A heterocyclic compound and its application

Abstract

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

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescent materials, and in particular to a heterocyclic compound 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 matured, 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.; especially the substances used in electron transport layer and hole blocking layer, as the earliest reports related to electron transport materials, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives and patents in CN107573328A, CN107556310A, CN113801066A, CN113429395A, CN113429348A, CN114560872A, etc. can be cited as representative electron transport layer substances with imidazole groups. The structure contains 1,3,4-oxadiazole groups, which have the ability to transmit electrons in terms of function, but there is a problem of low thermal stability when applied to actual components.

[0004] Therefore, in order to overcome the above-mentioned problems of the prior art and further improve the characteristics of the organic electroluminescent element, there continues to be a demand for the development of more stable and effective substances that can be used as electron transport and hole blocking substances in the organic electroluminescent element.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The object of the present invention is to provide a heterocyclic compound, which can improve the thermal stability of the material and the ability to transport carriers. The organic electroluminescent element prepared using the heterocyclic compound 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.

[0007] Specifically, the present invention provides the following technical solutions:

[0008] The present invention provides a heterocyclic compound, the structural formula of which is shown in formula (I):

[0009]

[0010] in,

[0011] Ar 1 Selected from substituted or unsubstituted C2-C 60 The group consisting of heteroaryl;

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

[0013] L 2 , L 3 Each is independently selected from a single bond, a substituted or unsubstituted C6-C 60 Arylene, or substituted or unsubstituted C2-C 60 The group consisting of heteroarylene;

[0014] X 1 , X 2 , X 3 Each independently is CR 1 or N, and x 1 , X 2 , X 3 The total number of N is 1 or 3;

[0015] R 1 selected from hydrogen, deuterium, fluorine, 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 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-C 60 Arylthio, substituted or unsubstituted C6-C 60 Arylsulfoxide, substituted or unsubstituted C3-C 40 silyl, substituted or unsubstituted boron, substituted or unsubstituted amine, substituted or unsubstituted arylphosphino, substituted or unsubstituted phosphine oxide, or substituted or unsubstituted C2-C 60 The group consisting of heteroaryl;

[0016] Ar 2 ,Ar 3 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 heteroaryl groups.

[0017] 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.

[0018] The heterocyclic compound according to the present invention is represented by the above chemical formula (I), wherein the 1,3,4-oxadiazole group and the heteroaryl group containing heteroatoms and the 3,5-disubstituted aryl or heteroaryl group are connected through the arylene group, the heteroarylene group L 1 Combined to form a basic skeleton. The compound represented by formula (I) of the present invention is not only electrochemically stable and excellent in electron mobility, but also has a high glass transition temperature and excellent thermal stability compared to the previously known oxadiazole derivatives. As a result, the heterocyclic compound of the present invention has excellent electron transport ability and luminescent properties, and can therefore be used as a material for any one of the light-emitting layer, electron transport layer and hole blocking layer of the organic layer of an organic electroluminescent element. It is preferably a material that can be used as any one of the light-emitting layer, electron transport layer and electron transport auxiliary layer stacked one step on the hole blocking layer, and more preferably a material that can be used as an electron transport layer or an electron transport auxiliary layer.

[0019] Specifically, the compound shown in the compound formula (I) of the present invention is a heterocyclic compound comprising heteroaryl oxadiazole, so as to have a stronger electron transfer ability compared with the derivative of aryl oxadiazole with weak electron withdrawing group ability, and can show relatively high luminous efficiency and high glass transition temperature. Thus, in the case where the heterocyclic compound shown in the formula (I) of the present invention is used for an organic electroluminescent element, it is possible to expect not only excellent thermal stability and carrier transport ability, especially electron transport ability and luminescence ability, but also to reduce the driving voltage of the element, improve efficiency and lifespan, etc., and as the latest electron transport layer material, it is possible to show the excellent efficiency rise caused by the triplet-triplet fusion effect due to the high triplet energy level.

[0020] In addition, the heterocyclic compound represented by formula (I) of the present invention is prepared by introducing various substituents Ar into the basic skeleton. 1 ,Ar 2 and Ar 3The HOMO and LUMO energy levels can be adjusted according to the type of the substituent, thereby having a wide band gap, and an organic electroluminescent element using such a compound can exhibit the highest electron transport property.

[0021] In addition, the heterocyclic compound represented by formula (I) of the present invention is modified by introducing various substituents L into the above basic skeleton. 1 , L 2 , L 3 , especially aryl and / or heteroaryl Ar 2 and Ar 3 , the molecular weight of the compound is significantly increased, thereby increasing the glass transition temperature, thereby having higher thermal stability than previous luminescent materials, such as oxadiazoles connected by multiple aromatic groups. 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.

[0022] Preferably, the R 1 is selected from the group consisting of hydrogen, deuterium, fluorine, nitrile, methyl, phenyl, biphenyl, terphenyl, naphthyl, pyridyl, phenanthryl, triphenylene, carbazolyl, fluorenyl, dibenzofuranyl or dibenzothiophenyl.

[0023] 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.

[0024] 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.

[0025] Preferably, the aryl, condensed ring aryl, and heteroaryl can be 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, indolocarbazolyl, benzofuranocarbazolyl, benzothiophenocarbazolyl, benzocarbazolyl, dibenzocarbazolyl, azadibenzo[g,ij]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.

[0026] Furthermore, the Ar 2 ,Ar 3 Each is independently 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, indolocarbazolyl, benzofuranocarbazolyl, benzothiophenocarbazolyl, benzocarbazolyl, dibenzocarbazolyl, azadibenzo[g,ij]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.

[0027] In the heterocyclic compound represented by formula (I) of the present invention, Ar 1 can be selected from the group consisting of commonly known electron-withdrawing groups, in which case the Ar 1 It is preferably selected from the group consisting of the following groups shown in II-1 to II-13:

[0028]

[0029] in,

[0030] Z1 and Z2 are each independently selected from hydrogen, deuterium, halogen, hydroxyl, nitrile, nitro, amino, amidine, hydrazine, hydrazone, carboxyl or its carboxylate, sulfonic acid or its sulfonate, phosphoric acid or its phosphate, C1-C 40 Alkyl, C2-C 40 Alkenyl, C2-C 40 Alkynyl, C1-C 40 Alkoxy, C3-C 40 Cycloalkane, C3-C 40 Cycloalkene, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C6-C 60 Aryloxy, substituted or unsubstituted C6-C 60 Aryl thioether, substituted or unsubstituted C6-C 60 Arylamine, or substituted or unsubstituted C2-C 60 The group consisting of heteroaryl;

[0031] x1 represents an integer from 1 to 4; x2 represents an integer from 1 to 3; x3 represents 1 or 2; x4 represents an integer from 1 to 6; x5 represents an integer from 1 to 5;

[0032] T1 represents O, S or NAr';

[0033] Ar' is selected from C1~C 40 Alkyl, C1~C 40 Heteroalkyl, C3~C 40 Cycloalkyl, 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 heteroaryl; preferably, Ar' is methyl, ethyl, phenyl, biphenyl or naphthyl;

[0034] Ar 1 A bond to 1,3,4-oxadiazole;

[0035] The groups represented by the above formulae II-1 to II-13 can be independently selected from deuterium, halogen atoms, nitrile groups, nitro groups, C1-C 40 Alkyl, C2-C 40 Alkenyl, C2-C 40 Alkynyl, C3-C 40 Cycloalkyl, C3-C 40 Heterocycloalkyl, C6-C 60 Aryl and C2-C 60Heterocyclic aromatic group, C1-C 40 Alkoxy, C6-C 60 Aryloxy, C1-C 40 Alkylsilyl, C6-C 60 Arylsilyl, C1-C 40 Alkyl boron, C6-C 60 Aryl boron, C6-C 60 Arylphosphino, C1-C 60 Arylphosphine oxide and C6-C 60 The arylamine group may be substituted with one or more substituents. In this case, when there are multiple substituents, the multiple substituents are preferably the same as or different from each other.

[0036] In the heterocyclic compound represented by formula (I) of the present invention, L 1 In order to combine the above-mentioned 1,3,4-oxadiazole derivative containing a heteroaryl group with the above-mentioned Ar-containing 2 and Ar 3 The functional group connected to the aryl or heteroaryl group can be selected from C6-C 60 Arylene and C2-C 60 The group of heteroarylene groups, in this case, preferably, the L 1 Selected from the group consisting of the following groups III-1 to III-25. 2 , L 3 As with Ar 2 and Ar 3 The connecting group can be selected from single bonds, C6-C 60 Arylene and C2-C 60 The group of heteroarylene groups, in this case, preferably, the L 2 , L 3 Selected from the group consisting of a single bond or the following groups represented by III-1 to III-25. The groups represented by III-1 to III-25 are:

[0037]

[0038] Wherein, X is selected from O, S, Se, CR 2 R 3 、SiR 2 R 3 or NAr 3 ;

[0039] Z 11 , Z 12 , Z 13 , Z 14Each is independently 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 60 Alkyl, C2-C 60 Alkenyl, C2-C 60 Alkynyl, C1-C 60 Alkoxy, C3-C 60 Cycloalkane, C3-C 60 Cycloalkene, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C6-C 60 Aryloxy, substituted or unsubstituted C6-C 60 aryl thioether group, or substituted or unsubstituted C2-C 60 The group consisting of heteroaryl;

[0040] y1 represents an integer of 1-4; y2 represents an integer of 1-6; y3 represents an integer of 1-3; y4 represents an integer of 1-5; y5 represents an integer of 1 or 2;

[0041] R 2 , R 3 Each independently selected from C1-C 60 Alkyl, C1-C 60 heteroalkyl, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C6-C 60 Arylamine, or substituted or unsubstituted C2-C 60 The group consisting of heteroaryl groups, R 2 and R 3 may be optionally joined or fused to form one or more additional substituted or unsubstituted rings, containing or not containing one or more heteroatoms N, P, B, O or S in the formed ring; preferably, R 2 , R 3 is methyl, phenyl or fluorenyl;

[0042] Ar 3 Choose from C1-C 60 Alkyl, C1-C 60 Heteroalkyl, C3-C 60 Cycloalkyl, 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 heteroaryl; preferably, Ar 3 is methyl, ethyl, phenyl, biphenyl or naphthyl;

[0043] 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-25 is not limited and can be ortho, meta, or para. 2 , L 3 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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 yl, trifluoromethoxy, pentafluoroethoxy, pentafluoroethylthio, 2,2,2-trifluoroethoxy, 2,2,2-trifluoroethylthio, vinyloxy, vinylthio, propenyloxy, propenylthio, butenylthio, butenyloxy, pentenyloxy, pentenylthio, cyclopentenyloxy, cyclopentenylthio, hexenyloxy, hexenylthio, cyclohexenyloxy, cyclohexenylthio, ethynyloxy, ethynylthio, propynyloxy, propynylthio, butynyloxy, butynylthio, pentynyloxy, pentynylthio, hexynyloxy, and hexynylthio.

[0048] 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.

[0049] The heterocycloalkyl 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.

[0050] 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.

[0051] The alkoxy group used in the present invention refers to a monovalent functional group represented by RO-, wherein R is an alkyl group having 1 to 40 carbon atoms, which may include a linear, branched or cyclic 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.

[0052] The aryloxy group used in the present invention refers to a monovalent functional group represented by R'O-, wherein R' is an aryl group having a carbon number of 6 to 60. Non-limiting examples of such aryloxy groups include phenoxy, naphthoxy, biphenyloxy and the like.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] Preferably, the heterocyclic compound can be selected from the compounds shown in the following formulas J475-J663:

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066] The present invention also provides a method for preparing the heterocyclic compound described above, as shown in Scheme 1:

[0067] Option 1,

[0068]

[0069] In Scheme 1, the symbols used are as defined in formula (I), and Y is Cl, Br, I or OTf;

[0070] 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.

[0071] Specifically, the compound of formula (I) is composed of an aldehyde-containing Ar 1 The intermediate S1 containing a halogen atom is reacted with a hydrazide to prepare a 1,3,4-oxadiazole intermediate S1; the intermediate S1 containing a halogen atom is reacted with a biboric acid pinacol ester or a boric acid ester to prepare a boronic acid or a boronic acid pinacol ester intermediate S2; the boronic acid or a boronic acid pinacol ester intermediate S2 is reacted with a halogen atom containing a halogen atom 2 and Ar 3 The compound of formula (I) of the present invention is prepared by Suzuki coupling reaction of the halogenated aryl or halogenated heteroaryl S3. The intermediate S3 is prepared by palladium-catalyzed or base-catalyzed coupling reaction.

[0072] The palladium catalyst that can be used for the palladium-catalyzed coupling reaction can be selected from: Pd(P- tAny 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.

[0073] 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.

[0074] 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 a mixture of one or more thereof can be used.

[0075] The present invention also provides an organic electroluminescent material, the raw material of which includes the heterocyclic compound mentioned above; the organic electroluminescent material including the heterocyclic compound of the present invention has the ability of carrier transport.

[0076] The present invention also provides the use of the above heterocyclic compound in the preparation of an organic electroluminescent element.

[0077] 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 heterocyclic compound described above.

[0078] 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 heterocyclic compound of the present invention.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] In addition, the present invention relates to a heterocyclic compound of the present invention comprising at least one indicated above. The same preferred conditions as indicated above for organic electroluminescent elements apply to the compounds of the present invention. In particular, other compounds may also be preferably included in addition to the heterocyclic compound. From the liquid phase, the heterocyclic compound of the present invention is processed, for example, by spin coating or by a printing method, and a preparation for processing the compound of the present invention is required. These preparations may be, for example, 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 benzothiazole, butyl benzoate, isopropylbenzene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decahydronaphthalene, 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.

[0087] 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.

[0088] Furthermore, the light-emitting layer, electron transport layer, electron injection layer or hole blocking layer comprises the heterocyclic compound of the present invention.

[0089] The present invention also provides a consumer product, which includes the organic electroluminescent element mentioned above.

[0090] 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.

[0091] The beneficial effects achieved by the present invention are:

[0092] The heterocyclic compound 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 electron mobility, thermal stability and luminescent properties. In particular, when the heterocyclic compound represented by formula (I) of the present invention is used in an electron transport layer and an electron transport auxiliary layer, an organic electroluminescent element having a lower driving voltage, higher efficiency and longer life than conventional electron transport 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

[0093] 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 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 110, and a capping layer (CPL) 111. The device 100 may be manufactured by depositing the described layers in order.

[0094] Figure 2 Schematic diagram of an organic light-emitting device 200 showing two light-emitting layers. The device includes a substrate 201, an anode 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 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 100 can be used. Figure 2 One example is provided of how some layers may be added from the structure of device 100 . DETAILED DESCRIPTION

[0095] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0096] 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.

[0097] 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.

[0098] The test instruments and methods for testing the performance of OLED materials and components in the following embodiments are as follows:

[0099] OLED component performance testing conditions:

[0100] Brightness and chromaticity coordinates: tested using a spectrum scanner PhotoResearch PR-715;

[0101] Current density and lighting voltage: tested using Keithley 2420 digital source meter;

[0102] Power efficiency: Tested using NEWPORT 1931-C.

[0103] Example 1

[0104] The preparation method of compound J633 comprises the following steps:

[0105] Step 1: Preparation of intermediate Int-1

[0106]

[0107] Under nitrogen protection, 20.0 mmol of benzoazole-2-carboxaldehyde was dissolved in 60 mL of dry THF, 20.0 mmol of p-bromobenzohydrazide was added, the temperature was raised to reflux and stirred for reaction for 2 hours, and the mixture was concentrated to dryness under reduced pressure. The residue was dissolved in 50 mL of dimethyl sulfoxide, 24.0 mmol of iodine and 60.0 mmol of anhydrous potassium carbonate were added, the temperature was raised to 130 ° C and stirred for reaction for 1 hour, and the mixture was cooled to room temperature. The reaction solution was poured into 150 mL of ice water and filtered. The filter cake was washed with water and methanol to obtain compound Int-1 as a white solid with a yield of 85%.

[0108] Step 2: Preparation of intermediate Int-2

[0109]

[0110] Under nitrogen protection, 20.0 mmol of Int-1 was dissolved in 60 mL of dry DMF, and 24.0 mmol of bipyralidone, 30.0 mmol of anhydrous potassium acetate, 0.2 mmol of PdCl2 (dppf) and 2.0 mmol of cuprous iodide were added. The temperature was raised to 90°C and stirred for reaction for 12 hours. The temperature was cooled to room temperature, and the reaction solution was poured into 120 mL of water and filtered. The filter cake was washed with water and dried, and then separated and purified by silica gel column to obtain a white solid with a yield of 82%.

[0111] Step 3: Preparation of compound J633

[0112]

[0113] Under nitrogen protection, 12.0 mmol of intermediate Int-2 (reactant 1), 10.0 mmol of 2-(4-bromophenyl)-4,6-diphenyl-1,3,5-triazine (reactant 2), 36.0 mmol of anhydrous sodium 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. The temperature was raised to reflux and stirred for reaction for 12 hours, cooled to room temperature, 50 mL of water was added to dilute, extracted with dichloromethane, the organic phase was collected, dried, filtered, and the filtrate was concentrated under reduced pressure to dryness, and separated and purified by silica gel column to obtain compound J633 as a white solid with a yield of 77%. MS (MALDI-TOF): m / z=571.1896 [M+H] + ; 1 HNMR (6, CDCl3): 8.77~8.76 (4H, d); 8.35~8.31 (2H, m); 8.24~8.20 (2H, m); 8.05~8.03 (1H, m); 7.92~7.85 (5H, m); 7.53~7.41 (8H, m).

[0114] Referring to the above-mentioned similar synthesis method, the compounds shown in Table 1 below were prepared:

[0115] Table 1

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129] Example 2

[0130] An OLED element, such as Figure 1 As shown, the OLED element of this embodiment is a top emission element, comprising 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:

[0131] 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.

[0132] 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

[0133] 3) Continue to evaporate the compound CPD on the hole injection layer to form a hole transport layer, and the evaporated film thickness is

[0134] 4) Continue to evaporate the compound EBL on the hole transport layer as an electron blocking layer, and the evaporated film thickness is

[0135] 5) Compound RH11 is continuously evaporated on the electron blocking layer as the main material and RD11 is the doping material, RD11 is 3% of the mass of compound RH11, and the organic light-emitting layer obtained by evaporation has a film thickness of

[0136] 6) A layer of LiQ and the compound of formula (I) of the present invention is continuously evaporated on the organic light-emitting layer as the electron transport layer of the element, wherein the compound of formula (I) is 50% of the mass of LiQ and the evaporated film thickness is

[0137] 7) Continue to evaporate a layer of LiF on the electron transport layer as an electron injection layer, and the evaporated film thickness is

[0138] 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

[0139] 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 This leads to the OLED element provided by the present invention.

[0140] The structure of the compound used in Example 2 is as follows:

[0141]

[0142] Example 3

[0143] An organic electroluminescent element 200, the structure of which is as follows Figure 2 As shown, it includes a substrate 201, an anode 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 213.

[0144] Comparative Example 1

[0145] According to the same steps as Example 2, the compound of formula (I) in step 6) was replaced by E01 to obtain comparative element 1;

[0146]

[0147] Comparative Example 2

[0148] According to the same steps as Example 2, the compound of formula (I) in step 6) was replaced by E02 to obtain comparative element 2;

[0149]

[0150] Comparative Example 3

[0151] According to the same steps as Example 2, the compound of formula (I) in step 6) was replaced by E03 to obtain comparative element 3;

[0152]

[0153] Comparative Example 4

[0154] According to the same steps as in Example 2, the compound of formula (I) in step 6) was replaced with E04 to obtain comparative element 4;

[0155]

[0156] The organic electroluminescent element prepared by the above process was subjected to the following performance tests:

[0157] The driving voltage and current efficiency of the organic electroluminescent elements prepared in Examples 2 and 3 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 2 The data listed in Table 2 are relative data compared with the comparative element 1, and the data in brackets in the comparative element 1 (the test material is E01) are the test data.

[0158] Table 2

[0159]

[0160]

[0161]

[0162]

[0163]

[0164]

[0165] As shown in Table 2, the device prepared from the heterocyclic compound of the present invention has a lower driving voltage than E01 at the same brightness, and the current efficiency is significantly improved, up to 1.2 times that of the comparative device, and the LT95% life of the device is greatly improved.

[0166] The difference between the compound E01 in comparative example 1 and the compound of the present invention is that the 2,5 positions of 1,3,4-oxadiazole are electron-donating phenyl groups, and after the introduction of the strong electron-withdrawing triazine group, an electron-donating-electron-withdrawing (DA) type molecule is formed, the electron cloud density of the 1,3,4-oxadiazole group is reduced, and the charge transfer performance is reduced, resulting in high voltage and low efficiency. The compound of the present invention, after the heteroaryl group is introduced into the 2 position of 1,3,4-oxadiazole, enhances the electron-withdrawing ability of the oxadiazole group to form an electron-withdrawing-electron-withdrawing (AA) type molecule, which has better performance in molecular film formation and charge transfer, and the charge transfer in the element is more balanced, so the element performance is significantly improved.

[0167] The difference between the compound E02 in comparative example 2 and the compound of the present invention is that two triazine groups are simultaneously introduced on the 2 and 5 phenyl groups of 1,3,4-oxadiazole to form a symmetrical molecule. Due to the strong electron-withdrawing of the triazine group, the electron cloud density of the oxadiazole group at the center of the molecule is reduced, and the charge transfer performance is reduced, resulting in high voltage and reduced stability. The compound of the present invention adds an electron-withdrawing heteroaryl group at the 2 position of oxadiazole, and the electron cloud distribution of the molecule reaches a balance. It has better performance in molecular film formation and charge transfer, and the charge transfer in the element is more balanced, so the element performance is significantly improved.

[0168] The difference between compound E03 in comparative example 3 and the compound of the present invention is that two 2-phenyl 1,3,4-oxadiazoles are connected to a triazine group, and the highest occupied orbital of the molecule is distributed on the two oxadiazole groups, and the planar conjugation ability of the oxadiazole groups is weak. Therefore, the film-forming and charge transfer properties of the molecule are reduced, resulting in reduced efficiency.

[0169] The difference between the compound E04 in comparative example 4 and the compound of the present invention is that the 2-position of 1,3,4-oxadiazole is phenyl, and only after the introduction of the substituted pyrimidine group at the 5-position, the planar conjugation ability decreases, the molecular film-forming and charge transfer performance decreases, resulting in high voltage and reduced efficiency. The compound of the present invention optimizes the molecular design, introduces an electron-withdrawing group at the 2-position of 1,3,4-oxadiazole to jointly form a strong electron-withdrawing group, and forms an AA-shaped molecule after the electron-withdrawing group is introduced at the 5-position to improve the electron transfer performance. Therefore, it has better performance in molecular film-forming and charge transfer, and the charge transfer in the element is more balanced, so the element performance is significantly improved.

[0170] 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 heterocyclic compound, characterized in that The heterocyclic compound is selected from the following compounds:

2. Use of the heterocyclic compound 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 layers comprises the heterocyclic compound 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. The organic electroluminescent element according to claim 4, characterized in that: The electron transport layer comprises the heterocyclic compound according to claim 1.

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

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