CN111675701A - An organic electroluminescent compound and organic electroluminescent device based on triphenylamine structure - Google Patents

Abstract

The invention discloses an organic electroluminescent compound and an organic electroluminescent device based on a triphenylamine structure, and the structural formula is as follows:

Ar1, Ar2 are identical or different, each independently is an aryl group of C6-C30, a heteroaryl group of C5-C30, and at least one hydrogen in the aryl group of described C6-C30 and the heteroaryl group of C5-C30 can be replaced by C1 -C4 alkyl, C1-C4 deuterated alkyl, phenyl, cyano substituted or unsubstituted; L is C6-C30 arylene, and L is not phenylene; m, n are independently 1 or 2, as an organic electroluminescent material, the device efficiency and service life are greatly improved, and it has a very broad application prospect.

Description

An organic electroluminescent compound based on triphenylamine structure and organic electroluminescence device

technical field

The invention relates to the technical field of organic electroluminescence, in particular to an organic electroluminescence compound based on a triphenylamine structure and an organic electroluminescence device.

Background technique

As a new type of flat panel display, organic electroluminescent device (Organic Light Emitting Display, referred to as OLED), compared with liquid crystal display (Liquid Crystal Display, referred to as LCD), has the advantages of thin, light, wide viewing angle, active emission, continuously adjustable emission color. , low cost, fast response speed, low energy consumption, low driving voltage, wide operating temperature range, simple production process, high luminous efficiency and flexible display, etc., have received great attention from the industry and the scientific community.

The light-emitting principle of organic electroluminescent devices is that when an electric field is applied to the cathode and anode, the holes on the anode side and the electrons on the cathode side will move to the light-emitting layer, combine in the light-emitting layer to form excitons, and the excitons are in the excited state to release energy outward. The process of releasing energy from the excited state to releasing energy from the ground state emits light. Since 1987 Kodak Corporation of the United States reported organic molecule electroluminescence and Cambridge University of England reported polymer electroluminescence in 1990, countries around the world have carried out research and development. This kind of material has the advantages of simple structure, high yield, low cost, active light emission, fast response speed, high fractional rate, and has the properties of low driving voltage, all-solid state, non-vacuum, anti-shock, low-temperature resistance (-40℃), etc. . In recent years, OLED materials have been widely used in the field of smartphones, and are considered to be a new technology that is most likely to replace liquid crystal displays in the future, attracting great attention.

At present, the research on improving the performance of organic electroluminescent devices at home and abroad includes: reducing the driving voltage of the device, improving the luminous efficiency of the device, and improving the service life of the device. In order to realize the continuous improvement of the performance of organic electroluminescent devices, it is not only necessary to innovate the structure and fabrication process of organic electroluminescent devices, but also to continuously research and innovate organic electro-optical functional materials to create higher-performance organic electroluminescent devices. Functional Materials.

In order to achieve excellent light-emitting properties of organic electroluminescent devices, the materials constituting the organic material layer, such as hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer and Luminescent materials such as hosts and/or dopants should be stable and have good efficiency. However, the development of organic material layer materials for organic electroluminescent devices is still far from satisfactory so far, and thus new materials need to be continuously developed.

SUMMARY OF THE INVENTION

Purpose of the invention: In view of the above technical problems, the present invention provides an organic electroluminescent compound and an organic electroluminescent device based on a triphenylamine structure.

In order to achieve the above-mentioned purpose of the invention, the technical scheme adopted in the present invention is as follows:

An organic electroluminescent compound based on triphenylamine structure, its structural formula is as follows:

Ar1 and Ar2 are the same or different, and are each independently a C6-C30 aryl group, a C5-C30 heteroaryl group, and at least one hydrogen in the C6-C30 aryl group and C5-C30 heteroaryl group may be replaced by C1 -C4 alkyl, C1-C4 deuterated alkyl, phenyl, cyano substituted or unsubstituted;

L is a C6-C30 arylene group, and L is not a phenylene group;

m and n are each independently 1 or 2.

Further, Ar1 and Ar2 are the same or different, and each independently is phenyl, biphenyl, pyridyl, pyrimidinyl, triazinyl, anthracenyl, naphthyl, phenanthryl, oxyfluorenyl, thiofluorenyl, carbazole base, N-phenylcarbazolyl, fluorenyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, 9-methyl-9-phenylfluorenyl, 9,9'-spiro difluorenyl;

The phenyl, biphenyl, pyridyl, pyrimidinyl, triazinyl, anthracenyl, naphthyl, phenanthryl, oxyfluorenyl, thiofluorenyl, carbazolyl, N-phenylcarbazolyl, fluorenyl , 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, 9-methyl-9-phenylfluorenyl, 9,9'-spirobifluorenyl are unsubstituted or at least one of them Hydrogen is replaced by deuterium, C1-C4 alkyl, C1-C4 deuterated alkyl, phenyl, cyano.

Further, when both Ar1 and Ar2 are phenyl groups, m and n are not 1 at the same time.

Further, L is a naphthylene group or an anthracene group.

Further, the structural formula of the organic electroluminescent compound is any one of the following:

Further, its structural formula is any one of the following:

Further, the organic electroluminescent compound is any one of the following compounds:

The application of the above organic electroluminescent compound in the preparation of organic electroluminescent device.

An organic electroluminescence device, comprising an anode and a cathode arranged oppositely, and a functional layer arranged between the anode and the cathode; the functional layer contains the above-mentioned organic electroluminescence compound.

Further, the functional layer includes: a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, and the hole injection layer and the hole transport layer , At least one layer of the electron blocking layer, the light emitting layer, the hole blocking layer, the electron transport layer, and the electron injection layer contains the above-mentioned organic electroluminescent compound.

Further, at least one of the hole transport layer, the electron blocking layer, and the light-emitting layer contains the above-mentioned organic electroluminescent compound.

An OLED display device contains the above organic electroluminescent device.

The room temperature in the present invention is all 25±5°C.

Beneficial effects of the present invention:

The organic electroluminescent compound designed in the present invention increases the hole mobility of the material molecule due to the introduction of the conjugated structure of the naphthyl group and the anthracene group into the molecule, thereby effectively reducing the voltage of the light-emitting device. At the same time, the introduction of naphthyl and anthracene groups increases the torque, steric hindrance and thermal stability of the material molecule. The increase in torque and steric hindrance effectively increases the triplet energy level (T1) of the material molecule, effectively avoiding the energy from The reverse transfer from the light-emitting layer to the electron blocking layer greatly improves the efficiency and life of the device. The improved thermal stability further increases the lifetime of the device.

Description of drawings

1 is a schematic structural diagram of an organic electroluminescence device provided by the present invention;

The numbers in the figure represent:

1-anode, 2-hole injection layer, 3-hole transport layer, 4-electron blocking layer, 5-light emitting layer, 6-hole blocking layer, 7-electron transport layer, 8-electron injection layer, 9- cathode.

FIG. 2 is a DSC chart of the organic electroluminescent compound 1 of the present invention. As can be seen from FIG. 2 , the glass transition temperature Tg value of the organic electroluminescent compound 1 of the present invention is 153.02° C.;

FIG. 3 is a TGA diagram of the organic electroluminescent compound 1 of the present invention. As can be seen from FIG. 3 , the Td value of the thermal weight loss temperature of the organic electroluminescent compound 1 of the present invention is 379.50° C.;

Figure 4 shows the luminescence lifetime curves of the organic electroluminescent devices prepared in Application Example 1 and Comparative Example 1. It can be seen from Figure 4 that the luminescence lifetime T97% of the organic electroluminescent devices prepared in Application Example 1 and Comparative Example is 344h, respectively. , 301h.

FIG. 5 is an HNMR chart of the organic electroluminescent compound 1 of the present invention.

Detailed ways

Embodiments of the various aspects are further illustrated and described below. It should be understood that the description herein is not intended to limit the claims to the particular aspects described. On the contrary, the intention is to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the present disclosure as defined by the appended claims.

As used herein, a "Ca to Cb" hydrocarbyl group is defined as a hydrocarbyl group having a carbon number of "a" (inclusive) to "b" (inclusive). As used herein, "a and/or b" means "a" or "b" or "a and b".

As used herein, in "substituted" or "unsubstituted", the term "substituted" means that at least one hydrogen in the group is combined with a deuterium, hydrocarbyl, hydrocarbyl derivative, halogen, or cyano group (-CN) realignment. The term "unsubstituted" means that at least one hydrogen in the group is not recoordinated with a deuterium, hydrocarbyl, hydrocarbyl derivative, halogen, or cyano group (-CN). Examples of hydrocarbyl or hydrocarbon derivative groups may include C1 to C30 alkyl, C2 to C30 alkenyl, C2 to C30 alkynyl, C6 to C30 aryl, C5 to C30 heteroaryl, C1 to C30 alkylamino, C6 to C30 C30 arylamino, C6 to C30 heteroarylamino, C6 to C30 arylheteroarylamino, etc., but not limited thereto.

If the specific conditions are not indicated in the examples, it is carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used without the manufacturer's indication are conventional products that can be purchased from the market.

Example 1:

The preparation method of organic electroluminescent compound 1 is as follows:

S1:

Under nitrogen protection, compound 1-a (10g, 384.47g/mol, 26.01mmol), compound 1-b (1eq, 8.41g, 323.18g/mol, 26.01mmol), sodium tert-butoxide (1.1eq, 2.75g) were combined , 96.1g/mol, 28.61mmol), tris(dibenzylideneacetone)dipalladium (0.05eq, 1.19g, 915g/mol, 1.3mmol), tri-tert-butylphosphine (0.05eq, 0.26g, 202.32g/ mol, 1.3 mmol) and 100 ml of toluene were added to the reaction flask, and after the addition was completed, the temperature was raised to reflux for 8 h. After the reaction was completed, it was naturally cooled to room temperature, 100 mL of water was added, stirred for 30 min, and filtered through diatomaceous earth to obtain an organic phase. The phase was dried with anhydrous magnesium sulfate and then spin-dried. After purification by column chromatography, compound 1-c (8.66 g, yield 53.1%) was obtained. ESI-MS (m/z) (M+): theoretical value 626.74, measured value 626.88.

S2:

Under nitrogen protection, compound 1-c (5g, 626.74g/mol, 7.98mmol), compound 1-d (1eq, 1.86g, 233.10g/mol, 7.98mmol), sodium tert-butoxide (1.1eq, 0.84g) were combined , 96.1g/mol, 8.78mmol), tris(dibenzylideneacetone)dipalladium (0.05eq, 0.37g, 915g/mol, 0.4mmol), tri-tert-butylphosphine (0.05eq, 0.08g, 202.32g/ mol, 0.4mmol) and 50ml of toluene were added to the reaction flask, the temperature was raised to reflux for 8h after the addition of materials, and after the reaction was completed, it was naturally cooled to room temperature, 50mL of water was added, stirred for 30min, and the organic phase was obtained after filtration through diatomaceous earth. The phase was dried with anhydrous magnesium sulfate and then spin-dried. After purification by column chromatography, organic electroluminescent compound 1 (3.15 g, yield 50.6%) was obtained, ESI-MS (m/z) (M+): Theoretical value 778.94, Measured value 778.54, elemental analysis results (molecular formula C58H38N2O): theoretical value C, 89.43; H, 4.92; N, 3.60; O, 2.05; found value C, 89.44; H, 4.92; N, 3.60;

Example 2:

The preparation method of organic electroluminescent compound 2 is as follows:

The preparation method is basically the same as that in Example 1, except that compound 1-b in Example 1 is replaced by compound 2-b, yield 53.5%, ESI-MS (m/z) (M+): theoretical value 778.94, Found value 778.82, elemental analysis results (molecular formula C58H38N2O): theoretical value C, 89.43; H, 4.92; N, 3.60; O, 2.05; found value C, 89.43; H, 4.92; N, 3.60; O, 2.04.

Example 3:

The preparation method of organic electroluminescent compound 3 is as follows:

The preparation method is basically the same as that in Example 1, except that compound 1-d in Example 1 is replaced with compound 3-d, yield 46.9%, ESI-MS (m/z) (M+): theoretical value 855.03, Found value 856.24, elemental analysis results (molecular formula C64H42N2O): theoretical value C, 89.90; H, 4.95; N, 3.28; O, 1.87; found value C, C, 89.90; H, 4.95; N, 3.28; O, 1.87.

Example 4:

The preparation method of organic electroluminescent compound 6 is as follows:

The preparation method is basically the same as that in Example 1, except that the compounds 1-b and 1-d in Example 1 are replaced by compounds 4-b and 4-d, respectively, and the yield is 48.8%. ESI-MS (m/z )(M+): theoretical value 856.02, measured value 857.16, elemental analysis results (molecular formula C62H41N5): theoretical value C, 86.99; H, 4.83; N, 8.18; measured value C, C, 86.99; H, 4.82; N, 8.18 .

Example 5:

The preparation method of organic electroluminescent compound 13 is as follows:

The preparation method is basically the same as that of Example 1, except that compound 1-b in Example 1 is replaced with compound 5-b, yield 51.3%, ESI-MS (m/z) (M+): theoretical value 855.03, Measured value 856.19, elemental analysis result (molecular formula C64H42N2O): theoretical value C, C, 89.90; H, 4.95; N, 3.28; O, 1.87; measured value C, 89.91; H, 4.95; N, 3.28;

Example 6:

The preparation method of organic electroluminescent compound 17 is as follows:

The preparation method is basically the same as that of Example 1, except that compound 1-b in Example 1 is replaced with compound 6-b, yield 54.5%, ESI-MS (m/z) (M+): theoretical value 764.95, Found value 764.70, elemental analysis result (molecular formula C58H40N2): theoretical value C, 91.07; H, 5.27; N, 3.66; found value C, 91.08; H, 5.27; N, 3.66.

Example 7:

The preparation method of organic electroluminescent compound 19 is as follows:

The preparation method is basically the same as that in Example 1, except that compound 1-b in Example 1 is replaced with compound 7-b, yield 51.6%, ESI-MS (m/z) (M+): theoretical value 795.00, Measured value 796.43, elemental analysis results (molecular formula C58H38N2S): theoretical value C, 87.63; H, 4.82; N, 3.52; S, 4.03; found value C, 87.63; H, 4.83; N, 3.52;

Example 8:

The preparation method of organic electroluminescent compound 23 is as follows:

The preparation method is basically the same as that of Example 7, the difference is that compound 7-d in Example 7 is replaced by compound 8-d, yield 52.2%, ESI-MS (m/z) (M+): theoretical value 829.09, Measured value 830.48, elemental analysis results (molecular formula C60H36D6N2S): theoretical value C, 86.92; H, 5.83; N, 3.38; S, 3.87; measured value C, 86.93; H, 5.83; N, 3.38;

Example 9:

The preparation method of organic electroluminescent compound 25 is as follows:

The preparation method is basically the same as that of Example 1, except that compound 1-b in Example 1 is replaced by compound 9-b, yield 47.8%, ESI-MS (m/z) (M+): theoretical value 870.10, Found value 870.57, elemental analysis results (molecular formula C66H43D3N2): theoretical value C, 91.10; H, 5.68; N, 3.22; found value C, 91.11; H, 5.68; N, 3.22.

Example 10:

The preparation method of organic electroluminescent compound 33 is as follows:

The preparation method is basically the same as that of Example 1, except that compound 1-a in Example 1 is replaced with compound 10-a, yield 48.3%, ESI-MS (m/z) (M+): theoretical value 778.94, Measured value 778.72, elemental analysis results (molecular formula C58H38N2O): theoretical value C, 89.43; H, 4.92; N, 3.60; O, 2.05; found value C, 89.43; H, 4.92; N, 3.60;

Example 11:

The preparation method of organic electroluminescent compound 37 is as follows:

The preparation method is basically the same as that in Example 10, except that compound 10-d in Example 10 is replaced by compound 11-d, yield 46.0%, ESI-MS (m/z) (M+): theoretical value 879.05, Measured value 880.13, elemental analysis results (molecular formula C66H42N2O): theoretical value C, 90.18; H, 4.82; N, 3.19; O, 1.82; measured value C, 90.18; H, 4.82; N, 3.20;

Example 12:

The preparation method of organic electroluminescent compound 42 is as follows:

The preparation method is basically the same as that in Example 10, the difference is that compound 10-b in Example 10 is replaced by compound 12-b, yield 50.9%, ESI-MS (m/z) (M+): theoretical value 811.05, Found value 812.44, elemental analysis result (molecular formula C61H38D6N2): theoretical value C, 90.33; H, 6.21; N, 3.45; found value C, 90.34; H, 6.21; N, 3.44.

Example 13:

The preparation method of organic electroluminescent compound 49 is as follows:

The preparation method is basically the same as that of Example 10, except that compound 10-b in Example 10 is replaced by compound 13-b, yield 51.9%, ESI-MS (m/z) (M+): theoretical value 764.95, Found value 764.57, elemental analysis results (molecular formula C58H40N2): theoretical value C, 91.07; H, 5.27; N, 3.66; found value C, 91.07; H, 5.28; N, 3.66.

Example 14:

The preparation method of organic electroluminescent compound 51 is as follows:

The preparation method is basically the same as that of Example 10, except that compound 10-b in Example 10 is replaced by compound 14-b, yield 47.7%, ESI-MS (m/z) (M+): theoretical value 795.00, Measured value 796.38, elemental analysis results (molecular formula C58H38N2S): theoretical value C, 87.63; H, 4.82; N, 3.52; S, 4.03; found value C, 87.63; H, 4.83; N, 3.52;

Example 15:

The preparation method of organic electroluminescent compound 58 is as follows:

The preparation method is basically the same as that in Example 10, except that compound 10-b in Example 10 is replaced with compound 15-b, yield 43.1%, ESI-MS (m/z) (M+): theoretical value 1039.35, Measured value 1040.27, elemental analysis result (molecular formula C79H62N2): theoretical value C, 91.29; H, 6.01; N, 2.70; found value C, 91.29; H, 6.00; N, 2.70.

Example 16:

The preparation method of organic electroluminescent compound 69 is as follows:

The preparation method is basically the same as that in Example 11, the difference is that compound 11-a in Example 11 is replaced by compound 16-a, the yield is 45.7%, ESI-MS (m/z) (M+): theoretical value 929.11, Measured value 930.06, elemental analysis results (molecular formula C70H44N2O): theoretical value C, 90.49; H, 4.77; N, 3.02; O, 1.72; measured value C, 90.49; H, 4.77; N, 3.02;

Example 17:

The preparation method of organic electroluminescent compound 81 is as follows:

The preparation method is basically the same as that in Example 16, except that the compounds 16-b and 16-d in Example 16 are replaced by compounds 17-b and 17-d, respectively, the yield is 52.1%, ESI-MS (m/z )(M+): theoretical value 815.01, measured value 816.40, elemental analysis results (molecular formula C62H42N2): theoretical value C, 91.37; H, 5.19; N, 3.44; measured value C, 91.38; H, 5.19; N, 3.44.

Example 18:

The preparation method of organic electroluminescent compound 87 is as follows:

The preparation method is basically the same as that in Example 16, except that the compounds 16-b and 16-d in Example 16 are replaced by compounds 18-b and 18-d, respectively, the yield is 50.3%, ESI-MS (m/z )(M+): theoretical value 879.15, measured value 880.23, elemental analysis results (molecular formula C64H38D6N2S): theoretical value C, 87.44; H, 5.73; N, 3.19; S, 3.65; measured value C, 87.45; H, 5.73; N , 3.20; S, 3.65.

Example 19:

The preparation method of organic electroluminescent compound 99 is as follows:

The preparation method is basically the same as that in Example 3, except that compound 3-a in Example 3 is replaced by compound 19-a, yield 45.4%, ESI-MS (m/z) (M+): theoretical value 905.09, Found value 906.61, elemental analysis results (molecular formula C68H44N2O): theoretical value C, 90.24; H, 4.90; N, 3.10; O, 1.77; found value C, 90.24; H, 4.90; N, 3.10; O, 1.78.

Example 20:

The preparation method of organic electroluminescent compound 130 is as follows:

The preparation method is basically the same as that of Example 2, except that compound 2-b in Example 2 is replaced with compound 20-b, yield 53.0%, ESI-MS (m/z) (M+): theoretical value 778.94, Found 778.80, elemental analysis results (molecular formula C58H38N2O): theoretical value C, 89.43; H, 4.92; N, 3.60; O, 2.05; found value C, 89.42; H, 4.92; N, 3.60; O, 2.05.

Example 21:

The preparation method of organic electroluminescent compound 143 is as follows:

The preparation method is basically the same as that of Example 20, except that compound 20-d in Example 20 is replaced by compound 21-d, yield 51.7%, ESI-MS (m/z) (M+): theoretical value 828.99, Measured value 828.29, elemental analysis results (molecular formula C62H40N2O): theoretical value C, 89.83; H, 4.86; N, 3.38; O, 1.93; measured value C, 89.83; H, 4.86; N, 3.38;

The sources of compounds 1-a to 21-a in Examples 1-21 of the present invention are as follows:

The sources of compounds 1-b to 21-b in Examples 1-21 of the present invention are as follows:

The sources of compounds 1-d to 21-d in Examples 1-21 of the present invention are as follows:

Material property testing:

Test the organic electroluminescent compounds 1, 2, 3, 6, 13, 17, 19, 23, 25, 33, 37, 42, 49, 51, 58, 69, 81, 87 in the examples 1-21 of the present invention , 99, 130, 143 glass transition temperature Tg and thermal weight loss temperature Td, the results are shown in Table 1:

Note: The thermal weight loss temperature Td is the temperature at which the weight loses 5% in a nitrogen atmosphere. It is measured on a TGA N-1000 thermogravimetric analyzer. The nitrogen flow rate is 10 mL/min during the measurement. The glass transition temperature Tg is determined by differential scanning calorimetry ( DSC, DSC204F1 differential scanning calorimeter of NETZSCH, Germany) was measured, and the heating rate was 10°C/min.

Table 1:

It can be seen from the above table 1 that the organic electroluminescent compound of the present invention has higher Tg value and Td value, indicating that it has excellent thermal stability, and can be effectively extended when used as an organic electroluminescent material in organic electroluminescent devices. The service life of the organic electroluminescent device can achieve better use effect.

Device performance test:

Application example 1:

ITO was used as the anode substrate material of the reflective layer, and the surface was treated with water, acetone, and _N2 plasma in turn;

On top of the ITO anode substrate, a HAT-CN with a thickness of 10 nm was deposited to form a hole injection layer (HIL);

Evaporating NPD over the hole injection layer (HIL) to form a hole transport layer (HTL) with a thickness of 100 nm;

The organic electroluminescent compound 1 prepared in Example 1 of the present invention is vacuumed above the hole transport layer (HTL) to form an electron blocking layer (EBL) with a thickness of 8 nm;

ADN was used as the blue light host material and BD-1 was used as the blue light doping material (the amount of BD-1 was 5% of the weight of ADN) and evaporated at different rates on the hole transport layer (HTL) to form a light-emitting layer with a thickness of 20 nm;

Evaporating HB-1 onto the light-emitting layer to obtain a hole blocking layer (HBL) with a thickness of 20 nm;

ET-1 was evaporated onto the hole blocking layer (HBL) as an electron transport layer material (ET) to obtain an electron transport layer (ETL) with a thickness of 30 nm, and LiQ with a thickness of 2 nm was evaporated on the electron transport layer (ETL). forming an electron injection layer (EIL);

Thereafter, magnesium (Mg) and silver (Ag) were mixed and evaporated in a ratio of 9:1 to obtain a cathode with a thickness of 15 nm, and DNTPD with a thickness of 50 nm was deposited on the cathode sealing layer. A seal cap containing a dehumidifying agent is sealed to protect the organic electroluminescent device from being affected by oxygen or moisture in the atmosphere. The organic electroluminescent device is thus prepared.

Application example 2-21

The organic electroluminescent compounds 2, 3, 6, 13, 17, 19, 23, 25, 33, 37, 42, 49, 51, 58, 69, 81, 87, 99, 130, and 143 are used as electron blocking layer materials, and other parts are the same as those of Application Example 1, and the organic electroluminescent devices of Application Examples 2-21 are fabricated accordingly.

Control example

The difference between the control example and the application example 1 is that EB-1 is used as the material of the electron blocking layer, and the rest are the same as the application example 1.

The organic electroluminescent devices prepared in Application Examples 1-21 and Comparative Example were tested respectively, and the test results are shown in Table 1.

Table 2:

As can be seen from Table 2 above, when the organic electroluminescent compound of the present invention is applied to an organic electroluminescent device as an electron blocking layer material, the luminous efficiency of the device is greatly improved, the startup voltage is decreased, and the power consumption is relatively reduced.

The organic electroluminescent devices prepared in the control examples and application examples 1, 2, 5, 6, 7, 10, and 14 were tested for luminescence lifetime, and the luminescence lifetime T97% data (the time when the luminous brightness was reduced to 97% of the initial brightness) were obtained. , the test equipment is a TEO light-emitting device life test system. The results are shown in Table 3:

table 3:

test group Current density (mA/cm²) T97%/h Control example 10 312 Application example 1 10 344 Application example 2 10 350 Application example 5 10 348 Application example 6 10 353 Application example 7 10 359 Application example 10 10 340 Application example 14 10 342

It can be seen from the above Table 3 that when the organic electroluminescent compound of the present invention is applied to an organic electroluminescent device as an electron blocking layer material, the service life of the device is greatly improved, so it has a very broad application prospect.

Claims (12)

1. An organic electroluminescent compound based on a triphenylamine structure is characterized in that the structural formula is as follows:

ar1 and Ar2 are the same or different and are respectively and independently C6-C30 aryl, C5-C30 heteroaryl, and at least one hydrogen in the C6-C30 aryl and the C5-C30 heteroaryl can be substituted or unsubstituted by C1-C4 alkyl, C1-C4 deuterated alkyl, phenyl and cyano;

l is a C6-C30 arylene group, and L is not phenylene;

m and n are each independently 1 or 2.

2. The organic electroluminescent compound according to claim 1, wherein Ar1 and Ar2 are the same or different and each independently is phenyl, biphenyl, pyridyl, pyrimidyl, triazinyl, anthracyl, naphthyl, phenanthryl, oxyfluorenyl, thiofluorenyl, carbazolyl, N-phenylcarbazolyl, fluorenyl, 9-dimethylfluorenyl, 9-diphenylfluorenyl, 9-methyl-9-phenylfluorenyl, 9' -spirobifluorenyl;

the phenyl, biphenyl, pyridyl, pyrimidyl, triazinyl, anthryl, naphthyl, phenanthryl, oxyfluorenyl, thiofluorenyl, carbazolyl, N-phenylcarbazolyl, fluorenyl, 9-dimethylfluorenyl, 9-diphenylfluorenyl, 9-methyl-9-phenylfluorenyl, 9' -spirobifluorenyl are unsubstituted or at least one hydrogen thereof is substituted by deuterium, alkyl of C1-C4, deuterated alkyl of C1-C4, phenyl or cyano.

3. The organic electroluminescent compound according to claim 2, wherein when Ar1 and Ar2 are both phenyl groups, m and n are not both 1.

4. The organic electroluminescent compound according to claim 1, wherein L is a naphthylene group or an anthracenylene group.

5. The organic electroluminescent compound according to claim 4, wherein the structural formula is any one of the following:

6. the organic electroluminescent compound according to claim 4, wherein the structural formula is any one of the following:

7. the organic electroluminescent compound according to any one of claims 1 to 6, wherein the organic electroluminescent compound is any one of the following compounds:

8. use of an organic electroluminescent compound as claimed in any one of claims 1 to 5 for the preparation of an organic electroluminescent device.

9. An organic electroluminescent device, comprising an anode and a cathode which are oppositely arranged, and a functional layer which is arranged between the anode and the cathode; the functional layer contains the organic electroluminescent compound as claimed in any one of claims 1 to 5.

10. The organic electroluminescent device of claim 7, wherein the functional layer comprises: a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, at least one of which contains the organic electroluminescent compound according to any one of claims 1 to 5.

11. The organic electroluminescent device according to claim 8, wherein at least one of the hole transport layer, the electron blocking layer, and the light emitting layer contains the organic electroluminescent compound according to any one of claims 1 to 6.

12. An OLED display device comprising the organic electroluminescent element as claimed in claim 7.

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