CN111233826A

CN111233826A - Dibenzothiophene compound containing fluoranthene group and organic electroluminescent device thereof

Info

Publication number: CN111233826A
Application number: CN201811444457.6A
Authority: CN
Inventors: 黄贺隆; 徐伯伟; 赖振昌; 林祺臻; 殷力嘉; 张敏忠
Original assignee: E Ray Optoelectronics Technology Co Ltd
Current assignee: E Ray Optoelectronics Technology Co Ltd
Priority date: 2018-11-29
Filing date: 2018-11-29
Publication date: 2020-06-05

Abstract

A fluoranthenyl-containing dibenzothiophene compound having the structure of formula (I) and an organic electroluminescent device using the same, wherein fluoranthenyl is bonded to A₁To A₃One of (a); a. the₁To A₃、X₁To X₂And R₁To R₇As defined in the specification.

Description

Dibenzothiophene compound containing fluoranthene group and organic electroluminescent device thereof

Technical Field

The present invention relates to a material for an organic electroluminescent device and an organic electroluminescent device using the same.

Background

Recently, organic electroluminescent devices (OLEDs) have been commercially attractive due to advantages of long lifetime, high efficiency, low driving voltage, wide color gamut, and low cost in high-density pixel displays with high luminance, and development of novel organic materials is particularly important to meet the application of the organic electroluminescent devices.

A typical OLED has at least one organic emissive layer (organic emissive) sandwiched between an anode and a cathode. When a current is applied, the anode injects holes and the cathode injects electrons into the organic emissive layer or layers, and the injected holes and electrons each migrate to the oppositely charged electrode. When electrons and holes are confined to the same molecule, an "exciton (exiton)" is formed, which has a confined electron-hole pair in an excited energy state, which relaxes by a light-emitting mechanism to emit light. In order to improve the charge transport capability and the light emitting efficiency of these devices, one or more additional layers, such as an electron transport layer and/or a hole transport layer, or an electron blocking layer and/or a hole blocking layer, are combined beside the light emitting layer. In the literature, it is well documented that a host material may be blended with another guest material to improve device performance and to adjust chromaticity. Several OLED materials and device configurations are described in U.S. patent nos. 4769292, 5844363, 5707745, 6596415, and 6465115, which are incorporated herein by reference in their entirety.

Reasons for fabricating OLEDs having a multi-layered thin film structure include stabilization of the interface between the electrodes and the organic layers and coordination of organic materials. In organic materials, the mobility of electrons and holes is significantly different, and if a hole transporting and electron transporting layer is used, holes and electrons can be efficiently transported to the emitting layer, so that the density of the electrons and holes in the emitting layer is balanced, and the light emitting efficiency is increased. Proper incorporation of the organic layers can improve the device efficiency and lifetime.

To date, dibenzothiophene compounds have been used in the electron transport layer of OLED devices, and besides the easy-to-obtain benefits of the compounds, their coplanar properties may also facilitate the intermolecular interaction, but there is still room for improvement in the stability and driving voltage of organic electroluminescent devices, and it is still difficult to meet the requirements of all practical display applications. Yi radium photoelectric technology has been applied in 2013 and granted us 9153787 patent in 2015.

However, there is still a need to develop an organic material that can significantly improve the lifetime of an organic electroluminescent device and enhance the carrier mobility to meet diverse applications.

Disclosure of Invention

The invention aims to provide a material for an organic electroluminescent device, which has long service life, high carrier mobility and excellent heat resistance.

The invention provides a fluoranthenyl-containing dibenzothiophene compound with a structure shown as a formula (I):

wherein fluoranthene group is bonded to A₁To A₃One of (a);

A₁to A₃One of which is a single bond and is linked to the fluoranthene group, and the remainder A₁To A₃Each independently represents hydrogen, deuterium, C_1-4Alkyl radical, C_1-4Alkoxy, amino, silyl, cyano, substituted or unsubstituted C containing at least one heteroatom selected from the group consisting of N, O, and S_5-30Heteroaryl, substituted or unsubstituted C_6-30Aryl radicals or the remainder of A₁To A₃And R₁Form C with an adjacent aryl group_6-18A condensed ring aromatic hydrocarbon group:

R₁to R₇Each independently represents hydrogen, deuterium, C_1-4Alkyl radical, C_1-4Alkoxy, amino, silyl, cyano, substituted or unsubstituted C containing at least one heteroatom selected from the group consisting of N, O, and S_5-12Heteroaryl, substituted or unsubstituted C_6-30Aryl or R₂To R₅With an adjacent aryl group to form C_6-18Condensed ring aromatic hydrocarbon group or R₆To R₇Form C with an adjacent aryl group_6-18A condensed ring aromatic hydrocarbon group: and

X₁and X₂Each independently represents substituted or unsubstituted C_5-30Aryl, substituted or unsubstituted C containing at least one heteroatom selected from the group consisting of N, O, and S_5-10A heteroaryl group.

In one embodiment, A of the fluoranthenyl-containing dibenzothiophene compound with the structure of formula (I)₁To A₃Is a single bond and is linked to Z, and A₁And A₂Or A₂And A₃Or A₃And R₁Together with an adjacent aryl radical to form C₆A condensed ring aromatic hydrocarbon group, the remainder of A₁To A₃And R₁Denoted as hydrogen.

In another embodiment, A of the fluoranthenyl-containing dibenzothiophene compound with the structure of formula (I)₁To A₃One of which is a single bond and is linked to the fluoranthene group, and the remainder A₁To A₃And R₁Denoted as hydrogen.

In one embodiment, R of the fluoranthenyl-containing dibenzothiophene compound with the structure of formula (I)₂To R₅Each independently represents hydrogen, substituted or unsubstituted C_6-30Aryl radical, R₂To R₅Wherein adjacent two form C with adjacent aryl₆A condensed ring aromatic hydrocarbon group, wherein the substituted or unsubstituted C_6-30The aryl group is selected from one of the group consisting of phenyl, tolyl, naphthyl, phenylanthryl, phenanthryl, benzophenanthryl, pyrenyl and perylenyl.

In one embodiment, when fluoranthenyl is bound to A₁When in position, the fluoranthenyl-containing dibenzothiophene compound of formula (I) is selected from one of the group consisting of:

and

wherein, Y₁To Y₄Each independently represents deuterium, C_1-4Alkyl radical, C_1-4Alkoxy, amino, silyl, cyano, substituted or unsubstituted C_6-30Aryl, substituted or unsubstituted C containing at least one heteroatom selected from the group consisting of N, O, and S_5-12A heteroaryl group; n, p, q are integers selected from 0 to 4; and m is an integer selected from 0 to 3.

In another embodiment, when the fluoranthenyl-containing dibenzothiophene compound of formula (I) is one of the structures (I-2) to (I-4), m, n, p and q are all integers of 0 or 1, and Y is₁To Y₄Each independently represents substituted or unsubstituted C_6-30And (4) an aryl group.

In one embodiment, when fluoranthenyl is bound to A₂When in position, the fluoranthenyl-containing dibenzothiophene compound of formula (I) is selected from one of the group consisting of:

and

wherein, Y₁To Y₄Each independently represents deuterium, C_1-4Alkyl radical, C_1-4Alkoxy, amino, silyl, cyano, substituted or unsubstituted C_6-30Aryl, substituted or unsubstituted C containing at least one heteroatom selected from the group consisting of N, O, and S_5-12A heteroaryl group; n, p, q are integers selected from 0 to 4; and m is an integer selected from 0 to 3. More specifically, the fluoranthenyl-containing dibenzothiophene compound with the structure of formula (I) is shown as formula (I-51):

in another embodiment, when the fluoranthenyl-containing dibenzothiophene compound of formula (I) is one of the structures (I-5) to (I-7), m, n, p and q are all integers of 0 or 1, and Y is₁To Y₄Each independently represents substituted or unsubstituted C_6-30And (4) an aryl group.

In one embodiment, when fluoranthenyl is bound to A₃When in position, the fluoranthenyl-containing dibenzothiophene compound of formula (I) is selected from one of the group consisting of:

and

In another embodiment, the fluoranthenyl-containing dibenzo of formula (I)When the thiophene compound is one of the structures (I-8) to (I-10), m, n, p and q are all integers of 0 or 1, and Y₁To Y₄Each independently represents substituted or unsubstituted C_6-30And (4) an aryl group.

According to the invention, X₁And X₂Each independently represents substituted or unsubstituted C_5-30Aryl, substituted or unsubstituted C containing at least one heteroatom selected from the group consisting of N, O, and S_5-10Heteroaryl, and in each of the embodiments, the X₁And X₂Examples of (b) include one each independently selected from the group consisting of phenyl, tolyl, pyridyl and naphthyl. In another embodiment, the "tolyl" group is a 3-tolyl, 4-tolyl, or 2,4, 6-trimethylphenyl group; the "pyridyl" is 4-pyridyl; and the "naphthyl" group is a 1-naphthyl or 2-naphthyl group.

In one embodiment, the fluoranthenyl-containing dibenzothiophene compound of formula (I) is selected from one of the group consisting of:

and

in one embodiment, X is₁And X₂Are identical or different, wherein X is particularly preferred₁And X₂The same structure is preferred.

In one embodiment, when the fluoranthenyl-containing dibenzothiophene compound having the structure of formula (I) is one of the structures (I-11) to (I-13), X is₁And X₂Each independently selected from the group consisting of phenyl, 4-tolyl, 2,4, 6-trimethylphenyl, 4-pyridyl, 1-naphthyl and 2-naphthyl. More specifically, the X₁And X₂May both be phenyl.

and

the present invention also provides an organic electroluminescent device comprising: a cathode; an anode; and an organic layer interposed between the cathode and the anode, the organic layer comprising the fluoranthenyl-containing dibenzothiophene compound of the present invention having the structure of formula (I).

In one embodiment, the organic layer is an electron transport layer and has a thickness of 15 nm to 40 nm. In addition, the electron transport layer may further include an N-type conductivity dopant, and the N-type conductivity dopant is included in an amount of more than 0 wt% to 50 wt%. For example, the N-type electrically conductive dopant is lithium quinolinate.

According to the invention, the fluorescent anthracene group-containing dibenzothiophene compound with the structure of the formula (I) provided by the invention can effectively improve the service life of an organic electroluminescent device, improve the carrier mobility and provide the advantages of good heat resistance.

Drawings

Embodiments of the invention are described by way of example with reference to the accompanying drawings:

FIG. 1 is a schematic cross-sectional view of one embodiment of an organic electroluminescent device of the present invention;

FIG. 2 is a schematic cross-sectional view of another embodiment of an organic electroluminescent device of the present invention; and

fig. 3 is a schematic cross-sectional view of yet another embodiment of the organic electroluminescent device of the present invention.

Wherein the reference numerals are as follows:

100. 200, 300 organic electroluminescent device

110. 210, 310 substrate

120. 220, 320 anode

130. 230, 330 hole injection layer

140. 240, 340 hole transport layer

150. 250, 350 luminous layer

160. 260, 360 electron transport layer

170. 270, 370 electron injection layer

180. 280, 380 cathodes

245. 345 electron blocking layer

355 a hole blocking layer.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and those skilled in the art can easily understand the advantages and effects of the present invention from the disclosure of the present specification. The invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present disclosure. Moreover, all ranges and values herein are inclusive and combinable. Any number or point within the ranges set forth herein, e.g., any integer, may be treated as the minimum or maximum value to derive a lower range, etc.

Herein, "substituted" in the expression "substituted or unsubstituted" means that a hydrogen atom in a certain functional group is replaced with another atom or group (i.e., substituent). Each of the substituents is independently at least one selected from the group consisting of: deuterium, halogen, C_1-30Alkyl radical, C_1-30Alkoxy radical, C_6-30Aryl radical, C_5-30Heteroaryl, Via C_6-30Aryl substituted C_5-30Heteroaryl, benzimidazolyl, C_3-30Cycloalkyl radical, C_5-7Heterocycloalkyl, tri-C_1-30Alkylsilyl, tri-C_1-30Aryl silyl, di-C_1-30Alkyl radical C_6-30Aryl silane radical, C_1-30Alkyl di C_6-30Aryl silane radical, C_2-30Alkenyl radical, C_2-30Alkynyl, cyano, di-C_1-30Alkylamino radical, di-C_6-30Arylboron radical, di-C_1-30Alkyl boron radical, C_1-30Alkyl radical, C_6-30Aryl radical C_1-30Alkyl radical, C_1-30Alkyl radical C_6-30Aryl, carboxyl, nitro and hydroxyl.

Herein, "aryl" means an aryl group or an (arylene) group, which means a monocyclic or fused ring derived from aromatic hydrocarbons, and includes phenyl, biphenyl, terphenyl (terphenyl), naphthyl, binaphthyl, phenylnaphthyl, naphthylphenyl, fluorenyl (fluoroenyl), phenylfluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthryl, phenylphenanthenyl, anthryl, indenyl, benzophenanthrenyl (triphenylenyl), pyrenyl, condensed tetraphenyl, perylenyl, chrysenyl (chrysenyl), naphthacenyl, fluoranthenyl (fluoranthenyl), and the like.

As used herein, "heteroaryl" means heteroaryl or (arylene) heteroaryl, which means an aryl group containing a ring backbone atom containing at least one heteroatom selected from the group consisting of N, O, and S, and may be a monocyclic ring such as furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl (Isoxazole), oxazolyl (oxazole), oxadiazolyl (oxadiazine), triazinyl (triazone), tetrazinyl (tetrazine), triazolyl (triazone), tetrazolyl (tetrazole), furazanyl (furazanyl), pyridyl, pyrazinyl (pyrazine), pyrimidinyl, pyridazinyl (pyridazyl), and the like, or a fused ring condensed with at least one benzene ring such as benzofuryl, benzothienyl, isobenzofuryl, dibenzothienyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, Quinolyl, isoquinolyl, cinnolinyl (cinnolinyl), quinazolinyl (quinazoline), quinoxalinyl (quinaxline), carbazolyl (carbazolyl), phenoxazolyl (phenoxazole), phenanthridinyl (phenothradine), benzoxadienyl (benzodioxolyl), dihydroacridinyl (dihydroacridinine), and the like.

In one embodiment, the fluoranthenyl-containing dibenzothiophene compound having the structure of formula (I) is selected from table 1, but not limited thereto.

TABLE 1

The dibenzothiophene compound containing the fluoranthenyl with the structure of the formula (I) can bear high temperature accumulated by heat storage when the device is used for a long time due to the fact that the glass transition temperature of the dibenzothiophene compound is 158-184 ℃, and the operation stability and the service life of the device are improved.

The following scheme illustrates a typical synthetic route for fluoranthenyl-containing dibenzothiophene compounds having the structure of formula (I).

Fluoranthene compound with bromine radical and dibenzothiophene compound with boric acid are put into a reaction tank, and toluene is added. Dissolving potassium carbonate in deionized water, adding into a reaction tank, and adding tetrakis (triphenylphosphine) palladium (Pd (PPh)₃)₄) And heating and stirring the ethanol. Heat to 80 ℃ and react overnight. And adding deionized water after the reaction is finished, stirring for 30 minutes, stopping stirring, standing for layering, extracting, adding silica gel for chromatographic purification, concentrating to a thick state, adding hexane for enhanced precipitation, combining organic layers, and filtering the solid to obtain a milk light yellow solid, namely the anthryl-containing dibenzothiophene compound with the structure of the formula (I).

The present invention also provides an organic electroluminescent device comprising: a cathode; an anode; and an organic layer interposed between the cathode and the anode, the organic layer containing a fluoranthenyl-containing dibenzothiophene compound having the structure of formula (I) as described above.

The organic layer of the organic electroluminescent device of the present invention may be an electron transport layer, an electron injection layer, a light emitting layer, a hole blocking layer or an electron blocking layer, and in addition to the organic layer, the organic electroluminescent device may further include at least one layer selected from the group consisting of an electron transport layer, an electron injection layer, a light emitting layer, a hole blocking layer and an electron blocking layer, which is different from the organic layer, wherein the light emitting layer further includes a fluorescent or phosphorescent dopant, and a host material corresponding to the fluorescent or phosphorescent dopant, respectively.

In one embodiment, the organic layer containing the fluoranthenyl-containing dibenzothiophene compound with the structure of formula (I) is an electron injection layer or an electron transport layer. In another embodiment, the organic layer is preferably an electron transport layer and has a thickness of 15 nm to 40 nm; the electron transport layer may use the fluoranthenyl-containing dibenzothiophene compound of formula (I) as a single material, or may use the fluoranthenyl-containing dibenzothiophene compound of formula (I) in combination with an electrically conductive dopant.

In another embodiment, the electron transport layer further comprises an N-type conductivity dopant, wherein the N-type conductivity dopant and the fluoranthenyl-containing dibenzothiophene compound with the structure of formula (I) according to the present invention generate a chelating action (chelation), such that electrons can be more easily injected into the electron transport layer from the cathode, and thus the problems of phase separation and formation of quenching centers caused by poor compatibility between metal and electron transport host material in the prior art are solved, and the electron transport efficiency of the electron transport layer is effectively improved.

The N-type conductivity dopant applied in the electron transport layer can be nitrate, carbonate, phosphate or quinolinate of organic alkali metal/alkaline earth metal. Specifically, lithium carbonate, lithium quinolate (Liq), lithium azide (lithium azide), rubidium carbonate, silver nitrate, barium nitrate, magnesium nitrate, zinc nitrate, cesium carbonate, cesium fluoride, cesium azide, etc., wherein the N-type conductivity dopant is preferably lithium quinolate.

In one embodiment, the N-type conductivity dopant is present in an amount greater than 0 wt% to 50 wt% based on the weight of the electron transport layer.

The structure of the organic electroluminescent device of the present invention will be described with reference to the drawings.

Fig. 1 is a schematic cross-sectional view of an embodiment of the organic electroluminescent device of the present invention. The organic electroluminescent device 100 includes a substrate 110, an anode 120, a hole injection layer 130, a hole transport layer 140, an emission layer 150, an electron transport layer 160, an electron injection layer 170, and a cathode 180. The organic electroluminescent device 100 may be fabricated by sequentially depositing the above layers.

Fig. 2 is a schematic cross-sectional view of another embodiment of the organic electroluminescent device of the present invention. The organic electroluminescent device 200 includes a substrate 210, an anode 220, a hole injection layer 230, a hole transport layer 240, an electron blocking layer 245, a light emitting layer 250, an electron transport layer 260, an electron injection layer 270, and a cathode 280, and is different from fig. 1 in that the electron blocking layer 245 is disposed between the hole transport layer 240 and the light emitting layer 250.

Fig. 3 is a schematic cross-sectional view of yet another embodiment of the organic electroluminescent device of the present invention. The organic electroluminescent device 300 includes a substrate 310, an anode 320, a hole injection layer 330, a hole transport layer 340, an electron blocking layer 345, a light emitting layer 350, a hole blocking layer 355, an electron transport layer 360, an electron injection layer 370, and a cathode 380, and is different from fig. 2 in that the hole blocking layer 355 is disposed between the light emitting layer and the electron transport layer 360.

The organic electroluminescent device may be fabricated in an inverted structure of the devices shown in fig. 1 to 3. One or more layers can be added or removed according to the requirement.

The hole injection layer, the hole transport layer, the electron blocking layer, the hole blocking layer, the electron blocking layer and the electron injection layer can be made of common materials, for example, the electron transport material for forming the electron transport layer is different from the material of the light emitting layer and has hole transport property, so that holes are promoted to migrate in the electron transport layer, and the accumulation of carriers caused by the dissociation energy difference of the light emitting layer and the electron transport layer is prevented.

The fluoranthenyl-containing dibenzothiophene compound with the structure of formula (I) is used for an electron transport layer, so that electrons are effectively transported to the light-emitting layer due to good carrier mobility, the density balance of the electrons and holes in the light-emitting layer is facilitated, and the light-emitting efficiency and the driving stability are improved.

In addition, U.S. patent No. 5844363, the entire contents of which are incorporated herein by reference, discloses a flexible transparent substrate incorporating an anode. A p-type doped hole transport layer as exemplified in U.S. patent No. 20030230980 was formed in a molar ratio of 50: 1 doping F in m-MTDATA₄TCNQ, the entire contents of which are incorporated herein by reference. An n-type doped electron transport layer as exemplified in U.S. patent No. 20030230980 was formed in a molar ratio of 1: doping of lithium in BPhen, the entire contents of which are incorporated herein by reference. As exemplified in us patent nos. 5703436 and 5707745, the entire contents of which are incorporated herein by reference, the cathode has a thin layer of a metal, such as: magnesium/silver (Mg: Ag), and a transparent conductive Layer (ITO Layer) covering the metal thin Layer by sputter deposition. The application and principles of each barrier layer disclosed in U.S. patent nos. 6097147 and 20030230980 are incorporated herein by reference in their entirety. The implant layer exemplified in U.S. patent No. 20040174116 and the protective layer described in the same reference are incorporated herein in their entirety.

Structures and materials not specifically described may also be applied to the present invention, such as organic electroluminescent devices comprising polymer materials (PLEDs) as disclosed in U.S. patent No. 5247190, which is incorporated herein by reference in its entirety. Further, an organic electroluminescent device having a single organic layer or an organic electroluminescent device formed by stacking as disclosed in U.S. Pat. No. 5707745, the entire contents of which are incorporated herein by reference.

Any of the layers in the various embodiments may be deposited using any suitable method, unless otherwise specified. For organic layers, preferred methods include thermal evaporation and jet printing as disclosed in U.S. Pat. Nos. 6013982 and 6087196, the entire contents of which are incorporated herein by reference; the organic vapor deposition (OVPD) method disclosed in U.S. patent No. 6337102, which is incorporated herein by reference in its entirety; U.S. Pat. No. 10/233470 discloses an Organic Vapor Jet Printing (OVJP) method, the entire contents of which are incorporated herein by reference. Other suitable methods include spin coating and solution-based processes. The solution-based process is preferably carried out in a nitrogen or inert gas environment. For the other layers, a preferred method includes thermal evaporation. Preferred patterning methods include processes such as cold welding by shadow mask deposition as disclosed in U.S. Pat. Nos. 6294398 and 6468819, the entire contents of which are incorporated herein by reference, and processes that integrate jet printing or organic vapor jet printing deposition with patterning. Of course, other methods may be used. The materials used for deposition may be tailored to the particular deposition process employed.

The dibenzothiophene compound containing the fluoranthenyl with the structure of formula (I) can be prepared into an amorphous film applied to an organic electroluminescent device by a vacuum deposition or spin coating method. When used in any of the above organic layers, the compounds exhibit long lifetimes and good thermal stability.

The organic electroluminescent device can be applied to a single device, and the structure of the organic electroluminescent device is an array configuration or a device with a cathode and an anode arranged in an array X-Y coordinate. Compared with the known device, the invention can obviously prolong the service life of the organic electroluminescent device.

The following examples are provided to illustrate the various features and effects of the present invention. The detailed description is to be construed as merely illustrative of the invention and not limitative of the invention to the particular embodiments shown.

Synthesis example 1: synthesis of Compound 1-1

Reacting 3-bromo-7,12-diphenylbenzo [ k]Fluoranthene (3-bromo-7, 12-diphenylbenzol [ k ]]fluoranthene) (10g, 20.68mmole) with dibenzo [ b, d ]]Thiophene-1-boronic acid (dibenzo [ b, d)]thiophen-1-ylboronic acid) (4.95g, 21.72mmole) was placed in a reaction tank, and 100 ml of toluene was added. Potassium carbonate (10g, 72.4mmole) was dissolved in 70 ml of deionized water and added to the reaction tank, while tetrakis (triphenylphosphine) palladium (Pd (P) was addedPh₃)₄) (1.19g, 1.343mmole) and 30 ml of ethanol, and the heating and stirring are started, the temperature is heated to 80 ℃ and the reaction is carried out overnight. And adding 400 ml of deionized water after the reaction is finished, stirring for 30 minutes, stopping stirring, standing for layering, extracting, adding silica gel for chromatographic purification, concentrating to a thick state, adding 300 ml of hexane for enhanced separation, combining organic layers, and filtering solids to obtain light yellow milk solids (about 7.8g), namely the product.

¹H NMR(CDCl₃,400MHz),δ7.938(d,1H),7.774(d,1H),7.724-7.580(m,11H),7.503(t,1H),7.443-7.423(m,2H),7.363(d,1H),7.293-7.214(m,4H),7.124(t,1H),6.831(t,1H),6.771(d,1H),6.703(d,1H),6.621(d,1H).

Synthesis example 2: synthesis of Compound 2-1

Reacting 3-bromo-7,12-diphenylbenzo [ k]Fluoranthene (3-bromo-7, 12-diphenylbenzol [ k ]]fluoranthene) (15g, 31.03mmole) with dibenzo [ b, d ]]Thiophene-2-boronic acid (dibenzo [ b, d)]thiophen-2-ylboronic acid) (7.43g, 32.58mmole) was placed in a reaction tank, and 150 ml of toluene was added. Potassium carbonate (15g, 108.6mmole) was dissolved in 105 ml of deionized water and added to the reaction tank, while tetrakis (triphenylphosphine) palladium (Pd (PPh) was added₃)₄) (1.79g, 1.551mmole) and 45 ml of ethanol, and the heating and stirring are turned on, heated to 80 ℃ and reacted overnight. Adding 400 ml of deionized water after the reaction is finished, stirring for 30 minutes, stopping stirring, standing for layering, extracting, adding silica gel for chromatographic purification, concentrating to a thick state, adding 300 ml of hexane for enhanced separation, combining organic layers, and filtering solids to obtain light yellow milk solids (about 12g), namely the product.

¹H NMR(CDCl₃,400MHz)δ8.272(s,1H),8.133(dd,1H),7.944(d,1H),7.883(dd,1H),7.845(d,1H),7.721-7.593(m,13H),7.500-7.409(m,5H),7.331(m,1H),6.710(d,1H),6.668(d,1H).

Synthesis example 3: synthesis of Compound 3-1

Reacting 3-bromo-7,12-diphenylbenzo [ k]Fluoranthene (3-bromo-7, 12-diphenylbenzol [ k ]]fluoranthene) (10g, 20.68mmole) with dibenzo [ b, d ]]Thiophene-3-boronic acid (dibenzo [ b, d ]]thiophen-3-ylboronic acid) (4.95g, 21.72mmole) was placed in a reaction tank, and 100 ml of toluene was added. Potassium carbonate (10g, 72.4mmole) was dissolved in 70 ml of deionized water and added to the reaction tank, while tetrakis (triphenylphosphine) palladium (Pd (PPh) was added₃)₄) (1.19g, 1.343mmole) and 30 ml of ethanol, and the heating and stirring are started, the temperature is heated to 80 ℃ and the reaction is carried out overnight. And adding 400 ml of deionized water after the reaction is finished, stirring for 30 minutes, stopping stirring, standing for layering, extracting, adding silica gel for chromatographic purification, concentrating to a thick state, adding 300 ml of hexane for enhanced separation, combining organic layers, and filtering solids to obtain light yellow milk solids (about 7g), namely the product.

¹H NMR(CDCl₃,400MHz),δ7.937(d,1H),7.774(d,1H),7.724-7.595(m,11H),7.503(t,1H),7.443-7.424(m,2H),7.363(d,1H),7.293-7.216(m,4H),7.125(t,1H),6.824(t,1H),6.771(d,1H),6.704(d,1H),6.622(d,1H).

The physical property values of the above-mentioned materials are shown in table 2, and the measurement methods of the respective physical property values are shown below.

(1) Temperature of thermal cracking (T)_d)

The thermal cracking properties of the resulting compound were measured using a thermogravimetric analyzer (Perkin Elmer, TGA 8000) at a temperature programmed rate of 20 ℃/min under normal pressure and nitrogen atmosphere, and the temperature at which the weight was reduced to 95% of the initial weight was taken as the thermal cracking temperature (T_d)。

(2) Glass transition temperature (T)_g) And melting point (T)_m)

The resulting compound was measured using a differential scanning thermal analyzer (DSC; Perkin Elmer, DSC 8000) at a temperature programmed rate of 20 deg.C/min.

(3) Energy level of Highest Occupied Molecular Orbital (HOMO)

In addition, the compound was formed into a thin film, and the ionization potential value was measured using a photoelectron spectrophotometer (Riken Keiki, Surface Analyzer) under the atmospheric air, and the value was further converted to obtain the HOMO level.

(4) Absorption wavelength, energy level of Lowest Unoccupied Molecular Orbital (LUMO), and energy gap value (E)_g)

A thin film of the above compound was measured for a boundary value of absorption wavelength by a UV/VIS spectrophotometer (Perkin Elmer, Lambda 20), and the value was converted into an energy gap value (E)_g) And adding the energy gap value and the value of the HOMO energy level to obtain the LUMO energy level.

(5) Triplet energy value (E)_T)

The luminescence spectrum was measured at 77K using a fluorescence spectrometer (Perkin Elmer, LS 55) and calculated to give E_T。

TABLE 2

Preparation example 1-1: fabrication of organic electroluminescent devices

Before the substrate is loaded into the evaporation system for use, the substrate is cleaned by a solvent and ultraviolet ozone for degreasing. The substrate is then transferred to a vacuum deposition chamber where all layers are deposited on top of the substrate. The layers shown in FIG. 1 were deposited by a heated boat (boat) at about 10 deg.f^-6Vacuum degree of the tray is sequentially deposited:

a) a hole injection layer having a thickness of 20 nm comprising an HTM doped with 6% by weight of a p-type electrically conductive dopant, wherein the p-type electrically conductive dopant is available from shanghai vash chemical co, inc, and the HTM is available from Merck & co, inc;

b) a hole transport layer, 150 nm thick, HTM;

c) exciton blocking layer, 10 nm thick, HT (Yi radium photoelectric preparation);

d) a light emitting layer with a thickness of 25 nm and comprising EBH doped with 4% by weight of BD, wherein BD and EBH are prepared by Yi radium photoelectricity;

e) an electron transport layer with a thickness of 20 nm, comprising compound 1-1 and doped lithium quinolinate (Liq) in a weight ratio of 7: 3;

f) an electron injection layer with a thickness of 1.5 nm, Liq; and

g) a cathode having a thickness of about 150 nanometers and comprising aluminum (a 1).

The device structure may be represented as: ITO/HTM p-type electrically conductive dopant (20 nm)/HTM (150 nm)/HT (10 nm)/EBH: BD (25 nm)/Compound 1-1: liq (20 nm)/Liq (1.5 nm)/Al (150 nm).

After deposition to form the layers, the device is transferred from the deposition chamber to a dry box and then encapsulated with a UV curable epoxy resin and a glass cover plate containing a moisture absorber. The organic electroluminescent device had a light-emitting region of 9 mm square.

Preparation examples 1-2 to 1-3: fabrication of organic electroluminescent devices

Examples 1-2 and preparation examples 1-3 were prepared as in the layer structure of preparation example 1-1, except that the weight ratio of compound 1-1 and doped lithium quinolate (Liq) of the electron transport layer in preparation example 1-1 was changed to 6:4 and 5:5, respectively.

Preparation example 2-1: fabrication of organic electroluminescent devices

Example 2-1 was prepared as in the layer structure of preparation example 1-1 except that compound 1-1 of the electron transport layer in preparation example 1-1 was replaced with compound 2-1.

Preparation examples 2-2 to 2-3: fabrication of organic electroluminescent devices

Example 2-2 and preparation example 2-3 were prepared as the layer structure of preparation example 2-1 except that the weight ratio of compound 2-1 and doped lithium quinolate (Liq) of the electron transport layer in preparation example 2-1 was changed to 6:4 and 5:5, respectively.

Preparation example 3-1: fabrication of organic electroluminescent devices

Example 3-1 was prepared as in the layer structure of preparation example 1-1, except that compound 1-1 of the electron transport layer in preparation example 1-1 was replaced with compound 3-1.

Preparation examples 3-2 to 3-3: fabrication of organic electroluminescent devices

Example 3-2 and preparation example 3-3 were prepared as in the layer structure of preparation example 3-1, except that the weight ratio of compound 3-1 and doped lithium quinolate (Liq) of the electron transport layer in preparation example 3-1 was changed to 6:4 and 5:5, respectively.

Comparative preparation example 1: fabrication of organic electroluminescent devices

An organic electroluminescent device was fabricated into a layer structure similar to that of preparation examples 1-3, except that compound 1-1 of the electron transport layer in preparation examples 1-3 was replaced with compound EET 09. Wherein the compound EET09 is as described in japanese patent No. 2011003793 a.

The electroluminescent properties of the organic electroluminescent devices prepared as described above were measured at room temperature using a constant current Source (KEITHLEY2400Source Meter, made by Keithley Instruments, Inc., Cleveland, Ohio) and a photometer (PHOTO RESEARCH SpectraScan PR 650, made by Photoresearch, Inc., Chatsworth, Calif.) and their driving voltages (V.sub.V.sub._d) Values of the luminous efficiency, color coordinate y (CIE-y), blue index (blue index) and LT95 at a current density of 50J are shown in tables 3 to 5, wherein LT95 value is defined as the time taken for the luminance level to fall to a level of 95% relative to the initial luminance as a measure for evaluating the lifetime or stability of the organic electroluminescent device.

TABLE 3

TABLE 4

TABLE 5

As described above, it can be seen that the organic electroluminescent device including the fluoranthenyl-containing dibenzothiophene compound having the structure of formula (I) of the present invention exhibits good heat resistance, and thus, the organic electroluminescent device of the present invention can meet various application requirements and has an extremely high technical value.

The above embodiments are merely illustrative, and not restrictive, of the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Therefore, the scope of the invention is defined by the appended claims, and is covered by the disclosure unless it does not affect the effect and the implementation of the invention.

Claims

1. A fluoranthenyl-containing dibenzothiophene compound having the structure of formula (I):

characterized in that fluoranthene group is bonded to A₁To A₃One of (a);

A₁to A₃One of which is a single bond and is linked to the fluoranthene group, and the remainder A₁To A₃Each independently represents hydrogen, deuterium, C_1-4Alkyl radical, C_1-4Alkoxy, amino, silyl, cyano, substituted or unsubstituted C containing at least one heteroatom selected from the group consisting of N, O, and S_5-30Heteroaryl, substituted or unsubstituted C_6-30Aryl radicals or the remainder of A₁To A₃And R₁Together with an adjacent aryl radical to form C_6-18A condensed ring aromatic hydrocarbon group:

2. The fluoranthenyl-containing dibenzothiophene compound of claim 1, having the structure of formula (I), when the fluoranthenyl group is bonded to A₁When in position, the fluoranthenyl-containing dibenzothiophene compound of formula (I) is selected from one of the group consisting of:

in the formula, Y₁To Y₄Each independently represents deuterium, C_1-4Alkyl radical, C_1-4Alkoxy, amino, silyl, cyano, substituted or unsubstituted C_6-30Aryl, substituted or unsubstituted C containing at least one heteroatom selected from the group consisting of N, O, and S_5-12A heteroaryl group;

n, p, q are integers selected from 0 to 4; and

m is an integer selected from 0 to 3.

3. The fluoranthenyl-containing dibenzothiophene compound of claim 1, having the structure of formula (I), when the fluoranthenyl group is bonded to A₂When in position, the fluoranthenyl-containing dibenzothiophene compound of formula (I) is selected from one of the group consisting of:

in the formula, Y₁To Y₄Each independently of the otherRepresents deuterium, C_1-4Alkyl radical, C_1-4Alkoxy, amino, silyl, cyano, substituted or unsubstituted C_6-30Aryl, substituted or unsubstituted C containing at least one heteroatom selected from the group consisting of N, O, and S_5-12A heteroaryl group;

n, p, q are integers selected from 0 to 4; and

m is an integer selected from 0 to 3.

4. The fluoranthenyl-containing dibenzothiophene compound of formula (I) according to claim 3, wherein said fluoranthenyl-containing dibenzothiophene compound of formula (I) is represented by formula (I-51):

5. the fluoranthenyl-containing dibenzothiophene compound of claim 1, having the structure of formula (I), when the fluoranthenyl group is bonded to A₃When in position, the fluoranthenyl-containing dibenzothiophene compound of formula (I) is selected from one of the group consisting of:

n, p, q are integers selected from 0 to 4; and

m is an integer selected from 0 to 3.

6. The fluoranthenyl-containing dibenzothiophene compound of claim 1, having the structure of formula (I), wherein X₁And X₂Each independently selected from the group consisting of phenyl, tolyl, pyridyl, and naphthyl.

7. The fluoranthenyl-containing dibenzothiophene compound of formula (I) according to claim 1, wherein said fluoranthenyl-containing dibenzothiophene compound of formula (I) is selected from the group consisting of:

8. the fluoranthenyl-containing dibenzothiophene compound of claim 7, having the structure of formula (I), wherein X₁And X₂Are all phenyl groups.

9. The fluoranthenyl-containing dibenzothiophene compound of formula (I) according to claim 1, wherein said fluoranthenyl-containing dibenzothiophene compound of formula (I) is selected from one of the group consisting of:

10. an organic electroluminescent device comprising:

a cathode;

an anode; and

an organic layer interposed between the cathode and the anode, wherein the organic layer comprises the fluoranthenyl-containing dibenzothiophene compound of claim 1 having the structure of formula (I).

11. The organic electroluminescent device of claim 10, wherein the organic layer is an electron transport layer and has a thickness of 15 nm to 40 nm.

12. The organic electroluminescent device of claim 11, wherein the electron transport layer further comprises an N-type conductivity dopant, the N-type conductivity dopant is greater than 0 wt% to 50 wt%, and the N-type conductivity dopant is lithium quinolate.