Blue light-emitting compound containing acenaphthene structure, organic electroluminescent device containing blue light-emitting compound and display device containing blue light-emitting compound

Abstract

The invention discloses a blue light-emitting compound containing an acenaphthene structure, and an organic electroluminescent device and a display device comprising the same. The structural general formula of the blue light-emitting compound is shown as a formula I. The acenaphthene benzofuran is introduced into the structure, so that the benzofuran structure is further conjugated, and the increase of the pi conjugation degree is beneficial to the improvement of the quantum efficiency and the charge transfer efficiency. In addition, the acenaphthene benzofuran structure can improve the stability of the material. Besides, the acenaphthene benzofuran structure also increases the planarity of the host material, is beneficial to reducing the driving voltage of the organic electroluminescent device, can effectively reduce the energy loss, and can effectively improve the efficiency and prolong the service life of the organic electroluminescent device as a luminescent layer host material. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the technical field of OLEDs, and specifically comprises a blue light-emitting compound containing an acenaphthylene structure, and an organic electroluminescent device and a display device containing the same. Background Art

[0002] Organic Light Emitting Diodes (OLEDs) are a highly popular display technology. Thanks to innovations in OLED device structure and the use of highly efficient transmission, host, luminescent, and injection materials, OLED-based display and lighting applications have become one of the most competitive technologies available. OLED technology has captured global attention due to its high efficiency, lightweight design, high color quality, near-180° viewing angle, ultra-fast response, and potential for true black display.

[0003] Currently, the light-emitting layers of blue organic electroluminescent devices almost all utilize a host-guest doped luminescence system, whereby electroluminescence is achieved by doping a host material with a guest dopant. Commonly used blue fluorescent devices primarily utilize anthracene-based host materials. However, currently used anthracene-based host materials, such as those disclosed in patent KR1020210022419A, still have some pressing challenges in terms of lifetime, color purity, and device efficiency.

[0004] Therefore, it is very important to develop a blue light host material with better performance. Summary of the Invention

[0005] In view of the above problems existing in the prior art, the present invention provides a blue light-emitting compound containing an acenaphthylene structure and an organic electroluminescent device and a display device containing the same.

[0006] To achieve the above objectives, the technical solutions adopted by the present invention include:

[0007] The first aspect of the present invention provides a blue light-emitting compound containing an acenaphthylene structure, the general structural formula of the blue light-emitting compound is shown in Formula I:

[0008]

[0009] Wherein, L1 and L2 each independently represent a single bond, a substituted or unsubstituted arylene group having carbon atoms of C6 to C12;

[0010] Ar represents any one of a substituted or unsubstituted aryl group having C6 to C60 carbon atoms, a substituted or unsubstituted heteroaryl group having C5 to C60 carbon atoms, a substituted or unsubstituted fused ring aryl group having C6 to C60 carbon atoms, and a substituted or unsubstituted heterofused ring aryl group having C5 to C60 carbon atoms;

[0011] In Formula I, any hydrogen may be replaced by deuterium, any nitrogen may be replaced by nitrogen-15, any sulfur may be replaced by sulfur-33, sulfur-34 or sulfur-36, any oxygen may be replaced by oxygen-17 or oxygen-18, any carbon may be replaced by carbon-13, and any boron may be replaced by boron-11.

[0012] Furthermore, the blue light-emitting compound is selected from one of the following structural formulas:

[0013]

[0014] Furthermore, L1 and L2 each independently represent a single bond, a substituted or unsubstituted phenylene group or a naphthylene group.

[0015] Furthermore, L1 and L2 each independently represent a single bond, Any one of, preferably a single bond, Any one of .

[0016] Furthermore, at least one of L1 and L2 is selected from a single bond.

[0017] Further, said Ar represents

[0018] Any one of .

[0019] Further, said Ar represents Any of the following;

[0020] Indicates the position where Ar is attached to L1.

[0021] Furthermore, the blue light-emitting compound is selected from one of the following structures:

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034] The second aspect of the present invention provides a use of the above-mentioned blue light-emitting compound in preparing an organic electroluminescent device.

[0035] A third aspect of the present invention provides an organic electroluminescent device, which includes an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode sequentially arranged on a substrate; wherein the light-emitting layer includes a host material and a guest material, and the host material includes one or more blue light-emitting compounds as described above.

[0036] A fourth aspect of the present invention provides a display device comprising the above organic electroluminescent device.

[0037] Beneficial effects of the present invention:

[0038] The blue light host material provided by the present invention contains an acenaphthylene-benzofuran structure. Acenaphthylene and benzofuran are fused to further conjugate the benzofuran structure. The increase in the degree of π conjugation is beneficial for improving quantum efficiency and charge transfer efficiency. The acenaphthylene-benzofuran structure can increase the stability of the host material. In addition, the acenaphthylene-benzofuran structure also increases the planarity of the host material, which is beneficial for reducing the driving voltage of the organic electroluminescent device, can effectively reduce energy loss, and is beneficial for improving the efficiency and life of the organic electroluminescent device. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the structure of the organic electroluminescent device of the present invention.

[0040] Description of the drawings: 1-substrate, 2-anode, 3-hole injection layer, 4-hole transport layer, 5-electron blocking layer, 6-light-emitting layer, 7-hole blocking layer, 8-electron transport layer, 9-electron injection layer, 10-cathode, 11-covering layer. DETAILED DESCRIPTION

[0041] In order to more clearly understand the content of the present invention, it will be described in detail with reference to the accompanying drawings and embodiments.

[0042] The compounds of the present invention are suitable for use in light-emitting elements, display panels and electronic devices, and are particularly suitable for use in organic electroluminescent devices. The electronic device described in the present invention is a device comprising a layer of at least one organic compound, which may also comprise an inorganic material or a layer formed entirely of an inorganic material. The electronic device is preferably an organic electroluminescent device (OLED), an organic integrated circuit (O-IC), an organic field effect transistor (O-FET), an organic thin film transistor (O-TFT), an organic light-emitting transistor (O-LET), an organic solar cell (O-SC), an organic dye-sensitized solar cell (O-DSSC), an organic optical detector, an organic photoreceptor, an organic field quenching device (O-FQD), a light-emitting electrochemical cell (LEC), an organic laser diode (O-laser) and an organic plasma emission device. The electronic device is preferably an organic electroluminescent device (OLED). The structural schematic diagram of an exemplary organic electroluminescent device is shown in FIG. Figure 1 shown.

[0043] Experimental part

[0044] In order to understand the content of the present invention more clearly, the polycyclic compound, the preparation method of the compound and the luminescent characteristics of the device will be explained in detail in conjunction with the examples. Various chemical reactions can be applied to the synthetic method of the compound of one embodiment of the present invention. However, it should be noted that the synthetic method of the compound of one embodiment of the present invention is not limited to the synthetic method described below. Unless otherwise stated, subsequent synthesis is carried out in an anhydrous solvent under a protective gas atmosphere. Solvents and reagents can be purchased from conventional reagent suppliers.

[0045] Intermediate Synthesis Example 1

[0046]

[0047] Compound C-1 (100.0 g, 431 mmol), DDQ (146 g, 862 mmol), and toluene (1000 mL) were added to a round-bottom flask replaced with nitrogen, and the temperature was raised to 80°C with stirring and maintained for 24 h. The reaction mixture was then cooled to room temperature, diluted with ethyl acetate (500 ml), stirred for 30 min, washed with 10% K2CO3 solution, deionized water, and saturated sodium chloride solution, respectively. The organic phase was separated and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography (dichloromethane / n-heptane as mobile phase) and recrystallized from n-heptane to obtain intermediate D-1: 79.3 g, yield: 80%, MS (m / z) (M+): 230.

[0048] Compound D-1 (79.3 g, 345 mmol) and K2CO3 (142 g, 1034 mmol) were added to a round-bottom flask replaced with nitrogen. Under nitrogen protection, cuprous chloride (1.7 g, 17.24 mmol) and ethylene glycol (800 mL) were added to the reaction system. The temperature was raised to 130°C with stirring and maintained for 20 h. The reaction mixture was then cooled to room temperature and acidified to pH 3 with 1 mol / L dilute hydrochloric acid. The aqueous phase was extracted twice with ethyl acetate (250 ml), washed with deionized water and saturated sodium chloride solution, respectively, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate and the solvent was removed under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography (dichloromethane / n-heptane as the mobile phase) to obtain intermediate E-1: 40.5 g, yield: 70%, MS (m / z) (M+): 168.

[0049] Compound E-1 (40.5 g, 241 mmol) and DMF (500 mL) were added to a nitrogen-purged round-bottom flask, stirred and dissolved, and the temperature was lowered to -10°C. NBS (44.25 g, 248 mmol) was added in batches under nitrogen protection and maintained for 2 h. The reaction mixture was then warmed to room temperature and stirred for 2 h. Deionized water was added and stirred, and the organic phase was extracted three times with ethyl acetate (500 ml). The organic phase was washed and separated with saturated sodium chloride solution, and the organic phase was dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography (dichloromethane / n-heptane as mobile phase) to obtain intermediate F-1: 42.7 g, yield: 72%, MS (m / z) (M+): 246.

[0050] Compound F-1 (40 g, 162 mmol), M-1 (28.3 g, 162 mmol), tetrakis(triphenylphosphine)palladium (1.87 g, 1.62 mmol), potassium carbonate (44.7 g, 324 mmol), 1,4-dioxane (400 mL) and deionized water (100 mL) were added to a round-bottom flask replaced with nitrogen, and the temperature was raised to 90°C with stirring and maintained for 4 h; the reaction mixture was then cooled to room temperature, deionized water (100 mL) and ethyl acetate (500 ml) were added and stirred for 20 min, the organic phase was separated, and the organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure to obtain a crude product; the crude product was purified by silica gel column chromatography (dichloromethane / n-heptane as mobile phase) to obtain intermediate G-1: 38.5 g, yield: 80%, MS (m / z) (M+): 296.

[0051] To a dried and nitrogen-substituted round-bottom flask, add intermediate G-1 (38.5 g, 130 mmol), potassium carbonate (54 g, 390 mmol) and N-methylpyrrolidone (400 mL). Stir at 160 ° C for 2 h under nitrogen protection. Remove the solvent under reduced pressure to obtain a crude product. Wash the crude product with deionized water and ethanol, dry it, and purify it with silica gel column chromatography (dichloromethane / n-heptane as mobile phase) to obtain intermediate K-1: 26.5 g, yield: 74%, MS (m / z) (M+): 276.

[0052] To a nitrogen-purged round-bottom flask, intermediate K-1 (26.5 g, 96.2 mmol), trimethyl borate (10 g, 96.5 mmol), and tetrahydrofuran (300 mL) were added. Under nitrogen protection, tert-butyl lithium (76.9 mL, 192.4 mmol) was added dropwise at -50°C. The addition was completed within 2 h. The mixture was kept warm for 3 h. Then, 40 mL of 5% hydrochloric acid solution was added and stirring was continued for 2 h. The tetrahydrofuran was evaporated under reduced pressure. The temperature was raised to -10°C to produce a solid precipitate. The solid precipitate was filtered and dried to obtain 22 g of intermediate T-1, with a yield of 80%. MS (m / z) (M+): 286.

[0053] Intermediate Synthesis Example 2

[0054]

[0055] Similarly, referring to the synthesis method of G-1, the raw material M-1 was replaced with M-2 (28.3 g, 162 mmol) to obtain intermediate G-2: 37.5 g, yield: 78%, MS (m / z) (M+): 296.

[0056] Referring to the synthesis method of K-1, the raw material G-1 was replaced with G-2 (37.5 g, 127 mmol) to obtain intermediate K-2: 26.6 g, yield: 76%, MS (m / z) (M+): 276.

[0057] Referring to the synthesis method of T-1, the raw material K-1 was replaced with K-2 (26.6 g, 96.4 mmol) to obtain intermediate T-2: 22.6 g, yield: 82%, MS (m / z) (M+): 286.

[0058] Intermediate Synthesis Example 3

[0059]

[0060] Referring to the synthesis method of G-1, the raw material M-1 was replaced with M-3 (28.3 g, 162 mmol) to obtain intermediate G-3: 38 g, yield: 79%, MS (m / z) (M+): 296.

[0061] Referring to the synthesis method of K-1, the raw material G-1 was replaced with G-3 (38 g, 128 mmol) to obtain intermediate K-3: 27.6 g, yield: 78%, MS (m / z) (M+): 276.

[0062] Referring to the synthesis method of T-1, the raw material K-1 was replaced with K-3 (27.6 g, 100 mmol) to obtain intermediate T-3: 23.8 g, yield: 83%, MS (m / z) (M+): 286.

[0063] Intermediate Synthesis Example 4

[0064]

[0065] Referring to the synthesis method of G-1, the raw material M-1 was replaced with M-4 (28.3 g, 162 mmol) to obtain intermediate G-4: 36 g, yield: 75%, MS (m / z) (M+): 296.

[0066] Referring to the synthesis method of K-1, the raw material G-1 was replaced with G-4 (36 g, 122 mmol) to obtain intermediate K-4: 26.9 g, yield: 80%, MS (m / z) (M+): 276.

[0067] Referring to the synthesis method of T-1, the raw material K-1 was replaced with K-4 (26.9 g, 100 mmol) to obtain intermediate T-4: 20.6 g, yield: 74%, MS (m / z) (M+): 286.

[0068] Intermediate Synthesis Example 5

[0069]

[0070] Under argon, compound K-4 (26.9 g, 100 mmol) and AlCl₃ (6.7 g, 50 mmol) were added to a round-bottom flask, followed by dissolution with C₂D₆ (500 mL). The mixture was allowed to react at 80°C for 24 h. After completion, the mixture was cooled and washed with D₂O (20 mL x 2). The organic phase was dried over anhydrous magnesium sulfate and concentrated in vacuo. The crude product was then purified by celite and recrystallization. The D content (%) was determined by HNMR. The final product, L-4, was obtained: 17.1 g (yield 60%), MS (m / z) (M+): 285.

[0071] Referring to the synthesis method of T-1, the raw material K-1 was replaced with L-4 (14 g, 50 mmol) to obtain intermediate T-5: 10.6 g, yield: 71.8%, MS (m / z) (M+): 295.

[0072] Synthesis Example 1

[0073]

[0074] Under nitrogen protection, 50 mL of toluene, 25 mL of water, and 25 mL of ethanol were added to 250 mL, and then compound A-1 (6.64 g, 20 mmol), compound T-4 (5.72 g, 20 mmol), potassium carbonate (4.15 g, 30 mmol), and tetrakistriphenylphosphine palladium (0.46 g, 0.4 mmol) were added. The reaction was carried out at 80 ° C for 10 h, cooled to room temperature, and filtered to obtain a crude product. The crude product was dissolved in toluene and passed through a chromatography column to remove the catalyst. After recrystallization, the product B-1: 7.8 g (yield 79%), MS (m / z) (M +): 494.

[0075] Synthesis Example 2

[0076]

[0077] The preparation method is similar to that of B-1, except that T-3 (5.72 g, 20 mmol) replaces T-4, and the final product B-2 is 8.2 g (yield 83%), MS (m / z) (M+): 494.

[0078] Synthesis Example 3

[0079]

[0080] The preparation method is similar to that of B-1, except that T-2 (5.72 g, 20 mmol) replaces T-4, and the final product B-3 is 7.6 g (yield 77%), MS (m / z) (M+): 494.

[0081] Synthesis Example 4

[0082]

[0083] The preparation method is similar to that of B-1, except that T-1 (5.72 g, 20 mmol) replaces T-4, and the final product B-4 is 8.1 g (yield 82%), MS (m / z) (M+): 494.

[0084] Synthesis Example 5

[0085]

[0086] The preparation method is similar to that of B-1, except that A-2 (8.16 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and the final product B-5 is 9.1 g (yield 80%), MS (m / z) (M+): 570.

[0087] Synthesis Example 6

[0088]

[0089] The preparation method is similar to that of B-1, except that A-3 (7.64 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-3 (5.72 g, 20 mmol) replaces T-4. The final product B-6 is 8.4 g (yield 77%), MS (m / z) (M+): 544.

[0090] Synthesis Example 7

[0091]

[0092] The preparation method is similar to that of B-1, except that A-4 (7.64 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-1 (5.72 g, 20 mmol) replaces T-4. The final product B-7 is 7.7 g (yield 71%), MS (m / z) (M+): 544.

[0093] Synthesis Example 8

[0094]

[0095] The preparation method is similar to that of B-1, except that A-5 (9.16 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-2 (5.72 g, 20 mmol) replaces T-4. The final product B-8 is 8.8 g (yield 71%), MS (m / z) (M+): 620.

[0096] Synthesis Example 9

[0097]

[0098] The preparation method is similar to that of B-1, except that A-6 (9.24 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-1 (5.72 g, 20 mmol) replaces T-4. The final product B-9 is 9.4 g (yield 75%), MS (m / z) (M+): 624.

[0099] Synthesis Example 10

[0100]

[0101] The preparation method is similar to that of B-1, except that A-7 (9.16 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-2 (5.72 g, 20 mmol) replaces T-4. The final product B-10 is 8.6 g (yield 69%), MS (m / z) (M+): 620.

[0102] Synthesis Example 11

[0103]

[0104] The preparation method is similar to that of B-1, except that A-8 (9.16 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-3 (5.72 g, 20 mmol) replaces T-4. The final product B-11 is 9.4 g (yield 76%), MS (m / z) (M+): 620.

[0105] Synthesis Example 12

[0106]

[0107] The method is similar to that of preparing B-1, except that A-9 (8.26 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and the final product B-12 is 9.9 g (yield 83%), MS (m / z) (M+): 575.

[0108] Synthesis Example 13

[0109]

[0110] The preparation method is similar to that of B-1, except that A-1 (6.64 g, 20 mmol) is replaced by A-10 (9.68 g, 20 mmol), and the final product B-13 is 10.3 g (yield 80%), MS (m / z) (M+): 646.

[0111] Synthesis Example 14

[0112]

[0113] The preparation method is similar to that of B-1, except that A-11 (9.16 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-3 (5.72 g, 20 mmol) replaces T-4. The final product B-14 is 9.2 g (yield 74%), MS (m / z) (M+): 620.

[0114] Synthesis Example 15

[0115]

[0116] The preparation method is similar to that of B-1, except that A-12 (9.16 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-1 (5.72 g, 20 mmol) replaces T-4. The final product B-15 is 9.8 g (yield 79%), MS (m / z) (M+): 620.

[0117] Synthesis Example 16

[0118]

[0119] The preparation method is similar to that of B-1, except that A-1 (6.64 g, 20 mmol) is replaced by A-13 (10.68 g, 20 mmol). The final product B-16 is 9.19 g (yield 66%), MS (m / z) (M+): 696.

[0120] Synthesis Example 17

[0121]

[0122] The preparation method is similar to that of B-1, except that A-1 (6.64 g, 20 mmol) is replaced by A-14 (8.96 g, 20 mmol), and the final product B-17 is 8.54 g (yield 70%), MS (m / z) (M+): 610.

[0123] Synthesis Example 18

[0124]

[0125] The preparation method is similar to that of B-1, except that A-15 (8.44 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-1 (5.72 g, 20 mmol) replaces T-4. The final product B-18 is 8.8 g (yield 76%), MS (m / z) (M+): 584.

[0126] Synthesis Example 19

[0127]

[0128] The preparation method is similar to that of B-1, except that A-16 (8.44 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-2 (5.72 g, 20 mmol) replaces T-4. The final product B-19 is 8.4 g (yield 72%), MS (m / z) (M+): 584.

[0129] Synthesis Example 20

[0130]

[0131] Under argon, compound B-1 (4.94 g, 10 mmol) and AlCl₃ (0.67 g, 5 mmol) were added to a round-bottom flask, followed by dissolution with C₂D₆ (100 mL). The mixture was reacted at 80°C for 24 h. After completion, the mixture was cooled and washed with D₂O (20 mL x 2). The organic phase was dried over anhydrous magnesium sulfate and concentrated in vacuo. The crude product was then purified by celite and recrystallization. The D content (%) was determined by HNMR. The final product, B-20, was obtained: 3.3 g (yield 65%), MS (m / z) (M+): 516.

[0132] Synthesis Example 21

[0133]

[0134] The preparation method is similar to that of B-20, except that B-2 (4.94 g, 10 mmol) replaces B-1 (4.94 g, 10 mmol). The final product B-21 is 3.7 g (yield 72%), MS (m / z) (M+): 516.

[0135] Synthesis Example 22

[0136]

[0137] The preparation method is similar to that of B-20, except that B-3 (4.94 g, 10 mmol) replaces B-1 (4.94 g, 10 mmol). The final product B-21 is 3.6 g (yield 70%), MS (m / z) (M+): 516.

[0138] Synthesis Example 23

[0139]

[0140] The preparation method is similar to that of B-20, except that B-4 (4.94 g, 10 mmol) replaces B-1 (4.94 g, 10 mmol). The final product B-23 is 3.5 g (yield 68%), MS (m / z) (M+): 516.

[0141] Synthesis Example 24

[0142]

[0143] The preparation method is similar to that of B-1, except that T-5 (5.9 g, 20 mmol) replaces T-4, and the final product B-24 is 7.9 g (yield 79%), MS (m / z) (M+): 503.

[0144] Synthesis Example 25

[0145]

[0146] The preparation method is similar to that of B-1, except that A-17 (7.94 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and the final product B-25 is 9.0 g (yield 81%), MS (m / z) (M+): 559.

[0147] Synthesis Example 26

[0148]

[0149] The preparation method is similar to that of B-1, except that A-18 (7.80 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and the final product B-26 is 9.3 g (yield 84%), MS (m / z) (M+): 552.

[0150] Synthesis Example 27

[0151]

[0152] The preparation method is similar to that of B-1, except that A-1 (6.64 g, 20 mmol) is replaced by A-19 (6.80 g, 20 mmol), and the final product B-27 is 7.7 g (yield 77%), MS (m / z) (M+): 502.

[0153] Synthesis Example 28

[0154]

[0155] The preparation method is similar to that of B-1, except that A-17 (7.94 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and T-1 (5.72 g, 20 mmol) replaces T-4. The final product B-28 is 8.8 g (yield 79%), MS (m / z) (M+): 559.

[0156] Synthesis Example 29

[0157]

[0158] The preparation method is similar to that of B-1, except that A-20 (8.5 g, 20 mmol) replaces A-1 (6.64 g, 20 mmol), and the final product B-28 is 9.6 g (yield 82%), MS (m / z) (M+): 586.

[0159] Comparative compounds

[0160]

[0161]

[0162] Compound properties

[0163] Compounds prepared in the synthetic examples of the present invention and comparative compounds were subjected to thermal stability testing. The test steps were as follows: the test material was placed in a thermal stabilizer, sublimed at 280°C, and refined for 240 hours. The sublimated solid sample was then dissolved and diluted with mobile phase. The change in material purity before and after the experiment was measured using high-performance liquid chromatography. The smaller the purity difference, the better the material's thermal stability. As can be seen in the table below, the materials of the present invention exhibit significant improvements in thermal stability compared to compounds H1-H14.

[0164] Table 1

[0165]

[0166]

[0167]

[0168] Note: Purity change before and after the thermal stability test is ≤0.005% and is evaluated as "excellent"; purity change between greater than 0.005% and less than or equal to 0.01% is evaluated as "good"; purity change >0.01% is evaluated as "fair".

[0169] Fabrication and characterization of OLEDs

[0170] Device Examples

[0171] The organic electroluminescent device provided by the present invention comprises an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode which are sequentially arranged on a substrate;

[0172] Furthermore, the hole transport region includes a hole injection layer, a hole transport layer and a light-emitting auxiliary layer; and the electron transport region includes an electron transport layer and an electron injection layer.

[0173] Furthermore, the light-emitting layer is composed of a host material and a guest material, and the host material of the light-emitting layer can be composed of one molecular material or multiple molecular materials.

[0174] The composition of the present invention can be used in the light-emitting layer of the above-mentioned organic electroluminescent device.

[0175] The anode in the embodiment adopts anode materials commonly used in the art, such as ITO, Ag or its multilayer structure. The hole injection layer adopts hole injection materials commonly used in the art, and F4TCNQ, HATCN, NDP-9, etc. are added for doping. The hole transport layer adopts hole transport materials commonly used in the art. The light-emitting layer adopts the host and guest material composition provided by the present invention. The electron transport layer adopts electron transport materials commonly used in the art. The electron injection layer adopts electron injection materials commonly used in the art, such as Liq, LiF, Yb, etc. The cathode adopts materials commonly used in the art, such as metal Al, Ag or metal mixtures (Ag-doped Mg, Ag-doped Ca, etc.).

[0176] The electrode preparation method and the deposition method of each functional layer in this embodiment are conventional methods in the art, such as vacuum thermal evaporation or inkjet printing, and will not be described in detail here. Only some process details and testing methods in the preparation process are supplemented as follows:

[0177] Device Example 1

[0178] The substrates used in the present invention were subjected to the following operations: the ITO substrate was patterned to have a light-emitting area of ​​3 mm × 3 mm, and then ultrasonicated with water / isopropyl alcohol, irradiated with UV / ozone, and then dried at 100 ° C. After that, the ITO substrate was mounted on the substrate holder of the vacuum deposition device and the pressure was adjusted to a vacuum rate of 1 × 10 -7torr. Subsequently, on the ITO layer (anode) formed on the substrate, a hole injection layer was formed by vacuum depositing compound HTL and compound p-dopant (the mass ratio of compound HTL to compound p-dopant was 97:3) with a thickness of 10 nm; secondly, on the hole injection layer, a hole transport layer was formed by vacuum depositing compound HTL with a thickness of 120 nm; and secondly, on the hole transport layer, a light-emitting auxiliary layer was formed by vacuum depositing compound B-prime with a thickness of 5 nm; and again, on the light-emitting auxiliary layer, a mixture of compound B-1 and compound BD-1 was vacuum deposited with a thickness of 20 nm to form a light-emitting layer, wherein compound B-1 was used as a host and BD-1 was used as a dopant, and the mass ratio of the host to the dopant was 98:2; and then, on the light-emitting layer, compound HB was vacuum deposited with a thickness of 5 nm. L forms a hole blocking layer; a mixture of compound ETL and compound Liq (mass ratio of 1:1) is vacuum deposited with a thickness of 30 nm to form an electron transport layer; then, LiF is deposited with a thickness of 0.2 nm on the electron transport layer to form an electron injection layer, and finally, aluminum (Al) is deposited with a thickness of 150 nm on the electron injection layer to form a cathode, and then, compound CPL is deposited with a thickness of 50 nm on the cathode to form a covering layer. Finally, the vapor-deposited substrate is packaged, and the cleaned cover is coated with UV glue using a glue coating device. The coated cover is then moved to a pressing section, and the vapor-deposited substrate is placed on the upper end of the cover. Finally, the substrate and cover are bonded together using a bonding device, and the UV glue is light-cured to prepare a blue organic electroluminescent device. The device structure is shown in FIG. Figure 1 .

[0179] Except for the guest material of the light-emitting layer, the molecular structures of the materials in the remaining layers are as follows:

[0180]

[0181] Device Examples 2-29

[0182] The above method was used to prepare organic electroluminescent devices from the compounds described in other examples in Table 2. Specifically, blue organic electroluminescent devices of Examples 2-29 were prepared by replacing B-1 in Device Example 1 with the host materials shown in Table 2.

[0183] Device Comparative Examples 1-14

[0184] The above method was used to prepare organic electroluminescent devices from the compounds described in the comparative examples in Table 2. Specifically, blue organic electroluminescent devices of Comparative Examples 1-14 were prepared by replacing B-1 in Device Example 1 with the host materials shown in the comparative examples in Table 2.

[0185] The OLED devices described above were tested by standard methods. For this purpose, at J = 10 mA / cm 2 The driving voltage and luminous efficiency of the organic electroluminescent device are determined at a current density of J = 20 mA / cm 2 When working under , the luminous brightness drops to 97% of its initial value L0.

[0186] The test instruments and methods for performing performance tests on the OLED devices of the above embodiments and comparative examples are as follows:

[0187] Brightness was tested using a spectral scanner, PhotoResearch PR-635;

[0188] Luminous efficiency (CE) (cd / A) and color coordinates (CIEy) were measured using a spectral scanner, PhotoResearch PR-635.

[0189] Current density and turn-on voltage: tested using a Keithley 2400 digital source meter;

[0190] The luminous efficiency of blue light devices is greatly affected by chromaticity. The industry generally uses the BI value as the basis for the efficiency of blue light devices. The BI (Blue Index) is obtained by dividing the luminous efficiency CE (cd / A) by the color coordinate (CIEy).

[0191] Life test: Use silicon photoelectric OLED device life test system.

[0192] The test results are shown in Table 2.

[0193] Table 2 Blue light device performance test results

[0194]

[0195]

[0196]

[0197] It can be seen from the test results provided by device examples 1-29 and device comparison examples 1-14 that the organic electroluminescent device containing the blue light host material provided by the present invention has significant advantages in driving voltage, luminous efficiency and lifespan.

[0198] Compared to Comparative Device Examples 1-14, the blue light host material of the device embodiment of the present invention contains acenaphthylenebenzofuran. Acenaphthylene is fused with benzofuran, further conjugating the benzofuran structure. The increase in the degree of π conjugation is beneficial for improving quantum efficiency and charge transfer efficiency. Moreover, the acenaphthylenebenzofuran structure can increase the stability of the host material. In addition, the acenaphthylenebenzofuran structure also increases the planarity of the host material, which is beneficial for reducing the driving voltage of the organic electroluminescent device, effectively reducing energy loss, and contributing to the improvement of the efficiency and lifespan of the organic electroluminescent device.

[0199] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A blue luminescent compound containing an acenaphthylene structure, characterized in that: The general structural formula of the blue light-emitting compound is shown in Formula I: Wherein, L1 and L2 each independently represent a single bond, a substituted or unsubstituted arylene group having carbon atoms of C6 to C12; Ar represents any one of a substituted or unsubstituted aryl group having C6 to C60 carbon atoms, a substituted or unsubstituted heteroaryl group having C5 to C60 carbon atoms, a substituted or unsubstituted fused ring aryl group having C6 to C60 carbon atoms, and a substituted or unsubstituted heterofused ring aryl group having C5 to C60 carbon atoms; In Formula I, any hydrogen may be replaced by deuterium, any nitrogen may be replaced by nitrogen-15, any sulfur may be replaced by sulfur-33, sulfur-34 or sulfur-36, any oxygen may be replaced by oxygen-17 or oxygen-18, any carbon may be replaced by carbon-13, and any boron may be replaced by boron-11.

2. The blue luminescent compound according to claim 1, characterized in that The blue light-emitting compound is selected from one of the following structural formulas:

3. The blue luminescent compound according to claim 1, characterized in that The L1 and L2 each independently represent a single bond, a substituted or unsubstituted phenylene group or a naphthylene group.

4. The blue luminescent compound according to claim 1, characterized in that The L1 and L2 each independently represent a single bond, Any one of .

5. The blue light-emitting compound according to claim 1, characterized in that The Ar represents Any one of .

6. The blue light-emitting compound according to claim 1, characterized in that The Ar represents Any one of .

7. The blue light-emitting compound according to claim 1, characterized in that The blue light-emitting compound is selected from one of the following structures:

8. Use of the blue light-emitting compound according to any one of claims 1 to 7 in the preparation of an organic electroluminescent device.

9. An organic electroluminescent device, characterized in that: It includes an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode arranged in sequence on a substrate; wherein the light-emitting layer includes a host material and a guest material, and the host material includes one or more blue light-emitting compounds as described in any one of claims 1 to 7.

10. A display device, characterized in that The organic electroluminescent device according to claim 9 is included.

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