JPWO2013089194A1 - Binuclear ruthenium complex dye, photoelectric conversion element having the dye, and photochemical battery - Google Patents

Abstract

The present invention relates to a binuclear ruthenium complex dye having a higher current density and higher efficiency, and a photochemical battery, and semiconductor fine particles sensitized with the dinuclear ruthenium complex dye The present invention also relates to a photochemical battery having a high conversion efficiency, and an electrolyte solution containing an ionic liquid as a main component.

Description

  The present invention relates to a novel binuclear ruthenium complex dye, a photoelectric conversion element having the dye, and a photochemical battery.

  Solar cells are highly expected as a clean renewable energy source. Solar cells made of single crystal silicon, polycrystalline silicon, or amorphous silicon, or solar cells made of compounds such as cadmium telluride and indium copper selenide Research aimed at practical application has been made. However, in order to spread it as a household power source, all of the batteries must be overcome, such as high manufacturing costs, difficulty in securing raw materials, recycling problems, and difficulty in increasing the area. Have problems. Thus, solar cells using organic materials have been proposed with the aim of increasing the area and reducing the price, but all have a conversion efficiency of about 1%, which is far from practical use.

  Under such circumstances, Gretzell et al. In 1991 disclosed a photoelectric conversion element and a solar cell using semiconductor fine particles sensitized with a dye, and materials and manufacturing techniques necessary for producing the solar cell (for example, Non-patent document 1 and Patent document 1). This battery is a wet solar cell using a porous titania thin film sensitized with a ruthenium dye as a working electrode. The advantage of this solar cell is that it can be used as an inexpensive photoelectric conversion element because it is not necessary to purify an inexpensive material with high purity, and further, the absorption of the dye used is broad, and over a wide visible light wavelength range. It can convert sunlight into electricity. However, further improvement in conversion efficiency is necessary for practical use, and development of a dye having a higher extinction coefficient and absorbing light up to a longer wavelength region is desired.

  Further, as a metal complex dye useful as a photoelectric conversion element, Patent Document 2 discloses a dipyridyl ligand-containing metal mononuclear complex, and Non-Patent Document 2 discloses a polynuclear β-diketonate complex dye. ing.

  Patent Document 3 discloses a novel multinuclear complex having a photoelectric conversion function that takes out electrons upon receiving the energy of actinic rays such as light, and has a plurality of metals and a plurality of ligands. A binuclear complex having a coordination structure in which the bridging ligand (BL) positioned has a heteroconjugated ring and a coordination structure having no heteroconjugated ring is disclosed.

  Further, in Patent Document 4 and Patent Document 5 by the present applicant, there are two metal complex dyes for obtaining a photoelectric conversion element having high photoelectric conversion efficiency, such as a binuclear ruthenium complex having a coordination structure having a heteroconjugated ring. A nuclear metal complex is disclosed.

  On the other hand, as an example of using an ionic liquid for an electrolyte composition, Patent Document 6 discloses an electrolyte composition containing an ionic liquid in which a copper complex is dissolved in an ionic liquid, and a photoelectric device using this electrolyte composition. A conversion element and a dye-sensitized solar cell are disclosed. However, this dye-sensitized solar cell does not necessarily have high conversion efficiency.

  Furthermore, in Patent Document 7 by the present applicant, in a photochemical battery comprising semiconductor fine particles sensitized by a binuclear ruthenium complex dye disclosed in Patent Document 4, and an electrolyte solution containing an ionic liquid as a main component, A combination of the binuclear ruthenium complex dye and an ionic liquid capable of expressing high conversion efficiency is disclosed.

Japanese Patent Laid-Open No. 1-220380 JP 2003-261536 A Japanese Patent Application Laid-Open No. 2004-359677 International Publication No. 2006/038587 Pamphlet International Publication No. 2011/115137 Pamphlet JP 2006-107771 A International Publication No. 2008/153184 Pamphlet

Nature, 353, 737, 1991 The latest technology of dye-sensitized solar cells (CMC Corporation, issued on May 25, 2001, page 117)

  The first object of the present invention is to provide a binuclear ruthenium complex dye having a higher current density and a more efficient photoelectric conversion element and photochemical battery. The second object of the present invention is to provide a photochemical battery having high conversion efficiency, comprising semiconductor fine particles sensitized by the binuclear ruthenium complex dye and an electrolyte solution mainly composed of an ionic liquid. .

The present invention relates to the following matters.
(1) A dinuclear ruthenium complex dye represented by the general formula (1-1) (provided that one or a plurality of carboxyl groups (—COOH) protons (H ⁺ ) may be dissociated).

（式中、Ｒ^１及びＲ^２は、それぞれ互いに独立に、置換基を有していても良いアリール基又はヘテロアリール基を示し、ｎ及びｍは０〜４の整数を示すが、ｎとｍが同時に０となることはない。なお、ｎ又はｍが２以上の場合には、複数個のＲ^１及び複数個のＲ^２は同一でも異なっていても良い。Ｘは対イオンを示し、ｑは錯体の電荷を中和するのに必要な対イオンの数を示す。
又、２つの

(In the formula, R ¹ and R ² each independently represent an aryl group or heteroaryl group which may have a substituent, and n and m represent an integer of 0 to 4, but n and m Are not simultaneously 0. When n or m is 2 or more, the plurality of R ¹ and the plurality of R ² may be the same or different, X represents a counter ion, and q Indicates the number of counter ions required to neutralize the charge of the complex.
And two

は、同一でも異なっていてもよく、それぞれ互いに独立に、二座配位可能なキレート型配位子を示す。）

May be the same or different and each represents a chelate-type ligand capable of bidentate coordination independently of each other. )

(2) A binuclear ruthenium complex dye represented by the general formula (1-2) (provided that the protons (H ⁺ ) of one or more carboxyl groups (—COOH) may be dissociated).

（式中、Ｒ^１乃至Ｒ^４は、それぞれ互いに独立に、置換基を有していても良いアリール基又はヘテロアリール基を示し、ｎ、ｍ、ｏ及びｐは０〜４の整数を示すが、ｎ、ｍ、ｏ及びｐが同時に０となることはない。なお、ｎ、ｍ、ｏ又はｐが２以上の場合には、複数個のＲ^１、複数個のＲ^２、複数個のＲ^３及び複数個のＲ^４は同一でも異なっていても良い。Ｘは対イオンを示し、ｑは錯体の電荷を中和するのに必要な対イオンの数を示す。

(In the formula, R ^{1 to} R ⁴ each independently represent an aryl group or a heteroaryl group which may have a substituent, and n, m, o and p each represent an integer of 0 to 4. , N, m, o, and p are not simultaneously 0. When n, m, o, or p is 2 or more, a plurality of R ¹ , a plurality of R ² , or a plurality of R ³ and a plurality of R ⁴ may be the same or different, X represents a counter ion, and q represents the number of counter ions necessary to neutralize the charge of the complex.

  Also two

は、同一でも異なっていてもよく、それぞれ互いに独立に、二座配位可能なキレート型配位子を示す。）

May be the same or different and each represents a chelate-type ligand capable of bidentate coordination independently of each other. )

(3) A binuclear ruthenium complex dye represented by the general formula (1-3) (provided that one or a plurality of carboxyl groups (—COOH) protons (H ⁺ ) may be dissociated).

（式中、Ｒ^６乃至Ｒ^９は、それぞれ互いに独立に、

(Wherein R ^{6 to} R ⁹ are independently of each other,

（式中、Ｒは炭素原子数１〜１２のアルキル基、Ｚは炭素原子数６〜１８のアリーレン基を示す。）
で表されるアルコキシアリーレンエテニル基を示し、ｓ、ｔ、ｕ及びｖは０〜４の整数を示すが、ｓ、ｔ、ｕ及びｖが同時に０となることはない。なお、ｓ、ｔ、ｕ又はｖが２以上の場合には、複数個のＲ^６、複数個のＲ^７、複数個のＲ^８及び複数個のＲ^９は同一でも異なっていても良い。Ｘは対イオンを示し、ｑは錯体の電荷を中和するのに必要な対イオンの数を示す。

(In the formula, R represents an alkyl group having 1 to 12 carbon atoms, and Z represents an arylene group having 6 to 18 carbon atoms.)
And s, t, u and v each represent an integer of 0 to 4, but s, t, u and v are not 0 simultaneously. When s, t, u or v is 2 or more, the plurality of R ⁶ , the plurality of R ⁷ , the plurality of R ⁸ and the plurality of R ⁹ may be the same or different. X represents a counter ion, and q represents the number of counter ions necessary to neutralize the charge of the complex.

  Also two

は、同一でも異なっていてもよく、それぞれ互いに独立に、二座配位可能なキレート型配位子を示す。）

May be the same or different and each represents a chelate-type ligand capable of bidentate coordination independently of each other. )

(4) A photoelectric conversion element comprising the binuclear ruthenium complex dye according to any one of (1) to (3) and semiconductor fine particles.
(5) The photoelectric conversion element according to (4), wherein the semiconductor fine particles are at least one kind of semiconductor fine particles selected from the group consisting of titanium oxide, zinc oxide, and tin oxide.

(6) A photochemical battery comprising the photoelectric conversion element of (4).
(7) A photochemical battery comprising the photoelectric conversion element of (4) and a counter electrode as electrodes, and an electrolyte layer therebetween.

(8) A method for producing a photoelectric conversion element, comprising a step of immersing semiconductor fine particles in a solution containing the binuclear ruthenium complex dye according to any one of (1) to (3).
(9) forming a semiconductor layer containing semiconductor fine particles on the conductive support;
Immersing this semiconductor layer in a solution containing the binuclear ruthenium complex dye of any one of (1) to (3).

(10) Semiconductor fine particles sensitized by the binuclear ruthenium complex dye of any one of (1) to (3), and the general formula (2)

（式中、Ｙ⁻は、エチルスルフェイト、２−（２−メトキシ）エトキシエチルスルフェイト、又はトリフルオロメタンスルフォネートを示す。）
で示されるイオン液体を主成分とする電解質溶液
を備える光化学電池。

(Wherein, Y ^- represents ethylsulfamoyl Fate, 2- (2-methoxy) ethoxyethyl sul fate, or trifluoromethane sulfonate.)
A photochemical battery comprising an electrolyte solution containing an ionic liquid as a main component.

  According to the present invention, a binuclear ruthenium complex dye for providing a photoelectric conversion element and a photochemical battery having a higher current density and higher efficiency can be provided. In addition, according to the present invention, a photochemical battery having high conversion efficiency, including semiconductor fine particles sensitized by the binuclear ruthenium complex dye and an electrolyte solution containing an ionic liquid as a main component can be provided. The photochemical battery is considered to be suitable for practical use because it has extremely high stability, high durability, and high photoelectric conversion efficiency.

<First Binuclear Ruthenium Complex Dye (1) and Second Binuclear Ruthenium Complex Dye (2) of the Present Invention>
The first dinuclear ruthenium complex dye (1) of the present invention is represented by the general formula (1-1). The second dinuclear ruthenium complex dye (2) of the present invention is represented by the general formula (1-2).

In the general formula (1-1), n and m each represent the number of substituents R ¹ and R ² and are integers of 0 to 4, preferably 0 to 2, more preferably 0 or 1. Particularly preferred is 1. However, n and m are not 0 at the same time. In the general formula (1-2), n, m, o and p each represent the number of substituents R ¹ , R ² , R ³ and R ⁴ , and are integers of 0 to 4, preferably 0 to 2. An integer, more preferably 0 or 1, particularly preferably n and m are 0 or 1, and o and p are 1. However, n, m, o, and p are not 0 at the same time.

In the general formula (1-1) and the general formula (1-2), the position of the substituents R ¹ and R ² is not particularly limited, but the 5-position of 2,2′-bibenzimidazolate which is a bridging ligand Or 6th-position and 5'-position or 6'-position are preferable. In the general formula (1-2) is not particularly limited position of the substituent ^{R 3} and ^{R 4,} is a ligand 4-position of the 2,2'-bipyridine, and 4 'position is preferred.

In the general formula (1-1), when n or m is 2 or more, the plurality of R ¹ and the plurality of R ² may be the same or different. In the general formula (1-2), when n, m, o or p is 2 or more, a plurality of R ¹ , a plurality of R ² , a plurality of R ³ and a plurality of R ⁴ may be the same. It may be different.

R ¹ and R ² in the general formula (1-1) and R ^{1 to} R ⁴ in the general formula (1-2) represent an aryl group or a heteroaryl group which may have a substituent. As the aryl group or heteroaryl group, for example, phenyl group, naphthyl group, anthryl group, tetracenyl group, pentacenyl group, azulenyl group, fluorenyl group, phenanthrenyl group, triphenylenyl group, pyrenyl group, chrysenyl group, picenyl group, perylenyl group, Pentaferenyl group, dibenzophenanthrenyl group, thienyl group, furyl group, pyrrolyl group, thiazolyl group, oxazolyl group, imidazolyl group, isothiazolyl group, isoxazolyl group, pyrazolyl group, thiazolyl group, triazolyl group, oxadiazolyl group, thiadiazolyl group , Benzofuryl group, benzopyrrolyl group, Zochiazoriru group, benzoxazolyl group, benzimidazolyl group, benzisothiazolyl group, benzisoxazolyl group, benzopyrazolyl group, benzothienyl group, etc. bithienyl group. R ¹ and R ² in the general formula (1-1) and R ^{1 to} R ⁴ in the general formula (1-2) are heteroaryl groups containing a sulfur atom which may have a substituent. It is preferable that it is preferably a thienyl group, a bitienyl group or a benzothienyl group, which may have a substituent.

Examples of the substituent of R ¹ and R ² in the general formula (1-1) and R ^{1 to} R ^{4 in} the general formula (1-2) include, for example, linear or branched carbon atoms of 1 to 18 carbon atoms. Alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl , Hexadecyl group, heptadecyl group, octadecyl group and the like. In addition, the number and position of these substituents are not particularly limited, and adjacent groups may be bonded to each other to form a ring.

Examples of R ¹ and R ² in the general formula (1-1) and R ^{1 to} R ⁴ in the general formula (1-2) include the following (RA) to (RC). It is done.

（式中、Ｒ_Ｓ１は、水素原子、又は直鎖又は分岐状の炭素原子数１〜１８のアルキル基を示す。）
一般式（１−１）中のＲ^１及びＲ^２、及び一般式（１−２）中のＲ^１及びＲ^２としては、Ｒ_Ｓ１が水素原子、又はメチル基である式（Ｒ−Ａ）で示される基が好ましい。一般式（１−２）中のＲ^３及びＲ^４としては、Ｒ_Ｓ１が水素原子、又は炭素原子数１〜６のアルキル基である式（Ｒ−Ｂ）で示される基、又は式（Ｒ−Ｃ）で示される基が好ましい。

(In the formula, R _S1 represents a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms.)
Formula (1-1) ^{R 1} and ^{R 2,} and general formula in (1-2) as the ^{R 1} and ^{R 2} in _the formula _{R S1} is a hydrogen atom, or a methyl group (R-A) Is preferred. As R < ³ > and R < ⁴ > in General formula (1-2), R _<S1> is a hydrogen atom or the group shown by the formula (RB) which is a C1-C6 alkyl group, or a formula (R The group represented by -C) is preferred.

  In general formula (1-1) and general formula (1-2),

は、同一でも異なっていてもよく、それぞれ互いに独立に、二座配位可能なキレート型配位子を示し、特に限定されないが、好ましくは置換基を有していても良い、ビピリジル、ピリジルキノリン、ビキノリン又はフェナントロリンである。その置換基としては、例えば、直鎖又は分岐状の炭素原子数１〜１８のアルキル基、例えば、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基、トリデシル基、テトラデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基、オクタデシル基等が挙げられる。なお、これらの置換基の数や位置は特に限定されず、隣接する基同士が互いに結合して環を形成していても良い。

May be the same or different and each represents a chelate-type ligand capable of bidentate coordination independently of each other, and is not particularly limited, but preferably has a substituent, bipyridyl, pyridylquinoline , Biquinoline or phenanthroline. As the substituent, for example, a linear or branched alkyl group having 1 to 18 carbon atoms, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, Nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group and the like can be mentioned. In addition, the number and position of these substituents are not particularly limited, and adjacent groups may be bonded to each other to form a ring.

としては、例えば、以下の（ＮＮ−Ａ）〜（ＮＮ−Ｄ）が挙げられる。

Examples thereof include the following (NN-A) to (NN-D).

（式中、Ｒ_Ｓ２は、水素原子、又は直鎖又は分岐状の炭素原子数１〜１８のアルキル基を示す。）

(In the formula, R _S2 represents a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms.)

としては、Ｒ_Ｓ２が水素原子、又は炭素原子数１〜８のアルキル基である式（ＮＮ−Ａ）で示される基、又は式（ＮＮ−Ｂ）で示される基が好ましい。

As R ₂ , a group represented by the formula (NN-A) or a group represented by the formula (NN-B), wherein R _S2 is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, is preferred.

  X represents a counter ion, for example, hexafluorophosphate ion, perchlorate ion, tetraphenylborate ion, tetrafluoroborate ion, trifluoromethanesulfonate ion, thiocyanate ion, sulfate ion, nitrate ion. , Halide ions and the like, preferably hexafluorophosphate ions, tetrafluoroborate ions, trifluoromethanesulfonate ions, nitrate ions, halide ions, more preferably hexafluorophosphate ions, tetrafluoro ions. Borate ion, nitrate ion and iodide ion. q represents the number of counter ions necessary to neutralize the charge of the complex.

Specific examples of the binuclear ruthenium complex dye (1) and the dinuclear ruthenium complex dye (2) include the following compounds (A-1) to (A-6). In formulas (A-1) to (A-6), H of —COOH may be eliminated, and —COO ⁻ may be —COOH.

  The binuclear ruthenium complex dye (1) and the binuclear ruthenium complex dye (2) of the present invention can be synthesized with reference to the method described in International Publication No. 2011/115137.

  The binuclear ruthenium complex dye (1) of the present invention can be obtained, for example, by reacting different mononuclear ruthenium complexes with each other as shown in the following formula.

（式中、

(Where

、Ｒ^１、Ｒ^２、ｎ及びｍは前記と同義である。Ｘ⁻は対イオンである１価のアニオンを示し、Ｙはハロゲン原子、Ｗは中性分子、例えば、水分子、メタノール、エタノールなどのアルコール分子、アセトンなどを示す。なお、ｃｏｄは１，５−シクロオクタジエンを示す。）
なお、対イオン（Ｘ）は１価のアニオンに限られないが、他のものも同様にして合成することができる。

, R ¹ , R ² , n and m are as defined above. X ^- is a monovalent anion being a counter ion, Y represents a halogen atom, W is a neutral molecule, for example, water molecules, methanol, alcohol molecule such as ethanol, acetone and the like. Note that cod represents 1,5-cyclooctadiene. )
The counter ion (X) is not limited to a monovalent anion, but other ions can be synthesized in the same manner.

  The binuclear ruthenium complex dye (2) of the present invention can be obtained, for example, by reacting different mononuclear ruthenium complexes with each other as shown in the following formula.

（式中、

(Where

、Ｒ^１乃至Ｒ^４、ｎ、ｍ、ｏ及びｐは前記と同義である。Ｘ⁻は対イオンである１価のアニオンを示し、Ｙはハロゲン原子を示す。なお、ｃｏｄは１，５−シクロオクタジエンを示す。）
なお、対イオン（Ｘ）は１価のアニオンに限られないが、他のものも同様にして合成することができる。

, R ^{1 to} R ⁴ , n, m, o, and p are as defined above. X ^- is a monovalent anion being a counter ion, Y represents a halogen atom. Note that cod represents 1,5-cyclooctadiene. )
The counter ion (X) is not limited to a monovalent anion, but other ions can be synthesized in the same manner.

  In addition, one mononuclear ruthenium complex is once synthesized via a mononuclear ruthenium complex precursor, and is a synthesis intermediate of the general formula (MI).

（式中、

(Where

、Ｒ^１、Ｒ^２、ｎ、ｍ、Ｘ及びｑは前記と同義である。）
で示される単核ルテニウム錯体は新規化合物である。

, R ¹ , R ² , n, m, X, and q are as defined above. )
The mononuclear ruthenium complex represented by is a novel compound.

In the binuclear ruthenium complex dyes (1) and (2) of the present invention, protons (H ⁺ ) of one or more carboxyl groups (—COOH) may be dissociated. Proton (H ⁺ ) dissociation is mainly performed by adjusting the pH of the solution.

<Third dinuclear ruthenium complex dye of the present invention (3)>
The third dinuclear ruthenium complex dye (3) of the present invention is represented by the general formula (1-3).

In the general formula (1-3), s, t, u and v each represent the number of substituents R ⁶ , R ⁷ , R ⁸ and R ⁹ , and are integers of 0 to 4, preferably 0 to 2. , More preferably 0 or 1, particularly preferably s and t are 0, and u and v are 1. However, s, t, u, and v are not 0 at the same time.

In the general formula (1-3), the positions of the substituents R ⁶ and R ⁷ are not particularly limited, but the 2 or 2 position of 2,2′-bibenzimidazolate which is a bridging ligand, and the 5 ′ position. Or 6 'position is preferable. Further, the positions of the substituents R ⁸ and R ⁹ are not particularly limited, but the 4-position and 4′-position of 2,2′-bipyridine which is a ligand are preferable.

When s, t, u or v is 2 or more, the plurality of R ⁶ , the plurality of R ⁷ , the plurality of R ⁸ and the plurality of R ⁹ may be the same or different.

R ^{6 to} R ⁹ in the general formula (1-3) are

（式中、Ｒは炭素原子数１〜１２のアルキル基、Ｚは炭素原子数６〜１８のアリーレン基を示す。）
で表される基を示す。Ｒとしては、例えば、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基などの直鎖又は分岐状の炭素原子数１〜１２のアルキル基が挙げられ、直鎖又は分岐状の炭素原子数１〜６のアルキル基が好ましい。Ｚとしては、例えば、フェニレン基、トリレン基、キシリレン基、メシチリレン基、ビフェニレン基、ナフチリレン基、アントリレン基などの炭素原子数６〜１８のアリーレン基が挙げられ、フェニレン基が好ましい。

(In the formula, R represents an alkyl group having 1 to 12 carbon atoms, and Z represents an arylene group having 6 to 18 carbon atoms.)
The group represented by these is shown. Examples of R include a linear or branched alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. A linear or branched alkyl group having 1 to 6 carbon atoms is preferred. Examples of Z include arylene groups having 6 to 18 carbon atoms such as a phenylene group, a tolylene group, a xylylene group, a mesitylylene group, a biphenylene group, a naphthylylene group, and an anthrylene group, and a phenylene group is preferable.

As R ^{6 to} R ⁹ in the general formula (1-3), a hexyloxyphenyleneethenyl group is particularly preferable.

  In general formula (1-3), two

は、同一でも異なっていてもよく、それぞれ互いに独立に、二座配位可能なキレート型配位子を示し、特に限定されないが、好ましくは置換基を有していても良い、ビピリジル、ピリジルキノリン、ビキノリン又はフェナントロリンである。その置換基としては、例えば、直鎖又は分岐状の炭素原子数１〜１８のアルキル基、例えば、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基、トリデシル基、テトラデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基、オクタデシル基等が挙げられる。なお、これらの置換基の数や位置は特に限定されず、隣接する基同士が互いに結合して環を形成していても良い。

May be the same or different and each represents a chelate-type ligand capable of bidentate coordination independently of each other, and is not particularly limited, but preferably has a substituent, bipyridyl, pyridylquinoline , Biquinoline or phenanthroline. As the substituent, for example, a linear or branched alkyl group having 1 to 18 carbon atoms, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, Nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group and the like can be mentioned. In addition, the number and position of these substituents are not particularly limited, and adjacent groups may be bonded to each other to form a ring.

としては、例えば、以下の（ＮＮ−Ａ）〜（ＮＮ−Ｄ）が挙げられる。

Examples thereof include the following (NN-A) to (NN-D).

（式中、Ｒ_Ｓ２は、水素原子、又は直鎖又は分岐状の炭素原子数１〜１８のアルキル基を示す。）

(In the formula, R _S2 represents a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms.)

としては、Ｒ_Ｓ２が水素原子、又は炭素原子数１〜１８、更に好ましくは炭素原子数１〜８のアルキル基である式（ＮＮ−Ａ）で示される基、又は式（ＮＮ−Ｂ）で示される基が好ましい。ある実施態様においては、Ｒ_Ｓ２が水素原子、又は炭素原子数１〜１８、更に好ましくは炭素原子数１〜８のアルキル基である式（ＮＮ−Ａ）で示される基であることが好ましい。

As R _S2 is a hydrogen atom, or a group represented by the formula (NN-A), which is an alkyl group having 1 to 18 carbon atoms, more preferably 1 to 8 carbon atoms, or a formula (NN-B). The groups shown are preferred. In one embodiment, R _S2 is preferably a hydrogen atom or a group represented by the formula (NN-A) which is an alkyl group having 1 to 18 carbon atoms, more preferably 1 to 8 carbon atoms.

  X represents a counter ion, for example, hexafluorophosphate ion, perchlorate ion, tetraphenylborate ion, tetrafluoroborate ion, trifluoromethanesulfonate ion, thiocyanate ion, sulfate ion, nitrate ion. , Halide ions and the like, preferably hexafluorophosphate ions, tetrafluoroborate ions, trifluoromethanesulfonate ions, nitrate ions, halide ions, more preferably hexafluorophosphate ions, tetrafluoro ions. Borate ion, nitrate ion and iodide ion. q represents the number of counter ions necessary to neutralize the charge of the complex.

Specific examples of the dinuclear ruthenium complex dye (3) include the following compounds (A-7) and (A-8). Incidentally, H in -COOH in formula (A-7) ~ (A -8) may also be eliminated, -COO ^- may be -COOH.

  The binuclear ruthenium complex dye (3) of the present invention can be synthesized with reference to the method described in International Publication No. 2011/115137.

In the dinuclear ruthenium complex dye (3) of the present invention, protons (H ⁺ ) of one or more carboxyl groups (—COOH) may be dissociated. Proton (H ⁺ ) dissociation is mainly performed by adjusting the pH of the solution.

<Photoelectric Conversion Element and Photochemical Battery of the Present Invention>
The photoelectric conversion element of the present invention includes the binuclear ruthenium complex dye and semiconductor fine particles. The binuclear ruthenium complex dye is adsorbed on the surface of the semiconductor fine particles, and the semiconductor fine particles are sensitized with the dinuclear ruthenium complex dye. In addition, you may use a binuclear ruthenium complex dye individually or in mixture of 2 or more types.

  More specifically, the photoelectric conversion element of the present invention is obtained by fixing semiconductor fine particles sensitized with the ruthenium complex dye on a conductive support (electrode).

  The conductive electrode is preferably a transparent electrode formed on a transparent substrate. Examples of the conductive agent include metals such as gold, silver, copper, platinum, and palladium, indium oxide compounds represented by indium oxide (ITO) doped with tin, and tin oxide (FTO) doped with fluorine. Examples thereof include tin oxide compounds and zinc oxide compounds.

  Examples of the semiconductor fine particles include metal oxides such as titanium oxide, zinc oxide, tin oxide, indium oxide, niobium oxide, tungsten oxide, and vanadium oxide; strontium titanate, calcium titanate, barium titanate, potassium niobate, and the like. Complex oxides of: metal sulfides such as cadmium sulfide and bismuth sulfide; metal selenides such as cadmium selenide; metal tellurides such as cadmium telluride; metal phosphides such as gallium phosphide; metals such as gallium arsenide; An arsenide etc. are mentioned. As the semiconductor fine particles, metal oxides are preferable, and for example, titanium oxide, zinc oxide, tin oxide, or a mixture containing any one or more of these is particularly preferable. In addition, you may use these semiconductor fine particles individually or in mixture of 2 or more types.

  The primary particle size of the semiconductor fine particles is not particularly limited, but is usually preferably 1 to 5000 nm, more preferably 2 to 500 nm, particularly preferably 3 to 400 nm, and particularly preferably 5 to 300 nm.

  Semiconductor fine particles sensitized with a binuclear ruthenium complex dye (semiconductor fine particles adsorbed with a dinuclear ruthenium complex dye) are brought into contact with, for example, a solution of a dinuclear ruthenium complex dye dissolved in a solvent (for example, coating) , Immersion, etc.) (see, for example, International Publication No. 2006/038587). In addition, after making it contact, it is desirable to wash | clean with various solvents and to dry.

  As a method for adsorbing the dinuclear ruthenium complex dye on the semiconductor fine particles, a semiconductor layer containing semiconductor fine particles (semiconductor fine particle film) is formed on a conductive support and then immersed in a solution containing the dinuclear ruthenium complex dye. A method is mentioned. The semiconductor layer can be formed by applying a paste of semiconductor fine particles on a conductive support and heating and baking. And after immersing in a pigment | dye solution, the electroconductive support body in which this semiconductor layer was formed is wash | cleaned and dried.

  Examples of the solvent for the dye solution include water; alcohols such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, and ethylene glycol; nitriles such as acetonitrile and propionitrile; N, N-dimethylacetamide, N, N Amides such as dimethylformamide; ureas such as N-methylpyrrolidone; sulfoxides such as dimethyl sulfoxide, and the like, preferably water, alcohols, nitriles, more preferably water, ethanol, isopropyl alcohol, t- Butanol and acetonitrile are used. In addition, these solvents may be used independently and may mix and use 2 or more types.

  The concentration of the dye in the solution is preferably 0.001 mmol / l to the saturated concentration of each complex dye of the present invention, more preferably 0.001 to 100 mmol / l, particularly preferably 0.01 to 10 mmol / l, and more. Preferably it is 0.05-1.0 mmol / l.

  Further, for example, a compound having a steroid skeleton such as cholic acid, deoxycholic acid, chenodeoxycholic acid may be added to the dye solution.

  The temperature at which the dye is adsorbed is usually 0 to 80 ° C., preferably 20 to 40 ° C. The time for adsorbing the dye (the time for immersing in the dye solution) is appropriately determined according to the conditions such as the type and concentration of the dinuclear ruthenium complex dye.

  The photochemical battery of the present invention uses the photoelectric conversion element of the present invention as described above. More specifically, the photoelectric conversion element of the present invention and a counter electrode are provided as electrodes, and an electrolyte layer is provided therebetween. Note that at least one of the electrode and the counter electrode used in the photoelectric conversion element of the present invention is a transparent electrode.

  The counter electrode functions as a positive electrode when combined with a photoelectric conversion element to form a photochemical battery. As the counter electrode, a substrate having a conductive layer can be used as in the case of the conductive electrode. However, if the metal plate itself is used, the substrate is not necessarily required. Examples of the conductive agent used for the counter electrode include conductive metal oxides such as tin oxide doped with metals such as platinum, carbon, and fluorine.

  The electrolyte (redox couple) is not particularly limited, and any known one can be used. For example, iodine and iodide (for example, metal iodide such as lithium iodide and potassium iodide, or quaternary ammonium compounds such as tetrabutylammonium iodide, tetrapropylammonium iodide, pyridinium iodide, imidazolium iodide) Iodide), bromine and bromide, chlorine and chloride, alkyl viologen and its reduced form, quinone / hydroquinone, iron (II) ion / iron (III) ion, copper (I) ion / Transition metal ion pairs such as copper (II) ion, manganese (II) ion / manganese (III) ion, cobalt ion (II) / cobalt ion (III), ferrocyan / ferricyan, cobalt tetrachloride (II) / four Cobalt (III) chloride, cobalt (II) tetrabromide / tetrabromide Baltic (III), Iridium hexachloride (II) / Iridium hexachloride (III), Ruthenium hexacyanide (II) / Ruthenium hexacyanide (III), Rhodium (II) hexachloride / Rhodium hexachloride (III), Six Rhenium chloride (III) / rhenium chloride (IV), rhenium hexachloride (IV) / rhenium hexachloride (V), osmium hexachloride (III) / osmium hexachloride (IV), osmium hexachloride (IV) / hexachloride It is formed by a combination of complex ions such as osmium (V), transition metals such as cobalt, iron, ruthenium, manganese, nickel, rhenium and biconjugated rings and derivatives thereof, terpyridine and derivatives thereof, heteroconjugated rings such as phenanthroline and derivatives thereof, and derivatives thereof. Complexes, ferrocene / ferrocenium ions, cobalt / Cobalt-ion-, ruthenocene / lutein placed um cyclopentadiene and its derivatives and metal complexes such as an ion, porphyrin compounds and the like can be used. A preferable electrolyte is an electrolyte in which iodine and lithium iodide or iodide of a quaternary ammonium compound are combined. The state of the electrolyte may be a liquid dissolved in an organic solvent, a molten salt, a so-called gel electrolyte immersed in a polymer matrix, or a solid electrolyte.

  Examples of the solvent for the electrolyte include water, alcohols, nitriles, chain ethers, cyclic ethers, chain esters, cyclic esters, chain amides, cyclic amides, chain sulfones, cyclic Sulfones, chain ureas, cyclic ureas, amines and the like are used. In addition, the said solvent is not limited to these, It can use individually or in mixture of 2 or more types.

  In one embodiment, the electrolyte of the photochemical battery is an electrolyte solution containing an ionic liquid represented by the general formula (2) as a main component. That is, the photochemical battery of the present invention comprises the semiconductor fine particles sensitized by the binuclear ruthenium complex dye (1), (2) or (3) of the present invention, and the ionic liquid represented by the general formula (2). An electrolyte solution having a main component is provided. This electrolyte solution is composed of, for example, only an ionic liquid, or contains an ionic liquid and a redox pair (a redox pair).

  Specific examples of the ionic liquid include 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium (2- (2-methoxy) ethoxyethyl sulfate), or 1-ethyl-3-methylimidazolium trifluoromethanesulfonate is mentioned. In addition, you may use these ionic liquids individually or in mixture of 2 or more types.

As a preferable aspect when the electrolyte of the photochemical battery is an electrolyte solution mainly composed of the ionic liquid represented by the general formula (2),
(1) Combination of dinuclear ruthenium complex dye (A-2) and 1-ethyl-3-methylimidazolium ethyl sulfate (2) Dinuclear ruthenium complex dye (A-2) and 1-ethyl-3-methylimidazo (3) Combination of dinuclear ruthenium complex dye (A-2) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (4) Combination of nuclear ruthenium complex dye (A-3) and 1-ethyl-3-methylimidazolium ethyl sulfate (5) Binuclear ruthenium complex dye (A-3) and 1-ethyl-3-methylimidazolium (2- (2-Methoxy) ethoxyethyl sulfate) (6) Dinuclear ruthenium complex dye (A-3) and 1-ethyl-3-methyl (7) Combination of dinuclear ruthenium complex dye (A-4) and 1-ethyl-3-methylimidazolium ethyl sulfate (8) Dinuclear ruthenium complex dye (A-4) ) And 1-ethyl-3-methylimidazolium (2- (2-methoxy) ethoxyethyl sulfate) (9) Dinuclear ruthenium complex dye (A-4) and 1-ethyl-3-methylimidazolium trifluoro Combination of Lomethanesulfonate (10) Combination of dinuclear ruthenium complex dye (A-5) and 1-ethyl-3-methylimidazolium ethylsulfate (11) Dinuclear ruthenium complex dye (A-5) and 1- Ethyl-3-methylimidazolium (2- (2-methoxy) ethoxyethyl sulfate) group Combined (12) Combination of dinuclear ruthenium complex dye (A-5) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (13) Dinuclear ruthenium complex dye (A-7) and 1-ethyl-3 -Methylimidazolium ethyl sulfate combination (14) Binuclear ruthenium complex dye (A-7) and 1-ethyl-3-methylimidazolium (2- (2-methoxy) ethoxyethyl sulfate) combination (15) A combination of a dinuclear ruthenium complex dye (A-7) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate is exemplified.

The electrolyte solution preferably contains a redox pair (a redox pair). The redox pair to be used is not particularly limited.
(1) iodine and iodide (for example, metal iodides such as lithium iodide and potassium iodide; quaternary ammonium compounds such as tetrabutylammonium iodide, tetrapropylammonium iodide, pyridinium iodide and imidazolium iodide) (Iodide) combinations,
(2) Bromine and bromides (for example, metal bromides such as lithium bromide and potassium bromide; bromides of quaternary ammonium compounds such as tetrabutylammonium bromide, tetrapropylammonium bromide, pyridinium bromide and imidazolium bromide) A combination of
(3) Combination of chlorine and chloride (for example, metal chloride such as lithium chloride and potassium chloride; chloride of quaternary ammonium compound such as tetrabutylammonium chloride, tetrapropylammonium chloride, pyridinium chloride, imidazolium chloride),
(4) Combination of alkyl viologen and its reduced form,
(5) quinone / hydroquinone, iron (II) ion / iron (III) ion, copper (I) ion / copper (II) ion, manganese (II) ion / manganese (III) ion, cobalt ion (II) / cobalt Transition metal ion pairs such as ions (III)),
(6) Ferrocyanian / ferricyan, cobalt tetrachloride (II) / cobalt tetrachloride (III), cobalt tetrabromide (II) / cobalt tetrabromide (III), iridium hexachloride (II) / iridium hexachloride ( III), ruthenium hexacyanide (II) / ruthenium hexacyanide (III), rhodium hexachloride (II) / rhodium hexachloride (III), rhenium hexachloride (III) / rhenium hexachloride (IV), rhenium hexachloride A combination of complex ions such as (IV) / rhenium hexachloride (V), osmium hexachloride (III) / osmium hexachloride (IV), osmium hexachloride (IV) / osmium hexachloride (V),
(7) Complexes formed of transition metals such as cobalt, iron, ruthenium, manganese, nickel, rhenium, and complex conjugate rings such as bipyridine and derivatives thereof, terpyridine and derivatives thereof, phenanthroline and derivatives thereof, and derivatives thereof,
(8) Complexes of cyclopentadiene such as ferrocene / ferrocenium ion, cobaltcene / cobaltcenium ion, ruthenocene / ruthenoceum ion, etc. and their derivatives and metals,
(9) Porphyrin-based compounds can be mentioned, and preferably the redox couples mentioned in (1) above are used. In addition, you may use these redox pairs individually or in mixture of 2 or more types. The amount of use of these redox pairs can be determined as appropriate.

  The photochemical cell of the present invention can be produced by a conventionally applied method.

  For example, as described above, a semiconductor fine particle paste such as an oxide is applied on a transparent electrode and heated and fired to produce a thin film of semiconductor fine particles. When the thin film of semiconductor fine particles is titania, for example, baking is performed at a temperature of 450 to 500 ° C. and a heating time of 30 minutes, or at a temperature of 400 to 550 ° C. for 0.5 to 1 hour. The transparent electrode with the thin film is immersed in a dye solution (a solution containing the dinuclear ruthenium complex dye of the present invention), and the dye is supported to produce a photoelectric conversion element. Furthermore, the photochemical cell of the present invention can be manufactured by combining this photoelectric conversion element and a transparent electrode on which platinum or carbon is deposited as a counter electrode, and putting an electrolyte solution therebetween.

  The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto.

Abbreviations in the examples are as follows.
2,2′-bipyridine phen; 1,10-phenanthroline cod; 1,5-cyclooctadiene dtBubpy; 4,4′-di-tert-butyl-2,2′-bipyridine H ₂ dcbpy; '-Bipyridine-4,4'-dicarboxylic acid Etcbpy; 2,2'-bipyridine-4,4'-dicarboxylic acid diethyl ester BiBzImH ₂ ; 2,2'-bisbenzimidazole MTBiBzImH ₂ ; 5,5'-bis ( 5-methylthiophen-2-yl) -2,2′-bisbenzimidazole BisBiTbpy; 4,4′-di ([2,2′-bithiophen] -5-yl) -2,2′-bipyridine BisBzTbpy; 4 , 4′-bis (benzo (b) thiophen) -2-yl) -2,2′-bipyridine

  In addition, the photoelectric conversion efficiency of the photochemical cell was measured by irradiating simulated sunlight from a solar simulator (manufactured by Eihiro Seiki Co., Ltd.).

Example A1 (Synthesis of dinuclear ruthenium complex dye (A1a))
Under a nitrogen atmosphere, commercially available H ₂ dcbpy (5.44 g, 22.3 mmol), concentrated sulfuric acid (10 mL), and ethanol 130 mL were added to a 500 mL three-necked flask, and the mixture was refluxed overnight to be reacted. The reaction solution was allowed to cool, neutralized, and filtered. The residue was washed with hot water and recrystallized with ethanol / water (95: 5). After filtering the crystals and vacuum drying, 4.92 g of Etcbpy was obtained.

Next, commercially available ruthenium chloride (1.18 g, 4.51 mmol), Etcbpy (2.64 g, 8.79 mmol) and 500 mL of ethanol were added to a 1000 mL three-necked flask under an argon atmosphere, and the mixture was refluxed for 7 hours to be reacted. . The reaction solution was allowed to cool, filtered, and dried in vacuo to obtain 1.64 g of [Ru (Etcbpy) ₂ Cl ₂ ]. Further, the filtrate was concentrated under reduced pressure, 300 mL of 2 mol / L hydrochloric acid was added to the concentrate, and the mixture was stirred for 5 minutes at room temperature and filtered. The residue was washed with water, recrystallized with ethanol / dichloromethane (10: 3), filtered, and vacuum dried to obtain 1.34 g of [Ru (Etcbpy) ₂ Cl ₂ ], a total of 2.98 g.

Subsequently, [Ru (Etcbpy) ₂ Cl ₂ ] (1.37 g, 1.77 mmol), silver trifluoromethanesulfonate (1.09 g, 4.25 mmol) and 140 mL of dichloromethane were added to a 200 mL three-necked flask. Stir for hours. The reaction solution was allowed to stand overnight and then filtered. The filtrate was concentrated under reduced pressure, diethyl ether was added to the concentrate, and the mixture was stirred for 5 minutes at room temperature and then filtered. The residue was washed with diethyl ether and dried under vacuum to obtain 1.62 g of [Ru (Etcbpy) ₂ (H ₂ O) ₂ ] (OTf) ₂ .

Under an argon atmosphere, [Ru (dtBubpy) ₂ Cl ₂ ] (0.142 g, 0.200 mmol), MTBiBzImH ₂ (0.102 g, 0.240 mmol), and 8 mL of ethylene glycol were added to deaerate. Thereafter, the mixture was refluxed for 14 minutes with stirring under microwave irradiation of 2.45 GHz. After allowing the reaction solution to cool, 3 mL of ethanol and 4.5 mL of water were added, and the mixture was stirred at room temperature for 30 minutes. The stirred solution was suction filtered, ammonium hexafluorophosphate (0.131 g, 0.804 mmol) was added to the filtrate, and the mixture was stirred at room temperature for 1 hour. The precipitate in the stirring liquid was filtered to obtain 0.209 g of [Ru (dtBubpy) ₂ (MTBiBzImH ₂ )] (PF ₆ ) ₂ .

[Ru (dtBubpy) ₂ (MTBiBzImH ₂ )] (PF ₆ ) ₂ (0.200 g, 0.147 mmol), 0.051 mL of 28% sodium methoxide methanol solution, N, N- 24 mL of dimethylformamide was added and stirred at room temperature for 5 minutes. Thereafter, [Ru (Etcbpy) ₂ (H ₂ O) ₂ ] (OTf) ₂ (0.200 g, 0.197 mmol) and 24 mL of N, N-dimethylformamide were added to the reaction solution for deaeration. Thereafter, the mixture was refluxed for 40 minutes with stirring under microwave irradiation of 2.45 GHz. The reaction solution was allowed to cool, then concentrated under reduced pressure, 48 mL of a 0.2 mol / L aqueous sodium hydroxide solution was added, and the mixture was heated with stirring at 100 ° C. for 3.5 hours. The reaction solution was allowed to cool and then filtered. To the residue, 30 mL of methanol and 110 mL of water were added, and 0.7 mL of a 0.79 mol / L hydroiodic acid aqueous solution was added to form a precipitate. The precipitate was filtered, purified by ODS column chromatography, concentrated under reduced pressure, and dried under vacuum. After adding 70 mL of water and 0.8 mL of 0.2 mol / L aqueous sodium hydroxide solution to the purified product, 0.79 mol / L An aqueous hydroiodic acid solution (0.4 mL) was added to form a precipitate. The precipitate was filtered and washed with a 0.79 mmol / L hydroiodic acid aqueous solution to obtain 0.097 g of a dinuclear ruthenium complex dye (A1a).

  A structure in which protons which are representative structures of the dinuclear ruthenium complex dye are not dissociated is shown in Formula (A1a). Some of the complex dyes have one or more protons of the carboxyl group dissociated. There are also isomers depending on the position of the 5-methylthiophen-2-yl group.

Reference Example A1
A dinuclear ruthenium complex dye (A3) was synthesized by a known method.

Example A3-1 (Preparation of porous titania electrode)
The catalyst chemical titania paste PST-18NR was applied to the transparent layer, and PST-400C was applied to the diffusion layer, and applied onto a transparent conductive glass electrode manufactured by Asahi Glass Co., Ltd. using a screen printer. The obtained film was aged for 5 minutes in an atmosphere of 25 ° C. and a relative humidity of 60%, and the aged film was baked at 450 ° C. for 30 minutes. The same operation was repeated on the cooled membrane until a predetermined thickness was obtained, thereby producing a 16 mm ² porous titania electrode.

Example A3-2 (Preparation of porous titania electrode adsorbed with dye)
A porous titania electrode was immersed in a 0.2 mmol / l dye solution (solvent: 2-propanol) of a dinuclear ruthenium complex dye at 30 ° C. for a predetermined time and dried to obtain a dye-adsorbing porous titania electrode.

Example A3-3 (Production of photochemical battery)
The dye adsorbing porous titania electrode obtained as described above and a platinum plate (counter electrode) were superposed. Next, an electrolyte solution (gamma-butyrolactone and 1-methyl-3-propylimidazolium iodide, iodine, and tetrabutylammonium tetracyanoborate were added at 0.6 mol / l, 0.05 mol / l, and 0.5 mol / l, respectively. A photochemical battery was prepared by soaking the gap between the two electrodes using a capillary phenomenon.

Example A3-4 (Evaluation of Photochemical Battery)
The current density included in the photoelectric conversion efficiency of the obtained photochemical battery was measured by irradiating 100 mW / cm ² of artificial sunlight using a solar simulator manufactured by Eihiro Seiki Co., Ltd.

As a result, current density (mA / cm ²⁾ is, 12.21mA / cm ² in binuclear ruthenium complex dye (A1a), in binuclear ruthenium complex dye of Example A1 (A3) 10.97mA / cm ² met It was. That is, a dye in which a heteroaryl group (here, a 5-methylthiophen-2-yl group at the 6-position and 6'-position) is introduced into 2,2′-bisbenzimidazole, which is a bridging ligand, has a higher current. The density is shown. Thus, it has been found that the dinuclear ruthenium complex dye of the present invention can be a dye for producing a high-performance photochemical battery.

Example B1a (Synthesis of dinuclear ruthenium complex dye (B1a))
(Synthesis of 4,4′-di ([2,2′-bithiophene] -5-yl) -2,2′-bipyridine (BisBiTbpy))
5- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -2,2′-bithiophene (3.917 g, 13.40 mmol) in a 100 mL three-necked flask under an argon atmosphere 4,4′-dibromo-2,2′-bipyridine (2.002 g, 6.376 mmol), potassium carbonate (7.023 g, 50.81 mmol), and N, N-dimethylformamide 50 mL were added for deaeration. Thereafter, tetrakis (triphenylphosphine) palladium (0) (0.736 g, 0.637 mmol) was added and deaerated. Then, it was made to react at 100 degreeC for 6.5 hours. After allowing to cool, the reaction mixture was filtered, and the residue was washed with N, N-dimethylformamide, water and methanol and dried in vacuo to give 2.854 g of BisBiTbpy.

(Synthesis of 5,5′-bis (5-methylthiophen-2-yl) -2,2′-bisbenzimidazole (MTBiBzImH ₂ ))
In a 500 mL three-necked flask under an argon atmosphere, 4-bromo-1,2-diaminobenzene (1.821 g, 9.733 mmol), 5-methylthiopheneboronic acid (1.605 g, 11.30 mmol), potassium carbonate (19.50 g) , 141.1 mmol), and 250 mL of toluene was added and degassed. Then, tetrakis (triphenylphosphine) palladium (0) (0.285 g, 0.247 mmol) was added and deaerated. Then, it was made to react at 85 degreeC for 25.5 hours. After allowing to cool, the reaction solution was filtered, and the filtrate was concentrated under reduced pressure and dried in vacuo. A dried product and 135 mL of ethyl acetate were added to a 300 mL eggplant flask, and a 5 mol / L hydrochloric acid aqueous solution was added dropwise with stirring to produce a precipitate. The precipitate was collected by filtration, washed with ethyl acetate, and dried in vacuo. The dried product was subjected to solvent fractionation with 50 mL of ethyl acetate and 20 mL of 2 mol / L aqueous sodium hydroxide solution, and the ethyl acetate layer was concentrated under reduced pressure and dried under vacuum to give 4- (5-methylthiophen-2-yl) -1,2- 1.060 g of diaminobenzene was obtained.

Under an argon atmosphere, a 100 mL two-necked flask was charged with 4- (5-methylthiophen-2-yl) -1,2-diaminobenzene (0.535 g, 2.618 mmol), methyl 2,2,2-trichloroacetimate ( 0.245 g, 1.387 mmol) and 25 mL of ethanol were added for deaeration. Thereafter, the mixture was refluxed for 28 hours. After allowing to cool, the reaction mixture was filtered, and the residue was washed with ethanol and dried in vacuo to give 0.262 g of MTBiBzImH ₂ .

(Synthesis of dinuclear ruthenium complex dye (B1a))
Under an argon atmosphere, dichloro-p-cymene ruthenium dimer (0.100 g, 0.163 mmol), BisBiTbpy (0.158 g, 0.326 mmol) and 50 mL of N, N-dimethylformamide were added and degassed in a 100 mL three-necked flask. . Then, it was made to react at 60 degreeC for 4 hours.

The reaction solution was allowed to cool, H ₂ dcbpy (0.08 g, 0.328 mmol) was added, the mixture was deaerated again, and reacted at 140 ° C. for 9 hours. After allowing the reaction liquid to cool, 0.660 mL of 1 mol / L sodium hydroxide and [Ru (phen) ₂ (MTBiBzIm)] (0.262 g, 0.295 mmol) were added and reacted at 170 ° C. for 4 hours.

  The resulting reaction solution was filtered, and the filtrate was concentrated under reduced pressure and dried under vacuum, purified by ODS column chromatography, concentrated under reduced pressure, and dried under vacuum. The purified product was dissolved in 30 mL of methanol and 0.03 mL of 0.5 mol / L hexafluorophosphoric acid aqueous solution, and a precipitate was produced in 30 mL of pH 2 hexafluorophosphoric acid aqueous solution. The precipitate was filtered, and the residue was washed with a pH 2 hexafluorophosphoric acid aqueous solution and then vacuum-dried to obtain 0.059 g of a binuclear ruthenium complex dye (B1a).

  A structure in which protons that are representative structures of the dinuclear ruthenium complex dye are not dissociated is shown in Formula (B1a). Some of the complex dyes have one or more protons of the carboxyl group dissociated. There are also isomers depending on the position of the 5-methylthiophen-2-yl group.

Example B1b (Synthesis of dinuclear ruthenium complex dye (B1b))
(Synthesis of [Ru (dtBubpy) ₂ Cl ₂ ])
1000mL of a three-necked flask _{[Ru (cod) Cl 2]} n (2.999g, 10.70mmol), dtBubpy (5.755g, 21.44mmol) and N, was degassed by the addition of N- dimethylformamide 300 mL. Thereafter, the mixture was refluxed for 34 minutes with stirring under microwave irradiation at 2.45 GHz. The reaction solution was allowed to cool and then filtered. The filtrate was concentrated under reduced pressure and dried under vacuum, and then 20 mL of N, N-dimethylformamide and 250 mL of diethyl ether were added to the dried product, followed by stirring at room temperature for 30 minutes. The stirred suspension was filtered, and the residue was washed with diethyl ether and water and dried in vacuo to give 7.027 g of [Ru (dtBubpy) ₂ Cl ₂ ].

(Synthesis of [Ru (dtBubpy) ₂ (MTBiBzImH ₂ )])
Under an argon atmosphere, [Ru (dtBubpy) ₂ Cl ₂ ] (0.351 g, 0.495 mmol), MTBiBzImH ₂ (0.254 g, 0.595 mmol) and 21 mL of ethylene glycol were deaerated in a 100 mL three-necked flask. Thereafter, the mixture was refluxed for 14 minutes with stirring under microwave irradiation of 2.45 GHz. After allowing the reaction solution to cool, 10 mL of ethanol and 12 mL of water were added and filtered. 1.5 mL of 1.3 mol / L ammonium hexafluorophosphate aqueous solution was added to the filtrate to produce a precipitate. The precipitate was filtered, and the filtrate was vacuum-dried to obtain 0.590 g of [Ru (dtBubpy) ₂ (MTBiBzImH ₂ )] (PF ₆ ) ₂ .

(Synthesis of dinuclear ruthenium complex dye (B1b))
Under an argon atmosphere, dichloro-p-cymene ruthenium dimer (0.124 g, 0.203 mmol), BisBiTbpy (0.197 g, 0.406 mmol), and 62 mL of N, N-dimethylformamide were degassed in a 300 mL three-necked flask. . Then, it was made to react at 60 degreeC for 4.5 hours. The reaction solution was allowed to cool, H ₂ dcbpy (0.101 g, 0.411 mmol) was added, the mixture was degassed again, and reacted at 140 ° C. for 9 hours. After allowing the reaction liquid to cool, 1.420 mL of 1 mol / L sodium hydroxide and [Ru (dtBubpy) ₂ (MTBiBzImH ₂ )] (PF ₆ ) ₂ (0.375 g, 0.277 mmol) were added, and 11 at 170 ° C. Reacted for hours. The resulting reaction solution was filtered, the filtrate was concentrated under reduced pressure, purified by ODS column chromatography, concentrated under reduced pressure, dried in vacuo, dissolved in 100 mL of methanol, 1 mL of 0.5 mol / L hexafluorophosphate aqueous solution, pH 2 A precipitate was formed with 100 mL of an aqueous hexafluorophosphoric acid solution. The precipitate was filtered, and the residue was washed with a pH 2 hexafluorophosphoric acid aqueous solution and then vacuum-dried to obtain 0.312 g of a binuclear ruthenium complex dye (B1b).

  A structure in which protons which are representative structures of the dinuclear ruthenium complex dye are not dissociated is shown in Formula (B1b). Some of the complex dyes have one or more protons of the carboxyl group dissociated. There are also isomers depending on the position of the 5-methylthiophen-2-yl group.

Example B1c (Synthesis of dinuclear ruthenium complex dye (B1c))
(Synthesis of BisBzTbpy)
Benzo [b] thiophen-2-ylboronic acid (2.417 g, 13.58 mmol), 4,4′-dibromo-2,2′-bipyridine (2.004 g, 6.383 mmol) in a 200 mL three-necked flask under an argon atmosphere , Potassium carbonate (7.005 g, 50.68 mmol) and 50 mL of N, N-dimethylformamide were added for deaeration. Then, tetrakis (triphenylphosphine) palladium (0) (0.725 g, 0.627 mmol) was added and deaerated. Then, it was made to react at 100 degreeC for 23.5 hours. After allowing to cool, the reaction mixture was filtered, and the residue was washed with N, N-dimethylformamide, water and methanol and dried in vacuo to give BisBzTbpy 1.622 g.

(Synthesis of dinuclear ruthenium complex dye (B1c))
Under an argon atmosphere, a 300 mL three-necked flask was degassed by adding dichloro-p-cymene ruthenium dimer (0.124 g, 0.203 mmol), BisBzTbpy (0.707 g, 0.406 mmol) and N, N-dimethylformamide 60 mL. . Then, it was made to react at 100 degreeC for 3 hours.

The reaction solution was allowed to cool, H ₂ dcbpy (0.100 g, 0.412 mmol) was added, the mixture was degassed again, and reacted at 140 ° C. for 9 hours. After allowing the reaction liquid to cool, 1.42 mL of 1 mol / L sodium hydroxide and [Ru (phen) ₂ (BiBzIm)] (0.192 g, 0.277 mmol) were added and reacted at 170 ° C. for 4.5 hours. .

  The resulting reaction solution was filtered, and the residue was washed with N, N-dimethylformamide and then vacuum dried. The dried sample is purified by ODS column chromatography, concentrated under reduced pressure, vacuum dried, dissolved in 50 mL methanol, 0.5 mL 0.5 mol / L hexafluorophosphoric acid aqueous solution, and pH 2 hexafluorophosphoric acid aqueous solution 50 mL. It was precipitated with. The precipitate was filtered, and the residue was washed with a pH 2 hexafluorophosphoric acid aqueous solution and then vacuum-dried to obtain 0.055 g of a binuclear ruthenium complex dye (B1c).

  A structure in which protons which are representative structures of the dinuclear ruthenium complex dye are not dissociated is shown in Formula (B1c). Some of the complex dyes have one or more protons of the carboxyl group dissociated.

Example B1d (Synthesis of dinuclear ruthenium complex dye (B1d))
Under an argon atmosphere, dichloro-p-cymene ruthenium dimer (0.100 g, 0.163 mmol), BisBiTbpy (0.158 g, 0.326 mmol) and 50 mL of N, N-dimethylformamide were added and degassed in a 100 mL three-necked flask. . Then, it was made to react at 60 degreeC for 4 hours.

The reaction solution was allowed to cool, H ₂ dcbpy (0.080 g, 0.328 mmol) was added, the mixture was deaerated again, and reacted at 140 ° C. for 9 hours. After allowing the reaction solution to cool, 0.660 mL of 1 mol / L sodium hydroxide and [Ru (phen) ₂ (BiBzIm)] (0.206 g, 0.297 mmol) were added and reacted at 170 ° C. for 4 hours.

  The resulting reaction solution was filtered, and the residue was washed with N, N-dimethylformamide and then vacuum dried. The dried sample is purified by ODS column chromatography, concentrated under reduced pressure, vacuum dried, dissolved in 70 mL methanol, 0.7 mL 0.5 mol / L hexafluorophosphoric acid aqueous solution, and pH 2 hexafluorophosphoric acid aqueous solution 100 mL. It was precipitated with. The precipitate was filtered, and the filtrate was washed with a hexafluorophosphoric acid aqueous solution having a pH of 2, and then vacuum-dried to obtain 0.049 g of a binuclear ruthenium complex dye (B1d).

  A structure in which protons that are representative structures of the dinuclear ruthenium complex dye are not dissociated is shown in Formula (B1d). Some of the complex dyes have one or more protons of the carboxyl group dissociated.

Reference Example B1 (Synthesis of dinuclear ruthenium complex dye (B3))
A dinuclear ruthenium complex dye (B3) was synthesized by a known method.

Example B3-1 (Preparation of porous titania electrode)
The catalyst chemical titania paste PST-18NR was applied to the transparent layer, and PST-400C was applied to the diffusion layer, and applied onto a transparent conductive glass electrode manufactured by Asahi Glass Co., Ltd. using a screen printer. The obtained film was aged for 5 minutes in an atmosphere of 25 ° C. and a relative humidity of 60%, and the aged film was baked at 450 ° C. for 30 minutes. The same operation was repeated on the cooled membrane until a predetermined thickness was obtained, thereby producing a 16 mm ² porous titania electrode.

Example B3-2 (Preparation of porous titania electrode adsorbed with dye)
A porous titania electrode was immersed in a 0.2 mmol / l dye solution (solvent: 2-propanol) of a dinuclear ruthenium complex dye at 30 ° C. for a predetermined time and dried to obtain a dye-adsorbing porous titania electrode.

Example B3-3 (Production of Photochemical Battery)
The dye adsorbing porous titania electrode obtained as described above and a platinum plate (counter electrode) were superposed. Next, an electrolyte solution (gamma-butyrolactone and 1-methyl-3-propylimidazolium iodide, iodine, and tetrabutylammonium tetracyanoborate were added at 0.6 mol / l, 0.05 mol / l, and 0.5 mol / l, respectively. A photochemical battery was prepared by soaking the gap between the two electrodes using a capillary phenomenon.

Example B3-4 (Evaluation of Photochemical Battery)
The current density included in the photoelectric conversion efficiency of the obtained photochemical battery was measured by irradiating 100 mW / cm ² of artificial sunlight using a solar simulator manufactured by Eihiro Seiki Co., Ltd.

As a result, the current density (mA / cm ² ) was as follows.
Dinuclear ruthenium complex dye (B1a); 11.78 mA / cm ²
Dinuclear ruthenium complex dye (B1b); 13.01 mA / cm ²
Dinuclear ruthenium complex dye (B1c); 13.82 mA / cm ²
Dinuclear ruthenium complex dye (B1d); 13.91 mA / cm ²
Dinuclear ruthenium complex dye (B3); 11.27 mA / cm ²

As a result, the binuclear ruthenium complex dyes (B1a) to (B1d) of the present invention have a current density of 0.5 to 2.6 mA / cm as compared with the existing binuclear ruthenium complex dye (B3) of Reference Example B1. It was about ² higher. From this, it was found that the dinuclear ruthenium complex dye of the present invention can be a dye for producing a photochemical battery with higher performance.

Synthesis Example C1 (Synthesis of dinuclear ruthenium complex dye (A-2))
A binuclear ruthenium complex dye (A-2) [binuclear ruthenium complex dye (B1d)] was synthesized in the same manner as in Example B1d.

Synthesis Example C2 (Synthesis of dinuclear ruthenium complex dye (A-3))
The dinuclear ruthenium complex dye (A-3) [binuclear ruthenium complex dye (B1b)] was synthesized in the same manner as in Example B1b.

Synthesis Example C3 (Synthesis of dinuclear ruthenium complex dye (A-4))
A dinuclear ruthenium complex dye (A-4) [binuclear ruthenium complex dye (B1a)] was synthesized in the same manner as in Example B1a.

Synthesis Example C4 (Synthesis of dinuclear ruthenium complex dye (A-5))
In the same manner as in Example B1c, a binuclear ruthenium complex dye (A-5) [binuclear ruthenium complex dye (B1c)] was synthesized.

Example C1 (Evaluation of photoelectric conversion efficiency)
(Preparation of porous titania electrode)
Using titania paste PST-18NR (manufactured by JGC Catalysts & Chemicals Co., Ltd.) for the transparent layer and PST-400C (manufactured by JGC Catalysts & Chemicals Co., Ltd.) for the diffusion layer, on the transparent conductive glass electrode (manufactured by Asahi Glass Co., Ltd.) It was applied using a screen printer. The obtained film was aged for 5 minutes in an atmosphere of 25 ° C. and a relative humidity of 60%, and the aged film was baked at 440 to 460 ° C. for 30 minutes. By repeating this operation, a 16 mm ² porous titania electrode was produced.

(Preparation of porous titania electrode adsorbed with dye)
A dinuclear ruthenium complex dye (A-2) was added to a mixed solvent of t-butanol / acetonitrile (= 1: 1 (volume ratio)) to prepare a saturated dye solution of the dinuclear ruthenium complex dye. Subsequently, the porous titania electrode was immersed in this saturated dye solution for 5 hours in a thermostatic chamber with an internal temperature of 30 ° C. to produce a porous titania electrode adsorbing the dye.

(Production of photochemical battery)
The obtained dye-adsorbing porous titania electrode and a platinum plate (counter electrode) were superposed. Further, from 1-ethyl-3-methylimidazolium ethyl sulfate (ionic liquid), 1-ethyl-3-methylimidazolium iodide and iodine (redox couple), the concentration of iodide ion is 1.0 mol / 1 electrolyte solution was prepared. A photochemical battery was produced by impregnating the obtained electrolyte solution into the gap between both electrodes using capillary action. The conversion efficiency of the produced photochemical battery was 3.7%.

Examples C2-C12, Reference Examples C1-C4, Comparative Examples C1-C12 (Evaluation of Photoelectric Conversion Efficiency)
A photochemical battery was prepared in the same manner as in Example C1 except that the dinuclear ruthenium complex dye and the ionic liquid were changed as shown in Table 1 in Example C1, and the conversion efficiency was measured. The dinuclear ruthenium complexes (B-1), (B-2) and (B-3) in Comparative Examples C1 to C12 are the following compounds. The results are also shown in Table 1.

  Table 2 shows the conversion efficiency of each combination when the conversion efficiency of each binuclear ruthenium complex dye and 1-ethyl-3-methylimidazolium bistrifluoromethylsulfonylimide is 100.

  From the above results, it can be seen that a photochemical cell including semiconductor fine particles sensitized by the specific dinuclear ruthenium complex dye of the present invention and an electrolyte solution containing a specific ionic liquid as a main component exhibits high conversion efficiency.

Synthesis Example D1 (Synthesis of dinuclear ruthenium complex dye (A-7))
A dinuclear ruthenium complex dye (A-7) was synthesized in the same manner as in Example B4 of International Publication No. 2011/115137.

Example D1 (Evaluation of photoelectric conversion efficiency)
(Preparation of porous titania electrode)
Using titania paste PST-18NR (manufactured by JGC Catalysts & Chemicals Co., Ltd.) for the transparent layer and PST-400C (manufactured by JGC Catalysts & Chemicals Co., Ltd.) for the diffusion layer, on the transparent conductive glass electrode (manufactured by Asahi Glass Co., Ltd.) It was applied using a screen printer. The obtained film was aged for 5 minutes in an atmosphere of 25 ° C. and a relative humidity of 60%, and the aged film was baked at 440 to 460 ° C. for 30 minutes. By repeating this operation, a 16 mm ² porous titania electrode was produced.

(Preparation of porous titania electrode adsorbed with dye)
A dinuclear ruthenium complex dye (A-7) was added to a mixed solvent of t-butanol / acetonitrile (= 1: 1 (volume ratio)) to prepare a saturated dye solution of the dinuclear ruthenium complex dye. Subsequently, the porous titania electrode was immersed in this saturated dye solution for 5 hours in a thermostatic chamber with an internal temperature of 30 ° C. to produce a porous titania electrode adsorbing the dye.

(Production of photochemical battery)
The obtained dye-adsorbing porous titania electrode and a platinum plate (counter electrode) were superposed. Further, from 1-ethyl-3-methylimidazolium ethyl sulfate (ionic liquid), 1-ethyl-3-methylimidazolium iodide and iodine (redox couple), the concentration of iodide ion is 1.0 mol / 1 electrolyte solution was prepared. A photochemical battery was produced by impregnating the obtained electrolyte solution into the gap between both electrodes using capillary action. The conversion efficiency of the produced photochemical battery was 4.0%.

Examples D2 to D3, Reference Example D1, Comparative Examples D1 to D12 (Evaluation of Photoelectric Conversion Efficiency)
A photochemical battery was prepared in the same manner as in Example D1 except that the dinuclear ruthenium complex dye and the ionic liquid were changed as shown in Table 3 in Example D1, and the conversion efficiency was measured. The dinuclear ruthenium complexes (B-1), (B-2) and (B-3) in Comparative Examples D1 to D12 are the following compounds. The results are also shown in Table 3.

  Table 4 shows the conversion efficiency of each combination when the conversion efficiency of each binuclear ruthenium complex dye and 1-ethyl-3-methylimidazolium bistrifluoromethylsulfonylimide is 100.

  From the above results, it can be seen that a photochemical cell including semiconductor fine particles sensitized by the specific dinuclear ruthenium complex dye of the present invention and an electrolyte solution containing a specific ionic liquid as a main component exhibits high conversion efficiency.

  According to the present invention, a binuclear ruthenium complex dye for providing a photoelectric conversion element and a photochemical battery having a higher current density and higher efficiency can be provided.

  In addition, according to the present invention, a photochemical battery having high conversion efficiency, comprising semiconductor fine particles sensitized by the binuclear ruthenium complex dye and an electrolyte solution containing ionic liquid as a main component can be provided. The photochemical battery is considered to be suitable for practical use because it has extremely high stability, high durability, and high photoelectric conversion efficiency.

Claims (16)

A dinuclear ruthenium complex dye represented by the general formula (1-1) (provided that one or a plurality of carboxyl groups (—COOH) protons (H ⁺ ) may be dissociated).

(In the formula, R ¹ and R ² each independently represent an aryl group or heteroaryl group which may have a substituent, and n and m represent an integer of 0 to 4, but n and m Are not simultaneously 0. When n or m is 2 or more, the plurality of R ¹ and the plurality of R ² may be the same or different, X represents a counter ion, and q Indicates the number of counter ions required to neutralize the charge of the complex.
And two

May be the same or different and each represents a chelate-type ligand capable of bidentate coordination independently of each other. ) A binuclear ruthenium complex dye represented by the general formula (1-2) (provided that the proton (H ⁺ ) of one or more carboxyl groups (—COOH) may be dissociated).

(In the formula, R ^{1 to} R ⁴ each independently represent an aryl group or a heteroaryl group which may have a substituent, and n, m, o and p each represent an integer of 0 to 4. , N, m, o, and p are not simultaneously 0. When n, m, o, or p is 2 or more, a plurality of R ¹ , a plurality of R ² , or a plurality of R ³ and a plurality of R ⁴ may be the same or different, X represents a counter ion, and q represents the number of counter ions necessary to neutralize the charge of the complex.
And two

May be the same or different and each represents a chelate-type ligand capable of bidentate coordination independently of each other. ) R ¹ and R ² in the general formula (1-1) or R ^{1 to} R ⁴ in the general formula (1-2) are heteroaryl groups containing a sulfur atom that may have a substituent. The binuclear ruthenium complex dye according to any one of claims 1 to 2. R ¹ and R ² in the general formula (1-1), or R ^{1 to} R ⁴ in the general formula (1-2) may have a substituent, a thienyl group, a bithienyl group, or a benzothienyl. The dinuclear ruthenium complex dye according to claim 3, which is a group.

Is bipyridyl, pyridylquinoline, biquinoline or phenanthroline which may have a substituent, The binuclear ruthenium complex dye according to any one of claims 1 to 4. A binuclear ruthenium complex dye represented by the general formula (1-3) (provided that the protons (H ⁺ ) of one or more carboxyl groups (—COOH) may be dissociated).

(Wherein R ^{6 to} R ⁹ are independently of each other,

(In the formula, R represents an alkyl group having 1 to 12 carbon atoms, and Z represents an arylene group having 6 to 18 carbon atoms.)
And s, t, u and v each represent an integer of 0 to 4, but s, t, u and v are not 0 simultaneously. When s, t, u or v is 2 or more, the plurality of R ⁶ , the plurality of R ⁷ , the plurality of R ⁸ and the plurality of R ⁹ may be the same or different. X represents a counter ion, and q represents the number of counter ions necessary to neutralize the charge of the complex.
And two

May be the same or different and each represents a chelate-type ligand capable of bidentate coordination independently of each other. )   The dinuclear ruthenium complex dye according to claim 6, wherein Z is a phenylene group. The binuclear ruthenium complex dye according to claim 7, wherein R ^{6 to} R ⁹ are hexyloxyphenyleneethenyl groups.

Is bibiridyl, pyridylquinoline, biquinoline or phenanthroline, which may have a substituent, The binuclear ruthenium complex dye according to any one of claims 6 to 8.   A photoelectric conversion element comprising the binuclear ruthenium complex dye according to claim 1 and semiconductor fine particles.   The photoelectric conversion element according to claim 10, wherein the semiconductor fine particles are at least one semiconductor fine particle selected from the group consisting of titanium oxide, zinc oxide, and tin oxide.   A photochemical battery comprising the photoelectric conversion element according to claim 10.   12. A photochemical battery comprising the photoelectric conversion element according to claim 10 and a counter electrode as an electrode, and an electrolyte layer therebetween.   A method for producing a photoelectric conversion element, comprising a step of immersing semiconductor fine particles in a solution containing the dinuclear ruthenium complex dye according to claim 1. Forming a semiconductor layer containing semiconductor fine particles on a conductive support;
Dipping the semiconductor layer in a solution containing the binuclear ruthenium complex dye according to any one of claims 1 to 9. Semiconductor fine particles sensitized with the binuclear ruthenium complex dye according to any one of claims 1 to 9, and the general formula (2)

(Wherein, Y ^- represents ethylsulfamoyl Fate, 2- (2-methoxy) ethoxyethyl sul fate, or trifluoromethane sulfonate.)
A photochemical battery comprising an electrolyte solution containing an ionic liquid as a main component.