Organic compounds and their use, organic electroluminescent devices

Abstract

This invention provides a compound and its application. The compound has the structure shown in Formula I. When the compound of this invention is used in an organic electroluminescent device, especially as the host material of the light-emitting layer, it can effectively improve the current efficiency of the device and achieve the best effect.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescence technology, and more particularly to an organic compound and its applications, as well as organic electroluminescent devices. Background Technology

[0002] In recent years, organic light-emitting diodes (OLEDs) have developed rapidly and have gained a foothold in the field of information display. This is mainly due to the fact that OLED devices can use highly saturated red, green, and blue primary colors to create full-color display devices, and can achieve vibrant colors, thinness, and flexibility without the need for an additional backlight. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, and organic sensors.

[0003] The core of OLED devices is a thin-film structure containing various organic functional materials. Common functionalized organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, as well as light-emitting host materials and light-emitting guest materials (dyes), etc.

[0004] Various organic materials have been developed and, combined with specific device structures, can enhance carrier mobility, regulate carrier balance, improve electroluminescence efficiency, and delay device decay. Based on the light emission mechanism, they can be divided into fluorescent materials that emit light through singlet excited states and phosphorescent materials that emit light through triplet excited states. According to photochemical principles, organic electrophosphorescent devices can simultaneously capture singlet and triplet excitons through an internal conversion process, thus theoretically achieving 100% internal quantum efficiency. In terms of the structure of organic electrophosphorescent devices, phosphorescent materials are typically doped into the host material as guest materials, or the guest material is chemically bonded to the host material to form a single molecular structure. The host and guest materials serve as the emitting layer. By introducing suitable electrons and holes, and through the transport layer, phosphorescence is emitted through exciton radiation decay under the influence of an applied electric field.

[0005] However, existing host materials still cannot meet the requirements of OLED devices in terms of current efficiency, start-up voltage, cost, and other aspects. Therefore, there is an urgent need in this field to develop an organic electroluminescent material that can improve device luminous efficiency, reduce driving voltage, and extend lifespan. To obtain organic electrophosphorescent devices with excellent overall performance, it is necessary to design suitable host materials. Summary of the Invention

[0006] The purpose of this invention is to provide a compound that, when applied to the light-emitting layer of an organic electroluminescent device, can effectively reduce the driving voltage and improve the luminous efficiency of the device.

[0007] To achieve this objective, the present invention adopts the following technical solution: an organic compound, characterized in that it has the structure shown in formula (I);

[0008]

[0009] Ar 1 Select from equation (a2) or equation (a3):

[0010]

[0011] Where X represents O and S;

[0012] X 9 ~X 24 Independently selected from CR 2 Or N, the R 2 Independently selected from hydrogen, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C 20 Chain alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl, substituted or unsubstituted C1-C 20 Alkoxy, substituted or unsubstituted C1-C 20 Silyl, substituted or unsubstituted C6-C 60 arylamino, substituted or unsubstituted C3-C 60 heteroarylamino, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C3-C 60 One of the heteroaryl groups, wherein the R 2 It can independently connect with the connected aromatic ring to form a ring or not connect to form a ring;

[0013] Ar 2 As shown in equation (a1):

[0014]

[0015] X 1 ~X 8 Independently selected from CR 1 Or N, the R 1 Independently selected from hydrogen, substituted or unsubstituted C1 to C2. 20 Chain alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl, substituted or unsubstituted C1-C 20 Alkoxy, substituted or unsubstituted C1-C 20 Silyl, substituted or unsubstituted C6-C 60 arylamino, substituted or unsubstituted C3-C 60 heteroarylamino, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C3-C60 One of the heteroaryl groups, wherein the R 1 It can independently connect with the connected aromatic ring to form a ring or not connect to form a ring;

[0016] Ar 3 Represents the following groups,

[0017]

[0018] A 1 ~A 5 Independently selected from CR 4 Or N, and at least one of them is N, R 4 Independently selected from hydrogen, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C 20 Chain alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl, substituted or unsubstituted C1-C 20 Alkoxy, substituted or unsubstituted C1-C 20 Silyl, substituted or unsubstituted C6-C 60 arylamino, substituted or unsubstituted C3-C 60 heteroarylamino, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C3-C 60 One of the heteroaryl groups; adjacent R 4 They can be connected to form a ring.

[0019] The substitution of the above-mentioned substituted or unsubstituted groups is selected from halogens, cyano groups, C1-C1 groups. 17 Amino, C1-C 17 Carboxyl group, C1-C 17 Aldehyde group, C1-C 17 Ester group, C1-C 12 Chain alkyl groups, C3-C 12 cycloalkyl, C2-C 10 alkenyl, C1-C 10 alkoxy or thioalkoxy, C6-C 30 arylamino, C3-C 30 heteroarylamino, C6-C 30 aryl, C3~C 30 It is replaced by one or more groups in the heteroaryl group.

[0020] The key structural features of the compound shown in formula (I) above can be summarized as follows: Ar 1 and Ar 2 Ar is an electron-rich substituent group (electron donor). 3The electron-donor and electron-acceptor groups are electron-deficient groups (electron acceptors). The positions of these groups on the benzene ring are also crucial; the electron donor is located at the para position, and the electron acceptor is adjacent to the nitrogen atom and connected to the electron donor group on the benzene ring. This combination of factors allows the compounds of this invention, when used as the host material for the luminescent layer, to significantly improve luminous efficiency, reduce excitation voltage, and enhance lifetime.

[0021] The specific reasons for the superior performance of the compounds of the present invention are not yet clear, but it is speculated that the reasons may be as follows:

[0022] Weak carrier mobility and unbalanced charge in the emissive layer are detrimental to the luminous efficiency of organic light-emitting devices. This invention pertains to bipolar host materials. To balance electron and hole mobilities, such materials typically employ a more flexible selection of two units and an equal number of electron-donating / accepting groups to achieve carrier transport balance. In this invention, with a 2:1 ratio of electron-donating / accepting groups, the electron and hole mobilities of the compound material are more balanced. This may be because the electron donor and acceptor units themselves have unbalanced mobilities; a slight bias towards hole units is more beneficial for balancing electron and hole mobilities. Simultaneously, the structural sites of the compound in this invention, with the electron donor located in the para position, effectively prevent charge transfer between the electron donor and acceptor units, thus improving device performance. Furthermore, the HOMO energy level is distributed in the electron-donating group (e.g., 9-carbazole) where the N atom is attached to the benzene ring, while the LUMO energy level is distributed in the electron-accepting group Ar. 3 These two adjacent connections can effectively suppress charge transfer between electron donor and acceptor units, forming a π-conjugate bridge with a distorted conformation, making them relatively independent of each other.

[0023] It should be noted that in this specification, C a ~C b The expression indicates that the group has a to b carbon atoms. Unless otherwise specified, the number of carbon atoms generally does not include the number of carbon atoms of the substituents.

[0024] In the above substituents, the carbon number of the C1-C10 chain alkyl groups can be C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the carbon number of the C3-C10 cycloalkyl groups can be C4, C5, C6, C7, C8, C9, C10, etc.; the carbon number of the C1-C10 alkoxy groups can be C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the carbon number of the C1-C10 thioalkoxy groups can be C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; and the carbon number of the C6-C30 monocyclic aryl groups can be C2, C3, C4, C5, C6, C7, C8, C9, C10, etc. The carbon numbers of the C10-C30 fused-ring aryl groups can be C10, C12, C14, C16, C18, C20, C26, C28, etc.; the carbon numbers of the C3-C30 monocyclic heteroaryl groups can be C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, etc.; the carbon numbers of the C6-C30 fused-ring heteroaryl groups can be C10, C12, C14, C16, C18, C20, C26, C28, etc.

[0025] In this invention, unless otherwise specified, the description of chemical elements generally includes the concept of isotopes with the same chemical properties. For example, the description of "hydrogen" also includes the concepts of "deuterium" and "tritium" with the same chemical properties, and carbon (C) includes... 12 C 13 C, etc., will not be elaborated further.

[0026] In this invention, the "substituted or unsubstituted" group can replace one substituent or multiple substituents. When there are multiple substituents, they can be selected from different substituents. In this invention, when the same expression is used, they all have the same meaning, and the selection range of substituents is as shown above and will not be repeated one by one.

[0027] In this specification, "each independently" means that when there are multiple subjects, they may be the same or different from each other.

[0028] In the structural formulas disclosed in this specification, the way the ring structure is represented by "—" indicates that the connection point is located at any position on the ring structure where bonding can occur.

[0029] Unless otherwise specified in this specification, aryl and heteroaryl groups include both monocyclic and fused-ring types. A monocyclic aryl group refers to a molecule containing at least one phenyl group. When the molecule contains at least two phenyl groups, the phenyl groups are independent of each other and connected by single bonds, such as phenyl, diphenyl, and terphenyl. A fused-ring aryl group refers to a molecule containing at least two benzene rings, but the benzene rings are not independent of each other; instead, they are fused together by sharing ring edges, such as naphthyl and anthracene. A monocyclic heteroaryl group refers to a molecule containing at least one heteroaryl group. When the molecule contains one heteroaryl group and other groups (such as aryl, heteroaryl, alkyl, etc.), the heteroaryl group and other groups are independent of each other and connected by single bonds, such as pyridine, furan, and thiophene. A fused-ring heteroaryl group refers to a molecule formed by the fusion of at least one phenyl group and at least one heteroaryl group, or by the fusion of at least two heteroaryl rings, such as quinoline, isoquinoline, benzofuran, dibenzofuran, benzothiophene, and dibenzothiophene.

[0030] “R 1 ~R 3 When there are multiple Rs, multiple Rs 1 Multiple Rs can be connected to form a ring. 2 Multiple Rs can be connected to form a ring. 3 "They can be connected to form a ring" means: using R 1 For example, two R 1 Between, or more R 1 They are linked together and together with the benzene ring they are bonded to form an aliphatic or aromatic ring structure. If an aromatic ring structure is formed, it can also form a fused ring structure with the benzene ring it is bonded to, such as naphthyl, anthracene, or triphenylene structures.

[0031] In this specification, C6 to C6 are substituted or unsubstituted. 30 The aryl group is preferably C6-C6. 20The aryl group is more preferably a group from the group consisting of phenyl, naphthyl, anthracene, benzo[a]anthrayl, phenanthryl, benzo[a]phenanthryl, pyrene, pyryl, peryl, fluoranyl, tetraphenyl, pentaphenyl, benzo[a]pyrene, biphenyl, azophenyl, terphenyl, triphenyl, tetraphenyl, fluorenyl, spirodifluorenyl, dihydrophenanthryl, dihydropyrene, tetrahydropyrene, cis or trans indo[a]fluorenyl, trimerinyl, isotriterinyl, spirotriterinyl, and spiroisotriterinyl. Specifically, the biphenyl group is selected from 2-biphenyl, 3-biphenyl, and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, meta-terphenyl-4-yl, meta-terphenyl-3-yl, and meta-terphenyl-2-yl; the naphthyl group includes 1-naphthyl or 2-naphthyl; the anthracene group is selected from 1-anthrayl, 2-anthrayl, and 9-anthrayl; the fluorenyl group is selected from 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, and 9-fluorenyl; the pyrene group is selected from 1-pyrene, 2-pyrene, and 4-pyrene; and the tetraphenyl group is selected from 1-tetraphenyl, 2-tetraphenyl, and 9-tetraphenyl. Preferred examples of aryl groups in this invention include those composed of phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthryl, indene, fluorenyl and their derivatives, fluoranyl, triphenylene, pyrene, perylene, etc. The group is selected from the group consisting of 1-triphenyl-4-yl, 3-triphenyl-3-yl, 2-triphenyl-2-yl, 4-triphenyl-3-yl, 3-triphenyl-4-yl, 3-triphenyl-3-yl, and 3-triphenyl-2-yl; the naphthyl group includes 1-naphthyl or 2-naphthyl; the anthracene group is selected from the group consisting of 1-anthrayl, 2-anthrayl, and 9-anthrayl. The fluorenyl group is selected from the group consisting of 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, and 9-fluorenyl; the fluorenyl derivative is selected from the group consisting of 9,9'-dimethylfluorenyl, 9,9'-spirodifluorenyl, and benzo[a]fluorenyl; the pyrene group is selected from the group consisting of 1-pyrene, 2-pyrene, and 4-pyrene; the tetraphenyl group is selected from the group consisting of 1-tetraphenyl, 2-tetraphenyl, and 9-tetraphenyl.

[0032] Specific examples of aryl groups in this invention can be exemplified by removing one hydrogen atom from the aryl group examples described above, resulting in a divalent group.

[0033] In this invention, heteroatoms are generally selected from N, O, S, P, Si and Se, and are preferably selected from N, O and S.

[0034] In this specification, C3 to C3 are substituted or unsubstituted. 30 Heteroaryl groups are preferably C4-C5. 20Heteroaryl groups, more preferably nitrogen-containing heteroaryl groups, oxygen-containing heteroaryl groups, sulfur-containing heteroaryl groups, etc., specific examples include: furanyl, thiopheneyl, pyrroleyl, pyridyl, benzofuranyl, benzothiopheneyl, isobenzofuranyl, isobenzothiopheneyl, indolyl, isoindolyl, dibenzofuranyl, dibenzothiopheneyl, carbazoleyl and its derivatives, quinolinyl, isoquinolinyl, acridineyl, phenanthridineyl, benzo-5,6-quinolinyl, benzo-6,7-quinolinyl, etc. Benzo-7,8-quinolinyl, phenothiazinyl, phenothiazinyl, pyrazolyl, indazoleyl, imidazolyl, benzimidazoleyl, naphthiazoleyl, phenanthiazoleyl, pyridinium-imidazolyl, pyrazinium-imidazolyl, quinoxalinium-imidazolyl, oxazolyl, benzoxoxazolyl, naphthoxoxazolyl, anthraquinoxazolyl, phenanthoxoxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1, 5-Diazathanel, 2,7-Diazapyrene, 2,3-Diazapyrene, 1,6-Diazapyrene, 1,8-Diazapyrene, 4,5-Diazapyrene, 4,5,9,10-Tetrazaperyl, Pyrazinyl, Phenazinyl, Phenthiazinyl, Naphthidyl, Azacarbazolyl, Benzocarbazolyl, Phenanthrolinel, 1,2,3-Triazolyl, 1,2,4-Triazolyl, Benzotriazolyl, 1,2,3-Oxadiazolyl, 1,2,4 -Omnidiazole, 1,2,5-Omnidiazole, 1,2,3-Thiadiazole, 1,2,4-Thiadiazole, 1,2,5-Thiadiazole, 1,3,4-Thiadiazole, 1,3,5-Triazine, 1,2,4-Triazine, 1,2,3-Triazine, Tetrazolium, 1,2,4,5-Tetraazine, 1,2,3,4-Tetraazine, 1,2,3,5-Tetraazine, Purine, Pteridyl, Indazine, Benzothiadiazole, etc. Preferred examples of heteroaryl groups in this invention include furanyl, thiopheneyl, pyrroleyl, benzofuranyl, benzothiopheneyl, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothiopheneyl, carbazoleyl, and their derivatives, wherein the carbazoleyl derivative is preferably 9-phenylcarbazole, 9-naphthylcarbazole, benzocarbazole, dibenzocarbazole, or indolocarbazole.

[0035] Specific examples of heteroaryl groups in this invention can be exemplified by removing one hydrogen atom from the aforementioned heteroaryl examples to obtain a divalent group.

[0036] The aryl group in this invention can be exemplified by the monovalent group composed of the above-mentioned aryl and heteroaryl groups and oxygen.

[0037] In this specification, C1 to C 30Examples of alkyl groups include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, adamantyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, etc.

[0038] In this specification, C3 to C 20 Cycloalkyl groups include monocycloalkyl and polycycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.

[0039] In this specification, C1 to C 30 Examples of alkoxy groups include: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentooxy, isopentoxy, hexoxy, heptoxy, octoxy, nonoxy, decoxy, undecyloxy, dodecyloxy, etc., among which methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy, sec-butoxy, isobutoxy, isopentoxy, and isopentoxy are preferred, and methoxy is more preferred.

[0040] In this specification, C1 to C 30 Examples of silane groups can be those formed at C1 to C1. 30 The silyl groups substituted by the alkyl groups listed above can be specifically categorized as: methylsilyl, dimethylsilyl, trimethylsilyl, ethylsilyl, diethylsilyl, triethylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, etc.

[0041] Examples of halogens in this specification include fluorine, chlorine, bromine, and iodine.

[0042] More specifically, as mentioned above, R 1 ~R 3Preferred radicals include hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, phenyl, naphthyl, anthracene, benzo[a]anthrayl, phenanthrene, benzo[a]phenanthrene, pyrene, pyrene, peryl, fluoranyl, tetraphenyl, pentaphenyl, benzo[a]pyrene, biphenyl, amphyl, terphenyl, triphenyl, tetraphenyl, fluorene, spirodifluorene, dihydrogen phenanthrene, dihydropyrene, tetrahydropyrene, cis or trans indofluorenyl, trimerinyl, isotrimerininyl, spirotrimerininyl, spiroisotrimerininyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thiopheneyl, benzothiopheneyl, isobenzothiopheneyl, dibenzothiopheneyl, pyrroleyl, isoindoleyl, carbazoleyl, indocarbazoleyl, pyridinyl, quinolinyl, isoquinolinyl, acridineyl, phenanthridineyl, benzo-5,6-quinolinyl, benzo-6,7-quinolinyl, benzo-7,8-quinolinyl, pyrazolyl, indazoleyl, imidazoleyl, benzimidazoleyl, naphzimidazoleyl, phenanthrenemidazoleyl, pyridinidazoleyl Pyrazinimidazolyl, quinoxalinimidazolyl, oxazolyl, benzoxoxazolyl, naphthoxazolyl, anthraquinoxazolyl, phenanthoxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridinyl, benzopyridinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthrayl, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenthiazinyl, naphridinyl, azacarbazolyl, benzocarbazolyl, phenanthrolinel, 1,2, One of 3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetraazinyl, 1,2,3,4-tetraazinyl, 1,2,3,5-tetraazinyl, purine, pteridine, indazinyl, benzothiadiazolyl, or a combination of the above two groups.

[0043] From the perspective of electron-rich electrons, Ar 1 and Ar 2 The components preferably contain S and O atoms, and the carbazole group is also generally preferred as it is electron-rich.

[0044] Ar is preferred in this invention 1 and Ar 2All are structures consisting of four or more ring structures arranged side-by-side and fused together. For example, Ar2 is preferably represented by the groups shown in formulas (a1-1) to (a1-9).

[0045]

[0046] Y 1 ~Y 8 Independently selected from CR 3 Or N, the R 3 Independently selected from hydrogen, halogen, cyano, nitro, hydroxyl, C6-C 60 aryl, C3~C 60 heteroaryl, C1-C 20 Alkyl groups, C1-C 20 alkoxy, amino, C1-C 20 Silyl, C6-C 60 arylamino, C3-C 60 One or a combination of heteroarylamino groups, wherein the R 3 Independently connected to an aromatic ring to form a ring or not connected to an aromatic ring; Z is S or O; here R 3 More preferably hydrogen or aryl.

[0047] Ar1 is preferably a group selected from those represented by the following formulas (a2-1) to (a2-9) and (a3-1) to (a3-9).

[0048]

[0049] X 9 ~X 24 Independently selected from CR 2 Or N, the R 2 Independently selected from hydrogen, halogen, cyano, nitro, hydroxyl, C6-C 60 aryl, C3~C 60 heteroaryl, C1-C 20 Alkyl groups, C1-C 20 alkoxy, amino, C1-C 20 Silyl, C6-C 60 arylamino, C3-C 60 One or a combination of heteroarylamino groups, wherein the R 2 Independently linked to an aromatic ring or heteroaromatic ring to form a ring, or not linked to form a ring, preferably R. 2 Independently selected from hydrogen, C6~C 30 Aryl, further preferred R 2 It is hydrogen.

[0050] Y 1 ~Y 8 Independently selected from CR3 Or N, the R 3 Independently selected from hydrogen, halogen, cyano, nitro, hydroxyl, C6-C 60 aryl, C3~C 60 heteroaryl, C1-C 20 Alkyl groups, C1-C 20 alkoxy, amino, C1-C 20 Silyl, C6-C 60 arylamino, C3-C 60 One or a combination of heteroarylamino groups, R 3 Preferably, it is a C1-C6 alkyl group selected from hydrogen, substituted or unsubstituted alkyl groups, R 3 Further preferred are hydrogen, C1-C3 alkyl groups, R 3 There are no connections between them; Z is either S or O.

[0051] via Ar 1 and Ar 2 The present invention provides superior luminous efficiency for the aforementioned structure, the reason for which is unclear, but is presumed to be due to the following principle: through the above-mentioned preferred Ar... 1 and Ar 2 The compounds provided by this invention are conformationally more suitable for forming π-conjugated bridges with distorted conformations, suppressing charge transfer between electron donor and acceptor units, thereby improving the overall molecular properties as described above. 1 Group, preferably the following groups,

[0052]

[0053] As such an Ar 2 Selected from the following groups, preferably the following groups,

[0054]

[0055] From the perspective of further improving luminous efficiency, the Ar of the present invention... 3 Among them, A is preferred. 1 ~A 5 Two of them are N atoms. In this case, a possible reason for the improved luminescence efficiency is that the bipolar host material requires a weaker interaction between the electron donor and acceptor to independently regulate the HOMO and LUMO energy levels, thereby ensuring the effect of a higher triplet energy level. When A... 1 ~A 5 When three or more of the atoms in Ar are N atoms, 3 Compounds that are too lacking in electrons to become strong electron acceptor groups are related to A. 1 ~A 5Compared to compounds with two nitrogen atoms, the latter exhibits slightly lower performance due to stronger charge transfer between electron donors and acceptors.

[0056] As such an Ar 3 The group, preferably, represents the group represented by (Ⅱ-1-1) or (Ⅱ-2-1) below.

[0057]

[0058] A 6 ~A 9 Independently selected from CR 5 Or N, R 5 Independently selected from hydrogen, halogen, cyano, nitro, hydroxyl, C6-C 60 aryl, C3~C 60 heteroaryl, C1-C 20 Alkyl groups, C1-C 20 alkoxy, amino, C1-C 20 Silyl, C6-C 60 arylamino, C3-C 60 One of the heteroarylamino groups or a combination of these groups.

[0059] Further preferably Ar 3 The group represents the group indicated in (Ⅱ-1-2) or (Ⅱ-2-2) below.

[0060]

[0061] A 6 ~A 9 The meaning expressed is the same as in claim 4, R 4 'and R 4 "Independently selected from hydrogen, halogen, cyano, nitro, hydroxyl, C6-C" 60 aryl, C3~C 60 heteroaryl, C1-C 20 Alkyl groups, C1-C 20 alkoxy, amino, C1-C 20 Silyl, C6-C 60 arylamino, C3-C 60 R is one or a combination of heteroarylamino groups. 4 'and R 4 "Preferably, it is one of the following groups: phenyl, biphenyl, terphenyl, dibenzofuranyl, dibenzothiophenyl, carbazoleyl."

[0062] More specifically, Ar 3 Further selected from the following groups,

[0063]

[0064] The following compounds can be cited as preferred specific compounds of the present invention, but the present invention is not limited to these compounds.

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074] In addition, the preparation process of the compound of the present invention is simple and easy, the raw materials are readily available, it is suitable for mass production and scale-up, and it is very suitable for industrial applications.

[0075] The compounds of the present invention have particularly excellent performance as host materials, and are especially suitable as host materials for phosphorescent luminescent layers, and are even more preferably used as host materials for red phosphorescent luminescent layers.

[0076] However, the application scenarios of the compounds of this invention are not limited to organic electroluminescent devices, but can also be used as the main material for other organic electronic devices, including but not limited to organic electroluminescent devices, optical sensors, solar cells, lighting elements, organic thin-film transistors, organic field-effect transistors, organic thin-film solar cells, information tags, electronic artificial skin sheets, sheet-type scanners, or electronic paper.

[0077] The present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising a first electrode, a second electrode, and at least one or more light-emitting functional layers inserted between the first electrode and the second electrode, wherein the light-emitting functional layers contain at least one compound described in the present invention. Detailed Implementation

[0078] The technical solution of the present invention will be further described in more detail below. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof.

[0079] Method for obtaining the compound of the present invention

[0080] The compounds represented by general formula I of this invention can be obtained by known methods, such as synthesis by known organic synthesis methods. Example synthetic routes are given below, but those skilled in the art can also obtain them by other known methods.

[0081] The synthetic route for the compound represented by general formula (I) of this invention is as follows:

[0082]

[0083] Wherein, X1-X8, Ar, and A1-A5 all have the same definition as the symbols in Formula I; by using different raw materials or customized intermediates of X1-X8, Ar, and A1-A5, the compounds of the present invention can generally be synthesized via the above-mentioned common route.

[0084] The following is a detailed description of organic electroluminescent devices.

[0085] An OLED device includes a first electrode and a second electrode, and an organic material layer located between the electrodes. This organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0086] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is typically made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, thin-film transistors (TFTs) can also be incorporated into the substrate used for displays.

[0087] The first electrode can be formed by sputtering or depositing the material to be used as the first electrode on a substrate. When the first electrode is used as the anode, it can be a transparent conductive oxide material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), or any combination thereof. When the first electrode is used as the cathode, it can be 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), or any combination thereof.

[0088] Organic material layers can be formed on electrodes using methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as organic material layers can be small organic molecules, large organic molecules, polymers, and combinations thereof.

[0089] The hole transport region is located between the anode and the emissive layer. The hole transport region can be a single-layer hole transport layer (HTL), including single-layer hole transport layers containing only one compound and single-layer hole transport layers containing multiple compounds. Alternatively, the hole transport region can be a multilayer structure including at least one 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 emissive layer.

[0090] The material for the hole transport region may be selected from, but is 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 as shown in HT-1 to HT-51 below; or any combination thereof.

[0091]

[0092]

[0093]

[0094] 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 be one or more compounds of HT-1 to HT-51 mentioned above, or one or more compounds of HI-1 to HI-3 mentioned below; it can also be one or more compounds of HT-1 to HT-51 doped with one or more compounds of HI-1 to HI-3 mentioned below.

[0095]

[0096] The emissive layer includes luminescent dyes (i.e., dopants) that can emit different wavelengths of light, and may also include a host material. The emissive layer can be a monochromatic emissive layer emitting a single color such as red, green, or blue. Multiple monochromatic emissive layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored emissive layer. When different colored emissive layers are stacked together, they can be separated from each other or connected to each other. The emissive layer can also be a single colored emissive layer that can simultaneously emit different colors such as red, green, and blue.

[0097] Depending on the technology used, the light-emitting layer material can be various, including fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescence materials. An OLED device can employ a single light-emitting technology or a combination of different technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0098] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0099]

[0100]

[0101] Where D represents deuterium.

[0102] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0103]

[0104] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0105]

[0106] 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 employ, but is not limited to, one or more compounds of HT-1 to HT-51 described above, or one or more compounds of PH-47 to PH-77 described below; or a mixture of one or more compounds of HT-1 to HT-51 and one or more compounds of PH-47 to PH-77 may be employed.

[0107]

[0108]

[0109] The OLED organic material layer may also include an electron transport region between the light-emitting layer and the cathode. The electron transport region can be a single-layer electron transport layer (ETL), including single-layer electron transport layers containing only one compound and single-layer electron transport layers containing multiple compounds. Alternatively, the electron transport region can be a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0110] In one aspect of the present invention, the electron transport layer material may be selected from, but not limited to, one or more combinations of ET-1 to ET-73 listed below.

[0111]

[0112]

[0113]

[0114]

[0115] 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 employ, but is not limited to, one or more compounds of ET-1 to ET-65 described above, or one or more compounds of PH-1 to PH-46 described below; or a mixture of one or more compounds of ET-1 to ET-73 and one or more compounds of PH-1 to PH-46 may be employed.

[0116]

[0117]

[0118]

[0119] The device may also include an electron injection layer located between the electron transport layer and the cathode, and the electron injection layer material includes, but is not limited to, one or more combinations of the following.

[0120] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Yb, Mg.

[0121] Example

[0122] The organic compounds of the present invention were synthesized in a representative manner and applied together with corresponding comparative compounds in organic electroluminescent devices to test the device performance under the same conditions.

[0123] Synthesis example

[0124] The present invention provides exemplary synthetic methods for representative compounds in the following synthetic examples. The solvents and reagents used in these examples, such as 2-fluoro-5-chlorophenylboronic acid, tris(dibenzylacetone)dipalladium(O), toluene, methanol, ethanol, tri-tert-butylphosphine, sodium tert-butyloxide, etc., can all be purchased from the domestic chemical product market or custom-made, for example, purchased from Sinopharm Reagent Company, Sigma-Aldrich, or Bailingwei Reagent Company. Alternatively, those skilled in the art can also synthesize these compounds using known methods.

[0125] Synthesis Example 1: Synthesis of Compound C1

[0126]

[0127] In a 1L single-necked flask, add 17.40g of 2-fluoro-5-chlorophenylboronic acid, 24.00g of 2-chloro-4-phenylquinazoline, and 27.60g of potassium carbonate, along with 400mL of toluene, 200mL of ethanol, and 200mL of water, and stir until homogeneous. Replace the air in the flask with nitrogen, then add 2.31g of Pd(PPh3)4. Under nitrogen protection, heat to 90℃ and react overnight. After monitoring for complete reaction, cool the mixture, pour the reaction solution into water, and extract with ethyl acetate until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain a brownish-red oily substance. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 6 / 1) to give a white solid M1.

[0128] In a 1L single-necked flask, add 16.70g M1, 10.85g 7H-benzocarbazole, and 14.47g cesium carbonate, then add 400ml DMF and stir until homogeneous. Replace the air in the flask with nitrogen, and under nitrogen protection, heat to 90℃ and react overnight. After monitoring for complete reaction, cool the mixture, pour it into water, and extract with dichloromethane until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 5 / 1) to give a pale yellow solid, M2.

[0129] In a 1L single-necked flask, 15.0g of compound M2, 7.97g of 7H-benzocarbazole, and 8.13g of sodium tert-butoxide, along with 600mL of toluene, were added. Under nitrogen protection, 1.31g of catalyst Pd2dba3 and 2mL of (t-Bu)3P were added, and the mixture was heated to reflux and reacted overnight. TLC was used to monitor complete reaction of the starting materials, and the mixture was then cooled to room temperature. The reaction solution was passed through a short silica gel column, eluented with toluene until no product was obtained. After concentration, a brownish-red oily substance was obtained. Column chromatography (using PE / DCM = 10 / 1 as eluent) yielded a pale yellow solid, Cl.

[0130] Theoretical M / Z value: 712.3; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 713.3.

[0131] Synthesis Example 2: Synthesis of Compound C3

[0132]

[0133] In a 1L single-necked flask, 15.0g of compound M2, 6.13g of carbazole, and 8.13g of sodium tert-butoxide, along with 600mL of toluene, were added. Under nitrogen protection, 1.31g of catalyst Pd2dba3 and 2mL of (t-Bu)3P were added, and the mixture was heated to reflux and reacted overnight. TLC was used to monitor the reaction until complete, and the mixture was then cooled to room temperature. The reaction solution was passed through a short silica gel column, eluented with toluene until no product was observed. After concentration, a brownish-red oily substance was obtained. Column chromatography (using PE / DCM = 10 / 1 as eluent) yielded a pale yellow solid, C3.

[0134] Theoretical M / Z value: 662.3; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 663.3.

[0135] Synthesis Example 3: Synthesis of Compound C6

[0136]

[0137] In a 1L single-necked flask, 15.0g of compound M2, 8.92g of 3-phenylcarbazole, and 8.13g of sodium tert-butoxide, along with 600mL of toluene, were added. Under nitrogen protection, 1.31g of catalyst Pd2dba3 and 2mL of (t-Bu)3P were added, and the mixture was heated to reflux and reacted overnight. TLC was used to monitor complete reaction of the starting materials, and the mixture was then cooled to room temperature. The reaction solution was passed through a short silica gel column, eluented with toluene until no product was observed. After concentration, a brownish-red oily substance was obtained. Column chromatography (using PE / DCM = 8 / 1 as eluent) yielded a pale yellow solid, C6.

[0138] Theoretical M / Z value: 738.3; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 739.3.

[0139] Synthesis Example 4: Synthesis of Compound C13

[0140]

[0141] In a 1L single-necked flask, 15.0g of compound M2, 9.62g of naphtho[2,3-b]benzofuran-2-boric acid, and 8.13g of sodium tert-butoxide were added, along with 600mL of toluene. Under nitrogen protection, 1.31g of catalyst Pd2dba3 and 2mL of (t-Bu)3P were added, and the mixture was heated to reflux and reacted overnight. TLC was used to monitor the reaction until complete, and the mixture was cooled to room temperature. The reaction solution was passed through a short silica gel column, eluented with toluene until no product was obtained. After concentration, a brownish-red oily substance was obtained. Column chromatography (using PE / DCM = 6 / 1 as eluent) yielded a pale yellow solid, C13.

[0142] Theoretical M / Z value: 713.3; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 714.3.

[0143] Synthesis Example 5: Synthesis of Compound C45

[0144]

[0145] In a 1L single-necked flask, add 16.70g M1, 13.35g 7H-dibenzo[c,g]carbazole, and 14.47g cesium carbonate, then add 400mL DMF and stir until homogeneous. Replace the air in the flask with nitrogen, and under nitrogen protection, heat to 90℃ and react overnight. After monitoring for complete reaction, cool the mixture, pour it into water, and extract with dichloromethane until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 5 / 1) to give a pale yellow solid, M3.

[0146] In a 1L single-necked flask, 15.0g of compound M3, 8.63g of 12H-benzofuran[2,3-a]carbazole, and 7.43g of sodium tert-butoxide, along with 600mL of toluene, were added. Under nitrogen protection, 1.19g of catalyst Pd2dba3 and 2mL of (t-Bu)3P were added, and the mixture was heated to reflux and reacted overnight. TLC was used to monitor the reaction until complete, and the mixture was cooled to room temperature. The reaction solution was passed through a short silica gel column, eluented with toluene until no product was observed. After concentration, a brownish-red oily substance was obtained. Column chromatography (using PE / DCM = 9 / 1 as eluent) yielded a pale yellow solid, C45.

[0147] Theoretical M / Z value: 802.3; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 803.3.

[0148] Synthesis Example 6: Synthesis of Compound C65

[0149]

[0150] In a 1L single-necked flask, add 16.70g M1, 12.85g 12H-benzofuran[2,3-a]carbazole, and 14.47g cesium carbonate, then add 400mL DMF and stir until homogeneous. Replace the air in the flask with nitrogen, and under nitrogen protection, heat to 90℃ and react overnight. After monitoring for complete reaction, cool the mixture, pour it into water, and extract with dichloromethane until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 6 / 1) to give a pale yellow solid, M4.

[0151] In a 1L single-necked flask, 15.00g of compound M4, 8.78g of 12H-benzofuran[2,3-a]carbazole, and 7.56g of sodium tert-butoxide, along with 600mL of toluene, were added. Under nitrogen protection, 1.21g of catalyst Pd2dba3 and 2mL of (t-Bu)3P were added, and the mixture was heated to reflux and reacted overnight. TLC was used to monitor complete reaction of the starting materials, and the mixture was then cooled to room temperature. The reaction solution was passed through a short silica gel column, eluented with toluene until no product was observed. After concentration, a brownish-red oily substance was obtained. Column chromatography (using PE / DCM = 10 / 1 as eluent) yielded a pale yellow solid, C65.

[0152] Theoretical M / Z value: 792.3; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 793.3.

[0153] Synthesis Example 7: Synthesis of Compound C97

[0154]

[0155] In a 1L single-necked flask, add 17.40g of 2-fluoro-5-chlorophenylboronic acid, 24.00g of 2-chloro-3-phenylquinoxaline, and 27.60g of potassium carbonate, along with 400mL of toluene, 200mL of ethanol, and 200mL of water, and stir until homogeneous. Replace the air in the flask with nitrogen, then add 2.31g of Pd(PPh3)4. Under nitrogen protection, heat to 90℃ and react overnight. After monitoring for complete reaction, cool the mixture, pour the reaction solution into water, and extract with ethyl acetate until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain a brownish-red oily substance. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 8 / 1) to give a white solid M5.

[0156] In a 1L single-necked flask, add 16.70g M5, 10.85g 7H-benzocarbazole, and 14.47g cesium carbonate, along with 400ml LDM, and stir until homogeneous. Replace the air in the flask with nitrogen, and under nitrogen protection, heat to 90°C and react overnight. After monitoring for complete reaction, cool the mixture, pour it into water, and extract with dichloromethane until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 7 / 1) to give a pale yellow solid, M6.

[0157] In a 1L single-necked flask, 15.0g of compound M6, 7.97g of 7H-benzocarbazole, and 8.13g of sodium tert-butoxide, along with 600mL of toluene, were added. Under nitrogen protection, 1.31g of catalyst Pd₂dba₃ and 2mL of (t-Bu)₃P were added, and the mixture was heated to reflux and reacted overnight. TLC was used to monitor complete reaction of the starting material, and the mixture was then cooled to room temperature. The reaction solution was passed through a short silica gel column, eluented with toluene until no product was obtained. After concentration, a brownish-red oily substance was obtained. Column chromatography (using PE / DCM = 10 / 1 as eluent) yielded a pale yellow solid, C97.

[0158] Theoretical M / Z value: 712.3; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 713.3.

[0159] Synthesis Example 8: Synthesis of Compound C134

[0160]

[0161] In a 1L single-necked flask, add 17.40g of 2-fluoro-5-chlorophenylboronic acid, 29.60g of 2-chloro-4-phenylbenzo[4,5]thiophene[3,2-d]pyrimidine, and 27.60g of potassium carbonate. Add 400mL of toluene, 200mL of ethanol, and 200mL of water, and stir until homogeneous. Replace the air in the flask with nitrogen, then add 2.31g of Pd(PPh3)4. Under nitrogen protection, heat to 90°C and react overnight. After monitoring the reaction to completion, cool down, pour the reaction solution into water, and extract with ethyl acetate until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain a brownish-red oily substance. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 6 / 1) to give a white solid M7.

[0162] In a 1L single-necked flask, add 19.50g M7, 10.85g 7H-benzocarbazole, and 14.47g cesium carbonate, along with 400ml LDM, and stir until homogeneous. Replace the air in the flask with nitrogen, and under nitrogen protection, heat to 90°C and react overnight. After monitoring for complete reaction, cool the mixture, pour it into water, and extract with dichloromethane until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 6 / 1) to give a pale yellow solid, M8.

[0163] In a 1L single-necked flask, 15.0g of compound M8, 7.21g of 7H-benzocarbazole, and 7.36g of sodium tert-butoxide, along with 600mL of toluene, were added. Under nitrogen protection, 1.18g of catalyst Pd₂dba₃ and 2mL of (t-Bu)₃P were added, and the mixture was heated to reflux and reacted overnight. TLC was used to monitor complete reaction of the starting materials, and the mixture was then cooled to room temperature. The reaction solution was passed through a short silica gel column, eluented with toluene until no product was obtained. After concentration, a brownish-red oily substance was obtained. Column chromatography (using PE / DCM = 9 / 1 as eluent) yielded a yellow solid, C134.

[0164] Theoretical M / Z value: 768.2; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 769.2.

[0165] Synthesis Example 9: Synthesis of Compound C169

[0166]

[0167] In a 1L single-necked flask, add 15.8g of 2,5-difluorophenylboronic acid, 26.71g of 2-chloro-4,6-diphenyl-1,3,5-triazine, 27.4g of potassium carbonate, and 2.26g of Pd(PPh3)4, along with 400mL of toluene, 200mL of ethanol, and 200mL of water. Stir until homogeneous. Under nitrogen protection, heat to 90℃ and react overnight. After monitoring for complete reaction, cool the mixture, pour the reaction solution into water, and extract with ethyl acetate until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify by column chromatography (petroleum ether / dichloromethane, 9 / 1) to give a white solid M9.

[0168] In a 1L single-necked flask, add 17.26g M9, 28.28g 7H-benzofuran[2,3-b]carbazole, and 19.29g cesium carbonate, then add 500mL DMF and stir until homogeneous. Under nitrogen protection, heat to 100℃ and react overnight. After monitoring the reaction to ensure completeness, cool down, pour the reaction solution into water, and extract with dichloromethane until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 6 / 1) to give a yellow solid C169.

[0169] Theoretical M / Z value: 819.3; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 820.2.

[0170] Synthesis Example 10: Synthesis of Compound R1

[0171]

[0172] In a 1L single-necked flask, add 7.9g of 2,3-difluorophenylboronic acid, 17.11g of 2-phenyl-4-(1,1'-diphenyl-4-)-6-chloropyrimidine, 13.7g of potassium carbonate, and 1.13g of Pd(PPh3)4. Add 300mL of toluene, 100mL of ethanol, and 100mL of water, and stir until homogeneous. Under nitrogen protection, heat to 90℃ and react overnight. After monitoring the reaction to ensure completeness, cool down, pour the reaction solution into water, and extract with ethyl acetate until no product is found in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify by column chromatography (petroleum ether / dichloromethane, 9 / 1) to give a white solid M10.

[0173] In a 1L single-necked flask, add 21.0g M10, 23.88g 7H-benzocarbazole, and 19.29g cesium carbonate, then add 500ml LDM and stir until homogeneous. Under nitrogen protection, heat to 100℃ and react overnight. After monitoring for complete reaction, cool down, pour the reaction solution into water, and extract with dichloromethane until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 6 / 1) to give a yellow solid C169.

[0174] Theoretical M / Z value: 814.3; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 815.3.

[0175] Synthesis Example 11: Synthesis of Compound R2

[0176]

[0177] In a 1L single-necked flask, 17.40g of 2-chloro-5-fluorophenylboronic acid, 24.00g of 2-chloro-4-phenylquinazoline, and 27.60g of potassium carbonate were added, along with 400mL of toluene, 200mL of ethanol, and 200mL of water. The mixture was stirred until homogeneous. Under nitrogen protection, 2.31g of Pd(PPh3)4 was added, and the mixture was heated to 100℃ and reacted overnight. After the reaction was monitored to be complete, the temperature was lowered, the reaction solution was poured into water, and extracted with ethyl acetate. The organic phases were combined and concentrated to obtain the crude product. The crude product was purified by column chromatography (petroleum ether / dichloromethane, 6 / 1) to give a white solid, M11.

[0178] In a 1L single-necked flask, add 16.70g M1, 8.35g carbazole, and 14.47g cesium carbonate, then add 300mL DMF and stir until homogeneous. Under nitrogen protection, heat to 90℃ and react overnight. After monitoring the reaction to ensure completeness, cool down, pour the reaction solution into water, and extract with dichloromethane until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 6 / 1) to obtain intermediate M12.

[0179] In a 1L single-necked flask, 16.04g of compound M12, 9.67g of 9-phenylcarbazole-3-boric acid, and 6.40g of sodium tert-butoxide, along with 400mL of toluene, were added. Under nitrogen protection, 1.61g of Pd2dba3 and 3mL of (t-Bu)3P were added, and the mixture was heated to reflux and reacted overnight. TLC was used to monitor complete reaction of the starting materials, and the mixture was then cooled to room temperature. The reaction solution was passed through a short silica gel column, eluented with toluene until no product was observed. After concentration, a crude oily product was obtained. This product was purified by column chromatography (eluting with PE / DCM = 9 / 1) to give a yellow solid, R2.

[0180] Theoretical M / Z value: 688.3; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 689.3.

[0181] Synthesis Example 12: Synthesis of Compound R3

[0182]

[0183] In a 1L single-necked flask, add 14g of 2-fluorophenylboronic acid, 24g of 2-chloro-4-phenylquinazoline, and 27.60g of potassium carbonate, along with 400mL of toluene, 200mL of ethanol, and 200mL of water, and stir until homogeneous. Under nitrogen protection, add 2.31g of Pd(PPh3)4, and heat to 100℃ to react overnight. After monitoring the reaction to completion, cool the mixture, pour the reaction solution into water, extract with ethyl acetate, combine the organic phases, and concentrate to obtain the crude product. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 6 / 1) to obtain M13.

[0184] In a 1L single-necked flask, add 15g M13, 16.60g 9-phenyl-[2,3-c]indolocarbazole, and 16.29g cesium carbonate, then add 300mL DMF and stir until homogeneous. Under nitrogen protection, heat to 90℃ and react overnight. After monitoring the reaction to ensure completeness, cool down, pour the reaction solution into water, and extract with dichloromethane until no product remains in the aqueous phase. Combine the organic phases and concentrate to obtain the crude product. Purify the crude product by column chromatography (petroleum ether / dichloromethane, 9 / 1) to give compound R3.

[0185] Theoretical M / Z value: 612.2; Actual M / Z value of ZAB-HS mass spectrometer (manufactured by Micromass, UK): 613.2.

[0186] Device Example 1

[0187] This embodiment 1 provides a method for fabricating an organic electroluminescent device, as detailed below:

[0188] The glass plate coated with an ITO transparent conductive layer (as the anode) 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 all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0189] The glass substrate with the anode was placed in a vacuum chamber and evacuated to a vacuum level of less than 1 × 10⁻⁶. -5 Pa, a mixture of HT-4:HI-3 (97 / 3, w / w) was vacuum-deposited on the above anodic layer as a hole injection layer at a deposition rate of 0.1 nm / s and a film thickness of 10 nm.

[0190] HT-4 was vacuum-deposited on top of the hole injection layer as the hole transport layer of the device at a deposition rate of 0.1 nm / s and a total film thickness of 60 nm.

[0191] HT-48 was vacuum-deposited on the hole transport layer as the electron blocking layer material of the device at a deposition rate of 0.1 nm / s and a total film thickness of 40 nm.

[0192] The light-emitting layer of the device is vacuum-deposited on top of the electron blocking layer. The light-emitting layer includes a host material and a dye material. Using a multi-source co-evaporation method, compound C1 is used as the host material, and its evaporation rate is adjusted to 0.1 nm / s. The evaporation rate of dye RPD-19 is set to 3% of that of the host material. The total film thickness is 40 nm.

[0193] ET-23 was vacuum-deposited on the light-emitting layer as a hole-blocking layer material for the device, with a deposition rate of 0.1 nm / s and a total film thickness of 5 nm.

[0194] The electron transport layer materials ET-69 and ET-57 of the device are vacuum-deposited on the hole blocking layer in a mass ratio of 1:1. The deposition rate is 0.1 nm / s and the total film thickness is 25 nm.

[0195] A 0.5 nm thick LiF layer was vacuum-deposited on the electron transport layer (ETL) as the electron injection layer, and a 150 nm thick Al layer was used as the cathode of the device.

[0196] Device Examples 2-8

[0197] The only difference from Device Example 1 is that the main compound C1 used in the light-emitting layer is replaced with other compounds of the present invention, as detailed in Table 1.

[0198] The fabrication process of the organic electroluminescent devices provided in Comparative Examples 1 and 2 is the same as that in Example 1, except that the main compound C1 used in the light-emitting layer is replaced with compounds R1 and R2, respectively. The specific structural formulas of the compounds are as described in the synthesis example.

[0199] Performance testing:

[0200] (1) Under the same brightness, the driving voltage, current efficiency, and lifetime of the organic electroluminescent devices prepared in the examples and comparative examples were measured using a digital source meter (Keithley 2400) and a luminance meter (ST-86LA type luminance meter, Beijing Normal University Optoelectronic Instrument Factory). Specifically, the voltage was increased at a rate of 0.1V per second, and the measurement was performed when the brightness of the organic electroluminescent device reached 5000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency.

[0201] (2) The lifespan test of LT97 is as follows: using a luminance meter at 5000 cd / m 2 Under constant current, the time it takes for the brightness of an organic electroluminescent device to drop to 97% is measured in hours.

[0202] The performance test results are shown in Table 1. The lifetime of the device comparative example 1 was set to 1.0, and the lifetime performance of the other materials were all ratios to it.

[0203] Table 1:

[0204]

[0205]

[0206] As can be seen from the data in Table 1, when the material schemes and fabrication processes of other functional layers in the organic electroluminescent device structure are completely identical, the compound of the present invention, when used as the main material of the light-emitting layer in an organic electroluminescent device, achieves a device brightness of 5000 cd / m². 2 When the driving voltage is as low as below 4.2V, the current efficiency is as high as 18cd / A or more, and the LT97 reaches more than 18h. The performance of the comparative device using the compound in the prior art as the light-emitting host material is significantly improved. It can be seen that the device using the compound of the present invention has significant performance advantages in improving current efficiency and extending device life. The compound of the present invention is indeed a high-performance light-emitting layer host material.

[0207] The compound R1 used in Comparative Example 1 differs from the compound described in this invention in that the position of the electron-donating group is different. In this invention, an electron-donating group is introduced at the adjacent position of the electron acceptor group to form a π-conjugated bridge with a distorted conformation. This connection method suppresses charge transfer between the electron donor and acceptor units, making them relatively independent and thus effectively improving device performance.

[0208] The compound R2 used in Comparative Example 2 differs from the compound described in this invention in that the position of the electron-accepting group is different. The HOMO energy level of compound R4 is distributed on the 9-carbazole linker, while the LUMO energy level is distributed on the electron-accepting quinazoline group. This connection method cannot effectively suppress charge transfer between the electron donor and acceptor units and fails to form a π-conjugated bridge with a distorted conformation, making the two relatively independent. As a result, the performance of R4 is lower than that of the compound described in this invention.

[0209] The experimental data above show that the novel organic material of this invention, through the rational selection and position design of electron-donating and electron-accepting units, results in a weaker interaction between its electron-donating and electron-accepting groups when used as the main light-emitting material of organic electroluminescent devices. This is a significant improvement over existing technologies, making it a high-performance organic light-emitting functional material with more balanced application performance and broad application prospects.

[0210] The present invention has been illustrated with the above embodiments to explain the detailed method of the present invention. However, the present invention is not limited to the detailed method described above, that is, it does not mean that the present invention must rely on the detailed method described above to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the 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. An organic compound, characterized in that, It has the structure shown in equation (I); Ar 1 Selected from the following groups, Ar 2 Selected from the following groups, Ar 3 Selected from the following groups, ; The wavy line indicates that it is bonded to other groups at this position.

2. The compound according to claim 1, wherein, Ar 3 Selected from the following groups, 。 3. Compounds having the structure shown below:

4. The application of the compound according to any one of claims 1 to 3 as the host material of the light-emitting layer in an organic electroluminescent device.

5. A host material for a phosphorescent light-emitting layer in an organic electroluminescent device, comprising any one of claims 1 to 3.

6. An organic electroluminescent device, characterized in that, The main material of its light-emitting layer is any one of the compounds described in claims 1 to 3.

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