Organometallic compound and organic light emitting diode comprising the same

Abstract

Disclosed is a novel organometallic compound in which a main ligand (L A ) has a fused ring structure including a thiophene group. The organometallic compound is used as a dopant for a phosphorescent light-emitting layer of an organic light-emitting diode. Thus, the operating voltage of the diode is reduced, and the light-emitting efficiency and the lifetime of the diode are improved.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0188299, filed on December 27, 2021, with the Korean Intellectual Property Office, and all benefits arising therefrom under 35U.SC119, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure relates to organometallic compounds, and more specifically, to organometallic compounds having phosphorescent properties and organic light-emitting diodes comprising such organometallic compounds. Background Technology

[0004] As display devices are applied in various fields, interest in them is increasing. One type of display device is the organic light-emitting display device, which includes the rapidly developing organic light-emitting diode (OLED).

[0005] In an organic light-emitting diode (OLED), when charge is injected into the light-emitting layer formed between the positive and negative electrodes, electrons and holes recombine in the light-emitting layer to form excitons, thus converting the energy of the excitons into light. This is how an OLED emits light. Compared to traditional display devices, OLEDs can operate at lower voltages, consume relatively less power, exhibit superior color, and can be used in a variety of ways due to the availability of flexible substrates. Furthermore, the size of an OLED can be freely adjusted. Summary of the Invention

[0006] Compared to liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs) offer superior viewing angles and contrast ratios. Furthermore, because OLEDs do not require backlighting, they are lightweight and ultra-thin. An OLED comprises multiple organic layers between a negative electrode (electron injection electrode; cathode) and a positive electrode (hole injection electrode; anode). These multiple organic layers may include a hole injection layer, a hole transport layer, a hole transport assist layer, an electron blocking layer, and light-emitting layers, electron transport layers, etc.

[0007] In this organic light-emitting diode structure, when a voltage is applied between the two electrodes, electrons and holes are injected into the light-emitting layer from the negative and positive electrodes, respectively, thereby generating excitons in the light-emitting layer, which then descend to the ground state and emit light.

[0008] Organic materials used in organic light-emitting diodes (OLEDs) can be mainly divided into luminescent materials and charge-transport materials. The luminescent material is a crucial factor determining the luminous efficiency of an OLED. Luminescent materials possess high quantum efficiency, excellent electron and hole mobility, and exist uniformly and stably within the luminescent layer. Based on the color of light emitted, luminescent materials can be categorized into those emitting blue, red, and green light. Color-generating materials may include a host and dopants to improve color purity and luminous efficiency through energy transfer.

[0009] In recent years, there has been a trend towards using phosphorescent materials instead of fluorescent materials for the luminescent layer. When fluorescent materials are used, approximately 25% of the singlet states, which are excitons generated in the luminescent layer, are used for luminescence, while the majority of the 75% of the triplet states are dissipated as heat. However, when phosphorescent materials are used, both singlet and triplet states are used for luminescence.

[0010] Organometallic compounds are typically used as phosphorescent materials in organic light-emitting diodes (OLEDs). Continued research and development of phosphorescent materials is needed to address issues of low efficiency and lifespan.

[0011] Therefore, the object of the present invention is to provide an organometallic compound that can reduce operating voltage and improve efficiency and lifespan, and an organic light-emitting diode comprising an organic light-emitting layer containing the organometallic compound.

[0012] The purpose of this disclosure is not limited to the objectives described above. Other objectives and advantages not mentioned in this disclosure may be understood based on the following description and may be more clearly understood based on exemplary embodiments of this disclosure. Furthermore, it will be readily understood that the objectives and advantages of this disclosure can be achieved using the means set forth in the claims and combinations thereof.

[0013] To achieve the above objectives, this disclosure provides an organometallic compound having a novel structure represented by the following chemical formula 1, an organic light-emitting diode (OLED) wherein the light-emitting layer comprises the organometallic compound as a dopant, and an organic light-emitting display device including the organic light-emitting diode:

[0014] Ir(L A ) m (L B ) n (Chemical Formula 1)

[0015] In chemical formula 1,

[0016] L A It can be represented by one of the groups selected from the following chemical formulas 2-1 to 2-6.

[0017] L BIt can be a bidentate ligand represented by the following chemical formula 3.

[0018] m can be 1, 2, or 3, n can be 0, 1, or 2, and the sum of m and n can be 3.

[0019]

[0020]

[0021] In each of chemical formulas 2-1 to 2-6

[0022] X can represent one of the groups consisting of -CH2-, -NH-, oxygen, and sulfur.

[0023] R 1-1 R 1-2 R 2-1 R 2-2 R 3-1 R 3-2 R 3-3 R 4-1 and R 4-2 Each of these can independently represent one selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, thioalkyl, sulfinyl, sulfonyl, phosphinyl, and combinations thereof.

[0024] Optional, R 1-1 R 1-2 R 2-1 R 2-2 R 3-1 R 3-2 R 3-3 R 4-1 and R 4-2 Two adjacent functional groups can combine to form a ring structure.

[0025] Organometallic compounds according to exemplary embodiments of this disclosure can be used as dopants in the phosphorescent layer of organic light-emitting diodes (OLEDs), thereby reducing the operating voltage of OLEDs and improving their efficiency and lifetime characteristics.

[0026] The effects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand other effects not mentioned through the following description.

[0027] It should be understood that the foregoing general description and the following detailed description of this disclosure are exemplary and explanatory, and are intended to provide further explanation of the claimed inventive concept. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of this disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure.

[0029] Figure 1 This is a schematic cross-sectional view of an organic light-emitting diode in which the light-emitting layer comprises an organometallic compound, according to an illustrative embodiment of the present disclosure.

[0030] Figure 2 This is a schematic cross-sectional view of an organic light-emitting diode having a series structure according to an illustrative embodiment of the present disclosure, the series structure having two light-emitting stacks and comprising an organometallic compound represented by chemical formula 1.

[0031] Figure 3 This is a schematic cross-sectional view of an organic light-emitting diode having a series structure according to an illustrative embodiment of the present disclosure, the series structure having three light-emitting stacks and comprising an organometallic compound represented by chemical formula 1.

[0032] Figure 4 This is a schematic cross-sectional view of an organic light-emitting display device including an organic light-emitting diode according to an illustrative embodiment of the present disclosure. Detailed Implementation

[0033] The advantages and features of this disclosure, as well as methods for achieving these advantages and features, will become apparent from the exemplary embodiments described in detail below with reference to the accompanying drawings. However, this disclosure is not limited to the exemplary embodiments disclosed below, but can be implemented in various different forms. Therefore, these exemplary embodiments are set forth only to complete this disclosure and to fully inform those skilled in the art of the scope of this disclosure, which is limited only by the scope of the claims.

[0034] The shapes, dimensions, ratios, angles, quantities, etc., disclosed in the accompanying drawings used to describe exemplary embodiments of this disclosure are illustrative and the disclosure is not limited thereto. The same reference numerals refer to the same elements herein. Furthermore, for the sake of simplicity, descriptions and details of well-known steps and elements have been omitted. In addition, numerous specific details are set forth in the following detailed description of this disclosure to provide a thorough understanding of it. However, it should be understood that this disclosure can be practiced without these specific details. In other instances, well-known methods, processes, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of this disclosure.

[0035] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this disclosure. As used herein, the singular constructs “a” and “an” are also intended to include the plural constructs, unless the context clearly indicates otherwise. It should also be understood that, when used in this specification, the terms “comprising,” “including,” “comprises,” and “including” specify the presence of the stated features, integers, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, operations, elements, components, and / or portions thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. When preceding a list of elements, expressions such as “at least one” may modify the entire list of elements and may not modify individual elements of the list. In the interpretation of numerical values, errors or tolerances may occur even if not explicitly described.

[0036] Furthermore, it should be understood that when a first element or layer is referred to as existing “on” a second element or layer, the first element may be directly disposed on the second element or may be indirectly disposed on the second element by a third element or layer disposed between the first and second elements or layers. It should be understood that when an element or layer is referred to as being “connected to” or “coupled to” another element or layer, it may be directly connected to or coupled to another element or layer, or one or more intermediate elements or layers may exist. Furthermore, it should be understood that when an element or layer is referred to as being “between” two elements or layers, it may be the only element or layer between the two elements or layers, or one or more intermediate elements or layers may also exist.

[0037] Furthermore, as used herein, when a layer, membrane, region, plate, etc., is disposed "on" or "on top" of another layer, membrane, region, plate, etc., the former can directly contact the latter, or another layer, membrane, region, plate, etc., can be disposed between the former and the latter. As used herein, when a layer, membrane, region, plate, etc., is directly disposed "on" or "on top" of another layer, membrane, region, plate, etc., the former directly contacts the latter, and no other layer, membrane, region, plate, etc., is disposed between the former and the latter. Furthermore, as used herein, when a layer, membrane, region, plate, etc., is disposed "below" or "under" another layer, membrane, region, plate, etc., the former can directly contact the latter, or another layer, membrane, region, plate, etc., can be disposed between the former and the latter. As used herein, when a layer, membrane, region, plate, etc., is directly disposed "below" or "under" another layer, membrane, region, plate, etc., the former directly contacts the latter, and no other layer, membrane, region, plate, etc., is disposed between the former and the latter.

[0038] In descriptions of temporal relationships, such as the temporal precedence between two events as "after," "following," or "before," another event may occur between the two events unless it is specified that "immediately after," "immediately following," or "immediately before."

[0039] It should be understood that although the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or part from another. Therefore, without departing from the spirit and scope of this disclosure, the first element, component, region, layer, or part described below may be referred to as the second element, component, region, layer, or part.

[0040] The features of the various embodiments of this disclosure can be combined in whole or in part with each other, and can be technically related to or interoperable with each other. The exemplary embodiments of this disclosure can be implemented independently of each other, or they can be implemented together in a related relationship.

[0041] When interpreting numerical values, unless otherwise explicitly described, the value is interpreted to include a range of error.

[0042] Unless otherwise defined, all terms used herein, including technical and scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concept pertains. It should also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having the same meaning as their meaning in the context of the relevant field, and shall not be interpreted as having an idealized or overly formal meaning, unless expressly defined herein.

[0043] As used herein, the phrase "adjacent functional groups combine to form a ring structure" means that adjacent functional groups can combine to form a substituted or unsubstituted alicyclic structure (cycloalkyl), a substituted or unsubstituted aromatic ring structure (aryl), or a ring structure having both substituted or unsubstituted alicyclic and aromatic rings (alkylaryl or arylalkyl). For a specific functional group, the phrase "adjacent functional group" can refer to the functional group that substitutes an atom directly bonded to the atom substituted by that specific functional group, the functional group spatially closest to that specific functional group, or the functional group that substitutes an atom substituted by that specific functional group. For example, two adjacent functional groups in a substituted benzene ring structure and two functional groups on the same carbon atom in a substituted alicyclic ring can be interpreted as "adjacent functional groups".

[0044] As used herein, unless otherwise stated, the term "substituted" means that the specified group or portion has one or more substituents. The term "unsubstituted" means that the specified group has no substituents.

[0045] As used herein and unless otherwise stated, the term "substituent" refers to a non-hydrogen moiety, such as deuterium, hydroxyl, halogen (e.g., fluorine, chlorine, or bromine), carboxyl, formamide, imino, alkyl, cyano, cyanomethyl, nitro, amino, alkyl, alkenyl, alkynyl, cycloalkyl, arylalkyl, aryl, heterocyclic, heteroaryl, hydroxyl, alkoxy, alkoxycarbonyl, monoalkylaminosulfinyl, dialkylaminosulfinyl, monoalkylaminosulfonyl, dialkylaminosulfonyl, alkylsulfonylamino, hydroxysulfonyloxy, alkoxysulfonyloxy, alkylsulfonyloxy, hydroxysulfonyl, alkoxysulfonyl, alkylsulfonylalkyl, monoalkylaminosulfonylalkyl, dialkylaminosulfonylalkyl, monoalkylaminosulfinylalkyl, dialkylaminosulfinylalkyl, and the like.

[0046] As used herein, unless otherwise stated, the term "alkyl" refers to a substituted or unsubstituted, saturated, straight-chain or branched hydrocarbon chain radical. Examples of alkyl groups include, but are not limited to, C1-C15 straight-chain, branched, or cyclic alkyl groups, such as methyl, ethyl, propyl, isopropyl, cyclopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, pentyl, isopentyl, neopentyl, hexyl, and cyclohexyl; and longer alkyl groups, such as heptyl, octyl, nonyl, and decyl. The alkyl group can be unsubstituted or substituted with one or two suitable substituents.

[0047] As used herein, unless otherwise stated, the term "cycloalkyl" refers to a monocyclic or polycyclic saturated ring containing carbon and hydrogen atoms and without carbon-carbon multiple bonds. Cycloalkyl groups can be unsubstituted or substituted. Examples of cycloalkyl groups include, but are not limited to, (C3-C7) cycloalkyl groups, including cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl, as well as saturated cyclic and bicyclic terpenes. Cycloalkyl groups can be unsubstituted or substituted. Preferably, the cycloalkyl group is monocyclic or bicyclic.

[0048] As used herein, unless otherwise stated, the term "aryl" refers to a monocyclic or polycyclic conjugated ring structure known in the art. Examples of suitable aryl or aromatic rings include, but are not limited to, phenyl, tolyl, anthracel, fluorenyl, indene, azulel, and naphthyl. The aryl group may be unsubstituted or substituted with one or two suitable substituents.

[0049] As used herein, unless otherwise stated, the term "substituted aryl" includes aryl groups optionally substituted with one or more of the following functional groups: such as halogen, alkyl, haloalkyl (e.g., trifluoromethyl), alkoxy, haloalkoxy (e.g., difluoromethoxy), alkenyl, alkynyl, aryl, heteroaryl, aralkyl, aryloxy, aryloxyalkyl, arylalkoxy, alkoxycarbonyl, alkylcarbonyl, arylcarbonyl, arylalenyl, aminocarbonylaryl, arylthio, arylsulfinyl, arylazo, heteroarylalkyl, heteroarylalenyl, heteroaryloxy, hydroxyl, nitrate The amino group includes alkyl, cyano, amino, substituted amino (wherein the amino group comprises one or two substituents (optionally substituted alkyl, aryl, or any other substituent described herein)), thiol, alkylthio, arylthio, heteroarylthio, arylthioalkyl, alkoxyarylthio, alkylaminocarbonyl, arylaminocarbonyl, aminocarbonyl, alkylcarbonyloxy, arylcarbonyloxy, alkylcarbonylamino, arylcarbonylamino, arylsulfinyl, arylsulfinylalkyl, arylsulfonylamino, or arylsulfonylaminocarbonyl, and / or any alkyl substituent described herein.

[0050] As used herein, unless otherwise stated, the term "heteroaryl" as used alone or as part of another group refers to a 5- to 7-membered aromatic ring comprising 1, 2, 3, or 4 heteroatoms (such as nitrogen, oxygen, or sulfur), and such rings fused with an aryl, cycloalkyl, heteroaryl, or heterocycloalkyl ring (e.g., benzothiophene, indole), and includes possible N-oxides. "Substituted heteroaryl" includes heteroaryls optionally substituted with 1 to 4 substituents (such as those included in the definitions of "substituted alkyl" and "substituted cycloalkyl" above). Substituted heteroaryls also include fused heteroaryls, including, for example, quinoline, isoquinoline, indole, isoindole, carbazole, acridine, benzimidazole, benzofuran, isobenzofuran, benzothiophene, phenanthroline, purine, and the like.

[0051] The structure and preparation examples of the organometallic compound according to this disclosure, as well as an organic light-emitting diode including the organometallic compound, will be described below.

[0052] Traditionally, organometallic compounds have been used as dopants in the light-emitting layer of organic light-emitting diodes (OLEDs). For example, structures such as 2-phenylpyridine or 2-phenylquinoline are known as host ligand structures for organometallic compounds. However, conventional light-emitting dopants have limitations in improving the efficiency and lifetime of OLEDs. Therefore, it is necessary to develop a new light-emitting doping material. Accordingly, the inventors of this disclosure have obtained a light-emitting doping material capable of further improving the efficiency and lifetime of OLEDs, thus completing this disclosure.

[0053] Specifically, an organometallic compound according to one embodiment of this disclosure can be represented by the following chemical formula 1. L, as the main ligand of chemical formula 1... A The structure comprises a thiophene containing sulfur (S) atoms, which is incorporated as a fused ring into a nitrogen (N) pyridine ring within two rings connected to Ir (iridium) as a central coordinating metal. Furthermore, based on the connection positions and orientations of the thiophene fused rings, the organometallic compound can be represented by one of the following chemical formulas 2-1 to 2-6. The inventors of this disclosure have experimentally discovered that when the organometallic compound represented by chemical formula 1 is used as a dopant material in the phosphorescent layer of an organic light-emitting diode (OLED), the luminous efficiency and lifetime of the OLED are improved, and its operating voltage is reduced, thus completing this disclosure.

[0054] Ir(L A ) m (L B ) n (Chemical Formula 1)

[0055] In chemical formula 1,

[0056] L A It can be represented by one of the groups selected from the following chemical formulas 2-1 to 2-6.

[0057] L B It can be a bidentate ligand represented by the following chemical formula 3.

[0058] m can be 1, 2, or 3, n can be 0, 1, or 2, and the sum of m and n can be 3.

[0059]

[0060]

[0061]

[0062] In each of chemical formulas 2-1 to 2-6

[0063] X can represent one of the groups consisting of -CH2-, -NH-, oxygen, and sulfur.

[0064] R 1-1 R 1-2 R 2-1 R 2-2 R 3-1 R 3-2 R 3-3 R 4-1 and R 4-2Each of these can independently represent one selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, thioalkyl, sulfinyl, sulfonyl, phosphinyl, and combinations thereof.

[0065] Optional, R 1-1 R 1-2 R 2-1 R 2-2 R 3-1 R 3-2 R 3-3 R 4-1 and R 4-2 Two adjacent functional groups can combine to form a ring structure.

[0066] In the organometallic compounds according to embodiments of the present disclosure, the auxiliary ligand bound to the central coordinating metal may be a bidentate ligand. The bidentate ligand may contain an electron donor, thereby increasing the amount of metal-to-ligand charge transfer (MLCT), thus enabling the organic light-emitting diode to exhibit improved luminescent properties, such as high luminous efficiency and high external quantum efficiency.

[0067] According to this disclosure, the preferred auxiliary ligand can be a bidentate ligand represented by chemical formula 3. Chemical formula 3 can be selected from one of the group consisting of chemical formulas 4 and 5:

[0068]

[0069] In chemical formula 4, R 5-1 R 5-2 R 5-3 R 5-4 R 6-1 R 6-2 R 6-3 and R 6-4 Each of these can independently represent one selected from the group consisting of hydrogen, deuterium, C1-C5 straight-chain alkyl, and C1-C5 branched alkyl, and optionally, R 5-1 R 5-2 R 5-3 R 5-4 R 6-1 R 6-2 R 6-3 and R 6-4 Two adjacent functional groups can combine to form a ring structure.

[0070] In chemical formula 5, each of R7, R8, and R9 can independently represent one selected from the group consisting of hydrogen, deuterium, C1-C5 straight-chain alkyl, and C1-C5 branched alkyl, and optionally, two adjacent functional groups of R7, R8, and R9 can combine with each other to form a ring structure.

[0071] The C1-C5 straight-chain alkyl or C1-C5 branched alkyl can be substituted by at least one of the elements selected from the group consisting of deuterium and halogens.

[0072] Organometallic compounds according to embodiments of this disclosure may have heterogamic or homogamic structures. For example, organometallic compounds according to embodiments of this disclosure may have: a heterogamic structure, wherein in chemical formula 1, m is 1 and n is 2; or a heterogamic structure, wherein in chemical formula 1, m is 2 and n is 1; or a homogamic structure, wherein in chemical formula 1, m is 3 and n is 0.

[0073] Specific examples of compounds represented by Chemical Formula 1 of this disclosure may include one selected from the group consisting of compounds 1 to 449. However, specific examples of compounds represented by Chemical Formula 1 of this disclosure are not limited thereto, as long as they satisfy the definition of Chemical Formula 1 above:

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087] According to one embodiment of the present disclosure, the organometallic compound represented by chemical formula 1 of the present disclosure can be used as a dopant material to achieve red phosphorescence or green phosphorescence, preferably as a dopant material to achieve green phosphorescence.

[0088] Reference Figure 1 According to one embodiment of this disclosure, an organic light-emitting diode (OLED) 100 may be provided, comprising: a first electrode 110; a second electrode 120 facing the first electrode 110; and an organic layer 130 disposed between the first electrode 110 and the second electrode 120. The organic layer 130 may include a light-emitting layer 160, and the light-emitting layer 160 may include a host material 160' and a dopant 160'. The dopant 160' may include an organometallic compound represented by chemical formula 1. Furthermore, in the OLED 100, the organic layer 130 disposed between the first electrode 110 and the second electrode 120 may be formed by sequentially stacking a hole injection layer 140 (HIL), a hole transport layer 150 (HTL), a light-emitting layer 160 (EML), an electron transport layer 170 (ETL), and an electron injection layer 180 (EIL) on the first electrode 110. The second electrode 120 may be formed on the electron injection layer 180, and a protective layer (not shown) may be formed on the second electrode 120.

[0089] Furthermore, despite Figure 1 As not shown, a hole transport auxiliary layer can be further added between the hole transport layer 150 and the emitting layer 160. The hole transport auxiliary layer may contain a compound with good hole transport properties and can reduce the difference between the HOMO energy levels of the hole transport layer 150 and the emitting layer 160, thereby adjusting the hole injection characteristics. Therefore, hole accumulation at the interface between the hole transport auxiliary layer and the emitting layer 160 can be reduced, thereby reducing the quenching phenomenon caused by exciton disappearance at the interface due to polarons. Thus, device degradation can be reduced and the device can be stabilized, thereby improving its efficiency and lifetime.

[0090] The first electrode 110 can be used as a positive electrode and may include ITO, IZO, tin oxide, or zinc oxide as a conductive material having a relatively large work function value. However, this disclosure is not limited thereto.

[0091] The second electrode 120 can be used as a negative electrode and may include Al, Mg, Ca, or Ag, or alloys or combinations thereof, as a conductive material having a relatively small work function value. However, this disclosure is not limited thereto.

[0092] The hole injection layer 140 may be located between the first electrode 110 and the hole transport layer 150. The hole injection layer 140 may have the function of improving the interface characteristics between the first electrode 110 and the hole transport layer 150, and may be selected from materials with appropriate conductivity. The hole injection layer 140 may include a compound selected from the group consisting of N1-phenyl-N4,N4-bis(4-(phenyl(tolyl)amino)phenyl)-N1-(tolyl)benzene-1,4-diamine (MTDATA), copper phthalocyanine (II) (CuPc), tris(4-carbazolyl-9-ylphenyl)amine (TCTA), 1,4,5,8,9,11-hexaazatriphenylenehexanitrile (HATCN), 1,3,5-tris[4-(diphenylamino)phenyl]benzene (TDAPB), poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT / PSS) and N1,N1'-([1,1'-biphenyl]-4,4'-diyl)bis(N1,N4,N4-triphenylbenzene-1,4-diamine). Preferably, the hole injection layer 140 may include N1,N1'-([1,1'-biphenyl]-4,4'-diyl)bis(N1,N4,N4-triphenylphenyl-1,4-diamine). However, this disclosure is not limited thereto.

[0093] Hole transport layer 150 may be located near light-emitting layer 160 and between first electrode 110 and light-emitting layer 160. The material of hole transport layer 150 may include at least one compound selected from the group consisting of: N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine (TPD), N,N'-bis(1-naphthyl)-N,N'-biphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine, N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)biphenyl)-4-amine, etc. Preferably, the material of the hole transport layer 150 may include NPB. However, this disclosure is not limited thereto.

[0094] According to this disclosure, the light-emitting layer 160 can be formed by doping the host material 160' with an organometallic compound represented by chemical formula 1 as a dopant 160" to improve the luminous efficiency of the diode 100. The dopant 160" can be used as a green or red light-emitting material, and is preferably used as a green phosphorescent material.

[0095] Based on the total weight of the host material 160', the doping concentration of the dopant 160" according to the exemplary embodiments of this disclosure can be adjusted to a range of 1 wt% to 30 wt%. However, this disclosure is not limited thereto. For example, the doping concentration can be in the range of 2 wt% to 20 wt%, such as 3 wt% to 15 wt%, such as 5 wt% to 10 wt%, such as 3 wt% to 8 wt%, such as 2 wt% to 7 wt%, such as 5 wt% to 7 wt%, or such as 5 wt% to 6 wt%.

[0096] The luminescent layer 160 according to an exemplary embodiment of this disclosure comprises a host material 160' known in the art and capable of achieving the effects of this disclosure, while layer 160 comprises an organometallic compound represented by chemical formula 1 as a dopant 160'. For example, according to this disclosure, the host material 160' may comprise a compound containing a carbazole group, and may preferably comprise a host material selected from the group consisting of CBP (4,4'-bis(N-carbazole)-1,1'-biphenyl), mCP (1,3-bis(carbazole-9-yl)), and the like. However, this disclosure is not limited thereto.

[0097] Furthermore, the electron transport layer 170 and the electron injection layer 180 can be sequentially stacked between the light-emitting layer 160 and the second electrode 120. The material of the electron transport layer 170 needs to have high electron mobility so that electrons can be stably supplied to the light-emitting layer under smooth electron transport.

[0098] For example, the material of electron transport layer 170 may be known in the art and may include at least one compound selected from the group consisting of: tris(8-hydroxyquinoline)aluminum (Alq3), (8-hydroxyquinoline lithium) (Liq), (2-(4-biphenyl))-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), (3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole) (TAZ), spiro-PBD, (bis(2-methyl-8-quinoline acid)-4-(phenylphenol)aluminum) (BAlq), bis(2-methyl-8-hydroxyquinoline) The materials used include (triphenylsiloxy)aluminum (SA1q), (2,2',2-(1,3,5-phenyltriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi), oxadiazole, triazole, phenanthrene, benzoxazole, benzothiazole, and 2-(4-(9,10-bis(naphthyl-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzimidazole. Preferably, the material of the electron transport layer 170 may include 2-(4-(9,10-bis(naphthyl-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzimidazole. However, this disclosure is not limited thereto.

[0099] An electron injection layer 180 is used to facilitate electron injection. The material of the electron injection layer may be a compound known in the art and includes at least one compound selected from the group consisting of Alq3 (tris(8-hydroxyquinoline)aluminum), PBD, TAZ, spiro-PBD, BAlq, SAlq, etc. However, this disclosure is not limited thereto. Alternatively, the electron injection layer 180 may be made of a metal compound. The metal compound may include one or more selected from, for example, Liq, LiF, NaF, KF, RbF, CsF, FrF, BeF2, MgF2, CaF2, SrF2, BaF2, and RaF2. However, this disclosure is not limited thereto.

[0100] An organic light-emitting diode (OLED) according to an exemplary embodiment of this disclosure can be implemented as a white OLED with a series structure. A series OLED according to an illustrative embodiment of this disclosure can be formed as a structure in which adjacent light-emitting stacks of two or more light-emitting stacks are connected to each other via a charge-generating layer (CGL). The OLED may include at least two light-emitting stacks disposed on a substrate, each of the at least two light-emitting stacks including a first electrode and a second electrode facing each other, and a light-emitting layer disposed between the first electrode and the second electrode to emit light of a specific wavelength band. Multiple light-emitting stacks may emit light of the same color or different colors. Furthermore, one or more light-emitting layers may be included in a single light-emitting stack, and multiple light-emitting layers may emit light of the same color or different colors.

[0101] In this configuration, the light-emitting layer in at least one of the multiple light-emitting stacks may contain an organometallic compound represented by Formula 1 as a dopant, according to this disclosure. Adjacent light-emitting stacks in a tandem structure may be connected to each other via a charge-generating layer CGL comprising an N-type charge-generating layer and a P-type charge-generating layer.

[0102] Figure 2 and Figure 3 This is a schematic cross-sectional view of an organic light-emitting diode in a series structure having two light-emitting stacks and an organic light-emitting diode in a series structure having three light-emitting stacks, according to some embodiments of the present disclosure.

[0103] like Figure 2As shown, an organic light-emitting diode 100 according to an exemplary embodiment of the present disclosure includes a first electrode 110 and a second electrode 120 facing each other, and an organic layer 230 located between the first electrode 110 and the second electrode 120. The organic layer 230 may be located between the first electrode 110 and the second electrode 120 and may include a first light-emitting stack ST1 including a first light-emitting layer 261, a second light-emitting stack ST2 located between the first light-emitting stack ST1 and the second electrode 120 and including a second light-emitting layer 262, and a charge-generating layer CGL located between the first light-emitting stack ST1 and the second light-emitting stack ST2. The charge-generating layer CGL may include an N-type charge-generating layer 291 and a P-type charge-generating layer 292. At least one of the first light-emitting layer 261 and the second light-emitting layer 262 may contain an organometallic compound represented by Chemical Formula 1 according to the present disclosure as a dopant. For example, such as... Figure 2 As shown, the second light-emitting layer 262 of the second light-emitting stack ST2 may include a host material 262' and a dopant 262', comprising an organometallic compound represented by chemical formula 1. Although Figure 2 As not shown, in addition to each of the first light-emitting layer 261 and the second light-emitting layer 262, each of the first light-emitting stack ST1 and the second light-emitting stack ST2 may further include an additional light-emitting layer. In one embodiment, the first HTL 251 and the second HTL 252 may have the same characteristics as... Figure 1 The structure and materials are similar to or the same as those of HTL150. In one embodiment, the first ETL 271 and the second ETL 272 may have the same structure and materials as HTL150. Figure 1 Similar or identical in structure and materials to ETL 170.

[0104] like Figure 3As shown, an organic light-emitting diode 100 according to an exemplary embodiment of this disclosure includes a first electrode 110 and a second electrode 120 facing each other, and an organic layer 330 located between the first electrode 110 and the second electrode 120. The organic layer 330 may be located between the first electrode 110 and the second electrode 120 and may include a first light-emitting stack ST1 including a first light-emitting layer 261, a second light-emitting stack ST2 including a second light-emitting layer 262, a third light-emitting stack ST3 including a third light-emitting layer 263, a first charge-generating layer CGL1 located between the first light-emitting stack ST1 and the second light-emitting stack ST2, and a second charge-generating layer CGL2 located between the second light-emitting stack ST2 and the third light-emitting stack ST3. The first charge-generating layer CGL1 may include an N-type charge-generating layer 291 and a P-type charge-generating layer 292. The second charge-generating layer CGL2 may include an N-type charge-generating layer 293 and a P-type charge-generating layer 294. At least one of the first light-emitting layer 261, the second light-emitting layer 262, and the third light-emitting layer 263 may contain an organometallic compound represented by Chemical Formula 1 as a dopant according to the present disclosure. For example, such as Figure 3 As shown, the second light-emitting layer 262 of the second light-emitting stack ST2 may include a host material 262' and a dopant 262' made of an organometallic compound represented by chemical formula 1 doped therein. Although Figure 3 Not shown, in addition to each of the first light-emitting layer 261, the second light-emitting layer 262, and the third light-emitting layer 263, each of the first light-emitting stack ST1, the second light-emitting stack ST2, and the third light-emitting stack ST3 may further include an additional light-emitting layer. In one embodiment, the first HTL 251, the second HTL 252, and the third HTL 253 may have the same characteristics as... Figure 1 The structure and materials are similar to or the same as those of HTL 150. In one embodiment, the first ETL 271, the second ETL 272, and the third ETL 273 may have the same structure and materials as HTL 150. Figure 1 Similar or identical in structure and materials to ETL 170.

[0105] Furthermore, an organic light-emitting diode according to an exemplary embodiment of this disclosure may include a series structure in which four or more light-emitting stacks and three or more charge-generating layers are disposed between a first electrode and a second electrode.

[0106] Organic light-emitting diodes (OLEDs) according to exemplary embodiments of this disclosure can be used as light-emitting elements in both organic light-emitting display devices and lighting devices. In one embodiment, Figure 4 This is a schematic cross-sectional view of an organic light-emitting display device that includes an organic light-emitting diode as its light-emitting element according to some embodiments of the present disclosure.

[0107] like Figure 4 As shown, the organic light-emitting display device 3000 includes a substrate 3010, an organic light-emitting diode 4000, and an encapsulation film 3900 covering the organic light-emitting diode 4000. A driving thin-film transistor Td, which serves as a driving element, and the organic light-emitting diode 4000 connected to the driving thin-film transistor Td are located on the substrate 3010.

[0108] Despite Figure 4 It is not explicitly shown that, on substrate 3010, gate lines and data lines that intersect each other to define pixel regions, a power line that extends parallel to and is spaced apart from one of the gate lines and data lines, a switching thin-film transistor connected to the gate lines and data lines, and a storage capacitor connected to an electrode of the thin-film transistor and the power line are further formed.

[0109] The driving thin-film transistor Td is connected to the switching thin-film transistor and includes a semiconductor layer 3100, a gate 3300, a source 3520, and a drain 3540.

[0110] Semiconductor layer 3100 can be formed on substrate 3010 and can be made of oxide semiconductor material or polysilicon. When semiconductor layer 3100 is made of oxide semiconductor material, a light-shielding pattern (not shown) can be formed below semiconductor layer 3100. The light-shielding pattern prevents light from entering semiconductor layer 3100, thereby preventing semiconductor layer 3100 from being degraded by light. Alternatively, semiconductor layer 3100 can be made of polysilicon. In this case, both edges of semiconductor layer 3100 can be doped with impurities.

[0111] A gate insulating layer 3200 made of insulating material is formed on the entire surface of the substrate 3010 and on the semiconductor layer 3100. The gate insulating layer 3200 may be made of an inorganic insulating material such as silicon oxide or silicon nitride.

[0112] A gate 3300, made of a conductive material such as metal, is formed on the gate insulating layer 3200 and corresponds to the center of the semiconductor layer 3100. The gate 3300 is connected to a switching thin-film transistor.

[0113] An interlayer insulating layer 3400 made of insulating material is formed on the entire surface of the substrate 3010 and on the gate 3300. The interlayer insulating layer 3400 may be made of inorganic insulating materials such as silicon oxide or silicon nitride, or organic insulating materials such as benzocyclobutene or optical acrylic.

[0114] The interlayer insulating layer 3400 has a first semiconductor layer contact hole 3420 and a second semiconductor layer contact hole 3440 defined therein to expose opposite sides of the semiconductor layer 3100, respectively. The first semiconductor layer contact hole 3420 and the second semiconductor layer contact hole 3440 are located on opposite sides of the gate 3300 and spaced apart from the gate 3300.

[0115] Source 3520 and drain 3540, made of a conductive material such as metal, are formed on the interlayer insulating layer 3400. Source 3520 and drain 3540 are located around the gate 3300 and spaced apart from each other, and each contacts opposite sides of the semiconductor layer 3100 through a first semiconductor layer contact hole 3420 and a second semiconductor layer contact hole 3440, respectively. Source 3520 is connected to a power supply line (not shown).

[0116] Semiconductor layer 3100, gate 3300, source 3520 and drain 3540 constitute driving thin film transistor Td. Driving thin film transistor Td has a coplanar structure, wherein gate 3300, source 3520 and drain 3540 are located on top of semiconductor layer 3100.

[0117] Alternatively, the driving thin-film transistor Td can have an anti-interleaved structure, where the gate is disposed below the semiconductor layer, while the source and drain are disposed above the semiconductor layer. In this case, the semiconductor layer can be made of amorphous silicon. In one example, the switching thin-film transistor (not shown) can have substantially the same structure as the driving thin-film transistor (Td).

[0118] In one example, the organic light-emitting display device 3000 may include a color filter 3600 that absorbs light generated from an electroluminescent element (light-emitting diode) 4000. For example, the color filter 3600 may absorb red (R), green (G), blue (B), and white (W) light. In this case, red, green, and blue color filter patterns that absorb light can be formed separately in different pixel areas. Each of these color filter patterns may be configured to overlap with each organic layer 4300 of the organic light-emitting diode 4000 to emit light corresponding to the wavelength band of each color filter. Using the color filter 3600 enables the organic light-emitting display device 3000 to achieve full color.

[0119] For example, when the organic light-emitting display device 3000 is a bottom-emitting type, the light-absorbing color filter 3600 can be disposed on a portion of the interlayer insulating layer 3400 corresponding to the organic light-emitting diode 4000. In an alternative embodiment, when the organic light-emitting display device 3000 is a top-emitting type, the color filter can be disposed on the top of the organic light-emitting diode 4000, i.e., on the top of the second electrode 4200. For example, the color filter 3600 can be formed to have a thickness of 2-5 μm.

[0120] In one example, a protective layer 3700 is formed to cover the driving thin-film transistor Td, the protective layer 3700 having a drain contact hole 3720 defined therein for exposing the drain 3540 of the driving thin-film transistor Td.

[0121] On the protective layer 3700, each first electrode 4100 connected to the drain 3540 of the driving thin film transistor Td via a drain contact hole 3720 is formed in each pixel region.

[0122] The first electrode 4100 can be used as a positive electrode (anode) and can be made of a conductive material with a relatively large work function value. For example, the first electrode 4100 can be made of a transparent conductive material such as ITO, IZO or ZnO.

[0123] In one example, when the organic light-emitting display device 3000 is a top-emitting type, a reflective electrode or reflective layer may be further formed below the first electrode 4100. For example, the reflective electrode or reflective layer may include at least one of aluminum (Al), silver (Ag), nickel (Ni), or an aluminum-palladium-copper (APC) alloy.

[0124] A dam layer 3800 covering the edge of the first electrode 4100 is formed on the protective layer 3700. The dam layer 3800 exposes the center of the first electrode 4100 corresponding to the pixel region.

[0125] An organic layer 4300 is formed on the first electrode 4100. The organic light-emitting diode 4000 may have a series structure if needed. For information on series structures, please refer to... Figures 2 to 4 This illustrates some embodiments of the present disclosure and the above description thereof.

[0126] The second electrode 4200 is formed on the substrate 3010 on which the organic layer 4300 has been formed. The second electrode 4200 is disposed on the entire surface of the display area and is made of a conductive material with a relatively small work function value, and the second electrode 4200 can be used as a negative electrode (cathode). For example, the second electrode 4200 can be made of aluminum (Al), magnesium (Mg), and an aluminum-magnesium alloy (Al-Mg).

[0127] The first electrode 4100, the organic layer 4300, and the second electrode 4200 constitute an organic light-emitting diode 4000.

[0128] An encapsulation film 3900 is formed on the second electrode 4200 to prevent external moisture from penetrating into the organic light-emitting diode 4000. Although in Figure 4 It is not explicitly shown that the encapsulation film 3900 may have a three-layer structure in which a first inorganic layer, an organic layer, and an inorganic layer are stacked sequentially. However, this disclosure is not limited thereto.

[0129] The preparation examples and embodiments of this disclosure will be described below. However, the following embodiment is merely one example of this disclosure. This disclosure is not limited thereto.

[0130] Preparation Example - Preparation of Ligands

[0131] (1) Preparation of ligand compound S

[0132]

[0133] Under a nitrogen atmosphere, compounds SM-1 (4.58 g, 20 mmol), SM-2 (3.67 g, 20 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated under reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound S (4.72 g, 82%).

[0134] (2) Preparation of ligand compound A

[0135] Step 1) Preparation of ligand compound A-1

[0136]

[0137] Under a nitrogen atmosphere, compounds S (4.94 g, 20 mmol), SM-3 (4.05 g, 19 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated under reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound A-1 (5.18 g, 77%).

[0138] Step 2) Preparation of ligand compound A

[0139]

[0140] Under a nitrogen atmosphere, compound A-1 (5.18 g, 15 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound A (3.65 g, 75%).

[0141] (3) Preparation of ligand compound B

[0142] Step 1) Preparation of ligand compound B-1

[0143]

[0144] Under a nitrogen atmosphere, compound S (4.94 g, 20 mmol), compound SM-3' (4.79 g, 21 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated to reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound B-1 (5.38 g, 80%).

[0145] Step 2) Preparation of ligand compound B

[0146]

[0147] Under a nitrogen atmosphere, compound B-1 (5.38 g, 15 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound B (3.4 g, 67%).

[0148] (4) Preparation of ligand compound C

[0149] Step 1) Preparation of ligand compound C-1

[0150]

[0151] Under a nitrogen atmosphere, compounds S (4.94 g, 20 mmol), SM-4 (4.47 g, 21 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated under reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound C-1 (5.44 g, 81%).

[0152] Step 2) Preparation of ligand compound C

[0153]

[0154] Under a nitrogen atmosphere, compound C-1 (5.44 g, 16 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound C (3.53 g, 69%).

[0155] (5) Preparation of ligand compound D

[0156] Step 1) Preparation of ligand compound D-1

[0157]

[0158] Under a nitrogen atmosphere, compound S (4.94 g, 20 mmol), compound SM-4' (5.02 g, 22 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated to reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound D-1 (5.58 g, 83%).

[0159] Step 2) Preparation of ligand compound D

[0160]

[0161] Under a nitrogen atmosphere, compound D-1 (5.58 g, 16 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound D (3.79 g, 72%).

[0162] (6) Preparation of ligand compound E

[0163] Step 1) Preparation of ligand compound E-1

[0164]

[0165] Under a nitrogen atmosphere, compounds S (4.94 g, 20 mmol), SM-5 (4.26 g, 20 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated under reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound E-1 (5.38 g, 80%).

[0166] Step 2) Preparation of ligand compound E

[0167]

[0168] Under a nitrogen atmosphere, compound E-1 (5.38 g, 16 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound E (3.74 g, 74%).

[0169] (7) Preparation of ligand compound F

[0170] Step 1) Preparation of ligand compound F-1

[0171]

[0172] Under a nitrogen atmosphere, compound S (4.94 g, 20 mmol), compound SM-5' (4.33 g, 20 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated to reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound F-1 (5.51 g, 82%).

[0173] Step 2) Preparation of ligand compound F

[0174]

[0175] Under a nitrogen atmosphere, compound F-1 (5.51 g, 16 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. Water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound F (3.74 g, 72%).

[0176] (8) Preparation of ligand compound G

[0177] Step 1) Preparation of ligand compound G-1

[0178]

[0179] Under a nitrogen atmosphere, compounds S (4.94 g, 20 mmol), SM-6 (4.69 g, 20 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated under reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound G-1 (5.04 g, 75%).

[0180] Step 2) Preparation of ligand compound G

[0181]

[0182] Under a nitrogen atmosphere, compound G-1 (5.04 g, 15 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound G (3.41 g, 72%).

[0183] (9) Preparation of ligand compound H

[0184] Step 1) Preparation of ligand compound H-1

[0185]

[0186] Under a nitrogen atmosphere, compound S (4.94 g, 20 mmol), compound SM-6' (5.02 g, 22 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated to reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound H-1 (5.11 g, 76%).

[0187] Step 2) Preparation of ligand compound H

[0188]

[0189] Under a nitrogen atmosphere, compound H-1 (5.11 g, 15 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound H (3.61 g, 75%).

[0190] (10) Preparation of ligand compound I

[0191] Step 1) Preparation of ligand compound I-1

[0192]

[0193] Under a nitrogen atmosphere, compounds S (4.94 g, 20 mmol), SM-7 (4.26 g, 20 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated under reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound I-1 (5.31 g, 79%).

[0194] Step 2) Preparation of ligand compound I

[0195]

[0196] Under a nitrogen atmosphere, compound I-1 (5.31 g, 15 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. Water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound I (3.75 g, 75%).

[0197] (11) Preparation of ligand compound J

[0198] Step 1) Preparation of ligand compound J-1

[0199]

[0200] Under a nitrogen atmosphere, compound S (4.94 g, 20 mmol), compound SM-7' (4.33 g, 19 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated to reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound J-1 (5.11 g, 76%).

[0201] Step 2) Preparation of ligand compound J

[0202]

[0203] Under a nitrogen atmosphere, compound J-1 (5.11 g, 15 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. Water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound J (3.37 g, 70%).

[0204] (12) Preparation of ligand compound K

[0205] Step 1) Preparation of ligand compound K-1

[0206]

[0207] Under a nitrogen atmosphere, compounds S (4.94 g, 20 mmol), SM-8 (4.47 g, 21 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated under reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound K-1 (5.51 g, 82%).

[0208] Step 2) Preparation of ligand compound K

[0209]

[0210] Under a nitrogen atmosphere, compound K-1 (5.51 g, 16 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound K (3.52 g, 68%).

[0211] (13) Preparation of ligand compound L

[0212] Step 1) Preparation of ligand compound L-1

[0213]

[0214] Under a nitrogen atmosphere, compound S (4.94 g, 20 mmol), compound SM-8' (4.79 g, 21 mmol), Pd(PPh3)4 (2.31 g, 2 mmol), P(t-Bu)3 (0.81 g, 4 mmol), and NaOtBu (7.68 g, 80 mmol) were dissolved in 200 mL of toluene in a 250 mL round-bottom flask. The mixture was then heated under reflux and stirred for 12 hours. After the reaction was complete, the temperature was lowered to room temperature, the organic layer was extracted with dichloromethane and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered through a filter, concentrated under reduced pressure, and then separated by column chromatography with ethyl acetate and hexane to give compound L-1 (5.24 g, 78%).

[0215] Step 2) Preparation of ligand compound L

[0216]

[0217] Under a nitrogen atmosphere, compound L-1 (5.24 g, 15 mmol) was dissolved in 80 mL of acetic acid and 25 mL of THF in a 250 mL round-bottom flask. Then, tert-butyl nitrite (5 mL, 38 mmol) was added dropwise to the mixture at 0 °C, and the mixture was stirred. After stirring at 0 °C for 4 hours, the temperature was raised to room temperature, the organic layer was extracted with ethyl acetate, and washed thoroughly with water. The water was removed with anhydrous magnesium sulfate, and the solution was filtered, concentrated under reduced pressure, and then separated by column chromatography with dichloromethane and hexane to give compound L (3.51 g, 71%).

[0218] Preparation Example - Preparation of Iridium Compound Precursors (Iridium Precursors)

[0219] (1) Preparation of iridium precursor compound M'

[0220] Step 1) Preparation of compound MM

[0221]

[0222] Under a nitrogen atmosphere, compound M (3.38 g, 20 mmol) and IrCl3 (2.39 g, 8.0 mmol) were dissolved in a mixture of ethoxyethanol and distilled water (90 mL: 30 mL) and added to a 250 mL round-bottom flask. The mixture was refluxed and stirred for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, and the solid was separated from the solid by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol, and then filtered repeatedly under reduced pressure to obtain 4.24 g (94%) of solid compound MM.

[0223] Step 2) Preparation of iridium precursor compound M'

[0224]

[0225] In a 250 mL round-bottom flask, compound MM (4.51 g, 4 mmol) and silver trifluoromethanesulfonate (AgOTf, 3.02 g, 12 mmol) were dissolved in dichloromethane, and the mixture was stirred at room temperature for 24 hours. After the reaction was complete, the solid precipitate was removed by diatomaceous earth filtration. The resulting filtrate was filtered through a filter and distilled under reduced pressure to obtain 5.34 g (90%) of the obtained solid compound M'.

[0226] (2) Preparation of iridium precursor compound A'

[0227] Step 1) Preparation of compound AA

[0228]

[0229] Under a nitrogen atmosphere, compound A (6.32 g, 20 mmol) and IrCl3 (2.39 g, 8.0 mmol) were dissolved in a mixture of ethoxyethanol and distilled water (90 mL: 30 mL) and added to a 250 mL round-bottom flask. The mixture was heated to reflux and stirred for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, and the solid was separated from the solid by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol, and then filtered repeatedly under reduced pressure to obtain 9.23 g (85%) of solid compound AA.

[0230] Step 2) Preparation of iridium precursor compound A'

[0231]

[0232] In a 250 mL round-bottom flask, compound AA (4.34 g, 4 mmol) and silver trifluoromethanesulfonate (AgOTf, 3.02 g, 12 mmol) were dissolved in dichloromethane, and the mixture was stirred at room temperature for 24 hours. After the reaction was complete, the solid precipitate was removed by diatomaceous earth filtration. The resulting filtrate was filtered through a filter and distilled under reduced pressure to obtain 2.51 g (87%) of the obtained solid compound A'.

[0233] (3) Preparation of iridium precursor compound C'

[0234] Step 1) Preparation of compound CC

[0235]

[0236] Under a nitrogen atmosphere, compound C (6.32 g, 20 mmol) and IrCl3 (2.39 g, 8.0 mmol) were dissolved in a mixture of ethoxyethanol and distilled water (90 mL: 30 mL) and added to a 250 mL round-bottom flask. The mixture was heated to reflux and stirred for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, and the solid was separated from the solid by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol, and then filtered repeatedly under reduced pressure to obtain 6.88 g (86%) of solid compound CC.

[0237] Step 2) Preparation of iridium precursor compound C'

[0238]

[0239] In a 250 mL round-bottom flask, compound CC (4.34 g, 4 mmol) and silver trifluoromethanesulfonate (AgOTf, 3.02 g, 12 mmol) were dissolved in dichloromethane, and the mixture was stirred at room temperature for 24 hours. After the reaction was complete, the solid precipitate was removed by diatomaceous earth filtration. The resulting filtrate was filtered through a filter and distilled under reduced pressure to obtain 2.336 g (81%) of the obtained solid compound C'.

[0240] (4) Preparation of iridium precursor compound E'

[0241] Step 1) Preparation of compound EE

[0242]

[0243] Under a nitrogen atmosphere, compound E (6.32 g, 20 mmol) and IrCl3 (2.39 g, 8.0 mmol) were dissolved in a mixture of ethoxyethanol and distilled water (90 mL: 30 mL) and added to a 250 mL round-bottom flask. The mixture was heated to reflux and stirred for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, and the solid was separated from the solid by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol, and the filtration was repeated several times under reduced pressure to obtain 9.67 g (89%) of solid compound EE.

[0244] Step 2) Preparation of iridium precursor compound E'

[0245]

[0246] In a 250 mL round-bottom flask, compound EE (4.34 g, 4 mmol) and silver trifluoromethanesulfonate (AgOTf, 3.02 g, 12 mmol) were dissolved in dichloromethane, and the mixture was stirred at room temperature for 24 hours. After the reaction was complete, the solid precipitate was removed by diatomaceous earth filtration. The resulting filtrate was filtered through a filter and distilled under reduced pressure to obtain 2.36 g (88%) of the obtained solid compound E'.

[0247] (5) Preparation of iridium precursor compound G'

[0248] Step 1) Preparation of compound GG

[0249]

[0250] Under a nitrogen atmosphere, compound G (6.32 g, 20 mmol) and IrCl3 (2.39 g, 8.0 mmol) were dissolved in a mixture of ethoxyethanol and distilled water (90 mL: 30 mL) and added to a 250 mL round-bottom flask. The mixture was heated to reflux and stirred for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, and the solid was separated from the solid by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol, and the filtration was repeated several times under reduced pressure to obtain 9.34 g (56%) of solid compound GG.

[0251] Step 2) Preparation of iridium precursor compound G'

[0252]

[0253] In a 250 mL round-bottom flask, compound GG (4.34 g, 4 mmol) and silver trifluoromethanesulfonate (AgOTf, 3.02 g, 12 mmol) were dissolved in dichloromethane, and the mixture was stirred at room temperature for 24 hours. After the reaction was complete, the solid precipitate was removed by diatomaceous earth filtration. The resulting filtrate was filtered through a filter and distilled under reduced pressure to obtain 2.57 g (89%) of the obtained solid compound G'.

[0254] (6) Preparation of iridium precursor compound I'

[0255] Step 1) Preparation of Compound II

[0256]

[0257] Under a nitrogen atmosphere, compound I (6.32 g, 20 mmol) and IrCl3 (2.39 g, 8.0 mmol) were dissolved in a mixture of ethoxyethanol and distilled water (90 mL: 30 mL) and added to a 250 mL round-bottom flask. The mixture was heated to reflux and stirred for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, and the solid was separated from the solid by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol, and then filtered repeatedly under reduced pressure to obtain 9.232 g (89%) of solid compound II.

[0258] Step 2) Preparation of iridium precursor compound I'

[0259]

[0260] In a 250 mL round-bottom flask, compound II (4.34 g, 4 mmol) and silver trifluoromethanesulfonate (AgOTf, 3.02 g, 12 mmol) were dissolved in dichloromethane, and the mixture was stirred at room temperature for 24 hours. After the reaction was complete, the solid precipitate was removed by diatomaceous earth filtration. The resulting filtrate was filtered through a filter and distilled under reduced pressure to obtain 2.36 g (82%) of the obtained solid compound I'.

[0261] (7) Preparation of iridium precursor compound K'

[0262] Step 1) Preparation of compound KK

[0263]

[0264] Under a nitrogen atmosphere, compound K (6.32 g, 20 mmol) and IrCl3 (2.39 g, 8.0 mmol) were dissolved in a mixture of ethoxyethanol and distilled water (90 mL: 30 mL) and added to a 250 mL round-bottom flask. The mixture was heated to reflux and stirred for 24 hours. After the reaction was complete, the temperature was lowered to room temperature, and the solid was separated from the solid by filtration under reduced pressure. The solid was filtered through a filter and washed thoroughly with water and cold methanol, and then filtered repeatedly under reduced pressure to obtain 9.67 g (89%) of solid compound KK.

[0265] Step 2) Preparation of iridium precursor compound K'

[0266]

[0267] In a 250 mL round-bottom flask, compound KK (4.34 g, 4 mmol) and silver trifluoromethanesulfonate (AgOTf, 3.02 g, 12 mmol) were dissolved in dichloromethane, and the mixture was stirred at room temperature for 24 hours. After the reaction was complete, the solid precipitate was removed by diatomaceous earth filtration. The resulting filtrate was filtered through a filter and distilled under reduced pressure to obtain 2.57 g (81%) of the obtained solid compound K'.

[0268] Preparation Example - Preparation of Iridium Compounds

[0269] 1. Preparation of Iridium Compound 113

[0270]

[0271] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound A (3.16 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 113 (3.2 g, 91%).

[0272] 2. Preparation of Iridium Compound 115

[0273]

[0274] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound B (3.3 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 115 (2.94 g, 82%).

[0275] 3. Preparation of Iridium Compound 123

[0276]

[0277] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound C (3.16 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 123 (2.94 g, 82%).

[0278] 4. Preparation of Iridium Compound 125

[0279]

[0280] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound D (3.3 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 125 (2.94 g, 82%).

[0281] 5. Preparation of Iridium Compound 133

[0282]

[0283] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound E (3.16 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 133 (3.06 g, 87%).

[0284] 6. Preparation of Iridium Compound 135

[0285]

[0286] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound F (3.3 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 135 (3.27 g, 91%).

[0287] 7. Preparation of Iridium Compound 143

[0288]

[0289] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound G (3.16 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 143 (2.85 g, 81%).

[0290] 8. Preparation of Iridium Compound 145

[0291]

[0292] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound H (3.3 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 145 (3.2 g, 89%).

[0293] 9. Preparation of Iridium Compound 153

[0294]

[0295] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound I (3.16 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 153 (2.96 g, 84%).

[0296] 10. Preparation of Iridium Compound 155

[0297]

[0298] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound J (3.3 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 155 (3.23 g, 90%).

[0299] 11. Preparation of Iridium Compound 161

[0300]

[0301] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound K (3.16 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 161 (3.1 g, 88%).

[0302] 12. Preparation of Iridium Compound 163

[0303]

[0304] Under a nitrogen atmosphere, iridium precursor compound M' (3.01 g, 5 mmol) and ligand compound L (3.3 g, 10 mmol) were added to a round-bottom flask containing 100 mL of 2-ethoxyethanol and 100 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 25:75 to obtain iridium compound 163 (3.09 g, 86%).

[0305] 13. Preparation of Iridium Compound 169

[0306]

[0307] Under a nitrogen atmosphere, iridium precursor compound A' (3.61 g, 5 mmol) and ligand compound O (0.94 g, 6 mmol) were added to a 150 mL round-bottom flask containing 50 mL of 2-ethoxyethanol and 50 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 50:50 to obtain iridium compound 169 (4.60 g, 89%).

[0308] 14. Preparation of Iridium Compound 179

[0309]

[0310] Under a nitrogen atmosphere, iridium precursor C' (3.61 g, 5 mmol) and ligand O (0.94 g, 6 mmol) were added to a 150 mL round-bottom flask containing 50 mL of 2-ethoxyethanol and 50 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 50:50 to obtain iridium compound 179 (4.24 g, 82%).

[0311] 15. Preparation of Iridium Compound 189

[0312]

[0313] Under a nitrogen atmosphere, iridium precursor E' (3.61 g, 5 mmol) and ligand O (0.94 g, 6 mmol) were added to a 150 mL round-bottom flask containing 50 mL of 2-ethoxyethanol and 50 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 50:50 to obtain iridium compound 189 (4.60 g, 89%).

[0314] 16. Preparation of Iridium Compound 199

[0315]

[0316] Under a nitrogen atmosphere, iridium precursor compound G' (3.61 g, 5 mmol) and ligand compound O (0.94 g, 6 mmol) were added to a 150 mL round-bottom flask containing 50 mL of 2-ethoxyethanol and 50 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 50:50 to obtain iridium compound 199 (4.55 g, 88%).

[0317] 17. Preparation of Iridium Compound 209

[0318]

[0319] Under a nitrogen atmosphere, iridium precursor compound I' (3.61 g, 5 mmol) and ligand compound O (0.94 g, 6 mmol) were added to a 150 mL round-bottom flask containing 50 mL of 2-ethoxyethanol and 50 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 50:50 to obtain iridium compound 209 (4.45 g, 86%).

[0320] 18. Preparation of Iridium Compound 217

[0321]

[0322] Under a nitrogen atmosphere, iridium precursor compound K' (3.61 g, 5 mmol) and ligand compound O (0.94 g, 6 mmol) were added to a 150 mL round-bottom flask containing 50 mL of 2-ethoxyethanol and 50 mL of DMF. The mixture was then heated and stirred at 130 °C for 24 hours. When the reaction was complete, the temperature was lowered to room temperature, and the organic layer was extracted with dichloromethane and distilled water, with water removed by adding anhydrous magnesium sulfate. The filtrate was filtered and subjected to reduced pressure to obtain the crude product. The crude product was purified by column chromatography at ethyl acetate:hexane = 50:50 to obtain iridium compound 217 (4.65 g, 90%).

[0323] This embodiment

[0324] <Example 1>

[0325] Clean it and coat it with a thickness of An ITO (indium tin oxide) thin film was formed on a glass substrate, and then ultrasonically cleaned with a solvent such as isopropanol, acetone, or methanol. The glass substrate was then dried. This formed an ITO transparent electrode. HI-1, serving as a hole injection material, was deposited on the ITO transparent electrode using thermal vacuum deposition. This formed a hole injection layer with a thickness of 60 nm. Then, NPB, serving as a hole transport material, was deposited on the hole injection layer using thermal vacuum deposition. This formed a hole transport layer with a thickness of 80 nm. Then, CBP, serving as the host material for the light-emitting layer, was deposited on the hole transport layer using thermal vacuum deposition. Compound 113, serving as a dopant, was doped into the host material at a doping concentration of 5%. This formed a light-emitting layer with a thickness of 30 nm. ET-1:Liq (1:1) (30 nm), serving as both an electron transport layer and an electron injection layer, was deposited on the light-emitting layer. Then, a 100 nm thick layer of aluminum was deposited on top to form the negative electrode. In this manner, an organic light-emitting diode emitting green light was fabricated.

[0326]

[0327] HI-1 refers to N1,N1'-([1,1'-biphenyl]-4,4'-diyl)bis(N1,N4,N4-triphenylphenyl-1,4-diamine).

[0328] ET-1 refers to 2-(4-(9,10-bis(naphthyl-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole.

[0329] <Examples 2 to 24 and Comparative Examples 1 to 4>

[0330] Organic light-emitting diodes of Examples 2 to 24 and Comparative Examples 1 to 4 were manufactured in the same manner as in Example 1, except that the compounds shown in Tables 1 to 2 below were used instead of compound 113 as dopants in Example 1.

[0331] Performance Evaluation of Organic Light Emitting Diodes

[0332] Regarding the organic light-emitting diodes prepared according to Examples 1 to 24 and Comparative Examples 1 to 4, measurements were taken at 10 mA / cm². 2 Operating voltage and efficiency characteristics at current, and at 20mA / cm 2 The lifetime characteristics under accelerated conditions were determined. Therefore, the operating voltage (V), EQE (external quantum efficiency) (%), and LT95 (%) were measured and converted to values ​​relative to Comparative Example 1. The results are shown in Tables 1 and 2 below. LT95 refers to the lifetime assessment scheme and is the time required for the organic light-emitting diode to lose 5% of its initial brightness.

[0333] Table 1

[0334]

[0335]

[0336] Table 2

[0337]

[0338] The structures of Ref-1 to Ref-4, which are used as doping materials in Comparative Examples 1 to 4 in Tables 1 and 2 above, are as follows.

[0339] Ref-1:

[0340] Ref-2:

[0341] Ref-3:

[0342] Ref-4:

[0343] The results in Tables 1 and 2 above show that, compared to each of Comparative Examples 1 to 4, in the organic light-emitting diodes in each of Examples 1 to 24 according to the present disclosure, where the organometallic compound is used as a dopant in the light-emitting layer of the diode, the operating voltage of the diode is reduced, and the maximum luminous efficiency, external quantum efficiency (EQE), and lifetime (LT95) of the diode are improved.

[0344] The scope of protection of this disclosure should be understood through the scope of the claims, and all technical concepts within the scope of the claims should be understood to be included within the scope of this disclosure. Although embodiments of this disclosure have been described in more detail with reference to the accompanying drawings, this disclosure is not necessarily limited to these embodiments. This disclosure can be implemented in various modifications without departing from the scope of the technical concept of this disclosure. Therefore, the embodiments disclosed in this disclosure are not intended to limit the technical concept of this disclosure, but are used to describe this disclosure. The scope of the technical concept of this disclosure is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative and not restrictive in all respects. The scope of protection of this disclosure should be interpreted through the claims, and all technical concepts within the scope of this disclosure should be understood to be included within the scope of this disclosure.

Claims

1. An organic light-emitting diode, comprising: First electrode; The second electrode facing the first electrode; and An organic layer disposed between the first electrode and the second electrode. The organic layer mentioned above includes a light-emitting layer. The light-emitting layer contains doped material, and The doped material includes an organometallic compound, and the organometallic compound is compound 135:

2. The organic light-emitting diode according to claim 1, wherein the light-emitting layer comprises a green light-emitting layer.

3. The organic light-emitting diode according to claim 1, wherein the organic layer further comprises a hole injection layer, a hole transport layer, an electron transport layer, or an electron injection layer.

4. An organic light-emitting diode, comprising: The first and second electrodes facing each other; and The first light-emitting stack and the second light-emitting stack are located between the first electrode and the second electrode. Each of the first light-emitting stack and the second light-emitting stack includes at least one light-emitting layer. The at least one light-emitting layer includes a green phosphorescent light-emitting layer. The green phosphorescent emitting layer contains doped materials, and The doped material includes an organometallic compound, and the organometallic compound is compound 135:

5. An organic light-emitting diode, comprising: The first and second electrodes facing each other; and The first light-emitting stack, the second light-emitting stack, and the third light-emitting stack are located between the first electrode and the second electrode. Each of the first light-emitting stack, the second light-emitting stack, and the third light-emitting stack includes at least one light-emitting layer. The at least one light-emitting layer includes a green phosphorescent light-emitting layer. The green phosphorescent emitting layer contains doped materials, and The doped material includes an organometallic compound, and the organometallic compound is compound 135:

6. An organic light-emitting display device, comprising: substrate; Drive elements located on the substrate; and An organic light-emitting element, wherein the organic light-emitting element is disposed on the substrate and connected to the driving element, wherein the organic light-emitting element includes an organic light-emitting diode according to claim 1.

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