Iridium complex based on aza-aromatic ring modified [3, 2, 1-de] acridine-5, 9-diketoquethionine ligand and organic electroluminescent device based on aza-aromatic ring modified [3, 2, 1-de] acridine-5, 9-diketoquethionine ligand

Abstract

The invention relates to an iridium complex based on an aza aromatic ring modified [3, 2, 1-de] acridine-5, 9-diketoquinothionine ligand and an organic electroluminescent device. Aza-aromatic ring groups such as pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, isoquinolyl or quinazolinyl are introduced into the site 3 of [3, 2, 1-de] acridine-5, 9-diketoquinothionine and the derivative thereof to obtain a main ligand structure, the rigidity of a ligand and a complex is increased, the luminescence color and efficiency of the complex are regulated and controlled, steric hindrance is realized, molecular accumulation is reduced, and the luminous efficiency of the complex is improved. And the non-radiative transition process of molecules is inhibited. The iridium complex has high photoluminescence quantum yield and short excited state lifetime, and has the characteristic of narrow band emission. At least one functional layer of the organic light-emitting device contains the iridium metal complex, the iridium metal complex is used as a guest material of a light-emitting layer, and the prepared organic light-emitting device is excellent in performance, has the characteristics of high external quantum efficiency and low efficiency roll-off, and has very high application value in the field of OLED display and illumination.

Description

Technical Field

[0001] The present invention relates to compounds for organic electronic devices, such as organic light-emitting devices. More particularly, it relates to a luminescent material comprising an iridium complex of [3,2,1-de]acridine-5,9-dionequinolinium main ligand modified with an azoaromatic ring and a series of complexes for preparing an organic electroluminescent device. Background Art

[0002] With the continuous advancement of science and technology, the importance of electroluminescent materials in the field of display and lighting has become increasingly prominent. Especially in organic light-emitting diode (OLED) technology, efficient and stable luminescent materials are the key to achieving high-performance display and lighting products. In recent years, metal complexes have become a hot topic in the study of electroluminescent materials due to their unique optoelectronic properties, such as high photoluminescence quantum yield, adjustable luminescence color and good stability. Among the many metal complexes, iridium (Ir) complexes have attracted much attention due to their excellent luminescence properties. Iridium complexes usually have high photoluminescence quantum yield and short excited state lifetime, which make them perform well in OLED devices. However, traditional iridium complexes still need to be improved in terms of luminescence color, efficiency and stability. In order to further improve the performance of iridium complexes, researchers are constantly exploring new ligand design and synthesis strategies.

[0003] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0004] The main purpose of the present invention is to solve the problems existing in the above-mentioned background technology and provide an iridium complex and an organic electroluminescent device based on a nitrogen heteroaromatic ring modified [3,2,1-de]acridine-5,9-dionequinolinium ligand.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A nitrogen heteroaromatic ring modified [3,2,1-de] acridine-5,9-dione quinolinium, characterized in that it has the following general structural formula:

[0007]

[0008] R1 represents a substituted or unsubstituted aromatic heterocyclic group;

[0009] R2-R8 are the same or different and are independently selected from hydrogen, halogen CF3, -CN, -OR, -Si(R')2, -N(R')2, -SR(R')2, -C(O)R', -C(O)OR', -C(O)NR', ​​-SOR', -SO2R', -SO3R', -P(O)(R')2, -P(O)(OR')R', -P(O)(OR')2, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl; the above alkyl C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl: R' in the same group may be the same or different, and is independently selected from: hydrogen, -CN, halogen, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C1-C40 haloalkyl;

[0010] or,

[0011] Any two adjacent groups in R2-R8 and the ring atoms to which they are connected form a 5-7 membered aryl or heteroaryl group, an 8-10 membered fused bicyclic aryl or heteroaryl group, or an 11-14 membered fused tricyclic aryl or heteroaryl group, and the above aryl or heteroaryl group may be substituted by any one or more substituents, and the substituents are independently selected from: halogen CF3, -CN, -OR, -Si(R')2, -N(R')2, -SR(R')2, -C (O)R', -C(O)OR', -C(O)NR', ​​-SOR', -SO2R', -SO3R', -P(O)(R')2, -P(O)(OR')R', -P(O)(OR')2, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl.

[0012] R' is selected from C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl; the above alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl are optionally substituted by one or more substituents, and the substituents are independently selected from: halogen, -CN, -OR', -N(R')2, -Si(R')3, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl: R' in the same group may be the same or different and are independently selected from: hydrogen, -CN, halogen, C1-C40 alkyl, C2-C40 alkenyl, C2C40 alkynyl, C1-C40 haloalkyl.

[0013] Preferably, in the nitrogen heteroaromatic ring modified [3,2,1-de] acridinium-5,9-dione quinolinone derivative of formula (1), R1 represents one or more hydrogen atoms, halogen CF3, -CN, -OR, -Si(R')2, -N(R')2, -SR(R')2, -C(O)R', -C(O)OR', -C(O)NR', ​​-SOR', -SO2R', -SO3R', -P(O)(R')2, -P(O)(OR')R', -P(O)(OR')2, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl The above alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl groups are optionally substituted by one or more substituents, and the substituents are independently selected from: halogen, -CN, -OR', -N(R')2, -Si(R')3, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl: R' in the same group may be the same or different, and are independently selected from: hydrogen, -CN, halogen, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C1-C40 haloalkyl substituted pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, isoquinolyl or quinazoline.

[0014] Further preferably, in the nitrogen heteroaromatic ring modified [3,2,1-de]acridine-5,9-dionequinolinone derivative of formula (1), R1 represents a substituted alkyl group at any position with one or more H, methyl, methoxy, trifluoromethyl, trimethylsilyl or triphenylsilyl.

[0015]

[0016] An iridium complex uses the nitrogen heteroaromatic ring modified [3,2,1-de] acridine-5,9-dione quinolinium as a main ligand, and uses picolinic acid or its derivatives, pyridine phosphonic acid or its derivatives, tetraphenylphosphimide or its derivatives, thiotetraphenylphosphimide or its derivatives, thiopicolinic acid or its derivatives, amidine derivatives, 2-(5-phenyl-1,3,4-oxadiazole-2-)phenol or its derivatives, 2-phenylpyridine or its derivatives, 2-(2-pyridyl)-diazolyl or its derivatives, 2-(2-pyridyl)-triazole or its derivatives, 8-(2-pyridyl)benzofuran[2,3-b]pyridine or its derivatives as auxiliary ligands.

[0017] Preferably, the general structural formula of the iridium complex is the following general formula (II):

[0018]

[0019] wherein R2-R10 are the same or different and are independently selected from hydrogen, halogen CF3, -CN, -OR, -Si(R')2, -N(R')2, -SR(R')2, -C(O)R', -C(O)OR', -C(O)NR', ​​-SOR', -SO2R', -SO3R', -P(O)(R')2, -P(O)(OR')R', -P(O)(OR')2, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl; Alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl are optionally substituted with one or more substituents independently selected from: halogen, -CN, -OR', -N(R')2, -Si(R')3, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl: R' in the same group may be the same or different, independently selected from: hydrogen, -CN, halogen, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C1-C40 haloalkyl;

[0020] or,

[0021] Any two adjacent groups in R2-R10 and the ring atoms to which they are connected form a 5-7 membered aryl or heteroaryl group, an 8-10 membered fused bicyclic aryl or heteroaryl group, or an 11-14 membered fused tricyclic aryl or heteroaryl group, and the above aryl or heteroaryl group may be substituted by any one or more substituents, and the substituents are independently selected from: halogen CF3, -CN, -OR, -Si(R')2, -N(R')2, -SR(R')2, - C(O)R', -C(O)OR', -C(O)NR', ​​-SOR', -SO2R', -SO3R', -P(O)(R')2, -P(O)(OR')R', -P(O)(OR')2, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl;

[0022] R' is selected from C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl; the above alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl are optionally substituted by one or more substituents, and the substituents are independently selected from: halogen, -CN, -OR', -N(R')2, - Si(R')3, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl: R' in the same group may be the same or different and are independently selected from: hydrogen, -CN, halogen, C1-C40 alkyl, C2-C40 alkenyl, C2C40 alkynyl, C1-C40 haloalkyl.

[0023] Preferably, the iridium complex of general formula (II) is specifically selected from the following complexes:

[0024]

[0025]

[0026] An electroluminescent device comprising:

[0027] anode,

[0028] cathode,

[0029] And an organic layer arranged between the anode and the cathode, wherein the organic layer comprises a light-emitting device prepared from the iridium complex according to claim 4.

[0030] Preferably, the organic layer comprises various charge transport layers and a light-emitting layer, and the light-emitting layer comprises a host material and the iridium complex as a light-emitting material for the light-emitting layer.

[0031] Preferably, the device emits light in a specific wavelength band (from ultraviolet light to near-infrared light) emitted by the iridium complex, or the device is prepared by a device preparation process, wherein the preparation process includes stacking multiple light-emitting layers and doping other light-emitting materials, wherein any light-emitting layer uses the iridium complex to emit mixed light.

[0032] A method for preparing an electroluminescent device comprises the following steps:

[0033] Ligand synthesis: synthesizing the nitrogen heteroaromatic ring modified [3,2,1-de] acridine-5,9-dione quinolinium as a ligand through chemical reaction;

[0034] Iridium complex synthesis: The synthesized ligand reacts with an iridium source to synthesize an iridium complex through coordination chemistry;

[0035] Preparation of light-emitting device: The synthesized iridium complex is applied as a light-emitting material to the light-emitting layer of the light-emitting device. Preferably, the light-emitting device is an organic electroluminescent device OLED, comprising a substrate anode, a hole injection layer, a hole transport layer, an electron blocking layer, the organic light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection material and a cathode, and the organic light-emitting layer comprises a main material and the iridium complex as a light-emitting material.

[0036] The term "halogen" in the present invention refers to F, Cl, Br, I.

[0037] The term "alkyl", "alkoxy", "haloalkyl" and any substituent containing the "alkyl" part of the present invention include branched or straight chain alkyl groups optionally with at least one substituent, optionally interrupted by at least one heteroatom, preferably C1-C40 alkyl, C1-C20 alkyl, more preferably C1-C8 alkyl, and particularly preferably C1-C6 alkyl, such as: methyl, ethyl, propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, n-hexyl, isohexyl, heptyl, isoheptyl, octyl, isooctyl, etc. In addition, the alkyl group is optionally substituted with one or more substituents, preferably halogen, more preferably F, C1-C20 haloalkyl, C1-C8 haloalkyl, C1-C4 haloalkyl, and most preferably CF3, perfluoroethyl, trifluoroethyl, perfluoropropyl, and perfluorobutyl.

[0038] The term "alkenyl" of the present invention includes branched or straight chain alkenyl groups optionally with at least one substituent, optionally interrupted by at least one heteroatom, preferably C2-C40 alkenyl, C1-C20 alkenyl, more preferably C2-C8 alkenyl, particularly preferably C2-C6 alkenyl, for example: vinyl, propenyl, butenyl, pentenyl, etc.

[0039] The term "alkynyl" of the present invention includes branched or straight chain alkynyl groups optionally with at least one substituent and optionally interrupted by at least one heteroatom, preferably C2-C40 alkynyl groups, C2-C20 alkynyl groups are more preferably C2-C8 alkynyl groups, and particularly preferably C2-C6 alkynyl groups, for example: ethynyl, propynyl, butynyl, pentynyl and the like.

[0040] The term "cycloalkyl" of the present invention includes substituted or unsubstituted saturated cycloalkyl groups, which may contain a monocyclic ring of 4-8, preferably 56 ring atoms or a polycyclic ring system of 6-40, preferably 6-20, 6-13, more preferably 9-13 ring atoms. Specific examples include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-norbornyl, 2-norbornyl, bicyclo[2.2.1]heptyl, bicyclo[2,2,2]octyl, but are not limited thereto.

[0041] The term "heterocycloalkyl" of the present invention refers to a cycloalkyl group containing 1 to 4 heteroatoms selected from N, O, S as cycloalkyl backbone atoms and carbon atoms as the remaining cycloalkyl backbone atoms. The heterocycloalkyl can be a 3-, 4-, 5-, 6-7- or 8-membered monocyclic heterocycloalkyl or a polycyclic system having 6-40, preferably 6-20, 6-13, more preferably 9-13 ring atoms. Specific examples include: morpholinyl, thiomorpholinyl, but are not limited thereto.

[0042] The term "aryl" of the present invention refers to an organic group derived from aromatic hydrocarbons by removing a hydrogen atom, and may contain a monocyclic ring of 4-8, preferably 5-6 ring atoms or a condensed ring system of 6-40, preferably 6-20, 6-13, more preferably 9-13 ring atoms. Specific examples include: phenyl, naphthyl, diphenyl, anthracenyl, tetrahydronaphthyl, indenyl, fluorenyl, phenanthrenyl, triphenylenyl, pyrenyl, pyrenyl, tetraphenyl and fluoranthenyl, but are not limited thereto.

[0043] The term "heteroaryl" of the present invention refers to an aryl group containing 1 to 4 heteroatoms selected from N, O, S, P as aromatic ring backbone atoms, and carbon atoms as the remaining aromatic ring backbone atoms. Heteroaryl can be a 5-, 6-, 7- or 8-membered monocyclic heteroaryl or a polycyclic heteroaryl fused to one or more benzene rings, which can be partially saturated, and the polycyclic heteroaryl can contain 6-40, preferably 6-20, more preferably 9-13 ring atoms. Specific examples include monocyclic heteroaryl groups such as furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, oxazolyl, isoxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, tetrazolyl, furazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl and the like; polycyclic heteroaryl groups such as benzofuranyl, benzothienyl, isobenzofuranyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benzisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, quinazolinyl, quinolizinyl, quinoxalyl, carbazolyl, phenanthridinyl and benzodioxolyl, but are not limited thereto.

[0044] The term "carboxyl" of the present invention refers to "R a -C00-", where R a It refers to alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, and each group is as defined above.

[0045] The term "substituted" of the present invention refers to optional substitution by at least one substituent, including but not limited to monosubstitution, disubstitution, trisubstitution, tetrasubstitution, pentasubstitution and the like.

[0046] The "solid line" connecting the metal iridium and the ligand used in the general structural formula of the present invention refers to a coordinate covalent bond, which includes but is not limited to a single bond, a double bond, and the like.

[0047] The nitrogen heteroaromatic ring modified [3,2,1-de]acridine-5,9-dione quinolinium of the present invention can be prepared by reacting an aniline derivative with a 2-iodobenzoic acid methyl ester derivative to obtain a 2,2'-dibenzoic acid methyl ester aniline derivative, and then nitrogen-iodosuccinimide and a 2,2'-dibenzoic acid methyl ester aniline derivative are subjected to a 3-iodo-(2,2'-dibenzoic acid methyl ester) aniline derivative, and then a Friedel-Crafts acylation ring-closing reaction is performed to obtain a 3-iodo [3,2,1-de]acridine-5,9-dione quinolinium precursor, and then the 3-position is brominated and a coupling reaction is performed with the boronic acid of the nitrogen heteroaromatic ring to obtain the obtained product.

[0048] The iridium complex of the present invention can be prepared by conventional methods, for example, the main ligand and IrCl are refluxed in a mixed solution of ethoxyethanol and water at a ratio of 2:1 for 2 hours, cooled and filtered to obtain the iridium chloride bridge complex: then the iridium chloride bridge complex and the diketone auxiliary ligand of the corresponding structure are refluxed in ethoxyethanol for 2 hours to obtain a crude product of the iridium complex, column chromatography to obtain a pure product, and further sublimation and purification under vacuum conditions to obtain a luminescent material that meets the requirements for preparing OLED devices.

[0049] Another object of the present invention is to provide the nitrogen heteroaromatic ring modified [3,2,1-de]acridine-5,9-dionequinolinium or the iridium complex of the present invention as a luminescent material for preparing an organic electroluminescent device.

[0050] The iridium complex of the present invention can be used to prepare OLED devices, for example, an organic electroluminescent device includes a substrate anode, a hole injection material, a hole transport layer, an electron blocking layer, an organic light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection material and a cathode. The substrate is glass, the anode is indium tin oxide (ITO), the hole injection layer is 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), the hole layer uses 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline (TAPC), the electron blocking layer uses 4,4',4"-tri(carbazole-9-yl)triphenylamine (TCTA), the hole blocking layer uses 2,4,6-tris[3-(diphenylphosphinoyl)phenyl]-1,3, The invention discloses an organic light-emitting layer comprising a main material and a light-emitting material, wherein the main material is 5-(3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl)-7,7-dimethyl-5,7-dihydroindole[2,1-b]carbazole (DMIC-Trz), and the light-emitting material is the iridium complex described in the present invention.

[0051] The present invention has the following beneficial effects:

[0052] The present invention provides a novel iridium complex having an azaaromatic ring derivative introduced into the 3rd position of [3,2,1-de]acridine-5,9-dionequinocin and the derivative thereof as a main ligand. The present invention introduces azaaromatic ring groups such as pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, isoquinolyl or quinazoline into the 3rd position of [3,2,1-de]acridine-5,9-dionequinocin and its derivatives to obtain a main ligand structure, thereby increasing the rigidity of the ligand and the complex, regulating the luminescent color and efficiency of the complex, achieving steric hindrance, reducing molecular stacking, and inhibiting the non-radiative transition process of the molecule. The iridium complex of the present invention has a high photoluminescence quantum yield and a short excited state lifetime, and has the characteristics of narrow-band emission. The present invention also provides an organic electroluminescent device, at least one functional layer of which contains the iridium metal complex. The complex is used as the guest material of the light-emitting layer to prepare a blue-green light OLED device. The device prepared using the iridium complex of the present invention has excellent performance, high external quantum efficiency and low efficiency roll-off characteristics, and has potential application value in the field of OLED display and lighting.

[0053] The iridium complex of the present invention has a main ligand structure in which an azaaromatic ring group is introduced into the 3rd position of [3,2,1-de]acridine-5,9-dionequinoxaline. This design not only increases the rigidity of the ligand and the complex, but also effectively regulates the luminescent color and efficiency of the complex by regulating the type and position of the azaaromatic ring. In addition, the introduction of the azaaromatic ring also realizes a steric hindrance effect, reduces the accumulation between molecules, thereby inhibiting the non-radiative transition process of the molecule and improving the luminescent efficiency.

[0054] In the present invention, the selection of nitrogen heteroaromatic rings includes but is not limited to pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, isoquinolyl and quinazoline. The introduction of these groups not only enriches the chemical diversity of the ligands, but also provides more degrees of freedom for regulating the photoelectric properties of the iridium complex by changing the electronic structure and spatial configuration of the ligands. For example, the introduction of pyridyl and pyrimidyl can enhance the electron donor ability of the ligand, thereby improving the luminescence efficiency of the complex; while the introduction of pyrazinyl and pyridazinyl can adjust the luminescent color of the complex, realizing the regulation from blue light to green light.

[0055] The iridium complexes of the present invention are not only innovative in theory, but also show excellent performance in practical applications. OLED devices prepared using these iridium complexes show high external quantum efficiency and low efficiency roll-off characteristics, which makes them have great application potential in the field of OLED display and lighting. In particular, in the fields of high-resolution display, flexible display and solid-state lighting, the iridium complexes of the present invention are expected to become a strong candidate for a new generation of electroluminescent materials.

[0056] In summary, the present invention successfully designs and synthesizes a series of novel iridium complexes by introducing a nitrogen heteroaromatic ring group at the 3-position of [3,2,1-de]acridine-5,9-dionequinoxaline. These complexes not only have the characteristics of high photoluminescence quantum yield and narrow-band emission, but also show excellent performance in OLED devices. With further research and development, these novel iridium complexes are expected to play an important role in the field of electroluminescent materials and promote the development of OLED display and lighting technology.

[0057] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is the single crystal structure of Example Compound 5 of the present invention.

[0059] Figure 2 This is the single crystal structure of the iridium complex Ir33 according to an embodiment of the present invention.

[0060] Figure 3 1 is the absorption and emission spectra of Example Compound 5 of the present invention.

[0061] Figure 4 The absorption and emission spectra of the iridium complex Ir38 according to the embodiment of the present invention are shown in FIG.

[0062] Figure 5 This is a schematic diagram of the structures of various types of transport layer and main layer materials used in preparing devices according to the iridium complex examples Ir14, Ir28, Ir33 and Ir42 of the embodiments of the present invention.

[0063] Figure 6 The device emission spectra of the iridium complex examples Ir14, Ir28, Ir33 and Ir42 in the present invention. DETAILED DESCRIPTION

[0064] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0065] The terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art.

[0066] The present invention is further described in detail below in conjunction with specific examples and with reference to data. It should be understood that this embodiment is only for illustrating the present invention and is not intended to limit the scope of the present invention in any way.

[0067] In the following examples, various processes and methods not described in detail are conventional methods well known in the art.

[0068] Example 1: Preparation of the Iridium Complex of the Present Invention

[0069]

[0070] Synthetic routes of ligands and iridium complexes.

[0071]

[0072] Preparation of compound 1 in the above route: Add aniline (4.89 ml, 53.7 mmol), base 2-iodobenzoic acid methyl ester (23.7 ml, 161 mmol), potassium carbonate (K2CO3) (15.6 g, 113 mmol), Copper (Cu) (0.68 g, 10.7 mmol), cuprous iodide (CuI) (0.51 g, 2.69 mmol) and dibutyl ether (50 ml). The mixture was then stirred under reflux conditions for 48 hours under an argon atmosphere to promote the reaction. After the reaction was completed, the crude product was purified by column chromatography using a solvent system of n-hexane and ethyl acetate in a ratio of 4:1. The purified product was then recrystallized from ethanol to obtain a white solid 2,2'-(phenylazodiyl) dibenzoate (15.7 g, 81% yield). 1 H NMR (400MHz, CDCl3) δ (ppm): 7.65 (dd, J=7.7, 1.6Hz, 2H), 7.43-7.39 (m, 2H), 7.20-7.11 (m, 6H), 6.88-6.84 (m, 1H), 6.77-6.75 (m, 2H), 3.39 (s, 6H).13C NMR (100MHz, CDCl3) δ (ppm): 168.0, 148.6, 146.6, 132.8, 131.1, 129.1, 128.8, 128.0, 124.1, 121.8, 120.8, 51.9.HRMS (ESI-MS) [M+H]+Calculated: (C 22 H 19 NO4)362.1387; Found: 362.1387.

[0073]

[0074] Preparation of compound 2 in the above route: In a 100 ml double-necked round-bottom flask, 3.6 g (10 mmol) of dimethyl 2,2'-(phenylazodiyl) dibenzoate and 30 ml of acetonitrile were first added. After complete dissolution, a solution of 2.7 g (12 mmol) of N-iodosuccinimide dissolved in 20 ml of acetonitrile was added dropwise to the flask and stirred continuously. The mixture was stirred at room temperature for 2 hours to ensure that the reaction was complete. Subsequently, the reaction was terminated by adding 10 ml of 0.1 molar sodium hydroxide solution. The mixture was then extracted with 50 ml of dichloromethane (DCM). The organic layer was carefully separated and washed with water (50 ml each time, 3 times in total) to remove any residual inorganic matter. After removing the aqueous phase, the organic layer was dried over anhydrous magnesium sulfate to remove moisture. After filtration, the solution was concentrated under reduced pressure to obtain a crude product. This crude product was purified by silica gel column chromatography using a solvent system of n-hexane and ethyl acetate in a ratio of 10: 1. The purification process ultimately gave the desired product in a yield of 4.09 g (84%) as a white solid. 1 H NMR (400MHz, CDCl3) δ7.71 (dd, J=7.7, 1.7Hz, 2H), 7.49 (ddd, J=8.1, 7.4, 1.7H z, 2H), 7.46–7.42 (m, 2H), 7.27–7.21 (m, 4H), 6.52–6.48 (m, 2H), 3.46 (s, 6H). 13 C NMR (126MHz, CD2Cl2) δ167.29, 148.56, 145.65, 137.60, 132.81, 130.96, 129. 08, 128.20, 124.70, 121.85, 83.12, 53.89, 53.68, 53.46, 53.25, 53.03, 51.75.

[0075]

[0076] Preparation of compound 3 in the above route: 2,2'-(4-iodophenylimino)dimethyl benzoate (1.8 g, 5 mmol) was reacted with sodium hydroxide (1 g, 25 mmol) in a 20 ml ethanol / water (1:1) mixed solvent system. The mixture was heated under reflux for 12 hours, then cooled to room temperature and the pH was carefully adjusted to 2-3 with dilute hydrochloric acid to promote the precipitation of the diacid in solid form. The precipitate was separated by vacuum filtration, washed thoroughly with water to remove residual salt and hydrochloric acid, and then dried under vacuum.

[0077]

[0078] Preparation of compound 4 in the above route: Directly dried compound 3 was dispersed in 60 ml of dichloromethane under a nitrogen atmosphere. Then sulfuryl chloride (0.7 ml, 10.0 mmol) and a small amount of nitrogen, nitrogen-dimethylformamide (DMF) were added in sequence. The reaction was maintained under reflux conditions for 3 hours and then cooled to room temperature. Under a nitrogen atmosphere, aluminum chloride (6.7 g, 50 mmol) was slowly added to the cooled mixture to produce an exothermic reaction. The mixture was refluxed again for 12 hours, after which the reaction was terminated by carefully adding water and stirring vigorously, which was also an exothermic process. The reaction mixture was extracted with dichloromethane (50 ml each time, 3 times in total), and the organic layer was separated and concentrated under reduced pressure. The concentrated product was washed with n-hexane and recrystallized from boiling tetrahydrofuran (THF). The crystals obtained were collected by filtration to obtain 1.69 g (80%) of the desired product as a yellow solid. 1 H NMR (400MHz, CDCl3) δ8.93–8.84 (m, 3H), 8.56 (dd, J=8.0, 1.6Hz, 1H), 8.17 (dd, J=8.6, 0.9Hz, 1H), 8.08 (dd, J=9.0, 2.1Hz, 1H), 7.99 (d, J=9.0Hz, 1H), 7.88–7.78 (m, 2H), 7.64 (ddd, J=8.0, 7.1, 1.0Hz, 1H).13C NMR (101MHz, CDCl3) δ142.31, 139.59, 139.00, 136.73, 134.95, 134.76, 134.23, 128.28, 126.47, 12 4.73, 122.31, 120.47, 118.47, 115.64, 112.81, 109.98, 89.83.HRMS[M+H]+Calculated: 423.9834(C 20 H 11 INO2); Found: 423.9822.

[0079]

[0080] Preparation of ligand 5 in the above route: Preparation of ligand L1 in the above route: Pd2(dpa)3, (0.24 mmol), NaO t Bu (7.29mmol), product 4 (4.86mmol) and 2-pyridine boronic acid (7.29mmol) were added to a three-necked bottle under a nitrogen atmosphere. A mixed solvent of 1,4-dioxane and water was added thereto and stirred overnight at 100°C. After cooling, EA and water were extracted and the organic layer was concentrated. The residue was purified by silica gel column chromatography (eluent was PE / DCM=2 / 1, v / v) to obtain 0.43g of white solid L1 with a yield of 22%.1 H NMR (400MHz, CDCl3) δ9.01 (d, 1H), 8.79-73 (m, J=8.0, 1.6Hz, 3H), 8.53-8.50 (ddd, J=8.6, 0.9Hz, 2H), 8.26-8.16 (d, J=9.0, 2.1Hz, 1H ), 7.99-7, 96 (d, J=9.0Hz, 1H), 7.87-7.85 (dt, 1H), 7.73-7.65 (m, J=8.0, 7.1, 1.0Hz, 2H), 7.54-7.50 (ddd, 1H), 7.33-7.30 (ddd, 1H). 13 C NMR (101MHz, CDCl3) δ142.31, 139.59, 139.00, 136.73, 134.95, 134.76, 134.23, 128.28, 126.47, 12 4.73, 122.31, 120.47, 118.47, 115.64, 112.81, 109.98, 89.83.HRMS[M+H]+Calculated: 375.1128(C 25 H 14 N2O2); Found: 375.1136.

[0081]

[0082] Preparation of the iridium chloride bridge complex [Ir(L)2(u-C1)]2 in the above route: IrC13 (1 mmol) and ligand 5 (2.2 mmol) were added to a reaction flask, and a mixed solution of ethylene glycol diethyl ether / water (20 mL / 5 mL) was added under nitrogen. Refluxed at 130°C for 2 hours. After the reaction was completed, the temperature was lowered to room temperature and the chloride bridge was obtained by filtration with a yield of 85%.

[0083]

[0084] Preparation of the iridium complex Ir33 in the above route: The above iridium air bridge complex [Ir(L), (u-C1)] (0.25 mmol) and the auxiliary ligand acetylacetone (acac) (0.60 mmol) were dissolved in ethylene glycol ether (15 ml) and stirred for 6 h under a nitrogen atmosphere at 110°C. After cooling, the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica gel (PE / DCM=8 / 1, v / v) to obtain solid Ir33. Ir33: 1H NMR (400MHz, DMSO) δ9.07–8.39 (m, 9H), 8.21 (d, J=7.9Hz, 4H), 7.96 (t, J=7.9Hz, 2H), 7.63 (s, 5H), 7 .46(t, J=7.6Hz, 4H), 7.00(s, 2H), 5.63(s, 1H), 0.90(s, 18H).HRMS[M+H]+Calculated: 1123.3041(C 61 H 46 IrN4O6), Found: 1123.30247.

[0085] Other complexes Ir01-Ir64 were synthesized in the same way.

[0086]

[0087]

[0088] Example 2: Preparation of Iridium Complex Ir33 Organic Electroluminescent Device

[0089] The structure of the OLED device includes: the organic electroluminescent device includes a substrate anode, a hole injection material, a hole transport layer, an electron blocking layer, an organic light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection material and a cathode. The substrate is glass, the anode is indium tin oxide (ITO), the hole injection layer is 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), the hole layer uses 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline (TAPC), the electron blocking layer uses 4,4',4"-tri(carbazole-9-yl)triphenylamine (TCTA), the hole blocking layer uses 2,4,6-tris[3-(diphenylphosphinoyl)phenyl]-1,3,5-triazole (P O-T2T), the electron transport layer adopts 1,3,5-tris[(3-pyridyl)-3-phenyl]benzene (TmPyPb), the electron injection material is Liq, and the cathode is metal A1; the organic light-emitting layer includes a main material and a light-emitting material, the main material is 5-(3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl)-7,7-dimethyl-5,7-dihydroindole[2,1-b]carbazole (DMIC-Trz), the light-emitting material is an iridium complex Ir33, and the mass fraction of the iridium complex is 5wt%.

[0090] Table 1. Device performance parameters of some of the iridium complexes of the general formula (II) prepared in the present invention

[0091]

[0092] The iridium complex provided by the present invention can be used as a luminescent material in the light-emitting layer of OLEDs. By designing and optimizing the structure of the compound, the present invention achieves the purpose of regulating the efficiency and life of the device. It can be seen from the results in Table 1 below that the iridium complex of the present invention has excellent performance in device performance.

[0093] In summary, the [3,2,1-de]acridine-5,9-dionequinoxaline provided by the present invention introduces a nitrogen heteroaromatic derivative at the 3rd position to the iridium complex, which has the effect of regulating the luminescent color, efficiency and electron transport performance of the material, increasing the stability of the material, improving the efficiency of the device, and reducing the efficiency roll-off. The iridium complex described in the present invention has the characteristics of high photoluminescence quantum yield, short excited state lifetime and narrow-band emission. The device prepared using the iridium complex described in the present invention has excellent performance, and has the characteristics of low starting voltage, high external quantum efficiency, low efficiency roll-off and narrow-band emission, and has potential application value in the field of OLED lighting and display.

[0094] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A nitrogen heteroaromatic ring modified [3,2,1-de] acridine-5,9-dione quinolinium, characterized in that: It has the following general structural formula: R1 represents a substituted or unsubstituted aromatic heterocyclic group; R2-R8 are the same or different and are independently selected from hydrogen, halogen CF3, -CN, -OR, -Si(R')2, -N(R')2, -SR(R')2, -C(O)R', -C(O)OR', -C(O)NR', ​​-SOR', -SO2R', -SO3R', -P(O)(R')2, -P(O)(OR')R', -P(O)(OR')2, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl; the above alkyl C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl: R' in the same group may be the same or different, and is independently selected from: hydrogen, -CN, halogen, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C1-C40 haloalkyl; or, Any two adjacent groups in R2-R8 and the ring atoms to which they are connected form a 5-7 membered aryl or heteroaryl group, an 8-10 membered fused bicyclic aryl or heteroaryl group, or an 11-14 membered fused tricyclic aryl or heteroaryl group, and the above aryl or heteroaryl group may be substituted by any one or more substituents, and the substituents are independently selected from: halogen CF3, -CN, -OR, -Si(R')2, -N(R')2, -SR(R')2, -C (O)R', -C(O)OR', -C(O)NR', ​​-SOR', -SO2R', -SO3R', -P(O)(R')2, -P(O)(OR')R', -P(O)(OR')2, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl. R' is selected from C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl; the above alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl are optionally substituted by one or more substituents, and the substituents are independently selected from: halogen, -CN, -OR', -N(R')2, -Si(R')3, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl: R' in the same group may be the same or different and are independently selected from: hydrogen, -CN, halogen, C1-C40 alkyl, C2-C40 alkenyl, C2C40 alkynyl, C1-C40 haloalkyl.

2. The nitrogen heteroaromatic ring modified [3,2,1-de]acridine-5,9-dionequinolinium according to claim 1, characterized in that: R1 represents one or more hydrogen atoms, halogen CF3, -CN, -OR, -Si(R')2, -N(R')2, -SR(R')2, -C(O)R', -C(O)OR', -C(O)NR', ​​-SOR', -SO2R', -SO3R', -P(O)(R')2, -P(O)(OR')R', -P(O)(OR')2, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl; the above alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl , aryl and heteroaryl are optionally substituted by one or more substituents independently selected from the group consisting of: halogen, -CN, -OR', -N(R')2, -Si(R')3, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl: R' in the same group may be the same or different and are independently selected from the group consisting of: hydrogen, -CN, halogen, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C1-C40 haloalkyl substituted pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, isoquinolyl or quinazoline.

3. The nitrogen heteroaromatic ring modified [3,2,1-de]acridine-5,9-dionequinolinium according to claim 2, characterized in that: R1 represents any position substituted by one or more H, methyl, methoxy, trifluoromethyl, trimethylsilyl or triphenylsilyl 4. An iridium complex, characterized in that The main ligand is [3,2,1-de] acridine-5,9-dionequinolinium modified with a nitrogen heteroaromatic ring as described in any one of claims 1 to 3, and the auxiliary ligands are picolinic acid or its derivatives, pyridinephosphonic acid or its derivatives, tetraphenylphosphimide or its derivatives, thiotetraphenylphosphimide or its derivatives, thiopicolinic acid or its derivatives, amidine derivatives, 2-(5-phenyl-1,3,4-oxadiazole-2-)phenol or its derivatives, 2-phenylpyridine or its derivatives, 2-(2-pyridyl)-diazolyl or its derivatives, 2-(2-pyridyl)-triazole or its derivatives, 8-(2-pyridyl)benzofuran[2,3-b]pyridine or its derivatives.

5. The iridium complex according to claim 4, characterized in that The general structure is as follows: wherein R2-R10 are the same or different and are independently selected from hydrogen, halogen CF3, -CN, -OR, -Si(R')2, -N(R')2, -SR(R')2, -C(O)R', -C(O)OR', -C(O)NR', ​​-SOR', -SO2R', -SO3R', -P(O)(R')2, -P(O)(OR')R', -P(O)(OR')2, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl; Alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl are optionally substituted with one or more substituents independently selected from: halogen, -CN, -OR', -N(R')2, -Si(R')3, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl: R' in the same group may be the same or different, independently selected from: hydrogen, -CN, halogen, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C1-C40 haloalkyl; or, Any two adjacent groups in R2-R10 and the ring atoms to which they are connected form a 5-7 membered aryl or heteroaryl group, an 8-10 membered fused bicyclic aryl or heteroaryl group, or an 11-14 membered fused tricyclic aryl or heteroaryl group, and the above aryl or heteroaryl group may be substituted by any one or more substituents, and the substituents are independently selected from: halogen CF3, -CN, -OR, -Si(R')2, -N(R')2, -SR(R')2, - C(O)R', -C(O)OR', -C(O)NR', ​​-SOR', -SO2R', -SO3R', -P(O)(R')2, -P(O)(OR')R', -P(O)(OR')2, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl; R' is selected from C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl; the above alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl are optionally substituted by one or more substituents, and the substituents are independently selected from: halogen, -CN, -OR', -N(R')2, - Si(R')3, C1-C40 alkyl, C2-C40 alkenyl, C2-C40 alkynyl, C3-C40 cycloalkyl, C3-C40 heterocycloalkyl, C6-C40 aryl, C6-C40 heteroaryl: R' in the same group may be the same or different and are independently selected from: hydrogen, -CN, halogen, C1-C40 alkyl, C2-C40 alkenyl, C2C40 alkynyl, C1-C40 haloalkyl.

6. The iridium complex according to claim 4, characterized in that The iridium complex is selected from:

7. An electroluminescent device, characterized in that: include: anode, cathode, And an organic layer arranged between the anode and the cathode, wherein the organic layer comprises a light-emitting device prepared from the iridium complex according to claim 4.

8. The electroluminescent device according to claim 7, characterized in that The organic layer comprises various charge transport layers and a light-emitting layer, and the light-emitting layer comprises a host material and the iridium complex as claimed in claim 4 as a light-emitting material for the light-emitting layer.

9. The electroluminescent device according to claim 7, characterized in that The device emits light of a specific wavelength band emitted by the iridium complex described in claim 4, or the device is prepared by a device preparation process, wherein the preparation process includes stacking multiple light-emitting layers and doping other light-emitting materials, wherein any light-emitting layer uses the iridium complex described in claim 4 to emit mixed light.

10. A method for preparing an electroluminescent device, characterized in that: The following steps are involved: Ligand synthesis: synthesizing the nitrogen heteroaromatic ring modified [3,2,1-de] acridine-5,9-dione quinolinium as claimed in claim 1 as a ligand by chemical reaction; Iridium complex synthesis: The synthesized ligand reacts with an iridium source to synthesize an iridium complex through coordination chemistry; Preparation of light-emitting device: The synthesized iridium complex is applied as a light-emitting material to the light-emitting layer of the light-emitting device. Preferably, the light-emitting device is an organic electroluminescent device OLED, comprising a substrate anode, a hole injection layer, a hole transport layer, an electron blocking layer, the organic light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection material and a cathode, and the organic light-emitting layer comprises a main material and the iridium complex as a light-emitting material.

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