Organic electroluminescent materials and devices

Abstract

The invention relates to organic electroluminescent materials and devices. An organometallic compound is provided comprising a platinum or palladium atom as a central metal atom coordinated by a tetradentate ligand. Formulations comprising these organometallic compounds are also provided. Further provided are organic light emitting devices (OLED) and related consumer products utilizing these organometallic compounds.

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 / 657,165, filed June 7, 2024, and U.S. Provisional Application No. 63 / 643,502, filed May 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 inorganic 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. Alternatively, a single emissive layer can be designed to emit white light. White light is a combination of all primary colors. Display applications for OLEDs include full color displays. OLEDs can also be useful in applications such as lighting. SUMMARY

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

[0008]

[0009] wherein M is Pt or Pd;

[0010] wherein moiety A is a monocyclic or polycyclic fused ring system, wherein each ring in the monocyclic or the polycyclic fused ring system is independently a 5- to 10-membered carbocyclic or heterocyclic ring;

[0011] wherein X 1 - X 8 each independently is C or N;

[0012] Z 1 and Z 2 each independently is C or N;

[0013] wherein K 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 );

[0014] wherein L is selected from the group consisting of a direct bond, O, S, Se, NR, BR, BRR', PR, CR, C=O, C=NR, C=CRR', C=S, CRR', SO, SO2, P(O)R, SiRR', and GeRR';

[0015] wherein R 1 is a substituted or unsubstituted carbocyclic or heterocyclic group;

[0016] wherein R A , R B , and R C each independently represents mono-substitution to the maximum allowable substitution or no substitution;

[0017] wherein each R α , R β , R, R', R 2 , R A , R B , and R C 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;

[0018] wherein at least one of the following conditions is true:

[0019] (1) at least one R A is R * , wherein R* is a substituted carbocyclic or heterocyclic group, and R 1 and R * the total number of ring groups contained by R

[0020] (2) at least one R A substituent is a non-hydrogen substituent and is bonded to a ring carbon atom contained by moiety A, with the proviso that the substituent is not 2,5-diisopropylphenyl;

[0021] (3) L is CR, and R 2 are bonded to form a benzene ring having at least one non-hydrogen substituent not contained by ring D; and

[0022] (4) at least one R B substituent is not hydrogen.

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

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

[0025] In yet another aspect, the present 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 is shown that does not have a separate electron transport layer. 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 would be 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 an energy level closer to the top of such a diagram than by a "lower" HOMO or LUMO energy level.

[0033] As used herein, and as would be understood by one of ordinary skill in the art, a first work function is "greater than" or "higher than" a second work function if the first work function has a higher absolute value. Since work 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 a -SeR s group.

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

[0047] The term "sulfonyl" refers to a -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 alkyl carbon atoms bonded to the relevant structure. Preferred alkyl groups are alkyl groups containing one to fifteen carbon atoms, preferably one to nine carbon atoms, and include methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-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 a cycloalkyl carbon atom bonded to the relevant structure. Preferably, cycloalkyl is a cycloalkyl group containing from 3 to 12 ring carbon atoms and includes cyclopropyl, cyclopentyl, cyclohexyl, bicyclo[3.1.1]heptyl, spiro[4.5]decyl, spiro[5.5]undecyl, adamantyl, and the like. Additionally, the cycloalkyl group can be further substituted.

[0055] The term "heteroalkyl" or "heterocycloalkyl" means and includes an alkyl or cycloalkyl group, 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 those 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 groups can be further substituted or fused.

[0060] The term "aryl" means and includes both monocyclic and polycyclic aromatic hydrocarbon groups. Polycyclic rings can have two or more rings, in which two carbons are common to two adjacent 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, naphthyl, anthracenyl, azulenyl, phenanthrenyl, pyrenyl, perylene, and azulene, preferably phenyl, biphenyl, terphenyl, triphenylene, and naphthyl. Additionally, the 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 heterocyclic systems can have two or more aromatic rings, where two atoms are common to two adjacent rings (the rings are "fused"), where at least one of the rings is heteroaryl. Polycyclic heteroaromatic ring systems can have one to six heteroatoms in each ring of the polycyclic aromatic ring system. Preferred heteroaryls are heteroaryls 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 heteroaryls 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, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazol, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furopyridine, benzothienopyridine, thienopyridine, benzoselenophenopyridine, selenophenopyridine, azaborine, borazine, 5λ 2 ,9λ 2 -diazaboro-13b-naphthacene, 5λ 2 -benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, and 5,9-dioxa-13b-boronoranthrene; preferably dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 5λ 2 ,9λ 2 -diazaboro-13b-naphthacene, 5λ 2 -benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, and 5,9-dioxa-13b-boronoranthrene. Additionally, the heteroaryl groups 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-bora-naphtho[2,3,4-de]anthracene, 5λ 2 - benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-bora- naphtho[3,2,1-de]anthracene, and each of their corresponding aza analogs are of particular interest.

[0063] In many cases, preferred 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 cases, 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.

[0065] In some cases, even more preferred generic substituents are selected from the group consisting of deuterium, fluorine, alkyl, cycloalkyl, silyl, aryl, heteroaryl, nitrile, and combinations thereof.

[0066] In yet other cases, most preferred generic substituents are selected from the group consisting of deuterium, alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.

[0067] In yet other cases, most preferred generic substituents are selected from the group consisting of deuterium, alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.

[0068] The terms "substituted" and "substitution" mean that a substituent other than H is bonded to the relevant position, e.g., carbon or nitrogen. For example, when R 1 represents mono-substitution, then one R 1 must be other than H (i.e., substitution). Similarly, when R 1 represents di-substitution, then two R 1 must be other than H. Similarly, when R 1 represents zero or no substitution, R 1 For example, can be hydrogen for all available valences of a ring atom, such as the carbon atoms of benzene and the nitrogen atom in pyrrole, or represent nothing for a ring atom with a fully saturated valence, such as the nitrogen atom in pyridine. The maximum number of substitutions possible 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 one of ordinary skill in the art could envision from the applicable list. For example, alkyl and deuterium can be combined to form a partially or fully deuterated alkyl group; halogen and alkyl can be combined to form a haloalkyl substituent; and halogen, alkyl, and aryl can be combined to form a haloaralkyl group. In one example, the term substituted includes combinations of two to four of the listed groups. In another example, the term substituted includes combinations of two to three groups. In yet another example, the term substituted includes combinations of two groups. Preferred combinations of substituents are combinations containing up to fifty atoms that are not hydrogen or deuterium, or combinations including up to forty atoms that are not hydrogen or deuterium, or combinations including 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 "aza" designation in fragments described herein, i.e., aza-dibenzofurans, aza- dibenzothiophenes, and the like, means that one or more of the C-H groups in the corresponding aromatic ring can be replaced with a nitrogen atom, for example and without any limitation, aza-triphenylenes encompass dibenzo[f,h]quinoxaline and dibenzo[f,h]quinoline. Other nitrogen analogs of the aza-derivatives described above can be readily envisioned by one of ordinary skill in the art, and all such analogs are intended to be encompassed by the term as set forth herein.

[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 routes to deuterate methylene hydrogens in benzyl amines and replace 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 non-deuterated, partially deuterated, as well as fully deuterated versions thereof. Similarly, classes of substituents such as, but not limited to, alkyl, aryl, cycloalkyl, heteroaryl, and the like, also include non-deuterated, partially deuterated, as well as fully deuterated versions thereof. Unless otherwise specified, no atom in a chemical structure that has a valence of fully filled by either H or D should be considered to include only its non-deuterated, partially deuterated, and fully deuterated versions. For example, a chemical structure means to include C6H6, C6D6, C6H3D3, and any other partially deuterated variant thereof. Some common, substantially 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, dibenzofuranyl) 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 biphenyl or the 1,8 positions in 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 M is Pt or Pd;

[0079] wherein moiety A is a monocyclic or polycyclic fused ring system, wherein each ring in the monocyclic or the polycyclic fused ring system is independently a 5- to 10-membered carbocyclic or heterocyclic ring;

[0080] wherein X 1 -X 8 are each independently C or N;

[0081] Z 1 and Z 2each independently C or N;

[0082] wherein K 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 L is selected from the group consisting of a direct bond, O, S, Se, NR, BR, BRR', PR, CR, C=O, C=NR, C=CRR', C=S, CRR', SO, SO2, P(O)R, SiRR', and GeRR';

[0084] wherein R 1 is a substituted or unsubstituted carbocyclic or heterocyclic group;

[0085] wherein R A , R B , and R C each independently represent mono-substitution to the maximum allowable substitution or no substitution; and

[0086] wherein each R α , R β , R, R', R 2 , R A , R B , and R C 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.

[0087] In some embodiments, at least one of the following conditions is true:

[0088] (1) at least one R A is R * , wherein R * is a substituted carbocyclic or heterocyclic group, and the total number of ring groups contained by R 1 and R * is three or more;

[0089] (2) at least one R A substituent is a non-hydrogen substituent and is bonded to a ring carbon atom contained by moiety A, with the proviso that the substituent is not 2,5-diisopropylphenyl;

[0090] (3) L is CR, and R and R 2 are joined to form a benzene ring having at least one non-hydrogen substituent not included in ring D; and

[0091] (4) at least one R B is not hydrogen.

[0092] In some embodiments, two R A substituents or two R B substituents are joined together to form a cyano-substituted benzofuran ring.

[0093] Although Formula I depicts Z 1 and Z 2 as connected by a single line, depending on the structure of the relevant ring of moiety A, Z 1 and Z 2 may be joined by any appropriate bond in the Lewis structure (e.g., single bond, double bond, etc.). It should be understood that the same rules apply to the bonds between atoms of other generic rings disclosed herein, unless stated to the contrary.

[0094] In some embodiments, the compound consists essentially of Formula I.

[0095] In some embodiments, the compound has the structure of Formula I.

[0096] In some embodiments, each of R α , R β , R, R', R 2 , R A , R B , and R C is 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, thio, and combinations thereof.

[0097] In some embodiments, M is Pt.

[0098] In some embodiments, M is Pd.

[0099] In some embodiments, K is not a direct bond.

[0100] In some embodiments, K is O.

[0101] In some embodiments, K is a direct bond.

[0102] In some embodiments, L is not a direct bond.

[0103] In some embodiments, L is CRR'.

[0104] In some embodiments, L is CRR', and R and R' engage with ring D.

[0105] In some embodiments, L is CRR', and R and R' are engaged with ring D to form a 6-membered ring.

[0106] In some embodiments, L is CRR', and R and R' are coupled to ring D to form a 6-membered aromatic ring.

[0107] In some embodiments, L is CRR', and R and R' are bonded to ring D to form a 6-membered aromatic carbon ring.

[0108] In some embodiments, L is a direct key.

[0109] In some embodiments, Z 1 and Z 2 One of them is N.

[0110] In some embodiments, Z 1 It is N.

[0111] In some embodiments, Z 2 It is N.

[0112] In some embodiments, X 1 -X 8 At least one of them is N.

[0113] In some embodiments, X 1 -X 8 One of them is N.

[0114] In some embodiments, X 1 -X 4 At least one of them is N.

[0115] In some embodiments, X 1 -X 4 One of them is N.

[0116] In some embodiments, X 5 -X 8 At least one of them is N.

[0117] In some embodiments, X 5 -X 8 One of them is N.

[0118] In some embodiments, X 1 -X 8 At least two of them are N.

[0119] In some embodiments, X 1 -X 8 All of them are C.

[0120] In some embodiments, R 1 Included II The structure; ring G is a 5- to 10-membered carbon ring or heterocycle; where R G Indicates monosubstituted to trisubstituted or unsubstituted; where each R 1' R 2' and R G 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, selenyl and combinations thereof; and wherein R 1' or R 2' At least one of them is not hydrogen or deuterium.

[0121] In some embodiments, ring G is a 5- or 6-membered carbocyclic ring or a heterocyclic ring. Ring G is a 5- or 6-membered aryl or heteroaryl ring. In some embodiments, R 1' and R 2' Neither is hydrogen or deuterium. In some embodiments, R 1' and R 2' Each of these is independently selected from the group consisting of: alkyl, cycloalkyl, aryl, heteroaryl, silyl, germanyl, and combinations thereof. In some embodiments, R 1' and R 2' Same; R 1' and R 2' Different. In some embodiments, R 1' and R 2' Each of them contains at least one carbon atom. In some embodiments, R 1' and R 2' Each of them contains at least two carbon atoms. In some embodiments, R 1' and R 2' Each of them contains at least 3 carbon atoms. In some embodiments, R 1' and R 2' Each of them contains at least 4 carbon atoms. In some embodiments, R 1' and R 2' Each of them contains at least 5 carbon atoms.

[0122] In some embodiments, at least one R G Not hydrogen or deuterium. In some embodiments, at least one R Galkyl, cycloalkyl, aryl, heteroaryl, silyl, germyl, and combinations thereof.

[0123] In some embodiments, ring G is selected from the group consisting of benzene, pyridine, pyrimidine, pyridazine, pyrazine, triazine, imidazole, imidazole- derived carbene, pyrazole, pyrrole, oxazole, furan, thiophene, thiazole, and triazole.

[0124] In some embodiments, at least one R 1 comprises a structure of Formula IIA 1a 2a 3a each of X

[0125] In some embodiments, R 1a bonded to X G is selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, silyl, germyl, and combinations thereof. In some embodiments, R 1a bonded to X G is selected from the group consisting of alkyl, aryl, heteroaryl, silyl, and germyl. In some embodiments, each of X 2a , X G , and X 2a is C. G

[0126] In some embodiments, R 3a bonded to X G is selected from the group consisting of alkyl, cycloalkyl, aryl, heteroaryl, silyl, germyl, and combinations thereof. In some embodiments, R 3a bonded to X G is selected from the group consisting of alkyl, aryl, heteroaryl, silyl, and germyl. In some embodiments, each of X 1a , X 2a , and X 3a is C.

[0127] In some embodiments of Formula I, at least one R, R', R α , R β , R A , R B , R C , R 1 , R 2 , or R 3 ​​​​are partially or fully deuterated. In some embodiments, at least one R A are partially or fully deuterated. In some embodiments, at least one R B are partially or fully deuterated. In some embodiments, at least one R C are partially or fully deuterated. In some embodiments, at least one R 1 are partially or fully deuterated. In some embodiments, at least one R 2 are partially or fully deuterated. In some embodiments, at least one R 3 are 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.

[0128] In some embodiments, at least one of R, R', R α , R β , R A , R B , R C , R 1 , R 2 or R 3 is a substituent selected from the group of generic substituents defined herein. In some embodiments, at least one of R or R' is selected from the group of generic substituents defined herein. In some embodiments, at least one of R α or R β is selected from the group of generic substituents defined herein. In some embodiments, at least one R A is selected from the group of generic substituents defined herein. In some embodiments, at least one R B is selected from the group of generic substituents defined herein. In some embodiments, at least one R C is selected from the group of generic substituents defined herein. In some embodiments, at least one R 1 is selected from the group of generic substituents defined herein. In some embodiments, at least one R 2 is selected from the group of generic substituents defined herein. In some embodiments, at least one R 3 is selected from the group of generic substituents defined herein.

[0129] In some embodiments, at least one of R, R', R α , R β , R A , R B , R C , R 1, R 2 or at least one of R 3 is a substituent selected from the group consisting of the preferred general substituents defined herein. In some embodiments, at least one of R or R' is selected from the group consisting of the preferred general substituents defined herein. In some embodiments, at least one of R α or R β is a substituent selected from the group consisting of the preferred general substituents defined herein. In some embodiments, at least one R A is selected from the group consisting of the preferred general substituents defined herein. In some embodiments, at least one R B is selected from the group consisting of the preferred general substituents defined herein. In some embodiments, at least one R C is selected from the group consisting of the preferred general substituents defined herein. In some embodiments, at least one R 1 is selected from the group consisting of the preferred general substituents defined herein. In some embodiments, at least one R 2 is selected from the group consisting of the preferred general substituents defined herein. In some embodiments, at least one R 3 is selected from the group consisting of the preferred general substituents defined herein.

[0130] In some embodiments, moiety A is independently selected from the group consisting of the following cyclic moieties: benzene, pyridine, pyrimidine, pyridazine, pyrazine, triazine, imidazole, imidazole-derived carbene, 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, benzimidazole-derived carbene, azabenzimidazole-derived carbene, azabenzimidazole, carbazole, azacarbazole, diphenylene furan, azadiphenylene furan, diphenylene thiophene, azadiphenylene thiophene, quinoxaline, phtalazine, phenanthrene, azaphenanthrene, anthracene, azanthracene, phenanthridine, fluorene, and azaf luorene.

[0131] In some embodiments, moiety A is monocyclic.

[0132] In some embodiments, moiety A is selected from the group consisting of benzene, pyridine, pyrimidine, pyridazine, pyrazine, triazine, imidazole, imidazole-derived carbene, pyrazole, pyrrole, oxazole, furan, thiophene, thiazole, and triazole.

[0133] In some embodiments, moiety A is pyridine or imidazole.

[0134] In some embodiments, moiety A is a polycyclic fused ring system.

[0135] In some embodiments, moiety A is selected from the group consisting of naphthalene, quinoline, isoquinoline, quinazoline, benzofuran, azabenzofuran, benzoxazole, azabenzoxazole, benzothiophene, azabenzothiophene, benzothiazole, azabenzothiazole, benzoselenophene, azabenzoselenophene, indene, azaindene, indole, azaindole, benzimidazole, benzimidazole-derived carbene, azabenzimidazole, carbazole, azacarbazole, diphenylene, azadiphenylene, dithiophene, azadithiophene, quinoxaline, phthalazine, phenanthrene, azaphenanthrene, anthracene, azanthracene, phenanthridine, fluorene, and azafiuorene.

[0136] In some embodiments, moiety A is benzimidazole.

[0137] In some embodiments, moiety A comprises a heterocycle.

[0138] In some embodiments, moiety A comprises a heterocyclic aromatic ring.

[0139] In some embodiments, moiety A comprises a 5-membered heterocyclic aromatic ring.

[0140] In some embodiments, moiety A comprises a 6-membered heterocyclic aromatic ring.

[0141] In some embodiments, moiety A is a heterocycle.

[0142] In some embodiments, moiety A is a heterocyclic aromatic ring.

[0143] In some embodiments, moiety A is a 5-membered heterocyclic aromatic ring.

[0144] In some embodiments, moiety A is a 6-membered heterocyclic aromatic ring.

[0145] In some embodiments, R 1 comprises at least one 6-membered ring.

[0146] In some embodiments, R 1 comprises at least one 6-membered aromatic ring.

[0147] In some embodiments, R 1 comprises at least two 6-membered rings.

[0148] In some embodiments, R 1 comprises at least two 6-membered aromatic rings.

[0149] In some embodiments, R 1 comprises at least one alkyl group.

[0150] In some embodiments, R 1 comprises at least two alkyl groups.

[0151] In some embodiments, R 1 comprises at least one isopropyl or tert-butyl group.

[0152] In some embodiments, R 1 comprises at least two isopropyl or tert-butyl groups.

[0153] In some embodiments, R 2 is not hydrogen.

[0154] In some embodiments, R 2 is CRR'.

[0155] In some embodiments, exactly one R A is hydrogen.

[0156] In some embodiments, at least one R A is an alkyl group.

[0157] In some embodiments, exactly one R A is an alkyl group.

[0158] In some embodiments, at least one R A comprises a 6-membered ring.

[0159] In some embodiments, at least one R A comprises a 6-membered aromatic ring.

[0160] In some embodiments, all R B are hydrogen.

[0161] In some embodiments, at least one R B substituent is not hydrogen.

[0162] In some embodiments, all R C are hydrogen.

[0163] In some embodiments, at least one R C substituent is not hydrogen.

[0164] In some embodiments, at least one R A is R * , wherein R * is a substituted carbocyclic or heterocyclic group, and the total number of ring groups comprised by R 1 and R * is three or more.

[0165] In some embodiments, at least one R A substituent is a non-hydrogen substituent and is bonded to a ring carbon atom comprised by moiety A, with the proviso that the substituent is not a 2,5-diisopropylphenyl group.

[0166] In some embodiments, L is CR, and R and R 2 bonded to form a benzene ring having at least one non-hydrogen substituent not included in ring D.

[0167] In some embodiments, the compound of Formula I comprises an electron- withdrawing group. In some embodiments, the electron-withdrawing group has a Hammett constant greater than 0. In some embodiments, the electron-withdrawing group has a Hammett constant 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.

[0168] In some embodiments, the compound of Formula I comprises an electron- withdrawing group selected from the group consisting of the following list of EWG1: 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 diphenyldiborolyl, 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,

[0169] wherein each R k1 represents mono-substitution to the maximum allowable substitution or no substitution;

[0170] wherein Y G is selected from the group consisting of: BR e , NR e , PRe O, S, Se, C=0, S=0, S02, CR e R f , SiR e R f , and GeR e R f' ; and

[0171] wherein 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.

[0172] In some embodiments, the compound of Formula I comprises an electron- withdrawing group selected from the group consisting of the structures in the following list of EWG2:

[0173] In some embodiments, the compound of Formula I comprises an electron- withdrawing group selected from the group consisting of the structures in the following list of EWG3:

[0174] In some embodiments, the compound of Formula I comprises an electron- withdrawing group selected from the group consisting of the structures in the following list of EWG4:

[0175] In some embodiments, the compound of Formula I comprises an electron- withdrawing group that is a pi-electron deficient electron- withdrawing group. In some embodiments, the pi-electron deficient electron- withdrawing group is selected from the group consisting of the structures in the following list of Pi-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, BR k2 R k3substituted or unsubstituted thiophene, substituted or unsubstituted furan, substituted or unsubstituted pyrrole, substituted or unsubstituted indole, substituted or unsubstituted indolizine, substituted or unsubstituted indene, substituted or unsubstituted indoline, substituted or unsubstituted isoindole, substituted or unsubstituted isoindoline, substituted or unsubstituted isoindazene, substituted or unsubstituted benzofuran, substituted or unsubstituted benzothiophene, substituted or unsubstituted benzocyclobutene, substituted or unsubstituted benzodihydrocyclopenta[ b ]indole, substituted or unsubstituted dibenzofurane, 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 benzoimidazole, ketone, carboxylic acid, ester, nitrile, isonitrile, sulfinyl, sulfonyl, partially and fully fluorinated aryl, partially and fully fluorinated heteroaryl, cyano-containing aryl, cyano-containing heteroaryl, isocyanate, wherein the variables are the same as previously defined.

[0176] In some embodiments, the compound of Formula I comprises an electron- withdrawing group from the list of EWG1 defined herein. In some embodiments, the compound comprises an electron-withdrawing group from the list of EWG2 defined herein. In some embodiments, the compound of Formula I comprises an electron- withdrawing group from the list of EWG3 defined herein. In some embodiments, the compound of Formula I comprises an electron- withdrawing group from the list of EWG4 defined herein. In some embodiments, the compound of Formula I comprises an electron- withdrawing group from the list of Pi-EWG defined herein.

[0177] In some embodiments, in the compound of Formula I, at least one R A is or comprises an electron-withdrawing group. In some embodiments, at least one R A is or comprises an electron-withdrawing group from the list of EWG1 defined herein. In some embodiments, at least one R A is or comprises an electron-withdrawing group from the list of EWG2 defined herein. In some embodiments, at least one R A is or comprises an electron-withdrawing group from the list of EWG3 defined herein. In some embodiments, at least one R A is or comprises an electron-withdrawing group from the list of EWG4 defined herein. In some embodiments, at least one R A is or comprises an electron-withdrawing group from the list of Pi-EWG defined herein.

[0178] In some embodiments, in the compound of Formula I, at least one R B is or comprises an electron-withdrawing group. In some embodiments, at least one R B is or comprises an electron-withdrawing group from the list of EWG1 defined herein. In some embodiments, at least one R Bis or comprises an electron withdrawing group from the list of EWG1 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 Pi-EWG as defined herein.

[0179] In some embodiments, in the compound of formula I, 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 Pi-EWG as defined herein.

[0180] In some embodiments, in the compound of formula I, R 2 is or comprises an electron withdrawing group from the list of EWG1 as defined herein. In some embodiments, R 2 is or comprises an electron withdrawing group from the list of EWG2 as defined herein. In some embodiments, R 2 is or comprises an electron withdrawing group from the list of EWG3 as defined herein. In some embodiments, R 2 is or comprises an electron withdrawing group from the list of EWG4 as defined herein. In some embodiments, R 2 is or comprises an electron withdrawing group from the list of Pi-EWG as defined herein.

[0181] 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 Pi-EWG as defined herein.

[0182] In some embodiments, the compound is selected from the group consisting of:

[0183]

[0184] wherein

[0185] X 9 -X 18 each independently is C or N;

[0186] Y B is selected from the group consisting of BR, BRR', NR, PR, P(O)R, O, S, Se, C=O, C=S, C=Se, C=NR', C=CRR', S=O, SO2, CR, CRR', SiRR', and GeRR';

[0187] L' is selected from the group consisting of a direct bond, O, S, Se, NR, BR, BRR', PR, CR, C=O, C=NR, C=CRR', C=S, CRR', SO, SO2, P(O)R, SiRR', and GeRR';

[0188] R AA , R BB , and R D each independently represents mono-substitution to the maximum allowable substitution or no substitution;

[0189] each R 3 , R 4 , R AA , R BB , and R D 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; and any two substituents can be joined or fused to form a ring.

[0190] In some embodiments, at least one R AA is or comprises an electron- withdrawing group from the list of EWG1 defined herein. In some embodiments, at least one R AA is or comprises an electron- withdrawing group from the list of EWG2 defined herein. In some embodiments, at least one R AA is or comprises an electron- withdrawing group from the list of EWG3 defined herein. In some embodiments, at least one R AA is or comprises an electron- withdrawing group from the list of EWG4 defined herein. In some embodiments, at least one RAA is or comprises an electron-withdrawing group from the list of Pi-EWGs defined herein.

[0191] In some embodiments, at least one R BB is or comprises an electron-withdrawing group from the list of EWG1 defined herein. In some embodiments, at least one R BB is or comprises an electron-withdrawing group from the list of EWG2 defined herein. In some embodiments, at least one R BB is or comprises an electron-withdrawing group from the list of EWG3 defined herein. In some embodiments, at least one R BB is or comprises an electron-withdrawing group from the list of EWG4 defined herein. In some embodiments, at least one R BB is or comprises an electron-withdrawing group from the list of Pi-EWGs defined herein.

[0192] In some embodiments, R 3 is or comprises an electron-withdrawing group from the list of EWG1 defined herein. In some embodiments, R 3 is or comprises an electron-withdrawing group from the list of EWG2 defined herein. In some embodiments, R 3 is or comprises an electron-withdrawing group from the list of EWG3 defined herein. In some embodiments, R 3 is or comprises an electron-withdrawing group from the list of EWG4 defined herein. In some embodiments, R 3 is or comprises an electron-withdrawing group from the list of Pi-EWGs defined herein.

[0193] In some embodiments, R 4 is or comprises an electron-withdrawing group from the list of EWG1 defined herein. In some embodiments, R 4 is or comprises an electron-withdrawing group from the list of EWG2 defined herein. In some embodiments, R 4 is or comprises an electron-withdrawing group from the list of EWG3 defined herein. In some embodiments, R 4 is or comprises an electron-withdrawing group from the list of EWG4 defined herein. In some embodiments, R 4 is or comprises an electron-withdrawing group from the list of Pi-EWGs defined herein.

[0194] In some embodiments, the compound is selected from the group consisting of:

[0195]

[0196]

[0197] wherein any two substituents can be joined or fused to form a ring.

[0198] In some embodiments, the compound is selected from the group consisting of the following structures (List 1):

[0199]

[0200]

[0201]

[0202]

[0203]

[0204]

[0205]

[0206]

[0207]

[0208]

[0209]

[0210] In some embodiments, each moiety A can be independently 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.

[0211] In some embodiments, each moiety A can be independently a polycyclic fused ring structure. In some embodiments, each moiety A can be independently 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 moiety A can be independently selected from the group consisting of benzofuran, benzothiophene, benzoselenophene, naphthalene, and nitrogen hetero variants thereof.

[0212] In some embodiments, moiety A 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 coordinated to the metal M and the second 6-membered ring is fused to the 5-membered ring. In some embodiments, moiety A can independently be selected from the group consisting of dibenzofuran, dibenzothiophene, dibenzoselenophene, and nitrogen hetero variants thereof. In some such embodiments, moiety A 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 variant contains exactly one N atom at the 6 position (ortho to O, S, or Se) and a substituent at the 7 position (meta to O, S, or Se).

[0213] In some embodiments, moiety A 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.

[0214] In some embodiments, moiety A 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.

[0215] In some embodiments, moiety A can independently be a nitrogen hetero version of the polycyclic fused rings described above. In some such embodiments, moiety A can independently contain exactly one nitrogen hetero N atom. In some such embodiments, moiety A contains exactly two nitrogen hetero N atoms, which can be in one ring or in two different rings. In some such embodiments, the ring having the nitrogen hetero N atom is separated from the metal M atom by at least two other rings. In some such embodiments, the ring having the nitrogen hetero 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 nitrogen hetero N atom is substituted.

[0216] 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.

[0217] 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 invention 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 ligand coordinated to the metal can be 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.

[0218] In yet another aspect of the present disclosure, a formulation comprising the novel compounds 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.

[0219] 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, the present compound 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, the present compound 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.

[0220] C. OLEDs and devices of the present disclosure

[0221] 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.

[0222] 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 as described herein.

[0223] 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.

[0224] 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, oxa- borabenzene, dihydroacridine, xanthene, dihydrobenzazasilole, dibenzoxasilole, 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

[0225] In some embodiments, the main group can be selected from the group consisting of the structures in main group 1 below:

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236] wherein:

[0237] each of J1to J6is independently C or N;

[0238] L' is a direct bond or an organic linking group;

[0239] 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';

[0240] R A' , R B' , R C' , R D' , R E' , R F' , and R G' each independently represents mono-substitution, up to maximum substitution, or no substitution;

[0241] 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 general substituents as defined herein; any two substituents can be joined or fused to form a ring;

[0242] and, where possible, each unsubstituted aromatic carbon atom is optionally replaced with N to form a nitrogen hetero substituted ring.

[0243] 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.

[0244] 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:

[0245]

[0246]

[0247] The structures of MG1to MG27are shown below:

[0248]

[0249]

[0250] 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.

[0251] In some embodiments, the host can be any of its aza-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:

[0252]

[0253]

[0254] 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.

[0255] In some embodiments, the organic layer can further comprise a host, wherein the host comprises a metal complex.

[0256] 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).

[0257] 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.

[0258] 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. A fluorescent emitter can be a delayed fluorescent or non-delayed fluorescent emitter. Depending on the spin state, a 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. 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 TADF emission requires a compound or an excited state complex having a small singlet-triplet energy gap (ΔEST) 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 at 293 K is less than or equal to 10 microseconds. 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 at 293 K is less than or equal to 10 microseconds. In some embodiments, such time can be greater than 10 microseconds and less than 100 microseconds.

[0259] 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.

[0260] In some embodiments, the inventive compounds described herein are phosphorescent materials.

[0261] 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 within the OLED (e.g., a host material, an emitter material).

[0262] 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.

[0263] 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.

[0264] 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.

[0265] 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.

[0266] 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, light of the light blue and dark blue colors as described above. 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 on top of one another; and the second emissive region comprises (if more than one) a second number of emissive layers deposited on top of one another; 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, while 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.

[0267] 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.

[0268] 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 sensitizing device features and various embodiments of the inventive compounds disclosed herein. For example, the first emissive region is comprised in a sensitizing device, while the second emissive region is not comprised in a sensitizing device; in some cases, both the first emissive region and the second emissive region are comprised in a sensitizing device.

[0269] In some embodiments, the OLED can emit light from plasmonic modes having at least 1%, 5%, 10%, 30%, 50%, 70%, 80%, 90%, 95%, 99%, or 100% light intensity. In some embodiments, at least one of the anode, cathode, or a new layer disposed above the organic emitting layer serves as a reinforcement layer. The reinforcement layer comprises a plasmonic material exhibiting surface plasmon resonance, which is nonradiatively coupled to the emitter material and transfers excited-state energy from the emitter material to the nonradiative mode of the surface plasmon polaritons. In some embodiments, the reinforcement layer is positioned at a distance from the organic emitting layer not exceeding a threshold distance, wherein the emitter material has a total nonradiative decay rate constant and a total radiative decay rate constant due to the presence of the reinforcement layer. The threshold distance is the position where the total nonradiative decay rate constant equals the total radiative decay rate constant. Another threshold distance is the distance at which the total radiative decay rate constant divided by the sum of the total nonradiative decay rate constant and the total radiative decay rate constant equals the photoluminescence yield of the emitting material without the reinforcement layer.

[0270] In some embodiments, the OLED further includes an external coupling layer. In some embodiments, the external coupling layer is disposed above the enhancement layer on the side opposite the organic emitting layer. The external coupling layer scatters energy from surface plasmon polaritons. In some embodiments, this energy is scattered as photons into free space. In other embodiments, energy is scattered from the surface plasmon polariton 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 intermediary layers may be disposed between the enhancement layer and the external coupling layer. Examples of intermediary layers may be dielectric materials, including organic, inorganic, perovskite, and oxide materials, and may comprise stacks and / or mixtures of these materials.

[0271] The enhancement layer alters the effective properties of the medium in which the emitter material resides, thereby causing any or all of the following: reduced emissivity, altered emission profile, changes in emission intensity with angle, altered emitter material stability, altered OLED efficiency, and reduced roll-off efficiency of the OLED device. Placing the enhancement layer on the cathode side, anode side, or both sides, or placing the enhancement layer itself as a CGL, produces an OLED device that utilizes any of the aforementioned effects. In addition to the specific functional layers mentioned herein and illustrated in the various OLED examples shown in the figures, the OLED according to this disclosure may also include any other functional layers commonly found in OLEDs.

[0272] 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.

[0273] 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.

[0274] 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.

[0275] 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.

[0276] 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.

[0277] 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 anode and cathode, holes are injected from the anode through the organic layer(s) and electrons are injected from the cathode through the organic layer(s). The injected holes and electrons each migrate toward the oppositely charged electrode. When an electron and hole localize on the same molecule, an "exciton," which is a localized electron-hole pair having an excited energy state, is formed. When the exciton relaxes through a photoemissive mechanism, light is emitted. 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.

[0278] 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.

[0279] 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) with an overlying 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.

[0280] 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 the anode, and device 200 has a cathode 215 disposed under the 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.

[0281] Figure 1 and 2The simple layered structures described herein are provided by way of non-limiting examples, and it should be understood that embodiments of this disclosure can be used in conjunction with a variety of other structures. The specific 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 based on design, performance, and cost factors. Other layers not specifically described may also be included. Materials other than those specifically described may be used. Although many examples provided herein describe various layers as comprising a single material, it should be understood that combinations of materials, such as mixtures of host and dopant, or more generally, mixtures, can be used. Furthermore, the layers may have various sublayers. The names given to the various layers herein are not intended to be strictly limiting. For example, in device 200, hole transport layer 225 transports holes and injects holes into emitter layer 220, and can be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED may be described as having an “organic layer” disposed between a cathode and an anode. This organic layer may comprise a single layer, or may further comprise, for example, regarding Figure 1 and 2 Multiple layers of the different organic materials mentioned above.

[0282] Structures and materials not specifically described can also be used, such as OLEDs (PLEDs) containing polymeric materials, as disclosed in, for example, U.S. Patent No. 5,247,190 to Friend et al., which is incorporated herein by reference in its entirety. By another example, OLEDs with a single organic layer can be used. OLEDs can be stacked, for example, as described in, U.S. Patent No. 5,707,745 to Forrest et al., which is incorporated herein by reference in its entirety. OLED structures can be deviated from... Figure 1 and 2 The simple layered structure described herein. For example, the substrate may include angled reflective surfaces to improve out-coupling, such as the tabletop structure described in U.S. Patent No. 6,091,195 to Forrest et al., and / or the recessed structure described in U.S. Patent No. 5,834,893 to Bulovic et al., which are incorporated herein by reference in their entirety.

[0283] 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 Fogarty, et al., 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 are incorporated by reference in their entireties. Other suitable deposition methods include spin coating and other solution based processes. Solution based processes are preferably conducted in nitrogen or inert atmospheres. 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, for solution processes, the materials can be modified in order to make them compatible with the solvent used for the process. For example, 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 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 a lower tendency to recrystallize. Dendrimer substituents can be used to enhance the solution processability of small molecules.

[0284] 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 on the substrate, electrode(s), or both, and can be deposited between some or all of the electrodes. A barrier layer can be deposited on the entire surface of the device, or only on portions of the surface. A barrier layer can be deposited all around the perimeter of the device, or only on a partial perimeter. The barrier layer can be deposited on the substrate, on the electrode(s), or on both the substrate and the electrode(s). A barrier layer can be deposited on any other portion of the device including the edges. The barrier layer can be deposited using any appropriate technique. For example, the deposition can be accomplished using chemical vapor deposition, thermal evaporation, sputtering, and / or physical vapor deposition, among other techniques. The deposition can be accomplished using any appropriate material or combination of materials. The barrier layer can comprise a single layer or multiple layers. The barrier layer can be formed of inorganic compounds or organic compounds, or both. Preferred barrier layers comprise 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.

[0285] 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).

[0286] 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.

[0287] 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.

[0288] 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.

[0289] 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.

[0290] Other materials used in OLEDs

[0291] 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 that are present in devices. For example, the emissive dopants disclosed herein can be used by themselves as the emissive dopant in an 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.

[0292] a) Conductive dopants:

[0293] 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.

[0294] b) HIL / HTL:

[0295] The hole injection / transport material used in the present disclosure is not particularly limited, and any compound can be used as long as the compound is generally used as a hole injection / transport material. Examples of the material include, but are not limited to, phthalocyanine or porphyrin derivatives; aromatic amine derivatives; indolocarbazole derivatives; fluorocarbon-containing polymers; polymers with conductive dopants; conductive polymers such as PEDOT / PSS; self-assembled monomers derived from compounds such as phosphonic acid and silane derivatives; metal oxide derivatives such as MoO x ; p-type semiconductive organic compounds such as 1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile; metal complexes; and cross-linkable compounds.

[0296] Examples of the aromatic amine derivative used for the HIL or HTL include, but are not limited to, the following general structures:

[0297]

[0298] Ar 1 to Ar 9 each of which is selected from the group consisting of aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, terphenyl, triphenylene, naphthalene, anthracene, azulene, phenanthrene, fluorene, pyrene, perylene, and azulene; aromatic heterocyclic compounds such as dithiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolo-dipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indooxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthpyridine, phtalazine, pteridine, xanthene, acridine, phenoxazine, phenothiazine, phenoxazine, benzofuropyridine, furopyridine, benzothiophenopyridine, thienopyridine, benzoselenophenopyridine, and selenophenopyridine; and a group consisting of 2 to 10 cyclic structural units which are groups of the same type or different types selected from aromatic hydrocarbon ring groups and aromatic heterocyclic ring groups and are bonded to each other directly or via at least one of oxygen atoms, nitrogen atoms, sulfur atoms, silicon atoms, phosphorus atoms, boron atoms, chain structural units, and aliphatic ring groups. Ar 1 to Ar 9 Each of Ar

[0299] In some embodiments, each Ar 1 to Ar 9 independently comprises a moiety selected from the group consisting of

[0300]

[0301] 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.

[0302] Examples of metal complexes used in the HIL or HTL include, but are not limited to, the following general formula:

[0303]

[0304] 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.

[0305] 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.

[0306] 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 polymers based on polythiophene, triarylamines, triarylamine containing spirofluorene core, arylamine carbazole compounds, triarylamine containing (di)benzothiophene / (di)benzofuran, indolocarbazole, isoindole compounds, and metal carbene complexes.

[0307] c) EBL:

[0308] An electron blocking layer (EBL) can be used to reduce the number of electrons and / or excitons leaving the emissive layer. The presence of such a blocking layer in a device can result in a device that has a generally higher efficiency and / or a longer lifetime compared to a similar device lacking the blocking layer. Further, the blocking layer can be used to confine the emission to a desired area of the OLED. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or a higher triplet energy than the one or more emitters closest to the EBL interface. In some embodiments, the compound used in the EBL contains at least one carbazole group and / or at least one arylamine group. In some embodiments, the compound used in the EBL has a HOMO energy level shallower 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.

[0309] d) Host:

[0310] 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.

[0311] Examples of the metal complex used as the host preferably have the following general formula:

[0312]

[0313] wherein Met is a metal; (Y 103 -Y 104 ) is a bidentate ligand, Y 103 and Y 104 the coordinating 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.

[0314] In some embodiments, the metal complex is:

[0315]

[0316] wherein (O-N) is a bidentate ligand having a metal coordinated to O and N atoms.

[0317] In some embodiments, Met is selected from Ir and Pt. In another embodiment, (Y 103 -Y 104 ) is a carbene ligand.

[0318] In some embodiments, the host compound contains at least one from the following groups selected from the group consisting of aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, rea, phenanthrene, fluorene, pyrene, 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, phtalazine, pteridine, xanthene, acridine, phenoxazine, phenothiazine, phenoxazine, azadibenzothiophene, azadibenzofuran, azadibenzoselenophene, azacarbazole, azaindolocarbazole, azatriphenylene, azatetraphenylene, 5λ 2 benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, 5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene; and the group consisting of 2 to 10 cyclic structural units which are groups of the same type or different types selected from aromatic hydrocarbon ring groups and aromatic heterocyclic ring groups and are bonded to each other directly or via at least one of oxygen atoms, nitrogen atoms, sulfur atoms, silicon atoms, phosphorus atoms, boron atoms, chain structural units, and aliphatic ring groups. Each option within each group can be unsubstituted or can be substituted with the general substituents as described herein or can be further fused.

[0319] In some embodiments, the host compound comprises at least one from the group consisting of moieties selected from the group consisting of:

[0320]

[0321] wherein k is an integer from 0 to 20 or 1 to 20. X 101 to X 108 is independently selected from C or N. Z 101 and Z 102 is independently selected from C, N, O, or S.

[0322] In some embodiments, the host material is selected from the group consisting of arylcarbazoles, metal 8-hydroxyquinolinate (e.g., alq3, balq), metal phenoxybenzothiazole compounds, conjugated oligomers and polymers (e.g., polyfluorenes), aromatic fused rings, zinc complexes, 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).

[0323] e) Emitter materials in the EML:

[0324] 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.

[0325] In some embodiments, the emitter material has the formula M(L 1 ) x (L 2 ) y (L 3 ) z ;

[0326] wherein L 1 , L 2 , and L 3 may be the same or different;

[0327] wherein x is 1, 2, or 3;

[0328] wherein y is 0, 1, or 2;

[0329] wherein z is 0, 1, or 2;

[0330] wherein x + y + z is the oxidation state of the metal M;

[0331] wherein L 1 is selected from the group consisting of the structures in the following list of ligands:

[0332]

[0333]

[0334]

[0335] wherein each L 2 and L 3 is independently selected from the group consisting of and the list of ligands; wherein:

[0336] M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Pd, Zn, Au, Ag, and Cu;

[0337] T is selected from the group consisting of B, Al, Ga, and In;

[0338] K 1' is a direct bond or selected from the group consisting of NR e , PR e , O, S, and Se;

[0339] each Y 1 to Y 15 is independently selected from the group consisting of carbon and nitrogen;

[0340] 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 ;

[0341] 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;

[0342] 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 general substituents as defined herein; and

[0343] Any two substituents can be fused or joined to form a ring or to form a polydentate ligand.

[0344] In some embodiments, the emitter material is selected from the group consisting of the following dopant Group 1:

[0345]

[0346]

[0347]

[0348]

[0349]

[0350]

[0351] wherein

[0352] X 96 each of X 99 is independently C or N;

[0353] each Y 100 is independently selected from the group consisting of NR", O, S, and Se;

[0354] each of R 10a , R 20a , R 30a , R 40a , and R 50a independently represents mono-substitution, up to maximum substitution, or no substitution;

[0355] 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 is independently hydrogen or a substituent selected from the group consisting of the generic substituents defined herein; any two substituents can be joined or fused to form a ring.

[0356] In some embodiments, the emitter material is selected from the group consisting of the following dopant Group 2:

[0357]

[0358]

[0359]

[0360]

[0361]

[0362]

[0363]

[0364]

[0365] wherein:

[0366] each Y 100 is independently selected from the group consisting of NR", O, S, and Se;

[0367] L is independently selected from the group consisting of a direct bond, BR", BR"R"', NR", PR", O, S, Se, C=0, C=S, C=Se, C=NR", C=CR"R"', S=0, S02, CR", CR"R"', SiR"R"', GeR"R"', alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof;

[0368] X 100 and X 200 is selected from the group consisting of O, S, Se, NR", and CR"R"' at each occurrence;

[0369] 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;

[0370] 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; and any two substituents can be joined or fused to form a ring.

[0371] 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.

[0372] 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.

[0373] 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:

[0374]

[0375]

[0376] wherein A 1 -A 9 are each independently selected from C or N;

[0377] each R P , R Q , and R U independently represents mono-substitution, up to maximum substitution, or no substitution;

[0378] 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; and any two substituents can be joined or fused to form a ring.

[0379] In some embodiments of the OLED, the delayed fluorescence material comprises at least one of the donor moieties selected from the group consisting of:

[0380]

[0381] 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.

[0382] 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 with N.

[0383] 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, aza-carbazole, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene, aza-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).

[0384] In some embodiments, the fluorescent material comprises at least one of the chemical moieties selected from the group consisting of:

[0385]

[0386]

[0387]

[0388] 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;

[0389] wherein X F and X G are each independently selected from the group consisting of C and N.

[0390] In some of the above embodiments, any of the carbocyclic atoms in each of the phenyl rings up to a total of at most three carbocyclic atoms together with its substituents can be replaced by N.

[0391] f) HBL:

[0392] A hole blocking layer (HBL) can be used to reduce the number of holes and / or excitons that escape from 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 the 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.

[0393] In some embodiments, the compounds used in the HBL contain the same molecule or the same functional group as used by the host described above.

[0394] In some embodiments, the compounds used in the HBL comprise at least one of the following moieties selected from the group consisting of:

[0395]

[0396] where k is an integer from 1 to 20; L 101 is another ligand, k' is an integer from 1 to 3.

[0397] g) ETL:

[0398] 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.

[0399] In some embodiments, the compounds used in the ETL comprise at least one of the following moieties in the molecule:

[0400] and fullerene; where 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.

[0401] In some embodiments, the metal complex used in the ETL contains, but is not limited to, the following general formula:

[0402]

[0403] where (O-N) or (N-N) is a bidentate ligand having a metal coordinated to atoms O, N or N, N; 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.

[0404] 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.

[0405] h) Charge Generation Layer (CGL)

[0406] 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 electrons and holes consumed in the CGL are refilled by the 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.

[0407] 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.

[0408] It should be understood that the various embodiments described herein are by way of example only, and are not intended to limit the scope of the invention. For example, many of the materials and structures described herein can be substituted with other materials and structures without deviating from the spirit of the invention. The claimed invention may, therefore, include variations to the specific examples and preferred embodiments described herein, as will be apparent to one of skill in the art. It is to be understood that the various theories regarding why the invention works are not intended to be limiting.

[0409] Experimental Data

[0410] Synthesis of compound 1 of the invention

[0411]

[0412] Step 1 : Synthesis of 3-bromo-N-(2,6-diisopropylphenyl)-2-nitroaniline

[0413]

[0414] To a stirred solution of 1-bromo-3-fluoro-2-nitrobenzene 1 (10.0 g, 1.0 eq, 45.5 mmol) in tetrahydrofuran (100.0 mL) was added 2,6-diisopropylaniline 2 (8.87 g, 9.4 mL, 1.1 eq, 50.0 mmol) and 1 M LiHMDS (11.4 g, 68.2 mL, 1.00 mole, 1.5 eq, 68.2 mmol) in THF at -78 °C. The reaction mixture was allowed to warm to room temperature and then stirred under N2atmosphere for 1 h.

[0415] The reaction mixture was quenched with saturated aqueous ammonium chloride solution (250 mL) and then extracted with EtOAc (2 x 250 mL). The combined organic phase was washed with brine and then dried over magnesium sulfate, followed by filtration and concentration to dryness to give the crude product as an orange oil.

[0416] The crude material was purified by trituration with heptane to give the product 3 (12.3 g, 32.60 mmol, 71.7% yield) as an orange solid. The product was used in the next step without further purification.

[0417] 1 H-NMR (396 MHz, Chloroform-D) δ 7.40 - 7.36 (m, 1H), 7.28 (d, J = 3.6 Hz, 2H), 7.15 (s, 1H), 7.02 - 6.98 (m, 2H), 6.30 (td, J = 7.0, 3.6 Hz, 1H), 3.11 - 3.00 (m, 2H), 1.19 (d, J = 6.7 Hz, 6H), 1.15 (d, J = 7.3 Hz, 6H).

[0418] Step 2: Synthesis of 3-bromo-N1-(2,6-diisopropylphenyl)benzene-1,2-diamine

[0419]

[0420] To a stirred suspension of 3-bromo-N-(2,6-diisopropylphenyl)-2-nitroaniline 3 (12.2 g, 1.0 equiv, 32.3 mmol) in acetic acid (100.0 mL) was added zinc (21.1 g, 10.0 equiv, 323.4 mmol) and the reaction mixture was stirred at room temperature for 0.5 h.

[0421] The reaction mixture was filtered through a plug of celite and washed with EtOAc (100 mL). The filtrate was concentrated to dryness to give the product 4 as a brown gum (9.45 g, 27.30 mmol, 84.4% yield). The product was used in the next step without further purification.

[0422] 1 H-NMR (396 MHz, chloroform-D) δ 7.24-7.13 (m, 3H), 6.99-6.89 (m, 1H), 6.56-6.51 (m, 1H), 6.11-6.11 (m, 1H), 3.04-3.00 (m, 2H), 1.15-1.10 (m, 12H). No exchangeable protons were observed.

[0423] Step 3: Synthesis of 4-bromo-1-(2,6-diisopropylphenyl)-2-phenyl-1H- benzo[d]imidazole

[0424]

[0425] To a stirred suspension of 3-bromo-N1-(2,6-diisopropylphenyl)benzene-1,2- diamine 4 (4.44 g, 1.0 equiv, 12.8 mmol) in EtOH (IMS) (50.0 mL) was added benzaldehyde 5 (1.63 g, 1.56 mL, 1.2 equiv, 15.3 mmol) and sodium metabisulfite (12.2 g, 5.0 equiv, 63.9 mmol) and the reaction mixture was stirred at 85 °C for 18 h under open air.

[0426] The reaction mixture was cooled to room temperature and water (50 mL) was added. The mixture was extracted with EtOAc (2 x 50 mL) and the organic phase was washed with brine (50 mL) and dried over anhydrous sodium sulfate, then filtered and concentrated to dryness. The crude material was obtained as a dark brown gum.

[0427] The crude material was purified by normal phase column chromatography (Isolera by Biotage, 80 g Silicycle cartridge, 0% - 10% EtOAc in heptane, 10 CVs) to give the product 6 as a brown solid (4.77 g, 11.0 mmol, 86.4% yield).

[0428] 1H-NMR (396 MHz, DMSO-D6) δ 7.61 (t, J = 7.9 Hz, 1H), 7.56-7.51 (m, 3H), 7.44 (d, J = 7.9 Hz, 2H), 7.40-7.33 (m, 3H), 7.18-7.14 (m, 1H), 6.89 (d, J = 8.5 Hz, 1H), 2.15-2.05 (m, 2H), 0.90 (d, J = 6.7 Hz, 6H), 0.79 (d, J = 7.3 Hz, 6H).

[0429] Step 4: Synthesis of 1-(2,6-diisopropylphenyl)-2-phenyl-4-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)-1H-benzo[d]imidazole

[0430]

[0431] To a solution of 4-bromo-1-(2,6-diisopropylphenyl)-2-phenyl-1H-benzo[d]imidazole 6 (4.50 g, 1 equiv, 10.4 mmol) in 1,4-dioxane (50.0 mL) was added bis(pinacolato)diboron (3.16 g, 1.2 equiv, 12.5 mmol), PdCl2(dppf)-CH2Cl2 adduct (339 mg, 0.04 equiv, 415 μmol) and potassium acetate (2.04 g, 2 equiv, 20.8 mmol) and the mixture was degassed for 10 min. The reaction mixture was stirred at 100 °C under nitrogen flow for 2 h.

[0432] The reaction mixture was cooled to room temperature and then passed through a pad of celite, which was washed with DCM until the dark color disappeared. The filtrate was concentrated to dryness to give the crude material as a dark brown oil.

[0433] The crude material was purified by normal phase column chromatography (Isolera by Biotage, 220 g Silicycle cartridge, 0% - 20% EtOAc in heptane, 10 CV in) to give the product 7 (3.25 g, 6.77 mmol, 65.2% yield) as a white solid.

[0434] The obtained 1 H-NMR indicated the presence of excess bis(pinacolato)diboron (NMR untreated). The product was used in the next step without further purification.

[0435] Step 5: Synthesis of 2-(4-bromo-1-(2,6-diisopropylphenyl)-1H-benzo[d]imidazol-2-yl)phenol

[0436]

[0437] To a stirred solution of 3-bromo-N1-(2,6-diisopropylphenyl)benzene-1,2-diamine 4 (5.00 g, 1 equiv, 14.4 mmol) in EtOH (IMS) (50.0 mL) was added 2-hydroxybenzaldehyde 8 (2.11 g, 1.80 mL, 1.2 equiv, 17.3 mmol) and sodium metabisulfite (13.7 g, 5.0 equiv, 72.0 mmol) and the reaction mixture was stirred at 85 °C for 6 h under open air.

[0438] The reaction mixture was cooled to room temperature and water (100 mL) was added. The mixture was extracted with EtOAc (2 x 100 mL) and the organic phase was washed with brine (100 mL) and dried over anhydrous sodium sulfate, then filtered and concentrated to dryness. The crude material was obtained as a dark brown gum.

[0439] The crude material was purified by normal phase column chromatography (Isolera, Biotage, 80 g Silicycle cartridge, 0-10% EtOAc in heptane, 10 CVs) to give the product 9 (4.80 g, 11.0 mmol, 86.4% yield) as a brown solid.

[0440] 1 H-NMR (396 MHz, DMSO-D6) δ 13.61 (s, 1H), 7.72 (t, J = 7.6 Hz, 1H), 7.65 (d, J = 7.9 Hz, 1H), 7.55 (d, J = 7.9 Hz, 2H), 7.35-7.25 (m, 2H), 7.06 (dd, J = 8.5, 1.2 Hz, 1H), 6.96 (d, J = 8.5 Hz, 1H), 6.75 (dd, J = 8.2, 1.5 Hz, 1H), 6.62-6.58 (m, 1H), 2.15-2.11 (m, 2H), 0.94 (d, J = 6.7 Hz, 6H), 0.87 (d, J = 7.3 Hz, 6H).

[0441] Step 6: Synthesis of 2-(1,1'-bis(2,6-diisopropylphenyl)-2'-phenyl-1H,1'H- [4,4'-bibenzo[d]imidazol]-2-yl)phenol

[0442]

[0443] To a solution of 2-(4-bromo-l-(2,6-diisopropylphenyl)-lH-benzo[d]imidazol-2- yl)phenol 9 (2.34 g, 1.0 equiv, 5.21 mmol) and l-(2,6-diisopropylphenyl)-2-phenyl-4- (4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)-lH-benzo[d]imidazole 7 (2.75 g, 1.1 equiv, 5.73 mmol) in 1,4-dioxane (50.0 mL) and water (10.0 mL) was added cesium carbonate (5.09 g, 3.0 equiv, 15.6 mmol) and XPhos Pd G2 (205 mg, 0.05 equiv, 260 μmol). The reaction mixture was degassed and then stirred at 100 °C for 2 h.

[0444] The reaction mixture was cooled to room temperature and then quenched with saturated aqueous sodium bicarbonate solution (50 mL). The mixture was extracted with EtOAc (2 x 50 mL) and the organic layer was washed with brine (100 mL) and dried over anhydrous sodium sulfate, then filtered and concentrated to dryness. The crude material was obtained as a dark brown oil.

[0445] The crude material was purified by normal phase column chromatography (Isolera, 330 g Silicycle cartridge, 0% - 5% EtOAc in heptane, 10 CV) to give a purple solid.

[0446] The purple solid was triturated with decanted acetonitrile (20 mL) and the solid was washed with acetonitrile (2 x 10 mL) to give an off-white solid.

[0447] The off-white solid was recrystallized by dissolving in DCM (10 mL) and then slowly adding acetonitrile (50 mL) to give two batches of 0.770 g and 2.54 g (63% overall yield) of the product as white crystals.

[0448] 1H-NMR (396 MHz, DMSO-D6) δ 14.17 (s, 1H), 8.38 (d, J = 6.7 Hz, 1H), 8.11 (d, J = 6.7 Hz, 1H), 7.75 (t, J = 7.9 Hz, 1H), 7.67 (t, J = 7.9 Hz, 1H), 7.61 - 7.46 (m, 8H), 7.40 - 7.26 (m, 4H), 7.02 - 6.93 (m, 3H), 6.78 (dd, J = 7.9, 1.2 Hz, 1H), 6.60 - 6.56 (m, 1H), 2.32 - 2.22 (m, 4H), 1.04 (d, J = 6.3 Hz, 6H), 1.02 (d, J = 6.7 Hz, 6H), 0.91 (d, J = 7.3 Hz, 6H), 0.87 (d, J = 6.7 Hz, 6H)

[0449] 1 H-NMR (396 MHz, DMSO-D6) δ 14.17 (s, 1H), 8.38 (d, J = 6.7 Hz, 1H), 8.11 (d, J = 6.7 Hz, 1H), 7.75 (t, J = 7.9 Hz, 1H), 7.67 (t, J = 7.9 Hz, 1H), 7.61 - 7.46 (m, 8H), 7.40 - 7.26 (m, 4H), 7.02 - 6.93 (m, 3H), 6.78 (dd, J = 7.9, 1.2 Hz, 1H), 6.60 - 6.56 (m, 1H), 2.32 - 2.22 (m, 4H), 1.04 (d, J = 6.3 Hz, 6H), 1.02 (d, J = 6.7 Hz, 6H), 0.91 (d, J = 7.3 Hz, 6H), 0.87 (d, J = 6.7 Hz, 6H)

[0450] Step 7: Synthesis of compound 1 of the present invention

[0451]

[0452] Into a 250 ml RBF was charged with 2-(1,1'-bis(2,6-diisopropylphenyl)-2'-phenyl-1H,1'H- [4,4'-bi-1H-benzo[d]imidazol]-2-yl)phenol (1.500 g, 1 eq, 2.075 mmol), Pt(ACAC)2 (816.0 mg, 1 eq, 2.075 mmol), acetic acid (42.00 mL). The reaction mixture was heated to reflux for 72 hours. The solvent was removed, and the residue was column chromatographed to give the desired product. (1.16 g, 61%)

[0453] Synthesis of compound 2 of the present invention

[0454]

[0455] Step 1

[0456] A solution of 4,5-bis(methyl-d3)-2-phenylpyridine (5.0 g, 1 eq, 26.41 mmol) in dichloromethane (180 mL) was cooled to 0 °C with an ice / water bath. 3-Chloroperbenzoic acid (9.12 g, 70 Wt%, 1.4 eq, 36.98 mmol) was added portionwise. The reaction mixture was stirred at 0 °C for 30 min, then allowed to warm to room temperature and stirred for 16 hours.

[0457] The reaction mixture was cooled to 0 °C and 1 M NaOH (100 mL) was added, and the mixture was stirred for 15 min. The layers were separated, and the organic phase was washed with 1 M NaOH (100 mL). The combined aqueous solutions were washed with DCM (2 x 50 mL). The combined organics were washed with brine (100 mL), dried over MgS04and the solvent was removed in vacuo to give the product as a white solid. (5.2 g, 96%).

[0458] 1 H-NMR (396 MHz, CDC13) δ 8.18 (s, 1H), 7.81-7.78 (m, 2H), 7.49-7.40 (m, 3H), 7.19 (s, 1H) ppm.

[0459] Step 2

[0460] 4,5-bis(methyl-d3)-2-phenylpyridine 1-oxide (2.0 g, 1 eq, 9.742 mmol) was dissolved in anhydrous N,N-dimethylformamide (80 mL). The solution was cooled to 0 °C under N2and phosphorous oxybromide (5.59 g, 2 eq, 19.48 mmol) was added portionwise. The reaction was stirred at 0 °C for 3 hours, after which it was carefully quenched with H20 (100 mL). The resulting precipitate was filtered, washed with water and air dried to give the product as a white solid. (1.10 g, 42%).

[0461] UPLC-MS (acidic, 4.5 min, 5% to 95%): Rt = 3.15 min (92.8%), MS (ESI pos): m / z = [M+H]+268.0 / 270.0

[0462] Step 3

[0463] A three necked 500 mL RBF, equipped with a thermometer and a dropping funnel, was charged with 1-bromo-3-fluoro-2-nitrobenzene (10.0 g, 1 eq, 45.45 mmol) in THF (100 mL) and placed under nitrogen. 2,6-Diisopropylaniline (9.4 mL, 1.1 eq, 50.00 mmol) was added via syringe and the mixture was cooled in an ice bath [3°C internal temperature].

[0464] A 1 M solution of LiHMDS in THF (68 mL, 1.5 eq, 68.18 mmol) was added dropwise from the dropping funnel over 20 minutes, then the reaction mixture was stirred for a further 30 minutes.

[0465] The reaction mixture was quenched with saturated aqueous ammonium chloride solution (250 mL) and then the product was extracted with EtOAc (3 x 150 mL). The combined organic phases were washed with aqueous NH4CI solution (100 mL) and brine (250 mL) and dried over MgS04, then filtered and concentrated to dryness to give a dark orange / brown oil.

[0466] The oil was dissolved in acetonitrile (20-30 mL) then partially evaporated under reduced pressure until crystalline material began to form. The flask was stored at 5°C overnight.

[0467] The solid was collected by filtration and washed with a small amount of acetonitrile (2 x 10 mL) to give the product as a bright orange solid (7.947 g, 46%).

[0468] UPLC (BEH_C18_basic_5to95_long) Rt 3.73 min, m / z 375.0 / 377.1 [M-H] - (Bromine pattern), 98% purity

[0469] 1 H-NMR (396 MHz, Chloroform-D) δ 7.33 (q, J = 8.1 Hz, 1H), 7.24 (s, 1H), 7.23 (s, 1H), 7.12 (br s, 1H, can be NH exchangeable), 6.97 (dd, J = 7.0, 2.7 Hz, 2H), 6.28 - 6.24 (m, 1H), 3.05 - 2.98 (m, 2H), 1.15 (d, J = 7.3 Hz, 6H), 1.11 (d, J = 7.3 Hz, 6H) ppm

[0470] Step 4

[0471] A solution of 3-bromo-N-(2,6-diisopropylphenyl)-2-nitroaniline (6.94 g, 1 eq, 18.39 mmol) in acetic acid (55 mL) was cooled in an ice bath. Zinc (powder) (12 g, 10 eq, 183.9 mmol) was added portionwise over 5-10 minutes and the mixture was stirred (temperature of approximately 15 °C) for 1 hour.

[0472] EtOAc (50 mL) and celite (30 g) were added and the mixture was filtered over a pad of celite. The filtrate was evaporated under reduced pressure and the resulting oil was dissolved in EtOAc (200 mL) and washed with aqueous NaHC03solution (100 mL) and diluted ammonia / saline solution (100 mL). The organic layer was dried over MgS04, filtered and concentrated under reduced pressure to give the product as an orange / brown oil (6.63 g, 19.08 mmol, 104% - by 1 H NMR confirmed to contain EtOAc).

[0473] UPLC3 (PM_BEH_C18_long_basic_5to95) Rt 3.15 min, m / z 346.9 / 349.0 [M+H] + , 79% purity

[0474] 1 H-NMR (396 MHz, chloroform-D) δ 7.31 - 7.23 (m, 3H), 6.99 (dd, J = 7.9, 1.2 Hz, 1H), 6.53 (t, J = 7.9 Hz, 1H), 6.14 (dd, J = 7.9, 1.2 Hz, 1H), 4.68 - 5.19 (1H, NH), 3.08 - 3.01 (m, 2H), 1.21 - 1.08 (m, 12H) ppm

[0475] Step 5

[0476] To a stirred solution of 3-bromo-N1-(2,6-diisopropylphenyl)benzene-1,2-diamine (5.0 g, 1 eq, 14.40 mmol) in IMS (50 mL) was added 2-methoxybenzaldehyde (2.35 g, 2.087 mL, 1.2 eq, 17.28 mmol) and sodium metabisulfite (13.68 g, 5 eq, 71.98 mmol) and the reaction mixture was stirred at 85 °C under open air.

[0477] The reaction mixture was allowed to cool to room temperature. Water (50 mL) was added to the reaction mixture and then the product was extracted with EtOA (2 x 50 mL). The combined organic phase was washed with brine (100 mL) and then dried over anhydrous Na2S04, followed by filtration and concentration to dryness to give a brown gum.

[0478] The crude material was purified by normal phase column chromatography (Isolera, Siliasep 220g cartridge, 0% - 50% EtOAc, heptane, 10 CV) to give the product as a light brown solid (4.20 g, 63%).

[0479] UPLC1-MS (CSH-C18, short, acidic, 4.5 min, 5% to 95%): Rt = 3.48 min, m / z = 463.1 [M+H] + , 85% purity

[0480] 1 H-NMR (396 MHz, DMSO-D6) δ 7.53 (d, J = 7.9 Hz, 1H), 7.46 - 7.38 (m, 2H), 7.30 (d, J = 7.9 Hz, 2H), 7.17 (t, J = 7.9 Hz, 1H), 7.09 (dd, J = 7.6, 1.5 Hz, 2H), 6.90 (dd, J = 16.7, 7.6 Hz, 2H), 3.70 (s, 3H), 2.35 - 2.28 (m, 2H), 1.00 (d, J = 6.7 Hz, 6H), 0.89 (d, J = 6.7 Hz, 6H) ppm

[0481] Step 6

[0482] To a solution of 4-bromo-l-(2,6-diisopropylphenyl)-2-(2-methoxyphenyl)-lH- benzo[d]imidazole (6.45 g, 1 eq, 13.92 mmol) in 1,4-dioxane (70 mL) was added bis(pinacolato)diboron (5.30 g, 1.5 eq, 20.88 mmol) and potassium acetate (2.73 g, 2 eq, 27.84 mmol) under N2. The solution was bubbled with N2for 20 min, then PdCl2(dppf)CH2Cl2(568 mg, 0.05 eq, 695.9 μmol) was added. The reaction mixture was stirred at 100 °C for 16 hours.

[0483] The reaction mixture was allowed to cool to room temperature and filtered through a pad of celite washed with EtOAc. The solvent was removed under vacuum to give a brown solid. The solid was suspended in MeOH (50 mL) and sonicated for 30 min, the solid was filtered and washed again with MeOH to give the product as an off-white solid (5.54 g, 78%).

[0484] UPLC-MS (CSH-C18, Acidic, 4.5 min, 5-95): Rt = 1.97 min (47.9%), MS (ESI pos): m / z = [M+H]+ 429.3

[0485] 1 H NMR (396 MHz, DMSO-d6): δ ppm 7.61 (dd, J = 7.3, 1.2 Hz, 1 H), 7.32 - 7.42 (m, 2 H), 7.24 (d, J = 7.9 Hz, 2 H), 7.18 (t, J = 7.6 Hz, 1 H), 7.01 - 7.11 (m, 2 H), 6.92 - 6.97 (m, 1 H), 6.87 (t, J = 7.6 Hz, 1 H), 3.66 (s, 3 H), 2.23 - 2.38 (m, 2 H), 1.31 (s, 12 H), 0.98 (d, J = 6.7 Hz, 6 H), 0.83 (d, J = 6.7 Hz, 6 H) ppm.

[0486] Step 7

[0487] A multi-necked RBF was charged with 2-bromo-3,4-bis(methyl-d3)-6-phenylpyridine (0.955 g, 1 eq, 3.56 mmol), 1-(2,6-diisopropylphenyl)-2-(2-methoxyphenyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1 H- benzo[d]imidazole (2.00 g, 1.1 eq, 3.92 mmol), trimethyl(oxo)silane potassium (KOTMS, 558 mg, 90 Wt%, 1.1 eq, 3.92 mmol). The flask was backfilled with N2three times. THF (20 mL) was added and the solution was bubbled with N2for 15 min. XPhos PdG2 (140 mg, 0.05 eq, 178 pmol) was added and the reaction mixture was stirred at 60 °C for 3 hours.

[0488] The reaction was allowed to cool to room temperature, then diluted with EtOAc (20 mL) and filtered through a pad of celite, and washed further with EtOAc. The filtrate was concentrated in vacuo, then the residue was purified by normal phase chromatography (Isolera, 80 g SiliaSep cartridge; eluting with 0-60% EtOAc in heptane over 10 CV) to give the product as a white solid (1.71 g, 84%).

[0489] UPLC-MS (CSH-C18, Acidic, 4.5 min, 5-95): Rt = 3.83 min (91%), no ionisation t

[0490] ​1 1H-NMR (396MHz, CDCl3): δ 7.88–8.08 (m, 2H), 7.28–7.62 (m, 7H), 7.11–7.24 (m, 3H), 6.94–7.11 (m, 2H), 6.77–6.93 (m, 1H), 6.66–6.76 (m, 1H), 3.66–3.76 (m, 3H), 0.90–1.08 (m, 12H) ppm – Rotational isomers were observed.

[0491] Step 8

[0492] Compound 12 can be prepared by treating compound 11 with BBr3 (Bioorganic & Medicinal Chemistry (2012), 20(2), 949-961).

[0493] Step 9

[0494] Compound 2 of the present invention can be prepared by following the same procedure as compound 1 of the present invention.

[0495] Device Examples

[0496] Through high vacuum (<10) -7 The apparatus for manufacturing all examples is based on thermal evaporation. The anode is... Indium tin oxide (ITO). The cathode is made of... Liq (8-hydroxyquinoline lithium), and subsequently The device is composed of Al. All devices were immediately sealed in a nitrogen glove box (H2O and O2 < 1 ppm) with an epoxy-sealed glass lid, incorporating a desiccant into the packaging. The organic stack of the device examples consists of the following components sequentially from the ITO surface: HATCN is used as a hole injection layer (HIL); The HTM serves as the hole transport layer (HTL); thickness The emitter layer (EML) contains a 6:4 ratio of H-body (H1):E-body (H2) and 5% green emitter. The Liq (8-hydroxyquinoline lithium) is doped with 35% ETM as the ETL. The device structure is shown in Table 1. Table 1 shows the schematic device structure. The chemical structures of the device materials are shown below.

[0497]

[0498]

[0499] After manufacturing, it has reached DC 80mA / cm 2The EL, JVL, and lifetime of the lower measuring device were measured. Assuming an acceleration factor of 1.8, the LT97 at 9,000 nits was calculated from the 80 mA / cm2LT data. The device performance is shown in Table 2.

[0500] Table 1: Schematic device structure

[0501]

[0502] Table 2: Device performance

[0503]

[0504] The above data show that the present example exhibits green emission with a peak maximum at 542 nm; it is suitable for green OLED applications.

Claims

1. A compound comprising the structure of formula I: Where M is either Pt or Pd; Part A is a monocyclic or polycyclic fused ring system, wherein each ring in the monocyclic or polycyclic fused ring system is independently a 5- to 10-membered carbon ring or heterocyclic ring. wherein X 1 - X 8 each independently C or N; Z 1 and Z 2 each independently is C or N; wherein K 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 ); L is selected from the following groups: direct bond, O, S, Se, NR, BR, BRR', PR, CR. C=O, C=NR, C=CRR', C=S, CRR', SO, SO2, P(O)R, SiRR' and GeRR'; wherein R 1 is a substituted or unsubstituted carbocyclic or heterocyclic group; wherein R A , R B and R C each independently represent mono-substitution to the maximum allowable substitution or no substitution; wherein each R α , R β , R, R', R 2 , R A , R B , and R C 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; At least one of the following conditions is true: (1) at least one R A is R * wherein R * is a substituted carbocyclic or heterocyclic group, and R 1 and R * the total number of ring groups contained by R and R is three or more; (2) at least one R A a substituent other than hydrogen and bonded to a ring carbon atom contained in moiety A, with the proviso that the substituent is not 2,5-diisopropylphenyl; (3) L is CR, and R and R 2 bonded to form a benzene ring having at least one non-hydrogen substituent not included in ring D; (4) at least one R B is not hydrogen; and provided that two R A substituents or two R B substituents are not joined together to form a cyano-substituted benzofuran ring.

2. The compound of claim 1, wherein R α , R β , R, R', R 2 , R A , R B , and R C are each 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, sulfido, and combinations thereof; and / or wherein K is O; and / or wherein one of Z 1 and Z 2 is N.

3. The compound of claim 1, wherein at least one of X 1 -X 8 is N; and / or wherein all of X 1 -X 8 are C.

4. The compound of claim 1, wherein part A is independently selected from the group consisting of the following cyclic moieties: benzene, pyridine, pyrimidine, pyridazine, pyrazine, triazine, imidazole, imidazole-derived carbenes, pyrazole, pyrrole, oxazole, furan, thiophene, thiazole, triazole, naphthalene, quinoline, isoquinoline, quinazoline, benzofuran, aza-benzofuran, benzoxazole, aza-benzoxazole, benzothiophene, aza-benzothiophene, benzothiophene Azole, azir-benzothiazole, benzoselenene, azir-benzoselenene, indene, azir-indene, indole, azir-indole, benzimidazole, benzimidazole-derived carbenes, azir-benzimidazole-derived carbenes, azir-benzimidazole, carbazole, azir-carbazole, dibenzofuran, azir-dibenzofuran, dibenzothiophene, azir-dibenzothiophene, quinoxaline, phthalazine, phenanthrene, azir-phenanthrene, anthracene, azir-anthracene, phenanthridine, fluorene, and azir-fluorene.

5. The compound of claim 1, wherein R 1 comprises at least one 6-membered aromatic ring; and / or wherein R 1 comprises at least two alkyl groups.

6. The compound of claim 1, wherein R 2 is CRR'.

7. The compound of claim 1, wherein L is CR, and R and R 2 are joined to form a benzene ring having at least one non-hydrogen substituent not included in ring D.

8. The compound of claim 1, wherein the compound is selected from the group consisting of: in X 9 -X 18 each independently is C or N; Y B is selected from the group consisting of BR, BRR', NR, PR, P(O)R, O, S, Se, C=O, C=S, C=Se, C=NR', C=CRR', S=O, SO2, CR, CRR', SiRR' and GeRR'; L' is selected from the following groups: direct key, O, S, Se, NR, BR, BRR', PR, CR, C=O. C=NR, C=CRR', C=S, CRR', SO, SO2, P(O)R, SiRR' and GeRR'; R AA , R BB , and R D each independently represent mono-substitution to the maximum allowable substitution or no substitution; each R 3 , R 4 , R AA , R BB , and R D 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, and combinations thereof; and Any two substituents can join or fuse to form a ring.

9. The compound of claim 1, wherein the compound is selected from the group consisting of: Any two of the substituents can join or fused to form a ring.

10. The compound of claim 1, wherein the compound is selected from the group consisting of the structures listed in List 1.

11. An organic light-emitting device (OLED) comprising: anode; cathode; and An organic layer, disposed between the anode and the cathode, The organic layer comprises a compound having a structure of formula I: Where M is either Pt or Pd; Part A is a monocyclic or polycyclic fused ring system, wherein each ring in the monocyclic or polycyclic fused ring system is independently a 5- to 10-membered carbon ring or heterocyclic ring. wherein X 1 - X 8 each independently C or N; Z 1 and Z 2 each independently is C or N; wherein K 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 ); L is selected from the following groups: direct bond, O, S, Se, NR, BR, BRR', PR, CR. C=O, C=NR, C=CRR', C=S, CRR', SO, SO2, P(O)R, SiRR' and GeRR'; wherein R 1 is a substituted or unsubstituted carbocyclic or heterocyclic group; wherein R A , R B and R C each independently represent mono-substitution to the maximum allowable substitution or no substitution; wherein each R α , R β , R, R', R 2 , R A , R B , and R C 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 at least one of the following conditions is true: (1) at least one R A is R * wherein R * is a substituted carbocyclic or heterocyclic group, and R 1 and R * the total number of ring groups contained by R and R is three or more; (2) at least one R A a substituent other than hydrogen and bonded to a ring carbon atom contained in moiety A, with the proviso that the substituent is not 2,5-diisopropylphenyl; (3) L is CR, and R and R 2 bonded to form a benzene ring having at least one non-hydrogen substituent not included in ring D; (4) at least one R B is not hydrogen; and provided that two R A substituents or two R B substituents do not join together to form a cyano-substituted benzofuran ring.

12. The OLED of claim 11, 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 - benz [d] benz [4, 5] imidazo [3, 2-a] imidazole and azaborinine (5, 9-dioxo- 13b-bora naphtho [3, 2, 1-de] anthracene). 2 - benz [d] benz [4, 5] imidazo [3, 2-a] imidazole and azaborinine (5, 9-dioxo- 13b-bora naphtho [3, 2, 1-de] anthracene).

13. The OLED of claim 12, wherein the host is selected from the group consisting of: wherein: each of J1to J6is independently C or N; 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 represent mono-substitution, up to 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.

14. The OLED of claim 11, wherein the compound is a sensitizer, and the OLED further comprises an acceptor selected from the group consisting of a fluorescent emitter, a delayed fluorescent emitter, and combinations thereof.

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 comprises a compound comprising a structure of Formula I: wherein M is Pt or Pd; wherein moiety A is a monocyclic or polycyclic fused ring system, wherein each ring of the monocyclic or the polycyclic fused ring system is independently a 5- to 10-membered carbocyclic or heterocyclic ring; wherein X 1 - X 8 each independently C or N; Z 1 and Z 2 each independently is C or N; wherein K 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 ); wherein L is selected from the group consisting of a direct bond, O, S, Se, NR, BR, BRR', PR, CR, C=O, C=NR, C=CRR', C=S, CRR', SO, SO2, P(O)R, SiRR', and GeRR'; wherein R 1 is a substituted or unsubstituted carbocyclic or heterocyclic group; wherein R A , R B and R C each independently represent mono-substitution to the maximum allowable substitution or no substitution; wherein each R α , R β , R, R', R 2 , R A , R B , and R C 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 at least one of the following conditions is true: (1) at least one R A is R * wherein R * is a substituted carbocyclic or heterocyclic group, and R 1 and R * the total number of ring groups contained by R and R is three or more; (2) at least one R A a substituent other than hydrogen and bonded to a ring carbon atom contained in moiety A, with the proviso that the substituent is not 2,5-diisopropylphenyl; (3) L is CR, and R and R 2 bonded to form a benzene ring having at least one non-hydrogen substituent not included in ring D; (4) at least one R B is not hydrogen; and provided that two R A substituents or two R B substituents do not join together to form a cyano-substituted benzofuran ring.

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