Quinoxaline compound and organic electroluminescent device

Abstract

The invention provides a quinoxaline compound and an organic electroluminescent device, and belongs to the technical field of electroluminescent materials. The quinoxaline compound has a structure as shown in a formula I. The structure of the quinoxaline compound is designed, so that the quinoxaline compound is suitable for being used as a main body material of a light-emitting layer of the organic light-emitting device, and the organic light-emitting device has relatively high current efficiency, relatively long service life and relatively low driving voltage.

Description

Technical Field

[0001] The present invention belongs to the technical field of electroluminescent materials, and particularly relates to a quinoxaline compound and an organic electroluminescent device. Background Art

[0002] Electroluminescence, also known as field luminescence, abbreviated as EL, is a luminescence phenomenon in which an electric field is generated by a voltage applied to two electrodes, and a solid directly converts electrical energy into light energy under the action of the electric field. Among them, the electroluminescence of organic materials belongs to injection-type recombination luminescence. Organic electroluminescent materials can be further classified into hole injection layer (HIL), hole transport layer (HTL), emission layer (EML), electron transport layer (ETL), electron injection layer (EIL), etc. according to their functions in organic electroluminescent (OLED) devices and different device structures.

[0003] Currently, organic electroluminescence (OLED) has become the mainstream display technology. Correspondingly, various new OLED materials have been developed. However, their various performances still need to be improved, especially in terms of efficiency, lifespan, voltage, etc. In order to meet people's higher requirements for OLED devices, there is an urgent need to develop more types of high-performance blue host materials in this field. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a quinoxaline compound and an organic electroluminescent device. In the present invention, by designing the structure of the quinoxaline compound, it is suitable as the host material of the emission layer of the organic electroluminescent device, so that the organic electroluminescent device has a higher current efficiency, a longer lifespan and a lower driving voltage.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a quinoxaline compound, and the quinoxaline compound has the structure shown in the following formula I:

[0007]

[0008] Wherein, Ar is selected from any one of C6-C40 aryl or C6-C30 heteroaryl;

[0009] Wherein, Ar 1 、Ar 2 、Ar 3 、Ar 4 are each independently selected from any one of H, C6-C40 aryl or C6-C30 heteroaryl, and Ar 1 、Ar 2 、Ar 4At least one of them is selected from any one of C6-C40 aryl or C6-C30 heteroaryl;

[0010] R 1 and R 2 are each independently selected from any one of C6-C40 aryl or C6-C30 heteroaryl;

[0011] m and n are each independently selected from integers between 0 and 4;

[0012] The hydrogen atoms in the compound of formula I can each independently be substituted by at least one of deuterium atom (D), -F, -CN, C6-C20 aryl, C1-C12 alkyl or C1-C12 alkoxy.

[0013] In the present invention, by designing the structure of quinoxaline compounds, they are suitable as host materials for the light-emitting layer of organic electroluminescent devices, so that the organic electroluminescent devices have high current efficiency, long lifespan and low driving voltage.

[0014] It should be noted that in the present invention, "D" represents deuterium atom. Where not separately marked in the present invention, H and hydrogen therein both represent "protium", the same hereinafter.

[0015] In the present invention, C6-C40 can be C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.

[0016] C6-C30 can be C6, C8, C10, C12, C16, C20, C24, C28 or C30, etc.

[0017] C1-C12 can be C1, C2, C4, C6, C8, C10 or C12, etc.

[0018] C6-C20 can be C6, C8, C10, C12, C16 or C20, etc.

[0019] The following are preferred technical solutions of the present invention, but not limitations to the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved.

[0020] As a preferred technical solution of the present invention, the C6-C40 aryl is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, naphthylphenyl, anthryl, phenanthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthofluorenyl, pyrenyl, perylenyl, spirofluorenyl, triphenylenyl, fluoranthenyl, hydrobenzanthryl, indeno[1,2-b]fluorene, benzindeno[1,2-b]fluorene, dibenzindeno[1,2-b]fluorene, naphthofluorenyl or benzonaphthofluorenyl.

[0021] As a preferred technical solution of the present invention, the C6-C30 heteroaryl is selected from any one of carbazolyl, dibenzofuranyl, dibenzothiophenyl, naphthobenzofuranyl, naphthobenzothiophenyl, dinaphthofuranyl, dinaphthothiophenyl.

[0022] As a preferred technical solution of the present invention, the C6-C20 aryl is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthryl, phenanthryl, fluorenyl, triphenylene, fluoranthenyl.

[0023] As a preferred technical solution of the present invention, the C1-C12 alkyl is selected from any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl or decyl.

[0024] As a preferred technical solution of the present invention, the C1-C12 alkoxy is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy.

[0025] As a preferred technical solution of the present invention, Ar is selected from any one of phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthenyl, indeno[1,2-b]fluorene, dibenzofuranyl, dibenzothiophenyl, naphthobenzofuranyl or naphthobenzothiophenyl.

[0026] Preferably, Ar is selected from at least one of phenyl, biphenyl, naphthyl, dibenzofuranyl, dibenzothiophenyl or carbazolyl.

[0027] As a preferred technical solution of the present invention, the Ar 1 、Ar 2 、Ar 3 、Ar 4 are each independently selected from any one of phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthenyl, indeno[1,2-b]fluorene, dibenzofuranyl, dibenzothiophenyl, naphthobenzofuranyl or naphthobenzothiophenyl.

[0028] Preferably, the Ar 1 、Ar 2 、Ar 3 、Ar 4 are each independently selected from any one of H, phenyl, biphenyl, naphthyl, dibenzofuranyl, dibenzothiophenyl or carbazolyl.

[0029] As a preferred technical solution of the present invention, the Ar 1 、Ar 3 、Ar 4 is selected from H, and the Ar 2 is selected from any one of phenyl, biphenyl, dibenzofuranyl, dibenzothiophenyl or carbazolyl.

[0030] Preferably, the Ar 1 and Ar 2 and Ar 3 are selected from H, and the Ar 4 is selected from any one of phenyl, biphenyl or naphthyl.

[0031] As a preferred technical solution of the present invention, the R 1 and R 2 each independently is selected from any one of phenyl, carbazolyl, biphenyl, fluorene, naphthyl, triphenylene, fluoranthene, indeno[1,2-b]fluorene, dibenzofuran, dibenzothiophene, naphtho[2,3-b]furan or naphtho[2,3-b]thiophene.

[0032] Preferably, the R 1 and R 2 each independently is selected from any one of phenyl, biphenyl, naphthyl, dibenzofuran, dibenzothiophene or carbazolyl. As a preferred technical solution of the present invention, m = 0 and n = 0.

[0033] As a preferred technical solution of the present invention, m + n = 1.

[0034] As a preferred technical solution of the present invention, m = 0 and n = 1.

[0035] As a preferred technical solution of the present invention, m + n = 2.

[0036] As a preferred technical solution of the present invention, m = 2 and n = 0.

[0037] As a preferred technical solution of the present invention, m = 1 and n = 1.

[0038] As a preferred technical solution of the present invention, the hydrogen atoms in the compound of formula I can each independently be substituted by at least one of -D, -F, -CN, phenyl, naphthyl, biphenyl, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy or butoxy.

[0039] Preferably, the hydrogen atoms in the compound of formula I can each independently be substituted by at least one of -D, -F, -CN, methyl, ethyl, propyl, tert-butyl, methoxy, ethoxy, propoxy, phenyl, naphthyl.

[0040] As a preferred technical solution of the present invention, the quinoxaline compounds are selected from any one of the following substituted or unsubstituted compounds:

[0041]

[0042]

[0043]

[0044] The substitution means that each hydrogen atom in the above-mentioned quinoxaline compounds can be independently substituted by a deuterium atom.

[0045] Preferably, the quinoxaline compound is selected from any one of the following compounds:

[0046]

[0047] It should be noted that the present invention has no special restrictions on the preparation method of the above-mentioned quinoxaline compounds, and the commonly used preparation methods in the art are applicable.

[0048] In a second aspect, the present invention provides an intermediate, and the intermediate includes the following compounds:

[0049]

[0050] The intermediate is used for preparing the quinoxaline compound as described in the first aspect.

[0051] In a third aspect, the present invention provides an organic electroluminescent device, and the organic electroluminescent device includes an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode;

[0052] The organic thin film layer includes the quinoxaline compound as described in the first aspect.

[0053] As a preferred technical solution of the present invention, the organic thin film layer includes a light-emitting layer, and the host material of the light-emitting layer includes the quinoxaline compound as described in the first aspect.

[0054] Preferably, the light-emitting layer is a phosphorescent light-emitting layer.

[0055] As a preferred technical solution of the present invention, the organic electroluminescent device is a blue organic electroluminescent device.

[0056] In the present invention, the light-emitting layer includes a light-emitting layer host material and a doping material, and the doping material is also called a dye or a phosphorescent light-emitting material. The light-emitting layer host material can be a single compound or a mixture formed by two or more compounds.

[0057] The light-emitting layer includes a phosphorescent light-emitting layer, and the phosphorescent light-emitting layer includes a green phosphorescent light-emitting layer, a red phosphorescent light-emitting layer, and a yellow phosphorescent light-emitting layer.

[0058] The volume percentage content of the host material in the phosphorescent light-emitting layer is 60% to 99.9% (for example, it can be 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99.9%, etc.), preferably 70% to 99.5%, and further preferably 85% to 95%.

[0059] In the present invention, the doping material of the light-emitting layer may be a phosphorescent material. The phosphorescent material, also known as a triplet light-emitting material, refers to the light emitted by a substance from the triplet excited state. In the present invention, the specific selection of the phosphorescent material is not particularly limited, and common doping materials for the light-emitting layer in the art are applicable. Exemplarily, but not limited to, compounds having the structure shown in formula PD:

[0060]

[0061] Among them, M is selected from any one of Ir, Pt, Pd, Os, Ti, Zr, Hf, Eu, Tb, Tm, Cu, or Au;

[0062] Y 1 -Y 4 Each independently is selected from carbon or nitrogen;

[0063] Y 1 and Y 2 can be connected by a single bond or a double bond, and Y 3 and Y 4 can be connected by a single bond or a double bond;

[0064] Cy 1 and Cy 2 Each independently is selected from any one of phenyl, naphthyl, fluorenyl, spirofluorenyl, indenyl, pyrrolyl, thienyl, furyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, quinolinyl, isoquinolinyl, benzoquinolinyl, quinoxalinyl, quinazolinyl, carbazolyl, benzimidazolyl, benzofuryl, benzothienyl, isobenzothienyl, benzimidazazolyl, benzazolyl, triazolyl, tetrazolyl, dioxolyl, triazinyl, dibenzofuryl, dibenzothienyl, N-heterocarbazolyl, N-heterodibenzofuryl, and Cy 1 and Cy 2 can optionally be connected to each other via a single bond or an organic linking group;

[0065] Between any two ligands of M, between two or more ligands, they can be connected by a single bond or a double bond, or can be bridged by O or S, or can be connected by any chemical group or chemical structure to form a structural form that conforms to chemical principles;

[0066] R 91 and R 92 Each independently is selected from -H, -D, -F, -Cl, -Br, -I, hydroxyl group, cyano group, nitro group, amino group, amidino group, hydrazino group, hydrazone group, carboxylic acid group, carboxylate group, sulfonic acid group, sulfonate group, phosphoric acid group, phosphate group, -SF 5, any one of substituted or unsubstituted C1-C60 (such as C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkyl, substituted or unsubstituted C2-C60 (such as C2, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkenyl, substituted or unsubstituted C2-C60 (such as C2, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkynyl, substituted or unsubstituted C1-C60 (such as C1, C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, C55 or C60, etc.) alkoxy, substituted or unsubstituted C2-C10 (such as C2, C3, C4, C5, C6, C7, C8, C9 or C10) heterocycloalkyl, substituted or unsubstituted C6-C60 (such as C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60, etc.) aryl, substituted or unsubstituted C6-C60 (such as C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60, etc.) aryloxy, substituted or unsubstituted C6-C60 (such as C6, C12, C15, C18, C24, C30, C32, C36, C40, C42, C54 or C60, etc.) arylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group.

[0067] a 1 and a 2 each independently is an integer selected from 1-5, such as 1, 2, 3, 4 or 5;

[0068] b is selected from integers from 0-4, such as 0, 1, 2, 3 or 4;

[0069] a is selected from 1, 2 or 3;

[0070] L 1 is a monovalent organic ligand, divalent organic ligand or trivalent organic ligand.

[0071] Preferably, the PD compound of the formula is any one of the following compounds:

[0072]

[0073]

[0074]

[0075]

[0076] In the present invention, the organic thin film layer includes a hole layer, and the hole layer includes a hole injection layer, a hole transport layer, and an electron blocking layer.

[0077] The hole injection layer material includes a P-type dopant. The P-type dopant refers to a substance that coexists with the hole injection layer material in the OLED device, can oxidize the hole injection layer material, and thus serves as an electron acceptor, which can promote the movement of holes in the hole injection layer toward the anode. In the present invention, the difference between the absolute value of the LUMO of the P-type dopant and the absolute value of the HOMO of the hole layer material is greater than -0.2 V, preferably greater than -0.1 eV, more preferably greater than 0 eV, still more preferably greater than 0.1 eV, and even more preferably greater than 0.2 eV.

[0078] The P-type dopant exists in the hole injection layer in a volume percentage of 1% to 10% (for example, it can be 1%, 2%, 4%, 6%, 8%, or 10%, etc.). In the present invention, no special limitation is imposed on the type of the P-type dopant. Exemplarily, the compounds shown as D-1 to D-13 disclosed in CN113728453A or the compounds shown as HI-1 to HI-9 described below can be selected:

[0079]

[0080] In the present invention, the hole layer material (including the hole injection layer, the hole transport layer, and the electron blocking layer) has the structure shown by the following formula HT-GH4:

[0081]

[0082] wherein, L 41 is selected from a single bond, an aryl group of C6-C40 (for example, it can be C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.), and a heteroaryl group of C6-C20 (for example, it can be C6, C8, C10, C12, C16, or C20, etc.);

[0083] Ar 41 and Ar 42 are each independently selected from an aryl group of C6-C40 (for example, it can be C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36, or C40, etc.) and a heteroaryl group of C6-C20 (for example, it can be C6, C8, C10, C12, C16, or C20, etc.);

[0084] X is selected from CR 41 R 42or NR 43 , wherein R 41 , R 42 , R 43 are each independently selected from substituted or unsubstituted phenyl (the substituents of the substituted phenyl are selected from C1-C6 (such as C1, C2, C3, C4, C5 or C6) alkyl, C1-C6 (such as C1, C2, C3, C4, C5 or C6) alkoxy, dibenzofuranyl), naphthyl, triphenylene, fluoranthenyl, 9,9-dimethylfluorenyl, biphenyl, substituted or unsubstituted dibenzofuranyl (the substituents of the substituted dibenzofuranyl are phenyl), substituted or unsubstituted dibenzothiophenyl (the substituents of the substituted dibenzothiophenyl are phenyl), dibenzofuran-substituted thiophenyl, any one of C1-C6 (such as C1, C2, C3, C4, C5 or C6) alkyl, and R 41 , R 42 can be connected into a ring through a single bond.

[0085] The compound of formula HT-GH4 is selected from any one of the following compounds:

[0086]

[0087]

[0088]

[0089] In the present invention, the hole layer material (including the hole injection layer, the hole transport layer and the electron blocking layer) further includes a compound having a structure shown in formula ⅠA or a compound having a structure shown in formula IB:

[0090]

[0091] wherein, L is selected from any one of C6-C40 (such as C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) arylene, di(dibenzofuranyl) or di(dibenzothiophenyl);

[0092] m is an integer between 0 and 4 (such as 0, 1, 2, 3 or 4), and n is selected from 0 or 1;

[0093] Ar is selected from any one of triphenylene, fluoranthene, dibenzofuranyl or dibenzothiophenyl;

[0094] Ar 1 and Ar 2Each is independently selected from any one of aryl, dibenzofuranyl or dibenzothiophenyl containing C6-C40 (such as C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.);

[0095] Ar 1 Between and Ar, Ar 2 Between and Ar, and Ar 1 Ar, 2 Between can be independently connected or bridged by a single bond, O, S, CR 1 R 2 , NR.

[0096] R, R 1 R, 2 Each is independently selected from any one of C1-C20 (such as C1, C2, C4, C6, C8, C10, C12, C14, C16, C18 or C20, etc.) alkyl, C6-C40 (such as C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl, dibenzofuranyl or dibenzothiophenyl;

[0097] H in the compound of formula IB and the compound of formula IA can each be independently replaced by at least one of -F, -CN, -D (deuterium atom), C1-C6 alkyl, C1-C6 alkoxy, phenyl, biphenyl, naphthyl, phenanthryl, anthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylene, fluoranthenyl, pyrenyl, perylenyl, spirofluorene, indenofluorene or hydrogenated benzoanthracenyl.

[0098] Preferably, the Ar is fluoranthenylidene, and m + n > 1.

[0099] Preferably, H in the compound of formula IB and the compound of formula IA can be replaced by at least one of -F, -CN, -D, C1-C3 alkyl (such as methyl, ethyl or propyl), C1-C3 alkoxy (such as methoxy, ethoxy or propoxy), phenyl, biphenyl, triphenylene, fluoranthenyl.

[0100] Preferably, the L, Ar 1 Ar, 2 Each is independently selected from at least one of phenyl, biphenyl, naphthyl, phenanthryl, anthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, triphenylene, fluoranthenyl, pyrenyl, perylenyl, spirofluorene, indenofluorene or hydrogenated benzoanthracenyl.

[0101] Preferably, the compound of formula IB is selected from the following structures:

[0102]

[0103] Among them, L is a phenylene group;

[0104] Ar 1 、Ar 2 、m have the same definitions as described above.

[0105] Preferably, the compound of Formula IB is selected from any one of the following compounds:

[0106]

[0107]

[0108] In the OLED device provided by the present invention, in addition to the compounds of Formula HT-GH4, Formula IB, and Formula IA, the hole transport layer material may simultaneously include conventional hole materials in the art without particular limitation. Exemplarily, but not limited to, triarylamine compounds or carbazole compounds. Preferably, triarylamine compounds or carbazole compounds containing more than 3 N atoms are used because the HOMO of triarylamine compounds or carbazole compounds containing more than 3 N atoms is higher (smaller absolute value), and they are more suitable as hole injection layer materials. Triarylamine compounds or carbazole compounds containing 2 or 1 N atom can be used as hole transport layer materials. Some compounds containing 1 N atom or carbazole compounds, if they have a relatively high LUMO, can also be used as electron blocking layer materials.

[0109] As the hole transport layer material, the triarylamine compound or carbazole compound has the following structure:

[0110]

[0111] Among them, Ar 601 ~Ar 609 each independently selected from substituted or unsubstituted C6-C40 (such as C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl groups, substituted or unsubstituted dibenzofuranyl groups, substituted or unsubstituted dibenzothiophenyl groups, substituted or unsubstituted naphthobenzofuranyl groups, substituted or unsubstituted naphthobenzothiophenyl groups, substituted or unsubstituted dinaphthofuranyl groups, substituted or unsubstituted dinaphthothiophenyl groups;

[0112] And Ar 601 ~Ar 609 adjacent or attached to the same N atom of Ar 601 ~Ar 609, can be connected by a single bond or through O, S, CR 701 R 702 、NR 703 bridged;

[0113] R 701 、R 702 、R 703 selected from C6-C40 (such as C6, C8, C10, C12, C16, C20, C24, C28, C30, C32, C36 or C40, etc.) aryl groups, C6-C20 (such as C6, C8, C10, C12, C16 or C20, etc.) heteroaryl groups, C1-C6 (such as C1, C2, C3, C4, C5 or C6) alkyl groups, and R 701 、R 702 can be connected by a single bond.

[0114] The hole blocking layer (HBL) can confine holes and / or excitons within the light-emitting layer range to improve the current efficiency and lifetime of the device. Compared with the light-emitting layer material closest to the HBL interface, the HBL material has a lower HOMO (larger absolute value) and / or a higher triplet energy.

[0115] The electron transport layer (ETL) can include materials capable of transporting electrons. The electron transport layer can be intrinsic (undoped) or doped, and doping can be used to enhance conductivity. In the present invention, there are no special restrictions on the ETL material, and any metal complex or organic compound can be used as long as it can transport electrons. Generally, the electron transport layer material contains at least one of the following structural fragments: pyridine structure, pyrimidine structure, triazine structure, benzimidazole structure, benzoxazole structure, benzothiazole structure, N-heteronaphthalene structure, N-heterophenanthrene structure, N-heterocarbazole structure, N-heterodibenzofuran structure, N-heterodibenzothiophene structure.

[0116] In the present invention, there are no special restrictions on the electron transport layer material, and exemplary ones include but are not limited to:

[0117]

[0118]

[0119]

[0120]

[0121]

[0122] In the present invention, the material of the cathode is a metal with a low work function (such as alkaline earth metals, alkali metals, main group metals or lanthanide elements (such as Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.)), a metal alloy composed of multiple metals (an alloy composed of an alkali metal or an alkaline earth metal and silver, such as an alloy composed of magnesium and silver), or a multi-layer structure. If the cathode material is a multi-layer structure, in addition to the metals mentioned above, other metals with a relatively high work function, such as Ag or Al, can also be used. In this case, a combination of the metals is usually used, such as Ca / Ag, Mg / Ag or Ba / Ag.

[0123] It is also possible to select a thin intermediate layer of a material with a high dielectric constant to be introduced between the metal cathode and the organic semiconductor to form a multi-layer structure; the material with a high dielectric constant can also be called an electron injection material, and fluorides of alkali metals or alkaline earth metals, as well as corresponding oxides or carbonates (such as LiF, Li 2 O, BaF 2 , MgO, NaF, CsF, Cs 2 CO 3 etc.) or lithium quinolate (LiQ) can be selected.

[0124] Compared with the prior art, the present invention has the following beneficial effects:

[0125] In the present invention, by designing the structure of quinoxaline compounds, they are suitable as the host material of the light-emitting layer of organic electroluminescent devices, making the organic electroluminescent devices have a high current efficiency, a long service life and a low driving voltage. Specific Embodiments

[0126] To facilitate the understanding of the present invention, the following examples are listed. Those skilled in the art should understand that the examples are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0127] Synthesis Example 1 Synthesis of Compound P1

[0128] This synthesis example provides compound P1 and its synthesis method, and the synthesis method is as follows:

[0129]

[0130] Under nitrogen, add 50 mL of toluene, 30 mL of ethanol, and 20 mL of water to a three-necked flask. Then add 0.01 mol of compound P1-1, 0.01 mol of compound P1-2, 2.12 g (0.02 mol) of sodium carbonate, and 0.23 g (0.0002 mol) of tetrakis(triphenylphosphine)palladium. Slowly heat the mixture to 40 °C and react for 2 hours, then heat to 60 °C and react for 2 hours, and then heat to 80 °C and react for 4 hours. Cool to room temperature, add water and separate the layers. After washing the organic layer with water, dry it with magnesium sulfate. After removing the desiccant, concentrate to dryness, and perform silica gel column chromatography separation. Elute with petroleum ether:dichloromethane = 10:1 (volume ratio) to obtain 3.8 g of compound P1.

[0131] Perform mass spectrometry detection on the obtained compound P1, and the measured mass-to-charge ratio (m / z) is 523.20.

[0132] Synthesis Example 2-4

[0133] Synthesis Example 2-4 respectively provides a compound and its synthesis method. The synthesis method of the corresponding compound refers to the preparation method of compound P1. React with raw material 1 and raw material 2 to prepare the corresponding compound, and measure the mass spectrometry of the prepared compound, record m / z, as shown in Table 1 below in detail.

[0134] Table 1

[0135]

[0136] Synthesis of Compound P5 in Synthesis Example 5

[0137] This synthesis example provides compound P5 and its synthesis method. The synthesis method is as follows:

[0138]

[0139] (1) Synthesis of Intermediate M1

[0140] Add 0.01 mol of compound P1 and 150 mL of DMF to a three-necked flask, stir until dissolved, and add 0.011 mol of NBS solid in batches at 20 - 25 °C. After adding, maintain at 20 - 25 °C for 4 hours, add water and toluene and separate the layers. After washing the organic layer with water, dry it with magnesium sulfate. After removing the desiccant, concentrate to dryness, and perform silica gel column chromatography separation. Elute with petroleum ether:dichloromethane = 10:1 (volume ratio) to obtain 4.9 g of intermediate M1.

[0141] Perform mass spectrometry detection on the obtained intermediate M1, and the measured mass-to-charge ratio (m / z) is 601.12.

[0142] (2) Synthesis of Compound P5

[0143] Under nitrogen, 80 mL of toluene, 40 mL of ethanol, and 20 mL of water were added to a three-necked flask. Then, 0.01 mol of compound M1, 0.01 mol of deuterated phenylboronic acid, 2.12 g (0.02 mol) of sodium carbonate, and 0.23 g (0.0002 mol) of tetrakis(triphenylphosphine)palladium were added thereto. The temperature was slowly raised to reflux and the reaction was carried out for 8 hours. After cooling to room temperature, water was added and liquid separation was performed. The organic layer was washed with water and dried over magnesium sulfate. After removing the desiccant, it was concentrated to dryness, and silica gel column chromatography was carried out for separation. Elution was carried out with petroleum ether:dichloromethane = 10:1 (volume ratio) to obtain 5.0 g of compound P5.

[0144] The obtained compound P5 was subjected to mass spectrometry detection, and the measured mass-to-charge ratio (m / z) was 604.27.

[0145] Synthesis Examples 6 - 8

[0146] Synthesis Examples 6 - 8 respectively provide a compound and its synthesis method. The synthesis methods of the corresponding compounds refer to the preparation method of compound P5, replacing M1 with other boric acid compounds to prepare the corresponding compounds, and measuring the mass spectrometry of the prepared compounds and recording m / z. See Table 2 in detail below.

[0147] Table 2

[0148]

[0149] Synthesis of Compound P9 in Synthesis Example 9

[0150] This synthesis example provides compound P9 and its synthesis method. The synthesis method is as follows:

[0151]

[0152] (1) Synthesis of Intermediate M2

[0153] 0.01 mol of compound P1 and 150 mL of DMF were added to a three-necked flask and stirred until dissolved. 0.022 mol of NBS solid was added portionwise at 20 - 25 °C. After addition, it was maintained at 20 - 25 °C for 6 hours. Water and toluene were added for liquid separation. The organic layer was washed with water and dried over magnesium sulfate. After removing the desiccant, it was concentrated to dryness, and silica gel column chromatography was carried out for separation. Elution was carried out with petroleum ether:dichloromethane = 10:1 (volume ratio) to obtain 5.1 g of intermediate M2.

[0154] The obtained intermediate M2 was subjected to mass spectrometry detection, and the measured mass-to-charge ratio (m / z) was 679.03.

[0155] (2) Synthesis of Compound P9

[0156] Under nitrogen, 100 mL of toluene, 60 mL of ethanol, and 30 mL of water were added to a three-necked flask. Then, 0.01 mol of intermediate M2, 0.022 mol of phenylboronic acid, 4.0 g of sodium carbonate, and 0.46 g of tetrakis(triphenylphosphine)palladium were added thereto. The temperature was slowly raised to reflux for 8 hours, cooled to room temperature, water was added for liquid separation, the organic layer was washed with water, dried over magnesium sulfate, the desiccant was removed, concentrated to dryness, and separated by silica gel column chromatography, eluting with petroleum ether:dichloromethane = 10:1 (volume ratio) to obtain 5.2 g of compound P9.

[0157] The obtained compound P9 was subjected to mass spectrometry detection, and the measured mass-to-charge ratio (m / z) was 675.27.

[0158] For compounds whose specific synthesis methods are not listed otherwise, the synthesis can be carried out by referring to the above examples and combining the common general knowledge in the art.

[0159] The specific structures of some compositions used in the following application examples and comparative application examples are as follows:

[0160]

[0161]

[0162] Application Example 1

[0163] This application example provides a blue organic electroluminescent device using the compound provided by the present invention as the host material of the light-emitting layer. The structure of the blue organic electroluminescent device is as follows:

[0164] ITO / HT-1:HI-2[5%](80 nm) / HT-1(30 nm) / Host material:PBD-1[5%](35 nm) / ETL-1(25 nm) / LiF(0.5 nm) / Al(150 nm).

[0165] The preparation method of the blue organic electroluminescent device is as follows:

[0166] The materials were placed in a vacuum chamber, evacuated to 1×10 -5 ~1×10 -6 Pa, and vacuum-evaporated onto a cleaned ITO substrate in sequence to prepare an OLED device.

[0167] Wherein PBD-1[5%] refers to the doping ratio of the dye, that is, the volume ratio of the host material to the dye PBD-1 is 95:5; HT-1:HI-2[5%] refers to the ratio of the P-type dopant, that is, the volume ratio of the hole transport material HT-1 and the P-type dopant HI-2 is 95:5. HT-1 is a hole transport material; HT-1:HI-2[5%] is used as the hole injection layer.

[0168] The host material of the light-emitting layer of the blue-light organic electroluminescent device provided in this application example is compound P1.

[0169] Application Example 2-9

[0170] Application Examples 2-9 each provide a blue-light organic electroluminescent device, which is only different from Application Example 1 in that the host material compound P1 of the light-emitting layer is replaced with other compounds (see Table 3 for details), and other preparation steps and conditions are the same as those in Application Example 1.

[0171] Comparative Application Examples 1-2

[0172] Comparative Application Examples 1-2 each provide an organic electroluminescent device, which is only different from Application Example 1 in that the host material compound P1 of the light-emitting layer is replaced with other compounds (see Table 3 for details), and other preparation steps and conditions are the same as those in Application Example 1.

[0173] Performance Test

[0174] Test the brightness, driving voltage, current efficiency, and LT95 of the organic electroluminescent devices provided above. Among them, the voltage and current efficiency are the corresponding values when the brightness is 1000 cd / m 2 The LT95 refers to the time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density while keeping the initial current density of the device at 10 mA / cm 2 unchanged. Among them, the driving voltage, current efficiency, and LT95 are relative values. The specific test results are shown in Table 3:

[0175] Table 3

[0176]

[0177] As can be seen from the above content, in the present invention, by designing the structure of the quinoxaline compound, it is suitable to be used as the host material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has a high current efficiency, a long service life, and a low driving voltage.

[0178] Application Examples 10-11

[0179] Application Examples 10-11 each provide a blue-light organic electroluminescent device, which is only different from Application Example 1 in that the host material compound P1 of the light-emitting layer is replaced with other compounds (see Table 4 for details), and other preparation steps and conditions are the same as those in Application Example 1.

[0180] Comparative Application Example 3

[0181] Comparative Application Example 3 provides an organic electroluminescent device, which is only different from Application Example 1 in that the host material compound P1 of the light-emitting layer is replaced with other compounds (see Table 4 for details), and other preparation steps and conditions are the same as those in Application Example 1.

[0182] Performance Test

[0183] Test the luminance, driving voltage, current efficiency, and LT95 of the organic electroluminescent device provided above. Among them, the voltage and current efficiency are the corresponding values when the luminance is 1000 cd / m 2 The corresponding value, and LT95 refers to the time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density while keeping the initial current density of the device at 10 mA / cm 2 unchanged. Among them, the driving voltage, current efficiency, and LT95 are relative values. The specific test results are shown in Table 4:

[0184] Table 4

[0185]

[0186] As can be seen from the above, in the present invention, by designing the structure of the quinoxaline compound, it is suitable as the host material of the light-emitting layer of the organic electroluminescent device, so that the organic electroluminescent device has a high current efficiency, a long service life, and a low driving voltage.

[0187] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the detailed process flow of the present invention, but the present invention is not limited to the above-mentioned detailed process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process flow to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A quinoxaline compound, characterized in that: The quinoxaline compound has a structure as shown in the following formula I: Wherein, Ar is selected from any one of C6-C40 aryl or C6-C30 heteroaryl; wherein Ar1, Ar2, Ar3, and Ar4 are each independently selected from any one of H, C6-C40 aryl, or C6-C30 heteroaryl, and at least one of Ar1, Ar2, and Ar4 is selected from any one of C6-C40 aryl or C6-C30 heteroaryl; R1 and R2 are each independently selected from any one of C6-C40 aryl or C6-C30 heteroaryl; m and n are each independently selected from integers between 0 and 4; The hydrogen atoms in the compound of formula I may be independently substituted by at least one of a deuterium atom, -F, -CN, a C6-C20 aryl group, a C1-C12 alkyl group or a C1-C12 alkoxy group.

2. The quinoxaline compound according to claim 1, characterized in that The C6-C40 aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, naphthylphenyl, anthracenyl, phenanthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthofluorenyl, pyrenyl, peryl, spirofluorenyl, triphenylene, fluoranthenyl, hydrogenated benzanthryl, indenofluorenyl, benzoindenofluorenyl, dibenzoindenofluorenyl, naphthofluorenyl or benzonaphthofluorenyl; The C6-C30 heteroaryl group is selected from any one of carbazolyl, dibenzofuranyl, dibenzothiophenyl, naphthobenzofuranyl, naphthobenzothiophenyl, dinaphthofuranyl, and dinaphthothiophenyl; The C6-C20 aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, fluorenyl, triphenylene, and fluoranthenyl; The C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl or decyl; The C1-C12 alkoxy group is selected from any one of methoxy, ethoxy, propoxy, butoxy, pentyloxy and hexyloxy.

3. The quinoxaline compound according to claim 1, characterized in that The Ar is selected from any one of phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthenyl, indenofluorenyl, dibenzofuranyl, dibenzothienyl, naphthobenzofuranyl or naphthobenzothienyl.

4. The quinoxaline compound according to claim 1, characterized in that Ar1, Ar2, Ar3, and Ar4 are each independently selected from any one of H, phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthenyl, indenofluorenyl, dibenzofuranyl, dibenzothienyl, naphthobenzofuranyl, or naphthobenzothienyl; Alternatively, Ar1, Ar3, and Ar4 are selected from H, and Ar2 is selected from any one of phenyl, biphenyl, dibenzofuranyl, dibenzothiophenyl, and carbazole; Alternatively, Ar1, Ar2, Ar3 are selected from H, and Ar4 is selected from any one of phenyl, biphenyl or naphthyl.

5. The quinoxaline compound according to claim 1, characterized in that The R1 and R2 are each independently selected from any one of phenyl, carbazolyl, biphenyl, fluorenyl, naphthyl, triphenylene, fluoranthenyl, indenofluorenyl, dibenzofuranyl, dibenzothienyl, naphthobenzofuranyl or naphthobenzothienyl.

6. The quinoxaline compound according to claim 1, characterized in that m=0, n=0; Or, m+n=1; Alternatively, m+n=2.

7. The quinoxaline compound according to claim 1, characterized in that The hydrogen atoms in the compound of formula I may be independently substituted by at least one of -D, -F, -CN, phenyl, naphthyl, biphenyl, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy or butoxy.

8. The quinoxaline compound according to claim 1, characterized in that The quinoxaline compound is selected from any one of the following substituted or unsubstituted compounds: The substitution means that the hydrogen atoms in the above-mentioned quinoxaline compounds can be independently replaced by deuterium atoms.

9. An intermediate, characterized in that The intermediates include the following compounds: The intermediate is used to prepare the quinoxaline compound according to any one of claims 1 to 8.

10. An organic electroluminescent device, comprising an anode, a cathode and an organic thin film layer disposed between the anode and the cathode; The organic thin film layer comprises the quinoxaline compound according to any one of claims 1 to 8.

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