TWI710621B - Naphthyl-substituted phenylpyrimidines compounds and organic electroluminescent devices using the same - Google Patents

Abstract

The present invention provides naphthyl-substituted phenylpyrimidines compounds of formula (I) and an organic electroluminescent device using the same: wherein Ar, R, m and n are as defined in the description.

Description

Phenylpyrimidine compound substituted by naphthyl group 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.

Recently, organic electroluminescent elements (OLEDs) are commercially attractive for high-luminance and high-density pixel displays due to their advantages of long life, high efficiency, low driving voltage, wide color gamut, and low cost. To meet the application of the organic electroluminescence element, it is particularly focused on the development of its novel organic materials.

A typical OLED has at least one organic emissive layer sandwiched between the anode and the cathode. When a current is applied, the anode injects holes and the cathode injects electrons into the one or more organic light-emitting 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 is a confined electron-hole pair with an excited energy state. Through the luminescence mechanism, the exciton relaxes and emits Light. In order to improve the charge transport ability and luminous efficiency of these devices, combined with the light-emitting layer One or more additional layers, such as electron transport layer and/or hole transport layer, or electron blocking layer and/or hole blocking layer. In the literature, it has been fully demonstrated that the host material is blended with another guest material to improve device performance and adjust chromaticity. Several OLED materials and device configurations are described in patents such as US4769292, US5844363, US5707745, US6596415, and US6465115, which are incorporated herein by reference in their entirety.

The reasons for manufacturing an OLED with a multilayer thin film structure include stabilizing the interface between the electrodes and the organic layer and the combination of organic materials. In organic materials, the mobility of electrons and holes is obviously different. If a commensurate hole transport and electron transport layer is used, holes and electrons can be effectively transported to the light-emitting layer, so that the light-emitting layer The density of electrons and holes is balanced to increase luminous efficiency. Appropriate combination of the above-mentioned organic layer can improve the efficiency and lifetime of the device.

In order to increase the life of the device, the prior art uses quinazoline material in the main part of the light-emitting layer. However, the quinazoline material is only suitable for red light color organic electroluminescent devices because of its small triplet energy gap. To meet the needs of actual display applications, especially for automotive displays and lighting, the organic materials used in organic electroluminescent devices must have good thermal stability to maintain the performance and service life requirements of the devices.

Therefore, there is an urgent need for an organic material with good heat resistance to significantly improve the life of the organic electroluminescent device, and the triplet energy gap of the organic material can be applied to any light color organic electroluminescent device, so it can Meet the needs of diverse applications.

The purpose of the present invention is to provide a material for organic electroluminescent devices with long life, high carrier mobility and good heat resistance.

The present invention provides a naphthyl substituted phenylpyrimidine compound with the structure of formula (I):

Wherein, Ar represents substituted or unsubstituted C _3-30 heteroaryl containing heteroatoms selected from the group consisting of N, O, and S; R represents hydrogen, deuterium, tritium, substituted or unsubstituted A substituted C _6-30 aryl group, a substituted or unsubstituted C _5-30 heteroaryl group containing a different atom selected from the group consisting of N, O, and S, and Ar and R are different; m represents an integer of 1, 2, or 3; and n represents an integer of 0, 1, or 2.

In some embodiments of the present invention, the compound of formula (I) is represented by formula (I-1) or formula (I-2):

In some embodiments of the present invention, the compound of formula (I) is represented by formula (I-3):

In some embodiments of the present invention, the compound of formula (I) is represented by formula (I-4) or formula (I-5):

In some embodiments of the present invention, the Ar is a C _3-30 heteroaryl group containing a nitrogen atom substituted by a C _1-4 alkyl group or a C _6-18 aryl group.

In some embodiments of the present invention, the C _3-30 heteroaryl group is triazinyl or benzimidazolyl.

其中，A₁、A₂各獨立表示氫、未經取代之C_6-18芳基或未經取代之C_1-4烷基；且*為Ar表示的基團與式(I)結構的鍵結位置。 In other embodiments of the present invention, the triazinyl group is substituted with at least one C _6-18 aryl group; the benzimidazole group is selected from the structure of formula (A-1) or formula (A-2) :

Wherein, A ₁ and A ₂ each independently represent hydrogen, an unsubstituted C _6-18 aryl group or an unsubstituted C _1-4 alkyl group; and * is the bond between the group represented by Ar and the structure of formula (I) Knot position.

In some embodiments of the present invention, the R is hydrogen, phenyl or naphthyl.

In some embodiments of the present invention, the compound of formula (I) is one of compound (5) and compound (13):

The present invention further provides 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 naphthyl-substituted structure of the present invention with formula (I) The phenyl pyrimidine compound.

In some embodiments of the present invention, the organic layer is an electron transport layer, and its thickness is between 15 nanometers and 30 nanometers.

In some embodiments of the present invention, the electron transport layer further includes an N-type electrically conductive dopant, and the content of the N-type electrically conductive dopant is 30% to 70% by weight, wherein the N-type electrically conductive dopant The electrically conductive dopant is lithium quinolate.

According to the present invention, since the naphthyl-substituted phenylpyrimidine compound with the structure of formula (I) of the present invention has a suitable triplet energy gap, it can be applied to any light color organic electroluminescent device, and by the present invention The naphthyl substituted phenylpyrimidine compound with the structure of formula (I) can also effectively improve the life of the organic electroluminescent device, increase the carrier mobility and provide the benefits of good 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 by referring to the drawings illustratively: Fig. 1 is a schematic cross-sectional view of one embodiment of the organic electroluminescent device of the present invention; Fig. 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.

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 Alkylsilyl group, tri-C _6-30 arylsilyl group, di-C _1-30 alkyl group, C _6-30 arylsilyl group, C _1-30 alkyl group, di-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 aryl or (extended) aryl. The aryl refers to a monocyclic ring or condensed ring derived from aromatic hydrocarbons, and includes phenyl, biphenyl, triphenyl, naphthalene Group, binaphthyl, phenylnaphthyl, naphthylphenyl, stilbene, phenyl stilbene, benzo stilbene, dibenzo stilbene, phenanthryl, phenylphenanthryl, anthracenyl, indenyl, biphenyl Triphenylene, pyrenyl, fused tetraphenyl, acyl, quinacyl, 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 heteroaryl, and this heteroaryl refers to a ring backbone 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 naphthyl substituted phenylpyrimidine compound having the structure of formula (I) is selected from Table 1, but is not limited thereto.

The naphthyl-substituted phenylpyrimidine compound with the structure of formula (I) of the present invention has a glass transition temperature between 130 and 150°C and can withstand the long-term high temperature inside the car, so it is suitable for car display or lighting source The organic electric excitation light element.

The present invention further provides 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 naphthyl-substituted structure of the present invention with formula (I) The phenyl pyrimidine compound.

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 naphthyl-substituted phenylpyrimidine compound with the structure of formula (I) of the present invention is preferably an electron transport layer, and its thickness is between 15 nm and 30 nm M; wherein, the electron transport layer can be a naphthyl-substituted phenylpyrimidine compound with a structure of formula (I) as a single material, or a naphthyl-substituted phenylpyrimidine compound with a structure of formula (I) and Electrically conductive dopants are used in combination.

In other embodiments, the thickness of the electron transport layer of the present invention can be 16, 17, 18, 19, 20, 21, 22, 23, or 24 nanometers, and is not limited thereto.

In another embodiment, the electron transport layer further comprises an N-type electrically conductive dopant, wherein the N-type electrically conductive dopant is the same as the naphthyl substituted benzene with the structure of formula (I) of the present invention The base pyrimidine compound produces chelation, which makes it easier to inject electrons from the cathode into the electron transport layer, and solves the phase separation and formation caused by the poor compatibility between the metal and the electron transport host material in the prior art. The problem of quenching the center effectively improves the electron transport efficiency of the electron transport layer.

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 quinolate.

In a specific embodiment, the content of the N-type electrically conductive dopant is 30% to 70% by weight based on the weight of the electron transport layer.

In other embodiments, the content of the N-type electrically conductive dopant may be 35, 40, 45, 50, 55, or 60% by weight, and is not limited thereto.

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, an anode 320, a hole injection layer 330, a hole transport layer 340, a light-emitting layer 350, an exciton blocking layer 355, an electron transport layer 360, an electron injection layer 370 and a cathode 380, and a The difference in Figure 1 is that the exciton blocking layer 355 is disposed 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 hole injection layer, hole transport layer, exciton blocking layer, electron blocking layer, and electron injection layer can be made of conventional materials. For example, the electron The electron transport material is different from the material of the light-emitting layer, and it has hole transport properties, which promotes the migration of holes 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.

Naphthyl substituted by the structure (I) of the present invention having the formula phenylpyrimidine compounds for the electron transport layer, due to having a triplet energy (E _T) of approximately 2.4eV and good carrier mobility, the use of light-emitting layer When the phosphorescent material is emitted, the carriers in the light-emitting layer are not easily lost, and at the same time, the carriers are effectively transferred to the light-emitting layer, which helps to balance the density of the electrons and holes in the light-emitting layer and increases the luminous efficiency.

In addition, US5844363 discloses a flexible transparent substrate combined with an anode, the entire content of which is cited in the present invention. As illustrated in US20170005275A1, 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 Liq as an N-type doping material to dope in electrons. In the transmission material (ET3), the entire content is cited in the present invention. The entire contents of the cathode as illustrated in US5703436 and US5707745 are cited in the present invention. The cathode has a thin metal layer, such as magnesium/silver (Mg: Ag), and a transparent conductive layer covering the thin metal layer by sputtering deposition (ITO Layer ). The applications and principles of the barrier layers disclosed in US6097147 and US20030230980 are all cited in the present invention. The entire contents of the injection layer illustrated in US20040174116 and the protective layer illustrated in the same case are cited in the present invention.

Structures and materials not specifically described can also be applied to the present invention. For example, US5247190 discloses organic electroluminescent devices including polymer materials (PLEDs), the entire content of which is cited in the present invention. Furthermore, the organic electroluminescent device with a single organic layer or the organic electroluminescent device stacked as disclosed in US5707745, 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. For the organic layer, the preferred methods include thermal evaporation and spray printing methods as disclosed in US6013982 and US6087196, the entire contents of which are cited in the present invention; organic vapor phase deposition (OVPD) disclosed in US6337102 ), the entire content of which is cited in the present invention; the organic vapor jet printing method (deposition by organic vapor jet printing, OVJP) disclosed in the US patent application US10/233470, the entire content of which is cited in the present 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. 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 US6294398 and US6468819, and the process of integrated spray printing or organic vapor spray deposition and patterning, all of which are cited in the present invention. 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 naphthyl substituted phenylpyrimidine compound with the structure of formula (I) of the present invention can be made into an amorphous thin film applied to organic electroluminescent devices by vacuum deposition or wet coating method. 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 positive and negative poles in the X-Y coordinate of the array. Compared with conventional devices, the present invention is applicable to organic electroluminescent devices of all light colors, and can significantly improve the service life and driving stability of the organic electroluminescent devices.

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 not limited to those exemplified in the specific embodiments.

Synthesis Example 1: Synthesis of Compound 5

Place 4-bromoacetophenone (30.0g, 150.7mmole) and 4-bromobenzaldehyde (27.8g, 150.2mmole) in the reaction tank, fully remove the water and add ethanol (EtOH, 600ml), turn on the stirring, and add hydrogen Sodium oxide (NaOH, 6.0 g, 150 mmole), stirred at room temperature for 16 hours. After the reaction, the solid was collected by filtration, and the filtered solid was washed with water and ethanol to obtain compound A (49.0 g, yield 89%) as a milky white solid.

Put compound A (49g, 133.9mmole), 2-naphthaleneboronic acid (51.4g, 298.9mmole) and tetrakis (triphenylphosphine) palladium (3.2g, 2.8mmole) in the reaction tank, fully remove the water and add toluene (600ml ) And ethanol (100ml), start stirring, add 2.0M potassium carbonate aqueous solution (300ml), and react at 120°C for 16 hours. The temperature of the system was lowered to room temperature, the water layer was removed, the organic layer was concentrated to a solid after removing water with magnesium sulfate, crystallized with toluene and hexane, and filtered to obtain the off-white solid compound B (55.5 g, yield 91%).

Put compound B (55.5g, 120.5mmole), 4-chlorophenylhydrazine hydrochloride (27.6g, 144.6mmole) and ethanol (600ml) in the reaction tank, and mix potassium hydroxide (8.4g, 210mmole) into 200ml The ethanol solution was slowly dropped into the reaction tank and heated to 75°C for 24 hours. The reaction was terminated and cooled to room temperature. The solid was filtered and washed with water and ethanol. The solid was digested and crystallized with toluene and hexane to obtain compound C (49.5 g, yield 69%) as a pale yellow to off-white solid.

Compound C (33.4g, 56.1mmole), double pinacol borate (17.0g, 66.9mmole), palladium bis-dibenzylideneacetone (Pd(dba)2,2.2g,3.9mmole) and 2- Dicyclohexylphosphine-2',6'-dimethoxybiphenyl (S-Phos, 3.2g, 7.8mmole) is placed in the reaction tank, after fully dewatering, add dimethylacetamide (DMAc, 400ml) and Potassium acetate (KOAc, 22.0 g, 224.4mmole), react at 120°C for 24 hours under a nitrogen system. Lower the system temperature to room temperature, pour the reaction into the water layer, stir for 1 hour, filter, rinse the solid with water, ethanol and ethyl acetate, then dissolve it with tetrahydrofuran, pass through diatomaceous earth and silica gel to remove residual metals, and concentrate to a solid Crystallized with tetrahydrofuran and hexane, filtered to obtain compound D (32.3 g, yield 84%) as a white solid.

Compound D (9.0g, 13.1mmole), 2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine (5.1g, 13.1mmole) and tetrakis(triphenyl) Phosphine) palladium (0.76g, 0.66mmole) was placed in the reaction tank, after fully removing the water, toluene (100ml) and ethanol (30ml) were added, stirring was turned on, and 2.0M potassium carbonate aqueous solution (30ml) was added, and reacted at 120°C for 16 hours . Reduce the system temperature to room temperature, filter and collect the solids, dissolve the solids with hot toluene, filter with Celite while it is hot to remove the remaining metals, rinse with hot toluene, concentrate the collected toluene solution to a solid, and then use tetrahydrofuran Digested with hexane to crystallize, and filtered to obtain compound 5 as a white solid (8.0 g, yield 66%).

¹ H NMR (CDCl ₃ , 400MHz) δ 9.14 (s, 1H), 8.95 (d, 2H), 8.83 (dd, 4H), 8.49 (d, 4H), 8.18 (s, 3H), 8.00-7.96 (m , 12H), 7.92 (dd, 2H), 7.86 (dd, 2H), 7.72 (t, 1H), 7.64-7.61 (m, 6H), 7.59-7.52 (m, 4H).

Synthesis Example 2: Synthesis of Compound 6

Compound D (9.0g, 13.1mmole), 2-chloro-4,6-diphenyl-1,3,5-triazine (4.6g, 17.2mmole), 2-dicyclohexylphosphorus-2,4, 6-Triisopropylbiphenyl (XPhos, 0.63g, 1.32mmole) and palladium acetate (0.15g, 0.66mmole) are placed in the reaction tank, after fully dewatering, add toluene (100ml) and ethanol (30ml), start stirring, A 2.0 M potassium carbonate aqueous solution (30 ml) was added and reacted at 120°C for 60 hours. Lower the temperature of the system to room temperature, filter and collect the solids, dissolve the solids with hot toluene, filter with celite while hot to remove the remaining metals, rinse with hot toluene, concentrate the collected toluene solution to solids, and then use tetrahydrofuran Digested with hexane to crystallize, and filtered to obtain compound 6 as a white solid (6.6 g, yield 64%).

¹ H NMR (CDCl ₃ , 400MHz) δ 9.14 (s, 1H), 8.94 (d, 2H), 8.82 (dd, 4H), 8.50 (d, 4H), 8.19 (s, 3H), 8.00-7.92 (m , 8H), 7.90 (dd, 2H), 7.86 (dd, 2H), 7.72 (t, 1H), 7.64-7.60 (m, 6H), 7.57-7.47 (m, 4H).

Synthesis Example 3: Synthesis of Compound 8

Compound C (10.0g, 16.8mmole), [4-(2-phenyl-1H-benzimidazol-1-yl)phenyl]boronic acid (5.97g, 19.0mmole), 2-dicyclohexylphosphorus-2 ,4,6-Triisopropylbiphenyl (X-Phos, 0.64g, 1.36mmole) and palladium acetate (0.15g, 0.68mmole) are placed in the reaction tank, after fully dewatering, add toluene (100ml) and ethanol (30ml ), start stirring, add 2.0M potassium carbonate aqueous solution (40ml), and react at 120°C for 60 hours. Reduce the system temperature to room temperature, filter and collect the solids, dissolve the solids with hot toluene, filter with Celite while it is hot to remove the remaining metals, rinse with hot toluene, concentrate the collected toluene solution to a solid, and then use tetrahydrofuran It was digested with hexane to crystallize, and filtered to obtain compound 8 as a white solid (11.1 g, yield 80%).

¹ H NMR(CDCl ₃ ,400MHz)δ 8.85(d,2H), 8.41(d,4H), 8.12(s,2H), 8.40(s,1H), 8.12-7.90(m,9H), 7.87(dd , 2H), 7.82-7.78 (m, 6H), 7.64 (dd, 2H), 7.53-7.49 (m, 4H), 7.39-7.28 (m, 8H).

Synthesis Example 4: Synthesis of Compound 10

First, put acetophenone (15.0g, 124.8mmole) and 4-bromobenzaldehyde (24.3g, 131.1mmole) in the reaction tank, fully remove the water and add ethanol (EtOH, 150ml), turn on the stirring, and add hydroxide Sodium (NaOH, 1.4g, 35mmole), stirred at room temperature for 16 hours. After the reaction, the solid was collected by filtration, and the filtered solid was washed with water and ethanol without being refined and purified. After drying, compound E (20.5 g, crude yield 57%) was obtained as an off-white solid.

Then, compound E was put into the reaction tank again, and 4-chlorophenylhydrazine hydrochloride (15.0g, 78.5mmole) and ethanol (52ml) were added to the reaction tank, and sodium hydroxide (4.3g, 107.5mmole) Prepare 50 ml of ethanol solution, slowly add dropwise to the reaction tank and heat to 60°C for 30 hours. The reaction was terminated and cooled to room temperature. The solid was filtered and washed with water and ethanol. The solid was crystallized with toluene and hexane to obtain compound F (13.5 g, yield 45%) as a pale yellow solid.

Put compound F (13.5g, 32.0mmole), 2-naphthaleneboronic acid (6.6g, 38.4mmole) and tetrakis (triphenylphosphine) palladium (1.85g, 1.6mmole) in the reaction tank, and add toluene ( 46ml) and ethanol (13ml), start stirring and heating, and add dropwise 2.0M potassium carbonate aqueous solution (56ml), and react at 75°C for 16 hours. Reduce the system temperature to room temperature, filter and collect the solids, dissolve the solids with hot tetrahydrofuran, filter with diatomaceous earth and silica gel while it is hot to remove the remaining metals, then rinse with hot tetrahydrofuran and concentrate the collected solution to a solid. The tetrahydrofuran was digested with hexane to crystallize, and filtered to obtain compound G (9.4 g, yield 62%) as a white solid.

Put compound G (9.4g, 19.2mmole) and B-[4-(1-phenyl-1H-benzimidazol-2-yl)phenyl]-boronic acid (7.6g, 24.2mmole) in the reaction tank. After removing the water, add toluene (50ml) and ethanol (20ml), then add the pre-mixed palladium acetate (0.22g, 1.0mmole) and 2-dicyclohexylphosphorus-2,4,6-triisopropylbiphenyl ( X-Phos, 0.4g, 1.6mmole) toluene solution (20ml), finally add 2.0M potassium carbonate aqueous solution (35ml), heat and react at 80°C for 24 hours. Reduce the system temperature to room temperature, filter and collect the solids, then dissolve the solids with hot tetrahydrofuran, and filter with diatomaceous earth and a small amount of silica gel while it is hot to remove the remaining metal, then rinse with hot tetrahydrofuran and concentrate the collected solution to a solid. The crystallization was digested with tetrahydrofuran and toluene and filtered to obtain compound 10 (7.7 g, yield 56%) as a white solid.

¹ H NMR(CDCl ₃ ,400MHz)δ 8.83(d,2H),8.44(d,2H),8.34(dd,2H), 8.16(s,1H), 8.10(s,1H), 8.02-7.90(m ,6H),7.85(dd,1H),7.79(d,2H),7.69(q,4H),7.62-7.51(m,8H),7.41-7.35(m,3H),7.31-7.28(m,2H) ).

Synthesis Example 5: Synthesis of Compound 13

Put compound G (9.4g, 19.2mmole) and [4-(2-phenyl-1H-benzimidazol-1-yl)phenyl]boronic acid (7.6g, 24.2mmole) in the reaction tank, and fully remove water Add toluene (50ml) and ethanol (20ml), then add pre-mixed palladium acetate (0.22g, 1.0mmole) and 2-dicyclohexylphosphorus-2,4,6-triisopropylbiphenyl (X-Phos , 0.4g, 1.6mmole) toluene solution (20ml), finally add 2.0M potassium carbonate aqueous solution (35ml), heat and react at 80°C for 24 hours. Reduce the temperature of the system to room temperature, filter and collect the solids, then dissolve the solids with hot tetrahydrofuran, filter with diatomaceous earth and a small amount of silica gel while it is hot to remove the remaining metal, rinse with hot tetrahydrofuran, concentrate the collected solution to a solid, and then The crystallization was digested with tetrahydrofuran and toluene and filtered to obtain compound 13 (8.0 g, yield 57%) as a white solid.

¹ H NMR(CDCl ₃ ,400MHz)δ 8.88(d,2H),8.46(d,2H),8.35(dd,2H),8.17(s,1H),8.12(s,1H),7.99-7.96(m ,3H),7.91(t, 2H),7.86-7.84(m,4H),7.63(dd,2H),7.61-7.51(m,5H),7.41(d,2H),7.40-7.35(m,4H) ), 7.31-7.27 (m, 2H).

Comparative Synthesis Example 1: Synthesis of Compound C-3

Combine 2-(4-chlorophenyl)-4,6-diphenylpyrimidine (23.0g, 67.1mmole) with [4-(2-phenyl-1H-benzimidazol-1-yl)phenyl]boronic acid (25.3g, 80.5mmole) placed in the reaction tank, after fully dewatering, add toluene (140ml) and ethanol (40ml), then add pre-mixed palladium acetate (0.22g, 1.0mmole) and 2-dicyclohexylphosphorus- 2,4,6-Triisopropylbiphenyl (X-Phos, 0.4g, 1.6mmole) toluene solution (20ml), and finally add 2.0M potassium carbonate aqueous solution (70ml), heat and react at 80°C for 24 hours. Reduce the temperature of the system to room temperature, filter and collect the solids, then dissolve the solids with hot tetrahydrofuran, and filter with diatomaceous earth and a small amount of silica gel while it is hot to remove the remaining metals, rinse with hot tetrahydrofuran, concentrate the collected solution to a solid, and then The crystals were digested with ethyl acetate and filtered to obtain compound C-3 (21.0 g, yield 54%) as a white solid.

¹ H NMR(CDCl ₃ ,400MHz)δ 8.83(d,2H),8.312(d,2H),8.05(s,1H),7.90(d,1H),7.83(dd,4H),7.64(td,2H) ), 7.60-7.56 (m, 6H), 7.42 (d, 2H), 7.38-7.35 (m, 4H), 7.34-7.28 (m, 2H).

The physical property values of the above-mentioned materials are shown in Table 2. The measurement 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 ) and melting point (T _m )

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 gap value (E _g ) and energy level value of lowest unoccupied molecular orbital (LUMO)

The film of the above compound was measured with a UV/VIS spectrophotometer (Perkin Elmer, Lambda 365) to measure the boundary value (onset) of its absorption wavelength, and the value was converted to the energy gap value (E _g ), and the energy gap value was The value of HOMO energy level is subtracted to obtain LUMO energy level.

(5) Triplet energy value (E _T )

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 indium tin oxide (ITO) substrate is loaded into the evaporation system for use, the substrate is cleaned with solvent and ultraviolet ozone for degreasing. After that, the ITO substrate is transferred to a vacuum deposition chamber, and all layers are deposited on the top of the ITO 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 doped with 6% p HT-1 of NDP-1 type electrically conductive dopant, wherein the p-type electrically conductive dopant is purchased from Shanghai Hanfeng Chemical Co., Ltd., and the HT-1 is manufactured by Yulei Optoelectronics, as described in CN108336238; b) Hole transport layer, thickness 190 nm, HT-1; c) Exciton blocking layer, thickness 10 nm, HT-2 (manufactured by Yulei Optoelectronics); d) Light emitting layer, thickness 25 nm, including doped H-1 with 4% volume ratio of D-1, among which D-1 and H-1 are prepared by Yule Optoelectronics; e) Electron transport layer, thickness 20nm, containing compound 5 and doped lithium quinolate (Liq, produced by Yulei Optoelectronics), the volume ratio is 1:1; f) Electron injection layer, thickness 2nm, lithium quinolate (Liq, produced by Yulei Optoelectronics); and g) cathode, thickness about 150nm, Contains aluminum (Al).

The device structure can be expressed as: ITO/NDP-1: HT-1(20nm)/HT-1(190nm)/HT-2(10nm)/D-1: H-1(25nm) )/Compound 5: Liq(20nm)/Liq(2nm)/Al(150nm).

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 5: Manufacturing of organic electroluminescent devices

The layer structure of Example 2, Example 3, Example 4, and Example 5 is the same as that of Example 1, except that the compound 5 of the electron transport layer in Example 1 is replaced with compounds 6, 8, 10, and 13, respectively.

Comparative Example 1: Manufacturing of organic electroluminescent device

Except that the compound 5 of the electron transport layer in Example 1 is replaced with compound C-1, the organic electroluminescent element is fabricated into a layer structure similar to that of Example 1, wherein the compound C-1 is as described in JP2011003793A.

Comparative Example 2: Manufacture of organic electroluminescent device

Except that the compound 5 of the electron transport layer in Example 1 was replaced with compound C-2, the organic electroluminescent element was fabricated into a layer structure similar to that of Example 1. Among them, the compound C-2 was prepared by Al-Ray Optoelectronics, such as TWI619703 described.

Comparative Example 3: Manufacturing of organic electroluminescent device

Except that the compound 5 of the electron transport layer in Example 1 was replaced with compound C-3, the organic electroluminescence element was fabricated into a layer structure similar to that of Example 1, wherein the compound C-3 was prepared in Comparative Synthesis Example 1. Compound.

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 luminous properties at room temperature, and measured its driving voltage (V _d ), luminous efficiency, blue index (blue index) and current density of 50 milliamperes per square centimeter (mA/ The value of LT98 under cm ² ) is shown in Table 3. Among them, the value of LT98 is defined as the time it takes for the brightness level to drop to 98% of the initial brightness, which is used to evaluate the service life of the organic electroluminescent element Or a measure of stability.

As mentioned above, within the acceptable driving voltage, blue light index and luminous efficiency loss range, it can be seen that the organic electroluminescent device comprising the naphthyl substituted phenylpyrimidine compound with the structure of formula (I) of the present invention performs well Heat resistance and significantly improve its service life. Therefore, the organic electroluminescent element of the present invention is suitable for applications such as automotive displays and lighting sources, and has extremely high technical value.

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 protection scope of the present invention is exclusively determined by the application attached to the present invention. The definition of the scope of interest shall be included in the disclosed technical content as long as it does not affect the effects and implementation purposes of the present invention.

200‧‧‧Organic electroluminescence element

210‧‧‧Substrate

220‧‧‧Anode

230‧‧‧hole injection layer

240‧‧‧Hole Transmission Layer

245‧‧‧ exciton barrier

250‧‧‧Light-emitting layer

260‧‧‧Electron transport layer

270‧‧‧Electron injection layer

280‧‧‧Cathode

Claims (14)

A phenylpyrimidine compound substituted by naphthyl with the structure of formula (I):

Wherein, Ar represents substituted or unsubstituted C _3-30 heteroaryl containing heteroatoms selected from the group consisting of N, O, and S; R represents hydrogen, deuterium, tritium, substituted or unsubstituted A substituted C _6-30 aryl group, a substituted or unsubstituted C _5-30 heteroaryl group containing a different atom selected from the group consisting of N, O, and S, and Ar and R are different; m represents an integer from 1 to 3; and n represents an integer from 0 to 2. The naphthyl substituted phenylpyrimidine compound with the structure of formula (I) as described in item 1 of the scope of patent application, wherein the compound of formula (I) is represented by formula (I-1) or formula (I-2) Show by:

The naphthyl substituted phenylpyrimidine compound with the structure of formula (I) as described in item 1 of the scope of patent application, wherein the compound of formula (I) is represented by formula (I-3):

The naphthyl-substituted phenylpyrimidine compound with the structure of formula (I) as described in item 1 of the scope of patent application, wherein the compound of formula (I) is represented by formula (I-4) or formula (I-5) Show by:

The naphthyl-substituted phenylpyrimidine compound having the structure of formula (I) as described in item 1 of the scope of patent application, wherein Ar is a nitrogen-containing atom substituted by a C _1-4 alkyl group or a C _6-18 aryl group_的C _3-30 heteroaryl. The naphthyl substituted phenylpyrimidine compound with the structure of formula (I) as described in item 1 of the scope of patent application, wherein the C _3-30 heteroaryl group is triazinyl or benzimidazolyl. The naphthyl-substituted phenylpyrimidine compound with the structure of formula (I) described in item 6 of the scope of patent application, wherein the triazinyl group is substituted with at least one C _6-18 aryl group. The naphthyl substituted phenylpyrimidine compound with the structure of formula (I) as described in item 6 of the scope of patent application, wherein the benzimidazole group is selected from formula (A-1) or formula (A-2) structure:

Wherein, A ₁ and A ₂ each independently represent hydrogen, an unsubstituted C _6-18 aryl group or an unsubstituted C _1-4 alkyl group; and * is the bond between the group represented by Ar and the structure of formula (I) Knot position. The naphthyl substituted phenylpyrimidine compound having the structure of formula (I) as described in the first item of the patent application, wherein R is hydrogen, phenyl or naphthyl. The naphthyl substituted phenylpyrimidine compound with the structure of formula (I) as described in item 1 of the scope of patent application, wherein the compound of formula (I) is one of compound (5) and compound (13):

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 Naphthyl substituted phenylpyrimidine compounds. According to the organic electroluminescent device described in item 11 of the scope of patent application, the organic layer is an electron transport layer, and its thickness is between 15 nanometers and 30 nanometers. According to the organic electroluminescent device described in item 12 of the scope of patent application, wherein the electron transport layer further comprises an N-type electrically conductive dopant, and the content of the N-type electrically conductive dopant is 30% to 70% by weight %. According to the organic electroluminescent device described in item 13 of the scope of patent application, the N-type electrically conductive dopant is lithium quinolate.

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