TW202120489A - Pyrimidines derivatives and organic light-emitting element using the same - Google Patents

Abstract

The present invention provides pyrimidines derivatives of formula (I) and an organic light-emitting element using the same:

wherein X₁, X₂, X₃, m, n, p and q are as defined in the description.

Description

Pyrimidine derivative and its organic electroluminescence element

The present invention relates to a material for an organic electroluminescence device and an organic electroluminescence device using the material, and more particularly to a material for an organic electroluminescence device that can generate luminescence excimer complexes and the use of the material The organic electric excitation light element.

Organic electroluminescent element (OLED) has the characteristics of lightness, thinness, wide viewing angle, high contrast, low power consumption, high response speed, full-color painting and flexibility. Therefore, it is suitable for full-color display or portable Applications in electronic devices are highly anticipated.

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

In order to improve the efficiency of OLED devices, Chihaya Adachi of Kyushu University in Japan adopted appropriate molecular structure design to _{reduce the energy level difference (△E ST} ) between the singlet excited state and the triplet excited state, and increase the inverse system. Crossing the possibility of (Reverse Inter-System Crossing; RISC) to achieve Thermally Activated Delayed Fluorescence (TADF), so that the triplet excitons, which originally lost energy by thermal motion, can return to the singlet state It emits light to achieve 100% internal quantum efficiency that is theoretically the same as that of phosphorescent materials.

In addition, by generating exciplexes on the contact interface by two independent materials with charge transport properties, low △E _ST can also be achieved. Professor JJ Kim from South Korea uses exciplexes as a common host material. Organic electroluminescence element, the energy level difference between the highest occupied molecular orbital (HOMO) of the charge donor and the lowest unoccupied molecular orbital (LUMO) of the charge acceptor formed by the charge donor, its characteristics are similar to the singlet excited state and the triplet excited state Energy, so that the energy of the singlet and triplet states is completely transferred to the doped material, which greatly reduces the charge injection barrier. However, at present, the quantum efficiency and luminous efficiency of organic electroluminescent elements through TADF or exciplex are still common Poor, there is still room for improvement.

Therefore, there is an urgent need to develop an organic material that can significantly improve the performance of its organic electroluminescent device to meet the actual needs of the current display lighting industry.

The purpose of the present invention is to provide a novel material that has high quantum efficiency and luminous efficiency and is used in organic electroluminescent devices, which is different from those known in the prior art, and the exciplex is formed by the novel material. Glow.

The present invention provides a pyrimidine derivative with the structure of formula (I):

二唑基、經取代或未經取代之二氧硼戊環基、經取代或未經取代之芳基碸基、經取代或未經取代之二-(C₆-C₂₀)芳基-膦氧基及經取代或未經取代之C₆-C₂₀芳基亞碸基所組成群組中之一者； Wherein, X ₁ to X ₃ are the same or different, and are independently selected from halo, nitro, carbonyl, pyridyl, cyano, pyrazolyl, substituted or unsubstituted benzimidazolyl, substituted Or unsubstituted

Diazolyl, substituted or unsubstituted dioxaborolanyl, substituted or unsubstituted aryl sulfonyl, substituted or unsubstituted di-(C ₆ -C ₂₀ )aryl-phosphine One of the group consisting of an oxy group and a substituted or unsubstituted C ₆ -C _{20 aryl alkylene group;}

m and n are integers of 1 or 2;

p is an integer of 0, 1 or 2; and

q is an integer of 0 or 1.

In some embodiments of the present invention, the structure of formula (I) is represented by one of the structures of formula (I-1) to (I-3), and the p is an integer of 1 or 2:

In some embodiments of the present invention, the structure of formula (I) is the structure of formula (I-1), the X ₁ to X ₃ are the same and m, n, and p are the same; wherein, the X ₁ to X ₃ is selected from pyridyl or cyano.

In other embodiments of the present invention, the pyrimidine derivative is selected from one of the following compounds 1 to 4:

In some embodiments of the present invention, the structure of the formula (I) is the structure of the formula (I-2), the X ₁ to X ₂ are the same and m and n are the same; wherein, the X ₁ to X ₂ are For cyano.

In other embodiments of the present invention, the pyrimidine derivative is shown in compound (5):

In some embodiments of the present invention, the structure of formula (I) is a structure of formula (I-3), and the X ₃ series is a pyridyl group.

In other embodiments of the present invention, the pyrimidine derivative is shown in compound (6):

The present invention further provides an organic electroluminescent device, comprising: a cathode; an anode; and a light-emitting layer, which is formed between the cathode and the anode, and the light-emitting layer comprises the above-mentioned pyrimidine derivative with the structure of formula (I) and a light-emitting layer. Hole transmission material.

In some embodiments of the present invention, the thickness of the light-emitting layer is 15 nanometers (nm) to 30 nanometers (nm).

In some embodiments of the present invention, the hole transport material is a helical double fluorene ring compound having a structure of formula (II):

Wherein, G ₁ and G ₂ are the same or different, and each G ₁ and G ₂ independently represents the structure of formula (II-1) or formula (II-2):

Wherein, * represents the position of connecting the spiral double fluorene ring; each B system is the same or different, and B represents C _6- C ₃₀ aryl, C _5- C ₃₀ heterocyclic group, C _9- C ₃₀ fused poly _{A cyclic aromatic hydrocarbon group or a C 9-} C ₃₀ condensed polycyclic aromatic hydrocarbon group containing O, S or N heteroatoms, and R represents a C _6- C ₃₀ aryl group, a C _5- C ₃₀ heterocyclic group, or a divalent A C _9- C _{30 condensed polycyclic aromatic hydrocarbon group or a divalent C 9-} C ₃₀ condensed polycyclic aromatic hydrocarbon group containing O, S or N heteroatoms.

In other embodiments of the present invention, the helical double fluorene ring compound is selected from one of the following compounds (H-1) and (H-2):

In some embodiments of the present invention, the hole transport material is a heterocyclic compound having a structure of formula (III):

Wherein, X means that it contains O, S or N heteroatoms;

L ₁ represents a single bond or a C ₆ -C ₃₀ aryl group;

Ar ₁ represents a C ₆ -C ₉ aryl group, a di-(C ₆ -C ₉ )arylamino group, or at least one (C ₁ -C ₃₀ ) alkyl group substituted or unsubstituted C ₆ -C ₁₅ aryl group Base; and

Ar _{2 represents a C 6} -C ₁₅ aryl group substituted or unsubstituted by a C ₆ -C ₉ aryl group, a di-(C ₆ -C ₉ ) arylamino group, or at least one (C ₁ -C _{30) alkyl group} Group; or Ar ₂ , N and L _{1 are} combined to form a substituted or unsubstituted carbazole moiety, wherein _{at least one of Ar 1} and Ar ₂ has an aromatic hydrocarbon moiety having 10 to 15 carbon atoms.

In other embodiments of the present invention, the heterocyclic compound is compound (H-3):

In some embodiments of the present invention, the hole transport material is a heterocyclic compound having a structure of formula (IV):

Where X represents an oxygen or sulfur atom; and

Z represents a substituted or unsubstituted C ₃ -C ₁₁ heteroaromatic ring containing at least two nitrogens or a C ₂ -C ₆ alkyl group.

In other embodiments of the present invention, the heterocyclic compound is selected from one of the following compounds (H-4) and (H-5):

In some embodiments of the present invention, the weight ratio of the hole transport material and the pyrimidine derivative is 1:99 to 99:1.

In some embodiments of the present invention, the light-emitting layer includes a guest light-emitting body; wherein, the guest light-emitting system is a phosphorescent dopant, and the content of the phosphorescent dopant is 1 to 10% by weight.

In other embodiments of the present invention, the phosphorescent dopant includes at least one metal selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold. Compound.

In some embodiments of the present invention, at least one electron auxiliary layer is provided between the light-emitting layer and the cathode, and the electron auxiliary layer includes the pyrimidine derivative with the structure of formula (I) as described above.

According to the present invention, the pyrimidine derivative with the structure of formula (I) provided by the present invention has good and balanced transport properties. Therefore, when applied to the light-emitting layer, it can promote the accumulation of charge carriers on the contact interface and increase the probability of RISC , The organic electroluminescence element made can effectively improve its current efficiency, external quantum efficiency and luminous efficiency, and it has industrial value and application prospects.

100, 200, 300: organic electroluminescence element

110, 210, 310: substrate

120, 220, 320: anode

130, 230, 330: hole injection layer

140, 240, 340: hole transport layer

150, 250, 350: luminescent layer

160, 260, 360: electron transport layer

170, 270, 370: electron injection layer

180, 280, 380: cathode

245: Electron blocking layer

355: Hole barrier layer

The embodiments of the present invention will be described with reference to the drawings as an example:

Figure 1 is a schematic cross-sectional view of an embodiment of the organic electroluminescent device of the present invention;

Figure 2 is a schematic cross-sectional view of another embodiment of the organic electroluminescent device of the present invention;

Figure 3 is a schematic cross-sectional view of another embodiment of the organic electroluminescent device of the present invention;

Figures 4A to 4B are used to analyze the ultraviolet-visible light absorption spectrum, photoluminescence spectrum and low-temperature phosphorescence emission spectrum (from left to right, respectively, ultraviolet-visible light absorption spectrum, photoluminescence spectrum and low-temperature phosphorescence emission spectrum). Spectra of compounds 5 and 6;

Figures 5A and 5B are the analysis of the spectra containing compound 5 and compound H-3 by ultraviolet-visible light absorption spectroscopy and photoluminescence spectroscopy (from left to right are the ultraviolet-visible light absorption spectra and photoluminescence spectra, respectively), Time-resolved light-excited luminescence diagram;

Figures 6A and 6B are the spectra of compound 6 and compound H-3 analyzed by ultraviolet-visible light absorption spectroscopy and photoluminescence spectroscopy (from left to right are ultraviolet-visible light absorption spectra and photoluminescence spectra), Time-resolved light excitation luminescence diagram;

Figures 7A, 7B, and 7C are the brightness-voltage-current density graphs, quantum efficiency-brightness-power efficiency graphs, and electroluminescence spectra of the tenth to twelfth embodiments of the organic electroluminescent device of the present invention Figure; and

Figures 8A, 8B, and 8C are the brightness-voltage-current density graphs, quantum efficiency-brightness-power efficiency graphs, and electroluminescence of the thirteenth to fifteenth embodiments of the organic electroluminescent device of the present invention Spectrum.

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. Fall on Any value or point within the range described herein, for example, any integer, can be used as the minimum or maximum value to derive the lower range.

The present invention provides pyrimidine derivatives with the structure of formula (I):

二唑基、經取代或未經取代之二氧硼戊環基、經取代或未經取代之芳基碸基、經取代或未經取代之二-(C₆-C₂₀)芳基-膦氧基及經取代或未經取代之C₆-C₂₀芳基亞碸基所組成群組中之一者； Wherein, X ₁ to X ₃ are the same or different, and are independently selected from halo, nitro, carbonyl, pyridyl, cyano, pyrazolyl, substituted or unsubstituted benzimidazolyl, substituted Or unsubstituted

Diazolyl, substituted or unsubstituted dioxaborolanyl, substituted or unsubstituted aryl sulfonyl, substituted or unsubstituted di-(C ₆ -C ₂₀ )aryl-phosphine One of the group consisting of an oxy group and a substituted or unsubstituted C ₆ -C _{20 aryl alkylene group;}

m and n are integers of 1 or 2;

p is an integer of 0, 1 or 2; and

q is an integer of 0 or 1.

In this context, "halo" can be selected from fluoro, chloro, bromo and iodo.

In the text, "aryl" means aryl or (extended) aryl. The aryl refers to a monocyclic or condensed polycyclic ring derived from aromatic hydrocarbons, and includes phenyl, biphenyl, triphenyl, naphthyl , Binaphthyl, phenylnaphthyl, naphthylphenyl, stilbene, phenyl stilbene, benzo stilbene, dibenzo stilbene, phenanthryl, phenylphenanthryl, anthracenyl, indenyl, biphenyl Phenyl, pyrenyl, fused tetraphenyl, perylene, quinacyl, naphthonaphthyl, allenyl 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 -C ₃₀ alkyl, C ₁ -C ₃₀ alkoxy, C ₆ -C ₃₀ aryl, C ₅ -C ₃₀ heteroaryl aryl, substituted C ₆ -C ₃₀ aryl group of C ₅ -C ₃₀ heteroaryl group, benzimidazolyl group, C ₃ -C ₃₀ cycloalkyl, C ₅ -C ₇ heterocycloalkyl Group, tri-(C ₁ -C ₃₀ )alkylsilyl group, tri-(C ₁ -C ₃₀ )arylsilyl group, di-(C ₁ -C ₃₀ )alkyl-(C ₆ -C ₃₀ )aryl Alkyl silyl group, C ₁ -C ₃₀ alkyl bis-(C ₆ -C ₃₀ ) aryl silyl group, C ₂ -C ₃₀ alkenyl group, C ₂ -C ₃₀ alkynyl group, cyano group, di-(C _1- C ₃₀ )alkylamino group, di-(C ₆ -C ₃₀ )arylboronyl group, di-(C ₁ -C ₃₀ )alkylboronyl group, C ₁ -C ₃₀ alkyl group, C ₆ -C ₃₀ aryl group C ₁ -C ₃₀ alkyl group, C ₁ -C ₃₀ alkyl group, C ₆ -C ₃₀ aryl group, carboxyl group, nitro group and hydroxyl group. In addition, the range of the number of carbon atoms in this article can be extended from the lower limit to the upper limit. For example, C ₆ -C ₂₀ means that the number of carbon atoms can be 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20.

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" refers to heteroaryl or heteroaryl, and the 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 condensed 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.

The above-mentioned X ₁ to X ₃ are regarded as the electron withdrawing group of the pyrimidine core of the derivative, so the bonding position can be selected to be any position conducive to electron withdrawing, wherein each of X ₁ to X ₃ The bonding positions can be the same or different.

In a specific embodiment, the structure of formula (I) is represented by one of the structures of formula (I-1) to (I-3), and the p is an integer of 1 or 2:

In a specific embodiment, the above X ₁ to X ₃ are the same or different and are independently selected from the group consisting of halo, pyridyl, cyano, substituted or unsubstituted dioxaborolanyl One of them.

In another embodiment, the aforementioned X ₁ to X ₃ are independently selected from pyridyl or cyano.

In another embodiment, the above-mentioned m, n, and p values are the same.

When the structure of the formula (I) is the structure of the formula (I-1), the X ₁ to X ₃ are the same and m, n and p are the same; in a specific embodiment, the X ₁ to X ₃ are selected From pyridyl or cyano.

When the structure of the formula (I) is the structure of the formula (I-2), the X ₁ to X ₂ are the same and m and n are the same; in a specific embodiment, the X ₁ to X ₂ are selected from cyanogen base.

When the structure of the formula (I) is the structure of the formula (I-3), the X ₃ is a pyridyl group; in a specific embodiment, the X ₁ to X ₂ are selected from a cyano group.

Preferred examples of the aforementioned pyrimidine derivatives with the structure of formula (I) are selected from Table 1, but are not limited thereto.

Table 1

The present invention further provides an organic electroluminescent device, comprising: a cathode; an anode; and a light-emitting layer, which is formed between the cathode and the anode, and the light-emitting layer comprises the above-mentioned pyrimidine derivative with the structure of formula (I) and a light-emitting layer. The hole transport material uses the pyrimidine derivative of the formula (I) structure and the hole transport material as a light-emitting host, and exciplexes are generated at the contact interface of the common host material to emit light.

In the text, "exciplex" refers to the complex compound of the excited state generated by two independent charge-transporting materials at the contact interface. The luminescence phenomenon generated through the exciplex is called "Luminous Excimer Complex".

The pyrimidine derivative with the structure of formula (I) provided by the present invention has good and balanced transport properties, so when used as the host material of the light-emitting layer, it can promote the accumulation of charge carriers on the contact interface and increase the probability of RISC .

In a specific embodiment, the thickness of the light-emitting layer ranges from 15 nanometers (nm) to 30 nanometers (nm). In other examples, the thickness of the light-emitting layer can also be 20 nanometers (nm) or 25 nanometers (nm).

In a specific implementation aspect, the hole transport material is a helical double fluorene ring compound with a structure of formula (II):

Wherein, G ₁ and G ₂ are the same or different, and each G ₁ and G ₂ independently represents the structure of formula (II-1) or formula (II-2):

Wherein, * represents the position of connecting the spiral double fluorene ring; each B system is the same or different, and B represents C _6- C ₃₀ aryl, C _5- C ₃₀ heterocyclic group, C _9- C ₃₀ fused poly _{A cyclic aromatic hydrocarbon group or a C 9-} C ₃₀ condensed polycyclic aromatic hydrocarbon group containing O, S or N heteroatoms, and R represents a C _6- C ₃₀ aryl group, a C _5- C ₃₀ heterocyclic group, or a divalent A C _9- C _{30 condensed polycyclic aromatic hydrocarbon group or a divalent C 9-} C ₃₀ condensed polycyclic aromatic hydrocarbon group containing O, S or N heteroatoms.

The aforementioned examples of the helical double fluorene ring compound of formula (II) are disclosed in the TW I644887 patent, and the entire content thereof can be cited in the present invention.

In another embodiment, the hole transport material is a heterocyclic compound with the structure of formula (III):

Wherein, X means that it contains O, S or N heteroatoms;

L ₁ represents a single bond or a C ₆ -C ₃₀ aryl group;

Ar ₁ represents a C ₆ -C ₉ aryl group, a di-(C ₆ -C ₉ )arylamino group, or at least one (C ₁ -C ₃₀ ) alkyl group substituted or unsubstituted C ₆ -C ₁₅ aryl group Base; and

Ar _{2 represents a C 6} -C ₁₅ aryl group substituted or unsubstituted by a C ₆ -C ₉ aryl group, a di-(C ₆ -C ₉ ) arylamino group, or at least one (C ₁ -C _{30) alkyl group} Group; or Ar ₂ , N and L _{1 are} combined to form a substituted or unsubstituted carbazole moiety, wherein _{at least one of Ar 1} and Ar ₂ has an aromatic hydrocarbon moiety having 10 to 15 carbon atoms.

Examples of the aforementioned heterocyclic compound of formula (III) include: X represents S or O; L ₁ represents a single bond; and Ar ₁ and Ar ₂ each independently represent phenyl, naphthyl, biphenyl, dimethyl Phenyl or (diphenylamino) phenyl.

In another embodiment, the hole transport material is a heterocyclic compound with the structure of formula (IV):

Where X represents an oxygen or sulfur atom; and

Z represents a substituted or unsubstituted C ₃ -C ₁₁ heteroaromatic ring containing at least two nitrogens or a C ₂ -C ₆ alkyl group.

The foregoing examples of the heterocyclic compound of formula (IV) are disclosed in the CN 106608878 A patent, and the entire content can be cited in the present invention.

In a specific embodiment, the HOMO of the hole transport material and the LUMO of the pyrimidine derivative correspond to each other, that is, at the same energy level position.

In another embodiment, the weight ratio of the hole transport material and the pyrimidine derivative is 1:99 to 99:1.

The preferred embodiments of the aforementioned hole transport materials are selected from Table 2, but are not limited thereto.

Table 2

In one embodiment, the light-emitting layer of the organic electroluminescent device of the present invention includes a guest light-emitting body.

In a specific embodiment, the guest light-emitting system of the organic electroluminescent device of the present invention is a phosphorescent dopant, and the pyrimidine derivative and hole transport material with the structure of formula (I) are used as the light-emitting host material to promote The charge carriers accumulate on the contact interface, so that the energy of the singlet and triplet states is completely transferred to the phosphorescent dopant, which greatly reduces the charge injection barrier.

In the organic electroluminescent device of the present invention, the phosphorescent dopant content of the light-emitting layer is 1% to 10% by weight.

In another embodiment, the phosphorescent dopant includes at least one metal organometallic complex selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.

In another embodiment, the phosphorescent dopant system has a structure of the following formula (GD01).

The said organic electroluminescence element is an exciton complex formed by the combination of a pyrimidine derivative with the structure of formula (I) and the hole transport material, so that the triplet excitons that dissipate energy in the thermal motion mode can be recovered It emits light to the singlet state to improve the quantum efficiency of the whole device.

In the organic electroluminescent device of the present invention, in addition to the above-mentioned light-emitting layer, at least one electron auxiliary layer is provided between the light-emitting layer and the cathode, and the electron auxiliary layer includes the above-mentioned formula (I) Structure of pyrimidine derivatives.

The electron assistant can be an electron injection layer, an electron transport layer or a hole blocking layer.

In a specific embodiment, the electron auxiliary layer is a hole blocking layer, and the light-emitting layer provided in accordance with the aforementioned technical means of the present invention can be optimized and improved the performance of the light-emitting device.

In another embodiment, conventional materials can also be selected for the electronic auxiliary layer. Common materials used for the electron injection layer include alkali metal halides or alkali metal chelates containing nitrogen and oxygen, such as: LiF, 8-quinolinolato lithium (Liq).

二唑衍生物及、三嗪或三唑衍生物、有機鹼金屬/鹼土金屬錯合物、氧化物、鹵化物、碳酸鹽及含有至少一種選自鋰和銫金屬之磷酸鹼金屬/鹼土金屬鹽所組成之群組之至少一種。 The conventional hole blocking layer and electron transport layer materials include nitro substituted fluorene derivatives, diphenoquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidene methane derivatives, anthracene Quinodimethane and anthrone derivatives,

Diazole derivatives and triazine or triazole derivatives, organic alkali metal/alkaline earth metal complexes, oxides, halides, carbonates and alkali metal/alkaline earth metal salts containing at least one selected from lithium and cesium metals At least one of the group consisting of.

In the organic electroluminescent device capable of generating luminescence excimer complexes of the present invention, it may include at least one hole auxiliary layer formed between the light-emitting layer and the anode, and the hole auxiliary layer may be a hole Injection layer, hole transport layer or electron blocking layer.

唑衍生物、咪唑衍生物、咔唑衍生物、吲哚咔唑衍生物、聚芳基烷烴衍生物、吡唑啉衍生物及吡唑啉酮衍生物、苯二胺衍生物、芳基胺衍生物、氨基取代查爾酮衍生物、苯乙烯基蒽衍生物、芴酮衍生物、腙衍生物、芪衍生物、矽氮烷衍生物、苯胺系共聚物及噻吩低聚物所組成之群組之至少一者。 The material of the hole auxiliary layer can be selected from conventional materials. Common materials used for the hole auxiliary layer include triazole derivatives,

Azole derivatives, imidazole derivatives, carbazole derivatives, indolecarbazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives Group consisting of compounds, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers and thiophene oligomers At least one of them.

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 an 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, The electron transport layer 160, the electron injection layer 170, and the 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 electron blocking layer 245, a light emitting layer 250, an electron transport layer 260, an electron injection layer 270, and a cathode 280, and a first The difference in the figure is that the electron blocking layer 245 is disposed between the hole transport layer 240 and the light emitting layer 250.

FIG. 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, a hole 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 hole blocking layer 355 is disposed between the light emitting layer 350 and the electron transport layer 360.

The organic electroluminescent element of the structure shown in the above figures can be manufactured in the reverse direction. In the reverse structure, one or more layers can be added or removed as needed.

The anode is a metal or conductive compound with a high work function, and conventional materials can be selected including transparent metal oxides such as ITO, IZO, SnO ₂ , ZnO and other materials or substrates such as poly-Si and a-Si. The US 5844363 patent discloses a flexible transparent substrate combined with an anode, the entire content of which is cited in the present invention.

The cathode is a metal or conductive compound with a low work function, and conventional materials can be selected including Au, Al, In, Mg, Ca or similar metals, alloys, etc. The entire contents of the cathode are exemplified in the US 5703436 and US 5707745 patents As cited in the present invention, the cathode has a thin metal layer, such as magnesium/silver (Mg: Ag), and a transparent conductive layer (ITO Layer) covering the thin metal layer by sputtering deposition.

In addition, at least one of the above-mentioned electrodes needs to be transparent or semi-transparent to facilitate the penetration of the emitted light.

Structures and materials not specifically described can also be applied to the present invention. As disclosed in US Patent No. 5247190, organic electroluminescent devices including polymer materials (PLEDs), the entire contents of which are cited in the present invention. As exemplified in US Patent No. 20030230980, the n-type doped electron transport layer is doped with lithium in BPhen at a molar ratio of 1:1, and the entire content is quoted in the present invention. The applications and principles of the barrier layers disclosed in US Patent Nos. 6097147 and 20030230980 are all cited in the present invention. The entire contents of the injection layer illustrated in US Patent No. 20040174116 and the protective layer illustrated in the same case are cited in the present invention.

Unless otherwise limited, any layer in different embodiments can be deposited and formed using any appropriate method. As far as the organic layer is concerned, preferred methods include thermal evaporation and spray printing as disclosed in US Patent Nos. 6013982 and 6087196, the entire contents of which are cited in the present invention; organic vapor deposition disclosed in US Patent No. 6,337,102 Method (organic vapor phase deposition, OVPD), the entire contents of which are cited in the present invention; the organic vapor phase deposition method (deposition by organic vapor jet printing, OVJP) disclosed in U.S. Patent No. 10/233470, the entire contents of which are Quoted in the present invention. Other suitable methods include spin coating and solution-based processes. The solution-based process is preferably performed 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 US Patent Nos. 6294398 and 6468819, and the process of integrated spray printing or organic vapor spray deposition and patterning, all of which are the present invention Cited. Of course, other methods can also be used. The material used for deposition can be adjusted to correspond to its particular deposition method.

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 the conventional device, the present invention can significantly improve the service life and driving stability of the organic electroluminescent device.

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 1

Take a 100mL double-necked flask, add the compound 3-bromobenzonitrile (8.669g, 47.63mmol), trifluoromethanesulfonic anhydride (Tf ₂ O, 7.296g, 25.86mmol) and inject the dehydrated oxygen Dichloromethane (DCM, 15mL), after stirring until completely dissolved, add 3-bromoacetophenone (4.514g, 22.68mmol) and dichloromethane (15mL) solution, heat to 40 ℃ and make it Reflux, react for 2 days and then cool to room temperature, add saturated sodium bicarbonate aqueous solution (50mL), filter after solid precipitation, and wash with a large amount of methanol, and then vacuum dry the solid part to obtain a white solid compound A (10g, 18.35mmol,), the yield is 80%.

¹ H NMR (400MHz, CD ₂ Cl ₂ ) δ 8.82 (t, 1H), 8.67-8.62 (m, 1H), 8.44 (t, 2H), 8.23 (ddd, 2H), 8.01 (s, 1H), 7.70 (dddd,3H),7.46(dt,3H).

Take a 500mL double-necked flask and add compound A (5.985g, 10.98mmol), double pinacolato diboron (Bis(pinacolato)diboron, 10g, 39.44mmol), [1,1'-bis(diphenylphosphine) )Ferrocene]palladium(II) dichloride (Pd(dppf)Cl ₂ , 475mg, 0.65mmol), potassium acetate (KOAc, 7.7g, 79.16mmol), evacuated, pour argon gas, and then pour tetrahydrofuran ( THF, 160mL), stirred and heated to reflux. After 1 day of reaction, it was cooled to room temperature. After extraction with water and dichloromethane, the organic layer was taken and dried with anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure. Purification was performed by silica gel column chromatography with ethyl acetate and hexane extraction system to obtain white solid compound B (4.25 g 6.19 mmol), and the yield was 56%.

¹ H NMR (400MHz, CD ₂ Cl ₂ ) δ 9.02 (s, 1H), 8.88-8.77 (m, 1H), 8.63 (s, 2H), 8.52-8.43 (m, 2H), 8.16 (s, 1H) , 8.02-7.90 (m, 3H), 7.61 (dt, 3H), 1.40 (s, 36H).

Take a 250mL double-necked flask, add compound B (1.373g, 2mmol), 2-bromopyridine (2-bromopyridine, 1.043g, 6.6mmol), tetrakis (triphenylphosphine) palladium (Pd(PPh ₃ ) ₄ , 350g, 0.3mmol), potassium carbonate (K ₂ CO ₃ , 2.736g, 19.8mmol), evacuated and filled with argon gas, then filled with tri-tert-butyl phosphine (PtBu ₃ , 24mL, 0.05M), deoxygenated dioxane (dioxane, 30mL) and deionized water (20mL) with deoxygenated water (20mL), stirred and heated to reflux, stirred and reacted for 2 days and then cooled to room temperature. After extraction with water and dichloromethane, the organic layer was taken and replaced with anhydrous magnesium sulfate After drying and filtering, the filtrate was concentrated under reduced pressure, and then purified by silica gel column chromatography with ethyl acetate and dichloromethane extraction system to obtain white solid compound 1 (0.561g 1.04mmol), and its yield was 52%.

¹ H NMR (400MHz, CD ₂ Cl ₂ ) δ 9.40 (t, 1H), 9.02 (t, 2H), 8.87-8.81 (m, 1H), 8.77 (ddd, 3H), 8.49-8.42 (m, 2H) ,8.31(s,1H),8.28-8.20(m,3H),8.03-7.92(m,3H),7.90-7.81(m,3H),7.77-7.67(m,3H),7.38-7.28(m, 3H).

MS(m/z,MALDI)calcd for C ₃₇ H ₂₆ N ₅ 539.21 found 540.22(M+1).

Synthesis Example 2: Synthesis of Compound 2

Take a 250mL double-necked flask, add compound B (1.373g, 2mmol), 3-bromopyridine (3-bromopyridine, 1.043g, 6.6mmol), tetrakis(triphenylphosphine) palladium (Pd(PPh ₃ ) ₄ , 350g, 0.3mmol), potassium carbonate (K ₂ CO ₃ , 2.736g, 19.8mmol), evacuated and filled with argon, then inject tri-tert-butyl phosphine (P(t-Bu) ₃ , 24mL, 0.05M), in addition to Oxygen dioxane (30 mL) and deionized water (20 mL) were stirred and heated to reflux. The reaction was stirred for 2 days and then cooled to room temperature. After extraction with water and dichloromethane, the organic layer was taken. After drying with anhydrous magnesium sulfate, the filtrate was concentrated under reduced pressure after filtration, and then purified by silica gel column chromatography with ethyl acetate and dichloromethane extraction system to obtain white solid compound 2 (0.55g 1.02mmol, 50%).

MS(m/z,MALDI)calcd for C ₃₇ H ₂₆ N ₅ 539.21 found 540.22(M+1).

Synthesis Example 3: Synthesis of Compound 3

Take a 250mL double-necked flask and add compound B (2.180g, 4mmol), 4-pyridin-4-ylboronic acid (1.630g, 13.2mmol), tetrakis(triphenylphosphine) palladium (Pd(PPh ₃ ) ₄ , 0.7g, 0.6mmol), potassium carbonate (K ₂ CO ₃ , 5g, 36mmol), evacuated and filled with argon gas, then filled with tri-tert-butyl phosphine (PtBu3, 48mL, 0.05M), deoxygenated dioxins Dioxane (60 mL) and deionized water (36 mL) with deoxygenation were stirred and heated to reflux. After stirring and reacting for 2 days, it was cooled to room temperature. After extraction with water and dichloromethane, the organic layer was taken and replaced with anhydrous sulfuric acid. The magnesium was dried, filtered, and the filtrate was concentrated under reduced pressure, and then purified by silica gel column chromatography with ethyl acetate and dichloromethane extraction system to obtain white solid compound 3 (0.432g 0.8mmol) and its yield was 20%.

¹ H NMR (400MHz, CD ₂ Cl ₂ ) δ 9.04 (s, 1H), 8.81 (d, 1H), 8.71 (s, 6H), 8.60 (s, 2H), 8.40 (d, 2H), 8.19 (s) ,1H), 7.86(d,3H), 7.78-7.60(m,9H).

MS(m/z,MALDI)calcd for C ₃₇ H ₂₆ N ₅ 539.21 found 540.21(M+1).

Synthesis Example 4: Synthesis of Compound 4

Take 250mL double-necked flask, add compound B (1.373g, 2mmol), 3-bromobenzonitrile (3-bromobenzonitrile, 1.201g, 6.6mmol), tetrakis (triphenylphosphine) palladium (Pd(PPh ₃ ) ₄ , 350mg , 0.3mmol), potassium carbonate (K ₂ CO ₃ , 2.736g, 19.8mmol), evacuated and filled with argon gas, then filled with tri-tert-butyl phosphine (PtBu3, 24mL, 0.05M), deoxygenated dioxane (dioxane, 30mL), deionized water (20mL) with deoxygenated, stirred and heated to reflux. After stirring and reacting for 2 days, it was cooled to room temperature. After extraction with water and dichloromethane, the organic layer was taken and replaced with anhydrous magnesium sulfate. After drying and filtering, the filtrate was concentrated under reduced pressure, and then purified by silica gel column chromatography with hexane and dichloromethane extraction system to obtain white solid compound 4 (0.734g 1.2mmol) with a yield of 60% .

¹ H NMR (400MHz, CD ₂ Cl ₂ ) δ 8.96 (t, 1H), 8.80 (dt, 1H), 8.53 (t, 2H), 8.42-8.34 (m, 2H), 8.20 (s, 1H), 8.06 -7.95(m,6H),7.82-7.63(m,12H).

MS(m/z,MALDI)calcd for C ₄₃ H ₂₆ N ₅ 611.21 found 612.22(M+1).

Synthesis Example 5: Synthesis of Compound 5

Take a 1000mL double-necked flask and add (E)-1,3-bis(3-bromophenyl)-prop-2-en-1-one (16.1g, 44mmol) and benzamidine hydrochloride (6.25g, 40mmol) And stir bar, set the condenser, and then inject ethanol (EtOH, 460mL) into the syringe, heat to 85℃ and make it reflux, wait for the solid to dissolve, slowly add potassium hydroxide aqueous solution (KOH, 2.13M, 60mL ), after stirring and reacting for 4 hours, cooling to room temperature, after solid precipitation, filtered and washed with methanol, and then drained under high vacuum to obtain white solid compound C (14.92g, 32mmol), its yield Is 80%.

¹ H NMR (400MHz, CD ₂ Cl ₂ ) δ 8.69 (dt, 2H), 8.48 (t, 2H), 8.29-8.20 (m, 2H), 8.00 (s, 1H), 7.71 (ddd, 2H), 7.59 -7.53(m,3H),7.47(t,2H).

Take a 500mL double-necked flask and add compound C (4.661g, 10mmol), double pinacolato diboron (Bis(pinacolato)diboron, 6.094g, 24mmol), [1,1'-bis(diphenylphosphine) Ferrocene] Palladium(II) dichloride (Pd(dppf)Cl ₂ , 300mg, 0.4mmol), potassium acetate (KOAc) (4.71g, 48mmol) and a stir bar, set the condenser tube, and pour it in after vacuuming Argon, then deoxygenated tetrahydrofuran (THF, 160mL) was injected into a syringe, stirred and heated to reflux, stirred and reacted for 1 day and then cooled to room temperature. After extraction with water and dichloromethane, the organic layer was taken to After drying with anhydrous magnesium sulfate, after filtering, the filtrate was concentrated under reduced pressure, and then purified by silica gel column chromatography with hexane and ethyl acetate extraction system to obtain white solid compound D (1.84g 6mmol). The yield was 60%.

¹ H NMR (400MHz, CD ₂ Cl ₂ ) δ 8.75-8.68 (m, 2H), 8.62 (s, 2H), 8.48 (ddd, 2H), 8.17 (s, 1H), 7.96 (dt, 2H), 7.66 -7.51(m,5H), 1.40(s,24H).

Take a 500mL double-necked flask and add compound D (5.603g, 10mmol), 3-bromobenzonitrile (3-bromobenzonitrile, 4.004g, 22mmol), tetrakis (triphenylphosphine) palladium (Pd(PPh ₃ ) ₄ , 1155mg, 1mmol) and potassium carbonate (K ₂ CO ₃ , 8.28g, 60mmol). After vacuuming, pour argon gas, then inject tri-tert-butyl phosphine (PtBu ₃ , 80mL, 0.05M), deoxygenated tetrahydrofuran (THF, 150mL ), deoxidized deionized water (60 mL), stirred and heated to reflux, stirred and reacted for 2 days and then cooled to room temperature. After extraction with water and dichloromethane, the organic layer was taken, dried with anhydrous magnesium sulfate, and filtered. The filtrate was concentrated under reduced pressure, and then purified by silica gel column chromatography with a hexane and dichloromethane extraction system to obtain a white solid compound 5 (5.6 g 9.18 mmol) with a yield of 92%.

¹ H NMR (400MHz, CD ₂ Cl ₂ ) δ 8.78-8.69 (m, 2H), 8.52 (t, 2H), 8.42-8.31 (m, 2H), 8.16 (s, 1H), 8.02 (dd, 2H) , 7.98 (ddd, 2H), 7.78 (ddd, 2H), 7.75-7.68 (m, 4H), 7.64 (td, 2H), 7.61-7.52 (m, 3H).

MS(m/z,MALDI)calcd for C ₃₆ H ₂₃ N ₄ 510.18 found 511.19(M+1).

Synthesis Example 6: Synthesis of Compound 6

Take a 1000mL double-necked flask and add (E)-1,3-bis(3-bromophenyl)-prop-2-en-1-one (6.65g, 18.15mmol), 3-Amidinopyridine hydrochloride , 2.6g, 16.5mmol) and a stir bar, set the condenser, and then inject ethanol (EtOH, 200mL) into a syringe, heat and reflux to 85℃, wait for the solid to dissolve, and slowly add the potassium hydroxide aqueous solution (KOH, 2.13M, 25mL), stirred and reacted for 24 hours and then cooled to room temperature. After the solid precipitated, it was filtered with a glass filter plate, washed with a large amount of methanol, and then drained through high vacuum to obtain a white solid compound E (2.312g, 4.95mmol), the yield is 60%.

¹ H NMR(400MHz, CD ₂ Cl ₂ )δ 9.83(d,1H), 8.91(dt,1H), 8.74(dd,1H), 8.46(d,2H), 8.22(d,2H), 8.03(s ,1H), 7.71(dd,2H),7.52-7.42(m,3H).

Take a 500mL double-necked flask and add compound E (4.671g, 10mmol), double pinacolato diboron (Bis(pinacolato)diboron, 6.094g, 24mmol), [1,1'-bis(diphenylphosphine) Ferrocene] Palladium(II) dichloride (Pd(dppf)Cl ₂ , 300mg, 0.4mmol) and potassium acetate (KOAc, 4.71g, 48mmol), evacuated and filled with argon, and then injected with deoxygenated tetrahydrofuran (THF, 160mL), stirred and heated to reflux. After stirring and reacting for 1 day, it was cooled to room temperature. After extraction with water and dichloromethane, the organic layer was taken, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure , And then purified by silica gel column chromatography with hexane and ethyl acetate extraction system to obtain a white solid compound F (1.23g 4mmol), the yield is 40%.

¹ H NMR (400MHz, CD ₂ Cl ₂ ) δ 9.94-9.78 (m, 1H), 8.96 (dt, 1H), 8.74 (dd, 1H), 8.63 (s, 2H), 8.51-8.41 (m, 2H) , 8.21 (s, 1H), 7.97 (dt, 2H), 7.61 (t, 2H), 7.51-7.45 (m, 1H), 1.40 (s, 24H).

Take 500mL two-neck flask, compound F (2.241g, 4mmol), 3- bromoxynil (3-bromobenzonitrile, 1.602g, 8.8mmol ), tetrakis (triphenylphosphine) palladium _{(Pd (PPh 3) 4,} 462mg , 0.4mmol) and potassium carbonate (K ₂ CO ₃ , 3.312g, 24mmol), evacuated and filled with argon, then inject tri-tert-butyl phosphine (PtBu3, 32mL, 0.05M), deoxygenated tetrahydrofuran (THF, 60 mL), deionized deionized water (24 mL), stirred and heated and allowed to reflux. After stirring and reacting for 2 days, it was cooled to room temperature. After extraction with water and dichloromethane, the organic layer was taken, dried with anhydrous magnesium sulfate, and filtered Then the filtrate was concentrated under reduced pressure, and then purified by silica gel column chromatography with hexane and dichloromethane extraction system to obtain white solid compound 6 (0.9 g 1.76 mmol) with a yield of 44%.

¹ H NMR (400MHz, CD ₂ Cl ₂ ) δ 9.90 (d, 1H), 8.97 (dt, 1H), 8.75 (dd, 1H), 8.54 (t, 2H), 8.43-8.28 (m, 2H), 8.22 (s, 1H), 8.07-7.90 (m, 4H), 7.80 (ddd, 2H), 7.72 (ddd, 4H), 7.65 (td, 2H), 7.50 (ddd, 1H).

MS(m/z,MALDI)calcd for C ₃₅ H ₂₂ N ₅ 511.18 found 512.19(M+1).

Test examples 1 to 6

The physical properties and optical properties of the materials of synthesis examples 1 to 6 were analyzed and recorded in Table 3, and the measurement methods 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 cracking properties of the prepared compound were measured at a temperature program rate of 20°C/min. The temperature at which the weight is reduced to 95% of the initial weight is the thermal cracking temperature (T _d ).

(2) Glass transition temperature (T _g )

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

(3) The energy level 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 by 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)

_{Measure the boundary value (λ onset} ) of the absorption wavelength of the film of the above compound with a UV/VIS spectrophotometer (Perkin Elmer, Lambda 365), and convert the value to the energy gap value (E _g ) to make the energy gap value Subtract the value of the HOMO energy level to obtain the LUMO energy level.

(5) Triplet energy value (E _T )

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

(6) Spectral analysis

i. Ultraviolet-visible light (UV-VIS) absorption method

The pyrimidine derivative film synthesized above was measured with a UV-VIS spectrophotometer (Perkin Elmer, Lambda 20) to measure its longest absorption wave front wavelength (λ _ex ), and λ _{ex was} calculated by the formula to convert into the molecular energy gap Recorded in Table 3.

ii. Photoluminescence spectrometry

The pyrimidine derivative film synthesized above was measured with a UV/VIS spectrophotometer (Perkin Elmer, Lambda 20) with the longest absorption wave front wavelength (λ _ex ) as the excitation wavelength, and a photoluminescence spectrometer (Perkin Elmer , Luminescence Spectrometer LS55) measured the emission wavelength (λ _em ) at room temperature, and the analysis results are shown in Table 3.

iii. Low-temperature phosphorescence emission spectrometry

For example, the operation of the photoluminescence spectroscopy analysis method, except that the pyrimidine derivative film is placed in a low temperature (77K) environment of liquid nitrogen for measurement, the materials of synthesis examples 5 and 6 are selected for analysis, and the analysis results are respectively Shown in Figures 4A and 4B.

Comparative test example 1

The compound C-01 with Exciplex properties described in the synthetic document ACS Appl.Mater.Interfaces 2016,87,4811 was selected for physical and optical properties analysis and recorded in Table 3, and the measurement method is as described in Test Example 1 above.

table 3

Test examples 7 to 11

For the materials of compound H-1 to compound H-5 in the text, the physical properties were analyzed and recorded in Table 4, and the measurement method was as described in Test Example 1 above.

Table 4

Test examples 12 to 17

The pyrimidine derivatives synthesized above were mixed with compound H-3 at a weight ratio of 1:1 to form a thin film, and the luminescence spectra were measured by the ultraviolet-visible light absorption method and photoluminescence spectroscopy of the above test example 1, and they were recorded in Table 5 shows the spectral analysis results of the mixed film of compound 5 and compound 6 in Fig. 5A and Fig. 6A, respectively.

Next, in order to understand the thermally activated delayed fluorescence (TADF) phenomenon of the luminescent excimer, the following analysis was performed:

(1) Time-resolved photoluminescence

After measuring the above-mentioned photoluminescence, the decay curve is further measured, that is, the photoluminescence spectrum is analyzed with respect to the time of its emission wavelength, and the electron decay lifetime τ is recorded in Table 5, and shown in Figures 5B and 6B Respectively show the time-analyzed light-excited luminescence results of the mixed film of compound 5 and 6.

(2) Photoluminescence quantum yield (PLQY)

Using the wavelength of the longest absorption peak obtained in the UV-VIS absorption analysis as the excitation wavelength, the photoluminescence of the above-mentioned film was measured with a photo-induced quantum efficiency measurement system (HORIBA Quanta-φ) at room temperature and in a nitrogen environment Quantum Yield (PLQY), and the analysis results are recorded in Table 5.

table 5

Comparative test examples 1 to 5

The compound C-01 of the comparative test example was mixed with the above-mentioned compounds H-1 to H-5 at a weight ratio of 1:1 to form a thin film. Refer to the analysis methods of Test Example 1 and Test Example 12 to perform the ultraviolet-visible light absorption method, Photoluminescence spectroscopy, time-resolved photoluminescence and photoluminescence quantum yield analysis, and the above results are recorded in Table 6 respectively.

Table 6

Example 1: Manufacturing of organic electroluminescent device

Before the substrate is loaded into the evaporation system for use, the substrate is cleaned with solvent and ultraviolet ozone for degreasing. After that, the substrate is transferred to a vacuum deposition chamber, and all layers are deposited on the top of the substrate. According to Figure 3, the layers are sequentially deposited ^{by a heated evaporation boat at a vacuum of about 10 -6 Torr:}

a) Indium tin oxide layer (ITO) with a thickness of 1350 angstroms (Å);

b) Hole injection layer with a thickness of 60 nanometers (nm), including Tris-PCz _{doped with 3% by weight ReO 3;}

c) Hole transport layer, thickness 15 nanometers (nm), Tris-PCz;

d) The light-emitting layer, with a thickness of 20 nanometers (nm), is composed of compound 5 and compound H-3 as a host material, and is doped with a guest luminous body GD01, and the guest luminous body GD01 is prepared by Yule Optoelectronics, wherein the compound 5 The weight ratio of compound H-3 and compound H-3 is 1:1, and the doping volume ratio of the guest luminous body GD01 is 1%;

e) Hole blocking layer: thickness 10 nanometers (nm), compound 5;

f) Electron transport layer, thickness 50 nanometers (nm), C-01;

g) Electron injection layer with a thickness of 15 angstroms (Å), lithium quinolate (Liq); and

h) Cathode, about 1500 angstroms (Å) thick, aluminum (Al).

The device structure can be expressed as: ITO (1350 angstroms) / ReO ₃ : Tris-PCz (60 nanometers) / Tris-PCz (15 nanometers) / compound 5: Tris-PCz: GD01 (20 nanometers) / compound 5 ( 10nm)/C-01(50nm)/Liq(15A)/Al(150nm).

After the above-mentioned layers are deposited and formed, the component 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 electroluminescent element has a light-emitting area of 0.09 square millimeters.

Examples 2 to 15: Manufacturing of organic electroluminescent devices

The organic electroluminescent devices of Examples 2 to 6 were prepared with the same layer structure and manufacturing method of Example 1, except that the host material composition of the light-emitting layer and the volume ratio of the guest light-emitting body GD01 were changed as shown in Table 7.

Comparative Examples 1 to 3: Manufacturing of Organic Electroluminescent Devices

The organic electroluminescent elements of Comparative Examples 1 to 3 were prepared with the same layer structure and manufacturing method of Example 1, but the host material components of the light-emitting layer were changed to compound C-01 and compound H-3, and the guest light-emitting body was changed. The volume ratio of GD01 is shown in Table 8.

The electroluminescence properties of the above-mentioned organic electroluminescence elements are made by constant current source (KEITHLEY 2400 Source Meter, made by Keithley Instruments, Inc., Cleveland, Ohio) and photometer (PHOTO RESEARCH SpectraScan PR 650, made by Photo Research, Inc., Chatsworth, Calif.) measured its luminescence properties at room temperature, including the device driving voltage (V _on ), the operating voltage of the organic electroluminescent device operating to a brightness of 1000 nits (V ₁₀₀₀ ), external quantum efficiency (EQE), current efficiency (CE) and luminous efficiency (PE), maximum external quantum efficiency (EQE _max ), current efficiency (CE _max ) and luminous efficiency (PE _max ), electroluminescence maximum wavelength (λ _max ), color space coordinates (CIE(x,y)) and other performance results are shown in Table 7, and the brightness-voltage-current density curves, quantum efficiency-brightness-power efficiency curves of Examples 10 to 15 and The electroluminescence spectra are shown in Figures 7A to 8C. In Figures 7A and 8A, the arrows indicate the brightness-voltage curve, and the arrows in Figures 7B and 8B indicate the quantum efficiency-luminance curve.

Table 7

Table 7 (continued)

Table 8

Table 8 (continued)

As described in Table 7 and Table 8, since the pyrimidine derivative with the structure of formula (I) in the above-mentioned light-emitting layer has good and balanced transport properties, when it forms a light-emitting excimer complex with the above-mentioned hole transport material, it can It is beneficial to improve the current efficiency, external quantum efficiency, luminous efficiency and other properties of its organic electroluminescent elements, and it has industrial value and application prospects.

The above-mentioned embodiments are only illustrative descriptions, and are not used to limit the present invention. Anyone who is 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 effect and implementation purpose of the present invention.

300: Organic electroluminescence element

310: substrate

320: anode

330: hole injection layer

340: hole transport layer

350: luminescent layer

355: Hole Blocking Layer

360: electron transport layer

370: electron injection layer

380: Cathode

Claims (21)

A pyrimidine derivative with the structure of formula (I):

Wherein, X ₁ to X ₃ are the same or different, and are independently selected from halo, nitro, carbonyl, pyridyl, cyano, pyrazolyl, substituted or unsubstituted benzimidazolyl, substituted Or unsubstituted

Diazolyl, substituted or unsubstituted dioxaborolanyl, substituted or unsubstituted aryl sulfonyl, substituted or unsubstituted di-(C ₆ -C ₂₀ )aryl-phosphine One of the group consisting of an oxy group and a substituted or unsubstituted C ₆ -C _{20 aryl alkylene group;} m and n are integers of 1 or 2; p is an integer of 0, 1 or 2; and q is an integer of 0 or 1. The pyrimidine derivative described in item 1 of the scope of patent application, wherein the structure of formula (I) is represented by one of the structures of formula (I-1) to (I-3), and the p is 1 or 2 Integer:

The pyrimidine derivative described in item 2 of the scope of patent application, wherein the structure of formula (I) is the structure of formula (I-1), the X ₁ to X ₃ are the same and m, n and p are the same. The pyrimidine derivative described in item 2 of the scope of patent application, wherein the X ₁ to X ₃ are selected from pyridyl or cyano. The pyrimidine derivative described in item 3 of the scope of the patent application is selected from one of the following compounds 1 to 4:

The pyrimidine derivative described in item 2 of the scope of patent application, wherein the structure of formula (I) is the structure of formula (I-2), the X ₁ to X ₂ are the same and m and n are the same. The pyrimidine derivatives described in item 6 of the scope of patent application are shown in compound (5):

The pyrimidine derivative described in item 2 of the scope of patent application, wherein, when the structure of formula (I) is the structure of formula (I-3), the X ₃ is a pyridyl group. The pyrimidine derivatives described in item 8 of the scope of patent application are shown in compound (6):

An organic electroluminescence element, including: cathode; Anode; and The light-emitting layer is formed between the cathode and the anode, and the light-emitting layer includes the pyrimidine derivative with the structure of formula (I) and the hole transport material as described in the first item of the patent application. The organic electroluminescent device described in item 10 of the scope of patent application, wherein the thickness of the light-emitting layer is 15 nanometers (nm) to 30 nanometers (nm). The organic electroluminescent device described in item 10 of the scope of patent application, wherein the hole transport material is a helical double fluorene ring compound with a structure of formula (II):

Wherein, G ₁ and G ₂ are the same or different, and each G ₁ and G ₂ independently represents the structure of formula (II-1) or formula (II-2):

Wherein, * represents the position of connecting the spiral double fluorene ring; each B system is the same or different, and B represents C _6- C ₃₀ aryl, C _5- C ₃₀ heterocyclic group, C _9- C ₃₀ fused poly _{A cyclic aromatic hydrocarbon group or a C 9-} C ₃₀ condensed polycyclic aromatic hydrocarbon group containing O, S or N heteroatoms, and R represents a C _6- C ₃₀ aryl group, a C _5- C ₃₀ heterocyclic group, or a divalent A C _9- C _{30 condensed polycyclic aromatic hydrocarbon group or a divalent C 9-} C ₃₀ condensed polycyclic aromatic hydrocarbon group containing O, S or N heteroatoms. According to the organic electroluminescent device described in item 12 of the scope of patent application, the helical double fluorene ring compound is selected from one of the following compounds (H-1) and (H-2):

The organic electroluminescent device described in item 10 of the scope of patent application, wherein the hole transport material is a heterocyclic compound with a structure of formula (III):

Wherein, X means that it contains O, S or N heteroatoms; L ₁ represents a single bond or a C ₆ -C ₃₀ aryl group; Ar ₁ represents a C ₆ -C ₉ aryl group, a di-(C ₆ -C ₉ )arylamino group, or at least one (C ₁ -C ₃₀ ) alkyl group substituted or unsubstituted C ₆ -C ₁₅ aryl group Base; and Ar _{2 represents a C 6} -C ₁₅ aryl group substituted or unsubstituted by a C ₆ -C ₉ aryl group, a di-(C ₆ -C ₉ ) arylamino group, or at least one (C ₁ -C _{30) alkyl group} Group; or Ar ₂ , N and L _{1 are} combined to form a substituted or unsubstituted carbazole moiety, wherein _{at least one of Ar 1} and Ar ₂ has an aromatic hydrocarbon moiety having 10 to 15 carbon atoms. The organic electroluminescent device described in item 14 of the scope of patent application, wherein the heterocyclic compound is compound (H-3):

The organic electroluminescent device described in item 10 of the scope of patent application, wherein the hole transport material is a heterocyclic compound with a structure of formula (IV):

Where X represents an oxygen or sulfur atom; and Z represents a substituted or unsubstituted C ₃ -C ₁₁ heteroaromatic ring containing at least two nitrogens or a C ₂ -C ₆ alkyl group. The organic electroluminescent device described in item 16 of the scope of patent application, wherein the heterocyclic compound is selected from one of the following compounds (H-4) and (H-5):

According to the organic electroluminescent device described in item 10 of the scope of patent application, the weight ratio of the hole transport material and the pyrimidine derivative is 1:99 to 99:1. The organic electroluminescent device according to item 10 of the scope of patent application, wherein the light-emitting layer includes a guest light-emitting body, the guest light-emitting system is a phosphorescent dopant, and the content of the phosphorescent dopant is 1 to 10 wt. %. The organic electroluminescent device according to item 19 of the scope of patent application, wherein the phosphorescent dopant includes at least one selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold The metal organometallic complexes. The organic electroluminescent device according to item 10 of the scope of patent application, wherein at least one electron auxiliary layer is provided between the light-emitting layer and the cathode, and the electron auxiliary layer includes the first item in the scope of patent application. Said pyrimidine derivative with the structure of formula (I).

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