A compound and its application

Abstract

The present invention relates to a compound and its application. The compound has a structure shown in formula (1). The compound of the general formula has an electron-deficient large conjugated structure of 5,6-oxazoloquinoxaline as a parent core connected to an Ar group. The compound structure has a strong electron-deficient property, which is conducive to electron injection. At the same time, the electron-deficient group of the large conjugated structure gives the molecule good planar conjugation, which is conducive to improving electron mobility and making the molecule as a whole exhibit good electron injection and migration performance. Therefore, when the compound of the present invention is used in an organic electroluminescent device, especially as an electron transport layer material, it can effectively improve the electron injection and migration efficiency in the device, thereby ensuring that the device obtains the excellent effects of high luminous efficiency and low starting voltage. #imgabs0#

Description

Technical Field

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

[0002] Organic electroluminescent (OLED) devices are a type of device with a sandwich-like structure, including positive and negative electrode film layers and an organic functional material layer sandwiched between the electrode film layers. When voltage is applied to the electrodes of the OLED device, positive charges are injected from the positive electrode and negative charges are injected from the negative electrode. Under the action of the electric field, the positive and negative charges migrate in the organic layer and meet to combine and emit light. Due to the advantages of high brightness, fast response, wide viewing angle, simple process, and flexibility, OLED devices have attracted much attention in the fields of new display technologies and new lighting technologies. At present, this technology has been widely used in display panels of new lighting fixtures, smart phones, tablet computers and other products, and will further expand to the application fields of large-size display products such as televisions. It is a new display technology that is developing rapidly and has high technical requirements.

[0003] As OLEDs continue to advance in the fields of lighting and display, research on their core materials is gaining increasing attention. This is because an efficient and long-lasting OLED device is often the result of an optimized combination of device structure and various organic materials. This presents significant opportunities and challenges for chemists in designing and developing functional materials with various structures. Common functional organic materials include hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, as well as luminescent host materials and luminescent guest materials (dyes).

[0004] To produce OLED light-emitting devices with lower driving voltages, higher luminous efficiency, and longer device lifespans, and to continuously improve the performance of OLED devices, it is necessary not only to innovate in OLED device structure and manufacturing processes, but also to continuously research and innovate in the optoelectronic functional materials used in OLED devices to produce functional materials with higher performance. Based on this, the OLED materials community has been committed to developing new organic electroluminescent materials to achieve low device startup voltages, high luminous efficiency, and longer device lifespans.

[0005] In order to further meet the demand for continuously improving the optoelectronic performance of OLED devices and the demand for energy conservation in mobile electronic devices, it is necessary to continuously develop new and efficient OLED materials. Among them, the development of new electron transport materials with high electron injection ability and high mobility is of great significance. Summary of the Invention

[0006] The object of the present invention is to provide a compound having high electron injection capability and high electron mobility.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] The present invention provides a compound having a structure shown in formula (1);

[0009]

[0010] In formula (1), X is S or O;

[0011] In formula (1), the R represents a single substituent to the maximum permissible substituent, and is independently selected from one of hydrogen, deuterium, halogen, cyano, nitro, alkenyl, alkynyl, carboxyl, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl. When there are multiple R groups, adjacent R groups may be fused together.

[0012] In formula (1), L is selected from a single bond, a substituted or unsubstituted C6-C60 arylene group, or a substituted or unsubstituted C3-C60 heteroarylene group; L is preferably a single bond, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C3-C30 heteroarylene group;

[0013] In formula (1), Ar is selected from a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C3-C60 heteroaryl group; Ar is preferably a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group;

[0014] When the above-mentioned groups have substituents, the substituents are selected from one or a combination of at least two of halogen, cyano, carbonyl, C1-C12 chain alkyl, C3-C12 cycloalkyl, C2-C10 alkenyl, C1-C10 alkoxy or thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aromatic or condensed aromatic, C3-C30 monocyclic heteroaryl or condensed heteroaryl.

[0015] Furthermore, the compounds of the present invention have structures represented by the following formulas (1-1) to (1-3):

[0016]

[0017] In formula (1-1) to formula (1-3), X, R, Ar and L are defined the same as in formula (1).

[0018] Furthermore, the compound of the present invention has any one of the structures represented by the following formula (a) to formula (j):

[0019]

[0020] In formulas (a) to (j), R1-R4 are the same or different and are each independently selected from one of hydrogen, deuterium, halogen, cyano, nitro, alkenyl, alkynyl, carboxyl, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl, and two adjacent groups among R1-R4 may be fused together;

[0021] When the above-mentioned groups have substituents, the substituents are selected from one or a combination of at least two of halogen, cyano, carbonyl, C1-C12 chain alkyl, C3-C12 cycloalkyl, C2-C10 alkenyl, C1-C10 alkoxy or thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl or condensed aryl, C3-C30 monocyclic heteroaryl or condensed heteroaryl. Further preferably, in formula (1), (1-1) to (1-3), (a) to (j) of the present invention, Ar is selected from any one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, and cyano; more preferably, Ar is selected from substituted or unsubstituted C3-C30 electron-deficient heteroaryl or cyano.

[0022] In this specification, "electron-deficient heteroaryl (also referred to as electron-deficient group)" refers to a group in which the electron cloud density on the benzene ring is reduced after the group replaces the hydrogen on the benzene ring, and the Hammett value of such a group is generally greater than 0.6. The Hammett value refers to the characterization of the charge affinity of a specific group and is a measure of an electron-withdrawing group (positive Hammett value) or an electron-donating group (negative Hammett value). The Hammett equation is described in more detail in Thomas H. Lowry and Katheleen Schueller Richardson, "Mechanism and Theory In Organic Chemistry", New York, 1987, pp. 143-151, which is incorporated herein by reference. Such groups can include but are not limited to: triazinyl, pyrimidinyl, benzopyrimidinyl, benzopyridinyl, naphthyridinyl, phenanthroline, pyrazinyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, pyridazinyl, and the above-mentioned groups substituted with alkyl or aryl.

[0023] More preferably, in formula (1), formula (1-1) to formula (1-3), and formula (a) to formula (j) of the present invention, Ar is selected from cyano or any one of the following substituted or unsubstituted groups:

[0024]

[0025] Among them, the wavy line Indicates the attachment site.

[0026] When there is a substituent group in the above structural formula, the substituent group is selected from one or a combination of at least two of halogen, cyano, carbonyl, C1-C12 chain alkyl, C3-C12 cycloalkyl, C2-C10 alkenyl, C1-C10 alkoxy or thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aromatic group or condensed aromatic group, C3-C30 monocyclic heteroaryl or condensed heteroaryl group.

[0027] Still further preferably, the above R, R1-R4 are each independently selected from hydrogen, deuterium or the following substituents: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, phenyl, naphthyl, anthracenyl, benzanthryl, phenanthrenyl, triphenylenyl, pyrenyl, chrysene, peryl, fluoranthenyl, tetraphenyl, pentacene, benzopyrenyl, biphenyl, phenylene, terphenyl, tris(1,2-difluoro-1,2-difluoro-2,3-difluoro-3,4-diphenyl)imide, terphenylene ...3,4-diphenyl)imide, terphenylene, tris(1,2-difluoro-1,2-difluoro-3,4-di polyphenyl, quaternaryl, fluorenyl, spirobifluorenyl, dihydrophenanthrenyl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indenofluorenyl, trimerized indenyl, isotrimerized indenyl, spirotrimerized indenyl, spiroistrimerized indenyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, pyrrolyl, isoindolyl, carbazolyl, indenocarbazolyl, pyridinyl, quinolyl, isoquinolyl, acridinyl, phenanthridinyl, benzo-5,6-quinolyl, benzo-6,7-quinolyl, benzo-7,8-quinolyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthoimidazolyl, Phenanthroimidazolyl, pyridinoimidazolyl, pyrazinoimidazolyl, quinoxalinoimidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthraxazolyl, phenanthroxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthryl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbolinyl, phenanthroline 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, benzothiadiazolyl, or a combination of two of the above groups.

[0028] Furthermore, the compounds described in the general formula of the present invention can preferably include the specific structural compounds shown in the following C1-C91, which are only representative:

[0029]

[0030]

[0031]

[0032]

[0033]

[0034] A second object of the present invention is to provide an application of the compound described in the first object, wherein the compound is applied to organic electronic devices.

[0035] Preferably, the organic electronic device includes 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 tag, an electronic artificial skin sheet, a sheet-type scanner or electronic paper, preferably an organic electroluminescent device.

[0036] Preferably, the compound is used as an electron transport material in the organic electroluminescent device.

[0037] The compound of the present invention has a high electron affinity and thus has a strong ability to accept electrons, and is suitable for use as an electron transport material, but is not limited thereto.

[0038] A third object of the present invention is to provide an organic electroluminescent device, comprising a first electrode, a second electrode, and one or more light-emitting functional layers inserted between the first electrode and the second electrode, wherein the light-emitting functional layer contains the general formula compound of the present invention as shown in any of the above general formulas, or contains the compounds shown in the various specific structural formulas as described above.

[0039] The OLED device prepared using the compound of the present invention has a low starting voltage, high luminous efficiency and a better service life, and can meet the requirements of current panel manufacturing companies for high-performance materials.

[0040] Specifically, one embodiment of the present invention provides an organic electroluminescent device, comprising a substrate, and an anode layer, multiple light-emitting functional layers and a cathode layer 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, 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 between the hole transport layer and the electron transport layer; wherein the electron transport layer contains the general formula compound of the present invention represented by the above formula (1).

[0041] More specifically, an organic electroluminescent device is described in detail.

[0042] An OLED device includes a first electrode, a second electrode, and an organic material layer between the electrodes. The organic material layer can be divided into multiple regions. For example, the organic material layer can include a hole transport region, a light-emitting layer, and an electron transport region.

[0043] In a specific embodiment, a substrate can be used below the first electrode or above the second electrode. The substrate is made of glass or a polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, the substrate used for the display can also be provided with thin film transistors (TFTs).

[0044] The first electrode can be formed by sputtering or depositing the material used as the first electrode on the substrate. When the first electrode serves as an anode, transparent conductive oxide materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), and any combination thereof can be used. When the first electrode serves as a cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), and magnesium-silver (Mg-Ag) can be used, as well as any combination thereof.

[0045] The organic material layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, etc. The compound used as the organic material layer can be organic small molecules, organic macromolecules and polymers, and combinations thereof.

[0046] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a single-layer hole transport layer (HTL), including single-layer hole transport layers containing only one compound and single-layer hole transport layers containing multiple compounds. The hole transport region can also be a multilayer structure comprising at least one of the following: a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL); wherein the HIL is located between the anode and the HTL, and the EBL is located between the HTL and the light-emitting layer.

[0047] The material of the hole transport region can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS) and aromatic amine derivatives as shown in HT-1 to HT-51 below; or any combination thereof.

[0048]

[0049]

[0050]

[0051] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more of the compounds HT-1 to HT-51 described above, or one or more of the compounds HI-1 to HI-3 described below. Alternatively, one or more of the compounds HT-1 to HT-51 can be doped with one or more of the compounds HI-1 to HI-3 described below.

[0052]

[0053] The light-emitting layer includes a luminescent dye (i.e., a dopant) that can emit light at different wavelengths, and may also include a host material. The light-emitting layer can be a monochromatic light-emitting layer that emits a single color, such as red, green, or blue. Multiple monochromatic light-emitting layers of different colors can be arranged in a planar pattern according to a pixel pattern, or they can be stacked together to form a multi-color light-emitting layer. When light-emitting layers of different colors are stacked together, they can be separated from each other or connected to each other. The light-emitting layer can also be a single-color light-emitting layer that can simultaneously emit different colors, such as red, green, and blue.

[0054] Depending on the technology, the light-emitting layer material can be made of fluorescent electroluminescent materials, phosphorescent electroluminescent materials, thermally activated delayed fluorescence materials, and other materials. An OLED device can use a single light-emitting technology or a combination of multiple technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0055] In one aspect of the present invention, the light-emitting layer adopts fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0056]

[0057] In one aspect of the present invention, the light-emitting layer adopts fluorescent electroluminescence technology. The fluorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFD-1 to BFD-24 listed below.

[0058]

[0059]

[0060] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology, and the main material of the light-emitting layer is selected from, but not limited to, one or more combinations of PH-1 to PH-85.

[0061]

[0062]

[0063]

[0064]

[0065] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0066]

[0067]

[0068] Where D is deuterium.

[0069] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0070]

[0071] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0072]

[0073] In one aspect of the present invention, an electron blocking layer (EBL) is positioned between the hole transport layer and the light emitting layer. The EBL can be composed of, but is not limited to, one or more of the compounds HT-1 to HT-51 described above, or one or more of the compounds PH-47 to PH-77 described above; or a mixture of, but not limited to, one or more of the compounds HT-1 to HT-51 and one or more of the compounds PH-47 to PH-77.

[0074] The organic electroluminescent device of the present invention includes an electron transport region between a light-emitting layer and a cathode. The electron transport region may be a single-layer electron transport layer (ETL), including single-layer electron transport layers containing only one compound and single-layer electron transport layers containing multiple compounds. The electron transport region may also be a multilayer structure comprising at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0075] The electron transport region can also be formed by applying the compound of the present invention to a multilayer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL). Of course, the material of the electron transport region can also be a combination of one or more of ET-1 to ET-65 listed below.

[0076]

[0077]

[0078]

[0079]

[0080] In one aspect of the present invention, a hole-blocking layer (HBL) is positioned between the electron-transporting layer and the light-emitting layer. The hole-blocking layer may be composed of, but is not limited to, one or more of the compounds ET-1 to ET-65 described above, or one or more of the compounds PH-1 to PH-46, or a mixture of, but not limited to, one or more of the compounds ET-1 to ET-65 and one or more of the compounds PH-1 to PH-46.

[0081] The device may further include an electron injection layer located between the electron transport layer and the cathode. Materials for the electron injection layer include, but are not limited to, one or more combinations of the following:

[0082] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg.

[0083] The specific reasons for the excellent performance of the above-mentioned compounds of the present invention are still unclear, but it is speculated that the reasons may be as follows:

[0084] The compound provided by the present invention has a large electron-deficient conjugated structure of 5,6-oxazoloquinoxaline as the parent core and is connected to an Ar group. The compound structure has a strong electron-deficient property, which is conducive to the injection of electrons. At the same time, the electron-deficient group of the large conjugated structure gives the molecule good planar conjugation, which is conducive to improving the mobility of electrons. The above-mentioned characteristics can make the molecule as a whole exhibit good electron injection and migration performance. Therefore, when the compound of the present invention is used as an organic electroluminescent device, especially as an electron transport material, it can effectively improve the electron injection and migration efficiency in the device, thereby ensuring that the device obtains the excellent effect of high luminous efficiency and low starting voltage.

[0085] In addition, the preparation process of the compound of the present invention is simple and easy, the raw materials are readily available, and it is suitable for mass production and expansion. DETAILED DESCRIPTION

[0086] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0087] The synthetic route of the compound shown in the general formula of the present invention is as follows:

[0088]

[0089] (1) Preparation of compound (a)

[0090] In the first step, the substituted 5-bromo-6-aminoquinoxaline and the acyl chloride are refluxed at 120°C in a toluene solution containing triethylamine to obtain the amide intermediate M1a. In the second step, the intermediate M1a is coupled and cyclized under the catalysis of cuprous iodide to obtain the target 5,6-oxazoloquinoxaline compound (a). Here, R1, R2, R3, R4, L, and Ar all have the same meanings as in general formula (1), Et3N is triethylamine, and DMSO is dimethyl sulfoxide.

[0091] (2) Preparation of compound (b)

[0092] In the first step, the substituted 7-chloro-5-bromo-6-aminoquinoxaline and the acid chloride are refluxed at 120°C in a toluene solution containing triethylamine to obtain the amide intermediate M1b. In the second step, the intermediate M1b is coupled and ring-closed under the catalysis of cuprous iodide to obtain the 5,6-oxazoloquinoxaline intermediate M2b. In the third step, the intermediate M2b is Suzuki coupled with an arylboronic acid to obtain the target compound (b). Here, R1, R2, R3, R4, L, and Ar all have the same meanings as in general formula (1), Et3N is triethylamine, and DMSO is dimethyl sulfoxide.

[0093] (3) Preparation of compound (d)

[0094] In the first step, the substituted 2-chloro-5-bromo-6-aminoquinoxaline and the acid chloride are refluxed at 120°C in a toluene solution containing triethylamine to obtain the amide intermediate M1d. In the second step, the intermediate M1d is coupled and cyclized under the catalysis of cuprous iodide to obtain the 5,6-oxazoloquinoxaline intermediate M2d. In the third step, the intermediate M2d is Suzuki coupled with an arylboronic acid to obtain the target compound (d). Here, R1, R2, R3, R4, L, and Ar all have the same meanings as in general formula (1), Et3N is triethylamine, and DMSO is dimethyl sulfoxide.

[0095] The following synthesis examples provide synthesis methods for specific compounds. Chemicals used in these methods, such as ethanol, ethyl acetate, triethylamine, sodium sulfate, toluene, tetrahydrofuran, dichloromethane, 1,4-dioxane, dimethyl sulfoxide, potassium carbonate, potassium acetate, and cuprous iodide, were purchased from Shanghai Titan Technology Co., Ltd. and Xilong Chemical Co., Ltd. The mass spectrometer used to determine the properties of the following compounds was a ZAB-HS mass spectrometer (manufactured by Micromass, UK).

[0096] Synthesis example 1:

[0097] Synthesis of compound C1

[0098]

[0099] (1) Preparation of compound 1-1

[0100] 2-Bromo-3-amino-5-chloroquinoxaline (257 g, 1.0 mol) and triethylamine (202 g, 2.0 mol) were added to a 2-L flask containing 1 L of toluene. 4-Chlorobenzoyl chloride (174 g, 1.0 mol) was slowly added dropwise with stirring at room temperature. After the addition, the reaction was stirred and refluxed at 120°C for 8 hours. TLC monitoring showed the reaction was complete. After cooling the reaction solution to room temperature, it was slowly poured into 2 L of water, resulting in the precipitation of a large amount of solid. After filtration, the solid was separated and purified by column chromatography to obtain compound 1-1 (332 g, 84% yield).

[0101] (2) Preparation of Compound 1-2

[0102] Compound 1-1 (330 g, 835 mmol), anhydrous potassium carbonate (115 g, 835 mmol), and 1 L of dimethyl sulfoxide were added to a 2 L flask. After nitrogen displacement, cuprous iodide (3.16 g, 16.7 mmol) was added. The nitrogen was displaced four times, and the mixture was stirred and refluxed at 110°C for 10 hours. A large amount of solid precipitated, and the reaction endpoint was monitored by TLC. After the reaction was cooled to room temperature, the reaction solution was filtered, and the solid was rinsed three times with water and ethanol, respectively. The solid was dried, and the filtrate was washed with saturated sodium bicarbonate solution, extracted with dichloromethane, and the organic phases were combined. The solid and organic phases were separated and purified by column chromatography to obtain compound 1-2 (247 g, yield 94%).

[0103] (3) Preparation of Compound 1-3

[0104] Compound 1-2 (245 g, 778 mmol), phenylboronic acid (104 g, 856 mmol), and potassium acetate (215 g, 1556 mmol) were added to a 5 L flask containing 2 L of tetrahydrofuran and 400 mL of water. [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (5.48 g, 7.8 mmol) was added with nitrogen replacement under stirring at room temperature. After the addition was complete, the nitrogen atmosphere was replaced four times. The mixture was stirred and refluxed for 6 hours, resulting in the precipitation of a large amount of solid. The reaction endpoint was monitored by TLC. The tetrahydrofuran and water were removed by rotary evaporation, and the solid was washed with water and ethanol, respectively. After drying, it was purified by column chromatography to obtain compound 1-3 (244 g, 88% yield).

[0105] (4) Preparation of Compound 1-4

[0106] Compound 1-3 (242 g, 678 mmol), pinacol diboronate (258 g, 1017 mmol), and potassium acetate (187 g, 1356 mmol) were added to a 5-L flask containing 3 L of 1,4-dioxane. With stirring at room temperature, the atmosphere was replaced with nitrogen, and palladium acetate (3.1 g, 13.6 mmol) and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (11.2 g, 27.2 mmol) were added. After the addition, the nitrogen atmosphere was replaced four times, and the mixture was stirred and refluxed for 4 hours. The reaction endpoint was monitored by TLC. The 1,4-dioxane was removed by rotary evaporation, and the mixture was separated by adding water and dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to obtain compound 1-4 (253 g, 83% yield).

[0107] (5) Preparation of Compound C1

[0108] Compound 1-4 (10 g, 22.3 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (5.9 g, 22.3 mmol), potassium carbonate (6.2 g, 44.6 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (146 mg, 0.2 mmol) were added to a flask containing 100 mL of tetrahydrofuran and 25 mL of water. The atmosphere was replaced with nitrogen and heated under reflux for 4 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to obtain compound C1 (10.5 g, 85% yield). Calculated molecular weight: 554.19, measured C / Z: 554.2.

[0109] Synthesis example 2:

[0110] Synthesis of compound C3

[0111]

[0112] (1) Preparation of compound 2-1

[0113] 50 g (256 mmol, 1.0 eq) of 2,4-dichloroquinazoline was added to a 1 L single-necked flask, followed by 400 mL of dichloromethane. The mixture was cooled to 0°C in an ice bath, and 64 g (632 mmol, 3.0 eq) of triethylamine was added. The reaction mixture was stirred until the solution became clear. 18.6 g (316 mmol, 1.5 eq) of hydrazine hydrate was then added dropwise in an ice bath. During the reaction, solids gradually precipitated. The mixture was stirred for 3 hours. TLC monitoring indicated the disappearance of the starting material. 4.0 L of water was added, and stirring continued for 1 hour. The mixture was filtered and dried to afford compound 2-1 (41.2 g, yield: 83%).

[0114] (2) Preparation of Compound 2-2

[0115] 40g of compound 2-1 (206mmol, 1.0eq), 19.8g (227mmol, 1.1eq) of benzaldehyde, and 500mL of ethanol were added to a 1.0L single-necked flask and stirred until the solution was clear and then continued to stir for 30 minutes. TLC monitoring showed that the starting material disappeared. 73g (227mmol, 1.1eq) of iodophenyl diacetic acid was added in batches (the temperature was controlled below 20°C during the addition). After the addition was completed, the mixture was stirred overnight. Solids gradually precipitated. After TLC monitoring, the reaction was completed, and the filter cake was rinsed with ethanol until the filtrate was a colorless clear liquid. The filtrate was rinsed with petroleum ether (PE) 2 to 3 times and dried to obtain compound 2-2 (46g, yield: 81%).

[0116] (3) Preparation of Compound C3

[0117] Compound 2-2 (10 g, 35.7 mmol), compound 1-4 (16 g, 35.7 mmol), potassium carbonate (9.9 g, 71.4 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (263 mg, 0.36 mmol) were added to a flask containing 160 mL of tetrahydrofuran and 40 mL of water. The atmosphere was replaced with nitrogen and heated under reflux for 4 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to obtain compound C3 (17.6 g, 87% yield). Calculated molecular weight: 567.18, measured C / Z: 567.2.

[0118] Synthesis example 3:

[0119] Synthesis of compound C17

[0120]

[0121] Compound 1-4 (10 g, 22.3 mmol), 9-bromo-10-(1-naphthyl)anthracene (8.5 g, 22.3 mmol), potassium carbonate (6.2 g, 44.6 mmol), and tetrakistriphenylphosphine palladium (0.25 g, 0.22 mmol) were added to a flask containing 100 mL of toluene, 20 mL of ethanol, and 20 mL of water. The atmosphere was replaced with nitrogen and the mixture was heated under reflux for 6 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to obtain compound C17 (11.3 g, 81% yield). Calculated molecular weight: 625.22, measured C / Z: 625.2.

[0122] Synthesis example 4:

[0123] Synthesis of compound C22

[0124]

[0125] (1) Preparation of compound 4-1

[0126] Compound 2,4-dibromo-3-amino-5-chloroquinoxaline (33.5 g, 100 mmol) and triethylamine (20.2 g, 200 mmol) were added to a 1-L flask containing 200 mL of toluene. 4-Chlorobenzoyl chloride (17.4 g, 100 mmol) was slowly added dropwise with stirring at room temperature. After the addition, the reaction was stirred and refluxed at 120°C for 6 hours. TLC monitoring showed that the reaction was complete. After cooling the reaction solution to room temperature, it was slowly poured into 1 L of water, whereupon a large amount of solid precipitated. After filtration, the solid was separated and purified by column chromatography to obtain compound 4-1 (40.7 g, 86% yield).

[0127] (2) Preparation of compound 4-2

[0128] Compound 4-1 (40 g, 84.5 mmol), anhydrous potassium carbonate (12 g, 84.5 mmol), and 200 mL of dimethyl sulfoxide were added to a 1 L flask. After nitrogen displacement, cuprous iodide (0.32 g, 1.7 mmol) was added. The nitrogen was displaced four times, and the mixture was stirred and refluxed at 110°C for 8 hours. A large amount of solid precipitated, and the reaction endpoint was monitored by TLC. After the reaction was cooled to room temperature, the reaction solution was filtered, and the solid was rinsed three times with water and ethanol, respectively. The solid was dried, and the filtrate was washed with saturated sodium bicarbonate solution. The filtrate was extracted with dichloromethane, and the organic phases were combined. The solid and organic phases were separated and purified by column chromatography to obtain compound 4-2 (25.9 g, 78% yield).

[0129] (3) Preparation of compound 4-3

[0130] Compound 4-2 (25 g, 63.6 mmol), phenylboronic acid (8.5 g, 70 mmol), potassium carbonate (17.6 g, 127.2 mmol), and tetrakistriphenylphosphine palladium (0.74 g, 0.64 mmol) were added to a flask containing 200 mL of toluene, 40 mL of ethanol, and 40 mL of water. The atmosphere was replaced with nitrogen and the mixture was heated under reflux for 4 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, rinsed with water and ethanol, dried, and purified by column chromatography to obtain compound 4-3 (21.2 g, 80% yield).

[0131] (4) Preparation of Compound 4-4

[0132] Compound 4-3 (21 g, 50.5 mmol), phenylboronic acid (6.7 g, 55.5 mmol), potassium carbonate (13.9 g, 101 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (366 mg, 0.5 mmol) were added to a 1L flask containing 200 mL of tetrahydrofuran and 50 mL of water. The atmosphere was replaced with nitrogen and heated under reflux for 5 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, rinsed with water and ethanol, dried, and purified by column chromatography to obtain compound 4-4 (19.4 g, 84% yield).

[0133] (5) Preparation of Compound 4-5

[0134] Compound 4-4 (19 g, 41.5 mmol), pinacol diboronate (15.8 g, 62.3 mmol), and potassium acetate (8.1 g, 83 mmol) were added to a 1-L flask containing 300 mL of 1,4-dioxane. With stirring at room temperature, the atmosphere was replaced with nitrogen, and palladium acetate (187 mg, 0.83 mmol) and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (0.68 g, 1.66 mmol) were added. After the addition, the nitrogen atmosphere was replaced four times, and the mixture was stirred and refluxed for 12 hours. The reaction endpoint was monitored by TLC. The 1,4-dioxane was removed by rotary evaporation, and the mixture was separated by adding water and dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography to obtain compound 4-5 (17.8 g, 78% yield).

[0135] (6) Preparation of Compound C22

[0136] Compound 4-5 (17 g, 31 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (8.2 g, 31 mmol), potassium carbonate (8.6 g, 62 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (219 mg, 0.3 mmol) were added to a flask containing 200 mL of tetrahydrofuran and 50 mL of water. The atmosphere was replaced with nitrogen and the mixture was heated under reflux for 6 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to obtain compound C22 (15.6 g, 77% yield). Calculated molecular weight: 655.21, measured C / Z: 655.2.

[0137] Synthesis example 5:

[0138] Synthesis of compound C30

[0139]

[0140] Compound 1-4 (10 g, 22.3 mmol), 2-bromo-9,9-spirobifluorene (8.8 g, 22.3 mmol), potassium carbonate (6.2 g, 44.6 mmol), and tetrakistriphenylphosphine palladium (0.25 g, 0.22 mmol) were added to a flask containing 100 mL of toluene, 20 mL of ethanol, and 20 mL of water. The atmosphere was replaced with nitrogen and heated under reflux for 6 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to obtain compound C30 (11.9 g, 84% yield). Calculated molecular weight: 637.22, measured C / Z: 637.2.

[0141] Synthesis example 6:

[0142] Synthesis of compound C41

[0143]

[0144] (1) Preparation of compound 6-1

[0145] 2-Bromo-3-amino-5-chloroquinoxaline (25.7 g, 100 mmol) and triethylamine (20.2 g, 200 mmol) were added to a 1-L flask containing 200 mL of toluene. Benzoyl chloride (14 g, 100 mmol) was slowly added dropwise with stirring at room temperature. After the addition, the reaction was stirred and refluxed at 120°C for 4 hours. TLC monitoring showed that the reaction was complete. After cooling the reaction solution to room temperature, it was slowly poured into 1 L of water, whereupon a large amount of solid precipitated. After filtration, the solid was separated and purified by column chromatography to obtain compound 6-1 (31.4 g, 87% yield).

[0146] (2) Preparation of compound 6-2

[0147] Compound 6-1 (31 g, 86 mmol), anhydrous potassium carbonate (23.7 g, 172 mmol), and 200 mL of dimethyl sulfoxide were added to a 1 L flask. After nitrogen displacement, cuprous iodide (0.32 g, 1.7 mmol) was added. The nitrogen was displaced four times, and the mixture was stirred and refluxed at 110°C for 6 hours. A large amount of solid precipitated, and the reaction endpoint was monitored by TLC. After the reaction was cooled to room temperature, the reaction solution was filtered, and the solid was rinsed three times with water and ethanol, respectively. The solid was dried, and the filtrate was washed with saturated sodium bicarbonate solution and extracted with dichloromethane. The organic phases were combined, and the solid and organic phases were separated and purified by column chromatography to obtain compound 6-2 (22.2 g, 92% yield).

[0148] (3) Preparation of compound C41

[0149] Compound 6-2 (10 g, 35.6 mmol), 2,4-diphenyl-6-(4-pinacol boroyl)phenyl-1,3,5-triazine (17 g, 39.1 mmol), potassium carbonate (9.8 g, 71.2 mmol), trisdibenzylideneacetone dipalladium (0.65 g, 0.71 mmol), and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (0.57 g, 1.4 mmol) were added to a 1-L flask containing 200 mL of 1,4-dioxane and 20 mL of water. The atmosphere was replaced with nitrogen and heated under reflux for 4 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to obtain compound C41 (15.2 g, 77% yield). Calculated molecular weight: 554.19, measured C / Z: 554.2.

[0150] Synthesis example 7:

[0151] Synthesis of compound C59

[0152]

[0153] (1) Preparation of compound 7-1

[0154] Compound 6-2 (10 g, 35.6 mmol), 3-chlorophenylboronic acid (6.1 g, 39.2 mmol), potassium carbonate (9.8 g, 71.2 mmol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride (263 mg, 0.36 mmol) were added to a flask containing 100 mL of tetrahydrofuran and 25 mL of water. The atmosphere was replaced with nitrogen and heated under reflux for 4 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, rinsed with water and ethanol, dried, and purified by column chromatography to obtain compound 7-1 (10.5 g, 83% yield).

[0155] (2) Preparation of compound C59

[0156] Compound 7-1 (10 g, 28 mmol), 2,4-diphenyl-6-(3-pinacol boroyl)phenyl-1,3,5-triazine (12.2 g, 28 mmol), potassium carbonate (7.7 g, 56 mmol), trisdibenzylideneacetone dipalladium (0.51 g, 0.56 mmol), and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (0.46 g, 1.12 mmol) were added to a 1-L flask containing 200 mL of 1,4-dioxane and 20 mL of water. The atmosphere was replaced with nitrogen and heated under reflux for 6 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to obtain compound C59 (13.1 g, 74% yield). Calculated molecular weight: 630.22, measured C / Z: 630.2.

[0157] Comparative Synthesis Example 1

[0158] Synthesis of comparative compound D1:

[0159]

[0160] 2-Bromo-1H-imidazole-[4,5-f]quinoxaline (10 g, 40.3 mmol), N-phenylcarbazole-3-boronic acid (11.6 g, 40.3 mmol), potassium carbonate (11.1 g, 80.6 mmol), and tetrakistriphenylphosphine palladium (0.46 g, 0.4 mmol) were added to a flask containing 100 mL of toluene, 20 mL of ethanol, and 20 mL of water. The atmosphere was replaced with nitrogen and heated under reflux for 6 hours. TLC indicated the reaction was complete. The precipitated solid was filtered, washed with water and ethanol, dried, and purified by column chromatography to obtain compound D1 (14.6 g, 88% yield). Calculated molecular weight: 411.15, measured C / Z: 411.2.

[0161] Device Example 1

[0162] This embodiment provides a method for preparing an organic electroluminescent device, which is as follows:

[0163] Glass plates coated with an ITO transparent conductive layer were ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0164] Place the glass substrate with the anode in a vacuum chamber and evacuate it to a pressure less than 10 -5 Pa, vacuum evaporating HI-3 on the above anode layer as a hole injection layer, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 10nm;

[0165] HT-4 was vacuum evaporated on the hole injection layer as the first hole transport layer of the device at a deposition rate of 0.1 nm / s and a total film thickness of 40 nm.

[0166] HT-14 was vacuum evaporated on the first hole transport layer as the second hole transport layer of the device at a deposition rate of 0.1 nm / s and a total film thickness of 10 nm.

[0167] The light-emitting layer of the device is vacuum-deposited on the second hole transport layer. The light-emitting layer includes a host material and a dye material. Using a multi-source co-evaporation method, the evaporation rate of the host material BFH-4 is adjusted to 0.1nm / s, and the evaporation rate of the dye BFD-6 is set at 5% ratio. The total film thickness of the evaporation is 20nm.

[0168] ET-17 was vacuum-deposited on the light-emitting layer as the hole-blocking layer of the device at a deposition rate of 0.1 nm / s and a total deposition thickness of 5 nm.

[0169] Compound C1 of the present invention and ET-57 were evaporated on the hole blocking layer by a multi-source co-evaporation method as an electron transport layer. The evaporation rate of compound C1 was adjusted to 0.1 nm / s, and the ratio of the evaporation rate of ET-57 to the evaporation rate of ET-57 was set to 100% (the ratio of the evaporation rates of C1 and ET-57 was 1:1). The total film thickness of the evaporation was 23 nm.

[0170] LiF with a thickness of 1 nm was vacuum evaporated on the electron transport layer (ETL) as the electron injection layer, and an Al layer with a thickness of 80 nm was used as the cathode of the device.

[0171] The only difference between device examples 2-7 and device example 1 is that the compound C1 of the present invention used in the electron transport layer is replaced by other compounds of the present invention, as shown in Table 1 for details.

[0172] Device Comparative Example 1

[0173] The difference from device example 1 is that the compound C1 of the present invention used in the electron transport layer is replaced by the prior art compound D1.

[0174] Performance testing:

[0175] At the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in the examples and comparative examples were measured using a PR 750 photoradiometer from Photo Research, an ST-86LA luminance meter (from the Optoelectronic Instrument Factory of Beijing Normal University), and a Keithley 4200 test system. Specifically, the voltage was increased at a rate of 0.1 V per second, and the driving voltage and current efficiency of the organic electroluminescent devices were measured when the brightness reached 1000 cd / m 2 The voltage at this time is the driving voltage, and the current density at this time is measured at the same time; the ratio of brightness to current density is the current efficiency;

[0176] The performance test results are shown in Table 1.

[0177] Table 1:

[0178]

[0179] As can be seen from Table 1, when the material schemes and preparation processes of other functional layers in the organic electroluminescent device structure are exactly the same, the organic electroluminescent devices provided by device Examples 1-7 of the present invention have higher current efficiency and lower driving voltage than the comparative example. In device Examples 1-7, the current efficiency of the device is 6.84-7.33 cd / A, and the driving voltage of the device is 3.76-4.21 V.

[0180] The parent core of the compound of the present invention is an electron-deficient large conjugated structure of 5,6-oxazoloquinoxaline. Ar is connected to the parent core, so that the entire compound has high electron injection and migration performance, thereby making the device have high current efficiency and low driving voltage. However, replacing the parent core with other structures (such as the comparative compound D1 in the prior art) cannot achieve the technical effects of the present invention.

[0181] The above experimental data show that the novel organic material of the present invention is an organic light-emitting functional material with good performance as an electron transport material for organic electroluminescent devices and has broad application prospects.

[0182] While the present invention is described through the above-described embodiments, the present invention is not limited to the above-described detailed methods, nor does it necessarily rely on the above-described detailed methods for implementation. Those skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for raw materials in the products of the present invention, addition of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A compound having the structure shown in formula (1); In formula (1), X is O; In formula (1), R represents a single substituent to the maximum permissible substituent, and each R is independently selected from hydrogen, phenyl, biphenyl, cyano-substituted phenyl, and cyano-substituted biphenyl; In formula (1), L is selected from a single bond, a C6-C30 arylene group; In formula (1), Ar is selected from any one of the following substituted or unsubstituted groups: in, Wavy lines Represents a connection site; when the above-mentioned group Ar has a substituent, the substituent is selected from a C6 to C30 monocyclic aromatic group.

2. The compound according to claim 1, wherein the compound has any one of the structures represented by the following formula (1-1) to formula (1-3): In formula (1-1) to formula (1-3), X, R, Ar and L are defined the same as in formula (1).

3. The compound according to claim 1, wherein the compound has any one of the structures represented by the following formula (a) to formula (e): In formula (a) to formula (e), R1 to R4 are the same or different and are independently selected from hydrogen, phenyl, and phenyl substituted with cyano.

4. A compound having the structure shown below:

5. Use of the compound according to any one of claims 1 to 4 as an electron transport material in an organic electroluminescent device.

6. An organic electroluminescent device comprising a first electrode, a second electrode, and one or more light-emitting functional layers interposed between the first and second electrodes, wherein the light-emitting functional layers comprise a hole transport region, a light-emitting layer, and an electron transport region, wherein the hole transport region is formed on an anode layer, the cathode layer is formed on the electron transport region, and the light-emitting layer is located between the hole transport region and the electron transport region; wherein: The electron transport region includes an electron transport layer, and the electron transport layer contains the compound according to any one of claims 1 to 4.

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