CN110713485A - Organic electroluminescent material and device - Google Patents

Abstract

The present invention relates to organic electroluminescent materials and devices. The invention discloses a compound, which has a structure shown in a formula I, A-L-B-M-D. In the structure of formula I: a is selected from

L is a linking group selected from: single bonds, aryl, heteroaryl, and combinations thereof, and may be further substituted; L-B-M has the following structure:

m is selected from aryl, heteroaryl, and combinations thereof, and may be further substituted; d has the following structure:

x is O, S, Se or CR 'R'; x¹‑X⁸、Y¹‑Y¹²、Z¹、Z³‑Z⁸And Z¹¹‑Z¹⁸Each independently is N or CR; each of R, R 'and R' is selected from a wide variety of substituents; wherein adjacent R substituents may form a fused ring; and R' may form a ring. Also described are formulations and devices, such as OLEDs, comprising the compounds of formula I.

Description

Organic electroluminescent material and device

This application is a divisional application of the application entitled "organic electroluminescent materials and devices" filed on 3/18/2015 with application number 201510119396.6.

Cross Reference to Related Applications

This application is a non-provisional application in accordance with the priority of U.S. provisional patent application No. 61/954,631 filed 2014 3/18/119 (e) requirements 35u.s.c. § 119(e), the entire contents of which are incorporated herein by reference.

Parties to a federated research agreement

The claimed invention is made by one or more of the following parties to a joint university company research agreement, in the name of and/or in conjunction with one or more of the following parties: the board of Michigan university, Princeton university, southern California university, and the world Display Corporation (Universal Display Corporation). The agreement is in effect on and before the date the claimed invention was made, and the claimed invention is made as a result of activities performed within the scope of the agreement.

Technical Field

The present invention relates to compounds suitable for use as hosts in organic light emitting diodes, and formulations and devices comprising the same.

Background

Optoelectronic devices utilizing organic materials are becoming increasingly popular for several reasons. Many of the materials used to make such devices are relatively inexpensive, and therefore organic optoelectronic devices have the potential to gain cost advantages over inorganic devices. In addition, the inherent properties of organic materials (e.g., their flexibility) may make them well suited for specific applications, such as fabrication on flexible substrates. Examples of organic optical electronic devices include Organic Light Emitting Devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, organic materials may have performance advantages over conventional materials. For example, the wavelength of light emitted by the organic emissive layer can generally be readily tuned with appropriate dopants.

OLEDs utilize organic thin films that emit light when a voltage is applied across the device. OLEDs are becoming an increasingly attractive technology for use in, for example, flat panel displays, lighting, and backlighting applications. Several OLED materials and configurations are described in U.S. patent nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety.

One application of phosphorescent emissive molecules is full color displays. Industry standards for such displays require pixels adapted to emit a particular color (referred to as a "saturated" color). In particular, these standards require saturated red, green and blue pixels. Color can be measured using CIE coordinates well known in the art.

An example of a green emissive molecule is tris (2-phenylpyridine) iridium, denoted Ir (ppy)₃It has the following structure:

in this and later figures herein, the dative bond from nitrogen to metal (here, Ir) is depicted as a straight line.

As used herein, the term "organic" includes polymeric materials as well as small molecule organic materials that may be used to fabricate organic optoelectronic devices. "Small molecule" refers to any organic material that is not a polymer, and "small molecules" may actually be quite large. In some cases, the small molecule may include a repeat unit. For example, the use of long chain alkyl groups as substituents does not remove the molecule from the "small molecule" class. Small molecules can also be incorporated into polymers, for example as a pendant group on the polymer backbone or as part of the backbone. Small molecules can also serve as the core moiety of a dendrimer, which consists of a series of chemical shells built on the core moiety. The core moiety of the dendrimer may be a fluorescent or phosphorescent small molecule emitter. Dendrimers can be "small molecules," and it is believed that all dendrimers currently used in the OLED art are small molecules.

As used herein, "top" means furthest from the substrate, and "bottom" means closest to the substrate. Where a first layer is described as being "disposed" on a second layer, the first layer is disposed farther from the substrate. Other layers may be present between the first and second layers, unless it is specified that the first layer is "in contact with" the second layer. For example, a cathode can 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 "photoactive" when it is believed that the ligand directly contributes to the photoactive properties of the emissive material. A ligand may be referred to as "ancillary" when it is believed that the ligand does not contribute to the photoactive properties of the emissive material, but the ancillary ligand may alter the properties of the photoactive ligand.

As used herein, and as will be generally understood by those skilled in the art, a first "highest occupied molecular orbital" (HOMO) or "lowest unoccupied molecular orbital" (LUMO) energy level is "greater than" or "higher than" a second HOMO or LUMO energy level if the first energy level is closer to the vacuum energy level. Since Ionization Potential (IP) is measured as negative energy relative to vacuum level, a higher HOMO level corresponds to an IP with a smaller absolute value (IP that is less negative). Similarly, a higher LUMO energy level corresponds to an Electron Affinity (EA) having a smaller absolute value (EA that is less negative). On a conventional energy level diagram, the vacuum level is at the top and the LUMO level of a material is higher than the HOMO level of the same material. The "higher" HOMO or LUMO energy level appears closer to the top of this figure than the "lower" HOMO or LUMO energy level.

As used herein, and as will be generally understood by those skilled in the art, a first work function is "greater than" or "higher than" a second work function if the first work function has a higher absolute value. Since work function is typically measured as negative relative to vacuum level, this means that a "higher" work function is more negative. On a conventional energy level diagram, the vacuum level is at the top, illustrating the "higher" work function as being farther from the vacuum level in the downward direction. Thus, the definitions of HOMO and LUMO energy levels follow a different convention than work functions.

Further details regarding OLEDs and the definitions described above may be found in U.S. patent No. 7,279,704, which is incorporated herein by reference in its entirety.

Disclosure of Invention

According to one embodiment, a compound is described having the structure of formula I:

A-L-B-M-D，

in the structure of formula I:

a is selected from the group consisting of:

l is a linking group selected from the group consisting of: a single bond, aryl having 6 to 30 carbon atoms, heteroaryl having 3 to 30 carbon atoms, and combinations thereof;

when L is aryl or heteroaryl, L is optionally further substituted by one or more groups selected from: hydrogen, deuterium, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, and combinations thereof;

L-B-M has the following structure:

m is selected from the group consisting of: aryl having 6 to 30 carbon atoms, heteroaryl having 3 to 30 carbon atoms, and combinations thereof;

m is optionally further substituted with one or more groups selected from: hydrogen, deuterium, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, and combinations thereof;

d has the following structure:

x is selected from the group consisting of: o, S, Se and CR 'R';

X¹、X²、X³、X⁴、X⁵、X⁶、X⁷、X⁸、Y¹、Y²、Y³、Y⁴、Y⁵、Y⁶、Y⁷、Y⁸、Y⁹、Y¹⁰、Y¹¹、Y¹²、Z¹、Z³、Z⁴、Z⁵、Z⁶、Z⁷、Z⁸、Z¹¹、Z¹²、Z¹²、Z¹⁴、Z¹⁵、Z¹⁶、Z¹⁷and Z¹⁸Each independently is N or CR;

each R, R' and R "is independently selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof;

adjacent R substituents may form a fused ring; and is

R 'and R' may form a ring.

In some embodiments, R' and R "form a non-aromatic ring. In some embodiments, the non-aromatic ring is a cycloalkyl ring. In some embodiments, R' and R "form an aromatic ring.

According to another embodiment, a device is also provided that includes one or more organic light emitting devices. At least one of the one or more organic light emitting devices may comprise an anode; a cathode; and an organic layer disposed between the anode and the cathode, wherein the organic layer may comprise a compound of formula I, a compound selected from compounds 1 to 5, or both. The device may be a consumer product, an electronic assembly module, an organic light emitting device and/or a lighting panel.

According to another embodiment, a formulation is provided containing a compound of formula I, a compound selected from compounds 1 to 5, or both.

Drawings

Fig. 1 shows an organic light emitting device.

Fig. 2 shows an inverted organic light-emitting device without a separate electron-transporting layer.

FIG. 3 illustrates the structure of formula I and substituents A, L-B-M and Z as disclosed herein.

Detailed Description

Generally, an OLED comprises at least one organic layer disposed between and electrically connected to an anode and a cathode. When current is applied, the anode injects holes and the cathode injects electrons into the organic layer. The injected holes and electrons each migrate toward the oppositely charged electrode. When an electron and a hole are confined to the same molecule, an "exciton," which is a localized electron-hole pair with an excited energy state, is formed. When the exciton relaxes via a photoemissive mechanism, light is emitted. In some cases, excitons may be confined to an excimer or exciplex. Non-radiative mechanisms (e.g., thermal relaxation) may also occur, but are generally considered undesirable.

The initial OLEDs used emissive molecules that emit light from a singlet state ("fluorescence"), as disclosed, for example, in U.S. patent No. 4,769,292, which is incorporated by reference in its entirety. Fluorescence emission typically occurs in a time frame of less than 10 nanoseconds.

More recently, OLEDs having emissive materials that emit light from the triplet state ("phosphorescence") have been demonstrated. Baldo (Baldo) et al, "efficient phosphorescent Emission from Organic Electroluminescent Devices" (Nature), 395 th volume, 151 th page 154, 1998; ("Baldolo-I") and Bardolo et al, "Very efficient Green organic light-emitting devices based on electro-phosphorescence" (Very high-efficiency green organic light-emitting devices), applied Physics (appl. Phys. Lett.), Vol.75, No. 3, pp.4-6 (1999) ("Baldolo-II"), which are incorporated herein by reference in their entirety. Phosphorescence is described in more detail in U.S. Pat. No. 7,279,704, columns 5-6, which is incorporated by reference.

Fig. 1 shows an organic light emitting device 100. The figures are not necessarily to scale. Device 100 may include substrate 110, anode 115, hole injection layer 120, hole transport layer 125, electron blocking layer 130, emissive layer 135, hole blocking layer 140, electron transport layer 145, electron injection layer 150, protective layer 155, cathode 160, and barrier layer 170. Cathode 160 is a composite cathode having a first conductive layer 162 and a second conductive layer 164. The device 100 may be fabricated by sequentially depositing the described layers. The nature and function of these various layers, as well as the example materials, are described in more detail in columns 6-10 of US 7,279,704, which is incorporated 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. Pat. No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is doped with F at a molar ratio of 50: 1₄TCNQ m-MTDATA as disclosed in U.S. patent application publication No. 2003/0230980, which is incorporated by reference in its entirety. Examples of emissive materials and host materials are disclosed in U.S. patent No. 6,303,238 to Thompson et al, which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1: 1, as disclosed in U.S. patent application publication No. 2003/0230980, which is incorporated by reference in its entirety. U.S. Pat. Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entirety, disclose examples of cathodes including composite cathodes having a thin layer of a metal such as Mg: Ag and an overlying layer of transparent, conductive, sputter-deposited ITO. The principles and use of barrier layers are described in more detail in U.S. patent No. 6,097,147 and U.S. patent application publication No. 2003/0230980, which are incorporated by reference in their entirety. Examples of injection layers are provided in U.S. patent application publication No. 2004/0174116, which is incorporated by reference in its entirety. A description of the protective layer may be found in U.S. patent application publication No. 2004/0174116, which is incorporated by reference in its entirety.

Fig. 2 shows an inverted OLED 200. The device includes a substrate 210, a cathode 215, an emissive layer 220, a hole transport layer 225, and an anode 230. The device 200 may be fabricated by sequentially depositing the described layers. Because the most common OLED configuration has a cathode disposed over an anode, and device 200 has cathode 215 disposed under anode 230, device 200 may be referred to as an "inverted" OLED. In the corresponding layers of the device 200, materials similar to those described with respect to the device 100 may be used. Fig. 2 provides one example of how some layers may be omitted from the structure of device 100.

The simple layered structure illustrated in fig. 1 and 2 is provided as a non-limiting example, and it should be understood that embodiments of the present invention can be used in conjunction with a wide variety of other structures. The specific materials and structures described are exemplary in nature, and other materials and structures may be used. A functional OLED may be realized by combining the described individual layers in different ways, or several layers may be omitted entirely, based on design, performance and cost factors. Other layers not specifically described may also be included. Materials other than those specifically described may be used. Although many of the examples provided herein describe the various layers as comprising a single material, it is understood that combinations of materials (e.g., mixtures of host and dopant) or, more generally, mixtures may be used. Also, the layer may have various sub-layers. The names given to the various layers herein are not intended to be strictly limiting. For example, in device 200, hole transport layer 225 transports holes and injects holes into emissive layer 220, and may be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED may be described as having an "organic layer" disposed between a cathode and an anode. This organic layer may comprise a single layer, or may further comprise multiple layers of different organic materials as described, for example, with respect to fig. 1 and 2.

Structures and materials not specifically described, such as oleds (pleds) comprising polymeric materials, may also be used, such as disclosed in U.S. patent No. 5,247,190 to Friend et al, which is incorporated by reference in its entirety. As another example, an OLED having a single organic layer may be used. The OLEDs may be stacked, for example as described in U.S. Pat. No. 5,707,745 to Forrest (Forrest) et al, which is incorporated by reference in its entirety. The OLED structure can deviate from the simple layered structure illustrated in fig. 1 and 2. For example, the substrate may include an angled reflective surface to improve out-coupling (out-coupling), such as a mesa structure as described in U.S. patent No. 6,091,195 to forrest et al, and/or a pit structure as described in U.S. patent No. 5,834,893 to Bulovic et al, which are incorporated by reference in their entirety.

Any of the layers of the various embodiments may be deposited by any suitable method, unless otherwise specified. For organic layers, preferred methods include thermal evaporation, ink jetting (e.g., as described in U.S. Pat. Nos. 6,013,982 and 6,087,196, both incorporated by reference in their entirety), organic vapor deposition (OVPD) (e.g., as described in U.S. Pat. No. 6,337,102 to Foster et al, both incorporated by reference in their entirety), and deposition by Organic Vapor Jet Printing (OVJP) (e.g., as described in U.S. Pat. No. 7,431,968, incorporated by reference in its entirety). Other suitable deposition methods include spin coating and other solution-based processes. The solution-based process is preferably carried out in a nitrogen or inert atmosphere. For other layers, a preferred method includes thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding (such as described in U.S. patent nos. 6,294,398 and 6,468,819, which are incorporated by reference in their entirety), and patterning associated with some of the deposition methods, such as inkjet and OVJD. Other methods may also be used. The material to be deposited may be modified to be compatible with a particular deposition method. For example, substituents such as alkyl and aryl groups, branched or unbranched, and preferably containing at least 3 carbons, may be used in small molecules to enhance their ability to undergo solution processing. Substituents having 20 carbons or more may be used, and 3 to 20 carbons are a preferred range. A material with an asymmetric structure may have better solution processibility than a material with a symmetric structure, because asymmetric materials may have a lower tendency to recrystallize. Dendrimer substituents may be used to enhance the ability of small molecules to undergo solution processing.

Devices fabricated according to embodiments of the present invention may further optionally include a barrier layer. One purpose of the barrier layer is to protect the electrodes and organic layers from damage due to exposure to harmful substances in the environment, including moisture, vapor, and/or gases, among others. The barrier layer may be deposited on, under or beside the substrate, electrode, or on any other part of the device, including the edges. The barrier layer may comprise a single layer or multiple layers. The barrier layer may be formed by various known chemical vapor deposition techniques and may include compositions having a single phase as well as compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may incorporate inorganic compounds or organic compounds or both. Preferred barrier layers comprise a mixture of polymeric and non-polymeric materials as described in U.S. patent No. 7,968,146, PCT patent application nos. PCT/US2007/023098 and PCT/US2009/042829, which are incorporated herein by reference in their entirety. To be considered a "mixture," the aforementioned polymeric and non-polymeric materials that make up the barrier layer should be deposited under the same reaction conditions and/or at the same time. The weight ratio of polymeric material to non-polymeric material may be in the range of 95: 5 to 5: 95. The polymeric material and the non-polymeric material may be produced from the same precursor material. In one example, the mixture of polymeric material and non-polymeric material consists essentially of polymeric silicon and inorganic silicon.

Devices manufactured according to embodiments of the present invention may be incorporated into a wide variety of electronic component modules (or units), which may be incorporated into a wide variety of electronic products or intermediate components. Examples of such electronic products or intermediate components include display screens, lighting devices (e.g., discrete light source devices or lighting panels), etc., which may be utilized by end-user product manufacturers. The electronics module may optionally include drive electronics and/or a power source. Devices made according to embodiments of the present invention can be incorporated into a wide variety of consumer products having one or more electronic component modules (or units) incorporated therein. The consumer products will include any kind of product that includes one or more light sources and/or one or more visual displays of some type. Some examples of such consumer products include flat panel displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior lighting and/or signaling, heads-up displays, fully or partially transparent displays, flexible displays, laser printers, telephones, cell phones, tablet computers, tablet phones, Personal Digital Assistants (PDAs), laptop computers, digital cameras, camcorders, viewfinders, micro-displays, 3-D displays, vehicles, large area walls, theater or stadium screens, or signs. Various control mechanisms may be used to control devices made in accordance with the present invention, including passive matrices and active matrices. Many of the devices are intended to be used in a temperature range that is comfortable for humans, such as 18 degrees celsius to 30 degrees celsius, and more preferably at room temperature (20-25 degrees celsius), but may be used outside this temperature range (e.g., -40 degrees celsius to +80 degrees celsius).

The materials and structures described herein may be applied in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors may use the materials and structures. More generally, organic devices such as organic transistors may use the materials and structures.

As used herein, the terms "halo", "halogen" or "halide" include fluorine, chlorine, bromine and iodine.

As used herein, the term "alkyl" encompasses both straight-chain and branched-chain alkyl groups. Preferred alkyl groups are those containing one to fifteen carbon atoms and include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, and the like. In addition, the alkyl group may be optionally substituted.

As used herein, the term "cycloalkyl" encompasses cyclic alkyl groups. Preferred cycloalkyl groups are those containing 3 to 7 carbon atoms and include cyclopropyl, cyclopentyl, cyclohexyl, and the like. In addition, cycloalkyl groups may be optionally substituted.

As used herein, the term "alkenyl" encompasses straight and branched chain alkenyl groups. Preferred alkenyl groups are those containing from two to fifteen carbon atoms. In addition, the alkenyl group may be optionally substituted.

As used herein, the term "alkynyl" encompasses straight and branched chain alkynyl groups. Preferred alkynyl groups are those containing from two to fifteen carbon atoms. In addition, the alkynyl group may be optionally substituted.

As used herein, the terms "aralkyl" or "arylalkyl" are used interchangeably and encompass alkyl groups having an aromatic group as a substituent. In addition, the aralkyl group may be optionally substituted.

As used herein, the term "heterocyclyl" encompasses aromatic and non-aromatic cyclic groups. Heteroaromatic cyclic groups are also intended to mean heteroaryl groups. Preferred non-aromatic heterocyclic groups are heterocyclic groups containing 3 or 7 ring atoms including at least one heteroatom and include cyclic amines such as morpholinyl, piperidinyl, pyrrolidinyl, and the like, and cyclic ethers such as tetrahydrofuran, tetrahydropyran, and the like. In addition, the heterocyclic group may be optionally substituted.

As used herein, the term "aryl" or "aromatic group" encompasses monocyclic groups and polycyclic ring systems. A polycyclic ring can have two or more rings in which two carbons are common to two adjoining rings (the rings are "fused"), wherein at least one of the rings is aromatic, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryls, heterocyclics, and/or heteroaryls. In addition, the aryl group may be optionally substituted.

As used herein, the term "heteroaryl" encompasses monocyclic heteroaromatic groups that may include one to three heteroatoms, such as pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, pyrazole, pyridine, pyrazine, pyrimidine and the like. The term heteroaryl also includes polycyclic heteroaromatic systems having two or more rings in which two atoms are common to two adjoining rings (the rings are "fused"), wherein at least one of the rings is heteroaryl, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryls, heterocycles and/or heteroaryls. In addition, heteroaryl groups may be optionally substituted.

The alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, heterocyclyl, aryl, and heteroaryl groups may be optionally substituted with one or more substituents selected from the group consisting of: hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, cyclic amino, silane, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof.

As used herein, "substituted" means that a substituent other than H is bonded to the relevant position, e.g., carbon. Thus, for example, at R¹When mono-substituted, then an R¹Must not be H. Similarly, at R¹When disubstituted, then two R¹Must not be H. Similarly, at R¹When unsubstituted, R¹Hydrogen for all available locations.

The designation "aza" in the fragments described herein (i.e., aza-dibenzofuran, aza-dibenzothiophene, etc.) means that one or more C-H groups in the respective fragment may be replaced by a nitrogen atom, for example and without any limitation, azatriphenylene encompasses dibenzo [ f, H ] quinoxaline and dibenzo [ f, H ] quinoline. Other nitrogen analogs of the aza-derivatives described above can be readily envisioned by one of ordinary skill in the art, and all such analogs are intended to be encompassed by the term as set forth herein.

It is understood that when a molecular fragment is described as a substituent or otherwise attached to another moiety, its name can be written as if it were a fragment (e.g., phenyl, phenylene, naphthyl, dibenzofuranyl) or as if it were an entire molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, these different ways of naming substituents or connecting fragments are considered to be equivalent.

According to one embodiment, a compound is described having the structure of formula I:

A-L-B-M-D，

in the structure of formula I:

a is selected from the group consisting of:

l is a linking group selected from the group consisting of: a single bond, aryl having 6 to 30 carbon atoms, heteroaryl having 3 to 30 carbon atoms, and combinations thereof;

when L is aryl or heteroaryl, L is optionally further substituted by one or more groups selected from: hydrogen, deuterium, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, and combinations thereof;

L-B-M has the following structure:

wherein M is selected from the group consisting of: aryl having 6 to 30 carbon atoms, heteroaryl having 3 to 30 carbon atoms, and combinations thereof;

m is optionally further substituted with one or more groups selected from: hydrogen, deuterium, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, and combinations thereof;

d has the following structure:

x is selected from the group consisting of: o, S, Se and CR 'R';

X¹、X²、X³、X⁴、X⁵、X⁶、X⁷、X⁸、Y¹、Y²、Y³、Y⁴、Y⁵、Y⁶、Y⁷、Y⁸、Y⁹、Y¹⁰、Y¹¹、Y¹²、Z¹、Z³、Z⁴、Z⁵、Z⁶、Z⁷、Z⁸、Z¹¹、Z¹²、Z¹³、Z¹⁴、Z¹⁵、Z¹⁶、Z¹⁷and Z¹⁸Each independently is N or CR;

each R, R' and R "is independently selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof;

adjacent R substituents may form a fused ring; and is

R 'and R' may form a ring.

In some embodiments, R' and R "form a non-aromatic ring. In some embodiments, the non-aromatic ring is a cycloalkyl ring. In some embodiments, R' and R "form an aromatic ring.

In some embodiments, X is S.

In some embodiments, X¹To X⁸Is N. In some embodiments, X¹-X⁸Is N. In some embodiments, X¹-X⁴Is N, and X⁵-X⁸Is C. In some embodiments, X⁵-X⁸Is N, and X¹-X⁴Is C.

In some embodiments, Y¹To Y¹²Is N. In some embodiments, Y¹-Y¹²Is N. In some embodiments, Y⁵-Y¹²Is N. In some embodiments, Y⁵-Y⁸Is N. In some embodiments, Y⁵-Y⁸Is N, Y⁸-Y¹²Is C. In some embodiments, Y¹-Y⁴Is C.

In some embodiments, Z¹、Z³、Z⁴、Z⁵、Z⁶、Z⁷And Z⁸Is N. In some embodiments, Z¹、Z³、Z⁴、Z⁵、Z⁶、Z⁷And Z⁸Is N. In some embodiments, Z¹、Z³And Z⁴Is N, and Z⁵、Z⁶、Z⁷And Z⁸Is C. In some embodiments, Z⁵、Z⁶、Z⁷And Z⁸Is N, and Z¹、Z³、Z⁴Is C.

In some embodiments, Z¹¹To Z¹⁸Is N. In some embodiments, Z¹¹-Z¹⁸Is N. In some embodiments, Z¹¹-Z¹⁴Is N, and Z¹⁵-Z¹⁸Is C.

In some embodiments, a is selected from the group consisting of:

in some embodiments, L is selected from the group consisting of:

a single bond (L1),

In some embodiments, B is selected from the group consisting of:

in some embodiments, M is selected from the group consisting of:

in some embodiments, D is selected from the group consisting of:

in some embodiments, the compound is selected from the group consisting of:

in other embodiments, a compound selected from compounds 1 to 5 is disclosed.

According to another aspect of the present invention, there is also provided a device comprising one or more organic light emitting devices. At least one of the one or more organic light emitting devices may comprise an anode; a cathode; and an organic layer disposed between the anode and the cathode. The organic layer may include one or more emitter dopants. The emitter dopant may be a phosphorescent dopant and/or a fluorescent dopant. The organic layer may comprise as a host a compound according to formula I and variants thereof as described herein. Alternatively or additionally, the organic layer may include a compound selected from the group consisting of: compounds 1 to 5 as described herein.

The apparatus may be one or more of: consumer products, electronic component modules, organic light emitting devices, and lighting panels.

In some embodiments, the organic layer is an emissive layer and the compound of formula I or a compound selected from compounds 1 to 5 is the host.

In some embodiments, the organic layer further comprises a phosphorescent emissive dopant, wherein the phosphorescent emissive dopant is a transition metal complex having at least one ligand or a portion of the ligand when the ligand is more than bidentate, the ligand selected from the group consisting of:

wherein R is_a、R_b、R_cAnd R_dMay represent a mono-, di-, tri-or tetra-substituent or no substituent;

wherein R is_a、R_b、R_cAnd R_dIndependently selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof; and is

Wherein R is_a、R_b、R_cAnd R_dOptionally joined to form a fused ring or to form a multidentate ligand.

In some embodiments, the organic layer is a barrier layer and the compound of formula I is a barrier material in the organic layer. In some embodiments, the organic layer is an electron transporting layer and the compound having formula I is an electron transporting material in the organic layer.

In another aspect of the invention, a formulation is described comprising a compound according to formula I disclosed herein and variants thereof. Also described is a formulation comprising a compound selected from compound 1 to compound 5. The formulation may include one or more of the components disclosed herein selected from the group consisting of: a solvent, a host, a hole injection material, a hole transport material, and an electron transport layer material.

In combination with other materials

Materials described herein as useful for particular layers in an organic light emitting device can be used in combination with a variety of other materials present in the device. For example, the emissive dopants disclosed herein may be used in conjunction with a variety of hosts, transport layers, barrier layers, implant layers, electrodes, and other layers that may be present. The materials described or referenced below are non-limiting examples of materials that can 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 can be used in combination.

HIL/HTL：

The hole injecting/transporting material used in the present invention is not particularly limited, and any compound may be used as long as the compound is typically used as the hole injecting/transporting material. Examples of such materials include (but are not limited to): phthalocyanine or porphyrin derivatives; an aromatic amine derivative; indolocarbazole derivatives; a fluorocarbon-containing polymer; a polymer having a conductive dopant; conductive polymers such as PEDOT/PSS; self-assembling monomers derived from compounds such as phosphonic acids and silane derivatives; metal oxide derivatives, e.g. MoO_x(ii) a p-type semiconductor organic compounds such as 1, 4, 5,8, 9, 12-hexaazatriphenylhexacyano nitrile; a metal complex, and a crosslinkable compound.

Examples of aromatic amine derivatives used in the HIL or HTL include (but are not limited to) the following general structures:

Ar¹to Ar⁹Each of which is selected from the group consisting of aromatic hydrocarbon ring compounds, such as benzene, biphenyl, terphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chicory, perylene, azulene; groups composed of aromatic heterocyclic compounds, such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolobipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazines, oxadiazines, indoles, benzimidazoles, indazoles, indoxazines, benzoxazoles, benzisoxazoles, benzothiazoles, quinolines, isoquinolines, cinnolines, quinazolines, quinoxalines, naphthyridines, phthalazines, pteridines, dibenzopyrans, acridines, phenazines, phenothiazines, phenoxazines, benzofuropyridines, furobipyridines, benzothienopyridines, thienobipyridines, benzoselenenopyridines, and selenophenodipyridines; and a group consisting of 2 to 10 cyclic structural units which are the same type or different types of groups selected from aromatic hydrocarbon ring groups and aromatic heterocyclic groups and are bonded to each other directly or via at least one of an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, a phosphorus atom, a boron atom, a chain structural unit and an aliphatic ring group. Wherein each Ar is further substituted with a substituent selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, Ar¹To Ar⁹Independently selected from the group consisting of:

wherein k is an integer from 1 to 20; x¹⁰¹To X¹⁰⁸Is C (including CH) or N; z¹⁰¹Is NAr¹O or S; ar (Ar)¹Having the same groups as defined above.

Examples of metal complexes used in HILs or HTLs include, but are not limited to, the following general formulas:

wherein Met is a metal, which may have an atomic weight greater than 40; (Y)¹⁰¹-Y¹⁰²) Is a bidentate ligand, Y¹⁰¹And Y¹⁰²Independently selected from C, N, O, P and S; l is¹⁰¹Is an ancillary ligand; k' is an integer value from 1 to the maximum number of ligands that can be attached to the metal; and k' + k "is the maximum number of ligands that can be attached to the metal.

In one aspect, (Y)¹⁰¹-Y¹⁰²) Is a 2-phenylpyridine derivative. In another aspect, (Y)¹⁰¹-Y¹⁰²) Are carbene ligands. In another aspect, Met is selected from Ir, Pt, Os and Zn. In another aspect, the metal complex has a relative Fc of less than about 0.6V⁺Solution minimum oxidation potential of the/Fc pair.

A main body:

the light-emitting layer of the organic EL device of the present invention preferably contains at least a metal complex as a light-emitting material, and may contain a host material using the metal complex as a dopant material. Examples of the host material are not particularly limited, and any metal complex or organic compound may be used as long as the triplet energy of the host is larger than that of the dopant. Although the following table classifies host materials as preferred for devices emitting various colors, any host material and any dopant may be used as long as the triplet criteria are met.

Examples of the metal complex used as the host preferably have the following general formula:

wherein Met is a metal; (Y)¹⁰³-Y¹⁰⁴) Is a bidentate ligand, Y¹⁰³And Y¹⁰⁴Independently selected from C, N, O, P and S; l is¹⁰¹Is another ligand; k' is an integer value from 1 to the maximum number of ligands that can be attached to the metal; and k' + k "is the maximum number of ligands that can be attached to the metal.

In one aspect, the metal complex is:

wherein (O-N) is a bidentate ligand having a metal coordinated to the O and N atoms.

In another aspect, Met is selected from Ir and Pt. In another aspect, (Y)¹⁰³-Y¹⁰⁴) Are carbene ligands.

Examples of the organic compound used as the host are selected from the group consisting of aromatic hydrocarbon ring compounds such as benzene, biphenyl, terphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chicory, perylene, azulene; groups composed of aromatic heterocyclic compounds, such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolobipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazines, oxadiazines, indoles, benzimidazoles, indazoles, indoxazines, benzoxazoles, benzisoxazoles, benzothiazoles, quinolines, isoquinolines, cinnolines, quinazolines, quinoxalines, naphthyridines, phthalazines, pteridines, dibenzopyrans, acridines, phenazines, phenothiazines, phenoxazines, benzofuropyridines, furobipyridines, benzothienopyridines, thienobipyridines, benzoselenenopyridines, and selenophenodipyridines; and a group consisting of 2 to 10 cyclic structural units which are the same type or different types of groups selected from aromatic hydrocarbon ring groups and aromatic heterocyclic groups and are bonded to each other directly or via at least one of an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, a phosphorus atom, a boron atom, a chain structural unit and an aliphatic ring group. Wherein each group is further substituted with a substituent selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, the host compound contains in the molecule at least one of the following groups:

wherein R is¹⁰¹To R¹⁰⁷Independently selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof, which when aryl or heteroaryl has a similar definition to Ar above. k is an integer from 0 to 20 or 1 to 20; k' ″ is an integer of 0 to 20. X¹⁰¹To X¹⁰⁸Selected from C (including CH) or N. Z¹⁰¹And Z¹⁰²Selected from NR¹⁰¹O or S.

HBL：

Hole Blocking Layers (HBLs) may be used to reduce the number of holes and/or excitons that leave the emissive layer. The presence of such a barrier layer in the device may result in substantially higher efficiency compared to a similar device lacking the barrier layer. Furthermore, the blocking layer can be used to limit the emission to a desired area of the OLED.

In one aspect, the compounds used in the HBL contain the same molecule or the same functional group used as the host described above.

In another aspect, the compound used in HBL contains in the molecule at least one of the following groups:

wherein k is an integer from 1 to 20; l is¹⁰¹Is another ligand, and k' is an integer of 1 to 3.

ETL：

The Electron Transport Layer (ETL) may include a material capable of transporting electrons. The electron transport layer may be intrinsic (undoped) or doped. Doping may be used to enhance conductivity. Examples of the ETL material are not particularly limited, and any metal complex or organic compound may be used as long as it is typically used to transport electrons.

In one aspect, the compound used in the ETL contains in the molecule at least one of the following groups:

wherein R is¹⁰¹Selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof, which when aryl or heteroaryl has a similar definition to Ar above. Ar (Ar)¹To Ar³Have similar definitions as Ar described above. k is an integer of 1 to 20. X¹⁰¹To X¹⁰⁸Selected from C (including CH) or N.

In another aspect, the metal complexes used in the ETL include, but are not limited to, those of the general formula:

wherein (O-N) or (N-N) is a group having a coordination with atom O, N or N, NBidentate ligands of the metal of the site; l is¹⁰¹Is another ligand; k' is an integer value from 1 to the maximum number of ligands that can be attached to the metal.

In any of the above compounds used in each layer of an OLED device, the hydrogen atoms may be partially or fully deuterated. Thus, any specifically listed substituent (such as, but not limited to, methyl, phenyl, pyridyl, etc.) encompasses non-deuterated, partially deuterated, and fully deuterated forms thereof. Similarly, substituent classes (such as, but not limited to, alkyl, aryl, cycloalkyl, heteroaryl, etc.) also encompass non-deuterated, partially deuterated, and fully deuterated forms thereof.

Many hole injection materials, hole transport materials, host materials, dopant materials, exciton/hole blocking layer materials, electron transport materials, and electron injection materials can be used in OLEDs in addition to and/or in combination with the materials disclosed herein. Non-limiting examples of materials that can be used in OLEDs in combination with the materials disclosed herein are listed in table a below. Table a lists non-limiting classes of materials, non-limiting examples of compounds of each class, and references disclosing the materials.

TABLE A

Experiment of

Synthesis examples

Synthesis of Compound A1-L1-B1-M2-D1

2- (3- (9H-carbazol-9-yl) phenyl) -9H-carbazole (3.50g, 8.57mmol), 2-bromodibenzo [ b, d ] is added]Thiophene (2.255g, 8.57mm0l), tris (dibenzylideneacetone) dipalladium (0) (0.157g, 0.171mmol), dicyclohexyl (2 ', 6 ' -dimethoxy- [1, 1 ' -biphenyl)]A solution of-2-yl) phosphine (0.211g, 0.514mmol) and sodium 2-methylpropan-2-oate (1.647g, 17.14mmol) in xylene (100mL) was refluxed under nitrogen for 16 hours. Passing the hot reaction mixture through a short tube

The plug was filtered and then the solvent was evaporated. The crude material was purified by column chromatography on silica gel with heptane/DCM (1/1, v/v) as eluent and then recrystallized from toluene/ethanol to give compound a1-L1-B1-M2-D1 as a white solid (2.1g, 42%).

Synthesis of Compound A4-L1-B1-M2-D1

2- (3- (9H-carbazol-9-yl) phenyl) -9H-carbazole (3.50g, 8.57mmol), 2-bromotriphenylene (3.16g, 10.28mmol), tris (diphenylmethyleneacetone) dipalladium (0) (0.157g, 0.171mmol), dicyclohexyl (2 ', 6 ' -dimethoxy- [1, 1 ' -biphenyl)]A solution of-2-yl) phosphine (0.211g, 0.514mmol) and sodium 2-methylpropan-2-oate (1.647g, 17.14mmol) in xylene (150mL) was refluxed under nitrogen for 16 hours. Passing the hot reaction mixture through a short tube

The plug was filtered and then the solvent was evaporated. The crude material was purified by column chromatography on silica gel with heptane/dichloromethane (1/1, v/v) as eluent, and then recrystallized from heptane/dichloromethane to give compound a4-L1-B1-M2-D1 as a white solid (3.5g, 64%).

Synthesis of Compound 5

3- (3- (9H-carbazol-9-yl) phenyl) -9H-carbazole (7g, 17.14mmol), 2-bromotriphenylene (4.74g, 15.42mmol), sodium 2-methylpropane-2-ate (3.29g, 34.3mmol), tris (diphenylmethyleneacetone) dipalladium (0) (0.235g, 0.257mmol) and dicyclohexyl (2 ', 6 ' -dimethoxy- [1, 1 ' -biphenyl)]A solution of-2-yl) phosphine (0.211g, 0.514mmol) in xylene (120ml) was refluxed under nitrogen for 16 hours. Passing the hot reaction mixture through a short tube

The plug was filtered and then the solvent was evaporated. The crude material was purified by column chromatography on silica gel with heptane/dichloromethane (1/1, v/v) as eluent and then recrystallized from toluene/ethanol to give compound 5(5.1g, 47%) as a white solid.

Example of the device

All OLED devices passed through a high vacuum (about 10)^-7Torr) thermal evaporation. The anode electrode was 80nm Indium Tin Oxide (ITO). The cathode electrode consisted of 1nm LiF followed by 100nm Al. After manufacture, all devices were immediately encapsulated with epoxy-sealed glass lids in a nitrogen glove box (< 1ppm H)₂O and O₂) And incorporating a moisture getter into the package interior.

Device 1. a first device has an organic stack consisting of, in order from the ITO surface: 10nm of LG101 (from LG Chem) as Hole Injection Layer (HIL), 30nm of 4, 4' -bis [ N- (1-naphthyl) -N-phenylaminobiphenyl (NPD) as Hole Transport Layer (HTL), and 30nm of emission layer (EML). On top of the EML, 5nm of compound BL was deposited as a Hole Blocking Layer (HBL), followed by 45nm of tris (8-hydroxyquinolinyl) aluminum (Alq)₃) As an Electron Transport Layer (ETL). EML consists of two components: 90% by weight of A1-L1-B1-M2-D1 was used as the host, and 10% by weight of GD was used as the emissive dopant. The chemical structures of the compounds used are shown below.

Device 2. device 2 has the same structure as device 1 except that compound a4-L1-B1-M2-D1 was used as the host.

Device 3 has the same structure as device 1 except that compound 5 is used as the host.

Device C-1 has the same structure as device 1, except that compound CC-1 is used as the host.

Table 1 below is a summary of the device data. The External Quantum Efficiency (EQE) is recorded at 1000 nits, and is defined as the Lifetime (LT) of the device required to decay to 80% of the 1000 nits initial brightness₈₀) By assuming that the acceleration factor is 1.8 at 40mA/cm²The value measured at constant current density was calculated. The lifetime data is normalized to the lifetime data of the device 1.

All devices emit a green color. As shown in Table 1, devices 1, 2 and 3 using the compounds of the present invention as host materials exhibited higher efficiencies and longer lifetimes as compared to device C-1 using comparative compound CC-1 as host material. This suggests that the linking group (e.g., benzene) between the two carbazole moieties plays a key role in enhancing the material properties of the host compounds of the present invention. One possible explanation is that the improvement results from a more balanced electron/hole flux due to the unique chemical structure of the compounds of the present invention.

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. For example, many of the materials and structures described herein may be substituted with other materials and structures without departing from the spirit of the invention. The invention as claimed may thus include variations from the specific examples and preferred embodiments described herein, as will be apparent to those skilled in the art. It should be understood that various theories as to why the invention works are not intended to be limiting.

Claims (15)

1. A compound having the structure of formula I:

A-L-B-M-D，

wherein A is selected from the group consisting of:

wherein L is a linking group selected from the group consisting of: a single bond, aryl having 6 to 30 carbon atoms, heteroaryl having 3 to 30 carbon atoms, and combinations thereof;

wherein, when L is aryl or heteroaryl, L is optionally further substituted by one or more groups selected from: hydrogen, deuterium, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, and combinations thereof;

wherein L-B-M has the following structure:

wherein M is selected from the group consisting of: aryl having 6 to 30 carbon atoms, heteroaryl having 3 to 30 carbon atoms, and combinations thereof;

wherein M is optionally further substituted with one or more groups selected from: hydrogen, deuterium, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, and combinations thereof;

wherein D has the following structure:

wherein X is selected from the group consisting of: o, S, Se and CR 'R';

wherein X¹、X²、X³、X⁴、X⁵、X⁶、X⁷、X⁸、Y¹、Y²、Y³、Y⁴、Y⁵、Y⁶、Y⁷、Y⁸、Y⁹、Y¹⁰、Y¹¹、Y¹²、Z¹、Z³、Z⁴、Z⁵、Z⁶、Z⁷、Z⁸、Z¹¹、Z¹²、Z¹³、Z¹⁴、Z¹⁵、Z¹⁶、Z¹⁷And Z¹⁸Each independently is N or CR；

Wherein each of R, R' and R "is independently selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein adjacent R substituents may form a fused ring; and is

Wherein R 'and R' may form a ring.

2. The compound of claim 1, wherein X is S.

3. The compound of claim 1, wherein X¹To X⁸Is N.

4. The compound of claim 1, wherein Z¹、Z³、Z⁴、Z⁵、Z⁶、Z⁷And Z⁸Is N.

5. The compound of claim 1, wherein a is selected from the group consisting of:

6. the compound of claim 1, wherein L is selected from the group consisting of:

a single bond (L1),

7. The compound of claim 1, wherein B is selected from the group consisting of:

8. the compound of claim 1, wherein M is selected from the group consisting of:

9. the compound of claim 1, wherein D is selected from the group consisting of:

10. the compound of claim 1, wherein the compound is selected from the group consisting of:

11. a compound selected from the group consisting of:

12. a device comprising one or more organic light emitting devices, at least one of the one or more organic light emitting devices comprising:

an anode;

a cathode; and

an organic layer disposed between the anode and the cathode comprising a compound having the structure of formula I:

A-L-B-M-D，

wherein A is selected from the group consisting of:

wherein L is a linking group selected from the group consisting of: a single bond, aryl having 6 to 30 carbon atoms, heteroaryl having 3 to 30 carbon atoms, and combinations thereof;

wherein, when L is aryl or heteroaryl, L is optionally further substituted by one or more groups selected from: hydrogen, deuterium, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, and combinations thereof;

wherein L-B-M has the following structure:

wherein M is selected from the group consisting of: aryl having 6 to 30 carbon atoms, heteroaryl having 3 to 30 carbon atoms, and combinations thereof;

wherein M is optionally further substituted with one or more groups selected from: hydrogen, deuterium, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, and combinations thereof;

wherein D has the following structure:

wherein X is selected from the group consisting of: o, S, Se and CR 'R';

wherein X¹、X²、X³、X⁴、X⁵、X⁶、X⁷、X⁸、Y¹、Y²、Y³、Y⁴、Y⁵、Y⁶、Y⁷、Y⁸、Y⁹、Y¹⁰、Y¹¹、Y¹²、Z¹、Z³、Z⁴、Z⁵、Z⁶、Z⁷、Z⁸、Z¹¹、Z¹²、Z¹³、Z¹⁴、Z¹⁵、Z¹⁶、Z¹⁷And Z¹⁸Each independently is N or CR;

wherein each of R, R' and R "is independently selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof; and is

Wherein adjacent R substituents may form a fused ring; and is

Wherein R 'and R' may form a ring.

13. The device of claim 12, wherein the organic layer is an emissive layer and the compound of formula I is a host.

14. The device of claim 12, further comprising a phosphorescent emissive dopant, wherein the phosphorescent emissive dopant is a transition metal complex having at least one ligand or a portion of the ligand when more than bidentate, the ligand selected from the group consisting of:

wherein R is_a、R_b、R_cAnd R_dMay represent a mono-, di-, tri-or tetra-substituent or no substituent;

wherein R is_a、R_b、R_cAnd R_dIndependently selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof; and is

Wherein R is_a、R_b、R_cAnd R_dOptionally joined to form a fused ring or to form a multidentate ligand.

15. A formulation comprising a compound having the structure of formula I:

A-L-B-M-D，

wherein A is selected from the group consisting of:

wherein L is a linking group selected from the group consisting of: a single bond, aryl having 6 to 30 carbon atoms, heteroaryl having 3 to 30 carbon atoms, and combinations thereof;

wherein, when L is aryl or heteroaryl, L is optionally further substituted by one or more groups selected from: hydrogen, deuterium, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, and combinations thereof;

wherein L-B-M has the following structure:

wherein M is selected from the group consisting of: aryl having 6 to 30 carbon atoms, heteroaryl having 3 to 30 carbon atoms, and combinations thereof;

wherein M is optionally further substituted with one or more groups selected from: hydrogen, deuterium, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, and combinations thereof;

wherein D has the following structure:

wherein X is selected from the group consisting of: o, S, Se and CR 'R';

wherein X¹、X²、X³、X⁴、X⁵、X⁶、X⁷、X⁸、Y¹、Y²、Y³、Y⁴、Y⁵、Y⁶、Y⁷、Y⁸、Y⁹、Y¹⁰、Y¹¹、Y¹²、Z¹、Z³、Z⁴、Z⁵、Z⁶、Z⁷、Z⁸、Z¹¹、Z¹²、Z¹³、Z¹⁴、Z¹⁵、Z¹⁶、Z¹⁷And Z¹⁸Each independently is N or CR;

wherein each of R, R' and R "is independently selected from the group consisting of: hydrogen, deuterium, halo, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof; and is

Wherein adjacent R substituents may form a fused ring; and is

Wherein R 'and R' may form a ring.

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