Polysubstituted fluorene benzofuran compound and organic electroluminescent device thereof

Abstract

The invention relates to a polysubstituted fluorene benzofuran compound and a luminescent device thereof. The synthesis of the polysubstituted fluorene benzofuran compound is successfully realized through ingenious synthesis route design. The polysubstituted fluorene benzofuran compound has more appropriate singlet state, triplet state and molecular orbital energy level, and is beneficial to prolonging the service life of the device, improving the luminous efficiency of the device and reducing the driving voltage of the device when being introduced into the organic electroluminescent device. Therefore, the polysubstituted fluorene benzofuran compound provided by the invention is an organic electroluminescent device material with good performance.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent materials, and more specifically, to a polysubstituted fluorenebenzofuran compound and its organic electroluminescent device. Background Technology

[0002] Organic electroluminescent devices, as a novel display technology, possess unique advantages such as self-illumination, wide viewing angle, low energy consumption, high efficiency, thinness, rich colors, fast response speed, wide applicable temperature range, low driving voltage, the ability to manufacture flexible, bendable, and transparent display panels, and environmental friendliness. They can be applied to flat panel displays and next-generation lighting, and can also be used as backlights for LCDs.

[0003] The light-emitting layer consists of two materials: a primary light emitter and dopants. The dopants require high quantum efficiency, while the primary light emitter requires a large bandgap to facilitate energy transfer to the dopants. Displays used in televisions, mobile devices, etc., achieve full color based on the three primary colors of red, green, and blue. The light-emitting layers are composed of red primary light emitter / dopants, green primary light emitter / dopants, and blue primary light emitter / dopants, respectively.

[0004] Currently, materials used for blue light still suffer from low quantum efficiency and poor color purity. The main reason for this is that blue light originates from transitions between energy levels with a wide bandgap. Wide-bandgap organic compounds present certain challenges in molecular design. Secondly, the strong π-π bond interactions within blue light materials result in significant charge transfer characteristics, leading to more non-radiative relaxation channels within the wide bandgap. This exacerbates fluorescence quenching between molecules, reducing the quantum yield of the blue light system.

[0005] Therefore, there is an urgent need to design and synthesize blue light materials with excellent comprehensive performance, which has become an important research topic for materials used in organic electroluminescent devices. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention provides a polysubstituted fluorenebenzofuran compound, which can be used as the main material of organic electroluminescent devices and can improve the driving voltage, luminous efficiency and lifetime of the device.

[0007] This invention provides a polysubstituted fluorenebenzofuran compound having the structure shown in formula (I):

[0008]

[0009] Ar1, Ar2, and Ar3 may be the same or different, and are independently selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C2-C30 heteroaryl groups;

[0010] R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from hydrogen, deuterium, tritium, halogen, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C2-C30 heteroaryl; or two adjacent R4s may be linked together to form a substituted or unsubstituted ring.

[0011] R a R b The same or different, independently selected from hydrogen, deuterium, tritium, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl; or two adjacent R a R b They connect together to form substituted or unsubstituted rings;

[0012] L1, L2, L3, and L may be the same or different, and are independently selected from single bonds, or substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C2-C30 heteroarylene;

[0013] m is selected from 0, 1, 2, 3 or 4;

[0014] n can be the same or different, and can be independently selected from 0, 1, 2, 3 or 4.

[0015] The present invention also provides an organic electroluminescent device comprising an anode, a cathode, and at least one organic layer sandwiched between the anode and the cathode, wherein the at least one organic layer comprises the polysubstituted fluorenebenzofuran compound described in the present invention.

[0016] This invention provides a series of novel polysubstituted fluorenebenzofuran compounds and their light-emitting devices. Through ingenious synthetic route design, this invention successfully synthesizes polysubstituted fluorenebenzofuran compounds, allowing for the adjustment of the physicochemical properties of the materials and the acquisition of more suitable singlet, triplet, and molecular orbital energy levels. Therefore, their introduction into electronic devices with electroluminescent properties is beneficial for improving device lifetime and luminous efficiency while reducing the driving voltage. Thus, the polysubstituted fluorenebenzofuran compounds of this invention represent high-performance organic electroluminescent device materials. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent device.

[0018] Figure 2 The fluorescence emission spectrum is shown in Device Example 2.

[0019] Explanation of reference numerals in the attached figures: 1. Substrate; 2. Anode; 3. Hole injection layer; 4. Hole transport layer; 5. Electron blocking layer; 6. Light emitting layer; 7. Hole blocking layer; 8. Electron transport layer; 9. Electron injection layer; 10. Cathode. Detailed Implementation

[0020] The technical solutions of this invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0021] Unless otherwise specified, the term “substitution” as used herein means that a hydrogen atom in some functional group is replaced by another atom or functional group (i.e., a substituent), and the position of substitution is not limited, as long as the position is where the hydrogen atom is substituted, and when two or more are substituted, the two or more substituents may be the same as or different from each other.

[0022] Unless otherwise specified, the term “substituted or unsubstituted” in this document means either unsubstituted or substituted with one or more substituents selected from the group consisting of: deuterium, tritium, halogen, cyano, substituted or unsubstituted C1-C15 alkyl, substituted or unsubstituted C3-C15 cycloalkyl, substituted or unsubstituted C6-C25 aryl, substituted or unsubstituted C2-C25 heteroaryl, substituted or unsubstituted C6-C25 aryl and / or substituted or unsubstituted C2-C25 heteroaryl-substituted amino, substituted or unsubstituted silyl. Preferably, "substituted or unsubstituted" means unsubstituted or substituted by one or more substituents selected from the group consisting of: deuterium, tritium, halogen, cyano, C1-C10 alkyl, halogen-substituted alkyl, C3-C10 cycloalkyl, C6-C14 aryl, C2-C14 heteroaryl, substituted or unsubstituted C6-C14 aryl and / or substituted or unsubstituted C2-C14 heteroaryl-substituted amino, substituted or unsubstituted silyl, wherein in the case of multiple substituents, the multiple substituents are the same or different from each other. Most preferably, the term "substituted or unsubstituted" means unsubstituted or substituted with one or more substituents selected from the group consisting of: deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano, methyl, trifluoromethyl, deuterated methyl, ethyl, deuterated ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornel, phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, Anthrayl, deuterated anthrayl, phenanthryl, deuterated phenanthryl, triphenylene, pyrene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, spirodifluorenyl, pyridyl, pyrimidinyl, triazinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, N-phenylcarbazoyl, N-biphenylcarbazoyl, dibenzofuranyl, dibenzothiophenyl, trimethylsilyl, triphenylsilyl, where the substituents are the same or different from each other when substituted by multiple substituents.

[0023] Unless otherwise specified, when a substituent on a ring is not indicated as fixed, it means that the substituent is attached to any of the corresponding optional sites on the ring.

[0024] Unless otherwise specified, when a substituent or linking site is located in a bond that extends through two or more rings, it indicates that it can be linked to either of the two or more rings, specifically to any of the corresponding optional sites in the rings.

[0025] Unless otherwise specified, "adjacent groups linked together to form a substituted or unsubstituted ring" means that adjacent groups are linked together and optionally aromatized to form a substituted or unsubstituted aromatic ring, heteroaromatic ring, aliphatic ring, or aliphatic heterocycle. Further, the rings formed include, but are not limited to: benzene rings, naphthalene rings, indene rings, cyclopentane rings, cyclohexane rings, cycloheptane rings, pyridine rings, pyrimidine rings, furan rings, thiophene rings, benzofuran rings, benzothiophene rings, etc. "Adjacent groups" include groups substituted on the same atom, groups substituted on adjacent atoms, and groups spatially adjacent.

[0026] In the compounds of the present invention, any atom not specified as a particular isotope is included as any stable isotope of that atom, and includes atoms at both their natural and non-natural isotopic abundances.

[0027] Unless otherwise specified, the term "alkyl" as used herein refers to a monovalent saturated aliphatic hydrocarbon group, a straight-chain or branched group comprising 1-30 carbon atoms, preferably comprising 1-15 carbon atoms, 1-10 carbon atoms, or 1-6 carbon atoms. Examples include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, etc.

[0028] Unless otherwise specified, the term "cycloalkyl" as used herein refers to a monocyclic saturated aliphatic hydrocarbon group having a specific number of carbon atoms, preferably containing 3-30 carbon atoms, more preferably containing 3-15 carbon atoms, 3-10 carbon atoms, or 3-8 carbon atoms, examples including but not limited to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, norbornyl, etc.

[0029] Unless otherwise specified, the term "aryl" or "aromatic ring group" as used herein refers to an aromatic carbocyclic system containing 6-30 carbon atoms, or 6-25 carbon atoms, or 6-14 carbon atoms, or 6-10 carbon atoms, whether monocyclic, polycyclic, or fused. The term "aryl" may be used interchangeably with the term "aromatic ring." Examples of aryl groups may include, but are not limited to, phenyl, biphenyl, terphenyl, tetraphenyl, 1-phenylnaphthyl, 2-phenylnaphthyl, naphthyl, anthraceneyl, phenanthrene, triphenylene, pyrene, perylene, fluoranyl, benzo[a]fluorenyl, spirofluorenyl, spirodifluorenyl, etc.

[0030] Unless otherwise specified, the term "arylene" as used herein refers to a group obtained by further removing one hydrogen atom from an aryl group. Alelenes contain 6-30 carbon atoms, or 6-25 carbon atoms, or 6-14 carbon atoms, or 6-10 carbon atoms; examples of arylene groups may include, but are not limited to, phenylene, biphenylene, terphenylene, tetraphenylene, phenylenenaphthyl, naphthylene, anthracene, phenanthrene, tricrene, pyrene, perylene, fluoreneanthyl, fluorene, benzo[a]fluorene, spirofluorene, spirodifluorene, etc.

[0031] Unless otherwise specified, the term "heteroaryl" or "heterocyclic" in this document means a monocyclic, polycyclic, or fused-ring cyclic system containing 2-30 carbon atoms, 2-25 carbon atoms, 2-14 carbon atoms, or 3-10 carbon atoms, wherein one, two, three, or more ring atoms are heteroatoms and the remaining atoms are carbon atoms, the heteroatoms being independently selected from oxygen, sulfur, nitrogen, silicon, selenium, or phosphorus atoms. Examples of heteroaryl groups include, but are not limited to, pyrroleyl, furanyl, thiopheneyl, oxazolyl, thiazolyl, imidazolyl, pyridyl, pyrazinyl, pyridazinyl, triazinyl, bipyridyl, bipyrimidinyl, phenylpyridyl, phenylpyrimidinyl, spirofluorenoxazanyl, spirofluorenthionanyl, acridineyl, 9,10-dihydroacridyl, naphridyl, indolyl, phenoxazinyl, phenthiazinyl, phenoxthiazinyl, quinolinyl, and isoquinolinyl. Benzoquinolinyl, benzoisoquinolinyl, quinazolinyl, benzoquinazolinyl, quinoxolinyl, benzoquinoxolinyl, o-phenanthrolinel, benzofuranyl, dibenzofuranyl, naphthobenzofuranyl, benzothiopheneyl, benzothiazolyl, dibenzothiapheneyl, naphthobenzothiapheneyl, benzooxazolyl, naphthooxazolyl, benzoimidazolyl, naphthoimidazolyl, benzothiazolyl, naphthothiazolyl, carbazole, benzocarbazole, etc.

[0032] Unless otherwise specified, the term "heteroaryl" as used herein refers to the group obtained by further removing a hydrogen atom from a heteroaryl group. Heteroaryl groups contain 2-30 carbon atoms, 2-25 carbon atoms, 2-14 carbon atoms, or 3-10 carbon atoms, wherein one, two, three, or more ring atoms are heteroatoms and the remaining atoms are carbon atoms, the heteroatoms being independently selected from oxygen, sulfur, nitrogen, silicon, selenium, or phosphorus atoms. Examples of heteroaryl groups include, but are not limited to, pyridinyl, pyrimidinyl, triazineyl, dibenzofuranyl, dibenzothiopheneyl, and carbazoyl.

[0033] Unless otherwise specified, the terms “halogen” or “halogenated” in this document refer to F, Cl, Br, and I.

[0034] Unless otherwise indicated, the structural formulas described in this invention include all isomers (e.g., enantiomers, diastereomers, and geometric isomers (or conformational isomers)): for example, R and S configurations containing an asymmetric center, (Z) and (E) isomers of double bonds, and (Z) and (E) conformational isomers. Therefore, any single stereochemical isomer of the compounds of this invention, or its enantiomers, diastereomers, or mixtures of geometric isomers (or conformational isomers), is within the scope of this invention.

[0035] It should be understood that, within the scope of this invention, the above-described technical features of this invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here.

[0036] In a first aspect, the present invention provides a polysubstituted fluorenebenzofuran compound having the structure shown in formula (I):

[0037]

[0038] Ar1, Ar2, and Ar3 may be the same or different, and are independently selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C2-C30 heteroaryl groups;

[0039] R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from hydrogen, deuterium, tritium, halogen, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C2-C30 heteroaryl; or two adjacent R4s may be linked together to form a substituted or unsubstituted ring.

[0040] R a R b The same or different, independently selected from hydrogen, deuterium, tritium, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl; or R a R b They connect together to form substituted or unsubstituted rings;

[0041] L1, L2, L3, and L may be the same or different, and are independently selected from single bonds, or substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C2-C30 heteroarylene;

[0042] m is selected from 0, 1, 2, 3 or 4;

[0043] n can be the same or different, and can be independently selected from 0, 1, 2, 3 or 4.

[0044] Preferably, Ar1, Ar2, and Ar3 are the same or different, and are independently selected from substituted or unsubstituted: phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, triphenylene, pyrene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, dibenzofuranyl, dibenzothiopheneyl, 9-phenylcarbazoyl, 9-biphenylcarbazoyl, and 9-naphthylcarbazoyl.

[0045] Preferably, the substituents in "substituted or unsubstituted" of Ar1, Ar2, and Ar3 are selected from: deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano; substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, phenyl, biphenyl, naphthyl, pyridyl, pyrimidinyl; the "substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, isopropyl, tert-butyl, methyl ... The substituents in "propyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, phenyl, biphenyl, naphthyl, pyridyl, pyrimidinyl" are selected from: deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl.

[0046] Preferably, R1, R2, R3, R4, R5, and R6 are the same or different, and are independently selected from hydrogen, deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano, substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, triphenylene, pyrene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, dibenzofuranyl, dibenzothiopheneyl, 9-phenylcarbazoyl, 9-biphenylcarbazoyl, and 9-naphthylcarbazoyl.

[0047] Preferably, the substituents in "substituted or unsubstituted" of R1, R2, R3, R4, R5, and R6 are selected from: deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano; substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, biphenyl, naphthyl, pyridyl, pyrimidinyl; the "substituted or unsubstituted: methyl, ethyl, n-propyl" substituents are selected from: deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano; substituted or unsubstituted: methyl, ethyl, n-propyl The substituents in “cyclopropyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, biphenyl, naphthyl, pyridyl, pyrimidinyl” are selected from: deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl.

[0048] Preferred, R a R b Identical or different, independently selected from hydrogen, deuterium, tritium, substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, phenylenetriene, pyrene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, dibenzofuranyl, dibenzothiophene; or R a R b They can be linked together to form any one of the following cyclic groups:

[0049]

[0050] The R 11 The same or different, independently selected from: hydrogen, deuterium, tritium, fluorine, chlorine, bromine, iodine, substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl; the substituents in "substituted or unsubstituted" are selected from: deuterium, tritium, fluorine, chlorine, bromine, iodine;

[0051] The R 12The same or different, independently selected from: hydrogen, deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano; substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, biphenyl, naphthyl, pyridyl, pyrimidinyl; the substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, iso... The substituents in "butyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, biphenyl, naphthyl, pyridyl, pyrimidinyl" are selected from: deuterium, tritium, fluorine, chlorine, bromine, iodine, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl;

[0052] a1 is selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8; a2 is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; a3 is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12; a4 may be the same or different, and is independently selected from 0, 1, 2, 3 or 4.

[0053] Preferably, L1, L2, L3, and L are the same or different, and are independently selected from single bonds, or one of the following groups:

[0054]

[0055] Among them, R a Selected from hydrogen, deuterium, tritium, halogen, cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C14 aryl, substituted or unsubstituted C2-C12 heteroaryl; or two adjacent R groups. a They connect together to form substituted or unsubstituted C6-C10 aromatic rings;

[0056] b1 is the same or different, and can be selected independently from 0, 1, 2, 3 or 4; b2 is the same or different, and can be selected independently from 0, 1, 2 or 3; b3 is the same or different, and can be selected independently from 0, 1 or 2; b4 is the same or different, and can be selected independently from 0, 1, 2, 3, 4, 5 or 6.

[0057] Preferred, R aSelected from hydrogen, deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano, and substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, phenyl, biphenyl, naphthyl, pyridyl, pyrimidinyl; The substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isopropyl The substituents in "butyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, biphenyl, naphthyl, pyridyl, pyrimidinyl" are selected from: deuterium, tritium, fluorine, chlorine, bromine, iodine, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl.

[0058] In one embodiment, the deuteration rate of the polysubstituted fluorene benzofuran compound is 1-99%, preferably 10-90%, and more preferably 20-90%.

[0059] In one embodiment, the polysubstituted fluorenebenzofuran compound is selected from:

[0060]

[0061]

[0062]

[0063] The above only lists some specific structural forms of polysubstituted fluorene benzofuran compounds represented by formula (I). However, the present invention is not limited to these chemical structures. Any chemical structure based on formula (I) with substituents as defined in the present invention should be included.

[0064] The polysubstituted fluorenebenzofuran compounds of formula (I) described in this invention can be prepared by the following synthetic route:

[0065]

[0066] Wherein, M is selected from -B(OH)2 or

[0067] LG is selected from Ts (p-toluenesulfonyl) and Tf (trifluoromethanesulfonyl).

[0068] Preferably, the compound represented by formula (II) can be prepared by the following synthetic route:

[0069]

[0070] Among them, M1, M2, M3, and M4 may be the same or different, and are independently selected from -B(OH)2 or

[0071] X1, X2, X3, and X4 may be the same or different, and are independently selected from halogens, preferably chlorine, bromine, or iodine;

[0072] R 01 R 02 Alkyl groups, whether identical or different, are independently selected from C1-C4;

[0073] LG is selected from Ts (p-toluenesulfonyl) and Tf (trifluoromethanesulfonyl).

[0074] In a second aspect, the present invention also provides an organic electroluminescent device comprising an anode, a cathode, and at least one organic layer sandwiched between the anode and the cathode, said at least one organic layer comprising the polysubstituted fluorenebenzofuran compound described in the present invention.

[0075] In one embodiment, the organic layer includes a light-emitting layer containing the polysubstituted fluorenebenzofuran compound described in this invention.

[0076] In one embodiment, the organic layer includes a light-emitting layer containing a host material comprising the bis(dibenzofuran) compound of the present invention.

[0077] In one implementation scheme, such as Figure 1 As shown, the organic electroluminescent device of the present invention is obtained by sequentially disposing of each layer (e.g., anode 2, hole injection layer 3, hole transport layer 4, electron blocking layer 5, light-emitting layer 6, hole blocking layer 7, electron transport layer 8, electron injection layer 9 and cathode 10) on a substrate 1.

[0078] The organic electroluminescent device of the present invention is not limited to such a structure. For example, in this multilayer structure, one or more organic layers may be omitted. For example, the hole blocking layer 7 between the light-emitting layer 6 and the electron transport layer 8 may be omitted, and the anode 2, hole injection layer 3, hole transport layer 4, electron blocking layer 5, light-emitting layer 6, electron transport layer 8, electron injection layer 9, and cathode 10 may be sequentially disposed on the substrate 1. Alternatively, the hole injection layer 3 between the anode 2 and the hole transport layer 4, the hole blocking layer 7 between the light-emitting layer 6 and the electron transport layer 8, and the electron injection layer 9 between the electron transport layer 8 and the cathode 10 may all be omitted, and the anode 2, hole transport layer 4, electron blocking layer 5, light-emitting layer 6, electron transport layer 8, and cathode 10 may be sequentially disposed on the substrate 1, finally obtaining the corresponding organic electroluminescent device.

[0079] The organic electroluminescent device of the present invention is not limited to such a structure. For example, in this multilayer structure, one or more organic layers may be omitted. For example, the hole blocking layer 7 between the light-emitting layer 6 and the electron transport layer 8 may be omitted, and the anode 2, hole injection layer 3, hole transport layer 4, electron blocking layer 5, light-emitting layer 6, electron transport layer 8, electron injection layer 9, and cathode 10 may be sequentially disposed on the substrate 1. Alternatively, the hole injection layer 3 between the anode 2 and the hole transport layer 4, the hole blocking layer 7 between the light-emitting layer 6 and the electron transport layer 8, and the electron injection layer 9 between the electron transport layer 8 and the cathode 10 may all be omitted, and the anode 2, hole transport layer 4, electron blocking layer 5, light-emitting layer 6, electron transport layer 8, and cathode 10 may be sequentially disposed on the substrate 1, finally obtaining the corresponding organic electroluminescent device.

[0080] The anode of the organic electroluminescent device of the present invention can be made of known electrode materials. For example, electrode materials with a large work function, such as metals or alloys thereof, such as vanadium, chromium, copper, zinc, and gold; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of metals and oxides such as ZnO:Al or SnO2:Sb; and conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylidene-1,2-dioxo)thiophene] (PEDOT), polypyrrole, and polyaniline. Among these, ITO is preferred.

[0081] As the hole injection layer of the organic electroluminescent device of the present invention, known materials with hole injection properties can be used. Examples include porphyrin compounds represented by copper phthalocyanine, naphthyl diamine compounds, star-shaped triphenylamine compounds, aromatic amine compounds having three or more triphenylamine structures linked by single bonds or divalent groups without heteroatoms, triphenylamine trimers and tetramers, acceptor-type dibenzofuran compounds such as hexacyanoazinebenzophenanthrene, and coating-type polymer materials. These materials can be formed into thin films using known methods such as vapor deposition, spin coating, and inkjet printing.

[0082] As the hole transport layer of the organic electroluminescent device of the present invention, known materials with hole transport properties can be used. In addition, other known materials with hole transport properties can also be used. For example, compounds containing m-carbazole phenyl groups; such as N,N'-diphenyl-N,N'-di(m-tolyl)benzidine (TPD), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB), N,N,N',N'-tetraphenylbenzidine and other benzidine derivatives; 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC); various triphenylamine trimers and tetramers; 9,9',9”-triphenyl -9H, 9'H, 9”H-3, 3':6', 3”-tricarbazole (Tris-PCz), etc. These materials can be used individually as films, or as monolayers mixed with other materials. They can also be used to create stacked structures of individually formed layers, stacked structures of mixed layers, or stacked structures of individually formed layers and mixed layers. These materials can be formed into thin films using known methods such as vapor deposition, spin coating, and inkjet printing.

[0083] In addition, in the hole injection layer or hole transport layer, substances that are further P-doped with tribromoaniline antimony hexachloride, axylene derivatives, etc., which are materials commonly used in this layer, or polymeric compounds whose partial structures have the structure of benzidine derivatives such as TPD, can also be used.

[0084] As the electron blocking layer of the organic electroluminescent device of the present invention, known materials with electron blocking properties can be used. In addition, other known compounds with electron blocking properties can also be used. For example, carbazole derivatives such as 4,4',4”-tris(N-carbazole)triphenylamine (TCTA), 9,9-bis[4-(carbazole-9-yl)phenyl]fluorene, 1,3-bis(carbazole-9-yl)phenyl (mCP), and 2,2-bis(4-carbazole-9-ylphenyl)adamantane (Ad-Cz); and compounds with triphenylsilyl and triarylamine structures, represented by 9-[4-(carbazole-9-yl)phenyl]-9-[4-(triphenylsilyl)phenyl]-9H-fluorene. Compounds with high electron-blocking properties, such as monoamine compounds and various triphenylamine dimers, can be used as single-layer films or mixed with other materials. They can also be used to form stacked structures of single-layer films, stacked structures of mixed films, or stacked structures of single-layer and mixed films. These materials can be formed into thin films using known methods such as vapor deposition, spin coating, and inkjet printing.

[0085] As the light-emitting layer of the organic electroluminescent device of the present invention, it is preferable to include a polysubstituted fluorenebenzofuran compound represented by formula (I) of the present invention. In addition, various metal complexes such as metal complexes of hydroxyquinoline derivatives led by Alq3, compounds having a pyrimidine ring structure, anthracene derivatives, bis(styrene)benzene derivatives, pyrene derivatives, oxazole derivatives, poly(p-phenylene)ethylene derivatives, etc., can also be used.

[0086] The luminescent layer can be composed of a host material and a dopant material. As the host material, a polysubstituted fluorene benzofuran compound of formula (I) of the present invention is preferred. In addition, mCBP, mCP, thiazole derivatives, benzimidazole derivatives, polydialkylfluorene derivatives, and dibenzofuran compounds having a partial structure with an indole ring as a fused ring can also be used. As the dopant material, a polysubstituted fluorene benzofuran compound of the present invention is preferred. In addition, aromatic amine derivatives, styrylamine compounds, boron complexes, fluoranthene compounds, and metal complexes can also be used. Examples include pyrene derivatives, anthracene derivatives, quinacridones, coumarins, rubrene, perylene and their derivatives, benzopyran derivatives, rhodamine derivatives, aminostyryl derivatives, and spirocyclic bisfluorene derivatives. They can be used individually as films, or as monolayers formed by mixing with other materials. They can also be used to create stacked structures of individually formed layers, stacked structures of mixed layers, or stacked structures of individually formed layers and mixed layers. These materials can be formed into thin films using known methods such as vapor deposition, spin coating, and inkjet printing.

[0087] Preferably, the mass ratio of the main material to the dopant material in the light-emitting layer can be 50-99:1-50, and more preferably, the mass ratio can be 80-99:1-20.

[0088] As the hole-blocking layer of the organic electroluminescent device of the present invention, known materials with hole-blocking properties can be used. In addition, other compounds with hole-blocking properties can also be used to form it. For example, metal complexes of phenanthroline derivatives such as 2,4,6-tris(3-phenyl)-1,3,5-triazine (T2T), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), and copper hydroxide (BCP), metal complexes of quinolinol derivatives such as aluminum(III)bis(2-methyl-8-hydroxyquinoline)-4-phenylphenol (BAlq), and various rare earth complexes, oxazole derivatives, triazole derivatives, triazine derivatives, and other compounds with hole-blocking effects. These can be used individually as films, or as monolayers formed by mixing with other materials, or in a stacked structure of individually formed layers, a stacked structure of mixed layers, or a stacked structure of individually formed layers and mixed layers. These materials can be formed into thin films using known methods such as vapor deposition, spin coating, and inkjet printing.

[0089] The hole-blocking material described above can also be used to form the electron transport layer described below. That is, by using the aforementioned known hole-blocking material, a layer that simultaneously serves as a hole-blocking layer and an electron transport layer can be formed.

[0090] As the electron transport layer of the organic electroluminescent device of the present invention, materials with known electron transport properties can be used. In addition, other compounds with electron transport properties can also be used. Examples include metal complexes of hydroxyquinoline derivatives, primarily Alq3 and BAlq; various metal complexes; triazole derivatives; triazine derivatives; oxadiazole derivatives; pyridine derivatives; bis(10-hydroxybenzo[H]quinoline)beryllium (Be(bq)2); benzimidazole derivatives such as 2-[4-(9,10-dinaphthyl-2-anthracene-2-yl)phenyl]-1-phenyl-1H-benzimidazole (ETL); thiadiazole derivatives; anthracene derivatives; carbodiimide derivatives; quinoxaline derivatives; pyridoindole derivatives; phenanthroline derivatives; thiarroline derivatives, etc. They can be used individually as films, or as monolayers formed by mixing with other materials. They can also be used to form stacked structures of individually formed layers, stacked structures of mixed layers, or stacked structures of individually formed layers and mixed layers. These materials can be formed into thin films using known methods such as vapor deposition, spin coating, and inkjet printing.

[0091] As the electron injection layer of the organic electroluminescent device of the present invention, it can be formed using materials known in themselves. For example, alkali metal salts such as lithium fluoride and cesium fluoride; alkaline earth metal salts such as magnesium fluoride; metal complexes of hydroxyquinoline derivatives such as lithium hydroxyquinoline; metal oxides such as aluminum oxide, etc.

[0092] In the electron transport layer or electron injection layer, materials commonly used in this layer can be further doped with metals such as cesium or triarylphosphine oxide derivatives.

[0093] As the cathode of the organic electroluminescent device of the present invention, it is preferable to use an electrode material with a low work function (such as aluminum or magnesium) or an alloy with a low work function (such as magnesium-silver alloy, magnesium-indium alloy, or aluminum-magnesium alloy) as the electrode material.

[0094] As the substrate for this invention, conventional substrates used in organic light-emitting devices, such as glass or plastic, can be used. In this invention, a glass substrate is selected.

[0095] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as are familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of the present invention. The preferred embodiments and materials shown herein are for illustrative purposes only.

[0096] Example 1: Synthesis of BH1

[0097]

[0098] Step 1: 2-Bromo-3-methoxy-6-chlorophenol (60 g, 252.66 mmol), reactant 1 (2-fluorophenylboronic acid, 35.35 g, 252.66 mmol), potassium carbonate (87.30 g, 631.64 mmol), 1,4-dioxane (300 ml), and water (150 ml) were mixed and dissolved by stirring. After purging with nitrogen three times, catalyst Pd(PPh3)4 (1.46 g, 1.26 mmol) was added. After purging with nitrogen three times, the mixture was heated to 85 °C and refluxed for 5 h. The reaction system was then concentrated under reduced pressure at low temperature to obtain the residue. The residue was dissolved and extracted with water and dichloromethane, and the organic phase was separated. The concentrated organic phase was loaded and purified by silica gel column chromatography (petroleum ether: ethyl acetate = 0-100%) to obtain the product of Step 1: 55 g, yield: 86.15%. MS-ESI calculated value [M+H] + 253.67, the actual value is 253.70.

[0099] Step 2: The product from Step 1 (55 g, 217.68 mmol) was dissolved in DMF (200 ml), and powdered potassium carbonate (90.25 g, 653.03 mmol) was added. The mixture was heated to 150 °C and refluxed for 5 h. The mixture was then concentrated under reduced pressure to obtain the residue. The residue was dissolved and extracted with water and dichloromethane, and the organic phase was separated. The organic phase was concentrated, loaded, and purified by silica gel column chromatography (petroleum ether: ethyl acetate = 0-100%) to obtain the product from Step 2: 42 g, yield: 82.93%. MS-ESI calculated value [M+H] + 233.66, the actual measured value is 233.68.

[0100] Step 3: The product from Step 2 (42 g, 180.52 mmol), reactant 2 (ethyl 5-chloro-2-ethylbenzeneboronic acid, 41.24 g, 180.52 mmol), potassium carbonate (62.37 g, 451.3 mmol), 1,4-dioxane (200 ml), and water (100 ml) were stirred and dissolved. After purging with nitrogen three times, catalyst Pd(PPh3)4 (1.04 g, 1.26 mmol) was added. After purging with nitrogen three times, the mixture was heated to 85 °C and refluxed for 5 h. The reaction system was then concentrated under low temperature and reduced pressure to obtain the residue. The residue was dissolved and extracted with water and dichloromethane, and the organic phase was separated. The concentrated organic phase was loaded and purified by silica gel column chromatography (petroleum ether: ethyl acetate = 0-100%) to obtain the product of Step 3: 57 g, yield: 82.91%. MS-ESI calculated value [M+H] + 381.82, the actual measured value is 381.86.

[0101] Step 4: Dissolve the product from Step 3 (57 g, 149.68 mmol) in 150 ml of concentrated sulfuric acid. Heat the solution to 75 °C and react for 5 hours. Then, slowly pour the reaction mixture into water to quench the reaction, precipitating a yellow solid. Allow the mixture to stand and filter to obtain the crude product. Add 100 ml of ethyl acetate, stir, filter, and dry to obtain the Step 4 product: 36 g, yield: 71.85%. MS-ESI calculated value [M+H] + 335.75, the actual measured value is 335.79.

[0102] Step 5: Dissolve the product from Step 4 (36 g, 107.54 mmol) in dichloromethane (300 ml). Add NBS (22.97 g, 129.05 mmol) in portions under ice-water bath conditions, maintaining the temperature below 10°C. After the addition is complete, return to room temperature and continue the reaction. After TLC detection of the reaction's completion, slowly pour the reaction solution into an aqueous sodium bisulfite solution to quench the reaction. Concentrate the organic phase into a yellow solid, add 100 ml of ethyl acetate, slurry, filter, and dry to obtain the product from Step 5: 41 g, yield: 92.17%. MS-ESI calculated value [M+H]+ 414.65, the actual measured value is 414.69.

[0103] Step 6: The product from Step 5 (41 g, 99.12 mmol), reactant 3 (phenylboronic acid, 14.50 g, 118.94 mmol), potassium carbonate (34.25 g, 247.79 mmol), 1,4-dioxane (120 ml), and water (60 ml) were stirred and dissolved. After purging with nitrogen three times, catalyst Pd(PPh3)4 (0.572 g, 0.496 mmol) was added. After purging with nitrogen three times, the mixture was heated to 85 °C and reacted for 5 h. The reaction system was then concentrated under reduced pressure at low temperature to obtain the residue. The residue was dissolved and extracted with water and dichloromethane, and the organic phase was separated. The organic phase was concentrated, loaded, and purified by silica gel column chromatography (petroleum ether: ethyl acetate = 0-100%) to obtain the product of Step 6: 35 g, yield: 85.95%. MS-ESI calculated value [M+H] + 411.85, the actual measured value is 411.90.

[0104] Step 7: The product from Step 6 (35 g, 85.19 mmol), reactant 4 (1-naphthylboronic acid, 17.58 g, 102.23 mmol), potassium carbonate (29.43 g, 212.97 mmol), 1,4-dioxane (120 ml), and water (60 ml) were stirred and dissolved. After purging with nitrogen three times, catalyst Pd(OAc)₂ (95.63 mg, 0.426 mmol) and sphos (1.75 g, 4.26 mmol) were added. After purging with nitrogen three times, the mixture was heated to 85 °C and reacted for 5 h. The reaction system was then concentrated under reduced pressure at low temperature to obtain the residue. The residue was dissolved and extracted with water and dichloromethane, and the organic phase was separated. The organic phase was concentrated, loaded, and purified by silica gel column chromatography (petroleum ether: ethyl acetate = 0-100%) to obtain the product of Step 7: 36 g, yield: 84.09%. MS-ESI calculated value [M+H] + 503.57, measured value is 503.60.

[0105] Step 8: In a 500ml three-necked flask equipped with a reflux condenser and a dropping funnel, add (7.27g, 28.65mmol) iodine and glacial acetic acid (250ml) under nitrogen protection, stir to dissolve, then add hypophosphorous acid (approximately 9.453g, 143.26mmol), and heat to 120℃ to react until the color of the system disappears. Next, the product from Step 7 (36 g, 71.63 mmol) was added all at once, and the mixture was heated under reflux for 4 hours. After cooling to room temperature, the solid was poured into water, precipitating a large amount of white solid. The solid was filtered, washed with water, and dried to obtain a white solid. This solid was dissolved in tetrahydrofuran (250 ml), cooled to 0°C, and sodium tert-butoxide powder (20.65 g, 214.89 mmol) was added. The temperature was maintained for 1 hour, and reactant 5, iodomethane (23.39 g, 164.76 mmol), was added dropwise. After the addition was complete, the mixture was stirred for 5 hours, and then concentrated under reduced pressure to obtain the residue. The residue was dissolved and extracted with water and dichloromethane, and the organic phase was separated. The organic phase was concentrated, loaded, and purified by silica gel column chromatography (petroleum ether: ethyl acetate = 0-100%) to obtain the product from Step 8: 30 g, yield: 81.06%. MS-ESI calculated value [M+H] + 517.64, the actual measured value is 517.68.

[0106] Step 9: Dissolve the product from Step 8 (30 g, 58.07 mmol) in dichloromethane (200 ml), cool to 0 °C, and add boron tribromide (21.82 g, 87.10 mmol) dropwise. After the addition is complete, maintain the temperature for 0.5 h, then return to room temperature and continue stirring for 5 h. Quench with ice water, dissolve and extract in dichloromethane, separate the liquid to obtain the organic phase, concentrate and load the organic phase, and purify by silica gel column chromatography (petroleum ether: ethyl acetate = 0-100%) to obtain the product from Step 9: 25 g, yield: 85.66%. MS-ESI calculated value [M+H] + 503.61, the actual measured value is 503.65.

[0107] Step 10: Dissolve the product from Step 9 (25 g, 49.74 mmol) in dichloromethane (200 ml), cool to 0 °C, add triethylamine (10.07 g, 99.48 mmol), and dropwise add trifluoromethanesulfonic anhydride (21.05 g, 74.61 mmol). After the addition is complete, maintain the temperature for 0.5 h, then return to room temperature and continue stirring for 5 h. After quenching with ice water, dissolve and extract in dichloromethane, separate the liquid to obtain the organic phase, concentrate and load the organic phase, and purify by silica gel column chromatography (petroleum ether: ethyl acetate = 0-100%) to obtain the product of Step 10: 30 g, yield: 95.03%. MS-ESI calculated value [M+H] + The actual value is 635.67, while the measured value is 635.71.

[0108] Step 11: The product from Step 10 (10 g, 15.75 mmol), reactant 5 (phenylanthracite, 6.11 g, 20.48 mmol), anhydrous potassium phosphate (8.36 g, 39.39 mmol), and 1,4-dioxane (150 ml) were stirred, mixed, and dissolved. After purging with nitrogen three times, catalyst Pd(OAc)₂ (17.61 mg, 0.08 mmol) and sphos (0.33 g, 0.78 mmol) were added. After purging with nitrogen three times, the mixture was heated to 85 °C and reacted for 5 h. The reaction system was then concentrated under reduced pressure at low temperature to obtain the residue. The residue was dissolved and extracted with water and dichloromethane, and the organic phase was separated. The organic phase was concentrated, loaded, and purified by silica gel column chromatography (petroleum ether: ethyl acetate = 0-100%) to obtain BH₈: 9.3 g, yield: 80.11%. MS-ESI calculated value [M+H] + 739.93, the actual measured value is 739.96.

[0109] Example 2-12

[0110] Referring to the synthetic route in Example 1, and selecting the corresponding reactants 1, 2, 3, 4, and 5, a series of specific compounds of the present invention were prepared (see Table 1).

[0111] Table 1

[0112]

[0113]

[0114]

[0115] The yield and target product mass spectra are shown in Table 2 below:

[0116] Table 2

[0117]

[0118]

[0119]

[0120]

[0121] Example 13: Synthesis of BH13

[0122] Compound BH7 (5 g, 6.713 mmol), 10% palladium on carbon (0.2 g), and heavy water (150 mL) were added to a 300 mL high-pressure reactor and heated to 240 °C for 12 h. The reaction system was cooled to room temperature, the organic phase was concentrated, the heavy water was recovered, and the concentrated solid was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 0-100%) to obtain 4.5 g of product (yield: 90%). MS-ESI test value [M+H] + The molecular weight is 774.02, compared to 744.99 for BH7. It has 28 deuteration substitutions and a deuteration rate of 89.47%.

[0123] Example 14: Synthesis of BH14

[0124] Compound BH31 (5 g, 6.77 mmol), 10% palladium on carbon (0.2 g), and heavy water (150 mL) were added to a 300 mL high-pressure reactor and heated to 240 °C for 12 h. The reaction system was cooled to room temperature, the organic phase was concentrated, the heavy water was recovered, and the concentrated solid was purified by silica gel column chromatography (petroleum ether:ethyl acetate = 0-100%) to give 4.4 g of product (yield: 88%). MS-ESI test value [M+H] + The molecular weight is 766.98, compared to 738.93 for BH31. It has 27 deuteration substitutions and a deuteration rate of 71.05%.

[0125] Example 15: Fabrication of Organic Electroluminescent Device 1 (Organic EL Device 1)

[0126] Hole injection layer 3, hole transport layer 4, electron blocking layer 5, light-emitting layer 6, electron transport layer 8, electron injection layer 9, and cathode 10 are sequentially formed on a transparent anode 2 pre-formed on a glass substrate 1 to prepare a material as shown in the image. Figure 1 The organic electroluminescent device shown (but excluding hole blocking layer 7).

[0127] Specifically, a glass substrate with a 100 nm thick ITO film was ultrasonically treated in Decon 90 alkaline cleaning solution, rinsed in deionized water, cleaned three times each in acetone and ethanol, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and then bombarded with a low-energy cation beam. The glass substrate with the ITO electrode was then placed in a vacuum chamber and evacuated to a vacuum level of 4 × 10⁻⁶. -4 ×10 -5Pa. Then, 97wt% HIL / 3wt% HTL were deposited on the glass substrate with the ITO electrode at a deposition rate of 0.2nm / s to form a layer with a thickness of 10nm, serving as a hole injection layer. On the hole injection layer, HTL was deposited at a deposition rate of 0.2nm / s to form a layer with a thickness of 40nm, serving as a hole transport layer. On the hole transport layer, EBL was deposited at a deposition rate of 0.2nm / s to form a layer with a thickness of 10nm, serving as an electron blocking layer. On the electron blocking layer, a dual-source co-evaporation was performed with the compound (BH1) from Example 1 as the host material at a deposition rate of 0.19nm / s and the BD1 as the dopant material at a deposition rate of 0.01nm / s to form a layer with a thickness of 20nm, serving as a light-emitting layer, with the BD1 doping weight ratio being 5wt%. ZADN is deposited on the light-emitting layer at a deposition rate of 0.2 nm / s to form a 40 nm thick layer, serving as the electron transport layer. Liq is then deposited on the electron transport layer at a deposition rate of 0.02 nm / s to form a 2 nm thick layer, serving as the electron injection layer. Finally, aluminum is deposited on the electron injection layer at a deposition rate of 0.5 nm / s or higher to form a 100 nm thick cathode.

[0128] Examples 16-28: Fabrication of Organic EL Devices 2-14

[0129] Referring to the fabrication conditions of organic EL device 1 in Example 15, the only difference is that BH3, BH7, BH12, BH16, BH22, BH26, BH31, BH41, BH46, BH51, BH52, BH53, and BH54 are used instead of BH1 in Example 15 to fabricate organic EL devices 2-14 respectively.

[0130] Comparative Examples 1-6: Fabrication of Monolayer Organic EL Devices (Comparative Examples 1-6)

[0131] Referring to the fabrication conditions of organic EL device 1 in Example 15, the only difference is that DBH1, DBH2, and DBH3 are used instead of BH1 in Example 15 to fabricate organic EL devices Comparative Examples 1-6 respectively.

[0132] The structures of the compounds involved in the organic EL devices and comparative examples of organic EL devices are as follows:

[0133]

[0134] At room temperature in atmospheric conditions, the luminescence characteristics of organic EL devices 1-14 fabricated in Examples 15-28 and Comparative Examples 1-6 were measured when a DC voltage was applied. The current-luminosity-voltage characteristics of the devices were obtained using a Keithley source measurement system (Keithley 2400 Sourcemeter, Keithley 2000 Currentmeter) with a calibrated silicon photodiode. The electroluminescence spectra were measured using a Photo Research PR655 spectrometer. The external quantum efficiency of the devices was calculated using the method described in Adv. Mater., 2003, 15, 1043-1048. The measurement results are shown in Table 3.

[0135] Table 3

[0136]

[0137] The organic EL devices in Table 3 use the polysubstituted fluorenylbenzofuran compounds of this invention as the blue light host material of the emitting layer, and are equipped with the blue light guest material BD1. The comparative examples of organic EL devices use the fluorenylbenzofuran structures DBH1 and DBH2 disclosed in patents CN107922836B and CN113582955B, and the naphthalene-anthracene monosubstituted dibenzofuran DBH3 containing naphthanoanthracene group used in the existing market, as the blue light host material of the emitting layer, and the same blue light guest.

[0138] As shown in Table 3, compared with devices composed of similar structures such as DBH1 and DBH2, devices 1-14 of the present invention exhibit superior performance. This is mainly because, compared to these structures, introducing aryl groups onto the fluorene group enhances conjugation, modulates its singlet, triplet, and molecular orbital energy levels, and improves the luminescence quantum efficiency, resulting in superior performance. Furthermore, the performance results of devices 1-14 indicate that devices corresponding to the polysubstituted fluorene benzofuran compounds of the present invention containing deuterium atoms have higher efficiency and longer lifetimes than those corresponding to compounds without deuterium atoms, because CD bonds are more stable than CH bonds. It was also found that non-directed deuteration and full deuteration have similar effects, because deuteration involves substituting CH bonds with lower bond energies, and the more stable CH bonds are less likely to be deuterated. Secondly, the effects of deuteration at different sites vary, mainly because the charge distribution in the molecule differs, resulting in different CH bond energies and varying stability.

[0139] Meanwhile, in terms of voltage, efficiency, and lifetime, the monolayer organic EL device made from the compounds of this invention exhibits lower voltage, higher efficiency, and longer lifetime compared to devices composed of DBH3, a commercially available material. This demonstrates that devices using the compounds of this invention as the main blue light source generally possess superior performance. On one hand, compared to introducing a fluorene group into a simple dibenzofuran structure, fluorene possesses high thermal stability, high chemical stability, and high carrier transport. On the other hand, modifying fluorene with aryl groups can enhance conjugation, thereby providing various performance benefits. Therefore, introducing it into molecules with electroluminescent properties is beneficial for improving device stability and luminous efficiency, and reducing device driving voltage.

[0140] In addition, from Figure 2 The results shown indicate that when the polysubstituted fluorenebenzofuran compounds of the present invention are used as the main material of the light-emitting layer in the device, the light emission pattern of the device is not affected, indicating that energy can be completely transferred to the light-emitting material in the device.

[0141] As can be seen from the above, the polysubstituted fluorenebenzofuran compounds of the present invention can effectively reduce the operating voltage and simultaneously improve the external quantum efficiency and extend the device life compared with the blue light host materials commonly used in the prior art.

[0142] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A polysubstituted fluorenebenzofuran compound having the structure shown in formula (I): in, Ar1, Ar2, and Ar3 may be the same or different, and are independently selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C2-C30 heteroaryl groups; R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from hydrogen, deuterium, tritium, halogen, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C2-C30 heteroaryl; or two adjacent R4s may be linked together to form a substituted or unsubstituted ring. R a R b The same or different, independently selected from hydrogen, deuterium, tritium, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C2-C30 heteroaryl; or R a R b They connect together to form substituted or unsubstituted rings; L1, L2, L3, and L may be the same or different, and are independently selected from single bonds, or substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C2-C30 heteroarylene; m is selected from 0, 1, 2, 3 or 4; n can be the same or different, and can be independently selected from 0, 1, 2, 3 or 4.

2. The polysubstituted fluorenebenzofuran compound according to claim 1, characterized in that, Ar1, Ar2, and Ar3 may be the same or different, and are independently selected from substituted or unsubstituted compounds: phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, triphenylene, pyrene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, dibenzofuranyl, dibenzothiopheneyl, 9-phenylcarbazolyl, 9-biphenylcarbazolyl, and 9-naphthylcarbazolyl.

3. The polysubstituted fluorenebenzofuran compound according to claim 1, characterized in that, R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from hydrogen, deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano, substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, phenylenetriethylene, pyrene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, dibenzofuranyl, dibenzothiopheneyl, 9-phenylcarbazoyl, 9-biphenylcarbazoyl, and 9-naphthylcarbazoyl.

4. The polysubstituted fluorenebenzofuran compound according to claim 1, characterized in that, R a R b Identical or different, independently selected from hydrogen, deuterium, tritium, substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, phenylenetriene, pyrene, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, dibenzofuranyl, dibenzothiophene; or R a R b They can be linked together to form any one of the following cyclic groups: The R 11 The same or different, independently selected from: hydrogen, deuterium, tritium, fluorine, chlorine, bromine, iodine, substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl; The R 12 The same or different, independently selected from: hydrogen, deuterium, tritium, fluorine, chlorine, bromine, iodine, cyano, substituted or unsubstituted: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, biphenyl, naphthyl, pyridyl, pyrimidinyl; a1 is selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8; a2 is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10; a3 is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12; a4 may be the same or different, and is independently selected from 0, 1, 2, 3 or 4.

5. The polysubstituted fluorenebenzofuran compound according to claim 1, characterized in that, The L1, L2, L3, and L may be the same or different, and are independently selected from single bonds, or from one of the following groups: Among them, R a Selected from hydrogen, deuterium, tritium, halogen, cyano, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C14 aryl, substituted or unsubstituted C2-C12 heteroaryl; or two adjacent R groups. a They connect together to form substituted or unsubstituted C6-C10 aromatic rings; b1 is the same or different, and can be selected independently from 0, 1, 2, 3 or 4; b2 is the same or different, and can be selected independently from 0, 1, 2 or 3; b3 is the same or different, and can be selected independently from 0, 1 or 2; b4 is the same or different, and can be selected independently from 0, 1, 2, 3, 4, 5 or 6.

6. The polysubstituted fluorenebenzofuran compound according to claim 1, characterized in that, The deuteration rate of the polysubstituted fluorene benzofuran compound is 1-99%, preferably 10-90%, and more preferably 20-90%.

7. The polysubstituted fluorenebenzofuran compound according to claim 1, characterized in that, The polysubstituted fluorenebenzofuran compounds are selected from:

8. The method for preparing the polysubstituted fluorenebenzofuran compound according to claim 1, comprising: Wherein, M is selected from -B(OH)2 or LG is selected from Ts (p-toluenesulfonyl) and Tf (trifluoromethanesulfonyl). The compound represented by formula (II) was prepared via the following synthetic route: Among them, M1, M2, M3, and M4 may be the same or different, and are independently selected from -B(OH)2 or X1, X2, X3, and X4 may be the same or different, and are independently selected from halogens, preferably chlorine, bromine, or iodine; R 01 R 02 Alkyl groups, whether identical or different, are independently selected from C1-C4; LG is selected from Ts (p-toluenesulfonyl) and Tf (trifluoromethanesulfonyl).

9. An organic electroluminescent device comprising an anode, a cathode, and at least one organic layer sandwiched between the anode and the cathode, said at least one organic layer comprising a polysubstituted fluorenebenzofuran compound as described in any one of claims 1-7.

10. The organic electroluminescent device according to claim 9, characterized in that, The organic layer includes a light-emitting layer, which contains the polysubstituted fluorenebenzofuran compounds described in this invention.

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