CN113444093A

CN113444093A - Compound and application thereof

Info

Publication number: CN113444093A
Application number: CN202010231011.6A
Authority: CN
Inventors: 李之洋; 张辉; 曾礼昌
Original assignee: Beijing Eternal Material Technology Co Ltd
Current assignee: Beijing Eternal Material Technology Co Ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2021-09-28
Anticipated expiration: 2040-03-27
Also published as: CN113444093B

Abstract

The invention relates to a compound and application thereof, wherein the compound has a structure shown in a formula I, and the compound provided by the invention takes a carbazole derivative as a mother-core structure, wherein a substituent group must contain substitution of a 7-membered aromatic ring, so that the design aims at ensuring a corresponding HOMO energy level by carbazole, providing good hole transmission capability, adding the 7-membered aromatic ring, providing a larger plane conjugated group and increasing the carrier mobility of the whole molecule, and moreover, due to the introduction of the rigid structure, the material has high glass transition temperature and excellent thermal stability, and can effectively improve the device efficiency, reduce the driving voltage and prolong the service life when being applied to an OLED device.

Description

Compound and application thereof

Technical Field

The invention relates to the technical field of organic electroluminescence, in particular to a compound and application thereof.

Background

In recent years, Organic Light Emitting Diodes (OLEDs) have been developed very rapidly, and have a place in the field of information display, which is mainly benefited from the fact that OLED devices can prepare full-color display devices using three primary colors of high saturation, red, green and blue, and can realize bright, light, thin and soft colors without additional backlight sources.

The Organic Light Emitting Diode (OLED) device plays an important role in a thin-layer structure containing various organic functional materials, and common organic functional materials comprise a light emitting layer material, an electron blocking layer material, an electron transport layer material, a hole blocking layer material, a hole transport layer material and the like. After the power is switched on, electrons and holes are respectively injected and transmitted to the light-emitting layer and are recombined to generate excitons, so that light is emitted. Therefore, the research on organic functional materials in OLED devices is a key research topic for those skilled in the art.

At present, researchers have developed various organic functional materials for various specific device structures, which play roles in improving carrier mobility, regulating carrier balance, breaking through electroluminescence efficiency, and delaying device attenuation.

Conventional fluorescent emitters emit light primarily using singlet excitons generated upon recombination of holes and electrons, and such emitters are still used in various OLED devices. In addition, a phosphorescent emitter, that is, a material which can emit light by using both triplet excitons and singlet excitons, such as an iridium complex or the like, is also included. The thermal excitation delayed fluorescence (TADF) technology can still effectively utilize triplet excitons to achieve higher luminous efficiency without using a metal complex by promoting the conversion of triplet excitons to singlet excitons. The thermal excitation sensitization fluorescence (TASF) technology is to adopt TADF material to sensitize the luminophor in an energy transfer mode, so that higher luminous efficiency is realized, and the TADF material has wide application prospect in the OLED field.

Although various organic functional layer materials have been developed, nowadays, the requirements of people on the performance of the OLED device are higher and higher, and the existing organic functional materials cannot be applied to new OLED devices with higher performance.

Therefore, there is a need in the art to develop a wider variety of organic functional materials, which can improve the light emitting efficiency, reduce the driving voltage, and prolong the service life when applied to OLED devices.

Disclosure of Invention

An object of the present invention is to provide a compound which can improve luminous efficiency, reduce driving voltage, and prolong a service life when applied to an OLED device.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a compound, which has a structure shown in a formula I;

in the formula I, A has a structure shown in a formula II;

in the formula II, X₁～X₁₄Independently selected from CR₁Or N, said R₁Independently selected from 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, amino, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroaryl amino and substituted or unsubstituted C3-C30 heteroaryl, wherein R is selected from the group consisting of C, B, C, B, C, B6, B₁Independently with the attached aromatic ring to form a ring or not; preferably not linked to a ring; when two or more R's are present in formula II₁When more than two R are present₁May be the same or different;

in formula II, a represents a bond of the group;

in formula I, the ring B and the ring C independently represent a substituted or unsubstituted C6-C30 aromatic ring or a substituted or unsubstituted C3-C30 heteroaromatic ring fused with a five-membered ring;

in the formula I, L is¹One selected from single bond, substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C3-C30 heteroarylene;

R₁、L¹ring B and ring CThe substituted groups are independently selected from one or a combination of at least two of halogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 condensed ring heteroaryl. The above "substituted or unsubstituted" group may be substituted with one substituent, or may be substituted with a plurality of substituents, and when a plurality of substituents are present, different substituents may be selected from different substituents.

In the above substituents, the number of carbon atoms of the chain alkyl group having from C1 to C10 may be C2, C3, C4, C5, C6, C7, C8, C9, C10, or the like; the carbon number of the C3-C10 cycloalkyl group can be C4, C5, C6, C7, C8, C9, C10 and the like; the C1-C10 alkoxy group may have C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the C1-C10 thioalkoxy group may have C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the C6-C30 monocyclic aryl group may have C10, C12, C14, C16, C18, C20, C26, C28 and the like; the number of carbons of the C10-C30 condensed ring aryl group may be C10, C12, C14, C16, C18, C20, C26, C28, etc.; the C3-C30 monocyclic heteroaryl group may have C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, etc.; the carbon number of the C6-C30 fused ring heteroaryl can be C10, C12, C14, C16, C18, C20, C26, C28 and the like. More preferably, the substituent is selected from any one of C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 condensed ring heteroaryl, and specifically, phenyl, naphthyl, biphenyl, pyridyl, pyrimidyl, quinolyl, quinoxalyl, quinazolinyl, dibenzofuranyl, dibenzothienyl, and the like are preferable.

The compound provided by the invention takes a 7-membered conjugated aromatic ring as a parent nucleus structure (a structure shown in a formula II), wherein a substituent group necessarily contains carbazole and derivative groups thereof

The carbazole is designed to ensure the corresponding HOMO energy level and provide good hole transport capability. The structure shown in formula II is added, so that a larger plane conjugated group is provided, the carrier mobility of the whole molecule is increased, and moreover, due to the introduction of the rigid structure, the material has high glass transition temperature and excellent thermal stability, and when the material is applied to an OLED device, the device efficiency can be effectively improved, the driving voltage is reduced, and the service life is prolonged.

In the present invention, the heteroatom of heteroaryl is generally referred to as N, O, S.

The atomic names given in this disclosure, including their respective isotopes, for example, hydrogen (H) includes¹H (protium or H),²H (deuterium or D), etc.; carbon (C) then comprises¹²C、¹³C and the like.

In the present invention, the expression of the "-" underlined loop structure indicates that the linking site is located at an arbitrary position on the loop structure where the linkage can be formed.

In the present invention, the carbon number of the C1 to C10 chain alkyl group may be C2, C3, C4, C5, C6, C7, C8, C9, C10, or the like; the carbon number of the C3-C10 cycloalkyl group can be C4, C5, C6, C7, C8, C9, C10 and the like; the C1-C10 alkoxy group may have C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the C1-C10 silyl group may have C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the C6-C30 aryl group may have C10, C12, C14, C16, C18, C20, C26, C28 and the like; the number of carbon atoms of the C6-C30 arylamino group can be C10, C12, C14, C16, C18, C20, C26, C28 and the like; the carbon number of the C3-C30 heteroaryl amino group can be C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28 and the like; the carbon number of the C3-C30 heteroaryl group may be C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, or the like. The number of carbons is merely an example and is not limited to the above.

Preferably, in formula II, X is₁～X₁₄Are all CR₁。

Preferably, said R is₁Is hydrogen.

Preferably, the ring B and the ring C are independently selected from one of a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, and a substituted or unsubstituted group shown in a formula III;

in formula III, ring D represents a substituted or unsubstituted C6-C24 aromatic ring or a substituted or unsubstituted C3-C24 heteroaromatic ring;

in formula III, X and Y are independently selected from single bond, S, O or N-L²-Ar²And X and Y are not simultaneously a single bond;

said L²One selected from single bond, substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C3-C30 heteroarylene;

ar is²Selected from substituted or unsubstituted C3-C30 electron-deficient heteroaryl or substituted or unsubstituted C6-C30 aryl;

in formula III, the dotted line on the benzene ring represents the position fused with the five-membered ring in formula I;

ring D, L²And Ar²The substituted group is one or the combination of at least two of halogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 condensed ring heteroaryl.

Preferably, at least one of the ring B and the ring C is a substituted or unsubstituted group of formula III.

The invention preferably contains at least one condensed group shown in the formula III, the introduction of the structure can provide good hole transport property, and furthermore, an electron-absorbing group can be introduced into the position of X or Y to adjust the electron transport property of the molecule, so that the molecule has bipolarity, the transport of carriers is balanced, and the device performance is further improved.

Preferably, the ring B is a substituted or unsubstituted group represented by formula III, and the ring C is a substituted or unsubstituted benzene ring or a substituted or unsubstituted naphthyl group.

Preferably, in formula III, the ring D represents a substituted or unsubstituted benzene ring.

Preferably, in formula III, at least one of X and Y is N-L²-Ar²。

Preferably, in formula III, X and Y are independently selected from a single bond or N-L²-Ar²。

Preferably, in formula III, X is a single bond and Y is N-L²-Ar²。

Preferably, the compound has the structure shown in formula I-1;

in the formula I-1, the A, L¹Has the same meaning as in formula I, and said D, X, Y has the same meaning as in formula III.

Preferably, the compound has a structure represented by formula (a) to formula (f):

structures of formula (a) and formula (b) are preferred;

a and L¹Having the same meaning as in formula I, said Ar²And L²Have the same meaning as in formula III.

Specifically, the compounds of formula (a) include (a-1), (a-1) and (a-3);

specifically, the compound of formula (b) includes (b-1), (b-1) and (b-3);

specifically, the compounds of formula (c) include (c-1), (c-1) and (c-3);

specifically, the compounds of formula (d) include (d-1), (d-1) and (d-3);

specifically, the compounds of formula (e) include (e-1), (e-1) and (e-3);

specifically, the compounds of formula (f) include (f-1), (f-1) and (f-3);

preferably, Ar is²And (b) any one selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted triazinyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidyl and substituted or unsubstituted quinolyl.

Preferably, Ar is²Selected from substituted or unsubstituted C3-C30 electron-deficient heteroaryl groups, preferably nitrogen-containing substituted or unsubstituted C3-C30 electron-deficient heteroaryl groups.

Preferably, Ar is²Has one of the following structures (3-1) to (3-4):

in the formula (3-1), the Z¹、Z²、Z³、Z⁴And Z⁵Each independently selected from CR³Or an N atom, and Z¹、Z²、Z³、Z⁴And Z⁵At least one of which is an N atom,

in the formula (3-2), the Z⁶、Z⁷、Z⁸、Z⁹、Z¹⁰、Z¹¹、Z¹²And Z¹³Each independently selected from CR³Or an N atom, and Z⁶、Z⁷、Z⁸、Z⁹、Z¹⁰、Z¹¹、Z¹²And Z¹³At least one of which is an N atom,

in the formula (3-3), the Z¹⁴、Z¹⁵、Z¹⁶、Z¹⁷、Z¹⁸、Z¹⁹、Z²⁰、Z²¹、Z²²And Z²³Each independently selected from CR³Or an N atom, and Z¹⁴、Z¹⁵、Z¹⁶、Z¹⁷、Z¹⁸、Z¹⁹、Z²⁰、Z²¹、Z²²And Z²³At least one of which is an N atom,

in the formula (3-4), Z²⁴、Z²⁵、Z²⁶、Z²⁷、Z²⁸、Z²⁹、Z³⁰、Z³¹、Z³²And Z³³Each independently selected from CR³Or an N atom, and Z²⁴、Z²⁵、Z²⁶、Z²⁷、Z²⁸、Z²⁹、Z³⁰、Z³¹、Z³²And Z³³At least one of which is an N atom,

the R is³Selected from hydrogen, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 arylaminoAnd substituted or unsubstituted C3-C30 heteroaryl;

wherein denotes the access bond of the group.

Preferably, Ar is²Has the structure shown in (3-1) or (3-2).

Preferably, Ar is²One selected from the following substituted or unsubstituted groups: pyridyl, quinolyl, quinazolinyl, triazinyl, pyrimidinyl or quinoxalinyl.

Preferably, Ar is²Has the structure shown in (3-1) or (3-2);

in the formula (3-1), Z¹、Z²、Z³、Z⁴And Z⁵At least two of which are N atoms; and/or, in the formula (3-2), Z⁶、Z⁷、Z⁸、Z⁹、Z¹⁰、Z¹¹、Z¹²And Z¹³At least two of which are N atoms.

Preferably, Ar is²One selected from the following substituted or unsubstituted groups: preference is given to quinazolines, quinoxalines and triazines

Preferably, said L²Any one selected from a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted biphenylene group, and a substituted or unsubstituted pyridylene group.

Preferably, said L¹Selected from a single bond or a substituted or unsubstituted phenylene group.

Preferably, the compound has any one of the following structures represented by P1 to P109:

the second purpose of the invention is to provide the application of the compound in the first purpose, and the compound is applied to an organic electroluminescent device.

Preferably, the compound is used as a material of a light emitting layer, preferably as a host material of the light emitting layer, in an organic electroluminescent device.

It is a further object of the present invention to provide an organic electroluminescent device comprising a first electrode, a second electrode and at least one organic layer interposed between the first electrode and the second electrode, the organic layer comprising at least one compound according to one of the objects.

Preferably, the organic layer includes a light-emitting layer containing at least one compound described for one of the purposes.

Preferably, the compound serves as a host material of the light-emitting layer.

In one embodiment, the organic layer may further include a hole transport region and an electron transport region.

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 having excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a Thin Film Transistor (TFT) may be provided on a substrate for a display.

The first electrode may be used as the first electrode by sputtering or deposition on the substrateThe material of the electrodes. When the first electrode is used as an anode, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), tin dioxide (SnO) may be used₂) And transparent conductive oxide materials such as zinc oxide (ZnO), and any combination thereof. When the first electrode is used as a cathode, a metal or an alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), or any combination thereof can be used.

The organic layer may be formed on the electrode by vacuum thermal evaporation, spin coating, printing, or the like. The compounds used as the organic layer may be small organic molecules, large organic molecules, and polymers, and combinations thereof.

The hole transport region is located between the anode and the light emitting layer. The hole transport region may be a Hole Transport Layer (HTL) of a single layer structure including a single layer containing only one compound and a single layer containing a plurality of compounds. The hole transport region may also 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).

The material of 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 polyphenylenevinylene, 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 including compounds shown below as HT-1 to HT-34; or any combination thereof.

The hole injection layer is located between the anode and the hole transport layer. The hole injection layer may be a single compound material or a combination of a plurality of compounds. For example, the hole injection layer may employ one or more compounds of HT-1 to HT-34 described above, or one or more compounds of HI-1 to HI-3 described below; one or more of the compounds HT-1 to HT-34 may also be used to dope one or more of the compounds HI-1 to HI-3 described below.

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 may be a single color light emitting layer emitting a single color of red, green, blue, or the like. The single color light emitting layers of a plurality of different colors may be arranged in a planar manner in accordance with a pixel pattern, or may be stacked to form a color light emitting layer. When the light emitting layers of different colors are stacked together, they may be spaced apart from each other or may be connected to each other. The light-emitting layer may be a single color light-emitting layer capable of emitting red, green, blue, or the like at the same time.

According to different technologies, the luminescent layer material can be different materials such as fluorescent electroluminescent material, phosphorescent electroluminescent material, thermal activation delayed fluorescent luminescent material, and the like. In an OLED device, a single light emitting technology may be used, or a combination of a plurality of different light emitting technologies may be used. These technically classified different luminescent materials may emit light of the same color or of different colors.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light emitting layer thereof may be selected from, but not limited to, a combination of one or more of RPD-1 to RPD-28 listed below.

The electron transport region may be an Electron Transport Layer (ETL) of a single-layer structure including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing a plurality of compounds. The electron transport region may also 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).

In one aspect of the invention, the electron transport layer material may be selected from, but is not limited to, the combination of one or more of ET-1 through ET-57 listed below.

An electron injection layer may also be included in the device between the electron transport layer and the cathode, the electron injection layer materials including, but not limited to, combinations of one or more of the following.

Liq、LiF、NaCl、CsF、Li₂O、Cs₂CO₃、BaO、Na、Li、Ca。

The cathode is metal, metal mixture or oxide such as magnesium silver mixture, LiF/Al, ITO, etc.

Compared with the prior art, the invention has the following beneficial effects:

The purpose of this design is that the carbazole ensures the corresponding HOMO level, providing good performanceThe hole transmission ability of (1), the addition of the structure that formula II shows provides bigger plane conjugate group, has increased the carrier mobility of whole molecule, moreover this kind of introduction of rigid structure for this kind of material has high vitrification temperature, and thermal stability is splendid, when being applied to OLED device, can effectual improvement device efficiency, reduces driving voltage, increase of service life.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

The synthesis of the compounds of formula I of the present invention is represented as follows:

the above symbols all have the same meaning as in formula I and formula II.

Compounds of synthetic methods not mentioned in the following synthetic examples of the present invention are all commercially available starting products. The solvents and reagents used in the present invention, such as methylene chloride, ethanol, 1, 8-dibromonaphthalene, phenylboronic acid, carbazole, and other chemical reagents, are commercially available from the national chemical product markets, such as from national drug group reagents, TCI, Shanghai Bide pharmaceuticals, and Bailingwei reagents. In addition, they can be synthesized by a known method by those skilled in the art.

Synthesis of intermediate M1-M4:

1, 8-dibromonaphthalene (0.1mol, 1eq), phenylboronic acid (0.1mol, 1eq), potassium carbonate (0.2mol, 2eq), tetrakis (triphenylphosphine) palladium (0.001mol, 0.01eq), dioxane (300mL) and water (50mL) were added to a three-necked flask. The oil bath was heated to 90 ℃ for 6 hours and the reaction was monitored by TLC. The reaction solution was cooled to room temperature, and the solvent was removed by rotary evaporation under reduced pressure. And purifying the obtained crude product by column chromatography to obtain an intermediate M-A.

M-A (0.08mol, 1eq), pinacol o-aminobenzeneboronic acid ester (0.1mol, 1.2eq), potassium carbonate (0.12mol, 1.5eq), tetrakis (triphenylphosphine) palladium (0.0008mol, 0.01eq), dioxane (250mL) and water (40mL) were added to a three-necked flask. The reaction was heated to 110 ℃ for 6 hours in an oil bath and monitored by Thin Layer Chromatography (TLC) for completion. And cooling the reaction liquid to room temperature, and carrying out reduced pressure rotary evaporation to remove the solvent to obtain a crude product, and carrying out column chromatography purification to obtain an intermediate M-B.

Adding M-B (0.05mol) into 200mL of acetic acid, adding sulfuric acid (0.25mol), cooling to 10 ℃, dropwise adding a sodium nitrite aqueous solution (0.1mol), recovering the reaction at room temperature for 4h, detecting by a gas chromatography-mass spectrometer (GC-MS) to confirm that the reaction is complete, and purifying the intermediate M by column chromatography.

The following intermediate was obtained by replacing only the pinacol ester of ortho-aminophenylboronic acid with the equivalent amount of the pinacol ester of chloro-ortho-aminophenylboronic acid according to the same method as described above:

synthesis of intermediate M5:

adding M (0.05mol) into 200mL of Dimethylformamide (DMF), cooling to 0 ℃, dropwise adding N-bromosuccinimide (NBS) solution (0.075mol) in DMF, recovering to room temperature for reaction for 4h, detecting by GC-MS to confirm that the reaction is complete, and purifying by column chromatography to obtain an intermediate M5.

Synthesis of intermediate M6:

adding (0.1mol) 2-nitro-1-naphthol into 300mL dichloromethane, adding triethylamine (0.15mol), cooling to 0 ℃, dropwise adding 0.2mol trifluoromethanesulfonic anhydride, reacting at room temperature for 2h after dropwise addition, monitoring by TLC to complete reaction, slowly adding water to separate an organic phase, concentrating to obtain brown oily matter, and heating petroleum ether to obtain a yellow solid after boiling.

M6-A (0.1mol, 1eq), 2'- (pinacolato-2-yl borate) - [1,1' -biphenyl ] -2-amine (0.12mol, 1.2eq), potassium carbonate (0.15mol, 1.5eq), tetrakis (triphenylphosphine) palladium (0.001mol, 0.01eq), dioxane (250mL), and water (40mL) were added to a three-necked flask. The oil bath was heated to 110 ℃ for 6 hours and the reaction was monitored by TLC. And cooling the reaction liquid to room temperature, and carrying out reduced pressure rotary evaporation to remove the solvent to obtain a crude product, and carrying out column chromatography purification to obtain an intermediate M6-B.

M6-B (0.05mol, 1eq), sulfuric acid (0.1mol), acetic acid (200mL) were added to a three-necked flask. And cooling to 10 ℃, dropwise adding a sodium nitrite aqueous solution (0.1mol), reacting at room temperature for 2h after dropwise adding is finished, and monitoring the reaction completion by TLC. Adding water and ethyl acetate for extraction, decompressing and rotary distilling to remove the solvent to obtain a crude product, and carrying out column chromatography purification to obtain an intermediate M6-C.

Adding M6-C (0.04mol, 1eq), iron powder (0.2mol) and ethanol (200mL) into a three-neck flask, heating and refluxing for reaction for 24 hours, directly spin-drying the ethanol after the reaction is completed, washing residues with dichloro, and concentrating an organic phase to obtain a brown oily substance M6-D.

Adding M6-D (0.04mol), cuprous bromide (0.1mol) and hydrochloric acid (0.1mol) into 200mL of acetonitrile, cooling to 0 ℃, dropwise adding tert-butyl nitrite (0.1mol), reacting at 50 ℃ for 4h after dropwise adding, monitoring by GC-MS that the reaction is complete, and carrying out column chromatography to obtain an intermediate M6.

Synthesis example 1

Synthesis of Compound P6

Adding indolo [2,3-A ] carbazole (10mmol), M5(10mmol), sodium tert-butoxide (20mmol), tris (dibenzylideneacetone) dipalladium (0.1mmol), tri-tert-butylphosphine (0.2mmol) and 200mL of xylene into a reaction bottle, heating to 120 ℃ for reaction for 6h, monitoring the reaction by TLC, cooling, adding water and dichloromethane, separating an organic phase, concentrating, and purifying by column chromatography to obtain the compound P6-A.

Adding P6-A (6mmol), 2-chloro 4-phenylquinazoline (6mmol), sodium tert-butoxide (10mmol), tris (dibenzylideneacetone) dipalladium (0.1mmol), tri-tert-butylphosphine (0.2mmol) and 150mL of xylene into a reaction bottle, heating to 150 ℃ for reaction for 8h, monitoring the reaction by TLC, cooling, adding water and dichloromethane, separating an organic phase, concentrating, and purifying by column chromatography to obtain the compound P6.

Synthesis example 2:

synthesis of Compound P34

Adding indolo [2,3-B ] carbazole (10mmol), M5(10mmol), sodium tert-butoxide (20mmol), tris (dibenzylideneacetone) dipalladium (0.1mmol), tri-tert-butylphosphine (0.2mmol) and 200mL of xylene into a reaction bottle, heating to 120 ℃ for reaction for 6h, monitoring the reaction by TLC, cooling, adding water and dichloromethane, separating an organic phase, concentrating, and purifying by column chromatography to obtain the compound P34-A.

Adding 34-A (6mmol), 2-chloro-3-phenylquinoxaline (6mmol), sodium tert-butoxide (10mmol), tris (dibenzylideneacetone) dipalladium (0.1mmol), tri-tert-butylphosphine (0.2mmol) and 150mL of xylene into a reaction bottle, heating to 150 ℃ for reaction for 8h, monitoring the reaction by TLC, cooling, adding water and dichloromethane, separating an organic phase, concentrating, and purifying by column chromatography to obtain the compound P34.

Synthesis example 3:

synthesis of Compound P54

The difference from synthesis example 1 is that indolo [2,3-A ] carbazole was replaced with indolo [2,3-C ] carbazole in an amount equivalent to that of synthesis example, to obtain compound P54.

Synthesis example 4:

synthesis of Compound P62

The difference from Synthesis example 3 is that 2-chloro-4-phenylquinazoline was replaced with an equivalent amount of 2-chloro-3-phenylquinoxaline to give compound P62.

Synthesis example 5:

synthesis of Compound P74

Adding indolo [2,3-C ] carbazole (10mmol), M3(10mmol), sodium tert-butoxide (20mmol), tris (dibenzylideneacetone) dipalladium (0.1mmol), tri-tert-butylphosphine (0.2mmol) and 200mL of xylene into a reaction bottle, heating to 150 ℃ for reaction for 6h, monitoring the reaction by TLC, cooling, adding water and dichloromethane, separating an organic phase, concentrating, and purifying by column chromatography to obtain the compound P74-A.

Adding P74-A (6mmol), 2-chloro 4-phenylquinazoline (6mmol), sodium tert-butoxide (10mmol), tris (dibenzylideneacetone) dipalladium (0.1mmol), tri-tert-butylphosphine (0.2mmol) and 150mL of xylene into a reaction bottle, heating to 150 ℃ for reaction for 8h, monitoring the reaction by TLC, cooling, adding water and dichloromethane, separating an organic phase, concentrating, and purifying by column chromatography to obtain the compound P74.

Synthesis example 6:

synthesis of Compound P94

Adding indolo [3,2-B ] carbazole (10mmol), M6(10mmol), sodium tert-butoxide (20mmol), tris (dibenzylideneacetone) dipalladium (0.1mmol), tri-tert-butylphosphine (0.2mmol) and 200mL of xylene into a reaction bottle, heating to 120 ℃ for reaction for 6h, monitoring by TLC to complete the reaction, cooling, directly filtering, and recrystallizing a filter cake with xylene to obtain the compound P94-A.

Adding P94-A (6mmol), 2-chloro-4, 6-diphenyl- (1,3,5) triazine (6mmol), sodium tert-butoxide (10mmol), tris (dibenzylideneacetone) dipalladium (0.1mmol), tri-tert-butylphosphine (0.2mmol) and 200mL of xylene into a reaction bottle, heating to 150 ℃ for reaction for 8h, monitoring the reaction completion by TLC, directly filtering after cooling, and recrystallizing a filter cake with xylene to obtain the compound P94.

Synthesis example 7:

synthesis of Compound P105

Adding indolo [3,2-A ] carbazole (10mmol), 2-chloro 4-phenylquinazoline (10mmol), sodium tert-butoxide (20mmol), tris (dibenzylideneacetone) dipalladium (0.1mmol), tri-tert-butylphosphine (0.2mmol) and 200mL of xylene into a reaction bottle, heating to 120 ℃ for reaction for 6h, monitoring the reaction by TLC, directly filtering after cooling, and recrystallizing a filter cake by using xylene to obtain a compound P105-A.

Adding P105-A (6mmol), M4(6mmol), sodium tert-butoxide (10mmol), tris (dibenzylideneacetone) dipalladium (0.1mmol), tri-tert-butylphosphine (0.2mmol) and 200mL of xylene into a reaction bottle, heating to 150 ℃ for reacting for 8h, monitoring by TLC to complete the reaction, cooling, directly filtering, and recrystallizing a filter cake with xylene to obtain the compound P105.

The present invention exemplarily provides specific synthetic methods for the above compounds, and compounds for which specific synthetic methods are not given in the following examples are also prepared by similar methods, and can be obtained only by replacing raw materials, which are not described herein again, or can be prepared by other methods in the prior art by those skilled in the art.

To verify the certainty of the molecular structure of the compound of formula I synthesized in the present invention, we confirmed it by elemental analysis (seimei FLASH 2000 CHNS/O organic element analyzer) and mass spectrometry information (ZAB-HS type mass spectrometer manufactured by Micromass corporation, uk), and the results are shown in table 1.

TABLE 1

Compound (I)	Elemental analysis (%)	Mass spectrum (M)/Z)
			P6	C,88.02；H,4.38；N,7.60	736.26
P34	C,88.02；H,4.38；N,7.60	736.26
			P54	C,88.02；H,4.38；N,7.60	736.26
P62	C,88.02；H,4.38；N,7.60	736.26
			P74	C,86.48；H,4.35；N,9.17	763.27
P94	C,88.02；H,4.38；N,7.60	736.26
			P105	C,88.02；H,4.38；N,7.60	736.26

Example 1

The embodiment provides an organic electroluminescent device, and the specific preparation method is as follows:

the glass plate coated with the ITO transparent conductive layer was sonicated in a commercial detergent, rinsed in deionized water, washed in acetone: ultrasonically removing oil in an ethanol mixed solvent, baking in a clean environment until the water is completely removed, cleaning by using ultraviolet light and ozone, and bombarding the surface by using low-energy cationic beams;

placing the glass substrate with the ITO anode in a vacuum chamber, and vacuumizing to<1×10^-5Pa, performing vacuum thermal evaporation on the anode layer film in sequence to obtain a 10nm HT-4: HI-3(97/3, w/w) mixture as a hole injection layer, a 60nm compound HT-4 as a hole transport layer, a 40nm compound P6: RPD-8(100:3, w/w) as a light emitting layer, a 25nm compound ET-46: ET-57(50/50, w/w) mixture as an electron transport layer, 1nm LiF as an electron injection layer, and 150nm metal aluminum as a cathode. The total evaporation rate of all the organic layers and LiF is controlled at 0.1 nm/s, and the evaporation rate of the metal electrode is controlled at 1 nm/s.

Examples 2 to 11, comparative examples 1 to 2 and example 1 differ only in that the light-emitting layer host material P6 was replaced with the light-emitting layer host material shown in table 2.

The structure of the host material of the luminescent layer in the comparative examples 1-2 is as follows:

among them, compound C1 was synthesized with reference to patent CN107200743A, and compound C2 was synthesized with reference to patent CN 107434809A.

And (3) performance testing:

(1) the organic electroluminescent devices prepared in examples and comparative examples were measured for driving voltage and current efficiency and lifetime of the devices at the same luminance using a PR 750 type photoradiometer of Photo Research, a ST-86LA type luminance meter (photoelectric instrument factory of university of beijing), and a Keithley4200 test system. Specifically, the voltage was raised at a rate of 0.1V per second, and it was determined that the luminance of the organic electroluminescent device reached 3000cd/m²The current density is measured at the same time as the driving voltage; the ratio of the brightness to the current density is the current efficiency; the current efficiency of comparative example 1 was taken as 1, and the remainder was compared withExample 1 ratio of current efficiencies.

The results of the performance tests are shown in table 2.

TABLE 2

The results in table 2 show that the novel organic materials of the present invention are useful for organic electroluminescent devices, resulting in devices having both lower driving voltage and higher current efficiency.

Compared with comparative examples 1 and 2, the luminescent layer host material used in the embodiment introduces a novel large conjugated aromatic ring, improves the plane type of molecules, improves the mobility of the molecules, is beneficial to the transmission of current carriers, increases the efficiency of devices, and reduces the driving voltage.

The present invention is illustrated in detail by the examples described above, but the present invention is not limited to the details described above, i.e., it is not intended that the present invention be implemented by relying on the details described above. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. A compound having a structure according to formula I;

in the formula I, A has a structure shown in a formula II;

in the formula II, X₁～X₁₄Independently selected from CR₁Or N, said R₁Independently selected from 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, amino, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroaryl amino and substituted or unsubstituted C3-C30 heteroaryl, wherein R is selected from the group consisting of C, B, C, B, C, B6, B₁Independently with the attached aromatic ring to form a ring or not;

in formula II, a represents a bond of the group;

R₁、L¹the substituted groups in the ring B and the ring C are independently selected from one or the combination of at least two of halogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 monocyclic heteroaryl and C6-C30 fused ring heteroaryl.

2. The compound of claim 1, wherein in formula II, X is₁～X₁₄Are all CR₁；

Preferably, said R is₁Is hydrogen.

3. The compound of claim 1, wherein ring B and ring C are independently selected from one of a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted group of formula III;

4. A compound according to claim 3, wherein at least one of ring B and ring C is a substituted or unsubstituted group of formula III;

5. The compound according to claim 3 or 4, wherein in formula III, ring D represents a substituted or unsubstituted benzene ring.

6. A compound according to any one of claims 3 to 5 wherein at least one of X and Y in formula III is N-L²-Ar²；

Preferably, in formula III, X and Y are independently selected from a single bond or N-L²-Ar²；

Preferably, in formula III, X is a single bond and Y is N-L²-Ar²。

7. The compound of claim 3, wherein the compound has the structure of formula I-1;

in the formula I-1, A and L¹Both having the same limitations as in formula I, and both rings D, X and Y having the same limitations as in formula III.

8. The compound of claim 7, wherein the compound has a structure represented by formula (a) through formula (f):

structures of formula (a) and formula (b) are preferred;

a and L¹All having the same limits as in formula I, Ar²And L²All having the same limitations as in formula III.

9. A compound according to any one of claims 3 to 8 wherein Ar is Ar²Selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted triazinyl, substituted or unsubstitutedAny one of a pyridyl group, a substituted or unsubstituted pyrimidyl group, and a substituted or unsubstituted quinolyl group.

10. A compound according to any one of claims 3 to 8 wherein Ar is Ar²Selected from substituted or unsubstituted C3-C30 electron-deficient heteroaryl groups, preferably nitrogen-containing substituted or unsubstituted C3-C30 electron-deficient heteroaryl groups;

preferably, Ar is²Has one of the following structures (3-1) to (3-4):

the R is³One selected from the group consisting 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, amino, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl;

wherein represents an access bond to a group;

preferably, Ar is²Has the structure shown in (3-1) or (3-2).

11. A compound according to any one of claims 3 to 8 and 10 wherein Ar is Ar²One selected from the following substituted or unsubstituted groups: pyridyl, quinolyl, quinazolinyl, triazinyl, pyrimidinyl or quinoxalinyl.

12. The compound of claim 10, wherein Ar is²Has a structure represented by (3-1) or (3-2):

in the formula (3-1), Z¹、Z²、Z³、Z⁴And Z⁵At least two of which are N atoms; and/or, in the formula (3-2), Z⁶、Z⁷、Z⁸、Z⁹、Z¹⁰、Z¹¹、Z¹²And Z¹³At least two of which are N atoms;

preferably, Ar is²One selected from the following substituted or unsubstituted groups: quinazolines, quinoxalines and triazines are preferred.

13. According to claims 3E12, the compound of any one of claims 12, wherein L is²Any one selected from a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted biphenylene group, and a substituted or unsubstituted pyridylene group.

14. The compound of claim 1, wherein L is¹Selected from a single bond or a substituted or unsubstituted phenylene group.

15. The compound of claim 1, having any one of the following structures P1-P109:

16. use of a compound according to any one of claims 1 to 15 in an organic electroluminescent device;

17. An organic electroluminescent device comprising 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 any one of claims 1 to 15;

preferably, the organic layer comprises a light-emitting layer containing at least one compound according to any one of claims 1 to 15;

preferably, the compound serves as a host material of the light-emitting layer.