6, 6-dimethyl-6H-benzo [cd] pyrene compound and intermediate thereof, organic electroluminescent device and display device

Abstract

The invention provides a 6, 6-dimethyl-6H-benzo [cd] pyrene compound, an intermediate thereof, an organic electroluminescent device and a display device, and relates to the technical field of organic photoelectricity. The structural general formula of the 6, 6-dimethyl-6H-benzo [cd] pyrene compound is # imgabs0 #, and m and n are respectively and independently selected from 0 or 1; hydrogen atoms in the formula I are respectively and independently substituted or not substituted by deuterium atoms, F, CN, C1-C12 alkyl, C6-C30 aryl or C3-C30 aromatic heterocyclic groups. According to the present invention, the structure of the 6, 6-dimethyl-6H-benzo [cd] pyrene compound is designed, such that the obtained 6, 6-dimethyl-6H-benzo [cd] pyrene compound has excellent performance, and the organic light-emitting device prepared by using the 6, 6-dimethyl-6H-benzo [cd] pyrene compound as the light-emitting layer material has characteristics of low driving voltage, high current efficiency and long service life.

Description

Technical Field

[0001] The invention belongs to the field of organic photoelectric technology, and specifically relates to a 6,6-dimethyl-6H-benzo[cd]pyrene compound and an intermediate thereof, an organic electroluminescent device and a display device. Background Art

[0002] Organic light emitting diodes (OLEDs) are display components that utilize the phenomenon of self-luminescence and have a wide viewing angle. Compared with liquid crystal display components, OLED components are thinner and lighter, have a faster response speed, and can achieve flexible displays. Therefore, their application as full-color display components or lighting equipment is highly anticipated.

[0003] Generally, organic light emitting phenomenon refers to the phenomenon of converting electrical energy into light energy using organic substances. An organic light emitting element using the organic light emitting phenomenon generally has a structure including an anode, a cathode, and an organic material layer interposed between the anode and the cathode.

[0004] Among them, the organic layer is composed of a multilayer structure composed of different substances in most cases in order to improve the efficiency and stability of the organic light-emitting element. For example, it can be composed of a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, etc. If a voltage is applied between the two electrodes in the structure of such an organic light-emitting element, the holes in the anode will be injected into the organic layer, and the electrons in the cathode will also be injected into the organic layer. When the injected holes and electrons meet, excitons are formed. When the excitons release energy and transition to the ground state, photons will be emitted, thereby generating light. Such organic light-emitting elements are widely recognized to have the characteristics of self-luminescence, high brightness, high efficiency, low driving voltage, wide viewing angle, high contrast, and high-speed responsiveness.

[0005] At present, the research on organic electroluminescent materials has been widely carried out in academia and industry. Among them, luminescent materials are an important component of organic electroluminescent devices. The transmission performance and luminous efficiency of luminescent materials restrict the industrialization of luminescent devices. Therefore, designing and finding a compound as a new OLED material to overcome its shortcomings in practical applications is the focus of OLED material research and the future research and development trend. Summary of the invention

[0006] In view of the shortcomings of the prior art, the object of the present invention is to provide a 6,6-dimethyl-6H-benzo[cd]pyrene compound and its intermediate, an organic electroluminescent device and a display device. The present invention is designed based on the structure of the 6,6-dimethyl-6H-benzo[cd]pyrene compound, and the obtained 6,6-dimethyl-6H-benzo[cd]pyrene compound has excellent performance and is suitable for use as a light-emitting layer material in an organic electroluminescent device.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a 6,6-dimethyl-6H-benzo[cd]pyrene compound, wherein the 6,6-dimethyl-6H-benzo[cd]pyrene compound has a structure as shown in the following formula I:

[0009]

[0010] Wherein m and n are each independently selected from 0 or 1;

[0011] The hydrogen atoms in the compound are each independently replaced by a deuterium atom, F, CN, C1-C 12 Alkyl, C6-C 30 Aryl, C3~C 30 The aromatic heterocyclic group may be substituted or unsubstituted.

[0012] The C6-C 30 Aryl refers to a general term for a monovalent group remaining after removing a hydrogen atom from the aromatic carbon nucleus of an aromatic hydrocarbon molecule, which may be a monocyclic aromatic group or a condensed aromatic group, and illustratively includes but is not limited to: one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenyl, fluorenyl, perylenyl, phenanthrenyl, pyrenyl, fluoranthenyl, and triphenylenyl;

[0013] The C3-C 30 The aromatic heterocyclic group is selected from dibenzofuranyl, dibenzothienyl, carbazolyl, naphthobenzofuranyl, naphthobenzothienyl and benzocarbazolyl.

[0014] The C1-C 12 The alkyl group is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl and cyclohexyl;

[0015] As a preferred technical solution of the present invention, in Formula I, m and n are both selected from 0.

[0016] As a preferred technical solution of the present invention, in Formula I, m and n are both selected from 1.

[0017] As a preferred technical solution of the present invention, in Formula I, m+n=1.

[0018] As a preferred technical solution of the present invention, the hydrogen atoms in the compound of formula I can be independently replaced by one or a combination of two of phenyl, carbazolyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl, and dibenzofuranyl.

[0019] As a preferred technical solution of the present invention, the 6,6-dimethyl-6H-benzo[cd]pyrene compound includes any one of the following compounds:

[0020]

[0021]

[0022]

[0023]

[0024]

[0025] Preferably, the 6,6-dimethyl-6H-benzo[cd]pyrene compound includes any one of the following compounds:

[0026]

[0027] The present invention lists some specific structural forms of the 6,6-dimethyl-6H-benzo[cd]pyrene compounds, but the 6,6-dimethyl-6H-benzo[cd]pyrene compounds of the present invention are not limited to these listed chemical structures, and all structures based on the structure shown in Formula I that meet the above-mentioned limiting conditions should be included.

[0028] The preparation method of 6,6-dimethyl-6H-benzo[cd]pyrene compounds of the present application is illustrated as follows:

[0029]

[0030] Wherein X1 and X2 are each independently selected from F, Cl, Br or I;

[0031] m and n are each independently selected from 0 or 1.

[0032] The present invention also provides an intermediate of a 6,6-dimethyl-6H-benzo[cd]pyrene compound having a structure shown in Formula MA:

[0033]

[0034] wherein X1 is selected from F, Cl, Br or I;

[0035] m and n are each independently selected from 0 or 1.

[0036] MA is used to synthesize the 6,6-dimethyl-6H-benzo[cd]pyrene compounds of the present invention.

[0037] Preferably, the intermediate is selected from the following structures:

[0038]

[0039] In a second aspect, the present invention provides an organic electroluminescent device, wherein the organic electroluminescent device comprises the 6,6-dimethyl-6H-benzo[cd]pyrene compound as described in the first aspect.

[0040] Preferably, the organic electroluminescent device comprises a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode;

[0041] The material of the organic layer includes the 6,6-dimethyl-6H-benzo[cd]pyrene compound as described in the first aspect.

[0042] Preferably, the organic layer comprises a light-emitting layer;

[0043] The main material of the light-emitting layer includes the 6,6-dimethyl-6H-benzo[cd]pyrene compound as described in the first aspect.

[0044] In a third aspect, the present invention provides a display device, comprising the organic electroluminescent device as described in the second aspect.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention designs the structure of 6,6-dimethyl-6H-benzo[cd]pyrene compounds. A carbazole group is connected to the benzene ring of the phenyl-substituted 6,6-dimethyl-6H-benzo[cd]pyrene compounds. The carbazole group has a higher triplet energy level. The 6,6-dimethyl-6H-benzo[cd]pyrene has a large conjugated plane structure and good charge transfer performance. The two methyl groups on the 6,6-dimethyl-6H-benzo[cd]pyrene improve the film-forming property of the molecule. The above structural design enables the compound of the present invention to have good luminescent performance and can be used for preparing organic electroluminescent devices, especially as a main material of a luminescent layer in the organic electroluminescent device, and can effectively reduce the driving voltage of the organic electroluminescent device and improve the current efficiency of the organic electroluminescent device. DETAILED DESCRIPTION

[0047] For the convenience of understanding the present invention, the present invention lists the preparation examples and embodiments as follows. It should be understood by those skilled in the art that the preparation examples and embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0048] Preparation Example 1

[0049] This preparation example provides a method for synthesizing intermediate A, as described below:

[0050]

[0051] (1) Synthesis of intermediate A-2

[0052] In a three-necked flask, under a nitrogen atmosphere, add 3.4 g of intermediate A-1 and 60 ml of tetrahydrofuran, then cool to -75°C, slowly add 0.01 mol of butyl lithium in n-hexane solution (concentration 1.6M, 6.3 ml), then maintain at -78°C--60°C for 30 min, slowly add 1.5 g of trimethyl borate, slowly warm to room temperature and stir for 2 hours, add dilute hydrochloric acid and ethyl acetate, separate the liquids, wash the organic layer with a saturated sodium chloride solution, and concentrate to dryness. The obtained viscous solid is intermediate A-2, which is directly subjected to the following reaction without separation.

[0053] (2) Synthesis of intermediate A

[0054] Under nitrogen protection, 60 mL of toluene, 30 mL of ethanol, and 20 mL of water were added to the three-necked flask in sequence, and then the intermediate A-2 prepared in the previous step and 3.6 g of 2.12g (0.02mol) of sodium carbonate and 0.23g (0.0002mol) of tetrakistriphenylphosphine palladium were slowly heated to reflux for reaction for 8h, cooled to room temperature, separated by adding water, the organic layer was washed with water, dried with magnesium sulfate, the desiccant was removed, concentrated to dryness, and separated by silica gel column chromatography, eluted with petroleum ether: dichloromethane = 10:2 (volume ratio), and 2.1g of intermediate A was obtained;

[0055] The obtained intermediate A was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 574.13.

[0056] Preparation Example 2

[0057] This preparation example provides a method for synthesizing intermediate B, as described below:

[0058]

[0059] Referring to the preparation method of intermediate A, intermediate B was prepared.

[0060] The obtained intermediate B was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 574.13.

[0061] Preparation Example 3

[0062] This preparation example provides a method for synthesizing intermediate C, as described below:

[0063]

[0064] Referring to the preparation method of intermediate A, intermediate C was prepared.

[0065] The obtained intermediate C was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 422.07.

[0066] Preparation Example 4

[0067] This preparation example provides a method for synthesizing intermediate D, as described below:

[0068]

[0069] Referring to the preparation method of intermediate A, intermediate D was prepared.

[0070] The obtained intermediate D was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 422.07.

[0071] Preparation Example 5

[0072] This preparation example provides a method for synthesizing intermediate E, as described below:

[0073]

[0074] Referring to the preparation method of intermediate A, intermediate E was prepared.

[0075] The obtained intermediate E was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 422.07.

[0076] Preparation Example 6

[0077] This preparation example provides a method for synthesizing intermediate F, as described below:

[0078]

[0079] Referring to the preparation method of intermediate A, intermediate F was prepared.

[0080] The obtained intermediate F was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 498.10.

[0081] Synthesis Example 1

[0082] This embodiment provides a method for synthesizing compound 1, as described below:

[0083]

[0084] Under nitrogen protection, dry toluene (100 mL), intermediate A (5.7 g), carbazole (1.7 g), Pd(dba)2 (bis(dibenzylideneacetonepalladium, 0.0575 g, 0.0001 mol), 10% tri-tert-butylphosphine toluene solution (the mass of tri-tert-butylphosphine solution is 0.4 g, and the amount of tri-tert-butylphosphine is 0.0002 mol) and sodium tert-butoxide (1.44 g, 0.015 mol) were added to a three-necked flask, heated to reflux, reacted for 12 hours, cooled to room temperature, water was added to separate, and the organic layer was washed with water until neutral, dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, and crystallized from toluene to obtain compound 1 (4.7 g).

[0085] Mass spectrometry was performed on compound 1: the mass-to-charge ratio (m / z) was measured to be 661.28.

[0086] Synthesis Example 2-8

[0087] Referring to the synthesis method of compound 1, the following compounds were prepared using different raw materials, and the mass spectra were measured and the mass-to-charge ratios (m / z) were recorded as shown in Table 1.

[0088] Table 1

[0089]

[0090]

[0091]

[0092] Other compounds whose specific synthesis steps are not listed can be prepared by common knowledge in the art in combination with the above embodiments.

[0093] In the present invention, the specific structure of the materials used in the following application examples is as follows:

[0094]

[0095] Synthesis of H-1

[0096]

[0097] Referring to the synthesis method of compound 1, compound H-1 was synthesized.

[0098] The mass spectrometry of compound H-1 was performed: the mass-to-charge ratio (m / z) was measured to be 598.24.

[0099] Synthesis of H-2

[0100]

[0101] Referring to the synthesis method of compound 1, compound H-2 was synthesized.

[0102] The mass spectrometry of compound H-2 was performed: the mass-to-charge ratio (m / z) was measured to be 433.18.

[0103] Device Example 1

[0104] The device embodiment provides an organic electroluminescent device, using the compound 1 provided in Synthesis Example 1 of the present invention as the main material of the light-emitting layer; the structure of the organic electroluminescent device is:

[0105] ITO / HT (40nm) / light-emitting layer main material: PGD-16% (30nm) / TPBI (30nm) / LiF (0.5nm) / Al (150nm).

[0106] The preparation method of the organic electroluminescent device is as follows:

[0107] The glass substrate coated with an ITO transparent conductive layer (as an anode) was ultrasonically treated in a cleaning agent, then rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone and ethanol, and then baked in a clean environment until the water was completely removed. It was cleaned with ultraviolet light and ozone, and the surface was bombarded with a low-energy cation beam to improve the surface properties and enhance the bonding ability with the hole layer.

[0108] The material was placed in a vacuum chamber and evacuated to 1×10 -5 -1×10 -6 Pa, and then vacuum evaporated onto the cleaned ITO substrate. Among them, the main material of the light-emitting layer: PGD-16% (30nm) means that in the device, the main material of the light-emitting layer and PGD-1 are co-evaporated in a volume ratio of 94:6 to form a light-emitting layer, and the thickness of the light-emitting layer is 30nm.

[0109] Device Examples 2-8

[0110] Device Examples 2-8 respectively provide an organic electroluminescent device, which differs from Device Example 1 only in that the main material of the light-emitting layer is different (see Table 2 below for details), and other conditions are the same as those of Device Example 1.

[0111] Device Comparison Examples 1-3

[0112] Device Comparative Examples 1-3 respectively provide an organic electroluminescent device, which is different from Device Example 1 only in that the main body of the light-emitting layer is different (see Table 2 below for details), and other conditions are the same as those of Device Example 1.

[0113] Performance Testing

[0114] Test the driving voltage, current efficiency and life LT90 of the OLED devices provided above; LT90 refers to the time required for the brightness to drop to 90% of the original brightness while maintaining the current density at the initial brightness of 1000nit. The test items include the brightness, driving voltage and current efficiency of the organic electroluminescent device. The driving voltage, current efficiency and LT90 data are all based on a brightness of 1000cd / m 2 The relative value of the organic electroluminescent device performance test results are shown in Table 2 below:

[0115] Table 2

[0116]

[0117]

[0118] It can be seen from the contents of Table 2 that the present invention obtains 6,6-dimethyl-6H-benzo[cd]pyrene compounds through molecular design. The 6,6-dimethyl-6H-benzo[cd]pyrene compounds provided by the present invention can be used as the main material of the light-emitting layer of an OLED light-emitting device, so that the OLED light-emitting device has a lower driving voltage, a higher current efficiency and a longer life.

[0119] The present invention illustrates the detailed process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A 6,6-dimethyl-6H-benzo[cd]pyrene compound, characterized in that: The 6,6-dimethyl-6H-benzo[cd]pyrene compound has a structure shown in Formula I: Wherein, m and n are each independently selected from 0 or 1; The hydrogen atoms in Formula I are each independently replaced by a deuterium atom, F, CN, C1-C 12 Alkyl, C6-C 30 Aryl or C3-C 30 The aromatic heterocyclic group may be substituted or unsubstituted.

2. The 6,6-dimethyl-6H-benzo[cd]pyrene compound according to claim 1, characterized in that: The C6-C 30 The aryl group is selected from one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenyl, fluorenyl, perylenyl, phenanthrenyl, pyrenyl, fluoranthenyl and triphenylenyl; The C3-C 30 The aromatic heterocyclic group is selected from one of dibenzofuranyl, dibenzothiophenyl, carbazolyl, naphthobenzofuranyl, naphthobenzothiophenyl and benzocarbazolyl; C1-C 12 The alkyl group is selected from one of methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl and cyclohexyl.

3. The 6,6-dimethyl-6H-benzo[cd]pyrene compound according to claim 1, characterized in that: Wherein m and n are both 0; preferably, m and n are both 1; preferably, m+n=1.

4. The 6,6-dimethyl-6H-benzo[cd]pyrene compound according to claim 1, characterized in that: The hydrogen atoms in the 6,6-dimethyl-6H-benzo[cd]pyrene compound are independently substituted by one or a combination of two of phenyl, carbazolyl, naphthyl, biphenyl, 9,9-dimethylfluorenyl and dibenzofuranyl.

5. The 6,6-dimethyl-6H-benzo[cd]pyrene compound according to claim 1, characterized in that: The 6,6-dimethyl-6H-benzo[cd]pyrene compound includes any one of the following compounds: Preferably, the 6,6-dimethyl-6H-benzo[cd]pyrene compound includes any one of the following compounds:

6. An intermediate of 6,6-dimethyl-6H-benzo[cd]pyrene compounds according to any one of claims 1 to 5, characterized in that: It has the structure shown in formula MA: wherein X1 is selected from F, Cl, Br or I; m and n are each independently selected from 0 or 1.

7. The intermediate of 6,6-dimethyl-6H-benzo[cd]pyrene compounds according to claim 6, characterized in that: The intermediate is selected from the following structures:

8. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the 6,6-dimethyl-6H-benzo[cd]pyrene compound according to any one of claims 1-5.

9. The organic electroluminescent device according to claim 8, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode; The material of the organic layer includes the 6,6-dimethyl-6H-benzo[cd]pyrene compound; Preferably, the organic layer comprises a light-emitting layer; The main material of the light-emitting layer includes the 6,6-dimethyl-6H-benzo[cd]pyrene compound.

10. A display device, characterized in that: An organic electroluminescent device comprising the organic electroluminescent device according to claim 8 or 9.

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