CN112778300A

CN112778300A - Organic compound and organic electroluminescent device containing the same

Info

Publication number: CN112778300A
Application number: CN201911073852.2A
Authority: CN
Inventors: 孙恩涛; 方仁杰; 刘叔尧; 吴俊宇
Original assignee: Beijing Eternal Material Technology Co Ltd
Current assignee: Beijing Eternal Material Technology Co Ltd
Priority date: 2019-11-05
Filing date: 2019-11-05
Publication date: 2021-05-11
Anticipated expiration: 2039-11-05
Also published as: CN112778300B

Abstract

An organic compound having a structure represented by (1):

wherein L is₁And L₂Each independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene, or a substituted or unsubstituted C3-C30 heteroarylene; ar (Ar)₁And Ar₂Each independently selected from substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl; r is halogen, C1-C30 alkyl, C3-C30 cycloalkyl,C1-C30 alkoxy, amino, C6-C30 arylamine or nitro; p and n are respectively integers of 0-6, p + n is less than or equal to 6, and when p is 0, L₁Is not a single bond; when each of the above-mentioned substituted or unsubstituted groups has a substituent, the substituent is selected from one or a combination of plural kinds of halogen, C1-C30 alkyl, C3-C30 cycloalkyl, C2-C30 alkenyl, C2-C30 alkynyl, cyano, nitro, C1-C30 alkoxy, C1-C30 thioalkoxy, C6-C30 aryl and C3-C60 heteroaryl. The present application also relates to an organic electroluminescent device using the above organic compound.

Description

Organic compound and organic electroluminescent device containing the same

Technical Field

The invention relates to a novel organic compound, in particular to an organic compound and application thereof in an organic electroluminescent device.

Background

Organic Light Emission Diodes (OLED) devices are a kind of devices with sandwich-like structure, which includes positive and negative electrode films and Organic functional material layers sandwiched between the electrode films. And applying voltage to the electrodes of the OLED device, injecting positive charges from the positive electrode and injecting negative charges from the negative electrode, and transferring the positive charges and the negative charges in the organic layer under the action of an electric field to meet for composite luminescence. Because the OLED device has the advantages of high brightness, fast response, wide viewing angle, simple process, flexibility and the like, the OLED device is concerned in the field of novel display technology and novel illumination technology. At present, the technology is widely applied to display panels of products such as novel lighting lamps, smart phones and tablet computers, and further expands the application field of large-size display products such as televisions, and is a novel display technology with fast development and high technical requirements.

With the continuous advance of OLEDs in both lighting and display areas, much attention has been paid to the research on their core materials. This is because an efficient, long-lived OLED device is generally the result of an optimized configuration of the device structure and various organic materials, which provides great opportunities and challenges for chemists to design and develop functional materials with various structures. Common functionalized organic materials are: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, and light emitting host materials and light emitting objects (dyes), and the like.

In order to prepare an OLED light-emitting device with lower driving voltage, better light-emitting efficiency and longer service life, the performance of the OLED device is continuously improved, the structure and the manufacturing process of the OLED device need to be innovated, and photoelectric functional materials in the OLED device need to be continuously researched and innovated, so that functional materials with higher performance can be prepared. Based on this, the OLED material industry has been working on developing new organic electroluminescent materials to achieve low driving voltage, high luminous efficiency and better lifetime of the device.

In the current OLED panel manufacturers, the commonly used electron transport materials include single oxazole, thiazole, imidazole, triazole or triazine structures.

Disclosure of Invention

Problems to be solved by the invention

However, in order to further satisfy the increasing demand for the photoelectric properties of OLED devices and the demand for energy saving of mobile electronic devices, new and efficient OLED materials are continuously developed, wherein the development of new electron transport materials with high electron injection capability and high mobility is of great importance.

Means for solving the problems

In order to solve the problems in the prior art, the inventors have intensively studied and found that the introduction of a conjugated group at a specific position of a quinolinecarbonyl-substituted imidazole structure provides a molecule with good plane conjugation, which is advantageous for improving the mobility of electrons, and particularly, the introduction of an electron-deficient conjugated group is advantageous for improving the electron injection and migration performance, thereby obtaining a compound with excellent performance that can be used in organic electronic devices.

Specifically, the present invention provides an organic compound having a structure represented by (1):

wherein L is₁And L₂Each independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene, or a substituted or unsubstituted C3-C30 heteroarylene; ar (Ar)₁And Ar₂Each independently selected from substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl; r is halogen, C1-C30 alkyl, C3-C30 cycloalkyl, C1-C30 alkoxyAmino, C6-C30 arylamine or nitro; p and n are respectively integers of 0-6, p + n is less than or equal to 6, and when p is 0, L₁Is not a single bond; when each of the above-mentioned substituted or unsubstituted groups has a substituent, the substituent is selected from one or a combination of plural kinds of halogen, C1-C30 alkyl, C3-C30 cycloalkyl, C2-C30 alkenyl, C2-C30 alkynyl, cyano, nitro, C1-C30 alkoxy, C1-C30 thioalkoxy, C6-C30 aryl and C3-C60 heteroaryl.

The specific reason why the compound of the general formula of the present invention is excellent as an electron transport layer material in an organic electroluminescent device is not clear, and the following reason is presumed: the compound of the general formula has a core with a quinoline cyano-substituted imidazole structure, has good electron deficiency, and is beneficial to electron injection, and the aryl or heteroaryl conjugated structure is connected to a specific position of the core to expand a conjugated system of the core, so that molecules have good plane conjugation, and particularly the combination of the core and electron deficiency conjugated groups such as triazine, quinazoline, cyano and the like at the specific position enables the compound of the general formula to have stronger electron deficiency, thereby being beneficial to electron injection. Therefore, under the synergistic effect of the above characteristics, when the compound of the general formula is used as an electron transport layer material of an organic electroluminescent device, the electron injection and migration efficiency in the device can be effectively improved, thereby ensuring that the device obtains excellent effects of high luminous efficiency and low driving voltage.

Furthermore, the inventors have found that, in the compounds of the above general formula, when the quinoline ring of the mother nucleus is not linked to an aryl or heteroaryl group (i.e., p ═ 0, and therefore the aryl or heteroaryl group must be directly or indirectly linked to the imidazole ring), if the aryl or heteroaryl group is directly linked to the imidazole ring (i.e., L is L)₁A single bond), the luminous efficiency, driving voltage, etc. of an organic electroluminescent device using the corresponding compound as an electron transport layer material are insufficient compared to the case where an aryl or heteroaryl group is linked to an imidazole ring via an arylene or heteroarylene group and an aryl or heteroaryl group is linked to a quinoline ring. The reason for this is not clear, and may be caused by insufficient conjugation due to steric hindrance in direct connection. In addition, the above-mentioned aryl or heteroaryl group is directly attached to the imidazoleThe synthesis of the azole ring compounds is difficult, which may also be due to steric hindrance.

In the present invention, the term "electron-deficient substituent" means a group in which the electron cloud density on the benzene ring is reduced after the hydrogen on the benzene ring is substituted with the group, and usually, the Hammett value of such a group is more than 0.6. The Hammett value is a representation of the charge affinity for a particular group and is a measure of the electron withdrawing group (positive Hammett value) or electron donating group (negative Hammett value). The Hammett equation is described In more detail In Thomas H.Lowry and Kathelen Schueler Richardson, "mechanics and Theory In Organic Chemistry', New York, 1987, 143-. Such groups may be listed but are not limited to: triazinyl, pyrimidinyl, benzopyrimidinyl, benzopyridyl, naphthyridinyl, phenanthridinyl, pyrazinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, pyridazinyl, and alkyl-or aryl-substituted ones of the foregoing.

In the present specification, the expression of Ca to Cb means that the group has carbon atoms of a to b, and the carbon atoms do not generally include the carbon atoms of the substituents unless otherwise specified. In the present invention, the expression of chemical elements includes the concept of chemically identical isotopes, such as the expression of "hydrogen", and also includes the concept of chemically identical "deuterium" and "tritium".

In the present specification, the expression of the loop structure marked by "-" indicates that the linking site is located at any position on the loop structure where the linking site can form a bond.

In the present specification, the C6 to C30 aryl group is a group selected from the group consisting of phenyl, naphthyl, anthracenyl, benzanthracenyl, phenanthrenyl, benzophenanthrenyl, pyrenyl, grotto, perylenyl, fluoranthenyl, tetracenyl, pentacenyl, benzopyrenyl, biphenyl, idophenyl, terphenyl, quaterphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthrenyl, dihydropyrenyl, tetrahydropyrenyl, cis-or trans-indenofluorenyl, triindenyl, isotridendenyl, spirotrimerization indenyl, and spiroisotridendenyl. Specifically, the biphenyl group is selected from 2-biphenyl, 3-biphenyl, and 4-biphenyl; terphenyl 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 a 1-naphthyl group or a 2-naphthyl group; the anthracene group is selected from 1-anthracene group, 2-anthracene group and 9-anthracene group; the fluorenyl group is selected from the group consisting of 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, and 9-fluorenyl; the pyrenyl group is selected from 1-pyrenyl, 2-pyrenyl and 4-pyrenyl; the tetracene group is selected from the group consisting of 1-tetracene, 2-tetracene, and 9-tetracene. C6-C30 arylene is similar to C6-C30 aryl, provided that the above groups are changed to the corresponding subunits.

The hetero atom in the present invention generally refers to an atom or group of atoms selected from N, O, S, P, Si and Se, preferably N, O, S.

In the present specification, examples of the heteroaryl group having from C3 to C30 include: nitrogen-containing heteroaryl, oxygen-containing heteroaryl, sulfur-containing heteroaryl, and the like, and specific examples thereof include: furyl, thienyl, pyrrolyl, pyridyl, benzofuryl, benzothienyl, isobenzofuryl, isobenzothienyl, indolyl, isoindolyl, dibenzofuryl, dibenzothienyl, carbazolyl and derivatives thereof, quinolyl, isoquinolyl, acridinyl, phenanthridinyl, benzo-5, 6-quinolyl, benzo-6, 7-quinolyl, benzo-7, 8-quinolyl, phenothiazinyl, phenazinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthoimidazolyl, phenanthroimidazolyl, pyridoimidazolyl, pyrazinoimidazolyl, quinoxalimidazolyl, oxazolyl, benzoxazolyl, naphthooxazolyl, anthraoxazolyl, phenanthroizolyl, 1, 2-thiazolyl, 1, 3-thiazolyl, benzothiazolyl, pyridazinyl, benzpyridazinyl, Pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1, 5-diazananthracenyl, 2, 7-diazpyrenyl, 2, 3-diazpyrenyl, 1, 6-diazenyl, 1, 8-diazenyl, 4, 5, 9, 10-tetraazaperyl, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbazinyl, phenanthrolinyl, 1, 2, 3-triazolyl, 1, 2, 4-triazolyl, benzotriazolyl, 1, 2, 3-oxadiazolyl, 1, 2, 4-oxadiazolyl, 1, 2, 5-oxadiazolyl, 1, 2, 3-thiadiazolyl, 1, 2, 4-thiadiazolyl, 1, 2, 5-thiadiazolyl, 1, 3, 4-thiadiazolyl, 1, 3, 5-triazinyl, 1, 2, 4-triazinyl, 1, 2, 3-triazinyl, tetrazolyl, 1, 2, 4, 5-tetrazinyl, 1, 2, 3, 4-tetrazinyl, 1, 2, 3, 5-tetrazinyl, purinyl, pteridinyl, indolizinyl, benzothiadiazole, etc., wherein the carbazolyl derivative is preferably 9-phenylcarbazole, 9-naphthylcarbazole benzocarbazole, dibenzocarbazole, or indolocarbazole. C3-C30 heteroarylenes are similar to C3-C30 heteroarylenes, provided that the above groups are changed to the corresponding subunits.

In the present specification, examples of the C1-C30 alkyl group include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, adamantyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2, 2, 2-trifluoroethyl and the like. C1-C30 alkoxy, C1-C30 thioalkoxy are similar to C1-C30 alkyl, except that-O-and-S-are respectively added to the groups.

In the present specification, the cycloalkyl group having 3 to 30 includes monocycloalkyl groups and polycycloalkyl groups, and examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like.

In the present specification, examples of the C6 to C30 arylamine group include: diphenylamino, isopropyldiphenylamino, dinaphthylamino, naphthylanilino and the like.

In the present specification, examples of the C2 to C30 alkenyl group include: vinyl, propenyl, 1-butenyl, etc.; examples of C2-C30 alkynyl groups include: ethynyl, propynyl, 1-butynyl and the like.

In the present specification, examples of the halogen include: fluorine, chlorine, bromine, iodine, etc., preferably fluorine.

The compound of the general formula (1) of the present invention has specifically the structures (1-1) to (1-7):

the compound of the general formula (1) of the present invention is preferably Ar₁And Ar₂Each independently selected from the following substituted or unsubstituted structures:

the expression of the loop structure is indicated by a dotted line in the above structure, which indicates that the linking site may be located at any position on the loop structure where the linking site can form a bond.

The compound of the general formula (1) of the present invention is preferably Ar₁And/or Ar₂The electron-deficient group can increase the electron affinity of the molecule and adjust the dipole moment of the molecule, thereby being beneficial to improving the injection and migration capability of electrons.

The compound of the general formula (1) of the present invention is preferably L₁And L₂Each independently selected from single bond, phenylene or biphenylene, can enable the plane to have a certain twist angle, and avoid the effect that molecules are excessively stacked to easily cause quenching, thereby influencing the efficiency of the device.

The compound of the general formula (1) is preferably 0n, so that the prepared device has good performance, and the molecular structure is simple and convenient to synthesize.

The compounds of the general formula (1) according to the present invention are preferably selected from the following structures represented by C1 to C94, but these compounds are representative only:

the compound of the present invention has a high electron affinity, and therefore has a high electron-withdrawing ability, and is suitable for use as an electron transport material, and the application field is not limited to organic electroluminescent materials, and can be applied to the technical fields of large-area sensors such as optical sensors, solar cells, lighting devices, organic thin-film transistors, organic field-effect transistors, organic thin-film solar cells, information tags, electronic artificial skin sheets, sheet-type scanners, and electronic paper.

The invention also provides an organic electroluminescent device which comprises a first electrode, a second electrode and at least one organic layer positioned between the first electrode and the second electrode, and is characterized in that the organic layer contains the organic compound.

Specifically, the invention provides an organic electroluminescent device, which comprises a substrate, and an anode layer, a plurality of light-emitting functional layers and a cathode layer which are sequentially formed on the substrate; the light-emitting functional layer comprises a hole injection layer, a hole transport layer, a light-emitting layer and an electron transport layer, wherein the hole injection layer is formed on the anode layer, the hole transport layer is formed on the hole injection layer, the cathode layer is formed on the electron transport layer, and the light-emitting layer is arranged between the hole transport layer and the electron transport layer; wherein the electron transport layer contains the compound of the general formula of the present invention represented by the above formula (1).

Effects of the invention

The general formula compound adopts the combination of quinoline cyano substituted imidazole and electron-deficient groups such as triazine, quinazoline, cyano and the like, and compared with the common structures of single oxazole, thiazole, imidazole, triazole or triazine in the prior art, the structure of the compound has relatively stronger electron-deficient property, thereby being beneficial to the injection of electrons. Meanwhile, the compound contains electron-deficient groups with large conjugated structures, so that molecules have good plane conjugation, and the mobility of electrons is improved. The structural characteristics of the two aspects can make the molecule show good electron injection and migration performance. Therefore, when the compound is used as an electron transport layer material in an organic electroluminescent device, the electron injection and migration efficiency in the device can be effectively improved, so that the excellent effects of high luminous efficiency and low driving voltage of the device are ensured.

In addition, the preparation process of the compound is simple and feasible, the raw materials are easy to obtain, and the compound is suitable for mass production and amplification.

Detailed Description

The technical solutions of the present invention are further illustrated below by specific embodiments, and 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 specifically limiting the present invention.

The basic chemical materials used in the following synthesis examples, such as ethyl acetate, sodium sulfate, toluene, tetrahydrofuran, dichloromethane, acetic acid, potassium carbonate, were purchased from Shanghai Tantake technology Co., Ltd and Xiong chemical Co., Ltd. The mass spectrometer used for determining the following compounds was a ZAB-HS type mass spectrometer measurement (manufactured by Micromass, UK).

Synthesis of intermediate M:

2-methylquinoline derivative M-1(0.1mol, 1eq), arylbenzylamine M-2(0.3mol, 3eq), TMSCN (0.3mol, 3eq), NH₄I(0.02mol，0.2eq)，Ph₂PO₂H (0.1mol, 1eq) and NH₄BF₄(0.1mol, 1eq) was added to a three-necked flask equipped with a platinum electrode containing DMA (1L). Under the catalysis of electricity (J is 10 mA/cm)²) Oil bathHeating to 90 ℃ for reaction for 15-24 hours, and monitoring the reaction completion by TLC. The reaction solution was cooled to room temperature, and the solvent was removed by rotary evaporation under reduced pressure. 1.5L of water was added and extracted with ethyl acetate (1L. times.3). And (3) combining ethyl acetate phases, drying the ethyl acetate phases by using anhydrous sodium sulfate, performing suction filtration, performing rotary evaporation to remove ethyl acetate, and performing column chromatography purification on the obtained crude product to obtain an intermediate M.

Synthesis example 1: synthesis of Compound C2

(1) Preparation of Compound 1-1

2-methylquinoline (14.3g, 0.1mol, 1eq), 4-bromobenzylamine (55.5g, 0.3mol, 3eq), TMSCN (30g, 0.3mol, 3eq), NH₄I(2.9g，0.02mol，0.2eq)，Ph₂PO₂H (21.8g, 0.1mol, 1eq) and NH₄BF₄(10.5g, 0.1mol, 1eq) was added to a three-necked flask equipped with a platinum electrode containing DMA (1L). Under the catalysis of electricity (J is 10 mA/cm)²) The oil bath was heated to 90 ℃ for 20 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. 1.5L of water was added and extracted with ethyl acetate (1L. times.3). The ethyl acetate phases were combined, dried over anhydrous sodium sulfate, filtered with suction, ethyl acetate removed by rotary evaporation, and the crude product was purified by column chromatography to give intermediate 1-1(27.2g, 80% yield).

(2) Preparation of Compound C2

Compound 1-1(6.2g, 18mmol), compound 2- (4-boronic acid pinacol group) phenyl-4, 6-diphenyl-1, 3, 5-triazine (7.8g, 18mmol), potassium carbonate (7.45g, 54mmol), pd (PPh)₃)₄(208mg, 0.18mmol) was added to a flask containing 100mL of toluene and 25mL of ethanol and 25mL of water, the nitrogen was replaced and the reaction was heated under nitrogen at reflux for 5 hours and TLC showed completion. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to give compound C2(8.9g, yield 86%). Calculated molecular weight: 576.21, found C/Z: 576.2.

synthesis example 2: synthesis of Compound C22

(1) Preparation of Compound 2-1

2-methylquinoline (14.3g, 0.1mol, 1eq), 3-chlorobenzylamine (42.3g, 0.3mol, 3eq), TMSCN (30g, 0.3mol, 3eq), NH₄I(2.9g，0.02mol，0.2eq)，Ph₂PO₂H (21.8g, 0.1mol, 1eq) and NH₄BF₄(10.5g, 0.1mol, 1eq) was added to a three-necked flask equipped with a platinum electrode containing DMA (1L). Under the catalysis of electricity (J is 10 mA/cm)²) The oil bath was heated to 90 ℃ for 22 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. 1.5L of water was added and extracted with ethyl acetate (1L. times.3). The ethyl acetate phases were combined, dried over anhydrous sodium sulfate, filtered off with suction and the ethyl acetate removed by rotary evaporation, and the crude product was purified by column chromatography to give intermediate 2-1(18.2g, yield 60%).

(2) Preparation of Compound 2-2

Compound 2-1(15.5g, 50mmol), pinacol diboron ester (19g, 75mmol) and potassium acetate (14.7g, 150mmol) were charged into a flask containing 1, 4-dioxane (300mL), and after replacing nitrogen with stirring at room temperature, palladium acetate (224mg, 1mmol) and SPhos (820mg, 2mmol) were added. After the addition was complete, the reaction was refluxed with stirring for 4 hours, and the end of the reaction was monitored by TLC. The 1, 4-dioxane was removed by rotary evaporation, the mixture was separated with water and dichloromethane, the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 2-2(16.7g, yield 85%).

(3) Preparation of Compound C22

The compound 2-2(7.1g, 18mmol), the compound 2- (3-bromophenyl) -4, 6-diphenyl-1, 3, 5-triazine (7.0g, 18mmol), potassium carbonate (7.45g, 54mmol), pd (PPh)₃)₄(208mg, 0.18mmol) was added to a flask containing 100mL of toluene and 25mL of ethanol and 25mL of water, the nitrogen was replaced and the reaction was heated under nitrogen at reflux for 7 hours and TLC showed completion. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to give compound C22(8.5g, yield 82%). Calculation of molecular weightThe value: 576.21, found C/Z: 576.2.

synthesis example 3: synthesis of Compound C41

(1) Preparation of Compound 3-1

The compound 4- (4-bromophenyl) benzonitrile (25.7g, 0.1mol), 3-methyl-4-chloro-phenylboronic acid (107g, 0.4mol), potassium carbonate (17g, 0.1mol), pd (PPh)₃)₄(1155mg, 1mmol) was added to a flask containing toluene/ethanol/water 400mL/100mL/100mL, the nitrogen was replaced and the reaction was heated to reflux under nitrogen for 4 hours and TLC indicated completion. Cooling to room temperature, separating, extracting water phase with ethyl acetate, combining organic phases, drying with anhydrous sodium sulfate, and purifying by column chromatography to obtain compound 3-1(25g, 83%).

(2) Preparation of Compound 3-2

Compound 3-1(15.2g, 50mmol), pinacol diboron ester (19g, 75mmol) and potassium acetate (14.7g, 150mmol) were charged into a flask containing 1, 4-dioxane (300mL), and after replacing nitrogen with stirring at room temperature, palladium acetate (224mg, 1mmol) and SPhos (820mg, 2mmol) were added. After the addition was complete, the reaction was refluxed with stirring for 8 hours, and the end of the reaction was monitored by TLC. The 1, 4-dioxane was removed by rotary evaporation, the mixture was separated with water and dichloromethane, the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 3-2(17g, yield 86%).

(3) Preparation of Compound C41

Mixing compound 1-1(6.2g, 18mmol), compound 3-2(7.1g, 18mmol), potassium carbonate (7.45g, 54mmol), pd (PPh)₃)₄(208mg, 0.18mmol) was added to a flask containing 100mL of toluene and 25mL of ethanol and 25mL of water, the nitrogen was replaced and the reaction was heated under nitrogen at reflux for 6 hours and TLC showed completion. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to give compound C41(8.4g, yield 87%). Calculated molecular weight: 536.20, found C/Z: 536.2.

synthesis example 4: synthesis of Compound C51

(1) Preparation of Compound 4-1

2-methyl-6-bromoquinoline (22.1g, 0.1mol, 1eq), benzylamine (32.1g, 0.3mol, 3eq), TMSCN (30g, 0.3mol, 3eq), NH₄I(2.9g，0.02mol，0.2eq)，Ph₂PO₂H (21.8g, 0.1mol, 1eq) and NH₄BF₄(10.5g, 0.1mol, 1eq) was added to a three-necked flask equipped with a platinum electrode containing DMA (1L). Under the catalysis of electricity (J is 10 mA/cm)²) The oil bath was heated to 90 ℃ for 18 h 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. 1.5L of water was added and extracted with ethyl acetate (1L. times.3). The ethyl acetate phases were combined, dried over anhydrous sodium sulfate, filtered under suction and the ethyl acetate removed by rotary evaporation, and the crude product was purified by column chromatography to give intermediate 4-1(31.2g, 90% yield).

(2) Preparation of Compound C51

The compound 4-1(6.2g, 18mmol), the compound 2- (4-boronic acid pinacol group) phenyl-4, 6-diphenyl-1, 3, 5-triazine (7.8g, 18mmol), potassium carbonate (7.45g, 54mmol), pd (PPh)₃)₄(208mg, 0.18mmol) was added to a flask containing 100mL of toluene and 25mL of ethanol and 25mL of water, the nitrogen was replaced and the reaction was heated under nitrogen at reflux for 7 hours and TLC showed completion. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to give compound C51(8.6g, yield 83%). Calculated molecular weight: 576.21, found C/Z: 576.2.

synthesis example 5: synthesis of Compound C71

(1) Preparation of Compound 5-1

2-methyl-4-chloro-quinoline (17.7g, 0.1mol, 1eq), benzylamine (32.1g, 0.3mol, 3eq), TMSCN (30g, 0.3mol, 3eq), NH₄I(2.9g，0.02mol，0.2eq)，Ph₂PO₂H (21.8g, 0.1mol, 1eq) and NH₄BF₄(10.5g, 0.1mol, 1eq) was added to a three-necked flask equipped with a platinum electrode containing DMA (1L). Under the catalysis of electricity (J is 10 mA/cm)²) The oil bath was heated to 90 ℃ for 21 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. 1.5L of water was added and extracted with ethyl acetate (1L. times.3). The ethyl acetate phases were combined, dried over anhydrous sodium sulfate, filtered off with suction and the ethyl acetate removed by rotary evaporation, and the crude product was purified by column chromatography to give intermediate 5-1(21.2g, yield 70%).

(2) Preparation of Compound 5-2

Compound 5-1(15.2g, 50mmol), pinacol diboron ester (19g, 75mmol) and potassium acetate (14.7g, 150mmol) were charged into a flask containing 1, 4-dioxane (300mL), and after replacing nitrogen with stirring at room temperature, palladium acetate (224mg, 1mmol) and SPhos (820mg, 2mmol) were added. After the addition was complete, the reaction was refluxed with stirring for 10 hours, and the end of the reaction was monitored by TLC. The 1, 4-dioxane was removed by rotary evaporation, the mixture was separated with water and dichloromethane, the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 5-2(15.8g, yield 80%).

(3) Preparation of Compound C71

The compound 5-2(7.1g, 18mmol), the compound 2- (4-bromophenyl) -4, 6-diphenyl-1, 3, 5-triazine (7g, 18mmol), potassium carbonate (7.45g, 54mmol), pd (PPh)₃)₄(208mg, 0.18mmol) was added to a flask containing 100mL of toluene and 25mL of ethanol and 25mL of water, the nitrogen was replaced and the reaction was heated under nitrogen at reflux for 4 hours and TLC showed completion. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to give compound C71(7.9g, yield 77%). Calculated molecular weight: 576.21, found C/Z: 576.2.

synthesis example 6: synthesis of Compound C46

(1) Preparation of Compound 6-1

The compound 3, 5-dibromochlorobenzene (40g, 0.15mol), 9-phenanthreneboronic acid (22.2g, 0.1mol), potassium carbonate (41.4g, 0.3mol), pd (PPh)₃)₄(1155mg, 1mmol) was added to a flask containing toluene/ethanol/water 400mL/100mL/100mL, the nitrogen was replaced and the reaction was heated to reflux under nitrogen for 3 hours and TLC indicated completion. Cooling to room temperature, separating, extracting water phase with ethyl acetate, combining organic phases, drying with anhydrous sodium sulfate, and purifying by column chromatography to obtain compound 6-1(18.3g, 50%).

(2) Preparation of Compound 6-2

Compound 6-1(18.3g, 0.05mol), phenylboronic acid (6.1g, 0.05mol), potassium carbonate (20.7g, 0.15mol), pd (PPh)₃)₄(578mg, 0.5mmol) was added to a flask containing toluene/ethanol/water 200mL/50mL/50mL, the nitrogen replaced and the reaction heated to reflux under nitrogen for 2 hours and TLC indicated completion. Cooling to room temperature, separating, extracting water phase with ethyl acetate, combining organic phases, drying with anhydrous sodium sulfate, and purifying by column chromatography to obtain compound 6-2(16.9g, 93%).

(3) Preparation of Compound 6-3

Compound 6-2(14.5g, 40mmol), pinacol diboron ester (15.2g, 60mmol) and potassium acetate (11.7g, 120mmol) were charged into a flask containing 1, 4-dioxane (200mL), and after replacing nitrogen with stirring at room temperature, palladium acetate (224mg, 1mmol) and SPhos (820mg, 2mmol) were added. After the addition was complete, the reaction was refluxed with stirring for 12 hours, and the end of the reaction was monitored by TLC. The 1, 4-dioxane was removed by rotary evaporation, the mixture was separated with water and dichloromethane, the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to give compound 6-3(15.5g, yield 85%).

(4) Preparation of Compound C46

Mixing compound 6-3(8.2g, 18mmol), compound 1-1(4.5g, 18mmol), potassium carbonate (7.45g, 54mmol), pd (PPh)₃)₄(208mg, 0.18mmol) was added to a flask containing 100mL of toluene and 25mL of ethanol and 25mL of water, the nitrogen was replaced and the reaction was heated under nitrogen at reflux for 5 hours and TLC showed completion. Filtering to obtain solid, rinsing with water and ethanol, drying, and separating by column chromatographyCompound C46 was obtained pure (9.1g, 85% yield). Calculated molecular weight: 597.22, found C/Z: 597.2.

synthesis comparative example 1: synthesis of Compound ET-Y

(1) Preparation of Compound ET-Y1

Cuprous iodide (19g, 0.1mol, 1eq), water and copper acetate (20g, 0.1mol, 1eq) were dissolved in DMSO (750ml), and then 4-bromobenzylamine (55.5g, 0.3mol, 3eq), 2-methylquinoline (14.3g, 0.1mol, 1eq), di-t-butyl peroxide DTBP (29.2g, 0.2mol, 2eq) were added to the reaction system. The oil bath was heated to 110 ℃ for 24 h and the reaction was monitored by TLC. The reaction was cooled to room temperature, 1.5L of water was added and extracted with ethyl acetate (1L x 3). The ethyl acetate phases were combined, dried over anhydrous sodium sulfate, filtered with suction, and the ethyl acetate removed by rotary evaporation, and the crude product was purified by column chromatography to give intermediate ET-Y1(27.2g, 80% yield).

(2) Preparation of Compound ET-Y

The compound ET-Y1(5.8g, 18mmol), the compound 2- (4-boronic acid pinacol group) phenyl-4, 6-diphenyl-1, 3, 5-triazine (7.8g, 18mmol), potassium carbonate (7.45g, 54mmol), pd (PPh)₃)₄(208mg, 0.18mmol) was added to a flask containing 100mL of toluene and 25mL of ethanol and 25mL of water, the nitrogen was replaced and the reaction was heated under nitrogen at reflux for 6 hours and TLC showed completion. The precipitated solid was filtered, rinsed with water and ethanol, respectively, dried and purified by column chromatography to obtain compound ET-Y (8.2g, yield 83%). Calculated molecular weight: 551.21, found C/Z: 551.2.

device embodiments

The present invention also provides an organic electroluminescent device comprising the compound of the above embodiment. An example of using an OLED as an embodiment of the organic electronic light emitting device is illustrated below. The OLED of the present embodiment includes first and second electrodes, and an organic material layer between the electrodes. The organic material may in turn be divided into a plurality of regions. For example, the organic material layer may include a hole transport region, a light emitting layer, and an electron transport region.

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 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 formed by sputtering or depositing a material used as the first electrode on the substrate. 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 material layer may be formed on the electrode by vacuum thermal evaporation, spin coating, printing, or the like. The compound used as the organic material layer may be an organic small molecule, an organic large molecule, and a polymer, and a combination 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 such as compounds shown below in 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 HI1-HI3 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 HI1-HI3 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 a fluorescent electroluminescence technique. The luminescent layer fluorescent host material may be selected from, but is not limited to, the combination of one or more of BFH-1 through BFH-16 listed below.

In one aspect of the invention, the light-emitting layer employs a fluorescent electroluminescence technique. The luminescent layer fluorescent dopant may be selected from, but is not limited to, combinations of one or more of BFD-1 through BFD-12 listed below.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The host material of the light emitting layer is selected from, but not limited to, one or more of GPH-1 to GPH-80.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light emitting layer can be selected from, but is not limited to, one or more of GPD-1 to GPD-47 listed below.

Wherein D is deuterium.

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.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light-emitting layer can be selected from, but is not limited to, one or more of YPD-1 to YPD-11 listed below.

The organic EL light-emitting device of the present invention further includes an electron transport region between the light-emitting layer and the cathode. 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).

The electron transport region may also be formed using the compound of the present invention for a multilayer structure including at least one of an Electron Injection Layer (EIL), an Electron Transport Layer (ETL), and a Hole Blocking Layer (HBL), although the material of the electron transport region may also be combined with one or more of ET-1 to 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 material including, but not limited to, combinations of one or more of the following: LiQ, LiF, NaCl, CsF, Li₂O、Cs₂CO₃BaO, Na, Li and/or Ca.

The technical effects and advantages of the present invention are demonstrated and verified by testing practical use performance by specifically applying the compound of the present invention to an organic electroluminescent device.

Example 1

The embodiment provides a preparation method of an organic electroluminescent device, which comprises the following specific steps:

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 anode in a vacuum chamber, and vacuumizing until the pressure is less than 10^-5Pa, performing vacuum evaporation on the anode layer film by using a multi-source co-evaporation method to obtain HI-3 as a hole injection layer, wherein the evaporation rate is 0.1nm/s, and the evaporation film thickness is 10 nm;

evaporating HT-4 on the hole injection layer in vacuum to serve as a first hole transport layer of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 40 nm;

evaporating HT-14 on the first hole transport layer in vacuum to serve as a second hole transport layer of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 10 nm;

a luminescent layer of the device is vacuum evaporated on the second hole transport layer, the luminescent layer comprises a main material and a dye material, the evaporation rate of the main material BFH-4 is adjusted to be 0.1nm/s, the evaporation rate of the dye BFD-4 is set in a proportion of 5%, and the total film thickness of evaporation is 20nm by using a multi-source co-evaporation method;

vacuum evaporating ET-17 on the luminescent layer to be used as a hole blocking layer of the device, wherein the evaporation rate is 0.1nm/s, and the total film thickness is 5 nm;

evaporating an electron transport layer on the hole blocking layer by using a multi-source co-evaporation method, adjusting the evaporation rate of the compound C2 to be 0.1nm/s, setting the proportion of the evaporation rate to the evaporation rate of ET-57 to be 100%, and setting the total film thickness of evaporation to be 23 nm;

LiF with the thickness of 1nm is vacuum-evaporated on the Electron Transport Layer (ETL) to be used as an electron injection layer, and an Al layer with the thickness of 80nm is used as a cathode of the device.

Examples 2 to 6

Examples 2 to 6 were prepared as in example 1, except that the compound C2 of the electron transport layer was replaced with the compounds shown in table 1, respectively.

Comparative example 1

Comparative example 1 was prepared according to the same procedure as in example 1, except that the compound C2 of the electron transport layer was replaced with the existing compound ET-X, having the formula:

comparative example 2

Comparative example 2 was prepared as in example 1 except that compound C2 of the electron transport layer was replaced with compound ET-Y obtained in the synthesis of comparative example 1, having the formula:

the organic electroluminescent device prepared by the above process was subjected to the following performance measurement:

at the same brightness, a Photo Research PR 750 type optical radiometer, S, was usedThe driving voltage and current efficiency of the organic electroluminescent devices prepared in examples 1 to 6 and comparative examples 1 to 2 were measured using a T-86LA type luminance meter (photoelectric instrument factory, 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 1000cd/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 results of the performance tests are shown in table 1.

Table 1:

as can be seen from table 1, under the condition that other materials in the organic electroluminescent device structure are the same, the organic electroluminescent devices provided in embodiments 1 to 6 of the present invention have high current efficiency and low driving voltage, wherein the current efficiency is 8.02 to 8.65cd/a, and the driving voltage is 4.07 to 4.25V.

The compound ET-X of comparative example 1, which contains a quinolinecarbonyl-substituted imidazole group, has a driving voltage of 5.96V and a current efficiency of 4.93cd/a, and has a large difference in performance compared to the devices of examples. The reason for this speculation may be: compared with the electron transport material in the comparative example 1, on the basis of the structure that the quinoline cyano substituted imidazole parent nucleus is singly substituted by the phenyl, the quinoline ring of the parent nucleus or the phenyl is additionally connected with the aryl or heteroaryl substituent, the whole electron affinity and the plane conjugation degree of the electron transport material in the examples 1-6 are much larger than those in the comparative example 1, and therefore, the electron injection and transport capability of the electron transport material is far higher than that of the compound ET-X in the comparative example 1. In addition, the comparative example 1 compound ET-X has too small a molecular weight and relatively low Tg, which is detrimental to the thermal stability of the material.

The compound ET-Y of comparative example 2 contained a quinolinoimidazole group, the driving voltage of the device was 4.63V, the current efficiency was 7.11cd/a, and both the current efficiency and the driving voltage were inferior to those of the device of example. The reason for this speculation may be: compared with the electron transport material of comparative example 2, the electron affinity of the quinolinecarbonyl-substituted imidazole parent nucleus is stronger than that of the quinolinecarbonyl-imidazole without cyano-substitution, and the electron transport material has more appropriate molecular dipole moment with new molecules consisting of other electron-deficient groups, so that the electron transport material has stronger electron injection and migration capabilities.

Further, the inventors have found that although the organic electroluminescent device of example 6 has a lower driving voltage and a higher current efficiency than those of comparative examples 1 to 2, the above parameters are slightly inferior to those of examples 1 to 5. The reason is presumed to be: in the compounds of examples 1-5 of the present invention, quinolinecarbonyl substituted imidazole is used as a large conjugated electron-deficient group, and is further connected to an electron-deficient group such as triazine, pyrimidine or cyano substituted phenyl through an arylene group, and a plurality of electron-deficient groups can increase the electron affinity of the whole molecule, thereby facilitating the injection of electrons, and can adjust the dipole moment of the whole molecule, so that the compound has suitable electron injection and migration capabilities. The new electron transport material constructed in this way has high electron injection and migration performance, so that the device has high current efficiency and low driving voltage.

The experimental data show that the novel organic material is an organic luminescent functional material with good performance as an electron transport material of an organic electroluminescent device, and has wide application prospect.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. An organic compound having a structure represented by (1):

wherein,L₁and L₂Each independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene, or a substituted or unsubstituted C3-C30 heteroarylene;

Ar₁and Ar₂Each independently selected from substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl;

r is halogen, C1-C30 alkyl, C3-C30 cycloalkyl, C1-C30 alkoxy, amino, C6-C30 arylamine or nitro;

p and n are respectively integers of 0-6, p + n is less than or equal to 6, and when p is 0, L₁Is not a single bond;

when each of the above-mentioned substituted or unsubstituted groups has a substituent, the substituent is selected from one or a combination of plural kinds of halogen, C1-C30 alkyl, C3-C30 cycloalkyl, C2-C30 alkenyl, C2-C30 alkynyl, cyano, nitro, C1-C30 alkoxy, C1-C30 thioalkoxy, C6-C30 aryl and C3-C60 heteroaryl.

2. The organic compound according to claim 1, having a structure represented by (1-1) to (1-7):

3. the organic compound of claim 1 or 2, wherein Ar is Ar₁And Ar₂Each independently selected from the following substituted or unsubstituted structures:

4. the organic compound of claim 1 or 2, wherein Ar is Ar₁And/or Ar₂Having electron deficient groups.

5. The organic compound of claim 1 or 2, wherein L is₁And L₂Each independently selected from a single bond, phenylene, or biphenylene.

6. An organic compound according to claim 1 or 2, characterized in that n is 0.

7. The organic compound according to claim 1, wherein the organic compound has a structure represented by C1 to C94:

8. use of the organic compound according to any one of claims 1 to 7 in an organic electronic device, preferably in an organic electroluminescent device, an optical sensor, a solar cell, a lighting element, an organic thin film transistor, an organic field effect transistor, an organic thin film solar cell, an information label, an electronic artificial skin sheet, a sheet-type scanner or electronic paper.

9. Use of an organic compound according to any one of claims 1 to 7 as an electron transport material in an organic electroluminescent device.

10. An organic electroluminescent device comprising a first electrode, a second electrode and at least one organic layer between the first electrode and the second electrode, wherein the organic layer contains the organic compound according to any one of claims 1 to 7.