Triazole carbene iridium complex capable of emitting dark blue light, synthetic method thereof and application of triazole carbene iridium complex in electroluminescent device

Abstract

The invention relates to the technical field of organic phosphorescent light-emitting diodes, and discloses a triazole carbene iridium complex capable of emitting dark blue light, a synthetic method of the triazole carbene iridium complex and application of the triazole carbene iridium complex in an electroluminescent device. The invention relates to a triazole carbene iridium complex capable of emitting dark blue light, the structural general formula of the triazole carbene iridium complex is as follows: # imgabs0 #, in which R3 to R10 are independently selected from any one of hydrogen, deuterium, alkyl, aryl, halogen group, cyano, acyl, amino, substituted amino, hydroxyl, sulfydryl, alkoxy, alkylthio, silyl, fluorine-containing alkyl, ester group and amide group; r1 to R2 are independently selected from any one of a hydrogen group, a deuterium group, an alkyl group and an aromatic group. The triazole carbene iridium complex capable of emitting dark blue light, provided by the invention, contains a gem-dimethyl-1, 2, 4-triazole carbene ligand. The synthesis yield of the carbene ligands is very high, and the carbene ligands can be produced on a large scale without column chromatography separation. And the stability of the complex is remarkably enhanced by the gem-dimethyl group.

Description

Technical Field

[0001] The invention relates to the technical field of organic phosphorescent light-emitting diodes, and in particular to a type of deep-blue light-emitting triazole carbene iridium complex, a synthesis method thereof, and an application thereof in electroluminescent devices. Background Art

[0002] In the field of organic phosphorescent light-emitting diode (PHOLED) technology, developing high-efficiency pure blue or deep blue light-emitting devices is one of the key challenges to achieve high-quality display screens. Therefore, the study of pure blue or deep blue phosphorescent iridium (III) complexes is a hot research topic in this field.

[0003] At present, the synthesis of deep blue phosphorescent iridium (III) complexes faces multiple challenges, including the need for complex processes such as transition metal catalysis, column chromatography separation, and high-temperature reaction during the ligand synthesis process, as well as the need to consume expensive Ag2O in the synthesis of the complex. On the other hand, the emission light of most iridium (III) complexes tends to be sky blue (such as FIrpic), which cannot meet the requirements of full-color display of organic phosphorescent light-emitting diodes.

[0004] Therefore, the prior art needs to be further improved and enhanced. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a triazole carbene iridium complex emitting deep blue light and a preparation method thereof, and an organic phosphorescent light-emitting diode, aiming to solve the problems of requiring transition metal catalysis, column chromatography separation and the use of Ag2O in the synthesis process of deep blue phosphorescent iridium (III) complexes.

[0006] The above object of the present invention is achieved by the following technical solution: a triazole carbene iridium complex emitting deep blue light, the general structural formula of which is as follows:

[0007]

[0008] Among them, R3~R10 are independently selected from any one of hydrogen, deuterium, alkyl, aromatic, halogen, cyano, acyl, amino and substituted amino, hydroxyl, thiol, alkoxy, alkylthio, silane, fluorine-containing hydrocarbon, ester and amide; R1~R2 are independently selected from any one of hydrogen, deuterium, alkyl and aromatic.

[0009] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0010] As a preferred technical solution, the deep blue light emitting triazole carbene iridium complex, wherein R1 to R2 are independently selected from deuterated alkyl or deuterated aromatic groups; R3 to R10 are independently selected from any one of deuterated alkyl, deuterated aromatic groups, deuterated acyl groups, deuterated amino groups and deuterated substituted amino groups, deuterated hydroxyl groups, deuterated thiol groups, deuterated alkoxy groups, deuterated alkylthio groups, deuterated silanyl groups, deuterated fluorinated hydrocarbon groups, deuterated ester groups and deuterated amide groups.

[0011] As a preferred technical solution, the triazole carbene iridium complex emitting deep blue light, wherein the ligand structural formula constituting the carbene iridium phosphorescent complex is:

[0012]

[0013] As a preferred technical solution, the deep blue light emitting triazole carbene iridium complex, wherein the carbene iridium phosphorescent complex includes a meridional structure and a planar structure.

[0014] As a preferred technical solution, the deep blue light emitting triazole carbene iridium complex, wherein the deep blue light emitting triazole carbene iridium complex comprises:

[0015]

[0016]

[0017]

[0018]

[0019]

[0020] In a second aspect, a method for preparing the deep blue light emitting triazole carbene iridium complex according to the first aspect, comprising:

[0021] The ligand, (1,5-cyclooctadiene)iridium(I) chloride dimer and a base are mixed, a first solvent is added, and Ag2O is not used, and the mixture is refluxed at 100 to 180° C. to obtain a suspension;

[0022] filtering and eluting the suspension to obtain the deep blue light emitting triazole carbene iridium complex;

[0023] The general structural formula of the ligand is:

[0024] Wherein X is tetrafluoroborate ion, hexafluorophosphate ion, hexafluorosilicate ion, hexafluoroaluminate ion, perchlorate ion, hexafluoroarsenate ion, trifluoromethanesulfonate ion, methanesulfonate ion, trifluoroacetate ion, acetylacetonate ion, fluoride ion, chloride ion, bromide ion, iodide ion or the like.

[0025] As a preferred technical solution, the preparation method of the deep blue light emitting triazole carbene iridium complex, wherein the base includes potassium carbonate, sodium carbonate, lithium carbonate, cesium carbonate, potassium acetate, sodium acetate, lithium acetate, cesium acetate, potassium tert-butoxide, sodium tert-butoxide, lithium tert-butoxide, cesium tert-butoxide, triethylamine, trimethylamine, 1,8-diazabicyclo (5.4.0) undec-7-ene, triethylammonium, 6-cyanomethyl-2,2-dimethyl-1,3-dioxolane-acetic acid tert-butyl ester and The first solvent includes: chlorobenzene, dichlorobenzene, trichlorobenzene, benzene, toluene, disubstituted toluene, trisubstituted toluene, ethylbenzene, fluorobenzene, trifluorobenzene, dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 2-methyltetrahydrofuran, 1,4-dioxane, NMP, cyclopentane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, C5 to C 14 Alkanes, methanol, ethanol, butanol, tri-amyl alcohol, tert-butanol, glycerol and its substitutes, ethylene glycol, polyethylene glycol and its substitutes.

[0026] As a preferred technical solution, the method for preparing the deep blue light emitting triazole carbene iridium complex is defined as follows: the equivalent of the (1,5-cyclooctadiene)iridium (I) chloride dimer is defined as 1, the equivalent of the ligand is 6 to 10, and the equivalent of the base is 6 to 10.

[0027] As a preferred technical solution, the method for preparing the deep blue light emitting triazole carbene iridium complex, wherein the method for preparing the ligand comprises:

[0028] Mixing raw material A, a second solvent and trimethyloxonium tetrafluoroboric acid, and reacting at -20 to 80° C. to obtain a reaction mixture;

[0029] The reaction mixture is mixed with phenylhydrazine or phenylhydrazine with a substituent, and the second solvent is removed after the reaction, wherein the reaction process does not require transition metal catalysis and does not require column chromatography separation to obtain the ligand;

[0030] The structural formula of the raw material A is:

[0031] As a preferred technical solution, the preparation method of the triazole carbene iridium complex emitting deep blue light, wherein the second solvent is an aprotic solvent including: chlorobenzene, dichlorobenzene, trichlorobenzene, benzene, toluene, disubstituted toluene, trisubstituted toluene, ethylbenzene, fluorobenzene, trifluorobenzene, dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 2-methyltetrahydrofuran, 1,4-dioxane, NMP, cyclopentane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, C5 to C 14 alkane; defining the equivalent of the raw material A to be 1, the equivalent of the trimethyloxonium tetrafluoroboric acid to be 0.8 to 3; the equivalent of the phenylhydrazine or substituted phenylhydrazine to be 0.8 to 3.

[0032] In a third aspect, a deep blue light emitting triazole carbene iridium complex as described above is used in an electroluminescent device.

[0033] Beneficial effects: Compared with the prior art, the deep blue light emitting triazole carbene iridium complex provided by the present invention contains geminal dimethyl-1,2,4-triazole carbene ligand. The synthesis yield of this type of carbene ligand is very high, and it can be produced on a large scale without column chromatography separation. And the geminal dimethyl group significantly enhances the stability of the complex. The large sterically hindered electron donor tert-butyl group contained in these carbene iridium phosphorescent complexes causes their photoluminescence peak to red-shift and increases their photoluminescence quantum yield (PLQYs). The provided carbene iridium phosphorescent complex shows great potential as a blue phosphor and can present a maximum emission peak at around 435 nanometers. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The invention provides a synthesis route of a deep blue light emitting triazole carbene iridium complex;

[0035] Figure 2 It is a structural diagram of fac-TzDm provided by the present invention;

[0036] Figure 3 It is a structural diagram of fac-TzDm-t provided by the present invention;

[0037] Figure 4 is a structural diagram of mer-TzDm provided by the present invention;

[0038] Figure 5 is a structural diagram of mer-TzDm-t provided by the present invention;

[0039] Fig. 6A is the UV-visible absorption spectrum of the triazole carbene iridium complex; 6B is the emission spectrum of the triazole carbene iridium complex;

[0040] Figure 7 is a schematic diagram of the structure of an electroluminescent device;

[0041] Figure 8 Performances of mer-TzDm-based OLED device D4 and mer-TzDm-t-based OLED device D6, including (a) electroluminescence spectrum, (b) current density-voltage-luminance (JVL) curve, (c) external quantum efficiency-luminance (EQE-L) curve, and (d) current efficiency-luminance-power efficiency (CE-L-PE) curve. DETAILED DESCRIPTION

[0042] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0045] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0046] The present invention provides a deep blue light emitting triazole carbene iridium complex, the general structural formula of which is as follows:

[0047] By introducing geminal dimethyl groups at the benzylic position of the ligand, not only can its stability be enhanced, but also its rigidity can be effectively increased and non-radiative transitions can be reduced. This will improve the luminescence efficiency of the iridium complex while maintaining its luminescence properties. At the same time, the ligands in the carbene iridium phosphorescent complex can also be easily introduced with various functional groups and modified as needed. They can be synthesized quickly and on a large scale without transition metal catalysis or column chromatography separation, providing great potential for the subsequent large-scale production of such iridium (III) complexes.

[0048] Based on the same inventive concept, Figure 1 As shown, the present invention also provides a preparation flow chart of a deep blue light emitting triazole carbene iridium complex.

[0049] Exemplarily, (1) Synthesis of ligand:

[0050] In a well-dried 150 mL round-bottom flask were added 1 (1.0 g, 6.21 mmol, 1.0 eq) and dichloromethane (40 mL). Trimethyloxonium tetrafluoroborate (1.01 g, 6.83 mmol, 1.1 eq) was added and the reaction mixture was stirred at 25°C for 18 hours. Phenylhydrazine or substituted phenylhydrazine (7.45 mmol, 1.2 eq) was added to the resulting solution and the reaction was stirred for 48 hours. The solvent was evaporated to dryness under reduced pressure and the product was used without further purification. Methanol (7 mL) and triethyl orthoformate (21 mL) were added and the reaction mixture was stirred at 100°C overnight. After the system was cooled, the product precipitated from the system to give the desired compound as a pale yellow / light yellow powder (4-1 yield was 75% and 4-2 yield was 78%). A purer product 4 can be obtained by recrystallization from hot methanol.

[0051] (2) Synthesis of complexes mer-TzDm and fac-TzDm

[0052] Under N2 atmosphere, the corresponding ligand obtained above (0.447 mmol), chloro(1,5-cyclooctadiene)iridium(I) dimer [Ir(COD)Cl]2 (0.074 mmol) and sodium acetate (0.447 mmol) were mixed in 8 ml of degassed chlorobenzene and refluxed at 130°C for 12 hours to obtain a light yellow suspension. After cooling to room temperature, the reaction mixture was filtered through diatomaceous earth, and the filtrate was decompressed to remove the solvent. Rapid column chromatography was performed using dichloromethane as the eluent, and after separation, dichloromethane and n-hexane were used again for crystallization to obtain white solid mer-TzDm; 65 mg was obtained. At the same time, fac-TzDm was also obtained (the amount was about 1 / 10 of mer-TzDm, and dichloromethane and ethanol were used for crystallization). The yield (mer+fac) was 50%.

[0053] (3) Synthesis of the complexes mer-TzDm-t and fac-TzDm-t

[0054] Under N2 atmosphere, the corresponding ligand (0.447 mmol), iridium (I) chloride (1,5-cyclooctadiene) dimer [Ir(COD)Cl]2 (0.074 mmol) and sodium acetate (0.447 mmol) were mixed, 8 ml of degassed chlorobenzene was added, and refluxed at 130°C for 12 hours to obtain a light yellow suspension. After cooling to room temperature, it was filtered through diatomaceous earth, and the filtrate was evaporated under reduced pressure. By using dichloromethane and n-hexane (1:2) as eluents for flash chromatography column chromatography, and then recrystallization using dichloromethane and hexane, a white solid mer-TzDm was obtained, with a yield of 80 mg. At the same time, fac-TzDm-t was also obtained (its amount was about 1 / 10 of mer-TzDm, and it was recrystallized using dichloromethane and ethanol). The yield (mer+fac) was 53%.

[0055] The above-mentioned carbene iridium phosphorescent complex was characterized and confirmed, and the confirmation results are as follows:

[0056] 1. Nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry

[0057] fac-TzDm: 1 H NMR(400MHz,Chloroform-d)δ7.60(d,J=7.7Hz,

[0058] 3H),7.33(d,J=7.6Hz,3H),7.07(td,J=7.8,7.2,2.2Hz,3H),7.01(td,J=7.6,1.1Hz,3H),6.7 8(td,J=7.3,1.1Hz,3H),6.60(d,J=6.3Hz,6H),6.53-6.46(m,3H),1.75(s,9H),1.66(s,9H). 13 C NMR (101MHz,CDCl3)δ166.30,164.72,145.31,143.92,142.92,136.46,136.13,127.81,126.40,125.89,123.55,121.22,112.24,111.62,39.77,27.39,25.28.Exact Mass ESI-MS: calculated results (m / z+H) + :974.3265,Experimental result:974.3266.

[0059] mer-TzDm: 1 H NMR(400MHz,Methylene Chloride-d2)δ7.71-7.56(m,3H),7.37(dd,J=16.9,7.5Hz,3H),7.23-7.07 (m,5H),7.02(t,J=8.1Hz,1H),6.91(q,J=7.5Hz,2H),6.87-6.65(m,6H),6. 58(d,J=8.0Hz,1H),6.48(d,J=8.0Hz,1H),5.93(d,J=8.1Hz,1H),5.58(d,J =8.1Hz,1H),1.79(s,3H),1.73(d,J=4.8Hz,6H),1.66(s,6H),1.61(s,3H). 13C NMR(101MHz,CD2Cl2)δ165.30,165.24,165.09,165.04,164.96,163.72,147.25,146.11,144.79,144.39,14 4.29,143.95,143.40,143.36,142.59,139.31,139.26,136.14,136.07,135.81,135.73,128.58,128.39,127 .63,126.50,126.41,126.38,126.34,126.13,125.98,123.68,122.89,122.75,121.67,121.35,120.91,115.54,115.37,113.20,112.83,112.47,111.43,39.84,39.71,39.65,27.25,26.80,26.59,25.15,25.13,25.11.

[0060] Exact Mass ESI-MS: Calculation results (m / z+H) + :974.3265, experimental result:974.3268;

[0061] fac-TzDm-t 1 H NMR(400MHz,Chloroform-d)δ7.50(d,J=8.1Hz,3H),7.33(d,J=7.3Hz,3H),7.08-6.99(m ,6H),6.79(d,J=7.8Hz,3H),6.51-6.39(m,6H),1.72(s,9H),1.70(s,9H),1.05(s,27H). 13 CNMR (101MHz,CDCl3)δ165.54,164.49,147.65,143.87,143.30,143.09,136.47,134.18,127.41,126.18,123.35,117.94,111.98,111.23,39.73,34.16,31.60,27.59,25.18.Exact Mass ESI-MS: calculated results (m / z+H) + :1142.5143, experimental result 1142.5140.

[0063] mer-TzDm-t 1H NMR(400MHz,Chloroform-d)δ7.59-7.50(m,3H),7.35-7.26(m,3H),7.17-7.07(m,3H),7.07-6.95(m,5H),6.84-6.75(m,3H),6.68(d,J=2.0Hz,1H),6. 32(t,J=7.8Hz,1H),5.74(d,J=8.1Hz,1H),5.62(d,J=8.1Hz,1H),1.72-1.6 5(m,12H),1.63(s,3H),1.61(s,3H),1.12(s,9H),0.95(s,9H),0.93(s,9H). 13 C NMR (101MHz, CDCl3) δ164.91,164.65,164.61,164.59,164.44,163.81,148.12,147.96,147.83,145.06,144.00,143.89 ,143.75,143.25,143.21,143.16,142.29,141.95,136.57,136.36,136.31,136.03,135.89,133.83,129.11,128.71,127 .00,126.17,126.05,126.02,123.08,122.32,122.22,118.18,117.98,117.79,116.44,116.26,112.89,112.45,112.15,111.75,39.83,39.58,39.57,34.22,33.95,33.93,31.67,31.55,31.51,27.49,26.73,26.64,25.81,25.66,25.33.Exact Mass ESI-MS: calculated results (m / z+H) + :1142.5143, experimental result:1142.5140;

[0064] 2. Single crystal structure

[0065] like Figure 2 .Structure diagram of fac-TzDm. Partial bond length Ir1-C(15)=2.075(9),Ir1-C(41)=2.05(1),Ir1-C(35)=2.043(8),Ir1-C(28)=2.018(8),Ir1-C(34)=2.09(1).Partial bond angles (°):C(9)-Ir1-C(34)=170.4(4),C(15)-Ir1-C(41)=164.7(4),C(28)-Ir1-C(35)=168.5(4).

[0066] like Figure 3 .Structure diagram of fac-TzDm-t.Partial bond length Ir1-C(10)=2.098, partial bond angle (°): C(9)-Ir1-C(10)=166.6(4).

[0067] like Figure 4 .Structure of mer-TzDm. Partial bond length Ir1-C(25)=2.057(7),Ir1-C(36)=2.130(5),Ir1-C(43)=2.079(5),Ir1-C(00H)=2.023(6),Ir1-C(18)=2.127(5).Partial bond angles (°):C(25)-Ir1-C(00H)=164.7(2),C(18)-Ir1-C(36)=178.3(3),C(19)-Ir1-C(43)=174.4(2).

[0068] like Figure 5 .Structure of mer-TzDm-t.Partial bond length 2.031(5),Ir01-C(00G)=2.071(5),Ir01-C(00C)=2.028(5),Ir01-C(00F)=2.118(6),Ir01-C(006)=2.059(5),Ir01-C(00B)=2.107(5).Partial bond angles(°):C(00F)-Ir01-C(00B)=177.5(2),C(006)-Ir01-C(00G)=166.2(2),C(00X)-Ir01-C(00C)=164.0(2).

[0069] 3. Determination of photophysical properties

[0070] The UV-visible absorption and emission spectra of the complexes mer-TzDm and fac-TzDm are shown in FIG6 .

[0071] The photophysical data of mer-TzDm, fac-TzDm, mer-TzDm-t and fac-TzDm-t are shown in Table 1:

[0072]

[0073] aAt a concentration of 1×10 -5 M was measured in deoxygenated DCM at room temperature. b Determined by relative method, with Firpic as reference. cτrad=τobs / PLQY.dkr=PLQY / τobs and knr=(1-PLQY) / τobs.

[0074] 4. Electrochemical and thermal stability determination

[0075] Table 2. Electrochemical and thermal stability data of triazole carbene iridium (III) complexes

[0076]

[0077]

[0078] The energy levels of the a frontier molecular orbitals are calculated using the following equation: in is measured in dichloromethane with Ag / Ag+ as reference electrode, and the energy gap Eg is estimated using the absorption onset:

[0079] Based on the same inventive concept, the present invention also provides a use of a deep blue light emitting triazole carbene iridium complex in an electroluminescent device.

[0080] Exemplarily, the electroluminescent device is an organic phosphorescent light-emitting diode, using indium tin oxide (ITO) as an anode, 1 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HATCN) as a hole injection layer (HIL), 4-[1-[4-[di(4-methylphenyl)amino]phenyl]cyclohexyl]-N-(3-methylphenyl)-N-(4-methylphenyl)aniline (TAPC) as a hole transport layer (HTL), iridium (III) complex dopant in the host as a light-emitting layer (Ir inDPEPO), diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide (TSPO1) as a hole blocking layer (HBL), 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) as a hole transport layer (ETL), LiF as an electron injection layer (EIL), and Al as a cathode. Since the iridium (III) complex has a higher LUMO energy level (about -2.0 eV), di[2-((oxy)diphenylphosphino)phenyl]ether (DPEPO) was selected as the host material. The device structure is as follows: ITO / HATCN (20nm) / TAPC (40nm) / iridium (III) complex (x wt%) in DPEPO (20nm) / TSPO1 (10nm) / TPBi (20nm) / LiF (1nm) / Al (100nm). In order to optimize the performance of the blue OLED device, the doping concentration of the iridium (III) complex was varied from 25 to 40 weight percent ( Figure 7 As shown). For example, a certain amount of iridium (III) complex dopant is used as a light-emitting layer in the host, and the energy level ranges from -2.0 to -6.1 eV at a thickness of 20 nm, the energy level ranges from -6.0 to -9.9 eV for HATCN (20 nm), the energy level ranges from -2.0 to -5.5 eV for TAPC (40 nm), the energy level ranges from -2.5 to -6.8 eV for TSPO1 (10 nm), and the energy level ranges from -2.7 to -6.2 eV for TPBi (20 nm).

[0081] The preparation of organic phosphorescent light-emitting diodes includes: the layers are deposited sequentially on a pre-cleaned ITO glass substrate, and the deposition process is carried out at a pressure of less than 10^-6Torr. During the preparation of OLEDs, the thermal evaporation rates of organic materials, LiF and Al are respectively and For each device, four pixel blocks with the same device configuration were prepared in one batch, with the deposited Al cathode overlapping the pre-coated ITO anode to form an active area of ​​2 mm × 2 mm for each pixel block. The EL spectra of the devices were measured in the normal direction using an Ocean Optics USB 2000. The JVL curves were studied using a dual-channel Keithley 2614B source measurement unit and a PIN-25D silicon photodiode. Its luminescence performance is shown in Figure 2. Figure 8 shown.

[0082] Table 3. Summary of the performance of blue OLED devices based on mer-TzDm and mer-TzDm-t.

[0083]

[0084] a Turn-on voltage (Von) at a brightness of 1 cd m^-2. b Maximum efficiency. c External quantum efficiency (EQE) at a brightness of 100 cd m^-2. d External quantum efficiency (EQE) at a brightness of 1000 cd m^-2.

[0085] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. Deep blue light emitting triazole carbene iridium complex, the general structure of which is as follows: in, R3-R10 are independently selected from any one of hydrogen, deuterium, alkyl, aryl, halogen, cyano, acyl, amino and substituted amino, hydroxyl, thiol, alkoxy, alkylthio, silane, fluorine-containing hydrocarbon, ester and amide; R1-R2 are independently selected from any one of hydrogen, deuterium, alkyl and aryl; Preferably, R1 to R2 are independently selected from deuterated alkyl or deuterated aromatic groups; R3 to R10 are independently selected from any one of deuterated alkyl, deuterated aromatic groups, deuterated acyl groups, deuterated amino groups and deuterated substituted amino groups, deuterated hydroxyl groups, deuterated thiol groups, deuterated alkoxy groups, deuterated alkylthio groups, deuterated silanyl groups, deuterated fluorinated hydrocarbon groups, deuterated ester groups and deuterated amide groups.

2. The deep blue light emitting triazole carbene iridium complex according to claim 1, characterized in that: The ligand structural formula constituting the carbene iridium phosphorescent complex is: Wherein, X is selected from any one of tetrafluoroborate ion, hexafluorophosphate ion, hexafluorosilicate ion, hexafluoroaluminate ion, perchlorate ion, hexafluoroarsenate ion, trifluoromethanesulfonate ion, methanesulfonate ion, trifluoroacetate ion, acetylacetonate ion, fluoride ion, chloride ion, bromide ion and iodide ion.

3. The deep blue light emitting triazole carbene iridium complex according to claim 1, characterized in that: The carbene iridium phosphorescent complex includes a meridional structure and a planar structure.

4. The deep blue light emitting triazole carbene iridium complex according to claim 1, characterized in that The deep blue light emitting triazole carbene iridium complex comprises:

5. A method for preparing the deep blue light emitting triazole carbene iridium complex according to claim 1, characterized in that: include: The ligand, (1,5-cyclooctadiene)iridium(I) chloride dimer and a base are mixed, a first solvent is added, and Ag2O is not used, and the mixture is refluxed at 100 to 180° C. to obtain a suspension; filtering and eluting the suspension to obtain the deep blue light emitting triazole carbene iridium complex; The general structural formula of the ligand is:

6. The method for preparing the deep blue light emitting triazole carbene iridium complex according to claim 5, characterized in that: The base includes: potassium carbonate, sodium carbonate, lithium carbonate, cesium carbonate, potassium acetate, sodium acetate, lithium acetate, cesium acetate, potassium tert-butoxide, sodium tert-butoxide, lithium tert-butoxide, cesium tert-butoxide, triethylamine, trimethylamine, 1,8-diazabicyclo (5.4.0) undec-7-ene, triethylammonium, 6-cyanomethyl-2,2-dimethyl-1,3-dioxolane-acetic acid tert-butyl ester and diisopropylethylenediamine; the first solvent includes: chlorobenzene, dichlorobenzene, trichlorobenzene, benzene, toluene, disubstituted toluene, Trisubstituted toluene, ethylbenzene, fluorobenzene, trifluorobenzene, dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 2-methyltetrahydrofuran, 1,4-dioxane, NMP, cyclopentane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, C to C alkanes, methanol, ethanol, butanol, tri-amyl alcohol, tert-butanol, glycerol and its substitutes, ethylene glycol, polyethylene glycol and its substitutes.

7. The method for preparing the deep blue light emitting triazole carbene iridium complex according to claim 5, characterized in that: The equivalent of the (1,5-cyclooctadiene)iridium (I) chloride dimer is defined as 1, the equivalent of the ligand is defined as 6-10, and the equivalent of the base is defined as 6-10.

8. The method for preparing the deep blue light emitting triazole carbene iridium complex according to claim 5, characterized in that: The preparation method of the ligand comprises: Mixing raw material A, a second solvent and trimethyloxonium tetrafluoroboric acid, and reacting at -20 to 80° C. to obtain a reaction mixture; The reaction mixture is mixed with phenylhydrazine or phenylhydrazine with a substituent, and the second solvent is removed after the reaction, wherein the reaction process does not require transition metal catalysis and does not require column chromatography separation to obtain the ligand; The structural formula of the raw material A is: The second solvent includes chlorobenzene, dichlorobenzene, trichlorobenzene, benzene, toluene, disubstituted toluene, trisubstituted toluene, ethylbenzene, fluorobenzene, trifluorobenzene, dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 2-methyltetrahydrofuran, 1,4-dioxane, NMP, cyclopentane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, and C to C alkanes.

9. The method for preparing the deep blue light emitting triazole carbene iridium complex ligand according to claim 8, characterized in that: The second solvent is an aprotic solvent: the equivalent of the raw material A is defined as 1, the equivalent of the trimethyloxonium tetrafluoroboric acid is defined as 0.8-3; and the equivalent of the phenylhydrazine or substituted phenylhydrazine is defined as 0.8-3.

10. Use of the deep blue light emitting triazole carbene iridium complex according to claim 1 in an electroluminescent device.

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