An organic compound, a composition containing the same, and an organic electroluminescent device

Abstract

The application discloses an organic compound, a composition containing the same and an organic electroluminescent device. The structural general formula of the organic compound is shown as formula I. When the structure contains oxygen heteroatoms, the oxygen atoms contain two pairs of uninvolved lone pair electrons, thus having large electronegativity, easily generating good interaction with a doped material compound and having large polarity. When the composition is composed of the compound shown as formula II, the strong interaction between the two compounds can significantly improve the energy transmission between the two compounds. When the composition provided by the application is applied to a blue organic electroluminescent device as a light-emitting layer material, the host light-emitting phenomenon can be avoided, the light-emitting efficiency of the blue organic electroluminescent device is improved, the service life of the blue organic electroluminescent device is prolonged, and the defects of the prior art are overcome.

Description

Technical Field

[0001] This invention belongs to the field of OLED technology, and particularly relates to an organic compound, a composition containing the same, and an organic electroluminescent device. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are a display lighting technology that has gradually developed in recent years. Especially in the display industry, OLED displays have attracted widespread attention due to their advantages such as high response time, high contrast ratio, and flexibility. Currently, the pixel units of full-color OLED displays on the market are composed of red, green, and blue primary colors. According to the principle of the three primary colors, various colors can be generated by controlling the monochromatic gray levels of red, green, and blue in the sub-pixel units, thus displaying a color image. Among the three-color light-emitting devices, blue light materials have higher energy than red and green light materials. This energy can be transferred to lower-energy organic light-emitting materials such as green, yellow, and red light. Furthermore, according to the principle of the three primary colors, blue light emission is the foundation for achieving white and color displays. Therefore, blue light materials are a key research focus in the field of organic optoelectronic materials.

[0003] Currently, almost all blue organic light-emitting devices (OLEDs) use host-guest doped luminescent systems for their luminescent layers, achieving electroluminescence by doping a host material with a guest dopant. Existing blue fluorescent devices primarily use anthracene-based host materials, which have poor stability and typically employ fused-ring structures such as naphthalene as substituents. These structures exhibit good overall structural symmetry and low polarity, making it difficult to generate strong interactions with the dopant materials. The weaker the interaction between the host and dopant materials, the worse the energy transfer between them. When the deep blue light emitted by the host material cannot be absorbed by the dopant material, host emission occurs, emitting deep blue light in the 400-440 nm wavelength range. This light can damage the human eye and significantly reduce the efficiency of OLEDs. Furthermore, commonly used blue boron-nitrogen dopants, due to their planar core structure, often exhibit concentration quenching during film formation, severely impacting the efficiency and lifetime of OLEDs. Therefore, there is an urgent need to develop a new luminescent layer material for OLEDs. Summary of the Invention

[0004] In view of this, the present invention provides an organic compound, a composition comprising the same, and an organic electroluminescent device. The organic compound has high polarity and readily interacts well with dopant compounds; the strong interaction between the two compounds in the composition significantly improves energy transfer between them. When the composition provided by the present invention is used as a light-emitting layer material in a blue organic electroluminescent device, this light-emitting layer material can avoid bulk luminescence, improve the luminous efficiency of the blue organic electroluminescent device, extend its lifespan, and overcome the shortcomings of the prior art.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] The first aspect of this invention provides an organic compound, the general structural formula of which is shown in Formula I:

[0007]

[0008] X1 and X2 are independently selected from O, S or Se;

[0009] D is deuterium, and n is an integer from 0 to 8;

[0010] The L1 is selected from arylene groups with 6 to 30 carbon atoms that are single-bonded, substituted, or unsubstituted.

[0011] The Ar1 is selected from aryl groups with 6 to 60 carbon atoms, substituted or unsubstituted, and fused-ring aryl groups with 10 to 60 carbon atoms, substituted or unsubstituted.

[0012] When any one of L1 and Ar1 contains a substituent, the substituent of L1 and Ar1 may be one or more, and each may be independently selected from deuterium, aryl with 6 to 30 carbon atoms, and fused-ring aryl with 10 to 30 carbon atoms.

[0013] The first aspect of this invention provides an organic compound containing a naphthanoquinone five-membered heterocyclic benzoquinone structure, which has higher stability compared to the traditional anthracene structure. This structure is located on one side of the anthracene and forms an asymmetric structure with the fused ring on the other side. This structure contains oxo-heteroatoms, which have two pairs of lone pairs of electrons that do not participate in bonding, thus exhibiting high electronegativity. This results in a material with high polarity, which facilitates good interaction with doped material compounds.

[0014] In conjunction with the first aspect, the organic compound is selected from any one of the structures shown in Formula I-1 to Formula I-5:

[0015]

[0016] In conjunction with the first aspect, the organic compound is selected from any of the structures shown below:

[0017]

[0018]

[0019]

[0020] A second aspect of the present invention provides a composition comprising one or more organic compounds as shown in Formula I above and one or more compounds as shown in Formula II:

[0021]

[0022] R1, R2, R3, R4, R5, and R6 are each independently selected from any one or any combination of hydrogen, deuterium, alkyl groups with 1 to 10 carbon atoms (substituted or unsubstituted), cycloalkyl groups with 3 to 30 carbon atoms (substituted or unsubstituted), and aryl groups with 6 to 30 carbon atoms (substituted or unsubstituted). R1 ​​and R2 independently represent monosubstituted to the maximum permissible substituent, wherein multiple R1 or R2 can be bonded to each other by linking groups or single bonds to form aliphatic rings, aromatic rings, or fused rings.

[0023] The Ar2 is selected from any one of aryl groups with 6 to 60 carbon atoms, substituted or unsubstituted, and fused-ring aryl groups with 10 to 60 carbon atoms, substituted or unsubstituted.

[0024] When any one of R1 to R6 and Ar2 contains a substituent, the substituent of R1 to R6 and Ar2 may be one or more, and may be independently selected from any one of deuterium, alkyl with 1 to 10 carbon atoms, and cycloalkyl with 3 to 30 carbon atoms. Two or more substituents may be bonded to each other by a linking group or a single bond to form an aliphatic ring, an aromatic ring, or a fused ring.

[0025] A second aspect of the present invention provides a composition in which a host material compound and a dopant material compound have a strong interaction. The dopant material compound provided by the present invention contains a benzothiophene fragment and a cycloalkyl fragment. Through the interaction between the benzothiophene fragment and the cycloalkyl fragment, the dopant material compound has a suitable polarity, which avoids both excessively low polarity resulting in insufficient host force and excessively high polarity leading to increased intermolecular aggregation of dopant material and concentration quenching. The present invention, through the reasonable combination of the host material compound and the dopant material compound, achieves a strong interaction between the host material compound and the dopant material compound, which can significantly improve the energy transfer between the two.

[0026] In conjunction with the second aspect, R3 is a cycloalkyl group having 5 to 10 carbon atoms, either substituted or unsubstituted.

[0027] In conjunction with the second aspect, R4 and R5 are selected from any one of hydrogen, alkyl groups having 1 to 5 carbon atoms (substituted or unsubstituted), and cycloalkyl groups having 3 to 10 carbon atoms (substituted or unsubstituted).

[0028] In conjunction with the second aspect, the compound represented by Formula II is selected from any one of the structures represented by Formula II-1 to Formula II-4 below:

[0029]

[0030]

[0031] In conjunction with the second aspect, the compound represented by Formula II is selected from any one of the following compounds:

[0032]

[0033]

[0034]

[0035]

[0036] A third aspect of the present invention provides an organic electroluminescent device, comprising a first electrode disposed sequentially on a substrate; a second electrode disposed opposite to the first electrode; and one or more organic functional layers disposed between the first electrode and the second electrode;

[0037] The organic functional layer includes a light-emitting layer; the light-emitting layer includes the composition described in the second aspect.

[0038] In conjunction with the third aspect, the light-emitting layer comprises a host material and a dopant material, wherein the host material comprises one or more compounds represented by chemical formula I; and the dopant material comprises one or more compounds represented by chemical formula II.

[0039] The beneficial effects of this invention are as follows:

[0040] The first aspect of this invention provides an organic compound containing a naphthanoquinone five-membered heterocyclic benzoquinone structure, which has higher stability compared to the traditional anthracene structure. This structure is located on one side of the anthracene and forms an asymmetric structure with the fused ring on the other side. This structure contains oxo-group heteroatoms, which have two pairs of lone pairs of electrons that do not participate in bonding, thus exhibiting high electronegativity. This results in a material with high polarity, which facilitates good interaction with doped material compounds.

[0041] A second aspect of the present invention provides a composition in which a host material compound and a dopant material compound have a strong interaction. The dopant material compound provided by the present invention contains a benzothiophene fragment and a cycloalkyl fragment. Through the interaction between the benzothiophene fragment and the cycloalkyl fragment, the dopant material compound has a suitable polarity, which avoids both excessively low polarity resulting in insufficient host force and excessively high polarity leading to increased intermolecular aggregation of dopant material and concentration quenching. The present invention, through the reasonable combination of the host material compound and the dopant material compound, achieves a strong interaction between the host material compound and the dopant material compound, which can significantly improve the energy transfer between the two.

[0042] A third aspect of this invention provides an organic electroluminescent device, in which a compound of Formula I is used as a first host compound and a compound of Formula II is used as a dopant in the light-emitting layer of the organic electroluminescent device. The host compound and the dopant compound provided by this invention have a strong interaction. When the concentration of the dopant compound is reduced, i.e., the mass ratio of the host compound to the dopant compound is adjusted from 98:2 to 99:1, the organic electroluminescent device using the host compound and the dopant compound as the light-emitting layer of this invention does not exhibit host emission, and the efficiency of the organic electroluminescent device is significantly improved. This indicates that there is a strong interaction between the host compound and the dopant compound in the composition provided by this invention, which can significantly improve the energy transfer between them, thereby effectively improving the efficiency of the organic electroluminescent device and extending its lifespan, overcoming the shortcomings of the prior art. Attached Figure Description

[0043] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0044] Figure 1 A schematic diagram of the structure of an organic electroluminescent device containing the organic compounds and compositions of the present invention;

[0045] Figure 2 The electroluminescence spectrum of experimental device 86 exhibiting host emission phenomenon;

[0046] Figure 3 The electroluminescence spectrum of experimental device 1 without host emission is shown.

[0047] Figure description: 1-substrate, 2-anode, 3-hole injection layer, 4-hole transport layer, 5-light-emitting auxiliary layer, 6-light-emitting layer, 7-electron transport layer, 8-electron injection layer, 9-cathode. Detailed Implementation

[0048] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further clarifies the invention. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention. The embodiments and comparative examples in this specification are provided to provide a more complete explanation of the specification to those skilled in the art. Various modifications can be made based on the embodiments and comparative examples in this specification, and the scope of protection of the present invention should not be limited to the embodiments and comparative examples detailed below.

[0049] The organic compounds and compositions of the present invention are suitable for use in light-emitting elements, display panels, and electronic devices, particularly organic electroluminescent devices. The electronic devices of the present invention are devices comprising a layer of at least one organic compound, and may also comprise layers of inorganic materials or layers formed entirely of inorganic materials. Preferred electronic devices include organic electroluminescent devices (OLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic dye-sensitized solar cells (O-DSSCs), organic optical detectors, organic photosensors, organic field quenching devices (O-FQDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-lasers), and organic plasma emitting devices. Organic electroluminescent devices (OLEDs) are particularly preferred.

[0050] To better understand the content of this invention, the organic compound, the preparation method of the compound, and the luminescent properties of the device will be explained in detail with reference to embodiments. Various chemical reactions can be applied to the synthesis method of the compound according to one embodiment of this invention. However, it should be noted that the synthesis method of the compound according to one embodiment of this invention is not limited to the synthesis 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.

[0051] Intermediate synthesis of host material compounds

[0052]

[0053] At room temperature, A (14.40 g, 0.1 mol) was dissolved in 250 mL of tetrahydrofuran solvent. Then, 50 mL of potassium hydroxide solution (10 mol / L) was added dropwise to the system, and the mixture was stirred for 1 hour. Subsequently, dimethyl sulfate (19.4 mL, 0.2 mol) was added dropwise to the system, and the mixture was stirred at 25 °C for 8 hours. After the reaction was completed, the mixture was filtered to obtain the filtrate. The filtrate was concentrated and purified by recrystallization from toluene and ethanol in a volume ratio of 1:1 to obtain B: 13.43 g, yield 85%, MS (m / z) (M+): 158.

[0054] Under a nitrogen atmosphere and at -80°C, a cyclohexane solution of sec-butyllithium (180 mL, 1 mol / L) and tetramethylethylenediamine (20.88 g, 0.18 mol) were added to 270 mL of dry tetrahydrofuran and stirred for 15 minutes to obtain reaction system A. B (9.48 g, 60 mmol) was dissolved in 120 mL of dry tetrahydrofuran to obtain a tetrahydrofuran solution of B. This tetrahydrofuran solution of B was slowly added to reaction system A, and the reaction was carried out at 0°C for 1 hour to obtain reaction system B. Trimethyl borate (9.36 g, 90 mmol) was dissolved in 120 mL of tetrahydrofuran to obtain a trimethyl borate tetrahydrofuran solution. This trimethyl borate tetrahydrofuran solution was slowly added dropwise to reaction system B over 2 hours at -80°C. The system was then slowly heated to 0°C and stirred at 0°C for 1 hour to obtain reaction system C. 15 mL of acetic acid and 35 mL of hydrogen peroxide aqueous solution (mass percentage concentration of 30%) were added to reaction system C, and the mixture was reacted at room temperature for 16 hours. After the reaction was completed, the reaction was quenched with 150 mL of water, filtered, and separated. The organic layer was washed with potassium hydroxide solution (mass percentage concentration of 5%) until the pH of the organic layer was adjusted to 6. The mixture was dried with anhydrous magnesium sulfate and concentrated under reduced pressure to obtain C: 8.35 g, yield 80%, MS (m / z) (M+): 174.

[0055] C (17.40 g, 0.1 mol), D (21.19 g, 0.13 mol), potassium carbonate (69 g, 0.5 mol), and 600 mL of ethanol were added to a 2 L flask and reacted at 80 °C for 24 hours. After the reaction was completed, the mixture was filtered, and the solvent was evaporated to obtain a solid. The solid was purified by recrystallization using dichloromethane and ethanol in a volume ratio of 1:1 to obtain E: 17.28 g, yield 60%, MS (m / z) (M+): 288.

[0056] E (13.4 g, 0.04 mol) was dissolved in 400 mL of dichloromethane to obtain a dichloromethane solution of E. Boron tribromide (10.04 g, 0.04 mol) was added dropwise to the dichloromethane solution of E at -20 °C. After stirring for 4 hours, the reaction was terminated by adding saturated sodium carbonate solution. The mixture was extracted with dichloromethane, separated, and the organic phase was obtained. The organic phase was concentrated and purified by recrystallization with dichloromethane and ethanol in a volume ratio of 1:1 to obtain F: 9.86 g, yield 90%, MS (m / z) (M+): 274.

[0057] F (9.86 g, 0.036 mol) and triethylamine (3.58 g, 0.035 mol) were dissolved in 360 mL of anhydrous dichloromethane under a nitrogen atmosphere to obtain system D. Trifluoromethanesulfonic anhydride (5.92 g, 0.021 mol) was added dropwise to system D at -20 °C, and the mixture was stirred for 2 hours. The mixture was washed with saturated sodium chloride solution, and then extracted with dichloromethane to obtain the organic phase. The organic phase was concentrated and purified by column chromatography to obtain G: 10.96 g, yield 75%, MS (m / z) (M+): 406.

[0058] Under a nitrogen atmosphere, 200 mL of toluene, 100 mL of water, and 50 mL of ethanol were added to a 500 mL flask and mixed to obtain system E1. G (8.12 g, 0.02 mol), H (8.48 g, 0.025 mol), potassium carbonate (2.76 g, 0.02 mol), and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride (0.07 g, 0.1 mmol) were added to system E1, and the mixture was reacted at 80 °C for 12 hours to obtain system F1. System F1 was concentrated and purified by column chromatography to obtain O: 8.44 g, yield 90%, MS (m / z) (M+): 469.

[0059] In a nitrogen atmosphere, [Cu(Cy2Im)(Cl)] (0.17 g, 0.05 mmol) was added to methylcyclohexane (30 mL) to obtain reaction system E2. Potassium tert-butoxide (0.84 g, 7.5 mmol), pinacol diborate (1.91 g, 7.5 mmol), and O (2.35 g, 5 mmol) were added to system E2. The mixture was stirred at 90 °C for 24 hours, diluted with diethyl ether (20 mL), filtered, and the solvent was removed from the filtrate to obtain the crude product. The crude product was separated by column chromatography (n-hexane / ethyl acetate = 95 / 5, v / v) to obtain the separated product. The solvent was removed from the separated product to obtain J-1: 2.1 g, yield 75%, MS (m / z) (M+): 560.

[0060] After obtaining J-1 through the above process, other host material compound intermediates can be prepared using a method similar to that of J-1.

[0061] Examples of synthesis of host material compounds

[0062] Example 1

[0063] This embodiment provides a host material compound L-1, the synthetic route of which is as follows:

[0064]

[0065] J-1 (5.60 g, 10 mmol) and K-1 (1.72 g, 10 mmol) were added to a mixture of toluene, ethanol, and water (volumes of toluene, ethanol, and water were 80 mL, 20 mL, and 20 mL, respectively). Under nitrogen protection, potassium carbonate (1.65 g, 10 mmol) and 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride (73 mg, 0.1 mmol) were added to the system. The reaction system was heated to reflux and maintained for 8 hours. After cooling to room temperature, the reaction was quenched with ice water and separated. The organic phase was filtered and dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to finally obtain product L-1: 4.21 g (yield: 77%), MS (m / z) (M+): 516.

[0066] Example 2

[0067] This embodiment provides a host material compound L-2, the synthetic route of which is as follows:

[0068]

[0069] Using the same method as in Example 1, except that equimolar amounts of J-2 (5.6 g, 10 mmol) and K-2 (2.07 g, 10 mmol) were used to replace J-1 and K-1, the final product L-2 was obtained: 4.32 g (yield: 77%), MS (m / z) (M+): 561.

[0070] Example 3

[0071] This embodiment provides a host material compound L-3, the synthetic route of which is as follows:

[0072]

[0073] Using the same method as in Example 1, except that equimolar amounts of J-3 (5.6 g, 10 mmol) and K-3 (2.83 g, 10 mmol) were used to replace J-1 and K-1, the final product L-3 was obtained: 4.9 g (yield: 77%), MS (m / z) (M+): 637.

[0074] Example 4

[0075] This embodiment provides a host material compound L-4, the synthetic route of which is as follows:

[0076]

[0077] Using the same method as in Example 1, except that equimolar amounts of J-4 (5.6 g; 10 mmol) and K-4 (2.07 g; 10 mmol) were used to replace J-1 and K-1, the final product L-4 was obtained: 4.43 g (yield: 79%), MS (m / z) (M+): 561.

[0078] Example 5

[0079] This embodiment provides a host material compound L-5, the synthetic route of which is as follows:

[0080]

[0081] Using the same method as in Example 1, except that equimolar amounts of J-5 (5.6 g; 10 mmol) and K-5 (2.83 g; 10 mmol) were used to replace J-1 and K-1, the final product L-5 was obtained: 4.46 g (yield: 70%), MS (m / z) (M+): 637.

[0082] Example 6

[0083] This embodiment provides a host material compound L-6, the synthetic route of which is as follows:

[0084]

[0085] Using the same method as in Example 1, except that equimolar amounts of J-6 (5.6 g; 10 mmol) and K-6 (2.83 g; 10 mmol) were used to replace J-1 and K-1, the final product L-6 was obtained: 4.27 g (yield: 67%), MS (m / z) (M+): 637.

[0086] Example 7

[0087] This embodiment provides a host material compound L-7, and the synthetic route of this compound is as follows:

[0088]

[0089] Using the same method as in Example 1, except that equimolar amounts of J-7 (5.6 g; 10 mmol) and K-7 (2.83 g; 10 mmol) were used to replace J-1 and K-1, the final product L-7 was obtained: 4.65 g (yield: 73%), MS (m / z) (M+): 637.

[0090] Example 8

[0091] This embodiment provides a host material compound L-8, the synthetic route of which is as follows:

[0092]

[0093] Using the same method as in Example 1, except that equimolar amounts of J-8 (5.6 g; 10 mmol) and K-8 (3.09 g; 10 mmol) were used to replace J-1 and K-1, the final product L-8 was 4.71 g (yield: 71%), MS (m / z) (M+): 663.

[0094] Example 9

[0095] This embodiment provides a host material compound L-9, the synthetic route of which is as follows:

[0096]

[0097] Using the same method as in Example 1, except that equimolar amounts of J-9 (5.69 g; 10 mmol) and K-9 (2.33 g; 10 mmol) were used to replace J-1 and K-1, the final product L-9 was obtained: 4.58 g (yield: 77%), MS (m / z) (M+): 595.

[0098] Example 10

[0099] This embodiment provides a host material compound L-10, the synthetic route of which is as follows:

[0100]

[0101] Using the same method as in Example 1, except that equimolar amounts of J-10 (5.6 g; 10 mmol) and K-10 (2.66 g; 10 mmol) were used to replace J-1 and K-1, the final product L-10 was obtained: 4.03 g (yield: 65%), MS (m / z) (M+): 620.

[0102] Example 11

[0103] This embodiment provides a host material compound L-11, the synthetic route of which is as follows:

[0104]

[0105] Using the same method as in Example 1, except that equimolar amounts of J-11 (5.77 g; 10 mmol) and K-11 (1.57 g; 10 mmol) were used to replace J-1 and K-1, the final product L-11 was 3.79 g (yield: 72%), MS (m / z) (M+): 527.

[0106] Example 12

[0107] This embodiment provides a host material compound L-12, the synthetic route of which is as follows:

[0108]

[0109] Using the same method as in Example 1, except that equimolar amounts of J-12 (5.77 g; 10 mmol) and K-12 (2.07 g; 10 mmol) were used to replace J-1 and K-1, the final product L-12 was obtained: 4.5 g (yield: 78%), MS (m / z) (M+): 577.

[0110] Example 13

[0111] This embodiment provides a host material compound L-13, the synthetic route of which is as follows:

[0112]

[0113] Using the same method as in Example 1, except that equimolar amounts of J-13 (5.77 g; 10 mmol) and K-13 (2.83 g; 10 mmol) were used to replace J-1 and K-1, the final product L-13 was obtained: 4.9 g (yield: 75%), MS (m / z) (M+): 653.

[0114] Example 14

[0115] This embodiment provides a host material compound L-14, the synthetic route of which is as follows:

[0116]

[0117] Using the same method as in Example 1, except that equimolar amounts of J-14 (5.85 g; 10 mmol) and K-14 (2.07 g; 10 mmol) were used to replace J-1 and K-1, the final product L-14 was obtained: 4.1 g (yield: 70%), MS (m / z) (M+): 585.

[0118] Example 15

[0119] This embodiment provides a host material compound L-15, and the synthetic route of this compound is as follows:

[0120]

[0121] Using the same method as in Example 1, except that equimolar amounts of J-15 (5.77 g; 10 mmol) and K-15 (2.83 g; 10 mmol) were used to replace J-1 and K-1, the final product L-15 was obtained: 4.9 g (yield: 75%), MS (m / z) (M+): 653.

[0122] Example 16

[0123] This embodiment provides a host material compound L-16, the synthetic route of which is as follows:

[0124]

[0125] Using the same method as in Example 1, except that equimolar amounts of J-16 (5.77 g; 10 mmol) and K-16 (2.83 g; 10 mmol) were used to replace J-1 and K-1, the final product L-16 was 4.9 g (yield: 75%), MS (m / z) (M+): 653.

[0126] Example 17

[0127] This embodiment provides a host material compound L-17, the synthetic route of which is as follows:

[0128]

[0129] Using the same method as in Example 1, except that equimolar amounts of J-17 (5.77 g; 10 mmol) and K-17 (2.87 g; 10 mmol) were used to replace J-1 and K-1, the final product L-17 was obtained: 4.99 g (yield: 76%), MS (m / z) (M+): 657.

[0130] Example 18

[0131] This embodiment provides a host material compound L-18, the synthetic route of which is as follows:

[0132]

[0133] Using the same method as in Example 1, except that equimolar amounts of J-18 (5.77 g; 10 mmol) and K-18 (3.09 g; 10 mmol) were used to replace J-1 and K-1, the final product L-18 was 4.75 g (yield: 70%), MS (m / z) (M+): 679.

[0134] Example 19

[0135] This embodiment provides a host material compound L-19, and the synthetic route of this compound is as follows:

[0136]

[0137] Using the same method as in Example 1, except that equimolar amounts of J-19 (5.77 g; 10 mmol) and K-19 (2.37 g; 10 mmol) were used to replace J-1 and K-1, the final product L-19 was 4.61 g (yield: 76%), MS (m / z) (M+): 607.

[0138] Example 20

[0139] This embodiment provides a host material compound L-20, the synthetic route of which is as follows:

[0140]

[0141] Using the same method as in Example 1, except that equimolar amounts of J-20 (5.77 g; 10 mmol) and K-20 (2.57 g; 10 mmol) were used to replace J-1 and K-1, the final product L-20 was obtained: 4.33 g (yield: 69%), MS (m / z) (M+): 627.

[0142] Intermediate synthesis of doped material compounds

[0143]

[0144]

[0145] M (2.54 g, 10 mmol) and N (2.34 g, 10 mmol) were added to a mixture of toluene, ethanol, and water (volumes of toluene, ethanol, and water were 80 mL, 20 mL, and 20 mL, respectively). Then, under nitrogen protection, potassium carbonate (1.65 g, 10 mmol) and 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride (73 mg, 0.1 mmol) were added to the system to obtain reaction system H. The reaction system H was then heated to reflux and maintained for 8 hours. After cooling to room temperature, the reaction was quenched with ice water and separated to obtain the organic phase. The organic phase was filtered and dried with anhydrous magnesium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to finally obtain product P: 3.09 g (yield: 85%), MS (m / z) (M+): 364.

[0146] Q (6.2 g, 0.025 mol), P (8.37 g, 0.023 mol), and sodium tert-butoxide (2.64 g, 0.03 mol) were added to toluene (200 mL). Under nitrogen protection, bis(dibenzylacetone)palladium (0.23 g, 0.25 mmol) and 2-biscyclohexylphosphine-2',6'-dimethoxy-1,1'-diphenyl (0.21 g, 0.5 mmol) were introduced to obtain reaction system J. Reaction system J was heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the reaction was quenched with water and separated to obtain the organic phase. The organic phase was filtered and dried with anhydrous sodium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to obtain product S: 9.14 g, yield: 75%, MS (m / z) (M+): 530.

[0147] T (6.73 g, 0.025 mol), S (12.19 g, 0.023 mol), and sodium tert-butoxide (2.64 g, 0.03 mol) were added to toluene (200 mL). Under nitrogen protection, bis(dibenzylacetone)palladium (0.23 g, 0.25 mmol) and 2-biscyclohexylphosphine-2',6'-dimethoxy-1,1'-diphenyl (0.21 g, 0.5 mmol) were introduced to obtain reaction system K. Reaction system K was heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the reaction was quenched with water and separated to obtain the organic phase. The organic phase was filtered and dried with anhydrous sodium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to obtain product U: 11.25 g, yield: 68%, MS (m / z) (M+): 719.

[0148] U (35.95 g, 0.05 mol), V (12.56 g, 0.045 mol), and sodium tert-butoxide (5.28 g, 0.055 mol) were added to toluene (200 mL). Under nitrogen protection, bis(dibenzylacetone)palladium (0.46 g, 0.50 mmol) and tri-tert-butylphosphine (0.26 g, 1 mmol) were introduced to obtain reaction system L. Reaction system L was heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the reaction was quenched with water and separated to obtain the organic phase. The organic phase was filtered and dried with anhydrous sodium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to obtain product W: 30.27 g, yield: 70%, MS (m / z) (M+): 961.

[0149] X (9.83 g, 0.025 mol), W (22.10 g, 0.023 mol), and sodium tert-butoxide (2.64 g, 0.03 mol) were added to toluene (200 mL). Under nitrogen protection, bis(dibenzylacetone)palladium (0.23 g, 0.25 mmol) and 2-biscyclohexylphosphine-2',6'-dimethoxy-1,1'-diphenyl (0.21 g, 0.5 mmol) were introduced to obtain reaction system M. Reaction system M was heated to 110 °C, refluxed, and maintained for 8 hours. After cooling to room temperature, the reaction was quenched with water and separated to obtain the organic phase. The organic phase was filtered and dried with anhydrous sodium sulfate. The solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to obtain product Y-1: 18.34 g, yield: 65%, MS (m / z) (M+): 1227.

[0150] After obtaining Y-1 through the above process, other doped material compound intermediates can be prepared using a method similar to that of Y-1.

[0151] Example 21

[0152] This embodiment provides a doped material compound Z-1, and the synthesis route of this compound is as follows:

[0153]

[0154] Y-1 (12.27 g; 10 mmol) was added to tert-butylbenzene (125 ml), and the mixture was cooled to 0 °C under nitrogen protection. 12.4 ml (21 mmol) of 1.7 M tert-butyllithium pentane solution was added, and the mixture was heated to 60 °C and stirred for 2 hours. The mixture was then cooled to 0 °C, and 2.0 ml (21 mmol) of boron tribromide was added and stirred for 0.5 h. The mixture was then cooled to 0 °C again, and 3.65 ml (21 mmol) of N,N-diisopropylethylamine was added. The mixture was heated to 60 °C and stirred for 2 h. After cooling to room temperature, the reaction was quenched with ice water, and the mixture was separated to obtain the organic phase. The organic phase was filtered and dehydrated with anhydrous magnesium sulfate. After removing the organic solvent by rotary evaporation, the crude product was obtained. The crude product was purified by recrystallization from dichloromethane and n-heptane in a volume ratio of 1:1 to finally obtain product Z-1: 1.16 g (yield: 10%), MS (m / z) (M+): 1156.

[0155] Example 22

[0156] This embodiment provides a doped material compound Z-2, and the synthesis route of this compound is as follows:

[0157]

[0158] Using the same method as in Example 21, except that an equimolar amount of Y-2 (12.49 g; 10 mmol) was used to replace Y-1, the final product Z-2 was obtained: 1.41 g (yield: 12%), MS (m / z) (M+): 1178.

[0159] Example 23

[0160] This embodiment provides a doped material compound Z-3, and the synthesis route of this compound is as follows:

[0161]

[0162] Using the same method as in Example 21, except that an equimolar amount of Y-3 (11.63 g; 10 mmol) was used to replace Y-1, the final product Z-3 was obtained: 1.20 g (yield: 11%), MS (m / z) (M+): 1091.

[0163] Example 24

[0164] This embodiment provides a doped material compound Z-4, and the synthesis route of this compound is as follows:

[0165]

[0166] Using the same method as in Example 21, except that an equimolar amount of Y-4 (11.99 g; 10 mmol) was used to replace Y-1, the final product Z-4 was obtained: 1.02 g (yield: 9%), MS (m / z) (M+): 1128.

[0167] Example 25

[0168] This embodiment provides a doped material compound Z-5, and the synthesis route of this compound is as follows:

[0169]

[0170] Using the same method as in Example 21, except that an equimolar amount of Y-5 (12.73 g; 10 mmol) was used to replace Y-1, the final product Z-5 was obtained: 0.96 g (yield: 8%), MS (m / z) (M+): 1203.

[0171] Example 26

[0172] This embodiment provides a doped material compound Z-6, and the synthesis route of this compound is as follows:

[0173]

[0174] Using the same method as in Example 21, except that an equimolar amount of Y-6 (11.06 g; 10 mmol) was used to replace Y-1, the final product Z-6 was obtained: 1.24 g (yield: 12%), MS (m / z) (M+): 1035.

[0175] Example 27

[0176] This embodiment provides a doped material compound Z-7, and the synthesis route of this compound is as follows:

[0177]

[0178] Using the same method as in Example 21, except that an equimolar amount of Y-7 (11.51 g; 10 mmol) was used to replace Y-1, the final product Z-7 was obtained: 1.29 g (yield: 12%), MS (m / z) (M+): 1079.

[0179] Example 28

[0180] This embodiment provides a doped material compound Z-8, and the synthesis route of this compound is as follows:

[0181]

[0182] Using the same method as in Example 21, except that an equimolar amount of Y-8 (11.45 g; 10 mmol) was used to replace Y-1, the final product Z-8 was 1.50 g (yield: 14%), MS (m / z) (M+): 1073.

[0183] Example 29

[0184] This embodiment provides a doped material compound Z-9, and the synthesis route of this compound is as follows:

[0185]

[0186] Using the same method as in Example 21, except that an equimolar amount of Y-9 (11.71 g; 10 mmol) was used to replace Y-1, the final product Z-9 was 1.1 g (yield: 10%), MS (m / z) (M+): 1099.

[0187] Example 30

[0188] This embodiment provides a doped material compound Z-10, and the synthesis route of this compound is as follows:

[0189]

[0190] Using the same method as in Example 21, except that an equimolar amount of Y-10 (11.23 g; 10 mmol) was used to replace Y-1, the final product Z-10 was obtained: 0.95 g (yield: 9%), MS (m / z) (M+): 1051.

[0191] Example 31

[0192] This embodiment provides a doped material compound Z-11, and the synthesis route of this compound is as follows:

[0193]

[0194] Using the same method as in Example 21, except that an equimolar amount of Y-11 (11.16 g; 10 mmol) was used to replace Y-1, the final product Z-11 was 1.05 g (yield: 10%), MS (m / z) (M+): 1045.

[0195] Example 32

[0196] This embodiment provides a doped material compound Z-12, and the synthesis route of this compound is as follows:

[0197]

[0198] Using the same method as in Example 21, except that an equimolar amount of Y-12 (11.43 g; 10 mmol) was used to replace Y-1, the final product Z-12 was 0.96 g (yield: 9%), MS (m / z) (M+): 1071.

[0199] Example 33

[0200] This embodiment provides a doped material compound Z-13, and the synthesis route of this compound is as follows:

[0201]

[0202] Using the same method as in Example 21, except that an equimolar amount of Y-13 (12.57 g; 10 mmol) was used to replace Y-1, the final product Z-13 was 1.54 g (yield: 13%), MS (m / z) (M+): 1187.

[0203] Example 34

[0204] This embodiment provides a doped material compound Z-14, and the synthesis route of this compound is as follows:

[0205]

[0206] Using the same method as in Example 21, except that an equimolar amount of Y-14 (12.49 g; 10 mmol) was used to replace Y-1, the final product Z-14 was 1.06 g (yield: 9%), MS (m / z) (M+): 1178.

[0207] Example 35

[0208] This embodiment provides a doped material compound Z-15, and the synthesis route of this compound is as follows:

[0209]

[0210] Using the same method as in Example 21, except that an equimolar amount of Y-15 (11.77 g; 10 mmol) was used to replace Y-1, the final product Z-15 was obtained: 1 g (yield: 9%), MS (m / z) (M+): 1106.

[0211] Example 36

[0212] This embodiment provides a doped material compound Z-16, and the synthetic route of this compound is as follows:

[0213]

[0214] Using the same method as in Example 21, except that an equimolar amount of Y-16 (12.13 g; 10 mmol) was used to replace Y-1, the final product Z-16 was 1.03 g (yield: 9%), MS (m / z) (M+): 1142.

[0215] Example 37

[0216] This embodiment provides a doped material compound Z-17, and the synthesis route of this compound is as follows:

[0217]

[0218] Using the same method as in Example 21, except that an equimolar amount of Y-17 (11.20 g; 10 mmol) was used to replace Y-1, the final product Z-17 was 1.57 g (yield: 15%), MS (m / z) (M+): 1049.

[0219] Example 38

[0220] This embodiment provides a doped material compound Z-18, and the synthesis route of this compound is as follows:

[0221]

[0222] Using the same method as in Example 21, except that an equimolar amount of Y-18 (11.59 g; 10 mmol) was used to replace Y-1, the final product Z-18 was 1.41 g (yield: 13%), MS (m / z) (M+): 1087.

[0223] Example 39

[0224] This embodiment provides a doped material compound Z-19, and the synthetic route of this compound is as follows:

[0225]

[0226] Using the same method as in Example 21, except that an equimolar amount of Y-19 (12.31 g; 10 mmol) was used to replace Y-1, the final product Z-19 was 1.62 g (yield: 14%), MS (m / z) (M+): 1160.

[0227] Example 40

[0228] This embodiment provides a doped material compound Z-20, and the synthesis route of this compound is as follows:

[0229]

[0230] Using the same method as in Example 21, except that an equimolar amount of Y-20 (10.24 g; 10 mmol) was used to replace Y-1, the final product Z-20 was obtained: 1.33 g (yield: 14%), MS (m / z) (M+): 953.

[0231] Composition Examples

[0232] Examples 41 to 60

[0233] This embodiment provides a composition 1 to a composition 20, wherein the host material compound and the dopant material compound are combined according to Table 1, wherein the mass ratio of the host material compound to the dopant material compound is 98:2, and the mixture is mixed evenly to obtain composition 1 to composition 20.

[0234] Table 1

[0235]

[0236]

[0237] Comparative Example 1

[0238] This comparative example provides a compound BH-1 that was tested during the research process, and its specific structural formula is as follows:

[0239]

[0240] Comparative Example 2

[0241] This comparative example provides a compound BH-2 that was tested during the research process, and its specific structural formula is as follows:

[0242]

[0243] Comparative Example 3

[0244] This comparative example provides a compound BD-1 that was tested during the research process, and its specific structural formula is as follows:

[0245]

[0246] Comparative Example 4

[0247] This comparative example provides a compound BD-2 that was tested during the research process, and its specific structural formula is as follows:

[0248]

[0249] Comparative examples of compositions

[0250] Comparative examples 5 to 73

[0251] This comparative example provides one of the comparative compositions 1 to 69 that were tested during the study. The host material compound and the dopant material compound were combined according to Table 2, wherein the mass ratio of the host material compound to the dopant material compound was 98:2. After being mixed evenly, comparative compositions 1 to 69 were obtained.

[0252] Table 2

[0253]

[0254]

[0255]

[0256] Composition performance evaluation

[0257] To illustrate the strong interaction between the host material compound and the dopant material compound in the composition provided by this invention, the molecular structure characteristics of the host material compound and the dopant material compound provided in Examples 1 to 40 and Comparative Examples 1 to 4 were calculated. Using Gaussian 09W software, based on the density functional theory (DFT) calculation method (basis set level set: b3lyp / 6-31g(d), charge number is 0), the molecular structure was geometrically optimized to obtain the dipole moments of the host material compound and the dopant material compound in the ground state.

[0258] Based on the dipole-dipole interaction formula between the host material compound and the dopant material compound:

[0259]

[0260] Where, μ D μ represents the dipole moment (in D) of the host material compound in the ground state. A R represents the dipole moment (in D) of a doped material compound in its ground state. DA R is the distance (in nm) between the host compound and the dopant compound. P represents the dipole-dipole interaction between the host and dopant compounds; a larger P indicates a stronger interaction and better energy transfer between them. Since the concentration of the dopant compound is the same in the host compound, the distance R between them is considered to be... DA Approximately the same, with a value of 1.5nm, assuming the host and guest orientations are the same, the dipole-dipole interactions between the host material compound and the dopant material compound in the compositions provided in Examples 41 to 60 and Comparative Examples 5 to 73 were calculated using the above formulas, and the specific calculation results are shown in Table 3.

[0261] Table 3. Results of composition performance tests

[0262]

[0263]

[0264]

[0265] As shown in Table 3, the P-value of the dipole-dipole interaction between the host material compound and the dopant material compound provided by this invention is ≥1.1, indicating that there is a strong interaction between the host material compound and the dopant material compound in the composition material provided by this invention, and the energy transfer between them is good. The good energy transfer between the host material compound and the dopant material compound can effectively improve the efficiency of organic electroluminescent devices. The host material compound provided by this invention contains a naphthanoquinone five-membered heterocyclic benzoquinone structure, which has higher stability compared with the anthracene structure. Moreover, this structure is located on one side of the anthracene and forms an asymmetric structure with the fused ring on the other side. This structure contains oxo-group heteroatoms, and the oxo-group atoms contain two pairs of lone pairs of electrons that do not participate in bonding, thus having a large electronegativity, making the material highly polar and easy to have a good interaction with the dopant material compound. The dopant compound provided by this invention contains benzothiophene fragments and cycloalkyl fragments. Through the interaction between the benzothiophene fragments and the cycloalkyl fragments, the dopant compound has a suitable polarity, which avoids both excessively low polarity resulting in insufficient host force and excessively high polarity leading to increased intermolecular aggregation and concentration quenching. In the composition provided by this invention, there is a strong interaction between the host compound and the dopant compound, which can improve the energy transfer between them.

[0266] The p-values ​​of dipole-dipole interactions between the doped material compounds provided in this invention and comparative compositions BH-1 or BH-2 are all ≤0.21, indicating that the interaction between the doped material compounds provided in this invention and comparative compositions BH-1 or BH-2 is relatively weak. The p-values ​​of dipole-dipole interactions between the host material compounds provided in this invention and comparative composition BD-1 are less than 1.05, indicating that the interaction between comparative composition BD-1 and the host material compounds provided in this invention is relatively weak. The p-values ​​of dipole-dipole interactions between the host material compounds provided in this invention and comparative composition BD-2 are greater than 1.25. This is because the asymmetry and planarity of the BD-2 molecule result in a large polarity. Although the dipole-dipole interaction between comparative composition BD-2 and the host material provided in this invention is relatively good, the excessive polarity of comparative composition BD-2 makes it prone to concentration quenching, increasing the risk of reduced device efficiency. The small P-value of the dipole-dipole interaction between compound BH1 or BH2 ​​and compound BD-1 or BD-2 indicates that the interaction between compound BH1 or BH2 ​​and compound BD-1 or BD-2 is weak and the energy transfer between them is poor.

[0267] Device Example 1

[0268] This embodiment provides a blue organic light-emitting diode (OLED), the fabrication method of which is as follows: First, a hole injection layer is formed on an ITO layer (anode) formed on a substrate by vacuum deposition of HTL and p-dopant (HTL to p-dopant mass ratio of 97:3) with a thickness of 10 nm; second, a hole transport layer is formed on the hole injection layer by vacuum deposition of HTL with a thickness of 120 nm; and third, a B2O3 layer is formed on the hole transport layer by vacuum deposition with a thickness of 5 nm. A light-emitting auxiliary layer is formed by depositing a prime material on the light-emitting auxiliary layer. Then, a light-emitting layer is formed on the light-emitting auxiliary layer by vacuum deposition of a composition of host material and dopant material with a thickness of 20 nm, wherein L-1 is the host material compound and Z-1 is the dopant material compound, with a mass ratio of host material compound to dopant material compound of 98:2. Next, a hole-blocking layer (HBL) is formed on the light-emitting layer by vacuum deposition with a thickness of 5 nm. An electron transport layer is formed by vacuum deposition of a mixture of ET and Liq (ET to Liq mass ratio of 1:1) with a thickness of 30 nm. Then, an electron injection layer is formed on the electron transport layer by depositing LiF with a thickness of 0.2 nm. Finally, an electron cathode is formed on the electron injection layer by depositing aluminum (Al) with a thickness of 150 nm, thus fabricating a blue organic light-emitting device.

[0269] Apart from the host material compound and dopant material compound of the luminescent layer, the molecular structure formulas of the other layers are as follows:

[0270]

[0271] 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.

[0272] Device Examples 2-30

[0273] The method is the same as in Device Example 1, except that the host material compound and the dopant material compound in the light-emitting layer are replaced with the combinations in Table 4.

[0274] Table 4 Comparison of host material compounds and dopant material compounds in device embodiments

[0275]

[0276]

[0277] Device Comparison Examples 1-5

[0278] The method is the same as in Device Example 1, except that the host material compound and the dopant material compound in the light-emitting layer are replaced with the combinations in Table 5.

[0279] Table 5 Comparison of host material compounds and dopant material compounds in device comparison examples.

[0280] Device Comparison Example 1 L-1 BD-2 Device Comparison Example 2 BH-1 Z-1 Device Comparison Example 3 BH-1 BD-1 Device Comparison Example 4 BH-1 BD-2 Device Comparison Example 5 BH-2 BD-1

[0281] Example 1 of device performance effect

[0282] The organic electroluminescent devices provided in Device Examples 1-30 and Comparative Examples 1-5 were tested using standard methods. For this purpose, J = 10 mA / cm² was used. 2 The driving voltage, luminance, electroluminescent current efficiency (in cd / A), and external quantum efficiency (EQE, in percentage) of the organic electroluminescent device were determined as a function of luminescence density from the current / voltage / luminescence density characteristic line (IVL characteristic line) exhibiting Lambertian emission characteristics, and the emission spectrum. The lifetime LT was defined as the time after which, when operating at a constant current J, the luminance decreased from the initial luminance L0 to a specific proportion L1; J = 50 mA / cm². 2 The statement L1 = 90% refers to a value of 50 mA / cm. 2 When operating below the threshold, the luminous intensity decreases to 90% of its initial value L0 after time LT. Similarly, J = 20 mA / cm² 2 L1 = 80% means that at 20 mA / cm 2 When operating below the threshold, the luminous intensity drops to 80% of its initial value L0 after time LT.

[0283] The testing instruments and methods used to perform performance testing on the above-mentioned OLED devices are as follows:

[0284] Brightness was tested using a PhotoResearch PR-635 spectral scanner;

[0285] Current density and turn-on voltage: tested using a Keithley 2400 digital source meter;

[0286] Life test: The LT-96ch life test device was used.

[0287] The performance test results of the above devices are listed in Table 6.

[0288] Table 6 Performance test results of blue light devices

[0289]

[0290] As can be seen from the device performance test results in Table 6 above, compared with Device Example 1 and Device Example 16, the efficiency and lifetime of Device Comparative Example 1 are significantly reduced. This is because the polarity of the comparative compound BH-1 is relatively small, and the interaction between it and the dopant compound is weak, resulting in poor energy transfer between the two and a decrease in the efficiency and lifetime of the organic electroluminescent device. Compared with Device Example 1 and Device Example 11, the efficiency and lifetime of Device Comparative Example 5 are significantly reduced. This is because the polarity of the comparative composition BD-2 is too large, which easily leads to concentration quenching, thereby causing a decrease in the efficiency and lifetime of the organic electroluminescent device. As can be seen from the device performance test results in Table 6 above, compared with the comparative device, the efficiency and lifetime of the organic electroluminescent device provided by the present invention are significantly improved. The main material compound provided by the present invention contains a naphthanoquinone five-membered heterocyclic benzoquinone five-membered heterocyclic structure, which has higher stability compared with the anthracene structure. Moreover, this structure is located on one side of the anthracene and forms an asymmetric structure with the fused ring on the other side. This structure contains oxo-group heteroatoms, and the oxo-group atoms contain two pairs of lone pairs of electrons that do not participate in bonding, thus having a large electronegativity, which makes the material have a large polarity and easily generate good interaction with the doped material compound. The dopant compound provided by this invention contains benzothiophene fragments and cycloalkyl fragments. Through the interaction between the benzothiophene fragments and the cycloalkyl fragments, the dopant compound has a suitable polarity. This avoids both excessively low polarity resulting in insufficient host force and excessively high polarity leading to increased intermolecular aggregation and concentration quenching. Furthermore, the strong interaction between the host compound and the dopant compound in the composition provided by this invention enhances energy transfer between them, thereby effectively improving the efficiency and extending the lifespan of organic light-emitting devices (OLEDs), overcoming the shortcomings of existing technologies.

[0291] Example 2 of device performance

[0292] The host material compound and dopant material compound in the luminescent layer material of Device Example 1 were replaced with the host material compound and dopant material compound in the compositions provided in Examples 41 to 60 and Comparative Examples 5 to 73, respectively. The mass ratio of the host material compound to the dopant material compound was changed to 99:1 to prepare experimental devices 1 to 89. The electroluminescence spectra of experimental devices 1 to 89 were tested under the same testing conditions as in Device Performance Example 1. The ordinate of the spectrum was logarithmically scaled, and the presence or absence of emission peaks was observed in the wavelength range of 400 nm to 440 nm. If an emission peak was present, it was recorded as the presence of host luminescence; if no emission peak was present, it was recorded as the absence of host luminescence. The electroluminescence spectrum of experimental device 86 is shown below. Figure 2 As shown (with emission peaks in the wavelength range of 400nm-440nm), the electroluminescence spectrum of experimental device 1 is as follows. Figure 3As shown (no emission peak in the wavelength range of 400nm-440nm), the main emission characteristics of experimental devices 1 to 89 are shown in Table 7.

[0293] Table 7 Bulk luminescence at low doping concentration

[0294]

[0295]

[0296]

[0297] As shown in Table 7, when the concentration of the dopant compound is reduced, i.e., the mass ratio of the host compound to the dopant compound is adjusted from 98:2 to 99:1, the organic electroluminescent device using the host compound and dopant compound provided by this invention as the light-emitting layer does not exhibit host emission, indicating good energy transfer between the host compound and the dopant compound provided by this invention. Therefore, the organic electroluminescent device prepared using the host compound and dopant compound provided by this invention as the light-emitting layer has high efficiency. The organic electroluminescent device using the host compound provided by this invention and comparative composition BD-1 as the light-emitting layer exhibits host emission, indicating poor energy transfer between comparative composition BD-1 and the host compound provided by this invention. The energy transfer between comparative composition BD-2 and the host compound provided by this invention is better, avoiding host emission. However, the device using comparative composition BD-2 as the dopant has lower efficiency because the polarity of comparative composition BD-2 is too high, making it prone to concentration quenching. Organic electroluminescent devices prepared using the doped material compound provided by this invention and BH-1 or BH-2 as luminescent materials exhibit main emission, indicating that the energy transfer between the comparative composition BH-1 or BH-2 and the doped material compound provided by this invention is poor.

[0298] 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. A composition, characterized in that, The composition comprises one or more organic compounds of formula I and one or more compounds of formula II; The organic compounds represented by Formula I are selected from the structures shown below: ； The organic compounds represented by Formula II are selected from the structures shown below: 。 2. An organic electroluminescent device, characterized in that, Includes a first electrode sequentially disposed on a substrate; configured to be connected with the... The second electrode opposite the first electrode; and one or more organic functional layers disposed between the first electrode and the second electrode; The organic functional layer includes a light-emitting layer, which comprises the composition of claim 1.

3. The organic electroluminescent device according to claim 2, characterized in that, The light-emitting layer comprises a host material and a dopant material. The host material comprises one or more compounds represented by chemical formula I, and the dopant material comprises one or more compounds represented by chemical formula II.

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