CN118344405A

CN118344405A - Organic electroluminescent material and device thereof

Info

Publication number: CN118344405A
Application number: CN202310073866.4A
Authority: CN
Inventors: 张奇; 代志洪; 路楠楠; 邝志远; 夏传军
Original assignee: Beijing Summer Sprout Technology Co Ltd
Current assignee: Beijing Summer Sprout Technology Co Ltd
Filing date: 2023-01-16
Publication date: 2024-07-16

Abstract

Disclosed are a metal complex having the general formula M (L _a)_m(L_b)_n(L_c)_q), the first ligand L _a having the structure of formula 1 and the second ligand L _b having the structure of formula 2, which is useful as a light emitting material in an organic electroluminescent device, the novel metal complex can effectively adjust an emission wavelength, red-shift the emission wavelength while maintaining a narrow half-peak width, better meet the requirement of saturated orange-red light emission, and greatly improve device efficiency, and provide better device performance.

Description

Organic electroluminescent material and device thereof

Technical Field

The present invention relates to a compound for an organic electronic device, such as an organic light emitting device. More particularly, to a metal complex comprising a ligand having the structure L _a of formula 1, and an organic electroluminescent device and a compound composition 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 (OLETs), organic photovoltaic devices (OPVs), dye-sensitized solar cells (DSSCs), organic optical detectors, organic photoreceptors, organic field effect devices (OFQDs), light emitting electrochemical cells (LECs), organic laser diodes and organic electroluminescent devices.

In 1987, tang and Van Slyke of Isomangan 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 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.

US20160164012A1 discloses a kit comprising a composition havingThe metal complexes of structural ligands, of which the interest is the metal complexes of such ligands with a silicon-based substitution at the 5-position of the pyridyl group in common with phenylpyridine type ligands, do not disclose or teach specifically the metal complexes of such ligands in common with diketone ligands nor the special effects of silicon-based substitution at other positions of such ligands, especially at the para-position of the pyridyl group.

KR20130110934A discloses a food product havingThe metal complex of the general structure does not disclose or teach a metal complex shared by the ligand with a specific condensed ring structure and a diketone ligand, and does not disclose or teach different effects caused by silicon-based substitution at a specific position of the ligand, especially does not pay attention to special effects caused by the silicon-based substitution at the para position of a pyridyl group in the ligand.

With the wide application of OLED devices, the requirements and standards for light emitting materials are also increasing. There is still room for further improvement in the light-emitting materials reported at present, and in order to meet the increasing demands of the industry, especially the demands for more saturated light emission of different colors, lower device voltage, longer device life and higher device efficiency, the novel light-emitting materials still need further research and development.

Disclosure of Invention

The present invention aims to solve at least part of the above problems by providing a series of novel metal complexes comprising an L _a ligand having the structure of formula 1. The novel metal complex can effectively regulate the emission wavelength, can enable the emission wavelength to be red-shifted under the level of maintaining a narrower half-peak width, better meets the requirement of saturated orange-red luminescence, can greatly improve the device efficiency and can provide better device performance.

According to one embodiment of the invention, a metal complex is disclosed having the general formula M (L _a)_m(L_b)_n(L_c)_q; wherein the metal M is selected from metals having a relative atomic mass greater than 40; the L _a、L_b and L _c are the first, second and third ligands of the complex, respectively; M is 1 or 2;n is 1 or 2;q is 0 or 1; m+n+q is equal to the oxidation state of the metal M; when M is 2, two L _a are the same or different; when n is 2, two L _b are the same or different; L _a、L_b and L _c can optionally be linked to form a multidentate ligand);

The L _a has a structure represented by formula 1:

Wherein,

Ring B is, identically or differently, selected for each occurrence from a five-membered unsaturated carbocycle, an aromatic ring having 6 to 30 carbon atoms or a heteroaromatic ring having 3 to 30 carbon atoms;

K is selected identically or differently on each occurrence from a single bond, O or S;

W is selected from Si or Ge;

x ₁-X₃ is selected identically or differently on each occurrence from N or CR _i;

A ₁-A₂ is selected identically or differently on each occurrence from N or CR _A;

r _ii, identically or differently for each occurrence, represents monosubstituted, polysubstituted or unsubstituted;

R ₁,R₂,R₃,R_i,R_A and R _ii are 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;

adjacent substituents R _i,R₁,R₂ and R ₃ can optionally be linked to form a ring;

Adjacent substituents R _A and R _ii can optionally be linked to form a ring;

Wherein L _b has a structure represented by formula 2:

R _t to R _z are, identically or differently, selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted 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;

Adjacent substituents R _t,R_u,R_v,R_w,R_x,R_y,R_z can optionally be linked to form a ring;

Wherein L _c is selected identically or differently from the group consisting of:

Wherein,

R _a、R_b and R _c, which are identical or different at each occurrence, represent monosubstituted, polysubstituted or unsubstituted;

X _b is selected identically or differently on each occurrence from the group consisting of: o, S, se, NR _N1 and CR _C1R_C2;

r _a、R_b、R_c、R_N1、R_C1 and R _C2 are 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;

Adjacent substituents R _a、R_b、R_c、R_N1、R_C1 and R _C2 can optionally be linked to form a ring.

According to another embodiment of the present invention, there is also disclosed an electroluminescent device including an anode, a cathode, and an organic layer disposed between the anode and the cathode; wherein the organic layer comprises a metal complex as described above.

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

The novel metal complex disclosed by the invention has the general formula of M (L _a)_m(L_b)_n(L_c)_q), the first ligand L _a has the structure of formula 1, and the second ligand L _b has the structure of formula 2.

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 various layers and exemplary materials are described in more detail in U.S. patent US7,279,704B2 at 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 m-MTDATA doped with F ₄ -TCNQ at a molar ratio of 50:1, as disclosed in U.S. patent application publication No. 2003/0230980, which is incorporated by reference in its entirety. 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 single-triplet energy gap (Δe _S -T). Organic non-metal containing donor-acceptor luminescent materials may be able to achieve this. The emission of these materials is typically characterized as 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 L _a has a structure represented by formula 1:

Wherein,

W is selected from Si or Ge;

Adjacent substituents R _A and R _ii can optionally be linked to form a ring;

Wherein L _b has a structure represented by formula 2:

Wherein,

In this embodiment, L _a、L_b and L _c can optionally be linked to form a multidentate ligand, which is intended to mean that any 2 or 3 of L _a、L_b and L _c can be linked to form a tetradentate ligand or a hexadentate ligand. Obviously, both L _a、L_b and L _c may also be unconnected so as not to form a multidentate ligand.

Herein, adjacent substituents R _i,R₁,R₂ and R ₃ can optionally be linked to form a ring, intended to mean groups of substituents wherein adjacent substituents, for example, adjacent substituents R ₁ and R ₂, adjacent substituents R ₂ and R ₃, adjacent substituents R ₁ and R ₃, adjacent substituent R _i, any one or more of these adjacent substituents can be linked to form a ring. Obviously, none of these adjacent substituents may be linked to form a ring.

Herein, adjacent substituents R _A and R _ii can optionally be linked to form a ring, and are intended to mean wherein adjacent substituents R _A and R _ii, two adjacent substituents R _A, and two adjacent substituents R _ii can be linked to form a ring, and obviously none of these adjacent substituents can be linked to form a ring.

Herein, adjacent substituents R _t,R_u,R_v,R_w,R_x,R_y and R _z can optionally be linked to form a ring, intended to mean groups of substituents wherein adjacent substituents, for example, adjacent substituents R _t and R _u, adjacent substituents R _t and R _z, adjacent substituents R _x and R _y, adjacent substituents R _y and R _z, adjacent substituents R _u and R _v, adjacent substituents R _w and R _v, any one or more of these adjacent substituents can be linked to form a ring. Obviously, none of these adjacent substituents may be linked to form a ring.

Herein, adjacent substituents R _a、R_b、R_c、R_N1、R_C1 and R _C2 can optionally be joined to form a ring, intended to mean groups of substituents wherein adjacent substituents, for example, between two substituents R _a, between two substituents R _b, Between the two substituents R _c, between the substituents R _a and R _b, between the substituents R _a and R _c, Between substituents R _b and R _c, between substituents R _a and R _N1, between substituents R _b and R _N1, Between substituents R _a and R _C1, between substituents R _a and R _C2, between substituents R _b and R _C1, Any one or more of these substituents may be linked to form a ring between substituents R _b and R _C2, and between R _C1 and R _C2. obviously, these substituents may not all be linked to form a ring.

According to one embodiment of the invention, wherein the metal M is selected from Ir, rh, re, os, pt, au or Cu.

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

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

According to one embodiment of the invention, ring B is selected identically or differently on each occurrence from aromatic rings having 6 to 18 carbon atoms or heteroaromatic rings having 3 to 18 carbon atoms.

According to one embodiment of the invention, wherein ring B is selected identically or differently on each occurrence from a benzene ring, a naphthalene ring, a pyridine ring, a quinoline ring, an isoquinoline ring, a thiophene ring, a furan ring, a selenophene ring, a benzofuran ring, a benzothiophene ring, a benzoselenophene ring, an azabenzofuran ring, an azabenzothiophene ring, a dibenzofuran ring or a dibenzothiophene ring.

According to one embodiment of the invention, ring B is selected, identically or differently, for each occurrence, from a benzene ring, a pyridine ring, a naphthalene ring, a benzofuran ring or a benzothiophene ring.

According to one embodiment of the invention, wherein X ₁ and X ₂ are, identically or differently, selected from CR _i for each occurrence; and two adjacent substituents R _i in X ₁ and X ₂ are linked to form a ring.

According to one embodiment of the invention, wherein X ₁ and X ₂ are, identically or differently, selected from CR _i for each occurrence; and two adjacent substituents R _i in X ₁ and X ₂ are joined to form a 5-membered unsaturated carbocyclic ring, a benzene ring, a 5-membered heteroaromatic ring or a 6-membered heteroaromatic ring.

According to one embodiment of the invention, wherein X ₁ and X ₂ are, identically or differently, selected from CR _i for each occurrence; and two adjacent substituents R _i in X ₁ and X ₂ are linked to form a benzene ring.

According to one embodiment of the invention, wherein the L _a is selected identically or differently on each occurrence from the group consisting of compounds having the formulae 3 to 3

A structure represented by any one of formula 14:

Wherein,

W is selected from Si or Ge;

Z ₁-Z₂ is selected identically or differently on each occurrence from CR _z1R_z1,SiR_z1R_z1,GeR_z1R_z1,NR_z1,PR_z1, O, S or Se;

q ₁-Q₄ is selected identically or differently on each occurrence from N or CR _Q;

B ₁-B₆ is selected identically or differently on each occurrence from N or CR _B;

R ₁,R₂,R₃,R_i,R_A,R_B,R_Q and R _z1 are 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;

Adjacent substituents R ₁,R₂ and R ₃ can optionally be linked to form a ring;

Adjacent substituents R _A and R _B can optionally be linked to form a ring.

Herein, adjacent substituents R ₁,R₂ and R ₃ can optionally be linked to form a ring, intended to mean groups of substituents wherein adjacent substituents, for example, adjacent substituents R ₁ and R ₂, adjacent substituents R ₂ and R ₃, adjacent substituents R ₁ and R ₃, any one or more of these adjacent substituents can be linked to form a ring. Obviously, none of these adjacent substituents may be linked to form a ring.

In this embodiment, adjacent substituents R _A and R _B can optionally be joined to form a ring, which is intended to mean that any one or more of the adjacent substituents may be joined to form a ring between two of the adjacent substituents R _A, between two of the adjacent substituents R _B, between adjacent substituents R _B and R _A. Obviously, none of these adjacent substituents may be linked to form a ring.

According to one embodiment of the present invention, wherein L _a is selected from the structures represented by formula 3, formula 7, formula 8, formula 9, or formula 10.

According to one embodiment of the present invention, wherein L _a is selected from the structures represented by formula 3 or formula 10.

According to one embodiment of the invention, wherein W is selected from Si.

According to one embodiment of the invention, wherein R ₁ to R ₃ are, identically or differently, selected from the group consisting of: substituted or unsubstituted alkyl groups having from 1 to 20 carbon atoms, substituted or unsubstituted aryl groups having from 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having from 3 to 30 carbon atoms, substituted or unsubstituted aralkyl groups having from 7 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having from 3 to 20 ring carbon atoms, and combinations thereof;

Adjacent substituents R ₁,R₂ and R ₃ can optionally be linked to form a ring.

According to one embodiment of the present invention, wherein, in the formulas 6,7, when B ₁ is selected from CR _B, the R _B is selected, identically or differently, at 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 alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted aminogermyl having 6 to 20 carbon atoms, substituted or unsubstituted aminogermyl having 0 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, carbonyl, isocyanate, sulfonyl, and combinations thereof.

According to one embodiment of the present invention, wherein, in the formulas 6, 7, the R _A and R _B are selected identically or differently at 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 alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 3 to 20 carbon atoms, substituted or unsubstituted aminogermyl having 6 to 20 carbon atoms, substituted or unsubstituted aminogermyl having 0 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, carbonyl, hydroxyl, sulfonyl, mercapto, sulfonyl, and combinations thereof.

According to one embodiment of the present invention, in the formula 4, formula 5, formula 11, formula 12, adjacent substituents R _B are not connected to form a ring.

According to one embodiment of the present invention, wherein in the formulae 10 to 12, adjacent substituents R _i in Q ₁ to Q ₄ are not linked to form a ring.

According to one embodiment of the present invention, wherein in formulae 3 to 14, at least one of a ₁-A₂ is selected from CR _A, and each occurrence of said R _A is identically or differently selected from the group consisting of: 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 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 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 alkylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted aminogermyl having 0 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, cyano, mercapto, and combinations thereof.

According to one embodiment of the invention, wherein in formulae 3 to 14, a ₂ is selected from CR _A and the R _A is, identically or differently, selected from the group consisting of: 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 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 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 alkylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted aminogermyl having 0 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, cyano, mercapto, and combinations thereof.

According to one embodiment of the invention, wherein in formulae 3 to 14, a ₂ is selected from CR _A, and said R _A is selected, identically or differently, on each occurrence, from the group consisting of: 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 heterocyclyl having 3 to 20 ring 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 group having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanium group having 6 to 20 carbon atoms, cyano, and combinations thereof.

According to one embodiment of the invention, wherein in formulae 3 to 14, a ₂ is selected from CR _A, and said R _A is selected, identically or differently, on each occurrence, from the group consisting of: deuterium, fluoro, cyano, methyl, isopropyl, isobutyl, tert-butyl, neopentyl, cyclopentyl, cyclopentylmethyl, cyclohexyl, norbornyl, adamantyl, tetrahydropyranyl, trimethylsilyl, phenyldimethylsilyl, triethylsilyl, trimethylgermanium, triethylgermanium, phenyl, pyridinyl, triazinyl, and combinations thereof.

According to one embodiment of the present invention, wherein in formulae 3 to 14, at least one of B ₁-B₆ is selected from CR _B, and the R _B is selected, identically or differently, at each occurrence, from the group consisting of: 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 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 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 alkylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted aminogermyl having 0 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, cyano, mercapto, and combinations thereof.

According to one embodiment of the present invention, wherein, in formula 3, formula 6 to formula 10, formula 13 and formula 14, at least one of B ₂ to B ₄ is selected from CR _B; in formula 4, formula 5, formula 11 and formula 12, B ₂ is selected from CR _B; and each occurrence of said R _B is the same or different selected from the group consisting of: 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 heterocyclyl having 3 to 20 ring 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, cyano, hydroxy, mercapto, and combinations thereof.

According to one embodiment of the invention, wherein said R _B is selected identically or differently on each occurrence from the group consisting of: deuterium, fluoro, cyano, methyl, isopropyl, isobutyl, tert-butyl, neopentyl, cyclopentyl, cyclopentylmethyl, cyclohexyl, norbornyl, adamantyl, tetrahydropyranyl, trimethylsilyl, phenyldimethylsilyl, triethylsilyl, trimethylgermanium, triethylgermanium, phenyl, pyridinyl, triazinyl, and combinations thereof.

According to one embodiment of the invention, wherein in said formulae 3 to 14, X ₁-X₃ is selected identically or differently for each occurrence from CR _i,Q₁-Q₄ and identically or differently for each occurrence from CR _Q,A₁-A₂ and identically or differently for each occurrence from CR _A,B₁-B₆ and identically or differently for each occurrence from CR _B.

According to one embodiment of the invention, wherein in the formulae 3 to 14, X ₁-X₃ is selected identically or differently for each occurrence from CR _i,Q₁-Q₄, identically or differently for each occurrence from CR _Q,A₁-A₂, identically or differently for each occurrence from CR _A,B₁-B₆, identically or differently from CR _B, and the R _i,R_Q,R_A and R _B are selected identically or differently for 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 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, carboxyl, hydroxyl, sulfonyl, mercapto, sulfonyl, and combinations thereof.

According to one embodiment of the invention, wherein in the formulae 3 to 14, X ₁-X₃ is selected identically or differently for each occurrence from CR _i,Q₁-Q₄, identically or differently for each occurrence from CR _Q,A₁-A₂, identically or differently for each occurrence from CR _A,B₁-B₆, identically or differently from CR _B, and the R _i,R_Q,R_A and R _B are selected identically or differently for 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 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, 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 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, cyano, and combinations thereof.

According to one embodiment of the invention, wherein each occurrence of said R _i,R_Q,R_A and R _B is identically or differently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, 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, cyano, and combinations thereof.

According to one embodiment of the invention, wherein at least one of X ₁-X₃ and/or Q ₁-Q₄ is selected from N.

According to one embodiment of the invention, wherein at least one of X ₁-X₃ is selected from N.

According to one embodiment of the invention, wherein X ₂ and/or X ₃ are selected from N.

According to one embodiment of the invention, wherein X ₂ is selected from N.

According to one embodiment of the invention, wherein, in formulae 4 to 7, formulae 11 to 14, Z ₁ and Z ₂ are, identically or differently, selected from O, S or Se for each occurrence.

According to an embodiment of the present invention, wherein the L _a has a structure represented by formula 3-1:

Wherein,

X ₂ is selected from N or CR _i;

W is selected from Si or Ge;

R ₁ to R ₃ are each independently selected from the group consisting of: substituted or unsubstituted alkyl groups having from 1 to 20 carbon atoms, substituted or unsubstituted aryl groups having from 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having from 3 to 30 carbon atoms, substituted or unsubstituted aralkyl groups having from 7 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having from 3 to 20 ring carbon atoms, and combinations thereof;

R _i,R_i1,R_i2,R_A1,R_A2,R_B1,R_B2 and R _B3 are 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;

Adjacent substituents R _i,R_i1,R₁ to R ₃ can optionally be linked to form a ring;

Adjacent substituents R _A1,R_A2,R_B1,R_B2 and R _B3 can optionally be linked to form a ring.

In this embodiment, adjacent substituents R _i,R_i1,R₁ to R ₃ can optionally be linked to form a ring, and are intended to mean groups of substituents wherein adjacent substituents, for example, adjacent substituents R _i and R _i1, adjacent substituents R ₁ and R ₂, adjacent substituents R ₂ and R ₃, adjacent substituents R ₁ and R ₃, any one or more of these adjacent substituents can be linked to form a ring. Obviously, none of these adjacent substituents may be linked to form a ring.

In this embodiment, adjacent substituents R _A1,R_A2,R_B1,R_B2 and R _B3 can optionally be linked to form a ring, which is intended to mean wherein adjacent groups of substituents, for example, adjacent substituents R _A1 and R _A2, adjacent substituents R _A2 and R _B1, adjacent substituents R _B1 and R _B2, adjacent substituents R _B2 and R _B3, any one or more of these adjacent substituents can be linked to form a ring. Obviously, none of these adjacent substituents may be linked to form a ring.

According to one embodiment of the invention, wherein at least one of R _A2,R_B2 and R _B3 is, for each occurrence, identically or differently selected from the group consisting of: 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 groups having from 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having from 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl groups having from 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl groups having from 6 to 20 carbon atoms, substituted or unsubstituted alkylgermanium groups having from 3 to 20 carbon atoms, substituted or unsubstituted arylgermanium groups having from 6 to 20 carbon atoms, substituted or unsubstituted amino groups having from 0 to 20 carbon atoms, acyl groups, carbonyl groups, carboxylic acid groups, ester groups, cyano groups, isocyano groups, hydroxyl groups, mercapto groups, sulfinyl groups, sulfonyl groups, phosphino groups, and combinations thereof.

According to one embodiment of the invention, wherein at least one of R _A2,R_B2 and R _B3 is, for each occurrence, identically or differently selected from the group consisting of: deuterium, halogen, cyano, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring 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 having 3 to 20 carbon atoms, and combinations thereof.

According to one embodiment of the invention, wherein R _A2 is selected identically or differently on each occurrence from the group consisting of: deuterium, halogen, cyano, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring 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 alkylgermanium group having 3 to 20 carbon atoms, and combinations thereof.

According to an embodiment of the invention, wherein L _a is selected from the group consisting of L _a1 to L _a485, the specific structure of said L _a1 to L _a485 is given in claim 12.

According to one embodiment of the invention, wherein the hydrogen energy in the structures of L _a1 to L _a485 is partially or completely replaced by deuterium.

According to one embodiment of the present invention, wherein L _b has a structure represented by formula 2:

At least one or both of R _x,R_y and R _z are, identically or differently, selected from 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 heteroalkyl groups having 1 to 20 carbon atoms, or combinations thereof; and/or at least one or both of R _u,R_v and R _w are, identically or differently, 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, substituted or unsubstituted heteroalkyl groups having from 1 to 20 carbon atoms, or combinations thereof.

At least two of R _x,R_y and R _z are, identically or differently, selected from the group consisting of substituted or unsubstituted alkyl groups having from 2 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having from 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having from 2 to 20 carbon atoms, or combinations thereof; and/or at least two of R _u,R_v and R _w are, identically or differently, selected from substituted or unsubstituted alkyl groups having from 2 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having from 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having from 2 to 20 carbon atoms, or combinations thereof.

According to an embodiment of the invention, wherein L _b is selected from the group consisting of L _b1 to L _b322, the specific structure of said L _b1 to L _b322 is given in claim 14.

According to an embodiment of the invention, wherein L _c is selected from the group consisting of L _c1 to L _c231, the specific structure of said L _c1 to L _c231 is given in claim 14.

According to one embodiment of the invention, wherein the metal complex is an Ir complex and has the structure of Ir (L _a)₂(L_b)、Ir(L_a)(L_b)₂ or Ir (L _a)(L_b)(L_c); When the metal complex has the structure of Ir (L _a)₂(L_b), the L _a is, for each occurrence, either or both of the same or different selected from the group consisting of L _a1 to L _a485, L _b is any one selected from the group consisting of L _b1 to L _b322; When the metal complex has Ir (structure of L _a)(L_b)₂), L _a is any one selected from the group consisting of L _a1 to L _a485, L _b is, identically or differently, at each occurrence, any one or any two selected from the group consisting of L _b1 to L _b322; When the metal complex has a structure of Ir (L _a)(L_b)(L_c), the L _a is selected from any one of the group consisting of L _a1 to L _a485, The L _b is any one selected from the group consisting of L _b1 to L _b322, and the L _c is any one selected from the group consisting of L _c1 to L _c231.

According to another embodiment of the present invention, wherein the metal complex is selected from the group consisting of compounds 1 to 368, the specific structure of compounds 1 to 368 is as defined in claim 15.

According to one embodiment of the invention, the hydrogen in the structures of compounds 1 to 368 can be partially or fully substituted with deuterium.

According to an embodiment of the present invention, there is also disclosed an electroluminescent device including:

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 the cathode, the organic layer comprising a metal complex, the specific structure of the metal complex being as described in any of the foregoing embodiments.

According to one embodiment of the invention, in the electroluminescent device, the organic layer is a light emitting layer and the metal complex is a light emitting material.

According to one embodiment of the invention, the electroluminescent device emits red or white light.

According to one embodiment of the invention, in the electroluminescent device, the light-emitting layer further comprises at least one host material.

According to one embodiment of the invention, the at least one host material 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 at least one host material may be a conventional host material of the prior art, for example, may typically, but not limited to, include the following host materials:

according to another embodiment of the present invention, there is also disclosed a compound composition comprising a metal complex having a specific structure as shown in 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, the evaporator manufactured by Angstrom Engineering, the optical test system manufactured by Frieda, st. O. F. And the lifetime test system, 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 Compound 80

Step 1: synthesis of intermediate 3

Intermediate 1 (5.00 g,20.90 mmol) was added to the reaction flask, after nitrogen substitution, the reaction system was cooled to-72 ℃, lithium isopropylmagnesium chloride solution (20.90 ml,27.10mmol,1.3 m) was slowly added dropwise thereto, after 30min reaction at this temperature, intermediate 2 (5.35 g,31.40 mmol) was added to the reaction system, slowly warmed to room temperature, after completion of TLC detection, saturated ammonium chloride was added to quench the reaction, the organic phase was separated, the aqueous phase was extracted with ethyl acetate, and after combining the organic phases, column chromatography was performed to obtain intermediate 3 (0.47 g, yield 9.10%).

Step 2: synthesis of intermediate 5

Intermediate 3 (0.47 g,1.92 mmol), intermediate 4(0.65g,2.10mmol),Pd(PPh₃)₄(0.11g,0.10mmol),Na₂CO₃(0.31g,2.88mmol),1,4- dioxane (15 mL) and water (5 mL) were added to the flask, the system was purged with nitrogen three times, heated to reflux, reacted overnight, after TLC detection was complete, the organic phase was separated, the aqueous phase was extracted with ethyl acetate, the organic phases were combined, and purified by column chromatography to give intermediate 5 (0.72 g, 95% yield).

Step 3: synthesis of Iridium dimers

Intermediate 5 (0.72 g,1.82 mmol), iridium trichloride trihydrate (0.22 g,0.60 mmol), ethylene glycol diethyl ether (15 mL) and water (5 mL) were added to a round bottom flask, and the reaction was refluxed at 135℃for 24 hours under nitrogen protection. After cooling to room temperature, iridium dimer was obtained by filtration.

Step 4: synthesis of Compound 80

A mixture of iridium dimer obtained in the previous step, 3, 7-diethyl-3-methylnonane-4, 6-dione (0.22 g,0.9 mmol), K ₂CO₃ (0.42 g,3 mmol) and ethylene glycol diethyl ether (15 mL) was stirred at 50℃under nitrogen for 24 hours. After the reaction was complete, the precipitate was filtered through celite and washed with ethanol. Dichloromethane was added to the resulting solid and the filtrate was collected. Ethanol was then added and the resulting solution was concentrated. After filtration, compound 80 (0.14 g, yield 19%) was obtained, which was confirmed to be the target product, having a molecular weight of 1206.55.

Synthesis example 2: synthesis of Compound 77

Step 1: synthesis of intermediate 7:

Intermediate 6 (1.21 g,6.53 mmol), intermediate 4 (2.02 g,6.53 mmol), tetrakis triphenylphosphine palladium (0.38 g,0.33 mmol), sodium carbonate (1.04 g,9.80 mmol), 1, 4-dioxane (24 mL) and water (6 mL) were added to a 100mL round bottom flask, then the reaction was heated to reflux under nitrogen and stirred overnight, after TLC showed completion, it was cooled to room temperature. Then ethyl acetate was added to the reaction, the liquid was separated, the aqueous phase was extracted with ethyl acetate, the organic phases were combined, dried, and spin-dried to give a crude product, which was separated by silica gel column chromatography to give the objective product as colorless oily liquid intermediate 7 (2.03 g, yield 93.2%).

Step 2: synthesis of iridium dimers:

a mixture of intermediate 7 (2.03 g,6.03 mmol), iridium trichloride trihydrate (0.58 g,1.64 mmol), 2-ethoxyethanol (18 mL) and water (6 mL) was refluxed under nitrogen for 24 hours. After cooling to room temperature, the water in the solution was removed by rotary evaporation to give an ethoxyethanol solution of dimer, which was used in the next reaction without further purification.

Step 3: synthesis of Compound 77

An ethoxyethanol solution of iridium dimer obtained in the previous step, 3, 7-diethyl-3-methylnonane-4, 6-dione (0.56 g,2.46 mmol) and potassium carbonate (1.13 g,8.2 mmol) were added to a 100mL round bottom flask and reacted at 60℃under nitrogen for 24 hours. It was then poured into a funnel containing celite, filtered and washed with ethanol. Dichloromethane was added to the resulting solid and the filtrate was collected. Ethanol was then added and the resulting solution was concentrated. After filtration, compound 77 (0.98 g, yield 55.2%) was obtained. The product was further purified by column chromatography. The product was identified as the target product and molecular weight 1082.51.

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 embodiment

Device example 1

First, a glass substrate having a 120nm 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 designated below was sequentially evaporated on the ITO anode by thermal vacuum evaporation at a rate of 0.06-2 Angstrom/second under a vacuum of about 10 ^-8 Torr. Compounds HT and HI were used as hole injection layers (HIL, weight ratio 97:3), thicknessThe compound HT is used as a Hole Transport Layer (HTL), thicknessCompound EB used as Electron Blocking Layer (EBL), thicknessThen, the compound 80 of the present invention was doped in host compounds RH1 and RH2 to serve as light emitting layers (EML, weight ratio 6:37.5:56.5), thicknessCompound HB is used as Hole Blocking Layer (HBL), thicknessOn the HBL, the compound ET and 8-hydroxyquinoline-lithium (Liq) were co-deposited as electron transport layers (ETL, weight ratio 40:60), thicknessFinally, liq 1nm thick was deposited as an electron injection layer, and Al 120nm was deposited as a cathode. The device was then transferred back to the glove box and encapsulated with a glass cover and a moisture absorbent to complete the device.

Device example 2

Device example 2 was prepared in the same manner as device example 1, except that compound 77 was used in place of compound 80 of the present invention in the light-emitting layer (EML).

Device comparative example 1

Device comparative example 1 was prepared in the same manner as device example 1 except that compound RD was used in place of compound 80 of the present invention in the light-emitting layer (EML).

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 for device examples 1-2 and comparative example 1

The structure of the materials used in the device is as follows:

Table 2 shows the CIE data, maximum emission wavelength (λ _max), full width at half maximum (FWHM), current Efficiency (CE), power Efficiency (PE) and External Quantum Efficiency (EQE) data of example 1, example 2 and comparative example 1 measured at a constant current density of 15mA/cm ².

Table 2 device data

Discussion: as can be seen from the data in table 2, the maximum emission wavelengths of examples 1 and 2 of the device of the present application are 594nm and 590nm, respectively, each achieving a different degree of pronounced red shift compared to comparative example 1. In addition, the half-width of comparative example 1 is already at an extremely narrow level, but the device examples 1,2 of the present application also have half-widths at an extremely narrow level, indicating that the metal complex having a silicon-based substitution at a specific position of the L _a ligand of the present application can effectively adjust the emission wavelength while achieving saturated luminescence.

Moreover, in terms of power efficiency, the power efficiency of comparative example 1 has reached a higher level of 34.9lm/W, but example 1 still achieves a further boost, reaching a higher level of 36.2 lm/W; in terms of current efficiency, example 1 also achieved a 6% improvement. Both the current efficiency and the power efficiency of example 2 achieved an improvement of about 8%. Even more surprisingly, the external quantum efficiencies of example 1 and example 2 were significantly improved by 27% and 21% respectively over comparative example 1, further highlighting the unique advantages of the metal complexes of the present invention. The above shows that the metal complex of the present invention comprising the ligand of formula 1 having a silicon-based substitution at a specific position achieves more excellent device performance in the application to an organic electroluminescent device than the comparative example compound RD.

In summary, the metal complex disclosed by the invention can effectively adjust the emission wavelength to better meet the requirement of saturated orange-red light emission while realizing saturated light emission, and most importantly, can greatly improve the current efficiency, the power efficiency and the external quantum efficiency of the device, thereby providing more excellent device performance.

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 the general formula M (L _a)_m(L_b)_n(L_c)_q; wherein the metal M is selected from metals having a relative atomic mass greater than 40; the L _a、L_b and L _c are the first, second and third ligands of the complex, respectively; M is 1 or 2;n is 1 or 2;q is 0 or 1; m+n+q equals the oxidation state of the metal M; when M is 2, two L _a are the same or different; when n is 2, two L _b are the same or different; L _a、L_b and L _c can optionally be linked to form a multidentate ligand);

The L _a has a structure represented by formula 1:

Wherein,

W is selected from Si or Ge;

Adjacent substituents R _A and R _ii can optionally be linked to form a ring;

Wherein L _b has a structure represented by formula 2:

Wherein,

2. The metal complex of claim 1, wherein the metal M is selected from Ir, rh, re, os, pt, au or Cu; preferably, the metal M is selected from Ir, pt or Os; more preferably, the metal M is Ir.

3. The metal complex of claim 1 or 2, wherein ring B is, identically or differently, selected for each occurrence from an aromatic ring having 6 to 18 carbon atoms or a heteroaromatic ring having 3 to 18 carbon atoms;

preferably, ring B is selected, identically or differently, for each occurrence, from a benzene ring, naphthalene ring, pyridine ring, quinoline ring, isoquinoline ring, thiophene ring, furan ring, selenophene ring, benzofuran ring, benzothiophene ring, benzoselenophene ring, azabenzofuran ring, azabenzothiophene ring, dibenzofuran ring or dibenzothiophene ring.

4. The metal complex of claim 1 or 2, the L _a at each occurrence is identically or differently selected from structures represented by any one of formulas 3 to 14:

Wherein,

W is selected from Si or Ge;

adjacent substituents R _A and R _B can optionally be linked to form a ring;

Preferably, the L _a is selected from the structures represented by formula 3, formula 7, formula 8, formula 9, or formula 10.

5. The metal complex of claim 1 or 4, wherein R ₁ to R ₃ are, identically or differently, selected from the group consisting of: substituted or unsubstituted alkyl groups having from 1 to 20 carbon atoms, substituted or unsubstituted aryl groups having from 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having from 3 to 30 carbon atoms, substituted or unsubstituted aralkyl groups having from 7 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having from 3 to 20 ring carbon atoms, and combinations thereof;

6. The metal complex of claim 4 or 5, wherein in formulae 3 to 14, at least one of a ₁-A₂ is selected from CR _A and the R _A is, identically or differently, selected from the group consisting of: 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 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 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 alkylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted aminogermyl having 0 to 20 carbon atoms, substituted or unsubstituted aminoxy having 0 to 20 carbon atoms, cyano, mercapto, and combinations thereof;

Preferably, a ₂ is selected from CR _A;

More preferably, the R _A is selected identically or differently on each occurrence from the group consisting of: 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 heterocyclyl having 3 to 20 ring 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 group having 3 to 20 carbon atoms, substituted or unsubstituted arylgermanium group having 6 to 20 carbon atoms, cyano, and combinations thereof;

Most preferably, the R _A is selected identically or differently on each occurrence from the group consisting of: deuterium, fluoro, cyano, methyl, isopropyl, isobutyl, tert-butyl, neopentyl, cyclopentyl, cyclopentylmethyl, cyclohexyl, norbornyl, adamantyl, tetrahydropyranyl, trimethylsilyl, phenyldimethylsilyl, triethylsilyl, trimethylgermanium, triethylgermanium, phenyl, pyridinyl, triazinyl, and combinations thereof.

7. The metal complex of claim 4 or 5, wherein in formulae 3 to 14, at least one of B ₁-B₆ is selected from CR _B and the R _B is, identically or differently, selected from the group consisting of: 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 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 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 alkylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted arylgermyl having 6 to 20 carbon atoms, substituted or unsubstituted aminogermyl having 0 to 20 carbon atoms, substituted or unsubstituted aminoxy having 0 to 20 carbon atoms, cyano, mercapto, and combinations thereof;

Preferably, in formula 3, formula 6 to formula 10, formula 13 and formula 14, at least one of B ₂ to B ₄ is selected from CR _B; in formula 4, formula 5, formula 11 and formula 12, B ₂ is selected from CR _B; and each occurrence of said R _B is the same or different selected from the group consisting of: 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 heterocyclyl having 3 to 20 ring 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, cyano, hydroxy, mercapto, and combinations thereof;

More preferably, the R _B is selected identically or differently on each occurrence from the group consisting of: deuterium, fluoro, cyano, methyl, isopropyl, isobutyl, tert-butyl, neopentyl, cyclopentyl, cyclopentylmethyl, cyclohexyl, norbornyl, adamantyl, tetrahydropyranyl, trimethylsilyl, phenyldimethylsilyl, triethylsilyl, trimethylgermanium, triethylgermanium, phenyl, pyridinyl, triazinyl, and combinations thereof.

8. The metal complex of any one of claims 4-7, wherein in formulae 3 to 14, X ₁-X₃ is selected identically or differently for each occurrence from CR _i,Q₁-Q₄, identically or differently for each occurrence from CR _Q,A₁-A₂, identically or differently for each occurrence from CR _A,B₁-B₆, from CR _B;

Preferably, each occurrence of said R _i,R_Q,R_A and R _B is identically or differently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted 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, 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 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, cyano, and combinations thereof.

9. The metal complex of claim 1 or 4, wherein at least one of X ₁-X₃ is selected from N; preferably, X ₂ is selected from N.

10. The metal complex of claim 4, wherein in formulae 4 to 7, formulae 11 to 14, Z ₁ and Z ₂ are identically or differently selected from O, S or Se at each occurrence.

11. The metal complex of claim 1, wherein the L _a has a structure represented by formula 3-1:

Wherein,

X ₂ is selected from N or CR _i;

W is selected from Si or Ge;

Adjacent substituents R _A1,R_A2,R_B1,R_B2 and R _B3 can optionally be linked to form a ring;

Preferably, at least one of R _A2,R_B2 and R _B3, at each occurrence, is identically or differently selected from the group consisting of: 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 groups having from 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl groups having from 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl groups having from 3 to 20 carbon atoms, substituted or unsubstituted alkylgermanium groups having from 3 to 20 carbon atoms, substituted or unsubstituted arylgermanium groups having from 6 to 20 carbon atoms, substituted or unsubstituted amino groups having from 0 to 20 carbon atoms, acyl groups, carbonyl groups, carboxylic acid groups, ester groups, cyano groups, isocyano groups, hydroxyl groups, mercapto groups, sulfinyl groups, sulfonyl groups, phosphino groups, and combinations thereof;

More preferably, at least one of R _A2,R_B2 and R _B3, at each occurrence, is identically or differently selected from the group consisting of: deuterium, halogen, cyano, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heterocyclyl having 3 to 20 ring 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 having 3 to 20 carbon atoms, and combinations thereof.

12. The metal complex of claim 1, wherein L _a is selected identically or differently on each occurrence from the group consisting of:

Optionally, the hydrogen in the structures of L _a1 to L _a485 can be partially or fully substituted with deuterium.

13. The metal complex of claim 1, wherein L _b has a structure represented by formula 2:

At least one or both of R _x,R_y and R _z are, identically or differently, selected from 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 heteroalkyl groups having 1 to 20 carbon atoms, or combinations thereof; and/or at least one or both of R _u,R_v and R _w are, identically or differently, 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, substituted or unsubstituted heteroalkyl groups having from 1 to 20 carbon atoms, or combinations thereof;

Preferably, at least two of R _x,R_y and R _z are, identically or differently, selected from the group consisting of substituted or unsubstituted alkyl groups having from 2 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having from 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having from 2 to 20 carbon atoms, or combinations thereof; and/or at least two of R _u,R_v and R _w are, identically or differently, selected from substituted or unsubstituted alkyl groups having from 2 to 20 carbon atoms, substituted or unsubstituted cycloalkyl groups having from 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having from 2 to 20 carbon atoms, or combinations thereof.

14. The metal complex of claim 1 or 12, wherein L _b is selected identically or differently on each occurrence from the group consisting of:

wherein L _c is selected identically or differently on each occurrence from the group consisting of:

15. The metal complex of claim 14, wherein the metal complex is an Ir complex and has the structure of Ir (L _a)₂(L_b)、Ir(L_a)(L_b)₂ or Ir (L _a)(L_b)(L_c); When the metal complex has the structure of Ir (L _a)₂(L_b), the L _a is, for each occurrence, either or both of the same or different selected from the group consisting of L _a1 to L _a485, L _b is any one selected from the group consisting of L _b1 to L _b322; When the metal complex has Ir (structure of L _a)(L_b)₂), L _a is any one selected from the group consisting of L _a1 to L _a485, L _b is, identically or differently, at each occurrence, any one or any two selected from the group consisting of L _b1 to L _b322; When the metal complex has a structure of Ir (L _a)(L_b)(L_c), the L _a is selected from any one of the group consisting of L _a1 to L _a485, The L _b is any one selected from the group consisting of L _b1 to L _b322, and the L _c is any one selected from the group consisting of L _c1 to L _c231;

Preferably, wherein the metal complex is selected from the group consisting of compound 1 to compound 368;

Wherein the compounds 1 to 240 have the structure Ir (L _a)₂(L_b) wherein two L _a are identical, L _a and L _b each correspond to a structure selected from the list of:

Wherein compounds 241 to 368 have the structure of Ir (L _a)₂(L_b), wherein two L _a are different, L _a and L _b each correspond to a structure selected from the list in the following table:

16. 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, wherein the organic layer comprises the metal complex of any one of claims 1-15.

17. The electroluminescent device of claim 16 wherein the organic layer is a light emitting layer and the metal complex is a light emitting material.

18. The electroluminescent device of claim 16, wherein the electroluminescent device emits red or white light.

19. The electroluminescent device of claim 17 wherein the light emitting layer further comprises at least one host material; preferably, the at least one host material 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.

20. A compound composition comprising the metal complex of any one of claims 1-15.