Metal complexes and their applications

Abstract

The metal complex has the general formula Ir(La)(Lb)(Lc), and its structure is shown in formula (1). This metal complex has advantages such as low sublimation temperature, good optical and electrical stability, high luminous efficiency, long lifetime, and high color saturation, and can be used in organic light-emitting devices, especially as a red-emitting phosphorescent material, which may be applied in the AMOLED industry. JPEG2023552218000049.jpg67170

Description

[Technical field]

[0001] The present invention relates to the field of organic electroluminescence technology, in particular to organic light-emitting materials, especially metal complexes and their application in organic electroluminescent devices. [Background technology]

[0002] At present, as a new generation display technology, organic electroluminescence devices (OLEDs) have attracted more and more attention in the fields of display and lighting technology, and their application prospects are very broad. However, compared with market application requirements, the luminous efficiency, driving voltage, service life and other performances of OLED devices still need to be continuously enhanced and improved.

[0003] Generally, the basic structure of an OLED device is a sandwich-like structure, with various organic functional material thin films with different functions interposed between metal electrodes. Under the driving of electric current, holes and electrons are injected from the cathode and anode respectively, and after the holes and electrons travel a certain distance, they recombine in the light-emitting layer and are released in the form of light or heat, thereby generating the light emission of the OLED.

[0004] However, organic functional materials are the core components of organic electroluminescent devices, and the thermal stability, photochemical stability, electrochemical stability, quantum yield, film formation stability, crystallinity, color saturation, etc. of the materials are the main factors that affect the device performance.

[0005] Generally, organic functional materials include fluorescent materials and phosphorescent materials. Usually, fluorescent materials are organic small molecule materials, and generally can emit light by utilizing 25% singlet state, so that the luminous efficiency is relatively low. On the other hand, phosphorescent materials can utilize the energy of 75% triplet excitons in addition to 25% singlet state due to the spin-orbit coupling action by heavy atom effect, so that the luminous efficiency can be greatly improved. However, compared with fluorescent materials, phosphorescent materials have a relatively slow onset, and it is necessary to improve the thermal stability, life, and saturation of the material, which is a challenging theme. As such phosphorescent materials, various organometallic compounds have been developed. For example, the invention patent document CN107973823 discloses quinoline iridium compounds, but the saturation and device performance of such compounds, especially the luminous efficiency and device lifetime, need to be improved. The invention patent document CN106459114 discloses iridium compounds coordinated with β-diketone ligands, but the sublimation temperature of such compounds is high, the saturation is not good, and especially the performance of device performance is not ideal, and needs to be further improved. Invention patent CN109721628 discloses compounds with fluorenylthienopyrimidine structure, and organic electroluminescent devices and compounds containing the compounds. Invention patents CN111377969A and CN111620910A disclose complexes with dibenzofuran biisoquinoline structure, and organic electroluminescent devices and compounds containing the complexes.

[0006] However, there remains a need to further develop new materials that improve the performance of organic electroluminescent devices. Summary of the Invention

[0007] The present invention has been made to solve the above problems, and an object of the present invention is to provide a high-performance organic electroluminescence device and a novel material capable of realizing such an organic electroluminescence device.

[0008] As a result of intensive research to achieve the above-mentioned object, the inventors have found that a high-performance organic electroluminescence device can be obtained by using a metal complex containing a structure represented by the following formula (1) as a ligand.

[0009] One of the objectives of the present invention is to provide a metal complex that can be used in organic electroluminescent devices, with the advantages of low sublimation temperature, high optical and electrochemical stability, high color saturation, high luminous efficiency, long device life, etc., and has potential applications in the OLED industry, especially as a red-emitting dopant.

[0010] The metal complex has the general formula Ir(La)(Lb)(Lc) and its structural formula is shown in formula (1). JPEG0007600403000001.jpg67170JPEG0007600403000002.jpg49137 is the ligand La, X is independently selected from O, S, and Se; R 1 -R 5 are independently hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted C3-C30 alkylsilyl group, a substituted or unsubstituted C1-C10 alkoxy group, a substituted or unsubstituted C7-C3 is selected from a substituted or unsubstituted C6-C30 aralkyl group, a substituted or unsubstituted C6-C30 aryloxy group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a substituted or unsubstituted C3-C30 arylsilyl group, a substituted or unsubstituted C0-C20 alkylamino group, a cyano group, a nitrile, an isonitrile, and a phosphino group; R 1 -R 5at least one of the above is F, and one of the above is a substituted or unsubstituted alkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 main chain carbon atoms, or a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, R 6 is a substituted or unsubstituted alkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 main chain carbon atoms, or a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, the substitution is by deuterium, F, Cl, Br, a C1-C4 alkyl group, a C1-C4 alkoxy group, a C3-C6 cycloalkyl group, an amino group substituted with a C1-C4 alkyl group, a cyano group, a nitrile, an isonitrile, or a phosphino group; The heteroatom in the heteroalkyl group, heterocycloalkyl group, or heteroaryl group is at least one of S, O, and N; Lb and Lc are both monoanionic bidentate ligands, and any two of La, Lb, and Lc are linked to form a multidentate ligand, or the three are linked via one group; At least two of the three, La, Lb, and Lc, are the same.

[0011] In a preferred metal complex, Lb has a structure represented by formula (2): In the formula, the position of the dashed line represents the position where the metal Ir is bonded. R a -R g are independently selected from hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 main chain carbon atoms, and a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, or R a , R b , Rc are linked in pairs to form an aliphatic ring structure, and R e , R f , R g are linked in pairs to form an aliphatic ring structure, and the substitution is by deuterium, F, Cl, Br, a C1-C4 alkyl group, a C1-C4 alkoxy group, a C3-C6 cycloalkyl group, an amino group substituted with a C1-C4 alkyl group, a cyano group, a nitrile, an isonitrile, or a phosphino group.

[0012] A preferred metal complex is one in which Lc and La have the same structure, (La) 2 The Ir(Lb) structure is formed.

[0013] R a , R b , R c are R e , R f、 R g is the same as:

[0014] R a , R b , R c , R e , R f、 R g are independently selected from hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms in the main chain, and a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, or R a , R b , R c are linked in pairs to form an aliphatic ring structure, and R e , R f , R g are linked in pairs to form an aliphatic ring structure, the substitution is by deuterium, F, Cl, Br, a C1-C4 alkyl group, or a C3-C6 cycloalkyl group, and R d is selected from hydrogen, deuterium, halogen, and a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms in the main chain.

[0015] Preferred metal complexes include R 6is a substituted or unsubstituted alkyl group having 4 or less main chain carbon atoms, or a substituted or unsubstituted cycloalkyl group having 6 or less ring carbon atoms.

[0016] In a preferred metal complex, F is R 5 is not in the position.

[0017] X is an oxygen atom O.

[0018] Preferred metal complexes include R 1 -R 5 One of these is F, another is a substituted or unsubstituted alkyl group having 4 or less main chain carbon atoms or a substituted or unsubstituted cycloalkyl group having 6 or less ring carbon atoms, and the remaining three are all hydrogen.

[0019] Preferred metal complexes include R 1 -R 5 When one of is F, the other is a branched alkyl group having up to 4 main chain carbon atoms with C1-C4 alkyl group substitution.

[0020] In preferred metal complexes, La is independently selected from one of the following structural formulas or their corresponding partial or full deuterides, or their corresponding partial or full fluorides:

[0021] JPEG0007600403000004.jpg255169JPEG0007600403000005.jpg255160JPEG0007600403000006.jpg25515 7JPEG0007600403000007.jpg255161JPEG0007600403000008.jpg255160JPEG0007600403000009.jpg82170

[0022] In preferred metal complexes, Lb is independently selected from one of the following structural formulas or their corresponding partial or full deuterides or fluorides:

[0023] JPEG0007600403000010.jpg249170

[0024] The ligand La has the structure shown below: JPEG0007600403000011.jpg67156R1-R6, X is as defined above.

[0025] Another object of the present invention is to provide an electroluminescent device comprising a cathode, an anode, and organic layers disposed between the cathode and the anode, at least one of the organic layers comprising the metal complex.

[0026] the organic layer is an emitting layer, and the metal complex is used as a red-emitting doping material of the emitting layer; Alternatively, the organic layer is a hole-injection layer, and the metal complex is used as a hole-injection material in the hole-injection layer.

[0027] The material of the present invention not only has the advantages of low sublimation temperature, high optical and electrochemical stability, high color saturation, high luminous efficiency, long device life, etc. As a phosphorescent material, the material of the present invention can convert the triplet excited state into light, so that the luminous efficiency of the organic electroluminescent device can be improved, thereby reducing energy consumption. [Brief description of the drawings]

[0028] [Figure 1] 1 is a 1H NMR spectrum of the compound La027 of the present invention in a deuterated chloroform solution. [Diagram 2] 1 is a 1H NMR spectrum of the compound Ir(La027)2(Lb005) of the present invention in a deuterated chloroform solution. [Diagram 3] 1 shows the ultraviolet absorption spectrum and emission spectrum of the compound Ir(La027)2(Lb005) of the present invention in dichloromethane solution. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The metal complex has the general formula Ir(La)(Lb)(Lc) and its structural formula is shown in formula (1). JPEG0007600403000012.jpg72170JPEG0007600403000013.jpg50131 is the ligand La, X is independently selected from O, S, and Se; R 1 -R 5 are independently hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted C3-C30 alkylsilyl group, a substituted or unsubstituted C1-C10 alkoxy group, a substituted or unsubstituted C7-C3 is selected from a substituted or unsubstituted C6-C30 aralkyl group, a substituted or unsubstituted C6-C30 aryloxy group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a substituted or unsubstituted C3-C30 arylsilyl group, a substituted or unsubstituted C0-C20 alkylamino group, a cyano group, a nitrile, an isonitrile, and a phosphino group; R 1 -R 5 at least one of the above is F, and one of the above is a substituted or unsubstituted alkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 main chain carbon atoms, or a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, R 6is a substituted or unsubstituted alkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 main chain carbon atoms, or a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, the substitution is by deuterium, F, Cl, Br, a C1-C4 alkyl group, a C1-C4 alkoxy group, a C3-C6 cycloalkyl group, an amino group substituted with a C1-C4 alkyl group, a cyano group, a nitrile, an isonitrile, or a phosphino group; The heteroatom in the heteroalkyl group or heteroaryl group is at least one of S, O, and N; Lb and Lc are both monoanionic bidentate ligands, and any two of La, Lb, and Lc are linked to form a multidentate ligand, or the three are linked via one group; At least two of the three, La, Lb, and Lc, are the same.

[0030] In a preferred metal complex, Lb has a structure represented by formula (2): In the formula, the position of the dashed line represents the position where the metal Ir is bonded. R a -R g are independently selected from hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 main chain carbon atoms, and a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, or R a , R b , R c are linked in pairs to form an aliphatic ring structure, and R e , R f , R gare linked in pairs to form an aliphatic ring structure, and the substitution is by deuterium, F, Cl, Br, a C1-C4 alkyl group, a C1-C4 alkoxy group, a C3-C6 cycloalkyl group, an amino group substituted with a C1-C4 alkyl group, a cyano group, a nitrile, an isonitrile, or a phosphino group.

[0031] A preferred metal complex is one in which Lc and La have the same structure, (La) 2 The Ir(Lb) structure is formed.

[0032] R a , R b , R c are R e , R f、 R g is the same as:

[0033] R a -R g are independently selected from hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms in the main chain, and a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, or R a , R b , R c are linked in pairs to form an aliphatic ring structure, and R e , R f , R g are linked in pairs to form an aliphatic ring structure, and the substitution is by deuterium, F, Cl, Br, a C1-C4 alkyl group, or a C3-C6 cycloalkyl group.

[0034] R d is selected from hydrogen, deuterium, halogen, and a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms in the main chain.

[0035] Preferred metal complexes include R 6 is a substituted or unsubstituted alkyl group having 4 or less main chain carbon atoms, or a substituted or unsubstituted cycloalkyl group having 6 or less ring carbon atoms.

[0036] In a preferred metal complex, F is R 5is not in the position.

[0037] X is an oxygen atom O.

[0038] Preferred metal complexes include R 1 -R 5 One of these is F, another is a substituted or unsubstituted alkyl group having 4 or less main chain carbon atoms or a substituted or unsubstituted cycloalkyl group having 6 or less ring carbon atoms, and the remaining three are all hydrogen. Preferred metal complexes include R 1 -R 5 When one of is F, the other is a branched alkyl group having up to 4 main chain carbon atoms with C1-C4 alkyl group substitution.

[0039] Examples of each group in the compound represented by formula (1) will be described below.

[0040] In this specification, the "number of carbon atoms a to b" in the expression "a substituted or unsubstituted X group having a carbon number a to b" represents the number of carbon atoms when the X group is unsubstituted, and does not include the number of carbon atoms of the substituent when the X group is substituted.

[0041] The C1-C10 alkyl group is a straight-chain or branched-chain alkyl group, specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl and its isomers, n-hexyl and its isomers, n-heptyl and its isomers, n-octyl and its isomers, n-nonyl and its isomers, n-decyl and its isomers, etc., preferably methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, more preferably propyl, isopropyl, isobutyl, sec-butyl, tert-butyl.

[0042] Examples of the C3 to C20 cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-norbornyl, and 2-norbornyl, with cyclopentyl and cyclohexyl being preferred.

[0043] Examples of the C2 to C10 alkenyl group include vinyl, propenyl, allyl, 1-butadienyl, 2-butadienyl, 1-hexatrienyl, 2-hexatrienyl, and 3-hexatrienyl, with propenyl and allyl being preferred.

[0044] Examples of the C1-C10 heteroalkyl group include linear or branched alkyl groups and cycloalkyl groups containing atoms other than carbon and hydrogen, and include mercaptomethylmethane group, methoxylmethane group, ethoxylmethane group, tert-butoxylmethane group, N,N-dimethylmethane group, epoxybutane group, epoxypentane group, and epoxyhexane group, with methoxylmethane group and epoxypentane group being preferred.

[0045] Specific examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a phenanthrenyl group, a naphthacenyl group, a pyrenyl group, a chrysenyl group, a benzo[c]phenanthrenyl group, a benzo[g]chrysenyl group, a fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a biphenylyl group, a terphenylyl group, a quaterphenylyl group, and a fluoroanthryl group, and of these, a phenyl group and a naphthyl group are preferred.

[0046] Specific examples of the heteroaryl group include a pyrrolyl group, a pyrazinyl group, a pyridyl group, a pyrimidinyl group, a triazinyl group, an indolyl group, an isoindolyl group, an imidazolyl group, a furanyl group, a benzofuranyl group, an isobenzofuranyl group, a dibenzofuranyl group, a dibenzothienyl group, an azadibenzofuranyl group, an azadibenzothienyl group, a diazadibenzofuranyl group, a quinolyl group, an isoquinolyl group, a quinoxalyl group, a carbazolyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, and a phenazinyl group. group, a phenothiazinyl group, a phenoxazinyl group, an oxazolinyl group, an oxadiazolyl group, a furazanyl group, a thienyl group, a benzothienyl group, a dihydroacridinyl group, an azacarbazolyl group, a diazacarbazolyl group, and a quinazolinyl group. Of these, a pyridyl group, a pyrimidinyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothienyl group, an azadibenzofuranyl group, an azadibenzothienyl group, a diazadibenzofuranyl group, a diazadibenzothienyl group, a carbazolyl group, an azacarbazolyl group, and a diazacarbazolyl group are preferred.

[0047] The following examples are merely intended to facilitate understanding of the technical invention and should not be construed as specific limitations of the present invention.

[0048] All raw materials and solvents involved in the synthesis of the compounds of the present invention were purchased from suppliers well known to those skilled in the art, such as Alfa and Acros.

[0049] Synthesis of the ligand La001: JPEG0007600403000015.jpg45170

[0050] Synthesis of compound 3 Compound 1 (20.00 g, 76.78 mmol, 1.0 eq), compound 2 (10.12 g, 115.17 mmol, 1.5 eq), dichlorobis[di-tert-butyl(4-dimethylaminophenyl)phosphine]palladium(II) (2.72 g, 3.84 mmol, 0.05 eq), anhydrous potassium phosphate (40.74 g, 191.95 mmol, 2.5 eq), and toluene (300 ml) were added to a 1 L three-neck flask, evacuated, purged with nitrogen three times, and reacted under nitrogen protection at 100°C for 4 hours with stirring. Compound 1 was completely reacted as monitored by TLC. The mixture was cooled to room temperature, concentrated under reduced pressure to remove the organic solvent, extracted with dichloromethane (150 ml) and deionized water (60 ml), spin-dried, and separated by column chromatography (eluent: ethyl acetate: n-hexane = 1:100). After concentration, a pale yellow solid was obtained as compound 3 (9.68 g, yield: 56.35%). Mass spectrum: 224.67 (M+H).

[0051] Synthesis of compound La001: Compound 3 (9.20 g, 41.13 mmol, 1.0 eq), compound 4 (10.23 g, 45.24 mmol, 1.1 eq), dichlorobis[di-tert-butyl(4-dimethylaminophenyl)phosphine]palladium(II) (1.46 g, 2.06 mmol, 0.05 eq), potassium carbonate (11.37 g, 082.26 mmol, 2.00 eq), toluene (138 ml), ethanol (46 ml), and deionized water (46 ml) were placed in a 500 mL three-neck flask, evacuated and purged with nitrogen three times, and reacted under nitrogen protection at 70°C for 1 hour with stirring. Compound 3 was completely reacted as monitored by TLC. The mixture was cooled to room temperature, concentrated under reduced pressure to remove the organic solvent, extracted with dichloromethane (200 ml) and deionized water (80 ml), and then spin-dried and separated by column chromatography (eluent: ethyl acetate: n-hexane = 1.5:100). After concentration, a white solid was obtained as compound La001 (9.49 g, yield: 62.44%), with a mass spectrum of 370.43 (M+H).

[0052] Compound Ir(La001) 2 Synthesis of Lb005: JPEG0007600403000016.jpg38170

[0053] Synthesis of compound Ir(La001)-1: Compound La001 (8.18g, 22.13mmol, 3.5eq), IrCl 3 .3H 2 O (2.23 g, 6.32 mmol, 1.0 eq) was placed in a 500-mL one-neck round-bottom flask, ethylene glycol ethyl ether (82 mL) and deionized water (27 mL) were added, and the mixture was evacuated three times to remove N 2 The mixture was stirred at 110° C. for 20 hours under protection. After cooling to room temperature, methanol (90 ml) was added and stirred to precipitate a solid. The solid was collected by filtration and dried to obtain a dark red oil as compound Ir(La001)-1 (5.51 g, 90.28%). The obtained compound was used directly in the next step without further purification.

[0054] Compound Ir(La001) 2 Synthesis of Lb005: Compound Ir(La001)-1 (5.50 g, 5.7 mmol, 1.0 eq), Lb005 (6.05 g, 28.51 mmol, 5.0 eq), and sodium carbonate (6.04 g, 57.02 mmol, 10.0 eq) were placed in a 250-mL single-neck round-bottom flask, ethylene glycol ethyl ether (55 mL) was added, and the mixture was subjected to vacuum replacement three times. 2 The reaction was stirred under protection at 30°C for 19 hours, and monitored by TLC, showing that La001-1 had reacted completely. After cooling to room temperature, 60 ml of methanol was added, slurried at room temperature for 2 hours, and filtered by suction. The filter cake was dissolved and clarified with dichloromethane (80 ml), filtered through silica gel, and the filtrate was washed three times with deionized water (80 ml), separated, and the organic phase was collected, concentrated, and dried to obtain a dark red solid. The product was recrystallized three times using tetrahydrofuran / methanol (product / tetrahydrofuran / methanol=1g / 6ml / 4ml) and dried to obtain compound Ir(La001). 2A red solid was obtained which was Lb005 (2.72 g, yield: 41.82%). 2.72 g of Ir(La001) 2 After the crude Lb005 product was purified by sublimation, the sublimed pure Ir(La001) 2 Lb005 was obtained (1.63 g, yield: 59.92%). Mass spectrum: 1141.38 (M+H). 1 H NMR (400 MHz, CDCl 3 ) δ 8.70 (d, J = 8.8 Hz, 2H), 8.31(d, J = 6.5 Hz, 2H), 7.78 (d, J = 7.4 Hz, 2H), 7.55 (d, J = 6.5 Hz, 2H), 7.50 - 7.39 (m, 4H), 7.38- 7.29 (m, 4H), 7.25 (d, J = 7.3 Hz, 2H), 4.84 (s, 1H), 2.16 - 2.06 (m, 2H), 1.65- 1.51(m, 9H), 1.24 (t, J = 11.1 Hz, 3H), 1.10 - 0.98 (m, 12H), 0.86 - 0.71 (m, 4H), 0.51 (t, J = 7.4 Hz, 6H), -0.11 (t, J = 7.3 Hz, 6H).

[0055] Synthesis of compound La002: JPEG0007600403000017.jpg45170

[0056] Synthesis of compound 6 Referring to the synthesis and purification method of compound 3, the corresponding raw materials were changed to obtain the target compound 6. Mass spectrum: 224.67 (M+H).

[0057] Synthesis of compound La002: Referring to the synthesis and purification method of compound La001, the target compound La002 was obtained by simply changing the corresponding raw materials. Mass spectrum: 370.43 (M+H).

[0058] Compound Ir(La002) 2 Synthesis of Lb005: JPEG0007600403000018.jpg35170

[0059] Synthesis of compound Ir(La002)-1: Referring to the synthesis and purification method of compound Ir(La001)-1, all that is needed is to change the corresponding raw materials, and the obtained compound Ir(La002)-1 was used directly in the next step without purification.

[0060] Compound Ir(La002) 2 Synthesis of Lb005: Compound Ir(La001) 2 Referring to the synthesis and purification method of Lb005, we only need to change the corresponding raw materials, and the compound Ir(La002) 2 A red solid was obtained as Lb005 (2.44g, yield: 40.21%). 2.44g of Ir(La002) 2 After the crude Lb005 product was purified by sublimation, the sublimed pure Ir(La002) 2 Lb005 was obtained (1.56 g, yield: 59.42%). Mass spectrum: 1141.38 (M+H). 1 H NMR (400 MHz, CDCl 3 ) δ 8.62 (d, J = 8.5 Hz, 2H), 8.21(d, J = 6.5 Hz, 2H), 7.52(d, J = 7.4 Hz, 2H), 7.42(d, J = 6.5 Hz, 2H), 7.40 - 7.33 (m, 4H), 7.31- 7.26 (m, 4H), 7.23 (d, J = 7.3 Hz, 2H), 4.83 (s, 1H), 2.16 - 2.06 (m, 2H), 1.65- 1.51(m, 9H), 1.24 (t, J = 11.1 Hz, 3H), 1.12 - 0.99(m, 12H), 0.86 - 0.71 (m, 4H), 0.52 (t, J = 7.4 Hz, 6H), -0.11 (t, J = 7.3 Hz, 6H).

[0061] Synthesis of compound La027: JPEG0007600403000019.jpg48170

[0062] Synthesis of compound 8 Referring to the synthesis and purification method of compound 3, the corresponding raw materials were changed to obtain the target compound 8. Mass spectrum: 238.07 (M+H).

[0063] Synthesis of compound La027: Referring to the synthesis and purification method of compound La001, the corresponding raw materials were changed to obtain the target compound La027. Mass spectrum: 384.46 (M+H). 1 H NMR (400 MHz, CDCl 3 ) δ 8.74 (d, J = 5.8 Hz, 1H), 7.98 (t, J = 6.3 Hz, 2H), 7.90 (s, 1H), 7.55 (d, J = 8.6 Hz, 1H), 7.51 (s, 1H), 7.41 (d, J = 3.2 Hz, 2H), 7.37 - 7.32 (m, 1H), 7.27 (d, J = 7.9 Hz, 1H), 2.74 (d, J = 7.3 Hz, 2H), 2.60 (s, 3H), 2.07 - 1.98 (m, 1H), 0.98 (d, J = 6.6 Hz, 6H).

[0064] Compound Ir(La027) 2 Synthesis of Lb005: JPEG0007600403000020.jpg31170

[0065] Synthesis of compound Ir(La027)-1: Referring to the synthesis and purification method of compound Ir(La001)-1, all that is needed is to change the corresponding raw materials, and the obtained compound Ir(La027)-1 was used directly in the next step without purification.

[0066] Compound Ir(La027) 2 Synthesis of Lb005: Compound Ir(La001) 2Referring to the synthesis and purification method of Lb005, we only need to change the corresponding raw materials to obtain the compound Ir(La027). 2 A red solid was obtained as Lb005 (2.15g, yield: 42.33%). 2.15g of Ir(La027) 2 After the crude product of Lb005 was purified by sublimation, the sublimed pure Ir(La027) 2 Lb005 was obtained (1.32 g, yield: 61.39%). Mass spectrum: 1169.44 (M+H). 1 H NMR (400 MHz, CDCl 3 )δ 8.73 (d, J = 8.8 Hz, 2H), 8.33 (d, J = 6.5 Hz, 2H), 7.80 (d, J = 7.4 Hz, 2H), 7.57 (d, J = 6.5 Hz, 2H), 7.52 - 7.42 (m, 4H), 7.40 - 7.31 (m, 4H), 7.28 (d, J = 7.3 Hz, 2H), 4.84 (s, 1H), 2.82 (dd, J = 15.0, 6.9 Hz, 4H), 2.17 - 2.07 (m, 2H), 1.68 - 1.53 (m, 9H), 1.27 (t, J = 11.1 Hz, 3H), 1.12 - 0.99 (m, 12H), 0.87 - 0.72 (m, 4H), 0.49 (t, J = 7.4 Hz, 6H), -0.10 (t, J = 7.3 Hz, 6H).

[0067] Compound Ir(La027) 2 Synthesis of Lb031: JPEG0007600403000021.jpg42170

[0068] Compound Ir(La027) 2 Synthesis of Lb031: Compound Ir(La001) 2 Referring to the synthesis and purification method of Lb005, we only need to change the corresponding raw materials to obtain the compound Ir(La027). 2 A red solid was obtained as Lb031 (2.67g, yield: 44.68%). 2.67g of Ir(La027) 2After the crude product of Lb031 was purified by sublimation, the sublimed pure Ir(La027) 2 Lb031 was obtained (1.54 g, yield: 57.67%). Mass spectrum: 1193.46 (M+H). 1 H NMR (400 MHz, CDCl 3 ) 8.73 (d, J = 8.8 Hz, 2H), 8.33 (d, J = 6.5 Hz, 2H), 7.80 (d, J = 7.4 Hz, 2H), 7.57 (d, J = 6.5 Hz, 2H), 7.52 - 7.42 (m, 4H), 7.40 - 7.31 (m, 4H), 7.28 (d, J = 7.3 Hz, 2H), 4.84 (s, 1H), 2.82 (dd, J = 15.0, 6.9 Hz, 4H), 2.17 - 2.07 (m, 2H), 1.92 (s, 6H), 1.83(d, 4H), 1.78- 1.65 (m, 16H), 0.90- 0.75 (m, 4H), 0.53 (t, J = 7.4 Hz, 4H), 0.13 (t, J = 7.3 Hz, 6H).

[0069] Synthesis of compound La028: JPEG0007600403000022.jpg44170

[0070] Synthesis of compound 9 Referring to the synthesis and purification method of compound 3, the corresponding raw materials were changed to obtain the target compound 9. Mass spectrum: 238.07 (M+H).

[0071] Synthesis of compound La028: Referring to the synthesis and purification method of compound La001, the corresponding raw materials were changed to obtain the target compound La028. Mass spectrum: 384.46 (M+H).

[0072] Compound Ir(La028) 2 Synthesis of Lb005: JPEG0007600403000023.jpg36170

[0073] Synthesis of compound Ir(La028)-1: Referring to the synthesis and purification method of compound Ir(La001)-1, all that is required is to change the corresponding raw materials, and the obtained compound Ir(La028)-1 was used directly in the next step without purification.

[0074] Compound Ir(La028) 2 Synthesis of Lb005: Compound Ir(La001) 2 Referring to the synthesis and purification method of Lb005, we only need to change the corresponding raw materials, and the compound Ir(La028) 2 A red solid was obtained as Lb005 (1.96g, yield: 38.77%). 1.96g of Ir(La028) 2 After the crude product of Lb005 was purified by sublimation, the sublimed pure Ir(La028) 2 Lb005 was obtained (1.14 g, yield: 58.16%). Mass spectrum: 1169.44 (M+H). 1 H NMR (400 MHz, CDCl 3 )δ 8.77 (d, J = 8.6 Hz, 2H), 8.35 (d, J = 6.6Hz, 2H), 7.82(d, J = 7.4 Hz, 2H), 7.59 (d, J = 6.5 Hz, 2H), 7.54 - 7.44 (m, 4H), 7.43 - 7.34 (m, 4H), 7.31 (d, J = 7.3 Hz, 2H), 4.83 (s, 1H), 2.83 (dd, J = 15.1, 6.7Hz, 4H), 2.19 - 2.08 (m, 2H), 1.68 - 1.55 (m, 9H), 1.28 (t, J = 11.3Hz, 3H), 1.13 - 0.99 (m, 12H), 0.88 - 0.73 (m, 4H), 0.51 (t, J = 7.4 Hz, 6H), -0.09 (t, J = 7.3 Hz, 6H).

[0075] Synthesis of compound La037: JPEG0007600403000024.jpg44170

[0076] Synthesis of compound 11 Referring to the synthesis and purification method of compound 3, the corresponding raw materials were changed to obtain the target compound 11. Mass spectrum: 238.07 (M+H).

[0077] Synthesis of compound La037: Referring to the synthesis and purification method of compound La001, the corresponding raw materials were changed to obtain the target compound La037. Mass spectrum: 384.46 (M+H).

[0078] Compound Ir(La037) 2 Synthesis of Lb005: JPEG0007600403000025.jpg34170

[0079] Synthesis of compound Ir(La037)-1: Referring to the synthesis and purification method of compound Ir(La001)-1, all that is needed is to change the corresponding raw materials, and the obtained compound Ir(La037)-1 was used directly in the next step without purification.

[0080] Compound Ir(La037) 2 Synthesis of Lb005: Compound Ir(La001) 2 Referring to the synthesis and purification method of Lb005, we only need to change the corresponding raw materials to obtain the compound Ir(La037). 2 A red solid was obtained which was Lb005 (1.96g, yield: 38.77%). 1.96 of Ir(La037) 2 After the crude product of Lb005 was purified by sublimation, the sublimed pure Ir(La037) 2 Lb005 was obtained (1.14 g, yield: 58.16%). Mass spectrum: 1169.44 (M+H). 1 H NMR (400 MHz, CDCl 3)δ 8.71 (d, J = 8.6 Hz, 2H), 8.29 (d, J = 6.6Hz, 2H), 7.76(d, J = 7.4 Hz, 2H), 7.54 (d, J = 6.5 Hz, 2H), 7.50- 7.39 (m, 4H), 7.37 - 7.27 (m, 4H), 7.22 (d, J = 7.3 Hz, 2H), 4.83 (s, 1H), 2.83 (dd, J = 15.1, 6.7Hz, 4H), 2.19 - 2.08 (m, 2H), 1.68 - 1.55 (m, 9H), 1.28 (t, J = 11.3Hz, 3H), 1.13 - 0.99 (m, 12H), 0.88 - 0.73 (m, 4H), 0.51 (t, J = 7.4 Hz, 6H), -0.09 (t, J = 7.3 Hz, 6H).

[0081] Synthesis of compound La080: JPEG0007600403000026.jpg53170

[0082] Synthesis of compound 13 Referring to the synthesis and purification method of compound 3, the corresponding raw materials were changed to obtain the target compound 13. Mass spectrum: 252.73 (M+H).

[0083] Synthesis of compound La080: Referring to the synthesis and purification method of compound La001, the corresponding raw materials were changed to obtain the target compound La080. Mass spectrum: 398.48 (M+H).

[0084] Compound Ir(La080) 2 Synthesis of Lb005: JPEG0007600403000027.jpg37170

[0085] Synthesis of compound Ir(La080)-1: Referring to the synthesis and purification method of compound Ir(La001)-1, all that is needed is to change the corresponding raw materials, and the obtained compound Ir(La080)-1 was used directly in the next step without purification.

[0086] Compound Ir(La080) 2 Synthesis of Lb005: Compound Ir(La001) 2 Referring to the synthesis and purification method of Lb005, we only need to change the corresponding raw materials, and the compound Ir(La080) 2 A red solid was obtained as Lb005 (1.87g, yield: 43.22%). 1.87g of Ir(La080) 2 After the crude product of Lb005 was purified by sublimation, the sublimed pure Ir(La080) 2 Lb005 was obtained (1.04 g, yield: 55.61%). Mass spectrum: 1197.49 (M+H). 1 H NMR (400 MHz, CDCl 3 ) δ 8.77 (d, J = 8.6 Hz, 2H), 8.35 (d, J = 6.6Hz, 2H), 7.82(d, J = 7.4 Hz, 2H), 7.59 (d, J = 6.5 Hz, 2H), 7.54 - 7.44 (m, 4H), 7.43 - 7.34 (m, 4H), 7.31 (d, J = 7.3 Hz, 2H), 4.83 (s, 1H), 2.83 (s, 4H), 2.19 - 2.08 (m, 2H), 1.86 (s, 6H), 1.27 (m, 4H), 1.01 (m, 4H), 0.94 (s, 12H), 0.85 (s, 18H).

[0087] Synthesis of compound La106: JPEG0007600403000028.jpg44170

[0088] Synthesis of compound 15 Referring to the synthesis and purification method of compound 3, the corresponding raw materials were changed to obtain the target compound 15. Mass spectrum: 250.71 (M+H).

[0089] Synthesis of compound La106: Referring to the synthesis and purification method of compound La001, the corresponding raw materials were changed to obtain the target compound La106. Mass spectrum: 396.47 (M+H).

[0090] Compound Ir(La106) 2 Synthesis of Lb005: JPEG0007600403000029.jpg34170

[0091] Synthesis of compound Ir(La106)-1: Referring to the synthesis and purification method of compound Ir(La001)-1, all that is needed is to change the corresponding raw materials, and the obtained compound Ir(La106)-1 was directly used in the next step without purification.

[0092] Compound Ir(La106) 2 Synthesis of Lb005: Compound Ir(La001) 2 Referring to the synthesis and purification method of Lb005, we only need to change the corresponding raw materials, and the compound Ir(La106) 2 A red solid was obtained as Lb005 (2.06g, yield: 45.77%). 2.06g of Ir(La106) 2 After the crude product of Lb005 was purified by sublimation, the sublimed pure Ir(La106) 2 Lb005 was obtained (1.28 g, yield: 62.13%). Mass spectrum: 1193.46 (M+H). 1 H NMR (400 MHz, CDCl 3) δ 8.76 (d, J = 8.6 Hz, 2H), 8.34 (d, J = 6.6Hz, 2H), 7.80(d, J = 7.4 Hz, 2H), 7.57 (d, J = 6.5 Hz, 2H), 7.52 - 7.42 (m, 4H), 7.41- 7.31 (m, 4H), 7.28 (d, J = 7.3 Hz, 2H), 4.83 (s, 1H), 2.19 - 2.08 (m, 2H), 1.86 (s, 6H), 1.62 (m, 4H), 1.43 (m, 8H), 1.31 (m, 4H), 1.24 (m, 4H), 1.01 (m, 6H), 0.94 (s, 12H).

[0093] Synthesis of compound La171: JPEG0007600403000030.jpg46170

[0094] Synthesis of compound 17 Referring to the synthesis and purification method of compound 3, the corresponding raw materials were changed to obtain the target compound 17. Mass spectrum: 266.71 (M+H).

[0095] Synthesis of compound La171: Referring to the synthesis and purification method of compound La001, the corresponding raw materials were changed to obtain the target compound La171. Mass spectrum: 412.47 (M+H). Compound Ir(La171) 2 Synthesis of Lb005: JPEG0007600403000031.jpg36170

[0096] Synthesis of compound Ir(La171)-1: Referring to the synthesis and purification method of compound Ir(La001)-1, all that is required is to change the corresponding raw materials, and the obtained compound Ir(La171)-1 was directly used in the next step without purification.

[0097] Compound Ir(La171) 2 Synthesis of Lb005: Compound Ir(La001) 2 Referring to the synthesis and purification method of Lb005, we only need to change the corresponding raw materials, and the compound Ir(La171) 2 A red solid was obtained as Lb005 (1.82 g, yield: 34.87%). 1.82 g of Ir(La171) 2 After the crude product of Lb005 was purified by sublimation, the sublimed pure Ir(La171) 2 Lb005 was obtained (1.01 g, yield: 55.49%). Mass spectrum: 1225.46 (M+H). 1 H NMR (400 MHz, CDCl 3 ) δ 8.81 (d, J = 8.6 Hz, 2H), 8.37 (d, J = 6.6Hz, 2H), 7.86(d, J = 7.4 Hz, 2H), 7.61 (d, J = 6.5 Hz, 2H), 7.58 - 7.47 (m, 4H), 7.44- 7.33 (m, 4H), 7.31 (d, J = 7.3 Hz, 2H), 4.82 (s, 1H), 2.23 - 2.14(m, 2H), 1.88 (s, 6H), 1.64 (m, 4H), 1.51 (m, 4H), 1.41(m, 6H), 1.27 (m, 8H), 1.07 - 0.89 (m, 16H).

[0098] Application example: Manufacturing of organic electroluminescence devices A 50mm x 50mm x 1.0mm glass substrate with an ITO (70 A゜ / 1000 A゜ / 110 A゜) anode electrode was ultrasonically cleaned in ethanol for 10 minutes, then dried at 150 degrees, and then vacuum-cleaned with N 2The glass substrate was treated with Plasma for 30 minutes. The cleaned glass substrate was placed on the substrate holder of a vacuum deposition apparatus. First, on the surface on which the anode electrode wire was located, compounds HTM1 and P-dopant (ratio 97%:3%) were evaporated in co-evaporation mode to cover the electrode, forming a thin film with a thickness of 100 A°. Immediately after that, a layer of HTM1 was evaporated to form a thin film with a thickness of about 1720 A°. Next, a layer of HTM2 was evaporated on the HTM1 thin film to form a thin film with a thickness of 100 A°. Then, on the HTM2 film layer, host material 1, host material 2, and doping compound (ratio 48.5%:48.5%:3%, comparative compound X, compound of the present invention) were evaporated again in co-evaporation mode. The film thickness was 400 A°, and the ratio of host material to doping material was 90%:10%. On the light-emitting layer, ETL:LiQ (350 A°, ratio 50%:50%) was evaporated in co-evaporation mode. Then, Yb (10 Å) was evaporated onto the electron transport layer material. Finally, a layer of metallic Ag (150 Å) was evaporated as an electrode.

[0099] JPEG0007600403000032.jpg178170

[0100] JPEG0007600403000033.jpg157170

[0101] Evaluation: A device performance test was performed on the above device. In each example and comparative example, a constant current source (Keithley 2400) was used to apply a constant current density to the light-emitting element, and the emission spectrum was measured using a spectroradiometer (CS 2000). At the same time, the voltage value was measured, and the time (LT90) until the brightness reached 90% of the initial brightness was tested. The results are as follows. The current efficiency and device life were calculated by taking the value of Comparative Compound 5 as 100%.

[0102] JPEG0007600403000034.jpg150170 Comparing the data in the above table, it can be seen that the organic electroluminescent devices using the compounds of the present invention as dopants show superior performance in terms of driving voltage, luminous efficiency and device lifetime compared to the comparative compounds in devices of the same color code.

[0103] Comparison of emission wavelengths in dichloromethane solution: Defined as follows. -5 The emission wavelength was measured using a Hitachi F2700 fluorescence spectrophotometer to obtain the emission wavelength at which the emission peak was maximized. The test results are as follows: JPEG0007600403000035.jpg198170 Comparing the data in the above table, it can be seen that the metal iridium complex of the present invention has a large red shift compared with the comparative compounds, and can meet the industrial requirements for deep red light, especially the BT2020 color gamut.

[0104] Sublimation temperature comparison: The sublimation temperature is defined as the temperature corresponding to a deposition rate of 1 angstrom / sec at a vacuum of 10-7 Torr. The test results are as follows: JPEG0007600403000036.jpg193159

[0105] From a comparison of the data in the above tables, it can be seen that the metal iridium complexes of the present invention have a lower sublimation temperature, which is beneficial for industrial applications.

[0106] The present invention unexpectedly provides better device luminous efficiency and improved lifetime compared with the prior art due to the special combination of substituents, and provides lower sublimation temperature and more saturated red emission.The above results show that the compounds of the present invention have the advantages of low sublimation temperature, high optical and electrochemical stability, high color saturation, high luminous efficiency, long device lifetime, etc., and can be used in organic electroluminescent devices.In particular, as a red-emitting dopant, they have potential applications in the OLED industry, especially in displays, lighting, and automotive taillights. The compounds of the present invention have advantages such as high optical and electrochemical stability, high saturation, high luminous efficiency, long device life, etc., and can be used in organic electroluminescence devices, especially as red emitting dopants, and have potential applications in the OLED industry.

Claims

1. A metal complex represented by the general formula Ir(La)(Lb)(Lc), represented by the formula (1): In formula (1), is the ligand La, X is selected from the group consisting of O, S, and Se; R １ -R ５ are independently selected from hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms in the main chain, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 carbon atoms in the main chain, a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, a nitrile, and an isonitrile; R １ -R ５ at least one of the groups is F, and the other group is a substituted or unsubstituted alkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 main chain carbon atoms, or a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, R ６ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms in the main chain, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, or a substituted or unsubstituted heteroalkyl group having 1 to 10 carbon atoms in the main chain, the heteroatom of the heteroalkyl group or heterocycloalkyl group is at least one of S, O, and N; Lb is represented by the formula (2): In formula (2), the position of the dashed line represents the position at which the metal Ir is bonded. R ａ -R ｇ are independently selected from hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 10 main chain carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 main chain carbon atoms, and a substituted or unsubstituted heterocycloalkyl group having 3 to 20 ring carbon atoms, or R ａ , R ｂ , and R ｃ are linked to form an aliphatic ring structure, and R ｅ , R ｆ , and R ｇ are linked to form an aliphatic ring structure, the substitution is with deuterium, F, Cl, Br, a C1-C4 alkyl group, a C3-C6 cycloalkyl group, a nitrile, or an isonitrile; Lc and La have the same structure, (La) ２ A metal complex having an Ir(Lb) structure.

2. R ａ , R ｂ , and R ｃ are R ｅ , R ｆ、 and R ｇ The metal complex according to claim 1, wherein

3. R ａ , R ｂ , R ｃ , R ｅ , R ｆ、 and R ｇ are independently selected from hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms in the main chain, and a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, or R ａ , R ｂ , and R ｃ are linked to form an aliphatic ring structure, and R ｅ , R ｆ , and R ｇ are linked to form an aliphatic ring structure, The substitution is by deuterium, F, Cl, Br, a C1-C4 alkyl group, or a C3-C6 cycloalkyl group; R ｄ is selected from the group consisting of hydrogen, deuterium, halogen, and a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms in the main chain.

4. 2. The metal complex according to claim 1, wherein Lb is represented by any one of the following formulas:

5. R ６ is a substituted or unsubstituted alkyl group having 4 or less main chain carbon atoms, or a substituted or unsubstituted cycloalkyl group having 6 or less ring-forming carbon atoms.

6. The F is R ５ and X is an oxygen atom O.

7. R １ -R ５ the remaining three are all hydrogen; and one of the above is F, the other is a substituted or unsubstituted alkyl group having 4 or less main chain carbon atoms or a substituted or unsubstituted cycloalkyl group having 6 or less ring carbon atoms; and the remaining three are all hydrogen.

8. R １ -R ５ The metal complex according to claim 7, characterized in that one of the above is F, another is a branched alkyl group having up to 4 main chain carbon atoms with C1-C4 alkyl group substitution, and the remaining three are all hydrogen.

9. The metal complex according to claim 1, wherein La is represented by any one of the following formulas:

10. 10. An electroluminescent device comprising a cathode, an anode, and an organic layer disposed between the cathode and the anode, wherein at least one of the organic layers comprises the metal complex according to claim 1.

11. The electroluminescent device according to claim 10, wherein the organic layer is an emitting layer, and the metal complex according to any one of claims 1 to 9 is used as a red emitting doping material of the emitting layer, or the organic layer is a hole injection layer, and the metal complex according to any one of claims 1 to 9 is used as a hole injection material of the hole injection layer.

12. A ligand La having the structure shown in the formula: Ligand La, characterized in that R1-R6 and X are as defined in any one of claims 1 to 8.

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