JP5751177B2 - Ruthenium-containing compound and method for producing the same - Google Patents

Description

  The present invention relates to ruthenium-containing compounds. More specifically, the present invention relates to a ruthenium-containing compound useful as a dye that is a constituent material of a dye-sensitized solar cell that exhibits high conversion efficiency and excellent durability such as weather resistance and heat resistance.

  In recent years, with increasing interest in energy problems, research on solar cells that can efficiently convert light, particularly sunlight, into electricity has become active. For example, silicon-based solar cells using amorphous silicon or polycrystalline silicon have begun to spread.

However, silicon solar cells have a problem of high manufacturing costs. In particular, since it is difficult to supply high-purity silicon at a low cost and in large quantities, it is said that there is a limit to the widespread use of silicon-based solar cells in general.
In recent years, therefore, dye-sensitized solar cells have attracted attention. Dye-sensitized solar cells have high power generation efficiency, relatively low manufacturing costs, inexpensive oxide semiconductors such as titanium oxide can be used as raw materials without being purified to high purity, and equipment used for manufacturing is inexpensive This has many advantages over silicon-based solar cells. Therefore, it is expected as a next-generation solar cell (Patent Documents 1 and 2).

  The dye-sensitized solar cell includes an anode, a cathode, and an electrolyte as in a normal battery. However, in the dye-sensitized solar cell, the cathode has a base material made of transparent conductive glass and an oxide thin film electrode formed on the surface of the base material. It is characterized in that it has a structure in which a dye is adsorbed.

  As dyes adsorbed on the oxide thin film electrode, dyes described in Non-Patent Documents 1 and 2 are known.

US Pat. No. 4,927,721 International Publication No. 98/50393 Pamphlet

J. et al. Am. Chem. Soc. 115, 6382-6390 (1993) J. et al. Am. Chem. Soc. , 123, 1613-1624 (2001)

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dye-sensitized solar cell that has a high light absorption rate in the visible light region and exhibits high conversion efficiency when used in a dye-sensitized solar cell. To provide a novel compound useful as a dye, which is expected to be obtained.

（式（１）中、Ｒは−ＣＦ_３、−ＣＮ、−ＯＣＨ_３及び−ＳＣＨ_３からなる群より選ばれる基である。） The above problems have been solved by the following means.
A ruthenium-containing compound represented by the following formula (1).

(In formula (1), R is a group selected from the group consisting of —CF ₃ , —CN, —OCH ₃ and —SCH ₃ ).

The ruthenium-containing compound of the present invention has a large light absorption rate in the visible light region. When this compound is used as a dye for a dye-sensitized solar cell, the dye-sensitized solar cell is expected to exhibit high conversion efficiency.
This dye is expected to exhibit an effect of exhibiting high conversion efficiency and excellent durability such as weather resistance and heat resistance.

  Hereinafter, although the form for implementing this invention is demonstrated, this invention is not limited to the following embodiment.

（式（１）中、Ｒは−ＣＦ_３、−ＣＮ、−ＯＣＨ_３、及び、−ＳＣＨ_３からなる群より選ばれる基である。） [1] Ruthenium-containing compound (ruthenium complex):
One embodiment of the ruthenium-containing compound of the present invention (hereinafter also referred to as the compound of the present invention) is represented by the formula (1). A dye containing such a compound exhibits a high conversion efficiency and is a constituent material of a dye-sensitized solar cell excellent in durability such as weather resistance and heat resistance.

(In Formula (1), R is a group selected from the group consisting of —CF ₃ , —CN, —OCH ₃ , and —SCH ₃ ).

[2] Dye-sensitized solar cell:
The pigment | dye containing the compound of this invention is used for the dye-sensitized solar cell which has a well-known structure. These dye-sensitized solar cells include an anode, a cathode, and an electrolyte. The cathode has a base material made of transparent conductive glass and an oxide thin film electrode formed on the surface of the base material. By adsorbing the dye containing the compound of the present invention to the oxide thin film electrode of such a known dye-sensitized solar cell, the dye sensitization exhibits high conversion efficiency and excellent durability such as weather resistance and heat resistance. A solar cell is obtained. Known materials can be preferably used for the anode, cathode, and electrolyte.

[3] Adsorption of dye:
As a method for adsorbing the dye containing the compound of the present invention to the oxide thin film electrode, a known method can be applied. For example, it can carry out by making the pigment | dye solution containing the pigment | dye containing the compound of this invention, and a base contact the member for cathodes which has an oxide thin film electrode.

  “Dye solution” is a dye containing the compound of the present invention, that is, a solution containing the compound represented by formula (1) and a base. The dye solution preferably contains a dye at a concentration of 0.1 to 10 mmol / L. By setting the concentration of the dye to 0.1 mmol / L or more, a sufficient amount of the dye can be adsorbed to the oxide thin film electrode. On the other hand, when the amount is 10 mmol or less, it is possible to suppress a problem that the dyes are associated with each other. In order to exhibit such an effect more reliably, the concentration of the dye is more preferably 0.2 to 5 mmol / L, and particularly preferably 0.5 to 2 mmol / L.

  The base contained in the “dye solution” may be an inorganic base or an organic base.

  Examples of the “inorganic base” include alkali metal hydroxides, alkali metal carbonates, alkali metal sulfides, alkaline earth metal hydroxides, and the like.

  Examples of the “alkali metal hydroxide” include lithium hydroxide, sodium hydroxide, potassium hydroxide and the like. Examples of the “alkali metal carbonate” include lithium carbonate, sodium carbonate, potassium carbonate and the like. Examples of the “alkali metal sulfide” include lithium sulfide, sodium sulfide, potassium sulfide and the like. Examples of the “alkaline earth metal hydroxide” include calcium hydroxide and magnesium hydroxide.

  Examples of the “organic base” include primary to tertiary amine compounds, quaternary ammonium hydroxides, quaternary ammonium carbonates, quaternary ammonium sulfides, quaternary phosphonium hydroxides, and quaternary phosphonium compounds. Examples thereof include carbonates, quaternary phosphonium sulfides, nitrogen-containing heteroaromatic compounds having a nitrogen atom in the aromatic ring, and aromatic amine compounds.

  Examples of the “primary to tertiary amine compound” include primary amines such as methylamine and ethylamine; secondary amines such as dimethylamine and diethylamine; tertiary amines such as trimethylamine and triethylamine.

  Examples of the “quaternary ammonium hydroxide” include tetraethylammonium hydroxide and tetrabutylammonium hydroxide. Examples of the “quaternary ammonium carbonate” include tetramethylammonium carbonate and tetrabutylammonium carbonate. Examples of the “quaternary ammonium sulfide” include tetramethylammonium sulfate and tetrabutylammonium sulfate.

  Examples of the “quaternary phosphonium hydroxide” include tetramethylphosphonium hydroxide and tetrabutylphosphonium hydroxide. Examples of the “quaternary phosphonium carbonate” include tetramethylphosphonium carbonate, tetrabutylphosphonium carbonate, and the like. Examples of the “quaternary phosphonium sulfide” include tetramethylphosphonium sulfate, tetrabutylphosphonium sulfate, and the like.

  Examples of the “nitrogen-containing heteroaromatic compound” include pyridine, pyrrole, lutidine and the like. Examples of the “aromatic amine compound” include aniline, methylaniline, dimethylaniline and the like.

  The base contained in the dye solution is preferably a Bronsted base. Among the above-mentioned bases, it is more preferable to use an organic base, and it is more preferable to use a quaternary ammonium hydroxide or a quaternary ammonium carbonate, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, tetramethylammonium. Most preferably, carbonate and tetrabutylammonium carbonate are used. Among the most preferable ones, tetraethylammonium hydroxide and tetrabutylammonium hydroxide are preferable.

  The dye solution preferably contains the above base at a concentration of 0.0001 to 50 mN, more preferably contains 0.001 to 20 mN, and particularly preferably contains 0.01 to 10 mN. .

  As a solvent for the dye solution, for example, water, a polar organic solvent, or a mixed solvent thereof is preferably used. Examples of the polar organic solvent include ether, alcohol, nitrile, amide, sulfoxide and the like.

  Examples of the “ether” include diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether and the like. Examples of the “alcohol” include ethanol, methanol, isopropyl alcohol, butanol and the like. Examples of “nitrile” include acetonitrile, benzonitrile, propiononitrile, and the like. Examples of “amide” include dimethylformamide, dimethylacetamide and the like. Examples of the “sulfoxide” include dimethyl sulfoxide.

  Among these solvents, alcohol, nitrile, or amide is preferably used, and ethanol, methanol, butanol, or acetonitrile is more preferably used. Moreover, as a mixed solvent of a solvent, it is preferable to use the mixed solvent of alcohol and nitrile, and it is still more preferable to use the mixed solvent of butanol and acetonitrile.

  The method for bringing the cathode member into contact with the dye solution is not particularly limited, and examples thereof include a method of immersing the cathode member in the dye solution.

  When the cathode member is immersed in the dye solution, the immersion time is preferably 0.5 to 100 hours, more preferably 2 to 50 hours, and particularly preferably 12 to 24 hours. Moreover, it is preferable that the temperature in the case of immersion shall be 0-100 degreeC, and it is still more preferable that temperature shall be 10-50 degreeC.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. A method for measuring various physical properties and a method for evaluating various properties are shown below.

Example 1
Synthesis of cis-Dichroro-bis (4,4′-dicarboxy-2,2′-bipyridine) Ruthenium (cis-dichloro-bis (4,4′-dicarboxy-2,2′-bipyridine) ruthenium) Dimroth condenser Into a 500 mL three-necked flask equipped with 2,2′-Bipyridine-4,4′-dicarboxylic Acid 5.0 g (20.5 mmol), Dichroro (p-cymene) -ruthenium (II) dimer 3.14 g (5.1 mmol) ), Dimethylformamide (240 mL) was added, and the mixture was stirred at 170 ° C. for 1.5 hours under a nitrogen atmosphere. After the reaction vessel was air-cooled, the reaction solution was filtered. The filtrate was concentrated under reduced pressure at 90 ° C. to obtain a target crude product. Next, 200 mL of acetone was added to the crude product. The components deposited by this work were collected by suction filtration. Further, the crystals were washed with acetone and then vacuum-dried to obtain 6.61 g (yield 98) of cis-Dichloro-bis (4,4′-dicboxy-2,2′-bipyridine) Ruthenium represented by the following chemical formula. %).
The present compound, ^{1 H-NMR} measurement of this compound performs IR measurement confirmed that the compound of interest is obtained. The analysis results were as follows.

¹ H-NMR (solvent: d6-DMSO) chemical shift σ: 10.08 ppm (hydrogen on pyridine ring, 2H), 9.03 ppm (hydrogen on pyridine ring, 2H), 8.86 ppm (hydrogen on pyridine ring, 2H) 8.21 ppm (hydrogen on pyridine ring, 2H), 7.73 ppm (hydrogen on pyridine ring, 2H), 7.47 ppm (hydrogen on pyridine ring, 2H)

(Example 2)
Bis (4,4′-dicboxy-2,2′-bipyridine) 2- (4-trifluoromethyl) pyridine Ruthenium (II) (bis (4,4′-dicarboxy-2,2′-bipyridine) 2- (4 Synthesis of -trifluoromethylphenyl) pyridine ruthenium (II)) In a 500 mL three-necked flask, cis-Dichloro-bis (4,4'-dicboxy-2,2'-bipyridine) Ruthenium 1.32 g (2.00 mmol), 2- 0.92-g (4.1 mmol) of [4- (Trifluoromethyl) phenyl] pyridine was weighed out. Ethylene glycol (250 mL) was added, and the mixture was stirred at 170 ° C. for 1.5 hours under a nitrogen atmosphere. After cooling the reaction solution to room temperature, 8.8 mL of 37% tetrabutylammonium hydroxide-methanol solution was added to the reaction solution, and the mixture was stirred at 170 ° C. for 7 hours under a nitrogen atmosphere. The reaction vessel was air-cooled and the reaction solution was filtered. The obtained filtrate was concentrated under reduced pressure at 90 ° C. and 2 mmHg, and the solvent was distilled off. Distilled water (100 mL) was added to the residue after evaporation of the solvent and stirred, and then 0.5N nitric acid aqueous solution was added to adjust the pH to 1.8. This solution was allowed to stand at room temperature for 12 hours, and the precipitated crystals were collected by suction filtration. The obtained crystals were washed with distilled water and ethyl acetate and dried in vacuo to obtain 1.11 g of crude crystals. The crude crystals were then purified on a Sephadex (registered trademark) column. Specifically, first, components that flowed out were removed using distilled water as an eluent, and then the components that flowed out were collected using a 1N aqueous sodium hydroxide solution as an eluent. This component was distilled off under reduced pressure to remove the solvent, and the residue was dissolved in 60 mL of distilled water. A 0.5N aqueous nitric acid solution was added to the dissolved residue to adjust pH = 1.8. This solution was allowed to stand at room temperature for 12 hours, and the precipitated crystals were collected by suction filtration. The crystal was washed with distilled water and vacuum dried to obtain 0.51 g of the target compound crystal represented by the following chemical formula.

This compound was subjected to ¹ H-NMR measurement, ¹⁹ F-NMR measurement, IR measurement, and LC-MS to confirm that the target compound was obtained. The analysis results were as follows.

¹ H-NMR (solvent: d4-MeOH-MeONa) chemical shift σ: 9.02 ppm (hydrogen on aromatic ring, 1H), 8.95 ppm (hydrogen on aromatic ring, 1H), 8.92 ppm (hydrogen on aromatic ring, 1H), 8.89 ppm (hydrogen on aromatic ring, 1H), 8.19 ppm (hydrogen on aromatic ring, 1H), 8.04 ppm (hydrogen on aromatic ring, 1H), 8.00 ppm (hydrogen on aromatic ring, 1H) 7.86 ppm (hydrogen on aromatic ring, 2H), 7.78 ppm (hydrogen on aromatic ring, 3H), 7.71 ppm (hydrogen on aromatic ring, 1H), 7.67 ppm (hydrogen on aromatic ring, 1H), 7 .63 ppm (hydrogen on aromatic ring, 2H), 7.13 ppm (hydrogen on aromatic ring, 1H), 7.05 ppm (hydrogen on aromatic ring, 1H), 6.66 ppm (hydrogen on aromatic ring, 1H)

¹⁹ F-NMR (solvent: d4-MeOH-MeONa) chemical shift σ: -64.3 ppm

IR (KBr ^{tablet): 3090cm -1, 2879cm -1,} 2821cm -1, 1941cm -1, 1716cm -1, 1604cm -1, 1540cm -1, 1471cm -1, 1405cm -1, 1375cm -1, 1317cm -1, 1255 cm ⁻¹ , 1230 cm ⁻¹ , 1159 cm ⁻¹ , 1116 cm ⁻¹ , 1072 cm ⁻¹ , 1006 cm ⁻¹ , 894 cm ⁻¹ , 769 cm ⁻¹ , 682 cm ⁻¹ .

(Example 3)
Bis (4,4′-dicboxy-2,2′-bipyridine) 2- (4-trifluoromethyl) pyridine Ruthenium (II) (bis (4,4′-dicarboxy-2,2′-bipyridine) 2- (4 Preparation of TBA (tetrabutylammonium) salt of -trifluoromethylphenyl) pyridine ruthenium (II)) Bis (4,4′-dicboxy-2,2′-bipyridine) synthesized in Example 2 2- (4-trifluoromethylphenyl) ) Pyridine (240 mg (0.30 mmol)), 50 mL of methanol was added, and 3.8 mL (1.50 mol) of a 10% tetrabutylammonium hydroxide-methanol solution was further added to obtain a homogeneous solution. 0.5N nitric acid aqueous solution was added to this solution to adjust the pH to 3.8, and the solution was stored at 5 ° C. for 12 hours. The precipitated crystals were collected by suction filtration, and the crystals were washed with distilled water and diethyl ether. The crystal after washing was vacuum-dried to obtain 236 mg of crystal.

This compound (crystal) was subjected to ¹ H-NMR measurement and ¹⁹ F-NMR measurement of this compound to confirm that the target compound was obtained. The analysis results were as follows.

¹ H-NMR (solvent: d4-MeOH-MeONa) chemical shift σ: 9.07 ppm (hydrogen on aromatic ring, 1H), 8.99 ppm (hydrogen on aromatic ring, 1H), 8.96 ppm (hydrogen on aromatic ring, 1H), 8.94 ppm (hydrogen on aromatic ring, 1H), 8.21 ppm (hydrogen on aromatic ring, 1H), 8.10 ppm (hydrogen on aromatic ring, 1H), 8.02 ppm (hydrogen on aromatic ring, 1H) 7.96-7.90 ppm (hydrogen on aromatic ring, 4H), 7.81 ppm (hydrogen on aromatic ring, 1H), 7.78 ppm (hydrogen on aromatic ring, 1H), 7.73 ppm (hydrogen on aromatic ring, 1H), 7.69 ppm (hydrogen on the aromatic ring, 1H), 7.60 ppm (hydrogen on the aromatic ring, 1H), 7.14 ppm (hydrogen on the aromatic ring, 1H), 7.08 ppm (hydrogen on the aromatic ring, 1H) 6.62 ppm (on aromatic ring _{Hydrogen, 1H), 3.23ppm (N- CH} 2 -CH 2 -CH 2 -CH 3, 8H), 1.67ppm (N-CH 2 - CH 2 -CH 2 -CH 3, 8H), 1.42ppm _{(N-CH 2 -CH 2 -} CH 2 -CH 3, 8H), 1.02ppm (N-CH 2 -CH 2 -CH 2 - CH 3, 12H)

¹⁹ F-NMR (solvent: d4-MeOH-MeONa) chemical shift σ: −64.5 ppm

  The compound of this invention can be used suitably as a pigment | dye of a dye-sensitized solar cell.

Claims (1)

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

(In formula (1), R is a group selected from the group consisting of —CF ₃ , —CN, —OCH ₃ and —SCH ₃ ).