TWI706944B - Pyridine-substituted diphenylpyrimidines compounds and organic electroluminescent devices using the same - Google Patents

Abstract

The present invention provides pyridine-substituted diphenylpyrimidines compounds of formula (I) and an organic electroluminescent device using the same:

wherein X₁, A₁ and n are as defined in the description.

Description

Diphenylpyrimidine compound substituted by pyridine and its organic electroluminescent element

The present invention relates to a material for an organic electroluminescent device and an organic electroluminescent device using the material, and more particularly to a material that can extend the life of the organic electroluminescent device and an organic electroluminescent device using the material.

Organic electroluminescent element (OLED) is regarded as the most potential flat display technology because of its light, thin, wide viewing angle, high contrast, low power consumption, high response speed, and flexibility in full-color painting. , In order to meet the application of the organic electroluminescence element, special emphasis is placed on the development of its novel organic materials.

A typical OLED is a multilayer thin film structure formed by sequentially depositing an anode, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode by a vacuum deposition method or a coating method. When a current is applied, the anode injects holes and the cathode injects electrons into the one or more organic layers, and the injected holes and electrons migrate to opposite charged electrodes. When electrons and holes are confined to the same molecule, an "exciton" is formed. This exciton system has a localized electron-hole pair with an excited energy state. The exciton relaxes and emits through the luminescence mechanism. Light.

The multi-layer thin film structure of OLED is to provide the device with good charge transport ability and luminous efficiency. The key considerations include the stability of the interface between the electrodes and the organic layer and the matching of commensurate organic materials. If commensurate hole transport and electrons are used In the transport layer, holes and electrons can be effectively transported to the light-emitting layer, so that the density of the electrons and holes in the light-emitting layer is balanced and the luminous efficiency is increased. In addition, it has been published in the literature that the method of blending another guest material with the host material can also improve the performance of the device and adjust the chromaticity. Several OLED materials and device configurations are described in U.S. Patent Nos. 4,769,292, 5,844,363, 5,707,745, 6,596,415, and 6,465,115, which are incorporated herein by reference in their entirety. Yulei Optoelectronics Technology has applied for the Republic of China patent number I582081 in 2016 and was certified in 2017. The electronic transmission material introduced in this patent has certain novelty and effects, and the effect of the present invention is better than that of the previous patent. .

However, it is still difficult to find organic materials that meet the needs of all practical display applications, especially for automotive displays. The organic materials used in organic electroluminescent devices need to have good thermal stability to maintain their luminous color. Requirements in terms of brightness, luminous efficiency and service life.

Therefore, there is an urgent need for an organic material with good heat resistance, which can significantly improve the life of the organic electroluminescent device to meet the needs of diversified applications.

The purpose of the present invention is to provide a material for organic electroluminescent devices that has a long life and good heat resistance.

The present invention provides a pyridine substituted diphenylpyrimidine compound having the structure of formula (I):

Wherein, X ₁ represents a substituted or unsubstituted C _6-30 aryl group, a substituted or unsubstituted C _5-30 containing at least one heteroatom selected from the group consisting of N, O, and S Heteroaryl; A ₁ represents a substituted or unsubstituted C _6-30 fused polycyclic aromatic hydrocarbon group (fused polycyclic aromatic), substituted or unsubstituted containing selected from the group consisting of N, O, and S at least one of the C _5-30 hetero atoms of a condensed polycyclic aromatic hydrocarbon group; and n represents an integer of 1 or 2, and when n represents 2, a ₁ are each the same or different.

The present invention further provides an organic electroluminescent device, comprising: a cathode; an anode; and an organic layer, which is interposed between the cathode and the anode, and the organic layer includes the pyridine substituted with the structure of formula (I) of the present invention Diphenylpyrimidine compounds.

The pyridine-substituted diphenylpyrimidine compound with the structure of formula (I) provided by the present invention can improve the life of organic electroluminescent devices, increase carrier mobility, increase the probability of excitons in the light-emitting layer and provide good The benefits of heat resistance.

100, 200, 300‧‧‧Organic electroluminescence element

110、210、310‧‧‧Substrate

120、220、320‧‧‧Anode

130, 230, 330‧‧‧hole injection layer

140, 240, 340‧‧‧hole transmission layer

150, 250, 350‧‧‧Emitting layer

160, 260, 360‧‧‧ electron transport layer

170, 270, 370‧‧‧Electron injection layer

180、280、380‧‧‧Cathode

245、355‧‧‧ exciton blocking layer

The embodiment of the present invention will be explained through exemplary reference to the drawings: Figure 1 is a schematic cross-sectional view of one embodiment of the organic electroluminescent device of the present invention; Figure 2 is another embodiment of the organic electroluminescent device of the present invention Fig. 3 is a schematic cross-sectional view of another embodiment of the organic electroluminescent device of the present invention.

The following is a specific embodiment to illustrate the implementation of the present invention. Those skilled in the art can easily understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied by other different embodiments, and various details in this specification can also be based on different viewpoints and applications, without departing from the spirit of the present invention. In addition, all ranges and values herein are inclusive and combinable. Any value or point falling within the range described herein, for example, any integer can be used as the minimum or maximum value to derive the lower range and so on.

According to the present invention, a pyridine substituted diphenylpyrimidine compound with the structure of formula (1):

Wherein, X ₁ represents a substituted or unsubstituted C _6-30 aryl group, a substituted or unsubstituted C _5-30 containing at least one heteroatom selected from the group consisting of N, O, and S Heteroaryl; A ₁ represents a substituted or unsubstituted C _6-30 fused polycyclic aromatic hydrocarbon group (fused polycyclic aromatic), substituted or unsubstituted containing selected from the group consisting of N, O, and S at least one of the C _5-30 hetero atoms of a condensed polycyclic aromatic hydrocarbon group; and n represents an integer of 1 or 2, and when n represents 2, a ₁ are each the same or different.

In a specific embodiment, the above-mentioned pyridine-substituted diphenylpyrimidine compound having the structure of formula (I) is represented by the structure of formula (I-1) or formula (I-2):

Wherein, X ₁ represents a substituted or unsubstituted C _6-30 aryl group, a substituted or unsubstituted C _5-30 containing at least one heteroatom selected from the group consisting of N, O, and S Heteroaryl; A ₁ represents a substituted or unsubstituted C _6-30 fused polycyclic aromatic hydrocarbon group, substituted or unsubstituted containing at least one hetero group selected from the group consisting of N, O, and S Atom C _5-30 condensed polycyclic aromatic hydrocarbon group; and n represents an integer of 1 or 2, and when n represents 2, A ₁ are each the same or different.

The A ₁ of the pyridine-substituted diphenylpyrimidine compound having the structure of formula (I) is a substituted or unsubstituted C _6-30 fused polycyclic aromatic hydrocarbon group, and the substituted or unsubstituted containing is selected from The C _5-30 condensed polycyclic aromatic hydrocarbon group of at least one heteroatom in the group consisting of N, O, and S is due to the more planar structure, which can help molecular stacking and increase its carrier transmission effect However, the carbon number of the selected group should not be too much to avoid unnecessary crystal formation.

The X ₁ of the pyridine-substituted diphenylpyrimidine compound having the structure of formula (I) is a substituted or unsubstituted C _6-30 aryl group, a substituted or unsubstituted containing selected from N, O, The C _5-30 heteroaryl group of at least one heteroatom in the group consisting of S and S has the effect of inhibiting molecular crystallization. In a specific embodiment, X ₁ is a monovalent group and is selected from substituted or unsubstituted pyridyl, unsubstituted naphthyl, unsubstituted quinolinyl or unsubstituted phenyl .

In another specific embodiment, the above-mentioned pyridine-substituted diphenylpyrimidine compound with the structure of formula (I) has the structure of formula (I-3), formula (I-4) or formula (I-5) Means:

Wherein, A ₁ represents a substituted or unsubstituted C _6-30 fused polycyclic aromatic hydrocarbon group, a substituted or unsubstituted containing at least one heteroatom selected from the group consisting of N, O, and S C _5-30 condensed polycyclic aromatic hydrocarbon group; and n represents an integer of 1 or 2, and when n represents 2, each A ₁ is the same or different.

In a specific implementation aspect, A ₁ is selected from one of the following structures:

Wherein, L is selected from one of the group consisting of C, O, S and N; and one of R ₁ to R ₄ is a single bond and is connected to the compound of formula (I), and the remaining R ₁ to R ₄ each independently represents hydrogen, substituted or unsubstituted C _6-30 aryl, substituted or unsubstituted C _5-30 heteroaryl.

In a specific embodiment, when n is 1, the compound of formula (I) is represented by formula (I-6) or formula (I-7):

In a specific embodiment, when n is 2, the compound of formula (I) is represented by formula (I-8):

In another embodiment, when n is 2, the A ₁ has the same structure.

In the text, the expression "substituted" in "substituted or unsubstituted" means that a hydrogen atom in a certain functional group is replaced by another atom or group (ie, a substituent). The substituents are each independently selected from at least one of the following groups: deuterium, halogen, C _1-30 alkyl, C _1-30 alkoxy, C _6-30 aryl, C _{5- 30} heteroaryl, C _5-30 heteroaryl substituted by C _6-30 aryl, benzimidazolyl, C _3-30 cycloalkyl, C _5-7 heterocycloalkyl, tri-C _1-30 alkane Base silyl group, tri-C _1-3o arylsilyl group, two C _1-30 alkyl group, C _6-30 arylsilyl group, C _1-30 alkyl group, two C _6-30 arylsilyl group, C _2-30 Alkenyl, C _2-30 alkynyl, cyano, two C _1-30 alkylamino, two C _6-30 aryl boron, two C _1-30 alkyl boron, C _1-30 alkyl, C _6-30 aryl, C _1-30 alkyl, C _1-30 alkyl, C _6-30 aryl, carboxyl, nitro and hydroxyl.

In the text, "aryl" means an aryl group or (extended) aryl group. The aryl group refers to a monocyclic ring or a condensed polycyclic ring derived from an aromatic hydrocarbon, and includes phenyl, biphenyl, triphenyl, Naphthyl, binaphthyl, phenyl naphthyl, naphthyl phenyl, stilbene, phenyl stilbene, benzo stilbene, dibenzo stilbene, phenanthryl, phenylphenanthryl, anthracenyl, indenyl, Triphenylene, pyrenyl, fused tetraphenyl, perylenyl, quinyl, naphthonaphthyl, allenyl and so on.

唑基、

唑基、

二唑基、三

基、四

基、三唑基、四唑基、呋呫基、吡啶基、吡

基、嘧啶基、嗒

基等，或為與至少一個苯環縮合的稠合環，如苯并呋喃基、苯并噻吩基、異苯并呋喃基、二苯并呋喃基、二苯并噻吩基、苯并咪唑基、苯并噻唑基、苯并異噻唑基、苯并 異

唑基、喹啉基、異喹啉基、噌啉基、喹唑啉基、喹

啉基、咔唑基、啡

唑基、啡啶基、苯并二

呃基、二氫吖啶基等。 In the text, "heteroaryl" means heteroaryl or (extended) heteroaryl, and the heteroaryl refers to a ring main chain atom containing at least one heteroatom selected from the group consisting of N, O, and S The aryl group can be a single ring system ring, such as furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, iso

Azole,

Azole,

Diazolyl, three

Base, four

Group, triazolyl, tetrazolyl, furyl, pyridyl, pyridine

Base, pyrimidinyl, ta

Group, etc., or a fused ring condensed with at least one benzene ring, such as benzofuranyl, benzothienyl, isobenzofuranyl, dibenzofuranyl, dibenzothienyl, benzimidazolyl, Benzothiazolyl, benzisothiazolyl, benziso

Azolyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoline

Linyl, carbazolyl, phenanthrene

Azolyl, phenanthridinyl, benzodi

Er group, dihydroacridinyl group, etc.

In a specific embodiment, the preferred embodiment of the aforementioned pyridine-substituted diphenylpyrimidine compound having the structure of formula (I) is selected from Table 1, but is not limited thereto.

In another embodiment, the above-mentioned pyridine-substituted diphenylpyrimidine compound is selected from one of the following compounds:

Since the pyridine-substituted diphenylpyrimidine compound of the present invention has a glass transition temperature between 99 and 135°C, it can withstand a long-term high-temperature environment inside a car, so it is suitable for organic electroluminescent elements of car displays.

The present invention further provides an organic electroluminescent device, comprising: a cathode; an anode; and an organic layer, which is interposed between the cathode and the anode, and the organic layer includes the pyridine substituted diphenylpyrimidine compound of the present invention.

The organic layer of the organic electroluminescent device of the present invention can be an electron transport layer, an electron injection layer, a light-emitting layer, a hole blocking layer or an electron blocking layer, and in addition to the organic layer, the organic electroluminescent device can be Comprising at least one layer selected from the group consisting of an electron transport layer, an electron injection layer, a light-emitting layer, a hole blocking layer, and an electron blocking layer different from the organic layer, wherein the light-emitting layer contains fluorescent or phosphorescent dopants, And the host materials corresponding to fluorescent or phosphorescent dopants respectively.

In a specific embodiment, the organic layer containing the pyridine-substituted diphenylpyrimidine compound of the present invention is preferably an electron transport layer, and its thickness is 20 nm to 30 nm; wherein, the electron transport layer may The pyridine substituted diphenylpyrimidine compound is used as a single material, or the pyridine substituted diphenylpyrimidine compound is used in combination with an electrically conductive dopant.

In another embodiment, the electron transport layer contains N-type electricity Sexually conductive dopants.

The N-type electrically conductive dopant used in the electron transport layer can be nitrate, carbonate, phosphate or quinolinate of organic alkali metal/alkaline earth metal. Specifically, such as lithium carbonate, lithium quinolate (Liq), lithium azide (lithium azide), rubidium carbonate, silver nitrate, barium nitrate, magnesium nitrate, zinc nitrate, cesium nitrate, cesium carbonate, cesium fluoride , Cesium azide, etc., among them, the N-type electrically conductive dopant is particularly preferably lithium quinolinate.

In a specific embodiment, the content of the N-type electrically conductive dopant is 5% to 50% by weight based on the weight of the electron transport layer.

The structure of the organic electroluminescent device of the present invention will be described in conjunction with the drawings.

Figure 1 is a schematic cross-sectional view of a specific embodiment of the organic electroluminescent device of the present invention. The organic electroluminescent device 100 includes a substrate 110, an anode 120, a hole injection layer 130, a hole transport layer 140, a light emitting layer 150, an electron transport layer 160, an electron injection layer 170, and a cathode 180. The organic electroluminescent device 100 can be fabricated by sequentially depositing the above-mentioned layers.

Figure 2 is a schematic cross-sectional view of another embodiment of the organic electroluminescent device of the present invention. The organic electroluminescent element 200 includes a substrate 210, an anode 220, a hole injection layer 230, a hole transport layer 240, an exciton blocking layer 245, a light emitting layer 250, an electron transport layer 260, an electron injection layer 270 and a cathode 280, and a The difference in Figure 1 is that the exciton blocking layer 245 is disposed between the hole transport layer 240 and the light emitting layer 250.

Figure 3 is a schematic cross-sectional view of another embodiment of the organic electroluminescent device of the present invention. The organic electroluminescent element 300 includes a substrate 310, The anode 320, the hole injection layer 330, the hole transport layer 340, the light-emitting layer 350, the exciton blocking layer 355, the electron transport layer 360, the electron injection layer 370, and the cathode 380. The difference from Figure 1 lies in the exciton blocking layer 355 is provided between the light emitting layer 350 and the electron transport layer 360.

The organic electroluminescent device can be manufactured according to the reverse structure of the device shown in Figure 1 to Figure 3. One or more layers can be added or removed in these reversed structures as required.

The material of the hole injection layer, hole transport layer, exciton blocking layer, electron blocking layer, and electron injection layer can be selected from conventional materials. For example, the electron transport material forming the electron transport layer is different from the light emitting layer material And it has electron transport properties, which promotes the migration of electrons in the electron transport layer, and prevents the accumulation of carriers caused by the difference in dissociation energy between the light-emitting layer and the electron transport layer.

The pyridine-substituted diphenylpyrimidine compound of the present invention with the structure of formula (I) is used in the electron transport layer, because it has a triplet energy (E _T ) higher than 2.45 eV and a very low highest occupied molecular orbital (HOMO) Energy level and good carrier mobility make the holes in the light-emitting layer not easy to lose, and at the same time make the electrons effectively transport to the light-emitting layer, help the density balance of the electrons and holes in the light-emitting layer, increase the luminous efficiency and Drive stability.

In addition, US Patent No. 5,844,363 discloses a flexible transparent substrate combined with an anode, the entire content of which is cited in the present invention. As illustrated in US Patent No. 20170005275A1, the p-type doped hole transport layer is doped with HT-D2 in HT3, the entire content of which is cited in the present invention, and the patent also uses Lithium quinolate (Liq) as the n-type Doped material It is doped in the electron transport material (ET3), the entire content of which is cited in the present invention. The entire contents of the cathode as exemplified in US Patent Nos. 5703436 and 5707745 are cited in the present invention. The cathode has a thin metal layer, such as magnesium/silver (Mg: Ag), and a transparent conductive layer covered with the metal thin layer by sputtering deposition. Layer (ITO Layer). The application and principle of each barrier layer disclosed in US Patent Nos. 6097147 and 20030230980 are all cited in the present invention. The injection layer illustrated in US Patent No. 20040174116 and the protective layer illustrated in the same case are all cited in the present invention.

Structures and materials that are not specifically described can also be applied to the present invention. As disclosed in US Patent No. 5247190, organic electroluminescent devices including polymer materials (PLEDs), the entire contents of which are cited in the present invention. Furthermore, the organic electroluminescent device with a single organic layer or the organic electroluminescent device stacked as disclosed in US Patent No. 5,707,745, the entire contents of which are cited in the present invention.

Unless otherwise limited, any layer in different embodiments can be deposited and formed using any appropriate method. As far as the organic layer is concerned, preferred methods include thermal evaporation and spray printing as disclosed in US Patent Nos. 6013982 and 6087196, the entire contents of which are cited in the present invention; organic vapor deposition disclosed in US Patent No. 6,337,102 Method (organic vapor phase deposition, OVPD), the entire content of which is cited in the present invention; the organic vapor phase deposition method (deposition by organic vapor jet printing, OVJP) disclosed in US Patent No. 10/233470, the entire content of which is Quoted in this invention. Other suitable methods include spin coating and solution-based processes. The solution-based process is preferably carried out in a nitrogen or inert gas environment. Correct For other layers, the preferred method includes thermal evaporation. The preferred patterning method includes the process of mask deposition and then cold welding as disclosed in US Patent Nos. 6,294,398 and 6,468,819, and a process of integrated spray printing or organic vapor spray deposition and patterning, all of which are the present invention Cited. Of course, other methods can also be used. The material used for deposition can be adjusted to correspond to the specific deposition method used.

The pyridine-substituted diphenylpyrimidine compound of the present invention with the structure of formula (I) can be vacuum-deposited into an amorphous film applied to an organic electroluminescent device. When the compound is used in any of the above organic layers, it exhibits a longer service life and good thermal stability.

The organic electroluminescent element of the present invention can be applied to a single element, and its structure is an array configuration or an element with anode and cathode in the X-Y coordinate of the array. Compared with conventional devices, the present invention can significantly improve the service life and driving stability of organic electroluminescent devices. In addition, combined with the phosphorescent dopants in the light-emitting layer, the organic electroluminescent element of the present invention can achieve better performance and emit white light when applied to full-color or colorful display panels.

The following examples illustrate many properties and effects of the present invention in detail. The detailed embodiments are only used to illustrate the nature of the present invention, and the present invention is limited to those exemplified in the specific embodiments.

Synthesis Example 1: Synthesis of Compound 2-1

Combine 3-Pyridyl boronic acid (96.34g, 783.76mmole) with 4-Bromoacetophenone (130g, 653.14mmole), and potassium carbonate (225.66g, 1632.85mmole). Add 1950 ml of toluene, 317 ml of ethanol, and 634 ml of deionized water to the reaction flask. After installing nitrogen and condenser, move the reaction flask to an oil pan and heat to raise the temperature to 80°C. 37.72 grams of tetrakis (triphenylphosphine) palladium (Pd(PPh ₃ ) ₄ ) was added to the reaction, and the temperature was raised to 80°C and refluxed for 16 hours. After the reaction was completed, the temperature was lowered. The water layer was removed and concentrated to a viscosity After that, toluene was added and heated through a column containing 40 grams of alumina and 100 grams of silica. After concentrating the filtrate to viscous, it was poured into a beaker and allowed to stand still. After precipitation and filtration, a gray solid was obtained. After drying, 118 grams of gray solid 1-(4-pyridin-3-ylphenyl)-ethanone (1-( 4-Pyridin-3-yl-phenyl)-ethanone), the yield was 91.6%.

Combine 1-(4-pyridin-3-ylphenyl)-ethanone (1-(4-Pyridin-3-yl-phenyl)-ethanone) (50g, 253.5lmmole), 4-bromobenzaldehyde (4-bromo -benzaldehyde) (44.67g,241.44mmole), then add 893ml of ethanol and stir in the reaction flask, finally add sodium tert-butoxide (34.77g, 362.16mmole) and stir at room temperature. After the reaction is complete, add Add 200 ml of deionized water and stir and filter. After the filtered solid is washed with deionized water and methanol, the solid is then filtered with 100 ml of deionized water and 200 ml of methanol for 30 minutes, and the solid is dried twice to obtain 48. G light yellow solid 3-(4-bromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone(3-(4-Bromo-phenyl)-1-(4-pyridin-3-yl -phenyl)-propanone), the yield was 54.58%.

Add 3-(4-Bromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone(3-(4-Bromo-phenyl)-1-(4-pyridin-3-yl-phenyl) -propanone) (16g, 45.29mmole), Benzamidine hydrochloride (10.64g, 67.94mmole), potassium phosphate (33.64g, 158.52mmol) and 160ml of xylene were placed in the reaction flask under heating and stirring Keep reflux at 140°C, cool to 90°C after the reaction is complete, add 100 ml of deionized water and stir for 5 minutes, remove the water layer, concentrate the organic layer until a solid precipitates, rinse the solid with ethyl acetate and filter to obtain a white The solid, dried to obtain 9 grams of white solid 4-(4-bromophenyl)-2-phenyl-6-(4-pyridin-3-ylphenyl)-pyrimidine (4-(4-Bromo-phenyl) -2-phenyl-6-(4-pyridin-3-yl-phenyl)-pyrimidine), the yield was 42.91%.

Combine 4-Dibenzofuranboronic acid (2.55g, 11.91mmole), 4-(4-bromophenyl)-2-phenyl-6-(4-pyridin-3-ylphenyl) -Pyrimidine (4-(4-Bromo-phenyl)-2-phenyl-6-(4-pyridin-3-yl-phenyl)-pyrimidine) (4.64g, 9.92mmole), and potassium carbonate (3.46g, 25mmol) Put it in the reaction flask, add 75ml of toluene, 15ml of ethanol, 30ml of deionized water, install nitrogen and condenser, and move the reaction flask to the oil pot, heat and stir to 80℃, (Triphenylphosphine) palladium (0.58g, 0.5mmole) was added to the reaction flask, after the reaction was complete, and a solid precipitated, remove the oil bath and cool down, then filter, pour the filter cake into a beaker and add 100 ml of Stir the ionized water for 10 minutes and then filter, then transfer the filter cake to a beaker, add 250 ml of tetrahydrofuran, heat and stir until it is completely dissolved, pass through a column containing 20 g of silica, concentrate the filtrate until a white solid precipitates, and then use ethyl acetate The ester was washed and filtered, and after drying, 4.3 g of white solid compound 2-1 was obtained, and the yield was 78.57%.

1H NMR(CDC13,400MHz)δ9.04-9.05(d,1H),8.63-8.75(m,8H), 8.18-8.25(m,5H),8.01-8.04(d,2H),7.85-7.87(d ,1H),7.77-7.79(d,1H),7.53-7.66(m,6H),7.43-7.48(t,1H)

Synthesis Example 2: Synthesis of Compound 2-3

Combine 3-Pyridyl boronic acid (96.34g, 783.76mmole) with 4-Bromoacetophenone (130g, 653.14mmole), and potassium carbonate (225.66g, 1632.85mmole). Add 1950 ml of toluene, 317 ml of ethanol, and 634 ml of deionized water to the reaction flask. After installing nitrogen and condenser, move the reaction flask to an oil pan and heat to raise the temperature to 80°C. 37.72 grams of tetrakis (triphenylphosphine) palladium (Pd(PPh ₃ ) ₄ ) was added to the reaction, and the temperature was raised to 80°C and refluxed for 16 hours. After the reaction was completed, the temperature was lowered. The water layer was removed and concentrated to a viscosity After that, toluene was added and heated through a column containing 40 grams of alumina and 100 grams of silica. After concentrating the filtrate to viscous, it was poured into a beaker and allowed to stand still. After precipitation and filtration, a gray solid was obtained. After drying, 118 g of gray solid 1-(4-pyridin-3-ylphenyl)-ethanone (1-( 4-Pyridin-3-yl-phenyl)-ethanone), the yield was 91.6%.

Add 1-(4-pyridin-3-ylphenyl)-ethanone (1-(4-Pyridin-3-yl-phenyl)-ethanone) (50g, 253.51mmole), 4-bromobenzaldehyde (4-bromo -benzaldehyde) (44.67g,241.44mmole), then add 893ml of ethanol and stir in the reaction flask, and finally add sodium tert-butoxide (34.77g,362.16mmole) and stir at room temperature. After the reaction is complete, add 200ml of Stir and filter the deionized water. Wash the filtered solid with deionized water and methanol. Stir and filter the solid with 100 ml of deionized water and 200 ml of methanol for 30 minutes. Repeat twice to dry the solid to obtain 48 g of light yellow solid 3 -(4-Bromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone(3-(4-Bromo-phenyl)-1-(4-pyridin-3-yl-phenyl)-propanone) , The yield is 54.58%.

Add 3-(4-Bromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone(3-(4-Bromo-phenyl)-1-(4-pyridin-3-yl-phenyl)- propanone) (16g, 45.29mmole), 3-Amidinopyridinium chloride (10.71g, 67.94mmole), potassium phosphate (33.64g, 158.52mmole), and 200ml of xylene were placed Heat and stir in the reaction flask to maintain a reflux at 140°C. After the reaction, the temperature is reduced to 90°C. After adding 100 ml of deionized water and stirring for 5 minutes, remove the water layer. After the organic layer was concentrated until the solid precipitated, the solid was washed with ethyl acetate and filtered to obtain a white solid. After drying, 8.5 g of white solid 4-(4-bromophenyl)-2-pyridin-3-yl-6-(4) -Pyridin-3-ylphenyl)-pyrimidine (4-(4-Bromo-phenyl)-2-pyridin-3-yl-6-(4-pyridin-3-yl-phenyl)-pyrimidine), the yield is 39.45%.

Combine 4-Dibenzofuranboronic acid (2.55g, 12mmole) with 4-(4-bromophenyl)-2-pyridin-3-yl-6-(4-pyridin-3-yl) Phenyl)-pyrimidine (4-(4-Bromo-phenyl)-2-pyridin-3-yl-6-(4-pyridin-3-yl-phenyl)-pyrimidine) (4.65g, l0mmole), and potassium carbonate (3.46g, 25mmole) placed in the reaction flask, then add 75ml of toluene, 15ml of ethanol, 30ml of deionized water, install nitrogen and condenser, move the reaction flask to the oil pan, heat and stir To 80°C, add tetrakis(triphenylphosphine)palladium (0.58g, 0.5mmole) into the reaction flask, after the reaction is complete, and solids precipitate out, remove the oil bath and cool down, then filter, and pour the filter cake into a beaker Add 100 ml of deionized water and stir for 10 minutes, then filter, then transfer the filter cake to a beaker, add 250 ml of tetrahydrofuran, heat and stir until it is completely dissolved, pass through a column containing 20 g of silica, and concentrate the filtrate to a white solid After precipitation, rinse and filter with ethyl acetate, and dry to obtain 4.3 g of white solid compound 2-3, the yield was 77.81%.

1H NMR (CDC13, 400MHz), δ9.96 (1H, d), 8.89-9.0 (1H, tt), 8.96-9.97 (1H, d), 8.77-8.79 (1H, dd), 8.66-8.67 (1H, dd), 8.48-8.50 (2H, d), 8.43-8.46 (2H, d), 8.15-8.20 (3H, t), 7.97-8.03 (3H, m), 7.81-7.84 (2H, d), 7.70- 7.73 (1H, d), 7.64-7.66 (1H, d), 7.48-7.53 (3H, m), 7.38-7.46 (2H, m)

Synthesis Example 3: Synthesis of Compound 3-3

Combine 1-(4-pyridin-3-ylphenyl)-ethanone (1-(4-Pyridin-3-yl-phenyl)-ethanone) (75g, 380.26mmole), 3-bromobenzaldehyde (3-bromo -benzaldehyde) (67g, 362.16mmole), then add 1340ml of ethanol and stir in the reaction flask, and finally add sodium tert-butoxide (52.7g, 543.23mmole) and stir at room temperature. After the reaction is complete, add 200ml of Stir and filter the deionized water. After the filtered solids are washed with deionized water and methanol, the solids are then stirred with 100 ml of deionized water and 200 ml of methanol for 30 minutes and filtered, and the solids are dried twice to obtain 78 g of pale yellow solids. 3-(3-Bromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone(3-(3-Bromo-phenyl)-1-(4-pyridin-3-yl-phenyl)- propanone), The yield was 88.7%.

Add 3-(3-bromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone(3-(3-Bromo-phenyl)-1-(4-pyridin-3-yl-phenyl) -propanone) (26g, 71.38mmole), 3-Amidinopyridinium chloride (17.4g, 110.4mmole), potassium phosphate (54.28g, 257.6mmole), and 260ml of xylene Heat and stir in the reaction flask to maintain reflux at 140°C. After the reaction, the temperature is reduced to 90°C. After adding 100 ml of deionized water and stirring for 5 minutes, the water layer is removed, and the organic layer is concentrated until a solid precipitates. The solid was washed and filtered to obtain a white solid. After drying, 5.2 g of white solid 4-(3-bromophenyl)-2-pyridin-3-yl-6-(4-pyridin-3-ylphenyl)-pyrimidine ( 4-(3-Bromo-phenyl)-2-pyridin-3-yl-6-(4-pyridin-3-yl-phenyl)-pyrimidine), the yield was 15.18%.

Combine 4-Dibenzofuranboronic acid (5.09g, 23.77mmole), 4-(3-bromophenyl)-2-pyridin-3-yl-6-(4- Pyridin-3-ylphenyl)-pyrimidine (4-(3-Bromo-phenyl)-2-pyridin-3-yl-6-(4-pyridin-3-yl-phenyl)-pyrimidine) (9.92g, 19.81 mmole), and potassium carbonate (6.84g, 49.49mole) in the reaction flask, then add 138ml of toluene, 23ml of ethanol, 46ml of deionized water, install nitrogen and condenser, and move the reaction flask to In an oil pan, heat and stir to 80°C, add tetrakis(triphenylphosphine)palladium (1.14g, 0.99mmole) into the reaction flask, after the reaction is complete, and solids precipitate out, remove the oil bath and filter after cooling. Pour the filter cake into a beaker, add 100 ml of deionized water and stir for 10 minutes, then filter, then move the filter cake to the beaker, add 250 ml of tetrahydrofuran, heat and stir until it is completely dissolved, and pass through a column containing 20 g of silica. After the filtrate was concentrated until a white solid precipitated, it was washed and filtered with ethyl acetate, and dried to obtain 5.52 g of a white solid compound 3-3 with a yield of 50.5%.

1H NMR (CDC13, 400MHz), δ9.97 (1H, s), 8.99-9.02 (1H, d), 8.96 (1H, s), 8.85 (1H, s), 8.77-8.79 (1H, d), 8.64 -8.67(1H,d),8.43-8.45(2H,d),8.34-8.36(1H,d),8.22(1H,s),8.12-8.16(1H,d),7.7-8.03(3H,m) ,7.78-7.82(2H,m),7.74-7.77(2H,t),7.64-7.66(1H,d),7.48-7.53(3H,m),7.38-7.46(2H,m)

Synthesis Example 4: Synthesis of Compound 5-1

Combine 1-(4-pyridin-3-ylphenyl)-ethanone (1-(4-Pyridin-3-yl-phenyl)-ethanone) (33g, 166.8mmole), 3,5-dibromobenzaldehyde ( 3,5-Dibromo-benzaldehyde) (42.06g, 159.34mmole), and 840 ml of ethanol were added to the reaction flask and stirred, and finally sodium tert-butoxide (22.94g, 239mmole) was added and stirred at room temperature. After the reaction was complete , Add 200 ml of deionized water and stir and filter. After the filtered solid is washed with deionized water and methanol, the solid is then filtered with 100 ml of deionized water and 200 ml of methanol for 30 minutes, and the solid is dried twice. 55 grams of light yellow solid 3-(3,5-Dibromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone (3-(3,5-Dibromo-phenyl)-1-(4 -pyridin-3-yl-phenyl)-propanone), the yield was 77.89%.

Add 3-(3,5-Dibromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone (3-(3,5-Dibromo-phenyl)-1-(4-pyridin-3 -yl-phenyl)-propanone) (35g, 79mmole), benzamidine hydrochloride (Benzamidine hydrochloride) (18.55g, 118.5mmole), potassium phosphate (58.69g, 276.9mmole), and 350ml of xylene were placed in a reaction flask, heated and stirred to maintain reflux at 140°C, after the reaction, the temperature was reduced to 90°C, and 100ml was added After stirring the deionized water for 5 minutes, the water layer was removed, and the organic layer was concentrated until the solid precipitated. The solid was washed with ethyl acetate and filtered to obtain a white solid. After drying, 17 grams of white solid 4-(3,5- Dibromophenyl)-2-phenyl-6-(4-pyridin-3-ylphenyl)-pyrimidine(4-(3,5-Dibromo-phenyl)-2-phenyl-6-(4-pyridin- 3-yl-phenyl)-pyrimidine), the yield was 39.6%.

Combine 1-Naphthaleneboronic acid (8.26g, 48mmole), 4-(3,5-dibromophenyl)-2-phenyl-6-(4-pyridin-3-ylphenyl)- Pyrimidine (4-(3,5-Dibromo-phenyl)-2-phenyl-6-(4-pyridin-3-yl-phenyl)-pyrimidine) (10.86g, 20mmole), and potassium carbonate (13.82g, 100mmole) Place it in the reaction flask, add 136ml of toluene, 27ml of ethanol and 54ml of deionized water, install nitrogen and condenser, and move the reaction flask to an oil pan, heat and stir to 80℃, (Triphenylphosphine) palladium (2.31g, 2mmole) is added to the reaction flask, after the reaction is complete, and solids precipitate out, remove the oil bath to cool down, filter, pour the filter cake into a beaker and add Stir 100 ml of deionized water for 10 minutes and then filter, then transfer the filter cake to a beaker, add 250 ml of tetrahydrofuran, heat and stir until it is completely dissolved, pass through a column containing 20 g of silica, and concentrate the filtrate until a white solid precipitates. After washing and filtering with ethyl acetate, 10 grams of white solid compound 5-1 was obtained after drying, and the yield was 78.5%.

1H NMR(CDC13,400MHz)δ8.91-8.92(d,1H), 8.68-8.72(m,2H), 8.61-8.63(m,1H), 8.49-8.5(d,2H), 8.39-8.41(d ,2H),8.07-8.13(t,3H),7.91-7.98(m,5H),7.83-7.84(t,1H),7.73-7.75(d,2H),7.61-7.65(m,3H),7.58 -7.6(d,1H),7.52-7.55(m,2H),7.48-7.52(m,5H),7.37-7.41(m,3H)

Synthesis Example 5: Synthesis of Compound 5-2

Combine 1-(4-pyridin-3-ylphenyl)-ethanone (1-(4-Pyridin-3-yl-phenyl)-ethanone) (33g, 166.8mmole), 3,5-dibromobenzaldehyde ( 3,5-Dibromo-benzaldehyde) (42.06g, 159.34mmole), then add 840 ml of ethanol and stir in the reaction flask, and finally add sodium tert-butoxide (22.94g, 239mmole) and stir at room temperature. After the reaction is complete , Add 200 ml of deionized water and stir and filter. After the filtered solid is washed with deionized water and methanol, the solid is then used to 100 ml of deionized water. Stir water and 200 ml of methanol for 30 minutes and filter, repeat twice to dry the solid to obtain 55 g of pale yellow solid 3-(3,5-dibromophenyl)-1-(4-pyridin-3-ylphenyl) -Acetone (3-(3,5-Dibromo-phenyl)-1-(4-pyridin-3-yl-phenyl)-propanone), the yield was 77.89%.

Add 3-(3,5-Dibromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone (3-(3,5-Dibromo-phenyl)-1-(4-pyridin-3 -yl-phenyl)-propanone) (25g, 56.41mmole), 4-Amidinopyridinium chloride (13.25.g, 84.06mmole), potassium phosphate (35.92g, 158.94mmole), and Put 250 ml of xylene in the reaction flask and heat and stir to maintain 140°C reflux. After the reaction, the temperature is reduced to 90°C. After adding 100 ml of deionized water and stirring for 5 minutes, the water layer is removed, and the organic layer is concentrated until a solid precipitates. Then, the solid was washed with ethyl acetate and filtered to obtain a white solid. After drying, 12.3 grams of white solid 4-(3,5-dibromophenyl)-2-pyridin-4-yl-6-(4-pyridine- 3-ylphenyl)-pyrimidine (4-(3,5-Dibromo-phenyl)-2-pyridin-4-yl-6-(4-pyridin-3-yl-phenyl)-pyrimidine), the yield was 39.92 %.

Combine 1-Naphthaleneboronic acid (9.88g, 57.32mmole), 4-(3,5-dibromophenyl)-2-pyridin-4-yl-6-(4-pyridin-3-yl) Phenyl)-pyrimidine (4-(3,5-Dibromo-phenyl)-2-pyridin-3-yl-6-(4-pyridin-3-yl-phenyl)-pyrimidine) (13g, 23.88mmole), Potassium carbonate (16.5g, 119.4mmole) was placed in the reaction flask, then 195ml of toluene, 32ml of ethanol and 64ml of deionized water were added, nitrogen and condenser were installed, and the reaction flask was moved to the oil pan , Heating and stirring to 80 ℃, add tetrakis (triphenylphosphine) palladium (2.76g, 2.39mmole) into the reaction flask, after the reaction is complete, and there is solid precipitation, remove the oil bath to cool down, filter, and pour the filter cake Put 100 ml of deionized water into the beaker and stir for 10 minutes, then filter, then move the filter cake to the beaker, add 250 ml of tetrahydrofuran, heat and stir until it is completely dissolved, pass through a column containing 20 g of silica, and concentrate the filtrate to After the white solid precipitated, it was washed and filtered with ethyl acetate, and dried to obtain 13 g of white solid compound 5-2, with a yield of 85.51%.

1H NMR(CDC13,400MHz)δ8.95(s,1H), 8.82-8,83(d,2H),8.64-8.66(d,1H),8.59-8.61(d,2H), 8.48(s,2H) ), 8.38-8.4(d,2H),8,25(s,1H),8.04-8,06(m,2H),7.95-7,98(m,4H),7.92(s,1H), 7.77-7,79(d,,2H),7.67-7.79(d,1H),7.62-7,62(m,3H),7.42-7.48(m,4H),7.42-7.43(m,2H)

Synthesis Example 6: Synthesis of Compound 5-3

Combine 1-(4-pyridin-3-ylphenyl)-ethanone (1-(4-Pyridin-3-yl-phenyl)-ethanone) (33g, 166.8mmole), 3,5-dibromobenzaldehyde ( 3,5-Dibromo-benzaldehyde) (42.06g, 159.34mmole), and 840ml of ethanol were added to the reaction flask and stirred, and finally sodium tert-butoxide (22.94g, 239mmole) was added and stirred at room temperature. After the reaction was complete, Add 200 ml of deionized water and stir and filter. The filtered solid is washed with deionized water and methanol. The solid is then stirred with 100 ml of deionized water and 200 ml of methanol for 30 minutes and filtered. Repeat twice to dry the solid to obtain 55 g of light. Yellow solid 3-(3,5-Dibromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone (3-(3,5-Dibromo-phenyl)-1-(4-pyridin- 3-yl-phenyl)-propanone), the yield was 77.89%.

Add 3-(3,5-Dibromophenyl)-1-(4-pyridin-3-ylphenyl)-acetone 3-(3,5-Dibromo-phenyl)-1-(4-pyridin-3- yl-phenyl)-propanone (34g, 76.73mmole), 3-Amidinopyridinium chloride (18.02g, 11.43mmole), potassium phosphate (57g, 268.56mmole), and 340ml of two Put the toluene in the reaction flask and heat and stir to maintain 140°C reflux. After the reaction, the temperature is lowered to 90°C. After adding 100 ml of deionized water and stirring for 5 minutes, the water layer is removed, and the organic layer is concentrated until solids are deposited. The solid was washed with ethyl ester and filtered to obtain a white solid, which was dried to obtain 22 g of white solid 4-(3,5-dibromophenyl)-2-pyridin-3-yl-6-(4-pyridin-3-ylbenzene) Yl)-pyrimidine (4-(3,5-Dibromo-phenyl)-2-pyridin-3-yl-6-(4-pyridin-3-yl-phenyl)-pyrimidine), the yield was 52.69%.

Combine 1-Naphthaleneboronic acid (9.88g, 57.32mmole), 4-(3,5-dibromophenyl)-2-pyridin-3-yl-6-(4-pyridin-3-yl) Phenyl)-pyrimidine (4-(3,5-Dibromo-phenyl)-2-pyridin-3-yl-6-(4-pyridin-3-yl-phenyl)-pyrimidine) (13g, 23.88mmole), and potassium carbonate (16.5g , 119.4mmole) placed in the reaction flask, then add 195ml of toluene, 32ml of ethanol and 64ml of deionized water, install nitrogen and condenser, and move the reaction flask to the oil pot, heating and stirring to 80 ℃, add tetrakis (triphenylphosphine) palladium (2.76g, 2.39mmole) into the reaction flask, after the reaction is complete, and solid precipitation, remove the oil bath to cool down, filter, pour the filter cake into a beaker and add 100 Stir 1ml of deionized water for 10 minutes and then filter, then transfer the filter cake to a beaker, add 250ml of tetrahydrofuran and heat and stir until it is completely dissolved, pass through a column containing 20g of silica, concentrate the filtrate until a white solid precipitates Then, it was washed and filtered with ethyl acetate. After drying, 12 grams of white solid compound 5-3 was obtained. The yield was 78.91%.

1H NMR (CDC13, 400MHz) δ 9.89 (d, 1H), 8.92-8.95 (m, 2H), 8.72-8.75 (m, 1H), 8.63-8.66 (d, 1H), 8.5 (s, 2H), 8.38-8.43(d,2H),8,2(s,1H),8.19-8,23(m,2H),7.92-7,99(m,5H),7.86-7.88(s,1H),7.76 -7,79(d,,2H),7.58-7.66(m,4H),7.48-7,56(m,4H),7.39-7.46(m,2H)

The physical property values of the above-mentioned materials are shown in Table 2. The measuring methods of each physical property value are as follows.

(1) Thermal cracking temperature (T _d )

A thermogravimetric analyzer (Perkin Elmer, TGA 8000) was used for measurement. Under normal pressure and a nitrogen atmosphere, the thermal pyrolysis properties of the prepared compounds were measured at a temperature program rate of 20°C/min. The temperature at which the weight is reduced to 95% of the initial weight is the thermal cracking temperature (T _d ).

(2) Glass transition temperature (T _g )

A differential scanning thermal analyzer (DSC; Perkin Elmer, DSC 8000) was used to measure the prepared compound at a temperature program rate of 20°C/min.

(3) Energy level value of the highest occupied molecular orbital (HOMO)

In addition, the compound is made into a thin film state, and the ionization potential value is measured with a photoelectron spectrophotometer (Riken Keiki, Surface Analyzer) under the atmosphere, and the value is further converted to the HOMO energy level value.

(4) Energy level of the lowest unoccupied molecular orbital (LUMO)

The film of the above compound was measured with a UV/VIS spectrophotometer (Perkin Elmer, Lambda 20) to measure the onset of its absorption wavelength, and the value was converted into an energy gap value, so that the energy gap value and the HOMO energy level Subtract the value to get the LUMO energy level.

(5) Triplet energy value (ET)

Measure the luminescence spectrum with a fluorescence spectrometer (Perkin Elmer, LS 55) at a temperature of 77K, and then calculate it to obtain E _T.

Example 1: Manufacturing of organic electroluminescent device

Before the substrate is loaded into the evaporation system for use, the substrate is cleaned with solvent and ultraviolet ozone for degreasing. After that, the substrate is transferred to a vacuum deposition chamber, and all layers are deposited on top of the substrate. The layers shown in Figure 2 are deposited sequentially by a heated evaporation boat at a vacuum of about 10 ^-6 Torr: a) Hole injection layer, thickness 20nm, including 9% doped body P-type electrically conductive dopant HTM, wherein the p-type electrically conductive dopant is purchased from Shanghai Hanfeng Chemical Co., Ltd., and the HTM is purchased from Merck & Co., Inc.; b) hole transport layer, thickness 170 nanometers, HTM; c) exciton blocking layer, thickness 10 nanometers, HT (manufactured by Yule Optoelectronics); d) light emitting layer, thickness 25 nanometers, including EBH doped with 4% volume ratio BD, of which, BD and EBH are prepared by Yulei Optoelectronics; e) Electron transport layer, thickness 25nm, containing compound 2-1 and doped lithium quinolate (Liq, Yulei Optoelectronics), the volume ratio is 1:1; f) Electron injection layer, thickness 0.5nm, lithium fluoride (LiF); and g) cathode, thickness about 180nm, including A1.

The device structure can be expressed as: ITO/HTM: p-type electrically conductive dopant (20 nm)/HTM (170 nm)/HT (10 nm)/EBH: BD (25 nm)/compound 2-1 ：Liq(25nm)/LiF(0.5nm)/A1(180nm).

After the above-mentioned layers are deposited and formed, the device is transported from the deposition chamber to the drying box, and then encapsulated with a UV curable epoxy resin and a glass cover plate containing a moisture absorbent. The organic electroluminescence element has a light-emitting area of 9 square millimeters.

Examples 2 to 6: Manufacturing of organic electroluminescent devices

Except that the compound 2-1 of the electron transport layer in Example 1 was replaced with compounds 2-3, 3-3, 5-1, 5-2, and 5-3, respectively, Example 2, Example 3, and Example 4 , Example 5 and Example 6 are the same as the layer structure of Example 1.

Comparative Example 1: Manufacturing of organic electroluminescent device

The organic electroluminescent element is placed into a layer structure similar to that of Example 1, except that the compound 1-1 of the electron transport layer in Example 1 is replaced with compound EET09, the structure of the organic electroluminescent element can be expressed as: ITO/HTM: p dopant(20nm)/HTM(170nm)/HT(10nm)/EBH: BD(25nm)/compound EET09: Liq(25nm)/LiF(0.5nm) )/Al(180nm).

Among them, the compound EET09 is as described in Japanese Patent No. 2011003793A.

The electroluminescence properties of the above-mentioned organic electroluminescence elements all use constant current source (KEITHLEY 2400 Source Meter, made by Keithley Instruments, Inc., Cleveland, Ohio) and photometer (PHOTO RESEARCH SpectraScan PR 650, made by Photo). ReSearch, Inc., Chatsworth, Calif.) measured its luminescence properties at room temperature. Based on the organic electroluminescent device of the comparative example (standard value is 1), the values of its driving voltage, luminous efficiency and LT95 are listed Shown in Table 3. Among them, the LT95 value is defined as the time it takes for the brightness level to drop to 95% relative to the initial brightness, and it is used as a measure of the service life or stability of the organic electroluminescent device.

As described above, within the range of acceptable driving voltage and luminous efficiency loss, it can be seen that the organic electroluminescent device comprising the pyridine-substituted diphenylpyrimidine compound with the structure of formula (I) of the present invention exhibits good heat resistance and Significantly improve its service life, therefore, the organic electroluminescent element of the present invention is suitable It has extremely high technical value in application fields such as automotive displays.

The above-mentioned embodiments are only illustrative and not used to limit the present invention. Anyone familiar with this technique can modify and change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present invention is defined by the scope of the patent application attached to the present invention. As long as it does not affect the effect and implementation purpose of the present invention, it should be covered in the technical content of this disclosure.

200‧‧‧Organic electroluminescence element

210‧‧‧Substrate

220‧‧‧Anode

230‧‧‧hole injection layer

240‧‧‧Hole Transmission Layer

250‧‧‧Light-emitting layer

260‧‧‧Electron transport layer

270‧‧‧Electron injection layer

280‧‧‧Cathode

245‧‧‧ exciton barrier

Claims (10)

A pyridine substituted diphenylpyrimidine compound with the structure of formula (I):

Wherein, X ₁ represents a substituted or unsubstituted C _6-30 aryl group, a substituted or unsubstituted C _5-30 containing at least one heteroatom selected from the group consisting of N, O, and S Heteroaryl; A ₁ is selected from dibenzofuranyl or naphthyl; and n represents an integer of 1 or 2, and when n represents 2, A _{1 is} each the same; when A ₁ is dibenzofuranyl , Is one of the following compounds:

The pyridine-substituted diphenylpyrimidine compound with the structure of formula (I) as described in item 1 of the scope of patent application is represented by the structure of formula (I-1) or formula (I-2):

Wherein, X ₁ represents a substituted or unsubstituted C _6-30 aryl group, a substituted or unsubstituted C _5-30 containing at least one heteroatom selected from the group consisting of N, O, and S Heteroaryl. The pyridine-substituted diphenylpyrimidine compound with the structure of formula (I) as described in item 2 of the scope of patent application, wherein X ₁ is a monovalent group and is selected from substituted or unsubstituted pyridyl, Unsubstituted naphthyl, unsubstituted quinolinyl or unsubstituted phenyl. The pyridine-substituted diphenylpyrimidine compound with the structure of formula (I) as described in item 2 of the scope of patent application has the structure of formula (I-3), formula (I-4) or formula (I-5) Means:

The pyridine-substituted diphenylpyrimidine compound with the structure of formula (I) as described in item 1 of the scope of patent application, wherein when n is 1, the compound of formula (I) is of formula (I-6) or (I-7) shows:

The pyridine substituted diphenylpyrimidine compound with the structure of formula (I) as described in item 1 of the scope of patent application, wherein when n is 2, the compound of formula (I) is represented by formula (I-8) :

The pyridine-substituted diphenylpyrimidine compound with the structure of formula (I) as described in item 6 of the scope of patent application is one of the following compounds:

An organic electroluminescent element, comprising: a cathode; an anode; and an organic layer, which is interposed between the cathode and the anode, and the organic layer includes the structure of formula (I) as described in item 1 of the patent application Pyridine substituted diphenylpyrimidine compounds. The organic electroluminescent device described in item 8 of the scope of patent application, wherein the organic layer is an electron transport layer, and the thickness thereof is 20 nm to 30 nm. The organic electroluminescent device described in item 9 of the scope of patent application, wherein the electron transport layer contains N-type electrically conductive dopants, and the N The content of the type electrically conductive dopant is 5% to 50% by weight.

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