CN116836204A

CN116836204A - Organic electroluminescent material and device thereof

Info

Publication number: CN116836204A
Application number: CN202310795245.7A
Authority: CN
Inventors: 蔡维; 刘佳乐; 王珍; 李宏博; 王峥; 邝志远; 夏传军
Original assignee: Beijing Summer Sprout Technology Co Ltd
Current assignee: Beijing Summer Sprout Technology Co Ltd
Priority date: 2023-06-30
Filing date: 2023-06-30
Publication date: 2023-10-03

Abstract

Disclosed are an organic electroluminescent material which is an L comprising a structure represented by formula 1A _a Ligand and L of the structure represented by formula 1B _b The metal complex of the ligand can be used as a luminescent material in a luminescent layer of an organic electroluminescent device. The metal complexes with these novel ligands enable a substantial improvement in device efficiency. These novel metal complexes can provide better device performance. An electroluminescent device comprising the metal complex and a compound composition comprising the metal complex are also disclosed.

Description

Organic electroluminescent material and device thereof

Technical Field

The present invention relates to compounds for use in organic electronic devices, such as organic light emitting devices. More particularly, it relates to a composition comprising a structure represented by formula 1AL of (2) _a Ligand and L of the structure represented by formula 1B _b Metal complexes of ligands, electroluminescent devices and compound compositions comprising the same.

Background

Organic electronic devices include, but are not limited to, the following: organic Light Emitting Diodes (OLEDs), organic field effect transistors (O-FETs), organic light emitting transistors (OLEDs), 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 electroluminescent devices.

In 1987, tang and Van Slyke of Isomandah reported a double-layered organic electroluminescent device comprising an arylamine hole transport layer and a tris-8-hydroxyquinoline-aluminum layer as an electron transport layer and a light emitting layer (Applied Physics Letters,1987,51 (12): 913-915). Once biased into the device, green light is emitted from the device. The invention lays a foundation for the development of modern Organic Light Emitting Diodes (OLEDs). Most advanced OLEDs may 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 anode. Because OLEDs are self-emitting solid state devices, they offer great potential for display and lighting applications. Furthermore, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications, such as fabrication on flexible substrates.

OLEDs can be divided into three different types according to their light emission mechanism. The OLED of the Tang and van Slyke invention is a fluorescent OLED. It uses only singlet light emission. The triplet states generated in the device are wasted through non-radiative decay channels. Thus, the Internal Quantum Efficiency (IQE) of fluorescent OLEDs is only 25%. This limitation prevents commercialization of OLEDs. In 1997, forrest and Thompson reported phosphorescent OLEDs using triplet emission from heavy metals containing complexes as emitters. Thus, both singlet and triplet states can be harvested, achieving a 100% IQE. Because of its high efficiency, the discovery and development of phosphorescent OLEDs has contributed directly to the commercialization of Active Matrix OLEDs (AMOLEDs). Recently, adachi achieved high efficiency by Thermally Activated Delayed Fluorescence (TADF) of organic compounds. These emitters have a small singlet-triplet gap, making it possible for excitons to return from the triplet state to the singlet state. In TADF devices, triplet excitons can generate singlet excitons by reverse intersystem crossing, resulting in high IQE.

OLEDs can also be classified into small molecule and polymeric OLEDs depending on the form of the materials used. Small molecule refers to any organic or organometallic material that is not a polymer. The molecular weight of the small molecules can be large as long as they have a precise structure. Dendrimers with a defined structure are considered small molecules. Polymeric OLEDs include conjugated polymers and non-conjugated polymers having pendant luminescent groups. Small molecule OLEDs can become polymeric OLEDs if post-polymerization occurs during fabrication.

Various methods of OLED fabrication exist. Small molecule OLEDs are typically fabricated by vacuum thermal evaporation. Polymeric OLEDs are manufactured by solution processes such as spin coating, inkjet printing and nozzle printing. Small molecule OLEDs can also be fabricated by solution processes if the material can be dissolved or dispersed in a solvent.

The emission color of an OLED can be achieved by the structural design of the luminescent material. The OLED may include a light emitting layer or layers to achieve a desired spectrum. Green, yellow and red OLEDs, phosphorescent materials have been successfully commercialized. Blue phosphorescent devices still have problems of blue unsaturation, short device lifetime, high operating voltage, and the like. Commercial full color OLED displays typically employ a mixing strategy using blue fluorescent and phosphorescent yellow, or red and green. Currently, a rapid decrease in efficiency of phosphorescent OLEDs at high brightness remains a problem. In addition, it is desirable to have a more saturated emission spectrum, higher efficiency and longer device lifetime.

US2020251666A1 discloses a metal complex comprising a ligand structure having the structure shown below:

having the following structureA metal complex of the general structure:

although a specific structure is disclosed in the embodiments thereof However, this application does not disclose a metal complex having other rings attached to Cy, nor does it disclose the effect of a metal complex having other rings attached to Cy on device performance.

In order to meet the increasingly improved requirements of the industry on various performances of electroluminescent devices, such as light emitting color, driving voltage, light emitting efficiency, etc., research on phosphorescent devices is still needed.

Disclosure of Invention

The present invention aims to provide a series of L comprising the structure of 1A _a Ligand and L of structure 1B _b Metal complexes of ligands to solve at least part of the above problems. The metal complex can be used as a luminescent material in an organic electroluminescent device. The novel compounds can be applied to electroluminescent devices, and can improve the luminous performance and efficiency of the devices and obviously improve the comprehensive performance of the devices.

According to one embodiment of the present invention, a metal complex is disclosed having M (L _a ) _m( L _b ) _n Is represented by the general formula (I),

wherein, the liquid crystal display device comprises a liquid crystal display device,

L _a 、L _b a first ligand, a second ligand coordinated to the metal M, and L _a And L _b Is different; wherein L is _a 、L _b Can optionally be linked to form a multidentate ligand;

wherein M is 1 or 2, n is 1 or 2, m+n is equal to the oxidation state of M; when m is 2, two L _a The same or different; when n is 2, two L _b The same or different;

the metal M is selected from metals with relative atomic mass of more than 40;

L _a each occurrence of which is the same or different, has a structure represented by formula 1A; l (L) _b Each occurrence of which is the same or different, has a structure represented by formula 1B;

G ₁ and G ₂ Each occurrence of which is identically or differently selected from a single bond, O or S;

x is selected from the group consisting of O, S, se, NR ', siR ' R ' and GeR ' R '; when two R's are present at the same time, the two R's are the same or different;

ring Cx, ring Cy, ring Cw, ring Cz are identically or differently selected for each occurrence from a substituted or unsubstituted aromatic ring having from 6 to 24 ring atoms, a substituted or unsubstituted heteroaromatic ring having from 5 to 24 ring atoms, or a combination thereof;

X ₁ -X ₈ is selected from CR, identically or differently at each occurrence _x ，CR _x1 C or N, and X ₁ -X ₈ At least one of them is selected from CR _x1 And said R _x1 Cyano or fluoro;

R _n ，R ₁ ，R ₂ and R is ₃ Each occurrence, identically or differently, represents mono-, poly-or unsubstituted;

R’，R _x ，R _n ，R ₁ ，R ₂ and R is ₃ And is selected identically or differently on each occurrence 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 aryl having 6 to 30 carbon atoms Alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 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, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermanium having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanium having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

adjacent substituents R', R _x ，R _n ，R ₁ ，R ₂ ，R ₃ Can optionally be linked to form a ring.

According to another embodiment of the present invention, there is also disclosed an organic electroluminescent device including: an anode, a cathode, and an organic layer disposed between the anode and the cathode, the organic layer comprising the metal complex described in the above embodiments.

According to another embodiment of the present invention, there is also disclosed a compound composition comprising the metal complex described in the above embodiment.

The present invention is directed to a series of L's comprising the structure represented by formula 1A _a Ligand and L of the structure represented by formula 1B _b Metal complexes of ligands. The novel metal complexes can be applied to organic electroluminescent devices to improve the device efficiency, are beneficial to improving the comprehensive performance of the devices, and have great advantages and wide prospects in industrial application.

Drawings

Fig. 1 is a schematic view of an organic light emitting device that may contain the metal complex and compound compositions disclosed herein.

Fig. 2 is a schematic view of another organic light emitting device that may contain the metal complex and compound compositions disclosed herein.

Detailed Description

OLEDs can be fabricated on a variety of substrates, such as glass, plastic, and metal. Fig. 1 schematically illustrates, without limitation, an organic light-emitting device 100. The drawings are not necessarily to scale, and some of the layer structures in the drawings may be omitted as desired. 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 may be fabricated by sequentially depositing the layers described. The nature and function of the layers and exemplary materials are described in more detail in U.S. patent US7,279,704B2, columns 6-10, the entire contents of which are incorporated herein by reference.

There are more instances 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 doped with F in a 50:1 molar ratio ₄ m-MTDATA of TCNQ as disclosed in U.S. patent application publication No. 2003/0230980, which is incorporated by reference in its entirety. Examples of host materials are disclosed in U.S. Pat. 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 in 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. Examples of cathodes are disclosed in U.S. Pat. nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entirety, including composite cathodes having a thin layer of metal, such as Mg: ag, with an overlying transparent, electrically 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 implant 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.

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

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.

The OLED also requires an encapsulation layer, such as the organic light emitting device 200 shown schematically and without limitation in fig. 2, which differs from fig. 1 in that an encapsulation layer 102 may also be included over the cathode 190 to prevent harmful substances from the environment, such as moisture and oxygen. Any material capable of providing an encapsulation function may be used as the encapsulation layer, such as glass or an organic-inorganic hybrid layer. The encapsulation layer should be placed directly or indirectly outside the OLED device. Multilayer film packages are described in U.S. patent US7,968,146B2, the entire contents of which are incorporated herein by reference.

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

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

As used herein, "top" means furthest from the substrate and "bottom" means closest to the substrate. In the case where the first layer is described as being "disposed" on "the second layer, the first layer is disposed farther from the substrate. Unless a first layer is "in contact with" a second layer, other layers may be present between the first and second layers. For example, a cathode may be described as "disposed on" an anode even though various organic layers are present between the cathode and the anode.

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.

A ligand may be referred to as "photosensitive" when it is believed that the ligand directly contributes to the photosensitive properties of the emissive material. When it is believed that the ligand does not contribute to the photosensitive properties of the emissive material, the ligand may be referred to as "ancillary," but ancillary ligands may alter the properties of the photosensitive ligand.

It is believed that the Internal Quantum Efficiency (IQE) of fluorescent OLEDs can be limited by spin statistics that delay fluorescence by more than 25%. Delayed fluorescence can be generally classified into two types, i.e., P-type delayed fluorescence and E-type delayed fluorescence. The P-type delayed fluorescence is generated by triplet-triplet annihilation (TTA).

On the other hand, the E-type delayed fluorescence does not depend on the collision of two triplet states, but on the transition between the triplet states and the singlet excited state. Compounds capable of generating E-type delayed fluorescence need to have very small mono-triplet gaps in order for the conversion between the energy states. The thermal energy may activate a transition from the triplet state back to the singlet state. This type of delayed fluorescence is also known as Thermally Activated Delayed Fluorescence (TADF). A significant feature of TADF is that the delay component increases with increasing temperature. The fraction of backfill singlet excited states may reach 75% if the reverse intersystem crossing (RISC) rate is fast enough to minimize non-radiative decay from the triplet states. The total singlet fraction may be 100%, well in excess of 25% of the spin statistics of the electrically generated excitons.

Type E delayed fluorescence features can be found in excitation complex systems or in single compounds. Without being bound by theory, it is believed that E-delayed fluorescence requires a luminescent material with a small mono-triplet energy gap (Δe _S-T ). Organic non-metal containing donor-acceptor luminescent materials may be able to achieve this. These materialsIs generally characterized as a donor-acceptor Charge Transfer (CT) type emission. The spatial separation of HOMO from LUMO in these donor-acceptor compounds generally results in a small Δe _S-T . These states may include CT states. Typically, donor-acceptor luminescent materials are constructed by linking an electron donor moiety (e.g., an amino or carbazole derivative) to an electron acceptor moiety (e.g., an N-containing six-membered aromatic ring).

Definition of terms for substituents

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

Alkyl-as used herein, includes straight and branched chain 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, 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.

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

Heteroalkyl-as used herein, a heteroalkyl comprises an alkyl chain in which one or more carbons is replaced by a heteroatom selected from the group consisting of nitrogen, oxygen, sulfur, selenium, phosphorus, silicon, germanium, and boron. The heteroalkyl group may be a heteroalkyl group having 1 to 20 carbon atoms, preferably a heteroalkyl group having 1 to 10 carbon atoms, more preferably a heteroalkyl group having 1 to 6 carbon atoms. Examples of heteroalkyl groups include methoxymethyl, ethoxymethyl, ethoxyethyl, methylthiomethyl, ethylthiomethyl, ethylthioethyl, methoxymethoxymethyl, ethoxymethoxymethyl, ethoxyethoxyethyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, mercaptomethyl, mercaptoethyl, mercaptopropyl, aminomethyl, aminoethyl, aminopropyl, dimethylaminomethyl, trimethylgermylmethyl, trimethylgermylethyl, dimethylethylgermylmethyl, dimethylisopropylgermylmethyl, t-butyldimethylgermylmethyl, triethylgermylmethyl, triethylgermylethyl, triisopropylgermylmethyl, triisopropylgermylethyl, trimethylsilylmethyl, trimethylsilylethyl, trimethylsilylisopropyl, triisopropylsilylmethyl. In addition, heteroalkyl groups may be optionally substituted.

Alkenyl-as used herein, covers straight chain, branched chain, and cyclic alkylene groups. Alkenyl groups may be alkenyl groups containing 2 to 20 carbon atoms, preferably alkenyl groups having 2 to 10 carbon atoms. Examples of alkenyl groups include ethenyl, propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1, 3-butadienyl, 1-methylvinyl, styryl, 2-diphenylvinyl, 1-methallyl, 1-dimethylallyl, 2-methallyl, 1-phenylallyl, 2-phenylallyl, 3-diphenylallyl, 1, 2-dimethylallyl, 1-phenyl-1-butenyl, 3-phenyl-1-butenyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cycloheptenyl, cycloheptatrienyl, cyclooctenyl, cyclooctatetraenyl and norbornenyl. In addition, alkenyl groups may be optionally substituted.

Alkynyl-as used herein, straight chain alkynyl is contemplated. The alkynyl group may be an alkynyl group containing 2 to 20 carbon atoms, preferably an alkynyl group having 2 to 10 carbon atoms. Examples of alkynyl groups include ethynyl, propynyl, propargyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-dimethyl-1-butynyl, 3-ethyl-3-methyl-1-pentynyl, 3-diisopropyl-1-pentynyl, phenylethynyl, phenylpropynyl and the like. Among the above, preferred are ethynyl, propynyl, propargyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl and phenylethynyl. In addition, alkynyl groups may be optionally substituted.

Aryl or aromatic-as used herein, 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, more preferably an aryl group having 6 to 12 carbon atoms. Examples of the aryl group include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, 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-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, o-tolyl, m-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-tetrabiphenyl. In addition, aryl groups may be optionally substituted.

Heterocyclyl or heterocycle-as used herein, non-aromatic cyclic groups are contemplated. The non-aromatic heterocyclic group includes a saturated heterocyclic group having 3 to 20 ring atoms and an unsaturated non-aromatic heterocyclic group having 3 to 20 ring atoms, at least one of which is selected from the group consisting of nitrogen atom, oxygen atom, sulfur atom, selenium atom, silicon atom, phosphorus atom, germanium atom and boron atom, and preferred non-aromatic heterocyclic groups are those having 3 to 7 ring atoms including at least one hetero atom such as nitrogen, oxygen, silicon or sulfur. Examples of non-aromatic heterocyclic groups include oxiranyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxanyl, aziridinyl, dihydropyrrolyl, tetrahydropyrrolyl, piperidinyl, oxazolidinyl, morpholinyl, piperazinyl, oxacycloheptatrienyl, thietaneyl, azepanyl and tetrahydrosilol. In addition, the heterocyclic group may be optionally substituted.

Heteroaryl-as used herein, non-fused and fused heteroaromatic groups that may contain 1 to 5 heteroatoms, at least one of which is selected from the group consisting of nitrogen atoms, oxygen atoms, sulfur atoms, selenium atoms, silicon atoms, phosphorus atoms, germanium atoms, and boron atoms. Heteroaryl also refers to heteroaryl. The heteroaryl group may be a heteroaryl group having 3 to 30 carbon atoms, preferably a heteroaryl group having 3 to 20 carbon atoms, more preferably a heteroaryl group having 3 to 12 carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridine indole, pyrrolopyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indenoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, benzofuranopyridine, furodipyridine, benzothiophene, thienodipyridine, benzoselenophene, selenodipyridine, preferably dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 1, 2-aza-boron, 1, 3-aza-boron, 1-aza-boron-4-aza, boron-doped compounds, and the like. In addition, heteroaryl groups may be optionally substituted.

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

Aryloxy-as used herein, is represented by-O-aryl or-O-heteroaryl. Examples and preferred examples of aryl and heteroaryl groups are the same as described above. The aryloxy group may be an aryloxy group having 6 to 30 carbon atoms, preferably an aryloxy group having 6 to 20 carbon atoms. Examples of aryloxy groups include phenoxy and biphenoxy. In addition, the aryloxy group may be optionally substituted.

Aralkyl-as used herein, encompasses aryl-substituted alkyl. The aralkyl group may be an aralkyl group having 7 to 30 carbon atoms, preferably an aralkyl group having 7 to 20 carbon atoms, more preferably an aralkyl group 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, o-methylbenzyl, p-chlorobenzyl, m-chlorobenzyl, o-chlorobenzyl, p-bromobenzyl, m-bromobenzyl, o-bromobenzyl, p-iodobenzyl, m-iodobenzyl, o-iodobenzyl, p-hydroxybenzyl, m-hydroxybenzyl, o-aminobenzyl, m-aminobenzyl, o-aminobenzyl, p-nitrobenzyl, m-nitrobenzyl, o-nitrobenzyl, p-cyanobenzyl, m-cyanobenzyl, cyano, o-cyanobenzyl, o-chlorobenzyl, 1-chlorophenyl and 1-isopropyl. Among the above, preferred are benzyl, p-cyanobenzyl, m-cyanobenzyl, o-cyanobenzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl and 2-phenylisopropyl. In addition, aralkyl groups may be optionally substituted.

Alkyl-as used herein, alkyl-substituted silicon groups are contemplated. The silyl group may be a silyl group having 3 to 20 carbon atoms, preferably a silyl group having 3 to 10 carbon atoms. Examples of the alkyl silicon group include trimethyl silicon group, triethyl silicon group, methyldiethyl silicon group, ethyldimethyl silicon group, tripropyl silicon group, tributyl silicon group, triisopropyl silicon group, methyldiisopropyl silicon group, dimethylisopropyl silicon group, tri-t-butyl silicon group, triisobutyl silicon group, dimethyl-t-butyl silicon group, and methyldi-t-butyl silicon group. In addition, the alkyl silicon group may be optionally substituted.

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

Alkyl germanium group-as used herein, alkyl substituted germanium groups are contemplated. The alkylgermanium group may be an alkylgermanium group having 3 to 20 carbon atoms, preferably an alkylgermanium group having 3 to 10 carbon atoms. Examples of alkyl germanium groups include trimethyl germanium group, triethyl germanium group, methyl diethyl germanium group, ethyl dimethyl germanium group, tripropyl germanium group, tributyl germanium group, triisopropyl germanium group, methyl diisopropyl germanium group, dimethyl isopropyl germanium group, tri-t-butyl germanium group, triisobutyl germanium group, dimethyl-t-butyl germanium group, methyl-di-t-butyl germanium group. In addition, alkyl germanium groups may be optionally substituted.

Arylgermanium group-as used herein, encompasses at least one aryl or heteroaryl substituted germanium group. The arylgermanium group may be an arylgermanium group having 6-30 carbon atoms, preferably an arylgermanium group having 8 to 20 carbon atoms. Examples of aryl germanium groups include triphenylgermanium group, phenylbiphenyl germanium group, diphenylbiphenyl germanium group, phenyldiethyl germanium group, diphenylethyl germanium group, phenyldimethyl germanium group, diphenylmethyl germanium group, phenyldiisopropylgermanium group, diphenylisopropylgermanium group, diphenylbutylgermanium group, diphenylisobutylglycol group, and diphenyltert-butylgermanium group. In addition, the arylgermanium group may be optionally substituted.

The term "aza" in azadibenzofurans, azadibenzothiophenes and the like means that one or more C-H groups in the corresponding aromatic fragment are replaced by a nitrogen atom. For example, azatriphenylenes include dibenzo [ f, h ] quinoxalines, dibenzo [ f, h ] quinolines, and other analogs having two or more nitrogens in the ring system. Other nitrogen analogs of the above-described aza derivatives will be readily apparent to those of ordinary skill in the art, and all such analogs are intended to be included in the terms described herein.

In the present disclosure, when any one of the terms from 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 alkylgermanium, substituted arylgermanium, substituted amino, substituted acyl, substituted carbonyl, substituted carboxylic acid, substituted ester, substituted sulfinyl, substituted sulfonyl, substituted phosphino, alkyl, cycloalkyl, heteroalkyl, heterocyclyl, aralkyl, alkoxy, aryloxy, alkenyl, alkynyl, aryl, heteroaryl, alkylsilyl, arylsilyl, amino, acyl, carbonyl, carboxylic acid, ester, sulfinyl, sulfonyl and phosphino groups, which may be substituted with one or more groups selected from the group consisting of deuterium, halogen, unsubstituted alkyl having 1 to 20 carbon atoms, unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, unsubstituted cycloalkyl having 1 to 20 carbon atoms, unsubstituted alkenyl having 3 to 20 carbon atoms, unsubstituted aryl having 3 to 20 carbon atoms, unsubstituted alkenyl having 3 to 30 carbon atoms, unsubstituted aryl having 3 to 20 carbon atoms, unsubstituted alkenyl having 3 to 20 carbon atoms, unsubstituted aryl having 3 to 30 carbon atoms, unsubstituted aryl having 3 to 20 carbon atoms, unsubstituted aryl having 3 to 30 carbon atoms, unsubstituted alkylgermanium groups having 3 to 20 carbon atoms, unsubstituted arylgermanium groups having 6 to 20 carbon atoms, unsubstituted amino 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, phosphine groups, and combinations thereof.

It will be appreciated that when a fragment of a molecule is described as a substituent or otherwise attached to another moiety, its name may be written according to whether it is a fragment (e.g., phenyl, phenylene, naphthyl, dibenzofuranyl) or according to whether it is an entire molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, these different ways of specifying substituents or linking fragments are considered equivalent.

In the compounds mentioned in this disclosure, the 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. Substitution of other stable isotopes in the compounds may be preferred because of their enhanced efficiency and stability of the device.

In the compounds mentioned in this disclosure, polysubstituted means inclusive of disubstituted up to the maximum available substitution range. When a substituent in a compound mentioned in this disclosure means multiple substitution (including di-substitution, tri-substitution, tetra-substitution, etc.), it means that the substituent may be present at a plurality of available substitution positions on its linking structure, and the substituent present at each of the plurality of available substitution positions may be of the same structure or of different structures.

In the compounds mentioned in this disclosure, adjacent substituents in the compounds cannot be linked to form a ring unless explicitly defined, for example, adjacent substituents can optionally be linked to form a ring. In the compounds mentioned in this disclosure, adjacent substituents can optionally be linked to form a ring, both in the case where adjacent substituents can be linked to form a ring and in the case where adjacent substituents are not linked to form a ring. Where adjacent substituents can optionally be joined to form a ring, the ring formed can be monocyclic or polycyclic (including spiro, bridged, fused, etc.), as well as alicyclic, heteroalicyclic, aromatic or heteroaromatic. In this expression, adjacent substituents may refer to substituents bonded to the same atom, substituents bonded to carbon atoms directly bonded to each other, or substituents bonded to further distant carbon atoms. Preferably, adjacent substituents refer to substituents bonded to the same carbon atom and substituents bonded to carbon atoms directly bonded to each other.

The expression that adjacent substituents can optionally be linked to form a ring is also intended 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:

The expression that adjacent substituents can optionally be 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:

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

furthermore, the expression 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 adjacent two 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:

The metal M is selected from metals with relative atomic mass of more than 40;

X ₁ -X ₈ is selected from CR, identically or differently at each occurrence _x ，CR _x1 C or NAnd X is ₁ -X ₈ At least one of them is selected from CR _x1 And said R _x1 Cyano or fluoro;

R’，R _x ，R _n ，R ₁ ，R ₂ and R is ₃ And is selected identically or differently on each occurrence 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 heteroaryl having 3 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 alkyl 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 having 2 to 20 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, substituted or unsubstituted alkylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkyl germanium having 3 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, carbonyl having 0 to 20 carbon atoms, cyano, sulfonyl, cyano, carbonyl, cyano, sulfonyl, cyano, or the like;

Herein, "adjacent substituents R', R _x ，R _n ，R ₁ ，R ₂ ，R ₃ Can optionally be linked to form a ring "is intended to mean wherein adjacent groups of substituents, e.g. between adjacent substituents R', adjacent substituents R _x Between adjacent substituents R _n Between adjacent substituents R ₁ Between adjacent substituents R ₂ Between adjacent substituents R ₃ Between adjacent substituents R ₁ And R is ₂ Between adjacent substituents R _n And R is ₃ Between which any one or more of these substituent groups can be linked to form a ring. It is obvious that none of these adjacent groups of substituents may be linked to form a ring.

According to one embodiment of the invention, wherein R _n And is selected identically or differently on each occurrence from the group consisting of: 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 having 2 to 20 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, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkyl having 3 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, substituted or unsubstituted germanium, carbonyl having 0 to 20 carbon atoms, sulfonyl, cyano, sulfonyl having 0 to 20 carbon atoms, sulfonyl having 3 to 20 carbon atoms, and the like.

According to one embodiment of the invention, wherein M is selected from the group consisting of Cu, ag, au, ru, rh, pd, os, ir and Pt.

According to one embodiment of the invention, wherein M is selected from Pt or Ir.

According to one embodiment of the invention, wherein M is selected from Ir.

According to one embodiment of the invention, wherein R _n Identical or different at each occurrenceAnd is selected from the group consisting of: substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, substituted or unsubstituted aralkyl groups having 7 to 30 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 alkylgermanium groups having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanium groups having 6 to 20 carbon atoms, and combinations thereof.

According to one embodiment of the invention, wherein G ₁ And G ₂ Selected from the group consisting of single bond, ring Cx, ring Cy, ring Cw and ring Cz, identically or differently for each occurrence, are selected from the group consisting of: an aromatic ring having 6-12 ring atoms, a substituted or unsubstituted heteroaromatic ring having 5-18 ring atoms, and combinations thereof.

According to one embodiment of the invention, wherein G ₁ And G ₂ Selected from single bonds, ring Cx, ring Cz are identically or differently selected for each occurrence from substituted or unsubstituted aromatic rings having 6 to 12 ring atoms; ring Cy, ring Cw is selected identically or differently on each occurrence from substituted or unsubstituted heteroaryl rings having 5 to 18 ring atoms.

According to one embodiment of the invention, the rings Cx, cz are, identically or differently, selected for each occurrence from a substituted or unsubstituted benzene ring or a substituted or unsubstituted naphthalene ring; ring Cy, ring Cw is, for each occurrence, the same or different selected from the group consisting of a substituted or unsubstituted pyridine ring, a substituted or unsubstituted imidazole ring, a substituted or unsubstituted pyrazole ring, a substituted or unsubstituted thiazole ring, a substituted or unsubstituted oxazole ring, a substituted or unsubstituted pyrimidine ring, a substituted or unsubstituted triazine ring, a substituted or unsubstituted pyrazine ring, a substituted or unsubstituted pyridine ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted pyrrole ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted carbazole ring, a substituted or unsubstituted azacarbazole ring, a substituted or unsubstituted dibenzofuran ring, a substituted or unsubstituted dibenzothiophene ring, a substituted or unsubstituted azadibenzofuran ring, a substituted or unsubstituted azafluorene ring.

According to one embodiment of the invention, L _a And is selected identically or differently on each occurrence from the group consisting of:

the ring Cx is identically or differently selected for each occurrence from a substituted or unsubstituted aromatic ring having from 6 to 12 ring atoms, a substituted or unsubstituted heteroaromatic ring having from 5 to 18 ring atoms, or a combination thereof;

R ₃ each occurrence, identically or differently, represents mono-, poly-or unsubstituted;

R _n each occurrence, identically or differently, represents mono-or poly-substitution;

R ₄ each occurrence of which is identical or different represents monosubstituted or polysubstituted, and R ₄ At least one of which is cyano or fluoro;

L _b a structure shown at each occurrence as being the same or different selected from any one of the group consisting of:

R ₁ ，R ₂ each occurrence, identically or differently, represents mono-substituted, poly-substituted, or unsubstituted;

R’，R ₁ -R ₆ each timeAnd are selected 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 heteroaryl having 3 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 alkyl 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 having 2 to 20 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, substituted or unsubstituted alkylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkyl germanium having 3 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, carbonyl having 0 to 20 carbon atoms, cyano, sulfonyl, cyano, carbonyl, cyano, sulfonyl, cyano, or the like;

R _n Each occurrence of which is identically or differently selected from the group consisting of R _n1 -R _n34 And (3) a group consisting of:

". Times. Represents R _n Is connected with the connecting position of the connecting rod;

adjacent substituents R', R _n ，R ₁ -R ₆ Can optionally be linked to form a ring.

Herein, "adjacent substituents R', R _n ，R ₁ -R ₆ Can optionally be linked to form a ring "is intended to mean wherein adjacent groups of substituents, e.g. between adjacent substituents R', adjacent substituents R _n Between adjacent substituents R ₁ Between adjacent substituents R ₂ Between adjacent substitutionsRadical R ₃ Between adjacent substituents R ₄ Between adjacent substituents R ₁ And R is ₂ Between adjacent substituents R _n And R is ₃ Between adjacent substituents R ₁ And R is ₅ Between adjacent substituents R ₁ And R is ₆ Between which any one or more of these substituent groups can be linked to form a ring. It is obvious that none of these adjacent groups of substituents may be linked to form a ring.

According to one embodiment of the invention, the metal complex Ir (L _a ) _m (Lb) _3-m Has a structure represented by formula 3A or formula 3B:

ring Cx is selected identically or differently for each occurrence from the group consisting of: an aromatic ring having 6 to 12 ring atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, and combinations thereof;

m is selected from 1 or 2; when m is selected from 1, two L _b The same or different; when m is selected from 2, two L _a The same or different;

X ₃ -X ₈ is selected from CR, identically or differently at each occurrence _x ，CR _x1 Or N, and X ₃ -X ₈ At least one of them is selected from CR _x1 And said R _x1 Cyano or fluoro;

X ₉ -X ₁₂ is selected from CR, identically or differently at each occurrence _x Or N;

R _n is selected identically or differently on each occurrence from the group consisting of R _n1 -R _n34 A group of;

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R’，R _x ，R _1-1 -R _1-4 and is selected identically or differently on each occurrence 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 heteroaryl having 3 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 alkyl 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 having 2 to 20 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, substituted or unsubstituted alkylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkyl germanium having 3 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, carbonyl having 0 to 20 carbon atoms, cyano, sulfonyl, cyano, carbonyl, cyano, sulfonyl, cyano, or the like;

R _2-1 -R _2-4 And is selected identically or differently on each occurrence 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 alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 3 to 20 carbon atomsA substituted or unsubstituted alkyl germanium group having 3 to 20 carbon atoms, a substituted or unsubstituted amino 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 substituents R', R _x Can optionally be linked to form a ring;

adjacent substituents R _1-1 -R _1-4 ，R _2-1 -R _2-4 Can optionally be linked to form a ring.

Herein, "adjacent substituents R', R _x Can optionally be linked to form a ring "is intended to mean wherein adjacent groups of substituents, e.g. between adjacent substituents R', adjacent substituents R _x Between which any one or more of these substituent groups can be linked to form a ring. It is obvious that none of these adjacent groups of substituents may be linked to form a ring.

Herein, "adjacent substituent R _1-1 -R _1-4 ，R _2-1 -R _2-4 Can optionally be linked to form a ring "is intended to mean wherein adjacent groups of substituents, e.g. substituents R _1-1 -R _1-4 Between any two of them, substituent R _2-1 -R _2-4 Between any two of them, substituent R _1-4 And R is _2-1 Any one or more of these substituent groups may be linked to form a ring. Obviously, these substituents may not all be linked to form a ring.

According to one embodiment of the invention, ring Cx is selected identically or differently for each occurrence from a substituted or unsubstituted aromatic ring of 6 to 12 ring atoms.

According to one embodiment of the invention, wherein ring Cx is selected identically or differently for each occurrence from substituted or unsubstituted benzene rings.

According to one embodiment of the invention, the metal complex Ir (L _a ) _m (L _b ) _3-m Has a structure represented by formula 3C:

X ₃ -X ₈ is selected from CR, identically or differently at each occurrence _x ，CR _x1 Or N, and X ₃ -X ₈ At least one of them is selected from CR _x1 ；

And said R is _x1 Cyano or fluoro;

Y ₁ -Y ₅ is selected from CR, identically or differently at each occurrence _n ，CR _y Or N, and Y ₂ -Y ₄ At least one of them is selected from R _n ；

R’，R _x ，R _y ，R _1-1 -R _1-4 ，R _2-1 -R _2-4 and is selected identically or differently on each occurrence 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 unsubstitutedAn unsubstituted aralkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted 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 silyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted alkylgermanium group having 3 to 20 carbon atoms, a substituted or unsubstituted arylgermanium group having 6 to 20 carbon atoms, a substituted or unsubstituted amino 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 hydroxy group, a mercapto group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

Adjacent substituents R', R _y ，R _x Can optionally be linked to form a ring;

Herein, "adjacent substituents R', R _y ，R _x Can optionally be linked to form a ring "is intended to mean wherein adjacent groups of substituents, e.g. between adjacent substituents R', adjacent substituents R _x Between adjacent substituents R _y Between which any one or more of these substituent groups can be linked to form a ring. It is obvious that none of these adjacent groups of substituents may be linked to form a ring.

According to one embodiment of the invention, Y ₁ -Y ₅ Is selected identically or differently on each occurrence from C, CR _y Or N, and Y ₃ Selected from R _n 。

According to one embodiment of the invention, wherein R _x And is selected identically or differently on each occurrence 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 6 to 3 carbon atomsAryl groups of 0 carbon atoms, substituted or unsubstituted heteroaryl groups of 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl groups of 3 to 20 carbon atoms, cyano groups, and combinations thereof.

According to one embodiment of the invention, wherein X ₃ -X ₈ The same or different at each occurrence is selected from CR _x Or CR (CR) _x1 And X is ₃ -X ₈ At least one of them is selected from CR _x1 The R is _x1 Cyano or fluoro; and/or X ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x 。

According to one embodiment of the invention, wherein X ₃ -X ₈ The same or different at each occurrence is selected from CR _x Or CR (CR) _x1 And X is ₃ -X ₈ At least one of them is selected from CR _x1 The R is _x1 Cyano or fluoro; and/or X ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x ；

The R is _x And is selected identically or differently on each occurrence from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring 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 silyl groups having 3 to 20 carbon atoms, cyano groups, and combinations thereof.

According to one embodiment of the invention, wherein X ₅ -X ₈ The same or different at each occurrence is selected from CR _x Or CR (CR) _x1 And X is ₅ -X ₈ At least one of them is selected from CR _x1 The R is _x1 Cyano or fluoro;

the R is _x 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 aryl having 3 to 20 carbon atoms Alkylsilyl, substituted or unsubstituted alkylgermanium groups having 3 to 20 carbon atoms, cyano groups, and combinations thereof.

According to one embodiment of the invention, wherein X ₃ -X ₈ At least one of which is N, and/or X ₉ -X ₁₂ At least one of which is N.

According to one embodiment of the invention, wherein X is selected from O or S.

According to one embodiment of the invention, wherein X is selected from O.

According to one embodiment of the invention, wherein the ring Cx is selected identically or differently for each occurrence from the group consisting of:

wherein "" means and includes X ₉ -X ₁₂ Is a ring Cy of the above-mentioned material.

According to one embodiment of the invention, the hydrogen in rings Cx-1 to Cx-51 can be partially or completely replaced with deuterium.

According to one embodiment of the invention, wherein X ₇ Or X ₈ At least one of them is selected from CR _x1 And said R _x1 Is cyano or fluoro.

According to one embodiment of the invention, wherein X ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x And substituents R ortho to the ring Cx _x Is hydrogen, and/or is attached to X on ring Cx ₉ -X ₁₂ The substituent ortho to the connection is hydrogen or deuterium.

Herein "X ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x Substituent R ortho to ring Cx _x Is hydrogen "is intended to mean X ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x Both substituents ortho to the ring Cx are hydrogen, e.g., X in formula 3A ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x X is ortho to ring Cx ₉ And X ₁₁ The substituents on both are hydrogen, X in formula 3B ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x X is ortho to ring Cx ₁₀ And X ₁₂ The substituents on the ring are all hydrogen; "ring Cx upper and X ₉ -X ₁₂ The substituents ortho to the connection being hydrogen or deuterium "is intended to mean the ring Cx is attached to X ₉ -X ₁₂ The two substituents attached in the left and right ortho positions are hydrogen or deuterium, for example, in formula 3B, when Cx is selected from the benzene ring, the metal complex has the structureAnd X is ₉ -X ₁₂ Y in the ortho-position of the left and right of the connection ₁ And Y ₅ The upper substituent is selected from H or D, and when Cx is selected from condensed rings, the metal complex has the following structureAnd X is ₉ -X ₁₂ Y in the ortho-position of the connection ₁ The substituents on the ring are selected from H or D.

According to one embodiment of the invention, wherein X ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x And substituents R ortho to the ring Cx _x Is hydrogen, and X is attached to ring Cx ₉ -X ₁₂ The substituent ortho to the connection is hydrogen or deuterium.

According to one embodiment of the invention, wherein X ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x And substituents R ortho to the ring Cx _x Is hydrogen, or X on ring Cx ₉ -X ₁₂ The substituent ortho to the connection is hydrogen or deuterium.

According to one embodiment of the invention, wherein R _1-1 -R _1-4 ，R _2-1 -R _2-4 At least one or at least two selected from the group consisting of substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, or combinations thereof, and all of said R groups _1-1 -R _1-4 And/or R _2-1 -R _2-4 The sum of the number of carbon atoms of (2) is at least 4.

According to one embodiment of the invention, wherein R _1-1 -R _1-4 At least one or at least two selected from the group consisting of substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, or combinations thereof, and all of said R groups _1-1 -R _1-4 Is at least 4; and/or R _2-1 -R _2-4 At least one or at least two selected from the group consisting of substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, or combinations thereof, and all of said R groups _2-1 -R _2-4 The sum of the number of carbon atoms of (2) is at least 4.

According to one embodiment of the invention, wherein R _1-2 ，R _1-3 ，R _2-2 ，R _2-3 At least one or at least two or at least three or all of which are selected from the group consisting of: substituted or unsubstituted alkyl groups having from 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having from 3 to 20 ring carbon atoms, and combinations thereof.

According to one embodiment of the invention, R _1-2 ，R _1-3 ，R _2-2 ，R _2-3 At least one or at least two or at least three or all of which are selected from the group consisting of: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, cyclopentyl, cyclohexyl, neopentyl, t-pentyl, and combinations thereof.

According to one embodiment of the invention, the hydrogen in the methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopentyl, cyclohexyl, neopentyl, tert-pentyl groups can be partially or fully deuterated.

According to one embodiment of the invention, wherein R _1-1 -R _1-4 ，R _2-1 -R _2-4 Selected from the group consisting of: hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, substituted or unsubstituted alkylsilyl groups having 3 to 20 carbon atoms, substituted or unsubstituted alkylgermanium groups having 3 to 20 carbon atoms, and combinations thereof.

According to one embodiment of the invention, wherein the ligand L _a Is selected identically or differently on each occurrence from the group consisting of L _a1 To L _a3456 A group consisting of said L _a1 To L _a3456 Is specified in claim 15.

According to one embodiment of the invention, wherein the ligand L _b Is selected identically or differently on each occurrence from the group consisting of L _b1 To L _b156 A group consisting of said L _b1 To L _b156 Is specified in claim 16.

According to one embodiment of the invention, wherein the metal complex has IrL _a (L _b ) ₂ L is of the structure of _a Selected from the group consisting of L _a1 -L _a3456 Group of L _b Is selected identically or differently on each occurrence from the group consisting of L _b1 -L _b156 Either or both of the groups.

According to one embodiment of the present invention, wherein the metal complex is selected from the group consisting of metal complex 1 to metal complex 4764, the specific structure of the metal complex 1 to metal complex 4764 is as in claim 17.

According to an embodiment of the present invention, there is also disclosed an organic electroluminescent device including: an anode, a cathode, and an organic layer disposed between the anode and the cathode, the organic layer comprising the metal complex of any of the foregoing embodiments.

According to one embodiment of the invention, the organic layer is a light emitting layer.

According to one embodiment of the present invention, the light-emitting layer includes a first host compound.

According to one embodiment of the present invention, the light-emitting layer includes a first host compound and a second host compound.

According to one embodiment of the invention, wherein the first host compound and/or the second host compound comprises at least one chemical group selected from the group consisting of: benzene, pyridine, pyrimidine, triazine, carbazole, azacarbazole, indolocarbazole, dibenzothiophene, azadibenzothiophene, dibenzofuran, azadibenzofuran, dibenzoselenophene, triphenylene, azatriphenylene, fluorene, silafluorene, naphthalene, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene, azaphenanthrene, and combinations thereof.

According to another embodiment of the present invention, wherein the first host compound has a structure represented by formula 4:

E ₁ -E ₆ is selected identically or differently on each occurrence from C, CR _e Or N, and E ₁ -E ₆ At least two of them are N, E ₁ -E ₆ At least one of which is C and is linked to formula A;

q is the same or different at each occurrence selected from the group consisting of O, S, se, N, NR ", CR" R ", siR" R ", geR" R "and R" C=CR "; when two R's are present at the same time, the two R's may be the same or different;

p is 0 or 1; r is 0 or 1;

when Q is selected from N, p is 0, 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 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;

Q ₁ -Q ₈ is selected identically or differently on each occurrence from C, CR _q Or N;

R _e r' and R _q And is selected, identically or differently, on each occurrence, 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 heteroaryl having 3 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 alkyl 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 having 2 to 20 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, substituted or unsubstituted alkylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkyl germanium having 3 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, carbonyl having 0 to 20 carbon atoms, cyano, sulfonyl, cyano, carbonyl, cyano, sulfonyl, cyano, or the like;

". Times." represents the connection position of formula A with formula 4;

adjacent substituents R _e ，R”，R _q Can optionally be linked into a ring.

Herein, "adjacent substituent R _e ，R”，R _q Can optionally be linked to form a ring ", is intended to mean groups of adjacent substituents therein, e.g., adjacent substituents R _e Between adjacent substituents R', and _q between adjacent substituents R _Q And R is _q In between, any one or more of these substituent groups may be linked to form a ring. Obviously, these substituents may not all be linked to form a ring.

According to another embodiment of the invention, wherein E ₁ -E ₆ The same or different at each occurrenceIs selected from C, CR _e Or N, and E ₁ -E ₆ Wherein three are N, E ₁ -E ₆ At least one is CR _e And said R _e And is selected identically or differently on each occurrence from the group consisting of: substituted or unsubstituted aryl groups having from 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having from 3 to 30 carbon atoms, and combinations thereof;

and/or Q is selected identically or differently on each occurrence from O, S, N or NR';

and/or Q ₁ -Q ₈ At least one or at least two of them are selected from CR _q And said R _q Selected from substituted or unsubstituted aryl groups having from 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having from 5 to 30 carbon atoms, or combinations thereof;

And/or L is, identically or differently, 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.

According to another embodiment of the invention, wherein the first host compound is selected from the group consisting of:

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according to another embodiment of the present invention, wherein the second host compound has a structure represented by formula 5:

L _x each occurrence is identically or differently selected 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;

v is selected, identically or differently, for each occurrence, from C, CR _v Or N, and at least one of V is C, and is with L _x Connecting;

u is selected, identically or differently, from C, CR for each occurrence _u Or N, and at least one of U is C and is with L _x Connecting;

R _v and R is _u And is selected, identically or differently, on each occurrence, 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 having 2 to 20 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, substituted or unsubstituted alkylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted arylgermanium having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanium having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

Ar ₆ the same or different at each occurrence is selected from substituted or unsubstituted aryl groups having from 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having from 3 to 30 carbon atoms, or combinations thereof;

adjacent substituents R _v And R is _u Can optionally be linked to form a ring.

Herein, "adjacent substituent R _v And R is _u Can optionally be linked to form a ring ", is intended to mean groups of adjacent substituents therein, e.g., adjacent substituents R _v Between adjacent substituents R _u Between adjacent substituents R _v And R is _u In between, any one or more of these substituent groups may be linked to form a ring. Obviously, these substituents may not all be linked to form a ring.

According to one embodiment of the present invention, wherein the second host compound has a structure represented by one of formulas 5-a to 5-j:

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R _v and R is _u And is selected, identically or differently, on each occurrence, 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 heteroaryl having 3 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 alkyl 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 having 2 to 20 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, substituted or unsubstituted alkylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkyl germanium having 3 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, carbonyl having 0 to 20 carbon atoms, cyano, sulfonyl, cyano, carbonyl, cyano, sulfonyl, cyano, or the like;

Ar ₆ Each occurrence of which is identically or differently selected from substituted or unsubstitutedAryl groups having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3 to 30 carbon atoms, or combinations thereof;

adjacent substituents R _v And R is _u Can optionally be linked to form a ring.

According to one embodiment of the invention, wherein the second host compound is selected from the group consisting of:

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according to one embodiment of the present invention, 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% -30% of the total weight of the light emitting layer.

According to one embodiment of the invention, the metal complex is doped in 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.

According to one embodiment of the present invention, there is also disclosed a compound composition comprising the metal complex of any of the preceding embodiments.

Combined with other materials

The materials described herein for specific layers in an organic light emitting device may be used in combination with various other materials present in the device. Combinations of these materials are described in detail in U.S. patent application 2016/0359122A1, paragraphs 0132-0161, the entire contents of which are incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that may be used in combination with the compounds disclosed herein, and one skilled in the art can readily review the literature to identify other materials that may be used in combination.

Materials described herein as useful for specific layers in an organic light emitting device may be used in combination with a variety of other materials present in the device. For example, the compounds disclosed herein may be used in combination with a variety of light-emitting dopants, hosts, transport layers, barrier layers, implant layers, electrodes, and other layers that may be present. Combinations of these materials are described in detail in U.S. patent application Ser. No. 2015/0349273A1, paragraphs 0080-0101, the entire contents of which are incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that may be used in combination with the compounds disclosed herein, and one skilled in the art can readily review the literature to identify other materials that may be used in combination.

In the examples of material synthesis, all reactions were carried out under nitrogen protection, unless otherwise indicated. All reaction solvents were anhydrous and used as received from commercial sources. The synthetic products were subjected to structural confirmation and characterization testing using one or more equipment conventional in the art (including, but not limited to, bruker's nuclear magnetic resonance apparatus, shimadzu's liquid chromatograph, liquid chromatograph-mass spectrometer, gas chromatograph-mass spectrometer, differential scanning calorimeter, shanghai's optical technique fluorescence spectrophotometer, wuhan Koste's electrochemical workstation, anhui Bei Yi g sublimator, etc.), in a manner well known to those skilled in the art. In an embodiment of the device, the device characteristics are also tested using equipment conventional in the art (including, but not limited to, a vapor deposition machine manufactured by Angstrom Engineering, an optical test system manufactured by Frieda, st. John's, an ellipsometer manufactured by Beijing, etc.), in a manner well known to those skilled in the art. Since those skilled in the art are aware of the relevant contents of the device usage and the testing method, and can obtain the intrinsic data of the sample certainly and uninfluenced, the relevant contents are not further described in this patent.

Material synthesis examples:

the preparation method of the compound of the present invention is not limited, and is typically, but not limited to, exemplified by the following compounds, the synthetic routes and preparation methods thereof are as follows:

synthesis example 1: synthesis of Metal Complex 4169

Step 1:

a500 mL round bottom flask was dried and charged with 5-tert-butyl-2-phenylpyridine (13.2 g,62.9 mmol), iridium trichloride trihydrate (5.5 g,15.7 mmol), 300mL of 2-ethoxyethanol, 100mL of water, nitrogen sparge three times and nitrogen blanket, and heated to 130℃under stirring for 24h. After cooling, filtration, washing with methanol and n-hexane three times, respectively, and suction drying gave 9.7g of intermediate 1 (97% yield).

Step 2:

into a dry 500mL round bottom flask, intermediate 1 (9.7 g,7.7 mmol), anhydrous dichloromethane 250mL, methanol 10mL, silver triflate (4.3 g,16.7 mmol), nitrogen replaced three times and nitrogen protected, were added sequentially and stirred overnight at room temperature. The celite was filtered and dichloromethane washed 2 times and the lower organic phase was collected and concentrated under reduced pressure to yield 13.2g of yellow solid intermediate 2 (93% yield).

Step 3:

to a dry 250mL round bottom flask was added in sequence intermediate 3 (1.3 g,3.8 mmol), intermediate 2 (2.2 g,2.7 mmol), ethanol 100mL, nitrogen sparge three times and nitrogen blanket, and the reaction was heated at 100deg.C for 24h. After the reaction cooled, the celite was filtered. Methanol, n-hexane were washed 2 times respectively, and the yellow solid above celite was dissolved with methylene chloride, and the organic phase was collected, concentrated under reduced pressure, and purified by column chromatography to give the yellow solid product metal complex 4169 (1.0 g,39.0% yield). The product was identified as the target product and had a molecular weight of 956.3.

Synthesis example 2: synthesis of Metal Complex 4125

Step 1:

to a dry 250mL round bottom flask was added in sequence intermediate 4 (1.9 g,4.5 mmol), intermediate 2 (2.9 g,3.5 mmol), 2-ethoxyethanol and N, N-dimethylformamide each 35mL, nitrogen replaced three times and nitrogen blanket, and the reaction was heated at 96℃for 72h. After the reaction cooled, the celite was filtered. Methanol, n-hexane were washed 2 times respectively, and the yellow solid above celite was dissolved with methylene chloride, and the organic phase was collected, concentrated under reduced pressure, and purified by column chromatography to give the yellow solid product metal complex 4125 (1.0 g,27.8% yield). The product was identified as the target product and had a molecular weight of 1027.3.

Synthesis example 3: synthesis of Metal Complex 4579

Step 1:

a500 mL round bottom flask was dried and charged with 5-tert-butyl-2- (3-tert-butylphenyl) -pyridine (4.7 g,17.6 mmol), iridium trichloride trihydrate (1.5 g,4.2 mmol), 120mL of 2-ethoxyethanol, 40mL of water, nitrogen sparge three times and nitrogen blanket, and heated and stirred at 130℃for 24h. After cooling, the mixture was filtered, washed three times with methanol and n-hexane, and dried by suction to give 3.0g of intermediate 5 (96% yield).

Step 2:

into a dry 250mL round bottom flask, intermediate 5 (3.0 g,2.0 mmol), anhydrous dichloromethane 100mL, methanol 10mL, silver triflate (1.1 g,4.3 mmol), nitrogen replaced three times and nitrogen protected, were added sequentially and stirred overnight at room temperature. The celite was filtered and dichloromethane washed 2 times, the lower organic phase was collected and concentrated under reduced pressure to give 3.7g of yellow solid intermediate 6 which was used in the next reaction without further purification.

Step 3:

a dry 250mL round bottom flask was charged with intermediate 6 (2.7 g,2.9 mmol), intermediate 7 (1.5 g,4.3 mmol), 2-ethoxyethanol (50 mL) and DMF (50 mL), N ₂ Under the protection, the reaction is heated at 100 ℃ for 100h. After the reaction cooled, the celite was filtered. Methanol, n-hexane were washed 2 times respectively, and the yellow solid above celite was dissolved with methylene chloride, and the organic phase was collected, concentrated under reduced pressure, and purified by column chromatography to give yellow solid metal complex 4579 (1.8 g,57.6% yield). The product structure is determined as the target product, and the molecular weight is 1076.5

Synthesis example 4: synthesis of metal Complex 2136

Step 1:

a dry 250mL round bottom flask was charged with intermediate 6 (1.9 g,2.0 mmol), intermediate 8 (0.9 g,2.2 mmol), 2-ethoxyethanol (30 mL), and N, N-dimethylformamide (30 mL), in sequence ₂ Under the protection, the reaction is heated at 100 ℃ for 120 hours. After the reaction cooled, the celite was filtered. Methanol, n-hexane were washed 2 times respectively, and the yellow solid above celite was dissolved with methylene chloride, and the organic phase was collected, concentrated under reduced pressure, and purified by column chromatography to give yellow solid metal complex 2136 (1.0 g,44.2% yield). The product structure was determined to be the target product and the molecular weight was 1131.5.

Those skilled in the art will recognize that the above preparation method is only an illustrative example, and that those skilled in the art can modify it to obtain other compound structures of the present invention.

Device example 1

First, a glass substrate having an 80nm thick Indium Tin Oxide (ITO) anode was cleaned, and then treated with oxygen plasma and UV ozone. After the treatment, the substrate was baked in a glove box to remove moisture. The substrate is then mounted on a substrate support and loaded into a vacuum chamber. The organic layer specified below was at a vacuum level of about 10 ^-8 In the case of the support, vapor deposition was sequentially performed on the ITO anode by thermal vacuum vapor deposition at a rate of 0.2 to 2 Angstrom/sec. The compound HI was used as a Hole Injection Layer (HIL) with a thickness of The compound HT is used as a Hole Transport Layer (HTL) with a thickness of +.>Compound PH-23 is used as an Electron Blocking Layer (EBL) with a thickness ofThe inventive metal complexes 4169 were then co-deposited (weight ratio 6:47:47) as light-emitting layer (EML) doped in compound PH-23 and compound H-91, thickness +.>On EML, compound HB acts as a Hole Blocking Layer (HBL) with a thickness ofOn the HBL, a compound ET and 8-hydroxyquinoline-lithium (Liq) were co-deposited (weight ratio 40:60) as an Electron Transport Layer (ETL) with a thickness of +. >Finally, 8-hydroxyquinoline-lithium (Liq) with a thickness of 1nm was evaporated as an electron injection layer, and 120nm of aluminum was evaporated as a cathode. The device is then transferred back to the gloveA box and encapsulated with a glass cover and a moisture absorbent to complete the device.

Device example 2

The embodiment of device example 2 is the same as device example 1 except that the inventive metal complex 4125 is substituted for the inventive metal complex 4169 in the light-emitting layer.

Device comparative example 1

The embodiment of device comparative example 1 is the same as device example 1 except that the compound GD1 is used in the light-emitting layer (EML) instead of the metal complex 4169 of the present invention.

Device example 3

The embodiment of device example 3 is the same as device example 2 except that the metal complex of the present invention 4125 is replaced with a metal complex 4579 in the light emitting layer (EML), and compound HT is used in HIL: compound pd=97:3 instead of compound HI.

Device example 4

The embodiment of device example 4 is the same as device example 3 except that the metal complex of the present invention 4579 is replaced with the metal complex of the present invention 2136 in the light-emitting layer.

Device comparative example 2

The embodiment of device comparative example 2 was the same as device example 3 except that the compound GD1 was used in the light-emitting layer (EML) instead of the metal complex 4579 of the present invention.

The detailed device layer structure and thickness are shown in the following table. Wherein more than one layer of the material used is doped with different compounds in the weight proportions described.

Table 1 partial device structures of examples 1 to 4 and comparative examples 1 to 2

The material structure used in the device is as follows:

the IVL characteristics of the device were measured. At 1000cd/m ² The CIE data of the device, the maximum emission wavelength lambda, are measured _max Voltage (V), current Efficiency (CE), power Efficiency (PE), external Quantum Efficiency (EQE). These data are recorded and shown in table 2.

Table 2 device structure device data for examples 1 to 4 and comparative examples 1 to 2

Discussion:

table 2 shows the device performance of the inventive and comparative compounds. From table 2, it can be seen that the maximum emission wavelengths of the examples and the comparative examples are both in the yellow light range.

Compared with comparative example 1, the device of example 1 had a drive voltage drop of 0.32v, an eqe increase of 5%, a PE increase of 13.4%, and a CE equivalent. Example 2 further at L _a R in ligand _n For phenyl substitution, it is difficult and expensive that all aspects of voltage, current efficiency, power efficiency, external quantum efficiency of example 2 remain substantially at comparable or better levels than example 1, on the basis that example 1 has reached a very high level. And example 2 has a further reduction in driving voltage than example 1, CE, PE being equivalent or higher; unexpectedly, the EQE of example 2 reached 25.6%, a further improvement of 10.8% on the basis of example 1. Has higher device efficiency, thereby obtaining a device with better performance.

Compared with comparative example 2, the device of example 3 had a drive voltage reduced by 0.6V, an EQE increased by 18.1%, a CE increased by 11.2%, and a PE increased by 36.6%. Example 4 further at L _a R in ligand _n It is difficult and expensive to keep all aspects of the voltage, current efficiency, power efficiency, external quantum efficiency of example 4 at substantially higher or better levels than example 3, on the basis that example 3 has reached a very high level. In addition, the driving voltage of the embodiment 4 is kept equivalent to that of the embodiment 3, and the CE and the PE are further improved by 20.3 percent and 18.7 percent respectively; at the same time, it is also unexpected that the EQE of example 4 reaches 28.5%, which is further improved by 12.2% on the basis of example 3. Has higher device efficiency, thereby obtaining a device with better performance.

The above indicates that the inclusion ring Cx provided by the present application has a specific R _n Substituted L _a Ligands and L having specific substituents _b The metal complex of the ligand can obviously improve the performance of the device, and finally, the comprehensive performance of the device is greatly improved.

In summary, the application includes a specific R on ring Cx _n Substituted L _a Ligands and L having specific substituents _b The metal complex of the ligand can obtain excellent device performance when applied to an organic electroluminescent device, especially CE of the device, PE of the device and EQE of the device are improved remarkably, and the comprehensive performance of the device can be improved remarkably. Has wide application prospect in commercial yellow light and white light luminescent devices.

The advantages observed for the compounds of the present invention are completely unexpected. Even for a person skilled in the art it is not possible to predict this.

It should be understood that the various embodiments described herein are by way of example only and are not intended to limit the scope of the invention. Thus, as will be apparent to those skilled in the art, the claimed invention may include variations of the specific and preferred embodiments described herein. Many of the materials and structures described herein may be substituted with other materials and structures without departing from the spirit of the invention. It is to be understood that the various theories as to why the present invention works are not intended to be limiting.

Claims

1. A metal complex having M (L _a ) _m( L _b ) _n Is represented by the general formula (I),

the metal M is selected from metals with relative atomic mass of more than 40;

x is selected from the group consisting of O, S, se, NR ', siR ' R ' and GeR ' R '; when two R's are present at the same time, the two R's are the same or different; ring Cx, ring Cy, ring Cw, ring Cz are identically or differently selected for each occurrence from a substituted or unsubstituted aromatic ring having from 6 to 24 ring atoms, a substituted or unsubstituted heteroaromatic ring having from 5 to 24 ring atoms, or a combination thereof;

R _n ，R ₁ ，R ₂ and R is ₃ Each occurrence of which is the same or different represents mono-substituted, poly-substituted or non-substitutedSubstitution;

2. The metal complex of claim 1, wherein the metal M is selected from the group consisting of Cu, ag, au, ru, rh, pd, os, ir and Pt; preferably, M is selected from Pt or Ir;

R _n and is selected identically or differently on each occurrence from the group consisting of: 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 aryl havingAralkyl 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 having 2 to 20 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 silyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermanium group having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanium group having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxylic acid, ester, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

Preferably, R _n And is selected identically or differently on each occurrence from the group consisting of: substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, substituted or unsubstituted aralkyl groups having 7 to 30 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 alkylgermanium groups having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanium groups having 6 to 20 carbon atoms, and combinations thereof.

3. The metal complex as claimed in claim 1 or 2, wherein G ₁ And G ₂ Selected from the group consisting of single bond, ring Cx, ring Cy, ring Cw and ring Cz, identically or differently for each occurrence, are selected from the group consisting of: an aromatic ring having 6 to 12 ring atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, and combinations thereof;

preferably, ring Cx, ring Cz are, identically or differently, selected for each occurrence from substituted or unsubstituted aromatic rings having 6 to 12 ring atoms; ring Cy, ring Cw is selected identically or differently on each occurrence from substituted or unsubstituted heteroaryl rings having 5 to 18 ring atoms;

More preferably, ring Cx, ring Cz are identically or differently selected for each occurrence from a substituted or unsubstituted benzene ring, or a substituted or unsubstituted naphthalene ring; ring Cy, ring Cw is, for each occurrence, the same or different selected from the group consisting of a substituted or unsubstituted pyridine ring, a substituted or unsubstituted imidazole ring, a substituted or unsubstituted pyrazole ring, a substituted or unsubstituted thiazole ring, a substituted or unsubstituted oxazole ring, a substituted or unsubstituted pyrimidine ring, a substituted or unsubstituted triazine ring, a substituted or unsubstituted pyrazine ring, a substituted or unsubstituted pyridine ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted pyrrole ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted carbazole ring, a substituted or unsubstituted azacarbazole ring, a substituted or unsubstituted dibenzofuran ring, a substituted or unsubstituted dibenzothiophene ring, a substituted or unsubstituted azadibenzofuran ring, a substituted or unsubstituted azafluorene ring.

4. The metal complex as defined in claim 1 or 2, L _a And is selected identically or differently on each occurrence from the group consisting of:

R ₃ each occurrence ofAnd represents identically or differently mono-, poly-or unsubstituted;

R’，R ₁ -R ₆ and is selected identically or differently on each occurrence 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 having 2 to 20 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, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkylgermanium having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanium having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxy, mercapto, sulfinyl, sulfonyl A phosphine group, and combinations thereof;

R _n is selected identically or differently on each occurrence from the group consisting of R _n1 -R _n34 And (3) a group consisting of:

5. The metal complex according to claim 2, wherein the metal complex Ir (L _a ) _m (L _b ) _3-m And has a structure represented by formula 3A or formula 3B:

ring Cx is selected identically or differently for each occurrence from the group consisting of: an aromatic ring having 6 to 12 ring atoms, a substituted or unsubstituted heteroaromatic ring having 5 to 18 ring atoms, and combinations thereof; preferably, the ring Cx is selected identically or differently on each occurrence from substituted or unsubstituted aromatic rings having 6 to 12 ring atoms; more preferably, ring Cx is selected identically or differently for each occurrence from substituted or unsubstituted benzene rings;

X ₃ -X ₈ is selected from CR, identically or differently at each occurrence _x ，CR _x1 The method comprises the steps of carrying out a first treatment on the surface of the And X is ₃ -X ₈ At least one of them is selected from CR _x1 And said R _x1 Is cyano groupOr fluorine;

R’，R _x ，R _1-1 -R _1-4 ，R _2-1 -R _2-4 and is selected identically or differently on each occurrence 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 heteroaryl having 3 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 alkyl 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 having 2 to 20 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, substituted or unsubstituted alkylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted alkyl germanium having 3 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 20 carbon atoms, carbonyl having 0 to 20 carbon atoms, cyano, sulfonyl, cyano, carbonyl, cyano, sulfonyl, cyano, or the like;

R _2-1 -R _2-4 And is selected identically or differently on each occurrence 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 alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted alkynyl having 2 to 20 carbon atoms, substituted or unsubstituted silyl having 3 to 20 carbon atoms, substituted or unsubstituted alkylgermanium having 3 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphino, and combinations thereof;

adjacent substituents R', R _x Can optionally be linked to form a ring;

6. The metal complex as claimed in claim 5, wherein X ₃ -X ₈ The same or different at each occurrence is selected from CR _x Or CR (CR) _x1 And X is ₃ -X ₈ At least one of them is selected from CR _x1 The method comprises the steps of carrying out a first treatment on the surface of the And/or X ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x ；

Preferably, R _x And is selected identically or differently on each occurrence from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring 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 silyl groups having 3 to 20 carbon atoms, cyano groups, and combinations thereof;

more preferably, wherein X ₅ -X ₈ Each time go outAt the present time, identically or differently selected from CR _x Or CR (CR) _x1 And X is ₅ -X ₈ At least one of them is selected from CR _x1 The R is _x Selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring 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 alkylgermanium groups having 3 to 20 carbon atoms, cyano groups, and combinations thereof.

7. The metal complex according to claim 5, wherein X ₃ -X ₈ At least one of which is N, and/or X ₉ -X ₁₂ At least one of which is N.

8. The metal complex of claim 2, wherein X is selected from O or S, preferably X is selected from O.

9. The metal complex of claim 2 or 5, wherein the ring Cx is identically or differently selected from the group consisting of:

optionally, hydrogen in the above groups can be partially or fully substituted with deuterium; wherein "" means and includes X ₉ -X ₁₂ Is a ring Cy of the above-mentioned material.

10. The metal complex as claimed in claim 1, wherein X ₇ And/or X ₈ Selected from CR _x1 And said R _x1 Is cyano groupOr fluorine.

11. The metal complex according to claim 5, wherein X ₉ -X ₁₂ The same or different at each occurrence is selected from CR _x And substituents R ortho to the ring Cx _x Is hydrogen, and/or is attached to X on ring Cx ₉ -X ₁₂ The substituent ortho to the connection is hydrogen or deuterium.

12. The metal complex according to claim 5, wherein R _1-1 -R _1-4 ，R _2-1 -R _2-4 At least one or at least two selected from the group consisting of substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, or combinations thereof, and all of said R groups _1-1 -R _1-4 And/or R _2-1 -R _2-4 Is at least 4;

preferably, R _1-1 -R _1-4 At least one or at least two selected from the group consisting of substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, or combinations thereof, and all of said R groups _1-1 -R _1-4 Is at least 4; and/or R _2-1 -R _2-4 At least one or at least two selected from the group consisting of substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, or combinations thereof, and all of said R groups _2-1 -R _2-4 The sum of the number of carbon atoms of (2) is at least 4.

13. The metal complex according to claim 5, wherein R _1-2 ，R _1-3 ，R _2-2 ，R _2-3 At least one or at least two or at least three or all of which are selected from the group consisting of: substituted or unsubstituted alkyl groups having from 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having from 3 to 20 ring carbon atoms, and combinations thereof;

preferably, R _1-2 ，R _1-3 ，R _2-2 ，R _2-3 At least one or at least two orAt least three or all are selected from the group consisting of: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, cyclopentyl, cyclohexyl, neopentyl, t-pentyl, and combinations thereof; optionally, hydrogen in the above groups can be partially or fully deuterated.

14. The metal complex according to claim 5, wherein R _1-1 -R _1-4 ，R _2-1 -R _2-4 Selected from the group consisting of: hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 20 ring carbon atoms, substituted or unsubstituted alkylsilyl groups having 3 to 20 carbon atoms, substituted or unsubstituted alkylgermanium groups having 3 to 20 carbon atoms, and combinations thereof.

15. The metal complex of claim 9, wherein L _a Is selected identically or differently on each occurrence from the group consisting of L _a1 To L _a3456 A group of which is composed of,

wherein the L is _a1 To L _a1728 The structure is as follows:

wherein R is _x7 -R _x8 、R _x10 、Cx、R _n Respectively correspond to an atom or group selected from the following table:

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the L is _a1729 To L _a3456 The structure is as follows:

wherein R is _x7 -R _x8 、R _x11 、Cx、R _n Respectively correspond to an atom or group selected from the following table:

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16. the metal complex of claim 15, wherein L _b And is selected identically or differently on each occurrence from the group consisting of:

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17. the metal complex as claimed in claim 16, wherein the metal complex has IrL _a (L _b ) ₂ L is of the structure of _a Selected from the group consisting of L _a1 -L _a3456 Group of L _b Is selected identically or differently on each occurrence from the group consisting of L _b1 -L _b156 Either or both of the group consisting of;

preferably, the metal complex is selected from the group consisting of metal complex 1 to metal complex 4764, wherein metal complex 1 to metal complex 4764 have IrL _a (L _b ) ₂ Two L' s _b Identical, L _a And L _b Respectively corresponding to the structures indicated in the following table:

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18. an electroluminescent device, comprising: an anode is provided with a cathode,

a cathode electrode, which is arranged on the surface of the cathode,

and an organic layer disposed between the anode and cathode, the organic layer comprising the metal complex of any one of claims 1-17.

19. The electroluminescent device of claim 18 wherein the organic layer is a light emitting layer.

20. The electroluminescent device of claim 19 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 host compound and/or the second host compound comprises at least one chemical group selected from the group consisting of: benzene, pyridine, pyrimidine, triazine, carbazole, azacarbazole, indolocarbazole, dibenzothiophene, azadibenzothiophene, dibenzofuran, azadibenzofuran, dibenzoselenophene, triphenylene, azatriphenylene, fluorene, silafluorene, naphthalene, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene, azaphenanthrene, and combinations thereof.

21. A compound composition comprising the metal complex of any one of claims 1-17.