Phenyl biphenyl pyrimidine compound and organic electroluminescent device thereof

Abstract

A phenyl biphenyl pyrimidine compound having a structure of formula (I) and an organic electroluminescent device using the compound, in which X1, A1 and n are as defined in the specification. # imgabs0 #

Description

[0001] This invention is a divisional application. The application number of the parent application is 201811290088.X, the application date is October 31, 2018, and the name of the invention is “Phenylbiphenylpyrimidine compounds and organic electroluminescent devices thereof”. Technical Field

[0002] The invention relates to a material for an organic electroluminescent device and an organic electroluminescent device using the material. Background Art

[0003] Recently, organic electroluminescent devices (OLEDs) have become commercially attractive in high-density pixel displays with high luminous efficiency due to their advantages such as long life, high efficiency, low driving voltage, wide color gamut and low cost. In order to meet the application of organic electroluminescent devices, special emphasis is placed on the development of novel organic materials.

[0004] A typical OLED has at least one organic emissive layer sandwiched between an anode and a cathode. When an electric current is applied, the anode injects holes and the cathode injects electrons into the one or more organic emissive layers, and the injected holes and electrons each migrate to the opposite charged electrode. When electrons and holes are confined to the same molecule, an "exciton" is formed, which has a localized electron-hole pair in an excited energy state, and the exciton relaxes to emit light through a luminescence mechanism. In order to improve the charge transport capability and luminescence efficiency of such devices, one or more additional layers are combined with the light-emitting layer, such as an electron transport layer and / or a hole transport layer, or an electron blocking layer and / or a hole blocking layer. In the literature, it has been well documented to dope another guest material with the host material to improve device performance and adjust color. US 4769292, US 5844363, US 5707745, US 6596415 and US 6465115, which are incorporated herein by reference in their entirety, describe several OLED materials and device configurations. Yulei Optoelectronics Technology has applied for TW I582081 in 2016 and obtained it in 2017. The electron transport material introduced in this patent has certain novelty and effect, and the effect of this new patent application is better than that of the previous case.

[0005] The reasons for manufacturing an OLED with a multi-layer thin film structure include stabilizing the interface between the electrodes and the organic layers and matching the organic materials. In organic materials, the mobility of electrons and holes is significantly different. If appropriate hole transport and electron transport layers are used, holes and electrons can be effectively transported to the emission layer, so that the density of electrons and holes in the emission layer is balanced, increasing the luminous efficiency. Proper combination of the above-mentioned organic layers can improve the efficiency and life of the device. However, it is still difficult to find organic materials that meet the needs of all practical display applications, especially organic materials used in automotive displays or lighting sources, which need to have the properties of high temperature resistance and long life. Most common organic materials are only temperature resistant to 100°C.

[0006] Therefore, there is an urgent need for an organic material that can significantly improve the lifespan of organic electroluminescent devices and increase carrier mobility to meet the needs of diversified applications. Summary of the invention

[0007] The object of the present invention is to provide a material for an organic electroluminescent device having a long life, high carrier mobility and good heat resistance.

[0008] The present invention provides a phenylbiphenylpyrimidine compound having a structure of formula (I):

[0009]

[0010] wherein X1 and A1 are the same or different and each independently represents a substituted or unsubstituted C 6-30 an aryl group or a substituted or unsubstituted C group containing at least one heteroatom selected from the group consisting of N, O, and S 5-30 heteroaryl; and n represents an integer of 1 or 2, when n represents 1 and A1 is an unsubstituted phenyl group, the A1 is bonded to the para position relative to the pyrimidine part; when n represents 2, each A1 is the same or different.

[0011] In one embodiment of the phenylbiphenylpyrimidine compound of formula (I) of the present invention, X1 is selected from the group consisting of unsubstituted pyridyl, phenyl substituted with halogen, and C 1-4 For example, the phenyl biphenyl pyrimidine compound having the structure of formula (I) is selected from one of the following groups:

[0012] and

[0013]

[0014] In one embodiment of the phenylbiphenylpyrimidine compound having the structure of formula (I) of the present invention, A1 is a substituted or unsubstituted C 9-30Fused polycyclic aromatic, substituted or unsubstituted C 9-30 An aromatic hydrocarbon group or a substituted or unsubstituted C containing at least one heteroatom selected from the group consisting of N, O, and S 5-30 Condensed polycyclic aromatic hydrocarbon group.

[0015] More specifically, A1 is selected from one of the following groups:

[0016]

[0017] Wherein Ar1 represents an unsubstituted C 6-18 Arylene or a single bond connected to the compound of formula (I); Ar2 represents hydrogen or unsubstituted C 6-18 Aryl;

[0018] L represents N, N-R1, O or S, and R1 is unsubstituted C 6-18 Aryl; and

[0019] L1 represents N or N-R2, and R2 is an unsubstituted C 6-18 Arylene.

[0020] In one embodiment of the phenylbiphenylpyrimidine compound having the structure of formula (I) of the present invention, when n is 1, the compound of formula (I) is represented by formula (1-5) or formula (1-6):

[0021]

[0022] In another embodiment of the phenylbiphenylpyrimidine compound having the structure of formula (I) of the present invention, the compound is selected from one of the following groups:

[0023]

[0024]

[0025] In one embodiment of the phenylbiphenylpyrimidine compound having the structure of formula (I) of the present invention, when n is 2, the compound of formula (I) is represented by formula (1-7):

[0026]

[0027] The A1 are the same or different.

[0028] The present invention also provides an organic electroluminescent device, comprising: a cathode; an anode; and an organic layer between the cathode and the anode, wherein the organic layer comprises the phenylbiphenylpyrimidine compound having the structure of formula (I) of the present invention.

[0029] In one embodiment of the organic electroluminescent device of the present invention, the organic layer is an electron transport layer, and its thickness is 20 nanometers to 30 nanometers. In addition, the electron transport layer may also contain an N-type electrically conductive dopant, and the content of the N-type electrically conductive dopant is greater than 0 weight % to 50 weight %. For example, the N-type electrically conductive dopant is lithium quinolate.

[0030] In one embodiment of the organic electroluminescent device of the present invention, the organic layer further comprises a hole blocking layer, and the thickness of the hole blocking layer is greater than 0 nanometers to 5 nanometers.

[0031] According to the present invention, the phenylbiphenyl pyrimidine compound having the structure of formula (I) provided by the present invention has the advantages that the bonding position of the biphenyl group and the pyrimidine part can more effectively improve the life of the organic electroluminescent device prepared, increase the carrier mobility, and provide good heat resistance compared to other bonding positions. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Embodiments of the present invention are described by way of example with reference to the accompanying drawings:

[0033] Figure 1 is a cross-sectional schematic diagram of an embodiment of an organic electroluminescent device of the present invention;

[0034] Figure 2 is a cross-sectional schematic diagram of another embodiment of the organic electroluminescent device of the present invention; and

[0035] Figure 3 It is a cross-sectional schematic diagram of another embodiment of the organic electroluminescent device of the present invention.

[0036] The reference numerals are described as follows:

[0037] 100, 200, 300 organic electroluminescent devices

[0038] 110, 210, 310 substrate

[0039] 120, 220, 320 anode

[0040] 130, 230, 330 hole injection layer

[0041] 140, 240, 340 hole transport layer

[0042] 150, 250, 350 luminous layers

[0043] 160, 260, 360 electron transport layer

[0044] 170, 270, 370 electron injection layer

[0045] 180, 280, 380 cathode

[0046] 245, 345 electron blocking layer

[0047] 355 hole blocking layer. DETAILED DESCRIPTION

[0048] The following is an explanation of the embodiments of the present invention by means of specific specific examples. Those skilled in the art can easily understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied by means of other different embodiments, and the details in this specification can also be given different modifications and changes based on different viewpoints and applications without departing from the spirit disclosed by the present invention. In addition, all ranges and values ​​herein are inclusive and combinable. Any numerical value or point falling within the range described herein, such as any integer, can be used as a minimum value or maximum value to derive a lower range, etc.

[0049] In the text, "substituted" in the expression "substituted or unsubstituted" means that a hydrogen atom in a functional group is replaced by another atom or group (i.e., a substituent). Each of the substituents is 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 6-30 Aryl substituted C 5-30 Heteroaryl, benzimidazolyl, C 3-30 Cycloalkyl, C 5-7 Heterocycloalkyl, tri-C 1-30 Alkylsilyl, tri-C 1-30 Arylsilyl, di-C 1-30 Alkyl C 6-30 Arylsilyl, C 1-30 Alkyl di-C 6-30 Arylsilyl, C 2-30 Alkenyl, C 2-30 Alkynyl, cyano, di-C 1-30 Alkylamine, di-C 6-30 Aryl boron, di-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.

[0050] In one embodiment, the C 6-30 Aryl is selected from halogen, C 1-5 Alkyl, C 6-30 Aryl and C 5-30The heteroaryl group is substituted with at least one substituent in the group consisting of the heteroaryl group.

[0051] In another specific embodiment, the C 6-30 The aryl group is substituted with at least one substituent selected from the group consisting of halogen, methyl, phenyl, benzimidazolyl and carbazolyl.

[0052] In one embodiment, the C 5-30 Heteroaryl is C 6-30 The aryl group is substituted with an aromatic substituent.

[0053] In another specific embodiment, the C 6-30 The aryl group is substituted with a phenyl substituent.

[0054] As used herein, "aryl" refers to an aromatic group or an aromatic (ene) group, which refers to a monocyclic ring or a condensed ring derived from an aromatic hydrocarbon, and includes phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, phenylnaphthyl, naphthylphenyl, fluorenyl, phenylfluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthrenyl, phenylphenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrene, fused tetraphenyl, perylenyl, chrysenyl, naphthacene, fluoranthenyl, and the like.

[0055] Herein, "heteroaryl" means heteroaryl or (sub)heteroaryl, wherein the heteroaryl refers to an aromatic group containing at least one heteroatom selected from the group consisting of N, O, and S as the main chain atom of the ring, and may be a monocyclic ring, such as furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazole, oxazole, oxadiazole, triazine, tetrazine, triazole, tetrazolyl, furazanyl, pyridyl, pyrazine, pyrimidinyl, pyridazinyl, pyridazine), or a condensed ring condensed with at least one benzene ring, such as benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzisoxazolyl, quinolyl, isoquinolyl, cinnoline, quinazoline, quinoxaline, carbazole, phenoxazole, phenanthridine, benzodioxolyl, dihydroacridine, etc.

[0056] In one embodiment, preferred examples of the phenylbiphenylpyrimidine compounds having the structure of formula (I) are selected from Table 1, but are not limited thereto.

[0057] Table 1

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065] A typical synthesis route of an embodiment of the phenylbiphenylpyrimidine compound of formula (I) is described below, but the reaction for synthesizing the phenylbiphenylpyrimidine compound of formula (I) is not limited thereto.

[0066]

[0067] 4-Bromobenzaldehyde, 3-biphenylacetophenone and ethanol were added to the reaction flask and stirred. Then sodium tert-butoxide (NaO t Bu) or sodium hydroxide is added to the reaction flask and stirred together, and the mixture is reacted overnight at room temperature. After the reaction is complete, deionized water is added, stirred and filtered, and the filtered solid is first washed with deionized water and methanol, and then filtered with deionized water and methanol after stirring, and the washing and filtering steps are repeated twice, and then dried to obtain a white intermediate A.

[0068] Intermediate A, different formamidine hydrochloride derivatives and ethanol are added to a reaction flask and stirred, and then sodium tert-butoxide or sodium hydroxide is added to the reaction flask and stirred together, and then heating and stirring are started and reflux is maintained at 80°C. After the reaction is completed, the reaction temperature is cooled to 60°C, deionized water is added and stirred, and the water layer is removed, and the organic layer is concentrated until solids are precipitated, and then washed with ethyl acetate, filtered and dried to obtain a white intermediate B.

[0069] Intermediate B, different boronic acid derivatives and potassium carbonate are placed in a reaction flask, and tetrahydrofuran and deionized water are added. The reaction flask is placed in an oil bath, and after connecting nitrogen and a condenser, heating and stirring are started at 80°C. At the same time, tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) is added to the reaction flask for reflux. When the reaction is complete and solids are precipitated, the oil bath is removed, the temperature is lowered and filtered, and the filter cake is added with deionized water, stirred and filtered again, and the filter cake is added with tetrahydrofuran again. After heating and stirring until it is completely dissolved, a column containing silica is added for chromatography purification, and concentrated until a white solid is precipitated. After washing with ethyl acetate, filtering and drying, a white solid is obtained, which is the product.

[0070] The present invention also provides an organic electroluminescent device, comprising: a cathode; an anode; and an organic layer between the cathode and the anode, wherein the organic layer comprises the phenylbiphenylpyrimidine compound having the structure of formula (I) of the present invention.

[0071] The organic layer of the organic electroluminescent device of the present invention may 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 may also include 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, which is different from the organic layer, wherein the light-emitting layer further includes a fluorescent or phosphorescent dopant, and a host material corresponding to the fluorescent or phosphorescent dopant, respectively.

[0072] In a specific embodiment, the organic layer comprising the above-mentioned phenylbiphenylpyrimidine compound having a structure of formula (I) is preferably an electron transport layer, and its thickness is 20 nanometers to 30 nanometers; wherein, the electron transport layer can use the phenylbiphenylpyrimidine compound having a structure of formula (I) as a single material, or use the phenylbiphenylpyrimidine compound having a structure of formula (I) in combination with an electrically conductive dopant.

[0073] In another specific embodiment, the electron transport layer further comprises an N-type electrically conductive dopant, wherein the N-type electrically conductive dopant produces a chelation reaction with the phenylbiphenylpyrimidine compound having the structure of formula (I) of the present invention, so that electrons can be more easily injected from the cathode into the electron transport layer, thereby solving the problems of phase separation and formation of quenching centers caused by poor compatibility between metal and electron transport host materials in the prior art, and effectively improving the electron transport efficiency of the electron transport layer.

[0074] The N-type electrically conductive dopant used in the electron transport layer may be an organic alkali metal / alkaline earth metal nitrate, carbonate, phosphate or quinoline salt, such as lithium carbonate, lithium quinolate (Liq), lithium azide, rubidium carbonate, silver nitrate, barium nitrate, magnesium nitrate, zinc nitrate, cesium nitrate, cesium carbonate, cesium fluoride, cesium azide, etc. Among them, lithium quinoline is particularly preferred as the N-type electrically conductive dopant.

[0075] In one embodiment, the content of the N-type electrically conductive dopant is greater than 0 wt % to 50 wt % based on the weight of the electron transport layer.

[0076] In one embodiment, the organic layer comprising the phenylbiphenylpyrimidine compound having the structure of formula (I) is a stack of an electron transport layer and a hole blocking layer, wherein the hole blocking layer has a thickness of greater than 0 nm to 5 nm.

[0077] In another specific embodiment, the hole transport layer of the stacked organic layer uses a phenylbiphenylpyrimidine compound having a structure of formula (I) as a single material, and the electron transport layer of the stacked organic layer uses a phenylbiphenylpyrimidine compound having a structure of formula (I) combined with an N-type electrical conductive dopant.

[0078] The structure of the organic electroluminescent device of the present invention will be described with reference to the drawings.

[0079] Figure 11 is a cross-sectional schematic diagram of a specific embodiment of an organic electroluminescent device of the present invention. The organic electroluminescent device 100 comprises 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 manufactured by sequentially depositing the above layers.

[0080] Figure 2 2 is a cross-sectional schematic diagram of another specific embodiment of the organic electroluminescent device of the present invention. The organic electroluminescent device 200 comprises a substrate 210, an anode 220, a hole injection layer 230, a hole transport layer 240, an electron blocking layer 245, a light emitting layer 250, an electron transport layer 260, an electron injection layer 270 and a cathode 280, Figure 1 The difference is that the electron blocking layer 245 is disposed between the hole transport layer 240 and the light emitting layer 250 .

[0081] Figure 3 3 is a cross-sectional schematic diagram of another specific embodiment of the organic electroluminescent device of the present invention. The organic electroluminescent device 300 comprises a substrate 310, an anode 320, a hole injection layer 330, a hole transport layer 340, an electron blocking layer 345, a light-emitting layer 350, a hole blocking layer 355, an electron transport layer 360, an electron injection layer 370 and a cathode 380, Figure 2 The difference is that the hole blocking layer 355 is disposed between the light emitting layer and the electron transporting layer 360 .

[0082] Can rely on Figures 1 to 3 The reverse structure of the device shown is used to manufacture an organic electroluminescent device. One or more layers can be added or removed in the reverse structure according to the needs.

[0083] The materials of the hole injection layer, hole transport layer, electron blocking layer, hole blocking layer, electron blocking layer, and electron injection layer can be selected from commonly used materials. For example, the electron transport material forming the electron transport layer is different from the material of the light-emitting layer, and it has hole transport properties, thereby facilitating the migration of holes in the electron transport layer and preventing carrier accumulation caused by the dissociation energy difference between the light-emitting layer and the electron transport layer.

[0084] The phenyl biphenyl pyrimidine compound of the formula (I) of the present invention is used for an electron transport layer or a hole blocking layer. T ), extremely low highest occupied molecular orbital (HOMO) energy level and good carrier mobility make it difficult for holes in the light-emitting layer to be lost, and at the same time, electrons are effectively transferred to the light-emitting layer, which helps to balance the density of electrons and holes in the light-emitting layer, increase the luminous efficiency and driving stability.

[0085] In addition, US 5844363 discloses a flexible transparent substrate combined with an anode, and the entire contents thereof are hereby incorporated by reference in this invention. As exemplified in US20030230980, a p-type doped hole transport layer is doped with F4-TCNQ in m-MTDATA at a molar ratio of 50:1, and the entire contents thereof are hereby incorporated by reference in this invention. As exemplified in US 20030230980, an n-type doped electron transport layer is doped with lithium in BPhen at a molar ratio of 1:1, and the entire contents thereof are hereby incorporated by reference in this invention. As exemplified in US 5703436 and US 5707745, the entire contents of a cathode are hereby incorporated by reference in this invention, and the cathode has a metal thin layer, such as magnesium / silver (Mg:Ag), and a transparent conductive layer (ITO Layer) deposited by sputtering covering the metal thin layer. The application and principle of each barrier layer disclosed in US 6097147 and US 20030230980 are hereby incorporated by reference in this invention. The injection layer exemplified in US20040174116 and the protective layer described in the same patent are incorporated herein by reference in their entirety.

[0086] Structures and materials not specifically described may also be applied to the present invention, such as organic electroluminescent devices including polymer materials (PLEDs) disclosed in US 5247190, the entire contents of which are incorporated herein by reference. Furthermore, organic electroluminescent devices having a single organic layer or organic electroluminescent devices formed by stacking as disclosed in US 5707745, the entire contents of which are incorporated herein by reference.

[0087] Unless otherwise specified, any layer in different embodiments may be deposited and formed using any appropriate method. For organic layers, preferred methods include thermal evaporation and inkjet printing as disclosed in US 6013982 and US 6087196, the entire contents of which are incorporated herein by reference; organic vapor phase deposition (OVPD) disclosed in US 6337102, the entire contents of which are incorporated herein by reference; and organic vapor jet printing deposition (OVJP) disclosed in US 10 / 233470, the entire contents of which are incorporated herein by reference. Other appropriate methods include spin coating and solution-based processes. Solution-based processes are preferably carried out in a nitrogen or inert gas environment. For other layers, preferred methods include thermal evaporation. Preferred patterning methods include processes such as mask deposition followed by cold welding as disclosed in US6294398 and US6468819, and processes integrating inkjet or organic vapor phase inkjet deposition and patterning, all of which are incorporated herein by reference. Of course, other methods may also be used. The materials used for deposition may be adjusted to correspond to the particular deposition method used.

[0088] The phenylbiphenylpyrimidine compound of formula (I) of the present invention can be prepared into an amorphous thin film for use in organic electroluminescent devices by vacuum deposition or spin coating. When the compound is used in any of the above organic layers, it exhibits a long service life and good thermal stability.

[0089] The organic electroluminescent device of the present invention can be applied to a single device, and its structure is an array configuration or a device with positive and negative electrodes in the array XY coordinates. Compared with the known devices, the present invention can significantly improve the service life of the organic electroluminescent device.

[0090] The following examples are used to illustrate the various properties and effects of the present invention. These detailed examples are only used to illustrate the properties of the present invention, and the present invention is not limited to those exemplified by the specific examples.

[0091] Synthesis Example 1: Synthesis of Compound 2-1

[0092]

[0093] 3-Acetylbiphenyl (30 g, 164.6 mmole), 3-bromobenzaldehyde (29.01 g, 156.79 mmole) and 600 ml of ethanol were added into a reaction flask and stirred. Sodium tert-butoxide (22.58 g, 235.19 mmole) was then added and stirred at room temperature. After the reaction is complete, 200 ml of deionized water is added, stirred and filtered, and the filtered solid is first washed with deionized water and methanol, and then filtered with 100 ml of deionized water and 200 ml of methanol after stirring for 30 minutes. The washing and filtering steps are repeated twice, and the solid is dried to obtain a white solid (about 52 g), namely 1-biphenyl-3-yl-3-(3-bromo-phenyl)-propenone, with a yield of 92.3%.

[0094]

[0095] 1-Biphenyl-3-yl-3-(3-bromo-phenyl)-propenone (52g, 143.15mmole), 4-methylbenzamidine hydrochloride (26.87g, 157.47mmole) and sodium hydroxide (8.56g, 214.73mmole), 78ml of toluene and 260ml of ethanol were placed in a reaction bottle, heated and stirred and maintained at 80°C for reflux. After the reaction was completed, the reaction temperature was lowered to 60°C, 100ml of deionized water was added and stirred for 5 minutes, the water layer was removed, and the organic layer was concentrated until solid precipitated, and then washed with ethyl acetate, filtered and dried to obtain a white solid (about 27.7g) with a yield of 39.6%.

[0096]

[0097] 4-Biphenyl-3-yl-6-(3-bromo-phenyl)-2-p-tolyl-pyrimidine (4.32 g, 12 mmole), 9,9'-spirobifluorene-2-boronic acid (4.78 g, 10 mmole) and potassium carbonate (6.73 g, 35 mmole) were placed in a reaction flask, and 34 ml of toluene, 10 ml of ethanol and 14 ml of deionized water were added. The reaction flask was placed in an oil bath, and nitrogen and a condenser were connected. The mixture was heated and stirred at 80°C. At the same time, tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (0.58 g, 0.5 mmole) was added to the reaction flask. When the reaction is complete and solids are precipitated, the oil bath is removed, the mixture is cooled and filtered, 100 ml of deionized water is added to the filter cake, the mixture is stirred for 10 minutes and filtered again, and 250 ml of tetrahydrofuran is added to the filter cake, the mixture is heated and stirred until completely dissolved, a column containing 20 g of silica is added for chromatography purification, and the mixture is concentrated until a white solid is precipitated. The mixture is then washed with ethyl acetate, filtered and dried to obtain a white solid (about 6.1 g) as the product, with a yield of 85.5%.

[0098] 1H NMR(CDCl3,400MHz),δ8.56(d,2H),8.44(t,1H),8.36(t,1H),8.22(t,1H), 8.14(t,1H),7.98(d,2H),7.90(d,1H),7.86(d,2H),7.73-7.77(m,2H),7.6 9-7.72(m,2H),7.63(t,1H),7.56(t,1H),7.47-7.53(m,3H),7.32-7.45(m, 6H),7.11-7.15(m,3H),7.04(t,1H),6.81(d,2H),6.76(d,1H),2.47(s,3H).

[0099] Synthesis Example 2: Synthesis of Compound 2-2

[0100]

[0101] 3-Acetylbiphenyl (19.6 g, 100 mmole) and 4-bromo-benzaldehyde (18.5 g, 100 mmole) were placed in a 500 ml double-necked round-bottomed reaction bottle, and 200 ml of ethanol and potassium hydroxide (2.8 g, 50 mmole) were added respectively, and stirred at room temperature. After the reaction was complete, the solid was filtered, washed with ethanol and dried to obtain a light yellow solid (about 31.3 g), with a yield of 86%.

[0102]

[0103] 1-Biphenyl-3-yl-3-(4-bromo-phenyl)-propenone (51 g, 140.4 mmole), 4-methylbenzamidine hydrochloride (26.35 g, 154.44 mmole), sodium hydroxide (8.42 g, 210.6 mmole), 77 ml of toluene, and 255 ml of ethanol were placed in a reaction bottle, heated and stirred, and maintained at 80° C. for reflux. After the reaction was completed, the reaction temperature was lowered to 60° C., 100 ml of deionized water was added and stirred for 5 minutes, and then the water layer was removed, and the organic layer was concentrated until solid precipitated, and then washed with ethyl acetate, filtered and dried to obtain a white solid (about 27 g) with a yield of 40.28%.

[0104]

[0105] 4-Biphenyl-3-yl-6-(4-bromo-phenyl)-2-p-tolyl-pyrimidine (4.32 g, 12 mmole), 9,9'-spirobifluorene-2-ylboronic acid (4.78 g, 10 mmole) and potassium carbonate (6.73 g, 35 mmole) were placed in a reaction flask, and 34 ml of toluene, 10 ml of ethanol and 14 ml of deionized water were added. The reaction flask was placed in an oil bath, and nitrogen and a condenser were connected. Then, heating and stirring were started at 80°C. At the same time, tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (0.58 g, 0.5 mmole) was added to the reaction flask. When the reaction is complete and solids are precipitated, the oil bath is removed, the mixture is cooled and filtered, 100 ml of deionized water is added to the filter cake, the mixture is stirred for 10 minutes and filtered again, and 250 ml of tetrahydrofuran is added to the filter cake, the mixture is heated and stirred until completely dissolved, a column containing 20 g of silica is added for chromatography purification, and the mixture is concentrated until a white solid is precipitated, which is then washed with ethyl acetate, filtered and dried to obtain a white solid (about 6.3 g) with a yield of 88.3%.

[0106] 1 H NMR(CDCl3,400MHz),δ8.60(d,2H),8.45(t,1H),8.25(d,2H),8.22(d,1H),7.98(s,1H),7.95(d,1H),7.88(t,3H),7.69-7.76(m,4H ),7.60-7.64(m,3H),7.50(t,2H),7.38-7.43(m,4H),7.33(d,2H),7.13(t,3H),7.03(s,1H),6.81(d,2H),6.75(d,1H),2.45(s,3H).

[0107] Synthesis Example 3: Synthesis of Compound 2-4

[0108]

[0109] 4-Biphenyl-3-yl-6-(4-bromo-phenyl)-2-p-tolyl-pyrimidine (4.32 g, 12 mmole), 9,9'-spirobifluorene-2-ylboronic acid (4.78 g, 10 mmole) and potassium carbonate (6.73 g, 35 mmole) were placed in a reaction flask, and 34 ml of toluene, 10 ml of ethanol and 14 ml of deionized water were added. The reaction flask was placed in an oil bath, and nitrogen and a condenser were connected. The mixture was heated and stirred at 80°C. At the same time, tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (0.58 g, 0.5 mmole) was added to the reaction flask. When the reaction is complete and solids are precipitated, the oil bath is removed, the mixture is cooled and filtered, 100 ml of deionized water is added to the filter cake, the mixture is stirred for 10 minutes and filtered again, 250 ml of tetrahydrofuran is added to the filter cake, the mixture is heated and stirred until completely dissolved, a column containing 20 g of silica is added for chromatography purification, and the mixture is concentrated until a white solid is precipitated. The mixture is then washed with ethyl acetate, filtered and dried to obtain a white solid (about 5.9 g) with a yield of 82.69%.

[0110] 1 H NMR(CDCl3,400MHz),δ8.64(d,2H),8.50(t,1H),8.42(d,2H),8.18(t,1H),8.14(d,1H),8.09(s,1H),7.95(d,1H),7.85-7.89(m,4H),7.7 8(t,1H),7.72-7.74(m,2H),7.65(t,1H),7.53(t,2H),7.35-7.44(m, 7H),7.13-7.17(m,3H),6.85(d,1H),6.77-6.82(m,3H),2.47(s,3H).

[0111] Synthesis Example 4: Synthesis of Compound 3-4

[0112]

[0113] 4-([1,1'-biphenyl]-3-yl)-6-(3-bromophenyl)-2-(pyridin-3-yl)pyrimidine (10 g, 21.53 mmole) and 9,9'-spirobi[fluoren]-2-ylboronic acid (8.14 g, 22.61 mmole) were placed in a reaction tank, and 120 ml of toluene was added. Potassium carbonate (10.41 g, 75.37 mmole) was dissolved in 70 ml of deionized water and added to the reaction tank. At the same time, tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (1.24 g, 1.077 mmole) and 30 ml of ethanol were added. The mixture was heated and stirred until 80°C and reacted overnight. After the reaction is completed, 300 ml of deionized water is added. After stirring for 30 minutes, stirring is stopped and the mixture is allowed to stand for stratification and extraction is performed. The filtrate after extraction is added to a column filled with silica gel for chromatography purification. After concentration to a thick state, 300 ml of hexane is added to enhance precipitation. The organic layers are combined and the solid is filtered to obtain a milky white solid (about 7 g) as the product.

[0114] 1 H NMR(CDCl3,400MHz),δ9.90(d,1H),8.96(td,1H),8.76(dd,1H),8.47(s,1H) ,8.35(s,1H),8.21(d,1H),8.14(d,1H),8.03(s,1H),7.99(d,1H),7.91(d,1 H),7.86(d,2H),7.74-7.79(m,2H),7.71(d,2H),7.64(t,1H),7.58(d,1H),7 .36-7.54(m,8H),7.12-7.16(m,3H),7.04(d,1H),6.82(d,2H),6.77(d,1H).

[0115] Synthesis Example 5: Synthesis of Compound 3-6

[0116]

[0117] 4-([1,1'-biphenyl]-3-yl)-6-(3-bromophenyl)-2-(pyridin-3-yl)pyrimidine (10 g, 21.53 mmole) and 9,9'-spirobifluorene-2-ylboronic acid (9.41 g, 22.61 mmole) were placed in a reaction tank, and 120 ml of toluene was added. Potassium carbonate (10.41 g, 75.37 mmole) was dissolved in 70 ml of deionized water and added to the reaction tank. At the same time, tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (1.24 g, 1.077 mmole) and 30 ml of ethanol were added. The heating and stirring were turned on, and the mixture was heated to 80°C and reacted overnight. After the reaction is completed, 300 ml of deionized water is added. After stirring for 30 minutes, the stirring is stopped and the mixture is allowed to stand for stratification and extraction is performed. The filtrate after extraction is added to a column filled with silica gel for chromatography purification. After concentration to a thick state, 300 ml of hexane is added to strengthen precipitation. The organic layers are combined and the solid is filtered to obtain a milky white solid (about 6 g).

[0118] 1 H NMR(CDCl3,400MHz),δ9.97(d,1H),8.97(td,1H),8.77(dd,1H),8.55(s,1H),8.52(t,1H),8.24-8.29(m,2H),8.15(s,2H),7.97(d,1H),7.90(d,2 H),7.84(d,1H),7.79(d,1H),7.72(d,2H),7.64-7.69(m,2H),7.52(t,2H ),7.40-7.48(m,5H),7.17(t,3H),6.88(d,1H),6.84(d,2H),6.80(d,1H).

[0119] Synthesis Example 6: Synthesis of Compound 3-7

[0120]

[0121] 4-[1,1'-biphenyl]-3-yl-6-(4-bromophenyl)-2-(pyridine-3-yl)pyrimidine)(9.28 g, 20 mmole), 9,9'-spirobifluorene-3-yl boronic acid)(9.3 g, 24 mmole), tetrakis(triphenylphosphine)palladium(Pd(PPh3)4)(1.16 g, 1 mmole) and potassium carbonate (5.5 g, 40 mmole) were placed in a 1000 ml double-necked round-bottomed reaction flask, and 320 ml of toluene, 220 ml of ethanol and 100 ml of deionized water were added respectively. The reaction flask was placed in an oil bath, and nitrogen and a condenser were connected, and then heating and stirring were started at 80°C. When the reaction was complete and solids were precipitated, the oil bath was removed, the mixture was cooled and filtered, and the filtered solids were rinsed with 300 ml of acetone and dried to obtain a white solid (about 8.9 g) with a yield of 64%.

[0122] 1 H NMR(CDCl3,400MHz)δ9.96(s,1H),8.99(td,1H),8.77(dd,1H),8.52(t,1H), 8.42(d,2H),8.27(d,1H),8.17(s,1H),8.14(d,1H),7.96(d,1H),7.88(d,4H ),7.80(d,1H),7.73(dd,2H),7.67(t,1H),7.53(t,2H),7.45-7.51(m,1H),7 .38-7.44(m,5H),7.13-7.16(m,3H),6.86(s,1H),6.81(d,2H),6.78(d,1H).

[0123] Synthesis Example 7: Synthesis of Compound 3-8

[0124]

[0125] 4-([1,1'-biphenyl]-3-yl)-6-(4-bromophenyl)-2-(pyridin-3-yl)pyrimidine (9.28 g, 20 mmole), 9-phenanthrene-9-yl-9-boronic acid (5.3 g, 24 mmole), tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (1.16 g, 1 mmole) and potassium carbonate (5.5 g, 40 mmole) were placed in a 1000 ml double-necked round-bottom reaction bottle, and 320 ml of toluene, 220 ml of ethanol and 100 ml of deionized water were added respectively. The reaction bottle was placed in an oil bath, and nitrogen and a condenser were connected, and then heating and stirring were started at 80°C. When the reaction was complete and solids were precipitated, the oil bath was removed, the mixture was cooled, filtered and dried to obtain a gray-black solid (about 5.4 g) with a yield of 48%.

[0126] 1 H NMR(CDCl3,400MHz)δ9.98(d,1H),9.01(td,1H),8.82(d,1H),8.78(d,1H),8.76(d,1H),8.55(s,1H),8.46(d,2H),8.30(dd,1H),8.23(s,1H),7.9 0(d,1H),7.95(d,1H),7.77-7.82(m,3H),7.65-7.64(m,3H),7.66-7.78( m,7H),7.58(t,1H),7.52(t,2H),7.50(d,1H),7.49(d,1H),7.44(t,1H).

[0127] Synthesis Example 8: Synthesis of Compound 1-2

[0128]

[0129] 1-Biphenyl-3-yl-3-(4-bromo-phenyl)-propenone (36.7 g, 101.14 mmole), 4-Fluorobenzamidine hydrochloride (17.66 g, 101.14 mmole), sodium hydroxide (5.78 g, 144.5 mmole) and 200 ml of ethanol were placed in a reaction bottle, heated to 75°C and reacted overnight. After the reaction was completed, it was filtered to obtain a milky white solid (about 23 g).

[0130]

[0131] 4-([1,1'-biphenyl]-3-yl)-6-(4-bromophenyl)-2-(4-fluorophenyl)pyrimidine (10 g, 20.77 mmole) and 9,9'-spirobi[fluoren]-2-ylboronic acid (7.85 g, 21.8 mmole) were placed in a reaction tank, and 120 ml of toluene was added. Potassium carbonate (10 g, 72.7 mmole) was dissolved in 70 ml of deionized water and added to the reaction tank. At the same time, tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) (1.2 g, 1.039 mmole) and 30 ml of ethanol were added. The heating and stirring were turned on, and the mixture was heated to 80°C and reacted overnight. After the reaction is completed, 300 ml of deionized water is added. After stirring for 30 minutes, the stirring is stopped and the mixture is allowed to stand for stratification. Extraction is performed, and a column filled with silica gel is added for chromatography purification. After concentration to a thick state, 300 ml of hexane is added to enhance precipitation. The solid is filtered to obtain a milky white solid (about 6 g).

[0132] 1 H NMR(CDCl3,400MHz)δ8.69-8.72(m,2H),8.44(t,1H),8.23(d,2H),8.20(d,1H),8.00(s,1H),7.96(d,1H),7.87-7.90(m,3H),7.75(d,1H) ),7.69-7.73(m,3H),7.61-7.64(m,3H),7.50(t,2H),7.38-7.43(m,4H),7.19(t,2H),7.14(t,3H),7.04(d,1H),6.81(d,2H),6.75(d,1H)

[0133] The physical property values ​​of the above materials and compound EET09 are shown in Table 2, wherein the compound EET09 is as described in JP2011003793A.

[0134] The measuring methods of each physical property value are as follows.

[0135] (1) Thermal cracking temperature (T d )

[0136] The thermal decomposition properties of the obtained compounds were measured using a thermogravimetric analyzer (Perkin Elmer, TGA 8000) at normal pressure and nitrogen atmosphere at a programmed heating rate of 20°C / min. The temperature at which the weight decreased to 95% of the initial weight was the thermal decomposition temperature (T d ).

[0137] (2) Glass transition temperature (T g )

[0138] The obtained compound was measured using a differential scanning calorimeter (DSC; Perkin Elmer, DSC 8000) at a programmed temperature rate of 20°C / min.

[0139] (3) Energy level of the highest occupied molecular orbital (HOMO)

[0140] In addition, the compound was made into a thin film state, and its ionization potential value was measured using a photoelectron spectrophotometer (Riken Keiki, Surface Analyzer) in the atmosphere, and the value was further converted into the HOMO energy level value.

[0141] (4) Energy level of the lowest unoccupied molecular orbital (LUMO)

[0142] The thin film of the above compound was measured with a UV / VIS spectrophotometer (Perkin Elmer, Lambda 20) for the boundary value of its absorption wavelength, which was converted into an energy gap value, and the energy gap value was added to the numerical value of the HOMO energy level to obtain the LUMO energy level.

[0143] (5) Triplet energy value (E T )

[0144] The luminescence spectrum was measured at 77 K using a fluorescence spectrometer (Perkin Elmer, LS 55) and then calculated to obtain E T .

[0145] Table 2

[0146]

[0147] Preparation Example 1-1: Fabrication of an organic electroluminescent device

[0148] Before the substrate is loaded into the evaporation system, it is first cleaned with solvent and UV ozone to degrease the substrate. Afterwards, the substrate is transferred to the vacuum deposition chamber to deposit all layers on top of the substrate. The heated evaporation boat is heated for about 10 -6 The vacuum degree of the support is deposited in sequence Figure 2 The layers shown are:

[0149] a) a hole injection layer, 20 nm thick, comprising HTM doped with 6% by weight of a p-type electrically conductive dopant, wherein the p-type electrically conductive dopant was purchased from Shanghai Hanfeng Chemical Co., Ltd., and the HTM was purchased from Merck & Co., Inc.;

[0150] b) hole transport layer, thickness 150 nm, HTM;

[0151] c) Exciton blocking layer, thickness 10 nm, HT (manufactured by Yulai Optoelectronics);

[0152] d) a light-emitting layer with a thickness of 25 nm, comprising EBH doped with 4% by weight of BD, wherein BD and EBH are prepared by Yulei Optoelectronics;

[0153] e) an electron transport layer, 20 nm thick, comprising compound 2-4 and doped lithium quinoline (Liq), in a weight ratio of 5:5;

[0154] f) electron injection layer, thickness 1.5 nm, Liq; and

[0155] g) Cathode, about 180 nm thick, comprising aluminum (A1).

[0156] The device structure may be represented as: ITO / HTM: p-type electrically conductive dopant (20 nanometers) / HTM (150 nanometers) / HT (10 nanometers) / EBH: BD (25 nanometers) / Compound 2-4: Liq (20 nanometers) / Liq (1.5 nanometers) / Al (180 nanometers).

[0157]

[0158] After the above layers are deposited, the device is transferred from the deposition chamber to a drying oven and then packaged with UV curable epoxy resin and a glass cover containing a moisture absorbent. The organic electroluminescent device has a light emitting area of ​​9 square millimeters.

[0159] Preparation Examples 1-2 to 1-5: Fabrication of Organic Electroluminescent Devices

[0160] Except that compound 2-4 of the electron transport layer in Preparation Example 1-1 was replaced by compounds 3-4, 3-7, 3-8 and 3-6 respectively, Examples 1-2, 1-3, 1-4 and 1-5 were prepared according to the layer structure of Preparation Example 1-1.

[0161] Preparation Examples 1-1A to 1-1C: Fabrication of Organic Electroluminescent Devices

[0162] Except that the weight ratios of compound 2-4 and doped lithium quinoline (Liq) in the electron transport layer in Preparation Example 1-1 were changed to 1:0, 7:3 and 3:7 respectively, Preparation Example 1-1A, Preparation Example 1-1B and Preparation Example 1-1C were prepared according to the layer structure of Preparation Example 1-1.

[0163] Preparation Examples 1-3A to 1-3C: Fabrication of Organic Electroluminescent Devices

[0164] Example 1-3A, Example 1-3B and Example 1-3C were prepared in the same manner as the layer structure of Example 1-3, except that the weight ratios of compound 3-7 and doped lithium quinoline (Liq) in the electron transport layer in Example 1-3 were changed to 1:0, 7:3 and 3:7, respectively.

[0165] Preparation Example 1-4A: Fabrication of an organic electroluminescent device

[0166] Example 1-4A was prepared in the same manner as the layer structure of Example 1-4, except that the weight ratio of compound 3-8 and doped lithium quinoline (Liq) in the electron transport layer in Example 1-4 was changed to 7:3.

[0167] Preparation Example 1-5A: Fabrication of an organic electroluminescent device

[0168] Example 1-5A was prepared in the same manner as the layer structure of Example 1-5, except that the weight ratio of compound 3-6 and doped lithium quinoline (Liq) in the electron transport layer in Example 1-5 was changed to 7:3.

[0169] Comparative Preparation Example 1: Fabrication of an Organic Electroluminescent Device

[0170] An organic electroluminescent device was manufactured to have a layer structure similar to that of Preparation Example 1-1, except that the compound 2-4 of the electron transport layer in Preparation Example 1-1 was replaced by the compound EET09, wherein the compound EET09 is as described in JP2011003793A.

[0171] Comparative Preparation Example 2: Fabrication of an Organic Electroluminescent Device

[0172] An organic electroluminescent device was manufactured to have a layer structure similar to that of Preparation Example 1-1, except that the compound 2-4 of the electron transport layer in Preparation Example 1-1 was replaced by the compound ETM801, wherein the compound ETM801 was described in JP 6367389 and prepared by Yulei Optoelectronics.

[0173] Test Examples 1 to 4:

[0174] The electroluminescent properties of the organic electroluminescent devices prepared in the above-mentioned preparation examples 1-1 to 1-4 were measured at room temperature using a constant current source (KEITHLEY 2400 Source Meter, made by Keithley Instruments, Inc., Cleveland, Ohio) and a photometer (PHOTO RESEARCH SpectraScan PR 650, made by Photo Research, Inc., Chatsworth, Calif.). The driving voltage (V d ), luminous efficiency and LT95 values ​​at a current density of 50 J are listed in Table 3, wherein the LT95 value is defined as the time consumed for the brightness level to drop to 95% of the initial brightness, which is used as a measure for evaluating the service life or stability of the organic electroluminescent device.

[0175] Comparative Test Example 1:

[0176] The electroluminescent properties of the organic electroluminescent device prepared in Comparative Preparation Example 1 were measured in the same manner as in Experimental Example 1.

[0177] Test Example 5:

[0178] The organic electroluminescent devices prepared in the above-mentioned preparation examples 1-3 were measured at a current density of 10 mA / cm2 using a constant current source (KEITHLEY 2400 Source Meter, made by Keithley Instruments, Inc., Cleveland, Ohio) and a photometer (PHOTO RESEARCH SpectraScan PR 650, made by Photo Research, Inc., Chatsworth, Calif.). 2 ) to measure its electroluminescent properties, including: driving voltage (V d ), luminous efficiency, color coordinates CIE (x, y) and blue index values, and are recorded in Table 4. The blue index is the ratio of luminous efficiency to color coordinate y. The higher the blue index, the better the efficiency of the device.

[0179] Test Example 6:

[0180] The electroluminescent properties of the organic electroluminescent devices prepared in Preparation Examples 1-3 were measured using the same measurement method as in Experimental Example 5, except that the current density was changed to 50 mA / cm2. 2 ).

[0181] Comparative Test Examples 2 and 3:

[0182] The organic electroluminescent device prepared in Comparative Preparation Example 2 was subjected to the measurement method of Experimental Example 5 at current densities of 10 and 50 mA / cm2, respectively. 2 ) to measure its electroluminescent properties.

[0183] Test Examples 7 to 18:

[0184] For different doping ratios of the electron transport layer, the measured values ​​of the organic electroluminescent devices of Preparation Examples 1-1, 1-3, 1-4 and 1-6 are listed and recorded in Table 5.

[0185] Table 3

[0186]

[0187]

[0188] Table 4

[0189]

[0190] Table 5

[0191]

[0192] Preparation Example 2-1: Fabrication of an organic electroluminescent device

[0193] Before the substrate is loaded into the evaporation system, it is first cleaned with solvent and UV ozone to degrease the substrate. Afterwards, the substrate is transferred to the vacuum deposition chamber to deposit all layers on top of the substrate. The heated evaporation boat is heated for about 10 -6 The vacuum degree of the support is deposited in sequence Figure 3 The layers shown are:

[0194] a) a hole injection layer, 20 nm thick, comprising HTM doped with 6% by weight of a p-type electrically conductive dopant, wherein the p-type electrically conductive dopant was purchased from Shanghai Hanfeng Chemical Co., Ltd., and the HTM was purchased from Merck & Co., Inc.;

[0195] b) hole transport layer, thickness 150 nm, HTM;

[0196] c) Exciton blocking layer, thickness 10 nm, HT (manufactured by Yulai Optoelectronics);

[0197] d) a light-emitting layer with a thickness of 25 nm, comprising EBH doped with 4% by weight of BD, wherein BD and EBH are prepared by Yulei Optoelectronics;

[0198] e) hole blocking layer, thickness 5 nm, compound 2-4;

[0199] f) an electron transport layer, 20 nm thick, comprising compound 2-4 and doped lithium quinoline (Liq), in a weight ratio of 5:5;

[0200] g) electron injection layer, thickness 1.5 nm, Liq; and

[0201] h) A cathode having a thickness of about 180 nm and comprising aluminum (A1).

[0202] The device structure can be represented as: ITO / HTM: p-type electrically conductive dopant (20 nanometers) / HTM (150 nanometers) / HT (10 nanometers) / EBH: BD (25 nanometers) / Compound 2-4 (5 nanometers) / Compound 2-4: Liq (20 nanometers) / Liq (1.5 nanometers) / Al (180 nanometers).

[0203] After the above layers are deposited, the device is transferred from the deposition chamber to a drying oven and then packaged with UV curable epoxy resin and a glass cover containing a moisture absorbent. The organic electroluminescent device has a light emitting area of ​​9 square millimeters.

[0204] Preparation Example 2-2: Fabrication of an organic electroluminescent device

[0205] Example 2-2 was prepared in the same manner as the layer structure of Example 1-1, except that the compound 2-4 of the hole blocking layer and the electron transport layer in Example 2-1 was replaced by the compound 3-7.

[0206] Preparation Examples 2-1A to 2-1B: Fabrication of Organic Electroluminescent Devices

[0207] Example 2-1A and Example 2-1B were prepared in the same manner as the layer structure of Example 2-1, except that the weight ratios of Compound 2-4 and doped lithium quinoline (Liq) in the electron transport layer in Example 2-1 were changed to 7:3 and 3:7, respectively.

[0208] Preparation Examples 2-2A to 2-2B: Fabrication of Organic Electroluminescent Devices

[0209] Example 2-2A and Example 2-2B were prepared in the same manner as in Example 2-2, except that the weight ratios of compound 3-7 and doped lithium quinoline (Liq) in the electron transport layer in Example 2-2 were changed to 7:3 and 3:7, respectively.

[0210] Comparative Preparation Example 3: Fabrication of an Organic Electroluminescent Device

[0211] An organic electroluminescent device was manufactured to have a layer structure similar to that of Preparation Example 2-1, except that the compound 2-4 of the hole blocking layer and the electron transport layer in Preparation Example 2-1 were replaced by compound EET09, respectively.

[0212] Test Examples 19 to 24:

[0213] The electroluminescent properties of the organic electroluminescent devices prepared in the above-mentioned Preparation Examples 2-1 and 2-2 were measured using the same measurement method as in Experimental Example 7 and recorded in Table 6.

[0214] Comparative Test Example 4:

[0215] The electroluminescent properties of the organic electroluminescent device prepared in Comparative Preparation Example 4 were measured using the same measurement method as in Experimental Example 19 and are recorded in Table 6.

[0216] Table 6

[0217]

[0218] As described above, it can be seen that the organic electroluminescent device comprising the phenylbiphenylpyrimidine compound having the structure of formula (I) of the present invention exhibits good heat resistance and significantly improves its service life. Therefore, the organic electroluminescent device of the present invention can meet various application requirements and has extremely high technical value.

[0219] The above embodiments are merely illustrative and are not intended to limit the present invention. Any person skilled in the art may modify and alter the above embodiments without violating the spirit and scope of the present invention. Therefore, the scope of protection of the present invention is defined by the claims attached hereto, and any claims that do not affect the effects and implementation purposes of the present invention shall be included in the disclosed technical content.

Claims

1. A phenylbiphenylpyrimidine compound having a structure of formula (1-5) or formula (1-6): in, X1 is selected from the group consisting of unsubstituted pyridyl and C 1-4 One of the group consisting of alkyl-substituted phenyl; A1 is selected from one of the following groups: and 2. The phenylbiphenylpyrimidine compound of formula (I) as claimed in claim 1, which is selected from the group consisting of:

3. An organic electroluminescent device, comprising: cathode; an anode; and The organic layer is located between the cathode and the anode, and the organic layer comprises the phenylbiphenylpyrimidine compound with the structure of formula (I) as claimed in claim 1.

4. The organic electroluminescent device according to claim 3, characterized in that: The organic layer is an electron transport layer, and its thickness is 20 nm to 30 nm.

5. The organic electroluminescent device according to claim 4, characterized in that: The electron transport layer further comprises an N-type electrical conductive dopant, and the content of the N-type electrical conductive dopant is greater than 0 wt % to 50 wt %, and the N-type electrical conductive dopant is lithium quinoline.

6. The organic electroluminescent device according to claim 4, characterized in that: The organic layer further includes a hole blocking layer, and the thickness of the hole blocking layer is greater than 0 nanometers to 5 nanometers.

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