Organic compound containing isothiocyano group and organic electroluminescent device containing same

Abstract

The invention discloses an organic compound containing an isothiocyano group and an organic electroluminescent device containing the same. The structural general formula of the organic compound is as shown in one of formulas I to III. According to the invention, an isothiocyano group is introduced to a dehydrogenation fused ring mother nucleus, so that the compound has a deep LUMO energy level and a good electron withdrawing capability, the hole injection capability of the compound is maintained, and the compound also has high stability; when the organic compound is applied to the organic electroluminescent device as a P-type doping material, the driving voltage of the organic electroluminescent device can be effectively reduced, and the service life of the organic electroluminescent device is prolonged.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of OLED, and specifically comprises an organic compound containing isothiocyanide and an organic electroluminescent device comprising the same. BACKGROUND

[0002] An organic electroluminescent device uses a hole injection layer and an electron injection layer to facilitate charge injection. The hole injection layer is a functional layer formed by a single material or a plurality of materials. The single material is generally a material with a deep LUMO, while the plurality of materials is formed by doping a P-type, deep LUMO material into a hole transport material. The common point of the two is to use a deep LUMO material. However, deep LUMO materials are not easy to synthesize due to their strong electron-withdrawing substituents, and it is difficult to have deep LUMO, high stability and high film-forming properties at the same time.

[0003] Commonly used composite doping materials mostly use polyfluoro and polycyano chemical structures to reduce the LUMO energy level of the material, so that after doping with a hole transport material, the hole injection capacity is improved. However, with the deepening of research, it is found that fluorine atoms and cyano groups can significantly reduce the stability of the molecule, and also cause the reduction of the service life of the device.

[0004] Therefore, in view of the great influence of the hole injection layer on the driving voltage, efficiency and service life of the organic electroluminescent device, it is very important and urgent to develop a deep LUMO and high-stability doping material. SUMMARY

[0005] In view of the above problems existing in the prior art, the present application provides an organic compound containing an isothiocyanide group and an organic electroluminescent device comprising the same.

[0006] To achieve the above purpose, the technical solution adopted by the present application comprises:

[0007] The first aspect of the present application provides an organic compound containing an isothiocyanide group, and the structural general formula of the organic compound is shown in one of formula I to formula III:

[0008]

[0009] wherein,

[0010] Ar 11 , Ar 12 , Ar 21 , Ar 22 , Ar 31 , Ar 32 each independently selected from substituted or unsubstituted aryl with carbon atoms of 6 to 30;

[0011] L11 -L 14 L 21 -L 24 L 31 -L 34 Each independently represents a single bond, an aryl group with 6 to 30 carbon atoms, and L 11 -L 14 At least one of them represents an arylene group with 6 to 30 carbon atoms, L 21 -L 24 At least one of them represents an arylene group with 6 to 30 carbon atoms, L 31 -L 34 At least one of them represents an arylene group with 6 to 30 carbon atoms;

[0012] R 11 -R 14 R 21 -R 24 R 31 -R 34 Each of these independently represents hydrogen, -F, -CF3, -CN, -NCS, and -OCF3, and R 11 -R 14 At least one of them represents -NCS, R 21 -R 24 At least one of them represents -NCS, R 31 -R 34 At least one of them represents -NCS.

[0013] Furthermore, the general structural formula I of the organic compound is shown in one of formulas I-1 to I-2:

[0014]

[0015] Where m1, n1, p1, and q1 each independently represent 0, 1, 2, 3, 4, or 5, R 11 -R 14 Each can independently represent hydrogen, -F, -CF3, -CN, -NCS. When m1, n1, p1, q1 represent 2, 3, 4, or 5, R 11 -R 14 They can be the same or different.

[0016] Furthermore, the general structural formula II of the organic compound is shown in one of formulas II-1 to II-2:

[0017]

[0018] Where m2, n2, p2, and q2 each independently represent 0, 1, 2, 3, 4, or 5, R 21 -R 24each independently represents hydrogen, -F, -CF3, -CN, -NCS, R 21 -R 24 each independently represents hydrogen, -F, -CF3, -CN, -NCS, R

[0019] Further, the structural general formula III of the organic compound is shown as one of formula III-1 to formula III-2:

[0020]

[0021] each independently represents 0, 1, 2, 3, 4 or 5, R 31 -R 34 each independently represents hydrogen, -F, -CF3, -CN, -NCS, R 31 -R 34 each independently represents hydrogen, -F, -CF3, -CN, -NCS, R

[0022] Further, the aryl group is selected from phenyl, biphenyl.

[0023] Further, the substituent of the aryl group is selected from any one or combination of -F, -CF3, -CN, -OCF3.

[0024] Further, the organic compound is selected from one of the following structures:

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037] The second aspect of the present application provides an organic electroluminescent device, comprising an anode, a hole injection layer, a hole transport layer, an electron blocking layer, an emission layer, a hole blocking layer, an electron injection layer, a cathode, a cover layer arranged in sequence on a substrate; wherein the hole injection layer comprises one or more organic compounds as described above.

[0038] Further, the hole injection layer comprises a P-type doped material, wherein the P-type doped material is selected from one or more organic compounds as described above.

[0039] The present application has the following beneficial effects:

[0040] The present application provides an organic compound containing an isothiocyanate group and an organic electroluminescent device comprising the same. The structural general formula of the organic compound is shown in one of formula I to formula III. The present application introduces an isothiocyanate group on a dehydrogenated fused ring mother nucleus, which not only enables the compound to have a deeper LUMO energy level, better electron withdrawing ability, and maintain the hole injection ability of the compound, but also enables the compound to have higher stability. The organic compound is used as a P-type doped material in an organic electroluminescent device, which can effectively reduce the driving voltage of the organic electroluminescent device and prolong the service life of the organic electroluminescent device. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is a structural schematic diagram of the organic electroluminescent device of the present application. Wherein, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is an electron blocking layer, 6 is an emission layer, 7 is a hole blocking layer, 8 is an electron transport layer, 9 is an electron injection layer, 10 is a cathode, and 11 is a cover layer. DETAILED DESCRIPTION

[0042] In order to more clearly illustrate the present application, the present application will be further described below in conjunction with preferred embodiments and drawings. Those skilled in the art should understand that the specific description below is illustrative rather than limiting, and the protection scope of the present application should not be limited thereto. The examples and comparative examples of the present application are provided to more completely illustrate the present application to those skilled in the art, and the protection scope of the present application should not be limited to the following detailed examples and comparative examples.

[0043] The organic compounds of the present application are suitable for use in light-emitting elements, display panels, and electronic devices, and particularly suitable for use in organic electroluminescent devices. The electronic device of the present application is a device comprising a layer of at least one organic compound, which device can also comprise layers of inorganic materials or be formed entirely of inorganic materials. 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-quench device (O-FQD), a light-emitting electrochemical cell (LEC), an organic laser diode (O-laser), and an organic plasmonic emitter. The electronic device is preferably an organic electroluminescent device (OLED).

[0044] Experimental Section

[0045] In order to more clearly understand the present application, the organic compound, the method for preparing the organic compound, and the light-emitting properties of the device will be explained in detail with reference to examples. Various chemical reactions can be applied to the synthetic method of the compound of one embodiment of the present application. However, it should be noted that the synthetic method of the compound of one embodiment of the present application is not limited to the synthetic method described below. Unless otherwise specified, the following synthesis is performed in an anhydrous solvent under a protective gas atmosphere. Solvents and reagents can be purchased from conventional reagent suppliers.

[0046] Synthesis of A1-type intermediates: mother nucleus main part

[0047]

[0048] Synthesis of compounds b, c:

[0049] Into a 2000 mL three-necked flask was placed DMSO (1000 mL) under nitrogen atmosphere, and then triethyl orthoformate (222 g, 1.5 mol), ytterium triflate (21.5 g, 40 mmol) were added successively, followed by the addition of compound a (62.7 g, 300 mmol). The mixture was warmed to 60 °C and stirred overnight. After the completion of the reaction, DCM / PE (1:1, 2500 mL) was added to the mixture, and the solid was collected by filtration, washed with acetone, and then filtered to obtain compound b as a white solid (55.6 g, 81% yield). MS (m / z) (M+): 228.9

[0050] Compound b (55.6 g, 243 mmol) was added into 1000 ml of tetrahydrofuran, cooled to 78 °C, then added into the reactor slowly dropwise n-butyllithium (214 mL, 535 mmol, 2.5 M n-hexane solution), reacted for 8 hours at this temperature. Controlled the temperature at 78 °C, added into the reactor dropwise iodine (135.8 g, 535 mmol) in THF (150 mL) in batches, slowly increased to room temperature overnight after the addition was completed, quenched by adding a small amount of saturated aqueous ammonium chloride solution, the crude product after rotary evaporation was purified by silica gel column chromatography (PE:DCM = 3:1 1:1) to obtain white solid product, compound c (60.7 g, 52% yield). MS (m / z) (M+): 480.7

[0051] Synthesis of compound d:

[0052] Compound c (60.7 g, 126 mmol) and tetrakis triphenylphosphine palladium (12 g, 10 mmol) were added, and the temperature was increased to 90 °C for 24 hours of reaction. After complete conversion, pour into ice water, adjust to pH <1 using 2N dilute hydrochloric acid, after sufficient stirring, a large amount of yellow solid precipitated, filter, collect the solid. Wash with dichloromethane to obtain yellow solid. The yellow solid was recrystallized once with dichloromethane to obtain intermediate compound d (74.7 g, 80%) MS (m / z) (M+): 741.6

[0053] Synthesis of compound e, f

[0054] Into the solution of compound d (74.7 g, 101 mmol) in ethanol (500 mL), add Raney Ni (1.7 g), slowly pass hydrogen gas under stirring at room temperature until the hydrogen absorption is complete, continue to react for 12 hours. After the reaction is complete, the mixture is filtered through diatomite, collect the filtrate, remove the solvent by rotary evaporation to obtain yellow solid compound e (54.6 g, 87%) MS (m / z) (M+): 621.77

[0055] In a reaction flask, calcium carbonate (69.6 g, 696 mmol) was added, and a mixed solution of dichloromethane / water (3:1 by volume) was added 1000 ml, and cooled to 0°C, and thionyl chloride (80.0 g, 696 mmol) was added, and stirred for a few minutes, and a dichloromethane solution (400 ml) of compound e (54.6 g, 88 mmol) was added at 0°C to 5°C, and reacted at room temperature for 2 hours. The organic phase was separated, dried, and the solvent was removed, and the crude product was purified by column separation using n-heptane:toluene = 9:1, and finally compound f (38.9 g, 56%) was obtained. MS (m / z) (M+): 789.6

[0056] Synthesis of compound A1

[0057] Compound f (38.9 g, 49 mmol) was added to DCM (500 mL) under a nitrogen atmosphere, and cooled to 0°C, and di(trifluoroacetic acid)iodobenzene (63.2 g, 147 mmol) was added in portions, and stirred at room temperature for 48 hours. After that, n-hexane (2500 mL) was added to the reaction solution, and stirred for 30 minutes, and then filtered to obtain a dark green solid. This was washed twice using (DCM / PE = 1:1), and finally solid compound A1 (30.0 g, 77%) was obtained. MS (m / z) (M+): 787.6

[0058] Synthesis of intermediates in class A2: main body of the mother nucleus

[0059]

[0060] Synthesis of compound i

[0061] DMSO (1000 mL) was added to a 2000 mL three-necked flask, and protected with nitrogen, and triethyl orthoformate (222 g, 1.5 mol) was added, and ytterbium triflate (21.5 g, 40 mmol) was added, and then compound h (62.7 g, 300 mmol) was added, and warmed to 60°C and stirred overnight. After the reaction was completed, DCM / PE (1:1, 2500 mL) was added to it, and the solid was collected by filtration, and washed with acetone, and filtered to obtain a white solid compound i (55.6 g, 81% yield). MS (m / z) (M+): 228.9

[0062] Synthesis of compound j

[0063] Compound i (7 g, 30 mmol) was dissolved in anhydrous THF (350 mL) under nitrogen atmosphere, the system was cooled to -78 °C, and n-butyllithium (26.8 mL, 67 mmol, 2.5 M solution in n-hexane) was added dropwise slowly to the above solution with vigorous stirring. After the addition was completed, the stirring was continued for 30 min, and a solution of ZnCl2(16.6 g, 122 mmol) in ether (20 mL) was added. After the addition was completed, the reaction system was slowly warmed to 0 °C, and the stirring was continued for 45 min. CuI (11.6 mg, 61 mmol) was weighed and added to the reaction system, and after stirring for 10 min, a solution of p-nitrobenzoyl chloride (15 g, 61 mmol, 100) in anhydrous THF (10 mL) was added slowly in portions while maintaining the low temperature. The mixture was stirred in an ice bath for 45 min. After the reaction was completed, ethyl acetate (1500 mL) was added for dilution, and 10% ammonia water (1000 mL), H2O (1000 mL), and crude salt water (1000 mL) were used for washing in sequence. The organic phase was collected by liquid-liquid separation, dried over anhydrous sodium sulfate, and rotary evaporated to obtain a light brown solid. After being subjected to flash column chromatography (ethyl acetate: n-hexane = 1:20), the yellow solid compound j (8.7 g, 54%) was obtained by recrystallization in (EtOAc / hexane). MS (m / z) (M+): 525.97

[0064] Synthesis of compound k:

[0065] Hydroxylamine hydrochloride (2.2 g, 32 mmol) and sodium carbonate (3.4 g, 32 mmol) were dissolved in methanol (26 mL), and compound j (8.7 g, 16 mmol) was slowly added to the above solution at room temperature, and stirred for 12 hours. After the reaction was completed, the mixture was poured into 100 mL of cold water, and the organic phase was extracted by ether (60 mL x 3) for several times, and then combined, dried over anhydrous sodium sulfate, and rotary evaporated to remove the solvent. After being dried in an oven, the intermediate was dissolved in 40 mL of methanol, and nickel (118 g, 2 mmol) and sodium hydroxide aqueous solution (40 mL, 40 mmol) were added. Sodium borohydride (4.8 g, 128 mmol) in methanol (25 mL) was added dropwise to the above system at 20-30 °C within 2-4 hours, and after the addition was completed, the reaction was carried out at room temperature for 3 hours. After the reaction was completed, the mixture was filtered through diatomite, and the pH of the filtrate was adjusted to 9 using dilute hydrochloric acid. The organic phase was extracted by ether (80 mL x 3) for three times, and then combined, dried over anhydrous sodium sulfate, and rotary evaporated to remove the solvent. After being recrystallized three times in petroleum ether: dichloromethane = 1:2, compound k was obtained as a yellow solid (4 g, two-step yield 53%). MS (m / z) (M+): 468.09

[0066] Synthesis of compound A2:

[0067] Using the above method, compound A2 was obtained from compound k as starting material in 43% yield over two steps. MS (m / z) (M+): 635.6

[0068] Synthesis Example 1

[0069]

[0070] Compound Al (7.9 g, 10 mmol), pentafluorobenzene boronate pinacol ester Bl (5.5 g, 20 mmol), and potassium carbonate (4.2 g, 30 mmol) were added to a 100 ml mixture of toluene: water = 4: 1 (V / V) under nitrogen protection, then tetraphenylphosphonium palladium (1.2 g, 1 mmol) was added, and then the reaction system was heated to 110°C, refluxed and maintained for 8 hours. After cooling to room temperature, water was added to quench and separate, and the organic phase was dried with anhydrous sodium sulfate. The solvent was removed by rotary evaporation, and the crude product was recrystallized 3 times with petroleum ether: dichloromethane = 1:2. Finally, product Cl (4.8 g, 48%) was obtained, MS (m / z) (M+): 1006.1

[0071] Synthesis Example 2

[0072]

[0073] Using the same method as in synthesis example 1, compound A2 (6.3 g, 10 mmol), pentafluorobenzene boronate pinacol ester B2 (5.8 g, 20 mmol) were used as starting materials to obtain product C2 (6 g, 67%), MS (m / z) (M+): 897.9

[0074] Synthesis Example 3

[0075]

[0076] Using the same synthesis method as Al, A3 was prepared, and then using the same method as in synthesis example 1, the difference is that A3 (9.32 g; 10 mmol), B3 (1.9 g; 10 mmol) are used to replace Al and Bl, and finally product C3: 10.01 g (yield: 87%) is obtained, MS (m / z) (M+): 1150.

[0077] Synthesis Example 4

[0078]

[0079] A4 was prepared using the same synthetic method as A1, and then the same method as in Synthesis Example 1 was used, except that A4 (7.79 g; 10 mmol) and B4 (1.83 g; 10 mmol) were used to replace A1 and B1, finally yielding product C4: 8.07 g (yield: 82%), MS (m / z) (M+): 984.

[0080] Synthesis Example 5

[0081]

[0082] A5 was prepared using the same synthetic method as A1, and then the same method as in Synthesis Example 1 was used, except that A5 (10.76 g; 10 mmol) and B5 (2.84 g; 10 mmol) were used to replace A1 and B1, finally yielding product C5: 12.6 g (yield: 85%), MS (m / z) (M+): 1482.

[0083] Synthesis Example 6

[0084]

[0085] A6 was prepared using the same synthetic method as A1, and then the same method as in Synthesis Example 1 was used, except that A6 (7.79 g; 10 mmol) and B6 (2.91 g; 10 mmol) were used to replace A1 and B1, finally yielding product C6: 10.56 g (yield: 88%), MS (m / z) (M+): 1200.

[0086] Synthesis Example 7

[0087]

[0088] A7 was prepared using the same synthetic method as A2, and then A1 and B1 were replaced by A7 (7.79 g; 10 mmol) and B7 (2.91 g; 10 mmol) using the same method as in Synthesis Example 1, with the final product C7: 9.84 g (yield: 82%), MS (m / z) (M+): 1200.

[0089] Synthesis Example 8

[0090]

[0091] A8 was prepared using the same synthetic method as A2, and then A1 and B1 were replaced by A8 (10.76 g; 10 mmol) and B8 (3.2 g; 10 mmol) using the same method as in Synthesis Example 1, with the final product C8 being 12.43 g (yield: 80%), MS (m / z) (M+): 1554.

[0092] Synthesis Example 9

[0093]

[0094] A9 was prepared using the same synthetic method as A2, and then A1 and B1 were replaced by A9 (9.32 g; 10 mmol) and B9 (2.58 g; 10 mmol) using the same method as in Synthesis Example 1, with the final product C9 being 11.19 g (yield: 87%), MS (m / z) (M+): 1286.

[0095] Synthesis Example 10

[0096]

[0097] A10 was prepared using the same synthetic method as A1, and then the same method as in Synthesis Example 1 was used, except that A10 (7.88 g; 10 mmol) and B10 (2.12 g; 10 mmol) were used to replace A1 and B1, finally yielding product C10: 9.14 g (yield: 87%), MS (m / z) (M+): 1050.

[0098] Synthesis Example 11

[0099]

[0100] A11 was prepared using the same synthetic method as A1. Then, using the same method as in Synthesis Example 1, except that A11 (7.79 g; 10 mmol) and B11 (2.12 g; 10 mmol) were used to replace A1 and B1, finally yielding product C11: 8.65 g (yield: 83%), MS (m / z) (M+): 1042.

[0101] Synthesis Example 12

[0102]

[0103] A12 was prepared using the same synthetic method as A1, and then the same method as in Synthesis Example 1 was used, except that A12 (9.32 g; 10 mmol) and B12 (2.4 g; 10 mmol) were used to replace A1 and B1, finally yielding product C12: 12.04 g (yield: 90%), MS (m / z) (M+): 1338.

[0104] Synthesis Example 13

[0105]

[0106] A13 was prepared using the same synthetic method as A1, and then the same method as in Synthesis Example 1 was used, except that A13 (7.79 g; 10 mmol) and B13 (3.2 g; 10 mmol) were used to replace A1 and B1, finally yielding product C13: 10.82 g (yield: 86%), MS (m / z) (M+): 1258.

[0107] Comparative Examples 1-3

[0108]

[0109] Examples 1-13 and Comparative Examples 1-3: LUMO Levels

[0110] The HOMO level was measured using cyclic voltammetry, and the LUMO level was calculated from the HOMO level and Eg.

[0111] The HOMO level measurement method is as follows: Cyclic voltammetry is measured from a solution of organic molecules at a concentration of 10⁻³ mol / L in dichloromethane or a suitable solvent and a suitable supporting electrolyte (e.g., 0.1 mol / L tetrabutylammonium hexafluorophosphate). Measurements are performed at room temperature under a nitrogen atmosphere using a three-electrode assembly (working and counter electrodes: Pt wire, reference electrode: Pt wire) and calibrated using FeCp²⁺ / FeCp²⁺ as an internal standard. HOMO data are corrected relative to a saturated calomel electrode (SCE) using ferrocene as an internal standard.

[0112] Table 1 shows the energy level data of the compounds in the examples and comparative examples.

[0113] Table 1

[0114] Numbering LUMO level C1 5.16 C2 5.14 C3 5.17 C4 5.18 C5 5.17 C6 5.18 C7 5.12 C8 5.15 C9 5.13 C10 5.14 C11 5.16 C12 5.15 C13 5.16 D1 5.20 D2 5.25 D3 5.31

[0115] As can be seen from the LUMO energy level data in Table 1, the organic compounds containing isothiocyanate substituents provided by this invention have deeper LUMO energy levels compared to the comparative compounds.

[0116] Device Examples

[0117] The organic electroluminescent device provided by the present invention includes an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron injection layer, a cathode, and a capping layer sequentially disposed on a substrate.

[0118] Furthermore, the hole injection layer includes a P-type doped material, wherein the P-type doped material is selected from the above-mentioned organic compounds.

[0119] In this embodiment, the anode uses a commonly used anode material in the art, such as ITO, Ag, or their multilayer structures. The hole transport layer uses a commonly used hole transport material in the art. The light-emitting layer uses the host and guest material composition provided by this invention. The electron transport layer uses a commonly used electron transport material in the art. The electron injection layer uses a commonly used electron injection material in the art, such as LiQ, LiF, Yb, etc. The cathode uses a commonly used material in the art, such as metallic Al, Ag, or metal mixtures (Ag-doped Mg, Ag-doped Ca, etc.).

[0120] The electrode fabrication 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 fabrication process are supplemented as follows:

[0121] Device Example 1

[0122] The substrates used in this invention are subjected to the following operations: The ITO substrate is patterned to achieve a light-emitting area of ​​3mm × 3mm, then subjected to ultrasonic treatment with water / isopropanol, UV / ozone irradiation, and finally dried at 100°C. Afterwards, the ITO substrate is mounted on the substrate support of a vacuum deposition apparatus, and the pressure is adjusted to achieve a vacuum rate of 1 × 10⁻⁶. -7 torr.

[0123] The following operations are then performed: First, a hole injection layer is formed on the ITO layer (anode) formed on the substrate by vacuum deposition of compound C1 and compound HT-1 (mass ratio of compound C1 to compound HT-1 is 2:98) provided in Example 1 of the present invention with a thickness of 10 nm; second, a hole transport layer is formed on the hole injection layer by vacuum deposition of HT-1 with a thickness of 110 nm; third, an electron blocking layer is formed on the hole transport layer by vacuum deposition of compound EB-1 with a thickness of 10 nm; fourth, a light-emitting layer is formed on the electron blocking layer by vacuum deposition of a mixture of compound BD-1 and compound BH with a thickness of 20 nm (mass ratio of BD-1 to BH is 2:98); fifth, a hole blocking layer is formed on the light-emitting layer by vacuum deposition of compound HB-1 with a thickness of 5 nm; sixth, a hole blocking layer is formed on the hole blocking layer by vacuum deposition of compound HB-1 with a thickness of 5 nm; seventh, a hole transport layer is formed on the hole transport layer by vacuum deposition of compound EB-1 with a thickness of 110 nm; elution layer is formed on the hole transport layer by vacuum deposition of compound EB-1 with a thickness of 10 nm; elution layer is formed on the hole blocking layer by vacuum deposition of compound HB-1 with a thickness of 5 ... On the barrier layer, an electron transport layer is formed by vacuum depositing compounds ET-1 and Liq (ET-1 to Liq in a mass ratio of 1:1) with a thickness of 30 nm. Then, an electron injection layer is formed by depositing LiF with a thickness of 1 nm on the electron transport layer. Next, a cathode is formed by depositing Mg and Ag (Mg to Ag in a mass ratio of 1:9) with a thickness of 15 nm on the electron injection layer. Then, a cover layer is formed by depositing CPL1 with a thickness of 50 nm on the cathode. Finally, the substrate with vapor deposition is encapsulated. The cleaned cover plate is coated with UV adhesive using a coating equipment. The coated cover plate is then moved to the pressing section. The substrate with vapor deposition is placed on the top of the cover plate. Finally, the substrate and cover plate are bonded together under the action of a bonding equipment. At the same time, the UV adhesive is photocured to prepare an organic electroluminescent device.

[0124] The molecular structural formulas of the materials used in this invention and the materials in each layer of the device are as follows:

[0125]

[0126] Device Examples 2-13

[0127] Organic electroluminescent devices were prepared by using the above method with the compounds described in the examples, wherein C2 to C12 were used to replace C1 to prepare organic electroluminescent devices in Examples 2-13.

[0128] Device Comparison Examples 1-3

[0129] The preparation method is the same as in Device Example 1, except that compound C1 in the hole injection layer is replaced with compounds D1-D3, and the mass ratio of compounds D1-D3 to HT-1 in the hole injection layer is 2:98.

[0130] 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.

[0131] Device performance

[0132] The organic electroluminescent devices provided in Device Examples 1-12 and Device Comparative Examples 1-3 were tested using standard methods.

[0133] The OLED devices described above were tested using standard methods. For this purpose, J = 10 mA / cm² was used. 2 The driving voltage and luminous efficiency of the organic electroluminescent device were determined at a current density of J = 20 mA / cm². LT95 refers to the blue light emission of the fabricated device at this current density. 2 When the light output is not operating, the luminous intensity drops to 95% of its initial value L0 after a certain period of time.

[0134] The testing instruments and methods used to perform performance testing on the OLED devices of the above embodiments and comparative examples are as follows:

[0135] Luminous efficacy (CE) (cd / A) and chromaticity coordinates (CIEy) were measured using a PhotoResearch PR-655 spectral scanner.

[0136] Current density and turn-on voltage: tested using a Keithley 2400 digital source meter;

[0137] 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. BI (Blue index) is obtained by dividing the luminous efficiency CE (cd / A) by the chromaticity coordinate (CIEy).

[0138] Lifetime testing: Using a silicon photonics-based OLED device lifetime testing system.

[0139] The performance test results of the above devices are listed in Table 2.

[0140] Table 2 Device performance test results

[0141]

[0142] As can be seen from the test results in Tables 1 and 2 above, the organic compound containing isothiocyanate groups provided by the present invention, by introducing isothiocyanate groups on the dehydrogenated fused ring core, not only enables the compound to have a deeper LUMO energy level and better electron-withdrawing ability, and maintain the hole injection ability of the compound, but also enables the compound to have higher stability. When this organic compound is used as a p-type dopant in organic electroluminescent devices, it can effectively reduce the driving voltage of organic electroluminescent devices and extend the lifetime of organic electroluminescent devices.

[0143] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An organic compound containing an isothiocyanato group, characterized by, The structural general formula of the organic compound is shown as one of formula I to formula III: Among them, Ar 11 , Ar 12 , Ar 21 , Ar 22 , Ar 31 , Ar 32 each independently is selected from substituted or unsubstituted aryl having 6 to 30 carbon atoms; L 11 -L 14 , L 21 -L 24 , L 31 -L 34 each independently represents a single bond, an arylene group having 6 to 30 carbon atoms, and L 11 -L 14 at least one of L 21 -L 24 at least one of L 31 -L 34 at least one of L R 11 -R 14 , R 21 -R 24 , R 31 -R 34 each independently represents hydrogen, -F, -CF3, -CN, -NCS, -OCF3, and R 11 -R 14 at least one of which represents -NCS, R 21 -R 24 at least one of which represents -NCS, R 31 -R 34 at least one of which represents -NCS.

2. The organic compound according to claim 1, characterized by The structural general formula I of the organic compound is shown as one of formula I-1 to formula I-2: wherein m1, n1, p1, q1 each independently represent 0, 1, 2, 3, 4 or 5, R 11 -R 14 each independently represent hydrogen, -F, -CF3, -CN, -NCS, when m1, n1, p1, q1 represent 2, 3, 4 or 5, R 11 -R 14 may be the same or different.

3. The organic compound according to claim 1, wherein The structural general formula II of the organic compound is shown as one of formula II-1 to formula II-2: wherein m2, n2, p2, q2 each independently represent 0, 1, 2, 3, 4 or 5, R 21 -R 24 each independently represent hydrogen, -F, -CF3, -CN, -NCS, when m2, n2, p2, q2 represent 2, 3, 4 or 5, R 21 -R 24 may be the same or different.

4. The organic compound according to claim 1, wherein The structural general formula III of the organic compound is shown as one of formula III-1 to formula III-2: wherein m3, n3, p3, q3 each independently represent 0, 1, 2, 3, 4 or 5, R 31 -R 34 each independently represent hydrogen, -F, -CF3, -CN, -NCS, when m3, n3, p3, q3 represent 2, 3, 4 or 5, R 31 -R 34 may be the same or different.

5. The organic compound according to claim 1, wherein The aryl group is selected from phenyl, biphenyl.

6. The organic compound according to claim 1, wherein The substituent of the aryl group is selected from any one or combination of -F, -CF3, -CN, -OCF3.

7. The organic compound according to claim 1, wherein The organic compound is selected from one of the following structures:

8. An organic electroluminescent device, characterized by The organic compound is selected from one of the following structures:

9. The organic electroluminescent device according to claim 8, characterized in that The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected from one of the following structures: The organic compound is selected

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