Disclosure of Invention
In order to solve the technical problems, the invention provides a boron-nitrogen compound, an OLED (organic light emitting diode) with the boron-nitrogen compound and a display or lighting device. The boron nitrogen compound can improve the luminous efficiency and the thermal stability and is easy to modify the molecular structure by collocating the tetrahydronaphthalene limiting group substituted by the di-tert-butylphenyl and the methyl with the mother nucleus.
The invention provides a boron nitrogen compound, which is realized by the following technical scheme:
A boron nitride compound having a structure represented by the following formula (I):
;
In the formula (I), X is O, S, se atoms, R is selected from deuterated or non-deuterated C1-C20 alkyl, substituted or non-substituted phenyl, substituted or non-substituted tetrahydronaphthyl, and when containing substituent groups, the substituent groups are selected from hydrogen, deuterium and C1-C20 alkyl;
r1-R2 is independently selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C5-C36 heteroaryl, when R1-R2 contains substituents selected from any one or more of C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl, and R1-R2 is at least one selected fromOr (b)Wherein Ra-Rl are each independently selected from hydrogen, deuterium, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl, R1-R2 can be attached to the N atom through any of the Ra-Rl sites;
R3、R4 is independently selected from hydrogen, C1-C20 alkyl, C3-C20 cycloalkyl, R3、R4 represents a polysubstituted group, which may be unsubstituted, monosubstituted, or polysubstituted, in which case the substituents may be identical or different from each other, and the substituents may be linked to each other to form a fused ring.
Preferably, each R1-R2 is independently selected from the group consisting of substituted or unsubstituted biphenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted tert-butylphenyl, and substituted or unsubstituted benzothiophenyl.
More preferably, each R1-R2 is independently selected from any one of the following structures:
each Ra-Rl is independently selected from one or more of hydrogen, deuterium, tertiary butyl, phenyl and di-tertiary butyl phenyl.
More preferably, when one of R1-R2 is selected fromWhen the other is selected from any one of the following structures, wherein "#" represents a linking site, ph represents phenyl, tBu represents tert-butyl:
。
Preferably, each R3、R4 is independently selected from fused tetramethylcyclohexenyl, t-butyl, or phenyl, more preferably, at least one of R3、R4 is selected from fused tetramethylcyclohexenyl.
Preferably, R is independently selected from deuterated or non-deuterated tertiary butyl, methyl-substituted tetrahydronaphthyl, substituted or unsubstituted phenyl, and when substituted, the substituents are hydrogen, deuterium, methyl.
According to one or more embodiments, the present invention provides a boron nitride compound selected from any one of the chemical structures shown below, ph represents phenyl, tBu represents tert-butyl:
。
The invention also provides application of the boron-nitrogen compound in an organic electroluminescent device.
The invention also provides an organic electroluminescent device, which comprises:
a substrate layer;
A first electrode over the substrate;
an organic light emitting functional layer over the first electrode;
a second electrode over the organic light emitting functional layer;
The organic light-emitting functional layer contains a boron-nitrogen compound as described above. Preferably, the organic light-emitting functional layer comprises a light-emitting layer, and the light-emitting layer comprises the boron-nitrogen compound.
The invention also provides a composition comprising a boron nitride compound according to formula (I).
The present invention also provides a formulation comprising a boron nitrogen compound of the structure shown in formula (I) above or a composition as described above and at least one solvent. The solvent is not particularly limited, and for example, an unsaturated hydrocarbon solvent such as toluene, xylene, mesitylene, tetrahydronaphthalene, decalin, bicyclohexane, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, a halogenated saturated hydrocarbon solvent such as carbon tetrachloride, chloroform, methylene chloride, dichloroethane, chlorobutane, bromobutane, chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane, bromocyclohexane, a halogenated unsaturated hydrocarbon solvent such as chlorobenzene, dichlorobenzene, trichlorobenzene, an ether solvent such as tetrahydrofuran, tetrahydropyran, an ester solvent such as an alkyl benzoate, and the like, which are known to those skilled in the art, can be used.
The organic electroluminescent device of the present invention can be used in an OLED lighting or display device. Preferably, the organic electroluminescent device prepared by the invention is used in the fields of smart phones, tablet computers, intelligent wearable equipment, televisions, VR, micro-display and automobile central control screens or automobile tail lights.
The invention also provides a display or lighting device comprising one or more of the organic electroluminescent devices as described above.
In summary, compared with the prior art, the invention has the following beneficial effects:
the boron nitride compound has good stability and film forming performance through the collocation of the di-tert-butylphenyl and methyl substituted tetrahydronaphthalene defining groups and the mother nucleus, and can effectively lead the organic light-emitting device to have lower driving voltage and maintain the stability of the voltage after being prepared into the organic light-emitting device, improve the luminous efficiency and ensure the service life of the device to be better.
Detailed Description
The following description of embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is shown, however, only some, but not all embodiments of the invention are shown. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to fall within the scope of the present invention.
The term "alkyl" refers to and includes straight and branched chain alkyl groups. Preferred alkyl groups are those containing 1 to 20 carbon atoms and include methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-dimethylpropyl, 1, 2-dimethylpropyl, 2-dimethylpropyl, and the like. In addition, alkyl groups may be optionally substituted.
The term "cycloalkyl" refers to and includes monocyclic, polycyclic, and spiroalkyl groups. Preferred cycloalkyl groups are cycloalkyl groups having 3 to 20 ring carbon atoms, more preferred cycloalkyl groups are cycloalkyl groups having 3 to 12 ring carbon atoms, especially preferred cycloalkyl groups having 3 to 6 ring carbon atoms, and include cyclopropyl, cyclopentyl, cyclohexyl, bicyclo [3.1.1] heptyl, spiro [4.5] decyl, spiro [5.5] undecyl, adamantyl, and the like. In addition, cycloalkyl groups may be optionally substituted.
The term "aryl" refers to and includes monocyclic aromatic hydrocarbon groups and polycyclic aromatic ring systems. The polycyclic ring may have two or more rings in common in which two carbons are two adjoining rings (the rings being "fused"), wherein at least one of the rings is an aromatic hydrocarbon group, e.g., the other rings may be cycloalkyl, cycloalkenyl, aryl, heterocyclic, and/or heteroaryl. Preferred aryl groups are those containing six to thirty carbon atoms, more preferably six to twelve carbon atoms. Particularly preferred are aryl groups having six carbons, ten carbons or twelve carbons. Suitable aryl groups include phenyl, biphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, perylene and azulene, with phenyl, biphenyl, triphenylene, fluorene and naphthalene being preferred. In addition, aryl groups may be optionally substituted.
The heteroaryl refers to a generic term for groups in which one or more of the aromatic nucleus carbons in the aryl group are replaced by heteroatoms including, but not limited to, oxygen, sulfur, silicon or nitrogen atoms, and may be a monocyclic heteroaryl or a fused ring heteroaryl, and may be a heteroaryl having 5 to 36 carbon atoms, preferably 6 to 20 carbon atoms. Examples may include, but are not limited to, pyridyl, pyrrolyl, pyridyl, thienyl, furyl, indolyl, quinolinyl, isoquinolinyl, benzothienyl, benzofuranyl, dibenzofuranyl, dibenzothienyl, carbazolyl, and the like.
Throughout this specification, unless explicitly stated to the contrary, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of other elements but not the exclusion of any other element. Furthermore, it will be understood that throughout the specification, when an element such as a layer, film, region or substrate is referred to as being "on" or "over" another element, it can be "directly on" the other element or intervening elements may also be present. In addition, "above" or "above" means above the target portion, and not necessarily above in the direction of gravity.
An object of the present invention is to provide an organic electroluminescent device comprising a substrate layer, a first electrode on the substrate, an organic light emitting functional layer on the first electrode, a second electrode on the organic light emitting functional layer, the organic light emitting functional layer comprising a light emitting layer havingOr (b)Boron nitrogen compounds of the structure.
In one embodiment of the present invention, the light emitting layer in an organic electroluminescent (OLED) device comprises one or more of the compounds represented by the general formula (I) as described above as a light emitting doping material.
In a preferred embodiment of the present invention, there is provided an OLED comprising a substrate, an anode, a cathode, an organic light-emitting functional layer, wherein the organic light-emitting functional layer may comprise a light-emitting layer, a hole-transporting layer, a hole-injecting layer, an electron-transporting layer, an electron-injecting layer, etc., and may also comprise only the light-emitting layer and one or more other layers, wherein the light-emitting layer comprises a light-emitting doping material composed of one or more of the compounds represented by the above general formula (I). Optionally, a cover layer, protective layer and/or encapsulation layer is also provided over the organic light-emitting functional layer.
The substrate of the present invention may be any substrate used in a typical organic light emitting device. The flexible PI film can be a glass or transparent plastic substrate, a substrate made of an opaque material such as silicon or stainless steel, or a flexible PI film. Different substrates have different mechanical strength, thermal stability, transparency, surface smoothness and waterproofness, and the use direction is different according to the different properties of the substrates.
As the material of the hole injection layer, the hole transport layer, and the electron injection layer, any material can be selected from known materials for use in an OLED device.
As a host material capable of generating blue fluorescence, green fluorescence, and blue-green fluorescence, it is necessary to have not only extremely high fluorescence quantum emission efficiency but also an appropriate energy level, and to be able to efficiently emit light in accordance with excitation energy of a guest material.
The present invention will be specifically described with reference to the following examples. All starting materials and solvents were commercially available unless specified, and the solvents were used as such and were not further processed.
Examples
EXAMPLE 1 Synthesis of Compound 001
The synthetic route is as follows:
;
1) Compound 001-1 (1 mmoL) and compound 001-2 (1 mmoL) were dissolved in 50 mL toluene solution. Sodium tert-butoxide (2 mmoL), palladium acetate (0.05 mmoL), tri-tert-butylphosphine tetrafluoroborate (0.5. 0.5 mmoL) were added under nitrogen atmosphere. The reaction system was refluxed for 72 hours and then cooled to room temperature. The solvent was removed by rotary evaporation and the residue was extracted with dichloromethane (3×100 mL). The organic phase is washed with water and dried over sodium sulfate. Removing solvent by vacuum distillation, separating and purifying the crude product with silica gel chromatographic column, eluting with eluent (dichloromethane: petroleum ether) =1:4, and intermediate product 001-3;
2) Intermediate 001-3 (1 mmoL) and compound 001-4 (1 mmoL) were dissolved in 50mL toluene solution. Sodium tert-butoxide (2 mmoL), palladium acetate (0.05 mmoL), tri-tert-butylphosphine tetrafluoroborate (0.5. 0.5 mmoL) were added under nitrogen atmosphere. The reaction system was refluxed for 72 hours and then cooled to room temperature. The solvent was removed by rotary evaporation and the residue was extracted with dichloromethane (3×100 mL). The organic phase is washed with water and dried over sodium sulfate. Removing solvent by vacuum distillation, separating and purifying the crude product with silica gel chromatographic column, eluting with eluent (dichloromethane: petroleum ether) =1:4, and intermediate product 001-5;
3) Intermediate 001-5 (1 mmoL) and compound 001-6 (1 mmoL) were dissolved in 50mL toluene solution. Sodium tert-butoxide (2 mmoL), palladium acetate (0.05 mmoL), tri-tert-butylphosphine tetrafluoroborate (0.5. 0.5 mmoL) were added under nitrogen atmosphere. The reaction system was refluxed for 72 hours and then cooled to room temperature. The solvent was removed by rotary evaporation and the residue was extracted with dichloromethane (3×100 mL). The organic phase is washed with water and dried over sodium sulfate. Removing solvent by vacuum distillation, separating and purifying the crude product with silica gel chromatographic column, eluting with eluent (dichloromethane: petroleum ether) =1:4, and intermediate product 001-7;
4) Intermediate 001-7 (1 mmoL) and compound 001-8 (1 mmoL) were dissolved in 50mL toluene solution. Sodium tert-butoxide (2 mmoL), palladium acetate (0.05 mmoL), tri-tert-butylphosphine tetrafluoroborate (0.5. 0.5 mmoL) were added under nitrogen atmosphere. The reaction system was refluxed for 72 hours and then cooled to room temperature. The solvent was removed by rotary evaporation and the residue was extracted with dichloromethane (3×100 mL). The organic phase is washed with water and dried over sodium sulfate. Removing solvent by vacuum distillation, separating and purifying the crude product with silica gel chromatographic column, eluting with eluent (dichloromethane: petroleum ether) =1:4, and intermediate product 001-9;
5) Intermediate 001-9 (1 mmoL) was dissolved in 60 mL anhydrous tert-butylbenzene. The reaction was cooled to-78 ℃ and BuLi (1 mL,2 mmoL,2M in hexane) was slowly added. After 4 hours of reaction at-78 ℃, BBr (3247 mg,1 mmoL) was slowly added. After 1 hour of reaction at-50 ℃, the temperature was raised to room temperature, then N, N-diisopropylethylamine (387 mg,3 mmoL) was added, followed by heating to 120℃for reaction for 12 hours. After cooling to room temperature, 5 mL aqueous sodium acetate (1M) was added. The solvent was removed by rotary evaporation and the residue was extracted with dichloromethane (3×100 mL). The organic phase is washed with water and dried over sodium sulfate. The solvent was removed by distillation under reduced pressure, and the crude product was purified by silica gel column chromatography with eluent (dichloromethane: petroleum ether) =1:8 to give final product 001. The structure of the target product 001 was tested by LC-MS (m/z) (m+), theoretical value 1054.73 and test value 1055.25 by LC-MS (m/z) (m+), ms+ analysis.
EXAMPLE 2 Synthesis of Compound 015
Referring to the synthesis procedure and reaction conditions of example 1, compound 015 was synthesized by liquid chromatography-mass spectrometry analysis to give LC-MS (m/z) (m+).
EXAMPLE 3 Synthesis of Compound 021
Referring to the synthesis procedure and reaction conditions of example 1, compound 021 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 4 Synthesis of Compound 049
Referring to the synthesis procedure and reaction conditions of example 1, compound 049 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 5 Synthesis of Compound 051
Referring to the synthesis procedure and reaction conditions of example 1, compound 051 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+):theoretical 1079.73 and test 1080.27.
EXAMPLE 6 Synthesis of Compound 053
Referring to the synthesis procedure and reaction conditions of example 1, compound 053 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 7 Synthesis of Compound 072
Referring to the synthesis procedure and reaction conditions of example 1, compound 072 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 8 Synthesis of Compound 081
Referring to the synthesis procedure and reaction conditions of example 1, compound 081 was synthesized, and LC-MS (m/z) (μm+), theoretical 1072.68 and test 1073.14 were obtained by liquid chromatography-mass spectrometry analysis.
EXAMPLE 9 Synthesis of Compound 088
Referring to the synthesis procedure and reaction conditions of example 1, compound 088 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 10 Synthesis of Compound 089
Referring to the synthesis procedure and reaction conditions of example 1, compound 089 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 11 Synthesis of Compound 090
Referring to the synthesis procedure and reaction conditions of example 1, compound 090 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 12 Synthesis of Compound 092
Referring to the synthesis procedure and reaction conditions of example 1, compound 092 was synthesized by liquid chromatography-mass spectrometry analysis to give LC-MS (m/z) (m+).
EXAMPLE 13 Synthesis of Compound 098
Referring to the synthesis procedure and reaction conditions of example 1, compound 098 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 14 Synthesis of Compound 099
Referring to the synthesis procedure and reaction conditions of example 1, compound 099 was synthesized by liquid chromatography-mass spectrometry analysis to give LC-MS (m/z) (m+).
EXAMPLE 15 Synthesis of Compound 102
Referring to the synthesis procedure and reaction conditions of example 1, compound 102 was synthesized by liquid chromatography-mass spectrometry analysis to give LC-MS (m/z) (m+).
EXAMPLE 16 Synthesis of Compound 107
Referring to the synthesis procedure and reaction conditions of example 1, compound 107 was synthesized by liquid chromatography-mass spectrometry analysis to give LC-MS (m/z) (m+).
EXAMPLE 17 Synthesis of Compound 116
Referring to the synthesis procedure and reaction conditions of example 1, compound 116 was synthesized by liquid chromatography-mass spectrometry analysis to give LC-MS (m/z) (m+).
EXAMPLE 18 Synthesis of Compound 121
Referring to the synthesis procedure and reaction conditions of example 1, compound 121 was synthesized by liquid chromatography-mass spectrometry analysis to give LC-MS (m/z) (m+).
EXAMPLE 19 Synthesis of Compound 124
Referring to the synthesis procedure and reaction conditions of example 1, compound 124 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 20 Synthesis of Compound 130
Referring to the synthesis procedure and reaction conditions of example 1, compound 130 was synthesized by liquid chromatography-mass spectrometry analysis to give LC-MS (m/z) (m+).
EXAMPLE 21 Synthesis of Compound 140
Referring to the synthesis procedure and reaction conditions of example 1, compound 140 was synthesized by liquid chromatography-mass spectrometry analysis to give LC-MS (m/z) (m+).
EXAMPLE 22 Synthesis of Compound 148
Referring to the synthesis procedure and reaction conditions of example 1, compound 148 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 23 Synthesis of Compound 159
Referring to the synthesis procedure and reaction conditions of example 1, compound 159 was synthesized and analyzed by liquid chromatography-mass spectrometry to give LC-MS (m/z) (m+).
EXAMPLE 24 Synthesis of Compound 162
Referring to the synthesis procedure and reaction conditions of example 1, compound 162 was synthesized by liquid chromatography-mass spectrometry analysis to give LC-MS (m/z) (m+).
The following examples of applications of the boron nitrogen compounds of the present invention in OLED devices are given to further illustrate the beneficial effects of the compounds of the present invention. The materials used in the examples were purchased commercially or synthesized by themselves.
Manufacturing of OLED device:
As a reference preparation mode of an embodiment of a device, the invention comprises the steps of evaporating 50-500nm of ITO/Ag/ITO on an alkali-free glass substrate as an anode, evaporating a hole injection layer (5-20 nm), a hole transmission layer (50-150 nm), a light-emitting auxiliary layer (5-120 nm), a light-emitting layer (20-50 nm), a hole blocking layer (5-20 nm), an electron transmission layer (20-80 nm) and an electron injection layer (1-10 nm) on the anode, evaporating Mg and Ag (weight ratio of 1:9,100-150 nm) to form a semitransparent cathode, and evaporating a coating compound. And finally, encapsulating the light-emitting device by using an epoxy resin adhesive in a nitrogen atmosphere.
In a preferred embodiment, the OLED device provided by the invention has the structure that an alkali-free glass substrate is firstly washed by an ultrasonic cleaner and isopropanol for 15 minutes, and then is subjected to UV ozone washing treatment in air for 30 minutes. The treated substrate was vapor-deposited with ITO/Ag/ITO 100nm as an anode by vacuum vapor deposition, then a hole injection layer (HI: PD,10nm, 2%), a hole transport layer (HT, 130 nm), a light emission auxiliary layer (BP, 5 nm), a blue light emitting layer (host material: dopant material-BH-1: compound 001 (weight ratio 98:2,30 nm)), a hole blocking layer (HBL, 5 nm), an electron transport layer (ET: lig-1:1,30 nm), and an electron injection layer (Yb, 1 nm) were sequentially stacked and vapor-deposited, and then Mg and Ag (weight ratio 1:9,130 nm) were co-vapor-deposited to form a semitransparent cathode, and then a compound CPL (65 nm) was vapor-deposited as a capping layer. Finally, the light-emitting device was encapsulated with an epoxy resin adhesive under a nitrogen atmosphere, which was designated as application example 1. The molecular structural formula of the relevant material is shown below (particularly preferably selected from the following structures, but does not represent the present invention limited to the following structures):
Application examples 2-24 and comparative example 1 were prepared with reference to the method provided in application example 1 above, except that the compounds listed in table 1 were used as doping materials instead of the compound 001 in application example 1, respectively. The doping materials in comparative example 1 are as follows:。
performance evaluation of OLED device:
The OLED device is tested for current at different voltages by using a Keithley 2365A digital nanovoltmeter, then the current is divided by the light emitting area to obtain the current density of the OLED device at the different voltages, the brightness and the radiant energy density of the OLED device at the different voltages are tested by using a Konicaminolta CS-2000 spectral radiant brightness meter, the operating voltage Volt and the current efficiency (cd/A) at the same current density (10 mA/cm2) are obtained according to the current density and the brightness of the OLED device at the different voltages, BI=E/CIEy refers to Blue Index in Blue light and is also a parameter for measuring the luminous efficiency of the Blue light, E refers to the current efficiency, and CIEy refers to a ordinate color point obtained according to the emission half-peak width wavelength band of the device into CIE1930 software. The test data are shown in table 1.
Table 1 organic electroluminescent device and electronic luminescence characteristics table
As can be seen from table 1, application examples 1 to 24 have lower operating voltage, higher BI light emitting efficiency and longer service life compared to comparative example 1. The improvement on the performance of each application example is based on the collocation of the limiting groups such as di-tert-butylphenyl, methyl substituted tetrahydronaphthalene and the like introduced by the invention and the boron-nitrogen core structure, so that the boron-nitrogen compound material has better luminous efficiency, and the compatibility of the doping material in the invention is good, so that the blue light luminous layer can better realize the balance of electron and hole transmission and exciton conversion rate, reduce the power consumption of the device and prolong the service life.
The present embodiment is only for explanation of the present invention and is not to be construed as limiting the present invention, and modifications to the present embodiment, which may not creatively contribute to the present invention as required by those skilled in the art after reading the present specification, are all protected by patent laws within the scope of claims of the present invention.