Abstract:
This invention discloses novel ligands for metal complexes. These ligands comprise a new side chain, namely silacycloalkane, which could increase the dopants efficiency, tune the emission color, and enhance the lifetime.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Patent Application Ser. No. 62/318,398, filed Apr. 5, 2016, the entire contents of which is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present invention relates to compounds for use as emitters, and devices, such as organic light emitting diodes, including the same. 
       BACKGROUND 
       [0003]    Opto-electronic devices that make use of organic materials are becoming increasingly desirable for a number of reasons. Many of the materials used to make such devices are relatively inexpensive, so organic opto-electronic devices have the potential for cost advantages over inorganic devices. In addition, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications such as fabrication on a flexible substrate. Examples of organic opto-electronic devices include organic light emitting diodes/devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, the organic materials may have performance advantages over conventional materials. For example, the wavelength at which an organic emissive layer emits light may generally be readily tuned with appropriate dopants. 
         [0004]    OLEDs make use of thin organic films that emit light when voltage is applied across the device. OLEDs are becoming an increasingly interesting technology for use in applications such as flat panel displays, illumination, and backlighting. Several OLED materials and configurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety. 
         [0005]    One application for phosphorescent emissive molecules is a full color display. Industry standards for such a display call for pixels adapted to emit particular colors, referred to as “saturated” colors. In particular, these standards call for saturated red, green, and blue pixels. Alternatively the OLED can be designed to emit white light. In conventional liquid crystal displays emission from a white backlight is filtered using absorption filters to produce red, green and blue emission. The same technique can also be used with OLEDs. The white OLED can be either a single EML device or a stack structure. Color may be measured using CIE coordinates, which are well known to the art. 
         [0006]    One example of a green emissive molecule is tris(2-phenylpyridine) iridium, denoted Ir(ppy) 3 , which has the following structure: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0007]    In this, and later figures herein, we depict the dative bond from nitrogen to metal (here, Ir) as a straight line. 
         [0008]    As used herein, the term “organic” includes polymeric materials as well as small molecule organic materials that may be used to fabricate organic opto-electronic devices. “Small molecule” refers to any organic material that is not a polymer, and “small molecules” may actually be quite large. Small molecules may include repeat units in some circumstances. For example, using a long chain alkyl group as a substituent does not remove a molecule from the “small molecule” class. Small molecules may also be incorporated into polymers, for example as a pendent group on a polymer backbone or as a part of the backbone. Small molecules may also serve as the core moiety of a dendrimer, which consists of a series of chemical shells built on the core moiety. The core moiety of a dendrimer may be a fluorescent or phosphorescent small molecule emitter. A dendrimer may be a “small molecule,” and it is believed that all dendrimers currently used in the field of OLEDs are small molecules. 
         [0009]    As used herein, “top” means furthest away from the substrate, while “bottom” means closest to the substrate. Where a first layer is described as “disposed over” a second layer, the first layer is disposed further away from substrate. There may be other layers between the first and second layer, unless it is specified that the first layer is “in contact with” the second layer. For example, a cathode may be described as “disposed over” an anode, even though there are various organic layers in between. 
         [0010]    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. 
         [0011]    A ligand may be referred to as “photoactive” when it is believed that the ligand directly contributes to the photoactive properties of an emissive material. A ligand may be referred to as “ancillary” when it is believed that the ligand does not contribute to the photoactive properties of an emissive material, although an ancillary ligand may alter the properties of a photoactive ligand. 
         [0012]    As used herein, and as would be generally understood by one skilled in the art, a first “Highest Occupied Molecular Orbital” (HOMO) or “Lowest Unoccupied Molecular Orbital” (LUMO) energy level is “greater than” or “higher than” a second HOMO or LUMO energy level if the first energy level is closer to the vacuum energy level. Since ionization potentials (IP) are measured as a negative energy relative to a vacuum level, a higher HOMO energy level corresponds to an IP having a smaller absolute value (an IP that is less negative). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) having a smaller absolute value (an EA that is less negative). On a conventional energy level diagram, with the vacuum level at the top, the LUMO energy level of a material is higher than the HOMO energy level of the same material. A “higher” HOMO or LUMO energy level appears closer to the top of such a diagram than a “lower” HOMO or LUMO energy level. 
         [0013]    As used herein, and as would be generally understood by one skilled in the art, a first work function is “greater than” or “higher than” a second work function if the first work function has a higher absolute value. Because work functions are generally measured as negative numbers relative to vacuum level, this means that a “higher” work function is more negative. On a conventional energy level diagram, with the vacuum level at the top, a “higher” work function is illustrated as further away from the vacuum level in the downward direction. Thus, the definitions of HOMO and LUMO energy levels follow a different convention than work functions. 
         [0014]    More details on OLEDs, and the definitions described above, can be found in U.S. Pat. No. 7,279,704, which is incorporated herein by reference in its entirety. 
         [0015]    There is need in the art for novel emitters which can be used for electroluminescent devices. The present invention addresses this unmet need. 
       SUMMARY 
       [0016]    According to an embodiment, a composition is provided that includes a first compound; 
         [0017]    wherein the first compound is capable of functioning as an emitter in an organic light emitting device at room temperature; 
         [0018]    wherein the first compound has at least one aromatic ring and at least one substituent R; 
         [0019]    wherein each of the at least one substituent R is directly bonded to one of the aromatic rings; 
         [0020]    wherein each of the at least one substituent R has the formula 
         [0000]    
       
                 
         
             
             
         
       
     
         [0021]    wherein L is a direct bond or an organic linker; 
         [0022]    wherein ring A is a non-aromatic cyclic group containing X; 
         [0023]    wherein L bonds to ring A at a carbon atom C; 
         [0024]    wherein X is Si or Ge; 
         [0025]    wherein R X3  represents mono to the possible maximum number of substitution, or no substitution; 
         [0026]    wherein R X1 , R X2  and R X3  are each independently selected from the group consisting of: hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and 
         [0027]    wherein any adjacent substituents R X2  and R X3  are optionally joined or fused into a ring. 
         [0028]    According to another embodiment, an organic light emitting diode/device (OLED) is also provided. The OLED can include an anode, a cathode, and an organic layer, disposed between the anode and the cathode. The organic layer can include a compound of the invention. According to yet another embodiment, the organic light emitting device is incorporated into a device selected from a consumer product, an electronic component module, and/or a lighting panel. 
         [0029]    According to another embodiment, a consumer product comprising one or more organic light emitting devices is also provided. The organic light emitting device can include an anode, a cathode, and an organic layer, disposed between the anode and the cathode, wherein the organic layer can include a compound of the invention. The consumer product can be a flat panel display, a computer monitor, a medical monitors television, a billboard, a light for interior or exterior illumination and/or signaling, a heads-up display, a fully or partially transparent display, a flexible display, a laser printer, a telephone, a cell phone, tablet, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro-display that is less than 2 inches diagonal, a 3-D display, a virtual reality or augmented reality display, a vehicle, a video wall comprising multiple displays tiled together, a theater or stadium screen, and/or a sign. 
         [0030]    According to another embodiment, a formulation containing a compound of the invention is provided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]      FIG. 1  shows an organic light emitting device. 
           [0032]      FIG. 2  shows an inverted organic light emitting device that does not have a separate electron transport layer. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Generally, an OLED comprises at least one organic layer disposed between and electrically connected to an anode and a cathode. When a current is applied, the anode injects holes and the cathode injects electrons into the organic layer(s). The injected holes and electrons each migrate toward the oppositely charged electrode. When an electron and hole localize on the same molecule, an “exciton,” which is a localized electron-hole pair having an excited energy state, is formed. Light is emitted when the exciton relaxes via a photoemissive mechanism. In some cases, the exciton may be localized on an excimer or an exciplex. Non-radiative mechanisms, such as thermal relaxation, may also occur, but are generally considered undesirable. 
         [0034]    The initial OLEDs used emissive molecules that emitted light from their singlet states (“fluorescence”) as disclosed, for example, in U.S. Pat. No. 4,769,292, which is incorporated by reference in its entirety. Fluorescent emission generally occurs in a time frame of less than 10 nanoseconds. 
         [0035]    More recently, OLEDs having emissive materials that emit light from triplet states (“phosphorescence”) have been demonstrated. Baldo et al., “Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices,” Nature, vol. 395, 151-154, 1998; (“Baldo-I”) and Baldo et al., “Very high-efficiency green organic light-emitting devices based on electrophosphorescence,” Appl. Phys. Lett., vol. 75, No. 3, 4-6 (1999) (“Baldo-II”), are incorporated by reference in their entireties. Phosphorescence is described in more detail in U.S. Pat. No. 7,279,704 at cols. 5-6, which are incorporated by reference. 
         [0036]      FIG. 1  shows an organic light emitting device  100 . The figures are not necessarily drawn to scale. Device  100  may include a substrate  110 , an anode  115 , a hole injection layer  120 , a hole transport layer  125 , an electron blocking layer  130 , an emissive layer  135 , a hole blocking layer  140 , an electron transport layer  145 , an electron injection layer  150 , a protective layer  155 , a cathode  160 , and a barrier layer  170 . Cathode  160  is a compound cathode having a first conductive layer  162  and a second conductive layer  164 . Device  100  may be fabricated by depositing the layers described, in order. The properties and functions of these various layers, as well as example materials, are described in more detail in U.S. Pat. No. 7,279,704 at cols. 6-10, which are incorporated by reference. 
         [0037]    More examples for each of these layers are available. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Pat. No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F 4 -TCNQ at a molar ratio of 50:1, as disclosed in U.S. Patent Application Publication No. 2003/0230980, which is incorporated by reference in its entirety. Examples of emissive and host materials are disclosed in U.S. Pat. No. 6,303,238 to Thompson et al., which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1:1, as disclosed in U.S. Patent Application Publication No. 2003/0230980, which is incorporated by reference in its entirety. U.S. Pat. Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entireties, disclose examples of cathodes including compound cathodes having a thin layer of metal such as Mg:Ag with an overlying transparent, electrically-conductive, sputter-deposited ITO layer. The theory and use of blocking layers is described in more detail in U.S. Pat. No. 6,097,147 and U.S. Patent Application Publication No. 2003/0230980, which are incorporated by reference in their entireties. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004/0174116, which is incorporated by reference in its entirety. A description of protective layers may be found in U.S. Patent Application Publication No. 2004/0174116, which is incorporated by reference in its entirety. 
         [0038]      FIG. 2  shows an inverted OLED  200 . The device includes a substrate  210 , a cathode  215 , an emissive layer  220 , a hole transport layer  225 , and an anode  230 . Device  200  may be fabricated by depositing the layers described, in order. Because the most common OLED configuration has a cathode disposed over the anode, and device  200  has cathode  215  disposed under anode  230 , device  200  may be referred to as an “inverted” OLED. Materials similar to those described with respect to device  100  may be used in the corresponding layers of device  200 .  FIG. 2  provides one example of how some layers may be omitted from the structure of device  100 . 
         [0039]    The simple layered structure illustrated in  FIGS. 1 and 2  is provided by way of non-limiting example, and it is understood that embodiments of the invention may be used in connection with a wide variety of other structures. The specific materials and structures described are exemplary in nature, and other materials and structures may be used. Functional OLEDs may be achieved by combining the various layers described in different ways, or layers may be omitted entirely, based on design, performance, and cost factors. Other layers not specifically described may also be included. Materials other than those specifically described may be used. Although many of the examples provided herein describe various layers as comprising a single material, it is understood that combinations of materials, such as a mixture of host and dopant, or more generally a mixture, may be used. Also, 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 emissive layer  220 , and may be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED may be described as having an “organic layer” disposed between a cathode and an anode. This organic layer may comprise a single layer, or may further comprise multiple layers of different organic materials as described, for example, with respect to  FIGS. 1 and 2 . 
         [0040]    Structures and materials not specifically described may also be used, such as OLEDs comprised of polymeric materials (PLEDs) such as disclosed in U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of further example, OLEDs having a single organic layer may be used. OLEDs may be stacked, for example as described in U.S. Pat. No. 5,707,745 to Forrest et al, which is incorporated by reference in its entirety. The OLED structure may deviate from the simple layered structure illustrated in  FIGS. 1 and 2 . For example, the substrate may include an angled reflective surface to improve out-coupling, such as a mesa structure as described in U.S. Pat. No. 6,091,195 to Forrest et al., and/or a pit structure as described in U.S. Pat. No. 5,834,893 to Bulovic et al., which are incorporated by reference in their entireties. 
         [0041]    Unless otherwise specified, any of the layers of the various embodiments may be deposited by any suitable method. For the organic layers, preferred methods include thermal evaporation, ink-jet, such as described in U.S. Pat. Nos. 6,013,982 and 6,087,196, which are incorporated by reference in their entireties, organic vapor phase deposition (OVPD), such as described in U.S. Pat. No. 6,337,102 to Forrest et al., which is incorporated by reference in its entirety, and deposition by organic vapor jet printing (OVJP), such as described in U.S. Pat. No. 7,431,968, which is incorporated by reference in its entirety. Other suitable deposition methods include spin coating and other solution based processes. Solution based processes are preferably carried out in nitrogen or an inert atmosphere. For the other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding such as described in U.S. Pat. Nos. 6,294,398 and 6,468,819, which are incorporated by reference in their entireties, and patterning associated with some of the deposition methods such as ink jet and OVJD. Other methods may also be used. The materials to be deposited may be modified to make them compatible with a particular deposition method. For example, substituents such as alkyl and aryl groups, branched or unbranched, and preferably containing at least 3 carbons, may be used in small molecules to enhance their ability to undergo solution processing. Substituents having 20 carbons or more may be used, and 3-20 carbons is a preferred range. Materials with asymmetric structures may have better solution processibility than those having symmetric structures, because asymmetric materials may have a lower tendency to recrystallize. Dendrimer substituents may be used to enhance the ability of small molecules to undergo solution processing. 
         [0042]    Devices fabricated in accordance with embodiments of the present invention may further optionally comprise a barrier layer. One purpose of the barrier layer is to protect the electrodes and organic layers from damaging exposure to harmful species in the environment including moisture, vapor and/or gases, etc. The barrier layer may be deposited over, under or next to a substrate, an electrode, or over any other parts of a device including an edge. The barrier layer may comprise a single layer, or multiple layers. The barrier layer may be formed by various known chemical vapor deposition techniques and may include compositions having a single phase as well as compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may incorporate an inorganic or an organic compound or both. The preferred barrier layer comprises a mixture of a polymeric material and a non-polymeric material as described in U.S. Pat. No. 7,968,146, PCT Pat. Application Nos. PCT/US2007/023098 and PCT/US2009/042829, which are herein incorporated by reference in their entireties. To be considered a “mixture”, the aforesaid polymeric and non-polymeric materials comprising the barrier layer should be deposited under the same reaction conditions and/or at the same time. The weight ratio of polymeric to non-polymeric material may be in the range of 95:5 to 5:95. The polymeric material and the non-polymeric material may be created from the same precursor material. In one example, the mixture of a polymeric material and a non-polymeric material consists essentially of polymeric silicon and inorganic silicon. 
         [0043]    Devices fabricated in accordance with embodiments of the invention can be incorporated into a wide variety of electronic component modules (or units) that can be incorporated into a variety of electronic products or intermediate components. Examples of such electronic products or intermediate components include display screens, lighting devices such as discrete light source devices or lighting panels, etc. that can be utilized by the end-user product manufacturers. Such electronic component modules can optionally include the driving electronics and/or power source(s). Devices fabricated in accordance with embodiments of the invention can be incorporated into a wide variety of consumer products that have one or more of the electronic component modules (or units) incorporated therein. Such consumer products would include any kind of products that include one or more light source(s) and/or one or more of some type of visual displays. Some examples of such consumer products include flat panel displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior illumination and/or signaling, heads-up displays, fully or partially transparent displays, flexible displays, laser printers, telephones, cell phones, tablets, phablets, personal digital assistants (PDAs), wearable device, laptop computers, digital cameras, camcorders, viewfinders, micro-displays that are less than 2 inches diagonal, 3-D displays, virtual reality or augmented reality displays, vehicles, video walls comprising multiple displays tiled together, theater or stadium screen, or a sign. Various control mechanisms may be used to control devices fabricated in accordance with the present invention, including passive matrix and active matrix. Many of the devices are intended for use in a temperature range comfortable to humans, such as 18 degrees C. to 30 degrees C., and more preferably at room temperature (20-25 degrees C.), but could be used outside this temperature range, for example, from −40 degree C. to +80 degree C. 
         [0044]    The materials and structures described herein may have applications in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors may employ the materials and structures. More generally, organic devices, such as organic transistors, may employ the materials and structures. 
         [0045]    The term “halo,” “halogen,” or “halide” as used herein includes fluorine, chlorine, bromine, and iodine. 
         [0046]    The term “alkyl” as used herein contemplates both straight and branched chain alkyl radicals. Preferred alkyl groups are those containing from one to fifteen carbon atoms and includes methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, and the like. Additionally, the alkyl group may be optionally substituted. 
         [0047]    The term “cycloalkyl” as used herein contemplates cyclic alkyl radicals. Preferred cycloalkyl groups are those containing 3 to 10 ring carbon atoms and includes cyclopropyl, cyclopentyl, cyclohexyl, adamantyl, and the like. Additionally, the cycloalkyl group may be optionally substituted. 
         [0048]    The term “alkenyl” as used herein contemplates both straight and branched chain alkene radicals. Preferred alkenyl groups are those containing two to fifteen carbon atoms. Additionally, the alkenyl group may be optionally substituted. 
         [0049]    The term “alkynyl” as used herein contemplates both straight and branched chain alkyne radicals. Preferred alkynyl groups are those containing two to fifteen carbon atoms. Additionally, the alkynyl group may be optionally substituted. 
         [0050]    The terms “aralkyl” or “arylalkyl” as used herein are used interchangeably and contemplate an alkyl group that has as a substituent an aromatic group. Additionally, the aralkyl group may be optionally substituted. 
         [0051]    The term “heterocyclic group” as used herein contemplates aromatic and non-aromatic cyclic radicals. Hetero-aromatic cyclic radicals also means heteroaryl. Preferred hetero-non-aromatic cyclic groups are those containing 3 to 7 ring atoms which includes at least one hetero atom, and includes cyclic amines such as morpholino, piperdino, pyrrolidino, and the like, and cyclic ethers, such as tetrahydrofuran, tetrahydropyran, and the like. Additionally, the heterocyclic group may be optionally substituted. 
         [0052]    The term “aryl” or “aromatic group” as used herein contemplates single-ring groups and polycyclic ring systems. The polycyclic rings may have two or more rings in which two carbons are common to two adjoining rings (the rings are “fused”) wherein at least one of the rings is aromatic, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryl, heterocycles, and/or heteroaryls. Preferred aryl groups are those containing six to thirty carbon atoms, preferably six to twenty carbon atoms, more preferably six to twelve carbon atoms. Especially preferred is an aryl group having six carbons, ten carbons or twelve carbons. Suitable aryl groups include phenyl, biphenyl, triphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene, preferably phenyl, biphenyl, triphenyl, triphenylene, fluorene, and naphthalene. Additionally, the aryl group may be optionally substituted. 
         [0053]    The term “heteroaryl” as used herein contemplates single-ring hetero-aromatic groups that may include from one to five heteroatoms. The term heteroaryl also includes polycyclic hetero-aromatic systems having two or more rings in which two atoms are common to two adjoining rings (the rings are “fused”) wherein at least one of the rings is a heteroaryl, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryl, heterocycles, and/or heteroaryls. Preferred heteroaryl groups are those containing three to thirty carbon atoms, preferably three to twenty carbon atoms, more preferably three to twelve carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine, preferably dibenzothiophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 1,2-azaborine, 1,3-azaborine, 1,4-azaborine, borazine, and aza-analogs thereof. Additionally, the heteroaryl group may be optionally substituted. 
         [0054]    The alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, heterocyclic group, aryl, and heteroaryl may be unsubstituted or may be substituted with one or more substituents selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof. 
         [0055]    As used herein, “substituted” indicates that a substituent other than H is bonded to the relevant position, such as carbon. Thus, for example, where R 1  is mono-substituted, then one R 1  must be other than H. Similarly, where R 1  is di-substituted, then two of R 1  must be other than H. Similarly, where R 1  is unsubstituted, is hydrogen for all available positions. 
         [0056]    The “aza” designation in the fragments described herein, i.e. aza-dibenzofuran, aza-dibenzothiophene, etc. means that one or more of the C—H groups in the respective fragment can be replaced by a nitrogen atom, for example, and without any limitation, azatriphenylene encompasses both dibenzo[f,h]quinoxaline and dibenzo[f,h]quinoline. One of ordinary skill in the art can readily envision other nitrogen analogs of the aza-derivatives described above, and all such analogs are intended to be encompassed by the terms as set forth herein. 
         [0057]    It is to be understood that when a molecular fragment is described as being a substituent or otherwise attached to another moiety, its name may be written as if it were a fragment (e.g. phenyl, phenylene, naphthyl, dibenzofuryl) or as if it were the whole molecule (e.g. benzene, naphthalene, dibenzofuran). As used herein, these different ways of designating a substituent or attached fragment are considered to be equivalent. 
         [0058]    In one aspect, this invention includes phosphorescent metal complexes containing substituents with the silacycloalkane moiety. This side chain can be added at different positions on a wide variety of ligands including NHC carbene, imidazole, pyridine, pyrazine, pyrimidine, quinoline, iso-quinoline, quinazoline, and quinoxaline. This substitution was found to be useful for multiple reasons. The lifetime of trimethylsilyl containing emitters may be improved by inserting a methylene spacer between the silyl group and aromatic ring. Further improvement in lifetime may be achieved by affixing the silicon atom(s) in a cycloalkyl ring. In addition, the substituent is very bulky, which may prevent packing in the solid state and increase PLQY. 
       Compounds of the Invention 
       [0059]    In one aspect, the present invention includes a composition comprising a first compound; 
         [0060]    wherein the first compound is capable of functioning as an emitter in an organic light emitting device at room temperature; 
         [0061]    wherein the first compound has at least one aromatic ring and at least one substituent R; 
         [0062]    wherein each of the at least one R is directly bonded to one of the aromatic rings; 
         [0063]    wherein each of the at least one R has the formula of 
         [0000]    
       
                 
         
             
             
         
       
     
         [0064]    wherein L is a direct bond or an organic linker; 
         [0065]    wherein ring A is a non-aromatic cyclic group containing X; 
         [0066]    wherein L bonds to ring A at a carbon atom C; 
         [0067]    wherein X is Si or Ge; 
         [0068]    wherein R X3  represents mono to the possible maximum number of substitution, or no substitution; 
         [0069]    wherein R X1 , R X2  and R X3  are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and 
         [0070]    wherein any adjacent substitutents of R X1 , R X2  and R X3  are optionally joined or fused into a ring. 
         [0071]    In one embodiment, L is a direct bond. In another embodiment, L is an organic linker selected from the group consisting of: NR X4 , SiR X4 R X5 , GeR X4 R X5 , alkyl, cycloalkyl, and combinations thereof; wherein R X4  and R X5  are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and wherein any adjacent substituents R X1 , R X2  and R X3 , R X4  and R X5  are optionally joined or fused into a ring. 
         [0072]    In one embodiment, X is Si. In another embodiment, X is Ge. 
         [0073]    In one embodiment, R X1  and R X2  are each independently selected from the group consisting of alkyl, cycloalkyl, partially or fully deuterated variants thereof, partially or fully fluorinated variants thereof, and combinations thereof. In another embodiment, R X1  and R X2  are joined or fused into a ring. 
         [0074]    In one embodiment, each R X3  is independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, and combinations thereof. 
         [0075]    In one embodiment, ring A consists of atoms selected from the group consisting of C, Si, Ge, N, O, and S. In another embodiment, ring A consists of at least two atoms selected from the group consisting of Si, Ge, N, O, and S. In another embodiment, ring A consists of at least three atoms selected from the group consisting of Si, Ge, N, O, and S. In one embodiment, ring A is selected from the group consisting of 
         [0000]    
       
                 
         
             
             
         
       
     
         [0076]    wherein m and n are each independently an integer of 1 to 5. In one embodiment, m+n is 3 or 4. 
         [0077]    In one embodiment, in each of the at least one substituent R, ring A is monocyclic. In another embodiment, in each of the at least one substituent R, ring A is a bicyclic group. In another embodiment, each of the at least one substituent R is independently selected from the group consisting of: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0078]    In one embodiment, the first compound is a metal coordination complex having a metal-carbon bond. In one embodiment, the metal is selected from the group consisting of: Ir, Rh, Re, Ru, Os, Pt, Au, and Cu. In one embodiment, the metal is Ir. In another embodiment, the metal is Pt. 
         [0079]    In one embodiment, the first compound has the formula of M(L 1 ) x (L 2 ) y (L 3 ) z ; 
         [0080]    wherein L 1 , L 2  and L 3  can be the same or different; 
         [0081]    wherein x is 1, 2, or 3; 
         [0000]    wherein y is 0, 1, or 2; 
         [0082]    wherein z is 0, 1, or 2; 
         [0083]    wherein x+y+z is the oxidation state of the metal M; 
         [0084]    wherein L 1 , L 2  and L 3  are each independently selected from the group consisting of: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0085]    wherein each X 1  to X 17  are independently selected from the group consisting of carbon and nitrogen; 
         [0086]    wherein X is selected from the group consisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO 2 , CR′R″, SiR′R″, and GeR′R″; 
         [0087]    wherein R′ and R″ are optionally fused or joined to form a ring; 
         [0088]    wherein each R a , R b , R e , and R d  may represent from mono substitution to the possible maximum number of substitution, or no substitution; 
         [0089]    wherein R′, R″, R a , R b , R e , and R d  are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; 
         [0090]    wherein any two adjacent substituents of R a , R b , R c  and R d  are optionally fused or joined to form a ring or form a multidentate ligand; and 
         [0091]    wherein at least one of the R a , R b , R c , and R d  includes at least one substituent R. 
         [0092]    In one embodiment, the first compound has the formula of Ir(L 1 ) 2 (L 2 ). In another embodiment, the first compound has the formula of Pt(L 1 ) 2  or Pt(L 1 )(L 2 ). 
         [0093]    In another embodiment, L 1  has a formula selected from the group consisting of: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0094]    wherein L 2  has the formula: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0095]    In one embodiment, L 2  has the formula: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0096]    wherein R e , R f , R h , and R i  are independently selected from group consisting of alkyl, cycloalkyl, aryl, and heteroaryl; 
         [0097]    wherein at least one of R e , R f , R h , and R i  has at least two carbon atoms; 
         [0098]    wherein R g  is selected from group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof. 
         [0099]    In one embodiment, L 1  and L 2  are different and are each independently selected from a group consisting of: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0100]    In another embodiment, L 1  and L 2  are each independently selected from the group consisting of: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0101]    In one embodiment, L 1  is connected to the other L 1  or L 2  to form a tetradentate ligand. 
         [0102]    In one embodiment, at least one of R a , R b , R c  and R d  includes an alkyl or cycloalkyl group that includes CD, CD 2 , or CD 3 , wherein D is deuterium. 
         [0103]    In one embodiment, at least one of L 1 , L 2 , and L 3  is selected from the group consisting of: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0104]    In another embodiment, at least one of L 1 , L 2 , and L 3  is selected from the group consisting of: 
         [0000]    
       
         
               
             
           
               
                   
               
             
             
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B1 , L A1   
               
               
                 R 2  = R A2 , R 1  = R B1 , L A2   
               
               
                 R 2  = R A3 , R 1  = R B1 , L A3   
               
               
                 R 2  = R A4 , R 1  = R B1 , L A4   
               
               
                 R 2  = R A5 , R 1  = R B1 , L A5   
               
               
                 R 2  = R A1 , R 1  = R B2 , L A6   
               
               
                 R 2  = R A2 , R 1  = R B2 , L A7   
               
               
                 R 2  = R A3 , R 1  = R B2 , L A8   
               
               
                 R 2  = R A4 , R 1  = R B2 , L A9   
               
               
                 R 2  = R A5 , R 1  = R B2 , L A10   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B1 , L A11   
               
               
                 R 3  = R A2 , R 1  = R B1 , L A12   
               
               
                 R 3  = R A3 , R 1  = R B1 , L A13   
               
               
                 R 3  = R A4 , R 1  = R B1 , L A14   
               
               
                 R 3  = R A5 , R 1  = R B1 , L A15   
               
               
                 R 3  = R A1 , R 1  = R B2 , L A16   
               
               
                 R 3  = R A2 , R 1  = R B2 , L A17   
               
               
                 R 3  = R A3 , R 1  = R B2 , L A18   
               
               
                 R 3  = R A4 , R 1  = R B2 , L A19   
               
               
                 R 3  = R A5 , R 1  = R B2 , L A20   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 4  = R A1 , R 1  = R B1 , L A21   
               
               
                 R 4  = R A2 , R 1  = R B1 , L A22   
               
               
                 R 4  = R A3 , R 1  = R B1 , L A23   
               
               
                 R 4  = R A4 , R 1  = R B1 , L A24   
               
               
                 R 4  = R A5 , R 1  = R B1 , L A25   
               
               
                 R 4  = R A1 , R 1  = R B2 , L A26   
               
               
                 R 4  = R A2 , R 1  = R B2 , L A27   
               
               
                 R 4  = R A3 , R 1  = R B2 , L A28   
               
               
                 R 4  = R A4 , R 1  = R B2 , L A29   
               
               
                 R 4  = R A5 , R 1  = R B2 , L A30   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 5  = R A1 , R 1  = R B1 , L A31   
               
               
                 R 5  = R A2 , R 1  = R B1 , L A32   
               
               
                 R 5  = R A3 , R 1  = R B1 , L A33   
               
               
                 R 5  = R A4 , R 1  = R B1 , L A34   
               
               
                 R 5  = R A5 , R 1  = R B1 , L A35   
               
               
                 R 5  = R A1 , R 1  = R B2 , L A36   
               
               
                 R 5  = R A2 , R 1  = R B2 , L A37   
               
               
                 R 5  = R A3 , R 1  = R B2 , L A38   
               
               
                 R 5  = R A4 , R 1  = R B2 , L A39   
               
               
                 R 5  = R A5 , R 1  = R B2 , L A40   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B1 , L A41   
               
               
                 R 2  = R A2 , R 1  = R B1 , L A42   
               
               
                 R 2  = R A3 , R 1  = R B1 , L A43   
               
               
                 R 2  = R A4 , R 1  = R B1 , L A44   
               
               
                 R 2  = R A5 , R 1  = R B1 , L A45   
               
               
                 R 2  = R A1 , R 1  = R B2 , L A46   
               
               
                 R 2  = R A2 , R 1  = R B2 , L A47   
               
               
                 R 2  = R A3 , R 1  = R B2 , L A48   
               
               
                 R 2  = R A4 , R 1  = R B2 , L A49   
               
               
                 R 2  = R A5 , R 1  = R B2 , L A50   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B1 , L A51   
               
               
                 R 3  = R A2 , R 1  = R B1 , L A52   
               
               
                 R 3  = R A3 , R 1  = R B1 , L A53   
               
               
                 R 3  = R A4 , R 1  = R B1 , L A54   
               
               
                 R 3  = R A5 , R 1  = R B1 , L A55   
               
               
                 R 3  = R A1 , R 1  = R B2 , L A56   
               
               
                 R 3  = R A2 , R 1  = R B2 , L A57   
               
               
                 R 3  = R A3 , R 1  = R B2 , L A58   
               
               
                 R 3  = R A4 , R 1  = R B2 , L A59   
               
               
                 R 3  = R A5 , R 1  = R B2 , L A60   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 4  = R A1 , R 1  = R B1 , L A61   
               
               
                 R 4  = R A2 , R 1  = R B1 , L A62   
               
               
                 R 4  = R A3 , R 1  = R B1 , L A63   
               
               
                 R 4  = R A4 , R 1  = R B1 , L A64   
               
               
                 R 4  = R A5 , R 1  = R B1 , L A65   
               
               
                 R 4  = R A1 , R 1  = R B2 , L A66   
               
               
                 R 4  = R A2 , R 1  = R B2 , L A67   
               
               
                 R 4  = R A3 , R 1  = R B2 , L A68   
               
               
                 R 4  = R A4 , R 1  = R B2 , L A69   
               
               
                 R 4  = R A5 , R 1  = R B2 , L A70   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 5  = R A1 , R 1  = R B1 , L A71   
               
               
                 R 5  = R A2 , R 1  = R B1 , L A72   
               
               
                 R 5  = R A3 , R 1  = R B1 , L A73   
               
               
                 R 5  = R A4 , R 1  = R B1 , L A74   
               
               
                 R 5  = R A5 , R 1  = R B1 , L A75   
               
               
                 R 5  = R A1 , R 1  = R B2 , L A76   
               
               
                 R 5  = R A2 , R 1  = R B2 , L A77   
               
               
                 R 5  = R A3 , R 1  = R B2 , L A78   
               
               
                 R 5  = R A4 , R 1  = R B2 , L A79   
               
               
                 R 5  = R A5 , R 1  = R B2 , L A80   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B1 , L A81   
               
               
                 R 2  = R A2 , R 1  = R B1 , L A82   
               
               
                 R 2  = R A3 , R 1  = R B1 , L A83   
               
               
                 R 2  = R A4 , R 1  = R B1 , L A84   
               
               
                 R 2  = R A5 , R 1  = R B1 , L A85   
               
               
                 R 2  = R A1 , R 1  = R B2 , L A86   
               
               
                 R 2  = R A2 , R 1  = R B2 , L A87   
               
               
                 R 2  = R A3 , R 1  = R B2 , L A88   
               
               
                 R 2  = R A4 , R 1  = R B2 , L A89   
               
               
                 R 2  = R A5 , R 1  = R B2 , L A90   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B1 , L A91   
               
               
                 R 3  = R A2 , R 1  = R B1 , L A92   
               
               
                 R 3  = R A3 , R 1  = R B1 , L A93   
               
               
                 R 3  = R A4 , R 1  = R B1 , L A94   
               
               
                 R 3  = R A5 , R 1  = R B1 , L A95   
               
               
                 R 3  = R A1 , R 1  = R B2 , L A96   
               
               
                 R 3  = R A2 , R 1  = R B2 , L A97   
               
               
                 R 3  = R A3 , R 1  = R B2 , L A98   
               
               
                 R 3  = R A4 , R 1  = R B2 , L A99   
               
               
                 R 3  = R A5 , R 1  = R B2 , L A100   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 4  = R A1 , R 1  = R B1 , L A101   
               
               
                 R 4  = R A2 , R 1  = R B1 , L A102   
               
               
                 R 4  = R A3 , R 1  = R B1 , L A103   
               
               
                 R 4  = R A4 , R 1  = R B1 , L A104   
               
               
                 R 4  = R A5 , R 1  = R B1 , L A105   
               
               
                 R 4  = R A1 , R 1  = R B2 , L A106   
               
               
                 R 4  = R A2 , R 1  = R B2 , L A107   
               
               
                 R 4  = R A3 , R 1  = R B2 , L A108   
               
               
                 R 4  = R A4 , R 1  = R B2 , L A109   
               
               
                 R 4  = R A5 , R 1  = R B2 , L A110   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B1 , L A111   
               
               
                 R 2  = R A2 , R 1  = R B1 , L A112   
               
               
                 R 2  = R A3 , R 1  = R B1 , L A113   
               
               
                 R 2  = R A4 , R 1  = R B1 , L A114   
               
               
                 R 2  = R A5 , R 1  = R B1 , L A115   
               
               
                 R 2  = R A1 , R 1  = R B2 , L A116   
               
               
                 R 2  = R A2 , R 1  = R B2 , L A117   
               
               
                 R 2  = R A3 , R 1  = R B2 , L A118   
               
               
                 R 2  = R A4 , R 1  = R B2 , L A119   
               
               
                 R 2  = R A5 , R 1  = R B2 , L A120   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B1 , L A121   
               
               
                 R 3  = R A2 , R 1  = R B1 , L A122   
               
               
                 R 3  = R A3 , R 1  = R B1 , L A123   
               
               
                 R 3  = R A4 , R 1  = R B1 , L A124   
               
               
                 R 3  = R A5 , R 1  = R B1 , L A125   
               
               
                 R 3  = R A1 , R 1  = R B2 , L A126   
               
               
                 R 3  = R A2 , R 1  = R B2 , L A127   
               
               
                 R 3  = R A3 , R 1  = R B2 , L A128   
               
               
                 R 3  = R A4 , R 1  = R B2 , L A129   
               
               
                 R 3  = R A5 , R 1  = R B2 , L A130   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 4  = R A1 , R 1  = R B1 , L A131   
               
               
                 R 4  = R A2 , R 1  = R B1 , L A132   
               
               
                 R 4  = R A3 , R 1  = R B1 , L A133   
               
               
                 R 4  = R A4 , R 1  = R B1 , L A134   
               
               
                 R 4  = R A5 , R 1  = R B1 , L A135   
               
               
                 R 4  = R A1 , R 1  = R B2 , L A136   
               
               
                 R 4  = R A2 , R 1  = R B2 , L A137   
               
               
                 R 4  = R A3 , R 1  = R B2 , L A138   
               
               
                 R 4  = R A4 , R 1  = R B2 , L A139   
               
               
                 R 4  = R A5 , R 1  = R B2 , L A140   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B1 , L A141   
               
               
                 R 2  = R A2 , R 1  = R B1 , L A142   
               
               
                 R 2  = R A3 , R 1  = R B1 , L A143   
               
               
                 R 2  = R A4 , R 1  = R B1 , L A144   
               
               
                 R 2  = R A5 , R 1  = R B1 , L A145   
               
               
                 R 2  = R A1 , R 1  = R B2 , L A146   
               
               
                 R 2  = R A2 , R 1  = R B2 , L A147   
               
               
                 R 2  = R A3 , R 1  = R B2 , L A148   
               
               
                 R 2  = R A4 , R 1  = R B2 , L A149   
               
               
                 R 2  = R A5 , R 1  = R B2 , L A150   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B1 , L A151   
               
               
                 R 3  = R A2 , R 1  = R B1 , L A152   
               
               
                 R 3  = R A3 , R 1  = R B1 , L A153   
               
               
                 R 3  = R A4 , R 1  = R B1 , L A154   
               
               
                 R 3  = R A5 , R 1  = R B1 , L A155   
               
               
                 R 3  = R A1 , R 1  = R B2 , L A156   
               
               
                 R 3  = R A2 , R 1  = R B2 , L A157   
               
               
                 R 3  = R A3 , R 1  = R B2 , L A158   
               
               
                 R 3  = R A4 , R 1  = R B2 , L A159   
               
               
                 R 3  = R A5 , R 1  = R B2 , L A160   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B1 , L A161   
               
               
                 R 2  = R A2 , R 1  = R B1 , L A162   
               
               
                 R 2  = R A3 , R 1  = R B1 , L A163   
               
               
                 R 2  = R A4 , R 1  = R B1 , L A164   
               
               
                 R 2  = R A5 , R 1  = R B1 , L A165   
               
               
                 R 2  = R A1 , R 1  = R B2 , L A166   
               
               
                 R 2  = R A2 , R 1  = R B2 , L A167   
               
               
                 R 2  = R A3 , R 1  = R B2 , L A168   
               
               
                 R 2  = R A4 , R 1  = R B2 , L A169   
               
               
                 R 2  = R A5 , R 1  = R B2 , L A170   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B1 , L A171   
               
               
                 R 3  = R A2 , R 1  = R B1 , L A172   
               
               
                 R 3  = R A3 , R 1  = R B1 , L A173   
               
               
                 R 3  = R A4 , R 1  = R B1 , L A174   
               
               
                 R 3  = R A5 , R 1  = R B1 , L A175   
               
               
                 R 3  = R A1 , R 1  = R B2 , L A176   
               
               
                 R 3  = R A2 , R 1  = R B2 , L A177   
               
               
                 R 3  = R A3 , R 1  = R B2 , L A178   
               
               
                 R 3  = R A4 , R 1  = R B2 , L A179   
               
               
                 R 3  = R A5 , R 1  = R B2 , L A180   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 4  = R A1 , R 1  = R B1 , L A181   
               
               
                 R 4  = R A2 , R 1  = R B1 , L A182   
               
               
                 R 4  = R A3 , R 1  = R B1 , L A183   
               
               
                 R 4  = R A4 , R 1  = R B1 , L A184   
               
               
                 R 4  = R A5 , R 1  = R B1 , L A185   
               
               
                 R 4  = R A1 , R 1  = R B2 , L A186   
               
               
                 R 4  = R A2 , R 1  = R B2 , L A187   
               
               
                 R 4  = R A3 , R 1  = R B2 , L A188   
               
               
                 R 4  = R A4 , R 1  = R B2 , L A189   
               
               
                 R 4  = R A5 , R 1  = R B2 , L A190   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 5  = R A1 , R 1  = R B1 , L A191   
               
               
                 R 5  = R A2 , R 1  = R B1 , L A192   
               
               
                 R 5  = R A3 , R 1  = R B1 , L A193   
               
               
                 R 5  = R A4 , R 1  = R B1 , L A194   
               
               
                 R 5  = R A5 , R 1  = R B1 , L A195   
               
               
                 R 5  = R A1 , R 1  = R B2 , L A196   
               
               
                 R 5  = R A2 , R 1  = R B2 , L A197   
               
               
                 R 5  = R A3 , R 1  = R B2 , L A198   
               
               
                 R 5  = R A4 , R 1  = R B2 , L A199   
               
               
                 R 5  = R A5 , R 1  = R B2 , L A200   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B1 , L A201   
               
               
                 R 2  = R A2 , R 1  = R B1 , L A202   
               
               
                 R 2  = R A3 , R 1  = R B1 , L A203   
               
               
                 R 2  = R A4 , R 1  = R B1 , L A204   
               
               
                 R 2  = R A5 , R 1  = R B1 , L A205   
               
               
                 R 2  = R A1 , R 1  = R B2 , L A206   
               
               
                 R 2  = R A2 , R 1  = R B2 , L A207   
               
               
                 R 2  = R A3 , R 1  = R B2 , L A208   
               
               
                 R 2  = R A4 , R 1  = R B2 , L A209   
               
               
                 R 2  = R A5 , R 1  = R B2 , L A210   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B1 , L A211   
               
               
                 R 3  = R A2 , R 1  = R B1 , L A212   
               
               
                 R 3  = R A3 , R 1  = R B1 , L A213   
               
               
                 R 3  = R A4 , R 1  = R B1 , L A214   
               
               
                 R 3  = R A5 , R 1  = R B1 , L A215   
               
               
                 R 3  = R A1 , R 1  = R B2 , L A216   
               
               
                 R 3  = R A2 , R 1  = R B2 , L A217   
               
               
                 R 3  = R A3 , R 1  = R B2 , L A218   
               
               
                 R 3  = R A4 , R 1  = R B2 , L A219   
               
               
                 R 3  = R A5 , R 1  = R B2 , L A220   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 4  = R A1 , R 1  = R B1 , L A221   
               
               
                 R 4  = R A2 , R 1  = R B1 , L A222   
               
               
                 R 4  = R A3 , R 1  = R B1 , L A223   
               
               
                 R 4  = R A4 , R 1  = R B1 , L A224   
               
               
                 R 4  = R A5 , R 1  = R B1 , L A225   
               
               
                 R 4  = R A1 , R 1  = R B2 , L A226   
               
               
                 R 4  = R A2 , R 1  = R B2 , L A227   
               
               
                 R 4  = R A3 , R 1  = R B2 , L A228   
               
               
                 R 4  = R A4 , R 1  = R B2 , L A229   
               
               
                 R 4  = R A5 , R 1  = R B2 , L A230   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 5  = R A1 , R 1  = R B1 , L A231   
               
               
                 R 5  = R A2 , R 1  = R B1 , L A232   
               
               
                 R 5  = R A3 , R 1  = R B1 , L A233   
               
               
                 R 5  = R A4 , R 1  = R B1 , L A234   
               
               
                 R 5  = R A5 , R 1  = R B1 , L A235   
               
               
                 R 5  = R A1 , R 1  = R B2 , L A236   
               
               
                 R 5  = R A2 , R 1  = R B2 , L A237   
               
               
                 R 5  = R A3 , R 1  = R B2 , L A238   
               
               
                 R 5  = R A4 , R 1  = R B2 , L A239   
               
               
                 R 5  = R A5 , R 1  = R B2 , L A240   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B3 , L A241   
               
               
                 R 2  = R A2 , R 1  = R B3 , L A242   
               
               
                 R 2  = R A3 , R 1  = R B3 , L A243   
               
               
                 R 2  = R A4 , R 1  = R B3 , L A244   
               
               
                 R 2  = R A5 , R 1  = R B3 , L A245   
               
               
                 R 2  = R A1 , R 1  = R B4 , L A246   
               
               
                 R 2  = R A2 , R 1  = R B4 , L A247   
               
               
                 R 2  = R A3 , R 1  = R B4 , L A248   
               
               
                 R 2  = R A4 , R 1  = R B4 , L A249   
               
               
                 R 2  = R A5 , R 1  = R B4 , L A250   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B3 , L A251   
               
               
                 R 3  = R A2 , R 1  = R B3 , L A252   
               
               
                 R 3  = R A3 , R 1  = R B3 , L A253   
               
               
                 R 3  = R A4 , R 1  = R B3 , L A254   
               
               
                 R 3  = R A5 , R 1  = R B3 , L A255   
               
               
                 R 3  = R A1 , R 1  = R B4 , L A256   
               
               
                 R 3  = R A2 , R 1  = R B4 , L A257   
               
               
                 R 3  = R A3 , R 1  = R B4 , L A258   
               
               
                 R 3  = R A4 , R 1  = R B4 , L A259   
               
               
                 R 3  = R A5 , R 1  = R B4 , L A260   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 4  = R A1 , R 1  = R B3 , L A261   
               
               
                 R 4  = R A2 , R 1  = R B3 , L A262   
               
               
                 R 4  = R A3 , R 1  = R B3 , L A263   
               
               
                 R 4  = R A4 , R 1  = R B3 , L A264   
               
               
                 R 4  = R A5 , R 1  = R B3 , L A265   
               
               
                 R 4  = R A1 , R 1  = R B4 , L A266   
               
               
                 R 4  = R A2 , R 1  = R B4 , L A267   
               
               
                 R 4  = R A3 , R 1  = R B4 , L A268   
               
               
                 R 4  = R A4 , R 1  = R B4 , L A269   
               
               
                 R 4  = R A5 , R 1  = R B4 , L A270   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 5  = R A1 , R 1  = R B3 , L A271   
               
               
                 R 5  = R A2 , R 1  = R B3 , L A272   
               
               
                 R 5  = R A3 , R 1  = R B3 , L A273   
               
               
                 R 5  = R A4 , R 1  = R B3 , L A274   
               
               
                 R 5  = R A5 , R 1  = R B3 , L A275   
               
               
                 R 5  = R A1 , R 1  = R B4 , L A276   
               
               
                 R 5  = R A2 , R 1  = R B4 , L A277   
               
               
                 R 5  = R A3 , R 1  = R B4 , L A278   
               
               
                 R 5  = R A4 , R 1  = R B4 , L A279   
               
               
                 R 5  = R A5 , R 1  = R B4 , L A280   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B3 , L A281   
               
               
                 R 2  = R A2 , R 1  = R B3 , L A282   
               
               
                 R 2  = R A3 , R 1  = R B3 , L A283   
               
               
                 R 2  = R A4 , R 1  = R B3 , L A284   
               
               
                 R 2  = R A5 , R 1  = R B3 , L A285   
               
               
                 R 2  = R A1 , R 1  = R B4 , L A286   
               
               
                 R 2  = R A2 , R 1  = R B4 , L A287   
               
               
                 R 2  = R A3 , R 1  = R B4 , L A288   
               
               
                 R 2  = R A4 , R 1  = R B4 , L A289   
               
               
                 R 2  = R A5 , R 1  = R B4 , L A290   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B3 , L A291   
               
               
                 R 3  = R A2 , R 1  = R B3 , L A292   
               
               
                 R 3  = R A3 , R 1  = R B3 , L A293   
               
               
                 R 3  = R A4 , R 1  = R B3 , L A294   
               
               
                 R 3  = R A5 , R 1  = R B3 , L A295   
               
               
                 R 3  = R A1 , R 1  = R B4 , L A296   
               
               
                 R 3  = R A2 , R 1  = R B4 , L A297   
               
               
                 R 3  = R A3 , R 1  = R B4 , L A298   
               
               
                 R 3  = R A4 , R 1  = R B4 , L A299   
               
               
                 R 3  = R A5 , R 1  = R B4 , L A300   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 4  = R A1 , R 1  = R B3 , L A301   
               
               
                 R 4  = R A2 , R 1  = R B3 , L A302   
               
               
                 R 4  = R A3 , R 1  = R B3 , L A303   
               
               
                 R 4  = R A4 , R 1  = R B3 , L A304   
               
               
                 R 4  = R A5 , R 1  = R B3 , L A305   
               
               
                 R 4  = R A1 , R 1  = R B4 , L A306   
               
               
                 R 4  = R A2 , R 1  = R B4 , L A307   
               
               
                 R 4  = R A3 , R 1  = R B4 , L A308   
               
               
                 R 4  = R A4 , R 1  = R B4 , L A309   
               
               
                 R 4  = R A5 , R 1  = R B4 , L A310   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 5  = R A1 , R 1  = R B3 , L A311   
               
               
                 R 5  = R A2 , R 1  = R B3 , L A312   
               
               
                 R 5  = R A3 , R 1  = R B3 , L A313   
               
               
                 R 5  = R A4 , R 1  = R B3 , L A314   
               
               
                 R 5  = R A5 , R 1  = R B3 , L A315   
               
               
                 R 5  = R A1 , R 1  = R B4 , L A316   
               
               
                 R 5  = R A2 , R 1  = R B4 , L A317   
               
               
                 R 5  = R A3 , R 1  = R B4 , L A318   
               
               
                 R 5  = R A4 , R 1  = R B4 , L A319   
               
               
                 R 5  = R A5 , R 1  = R B4 , L A320   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B3 , L A321   
               
               
                 R 2  = R A2 , R 1  = R B3 , L A322   
               
               
                 R 2  = R A3 , R 1  = R B3 , L A323   
               
               
                 R 2  = R A4 , R 1  = R B3 , L A324   
               
               
                 R 2  = R A5 , R 1  = R B3 , L A325   
               
               
                 R 2  = R A1 , R 1  = R B4 , L A326   
               
               
                 R 2  = R A2 , R 1  = R B4 , L A327   
               
               
                 R 2  = R A3 , R 1  = R B4 , L A328   
               
               
                 R 2  = R A4 , R 1  = R B4 , L A329   
               
               
                 R 2  = R A5 , R 1  = R B4 , L A330   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B3 , L A331   
               
               
                 R 3  = R A2 , R 1  = R B3 , L A332   
               
               
                 R 3  = R A3 , R 1  = R B3 , L A333   
               
               
                 R 3  = R A4 , R 1  = R B3 , L A334   
               
               
                 R 3  = R A5 , R 1  = R B3 , L A335   
               
               
                 R 3  = R A1 , R 1  = R B4 , L A336   
               
               
                 R 3  = R A2 , R 1  = R B4 , L A337   
               
               
                 R 3  = R A3 , R 1  = R B4 , L A338   
               
               
                 R 3  = R A4 , R 1  = R B4 , L A339   
               
               
                 R 3  = R A5 , R 1  = R B4 , L A340   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 4  = R A1 , R 1  = R B3 , L A341   
               
               
                 R 4  = R A2 , R 1  = R B3 , L A342   
               
               
                 R 4  = R A3 , R 1  = R B3 , L A343   
               
               
                 R 4  = R A4 , R 1  = R B3 , L A344   
               
               
                 R 4  = R A5 , R 1  = R B3 , L A345   
               
               
                 R 4  = R A1 , R 1  = R B4 , L A346   
               
               
                 R 4  = R A2 , R 1  = R B4 , L A347   
               
               
                 R 4  = R A3 , R 1  = R B4 , L A348   
               
               
                 R 4  = R A4 , R 1  = R B4 , L A349   
               
               
                 R 4  = R A5 , R 1  = R B4 , L A350   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 5  = R A1 , R 1  = R B3 , L A351   
               
               
                 R 5  = R A2 , R 1  = R B3 , L A352   
               
               
                 R 5  = R A3 , R 1  = R B3 , L A353   
               
               
                 R 5  = R A4 , R 1  = R B3 , L A354   
               
               
                 R 5  = R A5 , R 1  = R B3 , L A355   
               
               
                 R 5  = R A1 , R 1  = R B4 , L A356   
               
               
                 R 5  = R A2 , R 1  = R B4 , L A357   
               
               
                 R 5  = R A3 , R 1  = R B4 , L A358   
               
               
                 R 5  = R A4 , R 1  = R B4 , L A359   
               
               
                 R 5  = R A5 , R 1  = R B4 , L A360   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 2  = R A1 , R 1  = R B3 , L A361   
               
               
                 R 2  = R A2 , R 1  = R B3 , L A362   
               
               
                 R 2  = R A3 , R 1  = R B3 , L A363   
               
               
                 R 2  = R A4 , R 1  = R B3 , L A364   
               
               
                 R 2  = R A5 , R 1  = R B3 , L A365   
               
               
                 R 2  = R A1 , R 1  = R B4 , L A366   
               
               
                 R 2  = R A2 , R 1  = R B4 , L A367   
               
               
                 R 2  = R A3 , R 1  = R B4 , L A368   
               
               
                 R 2  = R A4 , R 1  = R B4 , L A369   
               
               
                 R 2  = R A5 , R 1  = R B4 , L A370   
               
               
                   
               
               
                 
                   
                             
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                 R 3  = R A1 , R 1  = R B3 , L A371   
               
               
                 R 3  = R A2 , R 1  = R B3 , L A372   
               
               
                 R 3  = R A3 , R 1  = R B3 , L A373   
               
               
                 R 3  = R A4 , R 1  = R B3 , L A374   
               
               
                 R 3  = R A5 , R 1  = R B3 , L A375   
               
               
                 R 3  = R A1 , R 1  = R B4 , L A376   
               
               
                 R 3  = R A2 , R 1  = R B4 , L A377   
               
               
                 R 3  = R A3 , R 1  = R B4 , L A378   
               
               
                 R 3  = R A4 , R 1  = R B4 , L A379   
               
               
                 R 3  = R A5 , R 1  = R B4 , L A380 ; 
               
               
                   
               
             
          
         
       
     
         [0105]    wherein R A1  to R A5 , and R B1  to R B4  have the following structures: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0106]    In another embodiment, the compound is selected from the group consisting of Compound 1 through Compound 4940; wherein Compound x has the formula M(L Ai ) 2 (L Cj ); 
         [0107]    wherein x=380j+i−380, i is an integer from 1 to 380, and j is an integer from 1 to 13; and 
         [0108]    wherein L Cj  has the following formula: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0109]    In one embodiment, the compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature. In one embodiment, the compound is capable of functioning as a fluorescent emitter in an organic light emitting device at room temperature. In one embodiment, the compound is capable of functioning as a delayed fluorescent emitter in an organic light emitting device at room temperature. In one embodiment, the first compound is capable of emitting light from a triplet excited state to a ground singlet state at room temperature. 
         [0110]    In some embodiments, the compound can be an emissive dopant. In some embodiments, the compound can produce emissions via phosphorescence, fluorescence, thermally activated delayed fluorescence, i.e., TADF (also referred to as E-type delayed fluorescence), triplet-triplet annihilation, or combinations of these processes. 
         [0111]    According to another aspect of the present disclosure, an OLED is also provided. The OLED includes an anode, a cathode, and an organic layer disposed between the anode and the cathode. The organic layer may include a host and a phosphorescent dopant. The organic layer can include a compound of the invention and its variations as described herein. 
         [0112]    The OLED can be incorporated into one or more of a consumer product, an electronic component module, and a lighting panel. The organic layer can be an emissive layer and the first compound can be an emissive dopant in some embodiments, while the first compound can be a non-emissive dopant in other embodiments. 
         [0113]    According to another aspect of the present disclosure, a consumer product comprising an OLED is provided. The OLED may include an anode, a cathode, and an organic layer disposed between the anode and the cathode. The organic layer may include a host and one or more emitter dopants. In one embodiment, the organic layer includes a first compound. 
         [0114]    Non-limiting examples of consumer products include flat panel displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior illumination and/or signaling, heads-up displays, fully or partially transparent displays, flexible displays, laser printers, telephones, cell phones, tablets, phablets, personal digital assistants (PDAs), wearable device, laptop computers, digital cameras, camcorders, viewfinders, micro-displays, 3-D displays that are less than 2 inches diagonal, 3-D displays, virtual reality or augmented reality displays, vehicles, video walls comprising multiple displays tiled together, theater or stadium screens, and/or signs. 
         [0115]    The organic layer can also include a host. In some embodiments, two or more hosts are preferred. In some embodiments, the hosts used maybe a) bipolar, b) electron transporting, c) hole transporting or d) wide band gap materials that play little role in charge transport. In some embodiments, the host can include a metal complex. The host can be a triphenylene containing benzo-fused thiophene or benzo-fused furan. Any substituent in the host can be an unfused substituent independently selected from the group consisting of C n H 2n+1 , OC n H 2n+1 , OAr 1 , N(C n H 2n+1 ) 2 , N(Ar 1 )(Ar 2 ), CH═CH—C n H 2n+1 , C≡C—C n H 2n+1 , Ar 1 , Ar 1 —Ar 2 , and C n H 2n —Ar 1 , or the host has no substitution. In the preceding substituents n can range from 1 to 10; and Ar 1  and Ar 2  can be independently selected from the group consisting of benzene, biphenyl, naphthalene, triphenylene, carbazole, and heteroaromatic analogs thereof. The host can be an inorganic compound. For example, a Zn containing inorganic material e.g. ZnS. 
         [0116]    The host can be a compound comprising at least one chemical group selected from the group consisting of triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene. The host can include a metal complex. The host can be, but is not limited to, a specific compound selected from the group consisting of: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0000]    and combinations thereof.
 
Additional information on possible hosts is provided below.
 
         [0117]    In yet another aspect of the present disclosure, a formulation that comprises a compound of the invention is described. The formulation can include one or more components selected from the group consisting of a solvent, a host, a hole injection material, hole transport material, and an electron transport layer material, disclosed herein. 
         [0000]    Combination with Other Materials 
         [0118]    The materials described herein as useful for a particular layer in an organic light emitting device may be used in combination with a wide variety of other materials present in the device. For example, emissive dopants disclosed herein may be used in conjunction with a wide variety of hosts, transport layers, blocking layers, injection layers, electrodes and other layers that may be present. The materials described or referred to below are non-limiting examples of materials that may be useful in combination with the compounds disclosed herein, and one of skill in the art can readily consult the literature to identify other materials that may be useful in combination. 
       Conductivity Dopants: 
       [0119]    A charge transport layer can be doped with conductivity dopants to substantially alter its density of charge carriers, which will in turn alter its conductivity. The conductivity is increased by generating charge carriers in the matrix material, and depending on the type of dopant, a change in the Fermi level of the semiconductor may also be achieved. Hole-transporting layer can be doped by p-type conductivity dopants and n-type conductivity dopants are used in the electron-transporting layer. 
         [0120]    Non-limiting examples of the conductivity dopants that may be used in an OLED in combination with materials disclosed herein are exemplified below together with references that disclose those materials: EP01617493, EP01968131, EP2020694, EP2684932, US20050139810, US20070160905, US20090167167, US2010288362, WO06081780, WO2009003455, WO2009008277, WO2009011327, WO2014009310, US2007252140, US2015060804 and US2012146012. 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
       HIL/HTL: 
       [0121]    A hole injecting/transporting material to be used in the present invention is not particularly limited, and any compound may be used as long as the compound is typically used as a hole injecting/transporting material. Examples of the material include, but are not limited to: a phthalocyanine or porphyrin derivative; an aromatic amine derivative; an indolocarbazole derivative; a polymer containing fluorohydrocarbon; a polymer with conductivity dopants; a conducting polymer, such as PEDOT/PSS; a self-assembly monomer derived from compounds such as phosphoric acid and silane derivatives; a metal oxide derivative, such as MoO x ; a p-type semiconducting organic compound, such as 1,4,5,8,9,12-Hexaazatriphenylenehexacarbonitrile; a metal complex, and a cross-linkable compounds. 
         [0122]    Examples of aromatic amine derivatives used in HIL or HTL include, but not limit to the following general structures: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0123]    Each of Ar 1  to Ar 9  is selected from the group consisting of aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene; the group consisting of aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine; and the group consisting of 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group. Each Ar may be unsubstituted or may be substituted by a substituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof. 
         [0124]    In one aspect, Ar 1  to A 9  is independently selected from the group consisting of: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein k is an integer from 1 to 20; X 101  to X 108  is C (including CH) or N; Z 101  is NAr 1 , O, or S; Ar 1  has the same group defined above. 
         [0125]    Examples of metal complexes used in HIL or HTL include, but are not limited to the following general formula: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein Met is a metal, which can have 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 an ancillary ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal; and k′+k″ is the maximum number of ligands that may be attached to the metal. 
         [0126]    In one aspect, (Y 101 -Y 102 ) is a 2-phenylpyridine derivative. In another aspect, (Y 101 -Y 102 ) is a carbene ligand. In another aspect, Met is selected from Ir, Pt, Os, and Zn. In a further aspect, the metal complex has a smallest oxidation potential in solution vs. Fc + /Fc couple less than about 0.6 V. 
         [0127]    Non-limiting examples of the HIL and HTL materials that may be used in an OLED in combination with materials disclosed herein are exemplified below together with references that disclose those materials: CN102702075, DE102012005215, EP01624500, EP01698613, EP01806334, EP01930964, EP01972613, EP01997799, EP02011790, EP02055700, EP02055701, EP1725079, EP2085382, EP2660300, EP650955, JP07-073529, JP2005112765, JP2007091719, JP2008021687, JP2014-009196, KR20110088898, KR20130077473, TW201139402, U.S. Ser. No. 06/517,957, US20020158242, US20030162053, US20050123751, US20060182993, US20060240279, US20070145888, US20070181874, US20070278938, US20080014464, US20080091025, US20080106190, US20080124572, US20080145707, US20080220265, US20080233434, US20080303417, US2008107919, US20090115320, US20090167161, US2009066235, US2011007385, US20110163302, US2011240968, US2011278551, US2012205642, US2013241401, US20140117329, US2014183517, U.S. Pat. No. 5,061,569, U.S. Pat. No. 5,639,914, WO05075451, WO07125714, WO08023550, WO08023759, WO2009145016, WO2010061824, WO2011075644, WO2012177006, WO2013018530, WO2013039073, WO2013087142, WO2013118812, WO2013120577, WO2013157367, WO2013175747, WO2014002873, WO2014015935, WO2014015937, WO2014030872, WO2014030921, WO2014034791, WO2014104514, WO2014157018. 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
       EBL: 
       [0128]    An electron blocking layer (EBL) may be used to reduce the number of electrons and/or excitons that leave the emissive layer. The presence of such a blocking layer in a device may result in substantially higher efficiencies, and or longer lifetime, as compared to a similar device lacking a blocking layer. Also, a blocking layer may be used to confine emission to a desired region of an OLED. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and/or higher triplet energy than the emitter closest to the EBL interface. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and or higher triplet energy than one or more of the hosts closest to the EBL interface. In one aspect, the compound used in EBL contains the same molecule or the same functional groups used as one of the hosts described below. 
       Host: 
       [0129]    The light emitting layer of the organic EL device of the present invention preferably contains at least a metal complex as light emitting material, and may contain a host material using the metal complex as a dopant material. Examples of the host material are not particularly limited, and any metal complexes or organic compounds may be used as long as the triplet energy of the host is larger than that of the dopant. Any host material may be used with any dopant so long as the triplet criteria is satisfied. 
         [0130]    Examples of metal complexes used as host are preferred to have the following general formula: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein Met is a metal; (Y 103 -Y 104 ) is a bidentate ligand, Y 103  and Y 104  are independently selected from C, N, O, P, and S; L 101  is an another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal; and k′+k″ is the maximum number of ligands that may be attached to the metal. 
         [0131]    In one aspect, the metal complexes are: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein (O—N) is a bidentate ligand, having metal coordinated to atoms O and N. 
         [0132]    In another aspect, Met is selected from Ir and Pt. In a further aspect, (Y 103 -Y 104 ) is a carbene ligand. 
         [0133]    Examples of other organic compounds used as host are selected from the group consisting of aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene; the group consisting of aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine; and the group consisting of 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group. Each option within each group may be unsubstituted or may be substituted by a substituent selected from the group consisting of deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof. 
         [0134]    In one aspect, the host compound contains at least one of the following groups in the molecule: 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
         [0000]    wherein each of R 101  to R 107  is independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof, and when it is aryl or heteroaryl, it has the similar definition as Ar&#39;s mentioned above. k is an integer from 0 to 20 or 1 to 20; k″ is an integer from 0 to 20. X 101  to X 108  is selected from C (including CH) or N. Z 101  and Z 102  is selected from NR 101 , O, or S. 
         [0135]    Non-limiting examples of the host materials that may be used in an OLED in combination with materials disclosed herein are exemplified below together with references that disclose those materials: EP2034538, EP2034538A, EP2757608, JP2007254297, KR20100079458, KR20120088644, KR20120129733, KR20130115564, TW201329200, US20030175553, US20050238919, US20060280965, US20090017330, US20090030202, US20090167162, US20090302743, US20090309488, US20100012931, US20100084966, US20100187984, US2010187984, US2012075273, US2012126221, US2013009543, US2013105787, US2013175519, US2014001446, US20140183503, US20140225088, US2014034914, U.S. Pat. No. 7,154,114, WO2001039234, WO2004093207, WO2005014551, WO2005089025, WO2006072002, WO2006114966, WO2007063754, WO2008056746, WO2009003898, WO2009021126, WO2009063833, WO2009066778, WO2009066779, WO2009086028, WO2010056066, WO2010107244, WO2011081423, WO2011081431, WO2011086863, WO2012128298, WO2012133644, WO2012133649, WO2013024872, WO2013035275, WO2013081315, WO2013191404, WO2014142472, 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
       Additional Emitters: 
       [0136]    One or more additional emitter dopants may be used in conjunction with the compound of the present disclosure. Examples of the additional emitter dopants are not particularly limited, and any compounds may be used as long as the compounds are typically used as emitter materials. Examples of suitable emitter materials include, but are not limited to, compounds which can produce emissions via phosphorescence, fluorescence, thermally activated delayed fluorescence, i.e., TADF (also referred to as E-type delayed fluorescence), triplet-triplet annihilation, or combinations of these processes. 
         [0137]    Non-limiting examples of the emitter materials that may be used in an OLED in combination with materials disclosed herein are exemplified below together with references that disclose those materials: CN103694277, CN1696137, EB01238981, EP01239526, EP01961743, EP1239526, EP1244155, EP1642951, EP1647554, EP1841834, EP1841834B, EP2062907, EP2730583, JP2012074444, JP2013110263, JP4478555, KR1020090133652, KR20120032054, KR20130043460, TW201332980, U.S. Ser. No. 06/699,599, U.S. Ser. No. 06/916,554, US20010019782, US20020034656, US20030068526, US20030072964, US20030138657, US20050123788, US20050244673, US2005123791, US2005260449, US20060008670, US20060065890, US20060127696, US20060134459, US20060134462, US20060202194, US20060251923, US20070034863, US20070087321, US20070103060, US20070111026, US20070190359, US20070231600, US2007034863, US2007104979, US2007104980, US2007138437, US2007224450, US2007278936, US20080020237, US20080233410, US20080261076, US20080297033, US200805851, US2008161567, US2008210930, US20090039776, US20090108737, US20090115322, US20090179555, US2009085476, US2009104472, US20100090591, US20100148663, US20100244004, US20100295032, US2010102716, US2010105902, US2010244004, US2010270916, US20110057559, US20110108822, US20110204333, US2011215710, US2011227049, US2011285275, US2012292601, US20130146848, US2013033172, US2013165653, US2013181190, US2013334521, US20140246656, US2014103305, U.S. Pat. No. 6,303,238, U.S. Pat. No. 6,413,656, U.S. Pat. No. 6,653,654, U.S. Pat. No. 6,670,645, U.S. Pat. No. 6,687,266, U.S. Pat. No. 6,835,469, U.S. Pat. No. 6,921,915, U.S. Pat. No. 7,279,704, U.S. Pat. No. 7,332,232, U.S. Pat. No. 7,378,162, U.S. Pat. No. 7,534,505, U.S. Pat. No. 7,675,228, U.S. Pat. No. 7,728,137, U.S. Pat. No. 7,740,957, U.S. Pat. No. 7,759,489, U.S. Pat. No. 7,951,947, U.S. Pat. No. 8,067,099, U.S. Pat. No. 8,592,586, U.S. Pat. No. 8,871,361, WO06081973, WO06121811, WO07018067, WO07108362, WO07115970, WO07115981, WO08035571, WO2002015645, WO2003040257, WO2005019373, WO2006056418, WO2008054584, WO2008078800, WO2008096609, WO2008101842, WO2009000673, WO2009050281, WO2009100991, WO2010028151, WO2010054731, WO2010086089, WO2010118029, WO2011044988, WO2011051404, WO2011107491, WO2012020327, WO2012163471, WO2013094620, WO2013107487, WO2013174471, WO2014007565, WO2014008982, WO2014023377, WO2014024131, WO2014031977, WO2014038456, WO2014112450. 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
       HBL: 
       [0138]    A hole blocking layer (HBL) may be used to reduce the number of holes and/or excitons that leave the emissive layer. The presence of such a blocking layer in a device may result in substantially higher efficiencies and/or longer lifetime as compared to a similar device lacking a blocking layer. Also, a blocking layer may be used to confine emission to a desired region of an OLED. In some embodiments, the HBL material has a lower HOMO (further from the vacuum level) and or higher triplet energy than the emitter closest to the HBL interface. In some embodiments, the HBL material has a lower HOMO (further from the vacuum level) and or higher triplet energy than one or more of the hosts closest to the HBL interface. 
         [0139]    In one aspect, compound used in HBL contains the same molecule or the same functional groups used as host described above. 
         [0140]    In another aspect, compound used in HBL contains at least one of the following groups in the molecule: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein k is an integer from 1 to 20; L 101  is an another ligand, k′ is an integer from 1 to 3. 
       ETL: 
       [0141]    Electron transport layer (ETL) may include a material capable of transporting electrons. Electron transport layer may be intrinsic (undoped), or doped. Doping may be used to enhance conductivity. Examples of the En material are not particularly limited, and any metal complexes or organic compounds may be used as long as they are typically used to transport electrons. 
         [0142]    In one aspect, compound used in ETL contains at least one of the following groups in the molecule: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein R 101  is selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, myloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteromyl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof, when it is aryl or heteroaryl, it has the similar definition as Ar&#39;s mentioned above. Ar 1  to A 3  has the similar definition as Ar&#39;s mentioned above. k is an integer from 1 to 20. X 101  to X 108  is selected from C (including CH) or N. 
         [0143]    In another aspect, the metal complexes used in ETL contains, but not limit to the following general formula: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein (O—N) or (N—N) is a bidentate ligand, having 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 may be attached to the metal. 
         [0144]    Non-limiting examples of the ETL materials that may be used in an OLED in combination with materials disclosed herein are exemplified below together with references that disclose those materials: CN103508940, EP01602648, EP01734038, EP01956007, JP2004-022334, JP2005149918, JP2005-268199, KR0117693, KR20130108183, US20040036077, US20070104977, US2007018155, US20090101870, US20090115316, US20090140637, US20090179554, US2009218940, US2010108990, US2011156017, US2011210320, US2012193612, US2012214993, US2014014925, US2014014927, US20140284580, U.S. Pat. No. 6,656,612, U.S. Pat. No. 8,415,031, WO2003060956, WO2007111263, WO2009148269, WO2010067894, WO2010072300, WO2011074770, WO2011105373, WO2013079217, WO2013145667, WO2013180376, WO2014104499, WO2014104535, 
         [0000]    
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
       
                 
         
             
             
         
       
     
       Charge Generation Layer (CGL) 
       [0145]    In tandem or stacked OLEDs, the CGL plays an essential role in the performance, which is composed of an n-doped layer and a p-doped layer for injection of electrons and holes, respectively. Electrons and holes are supplied from the CGL and electrodes. The consumed electrons and holes in the CGL are refilled by the electrons and holes injected from the cathode and anode, respectively; then, the bipolar currents reach a steady state gradually. Typical CGL materials include n and p conductivity dopants used in the transport layers. 
         [0146]    In any above-mentioned compounds used in each layer of the OLED device, the hydrogen atoms can be partially or fully deuterated. Thus, any specifically listed substituent, such as, without limitation, methyl, phenyl, pyridyl, etc. may be undeuterated, partially deuterated, and fully deuterated versions thereof. Similarly, classes of substituents such as, without limitation, alkyl, aryl, cycloalkyl, heteroaryl, etc. also may be undeuterated, partially deuterated, and fully deuterated versions thereof. 
       EXPERIMENTAL 
       [0147]    
       
                 
         
             
             
         
       
     
         [0148]    A 2-neck 500 Ml round bottom flask with an addition funnel was dried under vacuum and charged with THF (270 mL), 1,1-dimethylsiletane (13.6 g, 136 mmol), diiodomethane (14.6 mL, 181 mmol) and cooled to −78° C. Freshly prepared lithium diisopropylamide solution in THF (280 mL, 181 mmol) was added dropwise via addition funnel. Once the addition was complete, the yellow/brown suspension was allowed to stir at −78° C. for 30 minutes, then allowed to warm to room temperature overnight. The reaction solution was poured into ˜200 mL sat. aq. NH 4 Cl and extracted with EtOAc. The organic layer was washed with brine, dried over sodium sulfate, filtered and concentrated to a brown oil. The crude product was purified by column chromatography in 100% heptanes, providing 27 g (83% yield) of the desired product as a clear, colorless oil. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0149]    Zinc (3.81 g, 58.3 mmol) and lithium chloride (2.47 g, 58.3 mmol) were dried under vacuum and cooled to room temperature. The reagents were suspended in THF (120 mL) and treated with 1,2-dibromoethane (0.93 ml, 10.78 mmol). The mixture was heated to 75° C. for 30 minutes, then cooled to room temperature. A solution of diiodine (0.74 g, 2.91 mmol) and chlorotrimethylsilane (1.12 mL, 8.74 mmol) in THF (13.3 mL) was added and the reaction was heated to 60° C. for 30 minutes. Upon cooling to room temperature, 2-iodo-1,1-dimethylsilolane (7.00 g, 29.1 mmol) was added via syringe and the reaction was heated at 50° C. overnight. The hazy, gray solution was used without purification. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0150]    A 500 mL round bottom flask was charged with 5-chloro-2-(3,5-dimethylphenyl)quinoline (5.00 g, 18.7 mmol), diacetoxypalladium (0.168 g, 0.747 mmol), 2′-(dicyclohexylphosphanyl)-N 2 ,N 2 ,N 6 ,N 6 -tetramethyl-[1,1′-biphenyl]-2,6-diamine (0.65 g, 1.49 mmol), and THF (190 mL) and degassed with nitrogen. (1,1-dimethylsilolan-2-yl)zinc(II) iodide (140 mL, 28.0 mmol) was added via syringe and the reaction was stirred at room temperature for 16 hours. The reaction was diluted with EtOAc, washed with sat. aq. NaHCO 3  and brine, dried over sodium sulfate filtered and concentrated. The product was purified by column chromatography in 50-75% DCM/heptanes. The pure fractions were combined and concentrated to 4.00 g of viscous oil. Further purification was achieved by reverse phase column chromatography in 90-100% CH 3 CN/H 2 O, followed by recrystallization from MeOH, providing 2.00 g (31% yield) of the title compound as a colorless, viscous oil. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0151]    A 500 mL 2-neck round bottom flask was charged with magnesium (10.15 g, 418 mmol) and dried under vacuum. 10 mL of diethyl ether was added, followed by a dropwise addition of bromoethane (28.3 mL, 380 mmol) until initiation was observed. The remaining diethyl ether (190 ml) was added and the remaining bromoethane (28.3 mL, 380 mmol) was added dropwise at a rate to maintain reflux. Once the addition was complete, the reaction was allowed to stir at room temperature for ˜30 minutes. The Grignard reagent was then added via cannula to a room temperature solution of 1,1-dichlorosiletane (15.0 mL, 127 mmol) in diethyl ether (127 mL) at a rate to maintain gentle reflux. The reaction solution was then allowed to stir at room temperature for 48 hours. The reaction solution was cooled in an ice bath and quenched cautiously with sat. aq. NH 4 Cl. The organic layer was extracted with ether, washed with brine, and dried over MgSO 4 . The organics were concentrated to a pale yellow oil. 10.6 g (65% yield) obtained as pale, yellow liquid and used without further purification. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0152]    A dry 500 mL round bottom flask was charged with anhydrous THF (166 mL), 1,1-diethylsiletane (10.6 g, 83.0 mmol), diiodomethane (8.9 mL, 111 mmol) and cooled to −78° C. Lithium diisopropylamide (170 mL, 111 mmol) was then added dropwise. The reaction was gradually warmed to room temperature and quenched by pouring into sat. aq. NH 4 Cl and extracted with ether. The organic layer was washed with brine, dried over MgSO 4 , filtered and concentrated. The crude product was purified by column chromatography in 100% heptanes. Fractions containing product were combined and concentrated to 18.0 g (81% yield) to provide a clear, colorless oil. The product was stored over copper wire. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0153]    Zinc (2.93 g, 44.7 mmol) and lithium chloride (1.90 g, 44.7 mmol) were dried under vacuum and cooled to room temperature. The reagents were suspended in THF (90 mL) and treated with 1,2-dibromoethane (0.71 mL, 8.28 mmol). The mixture was heated to 75° C. for 30 minutes, and then cooled to room temperature. A solution of diiodine (0.57 g, 2.24 mmol) and chlorotrimethylsilane (0.86 mL, 6.71 mmol) in THF (10.2 mL) was added and the reaction was heated to 60° C. for 30 minutes. After cooling to room temperature 1,1-diethyl-2-iodosilolane (6.00 g, 22.4 mmol) was added via syringe and the reaction was heated at 50° C. for 16 hrs. The hazy, gray solution was used without further purification. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0154]    A 100 mL round bottom flask was charged with 5-chloro-2-(3,5-dimethylphenyl)quinoline (3.20 g, 11.9 mmol), diacetoxypalladium (0.11 g, 0.48 mmol), 2′-(dicyclohexylphosphanyfi-N 2 ,N 2 ,N 6 ,N 6 -tetramethyl-[1,1′-biphenyl]-2,6-diamine (0.42 g, 0.96 mmol), and THF (120 mL) and degassed with nitrogen. (1,1-diethylsilolan-2-yl)zinc(II) iodide (96 mL, 19.1 mmol) was added via syringe and the reaction was stirred at room temperature for 4 days. The reaction solution was washed with sat. aq. NaHCO 3  and brine, dried over sodium sulfate, filtered and concentrated. The crude product was purified by column chromatography in 3-5% EtOAc/heptanes. Further purification was achieved by reverse phase column chromatography in 90-100% acetonitrile/water, yielding 4.00 g (90% yield) of the desired compound as a pale yellow, viscous oil. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0155]    A dry 100 mL round bottom flask was charged with hexanes (35 mL) and diethyl ether (1.9 mL) and degassed with nitrogen. tert-butyllithium (6.6 mL, 11.2 mmol) was added and the reaction solution was cooled to −78° C. 1,1-diethyl-2-iodosilolane (1.00 g, 3.73 mmol) was added via syringe and the reaction was stirred for 10 minutes before quenching with a solution of oxirane in THF (2.5 mL, 7.5 mmol). The reaction was stirred for 10 minutes, then removed from the bath and allowed to warm gradually to room temperature before quenching with water. The reaction was extracted with EtOAc, washed with water, brine and dried over sodium sulfate. The organics were concentrated to an orange oil and purified by column chromatography in 5-20% EtOAc/heptanes, providing 0.50 g (72% yield) of the title compound as a clear, colorless oil. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0156]    Triphenylphosphane (3.74 g, 14.37 mmol) was dissolved in DCM (30 mL) and treated sequentially with 1H-imidazole (0.97 g, 14.27 mmol) and diiodine (3.62 g, 14.27 mmol) at room temperature. The yellow solution was stirred for 15 minutes at room temperature, and then treated with a solution of 2-(1,1-diethylsilolan-2-yl)ethan-1-ol (1.90 g, 10.19 mmol) in DCM (4.0 mL) and stirred at room temperature for 16 hours. The solvent was removed in vacuo and the crude orange product thus obtained was purified by vacuum distillation using a Kugelrohr, providing 1.60 g (53% yield) of the title compound as a clear, colorless oil. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0157]    Zinc (0.71 g, 10.80 mmol) and lithium chloride (0.46 g, 10.80 mmol) were dried under vacuum and cooled to room temperature. The reagents were suspended in THF (22.1 mL) and treated with 1,2-dibromoethane (0.17 mL, 2.00 mmol). The mixture was heated to 75° C. for 30 minutes, then cooled to room temperature. A solution of diiodine (0.14 g, 0.54 mmol) and chlorotrimethylsilane (0.21 mL, 1.62 mmol) in THF (2.6 mL) was added and the reaction was heated to 60° C. for 30 minutes. Upon cooling to room temperature, 1,1-diethyl-2-(2-iodoethyl)silolane (1.60 g, 5.40 mmol) was added via syringe and the reaction was heated at 50° C. for 16 hours. The hazy, gray solution was used without further purification. 
         [0000]    
       
                 
         
             
             
         
       
     
         [0158]    A 250 mL round bottom flask was charged with 5-chloro-2-(3,5-dimethylphenyl)quinoline (0.75 g, 2.80 mmol), diacetoxypalladium (0.025 g, 0.112 mmol), 2′-(dicyclohexylphosphanyl)-N 2 ,N 2 ,N 6 ,N 6 -tetramethyl-[1,1′-biphenyl]-2,6-diamine (0.098 g, 0.224 mmol), and THF (28 mL) and degassed with nitrogen. (2-(1,1-diethylsilolan-2-yl)ethyl)zinc(II) iodide (25 mL, 5.0 mmol) was added via syringe and the reaction was stirred at room temperature for 16 hours. The organics were washed with sat. aq. NaHCO 3  and brine, dried over sodium sulfate, filtered and concentrated. The crude product was purified by column chromatography in 2% EtOAc/heptanes, providing 0.80 g (71% yield) of the title compound as a viscous oil. 
         [0159]    All the above ligands may be complexated into Ir metal complexes following the standard procedure. A non-limiting example is shown below: 
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         [0160]    It is understood that the various embodiments described herein are by way of example only, and are not intended to limit the scope of the invention. For example, many of the materials and structures described herein may be substituted with other materials and structures without deviating from the spirit of the invention. The present invention as claimed may therefore include variations from the particular examples and preferred embodiments described herein, as will be apparent to one of skill in the art. It is understood that various theories as to why the invention works are not intended to be limiting.