Organic electroluminescent material and organic electroluminescent device

Abstract

The invention provides an organic electroluminescent material and an organic electroluminescent device, the organic electroluminescent material has the following structure: M (LA) 2 (LB), the organic electroluminescent device provided by the invention adopts a doping material with a specific atomic structure, and one or more benzene ring groups are thickened on a benzopyran or benzothiapyran ring, so that the organic electroluminescent device can be used for preparing the organic electroluminescent device. By adjusting the size and shape of the spatial structure of the obtained substance, the molecular spatial configuration of the compound is extended, the electrochemical property of the compound is adjusted, and the symmetric dipole moment between molecules is improved, so that after the obtained organic compound is applied to the organic electroluminescent device, the device has the characteristics of long service life, high efficiency and low driving voltage.

Description

Technical Field

[0001] The present invention belongs to the technical field of electroluminescent materials, and relates to an organic electroluminescent material and an organic electroluminescent device. Background Art

[0002] In 1987, Tang and Van Slyke of Eastman Kodak reported a bilayer organic electroluminescent device, which included an arylamine hole transport layer and a tris-8-hydroxyquinoline-aluminum layer as an electron transport layer and a light-emitting layer. Once a bias voltage was applied to the device, green light was emitted from the device. This invention laid the foundation for the development of modern organic light-emitting diodes (OLEDs). The state-of-the-art OLEDs can include multiple layers, such as charge injection and transport layers, charge and exciton blocking layers, and one or more light-emitting layers between the cathode and the anode. Since OLEDs are a self-luminous solid-state device, it offers great potential for display and lighting applications. In addition, the inherent properties of organic materials, such as their flexibility, can make them very suitable for special applications, such as fabrication on flexible substrates.

[0003] As an organic electroluminescent diode for next-generation flat panel display applications, organic optoelectronic semiconductor materials are required to have: 1. high luminous efficiency; 2. excellent electron and hole stability; 3. appropriate emission color; 4. excellent film-forming processability. For various reasons, optoelectronic devices using organic materials have become increasingly popular. Many of the materials used to fabricate such devices are relatively inexpensive, so organic optoelectronic devices have the potential for cost advantages over inorganic devices. Additionally, the inherent properties of organic materials (such as their flexibility) can make them more suitable for specific applications, such as fabrication on flexible substrates. Examples of organic optoelectronic devices include organic light-emitting diodes / devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, organic materials can have performance advantages over conventional materials.

[0004] However, in the prior art, when phosphorescent materials are applied to organic light-emitting devices, there are problems of low efficiency and short lifespan. Therefore, how to provide an organic electroluminescent material with a long lifespan, high efficiency, and low driving voltage is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the object of the present invention is to provide an organic electroluminescent material and an organic electroluminescent device. The organic electroluminescent device provided by the present invention adopts a doping material with a specific atomic structure. By condensing one or more benzene ring groups on the benzopyran or benzothiopyran ring, the spatial structure size and morphology of the obtained substance are adjusted, the spatial configuration of the compound molecule is extended, the electrochemical properties of the compound are adjusted, the symmetric dipole moment between molecules is improved, so that after the obtained organic compound is used in the organic electroluminescent device, the device has the characteristics of long life, high efficiency and low driving voltage.

[0006] To achieve the object of the present invention, the following technical solutions are adopted:

[0007] On the one hand, the present invention provides an organic electroluminescent material, and the organic electroluminescent material has the following structure: M(L A ) 2 (L B );

[0008] Wherein the ligands L A and L B have the following structures:

[0009]

[0010] In formulas L A and L B , R 1 , R 2 , R 3 , Ar 1 , Ar 2 , Ar 3 , Ar 4 and Ar 5 are each independently selected from -H, -D (deuterium), -T (tritium), -F, -CN, -CH 3 , -CD 3 , -CT 3 , -CF 3 , -CH 2 F, -CHF 2 , -Ge(Me) 3 , -Si(Me) 3 , any one of substituted or unsubstituted C2-C10 alkyl, substituted and unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C20 aryl and substituted or unsubstituted 4-membered - 20-membered aromatic heterocyclic group;

[0011] Wherein, m is an integer between 0 and 4 (for example, 0, 1, 2, 3 or 4);

[0012] n is an integer between 0 and 2 (for example, 0, 1 or 2);

[0013] q is an integer between 0 and 2 (e.g., 0, 1, or 2);

[0014] p is an integer between 0 and 3 (e.g., 0, 1, 2, or 3);

[0015] r is an integer between 0 and 1;

[0016] X is O or S;

[0017] Ring H is a 4- to 8-membered aryl or heteroaryl; Ring H is fused to any fusible position of the ring it is in with a dashed line;

[0018] M is the metal Ir;

[0019] Formula L A and L B The hydrogen in can be undeuterated, partially deuterated, or fully deuterated.

[0020] In the present invention, Ar 1 、Ar 2 、Ar 3 、Ar 4 and Ar 5 are connected to the parent nucleus structure by a dashed line, and the dashed line represents a connecting bond, indicating that the connecting position can be any connectable position of the ring it is in.

[0021] Preferably, Ring H is a benzene ring.

[0022] Specifically, Formula L A has the following specific structure:

[0023]

[0024] wherein, R 1 、R 2 、R 3 、Ar 1 、Ar 2 、Ar 3 、Ar 4 and Ar 5 are the same as those described above and will not be elaborated;

[0025] m 1 、m 2 and m 3 are respectively integers between 0 and 4 (e.g., 0, 1, 2, 3, or 4), n 1 、n 2 、n 3 and q are respectively integers between 0 and 2 (e.g., 0, 1, or 2), p is an integer between 0 and 3 (e.g., 0, 1, 2, or 3), and r is an integer between 0 and 1;

[0026] Formula LA1 to L A3 The hydrogen atom in may be undeuterated, partially deuterated, or fully deuterated.

[0027] In the present invention, the structure of the organic electroluminescent material is shown in Formula I:

[0028]

[0029] wherein the definition of the group is the same as that in Formula L A and L B is the same.

[0030] Furthermore, R 1 -R 3 and Ar 1 -Ar 5 are independently selected from the following groups: -H, -D (deuterium), -T (tritium), -F, -CN, -CH 3 and -CD 3 and -CT 3 and -CF 3 and -CH 2 F, -CHF 2 and -Ge(Me) 3 and -Si(Me) 3 methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, thiolane, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl, anthryl, triphenylene, tetraphenyl, fluoranthenyl, furyl, thienyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, benzofuryl, benzothienyl, isobenzofuryl, dibenzofuryl, dibenzothienyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, carbazolyl, phenanthridinyl, etc.

[0031] In the present invention, "substituted" means that it can be substituted by one group or at least two groups selected from the following groups: -D (deuterium), -T (tritium), -F, -CN, -CH 3 and -CD 3 and -CT 3 and -CF 3 and -CH 2 F, -CHF 2 and -Ge(Me) 3 and -Si(Me) 3, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, thiacyclopentyl, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthrenyl, anthracenyl, triphenylene, tetraphenylene, fluoranthenyl, furyl, thienyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, benzofuryl, benzothienyl, isobenzofuryl, dibenzofuryl, dibenzothienyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, carbazolyl or phenanthridinyl.

[0032] Preferably, the organometallic compound is selected from any one of the following compounds:

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

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[0059]

[0060]

[0061]

[0062]

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[0064]

[0065]

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[0070]

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[0082]

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[0085]

[0086]

[0087]

[0088]

[0089] In the present invention, the preparation process of the organic electroluminescent material is as follows:

[0090]

[0091] The definition of the groups in the above formula is the same as that above, and will not be repeated here.

[0092] The specific synthesis steps are as follows:

[0093] 1. Under nitrogen protection, the compound of formula L A structure and IrC1 3 ·3H 2 O are put into the reaction system, a mixed solution of ethylene glycol monoethyl ether and pure water is added, and the reaction is refluxed under nitrogen protection. Then it is cooled to room temperature, and a precipitate is precipitated. The precipitate is filtered by suction and washed successively with water, absolute ethanol, and petroleum ether and then dried. The bridged ligand compound shown in formula II is obtained.

[0094] 2. Weigh the intermediate compound of formula II and anhydrous potassium carbonate, add ethylene glycol monoethyl ether, and then add the ligand of formula L B , and the reaction is refluxed under nitrogen protection, filtered by suction, washed with alcohol, and dried. Using dichloromethane as the solvent, silica gel column chromatography is carried out, and the filtrate is concentrated to precipitate a solid, and the final product of the compound shown in formula I is obtained.

[0095] On the other hand, the present invention provides an organic electroluminescent device, which includes an anode and a cathode, and an organic thin film layer disposed between the anode and the cathode. The organic thin film layer includes a light-emitting layer, and the light-emitting layer includes a host material and a doping material. The doping material includes the organic electroluminescent material as described above.

[0096] The light-emitting layer may include light-emitting dyes (i.e., dopants) that can emit spectra of different wavelengths, and may also include a host material at the same time. The light-emitting layer may be a monochromatic light-emitting layer that emits a single color such as red, green, or blue. Multiple different-color monochromatic light-emitting layers may be arranged flat according to a pixel pattern, or may be stacked together to form a color light-emitting layer. When different-color light-emitting layers are stacked together, they may be separated from each other or connected to each other. The light-emitting layer may also be a single color light-emitting layer that can simultaneously emit different colors such as red and green.

[0097] According to different technologies, the light-emitting layer material may adopt different materials such as phosphorescent electroluminescent materials and thermally activated delayed fluorescence light-emitting materials. In an OLED device, a single light-emitting technology may be adopted, or a combination of multiple different light-emitting technologies may be adopted. These different light-emitting materials classified by technology may emit light of the same color or different colors.

[0098] Preferably, the light-emitting layer of the present invention adopts the technology of phosphorescent electroluminescence.

[0099] Preferably, the organic thin film layer further includes at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

[0100] Preferably, the organic electroluminescent device 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 transport layer, an electron injection layer, and a cathode disposed in sequence.

[0101] Generally speaking, an organic electroluminescent device includes a first electrode (anode) and a second electrode (cathode), and an organic material layer located between the electrodes. The organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0102] In a specific embodiment, a substrate may be used below the first electrode or above the second electrode. The substrates are all glass or polymer materials with excellent mechanical strength, thermal stability, waterproofness, and transparency. In addition, a thin film transistor (TFT) may also be provided on the substrate for use as a display.

[0103] The first electrode can be formed by sputtering or depositing a material used as the first electrode on a substrate. When the first electrode serves as an anode, oxide transparent conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), etc. and any combination thereof can be used. In addition, the anode material can also be selected from materials and their combinations that contribute to hole injection other than the listed anode materials, including known materials suitable for making anodes. When the first electrode serves as a cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), etc. and any combination thereof can be used. In addition to the listed cathode materials above, the cathode material can also be a material and its combination that contribute to electron injection, including known materials suitable for making a cathode.

[0104] The organic material layer can be formed on the electrode by methods such as vacuum thermal evaporation, spin coating, printing, etc. Compounds used as the organic material layer can be organic small molecules, organic macromolecules, and polymers, as well as their combinations. The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a single-layer hole transport layer (HTL), including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multi-layer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0105] The material of the hole transport layer can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as poly(phenylene vinylene), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), aromatic amine derivatives such as the compounds shown as HT-1 to HT-34 below; or any combination thereof.

[0106]

[0107]

[0108]

[0109] However, it is not limited to the above several materials.

[0110] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can adopt one or more of the above-mentioned compounds HT-1 to HT-34, or one or more of the following compounds HI-1 to HI-3; it can also adopt one or more of the compounds HT-1 to HT-34 doped with one or more of the compounds HI-1 to HI-3:

[0111]

[0112] However, it is not limited to the above several materials.

[0113] The OLED organic material layer may further include an electron transport region between the light-emitting layer and the cathode. The electron transport region can be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region can also be a multi-layer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0114] In one aspect of the present invention, the electron transport layer material can be selected from, but not limited to, one or more combinations of the following listed ET-1 to ET-57:

[0115]

[0116]

[0117]

[0118]

[0119] However, it is not limited to the above several materials.

[0120] The device may further include an electron injection layer between the electron transport layer and the cathode, and the electron injection layer material includes but is not limited to one or more combinations of the following listed: LiF, NaCl, CsF, Li 2 O, Cs 2 CO 3 , BaO, Na, Li, Ca.

[0121] On the other hand, the present invention also provides a display panel, including the above-mentioned organic electroluminescent device.

[0122] For the prior art, the present invention has the following beneficial effects:

[0123] 1. The organic electroluminescent material of the present invention adjusts the spatial structure size and morphology of the obtained substance by condensing one or more benzene ring groups on the benzopyran or benzothiopyran ring, extends the spatial configuration of the compound molecule, adjusts the electrochemical properties of the compound, and improves the intermolecular symmetric dipole moment, so that when the compound is applied to an organic electroluminescent device, the starting voltage is reduced, the efficiency is increased, and the lifespan is extended.

[0124] 2. In the research on the diketone ligand part of iridium complexes, a complete theoretical system has not been formed so far. Since the carbon atoms on the side chain do not participate in conjugation, they have a certain but not significant impact on the electron cloud distribution. At the same time, the present invention finds that the length, configuration, and group size of the branched alkyl chain have a certain impact on the performance indicators such as the wavelength, full width at half maximum, efficiency, lifespan, and CIE coordinates of the doped material. More importantly, for different RH materials, the molecular structure of the diketone ligand is regulated to make RH and RD match each other, so as to obtain a better material with excellent performance for application to the device, making its performance better, the starting voltage reduced, the efficiency increased, and the lifespan extended.

[0125] The light-emitting layer of the organic electroluminescent device of the present invention is composed of a specific doped material and a host material, and cooperating with other layer materials can effectively reduce the turn-on voltage of the obtained organic electroluminescent device, improve the efficiency, and solve the problem of low lifespan. BRIEF DESCRIPTION OF THE DRAWINGS

[0126] Figure 1 is the nuclear magnetic resonance hydrogen spectrum of Compound Ⅰ-608 prepared in the synthesis example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0127] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0128] Synthesis Example 1

[0129] This synthesis example provides an organometallic compound Ⅰ-91, that is, the compound numbered Ⅰ-91. The specific synthesis steps are as follows:

[0130]

[0131] Under a nitrogen protection system, 4-bromo-3-chlorophenanthrene (CAS: 2924419-31-6, 1.0 eq) and methanol are added in sequence, and sodium methoxide (1.0 eq) is added in batches. After adding, the temperature is raised to reflux for 5.5 hours. After the reaction is completed, activated carbon (0.01 eq) is added to the reaction solution for decolorization, filtered, concentrated to dryness, added with ice water (1.0 eq), stirred and slurried, filtered, and the filter cake is dried at 50 °C to obtain the shown compound formula LAC -91 (yield 78%), the intermediate compound of formula L AC -91 was subjected to the following analytical tests:

[0132] HPLC purity: greater than 99.5%.

[0133]

[0134] Under a nitrogen protection system, compound of formula L AC -91 (1.0 eq), bis(pinacolato)diboron (1.0 eq), X-Phos (0.2 eq), palladium(II) acetate (0.01 eq), potassium acetate (3.0 eq) and dioxane were successively added to the reaction system, and N 2 was displaced three times and N 2 was protected, and the mixture was heated with stirring at 100 °C overnight. After the reaction was completed, it was filtered through diatomaceous earth and anhydrous magnesium sulfate, washed twice with ethyl acetate, and the organic phase was collected and concentrated under reduced pressure to obtain the crude product of intermediate formula L AB -91, which was directly used for the next step.

[0135]

[0136] Under a nitrogen protection system, compound of formula L AB -91 (1.2 eq), 1-chloroisoquinolin-8-amine (CAS: 1374652-59-1) (1.0 eq), and anhydrous potassium carbonate (3.0 eq) were placed in the reaction system, toluene, absolute ethanol, and purified water were added, and Pd(PPh 3 ) 4 (0.02 eq) was added under nitrogen protection. The mixture was refluxed at 100 °C for 26 h under nitrogen protection. After the reaction was completed, liquid separation was carried out, and it was extracted with ethyl acetate and washed three times with saturated brine, and then concentrated under reduced pressure. 400 ml of dichloromethane was added to dissolve it, and the solution was subjected to column chromatography (200 - 300 mesh) with the eluent DCM:PE = 1:3. The receiving solution was rotated until no liquid flowed out, and the shown compound of formula L AA -91 (yield 54%) was obtained. The intermediate compound of formula L AA -91 was subjected to the following analytical tests:

[0137] HPLC purity: greater than 99.5%.

[0138]

[0139] Under a nitrogen protection system, compound of formula L AA-91 (1.0 eq) was dissolved clearly in the reaction system with THF. After heating up to an internal temperature of 55 °C - 57 °C, the heating was stopped, and copper acetate (1.0 eq) was added. Then, the THF solution containing tert-butyl nitrite (1.2 eq) was carefully dropped into the above system. There was heat and gas evolution in the system. After the dropping was completed, the reaction was kept warm for 2 h to end; the reaction solution was directly concentrated to dryness under reduced pressure, then DCM was added and refluxed to dissolve clearly. The solution was passed through a silica gel column. After collecting the column liquid, it was concentrated under reduced pressure to a remaining volume of about 100 ml, and then a solid precipitated. The temperature was lowered to below 20 °C and filtered, suction-dried, and dried to obtain Compound L A -91 (with a yield of 45%), and the intermediate Compound L A -91 was subjected to the following analysis and tests:

[0140] HPLC purity: greater than 99.5%.

[0141]

[0142] Under a nitrogen protection system, the ligand L A -91 (2.2 eq) and IrC1 3 ·3H 2 O (1.0 eq) were placed in the reaction system. A mixed solution of ethylene glycol monoethyl ether and pure water was added, and refluxed for 28 hours under nitrogen protection. Then it was cooled to room temperature, and a precipitate formed. The precipitate was filtered by suction, and rinsed successively with water, absolute ethanol, and petroleum ether, and then dried.

[0143] The bridged ligand II-91 in the form of a dark red powder was obtained (with a yield of 62%).

[0144]

[0145] Weigh the bridged ligand II-91 (1.0 eq), add anhydrous potassium carbonate (10.0 eq), then add ethylene glycol monoethyl ether to the system, displace nitrogen three times, and add Compound L B -91 (CAS: 872802-98-7, 3.0 eq) under nitrogen. Under nitrogen protection, reflux for 23 hours, cool down, filter by suction, wash with alcohol, and dry. Using dichloromethane as the solvent, column chromatography was carried out with neutral alumina. The filtrate was concentrated and a solid precipitated. Finally, the organophosphorus luminescent material shown as I-91 was obtained (with a yield of 31%). The organometallic compound I-91 was subjected to the following analysis and tests:

[0146] HPLC purity: greater than 99.5%;

[0147] Mass spectrometry: The measured value was 1040.47;

[0148] Elemental analysis: Calculated values are C, 68.12; H, 4.55; N, 2.69; O, 6.15. Measured values are C, 68.14; H, 4.53; N, 2.68; O, 6.16;

[0149] 1 H NMR (400 MHz, Chloroform-d) δ 9.52–9.46 (m, 1H), 8.66 (d, 2H), 8.61–8.54 (m, 1H), 8.37 (d, 2H), 7.94–7.86 (m, 2H), 7.83 (dd, 1H), 7.74 (dddd, 6H), 7.70 (dt, 1H), 7.58 (dd, 1H), 7.55–7.46 (m, 6H), 7.22 (dd, 1H), 5.65 (dd, 1H), 2.76 (pd, 1H), 2.48 (pd, 1H), 1.61–1.41 (m, 8H), 0.89 (t, 12H).

[0150] Synthesis Example 2

[0151] This synthesis example provides an organometallic compound I-608, that is, the compound numbered I-608. The specific synthesis steps are as follows:

[0152]

[0153] Under a nitrogen protection system, successively add compound 4-bromo-3-chlorophenanthrene (CAS: 2924419-31-6, 1.0 eq), cuprous bromide (1.0 eq), anhydrous sodium methyl mercaptide (1.0 eq), add them to DMF, then add water, N 2 Replace three times and N 2 Protect, heat and stir the reaction at 140 °C for 45 h. After the reaction is completed, cool to room temperature, pour the reaction solution into 3 times the volume of water, precipitate a solid, filter, dissolve the solid in DCM, filter the filtrate through a silica gel funnel, wash with DCM, and rotary evaporate the filtrate to obtain the crude product intermediate formula L AE -608 is directly used for the next reaction.

[0154]

[0155] Under a nitrogen protection system, successively add compound formula L AE -608 (1.0 eq), bis(pinacolato)diboron (1.0 eq), X-Phos (0.4 eq), palladium acetate (0.02 eq), potassium acetate and dioxane into the reaction system, N 2 Replace three times and N 2Protect, heat and stir overnight at 100 °C. After the reaction is completed, filter through diatomaceous earth and anhydrous magnesium sulfate, wash twice with ethyl acetate, collect the organic phase and concentrate under reduced pressure to obtain the crude product intermediate formula L AD -608 is directly used for the next step.

[0156]

[0157] Among them, L AC The synthesis method of the -608 compound is as shown in Synthesis Example 2 and will not be elaborated here.

[0158] Under a nitrogen protection system, weigh the compound of formula L AD -608 (1.0 eq), the compound of formula L AC -608 (1.0 eq), and anhydrous potassium carbonate (3.0 eq) into the reaction system, add toluene, absolute ethanol, pure water, and add Pd(PPh 3 ) 4 (0.02 eq) under nitrogen protection, reflux at 100 °C for 28 h under nitrogen protection. After the reaction is completed, separate the liquid, extract with ethyl acetate, wash three times with saturated brine, and concentrate under reduced pressure. Add 300 ml of dichloromethane to dissolve, subject the solution to column chromatography (200 - 300 mesh), and develop with the eluent DCM:PE = 1:3. Rotate the receiving solution until no liquid flows out to obtain the indicated compound of formula L AB -608 (yield 28%), and perform the following analysis and testing on the intermediate compound of formula L AB -608:

[0159] HPLC purity: greater than 99.5%.

[0160]

[0161] Under a nitrogen protection system, weigh the compound of formula L AB -608 (1.0 eq) and dissolve it in THF in the reaction system. After heating to an internal temperature of 55 °C - 57 °C, stop heating, add copper acetate (1.0 eq), and then carefully drop the THF solution containing tert-butyl nitrite (1.2 eq) into the above system. There is heat and gas evolution in the system. After the dropping is complete, keep warm for 2.0 h to end the reaction; directly concentrate the reaction solution to dryness under reduced pressure, then add DCM and reflux to dissolve clearly. Filter the solution through a silica gel column, collect the column liquid and concentrate under reduced pressure to a remaining volume of about 110 ml, and a solid will precipitate. Cool to below 20 °C and filter, drain, and dry to obtain the compound of formula L AA -608 (yield 53%), and perform the following analysis and testing on the intermediate compound of formula L AA -608:

[0162] HPLC purity: greater than 99.5%.

[0163]

[0164] Under a nitrogen protection system, weigh compound Formula L AA -608 (1.0 eq), neopentylboronic acid (CAS: 701261-35-0, 1.2 eq), and anhydrous potassium carbonate (3.0 eq) into the reaction system. Add toluene, absolute ethanol, and purified water. Under nitrogen protection, add Pd(PPh 3 ) 4 (0.02 eq). Reflux at 100 °C for 25 h under nitrogen protection. After the reaction is completed, separate the layers, extract with ethyl acetate, wash three times with saturated brine, and concentrate under reduced pressure. Dissolve in 250 ml of dichloromethane, and subject the solution to column chromatography (200 - 300 mesh, 1250 g) with the eluent DCM:PE = 1:3. Rotate the receiving solution until no liquid flows out to obtain the shown compound Formula L A -608 (yield 71%). Perform the following analytical tests on the intermediate compound Formula L A -608:

[0165] HPLC purity: greater than 99.5%.

[0166]

[0167] Under a nitrogen protection system, weigh ligand Formula L A -608 (2.5 eq) and IrC1 3 ·3H 2 O (1.0 eq) into the reaction system. Add a mixed solution of ethylene glycol monoethyl ether and purified water. Reflux for 28 hours under nitrogen protection, then cool to room temperature. Precipitates will form. Filter the precipitates by suction, and wash and dry them successively with water, absolute ethanol, and petroleum ether.

[0168] Obtain the bridged ligand II-608 as a dark red powder (yield 66%).

[0169]

[0170] Weigh the bridged ligand II-608 (1.0 eq), add anhydrous potassium carbonate (10 eq), then add ethylene glycol monoethyl ether to the system. Displace nitrogen three times. Under nitrogen, add the compound Formula L B -608 (CAS: 1821143-86-5, 2.5 eq). Under nitrogen protection, reflux for 23 hours, cool down, filter by suction, wash with alcohol, and dry. Use dichloromethane as the solvent and perform column chromatography on neutral alumina. Concentrate the filtrate to precipitate solids. Finally, obtain the organophosphorus luminescent material shown as I-608 (yield 41%). Perform the following analytical tests on the organometallic compound I-608:

[0171] HPLC purity: greater than 99.5%;

[0172] Mass spectrometry: the measured value is 1268.64;

[0173] Elemental analysis: calculated values are C, 69.11; H, 5.96; N, 2.21; O, 2.52; S, 5.05. Measured values are C, 69.10; H, 5.97; N, 2.22; O, 2.51; S, 5.06;

[0174] The 1H NMR spectrum of Compound I-608 is as Figure 1 shown.

[0175] The methods of other synthesis examples are similar to those of the aforementioned synthesis examples and will not be elaborated here.

[0176] The present invention also provides an organic electroluminescent device, which is made of the organic light-emitting material described above, and more specifically, is made of an organic light-emitting material of the compound with the chemical formula I structure.

[0177] Device Example 1

[0178] Device Fabrication

[0179] All devices of the examples are fabricated by high-vacuum (<10 -7 Torr) thermal evaporation method. The anode electrode is indium tin oxide (ITO). The cathode consists of Liq (lithium 8-hydroxyquinoline) and subsequently Al. All devices are immediately encapsulated with a glass cover sealed with epoxy resin in a nitrogen glove box (H 2 2O and O 2 <1 ppm) and a desiccant is incorporated inside the package. The organic stack of the device example consists of the following in sequence: the ITO surface, HT-10 of as the hole injection layer (HIL); HT-20 of as the hole transport layer (HTL); EBM of as the electron blocking layer (EBL); an emission layer (EML) of containing RH-01 as the red host and 3% of the emitter Compound I-1; and Liq (lithium 8-hydroxyquinoline) of doped with 35% of ET-10 as the electron transport layer (ETL). Table 1 shows the thickness and materials of the device layers.

[0180] Table 1: Materials and Thicknesses of Layers in the Device

[0181]

[0182]

[0183] Device Example 2 - 30 Referring to the method of the above Example 1, the only difference is that the doping material of Formula I - 1 compound is replaced with the corresponding compound in Table 2.

[0184] Device Comparative Example 1 - 4

[0185] An organic electroluminescent device was prepared according to the same method as in Example 1, except that the compounds of Comparative Example 1 - 4 structures were used to replace the doping compound I - 1 in Example 1.

[0186] HT - 10, HT - 20, EBM, RH - 01, Liq and the structures of Comparative Example 1 - 4 are as follows:

[0187]

[0188]

[0189] The driving voltage, luminous efficiency and lifetime of the organic electroluminescent devices obtained from the above device examples and device comparative examples were characterized at a brightness of 6000 (nits), and the test results are shown in Table 2 below.

[0190] Table 2

[0191]

[0192]

[0193]

[0194] As can be seen from Table 2, compared with the organic electroluminescent devices prepared by using the compounds provided in the comparative examples, for the organic electroluminescent devices prepared by using the compounds of the present invention as the doping materials of the light - emitting layer, the present invention selects specific ligand compounds, by fusing one or more benzene rings on the benzopyran or benzothiopyran ring, changes the intermolecular spatial configuration and three - dimensional structure, sets the molecular orientation, increases the planarity between molecules, adjusts the emission wavelength of the compound, changes the luminescence characteristics of its molecules, adjusts its HOMO and LUMO values, and enhances its electron adsorption ability. When the light - emitting material of the present invention matches the device structure of the present invention, the OLED device can have the advantages of long lifetime, high efficiency and low driving voltage.

[0195] The above examples only list the effect data of the devices made from a part of the structural formulas. This is a representative sampling test. Judging from the experimental data, the overall data does not vary much and can represent the effects of other unlisted structures.

[0196] The applicant declares that the organic electroluminescent material and the organic electroluminescent device of the present invention are illustrated by the above embodiments, 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 improvement to the present invention, the equivalent substitution of the raw materials selected for the present invention, the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. An organic electroluminescent material, characterized in that: The organic electroluminescent material has the following structure: A )2(L B ); The ligand L A and L B The structure is as follows: Formula L A and L B wherein R1, R2, R3, Ar1, Ar2, Ar3, Ar4 and Ar5 are independently selected from any one of -H, -D (deuterium), -T (tritium), -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, substituted or unsubstituted C2-C10 alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C20 aryl and substituted or unsubstituted 4-20 membered aromatic heterocyclic group; Wherein, m is an integer between 0 and 4; n is an integer between 0 and 2; q is an integer between 0 and 2; p is an integer between 0 and 3; r is an integer between 0 and 1; X is O or S; Ring H is a 4-8 membered aryl or heteroaryl group; Ring H is fused to any fused position of the ring with a dotted line; M is metal Ir; Formula L A and L B The hydrogen in may be undeuterated, partially deuterated, or fully deuterated.

2. The organic electroluminescent material according to claim 1, characterized in that: Ring H is a benzene ring.

3. The organic electroluminescent material according to claim 1, characterized in that: Formula LA has the specific structure shown below: Wherein, R1, R2, R3, Ar1, Ar2, Ar3, Ar4 and Ar5 are consistent with those defined in claim 1; m1, m2 and m3 are integers between 0 and 4, n1, n2, n3 and q are integers between 0 and 2, p is an integer between 0 and 3, and r is an integer between 0 and 1; Formula L A1 To L A3 The hydrogen atoms in may be undeuterated, partially deuterated, or fully deuterated.

4. The organic electroluminescent material according to claim 1, characterized in that: R1-R3, Ar1-Ar5 are independently selected from the following groups: -H, -D (deuterium), -T (tritium), -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge (Me) 3, -Si (Me) 3, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, thiolane, phenyl, biphenyl, terphenyl, naphthyl, Fluorenyl, phenanthryl, anthracenyl, triphenylene, naphthacene, fluoranthene, furanyl, thienyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, triazine, tetrazine, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, benzofuranyl, benzothienyl, isobenzofuranyl, dibenzofuranyl, dibenzothienyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, carbazolyl, phenanthridinyl.

5. The organic electroluminescent material according to claim 1, characterized in that: The substitution means that it can be substituted by one or at least two of the following groups: deuterium, tritium, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, thiolanyl, phenyl, biphenyl, terphenyl, naphthyl, fluorene phenyl, phenanthryl, anthracenyl, triphenylene, naphthacene, fluoranthene, furanyl, thienyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, triazine, tetrazine, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, carbazolyl or phenanthridinyl.

6. The organic electroluminescent material according to claim 1, characterized in that: The organometallic compound is selected from any one of the following compounds:

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode and a cathode and an organic thin film layer arranged between the anode and the cathode, the organic thin film layer comprises a light-emitting layer, the light-emitting layer comprises a main material and a doping material, and the doping material comprises the organic electroluminescent material as described in any one of claims 1-6.

8. The organic electroluminescent device according to claim 7, characterized in that: The organic thin film layer further includes at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

9. A display panel, characterized in that: The display panel comprises the organic electroluminescent device according to any one of claims 1 to 6.

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