Organic electroluminescent material and device thereof

Abstract

Organic electroluminescent materials and devices thereof are disclosed. The organic electroluminescent material is a metal complex containing a La ligand with a structure shown in a formula 1, and the metal complex can be used as a luminescent material in an electroluminescent device. The novel compounds can be applied to electroluminescent devices, show more excellent performance, can provide more saturated luminescence, higher luminous efficiency and narrower half-peak width, and can obviously improve the comprehensive performance of the devices. The invention also discloses an electroluminescent device containing the metal complex and a compound combination containing the metal complex.

Description

Technical Field

[0001] The present invention relates to compounds for use in organic electronic devices, such as organic light-emitting devices. More particularly, it relates to a compound comprising L having a structure of Formula 1 a The invention relates to a metal complex of a ligand, and an electroluminescent device and a compound combination comprising the metal complex. Background Art

[0002] Organic electronic devices include but are not limited to the following categories: organic light emitting diodes (OLEDs), organic field effect transistors (O-FETs), organic light emitting transistors (OLETs), organic photovoltaic devices (OPVs), dye-sensitized solar cells (DSSCs), organic optical detectors, organic photoreceptors, organic field effect devices (OFQDs), light emitting electrochemical cells (LECs), organic laser diodes and organic plasmonic light emitting devices.

[0003] In 1987, Tang and Van Slyke of Eastman Kodak reported a double-layer organic electroluminescent device, which included an arylamine hole transport layer and a tri-8-hydroxyquinoline-aluminum layer as an electron transport layer and a light-emitting layer (Applied Physics Letters, 1987, 51 (12): 913-915). Once a bias voltage is applied to the device, green light is emitted from the device. This invention laid the foundation for the development of modern organic light-emitting diodes (OLEDs). The most advanced OLEDs can include multiple layers, such as charge injection and transport layers, charge and exciton blocking layers, and one or more light-emitting layers between the cathode and the anode. Since OLEDs are self-luminous solid-state devices, they offer great potential for display and lighting applications. In addition, the inherent properties of organic materials, such as their flexibility, can make them very suitable for special applications, such as on flexible substrates.

[0004] OLEDs can be divided into three different types based on their light emission mechanism. The OLED invented by Tang and van Slyke is a fluorescent OLED. It uses only singlet light emission. The triplet generated in the device is wasted through non-radiative decay channels. Therefore, the internal quantum efficiency (IQE) of fluorescent OLEDs is only 25%. This limitation has hindered the commercialization of OLEDs. In 1997, Forrest and Thompson reported phosphorescent OLEDs, which used triplet light emission from heavy metals containing complexes as emitters. Therefore, singlet and triplet states can be harvested, achieving 100% IQE. Due to its high efficiency, the discovery and development of phosphorescent OLEDs directly contributed to the commercialization of active matrix OLEDs (AMOLEDs). Recently, Adachi achieved high efficiency through thermally activated delayed fluorescence (TADF) of organic compounds. These emitters have a small singlet-triplet gap, making it possible for excitons to return from triplet to singlet. In TADF devices, triplet excitons can generate singlet excitons through reverse intersystem crossing, resulting in high IQE.

[0005] OLEDs can also be classified into small molecule and polymer OLEDs based on the form of the material used. Small molecules are any organic or organometallic material that is not a polymer. Small molecules can have a large molecular weight as long as they have a precise structure. Dendrimers with well-defined structures are considered small molecules. Polymer OLEDs include conjugated polymers and non-conjugated polymers with pendant luminescent groups. Small molecule OLEDs can become polymer OLEDs if post-polymerization occurs during the manufacturing process.

[0006] There are various OLED manufacturing methods. Small molecule OLEDs are usually manufactured by vacuum thermal evaporation. Polymer OLEDs are manufactured by solution methods such as spin coating, inkjet printing, and nozzle printing. Small molecule OLEDs can also be manufactured by solution methods if the material can be dissolved or dispersed in a solvent.

[0007] The emission color of OLED can be achieved by the structural design of the luminescent material. OLED can include one luminescent layer or multiple luminescent layers to achieve the desired spectrum. Green, yellow and red OLEDs, phosphorescent materials have been successfully commercialized. Blue phosphorescent devices still have problems such as blue unsaturation, short device life and high operating voltage. Commercial full-color OLED displays usually adopt a hybrid strategy, using blue fluorescence and phosphorescent yellow, or red and green. At present, the efficiency of phosphorescent OLEDs decreases rapidly under high brightness conditions, which is still a problem. In addition, it is expected to have a more saturated emission spectrum, higher efficiency and longer device life.

[0008] The applicant disclosed in the previous US20200251666A1 a ligand having the following structure: wherein at least one of X1-X8 is selected from C-CN, further disclosed is an iridium complex having the following structure Its application in organic electroluminescent devices can improve device performance and color saturation. Although it has reached a relatively high level in the industry, there is still room for improvement. However, the application only discloses a metal complex in which R4 is an aryl substituent of phenyl and its application in the device, and does not disclose or pay attention to the effect of introducing an aryl or heteroaryl group as specified in the present application into the metal complex on the device performance.

[0009] In the previous US20200091442A1, the applicant disclosed a ligand having the following structure: Further disclosed is an iridium complex having the structure In this application, fluorine at a specific position of the ligand can improve the performance of the material, including improving the device life and increasing thermal stability, but there is still room for improvement. In this application, only metal complexes with R4 being an aryl substituent of phenyl and their applications in devices are disclosed, and the effect of introducing an aryl or heteroaryl group as specified in this application into the metal complex on the device performance is not disclosed or concerned. Summary of the invention

[0010] The present invention aims to provide a series of L having a structure of Formula 1 a Ligand-metal complexes are proposed to solve at least some of the above problems.

[0011] According to one embodiment of the present invention, a metal complex is disclosed, which comprises a metal M and a ligand L coordinated with the metal M. a , where L a Having a structure represented by Formula 1:

[0012]

[0013] In formula 1,

[0014] The metal M is selected from metals with a relative atomic mass greater than 40;

[0015] Cy is selected, at each occurrence, identically or differently, from a substituted or unsubstituted aromatic ring having 6 to 24 ring atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 24 ring atoms, or a combination thereof;

[0016] X is selected from the group consisting of O, S, Se, NR', CR'R', SiR'R' and GeR'R'; when two R' exist at the same time, the two R' are the same or different;

[0017] X1-X8 are selected from C, CR in the same or different manner at each occurrence x or N; at least one of X1-X4 is C and is connected to the Cy;

[0018] X1, X2, X3 or X4 is connected to the metal M through a metal-carbon bond or a metal-nitrogen bond;

[0019] At least one of X1-X8 is CR x , and the R x is cyano or fluorine;

[0020] At least one of X1-X8 is CR x , and R x Ar has a structure represented by Formula 2:

[0021]

[0022] a is selected from 0, 1, 2, 3, 4 or 5;

[0023] R a1 and R a2 Each occurrence, identically or differently, indicates mono-, poly- or non-substitution;

[0024] Ring Ar1 and ring Ar2 are identically or differently selected from aromatic rings having 6-30 ring atoms, heteroaromatic rings having 5-30 ring atoms, or combinations thereof at each occurrence; and the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8;

[0025] R', R x , R a1 and R a2 The group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0026] “*” indicates the connection position of formula 2;

[0027] The adjacent substituents R', R x , R a1 , R a2 Can optionally be linked to form a ring.

[0028] According to another embodiment of the present invention, an electroluminescent device is also disclosed, comprising:

[0029] anode,

[0030] cathode,

[0031] and an organic layer disposed between the anode and the cathode, wherein the organic layer comprises the metal complex described in the above embodiment.

[0032] According to another embodiment of the present invention, a compound combination is also disclosed, which comprises the metal complex described in the above embodiment.

[0033] The present invention discloses a series of L having a structure of Formula 1 a The metal complex of the ligand can be used as a luminescent material in an electroluminescent device. These novel metal complexes can be applied to electroluminescent devices, can provide more saturated luminescence, higher luminous efficiency, narrower half-peak width, and can significantly improve the overall performance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of an electroluminescent device that may contain combinations of metal complexes and compounds disclosed herein.

[0035] Figure 2 is a schematic diagram of another electroluminescent device that may contain the metal complexes and compound combinations disclosed herein. DETAILED DESCRIPTION

[0036] OLEDs can be manufactured on a variety of substrates, such as glass, plastic, and metal. Figure 1 An organic light-emitting device 100 is shown schematically and non-limitingly. The figure is not necessarily drawn to scale, and some layer structures in the figure may be omitted as needed. The device 100 may include a substrate 101, an anode 110, a hole injection layer 120, a hole transport layer 130, an electron blocking layer 140, a light-emitting layer 150, a hole blocking layer 160, an electron transport layer 170, an electron injection layer 180 and a cathode 190. The device 100 can be manufactured by depositing the described layers in sequence. The properties and functions of each layer and exemplary materials are described in more detail in columns 6-10 of U.S. Patent No. 7,279,704 B2, the entire contents of which are incorporated herein by reference.

[0037] There are more examples of each of these layers. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Patent No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F4-TCNQ at a molar ratio of 50:1, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety. An example of a host material is disclosed in U.S. Patent No. 6,303,238 to Thompson et al., which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1:1, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety. U.S. Patent Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entirety, disclose examples of cathodes including composite cathodes having a thin layer of metal such as Mg:Ag with an overlying transparent, conductive, sputter-deposited ITO layer. The principles and use of barrier layers are described in more detail in U.S. Patent No. 6,097,147 and U.S. Patent Application Publication No. 2003 / 0230980, which are incorporated by reference in their entirety. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated by reference in its entirety. A description of protective layers can be found in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated by reference in its entirety.

[0038] The above layered structure is provided by way of non-limiting example. The functions of an OLED can be achieved by combining the various layers described above, or some layers can be omitted entirely. It can also include other layers not explicitly described. Within each layer, a single material or a mixture of multiple materials can be used to achieve optimal performance. Any functional layer can include several sublayers. For example, a light-emitting layer can have two layers of different light-emitting materials to achieve a desired light-emitting spectrum.

[0039] In one embodiment, an OLED may be described as having an "organic layer" disposed between a cathode and an anode. The organic layer may include one or more layers.

[0040] OLED also requires encapsulation layers, such as Figure 2 The organic light emitting device 200 is schematically and non-limitingly shown. Figure 1The difference is that an encapsulation layer 102 may also be included on the cathode 190 to prevent harmful substances from the environment, such as moisture and oxygen. Any material that can provide an encapsulation function can be used as an encapsulation layer, such as glass or an organic-inorganic hybrid layer. The encapsulation layer should be placed directly or indirectly on the outside of the OLED device. Multilayer thin film encapsulation is described in U.S. Patent No. 7,968,146 B2, the entire contents of which are incorporated herein by reference.

[0041] Devices manufactured according to embodiments of the present invention can be incorporated into various consumer products having one or more electronic component modules (or units) of the device. Some examples of these consumer products include flat panel displays, monitors, medical monitors, televisions, billboards, lights for indoor or outdoor lighting and / or signaling, heads-up displays, fully or partially transparent displays, flexible displays, smart phones, tablet computers, tablet phones, wearable devices, smart watches, laptop computers, digital cameras, camcorders, viewfinders, micro displays, 3-D displays, vehicle displays, and taillights.

[0042] The materials and structures described herein may also be used in other organic electronic devices listed above.

[0043] As used herein, "top" means farthest from the substrate, while "bottom" means closest to the substrate. Where a first layer is described as being "disposed" "on" a second layer, the first layer is disposed farther from the substrate. Unless it is specified that the first layer is "in contact with" the second layer, other layers may be present between the first and second layers. For example, a cathode may be described as being "disposed" "on" an anode even though various organic layers are present between the cathode and the anode.

[0044] As used herein, "solution processable" means capable of being dissolved, dispersed or transported in and / or deposited from a liquid medium in the form of a solution or suspension.

[0045] A ligand may be referred to as "photoactive" when it is believed that the ligand directly contributes to the photoactive property of the emissive material. A ligand may be referred to as "ancillary" when it is believed that the ligand does not contribute to the photoactive property of the emissive material, but the ancillary ligand may alter the properties of the photoactive ligand.

[0046] It is believed that the internal quantum efficiency (IQE) of fluorescent OLEDs can exceed the 25% spin-statistical limit through delayed fluorescence. Delayed fluorescence can generally be divided into two types, namely P-type delayed fluorescence and E-type delayed fluorescence. P-type delayed fluorescence is generated by triplet-triplet annihilation (TTA).

[0047] On the other hand, E-type delayed fluorescence does not rely on the collision of two triplets, but on the conversion between triplet and singlet excited state. Compounds capable of producing E-type delayed fluorescence need to have a very small single-triplet gap for the conversion between energy states. Thermal energy can activate the transition from triplet back to singlet. This type of delayed fluorescence is also called thermally activated delayed fluorescence (TADF). The notable feature of TADF is that the delayed component increases with increasing temperature. If the reverse intersystem crossing (RISC) rate is fast enough to minimize the non-radiative decay by triplet, the fraction of backfilling singlet excited state may reach 75%. The total singlet fraction can be 100%, far exceeding the 25% of the spin statistics of the excitons generated by electricity.

[0048] The E-type delayed fluorescence feature can be seen in an exciplex system or a single compound. Without being bound by theory, it is believed that the E-type delayed fluorescence requires the luminescent material to have a small singlet-triplet energy gap (ΔE S-T ). Organic non-metal-containing donor-acceptor luminescent materials may be able to achieve this. The emission of these materials is usually characterized by donor-acceptor charge transfer (CT) type emission. The spatial separation of the HOMO and LUMO in these donor-acceptor type compounds usually produces a small ΔE S-T These states may include CT states. Generally, donor-acceptor light-emitting materials are constructed by linking an electron donor moiety (eg, an amino group or a carbazole derivative) to an electron acceptor moiety (eg, a six-membered aromatic ring containing N).

[0049] Definition of Substituent Terms

[0050] Halogen or halide - as used herein includes fluorine, chlorine, bromine and iodine.

[0051] Alkyl - as used herein, includes straight chain and branched alkyl groups. The alkyl group may be an alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 1 to 12 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, neopentyl, 1-methylpentyl, 2-methylpentyl, 1-pentylhexyl, 1-butylpentyl, 1-heptyloctyl, 3-methylpentyl. Among the above, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl and n-hexyl are preferred. In addition, the alkyl group may be optionally substituted.

[0052] Cycloalkyl - as used herein, includes cyclic alkyl. Cycloalkyl can be a cycloalkyl having 3 to 20 ring carbon atoms, preferably a cycloalkyl having 4 to 10 carbon atoms. Examples of cycloalkyl include cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4,4-dimethylcyclohexyl, 1-adamantyl, 2-adamantyl, 1-norbornyl, 2-norbornyl, etc. Among the above, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4,4-dimethylcyclohexyl are preferred. In addition, cycloalkyl can be optionally substituted.

[0053] Heteroalkyl - As used herein, a heteroalkyl group comprises one or more carbons in an alkyl chain substituted with a heteroatom selected from the group consisting of a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, a phosphorus atom, a silicon atom, a germanium atom and a boron atom. The heteroalkyl group may be a heteroalkyl group having 1 to 20 carbon atoms, preferably a heteroalkyl group having 1 to 10 carbon atoms, and more preferably a heteroalkyl group having 1 to 6 carbon atoms. Examples of heteroalkyl include methoxymethyl, ethoxymethyl, ethoxyethyl, methylthiomethyl, ethylthiomethyl, ethylthioethyl, methoxymethoxymethyl, ethoxymethoxymethyl, ethoxyethoxyethyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, mercaptomethyl, mercaptoethyl, mercaptopropyl, aminomethyl, aminoethyl, aminopropyl, dimethylaminomethyl, trimethylgermanylmethyl, trimethylgermanylethyl, trimethylgermanylisopropyl, dimethylethylgermanylmethyl, dimethylisopropylgermanylmethyl, tert-butyldimethylgermanylmethyl, triethylgermanylmethyl, triethylgermanylethyl, triisopropylgermanylmethyl, triisopropylgermanylethyl, trimethylsilylmethyl, trimethylsilylethyl, trimethylsilylisopropyl, triisopropylsilylmethyl, triisopropylsilylethyl. In addition, heteroalkyl may be optionally substituted.

[0054] Alkenyl - as used herein, encompasses straight chain, branched and cyclic olefin groups. Alkenyl can be an alkenyl containing 2 to 20 carbon atoms, preferably an alkenyl having 2 to 10 carbon atoms. Examples of alkenyl include vinyl, propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl, 1-methylvinyl, styryl, 2,2-diphenylvinyl, 1,2-diphenylvinyl, 1-methylallyl, 1,1-dimethylallyl, 2-methylallyl, 1-phenylallyl, 2-phenylallyl, 3-phenylallyl, 3,3-diphenylallyl, 1,2-dimethylallyl, 1-phenyl-1-butenyl, 3-phenyl-1-butenyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cycloheptenyl, cycloheptatrienyl, cyclooctenyl, cyclooctatetraenyl and norbornenyl. Additionally, alkenyl groups may be optionally substituted.

[0055] Alkynyl - as used herein, encompasses straight chain alkynyl. Alkynyl may be an alkynyl containing 2 to 20 carbon atoms, preferably an alkynyl having 2 to 10 carbon atoms. Examples of alkynyl include ethynyl, propynyl, propargyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3,3-dimethyl-1-butynyl, 3-ethyl-3-methyl-1-pentynyl, 3,3-diisopropyl-1-pentynyl, phenylethynyl, phenylpropynyl, etc. Among the above, ethynyl, propynyl, propargyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, phenylethynyl, etc. are preferred. In addition, alkynyl may be optionally substituted.

[0056] Aryl or aromatic group - As used herein, both non-fused and fused systems are contemplated. The aryl group may be an aryl group having 6 to 30 carbon atoms, preferably an aryl group having 6 to 20 carbon atoms, and more preferably an aryl group having 6 to 12 carbon atoms. Examples of aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenanthrene, fluorene, pyrene, Perylene and azulene, preferably phenyl, biphenyl, terphenyl, triphenylene, fluorene and naphthalene. Examples of non-condensed aryl groups include phenyl, biphenyl-2-yl, biphenyl-3-yl, biphenyl-4-yl, p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p-tolyl, p-(2-phenylpropyl)phenyl, 4'-methylbiphenyl, 4"-tert-butyl-p-terphenyl-4-yl, o-cumyl, m-cumyl, p-cumyl, 2,3-xylyl, 3,4-xylyl, 2,5-xylyl, mesityl and m-quadrenyl. In addition, the aryl group may be optionally substituted.

[0057] Heterocyclic or heterocyclic - as used herein, non-aromatic cyclic groups are contemplated. Non-aromatic heterocyclic groups include saturated heterocyclic groups having 3-20 ring atoms and unsaturated non-aromatic heterocyclic groups having 3-20 ring atoms, wherein at least one ring atom is selected from the group consisting of nitrogen atoms, oxygen atoms, sulfur atoms, selenium atoms, silicon atoms, phosphorus atoms, germanium atoms and boron atoms, and preferred non-aromatic heterocyclic groups are those having 3 to 7 ring atoms, including at least one heteroatom such as nitrogen, oxygen, silicon or sulfur. Examples of non-aromatic heterocyclic groups include oxirane, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxopentanyl, dioxanyl, aziridinyl, dihydropyrrolyl, tetrahydropyrrolyl, piperidinyl, oxazolidinyl, morpholinyl, piperazinyl, oxepinyl, thiepinyl, azepine and tetrahydrothioxolyl. Additionally, the heterocyclyl group may be optionally substituted.

[0058] Heteroaryl - As used herein, non-fused and fused heteroaromatic groups may contain 1 to 5 heteroatoms, wherein at least one heteroatom is selected from the group consisting of nitrogen, oxygen, sulfur, selenium, silicon, phosphorus, germanium and boron atoms. Heteroaryl also refers to heteroaryl. The heteroaryl may be a heteroaryl having 3 to 30 carbon atoms, preferably a heteroaryl having 3 to 20 carbon atoms, and more preferably a heteroaryl having 3 to 12 carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indole, carbazole, pyridine, indole, pyrrolopyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indenozine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, In some embodiments, the heteroaryl group is substituted with 1,2-azaborine, 1,3-azaborine, 1,4-azaborine, borazole and its aza analogs. In some embodiments, the heteroaryl group is substituted with 1,2-azaborine, 1,3-azaborine, 1,4-azaborine, borazole and its aza analogs. In some embodiments, the heteroaryl group is substituted with 1,2-azaborine, 1,3-azaborine, 1,4-azaborine, borazole and its aza analogs. In addition, the heteroaryl group may be optionally substituted.

[0059] Alkoxy-as used herein, represented by -O-alkyl, -O-cycloalkyl, -O-heteroalkyl or -O-heterocyclyl. Examples and preferred examples of alkyl, cycloalkyl, heteroalkyl and heterocyclyl are the same as described above. Alkoxy can be an alkoxy having 1 to 20 carbon atoms, preferably an alkoxy having 1 to 6 carbon atoms. Examples of alkoxy include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, tetrahydrofuranyloxy, tetrahydropyranyloxy, methoxypropyloxy, ethoxyethyloxy, methoxymethyloxy and ethoxymethyloxy. In addition, alkoxy can be optionally substituted.

[0060] Aryloxy - as used herein, represented by -O-aryl or -O-heteroaryl. Examples and preferred examples of aryl and heteroaryl are the same as above. Aryloxy can be an aryloxy having 6 to 30 carbon atoms, preferably an aryloxy having 6 to 20 carbon atoms. Examples of aryloxy include phenoxy and biphenyloxy. In addition, aryloxy can be optionally substituted.

[0061] Aralkyl - as used herein, encompasses aryl-substituted alkyl groups. Aralkyl groups may be aralkyl groups having 7 to 30 carbon atoms, preferably aralkyl groups having 7 to 20 carbon atoms, and more preferably aralkyl groups having 7 to 13 carbon atoms. Examples of aralkyl groups include benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl, 2-phenylisopropyl, phenyl tert-butyl, α-naphthylmethyl, 1-α-naphthyl-ethyl, 2-α-naphthylethyl, 1-α-naphthylisopropyl, 2-α-naphthylisopropyl, β-naphthylmethyl, 1-β-naphthyl-ethyl, 2-β-naphthyl-ethyl, 1-β-naphthylisopropyl, 2-β-naphthylisopropyl, p-methylbenzyl, m-methylbenzyl, substituted alkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl, arylalkyl,

[0062] Alkylsilyl - As used herein, alkyl substituted silicon groups are contemplated. The alkylsilyl group may be an alkylsilyl group having 3-20 carbon atoms, preferably an alkylsilyl group having 3 to 10 carbon atoms. Examples of alkylsilyl groups include trimethylsilyl, triethylsilyl, methyldiethylsilyl, ethyldimethylsilyl, tripropylsilyl, tributylsilyl, triisopropylsilyl, methyldiisopropylsilyl, dimethylisopropylsilyl, tri-tert-butylsilyl, triisobutylsilyl, dimethyltert-butylsilyl, methyldi-tert-butylsilyl. In addition, the alkylsilyl group may be optionally substituted.

[0063] Arylsilyl - as used herein, encompasses at least one aryl-substituted silicon group. The arylsilyl group may be an arylsilyl group having 6 to 30 carbon atoms, preferably an arylsilyl group having 8 to 20 carbon atoms. Examples of arylsilyl groups include triphenylsilyl, phenyldiphenylsilyl, diphenylbiphenylsilyl, phenyldiethylsilyl, diphenylethylsilyl, phenyldimethylsilyl, diphenylmethylsilyl, phenyldiisopropylsilyl, diphenylisopropylsilyl, diphenylbutylsilyl, diphenylisobutylsilyl, diphenyltert-butylsilyl. In addition, the arylsilyl group may be optionally substituted.

[0064] Alkylgermanyl - As used herein, alkyl substituted germanyl is contemplated. The alkylgermanyl may be an alkylgermanyl having 3-20 carbon atoms, preferably an alkylgermanyl having 3 to 10 carbon atoms. Examples of alkylgermanyl include trimethylgermanyl, triethylgermanyl, methyldiethylgermanyl, ethyldimethylgermanyl, tripropylgermanyl, tributylgermanyl, triisopropylgermanyl, methyldiisopropylgermanyl, dimethylisopropylgermanyl, tri-tert-butylgermanyl, triisobutylgermanyl, dimethyltert-butylgermanyl, methyldi-tert-butylgermanyl. In addition, the alkylgermanyl may be optionally substituted.

[0065] Arylgermanyl - as used herein, encompasses germanyl substituted with at least one aryl or heteroaryl group. The arylgermanyl may be an arylgermanyl having 6 to 30 carbon atoms, preferably an arylgermanyl having 8 to 20 carbon atoms. Examples of arylgermanyl include triphenylgermanyl, phenyldibiphenylgermanyl, diphenylbiphenylgermanyl, phenyldiethylgermanyl, diphenylethylgermanyl, phenyldimethylgermanyl, diphenylmethylgermanyl, phenyldiisopropylgermanyl, diphenylisopropylgermanyl, diphenylbutylgermanyl, diphenylisobutylgermanyl, diphenyltert-butylgermanyl. In addition, the arylgermanyl may be optionally substituted.

[0066] The term "aza" in azadibenzofuran, azadibenzothiophene, etc. means that one or more CH groups in the corresponding aromatic fragment are replaced by a nitrogen atom. For example, azatriphenylene includes dibenzo[f,h]quinoxaline, dibenzo[f,h]quinoline and other analogs having two or more nitrogens in the ring system. Other nitrogen analogs of the above-mentioned aza derivatives can be easily thought of by those of ordinary skill in the art, and all such analogs are determined to be included in the terms described herein.

[0067] In the present disclosure, unless otherwise defined, when any one of the terms in the group consisting of substituted alkyl, substituted cycloalkyl, substituted heteroalkyl, substituted heterocyclyl, substituted aralkyl, substituted alkoxy, substituted aryloxy, substituted alkenyl, substituted alkynyl, substituted aryl, substituted heteroaryl, substituted alkylsilyl, substituted arylsilyl, substituted alkylgermanyl, substituted arylgermanyl, substituted amino, substituted acyl, substituted carbonyl, substituted The carboxylic acid group, substituted ester group, substituted sulfinyl group, refers to any one of an alkyl group, a cycloalkyl group, a heteroalkyl group, a heterocyclic group, an aralkyl group, an alkoxy group, an aryloxy group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an alkylsilyl group, an arylsilyl group, an alkylgermanyl group, an arylgermanyl group, an amino group, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a sulfinyl group, a sulfonyl group and a phosphino group, which may be substituted by one or more deuterium, a halogen, an unsubstituted alkyl group having 1 to 20 carbon atoms, an unsubstituted alkyl group having 3 to 20 carbon atoms. cycloalkyl having ring carbon atoms, unsubstituted heteroalkyl having 1 to 20 carbon atoms, unsubstituted heterocyclyl having 3 to 20 ring atoms, unsubstituted aralkyl having 7 to 30 carbon atoms, unsubstituted alkoxy having 1 to 20 carbon atoms, unsubstituted aryloxy having 6 to 30 carbon atoms, unsubstituted alkenyl having 2 to 20 carbon atoms, unsubstituted alkynyl having 2 to 20 carbon atoms, unsubstituted aryl having 6 to 30 carbon atoms, unsubstituted heteroaryl having 3-30 carbon atoms, unsubstituted alkylsilyl having 3-20 carbon atoms, unsubstituted arylsilyl having 6-20 carbon atoms, unsubstituted alkylgermanyl having 3-20 carbon atoms, unsubstituted arylgermanyl having 6-20 carbon atoms, unsubstituted amino having 0-20 carbon atoms, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphino and combinations thereof.

[0068] It should be understood that when describing a molecular fragment as a substituent or otherwise attached to another moiety, its name can be written according to whether it is a fragment (e.g., phenyl, phenylene, naphthyl, dibenzofuranyl) or according to whether it is a whole molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, these different ways of specifying a substituent or attaching a fragment are considered equivalent.

[0069] In the compounds mentioned in this disclosure, hydrogen atoms may be partially or completely replaced by deuterium. Other atoms such as carbon and nitrogen may also be replaced by their other stable isotopes. The replacement of other stable isotopes in the compounds may be preferred because it enhances the efficiency and stability of the device.

[0070] In the compounds mentioned in the present disclosure, multiple substitution refers to the range including disubstitution up to the maximum number of available substitutions. When a substituent in the compounds mentioned in the present disclosure represents multiple substitutions (including disubstitution, trisubstitution, tetrasubstitution, etc.), it means that the substituent can exist in multiple available substitution positions on its connection structure, and the substituents existing in multiple available substitution positions can be of the same structure or different structures.

[0071] In the compounds mentioned in the present disclosure, unless clearly defined, for example, adjacent substituents can be optionally connected to form a ring, otherwise adjacent substituents in the compound cannot be connected to form a ring. In the compounds mentioned in the present disclosure, adjacent substituents can be optionally connected to form a ring, including both the situation where adjacent substituents can be connected to form a ring and the situation where adjacent substituents are not connected to form a ring. When adjacent substituents can be optionally connected to form a ring, the formed ring can be a monocyclic or polycyclic ring (including spirocyclic, bridged ring, condensed ring, etc.), as well as an alicyclic, heteroalicyclic, aromatic or heteroaromatic ring. In this statement, adjacent substituents can refer to substituents bonded to the same atom, substituents bonded to carbon atoms directly bonded to each other, or substituents bonded to carbon atoms further away. Preferably, adjacent substituents refer to substituents bonded to the same carbon atom and substituents bonded to carbon atoms directly bonded to each other.

[0072] The expression that adjacent substituents can be optionally linked to form a ring is also intended to be taken to mean that two substituents bonded to the same carbon atom are linked to each other by a chemical bond to form a ring, which can be exemplified by the following formula:

[0073]

[0074] The expression that adjacent substituents can be optionally linked to form a ring is also intended to be taken to mean that two substituents bonded to carbon atoms directly bonded to each other are linked to each other by a chemical bond to form a ring, which can be exemplified by the following formula:

[0075]

[0076] The expression that adjacent substituents can be optionally linked to form a ring is also intended to be taken to mean that two substituents bonded to a further distant carbon atom are linked to each other by a chemical bond to form a ring, which can be exemplified by the following formula:

[0077]

[0078] Furthermore, the statement that adjacent substituents can optionally be linked to form a ring is also intended to be taken to mean that, in the case where one of the two adjacent substituents represents hydrogen, the second substituent is bonded at the position to which the hydrogen atom is bonded, thereby forming a ring. This is exemplified by the following formula:

[0079]

[0080] According to one embodiment of the present invention, a metal complex is disclosed, which comprises a metal M and a ligand L coordinated with the metal M. a , where L a Having a structure represented by Formula 1:

[0081]

[0082] In formula 1,

[0083] The metal M is selected from metals with a relative atomic mass greater than 40;

[0084] Cy is selected, at each occurrence, identically or differently, from a substituted or unsubstituted aromatic ring having 6 to 24 ring atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 24 ring atoms, or a combination thereof;

[0085] X is selected from the group consisting of O, S, Se, NR', CR'R', SiR'R' and GeR'R'; when two R' exist at the same time, the two R' are the same or different;

[0086] X1-X8 are selected from C, CR in the same or different manner at each occurrence x or N; at least one of X1-X4 is C and is connected to the Cy;

[0087] X1, X2, X3 or X4 is connected to the metal M through a metal-carbon bond or a metal-nitrogen bond;

[0088] At least one of X1-X8 is CR x , and the R x is cyano or fluorine;

[0089] At least one of X1-X8 is CR x , and R x Ar has a structure represented by Formula 2:

[0090]

[0091] a is selected from 0, 1, 2, 3, 4 or 5;

[0092] R a1 and R a2 Each occurrence, identically or differently, indicates mono-, poly- or non-substitution;

[0093] Ring Ar1 and ring Ar2 are identically or differently selected from aromatic rings having 6-30 ring atoms, heteroaromatic rings having 5-30 ring atoms, or combinations thereof at each occurrence; and the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8;

[0094] R', R x (refers to the existence of X1-X8 and excluding the above specific R X The remaining R X ), R a1 and R a2 The group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0095] “*” indicates the connection position of formula 2;

[0096] The adjacent substituents R', R x , R a1 , R a2 Can optionally be linked to form a ring.

[0097] As used herein, “adjacent substituents R′, R x , R a1 , R a2 "can be optionally connected to form a ring" is intended to mean that adjacent groups of substituents, for example, between two substituents R', between two substituents R x Between the two substituents R a1 Between the two substituents R a2 Between the two substituents R' and R x Between the two substituents R a1 and R a2 Any one or more of these substituent groups may be connected to form a ring. Obviously, none of these substituent groups may be connected to form a ring.

[0098] In this article, "ring atoms" in aromatic rings and heteroaromatic rings refer to atoms that are bonded to form a cyclic structure with aromaticity (for example: a monocyclic (hetero) aromatic ring, a condensed (hetero) aromatic ring) that constitutes the ring itself. Carbon atoms and heteroatoms (including but not including O, S, N, Se or Si, etc.) in the ring are all counted in the number of ring atoms. When the ring is substituted by a substituent, the atoms contained in the substituent are not included in the number of ring atoms. For example, the number of ring atoms of phenyl, pyridyl, and triazine is 6; the number of ring atoms of dithiophene and difuran is 8; the number of ring atoms of benzothienyl and benzofuranyl is 9; the number of ring atoms of naphthyl, quinolyl, isoquinolyl, quinazolinyl, and quinoxalinyl is 10; the number of ring atoms of dibenzothiophene, dibenzofuran, fluorene, azadibenzothiophene, azadibenzofuran and azafluorene is 13; the various examples described here are only for illustration, and other cases are similar. When a in Formula 2 is 0, it means that Ar has In the structure represented by, "the total number of ring atoms of ring Ar1 and ring Ar2 is greater than or equal to 8" means that ring Ar1 is an aromatic ring or heteroaromatic ring having a total number of ring atoms greater than or equal to 8; when a in formula 2 is 1, it means that Ar has For example, in this case, both ring Ar1 and ring Ar2 are phenyl, R a1 and R a2 When both are hydrogen, the total number of ring atoms of ring Ar1 and ring Ar2 is 12; for example, when both ring Ar1 and ring Ar2 are phenyl, R a1 All are hydrogen, R a2 When it is monosubstituted and is phenyl, the total number of ring atoms in the ring Ar1 and the ring Ar2 is equal to 12. The same applies to other cases.

[0099] According to one embodiment of the present invention, wherein Cy is selected from any structure in the group consisting of:

[0100]

[0101] in,

[0102] Each occurrence of R is the same or different, indicating mono-substitution, poly-substitution, or no substitution; when multiple R are present in any structure, the R are the same or different;

[0103] R is selected, at each occurrence, identically or differently, from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0104] Two adjacent substituents R can optionally be linked to form a ring;

[0105] Among them, '#' indicates the position connected to the metal M, Indicates a location connected to X1, X2, X3, or X4.

[0106] Herein, "two adjacent substituents R can be optionally connected to form a ring" is intended to mean that any one or more of the substituent groups formed between any two adjacent substituents R can be connected to form a ring. Obviously, these substituents may not be connected to form a ring.

[0107] According to one embodiment of the present invention, L a Each occurrence is identically or differently selected from the group consisting of:

[0108]

[0109]

[0110]

[0111]

[0112] in,

[0113] X is selected from the group consisting of O, S, Se, NR', CR'R', SiR'R' and GeR"R"; when two R' exist at the same time, the two R' are the same or different;

[0114] R and R x Each occurrence is identical or different and indicates mono-, poly-, or unsubstituted;

[0115] R x At least one of them is fluorine or cyano;

[0116] R x At least one of them is Ar, and the Ar has a structure represented by Formula 2:

[0117]

[0118] a is selected from 0, 1, 2, 3, 4 or 5;

[0119] Ring Ar1 and ring Ar2 are identically or differently selected from aromatic rings having 6-30 ring atoms, heteroaromatic rings having 5-30 ring atoms, or combinations thereof at each occurrence; and the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8;

[0120] R a1 and R a2 Each occurrence is identical or different and indicates mono-, poly-, or unsubstituted;

[0121] R, R', R x , R a1 and R a2The group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0122] Adjacent substituents R, R', R x , R a1 and R a2 can optionally be linked to form a ring;

[0123] “*” indicates the connection position of Formula 2.

[0124] As used herein, “adjacent substituents R, R′, R x , R a1 and R a2 "can be optionally connected to form a ring" is intended to mean that adjacent groups of substituents, for example, between two substituents R, between two substituents R', between two substituents R x Between the two substituents R a1 Between the two substituents R a2 Between the two substituents R' and R x Between the two substituents R a1 and R a2 Any one or more of these substituent groups may be connected to form a ring. Obviously, none of these substituent groups may be connected to form a ring.

[0125] According to one embodiment of the present invention, the metal complex has M(L a ) m (L b ) n (L c ) q The general formula of

[0126] in,

[0127] M is selected from the group consisting of Cu, Ag, Au, Ru, Rh, Pd, Os, Ir and Pt at each occurrence, the same or different; preferably, M is selected from Pt or Ir at each occurrence, the same or different;

[0128] L a , L b and L c are the first, second and third ligands coordinated to the metal M, and L c and the L a or L b are the same or different; where L a , L b and L c can optionally be linked to form a multidentate ligand; for example, L a , L b and L c Any two of can be connected to form a tetradentate ligand; for example, L a , L b and L c can be connected to each other to form a hexadentate ligand; or for example, L a , L b , L c None of them are connected so as not to form a multidentate ligand;

[0129] m is selected from 1, 2 or 3, n is selected from 0, 1 or 2, q is selected from 0, 1 or 2, m+n+q is equal to the oxidation state of metal M; when m is greater than or equal to 2, multiple L a The same or different; when n is equal to 2, the two L b The same or different; when q is equal to 2, the two L c Same or different;

[0130] L b and L c Each occurrence is identically or differently selected from any one of the following groups:

[0131]

[0132] in,

[0133] R a , R b Each occurrence is identical or different and indicates mono-, poly-, or unsubstituted;

[0134] X b Each occurrence is identically or differently selected from the group consisting of: O, S, Se, NR N1 , CRC1 R C2 ;

[0135] R a , R b , R c , R N1 , R C1 and R C2 The group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0136] Adjacent substituent R a , R b , R c , R N1 , R C1 and R C2 Can optionally be linked to form a ring.

[0137] In this context, “the adjacent substituent R a , R b , R c , R N1 , R C1 and R C2 "can optionally be linked to form a ring" is intended to mean that adjacent groups of substituents, for example, two substituents R a Between the two substituents R b Between the two substituents R c Between, the substituent R a and R b Between, the substituent R a and R c Between, the substituent R band R c Between, the substituent R a and R N1 Between, the substituent R b and R N1 Between, the substituent R a and R C1 Between, the substituent R a and R C2 Between, the substituent R b and R C1 Between, the substituent R b and R C2 Between, and R C1 and R C2 Any one or more of these substituent groups may be connected to form a ring. Obviously, none of these substituent groups may be connected to form a ring.

[0138] According to one embodiment of the present invention, the metal M is selected from the group consisting of Cu, Ag, Au, Ru, Rh, Pd, Os, Ir and Pt each time it appears, the same or different.

[0139] According to one embodiment of the present invention, the metal M is selected from Pt or Ir, the same or different each time it occurs.

[0140] According to one embodiment of the present invention, the metal complex Ir(L a ) m (L b ) 3-m Having a structure represented by Formula 3:

[0141]

[0142] in,

[0143] m is selected from 1, 2 or 3; when m is selected from 1, two L b The same or different; when m is selected from 2 or 3, multiple L a Same or different;

[0144] X is selected from the group consisting of O, S, Se, NR', CR'R', SiR'R' and GeR'R'; when two R' exist at the same time, the two R' are the same or different;

[0145] Each occurrence of Y1-Y4 is identical or different and is selected from CR y or N;

[0146] X3-X8 are selected from CR in the same or different way each time they appear x or N;

[0147] At least one of X3-X8 is CR x, and the R x is cyano or fluorine;

[0148] At least one of X3-X8 is CR x , and R x Ar has a structure represented by Formula 2:

[0149]

[0150] a is selected from 0, 1, 2, 3, 4 or 5;

[0151] R a1 and R a2 The same or different at each occurrence indicates mono-, poly- or no-substitution;

[0152] Ring Ar1 and ring Ar2 are identically or differently selected from aromatic rings having 6-30 ring atoms, heteroaromatic rings having 5-30 ring atoms, or combinations thereof at each occurrence; and the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8;

[0153] R', R x , R y , R1-R8, R a1 and R a2 The group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0154] “*” indicates the connection position of formula 2;

[0155] The adjacent substituents R', R x , R y , Ra1 , R a2 can optionally be linked to form a ring;

[0156] Adjacent substituents R1 to R8 can optionally be linked to form a ring.

[0157] As used herein, “adjacent substituents R′, R x , R y , R a1 , R a2 "can be optionally connected to form a ring" is intended to mean that adjacent groups of substituents, for example, between two substituents R', between two substituents R x Between the two substituents R y Between the two substituents R a1 Between the two substituents R a2 Between the two substituents R a1 and R a2 Between the two substituents R' and R x Between, any one or more of these substituent groups can be connected to form a ring. Obviously, these substituents can also not be connected to form a ring. "Adjacent substituents R1-R8 can optionally be connected to form a ring" is intended to mean that adjacent substituent groups, for example, between adjacent substituents R1 and R2, between adjacent substituents R3 and R2, between adjacent substituents R3 and R4, between adjacent substituents R5 and R4, between adjacent substituents R5 and R6, between adjacent substituents R7 and R6, between adjacent substituents R7 and R8, any one or more of these substituent groups can be connected to form a ring. Obviously, these substituents can also not be connected to form a ring.

[0158] According to one embodiment of the present invention, the metal complex Ir(L a ) m (L b ) 3-m Having a structure represented by Formula 3A:

[0159]

[0160] in,

[0161] m is selected from 1, 2 or 3; when m is selected from 1, two L b The same or different; when m is selected from 2 or 3, multiple L a Same or different;

[0162] X is selected from the group consisting of O, S, Se, NR', CR'R', SiR'R' and GeR'R'; when two R' exist at the same time, the two R' are the same or different;

[0163] Rx and R y The same or different at each occurrence indicates mono-, poly- or no-substitution;

[0164] R x At least one of them is cyano or fluorine; Ar has a structure represented by formula 2:

[0165]

[0166] a is selected from 0, 1, 2, 3, 4 or 5;

[0167] Ring Ar1 and ring Ar2 are identically or differently selected from aromatic rings having 6-30 ring atoms, heteroaromatic rings having 5-30 ring atoms, or combinations thereof at each occurrence; and the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8;

[0168] R a1 and R a2 The same or different at each occurrence indicates mono-, poly- or no-substitution;

[0169] R', R x , R y , R1-R8, R a1 and R a2 The group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

[0170] “*” indicates the connection position of formula 2;

[0171] The adjacent substituents R', R x , R y , , Ra1 , R a2 can optionally be linked to form a ring;

[0172] Adjacent substituents R1 to R8 can optionally be linked to form a ring.

[0173] According to one embodiment of the present invention, X is selected from O or S.

[0174] According to one embodiment of the present invention, wherein X is O.

[0175] According to one embodiment of the present invention, each occurrence of X1-X8 is selected from C or CR x .

[0176] According to an embodiment of the present invention, at least one of X1-X8 is N, for example, one of X1-X8 is N or two of X1-X8 are N.

[0177] According to one embodiment of the present invention, in Formula 3, X3-X8 are selected from CR x .

[0178] According to one embodiment of the present invention, in Formula 3, at least one of X3-X8 is N, for example, one of X3-X8 is N or two of them are N.

[0179] According to one embodiment of the present invention, each occurrence of Y1-Y4 is identically or differently selected from CR y .

[0180] According to an embodiment of the present invention, at least one of Y1-Y4 is N, for example, one of Y1-Y4 is N or two of Y1-Y4 are N.

[0181] According to one embodiment of the present invention, a is selected from 0, 1, 2 or 3.

[0182] According to one embodiment of the present invention, wherein a is selected from 1.

[0183] According to one embodiment of the present invention, at least one of X5-X8 is selected from CR x , and the R x It is cyano or fluorine.

[0184] According to one embodiment of the present invention, at least one of X7-X8 is selected from CR x , and the R x It is cyano or fluorine.

[0185] According to one embodiment of the present invention, X7 is CR x , and the R x It is cyano or fluorine.

[0186] According to one embodiment of the present invention, X8 is CR x , and the R x It is cyano or fluorine.

[0187] According to one embodiment of the present invention, at least one of X5-X8 is selected from CR x , and the R x It's Ar.

[0188] According to one embodiment of the present invention, at least one of X7-X8 is selected from CR x , and the R x It's Ar.

[0189] According to one embodiment of the present invention, X8 is selected from CR x , and the R x It's Ar.

[0190] According to one embodiment of the present invention, X7 is selected from CR x , and the R x It's Ar.

[0191] According to one embodiment of the present invention, R a1 and R a2 Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, cyano, isocyano, hydroxyl, mercapto, and combinations thereof.

[0192] According to one embodiment of the present invention, R a1 and R a2 Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, and combinations thereof.

[0193] According to one embodiment of the present invention, R a1 and R a2Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, fluorine, substituted or unsubstituted alkyl having 1 to 6 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 6 ring carbon atoms, substituted or unsubstituted aryl having 6 to 18 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 18 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 15 carbon atoms, and combinations thereof.

[0194] According to one embodiment of the present invention, R a1 and R a2 Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, fluorine, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopentyl, cyclohexyl, deuterated methyl, deuterated ethyl, deuterated propyl, deuterated isopropyl, deuterated n-butyl, deuterated isobutyl, deuterated tert-butyl, deuterated cyclopentyl, deuterated cyclohexyl, phenyl, pyridyl, trimethylsilyl, and combinations thereof.

[0195] According to one embodiment of the present invention, in Ar, ring Ar1 and ring Ar2 are identically or differently selected from aromatic rings having 6-18 ring atoms, heteroaromatic rings having 5-18 ring atoms, or combinations thereof each time they appear; and the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8 and less than or equal to 30.

[0196] According to one embodiment of the present invention, in Ar, the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8 and less than or equal to 24.

[0197] According to one embodiment of the present invention, in Ar, the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8 and less than or equal to 18.

[0198] According to one embodiment of the present invention, in Ar, the rings Ar1 and Ar2 are selected, each time they occur, identically or differently, from an aromatic ring having 6 ring atoms, or a heteroaromatic ring having 5 or 6 ring atoms, or a combination thereof.

[0199] According to one embodiment of the present invention, in Ar, the rings Ar1 and Ar2 are selected, identically or differently, each time they occur, from an aromatic ring or a heteroaromatic ring having 6 ring atoms.

[0200] According to one embodiment of the present invention, in Ar, the rings Ar1 and Ar2 are selected, identically or differently, each time they occur, from aromatic rings having 6 ring atoms.

[0201] According to one embodiment of the present invention, in Ar, ring Ar1 and ring Ar2 are selected from the group consisting of: benzene ring, pyridine ring, pyrimidine ring, triazine ring, naphthalene ring, phenanthrene ring, anthracene ring, fluorene ring, silylene ring, quinoline ring, isoquinoline ring, dithiophene ring, difuran ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, triphenylene ring, carbazole ring, azacarbazole ring, azafluorene ring, azasilylene ring, azadibenzofuran ring, azadibenzothiophene ring, and combinations thereof each time they appear; and the total number of ring atoms of ring Ar1 and ring Ar2 is greater than or equal to 8 and less than or equal to 30.

[0202] According to one embodiment of the present invention, wherein Ar appears each time and is identically or differently selected from substituted or unsubstituted biphenyl, substituted or unsubstituted dithienyl, substituted or unsubstituted difuranyl, substituted or unsubstituted indolyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted anthracenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted silylfluorenyl, substituted or unsubstituted germaniumfluorenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted azadibenzothienyl, substituted or unsubstituted azadibenzofuranyl, substituted or unsubstituted azacarbazolyl, substituted or unsubstituted azabiphenyl, substituted or unsubstituted triphenylene, and combinations thereof.

[0203] According to one embodiment of the present invention, wherein Ar is selected from the group consisting of the following identically or differently each time it occurs:

[0204]

[0205] and combinations thereof;

[0206] Optionally, the hydrogen in the above groups can be partially or completely replaced by deuterium; wherein "*" indicates the connection position of the Ar.

[0207] According to one embodiment of the present invention, wherein the R x At least one of them is selected from cyano or fluorine, R x At least one of them is selected from Ar, and the rest R x Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, cyano, and combinations thereof.

[0208] According to one embodiment of the present invention, R xAt least one of them is selected from cyano or fluorine, R x At least one of them is selected from Ar, and the rest R x Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, fluorine, substituted or unsubstituted alkyl having 1 to 6 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 6 ring carbon atoms, substituted or unsubstituted aryl having 6 to 12 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 12 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 6 carbon atoms, cyano, and combinations thereof.

[0209] According to one embodiment of the present invention, R x At least one of them is selected from cyano or fluorine, R x At least one of them is selected from Ar, and the rest R x Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted alkyl having 1 to 6 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 6 ring carbon atoms, and combinations thereof.

[0210] According to one embodiment of the present invention, R y Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, and combinations thereof.

[0211] According to one embodiment of the present invention, R y Selected from the group consisting of hydrogen, deuterium, fluorine, substituted or unsubstituted alkyl having 1-6 carbon atoms, substituted or unsubstituted cycloalkyl having 3-6 ring carbon atoms, substituted or unsubstituted aryl having 6-12 carbon atoms, substituted or unsubstituted heteroaryl having 3-11 carbon atoms, substituted or unsubstituted alkylsilyl having 3-6 carbon atoms, cyano, and combinations thereof.

[0212] According to one embodiment of the present invention, R y Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopentyl, cyclohexyl, deuterated methyl, deuterated ethyl, deuterated propyl, deuterated isopropyl, deuterated n-butyl, deuterated isobutyl, deuterated tert-butyl, deuterated cyclopentyl, deuterated cyclohexyl, phenyl, pyridyl, trimethylsilyl, and combinations thereof.

[0213] According to one embodiment of the present invention, R y Selected from hydrogen or deuterium.

[0214] According to one embodiment of the present invention, in Formula 3, at least one R y Selected from the group consisting of deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, and combinations thereof.

[0215] According to one embodiment of the present invention, wherein, in Formula 3, at least one or at least two or at least three or all of R2, R3, R6, and R7 are selected from the group consisting of: deuterium, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, and combinations thereof.

[0216] According to one embodiment of the present invention, in Formula 3, at least one or at least two or at least three or all of R2, R3, R6, and R7 are selected from the group consisting of: deuterium, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, and combinations thereof.

[0217] According to one embodiment of the present invention, in Formula 3, at least one or at least two or at least three or all of R2, R3, R6, and R7 are selected from the group consisting of: deuterium, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopentyl, cyclohexyl, and combinations thereof; optionally, the hydrogen in the above groups is partially or completely deuterated.

[0218] According to one embodiment of the present invention, R' is selected from a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms.

[0219] According to one embodiment of the present invention, R' is methyl or deuterated methyl.

[0220] According to one embodiment of the present invention, L a Each time it appears, choose the same or different one from L a1 To L a955 The group consisting of L a1 To L a955 The specific structure is described in claim 16.

[0221] According to one embodiment of the present invention, L b Each time it appears, choose the same or different one from L b1 To L b128 The group consisting of L b1 To L b128 The specific structure is described in claim 17.

[0222] According to one embodiment of the present invention, L c Each time it appears, choose the same or different one from L c1 To L c360 The group consisting of L c1 To L c360 The specific structure is described in claim 18.

[0223] According to one embodiment of the present invention, the metal complex has Ir(L a )2(L b ) structure, L a Each time it appears, choose the same or different one from L a1 To L a955 Any one or two of the group consisting of L b Choose from L b1 To L b128 Any of the group consisting of a1 To L a955 The specific structure is described in claim 16, L b1 To L b128 The specific structure is described in claim 17.

[0224] According to one embodiment of the present invention, the metal complex has Ir(L a )(L b )2 structure, L a Each time it appears, choose the same or different one from L a1 To L a955 Any of the groups consisting of L b Choose from L b1 To L b128 Any one or any two of the group consisting of a1 To L a955 The specific structure is described in claim 16, L b1 To L b128 The specific structure is described in claim 17.

[0225] According to one embodiment of the present invention, the metal complex has Ir(L a )3 structure, L a Each time it appears, choose the same or different one from L a1 To La955 Any one, any two, or any three of the group consisting of a1 To L a955 The specific structure is described in claim 16.

[0226] According to one embodiment of the present invention, the metal complex has Ir(L a )2(L c ) structure, L a Each time it appears, choose the same or different one from L a1 To L a955 Any one or two of the group consisting of L c Choose from L c1 To L c360 Any of the group consisting of a1 To L a955 The specific structure is described in claim 16, L c1 To L c360 The specific structure is described in claim 18.

[0227] According to one embodiment of the present invention, the metal complex has Ir(L a )(L c )2 structure, L a Each time it appears, choose the same or different one from L a1 To L a955 Any of the groups consisting of L c Choose from L c1 To L c360 Any one or any two of the group consisting of a1 To L a955 The specific structure is described in claim 16, L c1 To L c360 The specific structure is described in claim 18.

[0228] According to one embodiment of the present invention, the metal complex has Ir(L a )(L b )(L c ) structure, where L a Each time it appears, choose the same or different one from L a1 To L a955 Any of the groups consisting of L b Choose from L b1 To L b128 Any of the groups consisting of L c Choose from L c1 To L c360 Any one of the group consisting of; wherein L a1 To L a955The specific structure is described in claim 16, L b1 To L b128 The specific structure is described in claim 17, L c1 To L c360 The specific structure is described in claim 18.

[0229] According to one embodiment of the present invention, the metal complex is selected from the group consisting of metal complex 1 to metal complex 1216, wherein the specific structures of metal complex 1 to metal complex 1216 are described in claim 19.

[0230] According to one embodiment of the present invention, an electroluminescent device is disclosed, comprising:

[0231] anode,

[0232] cathode,

[0233] and an organic layer disposed between the anode and the cathode, wherein the organic layer comprises the metal complex described in any one of the above embodiments.

[0234] According to one embodiment of the present invention, the organic layer containing the metal complex in the electroluminescent device is a light-emitting layer.

[0235] According to an embodiment of the present invention, the electroluminescent device emits green light.

[0236] According to an embodiment of the present invention, the electroluminescent device emits white light.

[0237] According to an embodiment of the present invention, the light-emitting layer of the electroluminescent device comprises a first host compound.

[0238] According to one embodiment of the present invention, the light-emitting layer of the electroluminescent device comprises a first host compound and a second host compound.

[0239] According to one embodiment of the present invention, the first host compound and / or the second host compound in the electroluminescent device contain at least one chemical group selected from the group consisting of: benzene, pyridine, pyrimidine, triazine, carbazole, azacarbazole, indolecarbazole, dibenzothiophene, azadibenzothiophene, dibenzofuran, azadibenzofuran, dibenzoselenophene, triphenylene, azatriphenylene, fluorene, silylfluorene, naphthalene, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene, azaphenanthrene, and combinations thereof.

[0240] According to one embodiment of the present invention, the first host compound has a structure represented by Formula 4:

[0241]

[0242] in,

[0243] Each occurrence of E1-E6 is selected from C, CR e or N, and at least two of E1-E6 are N, and at least one of E1-E6 is C, and they are connected to formula A;

[0244]

[0245] in,

[0246] Q is the same or different each time it appears and is selected from the group consisting of O, S, Se, N, NR", CR"R", SiR"R", GeR"R" and R"C=CR"; when two R" are present at the same time, the two R" can be the same or different;

[0247] p is 0 or 1; r is 0 or 1;

[0248] When Q is selected from N, p is 0 and r is 1;

[0249] When Q is selected from the group consisting of O, S, Se, NR", CR"R", SiR"R", GeR"R" and R"C=CR", p is 1 and r is 0;

[0250] L is identically or differently selected at each occurrence from a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 20 carbon atoms, or a combination thereof;

[0251] Each occurrence of Q1-Q8 is selected from C, CR q or N;

[0252] R e , R' and R qEach occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted Alkynyl groups having 2 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermanyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanyl groups having 6 to 20 carbon atoms, substituted or unsubstituted amine groups having 0 to 20 carbon atoms, acyl groups, carbonyl groups, carboxylic acid groups, ester groups, cyano groups, isocyano groups, hydroxyl groups, mercapto groups, sulfinyl groups, sulfonyl groups, phosphino groups, and combinations thereof;

[0253] “*” represents the connection position between Formula A and Formula 4;

[0254] Adjacent substituent R e , R”, R q Can optionally be linked to form a ring.

[0255] In this context, “the adjacent substituent R e , R”, R q "can optionally be linked to form a ring" is intended to mean that adjacent groups of substituents, for example, two substituents R e Between two substituents R", between two substituents R q Between the two substituents R" and R q Any one or more of these substituent groups may be connected to form a ring. Obviously, none of these substituent groups may be connected to form a ring.

[0256] According to one embodiment of the present invention, each occurrence of Q is identically or differently selected from O, S, N or NR".

[0257] According to one embodiment of the present invention, each occurrence of E1-E6 is identically or differently selected from C, CR e or N, and three of E1-E6 are N, E 1- At least one of E6 is CR e , and the R eEach occurrence is identically or differently selected from the group consisting of substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, and combinations thereof.

[0258] According to one embodiment of the present invention, each occurrence of E1-E6 is identically or differently selected from C, CR e or N, and three of E1-E6 are N, E 1- At least one of E6 is CR e , and the R e Each occurrence is identically or differently selected from substituted or unsubstituted phenyl, substituted or substituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted carbazolyl, or a combination thereof.

[0259] According to one embodiment of the present invention, R e Each occurrence is identically or differently selected from the group consisting of substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, and combinations thereof.

[0260] According to one embodiment of the present invention, R e Each occurrence is identically or differently selected from substituted or unsubstituted phenyl, substituted or substituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted carbazolyl, or a combination thereof.

[0261] According to one embodiment of the present invention, at least one or at least two of Q1-Q8 are selected from CR q , and the R q is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 carbon atoms, or a combination thereof.

[0262] According to one embodiment of the present invention, at least one or at least two of Q1-Q8 are selected from CR q , and the R q is selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted pyridyl, or a combination thereof.

[0263] According to one embodiment of the present invention, L is selected from a single bond, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 20 carbon atoms, or a combination thereof, the same or different each time it occurs.

[0264] According to one embodiment of the present invention, wherein L is selected from a single bond, a substituted or unsubstituted phenylene, a substituted or unsubstituted biphenylene, a substituted or unsubstituted carbazolyl, a substituted or unsubstituted dibenzofuranyl, a substituted or unsubstituted dibenzothiophenylene, a substituted or unsubstituted fluorenylene the same or differently each time it appears.

[0265] According to one embodiment of the present invention, L is selected from a single bond, a substituted or unsubstituted phenylene group, and a substituted or unsubstituted biphenylene group, the same or different when it appears each time.

[0266] According to one embodiment of the present invention, the first host compound is selected from the group consisting of H-1 to H-243, wherein the specific structures of H-1 to H-243 are described in claim 26.

[0267] According to one embodiment of the present invention, the second host compound in the electroluminescent device has a structure represented by Formula 5:

[0268]

[0269] in,

[0270] L x is selected, at each occurrence, identically or differently, from a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 20 carbon atoms, or a combination thereof;

[0271] Each occurrence of V is selected from C, CR v or N, and at least one of V is C, and L x connect;

[0272] Each occurrence of U is selected from C, CR, or u or N, and at least one of U is C, and L x connect;

[0273] R v and R uEach occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted Alkynyl groups having 2 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermanyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanyl groups having 6 to 20 carbon atoms, substituted or unsubstituted amine groups having 0 to 20 carbon atoms, acyl groups, carbonyl groups, carboxylic acid groups, ester groups, cyano groups, isocyano groups, hydroxyl groups, mercapto groups, sulfinyl groups, sulfonyl groups, phosphino groups, and combinations thereof;

[0274] Ar6 is selected, at each occurrence, identically or differently, from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, or a combination thereof;

[0275] Adjacent substituent R v and R u Can optionally be linked to form a ring.

[0276] In this embodiment, "the adjacent substituent R v and R u "can optionally be linked to form a ring" is intended to mean that adjacent groups of substituents, for example, two substituents R v Between the two substituents R u Between the two substituents R v and R u Any one or more of these substituent groups may be connected to form a ring. Obviously, none of these substituent groups may be connected to form a ring.

[0277] According to one embodiment of the present invention, the second host compound in the electroluminescent device has a compound having a formula of 5-a to

[0278] The structure represented by one of formula 5-j:

[0279]

[0280]

[0281] in,

[0282] L x is selected, at each occurrence, identically or differently, from a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 20 carbon atoms, or a combination thereof;

[0283] Each time V appears, it is selected from CR in the same or different way. v or N;

[0284] Each time U appears, it is selected from CR in the same or different way. u or N;

[0285] R v and R u Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted Alkynyl groups having 2 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermanyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanyl groups having 6 to 20 carbon atoms, substituted or unsubstituted amine groups having 0 to 20 carbon atoms, acyl groups, carbonyl groups, carboxylic acid groups, ester groups, cyano groups, isocyano groups, hydroxyl groups, mercapto groups, sulfinyl groups, sulfonyl groups, phosphino groups, and combinations thereof;

[0286] Ar6 is selected, at each occurrence, identically or differently, from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, or a combination thereof;

[0287] Adjacent substituent R v and R u Can optionally be linked to form a ring.

[0288] According to one embodiment of the present invention, the second main compound is selected from the group consisting of compounds X-1 to X-128, wherein the specific structures of compounds X-1 to X-128 are described in claim 28.

[0289] According to an embodiment of the present invention, in the electroluminescent device, the metal complex is doped in the first host compound and the second host compound, and the weight of the metal complex accounts for 1% to 30% of the total weight of the light-emitting layer.

[0290] According to one embodiment of the present invention, in the electroluminescent device, the metal complex is doped into the first host compound and the second host compound, and the weight of the metal complex accounts for 3%-13% of the total weight of the light-emitting layer.

[0291] According to another embodiment of the present invention, a compound combination is disclosed. The compound combination comprises the metal complex described in any of the aforementioned embodiments.

[0292] Combination with other materials

[0293] The materials for specific layers in the organic light-emitting device described in the present invention can be used in combination with various other materials present in the device. The combination of these materials is described in detail in paragraphs 0132-0161 of U.S. Patent Application US2016 / 0359122A1, the entire contents of which are incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can easily consult the literature to identify other materials that can be used in combination.

[0294] The materials described herein as specific layers that can be used in organic light-emitting devices can be used in combination with a variety of other materials present in the device. For example, the light-emitting dopants disclosed herein can be used in combination with a variety of hosts, transport layers, barrier layers, injection layers, electrodes, and other layers that may be present. The combination of these materials is described in detail in paragraphs 0080-0101 of U.S. Patent Application US2015 / 0349273A1, the entire contents of which are incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can easily consult the literature to identify other materials that can be used in combination.

[0295] In the embodiment of material synthesis, unless otherwise stated, all reactions are carried out under nitrogen protection. All reaction solvents are anhydrous and used as they are from commercial sources. The synthetic product uses one or more conventional equipment in the art (including but not limited to Bruker's nuclear magnetic resonance instrument, Shimadzu's liquid chromatograph, liquid chromatography-mass spectrometer, gas chromatography-mass spectrometer, differential scanning calorimeter, Shanghai Lingguang Technology's fluorescence spectrophotometer, Wuhan Cost's electrochemical workstation, Anhui Bei Yi Ke's sublimator, etc.), and the structure is confirmed and the characteristics are tested by methods well known to those skilled in the art. In the embodiment of the device, the characteristics of the device are also tested by methods well known to those skilled in the art using conventional equipment in the art (including but not limited to Angstrom Engineering's evaporation machine, Suzhou Fushida's optical test system, life test system, Beijing Liangtuo's ellipsometer, etc.). Since those skilled in the art are aware of the use of the above-mentioned equipment, test methods and other related contents, it is possible to obtain the inherent data of the sample with certainty and without being affected, so the above-mentioned related contents are no longer expanded in this patent.

[0296] Material synthesis example:

[0297] The preparation method of the compound of the present invention is not limited, and the following compounds are typically but not limitedly exemplified, and their synthetic routes and preparation methods are as follows:

[0298] Synthesis Example 1: Synthesis of Metal Complex 151

[0299] Step 1:

[0300]

[0301] 5-Methyl-2-phenylpyridine (10.0 g, 59.2 mmol), iridium trichloride trihydrate (5.0 g, 14.2 mmol), 300 mL of 2-ethoxyethanol, and 100 mL of water were added to a dry 500 mL round-bottom flask in sequence, and the nitrogen atmosphere was replaced three times and protected by nitrogen atmosphere, and heated and stirred at 130°C for 24 h. After cooling, the mixture was filtered, rinsed three times with methanol and n-hexane respectively, and dried to obtain 7.5 g of yellow solid intermediate 1 (97% yield).

[0302] Step 2:

[0303]

[0304] In a dry 500 mL round-bottom flask, add intermediate 1 (7.5 g, 6.8 mmol), anhydrous dichloromethane 250 mL, methanol 10 mL, silver trifluoromethanesulfonate (3.8 g, 14.8 mmol), replace with nitrogen three times and protect with nitrogen, stir at room temperature overnight. Filter through diatomaceous earth, rinse with dichloromethane twice, collect the organic phase below and concentrate under reduced pressure to obtain 9.2 g of intermediate 2 (93% yield).

[0305] Step 3:

[0306]

[0307] In a dry 250mL round-bottom flask, add intermediate 2 (2.2g, 3.0mmol), intermediate 3 (1.7g, 3.9mmol), 2-ethoxyethanol and N,N-dimethylformamide 50mL each, replace with nitrogen three times and protect with nitrogen, heat at 100℃ for 96h. After the reaction is cooled, filter with diatomaceous earth. Wash with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify by column chromatography to obtain a yellow solid product metal complex 151 (1.3g, 45.6% yield), which is a yellow solid. The product is determined to be the target product with a molecular weight of 950.3.

[0308] Synthesis Example 2: Synthesis of Metal Complex 186

[0309]

[0310] In a dry 250mL round-bottom flask, add intermediate 2 (2.0g, 2.8mmol), intermediate 4 (1.8g, 3.9mmol), 2-ethoxyethanol and N,N-dimethylformamide 50mL each, replace with nitrogen three times and protect with nitrogen, heat at 100℃ for 72h. After the reaction is cooled, filter with diatomaceous earth. Wash with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify by column chromatography to obtain a yellow solid product metal complex 186 (1.2g, 43.4% yield), which is a yellow solid. The product is determined to be the target product with a molecular weight of 1006.3.

[0311] Synthesis Example 3: Synthesis of Metal Complex 243

[0312]

[0313] In a dry 500mL round-bottom flask, intermediate 2 (2.6g, 3.5mmol), intermediate 5 (2.2g, 5.3mmol), and ethanol 250mL were added in sequence, and nitrogen was replaced three times and protected with nitrogen. The reaction was heated at 100°C for 18h. After the reaction was cooled, it was filtered with diatomaceous earth. Methanol and n-hexane were washed twice respectively, and the yellow solid on the diatomaceous earth was dissolved with dichloromethane. The organic phase was collected, concentrated under reduced pressure, and purified by column chromatography to obtain a yellow solid product metal complex 243 (1.1g, 33.3% yield). The product was determined to be the target product with a molecular weight of 943.2.

[0314] Synthesis Example 4: Synthesis of Metal Complex 467

[0315] Step 1:

[0316]

[0317] 4-(Methyl-d3)-2-phenylpyridine-5-d (5.0 g, 28.9 mmol), iridium trichloride (2.6 g, 7.4 mmol), 2-ethoxyethanol (60 mL) and water (20 mL) were added to a dry 250 mL round-bottom flask in sequence, and heated to reflux under nitrogen protection and stirred for 24 h. After cooling, the mixture was filtered under reduced pressure and washed three times with methanol and n-hexane to obtain 4.0 g of yellow solid intermediate 6 (94.8% yield).

[0318] Step 2:

[0319]

[0320] In a dry 500 mL round-bottom flask, intermediate 6 (4.0 g, 3.5 mmol), anhydrous dichloromethane (250 mL), methanol (10 mL), silver trifluoromethanesulfonate (1.9 g, 7.6 mmol) were added in sequence, nitrogen was replaced three times and nitrogen was protected, and stirred at room temperature overnight. Filtered through diatomaceous earth, washed with dichloromethane twice, the organic phase below was collected and concentrated under reduced pressure to obtain 5.1 g of intermediate 7 (97.4% yield).

[0321] Step 3:

[0322]

[0323] In a dry 250mL round-bottom flask, add intermediate 8 (1.5g, 3.7mmol), intermediate 7 (2.1g, 2.2mmol), N,N-dimethylformamide 50mL, 2-ethoxyethanol 50mL, N2 protection, heat to reflux, and react for 96h. After the reaction is cooled, filter it with diatomaceous earth. Wash it with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify it by column chromatography to obtain a yellow solid product metal complex 467 (0.82g, 40.0% yield). The product is determined to be the target product with a molecular weight of 932.3.

[0324] Synthesis Example 5: Synthesis of Metal Complex 601

[0325] Step 1:

[0326]

[0327] 5-tert-butyl-2-phenylpyridine (13.2 g, 62.9 mmol), iridium trichloride trihydrate (5.5 g, 15.7 mmol), 300 mL of 2-ethoxyethanol, and 100 mL of water were added to a dry 500 mL round-bottom flask in sequence, and the nitrogen atmosphere was replaced three times and protected by nitrogen atmosphere, and heated and stirred at 130°C for 24 h. After cooling, the mixture was filtered, rinsed three times with methanol and n-hexane respectively, and dried to obtain 9.7 g of intermediate 9 (97% yield).

[0328] Step 2:

[0329]

[0330] In a dry 500 mL round-bottom flask, intermediate 9 (9.7 g, 7.7 mmol), anhydrous dichloromethane 250 mL, methanol 10 mL, silver trifluoromethanesulfonate (4.3 g, 16.7 mmol) were added in sequence, nitrogen was replaced three times and nitrogen was protected, and stirred at room temperature overnight. Celite was filtered, and dichloromethane was rinsed twice, and the organic phase below was collected and concentrated under reduced pressure to obtain 13.2 g of yellow solid intermediate 10 (93% yield).

[0331] Step 3:

[0332]

[0333] In a dry 250mL round-bottom flask, add intermediate 10 (1.4g, 1.7mmol), intermediate 3 (1.0g, 2.4mmol), 2-ethoxyethanol and N,N-dimethylformamide 50mL each, replace with nitrogen three times and protect with nitrogen, heat at 100℃ for 72h. After the reaction is cooled, filter with diatomaceous earth. Wash with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify by column chromatography to obtain a yellow solid product metal complex 601 (0.5g, 28.4% yield). The product is determined to be the target product with a molecular weight of 1034.3.

[0334] Synthesis Example 6: Synthesis of Metal Complex 604

[0335]

[0336] In a dry 250mL round-bottom flask, add intermediate 10 (2.4g, 2.9mmol), intermediate 11 (1.5g, 3.4mmol), 2-ethoxyethanol and N,N-dimethylformamide 50mL each, replace with nitrogen three times and protect with nitrogen, heat at 100℃ for 72h. After the reaction is cooled, filter with diatomaceous earth. Wash with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify by column chromatography to obtain a yellow solid product metal complex 604 (0.7g, 23.0% yield). The product is determined to be the target product with a molecular weight of 1048.4.

[0337] Synthesis Example 7: Synthesis of Metal Complex 610

[0338]

[0339] In a dry 250mL round-bottom flask, add intermediate 10 (2.2g, 2.7mmol), intermediate 12 (1.5g, 3.6mmol), 2-ethoxyethanol and N,N-dimethylformamide 50mL each, replace with nitrogen three times and protect with nitrogen, heat at 100℃ for 72h. After the reaction is cooled, filter with diatomaceous earth. Wash with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify by column chromatography to obtain a yellow solid product metal complex 610 (0.8g, 30.7% yield). The product is determined to be the target product with a molecular weight of 1034.3.

[0340] Synthesis Example 8: Synthesis of Metal Complex 646

[0341]

[0342] In a dry 250mL round-bottom flask, add intermediate 10 (2.5g, 3.0mmol), intermediate 13 (1.8g, 3.9mmol), 2-ethoxyethanol and N,N-dimethylformamide 50mL each, replace with nitrogen three times and protect with nitrogen, heat at 100℃ for 72h. After the reaction is cooled, filter with diatomaceous earth. Wash with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify by column chromatography to obtain a yellow solid product metal complex 646 (1.45g, 44.4% yield). The product is determined to be the target product with a molecular weight of 1074.4.

[0343] Synthesis Example 9: Synthesis of Metal Complex 613

[0344]

[0345] In a dry 250mL round-bottom flask, add intermediate 10 (1.9g, 2.3mmol), intermediate 14 (1.1g, 2.5mmol), 2-ethoxyethanol and N,N-dimethylformamide 50mL each, replace with nitrogen three times and protect with nitrogen, heat at 100℃ for 72h. After the reaction is cooled, filter with diatomaceous earth. Wash with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify by column chromatography to obtain a yellow solid product metal complex 613 (0.68g, 28.2% yield). The product is determined to be the target product with a molecular weight of 1048.4.

[0346] Synthesis Example 10: Synthesis of Metal Complex 636

[0347]

[0348] In a dry 250mL round-bottom flask, add intermediate 10 (3.1g, 3.7mmol), intermediate 4 (2.1g, 4.5mmol), 2-ethoxyethanol and N,N-dimethylformamide 50mL each, replace with nitrogen three times and protect with nitrogen, heat at 100℃ for 72h. After the reaction is cooled, filter with diatomaceous earth. Wash with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify by column chromatography to obtain a yellow solid product metal complex 636 (0.8g, 19.8% yield). The product is determined to be the target product with a molecular weight of 1090.4.

[0349] Synthesis Example 11: Synthesis of Metal Complex 693

[0350]

[0351] In a dry 500mL round-bottom flask, intermediate 5 (2.1g, 2.6mmol), intermediate 10 (1.5g, 3.6mmol), ethanol 300mL were added in sequence, nitrogen was replaced three times and nitrogen was protected, and the reaction was heated at 100°C for 24h. After the reaction was cooled, it was filtered on diatomaceous earth. Methanol and n-hexane were washed twice respectively, and the yellow solid on the diatomaceous earth was dissolved with dichloromethane. The organic phase was collected, concentrated under reduced pressure, and purified by column chromatography to obtain a yellow solid product metal complex 693 (1.30g, 48.7% yield). The product was determined to be the target product with a molecular weight of 1027.3.

[0352] Synthesis Example 12: Synthesis of Metal Complex 751

[0353] Step 1:

[0354]

[0355] 5-neopentyl-2-phenylpyridine (13.4 g, 59.1 mmol), iridium trichloride trihydrate (5.2 g, 14.8 mmol), 300 mL of 2-ethoxyethanol, and 100 mL of water were added to a dry 500 mL round-bottom flask in sequence, and the nitrogen atmosphere was replaced three times and protected by nitrogen. The mixture was heated and stirred at 130°C for 24 h. After cooling, the mixture was filtered, rinsed three times with methanol and n-hexane respectively, and dried to obtain 8.5 g of intermediate 15 (88% yield).

[0356] Step 2:

[0357]

[0358] In a dry 500 mL round-bottom flask, intermediate 15 (9.7 g, 7.7 mmol), anhydrous dichloromethane 250 mL, methanol 10 mL, silver trifluoromethanesulfonate (4.3 g, 16.7 mmol) were added in sequence, nitrogen was replaced three times and nitrogen was protected, and stirred at room temperature overnight. Celite was filtered, and dichloromethane was rinsed twice. The organic phase below was collected and concentrated under reduced pressure to obtain 11.8 g of yellow solid intermediate 16 (100% yield).

[0359] Step 3:

[0360]

[0361] In a dry 250mL round-bottom flask, add intermediate 16 (2.0g, 2.3mmol), intermediate 3 (1.4g, 3.2mmol), 2-ethoxyethanol and N,N-dimethylformamide 50mL each, replace with nitrogen three times and protect with nitrogen, heat at 100℃ for 72h. After the reaction is cooled, filter with diatomaceous earth. Wash with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify by column chromatography to obtain a yellow solid product metal complex 751 (0.8g, 32.7% yield). The product is determined to be the target product with a molecular weight of 1062.4.

[0362] Synthesis Example 13: Synthesis of Metal Complex 670

[0363]

[0364] In a dry 250mL round-bottom flask, add intermediate 10 (3.0g, 3.6mmol), intermediate 17 (2.7g, 6.4mmol), 2-ethoxyethanol and N,N-dimethylformamide 50mL each, replace with nitrogen three times and protect with nitrogen, heat at 100℃ for 72h. After the reaction is cooled, filter with diatomaceous earth. Wash with methanol and n-hexane twice respectively, dissolve the yellow solid on the diatomaceous earth with dichloromethane, collect the organic phase, concentrate under reduced pressure, and purify by column chromatography to obtain a yellow solid product metal complex 670 (2.7g, 72.5% yield). The product is determined to be the target product with a molecular weight of 1034.3.

[0365] Those skilled in the art should be aware that the above preparation method is only an illustrative example, and those skilled in the art can obtain other compound structures of the present invention by improving it.

[0366] Device Example 1-1

[0367] First, the glass substrate with an 80nm thick indium tin oxide (ITO) anode was cleaned and then treated with oxygen plasma and UV ozone. After treatment, the substrate was dried in a glove box to remove moisture. The substrate was then mounted on a substrate holder and loaded into a vacuum chamber. The organic layers specified below were placed in a vacuum of approximately 10 -8In the case of 1000 Å / s, the ITO anode is sequentially evaporated by thermal vacuum evaporation at a rate of 0.2-2 Å / s. Compound HI is used as a hole injection layer (HIL). Compound HT is used as a hole transport layer (HTL). Compound X-4 is used as an electron blocking layer (EBL). Then the metal complex 151 of the present invention is doped in compound X-4 and compound H-91 and co-deposited as a light-emitting layer (EML). On EML, compound H-1 is used as a hole blocking layer (HBL). On HBL, compound ET and 8-hydroxyquinoline-lithium (Liq) are co-deposited as an electron transport layer (ETL). Finally, 8-hydroxyquinoline-lithium (Liq) with a thickness of 1 nm is evaporated as an electron injection layer, and 120 nm of aluminum is evaporated as a cathode. The device is then transferred back to the glove box and encapsulated with a glass cover and a moisture absorbent to complete the device.

[0368] Device Examples 1-2

[0369] The implementation of Device Example 1-2 is the same as that of Device Example 1-1, except that the present metal complex 186 is used instead of the present metal complex 151 in the light-emitting layer.

[0370] Device Example 2-1

[0371] The implementation of Device Example 2-1 is the same as that of Device Example 1-1, except that the present metal complex 467 is used instead of the present metal complex 151 in the light-emitting layer.

[0372] Device Example 3-1

[0373] The implementation of Device Example 3-1 is the same as that of Device Example 1-1, except that the present metal complex 601 is used instead of the present metal complex 151 in the light-emitting layer.

[0374] Device Example 3-2

[0375] The implementation of Device Example 3-2 is the same as that of Device Example 1-1, except that the metal complex 604 of the present invention is used instead of the metal complex 151 of the present invention in the light-emitting layer.

[0376] Device Example 3-3

[0377] The implementation of Device Example 3-3 is the same as that of Device Example 1-1, except that the present metal complex 610 is used instead of the present metal complex 151 in the light-emitting layer.

[0378] Device Examples 3-4

[0379] The implementation of Device Example 3-4 is the same as that of Device Example 1-1, except that the present metal complex 646 is used instead of the present metal complex 151 in the light-emitting layer.

[0380] Device Examples 3-5

[0381] The implementation of Device Example 3-5 is the same as that of Device Example 1-1, except that the present metal complex 613 is used instead of the present metal complex 151 in the light-emitting layer.

[0382] Device Examples 3-6

[0383] The implementation of Device Example 3-6 is the same as that of Device Example 1-1, except that the present metal complex 636 is used instead of the present metal complex 151 in the light-emitting layer.

[0384] Device Example 4-1

[0385] The implementation of Device Example 4-1 is the same as that of Device Example 1-1, except that the present metal complex 751 is used instead of the present metal complex 151 in the light-emitting layer.

[0386] Device Example 5-1

[0387] The implementation of Device Example 5-1 is the same as that of Device Example 1-1, except that the present metal complex 243 is used instead of the present metal complex 151 in the light-emitting layer.

[0388] Device Example 6-1

[0389] The implementation of Device Example 6-1 is the same as that of Device Example 1-1, except that the present metal complex 693 is used instead of the present metal complex 151 in the light-emitting layer.

[0390] Device Comparison Example 1-1

[0391] The device comparative example 1-1 is implemented in the same manner as the device example 1-1, except that the compound GD1 is used instead of the present metal complex 151 in the light emitting layer (EML).

[0392] Device Comparison Example 2-1

[0393] The device comparative example 2-1 is implemented in the same manner as the device example 1-1, except that the compound GD2 is used instead of the present metal complex 151 in the light emitting layer (EML).

[0394] Device Comparison Example 3-1

[0395] The device comparative example 3-1 is implemented in the same manner as the device example 1-1, except that the compound GD3 is used instead of the metal complex 151 of the present invention in the light emitting layer (EML).

[0396] Device Comparison Example 4-1

[0397] The device comparative example 4-1 is implemented in the same manner as the device example 1-1, except that the compound GD4 is used instead of the present metal complex 151 in the light emitting layer (EML).

[0398] Device Comparison Example 5-1

[0399] The device comparative example 5-1 is implemented in the same manner as the device example 1-1, except that the compound GD5 is used instead of the present metal complex 151 in the light emitting layer (EML).

[0400] Device Comparison Example 6-1

[0401] The implementation of Comparative Device Example 6-1 is the same as that of Example 1-1, except that the metal complex 151 of the present invention is replaced with Compound GD6 in the light emitting layer (EML).

[0402] The detailed device layer structure and thickness are shown in the table below. For layers using more than one material, different compounds are doped in the weight ratios recorded.

[0403] Table 1 Device structures of embodiments and comparative examples

[0404]

[0405]

[0406] The material structure used in the device is shown below:

[0407]

[0408]

[0409] The IVL characteristics of the device were measured. 2 The CIE data of the device was measured below, and the maximum emission wavelength λ max , full width at half maximum (FWHM), voltage (V), current efficiency (CE), power efficiency (PE), external quantum efficiency (EQE). These data are recorded and shown in Table 2.

[0410] Table 2 Device data of the embodiment and the comparative example

[0411]

[0412]

[0413] discuss:

[0414] Table 2 shows the device performance of the embodiments and comparative examples. Compared with Comparative Example 1-1, the performance of the devices of Embodiments 1-1 to 1-2 is better than that of Comparative Example 1-1. aThe same position of the ligand is substituted with a cyano group, the only difference is that the L a The specific Ar substituent of the present invention replaces the phenyl group on the ligand, but without significant changes in the maximum emission wavelength and driving voltage, the half-peak width is narrowed by 1.7nm and 2.7nm, respectively, the CE is increased by 7.6% and 9.5%, the PE is increased by about 11.4% and 12.2%, and the EQE is increased by about 8.4% and 10.8%, respectively. In particular, the half-peak width of Example 2 reaches 35.2nm, and the EQE reaches 29.43%. At the same time, compared with Example 1-1 with unsubstituted Ar, the device of Example 1-2 with substituted Ar has further improvements in CE, PE and EQE. The above data show that the L containing specific Ar substitution and cyano substitution of the present invention a The metal complex of the ligand is superior to the complex of the comparative example in many device properties such as half-peak width, CE, PE and EQE, and significantly improves the overall performance of the device.

[0415] Similarly, Example 2-1 compared to Comparative Example 2-1, Examples 3-1 to 3-6 compared to Comparative Example 3-1, and Example 4-1 compared to Comparative Example 4-1, in the L a The same position of the ligand is substituted with a cyano group, the only difference is that the L a When the specific Ar substituent in the present invention replaces the phenyl group on the ligand, CE, PE and EQE are significantly improved, especially EQE is higher than 27.0%, reaching the industry-leading level, and there is no obvious blue-shift or red-shift in luminescence. Compared with Comparative Example 2-1, Example 2-1 has a narrower half-peak width of 3.6nm, and an improvement of EQE by about 6%; compared with Comparative Example 3-1, Examples 3-1, 3-2, 3-4, and 3-6 have narrower half-peak widths of 1.9nm, 1.1nm, 1.4nm, and 0.3nm, respectively, and an improvement of EQE by about 8.7%, 9.9%, 10.2%, and 11.9%, respectively. Although Example 3-3 has a slightly wider half-peak width of 0.2nm than Comparative Example 3-1, its EQE is improved by about 5.8%, and PE and CE are also improved by about 5%. Compared with Comparative Example 3-1, Example 3-5 has an improvement of EQE by 7.2%; compared with Comparative Example 4-1, Example 4-1 has a narrower half-peak width of 1.9nm, and an improvement of EQE by about 4%, and PE and CE are also improved by about 4%. Among these examples, especially Example 3-1, the half-peak width is only 34nm, which is very rare in green phosphorescent devices. In addition, at 80mA / cm 2Under constant current, the life (LT97) test was conducted on Examples 3-3, 3-4, 3-6 and 4-1, as well as Comparative Examples 3-1 and 4-1. Compared with Comparative Example 3-1, the device life of Examples 3-3, 3-4 and 3-6 was 38.1h, 32.01h, 31.7h and 26.8h, respectively, which were increased by 41.8%, 19.4% and 18.3%, respectively; compared with Comparative Example 4-1, the device life of Example 4-1 was 14.85h and 11.35h, respectively, which was increased by 30.8%. It can be seen from the above data that the specific Ar substitution of various structural types in the present invention is of great help in improving the important parameters such as efficiency and life of green light devices and color saturation, and significantly improves the overall performance of the device.

[0416] Compared with Comparative Example 5-1, Example 6-1 compared with Comparative Example 6-1, the L of the metal complex a The ligands have fluorine substitutions at the same positions, the only difference is that the L a The specific Ar substituent of the present invention replaces the phenyl group on the ligand, and the CE, PE, EQE and life of the device are significantly improved without significantly changing the maximum emission wavelength. In terms of EQE, Example 5-1 is improved by 12.1% compared with Comparative Example 5-1; Example 6-1 is improved by 10.5% compared with Comparative Example 6-1. At 80mA / cm 2 The lifespan (LT97) of Examples 5-1 and 6-1, as well as Comparative Examples 5-1 and 6-1, was tested under constant current. The device lifespans of Example 5-1 and Comparative Example 5-1 were 42 h and 31 h, respectively, which were increased by 23.5%; the device lifespans of Example 6-1 and Comparative Example 6-1 were 46.35 h and 40.7 h, respectively, which were increased by 13.8%. The above data show that for the fluorine-substituted La ligand complex, the present invention contains a specific Ar-substituted L a The metal complex of the ligand is superior to the complex of the comparative example in many device properties such as device life, CE, PE and EQE.

[0417] The above results show that the present invention contains L having cyano or fluorine substitution and specific Ar substitution a The metal complex of the ligand can be used as a light-emitting material in the light-emitting layer of an electroluminescent device. Compared with the L containing cyano or fluorine substitution and phenyl substitution, a The metal complex of the ligand exhibits excellent performance. By using the metal complex of the present invention, more saturated luminescence, higher luminescence efficiency, and narrower half-peak width can be provided, which can significantly improve the comprehensive performance of the device.

[0418] At the same time, the metal complex 601 of the present invention was used as a luminescent dopant and was combined with a first host compound of different structures and applied to the light-emitting layer of an organic electroluminescent device to prepare device embodiments 7-1 to 7-5, and their performance was characterized.

[0419] Device Example 7-1

[0420] The implementation method of device example 7-1 is the same as that of device example 3-1, except that the ratio of compound X-4, compound H-91 and metal complex 601 in the light-emitting layer is 66:28:6.

[0421] Device Example 7-2

[0422] Device Example 7-2 was implemented in the same manner as Device Example 7-1, except that Compound H-1 was used instead of H-91 in the light-emitting layer.

[0423] Device Example 7-3

[0424] Device Example 7-3 was implemented in the same manner as Device Example 7-1, except that Compound H-141 was used instead of H-91 in the light-emitting layer.

[0425] Device Example 7-4

[0426] Device Example 7-4 was implemented in the same manner as Device Example 7-1, except that Compound H-171 was used instead of H-91 in the light-emitting layer.

[0427] Device Example 7-5

[0428] Device Example 7-5 was implemented in the same manner as Device Example 7-1, except that Compound H-172 was used instead of H-91 in the light-emitting layer.

[0429] The detailed device layer structure and thickness are shown in the table below. For layers using more than one material, different compounds are doped in the weight ratios recorded.

[0430] Table 3 Device structures of device examples 7-1 to 7-5

[0431]

[0432] The new material structure used in the device is shown below:

[0433]

[0434] The IVL characteristics of the device were measured. 2 The CIE data of the device was measured below, and the maximum emission wavelength λ max, full width at half maximum (FWHM), voltage (V), current efficiency (CE), power efficiency (PE), external quantum efficiency (EQE). These data are recorded and shown in Table 4.

[0435] Table 4 Device data of device examples 7-1 to 7-5

[0436]

[0437] From the above data, it can be seen that the EQE of Examples 7-1 to 7-5 are all around 27%, especially the EQE of Example 7-5 reaches 28.9%; the half-peak width is less than or equal to 35nm, especially the half-peak width of Example 7-4 reaches 33.7nm, which is rare in green phosphorescent devices and is conducive to the device providing more saturated luminescence. The above shows that the present invention contains L having cyano or fluorine substitution and specific Ar substitution a The metal complex of the ligand can be used as a light-emitting material in the light-emitting layer of an electroluminescent device. When it is used in combination with a host material of different structures, excellent device performance can be achieved.

[0438] Device Example 8-1

[0439] The implementation of Device Example 8-1 is the same as that of Device Example 1-1, except that the present metal complex 670 is used instead of the present metal complex 151 in the light-emitting layer.

[0440] Device Comparison Example 8-1

[0441] The implementation method of device comparative example 8-1 is the same as that of device comparative example 8-1, except that GD7 is used instead of the metal complex 670 of the present invention in the light-emitting layer.

[0442] The detailed device layer structure and thickness are shown in the table below. For layers using more than one material, different compounds are doped in the weight ratios recorded.

[0443] Table 5 Device structures of embodiments and comparative examples

[0444]

[0445] The new material structure used in the device is shown below:

[0446]

[0447] At 100cd / m 2 The external quantum efficiency (EQE) of Example 8-1 and Comparative Example 8-1 was measured at 80 mA / cm. The EQE of Example 8-1 and Comparative Example 8-1 were 25.7% and 24.64%, respectively, which was increased by 4.3%. 2The lifespan (LT97) of Example 8-1 and Comparative Example 8-1 was tested under constant current. The device lifespans of Example 8-1 and Comparative Example 8-1 were 48.18 h and 44.17 h, respectively, which was improved by 9.1%. a The metal complex of the ligand can be used as a luminescent material in the luminescent layer of an electroluminescent device, which can provide higher luminous efficiency and longer device life, and the overall performance of the device is significantly improved.

[0448] In summary, the present invention comprises L having cyano or fluorine substitution and specific Ar substitution. a The metal complex of the ligand can be used as a luminescent material in the luminescent layer of an electroluminescent device. By using the metal complex of the present invention, more saturated luminescence, higher luminous efficiency, and narrower half-peak width can be provided, and the overall performance of the device can be significantly improved. When it is used in combination with a host material of different structures, excellent device performance can be achieved.

[0449] It should be understood that the various embodiments described herein are only examples and are not intended to limit the scope of the present invention. Therefore, as will be apparent to those skilled in the art, the claimed invention may include variations of the specific embodiments and preferred embodiments described herein. Many of the materials and structures described herein may be replaced with other materials and structures without departing from the spirit of the present invention. It should be understood that the various theories about why the present invention works are not intended to be restrictive.

Claims

1. A metal complex comprising a metal M and a ligand L coordinated with the metal M a , where L a Having a structure represented by Formula 1: In formula 1, The metal M is selected from metals with a relative atomic mass greater than 40; Cy is selected, at each occurrence, identically or differently, from a substituted or unsubstituted aromatic ring having 6 to 24 ring atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 24 ring atoms, or a combination thereof; X is selected from the group consisting of O, S, Se, NR', CR'R', SiR'R' and GeR'R'; when two R' exist at the same time, the two R' are the same or different; X1-X8 are selected from C, CR in the same or different manner at each occurrence x or N; at least one of X1-X4 is C and is connected to the Cy; X1, X2, X3 or X4 is connected to the metal M through a metal-carbon bond or a metal-nitrogen bond; At least one of X1-X8 is CR x , and the R x is cyano or fluorine; At least one of X1-X8 is CR x , and R x Ar has a structure represented by Formula 2: a is selected from 0, 1, 2, 3, 4 or 5; R a1 and R a2 Each occurrence, identically or differently, indicates mono-, poly- or non-substitution; Ring Ar1 and ring Ar2 are identically or differently selected from aromatic rings having 6-30 ring atoms, heteroaromatic rings having 5-30 ring atoms, or combinations thereof at each occurrence; and the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8; R', R x , R a1 and R a2 The group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof; "*" indicates the connection position of formula 2; The adjacent substituents R', R x , R a1 , R a2 Can optionally be linked to form a ring.

2. The metal complex according to claim 1, wherein Cy is selected from any structure in the group consisting of: in, Each occurrence of R is the same or different, indicating mono-substitution, poly-substitution, or no substitution; when multiple R are present in any structure, the R are the same or different; R is selected, at each occurrence, identically or differently, from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof; Two adjacent substituents R can optionally be linked to form a ring; Among them, '#' indicates the position connected to the metal M, Indicates a location connected to X1, X2, X3, or X4.

3. The metal complex according to claim 1 or 2, wherein Metal complexes have M(L a ) m (L b ) n (L c ) q The general formula of ; where M is selected from the group consisting of Cu, Ag, Au, Ru, Rh, Pd, Os, Ir and Pt at each occurrence, the same or different; preferably, M is selected from Pt or Ir at each occurrence, the same or different; L a , L b and L c are the first, second and third ligands coordinated to the metal M, and L c and the L a or L b are the same or different; where L a , L b and L c can optionally be linked to form a multidentate ligand; m is selected from 1, 2 or 3, n is selected from 0, 1 or 2, q is selected from 0, 1 or 2, m+n+q is equal to the oxidation state of metal M; when m is greater than or equal to 2, multiple L a The same or different; when n is equal to 2, the two L b The same or different; when q is equal to 2, the two L c Same or different; L a Each occurrence is identically or differently selected from the group consisting of: X is selected from the group consisting of O, S, Se, NR', CR'R', SiR'R' and GeR'R'; when two R' exist at the same time, the two R' are the same or different; R and R x Each occurrence is identical or different and indicates mono-, poly-, or unsubstituted; R x At least one of them is selected from cyano or fluorine; R x At least one of them is Ar, and the Ar has a structure represented by Formula 2: a is selected from 0, 1, 2, 3, 4 or 5; Ring Ar1 and ring Ar2 are identically or differently selected from aromatic rings having 6-30 ring atoms, heteroaromatic rings having 5-30 ring atoms, or combinations thereof at each occurrence; and the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8; R a1 and R a2 Each occurrence is identical or different and indicates mono-, poly-, or unsubstituted; Adjacent substituents R, R', R x , R a1 and R a2 can optionally be linked to form a ring; L b and L c Each occurrence is identically or differently selected from any one of the following groups: in, X b Each occurrence is identically or differently selected from the group consisting of: O, S, Se, NR N1 , CR C1 R C2 ; R a and R b Each occurrence is identical or different and indicates mono-, poly-, or unsubstituted; R, R', R a1 , R a2 , R x , R a , R b , R c , R N1 , R C1 and R C2 The group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof; Adjacent substituent R a , R b , R c , R N1 , R C1 and R C2 can optionally be linked to form a ring; "*" indicates the connection position of formula 2.

4. The metal complex according to claim 1 or 2, wherein Metal complex Ir(L a ) m (L b ) 3-m Having a structure represented by Formula 3: in, m is selected from 1, 2 or 3; when m is selected from 1, two L b The same or different; when m is selected from 2 or 3, multiple L a Same or different; X is selected from the group consisting of O, S, Se, NR', CR'R', SiR'R' and GeR'R'; when two R' exist at the same time, the two R' are the same or different; Each occurrence of Y1-Y4 is identical or different and is selected from CR y or N; X3-X8 are selected from CR in the same or different way each time they appear x or N; At least one of X3-X8 is CR x , and the R x is cyano or fluorine; At least one of X3-X8 is CR x , and R x Ar has a structure represented by Formula 2: a is selected from 0, 1, 2, 3, 4 or 5; R a1 and R a2 The same or different at each occurrence indicates mono-, poly- or no-substitution; Ring Ar1 and ring Ar2 are identically or differently selected from aromatic rings having 6-30 ring atoms, heteroaromatic rings having 5-30 ring atoms, or combinations thereof at each occurrence; and the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8; R', R x , R y , R1-R8, R a1 and R a2 The group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amine group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof; "*" indicates the connection position of formula 2; The adjacent substituents R', R x , R y , R a1 , R a2 can optionally be linked to form a ring; Adjacent substituents R1 to R8 can optionally be linked to form a ring.

5. The metal complex according to any one of claims 1 to 4, wherein X is selected from O or S, a is selected from 0, 1, 2 or 3; Preferably, a is 1.

6. The metal complex according to claim 4, wherein X3-X8 is the same or different selection from CR each time it appears x ; and / or Each occurrence of Y1-Y4 is the same or different and is selected from CR y .

7. The metal complex according to claim 4, wherein At least one of X3-X8 is N, and / or at least one of Y1-Y4 is N.

8. The metal complex according to any one of claims 1 to 7, wherein At least one of X5-X8 is CR x , and the R x is cyano or fluorine; at least one of X5-X8 is CR x , and the R x It is Ar; Preferably, X7 and X8 are selected from CR x , and one of the R x is selected from cyano or fluorine, the other R x It is Ar; More preferably, X7 is CR x , and the R x is cyano or fluorine; X8 is selected from CR x , and the R x It's Ar.

9. The metal complex according to any one of claims 1 to 8, wherein R a1 and R a2 each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, cyano, isocyano, hydroxyl, mercapto, and combinations thereof; Preferably, R a1 and R a2 each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, fluorine, substituted or unsubstituted alkyl having 1 to 6 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 6 ring carbon atoms, substituted or unsubstituted aryl having 6 to 18 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 18 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 15 carbon atoms, and combinations thereof; More preferably, R a1 and R a2 Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, fluorine, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopentyl, cyclohexyl, deuterated methyl, deuterated ethyl, deuterated propyl, deuterated isopropyl, deuterated n-butyl, deuterated isobutyl, deuterated tert-butyl, deuterated cyclopentyl, deuterated cyclohexyl, phenyl, pyridyl, trimethylsilyl, and combinations thereof.

10. The metal complex according to any one of claims 1 to 9, wherein in Ar, ring Ar1 and ring Ar2 are each identically or differently selected from an aromatic ring having 6 ring atoms, a heteroaromatic ring having 5 or 6 ring atoms, or a combination thereof; Preferably, ring Ar1 and ring Ar2 are each identically or differently selected from aromatic or heteroaromatic rings having 6 ring atoms; More preferably, ring Ar1 and ring Ar2 are selected, identically or differently, on each occurrence from aromatic rings having 6 ring atoms.

11. The metal complex according to any one of claims 1 to 9, wherein in Ar, ring Ar1 and ring Ar2 are identically or differently selected from aromatic rings having 6 to 18 ring atoms, heteroaromatic rings having 5 to 18 ring atoms, or a combination thereof each time they appear; and the total number of ring atoms in ring Ar1 and ring Ar2 is greater than or equal to 8 and less than or equal to 30; Preferably, in Ar, ring Ar1 and ring Ar2 are selected from the group consisting of: benzene ring, pyridine ring, pyrimidine ring, triazine ring, naphthalene ring, phenanthrene ring, anthracene ring, fluorene ring, silylene ring, quinoline ring, isoquinoline ring, dithiophene ring, difuran ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, triphenylene ring, carbazole ring, azacarbazole ring, azafluorene ring, azasilylene ring, azadibenzofuran ring, azadibenzothiophene ring, and combinations thereof at each occurrence; and the total number of ring atoms of ring Ar1 and ring Ar2 is greater than or equal to 8 and less than or equal to 30.

12. The metal complex according to any one of claims 1 to 9, wherein Ar at each occurrence is identically or differently selected from the group consisting of: and combinations thereof; Optionally, the hydrogen in the above groups can be partially or completely replaced by deuterium; wherein "*" indicates the connection position of the Ar.

13. The metal complex according to any one of claims 1 to 12, wherein The R x At least one of them is selected from cyano or fluorine, R x At least one of them is selected from Ar, and the rest R x each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, cyano, and combinations thereof; Preferably, R x At least one of them is selected from cyano or fluorine, R x At least one of them is selected from Ar, and the rest R x each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, fluorine, substituted or unsubstituted alkyl having 1 to 6 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 6 ring carbon atoms, substituted or unsubstituted aryl having 6 to 12 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 12 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 6 carbon atoms, cyano, and combinations thereof; More preferably, R x At least one of them is selected from cyano or fluorine, R x At least one of them is selected from Ar, and the rest R x Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, substituted or unsubstituted alkyl having 1 to 6 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 6 ring carbon atoms, and combinations thereof.

14. The metal complex according to claim 4, wherein R y each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aralkyl having 7-30 carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl having 3-20 carbon atoms, substituted or unsubstituted arylsilyl having 6-20 carbon atoms, and combinations thereof; Preferably, at least one R y Selected from the group consisting of deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl having 3-20 ring carbon atoms, substituted or unsubstituted aryl having 6-30 carbon atoms, substituted or unsubstituted heteroaryl having 3-30 carbon atoms, and combinations thereof.

15. The metal complex according to claim 4, wherein At least one, at least two, at least three, or all of R2, R3, R6, and R7 are selected from the group consisting of deuterium, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, and combinations thereof; Preferably, at least one, at least two, at least three, or all of R2, R3, R6, and R7 are selected from the group consisting of deuterium, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, and combinations thereof; More preferably, at least one, at least two, at least three or all of R2, R3, R6, and R7 are selected from the group consisting of deuterium, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopentyl, cyclohexyl, neopentyl, tert-pentyl, and combinations thereof; optionally, the hydrogen in the above groups can be partially or completely deuterated.

16. The metal complex according to claim 1, wherein L a Each occurrence is identically or differently selected from the group consisting of:

17. The metal complex according to claim 3 or 16, wherein L b Each occurrence is identically or differently selected from the group consisting of:

18. The metal complex according to claim 3 or 17, wherein L c Each occurrence is identically or differently selected from the group consisting of:

19. The metal complex according to claim 18, wherein The metal complex has Ir(L a )2(L b ) or Ir(L a )(L b )2 or Ir(L a )3 structure, where L a Each time it appears, choose the same or different one from L a1 To L a955 Any one, any two, or any three of the group consisting of L b Choose from L b1 To L b128 Any one or two of the groups consisting of; Or the metal complex has Ir(L a )2(L c ) or Ir(L a )(L c )2 structure, where L a Each time it appears, choose the same or different one from L a1 To L a955 Any one or two of the group consisting of L c Choose from L c1 To L c360 Any one or two of the groups consisting of; Or the metal complex has Ir(L a )(L b )(L c ) structure, where L a Each time it appears, choose the same or different one from L a1 To L a955 Any of the groups consisting of L b Choose from L b1 To L b128 Any of the groups consisting of L c Choose from L c1 To L c360 Any of the groups consisting of; Preferably, the metal complex is selected from the group consisting of metal complex 1 to metal complex 1216, wherein metal complex 1 to metal complex 1216 have IrL a (L b )2 structure, where two L b Same, where L a and L b They correspond to the structures shown in the following table:

20. An electroluminescent device comprising: anode, cathode, and an organic layer disposed between an anode and a cathode, wherein the organic layer comprises the metal complex according to any one of claims 1 to 19.

21. The electroluminescent device of claim 20, wherein: The organic layer including the metal complex is a light-emitting layer.

22. The electroluminescent device of claim 21, wherein: The electroluminescent device emits green light or white light.

23. The electroluminescent device of claim 21, wherein: The light-emitting layer comprises a first host compound; Preferably, the light-emitting layer further comprises a second host compound; More preferably, the first main compound and / or the second main compound comprises at least one chemical group selected from the group consisting of benzene, pyridine, pyrimidine, triazine, carbazole, azacarbazole, indolecarbazole, dibenzothiophene, azadibenzothiophene, dibenzofuran, azadibenzofuran, dibenzoselenophene, triphenylene, azatriphenylene, fluorene, silafluorene, naphthalene, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene, azaphenanthrene, and combinations thereof.

24. The electroluminescent device of claim 23, wherein: The first host compound has a structure represented by Formula 4: in, Each occurrence of E1-E6 is selected from C, CR e or N, and at least two of E1-E6 are N, and at least one of E1-E6 is C, and is connected to formula A; in, Q is the same or different each time it appears and is selected from the group consisting of O, S, Se, N, NR", CR"R", SiR"R", GeR"R" and R"C=CR"; when two R" are present at the same time, the two R" can be the same or different; p is 0 or 1; r is 0 or 1; When Q is selected from N, p is 0 and r is 1; When Q is selected from the group consisting of O, S, Se, NR", CR"R", SiR"R", GeR"R" and R"C=CR", p is 1 and r is 0; L is identically or differently selected at each occurrence from a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 20 carbon atoms, or a combination thereof; Q1-Q8 are selected from C, CR in the same or different manner at each occurrence q or N; R e , R' and R q Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted Alkynyl groups having 2 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermanyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanyl groups having 6 to 20 carbon atoms, substituted or unsubstituted amine groups having 0 to 20 carbon atoms, acyl groups, carbonyl groups, carboxylic acid groups, ester groups, cyano groups, isocyano groups, hydroxyl groups, mercapto groups, sulfinyl groups, sulfonyl groups, phosphino groups, and combinations thereof; "*" represents the connection position between Formula A and Formula 4; Adjacent substituent R e , R”, R q Can optionally be linked to form a ring.

25. The electroluminescent device of claim 24, wherein each occurrence of E1-E6 is identically or differently selected from C, CR e or N, and three of E1-E6 are N, and at least one of E1-E6 is CR e , and the R e Each occurrence is identically or differently selected from the group consisting of substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, and combinations thereof; and / or Q is selected, identically or differently, at each occurrence, from O, S, N or NR"; and / or at least one or at least two of Q1-Q8 are selected from CR q , and the R q is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 carbon atoms, or a combination thereof; and / or L is identically or differently selected at each occurrence from a single bond, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 20 carbon atoms, or a combination thereof.

26. The electroluminescent device of claim 24, wherein: The first host compound is selected from the group consisting of:

27. The electroluminescent device of claim 23, wherein: The second host compound has a structure represented by Formula 5: in, L x is selected, at each occurrence, identically or differently, from a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 20 carbon atoms, or a combination thereof; Each occurrence of V is selected from C, CR v or N, and at least one of V is C, and L x connect; Each occurrence of U is selected from C, CR, or u or N, and at least one of U is C, and L x connect; R v and R u Each occurrence is identically or differently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted Alkynyl groups having 2 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermanyl groups having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanyl groups having 6 to 20 carbon atoms, substituted or unsubstituted amine groups having 0 to 20 carbon atoms, acyl groups, carbonyl groups, carboxylic acid groups, ester groups, cyano groups, isocyano groups, hydroxyl groups, mercapto groups, sulfinyl groups, sulfonyl groups, phosphino groups, and combinations thereof; Ar6 is selected, at each occurrence, identically or differently, from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, or a combination thereof; Adjacent substituent R v and R u can optionally be linked to form a ring; Preferably, the second host compound has a structure represented by one of Formula 5-a to Formula 5-j:

28. The electroluminescent device of claim 27, wherein: The second host compound is selected from the group consisting of:

29. The electroluminescent device according to claim 23, wherein a metal complex is doped in the first host compound and the second host compound, and the weight of the metal complex accounts for 1% to 30% of the total weight of the light-emitting layer; Preferably, the weight of the metal complex accounts for 3% to 13% of the total weight of the light-emitting layer.

30. A compound combination comprising the metal complex according to any one of claims 1 to 19.

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