An organic compound, a preparation method and application thereof

Abstract

The present application provides an organic compound and its application, the organic compound has the structure shown in the following formula I, the compound has good thermal stability and film forming property, suitable glass transition temperature Tg, is conducive to forming stable, uniform thin film in the process of thermal vacuum evaporation, while reducing phase separation, maintaining the stability of the device. Higher carrier transport rate and balanced carrier transport performance, conducive to the balance of hole and electron transport in the device while obtaining a wider carrier recombination region, improving the light emitting efficiency.

Description

Technical Field

[0001] This invention belongs to the field of organic light-emitting materials technology, and relates to an organic compound and its applications. Background Technology

[0002] Organic light-emitting diodes (OLEDs), as a new generation of display technology, have advantages such as ultra-thinness, self-illumination, wide viewing angle, fast response, high luminous efficiency, good temperature adaptability, simple production process, low driving voltage, and low energy consumption. They have been widely used in industries such as flat panel displays, flexible displays, solid-state lighting, and automotive displays.

[0003] Based on their luminescence mechanisms, phosphorescence can be classified into two types: electrofluorescence and electrophosphorescence. Fluorescence is the light emitted when a singlet exciton undergoes a radiative decay transition, while phosphorescence is the light emitted when a triplet exciton radiatively decays to its ground state. According to spin quantum statistics theory, the probability ratio of singlet to triplet exciton formation is 1:3. Fluorescent materials are limited to an internal quantum efficiency of no more than 25%, and their external quantum efficiency is generally below 5%. Electrophosphorescent materials, on the other hand, theoretically achieve an internal quantum efficiency of 100% and an external quantum efficiency of up to 20%. In 1998, Professor Ma Yuguang of Jilin University in my country and Professor Forrest of Princeton University in the United States reported the first successful observation and explanation of phosphorescent electroluminescence by using osmium complexes and platinum complexes as dyes doped into the luminescent layer. They also pioneered the application of the prepared phosphorescent materials in electroluminescent devices.

[0004] Because phosphorescent heavy metal materials have a long lifetime (μs), high current densities can lead to triplet-triplet annihilation and concentration quenching, causing device performance degradation. Therefore, heavy metal phosphorescent materials are often doped into suitable host materials to form a host-guest doping system, optimizing energy transfer and maximizing luminous efficiency and lifetime. In the current research landscape, commercially viable heavy metal doped materials are mature, making it difficult to develop alternative doping materials. Therefore, focusing on the development of phosphorescent host materials is a common approach among researchers. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide an organic compound and its application.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] One object of the present invention is to provide an organic compound having the structure shown in Formula I:

[0008]

[0009] Where X is selected from O, S, N, C or R1 and R2 are independently selected from C1-C5 alkyl groups;

[0010] L is selected from substituted or unsubstituted C5-C30 aryl groups and substituted or unsubstituted C5-C30 heteroaryl groups;

[0011] Y is selected from substituted or unsubstituted C5-C30 aryl groups and substituted or unsubstituted C5-C30 heteroaryl groups.

[0012] The compounds of this invention exhibit strong planarity and good stability in their macrocyclic structures, which is beneficial for charge transport and device stability. Furthermore, the macrocyclic structure of these compounds comprises electron-donating groups connected to electron-accepting groups via linker groups, resulting in a bipolar molecule that facilitates the transport of holes and electrons. This allows for smaller overlap between HOMO and LUMO energy levels, leading to higher luminous efficiency. The compounds also possess excellent thermal and thin-film stability, resulting in greater stability during OLED device operation. This contributes to the fabrication and extended lifetime of OLED devices, making them a high-performance luminescent material.

[0013] A second objective of this invention is to provide a light-emitting layer material, which includes the organic compound described in one objective of this invention.

[0014] A third objective of this invention is to provide an OLED device, the OLED device comprising an anode, a cathode, and an organic thin film layer located between the anode and the cathode, wherein the material of the organic thin film layer comprises an organic compound as described in one objective of this invention.

[0015] A fourth objective of the present invention is to provide a display panel comprising an OLED device as described in a third objective of the present invention.

[0016] The fifth objective of this invention is to provide an organic light-emitting display device, including the display panel as described in the fourth objective of this invention.

[0017] The sixth objective of this invention is to provide an electronic device comprising a display panel as described in the fourth objective of this invention.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The organic compounds of this invention possess excellent thermal stability and film-forming properties, along with a suitable glass transition temperature (Tg), which facilitates the formation of stable and uniform thin films during thermal vacuum evaporation, while simultaneously reducing phase separation and maintaining device stability. They exhibit high carrier transport rates and balanced carrier transport performance, promoting a balance between hole and electron transport within the device and achieving a wider carrier recombination region, thereby improving luminous efficiency. The organic compounds of this invention can significantly improve the efficiency and lifetime of OLED devices while reducing the driving voltage. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the OLED device of the present invention, wherein 1 is a substrate, 2 is an anode, 3 is a first hole transport layer, 4 is a second hole transport layer, 5 is a light-emitting layer, 6 is a first electron transport layer, 7 is a second electron transport layer, 8 is a cathode, and 9 is a capping layer. Detailed Implementation

[0021] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0022] One object of the present invention is to provide an organic compound having the structure shown in Formula I:

[0023]

[0024] Where X is selected from O, S, N, C or R1 and R2 are independently selected from C1-C5 alkyl groups;

[0025] L is selected from substituted or unsubstituted C5-C30 aryl groups and substituted or unsubstituted C5-C30 heteroaryl groups;

[0026] Y is selected from substituted or unsubstituted C5-C30 aryl groups and substituted or unsubstituted C5-C30 heteroaryl groups.

[0027] In this invention, C5 to C30 can each independently be C6, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28, C29, etc.

[0028] In this invention, C1-C5 can be C1, C2, C3, C4 or C5.

[0029] In some preferred embodiments, L is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthraquinyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted dibenzofuranyl, or substituted or unsubstituted dibenzothiopheneyl.

[0030] In some preferred embodiments, Y is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthraquinyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted benzopyrimidinyl, substituted or unsubstituted triazineyl or cyano.

[0031] In some preferred embodiments, the substituents in the substituted groups are selected from halogens, C1-C5 (e.g., C1, C2, C3, C4, or C5) alkyl groups, C1-C5 (e.g., C1, C2, C3, C4, or C5) alkoxy groups, C5-C12 (e.g., C5, C6, C7, C8, C9, C10, C11, or C12) aryl groups, and C5-C12 (e.g., C5, C6, C7, C8, C9, C10, C11, or C12) heteroaryl groups.

[0032] In some preferred embodiments, L is selected from

[0033] In some preferred embodiments, Y is selected from cyano, phenyl, naphthyl, cyano-substituted phenyl, cyano-substituted naphthyl, pyridyl,

[0034] In some preferred embodiments, the organic compound includes any one of the following compounds:

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041] A second objective of this invention is to provide a light-emitting layer material, which includes the organic compound described in one objective of this invention.

[0042] A third objective of this invention is to provide an OLED device, the OLED device comprising an anode, a cathode, and an organic thin film layer located between the anode and the cathode, wherein the material of the organic thin film layer comprises an organic compound as described in one objective of this invention.

[0043] In some preferred embodiments, the organic thin film layer includes a light-emitting layer comprising a host material and a dopant material, the host material comprising an organic compound as described in one of the objectives.

[0044] In some preferred embodiments, the organic thin film layer further includes any one or a combination of at least two of the following: a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, or an electron injection layer.

[0045] In the OLED device provided by this invention, the anode material can be a metal, a metal oxide, or a conductive polymer; wherein the metal includes copper, gold, silver, iron, chromium, nickel, manganese, palladium, platinum, and their alloys; the metal oxide includes indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide, indium gallium zinc oxide (IGZO), etc.; and the conductive polymer includes polyaniline, polypyrrole, poly(3-methylthiophene), etc. In addition to the above-mentioned materials and combinations thereof that facilitate hole injection, known materials suitable for anodes are also included.

[0046] In the OLED device, the cathode material can be a metal or a multilayer metal material; wherein the metal includes aluminum, magnesium, silver, indium, tin, titanium, etc., and their alloys, and the multilayer metal material includes LiF / Al, LiO2 / Al, BaF2 / Al, etc. In addition to the above-mentioned materials and combinations that facilitate electron injection, known materials suitable for use as cathodes are also included.

[0047] The OLED device can be fabricated by forming an anode on a smooth, transparent or opaque substrate, forming an organic thin layer on the anode, and forming a cathode on the organic thin layer. The organic thin layer can be formed using known film-forming methods such as evaporation, sputtering, spin coating, immersion, and ion plating.

[0048] A fourth objective of the present invention is to provide a display panel comprising an OLED device as described in a third objective of the present invention.

[0049] The fifth objective of this invention is to provide an organic light-emitting display device, including the display panel as described in the fourth objective of this invention.

[0050] The sixth objective of this invention is to provide an electronic device comprising a display panel as described in the fourth objective of this invention.

[0051] The synthesis of the compound structure of this invention can be accomplished through the following reaction process:

[0052]

[0053] The following are exemplary examples of the preparation of the organic compounds described in this invention:

[0054] Preparation Example 1

[0055] Synthesis of compound A01

[0056]

[0057] 1) Preparation of intermediate A-201

[0058] In a flask, 350 mmol of A-101, 520 mmol of D01, 17.3 mmol of tetra(triphenylphosphine)palladium(O)(Pd(PPh3)4), and 875 mmol of potassium carbonate were dissolved in 1500 mL of tetrahydrofuran and 400 mL of distilled water, and the mixture was refluxed at 100 °C for 18 hours. After the reaction was complete, the organic layer was extracted with ethyl acetate, the remaining water was removed with magnesium sulfate, the residue was dried, and the intermediate A-201 was obtained by column chromatography.

[0059] 2) Preparation of intermediate A-301

[0060] 83 mmol of A-201, 16.5 mmol of Pd(OAc)2, 25 mmol of the ligand (tricyclohexylphosphine tetrafluoroborate), 248 mmol of Cs2CO3, and 400 mL of dimethylacetamide (DMA) were stirred under reflux for 3 hours. The mixture was cooled to room temperature and distilled water was added. The mixture was extracted with dichloromethane (MC) and dried over magnesium sulfate. The residue was distilled under reduced pressure and separated by column chromatography to give intermediate A-301.

[0061] 3) Preparation of intermediate A-401

[0062] 17.3 mmol of A-301, 19.8 mmol of BO1, 0.80 mmol of tris(dibenzylacetone)dipalladium(O), 1.57 mmol of tri-tert-butylphosphine (50% toluene solution), 31.4 mmol of sodium tert-butoxide, and 160 mL of toluene were introduced into a flask, and the mixture was refluxed for 4 hours. The reaction solution was cooled to room temperature, and the solvent was then removed by rotary evaporator. The residue was separated by column chromatography to give intermediate A-401.

[0063] 4) Preparation of A01

[0064] In a flask, 20 mmol of A-401, 22 mmol of B01, 0.98 mmol of tetra(triphenylphosphine)palladium(O)(Pd(PPh3)4), and 49 mmol of potassium carbonate were dissolved in 100 mL of tetrahydrofuran and 25 mL of distilled water, and the mixture was refluxed at 100 °C for 18 hours. After the reaction was complete, the organic layer was extracted with ethyl acetate, the remaining water was removed with magnesium sulfate, the residue was dried, and the reactant A01 was separated by column chromatography.

[0065] MALDI-TOF: m / z: calculated value: C43H22O2N2: 598.17, measured value: 598.39.

[0066] Elemental analysis results of the compound: Calculated values: C, 86.27; H, 3.70; O, 5.34; N, 4.68; Analyzed values: C, 86.26; H, 3.71; O, 5.36; N, 4.67.

[0067] The synthesis methods in other embodiments are similar, the only difference being the different reactants. The preparation of Examples 2-11 can be found in Table 1 below:

[0068] Table 1

[0069]

[0070]

[0071]

[0072] Synthesis of compound AA (component A):

[0073] The comparative compound AA was prepared using the following reaction procedure:

[0074]

[0075] 20 mmol of AA-1 (CAS No.: 109606-75-9, purchased from Suzhou Nuoxing Trading Co., Ltd.), 20 mmol of AA-2, 0.75 mmol of tris(dibenzylacetone)dipalladium(0), 1.53 mmol of tri-tert-butylphosphine (50% toluene solution), 30.5 mmol of sodium tert-butoxide, and 150 mL of toluene were introduced into a flask, and the mixture was refluxed for 6 hours. The reaction solution was cooled to room temperature, and the solvent was removed by rotary evaporator. The residue was separated by column chromatography to obtain product AA.

[0076] MALDI-TOF: m / z: calculated value: C39H24N4: 548.20, measured value: 548.46.

[0077] Elemental analysis results of the compound: Calculated values: C, 85.38; H, 4.41; N, 10.21 Measured values: C, 85.37; H, 4.42; N, 10.21.

[0078] Device Example 1

[0079] This embodiment of the device provides an OLED device, such as... Figure 1 As shown, Figure 1The schematic diagram of the organic light-emitting device provided by the present invention includes a substrate 1, an anode 2, a first hole transport layer 3, a second hole transport layer 4, a light-emitting layer 5, a first electron transport layer 6, a second electron transport layer 7, a cathode 8, and a capping layer 9, which are stacked sequentially. The indium tin oxide (ITO) anode is 15nm, the first hole transport layer is 10nm, the second hole transport layer is 95nm, the light-emitting layer is 30nm, the first electron transport layer is 35nm, the second electron transport layer is 5nm, the cathode is 15nm (magnesium-silver electrode, magnesium-silver mass ratio is 1:9), and the capping layer (CPL) is 100nm.

[0080] The fabrication steps of OLED devices are as follows:

[0081] (1) Cut the glass substrate 1 into 50mm×50mm×0.7mm pieces, sonicate them in isopropanol and deionized water for 30min respectively, and then clean them under ozone for 10min; mount the glass substrate with ITO anode 2 obtained by magnetron sputtering onto the vacuum deposition equipment.

[0082] (2) In a vacuum of 2×10 -6 At Pa, HAT-CN compound with a thickness of 10 nm was vacuum-deposited on the ITO anode layer 2 as the first hole transport layer 3.

[0083] (3) A compound TAPC is vacuum-deposited on the first hole transport layer 3 as a second hole transport layer 4 with a thickness of 95 nm;

[0084] (4) A light-emitting layer 5 is vacuum-deposited on the second hole transport layer 4, using the organic compound A01 provided by the present invention as the main material and Ir(piq)2(acac) as the dopant material. The mass ratio of A01 to Ir(piq)2(acac) is 97:3 and the thickness is 30nm.

[0085] (5) A compound BCP is vacuum-deposited on the light-emitting layer 5 as the first electron transport layer 6 with a thickness of 35 nm;

[0086] (6) The compound Alq3 was vacuum-deposited on the first electron transport layer 6 as the second electron transport layer 7 with a thickness of 5 nm;

[0087] (7) A magnesium-silver electrode is vacuum-deposited on the second electron transport layer 7 as a cathode 8, with a Mg to Ag mass ratio of 1:9 and a thickness of 15 nm.

[0088] (8) A high-refractive-index compound CBP with a thickness of 100 nm is vacuum-deposited on the cathode 8 and used as a cathode capping layer (capping layer) 9.

[0089] The compound structure used in the OLED device is as follows:

[0090]

[0091] Device Examples 2-11

[0092] In device example 1, the organic compound A01 in step (4) is replaced with equal amounts of compounds A06, A08, A11, A20, A58, A63, A71, A82, A102 or A110, and the other preparation steps are the same as in device example 1.

[0093] Device Comparison

[0094] An OLED device, which differs from device example 1 only in that the organic compound A01 in step (4) is replaced with an equal amount of the comparative compound AA. Replacement; other raw materials and preparation steps are the same.

[0095] Performance evaluation of OLED devices:

[0096] The current of the OLED device at different voltages was measured using a Keithley 2365A digital nanovoltmeter, and then the current density of the OLED device at different voltages was obtained by dividing the current by the emitting area. The brightness of the OLED device at different voltages was measured using a Konicaminolta CS-2000 spectroradiometer. Based on the current density and brightness of the OLED device at different voltages, the current density at the same current density (10 mA / cm²) was obtained. 2 The operating voltage Von and current efficiency Cd / A of the OLED device were measured; the lifetime LT95 was obtained by measuring the time it took for the OLED device to reach 95% of its initial brightness; the voltage, efficiency, and lifetime LT95 of the device were taken as 100% for the comparative device, and the specific data are shown in Table 2.

[0097] Table 2 Performance evaluation results of OLED devices

[0098] OLED devices Light-emitting layer material <![CDATA[Von / V REF ]]> <![CDATA[CE / CE REF ]]> <![CDATA[LT95 / LT95 REF ]]> Device Example 1 A01 97.2％ 105.4％ 106.7％ Device Example 2 A06 98.3％ 106.2％ 107.4％ Device Example 3 A08 97.8％ 105.7％ 104.8％ Device Example 4 A11 98.5％ 106.7％ 104.5％ Device Example 5 A20 97.9％ 105.0％ 105.7％ Device Example 6 A58 98.3％ 106.4％ 104.8％ Device Example 7 A63 98.0％ 105.7％ 106.2％ Device Example 8 A71 97.4％ 104.9％ 105.6％ Device Example 9 A82 97.8％ 104.7％ 106.2％ Device Example 10 A102 98.6％ 106.8％ 105.9％ Device Example 11 A110 97.7％ 105.8％ 107.1％ Device Comparison AA 100％ 100％ 100％

[0099] As can be seen from Table 2 (V in Table 2) on / V REF(The operating voltage of the device is calculated as 100% of the operating voltage of the device comparison model). The OLED device provided by this invention has a low operating voltage, high luminous efficiency, and long lifetime. This is due to the special structure of the compound of this invention. The macrocyclic structure of this invention has strong planarity and good stability, which is beneficial to charge transport and device stability. The macrocyclic structure of the compound of this invention is an electron-donating group, which is connected to an electron-accepting group through a linker group. The whole molecule exhibits bipolar characteristics, which is beneficial to the transport of holes and electrons and has the potential to achieve less overlap of HOMO and LUMO energy levels, thus achieving high luminous efficiency. The compound of this invention has excellent thermal stability and thin film stability, which makes it more stable when the OLED device is working, which is beneficial to the preparation of OLED devices and obtaining a longer lifetime. It is a high-performance luminescent material.

[0100] The applicant declares that the above embodiments illustrate the organic compounds and their applications, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organic compound, characterized in that, The organic compound has the structure shown in Formula I: Formula I Where X is selected from O, S, , or R1 and R2 are independently selected from C1-C5 alkyl groups; L is selected from , or ; Y is selected from phenyl, naphthyl, cyano-substituted phenyl, cyano-substituted naphthyl, pyridyl, , , , , , , , or , , , , , , , .

2. The organic compound according to claim 1, characterized in that, The organic compound is any one of the following compounds: 。 3. A light-emitting layer material, characterized in that, The light-emitting layer material includes the organic compound as described in claim 1 or 2.

4. An OLED device, characterized in that, The OLED device includes an anode, a cathode, and an organic thin film layer located between the anode and the cathode, wherein the material of the organic thin film layer includes the organic compound as described in claim 1 or 2.

5. The OLED device according to claim 4, characterized in that, The organic thin film layer includes a light-emitting layer, which comprises a host material and a dopant material, wherein the host material comprises an organic compound as described in claim 1 or 2.

6. The OLED device according to claim 4, characterized in that, The organic thin film layer includes any one or a combination of at least two of the following: a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, or an electron injection layer.

7. A display panel, characterized in that, The display panel includes an OLED device as described in any one of claims 4-6.

8. An organic light-emitting display device, characterized in that, Includes the display panel as described in claim 7.

9. An electronic device, characterized in that, The electronic device includes the display panel as described in claim 7.

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