CN101503427B - Ruthenium metal complex - Google Patents

Abstract

The invention relates to a ruthenium metal complex, which has the following structure as shown in formula : RuLL' X₂(I) Wherein L, L' and X are defined as the specification. The ruthenium metal complex of the present invention can be applied to Dye-Sensitized Solar cells (DSSCs) and has excellent photoelectric properties.

Description

Ruthenium metal complex

technical field

The invention relates to a ruthenium metal complex, in particular to a ruthenium metal complex suitable for dye-sensitized solar cells (Dye-Sensitized Solar Cell, DSSC).

Background technique

With the development of human civilization, the world is facing serious energy crisis and environmental pollution. Using photoelectric solar cells to directly convert solar energy into electrical energy is one of the important methods to solve the world's energy crisis and reduce environmental pollution; among them, dye sensitization Solar cells have become a promising new type of solar cells due to their low manufacturing cost, large area, flexibility, and light transmission, which can be used in buildings.

tzel等人发表一系列染料敏化太阳能电池相关文献(例如O’Regan，B.；Gr

tzel，M.Nature 1991，353，737)，显示染料敏化太阳能电池具有实用性。一般而言，染料敏化太阳能电池的结构包括有阴/阳电极、纳米二氧化钛、染料及电解质；染料敏化太阳能电池中的染料对电池效率有关键性的影响，理想的染料要具有可以吸收较大范围的太阳光谱、高摩尔吸收系数(absorption coefficient)、高温安定性及光安定性等。In recent years, Gr

tzel et al published a series of literatures related to dye-sensitized solar cells (such as O'Regan, B.; Gr

tzel, M. Nature 1991, 353, 737), showing the utility of dye-sensitized solar cells. Generally speaking, the structure of dye-sensitized solar cells includes negative/anode electrodes, nano-titanium dioxide, dyes, and electrolytes; dyes in dye-sensitized solar cells have a key impact on cell efficiency, and ideal dyes should have the ability to absorb more Wide range of solar spectrum, high molar absorption coefficient (absorption coefficient), high temperature stability and light stability, etc.

Gr The tzel lab has published a series of ruthenium complexes as dyes in dye-sensitized solar cells. 1993Gr The tzel laboratory published a dye-sensitized solar cell prepared by using N3 dye, and its efficiency reached 10.0% (AM 1.5). The single-wavelength photoelectric conversion efficiency (IPCE) value of N3 dyes can reach 80% in the range of 400nm-600nm, and hundreds of dye complexes developed later cannot surpass N3 dyes in performance tests. The structure of N3 dye is shown in formula (a) below.

tzel实验室发表使用N719染料所制备的染料敏化太阳能电池，其效率提升到10.85％(AM 1.5)。N719染料的结构如下式(b)所示。Until 2003 Gr

The tzel laboratory published a dye-sensitized solar cell prepared by using N719 dye, and its efficiency was increased to 10.85% (AM 1.5). The structure of N719 dye is shown in formula (b) below.

Then in 2004, the same laboratory published a dye-sensitized solar cell prepared with black dye, and its efficiency reached 11.04% (AM 1.5). The black dye can enhance the spectral response in the red and infrared regions, thereby enhancing the performance of the dye-sensitized cell. The structure of the black dye is shown in the following formula (c).

tzel实验室发表的N3染料、N719染料与黑染料等相关系列的钌络合物之外，其它类似的有铂络合物、锇络合物、铁络合物、铜络合物...等等。但是经过许多研究显示钌络合物的效率仍为较佳。Except Gr

In addition to the related series of ruthenium complexes such as N3 dyes, N719 dyes and black dyes published by the tzel laboratory, other similar ones include platinum complexes, osmium complexes, iron complexes, copper complexes... etc. However, many studies have shown that the efficiency of the ruthenium complex is still better.

The dyes in dye-sensitized solar cells have a critical impact on cell efficiency. Therefore, finding dye molecules that can improve the efficiency of dye-sensitized solar cells is one of the important methods to improve the efficiency of dye-sensitized solar cells.

Contents of the invention

The object of the present invention is to provide a ruthenium metal complex, which is suitable for dye-sensitized solar cells.

For realizing the above object, the ruthenium metal complex compound provided by the invention has the following formula (I):

RuLL'X ₂

(I)

in

X is -NCS, -SCN, -SeCN, -CN or -Cl;

L is

L' is

in

Y is -O-, -S-, -SO ₂ -, -CF ₂ -, -CCl ₂ - or -C(R ₁ ) ₂ -, wherein R ₁ is an aliphatic group or an aromatic group;

Q ₁ and Q ₂ are each independently halogen, H, -CN, -SCN, -NCS or -SF ₅ ;

B is H or -(ZA) _m -R ₂ , where Z is a single bond, -CF ₂ O-, -OCF ₂ -, -CH ₂ CH ₂ -, -CF ₂ CF ₂ -, -CF ₂ CH ₂ - , -CH ₂ CF ₂ -, -CHF-CHF-, -C(O)O-, -OC(O)-, -CH ₂ O-, -OCH ₂ -, -CF=CH-, -CH=CF -, -CF=CF-, -CH=CH- or -C≡C-; A is substituted or unsubstituted 1,4-phenylene (1,4-phenylene), where =CH- can 1 or 2 are substituted by =N-; R ₂ is H or an organic group with 1 to 15 carbon atoms; m is 0, 1 or 2.

The ruthenium metal complex, wherein X is -NCS.

The ruthenium metal complex, wherein Y is -C(R ₁ ) ₂ -, and R ₁ is an aliphatic group or an aromatic group.

The ruthenium metal complex, wherein Q ₁ and Q ₂ are independently halogen, H or -CN.

The ruthenium metal complex, wherein, m is 0.

The ruthenium metal complex, wherein Y is -C(R ₁ ) ₂ -, and R ₁ is an aliphatic group or an aromatic group.

The ruthenium metal complex, wherein Q ₁ and Q ₂ are independently halogen, H or -CN.

Described ruthenium metal complex, wherein, m is 0, R ₂ is H, alkyl (alkyl group) or alkoxyl (alkoxy).

The ruthenium metal complex provided by the invention has the following structure (I-1) or the following formula (I-2),

Description of drawings

Fig. 1 is the UV-Vis. absorption spectrogram of the embodiment of the present invention and the comparative example.

Fig. 2 is the electric current-voltage curve (I-V curve) figure of the embodiment of the present invention and comparative example.

FIG. 3 is a single-wave photoelectric-to-current conversion efficiency (IPCE) diagram of an embodiment of the present invention and a comparative example.

Detailed ways

Ruthenium metal complex of the present invention, its structure is as follows formula (I):

RuLL'X ₂

(I)

in

X is -NCS, -SCN, -SeCN, -CN or -Cl;

L is

L' is

in

Y is -O-, -S-, -SO ₂ -, -CF ₂ -, -CCl ₂ - or -C(R ₁ ) ₂ -, wherein R ₁ is aliphaticradical or aromatic radical ;

Q ₁ and Q ₂ are each independently halogen (halogen), H, -CN, -SCN, -NCS or -SF ₅ ;

B is H or -(ZA) _m -R ₂ , where Z is a single bond, -CF ₂ O-, -OCF ₂ -, -CH ₂ CH ₂ -, -CF ₂ CF ₂ -, -CF ₂ CH ₂ - , -CH ₂ CF ₂ -, -CHF-CHF-, -C(O)O-, -OC(O)-, -CH ₂ O-, -OCH ₂ -, -CF=CH-, -CH=CF -, -CF=CF-, -CH=CH- or -C≡C-, A is substituted or unsubstituted 1,4-phenylene (1,4-phenylene), where =CH- can 1 or 2 are replaced by =N-; R ₂ is H, hydroxyl (hydroxyl) or an organic group with 1 to 15 carbon atoms; m is 0, 1 or 2.

X in the above formula (I) can be -NCS, -SCN, -SeCN, -CN or -Cl, preferably -NCS, -SCN, or -CN, more preferably -NCS or -SCN.

Y in the above formula (I) can be -O-, -S-, -SO ₂ -, -CF ₂ -, -CCl ₂ -, -C(R ₁ ) ₂ -, wherein R ₁ is aliphatic or aromatic group; preferably -O-, -S-, -CF ₂ -, -CCl ₂ -, -C(R ₁ ) ₂ -, wherein R ₁ is an aliphatic or aromatic group; more preferably -CF ₂ -, -CCl ₂ -, -C(R ₁ ) ₂ -, wherein R ₁ is an aliphatic group or an aromatic group; the most preferred is -C(R ₁ ) ₂ -, wherein R ₁ is an aliphatic group or an aromatic group.

The above-mentioned R ₁ can be an aliphatic group or an aromatic group, preferably an alkyl group or an alkoxy group.

Q ₁ and Q ₂ in the above formula (I) can each independently be halogen, H, -CN, -SCN, -NCS or -SF ₅ , preferably halogen, H or -CN, more preferably Halogen or H.

B in the above formula (I) can be H or -(ZA) _m -R ₂ , wherein Z is a single bond, -CF ₂ O-, -OCF ₂ -, -CH ₂ CH ₂ -, -CF ₂ CF ₂ -, -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -CHF-CHF-, -C(O)O-, -OC(O)-, -CH ₂ O-, -OCH ₂ -, -CF =CH-, -CH=CF-, -CF=CF-, -CH=CH- or -C≡C-, A is a substituted or unsubstituted 1,4-phenylene group, where =CH- One or two can be replaced by =N-, _R2 is H, hydroxyl or an organic group with 1 to 15 carbon atoms, m is 0, 1 or 2; preferably H.

The aforementioned Z may be a single bond, -CF ₂ O-, -OCF ₂ -, -CH ₂ CH ₂ -, -CF ₂ CF ₂ -, -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -CHF-CHF -, -C(O)O-, -OC(O)-, -CH ₂ O-, -OCH ₂ -, -CF=CH-, -CH=CF-, -CF=CF-, -CH=CH -or -C≡C-, preferably a single bond, -CH ₂ CH ₂ -, -C(O)O-, -OC(O)-, -CH ₂ O-, -OCH ₂ -, -CH =CH- or -C≡C-, more preferably a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -OCH ₂ -, -CH=CH- or -C≡C-, most preferably is a single bond, -CH ₂ CH ₂ - or -CH═CH-.

The above-mentioned A can be a 1,4-phenylene group with 1 to 4 substituents or no substituents, wherein =CH- can be substituted by =N- one or two times; preferably there are 1 to 4 substitutions or unsubstituted 1,4-phenylene, whose substituents are selected from hydroxyl, halogen, alkyl, alkoxy, alkenyl (alkenyl), or -CN, more preferably 1 to 4 substitutions or 1,4-phenylene without substituent, whose substituent is selected from halogen, alkyl, alkoxy or -CN.

_The above R can be H, hydroxyl or an organic group with 1 to 15 carbon atoms, preferably H, alkyl, alkoxy, alkenyl or -CN, more preferably H, alkyl, alkane Oxygen, or -CN.

The above m can be 0, 1 or 2, preferably 0 or 1.

The ruthenium metal complex concrete example of above-mentioned formula (I) has:

In the present invention, the compound molecule is expressed in the form of free acid, but its actual form may be salts, alkali metal salts or quaternary ammonium salts.

The ruthenium metal complex of the present invention can be synthesized in the manner of scheme 1.

Process 1: (Toluene is toluene, DMF is dimethylformamide)

(II-1): R=C ₂ H ₅

(II-2): R=C ₆ H ₁₃

(I-1): R=C ₂ H ₅

(I-2): R=C ₆ H ₁₃

First, 9,9-diethyl-9-hydrogen-fluoren-2-ylboronic acid (9,9-diethyl-9H-fluoren-2-ylboronic acid) and 4,4'-dibromo-2,2' -bipyridine (4,4'-dibromo-2,2'-bipyridine) is by Suzuki coupling reaction with tetrakis (triphenylphosphine) palladium (tetrakis(triphenylphosphine) palladium) as catalyzer, reaction produces formula (II-1) Ligand.

Then, [RuCl ₂ (p-cymene)] ₂ and the ligand of (II-1) were dissolved in dehydrated dimethyl formamide, and the solution was heated to 80°C under nitrogen After reacting for 4 hours, add 4,4'-dicarboxylic acid-2,2'-bipyridine (4,4'-dicarboxylic acid-2,2'-bipyridine, H ₂ dcbpy) and heat to 160°C for reaction 4 hours, the above chemical reaction must be carried out in the dark, to avoid the isomerization reaction caused by light to produce isomers. Next, excess ammonium thiocyanate (NH ₄ NCS) was added, and the reaction temperature was controlled at 130° C. for 5 hours to obtain the ruthenium metal complex of formula (I-1).

The following examples illustrate the present invention, and the scope of the claims of the present invention is not limited thereby. The compound molecule is expressed in the form of free acid, but its actual form may be a salt, more likely an alkali metal salt or a quaternary ammonium salt. Unless otherwise specified, temperatures are in degrees Celsius, and parts and percentages are by weight. The relationship between parts by weight and parts by volume is like the relationship between kilograms and liters.

Example 1

synthetic ligand

1.00 parts of 9,9-diethyl-9-hydrogen-fluoren-2-ylboronic acid (9,9-diethyl-9H-fluoren-2-ylboronic acid), 0.42 parts of 4,4'-dibromo-2, 2'-bispyridine (4,4'-dibromo-2,2'-bipyridine) and 0.09 parts of tetrakis (triphenylphosphine) palladium (tetrakis(triphenylphosphine) palladium) were added to 50 parts of toluene and stirred to mix. 5.64 parts of 2M sodium carbonate (sodium carbonate) aqueous solution were added into the syringe, and the reaction mixture was heated to 100° C. for 12 hours. The product was extracted with dichloromethane (dichloromethane), then washed with water and then dehydrated with magnesium sulfate (magnesium sulfate). After purification, the ligand of formula (II-1) of the present invention is obtained.

Example 2

Synthesis of ruthenium metal complexes

Dissolve 0.10 parts of [RuCl ₂ (p-cymene)] 2 and 0.20 parts of (II-1) ligand in 30 ml of dehydrated dimethyl formamide (dimethyl formamide), and place the solution under nitrogen After heating to 80°C for 4 hours, add 0.08 parts of 4,4'-dicarboxylic acid-2,2'-bipyridine (4,4'-dicarboxylic acid-2,2'-bipyridine, H ₂ dcbpy), And heated to 160 ° C for 4 hours, the above chemical reaction must be carried out in the dark, to avoid the isomerization reaction caused by light to produce isomers. Next, 0.98 parts of ammonium thiocyanate (NH ₄ NCS) was added, and the reaction temperature was controlled at 130° C. for 5 hours. After the reaction was finished, evaporate the solvent with a rotary evaporator (rotary-evaporator), then add a large amount of water to dissolve excess ammonium thiocyanate, then filter and collect the water-insoluble product with a sintered glass filter (sintered glass filter), and Wash the product with distilled water and diethyl ether, respectively, to obtain the crude product. After the crude product was dissolved in methanol, it was separated and purified by Sephadex LH-20 column eluting with methanol, collecting the eluate of the main component, and concentrating the eluate, then adding a few drops of 0.01M nitric acid aqueous solution , the ruthenium metal complex of formula (I-1) of the present invention can be precipitated.

Example 3

synthetic ligand

1.42 parts of 9,9-dihexyl-9-hydrogen-fluoren-2-ylboronic acid (9,9-dihexyl-9H-fluoren-2-ylboronic acid), 0.42 parts of 4,4'-dibromo-2,2 '-Bipyridine and 0.09 parts of tetrakis(triphenylphosphine)palladium were added to 50 parts of toluene and stirred, and 5.64 parts of 2M aqueous sodium carbonate solution was added by syringe, and the reaction mixture was heated to 100°C for 12 hours. This product is extracted with dichloromethane, then washed with water and then dehydrated with magnesium sulfate, and the residue after the solvent is extracted is purified by silica gel column with dichloromethane/methanol eluting chromatography to obtain the product of formula (II-2) of the present invention. Ligand.

Example 4

Synthesis of ruthenium metal complexes

Dissolve 0.10 parts of [RuCl ₂ (p-cymene)] ₂ and 0.28 parts of (II-2) ligand in 30 ml of dehydrated dimethylformamide, and heat the solution to 80°C under nitrogen After reacting for 4 hours, add 0.08 parts of 4,4'-diformyl-2,2'-bipyridine, and heat to 160°C for 4 hours. The above chemical reaction must be carried out in a dark place to avoid exposure to light. The isomerization reaction produces isomers. Next, 0.98 parts of ammonium thiocyanate was added, and the reaction temperature was controlled at 130° C. for 5 hours. After the reaction is over, use a rotary evaporator to remove the solvent, then add a large amount of water to dissolve the excess ammonium thiocyanate, then filter and collect the water-insoluble product with a sintered glass filter, and wash the product with distilled water and ether respectively. The crude product was obtained. After the crude product is dissolved in methanol, use Sephadex LH-20 column to elute with methanol to separate and purify, collect the eluate of the main component, and concentrate the eluate, then add a few drops of 0.01M nitric acid aqueous solution to precipitate Ruthenium metal complexes of formula (I-2) according to the present invention.

Test Method and Results

UV-Vis spectrum

The ruthenium metal complex dye and the N719 dye of the present invention were prepared with dimethylformamide as a solvent to prepare a dye solution with a concentration of 1.75×10 ^-5 M, and measured its UV-Vis spectrum.

Fabrication and testing of dye-sensitized solar cells

First soak the electrode prepared with anatase (TiO ₂ ) nano crystal particles in the solution containing the ruthenium metal complex dye of the present invention for a certain period of time, so that the ruthenium metal complex dye is adsorbed on the anatase nano crystal of the electrode Then take out the anatase nanocrystal particle electrode, rinse with solvent slightly and dry, cover and seal the counter electrode. After that, the electrolyte solution (0.05M I ₂ /0.5M LiI/0.5M tertiary butylpyridine in acetonitrile solution) was injected, and the injection port was sealed to complete the dye-sensitized solar cell with an effective area of 0.25 cm2. The resulting dye-sensitized solar cell was tested for its open circuit voltage (V _OC ), short circuit current (J _SC ), photoelectric conversion efficiency (η), fill factor (FF) and single-wave photoelectric current conversion efficiency under the illumination of AM1.5 (Incident Photon to Current Conversion Efficiency, IPCE).

Likewise, a dye-sensitized solar cell with N719 dye was fabricated and tested in the same manner as above.

The test results are summarized in Table 1 below:

Table 1. Test results of dyes and dye-sensitized solar cells

dye Molar absorption coefficient of the longest wavelength absorption peak (M ^-1 cm ^-1 ) V _OC (V) J _SC (mA/cm ² ) η(%) FF Example 2 I-1 14007 0.67 -16.56 7.20 0.65 comparative example N719 12617 0.69 -16.39 7.12 0.63

The test results shown in Table 1 show that the molar absorption coefficient of the longest wavelength absorption peak of the ruthenium metal complex of Example 2 of the present invention is higher than that of N719 of the comparative example, indicating that a relatively small amount of the ruthenium metal complex of the embodiment of the present invention is used , you can get the same photoelectric conversion efficiency as N719.

See Figure 1. Fig. 1 is the UV-Vis. absorption spectrogram of embodiment and comparative example, can find out by UV-Vis. The N719 of the example is high, which means that the same effect as that of N719 can be obtained by using a relatively small amount of the ruthenium metal complex of the example of the present invention at all wavelengths.

See Figure 2. Fig. 2 is the current-voltage curve (I-V curve) figure of embodiment and comparative example, as can be seen from the current-voltage curve figure, with the dye sensitization that the I-1 ruthenium metal complex of the embodiment of the present invention 2 is made Compared with the dye-sensitized solar cell made of N719 in the comparative example, the photoelectric characteristics of the solar cell are equivalent.

See Figure 3. Fig. 3 is the single-wave photoelectric current conversion efficiency (IPCE) figure of embodiment and comparative example, as can be seen from the single-wave photoelectric current conversion efficiency figure, the I-1 ruthenium metal complex of the embodiment of the present invention 2 is made In the dye-sensitized solar cell, compared with the dye-sensitized solar cell made of N719 in the comparative example, the photocurrent conversion efficiency of the ruthenium metal complex of the present invention is higher than that of N719 at long wavelengths.

It should be noted that the above-mentioned embodiments are illustrated for convenience of description only, but are not intended to limit the present invention. Those skilled in the art may make some changes without departing from the spirit and scope of the present invention. Therefore, the scope of rights claimed by the present invention should be based on the scope of claims of the application, rather than limited to the above-mentioned embodiments.

Claims (1)

1. a ruthenium metal complex, its structure is as follows formula (I-1) or following formula (I-2),

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