a substrate 201, an anode layer 202, a hole injection 203, a hole transport layer 204, a first light-emitting layer 205, an electron transport layer 206, a charge generation layer 207, a hole injection layer 208, a hole transport layer 209, a second light-emitting layer 210, an electron transport layer 211, an electron injection layer 212, and a cathode layer 213. The device 200 can be prepared by depositing the described layers in sequence. Because the most common OLED device has one light-emitting layer, and the device 200 has a first light-emitting layer and a second light-emitting layer, the light emission peaks of the first light-emitting layer and the second light-emitting layer can be overlapping, cross-overlapping, or non-overlapping. In the corresponding layers of the device 200, materials similar to those described with respect to the device 1 can be used. Figure 2 One example is provided of how some layers may be added from the structure of device 100 . DETAILED DESCRIPTION

[0094] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0095] In the description of the present invention, unless otherwise specified, “plurality” means two or more than two; the orientations or positional relationships indicated by the terms “upper”, “lower”, etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0096] The experimental methods used in the following examples are all conventional methods unless otherwise specified. The experimental raw materials and related equipment used in the following examples are all commercially available unless otherwise specified, and the percentages are all mass percentages unless otherwise specified.

[0097] The test instruments and methods for testing the performance of OLED materials and components in the following embodiments are as follows:

[0098] OLED component performance testing conditions:

[0099] Brightness and chromaticity coordinates: tested using a spectral scanner PhotoResearch PR-715;

[0100] Current density and lighting voltage: tested using Keithley 2420 digital source meter;

[0101] Power efficiency: Tested using NEWPORT 1931-C.

[0102] Example 1

[0103] The preparation method of compound D558 comprises the following steps:

[0104] Step 1: Preparation of intermediate A1

[0105]

[0106] Under nitrogen protection, 20.0 mmol of 4'-chloro-2-iodo-1,1'-biphenyl was dissolved in 50 mL of DMSO, and 26.0 mmol of 2-bromoacrylic acid derivative SM-2, 2.0 mmol of palladium acetate, 4.0 mmol of P(o-tol)3, 40.0 mmol of anhydrous potassium carbonate and 40.0 mmol of anhydrous potassium acetate were added. The temperature was raised to 110°C and stirred for reaction for 12 hours. The temperature was cooled to room temperature, and the reaction solution was poured into 250 mL of water and filtered. The filter cake was washed with water, and the solid was separated and purified by silica gel column to obtain intermediate A1 as a white solid with a yield of 58%.

[0107] The following intermediates were prepared by similar synthetic methods as described above:

[0108]

[0109]

[0110]

[0111]

[0112]

[0113] Step 2: Preparation of compound D558

[0114]

[0115] Under nitrogen protection, 12.0 mmol of intermediate A1, 10.0 mmol of diarylamine, 15.0 mmol of sodium tert-butoxide, 0.01 mmol of Pd2(dba)3 catalyst, 0.04 mmol of 10% tri-tert-butylphosphine toluene solution and 50 mL of toluene were heated to 100°C and stirred for reaction for 15 hours, cooled to room temperature, diluted with 50 mL of water, extracted with dichloromethane, the organic phase was collected, dried, filtered, the filtrate was concentrated under reduced pressure, and separated and purified by silica gel column to obtain compound D558;

[0116] T1, T2 are CMe2, white solid, yield: 78%, MS (MALDI-TOF): m / z = 698.3803 [M+H] + ; 1 HNMR (δ, CDCl3): 8.28(1H,s); 7.87~7.86(2H,m); 7.77~7.76(2H,m); 7.49~7.43(3H,m); 7.36~7.28(6H, m); 7.26~7.20(5H,m); 7.16~7.12(2H,m); 4.05(2H,s); 2.11~2.10(10H,d); 1.96(2H,s); 1.68(12H,s).

[0117] T1 is 9,9-fluorenyl, T2 is CMe2, white solid, yield: 76%, MS (MALDI-TOF): m / z=820.3951 [M+H] + ; 1 HNMR (δ, CDCl3): 8.28(1H,s); 7.87~7.85(3H,m); 7.78~7.76(3H,m); 7.52~7.42(7H,m); 7.38~7.26(8H ,m); 7.24~7.16(5H,m); 7.14~7.12(2H,m); 4.05(2H,s); 2.11~2.10(10H,d); 1.96(2H,s); 1.68(6H,s).

[0118] Referring to the above-mentioned synthesis method, the compounds shown in Table 1 below were prepared:

[0119] Table 1

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127] Example 2

[0128] Preparation of compound D597:

[0129]

[0130] Under nitrogen protection, 10.0 mmol of intermediate A32, 12.0 mmol of boric acid pinacol ester SM-3, 36.0 mmol of anhydrous potassium carbonate and 40 mL of toluene were mixed, and then 0.01 mmol of Pd132 catalyst, 20 mL of ethanol and 20 mL of water were added, and the temperature was raised to reflux and stirred for reaction for 12 hours, cooled to room temperature, and 50 mL of water was added to dilute, extracted with dichloromethane, and the organic phase was collected, dried, filtered, and the filtrate was concentrated under reduced pressure. It was separated and purified by silica gel column to obtain compound D597, T1: CMe2, white solid, yield: 78%, MS (MALDI-TOF): m / z=746.3795 [M+H] + ; 1 HNMR (δ, CDCl3): 8.29(1H,s); 8.09(1H,s); 7.90~7.88(1H,d); 7.79~7.76(1H,m); 7.74~7.68(4H,m); 7.65~7.60(2H,m); 7 .56~7.42(5H,m); 7.40~7.33(5H,m); 7.30~7.26(3H,m); 7.23~7.14(7H,m); 7.07~7.02(2H,m); 1.68(6H,s); 1.07(9H,s).

[0131] T1 is 9,9-fluorenyl, white solid, yield: 75%, MS (MALDI-TOF): m / z=868.3957 [M+H] + ; 1HNMR (δ, CDCl3): 8.28(1H,s); 8.09(1H,s); 7.90~7.81(4H,m); 7.79~7.76(1H,m); 7.74~7.68(4H,m); 7.65~7.60(2 H,m); 7.56~7.42(7H,m); 7.40~7.32(6H,m); 7.30~7.26(6H,m); 7.23~7.14(6H,m); 7.07~7.02(2H,m); 1.07(9H,s).

[0132] Referring to the above-mentioned similar synthesis method, the compounds shown in Table 2 below were prepared:

[0133] Table 2

[0134]

[0135]

[0136] Example 3

[0137] Preparation of compound D604:

[0138]

[0139] Under nitrogen protection, 12.0 mmol of intermediate A47, 10.0 mmol of diarylamine SM-4, 15.0 mmol of sodium tert-butoxide and 60 mL of toluene were mixed, and then 0.1 mmol of Pd2(dba)3 catalyst, 0.1 mmol of cuprous iodide and 0.3 mmol of 10% tri-tert-butylphosphine toluene solution were added, and the mixture was heated to 100°C and stirred for reaction for 12 hours, cooled to room temperature, diluted with 50 mL of water, extracted with dichloromethane, and the organic phase was collected, dried, filtered, and the filtrate was concentrated under reduced pressure, separated and purified by silica gel column to obtain compound D604;

[0140] T1: CMe2, white solid, yield: 84%, MS (MALDI-TOF): m / z=628.3022 [M+H] + ; 1 HNMR (δ, CDCl3): 8.27(1H,s); 7.98~7.97(1H,d); 7.90~7.88(1H,d); 7.83~7.81(2H,m); 7.72~7.69(2H,m); 7.67~7.62(4H,m ); 7.52~7.48(1H,m); 7.39~7.28(7H,m); 7.25~7.18(3H,m); 7.16~7.12(3H,m); 7.08~7.02(3H,m); 2.75(3H,s); 1.68(6H,s).

[0141] T1 is 9,9-fluorenyl, white solid, yield: 82%, MS (MALDI-TOF): m / z=750.3177 [M+H] + ; 1 HNMR (δ, CDCl3): 7.96~7.90(5H,m); 7.72~7.69(2H,m); 7.67~7.62(4H,m); 7.52~7.48(1H,m) ; 7.46~7.32(10H,m); 7.22~7.12(7H,m); 7.16~7.07(4H,m); 6.87~6.81(3H,m); 2.75(3H,s).

[0142] Referring to the above-mentioned similar synthesis method, the following compounds shown in Table 3 were prepared:

[0143] Table 3

[0144]

[0145] In the above embodiments, *—T1—* and *—T2—* are each independently selected from *—O—*, *—S—* or one of the following structures:

[0146]

[0147] *— and —* represent connecting keys.

[0148] Example 4

[0149] An OLED element, such as Figure 1 As shown, the OLED element of this embodiment is a top emission element, including a substrate 101, an anode layer 102 disposed on the substrate 101, a hole injection layer 103 disposed on the anode layer 102, a hole transport layer 104 disposed on the hole injection layer 103, an electron blocking layer 105 disposed on the hole transport layer 104, an organic light emitting layer 106 disposed on the electron blocking layer 105, a hole blocking layer 107 disposed on the organic light emitting layer 106, an electron transport layer 108 disposed on the hole blocking layer 107, an electron injection layer 109 disposed on the electron transport layer 108, a cathode 110 disposed on the electron injection layer 109, and a capping layer 111 on the cathode. The preparation method of the OLED element without the hole blocking layer 107 comprises the following steps:

[0150] 1) The glass substrate coated with the ITO conductive layer was ultrasonically treated in a cleaning agent for 30 minutes, rinsed in deionized water, ultrasonically treated in an acetone / ethanol mixed solvent for 30 minutes, baked in a clean environment until completely dry, irradiated with an ultraviolet cleaning machine for 10 minutes, and bombarded with a low-energy cation beam.

[0151] 2) Place the treated ITO glass substrate in a vacuum chamber and evacuate the chamber to a vacuum of less than 1×10 -5 Pa, and silver is evaporated on the above ITO film as the anode layer, and the thickness of the evaporated film is Continue to evaporate compounds HI01 and F4TCNQ as hole injection layers, where F4TCNQ is 3% of the mass of HI01 and the evaporated film thickness is

[0152] 3) Continue to evaporate the compound HTM on the hole injection layer to form a hole transport layer, and the evaporated film thickness is

[0153] 4) The compound represented by formula (I) of the present invention is continuously evaporated on the hole transport layer as an electron blocking layer, and the evaporated film thickness is

[0154] 5) Compound BH018 as the main material and BD041 as the doping material are continuously evaporated on the electron blocking layer, BD041 is 8% of the mass of BH018, and the organic light-emitting layer obtained by evaporation has a film thickness of

[0155] 6) A layer of LiQ and compound ET028 is continuously evaporated on the organic light-emitting layer as the electron transport layer of the element, wherein the compound ET028 is 50% of the mass of LiQ and the evaporated film thickness is

[0156] 7) Continue to evaporate a layer of LiF on the electron transport layer as an electron injection layer, and the evaporated film thickness is

[0157] 8) On the electron injection layer, magnesium and silver are evaporated as the transparent cathode layer of the element. The mass ratio of magnesium to silver is 1:10, and the thickness of the evaporated film is

[0158] 9) On top of the transparent cathode layer, a layer of CPD is evaporated as the CPL layer of the element. The thickness of the evaporated film is The OLED element provided by the present invention is obtained.

[0159] The structure of the compound used in Example 4 is as follows:

[0160]

[0161] Example 5

[0162] An organic electroluminescent element 200, the structure of which is as follows Figure 2As shown, it includes a substrate 201, an anode layer 202, a hole injection layer 203, a hole transport layer 204, a first light-emitting layer 205, an electron transport layer 206, a charge generation layer 207, a hole injection layer 208, a hole transport layer 209, a second light-emitting layer 210, an electron transport layer 211, an electron injection layer 212 and a cathode layer 213.

[0163] Comparative Example 1

[0164] According to the same steps as in Example 4, the compound of formula (I) of the present invention in step 4) is replaced by H01 to obtain comparative element 1;

[0165]

[0166] Comparative Example 2

[0167] According to the same steps as in Example 4, the compound of formula (I) of the present invention in step 4) is replaced by H02 to obtain comparative element 2;

[0168]

[0169] Comparative Example 3

[0170] According to the same steps as in Example 4, the compound of formula (I) of the present invention in step 4) is replaced by H03 to obtain comparative element 3;

[0171]

[0172] Comparative Example 4

[0173] According to the same steps as in Example 4, the compound of formula (I) of the present invention in step 4) is replaced by H04 to obtain comparative element 4;

[0174]

[0175] The organic electroluminescent element prepared by the above process was subjected to the following performance tests:

[0176] The driving voltage and current efficiency of the organic electroluminescent elements prepared in Examples 4 and 5 and Comparative Examples 1 to 4 and the life of the elements were measured using a digital source meter and a brightness meter. Specifically, the voltage was increased at a rate of 0.1 V per second, and the brightness of the organic electroluminescent element was measured when it reached 1000 cd / m 2 The voltage at which the light is on is the driving voltage, and the current density at this time is measured at the same time; the ratio of brightness to current density is the current efficiency; the LT95% life test is as follows: use a brightness meter at 1000cd / m 2 At the same brightness, the current is kept constant and the brightness decay of the organic electroluminescent element is measured to be 950cd / m 2The data listed in Table 4 are relative data compared with Comparative Element 1.

[0177] Table 4

[0178]

[0179]

[0180]

[0181]

[0182] In the above table, Me is a methyl group, Ph is a phenyl group, PhPh is a biphenyl group, Nap is a naphthyl group, FR is a 9,9-fluorenyl group, and Ad is an adamantyl group.

[0183] As shown in Table 4, the element prepared from the fluorene derivative of the present invention has a lower driving voltage than H01 at the same brightness, and the current efficiency is significantly improved, up to 1.3 times that of the comparative element, and the LT95% life of the element is greatly improved.

[0184] The difference between compound H01 in comparative example 1 and the compound of the present invention is that the two phenyl groups are connected by an olefin bond in fluorene, while the compound of the present invention introduces an alkyl group on fluorene, which reduces the conjugation ability. It has better performance in molecular film formation and charge blocking, and the transmission of carriers in the element is more balanced, so the element performance is significantly improved.

[0185] The difference between the compound H02 in Comparative Example 2 and the compound of the present invention is that the two fluorene groups are connected by an olefin bond, the planar conjugation ability is enhanced, and it is easier to form a carbon carbene ion, so the electron transport performance is improved, and the hole transport and electron blocking performance are reduced, resulting in high voltage and reduced efficiency. The compound of the present invention introduces an alkyl or cycloalkyl group on the fluorene to prevent the formation of a carbon carbene ion, and the electron blocking performance is improved. Therefore, it has better performance in molecular film formation and charge blocking, and the charge transmission in the element is more balanced, so the element performance is significantly improved.

[0186] The difference between the compound H03 in comparative example 3 and the compound of the present invention is that the planar conjugation ability of fluorene is enhanced, and the hole transport and charge blocking properties are reduced, resulting in high voltage and reduced efficiency. The compound of the present invention introduces alkyl or aralkyl substituents on the olefin bond, and the hole transport performance is improved. Therefore, it is more excellent in molecular film formation and charge blocking performance, and the charge transfer in the element is more balanced, so the element performance is significantly improved.

[0187] The difference between the compound H04 in comparative example 4 and the compound of the present invention is that the fused electron-donating group is introduced on the basis of fluorene, the planar conjugation ability is enhanced, the charge transfer performance is improved, resulting in unbalanced transfer of excitons in the element, increased voltage and reduced efficiency. However, after the introduction of the alkyl group, the compound of the present invention blocks the movement of excitons toward the anode, and the transfer of charges in the element is more balanced, so the element performance is significantly improved.

[0188] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A fluorene derivative, characterized in that: The fluorene derivative is selected from the compounds shown in the following formula D475-D606: Wherein, *—T1—*, *—T2—* are each independently selected from *—O—*, *—S—* or one of the following structures: *— and —* represent connecting keys.

2. Use of the fluorene derivative according to claim 1 in the preparation of an organic electroluminescent element.

3. An organic electroluminescent element, characterized in that: It includes: A first electrode, a second electrode, a capping layer, and one or more organic layers disposed between the first electrode and the second electrode; The material of at least one of the organic layer and the capping layer comprises the fluorene derivative according to claim 1.

4. The organic electroluminescent element according to claim 3, characterized in that: The organic layer includes a hole injection layer, a hole transport layer, a hole blocking layer, a light emitting layer, an electron transport layer, an electron injection layer or an electron blocking layer.

5. A consumer product, characterized in that: It comprises the organic electroluminescent element as claimed in claim 3.

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