Indole spirofluorene organic compound, organic electroluminescent device and display device

Abstract

The present invention provides an indole spirofluorene organic compound, an organic electroluminescent device and a display device. The organic compound of the present invention can be used as a phosphorescent main material or a hole transport material of a light-emitting layer of an OLED light-emitting device. As a hole transport material, the organic electroluminescent device has a lower driving voltage, high current efficiency and a longer lifespan. As a main material of the light-emitting layer, the device has a lower driving voltage and high current efficiency.

Description

Technical Field

[0001] The invention belongs to the field of electroluminescence, and particularly relates to an indole spirofluorene compound, an organic electroluminescent device and a display device. Background Art

[0002] Currently, organic electroluminescent (OLED) display technology has been applied in smart phones, tablet computers and other fields, and will be further expanded to large-size application fields such as televisions. In the past 30 years of development, people have developed various OLED materials with excellent performance, and through different designs of device structures and optimization of device performance such as life and efficiency, the commercialization process of OLED has been accelerated, making OLED widely used in the display and lighting fields.

[0003] The selection of materials for the hole layer, light-emitting layer and other organic functional layers also has a significant impact on the current efficiency, driving voltage and life of the device. Currently, we are still exploring functional layer materials with higher performance.

[0004] Therefore, in order to meet people's higher requirements for OLED devices, the field is in urgent need of developing more types of OLED materials with higher performance. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide an indole spirofluorene organic compound, an organic electroluminescent device and a display device. The organic compound of the present invention can be used as a phosphorescent host material or a hole transport material of an OLED light-emitting device.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides an indole spirofluorene organic compound having a structure as shown in the following formula (I):

[0008]

[0009] Ar1 is selected from substituted or unsubstituted C6-C40 aryl, substituted or unsubstituted C5-C40 heteroaryl or substituted or unsubstituted C1-C12 alkyl;

[0010] Ar2 is selected from substituted or unsubstituted C6-C40 aryl, substituted or unsubstituted C5-C40 heteroaryl;

[0011] Ar3 is selected from substituted or unsubstituted C6-C40 aryl groups;

[0012] Ar2 and Ar3 exist alone or the sp2-hybridized carbon atoms in Ar2 and Ar3 are connected to form a ring through single bonds;

[0013] When Ar1 is selected from phenyl, and one of Ar2 and Ar3 is selected from biphenyl, the other of Ar2 and Ar3 is not biphenyl, When Ar1 is selected from phenyl, Ar2 and Ar3 are not simultaneously When Ar1 is selected from phenyl, one of Ar2 and Ar3 is selected from When the other is not selected When Ar1 is selected from phenyl, one of Ar2 and Ar3 is selected from When the other is not selected

[0014] When the substituted or unsubstituted group contains a substituent, the substituent is selected from F, CN, deuterium, C1-C6 alkyl, C1-C6 alkoxy, and C6-C40 aryl.

[0015] In the present invention, the range of carbon atom number is defined in the definition of the group, and the carbon atom number is any integer within the defined range. For example, C6-C40 aromatic group, the carbon atom number representing the aromatic group can be any integer within the range of 6-40, such as 6, 8, 10, 15, 20, 30, 35, 38 or 40, etc. The defined range of carbon atom number of other groups has the same meaning by analogy.

[0016] Preferably, at least one of Ar1 and Ar2 is selected from substituted or unsubstituted C5-C40 heteroaryl groups.

[0017] Preferably, the C6 to C40 aromatic group is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthfluoroenyl, pyrene, perylenyl, spirofluorenyl, triphenylene, fluoranthenyl, hydrogenated benzanthryl, indenofluorenyl, benzoindenofluorenyl, dibenzoindenofluorenyl, naphthfluoroenyl or benzonaphthofluorenyl, or a combination of two or more thereof.

[0018] Preferably, the C5-C40 heteroaryl group is selected from dibenzofuranyl, dibenzothiophenyl, benzodibenzofuranyl, benzodibenzothiophenyl, dibenzodibenzofuranyl, dibenzodibenzothiophenyl, naphthodibenzofuranyl, naphthodibenzothiophenyl, benzonaphthodibenzofuranyl or benzonaphthodibenzothiophenyl.

[0019] Preferably, Ar1 is selected from phenyl, biphenyl, methyl, ethyl, propyl, butyl, pentyl or hexyl.

[0020] Preferably, Ar2 is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthfluoroenyl, pyrenyl, peryl, spirofluorenyl, triphenylene, fluoranthenyl, hydrogenated benzanthryl, indenofluorenyl, benzoindenofluorenyl, dibenzoindenofluorenyl, naphthfluoroenyl, benzonaphthyl, dibenzofuranyl, dibenzothiophenyl, benzodibenzofuranyl or benzodibenzothiophenyl.

[0021] Preferably, the indole spirofluorene organic compound is any one of the following compounds:

[0022]

[0023]

[0024]

[0025] In the present invention, the synthetic route of the organic compound is as follows:

[0026]

[0027] In another aspect, the present invention provides a light-emitting layer, wherein the light-emitting layer comprises the indolospirofluorene organic compound as described above.

[0028] In another aspect, the present invention provides a hole transport layer, wherein the hole transport layer comprises the indolospirofluorene organic compound as described above.

[0029] In another aspect, the present invention provides an organic electroluminescent device, comprising the indolospirofluorene organic compound as described above.

[0030] Preferably, the organic electroluminescent device comprises an anode, a cathode and an organic thin film layer disposed between the anode and the cathode, and the organic thin film layer comprises the indole spirofluorene organic compound as described above.

[0031] Preferably, the organic thin film layer comprises a hole transport layer, and the hole transport layer comprises the indolospirofluorene organic compound as described above.

[0032] Preferably, the organic thin film layer comprises a light-emitting layer, and the light-emitting layer comprises the organic compound as described above.

[0033] In the present invention, the indole spirofluorene organic compound is used as the phosphorescent host material of the light-emitting layer.

[0034] In another aspect, the present invention provides a display device, comprising the organic electroluminescent device as described above.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The organic compound of the present invention can be used as a phosphorescent main material or a hole transport material of the light-emitting layer of an OLED light-emitting device. As a hole transport material, the organic electroluminescent device has a lower driving voltage (below 5.11 V), and at the same time has a high current efficiency (above 33.2 cd / A) and a longer life (above 62 h, or even up to 109 h). As a main material of the light-emitting layer, the device has a lower driving voltage (below 5.56 V) and a high current efficiency (above 8.76 cd / A). DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described below by specific implementation methods. 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.

[0038] Synthesis Example 1 Synthesis of Compound 1

[0039]

[0040] In a 250mL three-necked flask, add M-1-1 (5.6g, 0.01mol) and M-1-2 (2.5g, 0.01mol), add 100mL of toluene, add sodium tert-butoxide (1.2g, 0.013mol), Pd2(dba)3 (0.046g, 0.00005mol) under stirring, replace nitrogen, add 0.2g of 10% toluene solution of tri-tert-butylphosphine, start heating, slowly raise the temperature to 80°C (keep nitrogen protection during the reaction process), react for 2 hours, HPLC detection (M-1-1<1%), stop the reaction, and cool to room temperature. Wash with brine twice, add anhydrous sodium sulfate to dry the organic phase; column chromatography, use toluene as eluent; concentrate to obtain a crude product, recrystallize from toluene, and obtain 5.7g of compound 1 with HPLC purity>99%.

[0041] The mass spectrometry of compound 1 was performed to determine the m / z of the molecule to be 724.29.

[0042] Compound 1 was subjected to NMR detection, and the data analysis is as follows: 1H-NMR (Bruker, Switzerland, AvanceⅡ400MHz NMR spectrometer, CDCl3): δ8.57 (m, 1H), δ8.34 (s, 1H) δ8.22 (s, 1H), δ8.19 (d, 1H), δ7.86 (m, 2H), δ7.80~7.72 (m, 4H), δ7.67~7.34 (m, 15H), δ7.28~7.18 (m, 6H), δ7.17~7.05 (m, 4H), δ6.99 (m, 1H).

[0043] Synthesis Example 2 Synthesis of Compound 7

[0044]

[0045] The synthesis method refers to the synthesis of compound 1 in Example 1, except that the compound represented by M-1-2 is replaced by the compound represented by M-7-2.

[0046] The compound 7 was detected by mass spectrometry and the m / z of the molecule was determined to be 864.31.

[0047] Synthesis Example 3 Synthesis of Compound 21

[0048]

[0049] The synthesis method refers to the synthesis of compound 1 in Example 1, except that the compound represented by M-1-2 is replaced by the compound represented by M-21-2.

[0050] The compound 21 was detected by mass spectrometry and the m / z of the molecule was determined to be 722.27.

[0051] Synthesis Example 4 Synthesis of Compound 26

[0052]

[0053] The synthesis method refers to the synthesis of compound 1 in Example 1, except that the compound represented by M-1-2 is replaced by the compound represented by M-26-2.

[0054] The compound 26 was detected by mass spectrometry, and the m / z of the molecule was determined to be 762.30.

[0055] Synthesis Example 5 Synthesis of Compound 31

[0056]

[0057] The synthesis method refers to the synthesis of compound 1 in Example 1, except that the compound represented by M-1-2 is replaced by the compound represented by M-31-2.

[0058] The compound 31 was detected by mass spectrometry and the m / z of the molecule was determined to be 736.25.

[0059] Synthesis Example 6 Synthesis of Compound 41

[0060]

[0061] (1) Synthesis of compound M-41-1:

[0062] In a 500 ml three-necked flask, under nitrogen protection, add 200 ml acetone, 4.84 g (0.01 mol) of the compound shown in M-41-0, 2.18 g (0.02 mol) of ethyl bromide, and 1 g (0.025 mol) of sodium hydroxide. Stir at room temperature for 48 hours, add water and dichloromethane for separation, wash the organic layer with water until neutral, dry it with magnesium sulfate, filter out the magnesium sulfate, concentrate to dryness, and recrystallize with a mixed solvent of methanol and chloroform to obtain 4.6 g of the compound shown in formula M-41-1.

[0063] The intermediate shown in formula M-41-1 was detected by mass spectrometry. The two peaks with the largest m / z were 511.09 and 513.09. The molecular formula of the product was determined to be C 33 H 22 BrN.

[0064]

[0065] (2) Synthesis of Compound 41:

[0066] The synthesis method refers to the synthesis of compound 1 in Example 1, except that the compound represented by M-1-2 is replaced by the compound represented by M-41-2, and the compound represented by M-1-1 is replaced by the compound represented by M-41-1.

[0067] The compound 41 was detected by mass spectrometry, and the m / z of the molecule was determined to be 676.29.

[0068] Synthesis Example 7 Synthesis of Compound 57

[0069]

[0070] The synthesis method refers to the synthesis of compound 1 in Example 1, except that the compound represented by M-1-2 is replaced by the compound represented by M-57-2.

[0071] Compound 57 was detected by mass spectrometry, and the m / z of the molecule was determined to be 789.31.

[0072] Synthesis Example 8 Synthesis of Compound 60

[0073]

[0074] (1) Synthesis of intermediate M-60-1

[0075] Under nitrogen protection, M-41-0 (4.84 g, 0.01 mol) and 2-iodobiphenyl (2.80 g, 0.01 mol) were added to a 250 mL three-necked flask, and 50 mL of DMF was added. Potassium hydroxide (0.84 g, 0.015 mol) and cuprous iodide (2 g) were added under stirring, and the mixture was heated to 150 ° C for 6 hours. The reaction was stopped, the reaction solution was cooled, 50 mL of water was added, solid precipitated, filtered, and a crude product was obtained. It was recrystallized from toluene to obtain 3.1 g of intermediate M-60-1 with an HPLC purity of 98%.

[0076] The intermediate represented by formula M-60-1 was subjected to mass spectrometry detection, and the two peaks with the largest m / z were: 635.12 and 637.12. The molecular formula of the product was determined to be C43H26BrN.

[0077]

[0078] (2) Synthesis of Compound 60:

[0079] The synthesis method refers to the synthesis of compound 1 in Example 1, except that the compound represented by M-1-2 is replaced by the compound represented by M-60-2, and the compound represented by M-1-1 is replaced by the compound represented by M-60-1.

[0080] Compound 60 was detected by mass spectrometry, and the m / z of the molecule was determined to be 814.30.

[0081] Similarly, other compounds of the present invention can be prepared using the same preparation method as the above compounds. For example, compounds 2, 3, 25, 29 and 50 were prepared in the same manner, and the correctness of their molecules was confirmed by mass spectrometry.

[0082] The structures of the compounds used in the device examples are as follows. All organic OLED materials are sublimated to a HPLC purity of more than 99.99%.

[0083]

[0084] Device Example 1

[0085] This application example provides an OLED device, and the preparation method of the OLED device is as follows:

[0086] (1) A transparent electrode indium tin oxide (ITO) film (15 Ω / sq, Samsung Corning, South Korea) on a glass substrate for an organic light emitting diode (OLED) device was ultrasonically cleaned with trichloroethylene, acetone, ethanol, and distilled water in sequence and then stored in isopropyl alcohol; the ITO substrate was mounted on a substrate fixture of a vacuum vapor deposition apparatus.

[0087] (2) In the chamber of the vacuum vapor deposition equipment, the chamber pressure reaches 10 -6 After the support, the HIL material was vacuum evaporated to form a hole injection layer with a thickness of 60 nm on the ITO substrate.

[0088] (3) Compound 1 was vacuum-deposited on the hole injection layer formed above to form a hole transport layer with a thickness of 20 nm.

[0089] (4) Compounds I-40 and D-1 were vacuum-deposited on the hole transport layer to form a light-emitting layer with a thickness of 30 nm, wherein the volume ratio of CBP to D-1 was 90:10.

[0090] (5) On the light-emitting layer formed above, an ETL was vacuum-deposited to form an electron transport layer with a thickness of 30 nm on the light-emitting layer.

[0091] (6) On the electron transport layer, 8-hydroxyquinoline lithium (EIL) was vacuum-deposited to a thickness of 2 nm as an electron injection layer (EIL).

[0092] (7) Vacuum evaporating an Al cathode with a thickness of 150 nm on the electron injection layer to obtain the OLED device.

[0093] Device Examples 2-8

[0094] The device preparation method is the same as that of device embodiment 1, except that the hole transport material is different, as shown in Table 1 for details.

[0095] Device Comparison Examples 1-3

[0096] The device preparation method is the same as that of device embodiment 1, except that the hole transport material is different, as shown in Table 1 for details.

[0097] Performance testing of OLED devices

[0098] The driving voltage, current efficiency and life LT90 of the OLED devices provided above were tested using the OLED-1000 multi-channel accelerated aging life and light color performance analysis system produced by Hangzhou Yuanfang; where LT90 refers to the time required for the brightness to drop to 90% of the original brightness while maintaining the current density unchanged at the initial brightness of 1000nit.

[0099] The specific test results are shown in Table 1:

[0100] Table 1

[0101]

[0102] It can be seen from Table 1 that when the compounds of the present invention are used as hole transport materials, the OLED device can have a lower driving voltage (below 5.11 V), a high current efficiency (above 33.2 cd / A) and a longer life (above 62 h, even up to 109 h).

[0103] Device Examples 12-15 and Comparative Example 4

[0104] The example uses the compound of the present invention as the blue light host material in the organic electroluminescent device, and the comparative example uses CBP as the blue light host material in the organic electroluminescent device.

[0105] The structure of the organic electroluminescent device is: ITO / HIL (50nm) / HTL (20nm) / blue light host material (35nm): Firpic [8%] / ETL (10nm) / Alq3 (15nm) / LiF (0.5nm) / Al (150nm). "Firpic [8%]" refers to the doping ratio of the blue light dye, that is, the volume ratio of the blue light host material to Firpic is 100:8.

[0106] The organic electroluminescent device was prepared as follows: a glass plate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0107] The glass substrate with the anode is placed in a vacuum chamber, and the vacuum is evacuated to 1×10-5~9×10-4Pa. A hole injection layer HIL is vacuum-deposited on the anode layer film, and the deposition rate is 0.01nm / s, and the deposition film thickness is 50nm;

[0108] A hole transport layer HTL is vacuum-deposited on the hole injection layer at a rate of 0.01 nm / s and a thickness of 20 nm;

[0109] The blue light host material and the dye Firpic are vacuum-deposited on the hole transport layer as the light-emitting layer of the organic electroluminescent device, with a deposition rate of 0.01 nm / s and a total deposition film thickness of 35 nm;

[0110] The electron transport layer ETL and Alq3 were vacuum-deposited on the light-emitting layer in sequence, with the evaporation rate of both being 0.01 nm / s and the thickness of the evaporated films being 10 nm and 15 nm respectively;

[0111] 0.5 nm of LiF and 150 nm of Al were vacuum-deposited on the electron transport layer as the electron injection layer and cathode.

[0112] All organic electroluminescent devices are prepared by the above method, and the only difference is the selection of blue light host materials, as shown in Table 2 below.

[0113] Performance Test:

[0114] The brightness, driving voltage and current efficiency of the prepared organic electroluminescent device were measured using the OLED-1000 multi-channel accelerated aging life and light color performance analysis system produced by Hangzhou Yuanfang. The test results are shown in Table 2 below.

[0115] Table 2

[0116]

[0117]

[0118] It can be seen from Table 2 that when the compound of the present invention is used as a blue light host material, the OLED device can have a lower driving voltage (below 5.56 V) and a high current efficiency (above 8.76 cd / A).

[0119] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the organic compound, organic electroluminescent device and display device of the present invention, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments 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. An indolospirofluorene organic compound, wherein the organic compound has a structure as shown in the following formula (I): Ar1 is selected from substituted or unsubstituted phenyl, biphenyl, methyl, ethyl, propyl, butyl, pentyl or hexyl; when the substituted or unsubstituted group in Ar1 contains a substituent, the substituent is selected from deuterium; Ar2 is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthfluoroenyl, pyrenyl, peryl, spirofluorenyl, triphenylene, fluoranthenyl, hydrogenated benzanthryl, indenofluorenyl, benzoindenofluorenyl, dibenzoindenofluorenyl, naphthfluoroenyl, benzonaphthyl, dibenzofuranyl, dibenzothiophenyl, benzodibenzofuranyl or benzodibenzothiophenyl; Ar3 is selected from substituted or unsubstituted phenyl, wherein the substituent is selected from F, CN, deuterium, C1-C6 alkyl, naphthyl; Ar2 and Ar3 exist alone or the sp2 hybridized carbon atoms in Ar2 and Ar3 are linked by single bonds to form a ring.

2. An indolospirofluorene organic compound, characterized in that: The indolospirofluorene organic compound is any one of the following compounds:

3. A light-emitting layer, characterized in that: The light-emitting layer comprises the indolospirofluorene organic compound according to any one of claims 1 to 2.

4. A hole transport layer, characterized in that: The hole transport layer comprises the indolospirofluorene organic compound according to any one of claims 1 to 2.

5. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the indolospirofluorene organic compound according to any one of claims 1 to 2.

6. The organic electroluminescent device according to claim 5, 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 indole spirofluorene organic compound according to any one of claims 1 to 2.

7. The organic electroluminescent device according to claim 6, characterized in that: The organic thin film layer comprises a hole transport layer, and the hole transport layer comprises the indolospirofluorene organic compound according to any one of claims 1 to 2.

8. The organic electroluminescent device according to claim 6, characterized in that: The organic thin film layer comprises a light-emitting layer, and the light-emitting layer comprises the indole spirofluorene organic compound according to any one of claims 1 to 2.

9. The organic electroluminescent device according to claim 8, characterized in that: The indole spirofluorene organic compound is used as the phosphorescent host material of the light-emitting layer.

10. A display device, characterized in that: The display device comprises the organic electroluminescent device according to any one of claims 5 to 9.

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