阅读说明：本技术 高效非掺杂电致长波红光的芳胺二苯基反式丁烯二腈衍生物 (Arylamine diphenyl trans-butenedionitrile derivative with efficient undoped electroluminescence of long-wave red light ) 是由 张文官 于 2020-07-03 设计创作，主要内容包括：本发明涉及一种高效非掺杂电致长波红光的芳胺二苯基反式丁烯二腈衍生物,属于发光材料技术领域,芳胺二苯基分别为：二(4-(N-(2-螺二芴基)-3,5-二甲苯胺)苯基)、二(4-(N-(4-联苯基)-9,9-二乙基-2-芴胺)苯基)或二(4-(N,N-二(4-联苯基)胺基)苯基)。本发明的芳胺二苯基反式丁烯二腈衍生物,通过大体积、大共轭基团的引入,不仅增强了材料及器件的发光效率,而且使发光波长向长波段红光移动,同时不同基团的引入,可有效地调节了有机电致发光的颜色,另外,这些基团的引入,能减少层间的界面势垒,优化红色非掺杂有机电致发光器件的设计,有效地提高了器件的发光效率。(The invention relates to an arylamine diphenyl trans-butenedionitrile derivative with high efficiency and undoped electroluminescence of long-wave red light, which belongs to the technical field of luminescent materials, wherein arylamine diphenyl comprises the following components in percentage by weight: bis (4- (N- (2-spirobifluorenyl) -3, 5-xylidine) phenyl), bis (4- (N- (4-biphenyl) -9, 9-diethyl-2-fluorenamine) phenyl) or bis (4- (N, N-bis (4-biphenyl) amino) phenyl). The arylamine diphenyl trans-butenedionitrile derivative not only enhances the luminous efficiency of materials and devices, but also enables the luminous wavelength to move to long-wave-band red light by introducing large-volume and large-conjugated groups, and simultaneously can effectively adjust the color of organic electroluminescence by introducing different groups.)

1. The high-efficiency undoped aromatic amine diphenyl trans-butenedionitrile derivative with long-wave red light emission is characterized in that: the arylamine diphenyl groups are respectively as follows: bis (4- (N- (2-spirobifluorenyl) -3, 5-xylidine) phenyl), bis (4- (N- (4-biphenyl) -9, 9-diethyl-2-fluorenamine) phenyl) or bis (4- (N, N-bis (4-biphenyl) amino) phenyl).

2. The arylamine diphenyl trans-butenedionitrile derivative having high efficiency and being undoped with electroluminescent long-wavelength red light according to claim 1, wherein: the high-efficiency undoped aromatic amine diphenyl trans-butene dinitrile derivative with long-wave red light emission is as follows: bis (4- (N- (2-spirobifluorenyl) -3, 5-xylidine) phenyl) fumarodinitrile, bis (4- (N- (4-biphenylyl) -9, 9-diethyl-2-fluoreneamine) phenyl) fumarodinitrile or bis (4- (N, N-bis (4-biphenylyl) amino) phenyl) fumarodinitrile.

3. The preparation process of high efficiency undoped electroluminescent aromatic amine diphenyl trans butene dinitrile derivative includes the following steps: under the protection of inert gas argon, respectively dissolving di (4-bromophenyl) trans-butenedionitrile and secondary amine in an organic solvent, adding a mixed catalyst of inorganic base, organic palladium and organic phosphine, and carrying out mixed reaction to obtain an arylamine diphenyl trans-butenedionitrile derivative; the molar ratio of bis (4-bromophenyl) trans-butenenitrile to the secondary amine is 1:2.1 to 1: 2.4.

4. The preparation method of the arylamine diphenyl trans-butenedionitrile derivative with high efficiency and undoped electroluminescence of the long-wave red light as claimed in claim 3, wherein: the secondary amine is as follows: n- (3, 5-xylyl) -2-spirobifluoreneamine, N- (4-biphenyl) -9, 9-diethyl-2-fluoreneamine or N, N-bis (1-biphenyl) amine; the reaction temperature is 110 ℃ and 130 ℃, and the reaction time is 12-24 hours.

5. The preparation method of the arylamine diphenyl trans-butenedionitrile derivative with high efficiency and undoped electroluminescence of the long-wave red light as claimed in claim 3, wherein: the amount of the organic palladium is 4-12 wt% of the bis (4-bromophenyl) trans-butendinitrile, the amount of the organic phosphine is 12-36 wt% of the bis (4-bromophenyl) trans-butendinitrile, and the amount of the inorganic base is 3-5 times that of the bis (4-bromophenyl) trans-butendinitrile; the organic solvent is toluene or xylene, and the organic palladium is Pd (OAc)₂The organic phosphine is tri-tert-butyl phosphine, and the inorganic base is cesium carbonate.

6. The synthesis intermediates of the arylamine diphenyl trans-butenedionitrile derivative with high efficiency and undoped electroluminescence of long-wave red light are respectively: n- (3, 5-xylyl) -2-spirobifluoreneamine, N- (4-biphenyl) -9, 9-diethyl-2-fluoreneamine and N, N-bis (1-biphenyl) amine.

7. The preparation of the intermediate for synthesizing the arylamine diphenyl trans-butenedionitrile derivative with efficient undoped electroluminescent long-wave red light comprises the following steps: under the protection of argon, dissolving fluorene and substituent group fluorene bromide and primary arylamine in an organic solvent, adding a mixed catalyst of inorganic base, organic palladium and organic phosphine, and carrying out mixing reaction to obtain secondary amine, wherein the molar ratio of the fluorene and substituent group fluorene bromide to the primary arylamine is 1: 1.1-1: 1.4, the use amount of the organic palladium is 0.5-2 wt% of the fluorene and substituent group fluorene bromide, the use amount of the organic phosphine is 2-4 wt% of the fluorene and substituent group fluorene bromide, the use amount of the inorganic base is 1-2 times of the fluorene and substituent group fluorene bromide, the reaction temperature is 80-120 ℃, the reaction time is 12-24 hours, and the catalyst is used for reactionIs a mixture of organic palladium, organic phosphine and inorganic base, the organic palladium is Pd (dba)₂Or Pd (OAc)₂The organic phosphine is (2- (dicyclohexylphosphine) -2',4',6' -tri-isopropyl-1, 1' -biphenyl (Xphos), tri-tert-butylphosphine or 2, 2' -bis (diphenylphosphine) diphenyl ether, the inorganic base is sodium tert-butyl alkoxide, and the organic solvent is toluene or xylene.

8. A luminescent device is prepared by vacuum evaporation, indium tin oxide glass is taken as an anode, lithium fluoride is taken as an electron injection layer, and aluminum is taken as a cathode; the lithium fluoride is an electron injection layer, and sequentially comprises a tri (8-hydroxyquinoline) aluminum layer, a hole blocking layer and a high-efficiency undoped arylamine diphenyl trans-butenedionitrile derivative coating with electroluminescent long-wave red light.

9. The light-emitting device according to claim 8, wherein: the high-efficiency undoped electroluminescent long-wave red light arylamine diphenyl trans-butendinitrile derivative coating is a bis (4- (N- (2-spirobifluorenyl) -3, 5-xylidine) phenyl) trans-butendinitrile coating, a bis (4- (N- (4-biphenyl) -9, 9-diethyl-2-fluorenylamine) phenyl) trans-butendinitrile coating or a bis (4- (N, N-bis (4-biphenyl) amino) phenyl) trans-butendinitrile coating.

10. The light-emitting device according to claim 9, wherein: a hole transport layer N, N '-diphenyl-N, N' - (1-naphthyl) -1,1 '-biphenyl-4, 4' -diamine is also arranged on the high-efficiency undoped electroluminescent longwave red arylamine diphenyl trans-butenedionitrile derivative coating.

Technical Field

The invention relates to a trans-butenedionitrile derivative, in particular to an arylamine diphenyl trans-butenedionitrile derivative which is efficiently undoped with electroluminescent long-wave red light, particularly relates to a trans-butenedionitrile derivative with units of fluorene, spirobifluorene-2, biphenyl and the like, and belongs to the technical field of luminescent materials.

Background

Among RGB three-primary-color organic light emitting materials for full-color display, forgery prevention, and the like, there are few red light emitting materials that can satisfy practical requirements.

The main reasons are as follows: 1. the difference in energy level between the lowest excited state and the ground state of the red light-emitting material is small, and non-radiative deactivation of excited molecules is relatively easy to occur, so that the fluorescence quantum yield of most materials is not high. 2. The red luminescent material mostly has a large pi system or has a strong Charge Transfer (CT) characteristic, the intermolecular distance of the material is very small in high concentration or solid state, the interaction is strong, the non-radiative energy inactivation is increased rapidly, and concentration quenching is shown.

The red luminescent material is often limited to be used in doping organic electroluminescent devices (OLEDs), and can be optimized to have low doping concentration and narrow effective doping range, so that the red luminescent material is difficult to produce on a large scale in practice. Therefore, undoped red light emitting materials are gradually becoming the focus of attention. The first type of undoped red light material, although improving amorphous stability and fluorescence intensity in solid, unbalances hole and electron transport. The second type is a red light-emitting material containing an electron donor-electron acceptor whose fluorescence concentration quenching at solid is suppressed by the structure of the electron donor-electron acceptor in the molecule. In particular, arylamine diphenyl trans-butendinitrile derivatives, such as dianilino spirobifluorene trans-butendinitrile and bis (4- (N- (1-naphthyl) -anilino) phenyl) trans-butendinitrile (1-NPAFN), become an unusual class of non-doped red luminescent materials due to the presence of a non-planar arylamine structure and a trans-butendinitrile core. In the arylamine trans-butene dinitrile, a pair of antiparallel dipoles effectively reduces the close packing between molecules and emits strong red light. A series of red-light dyes (ArPAFN) of D-pi-A-pi-D is obtained by using a strong electron donor (D) fluorene cyclic hydrocarbon, a connecting part of a benzene bridge and a strong electron acceptor (A) as trans-butendinitrile. The red luminescent material prevents solid-state intramolecular rotation and non-radiative relaxation, avoids solid-state (or aggregation state) fluorescence quenching, and simultaneously improves amorphous state stability, film quality and carrier transport performance. Has relatively simple synthesis and is convenient for large-scale preparation. It has the characteristics of higher thermal stability, easier sublimation and purification and good film forming property. Especially at high current densities, the devices show good stability. With the increase of the current density, the luminous efficiency of the LED lamp has small descending trend and stable change.

In the diarylamine of the trans-butenedionitrile benzene bridge, the selection of two diaryl groups has great influence on the luminous efficiency and the luminous wavelength (corresponding to the EL wavelength and the luminous efficiency of the device): one is: one aryl group is a benzene ring, and the other is a fused aromatic ring [ e.g., 1-naphthalene (1-NPAFN), 2-naphthalene (2-NPAFN), phenanthrene, pyrene, etc. ]; the EL (electroluminescence) wavelength is from 620 to 668 nm. 1-naphthyl and phenyl (EL wavelength 634nm, maximum external quantum efficiency 2.4%); 2-naphthyl and phenyl (EL wavelength 666nm, maximum current efficiency LE 1.3 cd/A); phenanthryl and xylyl (EL wavelength 656nm, LE 2.5 cd/A); pyrenyl and xylyl (EL wavelength 668nm, LE 3.4 cd/A). The second type is: one aryl group is a benzene ring, and the other is a red luminescent material of condensed ring fluorene, such as fluorenyl and xylyl, the EL wavelength is longer and reaches 680 nm. The Luminous Efficiency (LE) was further improved to 3.5 cd/A. The three types are: one aryl group is a red light material with a large conjugated structure (such as biphenyl), the other aryl group is a red light material with a large conjugated structure (such as biphenyl) or a fused aromatic ring (such as fluorene, spirobifluorene-2 and the like), and the EL wavelength is long-wave band red light between 680-700 nm. This type has not been reported.

Therefore, how to introduce large-volume and large-conjugated groups (such as biphenyl) or fused aromatic rings (such as fluorene, spirobifluorene-2 and the like) onto the trans-butenedionitrile phenyl bridge simultaneously to obtain a new undoped red luminescent material, the luminescent efficiency of the material and a device is enhanced, and the luminescent wavelength is moved to red light of a longer wavelength band; meanwhile, the introduction of different groups can effectively adjust the color of organic electroluminescence; in addition, the introduction of the groups can reduce the interface potential barrier between layers, optimize the design of a red non-doped organic electroluminescent device and further improve the luminous efficiency of the device, thereby becoming a technical problem which needs to be solved urgently in the technical field.

Disclosure of Invention

The invention aims to provide an arylamine diphenyl trans-butene dinitrile derivative which is high-efficiency undoped with electroluminescent long-wave red light, which can not only enhance the luminous efficiency of materials and devices, but also move the luminous wavelength to the long-wave band red light; different groups are introduced, so that the color of organic electroluminescence can be effectively adjusted; the design of the red non-doped organic electroluminescent device is optimized, the number of layers and the interface potential barrier between layers are reduced, and the luminous efficiency of the device is effectively improved.

The above object of the present invention is achieved by the following technical solutions:

the high-efficiency undoped aromatic amine diphenyl trans-butenedionitrile derivative with long-wave red light emission is characterized in that: the arylamine diphenyl groups are respectively as follows: bis (4- (N- (2-spirobifluorenyl) -3, 5-xylidine) phenyl), bis (4- (N- (4-biphenyl) -9, 9-diethyl-2-fluorenamine) phenyl) or bis (4- (N, N-bis (4-biphenyl) amino) phenyl).

Preferably, the arylamine diphenyl trans-butenedionitrile derivatives which are highly efficient and undoped and emit long-wave red light are respectively as follows: bis (4- (N- (2-spirobifluorenyl) -3, 5-xylidine) phenyl) fumarodinitrile (SFPAFN,3a), bis (4- (N- (4-biphenyl) -9, 9-diethyl-2-fluoreneamine) phenyl) fumaronitrile (BPFAFN,3b), or bis (4- (N, N-bis (4-biphenyl) amino) phenyl) fumaronitrile (BBPAFN,3 c).

Preferably, the specific structure of the arylamine diphenyl trans-butenedionitrile derivative with high efficiency and undoped electroluminescence of long-wave red light is as follows:

the invention also aims to provide a preparation method of the arylamine diphenyl trans-butenedionitrile derivative with high efficiency and undoped electroluminescence of long-wave red light.

The above object of the present invention is achieved by the following technical solutions:

the preparation of high-efficiency undoped aromatic amine diphenyl trans-butenedionitrile derivatives with electroluminescent long-wave red light comprises the following steps: under the protection of inert gas argon, respectively dissolving di (4-bromophenyl) trans-butenenitrile and secondary amine in an organic solvent, adding a mixed catalyst of inorganic base, organic palladium and organic phosphine, and carrying out mixed reaction to obtain an arylamine diphenyl trans-butenenitrile derivative (red light dye series ArPAFN); the molar ratio of bis (4-bromophenyl) trans-butenenitrile to the secondary amine is 1:2.1 to 1: 2.4.

Preferably, the secondary amine is: n- (3, 5-xylyl) -2-spirobifluoreneamine (2a), N- (4-biphenyl) -9, 9-diethyl-2-fluoreneamine (2b), or N, N-bis (1-biphenyl) amine (2 c).

Preferably, the reaction temperature is 110 ℃ and 130 ℃, and the reaction time is 12-24 hours.

Preferably, the amount of the organic palladium is 4 to 12% by weight of the bis (4-bromophenyl) trans-butendinitrile, the amount of the organic phosphine is 12 to 36% by weight of the bis (4-bromophenyl) trans-butendinitrile, and the amount of the inorganic base is 3 to 5 times that of the bis (4-bromophenyl) trans-butendinitrile.

Preferably, the organic solvent is toluene or xylene.

Preferably, the organic palladium is Pd (OAc)₂。

Preferably, the organic phosphine is tri-tert-butylphosphine.

Preferably, the inorganic base is cesium carbonate.

It is a further object of the present invention to provide synthetic intermediates for the above highly efficient undoped aromatic amine diphenyl trans-butenedionitrile derivatives emitting electroluminescent long-wavelength red light.

The above object of the present invention is achieved by the following technical solutions:

the synthesis intermediates of the arylamine diphenyl trans-butenedionitrile derivative with high efficiency and undoped electroluminescence of long-wave red light are respectively: n- (3, 5-xylyl) -2-spirobifluoreneamine (2a), N- (4-biphenyl) -9, 9-diethyl-2-fluoreneamine (2b), and N, N-bis (1-biphenyl) amine (2 c).

The invention further aims to provide the preparation of the synthetic intermediate of the arylamine diphenyl trans-butenedionitrile derivative with high efficiency and undoped electroluminescence wavelength red light.

The above object of the present invention is achieved by the following technical solutions:

the preparation of the intermediate for synthesizing the arylamine diphenyl trans-butenedionitrile derivative with efficient undoped electroluminescent long-wave red light comprises the following steps: under the protection of argon, dissolving fluorene and substituent group fluorene bromide and primary arylamine in an organic solvent, adding a mixed catalyst of inorganic base, organic palladium and organic phosphine, and carrying out mixed reaction to obtain secondary amine (a synthetic intermediate of the arylamine diphenyl trans-butenedionitrile derivative), wherein the molar ratio of the fluorene and substituent group fluorene bromide to the primary arylamine is 1: 1.1-1: 1.4.

Preferably, the amount of the organic palladium is 0.5-2 wt% of the fluorene and the bromide of the substituent fluorene, the amount of the organic phosphine is 2-4 wt% of the fluorene and the bromide of the substituent fluorene, and the amount of the inorganic base is 1-2 times of the fluorene and the bromide of the substituent fluorene.

Preferably, the reaction temperature is 80-120 ℃ and the reaction time is 12-24 hours.

Preferably, the preparation method of the N- (3, 5-xylyl) -2-spirobifluorene amine (2a) is as follows:

preferably, the preparation method of the N- (4-biphenyl) -9, 9-diethyl-2-fluorenamine (2b) comprises the following steps:

preferably, the preparation method of the N, N-bis (1-biphenyl) amine (2c) is as follows:

preferably, the catalyst is a mixture of an organopalladium, an organophosphine and an inorganic base.

Preferably, the organic palladium is Pd (dba)₂Or Pd (OAc)₂。

Preferably, the organic phosphine is (2- (dicyclohexylphosphine) -2',4',6' -tri-isopropyl-1, 1' -biphenyl (Xphos), tri-tert-butylphosphine or 2, 2' -bis (diphenylphosphine) diphenyl ether (bis (2- (diphenylphosphino) -phenyl) ether, DPEphos).

Preferably, the inorganic base is sodium tert-butyl alkoxide.

Preferably, the organic solvent is toluene or xylene.

It is still another object of the present invention to provide a light emitting device that reduces the number of layers and interface barriers between layers and effectively improves the light emitting efficiency of the device.

The above object of the present invention is achieved by the following technical solutions:

a luminescent device is prepared by vacuum evaporation, ITO (indium tin oxide) glass is taken as an anode, lithium fluoride is taken as an electron injection layer, and aluminum is taken as a cathode; the lithium fluoride is an electron injection layer, and is sequentially provided with a tri (8-hydroxyquinoline) aluminum layer, a hole blocking layer (BCP layer) and a high-efficiency undoped arylamine diphenyl trans-butenedionitrile derivative coating with electroluminescent long-wave red light.

Preferably, the aromatic amine diphenyl fumaronitrile derivative coating layer with high efficiency undoped electroluminescent long-wave red light is a bis (4- (N- (2-spirobifluorenyl) -3, 5-xylidine) phenyl) fumaronitrile (SFPAFN,3a) coating layer, a bis (4- (N- (4-biphenylyl) -9, 9-diethyl-2-fluorenylamine) phenyl) fumaronitrile (BPFAFN,3b) coating layer or a bis (4- (N, N-bis (4-biphenylyl) amino) phenyl) fumaronitrile (BBPAFN,3c) coating layer.

Preferably, the BPFAFN layer is 40nm thick; AlQ₃The thickness of the aluminum layer of the tris (8-hydroxyquinoline) is 30 nm; the BCP layer is 4, 7-diphenyl-2, 9-dimethyl phenanthroline layer with the thickness of 10 nm.

Preferably, a hole transport layer NPB layer (N, N '-diphenyl-N, N' - (1-naphthyl) -1,1 '-biphenyl-4, 4' -diamine layer) is further provided on the BPFAFN (3b) layer.

Has the advantages that:

the red non-doped luminescent material (ArPAFN) of the electron donor arylamine, the benzene bridge and the electron acceptor trans-butenedionitrile prepared by the invention has great influence on the luminous efficiency and the luminous wavelength due to the selection of two diaryl groups in the diaryl amine of the trans-butenedionitrile benzene bridge; in order to obtain the long-wave-band red light with EL wavelength between 680-700nm, units of fluorene, spirobifluorene-2, biphenyl and the like with large volume and large conjugated groups are introduced into trans-butene dinitrile, so that the luminous efficiency of materials and devices is enhanced, the luminous wavelength moves to the long-wave-band red light, and the introduction of different groups can effectively adjust the color of organic electroluminescence, optimize the design of a red non-doped organic electroluminescent device, reduce the number of layers and the interface barrier between layers and effectively improve the luminous efficiency of the devices.

The invention introduces large-volume and large-conjugated groups (such as biphenyl) or fused aromatic rings (such as fluorene, spirobifluorene-2 and the like) to the trans-butenedionitrile benzene bridge, thereby not only enhancing the luminous efficiency of materials and devices, but also moving the luminous wavelength to the red light of a long wave band, and simultaneously, the introduction of different groups can effectively adjust the color of organic electroluminescence.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments, but the present invention is not meant to be limited to the scope of the present invention.

Drawings

FIG. 1 is a solid film fluorescence spectrum of SFPAFN (3a), BPFAFN (3b) and BBPAFN (3c) which were the products prepared in examples 1 to 3 of the present invention.

FIG. 2 is an EL emission spectrum of BPFAFN (3b) prepared in example 1 of the present invention in the devices of practical examples 1-4.

FIG. 3 is a table showing emission wavelengths and color coordinates of BPFAFN (3b) prepared in example 1 of the present invention in the devices of practical examples 1-4.

Fig. 4 is a schematic diagram of a device structure of BPFAFN (3b) prepared in example 1 of the present invention in application example 1.

Fig. 5 is a schematic diagram of a device structure of BPFAFN (3b) prepared in example 1 of the present invention in application example 2.

Fig. 6 is a schematic diagram of a device structure of BPFAFN (3b) prepared in example 1 of the present invention in application example 3.

Fig. 7 is a schematic diagram of a device structure of BPFAFN (3b) prepared in example 1 of the present invention in application example 4.

Detailed Description

Unless otherwise indicated, the starting materials used in the embodiments of the present invention are commercially available general-purpose materials, and the equipment and methods used are those commonly used in the art.