Patent Grant
11910708
The present invention relates to compounds for use as emitters, and devices, such as organic light emitting diodes, including the same.
Opto-electronic devices that make use of organic materials are becoming increasingly desirable for a number of reasons. Many of the materials used to make such devices are relatively inexpensive, so organic opto-electronic devices have the potential for cost advantages over inorganic devices. In addition, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications such as fabrication on a flexible substrate. Examples of organic opto-electronic devices include organic light emitting diodes/devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, the organic materials may have performance advantages over conventional materials. For example, the wavelength at which an organic emissive layer emits light may generally be readily tuned with appropriate dopants.
OLEDs make use of thin organic films that emit light when voltage is applied across the device. OLEDs are becoming an increasingly interesting technology for use in applications such as flat panel displays, illumination, and backlighting. Several OLED materials and configurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety.
One application for phosphorescent emissive molecules is a full color display. Industry standards for such a display call for pixels adapted to emit particular colors, referred to as “saturated” colors. In particular, these standards call for saturated red, green, and blue pixels. Alternatively the OLED can be designed to emit white light. In conventional liquid crystal displays emission from a white backlight is filtered using absorption filters to produce red, green and blue emission. The same technique can also be used with OLEDs. The white OLED can be either a single EML device or a stack structure. Color may be measured using CIE coordinates, which are well known to the art.
One example of a green emissive molecule is tris(2-phenylpyridine) iridium, denoted Ir(ppy)3, which has the following structure:
In this, and later figures herein, we depict the dative bond from nitrogen to metal (here, Ir) 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 opto-electronic devices. “Small molecule” refers to any organic material that is not a polymer, and “small molecules” may actually be quite large. Small molecules may include repeat units in some circumstances. For example, using a long chain alkyl group as a substituent does not remove a molecule from the “small molecule” class. Small molecules may also be incorporated into polymers, for example as a pendent group on a polymer backbone or as a part of the backbone. Small molecules may 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 a dendrimer may be a fluorescent or phosphorescent small molecule emitter. A dendrimer may be a “small molecule,” and it is believed that all dendrimers currently used in the field of OLEDs are small molecules.
As used herein, “top” means furthest away from the substrate, while “bottom” means closest to the substrate. Where a first layer is described as “disposed over” a second layer, the first layer is disposed further away from substrate. There may be other layers between the first and second layer, unless it is specified that the first layer is “in contact with” the second layer. For example, a cathode may be described as “disposed over” an anode, even though there are various organic layers in between.
As used herein, “solution processable” means capable of being dissolved, dispersed, or transported in and/or deposited from a liquid medium, either in solution or suspension form.
A ligand may be referred to as “photoactive” when it is believed that the ligand directly contributes to the photoactive properties of an 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 an emissive material, although an ancillary ligand may alter the properties of a photoactive ligand.
As used herein, and as would be generally understood by one 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 potentials (IP) are measured as a negative energy relative to a vacuum level, a higher HOMO energy level corresponds to an IP having a smaller absolute value (an IP that is less negative). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) having a smaller absolute value (an EA that is less negative). On a conventional energy level diagram, with the vacuum level at the top, the LUMO energy level of a material is higher than the HOMO energy level of the same material. A “higher” HOMO or LUMO energy level appears closer to the top of such a diagram than a “lower” HOMO or LUMO energy level.
As used herein, and as would be generally understood by one 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. Because work functions are generally measured as negative numbers relative to vacuum level, this means that a “higher” work function is more negative. On a conventional energy level diagram, with the vacuum level at the top, a “higher” work function is illustrated as further away from the vacuum level in the downward direction. Thus, the definitions of HOMO and LUMO energy levels follow a different convention than work functions.
More details on OLEDs, and the definitions described above, can be found in U.S. Pat. No. 7,279,704, which is incorporated herein by reference in its entirety.
According to an aspect of the present disclosure, a compound comprising a first ligand LA is disclosed, where LA is selected from the group consisting of:
wherein,
A is a 5- or 6-membered aromatic ring;
Y1 to Y9 are each independently selected from the group consisting of C and N; wherein Z is C or N;
RA, RB, RC, and RD represent mono to a maximum possible number of substitutions, or no substitution;
each RA, RB, RC, and RD is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;
any two RA substituents can be joined or fused together to form a ring;
LA is complexed to a metal M to form a five-membered chelate ring;
M is optionally coordinated to other ligands; and
the ligand LA is optionally linked with other ligands to form a ligand having a denticity of tridentate to a maximum possible number of denticity to which M can coordinate.
An OLED comprising the compound of the present disclosure in an organic layer therein is also disclosed.
A consumer product comprising the OLED is also disclosed.
Generally, an OLED comprises at least one organic layer disposed between and electrically connected to an anode and a cathode. When a current is applied, the anode injects holes and the cathode injects electrons into the organic layer(s). The injected holes and electrons each migrate toward the oppositely charged electrode. When an electron and hole localize on the same molecule, an “exciton,” which is a localized electron-hole pair having an excited energy state, is formed. Light is emitted when the exciton relaxes via a photoemissive mechanism. In some cases, the exciton may be localized on an excimer or an exciplex. Non-radiative mechanisms, such as thermal relaxation, may also occur, but are generally considered undesirable.
The initial OLEDs used emissive molecules that emitted light from their singlet states (“fluorescence”) as disclosed, for example, in U.S. Pat. No. 4,769,292, which is incorporated by reference in its entirety. Fluorescent emission generally occurs in a time frame of less than 10 nanoseconds.
More recently, OLEDs having emissive materials that emit light from triplet states (“phosphorescence”) have been demonstrated. Baldo et al., “Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices,” Nature, vol. 395, 151-154, 1998; (“Baldo-I”) and Baldo et al., “Very high-efficiency green organic light-emitting devices based on electrophosphorescence,” Appl. Phys. Lett., vol. 75, No. 3, 4-6 (1999) (“Baldo-II”), are incorporated by reference in their entireties. Phosphorescence is described in more detail in U.S. Pat. No. 7,279,704 at cols. 5-6, which are incorporated by reference.
More examples for each of these layers are available. 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 m-MTDATA doped with F4-TCNQ at a molar ratio of 50:1, as disclosed in U.S. Patent Application Publication No. 2003/0230980, which is incorporated by reference in its entirety. Examples of emissive and 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 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 entireties, disclose examples of cathodes including compound cathodes having a thin layer of metal such as Mg:Ag with an overlying transparent, electrically-conductive, sputter-deposited ITO layer. The theory and use of blocking layers is described in more detail in U.S. Pat. No. 6,097,147 and U.S. Patent Application Publication No. 2003/0230980, which are incorporated by reference in their entireties. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004/0174116, which is incorporated by reference in its entirety. A description of protective layers may be found in U.S. Patent Application Publication No. 2004/0174116, which is incorporated by reference in its entirety.
The simple layered structure illustrated in
Structures and materials not specifically described may also be used, such as OLEDs comprised of polymeric materials (PLEDs) such as disclosed in U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of further example, OLEDs having a single organic layer may be used. OLEDs may be stacked, for example as described in U.S. Pat. No. 5,707,745 to Forrest et al, which is incorporated by reference in its entirety. The OLED structure may deviate from the simple layered structure illustrated in
Unless otherwise specified, any of the layers of the various embodiments may be deposited by any suitable method. For the organic layers, preferred methods include thermal evaporation, ink-jet, such as described in U.S. Pat. Nos. 6,013,982 and 6,087,196, which are incorporated by reference in their entireties, organic vapor phase deposition (OVPD), such as described in U.S. Pat. No. 6,337,102 to Forrest et al., which is incorporated by reference in its entirety, and deposition by organic vapor jet printing (OVJP), such as described in U.S. Pat. No. 7,431,968, which is incorporated by reference in its entirety. Other suitable deposition methods include spin coating and other solution based processes. Solution based processes are preferably carried out in nitrogen or an inert atmosphere. For the other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding such as described in U.S. Pat. Nos. 6,294,398 and 6,468,819, which are incorporated by reference in their entireties, and patterning associated with some of the deposition methods such as ink-jet and organic vapor jet printing (OVJP). Other methods may also be used. The materials to be deposited may be modified to make them 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 3-20 carbons is a preferred range. Materials with asymmetric structures may have better solution processability than those having symmetric structures, 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 in accordance with embodiments of the present invention may further optionally comprise a barrier layer. One purpose of the barrier layer is to protect the electrodes and organic layers from damaging exposure to harmful species in the environment including moisture, vapor and/or gases, etc. The barrier layer may be deposited over, under or next to a substrate, an electrode, or over any other parts of a device including an edge. 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 an inorganic or an organic compound or both. The preferred barrier layer comprises a mixture of a polymeric material and a non-polymeric material as described in U.S. Pat. No. 7,968,146, PCT Pat. Application Nos. PCT/US2007/023098 and PCT/US2009/042829, which are herein incorporated by reference in their entireties. To be considered a “mixture”, the aforesaid polymeric and non-polymeric materials comprising the barrier layer should be deposited under the same reaction conditions and/or at the same time. The weight ratio of polymeric 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 created from the same precursor material. In one example, the mixture of a polymeric material and a non-polymeric material consists essentially of polymeric silicon and inorganic silicon.
Devices fabricated in accordance with embodiments of the invention can be incorporated into a wide variety of electronic component modules (or units) that can be incorporated into a variety of electronic products or intermediate components. Examples of such electronic products or intermediate components include display screens, lighting devices such as discrete light source devices or lighting panels, etc. that can be utilized by the end-user product manufacturers. Such electronic component modules can optionally include the driving electronics and/or power source(s). Devices fabricated in accordance with embodiments of the invention can be incorporated into a wide variety of consumer products that have one or more of the electronic component modules (or units) incorporated therein. A consumer product comprising an OLED that includes the compound of the present disclosure in the organic layer in the OLED is disclosed. Such consumer products would include any kind of products that include one or more light source(s) and/or one or more of some type of visual displays. Some examples of such consumer products include flat panel displays, curved displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior illumination and/or signaling, heads-up displays, fully or partially transparent displays, flexible displays, rollable displays, foldable displays, stretchable displays, laser printers, telephones, mobile phones, tablets, phablets, personal digital assistants (PDAs), wearable devices, laptop computers, digital cameras, camcorders, viewfinders, micro-displays (displays that are less than 2 inches diagonal), 3-D displays, virtual reality or augmented reality displays, vehicles, video walls comprising multiple displays tiled together, theater or stadium screen, a light therapy device, and a sign. Various control mechanisms may be used to control devices fabricated in accordance with the present invention, including passive matrix and active matrix. Many of the devices are intended for use in a temperature range comfortable to humans, such as 18 degrees C. to 30 degrees C., and more preferably at room temperature (20-25 degrees C.), but could be used outside this temperature range, for example, from −40 degree C. to +80 degree C.
The materials and structures described herein may have applications in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors may employ the materials and structures. More generally, organic devices, such as organic transistors, may employ the materials and structures.
The terms “halo,” “halogen,” and “halide” are used interchangeably and refer to fluorine, chlorine, bromine, and iodine.
The term “acyl” refers to a substituted carbonyl radical (C(O)—Rs).
The term “ester” refers to a substituted oxycarbonyl (—O—C(O)—Rs or —C(O)—O—Rs) radical.
The term “ether” refers to an —ORs radical.
The terms “sulfanyl” or “thio-ether” are used interchangeably and refer to a —SRs radical.
The term “sulfinyl” refers to a —S(O)—Rs radical.
The term “sulfonyl” refers to a —SO2—Rs radical.
The term “phosphino” refers to a —P(Rs)3 radical, wherein each Rs can be same or different.
The term “silyl” refers to a —Si(Rs)3 radical, wherein each Rs can be same or different.
In each of the above, Rs can be hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, and combination thereof. Preferred Rs is selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, and combination thereof.
The term “alkyl” refers to and includes both straight and branched chain alkyl radicals. Preferred alkyl groups are those containing from one to fifteen carbon atoms and includes methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, and the like. Additionally, the alkyl group is optionally substituted.
The term “cycloalkyl” refers to and includes monocyclic, polycyclic, and spiro alkyl radicals. Preferred cycloalkyl groups are those containing 3 to 12 ring carbon atoms and includes cyclopropyl, cyclopentyl, cyclohexyl, bicyclo[3.1.1]heptyl, spiro[4.5]decyl, spiro[5.5]undecyl, adamantyl, and the like. Additionally, the cycloalkyl group is optionally substituted.
The terms “heteroalkyl” or “heterocycloalkyl” refer to an alkyl or a cycloalkyl radical, respectively, having at least one carbon atom replaced by a heteroatom. Optionally the at least one heteroatom is selected from O, S, N, P, B, Si and Se, preferably, O, S or N. Additionally, the heteroalkyl or heterocycloalkyl group is optionally substituted.
The term “alkenyl” refers to and includes both straight and branched chain alkene radicals. Alkenyl groups are essentially alkyl groups that include at least one carbon-carbon double bond in the alkyl chain. Cycloalkenyl groups are essentially cycloalkyl groups that include at least one carbon-carbon double bond in the cycloalkyl ring. The term “heteroalkenyl” as used herein refers to an alkenyl radical having at least one carbon atom replaced by a heteroatom. Optionally the at least one heteroatom is selected from O, S, N, P, B, Si, and Se, preferably, O, S, or N. Preferred alkenyl, cycloalkenyl, or heteroalkenyl groups are those containing two to fifteen carbon atoms. Additionally, the alkenyl, cycloalkenyl, or heteroalkenyl group is optionally substituted.
The term “alkynyl” refers to and includes both straight and branched chain alkyne radicals. Preferred alkynyl groups are those containing two to fifteen carbon atoms. Additionally, the alkynyl group is optionally substituted.
The terms “aralkyl” or “arylalkyl” are used interchangeably and refer to an alkyl group that is substituted with an aryl group. Additionally, the aralkyl group is optionally substituted.
The term “heterocyclic group” refers to and includes aromatic and non-aromatic cyclic radicals containing at least one heteroatom. Optionally the at least one heteroatom is selected from O, S, N, P, B, Si, and Se, preferably, O, S, or N. Hetero-aromatic cyclic radicals may be used interchangeably with heteroaryl. Preferred hetero-non-aromatic cyclic groups are those containing 3 to 7 ring atoms which includes at least one hetero atom, and includes cyclic amines such as morpholino, piperidino, pyrrolidino, and the like, and cyclic ethers/thio-ethers, such as tetrahydrofuran, tetrahydropyran, tetrahydrothiophene, and the like. Additionally, the heterocyclic group may be optionally substituted.
The term “aryl” refers to and includes both single-ring aromatic hydrocarbyl groups and polycyclic aromatic ring systems. The polycyclic rings may 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 an aromatic hydrocarbyl group, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryl, heterocycles, and/or heteroaryls. Preferred aryl groups are those containing six to thirty carbon atoms, preferably six to twenty carbon atoms, more preferably six to twelve carbon atoms. Especially preferred is an aryl group having six carbons, ten carbons or twelve carbons. Suitable aryl groups include phenyl, biphenyl, triphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene, preferably phenyl, biphenyl, triphenyl, triphenylene, fluorene, and naphthalene. Additionally, the aryl group is optionally substituted.
The term “heteroaryl” refers to and includes both single-ring aromatic groups and polycyclic aromatic ring systems that include at least one heteroatom. The heteroatoms include, but are not limited to O, S, N, P, B, Si, and SC. In many instances, O, S, or N are the preferred heteroatoms. Hetero-single ring aromatic systems are preferably single rings with 5 or 6 ring atoms, and the ring can have from one to six heteroatoms. The hetero-polycyclic ring systems can have 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 a heteroaryl, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryl, heterocycles, and/or heteroaryls. The hetero-polycyclic aromatic ring systems can have from one to six heteroatoms per ring of the polycyclic aromatic ring system. Preferred heteroaryl groups are those containing three to thirty carbon atoms, preferably three to twenty carbon atoms, more preferably three to twelve carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine, preferably dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 1,2-azaborine, 1,3-azaborine, 1,4-azaborine, borazine, and aza-analogs thereof. Additionally, the heteroaryl group is optionally substituted.
Of the aryl and heteroaryl groups listed above, the groups of triphenylene, naphthalene, anthracene, dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, pyrazine, pyrimidine, triazine, and benzimidazole, and the respective aza-analogs of each thereof are of particular interest.
The terms alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aralkyl, heterocyclic group, aryl, and heteroaryl, as used herein, are independently unsubstituted, or independently substituted, with one or more general substituents.
In many instances, the general substituents are selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.
In some instances, the preferred general substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, and combinations thereof.
In some instances, the preferred general substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, alkoxy, aryloxy, amino, silyl, aryl, heteroaryl, sulfanyl, and combinations thereof.
In yet other instances, the more preferred general substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.
The terms “substituted” and “substitution” refer to a substituent other than H that is bonded to the relevant position, e.g., a carbon or nitrogen. For example, when R1 represents mono-substitution, then one R1 must be other than H (i.e., a substitution). Similarly, when R1 represents di-substitution, then two of R1 must be other than H. Similarly, when R1 represents no substitution, R1, for example, can be a hydrogen for available valencies of ring atoms, as in carbon atoms for benzene and the nitrogen atom in pyrrole, or simply represents nothing for ring atoms with fully filled valencies, e.g., the nitrogen atom in pyridine. The maximum number of substitutions possible in a ring structure will depend on the total number of available valencies in the ring atoms.
As used herein, “combinations thereof” indicates that one or more members of the applicable list are combined to form a known or chemically stable arrangement that one of ordinary skill in the art can envision from the applicable list. For example, an alkyl and deuterium can be combined to form a partial or fully deuterated alkyl group; a halogen and alkyl can be combined to form a halogenated alkyl substituent; and a halogen, alkyl, and aryl can be combined to form a halogenated arylalkyl. In one instance, the term substitution includes a combination of two to four of the listed groups. In another instance, the term substitution includes a combination of two to three groups. In yet another instance, the term substitution includes a combination of two groups. Preferred combinations of substituent groups are those that contain up to fifty atoms that are not hydrogen or deuterium, or those which include up to forty atoms that are not hydrogen or deuterium, or those that include up to thirty atoms that are not hydrogen or deuterium. In many instances, a preferred combination of substituent groups will include up to twenty atoms that are not hydrogen or deuterium.
The “aza” designation in the fragments described herein, i.e. aza-dibenzofuran, aza-dibenzothiophene, etc. means that one or more of the C—H groups in the respective aromatic ring can be replaced by a nitrogen atom, for example, and without any limitation, azatriphenylene encompasses both dibenzo[f,h]quinoxaline and dibenzo[f,h]quinoline. One of ordinary skill in the art can readily envision other nitrogen analogs of the aza-derivatives described above, and all such analogs are intended to be encompassed by the terms as set forth herein.
As used herein, “deuterium” refers to an isotope of hydrogen. Deuterated compounds can be readily prepared using methods known in the art. For example, U.S. Pat. No. 8,557,400, Patent Pub. No. WO 2006/095951, and U.S. Pat. Application Pub. No. US 2011/0037057, which are hereby incorporated by reference in their entireties, describe the making of deuterium-substituted organometallic complexes. Further reference is made to Ming Yan, et al., Tetrahedron 2015, 71, 1425-30 and Atzrodt et al., Angew. Chem. Int. Ed. (Reviews) 2007, 46, 7744-65, which are incorporated by reference in their entireties, describe the deuteration of the methylene hydrogens in benzyl amines and efficient pathways to replace aromatic ring hydrogens with deuterium, respectively.
It is to be understood that when a molecular fragment is described as being a substituent or otherwise attached to another moiety, its name may be written as if it were a fragment (e.g. phenyl, phenylene, naphthyl, dibenzofuryl) or as if it were the whole molecule (e.g. benzene, naphthalene, dibenzofuran). As used herein, these different ways of designating a substituent or attached fragment are considered to be equivalent.
According to an aspect of the present disclosure, a compound comprising a first ligand LA is disclosed, where LA is selected from the group consisting of:
wherein,
A is a 5- or 6-membered aromatic ring;
Y1 to Y9 are each independently selected from the group consisting of C and N; wherein Z is C or N;
RA, RB, RC, and RD represent mono to a maximum possible number of substitutions, or no substitution;
each RA, RB, RC, and RD is independently a hydrogen or one of the general substituents defined above;
any two RA substituents can be joined or fused together to form a ring;
LA is complexed to a metal M to form a five-membered chelate ring;
M is optionally coordinated to other ligands; and
the ligand LA is optionally linked with other ligands to form a ligand having a denticity of tridentate to a maximum possible number of denticity to which M can coordinate.
In some embodiments of the compound, RA, RB, RC, and RD are each a hydrogen or one of the preferred general substituents or more preferred general substituents defined above.
In some embodiments, M is a metal whose atomic mass is greater than 40. In some embodiments, M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Au, and Cu. In some embodiments, M is Ir or Pt. In some embodiments, M is Ir(III) or Pt(II).
In some embodiments of the compound, the compound is homoleptic. In some embodiments, the compound is heteroleptic.
In some embodiments, Y1 to Y9 are each C. In some embodiments, at least one of Y1 to Y9 is N. In some embodiments, one of Y1 to Y3 is N.
In some embodiments of the compound, Z is N, and Y1 is C. In some embodiments, Z is C.
In some embodiments of the compound, A is selected from the group consisting of pyridine, pyrimidine, imidazole, pyrazole, and N-heterocyclic carbene.
In some embodiments of the compound, LA is selected from the group consisting of:
wherein RE is selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, partially or fully deuterated variants thereof, partially or fully fluorinated variants thereof, and combination thereof.
In some embodiments of the compound, LA is selected from the group consisting of:
In some embodiments of the compound where LA is selected from the group consisting of LA1 to LA121, the compound has a formula of M(LA)x(LB)y(LC)z where LB and LC are each a bidentate ligand; and wherein x is 1, 2, or 3; y is 1, or 2; z is 0, 1, or 2; and x+y+z is the oxidation state of the metal M. In some embodiments, the compound has a formula selected from the group consisting of Ir(LA)3, Ir(LA)(LB)2, Ir(LA)2(LB), Ir(LA)2(LC), Ir(LA) (LC)2, and Ir(LA)(LB)(LC); and wherein LA, LB, and LC are different from each other.
In some embodiments of the compound where LA is selected from the group consisting of LA1 to LA121, the compound has a formula of Pt(LA)(LB); and LA and LB can be same or different. In some embodiments of the compound having the formula of Pt(LA)(LB), LA and LB are connected to form a tetradentate ligand. In some embodiments of the compound having the formula of Pt(LA)(LB), LA and LB are connected at two places to form a macrocyclic tetradentate ligand.
In some embodiments of the compound having the formula of M(LA)x(LB)y(LC)z where LB and LC are each a bidentate ligand, LB and LC are each independently selected from the group consisting of:
where,
each X1 to X13 are independently selected from the group consisting of carbon and nitrogen;
X is selected from the group consisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO2, CR′R″, SiR′R″, and GeR′R″;
R′ and R″ are optionally fused or joined to form a ring;
each Ra, Rb, Rc and Rd can represent from mono to a maximum possible number of substitutions, or no substitution;
R′, R″, Ra, Rb, Rc, and Rd are each independently a hydrogen or one of the general substituents defined above; and
any two adjacent substitutents of Ra, Rb, Rc and Rd are optionally fused or joined to form a ring or form a multidentate ligand. In some embodiments, R′, R″, Ra, Rb, Rc and Rd are each independently a hydrogen or one of the preferred general substituents or one of the more preferred general substituents defined above.
In some embodiments of the compound having the formula of M(LA)x(LB)y(LC)z where LB and LC are each a bidentate ligand, wherein LB and LC are each independently selected from the group consisting of:
In some embodiments of the compound having a formula selected from the group consisting of Ir(LA)3, Ir(LA)(LB)2, Ir(LA)2(LB), Ir(LA)2(LC), Ir(LA) (LC)2, and Ir(LA)(LB)(LC); and wherein LA, LB, and LC are different from each other, the compound is Compound Axx having the formula Ir(LAi)3, Compound Byy having the formula Ir(LAi)(LBk)2, or Compound Czz having the formula Ir(LAi)2(LCj);
where, xx=i; and i is an integer from 1 to 121;
where, yy=121+k−121; k is an integer from 1 to 461;
where, zz=27i+j−27; j is an integer from 1 to 1260; and
where, LBk has the following structures:
where LC1 through LC1260 are based on a structure of Formula X,
in which R1, R2, and R3 are defined as:
wherein RD1 to RD81 has the following structures:
An organic light emitting device (OLED) is also disclosed. The OLED comprising: an anode; a cathode; and an organic layer, disposed between the anode and the cathode, comprising a compound comprising a first ligand LA selected from the group consisting of:
where,
A is a 5- or 6-membered aromatic ring;
Y1-Y9 are each independently selected from the group consisting of C and N;
Z is C or N;
RA, RB, RC, and RD represent mono to a maximum possible number of substitutions, or no substitution;
each RA, RB, RC, and RD is independently a hydrogen or one of the general substituents defined above;
any two RA substituents can be joined or fused together to form a ring;
LA is complexed to a metal M;
M is optionally coordinated to other ligands; and
the ligand LA is optionally linked with other ligands to form a ligand having a denticity of tridentate to a maximum possible number of denticity to which M can coordinate.
In some embodiments of the OLED, the organic layer is an emissive layer and the compound is an emissive dopant or a non-emissive dopant.
In some embodiments of the OLED, the organic layer further comprises a host, wherein the host comprises at least one chemical group selected from the group consisting of triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene. In some embodiments of the OLED, the host is selected from the group consisting of:
and combinations thereof.
In some embodiments of the OLED where the organic layer further comprises a host, the host comprises a metal complex.
A consumer product comprising an OLED is also disclosed. The OLED comprising: an anode; a cathode; and an organic layer, disposed between the anode and the cathode, comprising a compound comprising a first ligand LA selected from the group consisting of:
wherein,
A is a 5- or 6-membered aromatic ring;
Y1-Y9 are each independently selected from the group consisting of C and N;
Z is C or N;
RA, RB, RC, and RD represent mono to a maximum possible number of substitutions, or no substitution;
each RA, RB, RC, and RD is independently a hydrogen or one of the general substituents defined above;
any two RA substituents can be joined or fused together to form a ring;
LA is complexed to a metal M;
M is optionally coordinated to other ligands; and
the ligand LA is optionally linked with other ligands to form a ligand having a denticity of tridentate to a maximum possible number of denticity to which M can coordinate.
In some embodiments, the OLED has one or more characteristics selected from the group consisting of being flexible, being rollable, being foldable, being stretchable, and being curved. In some embodiments, the OLED is transparent or semi-transparent. In some embodiments, the OLED further comprises a layer comprising carbon nanotubes.
In some embodiments, the OLED further comprises a layer comprising a delayed fluorescent emitter. In some embodiments, the OLED comprises a RGB pixel arrangement or white plus color filter pixel arrangement. In some embodiments, the OLED is a mobile device, a hand held device, or a wearable device. In some embodiments, the OLED is a display panel having less than 10 inch diagonal or 50 square inch area. In some embodiments, the OLED is a display panel having at least 10 inch diagonal or 50 square inch area. In some embodiments, the OLED is a lighting panel.
An emissive region in an OLED is also disclosed. The emissive region comprising a compound comprising a first ligand LA is disclosed, where LA is selected from the group consisting of:
wherein,
A is a 5- or 6-membered aromatic ring;
Y1 to Y9 are each independently selected from the group consisting of C and N; wherein Z is C or N;
RA, RB, RC, and RD represent mono to a maximum possible number of substitutions, or no substitution;
each RA, RB, RC, and RD is independently a hydrogen or one of the general substituents defined above;
any two RA substituents can be joined or fused together to form a ring;
LA is complexed to a metal M to form a five-membered chelate ring;
M is optionally coordinated to other ligands; and
the ligand LA is optionally linked with other ligands to form a ligand having a denticity of tridentate to a maximum possible number of denticity to which M can coordinate.
In some embodiments of the emissive region, the compound is an emissive dopant or a non-emissive dopant. In some embodiments, the emissive region further comprises a host, wherein the host comprises at least one group selected from the group consisting of metal complex, triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, aza-triphenylene, aza-carbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene.
In some embodiments, the emissive region further comprises a host, wherein the host is selected from the group consisting of:
and combinations thereof
In some embodiments, the compound can be an emissive dopant. In some embodiments, the compound can produce emissions via phosphorescence, fluorescence, thermally activated delayed fluorescence, i.e., TADF (also referred to as E-type delayed fluorescence; see, e.g., U.S. application Ser. No. 15/700,352, which is hereby incorporated by reference in its entirety), triplet-triplet annihilation, or combinations of these processes. In some embodiments, the emissive dopant can be a racemic mixture, or can be enriched in one enantiomer.
According to another aspect, a formulation comprising the compound described herein is also disclosed.
The OLED disclosed herein can be incorporated into one or more of a consumer product, an electronic component module, and a lighting panel. The organic layer can be an emissive layer and the compound can be an emissive dopant in some embodiments, while the compound can be a non-emissive dopant in other embodiments.
The organic layer can also include a host. In some embodiments, two or more hosts are preferred. In some embodiments, the hosts used maybe a) bipolar, b) electron transporting, c) hole transporting or d) wide band gap materials that play little role in charge transport. In some embodiments, the host can include a metal complex. The host can be a triphenylene containing benzo-fused thiophene or benzo-fused furan. Any substituent in the host can be an unfused substituent independently selected from the group consisting of CnH2n+1, OCnH2n+1, OAr1, N(CnH2n+1)2, N(Ar1)(Ar2), CH═CH—CnH2n+1, C≡C—CnH2n+1, Ar1, Ar1—Ar2, and CnH2n—Ar1, or the host has no substitutions. In the preceding substituents n can range from 1 to 10; and Ar1 and Ar2 can be independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and heteroaromatic analogs thereof. The host can be an inorganic compound. For example a Zn containing inorganic material e.g. ZnS.
The host can be a compound comprising at least one chemical group selected from the group consisting of triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene. The host can include a metal complex. The host can be, but is not limited to, a specific compound selected from the group consisting of:
and combinations thereof.
Additional information on possible hosts is provided below.
In yet another aspect of the present disclosure, a formulation that comprises the novel compound disclosed herein is described. The formulation can include one or more components selected from the group consisting of a solvent, a host, a hole injection material, hole transport material, electron blocking material, hole blocking material, and an electron transport material, disclosed herein.
Combination with Other Materials
The materials described herein as useful for a particular layer in an organic light emitting device may be used in combination with a wide variety of other materials present in the device. For example, emissive dopants disclosed herein may be used in conjunction with a wide variety of hosts, transport layers, blocking layers, injection layers, electrodes and other layers that may be present. The materials described or referred to below are non-limiting examples of materials that may be useful in combination with the compounds disclosed herein, and one of skill in the art can readily consult the literature to identify other materials that may be useful in combination.
Conductivity Dopants:
A charge transport layer can be doped with conductivity dopants to substantially alter its density of charge carriers, which will in turn alter its conductivity. The conductivity is increased by generating charge carriers in the matrix material, and depending on the type of dopant, a change in the Fermi level of the semiconductor may also be achieved. Hole-transporting layer can be doped by p-type conductivity dopants and n-type conductivity dopants are used in the electron-transporting layer.
Non-limiting examples of the conductivity dopants that may be used in an OLED in combination with materials disclosed herein are exemplified below together with references that disclose those materials: EP01617493, EP01968131, EP2020694, EP2684932, US20050139810, US20070160905, US20090167167, US2010288362, WO06081780, WO2009003455, WO2009008277, WO2009011327, WO2014009310, US2007252140, US2015060804, US20150123047, and US2012146012.
HIL/HTL:
A hole injecting/transporting material to be used in the present invention is not particularly limited, and any compound may be used as long as the compound is typically used as a hole injecting/transporting material. Examples of the material include, but are not limited to: a phthalocyanine or porphyrin derivative; an aromatic amine derivative; an indolocarbazole derivative; a polymer containing fluorohydrocarbon; a polymer with conductivity dopants; a conducting polymer, such as PEDOT/PSS; a self-assembly monomer derived from compounds such as phosphonic acid and silane derivatives; a metal oxide derivative, such as MoOx; a p-type semiconducting organic compound, such as 1,4,5,8,9,12-Hexaazatriphenylenehexacarbonitrile; a metal complex, and a cross-linkable compounds.
Examples of aromatic amine derivatives used in HIL or HTL include, but not limit to the following general structures:
Each of Ar1 to Ar9 is selected from the group consisting of aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene; the group consisting of aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine; and the group consisting of 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group. Each Ar may be unsubstituted or may be substituted by a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acids, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.
In one aspect, Ar1 to Ar9 is independently selected from the group consisting of:
wherein k is an integer from 1 to 20; X101 to X108 is C (including CH) or N; Z101 is NAr1, O, or S; Ar1 has the same group defined above.
Examples of metal complexes used in HIL or HTL include, but are not limited to the following general formula:
wherein Met is a metal, which can have an atomic weight greater than 40; (Y101-Y102) is a bidentate ligand, Y101 and Y102 are independently selected from C, N, O, P, and S; L101 is an ancillary ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal; and k′+k″ is the maximum number of ligands that may be attached to the metal.
In one aspect, (Y101-Y102) is a 2-phenylpyridine derivative. In another aspect, (Y101-Y102) is a carbene ligand. In another aspect, Met is selected from Ir, Pt, Os, and Zn. In a further aspect, the metal complex has a smallest oxidation potential in solution vs. Fc+/Fc couple less than about 0.6 V.
Non-limiting examples of the HIL and HTL materials that may be used in an OLED in combination with materials disclosed herein are exemplified below together with references that disclose those materials: CN102702075, DE102012005215, EP01624500, EP01698613, EP01806334, EP01930964, EP01972613, EP01997799, EP02011790, EP02055700, EP02055701, EP1725079, EP2085382, EP2660300, EP650955, JP07-073529, JP2005112765, JP2007091719, JP2008021687, JP2014-009196, KR20110088898, KR20130077473, TW201139402, U.S. Ser. No. 06/517,957, US20020158242, US20030162053, US20050123751, US20060182993, US20060240279, US20070145888, US20070181874, US20070278938, US20080014464, US20080091025, US20080106190, US20080124572, US20080145707, US20080220265, US20080233434, US20080303417, US2008107919, US20090115320, US20090167161, US2009066235, US2011007385, US20110163302, US2011240968, US2011278551, US2012205642, US2013241401, US20140117329, US2014183517, U.S. Pat. Nos. 5,061,569, 5,639,914, WO05075451, WO07125714, WO08023550, WO08023759, WO2009145016, WO2010061824, WO2011075644, WO2012177006, WO2013018530, WO2013039073, WO2013087142, WO2013118812, WO2013120577, WO2013157367, WO2013175747, WO2014002873, WO2014015935, WO2014015937, WO2014030872, WO2014030921, WO2014034791, WO2014104514, WO2014157018.
EBL:
An electron blocking layer (EBL) may be used to reduce the number of electrons and/or excitons that leave the emissive layer. The presence of such a blocking layer in a device may result in substantially higher efficiencies, and/or longer lifetime, as compared to a similar device lacking a blocking layer. Also, a blocking layer may be used to confine emission to a desired region of an OLED. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and/or higher triplet energy than the emitter closest to the EBL interface. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and/or higher triplet energy than one or more of the hosts closest to the EBL interface. In one aspect, the compound used in EBL contains the same molecule or the same functional groups used as one of the hosts described below.
Host:
The light emitting layer of the organic EL device of the present invention preferably contains at least a metal complex as 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 complexes or organic compounds may be used as long as the triplet energy of the host is larger than that of the dopant. Any host material may be used with any dopant so long as the triplet criteria is satisfied.
Examples of metal complexes used as host are preferred to have the following general formula:
wherein Met is a metal; (Y103-Y104) is a bidentate ligand, Y103 and Y104 are independently selected from C, N, O, P, and S; L101 is an another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal; and k′+k″ is the maximum number of ligands that may be attached to the metal.
In one aspect, the metal complexes are:
wherein (O—N) is a bidentate ligand, having metal coordinated to atoms O and N.
In another aspect, Met is selected from Ir and Pt. In a further aspect, (Y103-Y104) is a carbene ligand.
In one aspect, the host compound contains at least one of the following groups selected from the group consisting of aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene; the group consisting of aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine; and the group consisting of 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group. Each option within each group may be unsubstituted or may be substituted by a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acids, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.
In one aspect, the host compound contains at least one of the following groups in the molecule:
wherein R101 is selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acids, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof, and when it is aryl or heteroaryl, it has the similar definition as Ar's mentioned above. k is an integer from 0 to 20 or 1 to 20. X101 to X101 are independently selected from C (including CH) or N. Z101 and Z102 are independently selected from NR101, O, or S.
Non-limiting examples of the host materials that may be used in an OLED in combination with materials disclosed herein are exemplified below together with references that disclose those materials: EP2034538, EP2034538A, EP2757608, JP2007254297, KR20100079458, KR20120088644, KR20120129733, KR20130115564, TW201329200, US20030175553, US20050238919, US20060280965, US20090017330, US20090030202, US20090167162, US20090302743, US20090309488, US20100012931, US20100084966, US20100187984, US2010187984, US2012075273, US2012126221, US2013009543, US2013105787, US2013175519, US2014001446, US20140183503, US20140225088, US2014034914, U.S. Pat. No. 7,154,114, WO2001039234, WO2004093207, WO2005014551, WO2005089025, WO2006072002, WO2006114966, WO2007063754, WO2008056746, WO2009003898, WO2009021126, WO2009063833, WO2009066778, WO2009066779, WO2009086028, WO2010056066, WO2010107244, WO2011081423, WO2011081431, WO2011086863, WO2012128298, WO2012133644, WO2012133649, WO2013024872, WO2013035275, WO2013081315, WO2013191404, WO2014142472, US20170263869, US20160163995, U.S. Pat. No. 9,466,803,
Additional Emitters:
One or more additional emitter dopants may be used in conjunction with the compound of the present disclosure. Examples of the additional emitter dopants are not particularly limited, and any compounds may be used as long as the compounds are typically used as emitter materials. Examples of suitable emitter materials include, but are not limited to, compounds which can produce emissions via phosphorescence, fluorescence, thermally activated delayed fluorescence, i.e., TADF (also referred to as E-type delayed fluorescence), triplet-triplet annihilation, or combinations of these processes.
Non-limiting examples of the emitter materials that may be used in an OLED in combination with materials disclosed herein are exemplified below together with references that disclose those materials: CN103694277, CN1696137, EB01238981, EP01239526, EP01961743, EP1239526, EP1244155, EP1642951, EP1647554, EP1841834, EP1841834B, EP2062907, EP2730583, JP2012074444, JP2013110263, JP4478555, KR1020090133652, KR20120032054, KR20130043460, TW201332980, U.S. Ser. No. 06/699,599, U.S. Ser. No. 06/916,554, US20010019782, US20020034656, US20030068526, US20030072964, US20030138657, US20050123788, US20050244673, US2005123791, US2005260449, US20060008670, US20060065890, US20060127696, US20060134459, US20060134462, US20060202194, US20060251923, US20070034863, US20070087321, US20070103060, US20070111026, US20070190359, US20070231600, US2007034863, US2007104979, US2007104980, US2007138437, US2007224450, US2007278936, US20080020237, US20080233410, US20080261076, US20080297033, US200805851, US2008161567, US2008210930, US20090039776, US20090108737, US20090115322, US20090179555, US2009085476, US2009104472, US20100090591, US20100148663, US20100244004, US20100295032, US2010102716, US2010105902, US2010244004, US2010270916, US20110057559, US20110108822, US20110204333, US2011215710, US2011227049, US2011285275, US2012292601, US20130146848, US2013033172, US2013165653, US2013181190, US2013334521, US20140246656, US2014103305, U.S. Pat. Nos. 6,303,238, 6,413,656, 6,653,654, 6,670,645, 6,687,266, 6,835,469, 6,921,915, 7,279,704, 7,332,232, 7,378,162, 7,534,505, 7,675,228, 7,728,137, 7,740,957, 7,759,489, 7,951,947, 8,067,099, 8,592,586, 8,871,361, WO06081973, WO06121811, WO07018067, WO07108362, WO07115970, WO07115981, WO08035571, WO2002015645, WO2003040257, WO2005019373, WO2006056418, WO2008054584, WO2008078800, WO2008096609, WO2008101842, WO2009000673, WO2009050281, WO2009100991, WO2010028151, WO2010054731, WO2010086089, WO2010118029, WO2011044988, WO2011051404, WO2011107491, WO2012020327, WO2012163471, WO2013094620, WO2013107487, WO2013174471, WO2014007565, WO2014008982, WO2014023377, WO2014024131, WO2014031977, WO2014038456, WO2014112450.
HBL:
A hole blocking layer (HBL) may be used to reduce the number of holes and/or excitons that leave the emissive layer. The presence of such a blocking layer in a device may result in substantially higher efficiencies and/or longer lifetime as compared to a similar device lacking a blocking layer. Also, a blocking layer may be used to confine emission to a desired region of an OLED. In some embodiments, the HBL material has a lower HOMO (further from the vacuum level) and/or higher triplet energy than the emitter closest to the HBL interface. In some embodiments, the HBL material has a lower HOMO (further from the vacuum level) and/or higher triplet energy than one or more of the hosts closest to the HBL interface.
In one aspect, compound used in HBL contains the same molecule or the same functional groups used as host described above.
In another aspect, compound used in HBL contains at least one of the following groups in the molecule:
wherein k is an integer from 1 to 20; L101 is an another ligand, k′ is an integer from 1 to 3.
ETL:
Electron transport layer (ETL) may include a material capable of transporting electrons. 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 complexes or organic compounds may be used as long as they are typically used to transport electrons.
In one aspect, compound used in ETL contains at least one of the following groups in the molecule:
wherein R101 is selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acids, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof, when it is aryl or heteroaryl, it has the similar definition as Ar's mentioned above. Ar1 to Ar3 has the similar definition as Ar's mentioned above. k is an integer from 1 to 20. X101 to X101 is selected from C (including CH) or N.
In another aspect, the metal complexes used in ETL contains, but not limit to the following general formula:
wherein (O—N) or (N—N) is a bidentate ligand, having metal coordinated to atoms O, N or N, N; L101 is another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal.
Non-limiting examples of the ETL materials that may be used in an OLED in combination with materials disclosed herein are exemplified below together with references that disclose those materials: CN103508940, EP01602648, EP01734038, EP01956007, JP2004-022334, JP2005149918, JP2005-268199, KR0117693, KR20130108183, US20040036077, US20070104977, US2007018155, US20090101870, US20090115316, US20090140637, US20090179554, US2009218940, US2010108990, US2011156017, US2011210320, US2012193612, US2012214993, US2014014925, US2014014927, US20140284580, U.S. Pat. Nos. 6,656,612, 8,415,031, WO2003060956, WO2007111263, WO2009148269, WO2010067894, WO2010072300, WO2011074770, WO2011105373, WO2013079217, WO2013145667, WO2013180376, WO2014104499, WO2014104535,
Charge Generation Layer (CGL)
In tandem or stacked OLEDs, the CGL plays an essential role in the performance, which is composed of an n-doped layer and a p-doped layer for injection of electrons and holes, respectively. Electrons and holes are supplied from the CGL and electrodes. The consumed electrons and holes in the CGL are refilled by the electrons and holes injected from the cathode and anode, respectively; then, the bipolar currents reach a steady state gradually. Typical CGL materials include n and p conductivity dopants used in the transport layers.
In any above-mentioned compounds used in each layer of the OLED device, the hydrogen atoms can be partially or fully deuterated. Thus, any specifically listed substituent, such as, without limitation, methyl, phenyl, pyridyl, etc. may be undeuterated, partially deuterated, and fully deuterated versions thereof. Similarly, classes of substituents such as, without limitation, alkyl, aryl, cycloalkyl, heteroaryl, etc. also may be undeuterated, partially deuterated, and fully deuterated versions thereof.
Synthesis of IrLA117(LB186)2:
A solution of Pd2(dba)3 (1.066 g, 1.164 mmol) and dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphane (Sphos, 1.911 g, 4.65 mmol) in dry degassed dioxane (200 mL) was prepared. Potassium acetate (5.71 g, 58.2 mmol), bis(pinacolato)diboron (7.09 g, 27.9 mmol) and 3-chlorophenanthrene (4.95 g, 23.27 mmol) was weighed into an oven dried flask, which was then evacuated and backfilled with N2 (×3), before the stock solution was added and the reaction stirred at 100° C. for 4 hrs; at which point Liquid chromatography-mass spectrometry (LC-MS) showed full consumption of the starting material. The reaction was cooled, filtered and concentrated to dryness. The crude residue was dry loaded onto silica and purified by column chromatography (0-50% DCM in isohexane) to give 4,4,5,5-tetramethyl-2-(phenanthren-3-yl)-1,3,2-dioxaborolane (5.55 g, 18.24 mmol, 78% yield) as a white solid.
2-Bromo-4,5-bis(methyl-d3)pyridine (2.501 g, 13.02 mmol), 4,4,5,5-tetramethyl-2-(phenanthren-2-yl)-1,3,2-dioxaborolane (3.76 g, 35.5 mmol) were suspended in DME (80 mL)/water (20.00 mL) mixture. The reaction mixture was degassed, potassium carbonate (3.76 g, 3 eq.) and tetrakis(triphenylphosphine) palladium(0) (0.547 g, 0.473 mmol) were added as one portion. The reaction mixture was heated at 100° C. under nitrogen for 14 hrs. After cooling down the reaction mixture was diluted with water and extracted with ethyl acetate. Organic solution was dried over sodium sulfate, filtered and evaporated. The residue was subjected to column chromatography on a silica gel column, eluted with ethyl acetate/DCM gradient mixture. Pure fractions were concentrated, triturated with MeOH, providing pure 4,5-bis(methyl-d3)-2-(phenanthren-3-yl)pyridine (2.0 g, 58% yield).
Iridium complex triflic salt (1.7 g, 1.981 mmol) and 4,5-bis(methyl-d3)-2-(phenanthren-3-yl)pyridine (1.204 g, 4.16 mmol) were suspended in DMF (30 ml)/2-ethoxyethanol (30.0 ml) mixture. The reaction was degassed and heated to 130° C. for 5 days. The reaction was cooled down, and solvents were evaporated. The residue was subjected to column chromatography on a silica gel column, eluted with heptanes/DCM/toluene (8/1/1, v/v/v) mixture, providing target material after evaporation (1.1 g, 61% yield).
Synthesis of IrLA118(LB169)2:
Potassium acetate (11.03 g, 112 mmol), bis(pinacolato)diboron (17.12 g, 67.4 mmol), 2-bromophenanthrene (14.45 g, 56.2 mmol) and Pd(dppf)Cl2·CHCl3 complex (1.37 g, 1.686 mmol) were charged to an oven-dried round bottom flask. Anhydrous dioxane (200 mL) was added and the mixture was sparged with nitrogen for 15 min. The reaction was stirred at 100° C. for 18 hrs, gas chromatography-mass spectrometry (GC-MS) analysis of the reaction mixture indicated full conversion to product. The reaction was cooled to room temperature and filtered to remove the base. The filtration liquor was concentrated in vacuo. The crude residue was partitioned between DCM and sat. NaHCO3 solution and the aqueous was reextracted with DCM. The combined organics were washed sequentially with sat. aqueous NaHCO3 and brine, before being dried over sodium sulphate. The organics were then filtered and dry loaded onto silica and the mixture purified by flash column chromatography (0-50% DCM in iso-hexane) to give 4,4,5,5-tetramethyl-2-(phenanthren-2-yl)-1,3,2-dioxaborolane (13.32 g, 43.8 mmol, 78% yield) as a colorless oil, which foamed and solidified upon drying under high vacuum to give an off-white solid.
4,4,5,5-Tetramethyl-2-(phenanthren-2-yl)-1,3,2-dioxaborolane (3.6 g, 11.8 mmol) and 2-bromo-4,5-bis(methyl-d3)pyridine (2.5 g, 13.02 mmol) were suspended in DME (80 ml)/water (20.00 ml) mixture. The reaction mixture was degassed, and tetrakis(triphenylphosphine) palladium(0) (0.547 g, 0.473 mmol) was added as one portion. The reaction mixture was heated at 100° C. under nitrogen for 12 hrs. It was then cooled down, diluted with brine and extracted with ethyl acetate. Organic solution was dried over sodium sulfate, filtered and evaporated. The residue was subjected to column chromatography on silica gel column, eluted with DCM/ethyl acetate gradient mixture, providing 4,5-bis(methyl-d3)-2-(phenanthren-2-yl)pyridine as white solid (1.8 g, 53% yield).
Iridium complex triflic salt (2.2 g, 2.94 mmol) and 4,5-bis(methyl-d3)-2-(phenanthren-2-yl)pyridine (1.788 g, 6.18 mmol) were suspended in DMF (30 ml)/2-ethoxyethanol (30.0 ml) mixture. The reaction mixture was degassed with N2, and heated to 90° C. for 6 days. Then the reaction mixture was cooled down, and solvents were evaporated. The crude material was subjected to column chromatography on silica gel column, eluted with heptanes/toluene gradient mixture, providing target material as bright yellow solid (1.80 g, 72% yield).
Step 1: 5 L 4-neck flask equipped with overhead stirrer, thermowell, and water condenser was charged with 1-(2-bromophenyl)ethan-1-one (50 g, 251 mmol), (4-chlorophenyl)boronic acid (49.1 g, 314 mmol), K2CO3 (104 g, 754 mmol), toluene (1200 ml) and water (600 ml). Pd(PPh3)4 (29.0 g, 25.1 mmol) was added into reaction mixture, degassed and heated to 73° C. for 14 h. Toluene layer was separated, concentrated and resulting residue was purified by column chromatography (EtOAc/heptane) to obtain 51 g (88% yield) of 1-(4′-chloro-[1,1′-biphenyl]-2-yl)ethan-1-one.
Step 2: A solution of 1-(4′-chloro-[1,1′-biphenyl]-2-yl)ethan-1-one (45.3 g, 196 mmol), pyridine (46.6 g, 589 mmol) and hydroxylamine hydrochloride (40.9 g, 589 mmol) in ethanol was refluxed for 14 h. The solvent was removed by rotary evaporation and the resulting residue was dissolved in EtOAc (1 L). Organic layer was washed with 2 M HCl solution (1 L), followed by brine, dried (Na2SO4) and concentrated to obtain E/Z mixture of (1-(4′-chloro-[1,1′-biphenyl]-2-yl)ethan-1-one oxime (42 g, 87% yield) which was used in the next step without further purification.
Step 3: To a stirred solution of E/Z mixture of 1-(4′-chloro-[1,1′-biphenyl]-2-yl)ethan-1-one oxime (41 g, 167 mmol) in CH2Cl2 (730 ml) was added triethylamine (69.8 ml, 501 mmol) under nitrogen atmosphere and then cooled to 0° C. A solution of acetyl chloride (23.81 ml, 334 mmol) in CH2Cl2 (70 ml) was slowly added into the reaction mixture and stirred at 2-4° C. for 2 hrs. Upon completion, reaction mixture was quenched with saturated NaHCO3 solution (1 L). Organic layer was separated, and aqueous layer was extracted with CH2Cl2 (2×500 mL). Combined organic layer was washed with brine, dried (Na2SO4) and concentrated to obtain 1-(4′-chloro-[1,1′-biphenyl]-2-yl)ethan-1-one O-acetyloxime as a mixture of Z(major)/E(minor) isomers which was used in next step without further purification.
Step 4: 2 L flask equipped with magnetic stir bar, thermowell and water condenser was charged with 1-(4′-chloro-[1,1′-biphenyl]-2-yl)ethan-1-one O-acetyl oxime (41 g, 142 mmol), Fe(acac)3 (1.006 g, 2.85 mmol) and acetic acid (100 ml). This mixture was heated to 80° C. for 24 h under nitrogen atmosphere. Reaction mixture was concentrated under reduced pressure, and resulting residue was washed with water (2 L). Brownish residue was dissolved in CH2Cl2, adsorbed on silica and purified by silica gel column chromatography (eluted with ethyl acetate/heptane gradient mixture). Further recrystallization with 5% EtOAc/heptane gave 99.9% pure 3-chloro-6 methylphenanthridine (16.3 g, 50% yield) as a pale-yellow solid. E-isomer of the oxime, and a mixture of E/Z-isomers participated in the reaction without any problem.
Step 5: 6-Methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenanthridine: A mixture of 3-chloro-6-methylphenanthridine (7 g, 30.74 mmol, 1.0 equiv), bis(pinacolato)diboron (10.14 g, 39.96 mmol, 1.3 equiv), tricyclohexyl-phosphine (0.431 g, 1.537 mmol, 0.05 equiv), potassium acetate (9.65 g, 98.36 mmol, 3.2 equiv) and tris(dibenzylideneacetone)dipalladium(0) (0.562 g, 0.614 mmol, 0.02 equiv) in 1,4-dioxane (150 mL) was degassed, then heated to reflux for 5 hrs. The cooled reaction mixture was diluted with ethyl acetate (200 mL) and water (80 mL) and the layers separated. The organic layer was washed with saturated brine (80 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel, eluting with a gradient of 0-35% ethyl acetate in heptanes, to give 6-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenanthridine (9.8 g, 100% yield) as a white solid.
Step 6: 3-(4,5-Dimethylpyridin-2-yl)-6-methylphenanthridine: A mixture of 6-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenanthridine (9.8 g, 30.7 mmol, 1.1 equiv), 2-chloro-4,5-dimethylpyridine (3.95 g, 27.9 mmol, 1.0 equiv), palladium(II) acetate (0.376 g, 1.674 mmol, 0.06 equiv), 2-dicyclohexylphosphino-2′,6′-dimethoxy-biphenyl (SPhos) (1.374 g, 3.35 mmol, 0.12 equiv) and potassium carbonate (7.7 g, 55.8 mmol, 2 equiv) in 1,4-dioxane (100 mL) and water (30 mL) was degassed, then heated to reflux overnight. The cooled reaction mixture was diluted with ethyl acetate (150 mL) and water (50 mL) and the layers separated. The organic layer was washed with saturated brine (50 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified on an silica gel column, eluting with a gradient of 30-50% ethyl acetate in heptanes, to give 3-(4,5-dimethylpyridin-2-yl)-6-methylphen-anthridine (4.7 g, 57% yield) as a white solid.
Step 1: To a degassed solution of 2-chloro-6-iodoaniline (50.7 g, 200 mmol), phenylboronic acid (30.5 g, 250 mmol), potassium carbonate (55.3 g, 400 mmol) in DME (800 ml) and water (200 ml) was added bis(triphenylphosphine)palladium(II) chloride (7.02 g, 10.00 mmol) and then refluxed for 12 hrs. After completion, the reaction mixture was diluted with H2O and then extracted with EtOAc. The combined organic layer was washed with brine, dried over Na2SO4 and concentrated. Resulting residue was purified by column chromatography to provide 3-chloro-[1,1′-biphenyl]-2-amine (37 g, 182 mmol, 91% yield) as a white solid.
Step 2: A solution of 3-chloro-[1,1′-biphenyl]-2-amine (35.0 g, 172 mmol) in CH2Cl2 (2000 ml) was stirred and cooled to 0° C. Lithium hydroxide hydrate (21.27 g, 507 mmol) was then added into the reaction mixture and stirred for 5 minutes. A solution of acetyl bromide (38.1 ml, 516 mmol) in CH2Cl2 (200 ml) was then added slowly over 1 hr while maintaining temperature below 5° C. The mixture was gradually warmed to room temperature and stirred for 2 h. After completion, the white suspension was passed through a pad of celite and washed with CH2Cl2. Combined CH2Cl2 filtrate was washed with water, dried over Na2SO4 and concentrated. The crude residue was purified by column chromatography CH2Cl2 and heptane to provide N-(3-chloro-[1,1′-biphenyl]-2-yl)acetamide (22.50 g, 92 mmol, 53.3% yield) as a white solid.
Step 3: Trifluoromethanesulfonic anhydride (22.81 ml, 135 mmol) was added dropwise into a stirred solution of triphenylphosphine oxide (75 g, 270 mmol) in anhydrous CH2Cl2 (721 ml) under nitrogen atmosphere at 0° C. After 1 hr stirring at 0° C., solution of N-(3-chloro-[1,1′-biphenyl]-2-yl)acetamide (22.11 g, 90 mmol) in anhydrous CH2Cl2 (433 ml) was added and resulting mixture was gradually warmed to room temperature and stirred for 60 h. The reaction was quenched by slow addition of saturated aqueous NaHCO3 solution and extracted with CH2Cl2. The combined organic layers were washed with brine, dried over Na2SO4, and concentrated. Crude residue was purified by column chromatography followed by recrystallization with heptane to obtain 10.2 g (49.7% yield) of 4-chloro-6-methylphenanthridine.
Step 4: 6-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenanthridine: A mixture of 4-chloro-6-methylphenanthridine (1.92 g, 8.43 mmol, 1.0 equiv), bis(pinacolato)diboron (2.24 g, 8.85 mmol, 1.05 equiv), potassium acetate (2.07 g, 21.08 mmol, 2.5 equiv) and SPhosPdG3 (0.164 g, 0.211 mmol, 0.025 equiv) in 1,4-dioxane (40 mL) was degassed, then it was heated to reflux for 5 h. The cooled reaction mixture was diluted with ethyl acetate (80 mL) and water (30 mL) and the layers separated. The organic layer was washed with brine (30 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure. Purification of the residue on silica gel column, eluting with a gradient of 20-70% ethyl acetate in heptanes, gave 6-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-phenanthridine (0.75 g, 28% yield) as a white solid.
Step 5: 4-(4,5-Dimethylpyridin-2-yl)-6-methylphenanthridine: 6-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenanthridine (0.75 g, 3.16 mmol, 1.0 equiv) was treated with purified 2-chloro-4,5-dimethylpyridine (0.448 g, 3.16 mmol, 1.0 equiv), palladium(II) diacetate (43 mg, 0.190 mmol, 0.06 equiv), 2-dicyclohexylphosphino-2′,6′-dimethoxy-biphenyl (SPhos) (0.156 g, 0.380 mmol, 0.12 equiv) and potassium carbonate (0.874 g, 6.33 mmol, 2.0 equiv) in 1,4-dioxane (15 mL) and water (5 mL). The reaction mixture was sparged with nitrogen for 10 minutes then heated at reflux overnight. The cooled reaction mixture was diluted with ethyl acetate (60 mL) and water (20 mL) and the payers separated. The organic layer was washed with saturated brine (20 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure. Purification of the residue by column chromatography on silica gel column, eluting with a gradient of 30-50% ethyl acetate in heptanes, gave 4-(4,5-dimethylpyridin-2-yl)-6-methylphenanthridine (0.3 g, 32% yield) as a white solid.
Step 1: To a 5 L flask was added 4-chloro-2-iodoaniline (90 g, 355 mmol), phenylboronic acid (52.0 g, 426 mmol), potassium carbonate (147 g, 1065 mmol), DME (720 ml) and water (720 ml). After degassing, bis(triphenylphosphine)palladium(II) chloride (4.98 g, 7.10 mmol) was added into the mixture and refluxed for 14 hrs. After completion, reaction mixture was diluted with EtOAc (1 L) and the two layers were separated. Aqueous layer was further extracted with EtOAc (2×500 mL), combined organic layer was dried over Na2SO4 and concentrated in vacuo. Resulting oil was purified by column chromatography using EtOAc/heptane to afford 5-chloro-[1,1′-biphenyl]-2-amine (90% yield).
Step 2: A solution of 5-chloro-[1,1′-biphenyl]-2-amine (73 g, 358 mmol) in CH2Cl2 (4 L) was stirred and cooled to 0° C. Lithium hydroxide hydrate (49.6 g, 1183 mmol) was then added into the reaction mixture and stirred for 5 minutes. A solution of acetyl chloride (84 g, 1075 mmol) in CH2Cl2 (500 ml) was added slowly over 1 hr while maintaining temperature below 5° C. The mixture was gradually warmed up to room temperature and stirred for 2 hrs. After completion, the white suspension was passed through a pad of celite and washed with CH2Cl2. Combined CH2Cl2 filtrate was washed with water, dried over Na2SO4 and concentrated. The crude residue was purified by column chromatography CH2Cl2 and heptane to provide N-(5-chloro-[1,1′-biphenyl]-2-yl)acetamide (80 g, 91% yield).
Step 3: Trifluoromethanesulfonic anhydride (44.9 ml, 266 mmol) was added dropwise into a stirred solution of triphenylphosphine oxide (148 g, 531 mmol) in anhydrous CH2Cl2 (1419 ml) under nitrogen atmosphere at 0° C. After 1 h stirring at 0° C., solution of N-(5-chloro-[1,1′-biphenyl]-2-yl)acetamide (43.5 g, 177 mmol) in anhydrous CH2Cl2 (433 ml) was added and resulting mixture was gradually warmed up to room temperature and stirred for 60 h. The reaction was quenched by slow addition of saturated aqueous NaHCO3 solution and extracted with CH2Cl2. The combined organic layers were washed with brine, dried over Na2SO4, and concentrated. Crude residue was purified by column chromatography on silica gel column to obtain 16.5 g (41% yield) of 2-chloro-6-methyl phenanthridine.
Step 4: 6-Methyl-9-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenanthridine: A mixture of 9-chloro-6-methylphenanthridine (7 g, 30.74 mmol, 1.0 equiv), bis(pinacolato)diboron (10.14 g, 39.96 mmol, 1.3 equiv), tricyclohexylphosphine (0.431 g, 1.537 mmol, 0.05 equiv), potassium acetate (9.65 g, 98.36 mmol, 3.2 equiv) and tris(dibenzylideneacetone)dipalladium(0) (0.562 g, 0.614 mmol, 0.02 equiv) in 1,4-dioxane (150 mL) was degassed, then heated to reflux for 5 hours. The cooled reaction mixture was diluted with ethyl acetate (200 mL) and water (80 mL) and the layers separated. The organic layer was washed with brine (80 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure. Purification of the residue on silica gel column, eluting with a gradient of 0-30% ethyl acetate in heptanes, gave 6-methyl-9-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenanthridine (9.8 g, 100% crude yield) as a white solid.
Step 5: 9-(4,5-Dimethylpyridin-2-yl)-6-methylphenanthridine: A mixture of 6-methyl-9-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenanthridine (9.8 g, 30.7 mmol, 1.1 equiv), purified 2-chloro-4,5-dimethylpyridine (3.95 g, 27.9 mmol, 1.0 equiv), palladium(II) acetate (0.376 g, 1.674 mmol, 0.06 equiv), 2-dicyclohexylphosphino-2′,6′-dimethoxy-biphenyl (SPhos) (1.37 g, 3.35 mmol, 0.12 equiv) and potassium carbonate (7.7 g, 55.8 mmol, 2.0 equiv) in 1,4-diox-ane (100 mL) and water (30 mL) was degassed, then heated to reflux for 14 hrs. The cooled reaction mixture was diluted with ethyl acetate (150 mL) and water (50 mL) and the layers separated. The organic layer was washed with saturated brine (50 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure. Purification of the residue on an Interchim automated system (330 g silica gel cartridge), eluting with a gradient of 30-50% ethyl acetate in heptanes, gave 9-(4,5-dimethylpyridin-2-yl)-6-methylphenanthridine (7.3 g, 88% yield) as a white solid.
Device Performance Results
Compounds used:
IrLA117(LB186)2
All example devices were fabricated by high vacuum (<10-7 Torr) thermal evaporation. The anode electrode was 800 Å of indium tin oxide (ITO). The cathode consisted of 1000 Å of Al. All devices were encapsulated with a glass lid sealed with an epoxy resin in a nitrogen glove box (<1 ppm of H2O and O2) immediately after fabrication, and a moisture getter was incorporated inside the package. The organic stack of the device examples consisted of sequentially, from the ITO surface, 100 Å of HATCN as the hole injection layer (HIL); 400 Å of HTL-1 as the hole transporting layer (HTL); 50 Å of EBL-1 as the electron blocking layer; 400 Å of an emissive layer (EML) comprising 12% of the dopant in a host comprising a 60/40 mixture of Host-1 and Host-2; 350 Å of Liq doped with 35% of ETM-1 as the ETL; and 10 Å of Liq as the electron injection layer (EIL).
Upon fabrication, the electroluminescence (EL) and current density-voltage-luminance (JVL) performance of the devices was measured. The device lifetimes were evaluated at a current density of 80 mA/cm2. The device data is summarized in Table 1 and demonstrates that the dopants of the present invention afford green emitting devices with excellent stability.
It is 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 deviating from the spirit of the invention. The present invention as claimed may therefore include variations from the particular examples and preferred embodiments described herein, as will be apparent to one of skill in the art. It is understood that various theories as to why the invention works are not intended to be limiting.
This application is a continuation of copending U.S. application Ser. No. 16/259,049, filed Jan. 28, 2019, which claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62/628,432, filed Feb. 9, 2018, the entire contents of which are incorporated herein by reference.
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| Number | Date | Country | |
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| 20220238812 A1 | Jul 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| 62628432 | Feb 2018 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16259049 | Jan 2019 | US |
| Child | 17713357 | US |
