Ligand compound, metal organic complex and application thereof

Abstract

The invention relates to a ligand compound, a metal organic complex and application thereof. The ligand compound has a structure as shown in a formula I. By introducing a deuterated group at a specific position, the space structure size and form of the organic electroluminescent device can be adjusted, so that the prepared organic electroluminescent device has the advantages of long service life, high efficiency and low voltage.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent display technology, and specifically discloses a ligand compound, an organometallic complex, and their application in organic electroluminescent devices. Background Technology

[0002] Organic light-emitting diodes (OLEDs) emit light in two forms: fluorescence and phosphorescence. Fluorescence is emitted using the energy of singlet excitons, while phosphorescence is emitted using the energy of both singlet and triplet excitons. Because the ratio of singlet to triplet excitons is fixed at 1:3, theoretically, the internal quantum efficiency of fluorescent devices using only singlet excitons is at most 25%, while the internal quantum efficiency of phosphorescent devices can reach 100%.

[0003] Currently, organometallic complexes and organic electroluminescent devices exhibiting phosphorescence emission have been reported, and various organometallic complex phosphorescent doped materials have been disclosed in patents. For example, US Patent EP3825320A1 discloses a class of Ir complexes containing pyridine and dibenzofuran ligands. However, these compounds suffer from serious problems such as low phosphorescence efficiency, poor stability, and poor lifetime, thus hindering their commercialization. Therefore, structural improvements to these compounds, such as introducing nitrogen-containing groups at the pyridine substitution sites and phenyl groups and their derivatives at the dibenzofuran substitution sites, to develop new phosphorescent doped materials with better performance and promote commercial applications, will be of great significance. Summary of the Invention

[0004] The purpose of this invention is to develop a ligand compound, an organometallic complex, and its applications. When this organometallic complex is applied to organic electroluminescent devices, the resulting devices exhibit superior performance in terms of high purity, high brightness, and high efficiency.

[0005] Specifically, in a first aspect, the present invention provides a ligand compound having a structure as shown in Formula I:

[0006]

[0007] X1 and X2 are each independently selected from any one of single bonds, O, S, and Se; at most one of X1 and X2 is a single bond.

[0008] Z1, Z2, Z3, Z4, Z5, and Z6 are each independently selected from CR. Z Or N, multiple (e.g., 2, 3, 4, 5, 6) CRs Z R in Z They can be the same or different groups;

[0009] U1, U2, U3, and U4 are each independently selected from CR U Or N, multiple (e.g., 2, 3, 4) CRs U R in U They can be the same or different groups;

[0010] R Z R U Each is independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; the R Z R U Each group can independently form a ring without being connected to adjacent groups or by chemical bonds.

[0011] The R Z R U The substituents described herein are each independently selected from any one or a combination of at least two of the following: deuterium, halogen, cyano, nitro, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkylsilyl, C3-C20 cycloalkyl, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 aryl, and C3-C30 heteroaryl.

[0012] According to some embodiments of the present invention, the ligand compound has a structure as shown in Formula I-1 or Formula I-2:

[0013]

[0014] Among them, the definitions of Z1, Z2, Z3, Z4, Z5, Z6, U1, U2, U3, and U4 are the same as those in Formula I; X1 and X2 are each independently selected from O, S, or Se; preferably O or S.

[0015] According to some embodiments of the present invention, at most one (0 or 1) of Z1, Z2, Z3, Z4, Z5, and Z6 is selected from N.

[0016] Preferably, Z1, Z2, Z3, Z4, Z5, and Z6 are each independently selected from CR. Z .

[0017] Preferably, R ZEach is independently selected from hydrogen, deuterium, halogens (e.g., F, Cl, Br, I), cyano, nitro, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkyl, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkoxy, and C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkyl Silicon-based, C3-C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, C18, etc.) arylamino, C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroarylamino, C6-C20 (e.g., C 6. C9, C10, C12, C14, C15, C16, C18, etc.) aryloxy groups; C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaryloxy groups; C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, C18, etc.) aryl groups; C3-C20 (e.g., C3, C... 4. Any one or a combination of at least two of the heteroaryl groups (C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.); more preferably, any one or a combination of at least two of the following groups: hydrogen, deuterium, halogen, cyano, C1-C10 alkyl, C3-C10 cycloalkyl, C6-C20 aryl, C3-C20 heteroaryl; even more preferably, hydrogen, deuterium, F, CN, or any of the following groups:

[0018]

[0019] According to some embodiments of the present invention, at most one (0 or 1) of U1, U2, U3, and U4 is selected from N.

[0020] Preferably, U1, U2, U3, and U4 are each independently selected from CR. U .

[0021] Preferably, R UEach group is independently selected from any one or at least a combination of two of the following: hydrogen, deuterium, halogen (e.g., F, Cl, Br, I), cyano, nitro, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkyl, C3-C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, C18, etc.) aryl, and C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaryl; further preferably selected from hydrogen, F, CN, or any of the following groups:

[0022]

[0023] According to some embodiments of the present invention, the ligand compound is selected from the group consisting of the following structures:

[0024]

[0025]

[0026]

[0027] In a second aspect, the present invention provides a metal-organic complex comprising a metal atom M and a first ligand La, wherein the relative atomic mass of the metal atom M is greater than 40, and the first ligand La has a structure as shown in Formula II:

[0028]

[0029] Wherein, the dashed line represents the binding site between the first ligand La and the metal atom M;

[0030] X1 and X2 are each independently selected from any one of single bonds, O, S, and Se; at most one of X1 and X2 is a single bond;

[0031] Z1, Z2, Z3, Z4, Z5, and Z6 are each independently selected from CR. Z Or N, multiple (e.g., 2, 3, 4, 5, 6) CRs Z R in Z They can be the same or different groups;

[0032] U1, U2, U3, and U4 are each independently selected from CR U Or N, multiple (e.g., 2, 3, 4) CRs U R in U They can be the same or different groups;

[0033] R Z RU Each is independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; the R Z R U Each group can independently form a ring without being connected to adjacent groups or by chemical bonds.

[0034] The R Z R U The substituents described herein are each independently selected from any one or a combination of at least two of the following: deuterium, halogen, cyano, nitro, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkylsilyl, C3-C20 cycloalkyl, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 aryl, and C3-C30 heteroaryl.

[0035] In this invention, the "substituted or unsubstituted" group may be without a substituent, may be substituted with one substituent, or may be substituted with multiple substituents. When there are multiple substituents (at least two), they may be the same or different substituents. The same expression used below has the same meaning.

[0036] It should be noted that, for ease of explanation, the possible effects of each group / feature have been described separately in this invention, but this does not mean that these groups / features act in isolation. In fact, the essential reason for obtaining good performance is the optimized combination of the entire molecular structure, the result of the synergistic effect between various groups, rather than the effect of a single group / feature.

[0037] The following are preferred embodiments of the present invention, but are not intended to limit the embodiments provided by the present invention. The objectives and beneficial effects of the present invention can be better achieved and realized through the following preferred embodiments.

[0038] According to some embodiments of the present invention, the first ligand La has a structure as shown in Formula II-1 or Formula II-2:

[0039]

[0040] The definitions of Z1, Z2, Z3, Z4, Z5, Z6, U1, U2, U3, and U4 are the same as those in Formula II; X1 and X2 are each independently selected from O, S, or Se; preferably O or S.

[0041] According to some embodiments of the present invention, at most one (0 or 1) of Z1, Z2, Z3, Z4, Z5, and Z6 is selected from N.

[0042] Preferably, Z1, Z2, Z3, Z4, Z5, and Z6 are each independently selected from CR. Z .

[0043] Preferably, R Z Each is independently selected from hydrogen, deuterium, halogens (e.g., F, Cl, Br, I), cyano, nitro, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkyl, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkoxy, and C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkyl Silicon-based, C3-C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, C18, etc.) arylamino, C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroarylamino, C6-C20 (e.g., C 6. C9, C10, C12, C14, C15, C16, C18, etc.) aryloxy groups; C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaryloxy groups; C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, C18, etc.) aryl groups; C3-C20 (e.g., C3, C... 4. Any one or a combination of at least two of the heteroaryl groups (C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.); more preferably, any one or a combination of at least two of the following groups: hydrogen, deuterium, halogen, cyano, C1-C10 alkyl, C3-C10 cycloalkyl, C6-C20 aryl, C3-C20 heteroaryl; even more preferably, hydrogen, deuterium, F, CN, or any of the following groups:

[0044]

[0045] According to some embodiments of the present invention, at most one (0 or 1) of U1, U2, U3, and U4 is selected from N.

[0046] Preferably, U1, U2, U3, and U4 are each independently selected from CR. U.

[0047] Preferably, R U Each group is independently selected from any one or at least a combination of two of the following: hydrogen, deuterium, halogen (e.g., F, Cl, Br, I), cyano, nitro, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) alkyl, C3-C10 (e.g., C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C6-C20 (e.g., C6, C9, C10, C12, C14, C15, C16, C18, etc.) aryl, and C3-C20 (e.g., C3, C4, C5, C6, C9, C10, C12, C14, C15, C16, C18, etc.) heteroaryl; further preferably selected from hydrogen, F, CN, or any of the following groups:

[0048]

[0049] According to some embodiments of the present invention, the first ligand La is selected from the group consisting of the following structures:

[0050]

[0051]

[0052]

[0053]

[0054] According to some embodiments of the present invention, the organometallic complex further includes a second ligand and / or a third ligand.

[0055] According to some embodiments of the present invention, the organometallic complex has M(La). i (Lb) j (Lc) k The structure is as follows: La, Lb, and Lc are the first, second, and third ligands coordinated with the metal atom M, respectively; i is selected from 1, 2, or 3; j is selected from 0, 1, or 2; k is selected from 0, 1, or 2; and the sum of i, j, and k is equal to the oxidation state of the metal atom M; when i is greater than or equal to 2, there are multiple (2 or 3) Las that are the same or different; when j is equal to 2, there are two Lbs that are the same or different; when k is equal to 2, there are two Lcs that are the same or different.

[0056] According to some embodiments of the present invention, the second ligand Lb and the third ligand Lc are each independently selected from structures shown in either Formula III or Formula IV:

[0057]

[0058] Among them, R1-R15 Each of the following is independently selected from hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; the R1-R 15 Each group can independently form a ring without being connected to adjacent groups or by chemical bonds.

[0059] The R1-R 15 The substituents described herein are each independently selected from any one or a combination of at least two of the following: deuterium, halogen, cyano, nitro, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkylsilyl, C3-C20 cycloalkyl, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 aryl, and C3-C30 heteroaryl.

[0060] According to some embodiments of the present invention, the first ligand La, the second ligand Lb, and the third ligand Lc can be optionally connected to form a multidentate ligand; for example, any two of the first ligand La, the second ligand Lb, and the third ligand Lc can be connected to form a tetradentate ligand; or, for another example, the first ligand La, the second ligand Lb, and the third ligand Lc can be interconnected to form a hexadentate ligand.

[0061] According to some embodiments of the present invention, the second ligand Lb and the third ligand Lc are each independently selected from any one of the following structures:

[0062]

[0063] The dashed lines represent the binding sites of the second ligand Lb or the third ligand Lc with the metal atom M.

[0064] According to some embodiments of the present invention, the metal atom M is selected from Cu, Pt, Au, Ru, Pd, Rh or Ir; in a preferred embodiment, the metal atom M is selected from Pt or Ir.

[0065] According to a preferred embodiment of the present invention, the metal atom M is selected from Ir.

[0066] Preferably, the organometallic complex has a structure of Ir(La)3 or Ir(La)2(Lb) or Ir(La)(Lb)2 or Ir(La)2(Lc) or Ir(La)(Lb)(Lc); more preferably, it has a structure of Ir(La)(Lb)2 or Ir(La)2(Lc).

[0067] Wherein, when the organometallic complex has the structure Ir(La)3, each occurrence of La is selected from any three of the group consisting of La-1 to La-80, either identically or differently. When the organometallic complex has the structure Ir(La)2(Lb), each occurrence of La is selected from any one or two of the group consisting of La-1 to La-80, either identically or differently, and Lb is selected from any one of the group consisting of Lb-1 to Lb-18. When the organometallic complex has the structure Ir(La)(Lb)2, La is selected from any one of the group consisting of La-1 to La-80, and each occurrence of Lb is selected from any one or two of the group consisting of Lb-1 to Lb-18, either identically or differently. When the organometallic complex has the structure Ir(La)2(Lc), each occurrence of La is selected from any one or two of the group consisting of La-1 to La-80, either identically or differently, and Lc is selected from any one of the group consisting of Lc-1 to Lc-18. When the organometallic complex has the structure Ir(La)(Lb)(Lc), La is selected from any one of the group consisting of La-1 to La-80, Lb is selected from any one of the group consisting of Lb-1 to Lb-18, and Lc is selected from any one of the group consisting of Lc-1 to Lc-18.

[0068] In a preferred embodiment of the present invention, the organometallic complex is selected from the group consisting of the following compounds: wherein compounds M1 to M120 have the structure Ir(La)(Lb)2, wherein the two Lb are identical, and La and Lb are respectively selected from the structures listed in the table below:

[0069]

[0070]

[0071] Compounds M121 to M240 have the structure Ir(La)2(Lc), where the two La values ​​are identical, and the La and Lc values ​​correspond to the structures listed in the table below:

[0072]

[0073]

[0074] Thirdly, the present invention provides the application of the organometallic complex described in the second aspect in organic electronic devices. Specifically, the organic electronic devices include organic electroluminescent devices, optical sensors, solar cells, lighting elements, organic thin-film transistors, organic field-effect transistors, organic thin-film solar cells, information tags, electronic artificial skin sheets, sheet-type scanners, or electronic paper, with organic electroluminescent devices being the most preferred application.

[0075] More preferably, the metal-organic complex is used as a dopant material for the light-emitting layer in an organic electroluminescent device, specifically as a phosphorescent dopant material. Organic electroluminescent devices prepared using the metal-organic complex of this invention exhibit superior performance in terms of high purity, high brightness, and high efficiency.

[0076] Fourthly, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising a light-emitting layer, the light-emitting layer comprising the metal-organic complex provided in the second aspect of the present invention.

[0077] Preferably, the organic electroluminescent device emits red or white light.

[0078] Preferably, the light-emitting layer further includes a host material.

[0079] The main material comprises at least one chemical group selected from the group consisting of: phenyl, pyridinyl, pyrimidinyl, triazine, carbazole, azacarbazole, indolecarbazole, dibenzothiophene, azadibenzothiophene, dibenzofuran, azadibenzofuran, dibenzoselenophene, phenylene, azatriphenylene, fluorenyl, silylfluorenyl, naphthyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, phenanthryl, azaphenanthryl, and combinations thereof.

[0080] Furthermore, the organic electroluminescent device provided by the present invention includes a substrate and an anode layer, a plurality of light-emitting unit layers, and a cathode layer sequentially formed on the substrate; the light-emitting unit layer includes a light-emitting layer, and further includes one or more of a hole injection layer, a hole transport layer, an electron transport layer, and an electron blocking layer, wherein the hole injection layer is formed on the anode layer, the hole transport layer is formed on the hole injection layer, the cathode layer is formed on the electron transport layer, and a plurality of light-emitting layers are located between the hole transport layer and the electron transport layer. Preferably, the light-emitting layer includes the metal-organic complex provided in the second aspect of the present invention.

[0081] More preferably, the doping concentration of the organometallic complex in the host material is 1-12% (e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, or any value between them), more preferably 2-8%, and even more preferably 2-7%. The device exhibits optimal performance when the doping concentration of the organometallic complex in the host material is approximately 2%. The doping concentration is a mass percentage concentration.

[0082] Fifthly, the present invention provides a display device including the organic electroluminescent device.

[0083] In a sixth aspect, the present invention provides a lighting device including the aforementioned organic electroluminescent device.

[0084] The metal-organic complex provided by this invention can be used as a phosphorescent dopant material. The phosphorescent dopant material provided by this invention can effectively solve the problems of color purity, luminous efficiency, and lifetime of commonly used phosphorescent dopant materials. Organic electroluminescent devices prepared using the phosphorescent dopant material of this invention exhibit superior performance with high purity, high brightness, and high efficiency.

[0085] Compared with the prior art, the organometallic complex provided by the present invention has the following superior effects:

[0086] This invention introduces deuterated groups at specific positions, which can adjust the size and morphology of the spatial structure, thereby enabling the prepared organic electroluminescent devices to have the advantages of long lifespan, high efficiency, and low voltage. Detailed Implementation

[0087] The technical solution of the present invention will be described in detail below through specific embodiments. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. All equivalent changes or modifications made without departing from the spirit disclosed in the present invention should be included within the scope of the claims.

[0088] Definitions

[0089] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly used in the field to which this invention pertains. For the purposes of interpreting this specification, the following definitions will apply, and where appropriate, terms used in the singular will also include the plural forms, and vice versa.

[0090] In this invention, the halogen can be fluorine, chlorine, bromine or iodine.

[0091] In this invention, unless otherwise specified, the description of chemical elements includes the concept of isotopes with the same chemical properties. For example, hydrogen (H) includes... 1H (protium), 2 H (deuterium, D), 3 H (tritium, T), etc.; carbon (C) includes 12 C, 13 C, etc.

[0092] In the present invention, unless otherwise specified, the heteroatoms of the heteroaryl are selected from N, O, S, P, B, Si or Se, preferably N, O or S.

[0093] In the present invention, the expression Ca-Cb represents that the group has a carbon atom number of a - b. Generally speaking, unless otherwise specified, the carbon atom number does not include the carbon atom number of the substituent.

[0094] The C1-C20 can all be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0095] The C3-C20 can all be C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0096] The C2-C20 can all be C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 or C19, etc.

[0097] The C6-C30 can all be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, etc.

[0098] The C3-C30 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26 or C28, etc.

[0099] In this invention, unless otherwise specified, the C6-C30 aryl group includes monocyclic aryl and fused-ring aryl groups; the monocyclic aryl group means that the group contains at least one phenyl group, and when it contains at least two phenyl groups, the phenyl groups are linked by single bonds, including but not limited to: phenyl, biphenyl, terphenyl, tetraphenyl, etc.; the fused-ring aryl group means that the group contains at least two rings (and at least one ring is an aromatic ring), and the rings share two adjacent carbon atoms fused together, including but not limited to: Not limited to: naphthyl, anthracene, phenanthryl, indene, fluorenyl and their derivatives (9,9-dimethylfluorenyl, 9,9-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dibutylfluorenyl, 9,9-dipentylfluorenyl, 9,9-dihexylfluorenyl, 9,9-diphenylfluorenyl, 9-methyl-9-phenylfluorenyl, 9,9-dinaphthylfluorenyl, spirodifluorenyl, benzo[a]fluorenyl (benzo[A]fluorenyl, benzo[B]fluorenyl, benzo[C]fluorenyl), fluoranyl, triphenylene, pyrene, perylene, Aryl, tetraphenyl, acenaphthene, benzo[a]acenaphthene, etc. It should be noted that monocyclic aryl and fused-ring aryl groups linked by single bonds also fall under the category of aryl groups, such as phenylnaphthyl, naphthylphenyl, and binaphthyl.

[0100] In this invention, the C3-C30 heteroaryl group includes monocyclic heteroaryl or fused-ring heteroaryl. A monocyclic heteroaryl means that the molecule contains at least one heteroaryl group. When the molecule contains one heteroaryl group and other groups (such as aryl, heteroaryl, etc.), the heteroaryl group and other groups are connected by a single bond, exemplarily including but not limited to: pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, furanyl, thiopheneyl, pyrroleyl, bipyridyl, phenylpyridinyl, pyridylphenyl, etc. The term "fused-ring heteroaryl" refers to a molecule containing at least one aromatic heterocycle and one aromatic ring (aromatic heterocycle or aromatic ring), wherein the two share two adjacent atoms fused together in a group. Examples include, but are not limited to: quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothiopheneyl, isobenzofuranyl, isobenzothiopheneyl, indolyl, dibenzofuranyl, benzonaphthofuranyl (benzo[B]naphtho[2,3-D]furanyl, benzo[B]naphtho[1,2-D) Furanyl, benzo[B]naphtho[2,1-D]furanyl), dibenzothiophene, benzo[B]naphtho[2,3-D]thiophene (benzo[B]naphtho[1,2-D]thiophene, benzo[B]naphtho[2,1-D]thiophene), carbazole and its derivatives (N-phenylcarbazole, N-naphthylcarbazole, benzocarbazole, dibenzocarbazole, indolecarbazole, azacarbazole, etc.), acridineyl, phenothiazinyl, phenotoxazinyl, hydrogenated acridineyl, etc.

[0101] In this invention, specific examples of the C6-C30 arylamino group are monovalent groups obtained by substituting at least one hydrogen atom in the -NH2 group with the aforementioned aryl group, including but not limited to: phenylamino, methylphenylamino, naphthylamino, anthraceneylamino, phenanthreneamino, biphenylamino, etc. Specific examples of the C3-C30 heteroarylamino group are monovalent groups obtained by substituting at least one hydrogen atom in the -NH2 group with the aforementioned heteroaryl group, including but not limited to: pyridinylamino, pyrimidinylamino, dibenzofuranylamino, etc.

[0102] In this invention, the C6-C30 aryloxy group is a monovalent group formed by connecting the above-mentioned aryl group with O, and the C3-C30 heteroaryloxy group is a monovalent group formed by connecting the above-mentioned heteroaryl group with O.

[0103] In this invention, the C1-C20 alkyl group, preferably C1-C16 alkyl group, and more preferably C1-C10 alkyl group, includes straight-chain alkyl or branched-chain alkyl groups, and exemplary includes but is not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, tert-pentyl, neopentyl, n-hexyl, isohexyl, sec-hexyl, tert-hexyl, n-heptyl, isoheptyl, sec-heptyl, tert-heptyl, n-octyl, isooctyl, sec-octyl, tert-octyl, n-nonyl, isononyl, sec-nonyl, tert-nonyl, etc.

[0104] In this invention, specific examples of the C1-C20 alkoxy group can be exemplified by the monovalent group obtained by connecting the aforementioned alkyl group to O.

[0105] In this invention, a specific example of the C1-C20 alkylsilyl group is a monovalent group obtained by replacing at least one hydrogen in -SiH3 with the aforementioned alkyl group.

[0106] In this invention, the C3-C20 cycloalkyl group, preferably C3-C10 cycloalkyl group, includes monocycloalkyl or polycycloalkyl groups. Monocycloalkyl refers to an alkyl group containing a single ring structure, while polycycloalkyl refers to a structure composed of two or more cycloalkyl groups sharing one or more carbon atoms on a ring. Exemplary examples include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and adamantyl.

[0107] In this invention, "deuterated" refers to the replacement of at least one hydrogen (H) in a compound or group with deuterium (D). Specifically, a deuterated compound or deuterated group can be one, more, or all of the available hydrogens that have been replaced by deuterium. Specific examples of haloalkyl groups include, but are not limited to, trifluoromethyl. Specific examples of deuterated alkyl groups include, but are not limited to, deuterated methyl and deuterated ethyl. Specific examples of deuterated cycloalkyl groups include, but are not limited to, deuterated cyclopentyl and deuterated cyclohexyl. Specific examples of deuterated heteroaryl groups include, but are not limited to, deuterated dibenzofuranyl and deuterated pyridyl.

[0108] In this invention, "combination" means that one or more components of the applicable list are combined to form a known or chemically stable arrangement that can be conceived by a person skilled in the art from the applicable list. For example, combinations of alkyl / aryl and deuterium to form partially or fully deuterated alkyl / aryl groups (e.g., deuterated methyl, deuterated ethyl, deuterated tert-butyl, deuterated phenyl, deuterated biphenyl, deuterated naphthyl, etc.); combinations of halogen and alkyl to form partially or fully haloalkyl groups (e.g., trifluoromethyl, etc.); combinations of alkyl and aryl to form alkylaryl groups (methylphenyl, dimethylphenyl, trimethylphenyl, ethylphenyl, isopropylphenyl, diisopropylphenyl, tert-butylphenyl, di-tert-butylphenyl, isobutylphenyl, tert-pentylphenyl, neopentylphenyl, 2,2-dimethyl-1,3-dihydroindenyl, 1,1,3,3-tetramethyl-2,3-dihydroindenyl, 1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthyl, etc.) or arylalkyl groups (e.g., phenyl tert-butyl, etc.); combinations of halogen, alkyl and aryl to form haloarylalkyl groups, etc.

[0109] The synthetic route of the present invention is shown below. Those skilled in the art should understand that it can also be used for synthesis along other similar routes.

[0110] Synthetic Example 1: Synthesis of Ligand La-4'

[0111]

[0112] (1-1) Synthesis of intermediate S1-1:

[0113] Under nitrogen protection, starting material SM1-1 (100 mmol), trimethylsilaneacetylene (100 mmol), PdCl2(PPh3)2 (5 mmol), CuI (5 mmol), Et3N (150 mmol), and tetrahydrofuran (400 mL) were added to a dry three-necked reaction flask. The mixture was stirred and heated to 50 °C for 3 h. After the reaction was complete, the mixture was cooled to room temperature, filtered, and dried. The resulting oil was then dissolved in hexane, filtered, and dried. The resulting oil was then dissolved in dichloromethane and methanol (V / V = 1:2), and excess potassium carbonate (0.3 mol) was added. The mixture was stirred for 4 h. The organic phase was separated by extraction with water and ethanol (V / V = 1:1), dried over anhydrous magnesium sulfate, filtered, and dried to obtain intermediate S1-1 (yield 83.2%).

[0114] (1-2) Synthesis of intermediate S1-2:

[0115] Under nitrogen protection, intermediate S1-1 (80 mmol), starting material SM1-2 (80 mmol), PdCl2(PPh3)2 (4 mmol), CuI (4 mmol), Et3N (120 mmol), and tetrahydrofuran (350 mL) were added to a dry three-necked reaction flask. The mixture was stirred and heated to 50 °C for 3 h. After the reaction was complete, the mixture was cooled to room temperature, filtered, and dried. The resulting oil was then dissolved in hexane, filtered, and dried. The oil was then dissolved in dichloromethane and methanol (V / V = 1:2), and excess potassium carbonate (0.3 mol) was added. The mixture was stirred for 4 h. The organic phase was separated by extraction with water and ethanol (V / V = 1:1), dried over anhydrous magnesium sulfate, filtered, and dried to obtain intermediate S1-2 (yield 80.7%).

[0116] (1-3) Synthesis of ligand La-4':

[0117] Under nitrogen protection, intermediate S1-2 (60 mmol), tert-butylamine (72 mmol), AgNO3 (6 mmol), and MeOD (300 mL) were added to a dry three-necked reaction flask. The mixture was stirred and heated to 65 °C for 40 h. After the reaction was complete, the mixture was cooled to room temperature, water was added, and the mixture was filtered. The solution was washed with water and ethanol, filtered again, dried, dissolved in dichloromethane, and purified by column chromatography to give ligand La-4' (yield 86.5%). MS (m / e) of ligand La-4': 352.46.

[0118] Synthesis Example 2: Synthesis of Ligand La-26'

[0119]

[0120] (2-1) Synthesis of intermediate S2-1:

[0121] Under nitrogen protection, starting material SM2-1 (100 mmol), trimethylsilaneacetylene (100 mmol), PdCl2(PPh3)2 (5 mmol), CuI (5 mmol), Et3N (150 mmol), and tetrahydrofuran (400 mL) were added to a dry three-necked reaction flask. The mixture was stirred and heated to 50 °C for 3 h. After the reaction was complete, the mixture was cooled to room temperature, filtered, and dried. The resulting oil was then dissolved in hexane, filtered, and dried. The resulting oil was then dissolved in dichloromethane and methanol (V / V = 1:2), and excess potassium carbonate (0.3 mol) was added. The mixture was stirred for 4 h. The organic phase was separated by extraction with water and ethanol (V / V = 1:1), dried over anhydrous magnesium sulfate, filtered, and dried to obtain intermediate S2-1 (yield 81.2%).

[0122] (2-2) Synthesis of intermediate S2-2:

[0123] Under nitrogen protection, intermediate S2-1 (80 mmol), starting material SM2-2 (80 mmol), PdCl2(PPh3)2 (4 mmol), CuI (4 mmol), Et3N (120 mmol), and CH3CN (350 mL) were added to a dry three-necked reaction flask. The mixture was stirred and heated to 70 °C for 5 h. After the reaction was complete, the mixture was cooled to room temperature, filtered, and dried. The resulting oil was then dissolved in hexane, filtered, and dried. The resulting oil was then dissolved in dichloromethane and methanol (V / V = 1:2), and excess potassium carbonate (0.3 mol) was added. The mixture was stirred for 4 h. The organic phase was separated by extraction with water and ethanol (V / V = 1:1), dried over anhydrous magnesium sulfate, filtered, and dried to obtain intermediate S2-2 (yield 78.3%).

[0124] (2-3) Synthesis of ligand La-26':

[0125] Following the synthesis method described in Example 1 (1-3), simply replacing intermediate S1-2 with intermediate S2-2 yields ligand La-26'. The MS (m / e) of ligand La-26' is 393.02.

[0126] Synthesis Example 3: Synthesis of Ligand La-58'

[0127]

[0128] (3-1) Synthesis of intermediate S3-1:

[0129] Under nitrogen protection, diisopropylamine (130 mmol) and tetrahydrofuran (50 mL) were added to a dry three-necked reaction flask, stirred, and cooled to -78 °C. Then, a hexane solution of n-butyllithium (110 mmol, 2.3 M) was added dropwise, and the temperature was maintained while stirring for 1 h. Then, the starting material SM3-1 (100 mmol) was slowly added, and the mixture was stirred for 0.5 h. Then, N,N-dimethylformamide (200 mL) was added dropwise, and the temperature was raised to 0 °C while stirring. Hydrochloric acid (50 mL, 1 M) was added dropwise. After the reaction was completed, the mixture was allowed to cool to room temperature naturally, extracted with ethyl acetate, washed with water, and the organic phase was collected. The phase was dried over anhydrous magnesium sulfate and recrystallized to give intermediate S3-1 (yield 64.8%). (3-2) Synthesis of ligand La-58':

[0130] Following the synthesis methods in (1-2) and (1-3) of Synthesis Example 1, the ligand La-58' can be obtained by simply replacing the raw material SM1-2 with intermediate S3-1. The MS (m / e) of ligand La-58' is 464.10.

[0131] Synthesis Example 4: Synthesis of ligand La-64'

[0132]

[0133] Following the synthesis methods in (2-2) and (2-3) of Synthesis Example 2, only intermediate S2-1 was replaced with intermediate S1-1, and starting material SM2-2 was replaced with starting material SM4-1 to obtain ligand La-64'. The MS (m / e) of ligand La-64' is 368.32. Synthesis Example 5: Synthesis of ligand La-78'

[0134]

[0135] (5-1) Synthesis of intermediate S5-1:

[0136] Referring to the synthesis method of Synthesis Example 3 (3-1), intermediate S5-1 can be obtained by simply replacing raw material SM3-1 with raw material SM5-1.

[0137] (5-2) Synthesis of ligand La-78':

[0138] Following the synthesis methods of Examples 2 (2-2) and (2-3), only intermediate S2-1 was replaced with intermediate S1-1, and starting material SM2-2 was replaced with intermediate S5-1 to obtain ligand La-78'. The MS (m / e) of ligand La-78' is 444.54.

[0139] Synthesis Example 6: Synthesis of Ligand La-14'

[0140]

[0141] Following the synthesis method of Example 1, simply replacing raw material SM1-1 with raw material SM6-1 yields ligand La-14'. The MS (m / e) of ligand La-14' is 338.31.

[0142] Synthesis Example 7: Synthesis of Compound M3

[0143]

[0144] (7-1) Synthesis of intermediate S7-1:

[0145] Under nitrogen protection, 15 mmol of starting material SM7-1, 6 mmol of iridium trichloride trihydrate, 45 mL of ethylene glycol monoethyl ether, and 15 mL of water were added to a dry three-necked reaction flask. The mixture was heated to 110 °C and refluxed for 24 h with stirring. After the reaction was completed, the mixture was cooled to room temperature, 10 mL of water was added, and the mixture was stirred for 10 min. The mixture was then filtered, washed successively with water and ethanol, and dried to obtain intermediate S7-1 (yield 77.3%).

[0146] (7-2) Synthesis of intermediate S7-2:

[0147] Under nitrogen protection, intermediate S7-1 (2.5 mmol) and dichloromethane (50 mL) were added to a dry three-necked reaction flask and stirred thoroughly. Then, a methanol solution of silver trifluoromethanesulfonate (6.25 mmol) (50 mL) was added, and the mixture was stirred for 24 h in the dark. After the reaction was completed, the mixture was cooled to room temperature, filtered through diatomaceous earth, and the filtrate was evaporated to dryness to obtain intermediate S7-2. This intermediate S7-2 was used directly in the next reaction without further treatment.

[0148] (7-3) Synthesis of compound M3:

[0149] Under nitrogen protection, intermediate S7-2 (6.9 mmol), ligand La-4' (21 mmol), and ethanol (150 mL) were added to a dry three-necked reaction flask, and the mixture was heated to reflux with stirring for 36 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, dissolved in dichloromethane, and purified by column chromatography to give compound M3 (yield 60.1%). MS (m / e) of compound M3: 852.54.

[0150] Synthesis Example 8: Synthesis of Compound M34

[0151]

[0152] Following the synthetic method of Example 7, only the starting material SM7-1 was replaced with starting material SM8-1, and the ligand La-4' was replaced with ligand La-26', to obtain compound M34. The MS (m / e) of compound M34 is 921.11.

[0153] Synthesis Example 9: Synthesis of Compound M90

[0154]

[0155] Following the synthetic method of Example 7, only the starting material SM7-1 was replaced with starting material SM9-1, and the ligand La-4' was replaced with ligand La-58', to obtain compound M90. The MS (m / e) of compound M90 is 980.86.

[0156] Synthesis Example 10: Synthesis of Compound M116

[0157]

[0158] Following the synthetic method of Example 7, only the starting material SM7-1 was replaced with starting material SM10-1, and the ligand La-4' was replaced with ligand La-64', to obtain compound M116. The MS (m / e) of compound M116 is 1054.03.

[0159] Synthesis Example 11: Synthesis of Compound M144

[0160]

[0161] (11-1) Synthesis of intermediate S11-1:

[0162] Under nitrogen protection, ligand La-78' (25 mmol), iridium trichloride trihydrate (10 mmol), ethylene glycol monoethyl ether (90 mL), and water (30 mL) were added to a dry three-necked reaction flask. The mixture was heated to 110 °C and refluxed for 24 h with stirring. After the reaction was completed, the mixture was cooled to room temperature, water (50 mL) was added, and the mixture was stirred for 10 min. The mixture was then filtered, washed successively with water and ethanol, and dried to obtain intermediate S11-1 (yield 58.1%).

[0163] (11-2) Synthesis of compound M144:

[0164] Under nitrogen protection, intermediate S11-1 (3 mmol), starting material SM11-1 (9 mmol), anhydrous sodium carbonate (12 mmol), and ethylene glycol monoethyl ether (100 mL) were added to a dry three-necked reaction flask. The mixture was stirred and refluxed in an oil bath at 120 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed with ethanol, dried, dissolved in dichloromethane, purified by column chromatography, washed with dichloromethane as eluent, and the solvent was removed to obtain compound M144 (yield 34.2%). MS (m / e) of compound M144: 1178.62. Synthesis Example 12: Synthesis of compound M147

[0165]

[0166] Following the synthetic method of Example 11, only the ligand La-78' was replaced with ligand La-4', and the starting material SM11-1 was replaced with starting material SM12-1, to obtain compound M147. The MS (m / e) of compound M147 is 1106.79.

[0167] Synthesis Example 13: Synthesis of Compound M164

[0168]

[0169] Following the synthetic method of Example 12, compound M164 was obtained by simply replacing ligand La-4' with ligand La-64'. The MS (m / e) of compound M164 was 1138.23.

[0170] Synthesis Example 14: Synthesis of Compound M178

[0171]

[0172] Following the synthetic method of Example 11, only the ligand La-78' was replaced with ligand La-26', and the starting material SM11-1 was replaced with starting material SM14-1, to obtain compound M178. The MS (m / e) of compound M178 is 1230.46.

[0173] Synthesis Example 15: Synthesis of Compound M197

[0174]

[0175] Following the synthetic method of Example 11, only the ligand La-78' was replaced with ligand La-14', and the starting material SM11-1 was replaced with starting material SM15-1, to obtain compound M197. The MS (m / e) of compound M197 is 1102.23.

[0176] Synthesis Example 16: Synthesis of Compound M234

[0177]

[0178] Following the synthetic method of Example 11, only the ligand La-78' was replaced with ligand La-58', and the starting material SM11-1 was replaced with starting material SM16-1, to obtain compound M234. The MS (m / e) of compound M234 is 1442.98.

[0179] This invention provides exemplary methods for synthesizing the above-mentioned compounds. Other compounds for which no specific synthesis method is provided can also be prepared using similar methods, requiring only the replacement of raw materials. These methods will not be elaborated here. Alternatively, those skilled in the art can prepare these compounds using other methods in the prior art.

[0180] The following are examples of organic electroluminescent devices prepared according to the present invention using representative compounds of the present invention:

[0181] This embodiment provides an OLED device with the following structure (materials and thicknesses of each functional layer): ITO / HATCN (10nm) / HT01 (60nm) / TAPC (10nm) / RH:2% of the present invention's organometallic complex (40nm) / TPBI (5nm) / ET01:LiQ (6:4) (35nm) / LiQ (1nm) / Al.

[0182] The molecular structures of each functional layer material are as follows:

[0183]

[0184] Device Example 1:

[0185] (1) The glass plate coated with ITO transparent conductive layer was ultrasonically treated in commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in acetone:ethanol mixed solvent (volume ratio 1:1), baked in a clean environment until the moisture was completely removed, cleaned with ultraviolet light and ozone, and bombarded with low-energy cation beam.

[0186] (2) Place the glass substrate with the anode into the vacuum chamber and evacuate to 5 × 10⁻⁶. -5 ~9×10 -3 Pa, HATCN is vacuum-deposited as a hole injection layer on the above-mentioned anode layer film at a deposition rate of 0.1 nm / s and a total film thickness of 10 nm; then, the first hole transport layer HT01 is deposited at a deposition rate of 0.1 nm / s and a thickness of 60 nm; then, the second hole transport layer TAPC is deposited at a deposition rate of 0.1 nm / s and a film thickness of 10 nm.

[0187] (3) An EML is vacuum-deposited on the hole transport layer as the light-emitting layer of the device. The EML includes the host material RH and the phosphorescent doping material compound M3 of the present invention, with a doping concentration of 2%, to form the organic light-emitting layer of the device. The evaporation rates are 0.098 nm / s and 0.002 nm / s, respectively, and the total film thickness is 40 nm. Then, 5 nm of TPBI is deposited to form a hole blocking layer at a evaporation rate of 0.1 nm / s.

[0188] (4) Then, ET01:LiQ with a mass ratio of 6:4 is deposited on the hole blocking layer as the electron transport material of the device electron transport layer. The deposition rates are 0.06 nm / s and 0.04 nm / s, respectively, and the total film thickness is 35 nm.

[0189] (5) A 1 nm thick LiQ layer is vacuum-deposited on the electron transport layer as an electron injection layer, and a 150 nm thick Al layer is deposited as the cathode of the device.

[0190] Device Examples 2-10, Device Comparative Examples 1-3:

[0191] An organic electroluminescent device is disclosed, which differs from device example 1 only in that the phosphorescent doping material of the light-emitting layer is one of the compounds shown in Table 1; the other layers, thicknesses, materials and preparation methods are the same as those in device example 1.

[0192]

[0193] Performance testing:

[0194] At a current density of 10 mA / cm 2 The voltage (V) and current efficiency (cd / A) of the organic electroluminescent device were measured under initial conditions, at a current density of 50 mA / cm². 2 The time it took for the brightness of the organic electroluminescent device to decay to 95% under initial conditions was measured, i.e., lifetime (LT95, h). To better illustrate the data comparison, the voltage, current efficiency, and lifetime of Comparative Example 1 were set to 1.00, and the voltage, current efficiency, and lifetime of other devices were the ratios of their respective test values ​​to the test values ​​of Comparative Example 1 (i.e., relative voltage, relative current efficiency, and relative lifetime).

[0195] Table 1

[0196] Device Phosphorescent dopant material Relative voltage Relative current efficiency Relative lifetime Device example 1 M3 0.91 1.14 1.07 Device example 2 M34 0.94 1.17 1.14 Device example 3 M90 0.92 1.10 1.19 Device example 4 M116 0.91 1.16 1.15 Device example 5 M144 0.89 1.19 1.10 Device example 6 M147 0.87 1.21 1.14 Device example 7 M164 0.86 1.20 1.15 Device example 8 M178 0.88 1.17 1.18 Device example 9 M197 0.90 1.13 1.13 Device example 10 M234 0.90 1.15 1.12 Device comparative example 1 D1 1.00 1.00 1.00 Device comparative example 2 D2 1.03 1.02 1.01 Device comparative example 3 D3 0.98 0.88 0.91

[0197] The results above show that, compared with compounds D1, D2 and D3, the current efficiency of the corresponding organic electroluminescent devices prepared by the metal-organic complexes provided by the present invention is improved, the voltage is reduced, and the lifetime is significantly extended.

[0198] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A ligand compound having the structure shown in Formula I: in, X1 and X2 are each independently selected from any one of single bonds, O, S, and Se; at most one of X1 and X2 is a single bond; Z1, Z2, Z3, Z4, Z5, and Z6 are each independently selected from CR. Z Or N; U1, U2, U3, and U4 are each independently selected from CR U Or N; R Z R U Each is independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; the R Z R U Each group can independently form a ring without being connected to adjacent groups or by chemical bonds. The R Z R U The substituents described herein are each independently selected from any one or a combination of at least two of the following: deuterium, halogen, cyano, nitro, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkylsilyl, C3-C20 cycloalkyl, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 aryl, and C3-C30 heteroaryl.

2. The ligand compound according to claim 1, characterized in that, The ligand compound has a structure as shown in Formula I-1 or Formula I-2: Wherein, the definitions of Z1, Z2, Z3, Z4, Z5, Z6, U1, U2, U3, and U4 are the same as those in Equation I; X1 and X2 are each independently selected from O, S, or Se; preferably O or S; Preferably, at most one of Z1, Z2, Z3, Z4, Z5, and Z6 is selected from N; Preferably, Z1, Z2, Z3, Z4, Z5, and Z6 are each independently selected from CR. Z ; Preferably, R Z Each group is independently selected from any one or at least two combinations of hydrogen, deuterium, halogen, cyano, nitro, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 alkylsilyl, C3-C10 cycloalkyl, C6-C20 arylamino, C3-C20 heteroarylamino, C6-C20 aryloxy, C3-C20 heteroaryloxy, C6-C20 aryl, and C3-C20 heteroaryl; more preferably selected from any one or at least two combinations of hydrogen, deuterium, halogen, cyano, C1-C10 alkyl, C3-C10 cycloalkyl, C6-C20 aryl, and C3-C20 heteroaryl; even more preferably selected from hydrogen, deuterium, F, CN, or any of the following groups: Preferably, at most one of U1, U2, U3, and U4 is selected from N; Preferably, U1, U2, U3, and U4 are each independently selected from CR. U ; Preferably, R U Each group is independently selected from any one or a combination of at least two of hydrogen, deuterium, halogen, cyano, nitro, C1-C10 alkyl, C3-C10 cycloalkyl, C6-C20 aryl, and C3-C20 heteroaryl; more preferably selected from hydrogen, F, CN, or any of the following groups:

3. A metal-organic complex comprising a metal atom M and a first ligand La, wherein the relative atomic mass of the metal atom M is greater than 40, wherein... The first ligand La has a structure as shown in Formula II: Wherein, the dashed line represents the binding site between the first ligand La and the metal atom M; X1 and X2 are each independently selected from any one of single bonds, O, S, and Se; at most one of X1 and X2 is a single bond; Z1, Z2, Z3, Z4, Z5, and Z6 are each independently selected from CR. Z Or N; U1, U2, U3, and U4 are each independently selected from CR U Or N; R Z R U Each is independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; the R Z R U Each group can independently form a ring without being connected to adjacent groups or by chemical bonds. The R Z R U The substituents described herein are each independently selected from any one or a combination of at least two of the following: deuterium, halogen, cyano, nitro, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkylsilyl, C3-C20 cycloalkyl, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 aryl, and C3-C30 heteroaryl.

4. The organometallic complex according to claim 3, characterized in that, The first ligand La has a structure as shown in Formula II-1 or Formula II-2: Wherein, the definitions of Z1, Z2, Z3, Z4, Z5, Z6, U1, U2, U3, and U4 are the same as those in Equation II; X1 and X2 are each independently selected from O, S, or Se; preferably O or S; Preferably, at most one of Z1, Z2, Z3, Z4, Z5, and Z6 is selected from N; Preferably, Z1, Z2, Z3, Z4, Z5, and Z6 are each independently selected from CR. Z ; Preferably, R Z Each group is independently selected from any one or at least two combinations of hydrogen, deuterium, halogen, cyano, nitro, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 alkylsilyl, C3-C10 cycloalkyl, C6-C20 arylamino, C3-C20 heteroarylamino, C6-C20 aryloxy, C3-C20 heteroaryloxy, C6-C20 aryl, and C3-C20 heteroaryl; more preferably selected from any one or at least two combinations of hydrogen, deuterium, halogen, cyano, C1-C10 alkyl, C3-C10 cycloalkyl, C6-C20 aryl, and C3-C20 heteroaryl; even more preferably selected from hydrogen, deuterium, F, CN, or any of the following groups: Preferably, at most one of U1, U2, U3, and U4 is selected from N; Preferably, U1, U2, U3, and U4 are each independently selected from CR. U ; Preferably, R U Each group is independently selected from any one or a combination of at least two of hydrogen, deuterium, halogen, cyano, nitro, C1-C10 alkyl, C3-C10 cycloalkyl, C6-C20 aryl, and C3-C20 heteroaryl; more preferably selected from hydrogen, F, CN, or any of the following groups:

5. The organometallic complex according to claim 3 or 4, characterized in that, The first ligand La is selected from the group consisting of the following structures:

6. The organometallic complex according to any one of claims 3-5, characterized in that, The organometallic complex further includes a second ligand and / or a third ligand; Preferably, the organometallic complex has M(La). i (Lb) j (Lc) k The structure is as follows: La, Lb, and Lc are the first, second, and third ligands coordinated with the metal atom M, respectively; i is selected from 1, 2, or 3; j is selected from 0, 1, or 2; k is selected from 0, 1, or 2, and the sum of i, j, and k equals the oxidation state of the metal atom M; when i is greater than or equal to 2, multiple Las may be the same or different; when j is equal to 2, two Lbs may be the same or different; when k is equal to 2, two Lcs may be the same or different. Preferably, the second ligand Lb and the third ligand Lc are each independently selected from structures shown in either Formula III or Formula IV: Among them, R1-R 15 Each of the following is independently selected from hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryloxy, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; the R1-R 15 Each group can independently form a ring without being connected to adjacent groups or by chemical bonds. The R1-R 15 The substituents described herein are each independently selected from any one or a combination of at least two of the following: deuterium, halogen, cyano, nitro, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkylsilyl, C3-C20 cycloalkyl, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C30 aryl, and C3-C30 heteroaryl. Preferably, the second ligand Lb and the third ligand Lc are each independently selected from any one of the following structures: The dashed lines represent the binding sites of the second ligand Lb or the third ligand Lc with the metal atom M.

7. The organometallic complex according to any one of claims 3-6, characterized in that, The metal atom M is selected from Cu, Pt, Au, Ru, Pd, Rh, or Ir; preferably, the metal atom M is selected from Pt or Ir; preferably, the metal atom M is selected from Ir. Preferably, the organometallic complex has the structure of Ir(La)3 or Ir(La)2(Lb) or Ir(La)(Lb)2 or Ir(La)2(Lc) or Ir(La)(Lb)(Lc); more preferably, it has the structure of Ir(La)(Lb)2 or Ir(La)2(Lc); Preferably, the organometallic complex is selected from the group consisting of the following compounds: wherein compounds M1 to M120 have the structure Ir(La)(Lb)2, wherein the two Lb are identical, and La and Lb are respectively selected from the structures listed in the table below: Compounds M121 to M240 have the structure Ir(La)2(Lc), where the two La values ​​are identical, and the La and Lc values ​​correspond to the structures listed in the table below:

8. The use of the organometallic complex according to any one of claims 3-7 in organic electronic devices.

9. An organic electroluminescent device, the organic electroluminescent device comprising a light-emitting layer, the light-emitting layer comprising any one of the metal-organic complexes of claims 3-7; Preferably, the light-emitting layer further includes a host material; More preferably, the doping concentration of the organometallic complex in the host material is 1-12%, more preferably 2-8%, and even more preferably 2-7%.

10. A display / lighting device comprising the organic electroluminescent device of claim 9.

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