Compounds as phosphorescent emitters in organic electroluminescent devices and use thereof

Abstract

The present application relates to emitter compound technical field, specifically to a kind of compound as phosphorescent emitter in organic electroluminescence device and application thereof.The compound described in the present application comprises: at least one aromatic ring or heteroaromatic ring, the aromatic ring or heteroaromatic ring has at least one substituent group shown in formula (I).The compound introduces five-membered ring ligand containing boron atom, as phosphorescent emitter in organic electroluminescence device can make emission spectrum narrow, reduce sublimation temperature, improve the luminous efficiency of device.At the same time, these five-membered ring ligands containing boron atom are introduced into iridium or platinum complex, can well improve the sublimation stability of the obtained iridium complex, platinum complex, improve the phosphorescent quantum yield of these complexes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of emitter compounds, in particular to a compound as a phosphorescent emitter in an organic electroluminescent device and application thereof. BACKGROUND

[0002] Organic electroluminescence (OLED) and related researches were first discovered by Pope et al. in 1963 that single crystal anthracene of organic compounds had electroluminescence phenomenon. In 1987, Kodak Company of the United States prepared a non-crystalline film type device by evaporating organic small molecules, and the driving voltage was reduced to below 20V. This kind of device has the advantages of ultra-thin, full solidification, self-luminescence, high brightness, wide viewing angle, fast response speed, low driving voltage, low power consumption, bright color, high contrast, simple process, good temperature characteristics, and can realize flexible display, which can be widely used in flat panel displays and surface light sources, and has been widely studied, developed and used.

[0003] Organic electroluminescence is mainly divided into fluorescence and phosphorescence, but according to the spin quantum statistics theory, the probability of singlet exciton and triplet exciton is 1:3, that is, the theoretical limit of fluorescence from singlet exciton radiation transition is 25%, and the theoretical limit of fluorescence from triplet exciton radiation transition is 75%. How to utilize the energy of 75% of triplet exciton has become an urgent task. In 1997, Forrest et al. discovered the phenomenon of phosphorescent electroluminescence, which broke through the 25% efficiency limit of quantum efficiency of organic electroluminescent materials, and attracted widespread attention to metal complex phosphorescent materials.

[0004] It is believed that the ligand directly contributes to the photosensitive properties of the phosphorescent material, and the ligand can be called "photosensitive". When the ligand does not contribute to the photosensitive properties of the luminescent material, the ligand can be called "auxiliary", but the auxiliary ligand can modify the properties of the photosensitive ligand.

[0005] Therefore, it is necessary to provide a ligand capable of improving the quantum efficiency of the phosphorescent material while reducing the sublimation temperature, adjusting the arrangement mode of the phosphorescent material thin film, and improving the service life of the device. SUMMARY

[0006] The first object of the present application is to provide a compound as a phosphorescent emitter in an organic electroluminescent device.

[0007] The second object of the present application is to provide an organic light-emitting device comprising the compound.

[0008] In order to achieve the above-mentioned first object, the present application adopts the following technical scheme:

[0009] A compound used as a phosphorescent emitter in an organic electroluminescent device, characterized in that the compound comprises: at least one aromatic or heteroaromatic ring having at least one substituent represented by formula (I):

[0010]

[0011] In formula (I):

[0012] Ring A represents a 5-membered carbon ring, a 5-membered hetero ring, a 6-membered carbon ring, a 6-membered hetero ring, or no ring A;

[0013] R 1 , R 2 are identical or different, each independently selected from the group consisting of hydrogen, deuterium, nitrile, substituted or unsubstituted C1-C 40 linear alkyl, substituted or unsubstituted C1-C 40 linear heteroalkyl, substituted or unsubstituted C3-C 40 branched or cyclic alkyl, substituted or unsubstituted C3-C 40 branched or cyclic heteroalkyl, substituted or unsubstituted C1-C 60 arylalkyl, substituted or unsubstituted C3-C 40 silyl, substituted or unsubstituted C2-C 40 alkenyl, substituted or unsubstituted C4-C 40 cycloalkenyl, substituted or unsubstituted C2-C 40 heteroalkenyl, substituted or unsubstituted C2-C 40 alkynyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C2-C 60 heteroaryl;

[0014] R 3 represents one or more to saturation substitution, each independently selected from the group consisting of hydrogen, deuterium, halogen atom, nitrile, acyl, carboxyl, ether, ester, isonitrile, sulfide, selenoalkyl, sulfinyl, sulfonyl, phosphine, substituted or unsubstituted C1-C 40 linear alkyl, substituted or unsubstituted C1-C 40 linear heteroalkyl, substituted or unsubstituted C3-C 40 branched or cyclic alkyl, substituted or unsubstituted C3-C 40 branched or cyclic heteroalkyl, substituted or unsubstituted C1-C 40 linear alkoxy, substituted or unsubstituted C3-C 40 branched or cyclic alkoxy, substituted or unsubstituted C6-C 60 arylalkyl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C60 Aromatic amino group, substituted or unsubstituted C3-C 40 Silyl, substituted or unsubstituted C2-C 40 Alkenyl, substituted or unsubstituted C4-C 40 Cycloalkenyl, substituted or unsubstituted C2-C 40 Heterene, substituted or unsubstituted C2-C 40 Alkyne group, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C2-C 60 Groups composed of heteroaryl groups;

[0015] The dashed line represents the bond connecting formula (I) and the aromatic ring;

[0016] Indicates a single bond or a double bond.

[0017] In this invention, a 5-membered carbon ring refers to a cycloalkane or cycloalkene ring containing 5 carbon atoms, and a 5-membered heterocycle refers to a ring with a total of 5 carbon atoms and heteroatoms. The heteroatoms are preferably selected from N, O, B, or S. The 5-membered carbon ring and 5-membered heterocycle here can be aliphatic rings or heteroaromatic rings, such as cyclopentane, cyclopentene, cyclopentadiene, furan, tetrahydrofuran, thiophene, tetrahydrothiophene, pyrrole, pyrrolidine, imidazole, triazole, pyrazole, oxazole, oxadiazole, etc. A 6-membered carbon ring refers to a cycloalkanes, cycloalkenes, or aromatic rings containing 6 carbon atoms. A 6-membered heterocycle refers to an aliphatic ring or heteroaromatic ring in which the total number of carbon atoms and heteroatoms constituting the ring is 6. Here, 6-membered carbon rings and 6-membered heterocycles are non-limiting examples, such as cyclohexane, cyclohexene, cyclohexadiene, pyran, tetrahydropyran, piperidine, pyridine, benzene, thiaran, tetrahydrothiaran, dioxane, dithiaran, piperazine, pyrimidine, triazine, etc., or fused 6-membered carbon rings or 6-membered heterocycles, such as naphthalene, tetrahydronaphthalene, quinoline, isoquinoline, tetrahydroquinoline, tropane, quinazoline, quinoxaline, etc.

[0018] In this invention, aryl or aromatic rings contain 6-60 carbon atoms, and heteroaryl or heteroaromatic rings contain 2-60 carbon atoms and at least one heteroatom, provided that the total number of carbon atoms and heteroatom is at least 5; the heteroatom is preferably selected from N, O, B, or S. Here, aryl, aromatic ring, heteroaryl, or heteroaromatic ring are considered to refer to simple aromatic rings, such as benzene, biphenyl, terphenyl, naphthalene, phenanthrene, etc., or simple heteroaromatic rings, such as pyridine, pyrimidine, thiophene, pyrazole, oxazole, triazole, etc., or fused aryl or heteroaryl groups, such as anthracene, fluoranthene, etc. Quinoline, isoquinoline, benzofuran, benzothiophene, indazole, quinazoline, quinoxaline, thiophene-pyridine, benzothiophene-pyridine, etc.

[0019] An alkyl group in the sense of the present application having 1 to 40 carbon atoms is preferably understood to mean methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, neopentyl, cyclopentyl, n-hexyl, neohexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl. A heteroalkyl group having 1 to 40 carbon atoms in the sense of the present application is understood to mean an alkyl group in which an individual hydrogen atom or -CH2- group can be replaced by an oxygen, sulfur or halogen atom, by an alkoxy group, an alkylthio group, a fluorinated alkoxy group, a fluorinated alkylthio group, in particular by a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a methylthio group, an ethylthio group, an n-propylthio group, an isopropylthio group, an n-butythio group, an isobutylthio group, a sec-butythio group, a tert-butythio group, a trifluoromethylthio group, a trifluoromethoxy group, a pentafluoroethoxy group, a pentafluoroethylthio group, a 2,2,2-trifluoroethoxy group, a 2,2,2-trifluoroethylthio group, an ethenyloxy group, an ethenylthio group, a propenyloxy group, a propenylthio group, a butenylthio group, a butenyloxy group, a pentenyloxy group, a pentenylthio group, a cyclopentenylthio group, a cyclopentenylthio group, a hexenyloxy group, a hexenylthio group, a cyclohexenylthio group, a cyclohexenylthio group, an ethynyloxy group, an ethynylthio group, a propynyloxy group, a propynylthio group, a butynyloxy group, a butynylthio group, a pentynyloxy group, a pentynylthio group, a hexynyloxy group, a hexynylthio group.

[0020] An alkenyl or alkynyl group in the sense of the present application is preferably understood to mean cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl.

[0021] An alkoxy group in the sense of the present application having 1 to 40 carbon atoms is preferably understood to mean methoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, sec-pentoxy, 2-methylbutoxy, n-hexoxy, cyclohexoxy, n-heptoxy, cycloheptoxy, n-octoxy, cyclooctoxy, 2-ethylhexoxy, pentafluoroethoxy and 2,2,2-trifluoroethoxy.

[0022] Generally, the cycloalkyl and cycloalkenyl groups according to the present application can be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptyl, cycloheptenyl, in which one or more -CH2- groups can be replaced by the above-mentioned groups; furthermore, one or more hydrogen atoms can also be replaced by a deuterium atom, a halogen atom or a nitrile group.

[0023] An aralkyl or arylalkyl group in the sense of the present application is used interchangeably and means an alkyl group which is substituted by an aryl group. Furthermore, the aralkyl group can optionally be substituted.

[0024] "Halogen," "halo," "halogen atom," and "halo group" are used interchangeably herein and refer to fluoro, chloro, bromo or iodo.

[0025] "Acyi" in the sense of the present invention refers to a substituted carbonyl group (COR).

[0026] "Ester" in the sense of the present invention refers to a substituted oxycarbonyl group (-OCOR or CO2R).

[0027] "Ether" in the sense of the present invention refers to a -OR group.

[0028] "Sulfanyl" or "sulfide" as described herein are used interchangeably and refer to a -SR group.

[0029] "Sulfinyl" in the sense of the present invention refers to a -SOR group.

[0030] "Sulfonyl" in the sense of the present invention refers to a -SO2R group.

[0031] "Phosphino" in the sense of the present invention refers to a -PR3 group, where each R can be the same or different.

[0032] "Silyl" in the sense of the present invention refers to a -SiR3 group, where each R can be the same or different.

[0033] "Seleno" in the sense of the present invention refers to a -SeR group.

[0034] Each R described above is preferably selected from the group consisting of C1-C6alkyl, C3-C6cycloalkyl, C6-C10aryl, C2-C10heteroaryl, and C3-C10heterocycloalkyl. 40 Each R described above is preferably selected from the group consisting of C1-C6alkyl, C3-C6cycloalkyl, C6-C10aryl, C2-C10heteroaryl, and C3-C10heterocycloalkyl. 40 Each R described above is preferably selected from the group consisting of C1-C6alkyl, C3-C6cycloalkyl, C6-C10aryl, C2-C10heteroaryl, and C3-C10heterocycloalkyl. 60 Each R described above is preferably selected from the group consisting of C1-C6alkyl, C3-C6cycloalkyl, C6-C10aryl, C2-C10heteroaryl, and C3-C10heterocycloalkyl. 60 Each R described above is preferably selected from the group consisting of C1-C6alkyl, C3-C6cycloalkyl, C6-C10aryl, C2-C10heteroaryl, and C3-C10heterocycloalkyl.

[0035] In many cases, the substituents are selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, aralkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxyl, ether, ester, nitrile, isonitrile, thio, sulfinyl, sulfonyl, and phosphino.

[0036] As used herein, "combinations thereof' or "group thereof' means that one or more members of the applicable list are combined to form a known or chemically stable arrangement that one of ordinary skill in the art would envision from the applicable list. For example, alkyl and deuterium can be combined to form a partially or fully deuterated alkyl group; halogen and alkyl can be combined to form a haloalkyl substituent, such as trifluoromethyl, and the like; and halogen, alkyl, and aryl can be combined to form a haloaralkyl group.

[0037] In one example, the term substituted includes combinations of two to four listed groups.

[0038] In another example, the term substituted includes combinations of two to three groups. In yet another example, the term substituted includes combinations of two groups. Preferred combinations of substituents are combinations containing up to fifty atoms other than hydrogen or deuterium, or combinations including up to forty atoms other than hydrogen or deuterium, or combinations including up to thirty atoms other than hydrogen or deuterium. In many cases, preferred combinations of substituents will include up to twenty atoms other than hydrogen or deuterium.

[0039] Further preferred, the substituents of the formula (I) include primarily the structures shown by RA1through RA100:

[0040]

[0041]

[0042]

[0043] wherein some or all of the hydrogen atoms in each group can be replaced by deuterium atoms.

[0044] Preferably, the compound that is a phosphorescent emitter in the organic electroluminescent device is a metal coordination complex having a metal-carbon bond, and has the formula M(L A ) x (L B ) y (L C ) z ; wherein L A is a first ligand, L B is a second ligand, L C is a third ligand, and L A , L B , L C may be the same or different;

[0045] The metal M is selected from the group consisting of Ir, Rh, Re, Ru, Os, Pt, Pd, and Au;

[0046] wherein x is 1, 2, or 3;

[0047] wherein y is 0, 1, or 2;

[0048] wherein z is 0, 1, or 2;

[0049] and x + y + z is the oxidation valence state of the metal M;

[0050] The oxidation state of the metal M, for example: Pt has an oxidation state of 2, Ir has an oxidation state of 3, Rh has an oxidation state of 3, and Pd has an oxidation state of 2.

[0051] Where L A L B and L C Each is independently selected from the group consisting of the following compounds:

[0052]

[0053] Or the aforementioned metal coordination complex, having the following structure:

[0054]

[0055] Each of the Ar1 groups mentioned above is independently selected from the group consisting of the following groups:

[0056]

[0057] Where L B and L C They can also be independent of each other:

[0058]

[0059] Each of R4, R5, R6, R7 or R8 can represent monosubstituted, disubstituted, trisubstituted, tetrasubstituted or unsubstituted;

[0060] Each of R4, R5, R6, R7, R8, or R9 is independently selected from hydrogen, deuterium, halogen atom, nitrile group, acyl group, carboxyl group, ether group, ester group, isonitrile group, thioyl group, selenyl group, sulfinyl group, sulfonyl group, phosphinyl group, substituted or unsubstituted C1-C1 atoms. 40 Straight-chain alkyl, substituted or unsubstituted C1-C 40 Straight-chain heteroalkyl, substituted or unsubstituted C3-C 40 Branched or cyclic alkyl groups, substituted or unsubstituted C3-C6 40 Branched or cyclic heteroalkyl groups, substituted or unsubstituted C1-C1 40 Straight-chain alkoxy, substituted or unsubstituted C3-C 40 Branched or cyclic alkoxy groups, substituted or unsubstituted C6-C 60 arylalkyl, substituted or unsubstituted C6-C 60 aryloxy group, substituted or unsubstituted C6-C 60 Aromatic amino group, substituted or unsubstituted C3-C 40 Silyl, substituted or unsubstituted C2-C 40 Alkenyl, substituted or unsubstituted C4-C 40cycloalkenyl, substituted or unsubstituted C2-C 40 heteroalkenyl, substituted or unsubstituted C2-C 40 alkynyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C2-C 60 heteroaryl, and wherein any two or more adjacent substituents can optionally be joined together to form a ring, or to form a polydentate ligand;

[0061] wherein X is selected from -0-, -S-, -S(=0)-, -S(02)-, -Se-, -C(R'R")-, -Si(R'R")-, -C(=0)-, or -N(R')-;

[0062] wherein each T is independently selected from -B(R')-, -N(R')-, -P(R')-, -0-, -S-, -Se-, -S(=0)-, -S(02)-, -C(R'R")-, -Si(R'R")-, or -Ge(R'R")-, and R', R" are each independently selected from substituted or unsubstituted C1-C 40 straight-chain alkyl, substituted or unsubstituted C1-C 40 straight-chain heteroalkyl, substituted or unsubstituted C3-C 40 branched or cyclic alkyl, substituted or unsubstituted C3-C 40 branched or cyclic heteroalkyl, substituted or unsubstituted C6-C 60 arylalkyl, substituted or unsubstituted C3-C 40 silyl, substituted or unsubstituted C2-C 40 alkenyl, substituted or unsubstituted C4-C 40 cycloalkenyl, substituted or unsubstituted C2-C 40 heteroalkenyl, substituted or unsubstituted C2-C 40 alkynyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C2-C 60 heteroaryl; R', R" can optionally be joined or fused to form a ring;

[0063] wherein at least one R4, R5, R6, R7, or R8 present in said compound comprises at least one substituent of formula (I).

[0064] In one preferred example, said metal M is Ir or Pt.

[0065] In a preferred example, each R4, R5, R6, R7or R8present in the compound is independently selected from the group consisting of RA1-RA100or the group consisting of RB1-RB65as described above, and at least one of R4, R5, R6, R7or R8present in the compound is selected from the group consisting of RA1-RA100; wherein the RB1-RB65are as shown below:

[0066]

[0067]

[0068] wherein some or all of the hydrogen atoms in each group can be replaced by deuterium atoms.

[0069] In a preferred example, the ligand L A , L B , L C is selected from any one of the following L1-L232structures or combinations thereof:

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078] wherein some or all of the hydrogen atoms in each group can be replaced by deuterium atoms. Preferably, the L B may also be selected from any one of the following LB1-LB432structures or combinations thereof:

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092] Preferably, the L C may also be selected from any of the following LC1 to LC60 structures or combinations thereof:

[0093]

[0094]

[0095]

[0096] wherein some or all of the hydrogen atoms in each structure can be replaced by deuterium atoms.

[0097] Preferably, x is 1, y is 2, and z is 0.

[0098] Preferably, x is 2, y is 1, and z is 0.

[0099] Preferably, x is 2, y is 0, and z is 1.

[0100] Preferably, x is 3, y is 0, and z is 0.

[0101] Preferably, the compound that is a phosphorescent emitter in the organic electroluminescent device is a metal coordination complex having a metal-carbon bond, having the structure shown below:

[0102]

[0103]

[0104]

[0105]

[0106]

[0107] wherein part of hydrogen atoms or all of the hydrogen atoms in each structure can be replaced with deuterium atoms.

[0108] To achieve the above-mentioned second object, the present application provides the following technical solutions:

[0109] An organic light emitting device comprising an anode, a cathode, and an organic layer disposed between the anode and the cathode, the organic layer comprising the compound described above as a phosphorescent emitter.

[0110] In a preferred example, the organic layer is an emission layer, and the compound serves as an emission dopant or a non-emission dopant.

[0111] In a preferred example, the organic layer further comprises a host material.

[0112] In a preferred example, the host material is selected from the group consisting of structures of the following formulae X-1 to X-11,

[0113]

[0114] wherein R a is selected from the group consisting of Y-1 to Y-13, which are shown as follows:

[0115]

[0116] Y-1 to Y-13:

[0117] each Z1, Z2is independently selected from the group consisting of hydrogen, deuterium, a halogen atom, a hydroxyl group, a nitrile group, a nitro group, an amino group, an amidine group, a hydrazine group, a hydrazone group, a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group, a phosphoric acid group, a phosphate group, a C1-C 60 alkyl group, a C2-C 60 alkenyl group, a C2-C 60 alkynyl group, a C1-C 60 alkoxy group, a C3-C 60 cycloalkyl group, a C3-C 60 cycloalkenyl group, a C6-C 60 aryl group, a C6-C 60 fused ring aryl group, a C6-C 60 aryloxy group, a C6-C 60 aryl sulfide group, or a C2-C 60 heterocyclic aryl group;

[0118] x1represents an integer of 1 to 4; x2represents an integer of 1 to 3; x3represents 1 or 2; x4represents an integer of 1 to 6; x5represents an integer of 1 to 5;

[0119] denotes the attachment of the substituent to the main structure;

[0120] T and R4 have the definitions given above.

[0121] In a preferred example, the organic light emitting device can be a consumer product, an organic light emitting device and / or a lighting panel.

[0122] The advantages of the present application are as follows:

[0123] The present application provides a compound which is a metal complex containing a novel boron-nitrogen five-membered heterocyclic group of formula (I) as a ligand. The introduction of the ligand containing the group of formula (I) can narrow the emission spectrum, reduce the sublimation temperature, and improve the luminous efficiency of the device. The introduction of these ligands containing formula (I) into iridium or platinum complexes can well improve the sublimation stability of the obtained iridium complexes, platinum complexes, and improve the phosphorescence quantum yield of these complexes. BRIEF DESCRIPTION OF DRAWINGS

[0124] Figure 1 A schematic diagram of an organic electroluminescent device 100 provided by the present application is shown.

[0125] Figure 1 Label: 110 - substrate, 115 - anode, 120 - hole injection layer, 125 - hole transport layer, 130 - electron blocking layer, 135 - light emitting layer, 140 - hole blocking layer, 145 - electron transport layer, 150 - electron injection layer, 155 - protective layer, 160 - cathode, 162 - first conductive layer, 164 - second conductive layer, 170 - barrier layer.

[0126] Figure 2 A schematic diagram of an inverted organic electroluminescent device 200 provided by the present application is shown.

[0127] Figure 2 Label: 210 - substrate, 215 - cathode, 220 - light emitting layer, 225 - hole transport layer, 230 - anode. DETAILED DESCRIPTION

[0128] In order to more clearly illustrate the present application, the present application will be described further with reference to the preferred embodiments and the attached drawings. Like components in the drawings are denoted by like reference numerals. Those skilled in the art will understand that the specific description given below is illustrative and not restrictive, and should not be construed as limiting the scope of the present application.

[0129] Generally, an organic light emitting device includes at least one organic layer disposed between and electrically connected to an anode and a cathode. Figure 1A schematic diagram of an organic light-emitting device 100 is shown. The diagram is not necessarily drawn to scale. Device 100 may include a substrate 110, an anode 115, a hole injection layer 120, a hole transport layer 125, an electron blocking layer 130, a light-emitting layer 135, a hole blocking layer 140, an electron transport layer 145, an electron injection layer 150, a protective layer 155, a cathode 160, and a barrier layer 170. The cathode 160 is a composite cathode having a first conductive layer 162 and a second conductive layer 164. Device 100 can be manufactured by sequentially depositing the described layers.

[0130] Figure 2 A schematic diagram of an inverted organic light-emitting device 200 is shown. The device includes a substrate 210, a cathode 215, a light-emitting layer 220, a hole transport layer 225, and an anode 230. The device 200 can be fabricated by sequentially depositing the layers described herein. Because the most common OLED devices have a cathode disposed on the anode, while device 200 has a cathode 215 disposed below the anode 230, device 200 can be referred to as an "inverted" organic light-emitting device. Materials similar to those described with respect to device 100 can be used in the corresponding layers of device 200. Figure 2 Provide an example of how some layers can be omitted from the structure of device 100.

[0131] Figure 1 and Figure 2 The simple layered structures described herein are provided as non-limiting examples, and it should be understood that embodiments of the invention can be used in combination with a wide variety of other structures. The specific materials and structures described are exemplary in nature, and other materials and structures can be used. A functional OLED can be realized by combining the described layers in different ways based on design, performance, and cost factors, or several layers can be omitted entirely. Other layers not specifically described may also be included. Materials different from those specifically described may be used. Although many examples provided herein describe various layers as comprising a single material, it will be understood that combinations of materials, such as mixtures of matrix and dopant, or more generally, mixtures, can be used. Furthermore, the layers may have various sublayers. The names given to the various layers herein are not intended to be strictly limiting. For example, in device 200, hole transport layer 225 transports holes and injects holes into light-emitting layer 220, and can be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED can be described as having an organic layer disposed between a cathode and an anode. This organic layer may comprise a single layer or may further comprise, as exemplified... Figure 1 and Figure 2 Multiple layers of different organic materials are described.

[0132] Structures and materials not specifically described can also be used, such as PLEDs containing polymer materials. As another example, OLEDs with a single organic layer or multiple stacks can be used. OLED structures can be detached from... Figure 1 and Figure 2 The simple layered structure is illustrated in the diagram. For example, the substrate may include angled reflective surfaces to improve optical coupling.

[0133] Unless otherwise specified, any of the layers in the various embodiments can be deposited by any suitable method. For organic layers, preferred methods include thermal evaporation, organic vapor deposition methods, or applying one or more layers by means of carrier gas sublimation, wherein, in 10 -5 The material is applied at a pressure between millibar and 1 bar. A particular example of this method is an organic vapor jet printing method, in which the material is applied directly through a nozzle and is therefore structured. Other suitable deposition methods include producing one or more layers, for example by spin coating, or by means of any desired printing method such as screen printing, flexographic printing, offset printing, photoinitiated thermal imaging, thermal transfer, inkjet printing, or nozzle printing. Soluble compounds, for example, are obtained through appropriate substitution. These methods are also particularly suitable for oligomers, dendritic macromolecules, and polymers. Furthermore, mixing methods are feasible, in which one or more layers are applied, for example, from a solution and one or more additional layers are applied by vapor phase deposition.

[0134] The device manufactured according to embodiments of the present invention may optionally further include a barrier layer. One use of the barrier layer is to protect the electrodes and organic layers from damage caused by exposure to harmful substances in the environment, including moisture, vapors, and / or gases. The barrier layer may be deposited on, under, or beside a substrate or electrode, or on any other part of the device, including edges. The barrier layer may comprise a single layer or multiple layers. The barrier layer can be formed using various known chemical vapor deposition techniques and may comprise compositions having a single phase as well as compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may incorporate inorganic or organic compounds, or both. Preferably, the barrier layer comprises a mixture of polymeric and non-polymeric materials. For it to be considered a mixture, the aforementioned polymeric and non-polymeric materials constituting the barrier layer should be deposited under the same conditions and / or simultaneously. The weight ratio of polymeric material to non-polymeric material may be in the range of 95 / 5 to 5 / 95. In one example, the mixture of polymeric and non-polymeric materials is essentially composed of polymeric silicon and inorganic silicon.

[0135] In any of the above-mentioned compounds used in each layer of the OLED device, the hydrogen atoms can be partially or fully deuterated. Thus, any specifically listed substituent, such as (but not limited to) methyl, phenyl, pyridyl, and the like, can be in its non-deuterated, partially deuterated, and fully deuterated forms. Similarly, substituent classes, such as (but not limited to) alkyl, aryl, cycloalkyl, heteroaryl, and the like, can also be in their non-deuterated, partially deuterated, and fully deuterated forms.

[0136] The materials and structures described herein can be applied in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors can use the materials and structures. Further, organic devices such as organic transistors can use the materials and structures.

[0137] These methods are generally known to the person of ordinary skill in the art and they can apply them without inventive effort to an organic electroluminescent device comprising a compound according to the present application.

[0138] According to one embodiment, novel ligands for metal complexes are disclosed. The inventors have found that the introduction of these trans double bond containing ligands unexpectedly narrows the emission spectrum, lowers the sublimation temperature, and increases the luminous efficiency of the device.

[0139] In order to more clearly illustrate the present application, the technical solutions of the present application are described below with reference to some specific embodiments:

[0140] In the embodiments of the present application, the performance detection conditions of the prepared electroluminescent device are as follows:

[0141] Luminance and chromaticity coordinates: tested using a spectral scanner PhotoResearch PR-715;

[0142] Current density and turn-on voltage: tested using a digital source meter Keithley 2420;

[0143] Power efficiency: tested using a NEWPORT 1931-C.

[0144] Synthetic examples

[0145] The present application also provides a preparation method of the ligand LA, LB, or LC comprising a group of formula (I), comprising the following scheme;

[0146]

[0147] wherein R is an aromatic or heteroaromatic ring, and the other symbols used are the same as defined above.

[0148] A specific preparation method, taking compound L40 as an example, comprises the following steps:

[0149] First step: preparation of compound Int0

[0150]

[0151] Under nitrogen protection, 20.0 mmol of sub-1 was dispersed in 120 mL of dry toluene, 40.0 mmol of o-phenylenediamine, 22.0 mmol of p-toluenesulfonic acid and 4.0 mmol of anhydrous magnesium sulfate were added, the reaction was stirred at reflux for 24 hours, then it was cooled to room temperature, filtered, the filtrate was concentrated under reduced pressure and dried, and then purified by silica gel column to obtain compound Int0, yellow solid, yield 75%.

[0152] Second step: preparation of compound L40

[0153]

[0154] Under nitrogen protection, 20.0 mmol of intermediate Int0 was dissolved in 80 mL of dry THF, cooled to 0°C, 45.0 mmol of 60% sodium hydride oil dispersion solid was added in batches, the reaction was stirred for 1 hour, 44.0 mmol of iodomethane-d3 was added, the temperature was raised to room temperature and the reaction was stirred for 15 hours, 20 mL of saturated brine was added dropwise, extracted with ethyl acetate, the organic phase was washed with saturated brine and water, dried, filtered, the filtrate was concentrated under reduced pressure and dried, and then purified by silica gel column to obtain compound L40, yellow solid, yield 92%, HRMS (MALDI-TOF): m / z = 306.20 [M+H] + .

[0155] Referring to the above similar synthesis method, compounds L1-L39, L41-L232 were prepared.

[0156] Example 1

[0157] Synthesis of metal complex M(L A ) x (L B ) y (L C ) Z :

[0158] (A) when x is 1, y is 2, z is 0, and M is Ir, the general preparation method of metal complex: Ir(L A )(L B )2, wherein L A is selected from any one of L1-L232, L B is selected from any one of LB1-LB432, comprising the following steps;

[0159] First step: preparation of triflate salt of double LB iridium complex:

[0160]

[0161] 10.0 mmol of compound LB and 4.5 mmol of IrCl3-3H2O were dispersed in 60 mL of ethylene glycol ether and 20 mL of water, and the reaction was carried out under reflux at elevated temperature for 24 hours under nitrogen protection, and then cooled to room temperature, filtered, and the filter cake was washed with water and ethanol and dried under vacuum to obtain a yellow solid. The obtained yellow solid was dissolved in 100 mL of dichloromethane and 10 mL of methanol, 5.0 mmol of silver trifluoromethanesulfonate was added, and the reaction was stirred for 24 hours, filtered, and the filtrate was concentrated under reduced pressure to obtain a trifluoromethanesulfonate of compound bis-LB iridium complex.

[0162] Second step: preparation of metal complex Ir(L A )(L B )2

[0163]

[0164] 4.8 mmol of compound LA and 2.3 mmol of trifluoromethanesulfonate of compound bis-LB iridium complex prepared in the first step were dispersed in 50 mL of ethylene glycol ether and 50 mL of DMF, and the reaction was carried out under stirring at 100°C for 7 days under nitrogen protection, and then cooled to room temperature, concentrated under reduced pressure, and purified by silica gel column chromatography eluted with dichloromethane-n-hexane to obtain metal complex Ir(L A )(L B )2, wherein L1~L232and LB1~LB432are the same as defined above.

[0165] Referring to the general preparation method of the above metal complex: Ir(L A )(L B )2, only the preparation of metal complex Ir(L36)(LB105)2will be described in more detail as an example:

[0166] First step: preparation of compound Int-1

[0167]

[0168] 10.0 g of compound LB105 and 9.5 g of IrCl3-3H2O were dispersed in 150 mL of ethylene glycol ether and 50 mL of water, and the reaction was carried out under reflux at elevated temperature for 24 hours under nitrogen protection, and then cooled to room temperature, filtered, and the filter cake was washed with water and ethanol and dried under vacuum to obtain 14.8 g of a yellow solid. The obtained yellow solid was dissolved in 250 mL of dichloromethane and 25 mL of methanol, 6.5 g of silver trifluoromethanesulfonate was added, and the reaction was stirred for 24 hours, filtered, and the filtrate was concentrated under reduced pressure to obtain compound Int-1 in a yield of 83%.

[0169] Second step: Preparation of the metal complex Ir(L36)(LB105)2

[0170]

[0171] 4.8 mmol of compound L36 and 2.3 mmol of intermediate Int-1 were dispersed in 50 mL of ethylene glycol ethyl ether and 50 mL of DMF, under nitrogen protection, the reaction was stirred at 100 °C for 7 days, cooled to room temperature, concentrated under reduced pressure, dried, and purified by silica gel column separation, eluted with dichloromethane-n-hexane, to obtain the metal complex Ir(L36)(LB105)2, yellow solid, yield: 44%, HRMS (MALDI-TOF): m / z = 991.41 [M + ].

[0172] Example 2

[0173] (B) x is 2, y is 1, z is 0, M is Ir, the general preparation method of the metal complex: Ir(L A )2(L B ), wherein L A is selected from any one of L1-L232, L B is selected from any one of LB1-LB432, comprises the following steps;

[0174] First step: Preparation of triflate salt of double LA iridium complex:

[0175]

[0176] Referring to the synthesis method of Example 1, first step, only replace LB in Example 1, first step, with LA, to prepare intermediate compound triflate salt of double LA iridium complex.

[0177] Second step: Preparation of the metal complex Ir(L A )2(L B )

[0178]

[0179] Referring to the synthesis method of Example 1, second step, only replace LA in Example 1, second step, with LB, and replace triflate salt of double LB iridium complex with triflate salt of double LA iridium complex, to obtain the metal complex Ir(L A )2(L B ).

[0180] The L1-L232 and LB1-LB432 are the same as the aforementioned definitions.

[0181] Referring to the general preparation method of the above metal complex: Ir(L A )2(L B ), only the preparation of the metal complex Ir(L66)2(LB78) is described in more detail as an example;

[0182] Preparation of the metal complex Ir(L66)2(LB78)

[0183] First step: preparation of compound Int-2

[0184]

[0185] 10.0 mmol of compound L66 and 4.5 mmol of IrCl3.3H2O were dispersed in 60 mL of ethylene glycol ethyl ether and 20 mL of water, under nitrogen protection, and heated to reflux for 24 hours. After cooling to room temperature, the mixture was filtered, the filter cake was washed with water and ethanol, and dried under vacuum to obtain a yellow solid. The obtained yellow solid was dissolved in 50 mL of dichloromethane and 5 mL of methanol, 20.0 mmol of silver trifluoromethanesulfonate was added, and the mixture was stirred for 24 hours. After filtration, the filtrate was concentrated under reduced pressure to obtain compound Int-2, a yellow solid, in a yield of 78%.

[0186] Second step: preparation of the metal complex Ir(L66)2(LB78)

[0187]

[0188] 5.0 mmol of compound LB78 and 2.5 mmol of intermediate Int-2 were dispersed in 15 mL of ethylene glycol ethyl ether and 15 mL of DMF, under nitrogen protection, and heated to 100°C for stirring for 7 days. After cooling to room temperature, the reaction solution was poured into 250 mL of ice water, extracted with dichloromethane, and the organic phase was collected, dried, filtered, and the filtrate was concentrated under reduced pressure and purified by silica gel column separation with dichloromethane-n-hexane elution to obtain the metal complex Ir(L66)2(LB78), a dark yellow solid, in a yield of 48%, HRMS (MALDI-TOF): m / z = 1096.66 [M + ].

[0189] Example 3

[0190] When (C)x is 3, y is 0, z is 0, and M is Ir, the general preparation method of the metal complex: Ir(L A )3, wherein L A is selected from any one of L1 to L232;

[0191] First step: preparation of a double LA iridium chloride bridge complex

[0192]

[0193] 5.0 mmol of compound LA and 2.5 mmol of IrCl3-3H2O were dispersed in 60 mL of ethylene glycol ethyl ether and 20 mL of water, and the reaction was carried out under refluxing with heating for 24 hours under nitrogen protection, and then cooled to room temperature, filtered, and the filter cake was washed with water and ethanol and dried under vacuum to obtain the double LA iridium chloride bridge complex.

[0194] Second step: preparation of metal complex Ir(L A )3

[0195]

[0196] 5.0 mmol of the double LA iridium chloride bridge complex prepared in the first step, 10.0 mmol of silver trifluoromethanesulfonate, and 12.0 mmol of LA were dispersed in 20 mL of ethylene glycol ethyl ether, and the reaction was carried out under refluxing with heating for 24 hours under nitrogen protection, and then cooled to room temperature, filtered, and the filter cake was dissolved in dichloromethane and purified by silica gel column to obtain the metal complex Ir(L A )3, wherein L1-L232 are the same as defined above.

[0197] Referring to the general preparation method of the metal complex Ir(LA)3described above, the preparation of the metal complex Ir(L28)3will be described in more detail as an example.

[0198] Preparation of metal complex Ir(L28)3

[0199] First step: preparation of compound Int-3

[0200]

[0201] 9.5 mmol of compound L28 and 4.5 mmol of IrCl3-3H2O were dispersed in 60 mL of ethylene glycol ethyl ether and 20 mL of water, and the reaction was carried out under refluxing with heating for 24 hours under nitrogen protection, and then cooled to room temperature, filtered, and the filter cake was washed with water and ethanol and dried under vacuum to obtain compound Int-3, yellow solid, yield: 68%.

[0202] Second step: preparation of metal complex Ir(L28)3

[0203]

[0204] 5.0 mmol of Int-3 prepared in the first step, 10.0 mmol of silver triflate and 12.0 mmol of L28 were dispersed in 20 mL of ethylene glycol ethyl ether, and stirred under reflux at an elevated temperature for 24 hours under nitrogen protection, cooled to room temperature, filtered, the filter cake was dissolved in dichloromethane, and purified by silica gel column separation to obtain the metal complex Ir(L28)3, brown solid, yield: 37%, HRMS (MALDI-TOF): m / z = 1057.69 [M + ].

[0205] Example 4

[0206] (D) when x is 2, y is 0, z is 1, and M is Ir, the general preparation method of the metal complex: Ir(L A )2(L C ), wherein L A is selected from any one of L1-L232, and L C is selected from any one of LC1-LC60, comprises the following steps:

[0207] First step: preparation of the double LA iridium chloro-bridged complex:

[0208]

[0209] Referring to the synthesis method of the first step of Example 3, the double LA iridium chloro-bridged complex was prepared.

[0210] Second step: preparation of the metal complex Ir(L A )2(L C )

[0211]

[0212] 5.0 mmol of the double LA iridium chloro-bridged complex prepared in the first step, 12.5 mmol of LC, and 50.0 mmol of base were dispersed in 40 mL of acetonitrile and 40 mL of chloroform, and stirred under reflux at an elevated temperature for 16 hours under nitrogen protection, cooled to room temperature, the reaction solution was poured into 120 mL of ice water, the organic phase was separated, the aqueous phase was extracted with dichloromethane, the organic phase was collected, dried, filtered, and the filtrate was concentrated under reduced pressure to dryness, and purified by silica gel column separation to obtain the metal complex Ir(L A )2(L C ), wherein L1-L232 are the same as defined above.

[0213] Referring to the general preparation method of the metal complex: Ir(L A )2(L C ) above, only the preparation of the metal complex Ir(L118)2(LC4) is taken as an example to be described in more detail.

[0214] Preparation of metal complex Ir(L118)2(LC4):

[0215] First step: Preparation of compound Int-4

[0216]

[0217] 9.5 mmol of compound L118 and 4.5 mmol of IrCl3·3H2O were dispersed in 60 mL of ethylene glycol ethyl ether and 20 mL of water, and the reaction was heated to reflux under nitrogen protection for 24 hours, cooled to room temperature, filtered, and the filter cake was washed with water and ethanol and dried under vacuum to obtain compound Int-4, a red solid, yield: 76%.

[0218] Second step: Preparation of metal complex Ir(L118)2(LC4)

[0219]

[0220] 5.0 mmol of Int-4 prepared in the first step, 12.5 mmol of LC4, and 50.0 mmol of anhydrous sodium carbonate were dispersed in 40 mL of acetonitrile and 40 mL of chloroform, and the reaction was stirred to reflux under nitrogen protection for 16 hours, cooled to room temperature, poured into 120 mL of ice water, and the organic phase was separated. The aqueous phase was extracted with dichloromethane, and the organic phase was collected, dried, filtered, and the filtrate was concentrated under reduced pressure to obtain metal complex Ir(L118)2(LC4), a red solid, yield: 55%, HRMS (MALDI-TOF): m / z = 1116.58 [M + ].

[0221] Example 5

[0222] (E) When M is Pt, the metal complex: Pt(L A ) x (L B ) y (L C ) Z The preparation method is similar to the above synthesis method, wherein x can be 1, y can be 1, and z can be 0; or x can be 1, y can be 0, and z can be 1; wherein L A is selected from any one of L1 to L232, L B is selected from any one of LB1 to LB432, L C is selected from any one of LC1 to LC60;

[0223] (F) When M is Pt, the compound as a phosphorescent emitter can also be selected from PT1 to PT72, and the preparation method is exemplified by PT60;

[0224]

[0225] Under nitrogen protection, 15.0 mmol of PL60 was dissolved in 150 mL of acetic acid, 16.5 mmol of K2PtCl4 and 1.5 mmol of tetrabutylammonium bromide were added, and the mixture was stirred to be heated to reflux for 15 hours, cooled to room temperature, concentrated to dryness under reduced pressure, extracted with dichloromethane, filtered, and the filtrate was concentrated to dryness under reduced pressure and purified by silica gel column separation to obtain compound PT60, yellow solid, yield: 59%. HRMS (MALDI-TOF): m / z = 983.31 [M + ]。

[0226] Referring to the similar synthesis method described above, compounds PT1-PT59 and PT61-PT72 were prepared.

[0227] Example 6

[0228] Preparation of an organic electroluminescent device

[0229] 1) The ITO conductive layer coated glass substrate was ultrasonically treated in a cleaning agent for 30 minutes, rinsed in deionized water, ultrasonically treated in a mixed solvent of acetone / ethanol for 30 minutes, baked to dryness in a clean environment, irradiated by a UV light cleaning machine for 10 minutes, and the surface was bombarded by a low-energy cation beam;

[0230] 2) The ITO glass substrate treated as above was placed in a vacuum chamber, vacuumed to less than 1 x 10 -5 Pa, compound DNTPD was further evaporated on the anode layer film as a hole injection layer, and TAPC was further evaporated as a hole transport layer, and the film thickness of each was

[0231] The structural formula of DNTPD and TAPC is as follows:

[0232]

[0233] 3) A layer of compound of the present application and a host material were further evaporated on the hole transport layer as an organic light-emitting layer of the device, wherein the compound of the present application was 3% of the mass of the host material, and the film thickness was

[0234] 4) Compound LiQ and ET205 were further evaporated on the light-emitting layer as an electron transport layer of the device, wherein the mass ratio of LiQ and ET205 was 1:1, and the film thickness was

[0235] The structural formula of LiQ and ET205 is as follows:

[0236]

[0237] 5) Continue to evaporate a layer of LiF on the organic light-emitting layer as the electron injection layer of the device, with an evaporation film thickness of 1 nm.

[0238] 6) Continue to evaporate aluminum metal on the electron transport layer as the cathode layer of the device, with an evaporation film thickness of 100 nm. The device provided by the present application is obtained.

[0239] Example 7

[0240] Preparation of electroluminescent devices RD1-RD4

[0241] According to the same procedure as in Example 6, the compound of the present application used in step 3) is replaced by RD-1-RD-8, and the host material is replaced by RH451, to obtain the electroluminescent devices RD1-RD8 provided by the present application.

[0242] wherein the structures of RD-1-RD-8 and RH451 are as follows:

[0243]

[0244] Preparation of device RD9 in Comparative Example 1

[0245] According to the same procedure as in Example 6, the compound of the present application used in step 3) is replaced by RD-9, and the host material is replaced by RH451, to obtain the comparative device RD9.

[0246]

[0247] The organic electroluminescent devices prepared according to the above process are subjected to the following performance tests:

[0248] The driving voltage and current efficiency of the electroluminescent devices RD1-RD9 prepared in the above examples and Comparative Example 1, as well as the lifetime of the devices, are measured using a digital source meter and a luminance meter. Specifically, the voltage at which the current density of the organic electroluminescent device reaches 10 mA / cm 2 when the voltage is increased at a rate of 0.1 V per second, i.e. the driving voltage, is measured, and the luminance at this time is also measured; the ratio of the luminance to the current density is the current efficiency; the LT95% lifetime test is as follows: using a luminance meter, the time for the luminance of the organic electroluminescent device to decay to 950 cd / m 2 at a constant current under a luminance of 1000 cd / m 2 is measured, in hours. The data listed in Table 1 are relative data compared to the comparative device RD9 (the test data are in parentheses).

[0249] Table 1, performance test results of RD1-RD9

[0250]

[0251] From the above, it is obvious that the organic light-emitting device made of the compound manufactured using the ligand containing the boron-nitrogen five-membered heterocyclic group of the present application has a low driving voltage, a higher luminous efficiency, and a more excellent LT95% lifetime performance, indicating that the compound of the present application is an excellent light-emitting material.

[0252] Example 8

[0253] Preparation of electroluminescent devices GD1-GD10

[0254] According to the same procedure as in Example 6, the compound of the present application used in step 3) is replaced by GD-1-GD-10, and the host material is replaced by H1, to obtain the electroluminescent device GD1-GD10 provided by the present application.

[0255] wherein the structures of GD-1-GD-10 and H1 are:

[0256]

[0257] Preparation of device GD11 in Comparative Example 2

[0258] According to the same procedure as in Example 6, the compound of the present application used in step 3) is replaced by GD-11, and the host material is replaced by H1, to obtain the electroluminescent device GD11 provided by the present application.

[0259]

[0260] The performance test results of the obtained devices GD1-GD11 are shown in Table 2 below, and the data listed in Table 2 are relative data compared with the comparative device GD11 (the test data are in parentheses).

[0261] Table 2, performance test results of GD1-GD11

[0262]

[0263]

[0264] From the above, it is obvious that the organic light-emitting device made of the compound manufactured using the ligand containing the boron-nitrogen five-membered heterocyclic group of the present application has a low driving voltage, a higher luminous efficiency, and a more excellent LT95% lifetime performance, indicating that the compound of the present application is an excellent light-emitting material.

[0265] Example 9

[0266] Preparation of electroluminescent devices BD1-BD3

[0267] According to the same procedure as in Example 6, the compound of the present application used in step 3) is replaced by BD-1~BD-3, and the host material is replaced by H2, to obtain the electroluminescent device BD1~BD3 provided by the present application.

[0268] wherein the structures of BD-1~BD-3 and H2 are as follows:

[0269]

[0270] Preparation of device BD4 according to Comparative Example 3

[0271] According to the same procedure as in Example 6, the compound of the present application used in step 3) is replaced by BD-4, and the host material is replaced by H2, to obtain the electroluminescent device BD4 provided by the present application.

[0272]

[0273] The performance test results of the obtained devices BD1~BD4 are shown in Table 3 below, and the data listed in Table 3 are relative data compared with the comparative device BD4 (the test data are in the brackets).

[0274] Table 3, performance test results of BD1~BD4

[0275]

[0276] As is evident from the above, the organic light-emitting device prepared by using the compound of the present application containing the boron-nitrogen five-membered heterocyclic group has lower driving voltage, higher luminous efficiency, and more excellent LT90% lifetime.

[0277] Obviously, the above embodiments of the present application are merely exemplary for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description, and it is impossible to enumerate all the embodiments here. Any obvious changes or variations derived from the technical solutions of the present application still fall within the protection scope of the present application.

Claims

1. A compound used as a phosphorescent emitter in an organic electroluminescent device, characterized in that, The compound has the formula M(L) A ) x (L B ) y (L C ) z ; where L A As the first ligand, L B As the second ligand, L C It is the third ligand, and L A L B L C They can be the same or different; The metal M is Ir; Where x is 1, 2 or 3; Where y is 0, 1, or 2; Where z is 0, 1, or 2; And x+y+z is the oxidation state of the metal M; Where L A Choose from any of the following structures: The L B Choose from any of the following structures: The L C For LC4: .

2. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer includes the compound as a phosphorescent emitter as described in claim 1.

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