A compound and use thereof

Abstract

The application provides a compound and application thereof, the compound has a structure as shown in formula I, by introducing arylamine groups, Ar3 and Ar4 on three adjacent positions of a benzene ring respectively, the size of steric hindrance is adjusted, the twist degree of the molecule is effectively controlled, the crystallinity of the molecule is reduced, meanwhile, at least one alkyl is connected to Ar1, Ar2, Ar3 and Ar4, the alkyl groups cooperate with each other, the packing density of the molecule is effectively controlled, the LUMO and HOMO energy levels are optimized, the refractive performance of the molecule is improved, and the diffusion of excitons to the hole layer is effectively blocked, so that the organic electroluminescent material with more optimal space structure and better thin film packing morphology is obtained. The compound is especially suitable for electron blocking layer materials and / or hole transport layer materials of an organic electroluminescent device, the luminous efficiency of the device can be effectively improved, the driving voltage is reduced, and the comprehensive performance of the device is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of organic electroluminescent materials, and particularly relates to a compound and application thereof. BACKGROUND

[0002] In recent years, optoelectronic devices based on organic materials have become increasingly popular, and the inherent flexibility of organic materials makes them very suitable for manufacturing on flexible substrates, allowing the design and production of beautiful and cool optoelectronic products, and obtaining incomparable advantages over inorganic materials. Such organic optoelectronic devices exemplarily include: organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, organic sensors, etc. Among them, OLEDs have developed particularly rapidly and have achieved commercial success in the field of information display. OLEDs can provide high saturation of red, green and blue colors, and full-color display devices made therefrom do not require additional backlights, and have the advantages of colorful, thin and soft.

[0003] The core of an OLED device is a thin film structure containing various organic functional materials. Common organic functional materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, light-emitting host materials, and light-emitting guest materials (dyes), etc. When powered on, electrons and holes are injected and transported to the light-emitting region and recombine there, generating excitons and emitting light.

[0004] At present, people have developed various organic materials, which, in combination with new device structures, can improve carrier mobility, regulate carrier balance, break through electroluminescent efficiency, and delay device decay. Due to quantum mechanics, common fluorescent emitters mainly utilize singlet excitons generated when electrons and holes combine to emit light, and are still widely used in various OLED products. Some metal complexes (such as iridium complexes) can utilize both triplet and singlet excitons for light emission, and are called phosphorescent emitters, which can improve energy conversion efficiency by 4 times compared to traditional fluorescent emitters. The technology of thermally activated delayed fluorescence (TADF) promotes the transition of triplet excitons to singlet excitons, and can effectively utilize triplet excitons to achieve high luminescent efficiency without using metal complexes. The technology of thermally activated sensitized fluorescence (TASF) uses materials with TADF properties to sensitize emitters through energy transfer, which also achieves high luminescent efficiency.

[0005] As OLED products gradually enter the market, people have increasingly high requirements for the performance of such products. The current OLED materials and device structures cannot completely solve the problems of OLED product efficiency, lifetime, cost, etc.

[0006] Therefore, developing more kinds of organic electroluminescent materials to improve the luminous efficiency of the device, reduce the driving voltage, and prolong the service life is an urgent problem to be solved in the field. SUMMARY

[0007] In view of the deficiencies of the prior art, the purpose of the present application is to provide a compound and its application, which is applied to OLED devices as an organic electroluminescent material, especially suitable for electron blocking layer material and / or hole transport layer material, which can improve the luminous efficiency of the device and reduce the driving voltage.

[0008] To achieve this purpose, the present application adopts the following technical solutions:

[0009] One of the purposes of the present application is to provide a compound, which has a structure as shown in Formula I:

[0010]

[0011] In Formula I, L1 and L2 are each independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group.

[0012] When L1 is a single bond, it means that Ar1 is directly connected to the N atom through a single bond (i.e., N-Ar1); when L2 is a single bond, it means that Ar2 is directly connected to the N atom through a single bond (i.e., N-Ar2). When the same description is involved below, they all have the same meaning.

[0013] In Formula I, Ar1, Ar2, Ar3, and Ar4 are each independently selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group.

[0014] In the present application, if p is 0, i.e., R1 is absent, then Ar1 is selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group; if p is 1, then Ar1 is a substituted or unsubstituted C6-C30 arylene group or a substituted or unsubstituted C3-C30 heteroarylene group; if p is 2, then Ar1 is a trivalent group containing three connecting bonds, and so on; Ar2, Ar3, and Ar4 have similar situations. For ease of expression, Ar1, Ar2, Ar3, and Ar4 are described as "any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group" in this document, and the specific valence state and number of connecting sites are adaptively changed according to the values of p, q, m, and n.

[0015] In Formula I, R1, R2, R3, and R4 are each independently selected from any one of a C2-C20 straight-chain or branched alkyl group and a C3-C20 cycloalkyl group.

[0016] R5in formula I is selected from any one of C1-C20 linear or branched alkyl, C3-C20 cycloalkyl, C2-C12 alkenyl, C2-C12 alkynyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl.

[0017] The substituents in Ar1, Ar2, Ar3, Ar4are each independently selected from at least one of methyl, halogen, C1-C10 alkoxy, C1-C10 alkylthio, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, or C3-C30 heteroaryl.

[0018] The substituents in L1, L2, R5are each independently selected from at least one of halogen, C1-C10 linear or branched alkyl, C3-C10 cycloalkyl, C2-C10 heterocycloalkyl, C1-C10 alkoxy, C1-C10 alkylthio, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, or C3-C30 heteroaryl.

[0019] In formula I, m, n, p, q are each independently an integer from 0 to the maximum allowed integer, and m, n, p, q are not simultaneously 0.

[0020] The "maximum allowed integer" is determined according to the specific type of Ar1, Ar2, Ar3, Ar4; for example, when the Ar4is phenyl, n is an integer from 0 to 5; when the Ar4is biphenyl, n is an integer from 0 to 11.

[0021] In formula I, k is an integer from 0 to 3, for example, can be 0, 1, 2, or 3.

[0022] When m, n are both 0, Ar3and Ar4are not simultaneously phenyl.

[0023] The compound provided by the present application has a structure as shown in formula I, by introducing arylamine groups, Ar3and Ar4on the three adjacent positions of the benzene ring, respectively, not only the size of the steric hindrance can be adjusted, but also the twist degree of the molecule can be effectively controlled to reduce the crystallinity of the molecule; and at least one alkyl group with ≥2 carbon atoms is introduced on Ar1, Ar2, Ar3, Ar4, the groups cooperate with each other, which can effectively control the packing density of the molecule, optimize the LUMO and HOMO energy level, improve the refractive performance of the molecule, and effectively block the diffusion of excitons to the hole layer, so as to obtain an organic electroluminescent material with more optimal spatial structure and better thin film stacking morphology, which is especially suitable for the electron blocking layer and / or the hole transport layer, improves the luminous efficiency of the device, reduces the driving voltage, and improves the comprehensive performance of the device.

[0024] It should be noted that the possible effects of each group / characteristic are described separately in the present application for the sake of convenience of explanation, but this does not mean that these groups / characteristics act in isolation. In fact, the reason for obtaining good performance is essentially the optimized combination of the whole molecule, which is the result of the synergistic effect between each group, rather than the effect of a single group.

[0025] In the present application, the halogen can be fluorine, chlorine, bromine or iodine. The same description is referred to below, which has the same meaning.

[0026] In the present application, the "substituted or unsubstituted" group can be substituted with one substituent or multiple substituents, and when the substituents are multiple (at least two), they can be the same or different substituents; the same expression is referred to below, which has the same meaning, and the selection range of the substituents is as shown above, which will not be described one by one.

[0027] In the present application, if no special description is given, the description of chemical elements contains the concept of isotopes with the same chemical properties, for example, hydrogen (H) includes 1 H (protium), 2 H (deuterium, D), 3 H (tritium, T), etc.; carbon (C) includes 12 C, 13 C, etc.

[0028] In the present application, unless otherwise specified, the heteroatom of the heteroaryl group is selected from N, O, S, P, B, Si or Se.

[0029] In the present application, the expression of the ring structure with a dash through it represents the connection site at any position on the ring structure that can form a bond.

[0030] In the present application, the expression of Ca-Cb represents that the number of carbon atoms of the group is a-b, and unless otherwise specified, in general, the number of carbon atoms does not include the number of carbon atoms of the substituents.

[0031] In the present specification, "independently of each other" means that when the subject has multiple, they can be the same or different.

[0032] In the present application, the C6-C30 can be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, etc.

[0033] The C3-C30 can be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, etc.

[0034] The C2-C20 can be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, or C19, etc.

[0035] The C3-C20 can be C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, or C19, etc.

[0036] The C1-C20 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, or C19, etc.

[0037] The C2-C12 can be C3, C4, C5, C6, C7, C8, C9, C10, or C11, etc.

[0038] The C1-C10 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, or C10.

[0039] The C2-C10 can be C2, C3, C4, C5, C6, C7, C8, C9, or C10.

[0040] In the present application, the C6-C30 aryl, preferably C6-C20 aryl, includes monocyclic aryl and fused ring aryl; the monocyclic aryl means a group containing at least one phenyl, and when containing at least two phenyls, the phenyls are connected by a single bond, and exemplarily includes but is not limited to: phenyl, biphenyl, terphenyl, etc.; the fused ring aryl means a group containing at least two aromatic rings, and the aromatic rings are fused to each other by sharing two adjacent carbon atoms, and exemplarily includes but is not limited to: naphthyl, anthryl, phenanthryl, indenyl, fluorenyl and its derivatives (9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, 9,9-dinaphthylfluorenyl, spirobifluorenyl, benzofluorenyl, etc.), fluoranthene, triphenylene, pyrene, perylene, or naphthacene, etc.

[0041] The C3-C30 heteroaryl group includes monocyclic heteroaryl groups and fused ring heteroaryl groups. The monocyclic heteroaryl group means a group having at least one heteroaryl group in the molecule, and when the molecule has one heteroaryl group and other groups (e.g., aryl group, heteroaryl group, alkyl group, etc.), the heteroaryl group and the other groups are connected by a single bond, and exemplarily includes, but is not limited to, furyl group, thienyl group, pyrrolyl group, pyridyl group, etc. The fused ring heteroaryl group means a group having at least one aromatic heterocyclic ring and one aromatic ring (aromatic heterocyclic ring or aromatic ring) in the molecule, and the two rings are fused to each other by sharing two adjacent atoms, and exemplarily includes, but is not limited to, benzofuranyl group, benzothienyl group, isobenzofuranyl group, isobenzothienyl group, indolyl group, dibenzofuranyl group, dibenzothienyl group, carbazolyl group and its derivatives (N-phenylcarbazolyl group, N-naphthylcarbazolyl group, benzocarbazolyl group, diphenylcarbazolyl group, indolocarbazolyl group, azacarbazolyl group, etc.), acridinyl group, phenothiazinyl group, phenoxazinyl group, hydroacridinyl group, etc.

[0042] Specific examples of the arylene group described below in the present application can be exemplified by bivalent groups obtained by removing one hydrogen atom from the examples of the aryl group described above. Specific examples of the heteroarylene group described below in the present application can be exemplified by bivalent groups obtained by removing one hydrogen atom from the examples of the heteroaryl group described above.

[0043] The C2-C20 straight chain or branched alkyl group exemplarily includes, but is not limited to, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, n-octyl group, n-heptyl group, n-nonyl group, n-decyl group, etc.

[0044] The C3-C20 cycloalkyl group exemplarily includes, but is not limited to, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, adamantyl group, bridged cycloalkyl group, etc.

[0045] Preferably, each of L1and L2is independently selected from any one of a single bond, a substituted or unsubstituted group described below:

[0046]

[0047] wherein the wavy line represents a bond to the group;

[0048] Preferably, each of L1and L2is independently a single bond or a phenylene group.

[0049] Preferably, each of Ar1, Ar2, Ar3, and Ar4is independently selected from any one of a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C10-C20 fused ring heteroaryl group.

[0050] Preferably, each of Ar1, Ar2, Ar3, and Ar4is independently selected from any one of a substituted or unsubstituted group described below:

[0051] Preferably, each of Ar1, Ar2, Ar3, and Ar4is independently selected from any one of a substituted or unsubstituted group described below:

[0052] wherein the wavy line represents the bond of the group to L1, L2, the phenyl ring;

[0053] X is selected from O, S, CR 11 R 12 , NR 13 or SiR 14 R 15 .

[0054] R 11 , R 12 , R 13 , R 14 , R 15 are each independently selected from any one of hydrogen, methyl, substituted or unsubstituted C2-C12 alkenyl, substituted or unsubstituted C2-C12 alkynyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl.

[0055] R 11 and R 12 are not connected or are connected by a chemical bond to form a ring, R 14 and R 15 are not connected or are connected by a chemical bond to form a ring.

[0056] Preferably, the R 11 , R 12 , R 13 , R 14 , R 15 are each independently methyl or phenyl.

[0057] Preferably, the Ar1, Ar2 are each independently selected from any one of the following substituted or unsubstituted groups:

[0058] Further preferably, the Ar1, Ar2 are each independently selected from

[0059] wherein the wavy line represents the bond of the group to L1, L2.

[0060] Preferably, the Ar3, Ar4 are each independently selected from any one of the following substituted or unsubstituted groups:

[0061]

[0062]

[0063] wherein the wavy line represents the bond of the group to the phenyl ring.

[0064] Preferably, each of R1, R2, R3, R4 is independently selected from tert-butyl or any one of the following groups:

[0065] Further preferably, each of R1, R2, R3, R4 is independently tert-butyl or

[0066] wherein the wavy line represents the connecting bond of the group.

[0067] Preferably, each of m, n, p, q is independently 0 or 1.

[0068] Preferably, p+q≥1.

[0069] Preferably, k is 0.

[0070] In the case that there is a substituent group in the aforementioned "substituted or unsubstituted" of the present application, each of the substituent groups in L1, L2 is independently selected from at least one of halogen, C1-C10 linear or branched alkyl, C3-C10 cycloalkyl, C2-C10 heterocycloalkyl, C1-C10 alkoxy, C1-C10 alkylthio, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl or C3-C30 heteroaryl, further preferably at least one of halogen, C1-C10 linear or branched alkyl, C3-C10 cycloalkyl, C2-C10 heterocycloalkyl, C6-C30 aryl or C3-C30 heteroaryl. Each of the substituent groups in Ar1, Ar2, Ar3, Ar4 is independently selected from at least one of methyl, halogen, C1-C10 alkoxy, C1-C10 alkylthio, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl or C3-C30 heteroaryl.

[0071] Preferably, the compound has any one of the structures shown in P1-P501 below:

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105] The second object of the present application is to provide a compound as described in any one of the preceding objects for use in an organic electroluminescent device.

[0106] Preferably, the compound is used as an electron blocking material and / or a hole transporting material in the organic electroluminescent device.

[0107] The compound of the present application can significantly improve the luminous efficiency of the device and reduce the driving voltage, and make the device have better comprehensive performance as an electron blocking layer material and / or a hole transporting layer material of the organic electroluminescent device, more preferably for green light electron blocking layer material.

[0108] The compound as an electron blocking layer material can improve the current efficiency of the organic electroluminescent device, reduce the driving voltage, and make the device performance improve by more than 15% compared with the prior art.

[0109] In addition to the organic electroluminescent device, the compound of the present application can also be applied to other types of organic electronic devices, such as organic field effect transistors, organic thin film solar cells, information labels, electronic artificial skin sheets, sheet type scanners or electronic paper.

[0110] The third object of the present application is to provide an organic electroluminescent device, which comprises a first electrode, a second electrode and at least one organic layer disposed between the first electrode and the second electrode; the organic layer comprises at least one compound as described in any one of the preceding objects.

[0111] Preferably, the organic layer comprises an electron blocking layer, and the electron blocking layer comprises at least one compound as described in any one of the preceding objects.

[0112] Preferably, the organic layer comprises a hole transporting layer, and the hole transporting layer comprises at least one compound as described in any one of the preceding objects.

[0113] In a specific technical solution, the organic electroluminescent device comprises a substrate, an anode layer, a plurality of light-emitting functional layers and a cathode layer formed in sequence on the substrate; the light-emitting functional layer comprises at least one of a hole injection layer, a hole transporting layer, a light-emitting layer, an electron blocking layer and an electron transporting layer; wherein the electron blocking layer and / or the hole transporting layer contains at least one compound as described in any one of the preceding objects; preferably, the electron blocking layer contains at least one compound as described in any one of the preceding objects.

[0114] In a specific technical solution, the organic electroluminescent device (OLED) comprises a first electrode and a second electrode, and an organic layer between the first electrode and the second electrode. The organic layer can be divided into multiple regions, such as a hole transporting region, a light-emitting layer and an electron transporting region.

[0115] In the specific embodiments, a substrate can be used under the first electrode or on the second electrode. The substrates are all glass or polymer materials with excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, the substrates for displays can also have thin film transistors (TFTs) thereon.

[0116] The first electrode can be formed by sputtering or depositing a material used as the first electrode on the substrate. When the first electrode is used as an anode, indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (Sn02), zinc oxide (ZnO), and other oxide transparent conductive materials, and any combination thereof can be used. When the first electrode is used as a cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and any combination thereof can be used.

[0117] The organic layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, and the like. The compounds used as the organic layer can be organic small molecules, organic macromolecules, or polymers, and combinations thereof.

[0118] The hole transport zone is located between the anode and the light-emitting layer. The hole transport zone can be a single-layer structure of a hole transport layer (HTL), including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport zone can also be a multi-layer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL); the HIL is located between the anode and the HTL, and the EBL is located between the HTL and the light-emitting layer; the HTL and / or the EBL contain at least one compound having the structure of Formula I; preferably, the EBL contains at least one compound having the structure of Formula I.

[0119] The materials of the hole transport zone can also be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene vinylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphor sulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives, wherein the aromatic amine derivatives include the compounds shown in HT-1 to HT-51 below; or any combination thereof.

[0120]

[0121]

[0122]

[0123] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can employ one or more of the compounds described above as HT-1 to HT-51, or one or more of the compounds described below as HI-1 to HI-3; or one or more of the compounds described above as HT-1 to HT-51 doped with one or more of the compounds described below as HI-1 to HI-3.

[0124]

[0125] The light emitting layer includes light emitting dyes (dopants) that can emit different wavelengths of light spectrum, and can also include host materials. The light emitting layer can be a single color light emitting layer that emits a single color such as red, green, blue, etc. Multiple single color light emitting layers of different colors can be arranged in a planar pattern according to a pixel pattern, or can be stacked together to form a color light emitting layer. When the light emitting layers of different colors are stacked together, they can be separated from each other or connected to each other. The light emitting layer can also be a single color light emitting layer that can emit different colors such as red, green, blue, etc. at the same time.

[0126] Depending on the technology, the light emitting layer material can employ different materials such as fluorescent electroluminescent materials, phosphorescent electroluminescent materials, thermally activated delayed fluorescent light emitting materials, etc. In an OLED device, a single light emitting technology can be employed, or a combination of multiple different light emitting technologies can be employed. These different light emitting materials classified by technology can emit the same color of light, or can emit different colors of light.

[0127] In an aspect of the present application, the light emitting layer employs a fluorescent electroluminescent technology. The fluorescent host material of the light emitting layer can be selected from, but not limited to, a combination of one or more of the following listed BFH-1 to BFH-17.

[0128]

[0129] In an aspect of the present application, the light emitting layer employs a fluorescent electroluminescent technology. The fluorescent dopant of the light emitting layer can be selected from, but not limited to, a combination of one or more of the following listed BFD-1 to BFD-24.

[0130]

[0131]

[0132] In an aspect of the present application, the light emitting layer employs a phosphorescent electroluminescent technology. The host material of the light emitting layer is selected from, but not limited to, a combination of one or more of PH-1 to PH-85.

[0133]

[0134]

[0135]

[0136]

[0137] In an aspect of the application, the light-emitting layer employs phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, a combination of one or more of the following listed GPD-1 to GPD-47.

[0138]

[0139]

[0140]

[0141] In an aspect of the application, the light-emitting layer employs phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, a combination of one or more of the following listed RPD-1 to RPD-28.

[0142]

[0143]

[0144] In an aspect of the application, the light-emitting layer employs phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, a combination of one or more of the following listed YPD-1 to YPD-11.

[0145]

[0146] The OLED organic layer can also include an electron transport zone between the light-emitting layer and the cathode. The electron transport zone can be an electron transport layer (ETL) of a single layer structure, including a single layer electron transport layer containing only one compound and a single layer electron transport layer containing multiple compounds. The electron transport zone can also be a multi-layer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0147] In an aspect of the application, the electron transport layer material can be selected from, but not limited to, a combination of one or more of the following listed ET-1 to ET-73.

[0148]

[0149]

[0150]

[0151]

[0152] In one aspect of the present invention, a hole-blocking layer (HBL) is positioned between the electron-transporting layer and the light-emitting layer. The hole-blocking layer may be composed of, but is not limited to, one or more of the compounds ET-1 to ET-73 described above, or one or more of the compounds PH-1 to PH-46, or a mixture of, but not limited to, one or more of the compounds ET-1 to ET-73 and one or more of the compounds PH-1 to PH-46.

[0153] The device may further include an electron injection layer located between the electron transport layer and the cathode. The electron injection layer material includes, but is not limited to, one or more combinations of the following: LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Yb, Li, Ca or Mg.

[0154] Compared with the prior art, the present invention has the following beneficial effects:

[0155] The novel compound of the structure shown in a kind of formula I provided by the present invention, by respectively introducing aromatic amine group, Ar3 and Ar4 at three sites adjacent to the benzene ring, not only can the size of steric hindrance be adjusted, but also the degree of distortion of the molecule can be effectively regulated to reduce the crystallinity of the molecule;At the same time, at least one alkyl group is connected to Ar1, Ar2, Ar3 and Ar4, and the groups cooperate with each other, which can effectively regulate the packing density of the molecule, optimize the LUMO and HOMO energy levels, improve the refractive properties of the molecule, and effectively block the diffusion of excitons to the hole layer, thereby obtaining an organic electroluminescent material with a better spatial structure and a better thin film stacking morphology. The compound is particularly suitable as an electron blocking layer material and / or a hole transport layer material of an organic electroluminescent device, can improve the luminous efficiency of the device, reduce the driving voltage, and improve the comprehensive performance of the device.

[0156] The preparation process of the compound is simple and easy, the raw materials are readily available, and the compound is suitable for mass production and expansion. DETAILED DESCRIPTION

[0157] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0158] In the present invention, a representative synthesis route of the compound having the structure shown in Formula I is as follows:

[0159]

[0160] wherein L1, L2, Ar1, Ar2, Ar3, Ar4, R1, R2, R3, R4, R5, m, n, p, q, and k have the same meanings as in Formula I; Pd(PPh3)4 represents tetrakistriphenylphosphine palladium, Pd2(dba)3 represents tris(dibenzylacetone)dipalladium(0), Sphos represents 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, IPr.HCl represents 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride, NaOBu-t represents sodium tert-butoxide, and (t-Bu)3P represents tri-tert-butylphosphine.

[0161] The preparation of the compound of formula I of the present invention includes the above-mentioned method, but is not limited to the above-mentioned method. Compounds of formula I synthesized by those skilled in the art using other methods also fall within the scope of protection of the present invention.

[0162] More specifically, the following synthesis examples of the present invention provide exemplary methods for synthesizing the compounds. The solvents and reagents used in the following synthesis examples can be purchased or customized from the chemical product market. In addition, those skilled in the art can also synthesize by other known methods.

[0163] The mass spectrometry data in the following synthesis examples were obtained by using a ZAB-HS mass spectrometer manufactured by Micromass, UK.

[0164] Synthesis Example 1: Synthesis of Compound P5

[0165]

[0166] (1) In a 1000 mL single-necked bottle, add 15 g of M1, 16.8 g of 2-biphenylboronic acid, 0.8 g of tetrakistriphenylphosphine palladium Pd(PPh3)4, 20 g of potassium carbonate, 300 mL of 1,4-dioxane, and 100 mL of water. Vacuum and replace with nitrogen three times. Heat the reaction to 90°C for 5 h. After the reaction is complete, stop the reaction. Cool to room temperature, separate the reaction solution, and purify the organic phase twice with a silica gel column. Concentrate the organic phase, add methanol, reflux and stir for 1 h, filter to obtain a light yellow powder M1-1, and then recrystallize from ethyl acetate to obtain the pure product.

[0167] (2) In a 1000 mL three-necked flask, 18.6 g of M1-1, 12.4 g of 2-naphthaleneboronic acid, 0.5 g of tris(dibenzylideneacetone)dipalladium(0) Pd2(dba)3, 0.5 g of 2-bis(cyclohexylphosphino)-2',6'-dimethoxybiphenyl (Sphos), 17 g of anhydrous potassium phosphate, 300 mL of 1,4-dioxane and 30 mL of water were added, vacuum-nitrogen substitution was performed for 3 times, the reaction was heated to 110°C for 5 h. After the reaction was completed, the reaction was stopped. After being cooled to room temperature, the reaction solution was separated, the organic phase was purified by silica gel column twice, the organic phase was concentrated, methanol was added, reflux stirring was performed for 1 h, and light yellow powder M1-2 was obtained by filtration, and then the pure product was obtained by recrystallization with ethyl acetate.

[0168] (3) In a 1000 mL three-necked flask, 17.3 g of M1-2, 2 mL of hydrazine hydrate, 0.5 g of palladium on carbon (Pd / C) and 300 mL of ethanol were added, vacuum-nitrogen substitution was performed for 3 times, the reaction was heated to 90°C for 5 h. After the reaction was completed, the reaction was stopped. After being cooled to room temperature, the reaction solution was separated, the organic phase was purified by silica gel column twice, the organic phase was concentrated, methanol was added, reflux stirring was performed for 1 h, and white powder M1-3 was obtained by filtration, and then the pure product was obtained by recrystallization with ethyl acetate.

[0169] (4) In a 1000 mL single-necked flask, 14.7 g of M1-3, 9.4 g of 4-bromobiphenyl, 0.5 g of Pd2(dba)3, 0.5 g of 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride (IPr.HCl), 500 mL of toluene and 14.5 g of sodium tert-butoxide (NaOBu-t) were added, vacuum-nitrogen substitution was performed for 3 times, the reaction was heated to 90°C for 5 h. After the reaction was completed, the reaction was stopped. After being cooled to room temperature, the reaction solution was separated, the organic phase was purified by silica gel column twice, the organic phase was concentrated, methanol was added, reflux stirring was performed for 1 h, and light yellow powder M1-4 was obtained by filtration, and then the pure product was obtained by recrystallization with ethyl acetate.

[0170] (5) In a 1000 mL three-necked flask, 16.5 g of M1-4, 8.2 g of 4-bromo-tert-butylbenzene, 0.5 g of Pd2(dba)3, 0.5 mL of tri-tert-butylphosphine (t-Bu)3P, 500 mL of toluene and 14.5 g of sodium tert-butoxide were added, vacuum-nitrogen substitution was performed for 3 times, the reaction was heated to 110°C for 5 h. After the reaction was completed, the reaction was stopped. After being cooled to room temperature, the reaction solution was separated, the organic phase was purified by silica gel column twice, the organic phase was concentrated, methanol was added, reflux stirring was performed for 1 h, and light yellow powder P5 was obtained by filtration, and then the pure product was obtained by recrystallization with ethyl acetate for three times.

[0171] Compound P5: m / z theoretical value: 655; m / z measured value: 656.

[0172] Synthesis Example 2: Synthesis of compound P100

[0173]

[0174] The difference between the synthesis method and synthesis example 1 is only that 2-naphthalene boronic acid in step (2) is replaced by phenyl boronic acid, and 4-bromo-4'-tert-butylbiphenyl in step (5) is replaced by 4-bromo-4'-tert-butylbiphenyl.

[0175] Compound P100: m / z theoretical value: 681; m / z observed value: 682.

[0176] Synthesis Example 3: Synthesis of compound P133

[0177]

[0178] The difference between the synthesis method and synthesis example 1 is only that 2-naphthalene boronic acid in step (2) is replaced by phenyl boronic acid, and 4-bromo-4'-tert-butylbiphenyl in step (5) is replaced by 4-bromo-4'-tert-butylbiphenyl.

[0179] Compound P133: m / z theoretical value: 663; m / z observed value: 664.

[0180] Synthesis Example 4: Synthesis of compound P169

[0181]

[0182] The difference between the synthesis method and synthesis example 2 is only that 4-bromobiphenyl in step (4) is replaced by 4-bromo-4'-tert-butylbiphenyl.

[0183] Compound P169: m / z theoretical value: 661; m / z observed value: 662.

[0184] Synthesis Example 5: Synthesis of compound P202

[0185]

[0186] The difference between the synthesis method and synthesis example 4 is only that 4-bromo-4'-tert-butylbiphenyl in step (5) is replaced by 4-adamantylbromobenzene.

[0187] Compound P202: m / z theoretical value: 663; m / z observed value: 664.

[0188] Synthesis Example 6: Synthesis of compound P287

[0189]

[0190] The difference between the synthesis method and synthesis example 1 is only that 2-naphthalene boronic acid in step (2) is replaced by phenyl boronic acid, and 4-bromo-4'-tert-butylbiphenyl in step (5) is replaced by 4-bromo-4'-tert-butylbiphenyl.

[0191] Compound P287: m / z calculated value: 735; m / z found value: 736.

[0192] Synthesis Example 7: Synthesis of Compound P294

[0193]

[0194]

[0195] The only difference between the synthesis method and that of Synthesis Example 1 is that the 2-biphenylboric acid in step (1) is replaced by 9,9-dimethylfluorene-4-boric acid, and the 2-naphthaleneboric acid in step (2) is replaced by 4-tert-butylphenylboric acid.

[0196] Compound P294: m / z calculated value: 701; m / z found value: 702.

[0197] Synthesis Example 8: Synthesis of Compound P400

[0198]

[0199] The synthesis method thereof differs from that of Synthesis Example 1 only in that: 2-biphenylboric acid in step (1) is replaced by 9,9-dimethylfluorene-4-boric acid, 2-naphthaleneboric acid in step (2) is replaced by phenylboric acid, 4-bromobiphenyl in step (4) is replaced by 2 times the molar amount of 4-bromo-4'-tert-butylbiphenyl, and step (5) is not performed.

[0200] Compound P400: m / z calculated value: 777; m / z found value: 778.

[0201] Synthesis Example 9: Synthesis of Compound P433

[0202]

[0203] The only difference between the synthesis method and that of Synthesis Example 4 is that 4-bromo-4'-tert-butylbiphenyl in step (5) is replaced by 2-bromo-9,9-dimethylfluorene.

[0204] Compound P433: m / z calculated value: 645; m / z found value: 646.

[0205] Synthesis Example 10: Synthesis of Compound P466

[0206]

[0207] The difference between the synthesis method and synthesis example 1 is only that 2-biphenyl boronic acid in step (1) is replaced by 9,9-dimethylfluorene-4-boronic acid, 2-naphthalene boronic acid in step (2) is replaced by phenyl boronic acid, 4-bromobiphenyl in step (4) is replaced by 4-bromo-tert-butylbenzene, and 4-bromo-tert-butylbenzene in step (5) is replaced by 2-bromo-9,9-dimethylfluorene.

[0208] Compound P466: m / z theoretical value: 685; m / z observed value: 686.

[0209] Synthesis example 11: synthesis of compound P474

[0210]

[0211] The difference between the synthesis method and synthesis example 1 is only that 2-biphenyl boronic acid in step (1) is replaced by 9,9-dimethylfluorene-4-boronic acid, 2-naphthalene boronic acid in step (2) is replaced by phenyl boronic acid, 4-bromobiphenyl in step (4) is replaced by 4-bromo-tert-butylbenzene, and 4-bromo-tert-butylbenzene in step (5) is replaced by 2-bromo-9,9-dimethylfluorene.

[0212] Compound P474: m / z theoretical value: 685; m / z observed value: 686.

[0213] Example 1

[0214] An organic electroluminescent device comprising an anode (ITO), a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a cathode (Al) arranged in sequence; its preparation method is as follows:

[0215] (1) The glass plate coated with ITO transparent conductive layer (as anode) is ultrasonically treated in commercial cleaning agent, washed in deionized water, ultrasonically degreased in mixed solvent of acetone / ethanol, baked in clean environment until completely removing water, washed with ultraviolet light and ozone, and the surface is bombarded with low-energy cation beam;

[0216] (2) The glass substrate with anode is placed in a vacuum chamber, vacuumized to <1x10 -5 Pa, a mixture of compound HT-4:HI-3 (97 / 3, w / w) is vacuum thermal evaporated on the anode layer film as a hole injection layer in the order, the evaporation rate is 0.1 nm / s, and the evaporation film thickness is 10 nm;

[0217] (3) HT-4 is vacuum evaporated on the hole injection layer as a hole transport layer of the device, the evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 60 nm;

[0218] (4) Vacuum deposition of the compound P5 provided by the present application as the electron blocking layer of the device on the hole transport layer, the deposition rate is 0.1 nm / s, and the total film thickness of the deposition is 40 nm;

[0219] (5) Vacuum deposition of the light-emitting layer of the device on the hole transport layer, the light-emitting layer comprising a host material and a dye material, a ternary mixture of the host materials PH-61:PH-3:GPD-12 (100:100:20, w / w / w) is used as the light-emitting layer by the method of multi-source co-deposition; the deposition rate is 0.1 nm / s, and the total film thickness of the deposition is 40 nm;

[0220] (6) Vacuum deposition of the electron transport layer material ET-69:ET-57 (50 / 50, w / w) mixture on the light-emitting layer, the deposition rate is 0.1 nm / s, and the total film thickness of the deposition is 25 nm;

[0221] (7) Vacuum deposition of LiF with a thickness of 0.5 nm as the electron injection layer on the electron transport layer (ETL), and deposition of aluminum metal with a thickness of 150 nm as the cathode of the device, to obtain the organic electroluminescent device.

[0222] Examples 2-11 and Comparative Examples 1-4

[0223] An organic electroluminescent device, which is only different from Example 1 in that the electron blocking layer material compound P5 in step (4) is replaced by the compound in Table 1.

[0224] The structures of the electron blocking layer materials of Comparative Examples 1-4 are as follows:

[0225]

[0226] The sources of Comparative Compounds R1, R2 can be referred to the prior art CN110373183A; R3 can be referred to the prior art CN108976132A; and R4 can be referred to the prior art CN109485577A.

[0227] The organic electroluminescent devices provided by the above Examples 1-11 and Comparative Examples 1-4 are tested for the following performances: the voltage is raised at a rate of 0.1 V per second, and when the brightness of the organic electroluminescent device reaches 10000 cd / m 2 , the voltage at this time is measured as the driving voltage, and the current density at this time is also measured; the ratio of the brightness to the current density is the current efficiency; and the test results are shown in Table 1.

[0228] Table 1

[0229]

[0230]

[0231] As can be seen from the data in Table 1, when the compound of the present application is used as an electron blocking layer material for an organic electroluminescent device, the brightness of the device reaches 10000 cd / m 2 When the brightness of the device reaches 10000 cd / m

[0232] Compared with the compounds in the prior art (Comparative Examples 1-4), the compound of the present application can obtain a more optimal space structure by sequentially introducing an arylamine group, Ar3 and Ar4 on three adjacent positions in the benzene ring, and at least one alkyl group on the aryl group of the arylamine unit, the aryl group of Ar3 and the aryl group of Ar4 (preferably an alkyl group on the aryl group of the arylamine unit), and each group cooperates with each other, so that the molecule has a more optimal arrangement when the thin film is stacked, thereby further improving the luminous efficiency of the device, which is at least 15% higher than the prior art compounds, and changing any one of the aforementioned groups will reduce the luminous efficiency.

[0233] The applicant declares that the present application is illustrated by the above examples, but the present application is not limited to the above examples, that is, it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific modes, etc. fall within the protection scope and disclosure scope of the present application.

Claims

1. A compound, characterized in that The compound has a structure as shown in Formula I: Wherein, L1 and L2 are each independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; Ar1, Ar2, Ar3 are selected from any one of the following substituted or unsubstituted groups: Among them, the wavy lines represent the bonds between the group and L1, L2, and the benzene ring; X is selected from CR 11 R 12 NR 13 or SiR 14 R 15 ; R 11 、R 12 、R 13 、R 14 、R 15 Each is independently selected from any one of hydrogen, methyl, substituted or unsubstituted C2-C12 alkenyl, substituted or unsubstituted C2-C12 alkynyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; R 11 and R 12 Not connected or connected to form a ring through chemical bonds, R 14 and R 15 Not connected or connected to form a ring through chemical bonds; Ar4 is selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group; R1, R2, R3, and R4 are each independently selected from any one of a C2-C20 straight or branched alkyl group and a C3-C20 cycloalkyl group; R5 is selected from any one of C1-C20 straight or branched alkyl, C3-C20 cycloalkyl, C2-C12 alkenyl, C2-C12 alkynyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; The substituents substituted in Ar1, Ar2, Ar3, and Ar4 are each independently selected from at least one of methyl, halogen, C1-C10 alkoxy, C1-C10 alkylthio, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, or C3-C30 heteroaryl; The substituents in L1, L2, and R5 are each independently selected from at least one of halogen, C1-C10 straight or branched alkyl, C3-C10 cycloalkyl, C2-C10 heterocycloalkyl, C1-C10 alkoxy, C1-C10 alkylthio, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, or C3-C30 heteroaryl; m, n, p, q are each independently 0 to the maximum allowed integer, and m, n, p, q are not 0 at the same time; k is an integer from 0 to 3; When m and n are both 0, Ar3 and Ar4 are not phenyl groups at the same time.

2. The compound according to claim 1, characterized in that The L1 and L2 are each independently selected from a single bond, a substituted or unsubstituted group, or any one of the following groups: The wavy lines represent the bonds connecting the groups.

3. The compound according to claim 2, characterized in that The L1 and L2 are each independently a single bond or a phenylene group.

4. The compound according to claim 1, characterized in that The Ar4 is selected from any one of a substituted or unsubstituted C6-C20 aryl group and a substituted or unsubstituted C10-C20 fused ring heteroaryl group.

5. The compound according to claim 4, characterized in that The Ar4 is selected from any one of the following substituted or unsubstituted groups: Among them, the wavy lines represent the bonds between the group and L1, L2, and the benzene ring; X is selected from O, S, CR 11 R 12 NR 13 or SiR 14 R 15 ; R 11 、R 12 、R 13 、R 14 、R 15 Each is independently selected from any one of hydrogen, methyl, substituted or unsubstituted C2-C12 alkenyl, substituted or unsubstituted C2-C12 alkynyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; R 11 and R 12 Not connected or connected to form a ring through chemical bonds, R 14 and R 15 Not connected or connected to form a ring through chemical bonds.

6. The compound according to claim 1 or 5, characterized in that The R 11 、R 12 、R 13 、R 14 、R 15 Each is independently a methyl group or a phenyl group.

7. The compound according to claim 1, characterized in that The Ar1 and Ar2 are each independently selected from any one of the following substituted or unsubstituted groups: The wavy lines represent the bonds between the groups and L1 and L2.

8. The compound according to claim 1, characterized in that The Ar3 is selected from any one of the following substituted or unsubstituted groups: The Ar4 is selected from any one of the following substituted or unsubstituted groups: The wavy line represents the bond between the group and the benzene ring.

9. The compound according to claim 1, characterized in that The R1, R2, R3, and R4 are each independently selected from a tert-butyl group or any one of the following groups: The wavy lines represent the bonds connecting the groups.

10. The compound according to claim 1, characterized in that The m, n, p, and q are each independently 0 or 1.

11. The compound according to claim 1, characterized in that Said p+q≥1.

12. The compound according to claim 1, characterized in that The k is 0.

13. The compound according to claim 1, characterized in that The compound has any one of the structures shown in P1-P501 below:

14. Use of the compound according to claim 1, characterized in that: The compound is applied to organic electroluminescent devices.

15. The use according to claim 14, characterized in that The compound serves as an electron blocking material and / or a hole transport material in an organic electroluminescent device.

16. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode, and at least one organic layer disposed between the first electrode and the second electrode; the organic layer comprises at least one compound according to claim 1.

17. The organic electroluminescent device according to claim 16, characterized in that: The organic layer includes an electron blocking layer, and the electron blocking layer includes at least one compound according to claim 1.

18. The organic electroluminescent device according to claim 16, characterized in that: The organic layer includes a hole transport layer, and the hole transport layer includes at least one compound according to claim 1.

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