JP6945841B2 - Near-infrared absorption squarylium derivatives and organic electronic devices containing them - Google Patents

Description

The present invention relates to a novel near-infrared absorbing squarylium derivative and an organic electronic device containing the same.

In recent years, organic electronic devices such as organic solar cells have the characteristics of being lightweight and freely bendable, and are also advantageous in terms of manufacturing cost. Therefore, they have entered the stage of commercialization and market launch in place of silicon-based inorganic solar cells. It's getting better. There are two types of organic solar cell devices, a vapor deposition type and a coating type. In particular, a coating type organic thin film solar cell has a lower manufacturing cost than a vapor deposition type organic thin film solar cell and is suitable for mass production. However, the photoelectric energy conversion efficiency of organic thin-film solar cells is about 10%, and there is still room for improvement in terms of efficiency and reliability compared to silicon-based inorganic solar cells, and active research and development is being carried out. It has been.

Sunlight has 50% or more of its energy in the near-infrared / infrared region having a wavelength longer than 650 nm. Therefore, in order to dramatically improve the photoelectric conversion efficiency, it is essential to efficiently absorb this wavelength region and extract it as electrical energy. Near-infrared absorption materials with a high molar extinction coefficient can be applied to transparent solar cells, sensors, etc., but both organic and inorganic are extremely few. So far, organic solar cell devices have been used as donor materials and acceptor materials. Is manufactured in combination with. Fullerene derivatives generally used as acceptor materials have the advantages of slow electron transfer and high symmetry, but they do not have strong absorption near the near-infrared region, which improves the efficiency of organic solar cell devices. For this, the development of donor materials with absorption in the long wavelength region is very important. In addition, the relationship between the energy level of the donor material and the acceptor material is important for improving the efficiency of the organic solar cell device. In order to transfer charge from excitons generated by absorbing sunlight in the donor material to the acceptor material, the lowest unoccupied molecular orbital (LUMO) level of the donor material is generally the LUMO of the acceptor material. It is said that it is preferable that the level is 0.3 eV or more shallower than the level. In a coating type organic thin film solar cell, methyl phenyl C71 butyrate (PC ₇₁ BM), which has high solubility, is usually used as an acceptor material. Since _{the LUMO level of PC 71} BM is 4.0 eV, the LUMO level of about 3.7 eV is required for the donor material.

The donor material used in coated organic thin-film solar cells, of course, needs to be well soluble in solvents. There are roughly two known donor materials, a high molecular type and a low molecular type. The efficiency of polymer-type materials has improved to about 8%, but polymer-type materials are difficult to purify, difficult to purify, and the characteristics change greatly between production lots to maintain quality. difficult. On the other hand, the low molecular weight material has features such as no molecular weight distribution, easy purification and high reliability, or the quality does not change between production lots and the energy conversion efficiency is not affected by lots. However, the mobility of low molecular weight materials is as ^{low as about 10-5} cm ² / Vs at present, and the energy conversion efficiency is only 7% or less. In addition, among low molecular weight materials, materials that have achieved high efficiency generally have low solubility, and when producing a coating type organic thin-film solar cell, halogen-based materials such as orthodichlorobenzene (ODCB) and chloroform are used. Solvents must be used, which poses an environmental problem. Therefore, in order to improve the performance and practicality of coated organic thin-film solar cells, a new low-molecular-weight material that has near-infrared light absorption capacity and high mobility and is highly soluble in non-halogen solvents, etc. Development is required.

The squarylium derivative shows high solubility in non-halogen solvents, has strong absorption in the near infrared region, has slow back electron transfer, and has a structure with high symmetry, so it can be used as a donor material. Research and development have been carried out, and many have already been reported (Non-Patent Documents 1 to 3).

G. Chen, H. Sasabe, Y. Sasaki, H. Katagiri, X.F. Wang, T. Sano, Z. Hong, Y. Yang, and J. Kido, “Chem. Mater.” 2014, 26, 1356-1364. Sasaki, Sasabe, Hong, Yang, and Kido "The 62nd Annual Meeting of the Society of Polymer Science, Japan", 1J28 (2013) H. Sasabe, T. Igarashi, Y. Sasaki. G. Chen, Z. Hong, and J. Kido, “RSC Advances” 2014,4, 42804-42807.

The squarylium derivative can be synthesized relatively easily in high yield by a dehydration condensation reaction, is environmentally friendly, and various substituents can be introduced. Among the squarylium derivatives, SQ-1, YSQ-8, and SQ-BP have PCE (power conversion efficiency) of 4.0% and 3.8%, respectively, in BHJ (bulk heterojunction) type devices by coating film formation. It has achieved 4.8%. The energy conversion efficiencies of these derivatives are improved compared to their predecessors, but still low. In addition, organic solar cell devices using these squarylium derivatives have _{higher V OC} (open circuit voltage) and J _SC (short circuit current density) values than other materials, but have lower FF (curve factor). There was a problem.

Among the derivatives, YSQ-8 and SQ-BP are molecules designed to have energy levels suitable for combining _{PC 70 BM as an acceptor material.} Among them, SQ-BP has a symmetrical molecular structure, the yield of synthesis is 80% or more, and the PCE is relatively high at 4.8%.

Therefore, in the present invention, in order to provide a novel squarylium derivative useful for providing a highly efficient organic electronic device, we focus on SQ-BP, improve its terminal substituent, and lengthen the absorption wavelength. The problems are to improve the mobility in the thin film state without changing the energy level, and further improve the FF to improve the energy conversion efficiency. Another object of the present invention is to provide a donor material made of the obtained squarylium derivative and an organic electronic device using the donor material.

一般式（１）中、Ａｒ¹及びＡｒ ⁴ は、それぞれ独立に芳香族置換基を表し、Ａｒ²は一般式（２）で表される置換基を表し、Ａｒ ³ は一般式（３）で表される置換基を表し、該一般式（１）〜（３）中、Ｒ¹〜Ｒ³²は、それぞれ独立に水素原子、脂肪族置換基又は芳香族置換基を表す。
本発明の有機電子デバイスは、上記スクアリリウム誘導体を含む。 The present invention comprises the following matters.
The squarylium derivative of the present invention is represented by the following general formula (1).

In the general formula (1), Ar ¹ and Ar ⁴ each independently represent an aromatic substituent, Ar ² represents a substituent represented by the general formula (2), and Ar ³ is represented by the general formula (3). Representing the represented substituents, in the general formulas (1) to (3), R ^{1 to} R ³² independently represent a hydrogen atom, an aliphatic substituent or an aromatic substituent, respectively.
The organic electronic device of the present invention contains the above squarylium derivative.

The squarylium derivative of the present invention has a strong absorption band at 825 nm in the solution state and 900 to 1000 nm in the solid thin film state, and is strongly absorbed on the long wavelength side by about 200 nm in the solution state as compared with the conventional squarylium derivative (absorption wavelength 650 nm). It turns out that it has. By using such a squarylium derivative as a near-infrared absorbing material, it is possible to realize a transparent solar cell or sensor that does not absorb visible light.
Further, the squarylium derivative can be easily synthesized by dehydration condensation, easily dissolved in a halogen-based solvent, and a good thin film can be formed by a solution coating method.

FIG. 1 shows the measurement result of the spectrum of EI-MASS of TSQ-1. FIG. 2 shows ^{the measurement results of the 1} H-NMR spectrum of TSQ-1 (low magnetic field side (a), high magnetic field side (b)). FIG. 3A shows the TGA measurement result of TSQ-1, and FIG. 3B shows the DSC measurement result of TSQ-1. FIG. 4 (a) shows the UV-vis absorption spectrum of the chloroform solution of TSQ-1, FIG. 4 (b) shows the UV-vis absorption spectrum of the TSQ-1 monomembrane, and FIG. 4 (c) shows the TSQ-1. / PC ₇₁ Shows the UV-vis absorption spectrum of the BM mixed film. FIG. 5 shows the CV measurement result of TSQ-1. FIG. 6A shows a photograph of the TSQ-1 single film, and FIG. 6B shows a photograph of the TSQ-1 / PC ₇₁ BM mixed film. FIG. 7 is a schematic cross-sectional view schematically showing the structure of the organic solar cell device.

一般式（１）中、Ａｒ¹及びＡｒ³は、それぞれ独立に芳香族置換基を表し、Ａｒ²は一般式（２）で表される置換基を表し、Ａｒ⁴は一般式（３）で表される置換基を表し、該一般式（１）〜（３）中、Ｒ¹〜Ｒ³²は、それぞれ独立に水素原子、脂肪族置換基又は芳香族置換基を表す。 Hereinafter, the squarylium derivative of the present invention will be described in detail.
[Squarylium derivative]
The squarylium derivative of the present invention is represented by the following general formula (1).

In the general formula (1), Ar ¹ and Ar ³ each independently represent an aromatic substituent, Ar ² represents a substituent represented by the general formula (2), and Ar ⁴ is represented by the general formula (3). Representing the represented substituents, in the general formulas (1) to (3), R ^{1 to} R ³² independently represent a hydrogen atom, an aliphatic substituent or an aromatic substituent, respectively.

In the above general formula (1), Ar ¹ and Ar ³ are independently aromatic substituents. The aromatic substituent may be an aromatic hydrocarbon group, or may contain a nitrogen atom, an oxygen atom, a sulfur atom, or the like as a part of the aromatic hydrocarbon group.
The aromatic hydrocarbon group may be a monocyclic aryl group or a polycyclic (condensed ring) aromatic hydrocarbon group, and a part of hydrogen atoms on the aromatic ring in the aromatic hydrocarbon group is, for example, methyl. It may be substituted with a group, an isopropyl group, an isobutyl group or the like.
Examples of the group containing a nitrogen atom, an oxygen atom, a sulfur atom or the like as a part of the aromatic hydrocarbon group include a diphenylaminophenyl group, an ether group, a thioether group, a furanyl group, a thiophenyl group, a benzofuranyl group and a benzothiophenyl group. Examples include a group, a dibenzofuranyl group, a dibenzothiophenyl group and the like.
The aromatic substituent preferably has 6 to 50 carbon atoms. Examples of the aromatic substituent having 6 to 50 carbon atoms include a phenyl group, a biphenyl group, a naphthyl group, a triphenylenyl group, a terphenyl group, a quarterphenyl group, anthrasenyl, and a 9,9'-spirobifluorenyl group. Examples thereof include a diphenylaminophenyl group and a 9,9'-dimethylfluorenyl group. Of these, a phenyl group, a triphenylenyl group, a naphthyl group, a biphenyl group, a terphenyl group, a quarterphenyl group, a 9,9'-spirobifluorenyl group, a diphenylaminophenyl group, and a 9,9'-dimethylfluore. Phenyl group and the like are more preferable, and phenyl group, 2-triphenylenyl group, 2-naphthyl group, biphenyl-4-yl group, 4- (diphenylamino) phenyl group, 2- (9,9'-spirobifluorenyl). Groups and 3- (9,9'-dimethylfluorenyl) groups are particularly preferred.

The aliphatic substituent is a linear or branched aliphatic hydrocarbon group having 1 to 50 carbon atoms, and is preferably a branched aliphatic hydrocarbon group having 4 to 30 carbon atoms.
Examples of the branched aliphatic hydrocarbon group having 4 to 30 carbon atoms include a t-butyl group, an isobutyl group, a 2-ethylhexyl group, a 2-ethyloctyl group, a 2-hexyldecanyl group and a 2-octyldodecanyl group. Examples include a group, a 2-decyltetradecanyl group and the like. Of these, a 2-ethylhexyl group, an isobutyl group, a 2-ethyloctyl group, a 2-hexyldecanyl group and the like are more preferable, and an isobutyl group and a 2-ethylhexyl group are particularly preferable.
Here, the aliphatic hydrocarbon group broadly refers to a group other than an aromatic hydrocarbon group, and may be a ring type or an acyclic type, and a part of hydrogen atoms constituting the aliphatic hydrocarbon group is, for example, , Alkyl group, alkenyl group, alkynyl group, cycloalkyl group, ether group and the like.
In R ^{1 to} R ³² , a part of the hydrogen atom is substituted with a nitrogen atom, a sulfur atom, an oxygen atom, a phosphorus atom or a silicon atom, or a substituent containing these, within a range not impairing the effect of the present invention. You may be.

Specifically, the compound represented by the general formula (1) is preferably the compound TSQ-1 represented by the following structural formula.

The squarylium derivative represented by the above general formula (1) can have a wide absorption in the deep HOMO and near-infrared regions by having an aromatic hydrocarbon group as a substituent at the terminal thereof, and also has a branched fat. By having a group hydrocarbon group, the solubility in an organic solvent is improved. For example, when the terminal substituent of the squarylium derivative is only an aromatic group, or the terminal substituent is an aromatic group and Compared with the case of having a linear aliphatic group, the molar extinction coefficient in the near infrared region and the solubility in an organic solvent are improved.
Therefore, the squarylium derivative can be suitably used as a donor material for an acceptor material composed of fullerene such as _{PC 71 BM or a derivative thereof.}

[Manufacturing method of squarylium derivative]
The squarylium derivative of the present invention can be produced, for example, by the method shown below. The manufacturing method of TSQ-1 is shown as an example.
1-Bromo-3,5-dimethoxybenzene and 4-chlorophenylboronic acid were added to the palladium (0) catalyst (Pd ₂ (dba) ₃ ), tri (tert-butyl) phosphine (P ( ^t Bu) ₃ ), and The Suzuki-Miyaura coupling reaction is carried out in the presence of potassium carbonate (K ₂ CO _{3) to obtain a Step 1 compound (Step 1).} Then, by Buchwald-Hartwig coupling, Step 1 synthesis and diisobutylamine were reacted to obtain Step 2 synthesis, then demethylated (Steps 2 and 3), and Step 3 synthesis and squaric acid were reacted. TSQ-1 can be synthesized in a good yield (Step 4). The obtained TSQ-1 ^{can be identified by 1 1} H-NMR, EI-MASS, and elemental analysis.
The squarylium derivative represented by the general formula (1) is not limited to the above method, and can be produced by various known methods.

[Organic electronic devices and their manufacturing methods]
The solar cell device, which is one form of the organic electronic device of the present invention, has an element structure in which at least one organic electroluminescence (EL) layer is laminated between a pair of electrodes (anode 2 and cathode 6), which is typical. Has an element structure in which a substrate 1, an anode 2, a hole transport layer 3, an active layer 4, an electron transport layer 5, and a cathode 6 are sequentially laminated as shown in FIG.
Hereinafter, the configuration of the solar cell device of the present invention will be described.

<Solar cell device configuration>
The configuration of the solar cell device of the present invention is not limited to the example of FIG. 7, and 1) the anode buffer layer (not shown) / hole transport layer / active layer, and 2) the anode are sequentially placed between the anode and the anode. Buffer layer (not shown) / active layer / electron transport layer, 3) anode buffer layer (not shown) / hole transport layer / active layer / electron transport layer, 4) anode buffer layer (not shown) / positive Layer containing hole-transporting compound, active compound and electron-transporting compound, 5) Anode buffer layer (not shown) / Layer containing hole-transporting compound and active compound, 6) Anode buffer layer (not shown) / Layer containing active compound and electron transporting compound, 7) Anode buffer layer (not shown) / Layer containing hole electron transporting compound and active compound, 8) Anode buffer layer (not shown) / Active layer / Positive Examples thereof include a configuration in which a hole block layer (not shown) / an electron transport layer is provided. The active layer shown in FIG. 7 is one layer, but may be two or more layers.

<Anode>
For the anode, a material having a surface resistance of usually 1000 Ω (ohm) or less, preferably 100 Ω or less in a temperature range of −5 to 80 ° C. is used.
When light is taken in from the anode side of the solar cell device (forward structure), the anode needs to be transparent to visible light (average transmittance for light of 380 to 680 nm is 50% or more). As the material of the anode, indium tin oxide (ITO), indium-zinc oxide (IZO) and the like are used. Of these, ITO is preferable from the viewpoint of availability.
Further, when light is taken in from the cathode side of the device (reverse structure), the light transmittance of the anode is not limited. Therefore, in addition to ITO and IZO, stainless steel, copper, silver, gold, and the like can be used as the anode material. A single substance of platinum, tungsten, titanium, tantalum or niobium, or an alloy thereof is used.
The thickness of the anode is usually 2 to 300 nm in the case of the forward structure in order to realize high light transmittance, and is usually 2 nm to 2 mm in the case of the reverse structure.

<Anode buffer layer>
The anode buffer layer is formed by applying a material for an anode buffer layer on the anode and further heating the anode.
In this coating operation, spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, dip coating method, spray coating method, screen printing method, flexographic printing method, offset printing method, A known coating method such as an inkjet printing method can be applied.
Further, as the material for the anode buffer layer, a material having high resistance to an organic solvent is usually used from the viewpoint of preventing the anode buffer layer from being dissolved during the formation of the active layer.
The thickness of the anode buffer layer is usually 5 to 50 nm, preferably 10 to 30 nm, from the viewpoint of sufficiently exerting the effect as the buffer layer and preventing an increase in the driving voltage of the solar cell element.

<Active layer, hole transport layer, electron transport layer>
The solar cell device is composed of an active layer, a hole transport layer and an electron transport layer.
As the active layer, a squarylium derivative represented by the general formula (1) is used. The squarylium derivative is usually used by mixing an acceptor material. By using the squarylium derivative as a donor material and forming the active layer 4 together with the acceptor material, a highly efficient organic solar cell device can be provided.
As the acceptor material, a known material is appropriately selected and used, but a compound having electron transport property and a deep energy level of HOMO is preferable, and specifically, fullerene (C60, C70, etc.) or a derivative thereof. A body (PC ₇₀ BM, etc.) is preferably used.

The active layer may be inserted between the hole transport layer and the electron transport layer as shown in FIG. 7 for the purpose of supplementing the carrier transport property of the active layer, or the acceptor material may be inserted into the active layer. At the same time, the hole transporting compound and the electron transporting compound may be dispersed and used.
Examples of the hole transporting compound include metal oxides such as molybdenum oxide (VI) (MoO ₃ ), vanadium oxide (V ₂ O ₅ ), tungsten oxide (WO ₃ ), ruthenium oxide (RuO ₂ ), and hexaaza. Introducing polymerizable functional groups into low molecular weight materials such as triphenylene hexacarbonyl (HATCN), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4TCNQ), and the low molecular weight materials. Then, the polymerized one and the like can be mentioned.
Examples of the electron-transporting compound include phenanthroline derivatives such as BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and B4PyMPM (bis-3,6- (3,5-di-4). Introducing polymerizable functional groups into low molecular weight materials such as oligopyridine derivatives such as −pyridylphenyl) -2-methylpyrimidine) and nanocarbon derivatives such as [60] fullerene and [70] fullerene, and the low molecular weight materials. Examples include polymerized ones.

<Hole block layer>
A hole block layer may be provided adjacent to the cathode side of the active layer for the purpose of suppressing holes from passing through the active layer and efficiently recombining with electrons in the active layer. For this hole block layer, a compound having a HOMO level deeper than that of the active compound is used, and for example, a triazole derivative, an oxadiazole derivative, a phenanthroline derivative, an aluminum complex and the like are used.
Further, an exciton block layer may be provided adjacent to the cathode side of the active layer in order to prevent excitons (excitons) from being deactivated by the cathode metal. For this exciton block layer, a compound having a triplet excitation energy larger than that of the active compound is used, and as the compound, a triazole derivative, a phenanthroline derivative, an aluminum complex and the like are used.

<Cathode>
As the cathode material, a material having a low work function (4 eV or less) and chemically stable is used. Specific examples thereof include known cathode materials such as Al, MgAg alloys, alloys of Al and alkali metals such as AlLi and AlCa. As a film forming method for these cathode materials, a resistance heating vapor deposition method, an electron beam vapor deposition method, a sputtering method, an ion plating method and the like are used. The thickness of the cathode is usually 10 nm to 1 μm, preferably 50 to 500 nm.

Further, for the purpose of lowering the electron injection barrier from the cathode to the power generation mechanism and increasing the electron injection efficiency, a metal layer having a work function lower than that of the cathode is inserted as a cathode buffer layer between the cathode and the layer adjacent to the cathode. You may. Examples of metals having a low work function that can be used for such purposes include alkali metals, alkaline earth metals, and rare earth metals. Further, alloys or metal compounds can also be used as long as they have a lower work function than the cathode. As a film forming method for these cathode buffer layers, a vapor deposition method, a sputtering method, or the like can be used. The thickness of the cathode buffer layer is usually 0.05 to 50 nm, preferably 0.1 to 20 nm.

Further, the cathode buffer layer can be formed as a mixture of the above-mentioned low work function metal or the like and an electron transporting compound. As a film forming method in this case, a co-deposited method can be used. When coating film formation with a solution is possible, a film forming method such as a spin coating method, a spray coating method, a dip coating method, or a printing method (inkjet printing method, dispenser coating method) can be used. The thickness of the cathode buffer layer in this case is usually 0.1 to 100 nm, preferably 0.5 to 50 nm. A layer made of a conductive polymer or a layer made of a metal oxide, a metal fluoride, an organic insulating material, or the like with an average thickness of 2 nm or less may be provided between the cathode and the organic material layer.

<Board>
A material that satisfies the mechanical strength required for a solar cell device is used for the substrate.
A substrate transparent to visible light is used for the bottom emission type solar cell device, for example, glass such as soda glass and non-alkali glass; acrylic resin, methacrylic resin, polycarbonate resin, polyester resin, nylon resin and the like. Transparent plastic; a substrate made of silicon or the like can be used.
Top-emission solar cell devices include substrates used for bottom-emission solar cell elements, as well as stainless steel, copper, silver, gold, platinum, tungsten, titanium, tantalum or niobium alone, or alloys thereof. Can be used as a substrate.
The thickness of the substrate is usually 0.1 to 10 mm, preferably 0.25 to 2 mm, although it depends on the required mechanical strength.
The film thickness of each layer is generally in the range of 5 nm to 5 μm.

(Method of forming a solar cell device)
The above-mentioned active layer, hole transport layer, and electron transport layer may be subjected to, for example, a dry process such as a vapor deposition method (resistive heating vapor deposition method, electron beam vapor deposition method, etc.), a sputtering method, or a coating method (spin coating method, casting method, etc.). , Die coat method, micro gravure coat method, gravure coat method, bar coat method, roll coat method, wire bar coat method, dip coat method, spray coat method, screen printing method, flexo printing method, offset printing method, inkjet printing method, etc. ) Etc. can be formed by a wet process. Of these methods, the spin coating method, the die coating method, and the spray coating method are preferably used.

In order to use the solar cell device stably for a long period of time, it is preferable to attach a protective layer and / or a protective cover around the solar cell device. A polymer compound, a metal oxide, a metal fluoride, a metal boride, or the like is used for the protective layer. A glass plate, a plastic plate whose surface has been subjected to a low water permeability treatment, a metal, or the like is used as the protective cover, and a method of sealing the cover with a thermosetting resin or a photocurable resin by adhering it to an element substrate is used. It is preferably used. Further, if an inert gas such as nitrogen or argon is sealed in the space, oxidation of the cathode can be prevented, and if a desiccant such as barium oxide is put in the space, the water adsorbed in the manufacturing process becomes the sun. It is possible to suppress giving a tame to the battery element.

[Use]
In addition to the solar cell device, the organic electronic device of the present invention is suitably used in an image display device as pixels by a matrix method or a segment method. Further, the organic electronic device is preferably used as a surface emitting light source without forming pixels.
Specifically, the organic electronic device of the present invention includes a display device, a backlight, an electrophotographic photograph, lighting, and a resist exposure in a computer, a television, a mobile terminal, a mobile phone, a car navigation system, a sign, a signboard, a viewfinder of a video camera, and the like. , Suitable for reading devices, interior lighting, light irradiation devices in optical communication systems and the like.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to the following Examples.

[Example 1] Synthesis of TSQ-1

(I) Step 1
Suzuki-Miyaura coupling reaction was performed. In a 50 ml three-necked flask, add 2.17 g (10 mmol) of 1-bromo-3,5-dimethoxybenzene, 1.65 g (10 mmol) of 4-chlorophenylboronic acid, 30 ml of toluene: ethanol = 2: 1 and 2.5 M. Add 10 mL of K ₂ CO _{3 aqueous solution, perform N 2} bubbling for 30 minutes _{, add Pd 2} (dba) ₃ 40 mg ( ^{0.05 mmol) and P (t} Bu) ₃ 0.07 mL (0.2 mmol), and add 4 The mixture was heated under reflux for hours.
The reaction solution was transferred to a separating funnel, 100 ml of toluene and 100 ml of ion-exchanged water were added, and the first washing was performed. The second and third times were washed by adding 100 ml of saturated brine. Then, it was dried with magnesium sulfate, the solvent was removed under reduced pressure with an evaporator, and purification was carried out by column chromatography on silica gel (developing solvent was toluene: hexane = 1: 2). The target product was obtained in a yield of 2.14 g and a yield of 87%.

(Ii) Step 2
A Buch-wald-Hartwig amination reaction was performed. Put 1.1 g (4.4 mmol) of Step 1 compound, 0.84 g (6.5 mmol) of diisobutylamine, ^{1.1 g (30 mmol) of t} BuOK, and 30 ml of dehydrated xylene in a _{50 ml four-necked flask, and add 30 N 2} bubbling. After minutes, Pd ₂ (dba) ₃ 40 mg (0.05 ^{mmol) and P (t} Bu) ₃ 0.07 mg (0.2 mmol) were added, and the mixture was heated under reflux for 18 hours.
The reaction solution was transferred to a separating funnel, about 100 ml of toluene and about 100 ml of ion-exchanged water were added, and the first washing was performed. The second and third times were washed by adding 100 ml of saturated brine. Then, it was dried with magnesium sulfate, the solvent was removed under reduced pressure with an evaporator, and purification was carried out by column chromatography on silica gel (developing solvent was toluene: hexane = 1: 2). The target product was obtained in a yield of 1.07 g and a yield of 72%.

(Iii) Step 3
The protecting group, methoxy group, was deprotected with _{BBr 3 and converted to a hydroxyl group.} Three-necked flask 25ml and under N ₂ atmosphere, Step 2 Synthesis was placed 1.07g of (6.3 mmol), and cooled for 30 minutes in an ice bath placed CH ₂ Cl ₂ (dehydrated). After that, _{8.0 ml (16 mmol) of BBr 3} was slowly added with a dropping funnel, the temperature was returned to room temperature, the mixture was stirred for 21 hours, and the mixture was sufficiently cooled in an ice bath again. To there, 10 ml of ion-exchanged water was slowly added with a dropping funnel.
_{CH 2} Cl ₂ was added to the reaction solution, the mixture was transferred to a separating funnel, washed with 100 ml of pure water, and then washed twice with 100 ml of saturated brine. Since most of the target product was precipitated, when extracted with toluene, only the target product could be isolated with a yield of 640 mg and a yield of 65%.

(Iv) Step 4
TSQ-1 was synthesized by a dehydration condensation reaction with squaric acid. 640 mg (2.0 mmol) of Step 3 compound and 116 mg (2.03 mmol) of squaric acid were placed in a 50 ml three-necked flask equipped with a Dean-Stark tube, and 60 ml of a solvent of toluene: butanol = 3: 1 was added. The reaction was carried out by heating and refluxing for 19 hours. As it was, the reaction solution was concentrated to about 10 ml using a Dean-Stark tube and cooled to 80 ° C. 30 ml of cyclohexane was added thereto, and the mixture was stirred for about 5 minutes and slowly cooled to room temperature. After sufficiently cooling, the target powder was recovered by filtration, and methanol was dispersed and washed. The desired product was obtained in a yield of 552 mg and a yield of 77%.
It was confirmed by EI-MASS (Fig. 1), ¹ H-NMR (Fig. 2 (a), (b)) and elemental analysis that TSQ-1 was produced.

MS: m / z 354 [M] ²⁺ ;
^{1 1} H-NMR (400 MHz, CDCl ₃ ): δ11.08 (s, 4H), 7.65 (d, 4H, J = 9.2 Hz), 6.73 (s, 4H), 6.69 (d, 4H, J = 9.2Hz), 3.25 (d, 8H, J = 7.6Hz), 2.18-2.08 (m, 4H), 0.94 (d, 24H, J = 6.4Hz) ) Ppm;
Anal. Calcd for C ₄₄ H ₅₂ N ₂ O ₆ ; C, 74.97; H, 7.44; N, 3.97%. Found: C, 74.97; H, 7.27; N, 3.87%

[Test Example 1] Solubility 2 mg of TSQ-1 was weighed into a sample tube, and 200 μL of chloroform was added to confirm the solubility.
[Test Example 2] Thermal characteristics The 5% weight decay temperature (Td) is measured by a thermogravimetric analyzer (TGA), and the glass transition temperature (Tg) and melting point (Tm) are measured by a differential scanning calorimetry device (DSC). It was measured.
In TGA, a sample of 3 to 5 mg was placed on an aluminum pan, and the temperature was raised to 500 ° C. at a heating rate of 10 ° C./min under a nitrogen atmosphere, and a 5% weight attenuation temperature (Td) was estimated (FIG. 3). (A)). Similarly, in DSC, a 3 mg sample is sealed in an aluminum pan, and the temperature is raised to a temperature of Td-20 ° C calculated by TGA at a temperature rise rate of 10 ° C./min under a nitrogen atmosphere to obtain a glass transition temperature. (Tg) and melting point (Tm) were measured (FIG. 3 (b)).

[Test Example 3] Optical characteristics (1) Measurement of UV-vis absorption spectrum A chloroform solution of TSQ-1 adjusted to a concentration of ^{10-5 M was placed in a quartz cell, and a dilute solution was measured.} The results are shown in FIG. 4 (a).
In addition, a chloroform solution of TSQ-1 adjusted to a concentration of 2 mg / ml was formed on a quartz substrate that had been _{UV / O 3 washed for 20 minutes by spin coating, and a single TSQ-1 film was measured.} .. The film forming conditions were a rotation speed of 2000 rpm, a solution concentration of 2 mg / mL, and a rotation time of 40 seconds. The results are shown in FIG. 4 (b).
TSQ-1 and PC ₇₁ BM were dissolved in chloroform (weight ratio TSQ-1: PC _{71 BM = 1: 2), and a chloroform solution of TSQ-1 and PC 71} BM adjusted to a concentration of 6 mg / mL was spin-coated. A film was formed on the quartz substrate and the mixed film of _{TSQ-1 and PC 71 BM was measured.} The film forming conditions were a rotation speed of 2000 rpm, a solution concentration of 6 mg / mL, and a rotation time of 40 seconds. The results are shown in FIG. 4 (c).
A UV-3150 manufactured by Shimadzu Corporation was used as the measuring device, and the measuring conditions were a medium speed scanning speed, a measuring range of 200 to 1000 nm, a sampling pitch of 1.0 nm, and a slit width of 1.0 nm. The energy gap (Eg) was estimated from the absorption edge of the UV-vis absorption spectrum, and the electron affinity (Ea) was calculated.

(2) Measurement of Emission Spectrum The single film was formed at a rotation speed of 2000 rpm, a solution concentration of 2 mg / mL, and a rotation time of 40 seconds. The _{film formation conditions for the mixed film with PC 71} BM were a rotation speed of 2000 rpm, a solution concentration of 6 mg / mL (weight ratio TSQ-1: PC ₇₁ BM = 1: 2), and a rotation time of 40 seconds. The measurement conditions were such that the measurement range was 580 to 850 (maximum) nm and the slit width was 1.0 nm.

(3) TSQ-1 single-layer, and, TSQ-1 / PC ₇₁ BM mixed film visually observed TSQ-1 single film, and the respective TSQ-1 / PC ₇₁ BM mixed film by spin coating deposition, photo I put it in. The film forming conditions for the TSQ-1 single film were a rotation speed of 2000 rpm, a solution concentration of 2 mg / mL, and a rotation time of 40 seconds. The film formation conditions for the TSQ-1 / PC ₇₁ BM mixed film were a rotation speed of 2000 rpm, a solution concentration of 6 mg / mL (weight ratio TSQ-1: PC ₇₁ BM = 1: 2), and a rotation time of 40 seconds. .. The results are shown in FIG.

[Test Example 4] Electrochemical properties HOMO / LUMO in a solution was measured using an ALS660B model electrochemical analyzer manufactured by BAS Co., Ltd. by cyclic voltammetry.
As for the measurement conditions, a 0.5 mM solution was prepared using the solvent dichloromethane (6 mL), sample (TSQ-1) 3 μmol, ferrocene 1.0 mg, and tetrabutylammonium tetrafluoroborate (TBABF ₄ ) 170 mg, and the measurement was performed. rice field. The results are shown in FIG.

1 Substrate 2 Cathode 3 Hole transport layer 4 Active layer 5 Electron transport layer 6 Cathode

Claims (2)

Squalylium derivative represented by the following general formula (1);

(In the general formula (1), Ar ¹ and Ar ⁴ each independently represent an aromatic substituent, Ar ² represents a substituent represented by the general formula (2), and Ar ³ represents the general formula (3). In the general formulas (1) to (3), R ^{1 to} R ³² independently represent a hydrogen atom, an aliphatic substituent or an aromatic substituent, respectively.) An organic electronic device containing the squarylium derivative according to claim 1.

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