Deuterated benzofuran compounds, organic electroluminescent devices and display devices

Abstract

The present invention provides a compound represented by formula (I), an organic electroluminescent device and a display device. The compound provided by the present invention can be used as a main material of a 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 high-temperature life.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescent materials, and in particular relates to a deuterated benzofuran compound, an organic electroluminescent device and a display device. Background Art

[0002] An organic electroluminescent device is a device made by depositing one or more layers of organic materials between two metal electrodes by spin coating or vacuum evaporation. A classic three-layer organic electroluminescent device includes a hole transport layer, a light-emitting layer, and an electron transport layer. The holes generated by the anode pass through the hole transport layer and the electrons generated by the cathode pass through the electron transport layer to combine in the light-emitting layer to form excitons, and then emit light. Organic electroluminescent devices can be adjusted to emit various required lights by changing the material of the light-emitting layer as needed.

[0003] As a new type of display technology, organic electroluminescent devices have unique advantages such as self-luminescence, wide viewing angle, low energy consumption, high efficiency, thinness, rich colors, fast response speed, wide applicable temperature range, low driving voltage, the ability to produce flexible, bendable and transparent display panels, and environmental friendliness. They can be used in flat-panel displays and new generation lighting, and can also be used as LCD backlight sources.

[0004] Since its invention in the late 1980s, organic electroluminescent devices have been used in industry, such as screens for cameras and mobile phones. However, the current OLED devices are limited in their wider application due to low efficiency and short service life, especially for large-screen displays. Therefore, the efficiency of the devices needs to be improved. One of the important factors is the performance of the organic electroluminescent materials in the organic electroluminescent devices. Therefore, it is necessary to develop stable and efficient organic electroluminescent materials to improve the current efficiency and service life of OLED devices.

[0005] In addition, in some application scenarios, such as in-vehicle displays, the operating temperature of the display is relatively high, sometimes reaching 60°C or even 80°C. Therefore, the performance of the device at high temperatures, such as life data, is also critical. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a deuterated benzofuran compound, an organic electroluminescent device and a display device. The compound provided by the present invention can be used as a 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 high-temperature life.

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

[0008] In a first aspect, the present invention provides a compound as shown in the following formula (I):

[0009]

[0010] Wherein D7 means that seven carbon atoms of the corresponding dibenzofuran are connected to D atoms, and another carbon atom is connected to the anthracene ring; Dn means that n carbon atoms of the corresponding anthracene ring are connected to D atoms;

[0011] n is selected from 0 or 8;

[0012] The following compounds are not included:

[0013]

[0014] In a second aspect, the present invention provides an organic electroluminescent device, comprising an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode, wherein the organic thin film layer comprises the compound as described in the first aspect.

[0015] Preferably, the organic thin film layer includes a light-emitting layer, and the material of the light-emitting layer includes the compound as described in the first aspect.

[0016] Preferably, the material of the light-emitting layer further includes a doping material (dye, light-emitting layer guest material).

[0017] As a preferred technical solution of the present invention, the compound of formula (I) is selected from any one of the following compounds:

[0018]

[0019]

[0020] In the present invention, the compound is used as the main material of the light-emitting layer, and the light-emitting layer material further comprises a compound having a structure as shown in Formula II and / or a compound having a structure as shown in Formula III and / or a compound having a structure as shown in Formula BDI as a doping material:

[0021]

[0022] Among them, Ar 21 ,Ar 22 Each is independently selected from any one of a substituted or unsubstituted C6-C20 (for example, C6, C8, C10, C12, C16 or C20, etc.) aryl group, and a substituted or unsubstituted C3-C20 (for example, C3, C6, C8, C10, C12, C16 or C20, etc.) heteroaryl group;

[0023] R 21 , R 22 and R 23Each is independently selected from any one of hydrogen, C1-C12 (for example, C1, C2, C4, C6, C8, C10 or C12, etc.) straight chain or branched chain alkyl, C6-C12 (for example, C6, C8, C10 or C12, etc.) cycloalkyl;

[0024] Ar 21 ,Ar 22 The substituents in the substitution are each independently selected from C1-C5 (e.g., methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, etc.) straight chain or branched chain alkyl or C6-C12 (e.g., phenyl, biphenyl, naphthyl, etc.) aryl;

[0025] Ar 31 ,Ar 32 ,Ar 33 and Ar 34 Each is independently selected from any one of a substituted or unsubstituted C6-C22 (for example, C6, C8, C10, C16, C18 or C22, etc.) aryl group, and a substituted or unsubstituted C12-C40 (for example, C12, C18, C20, C24, C30, C36 or C40, etc.) heteroaryl group;

[0026] R 31 Any one selected from phenyl, naphthyl or biphenyl;

[0027] a is selected from 0 or 1;

[0028] Ar 31 ,Ar 32 ,Ar 33 ,Ar 34 The substituents are each independently selected from C1-C5 straight or branched alkyl (e.g., methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, etc.) or C6-C12 (e.g., C6, C8, C10 or C12, etc.) aryl;

[0029] Ar 101 ,Ar 102 ,Ar 201 ,Ar 202 Each is independently selected from any one of a substituted or unsubstituted C6-C40 aryl group and a substituted or unsubstituted C12-C20 heteroaryl group;

[0030] m is selected from 0 or 1;

[0031] Ar 101 ,Ar 102 ,Ar 201 ,Ar 202The substituted substituent is selected from any one of -D, -F, -CN, C1-C12 alkyl, C1-C6 alkoxy, C6-C20 aryl, and C12-C20 heteroaryl, or a combination of at least two thereof.

[0032] As a preferred technical solution of the present invention, the Ar 21 ,Ar 22 Each independently selected from

[0033] Any one of .

[0034] Preferably, the R 21 , R 22 and R 23 Each is independently selected from any one of hydrogen, methyl, ethyl, propyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclohexyl or adamantyl.

[0035] Preferably, Ar 31 ,Ar 32 ,Ar 33 and Ar 34 Each independently selected from Any one or a combination of at least two of the following.

[0036] As a preferred technical solution of the present invention, the compound having a structure as shown in Formula II is selected from any one of the following compounds:

[0037]

[0038]

[0039] As a preferred technical solution of the present invention, the compound having a structure as shown in Formula III is selected from any one of the following compounds:

[0040]

[0041] As a preferred technical solution of the present invention, in the formula BDI, the C6-C40 aromatic group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthanofluorenyl, pyrene, peryl, spirofluorenyl, triphenylene, fluoranthenyl, hydrogenated benzanthryl, indenofluorenyl, benzoindenofluorenyl, dibenzoindenofluorenyl, naphthanofluorenyl or benzonaphthofluorenyl.

[0042] Preferably, in the formula BDI, the C12-C20 heteroaryl group is selected from any one of dibenzofuranyl, dibenzothiophenyl, naphthobenzofuranyl, naphthobenzothiophenyl, dinaphthofuranyl and dinaphthothiophenyl.

[0043] As a preferred technical solution of the present invention, in the formula BDI, the C1-C12 alkyl group is selected from any one of methyl, ethyl, propyl, butyl, cyclopentyl, cyclohexyl, methylcyclohexyl, methylcyclopentyl or adamantyl.

[0044] Preferably, in formula BDI, the C1-C6 alkoxy group is selected from any one of methoxy, ethoxy, propoxy or butoxy.

[0045] Preferably, in the formula BDI, the C6-C20 aryl group is selected from any one of a phenyl group, a biphenyl group, a 9,9-dimethylfluorenyl group, a naphthyl group, a fluoranthenyl group or a triphenylene group.

[0046] As a preferred technical solution of the present invention, in the formula BDI, the Ar 101 and Ar 101 Each independently selected from any one of the following substituted or unsubstituted groups: phenyl, naphthyl, biphenyl, dibenzofuranyl, 9,9-dimethylfluorenyl, terphenyl, Fluoranthene, naphthobenzofuranyl, benzofluorenyl;

[0047] In the formula BDI, the substituted substituent is selected from phenyl, methyl, adamantyl, tert-butyl, 1-hexylcyclopentyl, cyclopentyl, cyclohexyl, At least one of naphthyl, dibenzothienyl, dibenzofuranyl, naphthiobenzothienyl, naphthiobenzofuranyl, -F, -CN, -D, and methoxy;

[0048] The dotted lines indicate the connection sites.

[0049] Preferably, in the formula BDI, the Ar 101 and Ar 101 Each is independently selected from any one of the following groups:

[0050] The dotted lines indicate the connection sites.

[0051] As a preferred technical solution of the present invention, the Ar 201 and Ar 202 Each is independently selected from any one of the following substituted or unsubstituted groups: phenyl, naphthyl, dibenzofuranyl or biphenyl;

[0052] In the formula BDI, the substituted substituent is selected from any one or a combination of at least two of methyl, methoxy, phenyl or dibenzofuranyl.

[0053] In the formula BDI, preferably, the Ar 201 and Ar 202 each independently phenyl, or dibenzofuranyl.

[0054] The dotted lines indicate the connection sites.

[0055] As a preferred technical solution of the present invention, the BDI compound is selected from any one of the following substituted or unsubstituted compounds:

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068] The substitution means that at least one hydrogen atom in the above compound is replaced by a deuterium atom.

[0069] It should be noted that the substitution means that at least one hydrogen atom in the above compound is replaced by a deuterium atom. The hydrogen atoms on the ion are not replaced by deuterium atoms.

[0070] In a fourth aspect, the present invention provides a display device, comprising the organic electroluminescent device as described in the third aspect.

[0071] Compared with the prior art, the present invention has the following beneficial effects:

[0072] The compound of the invention enables the OLED light-emitting device to have higher current efficiency and longer high-temperature life. DETAILED DESCRIPTION

[0073] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0074] Preparation of intermediates

[0075] Synthesis Example 1 Synthesis of Compound P-1

[0076]

[0077] Under nitrogen protection, 120 mL of toluene, 60 mL of ethanol and 25 mL of water were added to a 500 mL three-necked flask in sequence, and then 4.3 g of the raw material shown in M1, 1.8 g of 1-naphthaleneboric acid, 2.12 g (0.02 mol) of sodium carbonate and 0.23 g (0.0002 mol) of tetrakistriphenylphosphine palladium were added thereto. The temperature was slowly raised to reflux for reaction for 8 h, and the temperature was lowered to room temperature. Water was added to separate the organic layer, and the organic layer was washed with water, dried with magnesium sulfate, and after removing the desiccant, it was concentrated to dryness, separated by silica gel column chromatography, and eluted with petroleum ether to obtain 4.1 g of compound P-1.

[0078] The obtained compound P-1 was subjected to mass spectrometry detection, and the mass-to-charge ratio (m / z) was measured to be 477.21.

[0079] Synthesis Example 2-6

[0080] Referring to the synthesis method in Synthesis Example 1, the following compounds were synthesized by reacting a bromide with a boronic acid compound, and the mass spectrum of the prepared compounds was measured.

[0081]

[0082]

[0083]

[0084] The specific structures of several materials used in the following application examples are as follows:

[0085]

[0086] Among them, the synthesis method of BH7 is as follows:

[0087]

[0088] BH7 was prepared by referring to the synthesis of compound P-1. The mass spectrum of BH7 was measured, and the mass-to-charge ratio (m / z) was found to be 485.26.

[0089] Application Example 1

[0090] This application example provides an organic electroluminescent device, wherein the structure of the organic electroluminescent device is: ITO / HTL:HI-2(5%)(20nm) / HTL(50nm) / BH:BD-3(3%)(30nm) / TPBI(30nm) / Al(150nm);

[0091] The preparation method of the organic electroluminescent device is as follows:

[0092] Place each layer of material in a vacuum chamber and evacuate to 1×10 -5 ~1×10 -6 Pa, vacuum evaporated onto the cleaned ITO substrate in sequence. Among them, HTL:HI-2 (5%) (20nm) means that in this device, HTL and HI-2 are co-evaporated at a volume ratio of 95:5 to form a hole injection layer with a thickness of 20nm. BH:BD-3 (5%) (30nm) means that BH and BD-3 are co-evaporated at a volume ratio of 95:5 to form a light-emitting layer with a thickness of 30nm.

[0093] BH is a blue light host material. In this application example, BH is compound P-7.

[0094] In the device provided in this application example, HTL:HI-2(5%) (20 nm) is a hole injection layer, and HTL (50 nm) is a hole transport layer.

[0095] Application Example 2-8

[0096] Application Examples 2-8 respectively provide an organic electroluminescent device, which differs from Application Example 1 only in that the BH material is different, and in addition, the BD material is different (BD-3 is replaced as needed), (the specific composition is described in Table 1 below), and the other preparation steps are the same as Application Example 1.

[0097] Comparative Application Examples 1-7

[0098] Comparative Application Examples 1-7 respectively provide an organic electroluminescent device, which differs from Application Example 1 only in that the BH material is different (as described in Table 1 below), and the other preparation steps are the same as those of Application Example 1.

[0099] Performance Testing

[0100] Test method: The OLED-1000 multi-channel accelerated aging life and light color performance analysis system produced by Hangzhou Yuanfang was used for testing. The test items included the brightness, driving voltage, current efficiency, and LT80 of the organic electroluminescent device; LT80 refers to maintaining the initial brightness of the device at 1000cd / m 2 The current density remains unchanged, the device is placed in an environment of 90°C, and the device efficiency is measured to drop to the initial brightness of 1000cd / m 2 The time required for the corresponding efficiency to reach 80%. The driving voltage, current efficiency, and LT80 are all relative values.

[0101] The specific test results are shown in Table 1 below:

[0102] Table 1

[0103]

[0104] As can be seen from the contents of Table 1, the present invention designs the structure of the compound so that in the compound of a specific structure, only the H atoms on the dibenzofuran group are completely replaced by deuterium atoms, and the connection position of the dibenzofuran and the anthracene ring is limited, so that the obtained compound is relatively stable and has good film-forming properties when preparing devices. When used to prepare organic electroluminescent devices, the device voltage and efficiency are better, and the high-temperature life performance is higher.

[0105] In addition, by comparing Application Examples 7-9 with Application Examples 1-4, it can be seen that when n=8 in the compound represented by formula (I) of the present invention, the device life is better, and when n=0, the device efficiency is higher.

[0106] In addition, according to the comparison between Application Example 1 and Application Examples 5-6, it can be seen that when the compound of the present invention is used as a blue light host material and is used in combination with a compound having a structure shown in Formula BDI, the performance is further improved.

[0107] The applicant declares that 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 compound, characterized in that The compound is selected from the following structures:

2. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode, a cathode and an organic thin film layer disposed between the anode and the cathode, wherein the organic thin film layer comprises the compound according to claim 1. 3 . The organic electroluminescent device according to claim 2 , wherein the organic thin film layer comprises a light-emitting layer, and a material of the light-emitting layer comprises the compound according to claim 1 .

4. The organic electroluminescent device according to claim 3, characterized in that: The material of the light-emitting layer also includes a doping material, and the doping material has a structure shown in Formula II: Among them, Ar 21 ,Ar 22 Each is independently selected from any one of substituted aryl, substituted or unsubstituted C3-C20 heteroaryl; R 21 , R 22 and R 23 Each is independently selected from any one of hydrogen, C1-C12 straight or branched alkyl, and C6-C12 cycloalkyl; Ar 21 ,Ar 22 The substituents in the substitution are each independently selected from C1-C5 straight or branched chain alkyl or C6-C12 aryl.

5. The organic electroluminescent device according to claim 3, characterized in that: The material of the light-emitting layer also includes a doping material, and the doping material has a structure shown in Formula III: Ar 31 ,Ar 32 ,Ar 33 and Ar 34 Each is independently selected from any one of a substituted or unsubstituted C6-C22 aryl group and a substituted or unsubstituted C12-C40 heteroaryl group; R 31 Any one selected from phenyl, naphthyl or biphenyl; a is selected from 0 or 1; Ar 31 ,Ar 32 ,Ar 33 ,Ar 34 The substituents in the substitution are each independently selected from C1-C5 straight or branched chain alkyl or C6-C12 aryl.

6. The organic electroluminescent device according to claim 3, characterized in that: The material of the light-emitting layer also includes a doping material, and the doping material has a structure shown in the formula BDI: Ar 101 ,Ar 102 ,Ar 201 ,Ar 202 Each is independently selected from any one of a substituted or unsubstituted C6-C40 aryl group and a substituted or unsubstituted C12-C20 heteroaryl group; m is selected from 0 or 1; Ar 101 ,Ar 102 ,Ar 201 ,Ar 202 The substituted substituent is selected from any one of -D, -F, -CN, C1-C12 alkyl, C1-C6 alkoxy, C6-C20 aryl, and C12-C20 heteroaryl, or a combination of at least two thereof.

7. A display device, characterized in that: The display device comprises the compound according to claim 1.

8. A display device, characterized in that: The display device comprises the organic electroluminescent device according to any one of claims 2 to 6.

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