JP2015155381A - Fluorine-containing aromatic compounds and production methods thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide organic semiconductor materials which are applicable to both a dry process and a wet process and have high carrier mobility.

SOLUTION: There are provided fluorine-containing aromatic compounds whose backbone is helicene type fused polycyclic systems, which is represented by general formula (A2). [R^f1 to R^f6 are each independently a C1-12 fluorine-containing alkyl group; X¹ to X⁴ are each independently N or CH; R is a halogen atom, or a C1-12 alkyl group; n is an integer from 0 to 4; and m is an integer from 0 to 2.]

COPYRIGHT: (C)2015,JPO&INPIT

Description

  The present invention relates to a novel fluorine-containing aromatic compound applicable to organic semiconductor materials and a method for producing the same.

  Organic semiconductor elements that use organic compounds as semiconductor materials are easier to process than semiconductor elements that use conventional inorganic semiconductor materials such as silicon. . Further, since organic compound semiconductor materials are structurally flexible, it is expected to realize devices such as flexible displays by using them in combination with a plastic substrate.

  As a process for processing an organic semiconductor, a dry process by vapor deposition and a wet process using an organic solvent such as coating, printable, and inkjet are known. Conventional organic semiconductor materials have low solubility in organic solvents, and it has been difficult to apply wet processes, and thus dry processes have been widely used. On the other hand, the wet process is an easy and inexpensive manufacturing process with a low environmental load.

  Organic semiconductor materials are required to have improved carrier mobility. Although effective means have not yet been established as means for improving the carrier mobility of organic semiconductor materials, it is considered important to strengthen the intermolecular interaction and control the molecular arrangement. Yes. For example, an acene compound that is a condensed polycyclic compound has been tried to be used as an organic semiconductor material because its conjugated system is expanded by a planar structure and has a strong intermolecular interaction due to a π stack (Non-patent Document 1). ).

  Of the condensed polycyclic compounds, acene compounds are expected to have excellent functions as organic semiconductor materials. For example, Patent Document 1 discloses a technique for increasing solubility in an organic solvent by introducing a group such as an alkyl group into an acene skeleton in order to use an acene compound as an organic semiconductor material by a wet process. Yes. Patent Document 2 discloses a method for producing an acene compound having a perfluoroalkyl group by a coupling reaction using a heavy metal.

  As another condensed polycyclic compound, for example, Patent Document 3 discloses a heterocyclic compound containing O, S, Se, or Te as a part of the core skeleton and further introduced with a substituent such as an alkyl group. There is disclosure that it can be used for electronic devices and optoelectronic devices.

JP 2007-13097 A International Publication No. 2011/022678 Special table 2012-512140 gazette

D. J. et al. Gundlach, S.M. F. Nelson, T .; N. Jachson et al. , Appl. Phys. Lett. , (2002), 80, 2925.

However, Patent Documents 1 and 2 do not disclose any helicene-type condensed polycyclic compounds having a skeleton of the present invention.
In addition, the heterocyclic compound described in Patent Document 3 has low solubility in an organic solvent due to the disclosed skeleton structure and the structure of a substituent introduced into the skeleton, and is difficult to apply to a wet process. Conceivable.

  The present invention is applicable to both a dry process and a wet process and provides a condensed polycyclic compound having a structure with high carrier mobility, a method for producing the same, and an organic semiconductor material containing the compound. Objective.

The present inventors have newly found a fluorine-containing aromatic compound having a specific structure that is relatively soluble in a low-polarity solvent, and have completed the present invention as an organic semiconductor material containing the fluorine-containing aromatic compound.

That is, the present invention relates to the following.
<1>
A fluorine-containing aromatic compound represented by the following formula (A) or a fluorine-containing aromatic compound represented by the formula (B).

[In the above formula,
R ^{f1 to} R ^f6 are each independently a fluorine-containing alkyl group having 1 to 12 carbon atoms.
X ^{1 to} X ⁴ are each independently a nitrogen atom or CH.
R is a halogen atom or an alkyl group having 1 to 12 carbon atoms.
n is an integer of 0-4.
m is an integer of 0-2. ]
<2>
The fluorine-containing aromatic compound according to <1>, wherein the fluorine-containing aromatic compound represented by the formula (A) is a fluorine-containing aromatic compound represented by the following formula (A2).

[Wherein R ^f1 , R, and n have the same meaning as described above. ]
<3>
The fluorine-containing aromatic compound according to <1>, wherein the fluorine-containing aromatic compound represented by the formula (B) is a fluorine-containing aromatic compound represented by the following formula (B2).

[Wherein R ^f3 , X ^{1 to} X ⁴ , R and m have the same meaning as described above. ]
<4>
A compound represented by the following formula:

<5>
The organic-semiconductor material containing the fluorine-containing aromatic compound of any one of said <1>-<4>.
<6>
The organic-semiconductor thin film containing the organic-semiconductor material as described in said <5>.
<7>
The organic semiconductor thin film according to <6>, wherein the organic semiconductor thin film is a crystalline thin film.
<8>
The organic-semiconductor element containing the layer of the organic-semiconductor thin film as described in said <7> as a semiconductor layer.
<9>
The organic-semiconductor transistor containing the organic-semiconductor element as described in said <8>.
<10>

A compound represented by the following formula (A1) is reacted with a compound represented by the formula R ^f1 —Si (CH ₃ ) ₃ to obtain a compound represented by the following formula (A1-1). -1) to obtain a compound represented by the following formula (A1-2) by deprotection treatment, and aromatize and oxidize the compound represented by the formula (A1-2). A method for producing a fluorine-containing aromatic compound represented by the following formula (A2).

[In the above formula,
R ^f1 is a fluorine-containing alkyl group having 1 to 12 carbon atoms.
R is a halogen atom or an alkyl group having 1 to 12 carbon atoms.
n is an integer of 0-4. ]
<11>
A compound represented by the following formula (B1) is reacted with a compound represented by the formula R ^f3 —Si (CH ₃ ) ₃ to obtain a compound represented by the following formula (B1-1). -1) to obtain a compound represented by the following formula (B1-2) by deprotection treatment, and aromatize and oxidize the compound represented by the formula (B1-2). A method for producing a fluorine-containing aromatic compound represented by the following formula (B2).

[In the above formula,
R ^f3 is a fluorine-containing alkyl group having 1 to 12 carbon atoms.
X ^{1 to} X ⁴ are each independently a nitrogen atom or CH.
R is a halogen atom or an alkyl group having 1 to 12 carbon atoms.
m is an integer of 0-2. ]

  The fluorine-containing aromatic compound in the present invention is a compound useful as an organic semiconductor material. Since the compound has a nitrogen atom in the core skeleton, the HOMO level is lowered and the oxidation resistance is improved. Further, by introducing a fluorine-containing alkyl group into a carbon atom forming an aromatic skeleton, the solubility of the compound in an organic solvent is increased, and an organic semiconductor thin film using a wet process can be manufactured. Furthermore, the fluorine-containing alkyl group that is an electron-withdrawing group has a strong cohesive force, enhances intermolecular interaction based on the fluorophyric effect, and can exhibit high carrier mobility as an organic semiconductor material.

  That is, the organic semiconductor material containing the fluorine-containing aromatic compound in the present invention is a useful compound that can form a high-performance organic semiconductor thin film and can be applied to an organic semiconductor element.

Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented without departing from the gist of the present invention.
In the present specification, the compound represented by the formula (1) is also referred to as “compound (1)”. The same applies to compounds represented by other formulas.

<Fluorine-containing aromatic compound>
The fluorine-containing aromatic compound according to the present invention is a fluorine-containing aromatic compound represented by the following formula (A) or a fluorine-containing aromatic compound represented by the formula (B).

[In the above formula,
R ^{f1 to} R ^f6 are each independently a fluorine-containing alkyl group having 1 to 12 carbon atoms.
X ^{1 to} X ⁴ are each independently a nitrogen atom or CH.
R is a halogen atom or an alkyl group having 1 to 12 carbon atoms.
n is an integer of 0-4.
m is an integer of 0-2. ]

  The fluorine-containing aromatic compound according to the present invention is a compound usefully used as an organic semiconductor material. As an organic semiconductor material, the material which consists only of the fluorine-containing aromatic compound of this invention may be sufficient, and the material which contains another component with the fluorine-containing aromatic compound may be sufficient. Other components will be described later.

In the condensed polycyclic compound represented by the formula (A) or the formula (B), the carrier mobility is expected to increase as the number of condensed rings increases due to strong intermolecular interaction due to π-π stacking. . On the other hand, strong intermolecular interactions also lead to a decrease in solubility in organic solvents.
In the present invention, by having fluorine-containing alkyl groups R ^{f1 to} R ^f6 in the minor axis direction of compound (A) or compound (B), that is, the direction perpendicular to the condensation direction of the aromatic ring, it is dissolved in an organic solvent. Increased sex dramatically. In addition, since the substitution positions of R ^{f1 to} R ^f6 are the above positions, steric hindrance between R ^{f1 to} R ^f6 hardly occurs, and the symmetry of the compound increases, so that the intermolecular bonds between the condensed rings are increased. It is effective for action. Furthermore, the fluorine-containing alkyl groups bonded to the same benzene ring are in a para-position, which means that when a fluorine-containing aromatic compound is used as an organic semiconductor material, the orientation with respect to the substrate is improved, and the thin film It is preferable from the viewpoint of crystallinity.

The fluorine-containing alkyl group refers to a group in which one or more hydrogen atoms of the alkyl group are substituted with fluorine atoms. The fluorine-containing alkyl groups R ^{f1 to} R ^f6 have 1 to 12 carbon atoms. The longer the alkyl chain in R ^{f1 to} R ^f6, the higher the solubility in organic solvents. Further, as the number of condensed rings increases, carrier mobility is expected to increase due to strong intermolecular interaction due to π-π stacking. In general, strong intermolecular interaction due to π-π stacking causes a decrease in solubility in an organic solvent. In the present invention, the number of carbon atoms in the linear perfluoroalkyl group and the acene material due to π-π stacking As a result of investigating the solubility in organic solvents, when a fluorine-containing alkyl group having 1 to 12 carbon atoms is introduced, the solubility of acene-based materials in organic solvents can be achieved without impairing strong intermolecular interaction due to π-π stacking. It became clear that improved dramatically.
The number of carbon atoms of R ^f1 to R ^f6 is 1 to 6 preferably 1 to 3 is more preferable.

R ^{f1 to} R ^f6 may be linear or branched, but are preferably linear in terms of improving the intermolecular interaction due to the interaction of fluorine atoms.

  The fluorine content of the fluorine-containing alkyl group (the fluorine content is the ratio of fluorine atoms to the total number of fluorine atoms and hydrogen atoms) is not limited, but the improvement of intermolecular interaction by the interaction of fluorine atoms Therefore, 80% or more is preferable, and 100% (that is, a perfluoroalkyl group in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms) is preferable.

That is, as R ^{f1 to} R ^f6 , from the viewpoint of the balance between intermolecular interaction and improved solubility, the formula — (CF ₂ ) _l F (where l is an integer of 1 to 12, An integer of 1 to 3 is particularly preferable, and a linear perfluoroalkyl group represented by formula (1) is particularly preferable, and a trifluoromethyl group and a pentafluoroethyl group are particularly preferable.

In addition, R ^{f1 to} R ^f2 in the compound (A) and R ^{f3 to} R ^f6 in the compound (B) may be the same or different from each other. The higher the number, the higher the symmetry of the crystal and the higher the symmetry of the crystal packing structure.

X ^{1 to} X ⁴ are each independently a nitrogen atom or CH. From the viewpoint of improving the decrease HOMO level oxidation resistance stability i.e. compounds of the compound, it is preferable nitrogen atom is large, more preferably at least 2 or more X ¹ to X ⁴ is a nitrogen atom, X ¹ most preferably all to X ⁴ is a nitrogen atom.

R is a halogen atom or an alkyl group having 1 to 12 carbon atoms. n is an integer of 0-4. m is an integer of 0-2.
When n is 2 or more and m is 2, a plurality of R may be the same or different. From the viewpoint of improving solubility and molecular orientation, n is preferably 0 to 2.
The substitution position of R is preferably a position where the symmetry of the compound is increased from the viewpoint of crystallinity and solubility. Specifically, taking the skeleton of compound (A) as an example, one or more positions selected from the 3-position, 4-position, 10-position, and 11-position shown in the following formula are preferred.

  Examples of the halogen atom as R include F, Cl, Br, and I, and Br and I are preferable from the viewpoint of reactivity. The fluorine-containing aromatic compound having a halogen atom is not only useful as a compound itself, but also can be converted into an arbitrary substituent by utilizing the reactivity of the halogen atom. That is, it is useful as an intermediate for introducing a desired substituent. Further, an organic semiconductor material having a desired function can be obtained from the intermediate.

  As a C1-C12 alkyl group as R, a C1-C10 alkyl group is preferable from a viewpoint of the solubility improvement with respect to an organic solvent. The alkyl group may be linear or branched, and is preferably linear from the viewpoint of improving crystallinity and molecular orientation.

The fluorine-containing aromatic compound according to the present invention is a compound in which the fluorine-containing alkyl groups R ^{f1 to} R ^f6 are the same group, that is, a compound represented by the following formula (A2) and a compound represented by the formula (B2) It is more preferable that

In formula (A2), the definitions, specific examples and preferred embodiments of R ^f1 , R and n are the same as those in formula (A).

In formula (B2), the definitions, specific examples and preferred embodiments of R ^f3 , X ^{1 to} X ⁴ , R and m are the same as those in formula (B).

  As the compound (A2), a compound represented by the following formula is particularly preferable.

As described above, the fluorinated aromatic compound in the present invention can realize high carrier mobility by strong intermolecular interaction due to the π-π stack of the condensed ring, and further, the fluorinated alkyl group in the compound. The solubility in an organic solvent can be improved by the presence of.
Therefore, the fluorine-containing aromatic compound in the present invention is useful as an organic semiconductor material having a high carrier mobility, and forms a high-performance organic semiconductor thin film in large quantities using a wet process that is simple and does not damage the substrate. It becomes possible. Furthermore, it becomes possible to obtain an excellent organic semiconductor element and organic semiconductor device using the organic semiconductor thin film.

<Method for producing fluorine-containing aromatic compound>
The fluorine-containing aromatic compound according to the present invention is a novel compound. Among the fluorine-containing aromatic ^compound, the same is R f1 ^{to R f6} group, the compound (A2) and the manufacturing method of the compound (B2) will be described.

<Method for producing compound (A2)>
The compound (A2) is obtained by reacting the compound represented by the following formula (A1) with the compound represented by the formula R ^f1 —Si (CH ₃ ) ₃ to obtain a compound represented by the following formula (A1-1). The compound represented by the formula (A1-1) is deprotected to obtain a compound represented by the following formula (A1-2), and the compound represented by the formula (A1-2) is fragrant. It can be obtained by grouping and oxidation.

In the above formula, the definitions, specific examples and preferred embodiments of R ^f1 , R and n are the same as those in the above formula (A).

  A known quinone compound can be used as the starting material compound (A1), and it can be synthesized according to a known method. Specific examples include the following compounds.

The compound represented by R ₁ —Si (CH ₃ ) ₃ (hereinafter, “—Si (CH ₃ ) ₃ ” is also referred to as “TMS”) to be reacted with the compound (A1) is 2 with respect to the compound (A1). An equivalent of 0.0 to 2.5 mol / gram is preferred. Furthermore, a carbonate is added in an amount of 0.3 to 0.4 mol / gram equivalent to the compound (1) and reacted in an organic solvent at room temperature for 6 to 18 hours to obtain a compound (A1-1).
Examples of the carbonate include alkali carbonate and the like, and potassium carbonate is particularly preferable. Examples of the organic solvent include amide solvents, among which N, N-dimethylformamide is preferable.

The reaction method for deprotecting the TMS group of the compound (A1-1) to convert it into the alcohol form (A1-2) is not limited, and examples thereof include a deprotection reaction by acid treatment using concentrated hydrochloric acid. In this case, for example, a method of adding 1 to 5 mol / gram equivalent of concentrated hydrochloric acid to the compound (A1-1) and reacting in an organic solvent under reflux for 3 to 24 hours is preferable.
As the organic solvent, a water-soluble organic solvent is preferable, and ethanol and tetrahydrofuran are particularly preferable.
The deprotection of the TMS group can also be carried out using a fluoride source such as tetrabutylammonium fluoride. A method of adding 1 to 5 mol / gram equivalent of tetrabutylammonium fluoride to the compound (A1-1) and reacting in an organic solvent at 0 ° C. for 0.5 to 5 hours is preferable. When the TMS group is deprotected, an alcohol form (A1-2) is obtained.

The aromatization of the compound (A1-2) is not limited because a known method can be applied, but in the present invention, a method using a heavy metal (for example, tin chloride) used in a general aromatization reaction is not applied. Is preferred. The aromatization is preferably aromatization via elimination of hydroxyl groups by heat treatment at 220 ° C. or higher in vacuum. Further, for example, an aromatization reaction using triphenylphosphine / carbon tetrabromide and a hydroxyl group elimination step is preferable. Specifically, carbon tetrabromide is added in an organic solvent in an amount of 3 to 10 mol / gram equivalent to the compound (A1-2), and kept at 0 ° C. Further, triphenylphosphine is added to the compound (A1-2). ) To 2 to 10 mol / gram equivalent amount, and a reaction in an organic solvent under reflux for 3 to 24 hours.
The organic solvent is preferably a chlorinated solvent, and examples thereof include dichloromethane, chloroform, and carbon tetrachloride, with dichloromethane being particularly preferred.

  After the aromatization, an oxidation reaction is performed. When compound (A1-2) is aromatized, an intermediate compound (also referred to as compound (A1-3)) in which a part of the nitrogen atom is converted to NH is formed, so NH is converted again to N. Therefore, an oxidation reaction is performed. As a compound (A1-3), the following compound is estimated, for example.

An example of the oxidation reaction is a method using MnO ₂ .

  The compound (A2) is generated by the above reaction.

<Method for producing compound (B2)>
The compound (B2) is obtained by reacting a compound represented by the following formula (B1) with a compound represented by the formula R ^f3 —Si (CH ₃ ) ₃ to obtain a compound represented by the following formula (B1-1). The compound represented by the formula (B1-1) is deprotected to obtain the compound represented by the following formula (B1-2), and the compound represented by the formula (B1-2) It can be obtained by grouping and oxidation.

Definitions, specific examples and preferred embodiments of R ^f3 , X ^{1 to} X ⁴ , R and m are the same as those in the above formula (B).

  As the starting material compound (B1), a known quinone compound can be used, and specific examples thereof include the following compounds.

A method of obtaining compound (B1-1) by reacting compound (B1) with a compound represented by the formula R ^f3 —Si (CH ₃ ) ₃ , and deprotecting compound (B1-1) to obtain compound (B1- The method for obtaining 2) and the method for aromatizing and oxidizing the compound (B1-2) are the same as the methods described in the method for producing the compound (A2).

  Similarly, when the compound (B1-2) is aromatized, an intermediate compound (also referred to as a compound (B1-3)) in which a part of the nitrogen atom is converted to NH is generated. As a compound (B1-3), the following compound (B1-3-1) and a compound (B1-3-2) are estimated, for example.

  According to the method for synthesizing a fluorinated aromatic compound in the present invention, since a coupling reaction using a heavy metal is not used when introducing a fluorinated alkyl group, the ratio of the heavy metal contained in the synthesized compound can be reduced. That is, in the fluorine-containing aromatic compound obtained by the method of the present invention, the amount of heavy metal contained in the compound can be reduced to 25 ppm by weight or less, preferably 20 ppm by weight or less.

<Organic semiconductor materials>
The organic semiconductor material is a material containing the above-described fluorine-containing aromatic compound. For example, the organic semiconductor material may be used by mixing with other organic semiconductor materials, or may contain various dopants. As the dopant, for example, when used as a light emitting layer of an organic EL device, coumarin, quinacridone, rubrene, stilbene derivatives, fluorescent dyes, and the like can be used.

  In addition, adjacent molecules aggregate due to the affinity between fluorine-containing alkyl groups (fluorophylic effect), contributing to more efficient charge transfer. Therefore, by using the fluorinated aromatic compound of the present invention, it is possible to produce an organic semiconductor thin film that retains high carrier mobility and an electronic device such as a transistor using the organic semiconductor thin film.

  In the fluorine-containing aromatic compound of the present invention, the conductivity can be changed because a fluorine-containing alkyl group which is an electron-attracting substituent is introduced. For example, the fluorine-containing aromatic compound of the present invention can change an electron transition energy by a fluorine-containing alkyl group, and can be an organic semiconductor material capable of controlling the conductivity type.

<Organic semiconductor thin film>
The organic semiconductor material according to the present invention can form a film on an organic semiconductor on a substrate using a dry process or a wet process according to a normal manufacturing method. Examples of the film include a thin film, a thick film, and a film having crystallinity.

When a thin film is formed by a dry process, the film can be formed using a known method such as a vacuum deposition method, an MBE (Molecular Beam Epitaxy) method, a sputtering method, a laser deposition method, or a vapor transport growth method.
Since these thin films function as charge transporting members for various functional elements such as photoelectric conversion elements, thin film transistors, and light emitting elements, various electronic devices having the thin films can be manufactured.

In the case of forming a thin film using a vacuum deposition method, an MBE method, or a vapor transport growth method as a dry process, a vapor obtained by heating and sublimating an organic semiconductor material is used in a high vacuum, a vacuum, a low vacuum, or a normal vacuum. Transported to the substrate surface with pressure. The thin film can be formed according to known methods and conditions. Specifically, a substrate temperature of 20 to 200 ° C. and a thin film growth rate of 0.001 to 1000 nm / sec are preferable. By setting it as this condition, a film having crystallinity and a thin surface smoothness can be formed.
When the substrate temperature is low, the thin film tends to be amorphous, and when the substrate temperature is high, the surface smoothness of the thin film tends to decrease. Further, if the growth rate of the thin film is slow, the crystallinity tends to decrease, and if it is too fast, the surface smoothness of the thin film tends to decrease.

When applying a wet process, the organic semiconductor material containing the fluorine-containing aromatic compound of the present invention is dissolved in an organic solvent, and the resulting solution is coated on a substrate by a wet process and then dried to form an organic semiconductor thin film. Can be formed.
The fluorine-containing aromatic compound of the present invention is a compound having an advantage that the solubility in an organic solvent is improved as compared with a conventional organic semiconductor material and a wet process can be applied. This is because the organic semiconductor material according to the present invention exhibits lipophilicity due to the presence of the perfluoroalkyl group in the fluorine-containing compound, and thus becomes soluble in various organic solvents. Film formation by a wet process has the advantage that it can be processed without damaging the semiconductor crystal.

  Examples of the film forming method (method for coating the substrate) in the wet process include coating, spraying, and contact. Specific examples include known methods such as spin coating, casting, dip coating, ink jet, doctor blade, screen printing, and dispensing. Moreover, when taking the form of a flat crystal or a thick film state, a casting method or the like can be adopted. It is preferable to select a combination suitable for the device to be produced for the film forming method and the organic solvent.

  In the wet process, crystal growth can be controlled by applying at least one selected from a temperature gradient, an electric field, and a magnetic field to the interface between the fluorine-containing aromatic compound solution and the substrate. By adopting this method, a highly crystalline organic semiconductor thin film can be produced, and excellent semiconductor characteristics based on the performance of the highly crystalline thin film can be obtained. In addition, a high crystalline organic semiconductor thin film can be manufactured by controlling the vapor pressure in solvent drying by making the environmental atmosphere a solvent atmosphere during wet process film formation.

  Examples of the organic solvent that can dissolve the fluorine-containing aromatic compound of the present invention in the wet process include aromatic hydrocarbons such as benzene, toluene, and xylene; diethyl ether, tert-butyl methyl ether, tetrahydrofuran, and dioxane. Examples of non-halogen solvents such as ethers such as; alcohols such as methanol, ethanol and 2-propanol; or mixtures thereof. When a mixed solvent is used, aliphatic hydrocarbons such as pentane, hexane, and heptane, and alicyclic hydrocarbons such as cyclohexane can be used in combination.

Examples of the organic solvent include halogen-containing solvents. Examples thereof include chlorinated hydrocarbons, fluorinated hydrocarbons, chlorinated fluorinated hydrocarbons, and fluorine-containing ether compounds. Specifically, methylene chloride, chloroform, 2,3,3-trichloroheptafluorobutane, 1,1,1,3-tetrachlorotetrafluoropropane, 1,1,1-trichloropentafluoropropane, 1,1- Dichloro-2,2,3,3,3-pentafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane, carbon tetrachloride, 1,2-dichloroethane, dichloropentafluoropropane _{, n-C 6 F 13 -C} 2 H 5, n-C 4 F 9 OCH 3, n-C 4 F 9 OC 2 H 5 and the like.
A solvent may use only 1 type or may use 2 or more types together. When using 2 or more types together, it is preferable to use a non-halogen type solvent and a halogen-containing solvent together, and the solvent which mixed these in arbitrary ratios is preferable.

When the wet process is performed by dissolving the fluorinated aromatic compound in the present invention in an organic solvent, the amount of the organic semiconductor material in the organic solvent is preferably 0.01% by mass or more, and about 0.2% by mass or more. From the viewpoint of working efficiency, etc. Furthermore, the amount of the organic semiconductor material in the organic solvent is preferably 0.01 to 10% by weight, particularly preferably 0.2 to 10% by weight.
In addition, since the fluorine-containing aromatic compound of the present invention is excellent in solubility in an organic solvent, the fluorine-containing aromatic compound obtained by the above production method can be highly purified by a simple purification method such as column chromatography or recrystallization. May be.

The coating on the substrate by the wet process can be performed in the air or in an inert gas atmosphere. In particular, when the solution of the semiconductor material is easily oxidized, it is preferably in an inert gas atmosphere, and nitrogen, argon, or the like can be used.
After coating the substrate, the organic semiconductor thin film is formed by volatilizing the solvent. If the residual amount of the solvent in the thin film is large, the stability of the thin film and the semiconductor properties may be deteriorated. Therefore, it is preferable to remove the remaining solvent by performing heat treatment or reduced pressure treatment again after the thin film is formed. .

  The shape of the substrate that can be used in the wet process is not particularly limited, and a sheet-like substrate or a plate-like substrate is usually preferable. The material used for the substrate is not particularly limited, and examples thereof include ceramics, metal substrates, semiconductors, resins, paper, and nonwoven fabrics.

  Examples of the substrate that is a ceramic substrate include glass, quartz, aluminum oxide, sapphire, silicon nitride, silicon carbide, and the like. Examples of the metal substrate include gold, copper, and silver substrates. Examples of the semiconductor substrate include silicon (crystalline silicon, amorphous silicon), germanium, gallium arsenide, gallium phosphide, gallium nitride, and the like. Polyester, polyethylene, polypropylene, polyvinyl, polyvinyl alcohol, ethylene vinyl alcohol copolymer, cyclic polyolefin, polyimide, polyamide, polystyrene, polycarbonate, polyether sulfone, polysulfone, polymethyl methacrylate, polyethylene terephthalate, triacetyl Examples of the substrate include cellulose and norbornene.

The organic semiconductor thin film using the fluorine-containing aromatic compound of the present invention can be a crystalline thin film. A crystalline thin film is preferable from the viewpoint that high carrier mobility can be expected due to high crystallinity and thereby excellent organic semiconductor device characteristics are exhibited.
The crystalline state of the thin film can be known by oblique incidence X-ray diffraction measurement of the thin film, transmission electron diffraction, or a method of measuring diffraction by making X-rays incident on the edge of the thin film. In particular, oblique incidence X-ray diffraction, which is a crystal analysis technique in the thin film field, is used. In X-ray diffraction, there are an Out-of-plane XRD method and an In-plane XRD method depending on the direction of the lattice plane to be measured. The Out-of-plane XRD method is a method for observing a lattice plane parallel to the substrate. The In-plane XRD method is a method for observing a lattice plane perpendicular to the substrate. That the thin film is crystalline means that a diffraction peak derived from the organic semiconductor material forming the thin film is observed. Specifically, diffraction based on crystal lattice of organic semiconductor material, diffraction derived from molecular length, or characteristic diffraction peak appearing when molecules have alignment parallel or perpendicular to the substrate are observed. Means that. In the case of a non-crystalline film, this diffraction is not observed, which means that the thin film in which the diffraction peak appears is a crystalline thin film.

  The thickness of the organic semiconductor thin film layer used for the organic semiconductor element is usually preferably 10 to 1,000 nm.

<Organic semiconductor element, organic semiconductor transistor>
The fluorine-containing aromatic compound in the present invention has a high carrier mobility. Therefore, an organic semiconductor material containing the compound can form an organic semiconductor thin film without impairing the high carrier mobility of the compound.
An organic semiconductor element including a semiconductor layer formed by laminating layers of organic semiconductor thin films is very useful for various semiconductor devices.

  Examples of the semiconductor device include an organic semiconductor transistor, an organic semiconductor laser, an organic photoelectric conversion device, and an organic molecular memory. Among these, an organic semiconductor transistor is preferable as the semiconductor device, and a field effect transistor (FET) is more preferable.

An organic semiconductor transistor is usually composed of a substrate, a gate electrode, an insulator layer (dielectric layer), a source electrode, a drain electrode, and a semiconductor layer. In addition, a back gate or a bulk may be included.
There are no particular restrictions on the order in which the components in the organic semiconductor transistor are arranged. Further, among the above components, a plurality of gate electrodes, source electrodes, drain electrodes, and semiconductor layers may be provided. When there are a plurality of semiconductor layers, they may be provided in the same plane or stacked.

  EXAMPLES The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples.

(Evaluation method)
In the examples, the structures of the synthesized compounds were identified by the following analysis methods and analysis conditions.

The nuclear magnetic resonance analysis was identified by a Fourier transform high resolution nuclear magnetic resonance apparatus (JNM-AL400) manufactured by JEOL.
¹ H NMR (300 MHz) Solvent: chloroform-d (CDCl ₃ ), methanol-d ₄ (CD ₃ OD) or acetone-d ₆ (acetone-d ₆ ). Internal standard: Tetramethylsilane (TMS).
¹³ C NMR (75 MHz) Solvent: chloroform-d (CDCl ₃ ), methanol-d ₄ (CD ₃ OD) or acetone-d ₆ (acetone-d ₆ ). Internal standard: chloroform -d (CDCl _3).
¹⁹ F NMR (283 MHz) Solvent: chloroform-d (CDCl ₃ ), methanol-d ₄ (CD ₃ OD) or acetone-d ₆ (acetone-d ₆ ). Internal standard: hexafluorobenzene (C ₆ F ₆ ) was set to −163 ppm (CFCl ₃ was set to 0 ppm).

For infrared absorption spectroscopy, a Fourier transform infrared spectrophotometer (FT-IR), FT / IR-4100 manufactured by JASCO Corporation was used.
For elemental analysis, a fully automatic elemental analyzer 2400 series II manufactured by PerkinElmer was used.
For the melting point measurement, a melting point measuring device MP-21 manufactured by Yamato Scientific Co., Ltd. was used.

Example 1
Method for producing 5,7,12,14-tetraaza-6,13-bis (trifluoromethyl) pentacene (compound (e)) Compound (e) was produced according to the following scheme.

  Method for producing compound (a) (5, 7, 12, 14-tetraaza-5, 14-dihydropentenecene)

2,200-dihydroxy-1,4-benzoquinone (2.80 g, 20 mmol), o-Phenylenediamine (8.64 g, 80 mmol), and acetic acid (50 mL) were put into an Ar-substituted 200 mL two-necked eggplant flask at reflux temperature. Stir for 8 hours. The reaction solution was cooled to room temperature and filtered, and the resulting solid was washed with acetone and dried to obtain compound (a).
(Reference: Tanq, Q .; Lianq, Z .; Liu, J .; Xu, J .; Miao, Q., Chem. Comm., 2010, 46, 2777-2979.)
¹ H NMR (300 MHz, DMSO-d6) δ 9.70 (2H, s), 7.65 (2H, dd, J = 3.5, 6.5 Hz), 7.41 (dd, J = 3.3) 6.3 Hz), 6.59 (2H, dd, J = 3.3, 5.7 Hz), 6.48 (dd, J = 3.0, 6.0 Hz), 6.32 (s, 2H).
¹³ C NMR could not be measured because the compound was hardly soluble.

  Preparation of Compound (b) (5,7,11,14-tetraaza-6,13-pentacenequinone)

Compound (a) (4.46 g, 15.7 mmol), H ₂ O (200 mL), H ₂ SO ₄ (50 mL), K ₂ Cr ₂ O ₇ (17.65 g, 60 mmol) are sequentially added to a 500 mL eggplant flask. , And stirred at 120 ° C. for 1 hour. The reaction solution cooled to room temperature was filtered, and the resulting solid was washed with water and acetone and then dried to obtain compound (b) (3.96 g, 12.68 mmol, 81% yield).
(Reference: Tanq, Q .; Liu, J .; Chan, H.-S .; Miao. Q., Chem. Eur. J., 2009, 15, 3965-3969.)
¹ H NMR (300 MHz, DMSO-d6) δ 8.47 (4H, dd, J = 3.5, 6.0 Hz), 8.18 (4H, dd, J = 3.6, 6.3 Hz).
¹³ C NMR could not be measured because the compound was hardly soluble.

  Production of Compound (c) (5,7,11,14-tetraaza-6,13-bis (trifluoromethyl) -pentacene-6,13-diol)

Compound (b) (0.562 g, 1.80 mmol) and THF (15 mL) were placed in a 50 mL two-necked eggplant flask containing CsF (0.109 g, 0.72 mmol), and the reaction solution was cooled to 0 ° C. CF ₃ TMS (0.80 mL, 5.4 mmol) was slowly added dropwise and stirred at room temperature for 15 hours. The reaction was quenched with a saturated aqueous ammonium chloride solution, extracted three times with ethyl acetate (20 mL), dried over Na ₂ SO ₄ and concentrated. THF (10 mL) was added to the obtained solid and cooled to 0 ° C. TBAF (3.7 mL, 3.7 mmol) was slowly added dropwise and stirred at 0 ° C. for 3 hours. The reaction was quenched with a saturated aqueous ammonium chloride solution, extracted three times with ethyl acetate (20 mL), dried over Na ₂ SO ₄ and concentrated. Column chromatography was performed with a developing solvent of hexane: ethyl acetate = 2: 1. The obtained solid was recrystallized using hexane: ethyl acetate = 1: 2 solvent to obtain Compound (c) (0.4063 g, 0.90 mmol, 50% yield).
¹ H NMR (300 MHz, CDCl ₃ ) δ 8.41 (4H, dd, J = 3.5, 6.5 Hz), 8.02 (4H, dd, J = 3.5, 6.5 Hz).
¹⁹ F NMR (283 MHz, CDCl ₃ ) δ-77.31 (s).
¹³ C NMR could not be measured because the compound was hardly soluble.
IR (KBr) 3459, 3056, 2560, 1994, 1613, 1551, 1490, 1415, 1352, 1240, 1198, 1157, 1128, 1051, 962, 919, 769, 736, 619.
m. p. > 300 ° C decompose
^{_{HRMS (ESI +, m / z}} ): [M + H] + calcd for C 20 H 10 F 6 N 4 O 2, 453.0786; Found, 453.0784.

  Production of Compound (d) (5,7,12,14-tetraaza-6,13-bis (trifluoromethyl) -5,14-dihydropentenecene)

PPh ₃ (0.680 g, 2.6 mmol), Br ⁻ P ⁺ Ph ₃ (0.889 g, 2.6 mmol), CHCl ₃ (5 mL) were placed in an Ar-substituted (50 mL) eggplant flask, and the reaction solution was 0. Cooled to ° C. To this solution, compound (c) (0.260 g, 0.576 mmol) dissolved in 10 mL of CHCl ₃ was slowly added dropwise and stirred at reflux temperature for 8 hours. The reaction was quenched with saturated aqueous ammonium chloride, extracted with dichloromethane, dried using Na ₂ SO ₄ and concentrated. Compound (d) (0.1595 g, 0.379 mmol, 66% yield) was isolated by recrystallization of the obtained solid using a chloroform solvent.
¹ H NMR (300 MHz, CDCl ₃ ) δ 7.91 (2H, dd, J = 3.5, 6.5 Hz), 7.65 (2H, s), 7.58 (2H, dd, J = 3.3) , 6.6 Hz), 6.85 (2H, dd, J = 3.3, 5.7 Hz), 6.60 (2H, dd, J = 3.3, 5.7 Hz).
¹⁹ F NMR (283 MHz, CDCl ₃ ) δ-53.81 (d, J = 9.1 Hz).
¹³ C NMR could not be measured because the compound was hardly soluble.
IR (KBr) 3461, 3067, 2909, 2812, 1549, 1442, 1378, 1333, 1274, 1217, 1178, 1139, 1015, 914, 678, 607, 566, 504, 488.
m. p. 165-190 ° C decompose
HRMS (ESI +, m / z): [M + H] ⁺ calcdfor C ₂₀ H ₁₁ F ₆ N ₄ , 421.0888; Found, 421.0866.

  Production of Compound (e) (5,7,12,14-tetraaza-6,13-bis (trifluoromethyl) pentacene)

Compound (d) (0.191 g, 0.453 mmol) and CHCl ₃ (10 mL) were placed in an Ar-substituted 50 mL two-necked eggplant flask and subjected to freeze deaeration. MnO ₂ (0.584 g, 6.795 mmol) was quickly added and stirred at reflux temperature for 5 hours. Celite filtration was performed to remove MnO ₂ and the solution was concentrated. The resulting solid was recrystallized using a solvent of MeOH: CHCl ₃ = 1: 1 to isolate compound (e) (0.1644 g, 0.393 mmol, 87% yield).
¹ H NMR (300 MHz, CDCl ₃ ) δ 8.25 (4H, dd, J = 3.6, 6.9 Hz), 7.92 (4H, dd, J = 3.3, 7.2 Hz).
¹⁹ F NMR (283 MHz, CDCl ₃ ) δ-50.02 (s).
¹³ C NMR could not be measured because the compound was hardly soluble.
IR (KBr) 3476, 3235, 3127, 3084, 3040, 2958, 2917, 2848, 2384, 2269, 1960, 1831, 1725, 1621, 1581, 1526, 1460, 1434, 1385, 1345, 1229, 1200, 1127, 1040, 919, 704, 612.
m. p. > 200 ° C decompose
^{_{HRMS (ESI +, m / z}} ): [M + H] + calcd for C 20 H 9 F 6 N 4, 419.0731; Found, 421.0711.

(Reference Example 1)
5,7,11,14-tetraaza-6,13-bis (pentafluoroethyl) -pentacene-6,13-diol (compound (f))

Compound (b) (0.312 g, 1.0 mmol) and THF (6 mL) were placed in a 50 mL two-necked eggplant flask containing CsF (0.060 g, 0.4 mmol), and the reaction solution was cooled to 0 ° C. C ₂ F ₅ TMS (0.437 g, 2.2 mmol) was slowly added dropwise and stirred at 60 ° C. for 16 hours. The reaction was quenched with a saturated aqueous ammonium chloride solution, extracted three times with ethyl acetate (20 mL), dried over Na ₂ SO ₄ and concentrated. THF (10 mL) was added to the obtained solid and cooled to 0 ° C. TBAF (1.2 mL, 1.2 mmol) was slowly added dropwise and stirred at 0 ° C. for 3 hours. The reaction was quenched with a saturated aqueous ammonium chloride solution, extracted three times with ethyl acetate (20 mL), dried over Na ₂ SO ₄ and concentrated. Compound (f) (0.0357 g, 0.068 mmol, 7% yield) was obtained by column chromatography using a developing solvent of hexane: ethyl acetate = 2: 1.
¹ H NMR (300 MHz, CDCl ₃ ) δ 8.39 (4H, dd, J = 3.5, 6.5 Hz), 8.02 (4H, dd, J = 3.6, 6.3 Hz), 5.41 (2H, s).
¹⁹ F NMR (283 MHz, CDCl ₃ ) δ-79.84 (3F, s), -121.41 (2F, s).
¹³ C NMR could not be measured because the compound was hardly soluble.
IR (KBr) 3466, 3073, 3056, 2924, 2852, 1994, 1966, 1849, 1737, 1653, 1612, 1551, 1485, 1466, 1405, 1343, 1281, 1227, 1205, 1171, 1159, 1009, 992, 880, 769, 620.
m. p. 252.2 ° C
^{_{HRMS (ESI +, m / z}} ): [M + H] + calcd for C 22 H 10 F 10 N 4 O 2, 553.0722; Found, 553.0714.

<Solubility test>
In order to examine the applicability of compounds to wet processes, solubility tests in various solvents were conducted. Compound (e) obtained by the method of Example 1, Compound (a) was used as Comparative Example 1, and pentacene, which is a condensed polycyclic compound and has the same number of rings, was used as Comparative Example 2. The solubility test was conducted.
Specifically, 20 mg of a sample was weighed, and the solubility (0.2% by mass) in 10 g of solvent at room temperature was judged visually.
The solvent types and results are shown in Table 1 below. In Table 1, ◯ represents soluble and x represents insoluble. Note that “soluble” in a solvent means that 0.2% by mass or more was dissolved at a solvent temperature of 25 ° C.

As a result of the solubility test, it was revealed that the compound (e) has higher solubility in organic solvents than the compound (a) and pentacene. This is considered to be an effect of introducing a trifluoromethyl group into the compound (e).
From this result, it can be said that the fluorine-containing aromatic compound according to the present invention can be applied to a wet process.

<Characteristics of organic semiconductor materials>
In order to evaluate the characteristics of the compound (e) as an organic semiconductor material, a deposited field effect transistor (deposited FET) element was fabricated, and field effect mobility (carrier mobility) was determined. A method for producing a vapor-deposited FET element and a method for evaluating semiconductor characteristics are shown below.

The cleaned silicon substrate with a silicon oxide film was immersed in a toluene solution of n-octyltrichlorosilane to treat the surface of the silicon oxide film. By vacuum-depositing the compound (e) obtained in Example 1 on the above substrate (back pressure 10 ⁻⁴ Pa, deposition rate 0.1 Å / s, substrate temperature 25 ° C., film thickness: 60 nm), An organic semiconductor layer was formed.

Gold was vacuum-deposited on this organic semiconductor layer using a shadow mask (back pressure: 10 ⁻⁴ Pa, deposition rate: 1 to 2 Å / s, film thickness: 50 nm), and source and drain electrodes were formed (channel length 50 μm). , Channel width 1 mm). The organic semiconductor layer and the silicon oxide film at portions different from the electrodes were scraped, and a conductive paste (Dotite D-550, manufactured by Fujikura Kasei Co., Ltd.) was attached to the portions, and the solvent was dried. Thus, a field effect transistor (FET) element having a top contact / bottom gate structure was produced.

The electrical characteristics of the obtained vapor-deposited FET element were evaluated in vacuum (<5 × 10 ⁻³ Pa) using a semiconductor device analyzer B1500A manufactured by Agilent. Using the silicon substrate of the vapor deposition FET element thus produced as a gate electrode, a voltage was applied to the silicon substrate, and the current / voltage curve between the source and drain electrodes was measured by scanning the gate voltage.
As a result, on / off operation of the drain current due to the gate voltage of the deposited FET element was observed, and the field effect mobility (carrier mobility) was obtained from the slope of the drain current / gate voltage. The organic semiconductor element formed using the compound (e) exhibited characteristics as an n-type transistor element. When the carrier mobility was determined from the saturation region in the current-voltage characteristics of the organic thin film transistor, it was 4.8 × 10 ⁻⁶ cm ² / V · s in vacuum.

The present invention provides an organic semiconductor material containing a fluorine-containing aromatic compound that can be used in either a dry process or a wet process and is expected to have high mobility, and a novel fluorine-containing aromatic compound.
According to the present invention, by introducing a fluorine-containing alkyl group with a condensed aromatic ring compound as a core, solubilization in an organic solvent is achieved, and a fluorine-containing aromatic compound having high carrier mobility is obtained as an organic semiconductor material. It is done.
Furthermore, by making a part of the core (main skeleton) part a nitrogen atom, the HOMO level of the compound can be lowered and the oxidation resistance can be improved.
The organic semiconductor material containing the compound of the present invention can be used for organic semiconductor (thin film) transistors, organic EL elements for next-generation flat panel displays, and organic thin film solar cells as lightweight and flexible power supplies.

Claims (11)

A fluorine-containing aromatic compound represented by the following formula (A) or a fluorine-containing aromatic compound represented by the formula (B).

[In the above formula,
R ^{f1 to} R ^f6 are each independently a fluorine-containing alkyl group having 1 to 12 carbon atoms.
X ^{1 to} X ⁴ are each independently a nitrogen atom or CH.
R is a halogen atom or an alkyl group having 1 to 12 carbon atoms.
n is an integer of 0-4.
m is an integer of 0-2. ] The fluorine-containing aromatic compound according to claim 1, wherein the fluorine-containing aromatic compound represented by the formula (A) is a fluorine-containing aromatic compound represented by the following formula (A2).

[Wherein R ^f1 , R, and n have the same meaning as described above. ] The fluorine-containing aromatic compound according to claim 1, wherein the fluorine-containing aromatic compound represented by the formula (B) is a fluorine-containing aromatic compound represented by the following formula (B2).

[Wherein R ^f3 , X ^{1 to} X ⁴ , R and m have the same meaning as described above. ] A compound represented by the following formula:

  The organic-semiconductor material containing the fluorine-containing aromatic compound of any one of Claims 1-4.   An organic semiconductor thin film comprising the organic semiconductor material according to claim 5.   The organic semiconductor thin film according to claim 6, wherein the organic semiconductor thin film is a crystalline thin film.   The organic-semiconductor element containing the layer of the organic-semiconductor thin film of Claim 7 as a semiconductor layer.   An organic semiconductor transistor comprising the organic semiconductor element according to claim 8. A compound represented by the following formula (A1) is reacted with a compound represented by the formula R ^f1 —Si (CH ₃ ) ₃ to obtain a compound represented by the following formula (A1-1). -1) to obtain a compound represented by the following formula (A1-2) by deprotection treatment, and aromatize and oxidize the compound represented by the formula (A1-2). A method for producing a fluorine-containing aromatic compound represented by the following formula (A2).

[In the above formula,
R ^f1 is a fluorine-containing alkyl group having 1 to 12 carbon atoms.
R is a halogen atom or an alkyl group having 1 to 12 carbon atoms.
n is an integer of 0-4. ] A compound represented by the following formula (B1) is reacted with a compound represented by the formula R ^f3 —Si (CH ₃ ) ₃ to obtain a compound represented by the following formula (B1-1). -1) to obtain a compound represented by the following formula (B1-2) by deprotection treatment, and aromatize and oxidize the compound represented by the formula (B1-2). A method for producing a fluorine-containing aromatic compound represented by the following formula (B2).

[In the above formula,
R ^f3 is a fluorine-containing alkyl group having 1 to 12 carbon atoms.
X ^{1 to} X ⁴ are each independently a nitrogen atom or CH.
R is a halogen atom or an alkyl group having 1 to 12 carbon atoms.
m is an integer of 0-2. ]