Organic electroluminescent doping material and luminescent device

Abstract

According to the organic electroluminescent doping material and the luminescent device provided by the invention, a deuterium atom group is introduced to a specific position on a thiophene ring, and the molecular spacing and bond energy of the obtained compound are adjusted, so that the doping material with a specific atom structure is obtained; after the obtained organic compound with the specific atomic structure is applied to the organic electroluminescent device, the driving voltage is reduced, and the luminous efficiency of the device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescent materials, in particular, to an organic electroluminescent material doping and a light-emitting device, and more particularly to an organic electroluminescent material and a light-emitting device used as a doping material in an organic light-emitting diode and related electronic devices. Background Art

[0002] Organic semiconductor materials are new optoelectronic materials. Their large-scale origins can be traced back to the discovery of doped polyethylene with copper-level conductivity by Hideki Shirakawa, A. Heeger and A. McDiamid in 1977. Subsequently, in 1987, C. Tang et al. of Kodak invented the organic small molecule light-emitting diode (OLED). When voltage is applied to a device containing an OLED organic film, light is emitted. OLED is gradually gaining attention in flat panel display, lighting and backlight applications.

[0003] Since 2000, deuterium substitution strategy has been widely used in the optoelectronic materials industry. Due to the fast decay rate of OLED's luminescent materials, they have gradually become key materials that affect OLED display effects and service life. In OLED matrix materials, unstable heterocyclic carbon-hydrogen bonds can be exchanged for hydrogen / deuterium to extend the device's service life. Replacing unstable CH bonds in the main structure with CD bonds can increase the device's life by about 5 times without losing efficiency. Therefore, deuterated materials can not only improve the luminous efficiency and flexible display of OLED devices, but also have the characteristics of increased brightness and long half-life.

[0004] Deuterium is non-toxic, non-radioactive, and safe for the human body. More importantly, the CD bond is more stable than the CH bond (6-9 times). When deuterium atoms are introduced into the material, the spin-orbit coupling of the luminescent molecule will be enhanced, which is conducive to the generation of phosphorescence and increases its quantum efficiency. In addition, after the introduction of deuterium atoms, due to the shorter bond length and larger bond energy of the carbon-deuterium bond, the energy of the luminescent material will be reduced, thereby significantly enhancing the stability and life of the light-emitting device.

[0005] The paper “Isotope Effect of Host Material on Device Stability of Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes” points out that the green TADF-OLED based on the deuterated compound (PYD2Cz-d16) shows a more balanced carrier transport property than the undeuterated compound (PYD2Cz), thus achieving better device stability. 2When the LT95 is 134h, it is 1.7 times that of the compound (PYD2Cz). It can be seen that the device life can be improved by deuteration, but the improvement of driving voltage and device efficiency is unexpected.

[0006] The paper "Synthesis of all-deuterated tris(2-phenylpyridine) iridium for highly stable electrophosphorescence: the "deuterium effect"" also confirmed that the deuterium substitution of Ir(ppy)3 only slightly improved its photophysical properties, but had a significant impact on the stability and life of the device. 2 , the device based on Ir(ppy)3-D24 has a 20-fold higher current density and a lifetime 6 times longer than that of Ir(ppy)3. Through infrared spectrum comparison and DFT calculation, it can be proved that Ir(ppy)3-D24 has much lower internal energy than Ir(ppy)3, especially CD stretching and bending, which is the main factor in improving device stability and extending device lifetime, and is called the "deuterium effect".

[0007] In other words, it is currently known that deuterium substitution of OLED materials can improve the life of OLED devices, but how to improve the driving voltage and luminous efficiency of the device is a technical problem that urgently needs to be solved. Summary of the invention

[0008] In view of this, in order to solve the above problems, the present invention provides an organic electroluminescent doping material and a light-emitting device, by introducing a deuterium atom group at a specific position on the thiophene ring, adjusting the molecular distance and bond energy of the obtained compound, and obtaining a doping material with a specific atomic structure. After the obtained organic compound with a specific atomic structure is used in an organic electroluminescent device, the driving voltage is reduced and the luminous efficiency of the device is improved.

[0009] In order to achieve the above object, the present invention provides the following technical solutions: The present invention provides an organic electroluminescent doping material, which has a compound having a structure shown in formula I: M(L A )2(L B ); Wherein, M is metal; L A and L B All are ligands, L A and L B The general formula has the following structure:

[0010] wherein Ar1 and Ar2 are independently selected from -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, substituted or unsubstituted C2-C6 alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl, substituted or unsubstituted C6-C 10 Any one of an aryl group and a substituted or unsubstituted 4- to 8-membered aromatic heterocyclic group; R1, R2, R3, R4, R5, R6, R7, R8, and R9 are independently selected from -H, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, substituted or unsubstituted C2-C6 alkyl, substituted and unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 10 Any one of an aryl group and a substituted or unsubstituted 4- to 8-membered aromatic heterocyclic group; R 10 , R 11 , R 12 independently selected from -H, -D (deuterium), -T (tritium), -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, substituted or unsubstituted C2-C6 alkyl, substituted and unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 10 Any of an aryl group and a substituted or unsubstituted 4- to 8-membered aromatic heterocyclic group.

[0011] According to an embodiment of the present invention, M is preferably metal Ir.

[0012] According to an embodiment of the present invention, Ar1 and Ar2 are independently selected from -F, -CN, -CF3, -CH2F, -CHF2, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, terphenyl, fluorenyl, phenanthrenyl, triphenylene, furyl, benzofuranyl, benzothienyl, dibenzofuranyl, dibenzothienyl or any one of the following substituents: ; It is worth noting that in the present invention, * represents the connection position; "substituted" means that it can be replaced by -H, -D (deuterium), -T (tritium), -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, thiolane, phenyl, The benzothiophene group may be substituted with biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl, anthracenyl, indenyl, triphenylene, fluoranthene, furanyl, thienyl, imidazolyl, pyrazolyl, thiazolyl, pyridyl, pyrazinyl, pyrimidinyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothienyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, carbazolyl, or the like.

[0013] According to an embodiment of the present invention, R1-R9 is selected from the following groups: -H, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, thiolane, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl , phenanthryl, anthracenyl, indenyl, triphenylene, fluoranthene, furanyl, thienyl, imidazolyl, pyrazolyl, thiazolyl, pyridyl, pyrazinyl, pyrimidinyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothienyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, carbazolyl and the like.

[0014] According to an embodiment of the present invention, R 10 , R 11 , R 12independently selected from -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, tetrahydrofuran, pyrrolidine, thiolane, tetrahydropyran, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthrenyl, anthracenyl, indenyl, triphenylene, pyrenyl, naphthacene, peryl, chrysene, fused tetraphenyl, fluoranthenyl, furanyl, thienyl, pyrrolyl, imidazolyl, pyrrolyl, One or more of the following groups: oxazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl, phenoxazinyl, phenanthridinyl, benzodioxolyl and the like.

[0015] According to an embodiment of the present invention, the organic electroluminescent doping material is selected from any one of the following structures:

[0016] The present invention also provides a method for preparing an organic electroluminescent doping material. The preparation process of the organic electroluminescent doping material of the structural compound represented by formula I is as follows:

[0017] The definitions in the above formula are consistent with those mentioned above and will not be repeated here.

[0018] The present invention also provides an organic electroluminescent device, comprising a first electrode, a second electrode and an organic material layer located between the first electrode and the second electrode; the organic material layer can be divided into multiple regions. For example, the organic material layer comprises a hole transport region, a light-emitting layer, and an electron transport region; the light-emitting layer contains an organic electroluminescent doping material.

[0019] According to an embodiment of the present invention, the light-emitting layer may include a light-emitting dye (i.e., a dopant) that emits different wavelength spectra, and may also include a host material (Host) at the same time. The light-emitting layer may be a monochrome light-emitting layer that emits a single color such as red, green, and blue. A plurality of monochrome light-emitting layers of different colors may be arranged in a plane according to a pixel pattern, or may be stacked together to form a color light-emitting layer. When light-emitting layers of different colors are stacked together, they may be separated from each other or may be 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.

[0020] According to the embodiment of the present invention, the organic electroluminescent doping material can be different materials such as phosphorescent electroluminescent material, thermally activated delayed fluorescent luminescent material, etc. In an OLED device, a single luminescent technology can be used, or a combination of multiple different luminescent technologies can be used. These different luminescent materials classified by technology can emit light of the same color or different colors. The luminescent layer can use phosphorescent electroluminescent technology.

[0021] According to an embodiment of the present invention, the organic electroluminescent device includes an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, an electron transport layer, an electron injection layer and a cathode which are arranged in sequence.

[0022] According to an embodiment of the present invention, a substrate can be used below the first electrode or above the second electrode. The substrate is glass or a polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a thin film transistor (TFT) can also be provided on the substrate used as a display.

[0023] According to an embodiment of the present invention, the first electrode can be formed by sputtering or depositing the first electrode material on the substrate. When the first electrode is used as an anode, an oxide transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO) and any combination thereof can be used.

[0024] According to an embodiment of the present invention, the anode material may also be selected from materials other than the listed anode materials that facilitate hole injection and combinations thereof, including known materials suitable for the anode.

[0025] According to an embodiment of the present invention, when the first electrode is used 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) and any combination thereof can be used.

[0026] In addition to the cathode materials listed above, the cathode material may also be a material that facilitates electron injection and a combination thereof, including known materials suitable for the cathode.

[0027] According to an embodiment of the present invention, the organic material layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, etc.

[0028] According to an embodiment of the present invention, the compound used as the organic material layer may be an organic small molecule, an organic macromolecule, a polymer, and a combination thereof.

[0029] According to an embodiment of the present invention, 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 with only one compound and a single-layer hole transport layer containing multiple compounds.

[0030] According to an embodiment of the present invention, the hole transport region may also be a multi-layer structure including at least one layer of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0031] According to an embodiment of the present invention, the material of the hole transport layer may be selected from phthalocyanine derivatives, such as CuPc, conductive polymers, and the like.

[0032] According to an embodiment of the present invention, the material of the hole transport layer may be selected from polymers containing a conductive dopant.

[0033] For example, polyphenylene ethylene, polyaniline / dodecylbenzene sulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrene sulfonate) (PEDOT / PSS), polyaniline / camphor sulfonic acid (Pani / CSA), polyaniline / poly(4-styrene sulfonate) (Pani / PSS), aromatic amine derivatives such as the compounds shown in HT-1 to HT-34 below; or any combination thereof.

[0035] But it is not limited to the above materials.

[0036] According to an embodiment of the present invention, the hole injection layer is located between the anode and the hole transport layer.

[0037] According to an embodiment of the present invention, the hole injection layer may be a single compound material or a combination of multiple compounds.

[0038] For example, the hole injection layer can be made from one or more compounds of the above HT-1 to HT-34, or from one or more compounds of the following HI-1 to HI-3; or from one or more compounds of HT-1 to HT-34 doped with one or more compounds of the following HI-1 to HI-3:

[0039] But it is not limited to the above materials.

[0040] The OLED organic material layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may 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 may also be a multilayer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0041] 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 ET-1 to ET-57 listed below.

[0042]

[0044] But it is not limited to the above materials.

[0045] According to an embodiment of the present invention, the organic electroluminescent device further comprises an electron injection layer located between the electron transport layer and the cathode.

[0046] According to an embodiment of the present invention, the material of the electron injection layer is selected from one or more of LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li and Ca.

[0047] This application has the following beneficial effects: 1) The present invention provides an organic electroluminescent doping material and a light-emitting device. A deuterium atom group is introduced at a specific position on a thiophene ring, and the molecular spacing and bond energy of the resulting compound are adjusted to obtain a doping material with a specific atomic structure. The obtained doping material with a specific atomic structure is applied to an organic electroluminescent device, which can significantly reduce the driving voltage and improve the luminous efficiency of the device.

[0048] 2) The organic electroluminescent material prepared by the present invention is used for the light-emitting layer of an organic electroluminescent device. Since the light-emitting material is a structure composed of a specific doping material and a main material, and is designed in conjunction with other layer materials, it can effectively reduce the starting and ending voltage of the organic electroluminescent device and improve the efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The compound L in the embodiment of the present invention is AF -1 H NMR spectrum. DETAILED DESCRIPTION

[0050] The following will be clearly and completely described in conjunction with the technical solutions of the synthesis examples and embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0051] Synthesis example 1 This synthesis example provides an organometallic compound Ⅰ-1, and the specific synthesis steps are as follows: 1)

[0052] Under nitrogen protection system, weigh compound 1-bromo-2-chloro-4-iodo-3-methylbenzene (CAS: 1000573-57-8) (1700mmol), deuterated benzene (170000mmol), trifluoromethanesulfonic acid (5100mmol) and put into the reaction system, reflux for 18h under nitrogen protection, after the reaction is completed, add heavy water to quench, extract with ethyl acetate, wash three times with saturated brine, concentrate under reduced pressure, column chromatography (200-300 mesh, 6000g) with developing agent DCM:PE=1:10, rotate the receiving solution until no liquid flows out, and obtain formula L AF -1 (461.19 g, yield 82%).

[0053] The intermediate formula L AF -1 The compounds shown in Figure 1 were subjected to the following analytical tests: HPLC purity: greater than 99.5%; mass spectrometry: test value is 330.92; 2)

[0054] Under nitrogen protection system, weigh formula L AF -1 (1350mmol), neopentylboric acid (CAS:701261-35-0) (1350mmo1), anhydrous potassium carbonate (4050mmol) were put into the reaction system, 3600ml of toluene, 1800ml of anhydrous ethanol, 1800ml of purified water were added, Pd(PPh3)4 (27mmol) was added under nitrogen protection, and refluxed at 100°C for 22h under nitrogen protection.

[0055] After the reaction is completed, the liquid is separated, extracted with ethyl acetate, washed three times with saturated brine, and concentrated under reduced pressure. 600 ml of dichloromethane is added to dissolve, and the solution is subjected to column chromatography (200-300 mesh, 2900 g) with a developing solvent of DCM:PE=1:5. The receiving solution is vortexed until no liquid flows out to obtain formula L AE -1 shown in the compound (129.95g, yield 35%), the intermediate compound formula L AE -1 Carry out the following analysis tests: HPLC purity: greater than 99.5%; mass spectrum: test value is 275.18. 3)

[0057] Under nitrogen protection system, compound formula L AE -1 (470mmol), biboric acid pinacol ester (470mmol), X-Phos (94mmol), palladium acetate (9.4mmol), potassium acetate (1410mmol) and dioxane (2850mL) were added to the reaction system, replaced with N2 three times and protected with N2, heated and stirred at 100°C overnight. After the reaction was completed, diatomaceous earth and anhydrous magnesium sulfate were filtered, washed with ethyl acetate twice, and the organic phase was collected and concentrated under reduced pressure to obtain a crude product intermediate of formula L AD The compound shown in -1 was directly used in the next step. 4)

[0059] Under nitrogen protection system, compound formula L AD-1 (470mmol), cuprous bromide (470mmmol), anhydrous sodium methylthiolate (1410mmol), added to DMF (1850mL), then added water (185mL), N2 replaced three times and N2 protected, heated and stirred at 140°C for 41h. After the reaction was completed, cooled to room temperature, the reaction solution was poured into 3 times the volume of water, solid precipitated, filtered, the solid was dissolved with DCM, the filtrate was passed through a silica gel funnel, DCM was rinsed, and the filtrate was dried to obtain a crude product intermediate of formula L AC The compound shown in -1 was directly used in the next reaction. 5)

[0061] Under nitrogen protection system, weigh compound formula L AC -1(470mmol), 2-chloro-3-amino-4-bromopyridine (CAS: 1354021-09-2) (470mmo1), anhydrous potassium carbonate (1410mmol) were put into the reaction system, 3100ml toluene, 1550mL anhydrous ethanol, 1550mL purified water were added, Pd(PPh3)4(9.4mmol) was added under nitrogen protection, refluxed at 100℃ for 23h under nitrogen protection, after the reaction was completed, liquid was separated, extracted with ethyl acetate, washed with saturated brine three times, and concentrated under reduced pressure. 750ml dichloromethane was added to dissolve, the solution was column chromatographed (200-300 mesh, 2350g) with developing agent DCM:PE=1:2, and the receiving liquid was vortexed until no liquid flowed out to obtain formula L AB -1 shown in the compound (67.89g, yield 43%), the intermediate compound formula L AB -1 Carry out the following analysis tests: HPLC purity: greater than 99.5%; mass spectrum: test value is 335.96. 6)

[0063] Under nitrogen protection system, weigh compound formula L AB -1 (200mmol) was dissolved in THF (810mL) in the reaction system. After the temperature reached 55°C to 57°C, the heating was stopped, copper acetate (200mmol) was added, and then 105mL THF solution containing tert-butyl nitrite (240mmol) was carefully dripped into the above system. The system released heat and gas. After the addition was completed, the temperature was kept for 1.5h to complete the reaction. The reaction solution was directly concentrated to dryness under reduced pressure, and then DCM (1300mL) was added to reflux and dissolve until it became clear. The solution was passed through a silica gel column. After the column liquid was collected, it was concentrated under reduced pressure to a remaining volume of about 90ml. After solid precipitation, the temperature was lowered to below 20°C, filtered, drained, and dried to obtain compound L AA-1 (25.00 g, yield 41%), the intermediate compound formula L AA -1 Carry out the following analysis tests: HPLC purity: greater than 99.5%; The mass spectrometry test value was 304.94. 7)

[0065] Under nitrogen protection system, weigh compound formula L AA -1 (80mmol), [4-(tert-butyl) naphthalene] -2-boronic acid pinacol ester (CAS: 2217657-10-6) (96mmo1), anhydrous potassium carbonate (240mmol) were put into the reaction system, 1200ml toluene, 600mL anhydrous ethanol, 600mL purified water were added, Pd (PPh3) 4 (1.6mmol) was added under nitrogen protection, refluxed at 100 ° C for 23h under nitrogen protection, after the reaction was completed, the liquid was separated, extracted with ethyl acetate, washed with saturated brine three times, and concentrated under reduced pressure. 185ml of dichloromethane was added to dissolve, the solution was column chromatographed (200-300 mesh, 700g) with the developing agent DCM: PE = 1:4, and the receiving liquid was vortexed until no liquid flowed out to obtain formula L A -1 shown in the compound (22.79g, yield 63%), the intermediate compound formula L A -1 Carry out the following analysis tests: HPLC purity: greater than 99.5%; Mass spectrum: test value is 452.38; Elemental analysis: Calculated values ​​are C, 82.25; H, 7.57; N, 3.09; S, 7.08. Measured values ​​are C, 82.26; H, 7.56; N, 3.08; S, 7.09. 8)

[0067] Under nitrogen protection system, weigh the ligand formula L A -1 (52.8mmol), IrC13·3H2O (22mmol) were put into the reaction system, and a mixed solution of 480ml of ethylene glycol ethyl ether and 160ml of pure water was added. The mixture was refluxed for 30 hours under nitrogen protection, and then cooled to room temperature. A precipitate was precipitated. The precipitate was filtered, washed with water, anhydrous ethanol and petroleum ether in turn, and dried to obtain a dark red powder of the bridged ligand Ⅱ-1 (15.67g, yield 63%). 9)

[0069] Weigh the bridged ligand II-1 (5.5 mmol), add anhydrous potassium carbonate (55 mmol), then add 230 ml of ethylene glycol ether to the system, replace nitrogen three times, and add formula L under nitrogen. B -1 compound (CAS: 872802-98-7) (16.5mmol), reflux for 28 hours under nitrogen protection, cool, filter, wash with alcohol, and dry. Use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate to precipitate solid, and finally obtain the organic phosphorus luminescent material shown in Ⅰ-1 (4.17g, its yield is 29%).

[0070] The obtained organometallic compound having the structure shown in Formula I-1 was analyzed and tested: HPLC purity: greater than 99.5%; Mass spectrum: test value is 1306.72; Elemental analysis: Calculated values: C, 68.93; H, 6.86; N, 2.14; O, 2.45; S, 4.91. Test values: C, 68.91; H, 6.88; N, 2.15; O, 2.46; S, 4.90; 1 H NMR (400 MHz, Chloroform-d) δ 8.87 (d, 2H), 8.34 (dd, 2H), 8.01 –7.94 (m, 2H), 7.81 (d, 2H), 7.70 (d, 2H), 7.54 (s, 2H), 7.45 (td, 2H), 7.37(td, 2H), 5.65 (dd, 1H), 2.76 (pd, 1H), 2.62 (s, 4H), 2.48 (pd, 1H), 2.31 (s,6H), 1.63 – 1.51 (m, 4H), 1.50 – 1.44 (m, 4H), 1.43 (d, 18H), 1.00 (d, 18H),0.89 (t, 12H).

[0071] Synthesis example 2 This synthesis example provides an organometallic compound I-193, i.e., a compound numbered I-193. The specific synthesis steps are as follows:

[0072] Among them, the synthesis method of Formula II-193 is shown in Synthesis Example 1 and will not be repeated here.

[0073] Weigh the bridged ligand II-193 (5.5 mmol), add anhydrous potassium carbonate (55 mmol), add 240 ml of ethylene glycol ether to the system, replace nitrogen three times, and add formula L under nitrogen. B -193 compound (CAS: 1821143-86-5) (22.0mmol), reflux for 28 hours under nitrogen protection, cool, filter, wash with alcohol, and dry. Use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate and precipitate solid, and finally obtain the organic metal compound shown in Ⅰ-193 (3.79g, its yield is 27%). The organic metal compound Ⅰ-193 is subjected to the following analytical tests: HPLC purity: greater than 99.5%; Mass spectrum: test value is 1362.75; Elemental analysis: calculated values ​​are C, 69.62; H, 7.17; N, 2.06; O, 2.35; S, 4.70. Test values ​​are C, 69.63; H, 7.16; N, 2.07; O, 2.34; S, 4.71; 1 H NMR (400 MHz, Chloroform-d) δ 8.87 (d, 2H), 8.34 (dd, 2H), 8.01 –7.94 (m, 2H), 7.81 (d, 2H), 7.70 (d, 2H), 7.54 (s, 2H), 7.45 (td, 2H), 7.37(td, 2H), 5.61 (dd, 1H), 2.66 (td, 1H), 2.62 (s, 4H), 2.31 (s, 6H), 2.14(ddd, 1H), 2.00 (dq, 2H), 1.85 (dq, 2H), 1.45 – 1.40 (m, 18H), 1.04 – 0.97(m, 18H), 0.96 – 0.87 (m, 24H).

[0074] The present invention also provides an organic electroluminescent device, which contains the organic electroluminescent doping material of the present invention, more specifically, an organic electroluminescent doping material containing a compound having a structure shown in Chemical Formula I.

[0075] In order to further describe the present invention, more specific embodiments are listed below.

[0076] Device Example 1 All the device devices of the embodiments were placed in a high vacuum (<10 7The device was fabricated by thermal evaporation of 1000 Å of 2000 Å ...

[0077] The organic stack of the device example is as follows in order: ITO surface, 100 angstroms of HT-16 as hole injection layer (HIL); 400 angstroms of HT-16 as hole transport layer (HTL); 50 angstroms of EBM as electron blocking layer (EBL); 400 angstroms of emission layer (EML) containing RH-01 as red host and 3% of emitter formula I-1 compound; 350 angstroms of Liq (8-hydroxyquinoline lithium) doped with 35% ET-16 as electron transport layer (ETL). Table 2 shows the thickness and materials of the device layers.

[0078] Table 2: Device layer materials and thicknesses

[0079] The structure is as follows:

[0080] Device Examples 2-12 The preparation method is the same as that of the above-mentioned Example 1, except that the doping material Ⅰ-1 is replaced by Ⅰ-5, Ⅰ-65, Ⅰ-119, Ⅰ-142, Ⅰ-169, Ⅰ-193, Ⅰ-197, Ⅰ-213, Ⅰ-245, Ⅰ-281, Ⅰ-293.

[0081] Device Comparison Examples 1-4 The method for preparing the organic electroluminescent device is the same as that in the above Example 1, except that the compound represented by the doping material formula I-1 in Example 1 is replaced by the structural compounds of Comparative Examples 1 to 4.

[0082] The compounds obtained in Comparative Examples 1-4 are as follows:

[0083] The driving voltage, luminous efficiency and life of the organic electroluminescent devices obtained in the above device embodiments and device comparative examples were characterized at a brightness of 6000 (nits). The test results are shown in Table 3 below: Table 3

[0084] It can be seen from Table 3 that the organic electroluminescent doping material compound prepared by the present invention is used as a light-emitting layer and applied to the doping material in the organic electroluminescent device. Compared with the organic electroluminescent device prepared in the comparative example, since the present invention selects a specific ligand compound, introduces a deuterium atom group on the thiophene ring, changes the spatial configuration, intermolecular distance and bond energy, sets the molecular orientation, and matches the device structure of the present invention, although the life span is not significantly improved compared with the comparative example, it can be clearly seen that the OLED device prepared by the present invention has the advantages of high efficiency, low driving voltage, etc.

[0085] The above embodiments only list the effect data of devices made of a part of the structural formulas. This is a representative sampling test. According to the experimental data, the overall data is not much different and can represent the effects of other unlisted structures.

[0086] It will be apparent to those skilled in the art that many modifications and variations of the present invention are possible without departing from the spirit and scope of the present invention. It is therefore contemplated that the present invention covers modifications and variations of the present invention provided within the scope of the appended claims and their equivalents.

[0087] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic electroluminescent doping material, characterized in that: Containing compound M (L A )2 (L B ); Wherein, M is metal; L A and L B All are ligands, L A and L B A compound having the following structural formula: Ar1 and Ar2 are independently selected from -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, substituted or unsubstituted C2-C6 alkyl, substituted and unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 10 Any one of an aryl group and a substituted or unsubstituted 4-8 membered aromatic heterocyclic group; R1, R2, R3, R4, R5, R6, R7, R8, and R9 are independently selected from -H, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, substituted or unsubstituted C2-C6 alkyl, substituted and unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 10 Any one of an aryl group and a substituted or unsubstituted 4- to 8-membered aromatic heterocyclic group; R 10 , R 11 , R 12 independently selected from -H, -D, -T, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, substituted or unsubstituted C2-C6 alkyl, substituted and unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 10 Any one of an aryl group and a substituted or unsubstituted 4- to 8-membered aromatic heterocyclic group; The term "substituted" refers to being able to be replaced by -H, -D, -T, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, thiolane, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, , phenanthryl, anthracenyl, indenyl, triphenylene, fluoranthene, furanyl, thienyl, imidazolyl, pyrazolyl, thiazolyl, pyridyl, pyrazinyl, pyrimidinyl, benzofuranyl, benzothienyl, isobenzofuranyl, dibenzofuranyl, dibenzothienyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl, and carbazolyl groups.

2. The organic electroluminescent doping material according to claim 1, characterized in that: The M is metal Ir.

3. The organic electroluminescent doping material according to claim 1, characterized in that: Ar1 and Ar2 are independently selected from -F, -CN, -CF3, -CH2F, -CHF2, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, terphenyl, fluorenyl, phenanthryl, triphenylene, furyl, benzofuranyl, benzothienyl, dibenzofuranyl, dibenzothienyl or any one of the following substituents: Among them, * represents the connection position.

4. The organic electroluminescent doping material according to claim 1, characterized in that: The R1-R9 are independently selected from the following groups: -H, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, -Ge(Me)3, -Si(Me)3, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, thiolane, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, One or more of phenanthryl, anthracenyl, indenyl, triphenylene, fluoranthene, furanyl, thienyl, imidazolyl, pyrazolyl, thiazolyl, pyridyl, pyrazinyl, pyrimidinyl, benzofuranyl, benzothienyl, isobenzofuranyl, dibenzofuranyl, dibenzothienyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, quinazolinyl, quinoxalinyl and carbazolyl.

5. The organic electroluminescent doping material according to claim 1, characterized in that: The R 10 , R 11 , R 12 independently selected from -H, -D, -T, -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, tetrahydrofuran, pyrrolidine, thiolane, tetrahydropyran, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthrenyl, anthracenyl, indenyl, triphenylene, pyrenyl, naphthacene, peryl, chrysene, fused tetraphenyl, fluoranthenyl, furanyl, thienyl, pyrrolyl, imidazolyl , pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl, phenoxazinyl, phenanthridinyl, and benzodioxolyl.

6. The organic electroluminescent doping material according to claim 1, characterized in that: Select one of the following structures: The organic electroluminescent doping material is selected from any one of the following structures: 。 7. An organic electroluminescent device, comprising a first electrode, a second electrode and an organic material layer located between the first electrode and the second electrode; the organic material layer comprises a hole transport region, a light-emitting layer and an electron transport region; characterized in that: The light-emitting layer contains the organic electroluminescent doping material according to any one of claims 1 to 6.

8. The organic electroluminescent device according to claim 7, characterized in that: The hole transport region is a hole transport layer of a single-layer structure, and the hole transport layer of the single-layer structure is a single-layer hole transport layer containing only one compound or a single-layer hole transport layer containing multiple compounds; Alternatively, the hole transport region includes a multilayer structure of at least one layer of a hole injection layer, a hole transport layer, and an electron blocking layer.

9. The organic electroluminescent device according to claim 7, characterized in that: The electron transport region is an electron transport layer of a single-layer structure, and the electron transport layer of the single-layer structure is a single-layer electron transport layer containing only one compound or a single-layer electron transport layer containing multiple compounds; Alternatively, the electron transport region includes a multilayer structure of at least one layer of an electron injection layer, an electron transport layer, and a hole blocking layer.

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