JP7029721B2 - Compounds, organic semiconductor materials, organic semiconductor devices, organic solar cells and organic transistors - Google Patents

Description

The present invention relates to a low molecular weight compound, an organic semiconductor material containing the same, an organic semiconductor device, an organic solar cell using the same, and an organic transistor.

In recent years, research and development on organic transistors and organic solar cells using organic semiconductor materials have been actively carried out. When an organic semiconductor material is used, a thin-film organic semiconductor layer can be produced by a simple method such as a printing method or a spin coating method by a wet process. Therefore, there are advantages that the manufacturing cost is lower than that of the inorganic semiconductor material, and that an organic semiconductor element which is thin and has excellent flexibility can be obtained.
For example, when a fullerene derivative such as phenyl C ₆₁ butyrate methyl ester or phenyl C ₇₁ butyrate methyl ester is used as an n-type organic semiconductor material in a bulk hetero-type organic solar cell, it is known to exhibit high photoelectric conversion efficiency. The disadvantage is that it is expensive. Therefore, from such a background, research and development of a π-extended n-type organic semiconductor material that can be an alternative to fullerene is being carried out. For example, Non-Patent Document 1 describes that the operation of a solar cell was confirmed by using a compound composed of naphthobisthiadiazole and condensed ring imide as an n-type organic semiconductor material.

Shreyam Chatterjee et al. , Adv. Funct. Mater. 26,1161-1168 (2016)

However, the solar cell using the material described in Non-Patent Document 1 has not yet obtained sufficient photoelectric conversion efficiency, and therefore further improvement is required.

As a result of searching for an extended conjugated compound that can be an alternative to fullerene showing good properties as an n-type organic semiconductor material, the present inventors have found that the compound represented by the following general formula (I) has excellent n-type organic semiconductor properties. We have found that we can achieve high photoelectric conversion efficiency as an organic semiconductor material and achieve even better carrier mobility, and completed the present invention. That is, the present invention exists as follows.

[1]. The compound represented by the following general formula (I).

（一般式（Ｉ）中、 Ｘ^１、Ｘ^２、Ｙ^１及びＹ^２は、それぞれ独立に、水素原子、フッ素原子、炭素原子数１－４０の直鎖状もしくは分岐状のアルキル基、又は少なくとも１つのフッ素原子で置換された炭素原子数１－４０の直鎖状もしくは分岐状のアルキル基であり、Ａ^１及びＡ^２は、それぞれ独立に、下記式で表される基であり、＊は結合手を示す。）

(In the general formula (I), X ¹ , X ² , Y ¹ and Y ² are independently hydrogen atoms, fluorine atoms, linear or branched alkyl groups having 1-40 carbon atoms, or at least. It is a linear or branched alkyl group having 1-40 carbon atoms substituted with one hydrogen atom, and A ¹ and A ² are independently represented by the following formulas, and * is a group. Shows the bond.)

（式中、Ｒ^１及びＲ^２は、それぞれ独立に、炭素原子数１－４０の直鎖状もしくは分岐状のアルキル基、又は少なくとも１つのフッ素原子で置換された炭素原子数１－４０の直鎖状もしくは分岐状のアルキル基であり、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８及びＲ^９は、それぞれ独立に、下記式で表される基である。）

(In the formula, R ¹ and R ² are independently substituted with a linear or branched alkyl group having 1-40 carbon atoms or at least one fluorine atom and having 1-40 carbon atoms. It is a chain or branched alkyl group, and R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are independently represented by the following formulas.)

（式中、Ｒは、炭素原子数１－４０の直鎖状又は分岐状のアルキル基を示す。）
［２］．［１］に記載の化合物を含む、有機半導体材料。
［３］．［２］に記載の有機半導体材料を含む層を有する、有機半導体素子。
［４］．［３］に記載の有機半導体素子を含む、有機太陽電池。
［５］．［３］に記載の有機半導体素子を含む、有機トランジスタ。

(In the formula, R represents a linear or branched alkyl group having 1-40 carbon atoms.)
[2]. An organic semiconductor material containing the compound according to [1].
[3]. An organic semiconductor device having a layer containing the organic semiconductor material according to [2].
[4]. An organic solar cell including the organic semiconductor device according to [3].
[5]. An organic transistor including the organic semiconductor device according to [3].

The compound according to the present invention has excellent n-type organic semiconductor properties because it has naphthobisthiadiazole substituted with a fluorine atom, which is a high electron accepting skeleton, and an aromatic imide, respectively. Therefore, the compound according to the present invention is useful as an organic semiconductor material for an organic solar cell having an even better photoelectric conversion efficiency, an organic transistor having an even better carrier mobility, and the like.

It is a figure which shows the current density-voltage characteristic in the organic solar cell of Example 1. FIG.

(Structure of compound)
The compound of the present invention is represented by the general formula (I).

In the above general formula (I), X ¹ and X ² are independently substituted with a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1-40 carbon atoms, or at least one fluorine atom. It is a linear or branched alkyl group having 1-40 carbon atoms. The number of carbon atoms of the alkyl group is preferably 1-10. Y ¹ and Y ² are independently substituted with a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1-40 carbon atoms, or 1-40 carbon atoms substituted with at least one fluorine atom. It is a linear or branched alkyl group of, and the number of carbon atoms of the alkyl group is preferably 1-30, more preferably 5-25. The aliphatic hydrocarbon group may be linear, branched or cyclic. A ¹ and A ² are independent groups represented by the following formulas, and * is a bond.

（式中、Ｒ^１及びＲ^２は、それぞれ独立に、炭素原子数１－４０の直鎖状もしくは分岐状のアルキル基、又は少なくとも１つのフッ素原子で置換された炭素原子数１－４０の直鎖状もしくは分岐状のアルキル基であり、アルキル基の炭素原子数は、好ましくは１－３０であり、より好ましくは５－２５である。Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８及びＲ^９は、それぞれ独立に、下記式で表される基である。）

(In the formula, R ¹ and R ² are independently substituted with a linear or branched alkyl group having 1-40 carbon atoms or at least one fluorine atom and having 1-40 carbon atoms. It is a chain or branched alkyl group, and the number of carbon atoms of the alkyl group is preferably 1-30, more preferably 5-25. R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are independent groups represented by the following formulas.)

（式中、Ｒは、炭素原子数１－４０の直鎖状又は分岐状のアルキル基を示す。）

(In the formula, R represents a linear or branched alkyl group having 1-40 carbon atoms.)

(Method for manufacturing compounds)
The method for producing the compound (I) is not particularly limited, but as an example, the compound (I) can be synthesized and produced from a commercially available compound according to the following reaction scheme. A more specific example is described in the examples below.

A compound represented by the general formula (V) is synthesized from commercially available naphthalene represented by the general formula (II) through steps A, B, and C, and then a compound represented by the general formula (V) is used in step D. , E, F to synthesize (I).

<Process A>
First, a compound represented by the general formula (III) (hereinafter referred to as “Compound (III)”) is produced from the compound represented by the general formula (II) (hereinafter referred to as “Compound (II)”) (step A). In compound (III), n represents any number from 0 to 4.

Step A specifically comprises, but is not limited to, at least one of, for example, nitration, halogenation, halogen substitution, boration, hydroxylation, amination, protection or deprotection. It is configured by appropriately selecting and combining necessary processes from the processes. Those skilled in the art can easily understand the selection and combination of necessary processes (the order in which the selected processes are performed).

<Process B>
Next, the compound represented by the general formula (IV) (hereinafter referred to as “compound (IV)”) is produced from the compound (III) (step B).

In step B, specifically, compound (IV) is produced by reacting compound (III) or a salt thereof with a sulfurizing agent (sulfurization reaction). The sulfurizing agent is not particularly limited as long as it is a sulfurizing agent in which the reaction proceeds, and is, for example, sulfur, sulfur dichloride, thionyl chloride, sulfuryl chloride, 2,4-bis (4-methoxyphenyl). )-1,3,2,4-dithiadiphosfetan-2,4-disulfide and the like. As the sulfurizing agent, 1 to 20 equivalents is preferable, and more preferably 2 to 5 equivalents can be used with respect to 1 equivalent of compound (III). The reaction of step B can usually be carried out in the presence of a base and a solvent. The base is not particularly limited as long as it is a base on which the reaction proceeds. The base is preferably used in an amount of 1 to 20 equivalents, more preferably 2 to 5 equivalents, relative to 1 equivalent of compound (III). The solvent is not particularly limited as long as it is a solvent in which the reaction proceeds. Further, a solvent that also serves as a base, such as pyridine and quinoline, may be used. The reaction temperature is usually preferably 0 to 200 ° C, more preferably 0 to 120 ° C. The reaction time is usually 1 to 48 hours. Compound (IV) is preferably purified before being subjected to step C.

<Process C>
Next, a compound represented by the general formula (V) (hereinafter referred to as “compound (V)”) is produced from the compound (IV) (step C).

Specifically, in step C, compound (V) is produced by reacting compound (IV) with a halogenating agent (brominating agent) (halogenation reaction). The halogenating agent is not particularly limited as long as it is a halogenating agent in which the reaction proceeds, and examples thereof include bromine and N-bromosuccinimide. The halogenating agent is preferably used in an amount of 1 to 20 equivalents, more preferably 2 to 5 equivalents, relative to 1 equivalent of compound (IV). The reaction of step C can usually be carried out in the presence of a solvent. The solvent is not particularly limited as long as it is a solvent in which the reaction proceeds. The reaction temperature is usually preferably 0 to 200 ° C, more preferably 0 to 120 ° C. The reaction time is usually 1 to 48 hours. Compound (V) is preferably purified before being subjected to step D.

By appropriately selecting and combining steps A to C as described above, a naphthobiscarcogenaziazole derivative represented by the formula (V) can be produced from the compound of the formula (II).
Specifically, it is preferable to carry out the following steps to produce a naphthobiscarcogenaziazole derivative.
(1) Difluoronaphthalene is produced by fluorinating diaminonaphthalene.
(2) Difluoronaphthalene is subject to an amination reaction to produce diamino-difluoronaphthalene or a hydrochloride thereof.
(3) Diamino-difluoro-dinitronaphthalene or a hydrochloride thereof is subjected to a nitration reaction to produce diamino-difluoro-dinitronaphthalene or a hydrochloride thereof.
(4) Diamino-difluoro-dinitronaphthalene or its hydrochloride is reduced to produce tetraamino-difluoronaphthalene or its hydrochloride.
(5) Tetraamino-difluoronaphthalene or a hydrochloride thereof is reacted with a sulfurizing agent, a selenium agent or a tellurizing agent to produce naphthobiscarcogenaziazole.
(6) The naphthobiscarcogenaziazole obtained in step (5) is reacted with a halogenating agent or a boronizing agent to produce a naphthobiscarcogenaziazole derivative.
Further, as another method, it is preferable to specifically carry out the following steps to produce a naphthobiscarcogenaziazole derivative (A ¹ and A ² are oxygen atoms).
(7) The diamino-difluoro-dinitronaphthalene or its hydrochloride obtained in the step (3) is oxidized and then reduced to obtain a naphthobiscarcogenaziazole derivative (A ¹ and A ² are oxygen atoms). To manufacture.
(8) The naphthobiscarcogenaziazole obtained in step (7) is reacted with a halogenating agent or a boronizing agent to obtain a naphthobiscarcogenaziazole derivative (A ¹ and A ² are oxygen atoms). To manufacture.

<Process D>
Next, a compound represented by the general formula (VIII) (hereinafter referred to as “compound (VIII)”) is produced from the compound (V) and the compound (VI) and / or the compound (VII) (step D). In compound (V), X ¹ , X ² , Y ¹ and Y ² , respectively, independently have a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1-40 carbon atoms, or at least one fluorine. It is a linear or branched alkyl group having 1-40 carbon atoms substituted with an atom. In compound (VI), X ¹ and Y ¹ are as described above. Further, in compound (VII), X ² and Y ² are as described above.

Specifically, in step D, for example, compound (V) and compound (VI) and / or compound (VII) are reacted in the presence of a catalyst in a solvent to produce compound (VIII). Examples of the solvent include toluene, chlorobenzene, DMF, tetrahydrofuran and the like. Examples of the catalyst include Pd (PPh ₃ ) ₄ , Pd (PPh ₃ ) ₂ Cl ₂ , Pd ₂ (dba) ₃ , and the like. Triphenylphosphine and tri (o-tolyl) phosphine may be added as the ligand. The reaction temperature can be, for example, 0 ° C to 200 ° C. Compound (VIII) is preferably purified prior to subjecting to step E.

<Process E>
Next, a compound represented by the general formula (IX) (hereinafter referred to as “compound (IX)”) is produced from the compound (VIII) (step E). In compound (IX), B ³ represents a bromine atom or an iodine atom. In compound (IX), X ¹ , X ² , Y ¹ and Y ² are as described above.

In step E, specifically, in a solvent such as methylene chloride and / or chloroform, compound (VIII) is bromine, N-bromosuccinimide (NBS), iodine, N-iodosuccinimide (NIS) or monochloride. Compound (IX) is produced by reacting with iodine or the like. The reaction temperature can be, for example, −78 ° C. to 60 ° C. The compound (IX) is preferably purified before being subjected to step F.

<Process F>
Then, the compound (X) or the compound (XI) is reacted with the compound (IX) to produce a compound represented by the general formula (I) (hereinafter referred to as “compound (I)”) (step F). In compound (I), X ¹ , X ² , Y ¹ and Y ² are as described above. In the general formula (I), A ¹ and A ² are each independently represented by the following formula, and * indicates a bond. )

（式中、Ｒ^１及びＲ^２は、それぞれ独立に、炭素原子数１－４０の直鎖状もしくは分岐状のアルキル基、又は少なくとも１つのフッ素原子で置換された炭素原子数１－４０の直鎖状もしくは分岐状のアルキル基であり、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８及びＲ^９は、それぞれ独立に、下記式で表される基である。）

(In the formula, R ¹ and R ² are independently substituted with a linear or branched alkyl group having 1-40 carbon atoms or at least one fluorine atom and having 1-40 carbon atoms. It is a chain or branched alkyl group, and R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are independently represented by the following formulas.)

（式中、Ｒは、炭素原子数１－４０の直鎖状又は分岐状のアルキル基を示す。）

(In the formula, R represents a linear or branched alkyl group having 1-40 carbon atoms.)

Specifically, in step F, for example, compound (X) or compound (XI) and compound (IX) are reacted in the presence of a catalyst and a base in a solvent to produce compound (I). Examples of the solvent include toluene, chlorobenzene, DMF, tetrahydrofuran and the like. Examples of the catalyst include Pd (PPh ₃ ) ₄ , Pd (PPh ₃ ) ₂ Cl ₂ , Pd ₂ (dba) ₃ , and the like. Triphenylphosphine and tri (o-tolyl) phosphine may be added as the ligand. The bases include alkali metal carbonates such as sodium carbonate, potassium carbonate and cesium carbonate; alkali metal alkoxides such as sodium methoxydo, sodium ethoxydo and potassium tertiary butoxide; alkali metal hydrogen carbonates such as sodium hydrogen carbonate. Salts; carbonates of alkaline earth metals such as calcium carbonate; metal hydroxides such as sodium hydroxide and potassium hydroxide; metal hydrides such as sodium hydride and potassium hydride; triethylamine, diisopropylethylamine, pyridine, 4- Organic amines such as (N, N-dimethylamino) pyridine; and the like. The reaction temperature can be, for example, 80 ° C to 200 ° C. The obtained compound (I) may be purified. In this way, the compound (I) of the present invention can be produced.

(Organic semiconductor material)
The compound (I) of the present invention can be used as an organic semiconductor material. In particular, it has an excellent effect as an n-type organic semiconductor material.

(Organic semiconductor device)
A layer containing the above-mentioned organic semiconductor material can be formed on a substrate and used as an organic semiconductor element. As the substrate, for example, glass or resin may be used. In order to form the layer containing the organic semiconductor material, a known method can be used to apply a solution dissolved in a solvent or to form the organic semiconductor material by vapor deposition.

(Organic semiconductor device)
Using the above-mentioned organic semiconductor element, electrodes and wiring can be provided as needed to obtain an organic semiconductor device. Organic semiconductor devices include organic electronics in general, for example, organic solar cells, organic transistors (organic field effect transistors, optical transistors, etc.), organic electroluminescence, sensors (optical sensors, etc.), memories, photoconductors, capacitors. And / or it can also be used in a battery or the like. It can also be used as a material for a proton conductive film.

(Organic solar cell)
An organic solar cell can be manufactured by using the above-mentioned organic semiconductor element. An organic solar cell has, for example, a structure in which an electrode layer, an electron transport layer (electron extraction layer), a photoelectric conversion layer (photoactive layer), a hole transport layer (hole extraction layer), and an electrode layer are laminated in this order on a substrate. Have. The organic semiconductor material containing the compound according to the present invention forms, for example, a photoelectric conversion layer (photoactive layer). Examples of the substrate include a substrate having light transmission so as not to impair the light receiving performance. As such a substrate, for example, colorless or colored glass, braided glass, glass blocks, or the like may be used, or a colorless or colored transparent resin may be used. Specific examples of such resins include polyesters such as polyethylene terephthalate, polyamides, polysulfones, polyethersulfones, polyether ether ketones, polyphenylene sulfides, polycarbonates, polyimides, polymethylmethacrylates, polystyrenes, and triacetyl celluloses. , And polymethylpentene and the like. Examples of the electrode include an ITO (Indium Tin Oxide) electrode, a silver electrode, an aluminum electrode, a gold electrode, a chromium electrode, a titanium oxide electrode, a zinc oxide electrode and the like. Examples of the electron transport layer (electron extraction layer) include organic semiconductor molecules such as phenanthroline, vasocuproin, and perylene and derivatives thereof; organic substances such as transition metal complexes; LiF, CsF, CsO, Cs ₂ CO ₃ , and TiOx (x). Is an arbitrary number from 0 to 2), and inorganic compounds such as ZnO; metals such as Ca and Ba; and the like. Examples of the hole transport layer (hole extraction layer) include conductive polymers such as PEDOT (polystyrene sulfonate, poly (stylene compound)), polypyrrole, polyaniline, polyfuran, polypyridine, and polycarbazole; MoO ₃ and WO ₃ and the like. Inorganic compounds; organic semiconductor molecules such as phthalocyanine and porphyrin and derivatives thereof; transition metal complexes; charge transfer agents such as triphenylamine compounds and hydrazine compounds; charge transfer complexes such as TTF (tetrathiafluvalene); etc. Examples include materials with high hole mobility.

When the compound (I) of the present invention is used as an n-type semiconductor material, the p-type semiconductor material used together as the hole transport layer (hole extraction layer) includes a donor-type π-conjugated polymer and a donor-acceptor-type π-conjugated polymer. Examples include molecules. Examples of donor-type π-conjugated polymers include poly-3-hexylthiophene (P3HT), poly-p-phenylene vinylene, poly-alkoxy-p-phenylene vinylene, poly-9,9-dialkylfluorene, and poly-p-phenylene. Vinylene can be mentioned. Examples of the donor unit in the donor acceptor type π-conjugated polymer include benzothiophene, dithienosyrole and N-alkylcarbazole, and examples of the acceptor unit include benzothiadiazole, thienothiophene and thiophenepyrroldione. A combination of these units, poly (thieno [3,4-b] thiophene-co-benzo [1,2-b: 4,5-b'] thiophene) (PTBx series), poly (dithione [1,2] -B: 4,5-b'] [3,2-b: 2', 3'-d] Pyrrole-alt- (2,1,3-benzothiadiazole) and other high molecular compounds can be mentioned. Of these, poly ({4,8-bis [(2-ethylhexyl) oxy] benzo [1,2-b: 4,5-b'] dithiophene-2,6-diyl} {3 is preferable. -Fluoro-2-[(2-ethylhexyl) carbonyl] thieno [3,4-b] thiophendiyl}) (PTB7), poly [4,8-di (2-ethylhexyloxy) benzo [1,2-b: 4,5-b'] Dithiophene] -2,6-diyl-alt- ((5-octylthioeno [3,4-c] pyrrole-4,6-dione) -1,3-diyl) (PBCTTPD), poly [(4,4'-bis (2-ethylhexyl) dithieno [3,2-b: 2', 3'-d] pyrrole) -2,6-diyl-alt- (2,1,3-benzothiadiazole-) 4,7-diyl) (PSBTBT), poly [N-9''-heptadecanyl-2,7-carbazole-alt-5,5- (4', 7'-di-2-thienyl-2', 1', 1' , 3'-benzothiadiazole)] (PCDTBT), poly [1- (6- {4,8-bis [(2-ethylhexyl) oxy] -6-methylbenzo [1,2-b: 4,5-b' ] Dithiophene-2-yl} {3-fluoro-4-methylthieno [3,4-b] thiophen-2-yl} -1-octanone) (PBDTTT-CF).

(Organic transistor)
An organic transistor can be manufactured by using the above-mentioned organic semiconductor element. Specifically, the organic transistor has a source electrode, a drain electrode, a gate electrode, and an active layer, and the organic semiconductor element can be used for the active layer.

Hereinafter, based on Examples, the synthesis of various compounds constituting the organic semiconductor material and the characteristics of the organic solar cell using the organic semiconductor material containing the compound will be described in more detail. It should be noted that these descriptions are examples of embodiments of the present invention, and the present invention is not limited to these examples.

[Compounds 1 to 3]
(Synthesis of Compound 1)
1,2,5,6-tetraamino-4,8-difluoronaphthalene hydrochloride (Compound 1) was synthesized by appropriately selecting and combining commercially available naphthalene derivatives in the production methods of halogenation and amination.

(Synthesis of 1,5-difluoronaphthalene)
In a 500 mL eggplant-shaped flask, 1,5-diaminonaphthalene (7.5 g) and water (200 mL) were placed, cooled to 0 ° C., and then concentrated sulfuric acid (12.6 mL) was added. Then, an aqueous solution (20 mL) of nitrite (8.21 g) was added dropwise at 0 ° C., and after completion of the addition, the mixture was stirred at 0 ° C. for 1 hour. Then, the mixture was stirred at room temperature for 1 hour. Then, the mixture was cooled to 0 ° C., HBF ₄ (38 mL) was added dropwise, and the mixture was stirred at 0 ° C. for 1 hour after the completion of the addition. The precipitate was collected by filtration, washed with water and methanol, and dried under reduced pressure to give a solid. The obtained solid (17.6 g) and 150 mL of chlorobenzene were placed in a 500 mL eggplant-shaped flask, and the mixture was heated under reflux for 3 hours. Then, the mixture was cooled to 0 ° C., water was added to the reaction solution, the mixture was extracted with chloroform, the organic layer was dried over anhydrous sodium sulfate, filtered, and the solvent was distilled off under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using hexane as a moving layer to obtain 1,5-difluoronaphthalene as a white solid (3.048 g, yield 39%). The reaction formula is shown below.

The physical characteristics of the obtained target product were measured. The measurement results are shown below.
^{1 1} H-NMR (400 MHz, CDCl ₃ ): δ = 7.88 (d, J = 8.4 Hz, 1H), 7.49-7.44 (m, 1H), 7.21 (dd, J = 7) .8Hz, 11Hz, 1H).

(Synthesis of 1,5-dibromo-4,8-difluoronaphthalene)
After adding 1,5-difluoronaphthalene (3.048 g) and trifluoroacetic acid (25 mL) to a 200 mL eggplant-shaped flask, N-bromosuccinimide (7.939 g) was added and the mixture was stirred at 70 ° C. for 16 hours. Then, the mixture was cooled to 0 ° C., water was added to the reaction solution, the obtained precipitate was collected by filtration, and washed with water and methanol. Then, it was dried under reduced pressure to obtain 1,5-dibromo-4,8-difluoronaphthalene as a light brown solid (5.321 g, yield 89%). The reaction formula is shown below.

The physical characteristics of the obtained target product were measured. The measurement results are shown below.
^{1 1} H-NMR (400 MHz, CDCl ₃ ): δ = 7.88 (dd, J = 4.2 Hz, 8.6 Hz, 2H), 7.12 (dd, J = 8.6 Hz, 12.6 Hz, 2H) ..

(Synthesis of 1,5-diamino-4,8-difluoronaphthalene hydrochloride)
In a 300 mL eggplant-shaped flask, 1,5-dibromo-4,8-difluoronaphthalene (5.00 g), tris (dibenzylideneacetone) dipalladium (0) -chloroform adduct (802 mg), rac-2,2'- Add bis (diphenylphosphino) 1,1'-binaphthyl (483 mg), sodium tert-butoxide (5.96 g), benzophenone imine (802 mg), and toluene (80 mL) to replace the inside of the flask with nitrogen, and at 110 ° C. The mixture was stirred for 16 hours. The precipitate was removed by filtration through cerite, washed with ethyl acetate, and the filtrate was distilled off under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using a hexane: ethyl acetate (1: 1) solvent as a moving layer. The reaction product obtained and THF (115 mL) were placed in a 300 mL eggplant-shaped flask, 2N hydrochloric acid (23.5 mL) was added at 0 ° C., and the mixture was stirred at 0 ° C. for 1 hour. The precipitate was collected by filtration and washed with tetrahydrofuran. Then, it was dried under reduced pressure to obtain 1,5-diamino-4,8-difluoronaphthalene hydrochloride as a light brown solid (2.00 g, yield 48%). The reaction formula is shown below. In the formula, n represents any number from 0 to 4.

The physical characteristics of the obtained target product were measured. The measurement results are shown below.
^{1 1} H-NMR (400 MHz, DMSO-d ₆ ): δ = 7.30-7.25 (m, 4H).

(Synthesis of N, N'-(4,8-difluoronaphthalene-1,5-diyl) bis (2,2,2-trifluoroacetamide))
1,5-Diamino-4,8-difluoronaphthalene hydrochloride (1.95 g) and dichloromethane (85 mL) were placed in a 300 mL eggplant-shaped flask and cooled to 0 ° C. Triethylamine (2.95 g) and trifluoroacetic anhydride (7.67 g) were added at 0 ° C., and the mixture was stirred overnight at room temperature. The resulting reaction mixture was dried under reduced pressure. Methanol was added to the precipitate, collected by filtration, and washed with methanol. Then, it was dried under reduced pressure to obtain N, N'-(4,8-difluoronaphthalene-1,5-diyl) bis (2,2,2-trifluoroacetamide) as a white solid (2.410 g, yield). 86%). The reaction formula is shown below.

The physical characteristics of the obtained target product were measured. The measurement results are shown below.
^{1 1} H-NMR (400 MHz, Acetone-d ₆ ): δ = 10.43 (br, 2H), 7.84-7.79 (m, 2H), 7.50 (dd, J = 8.4 Hz, 13) .6Hz, 2H).

(Synthesis of N, N'-(4,8-difluoro-2,6-dinitronaphthalene-1,5-diyl) bis (2,2,2-trifluoroacetamide))
In a 50 mL eggplant-shaped flask, N, N'-(4,8-difluoronaphthalene-1,5-diyl) bis (2,2,2-trifluoroacetamide) (500 mg) and concentrated sulfuric acid (10 mL) were placed. It was cooled to −45 ° C. Then, nitric acid (2.5 mL) was added, and the mixture was stirred at −45 ° C. for 5 minutes. The reaction mixture obtained was added to ice water, extracted with ethyl acetate, and the organic layer was washed with water. The organic layer was dried over anhydrous sodium sulfate, and after filtration, the solvent was distilled off under reduced pressure. Diethyl ether was added to the precipitated solid, and the solid was collected by filtration and washed with diethyl ether. Then, it was dried under reduced pressure to obtain N, N'-(4,8-difluoro-2,6-dinitronaphthalene-1,5-diyl) bis (2,2,2-trifluoroacetamide) as a light brown solid. (313 mg, yield 51%). The reaction formula is shown below.

The physical characteristics of the obtained target product were measured. The measurement results are shown below.
^{1 1} H-NMR (400 MHz, Acetone-d ₆ ): δ = 11.00 (br, 2H), 8.31 (d, J = 12.8 Hz, 2H).

(Synthesis of 1,5-diamino-4,8-difluoro-2,6-dinitronaphthalene hydrochloride)
N, N'-(4,8-difluoro-2,6-dinitronaphthalene-1,5-diyl) bis (2,2,2-trifluoroacetamide) (1.340 g), methanol in a 300 mL eggplant-shaped flask. (110 mL) and concentrated hydrochloric acid (55 mL) were added, and the mixture was stirred at 90 ° C. overnight. The reaction mixture was concentrated under reduced pressure. The precipitated solid was collected by filtration and washed with concentrated hydrochloric acid and dichloromethane. Then, it was dried under reduced pressure to obtain 1,5-diamino-4,8-difluoro-2,6-dinitronaphthalene hydrochloride as a dark brown solid (679 mg, yield 68%). The reaction formula is shown below. In the formula, n represents any number from 0 to 4.

The physical characteristics of the obtained target product were measured. The measurement results are shown below.
^{1 1} H-NMR (400 MHz, DMSO-d ₆ ): δ = 8.15 (br, 4H), 7.92 (d, J = 16.4 Hz, 2H).

(Synthesis of 1,2,5,6-tetraamino-4,8-difluoronaphthalene hydrochloride)
In a 300 mL eggplant-shaped flask, 1,5-diamino-4,8-difluoro-2,6-dinitronaphthalene hydrochloride (797 mg), concentrated hydrochloric acid (80 mL), and tin (II) chloride (8.46 g) were placed. The mixture was stirred at 70 ° C. for 1 hour. The precipitated solid was collected by filtration and washed with concentrated hydrochloric acid and dichloromethane. Then, it was dried under reduced pressure to obtain 1,2,5,6-tetraamino-4,8-difluoronaphthalene hydrochloride (Compound 1) as a brown solid (718 mg, 87% yield). The reaction formula is shown below. In the formula, m and n each independently represent any number from 0 to 4.

The physical characteristics of the obtained target compound 1 were measured. The measurement results are shown below.
^{1 1} H-NMR (400 MHz, DMSO-d ₆ ): δ = 6.94 (d, J = 16.8 Hz, 2H).

(Synthesis of compound 2)
5,10-Difluoronaphtho [1,2-c: 5,6-c'] bis [1,2,5] thiadiazole was synthesized.
In a 100 mL eggplant-shaped flask, the obtained 1,2,5,6-tetraamino-4,8-difluoronaphthalene hydrochloride (174 mg), pyridine (18 mL), and thionyl chloride (1.12 g) were placed and 90 ° C. Was stirred for 2 hours. Then, the reaction solution was dried under reduced pressure to obtain a solid. Methyl alcohol was added to the obtained solid and collected by filtration, and then the collected solid was washed with methyl alcohol. The washed solid is dried and is light brown with 5,10-difluoronaphtho [1,2-c: 5,6-c'] bis [1,2,5] thiadiazole (130 mg, 99%) (Compound 2). ) Was obtained. The reaction formula is shown below.

The physical characteristic data of the obtained compound 2 are as follows.
¹ HNMR (400 MHz, CDCl ₃ ): δ = 8.08-8.03 (m, 2H). ¹⁹ FNMR (565 MHz, CDCl ₃ ): δ = −107.71.

(Synthesis of compound 3)
Trifluoroacetic acid (20 mL), compound 2 (90 mg, 0.32 mmol) and N-bromosuccinimide (1.28 g, 7.2 mmol) were added to the reaction vessel, and the mixture was stirred at 70 ° C. for 20 hours. Then, water was added to the reaction solution, the precipitated yellow solid was filtered, and the mixture was washed with methanol to obtain Compound 3 (100 mg, 72%). The reaction formula is shown below.

得られた目的物の物性を測定した。測定結果を以下に示す。
^１９Ｆ－ＮＭＲ（４７０ＭＨｚ，ＣＤＣｌ_３）：δ＝－９９．９（ｓ）。融点（ｍ．ｐ．）＝２７０～２７２℃。

The physical characteristics of the obtained target product were measured. The measurement results are shown below.
¹⁹ F-NMR (470 MHz, CDCl ₃ ): δ = -99.9 (s). Melting point (mp) = 270-272 ° C.

[Compounds 4 to 6]
(Synthesis of compound 4)
Compound 4 was synthesized with reference to the procedure described in Document: Macromolecules, 46, 3391 (2013).

(Synthesis of Compound 5)
Tetrahydrofuran (30 mL), compound 3 (100 mg, 0.23 mmol), compound 4 (1.0 g, 2.2 mmol), tetrakis (triphenylphosphine) palladium (0) (30 mg, 1.5 mol%) were added to the reaction vessel. rice field. The reaction vessel was replaced with nitrogen and stirred at 120 ° C. for 12 hours. Then, water was added to the reaction solution, the mixture was extracted with chloroform, and the organic layer was washed with water. The organic layer was dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using a hexane: chloroform (1: 1) solvent as a moving layer to obtain Compound 5 as a red solid (134 mg, yield 87%).

The physical characteristic data of the obtained compound 5 are as follows.
¹ HNMR (400 MHz, CDCl ₃ ): δ = 8.21 (s, 2H), 7.18 (s, 2H), 2.64-2.62 (m, 4H), 1.67-1.64 ( m, 2H), 1.40-1.28 (m, 16H), 0.94-0.88 (m, 12H).

(Synthesis of Compound 6)
Tetrahydrofuran (15 mL), compound 5 (134 mg, 0.20 mmol) and N-bromosuccinimide (89 mg, 0.50 mmol) were added to the reaction vessel, and the mixture was stirred at 50 ° C. for 4 hours. Then, water was added to the reaction solution, the mixture was extracted with chloroform, and the organic layer was washed with water. The organic layer was dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using chloroform as a moving layer to obtain Compound 6 as a red solid (130 mg, yield 80%).

The physical characteristic data of the obtained compound 6 are as follows.
¹ HNMR (400 MHz, CDCl ₃ ): δ = 7.99 (s, 2H), 2.58-2.49 (m, 4H), 1.68-1.62 (m, 2H), 1.33- 1.17 (m, 8H), 1.11-0.98 (m, 8H), 0.94-0.89 (m, 12H). The reaction formula is shown below.

[Compounds 7 to 13]
(Synthesis of compound 7)
Compound 7 is described in Reference: J. Mol. Org. Chem. 81,8312-8318 (2016). It was synthesized with reference to the procedure described in.

(Synthesis of Compound 8)
N, N-dimethylformamide (5 mL), palladium (II) acetate (24 mg), 2-dicyclohexylphosphino-2', 4', 6'-triisopropylbiphenyl (XPhos) (94 mg) in a reaction vessel under a nitrogen atmosphere. Was added, and the mixture was stirred at room temperature. Then, compound 7 (620 mg) was added, and the mixture was stirred at room temperature for 30 minutes. Then, 3 equivalents of tert-butyl acrylate was added to triethylamine (2 mL) and compound 7, and the mixture was stirred at 90 ° C. for 12 hours. Then, the reaction solution was added to a mixed solvent of water and chloroform, extracted with chloroform, and the organic layer was washed with water. The organic layer was dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using a mixed solvent of hexane and ethyl acetate as a moving layer to obtain Compound 8 (315 mg, yield 40%).

The physical characteristic data of the obtained compound 8 are as follows.
¹ HNMR (400 MHz, CDCl ₃ ): δ = 8.14 (s, 2H), 8.10 (d, 2H, J = 8.0 Hz), 7.92 (d, 2H, J = 6.8 Hz), 7.69-7.66 (m, 2H), 1.65 (s, 18H).

(Synthesis of compound 9)
A mixed solvent of ethanol and water, compound 8 (315 mg) and sodium hydroxide (1.2 g) were added to the reaction vessel, and the mixture was stirred at 100 ° C. for 12 hours. Then, 2N hydrochloric acid was added to make the reaction solution acidic. Then, the precipitated solid was filtered and washed with water and methanol to obtain compound 9 (260 mg, yield 80%).

(Synthesis of compound 10)
Acetic anhydride (10 mL) and compound 9 (260 mg) were added to the reaction vessel, and the mixture was stirred at 130 ° C. for 4 hours. Then, the precipitated solid was filtered and washed with water and methanol to obtain compound 10 (200 mg, yield 82%).

The physical property data of the obtained compound 10 are as follows.
¹ HNMR (400 MHz, CDCl ₃ ): δ = 8.45 (s, 2H), 8.21 (d, 2H, J = 7.2 Hz), 8.10 (d, 2H, J = 8.0 Hz), 7.83-7.79 (m, 2H).

(Synthesis of compound 11)
Pyridine (10 mL), compound 10 (200 mg, 0.73 mmol) and 2-aminoheptane (180 mg, 1.56 mmol) were added to the reaction vessel, and the mixture was stirred at 140 ° C. for 12 hours. Then, water was added to the reaction solution, the mixture was extracted with ethyl acetate, and the organic layer was washed with water. The organic layer was dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using a hexane: ethyl acetate (10: 1) solvent as a moving layer to obtain Compound 11 as a yellow solid (235 mg, yield 87%).

The physical property data of the obtained compound 11 are as follows.
¹ HNMR (400 MHz, CDCl ₃ ): δ = 8.30 (s, 2H), 8.12 (d, 2H, J = 6.8 Hz), 8.00 (d, 2H, J = 8.0 Hz), 7.76-7.72 (m, 2H), 4.42-4.34 (m, 1H), 2.16-2.03 (m, 1H), 1.79-1.65 (m, 1H) ), 1.51 (d, 3H, J = 6.8Hz), 1.35-1.23 (m, 6H), 0.88-0.82 (m, 3H).

(Synthesis of compound 12)
Acetic acid (15 mL), compound 11 (235 mg, 0.64 mmol), 2-aminoheptane (180 mg, 1.56 mmol) and a catalytic amount of iodine were added to the reaction vessel. Then bromine (1.03 g, 6.4 mmol) was added slowly. Then, the mixture was stirred at room temperature for 20 hours. Then, an aqueous sodium thiosulfate solution was added to the reaction solution, and the mixture was stirred at room temperature. Then, water was added to the reaction solution, the mixture was extracted with ethyl acetate, and the organic layer was washed with water. The organic layer was dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using a hexane: ethyl acetate (10: 1) solvent as a moving layer to obtain Compound 12 as a yellow solid (200 mg, yield 70%).

The physical property data of the obtained compound 12 are as follows.
¹ HNMR (400 MHz, CDCl ₃ ): δ = 8.08-7.83 (m, 4H), 7.73-7.69 (m, 1H), 7.64-7.57 (m, 2H), 4.42-4.34 (m, 1H), 2.13-2.04 (m, 1H), 1.80-1.68 (m, 1H), 1.52 (d, 3H, J = 6) 0.8Hz), 1.35-1.23 (m, 6H), 0.86-0.82 (m, 3H).

(Synthesis of compound 13)
Under a nitrogen atmosphere, 1,4-dioxane (15 mL), compound 12 (200 mg, 0.45 mmol), bis (pinacolato) diborane (340 mg, 1.35 mmol), potassium acetate (450 mg, 4.5 mmol), [ 1,1'-Bis (diphenylphosphino) ferrocene] dichloropalladium (II) (37 mg, 0.050 mmol) was added. Then, the mixture was stirred at 90 ° C. overnight. Then, water was added to the reaction solution, the mixture was extracted with ethyl acetate, and the organic layer was washed with water. The organic layer was dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The obtained reaction mixture was separated and purified by silica gel column chromatography using a hexane: ethyl acetate (10: 1) solvent as a moving layer to obtain Compound 13 as a yellow solid (185 mg, yield 81%).

The physical property data of the obtained compound 13 are as follows.
¹ HNMR (400 MHz, CDCl ₃ ): δ = 8.71 (d, 1H, J = 8.8 Hz), 8.27 (d, 1H, J = 6.8 Hz), 8.20 (m, 2H), 8.03-7.99 (m, 2H), 7.72-7.68 (m, 1H), 4.42-4.33 (m, 1H), 2.14-2.03 (m, 1H) ), 1.79-1.65 (m, 1H), 1.51 (d, 3H, J = 6.8Hz), 1.45 (s, 12H), 1.38-1.26 (m, 6H) ), 0.86-0.82 (m, 3H). The reaction formula is shown below.

(Synthesis of compound 14)
Toluene (10 mL), compound 6 (130 mg, 0.16 mmol), compound 13 (198 mg, 0.40 mmol) and an aqueous sodium carbonate solution (1 mL, 2 mol / L) were added to the reaction vessel under a nitrogen atmosphere. Then, the mixture was stirred at 120 ° C. overnight. Then, water was added to the reaction solution, the mixture was extracted with chloroform, and the organic layer was washed with water. The organic layer was dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure. The obtained reaction mixture was separated and purified by gel permeation chromatography using chloroform as a moving layer to obtain compound 14 as a red solid (185 mg, yield 81%).

The physical property data of the obtained compound 14 are as follows.
¹ HNMR (400 MHz, CDCl ₃ ): δ = 8.46 (s, 2H), 8.29 (s, 2H), 8.26 (s, 2H), 8.15-8.06 (m, 6H). , 7.83 (d, 2H, J = 7.2Hz), 7.73-7.69 (m, 2H), 4.42-4.37 (m, 2H), 2.62 (d, 4H, J = 7.2Hz), 2.14-2.09 (m, 2H), 1.79-1.75 (m, 2H), 1.53 (d, 6H, J = 6.8Hz), 1. 28-0.83 (m, 36H), 0.67-0.61 (m, 12H). ¹³ CNMR (100MHz, CDCl ₃ ): δ = 168.8, 144.6, 144.0, 141.3, 135.2, 135.1, 133.9, 133.1, 131.7, 131.5 , 131.3, 129.6, 128.9, 127.9, 122.6, 121.9, 116.1, 47.7, 40.7, 33.9, 33.2, 32.5, 31 6.6, 28.6, 26.6, 25.8, 22.9, 22.6, 18.8, 14.1, 10.8. MS (MALDI) m / z = 1402.51 (M ⁺ ). Elemental analysis; theoretical value (carbon) 71.87%, (hydrogen) 5.74%, (nitrogen) 5.99%, measured value (carbon) 71.64%, (hydrogen) 5.94%, (nitrogen) 5.85%. The reaction formula is shown below.

Subsequently, an organic solar cell was produced using the synthesized compound 14, and the performance such as photoelectric conversion efficiency was evaluated.

[Performance evaluation of organic solar cells]
(Example 1)
An organic solar cell was evaluated using compound 14 as an n-type organic semiconductor material.
P3HT was used as the p-type organic semiconductor material, ITO (cathode) and aluminum (anode) were used as the electrodes, PEDOT: PSS was used as the hole transport material, and Ca was used as the electron transport material.
First, the glass substrate on which the ITO film is patterned is ultrasonically washed with toluene, acetone, water, and isopropyl alcohol for 15 minutes each, and then placed in a plasma washing machine to clean the substrate surface with plasma generated while inflowing oxygen gas. It was washed for 20 minutes. Further, the surface was washed by irradiating with ozone UV for 90 minutes. Then, a PEDOT: PSS thin film was formed on the ITO glass using a spin coating method film forming apparatus. Then, it was annealed at 135 ° C. for 10 minutes. The film thickness of the formed PEDOT: PSS was 30 nm. Further, using a spin coating method film forming apparatus, a solution containing P3HT (18 mg) and compound 14 (18 mg) previously dissolved in chlorobenzene (1 mL) was spin coated on the above-mentioned PEDOT: PSS thin film (3000 rpm, 2 minutes). ), And an organic semiconductor layer was formed to obtain a laminate. Then, using a small high-vacuum vapor deposition apparatus, the laminated band produced above is placed on a mask in the high-vacuum vapor deposition apparatus, and Ca (30 nm) as an electron transport layer and an aluminum layer (70 nm) as a metal electrode are sequentially placed. A film was formed to produce a 3 mm square organic solar cell.

The obtained organic solar cell was irradiated with constant light using a solar simulator (AM1.5G filter, irradiance 100 mW / cm ² ), and the generated current and voltage were measured. FIG. 1 shows a graph of current density-voltage characteristics.

When the short-circuit current density Jsc (mA / cm ² ), the open circuit voltage Voc (V), and the shape factor FF were obtained based on FIG. 1, Jsc = 5.66 mA / cm ² , Voc = 0.89, FF = 0. It was 60. The photoelectric conversion efficiency (η) was calculated from the formula η = (Jsc × Voc × FF) / 100 and found to be 3.0%.

As described above, it has been demonstrated that the compound of the present invention can achieve high photoelectric conversion efficiency as an n-type organic semiconductor material, which can be a substitute for, for example, a fullerene derivative.

Since the compound of the present invention has semiconductor properties such as good photoelectric conversion efficiency, it can be used as an organic semiconductor material in an organic semiconductor device such as an organic solar cell.

Claims (5)

The compound represented by the following general formula (I).

(In the general formula (I), X ¹ , X ² , Y ¹ and Y ² are independently hydrogen atoms, fluorine atoms, linear or branched alkyl groups having 1-40 carbon atoms, or at least. It is a linear or branched alkyl group having 1-40 carbon atoms substituted with one hydrogen atom, and A ¹ and A ² are independently represented by the following formulas, and * is a group. Shows the bond.)

(In the formula, R ¹ and R ² are independently linear or branched alkyl groups having 1-40 carbon atoms or linear chains having 1-40 carbon atoms substituted with at least one fluorine atom. It is a shaped or branched alkyl group, and R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are independently represented by the following formulas.)

(In the formula, R independently represents a hydrogen atom and a linear or branched alkyl group having 1-40 carbon atoms.) An organic semiconductor material containing the compound according to claim 1. An organic semiconductor device having a layer containing the organic semiconductor material according to claim 2. An organic solar cell comprising the organic semiconductor device according to claim 3. An organic transistor including the organic semiconductor device according to claim 3.

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