JP5280853B2 - Novel amino group-containing aromatic compound and sensitizing dye for photoelectric conversion containing the aromatic compound - Google Patents

Abstract

This invention provides an aromatic compound containing an amino group at its end represented by formula (1): (1) wherein R<SUP>1</SUP>, R<SUP>2</SUP>, R<SUP>4</SUP>, and R<SUP>5</SUP> each independently represent a hydrogen atom or an optionally substituted monovalent organic residue, provided that R<SUP>1</SUP> and R<SUP>2</SUP> together may form a ring and R<SUP>1</SUP> and/or R<SUP>2</SUP>, together with X, may form a ring; and R<SUP>3</SUP> represents an anchor group which can be linked to an inorganic porous material having semiconductor properties. By virtue of the specific partial structure, the above aromatic compoud has a broad absorption band in a visible range and can be used as photofunctional materials, particularly sensitizing dyes for photoelectric conversion. In particular, the use of the aromatic compound in dye-sensitized photoelectric conversion batteries can realize the provision of photoelectric conversion batteries having high photoelectric conversion efficiency and high stability.

Description

  The present invention relates to a novel amino group-containing aromatic compound, a sensitizing dye for photoelectric conversion using the same, a photoelectric conversion material using the same, a photoelectric conversion electrode, and a solar cell for photoelectric conversion using the same.

  At present, energy relies heavily on fossil fuels represented by oil, coal, and natural gas, and the depletion of fossil fuels has been greatly screamed in the future. In addition, carbon dioxide emissions inevitably remain a problem when obtaining energy from fossil fuels, and a large burden on the environment is regarded as a problem.

  Recently, solar power generation has attracted more attention due to these concerns. Currently, silicon solar cells using monocrystalline or polycrystalline crystalline silicon or amorphous silicon, or compound semiconductor solar cells using gallium or arsenic are actively used. Although development studies have been made, the current situation is that the versatility is poor because it is still necessary to overcome problems such as manufacturing costs. On the other hand, many solar cells using a photosensitizing dye have been proposed, but there is a problem in that conversion efficiency is low and durability is poor.

  Under such circumstances, there was a report by Graetzel et al. (Non-Patent Document 1) in 1991, and the photoelectric conversion electrode and photoelectric conversion battery using a porous inorganic semiconductor photosensitized with a dye attracted attention. became. The photoelectric conversion element in this report is manufactured using a relatively inexpensive inorganic oxide semiconductor such as titanium oxide, and it is possible to obtain a photoelectric conversion element at a lower cost than a silicon solar battery that is a general-purpose product. Have However, at present, a high photoelectric conversion efficiency cannot be obtained unless it is a ruthenium-based sensitizing dye. Therefore, there is a problem in the stable supply of the dye because of the high cost of the dye and the low number of Clarkes. On the other hand, although organic dyes are being actively studied, they have not been put into practical use because of their low conversion efficiency. Further, although a dye having a specific acrylic acid moiety and a sensitizing dye having an amide derivative have been disclosed (see Patent Document 1, Patent Document 2, and Patent Document 3), it cannot be said to have sufficient performance. It was.

International Publication No. 02/011213 Pamphlet JP 2004-143355 A JP 2005-097561 A Brian O'Regan, Michael Graetzel, “Dye-sensitized colloidal TiO2 film-based, low-cost, high-efficiency solar cell based on citrus oxidised-anti-oxidized solar cell dioxide films ", Nature, UK, October 1991, Vol. 353, pp. 737-740.

  An object of the present invention is to provide a novel amino group-containing aromatic compound having a wide absorption band in the visible region and useful as a sensitizing dye for photoelectric conversion used in a dye-sensitized photoelectric conversion battery. Further, a photoelectric conversion material obtained by connecting an inorganic porous substance exhibiting semiconductor characteristics and the sensitizing dye for photoelectric conversion, a photoelectric conversion electrode formed by laminating the photoelectric conversion material on a transparent electrode, and the photoelectric conversion electrode and electrolyte An object of the present invention is to provide a photoelectric conversion battery comprising a layer and a conductive counter electrode.

As a result of intensive efforts to solve the above problems, the present inventors have found that a compound having a specific partial structure is useful as a sensitizing dye for photoelectric conversion. That is, the present invention provides an aromatic compound containing an amino group at the terminal represented by the following formula (1).
An aromatic compound containing an amino group at the end, represented by the following formula (1).

In the formula (1), R ¹ and R ² are each independently an alkyl group having 1 to 4 carbon atoms . R ³ is a carboxyl group. R ⁴ is a cyano group. R ⁵ is a hydrogen atom. X is a 1,4-phenylene group which may have a substituent . Y is a 1,4-phenylene group which may have a substituent . Z is the following structure in which a cyclic group and a conjugated chain linking group are combined . In the following structure, Y is written on the side bonded to Y.

However, the structure forms a π-conjugated system from X to the anchor group R ³ . At least one of X and Y is a 1,4-phenylene group substituted with one or more fluorine atoms. m is 1. n is an integer of 0 or 1. The double bond in the above formula (1) may give rise to any of the cis-trans isomers.

  Moreover, this invention provides the sensitizing dye for photoelectric conversion characterized by consisting of the aromatic compound containing an amino group at the terminal represented by Formula (1).

  The sensitizing dye for photoelectric conversion may further contain a photosensitizing dye other than the aromatic compound containing an amino group at the terminal represented by the formula (1).

  Moreover, this invention provides the photoelectric conversion material formed by connecting said sensitizing dye for photoelectric conversions, and the inorganic porous substance which shows a semiconductor characteristic.

  Moreover, this invention provides the photoelectric conversion material characterized by using a coadsorbent in combination with said sensitizing dye for photoelectric conversion.

  The inorganic porous material exhibiting the semiconductor characteristics is preferably composed of an inorganic oxide.

  Moreover, this invention provides the photoelectric conversion electrode formed by laminating | stacking said photoelectric conversion material on a transparent electrode.

  The present invention also provides a photoelectric conversion battery comprising the photoelectric conversion electrode, an electrolyte layer, and a conductive counter electrode.

Since the amino group-containing aromatic compound of the present invention has a specific partial structure, it has a wide absorption band in the visible region, and can be used as an optical functional material, particularly as a sensitizing dye for photoelectric conversion. In particular, by using it for a dye-sensitized photoelectric conversion battery, a photoelectric conversion battery having high photoelectric conversion efficiency and high stability can be provided.
In addition, since the energy level of HOMO and LUMO can be easily adjusted by selecting specific substituents, the desired performance should be exhibited in accordance with other materials constituting the dye-sensitized photoelectric conversion battery. Can do.

FIG. 1 is a schematic diagram of a test sample of a photoelectric conversion cell used in the photoelectric conversion test of the example.

Explanation of symbols

1: Glass substrate 2: Transparent electrode layer 3: Platinum electrode layer 4: Titanium oxide porous layer (adsorbed with sensitizing dye for photoelectric conversion)
5: Electrolyte 6: Spacer made of resin film 7: Lead wire for measurement

Hereinafter, the present invention will be described in detail.
In addition, in this specification, when it is described as “may have a substituent”, the substituent is specifically an aliphatic hydrocarbon group, an aromatic hydrocarbon group or an aromatic heterocyclic group. Or a halogen atom, a cyano group, an isocyano group, a thiocyanate group, an isothiocyanate group, a nitro group, a hydroxy group, a mercapto group, an amino group, an amide group, or a monovalent group represented by the following formula (2).

In Formula (2), A ¹ and A ² are each independently O, NH, or S. B is a carbonyl group, a thiocarbonyl group, a sulfinyl group or a sulfonyl group. o and p are each independently 0 or 1. R ⁶ represents a hydrogen atom, a monovalent aliphatic hydrocarbon group, an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent, or a halogen atom, a cyano group, an isocyano group or a thiocyanate group. , Isothiocyanate group, nitro group, hydroxy group, mercapto group, amino group or amide group.

The novel amino group-containing aromatic compound of the present invention is an amino group-containing compound having a specific partial structure, and specifically, a terminal amino group-containing compound represented by the following formula (1).

In the formula (1), R ¹ , R ² , R ⁴ and R ⁵ are each independently a hydrogen atom or a monovalent organic residue which may have a substituent. Here, R ¹ and R ² may jointly form a ring. R ¹ and / or R ² may form a ring together with X. R ³ is an anchor group that can be linked to an inorganic porous material exhibiting semiconductor properties. X is a divalent aromatic hydrocarbon group or a combination of two or more divalent aromatic hydrocarbon groups. The divalent aromatic hydrocarbon group may have a substituent, and two or more rings may be condensed. m is an integer of 1-3. n is an integer of 0 or 1. Y is a divalent aromatic hydrocarbon group. The divalent aromatic hydrocarbon group may have a substituent, and two or more rings may be condensed. Z is a divalent aromatic heterocyclic group, a divalent aromatic hydrocarbon group, a divalent unsaturated hydrocarbon group, or a combination thereof. The divalent aromatic heterocyclic group, divalent aromatic hydrocarbon group and divalent unsaturated hydrocarbon group may have a substituent, and the divalent aromatic heterocyclic group and divalent aromatic In the aromatic hydrocarbon ring group, two or more rings may be condensed. However, the structure forms a π-conjugated system from X to the anchor group R ³ . Further, at least one of X and Y is a divalent aromatic hydrocarbon group substituted with one or more fluorine atoms. The double bond in formula (1) may give rise to any of the cis-trans isomers.

First, X in the formula (1) will be described. X represents a divalent aromatic hydrocarbon group or a combination of two or more divalent aromatic hydrocarbon groups. The divalent aromatic hydrocarbon group may have a substituent, and two or more rings may be condensed. Moreover, when it has a substituent, two or more substituents may combine with each other to form a ring. R ¹ and / or R ² may form a ring together with X. Specifically, the combination of two or more divalent aromatic hydrocarbon groups is a structure in which two or more divalent aromatic hydrocarbon groups are directly connected.

  Examples of the divalent aromatic hydrocarbon group include a phenylene group, a naphthylene group, an anthrylene group, and a phenanthrylene group, each of which may have a substituent. Examples of the group having a structure in which a divalent aromatic hydrocarbon group is directly connected include a biphenylene group and a terphenylene group. X is particularly preferably a 1,4-phenylene group which may have a substituent.

  Y is a divalent aromatic hydrocarbon group which may have a substituent. The divalent aromatic hydrocarbon group may have a substituent. The divalent aromatic hydrocarbon group may have a monocyclic structure or a condensed ring structure in which two or more rings are condensed. Examples of the divalent aromatic hydrocarbon group include a phenylene group, a naphthylene group, an anthrylene group, a phenanthrylene group, and the like, and a 1,4-phenylene group is particularly preferable.

Z in formula (1) is a divalent aromatic heterocyclic group, a divalent aromatic hydrocarbon group, a divalent unsaturated hydrocarbon group, or a combination thereof. The divalent aromatic heterocyclic group, divalent aromatic hydrocarbon group and divalent unsaturated hydrocarbon group may have a substituent, and the divalent aromatic heterocyclic group and divalent aromatic In the aromatic hydrocarbon ring group, two or more rings may be condensed. However, the structure forms a π-conjugated system from X to the anchor group R ³ .

  Specific examples of combinations of cyclic groups include a structure in which two or more divalent aromatic heterocyclic groups are directly connected, a structure in which two or more divalent aromatic hydrocarbon groups are directly connected, and one or more A structure in which a divalent aromatic heterocyclic group of 1 and one or more divalent aromatic hydrocarbon groups are directly connected, and two or more divalent aromatic heterocyclic groups are formed by a divalent unsaturated hydrocarbon group A linked structure, a structure in which two or more divalent aromatic hydrocarbon groups are linked by a divalent unsaturated hydrocarbon group, or one or more divalent aromatic heterocyclic groups and one or more Examples thereof include a structure in which a divalent aromatic hydrocarbon group is linked by a divalent unsaturated hydrocarbon group. However, in the case of a structure linked by a divalent unsaturated hydrocarbon group, the π electrons of the divalent aromatic heterocyclic group and aromatic hydrocarbon group and the π electrons of the divalent unsaturated hydrocarbon group are It is a conjugated structure.

Examples of the divalent aromatic heterocyclic group include a thienylene group and a thienothienylene group, each of which may have a substituent, preferably a 2,5-thienylene group and a 2,5-thienothienylene group.
Examples of the divalent aromatic hydrocarbon group include a phenylene group, a naphthylene group, an anthrylene group, and a phenanthrylene group, each of which may have a substituent. Examples of the group having a structure in which a divalent aromatic hydrocarbon group is directly connected include a biphenylene group and a terphenylene group.
Examples of the divalent unsaturated hydrocarbon group include “—CH═CH—”, “—CH═CH—CH═CH—”, “—CH═CH—CH═CH—CH═CH—”, “—CH═ A conjugated chain linking group such as “CH—C≡C—” or a cyclic linking group having an unsaturated bond such as 1-cyclohexene-1,2-ylene and 1-cyclopentene-1,2-ylene, and the chain linking group And a structure in which a cyclic linking group is combined.

The terminal amino group-containing aromatic compound of the present invention represented by the formula (1) is suitable as a sensitizing dye for photoelectric conversion used in a dye-sensitized photoelectric conversion battery.
The solar radiation spectrum reaching the ground is scattered or absorbed by the upper atmosphere surrounding the earth, and a distribution is seen at about 300 to 3000 nm. Here, in the dye-sensitized photoelectric conversion battery, it is considered that the absorption wavelength region in which sunlight can be converted into electric energy is effective in the range of 300 to 1200 nm due to the influence of the semiconductor electrode potential and the oxidation-reduction potential of the electrolyte. Furthermore, the irradiance of sunlight is large mainly in the visible region, and the energy in the visible region of 400 to 800 nm corresponds to 55% of the total solar energy.
Therefore, solar energy can be efficiently used by using a dye having a wide absorption band in the visible region as a sensitizing dye for photoelectric conversion for a dye-sensitized photoelectric conversion battery.

Further, the energy level of the highest occupied orbit (hereinafter abbreviated as HOMO) and the lowest unoccupied orbit (hereinafter abbreviated as LUMO) of the dye greatly affects the performance of the dye-sensitized solar cell. The HOMO energy level (one-electron oxidation potential) of the dye is required to be lower than the redox potential of the electron transfer agent in the electrolyte, and the LUMO energy level (one-electron reduction potential) of the dye. Is required to be higher than a semiconductor conduction band. Since the optimal energy level has a large balance between the pigment and the individual components that are affected, it is considered that an appropriate energy difference from each pigment is necessary (Ashraful Islam, Hideki Sugihara, Hidenori Arakawa, "molecular design of ruthenium polypyridyl photosensitizers for good nanocrystalline titania solar cell efficiency (molecular design of ruthenium (II) polypyridyl photosensitizers for efficient nanocrystalline TiO 2 solar cell) ", Journal of Photochemistry and Photobiology A: See Chemistry).

Originally, energy levels such as HOMO and LUMO greatly depend on the skeleton. To tune the energy level to the optimum position, change the skeleton or extend or shorten the π-conjugated system. become. In general, it is known that when the π-conjugated system is lengthened, the HOMO energy level increases and the LUMO energy level decreases. However, there is a limit to tuning the energy level to an optimum position only by expanding or contracting the HOMO or LUMO energy level of the dye by the length of the conjugated system.
As a method for designing the structure of a dye satisfying these requirements, it can be proposed to introduce an appropriate number of fluorine atoms into an appropriate position in the compound represented by the formula (1). Thereby, energy levels such as HOMO and LUMO can be tuned. These compounds are suitable as sensitizing dyes for dye-sensitized photoelectric conversion batteries.

  X and Y in the formula (1) are preferably aromatic hydrocarbon groups which may have a substituent. As the aromatic hydrocarbon group, a phenylene group, a naphthylene group or an anthrylene group capable of conjugating from a terminal amino group to an anchor group is preferable, and a 1,4-phenylene group is particularly preferable. Particularly preferred as X and Y is a 1,4-phenylene group substituted with a fluorine atom. More preferably, the 1,4-phenylene group is substituted with 1 or 2 fluorine atoms. The reason why these groups are preferable as X and Y is that the starting materials for synthesis are easily available. In addition, by introducing fluorine atoms into X and Y aromatic hydrocarbon groups, there is an effect of changing the HOMO energy level and LUMO energy level of the dye, and the fluorine atom substitution position and the number of substitutions are appropriately selected. Thus, the HOMO and LUMO energy levels can be adjusted. The HOMO and LUMO energy levels can be easily known by performing cyclic voltammetry (hereinafter abbreviated as “CV”), which is one of electrochemical measurement methods. The HOMO energy level of the substance corresponds approximately to the one-electron oxidation potential, and the LUMO energy level approximately corresponds to the one-electron reduction potential. By introducing an appropriate number of fluorine atoms into the compound represented by the formula (1) at an appropriate position, the value of the one-electron oxidation potential and the one-electron reduction potential can be shifted to an optimum value. It becomes.

Z in the formula (1) is a combination of a ring group such as a phenylene group, a thienylene group, and a thienothienylene group that may have a substituent, or a ring group such as the following and a conjugated chain linking group. A structure or the like is preferable. In the following structure, Y is written on the side bonded to Y. (Fn) means that one or more fluorine atoms may be substituted. Each ring group may have a substituent, but preferably a hydrogen atom or a fluorine atom. The reason why these groups are preferable as Z is that it is easy to expand the absorption region and adjust the absorption maximum, and the raw materials are easily available and synthesis is easy.

Next, R ¹ , R ² , R ⁴ and R ⁵ in the formula (1) will be described.
R ¹ , R ² , R ⁴ and R ⁵ are each independently a monovalent organic residue optionally having a hydrogen atom or a substituent. Here, R ¹ and R ² may jointly form a ring. R ¹ and / or R ² may form a ring together with X.

Specific examples of the monovalent organic residue represented by R ¹ , R ² , R ⁴ and R ⁵ include an aliphatic hydrocarbon group, an aromatic hydrocarbon group or an aromatic group each optionally having a substituent. Examples include a heterocyclic group, a halogen atom, a cyano group, an isocyano group, a thiocyanate group, an isothiocyanate group, a nitro group, a hydroxy group, a mercapto group, an amino group, an amide group, or a group represented by the following formula (2). .

In Formula (2), A ¹ and A ² are each independently O, NH, or S. B is a carbonyl group, a thiocarbonyl group, a sulfinyl group or a sulfonyl group. o and p are each independently 0 or 1. R ⁶ represents a hydrogen atom, a monovalent aliphatic hydrocarbon group, an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent, or a halogen atom, a cyano group, an isocyano group or a thiocyanate group. , Isothiocyanate group, nitro group, hydroxy group, mercapto group, amino group or amide group.

  Here, the monovalent aliphatic hydrocarbon group means a monovalent aliphatic hydrocarbon group having 1 to 40 carbon atoms, and may be any of a linear structure, a branched structure, or a cyclic structure, It may have an unsaturated bond. The monovalent aliphatic hydrocarbon group may have a substituent, and one or more carbon atoms may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom. Specific examples of the monovalent aliphatic hydrocarbon group include an alkyl group having 1 to 30 carbon atoms, an alkenyl group, an alkynyl group, a cycloalkyl group, and an alkoxy group.

  More specifically, as the monovalent aliphatic hydrocarbon group, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, 1- An alkyl group having 1 to 8 carbon atoms such as a pentyl group, 1-hexyl group, 1-heptyl group, 1-octyl group, 2-ethyl-1-hexyl group; 1-propenyl group, isopropenyl group, allyl group, 1- C2-C4 alkenyl group such as butenyl group, 2-butenyl group, 3-butenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group; ethynyl group, 1-propynyl group, 2- C2-C4 alkynyl group such as propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-methyl-3-propynyl group; cyclopropyl group, cyclobutyl , A cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecanyl group, a saturated cycloalkyl group having 3 to 10 carbon atoms; a 2-cyclopenten-1-yl group, a 2-cyclohexen-1-yl group, etc. Examples thereof include unsaturated cycloalkyl groups having 3 to 7 carbon atoms.

  Examples of the monovalent aromatic hydrocarbon group include an aromatic hydrocarbon group having a monovalent monocyclic structure or a condensed ring structure, or a monovalent ring assembly aromatic hydrocarbon group. Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a triphenyl group, and a pyrenyl group. Further, the monovalent aromatic hydrocarbon group may be bonded to the skeleton portion of the formula (1) through an oxygen atom, a sulfur atom, or a nitrogen atom. Examples thereof include a phenoxy group and a naphthyloxy group.

  Preferred monovalent aromatic hydrocarbon groups are a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, an o-anisoyyl group, an m-anisoyyl group, a p-anisoyyl group, a 1-naphthyl group, 2 -Monovalent aromatic hydrocarbon groups having 6 to 14 carbon atoms such as naphthyl group and 9-phenanthryl group.

  Examples of the monovalent aromatic heterocyclic group include an aromatic heterocyclic group having a monovalent monocyclic structure or a condensed ring structure, and a monovalent ring assembly aromatic heterocyclic group. Specifically, 2-furyl group, 3-furyl group, 2-thienyl group, 3-thienyl group, 2-selenyl group, 3-selenyl group, 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, 2-quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group, 1-isoquinolyl group, 2-quinoxalyl group, 2-benzofuryl group, 2-benzothienyl group, 2-thienothienyl group, 3-thienothienyl group, 2-selenoselenyl group, 3-selenoselenyl group, 2-thiazoyl group, 2-thiazothiazoyl group Etc.

  Preferred monovalent aromatic heterocyclic groups include carbon numbers such as 2-thienyl group, 2-selenyl group, 2-benzothienyl group, 2-benzoselenyl group, 2-thienothienyl group, 2-selenoselenyl group, and 2-dithienyl group. Examples include 4 to 12 aromatic heterocyclic groups.

Examples of the aliphatic hydrocarbon group in which R ¹ and R ² jointly form a cyclic structure include a divalent linking group. Preferred examples of the divalent linking group include saturated alkylene groups having 4 to 6 carbon atoms such as a tetramethylene group, a pentamethylene group, and a hexamethylene group. For example, in the case of a pentamethylene group, the ring formed by R ¹ and R ² and the nitrogen atom of the amine moiety of formula (1) forms a piperidine ring.

For example, when the aliphatic hydrocarbon group in which R ¹ and R ² jointly form a cyclic structure is a pentamethylene group, and the carbon atom is substituted with an oxygen atom, R ¹ and R ² and the formula ( The ring formed by the nitrogen atom of the amine moiety of 1) forms a morpholine ring or the like.

Examples of the aromatic hydrocarbon group in which R ¹ and R ² jointly form a cyclic structure include a divalent linking group consisting of an aromatic hydrocarbon group having a monocyclic structure or a condensed ring structure, or a ring assembly aromatic hydrocarbon group And a divalent linking group. Specific examples of such a divalent linking group include a 2,2′-biphenylene group, a —Ph—S—Ph— group, a 4,5-phenanthrylene group, and the like, preferably 2,2′- Biphenylene group is mentioned.

Examples of the aromatic heterocyclic group in which R ¹ and R ² jointly form a cyclic structure include a divalent linking group composed of an aromatic heterocyclic group having a monocyclic structure or a condensed ring structure, or a ring assembly aromatic heterocyclic group And a divalent linking group. Specific examples of such a divalent linking group include a 3,3′-bithienylene group.

As R ¹ and R ² , an alkyl group having 1 to 4 carbon atoms and a monovalent aromatic hydrocarbon group having 6 to 14 carbon atoms are preferable, and an alkyl group having 1 to 4 carbon atoms is preferable. Particularly preferred.

R ⁴ and R ⁵ are preferably a hydrogen atom, a halogen atom, or a monovalent organic residue having 1 to 20 carbon atoms. Here, the monovalent organic residue is preferably substituted. R ₄ and R ₅ are particularly preferably a hydrogen atom or an electron withdrawing group.

The term “electron-withdrawing group” as used herein means a group having a Hammett's substituent constant σ greater than zero. Specific examples of the electron withdrawing group of R ⁴ and R ⁵ include cyano group, carboxyl group, acyl group, formyl group, aryloxycarbonyl group, alkyloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, alkylsulfinyl group. , Arylsulfinyl group, nitro group, perfluoroalkyl group and the like. However, the electron withdrawing group is not limited to these.

  Examples of the acyl group include an acetyl group, a propionyl group, a pivaloyl group, an acryloyl group, a methacryloyl group, a benzoyl group, a toluoyl group, and a cinnamoyl group.

  Examples of the aryloxycarbonyl group include a phenoxycarbonyl group, a naphthyloxycarbonyl group, and a 4-fluorophenyloxycarbonyl group.

  Examples of the alkylsulfonyl group include a mesyl group, an ethylsulfonyl group, a propylsulfonyl group, a trifluorosulfonyl group, and a nonafluoro-t-butylsulfonyl group.

  Examples of the arylsulfonyl group include a benzenesulfonyl group and a toluenesulfonyl group.

  Examples of the alkylsulfinyl group include a methylsulfinyl group, an ethylsulfinyl group, and a propylsulfinyl group.

  Examples of the arylsulfinyl group include a phenylsulfinyl group and a toluylsulfinyl group.

  The perfluoroalkyl group is an alkyl group in which all hydrogen atoms substituted on carbon atoms are fluorine-substituted, and the number of carbon atoms is preferably 1-20. An oxygen atom or a sulfur atom may be inserted into the perfluoroalkyl group.

Among these, as R ⁴ , a cyano group is preferable in view of ease of synthesis and electron withdrawing strength. R ⁵ is preferably a hydrogen atom or a cyano group.

R ³ is an anchor group that can be linked to an inorganic porous material exhibiting semiconductor properties. As the inorganic porous material exhibiting such semiconductor characteristics, specifically, particles in which inorganic oxides exhibiting semiconductor characteristics such as titanium oxide, tin oxide, and zinc oxide are made porous are used. Therefore, the anchor group widely includes groups that can be connected to the porous inorganic oxide particles. Such an anchor group is preferably a carboxyl group, a phosphoric acid group, a sulfonic acid group or the like. Among these, a carboxyl group is particularly preferable because it can be easily connected to porous inorganic oxide particles.
In addition, the said carboxyl group, a sulfonic acid group, a phosphoric acid group, etc. may combine with a cation and form the salt for the purpose of improving solubility. Examples of the cation capable of forming a salt include ammonium ion, alkali metal ion, and alkaline earth metal ion. Examples of ammonium ions include tetraalkylammonium ions typified by tetramethylammonium ions. Examples of the alkali metal ion include sodium ion, potassium ion, lithium ion, and the like. Examples of alkaline earth metal ions include magnesium ions and calcium ions.

  M in Formula (1) is an integer of 1-3. M is preferably 1 in view of ease of synthesis and stability of the compound.

N in Formula (1) is an integer of 0 or 1. In the case of 0, it means that Z does not exist, and Y is directly connected to the carbon atom bonded to R ⁵ . 0 is preferable from the viewpoint of ease of synthesis, and 1 is preferable from the viewpoint of elongation of the conjugated system.

  Specific examples of the aromatic compound containing an amino group at the terminal of the present invention represented by the formula (1) are shown below. However, these are for illustrative purposes, and the aromatic compound containing an amino group at the end of the present invention is not limited thereto.

Hereinafter, specific examples of the aromatic compound containing an amino group at the terminal of the present invention represented by the formula (1) are shown below. However, these are for illustrative purposes, and the aromatic compound containing an amino group at the end of the present invention is not limited thereto.
For convenience, the X, Y, and Z ring groups of formula (1) are omitted and described as follows. The direction of the ring group is the same as that applied to the formula (1). For example, in the case of X, the left side is bonded to the nitrogen atom bonded to R ₁ R ₂ , and the right side is bonded to the carbon atom of the group represented by (CH═CH) _m .
In the structural formula, when Fn is described, it means that the cyclic group is substituted with one or more fluorine atoms.

  Moreover, structural formula was described before each table | surface as a skeleton structure of the compound described by the following table | surface.

The sensitizing dye for photoelectric conversion of the present invention is characterized by comprising an aromatic compound containing an amino group at the terminal represented by the formula (1). That is, the sensitizing dye for photoelectric conversion of the present invention is the one using an aromatic compound having an amino group at the terminal represented by the formula (1) of the present invention as a sensitizing dye for photoelectric conversion.
The sensitizing dye for photoelectric conversion of the present invention is another photosensitizing dye in order to compensate for sunlight absorption in a region that cannot be covered by an aromatic compound containing an amino group at the terminal represented by the formula (1). May further be included.
Examples of other sensitizing dyes used for such purposes include cyanine dyes, merocyanine dyes, mercurochrome dyes, xanthene dyes, porphyrin dyes, phthalocyanine dyes, azo dyes, and coumarin dyes. Metal complex dyes such as ruthenium complex dyes can also be used as other sensitizing dyes of the present invention.

  The photoelectric conversion material of the present invention is formed by connecting the above-described sensitizing dye for photoelectric conversion of the present invention and an inorganic porous material exhibiting semiconductor characteristics via an anchor group. Examples of the inorganic porous material used when forming the photoelectric conversion material include titanium oxide, tin oxide, zinc oxide, niobium oxide, indium oxide, tungsten oxide, and tantalum oxide. These may be used in combination of two or more inorganic compounds. Among these, preferable examples include titanium oxide and tin oxide, and titanium oxide is particularly preferable.

The photoelectric conversion electrode of the present invention is formed by laminating the photoelectric conversion material of the present invention obtained by the above procedure on a transparent electrode. Here, the transparent electrode can be obtained by forming a transparent conductive film on a transparent substrate. Examples of the transparent base material include a glass substrate and a resin substrate. Examples of the glass include quartz glass, soda lime glass, borosilicon glass, and lead glass. Examples of the resin substrate include polyethylene terephthalate and polyethylene naphthalate.
As a method of forming a conductive film on the surface of a transparent substrate, a method of forming a metal oxide (ITO) composed of indium oxide and tin oxide on the surface of the substrate by vapor deposition or the like, or fluorine on tin oxide The method etc. which form a film | membrane by doping is mentioned.

The photoelectric conversion electrode of the present invention is formed by laminating the photoelectric conversion material of the present invention obtained by the above procedure on a transparent electrode. Here, regarding the method of laminating the photoelectric conversion material on the transparent electrode and the transparent electrode, for example, as the method of laminating the photoelectric conversion material of the present invention on the transparent electrode, the layer of the inorganic porous material is disposed on the transparent electrode. And a method of adsorbing a sensitizing dye here. In order to produce a layer of an inorganic porous material on a transparent electrode, the inorganic porous material is dispersed by adding an appropriate solvent, polymer, or appropriate additive, and a paste is formed on the transparent electrode. The method of drying or sintering after apply | coating is mentioned. A commercially available product may be used as the paste of the inorganic porous material. Examples of the solvent to be dispersed include water, alcohol solvents, amine solvents, ketone solvents, and hydrocarbon solvents. Examples of the coating method include a spin coating method, a screen printing method, a dipping method, and a method using a squeegee. As the drying and baking temperature of the substrate coated with the inorganic porous material paste, the lower limit is a temperature at which the solvent can be removed, and the upper limit is a temperature at which dissolution of the substrate does not occur. It is preferable that the temperature is such that improved adhesion to the transparent electrode can be obtained.
Examples of the method for adsorbing the sensitizing dye include a method in which the sensitizing dye is dissolved or dispersed in an appropriate solvent, and the electrode substrate on which the layer of the inorganic porous material is formed is immersed in this solution or dispersion. Examples of the solvent for dissolving or dispersing the sensitizing dye include water, alcohol solvents, amine solvents, ketone solvents, hydrocarbon solvents and the like. Alcohols are preferable, and ethanol is particularly preferable.

The photoelectric conversion battery of the present invention is formed by combining the above-described photoelectric conversion electrode with a conductive counter electrode via an electrolyte layer.
The electrolyte layer used for the photoelectric conversion battery is preferably composed of an electrolyte, a medium, and an additive. Regarding these constituent elements, for example, examples of the electrolyte include a liquid electrolyte obtained by adding a redox pair to a solvent, a polymer gel electrolyte, and a solid electrolyte. Examples of the liquid electrolyte solvent include nitrile solvents, carbonate solvents, glycol solvents, water, and the like, and acetonitrile and methoxyacetonitrile are particularly preferable. Examples of the redox pair include a halogen redox pair, and an iodine redox pair is particularly preferable. The redox couple of iodine can be obtained by a combination of iodine and iodide ions. Examples of the raw material for iodide ions include metal iodide salts and quaternary ammonium salts, and particularly lithium iodide and the like. Similarly, redox couples can be obtained for other halogen compounds such as bromine.

  Examples of the conductive counter electrode include a metal electrode deposited with a metal such as platinum, rhodium, ruthenium, and indium, a carbon electrode, a conductive polymer electrode, or a composite electrode thereof.

  The assembly of the battery is obtained by arranging the transparent electrode and the counter electrode through a spacer or the like so as to sandwich the laminated photoelectric conversion material and filling the electrolyte therebetween. In order to prevent leakage of the electrolytic solution, the periphery of the photoelectric conversion element may be sealed. Examples of the sealing material include polymer adhesives.

In addition, a compound called “co-adsorbent” or the like can be used together with the sensitizing dye for photoelectric conversion of the present invention. The co-adsorbent increases the photoelectric conversion efficiency by adsorbing to the inorganic porous material together with the sensitizing dye.
The sensitizing dye for photoelectric conversion of the present invention is connected to an inorganic porous material exhibiting semiconductor characteristics via an anchor group, and this “connection” is almost synonymous with the above “adsorption”.

  Examples of coadsorbents include steroid compounds having carboxyl groups and sulfonic acid groups, especially cholic acid derivatives (cholic acid, deoxycholic acid, chenodeoxycholic acid, taurochenodeoxycholic acid, lysocholic acid, ursodeoxycholic acid, dehydrocholic acid) And metal salts thereof, amines (pyridine, 4-t-butylpyridine, polyvinylpyridine, etc.), quaternary ammonium salts (tetrabutylammonium iodide, tetrahexylammonium iodide, etc.), and the like. As the coadsorbent, cholic acid derivatives are preferable, and deoxycholic acid is particularly preferable.

  Examples of how to use the co-adsorbent include adding after adsorbing (linking) the dye to the inorganic porous material, adding to the electrolyte layer, and the like. It is not limited to this as long as it is adsorbed (linked) to a substance. Although the amount used varies depending on the dye, high photoelectric conversion efficiency can be expected by adding about 10 mM to 60 mM.

  Hereinafter, the present invention will be specifically described based on examples. However, the present invention is not limited to these examples. Hereinafter, the compound represented by the formula (A) is referred to as a compound (A), and the compounds represented by other formulas are also described in the same manner.

Example 1 Synthesis of Compound (A)

Synthesis of Compound (A-1) In a 500 mL four-necked flask equipped with a cooling tube, thermometer, and magnetic rotor, 7 g of p-fluorobenzaldehyde (manufactured by Wako Pure Chemical Industries, Ltd.) and di (n-butyl) amine ( 19 g of Wako Pure Chemical Industries, Ltd.) and 34 g of potassium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) and 150 mL of anhydrous dimethylformamide (Wako Pure Chemical Industries, Ltd.) as a solvent were charged, and at 80 ° C. for 10 hours under a nitrogen stream. The mixture was heated and stirred. After cooling, the solid was filtered off, and the solvent was distilled off and concentrated to obtain 9.3 g of product. It was confirmed by ¹ H-NMR measurement that the product was compound (A-1) (the following formula).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) δ 0.97 (t, J = 7.4 Hz, —CH ₃ , 6H), 1.31-1.43 (m, —CH ₂ —, 4H), 1 _{.54-1.64 (m, -CH 2 -,} 4H), 3.34 (t, J = 7.8Hz, N-CH 2 -, 4H), 6.68 (d, J = 9.0Hz, Benzene ring hydrogen, 2H), 7.69 (m, benzene ring hydrogen, 2H), 9.68 (d, -C (= O) -H, 1H)

Synthesis of Compound (A-2) In a 500 mL four-necked flask equipped with a cooling tube, a thermometer, and a magnetic rotor, 53.81 g of 4-bromo-2-fluorobenzyl bromide (manufactured by Wako Pure Chemical Industries, Ltd.), 36.77 g of triethyl phosphite (manufactured by Kanto Chemical Co., Inc.) and 200 mL of acetonitrile (manufactured by Wako Pure Chemical Industries, Ltd.) were added, and the mixture was heated to reflux for 9 hours under a nitrogen stream. After cooling, the solvent and the like were distilled off to obtain 66.36 g of a product. ¹ H-NMR measurement confirmed that the product was compound (A-2). In the following formula, “Et” represents an ethyl group.

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) δ 1.29 (m, —CH ₃ , 6H), 3.14 (m, Ar—CH ₂ —P, 2H), 4.06 (m, —O—) _{CH 2 -, 4H), 7.26} (m, benzene ring hydrogen, 3H)

Synthesis of Compound (A-3) In a 300 mL four-necked flask equipped with a condenser, thermometer, magnetic rotor, and dropping funnel, 4.00 g of Compound (A-1) obtained in the above procedure and Compound (A -2) Put 5.85 g in 120 mL of dehydrated tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.), then 2.90 g of tert-butoxy potassium (manufactured by Wako Pure Chemical Industries, Ltd.) and 18-crown-6 (Kanto Chemical) 0.63 g) was added in two portions and stirred at room temperature for 180 minutes.
After completion of the reaction, 1N hydrochloric acid was added to stop the reaction, and the organic phase was washed with water. After separation and drying, the solvent was distilled off under reduced pressure and concentrated, followed by separation and purification by silica gel chromatography to obtain 6.02 g of product. ¹ H-NMR measurement confirmed that the product was compound (A-3).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) δ 0.96 (t, J = 7.2 Hz, —CH ₃ , 6H), 1.30 to 1.42 (m, —CH ₂ —, 4H), 1 _{.53-1.63 (m, -CH 2 -,} 4H), 3.29 (t, J = 7.5Hz, N-CH 2 -, 4H), 6.61 (d, J = 9.0Hz, Benzene ring hydrogen, 2H), 6.92 (d, J = 16.5 Hz, olefin hydrogen, 1H), 7.07 (d, J = 16.5 Hz, olefin hydrogen, 1H), 7.18-7.24. (M, benzene ring hydrogen, 2H), 7.37 (d, J = 8.7 Hz, benzene ring hydrogen, 2H), 7.43 (t, J = 8.3 Hz, benzene ring hydrogen, 1H)

Synthesis of Compound (A-4) In a 100 mL four-necked flask equipped with a cooling tube, a thermometer, and a magnetic rotor, 6.00 g of Compound (A-3) obtained by the above procedure and dehydrated tetrahydrofuran (Wako Pure Chemical Industries, Ltd.) 75 mL of Kogyo Co., Ltd. was added, and after cooling to −78 ° C. under a nitrogen stream, 11.7 mL of n-butyllithium-hexane solution (manufactured by Kanto Chemical Co., Inc.) (1.52 mol / L) was added. After stirring at −78 ° C. for 15 minutes, 2.35 g of 1-formylpiperidine (Tokyo Chemical Industry Co., Ltd.) was added. After stirring for 1 hour, the temperature was raised to room temperature, and 1N hydrochloric acid was added to stop the reaction. The organic phase was separated and washed with water. After drying, the solvent was distilled off under reduced pressure and concentrated, followed by separation and purification by silica gel chromatography to obtain 2.62 g of product. ¹ H-NMR measurement confirmed that the product was compound (A-4).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 0.97 (t, J = 7.4 Hz, —CH ₃ , 6H), 1.31-1.43 (m, —CH ₂ —, 4H), 1 _{.54-1.64 (m, -CH 2 -,} 4H), 3.31 (t, J = 7.7Hz, N-CH 2 -, 4H), 6.63 (d, J = 9.0Hz, Benzene ring hydrogen, 2H), 7.03 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.25 (d, J = 16.5 Hz, olefin hydrogen, 1H), 7.42 (d, J = 9.0 Hz, benzene ring hydrogen, 2H), 7.51 to 7.75 (m, benzene ring hydrogen, 3H), 9.91 (s, -CHO, 1H).

Synthesis of Compound (A-5) 1. Compound (A-4) obtained by the above procedure in a 100 mL four-necked flask equipped with a Dean-Stark fractionator equipped with a condenser, a thermometer, and a magnetic rotor. 00 g, 1.67 g of tert-butyl cyanoacetate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.78 g of morpholine (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in 60 mL of toluene and heated to reflux until the reaction was completed. After completion of the reaction, the reaction mixture was cooled to room temperature, and the solvent and the low boiling point reactant were distilled off and concentrated under reduced pressure, followed by separation and purification by silica gel chromatography to obtain 1.31 g of product. ¹ H-NMR measurement confirmed that the product was compound (A-5).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 0.97 (t, J = 7.4 Hz, —CH ₃ , 6H), 1.31-1.43 (m, —CH ₂ —, 4H), 1 _{.56-1.62 (m, -CH 2 -,} - C (CH 3) 3, 13H), 3.31 (t, J = 7.5Hz, N-CH 2 -, 4H), 6.63 ( d, J = 9.0 Hz, benzene ring hydrogen, 2H), 7.03 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.25 (d, J = 16.2 Hz, olefin hydrogen, 1H) 7.42 (d, J = 9.0 Hz, benzene ring hydrogen, 2H), 7.64-7.72 (m, benzene ring hydrogen, 3H), 8.08 (s, (CN) C = CH, 1H)

Synthesis of Compound (A) 1.30 g of Compound (A-5) obtained by the above procedure and acetic acid (Wako Pure Chemical Industries, Ltd.) were added to a 100 mL four-necked flask equipped with a cooling tube, a thermometer, and a magnetic rotor. 50 mL) was added, and 5.04 g of 48% hydrobromic acid was added and stirred at room temperature. After completion of the reaction, the reaction mixture was poured into 30 mL of ion exchange water and extracted twice with 600 mL of methyl tert-butyl ether (manufactured by Gordo Solvent Co., Ltd.). The extract was washed once with aqueous ammonia and twice with water, and the solvent was distilled off under reduced pressure and concentrated to obtain 0.94 g of the product. It was confirmed by ¹ H-NMR measurement that the product was a compound (A) containing an amino group at the end of the present invention.
¹ H-NMR (300 MHz, DMSO-d ₆ ) 0.92 (t, J = 7.2 Hz, —CH ₃ , 6H), 1.27-1.39 (m, —CH ₂ —, 4H), 1 _{.47-1.56 (m, -CH 2 -,} 4H), 3.08-3.55 (m, N-CH 2 -, 4H), 6.65 (d, J = 9.0Hz, benzene ring Hydrogen, 2H), 7.01 (d, J = 16.5 Hz, olefin hydrogen, 1H), 7.23 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.46 (d, J = 9 0.0 Hz, benzene ring hydrogen, 2H), 7.86-7.96 (m, benzene ring hydrogen, 3H), 8.28 (s, (CN) C = CH, 1H)

Example 2 Synthesis of Compound (B)

Synthesis of Compound (B-1) In a 500 mL four-necked flask equipped with a condenser, thermometer, and magnetic rotor, 7 g of 3,4-difluorobenzaldehyde (Tokyo Chemical Industry Co., Ltd.) and di (n-butyl) amine 19 g (manufactured by Wako Pure Chemical Industries, Ltd.) and 34 g of potassium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) and 150 mL of anhydrous dimethylformamide (manufactured by Wako Pure Chemical Industries, Ltd.) as a solvent were charged at 10 ° C. under a nitrogen stream at 80 ° C. The mixture was heated and stirred for an hour. After cooling, the solid was filtered off, and the solvent was distilled off and concentrated to obtain 9.3 g of product. It was confirmed by ¹ H-NMR measurement that the product was compound (B-1) (the following formula).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 0.92 (t, J = 7.2 Hz, —CH ₃ , 6H), 1.25 to 1.45 (m, —CH ₂ —, 4H), 1 _{.50-1.65 (m, -CH 2 -,} 4H), 4.09 (t, J = 6.3Hz, N-CH 2 -, 4H), 6.77 (t, J = 8.7Hz, Benzene ring hydrogen, 1H), 7.40-7.55 (m, benzene ring hydrogen, 2H), 9.71 (d, -C (= O) -H, J = 2.1 Hz, 1H)

Synthesis of Compound (B-2) In the procedure for synthesizing Compound (A-2) described above, 4-bromo-2-fluorobenzyl bromide was replaced with 2,3-difluorobenzyl bromide (manufactured by AMAX Co.). Performed a similar procedure to give 10.68 g of product. It was confirmed by ¹ H-NMR measurement that the product was compound (B-2) (the following formula).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 1.28 (t, J = 7.2 Hz, —CH ₃ , 6H), 3.22 (dd, J = 1.2, 21.6 Hz, Ar—CH ₂ -P (= O), 2H), 4.06 (q, J = 7.2 Hz, -O-CH ₂ -CH ₃ , 2H), 4.09 (q, J = 7.2 Hz, -O- _{CH 2 -CH 3, 2H),} 7.02-7.13 (m, benzene ring hydrogen, 3H)

Synthesis of Compound (B) In the procedure for synthesizing the above compound (A-3), the compounds (A-1) and (A-2) were synthesized as the compounds (B-1) and (B-2) synthesized by the above procedure. ) Was carried out in the same manner as in Example 1 except that 0.53 g of the product was obtained. It was confirmed by ¹ H-NMR measurement that the product was compound (B).
¹ H-NMR (300 MHz, DMSO-d ₆ ) 0.88 (t, J = 7.4 Hz, —CH ₃ , 6H), 1.22-1.34 (m, —CH ₂ —, 4H), 1 _{.42-1.52 (m, -CH 2 -,} 4H), 3.22 (t, J = 7.5Hz, N-CH 2 -, 4H), 6.93 (t, J = 8.6Hz, Benzene ring hydrogen, 1H), 7.16 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.33 (d, J = 8.4 Hz, benzene ring hydrogen, 2H), 7.48 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.74-7.81 (m, benzene ring hydrogen, 1H), 7.97-8.04 (m, benzene ring hydrogen, 1H), 8.28 ( s, (CN) C = CH, 1H)

Example 3 Synthesis of Compound (C)

Synthesis of Compound (C-1) In the procedure for synthesizing Compound (A-2) described above, 4-bromo-2-fluorobenzyl bromide was replaced with 3,5-difluorobenzyl bromide (manufactured by AMAX Co.). A similar procedure was performed except that 1.26 g of product was obtained. It was confirmed by ¹ H-NMR measurement that the product was compound (C-1) (the following formula).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 1.28 (t, J = 6.9 Hz, —CH ₃ , 6H), 3.12 (d, J = 21.9 Hz, Ar—CH ₂ —P ( = O) <, 2H), 4.05 (q, J = 7.2Hz, -O-CH 2 -Me, 2H), 4.07 (q, J = 6.9Hz, -O-CH 2 -Me , 2H), 6.70 (m, benzene ring hydrogen, 1H), 6.84 (m, benzene ring hydrogen, 2H)

Synthesis of Compound (C-2) In a 500 mL four-necked flask equipped with a cooling tube, thermometer, magnetic rotor, and dropping funnel, 56 g of dibromohydantoin (manufactured by Wako Pure Chemical Industries, Ltd.) and methylene chloride (Wako Pure Chemical Industries, Ltd.) 200 mL of Kogyo Co., Ltd. was added. To the dropping funnel, 20 g of 2-methylthiophene (manufactured by Wako Pure Chemical Industries, Ltd.) and 20 mL of methylene chloride (manufactured by Wako Pure Chemical Industries, Ltd.) were slowly added. After the completion of the dropping, the mixture was further stirred for 1 hour, 1 g of azo polymerization initiator V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was heated to reflux for 3 hours. After cooling, the white substance floating was filtered off, and the filtrate was washed with water. After drying, the solvent was distilled off to obtain 21 g of product. ¹ H-NMR measurement confirmed that the product was compound (C-2) (the following formula).

¹ H-NMR (CDCl ₃ ; TMS) 4.63 (s, —CH ₂ —Br, 2H), 6.8-7.0 (m, thiophene, 2H)

Synthesis of Compound (C-3) Into a 500 mL four-necked flask equipped with a cooling tube, a thermometer, and a magnetic rotor, 25.5 g of the compound (C-2) obtained by the above procedure, triethyl phosphite (Kanto) 16.5 g of Chemical Co., Ltd.) and 200 mL of acetonitrile (manufactured by Wako Pure Chemical Industries, Ltd.) were added, and the mixture was heated to reflux for 3 hours under a nitrogen stream. After cooling, the solvent and the like were distilled off to obtain 29 g of a product. ¹ H-NMR measurement confirmed that the product was compound (C-3) (the following formula). In the following formula, “Et” represents an ethyl group.

¹ H-NMR (CDCl ₃ ; TMS) 1.13-1.37 (m, —CH ₃ , 6H), 3.27 (d, J = 20.7 Hz, Th—CH ₂ —P, 2H), 4 _{.04-4.14 (m, -CH 2 -,} 4H), 6.8-7.0 (m, thiophene, 2H)

Synthesis of Compound (C-4) In the procedure for synthesizing Compound (A-3) described above, synthesis was performed in the same manner as in Example 1 except that Compound (A-2) was changed to Compound (C-1). 4.94 g of product was obtained. It was confirmed by ¹ H-NMR measurement that the product was compound (C-4) (the following formula).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 0.97 (t, J = 7.4 Hz, —CH ₃ , 6H), 1.31-1.43 (m, —CH ₂ —, 4H), 1 _{.50-1.64 (m, -CH 2 -,} 4H), 3.31 (t, J = 7.7Hz, N-CH 2 -, 4H), 6.62 (d, J = 8.7Hz, Benzene ring hydrogen, 2H), 6.74 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.00 (d, J = 10.5 Hz, benzene ring hydrogen, 2H), 7.15 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.38 (d, J = 9.0 Hz, benzene ring hydrogen, 2H), 10.26 (s, -CHO, 1H)

Synthesis of Compound (C) In the procedure for synthesizing Compound (A-3) described above, Compound (A-1) is changed to Compound (C-4), and Compound (A-2) is changed to Compound (C-3). Except for the above, the same procedure as in Example 1 was carried out to obtain 0.54 g of a product. ¹ H-NMR measurement confirmed that the product was compound (C).
¹ H-NMR (300 MHz, DMSO-d ₆ ) 0.92 (t, J = 7.4 Hz, —CH ₃ , 6H), 1.29-1.36 (m, —CH ₂ —, 4H), 1 _{.49-1.51 (m, -CH 2 -,} 4H), 3.00-3.58 (m, N-CH 2 -, 4H), 6.64 (d, J = 9.0Hz, benzene ring Hydrogen, 2H), 6.90 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.08 (d, J = 16.5 Hz, olefin hydrogen, 1H), 7.33 (d, J = 18 .6 Hz, olefin hydrogen, 1H), 7.34 (d, J = 10.8 Hz, benzene ring hydrogen, 2H), 7.39 (d, J = 8.7 Hz, benzene ring hydrogen, 2H), 7.55 (D, J = 2.7 Hz, thiophene ring hydrogen, 1H), 7.58 (d, J = 17.1 Hz, olefin hydrogen, 1H , 7.95 (d, J = 3.9Hz, thiophene ring hydrogen, 1H), 8.47 (s, (CN) C = CH, 1H)

Example 4 Synthesis of Compound (D)

Synthesis of Compound (D-1) In the procedure for synthesizing Compound (A-1) described above, except that 3,4-difluorobenzaldehyde was changed to 3,4,5-trifluorobenzaldehyde (manufactured by Sigma-Aldrich). A similar procedure was performed to give 3.80 g of product. It was confirmed by ¹ H-NMR measurement that the product was compound (D-1) (the following formula).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 0.88 (t, J = 7.2 Hz, —CH ₃ , 6H), 1.20-1.35 (m, —CH ₂ —, 4H), 1 _{.40-1.55 (m, -CH 2 -,} 4H), 3.26 (t, J = 7.5Hz, N-CH 2 -, 4H), 7.30-7.35 (m, benzene ring Hydrogen, 2H), 9.77 (s, -C (= O) -H, 1H

Synthesis of Compound (D-2) In the procedure for synthesizing Compound (A-2) described above, except that 4-bromo-2-fluorobenzyl bromide was changed to 4-bromobenzyl bromide (manufactured by Tokyo Chemical Industry Co., Ltd.). A similar procedure was performed to give 32.18 g of product. It was confirmed by ¹ H-NMR measurement that the product was compound (D-2) (the following formula).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 1.25 (t, J = 7.1 Hz, —CH ₃ , 6H), 3.09 (d, J = 21.6 Hz, Ar—CH ₂ —, 2H ),
3.97-4.07 (m, O—CH ₂ —, 4H), 7.17 (d, benzene ring hydrogen, 2H), 7.43 (d, benzene ring hydrogen, 2H)

Synthesis of Compound (D-3) In the procedure for synthesizing Compound (A-3) described above, Compound (A-1) is converted to Compound (D-1), and Compound (A-2) is converted to Compound (D-2). The synthesis was carried out in the same manner as in Example 1 except that 4.95 g of the product was obtained. It was confirmed by ¹ H-NMR measurement that the product was compound (D-3) (the following formula).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 0.83 to 0.93 (m, —CH ₃ , 6H), 1.24 to 1.34 (m, —CH ₂ —, 4H), 1.36 _{-1.47 (m, -CH 2 -,} 4H), 3.13 (t, J = 7.4Hz, N-CH 2 -, 4H), 7.01 (d, J = 10.5Hz, benzene ring Hydrogen, 2H), 7.01 (d, J = 15.9 Hz, olefin hydrogen, 1H), 7.10 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.62 (d, J = 8 .4 Hz, benzene ring hydrogen, 2H), 7.87 (d, J = 8.4 Hz, benzene ring hydrogen, 2H), 9.99 (s, -CHO, 1H)

Synthesis of Compound (D) In the procedure for synthesizing Compound (A-3) described above, Compound (A-1) is changed to Compound (D-3), and Compound (A-2) is changed to Compound (C-3). Except for the above, the same procedure as in Example 1 was carried out to obtain 0.81 g of the product. ¹ H-NMR measurement confirmed that the product was compound (D).
¹ H-NMR (300 MHz, DMSO-d ₆ ) 0.83 (t, J = 7.4 Hz, —CH ₃ , 6H), 1.21-1.36 (m, —CH ₂ —, 8H), 3 .04-3.09 (m, N—CH ₂ —, 4H), 7.15-7.38 (m, benzene ring hydrogen, olefin hydrogen, 5H), 7.46 (d, J = 3.9 Hz, Thiophene ring hydrogen, 1H), 7.60 (d, J = 8.1 Hz, benzene ring hydrogen, 2H), 7.63 (d, J = 15.6 Hz, olefin hydrogen, 1H), 7.70 (d, J = 8.4 Hz, benzene ring hydrogen, 2H), 7.96 (d, J = 3.9 Hz, thiophene ring hydrogen, 1H), 8.47 (s, (CN) C = CH, 1H)

Synthesis of compound (E)

In the procedure for synthesizing the compound (A-3), the same procedure as in Example 1 was performed, except that the compound (A-1) was left as it was and the compound (A-2) was changed to the compound (B-2). Implementation gave 0.77 g of product. ¹ H-NMR measurement confirmed that the product was compound (E) (formula).
¹ H-NMR (300 MHz, DMSO-d ₆ ) 0.92 (t, J = 7.4 Hz, —CH ₃ , 6H), 1.27-1.39 (m, —CH ₂ —, 4H), 1 _{.47-1.52 (m, -CH 2 -,} 4H), 3.08-3.55 (m, N-CH 2 -, 4H), 6.67 (d, J = 9.0Hz, benzene ring Hydrogen, 2H), 7.01 (d, J = 15.9 Hz, olefin hydrogen, 1H), 7.48 (d, J = 15.9 Hz, olefin hydrogen, 1H), 7.49 (d, J = 9 0.0 Hz, benzene ring hydrogen, 2H), 7.78 (t, J = 7.8 Hz, benzene ring hydrogen, 1H), 8.00 (t, J = 7.8 Hz, benzene ring hydrogen, 1H), 8. 27 (s, (CN) C = CH, 1H)

Synthesis of Comparative Example 1

In the procedure of synthesizing the compound (A-3), the same procedure as in Example 1 was performed except that the compound (A-1) was left as it was and the compound (A-2) was changed to the compound (D-2). Implementation gave 0.13 g of product. ¹ H-NMR measurement confirmed that the product was the compound of Comparative Example 1 (formula above).
¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 0.96 (t, J = 7.2 Hz, —CH ₃ , 6H), 1.31-1.43 (m, —CH ₂ —, 4H), 1 _{.54-1.64 (m, -CH 2 -,} 4H), 3.32 (t, J = 7.7Hz, N-CH 2 -, 4H), 6.69 (d, J = 8.1Hz, Benzene ring hydrogen, 2H), 6.89 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.29 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.42 (d, J = 8.7 Hz, benzene ring hydrogen, 2H), 7.59 (d, J = 9.0 Hz, benzene ring hydrogen, 2H), 7.99 (d, J = 8.4 Hz, benzene ring hydrogen, 2H), 8.23 (s, (CN) C = CH, 1H)

Synthesis of Comparative Example 2

In the procedure for synthesizing the compound (A-3), synthesis was performed in the same manner as in Example 1 except that the compound (A-2) was changed to the compound (D-2) to obtain 4.95 g of a product. ¹ H-NMR measurement confirmed that the product was the compound of Comparative Example 2-1 (the following formula).

¹ H-NMR (300 MHz, CDCl ₃ ; TMS) 0.85 to 0.96 (m, —CH ₃ , 6H), 1.26 to 1.38 (m, —CH ₂ —, 4H), 1.45 _{-1.55 (m, -CH 2 -,} 4H), 2.49-2.51 (m, N-CH 2 -, 4H), 6.62 (d, J = 8.7Hz, benzene ring hydrogen, 2H), 6.88 (d, J = 16.5 Hz, olefin hydrogen, 1H), 7.13 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.38 (d, J = 8.4 Hz). , Benzene ring hydrogen, 2H), 7.46 (d, J = 8.7 Hz, benzene ring hydrogen, 2H), 7.50 (d, J = 8.7 Hz, benzene ring hydrogen, 2H)

Furthermore, in the procedure of synthesizing the compound (A-3) described above, except that the compound (A-1) was changed to the comparative example (2-1) and the compound (A-2) was changed to the compound (C-3). The same procedure as in Example 1 was performed to give 0.37 g of product. ¹ H-NMR measurement confirmed that the product was the compound of Comparative Example 2 (formula).
¹ H-NMR (300 MHz, DMSO-d ₆ ) 0.92 (t, J = 7.4 Hz, —CH ₃ , 6H), 1.26 to 1.36 (m, —CH ₂ —, 4H), 1 _{.46-1.56 (m, -CH 2 -,} 4H), 3.08-3.55 (m, N-CH 2 -, 4H), 6.63 (d, J = 9.0Hz, benzene ring Hydrogen, 2H), 6.93 (d, J = 16.2 Hz, olefin hydrogen, 1H), 7.18 (d, J = 16.5 Hz, olefin hydrogen, 1H), 7.26 (d, J = 15 .9 Hz, olefin hydrogen, 1H), 7.40 (d, J = 8.7 Hz, benzene ring hydrogen, 2H), 7.44 (d, J = 4.2 Hz, thiophene ring hydrogen, 1H), 7.53 (D, J = 8.1 Hz, benzene ring hydrogen, 2H), 7.57 (d, J = 15.0 Hz, olefin hydrogen, 1H , 7.63 (d, J = 8.4 Hz, benzene ring hydrogen, 2H), 7.94 (d, J = 4.2 Hz, thiophene ring hydrogen, 1H), 8.46 (s, (CN) C = CH, 1H)

(UV-visible absorption spectrum)
Compounds (A) to (E), which are aromatic compounds containing an amino group at the terminal of the present invention, synthesized in Examples, dyes of reference examples (Ru dyes (Ruthenium 535 bis TBA manufactured by Solaronix)), and Comparative Example 1 A solution prepared by preparing a compound of ~ 2 using acetonitrile as a solvent is put in a quartz cell (path length: 1 cm), and an ultraviolet-visible absorption spectrum is obtained with a spectrophotometer (Nippon Bunko UV-Vis near-infrared spectrophotometer V-570). Was measured. These results are shown in the table below.

  In the compound represented by the formula (1) of the present invention, a compound in which at least one of X and Y is a divalent aromatic hydrocarbon group substituted with one or more fluorine atoms has an ultraviolet-visible absorption spectrum. It has been found that this is effective. From this, it is considered that the maximum absorption wavelength and the molar extinction coefficient can be optimized by introducing an appropriate number of fluorine groups at appropriate positions as in the present invention.

(Measurement of CV)
The compounds (A) to (D), which are aromatic compounds containing amino groups at the ends of the present invention synthesized in the Examples, and the compounds of Comparative Examples 1 and 2 were each added to the supporting electrolyte (0.1 mol / L tetra ( n-butyl) ammonium tetrafluoroborate-acetonitrile solution) was added to a concentration of 0.001 mol / L to prepare a measurement solution. Glassy carbon, platinum wire, and Ag / Ag + (0.01 mol / L silver nitrate + 0.1 mol / L tetrabutylammonium perchlorate-acetonitrile solution) were used as a working electrode, a counter electrode, and a reference electrode, respectively. 10 mL was sampled as a measurement solution, and after bubbling with nitrogen for 10 minutes, the potential range from 2.00 V to -1.80 V was inserted by 0.1 V / s using an electrochemical measurement device (PGSTAT12 manufactured by ECO CHEMIE). CV measurements were made at speed. The data obtained by correcting to NHE (standard hydrogen electrode) using ferrocene as a reference substance was compared. The results are shown in the table below.

  It was found that the compound represented by the formula (1) of the present invention has a one-electron oxidation potential of the dye greatly shifted to the oxidation side as compared with the compound of the comparative example having no fluorine atom. From this result, it was suggested that the potential can be tuned to the optimum position by introducing an appropriate number of fluorine groups at an appropriate position of the dye.

(Photoelectric conversion test)
In the photoelectric conversion test, a photoelectric conversion cell was prepared using the compound which is an aromatic compound containing an amino group at the terminal of the present invention synthesized in the examples and the dye of the reference example as a sensitizing dye, and the photoelectric conversion efficiency was measured. did. In addition, the photoelectric conversion test was specifically implemented in the following procedures.

<Photoelectric conversion test: Part 1>
Photoelectric Conversion Cell FIG. 1 is a schematic diagram of a test sample of a photoelectric conversion cell used in this test.

A glass substrate 1 with a fluorine-doped tin oxide layer (transparent electrode layer) 2 having a transparent electrode thickness of 1.1 mm (manufactured by Solaronix) was used.

Titanium nanooxide HTSP (manufactured by Solaronix), which is a commercial product of titanium oxide paste, was used.

Preparation of Titanium Oxide Porous Electrode Using a 120-mesh polyester sheet (Tetron network), a titanium oxide paste is applied to the conductive surface of the transparent electrode (the surface of the transparent electrode layer 2) by a screen printing method. After drying in minutes, it was baked in an oven at 450 ° C. for 30 minutes. After firing, the temperature of the oven was dropped to 80 ° C. and the temperature was maintained.

As the sensitizing dye adsorbing sensitizing dye, the aromatic compounds (A) and (E) containing the amino group at the terminal of the present invention, the dye of Reference Example, and Comparative Example 1 having a solution concentration of 4.0 × 10 ⁻³ mol / L was dissolved in ethanol. The titanium oxide porous electrode kept at 80 ° C. after firing was placed in the dye solution (normal temperature) and immersed for 24 hours. Then, the excess titanium oxide porous layer was scraped off so as to have an effective area of 0.25 cm ² to obtain a titanium oxide porous electrode having a desired titanium oxide porous layer 4.

Electrolyte The commercially available redox electrolyte Iodolyte PN 50 (manufactured by Solaronix) was used.

  A platinum layer was laminated by sputtering on the conductive layer (transparent electrode layer 2) of the glass substrate 1 with the fluorine-doped tin oxide layer (transparent electrode layer) 2 to form a conductive counter electrode (platinum electrode layer 3). As a spacer between the titanium oxide porous electrode (titanium oxide porous layer 4) and the conductive counter electrode (platinum electrode layer 3), a resin film spacer 6 (SX-1170-60 thermoplast heat melting sealing sheet (Solaronix) Company thickness 60 μm) was used. After the production of the cell, the electrolytic solution 5 was injected and subsequently sealed to complete a test sample of the photoelectric conversion cell. Conductive wires 7 for measurement are bonded to the end of the conductive counter electrode (platinum electrode layer 3) of the test sample and the end of the conductive layer (transparent electrode layer 2) of the transparent electrode on the side where the titanium porous electrode is provided. did.

As a light source for measuring and measuring the conversion efficiency , a solar simulator (OTENTO-SUN III manufactured by Spectrometer Co., Ltd.) combined with an air mass filter was used to adjust the light amount to 100 mW / cm ² with a light meter. A potentiostat (PGSTAT 12 manufactured by AUTOLAB) was used for measurement of the IV curve characteristics. The conversion efficiency η was calculated by the following equation using Voc (open circuit voltage value), Jsc (short circuit current value), and ff (fill factor) obtained from the IV curve characteristic measurement.

The measurement results of photoelectric conversion efficiency are shown in [Table 12].

<Photoelectric conversion test: Part 2>
A photoelectric conversion cell was prepared and measured in the same manner except that the production conditions for the photoelectric conversion cell were changed as follows: titanium oxide paste, titanium oxide porous electrode production, electrolytic solution, and sensitizing dye adsorption. went.
Titanium oxide paste Titanium oxide paste manufactured by Catalyst Chemical Industry was used.
Production of porous titanium oxide electrode Using 90-mesh polyethylene sheet, titanium oxide is applied to the conductive surface of transparent electrode (surface of transparent electrode layer 2) by screen printing method (thickness of titanium oxide film is about 4-5μm). The paste was applied and baked in an oven at 450 ° C. for 30 minutes. After firing, the temperature of the oven was dropped to 80 ° C. and the temperature was maintained.
As the sensitizing dye adsorbing sensitizing dye, the aromatic compounds (B) to (D) containing amino groups at the ends synthesized by the above procedure, the dyes of Reference Examples and the compounds of Comparative Examples 1 and 2 were used, and the solution concentration Was dissolved in ethanol so as to be 3.0 × 10 ⁻⁴ mol / L. In the dye solution (40 ° C.), the titanium oxide porous electrode kept at 80 ° C. after baking was put and immersed for 6 hours. Then, the excess titanium oxide porous layer was scraped off so as to have an effective area of 0.25 cm ² to obtain a titanium oxide porous electrode having a desired titanium oxide porous layer 4.
Preparation of Electrolyte 5 Electrolyte 5 was obtained according to the following formulation.
Solvent is methoxyacetonitrile, lithium iodide is 0.1 mol / L, iodine is 0.05 mol / L, 4-tert-butylpyridine is 0.5 mol / L, 1-propyl-2,3-dimethylimidazolium iodide Was adjusted to 0.6 mol / L.
Spacer As the spacer, a resin film spacer 6 (Himiran 1702 (Mitsui-DuPont Polychemical Co., Ltd., thickness 50 μm)) was used.
As a measurement light source, a solar simulator (K-0206 manufactured by Spectrometer Co., Ltd., light source SX-150C xenon lamp 150W) is combined with an air mass filter, and adjusted to a light quantity of 100 mW / cm ^{2 with} a photometer. A light source was used. While irradiating the test sample with light, the IV curve characteristics were measured using a potentiostat (solatron 1287).
The measurement results of photoelectric conversion efficiency are shown in [Table 13].

<Photoelectric conversion test: Part 3>
Addition of deoxycholic acid Compound (A), Reference Example, and Comparative Example 1 were used under the above-mentioned photoelectric conversion cell preparation conditions in <Photoelectric Conversion Test: Part 2>, and the solution concentration was 3.0 × 10 ^{−. A} photoelectric conversion cell was prepared and measured in the same manner as in the above <Photoelectric conversion test: Part 2> except that the dye solution was dissolved in ethanol to ⁴ mol / L and further 20 mM deoxycholic acid was added. Went.
The measurement results of the photoelectric conversion efficiency in the case of the present test to which deoxycholic acid was added are shown in [Table 14].

When comparing compound (A) and compound (E) with Comparative Example 1 from [Table 12], the fluorine-containing dyes (compound (A) and compound (E)) show better results, and values close to those of the reference examples are obtained. Obtained. Moreover, when comparing the compound (B) with Comparative Example 1, the compound (C) and the compound (D) with Comparative Example 2 from [Table 13], an amino group is contained at the end of the present invention synthesized in the Examples. It was found that the aromatic compound has higher photoelectric conversion efficiency than the compound of the comparative example having no fluorine atom. Moreover, the short circuit current Jsc, the open circuit voltage Voc, and the fill factor ff, which are factors related to the photoelectric conversion efficiency, showed the same or improved values. As described above, introducing an appropriate number of fluorine groups at an appropriate position of the dye skeleton is thought to have an effect of improving factors relating to photoelectric conversion efficiency, and as a result, improving photoelectric conversion efficiency. It may be connected.
Furthermore, since high photoelectric conversion efficiency exceeding the reference example was obtained by adding an appropriate amount of deoxycholic acid as a coadsorbent from [Table 14], further photoelectric conversion efficiency could be improved by adding an appropriate amount of coadsorbent. It was suggested that improvement can be expected.

  From these results, as in the aromatic compound (1) containing an amino group at the terminal of the present invention, by substituting a fluorine atom for an aromatic hydrocarbon group, a higher photoelectric conversion efficiency than that of an unsubstituted compound can be obtained. I found out. Furthermore, it has been found that even if the compound of the present invention is used in place of the Ru dye, which is suitable as a sensitizing dye for a photoelectric conversion cell, conversion efficiency comparable to that can be obtained. Further, since the oxidation-reduction potential can be adjusted by substituting fluorine atoms, it is considered possible to obtain desired performance in accordance with the conditions of the cell actually used.

  Since the aromatic compound containing an amino group at the end of the present invention represented by the above formula (1) has a wide absorption band in the visible region, it is an increase for photoelectric conversion particularly used in a dye-sensitized photoelectric conversion battery. Suitable as a sensitizing dye. In addition to the applications listed here, the present invention can be applied to a wide range of applications such as non-linear optical materials within a range that does not impede its action.

Claims (7)

An aromatic compound containing an amino group at the end, represented by the following formula (1).

(In the above formula (1), R ¹ and R ² are each independently an alkyl group having 1 to 4 carbon atoms .
R ³ is a carboxyl group.
R ⁴ is a cyano group.
R ⁵ is a hydrogen atom.
X is a 1,4-phenylene group which may have a substituent .
Y is a 1,4-phenylene group which may have a substituent .
Z is the following structure in which a cyclic group and a conjugated chain linking group are combined . In the following structure, Y is written on the side bonded to Y.

However, the structure forms a π-conjugated system from X to the anchor group R ³ .
At least one of X and Y is a 1,4-phenylene group substituted with one or more fluorine atoms.
m is 1.
n is an integer of 0 or 1.
The double bond in the above formula (1) may give rise to any of the cis-trans isomers. ) A sensitizing dye for photoelectric conversion, comprising an aromatic compound containing an amino group at the terminal according to claim 1. A photoelectric conversion material obtained by linking the sensitizing dye for photoelectric conversion according to claim 2 and an inorganic porous material exhibiting semiconductor characteristics. The photoelectric conversion material according to claim 3, wherein a co-adsorbent is used together with the sensitizing dye for photoelectric conversion. The photoelectric conversion material according to claim 3 or 4, wherein the inorganic porous material exhibiting semiconductor characteristics is composed of an inorganic oxide. A photoelectric conversion electrode obtained by laminating the photoelectric conversion material according to claim 3 on a transparent electrode. A photoelectric conversion battery comprising the photoelectric conversion electrode according to claim 6, an electrolyte layer, and a conductive counter electrode.