CN114315877A

CN114315877A - Organic compound, application thereof, and organic electroluminescent device comprising same

Info

Publication number: CN114315877A
Application number: CN202011075192.4A
Authority: CN
Inventors: 李熠烺; 李国孟; 曾礼昌; 曲忠国
Original assignee: Beijing Eternal Material Technology Co Ltd
Current assignee: Beijing Eternal Material Technology Co Ltd
Priority date: 2020-10-09
Filing date: 2020-10-09
Publication date: 2022-04-12

Abstract

An organic compound having a structure represented by formula (1):

wherein, X¹Selected from the group consisting of CR¹R²、NR³O, S or SiR⁴R⁵And when R is one of³When present, R³Optionally linked to ring D to form a fused ring structure; ring E, ring D and ring A are each independently selected from the group consisting of substituted or unsubstituted C6-C30 aromatic rings, substituted or unsubstituted C3-C30 aromatic ringsOne of the heterocycles; ar is a structure represented by formula (a); z¹Selected from C or Si; z²Selected from the group consisting of CR⁶R⁷、NR⁸、O、S、SiR⁹R¹⁰A is 0 or 1; y is¹～Y⁴Each independently selected from C, CR¹³Or N, Y⁵～Y⁸Each independently selected from CR¹³Or N; r¹～R¹³Each independently selected from one of hydrogen, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted C3-C30 heteroaryl, R¹³Optionally, each independently is linked to the attached aromatic or heteroaromatic ring to form a ring.

Description

Organic compound, application thereof, and organic electroluminescent device comprising same

Technical Field

The invention relates to the technical field of organic light-emitting materials, in particular to an organic compound, application thereof and an organic electroluminescent device containing the organic compound.

Background

In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them well suited for fabrication on flexible substrates, allowing for the design and production of aesthetically pleasing and crunchy optoelectronic products, with unparalleled advantages over inorganic materials. Examples of such organic optoelectronic devices include Organic Light Emitting Diodes (OLEDs), organic field effect transistors, organic photovoltaic cells, organic sensors, and the like. Among them, OLEDs have been developed particularly rapidly, and have been commercially successful in the field of information display. The OLED can provide three colors of red, green and blue with high saturation, and a full-color display device manufactured by using the OLED does not need an additional backlight source and has the advantages of colorful, light, thin and soft color and the like.

The core of the OLED device is a thin film structure containing various organic functional materials. Common functionalized organic materials are: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, and light emitting host materials and light emitting objects (dyes), and the like. When electricity is applied, electrons and holes are injected, transported to the light emitting region, and recombined therein, respectively, thereby generating excitons and emitting light.

People have developed various organic materials, and the organic materials are combined with various peculiar device structures, so that the carrier mobility can be improved, the carrier balance can be regulated, the electroluminescent efficiency can be broken through, and the attenuation of the device can be delayed. For quantum mechanical reasons, common fluorescent luminophores mainly utilize singlet excitons generated when electrons and air are combined to emit light, and are still widely applied to various OLED products. Some metal complexes, such as iridium complexes, can emit light using both triplet excitons and singlet excitons, which are called phosphorescent emitters, and the energy conversion efficiency can be increased by up to four times as compared with conventional fluorescent emitters. The thermal excitation delayed fluorescence (TADF) technology can still effectively utilize triplet excitons to achieve higher luminous efficiency without using a metal complex by promoting the conversion of triplet excitons to singlet excitons. Thermal excitation sensitized fluorescence (TASF) technology also achieves higher luminous efficiency by sensitizing the emitter by energy transfer using TADF-like materials.

As OLED products gradually enter the market, there are increasingly higher requirements on the performance of such products. The currently used OLED materials and device structures cannot completely solve the problems of OLED product efficiency, service life, cost and the like. The present inventors have discovered a clever molecular design through careful consideration and ongoing experimentation, and are described in detail below. Surprisingly, the compounds disclosed in the present invention are very suitable for application in OLEDs and improve the performance of the devices.

Disclosure of Invention

Problems to be solved by the invention

As OLED products gradually enter the market, there are increasingly higher demands on the performance of such products. The currently used OLED materials and device structures cannot completely solve the problems of OLED product efficiency, service life, cost and the like.

In view of the above problems of the prior art, the present invention provides a new class of compounds for organic electroluminescent devices to meet the increasing demand for the photoelectric properties and the service life of OLED devices.

Means for solving the problems

The researchers of the invention propose a smart molecular design scheme through careful thinking and continuous experiments. Surprisingly, the compound obtained by the scheme is very suitable for being applied to an OLED, and the obtained device has excellent performance and can meet the requirements of people.

Specifically, one of the objects of the present invention is to provide an organic compound having a structure represented by the following formula (1):

wherein,

X¹independently selected from CR¹R²、NR³O, S or SiR⁴R⁵And when R is one of³When present, R³Optionally linked to ring D to form a fused ring structure;

ring E, ring D and ring A are each independently selected from one of substituted or unsubstituted C5-C30 aromatic rings, substituted or unsubstituted C3-C30 aromatic heterocycles;

ar is a structure shown in a formula (a), and is connected with N in the formula (1) at the position of a star;

Z¹selected from C or Si;

Z²selected from the group consisting of CR⁶R⁷、NR⁸、O、S、SiR⁹R¹⁰A is 0 or 1;

R¹～R¹²each independently selected from one of hydrogen, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted C3-C30 heteroaryl;

Y¹～Y⁴each independently selected from C, CR¹³Or the number of N is greater than the number of N,

Y⁵～Y⁸each independently selected from CR¹³Or N;

R¹³independently selected from hydrogen, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, halogen, cyano, nitro, hydroxyl,Amino, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroaryl amino, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl, wherein R is one of R¹³Optionally, each independently connects with the connected aromatic ring or aromatic heterocyclic ring to form a ring;

when the substituted or unsubstituted ring or group has a substituent, the substituent is selected from one or a combination of at least two of halogen, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 silyl, cyano, nitro, hydroxyl, amino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl and C3-C30 heteroaryl.

When a is 0, it represents Z²In the absence of, in formula (a) and Z²The two atoms to which they are attached are directly connected by a single bond.

The specific reason why the above-mentioned compound of the present invention is excellent as a light-emitting material is not clear, and is presumed as follows: the compound satisfying the structure of the general formula (1) defined in the present invention has a suitable rigid conjugated structure as a parent nucleus, and a specific Ar group is directly attached to N, and thus can exhibit high external quantum efficiency and low lighting voltage in an OLED device. When a compound obtained by directly linking a specific parent nucleus with a specific Ar group is used as a light-emitting layer material, the voltage of a device can be improved and the light-emitting efficiency can be improved.

The inventors have found that the above-mentioned compounds of the present invention have the above-mentioned excellent properties closely related to the above-mentioned structure, and specifically, in the structure of the general formula (1), N and Ar groups of the mother nucleus must be directly linked and linked to the aromatic ring or the aromatic heterocyclic ring of the formula (a). If the Ar group is not directly bonded to the N of the core, the molecule is not sufficiently rigid and its efficiency when used in a device is reduced, if other groups are present between them, or if the core is bonded to Z of formula (a)¹Or Z²In the above case, the rigidity is lowered, and the red shift of light color is liable to occur, and the obtained compound is inferior in performance to the above-mentioned compound of the present invention.

The organic compound of the present invention is preferablyX¹Is NR³，R³Optionally linked to ring D to form a fused ring structure;

more preferably R³Is substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl;

further preferred is R³Is one of the following substituted or unsubstituted groups: phenyl, naphthyl, anthracenyl, biphenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, furyl, benzofuryl, dibenzofuryl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, acridinyl, carbazolyl.

The organic compound of the present invention is preferably one in which ring E, ring D and ring A are each independently selected from a substituted or unsubstituted C6-C14 aromatic ring, a substituted or unsubstituted C3-C14 aromatic heterocycle.

The organic compound of the present invention preferably has a structure in which ring E and ring D each independently have the formula (b):

wherein represents a six-membered ring thereof with B and N in formula (1) or B and X¹At the site of fusion of the six-membered ring, Z^1’～Z^4’Each independently selected from CR¹⁴And N; the R is¹⁴Each independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 silyl, amino, C6-C30 arylamino, C3-C30 heteroaryl amino, C6-C30 aryl and C3-C30 heteroaryl, wherein R is selected from one of C3-C10 heteroaryl¹⁴Optionally fused to form a ring with the aromatic ring or heterocyclic ring to which it is attached.

For convenience of description, preferred structures of rings E and D are described as combinations of formula (b) above with other parts of the molecule. Those skilled in the art will appreciate that in fact, as shown in formula (1), the complete rings E and D also contain 2 carbon atoms in common with the rest of the molecule. The following description is also similar to the preferred structure of ring A.

The organic compound of the present invention preferably has a structure represented by the formula (b'):

wherein one represents the site at which ring A is attached to the six-membered ring of formula (1) in which B and N are located, and the other represents ring A and B and X¹At the site of attachment of the six-membered ring, Z^5’～Z^7’Each independently selected from CR¹⁴And N; the R is¹⁴Independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, chain alkyl of C1-C10, cycloalkyl of C3-C10, alkoxy of C1-C10, amino, arylamino of C6-C30, heteroarylamino of C3-C30, aryl of C6-C30 and heteroaryl of C3-C30, wherein R is¹⁴Optionally fused to form a ring with the aromatic ring or heterocyclic ring to which it is attached.

By adopting the organic compound of the present invention with the above structure, higher external quantum efficiency and lower voltage can be exhibited in an OLED device.

R³When not linked to the ring D to form a condensed ring structure, the organic compound of the present invention may be represented by the formula (1-1) or (1-3); r³When the organic compound of the present invention is bonded to ring D to form a condensed ring structure, it can be represented by the formula (1-2) or (1-4). These examples are given for convenience of understanding, and the scope of the organic compound of the present invention is not limited thereto.

In the above (1-1) to (1-4), Z^1’～Z^7’、Z^1”～Z^4”Each independently selected from CR¹⁴One of N, R¹⁴See above for ranges of (d).

By adopting the above structure, the organic compound of the present invention can have a higher carrier transport performance.

The organic compound of the present invention is preferably Z¹Is C, a ═ 0, or Z¹Is C, a is 1, Z²Selected from the group consisting of CR⁶R⁷、NR⁸O, in other words, formula (a) of the organic compound of the present invention is preferably selected from one of the following structural formulae:

the organic compound of the present invention is preferably R¹¹And R¹²Each independently being methyl or phenyl.

The formula (a) of the organic compounds of the invention is further preferably selected from one of the following structural formulae:

The organic compound of the present invention is preferably Y¹～Y⁴In the total number of N, Y is 0-1⁵～Y⁸0-1N in the total; more preferably Y¹～Y⁴Each independently selected from C, CR¹³，Y⁵～Y⁸Each independently selected from CR¹³Further, R is preferable¹³Is hydrogen. Here, Y¹～Y⁴Of the two groups, the one linked to the mother nucleus N is C, and the remaining 3 are CR¹³。

The organic compound of the present invention preferably has substituents on ring E, ring D and ring a, each of which is independently one selected from substituted or unsubstituted C1 to C10 chain alkyl groups, substituted or unsubstituted C3 to C10 cycloalkyl groups;

more preferably, the substituents are each independently selected from one of the following groups:

it is further preferred that each of the substituents is independently selected from one of the following groups:

the organic compound of the present invention preferably has the above-mentioned substituent at the para-position of B or N on the ring E and the ring D, and/or the substituent at the para-position of B on the ring A.

By adopting the above structure, the organic compound of the present invention can protect active sites, which is advantageous for improving the stability of the material.

In the present specification, the "substituted or unsubstituted" group may be substituted with one substituent or with a plurality of substituents, and when a plurality of substituents are present, they may be selected from different substituents or may be all or partially the same. When the same expression mode is involved in the invention, the same meanings are provided, and the selection ranges of the substituents are shown above and are not repeated.

In the present specification, the expression of Ca to Cb represents that the group has carbon atoms a to b, and the carbon atoms do not generally include the carbon atoms of the substituents unless otherwise specified.

In the present specification, the expression of a loop structure crossed by a line indicates an arbitrary position on the loop structure where a linking site can be bonded.

In the present specification, "independently" means that the subject may be the same or different when a plurality of subjects are provided.

In the present invention, unless otherwise specified, the expression of chemical elements generally includes the concept of isotopes thereofFor example, the expression "hydrogen (H)" includes isotopes thereof¹H (protium or H),²The concept of H (deuterium or D); carbon (C) then comprises¹²C、¹³C, etc., will not be described in detail.

In the present specification, unless otherwise specified, both aryl and heteroaryl groups include monocyclic and fused rings. The monocyclic aryl group means that at least one phenyl group is contained in the molecule, and when at least two phenyl groups are contained in the molecule, the phenyl groups are independent of each other and are linked by a single bond, and exemplified by phenyl, biphenylyl, terphenylyl, and the like. The fused ring aryl group means a group containing at least two aromatic rings in a molecule, and the aromatic rings are not independent of each other but are fused to each other with two adjacent carbon atoms in common. Monocyclic heteroaryl and fused ring heteroaryl are also similar.

In the present specification, the substituted or unsubstituted C6-C30 aryl group is preferably a C6-C20 aryl group, more preferably a group in the group consisting of phenyl, biphenyl, quaterphenyl, terphenyl, naphthyl, anthryl, benzanthryl, phenanthryl, benzophenanthryl, pyrenyl, anthryl, perylenyl, anthryl, fluoranthenyl, tetracenyl, pentacenyl, benzopyrenyl, terphenyl, fluorenyl, spirobifluorenyl, phenanthrenyl, hydropyryl, tetrahydropyrenyl, cis-or trans-indenofluorenyl, trimeric indenyl, isotridecylindenyl, spirotrimeric indenyl, spiroisotridecylindenyl. In particular, the biphenyl group is selected from 2-biphenyl, 3-biphenyl and 4-biphenyl; terphenyl includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl and m-terphenyl-2-yl; the naphthyl group includes a 1-naphthyl group or a 2-naphthyl group; the anthracene group is selected from 1-anthracene group, 2-anthracene group and 9-anthracene group; the fluorenyl group is selected from the group consisting of 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, and 9-fluorenyl; the pyrenyl group is selected from 1-pyrenyl, 2-pyrenyl and 4-pyrenyl; the tetracene group is selected from the group consisting of 1-tetracene, 2-tetracene, and 9-tetracene.

In this specification, the range of arylene groups is defined with reference to the corresponding aryl group except that one more hydrogen is removed than the corresponding aryl group; the range of aryl groups in arylamino groups can be referred to the corresponding aryl group.

In the present specification, a heteroatom generally refers to an atom or group of atoms selected from N, O, S, P, Si and Se, preferably N, O, S.

In the present specification, the substituted or unsubstituted heteroaryl group having C3 to C30 is preferably a C4 to C20 heteroaryl group, more preferably a nitrogen-containing heteroaryl group, an oxygen-containing heteroaryl group, a sulfur-containing heteroaryl group, and the like, and specific examples thereof include: furyl, thienyl, pyrrolyl, pyridyl, pyrazolyl, imidazolyl, pyrimidinyl, pyridazinyl, pyrazinyl, 1,2, 3-triazolyl, 1,2, 4-triazolyl, 1,2, 3-oxadiazolyl, 1,2, 4-oxadiazolyl, 1,2, 5-oxadiazolyl, 1,2, 3-thiadiazolyl, 1,2, 4-thiadiazolyl, 1,2, 5-thiadiazolyl, 1,3, 4-thiadiazolyl, 1,3, 5-triazinyl, 1,2, 4-triazinyl, 1,2, 3-triazinyl, tetrazolyl, 1,2,4, 5-tetrazinyl, 1,2,3, 4-tetrazinyl, 1,2,3, 5-tetrazinyl.

In the present specification, a fused ring heteroaryl group means a group which has at least one aromatic heterocyclic ring and one aromatic ring (aromatic heterocyclic ring or aromatic ring) in a molecule, and which is not independent of each other but shares two adjacent atoms fused to each other. The substituted or unsubstituted C6-C30 fused ring heteroaryl in the present invention is preferably C6-C20 fused ring heteroaryl, more preferably nitrogen-containing fused ring heteroaryl, oxygen-containing fused ring heteroaryl, sulfur-containing fused ring heteroaryl, etc., and specific examples thereof include: benzofuranyl, benzothienyl, isobenzofuranyl, isobenzothienyl, indolyl, isoindolyl, dibenzofuranyl, dibenzothienyl, carbazolyl and derivatives thereof, quinolinyl, isoquinolinyl, acridinyl, phenanthridinyl, benzo-5, 6-quinolinyl, benzo-6, 7-quinolinyl, benzo-7, 8-quinolinyl, phenothiazinyl, phenazinyl, indazolyl, benzimidazolyl, naphthoimidazolyl, phenanthrimidazolyl, pyridoimidazolyl, pyrazinimidazolyl, quinoxalimidazolyl, 1, 2-thiazolyl, 1, 3-thiazolyl, benzothiazolyl, benzopyrazinyl, benzopyrimidinyl, quinoxalinyl, 1, 5-diazoanthrenyl, 2, 7-diazepanyl, 2, 3-diazapyranyl, 1, 6-diazapyranyl, 1, 8-diazepanyl, 4,5,9, 10-tetraazaperyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbazinyl, phenanthrolinyl, benzotriazolyl, purinyl, pteridinyl, indolizinyl, benzothiadiazole, and the like, wherein the carbazolyl derivative is preferably 9-phenylcarbazole, 9-naphthylcarbazole benzocarbazole, dibenzocarbazole, or indolocarbazole.

In this specification, the range of heteroarylene groups is as long as they are referenced to the corresponding heteroaryl group, except that one more hydrogen is removed than the corresponding heteroaryl group; the range of heteroaryl groups in heteroarylamino groups can be referred to the corresponding heteroaryl group.

In the present specification, the C1-C10 chain alkyl group is preferably a C1-C6 chain alkyl group, and examples thereof include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, neopentyl, n-hexyl, neohexyl, n-heptyl, n-octyl, 2-ethylhexyl and the like.

In the present specification, the cycloalkyl group of C3-C10 includes monocycloalkyl and polycycloalkyl groups, preferably C4-C8 cycloalkyl groups, and may be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, cycloheptyl, cyclooctyl and the like.

In the present specification, the C1-C10 alkoxy group is preferably a C1-C8 alkoxy group, more preferably a C1-C6 alkoxy group, and examples thereof include: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentyloxy, isopentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy and the like, among which methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy, sec-butoxy, isobutoxy, isopentyloxy, more preferably methoxy.

In the present specification, the range of C1-C10 thioalkoxy groups is referred to the corresponding alkoxy group, with the only difference being that the oxygen in the alkoxy group is replaced by sulfur.

In the present specification, examples of the halogen include: fluorine, chlorine, bromine, iodine, etc., preferably fluorine.

Further, the compound of the general formula of the present invention is preferably the following specific compound, but the present invention is not limited to the specific compounds V1 to V303 shown below:

as another aspect of the present invention, there is also provided a use of the compound as described above in an organic electroluminescent device. In particular, it is preferable as a material for a light emitting layer in an organic electroluminescent device.

As still another aspect of the present invention, there is also provided an organic electroluminescent device comprising a first electrode, a second electrode and an organic layer interposed between the first electrode and the second electrode, characterized in that the organic layer contains therein a compound of the general formula (1) as described above.

Effects of the invention

The B-N organic material with the structure of the general formula (1) has a suitable rigid conjugated structure as a parent nucleus, and a specific Ar group is directly connected to N, so that the B-N organic material can show higher external quantum efficiency and lower lighting voltage in an OLED device. When the compound is used as a material of a light-emitting layer, the voltage of a device can be improved, and the light-emitting efficiency can be improved. The obtained device has excellent performance, can avoid the red shift of light color and improve the light color purity while improving the voltage and the efficiency of the device, and can meet the requirements of a deep blue OLED device.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Synthesis example 1:

synthesis of V9

Intermediate 1-1:

at room temperature, a 1000ml three-necked flask is added with the raw material A (20g, 83.36mmol), the raw material B (59.78g, 175.05mmol), Pd132(19.48g, 25.01mmol), sodium tert-butoxide (16.02g, 166.72mmol) and xylene (600ml) as a solvent, nitrogen is replaced for three times, the temperature is raised to 120 ℃ for reaction for 12h, heating is stopped, filtering and evaporation are carried out, and column chromatography purification is carried out (petroleum ether: dichloromethane is 10: 1), so as to obtain 51.0g of a product. Mass spectrometric analysis determined molecular mass: 804.6 (theoretical value: 804.4).

Material V9:

dissolving intermediate 1-1(51g, 63.35mmol) in 500ml xylene, slowly dropwise adding n-butyllithium (76.0ml, 190.05mmol) at-40 deg.C, recovering to room temperature, heating at 50 deg.C for 2 hr for activation, cooling to-40 deg.C, and sequentially and slowly adding BBr₃(45.03g, 158.4mmol) and DIEA (37.2g, 253.4mmol), returning to room temperature, heating to 110 deg.C for 10h, stopping heating, washing with water, filtering, evaporating to dryness, and purifying by column chromatography (petroleum ether: dichloromethane: 10: 1) to obtain 13.1g of product. Mass spectrometric analysis determined molecular mass: 778.6 (theoretical value: 778.4).

Synthesis example 2:

synthesis of V18

The synthesis method was the same as in synthesis example 1, except that the equivalent of C was replaced with raw material B, to obtain 15.4g of a product. Mass spectrometric analysis determined molecular mass: 862.9 (theoretical value: 862.5).

Synthesis example 3:

synthesis of V19

The synthesis method was the same as in synthesis example 1, except that the raw material B was replaced with an equivalent amount of D. 11.6g of the product is obtained. Mass spectrometric analysis determined molecular mass: 810.8 (theoretical value: 810.4).

Synthesis example 4:

synthesis of V23

The synthesis method was the same as in synthesis example 1, except that the raw material B was replaced with an equivalent amount of E. 16.1g of product is obtained. Mass spectrometric analysis determined molecular mass: 842.8 (theoretical value: 842.3).

Synthesis example 5:

synthesis of V142

The synthesis method was the same as in synthesis example 1, except that the raw material B was replaced with an equivalent amount of F. 14.7g of product is obtained. Mass spectrometric analysis determined molecular mass: 810.7 (theoretical value: 810.4).

Synthesis example 6:

synthesis of V155

The synthesis method was the same as in synthesis example 1, except that the raw material B was replaced with an equivalent amount of G. 15.6g of product is obtained. Mass spectrometric analysis determined molecular mass: 782.8 (theoretical value: 782.4).

Synthesis example 7:

synthesis of V178

Intermediate 7-1:

a1000 ml three-neck flask is added with the raw material A (20g, 83.36mmol), the raw material B (25.62g, 75.02mmol), Pd132(5.9g, 8.34mmol), sodium tert-butoxide (12.02g, 125.04mmol) and xylene (600ml) as solvent at room temperature, nitrogen is replaced for three times, the temperature is raised to 120 ℃ for reaction for 12h, then the heating is stopped, the mixture is filtered and evaporated to dryness, and the product is purified by column chromatography (petroleum ether: dichloromethane is 10: 1) to obtain 33.4g of the product. Mass spectrometric analysis determined molecular mass: 499.2 (theoretical value: 499.1).

Intermediate 7-2:

at room temperature, an intermediate (25g, 49.95mmol), a raw material H (9.0g, 59.94mmol), potassium hydroxide (5.6g, 99.9mmol) and dimethyl sulfoxide (600ml) are added into a 1000ml three-necked flask, three times of nitrogen is replaced, the temperature is raised to 120 ℃, reaction is carried out for 24 hours, heating is stopped, filtration and evaporation are carried out, and column chromatography purification (petroleum ether: dichloromethane ═ 10: 1) is carried out, so that 24.7g of a product is obtained. Mass spectrometric analysis determined molecular mass: 613.5 (theoretical value: 613.3).

Material V178:

dissolving intermediate 7-2(20g, 32.57mmol) in 500ml xylene, slowly adding n-butyllithium (39.08ml, 97.71mmol) dropwise at-40 deg.C, recovering to room temperature, heating at 50 deg.C for 2 hr for activation, cooling to-40 deg.C, and sequentially adding BBr slowly₃(20.38g, 81.4mmol) and DIEA (16.8g, 130.28mmol), returning to room temperature, heating to 110 deg.C for 10h, stopping heating, washing with water, filtering, evaporating to dryness, and purifying by column chromatography (petroleum ether: dichloromethane: 10: 1) to obtain 8.5g of product. Mass spectrometric analysis determined molecular mass: 587.9 (theoretical value: 587.3).

Device embodiments

The OLED includes first and second electrodes, and an organic material layer between the electrodes. The organic material may in turn be divided into a plurality of regions. For example, the organic material layer may include a hole transport region, a light emitting layer, and an electron transport region.

In a specific embodiment, a substrate may be used below the first electrode or above the second electrode. The substrate is a glass or polymer material having excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a Thin Film Transistor (TFT) may be provided on a substrate for a display.

The first electrode may be formed by sputtering or depositing a material used as the first electrode on the substrate. When the first electrode is used as an anode, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), tin dioxide (SnO) may be used₂) Oxides such as zinc oxide (ZnO)Transparent conductive materials and any combination thereof. When the first electrode is used as a cathode, a metal or an alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), or any combination thereof can be used.

The organic material layer may be formed on the electrode by vacuum thermal evaporation, spin coating, printing, or the like. The compound used as the organic material layer may be an organic small molecule, an organic large molecule, and a polymer, and a combination thereof.

The hole transport region is located between the anode and the light emitting layer. The hole transport region may be a Hole Transport Layer (HTL) of a single layer structure including a single layer containing only one compound and a single layer containing a plurality of compounds. The hole transport region may also be a multi-layer structure including at least one of a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), and an Electron Blocking Layer (EBL); wherein the HIL is located between the anode and the HTL and the EBL is located between the HTL and the light emitting layer.

The material of the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylenevinylene, polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly (3, 4-ethylenedioxythiophene)/poly (4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphorsulfonic acid (Pani/CSA), polyaniline/poly (4-styrenesulfonate) (Pani/PSS), aromatic amine derivatives such as compounds shown below in HT-1 to HT-51; or any combination thereof.

The hole injection layer is located between the anode and the hole transport layer. The hole injection layer may be a single compound material or a combination of a plurality of compounds. For example, the hole injection layer may employ one or more compounds of HT-1 to HT-51 described above, or one or more compounds of HI-1-HI-3 described below; one or more of the compounds HT-1 to HT-51 may also be used to dope one or more of the compounds HI-1-HI-3 described below.

The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit different wavelength spectra, and may also include a Host material (Host). The light emitting layer may be a single color light emitting layer emitting a single color of red, green, blue, or the like. The single color light emitting layers of a plurality of different colors may be arranged in a planar manner in accordance with a pixel pattern, or may be stacked to form a color light emitting layer. When the light emitting layers of different colors are stacked together, they may be spaced apart from each other or may be connected to each other. The light-emitting layer may be a single color light-emitting layer capable of emitting red, green, blue, or the like at the same time.

According to different technologies, the luminescent layer material can be different materials such as fluorescent electroluminescent material, phosphorescent electroluminescent material, thermal activation delayed fluorescent luminescent material, and the like. In an OLED device, a single light emitting technology may be used, or a combination of a plurality of different light emitting technologies may be used. These technically classified different luminescent materials may emit light of the same color or of different colors.

In one aspect of the invention, the light-emitting layer employs a fluorescent electroluminescence technique. The luminescent layer fluorescent host material may be selected from, but not limited to, the combination of one or more of BFH-1 through BFH-17 listed below.

In one aspect of the invention, the light-emitting layer employs a thermally activated delayed fluorescence emission technique. The host material of the light-emitting layer is selected from, but not limited to, one or more of the combinations of PH-1 to PH-85.

In one aspect of the invention, the light-emitting layer employs a thermally activated delayed fluorescence emission technique. The fluorescent dopant of the light-emitting layer can be selected from, but is not limited to, one or more of TDE1-TDE37 listed below.

In one aspect of the invention, an Electron Blocking Layer (EBL) is located between the hole transport layer and the light emitting layer. The electron blocking layer may be, but is not limited to, one or more compounds of HT-1 to HT-51 described above, or one or more compounds of PH-47 to PH-77 described above; mixtures of one or more compounds from HT-1 to HT-51 and one or more compounds from PH-47 to PH-77 may also be used, but are not limited thereto.

The OLED organic material layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may be an Electron Transport Layer (ETL) of a single-layer structure including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing a plurality of compounds. The electron transport region may also be a multilayer structure including at least one of an Electron Injection Layer (EIL), an Electron Transport Layer (ETL), and a Hole Blocking Layer (HBL).

In one aspect of the invention, the electron transport layer material may be selected from, but is not limited to, the combination of one or more of ET-1 through ET-65 listed below.

In one aspect of the invention, a Hole Blocking Layer (HBL) is located between the electron transport layer and the light emitting layer. The hole blocking layer can adopt, but is not limited to, one or more compounds from ET-1 to ET-65 or one or more compounds from PH-1 to PH-46; mixtures of one or more compounds from ET-1 to ET-65 with one or more compounds from PH-1 to PH-46 may also be used, but are not limited thereto.

An electron injection layer may also be included in the device between the electron transport layer and the cathode, the electron injection layer materials including, but not limited to, combinations of one or more of the following.

LiQ,LiF,NaCl,CsF,Li₂O,Cs₂CO₃,BaO,Na,Li,Ca,Yb,Mg。

Computational chemistry:

the invention adopts Gaussian03 to carry out quantum chemical calculation on the compounds, adopts a time-dependent density functional method to respectively carry out theoretical calculation on the compounds listed in the table 1, and the calculation result is shown in the table 1. Wherein the structural formulas of comparative compounds W1 and W2 are as follows.

Table 1: quantum chemical calculation results of the inventive Compounds and comparative examples

Compound (I)	First singlet level/eV	First triplet level/eV
			W1	2.63	2.46
W2	2.56	2.38
			V9	2.69	2.49
V18	2.71	2.55
			V19	2.72	2.54
V23	2.69	2.53
			V149	2.71	2.53
V155	2.73	2.58
			V275	2.72	2.55

The fluorescence emission wavelength of the material is related to the first singlet state energy level, and the higher the energy level, the shorter the fluorescence emission wavelength of the material, the more blue the emission. The phosphorescence emission wavelength of the material is related to the first triplet level, the higher the level, the shorter the phosphorescence emission wavelength of the material, and the bluer the emission. As can be seen from the calculation results in Table 1, the examples of the compound of the present invention have higher singlet energy than the comparative compounds W1 and W2, and the emission wavelength is expected to be shorter, which is more suitable as a light-emitting material of a blue OLED device. This is probably due to the fact that the compounds of the invention, having the group (a) directly attached to the nitrogen atom, have a higher first singlet and triplet level due to a smaller degree of molecular conjugation than the comparative compounds bridged with a benzene ring or attached to the benzene ring of the parent nucleus.

Device embodiment:

the fabrication of device example 1 was as follows:

the glass plate coated with the ITO transparent conductive layer was sonicated in a commercial detergent, rinsed in deionized water, washed in acetone: ultrasonically removing oil in an ethanol mixed solvent, baking in a clean environment until the water is completely removed, cleaning by using ultraviolet light and ozone, and bombarding the surface by using low-energy cationic beams;

placing the glass substrate with the anode in a vacuum chamber, and vacuumizing to<1×10^-5Pa, performing vacuum thermal evaporation on the anode layer film in sequence to obtain a 10nm HT-4: HI-3(97/3, w/w) mixture as a hole injection layer, a 60nm compound HT-4 as a hole transport layer and a 5nm compound HT-14 as an electron blocking layer; a binary mixture of a compound BFH-4: V9(100:3, w/w) with the particle size of 20nm is used as a light-emitting layer, wherein V9 is a light-emitting dye; 5nm of ET-23 as a hole blocking layer, 25nm of a mixture of compounds ET-61: ET-57(50/50, w/w) as an electron transport layer, 1nm of LiF as an electron injection layer, and 150nm of metallic aluminum as a cathode. The total evaporation rate of all the organic layers and LiF is controlled at 0.1 nm/s, and the evaporation rate of the metal electrode is controlled at 1 nm/s.

Device examples 2 to 21 and comparative examples 1 to 2

Organic electroluminescent devices of examples 2 to 21 and comparative examples 1 to 2 were obtained in the same manner as in example 1, except that the luminescent dye V9 in example 1 was replaced with the corresponding compounds in table 1, respectively.

The organic electroluminescent device prepared by the above process was subjected to the following performance measurement: the driving voltage and current efficiency of the organic electroluminescent devices prepared in the compounds and the comparative materials were measured at the same brightness using a digital source meter and a luminance meter. Specifically, the voltage was raised at a rate of 0.1V per second, and it was determined that the luminance of the organic electroluminescent device reached 1000cd/m²The current density is measured at the same time as the driving voltage; the ratio of the luminance to the current density is the current efficiency.

Table 2: the performance of the device prepared by the compound of the invention and the compound of the prior art as luminescent layer dye are compared

Device example numbering	Luminescent dyes	Voltage (V)	EQE(％)
				Comparative example 1	W1	5.4	5.5
Comparative example 2	W2	5.2	6.1
				Example 1	V9	4.7	7.4
Example 2	V18	4.5	7.3
				Example 3	V19	4.8	7.2
Example 4	V23	4.7	6.9
				Example 5	V149	4.6	7.6
Example 6	V155	4.7	7.7
				Example 7	V247	4.8	7.1
Example 8	V248	4.3	7.8
				Example 9	V261	4.3	7.6
Example 10	V275	4.5	7.7
				Example 11	V281	4.7	7.1
Example 12	V283	4.6	6.8
				Example 13	V178	4.8	6.9
Example 14	V204	4.7	6.7
				Example 15	V226	4.8	6.8
Example 16	V300	4.5	7.6
				Example 17	V179	4.8	7.1
Example 18	V287	4.3	7.4
				Example 19	V290	4.8	6.9
Example 20	V299	4.4	7.1
				Example 21	V298	5.0	6.8

As can be seen from table 2, the B-N type organic material of the present invention has good carrier transport properties and light emitting efficiency due to its rigid structure, and exhibits higher external quantum efficiency and lower voltage when used in an organic electroluminescent device, compared to the comparative example.

Specifically, the compound of comparative example 1 is different from example 20 only in that: in the compound V299 used in example 20, the dimethylfluorenyl group as Ar was directly connected to N of the core, whereas in the compound W1 of comparative example 1, the phenylene group was interposed between the dimethylfluorenyl group and the core, that is, Ar was not directly connected to N of the core, and thus the rigidity of the molecule was not strong enough, the efficiency was remarkably decreased when it was used in the device, and the voltage was also high. Comparative example 2 also has a similar situation in that the compound W2 used therein has a phenylene group interposed between the dimethylfluorenyl group as Ar and the parent nucleus, so that the rigidity of the molecule is not strong enough, the efficiency is remarkably reduced when it is used in a device, and the voltage is also high.

Although the invention has been described in connection with the embodiments, the invention is not limited to the embodiments described above, and it should be understood that various modifications and improvements can be made by those skilled in the art within the spirit of the invention, and the scope of the invention is outlined by the appended claims.

Claims

1. An organic compound having a structure represented by formula (1):

wherein,

X¹selected from the group consisting of CR¹R²、NR³O, S or SiR⁴R⁵And when R is one of³When present, R³Optionally linked to ring D to form a fused ring structure;

ring E, ring D and ring A are each independently selected from one of substituted or unsubstituted C6-C30 aromatic rings, substituted or unsubstituted C3-C30 aromatic heterocycles;

Z¹selected from C or Si;

Z²selected from the group consisting of CR⁶R⁷、NR⁸、O、S、SiR⁹R¹⁰A is 0 or 1, and when a is 0, it represents Z²In the absence of, in formula (a) and Z²The two atoms connected are directly connected by a single bond;

Y⁵～Y⁸each independently selected from CR¹³Or N;

R¹³independently selected from hydrogen, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 naphthenic base, substituted or unsubstituted COne of unsubstituted C1-C10 alkoxy, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted C3-C30 heteroaryl, R¹³Optionally, each independently connects with the connected aromatic ring or aromatic heterocyclic ring to form a ring;

2. An organic compound according to claim 1, wherein X is¹Is NR³Said R is³Optionally joined to ring D to form a fused ring structure,

preferably R³Is substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl,

more preferably R³Is one of the following substituted or unsubstituted groups: phenyl, naphthyl, anthracenyl, biphenyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, furyl, benzofuryl, dibenzofuryl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, acridinyl, carbazolyl.

3. The organic compound according to claim 1, wherein ring E, ring D and ring a are each independently selected from one of a substituted or unsubstituted C6-C14 aromatic ring, a substituted or unsubstituted C3-C14 aromatic heterocycle.

4. The organic compound according to claim 1, wherein ring E and ring D are each independently a structure represented by formula (b):

5. The organic compound according to claim 1, wherein ring a is of the structure of formula (b'):

wherein one represents the site at which ring A is attached to the six-membered ring of formula (1) in which B and N are located, and the other represents ring A and B and X¹At the site of attachment of the six-membered ring, Z^5’～Z^7’Each independently selected from CR¹⁴And N; the R is¹⁴Independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 silyl, amino, C6-C30 arylamino, C3-C30 heteroaryl amino, C6-C30 aryl and C3-C30 heteroaryl, wherein R is selected from one of C3-C10 heteroaryl¹⁴Optionally fused to form a ring with the aromatic ring or heterocyclic ring to which it is attached.

6. The organic compound of claim 1, wherein Z is¹Is C, a is 0; or Z¹Is C, a is 1, Z²Selected from the group consisting of CR⁶R⁷、NR⁸And O.

7. An organic compound according to claim 1, wherein R is¹¹And R¹²Each independently being methyl or phenyl.

8. An organic compound according to claim 1, wherein Y is¹～Y⁴In the total number of N, Y is 0-1⁵～Y⁸0-1N in the total;

preferably Y¹～Y⁴Each independently selected from C, CR¹³，Y⁵～Y⁸Each independently selected from CR¹³；

More preferably R¹³Is hydrogen.

9. The organic compound according to claim 1, wherein ring E, ring D and ring a have a substituent, each of which is independently one selected from a substituted or unsubstituted C1 to C10 chain alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group;

the substituents on ring E, ring D and ring a are preferably each independently selected from one of the following groups:

the substituents on ring E, ring D and ring a are more preferably each independently selected from one of the following groups:

10. an organic compound according to claim 9, wherein the substituent is present para to B or N on ring E and ring D, and/or para to B on ring a.

11. The organic compound according to claim 1, having a structure represented by V1 to V303:

12. use of an organic compound according to any one of claims 1 to 11 as a light-emitting layer material in an organic electroluminescent device, preferably in an organic electroluminescent device.

13. An organic electroluminescent device comprising a first electrode, a second electrode and an organic layer interposed between the first electrode and the second electrode, characterized in that the organic layer contains the organic compound according to any one of claims 1 to 11.