Organometallic compound and organic electroluminescent device including same

Abstract

The organometallic compound represented by formula (1) provides an organic electroluminescent element which is driven at a low voltage, has a long lifetime, and is highly efficient, and a device including the organic electroluminescent element. In formula (1), R1 to R20, X1 to X2, a1 to a2, M, L1, and cy1 to cy2 are completely the same as defined in the description. # imgabs0 #

Description

Technical Field

[0001] Embodiments of the present invention generally relate to an organometallic compound and an organic electroluminescent device including the organometallic compound. Background Art

[0002] The principle of organic electroluminescent devices is to efficiently recombine and de-excite electrons injected from the cathode and holes injected from the anode in the light-emitting layer to form photons. Metal organic compounds have 100% exciton utilization due to the heavy metal effect, so they are a highly efficient luminescent material.

[0003] Prior art literature

[0004] Patent document 1: U.S. Patent Publication No. US20240298518A1

[0005] Patent document 2: China Publication No. CN112851638A

[0006] Patent document 3: China Publication No. CN114195829A

[0007] Patent document 4: U.S. Patent Publication No. US20240206208A1

[0008] Patent Document 5: Korean Publication No. KR2023000424A

[0009] Patent Document 6: China Publication No. CN115260250A

[0010] Patent Document 7: U.S. Patent Publication No. US20210347798A1 Summary of the invention

[0011] Problems to be solved by the present invention

[0012] In the past, phosphorescent compounds have been widely reported as a means to improve device performance, but the device performance still does not meet the requirements.

[0013] The present invention is made to solve the above-mentioned problems, and aims to provide a novel organometallic compound with low voltage drive, long life, high efficiency and high color purity, and an organic electroluminescent device structure containing the compound.

[0014] Means used to solve problems

[0015] The present inventors have conducted repeated studies to achieve the above-mentioned object and have found that an organometallic compound and a device structure represented by the following formula (1) can significantly improve the performance of a blue light device.

[0016] In one embodiment, the present invention provides an organometallic compound represented by formula (1) (hereinafter sometimes referred to as compound (1)).

[0017] [Chemistry 1]

[0018]

[0019] In formula (1),

[0020] M is platinum, palladium, iridium, gold, silver, nickel, manganese, zinc or copper;

[0021] Two adjacent R1 to R3 are single bonds bonded to the structural formula T1;

[0022] R1 to R3 which are not single bonds to the structural formula T1 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or an unsubstituted heterocyclic group having 1 to 60 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, -C(Ra1)(Ra2)(Ra3), -Si(Ra1)(Ra2)(Ra3), -N(Ra1)(Ra2), -B(Ra1)(Ra2), -C(=O)(Ra1), -S(=O)(Ra1), or -P(=O)(Ra1)(Ra2),

[0023] At least one set of two adjacent ones of R4 to R9 is a single bond bonded to the structural formula T2;

[0024] R4 to R14 which are not single bonds to the structural formula T2 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or an unsubstituted heterocyclic group having 1 to 60 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, -C(Ra4)(Ra5)(Ra6), -Si(Ra4)(Ra5)(Ra6), -N(Ra4)(Ra5), -B(Ra4)(Ra5), -C(=O)(Ra4), -S(=O)(Ra4), or -P(=O)(Ra4)(Ra5),

[0025] Among them, two adjacent R4 to R9 selected from the single bonds that are not bonded to the structural formula T2 are independently represented by hydrogen atoms, deuterium atoms or the substituents, or are bonded to each other to form a ring structure, and the ring structure is a substituted or unsubstituted aromatic hydrocarbon ring with 6 to 18 ring carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon ring with 5 to 18 ring carbon atoms, a substituted or unsubstituted aromatic heterocycle with 5 to 18 ring atoms, or a substituted or unsubstituted aliphatic heterocycle with 5 to 18 ring atoms;

[0026] Ring cy1 is selected from an aryl group having 6 to 60 carbon atoms or a heterocyclic group having 1 to 60 carbon atoms;

[0027] Ring cy2 is selected from an aryl group having 6 to 60 carbon atoms or a heterocyclic group having 1 to 60 carbon atoms, and there is a coordination bond between ring cy2 and M;

[0028] a1 and a2 are each independently an integer from 0 to 10;

[0029] R10 to R19 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from the group consisting of a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted heterocyclic group having 1 to 60 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, -C(Ra7)(Ra8)(Ra9), -Si(Ra7)(Ra8)(Ra9), -N(Ra7)(Ra8), -B(Ra7)(Ra8), -C(=O)(Ra7), -S(=O)(Ra7), or -P(=O)(Ra7)(Ra8);

[0030] Wherein, two adjacent ones selected from R10 to R19 are independently represented by hydrogen atoms, deuterium atoms or the substituents, or are bonded to each other to form a ring structure, and the ring structure is a substituted or unsubstituted aromatic hydrocarbon ring with 6 to 18 ring carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon ring with 5 to 18 ring carbon atoms, a substituted or unsubstituted aromatic heterocycle with 5 to 18 ring atoms, or a substituted or unsubstituted aliphatic heterocycle with 5 to 18 ring atoms;

[0031] L1 is selected from -O-, -S-, -Se-, -N(Ra10)-, -B(Ra10)-, -P(Ra10)-, -P(=O)(Ra10)-, -S(=O)2-, -S(=O)(Ra10)(Ra11)-, -C(=O)-, -C(Ra10)(Ra11)-, -Si(Ra10)(Ra11)-, or Ge(Ra10)(Ra11)-;

[0032] X1 and X2 are each independently -O-, -C(Ra12)(Ra13)-, -S-, -Si(Ra12)(Ra13)-, or -N(Ra12)-;

[0033] Ra1 to Ra13 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from the group consisting of a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted heterocyclic group having 1 to 60 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, or a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms,

[0034] Wherein, two adjacent ones selected from Ra1 to Ra13 independently represent a hydrogen atom, a deuterium atom or the above-mentioned substituents, or are bonded to each other to form a ring structure, wherein the ring structure is a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 18 ring carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon ring having 5 to 18 ring carbon atoms, a substituted or unsubstituted aromatic heterocycle having 5 to 18 ring atoms, or a substituted or unsubstituted aliphatic heterocycle having 5 to 18 ring atoms;

[0035] "*" indicates the positions where two adjacent ones of R1 to R9 form single bonds with the structural formulae T1 and T2.

[0036] In another embodiment, the present invention provides a material for an organic electroluminescent device comprising the organometallic compound (1).

[0037] In another embodiment, the present invention provides a device comprising the compound (1), comprising a first electrode, a second electrode, an organic layer opposite to the first electrode, and arranged between the first electrode and the second electrode, wherein the organic layer comprises a light-emitting layer, and the light-emitting layer comprises the organometallic compound (1) as a material among phosphorescent dopants or phosphorescent sensitizers.

[0038] Effects of the Invention

[0039] The present invention aims to provide an organic metal compound (1) having the functions of improving driving voltage, life, efficiency and color purity at the same time, and a structure of an organic electroluminescent device comprising the compound (1). BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic diagram of an OLED device structure 100 comprising compound (1) as a phosphorescent dopant;

[0041] Figure 2 is a schematic diagram of an OLED device structure 200 comprising compound (1) as a phosphorescent sensitizer;

[0042] Figure 3 is a schematic diagram of energy transfer in an OLED device structure comprising compound (1) as a phosphorescent sensitizer; DETAILED DESCRIPTION

[0043] To illustrate the technical advantages of the present invention in detail, specific embodiments will be described in detail. It should be noted that the embodiments shown below are only suitable for illustrating the present application and do not limit the scope of the present application.

[0044] The description of "substituted or unsubstituted CC group with carbon number AA to BB" in this specification, wherein "carbon number AA to BB" indicates the carbon number of the CC group when it is unsubstituted, and does not include the carbon number of the substituent when substitution occurs. The description of "substituted or unsubstituted CC ring group with carbon number AA to BB" in this specification, wherein "carbon number AA to BB" indicates the number of carbon atoms in the CC ring group, and does not include the number of other heteroatoms, and the "ring structure" in the "forming ring structure" described in the specification can be a monocyclic compound, a condensed ring compound, a bridged compound, a carbocyclic compound, or a heterocyclic compound, and the carbon atoms on the substituent are not counted in the ring carbon number. "Heavy hydrogen" uniformly refers to hydrogen isotopes with different numbers of neutrons, which can be protium, deuterium, or tritium. "*" refers to the binding site where one group binds to another group.

[0045] An organometallic compound (1) according to one embodiment of the present specification is represented by the following formula (1).

[0046] [Chemistry 2]

[0047]

[0048] Two adjacent R1 to R3 are single bonds bonded to structural formula T1.

[0049] That is, compound (1) is a compound in which R1 and R2 are single bonds to structural formula T1, or a compound in which R2 and R3 are single bonds to structural formula T2.

[0050] R1 to R3 which are not single bonds to the structural formula T1 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from a cyano group; a halogen atom; a nitro group; a nitro group; a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms; a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, preferably 2 to 30 carbon atoms; a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, preferably 2 to 30 carbon atoms; a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms; a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, preferably 3 to 30 carbon atoms; a substituted or unsubstituted cycloalkyl group having 6 to 60 carbon atoms; , an aryl group preferably having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms, -C(Ra1)(Ra2)(Ra3), -Si(Ra1)(Ra2)(Ra3), -N(Ra1)(Ra2), -B(Ra1)(Ra2), -C(=O)(Ra1), -S(=O)(Ra1), or -P(=O)(Ra1)(Ra2).

[0051] At least one set of two adjacent ones of R4 to R9 is a single bond to structural formula T2.

[0052] That is, compound (1) is a compound in which R4 and R5 are single bonds bonded to structural formula T2, a compound in which R6 and R7 are single bonds bonded to structural formula T2, a compound in which R7 and R8 are single bonds bonded to structural formula T2, or a compound in which R8 and R9 are single bonds bonded to structural formula T2.

[0053] R4 to R9 which are not single bonds to the structural formula T2 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from a cyano group; a halogen atom; a nitro group; a nitro group; a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms; a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, preferably 2 to 30 carbon atoms; a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, preferably 2 to 30 carbon atoms; a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms; a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, preferably 3 to 30 carbon atoms; a substituted or unsubstituted cycloalkyl group having 6 to 60 carbon atoms; , an aryl group preferably having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms, -C(Ra4)(Ra5)(Ra6), -Si(Ra4)(Ra5)(Ra6), -N(Ra4)(Ra5), -B(Ra4)(Ra5), -C(=O)(Ra4), -S(=O)(Ra4), or -P(=O)(Ra4)(Ra5),

[0054] Among them, two adjacent groups selected from R4 to R9 are independently represented by a deuterium atom, a hydrogen atom or the substituent, or the two adjacent groups are bonded to each other to form a ring structure, and the ring structure is a substituted or unsubstituted aryl group having 6 to 60 carbon atoms or a substituted or unsubstituted heterocyclic group having 1 to 60 carbon atoms. That is, the two adjacent groups do not form a ring structure but are independently represented by a deuterium atom, a hydrogen atom or the substituent, or are bonded to each other to form a ring structure.

[0055] In one embodiment of the present invention, two adjacent groups of R1 to R3 are single bonds bonded to structural formula T1, and at least one group of two adjacent groups of R4 to R9 are single bonds bonded to structural formula T2, and compound (1) is represented by any one of the following formulas (2) to (40).

[0056] [Chemistry 3]

[0057]

[0058]

[0059]

[0060] R10 to R24 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from a cyano group; a halogen atom; a nitro group; a nitro group; a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms; a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, preferably 2 to 30 carbon atoms; a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, preferably 2 to 30 carbon atoms; a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms; a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, preferably 3 to 30 carbon atoms; a substituted or unsubstituted cycloalkyl group having 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms; 30, an aryl group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms, -C(Ra7)(Ra8)(Ra9), -Si(Ra7)(Ra8)(Ra9), -N(Ra7)(Ra8), -B(Ra7)(Ra8), -C(═O)(Ra7), -S(═O)(Ra7), or -P(═O)(Ra7)(Ra8),

[0061] Among them, two adjacent groups selected from R10 to R24 are independently represented by a deuterium atom, a hydrogen atom or the substituent, or the two adjacent groups are bonded to each other to form a ring structure, and the ring structure is a substituted or unsubstituted aryl group having 6 to 60 carbon atoms or a substituted or unsubstituted heterocyclic group having 1 to 60 carbon atoms. That is, the two adjacent groups do not form a ring structure but are independently represented by a deuterium atom, a hydrogen atom or the substituent, or are bonded to each other to form a ring structure.

[0062] Hereinafter, each symbol of formulae (1) to (40), formulae (41) to (44) described later, cy1-1 to cy1-9, and cy2-1 to cy2-30 will be described in detail.

[0063] The ring cy1 is selected from an aryl group having 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms, or a heterocyclic group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms. As a specific example, the ring cy1 can be represented by the formulae cy1-1 to cy1-9, but is not limited thereto.

[0064] [Chemistry 4]

[0065]

[0066] In one embodiment, ring cy1 is represented by the formula cy1-1. In another embodiment, ring cy1 is represented by one of the formulas cy1-2 to cy1-9 other than cy1-1. The definition of X4 can be understood by referring to the description of the corresponding X1 to X3 in the above formulas (1) to (40).

[0067] The ring cy2 is selected from an aryl group having 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms, or a heterocyclic group having 1 to 60 carbon atoms, preferably 1 to 30 carbon atoms, and the ring cy2 is coordinated with M. Specific examples of the ring cy2 may be represented by any one of the formulae cy2-1 to cy2-30, but are not limited thereto.

[0068] [Chemistry 5]

[0069]

[0070] In one embodiment, the ring cy2 is represented by cy2-25, and the definition of R25 is the same as the description of the corresponding substituents R10 to R24 in the above formulas (1) to (40). In another embodiment, the ring cy2 is represented by any one of cy2-1 to cy2-24 and cy2-26 to cy2-30 other than the formula cy2-25, and the definition of X5 can be understood with reference to the corresponding substituents X1 to X3 in the above formulas (1) to (40).

[0071] a1 is independently selected from integers of 0 to 10. In one embodiment of the present invention, a1 is 0, i.e., ring cy1 contains no substituents other than hydrogen atoms or deuterium atoms. In another embodiment of the present invention, a1 is an integer of 1 to 10, i.e., ring cy1 contains substituents other than hydrogen atoms or deuterium atoms.

[0072] a2 is independently selected from integers of 0 to 10. In one embodiment of the present invention, a2 is 0, i.e., ring cy2 contains no substituents other than hydrogen atoms or deuterium atoms. In another embodiment of the present invention, a2 is an integer of 1 to 10, i.e., ring cy2 contains substituents other than hydrogen atoms or deuterium atoms.

[0073] L1 is selected from -O-, -S-, -Se-, -N(Ra10)-, -B(Ra10)-, -P(Ra10)-, -P(=O)(Ra10)-, -S(=O)2-, -S(=O)(Ra10)(Ra11)-, -C(=O)-, -C(Ra10)(Ra11)-, -Si(Ra10)(Ra11)-, or Ge(Ra10)(Ra11)-, and is preferably -O-.

[0074] X1 and X2 are each independently -O-, -C(Ra12)(Ra13)-, -S-, -Si(Ra12)(Ra13)-, or -N(Ra12)-.

[0075] In one embodiment of the present invention, X1 and X2 are both -O-. In another embodiment of the present invention, X1 and X2 are different from each other and are each independently selected from any one of -O-, -C(Ra12)(Ra13)-, -S-, -Si(Ra12)(Ra13)-, or -N(Ra12)-.

[0076] Furthermore, R1 to R3 that are not single-bonded to structural formula T1, R4 to R9 that are not single-bonded to structural formula T2, R10 to R25 and Ra1 to Ra13 are each independently hydrogen, deuterium, -F, cyano, nitro, or a group represented by any one of formulas I-1 to I-19, or a group represented by any one of formulas K-1 to K-182.

[0077] [Chemistry 6]

[0078]

[0079]

[0080] In formulae I-1 to I-19 and K-1 to K-182, "*" indicates a position bonding to an adjacent atom, "Ph" indicates a phenyl group, and "TMS" indicates a trimethylsilyl group.

[0081] In one embodiment of the present invention, R1 to R3 that are not single-bonded to structural formula T1, R4 to R9, R10 to R25 and Ra1 to Ra13 that are not single-bonded to structural formula T2 are each independently hydrogen, deuterium, -F, cyano, nitro, or a group represented by any one of formulas I-1 to I-19. In another embodiment of the present invention, R1 to R3 that are not single-bonded to structural formula T1, R4 to R9, R10 to R25 and Ra1 to Ra13 that are not single-bonded to structural formula T2 are each independently a group represented by any one of formulas K-1 to K-182.

[0082] In one embodiment of the present invention, compound (1) is further represented by any one of the following formulas (41) to (44).

[0083] [Chemistry 7]

[0084]

[0085] The definitions of X3 to X5 are the same as those of X1 to X2 in the above formula (1). That is, X3 to X5 are each independently selected from -O-, -C(Ra12)(Ra13)-, -S-, -Si(Ra12)(Ra13)-, or -N(Ra12)-.

[0086] Specific examples of the compound (1) of the present invention are shown below, but the invention is not limited thereto.

[0087] [Chemistry 8]

[0088]

[0089]

[0090]

[0091]

[0092] The method for producing the compound (1) of the present invention is not particularly limited, and a person skilled in the art can easily produce the compound (1) according to the method described in the present invention or by referring to a publicly disclosed synthesis method.

[0093] Materials for OLED

[0094] The material for an organic electroluminescent device of the present invention comprises an organometallic compound (1). The content of the compound (1) in the material for an organic electroluminescent device of the present invention is 0.5% by mass (inclusive) to 50% by mass (inclusive), preferably 5% by mass to 50% by mass (inclusive), and more preferably 10% by mass to 50% by mass (inclusive).

[0095] Description of OLED device structure

[0096] The OLED device in this specification is provided with a cathode, an anode and an organic layer arranged between the first electrode and the second electrode, wherein the organic layer comprises a light-emitting layer, and the light-emitting layer comprises the organic metal compound (1) as a material of a phosphorescent dopant or a phosphorescent sensitizer.

[0097] The organic electroluminescent device of the present invention can be a single-color device of fluorescent or phosphorescent light-emitting type, or a white light-emitting device of fluorescent / phosphorescent hybrid type, or a simple device with a single light-emitting unit, or a multilayer device of tandem type with multiple light-emitting units, wherein the organic metal compound (1) is used as a phosphorescent light-emitting dopant of phosphorescent light-emitting type, or a phosphorescent sensitizer of fluorescent light-emitting type. It should be particularly pointed out that "light-emitting unit" in the present invention refers to an organic layer, which includes at least one light-emitting layer of the minimum unit that emits light through the recombination of injected electrons and holes.

[0098] For example, as a representative device structure of a simple organic electroluminescent device, the following device structures can be cited.

[0099] (1) Anode / light-emitting unit / cathode

[0100] The light-emitting unit is not limited to a stacked type having multiple phosphorescent light-emitting layers or fluorescent light-emitting layers. Here, a spacer layer may be provided between the phosphorescent light-emitting layer and the fluorescent light-emitting layer to prevent triplet excitons in the phosphorescent light-emitting layer from diffusing to the fluorescent light-emitting layer and causing device performance to decrease. Furthermore, in order to improve the performance of the organic electroluminescent device, a hole transport region is provided between the anode and the light-emitting layer, and an electron transport region is provided between the cathode and the light-emitting layer to improve the recombination ratio of the electrons and hole carriers injected into the light-emitting layer. The hole transport region may include a hole injection layer, one or more hole transport layers, or a hole injection layer and one or more hole transport layers The multiple layers of the hole transport unit, the electron transport region may include an electron injection layer, one or more electron transport layers, or an electron injection layer and one or more electron transport layers Multiple layers constitute an electron transport unit. It should be particularly pointed out that the "hole transport layer" here sometimes also serves as an electron blocking layer or an exciton blocking layer, and the "electron transport layer" sometimes also serves as a hole blocking layer or an exciton blocking layer.

[0101] A typical layer structure of a simplified light-emitting unit is shown below, and the layers in parentheses may be optional.

[0102] (a-1) (hole injection layer / ) hole transport layer / fluorescent light emitting layer (compound (1) as phosphorescent sensitizer) / electron transport layer ( / electron injection layer)

[0103] (b-2) (hole injection layer / ) hole transport layer / phosphorescent layer (compound (1) as phosphorescent dopant) / electron transport layer ( / electron injection layer)

[0104] (c-3) (hole injection layer / ) hole transport layer / phosphorescent light emitting layer / spacer layer / fluorescent light emitting layer / electron transport layer ( / electron injection layer)

[0105] (d-4) (hole injection layer / ) hole transport layer / first phosphorescent emitting layer / second phosphorescent emitting layer / spacer layer / fluorescent emitting layer (compound (1) as phosphorescent sensitizer) / electron transport layer ( / electron injection layer)

[0106] (e-5) (hole injection layer / ) hole transport layer / phosphorescent emitting layer (compound (1) as phosphorescent emitting dopant) / spacer layer / first fluorescent emitting layer / second fluorescent emitting layer / electron transport layer ( / electron injection layer)

[0107] (f-6) (hole injection layer / ) first hole transport layer / second hole transport layer / fluorescent light emitting layer (compound (1) as phosphorescent sensitizer) / electron transport layer ( / electron injection layer)

[0108] (g-7) (hole injection layer / ) first hole transport layer / second hole transport layer / phosphorescent light emitting layer (compound (1) as phosphorescent light emitting dopant) / electron transport layer ( / electron injection layer)

[0109] It should be noted that each light emitting unit of the device having multiple light emitting units can independently emit different light colors, or emit the same color. Compound (1) can be used as a phosphorescent dopant of the phosphorescent light emitting unit in the above device structure or a phosphorescent sensitizer in the fluorescent light emitting unit.

[0110] As a typical structure of a tandem organic electroluminescent device, the following device configurations can be cited.

[0111] (2) Anode / first light-emitting layer / charge generation layer / second light-emitting layer / anode

[0112] Here, the first light-emitting layer and the second light-emitting layer may emit light of different colors or the same color, and may be independently selected from the light-emitting layers in the simplified device configuration. Moreover, at least one of the first light-emitting layer and the second light-emitting layer contains the compound (1) as a phosphorescent dopant in a phosphorescent light-emitting unit or a phosphorescent sensitizer in a fluorescent light-emitting unit. A typical configuration of the charge generation layer is a pair of intermediate electrodes comprising a hole-type charge generation layer (or P-type charge generation layer and dopant) and an electron-type charge generation layer (or N-type charge generation layer and dopant).

[0113] It should be particularly pointed out that, whether in a simple or tandem organic electroluminescent device, or in a fluorescent or phosphorescent organic electroluminescent device structure, compound (1) is used as a phosphorescent dopant in a simple or tandem phosphorescent organic electroluminescent device, or as a phosphorescent sensitizer in a simple or tandem fluorescent organic electroluminescent device.

[0114] As an example of a light-emitting layer containing compound (1) as a phosphorescent dopant, the light-emitting layer contains a phosphorescent host material and the compound (1) as a phosphorescent dopant. The phosphorescent host can be a host material with hole transport properties, a host material with electron transport properties, a host material with both hole transport properties and electron transport properties, or an exciplex host material formed by mixing two materials containing a material with hole transport properties and another material with electron transport properties, or a host material with the ability to transfer 100% of the excitons generated by the host material to the compound (1) and all of them are used for phosphorescent emission. Here, the "mixed formation" refers to an exciplex material formed by physical mixing, such as vacuum thermal evaporation, or chemical methods. The host material "with 100% of the excitons transferred to the compound (1) and all of them are used for phosphorescent emission" can be a thermally delayed activated fluorescent material, a multi-resonance type boron nitrogen material, or a multi-resonance type carbazole indole derivative material, but is not limited thereto.

[0115] As an example of a light-emitting layer containing compound (1) as a phosphorescent sensitizer, the light-emitting layer includes a host material, a phosphorescent sensitizer, and a fluorescent dopant. The host material refers to an organic material in which holes and electron carriers injected into the host material can generate singlet and triplet excitons, and can be a host material with hole transport properties, a host material with electron transport properties, a host material with both hole transport properties and electron transport properties, or an exciplex host material formed by mixing two materials containing a hole transport property and another material with electron transport properties, or a host material that can transfer 100% of the excitons generated by the host material to the compound (1) and use them all for phosphorescence. Here, the "mixed formation" refers to an exciplex material formed by physical mixing, such as vacuum thermal evaporation, or chemical mixing. The host material of "100% of the excitons are transferred to the compound (1) and all used for phosphorescence" can be a thermally delayed activated fluorescent material, a multi-resonance type boron nitrogen material, or a multi-resonance type carbazole indole derivative material, but is not limited thereto. The fluorescent dopant is a material that uses singlet excitons for fluorescent emission, and can be a multi-resonance type boron nitrogen material, or a multi-resonance type carbazole indole derivative material. In the above-mentioned light-emitting layer, the excitons on the host material can be transferred to the phosphorescent sensitizer through the Forster type energy transfer method or the Dexter type energy transfer method, or through both the Forster and Dexter methods, and then the excitons on the phosphorescent sensitizer are transferred to the fluorescent dopant for fluorescent emission, forming an organic electroluminescent device.

[0116] Figure 1 The schematic diagram of an OLED device structure 100 containing compound (1) as a phosphorescent dopant. In the structure of the device structure 100, a substrate 11 is included, an anode 12 is arranged on the substrate 11, a light-emitting unit 15 is arranged on the anode 12, and a cathode 18 is prepared on the light-emitting unit 15. Among them, a hole transport unit 13 composed of a first hole transport layer 13a and a second hole transport layer 13b is also included between the anode 12 and the light-emitting unit 15. The light-emitting unit 15 and the hole transport unit 13 also include an electron blocking layer 14. The cathode 18 and the light-emitting layer 15 also include an electron transport unit 16 composed of a first electron transport unit 16a and a second electron transport unit 16b. An electron injection layer 17 is formed on the electron transport unit 16. The organic metal compound (1) is a phosphorescent dopant of the layer of the light-emitting unit 15.

[0117] Figure 2 Schematic diagram of an OLED device structure 200 containing compound (1) as a phosphorescent sensitizer. In the structure of the device 200, a substrate 21, an anode 22 prepared on the substrate 21, a light-emitting unit 25 formed on the anode 22, and a cathode 28 formed on the light-emitting unit 25 are provided. Among them, a hole transport unit 23 composed of a first hole transport layer 23a and a second hole transport layer 23b is also included between the light-emitting unit 25 and the anode 22. An electron blocking layer 24 is also formed between the hole transport unit 23 and the light-emitting unit 25. An electron transport unit 26 composed of a first electron transport unit 26a and a second electron transport unit 26b and an electron injection layer 27 formed on the electron transport unit 26 are sequentially formed between the light-emitting layer 25 and the cathode 28. The organic metal compound (1) can be used as a phosphorescent sensitizer of the layer of the light-emitting unit 25.

[0118] Figure 3 The schematic diagram of energy transfer of an OLED device structure containing compound (1) as a phosphorescent sensitizer. The black wireframe represents a light-emitting layer containing an exciplex host material CBH (usually an exciplex host material CBH formed by evaporating a hole transport host HT and an electron transport host ET in a certain ratio), a phosphorescent sensitizer SZ, and a fluorescent dopant BD. The solid arrow represents the energy transfer path, and the dotted arrow represents the internal energy conversion path. Figure 3As described above, hole carriers and electron carriers recombine on the CBH material in the light-emitting layer, and singlet excitons and triplet excitons are formed after the recombination, wherein the triplet and singlet excitons of the main material of the exciplex can compete with each other through reverse gap crossing and gap crossing, and the singlet excitons on the main material of the exciplex can be transferred to the fluorescent material BD through path ① for fluorescent emission, and the triplet excitons generated on the main material of the exciplex are transferred to the triplet of the phosphorescent sensitizer SZ through path ②; the phosphorescent sensitizer SZ is transferred to the singlet of the fluorescent dopant BD through path ③; the singlet excitons of the fluorescent dopant directly emit fluorescence through path ④.

[0119] Example

[0120] Hereinafter, the present invention will be described in further detail using examples, but the present invention is not limited to the following examples.

[0121] Synthesis Example 1 Synthesis of Compound 1

[0122]

[0123] Compound 1 was synthesized using the same operation as CN112341497A. That is, intermediate 1-a (10 mmol), intermediate 1-b (10 mmol), 2.2 mmol copper (I) iodide, 5 mmol picolinic acid, 38 mmol tripotassium phosphate and 100 ml of dimethyl sulfoxide were added to a flask under nitrogen protection, and the mixture was heated to 100 ° C for 15 hours after being fully mixed. After the reaction was completed, the mixture was cooled to room temperature, and the organic phase was extracted with saturated ammonium chloride and ethyl acetate. The organic phase after extraction was dried over anhydrous magnesium sulfate, then filtered and concentrated under reduced pressure. The product was purified by silica gel column chromatography to obtain intermediate 1-c.

[0124] The obtained intermediate 1-c and 20 mmol of intermediate 1-d were added to a reaction bottle containing copper acetate Cu(OAc)2 and N,N-dimethylformamide DMF, and then heated to 100°C for 1 hour. After the reaction was completed, the mixture was cooled to room temperature and purified by silica gel column chromatography to obtain intermediate 1-f.

[0125] The obtained intermediate 1-f, 7.5mmol of Pt(COD)Cl2, 20mmol of sodium acetate and 250ml of tetrahydrofuran were mixed, and then stirred at 120°C for 36 hours. After the reaction was completed, it was cooled to room temperature, and the organic phase was extracted with saturated ammonium chloride and dichloromethane. The obtained organic phase was dried, filtered and concentrated under reduced pressure using anhydrous magnesium sulfate. The obtained product was purified by silica gel column chromatography to obtain a solid of compound 1.

[0126] The result of mass spectrometry analysis of the obtained solid was: relative molecular weight 1066.31, m / e=1066, and it was compound 1.

[0127] Synthesis Example 2 Synthesis of Compound 2

[0128]

[0129] The synthesis method of compound 2 uses the same operation as compound 1, except that intermediate 1-b is replaced by intermediate 2-b.

[0130] The result of mass spectrometry analysis of the obtained compound was: relative molecular weight 1092.36, m / e=1092, and it was compound 2.

[0131] Synthesis Example 3 Synthesis of Compound 3

[0132]

[0133] The synthesis method of compound 3 uses the same operation as compound 1, as long as intermediate 1-b is replaced by intermediate 3-b.

[0134] The result of mass spectrometry analysis of the obtained compound was: relative molecular weight 1066.31, m / e=1066, and it was compound 3.

[0135] Synthesis Example 4 Synthesis of Compound 4

[0136]

[0137] The synthesis method of compound 4 uses the same procedure as compound 1, except that intermediates 1-b and 1-d are replaced by intermediates 4-b and 4-d.

[0138] The result of mass spectrometry analysis of the obtained compound was: relative molecular weight 1084.43, m / e=1084, and it was compound 4.

[0139] Synthesis Example 5 Synthesis of Compound 5

[0140]

[0141] The synthesis method of compound 5 uses the same operation as compound 1, as long as intermediate 1-b is replaced by intermediate 5-b.

[0142] The obtained product was subjected to mass spectrometry analysis: relative molecular weight 1066.31, m / e=1066, and was compound 5.

[0143] Synthesis Example 6 Synthesis of Compound 6

[0144]

[0145] The synthesis method of compound 6 uses the same operation as compound 1, except that intermediate 1-b is replaced by intermediate 6-b.

[0146] The obtained product was subjected to mass spectrometry analysis: relative molecular weight 1092.36, m / e=1092, and was compound 6.

[0147] Synthesis Example 7 Synthesis of Compound 7

[0148]

[0149] The synthesis method of compound 7 uses the same procedure as compound 1, except that intermediate 1-a is replaced by intermediate 7-a.

[0150] The obtained product was subjected to mass spectrometry analysis: relative molecular weight 1066.31, m / e=1066, and was compound 7.

[0151] Synthesis Example 8 Synthesis of Compound 8

[0152]

[0153] The synthesis method of compound 8 uses the same procedure as compound 4, except that intermediates 1-a and 4-d are replaced with intermediates 8-a and 8-d.

[0154] The obtained product was subjected to mass spectrometry analysis: relative molecular weight 967.22, m / e=967, and was compound 8.

[0155] Synthesis Example 9 Synthesis of Compound 9

[0156]

[0157] The synthesis method of compound 9 uses the same procedure as compound 8, except that intermediates 8-a and 2-b are replaced by intermediates 9-a and 3-b.

[0158] The obtained product was subjected to mass spectrometry analysis: relative molecular weight 967.22, m / e=967, and was compound 9.

[0159] Synthesis Example 10 Synthesis of Compound 10

[0160]

[0161] The synthesis method of compound 10 uses the same procedure as compound 8, except that intermediates 8-a and 2-b are replaced by intermediates 1-a and 10-b.

[0162] The obtained product was subjected to mass spectrometry analysis: relative molecular weight 982.18, m / e=982, and was compound 10.

[0163] Synthesis Example 11 Synthesis of Compound 11

[0164]

[0165] The synthesis method of compound 11 uses the same procedure as compound 8, as long as intermediates 8-a and 2-b are replaced by intermediates 1-a and 11-b.

[0166] The obtained product was subjected to mass spectrometry analysis: relative molecular weight 1008.23, m / e=1008, and was compound 11.

[0167] Synthesis Example 12 Synthesis of Compound 12

[0168]

[0169] The synthesis method of compound 12 uses the same procedure as compound 8, as long as intermediates 8-a and 2-b are replaced by intermediates 12-a and 5-b.

[0170] The obtained product was subjected to mass spectrometry analysis: relative molecular weight 982.18, m / e=982, and was compound 12.

[0171] Synthesis Example 13 Synthesis of Compound 13

[0172]

[0173] The synthesis method of compound 13 uses the same procedure as compound 8, as long as intermediates 8-a and 2-b are replaced by intermediates 13-a and 13-b.

[0174] The obtained product was subjected to mass spectrometry analysis: relative molecular weight 982.18, m / e=982, and was compound 13.

[0175] Synthesis Example 14 Synthesis of Compound 14

[0176]

[0177] The synthesis method of compound 14 uses the same procedure as compound 8, as long as intermediates 8-a and 2-b are replaced by intermediates 1-a and 14-b.

[0178] The result of mass spectrometry analysis of the obtained product was: relative molecular weight 1040.24, m / e=1040, and it was compound 14.

[0179] Synthesis Example 15 Synthesis of Compound 15

[0180]

[0181] The synthesis method of compound 15 uses the same procedure as compound 8, as long as intermediates 8-a and 2-b are replaced by intermediates 15-a and 4-b.

[0182] The result of mass spectrometry analysis of the obtained product was: relative molecular weight 1040.24, m / e=1040, and it was compound 15.

[0183] Example 1 Fabrication of a device as a phosphorescent dopant

[0184] Top emission device structure: ITO / HT1:HATCN (3wt%, 10nm) / HT1 (50nm) / HT2 (5nm) / HT2 (60wt%):ET1 (27wt%):Compound 1 (13wt%, 35nm) / ET2 (5nm) / ET2:LiQ (50wt, 30nm) / Yb (1nm) / Mg:Ag (1:9, 130nm) / HT1 (70nm).

[0185] Material structure used in the device

[0186]

[0187] Characterization of device performance

[0188] The driving voltage, efficiency and spectrum were tested under 1000 nits condition, and the results are recorded in Table 1.

[0189] At 1000 nits, the brightness decays to 90% of the initial brightness, which is defined as LT90. The results are shown in Table 1 below.

[0190] Embodiments 2 to 11

[0191] Compound 1 was replaced by compounds 2 to 11 which acted on the light-emitting layer 15 as phosphorescent dopants. Devices 2 to 11 were manufactured in the same manner as in Example 1. The device performance was tested. The results are shown in Table 1.

[0192] Comparative Examples 1 to 5

[0193] Compound 1 is replaced by "Comparative Compound 1" (compound recorded in reference patent document 1), or replaced by "Comparative Compound 2" (compound recorded in reference patent document 2), or replaced by "Comparative Compound 3" (compound recorded in reference patent document 3), or replaced by "Comparative Compound 4" (compound recorded in reference patent document 4), or replaced by "Comparative Compound 5" (compound recorded in reference patent document 5) and used as the phosphorescent dopant material in the light-emitting layer 15. The same device preparation process and measurement conditions are used, and the results are shown in Table 1.

[0194] Example 12: Fabrication of a device as a phosphorescence sensitizer

[0195] The device structure containing phosphorescent sensitizer is ITO / HT1:HATCN (3wt%, 10nm) / HT1 (50nm) / HT3 (5nm) / BH1 (78wt%):Compound 12 (20wt%):BD1 (2wt%, 30nm) / ET3 (5nm) / ET3:LiQ (50wt, 30nm) / Yb (1nm) / Mg:Ag (1:9, 130nm) / HT1 (70nm)

[0196] Material structure used in the device

[0197]

[0198] Characterization of device performance

[0199] At 10mA / cm 2 The driving voltage, efficiency and spectrum were tested under the following conditions, and the results are recorded in Table 1.

[0200] At 20mA / cm 2 The brightness decay to 90% of the initial brightness is defined as LT90. The results are shown in Table 1 below.

[0201] Embodiments 13 to 15

[0202] Compound 12 was replaced by compounds 13 to 15 to act on the phosphorescence sensitizer in the light-emitting layer 25 respectively. Devices 13 to 15 were manufactured in the same manner as in Example 12, and the device performance was tested. The results are shown in Table 1.

[0203] Comparative Examples 6-7

[0204] Compound 12 was replaced with "Comparative Compound 6" (compound recorded in reference patent document 6) or "Comparative Compound 7" (compound recorded in reference patent document 7) and used as the phosphorescent sensitizer in the light-emitting layer 25. The same device preparation process and measurement conditions were used, and the results are shown in Table 1.

[0205] Materials used in Comparative Examples 1 to 7

[0206]

[0207] It should be particularly pointed out that compounds 1 to 15 of the present invention simultaneously meet two important conditions, namely, molecular structural element Y-1: the carbene carbon atom of benzimidazole and the carbazole group are bonded to the central nitrogen atom, and molecular structural element Y-2: structural formulas T1 and T2 are respectively bonded to two adjacent carbon atoms of the benzene ring and the carbazole ring connected by the bridging oxygen bond.

[0208] "Comparative compounds 1 to 4 and 6 to 7" do not satisfy the molecular structural elements Y-1 and Y-2, whereas "Comparative compound 5" only satisfies the molecular structural element Y-1 but does not satisfy the molecular structural element Y-2.

[0209] [Table 1]

[0210]

[0211] Note: “ / ” indicates that both the embodiment and the comparative example use the same fluorescent luminescent material as the luminescent material, have the same luminescent spectrum and half-peak width, and therefore no comparison of device effects is made;

[0212] [*a]:PLQY, test method: 10nm of the test substance was evaporated on quartz glass and tested under a nitrogen atmosphere using a Horiba FluoroMax-4 transient fluorescence spectrometer;

[0213] [*b]: Exciton lifetime, test method: 10 nm of the test substance was evaporated on quartz glass and tested under a nitrogen atmosphere using a Horiba FluoroMax-4 transient fluorescence spectrometer;

[0214] [*c]: LT50, light-induced aging life, test method: the time it takes for the initial brightness of the object to decay to 50% under ultraviolet 365nm band;

[0215] [*d]: BDE, triplet dissociation energy of CH, measured by DFT density functional theory using Gaussian 09 software, basis set PBE0;

[0216] Referring to Table 1, Examples 1 to 11 as phosphorescent dopants show the functions of low voltage drive, long life and high efficiency. Without being bound by theory, it is believed that according to the embodiments, by introducing the molecular structural elements Y-1 and Y-2 elements, it is beneficial to enhance the carrier mobility of the phosphorescent dopant molecules, improve the transition dipole moment of the luminescent molecules and improve the luminous efficiency, promote the radiation decay of triplet excitons and enhance the device life, and suppress the high-frequency electronic vibration mode to reduce the half-peak width intensity.

[0217] Comparative compounds 1 to 5 do not satisfy the molecular structural elements Y-1 and Y-2, or only satisfy one of the structural elements, and exhibit higher driving voltage, lower luminous efficiency, poorer color purity and shorter device life.

[0218] Referring to Table 1, Examples 12 to 15 as phosphorescent sensitizers show the functions of low voltage drive, long life and high efficiency. Without being bound by theory, it is believed that the molecular structural elements Y-1 and Y-2 are beneficial to enhance the rapid transfer of the triplet state of the exciplex host CBH to the singlet energy level of the fluorescent dopant through paths ② and ③, ensuring 100% exciton energy transfer and improving the transfer speed, thereby obtaining better luminous efficiency and life.

[0219] Comparative compounds 6 and 7 showed poor device efficiency or short lifespan due to not satisfying the molecular structure elements.

[0220] Evaluation Example 1: [PLQY]

[0221] After evaporating 10 nm of the test substance, the absolute quantum yield of the substance was measured by a Hariba FluoroMax-4 test system under a nitrogen atmosphere and recorded in Table 1.

[0222] Referring to Table 1, after introducing the molecular structural element Y-2, compounds 1 to 15 show higher quantum yields (108% to 121%), which helps to increase the number of photons released from the excited state of the phosphorescent dopant, thereby improving the luminous efficiency of the luminescent molecule. Comparative compounds 1 to 7 do not meet the molecular structural element Y-2 and show a lower level of quantum yield (82% to 103%).

[0223] Evaluation Example 2: [Exciton Lifetime]

[0224] After evaporating 10 nm of the test material, the phosphorescence exciton lifetime of the material was measured by the Hariba FluoroMax-4 test system in a nitrogen atmosphere and recorded in Table 1. The phosphorescence decay rate Kp can be described by the following formula (1):

[0225]

[0226] According to formula (1), the phosphorescence decay amount of metal organic compounds depends on That is, the transition dipole moment of the triplet state. Referring to Table 1, the synergistic effect of the molecular structural elements Y-1 and Y-2, compounds 1 to 15 increase the transition dipole moment. The carbene structure of the molecular structural element Y-1 is bonded to the nitrogen atom of the carbazole ring, and the strong field ligand effect of the carbene structure is conducive to improving At the same time, the ring structure of the adjacent carbon atoms of the benzene ring and the carbazole ring bonded to the structural formula T1 and T2 further improves the transition dipole moment of the molecule and promotes spin-orbit coupling, thereby exhibiting a shorter phosphorescent triplet exciton lifetime (30% to 67%).

[0227] Since comparative compounds 1 to 7 do not satisfy the two structural elements simultaneously, they show a smaller phosphorescence decay rate and obtain a longer triplet exciton lifetime (84% to 142%).

[0228] Evaluation Example 3: [Light-induced aging life LT50]

[0229] When the phosphorescent molecule absorbs short-wavelength energy, it emits a blue wavelength of corresponding intensity. When the energy of the excitation wavelength is higher than the chemical bond of the phosphorescent molecule itself, the molecule tends to undergo a series of complex chemical degradation processes, resulting in the attenuation of the blue light luminescence brightness. The attenuation life data is recorded in Table 1.

[0230] After the introduction of the molecular structural elements Y-1 and Y-2, compounds 1 to 15 showed very long light-induced aging lifetimes LT50. This is because the molecular structural element Y-2 is conducive to forming a relatively extended triplet exciton transfer plane (or increasing the exciton transfer rate), thereby improving the ability to resist the damage caused by light-induced aging and extending the luminescence lifetime LT50 (158% to 295%).

[0231] Comparative compounds 1 to 7 show shorter anti-light-induced aging lifetimes LT50 (63% to 147%). This is because after the molecules absorb the energy of the excitation wavelength, the excited molecules do not have time to transfer the high energy, resulting in the breaking of chemical bonds.

[0232] Evaluation Example 4: [BDE of triplet molecule]

[0233] For phosphorescent molecules, the breaking of the CH chemical bond is a major channel for reducing the device life. The specific process can be described by the following formula (2). That is, after a phosphorescent molecule absorbs energy, the weakest CH bond and the positively charged main material A + The triplet transition state is formed. This high-energy transition state is unstable and then chemically degrades to form a more active free radical carbon center. The organometallic compound containing the free radical carbon center further undergoes a complex chemical degradation process. Therefore, the triplet CH chemical bond is crucial to improving the life of the phosphorescent dopant or phosphorescent sensitizer device.

[0234]

[0235] The CH dissociation energies of the metal organic compounds were evaluated using the DT-DFT method using Gaussian 09 software and are listed in Table 1.

[0236] Referring to Table 1, compounds 1 to 15 that simultaneously introduce the molecular elements Y-1 and Y-2 are beneficial to suppressing the CH vibration in the triplet state and increasing the chemical bond dissociation energy BDE (30.5 to 32.6 Kcal / mol). Comparative compounds 1 to 7 have lower chemical bond dissociation energy BDE (27.8 to 30.1 Kcal / mol) due to not satisfying the molecular structure elements, and thus have lower device life or light-induced aging life.

[0237] Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the claims. Any technical personnel in this field may make several possible changes and modifications without departing from the concept of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined by the claims of the present application.

Claims

1. An organometallic compound represented by the following formula (1), In formula (1), M is platinum, palladium, iridium, gold, silver, nickel, manganese, zinc or copper; Two adjacent R1 to R3 are single bonds bonded to the structural formula T1; R1 to R3 which are not single bonds to the structural formula T1 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or an unsubstituted heterocyclic group having 1 to 60 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, -C(Ra1)(Ra2)(Ra3), -Si(Ra1)(Ra2)(Ra3), -N(Ra1)(Ra2), -B(Ra1)(Ra2), -C(=O)(Ra1), -S(=O)(Ra1), or -P(=O)(Ra1)(Ra2); At least one set of two adjacent ones of R4 to R9 is a single bond bonded to the structural formula T2; R4 to R9 which are not single bonds to the structural formula T2 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or an unsubstituted heterocyclic group having 1 to 60 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, -C(Ra4)(Ra5)(Ra6), -Si(Ra4)(Ra5)(Ra6), -N(Ra4)(Ra5), -B(Ra4)(Ra5), -C(=O)(Ra4), -S(=O)(Ra4), or -P(=O)(Ra4)(Ra5), in, Two adjacent R4 to R9 selected from the group not forming a single bond with the structural formula T2 are independently hydrogen atoms, deuterium atoms or the substituents, or are bonded to each other to form a ring structure, wherein the ring structure is a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 18 ring carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon ring having 5 to 18 ring carbon atoms, a substituted or unsubstituted aromatic heterocycle having 5 to 18 ring atoms, or a substituted or unsubstituted aliphatic heterocycle having 5 to 18 ring atoms; Ring cy1 is selected from an aryl group having 6 to 60 carbon atoms or a heterocyclic group having 1 to 60 carbon atoms; Ring cy2 is selected from an aryl group having 6 to 60 carbon atoms or a heterocyclic group having 1 to 60 carbon atoms, and there is a coordination bond between ring cy2 and M; a1 and a2 are each independently an integer from 0 to 10; R10 to R20 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from the group consisting of a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted heterocyclic group having 1 to 60 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, -C(Ra7)(Ra8)(Ra9), -Si(Ra7)(Ra8)(Ra9), -N(Ra7)(Ra8), -B(Ra7)(Ra8), -C(=O)(Ra7), -S(=O)(Ra7), or -P(=O)(Ra7)(Ra8), Wherein, two adjacent ones selected from R10 to R20 are independently represented by hydrogen atoms, deuterium atoms or the substituents, or are bonded to each other to form a ring structure, and the ring structure is a substituted or unsubstituted aromatic hydrocarbon ring with 6 to 18 ring carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon ring with 5 to 18 ring carbon atoms, a substituted or unsubstituted aromatic heterocycle with 5 to 18 ring atoms, or a substituted or unsubstituted aliphatic heterocycle with 5 to 18 ring atoms; L1 is selected from -O-, -S-, -Se-, -N(Ra10)-, -B(Ra10)-, -P(Ra10)-, -P(=O)(Ra10)-, -S(=O)2-, -S(=O)(Ra10)(Ra11)-, -C(=O)-, -C(Ra10)(Ra11)-, -Si(Ra10)(Ra11)-, or Ge(Ra10)(Ra11)-; X1 and X2 are each independently -O-, -C(Ra12)(Ra13)-, -S-, -Si(Ra12)(Ra13)-, or -N(Ra12)-; Ra1 to Ra13 are each independently selected from a hydrogen atom, a deuterium atom or a substituent selected from the group consisting of a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted heterocyclic group having 1 to 60 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 60 carbon atoms, or a substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, Wherein, two adjacent ones selected from Ra1 to Ra13 independently represent a hydrogen atom, a deuterium atom or the above-mentioned substituents, or are bonded to each other to form a ring structure, wherein the ring structure is a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 18 ring carbon atoms, a substituted or unsubstituted aliphatic hydrocarbon ring having 5 to 18 ring carbon atoms, a substituted or unsubstituted aromatic heterocycle having 5 to 18 ring atoms, or a substituted or unsubstituted aliphatic heterocycle having 5 to 18 ring atoms; "*" indicates the positions where two adjacent ones of R1 to R9 form single bonds with the structural formulae T1 and T2.

2. The organometallic compound according to claim 1, wherein M is platinum, palladium or gold.

3. The organometallic compound according to claim 1, wherein two adjacent ones of R1 to R3 are single bonds bonded to the structural formula T1, and at least one set of two adjacent ones of R4 to R9 are single bonds bonded to the structural formula T2, which is represented by the following formulas (2) to (40): In formulas (2) to (40), R21 to R24 have the same meanings as the corresponding substituents of R10 to R20 in formula (1); X3 has the same definition as that of X1 and X2 in formula (1).

4. The organometallic compound according to claim 1, wherein the ring cy1 is represented by the following formulas cy1-1 to cy1-9: Ring cy2 is represented by the following formulas cy2-1 to cy2-30, In the formulas cy1-1 to cy1-9 and cy2-1 to cy2-30, X4 to X5 are the same as the corresponding substituents X1 to X3 described in formula (1); The definition of R25 is the same as that of the corresponding substituents R1 to R12 in claim 1.

5. The metal organic compound as claimed in claim 1, wherein R1 to R3 which are not single bonds to the structural formula T1, R4 to R9, R10 to R25 and Ra1 to Ra13 which are not single bonds to the structural formula T2 are each independently hydrogen, deuterium, -F, cyano, nitro, or a group represented by any one of the formulas I-1 to I-19, or a group represented by any one of the formulas K-1 to K-182: in, In formulae I-1 to I-19 and K-1 to K-182, "*" indicates a position of a single bond, "Ph" indicates a phenyl group, and "TMS" indicates a trimethylsilyl group.

6. The metal organic compound as claimed in claim 1, wherein The organometallic compound represented by formula (1) is preferably represented by any one of formula (41) to formula (44), In formula (41) to formula (42), The definitions of R1 to R20, R25, X1, X2, X4, X5, a1, a2 and L1 should be understood with reference to the corresponding descriptions in Claims 1 to 5.

7. The metal organic compound according to claim 1 to 6, which is represented by any one of the following chemical formulas:

8. An organic electroluminescent device, characterized in that: include: a first electrode; A second electrode, opposite to the first electrode; And, an organic layer disposed between the first electrode and the second electrode, wherein the organic layer comprises a light-emitting layer, and the light-emitting layer comprises the compound according to any one of claims 1 to 7.

9. The organic electroluminescent device according to claim 8, wherein the organic metal compound is used as a phosphorescent dopant or a phosphorescent sensitizer.

10. The organic electroluminescent device according to claims 8 to 9, characterized in that: A hole transport unit is included between the first electrode and the light-emitting layer, and an electron transport unit is included between the light-emitting layer and the second electrode.

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