JP2009078975A - New fluorine-containing aromatic compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a π-conjugated compound which improves carrier mobility and the like, when used as an organic semiconductor material for organic thin film devices, and in which a hydrocarbon aromatic group is bound to a fluorine-containing aromatic group. <P>SOLUTION: The fluorine-containing aromatic compound represented by formula (1) [wherein, Ar<SP>F</SP>is a perfluoro aromatic group (one or more fluorine atoms in the perfluoro aromatic group may be replaced by one or more perfluoroalkyl groups); n is an integer of 1 to 4; Q is an n-valent aromatic group (wherein one or more hydrogen atoms in the aromatic group may be replaced by one or more 1-8C alkyl groups or 1-8C fluorine-containing alkyl groups) obtained by removing n hydrogen atoms from a structure represented by formula (2); (p) is an integer of 0 to 4]. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a novel fluorine-containing aromatic compound applicable to organic thin film devices.

  In recent years, organic electronic devices using organic compounds as semiconductor materials have made remarkable progress. Typical applications include organic EL elements (organic electroluminescence elements) that are expected as next-generation flat panel displays, organic thin-film solar cells as lightweight and flexible power supplies, and pixel driving of displays. There are organic thin film transistors (hereinafter referred to as “organic TFTs”) that are attracting attention because thin film transistors (TFTs) can be manufactured by a low-cost process such as printing and can be applied to flexible substrates.

  Since an organic compound is easier to process than inorganic silicon, it is expected to realize a low-cost device by using an organic compound as a semiconductor material. In addition, regarding a semiconductor device using an organic compound, since the device can be manufactured at a low temperature, a wide variety of substrates including a plastic substrate can be applied. Further, since organic compound semiconductor materials are structurally flexible, it is expected to realize devices such as flexible displays by using a combination of a plastic substrate and an organic compound semiconductor material.

In general, improvement in carrier mobility of organic semiconductor materials is demanded in order to increase the lifetime and drive voltage of organic EL elements, lower threshold voltage of organic TFT elements, and improve switching speed. Although the carrier mobility of organic semiconductor materials is generally low, in recent years, mobility comparable to amorphous silicon (> 1.0 cm ² / Vs) is being realized in an organic TFT element using pentacene (Non-patent Document 1). reference.).

In organic semiconductor materials, effective means for improving carrier mobility have not yet been established, but it is said that it is important to strengthen intermolecular interaction and control molecular arrangement. ing.
Specifically, examples using a condensed polycyclic compound such as pentacene having a conjugated system expanded by a planar structure and having a strong intermolecular interaction by a π stack (see Non-Patent Document 1), and electron withdrawing property. An example in which the molecular arrangement is controlled not only by causing the bias of the charge and enhancing the intermolecular interaction by coexisting the aromatic group and the electron donating aromatic group in the molecule (see Non-Patent Document 2) .)It has been known.

Further, as a means for enhancing the intermolecular interaction, an interaction between a fluorine-containing aromatic group and a hydrocarbon aromatic group is known (for example, see Non-Patent Document 3).
However, there are few examples of using this interaction to improve the carrier mobility of organic semiconductor materials, and there are examples in which fluorine atoms are introduced into the skeleton of pentacene, but the carrier mobility is not sufficiently high. (See Non-Patent Document 4).

D. J. et al. Gundlach, S.M. F. Nelson, T .; N. Jachson et al., Appl. Phys. Lett. , (2002), 80, 2925. H. Tada, Y .; Yamashita et al. , Materials Research Society Symposium Proceedings, (2002), 725, 143. G. W. Coates, J.A. W. Ziller, R.A. H. Grubbs et al. , J .; Am. Chem. Soc. , (1998), 120, 3641. J. et al. E. Anthony, G.M. G. Mallarias et al. Org. Lett. , (2005), 7 (15), 3163.

  The present invention provides a π-conjugated compound formed by bonding a hydrocarbon aromatic group and a fluorine-containing aromatic group, which can be used as an organic semiconductor material that solves the problems of the conventional techniques as described above. For the purpose.

  As a result of intensive studies to achieve the above object, the present inventors have found that when a specific fluorine-containing aromatic compound is used as an organic semiconductor material in an organic thin film device, the carrier mobility is expected to increase. The headline and the present invention were completed.

That is, the present invention provides the following (i) to (vii).
(I) A fluorine-containing aromatic compound represented by the following formula (1).

Ar ^F is a perfluoroaromatic group (however, the fluorine atom in the perfluoroaromatic group may be substituted with a perfluoroalkyl group).
n is an integer of 1 to 4.
Q is an n-valent aromatic group obtained by removing n hydrogen atoms from the structure represented by the following formula (2) (however, the hydrogen atom in the aromatic group has 1 to 8 carbon atoms) It may be substituted with an alkyl group or a fluorine-containing alkyl group having 1 to 8 carbon atoms).

p is an integer of 0-4.
(Ii) The fluorine-containing aromatic compound according to the above (i), wherein n is 2.
(Iii) Ar ^F is a perfluoroaromatic group selected from the group consisting of a perfluorophenyl group, a perfluoronaphthyl group, and a perfluorobiphenyl group, and p is 0 or 1, and the fluorine-containing fragrance according to (ii) above Group compounds.
(Iv) The fluorine-containing aromatic compound according to the above (iii), wherein p is 0, and the bonding positions of —C≡C—Ar ^{F in} Q are the 2nd and 6th positions.
(V) The fluorine-containing aromatic compound according to the above (iii), wherein p is 1, and the bonding positions of —C≡C—Ar ^{F in} Q are the 2nd and 6th positions, or the 9th and 10th positions. .
(Vi) The fluorine-containing aromatic compound represented by the above formula (1) is represented by the following formula (11), the following formula (12), and the following formula (13). In the above (iii), which is a compound selected from the group consisting of a compound, a compound represented by the following formula (14), a compound represented by the following formula (15) and a compound represented by the following formula (16) The fluorine-containing aromatic compound as described.

(Vii) An organic thin film device comprising an organic EL element having an anode, an organic compound layer having a structure of one or more layers, and a cathode on a substrate,
An organic thin film device in which the organic compound layer contains the fluorine-containing aromatic compound according to any one of (i) to (vi).

  Since the fluorine-containing aromatic compound of the present invention is expected to have a high carrier mobility as a charge transport material, it can be applied to high performance organic TFTs, organic EL devices and the like.

Hereinafter, embodiments of the present invention will be described in detail with reference to representative examples. First, the fluorine-containing aromatic compound of the present invention will be described.
The fluorine-containing aromatic compound of the present invention is a compound represented by the following formula (1). In the present specification, “compound represented by formula (1)” and the like are referred to as “compound (1)” and the like.

In the compound (1), Ar ^F is a perfluoroaromatic group. Here, the “perfluoroaromatic group” means a group in which all hydrogen atoms of a monovalent hydrocarbon group exhibiting aromaticity are substituted with fluorine atoms. However, the fluorine atom in the perfluoroaromatic group may be substituted with a perfluoroalkyl group. In this case, the perfluoroalkyl group is preferably a linear or branched alkyl group having 1 to 8 carbon atoms. Ar ^F is a perfluoroaromatic group selected from the group consisting of an unsubstituted perfluorophenyl group, an unsubstituted perfluoronaphthyl group, and an unsubstituted perfluorobiphenyl group (—C ₆ F ₄ C ₆ F ₅ ). Are preferred, and more preferred are an unsubstituted perfluorophenyl group or an unsubstituted perfluoronaphthyl group.

  In the compound (1), n represents an integer of 1 to 4. n is preferably 1 or 2, and more preferably 2.

  In the compound (1), Q is an n-valent aromatic group obtained by removing n hydrogen atoms from the structure represented by the following formula (2). However, the hydrogen atom in the aromatic group may be substituted with an alkyl group having 1 to 8 carbon atoms or a fluorine-containing alkyl group having 1 to 8 carbon atoms.

Here, p represents an integer of 0 to 4. p is preferably 0 or 1.
As Q, n is 2, and p is preferably 0 or 1, n is 2, p is 0 or 1, and the hydrogen atom in the aromatic group is unsubstituted. Is more preferable.
In the compound (1), it is preferable that the molecules are regularly arranged in the crystal structure, and therefore it is preferable that the symmetry of the molecule is high. From the viewpoint of molecular symmetry, the bonding position of —C≡C—Ar ^{F in} Q is preferably 2 and 6 when n is 2 and p is 0, When n is 2 and p is 1, it is preferably in the 2nd and 6th positions or the 9th and 10th positions.

  Further, the compound (1) is represented by the following formula (11), the following formula (12), the following formula (13), and the following formula (14). And a compound selected from the group consisting of a compound represented by the following formula (15) and a compound represented by the following formula (16).

  The production method of compound (1) is not particularly limited, but can be produced by the following method. For example, taking the case where n is 1 in the compound (1) as an example, it can be produced by the following method 1) or 2).

1) A method utilizing a coupling reaction with an ethynylene compound having an active proton represented by the following formula (a) or (b)

Q—C≡C—H + L—Ar ^F → Q—C≡C—Ar ^F + HL (a)
Or QL + H-C≡C-Ar ^F → Q-C≡C-Ar ^F + HL (b)

Here, Ar ^F and Q have the same meaning as in the above formula (1), and L represents a leaving group. The leaving group L is a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom. In this coupling reaction, it is preferable to use a transition metal such as palladium, copper, platinum or nickel, a salt thereof or a complex thereof as a catalyst. A catalyst may be used only by 1 type and may be used in mixture of 2 or more types. As an example of using a mixture of two or more, use a mixture of a zero-valent palladium catalyst such as tetrakis (triphenylphosphine) palladium (0) and a transition metal salt such as copper bromide or copper iodide. Is mentioned. In addition, a lithium halide salt such as lithium bromide or lithium iodide may be mixed and used for the catalyst.

  Moreover, as a solvent of this coupling reaction, the solvent which can capture | acquire HL to produce | generate is preferable, and an amine solvent is generally used. Specifically, for example, triethylamine, diisopropylamine, pyridine, pyrrolidine, and piperidine are used. These may be mixed with other solvents. In that case, it is preferable to use an aprotic solvent such as benzene, toluene or tetrahydrofuran as the other solvent.

  As reaction temperature of this reaction, it is preferable to carry out at 30-150 degreeC. Especially, it is preferable to carry out by heating to about 70-100 degreeC.

  The compound represented by the formula QC≡C—H in the reaction formula (a) can be produced, for example, by the following method.

Q-L + H-C≡C-C (CH ₃ ) ₂ OH
→ QC≡C-C (CH ₃ ) ₂ OH + HL (c)

Q-C≡C-C (CH ₃ ) ₂ OH
→ Q-C≡C-H + O = C (CH ₃ ) ₂ (d)

Here, Ar ^F , Q and L have the same meaning as in the above formula (a).
The reaction represented by the reaction formula (c) is a coupling reaction and can be performed under the same conditions as the coupling reaction represented by the above formula (a) or (b).
The reaction represented by the reaction formula (d) is a reaction for producing an ethynyl group by deacetone and is usually performed under basic conditions. Examples of the base used include potassium hydroxide, sodium hydroxide, calcium hydroxide, potassium carbonate, sodium carbonate and the like, and potassium hydroxide and sodium hydroxide are preferably used from the viewpoint of basic strength. In addition, this reaction is preferably carried out while rapidly removing the produced acetone from the system, and among them, it is preferred to carry out by heating under reduced pressure. The reaction pressure is preferably 0.01 to 0.5 Pa, more preferably 0.3 to 0.5 Pa. The reaction temperature is preferably 30 to 200 ° C. Among them, it is preferable to carry out by heating to about 100 to 150 ° C.

A compound represented by the formula H—C≡C—Ar ^F in the reaction formula (b) can also be produced by the same method.

2) A method utilizing a nucleophilic substitution reaction involving elimination of a fluorine atom represented by the following formula

Q-C≡C-M + F-Ar ^F → Q-C≡C-Ar ^F + MF

Here, Ar ^F and Q have the same meaning as in the above formula (1), and M represents a monovalent metal. As the monovalent metal M, lithium, potassium, sodium or the like can be used. This nucleophilic substitution reaction is preferably carried out in an aprotic polar solvent at a low temperature. The reaction temperature is preferably -80 to 10 ° C, more preferably -20 to 5 ° C. As a solvent for this reaction, an aprotic polar solvent is preferably used. Specifically, for example, diethyl ether, t-butyl methyl ether, tetrahydrofuran, dimethylformamide, dimethylacetamide, and dimethyl sulfoxide are used.

Next, the organic semiconductor material of the present invention and the organic thin film device of the present invention will be described.
The organic semiconductor material of the present invention is an organic semiconductor material containing the fluorine-containing aromatic compound of the present invention. The organic semiconductor material of the present invention only needs to contain the fluorine-containing aromatic compound of the present invention. For example, the organic semiconductor material may be used by mixing with other organic semiconductor materials, and may contain various dopants. Good. As the dopant, for example, coumarin, quinacridone, rubrene, stilbene derivatives, fluorescent dyes, and the like can be used when used as a light emitting layer of an organic EL element.
The organic thin film device of the present invention is an organic thin film device using the organic semiconductor material of the present invention. That is, the organic thin film device of the present invention is an organic thin film device containing the fluorine-containing aromatic compound of the present invention. Specifically, the organic thin film device of the present invention includes at least one organic layer, and at least one of the organic layers contains the compound (1) described above.

The organic thin film device of the present invention can be in various forms, and an organic TFT can be mentioned as one of preferred embodiments.
Specifically, an organic thin film device comprising an organic TFT having a gate electrode, a gate insulating layer, an organic semiconductor layer, a source electrode and a drain electrode on a substrate, wherein the organic semiconductor layer is the compound described above. The organic thin film device containing (1) is mentioned.
The compound (1) described above has high intermolecular interaction and high carrier mobility due to the interaction between the perfluoroaromatic group represented by Ar ^F and the hydrocarbon aromatic group represented by Q. Therefore, it is effective when used for an active layer of an organic TFT.

A board | substrate is not specifically limited, For example, it can be set as a conventionally well-known structure.
Examples of the substrate include glass (for example, quartz glass), silicon, ceramic, and plastic.
Examples of the plastic include general-purpose resin substrates such as polyethylene terephthalate, polyethylene naphthalate, and polycarbonate. The resin substrate is preferably a laminate of gas barrier films for reducing the permeability of gases such as oxygen and water vapor.

A gate electrode is not specifically limited, For example, it can be set as a conventionally well-known structure.
Examples of the gate electrode include metals such as gold, platinum, chromium, tungsten, tantalum, nickel, copper, aluminum, silver, magnesium, and calcium, or alloys thereof, polysilicon, amorphous silicon, graphite, and tin-doped indium oxide (hereinafter “ It is possible to use materials such as “ITO”, zinc oxide, and conductive polymers.

A gate insulating layer is not specifically limited, For example, it can be set as a conventionally well-known structure.
As the gate insulating layer, SiO ₂ , Si ₃ N ₄ , SiON, Al ₂ O ₃ , Ta ₂ O ₅ , amorphous silicon, polyimide resin, polyvinyl phenol resin, polyparaxylylene resin, polymethyl methacrylate resin, fluororesin ( Materials such as PTFE, PFA, PETFE, PCTFE, and CYTOP (registered trademark) can be used.

  The organic semiconductor layer is not particularly limited as long as it is a layer containing the compound (1). For example, it may be a layer consisting essentially only of the compound (1) or a layer containing a substance other than the compound (1).

The source electrode and the drain electrode are not particularly limited, and for example, a conventionally known configuration can be used.
As the source electrode and the drain electrode, any of metals such as gold, platinum, chromium, tungsten, tantalum, nickel, copper, aluminum, silver, magnesium, calcium or alloys thereof, polysilicon, amorphous silicon, graphite, ITO, Materials such as zinc oxide and conductive polymer can be used.

The laminated structure of the organic TFT includes a gate electrode, a gate insulating layer, an organic semiconductor layer, a source electrode and a drain electrode in this order from the substrate side (1), and a gate electrode from the substrate side. Any of the configurations (2) including the gate insulating layer, the source and drain electrodes, and the organic semiconductor layer in this order may be employed.
The manufacturing method of the organic TFT is not particularly limited. In the case of the configuration (1), for example, a top in which a gate electrode, a gate insulating layer, an organic semiconductor layer, a drain electrode, and a source electrode are sequentially stacked on a substrate. In the case of the configuration (2), there is a bottom contact method in which a gate electrode, a gate insulating layer, a drain electrode and a source electrode, and an organic semiconductor layer are sequentially stacked on the substrate.

The formation method of the gate electrode, the gate insulating layer, the source electrode, and the drain electrode is not particularly limited. For example, any of the above materials can be used, for example, a vacuum evaporation method, an electron beam evaporation method, an RF sputtering method, It can be formed by a known film production method such as spin coating or printing.
The formation method of the organic semiconductor layer is not particularly limited. For example, the organic semiconductor layer can be formed by a known film production method such as a vacuum deposition method, a spin coating method, an inkjet method, or a printing method using the above-described compound (1). it can.

Compound (1) has a chemical structure in which a perfluoroaromatic group represented by Ar ^F and a hydrocarbon aromatic group represented by Q are regularly arranged to some extent, and a perfluoroaromatic group The perfluoroaromatic group and the hydrocarbon aromatic group are alternately stacked by the interaction of the hydrocarbon aromatic group and have a stacked crystal structure. For this reason, intermolecular interaction is large, and high carrier mobility can be expected due to the overlap of π electron orbitals between molecules. Therefore, by using this material for an organic semiconductor layer (also referred to as “organic active layer”) of an organic TFT (field effect transistor), a large field effect mobility characteristic can be realized.

The organic thin film device of the present invention comprising an organic TFT is not particularly limited in use, but is suitably used as a TFT for driving a flexible display using a plastic substrate, for example.
In general, it is difficult to manufacture a TFT made of an inorganic material on a plastic substrate. However, in the manufacturing process of the organic thin film device of the present invention comprising the organic TFT, as described above, a process such as a vacuum deposition method, a spin coating method, an ink jet method, and a printing method is used, and a high temperature process is not used. In addition, a pixel driving TFT can be formed. In particular, since the compound (1) used in the present invention is soluble in general-purpose organic solvents such as chloroform and tetrahydrofuran, low-cost processes such as a spin coating method, an ink jet method, and a printing method can be applied, and the cost is low. Suitable for making paper-like (flexible) displays.

An organic EL element is mentioned as another suitable aspect of the organic thin film device characterized by including the compound (1) of this invention.
Specifically, an organic thin film device comprising an organic EL element having an anode, an organic compound layer having a structure of one or more layers, and a cathode on a substrate, wherein the organic compound layer is the compound (1) described above. Organic thin film devices containing

  A board | substrate, an anode, and a cathode are not specifically limited, All can be set as a conventionally well-known structure.

A board | substrate is not specifically limited, For example, it can be set as a conventionally well-known structure.
As a substrate, for example, a transparent material such as glass or plastic is preferably used. In addition, when light emission is taken out from the cathode side by making the cathode transparent, a material other than a transparent material, for example, silicon can be used.

  An anode is not specifically limited, For example, it can be set as a conventionally well-known structure. Specifically, a material that transmits light is used. More specifically, ITO, indium oxide, tin oxide, indium oxide, and zinc oxide alloy are preferable. Alternatively, a metal thin film such as gold, platinum, silver, or a magnesium alloy; a polymer organic material such as polyaniline, polythiophene, polypyrrole, or a derivative thereof can also be used.

  A cathode is not specifically limited, For example, it can be set as a conventionally well-known structure. Specifically, it is preferable from the viewpoint of electron injecting properties to use an alkaline metal such as Li, K, or Na having a low work function; an alkaline earth metal such as Mg or Ca. It is also preferable to use a halide of an alkali metal such as LiF, LiCl, KF, KCl, NaF, or NaCl and a stable metal such as Al provided thereon.

The organic compound layer has a structure of one or more layers, and the layer configuration is not particularly limited, and can be a conventionally known configuration, for example.
For example, from the anode side to the cathode side, a single layer structure composed of a light emitting layer, a two layer structure composed of a hole transport layer / light emitting layer, a two layer structure composed of a light emitting layer / electron transport layer, a hole transport layer / light emission 3 layer structure consisting of layer / electron transport layer, 4 layer structure consisting of hole injection layer / hole transport layer / light emitting layer / electron injection layer, hole injection layer / hole transport layer / light emitting layer / electron transport layer / A typical example is a five-layer structure comprising an electron injection layer.

As described above, the organic compound layer includes the compound (1) described above. The organic compound layer should just contain the compound (1) at least 1 layer among each layer used in the various layer structure mentioned above. For example, in the case of the five-layer structure, at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and an electron injection layer may contain the compound (1).
In the organic compound layer, the compound (1) described above may be used alone or in combination of two or more.
In the organic compound layer, a luminescent organic compound other than the compound (1) may be used in combination. The light emitting organic compound other than the compound (1) is not particularly limited, and for example, a conventionally known one can be used.

Each of the organic compound layers can have a conventionally known configuration, except that at least one layer contains the compound (1). Hereinafter, the case where the organic compound layer has a five-layer structure will be described as an example. However, the present invention is not limited to this.
Examples of the material constituting the hole injection layer or the hole transport layer include phthalocyanine derivatives, naphthalocyanine derivatives, porphyrin derivatives, aromatic tertiary amine derivatives, stilbene and polyvinylcarbazole, polythiophene, polyaniline, and other conductive polymer materials. Preferred examples include compounds having a highly donating skeleton or substituent. In particular, the material constituting the hole injection layer is preferably a compound having a low ionization potential that allows holes to be injected from the anode. Moreover, as a material which comprises a positive hole transport layer, the compound whose ionization potential is comparable as a light emitting layer is preferable.
Examples of the light emitting material or host material of the light emitting layer include quinoline metal complexes, aminoquinoline metal complexes, benzoquinoline metal complexes, and condensed polycyclic compounds such as anthracene, phenanthrene, pyrene, tetracene, coronene, chrysene, and perylene. . Further, a small amount of coumarin, quinacridone, rubrene, stilbene derivatives, fluorescent dyes and the like may be doped in the light emitting layer.
Specific examples of the material constituting the electron transport layer or the electron injection layer include oxadiazole, triazole, phenanthrene, bathocuproine, quinoline complex, perylenetetracarboxylic acid, and derivatives thereof. It is not limited.
Each of these layers may be composed of two or more layers.

  The layered structure in the organic EL element has, for example, a structure having an anode, one or more organic compound layers and a cathode in this order from the substrate side, and a structure having a cathode and one or more layers from the substrate side. The structure which has an organic compound layer and an anode in this order is mentioned.

  The method for producing the organic EL element is not particularly limited. For example, a method of sequentially stacking an anode, an organic compound layer, and a cathode on a substrate, and a cathode, an organic compound layer, and an anode on the substrate. The method of laminating sequentially is mentioned.

The formation method of the anode and the cathode is not particularly limited. For example, any of the above-described materials can be used, for example, a vacuum evaporation method, an electron beam evaporation method, an RF sputtering method, a spin coating method, an inkjet method, a printing method, It can be formed by a known film production method such as a spray method.
The formation method of the organic compound layer is not particularly limited. For the layer containing the above-described compound (1), for example, using the above-described compound (1), a vacuum deposition method, a spin coating method, a printing method, etc. It can be formed by a known film manufacturing method. Moreover, about the layer which does not contain the compound (1) mentioned above, a vacuum evaporation method, an electron beam evaporation method, RF sputtering method, a spin coat method, an inkjet method, a printing method, a spray method etc. are used, for example using the material mentioned above. The film can be formed by a known film manufacturing method.

In general, when a voltage is applied between an anode and a cathode in an organic EL element, holes are injected from the anode into the light emitting layer via a hole injection layer or a hole transport layer, and electrons are injected from the cathode. Injected into the light-emitting layer through the layer, the electron transport layer, etc., holes and electrons are recombined in the light-emitting layer, and the molecules of the light-emitting organic compound contained in the light-emitting layer are excited by the energy generated at that time, Excitons are generated. A light emission phenomenon occurs in the process in which the generated excitons are deactivated to the ground state.
Conventionally, when an organic EL element is put into practical use, reduction of driving voltage and increase of light emission quantum efficiency have been important issues. To solve this problem, holes are efficiently extracted from the anode and injected into the light emitting layer, electrons are efficiently extracted from the cathode and injected into the light emitting layer, and the holes and electrons are efficiently transported to the light emitting layer without loss. That is sought after.

In the present invention, since the compound (1) has excellent hole and electron transport properties, it is used for at least one of the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer of the organic EL device. And effective. Moreover, since it is necessary to inject both holes and electrons into the light emitting layer and recombine them, it is also preferable to use the light emitting layer.
Accordingly, by using the compound (1) having a high carrier mobility in at least one of the hole injection layer, the hole transport layer, the electron injection layer, the electron transport layer and the light emitting layer of the organic EL device, holes and electrons can be obtained. It becomes possible to efficiently inject into the light emitting layer, thereby increasing the light emitting efficiency and lowering the driving voltage.

The use of the organic thin film device of the present invention comprising an organic EL element is not particularly limited, but is suitably used for an organic EL display device, for example.
The organic EL display device includes an organic EL display element in which a plurality of organic EL elements serving as pixels are arranged.
For example, a passive organic EL element typically has a light emitting layer between intersections of anode wiring arranged in stripes and cathode wiring arranged in stripes so as to intersect the anode wiring. A structure in which an organic compound layer is sandwiched is formed, and a pixel as a light emitting element is formed at each intersection, and the pixels are arranged in a matrix.
An active organic EL display element can be formed by arranging elements in which organic TFTs for switching are combined with organic EL elements in a matrix.

In the organic thin film device of the present invention, as described above, it is possible to use a plastic substrate in addition to a glass substrate as a substrate of an electric device such as a transistor or an optical device such as an organic EL element.
The plastic used as the substrate is preferably excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, workability, low air permeability and low moisture absorption. Examples of such plastic include polyethylene terephthalate, polyethylene naphthalate, polystyrene, polycarbonate, polyacrylate, polyimide, and the like.

In the organic thin film device of the present invention, it is preferable to have a moisture permeation preventing layer (gas barrier layer) on one or both of the electrode-side surface and the surface opposite to the electrode of the substrate. Preferred examples of the material constituting the moisture permeation preventive layer include inorganic substances such as silicon nitride and silicon oxide. The moisture permeation preventing layer can be formed by a known film manufacturing method such as RF sputtering.
Further, the organic thin film device of the present invention may have a hard coat layer or an undercoat layer as necessary.

  The organic thin film device of the present invention can be in various modes other than the organic TFT and the organic EL described above. For example, the organic thin film solar cell is one of still another preferred embodiment of the organic thin film device characterized by including the compound (1) of the present invention.

  The use of the organic thin film device of the present invention is not particularly limited, and a display device (display), display element, backlight, optical communication, electrophotography, illumination light source, recording light source, exposure light source, reading light source, sign, signboard, interior It can be used for a wide range of applications such as batteries.

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these.
1. Synthesis of Intermediate (1) Synthesis of 2,6-diethynylnaphthalene As an intermediate used in the synthesis of compounds (11) and (12) described later, 2,6-di- Ethynylnaphthalene was synthesized.

A specific method for synthesizing 2,6-diethynylnaphthalene is shown below.
A 300 mL four-necked flask equipped with a thermocouple thermometer and a mechanical stirrer was charged with 20.15 g of 2,6-dibromonaphthalene, 2.0 g of tetrakis (triphenylphosphine) palladium (0) and 1.14 g of tritium. Phenylphosphine was charged and the system was purged with nitrogen. And 60 mL of triethylamine was charged. Further, 0.15 g of copper (I) bromide and 0.59 g of lithium bromide dissolved in 15 mL of tetrahydrofuran (hereinafter referred to as “THF”) were charged, and 23.9 g of 2-methylbuta-3 was added thereto. -In-2-ol was added. The system was then heated to 90-95 ° C. and stirred for 2-3 hours. Subsequently, after cooling the reaction system to room temperature, 200 mL of 0.5 mol / L hydrochloric acid was added, and the precipitated solid was collected by filtration. The recovered solid was washed with water, washed with toluene, and washed with methanol in this order, followed by vacuum drying at 50 ° C. for 2 hours to obtain almost pure 4,4 ′-(naphthalene-2,6-diyl. ) 16.0 g of bis (2-methylbut-3-in-2-ol) was obtained (yield: 77%) (see the above formula (A)).

The product thus obtained was transferred to a 300 mL four-necked flask equipped with a thermocouple thermometer and a mechanical stirrer, and charged with 29.8 g of liquid paraffin and 13.4 g of pulverized potassium hydroxide. And dispersed. Then, after reducing the pressure to 0.23 Pa, the system was heated to 100 to 130 ° C. and continued to be heated and stirred until there was no foaming due to generation of acetone. Subsequently, 100 mL of dichloromethane and 100 mL of water were added, and after stirring, insoluble solids were removed by filtration. The crude product was extracted with dichloromethane and concentrated to obtain a mixture with liquid paraffin, which was purified by column chromatography to obtain 7.3 g of almost pure 2,6-diethynylnaphthalene ( Yield: 86%) (see formula (B) above). 2,6-diethynylnaphthalene was identified by ¹ H-NMR analysis. The analysis results are shown below.

¹ H-NMR (300.4 MHz, solvent: CDCl ₃ , standard: TMS) δ (ppm); 3.18 (s, 2H), 7.53 (d, 2H), 7.74 (d, 2H), 7.98 (s, 2H)

(2) Synthesis of 2,6-diethynylanthracene As an intermediate used in the synthesis of compounds (13) and (14) described later, 2,6-diethynylanthracene is synthesized by the following formulas (C) and (D). did.

A specific method for synthesizing 2,6-diethynylanthracene is shown below.
A 50 mL three-necked flask equipped with a thermocouple thermometer and charged with a magnetic stirrer was charged with 1.0 g of 2,6-dibromoanthracene, 94 mg of tetrakis (triphenylphosphine) palladium (0) and 57 mg of triphenylphosphine. And the system was purged with nitrogen. Then, 2 mL of triethylamine was charged. Further, 12 mg of copper (I) bromide and 25 mg of lithium bromide dissolved in 0.75 mL of THF were charged, and 1.0 g of 2-methylbut-3-in-2-ol was added thereto. The system was then heated to 90-95 ° C. and stirred for 3-4 hours. Subsequently, after the reaction system was cooled to room temperature, 40 mL of 0.5 mol / L hydrochloric acid was added, and the precipitated solid was collected by filtration. The recovered solid was washed with water, washed with toluene and washed with methanol in this order, and then vacuum-dried at 50 ° C. for 2 hours to obtain almost pure 4,4 ′-(anthracene-2,6-diyl). ) 0.9 g of bis (2-methylbut-3-in-2-ol) was obtained (yield: 85%) (see formula (C) above).

0.8 g of the product thus obtained was transferred to a 200 mL four-necked flask equipped with a thermocouple thermometer and a mechanical stirrer, to which 2.2 g of liquid paraffin and 0.7 g of pulverized hydroxide were added. Potassium was charged and stirred and dispersed. Then, after reducing the pressure to 0.23 Pa, the system was heated to 100 to 130 ° C. and continued to be heated and stirred until there was no foaming due to generation of acetone. Subsequently, 40 mL of dichloromethane and 40 mL of water were added, and after stirring, insoluble solids were removed by filtration. The crude product is extracted with dichloromethane and chloroform and concentrated to give a mixture with liquid paraffin, which is purified by column chromatography to give 0.45 g of almost pure 2,6-diethynylanthracene. (Yield: 87%) (see formula (D) above). 2,6-diethynylanthracene was identified by ¹ H-NMR analysis. The analysis results are shown below.

¹ H-NMR (300.4 MHz, solvent: CDCl ₃ , standard: TMS) δ (ppm); 3.22 (s, 2H), 7.48 (d, 2H), 7.95 (d, 2H), 8.19 (s, 2H), 8.35 (s, 2H)

2. Synthesis of fluorinated aromatic compound (Example 1): Compound (11)
(1) Synthesis of compound (11) 1.7 g of 2,6-diethynylnaphthalene and 0.5 g of tetrakis (triphenylphosphine) were added to a 300 mL four-necked flask equipped with a thermocouple thermometer and a mechanical stirrer. Palladium (0) and 0.09 g of copper (I) bromide were charged and the system was purged with nitrogen. Subsequently, 35 mL of toluene and 4.5 mL of triethylamine were charged. Further, 7.3 g of bromopentafluorobenzene was added thereto. The system was then heated to 90-95 ° C. and stirred for 3-4 hours. Subsequently, after the reaction system was cooled to room temperature, 100 mL of 0.5 mol / L hydrochloric acid was added, and the precipitated solid was collected by filtration. The recovered solid was washed with water, washed with toluene, and washed with methanol in this order, and then vacuum-dried at 50 ° C. for 2 hours to obtain 4.1 g of a substantially pure compound (11) (yield) : 87%).

(2) Purification of Compound (11) By sublimation purification at 100 ° C. under a reduced pressure of 2.0 to 3.0 × 10 ⁻⁴ Pa, 2.0 g of Compound (11) obtained above. 1.8 g of pure white crystals were obtained. This white crystal was identified as 2,6-bis (pentafluorophenylethynyl) naphthalene (compound (11)) by ¹⁹ F-NMR and ¹ H-NMR analyses. The analysis results are shown below.

¹⁹ F-NMR (282.7 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) δ (ppm); −136.34 (4F), −152.70 (2F), −162.14 (4F)
¹ H-NMR (300.4 MHz, solvent: CDCl ₃ , standard: TMS) δ (ppm); 7.64 (d, 2H), 7.84 (d, 2H), 8.11 (s, 2H)

Example 2 Compound (12)
(1) Synthesis of Compound (12) In a 300 mL four-necked flask equipped with a thermocouple thermometer and a mechanical stirrer, 0.3 g of 2,6-diethynylnaphthalene and 0.09 g of tetrakis (triphenylphosphine) Palladium (0) and 0.03 g of copper (I) bromide were charged and the system was purged with nitrogen. Subsequently, 6 mL of toluene and 0.75 mL of triethylamine were charged. Further, 1.7 g of 2-bromoheptafluoronaphthalene was added thereto. The system was then heated to 90-95 ° C. and stirred for 3-4 hours. Subsequently, after the reaction system was cooled to room temperature, 100 mL of 0.5 mol / L hydrochloric acid was added, and the precipitated solid was collected by filtration. The collected solid was washed with water, washed with toluene, and washed with acetone in this order, and then vacuum-dried at 60 ° C. for 2 hours to obtain 5.6 g of a substantially pure compound (12) (yield) : 92%).

(2) Purification of compound (12) 1.0 g of compound (12) obtained above is purified by sublimation at 350 ° C. under a reduced pressure of 5.5 to 6.0 × 10 ⁻⁴ Pa. 0.5 g of pure white crystals were obtained. This white crystal was identified as 2,6-bis ((heptafluoronaphthalen-2-yl) ethynyl) naphthalene (compound (12)) by ¹⁹ F-NMR and ¹ H-NMR analyses. The analysis results are shown below.

¹⁹ F-NMR (282.7 MHz, solvent: THF-d ₈ , reference: CFCl ₃ ) δ (ppm); -113.1 (2F), -134.5 (2F), -144.1 (2F), -144.6 (2F), -149.3 (2F), -153.2 (2F), -156.3 (4F)
¹ H-NMR (300.4 MHz, solvent: THF-d ₈ , standard: TMS) δ (ppm); 7.74 (d, 2H), 8.03 (d, 2H), 8.29 (s, 2H )

Example 3 Compound (13)
(1) Synthesis of Compound (13) A thermocouple thermometer was attached and a 50 mL three-necked flask charged with a magnetic stirrer was charged with 0.29 g of 2,6-diethynylanthracene and 88 mg of tetrakis (triphenylphosphine). Palladium (0) and 19 mg of copper (I) bromide were charged and the system was purged with nitrogen. Subsequently, 6 mL of toluene and 0.75 mL of triethylamine were charged. Further, 1.0 g of bromopentafluorobenzene was added thereto. The system was then heated to 95 ° C. and stirred for 3-4 hours. Subsequently, after the reaction system was cooled to room temperature, 40 mL of 0.5 mol / L hydrochloric acid was added, and the precipitated solid was collected by filtration. The collected solid was washed with water, washed with toluene, and washed with methanol in this order, and then vacuum-dried at 60 ° C. for 2 hours to obtain 0.44 g of a substantially pure compound (13) (yield) : 62%).

(2) Purification of compound (13) By sublimating and purifying 0.3 g of compound (13) obtained above at 300 ° C. under a reduced pressure of 5.5 to 6.0 × 10 ⁻⁴ Pa. 0.15 g of pure white crystals was obtained. This white crystal was identified as 2,6-bis (pentafluorophenylethynyl) naphthalene (compound (13)) by ¹⁹ F-NMR and ¹ H-NMR analyses. The analysis results are shown below.

¹⁹ F-NMR (282.7 MHz, solvent: THF-d ₈ , reference: CFCl ₃ ) δ (ppm); −137.20 (4F), −153.78 (2F), −162.95 (4F)
¹ H-NMR (300.4 MHz, solvent: THF-d ₈ , standard: TMS) δ (ppm); 7.59 (d, 2H), 8.12 (d, 2H), 8.40 (s, 2H ), 8.58 (s, 2H)

Example 4 Compound (14)
(1) Synthesis of Compound (14) A 50 mL three-necked flask equipped with a thermocouple thermometer and charged with a magnetic stirrer was charged with 0.11 g of 2,6-diethynylanthracene and 28 mg of tetrakis (triphenylphosphine). Palladium (0) and 4.2 mg of copper (I) bromide were charged and the system was purged with nitrogen. Subsequently, 2 mL of toluene and 0.15 mL of triethylamine were charged. Further, 0.4 g of 2-bromoheptafluoronaphthalene was added thereto. The system was then heated to 95 ° C. and stirred for 3-4 hours. Subsequently, after the reaction system was cooled to room temperature, 40 mL of 0.5 mol / L hydrochloric acid was added, and the precipitated solid was collected by filtration. The collected solid was washed with water, washed with toluene, and washed with acetone in this order, and then vacuum-dried at 60 ° C. for 2 hours to obtain 0.21 g of a substantially pure compound (14) (yield) : 59%).

(2) Purification of compound (14) 0.2 g of compound (14) obtained above is purified by sublimation at 400 ° C. under a reduced pressure of 5.5 to 6.0 × 10 ⁻⁴ Pa. 0.12 g of pure white crystals was obtained. This white crystal was identified as 2,6-bis ((heptafluoronaphthalen-2-yl) ethynyl) anthracene (compound (14)) by ¹⁹ F-NMR and ¹ H-NMR analyses. The analysis results are shown below.

¹⁹ F-NMR (282.7 MHz, solvent: THF-d ₈ , standard: CFCl ₃ ) δ (ppm); −113.2 (2F), −134.6 (2F), −144.1 (2F), -144.5 (2F), -149.4 (2F), -153.2 (2F), -156.4 (4F)
¹ H-NMR (300.4 MHz, solvent: THF-d ₈ , standard: TMS) δ (ppm); 7.60 (d, 2H), 8.11 (d, 2H), 8.41 (s, 2H ), 8.59 (s, 2H)

3. Evaluation of physical properties of thin films of fluorine-containing aromatic compounds (Example 5)
A glass substrate having a thickness of 130 nm was fixed to a substrate holder of a vacuum deposition apparatus, and the pressure was reduced to a vacuum degree of 1 × 10 ⁻⁶ Torr (1.33 × 10 ⁻⁴ Pa). Next, the compound (11) synthesized and purified in Example 1 was deposited on a glass substrate so as to have a thickness of 40 nm at a deposition rate of 0.2 nm / second.
It was 6.2 eV when the ionization potential of the vapor-deposited compound (11) thin film was measured using an atmospheric photoelectron spectrometer (AC-3, manufactured by Riken Keiki Co., Ltd.).
Moreover, when the absorption spectrum of the thin film of the deposited compound (11) was measured using a spectrophotometer (UV-3100, manufactured by Shimadzu Corporation), the wavelengths of the absorption maximum were 280 nm and 336 nm, and the longest wavelength side. The wavelength of the absorption edge of was 372 nm.
From these characteristics, the HOMO and LUMO levels of the thin film of Compound (11) were determined to be -6.2 eV and -2.9 eV, respectively. Therefore, it is expected that the thin film of compound (11) has electron transport properties.

Claims (7)

A fluorine-containing aromatic compound represented by the following formula (1).

Ar ^F is a perfluoroaromatic group (however, the fluorine atom in the perfluoroaromatic group may be substituted with a perfluoroalkyl group).
n is an integer of 1 to 4.
Q is an n-valent aromatic group obtained by removing n hydrogen atoms from the structure represented by the following formula (2) (however, the hydrogen atom in the aromatic group has 1 to 8 carbon atoms) It may be substituted with an alkyl group or a fluorine-containing alkyl group having 1 to 8 carbon atoms).

p is an integer of 0-4.   The fluorine-containing aromatic compound according to claim 1, wherein n is 2. The fluorine-containing aromatic compound according to claim 2, wherein Ar ^F is a perfluoroaromatic group selected from the group consisting of a perfluorophenyl group, a perfluoronaphthyl group, and a perfluorobiphenyl group, and p is 0 or 1. The fluorine-containing aromatic compound according to claim 3, wherein p is 0, and the bonding positions of —C≡C—Ar ^{F in} Q are the 2nd and 6th positions. The fluorine-containing aromatic compound according to claim 3, wherein p is 1, and the bonding positions of —C≡C—Ar ^{F in} Q are the 2nd and 6th positions, or the 9th and 10th positions. The fluorine-containing aromatic compound represented by the formula (1) is a compound represented by the following formula (11), a compound represented by the following formula (12), a compound represented by the following formula (13), The fluorine-containing compound according to claim 3, which is a compound selected from the group consisting of a compound represented by the formula (14), a compound represented by the following formula (15), and a compound represented by the following formula (16). Aromatic compounds.

An organic thin film device comprising an organic EL element having an anode, an organic compound layer having a structure of one or more layers, and a cathode on a substrate,
The organic thin film device in which the said organic compound layer contains the fluorine-containing aromatic compound in any one of Claims 1-6.