阅读说明：本技术 一种p型掺杂空穴注入化合物及其应用 (P-type doped hole injection compound and application thereof ) 是由 马晓宇 王进政 张雪 赵贺 陈明 崔建勇 孙峰 于 2020-07-30 设计创作，主要内容包括：本发明公开了一种P型掺杂空穴注入化合物,所述化合物的结构如化学式I所示：<Image he="366" wi="462" file="DDA0002610703620000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>化学式I；其中,R<Sub>1</Sub>＝R<Sub>7</Sub>；R<Sub>2</Sub>＝R<Sub>6</Sub>；R<Sub>4</Sub>＝R<Sub>10</Sub>；R<Sub>5＝</Sub>R<Sub>9</Sub>；R<Sub>3</Sub>＝R<Sub>8</Sub>；且,R<Sub>1</Sub>≠R<Sub>4</Sub>；R<Sub>2</Sub>≠R<Sub>5</Sub>；或,R<Sub>1</Sub>＝R<Sub>4</Sub>＝R<Sub>7</Sub>＝R<Sub>9</Sub>；R<Sub>2</Sub>＝R<Sub>5</Sub>＝R<Sub>6</Sub>＝R<Sub>10</Sub>；且,R<Sub>3</Sub>＝R<Sub>8</Sub>；R<Sub>1</Sub>-R<Sub>10</Sub>彼此独立地选自氢、氘、卤素、氰基、硝基、三氟甲基、羟基、磺酸基、磷酸基、OCF<Sub>3</Sub>、SCF<Sub>3</Sub>、C1-C10烷氧基、取代或非取代的C1-C30的烷基、取代或未取代的C2-C30的烯基、取代或未取代的C3-C30的环烷基、取代或非取代的C6-C30芳基、取代或非取代的C3-C30的杂芳基；且,R<Sub>1</Sub>-R<Sub>10</Sub>至少一个不为氢。掺杂了本发明提供的p型掺杂空穴注入化合物的空穴注入层制备的有机电致发光器件的驱动电压更低,发光效率更高,使用寿命更长。(The invention discloses a P-type doped hole injection compound, which has a structure shown as a chemical formula I: chemical formula I; wherein R is 1 ＝R 7 ；R 2 ＝R 6 ；R 4 ＝R 10 ；R 5＝ R 9 ；R 3 ＝R 8 (ii) a And, R 1 ≠R 4 ；R 2 ≠R 5 (ii) a Or, R 1 ＝R 4 ＝R 7 ＝R 9 ；R 2 ＝R 5 ＝R 6 ＝R 10 (ii) a And, R 3 ＝R 8 ；R 1 ‑R 10 Independently of one another, from hydrogen, deuterium, halogen, cyano, nitro, trifluoromethyl, hydroxyl, sulfonic acid, phosphoric acid, OCF 3 、SCF 3 C1-C10 alkoxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; and, R 1 ‑R 10 At least one is not hydrogen. The organic electroluminescent device prepared by the hole injection layer doped with the p-type doped hole injection compound provided by the invention has the advantages of lower driving voltage, higher luminous efficiency and longer service life.)

1. A P-type doped hole injection compound, wherein the structure of the compound is shown in formula I:

wherein R is₁＝R₇；R₂＝R₆；R₄＝R₁₀；R_5＝R₉；R₃＝R₈(ii) a And, R₁≠R₄；R₂≠R₅；

Or the like, or, alternatively,

R₁＝R₄＝R₇＝R₉；R₂＝R₅＝R₆＝R₁₀(ii) a And, R₃＝R₈；

R₁-R₁₀Independently of one another, from hydrogen, deuterium, halogen, cyano, nitro, trifluoromethyl, hydroxyl, sulfonic acid, phosphoric acid, OCF₃、SCF₃C1-C10 alkoxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl;

and, R₁-R₁₀At least one is not hydrogen.

2. The P-type doped hole injection compound of claim 1, wherein the halogen is selected from fluorine, chlorine, bromine, or iodine.

3. The P-type doped hole injection compound according to claim 1, wherein the "substituted" group in "substituted or unsubstituted" is selected from one or more of deuterium, halogen, nitrile, hydroxyl, carbonyl or nitro.

4. A method of preparing a P-doped hole injection compound according to any one of claims 1 to 3, comprising the steps of:

s1: slowly dripping the tetrahydrofuran solution of the reactant B into the tetrahydrofuran solution of lithium hydride at the temperature of 0 ℃, then heating to room temperature for reaction for 30-60min, and then cooling to 0 ℃ again;

s2: dropwise adding a tetrahydrofuran solution of the reactant A into the solution obtained in the step S1, reacting for 15-20h at 25-30 ℃, then pouring into ice water, adjusting the pH value to 1.0-2.0, extracting for three times by using ethyl acetate, combining organic phases, washing by using saturated saline solution, water and sodium bicarbonate aqueous solution in sequence, drying by using sodium sulfate, and removing the solvent to obtain an intermediate C;

s3: adding the intermediate C into tetrahydrofuran, adding [ bis (trifluoroacetoxy) iodine ] benzene, stirring at room temperature, concentrating the solvent, then dripping into cold ethanol while stirring, and performing suction filtration, washing and drying on the precipitated solid to obtain a crude product;

s4: carrying out toluene recrystallization and vacuum sublimation to obtain a compound shown in a chemical formula I;

5. a method of preparing a P-doped hole injection compound according to any one of claims 1 to 3, comprising the steps of:

s1: slowly dripping a tetrahydrofuran solution of the reactant b into a tetrahydrofuran solution of lithium hydride at the temperature of 0 ℃, then heating to room temperature for reaction for 30-60min, and then cooling to 0 ℃ again;

s2: dropwise adding a tetrahydrofuran solution of the reactant a into the solution obtained in the step S1, reacting for 15-20h at 25-30 ℃, then pouring into ice water, adjusting the pH value to 1.0-2.0, extracting for three times by using ethyl acetate, combining organic phases, washing by using saturated saline solution, water and sodium bicarbonate aqueous solution in sequence, drying by using sodium sulfate, and removing the solvent to obtain an intermediate c;

s3: dissolving the intermediate c in tetrahydrofuran, cooling to-78 ℃, dropwise adding n-butyl lithium while stirring, and keeping the reaction temperature for 15-30min after the reaction temperature is raised to room temperature;

cooling the reaction solution to-78 deg.C again and maintaining for 30-45min, and cooling the reaction solution containing I at-78 deg.C₂Adding the tetrahydrofuran solution into the reaction solution, removing the cooling bath after the addition is finished, andstirring overnight, quenching the reaction by using a saturated ammonium chloride solution, extracting an aqueous layer by using DCM, combining organic phases, washing the organic phases by using a sodium thiosulfate aqueous solution and a sodium chloride aqueous solution in sequence, drying magnesium sulfate, concentrating a solvent, then dripping the solvent into cold ethanol while stirring, and carrying out suction filtration, washing and drying on a precipitated solid to obtain an intermediate d;

s4: slowly dripping a tetrahydrofuran solution of a reactant e into a tetrahydrofuran solution of lithium hydride at the temperature of 0 ℃, then heating to room temperature for reaction for 30-60min, and then cooling to 0 ℃ again; dripping tetrahydrofuran solution of the intermediate d, reacting for 15-20h at 25 ℃, then pouring into ice water, adjusting the pH value to 1.0-2.0, extracting for three times by using ethyl acetate, combining organic phases, washing by using saturated saline solution, water and sodium bicarbonate aqueous solution in sequence, drying by using sodium sulfate, and removing the solvent to obtain an intermediate f;

s5: adding the intermediate f into tetrahydrofuran, then adding [ bis (trifluoroacetoxy) iodine ] benzene, stirring at room temperature, concentrating the solvent, dripping into cold ethanol while stirring, and performing suction filtration, washing and drying on the precipitated solid to obtain a crude product;

s6: carrying out toluene recrystallization and vacuum sublimation to obtain a compound shown in a chemical formula I;

6. a hole injection layer comprising the P-type doped hole injection compound of any of claims 1-5 and further comprising a hole transport material.

7. The hole injection layer of claim 6, wherein the doping molar ratio of the P-type doped hole injection compound to the hole transport material is 1:1 to 1: 100.

8. The hole injection layer of claim 7, wherein the difference between the HOMO level of the hole transport material and the LUMO level of the P-type doped hole injection compound is less than or equal to 0.30 eV.

9. The hole injection layer of claim 8, wherein the hole transport material is selected from triarylamine hole transport materials, spirofluorene hole transport materials, or fluorene hole transport materials.

Technical Field

The invention belongs to the field of photoelectric materials, and relates to a P-type doped hole injection compound and application thereof.

Background

Compared with the prior art, the OLED device has the advantages of low starting voltage, high luminous efficiency, high contrast, high color saturation, wide visual angle, quick response time and the like. The structure of an OLED device is generally: cathode (Cathode)/Electron Injection Layer (EIL)/Electron Transport Layer (ETL)/light emitting layer (EML)/Hole Transport Layer (HTL)/Hole Injection Layer (HIL)/Anode (Anode). Energy level matching is important for an organic electroluminescent device, however, the improvement of the device performance is limited by a plurality of problems of low hole mobility, deviation of conductivity, high injection barrier caused by poor contact with a metal electrode and the like of an organic hole transport material. Therefore, it is necessary to develop a hole injection layer having a strong reduction potential, excellent hole injection performance, and energy level matching with the hole transport layer.

It is known from the prior art that organic materials can be doped to influence their conductivity properties. The P-type dopant has the characteristics of strong oxidizing property and strong electron accepting capability, and the P-type dopant is doped into the hole transport layer through a P-type doping technology to form a P-type doped hole injection layer, so that the carrier mobility and the carrier concentration can be remarkably improved, an interface energy band can be bent, and holes can be injected in a tunneling mode. Common organic small molecule P-doped materials include HATCN, F4-TCNQ, AlPcCl, and the like.

p-type doping is typically achieved by co-doping the dopant with the hole transport material, which also has certain disadvantages: for example, the doping ratio is difficult to control accurately; under the condition of high-concentration doping, the co-doped layer has the problems of uneven co-doped film caused by the phenomena of aggregation, even phase separation and the like of dopant molecules. The hole injection layer containing the p-type doped hole injection compound provided by the invention can obtain an organic electroluminescent device with low driving voltage and high luminous efficiency, and presumably because the p-type doped hole injection compound provided by the invention is grafted with an electron-withdrawing group and matched with double bonds, a region for receiving electrons can be expanded to a larger range, and at the moment, a large number of electrons jump from the HOMO energy level of a hole transport material to the LUMO energy level of the doping material, so that the hole transport material forms more free holes, and the luminous efficiency of the device is improved.

Disclosure of Invention

The invention provides a hole injection compound and application thereof, and an organic light-emitting element doped with the compound in a hole transport layer has low starting voltage and can effectively improve the service life of the device.

In order to achieve the purpose, the invention adopts the following technical scheme:

a P-type doped hole injection compound having the structure of formula I:

wherein R is₁＝R₇；R₂＝R₆；R₄＝R₁₀；R_5＝R₉；R₃＝R₈(ii) a And, R₁≠R₄；R₂≠R₅；

Or the like, or, alternatively,

R₁＝R₄＝R₇＝R₉；R₂＝R₅＝R₆＝R₁₀(ii) a And, R₃＝R₈；

R₁-R₁₀Independently of one another, from hydrogen, deuterium, halogen, cyano, nitro, trifluoromethyl, hydroxyl, sulfonic acid, phosphoric acid, OCF₃、SCF₃C1-C10 alkoxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl;

and, R₁-R₁₀At least one is not hydrogen.

Preferably, the halogen is selected from fluorine, chlorine, bromine or iodine; preferably fluorine and chlorine; most preferably fluorine.

Preferably, the "substituted" group in said "substituted or unsubstituted" is selected from one or more combinations of deuterium, halogen, nitrile group, hydroxyl group, carbonyl group or nitro group.

Preferably, said R is₁-R₁₀Independently selected from fluorine, trifluoromethyl, nitrile group, nitro group and CH₃O、OCF₃。

The specific hole-injecting compound provided by the present invention is preferably:

the invention also discloses a preparation method of the P-type doped hole injection compound shown in the chemical formula I, which comprises the following steps:

s1: slowly dripping the tetrahydrofuran solution of the reactant B into the tetrahydrofuran solution of lithium hydride at the temperature of 0 ℃, then heating to room temperature for reaction for 30-60min, and then cooling to 0 ℃ again;

s2: dropwise adding a tetrahydrofuran solution of the reactant A into the solution obtained in the step S1, reacting for 15-20h at 25-30 ℃, then pouring into ice water, adjusting the pH value to 1.0-2.0, extracting for three times by using ethyl acetate, combining organic phases, washing by using saturated saline solution, water and sodium bicarbonate aqueous solution in sequence, drying by using sodium sulfate, and removing the solvent to obtain an intermediate C;

s3: adding the intermediate C into tetrahydrofuran, adding [ bis (trifluoroacetoxy) iodine ] benzene, stirring at room temperature, concentrating the solvent, dripping into cold ethanol while stirring, and performing suction filtration, washing and drying on the precipitated solid to obtain a crude product;

s4: carrying out toluene recrystallization and vacuum sublimation to obtain a compound shown in a chemical formula I;

the synthetic route is as follows:

preferably, the mole ratio of the reactant A, the reactant B and the lithium hydride is 1: (4-5): (4-5);

the molar ratio of the intermediate C to the [ bis (trifluoroacetoxy) iodine ] benzene is 1 (2.0-2.5), and the using amount of tetrahydrofuran is 0.5M-1.5M.

The invention also discloses another preparation method of the compound shown in the chemical formula I, which comprises the following steps:

s1: slowly dripping a tetrahydrofuran solution of the reactant b into a tetrahydrofuran solution of lithium hydride at the temperature of 0 ℃, then heating to room temperature for reaction for 30-60min, and then cooling to 0 ℃ again;

s2: dropwise adding a tetrahydrofuran solution of the reactant a into the solution obtained in the step S1, reacting for 15-20h at 25-30 ℃, then pouring into ice water, adjusting the pH value to 1.0-2.0, extracting for three times by using ethyl acetate, combining organic phases, washing by using saturated saline solution, water and sodium bicarbonate aqueous solution in sequence, drying by using sodium sulfate, and removing the solvent to obtain an intermediate c;

s3: dissolving the intermediate c in tetrahydrofuran, cooling to-78 deg.C, adding n-butyl lithium dropwise under stirring, heating to room temperature, maintaining for 15-30min, cooling to-78 deg.C, maintaining for 30-45min, and adding I at-78 deg.C₂Adding the tetrahydrofuran solution into the reaction solution, removing the cold bath after the addition is finished, stirring overnight, quenching the reaction by using a saturated ammonium chloride solution, extracting a water layer by using DCM, combining organic phases, washing the organic phases by using a sodium thiosulfate aqueous solution and a sodium chloride aqueous solution in sequence, drying the magnesium sulfate, concentrating the solvent, then dripping the organic phases into cold ethanol while stirring, and carrying out suction filtration, washing and drying on the separated solid to obtain an intermediate d;

s4: slowly dripping a tetrahydrofuran solution of a reactant e into a tetrahydrofuran solution of lithium hydride at the temperature of 0 ℃, then heating to room temperature for reaction for 30-60min, and then cooling to 0 ℃ again; dripping tetrahydrofuran solution of the intermediate d, reacting for 15h at 25-30 ℃, then pouring into ice water, adjusting the pH value to 1.0-2.0, extracting for three times by using ethyl acetate, combining organic phases, washing by using saturated saline solution, water and sodium bicarbonate aqueous solution in sequence, drying by using sodium sulfate, and removing the solvent to obtain an intermediate f;

s5: adding the intermediate f into tetrahydrofuran, then adding [ bis (trifluoroacetoxy) iodine ] benzene, stirring at room temperature, concentrating the solvent, dripping into cold ethanol while stirring, and performing suction filtration, washing and drying on the precipitated solid to obtain a crude product;

s6: carrying out toluene recrystallization and vacuum sublimation to obtain a compound shown in a chemical formula I;

the synthetic route is as follows:

preferably, the molar ratio of the reactant a to the reactant b to the lithium hydride is 1 (1-1.5) to (1-1.5); the usage amount of tetrahydrofuran is 0.5M-1.5M;

the intermediate c is reacted with n-butyllithium, I₂In a molar ratio of 1: (2-2.5): (2.5-3.5), the usage amount of tetrahydrofuran is 0.5-1.5M;

the molar ratio of the intermediate d to the reactant e and the lithium hydride is 1: (2-2.5): (2-2.5), the using amount of tetrahydrofuran is 0.5M-1.5M;

the molar ratio of the intermediate f to the [ bis (trifluoroacetoxy) iodine ] benzene is 1 (2.0-2.5), and the using amount of tetrahydrofuran is 0.5M-1.5M.

The invention also discloses a hole injection layer, which comprises the P-type doped hole injection compound and a hole transport material.

Preferably, the doping molar ratio of the P-type doped hole injection compound to the hole transport material is 1:1 to 1:100, such as 1:2, 1:10, 1:20, 1: 50.

Preferably, the hole transport material comprises triarylamine hole transport materials, spirofluorene hole transport materials and fluorene hole transport materials. Such as NPB, TPD, m-MTDATA, etc.

The hole injection layer provided by the invention can be applied to display devices and lighting devices. Such as a display device for a smartphone, tablet, laptop, PC, TV or vehicle, or a lighting device such as an indoor or outdoor lighting device.

Compared with the prior art, the organic electroluminescent device prepared by the hole injection layer doped with the p-type doped hole injection compound provided by the invention has lower driving voltage, higher luminous efficiency and longer service life.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.