Organic electroluminescent materials and devices

Abstract

Provided is a compound represented by general formula (I), wherein the meaning of each group is as defined in the specification. Also provided is the use of the compound as a light-emitting layer material in an organic electroluminescent device, and an organic electroluminescent device comprising the compound. #imgabs0#

Description

Technical Field

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

[0002] In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them very suitable for manufacturing on flexible substrates. Beautiful and cool optoelectronic products can be designed and produced according to demand, gaining unparalleled advantages over inorganic materials. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, organic sensors, etc. Among them, OLED has developed particularly rapidly and has achieved commercial success in the field of information display. OLED can provide highly saturated red, green, and blue colors. Full-color display devices made of OLEDs do not require additional backlight sources and have the advantages of brilliant colors, lightness, thinness, and softness.

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

[0004] People have developed a variety of organic materials, combined with various unique device structures, which can improve carrier mobility, regulate carrier balance, break through electroluminescence efficiency, and delay device attenuation. For quantum mechanical reasons, common fluorescent luminescent bodies mainly use singlet excitons generated when electrons and holes combine to emit light, and are still widely used in various OLED products. Some metal complexes, such as iridium complexes, can simultaneously use triplet excitons and singlet excitons to emit light, and are called phosphorescent luminescent bodies. Their energy conversion efficiency can be increased by up to four times that of traditional fluorescent luminescent bodies. Thermally excited delayed fluorescence (TADF) technology promotes the transformation of triplet excitons to singlet excitons. Without the use of metal complexes, triplet excitons can still be effectively utilized to achieve higher luminescence efficiency. Thermally excited sensitized fluorescence (TASF) technology uses materials with TADF properties to sensitize luminescent bodies through energy transfer, which can also achieve higher luminescence efficiency.

[0005] As OLED products gradually enter the market, people have higher and higher requirements for the performance of such products. The currently used OLED materials and device structures cannot completely solve the problems of OLED product efficiency, life span, cost, etc. Through careful thinking and continuous experiments, the researchers of the present invention have discovered an ingenious molecular design scheme, which is described in detail below. Surprisingly, the compounds disclosed in the present invention are very suitable for application in OLED and improve the performance of the device. Summary of the invention

[0006] In view of the defects of the prior art solutions, the present invention provides a new class of compounds for organic electroluminescent devices by integrating molecular structural stability and balanced carrier transport to meet the ever-increasing demand for optoelectronic performance and service life of OLED devices. The compounds of the present invention improve structural stability by selecting the fusion position of the aromatic group, thereby improving performance, and avoid carrier imbalance due to higher hole transport by appropriately selecting heterocyclic groups, thereby improving optoelectronic performance.

[0007] Specifically, in one aspect, the present invention provides a compound of general formula (I):

[0008]

[0009] in:

[0010] A is fused to the mother nucleus at a or b, and B is fused to the mother nucleus at c, d or e;

[0011] m is 0 or 1, n is an integer selected from 0 to 2, and 1≤m+n≤2;

[0012] A and B are independently

[0013]

[0014] C is selected from C5~C 10 Aromatic ring or C4-C 10 A heteroaromatic ring, wherein the aromatic ring or heteroaromatic ring is fused to a connected benzene ring;

[0015] p is an integer selected from 0 to 2;

[0016] R 1 -R 3 represents a monosubstituted to maximum permissible substituent, independently selected from hydrogen, C1 to C 12 Alkyl, C3~C 12 Cycloalkyl, C1~C 12 Alkoxy, halogen, cyano, nitro, hydroxyl, C1~C 12 Silane, amino, substituted or unsubstituted C6~C 30 Arylamino, substituted or unsubstituted C3~C30 Heteroarylamino, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl; when there are multiple R 1 , R 2 or R 3 When they are the same or different, they are independently selected from the group;

[0017] X is selected from NL-Ar, S or O;

[0018] When X is S or O, R 1 -R 3 At least one substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 One of the heteroaryl groups;

[0019] Preferred R 1 -R 3 At least one of them is C3~C 30 Electron-deficient groups;

[0020] When X is NL-Ar,

[0021] L is selected from a single bond, a substituted or unsubstituted C6-C 30 arylene, substituted or unsubstituted C3~C 30 heteroarylene;

[0022] Ar is selected from substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 heteroaryl;

[0023] Preferred R 1 -R 3 and Ar, at least one of which is C3~C 30 Electron-deficient groups;

[0024] The substituent of the substituted group is selected from any one or a combination of at least two of the following groups: halogen, cyano, nitro, hydroxyl, C1-C 12 Alkyl, C3~C 12 Cycloalkyl, C2~C 12 Alkenyl, C1~C 12 Alkoxy or thioalkoxy, C1~C 12 Silane, amino, C6~C 30 Arylamino, C3~C 30 Heteroarylamino, C6~C 30 Aryl, C3~C 30 heteroaryl;

[0025] For example, the substituents are selected from: halogen, cyano, nitro, hydroxyl, unsubstituted or replaced by C6-C 30 Aryl or C3~C 30 Heteroaryl-substituted C1~C 12 Alkyl, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C3~C 12 Cycloalkyl, unsubstituted or substituted with C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C2~C 12 Alkenyl, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C1~C 12 Alkoxy or thioalkoxy, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C1~C 12 Silane, amino, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C6~C 30 Arylamino, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C3~C 30 Heteroarylamino, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C6~C 30 Aryl, unsubstituted or substituted with C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C3~C 30 Heteroaryl.

[0026] More specifically, the compounds of the present invention are represented by general formulas Ia to Ic:

[0027]

[0028] Furthermore, the compound of the present invention is represented by the following general formula:

[0029]

[0030] In some embodiments, C is C5 to C 10 an aromatic ring fused to an attached benzene ring;

[0031] p is 1.

[0032] In some embodiments, C3 to C 30 The electron-deficient group is selected from:

[0033] 1) Substituted or unsubstituted C3~C 30 The electron-deficient heteroaromatic group, when substituted, is selected from any one or a combination of at least two of the following groups: halogen, cyano, nitro, hydroxyl, C1-C 12 Alkyl, C3~C 12 Cycloalkyl, C2~C 12 Alkenyl, C1~C 12 Alkoxy or thioalkoxy, C1~C 12 Silane, amino, C6~C 30 Arylamino, C3~C 30 Heteroarylamino, C6~C 30 Aryl, C3~C 30 heteroaryl;

[0034] For example, the substituent is selected from: unsubstituted or substituted with C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C1~C 12 Alkyl, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C1~C 12 Alkoxy, halogen, cyano, nitro, hydroxyl, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C1~C 12 Silane, amino, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C6~C 30 Arylamino, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C3~C 30 Heteroarylamino, unsubstituted or replaced by C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C6~C 30 Aryl, unsubstituted or substituted with C6~C 30 Aryl or C3~C 30 Heteroaryl-substituted C3~C 30 heteroaryl;

[0035] 2) One of the following formulas (5-1) to (5-4):

[0036]

[0037] Among them, Z 1 -Z 33 Selected from CR 4 or N, R 4A group independently selected from the following: hydrogen, C1-C 12 Alkyl, C3~C 12 Cycloalkyl, C1~C 12 Alkoxy, halogen, cyano, nitro, hydroxyl, C1~C 12 Silane, amino, substituted or unsubstituted C6~C 30 Arylamino, substituted or unsubstituted C3~C 30 Heteroarylamino, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl; R 4 When the number of R is more than 2, multiple R 4 Same or different from each other, or adjacent R 4 Condensed with the connected benzene ring to form a substituted or unsubstituted C9~C 30 aryl or heteroaryl,

[0038] In formula (5-1), Z 1 -Z 5 At least one of them is N;

[0039] In formula (5-2), Z 6 -Z 13 At least one of them is N;

[0040] In formula (5-3), Z 14 -Z 23 At least one of them is N;

[0041] In formula (5-4), Z 24 -Z 33 At least one of them is N;

[0042] The above * indicates a connection site.

[0043] "Electron-deficient substituent" in this specification refers to a group that reduces the electron cloud density on the benzene ring 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, which is a measure of an electron-withdrawing group (positive Hammett value) or an electron-donating group (negative Hammett value). The Hammett equation is described in more detail in Thomas H.Lowry and Katheleen Schueller Richardson, "Mechanism and Theory In Organic Chemistry", New York, 1987, 143-151 pages, which are cited herein as reference. Such groups can be listed but are not limited to: triazine, pyrimidine, benzopyrimidine, benzopyridinyl, naphthyridine, phenanthroline, pyrazinyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, pyridazinyl, and the above-mentioned groups substituted by alkyl or aryl. In addition, when each group in the present specification has a substituent, the carbon number of the group does not include the carbon number of the substituent; aryl, arylene, heteroaryl, heteroarylene, etc. include not only monocyclic but also condensed rings.

[0044] In some embodiments, C3-C 30 The electron-deficient group is selected from formula (5-1) or (5-2).

[0045] In some embodiments, C3-C 30 The electron-deficient group is selected from substituted or unsubstituted pyridine, pyrimidine, triazine, quinoline, quinazoline, quinoxaline.

[0046] The substituents in the above-mentioned substituted pyridine, pyrimidine, triazine, quinoline, quinazoline and quinoxaline are selected from the following groups:

[0047] Phenyl, naphthyl, biphenyl, dibenzofuran, dibenzothiophene, pyridyl, phenanthryl, terphenyl.

[0048] In some embodiments, the compound of formula (I) has a structure as shown in the following formula A to formula O:

[0049]

[0050] In some embodiments, in Formula A to Formula O,

[0051] L is selected from a single bond, C6-C 30 Arylene, C3~C 30 heteroarylene;

[0052] Ar is selected from C6~C 30 Aryl, one or more C3~C 30 Heteroaryl or C6~C 30Aryl substituted C6~C 30 Aryl, C3~C 30 Heteroaryl, one or more C3~C 30 Heteroaryl or C6~C 30 Aryl substituted C3~C 30 heteroaryl;

[0053] R 1 -R 3 Selected from hydrogen, C6~C 30 Aryl, one or more C3~C 30 Heteroaryl or C6~C 30 Aryl substituted C6~C 30 Aryl, C3~C 30 Heteroaryl, one or more C3~C 30 Heteroaryl or C6~C 30 Aryl substituted C3~C 30 Heteroaryl.

[0054] In some embodiments, when X is NL-Ar, R 1 -R 3 For hydrogen.

[0055] In some embodiments, when X is S or O, preferably R 1 -R 3 One of them is C3~C 30 Electron-deficient group, the rest is hydrogen.

[0056] In some embodiments, the compound of formula (I) is as shown in the following formula 4-1 to formula 4-11:

[0057]

[0058] In formula 4-1 to formula 4-11, R 1 -R 3 As defined for formula (I), X' is a group as defined for X in formula (I).

[0059] The substituents in the compound of formula (I) may be as shown in the following table, wherein * represents the connection site, when L is asymmetrically connected, a represents the connection site with N in the parent core, and b represents the connection site with Ar.

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092] In some embodiments, when X is S or O, for example in formula L to O, the substituents are shown in the following table:

[0093]

[0094]

[0095]

[0096]

[0097]

[0098] The above formulas A to O are used as the core structures and are respectively combined with the substituents in the above list to form the compounds of the present invention. The specific compound structures of the present invention are represented by the combination of the core structure formula number and the substituent number. For example, compound A-1 represents a compound having the core structure of formula A and the first group of substituents, and G-80 represents a compound having the core structure of formula G and the 80th group of substituents. Their structures are respectively represented as follows:

[0099]

[0100] According to the above combination rules, the compounds of the present invention are shown in the following table:

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124] In another aspect, the present invention provides use of the compound as described above, wherein the use is as a material for a light-emitting layer in an organic electroluminescent device.

[0125] In another aspect, the present invention provides an organic electroluminescent device, comprising a first electrode, a second electrode and an organic layer between the first electrode and the second electrode, wherein the organic layer comprises any one or a combination of at least two of the compounds of the present invention.

[0126] The organic electroluminescent device provided by the present invention comprises a first electrode, a second electrode, and an organic material layer located between the electrodes. The organic material can be divided into multiple regions. For example, the organic material layer can include a hole transport region, a light emitting layer, and an electron transport region.

[0127] In a specific 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.

[0128] 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), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0129] The organic material layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, etc. The compound used as the organic material layer can be organic small molecules, organic macromolecules and polymers, and combinations thereof.

[0130] 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).

[0131] 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 such as the compounds shown in HT-1 to HT-34 below; or any combination thereof.

[0132]

[0133]

[0134] 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.

[0135]

[0136] The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit light of different wavelength spectra, and may also include a host material (Host). The light-emitting layer may 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 may be arranged in a plane according to a pixel pattern, or may be stacked together to form a color light-emitting layer. When light-emitting layers of different colors are stacked together, they may be separated from each other or may be connected to each other. The light-emitting layer may also be a single color light-emitting layer that can simultaneously emit different colors such as red, green, and blue.

[0137] 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.

[0138] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology, and the main material of the light-emitting layer is selected from the materials of the present invention.

[0139] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0140]

[0141]

[0142]

[0143] Here, D stands for deuterium.

[0144] 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.

[0145]

[0146]

[0147] The OLED organic material layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region may also be a multilayer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0148] 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-57 listed below.

[0149]

[0150]

[0151]

[0152] 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.

[0153] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca.

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

[0155] The compound provided by the present invention is used in an organic electroluminescent device to make the organic electroluminescent device have the effects of low starting voltage, high luminous efficiency and long life, and the starting voltage can be ≤4.0V, and the current efficiency and LT95 life are improved. DETAILED DESCRIPTION

[0156] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0157] In this specification, unless otherwise specified, the following terms have the following meanings:

[0158] It should be noted that, 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 generally does not include the number of carbon atoms in the substituent.

[0159] In the present invention, the expression of chemical elements includes the concept of isotopes with the same chemical properties. For example, the expression of "hydrogen" also includes the concept of "deuterium" and "tritium" with the same chemical properties, that is, the hydrogen in the compound can be replaced by "deuterium" or "tritium". It should be noted that in the present invention, "D" can also be used to represent "deuterium". The groups defined for the compounds of the present invention include groups in which one or more hydrogens are replaced by deuterium or tritium, for example, alkyl includes non-deuterated alkyl or alkyl in which one or more hydrogens are replaced by deuterium.

[0160] In the present specification, the alkyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 12. Specific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, and the like.

[0161] In the present specification, the aryl group is not particularly limited, but preferably has 5 to 30 carbon atoms, more preferably has 5 to 14 carbon atoms, and particularly has 5 to 10 carbon atoms, such as 6, 10 or 14 carbon atoms. Specific examples of aryl groups include phenyl, biphenyl, naphthyl, anthracenyl, phenanthrenyl, fluorenyl, etc. In the present specification, heteroaryl groups are heteroaryl groups containing one or more of O, N, S, and Si as heteroatoms, and the number of carbon atoms is preferably 3 to 30, more preferably has 5 to 14 carbon atoms, and particularly has 5 to 10 carbon atoms. Specific examples of heteroaryl groups include pyridyl, thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, etc. The aryl and heteroaryl groups therein include monocyclic and condensed ring groups.

[0162] In this specification, the expression of "—" crossing a ring structure indicates that the connection site is located at any position on the ring structure that can form a bond. For the expression of "—" crossing a ring structure in a fused ring, it means that the connection site can be located at any carbon atom of the fused ring crossed by the "—". For example, R shown in formula (I) 2 and R 3 Represents R 2 and R 3 The radical may be located at any substitutable position on Ring A or Ring B and the benzene ring fused thereto.

[0163] In this specification, the "maximum permissible substituent" refers to the maximum number of substituents that can be taken on the premise that the substituted group meets the bonding requirements. For example, in formula (I), R 1 -R 3 indicates monosubstituted to the maximum permissible substituent, which means R 1 , R 2 and R 3 The maximum number of substitutions allowed is used at the substitutable positions of the ring structure involved. 1, R 2 or R 3 When , they are each independently selected from the groups defined therefor.

[0164] The term "substituted" mentioned in the present specification means that the term may be substituted by one or more substituents.

[0165] The synthetic route of the compound of formula (I) of the present invention is:

[0166]

[0167] By replacing different Different target compounds can be obtained. It should be noted that in the above-mentioned synthesis method, Buchwald-Hartwig coupling is used to connect the substituent Ar to the mother core, but it is not limited to this coupling method. Those skilled in the art can also choose other methods, such as Ullmann coupling method, Grignard reagent method, SUZUKI and other known methods, but are not limited to these methods. Any equivalent synthesis method can be used to achieve the purpose of connecting the substituent Ar to the mother core and can be selected according to needs.

[0168] Synthesis Example

[0169] The compounds whose synthesis methods are not mentioned in the examples are all raw materials obtained through commercial channels. Various chemicals used in the examples, such as petroleum ether, ethyl acetate, N,N-dimethylformamide, dichloromethane, potassium carbonate, sodium tert-butoxide and other basic chemical raw materials, are all commercially available products.

[0170] Synthesis example 1:

[0171] Synthesis of Compound A-1

[0172]

[0173]

[0174] 7H-dibenzocarbazole (100 mmol), o-fluoronitrobenzene (120 mmol), potassium carbonate (150 mmol) and DMF (300 ml) were added to a reaction bottle and heated to reflux for 5 h. The reaction was completed by monitoring by TLC. The reaction solution was poured into water and filtered. The filter cake was washed with ethanol to obtain intermediate a1-1.

[0175] Add a1-1 (50 mmol), triphenylphosphine (100 mmol) and 200 ml of o-dichlorobenzene into a reaction bottle and reflux for 6 h. The reaction is complete when monitored by TLC. After cooling, extract with dichloromethane and concentrate, and then separate by column chromatography to obtain intermediate a1-2.

[0176] A1-2 (30 mmol), 2-chloro-4-phenylquinazoline (30 mmol), sodium tert-butoxide (50 mmol), Pd2(dba)3 (0.3 mmol), S-Phos (0.6 mmol) and 300 ml of xylene were added to a reaction bottle and refluxed for 4 h. The reaction was completed under the monitoring of TLC. After cooling, the organic phase was extracted with dichloromethane and concentrated to obtain A-1.

[0177] Synthesis Example 2: Synthesis of Compounds B-2 and C-2

[0178]

[0179] Sb (100 mmol), o-fluoronitrobenzene (120 mmol), potassium carbonate (150 mmol) and DMF (300 ml) were added to a reaction flask and heated to reflux for 5 h. The reaction was completed under the control of TLC. The reaction solution was poured into water and filtered. The filter cake was washed with ethanol to obtain intermediate b1-1.

[0180] Add b1-1 (50 mmol), triphenylphosphine (100 mmol) and 200 ml of o-dichlorobenzene into a reaction bottle and reflux for 6 h. The reaction is complete when monitored by TLC. After cooling, extract with dichloromethane and concentrate, and then separate by column chromatography to obtain intermediates b1-2 and c1-2.

[0181] Add b1-2 (30 mmol), 2-chloro-4-α-naphthylquinazoline (30 mmol), sodium tert-butoxide (50 mmol), Pd2(dba)3 (0.3 mmol), S-Phos (0.6 mmol) and 300 ml of xylene into a reaction bottle and reflux for 4 h. The reaction is completed under the monitoring of TLC. After cooling, the organic phase is extracted with dichloromethane and concentrated to obtain B-2.

[0182] Similarly, replace b1-2 with an equivalent amount of c1-2 to obtain compound C-2.

[0183] Synthesis example 3:

[0184] Synthesis of compound E-16

[0185]

[0186] The method is the same as that of Synthesis Example 1, except that 7H-dibenzocarbazole is replaced by an equivalent amount of Se, and 2-chloro-4-phenylquinazoline is replaced by an equivalent amount of 2-([1,1'-biphenyl]-3-yl)-3-chloroquinoxaline to obtain compound E-16.

[0187] Synthesis example 4:

[0188] Synthesis of compound G-4

[0189]

[0190] The method is the same as that of Synthesis Example 1, except that 2-chloro-4-phenylquinazoline is replaced with an equivalent amount of 4-([1,1'-biphenyl]-4-yl)-2-chloroquinazoline to obtain compound G-4.

[0191] Synthesis example 5:

[0192] Synthesis of compound G-55

[0193]

[0194] The method is the same as that of Synthesis Example 1, except that 2-chloro-4-phenylquinazoline is replaced with an equivalent amount of S1 to obtain compound G-55.

[0195] Synthesis example 6:

[0196] Synthesis of compound G-132

[0197]

[0198] The method is the same as that of Synthesis Example 1, except that 2-chloro-4-phenylquinazoline is replaced with an equivalent amount of S2 to obtain compound G-132.

[0199] Synthesis example 7:

[0200] Synthesis of compound G-121

[0201]

[0202] The method is the same as that of Synthesis Example 1, except that 2-chloro-4-phenylquinazoline is replaced with an equivalent amount of S3 to obtain compound G-121.

[0203] Synthesis example 8:

[0204] Synthesis of compound L-218

[0205]

[0206] 2-Bromo-6-fluoronitrobenzene (100 mmol), 1-naphthaleneboric acid (100 mmol), potassium carbonate (120 mmol), tetrakis(triphenylphosphine)palladium 1 g, dioxane 300 ml, and water 50 ml were added to a reaction flask, and refluxed for 4 h under nitrogen protection. The reaction was completed after TLC monitoring, and intermediate A was extracted with water and dichloromethane.

[0207] A (70 mmol), triphenylphosphine (140 mmol) and 200 ml of o-dichlorobenzene were added to a reaction bottle and refluxed for 6 h. After the reaction was complete, the temperature was lowered and water and dichlorobenzene were added for extraction. The organic phase was concentrated and purified by column chromatography to obtain intermediate B.

[0208] B (50 mmol), 3-bromo-6-iodophenol (50 mmol), cuprous iodide (25 mmol), o-phenanthroline (50 mmol), potassium phosphate (70 mmol), and 200 ml of xylene were added to a reaction flask, and the mixture was refluxed for 10 h. After cooling, water and dichloromethane were added for extraction. The organic phase was concentrated and purified by column chromatography to obtain intermediate C.

[0209] C (30 mmol) was added to 200 ml DMF and cooled to 0°C. 50 (mmol) of sodium hydrogen sulfide was added, and the mixture was reacted for 30 min and then heated to 60°C for 5 h. The reaction was complete under the control of TLC. The reaction mixture was poured into water and filtered. The filter cake was washed with ethanol to obtain intermediate D.

[0210] D (20 mmol), bipyralidone (30 mmol), potassium acetate (30 mmol), Pd (dppf) Cl2 (0.5 g), and dioxane were added to a reaction flask, refluxed for 4 h, cooled, and then water and dichloromethane were added for extraction. The organic phase was concentrated, washed with ethanol, and dried to obtain intermediate E. E (15 mmol), 2-chloro-4-(1-naphthyl)quinazoline (15 mmol), potassium carbonate (20 mmol), tetrakis (triphenylphosphine) palladium 0.5 g, dioxane 150 ml, and water 20 ml were added to a reaction flask, refluxed for 4 h under nitrogen protection, and the reaction was completed after TLC monitoring. After cooling, it was directly filtered and the filter cake was purified by column chromatography to obtain the product L-218.

[0211] In order to verify the certainty of the above molecular structure, it was confirmed by elemental analysis (measuring instrument: Thermo Fisher FLASH2000CHNS / O organic element analyzer) and mass spectrometry information (measuring instrument: ZAB-HS mass spectrometer, manufactured by Micromass, UK), as shown in Table 1.

[0212] Table 1. Characterization results of synthetic compounds

[0213] Compound Elemental analysis (%) Mass spectrometry A-1 C,85.68; H,4.31; N,10.00 560.2 B-2 C,85.68; H,4.31; N,10.00 560.2 C-2 C,86.54; H,4.29; N,9.16 610.2 E-16 C,86.79; H,4.42; N,8.79 636.2 G-4 C,85.99; H,4.48; N,9.53 586.2 G-55 C, 85.97; H, 4.47; N, 9.56 586.2 G-132 C,84.12; H,4.44; N,11.43 613.2 G-121 C,85.99; H,4.48; N,9.53 586.2 L-218 C,85.56; H,4.13; N,7.46 561.1

[0214] Device Embodiment

[0215] The preparation process of the organic electroluminescent device in this embodiment is as follows:

[0216] Device Example 1

[0217] 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 until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam. The glass substrate with the anode was placed in a vacuum chamber and evacuated to <1×10-5 Pa, on the above anode layer film, 10nm of HT-4:HI-3 (97 / 3, w / w) mixture was vacuum-evaporated in sequence as a hole injection layer, 60nm of compound HT-4 as a hole transport layer, 40nm of compound A-1:RPD-8 (100:3, w / w) binary mixture as a light-emitting layer, 25nm of compound ET-46:ET-57 (50 / 50, w / w) mixture as an electron transport layer, 1nm of LiF as an electron injection layer, and 150nm of metal aluminum as a cathode. The total evaporation rate of all organic layers and LiF was controlled at 0.1nm / sec, and the evaporation rate of the metal electrode was controlled at 1nm / sec.

[0218] Device Example 2

[0219] Device Example 2 is manufactured in the same manner as Device Example 1, except that A-1 in the light-emitting layer is replaced by B-2.

[0220] Device Example 3

[0221] Device Example 3 is manufactured in the same manner as Device Example 1, except that A-1 in the light-emitting layer is replaced by C-2.

[0222] Device Example 4

[0223] Device Example 4 is manufactured in the same manner as Device Example 1, except that A-1 in the light-emitting layer is replaced by E-16.

[0224] Device Example 5

[0225] Device Example 5 is manufactured in the same manner as Device Example 1, except that A-1 in the light-emitting layer is replaced by G-4.

[0226] Device Example 6

[0227] Device Example 6 is manufactured in the same manner as Device Example 1, except that A-1 in the light-emitting layer is replaced by G-55.

[0228] Device Example 7

[0229] Device Example 7 is manufactured in the same manner as Device Example 1, except that A-1 in the light-emitting layer is replaced by G-132.

[0230] Device Example 8

[0231] Device Example 8 is manufactured in the same manner as Device Example 1, except that A-1 in the light-emitting layer is replaced by L-218.

[0232] The structures of the compounds used in the comparative examples of the present invention are as follows:

[0233]

[0234] Comparative Example 1

[0235] Comparative Example 1 was prepared in the same manner as Device Example 1, except that A-1 in the light-emitting layer was replaced by compound R-1.

[0236] Comparative Example 2

[0237] Comparative Example 2 was prepared in the same manner as in Device Example 1, except that A-1 in the light-emitting layer was replaced by compound R-2.

[0238] Comparative Example 3

[0239] Comparative Example 3 was prepared in the same manner as in Device Example 1, except that A-1 in the light-emitting layer was replaced by compound R-3.

[0240] Device testing method:

[0241] The organic electroluminescent device prepared by the above process was subjected to the following performance tests:

[0242] At the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in Examples 1 to 8 and Comparative Examples 1 to 3 and the life of the devices were measured using a digital source meter and a brightness meter. Specifically, the voltage was increased at a rate of 0.1 V per second, and the current density of the organic electroluminescent device was measured when it reached 10 mA / cm 2 The voltage at this time is the driving voltage, and the brightness at this time is measured at the same time; the ratio of brightness to current density is the current efficiency;

[0243] The life test of LT95 is as follows: Use a luminance meter at 10000cd / m 2 At the same brightness, the current is kept constant and the brightness of the organic electroluminescent device is measured to drop to 9500cd / m 2 The time in hours.

[0244] The current efficiency and life data in the following table are relative values, that is, relative to the values ​​of Comparative Example 1, and the current efficiency and life data of Comparative Example 1 are both recorded as 1.

[0245] The performance of organic electroluminescent devices is shown in Table 2:

[0246] Table 2. Performance of organic electroluminescent devices of Examples and Comparative Examples

[0247] Compound No. Voltage V Current efficiency T95(10000nit) Comparative Example 1 4.7 1 1 Comparative Example 2 4.6 1.09 1.05 Comparative Example 3 4.2 1.32 1.225 Device Example 1 3.8 1.65 1.525 Device Example 2 3.8 1.64 1.5 Device Example 3 3.7 1.73 1.45 Device Example 4 3.9 1.57 1.4 Device Example 5 3.7 1.68 1.55 Device Example 6 3.6 1.71 1.6 Device Example 7 3.8 1.60 1.475 Device Example 8 3.9 1.64 1.5

[0248] The above results show that the novel organic material of the present invention can be used in organic electroluminescent devices to effectively reduce the starting and ending voltages and improve the current efficiency, and is a red light main body material with good performance.

[0249] Compared with Comparative Example 1, due to the presence of a 7-membered ring, the conjugation becomes stronger, resulting in a low triplet energy level, and the energy transfer between the guest becomes worse, resulting in its voltage and efficiency being inferior to the material of the present invention;

[0250] The common characteristics of the compounds in Examples 2 and 3 are that the hole-type energy is enhanced but the electron absorption is weak, and the balance of carriers cannot be achieved. In summary, the present invention adjusts the conjugated structure on the carbazole ring so that its three-line energy level meets the requirements of the red light host material. The general formula takes into account the balanced transmission of carriers and is a red light host material with good performance.

[0251] Although the present invention has been described in conjunction with the embodiments, the present invention is not limited to the above embodiments. It should be understood that under the guidance of the concept of the present invention, those skilled in the art may make various modifications and improvements. The appended claims summarize the scope of the present invention.

Claims

1. A compound represented by general formula (I): in: A is fused to the mother nucleus at a or b, and B is fused to the mother nucleus at c, d or e; m is 0 or 1, n is an integer selected from 0 to 2 and is not 2, and 1≤m+n≤2; A and B are independently C is selected from a benzene ring; p is 0; X is selected from NL-Ar, S or O; When X is S or O, R 1 C3~C 30 Electron-deficient group, R 2 and R 3 is hydrogen; When X is NL-Ar, R 1 -R 3 is hydrogen; L is selected from a single bond or a phenylene group; Ar is C3~C 30 Electron-deficient groups; C3~C 30 The electron-deficient group is selected from substituted or unsubstituted pyridine, pyrimidine, triazine, quinoline, quinazoline, quinoxaline, When C3~C 30 When the electron-deficient group is substituted, the substituent is selected from the following groups: Phenyl, naphthyl, biphenyl.

2. The compound according to claim 1, having a structure selected from the following general formula:

3. The compound according to claim 1, having a structure as shown in the following formula A to formula O as a parent core:

4. The compound according to claim 3, wherein the substituents are as shown in the following table, wherein * represents the connection site, when L is asymmetrically connected, a represents the connection site with N in the parent core, and b represents the connection site with Ar, When X is NL-Ar, the substituent is: When X is O, the substituent is:

5. The compound according to claim 4, selected from the compounds having the parent core and substituent numbering as described in the following table, wherein the parent core represents the structure shown in formula A to formula L in claim 3, and the substituent numbering is as described in claim 4: 。 6 . Use of the compound according to claim 1 as a material for a light-emitting layer in an organic electroluminescent device.

7. An organic electroluminescent device, comprising a first electrode, a second electrode and an organic layer located between the first electrode and the second electrode, wherein the organic layer comprises any one or a combination of at least two of the compounds according to any one of claims 1 to 5.

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