CN111100129B

CN111100129B - Organic electroluminescent material and device

Info

Publication number: CN111100129B
Application number: CN201811267706.9A
Authority: CN
Inventors: 王乐; 王强; 李长青; 牟勇; 姚剑飞; 毕欣; 邝志远; 夏传军
Original assignee: Beijing Summer Sprout Technology Co Ltd
Current assignee: Beijing Summer Sprout Technology Co Ltd
Priority date: 2018-10-29
Filing date: 2018-10-29
Publication date: 2023-06-27
Anticipated expiration: 2038-10-29
Also published as: CN111100129A

Abstract

An organic electroluminescent material and a device are disclosed. The organic electroluminescent material adopts a series of new indolocarbazole compounds, and can be used as a main material, a charge transport material and the like of an electroluminescent device. By using these compounds, better device performance, such as very low drive voltage, high efficiency, and longer lifetime, etc., can be provided.

Description

Organic electroluminescent material and device

Technical Field

The present invention relates to compounds for use in organic electronic devices, such as organic light emitting devices. In particular, to a novel indolocarbazole compound, and electroluminescent devices and compound formulations containing the same.

Background

Organic electronic devices include, but are not limited to, the following: organic Light Emitting Diodes (OLEDs), organic field effect transistors (O-FETs), organic light emitting transistors (OLEDs), organic photovoltaic devices (OPVs), dye-sensitized solar cells (DSSCs), organic optical detectors, organic photoreceptors, organic field effect devices (OFQDs), light emitting electrochemical cells (LECs), organic laser diodes and organic electroluminescent devices.

In 1987, tang and Van Slyke of Isomandah reported a double-layered organic electroluminescent device comprising an arylamine hole transport layer and a tris-8-hydroxyquinoline-aluminum layer as an electron transport layer and a light emitting layer (Applied Physics Letters,1987,51 (12): 913-915). Once biased into the device, green light is emitted from the device. The invention lays a foundation for the development of modern Organic Light Emitting Diodes (OLEDs). Most advanced OLEDs may include multiple layers, such as charge injection and transport layers, charge and exciton blocking layers, and one or more light emitting layers between the cathode and anode. Because OLEDs are self-emitting solid state devices, they offer great potential for display and lighting applications. Furthermore, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications, such as in flexible substrate fabrication.

OLEDs can be divided into three different types according to their light emission mechanism. The OLED of the Tang and van Slyke invention is a fluorescent OLED. It uses only singlet light emission. The triplet states generated in the device are wasted through non-radiative decay channels. Thus, the Internal Quantum Efficiency (IQE) of fluorescent OLEDs is only 25%. This limitation prevents commercialization of OLEDs. In 1997, forrest and Thompson reported phosphorescent OLEDs using triplet emission from heavy metals containing complexes as emitters. Thus, both singlet and triplet states can be harvested, achieving a 100% IQE. Because of its high efficiency, the discovery and development of phosphorescent OLEDs has contributed directly to the commercialization of Active Matrix OLEDs (AMOLEDs). Recently, adachi achieved high efficiency by Thermally Activated Delayed Fluorescence (TADF) of organic compounds. These emitters have a small singlet-triplet gap, making it possible for excitons to return from the triplet state to the singlet state. In TADF devices, triplet excitons can generate singlet excitons by reverse intersystem crossing, resulting in high IQE.

OLEDs can also be classified into small molecule and polymeric OLEDs depending on the form of the materials used. Small molecule refers to any organic or organometallic material that is not a polymer. The molecular weight of the small molecules can be large as long as they have a precise structure. Dendrimers with a defined structure are considered small molecules. Polymeric OLEDs include conjugated polymers and non-conjugated polymers having pendant luminescent groups. Small molecule OLEDs can become polymeric OLEDs if post-polymerization occurs during fabrication.

Various methods of OLED fabrication exist. Small molecule OLEDs are typically fabricated by vacuum thermal evaporation. Polymeric OLEDs are manufactured by solution processes such as spin coating, inkjet printing and nozzle printing. Small molecule OLEDs can also be fabricated by solution processes if the material can be dissolved or dispersed in a solvent.

The emission color of an OLED can be achieved by the structural design of the luminescent material. The OLED may include a light emitting layer or layers to achieve a desired spectrum. Green, yellow and red OLEDs, phosphorescent materials have been successfully commercialized. Blue phosphorescent devices still have problems of blue unsaturation, short device lifetime, high operating voltage, and the like. Commercial full color OLED displays typically employ a mixing strategy using blue fluorescent and phosphorescent yellow, or red and green. Currently, a rapid decrease in efficiency of phosphorescent OLEDs at high brightness remains a problem. In addition, it is desirable to have a more saturated emission spectrum, lower drive voltage, higher efficiency and longer device lifetime.

Carbazole and carbazole derivatives are widely applied to OLEDs, but the application potential of carbazole and carbazole derivatives in OLED materials is worth continuing intensive research and development. The present invention provides novel indolocarbazole compounds that can provide better device performance, such as longer device lifetime and lower drive voltages.

Disclosure of Invention

The present invention aims to provide a series of novel indolocarbazole compounds which address at least part of the above problems. The compounds are useful as host materials, charge transport materials, and the like in electroluminescent devices. By using these compounds, better device performance, such as very low drive voltage, high efficiency, and longer lifetime, etc., can be provided.

According to one embodiment of the present invention, a compound having formula 1 is disclosed:

wherein the method comprises the steps of

X ₁ To X ₈ ,Y ₁ To Y ₈ ,Z ₁ To Z ₁₂ Each independently selected from N, C or CR; and X is ₁ To X ₄ Any two of which are nitrogen, the remaining two are each independently selected from C or CR;

a is selected from CR ' R ', NR ', O, S or Se;

r, R ', R ", R'" are each independently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted arylalkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted amine having 0 to 20 carbon atoms, acyl, carbonyl, carboxylic acid groups, ester groups, nitrile groups, isonitrile groups, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

Two adjacent substituents can optionally be joined to form a ring; and when A is CR ' R ' or NR ' and, R ', R "and R '" are not both identical to Z ₁ To Z ₁₂ Form a ring.

According to another embodiment of the present invention, there is also disclosed an electroluminescent device including:

an anode is provided with a cathode,

a cathode electrode, which is arranged on the surface of the cathode,

and an organic layer disposed between the anode and the cathode, the organic layer comprising a compound having formula 1:

wherein the method comprises the steps of

a is selected from CR ' R ', NR ', O, S or Se;

According to still another embodiment of the present invention, there is also disclosed a compound formulation comprising the compound having the structure represented by formula 1.

The compound disclosed by the invention can be used as a main body material, a charge transport material and the like in an organic electroluminescent device. The compounds are readily useful in the manufacture of OLEDs and can provide better device performance, such as very low drive voltages, high efficiency, and longer lifetimes, among others.

Drawings

Fig. 1 is a schematic diagram of an organic light emitting device that may contain a compound or a compound formulation as disclosed herein.

Fig. 2 is a schematic view of another organic light emitting device that may contain a compound or a compound formulation as disclosed herein.

Fig. 3 is structural formula 1 showing a compound as disclosed herein.

Detailed Description

OLEDs can be fabricated on a variety of substrates, such as glass, plastic, and metal. Fig. 1 schematically illustrates, without limitation, an organic light-emitting device 100. The drawings are not necessarily to scale, and some of the layer structures in the drawings may be omitted as desired. The device 100 may include a substrate 101, an anode 110, a hole injection layer 120, a hole transport layer 130, an electron blocking layer 140, a light emitting layer 150, a hole blocking layer 160, an electron transport layer 170, an electron injection layer 180, and a cathode 190. The device 100 may be fabricated by sequentially depositing the layers described. The nature and function of the layers and exemplary materials are described in more detail in U.S. patent US7,279,704B2, columns 6-10, the entire contents of which are incorporated herein by reference.

There are more instances of each of these layers. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. patent No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is doped with F in a 50:1 molar ratio ₄ m-MTDATA of TCNQ as disclosed in U.S. patent application publication No. 2003/0230980, which is incorporated by reference in its entirety. Examples of host materials are disclosed in U.S. Pat. No. 6,303,238 to Thompson et al, which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li in a 1:1 molar ratio, as in U.S. patent application publication No. 2003/0230980, which is incorporated by reference in its entiretyDisclosed in (a). Examples of cathodes are disclosed in U.S. Pat. nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entirety, including composite cathodes having a thin layer of metal, such as Mg: ag, with an overlying transparent, electrically conductive, sputter deposited ITO layer. The principles and use of barrier layers are described in more detail in U.S. patent No. 6,097,147 and U.S. patent application publication No. 2003/0230980, which are incorporated by reference in their entirety. Examples of implant layers are provided in U.S. patent application publication No. 2004/0174116, which is incorporated by reference in its entirety. A description of protective layers can be found in U.S. patent application publication No. 2004/0174116, which is incorporated by reference in its entirety.

The above-described hierarchical structure is provided by way of non-limiting example. The function of the OLED may be achieved by combining the various layers described above, or some of the layers may be omitted entirely. It may also include other layers not explicitly described. Within each layer, a single material or a mixture of materials may be used to achieve optimal performance. Any functional layer may comprise several sublayers. For example, the light emitting layer may have two layers of different light emitting materials to achieve a desired light emission spectrum.

In one embodiment, an OLED may be described as having an "organic layer" disposed between a cathode and an anode. The organic layer may include one or more layers.

The OLED also requires an encapsulation layer, such as the organic light emitting device 200 shown schematically and without limitation in fig. 2, which differs from fig. 1 in that an encapsulation layer 102 may also be included over the cathode 190 to prevent harmful substances from the environment, such as moisture and oxygen. Any material capable of providing an encapsulation function may be used as the encapsulation layer, such as glass or an organic-inorganic hybrid layer. The encapsulation layer should be placed directly or indirectly outside the OLED device. Multilayer film packages are described in U.S. patent US7,968,146B2, the entire contents of which are incorporated herein by reference.

Devices manufactured according to embodiments of the present invention may be incorporated into a variety of consumer products having one or more electronic component modules (or units) of the device. Some examples of such consumer products include flat panel displays, monitors, medical monitors, televisions, billboards, lights for indoor or outdoor lighting and/or signaling, heads-up displays, displays that are fully or partially transparent, flexible displays, smart phones, tablet computers, tablet phones, wearable devices, smart watches, laptops, digital cameras, camcorders, viewfinders, micro-displays, 3-D displays, vehicle displays, and taillights.

The materials and structures described herein may also be used in other organic electronic devices as listed above.

As used herein, "top" means furthest from the substrate and "bottom" means closest to the substrate. In the case where the first layer is described as being "disposed" on "the second layer, the first layer is disposed farther from the substrate. Unless a first layer is "in contact with" a second layer, other layers may be present between the first and second layers. For example, a cathode may be described as "disposed on" an anode even though various organic layers are present between the cathode and the anode.

As used herein, "solution processable" means capable of being dissolved, dispersed, or transported in and/or deposited from a liquid medium in the form of a solution or suspension.

A ligand may be referred to as "photosensitive" when it is believed that the ligand directly contributes to the photosensitive properties of the emissive material. When it is believed that the ligand does not contribute to the photosensitive properties of the emissive material, the ligand may be referred to as "ancillary," but ancillary ligands may alter the properties of the photosensitive ligand.

It is believed that the Internal Quantum Efficiency (IQE) of fluorescent OLEDs can be limited by spin statistics that delay fluorescence by more than 25%. Delayed fluorescence can be generally classified into two types, i.e., P-type delayed fluorescence and E-type delayed fluorescence. The P-type delayed fluorescence is generated by triplet-triplet annihilation (TTA).

On the other hand, the E-type delayed fluorescence does not depend on the collision of two triplet states, but on the transition between the triplet states and the singlet excited state. Compounds capable of generating E-type delayed fluorescence need to have very small mono-triplet gaps in order for the conversion between the energy states. The thermal energy may activate a transition from the triplet state back to the singlet state. This type of delayed fluorescence is also known as Thermally Activated Delayed Fluorescence (TADF). A significant feature of TADF is that the delay component increases with increasing temperature. The fraction of backfill singlet excited states may reach 75% if the reverse intersystem crossing (iric) rate is sufficiently fast to minimize non-radiative decay from the triplet states. The total singlet fraction may be 100%, well in excess of 25% of the spin statistics of the electrically generated excitons.

Type E delayed fluorescence features can be found in excitation complex systems or in single compounds. Without being bound by theory, it is believed that E-delayed fluorescence requires a luminescent material with a small mono-triplet energy gap (Δe _S-T ). Organic non-metal containing donor-acceptor luminescent materials may be able to achieve this. The emission of these materials is typically characterized as donor-acceptor Charge Transfer (CT) type emission. The spatial separation of HOMO from LUMO in these donor-acceptor compounds generally results in a small Δe _S-T . These states may include CT states. Typically, donor-acceptor luminescent materials are constructed by linking an electron donor moiety (e.g., an amino or carbazole derivative) to an electron acceptor moiety (e.g., an N-containing six-membered aromatic ring).

Definition of terms for substituents

Halogen or halide-as used herein, includes fluorine, chlorine, bromine and iodine.

Alkyl-includes straight and branched alkyl groups. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, neopentyl, 1-methylpentyl, 2-methylpentyl, 1-pentylhexyl, 1-butylpentyl, 1-heptyloctyl, 3-methylpentyl. In addition, the alkyl group may be optionally substituted. The carbon in the alkyl chain may be substituted with other heteroatoms. Among the above, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl and neopentyl are preferred.

Cycloalkyl-as used herein, includes cyclic alkyl. Preferred cycloalkyl groups are cycloalkyl groups containing 4 to 10 ring carbon atoms, including cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-dimethylcyclohexyl, 1-adamantyl, 2-adamantyl, 1-norbornyl, 2-norbornyl and the like. In addition, cycloalkyl groups may be optionally substituted. The carbon in the ring may be substituted with other heteroatoms.

Alkenyl-as used herein, covers both straight chain and branched alkene groups. Preferred alkenyl groups are alkenyl groups containing 2 to 15 carbon atoms. Examples of alkenyl groups include vinyl, allyl, 1-butenyl, 2-butenyl, 3-butenyl, 1, 3-butadienyl, 1-methylvinyl, styryl, 2-diphenylvinyl, 1-methallyl, 1-dimethylallyl, 2-methallyl, 1-phenylallyl, 2-phenylallyl, 3-diphenylallyl, 1, 2-dimethylallyl, 1-phenyl-1-butenyl and 3-phenyl-1-butenyl. In addition, alkenyl groups may be optionally substituted.

Alkynyl-as used herein, covers both straight and branched chain alkynyl groups. Preferred alkynyl groups are those containing 2 to 15 carbon atoms. In addition, alkynyl groups may be optionally substituted.

Aryl or aromatic-as used herein, non-fused and fused systems are contemplated. Preferred aryl groups are those containing from 6 to 60 carbon atoms, more preferably from 6 to 20 carbon atoms, and even more preferably from 6 to 12 carbon atoms. Examples of aryl groups include phenyl, biphenyl, terphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chicory, perylene and azulene, preferably phenyl, biphenyl, terphenyl, triphenylene, fluorene and naphthalene. In addition, aryl groups may be optionally substituted. Examples of non-condensed aryl groups include phenyl, biphenyl-2-yl, biphenyl-3-yl, biphenyl-4-yl, p-terphenyl-3-yl, p-triphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, o-tolyl, m-tolyl, p- (2-phenylpropyl) phenyl, 4 '-methylbiphenyl-4' -tert-butyl-p-terphenyl-4-yl, o-cumyl, m-cumyl, p-cumyl, 2, 3-xylyl, 3, 4-xylyl, 2, 5-xylyl, mesityl and m-tetrabiphenyl.

Heterocyclyl or heterocycle-as used herein, aromatic and non-aromatic cyclic groups are contemplated. Heteroaryl also refers to heteroaryl. Preferred non-aromatic heterocyclic groups are those containing 3 to 7 ring atoms, which include at least one heteroatom such as nitrogen, oxygen and sulfur. The heterocyclic group may also be an aromatic heterocyclic group having at least one hetero atom selected from the group consisting of a nitrogen atom, an oxygen atom, a sulfur atom and a selenium atom.

Heteroaryl-as used herein, non-fused and fused heteroaromatic groups are contemplated that may contain 1 to 5 heteroatoms. Preferred heteroaryl groups are those containing 3 to 30 carbon atoms, more preferably 3 to 20 carbon atoms, and even more preferably 3 to 12 carbon atoms. Suitable heteroaryl groups include dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridine indole, pyrrolopyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indenazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, benzothiophene pyridine, thienodipyridine, benzothiophene bipyridine, benzoselenophene, dibenzofuran, dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine, triazine, benzimidazole, 1, 2-aza-1, 3-aza-borane, 1-borane, 4-borane, and the like. In addition, heteroaryl groups may be optionally substituted.

Alkoxy-is represented by-O-alkyl. Examples of alkyl groups and preferred examples are the same as described above. Examples of the alkoxy group having 1 to 20 carbon atoms, preferably 1 to 6 carbon atoms include methoxy, ethoxy, propoxy, butoxy, pentoxy and hexoxy groups. The alkoxy group having 3 or more carbon atoms may be linear, cyclic or branched.

Aryloxy-is represented by-O-aryl or-O-heteroaryl. Examples and preferred examples of aryl and heteroaryl groups are the same as described above. Examples of the aryloxy group having 6 to 40 carbon atoms include phenoxy and diphenoxy.

Aralkyl-as used herein, an alkyl group having an aryl substituent. In addition, aralkyl groups may be optionally substituted. Examples of aralkyl groups include benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl, 2-phenylisopropyl, phenyl tert-butyl, α -naphthylmethyl, 1- α -naphthyl-ethyl, 2- α -naphthylethyl, 1- α -naphthylisopropyl, 2- α -naphthylisopropyl, β -naphthylmethyl, 1- β -naphthyl-ethyl, 2- β -naphthyl-ethyl, 1- β -naphthylisopropyl, 2- β -naphthylisopropyl, p-methylbenzyl, m-methylbenzyl, o-methylbenzyl, p-chlorobenzyl, m-chlorobenzyl, o-chlorobenzyl, p-bromobenzyl, m-bromobenzyl, o-bromobenzyl, p-iodobenzyl, m-iodobenzyl, o-iodobenzyl, p-hydroxybenzyl, m-hydroxybenzyl, o-aminobenzyl, m-aminobenzyl, o-aminobenzyl, p-nitrobenzyl, m-nitrobenzyl, o-nitrobenzyl, p-cyanobenzyl, m-cyanobenzyl, o-cyanobenzyl, 1-chlorophenyl, 1-isopropyl and 1-isopropyl. Among the above, preferred are benzyl, p-cyanobenzyl, m-cyanobenzyl, o-cyanobenzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl and 2-phenylisopropyl.

The term "aza" in aza-dibenzofurans, aza-dibenzothiophenes and the like means that one or more C-H groups in the corresponding aromatic fragment are replaced by nitrogen atoms. For example, azatriphenylenes include dibenzo [ f, h ] quinoxalines, dibenzo [ f, h ] quinolines, and other analogs having two or more nitrogens in the ring system. Other nitrogen analogs of the above-described aza derivatives will be readily apparent to those of ordinary skill in the art, and all such analogs are intended to be included in the terms described herein.

Alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, heterocyclyl, aryl, and heteroaryl groups may be unsubstituted or substituted with one or more groups selected from deuterium, halogen, alkyl, cycloalkyl, aralkyl, alkoxy, aryloxy, amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphine, and combinations thereof.

It will be appreciated that when a fragment of a molecule is described as a substituent or otherwise attached to another moiety, its name may be written according to whether it is a fragment (e.g., phenyl, phenylene, naphthyl, dibenzofuranyl) or according to whether it is an entire molecule (e.g., benzene, naphthalene, dibenzofuran). As used herein, these different ways of specifying substituents or linking fragments are considered equivalent.

In the compounds mentioned in this disclosure, the hydrogen atoms may be partially or completely replaced by deuterium. Other atoms such as carbon and nitrogen may also be replaced by their other stable isotopes. Substitution of other stable isotopes in the compounds may be preferred because of their enhanced efficiency and stability of the device.

In the compounds mentioned in this disclosure, poly (heavy) substitution refers to a range of substitution inclusive of di (heavy) substitution up to the maximum available substitution.

In the compounds mentioned in this disclosure, the expression that adjacent substituents can optionally be linked to form a ring is intended to be taken to mean that two groups are linked to each other by a chemical bond. This is illustrated by the following example:

furthermore, the expression that adjacent substituents can optionally be linked to form a ring is also intended to be taken to mean that in the case where one of the two groups represents hydrogen, the second group is bonded at the position to which the hydrogen atom is bonded, thereby forming a ring. This is illustrated by the following example:

wherein the method comprises the steps of

X ₁ To X ₄ Any two of which are nitrogen and the remaining two are each independently selected from C or CR;

X ₅ to X ₈ ,Y ₁ To Y ₈ ,Z ₁ To Z ₁₂ Each independently selected from N, C or CR;

a is selected from CR ' R ', NR ', O, S or Se;

R, R ', R ", R'" are each independently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted arylalkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl (alkylsilyl group) having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfonyl, phosphonyl, and combinations thereof;

two adjacent substituents can optionally be joined to form a ring; and when A is CR 'R' or NR 'and, R', R 'and R' are neither from Z ₁ To Z ₁₂ Form a ring.

According to another embodiment of the invention, the compound is a compound having formula 2:

according to another embodiment of the invention, wherein X ₂ And X ₄ Is N, X ₁ ，X ₃ And X ₅ To X ₈ Are each selected from CR or C.

According to another embodiment of the invention, wherein Z ₁ To Z ₁₂ At least one of which is N, and/or Y ₁ To Y ₈ At least one of which is N.

According to another embodiment of the invention, wherein Z ₁ To Z ₁₂ Are all selected from CR or C, and/or Y ₁ To Y ₈ Are each selected from C or CR.

According to another embodiment of the invention, wherein a is NR' ".

According to another embodiment of the invention, wherein R, R ', R ", R'" are each independently selected from the group consisting of phenyl, biphenyl, triphenylsilylphenyl, naphthyl, dibenzothienyl, fluorenyl, azaphenyl, azanaphthyl, azabiphenyl, halophenyl, cyano-substituted phenyl, and halogen.

According to another embodiment of the invention, wherein the compound is selected from the group consisting of compound 1 to compound 420, wherein compound 1 to compound 420 are referred to in claim 8.

According to still another embodiment of the present invention, there is also disclosed an electroluminescent device including:

An anode is provided with a cathode,

a cathode electrode, which is arranged on the surface of the cathode,

wherein the method comprises the steps of

X ₅ to X ₈ ,Y ₁ To Y ₈ ,Z ₁ To Z ₁₂ Each independently selectFrom N, C or CR;

a is selected from CR ' R ', NR ', O, S or Se;

According to one embodiment of the invention, wherein the organic layer is a light emitting layer and the compound is a host material.

According to one embodiment of the invention, the organic layer further comprises a phosphorescent light emitting material.

According to one embodiment of the invention, the phosphorescent light-emitting material is a metal complex.

According to one embodiment of the invention, wherein the phosphorescent light-emitting material is a metal complex comprising at least one ligand comprising any one of the following structures:

wherein R is _a ,R _b And R is _c May represent mono-, di-, tri-or tetra-substitution, or no substitution;

X _b selected from the group consisting of: o, S, se, NR _N1 ,CR _C1 R _C2 ；

Ra,R _b ,R _c ,R _N1 ,R _C1 And R is _C2 Each independently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted aralkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted amine having 0 to 20 carbon atoms, acyl, carbonyl, carboxylic acid groups, ester groups, nitrile, isonitrile, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof;

Two adjacent substituents can optionally be linked to form a ring.

According to one embodiment of the invention, the organic layer is an electron transport layer and the compound is an electron transport material.

According to still another embodiment of the present invention, there is also disclosed a compound formulation comprising a compound having a structure represented by formula 1, the specific structure of which is detailed in the above-described embodiment.

Combined with other materials

The materials described herein for specific layers in an organic light emitting device may be used in combination with various other materials present in the device. Combinations of these materials are described in detail in U.S. patent application 2016/0359122A1, paragraphs 0132-0161, the entire contents of which are incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that may be used in combination with the compounds disclosed herein, and one skilled in the art can readily review the literature to identify other materials that may be used in combination.

Materials described herein as useful for specific layers in an organic light emitting device may be used in combination with a variety of other materials present in the device. For example, the luminescent dopants disclosed herein may be used in combination with a variety of hosts, transport layers, barrier layers, implant layers, electrodes, and other layers that may be present. Combinations of these materials are described in detail in the patent application US2015/0349273A1, paragraph 0080-0101, the entire contents of which are incorporated herein by reference. The materials described or mentioned therein are non-limiting examples of materials that may be used in combination with the compounds disclosed herein, and one skilled in the art can readily review the literature to identify other materials that may be used in combination.

In the examples of material synthesis, all reactions were carried out under nitrogen protection, unless otherwise indicated. All reaction solvents were anhydrous and used as received from commercial sources. The synthetic products were subjected to structural confirmation and characterization testing using one or more equipment conventional in the art (including, but not limited to, bruker's nuclear magnetic resonance apparatus, shimadzu's liquid chromatograph, liquid chromatograph-mass spectrometer, gas chromatograph-mass spectrometer, differential scanning calorimeter, shanghai's optical technique fluorescence spectrophotometer, wuhan Koste's electrochemical workstation, anhui Bei Yi g sublimator, etc.), in a manner well known to those skilled in the art. In an embodiment of the device, the device characteristics are also tested using equipment conventional in the art (including, but not limited to, a vapor deposition machine manufactured by Angstrom Engineering, an optical test system manufactured by Frieda, st. John's, an ellipsometer manufactured by Beijing, etc.), in a manner well known to those skilled in the art. Since those skilled in the art are aware of the relevant contents of the device usage and the testing method, and can obtain the intrinsic data of the sample certainly and uninfluenced, the relevant contents are not further described in this patent.

Material synthesis examples:

the preparation method of the compound of the present invention is not limited, and the following compounds are typically taken as examples, but not limited to, the synthetic route and preparation method are as follows:

example 1: synthesis of Compound 3

Step 1: synthesis of intermediate B

4-bromocarbazole (20 g,81.3 mmol), iodobenzene (99.5 g,487.6 mmol), cuprous chloride (4.0 g,40.6 mmol), potassium carbonate (168.5 g,1218.9 mmol), 18-crown-6 (10.7 g,40.6 mmol), 1, 10-phenanthroline (7.3 g,40.6 mmol) and N-methylpyrrolidone (508 mL) were added to a three-necked flask under nitrogen atmosphere and reacted overnight at 180 ℃. Cooled to room temperature, distilled water was then added, the mixture was extracted with methylene chloride, the organic phase was washed with water, dried over anhydrous sodium sulfate and concentrated to remove the solvent, and the residue was purified by column chromatography (pure petroleum ether) to give 116g (yield: 89%) of intermediate B as a beige oil.

Step 2: synthesis of intermediate C

Intermediate B (10 g,31 mmol), pinacol biborate (11.8 g,46.6 mmol), [1,1' -bis (diphenylphosphino) ferrocene ] palladium dichloride (1.1 g,31.6 mmol), potassium acetate (9.1 g,93.2 mmol) and N, N-dimethylformamide (77.0 mL) were added to a three-necked flask under nitrogen protection and reacted at 90℃for 48h. Cooling to room temperature followed by addition of distilled water, extraction of the mixture with dichloromethane, washing of the organic phase with water, drying of the organic phase over anhydrous sodium sulfate and concentration of the solvent, purification of the residue by column chromatography (PE/ea=50:1 to PE/ea=10:1) afforded intermediate C10 g as a white solid (yield: 87%).

Step 3: synthesis of intermediate D

Intermediate C (10.0 g,27.1 mmol), 2-bromonitrobenzene (6.6 g,32.5 mmol), tetrakis triphenylphosphine palladium (3.1 g,2.7 mmol), potassium carbonate (9.4 g,67.7 mmol) and solvent (THF: 56mL, H) were reacted under nitrogen ₂ O:11 mL) was added to a three-necked flask and reacted at 70 c overnight. Cooled to room temperature, then distilled water was added, the mixture was extracted with ethyl acetate, the organic phase was washed with water, dried over anhydrous magnesium sulfate and concentrated to remove the solvent, and the residue was purified by column chromatography (PE/ea=20:1 to PE/ea=1:1) to give intermediate D5.9 g (yield: 60%) as a yellow solid.

Step 4: synthesis of intermediate E

Intermediate D (10.0 g,27.4 mmol) and triphenylphosphine (18.0 g,32.5 mmol) were dissolved in 40mL 1, 2-dichlorobenzene and reacted overnight under nitrogen with heating to 180 ℃. Cooled to room temperature, and the reaction was purified directly by column chromatography (PE/dcm=10:1 to PE/dcm=1:1) to give intermediate E7.0 g (yield: 77%) as a white solid.

Step 5: synthesis of intermediate F

2-bromocarbazole (10 g,40.6 mmol) was dissolved in 250 ml of N, N-dimethylformamide, naH (3.2 g,81.2mmol, 60%) was added under ice-bath, followed by 2-chloro-4-phenylquinazoline (10.7 g,44.66 mmol) and then allowed to react overnight at room temperature, distilled water was added after the reaction was completed, and a solid was precipitated, which was washed with ethanol to give intermediate F15.2 g as a white solid (yield: 83%).

Step 6: synthesis of Compound 3

5-phenyl-5, 8-indolino [2,3-c ] carbazole (5.0 g,15.0 mmol), intermediate F (10.16 g,22.6 mmol), tris (dibenzylideneacetone) dipalladium (1.37 g,1.5 mmol), 2-dicyclohexylphosphine-2 ',6' -dimethoxybiphenyl (1.2 g,3.0 mmol), sodium t-butoxide (5.67 g,60 mmol) and xylene (250 mL) were added to a three-necked flask under nitrogen atmosphere and reacted at 160℃for 24h. Cooled to room temperature, then distilled water was added, the mixture was extracted with dichloromethane, the organic phase was washed with water, dried over anhydrous magnesium sulfate and concentrated to remove the solvent, and the residue was purified by column chromatography (PE/ea=10:1) in toluene to obtain 7.5g (yield: 71%) of compound as a yellow solid. The product was identified as the target product, molecular weight 702.

Example 2: synthesis of Compound 2

5-phenyl-5, 8-indolino [2,3-c ] carbazole (1G, 3.0 mmol), intermediate G (2.0G, 4.5 mmol), tris (dibenzylideneacetone) dipalladium (137 mg,0.15 mmol), 2-dicyclohexylphosphine-2 ',6' -dimethoxybiphenyl (61.5 mg,0.15 mmol), sodium t-butoxide (1.2G, 12 mmol) and xylene (10 mL) were added to a three-necked flask and reacted at 160℃for 24h under nitrogen protection. Cooled to room temperature, then distilled water was added, the mixture was extracted with dichloromethane, the organic phase was washed with water, dried over anhydrous magnesium sulfate and concentrated to remove the solvent, and the residue was purified by column chromatography (PE/ea=50:1 to 10:1) to give 2.2 g (yield: 57%) of a yellow solid compound. The product was identified as the target product, molecular weight 702.

Example 3: synthesis of Compound 160:

step 1, synthesizing intermediate H

O-bromoaniline (10 g,58.14 mmol), 2, 6-dichloropyridine (8.6 g,58.14 mmol) tris (dibenzylideneacetone) dipalladium (2.66 g,2.9 mmol), 4, 5-bis-diphenylphosphine-9, 9-dimethylxanthene (3.36 g,5.8 mmol) and sodium tert-butoxide (11.16 g,116.28 mmol) were added to a three-necked flask under nitrogen protection, followed by 1, 4-dioxane (300 mL) at 110℃for 4H, after the reaction was completed the solvent was removed, the solid was filtered with dichloromethane, the filtrate was dried, and the residue was purified by column chromatography (PE/EA=100:1) to give intermediate H10.0 g (yield: 59%).

Step 2: synthesis of intermediate I

Intermediate H (10.0 g,35.2 mmol), tetrakis triphenylphosphine palladium (4.07 g,3.52 mmol), potassium acetate (6.9 g,70.4 mmol) and solvent (DMF, 200 mL) were added under nitrogen and reacted at 150℃for 24H. Cooled to room temperature, then distilled water was added, the mixture was extracted with ethyl acetate, the organic phase was washed with water, dried over anhydrous magnesium sulfate and concentrated to remove the solvent, and the residue was purified by column chromatography (PE/ea=50:1 to PE/ea=5:1) to give 3.0g (yield: 21%) of intermediate I as a white solid.

Step 3: synthetic intermediate J

Intermediate I (1 g,4.95 mmol), 2-chloro-4-phenylquinazoline (1.8 g,7.43 mmol), copper powder (1.19 g,4.95 mmol), potassium carbonate (2.05 g,14.85 mmol), 18-crown-6 (1.31 g,4.95 mmol) and xylene (50 mL) were added to a three-necked flask under nitrogen and reacted overnight at 160 ℃. Cooled to room temperature, then distilled water was added, the mixture was extracted with dichloromethane, the organic phase was washed with water, dried over anhydrous sodium sulfate and concentrated to remove the solvent, and the residue was purified by column chromatography (PE/ea=50:1) to give intermediate J1.6 g (yield: 80%) as a white solid.

Step 4: synthesis of Compound 160

5-phenyl-5, 8-indolino [2,3-c ] carbazole (3.28 g,9.86 mmol), intermediate J (4.0 g,9.86 mmol), tris (dibenzylideneacetone) dipalladium (905.85 mg,0.99 mmol), 2-dicyclohexylphosphine-2 ',6' -dimethoxybiphenyl (811.8 mg,1.98 mmol), sodium t-butoxide (3.79 g,39.44 mmol) and xylene (200 mL) were added to a three-necked flask under nitrogen atmosphere and reacted overnight at 80 ℃. Cooled to room temperature, then distilled water was added, the mixture was extracted with dichloromethane, the organic phase was washed with water, dried over anhydrous magnesium sulfate and concentrated to remove the solvent, and the residue was purified by column chromatography (PE/ea=50:1 to PE/ea=10:1) in toluene to obtain 160.1 g (yield: 60%) of a yellow solid compound. The product was identified as the target product, molecular weight 703.

Those skilled in the art will recognize that the above preparation method is only an illustrative example, and that those skilled in the art can modify it to obtain other compound structures of the present invention.

Device embodiment

First, a glass substrate having an 80nm thick Indium Tin Oxide (ITO) anode was cleaned, and then treated with oxygen plasma and UV ozone. After the treatment, the substrate was baked in a glove box to remove moisture. The substrate is then mounted on a substrate support and loaded into a vacuum chamber. The organic layer specified below was at a vacuum level of about 10 ^-8 The deposition was performed sequentially on the ITO anode by thermal vacuum deposition at a rate of 0.2 to 2 a/s in the case of a tray. The compound HI is used as a Hole Injection Layer (HIL). The compound HT serves as a Hole Transport Layer (HTL). Compound EB acts as an Electron Blocking Layer (EBL). Then, the compound R1 or the compound R2 is doped in the compound of the present invention to serve as an emission layer (EML). Compound HB was used as a Hole Blocking Layer (HBL). On the hole blocking layer, the compound ET and 8-hydroxyquinoline-lithium (Liq) were co-evaporated as an Electron Transport Layer (ETL). Finally, 8-hydroxyquinoline-lithium (Liq) with a thickness of 1nm was evaporated as an electron injection layer, and 120nm of aluminum was evaporated as a cathode. The device was then transferred back to the glove box and encapsulated with a glass cover and a moisture absorbent to complete the device.

Device comparative example

According to the device embodiment described above, only the light emitting layer (EML) is changed: compound R1 or compound R2 is doped in compound a as an emission layer (EML).

The detailed device layer structure and thickness are shown in the following table. Wherein more than one layer of the material used is doped with different compounds in the weight proportions described.

Table 1 device structure of device embodiments

The material structure used in the device is as follows:

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IVL and lifetime characteristics of the device were measured at different current densities and voltages. Tables 2 and 3 show the values at 1000cd/m ² Measured λmax, voltage (Voltage) and CIE data, device lifetime LT 95 at 15mA/cm ² Measured at constant current.

Table 2 device data

Device ID	CIE(x,y)	λmax(nm)	Voltage(V)	LT 95(hrs)
					Example 1	0.683,0.317	625	2.99	434.1
Example 2	0.683,0.317	624	2.83	1038.7
					Comparative example 1	0.683,0.315	624	3.41	50

Table 3 device data

Device ID	CIE(x,y)	λmax(nm)	Voltage(V)	LT 95(hrs)
					Implementation of the embodimentsExample 3	0.669,0.330	623	2.85	1475.4
Example 4	0.670,0.330	624	2.81	205.8
					Comparative example 2	0.662,0.336	619	3.88	157.1

Discussion:

as shown in the data in table 2, CIE, amax is similar. Example 1 and example 2 have very long device life and relatively low driving voltages compared to comparative example 1 using compounds 2, 3 as host materials for example 1 and example 2, respectively. It shows that the compound of formula 1 can make the device have very low driving voltage and very long service life, greatly improving the performance of the device.

Similarly, as shown by the data in table 3, examples 3 and 4 showed very little change in CIE λmax compared to comparative example 2. The use of compounds 3, 160 as host materials for example 3 and example 4, respectively, has lower drive voltages and excellent device lifetime. It shows that the compound of formula 1 can make the device have lower driving voltage and excellent life, has greatly improved the performance of device.

It should be understood that the various embodiments described herein are by way of example only and are not intended to limit the scope of the invention. Thus, as will be apparent to those skilled in the art, the claimed invention may include variations of the specific and preferred embodiments described herein. Many of the materials and structures described herein may be substituted with other materials and structures without departing from the spirit of the invention. It is to be understood that the various theories as to why the present invention works are not intended to be limiting.

Claims

1. A compound having formula 2:

wherein the method comprises the steps of

X ₂ And X ₄ Selected from N, X ₃ Selected from C, X ₁ 、X ₅ To X ₈ Each independently selected from CR;

Y ₁ selected from N, C or CR; y is Y ₂ To Y ₄ Each independently selected from C or CR; y is Y ₅ To Y ₈ Each independently selected from CR;

Z ₁ 、Z ₂ 、Z ₅ To Z ₁₂ Each independently selected from CR; z is Z ₃ Selected from C and bonded to A and Z ₄ Selected from C and Z ₁₂ Adjacent C bonds;

a is selected from NR';

r, R' "are each independently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, and combinations thereof;

wherein the substituted alkyl, substituted aryl refers to an alkyl, any one of which may be substituted with one or more groups selected from deuterium, halogen, unsubstituted alkyl groups having 1-20 carbon atoms, unsubstituted aryl groups having 6-30 carbon atoms, and combinations thereof;

wherein the compound is not a group consisting of:

2. the compound according to claim 1, wherein Z ₁ 、Z ₂ 、Z ₅ To Z ₁₂ Each independently selected from CR, and/or Y ₁ To Y ₄ Each independently selected from C or CR.

3. The compound of claim 1 or 2, wherein R, R' "are each independently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted aryl groups having from 6 to 20 carbon atoms, and combinations thereof.

4. The compound of claim 1 or 2, wherein R, R' "are each independently selected from the group consisting of phenyl, biphenyl, naphthyl, fluorenyl, halophenyl, and halogen.

5. The compound of claim 1, wherein the compound is selected from the group consisting of:

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6. an electroluminescent device, comprising:

an anode is provided with a cathode,

a cathode electrode, which is arranged on the surface of the cathode,

and an organic layer disposed between the anode and the cathode, the organic layer comprising the compound of any one of claims 1-5.

7. The electroluminescent device according to claim 6, wherein the organic layer is a light-emitting layer and the compound is a host material.

8. The electroluminescent device of claim 6 wherein the organic layer further comprises a phosphorescent light emitting material.

9. The electroluminescent device of claim 8 wherein the phosphorescent light emitting material is a metal complex.

10. The electroluminescent device of claim 9, wherein the metal complex comprises at least one ligand comprising any one of the following structures:

X _b selected from the group consisting of: o, S, se, NR _N1 ,CR _C1 R _C2 ；

Ra,R _b ,R _c ,R _N1 ,R _C1 And R is _C2 Each independently selected from the group consisting of: hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1-20 carbon atoms, substituted or unsubstitutedSubstituted cycloalkyl having 3 to 20 ring carbon atoms, substituted or unsubstituted heteroalkyl having 1 to 20 carbon atoms, substituted or unsubstituted arylalkyl having 7 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted aryloxy having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 20 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, substituted or unsubstituted alkylsilyl having 3 to 20 carbon atoms, substituted or unsubstituted arylsilyl having 6 to 20 carbon atoms, substituted or unsubstituted amino having 0 to 20 carbon atoms, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, thio, sulfinyl, sulfonyl, phosphino, and combinations thereof;

Adjacent substituents can optionally be joined to form a ring.

11. The electroluminescent device of claim 6, the organic layer being an electron transport layer and the compound being an electron transport material.

12. A compound formulation comprising a compound of any one of claims 1-5.