阅读说明：本技术 一种有机电致发光化合物及其应用 (Organic electroluminescent compound and application thereof ) 是由 崔彩 丁兴立 于 2020-12-25 设计创作，主要内容包括：本发明公开了一种有机电致发光化合物及其应用,所述有机电致发光化合物具有如式Ⅰ所示结构：,其中,Ar-1、Ar-2各自独立的代表具有C-6～C-(60)的芳香族或C-6～C-(60)的杂芳香族环系。一种OLED器件用空穴传输层,所述空穴传输层包括上述的有机电致发光化合物。一种OLED器件,所述OLED器件包括阳极、阴极以及位于所述阳极和所述阴极之间的至少一层有机薄膜层；所述有机薄膜层包括空穴传输层,还包括空穴注入层、电子阻挡层、空穴阻挡层、发光层、电子传输层和电子注入层中的任意一种或至少两种的组合；所述空穴传输层为上述的OLED器件用空穴传输层。本发明有机电致发光化合物具有良好空穴传输性能以及稳定性,可用于制造工作寿命较高的OLED器件。(The invention discloses an organic electroluminescent compound and application thereof, wherein the organic electroluminescent compound has a structure shown as a formula I: wherein Ar is 1 、Ar 2 Each independently represents a group having C 6 ～C 60 Aromatic or C 6 ～C 60 A heteroaromatic ring system of (a). A hole transport layer for an OLED device, the hole transport layer comprising the organic electroluminescent compound described above. An OLED device comprising an anode, a cathode and at least one organic thin film layer between the anode and the cathode; the organic thin film layer comprises a hole transport layer and also comprises any one or the combination of at least two of a hole injection layer, an electron blocking layer, a hole blocking layer, a light emitting layer, an electron transport layer and an electron injection layer; the hole transport layer is the hole transport layer for the OLED device. The organic electroluminescent compound has good hole transport performance and stability, and can be used for manufacturing OLED devices with longer service life.)

1. An organic electroluminescent compound characterized by: the organic electroluminescent compound has a structure shown in a formula I:

wherein Ar is₁、Ar₂Each independently represents a group having C₆～C₆₀Aromatic or C₆～C₆₀A heteroaromatic ring system of (a).

2. The organic electroluminescent compound according to claim 1, wherein: wherein Ar is₁、Ar₂Each independently represents benzene, naphthalene, phenanthrene, fluorene, dibenzofuran or dibenzothiophene carbazole or combinations thereof.

3. The organic electroluminescent compound according to claim 1 or 2, characterized in that: the organic electroluminescent compound is selected from one or more of the formulas H1-H30:

4. a hole transport layer for an OLED device, comprising: the hole transport layer includes the organic electroluminescent compound according to any one of claims 1 to 3.

5. An OLED device, characterized by: the OLED device comprises an anode, a cathode and at least one organic thin film layer positioned between the anode and the cathode; the organic thin film layer comprises a hole transport layer and also comprises any one or the combination of at least two of a hole injection layer, an electron blocking layer, a hole blocking layer, a light emitting layer, an electron transport layer and an electron injection layer;

the hole transport layer is the hole transport layer for the OLED device as claimed in claim 4.

6. An electronic device, characterized in that it comprises an OLED device according to claim 5.

Technical Field

The invention belongs to the technical field of organic electroluminescent materials, and particularly relates to an organic electroluminescent compound and application thereof.

Background

An electroluminescent device (EL device) is a self-luminous device, which has advantages of a wider viewing angle, a larger contrast ratio, and a faster response time. Currently, the first organic EL device is manufactured by Eastman Kodak (Eastman Kodak) by using small aromatic diamine molecules and metal aluminum complexes as materials for forming a light emitting layer [ applied physics (appl. phys. lett.) 51,913,1987 ].

In the prior art, hole transport materials are usually used in the hole transport layer or the hole injection layer, and the hole transport materials commonly used are triarylamine derivatives containing at least two triarylamine groups or at least one triarylamine group and at least one carbazole group; the above compounds are usually derived from diarylamino substituted triphenylamines (TPA type), diarylamino substituted biphenyl derivatives (TAD type) or combinations of these base compounds. The use of the above compounds in fluorescent OLEDs, or phosphorescent OLEDs, particularly in organic electroluminescent devices, requires improvements in operating voltage, efficiency, lifetime, and thermal stability during sublimation.

Disclosure of Invention

The invention aims to provide an organic electroluminescent compound and application thereof, wherein the organic electroluminescent compound has good hole transport performance and stability, and can be used for manufacturing OLED devices with longer service life.

One of the objects of the present invention is to provide an organic electroluminescent compound having a structure represented by formula i:

wherein Ar is₁、Ar₂Each independently represents a group having C₆～C₆₀Aromatic or C₆～C₆₀A heteroaromatic ring system of (a).

The technical scheme of further improvement in the technical scheme is as follows:

in the above scheme, Ar is₁、Ar₂Each independently represents benzene, naphthalene, phenanthrene, fluorene, dibenzofuran or dibenzothiophene carbazole or combinations thereof.

It is a second object of the present invention to provide a hole transport layer for an OLED device comprising an organic electroluminescent compound according to the first object.

The invention also aims to provide an OLED device, which comprises an anode, a cathode and at least one organic thin film layer positioned between the anode and the cathode; the organic thin film layer comprises a hole transport layer and also comprises any one or the combination of at least two of a hole injection layer, an electron blocking layer, a hole blocking layer, a light emitting layer, an electron transport layer and an electron injection layer;

the hole transport layer is the hole transport layer for the OLED device.

It is a fourth object of the present invention to provide an electronic device comprising the OLED device of the second object.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

1. the organic electroluminescent compound provided by the invention has a 7-membered ring structure, and the organic electroluminescent compound is endowed with higher glass transition temperature and good thermal stability through the design of a molecular structure and a substituent group, so that the organic electroluminescent compound is prevented from being degraded in a high-temperature deposition process; and the hole transport performance and stability of the organic light emitting diode serving as a hole transport layer are remarkably improved, so that an OLED device containing the organic light emitting diode has high light emitting efficiency and long service life, and the power efficiency and the power consumption are improved.

2. The organic electroluminescent compound is suitable for fluorescent OLED devices and phosphorescent OLED devices, and is particularly suitable for phosphorescent OLED devices.

Detailed Description

One of the objects of the present invention is to provide an organic electroluminescent compound having a structure represented by formula i:

wherein, Ar is₁、Ar₂Each independently represents a group having C₆～C₆₀Aromatic or C₆～C₆₀A heteroaromatic ring system of (a).

The organic electroluminescent compound has higher glass transition temperature and good thermal stability through the design of a molecular structure and a substituent group, and is prevented from being degraded in a high-temperature deposition process; and the hole transport performance and stability of the organic light emitting diode serving as a hole transport layer are remarkably improved, so that an OLED device containing the organic light emitting diode has high light emitting efficiency and long service life, and the power efficiency and the power consumption are improved.

The organic electroluminescent compound is selected from one or more of the formulas H1-H30:

it is a second object of the present invention to provide a hole transport layer for an OLED device comprising an organic electroluminescent compound according to the first object.

The invention also aims to provide an OLED device, which comprises an anode, a cathode and at least one organic thin film layer positioned between the anode and the cathode; the organic thin film layer comprises a hole transport layer and also comprises any one or the combination of at least two of a hole injection layer, an electron blocking layer, a hole blocking layer, a light emitting layer, an electron transport layer and an electron injection layer;

the hole transport layer is the hole transport layer for the OLED device.

It is a fourth object of the present invention to provide an electronic device comprising the OLED device of the second object.

The invention is further described below with reference to the following examples:

the following examples relate to compounds having the following structures:

synthesis examples:

example 1: this example provides an organic electroluminescent compound H1, which has the following structure:

the preparation method of the H1 comprises the following steps:

(1) synthesis H1:

into a 250ml three-necked flask, M-1(5g, 0.014mol) and 3- (4-bromophenyl) -9-phenylcarbazole (5.5g, 0.014mol) were charged, 100ml of toluene was added, and sodium t-butoxide (1.7g, 0.018mol), Pd, and the mixture was added under stirring₂(dba)₃(0.064g, 0.00007mol), replacing nitrogen, adding 0.28g of tri-tert-butylphosphine 10% toluene solution, starting heating, slowly heating to 80 ℃ (keeping nitrogen protection in the reaction process), reacting for 2 hours, and detecting by HPLC (M-1)<1 percent), stopping the reaction and cooling to room temperature. After the reaction is finished, cooling to 25 ℃, washing with salt water for 2 times, adding anhydrous sodium sulfate into the organic phase, and drying; performing column chromatography with toluene as eluent; concentrating to obtain crude product, recrystallizing with toluene to obtain product H1 (7.6 g), with purity>99% and yield 80%.

The compound H1 is subjected to mass spectrometric detection, and m/z: 676.

the compound H1 was subjected to nuclear magnetic detection and the data was resolved as follows:

¹HNMR(300MHz，CDCl₃)δ8.55(d，1H)，δ7.99(d，1H)，δ7.94～7.89(m，3H)，δ7.78～7.75(m，4H)，δ7.65～7.60(m，4H)，δ7.58～7.50(m，6H)，δ7.49～7.41(m，4H)，δ7.37～7.35(m，3H)δ7.24～7.16(m，4H)，δ1.63(s，6H)。

example 2: this example provides an organic electroluminescent compound H2, which has the following structure:

the preparation method of the H2 comprises the following steps:

(1) synthesis H2:

into a 250ml three-necked flask, M-2(5g, 0.014mol) and 3- (4-bromophenyl) -9-phenylcarbazole (5.5g, 0.014mol) were charged, 100ml of toluene was added, and sodium t-butoxide (1.7g, 0.018mol), Pd, and the mixture was added under stirring₂(dba)₃(0.064g, 0.00007mol), replacing nitrogen, adding 0.28g of tri-tert-butylphosphine 10% toluene solution, starting heating, slowly heating to 80 ℃ (keeping nitrogen protection in the reaction process), reacting for 2 hours, and detecting by HPLC (M-2)<1 percent), stopping the reaction and cooling to room temperature. After the reaction is finished, cooling to 25 ℃, washing with salt water for 2 times, adding anhydrous sodium sulfate into the organic phase, and drying; performing column chromatography with toluene as eluent; concentrating to obtain crude product, recrystallizing with toluene to obtain product H2 (7.6 g), with purity>99% and yield 80%.

The compound H2 is subjected to mass spectrometric detection, and m/z: 676.

the compound H2 was subjected to nuclear magnetic detection and the data was resolved as follows:

¹HNMR(300MHz，CDCl₃)δ8.55(d，1H)，δ7.99(d，1H)，δ7.94～7.89(m，3H)，δ7.78～7.75(m，4H)，δ7.65～7.35(m，16H)δ7.24～7.16(m，4H)，δ6.91(d,1H)δ1.63(s，6H)。

example 3: this example provides an organic electroluminescent compound H4, which has the following structure:

the preparation method of the H4 comprises the following steps:

(1) synthesis H4:

to a 250ml three-necked flask, M-3(5.2g, 0) was added014mol) and 3- (4-bromophenyl) -9-phenylcarbazole (5.5g, 0.014mol), 100ml of toluene was added, and sodium t-butoxide (1.7g, 0.018mol), Pd were added with stirring₂(dba)₃(0.064g, 0.00007mol), replacing nitrogen, adding 0.28g of tri-tert-butylphosphine 10% toluene solution, starting heating, slowly heating to 80 ℃ (keeping nitrogen protection in the reaction process), reacting for 2 hours, and detecting by HPLC (M-3)<1 percent), stopping the reaction and cooling to room temperature. After the reaction is finished, cooling to 25 ℃, washing with salt water for 2 times, adding anhydrous sodium sulfate into the organic phase, and drying; performing column chromatography with toluene as eluent; concentrating to obtain crude product, recrystallizing with toluene to obtain product H4 (7.7 g), with purity>99% and yield 80%.

The compound H4 is subjected to mass spectrometric detection, and m/z: 690.

the compound H4 was subjected to nuclear magnetic detection and the data was resolved as follows:

¹HNMR(300MHz，CDCl₃)δ8.55(d，1H)，δ8.22(s，1H)，δ7.99～7.89(m，4H)，δ7.79～7.77(m，3H)，δ7.65～7.35(m，14H)δ7.31～7.16(m，5H),δ1.63(s，6H)。

example 4: this example provides an organic electroluminescent compound H11, which has the following structure:

the preparation method of the H11 comprises the following steps:

(1) synthesis H11:

into a 250ml three-necked flask, M-2(5g, 0.014mol) and 2-bromo-9, 9' -spirobifluorene (5.5g, 0.014mol) were charged, 100ml of toluene was added, and sodium t-butoxide (1.7g, 0.018mol), Pd, and the mixture was added under stirring₂(dba)₃(0.064g, 0.00007mol), nitrogen gas was replaced, 0.28g of a 10% toluene solution of tri-t-butylphosphine was added, heating was started, and the temperature was gradually increased to 80 ℃ (the reaction was maintained during the reaction)Nitrogen protection), reacting for 2 hours, and detecting by HPLC (M-2)<1 percent), stopping the reaction and cooling to room temperature. After the reaction is finished, cooling to 25 ℃, washing with salt water for 2 times, adding anhydrous sodium sulfate into the organic phase, and drying; performing column chromatography with toluene as eluent; concentrating to obtain crude product, recrystallizing with toluene to obtain product H11 (7.6 g), with purity>99% and yield 80%.

The compound H11 is subjected to mass spectrometric detection, and m/z: 673.

the compound H11 was subjected to nuclear magnetic detection and the data was resolved as follows:

¹HNMR(300MHz，CDCl₃)δ7.90～7.86(m，5H)，δ7.78～7.75(m，3H)，δ7.65(d，1H)，δ7.55～7.16(m，19H)，δ7.91(d，1H)，δ1.63(s，6H)。

example 5: this example provides an organic electroluminescent compound H17, which has the following structure:

the preparation method of the H17 comprises the following steps:

(1) synthesis H17:

into a 250ml three-necked flask, M-1(5g, 0.014mol) and 4-bromo-9, 9' -spirobifluorene (5.5g, 0.014mol) were charged, 100ml of toluene was added, and sodium t-butoxide (1.7g, 0.018mol), Pd, and the mixture was added under stirring₂(dba)₃(0.064g, 0.00007mol), replacing nitrogen, adding 0.28g of tri-tert-butylphosphine 10% toluene solution, starting heating, slowly heating to 80 ℃ (keeping nitrogen protection in the reaction process), reacting for 2 hours, and detecting by HPLC (M-2)<1 percent), stopping the reaction and cooling to room temperature. After the reaction is finished, cooling to 25 ℃, washing with salt water for 2 times, adding anhydrous sodium sulfate into the organic phase, and drying; performing column chromatography with toluene as eluent; concentrating to obtain crude product, recrystallizing with toluene to obtain product H17 (7.6 g), with purity>99％，The yield thereof was found to be 80%.

The compound H17 is subjected to mass spectrometric detection, and m/z: 673.

the compound H17 was subjected to nuclear magnetic detection and the data was resolved as follows:

1HNMR(300MHz，CDCl3)δ7.90～7.86(m，5H)，δ7.78～7.75(m，3H)，δ7.65(d，2H)，δ7.58～7.16(m，19H)，δ1.63(s，6H)。

example 6: this example provides an organic electroluminescent compound H26, which has the following structure:

the preparation method of the H26 comprises the following steps:

(1) synthesis H26:

into a 250ml three-necked flask, M-1(5g, 0.014mol) and 4-bromo-9, 9-diphenylfluorene (5.6g, 0.014mol) were charged, 100ml of toluene was added, and sodium t-butoxide (1.7g, 0.018mol) and Pd were added under stirring₂(dba)₃(0.064g, 0.00007mol), replacing nitrogen, adding 0.28g of tri-tert-butylphosphine 10% toluene solution, starting heating, slowly heating to 80 ℃ (keeping nitrogen protection in the reaction process), reacting for 2 hours, and detecting by HPLC (M-2)<1 percent), stopping the reaction and cooling to room temperature. After the reaction is finished, cooling to 25 ℃, washing with salt water for 2 times, adding anhydrous sodium sulfate into the organic phase, and drying; performing column chromatography with toluene as eluent; concentrating to obtain crude product, recrystallizing with toluene to obtain product H26 (7.6 g), with purity>99% and yield 80%.

The compound H26 is subjected to mass spectrometric detection, and m/z: 675.

the compound H26 was subjected to nuclear magnetic detection and the data was resolved as follows:

¹HNMR(300MHz，CDCl₃)δ7.90(m，2H)，δ7.78～7.75(m，3H)，δ7.65(d，2H)，δ7.56～7.38(m，7H)，δ7.28～7.10(m，17H)，δ1.63(s，6H)。

the following are examples of applications of the organic compounds of the present invention in OLED devices:

application example 1: the application example provides an OLED device, and the preparation method of the OLED device comprises the following steps:

(1) a transparent electrode Indium Tin Oxide (ITO) film (15 Ω/sq, Samsung Corning, Samsung) on a glass substrate for an Organic Light Emitting Diode (OLED) device was sequentially ultrasonically cleaned with trichloroethylene, acetone, ethanol, and distilled water, and then stored in isopropyl alcohol; and mounting the ITO substrate on a substrate clamp of vacuum vapor deposition equipment.

(2) The compound HIL was introduced into the chamber of a vacuum vapor deposition apparatus, and then the chamber pressure of the apparatus was controlled to reach 10 deg.C^-6And applying a current to the chamber to evaporate the introduced substances, thereby forming a hole injection layer having a thickness of 60nm on the ITO substrate.

(3) The organic electroluminescent compound H1 provided by the present invention was introduced into another chamber of a vacuum vapor deposition apparatus, and evaporation was performed by applying a current to the chamber, thereby forming a hole transport layer having a thickness of 20nm on the hole injection layer.

(4) Introducing compound CBP into one chamber of a vacuum vapor deposition apparatus as a host material and compound D-1 into the other chamber as a dopant; the two materials were evaporated at different rates and deposited at a doping amount of 15 wt% (based on the total weight of the host material and the dopant) to form a light-emitting layer having a thickness of 30nm on the hole transport layer.

(5) Introducing compound ETL into one chamber and 8-hydroxyquinolinolato lithium (lithium quinolate) into the other chamber; both materials were evaporated at the same rate and deposited at doping amounts of 50 wt%, respectively, to form an electron transport layer having a thickness of 30nm on the light emitting layer.

(6) 8-hydroxyquinolinolato lithium with a thickness of 2nm was deposited on the electron transport layer as an electron injection layer EIL.

(7) Depositing an Al cathode with the thickness of 150nm on the electron injection layer by another vacuum vapor deposition device; and obtaining the OLED device.

All materials used in the preparation of the OLED devices described above were purified by vacuum sublimation under 10 "6 torr conditions prior to use.

Application example 2: the present application example provides an OLED device, which is different from application example 1 in that: h1 in step (3) is replaced by H2.

Application example 3: the present application example provides an OLED device, which is different from application example 1 in that: h1 in step (3) is replaced by H4.

Application example 4: the present application example provides an OLED device, which is different from application example 1 in that: h1 in step (3) is replaced by H11.

Application example 5: the present application example provides an OLED device, which is different from application example 1 in that: h1 in step (3) is replaced by H17.

Application example 6: the present application example provides an OLED device, which is different from application example 1 in that: h1 in step (3) is replaced by H26.

Application example 7: the present application example provides an OLED device, which is different from application example 1 in that: h1 in step (3) is replaced by H29.

Comparative example 1: the present comparative example provides an OLED device, which is different from application example 1 in that: h1 in step (3) was replaced with htl (npb).

Performance testing of OLED devices

The OLED-1000 multichannel accelerated aging life and light color performance analysis system produced in Hangzhou distance is used for testing the LT90 of the driving voltage, the current efficiency and the life of the OLED device provided in application examples 1-7 and comparative example 1; here, LT90 indicates the time required for the luminance to decrease to 90% of the original luminance with the current density kept constant.

The specific test results are shown in table 1:

TABLE 1 OLED device Performance test results

As can be seen from table 1, the organic electroluminescent compounds according to the present invention have superior properties compared to the organic electroluminescent compounds of the prior art, and thus the organic electroluminescent device provided by the present invention has high luminous efficiency and long operating life; also, the organic electroluminescent device requires a low driving voltage, thereby improving power efficiency and power consumption.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.