Organic electroluminescent materials and devices

Abstract

The invention relates to organic electroluminescent materials and devices. Organometallic compounds comprising a central metal atom coordinated by an at least tetradentate ligand comprising at least one 5-membered ring fused to at least one 6-membered ring are provided. Formulations comprising these organometallic compounds are also provided. Organic light emitting devices (OLED) and related consumer products utilizing these organometallic compounds are also provided.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63 / 643,502, filed May 7, 2024, and U.S. Provisional Application No. 63 / 657,165, filed June 7, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates generally to organic or metal-coordination compounds and formulations and various uses thereof, including as emitters, sensitizers, charge transporters, or exciton transporters in devices such as organic light emitting diodes and related electronic devices and consumer products. BACKGROUND

[0004] Opto-electronic devices that make use of organic materials are becoming increasingly important 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 to be lower cost than alternative devices that use expensive materials. In addition, the inherent properties of organic materials, such as their flexibility, can 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, organic

[0005] 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 the

[0006] One application for emissive molecules is a full color display. Industry standards for such displays require appropriate red, green, and blue pixels. Specifically, these standards require pixels that emit at a wavelength of 625 nm, 535 nm, and 450 nm, respectively. Red, green, and blue OLEDs can be fabricated to produce these emission wavelengths, or nano-structures having these emission wavelengths can be obtained using quantum dot sheets, as described herein. SUMMARY

[0007] In one aspect, the present disclosure provides a compound comprising a structure of Formula I:

[0008]

[0009] wherein X 1 -X3 Each can be either C or N independently;

[0010] Where Y 2 and Y 3 Each of the following groups is independently selected: O, N, S, Se, BR, CR, CRR', NR, PR, PRR', AsRR', CRR', SiRR', and GeRR';

[0011] Where Y 1 Choose from the following groups: O, N, S, Se, BR, CR, CRR', NR, PR, PRR', AsRR', CRR', SiRR', and GeRR';

[0012] Z 1 Z 2 Z 3 and Z 4 Each can be independently C, CR, CRR', O, OR, N, or NR;

[0013] Where K 1 and K 2 Each can be independently selected from the following groups: direct key, O, S, N(R) α ), P(R α ), B(R) α ), C(R α (R) β ) and Si(R α (R) β );

[0014] Among them G 1 G 2 and G 3 Each group is independently selected from the groups consisting of CR, CRR', N, and NR;

[0015] Where n is 1, 2, 3 or 4;

[0016] Where R A Indicates single substitution up to the maximum permissible substitution or no substitution;

[0017] Each R α R β , R, R' and R A Independently, it is hydrogen or a substituent selected from the group consisting of: deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silalkyl, germanalkyl, boranalkyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphinyl and combinations thereof;

[0018] in represents a single or double bond;

[0019] wherein M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Pd, Ag, Au, and Cu;

[0020] wherein M can coordinate to other ligands;

[0021] wherein the compound can engage with other ligands to constitute a penta- or hexadentate ligand; and

[0022] wherein any two substituents can engage or fuse to form a ring.

[0023] In another aspect, the disclosure provides a formulation of a compound as described herein.

[0024] In yet another aspect, the disclosure provides an OLED having an organic layer comprising a compound as described herein.

[0025] In yet another aspect, the disclosure provides a consumer product comprising an OLED having an organic layer comprising a compound as described herein. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 An organic light emitting device is shown.

[0027] Figure 2 An inverted organic light emitting device without a separate electron transport layer is shown. DETAILED DESCRIPTION

[0028] A. Terminology

[0029] The following terms as used herein are defined as follows, unless otherwise specified:

[0030] As used herein, "top" means farthest from the substrate, and "bottom" means closest to the substrate. Where a first layer is described as "disposed on" a second layer, the first layer is disposed farther from the substrate than the second layer. Unless stated that the first layer is "in contact with" the second layer, there can be intervening layers between the first and second layers. For example, a cathode can be described as "disposed on" an anode even though various organic layers are between the cathode and the anode.

[0031] As used herein, "solution processible" means capable of being dissolved, dispersed, or transported in and / or deposited from a liquid medium, either in solution or suspension form.

[0032] As used herein, and as will be generally understood by one of ordinary skill 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 a negative energy with respect to the vacuum energy level, a higher HOMO energy level corresponds to a smaller absolute value of IP (a less negative IP). Similarly, a higher LUMO energy level corresponds to a smaller absolute value of electron affinity (EA) (a less negative EA). On a conventional energy level diagram with the vacuum energy level at the top, a LUMO energy level of a material is higher than a HOMO energy level of the same material. A "higher" HOMO or LUMO energy level is thus represented by a more positive number on such a diagram, as it is closer to the top of the diagram.

[0033] As used herein, and as will be generally understood by one of ordinary skill in the art, a first work function has a "greater than" or "higher than" a second work function if the first work function has a higher absolute value. Since work functions are typically measured as negative numbers relative to the vacuum energy level, this means that a "higher" work function is more negative. On a conventional energy level diagram with the vacuum energy level at the top, a "higher" work function is thus illustrated as being further away from the vacuum energy level in the downward direction. Thus, the definitions of HOMO and LUMO energy levels follow different conventions than work functions.

[0034] Layers, materials, regions, and devices can be described herein with reference to the color of light emitted thereby. Generally, as used herein, an emissive region described as producing a particular color of light can include one or more emissive layers disposed in a stacked manner over one another.

[0035] As used herein, "NIR," "red," "green," "blue," "yellow" layers, materials, regions, or devices refer to layers, materials, regions, or devices that emit light in the wavelength range of about 700-1500 nm, 580-700 nm, 500-600 nm, 400-500 nm, 540-600 nm, respectively, or layers, materials, regions, or devices that have the highest emission spectrum peak in the corresponding wavelength region. In some arrangements, separate regions, layers, materials, or devices can provide separate "deep blue" and "light blue" emissions. As used herein, "deep blue" emission component refers to an emission with a peak emission wavelength that is at least about 4 nm less than the peak emission wavelength of a "light blue" emission component. Typically, the peak emission wavelength of a "light blue" emission component is in the range of about 465-500 nm, and the peak emission wavelength of a "deep blue" emission component is in the range of about 400-470 nm, although these ranges can vary for some configurations.

[0036] In some arrangements, color shifting layers are provided that convert, modify, or change the color of light emitted by another layer to an emission with a different wavelength. Such color shifting layers can be configured to shift the wavelength of light emitted by another layer by a defined amount, as measured by the difference in wavelength of the emitted light and the wavelength of the resulting light. Generally, there are two classes of color changing layers: color filters that modify the spectrum by removing light of non-desired wavelengths, and color shifting layers that convert higher energy photons to lower energy. For example, there can be a "red" filter in order to filter input light to remove light with wavelengths outside the range of about 580-700 nm. A "component" of "color" refers to a component that, when activated or used, produces or otherwise emits light with a particular color as previously described. For example, "a first emission region of a first color" and "a second emission region of a second color different from the first color" describe two emission regions that emit two different colors as previously described when activated within a device.

[0037] As used herein, emission materials, layers, and regions can be distinguished from one another and from other structures based on the light that the material, layer, or region initially produces versus the light that the same or different structure ultimately emits. Initial light production is typically the result of an energy level change that results in photon emission. For example, an organic emission material can initially produce blue light, which can be converted to red or green light by a color filter, quantum dot, or other structure, such that the complete emission stack or sub-pixel emits red or green light. In this case, the initial emission material, region, or layer can be referred to as a "blue" component, even though the sub-pixel is a "red" or "green" component.

[0038] In some cases, it can be preferable to describe the color of components, such as the color of emissive regions, sub-pixels, color shifting layers, etc., in terms of 1931 CIE coordinates. For example, a yellow emissive material can have multiple peak emission wavelengths, one in or near the edge of the "green" region, and one within or near the edge of the "red" region, as previously described. Thus, as used herein, each color term also corresponds to a shape in the 1931 CIE coordinate color space. Shapes in the 1931 CIE color space are constructed by tracing the locus between two color points and any other interior point. For example, the interior shape parameters for red, green, blue, and yellow can be defined as follows:

[0039]

[0040] The terms "halo," "halogen," and "halide" are used interchangeably and refer to fluorine, chlorine, bromine, and iodine.

[0041] The term "acyl" refers to a substituted carbonyl (-C(O)-R s ).

[0042] The term "ester" refers to a substituted oxycarbonyl (-0-C(0)-R s or -C(0)-0-R s ) group.

[0043] The term "ether" refers to an -OR s group.

[0044] The terms "sulfanyl" or "sulfide" are used interchangeably and refer to an -SR s group.

[0045] The term "selenoalkyl" refers to an -SeR s group.

[0046] The term "sulfinyl" refers to an -S(0)-R s group.

[0047] The term "sulfonyl" refers to an -SO2-R s group.

[0048] The term "phosphino" refers to a group containing at least one phosphorus atom bonded to the rest of the molecule. Common examples of phosphino groups include, but are not limited to, groups such as -P(R s )2groups, or -PO(R s )2groups, where each R s may be the same or different.

[0049] The term "silyl" refers to a group containing at least one silicon atom bonded to the rest of the molecule. Common examples of silyl groups include, but are not limited to, groups such as -Si(R s)3group, where each R s may be the same or different.

[0050] The term "germyl" refers to a group containing at least one germanium atom bonded to the relevant structure. Common examples of germyl groups include, but are not limited to, groups such as -Ge(R s )3group, where each R s may be the same or different.

[0051] The term "boronyl" refers to a group containing at least one boron atom bonded to the relevant structure. Common examples of boronyl groups include, but are not limited to, groups such as -B(R s )2group or its Lewis adduct -B(R s )3group, where R s may be the same or different.

[0052] In each of the above, R s may be hydrogen or a substituent selected from the group consisting of the generic substituents as defined in this application. Preferably, R s is selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, and combinations thereof. More preferably, R s is selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.

[0053] The term "alkyl" refers to and includes both straight- and branched-chain alkyl groups having an alkyl carbon atom bonded to the rest of the molecule. Preferred alkyl groups are alkyl groups containing from 1 to 15 carbon atoms, preferably from 1 to 9 carbon atoms, and include methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, t-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1,3-dimethylpropyl, 1,1-dimethylpropyl, 2-ethylpropyl, 1,2-dimethylpropyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, n-heptyl, 2-methylhexyl, 3-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 3,3-dimethylpentyl, 3-ethylpentyl, 2,2,3-trimethylbutyl, and the like. Additionally, the alkyl group can be further substituted.

[0054] The term "cycloalkyl" means and includes both monocyclic, polycyclic, and spirocyclic alkyl groups having ring carbon atoms bonded to the relevant structure. Preferred cycloalkyl groups are cycloalkyl groups containing 3 to 12 ring carbon atoms and include cyclopropyl, cyclopentyl, cyclohexyl, bicyclo[3.1.1]heptyl, spiro[4.5]decyl, spiro[5.5]undecyl, adamantyl, and the like. Additionally, the cycloalkyl group can be further substituted.

[0055] The terms "heteroalkyl" or "heterocycloalkyl" mean and include alkyl or cycloalkyl groups, 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, Ge, and Se, preferably O, S, or N. Additionally, the heteroalkyl or heterocycloalkyl group can be further substituted.

[0056] The term "alkenyl" means and includes both straight-chain and branched-chain alkenyl groups. An alkenyl group is essentially an alkyl group including at least one carbon-carbon double bond in the alkyl chain, where one carbon atom comes from the carbon-carbon double bond bonded to the relevant structure. A cycloalkenyl group is essentially a cycloalkyl group including at least one carbon-carbon double bond in the cycloalkyl ring. As used herein, the term "heteroalkenyl" means an alkenyl group 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, Ge, 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 can be further substituted.

[0057] The term "alkynyl" means and includes both straight-chain and branched-chain alkynyl groups. An alkynyl group is essentially an alkyl group including at least one carbon-carbon triple bond in the alkyl chain, where one carbon atom comes from the carbon-carbon triple bond bonded to the relevant structure. Preferred alkynyl groups are alkynyl groups containing two to fifteen carbon atoms. Additionally, the alkynyl group can be further substituted.

[0058] The terms "aralkyl" or "arylalkyl" are used interchangeably and mean an aryl-substituted alkyl group having an alkyl carbon atom bonded to the relevant structure. Additionally, the aralkyl group can be further substituted.

[0059] The term "heterocyclyl" means and includes both aromatic and non-aromatic ring groups containing at least one heteroatom. Optionally, the at least one heteroatom is selected from O, S, Se, N, P, B, Si, Ge, and Se, preferably O, S, N, or B. Heteroaromatic ring groups are used interchangeably with heteroaryl groups. Preferred non-aromatic heterocyclyl groups are non-aromatic heterocyclyl groups containing 3 to 10 ring atoms, preferably non-aromatic heterocyclyl groups containing 3 to 7 ring atoms including at least one heteroatom, and include cyclic amines such as morpholinyl, piperidinyl, pyrrolidinyl, and the like, and cyclic ethers / sulfides such as tetrahydrofuran, tetrahydropyran, tetrahydrothiophene, and the like. Additionally, the heterocyclyl group can be further substituted or fused.

[0060] The term "aryl" means and includes both monocyclic and polycyclic aromatic hydrocarbon groups. Polycyclic can have two or more rings, where two carbons are common to two adjoining rings (the rings are "fused"). Preferred aryl groups are aromatic groups containing six to thirty carbon atoms, preferably six to twenty-four carbon atoms, six to eighteen carbon atoms, and more preferably six to twelve carbon atoms. Especially preferred are aryl groups having six carbons, ten carbons, twelve carbons, fourteen carbons, or eighteen carbons. Suitable aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, pyrene, chrysene, phenanthrene, perylene, perylene, and azulene, preferably phenyl, biphenyl, terphenyl, triphenylene, and naphthalene. Additionally, aryl groups can be further substituted or fused, such as, but not limited to, fluorene.

[0061] The term "heteroaryl" means and includes both monocyclic aromatic groups and polycyclic aromatic ring systems having at least one heteroatom. Heteroatoms include, but are not limited to, O, S, Se, N, P, B, Si, Ge, and Se. In many cases, O, S, N, or B are preferred heteroatoms. Monocyclic heteroaromatic systems are preferably monocyclic rings having 5 or 6 ring atoms, and the ring can have one to six heteroatoms. Polycyclic heteroaromatic ring systems can have two or more aromatic rings, where two atoms are common to two adjoining rings (the rings are "fused"), where at least one of the rings is a heteroaryl group. Polycyclic heteroaromatic ring systems can have one to six heteroatoms in each ring of the polycyclic aromatic ring system. Preferred heteroaryl groups are aromatic groups containing three to thirty carbon atoms, preferably three to twenty-four carbon atoms, three to eighteen carbon atoms, and more preferably three to twelve carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolo-dipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indooxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthridine, phthalazine, pteridine, xanthene, acridine, phenoxazine, phenothiazine, phenoxazine, benzofuro-pyridine, furanodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, selenophenodipyridine, azaborine, borataborazine, 5λ 2 ,9λ 2 -diaza-13b-borannulene, 5λ 2- benzo[d]benzo[4,5]imidazo[3,2-a]imidazole and 5,9-dioxa-13b- boranaphtho[3,2,1-de]anthracene; preferably dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, pyrazine, pyrimidine, triazine, benzimidazole, 5λ 2 ,9λ 2 - diaza-13b-boranaphtho[2,3,4-de]anthracene, 5λ 2 - benzo[d]benzo[4,5]imidazo[3,2-a]imidazole and 5,9-dioxa-13b- boranaphtho[3,2,1-de]anthracene. Additionally, the heteroaryl group can be further substituted or fused.

[0062] Among the aryl and heteroaryl groups listed above, triphenylene, naphthalene, anthracene, dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, pyrazine, pyrimidine, triazine, benzimidazole, 5λ 2 ,9λ 2 - diaza-13b-boranaphtho[2,3,4-de]anthracene, 5λ 2 - benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b- boranaphtho[3,2,1-de]anthracene, and their respective aza analogs are of particular interest.

[0063] In many instances, the generic substituents are selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, selenoalkyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

[0064] In some instances, preferred generic substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, thio, and combinations thereof.

[0065] In some instances, more preferred generic substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, aryl, heteroaryl, nitrile, thio, and combinations thereof.

[0066] In some instances, even more preferred generic substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, silyl, aryl, heteroaryl, nitrile, and combinations thereof.

[0067] In other cases, the most preferred general substituent is selected from the group consisting of: deuterium, alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.

[0068] The terms "substituted" and "substituted" refer to substituents other than H being bonded to the relevant position, such as carbon or nitrogen. For example, when R... 1 When representing a single substitution, then an R 1 It must not be H (i.e., substitution). Similarly, when R 1 When representing disubstituted substitution, then the two Rs 1 It must not be H. Similarly, when R... 1 When R represents zero or no substitution, 1 For example, it could be hydrogen atoms with all available valences in the ring atom, such as carbon atoms in benzene and nitrogen atoms in pyrrole, or simply none for ring atoms with fully saturated valences, such as nitrogen atoms in pyridine. The maximum possible number of substitutions in a ring structure will depend on the total number of available valences in the ring atoms.

[0069] As used herein, “combination thereof” means that one or more members of the applicable list are combined to form a known or chemically stable arrangement that can be conceived by one of ordinary skill in the art from the applicable list. For example, alkyl and deuterium can be combined to form partially or fully deuterated alkyl groups; halogen and alkyl groups can be combined to form haloalkyl substituents; and halogen, alkyl, and aryl groups can be combined to form haloaralkyl groups. In one instance, the term substitution includes a combination of two to four 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 substituents are combinations containing up to fifty atoms that are not hydrogen or deuterium, or combinations containing up to forty atoms that are not hydrogen or deuterium, or combinations containing up to thirty atoms that are not hydrogen or deuterium. In many cases, preferred combinations of substituents will include up to twenty atoms that are not hydrogen or deuterium.

[0070] The term "aza" in the phrases used herein, namely aza-dibenzofuran, aza-dibenzothiophene, etc., refers to the substitution of one or more CH groups in the corresponding aromatic ring by a nitrogen atom. For example, and without limitation, azatriphenylene covers dibenzo[f,h]quinoxaline and dibenzo[f,h]quinoline. Other nitrogen analogs of the aza-derived compounds described above will be readily contemplated by those skilled in the art, and all such analogs are intended to be covered by the terminology set forth herein.

[0071] 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. Patent No. 8,557,400, Patent Publication No. WO 2006 / 095951, and U.S. Patent Application Publication No. US2011 / 0037057, which are incorporated herein by reference in their entirety, describe the preparation 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. (Review) 2007, 46, 7744-65, which are incorporated by reference in their entirety, describing efficient ways of deuterating methylene hydrogens in benzyl amines and replacing aromatic ring hydrogens with deuterium, respectively.

[0072] As used herein, any specifically listed substituent, such as but not limited to methyl, phenyl, pyridyl, and the like, includes its non-deuterated, partially deuterated, as well as fully deuterated forms. Similarly, classes of substituents such as but not limited to alkyl, aryl, cycloalkyl, heteroaryl, and the like, also include their non-deuterated, partially deuterated, as well as fully deuterated forms. Unless otherwise specified, no atom in a chemical structure that has a valence of H or D completely filled should be considered to include its non-deuterated, partially deuterated, and fully deuterated forms. For example, a chemical structure means to include C6H6, C6D6, C6H3D3, and any other partially deuterated variant thereof. Some common base partially or fully deuterated groups include, but are not limited to, CD3, CD2C(CH3)3, C(CD3)3, and C6D5.

[0073] It should be understood that when a fragment of a molecule 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, dibenzofuryl) or as if it were a whole molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, these different ways of naming substituents or attached fragments are considered equivalent.

[0074] In some cases, a pair of substituents in a molecule can optionally be joined or fused to form a ring. Preferred rings are five- to nine-membered carbocyclic or heterocyclic rings, including both cases where the portion of the ring formed by the pair of substituents is saturated and where the portion of the ring formed by the pair of substituents is unsaturated. In still other cases, a pair of adjacent substituents can optionally be joined or fused to form a ring. As used herein, "adjacent" means that the two substituents involved can be next to each other on the same ring, or on two adjacent rings having the two closest available substitutable positions (such as the 2,2' positions in a biphenyl or the 1,8 positions in a naphthalene).

[0075] B. Compounds of the Disclosure

[0076] In one aspect, the present disclosure provides a compound comprising the structure of Formula I:

[0077]

[0078] wherein X 1 -X 3 each independently is C or N;

[0079] wherein Y 2 and Y 3 each independently is selected from the group consisting of O, N, S, Se, BR, CR, CRR’, NR, PR, PRR’, AsRR’, CRR’, SiRR’, and GeRR’;

[0080] wherein Y 1 is selected from the group consisting of O, N, S, Se, BR, CR, CRR’, NR, PR, PRR’, AsRR’, CRR’, SiRR’, and GeRR’;

[0081] wherein Z 1 , Z 2 , Z 3 , and Z 4 each independently is C, CR, CRR’, O, OR, N, or NR;

[0082] wherein K 1 and K 2 each independently is selected from the group consisting of a direct bond, O, S, N(R α ), P(R α ), B(R α ), C(R α )(R β ), and Si(R α )(R β );

[0083] wherein G 1 , G 2 , and G 3 each independently is selected from the group consisting of CR, CRR’, N, and NR;

[0084] wherein n is 1, 2, 3, or 4;

[0085] wherein R A represents mono-substitution to the maximum allowable substitution or no substitution;

[0086] wherein each R α , R β , R, R’, and R Aindependently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof;

[0087] wherein represents a single or double bond;

[0088] wherein M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Pd, Ag, Au, and Cu;

[0089] wherein M can be coordinated to other ligands;

[0090] wherein the compound can be joined with other ligands to constitute a penta- or hexadentate ligand; and

[0091] wherein any two substituents can be joined or fused to form a ring.

[0092] In some embodiments, if K 1 and K 2 are not a direct bond, and n is 1, then X 3 and Y 2 and Y 2 and Y 3 do not both constitute a cyclic group.

[0093] In some embodiments, the compound is not:

[0094]

[0095] In some embodiments, the compound consists essentially of Formula I.

[0096] In some embodiments, the compound has the structure of Formula I.

[0097] The dashed lines in Formula I can or can not be present. Thus, represents a single or double bond. In some embodiments, multiple dashed lines can be present alternately in each ring, i.e., there are alternating single and double bonds in such a ring. This alternation of single and double bonds can ensure the aromaticity of the corresponding ring.

[0098] In some embodiments, R α , R β , R, R', and R Aeach of X, Y, and Z is independently hydrogen or a substituent selected from the group consisting of deuterium, fluoro, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, thio, and combinations thereof.

[0099] In some embodiments, when K 2 is O and K 1 is a direct bond, then Y 3 , Z 2 , and G 2 do not consist of a 5-membered heterocyclic ring, and Y 2 and Y 3 do not consist of a 6-membered carbon ring fused to the 5-membered heterocyclic ring comprising Y 3 , Z 2 , and G 2 .

[0100] In some embodiments, at least one of X 1 -X 3 is N.

[0101] In some embodiments, X 1 is N.

[0102] In some embodiments, X 2 is N.

[0103] In some embodiments, X 3 is N.

[0104] In some embodiments, X 1 -X 3 are both C.

[0105] In some embodiments, Y 1 is NR.

[0106] In some embodiments, Y 1 is NR, and R in NR comprises a 6-membered aromatic ring.

[0107] In some embodiments, Y 1 is NR, and R in NR comprises a 6-membered carbocyclic aromatic ring.

[0108] In some embodiments, Y 1 is N.

[0109] In some embodiments, Y 2 is N.

[0110] In some embodiments, Y 3 is N.

[0111] In some embodiments, Y 2and Y 3 Both are C.

[0112] In some embodiments, Z 1 -Z 4 At least one of them is N.

[0113] In some embodiments, Z 1 -Z 4 At least two of them are N.

[0114] In some embodiments, Z 1 -Z 4 Two of them are N.

[0115] In some embodiments, Z 1 and Z 2 It is N.

[0116] In some embodiments, K 1 and K 2 At least one of them is not a direct bond.

[0117] In some embodiments, K 1 and K 2 One of them is not a direct key.

[0118] In some embodiments, K 1 and K 2 None of them are direct keys.

[0119] In some embodiments, K 1 and K 2 At least one of them is O.

[0120] In some embodiments, K 1 and K 2 One of them is exactly O.

[0121] In some embodiments, K 1 and K 2 All are O.

[0122] In some embodiments, K 1 and K 2 They are all direct keys.

[0123] In some embodiments, n is 1.

[0124] In some embodiments, n is 2.

[0125] In some embodiments, n is 3.

[0126] In some embodiments, n is 4.

[0127] In some embodiments, G 1G is N. 3 at least one of G

[0128] In some embodiments, G 1 is N.

[0129] In some embodiments, G 2 is N.

[0130] In some embodiments, G 3 is N.

[0131] In some embodiments, G 1 G is C. 3 G is C.

[0132] In some embodiments, M is Pt.

[0133] In some embodiments, M is Pd.

[0134] In some embodiments, M is Ir.

[0135] In some embodiments, the compound comprises at least one tert-butyl or isopropyl group.

[0136] In some embodiments, the compound comprises at least two tert-butyl or isopropyl groups.

[0137] In some embodiments of Formula I, at least one R, R', R α , R β , R A , R B , R C , R D , R E , R F , or R G is partially or fully deuterated. In some embodiments, at least one R A is partially or fully deuterated. In some embodiments, at least one R B is partially or fully deuterated. In some embodiments, at least one R C is partially or fully deuterated. In some embodiments, at least one R D is partially or fully deuterated. In some embodiments, at least one R E is partially or fully deuterated. In some embodiments, at least one R F is partially or fully deuterated. In some embodiments, at least one R G is partially or fully deuterated. In some embodiments, at least one of R or R' is partially or fully deuterated. In some embodiments, at least one of R α or R β is partially or fully deuterated.

[0138] In some embodiments, at least one of R, R', R α , R β , R A , R B , R C , R D , R E , R F , or R G is a substituent selected from the group of general substituents defined herein. In some embodiments, at least one of R or R' is selected from the group of general substituents defined herein. In some embodiments, at least one of R α or R β is selected from the group of general substituents defined herein. In some embodiments, at least one R A is selected from the group of general substituents defined herein. In some embodiments, at least one R B is selected from the group of general substituents defined herein. In some embodiments, at least one R C is selected from the group of general substituents defined herein. In some embodiments, at least one R D is selected from the group of general substituents defined herein. In some embodiments, at least one R E is selected from the group of general substituents defined herein. In some embodiments, at least one R F is selected from the group of general substituents defined herein. In some embodiments, at least one R G is selected from the group of general substituents defined herein.

[0139] In some embodiments, at least one of R, R', R α , R β , R A , R B , R C , R D , R E , R F , or R G is a substituent selected from the group of preferred general substituents defined herein. In some embodiments, at least one of R or R' is selected from the group of preferred general substituents defined herein. In some embodiments, at least one of R α or R β is selected from the group of preferred general substituents defined herein. In some embodiments, at least one R A is selected from the group of preferred general substituents defined herein. In some embodiments, at least one R Bis selected from the group consisting of preferred general substituent groups defined herein. In some embodiments, at least one R C is selected from the group consisting of preferred general substituent groups defined herein. In some embodiments, at least one R D is selected from the group consisting of preferred general substituent groups defined herein. In some embodiments, at least one R E is selected from the group consisting of preferred general substituent groups defined herein. In some embodiments, at least one R F is selected from the group consisting of preferred general substituent groups defined herein. In some embodiments, at least one R G is selected from the group consisting of preferred general substituent groups defined herein.

[0140] In some embodiments, the compound comprises a structure selected from the group consisting of structures from List 1 below:

[0141]

[0142]

[0143]

[0144] wherein moieties B, C, D, E, F, G, and H are each independently a monocyclic ring comprising one 5- to 10-membered carbocyclic or heterocyclic ring, or a polycyclic fused ring system comprising at least two fused 5- to 10-membered carbocyclic or heterocyclic rings;

[0145] wherein each R B , R C , R D , R E , R F , R G , and R H represents mono-substitution to the maximum allowable substitution or no substitution; and

[0146] wherein each R B , R C , R D , R E , R F , R G , and R H is independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof.

[0147] In some embodiments, R A , RB R C R D R E R F R G and R H At least one of them is independently selected from the following groups:

[0148]

[0149]

[0150] Q A Q B Q C Q D and Q E Each of these terms independently represents a single substitution up to the maximum permissible substitution or no substitution;

[0151] Each Q A Q B Q C Q D Q E Q A1 Q B1 Q C1 Q D1 and Q E1 Independently, it is hydrogen or a substituent selected from the group consisting of: alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, boronalkyl, aralkyl, alkoxy, aryloxy, amino, silalkyl, germanalkyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphinyl, selenyl and combinations thereof;

[0152] Each Y aa and Y bb The substituents are independently selected from the group consisting of: direct bond, BR, BRR', NR, PR, O, S, Se, C=O, C=S, C=Se, C=NR, C=CRR', S=O, SO2, CR, CRR', SiRR', GeRR', alkyl, cycloalkyl, aryl, heteroaryl and combinations thereof; and any two substituents may be joined or fused to form a ring.

[0153] In some embodiments, each of B, C, D, E, F, G, and H can each independently be selected from the group consisting of benzene, pyridine, pyrimidine, pyridazine, pyrazine, triazine, imidazole, pyrazole, pyrrole, oxazole, furan, thiophene, thiazole, triazole, naphthalene, quinoline, isoquinoline, quinazoline, benzofuran, azabenzofuran, benzoxazole, azabenzoxazole, benzothiophene, azabenzothiophene, benzothiazole, azabenzothiazole, benzoselenophene, azabenzoselenophene, indene, azaindene, indole, azaindole, benzimidazole, azabenzimidazole, carbazole, azacarbazole, diphenylene furan, azadiphenylene furan, diphenylene thiophene, azadiphenylene thiophene, quinoxaline, phthalazine, phenanthrene, azaphenanthrene, anthracene, azanthracene, phenanthridine, fluorene, and azafiuorene.

[0154] In some embodiments, the compound comprises an electron-withdrawing group. In some embodiments, the Hammett constant of the electron-withdrawing group is greater than 0. In some embodiments, the Hammett constant of the electron-withdrawing group is equal to or greater than 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, or 1.1.

[0155] In some embodiments, the compound selected from List 1 comprises an electron- withdrawing group selected from the group consisting of the following EWG1 List: F, CF3, CN, COCH3, CHO, COCF3, COOMe, COOCF3, NO2, SF3, SiF3, PF4, SF5, OCF3, SCF3, SeCF3, SOCF3, SeOCF3, SO2F, SO2CF3, SeO2CF3, OSeO2CF3, OCN, SCN, SeCN, NC, + N(R k2 )3, (R k2 )2CCN, (R k2 )2CCF3, CNC(CF3)2, BR k3 R k2 , substituted or unsubstituted diphenylene borol, 1 -substituted carbazole, 1,9-substituted carbazole, substituted or unsubstituted carbazole, substituted or unsubstituted pyridine, substituted or unsubstituted pyrimidine, substituted or unsubstituted pyrazine, substituted or unsubstituted pyridoxal, substituted or unsubstituted triazine, substituted or unsubstituted oxazole, substituted or unsubstituted benzoxazole, substituted or unsubstituted thiazole, substituted or unsubstituted benzothiazole, substituted or unsubstituted imidazole, substituted or unsubstituted benzimidazole, ketone, carboxylic acid, ester, nitrile, isonitrile, sulfinyl, sulfonyl, partially and fully fluorinated alkyl, partially and fully fluorinated aryl, partially and fully fluorinated heteroaryl, cyano-containing alkyl, cyano-containing aryl, cyano-containing heteroaryl, isocyanate,

[0156] wherein each R k1 represents mono-substitution to the maximum allowable substitution or no substitution;

[0157] wherein Y G is selected from the group consisting of: BR e , NR e , PR e , O, S, Se, C=0, S=0, S02, CR e R f , SiR e R f , and GeR e R f ; and

[0158] each of R k1 , R k2 , R k3 , R e , and R f is independently hydrogen or a substituent selected from the group consisting of the generic substituents defined herein.

[0159] In some embodiments, the compound comprises an electron- withdrawing group selected from the group consisting of the following list of structures of EWG2

[0160] In some embodiments, the compound comprises an electron- withdrawing group selected from the group consisting of the following list of structures of EWG3:

[0161] In some embodiments, the compound comprises an electron- withdrawing group selected from the group consisting of the following list of structures of EWG4:

[0162] In some embodiments, the compound comprises an electron- withdrawing group, which is a π-electron deficient electron- withdrawing group. In some embodiments, the π-electron deficient electron- withdrawing group is selected from the group consisting of the following list of structures of π-EWG: CN, COCH3, CHO, COCF3, COOMe, COOCF3, N02, SF3, SiF3, PF4, SF5, OCF3, SCF3, SeCF3, SOCF3, SeOCF3, S02F, S02CF3, Se02CF3, OSe02CF3, OCN, SCN, SeCN, NC, + N(R k2 )3, BRk2 R k3 Substituted or unsubstituted dibenzoboranecyclopentadiene, 1-substituted carbazole, 1,9-substituted carbazole, substituted or unsubstituted carbazole, substituted or unsubstituted pyridine, substituted or unsubstituted pyrimidine, substituted or unsubstituted pyrazine, substituted or unsubstituted pyridazine, substituted or unsubstituted triazine, substituted or unsubstituted oxazole, substituted or unsubstituted benzoxazole, substituted or unsubstituted thiazole, substituted or unsubstituted benzothiazole, substituted or unsubstituted imidazole, substituted or unsubstituted benzimidazole, ketones, carboxylic acids, esters, nitriles, isonitriles, sulfinyl groups, sulfonyl groups, partially and fully fluorinated aryl groups, partially and fully fluorinated heteroaryl groups, cyano-containing aryl groups, cyano-containing heteroaryl groups, isocyanates, The variables are the same as those previously defined.

[0163] In some embodiments, the compound comprises an electron-withdrawing group from the EWG1 list as defined herein. In some embodiments, the compound comprises an electron-withdrawing group from the EWG2 list as defined herein. In some embodiments, the compound comprises an electron-withdrawing group from the EWG3 list as defined herein. In some embodiments, the compound comprises an electron-withdrawing group from the EWG4 list as defined herein. In some embodiments, the compound comprises an electron-withdrawing group from the π-EWG list as defined herein.

[0164] In which the compounds are selected from some embodiments of Listing 1, at least one R A It is or contains an electron-withdrawing group. In some embodiments, at least one R A It is or contains an electron-withdrawing group from the EWG1 list as defined herein. In some embodiments, at least one R A It is or contains an electron-withdrawing group from the EWG2 list as defined herein. In some embodiments, at least one R A It is or contains an electron-withdrawing group from the EWG3 list as defined herein. In some embodiments, at least one R A It is or contains an electron-withdrawing group from the EWG4 list as defined herein. In some embodiments, at least one R A It is or contains electron-withdrawing groups from the list of π-EWG as defined herein.

[0165] In which the compounds are selected from some embodiments of Listing 1, at least one R B It is or contains an electron-withdrawing group. In some embodiments, at least one R B It is or contains an electron-withdrawing group from the EWG1 list as defined herein. In some embodiments, at least one RB is or comprises an electron withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R B is or comprises an electron withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R B is or comprises an electron withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R B is or comprises an electron withdrawing group from the list of π-EWG as defined herein.

[0166] In some embodiments wherein the compound is selected from List 1, at least one R C is or comprises an electron withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one R C is or comprises an electron withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R C is or comprises an electron withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R C is or comprises an electron withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R C is or comprises an electron withdrawing group from the list of π-EWG as defined herein.

[0167] In some embodiments wherein the compound is selected from List 1, at least one R D is or comprises an electron withdrawing group. In some embodiments, at least one R D is or comprises an electron withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one R D is or comprises an electron withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R D is or comprises an electron withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R D is or comprises an electron withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R D is or comprises an electron withdrawing group from the list of π-EWG as defined herein.

[0168] In some embodiments wherein the compound is selected from List 1, at least one R E is or comprises an electron withdrawing group. In some embodiments, at least one R E is or comprises an electron withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one R Eis or comprises an electron-withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R E is or comprises an electron-withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R E is or comprises an electron-withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R E is or comprises an electron-withdrawing group from the list of p-EWG as defined herein.

[0169] In some embodiments where the compound is selected from List 1, at least one R F is or comprises an electron-withdrawing group. In some embodiments, at least one R F is or comprises an electron-withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one R F is or comprises an electron-withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R F is or comprises an electron-withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R F is or comprises an electron-withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R F is or comprises an electron-withdrawing group from the list of p-EWG as defined herein.

[0170] In some embodiments where the compound is selected from List 1, at least one R G is or comprises an electron-withdrawing group. In some embodiments, at least one R G is or comprises an electron-withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one R G is or comprises an electron-withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R G is or comprises an electron-withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R G is or comprises an electron-withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R G is or comprises an electron-withdrawing group from the list of p-EWG as defined herein.

[0171] In some embodiments where the compound is selected from List 1, at least one R H is or comprises an electron-withdrawing group. In some embodiments, at least one R H is or comprises an electron-withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one R His or comprises an electron-withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R H is or comprises an electron-withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R H is or comprises an electron-withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R H is or comprises an electron-withdrawing group from the list of p-EWG as defined herein.

[0172] In some embodiments, at least one of R or R' is or comprises an electron- withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one of R or R' is or comprises an electron-withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one of R or R' is or comprises an electron-withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one of R or R' is or comprises an electron-withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one of R or R' is or comprises an electron-withdrawing group from the list of p-EWG as defined herein.

[0173] In some embodiments, the compound comprises a structure selected from the group consisting of the structures in List 2 below:

[0174]

[0175]

[0176] wherein X 4 -X 19 each independently is C or N; and

[0177] wherein Y 4 and Y 5 each independently is selected from the group consisting of O, N, S, Se, BR, CR, CRR', NR, PR, PRR', AsRR', CRR', SiRR', and GeRR';

[0178] wherein each R AA , R BB , R CC and R DD represents mono-substitution to the maximum allowable substitution or no substitution; and

[0179] wherein each R AA , R BB , R CC and R DDindependently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, boryl, selenoalkyl, and combinations thereof;

[0180] In some embodiments, the compound is selected from List 2, at least one R AA is or comprises an electron-withdrawing group. In some embodiments, at least one R AA is or comprises an electron-withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one R AA is or comprises an electron-withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R AA is or comprises an electron-withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R AA is or comprises an electron-withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R AA is or comprises an electron-withdrawing group from the list of p-EWG as defined herein.

[0181] In some embodiments, the compound is selected from List 2, at least one R BB is or comprises an electron-withdrawing group. In some embodiments, at least one R BB is or comprises an electron-withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one R BB is or comprises an electron-withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R BB is or comprises an electron-withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R BB is or comprises an electron-withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R BB is or comprises an electron-withdrawing group from the list of p-EWG as defined herein.

[0182] In some embodiments, the compound is selected from List 2, at least one R CC is or comprises an electron-withdrawing group. In some embodiments, at least one R CC is or comprises an electron-withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one R CC is or comprises an electron-withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R CCis or comprises an electron withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R CC is or comprises an electron withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R CC is or comprises an electron withdrawing group from the list of π-EWG as defined herein.

[0183] In some embodiments, the compound is selected from List 2, at least one R DD is or comprises an electron withdrawing group. In some embodiments, at least one R DD is or comprises an electron withdrawing group from the list of EWG1 as defined herein. In some embodiments, at least one R DD is or comprises an electron withdrawing group from the list of EWG2 as defined herein. In some embodiments, at least one R DD is or comprises an electron withdrawing group from the list of EWG3 as defined herein. In some embodiments, at least one R DD is or comprises an electron withdrawing group from the list of EWG4 as defined herein. In some embodiments, at least one R DD is or comprises an electron withdrawing group from the list of π-EWG as defined herein.

[0184] In some embodiments, the compound is selected from the group consisting of compounds of formula Ir(L A 1 L y 1 consisting of compounds of formula Ir(L

[0185]

[0186] wherein L A 1 is selected from the group consisting of the following structures from List 3 below:

[0187]

[0188]

[0189] and Ly 1 is selected from the group consisting of the following structures from List 4 below:

[0190]

[0191]

[0192] wherein L and L' are independently selected from the group consisting of:

[0193]

[0194]

[0195] wherein R" is hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof.

[0196] In some embodiments, the compound is selected from the group consisting of compounds of formula Ir(L A 2 L y 2 L

[0197]

[0198] wherein L A 2 is selected from the group consisting of the following structures from List 5 below:

[0199]

[0200]

[0201]

[0202] and L y 2 is selected from the group consisting of the following structures from List 6 below:

[0203]

[0204]

[0205]

[0206] In some embodiments, the compound is selected from the group consisting of compounds of formula Ir(L A 1 L y 1 L

[0207]

[0208] wherein L A 1 is selected from the group consisting of L A 1 -1-(Rq)(Rj)(Rk)(Rl) and LA 1 - W - (Ri)(Rj)(Rk)(Rl) selected from the group consisting of: wherein W is an integer from 2 to 8, wherein i, j, k, l, s, t, u, and v are each independently an integer from 1 to 468, and q is an integer from 2 to 468; and Rq is selected from R2 to R468, each of Ri, Rj, Rk, Rl is independently selected from R1 to R468, wherein L A 1 - 1 - (R2)(R1)(R1)(R1) to L A 1 - 1 - (R468)(R468)(R468)(R468) and L A 1 - 2 - (R1)(R1)(R1)(R1) to L A 1 - 8 - (R468)(R468)(R468)(R468) each of which is defined in the following List 7:

[0209]

[0210]

[0211] wherein Ly 1 is selected from the group consisting of Ly 1 - Q - (Rs)(Rt)(Ru)(Rv) selected from the group consisting of: wherein Q is an integer from 1 to 10, and each of Rs, Rt, Ru, Rv is independently selected from R1 to R468, wherein Ly 1 - 1 - (R1)(R1)(R1)(R1) to Ly 1 - 10 - (R468)(R468)(R468)(R468) each of which is defined in the following List 8:

[0212]

[0213]

[0214] wherein R1 to R468 have the following structures from the following List 9:

[0215]

[0216]

[0217]

[0218]

[0219]

[0220]

[0221]

[0222]

[0223]

[0224]

[0225]

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236] In some embodiments, the compound is selected from the group consisting of compounds of formula Ir(L A 2 L y 2 (L)(L') of formula:

[0237]

[0238] wherein L A 2 is selected from the group consisting of L A 2 -W'-(Ri)(Rj)(Rk)(Rl), where W' is an integer from 1 to 20, each of Ri, Rj, Rk, Rl is independently selected from R1 to R468, wherein L A 2 -1-(R1)(R1)(R1)(R1) to L A2 - each of R468, R468, R468, R468 in -20- is selected from the group consisting of the following structures from List 10:

[0239]

[0240]

[0241]

[0242] wherein Ly 2 is selected from the group consisting of Ly 2 - Q'-(Rs)(Rt)(Ru)(Rv), wherein Q' is an integer from 1 to 13, and each of Rs, Rt, Ru, Rv is independently selected from R1 to R468, wherein Ly 2 - 1-(R1)(R1)(R1)(R1) to Ly 2 - each of R468, R468, R468, R468 in -13- is defined in List 11 below:

[0243]

[0244]

[0245] In some embodiments, the compound is selected from the group consisting of:

[0246]

[0247]

[0248]

[0249] In some embodiments, the compound is selected from the group consisting of compounds having the formula Pt(L A 1 )(Ly 1 ) consisting of:

[0250]

[0251] wherein if L A 1 is selected from the group consisting of structures in List 3, then Ly 1 is selected from the group consisting of structures in List 4; and

[0252] wherein if L A 1 is selected from the group consisting of structures in List 7, then Ly 1is selected from the group consisting of the structures in List 8.

[0253] In some embodiments, the compound is selected from the group consisting of compounds of formula Pt(L A 2 )(Ly 2 ) consisting of:

[0254]

[0255] wherein if L A 2 is selected from the group consisting of the structures in List 5, then Ly 2 is selected from the group consisting of the structures in List 6; and

[0256] wherein if L A 2 is selected from the group consisting of the structures in List 10, then Ly 2 is selected from the group consisting of the structures in List 11.

[0257] In some embodiments, the compound is selected from the group consisting of compounds -G- (Rs)(Rt)(Ru)(Rv), where G is an integer from 1 to 10, and each of Rs, Rt, Ru, Rv is independently selected from R1 to R468, where each of compounds -1- (R1)(R1)(R1)(R1) to -10- (R468)(R468)(R468)(R468) is defined below in List 12:

[0258]

[0259]

[0260] In some embodiments, the compound is selected from the group consisting of:

[0261]

[0262]

[0263]

[0264]

[0265] In some embodiments, each of Part B, Part C, Part D, Part E, Part F, Part G, and Part H can each independently be selected from the group consisting of benzene, pyridine, pyrimidine, pyridazine, pyrazine, triazine, imidazole, pyrazole, pyrrole, oxazole, furan, thiophene, thiazole, triazole, naphthalene, quinoline, isoquinoline, quinazoline, benzofuran, azabenzofuran, benzoxazole, azabenzoxazole, benzothiophene, azabenzothiophene, benzothiazole, azabenzothiazole, benzoselenophene, azabenzoselenophene, indene, azaindene, indole, azaindole, benzimidazole, azabenzimidazole, carbazole, azacarbazole, dibenzofuran, azadibenzofuran, dibenzothiophene, azadibenzothiophene, quinoxaline, phthalazine, phenanthrene, azaphenanthrene, anthracene, azanthracene, phenanthridine, fluorene, and azafiuorene.

[0266] In some embodiments, each of Part B, Part C, Part D, Part E, Part F, Part G, and Part H can independently be a polycyclic fused ring structure. In some embodiments, each of Part B, Part C, Part D, Part E, Part F, Part G, and Part H can independently be a polycyclic fused ring structure comprising at least two fused rings. In some embodiments, the polycyclic fused ring structure has one 6-membered ring and one 5-membered ring. In some such embodiments, the 5-membered ring or the 6-membered ring can coordinate to the metal. In some embodiments, the polycyclic fused ring structure has two 6-membered rings. In some embodiments, each of Part B, Part C, Part D, Part E, Part F, Part G, and Part H can independently be selected from the group consisting of benzofuran, benzothiophene, benzoselenophene, naphthalene, and nitrogen hetero variants thereof.

[0267] In some embodiments, each of Part B, Part C, Part D, Part E, Part F, Part G, and Part H can independently be a polycyclic fused ring structure comprising at least three fused rings. In some embodiments, the polycyclic fused ring structure has two 6-membered rings and one 5-membered ring. In some such embodiments, the 5-membered ring is fused to the ring coordinating to the metal M, and the second 6-membered ring is fused to the 5-membered ring. In some embodiments, each of Part B, Part C, Part D, Part E, Part F, Part G, and Part H can independently be selected from the group consisting of dibenzofuran, dibenzothiophene, dibenzoselenophene, and nitrogen hetero variants thereof. In some such embodiments, each of Part B, Part C, Part D, Part E, Part F, Part G, and Part H can independently be further substituted at the ortho or meta position of the O, S, or Se atom with a substituent selected from the group consisting of deuterium, fluorine, nitrile, alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof. In some such embodiments, the nitrogen hetero variants contain exactly one N atom at the 6-position (ortho to O, S, or Se) and have a substituent at the 7-position (meta to O, S, or Se).

[0268] In some embodiments, each of moiety B, moiety C, moiety D, moiety E, moiety F, moiety G, and moiety H can independently be a polycyclic fused ring structure comprising at least four fused rings. In some embodiments, the polycyclic fused ring structure comprises three 6-membered rings and one 5-membered ring. In some such embodiments, the 5-membered ring is fused to the ring coordinated to the metal M, the second 6-membered ring is fused to the 5-membered ring, and the third 6-membered ring is fused to the second 6-membered ring. In some such embodiments, the third 6-membered ring is further substituted with a substituent selected from the group consisting of deuterium, fluorine, nitrile, alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.

[0269] In some embodiments, each of moiety B, moiety C, moiety D, moiety E, moiety F, moiety G, and moiety H can independently be a polycyclic fused ring structure comprising at least five fused rings. In some embodiments, the polycyclic fused ring structure comprises four 6-membered rings and one 5-membered ring or three 6-membered rings and two 5-membered rings. In some embodiments comprising two 5-membered rings, the 5-membered rings are fused together. In some embodiments comprising two 5-membered rings, the 5-membered rings are separated by at least one 6-membered ring. In some embodiments having one 5-membered ring, the 5-membered ring is fused to the ring coordinated to the metal M, the second 6-membered ring is fused to the 5-membered ring, the third 6-membered ring is fused to the second 6-membered ring, and the fourth 6-membered ring is fused to the third 6-membered ring.

[0270] In some embodiments, each of moiety B, moiety C, moiety D, moiety E, moiety F, moiety G, and moiety H can independently be a nitrogen-aza version of the above polycyclic fused ring. In some such embodiments, each of moiety B, moiety C, moiety D, moiety E, moiety F, moiety G, and moiety H can independently contain exactly one aza N atom. In some such embodiments, at least one of moiety B, moiety C, moiety D, moiety E, moiety F, moiety G, and moiety H contains exactly two aza N atoms, which can be in one ring or in two different rings. In some such embodiments, the ring having the aza N atom is separated from the metal M atom by at least two other rings. In some such embodiments, the ring having the aza N atom is separated from the metal M atom by at least three other rings. In some such embodiments, each of the ortho positions of the aza N atom is substituted.

[0271] In some embodiments, the compounds of Formula I described herein can be at least 30% deuterated, at least 40% deuterated, at least 50% deuterated, at least 60% deuterated, at least 70% deuterated, at least 80% deuterated, at least 90% deuterated, at least 95% deuterated, at least 99% deuterated, or 100% deuterated. As used herein, the percentage deuterated has its ordinary meaning and includes the percentage of all possible hydrogen atoms in the compound that are occupied by deuterium atoms (e.g., the position of hydrogen or deuterium). In some embodiments, the carbon atoms that make up the ring coordinated to the metal M are fully or partially deuterated. In some embodiments, the carbon atoms comprised by the polycyclic system coordinated to the metal M are fully or partially deuterated. In some embodiments, the substituents attached to the monocyclic or fused polycyclic system coordinated to the metal M are fully or partially deuterated.

[0272] In some embodiments, the compounds of Formula I have an emission at room temperature with a full width at half maximum (FWHM) equal to or less than 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5 nm. A narrower FWHM means better color purity for OLED display applications.

[0273] In some embodiments, the compounds can be emissive dopants. In some embodiments, the compounds can produce emission via phosphorescence, fluorescence, thermally activated delayed fluorescence, triplet-triplet annihilation, or a combination of these methods. In some embodiments, the emissive dopants can be racemic mixtures, or can be enriched in one enantiomer. In some embodiments, the compounds of the present application can have different stereoisomers, such as fac and mer. The present compounds refer to individual isomers and mixtures of various isomers in any mixing ratio. In some embodiments, the compounds can be homoleptic (each ligand is the same). In some embodiments, the compounds can be heteroleptic (at least one ligand is different from the others). In some embodiments, when there is more than one ligand coordinated to the metal, the ligands can all be the same. In some other embodiments, at least one ligand is different from the others. In some embodiments, each ligand can be different from all the other ligands. This also holds true for embodiments where the ligands coordinated to the metal are connected to other ligands coordinated to the metal to form a tridentate, tetradentate, pentadentate, or hexadentate ligand. Thus, in cases where the coordinated ligands are connected together, in some embodiments, all the ligands can be the same, and in some other embodiments, at least one of the connected ligands can be different from the others.

[0274] In yet another aspect of the present disclosure, a formulation comprising a novel compound disclosed herein is described. The formulation can include one or more components disclosed herein selected from the group consisting of a solvent, an emitter, a host, a hole injection material, a hole transport material, an electron blocking material, a hole blocking material, and an electron transport material.

[0275] The present disclosure encompasses any chemical structure that comprises a novel compound of the present disclosure or a monovalent or multivalent variant thereof. In other words, a compound of the present invention or a monovalent or multivalent variant thereof can be part of a larger chemical structure. Such chemical structures can be selected from the group consisting of monomers, polymers, macromolecules, and supramolecules (also known as supermolecules). As used herein, “monovalent variant of a compound” refers to the same moiety as the compound, but in which one hydrogen has been removed and replaced with a bond to the rest of the chemical structure. As used herein, “multivalent variant of a compound” refers to the same moiety as the compound, but in which more than one hydrogen has been removed and replaced with one or more bonds to the rest of the chemical structure. In the case of supramolecules, a compound of the present invention can also be incorporated into a supramolecular complex without a covalent bond. As used in this context, a description that structure A comprises part B means that structure A includes the structure of part B, which does not include the H or D atoms that can be attached to part B. This is because at least one of the H or D on a given moiety structure must be replaced with a substituent such that part B can be part of structure A, and after it becomes part of structure A, one or more of the H or D on the given moiety B structure can be further substituted.

[0276] C. OLEDs and devices of the present disclosure

[0277] In another aspect, the present disclosure also provides an OLED device comprising a first organic layer, the first organic layer containing a compound as disclosed in the above compound moieties of the present disclosure.

[0278] In some embodiments, an OLED comprises: an anode; a cathode; and an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a compound described herein.

[0279] In some embodiments, the organic layer is selected from the group consisting of a HIL, a HTL, an EBL, an EML, a HBL, an ETL, and an EIL. In some embodiments, the organic layer can be an emissive layer and the compound as described herein can be an emissive dopant or a non-emissive dopant.

[0280] In some embodiments, the organic layer can further comprise a host, wherein the host comprises at least one chemical group selected from the group consisting of a triphenylene, a carbazole, an indolocarbazole, a dithiophene, a dithiophene, a dithiophene, a 5λ 2- benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-bora- naphtho[3,2,1-de]anthracene, azacyclohexaborane, oxaborabenzene, dihydroacridine, xanthene, dihydrobenzoazasiline, dibenzooxasiline, phenoxazine, phenoxathiine, phenothiazine, dihydrophenoxazine, fluorene, naphthalene, anthracene, phenanthrene, phenanthroline, benzochinoline, quinoline, isoquinoline, quinazoline, pyrimidine, pyrazine, pyridine, triazine, boranyl, silyl, azatriphenylene, azacarbazole, azaindolecarbazole, azadibenzothiophene, azadibenzofuran, azadibenzoselenophene, azacarbazolene-5λ 2 - benzo[d]benzo[4,5]imidazo[3,2-a]imidazole and azacarbazolene-5λ

[0281] In some embodiments, the main group can be selected from the group consisting of the structures of main group 1 below:

[0282]

[0283]

[0284]

[0285]

[0286]

[0287]

[0288]

[0289]

[0290]

[0291] wherein:

[0292] each of J1to J6is independently C or N;

[0293] L' is a direct bond or an organic linking group;

[0294] each Y AA , Y BB , Y CC , and Y DD is independently selected from the group consisting of no bond, a direct bond, O, S, Se, CRR', SiRR', GeRR', NR, BR, BRR'.

[0295] R A' , R B' , R C' , R D' , R E' , R F' , and R G' each independently represents mono-substitution, up to the maximum substitution, or no substitution;

[0296] each R, R', R A' , R B' , R C' , R D' , R E' , R F' , and R G' is independently hydrogen or a substituent selected from the group consisting of the general substituents as defined herein; any two substituents can be joined or fused to form a ring;

[0297] and, where possible, each unsubstituted aromatic carbon atom is optionally replaced with N to form a nitrogen hetero substituted ring.

[0298] In some embodiments, at least one of J1to J3is N. In some embodiments, at least two of J1to J3are N. In some embodiments, all three of J1to J3are N. In some embodiments, each Y CC and Y DD is independently O, S, or SiRR', or more preferably O or S. In some embodiments, at least one unsubstituted aromatic carbon atom is replaced with N to form a nitrogen heterocycle.

[0299] In some embodiments, the host is selected from the group consisting of EG1-MG1-EG1to EG53-MG27-EG53having the formula EGa-MGb-EGc, or EG1-EG1to EG53-EG53having the formula EGa-EGcwhen MGb is absent, wherein a is an integer from 1 to 53, b is an integer from 1 to 27, and c is an integer from 1 to 53. The structures of EG1to EG53are shown below:

[0300]

[0301]

[0302] The structures of MG1to MG27are shown below:

[0303]

[0304]

[0305] In the MGb structures shown above, two bonding positions in the asymmetric structures MG10, MG11, MG12, MG13, MG14, MG17, MG24, and MG25 are labeled with numbers for identification purposes.

[0306] In some embodiments, the host can be any of itsaza-substituted variants, its fully or partially deuterated variants, and combinations thereof. In some embodiments, the host is of the formula EGa-MGb-Egc and is selected from the group consisting of h1 to h112 as defined in the following Host Group 2 list, wherein each of MGb, EGa, and Egc is defined as follows:

[0307]

[0308]

[0309] In the above table, the EGaand EGcstructures bonded to one of the asymmetric structures MG10, MG11, MG12, MG13, MG14, MG17, MG24, and MG25 are annotated with a number prefix that identifies their bonding position in the MGbstructure.

[0310] In some embodiments, the organic layer can further comprise a host, wherein the host comprises a metal complex.

[0311] In some embodiments, the emissive layer can include two hosts: a first host and a second host. In some embodiments, the first host is a hole transport host and the second host is an electron transport host. In some embodiments, the first host is a hole transport host and the second host is a bipolar host. In some embodiments, the first host is an electron transport host and the second host is a bipolar host. In some embodiments, the first host and the second host can form an exciplex. In some embodiments, the emissive layer can include a third host. In some embodiments, the third host is selected from the group consisting of an insulating host (wide band gap host), a hole transport host, and an electron transport host. In some embodiments, the third host forms an exciplex with one of the first host and the second host or with both the first host and the second host. In some embodiments, the emissive layer can include a fourth host. In some embodiments, the fourth host is selected from the group consisting of an insulating host (wide band gap host), a hole transport host, and an electron transport host. In some embodiments, the fourth host forms an exciplex with one of the first host, the second host, and the third host, with two of the first host, the second host, and the third host, or with each of the first host, the second host, and the third host. In some embodiments, the electron transport host has a LUMO less than -2.4 eV, less than -2.5 eV, less than -2.6 eV, or less than -2.7 eV. In some embodiments, the hole transport host has a HOMO higher than -5.6 eV, higher than -5.5 eV, higher than -5.4 eV, or higher than -5.35 eV. HOMO and LUMO values can be determined using solution electrochemistry. Solution cyclic voltammetry and differential pulse voltammetry can be performed using a CH Instruments model 6201B potentiostat, using anhydrous dimethylformamide (DMF) solvent and tetrabutylammonium hexafluorophosphate as a supporting electrolyte. Glassy carbon, platinum wire, and silver wire are used as the working electrode, the counter electrode, and the reference electrode, respectively. The electrochemical potential can be referenced to the internal ferrocene-ferrocenium salt redox couple (Fc / Fc+) by the peak potential difference measured by differential pulse voltammetry.According to the literature ((a) Fink, R.; Heischkel, Y.; Thelakkat, M.; Schmidt, H.-W. Chem. Mater. 1998, 10, 3620-3625; (b) Pommerehne, J.; Vestweber, H.; Guss, W.; Mahrt, R. F.; Bassler, H.; Porsch, M.; Daub, J. Adv. Mater. 1995, 7, 551), the corresponding highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies are determined by the cationic and anionic redox potentials relative to the ferrocenium reference (4.8 eV vs. vacuum).

[0312] In some embodiments, a compound as described herein can be a sensitizer or a component of a sensitizer; wherein the device can further comprise an acceptor that receives energy from the sensitizer. In some embodiments, the acceptor is an emitter in the device. In some embodiments, the acceptor can be a fluorescent material. In some embodiments, a compound described herein can be used as a phosphorescent sensitizer in an OLED, wherein one or more layers in the OLED contain an acceptor in the form of one or more non-delayed fluorescent and / or delayed fluorescent materials. In some embodiments, a compound described herein can be used as one component of an exciplex used as a sensitizer. As a phosphorescent sensitizer, the compound must be able to transfer energy to an acceptor and the acceptor will emit energy or further transfer energy to a final emitter. The acceptor concentration can range from 0.001% to 99.9%. The acceptor can be in the same layer as the phosphorescent sensitizer or in one or more different layers. In some embodiments, the acceptor is a thermally activated delayed fluorescence (TADF) material. In some embodiments, the acceptor is a non-delayed fluorescent material. In some embodiments, emission can be produced by any or all of the sensitizer, the acceptor, and the final emitter. In some embodiments, the acceptor has an emission at room temperature with a full width at half maximum (FWHM) equal to or less than 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5 nm. A narrower FWHM means that the OLED shows better color purity for the application.

[0313] As used herein, phosphorescence generally refers to the emission of a photon upon a change in the electron spin quantum number, i.e., the initial and final states of the emission have different electron spin quantum numbers, such as from a T1 to an S0 state. Most of the Ir and Pt complexes currently used in OLEDs are phosphorescent emitters. In some embodiments, if an excited state complex formation involves a triplet emitter, such an excited state complex can also emit phosphorescence. On the other hand, a fluorescent emitter generally refers to the emission of a photon upon no change in the electron spin quantum number, such as from an S1 to an S0 state, or from a D1 to a D0 state. The fluorescent emitter can be a delayed fluorescent or non-delayed fluorescent emitter. Depending on the spin state, the fluorescent emitter can be a singlet emitter or a triplet emitter or other multiplet emitter. It is believed that the internal quantum efficiency (IQE) of a fluorescent OLED can exceed the 25% spin-statistics limit with delayed fluorescence. There are two types of delayed fluorescence, i.e., P-type and E-type delayed fluorescence. P-type delayed fluorescence results from triplet-triplet annihilation (TTA). On the other hand, E-type delayed fluorescence does not rely on the collision of two triplets, but rather on the thermal population between a triplet and a singlet excited state. Thermal energy can activate the triplet to transition back to a singlet. This type of delayed fluorescence is also referred to as TADF. The E-type delayed fluorescence characteristics can be found in an excited state complex system or a single compound. Without being bound by theory, it is believed that a compound or an excited state complex with a small singlet-triplet energy gap (ΔEST) of less than or equal to 400, 350, 300, 250, 200, 150, 100, or 50 meV is required for TADF emission. There are two main types of TADF emitters, one is called donor-acceptor type TADF, and the other is called multi-resonance (MR) TADF. Typically, a single compound donor-acceptor TADF compound is constructed by linking an electron donor moiety (such as an amino or carbazole derivative) and an electron acceptor moiety (such as an N-containing six-membered aromatic ring or a cyano-substituted aromatic ring). A donor-acceptor excited state complex can be formed between a hole transporting compound and an electron transporting compound. Examples of MR-TADF materials include highly conjugated fused ring systems. In some embodiments, the MR-TADF materials comprise boron, carbon, and nitrogen atoms. Such materials can also comprise other atoms, such as oxygen. In some embodiments, the reverse intersystem crossing time from T1 to S1 for the delayed fluorescence emission is less than or equal to 10 microseconds at 293 K. In some embodiments, such time can be greater than 10 microseconds and less than 100 microseconds. S-T ) of less than or equal to 400, 350, 300, 250, 200, 150, 100, or 50 meV. There are two main types of TADF emitters, one is called donor-acceptor type TADF, and the other is called multi-resonance (MR) TADF. Typically, a single compound donor-acceptor TADF compound is constructed by linking an electron donor moiety (such as an amino or carbazole derivative) and an electron acceptor moiety (such as an N-containing six-membered aromatic ring or a cyano-substituted aromatic ring). A donor-acceptor excited state complex can be formed between a hole transporting compound and an electron transporting compound. Examples of MR-TADF materials include highly conjugated fused ring systems. In some embodiments, the MR-TADF materials comprise boron, carbon, and nitrogen atoms. Such materials can also comprise other atoms, such as oxygen. In some embodiments, the reverse intersystem crossing time from T1 to S1 for the delayed fluorescence emission is less than or equal to 10 microseconds at 293 K. In some embodiments, such time can be greater than 10 microseconds and less than 100 microseconds.

[0314] In some embodiments, the OLED can comprise an additional compound selected from the group consisting of a non-delayed fluorescent material, a delayed fluorescent material, a phosphorescent material, and combinations thereof.

[0315] In some embodiments, the inventive compounds described herein are phosphorescent materials.

[0316] In some embodiments, the phosphorescent material is an emitter that emits light within the OLED. In some embodiments, the phosphorescent material does not emit light within the OLED. In some embodiments, the phosphorescent material energy transfers its excited state to another material within the OLED. In some embodiments, the phosphorescent material participates in charge transport within the OLED. In some embodiments, the phosphorescent material is a sensitizer or component of a sensitizer, and the OLED further comprises an acceptor. In some embodiments, the phosphorescent material forms an exciplex with another material (e.g., host material, emitter material) within the OLED.

[0317] In some embodiments, the non-delayed fluorescent material or delayed fluorescent material is an emitter that emits light within the OLED. In some embodiments, the non-delayed fluorescent material or delayed fluorescent material does not emit light within the OLED. In some embodiments, the non-delayed fluorescent material or delayed fluorescent material energy transfers its excited state to another material within the OLED. In some embodiments, the non-delayed fluorescent material or delayed fluorescent material participates in charge transport within the OLED. In some embodiments, the non-delayed fluorescent material or delayed fluorescent material is an acceptor, and the OLED further comprises a sensitizer.

[0318] In some embodiments of the OLED, the delayed fluorescent material comprises at least one donor group and at least one acceptor group. In some embodiments, the delayed fluorescent material is a metal complex. In some embodiments, the delayed fluorescent material is a non-metal complex. In some embodiments, the delayed fluorescent material is a Pt, Pd, Zn, Cu, Ag, or Au complex (some of which are also known as metal assisted (MA) TADF). In some embodiments, the metal assisted delayed fluorescent material comprises a metal-carbene bond. In some embodiments, the non-delayed fluorescent material or delayed fluorescent material comprises at least one chemical group selected from the group consisting of aryl-amine, aryloxy, arylthio, triphenylene, carbazole, indolocarbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, 5λ 2 benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-borafluorene[3,2,1-de]anthracene, 5λ 2 ,9λ 2 -diaza-13b-borafluorene[2,3,4-de]anthracene, 5-oxa-9λ 2-aza-13b-boronazonaphtho[3,2,1-de]anthracene, azacyclohexylborane, oxaborane, dihydroacridine, oxanthracene, dihydrobenzoazasilane, dibenzooxasilane, phenoxazine, phenoxthiazine, dihydrophenoxazine, fluorene, naphthalene, anthracene, phenanthrene, phenanthroline, benzoquinoline, quinoline, isoquinoline, quinazoline, pyrimidine, pyrazine, pyridine, triazine, borane, amino, silane, their aza variants and combinations thereof. In some embodiments, the non-delayed fluorescent material or the delayed fluorescent material comprises tri(aryl / heteroaryl)borane, wherein one or more pairs of substituents from the aryl / heteroaryl group are bonded to form a ring. In some embodiments, the fluorescent material comprises at least one chemical group selected from the group consisting of: naphthalene, anthracene, phenanthrene, fluorene, pyrene, Perylene and azurite.

[0319] In another aspect, the OLED of this disclosure may further include an emitting region containing a compound or formulation of a compound as disclosed in the foregoing compound portion of this disclosure. In some embodiments, the emitting region may contain a compound or formulation of a compound as described herein. In some embodiments, the emitting region comprises one or more organic layers, at least one of said one or more organic layers having a minimum thickness selected from the group consisting of: 350, 400, 450, 500, 550, 600, 650 and In some embodiments, at least one of the one or more organic layers is formed by an emission system having a figure of merit (FOM) equal to or greater than a value selected from the group consisting of: 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2.90, 2.95, 3.00, 5.00, 10.0, 15.0, and 20.0. A definition of FOM is available in U.S. Patent Application Publication No. 2023 / 0292605, the entire contents of which are incorporated herein by reference. In some embodiments, at least one of the one or more organic layers comprises a compound or formulation of a compound as disclosed in Parts A and D of this disclosure.

[0320] In some embodiments, the OLEDs or emissive regions disclosed herein comprising a compound of the application can be incorporated into a full color pixel arrangement of a device. A full color pixel arrangement of such a device comprises at least one pixel, wherein the at least one pixel comprises a first sub-pixel and a second sub-pixel. The first sub-pixel comprises a first OLED comprising a first emissive region. The second sub-pixel comprises a second OLED comprising a second emissive region. In some embodiments, the first and / or second OLEDs, the first and / or second emissive regions can be the same or different and each can independently have various device features and various embodiments of a compound of the application included therein, as well as various combinations and subcombinations of various device features and various embodiments of a compound of the application included therein, as disclosed herein.

[0321] In some embodiments, the first emissive region is configured to emit light having a peak wavelength λ max1 ; the second emissive region is configured to emit light having a peak wavelength λ max2 . In some embodiments, the difference between peak wavelengths λ max1 and λ max2 is at least 4 nm but within the same color. For example, the light described above as light of a light blue color and a dark blue color. In some embodiments, the first emissive region is configured to emit light having a peak wavelength λ max1 in one region of the visible spectrum of 400-500 nm, 500-600 nm, 600-700 nm; and the second emissive region is configured to emit light having a peak wavelength λ max2 in one of the remaining regions of the visible spectrum of 400-500 nm, 500-600 nm, 600-700 nm. In some embodiments, the first emissive region comprises (if more than one) a first number of emissive layers deposited one on top of the other; and the second emissive region comprises (if more than one) a second number of emissive layers deposited one on top of the other; and the first number is different from the second number. In some embodiments, both the first emissive region and the second emissive region comprise a phosphorescent material, which can be the same or different. In some embodiments, the first emissive region comprises a phosphorescent material and the second emissive region comprises a fluorescent material. In some embodiments, both the first emissive region and the second emissive region comprise a fluorescent material, which can be the same or different.

[0322] In some embodiments, at least one pixel of the OLED or emissive region comprises a total of N sub-pixels; wherein the N sub-pixels comprise a first sub-pixel and a second sub-pixel; wherein each of the N sub-pixels comprises an emissive region; wherein the total number of emissive regions within the at least one pixel is equal to or less than N-1. In some embodiments, the second emissive region is identical to the first emissive region; and each sub-pixel of the at least one pixel comprises one emissive region identical to the first emissive region. In some embodiments, a full color pixel arrangement can have a plurality of pixels comprising a first pixel region and a second pixel region; wherein at least one display characteristic in the first pixel region is different from a corresponding display characteristic of the second pixel region, and wherein the at least one display characteristic is selected from the group consisting of: resolution, cavity mode, color, out-coupling, and color filter.

[0323] In some embodiments, the OLED is a stacked OLED comprising one or more charge generation layers (CGLs). In some embodiments, the OLED comprises a first electrode, a first emissive region disposed over the first electrode, a first CGL disposed over the first emissive region, a second emissive region disposed over the first CGL, and a second electrode disposed over the second emissive region. In some embodiments, the first emissive region and / or the second emissive region can have various device features as described above for the pixelated device. In some embodiments, the stacked OLED is configured to emit white. In some embodiments, one or more of the emissive regions in the pixelated OLED or stacked OLED comprise a sensitizer and an acceptor having various sensitizer device features and various embodiments of the inventive compounds disclosed herein. For example, the first emissive region is comprised in a sensitized device, while the second emissive region is not comprised in a sensitized device; in some cases, both the first emissive region and the second emissive region are comprised in a sensitized device.

[0324] In some embodiments, the OLED can emit at least 1%, 5%, 10%, 30%, 50%, 70%, 80%, 90%, 95%, 99%, or 100% of light from plasmonic modes. In some embodiments, at least one of the anode, the cathode, or a new layer disposed above the organic emissive layer acts as an enhancement layer. The enhancement layer includes a plasmonic material that exhibits surface plasmon resonance, which non-radiatively couples to the emitter material and transfers excitation state energy from the emitter material to non-radiative modes of surface plasmon polaritons. In some embodiments, the enhancement layer is disposed at a distance from the organic emissive layer that does not exceed a threshold distance, where the emitter material has a total non-radiative decay rate constant and a total radiative decay rate constant due to the presence of the enhancement layer. The threshold distance is where the total non-radiative decay rate constant equals the total radiative decay rate constant. Another threshold distance is where the total radiative decay rate constant divided by the sum of the total non-radiative decay rate constant and the total radiative decay rate constant equals the photoluminescence quantum yield of the emissive material in the absence of the enhancement layer.

[0325] In some embodiments, the OLED further includes an out-coupling layer. In some embodiments, the out-coupling layer is disposed above the enhancement layer on a side opposite the organic emissive layer. The out-coupling layer scatters energy from the surface plasmon polaritons. In some embodiments, this energy is scattered as photons into free space. In other embodiments, the energy is scattered from the surface plasmonic modes of the device into other modes, such as, but not limited to, organic waveguide modes, substrate modes, or another waveguide mode. In some embodiments, one or more intervening layers can be disposed between the enhancement layer and the out-coupling layer. Examples of intervening layers can be dielectric materials, including organic, inorganic, perovskite, oxide, and can include stacks and / or mixtures of these materials.

[0326] The enhancement layer changes the effective properties of the medium in which the emitter material resides, resulting in any or all of the following: reduced emissivity, altered emission line shape, emission intensity variation with angle, altered emitter material stability, altered OLED efficiency, and reduced OLED device roll-off efficiency. Placing an enhancement layer on the cathode side, the anode side, or both, or placing the enhancement layer itself as a CGL results in an OLED device that utilizes any of the above effects. In addition to the specific functional layers mentioned herein and illustrated in the various OLED examples shown in the figures, the OLEDs according to the present disclosure can also include any other functional layers commonly found in OLEDs.

[0327] In some embodiments, the enhancement layer can comprise a plasmonic material, an optically active supermaterial, or a hyperbolic supermaterial. In some embodiments, the plasmonic material comprises at least one metal. In such embodiments, the metal can comprise at least one of Ag, Al, Au, Ir, Pt, Ni, Cu, W, Ta, Fe, Cr, Mg, Ga, Rh, Ti, Ru, Pd, In, Bi, or Ca, alloys or mixtures of these materials, and stacks of these materials. In some embodiments, the enhancement layer is disposed as a planar layer. In other embodiments, the enhancement layer has periodically, quasi-periodically, or randomly arranged wavelength-sized features, or has periodically, quasi-periodically, or randomly arranged sub-wavelength-sized features.

[0328] In some embodiments, the outcoupling layer has periodically, quasi-periodically, or randomly arranged wavelength-sized features or sub-wavelength-sized features. In some embodiments, the outcoupling layer can be composed of a plurality of nanoparticles. In some embodiments, the outcoupling layer is composed of a plurality of nanoparticles disposed above a material. In these embodiments, the outcoupling layer can be adjusted by at least one of changing the size of the plurality of nanoparticles, changing the shape of the plurality of nanoparticles, changing the material of the plurality of nanoparticles, adjusting the thickness of the material, changing the refractive index of the material, adding an additional layer disposed above the plurality of nanoparticles, changing the thickness of the enhancement layer, or changing the material of the enhancement layer. The plurality of nanoparticles of the device can be formed of at least one of a metal, a dielectric material, a semiconductor material, an alloy of metals, a mixture of dielectric materials, a stack or layering of one or more materials, and / or a core of one type of material coated with a shell of another type of material. In some embodiments, the outcoupling layer is composed of at least metal nanoparticles, where the metal is selected from the group consisting of Ag, Al, Au, Ir, Pt, Ni, Cu, W, Ta, Fe, Cr, Mg, Ga, Rh, Ti, Ru, Pd, In, Bi, and Ca, alloys or mixtures of these materials, and stacks of these materials. In some embodiments, the outcoupling layer is formed by photolithography.

[0329] In some embodiments of the plasmonic device, the emitter and / or host compound used in the emission layer has a vertical dipole ratio (VDR) of 0.33 or greater. In some such embodiments, the emitter and / or host compound has a VDR of 0.40, 0.50, 0.60, 0.70, or greater.

[0330] In yet another aspect, the present disclosure also provides a consumer product comprising an organic light emitting device (OLED) having an anode; a cathode; and an organic layer disposed between the anode and the cathode, wherein the organic layer can comprise a compound or formulation of compounds as disclosed in the above compound section of the present disclosure.

[0331] In some embodiments, a consumer product comprises an OLED having an anode; a cathode; and an organic layer disposed between the anode and the cathode, wherein the organic layer can comprise a compound as described herein.

[0332] Generally, an OLED comprises at least one organic layer disposed between and electrically connected to an anode and a cathode. When a potential is applied across the layers, holes and electrons are injected into the organic layer from the electrodes. 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. When the exciton relaxes, it releases energy that can take the form of light. In some cases, the exciton can localize at an excimer or an exciplex. Non-radiative mechanisms, such as thermal relaxation, can also occur, but are generally considered undesirable.

[0333] Figure 1 An organic light emitting device 100 is shown. The figures are not necessarily drawn to scale. The device 100 can include a substrate 110, an anode 115, a hole injection layer (HIL) 120, a hole transport layer (HTL) 125, an electron blocking layer (EBL) 130, an emission layer (EML) 135, a hole blocking layer (HBL) 140, an electron transport layer (ETL) 145, an electron injection layer (EIL) 150, a protective layer 155, a cathode 160, and a blocking layer 170. The cathode 160 is a composite cathode having a first conductive layer 162 and a second conductive layer 164. The device 100 can be fabricated by sequentially depositing the layers. The properties and functions of these various layers, as well as example materials, are described in more detail in US 7,279,704, columns 6-10, which is incorporated by reference.

[0334] More examples of each of these layers can be found. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Patent No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F4-TCNQ in a 50:1 molar ratio, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety. Examples of light emitting 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 in a 1:1 molar ratio, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety. U.S. Patent Nos. 5,703,436 and 5,707,745, incorporated by reference in their entirety, disclose examples of cathodes including composite cathodes with a thin layer of metal (such as Mg:Ag) overlying a transparent, conductive, sputter-deposited ITO layer. The theory 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. Descriptions of protective layers can be found in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated by reference in its entirety.

[0335] Figure 2 An inverted OLED 200 is shown. The device includes a substrate 210, a cathode 215, an emissive layer 220, a hole transport layer 225, and an anode 230. Device 200 can be fabricated by depositing the layers sequentially. Because the most commonly used OLED configuration has a cathode disposed over an anode, and device 200 has a cathode 215 disposed under anode 230, device 200 can be referred to as an "inverted" OLED. Similar materials as those described with respect to device 100 can be used in the corresponding layers of device 200. Figure 2 One example of how some layers can be omitted from the structure of device 100 is provided.

[0336] Figure 1 and 2The simple layered structure illustrated in the middle is provided by way of non-limiting example, and it is understood that embodiments of the present disclosure can be used in conjunction with a variety of other structures. The particular materials and structures described are exemplary in nature and other materials and structures can be used. Functional OLEDs can be obtained by combining the various layers described in different ways, or the layers can be omitted entirely. Other layers not specifically described can also be included. Materials other than those specifically described can be employed. As an example, the OLED described below can be replaced by a PLED, having a structure as described in U.S. Patent No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of further example, an OLED with a single organic layer can be employed. The OLED can be stacked, as described in U.S. Patent No. 5,707,745 to Forrest et al., which is incorporated by reference in its entirety. OLED structures can deviate from the simple layered structure illustrated in FIGS. 1A-1C. For example, the substrate can include an angled reflective surface to improve out-coupling, such as the mesa structure described in U.S. Patent No. 6,091,195 to Forrest et al., and / or the dimple structure described in U.S. Patent No. 5,834,893 to Bulovic et al., which are incorporated by reference in their entireties. Figure 1 and 2 The simple layered structure illustrated in the middle is provided by way of non-limiting example, and it is understood that embodiments of the present disclosure can be used in conjunction with a variety of other structures. The particular materials and structures described are exemplary in nature and other materials and structures can be used. Functional OLEDs can be obtained by combining the various layers described in different ways, or the layers can be omitted entirely. Other layers not specifically described can also be included. Materials other than those specifically described can be employed. As an example, the OLED described below can be replaced by a PLED, having a structure as described in U.S. Patent No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of further example, an OLED with a single organic layer can be employed. The OLED can be stacked, as described in U.S. Patent No. 5,707,745 to Forrest et al., which is incorporated by reference in its entirety. OLED structures can deviate from the simple layered structure illustrated in FIGS. 1A-1C. For example, the substrate can include an angled reflective surface to improve out-coupling, such as the mesa structure described in U.S. Patent No. 6,091,195 to Forrest et al., and / or the dimple structure described in U.S. Patent No. 5,834,893 to Bulovic et al., which are incorporated by reference in their entireties.

[0337] The simple layered structure illustrated in the middle is provided by way of non-limiting example, and it is understood that embodiments of the present disclosure can be used in conjunction with a variety of other structures. The particular materials and structures described are exemplary in nature and other materials and structures can be used. Functional OLEDs can be obtained by combining the various layers described in different ways, or the layers can be omitted entirely. Other layers not specifically described can also be included. Materials other than those specifically described can be employed. As an example, the OLED described below can be replaced by a PLED, having a structure as described in U.S. Patent No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of further example, an OLED with a single organic layer can be employed. The OLED can be stacked, as described in U.S. Patent No. 5,707,745 to Forrest et al., which is incorporated by reference in its entirety. OLED structures can deviate from the simple layered structure illustrated in FIGS. 1A-1C. For example, the substrate can include an angled reflective surface to improve out-coupling, such as the mesa structure described in U.S. Patent No. 6,091,195 to Forrest et al., and / or the dimple structure described in U.S. Patent No. 5,834,893 to Bulovic et al., which are incorporated by reference in their entireties. Figure 1 2 The simple layered structure illustrated in the middle is provided by way of non-limiting example, and it is understood that embodiments of the present disclosure can be used in conjunction with a variety of other structures. The particular materials and structures described are exemplary in nature and other materials and structures can be used. Functional OLEDs can be obtained by combining the various layers described in different ways, or the layers can be omitted entirely. Other layers not specifically described can also be included. Materials other than those specifically described can be employed. As an example, the OLED described below can be replaced by a PLED, having a structure as described in U.S. Patent No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of further example, an OLED with a single organic layer can be employed. The OLED can be stacked, as described in U.S. Patent No. 5,707,745 to Forrest et al., which is incorporated by reference in its entirety. OLED structures can deviate from the simple layered structure illustrated in FIGS. 1A-1C. For example, the substrate can include an angled reflective surface to improve out-coupling, such as the mesa structure described in U.S. Patent No. 6,091,195 to Forrest et al., and / or the dimple structure described in U.S. Patent No. 5,834,893 to Bulovic et al., which are incorporated by reference in their entireties.

[0338] ​Unless otherwise described, any of the layers of the various embodiments can be deposited by any suitable method. For organic layers, preferred methods include thermal evaporation, ink-jet (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) as described in U.S. Pat. No. 6,337,102 to Fifer et al., which is incorporated by reference in its entirety, and deposition by organic vapor jet printing (OVJP, also referred to as organic vapor jet deposition (OVJD)) 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 conducted in a nitrogen or inert atmosphere. For other layers, preferred methods include thermal evaporation, sputtering, chemical vapor deposition, atomic layer deposition, and e-beam deposition. Preferred patterning methods include deposition through a mask, photolithography, and cold welding (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, for example, ink-jet and organic vapor jet printing (OVJP) deposition methods. Other methods can also be used. The materials to be deposited can be modified in order to adapt them to the particular deposition method. For example, substituents can be used in small molecules to enhance their solution processability. Substituents such as alkyl and aryl groups, branched or unbranched, and preferably containing at least 3 carbons, can be used in small molecules to enhance their solution processability. Substituents with 20 or more carbons can be used, and from 3 to 20 carbons are a preferred range. Materials with asymmetric structures can have better solution processability than those with symmetric structures, because they can have lower re-crystallization tendency. Dendrimer substituents can be used to enhance solution processability of small molecules.

[0339] Devices fabricated in accordance with embodiments of the disclosure can further optionally include a barrier layer. One use of a barrier layer is to protect the electrodes and organic layer from the deleterious effects of exposure to an environment including oxygen, moisture, and / or gases, etc. The barrier layer can be deposited over, under, or next to the substrate, electrodes, or any other part of the device, including the edges. A barrier layer can be deposited by a variety of known techniques including for example sputtering, e-beam evaporation, thermal evaporation, chemical vapor deposition, physical vapor deposition, plasma-enhanced chemical vapor deposition, or laser ablation, among others. A barrier layer can have a single layer or multiple layers. The barrier layer can be formed of a variety of materials including inorganic materials and organic materials. Any suitable material or combination of materials can be used for the barrier layer. The barrier layer can incorporate inorganic compounds or organic compounds or both. Preferred barrier layers include multiple alternating layers of polymeric and non-polymeric materials; organic and inorganic materials; or mixtures of polymeric and non-polymeric materials, one example of which is described in U.S. Patent No. 7,968,146, PCT Patent Application Nos. PCT / US2007 / 023098 and PCT / US2009 / 042829, which are incorporated by reference in their entirety.

[0340] Devices made in accordance with embodiments of the disclosure can be incorporated into a wide variety of electronic assembly modules (or units) that can be incorporated into a wide variety of electronic products or intermediate assemblies. Examples of the electronic products or intermediate assemblies include display screens, lighting devices (such as discrete light source devices or lighting panels), etc. that can be utilized by end- user product manufacturers. The electronic assembly modules can optionally include driving electronics and / or power supplies. Devices made in accordance with embodiments of the disclosure can be incorporated into a wide variety of consumer products that have one or more electronic assembly modules (or units) incorporated therein. A consumer product is disclosed that includes an OLED that includes a compound of the disclosure in an organic layer in the OLED. The consumer product should include any kind of product that includes one or more of one or more light sources and / or some type of visual display. Some examples of the consumer product 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 transparent or partially transparent displays, flexible displays, rollable displays, foldable displays, stretchable displays, laser printers, telephones, cellular phones, tablet computers, phablets, personal digital assistants (PDAs), wearable devices, laptop computers, digital cameras, video cameras, viewfinders, micro-displays (displays less than 2 inches in diagonal), 3-D displays, virtual reality or augmented reality displays, vehicles, video walls containing multiple displays tiled together, theater or stadium screens, light therapy devices, and signs. Devices made in accordance with the disclosure can be controlled using a variety of control mechanisms, including passive matrix and active matrix. It is intended that many of the devices be used in temperature ranges comfortable for humans, such as 18 °C to 30 °C, and more preferably at room temperature (20-25 °C), but can be used outside this temperature range (e.g., -40 °C to +80 °C).

[0341] Further details regarding OLEDs and the definitions described above can be found in U.S. Patent No. 7,279,704, which is incorporated herein by reference in its entirety.

[0342] The materials and structures described herein can be applied to devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors can employ the materials and structures. More generally, organic devices such as organic transistors can employ the materials and structures.

[0343] In some embodiments, the OLED has one or more features selected from the group consisting of: flexible, rollable, foldable, stretchable, and bendable. 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 one or more quantum dots. Such quantum dots can be in the emissive layer, or in other functional layers, such as a down-conversion layer.

[0344] In some embodiments, the OLED comprises an RGB pixel arrangement or a white plus color filter pixel arrangement. In some embodiments, the OLED is a mobile device, a handheld device, or a wearable device. In some embodiments, the OLED is a display panel with a diagonal less than 10 inches or an area less than 50 square inches. In some embodiments, the OLED is a display panel with a diagonal of at least 10 inches or an area of at least 50 square inches. In some embodiments, the OLED is an illumination panel.

[0345] Other materials used in OLEDs

[0346] The materials described herein are useful as various examples of specific layers that can be used in OLEDs. They can also be used in combination with a wide variety of other materials present in devices. For example, the emissive dopants disclosed herein can be used by themselves as the emissive dopant in the EML, or in combination with a wide variety of other emitters, hosts, transport layers, blocking layers, injection layers, electrodes, and other layers that can be present. The materials described or referred to below are non-limiting examples of materials that can be used in combination with the compounds and devices disclosed herein, and one of skill in the art can readily consult the literature to identify other materials that can be used in combination.

[0347] a) Conductive dopants:

[0348] Charge transport layers can be doped with conductive dopants to substantially change their charge carrier density, which in turn will change their conductivity. The conductivity is increased by the creation of charge carriers in the matrix material, and depending on the type of dopant, a shift of the Fermi level of a semiconductor can also be achieved. Hole transport layers can be doped with p-type conductive dopants, and n-type conductive dopants are used in electron transport layers. In some embodiments, the conductive dopants comprise at least one chemical moiety selected from the group consisting of: cyano groups, fluorinated aryl or heteroaryl groups, fluorinated alkyl or cycloalkyl groups, alkylene groups, heteroaryl groups, amides, benzo dithiophenes, and highly conjugated heteroaryl groups extended by acyclic double bonds.

[0349] b) HIL / HTL:

[0350] The hole injection / transport materials used in this disclosure are not particularly limited, and any compound may be used, provided that the compound is commonly used as a hole injection / transport material. Examples of materials include (but are not limited to): phthalocyanine or porphyrin derivatives; aromatic amine derivatives; indole-carbazole derivatives; polymers containing fluorinated hydrocarbons; polymers with conductive dopants; conductive polymers, such as PEDOT / PSS; self-assembled monomers derived from compounds such as phosphonic acids and silane derivatives; and metal oxide derivatives, such as MoO. x p-type semiconductive organic compounds, such as 1,4,5,8,9,12-hexaazatriphenylhexacarbonitrile; metal complexes; and crosslinkable compounds.

[0351] Examples of aromatic amine derivatives used for HIL or HTL include (but are not limited to) the following general structures:

[0352]

[0353] Ar 1 To Ar 9 Each of these is selected from the group consisting of, for example, aromatic hydrocarbon cyclic compounds such as: benzene, biphenyl, terphenyl, triphenylene, naphthalene, anthracene, fenene, fluorene, pyrene, Perylene and azurite; the group consisting of, for example, aromatic heterocyclic compounds such as: dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridinylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxtriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxthiazine, oxadiazine, indole, benzimidazole, indazole, inoxazine, benzoxazole, benziisoxazole, benzothiazole, quinoline, isoquinoline, zoline, quinazoline Quinoxaline, naphthidine, phthalazine, pteridine, oxanthracene, acridine, phenazine, phenothiazine, phenoxazine, benzofuranopyridine, furanodipyridine, benzothiophenopyridine, thiophenodipyridine, benzoselenophenepyridine, and selenophenodipyridine; and the group consisting of 2 to 10 cyclic structural units, said cyclic structural units being groups of the same or different types selected from aromatic hydrocarbon cyclic groups and aromatic heterocyclic groups and bonded to each other directly or via at least one of oxygen, nitrogen, sulfur, silicon, phosphorus, boron, chain structural units, and aliphatic cyclic groups. 1 To Ar 9 Each of them may be unsubstituted or may be substituted by the general substituents described above, and any two substituents may be joined or fused together to form a ring.

[0354] In some embodiments, each Ar 1 To Ar 9 Independently includes portions selected from the following groups:

[0355]

[0356] wherein k is an integer from 1 to 20; X 101 to X 108 is C or N; Z 101 is C, N, O, or S.

[0357] Examples of metal complexes used in the HIL or HTL include, but are not limited to, the following general formula:

[0358]

[0359] wherein Met is a metal having an atomic weight greater than 40; (Y 101 -Y 102 ) is a bidentate ligand, Y 101 and Y 102 are independently selected from C, N, O, P, and S; L 101 is 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.

[0360] In some embodiments, (Y 101 -Y 102 ) is a 2-phenylpyridine or 2-phenylimidazole derivative. In some embodiments, (Y 101 -Y 102 ) is a carbene ligand. In some embodiments, Met is selected from Ir, Pt, Pd, Os, Cu, and Zn. In some embodiments, the metal complex has a minimum oxidation potential in solution that is less than about 0.6 V smaller than the Fc + / Fc couple.

[0361] In some embodiments, the HIL / HTL material is selected from the group consisting of phthalocyanine and porphyrin compounds, starburst triarylamines, CF x fluorocarbon polymers, conductive polymers (e.g., PEDOT:PSS, polyaniline, polythiophene), phosphonic acid and silane SAMs, triarylamine or polythiophene polymers containing conductive dopants, organic compounds containing conductive inorganic compounds such as molybdenum oxide and tungsten oxide, n-type semiconductive organic complexes, metal organic metal complexes, cross-linkable compounds, polymeric and copolymeric compounds based on polythiophene, triarylamines, triarylamine containing spirofluorene core, arylamine carbazole compounds, triarylamine containing (di)benzothiophene / (di)benzofuran, indolocarbazole, isoindole compounds, and metal carbene complexes.

[0362] c) EBL:

[0363] An electron blocking layer (EBL) can be used to reduce the number of electrons and / or excitons leaving the emission layer. The presence of such a blocking layer in a device can result in generally higher efficiencies and / or longer lifetimes as compared to similar devices lacking a blocking layer. Further, a blocking layer can be used to confine emission to a desired area of an OLED. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or a higher triplet energy than one or more emitters proximate to the EBL interface. In some embodiments, the compound used in the EBL contains at least one carbazole group and / or at least one aryl amine group. In some embodiments, the compound used in the EBL has a shallower HOMO energy level than the HOMO energy level of one or more of the hosts in the EML. In some embodiments, the compound used in the EBL contains the same molecule or the same functional group as used in one of the hosts described below.

[0364] d) Host:

[0365] The light-emitting layer of the organic EL device of the present disclosure preferably contains at least a light-emitting material as a dopant, and a host material. Examples of the host material are not particularly limited, and any metal complex or organic compound can be used as long as the host does not completely quench the emission of the dopant.

[0366] Examples of the metal complex used as the host preferably have the following general formula:

[0367]

[0368] where Met is a metal; (Y 103 -Y 104 ) is a bidentate ligand, Y 103 and Y 104 are coordination atoms of Y 101 and Y 103 are independently selected from C, N, O, P, and S; L 104 is 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.

[0369] In some embodiments, the metal complex is:

[0370]

[0371] where (O-N) is a bidentate ligand having a metal coordinated to O and N atoms.

[0372] In some embodiments, Met is selected from Ir and Pt. In another embodiment, (Y 103 -Y 104 ) is a carbene ligand.

[0373] In some embodiments, the host compound contains at least one selected from the group consisting of, for example, aromatic hydrocarbon cyclic compounds such as: benzene, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, fenene, fluorene, pyrene, etc. Perylene and azurite; the group consisting of, for example, aromatic heterocyclic compounds such as: dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridinylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxtriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxthiazine, oxadiazine, indole, benzimidazole, indazole, inoxazine, benzoxazole, benzoisoxazole, benzothiazine, quinoline, isoquinoline, cinnamoline, quinazoline, quinoxaline, naphthidine, phthalazine, pteridine, oxanthracene, acridine, phenazine, phenothiazine, phenothiazine, aziridine, aza -Dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenene, aza-carbazole, aza-indolocarbazole, aza-triphenylene, aza-tetraphenylene, 5λ2-benzo[d]benzo[4,5]imidazo[3,2-a]imidazo, 5,9-dioxa-13b-borona[3,2,1-de]anthracene; and groups consisting of 2 to 10 cyclic structural units, said cyclic structural units being groups of the same or different types selected from aromatic hydrocarbon cyclic groups and aromatic heterocyclic groups and bonded to each other directly or via at least one of oxygen, nitrogen, sulfur, silicon, phosphorus, boron, chain structural units, and aliphatic cyclic groups. Each option within each group may be unsubstituted or may be substituted by universal substituents as described herein or may be further fused.

[0374] In some embodiments, the host compound comprises at least one portion selected from the group consisting of:

[0375]

[0376]

[0377] Where k is an integer between 0 and 20 or between 1 and 20. X 101 To X 108 Independently selected from C or N. Z 101 and Z 102 It is independently selected from C, N, O, or S.

[0378] In some embodiments, the host material is selected from the group consisting of: arylcarbazole, metal 8-hydroxyquinoline compounds (e.g., alq3, balq), metal phenoxybenzothiazole compounds, conjugated oligomers and polymers (e.g., polyfluorene), aromatic fused rings, zinc complexes, and based on... compounds, aryltriphenylenyl compounds, polyfused heteroaryl compounds, donor-acceptor type molecules, dibenzofuran / dibenzothiophene compounds, polymers (e.g., PVK), spirofluorene compounds, spirofluorene-carbazole compounds, indolocarbazole, 5-membered ring electron-deficient heterocycles (e.g., triazole, oxadiazole), tetraphenyl complexes, metal phenoxypyridine compounds, metal coordination complexes (e.g., Zn, Al with N^N ligands), dibenzothiophene / dibenzofuran-carbazole compounds, silicon / germanium aryl compounds, arylbenzoyl esters, non-conjugated group linked carbazoles, aza-carbazole / dibenzofuran / dibenzothiophene compounds, and high triplet state metal organometallic complexes (e.g., metal-carbene complexes).

[0379] e) Emitter materials in the EML:

[0380] One or more emitter materials can be used in conjunction with the compounds or devices of the present disclosure. The emitter materials can be emissive or non-emissive in the present devices as described herein. Examples of emitter materials are not particularly limited, and any compound can be used so long as the compound is capable of producing emission in a conventional OLED device. Examples of suitable emitter materials include, but are not limited to, compounds capable of producing emission via phosphorescence, non-delayed fluorescence, delayed fluorescence (especially thermally activated delayed fluorescence, i.e., TADF (also known as E-type delayed fluorescence)), triplet-triplet annihilation, or a combination of these methods.

[0381] In some embodiments, the emitter material has the formula M(L 1 ) x (L 2 ) y (L 3 ) z ;

[0382] wherein L 1 , L 2 , and L 3 may be the same or different;

[0383] wherein x is 1, 2, or 3;

[0384] wherein y is 0, 1, or 2;

[0385] wherein z is 0, 1, or 2;

[0386] wherein x + y + z is the oxidation state of the metal M;

[0387] wherein L 1 is selected from the group consisting of the structures of the following list of ligands:

[0388]

[0389]

[0390]

[0391] wherein each L 2 and L 3 is independently selected from the group consisting of structures in the list of ligands wherein:

[0392] M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Pd, Zn, Au, Ag, and Cu;

[0393] T is selected from the group consisting of B, Al, Ga, and In;

[0394] K 1' is a direct bond or selected from the group consisting of NR e , PR e , O, S, and Se;

[0395] each Y 1 to Y 15 is independently selected from the group consisting of carbon and nitrogen;

[0396] Y' is selected from the group consisting of BR e , NR e , PR e , O, S, Se, C=0, S=0, S02, CR e R f , SiR e R f , and GeR e R f ;

[0397] each R a , R b , R c , and R d may independently represent mono-substitution to the maximum possible number of substitutions, or no substitution;

[0398] each R a1 , R b1 , R c1 , R d1 , R a , R b , R c , R d , R e , and R f is independently hydrogen or a substituent selected from the group consisting of the generic substituents defined herein; and

[0399] Any two substituents can be fused or joined to form a ring or to form a polydentate ligand.

[0400] In some embodiments, the emitter material is selected from the group consisting of the following dopant Group 1:

[0401]

[0402]

[0403]

[0404]

[0405]

[0406]

[0407] wherein

[0408] X 96 to X 99 each independently is C or N;

[0409] each Y 100 is independently selected from the group consisting of NR", O, S, and Se;

[0410] each of R 10a , R 20a , R 30a , R 40a , and R 50a independently represents mono-substitution, up to maximum substitution, or no substitution;

[0411] each of R, R', R", R 10a , R 11a , R 12a , R 13a , R 20a , R 30a , R 40a , R 50a , R 60 , R 70 , R 97 , R 98 , and R 99 independently is hydrogen or a substituent selected from the group consisting of the generic substituents as defined herein; any two substituents can be joined or fused to form a ring.

[0412] In some embodiments, the emitter material is selected from the group consisting of the following dopant Group 2:

[0413]

[0414]

[0415]

[0416]

[0417]

[0418]

[0419]

[0420]

[0421] wherein:

[0422] each Y 100 is independently selected from the group consisting of NR", O, S, and Se;

[0423] L is independently selected from the group consisting of a direct bond, BR", BR"R"', NR", PR", O, S, Se, C=O, C=S, C=Se, C=NR", C=CR"R"', S=O, SO2, CR", CR"R"', SiR"R"', GeR"R"', alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof;

[0424] X 100 and X 200 is selected from the group consisting of O, S, Se, NR", and CR"R"' at each occurrence;

[0425] each R A" , R B" , R C" , R D" , R E" , and R F" independently represents mono-substitution, up to maximum substitution, or no substitution;

[0426] R, R', R", R"', R A1' , R A2' , R A" , R B" , R C" , R D" , R E" , R F" , R G" , R H" , R I" , R J" , R K" , R L" , R M" , and RN" each of R, R, and R is independently hydrogen or a substituent selected from the group consisting of general substituents as defined herein; any two substituents can be joined or fused to form a ring.

[0427] In some embodiments of the above dopant groups 1 and 2, each unsubstituted aromatic carbon atom can be replaced with N to form a nitrogen heterocycle. In some embodiments, the maximum number of N atoms in one ring is 1 or 2. In some embodiments of the above dopant group 2, the Pt atom in each formula can be replaced with a Pd atom.

[0428] In some embodiments of the OLED, the delayed fluorescence material comprises at least one donor group and at least one acceptor group. In some embodiments, the delayed fluorescence material is a metal complex. In some embodiments, the delayed fluorescence material is a non-metal complex. In some embodiments, the delayed fluorescence material is a Zn, Cu, Ag, or Au complex.

[0429] In some embodiments of the OLED, the delayed fluorescence material has the formula M(L 5 )(L 6 ), wherein M is Cu, Ag, or Au, L 5 and L 6 are different, and L 5 and L 6 are independently selected from the group consisting of:

[0430]

[0431]

[0432] wherein A 1 -A 9 are each independently selected from C or N;

[0433] each R P , R Q , and R U independently represents mono-substitution, up to maximum substitution, or no substitution;

[0434] wherein each R P , R P , R U , R SA , R SB , R RA , R RB , R RC , R RD , R RE , and R RF is independently hydrogen or a substituent selected from the group consisting of general substituents as defined herein; any two substituents can be joined or fused to form a ring.

[0435] In some embodiments of the OLED, the delayed fluorescence material comprises at least one of the donor moieties selected from the group consisting of:

[0436]

[0437] wherein Y T , Y U , Y V and Y W are each independently selected from the group consisting of B, C, Si, Ge, N, P, O, S, Se, C=0, S=0, and S02.

[0438] In some of the above embodiments, any carbon ring atom in each phenyl ring of any of the above structures up to a total of at most three carbon ring atoms together with its substituents can be replaced by N.

[0439] In some embodiments, the delayed fluorescence material comprises at least one of the acceptor moieties selected from the group consisting of nitrile, isonitrile, borane, fluoride, pyridine, pyrimidine, pyrazine, triazine, azido-carbazole, azido-dibenzothiophene, azido-dibenzofuran, azido-dibenzoselenophene, azido-triphenylene, imidazole, pyrazole, oxazole, thiazole, isoxazole, isothiazole, triazole, thiadiazole, and oxadiazole. In some embodiments, the acceptor moieties and donor moieties as described herein can be connected directly, via a conjugated linker or a non-conjugated linker (such as sp 3 carbon or silicon atom).

[0440] In some embodiments, the fluorescent material comprises at least one of the chemical moieties selected from the group consisting of:

[0441]

[0442]

[0443] wherein Y F , Y G , Y H and Y I are each independently selected from the group consisting of B, C, Si, Ge, N, P, O, S, Se, C=0, S=0, and S02;

[0444] wherein X F and X G are each independently selected from the group consisting of C and N.

[0445] In some of the above embodiments, any carbon ring atom in each phenyl ring of any of the above structures up to a total of at most three carbon ring atoms together with its substituents can be replaced by N.

[0446] f) HBL:

[0447] A hole blocking layer (HBL) can be used to reduce the number of holes and / or excitons leaving the emission layer. The presence of such a blocking layer in a device can result in substantially higher efficiency and / or longer lifetime compared to a similar device lacking a blocking layer. Furthermore, a blocking layer can 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 a higher triplet energy than one or more of the emitters nearest the HBL interface.

[0448] In some embodiments, the compounds used in the HBL contain the same molecule or the same functional group as used in the hosts described above.

[0449] In some embodiments, the compounds used in the HBL comprise at least one of the following moieties selected from the group consisting of:

[0450]

[0451] wherein k is an integer from 1 to 20; L 101 is another ligand, and k' is an integer from 1 to 3.

[0452] g) ETL:

[0453] An electron transport layer (ETL) can include a material capable of transporting electrons. The electron transport layer can be intrinsic (undoped) or doped. Doping can be used to enhance the conductivity. Examples of ETL materials are not particularly limited and can use any metal complex or organic compound as long as it is typically used to transport electrons.

[0454] In some embodiments, the compounds used in the ETL comprise at least one of the following moieties in the molecule: and fullerene; wherein k is an integer from 1 to 20, X 101 to X 108 is selected from C or N; Z 101 is selected from the group consisting of C, N, O, and S.

[0455] In some embodiments, the metal complexes used in the ETL contain, but are not limited to, the following general formula:

[0456]

[0457] wherein (O-N) or (N-N) is a bidentate ligand having a metal coordinated to atoms O, N, or N,N; L 101is another ligand; k' is an integer value from 1 to the maximum number of ligands that can be attached to the metal.

[0458] In some embodiments, the ETL material is selected from the group consisting of anthracene-benzimidazole compounds, aza-triphenylene derivatives, anthracene-benzothiazole compounds, metal 8-hydroxyquinolinate compounds, metal hydroxybenzoquinolinate compounds, bathocuprine compounds, 5-membered electron deficient heterocycles (e.g., triazole, oxadiazole, imidazole, benzimidazole), silole compounds, arylborane compounds, fluorinated aromatic compounds, fullerenes (e.g., C60), triazine complexes, and Zn(N^N) complexes.

[0459] h) Charge Generation Layer (CGL)

[0460] In tandem or stacked OLEDs, the CGL plays an essential role in performance, which consists of an n-doped layer and a p-doped layer for injecting electrons and holes, respectively. The electrons and holes are supplied by the CGL and electrodes. The consumed electrons and holes in the CGL are refilled by electrons and holes injected from the cathode and anode, respectively; then, the ambipolar current gradually reaches a steady state. Typical CGL materials include n- and p-conductivity dopants used in transport layers.

[0461] In any of the compounds disclosed herein, hydrogen atoms can be partially or fully deuterated. The minimum amount of hydrogen in the compound that is deuterated is selected from the group consisting of 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, and 100%. As used herein, the percentage deuterated has its ordinary meaning and includes the percentage of all possible hydrogen and deuterium atoms replaced by deuterium atoms. In some embodiments, the deuterium atoms are attached to aromatic rings. In some embodiments, the deuterium atoms are attached to saturated carbon atoms, such as alkyl or cycloalkyl carbon atoms. In some other embodiments, the deuterium atoms are attached to heteroatoms, such as Si or Ge atoms.

[0462] 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, other materials and structures can be substituted for the many materials and structures described herein without deviating from the spirit of the invention. The invention as claimed is thus intended to include, among other things, the various embodiments described herein, as well as equivalents thereto. It should be understood that various theories as to why the invention works are not intended to be limiting.

[0463] Experimental data

[0464] Synthesis of compound-1 of the invention:

[0465] Synthesis of 4-bromo-l-(5-(tert-butyl)-[l,l'-biphenyl]-2-yl)-2-phenyl-lH- benzo[d]imidazole: To a stirred solution of 3-bromo-Nl-(5-(tert-butyl)-[l,l'- biphenyl]-2-yl)benzene-l,2-diamine (3.20 g, 1.0 eq, 8.013 mmol) and benzaldehyde (1.06 g, 1.02 mL, 1.25 eq, 10.02 mmol) in DMF (30 mL) was added sodium metabisulfite (3.05 g, 2 eq, 16.03 mmol). The resulting mixture was stirred at 120 °C for 18 h, cooled and diluted in ethyl acetate (100 mL) and washed with water (2 x 100 mL) and brine solution (50 mL). The organic layer was dried over sodium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by silica gel chromatography to afford 4-bromo-l-(5-(tert-butyl)-[l,l'-biphenyl]-2-yl)-2-phenyl-lH- benzo[d]imidazole (3.20 g, 6.5 mmol, 81%, 98% purity) as a white solid.

[0466] Synthesis of l,l'-bis(5-(tert-butyl)-[l,l'-biphenyl]-2-yl)-2,2'-diphenyl-lH,l'H-4,4'- biphenylazimide: A solution of 4-bromo-l-(5-(tert-butyl)-[l,l'-biphenyl]-2-yl)-2- phenyl-lH-benzo[d]imidazole (500 mg, 1 eq, 1.018 mmol), copper (78 mg, 1.2 eq, 1.221 mmol), palladium(II) acetate (23 mg, 0.1 eq, 101.8 μιηοΐ), and potassium carbonate (141 mg, 1 eq, 1.018 mmol) in anhydrous DMF (12 mL) was degassed with N2for 10 min and then heated to 165 °C for 16 h. The reaction mixture was filtered and washed with EtOAc, and the filtrate was washed with ice-cold water. The organic phase was concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to afford l,l'-bis(5-(tert-butyl)-[l,l'-biphenyl]-2-yl)-2,2'-diphenyl-lH,l'H-4,4'- biphenylazimide (50 mg, 60 μιηοΐ, 12%, 96% purity) as a white solid.

[0467] Synthesis of Compound-1 of the present application: A mixture of l,l'-bis(5-(tert- butyl)-[l,l'-biphenyl]-2-yl)-2,2'-diphenyl-lH,l'H-4,4'-biphenylazimide (25.00 mg, 1 eq, 31.13 μιηοΐ) and platinum precursor (1 eq, 31.13 μιηοΐ) was evacuated and backfilled with nitrogen. Organic solvent (3.000 mL) was added and the reaction was heated at reflux for 18 h. After removal of the solvent, the crude product was chromatographed to afford the compound of the present application (35% yield).

[0468] Synthesis of compound-2 of the present application:

[0469] Synthesis of 3-bromo-N-(2,6-diisopropylphenyl)-4-fluoro-2-nitroaniline: To a solution of 3-bromo-N-(2,6-diisopropylphenyl)-4-fluoro-2-nitroaniline (2.35 g, 1 eq, 5.945 mmol) in THF (40 mL), AcOH (10 mL) and NH4Cl (saturated aqueous solution, 10 mL) was added Zn powder (1.944 g, 5 eq, 29.73 mmol) at 0 °C (ice water bath). The mixture was then stirred from 0 °C to room temperature for 4 h. The mixture was filtered through celite and washed with EtOAc (40 mL). To the filtrate was added saturated Na2CO3 solution slowly until the pH reached 12. The mixture was extracted with CH2Cl2(3 x 30 mL) and dried over MgSO4. After evaporation of the solvent under a rotary evaporator, the residue was purified by column chromatography to give the aniline compound as a brown oil (1.689 g, 78% yield).

[0470] Synthesis of 3-bromo-N-(2,6-diisopropylphenyl)-4-fluoro-2-nitroaniline: To a solution of 3-bromo-N-(2,6-diisopropylphenyl)-4-fluoro-2-nitroaniline (2.35 g, 1 eq, 5.945 mmol) in THF (40 mL), AcOH (10 mL) and NH4Cl (saturated aqueous solution, 10 mL) was added Zn powder (1.944 g, 5 eq, 29.73 mmol) at 0 °C (ice water bath). The mixture was then stirred from 0 °C to room temperature for 4 h. The mixture was filtered through celite and washed with EtOAc (40 mL). To the filtrate was added saturated Na2CO3 solution slowly until the pH reached 12. The mixture was extracted with CH2Cl2(3 x 30 mL) and dried over MgSO4. After evaporation of the solvent under a rotary evaporator, the residue was purified by column chromatography to give the aniline compound as a brown oil (1.689 g, 78% yield).

[0471] Synthesis of 4-bromo-l-(2,6-diisopropylphenyl)-5-fluoro-2-phenyl-lH- benzo[d]imidazole: To a solution of 3-bromo-Nl-(2,6-diisopropylphenyl)-4- fluorobenzene-l,2-diamine (1.689 g, 1 equiv, 4.624 mmol) in DMF (40 mL) was added benzaldehyde (0.7 mL, 1.5 equiv, 6.936 mmol) and NaHS03(1.203 g, 2.5 equiv, 11.56 mmol). The headspace of the flask was flushed with N2for 5 minutes. The reaction mixture was then heated at 130 °C under N2atmosphere for 24 hours. After cooling to room temperature, the reaction mixture was diluted with water (40 mL) and ethyl acetate (40 mL). The organic phase was separated and the aqueous phase was extracted with additional EtOAc (3 x 30 mL). The combined organics were dried over MgS04, filtered and concentrated in vacuo. The residue was purified by column chromatography to give the desired compound as a white solid (1.06 g, 51% yield).

[0472] Synthesis of l-(2,6-diisopropylphenyl)-5-fluoro-2-phenyl-4-(4,4,5,5-tetramethyl- 1,3,2-dioxaborolan-2-yl)-lH-benzo[d]imidazole: A mixture of 4-bromo-l-(2,6- diisopropylphenyl)-5-fluoro-2-phenyl-lH-benzo[d]imidazole (2.35 g, 1 equiv, 5.206 mmol), 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(l,3,2-dioxaborolane) (1.719 g, 1.3 equiv, 6.768 mmol), KOAc (1.533 g, 3 equiv, 15.62 mmol), Pd(OAc)2(0.234 g, 0.2 equiv, 1.041 mmol) and BINAP (0.648 g, 0.2 equiv, 1.041 mmol) in toluene (60 mL) was heated to 100 °C under N2for 5 hours. After cooling to room temperature, the reaction mixture was quenched with water (50 mL) and extracted with DCM (4 x 40 mL). The organic phase was dried over MgS04and evaporated under a rotary evaporator. The residue was purified by column chromatography to give the compound as a light yellow solid (1.15 g, 44% yield).

[0473] Synthesis of 3-chloro-N-(2,6-diisopropylphenyl)-4-methoxy-2-nitroaniline: To a solution of 1-bromo-3-chloro-4-methoxy-2-nitrobenzene (10.05 g, 1 equiv, 37.72 mmol) in toluene (250 mL) was added 2,6-diisopropylaniline (7.69 g, 1.15 equiv, 43.37 mmol), Cs2C03(18.43 g, 1.5 equiv, 56.57 mmol), Pd(OAc)2(0.423 g, 0.05 equiv, 1.886 mmol) and BINAP (4.70 g, 0.2 equiv, 7.543 mmol) at room temperature. The mixture was stirred at 100 °C for 24 h. NH4CI (sat. aq. solution, 150 mL) was added. The organic layer was separated. The aqueous layer was extracted with CH2CI2(3 x 100 mL) and dried over MgS04. After evaporation, the residue was purified by column chromatography to give a dark red solid (13.31 g, 97% yield).

[0474] Synthesis of 3-chloro-N-(2,6-diisopropylphenyl)-4-methoxybenzene-1,2-diamine: To a solution of 3-chloro-N-(2,6-diisopropylphenyl)-4-methoxy-2-nitroaniline (13.31 g, 1 equiv, 36.68 mmol) in EtOH (80 mL) and THF (80 mL) was added SnCI2-2H20 (24.83 g, 3 equiv, 110.0 mol) and HCI (37%, 80 mL). The mixture was then stirred at 85 °C (oil bath temperature) overnight. After cooling to room temperature, the mixture was neutralized with 2N NaOH to pH 8-9. The mixture was extracted with CH2CI2(3 x 100 mL) and dried over MgS04. After evaporation of the solvent under a rotary evaporator, the residue was purified by column chromatography to give the desired compound as a yellow solid (10.88 g, 89% yield).

[0475] Synthesis of 4-chloro-l-(2,6-diisopropylphenyl)-5-methoxy-2-phenyl-lH- benzo[d]imidazole: To a solution of 3-chloro-Nl-(2,6-diisopropylphenyl)-4- methoxybenzene-l,2-diamine (10.88 g, 1 equiv, 32.69 mmol) in DMF (100 mL) was added benzaldehyde (5.0 mL, 1.5 equiv, 49.03 mmol) and NaHSO3(8.502 g, 2.5 equiv, 81.71 mmol). The headspace of the flask was flushed with N2for 5 minutes. The reaction mixture was then heated at 130 °C under N2atmosphere overnight. After cooling to room temperature, the reaction mixture was diluted with water (100 mL) and ethyl acetate (100 mL). The organic phase was separated and the aqueous phase was extracted with additional EtOAc (3 x 50 mL). The combined organics were dried over MgSO4, filtered and concentrated in vacuo. The residue was purified by column chromatography to give a pink solid (11.65 g, 85% yield).

[0476] Synthesis of l,l'-bis(2,6-diisopropylphenyl)-5-fluoro-5'-methoxy-2,2'- diphenyl-lH,l'H-4,4'-bibenzo[d]imidazole: A mixture of 4-chloro-l-(2,6- diisopropylphenyl)-5-methoxy-2-phenyl-lH-benzo[d]imidazole (0.967 g, 1 equiv, 2.207 mmol), l-(2,6-diisopropylphenyl)-5-fluoro-2-phenyl-4-(4,4,5,5-tetramethyl- 1,3,2-dioxaborolan-2-yl)-lH-benzo[d]imidazole (1.15 g, 1 equiv, 2.307 mmol), K3PO4(1.469 g, 3 equiv, 6.921 mmol), and Sphos-Pd-G2 (166 mg, 0.10 equiv, 0.231 mmol) in dioxane (40 mL) and H2O (8 mL) was heated to 100 °C under N2overnight. After cooling to room temperature, the reaction mixture was quenched with NH4CI (saturated aqueous solution, 50 mL) and extracted with DCM (4 x 30 mL). The organic phase was then dried over MgSO4and evaporated. The residue was purified by column chromatography to give the desired compound as a white solid (0.831 g, 48% yield).

[0477] Synthesis of 1,1 '-Bis(2,6-diisopropylphenyl)-5'-fluoro-2,2'-diphenyl-1 H,1 'H- [4,4'-biphenyl]imidazole-5-ol: To a solution of 1,1 '-bis(2,6-diisopropylphenyl)-5- fluoro-5'-methoxy-2,2'-diphenyl-1 H,1 'H-4,4'-biphenyl]imidazole (0.135 g, 1 equiv, 0.179 mmol) in CH2CI2(6 mL) at 0 °C (ice water bath temperature) was added BBr3(35 pL, 2 equiv, 0.358 mmol) dropwise. The mixture was stirred at room temperature for 18 h. MeOH (10 mL) was added slowly at 0 °C followed by Na2C03(saturated aqueous solution, 10 mL). The organic layer was separated and the aqueous layer was extracted with CH2CI2(3 x 15 mL) and dried over MgS04. After evaporation under a rotary evaporator, a yellow solid was obtained which was purified by column chromatography to give the desired compound as a white solid (94 mg, 71 % yield).

[0478] Synthesis of 3,9-Bis(2,6-diisopropylphenyl)-11-aza-2,10-diphenyl-3,9- dihydroimidazo[4',5':4,5]benzofuro[3,2-e]indole: To a solution of 1,1 '-bis(2,6- diisopropylphenyl)-5'-fluoro-2,2'-diphenyl-1 H,1 'H-[4,4'-biphenyl]imidazole-5-ol (0.728 g, 1 equiv, 0.982 mmol) in NMP (10 mL) at room temperature was added K2C03(0.697 g, 5 equiv, 4.91 mmol). The mixture was stirred at 175 °C for 18 h. After cooling to room temperature, NH4CI (saturated aqueous solution, 20 mL) was added to the mixture. The mixture was extracted with CH2CI2(3 x 15 mL), washed with H20 (2 x 20 mL) and dried over MgS04. After evaporation under a rotary evaporator, the residue was purified by column chromatography to give the pure product (576 mg, 81 % yield).

[0479] Synthesis of Compound-2 of the present invention: To an oven-dried 25 mL Schlenk tube with a stir bar was added 3,9-bis(2,6-diisopropylphenyl)-11-aza-2,10- diphenyl-3,9-dihydroimidazo[4',5':4,5]benzofuro[3,2-e]indole (206.0 mg, 1.114 equiv, 285.7 pmol) and platinum precursor (1 equiv). Organic solvent (3.000 mL) was added, then a septum was installed and purged with N2at atmospheric pressure while stirring at room temperature for 15 min. The reaction mixture was heated at 210 °C for 18 h. The reaction mixture was purified by column chromatography to give Compound-2 of the present invention (12 mg, 5 % yield).

[0480] Table 1. Photophysical properties

[0481]

[0482] Table 1 summarizes the photophysical properties of Inventive Compound-1 and Inventive Compound-2. Both compounds emit in the green region in PMMA with peaks at 524 and 516 nm. These emission peaks are suitable for different green PhOLED applications. The color tunability indicates that the features of the application can be used for color customization to meet certain device application requirements. As shown with Inventive Compound-2, the PLQY can be significantly increased by tethering the top two benzene rings, indicating the benefit obtained from rigidizing the scaffold of the application. High PLQY is one of the most important prerequisites to achieve efficient OLED devices.

[0483] Emission spectra were collected with a Horiba Fluorolog-3 spectrophotofluorimeter equipped with a Synapse Plus CCD detector. All samples were excited at 340 nm. PLQY values were measured using a Hamamatsu Quantaurus-QY Plus UV-NIR absolute PL quantum yield spectrometer with an excitation wavelength of 340 nm. A 1% emitter in PMMA solution in toluene was prepared, filtered, and drop-cast onto a quartz substrate.

Claims

1. A compound comprising a structure of Formula I: wherein n is 1, 2, 3, or 4; wherein M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Pd, Ag, Au, and Cu; wherein M can be coordinated to other ligands; wherein the compound can be joined to other ligands to constitute a penta- or hexadentate ligand; wherein any two substituents can be joined or fused to form a ring, wherein the compound is not: wherein: wherein X 1 - X 3 each independently C or N; wherein Y 2 and Y 3 each independently is selected from the group consisting of O, N, S, Se, BR, CR, CRR', NR, PR, PRR', AsRR', CRR', SiRR', and GeRR'; wherein Y 1 is selected from the group consisting of O, N, S, Se, BR, CR, CRR', NR, PR, PRR', AsRR', CRR', SiRR', and GeRR'; wherein Z 1 , Z 2 , Z 3 , and Z 4 are each independently C, CR, CRR', O, OR, N, or NR; K 1 and K 2 are each independently selected from the group consisting of a direct bond, O, S, N(R α ), P(R α ), B(R α ), C(R α )(R β ), and Si(R α )(R β ); wherein G 1 , G 2 and G 3 are each independently selected from the group consisting of CR, CRR', N and NR; 4. The compound of claim 1, wherein the compound comprises a structure selected from the group consisting of structures from List 1 below: wherein R A represents mono-substitution to the maximum allowable substitution or no substitution; wherein each R α , R β , R, R' and R A are independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfido, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein represents a single or double bond; wherein moieties B, C, D, E, F, G, and H are each independently a monocyclic ring comprising one 5- to 10-membered carbocyclic or heterocyclic ring, or a polycyclic fused ring system comprising at least two fused 5- to 10-membered carbocyclic or heterocyclic rings; 5. The compound of claim 1, wherein the compound comprises a structure selected from the group consisting of structures from List 2 below: wherein L and L’ are independently selected from the group consisting of: wherein R” is hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof; and / or provided that if K 1 and K 2 are not a direct bond, and n is 1, then X 3 and Y 2 and Y 2 and Y 3 do not simultaneously form a cyclic group; and wherein i, j, k, l, s, t, u, and v are each independently an integer from 1 to 468, and q is an integer from 2 to 468; 2. The compound of claim 1, wherein R α , R β , R, R', and R A are each independently hydrogen or a substituent selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfido, and combinations thereof; and / or wherein X 1 - X 3 are each C; and / or wherein Y 2 and Y 3 are each C.

3. The compound of claim 1, wherein Y 1 is NR, and R in NR comprises a 6-membered aromatic ring; and / or wherein Z 1 and Z 2 are N; and / or wherein G 1 - G 3 are C; and / or wherein K 1 and K 2 are direct bonds. wherein R1to R468have the following structures from List 9 as defined herein; and / or 8. The compound of claim 1, wherein the compound is selected from the group consisting of: wherein each R B , R C , R D , R E , R F , R G and R H represents mono-substitution to the maximum allowable substitution or no substitution; and wherein each R B , R C , R D , R E , R F , R G , and R H are independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfido, sulfinyl, sulfonyl, phosphino, and combinations thereof.

11. The compound of claim 1, wherein the compound is selected from the group consisting of compounds -G-(Rs)(Rt)(Ru)(Rv), wherein G is an integer from 1 to 10, and each of Rs, Rt, Ru, Rv is independently selected from R1to R468, wherein each of compounds -1-(R1)(R1)(R1)(R1) to compounds -10-(R468)(R468)(R468)(R468) is defined below in List 12: wherein X 4 - X 19 each independently C or N; and wherein Y 4 and Y 5 each independently is selected from the group consisting of O, N, S, Se, BR, CR, CRR', NR, PR, PRR', AsRR', CRR', SiRR', and GeRR'; wherein each R AA , R BB , R CC , and R DD represents single substitution to the maximum allowable substitution or no substitution; wherein each R AA , R BB , R CC , and R DD is independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfido, sulfinyl, sulfonyl, phosphino, boryl, selenoalkyl, and combinations thereof.

6. The compound of claim 1, wherein the compound is selected from the group consisting of compounds of formula Ir(L A 1 )L y 1 (L)(L'). wherein L A 1 is selected from the group consisting of the following structures from List 3 below: and Ly 1 selected from the group consisting of the following structures from List 4:

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

13. An organic light emitting device (OLED) comprising: an anode; a cathode; and an organic layer disposed between the anode and the cathode, wherein said compound is selected from the group consisting of compounds of formula Ir(L A 2 )L y 2 (L)(L') of the following formulae: wherein L A 2 is selected from the group consisting of the following structures from List 5 below: and L y 2 is selected from the group consisting of the following structures from List 6:

7. The compound of claim 1, wherein the compound is selected from the group consisting of compounds of formula Ir(L A 1 )L y 1 (L)(L'). wherein L A 1 selected from the group consisting of L A 1 -1-(Rq)(Rj)(Rk)(Rl) and L A 1 -W-(Ri)(Rj)(Rk)(Rl), wherein W is an integer from 2 to 8, and Rq is selected from R2 to R468, each of Ri, Rj, Rk, Rl is independently selected from R1 to R468, wherein L A 1 -1-(R2)(R1)(R1)(R1) to L A 1 -1-(R468)(R468)(R468)(R468) and L A 1 -2-(R1)(R1)(R1)(R1) to L A 1 -8-(R468)(R468)(R468)(R468) each of which is defined in the following List 7: wherein Ly 1 is selected from the group consisting of Ly 1 - Q-(Rs)(Rt)(Ru)(Rv), wherein Q is an integer from 1 to 10, and each of Rs, R1, Ru, Rv is independently selected from R1 to R468, wherein Ly 1 - 1-(R1)(R1)(R1)(R1) to Ly 1 - 10-(R468)(R468)(R468)(R468) are defined in the following List 8: wherein the organic layer contains a compound comprising a structure of Formula I: wherein n is 1, 2, 3, or 4; wherein M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Pd, Ag, Au, and Cu; wherein M can be coordinated to other ligands; wherein the compound can be joined to other ligands to constitute a penta- or hexadentate ligand; wherein any two substituents can be joined or fused to form a ring, wherein the compound is not: wherein: wherein said compound is selected from the group consisting of compounds of formula Ir(L A 2 )L y 2 (L)(L') of the following formulae: wherein L A 2 selected from the group consisting of L A 2 - W' - (Ri)(Rj)(Rk)(Rl), where W' is an integer from 1 to 20, each of Ri, Rj, Rk, Rl is independently selected from R1 to R468, wherein L A 2 - each of 1 - (R1)(R1)(R1)(R1) to L A 2 - each of 20 - (R468)(R468)(R468)(R468) is selected from the group consisting of the following structures from List 10 below: wherein Ly 2 is selected from the group consisting of Ly 2 - Q'-(Rs)(Rt)(Ru)(Rv), wherein Q' is an integer from 1 to 13, and each of Rs, Rt, Ru, Rv is independently selected from R1 to R468, wherein Ly 2 - 1-(R1)(R1)(R1)(R1) to Ly 2 - 13-(R468)(R468)(R468)(R468) are defined in the following list 11: wherein: each of J1to J6is independently C or N; 9. The compound of claim 1, wherein the compound is selected from the group consisting of compounds of formulae Pt(L A 1 )(Ly 1 ) wherein if L A 1 Lyis selected from the group consisting of the structures in List 3 1 is selected from the group consisting of the structures in List 4; and wherein if L A 1 is selected from the group consisting of the structures in List 7, then Ly 1 is selected from the group consisting of the structures in List 8.

10. The compound of claim 1, wherein the compound is selected from the group consisting of compounds of formulae Pt(L A 2 )(Ly 2 ) wherein if L A 2 selected from the group consisting of the structures in List 5, then Ly 2 selected from the group consisting of the structures in List 6; and wherein if L A 2 is selected from the group consisting of the structures in List 10, then Ly 2 is selected from the group consisting of the structures in List 11. ​ ​ ​ ​ ​ ​ ​ wherein X 1 - X 3 each independently C or N; wherein Y 2 and Y 3 each independently is selected from the group consisting of O, N, S, Se, BR, CR, CRR', NR, PR, PRR', AsRR', CRR', SiRR', and GeRR'; wherein Y 1 is selected from the group consisting of O, N, S, Se, BR, CR, CRR', NR, PR, PRR', AsRR', CRR', SiRR', and GeRR'. wherein Z 1 , Z 2 , Z 3 and Z 4 are each independently C, CR, CRR', O, OR, N, or NR; K 1 and K 2 are each independently selected from the group consisting of a direct bond, O, S, N(R α ), P(R α ), B(R α ), C(R α )(R β ), and Si(R α )(R β ); wherein G 1 , G 2 and G 3 are each independently selected from the group consisting of CR, CRR', N and NR; ​ wherein R A represents mono-substitution to the maximum allowable substitution or no substitution; wherein each R α , R β , R, R' and R A are independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfido, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein represents a single or double bond; ​ ​ ​ ​ provided that if K 1 and K 2 are not a direct bond, and n is 1, then X 3 and Y 2 and Y 2 and Y 3 do not simultaneously form a cyclic group; and ​ 14. The OLED of claim 13, wherein the organic layer further comprises a host, wherein the host comprises at least one chemical moiety selected from the group consisting of: triphenylene, carbazole, indolocarbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, 5λ 2 - benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-borafluorene, azacyclohexylborane, oxaborabenzene, dihydroacridine, xanthene, dihydrobenzoazasiline, dibenzooxasiline, phenoxazine, phenoxathiine, phenothiazine, dihydrophenoxazine, fluorene, naphthalene, anthracene, phenanthrene, phenanthroline, benzochinoline, quinoline, isoquinoline, quinazoline, pyrimidine, pyrazine, pyridine, triazine, borane group, silane group, aza-triphenylene, aza-carbazole, aza-indolocarbazole, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene, aza-5λ 2 - benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-borafluorene, azacyclohexylborane, oxaborabenzene, dihydroacridine, xanthene, dihydrobenzoazasiline, dibenzooxasiline, phenoxazine, phenoxathiine, phenothiazine, dihydrophenoxazine, fluorene, naphthalene, anthracene, phenanthrene, phenanthroline, benzochinoline, quinoline, isoquinoline, quinazoline, pyrimidine, pyrazine, pyridine, triazine, borane group, silane group, aza-triphenylene, aza-carbazole, aza-indolocarbazole, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene, aza-5λ ​ ​ L' is a direct bond or an organic linking group; each Y AA , Y BB , Y CC and Y DD is independently selected from the group consisting of no bond, a direct bond, O, S, Se, CRR', SiRR', GeRR', NR, BR, BRR'; R A' , R B' , R C' , R D' , R E' , R F' , and R G' each independently represents mono-substitution, up to the maximum substitution, or no substitution; each R, R', R A' , R B' , R C' , R D' , R E' , R F' , and R G' are independently hydrogen or a substituent selected from the group consisting of the generic substituents as defined herein; any two substituents can be joined or fused to form a ring; and, where possible, each unsubstituted aromatic carbon atom is optionally replaced with N to form a nitrogen substituted ring.

15. A consumer product comprising an organic light emitting device (OLED), the OLED comprising: an anode; a cathode; and an organic layer disposed between the anode and the cathode, wherein the organic layer contains a compound comprising the structure of Formula I: wherein X 1 - X 3 each independently C or N; wherein Y 2 and Y 3 each independently is selected from the group consisting of O, N, S, Se, BR, CR, CRR', NR, PR, PRR', AsRR', CRR', SiRR', and GeRR'; wherein Y 1 is selected from the group consisting of O, N, S, Se, BR, CR, CRR', NR, PR, PRR', AsRR', CRR', SiRR', and GeRR'. wherein Z 1 , Z 2 , Z 3 , and Z 4 are each independently C, CR, CRR', O, OR, N, or NR; K 1 and K 2 are each independently selected from the group consisting of a direct bond, O, S, N(R α ), P(R α ), B(R α ), C(R α )(R β ), and Si(R α )(R β ); wherein G 1 , G 2 and G 3 are each independently selected from the group consisting of CR, CRR', N and NR; where n is 1, 2, 3, or 4; wherein R A represents mono-substitution to the maximum allowable substitution or no substitution; wherein each R α , R β , R, R' and R A are independently hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfido, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein represents a single or double bond; where M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Pd, Ag, Au, and Cu; where M can coordinate with other ligands; where the compound can engage with other ligands to constitute a penta- or hexadentate ligand; where any two substituents can engage or fuse to form a ring, provided that if K 1 and K 2 are not a direct bond, and n is 1, then X 3 and Y 2 and Y 2 and Y 3 do not simultaneously form a cyclic group; and where the compound is not:

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