Dibenzofuran derivative, application thereof and organic electroluminescent device

Abstract

The invention provides a dibenzofuran derivative, application thereof and an organic electroluminescent device, the dibenzofuran derivative has a structure as shown in a formula I or a formula II, and through the design of a molecular structure, the dibenzofuran derivative has excellent carrier transport rate and energy transfer efficiency, proper HOMO and LUMO energy levels and excellent electron injection and transport capabilities, and can be used for preparing the organic electroluminescent device. And the compound has a specific spatial configuration and higher light extraction efficiency and thermal stability. The dibenzofuran derivative is excellent in photoelectric property, is used for the organic electroluminescent device, and can effectively improve the luminous efficiency of the device, reduce the driving voltage and prolong the service life, so that the device has better comprehensive performance.

Description

Technical Field

[0001] The invention belongs to the technical field of organic light-emitting materials, and specifically relates to a dibenzofuran derivative and application thereof, and an organic electroluminescent device. Background Art

[0002] In recent years, optoelectronic devices based on organic materials have developed rapidly and become a hot technology in the field. Examples of organic optoelectronic devices 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. OLED devices can provide highly saturated red, green, and blue colors. Full-color display devices made of them do not require additional backlight sources and have the advantages of bright colors, lightness, thinness, and softness.

[0003] The core of OLED devices is a multi-layer thin film structure containing a variety of 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, luminescent host materials and luminescent guest (dyes), etc. When the OLED device is powered on, electrons and holes are injected and transported to the luminescent area respectively and recombine there, thereby generating excitons and emitting light.

[0004] OLED devices can be divided into fluorescent luminescence, phosphorescent luminescence, thermally excited delayed fluorescence and thermally excited sensitized fluorescence according to the luminescence mechanism. Common fluorescent luminescent bodies mainly use 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 use triplet excitons and singlet excitons to emit light at the same time, which are called phosphorescent luminescent bodies. Their energy conversion efficiency can be increased by up to four times that of traditional fluorescent luminescent bodies. Thermally excited delayed fluorescence (TADF) technology can effectively utilize triplet excitons to achieve higher luminescence efficiency without using metal complexes by promoting the transformation of triplet excitons to singlet excitons. Thermally excited sensitized fluorescence (TASF) technology uses materials with TADF properties to sensitize the luminescent body through energy transfer, which can achieve higher luminescence efficiency.

[0005] Although products using OLED display technology have been commercialized, the device's lifespan, efficiency and other performance still need to be continuously improved to meet people's pursuit of higher display quality. Therefore, the field is in urgent need of developing more types of higher-performance organic materials, which can be applied to organic electroluminescent devices to make the devices have better effects in terms of luminous efficiency, voltage, lifespan and other aspects. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a dibenzofuran derivative and its application, and an organic electroluminescent device. Through the design of the molecular structure of the compound, the dibenzofuran derivative has excellent photoelectric properties. It is applied to organic electroluminescent devices, especially suitable for the main material of the light-emitting layer, so that the device has higher luminous efficiency, longer service life and lower driving voltage.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a dibenzofuran derivative having a structure as shown in Formula I or Formula II:

[0009]

[0010]

[0011] In Formula I and Formula II, L1 and L2 are each independently selected from any one of a single bond, a substituted or unsubstituted C6-C60 arylene group, and a substituted or unsubstituted C3-C60 heteroarylene group; when L1 is a single bond, it represents that the six-membered ring where X1 is located is directly connected to the naphthyl group through a single bond; when L2 is a single bond, it represents that the benzofuran derivative group is directly connected to the naphthyl group through a single bond.

[0012] In Formula I and Formula II, X1, X2, X3, X4, and X5 are each independently selected from CR A or N, and at least one of them is N; it should be noted that multiple (2, 3, 4) CR A R A are the same or different groups.

[0013] R A Each is independently selected from any one of hydrogen, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl.

[0014] In Formula I and Formula II, R1, R2, R3, and R4 each independently represent unsubstituted, monosubstituted, or polysubstituted; when representing unsubstituted, that is, R1, R2, R3, and R4 are hydrogen; when representing polysubstituted (e.g., disubstituted, trisubstituted), multiple substituents (e.g., multiple R1) are the same or different groups; the same applies to R2, R3, and R4, and for the sake of brevity, they are not described one by one.

[0015] R1, R2, R3, and R4 are each independently selected from any one of hydrogen, halogen, cyano, substituted or unsubstituted C1-C30 straight or branched alkyl, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C3-C30 cycloalkyl, C1-C30 alkoxy, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl.

[0016] L1, L2, R A , R1, R2, R3, and R4, the substituted substituents are each independently selected from any one of halogen, cyano, nitro, hydroxyl, amino, aldehyde, ester, C1-C30 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C1-C30 alkoxy, C2-C20 heterocycloalkyl, C6-C60 aryl, and C3-C60 heteroaryl, or a combination of at least two thereof; the substituted substituents are each independently not connected to the adjacent ring structure or are connected to form a ring through chemical bonds.

[0017] In the present invention, "the substituted substituents are each independently not connected to the adjacent ring structure" means that the substituent is only connected to the C atom through a single bond; "the substituted substituents are each independently connected to the adjacent ring structure through a chemical bond to form a ring" means that the substituent is connected to the C atom through a chemical bond and is also connected to the adjacent ring through a chemical bond, thereby forming a fused ring structure. When the same description is involved below, it has the same meaning and will not be repeated one by one.

[0018] In the present invention, the "substituted or unsubstituted" group may be substituted with one substituent or with multiple substituents. When there are multiple substituents (at least 2), they may be the same or different substituents. When the same expressions are mentioned below, they have the same meaning. Unless otherwise specified, the selection range of the substituted substituents is as shown above and will not be repeated.

[0019] The dibenzofuran derivatives provided by the present invention have a molecular structure shown in Formula I or Formula II, and have the following structural characteristics and technical effects:

[0020] (1) The compound contains a naphthyl bridge structure The naphthyl 1-position is substituted with a benzodibenzofuran substituent, and the naphthyl 3-position is substituted with a nitrogen-containing heterocyclic substituent to form a large conjugated structure. The 3-position of the naphthyl is substituted with a nitrogen-containing heterocyclic substituent to form a good coplanar with naphthalene, effectively enhancing the injection and transmission capabilities of electrons, and forming an electron injection transmission channel. At the same time, the benzodibenzofuran substituent itself has a low triplet energy level, which is conducive to the triplet energy level distribution in the excited state. After the naphthyl 1-position is substituted, a certain angle is formed with the naphthyl, causing configuration deflection, so that the triplet energy level distribution of the dibenzofuran derivative provided by the present invention is effectively separated from the electron transmission channel. In the excited state, the energy transfer process is carried out by the vibration transfer of the triplet distribution group, without affecting the configuration change of the electron transmission channel and the decrease in the carrier transmission rate caused by it, so that the dibenzofuran derivative is applied to the organic electroluminescent device, the energy transfer efficiency can be improved, and the purpose of improving efficiency is achieved.

[0021] (2) The introduction of a dibenzofuran fused ring and a nitrogen-containing heterocyclic ring at the 1 and 3 positions of the naphthyl bridge is helpful to adjust the dipole moment of the molecule and the HOMO energy level and LUMO energy level of the compound, thereby improving the electron injection and transmission capabilities of the dibenzofuran derivative. When used in an organic electroluminescent device, it can achieve the purpose of reducing the device voltage.

[0022] (3) Due to the double substitution at the 1-position and 3-position of the naphthyl bridge, the stacking radius of the entire molecule is larger, which helps to make the molecules more regularly arranged when prepared into a solid film. The dibenzofuran derivative is applied to an organic electroluminescent device, which can effectively improve the light extraction efficiency, thereby improving the overall luminous efficiency of the device.

[0023] (4) Compounds containing The fused ring structure is characterized in that the side of the ring connected to the naphthyl bridge is the "inside", and the dibenzofuran is phenyl-fused on the outside of the molecule, which can reduce the ratio of n-π* transitions due to the lone pair of electrons of the oxygen atom in the triplet state, thereby increasing the inter-gap crossing rate and the life span of the triplet exciton. At the same time, the molecular weight of the dibenzofuran derivative is at a reasonable value, which can not only increase the glass transition temperature (Tg) of the material, but also will not cause the evaporation temperature to be too high to affect the thermal stability of the material, so that the dibenzofuran derivative can be applied to the organic electroluminescent device to achieve a long life.

[0024] Therefore, the dibenzofuran derivatives provided by the present invention have excellent carrier transfer rate and energy transfer efficiency, suitable HOMO and LUMO energy levels, excellent electron injection and transmission capabilities, and have specific spatial configurations, higher light extraction efficiency and thermal stability through the design of molecular structure. The dibenzofuran derivatives have excellent photoelectric properties, and when used in organic electroluminescent devices, they can effectively improve the luminous efficiency and life of the device and reduce the driving voltage of the device.

[0025] It should be noted that, for the sake of convenience, the possible effects of each group / feature are described separately in the present invention, but this does not mean that these groups / features act in isolation. In fact, the reason for obtaining good performance is essentially the optimized combination of the entire molecular structure, which is the result of the synergistic effect of each group, rather than the effect of a single group.

[0026] In the present invention, the halogen may be fluorine, chlorine, bromine or iodine. The following descriptions involving the same have the same meaning.

[0027] In the present invention, the expression of chemical elements, unless otherwise specified, includes the concept of isotopes with the same chemical properties. For example, hydrogen (H) includes 1 H (hydrogen), 2 H (deuterium, D), 3 H (tritium, T), etc.; carbon (C) includes 12 C. 13 C, etc.

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

[0029] In the present invention, the expression of a ring structure crossed by “—” indicates that the connection site is at any position on the ring structure that can form a bond.

[0030] In the present invention, "*" indicates the attachment point of the group.

[0031] In the present invention, the expression of Ca-Cb means that the number of carbon atoms in the group is ab. Unless otherwise specified, the number of carbon atoms does not include the number of carbon atoms in the substituent.

[0032] In the present invention, “each independently” means that when there are multiple subjects, they may be the same as or different from each other.

[0033] In the present invention, the C6-C60 can be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, ​​C48, C50, C52, C54, C56 or C58, etc.

[0034] The C3-C60 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, ​​C48, C50, C52, C54, C56 or C58, etc.

[0035] The C1-C30 can all be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C20, C22, C24, C26 or C28, etc.

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

[0037] The C3-C30 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, etc.

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

[0039] The C3-C20 can all be C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0040] The C2-C20 can all be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0041] In the present invention, the C1-C30 straight chain or branched alkyl group, preferably a C1-C20 straight chain or branched alkyl group, further preferably a C1-C10 straight chain or branched alkyl group, illustratively includes but is not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-methylbutyl, n-pentyl, isopentyl, neopentyl, n-hexyl, neohexyl, 2-ethylhexyl, n-octyl, n-heptyl, n-nonyl, n-decyl, etc.

[0042] Specific examples of the C1-C30 alkoxy group include monovalent groups obtained by connecting the above-mentioned linear or branched alkyl groups to O.

[0043] The C3-C30 cycloalkyl, preferably C3-C20 cycloalkyl, further preferably C3-C10 cycloalkyl, includes monocyclic alkyl or polycyclic alkyl. Wherein, monocyclic alkyl refers to an alkyl containing a single cyclic structure, and polycyclic alkyl refers to a structure composed of two or more cycloalkyl groups sharing one or more carbon atoms on the ring; exemplary examples include but are not limited to: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, etc.

[0044] Specific examples of the C2-C20 heterocycloalkyl group include groups formed by replacing at least one C atom in the aforementioned cycloalkyl group with a heteroatom (such as N, O, S, etc.), including but not limited to: epoxy, oxetanyl, tetrahydrofuranyl, tetrahydrothiophenyl, tetrahydropyrrolyl, tetrahydropyranyl, piperidinyl, piperazinyl, dioxane, morpholinyl, etc.

[0045] The C2-C20 alkenyl, preferably C2-C10 alkenyl, contains at least one C=C, illustratively including but not limited to: vinyl, propenyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, butadienyl, pentadienyl and the like.

[0046] The C6-C60 aromatic group is preferably a C6-C30 aromatic group, and more preferably a C6-C20 aromatic group, including a monocyclic aromatic group and a condensed-ring aromatic group; the monocyclic aromatic group means that the group contains at least one phenyl group, and when it contains at least two phenyl groups, the phenyl groups are connected by a single bond, and illustratively include but are not limited to: phenyl, biphenyl, terphenyl, quaterphenyl, etc.; specifically, the biphenyl group includes 2-biphenyl, 3-biphenyl, and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, and m-terphenyl-2-yl. The fused ring aromatic group refers to a group containing at least two aromatic rings, and the aromatic rings share two adjacent carbon atoms and are fused to each other, including, but not limited to, naphthyl (1-naphthyl, 2-naphthyl), anthracenyl (1-anthracenyl, 2-anthracenyl, 9-anthracenyl), phenanthrenyl, indenyl, fluorenyl (1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, 9-fluorenyl) and derivatives thereof (9 ,9-dimethylfluorenyl, 9,9-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dibutylfluorenyl, 9,9-dipentylfluorenyl, 9,9-dihexylfluorenyl, 9,9-diphenylfluorenyl, 9,9-dinaphthylfluorenyl, phenylmethylfluorenyl, spirobifluorenyl, benzofluorenyl, etc.), fluoranthenyl, triphenylene, pyrenyl (1-pyrenyl, 2-pyrenyl, 4-pyrenyl), peryl, It should be noted that the monocyclic aromatic group and the condensed aromatic group connected by a single bond also belong to the scope of aromatic group, such as phenylnaphthyl, naphthylphenyl, etc.

[0047] The C3-C60 heteroaryl group is preferably a C3-C30 heteroaryl group, and more preferably a C3-C20 heteroaryl group, including a monocyclic heteroaryl group or a condensed ring heteroaryl group. The monocyclic heteroaryl group means that the molecule contains at least one heteroaryl group. When the molecule contains a heteroaryl group and other groups (such as aryl, heteroaryl, etc.), the heteroaryl group and the other groups are connected by a single bond, and exemplary examples include but are not limited to: pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, furanyl, thienyl, pyrrolyl, bipyridyl, phenylpyridyl, pyridylphenyl, pyrimidinylphenyl, etc. The fused ring heteroaryl group means a group containing at least one aromatic heterocycle and one aromatic ring (aromatic heterocycle or aromatic ring) in the molecule, and the two share two adjacent atoms that are fused to each other, including, but not limited to, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, isobenzothiophenyl, indolyl, dibenzofuranyl, dibenzothiophenyl, naphthiobenzofuranyl, naphthiobenzothiophenyl, carbazolyl and its derivatives (N-phenylcarbazolyl, N-naphthylcarbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolcarbazolyl, azacarbazolyl, etc.), acridinyl, phenothiazinyl, phenoxazinyl, hydroacridinyl, etc.

[0048] Preferably, L1 and L2 are each independently selected from any one of a single bond, a substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) arylene group, and a substituted or unsubstituted C3-C20 (e.g., C3, C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) heteroarylene group.

[0049] Preferably, L1 and L2 are each independently selected from any one of the following groups which are single bonds, substituted or unsubstituted:

[0050] Wherein, -* represents the attachment site of the group.

[0051] Z1 is selected from O, S, CR 11 R 12 or NR 13 Any one of .

[0052] R 11 , R 12 , R 13 Each is independently selected from any one or a combination of at least two of C1-C30 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl; the R 11 and R 12 Not connected or connected to form a ring through chemical bonds.

[0053] Preferably, Z1 is selected from O, S or CR 11 R 12 Any one of .

[0054] Preferably, the R 11 , R 12 Each is independently selected from any one of C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight chain or branched alkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16 or C18, etc.) aryl, and further preferably any one of C1-C6 straight chain or branched alkyl, phenyl, naphthyl, biphenyl.

[0055] Preferably, the substituents substituted in L1 and L2 are each independently selected from any one or a combination of at least two of halogen, cyano, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight chain or branched alkyl, C3-C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16 or C18, etc.) aryl, C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16 or C18, etc.) heteroaryl, and more preferably any one of C1-C6 straight chain or branched alkyl, phenyl, naphthyl, biphenyl, pyridyl and pyrimidyl.

[0056] Preferably, L1 and L2 are each independently selected from a single bond or any one of the following groups:

[0057] Wherein, -* represents the attachment site of the group.

[0058] Preferably, L1 and L2 are single bonds.

[0059] Preferably, the dibenzofuran derivative has a structure as shown in Formula I-1 or Formula II-1:

[0060]

[0061] Among them, X1, X2, X3, X4, X5, R1, R2, R3, and R4 have the same limited ranges as those in the aforementioned Formula I and Formula II.

[0062] As a preferred technical solution of the present invention, the dibenzofuran derivative has a structure as shown in Formula I-1 or Formula II-1, wherein the 1 and 3 positions of the naphthyl bridge are directly connected to the dibenzofuran condensed ring and the nitrogen-containing heterocyclic ring by a single bond, respectively, and the 1-position of the naphthyl is connected to the benzene ring on one side of the dibenzofuran condensed ring. The nitrogen-containing heterocyclic ring is directly connected to the 3-position of the naphthyl by a single bond, and the coplanar electronegativity formed with the naphthyl is stronger, so that the electron cloud on the naphthyl is attracted to the nitrogen-containing heterocyclic ring outside the molecular structure, which is beneficial to the injection of electrons, and is also beneficial to improving the electron transmission capacity during the solid-state stacking process; the 1-position of the naphthyl is directly connected to the benzene ring on one side of the dibenzofuran condensed ring by a single bond, so that the separation degree of the HOMO distribution and the LUMO distribution in the compound molecule is reduced, and the TADF (thermally activated delayed fluorescence) effect of the compound of the present invention is avoided, resulting in the loss of triplet excitons, thereby affecting the efficiency and life of the OLED device.

[0063] Preferably, the number of N in X1, X2, X3, X4 and X5 is 1-3, for example, 1, 2, or 3; thus, the group in the dibenzofuran derivative is It may be a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted pyridazinyl group, or a substituted or unsubstituted triazinyl group.

[0064] Preferably, at least one of X1, X3 and X5 is N.

[0065] Preferably, X1, X3 and X5 are all N, and X2 and X4 are each independently selected from CR A ; Thus, the group is a substituted or unsubstituted triazine group.

[0066] Preferably, the R A Each is independently selected from any one of hydrogen, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl.

[0067] Preferably, the R A Each is independently selected from hydrogen, substituted or unsubstituted any one of the following groups:

[0068] Wherein, -* represents the attachment site of the group.

[0069] Z2 and Z3 are each independently selected from O, S, CR 21 R 22 or NR 23 Any one of .

[0070] R 21 , R 22, R 23 Each is independently selected from any one or a combination of at least two of C1-C30 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl; the R 21 and R 22 Not connected or connected to form a ring through chemical bonds.

[0071] R 31 , R 32 Each is independently selected from any one or a combination of at least two of hydrogen, halogen, cyano, C1-C30 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C1-C30 alkoxy, C6-C30 aryl, and C3-C30 heteroaryl.

[0072] R A The substituted substituents are each independently selected from any one or a combination of at least two of halogen, cyano, C1-C30 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C1-C30 alkoxy, C6-C30 aryl, and C3-C30 heteroaryl; the substituted substituents are each independently not connected to the adjacent ring structure or are connected to form a ring through chemical bonds.

[0073] Preferably, Z2 and Z3 are each independently selected from O, S or CR 21 R 22 Any one of .

[0074] Preferably, the R 21 , R 22 Each is independently selected from any one of C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight chain or branched alkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16 or C18, etc.) aryl, and further preferably any one of C1-C6 straight chain or branched alkyl, phenyl, naphthyl, biphenyl.

[0075] Preferably, the R 21 and R 22 Not connected, connected to form a ring through a single bond, or connected to form a ring through an ether bond.

[0076] Preferably, the R 31 , R 32 Each is independently selected from any one of hydrogen, halogen, cyano, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight chain or branched alkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16 or C18, etc.) aryl, and phenyl is more preferred.

[0077] Preferably, R A The substituents substituted in the above-mentioned substitution are each independently selected from halogen, cyano, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight or branched alkyl, C2-C10 (e.g., C3, C4, C5, C6, C7, C8, C9, etc.) alkenyl, C3-C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C6-C20 (e.g., C6, C9, C10, C7, C8, C9, etc.) Any one of C1-C30 (for example, C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, C20, C22, C25, C28, etc.) heteroaryl, and any one of halogen, cyano, C1-C6 straight or branched alkyl, cyclohexyl, phenyl, naphthyl, biphenyl, pyridyl, and pyrimidyl is further preferred.

[0078] Preferably, R A The substituted substituents are each independently not connected to the adjacent ring structure or are connected by chemical bonds to form a ring Cy, wherein the ring Cy is selected from any one of a substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aromatic ring, a substituted or unsubstituted C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) heteroaromatic ring, and more preferably In any of the above, the dotted line represents the fusion site of the group.

[0079] Preferably, the R A Each is independently selected from hydrogen or any one of the following groups:

[0080]

[0081] Wherein, -* represents the attachment site of the group.

[0082] Preferably, R1, R2, R3, and R4 are each independently selected from any one of hydrogen, halogen, cyano, substituted or unsubstituted C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) linear or branched alkyl, substituted or unsubstituted C3-C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, substituted or unsubstituted C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, or C18, etc.) aryl, and substituted or unsubstituted C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16, or C18, etc.) heteroaryl.

[0083] Preferably, the substituents substituted in R1, R2, R3 and R4 are each independently selected from any one or a combination of at least two of halogen, cyano, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight or branched alkyl, C3-C10 cycloalkyl (e.g., C4, C5, C6, C7, C8, C9, etc.), C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16 or C18, etc.) aryl, C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) heteroaryl.

[0084] Preferably, R1, R2, R3, and R4 are each independently selected from hydrogen, halogen, unsubstituted or halogenated C1-C6 straight or branched alkyl, cyclohexyl, Any one of the following; -* represents the attachment site of the group.

[0085] Preferably, the dibenzofuran derivative has a structure shown in any one of the following A1-A232:

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097] In a second aspect, the present invention provides a use of the dibenzofuran derivative as described in the first aspect, wherein the dibenzofuran derivative is used in an organic electronic device.

[0098] Preferably, the organic electronic device includes an organic electroluminescent device, an optical sensor, a solar cell, a lighting element, an organic thin film transistor, an organic field effect transistor, an organic thin film solar cell, an information tag, an electronic artificial skin sheet, a sheet-type scanner or electronic paper.

[0099] Preferably, the dibenzofuran derivative is applied to an organic electroluminescent device, and more preferably applied to a red organic electroluminescent device.

[0100] Preferably, the dibenzofuran derivative is used as a light-emitting layer material in an organic electroluminescent device, and more preferably as a red light host material.

[0101] In a third aspect, the present invention provides an organic electroluminescent device, comprising 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 dibenzofuran derivative as described in the first aspect.

[0102] Preferably, the organic layer comprises at least one dibenzofuran derivative having a structure represented by A1-A232.

[0103] Preferably, the organic layer comprises a light-emitting layer, and the light-emitting layer comprises at least one dibenzofuran derivative as described in the first aspect.

[0104] Preferably, the light-emitting layer comprises a host material and a doping material, and the host material comprises at least one dibenzofuran derivative as described in the first aspect; further preferably, the host material comprises at least one dibenzofuran derivative having a structure shown in A1-A232.

[0105] Preferably, the doping material (also called "dye", "luminescent dye", "guest material") is a phosphorescent doping material.

[0106] Preferably, the organic layer further includes a hole transport region and an electron transport region.

[0107] Preferably, the hole transport region includes any one of a hole injection layer, a hole transport layer, and an electron blocking layer, or a combination of at least two of them.

[0108] Preferably, the electron transport region includes any one of an electron injection layer, an electron transport layer, and a hole blocking layer, or a combination of at least two of them.

[0109] In a preferred technical solution, the organic electroluminescent device (OLED device) comprises a first electrode, a second electrode, and an organic layer located between the electrodes. The organic layer can be divided into multiple regions, for example, a hole transport region, a light-emitting layer, and an electron transport region; the light-emitting layer comprises at least one dibenzofuran derivative as described in the first aspect, and further preferably comprises at least one dibenzofuran derivative having a structure shown in A1-A228.

[0110] In a preferred technical solution, the organic electroluminescent device includes a substrate, and a first electrode, a plurality of light-emitting functional layers (organic layers) and a second electrode sequentially arranged on the substrate; the organic layer includes a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer and an electron injection layer sequentially arranged, and the hole injection layer is in contact with the first electrode (anode). The organic layer (preferably the light-emitting layer) contains at least one dibenzofuran derivative as described in the first aspect, and further preferably contains at least one dibenzofuran derivative having a structure shown in A1-A232.

[0111] In a preferred technical solution, a substrate can be used below the first electrode or above the second electrode. The substrate is glass or polymer material with excellent mechanical strength, thermal stability, water resistance and transparency. In addition, a thin film transistor (TFT) can also be provided on the substrate used as a display.

[0112] The first electrode can be formed by sputtering or depositing the material used as the first electrode on the substrate. When the first electrode is used as an anode, an oxide transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as a cathode, a metal or alloy 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.

[0113] The organic layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, etc. The compound used as the organic layer can be an organic small molecule, an organic macromolecule or a polymer, and a combination thereof.

[0114] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a single-layer 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 region can also be a multilayer structure including at least one layer of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL); wherein the HIL is located between the anode and the HTL, and the EBL is located between the HTL and the light-emitting layer.

[0115] The material of the hole transport region can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic 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.

[0116]

[0117]

[0118]

[0119]

[0120] 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 use one or more compounds of HT-1 to HT-51 above, or one or more compounds of HI-1 to HI-3 below; or one or more compounds of HT-1 to HT-51 can be doped with one or more compounds of HI-1 to HI-3 below.

[0121]

[0122] The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit different wavelength spectra and a host material (Host). The light-emitting layer can be a monochrome light-emitting layer that emits a single color such as red, green, and blue. A plurality of monochrome light-emitting layers of different colors can be arranged in a plane according to a pixel pattern, or they can be stacked together to form a color light-emitting layer. When 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 simultaneously emit different colors such as red, green, and blue.

[0123] According to different technologies, the light-emitting layer material can be made of different materials such as fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescent materials. In an OLED device, a single light-emitting technology can be used, or a combination of multiple different light-emitting technologies can be used. These different light-emitting materials classified by technology can emit light of the same color or different colors.

[0124] Specifically, the host material in the light-emitting layer may include a single host compound or two host compounds, and the light-emitting dye in the light-emitting layer may include one type of dye compound or two types of dye compounds. When two host compounds are included, the energy level relationship and carrier transport performance of the two compounds can be matched, designed and selected according to requirements. When two types of dye compounds are included, the light-emitting wavelengths of the two compounds and the energy level relationship with the host material can be matched, designed and selected according to requirements.

[0125] In one aspect of the present invention, the host material of the light-emitting layer adopts the dibenzofuran derivative of the present invention.

[0126] In the present invention, the main material of the light-emitting layer can only use the dibenzofuran derivative of the present invention as a single light-emitting main material. In addition, the light-emitting layer can also adopt a technical solution of multiple light-emitting main materials and / or multiple light-emitting dyes. When multiple light-emitting main bodies are used, the light-emitting main material may include a first compound and a second compound, and the first compound uses at least one dibenzofuran derivative having a structure shown in Formula I or Formula II of the present invention, or a compound having a structure shown in at least one of A1-A232 as described above. The second compound can be selected to match the energy level relationship, carrier transport performance, etc. of the first compound.

[0127] The second compound may include one or more combinations of the following PH-1 to PH-85, but is not limited to one or more combinations of the following PH-1 to PH-85.

[0128]

[0129]

[0130]

[0131]

[0132] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0133]

[0134]

[0135] Where D is deuterium.

[0136] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0137]

[0138]

[0139] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0140]

[0141] In one aspect of the present invention, an electron blocking layer (EBL) is located between the hole transport layer and the light emitting layer. The electron blocking layer may be one or more compounds of HT-1 to HT-51, but is not limited thereto.

[0142] The OLED organic layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region may also be a multi-layer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0143] In one aspect of the present invention, the electron transport layer material can be selected from, but not limited to, one or more combinations of ET-1 to ET-73 listed below.

[0144]

[0145]

[0146]

[0147]

[0148] In one aspect of the present invention, a hole blocking layer (HBL) is located between the electron transport layer and the light emitting layer. The hole blocking layer may be one or more compounds of the above ET-1 to ET-73, but is not limited thereto.

[0149] The device may also 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, Li, Ca, Mg, and Yb.

[0150] In a fourth aspect, the present invention provides a display device, comprising the organic electroluminescent device as described in the third aspect.

[0151] Preferably, the display device includes a display screen or a display panel.

[0152] The present invention also provides an electronic device, which includes the above-mentioned display device.

[0153] Compared with the prior art, the present invention has the following beneficial effects:

[0154] The dibenzofuran derivative provided by the present invention has a structure shown in Formula I or Formula II, and through the design of the molecular structure, it has excellent carrier transfer rate and energy transfer efficiency, suitable HOMO and LUMO energy levels, excellent electron injection and transmission capabilities, and has a specific spatial configuration, higher light extraction efficiency and thermal stability. The dibenzofuran derivative has excellent photoelectric properties, and when used in an organic electroluminescent device, it can effectively improve the luminous efficiency of the device, reduce the driving voltage, extend the service life, and make the device have better comprehensive performance. DETAILED DESCRIPTION

[0155] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0156] The dibenzofuran derivatives of Formula I or Formula II of the present invention can be synthesized by known organic synthesis methods. An exemplary synthesis route is given below, but those skilled in the art can also obtain them by other known methods.

[0157] In one embodiment, the dibenzofuran derivative has a structure shown in Formula II and can be prepared by the representative synthetic route shown below:

[0158]

[0159]

[0160] Wherein, L1, L2, X1, X2, X3, X4, X5, R1, R2, and R4 have the same defined ranges as in Formula II; M1 and M2 are each independently selected from any one of I, Br, Cl or OTf (trifluoromethanesulfonate).

[0161] In a specific embodiment, for intermediate 1, when L2 is not a single bond, it can be prepared by the following synthetic route:

[0162] in,

[0163] M3 is selected from any one of I, Br, Cl or OTf.

[0164] In one embodiment, the dibenzofuran derivative has a structure shown in Formula I, and its representative synthetic route is similar to the above-mentioned route, except that the intermediate 1 is replaced by That's it.

[0165] The specific preparation method of the dibenzofuran derivatives of the present invention will be described in detail below using multiple synthesis examples as examples. However, the preparation method of the dibenzofuran derivatives of the structure shown in Formula I or Formula II of the present invention includes but is not limited to the synthesis method in the specific embodiment. Those skilled in the art can also make routine adjustments to the preparation method according to actual needs. The dibenzofuran derivatives of the structure shown in Formula I or Formula II synthesized by other methods also belong to the protection scope of the present invention.

[0166] The following synthesis examples of the present invention provide specific synthesis methods of representative compounds by way of example. The solvents and reagents used in the synthesis examples can all be purchased or customized from the chemical product market. The mass spectrometry characterization data (MS) of the intermediates and target compounds in the present invention were obtained by testing using a ZAB-HS mass spectrometer (manufactured by Micromass, UK).

[0167] The compounds of the synthesis methods not mentioned in the present invention are all raw materials obtained from commercial channels, or are prepared by themselves according to known methods using these raw materials.

[0168] Synthesis Example 1: Synthesis of Compound A1

[0169]

[0170] S1 (2-bromo-benzo[B]naphtho[2,3-D]furan, 30 g), S2 (p-chlorophenylboronic acid, 16 g), potassium carbonate (28 g) were added to a three-necked flask, and solvent dioxane (300 mL) and water (50 mL) were added. Then, after nitrogen replacement, tetrakis(triphenylphosphine)palladium (Pd(PPh3)4, 1.17 g) was added, and the temperature was raised to reflux for overnight reaction. After the reaction was completed, the solvent was concentrated, and dichloromethane DCM was added to dissolve and extract, and the organic phase was collected and purified and separated by silica gel column to obtain A1-1 (29.3 g) as a white solid.

[0171] Under nitrogen protection, A1-1 (29.3 g), pinacol diboron (34 g), potassium acetate (26.2 g) were dissolved in dioxane (300 mL), tris(dibenzylideneacetone)dipalladium (Pd2(dba)3, 1.7 g) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (1.6 g) were added, and heated to reflux for 7 h under nitrogen protection. After concentration, it was dissolved in DCM and purified by silica gel column chromatography to obtain A1-2 (30 g) as a white solid.

[0172] In a three-necked flask, add A1-2 (30 g), S3 (1-bromo-3-chloronaphthalene, 17 g), potassium carbonate (20 g) into a single-necked flask, then add solvent dioxane (250 mL) and water (40 mL), add tetra-Pd(PPh3)4 (0.85 g) after nitrogen replacement, heat to 105°C and reflux for 6 hours. A large amount of solid precipitates in the system, which is filtered after cooling, rinsed with water and ethanol, and dried to obtain A1-3 (27 g) as a light yellow solid.

[0173] A1-3 (27 g), biboronic acid pinacol ester (22.6 g), potassium acetate (17.5 g) were added to a three-necked flask, and 250 mL of dioxane solvent was added. Then, after nitrogen replacement, palladium acetate (Pd(OAc)2, 0.26 g) and 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (0.82 g) were added, and the temperature was raised to reflux for overnight reaction. After the reaction was completed, the solvent was filtered and concentrated, dissolved in DCM, and purified by silica gel column to obtain A1-4 (24.6 g) as a white solid.

[0174] A1-4 (24.6 g), S4 (2-chloro-4,6-diphenyl-1,3,5-triazine, 12 g), potassium carbonate (12.4 g), Pd(PPh3)4 (0.55 g), 200 mL of dioxane and 30 mL of water were added to a 500 mL three-necked flask, and then the nitrogen was replaced by vacuum three times, and the temperature was raised to 106°C, and the reaction was allowed to proceed overnight. After the reaction was completed, the heating was stopped, and the mixture was cooled to room temperature and filtered. The filtered solid was purified by silica gel column chromatography, and the obtained crude product was recrystallized from xylene to obtain a white solid as the target product A1 (15 g). M / Z theoretical value: 651.234; measured value: 652.2 (M+1).

[0175] Synthesis example 2-18

[0176] The following dibenzofuran derivatives were prepared by a synthetic method similar to that of preparing A1, except that S1, S2, and S4 were replaced by compounds in equimolar amounts as shown in Table 1; if S2 is "-", it means that S1 is directly reacted with biboric acid pinacol ester to prepare intermediate 2 in a representative synthetic route (corresponding to A1-2 in Synthesis Example 1):

[0177] Table 1

[0178]

[0179]

[0180]

[0181] The present invention exemplifies the specific synthesis methods of the above compounds. For dibenzofuran derivatives for which no specific synthesis method is given in the following examples, they are also prepared by similar methods, which can be obtained by simply replacing the raw materials. They will not be described in detail here, or those skilled in the art can also prepare them by other methods in the prior art.

[0182] Example 1

[0183] An organic electroluminescent device comprises 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. The preparation method of the organic electroluminescent device is as follows:

[0184] (1) a glass substrate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone / ethanol mixed solvent, baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0185] (2) Place the glass substrate with the anode in a vacuum chamber and evacuate the chamber to a vacuum of less than 1×10 -5 Pa, vacuum evaporating a mixture of compound HT-4:HI-2 (97 / 3, w / w) on the above anode layer as a hole injection layer, the evaporation rate is 0.1 nm / s, and the evaporation film thickness is 10 nm;

[0186] (3) vacuum evaporating compound HT-4 on the hole injection layer as a hole transport layer, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 60 nm;

[0187] (4) vacuum evaporating compound HT-47 on the hole transport layer as an electron blocking layer, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 5 nm;

[0188] (5) Vacuum evaporation of the main material on the electron blocking layer: RPD-7 (100 / 3, w / w) binary mixture as the light-emitting layer, the main material is the dibenzofuran derivative A1 provided by the present invention, the evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 40 nm;

[0189] (6) vacuum evaporating compound ET-17 on the light-emitting layer as a hole blocking layer, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 5 nm;

[0190] (7) vacuum evaporating a mixture of compounds ET-69:ET-57 (50 / 50, w / w) on the hole blocking layer as an electron transport layer, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 25 nm;

[0191] (8) Vacuum evaporation of LiF as an electron injection layer on the electron transport layer at a rate of 0.1 nm / s and a thickness of 1 nm;

[0192] (9) Vacuum evaporating metal Al with a thickness of 150 nm on the electron injection layer as a cathode at a evaporation rate of 1 nm / s to obtain the organic electroluminescent device.

[0193] Examples 2-22, Comparative Examples 1-7

[0194] An organic electroluminescent device, which differs from Example 1 only in that the main materials of the light-emitting layer are the compounds shown in Table 2; other layers, thicknesses, materials and preparation methods are the same as those in Example 1.

[0195] The structure of the main material in the above comparative example is as follows:

[0196]

[0197] Among them, the synthesis methods of compounds CP1, CP2 and CP7 are detailed in the prior art KR20200074723A, the synthesis methods of compounds CP3 and CP4 are detailed in the prior art WO2017074052A1, the synthesis method of compound CP5 is detailed in the prior art WO2021230655A1, and the synthesis method of compound CP6 is detailed in the prior art WO2020153733A1.

[0198] The performance test of the organic electroluminescent devices provided in Examples 1-22 and Comparative Examples 1-7 was carried out in the following specific methods:

[0199] At the same brightness, the driving voltage, current efficiency and device life of each organic electroluminescent device were measured. Specifically, the voltage was increased at a rate of 0.1 V per second, and the brightness of the organic electroluminescent device was measured when it reached 3000 cd / m 2 The voltage at which the light is on is the driving voltage, and the current density at this time is measured at the same time; the ratio of brightness to current density is the current efficiency; the life test of LT97 is as follows: use a brightness meter at 10000cd / m 2 At the same brightness, the current is kept constant and the brightness of the organic electroluminescent device is measured to drop to 9700cd / m 2 The time in hours.

[0200] The test values ​​of voltage, current efficiency and life of comparative example 1 are recorded as 1, and the ratios of the test values ​​of voltage, current efficiency and life of other devices to the test values ​​of voltage, current efficiency and life of comparative example 1 (relative voltage, relative current efficiency and relative life) are calculated. The specific results are shown in Table 2.

[0201] Table 2

[0202]

[0203]

[0204] Combined with the data in Table 2, it can be seen that the dibenzofuran derivatives provided by the present invention have excellent photoelectric properties. As the main material of the light-emitting layer of an organic electroluminescent device, it can make the device have higher luminous efficiency, longer life and lower driving voltage.

[0205] Compared with the device prepared by using the prior art compound CP1-CP76 as the main body of the light-emitting layer, the dibenzofuran derivative of the present invention is used as the main material of the light-emitting layer, which significantly improves the luminous efficiency and life of the device, and reduces the voltage. The reasons are speculated as follows: Comparative Examples 1-7 respectively use the compounds CP1-CP7 in the prior art. The triazine groups in CP1 and CP7 are bridged with the naphthyl group at the 1-position. The triazine groups are flipped at a large angle in the configuration, resulting in poor molecular electron injection and transmission capabilities. At the same time, naphthodibenzofuran is connected to the second position of the naphthyl group to enhance the hole capacity of the material, further weakening the transmission of electrons. When it is used as the main material of the light-emitting layer, the carrier transmission is unbalanced, and the exciton composite interface deviates from the light-emitting layer, so the device performance is worse. In CP2, the naphthodibenzofuran group and the triazine group are bridged at the 2 and 6 positions of the naphthyl group, respectively, which makes the Tg of the compound too high and the rigidity too strong. When preparing thin film devices, the molecules are easy to crystallize, and electron scattering is more likely to occur under high electric fields, causing efficiency roll-off and shortened life. Secondly, the naphthyl benzofuran in CP3 and CP4 is bridged with the triazine group through the 1,2 and 2,3 positions of the naphthyl, respectively, so that the steric hindrance of the molecule is very large, the molecular stacking is not good, which is not conducive to the transmission of carriers and energy transfer, and easily leads to the generation of polarons, which seriously affects the device performance. In addition, the phenanthrenyl benzofuran group used in CP5 has a triplet energy level that is too low compared to the dibenzofuran derivatives of the present invention. When preparing the red light host material in the light-emitting layer of OLED, it is easy to cause the guest energy to be transferred back to the host, resulting in worse device performance. Compared with the dibenzofuran derivatives of the present invention, the triazine-substituted naphthyl in CP6 is connected to the naphthalene outer benzene ring of naphthyl benzofuran at the 1-position, so that the lone pair of electrons in the furan oxygen atom is delocalized, and the ratio of n-π* transition after molecular excitation is increased, so that the inter-gap crossing rate from the singlet state S1 to the triplet state T1 is reduced, thereby weakening the energy transfer efficiency and causing T1 exciton accumulation, which makes the overall device performance worse.

[0206] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the dibenzofuran derivatives and their applications and the organic electroluminescent device of the present invention, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A dibenzofuran derivative, characterized in that: The dibenzofuran derivative has a structure as shown in Formula I or Formula II: Wherein, L1 and L2 are each independently selected from any one of a single bond, a substituted or unsubstituted C6-C60 arylene group, and a substituted or unsubstituted C3-C60 heteroarylene group; X1, X2, X3, X4, and X5 are each independently selected from CR A or any one of N, and at least one of them is N; R A Each is independently selected from any one of hydrogen, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl; R1, R2, R3, and R4 each independently represent unsubstituted, monosubstituted, or polysubstituted, and each independently selected from any one of hydrogen, halogen, cyano, substituted or unsubstituted C1-C30 straight or branched alkyl, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C3-C30 cycloalkyl, C1-C30 alkoxy, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl; L1, L2, R A , R1, R2, R3, and R4, the substituted substituents are each independently selected from any one of halogen, cyano, nitro, hydroxyl, amino, aldehyde, ester, C1-C30 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C1-C30 alkoxy, C2-C20 heterocycloalkyl, C6-C60 aryl, and C3-C60 heteroaryl, or a combination of at least two thereof; the substituted substituents are each independently not connected to the adjacent ring structure or are connected to form a ring through chemical bonds.

2. The dibenzofuran derivative according to claim 1, characterized in that The L1 and L2 are each independently selected from any one of a single bond, a substituted or unsubstituted C6-C20 arylene group, and a substituted or unsubstituted C3-C20 heteroarylene group; Preferably, L1 and L2 are each independently selected from any one of the following groups which are single bonds, substituted or unsubstituted: Wherein, -* represents the attachment site of the group; Z1 is selected from O, S, CR 11 R 12 or NR 13 Any of the following: R 11 , R 12 , R 13 Each is independently selected from any one or a combination of at least two of C1-C30 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl; the R 11 and R 12 Not connected or connected into rings by chemical bonds; Preferably, the substituents in L1 and L2 are each independently selected from any one or a combination of at least two of halogen, cyano, C1-C10 straight or branched alkyl, C3-C10 cycloalkyl, C6-C20 aryl, and C3-C20 heteroaryl.

3. The dibenzofuran derivative according to claim 2, characterized in that The L1 and L2 are each independently selected from a single bond or any one of the following groups: Wherein, -* represents the attachment site of the group.

4. The dibenzofuran derivative according to claim 3, characterized in that The L1 and L2 are single bonds; Preferably, the dibenzofuran derivative has a structure as shown in Formula I-1 or Formula II-1: Wherein, X1, X2, X3, X4, X5, R1, R2, R3, and R4 have the same defined ranges as in claim 1.

5. The dibenzofuran derivative according to any one of claims 1 to 4, characterized in that: The number of N in X1, X2, X3, X4 and X5 is 1-3; Preferably, at least one of X1, X3 and X5 is N; Preferably, X1, X3 and X5 are all N, and X2 and X4 are each independently selected from CR A .

6. The dibenzofuran derivative according to any one of claims 1 to 5, characterized in that: The R A Each is independently selected from any one of hydrogen, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; Preferably, the R A Each is independently selected from hydrogen, substituted or unsubstituted any one of the following groups: Wherein, -* represents the attachment site of the group; Z2 and Z3 are each independently selected from O, S, CR 21 R 22 or NR 23 Any of the following: R 21 , R 22 , R 23 Each is independently selected from any one or a combination of at least two of C1-C30 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl; the R 21 and R 22 Not connected or connected into rings by chemical bonds; R 31 , R 32 Each is independently selected from any one or a combination of at least two of hydrogen, halogen, cyano, C1-C30 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C1-C30 alkoxy, C6-C30 aryl, and C3-C30 heteroaryl; R A The substituted substituents are each independently selected from any one or a combination of at least two of halogen, cyano, C1-C30 straight or branched alkyl, C2-C10 alkenyl, C3-C20 cycloalkyl, C1-C30 alkoxy, C6-C30 aryl, and C3-C30 heteroaryl; the substituted substituents are each independently not connected to the adjacent ring structure or are connected to form a ring through a chemical bond; Preferably, Z2 and Z3 are each independently selected from O, S or CR 21 R 22 Any of the following: Preferably, the R 21 , R 22 Each is independently selected from any one of a C1-C10 straight chain or branched chain alkyl group and a C6-C20 aryl group.

7. The dibenzofuran derivative according to claim 6, characterized in that The R A Each is independently selected from hydrogen or any one of the following groups: Wherein, -* represents the attachment site of the group.

8. The dibenzofuran derivative according to any one of claims 1 to 4, characterized in that: The R1, R2, R3, and R4 are each independently selected from any one of hydrogen, halogen, cyano, substituted or unsubstituted C1-C10 straight or branched alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C20 aryl, and substituted or unsubstituted C3-C20 heteroaryl; Preferably, the substituents substituted in R1, R2, R3, and R4 are each independently selected from any one or a combination of at least two of halogen, cyano, C1-C10 straight or branched alkyl, C3-C10 cycloalkyl, C6-C20 aryl, and C3-C20 heteroaryl; Preferably, R1, R2, R3, and R4 are each independently selected from hydrogen, halogen, unsubstituted or halogenated C1-C6 straight or branched alkyl, cyclohexyl, Any one of the following; -* represents the attachment site of the group.

9. The dibenzofuran derivative according to claim 1, characterized in that The dibenzofuran derivative has a structure shown in any one of the following A1-A232:

10. A use of a dibenzofuran derivative according to any one of claims 1 to 9, characterized in that: The dibenzofuran derivatives are applied to organic electronic devices; Preferably, the organic electronic device comprises an organic electroluminescent device; Preferably, the dibenzofuran derivative is used as a light-emitting layer material in an organic electroluminescent device.

11. 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 dibenzofuran derivative according to any one of claims 1 to 9; Preferably, the organic layer comprises a light-emitting layer, and the light-emitting layer comprises at least one dibenzofuran derivative according to any one of claims 1 to 9; Preferably, the light-emitting layer comprises a host material and a doping material, and the host material comprises at least one dibenzofuran derivative according to any one of claims 1 to 9.

12. A display device, characterized in that: The display device comprises the organic electroluminescent device according to claim 11.

Images