A compound and its application

Abstract

The present invention relates to a compound and application thereof. The compound has a structure shown in Formula I. The compound provided by the present invention is an 8-membered aromatic octane ring structure containing an N heteroatom, and L1-Ar1 is substituted on N. The molecule has a high hole mobility and sufficient triplet energy levels. When applied to an OLED device, the device efficiency can be effectively improved and the driving voltage can be reduced. The compound is a good host material, in particular a good red light host material.

Description

Technical Field

[0001] The invention relates to the technical field of organic electroluminescence, and in particular to a compound and application thereof. Background Art

[0002] In recent years, organic light-emitting diodes (OLEDs) have developed rapidly and have occupied a place in the field of information display. This is mainly due to the fact that OLED devices can use the three primary colors of red, green and blue with high saturation to prepare full-color display devices, and do not require additional backlight sources to achieve colorful, light, thin and soft performance.

[0003] The thin layer structure containing a variety of organic functional materials plays an important role in OLED devices. Common organic functional materials include light-emitting layer materials, electron blocking layer materials, electron transport layer materials, hole blocking layer materials, hole transport layer materials, etc. After the power is turned on, electrons and holes are respectively injected and transported to the light-emitting layer, where they recombine to generate excitons and realize light emission. Therefore, the research on organic functional materials in OLED devices is a key research topic for those skilled in the art.

[0004] At present, researchers have developed a variety of organic functional materials for use in various specific device structures, which can improve carrier mobility, regulate carrier balance, break through electroluminescence efficiency, and delay device attenuation.

[0005] Common fluorescent luminescent bodies mainly emit light by utilizing singlet excitons generated when holes and electrons recombine, and such luminescent bodies are still used in various OLED devices. In addition, phosphorescent luminescent bodies are also included, i.e., materials that can simultaneously utilize triplet excitons and singlet excitons to emit light, such as iridium complexes. What is most noteworthy is that thermally excited delayed fluorescence (TADF) technology can effectively utilize triplet excitons to achieve higher luminescence efficiency without using metal complexes by promoting the transformation of triplet excitons to singlet excitons. Thermally excited sensitized fluorescence (TASF) technology uses TADF materials to sensitize luminescent bodies through energy transfer to achieve higher luminescence efficiency. TADF materials have broad application prospects in the field of OLEDs.

[0006] Although a variety of organic functional layer materials have been developed, people nowadays have increasingly higher requirements for the performance of OLED devices, and existing organic functional materials are no longer suitable for new OLED devices with higher performance.

[0007] Therefore, it is urgent to develop more types of organic functional materials in this field so that when they are applied to OLED devices, they can improve the luminous efficiency, reduce the driving voltage, and extend the service life. Summary of the invention

[0008] In view of the shortcomings of the prior art, one of the purposes of the present invention is to provide a compound, in particular to provide a main material for a light-emitting layer, which can improve the light-emitting efficiency and reduce the driving voltage when applied to an OLED device.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] The present invention provides a compound having a structure shown in Formula I;

[0011]

[0012] In formula I, Y is selected from N-L2-Ar2, O or S;

[0013] Ar1 and Ar2 are each independently selected from any one of a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 arylamino group, a substituted or unsubstituted C3-C30 heteroarylamino group, and a substituted or unsubstituted C3-C30 heteroaryl group;

[0014] The L1 and L2 are each independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C3-C30 heteroarylene group;

[0015] In Formula I, the X 1 -X 12 are each independently selected from N or CR;

[0016] The R are each independently selected from any one of hydrogen, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C10 silyl, amino, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C3-C30 heteroaryl; the two R substituted in the ortho position are not connected or connected to form a ring structure, and the ring structure is selected from any one of a monocyclic aliphatic ring, a condensed aliphatic ring, a monocyclic aliphatic heterocycle, a condensed aliphatic heterocycle, a monocyclic aromatic ring, a condensed aromatic ring, a monocyclic heteroaromatic ring or a condensed heteroaromatic ring; the ring structure formed by the two Rs is fused to the parent nucleus. Exemplarily, when two adjacent Rs are connected to form a benzene ring, the benzene ring is fused to the parent nucleus;

[0017] When there are at least two R, the at least two R may be the same or different;

[0018] In Ar1, Ar2, L1, L2 and R, the substituted groups are each independently selected from one or a combination of at least two of amino, cyano, halogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C6 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, and C3-C30 heteroaryl.

[0019] The compound provided by the present invention is an 8-membered aromatic octane ring structure containing a N heteroatom, and L1-Ar1 is substituted on N. This type of molecule has a high hole mobility and sufficient T1 (triplet energy level). When applied to OLED devices, it can effectively improve the device efficiency and reduce the driving voltage. It is a good host material, especially a good red light host material.

[0020] In the present invention, "substituted group" refers to the range of substituents selected when a "substituted or unsubstituted" group is substituted. The number is not specifically limited as long as the compound bond requirements are met. For example, it can be 1, 2, 3, 4 or 5, and when the number of substituents is 2 or more, these 2 or more substituents may be the same or different.

[0021] In the present invention, halogen represents a chlorine atom, a fluorine atom, a bromine atom or the like.

[0022] In the present invention, the expression of Ca to Cb represents that the number of carbon atoms in the group is a to b. Unless otherwise specified, the number of carbon atoms in the group generally does not include the number of carbon atoms in the substituent.

[0023] In the present invention, the aryl group includes a monocyclic aryl group or a condensed-ring aryl group, and the heteroaryl group includes a monocyclic heteroaryl group or a condensed-ring heteroaryl group.

[0024] Wherein, a monocyclic aromatic 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 a single bond.

[0025] A fused ring aromatic group refers to a molecule containing at least two benzene rings, but the benzene rings are not independent of each other, but are fused to each other by sharing the ring edges;

[0026] A monocyclic heteroaryl group refers to a molecule containing at least one heteroaryl group. When the molecule contains a heteroaryl group and other groups (such as aryl, heteroaryl, alkyl, etc.), the heteroaryl group and the other groups are independent of each other and connected by a single bond.

[0027] The fused heteroaryl group refers to a group formed by condensing at least one phenyl group and at least one heteroaryl group, or a group formed by condensing at least two heteroaryl rings.

[0028] The heteroatoms in the heteroaryl group described in the present invention generally refer to atoms or atomic groups selected from N, O, S, P, Si and Se, preferably selected from N, O and S. The names of atoms described in the present invention include their corresponding isotopes. For example, hydrogen (H) includes 1 H (hydrogen or H), 2 H (deuterium or D), etc.; Carbon (C) includes 12 C. 13 C, etc.

[0029] In the present invention, the carbon number of the C6-C30 (sub)aryl group can be C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, etc., and is exemplarily selected from the following groups: phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthrenyl, indenyl, fluorenyl and its derivatives, fluoranthenyl, triphenylene, pyrenyl, peryl, or tetraphenyl. 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, m-terphenyl-4-yl, m-terphenyl-3-yl and m-terphenyl-2-yl; the naphthyl group includes 1-naphthyl and 2-naphthyl; the anthracenyl group is selected from 1-anthracenyl, 2-anthracenyl and 9-anthracenyl; the fluorenyl group is selected from 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl and 9-fluorenyl; the fluorenyl derivative is selected from 9,9-dimethylfluorene, 9,9-spirobifluorene and benzofluorene; the pyrenyl group is selected from 1-pyrenyl, 2-pyrenyl and 4-pyrenyl; the tetraphenyl group is selected from 1-tetraphenyl, 2-tetraphenyl and 9-tetraphenyl.

[0030] In the present invention, C6-C30 arylamino represents a group formed by replacing hydrogen on an amino group with one or two C6-C30 aryl groups, wherein the connection point of the C6-C30 arylamino can be connected to the aryl group in the arylamino group, or can be connected to N in the arylamino group, and the exemplary carbon number and specific group of the C6-C30 aryl group in the C6-C30 arylamino group are the same as described above.

[0031] In the present invention, the number of carbon atoms in the C3-C30 heteroaryl group may be C4, C5, C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, etc., and is exemplarily selected from the following groups: furyl, thienyl, pyrrolyl, benzofuranyl, benzothienyl, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothienyl, carbazolyl and derivatives thereof, wherein the carbazolyl derivative is preferably 9-phenylcarbazole, 9-naphthylcarbazole, benzocarbazole, dibenzocarbazole, or indolecarbazole.

[0032] In the present invention, C3-C30 (sub)heteroarylamino represents a group formed by replacing the hydrogen on the amino group with one or two C3-C30 heteroaryl groups, wherein the connection point of the C3-C30 heteroarylamino can be connected to the heteroaryl in the heteroarylamino, and can also be connected to the N in the heteroarylamino, and the exemplary carbon number and specific group of the C3-C30 heteroaryl in the C3-C30 heteroarylamino are the same as described above.

[0033] In the present invention, the number of carbon atoms in the C1-C10 chain alkyl group may be C1, C2, C3, C4, C5, C6, C7, C8, C9, etc., and examples thereof include methyl, ethyl, n-propyl, n-butyl, n-hexyl, n-octyl, isopropyl, isobutyl, tert-butyl, etc.

[0034] In the present invention, the number of carbon atoms in the C3-C10 cycloalkyl group may be C4, C5, C6, C7, C8, C9, etc., and examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl.

[0035] In the present invention, the number of carbon atoms in the C1-C10 silane group may be C1, C2, C3, C4, C5, C6, C7, C8, C9, etc., and examples thereof include methylsilane, ethylsilane, isopropylsilane, tert-butylsilane, phenylsilane, and the like.

[0036] Preferably, the compound has the structure shown in Formula II;

[0037]

[0038] In Formula II, Ar1, L1 and Y have the same selection range as in Formula I.

[0039] The present invention preferably 1 -X 12 All of them are CR, and R is selected from the structure of hydrogen (Formula II). This is because when R is hydrogen, the structure is rigid and the material instability factor is low. Furthermore, there is no branched substituent, which makes the molecular planarity and film-forming properties better, which is beneficial to the transmission of carriers, thereby further improving the luminous efficiency of the device and reducing the driving voltage.

[0040] Preferably, Ar1 and Ar2 are each independently selected from any one of a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 arylamino group, preferably any one of a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted fluorenyl group, and a substituted or unsubstituted diphenylamino group.

[0041] In a preferred technical solution of the present invention, the substituents (Ar1 and Ar2) on N are both substituted or unsubstituted C6-C30 aromatic groups or substituted or unsubstituted C6-C30 aromatic amino groups. This structure serves as a hole-type host in a dual-host device structure. The introduction of aromatic groups and aromatic amino groups plays a role in regulating the HOMO energy level of the molecule, thereby changing the hole transport energy of the entire molecule to match the electronic host material, thereby enabling the device to have excellent luminous efficiency and driving voltage.

[0042] Preferably, at least one of Ar1 and Ar2 is selected from a substituted or unsubstituted C3-C30 heteroaryl group, preferably a substituted or unsubstituted C3-C30 electron-withdrawing heteroaryl group.

[0043] In the present invention, electron-withdrawing heteroaryl refers to a group whose electron cloud density on the benzene ring is reduced after the group replaces the hydrogen on the benzene ring, and the Hammett value of such a group is usually greater than 0.6. The Hammett value refers to the characterization of the charge affinity of a specific group. The Hammett equation is described in more detail in Thomas H.Lowry and KatheleenSchueller Richardson, "Mechanism and Theory In Organic Chemistry', New York, 1987, pp. 143-151, which is cited herein as a reference. Such groups can be listed but are not limited to: triazine, pyrimidine, benzopyrimidine, benzopyridinyl, naphthyl, phenanthroline, pyrazinyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, pyridazinyl, and the above-mentioned groups substituted with alkyl or aryl.

[0044] Preferably, Y is O or S, and Ar1 is selected from substituted or unsubstituted C3-C30 heteroaryl groups, preferably substituted or unsubstituted C3-C30 electron-withdrawing heteroaryl groups.

[0045] Preferably, Y is N-L2-Ar2, and at least one of Ar1 and Ar2 is selected from substituted or unsubstituted C3-C30 electron-withdrawing heteroaryl, preferably there is only one selected from substituted or unsubstituted C3-C30 electron-withdrawing heteroaryl.

[0046] The present invention preferably has at least one electron-withdrawing heteroaromatic group on the N of the parent core, which can balance the transmission of electrons and holes and further improve the device performance when used alone as a bipolar host.

[0047] Preferably, Y is N-L2-Ar2, Ar1 is selected from substituted or unsubstituted C3-C30 electron-withdrawing heteroaryl groups, and Ar2 is selected from substituted or unsubstituted C6-C30 aryl groups.

[0048] Preferably, the substituted or unsubstituted C3-C30 electron-withdrawing heteroaryl group includes any one of a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidyl group, a substituted or unsubstituted triazine group, a substituted or unsubstituted quinazolinyl group, and a substituted or unsubstituted quinoxalinyl group.

[0049] Preferably, in Ar1 and Ar2, the substituted groups are each independently selected from any one or a combination of at least two of phenyl, naphthyl, cyano, methyl, tert-butyl or methoxy.

[0050] Preferably, L1 and L2 are each independently selected from any one of a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, and a substituted or unsubstituted pyridylene group.

[0051] Preferably, the compound has any one of the structures described in P1 to P122 below:

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060] The second object of the present invention is to provide an application of the compound described in the first object, wherein the compound is applied to an organic electroluminescent device, preferably a red organic electroluminescent device.

[0061] Preferably, the compound is used as a host material of the organic electroluminescent device, preferably a red light host material.

[0062] The third object of the present invention is to provide an organic electroluminescent device, comprising a first electrode, a second electrode and at least one organic layer inserted between the first electrode and the second electrode, wherein the organic layer contains at least one compound described in one of the objects.

[0063] Preferably, the organic layer comprises a light-emitting layer, and the light-emitting layer comprises at least one compound described in one of the purposes.

[0064] Preferably, the light-emitting layer comprises a host material and a doping material, and the doping material comprises at least one compound described in one of the purposes.

[0065] In a specific embodiment, the organic layer may further include a hole transport region and an electron transport region.

[0066] In one embodiment, a substrate may be used below the first electrode or above the second electrode. The substrate is a glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a thin film transistor (TFT) may also be provided on the substrate used as a display.

[0067] The first electrode can be formed by sputtering or depositing the material used as the first electrode on the substrate. When the first electrode is used as an anode, an oxide transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as a cathode, a metal or alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0068] The organic layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, etc. The compound used as the organic layer can be an organic small molecule, an organic macromolecule, a polymer, and a combination thereof.

[0069] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a hole transport layer (HTL) of a single-layer structure, including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multi-layer structure including at least one layer of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0070] The material of the hole transport region can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives, wherein the aromatic amine derivatives include compounds shown in HT-1 to HT-50 below; or any combination thereof.

[0071]

[0072]

[0073]

[0074] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more compounds of HT-1 to HT-34 mentioned above, or one or more compounds of HI-1 to HI-3 below; or one or more compounds of HT-1 to HT-34 can be doped with one or more compounds of HI-1 to HI-3 below.

[0075]

[0076] The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit different wavelength spectra, and may also include a host material (Host). The light-emitting layer can be a monochrome light-emitting layer that emits a single color such as red, green, and blue. A plurality of monochrome light-emitting layers of different colors can be arranged in a plane according to a pixel pattern, or they can be stacked together to form a color light-emitting layer. When light-emitting layers of different colors are stacked together, they can be separated from each other or connected to each other. The light-emitting layer can also be a single color light-emitting layer that can simultaneously emit different colors such as red, green, and blue.

[0077] According to different technologies, the light-emitting layer material can be made of different materials such as fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescent materials. In an OLED device, a single light-emitting technology can be used, or a combination of multiple different light-emitting technologies can be used. These different light-emitting materials classified by technology can emit light of the same color or different colors.

[0078] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0079]

[0080]

[0081] The electron transport region may be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region may also be a multi-layer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0082] In one aspect of the present invention, the electron transport layer material can be selected from, but not limited to, one or more combinations of ET-1 to ET-65 listed below.

[0083]

[0084]

[0085]

[0086]

[0087] The device may further include an electron injection layer located between the electron transport layer and the cathode. Materials for the electron injection layer include, but are not limited to, one or more combinations of the following.

[0088] Liq, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Yb.

[0089] The cathode is a metal such as a magnesium-silver mixture, LiF / Al, ITO, a metal mixture, or an oxide.

[0090] Compared with the prior art, the present invention has the following beneficial effects:

[0091] The compound provided by the present invention is an 8-membered aromatic octane ring structure containing a N heteroatom, and L1-Ar1 is substituted on N. This type of molecule has a high hole mobility and sufficient T1 (triplet energy level). When applied to OLED devices, it can effectively improve the device efficiency and reduce the driving voltage. It is a good host material, especially a good red light host material. DETAILED DESCRIPTION

[0092] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0093] The representative synthesis route of the compound of general formula I of the present invention is as follows:

[0094]

[0095] The above symbols have the same meanings as in Formula I.

[0096] The synthesis method of intermediates M1-M7 is as follows:

[0097] Synthesis of intermediate M1

[0098]

[0099] N-phenylcarbazole-4-boric acid (200 mmol), 2,3-dichloronitrobenzene (200 mmol), potassium carbonate (240 mmol), tetrakis(triphenylphosphine)palladium (2 mmol), water (100 mL), and 500 mL of dioxane were added to a reaction bottle, heated to 120°C and reacted for 6 h. The reaction was completed under the control of TLC, and water and dichloromethane were added for extraction. The organic phase was separated and concentrated to obtain the intermediate M1-A.

[0100] M1-A (150 mmol), triphenylphosphine (500 mmol) and o-dichlorobenzene (500 mL) were added to a reaction flask and heated to reflux for 5 h. After the reaction was completed, the reaction solution was directly concentrated and purified by column chromatography to obtain M1-B.

[0101] M1-B (100 mmol), 2-aminophenylboronic acid pinacol ester (110 mmol), potassium carbonate (150 mmol), tris(dibenzylideneacetone)dipalladium (1 mmol), 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (2 mmol, S-Phos), water (80 mL), and 300 mL of dioxane were added to a reaction bottle, heated to 120 ° C for 10 h, and the reaction was completed under the control of TLC. After cooling, water and dichloromethane were added for extraction. The organic phase was concentrated and purified by column chromatography to obtain M1-C.

[0102] M1-C (50 mmol), acetic acid 200 mL, sulfuric acid (100 mmol) were added to the reaction bottle, cooled to 15 ° C for reaction, tert-butyl nitrite (100 mmol) was added dropwise, and the temperature was not higher than 15 ° C during the addition. After the addition was completed, the reaction was carried out at room temperature for 2 h. The reaction was completed under the monitoring of TLC. After cooling, water and dichloromethane were added for extraction. The organic phase was concentrated and purified by column chromatography to obtain M1.

[0103] Synthesis of intermediate M2

[0104] The synthesis of M2 is the same as that of M1, except that N-phenylcarbazole-4-boric acid is replaced with an equal amount of dibenzothiophene-1-boric acid.

[0105]

[0106] Synthesis of intermediate M3

[0107] The synthesis of M3 is the same as that of M1, except that N-phenylcarbazole-4-boronic acid is replaced with an equal amount of dibenzofuran-1-boronic acid.

[0108]

[0109] Synthesis of intermediate M4

[0110] The synthesis of M4 is the same as that of M1, except that N-phenylcarbazole-4-boronic acid is replaced with an equal amount of 6-phenyl-dibenzofuran-1-boronic acid.

[0111]

[0112] Synthesis of intermediate M5

[0113] The synthesis of M5 was similar to that of M1, except that N-phenylcarbazole-4-boronic acid was replaced with an equal amount of naphtho[1,2-b]benzofuran-6-boronic acid.

[0114]

[0115] Synthesis of intermediate M6

[0116] The synthesis of M6 was the same as that of M1, except that N-phenylcarbazole-4-boronic acid was replaced with an equal amount of N-(pyridin-3-yl)carbazole-4-boronic acid.

[0117]

[0118] Synthesis of intermediate M7

[0119] The synthesis of M7 is the same as that of M1, except that 2-aminophenylboronic acid pinacol ester is replaced with an equal amount of 3-aminopyridine-2-boronic acid pinacol ester.

[0120]

[0121] Synthesis example 1:

[0122] Synthesis of compound P1

[0123]

[0124] M1 (20 mmol), 2-chloro-4-phenylquinazoline (22 mmol), potassium carbonate (25 mmol), and 200 mL of N,N-dimethylformamide were added to a reaction bottle, heated to 150°C for 4 h, and the reaction was completed under the control of TLC. After cooling, the reaction mixture was poured into water and filtered, and the filter cake was purified by column chromatography to obtain P1.

[0125] Synthesis example 2:

[0126] Synthesis of compound P17

[0127] The difference from Synthesis Example 1 is that 2-chloro-4-phenylquinazoline is replaced with an equal amount of 2-(2-fluorophenyl)-4,6-diphenyl-1,3,5-triazine to obtain Compound P17.

[0128] Synthesis example 3:

[0129] Synthesis of compound P24

[0130] The difference from Synthesis Example 1 is that 2-chloro-4-phenylquinazoline is replaced with an equal amount of 2-chloro-3-(naphthalen-1-yl)quinoxaline to obtain Compound P24.

[0131] Synthesis example 4:

[0132] Synthesis of compound P31

[0133] The difference from Synthesis Example 1 is that 2-chloro-4-phenylquinazoline is replaced with an equal amount of 2'-fluoro-[1,1'-biphenyl]-4-hexanecarbonitrile to obtain Compound P31.

[0134] Synthesis example 5:

[0135] Synthesis of compound P36

[0136]

[0137] M1 (20 mmol), 4-bromobiphenyl (22 mmol), sodium tert-butoxide (25 mmol), tri(dibenzylideneacetone)dipalladium (0.2 mmol), S-Phos (0.4 mmol) and 150 mL of xylene were added to a reaction bottle, heated to 140 °C for 5 h, and the reaction was complete under the monitoring of TLC. After cooling, water and dichloromethane were added for extraction. The organic phase was concentrated and purified by column chromatography to obtain P36.

[0138] Synthesis example 6:

[0139] Synthesis of compound P41

[0140] The difference from Synthesis Example 5 is that 4-bromobiphenyl is replaced with an equal amount of 4-methylbromobenzene to obtain Compound P41.

[0141] Synthesis example 7:

[0142] Synthesis of compound P70

[0143]

[0144] M3 (20 mmol), 2-(3-fluorophenyl)-4-phenylquinazoline (22 mmol), cesium carbonate (25 mmol) and 200 mL of N,N-dimethylformamide were added to a reaction bottle, heated to 150°C for 8 h, and the reaction was completed under the control of TLC. After cooling, the reaction mixture was poured into water and filtered, and recrystallized from xylene to obtain P70.

[0145] Synthesis example 8:

[0146] Synthesis of compound P92

[0147]

[0148] M2 (20 mmol), S1 (22 mmol), sodium tert-butoxide (25 mmol), tri(dibenzylideneacetone)dipalladium (0.2 mmol), S-Phos (0.4 mmol) and 150 mL of xylene were added to a reaction bottle, heated to 140°C for 7 h, and the reaction was complete under TLC monitoring. After cooling, water and dichloromethane were added for extraction. The organic phase was concentrated and purified by column chromatography to obtain P92.

[0149] Synthesis example 9:

[0150] Synthesis of compound P105

[0151]

[0152] M3 (20 mmol), 3-bromobiphenyl (22 mmol), sodium tert-butoxide (25 mmol), tri(dibenzylideneacetone)dipalladium (0.2 mmol), S-Phos (0.4 mmol) and 150 mL of xylene were added to a reaction bottle, heated to 140°C for 8 h, and the reaction was complete under the monitoring of TLC. After cooling, water and dichloromethane were added for extraction. The organic phase was concentrated and purified by column chromatography to obtain P105.

[0153] Synthesis example 10:

[0154] Synthesis of compound P110

[0155] The difference from Synthesis Example 8 is that M2 is replaced with an equal amount of M3 to obtain Compound P110.

[0156] Synthesis example 11:

[0157] Synthesis of compound P121

[0158] The difference from Synthesis Example 5 is that 4-bromobiphenyl is replaced with an equal amount of N-(4-bromophenyl-)-N-phenyl-benzidine to obtain Compound P121.

[0159] Synthesis example 12:

[0160] Synthesis of compound P122

[0161] The difference from Synthesis Example 1 is that M1 is replaced with an equal amount of M6 to obtain compound P122. Synthesis Example 13:

[0162] Synthesis of compound P114

[0163] The difference from Synthesis Example 5 is that 4-bromobiphenyl is replaced by an equal amount of 3-bromobiphenyl, and M1 is replaced by an equal amount of M5, to obtain Compound P114.

[0164] Synthesis example 14:

[0165] Synthesis of compound P48

[0166] The difference from Synthesis Example 5 is that M1 is replaced with an equal amount of M7 to obtain Compound P48.

[0167] The present invention exemplifies the specific synthesis methods of the above compounds. For the compounds for which the specific synthesis methods are not given in the following embodiments, they are also prepared by similar methods, and only the raw materials need to be replaced, which will not be described here. Alternatively, those skilled in the art can also prepare them by other methods in the prior art.

[0168] In order to verify the certainty of the molecular structure of the compound of formula I used in the examples of the present invention, we confirmed it through elemental analysis and mass spectrometry information. The results are shown in Table 1.

[0169] Table 1

[0170] Compound Elemental analysis (%) Mass spectrum (M / Z) P1 C,86.55; H,4.28; N,9.16 611.22 P17 C,85.80; H,4.37; N,9.83 714.26 P24 C, 87.26; H, 4.28; N, 8.46 661.23 P31 C, 88.46; H, 4.33; N, 7.21 584.20 P36 C,90.31; H,4.68; N,5.00 559.21 P41 C,89.50; H,4.86; N,5.64 497.19 P70 C,86.42; H,4.12; N,6.86 612.20 P92 C,86.47;H,4.53;N,4.21;S,4.79 667.21 P105 C, 89.41; H, 4.37; N, 2.92; 484.16 P110 C,88.60; H,4.65; N,4.29 651.24 P121 C, 89.24; H, 4.72; N, 3.83; 727.27 P122 C,84.42; H,4.12; N,11.46 612.21 P114 C,90.03; H,4.34; N,2.62 534.18 P48 C,87.99; H,4.50; N,7.51 560.20

[0171] Examples 1-9, Comparative Example 1

[0172] The above embodiment and comparative example respectively provide an organic electroluminescent device, and the specific preparation method is as follows:

[0173] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone:ethanol, baked in a clean environment to completely remove the water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0174] Place the glass substrate with ITO anode in a vacuum chamber and evacuate to <1×10 -5Pa, vacuum thermally evaporate 10nm of HT-4:HI-3 (97 / 3, w / w) mixture as hole injection layer, 60nm of compound HT-4 as hole transport layer, 60nm of compound HT-47 as electron blocking layer, 40nm of first host: second host: RPD-8 (50:50:3, w / w / w) ternary mixture as light-emitting layer, 5nm of compound ET-17 as hole blocking layer, 25nm of compound ET-46:ET-57 (50 / 50, w / w) mixture as electron transport layer, 1nm of LiF as electron injection layer, 150nm of metal aluminum as cathode. The first host in the light-emitting layer is the compounds listed in Table 2, and the second host is C2; the two hosts are evaporated in a dual-source co-evaporation mode. The total evaporation rate of all organic layers and LiF is controlled at 0.1nm / sec, and the evaporation rate of the metal electrode is controlled at 1nm / sec.

[0175]

[0176] The above compound C1 is detailed in patent application CN109305974A, and C2 is detailed in patent application CN110337432A.

[0177] Performance Test:

[0178] (1) Under the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in the examples and comparative examples were measured. Specifically, the voltage was increased at a rate of 0.1 V per second, and the driving voltage and current efficiency of the organic electroluminescent devices were measured when the brightness reached 3000 cd / m 2 The voltage at this time is the driving voltage, and the current density at this time is measured at the same time; the ratio of brightness to current density is the current efficiency; the current efficiency of comparative example 1 is recorded as 1, and the rest are ratios to the current efficiency of comparative example 1.

[0179] The performance test results are shown in Table 2.

[0180] Table 2

[0181]

[0182] It can be seen from Table 2 that the compound provided by the present invention, as the first light-emitting host material of the dual-host device, can improve the efficiency of the device and reduce the driving voltage.

[0183] Although the main material C1 used in Comparative Example 1 also has an octane 8-membered ring structure, the benzene rings fused to the octane 8-membered ring are connected by heteroatoms N, S or O. This structure forms a large conjugation, resulting in a very low triplet energy level, which cannot meet the requirements of the red light main body, causing energy back transfer and a significant decrease in performance, which is not conducive to improving the efficiency of the device and reducing the driving voltage. The present invention overcomes the problems of C1 by selecting a specific mother core structure shown in Formula I and replacing L1-Ar2 on N, thereby achieving improved device performance.

[0184] Examples 10-15, Comparative Example 2

[0185] The device manufacturing method of Examples 10-15 and Comparative Example 2 is the same as that of Example 1, except that the light-emitting layer is replaced with the main material of the light-emitting layer in Table 3 with a thickness of 40 nm: RPD-8 (100:3, w / w). The structure of the main material C3 used in Comparative Example 2 is as follows:

[0186]

[0187] The performance test method is the same as above, and the results are shown in Table 3, wherein the current efficiency of Comparative Example 2 is recorded as 1, and the others are ratios to the current efficiency of Comparative Example 1.

[0188] Table 3

[0189]

[0190] It can be seen from Table 3 that when the compound provided by the present invention is used as the main material of the light-emitting layer of an organic electroluminescent device, it can effectively improve the device efficiency and reduce the driving voltage.

[0191] By comparing Example 11 and Example 15, it can be seen that the structure in which one of Ar1 and Ar2 is an electron-withdrawing heteroaryl group and the other is an aromatic group (Example 11) can further improve the device performance compared to the structure in which both Ar1 and Ar2 are electron-withdrawing heteroaryl groups (Example 15).

[0192] The applicant declares that the present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A compound, characterized in that The compound has any one of the following structures:

2. A use of the compound according to claim 1, characterized in that: The compound is applied to organic electroluminescent devices.

3. The use according to claim 2, characterized in that: The compound is used as a host material of the organic electroluminescent device.

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

5. The organic electroluminescent device according to claim 4, characterized in that: The organic layer includes a light-emitting layer, and the light-emitting layer contains at least one compound according to claim 1.

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