TW201331212A - Binuclear ruthenium complex dye, photoelectric conversion element containing said dye and photochemical cell - Google Patents

Abstract

This invention relates to a binuclear ruthenium complex dye for providing a photoelectric conversion element having high current density and high efficiency, and a photochemical cell. The invention also relates to a photochemical cell with high conversion efficiency, which is furnished with semiconductor minute particles whose sensitivity is enhanced by said binuclear ruthenium complex dye and an electrolyte solution including ion liquid as a main component.

Description

Dinuclear ruthenium complex pigment, photoelectric conversion element having the same, and photochemical battery

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

Solar cells are highly expected for clean regenerative energy sources, and have been targeted at single-crystal lanthanide, polycrystalline lanthanide, amorphous lanthanide solar cells, or compounds such as cadmium sulfide and indium arsenide. The practical use of solar cells is being studied. However, in order to make it popular for home use, any battery suffers from high manufacturing costs, difficulty in securing raw materials, recycling problems, and the need to overcome the problem of large area. However, solar cells have been proposed which are intended to be large-area or low-priced and use organic materials, but the conversion efficiency is about 1%, which is far from the practical distance.

In this case, Grätzel et al., 1991, disclose a photoelectric conversion element and a solar cell using dye-sensitized semiconductor fine particles, and materials and manufacturing techniques necessary for producing the solar cell (see, for example, Non-Patent Document 1 and Patent Document 1). . This battery is a wet solar cell in which a porous titanium oxide film sensitized by an anthraquinone dye is used as a working electrode. The solar cell has the advantage that an inexpensive material can be used without being refined into high purity, so that an inexpensive photoelectric conversion element can be provided, and further, the dye used can be widely absorbed, and the sunlight can be converted into a wavelength range across a wide visible light. Electricity. However, in order to be practical, it is still necessary to further improve the conversion efficiency, and hope to develop A pigment that has a higher absorption coefficient and absorbs light in a longer wavelength range.

In addition, as a metal complex dye which is useful as a photoelectric conversion element, a metal mononuclear complex containing a dipyridyl ligand is disclosed in Patent Document 2, and a polynuclear β-diketone has been disclosed in Non-Patent Document 2 ( --diketonate) complex pigment.

Further, Patent Document 3 discloses a complex complex complex which is a novel complex complex which is excellent in a photoelectric conversion machine which takes out energy of active light such as light and extracts electrons, and has a plurality of metals and a plurality of ligands, and is provided with The bridging ligand (BL) located in the majority of the metal includes a coordination structure having a conjugated heterocyclic ring and a coordination structure having no conjugated heterocyclic ring.

Further, Patent Document 4 and Patent Document 5 proposed by the applicant of the present invention disclose a dinuclear metal complex such as a dinuclear ruthenium complex having a coordination structure of a conjugated heterocyclic ring, and a photoelectric conversion element having high photoelectric conversion efficiency can be obtained. Metal complex pigment.

On the other hand, in the case of using an electrolyte composition as an ionic liquid, Patent Document 6 discloses an electrolyte composition containing an ionic liquid obtained by dissolving a copper complex in an ionic liquid, and photoelectric conversion using the electrolyte composition. Components and dye-sensitized solar cells. However, the conversion efficiency of the dye-sensitized solar cell is not necessarily high.

Further, Patent Document 7 proposed by the applicant of the present application discloses a photochemical battery having a semiconductor particle sensitized by a dinuclear ruthenium complex dye and an electrolyte solution containing an ionic liquid as a main component disclosed in Patent Document 4. A combination of the dinuclear ruthenium complex pigment and an ionic liquid capable of exhibiting high conversion efficiency.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 1-220380

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2003-261536

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2004-359677

[Patent Document 4] International Publication No. 2006/038587

[Patent Document 5] International Publication No. 2011/115137

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2006-107771

[Patent Document 7] International Publication No. 2008/153184

[Non-patent literature]

[Non-Patent Document 1] Nature, Vol. 353, 737, 1991

[Non-Patent Document 2] The latest technology of dye-sensitized solar cells (CMC Co., Ltd., issued on May 25, 2001, 117 pages)

A first object of the present invention is to provide a photoelectric conversion element having a higher current density and higher efficiency, and a dinuclear ruthenium complex dye of a photochemical battery. A second object of the present invention is to provide a photochemical battery having high conversion efficiency, comprising: semiconductor fine particles sensitized by the dinuclear ruthenium complex dye; and an electrolyte solution containing an ionic liquid as a main component.

The present invention relates to the following matters.

(1) a dinuclear ruthenium complex dye represented by the formula (1-1) (only one or a plurality of carboxyl groups (-COOH) protons (H ⁺ ) may also be cleaved);

(wherein R ¹ and R ² each independently represent an aryl group or a heteroaryl group which may have a substituent, and n and m represent an integer of 0 to 4, but n is not 0 different from m; further, n or m When it is 2 or more, a plurality of R ¹ and a plurality of R ² may be the same or different; X represents a relative ion, and q represents the number of relative ions necessary for neutralizing the charge of the complex; They may be the same or different, each independently representing a chelating-type ligand capable of bidentate coordination.

(2) a dinuclear ruthenium complex dye represented by the formula (1-2) (only one or a plurality of carboxyl groups (-COOH) protons (H ⁺ ) may also be dissociated);

(wherein 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 represent an integer of 0 to 4, but when n, m, o and p are different 0; further, 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 or different; X represents a relative ion, and q represents a The number of relative ions necessary to neutralize the charge of the complex; again, 2 They may be the same or different and independently represent a chelating-type ligand capable of bidentate coordination.

(3) a dinuclear ruthenium complex dye represented by the formula (1-3) (only one or a plurality of carboxyl groups (-COOH) protons (H ⁺ ) may also be dissociated);

(wherein R ⁶ to R ⁹ each independently represent an alkoxy extended aryl vinyl group represented as follows

(wherein, R represents an alkyl group having 1 to 12 carbon atoms, Z represents an exoaryl group having 6 to 18 carbon atoms), and s, t, u and v represent an integer of 0 to 4, but s, t, u And v is not 0 at the same time; when s, t, u or v is 2 or more, a plurality of R ⁶ , a plurality of R ⁷ , a plurality of R ⁸ and a plurality of R ⁹ may be the same or different; X represents a relative Ion, q represents the number of relative ions necessary to neutralize the charge of the complex; in addition, 2 They may be the same or different, each independently representing a chelating-type ligand capable of bidentate coordination.

(4) A photoelectric conversion element comprising the dinuclear ruthenium complex dye and the semiconductor fine particles according to any one of (1) to (3).

(5) The photoelectric conversion element according to (4), wherein the semiconductor fine particles are at least one selected from the group consisting of titanium oxide, zinc oxide, and tin oxide.

(6) A photochemical battery comprising the photoelectric conversion element according to (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 of producing a photoelectric conversion element, comprising the step of immersing semiconductor fine particles in a solution containing the dinuclear ruthenium complex dye according to any one of (1) to (3).

(9) A method of producing a photoelectric conversion element, comprising the steps of: forming a semiconductor layer containing semiconductor fine particles on a conductive support; and immersing the semiconductor layer in a content containing (1) to (3) A solution of a dinuclear ruthenium complex pigment.

(10) A photochemical cell comprising: a semiconductor microparticle obtained by sensitizing the dinuclear ruthenium complex dye according to any one of (1) to (3); and an ion represented by the general formula (2) An electrolyte solution in which a liquid is a main component;

(wherein Y ^- represents ethyl sulfate, 2-(2-methoxy)ethoxyethyl sulfate, or trifluoromethanesulfonate).

According to the present invention, it is possible to provide a photoelectric conversion element having a higher current density and higher efficiency, and a binuclear ruthenium complex dye of a photochemical battery. Further, according to the present invention, it is possible to provide a photochemical battery having high conversion efficiency, comprising: semiconductor fine particles sensitized by the dinuclear ruthenium complex dye; and an electrolyte solution containing an ionic liquid as a main component. Moreover, this photochemical battery is highly stable, has high durability, and has high photoelectric conversion efficiency, and is considered to be suitable for practical use.

<The first dinuclear ruthenium complex dye (1) and the second dinuclear ruthenium complex dye (2) of the present invention>

The first dinuclear ruthenium complex dye (1) of the present invention is represented by the above formula (1-1). The second dinuclear ruthenium complex dye (2) of the present invention is represented by the above formula (1-2).

In the formula (1-1), n and m each represent the number of the substituents R ¹ and R ² and are an integer of 0 to 4, preferably an integer of 0 to 2, more preferably 0 or 1, especially Good for 1. Only n is different from m when it is 0. In the formula (1-2), n, m, o and p each represent the number of the substituents R ¹ , R ² , R ³ and R ⁴ and are an integer of 0 to 4, preferably an integer of 0 to 2, More preferably, it is 0 or 1, and 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 formulae (1-1) and (1-2), the positions of the substituents R ¹ and R ² are not particularly limited, and are preferably 2,2'-bibenzimidazole (bibenzimidazolato) which is a cross-linking ligand. The 5 or 6 position, and the 5' or 6' position are preferred. Further, in the general formula (1-2), the positions of the substituents R ³ and R ⁴ are not particularly limited, and it is preferably ⁴ or more positions of the 2,2'-bipyridine of the ligand.

Further, in the general formula (1-1), when n or m is 2 or more, a plurality of R ¹ and a plurality of R ^{2 's} 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 or different.

R ¹ and R ² in the formula (1-1), and R ¹ to R ⁴ in the formula (1-2) represent an aryl group or a heteroaryl group which may have a substituent, the aryl group or the heteroaryl group The base may, for example, be a phenyl group, a naphthyl group, an anthracenyl group, a condensed tetraphenyl group, a fused pentaphenyl group, a fluorenyl group, a fluorenyl group, a phenanthryl group Chrysenyl group, picenyl group, fluorenyl group, pentaphelenyl group, dibenzophenanthrenyl group, thienyl group, furyl group, pyrrolyl group, thiazolyl group, Azyl, imidazolyl, isothiazolyl, iso Azyl, pyrazolyl, thiazolyl, triazolyl, Diazolyl, thiadiazolyl, benzofuranyl, benzopyrrolyl, benzothiazolyl, benzo Azolyl, benzimidazolyl, benzisothiazolyl, benziso Azolyl, benzopyrazolyl, benzothienyl, bithiophenyl, and the like. R ¹ and R ² in the formula (1-1) and R ¹ to R ⁴ in the formula (1-2) are preferably a hetero atom having a sulfur atom which may have a substituent, particularly A thienyl group, a bithienyl group or a benzothienyl group which may have a substituent.

R ¹ and R ² in the formula (1-1), and a substituent of R ¹ to R ⁴ in the formula (1-2), for example, a linear or branched carbon atom having 1 to 18 carbon atoms The base may, for example, be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a decyl group, an eleven group, a dodecyl group, a thirteen group group, a tetradecyl group, Fifteen bases, sixteen bases, seventeen bases, eighteen bases, etc. Further, the number or position of the substituents is not particularly limited, and adjacent groups may be bonded to each other to form a ring.

R ¹ and R ² in the formula (1-1) and R ¹ to R ⁴ in the formula (1-2) are, for example, the following (RA) to (RC).

(wherein R _S1 represents a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms.)

Represents the formula (1-1) in the R ¹ and R ^2, and general formula (1-2) in the R ¹ and R ^2, R _S1 based is suitably a hydrogen atom, or a methyl group of the formula (RA) group It is better. R ³ and R ⁴ in the formula (1-2) are preferably a group represented by the formula (RB) of an R _S1 -based hydrogen atom or an alkyl group having 1 to 6 carbon atoms, or a group represented by the formula (RC). It is better.

In the general formula (1-1) and the general formula (1-2), two They may be the same or different, and each independently represents a chelating-type ligand capable of bidentate coordination, and is not particularly limited, and is preferably bipyridine, pyridylquinoline, biquinoline or phenanthroline which may have a substituent. . The substituent is, for example, a linear or branched alkyl group having 1 to 18 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group and a decyl group. , thiol, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, and so on. Further, the number or position of the substituents is not particularly limited, and adjacent groups may be bonded to each other to form a ring.

For example: (NN-A)~(NN-D) below.

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

Preferably, it is preferably a group represented by the formula (NN-A) of the R _S2 hydrogen atom or an alkyl group having 1 to 8 carbon atoms, or a group represented by the formula (NN-B).

Further, X represents a relative ion such as: hexafluorophosphate ion, perchlorate ion, tetraphenylboronic acid ion, tetrafluoroboric acid ion, trifluoromethanesulfonate ion, thiocyanate ion, sulfate ion, nitrate ion, halide Ionic, etc., but preferably hexafluorophosphate ion, tetrafluoroboric acid ion, trifluoromethanesulfonate ion, nitrate ion, halide ion, more preferably hexafluorophosphate ion, tetrafluoroborate ion, nitrate ion, iodide ion. q represents the number of relative ions necessary to neutralize the charge of the complex.

Specific compounds of the dinuclear ruthenium complex dye (1) and the binuclear ruthenium complex dye (2), for example, the following compounds (A-1) to (A-6). Further, the formula (A-1) ~ (A -6) in the H may be out of -COOH, -COO ^- may also be -COOH.

The dinuclear ruthenium complex dye (1) and the binuclear ruthenium complex dye (2) of the present invention can be synthesized by referring 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.

(in the formula, And R ¹ , R ² , n and m are synonymous with the foregoing. X ^- represents a monovalent anion of a relative ion, Y represents a halogen atom, and W represents a neutral molecule such as a water molecule, an alcohol molecule such as methanol or ethanol, or acetone. Further, cod represents 1,5-cyclooctadiene. )

Further, the counter ion (X) is not limited to the monovalent anion, and the other may 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.

(in the formula, R ¹ to R ⁴ , n, m, o and p are synonymous with the foregoing. X ^- represents a monovalent anion of a relative ion, and Y represents a halogen atom. Further, cod represents 1,5-cyclooctadiene. )

Further, the counter ion (X) is not limited to the monovalent anion, and the other may be synthesized in the same manner.

Further, one of the mononuclear ruthenium complexes is temporarily synthesized via a mononuclear ruthenium complex precursor, and the synthetic intermediate thereof, that is, the mononuclear ruthenium complex represented by the general formula (MI) is a novel compound;

(in the formula, R ¹ , R ² , n, m, X and q are synonymous with the foregoing. )

Further, in the dinuclear ruthenium complex dyes (1) and (2) of the present invention, one or a plurality of protons (H ⁺ ) of a plurality of carboxyl groups (-COOH) may be dissociated. The dissociation of protons (H ⁺ ) is mainly achieved by adjusting the pH of the solution.

<The third dinuclear ruthenium complex dye (3) of the present invention>

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

In the 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 an integer of 0 to 4, preferably an integer of 0 to 2. More preferably, it is 0 or 1, and 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 formula (1-3), the positions of the substituents R ⁶ and R ⁷ are not particularly limited, and are preferably 5 or 6 positions of 2,2'-bibenzimidazole which is a cross-linking ligand, and 5' Bit or 6' bit is preferred. Further, the positions of the substituents R ⁸ and R ⁹ are not particularly limited, and it is preferred that the 4 position and the 4' position of the 2,2'-bipyridine which is a ligand group are preferable.

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

R ⁶ to R ⁹ in the formula (1-3) represent a group represented by the following

(wherein R represents an alkyl group having 1 to 12 carbon atoms, and Z represents an exoaryl group having 6 to 18 carbon atoms). R, for example, 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 or an octyl group, preferably a linear or branched form. The alkyl group having 1 to 6 carbon atoms is preferred. Z, for example, a phenyl group, a tolyl group, a xylylene group, a mesitylene group, a phenylene group, a naphthyl group, a fluorenyl group, and the like, and a aryl group having 6 to 18 carbon atoms, preferably stretching Phenyl is preferred.

R ⁶ to R ⁹ in the formula (1-3) is preferably a hexyloxyphenylene group.

In the general formula (1-3), 2 They may be the same or different and each independently represents a chelating-type ligand capable of bidentate coordination, and is not particularly limited, and is preferably bipyridine, pyridylquinoline, biquinoline or brown which may have a substituent. Porphyrin. a substituent thereof, for example, a linear or branched alkyl group having 1 to 18 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, Mercapto, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, and the like. Further, the number or position of the substituents is not particularly limited, and adjacent groups may be bonded to each other to form a ring.

For example: (NN-A)~(NN-D) below.

(wherein R _S2 represents a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms.) It is preferably a group represented by the formula (NN-A) of the R _S2 hydrogen atom or a carbon atom number of 1 to 18, more preferably an alkyl group having 1 to 8 carbon atoms, or a formula (NN-B) The base is preferred. In a certain embodiment, a group represented by the formula (NN-A) which is preferably a hydrogen atom of R _{S2 type} or an alkyl group having 1 to 18 carbon atoms and more preferably 1 to 8 carbon atoms is preferred.

Further, X represents a relative ion, and examples thereof include hexafluorophosphate ion, perchloric acid ion, tetraphenylboronic acid ion, tetrafluoroboric acid ion, trifluoromethanesulfonate ion, thiocyanate ion, sulfate ion, nitrate ion, halogenation. The ion or the like is preferably a hexafluorophosphate ion, a tetrafluoroborate ion, a trifluoromethanesulfonate ion, a nitrate ion, a halide ion, and more preferably a hexafluorophosphate ion, a tetrafluoroborate ion, a nitrate ion, or an iodide. ion. q represents the number of relative ions necessary to neutralize the charge of the complex.

Specific compounds of the dinuclear ruthenium complex dye (3), for example, the following compounds (A-7) and (A-8). Further, the formula (A-7) ~ (A -8) in the H may be out of -COOH, -COO ^- may also be -COOH.

The dinuclear ruthenium complex dye (3) of the present invention can be referred to the International Publication No. 2011/115137. The method is synthesized.

Further, in the binuclear ruthenium complex dye (3) of the present invention, the proton (H ⁺ ) of one or a plurality of carboxyl groups (-COOH) may be dissociated. The dissociation of protons (H ⁺ ) is achieved primarily by adjusting the pH of the solution.

<Photoelectric Conversion Element and Photochemical Battery of the Invention>

The photoelectric conversion element of the present invention comprises the above-described dinuclear ruthenium complex dye and semiconductor fine particles. The dinuclear ruthenium complex dye is adsorbed on the surface of the semiconductor fine particles, and the semiconductor fine particles are sensitized by the dinuclear ruthenium complex dye. Further, the binuclear ruthenium complex pigment may be used singly or in combination of two or more.

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

The conductive electrode is preferably a transparent electrode formed on a transparent substrate. A conductive agent such as a metal such as gold, silver, copper, platinum or palladium, an indium oxide compound represented by tin-doped indium oxide (ITO), or a tin oxide compound represented by fluorine-doped tin oxide (FTO). , zinc oxide compounds, and the like.

Semiconductor particles, such as titanium oxide, zinc oxide, tin oxide, indium oxide, antimony oxide, tungsten oxide, vanadium oxide and other metal oxides; barium titanate, calcium titanate, barium titanate, potassium citrate and other composite oxides Metal sulfides such as cadmium sulfide and barium sulfide; metal selenides such as cadmium selenide; metal sulfides such as cadmium telluride; metal phosphides such as gallium phosphide; and metal arsenides such as gallium arsenide. The semiconductor fine particles are preferably metal oxides, and more preferably titanium oxide, zinc oxide, tin oxide or a mixture of one or more of them. Further, these semiconductor fine particles may be used singly or in combination of two or more.

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

The semiconductor microparticles sensitized by the dinuclear ruthenium complex pigment (semiconductor microparticles adsorbed with the dinuclear ruthenium complex dye) can be contacted with the semiconductor microparticles by, for example, a solution obtained by dissolving the dinuclear ruthenium complex pigment in a solvent. Manufactured by (for example, coating, dipping, etc.) (for example, refer to International Publication No. 2006/038587 number). Further, it is preferred to wash with various solvents after the contact and to make the drying ideal.

A method of adsorbing a dinuclear ruthenium complex dye on a semiconductor fine particle, wherein a semiconductor layer (semiconductor particle film) containing semiconductor fine particles is formed on a conductive support, and then immersed in a solution containing a dinuclear ruthenium complex dye The method. The semiconductor layer can be formed by coating a paste of semiconductor fine particles on a conductive support and heating and calcining. After immersing in the dye solution, the conductive support on which the semiconductor layer is formed is washed and dried.

a solvent for the dye solution, for example, water; an alcohol such as methanol, ethanol, isopropanol, tert-butanol or ethylene glycol; a nitrile such as acetonitrile or propionitrile; N,N-dimethylacetamide, N, a guanamine such as N-dimethylformamide; a urea such as N-methylpyrrolidone; an oxime such as dimethyl hydrazine, preferably water, an alcohol, a nitrile, and more preferably water or ethanol. , isopropanol, tert-butanol, acetonitrile. Further, these solvents may be used singly or in combination of two or more.

The concentration of the pigment in the solution is preferably 0.001 mmol/l~ the saturated concentration of the dye of the complex of the present invention, more preferably 0.001 to 100 mmol/l, especially preferably 0.01 to 10 mmol/l, more preferably 0.05~ 1.0 mmol/l.

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

The temperature at which the dye is adsorbed is usually set to 0 to 80 ° C, preferably 20 to 40 ° C. The time during which the dye is adsorbed (the time of immersion in the dye solution) is appropriately determined depending on 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 and the counter electrode of the present invention described above are used as electrodes, and have an electrolyte layer therebetween. Further, 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 it is combined with a photoelectric conversion element to form a photochemical battery. A substrate having a conductive layer similar to the above-described conductive electrode may be used as the counter electrode. However, if a metal plate itself is used, it is not necessary to have a substrate. The conductive agent used for the counter electrode is, for example, a metal such as platinum, carbon, or a conductive metal oxide such as fluorine-doped tin oxide.

The electrolyte (redox pair) is not particularly limited, and any publicly known one can be used. For example: iodine and iodide (for example: metal iodide such as lithium iodide or potassium iodide, or tetraammonium iodide, tetrapropylammonium iodide, pyridinium iodide salt, imidazolium iodide salt, etc. Combination of iodide), combination of bromine and bromide, combination of chlorine and chloride, combination of alkyl viologen and its reducing body, benzoquinone/hydroquinone, iron(II) ion/iron (III Transition ion pair, such as ion, copper (I) ion / copper (II) ion, manganese (II) ion / manganese (III) ion, cobalt ion (II) / cobalt ion (III), iron (II) cyanide /iron (III) iron cyanide, cobalt (II) chloride / cobalt (III) tetrachloride, cobalt (II) tetrabromide / cobalt (III) tetrabromide, ruthenium (II) hexachloride / hexachlorochloride Antimony (III), cerium (II) hexacyanohydride / cerium (III) hexacyanohydride, cerium (II) hexachloride / cerium (III) hexachloride, cerium (III) hexachloride / hexachlorochloride Antimony (IV), antimony hexachloride (IV) / antimony hexachloride (V), antimony hexachloride (III) / antimony hexachloride (IV), antimony hexachloride (IV) / antimony hexachloride (V) a combination of equimolar ions, a transition metal such as cobalt, iron, ruthenium, manganese, nickel or ruthenium, and a conjugate of bipyridine or a derivative thereof, a bitripyridine or a derivative thereof, a morphine or a derivative thereof a complex formed by a heterocycle and a derivative thereof, a ferrocene/ferrocene ion ion, a cobaltocene/ferrocene salt ion, a cyclopentadiene/halocene salt ion, etc. A derivative of a derivative and a metal, a porphyrin compound, or the like. An ideal electrolyte is an electrolyte that combines iodine with an iodide of lithium iodide or a tertiary ammonium compound. The state of the electrolyte may be a liquid obtained by dissolving in an organic solvent, or may be a so-called colloidal electrolyte or a solid electrolyte impregnated with a molten salt or a polymer matrix.

Examples of the solvent of the electrolyte include water, alcohols, nitriles, chain ethers, cyclic ethers, chain esters, cyclic esters, chain amides, cyclic guanamines, and chain oximes. Classes, cyclic guanidines, chain ureas, cyclic ureas, amines, and the like. In addition, the solvent is not limited to these, and may be used alone or in combination of two or more.

In an embodiment, the electrolyte of the photochemical battery is an electrolyte solution containing the ionic liquid represented by the above formula (2) as a main component. That is, the photochemical battery of the present invention has: The dinuclear ruthenium complex dye (1), (2) or (3) sensitized semiconductor microparticles; and the electrolyte solution containing the ionic liquid represented by the above formula (2) as a main component. The electrolyte solution is formed, for example, only by an ionic liquid, or an ionic liquid and a redox pair.

Specific compounds of the aforementioned ionic liquid, for example: 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium (2-(2-methoxy)ethoxy B Base sulfate), or 1-ethyl-3-methylimidazolium trifluoromethanesulfonate. Further, the plasma liquid may be used singly or in combination of two or more.

An ideal aspect of the case where the electrolyte of the photochemical battery is an electrolyte solution containing the ionic liquid represented by the above formula (2) as a main component,

(1) Combination of dinuclear ruthenium complex pigment (A-2) and 1-ethyl-3-methylimidazolium ethyl sulfate

(2) Combination of dinuclear ruthenium complex pigment (A-2) and 1-ethyl-3-methylimidazolium (2-(2-methoxy)ethoxyethyl sulfate)

(3) Combination of dinuclear ruthenium complex pigment (A-2) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate

(4) Combination of dinuclear ruthenium complex pigment (A-3) and 1-ethyl-3-methylimidazolium ethyl sulfate

(5) Combination of dinuclear ruthenium complex pigment (A-3) and 1-ethyl-3-methylimidazolium (2-(2-methoxy)ethoxyethyl sulfate)

(6) Combination of dinuclear ruthenium complex pigment (A-3) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate

(7) Combination of dinuclear ruthenium complex pigment (A-4) and 1-ethyl-3-methylimidazolium ethyl sulfate

(8) Combination of dinuclear ruthenium complex pigment (A-4) and 1-ethyl-3-methylimidazolium (2-(2-methoxy)ethoxyethyl sulfate)

(9) Combination of dinuclear ruthenium complex pigment (A-4) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate

(10) Combination of dinuclear ruthenium complex pigment (A-5) and 1-ethyl-3-methylimidazolium ethyl sulfate

(11) Combination of dinuclear ruthenium complex pigment (A-5) and 1-ethyl-3-methylimidazolium (2-(2-methoxy)ethoxyethyl sulfate)

(12) Combination of dinuclear ruthenium complex pigment (A-5) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate

(13) Combination of dinuclear ruthenium complex pigment (A-7) and 1-ethyl-3-methylimidazolium ethyl sulfate

(14) Combination of dinuclear ruthenium complex pigment (A-7) and 1-ethyl-3-methylimidazolium (2-(2-methoxy)ethoxyethyl sulfate)

(15) Group of dinuclear ruthenium complex pigment (A-7) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate Hehe.

Preferably, the electrolyte solution preferably contains a redox pair. The redox pair to be used is not particularly limited, for example, (1) iodine and iodide (for example, metal iodide such as lithium iodide or potassium iodide; tetrabutylammonium iodide, tetrapropylammonium iodide, pyridinium iodide salt; a combination of a 4-grade ammonium compound such as iodide iodide, and (2) a bromine and a bromide (for example, a metal bromide such as lithium bromide or potassium bromide; tetrabutylammonium bromide; tetrapropylammonium bromide; , a combination of a bromide of a pyridinium bromide salt, a 4-grade ammonium compound such as an imidazolium bromide, and (3) a chloride and a chloride (for example, a metal chloride such as lithium chloride or potassium chloride; tetrabutyl chloride; a combination of ammonium, tetrapropylammonium chloride, pyridinium chloride chloride, chloride of a 4-grade ammonium compound such as imidazolium chloride, (4) a combination of an alkyl viologen and its reducing body, (5) Benzoquinone/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 pair such as ion (III)), (6) iron (II) iron cyanide / iron (III) cyanide, cobalt (II) chloride / cobalt (III) tetrachloride, cobalt tetrabromide (II) ) / cobalt tetrachloride (III), cerium (II) hexachloride / cerium (III) hexachloride, six Bismuth (II) / hexacyanoquinone (III), antimony (II) hexachloride / antimony (III) hexachloride, antimony (III) hexachloride / antimony hexachloride (IV), hexachlorochloride Combination of staging ions such as cerium (IV)/cerium hexachloride (V), cerium (III) hexachloride/cerium hexachloride (IV), cerium hexachloride (IV)/cerium hexachloride (V) And (7) a transition metal such as cobalt, iron, ruthenium, manganese, nickel or ruthenium, and a conjugated heterocyclic ring such as bipyridine or a derivative thereof, a bitripyridine or a derivative thereof, a phenanthroline or a derivative thereof, and a derivative thereof Complexes, (8) ferrocene/ferrocene salt ion, ferrocene/ferrocene salt, cyclopentadiene/monopol salt and other cyclopentadiene and their derivatives and metals The complex of the (9) porphyrin compound is preferably a redox couple as recited in the above (1). Further, these redox couples may be used alone or in combination of two or more. The amount of these redox couples used can be appropriately determined.

The photochemical battery of the present invention can be produced by a conventional method.

For example, as described above, a paste of semiconductor fine particles such as an oxide is applied onto a transparent electrode and heated and calcined to form a thin film of semiconductor fine particles. When the thin film of the semiconductor fine particles is titanium oxide, for example, at a temperature 450~500 °C, heating time 30 minutes or calcination at 400~550 °C for 0.5~1 hour. The transparent electrode to which the film is attached is immersed in a dye solution (a solution containing the dinuclear ruthenium complex dye of the present invention), and a dye is carried thereon to prepare a photoelectric conversion element. Further, the photoelectric conversion element is combined with a transparent electrode in which platinum or carbon is vapor-deposited as a counter electrode, and an electrolyte solution is filled therebetween, whereby the photochemical battery of the present invention can be produced.

[Examples]

The invention is illustrated in more detail by the following examples, but the scope of the invention is not limited thereto.

Further, the abbreviation in the embodiment is as follows.

Bpy; 2,2'-bipyridine

Phen; 1,10-morpholine

Cod; 1,5-cyclooctadiene

dtBubpy; 4,4'-di-t-butyl-2,2'-bipyridine

H ₂ dcbpy; 2,2'-bipyridyl-4,4'-dicarboxylic acid

Etcbpy; 2,2'-bipyridyl-4,4'-dicarboxylic acid diethyl ester

BiBzImH ₂ ; 2,2'-bisbenzimidazole

MTBiBzImH ₂ ; 5,5'-bis(5-methylthien-2-yl)-2,2'-bisbenzimidazole

BisBiTbpy; 4,4'-bis([2,2'-bithiophene]-5-yl)-2,2'-bipyridine

BisBzTbpy; 4,4'-bis(benzo(b)thiophene)-2-yl)-2,2'-bipyridine

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

Example A1 (Synthesis of a binuclear ruthenium complex dye (A1a))

Commercially available H ₂ dcbpy (5.44 g, 22.3 mmol), concentrated sulfuric acid (10 mL), and 130 mL of ethanol were placed in a 500 mL three-necked flask under a nitrogen atmosphere, and refluxed overnight. The reaction solution was allowed to cool, neutralized and filtered. The filtrate was washed with hot water and recrystallized from ethanol/water (95:5). After filtration of the crystals and drying in vacuo, Etcbpy 4.92 g was obtained.

Next, commercially available ruthenium chloride (1.18 g, 4.51 mmol), Etcbpy (2.64 g, 8.79 mmol) and ethanol (500 mL) were placed in a 1000 mL three-necked flask under an argon atmosphere and refluxed for 7 hours to effect a reaction. The reaction solution was allowed to cool, filtered, and dried in vacuo to give _{&lt;RTIID=0.0& gt}; Further, the filtrate was concentrated under reduced pressure, and then 300 mL of 2mol/L hydrochloric acid was added to the concentrate, and the mixture was stirred at room temperature for 5 minutes and then filtered. The filtrate was washed with water, recrystallized from ethanol/dichloromethane (10:3), filtered, and dried in vacuo to give &quot;Ru(Etcbpy) ₂ Cl ₂ ] 1.34 g, total 2.98 g.

Then, [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, and stirred at room temperature. hour. 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 stirred at room temperature for 5 min and then filtered. The filtrate was washed with diethyl ether and dried in vacuo to give [[rho][Etcbpy] ₂ (H ₂ O) ₂ ] (OTf) ₂ 1.62 g.

Under a 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 a 20 mL Schlenk tube and degassed. Thereafter, the mixture was refluxed for 14 minutes while stirring under microwave irradiation at 2.45 GHz. After cooling the reaction mixture, 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, and 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 stirred solution was filtered to obtain [Ru(dtBubpy) ₂ (MTBiBzImH ₂ )] (PF ₆ ) ₂ 0.209 g.

[Ru(dtBubpy) ₂ (MTBiBzImH ₂ )](PF ₆ ) ₂ (0.200 g, 0.147 mmol), 28% sodium methoxide methanol solution 0.051 mL, N, N- was added to a 100 mL three-necked flask under an argon atmosphere. 24 mL of dimethylformamide was stirred at room temperature for 5 minutes. Then, [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 mixture, followed by degassing. Thereafter, the mixture was refluxed for 40 minutes while stirring under microwave irradiation at 2.45 GHz. The reaction solution was allowed to stand to cool, then concentrated under reduced pressure. &lt;RTI ID=0.0&gt;&gt; After cooling the reaction mixture and filtering, 30 mL of methanol and 110 mL of water were added to the filtrate, and 0.7 mL of a 0.79 mol/L aqueous hydriodic acid solution was added to form a precipitate. The precipitate was filtered, purified by ODS column chromatography, concentrated under reduced pressure, and dried in vacuo. After adding 70 mL of water and 0.8 mL of 0.2 mol/L sodium hydroxide aqueous solution to make a solution, 0.79 mol/L hydriodic acid was added. A precipitate of 0.4 mL of an aqueous solution was formed. The precipitate was filtered, and washed with a 0.79 mmol/L aqueous solution of hydroiodic acid to obtain a nuclear ruthenium complex (A1a).

The proton-undissociated structure of the representative structure of the binuclear ruthenium complex dye is as shown in the formula (A1a). The complex pigment also has one or a plurality of proton dissociates. Further, depending on the position of the 5-methylthiophen-2-yl group, an isomer may be present.

Reference example A1

The binuclear ruthenium complex pigment (A3) was synthesized by a known method.

Example A3-1 (Production of Porous Titanium Oxide Electrode)

A catalyst layer-forming titanium oxide paste PST-18NR was used as a transparent layer, and PST-400C was used as a diffusion layer. The coating was carried out using a screen printing machine on a transparent conductive glass electrode manufactured by Asahi Glass Co., Ltd. The obtained film was aged for 5 minutes in a gas atmosphere at 25 ° C and a relative humidity of 60%, and the cooked film was calcined at 450 ° C for 30 minutes. The same operation was repeated for the cooled film until a predetermined thickness was obtained, and a 16 mm ² porous titanium oxide electrode was produced.

Example A3-2 (Production of Porous Titanium Oxide Electrode Adsorbed with Pigment)

The porous titanium oxide electrode was immersed in a 0.2 mmol/l dye solution (solvent: 2-propanol) of the binuclear ruthenium complex dye at 30 ° C for a predetermined period of time and dried to obtain a porous titanium oxide electrode to which a pigment was adsorbed.

Example A3-3 (Production of Photochemical Battery)

The porous titanium oxide electrode to which the dye was obtained as described above was superposed on the platinum plate (opposite pole). Then, the electrolyte solution (dissolved 1-methyl-3-propylimidazolium iodide, iodine, and tetrabutylammonium tetracyanoborate in gamma-butyrolactone to a concentration of 0.6 mol/l, respectively. 0.05 mol/l, 0.5 mol/l) was impregnated into the gap between the two electrodes by capillary action to prepare a photochemical battery.

Example A3-4 (Evaluation of Photochemical Battery)

The simulated sunlight of 100 mW/cm ^{2 was} irradiated with a solar simulator manufactured by Yinghong Seiki Co., Ltd., and the current density included in the photoelectric conversion efficiency of the obtained photochemical battery was measured.

As a result, current density (mA / cm ²⁾ to a binuclear ruthenium complex dye (A1a) is 12.21mA / cm ^2, Reference Example A1 of the binuclear ruthenium complex dye (A3) of 10.97mA / cm ^2. That is, a pigment having a heteroaryl group (here, a 5-methylthiophen-2-yl group at the 6-position and the 6-position) is introduced to the cross-linking ligand 2,2'-bisbenzimidazole, which is high. Current density. From this, it is understood that the dinuclear ruthenium complex dye of the present invention can be a pigment capable of producing a high performance photochemical battery.

Example B1a (Synthesis of Binuclear Complex Complex (B1a)) Synthesis of (4,4'-bis([2,2'-bithiophene]-5-yl)-2,2'-bipyridine (BisBiTbpy))

Add 5-(4,4,5,5-tetramethyl-1,3,2-diox in a 100 mL three-necked flask under argon atmosphere Heteroborane-2-yl)-2,2'-bithiophene (3.917 g, 13.40 mmol), 4,4'-dibromo-2,2'-bipyridine (2.002 g, 6.376 mmol), potassium carbonate ( 7.023 g, 50.81 mmol), N,N-dimethylformamide 50 mL and degassed. Thereafter, hydrazine (triphenylphosphine) palladium (0) (0.736 g, 0.637 mmol) was added and degassed. Thereafter, the reaction was carried out at 100 ° C for 6.5 hours. After allowing to cool, the reaction mixture was filtered, and the filtrate was washed with N,N-dimethylformamide, water, methanol and dried in vacuo to afford BisBiTbpy 2.854g.

Synthesis of (5,5'-bis(5-methylthien-2-yl)-2,2'-bisbenzimidazole (MTBiBzImH ₂ ))

4-Bromo-1,2-diaminobenzene (1.821 g, 9.733 mmol), 5-methylthiopheneboronic acid (1.605 g, 11.30 mmol), potassium carbonate (19.50) were placed in a 500 mL three-necked flask under an argon atmosphere. g, 141.1 mmol), toluene 250 mL and degassed. Then hydrazine (triphenylphosphine) palladium (0) (0.285 g, 0.247 mmol) was added and degassed. Thereafter, it was reacted at 85 ° C for 25.5 hours. After allowing to cool, the reaction mixture was filtered, and the filtrate was evaporated. A dry product and 135 mL of ethyl acetate were added to a 300 mL eggplant-shaped flask, and a 5 mol/L hydrochloric acid aqueous solution was added dropwise with stirring to form a precipitate. The precipitate was collected by filtration, washed with ethyl acetate and dried in vacuo. The dried product was separated into 50 mL of ethyl acetate and 20 mL of a 2 mol/L aqueous sodium hydroxide solution, and the ethyl acetate layer was concentrated under reduced pressure and dried in vacuo to give 4-(5-methylthiophen-2-yl)-1. 1,2-diaminobenzene 1.060 g.

4-(5-Methylthiophen-2-yl)-1,2-diaminobenzene (0.535 g, 2.618 mmol), 2,2,2-trichlorobenzene was added to a 100 mL two-necked flask under an argon atmosphere. Ethyl acetimidate methyl ester (0.245 g, 1.387 mmol), ethanol 25 mL and degassed. Thereafter, reflux was allowed for 28 hours. After allowing to cool, the reaction liquid was filtered, and the filtrate was washed with ethanol and dried under vacuum to obtain 0.262 g of MTBiBzImH ₂ .

(Synthesis of dinuclear ruthenium complex pigment (B1a))

Add dichloro-p- in a 100 mL three-necked flask under argon atmosphere A terpene dimer (0.100 g, 0.163 mmol), BisBiTbpy (0.158 g, 0.326 mmol) and N,N-dimethylformamide 50 mL were degassed. Thereafter, the reaction was allowed to proceed at 60 ° C for 4 hours.

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

The obtained reaction liquid was filtered, and the filtrate was concentrated under reduced pressure, dried in vacuo, and purified by ODS column chromatography. Concentration under reduced pressure and drying in vacuo. The purified product was dissolved in 30 mL of methanol and 0.03 mL of a 0.5 mol/L aqueous solution of hexafluorophosphoric acid, and a precipitate was formed by 30 mL of a hexafluorophosphoric acid aqueous solution of pH 2. The precipitate was filtered, and the filtrate was washed with an aqueous solution of hexafluorophosphoric acid (pH 2), and dried in vacuo to give 0.059 g of dinuclear ruthenium complex (B1a).

The proton-undissociated structure of the representative structure of the binuclear ruthenium complex dye is as shown in formula (B1a). The complex pigment also has one or a plurality of proton dissociates. Further, depending on the position of the 5-methylthiophen-2-yl group, there are also isomers.

Example B1b (Synthesis of Binuclear Complex Compound (B1b)) (Synthesis of [Ru(dtBubpy) ₂ Cl ₂ ])

In a 1000 mL three-necked flask, [Ru(cod)Cl ₂ ] _n (2.999 g, 10.70 mmol), dtBubpy (5.755 g, 21.44 mmol) and 300 mL of N,N-dimethylformamide were added and degassed. Thereafter, the mixture was refluxed for 34 minutes while stirring under microwave irradiation at 2.45 GHz. The reaction mixture was allowed to cool and filtered, and the filtrate was concentrated under reduced pressure and dried in vacuo, and then, then, 20% of N,N-dimethylformamide and 250 mL of diethyl ether were added to the mixture, and the mixture was stirred at room temperature for 30 minutes. The stirred suspension was filtered, and the filtrate was washed with diethyl ether and water, and dried in vacuo to give [[rho](dtBubpy) ₂ Cl ₂ ] 7.027 g.

(Synthesis of [Ru(dtBubpy) ₂ (MTBiBzImH ₂ )])

Under a argon atmosphere, [Ru(dtBubpy) ₂ Cl ₂ ] (0.351 g, 0.495 mmol), MTBiBzImH ₂ (0.254 g, 0.595 mmol) and ethylene glycol 21 mL were placed in a 100 mL three-necked flask and degassed. Thereafter, it was refluxed for 14 minutes while stirring under microwave irradiation at 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 a 1.3 mol/L aqueous solution of ammonium hexafluorophosphate was added to the filtrate to form a precipitate. The precipitate was filtered, and the filtrate was dried under vacuum to give [[Lambda]] (dtBubpy) ₂ (MTBiBzImH ₂ )] (PF ₆ ) ₂ 0.590 g.

(Synthesis of dinuclear ruthenium complex pigment (B1b))

Add dichloro-p- in a 300 mL three-necked flask under argon atmosphere A terpene dimer (0.124 g, 0.203 mmol), BisBiTbpy (0.197 g, 0.406 mmol) and N,N-dimethylformamide 62 mL were degassed. Thereafter, the reaction was allowed to proceed at 60 ° C for 4.5 hours. After cooling the reaction mixture, H ₂ dcbpy (0.101 g, 0.411 mmol) was added and degassed again, and the reaction was allowed to stand at 140 ° C for 9 hours. After the reaction solution was allowed to cool, 1.20 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 the reaction was allowed to stand at 170 ° C for 11 hours. The obtained reaction liquid was filtered, and the filtrate was concentrated under reduced pressure, and purified by ODS column chromatography, concentrated under reduced pressure, dried in vacuo, and then dissolved in 100 mL of methanol and 1 mL of 0.5 mol/L aqueous solution of hexafluorophosphoric acid to pH 2 100 mL of an aqueous solution of hexafluorophosphoric acid formed a precipitate. The precipitate was filtered, and the filtrate was washed with an aqueous solution of hexafluorophosphoric acid at pH 2, and then dried in vacuo to obtain a dinuclear ruthenium complex dye (B1b): 0.312 g.

Is a proton-undissociated structure of the representative structure of the binuclear ruthenium complex dye, as in the formula (B1b). The complex pigment also has one or a plurality of proton dissociates. Further, depending on the position of the 5-methylthiophen-2-yl group, there are also isomers.

Example B1c (Synthesis of Binuclear Complex Complex (B1c)) (Synthesis of BisBzTbpy)

To a 200 mL three-necked flask was placed benzo[b]thiophen-2-ylboronic acid (2.417 g, 13.58 mmol) and 4,4'-dibromo-2,2'-bipyridine (2.004 g, under argon atmosphere). 6.383 mmol), potassium carbonate (7.005 g, 50.68 mmol), N,N-dimethylformamide 50 mL and degassed. Thereafter, hydrazine (triphenylphosphine)palladium(0) (0.725 g, 0.627 mmol) was added and degassed. Thereafter, the reaction was allowed to proceed at 100 ° C for 23.5 hours. After allowing to cool, the reaction mixture was filtered, and the filtrate was washed with N,N-dimethylformamide, water, and methanol, and dried under vacuum to obtain BisBzTbpy 1.622g.

(Synthesis of dinuclear ruthenium complex pigment (B1c))

Add dichloro-p- in a 300 mL three-necked flask under argon atmosphere A terpene dimer (0.124 g, 0.203 mmol), BisBzTbpy (0.707 g, 0.406 mmol) and N,N-dimethylformamide 60 mL were degassed. Thereafter, the reaction was allowed to proceed at 100 ° C for 3 hours.

After allowing the reaction mixture to cool, H ₂ dcbpy (0.100 g, 0.412 mmol) was added and degassed again, and the reaction was allowed to stand at 140 ° C for 9 hours. After the reaction mixture was allowed 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 the reaction was allowed to stand at 170 ° C for 4.5 hours.

The obtained reaction solution was filtered, and the filtrate was washed with N,N-dimethylformamide and vacuum dried. dry. The dried sample was purified by ODS column chromatography, concentrated under reduced pressure, dried in vacuo, and then dissolved in 50 mL of methanol, 0.5 mL of 0.5 mol/L aqueous solution of hexafluorophosphoric acid, and 50 mL of hexafluorophosphoric acid aqueous solution at pH 2. Make a precipitate. The precipitate was filtered, and the filtrate was washed with an aqueous solution of hexafluorophosphoric acid (pH 2), and then dried in vacuo to obtain 0.055 g of a dinuclear ruthenium complex (B1c).

The proton-undissociated structure of the representative structure of the binuclear ruthenium complex dye is as shown in formula (B1c). The complex pigment also has one or a plurality of proton dissociates.

Example B1d (Synthesis of Binuclear Complex Complex (B1d))

Add dichloro-p- in a 100 mL three-necked flask under argon atmosphere A terpene dimer (0.100 g, 0.163 mmol), BisBiTbpy (0.158 g, 0.326 mmol) and N,N-dimethylformamide 50 mL were degassed. Thereafter, the reaction was allowed to proceed at 60 ° C for 4 hours.

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

The obtained reaction liquid was filtered, and the filtrate was washed with N,N-dimethylformamide and dried under vacuum. The dried sample was purified by ODS column chromatography, concentrated under reduced pressure, dried in vacuo, and dissolved in 70 mL of methanol, 0.7 mL of 0.5 mol/L aqueous solution of hexafluorophosphoric acid, and hexafluorophosphoric acid at pH 2. 100 mL of an aqueous solution was allowed to precipitate. The precipitate was filtered, and the filtrate was washed with an aqueous solution of hexafluorophosphoric acid at pH 2, and then dried in vacuo to obtain a nuclear ruthenium complex (B1d).

The proton-undissociated structure of the representative structure of the binuclear ruthenium complex dye is as shown in the formula (B1d). The complex pigment also has one or a plurality of proton dissociates.

Reference Example B1 (Synthesis of Binuclear Complex Complex (B3))

The binuclear ruthenium complex pigment (B3) was synthesized by a known method.

Example B3-1 (Production of Porous Titanium Oxide Electrode)

A titanium oxide paste PST-18NR prepared by catalytic polymerization was used as a transparent layer, and PST-400C was used as a diffusion layer, and coated on a transparent conductive glass electrode manufactured by Asahi Glass Co., Ltd. using a screen printing machine. The obtained film was aged for 5 minutes in a gas atmosphere at 25 ° C and a relative humidity of 60%, and the cooked film was calcined at 450 ° C for 30 minutes. For the cooled film, the same operation was repeated until a predetermined thickness was formed, and a porous titanium oxide electrode of 16 mm ^{2 was} produced.

Example B3-2 (Production of Porous Titanium Oxide Electrode Adsorbed with Pigment)

The porous titanium oxide electrode was immersed in a 0.2 mmol/l dye solution (solvent: 2-propanol) of the binuclear ruthenium complex dye at 30 ° C for a predetermined period of time, and dried to obtain a porous titanium oxide electrode to which a pigment was adsorbed.

Example B3-3 (Production of Photochemical Battery)

The porous titanium oxide electrode to which the dye was obtained as described above was superposed on the platinum plate (opposite pole). Then, the electrolyte solution (dissolved 1-methyl-3-propylimidazolium iodide, iodine, and tetrabutylammonium tetracyanoborate in gamma-butyrolactone to a concentration of 0.6 mol/l, respectively. 0.05 mol/l, 0.5 mol/l) was impregnated into the gap between the two electrodes by capillary action to prepare a photochemical battery.

Example B3-4 (Evaluation of Photochemical Battery)

The simulated sunlight of 100 mW/cm ^{2 was} irradiated with a solar simulator manufactured by Yinghong Seiki Co., Ltd., and the current density included in the photoelectric conversion efficiency of the obtained photochemical battery was measured.

As a result, the current density (mA/cm ² ) was as follows.

Dinuclear ruthenium complex pigment (B1a); 11.78 mA/cm ²

Dinuclear ruthenium complex pigment (B1b); 13.01 mA/cm ²

Dinuclear ruthenium complex pigment (B1c); 13.82 mA/cm ²

Dinuclear ruthenium complex pigment (B1d); 13.91 mA/cm ²

Dinuclear ruthenium complex pigment (B3); 11.27 mA/cm ²

As a result, the binuclear ruthenium complex dye (B1a) to (B1d) of the present invention has a current density of about 0.5 to 2.6 mA/cm ² as compared with the existing binuclear ruthenium complex dye (B3) of Reference Example B1. has seen an increase. From this, it is understood that the dinuclear ruthenium complex dye of the present invention can be used as a pigment for producing a higher performance photochemical battery.

Synthesis Example C1 (synthesis of dinuclear ruthenium complex dye (A-2))

The dinuclear ruthenium complex dye (A-2) [dinuclear 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) [dinuclear 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))

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

Synthesis Example C4 (Synthesis of Binuclear Complex Complex (A-5))

The dinuclear ruthenium complex dye (A-5) [dinuclear ruthenium complex dye (B1c)] was synthesized in the same manner as in Example B1c.

Example C1 (Evaluation of photoelectric conversion efficiency) (Production of porous titanium oxide electrode)

A titanium oxide paste PST-18NR (manufactured by Nikko Co., Ltd.) was used as a transparent layer, and PST-400C (manufactured by Nikko Co., Ltd.) was used as a diffusion layer in a transparent conductive glass electrode (Asahi Glass Co., Ltd.) Coated with a screen printing machine. The obtained film was aged for 5 minutes in a gas atmosphere at 25 ° C and a relative humidity of 60%, and the cooked film was calcined at 440 to 460 ° C for 30 minutes. This operation was repeated to prepare a 16 mm ² porous titanium oxide electrode.

(Production of porous titanium oxide electrode with adsorption of pigment)

The dinuclear ruthenium complex dye (A-2) was added to a mixed solvent of t-butanol/acetonitrile (=1:1 (capacity ratio)) to prepare a saturated dye solution of the binuclear ruthenium complex dye. Next, the porous titanium oxide electrode was immersed in the saturated dye solution in a thermostat having an internal temperature of 30 ° C for 5 hours to prepare a porous titanium oxide electrode to which a dye was adsorbed.

(production of photochemical battery)

The obtained porous titanium oxide electrode to which the pigment was adsorbed was superposed on the platinum plate (opposite pole). Then, iodide ion is prepared from 1-ethyl-3-methylimidazolium ethyl sulfate (ionic liquid) with iodized 1-ethyl-3-methylimidazolium salt and iodine (redox couple) An electrolyte solution having a concentration of 1.0 mol/l. Further, the obtained electrolyte solution was impregnated into the gap between the two electrodes by capillary action to prepare a photochemical battery. The conversion efficiency of the fabricated photochemical battery was 3.7%.

Examples C2 to C12, Reference Examples C1 to C4, and Comparative Examples C1 to C12 (Evaluation of Photoelectric Conversion Efficiency)

A photochemical battery was produced in the same manner as in Example C1 except that the dinuclear ruthenium complex dye and the ionic liquid in Example C1 were changed as shown in Table 1, and the conversion efficiency was measured. The binuclear ruthenium complexes (B-1), (B-2) and (B-3) in Comparative Examples C1 to C12 are the following compounds. These results are shown together in Table 1.

【Table 1】

When the conversion efficiency of each of the dinuclear ruthenium complex dyes and 1-ethyl-3-methylimidazolium bistrifluoromethylsulfonyl quinone was 100, the conversion efficiency of each combination is shown in Table 2.

【Table 2】

From the above results, it is understood that the photochemical cell including the semiconductor fine particles sensitized by the specific dinuclear ruthenium complex dye of the present invention and the 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))

The 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) (Production of porous titanium oxide electrode)

A titanium oxide paste PST-18NR (manufactured by Nikko Co., Ltd.) was used as a transparent layer, and PST-400C (manufactured by Nikko Co., Ltd.) was used as a diffusion layer in a transparent conductive glass electrode (Asahi Glass Co., Ltd.) Coated with a screen printing machine. The obtained film was aged for 5 minutes in a gas atmosphere at 25 ° C and a relative humidity of 60%, and the cooked film was calcined at 440 to 460 ° C for 30 minutes. This operation was repeated to prepare a 16 mm ² porous titanium oxide electrode.

(Production of porous titanium oxide electrode with adsorption of pigment)

The dinuclear ruthenium complex dye (A-7) was added to a mixed solvent of t-butanol/acetonitrile (=1:1 (capacity ratio)) to prepare a saturated dye solution of the binuclear ruthenium complex dye. Next, the porous titanium oxide electrode was immersed in the saturated dye solution in a thermostat having an internal temperature of 30 ° C for 5 hours to prepare a porous titanium oxide electrode to which a dye was adsorbed.

(production of photochemical battery)

The obtained porous titanium oxide electrode to which the pigment was adsorbed was superposed on the platinum plate (opposite pole). Then, iodide ion is prepared from 1-ethyl-3-methylimidazolium ethyl sulfate (ionic liquid) with iodized 1-ethyl-3-methylimidazolium salt and iodine (redox couple) An electrolyte solution having a concentration of 1.0 mol/l. Further, the obtained electrolyte solution was impregnated into the gap between the two electrodes by capillary action to prepare a photochemical battery. The conversion efficiency of the fabricated 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 produced in the same manner as in Example D1 except that the binuclear ruthenium complex dye and the ionic liquid in Example D1 were changed as shown in Table 3, and the conversion efficiency was measured. The binuclear ruthenium complexes (B-1), (B-2) and (B-3) in Comparative Examples D1 to D12 are the following compounds. The results of these combinations are shown in Table 3.

【table 3】

When the conversion efficiency of each of the dinuclear ruthenium complex dyes and 1-ethyl-3-methylimidazolium bistrifluoromethylsulfonyl quinone was 100, the conversion efficiency of each combination is shown in Table 4.

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

[Industry Utilization]

According to the present invention, it is possible to provide a photoelectric conversion element having a higher current density and higher efficiency, and a dinuclear ruthenium complex dye of a photochemical battery.

Moreover, according to the present invention, it is possible to provide a photochemical battery having high conversion efficiency, comprising: semiconductor fine particles sensitized by the dinuclear ruthenium complex dye; and an electrolyte solution containing an ionic liquid as a main component. Moreover, this photochemical battery is highly stable, has high durability, and has high photoelectric conversion efficiency, and is considered to be suitable for practical use.

Claims (16)

A binuclear ruthenium complex dye represented by the formula (1-1) (only one or a plurality of carboxyl groups (-COOH) protons (H ⁺ ) can also be dissociated); (wherein R ¹ and R ² each independently represent an aryl group or a heteroaryl group which may have a substituent, and n and m represent an integer of 0 to 4, but n is not 0 different from m; further, n or m When it is 2 or more, a plurality of R ¹ and a plurality of R ² may be the same or different; X represents a relative ion, and q represents the number of relative ions necessary for neutralizing the charge of the complex; They may be the same or different, each independently representing a chelating-type ligand capable of bidentate coordination. a binuclear ruthenium complex dye represented by the formula (1-2) (only one or a plurality of carboxyl groups (-COOH) protons (H ⁺ ) can also be dissociated); (wherein 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 represent an integer of 0 to 4, but when n, m, o and p are different 0; further, 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 or different; X represents a relative ion, and q represents a The number of relative ions necessary to neutralize the charge of the complex; again, 2 They may be the same or different and independently represent a chelating-type ligand capable of bidentate coordination. The dinuclear ruthenium complex dye according to claim 1 or 2, wherein R ¹ and R ² in the formula (1-1) or R ¹ to R ⁴ in the formula (1-2) It is a heteroaryl group containing a sulfur atom which may have a substituent. The dinuclear ruthenium complex dye according to item 3 of the patent application, wherein R ¹ and R ² in the formula (1-1) or R ¹ to R ⁴ in the formula (1-2) are also A thienyl group, a bithienyl group or a benzothienyl group which may have a substituent. For example, the dinuclear ruthenium complex pigment of claim 1 or 2, wherein It is a bipyridine, a pyridylquinoline, a biquinoline or a morpholine which may also have a substituent. A binuclear ruthenium complex dye represented by the formula (1-3) (only one or a plurality of carboxyl groups (-COOH) protons (H ⁺ ) can also be dissociated); (wherein R ⁶ to R ⁹ each independently represent an alkoxy extended aryl vinyl group represented as follows (wherein, R represents an alkyl group having 1 to 12 carbon atoms, Z represents an exoaryl group having 6 to 18 carbon atoms), and s, t, u and v represent an integer of 0 to 4, but s, t, u And v is not 0 at the same time; when s, t, u or v is 2 or more, a plurality of R ⁶ , a plurality of R ⁷ , a plurality of R ⁸ and a plurality of R ⁹ may be the same or different; X represents a relative Ion, q represents the number of relative ions necessary to neutralize the charge of the complex; in addition, 2 They may be the same or different, each independently representing a chelating-type ligand capable of bidentate coordination. The dinuclear ruthenium complex dye according to claim 6 of the patent application, wherein the Z is a stretching phenyl group. The dinuclear ruthenium complex dye according to claim 7, wherein the R ⁶ to R ⁹ are a hexyloxyphenylene vinyl group. The dinuclear ruthenium complex dye according to any one of claims 6 to 8, wherein It is a bipyridine, a pyridylquinoline, a biquinoline or a morpholine which may also have a substituent. A photoelectric conversion element comprising the dinuclear ruthenium complex dye and the semiconductor fine particles according to any one of claims 1 to 9. The photoelectric conversion element according to claim 10, wherein the semiconductor fine particles are at least one selected from the group consisting of titanium oxide, zinc oxide, and tin oxide. A photochemical battery comprising: a photoelectric conversion element according to claim 10 or 11 of the patent application. A photochemical battery characterized by having a photoelectric conversion element according to claim 10 or 11 and a counter electrode as an electrode with an electrolyte layer therebetween. A method of producing a photoelectric conversion element, comprising the step of immersing semiconductor fine particles in a solution containing the dinuclear ruthenium complex dye according to any one of claims 1 to 9. A method for producing a photoelectric conversion element, comprising the steps of: forming a semiconductor layer containing semiconductor fine particles on a conductive support; and immersing the semiconductor layer in any one of items 1 to 9 of the patent application scope A solution of the dinuclear ruthenium complex pigment. A photochemical battery comprising: a semiconductor microparticle obtained by sensitizing a dinuclear ruthenium complex dye according to any one of claims 1 to 9; and an ionic liquid represented by the general formula (2) Main component electrolyte solution; (wherein Y ^- represents ethyl sulfate, 2-(2-methoxy)ethoxyethyl sulfate, or trifluoromethanesulfonate).