KR20080103683A - Novel Julolidine-Based Dye and Method for Preparing the Same - Google Patents

Abstract

The present invention relates to a novel julolidine-based dye and a method for preparing the same. The present invention has a gluolidine as an electron donor, a bithiophene unit at an intermediate linking portion, and a cyanoacrylic acid as an electron acceptor. Dye compounds are used in dye-sensitized solar cells (DSSCs) to show improved molar absorption coefficient, J _sc (short circuit photocurrent density) and photoelectric conversion efficiency than conventional dyes, which greatly improves solar cell efficiency. It is possible to purify without using an expensive column, thereby significantly lowering the cost of dye synthesis.

Description

Novel JULolidine-based dyes and preparation method thereof {NOVEL JULOLIDINE-BASED DYE AND PREPARATION THEREOF}

1 is an absorption and emission spectrum in ethanol of each of the dye compounds 1a to 1c of the present invention, and an absorption spectrum when supported on a TiO ₂ layer,

(A), (b) and (c) of FIG. 2 are schematic diagrams showing the optimized structures (calculated by TD-DFT for B3LYP / 3-21G) of each of the dye compounds 1a to 1c of the present invention, respectively.

(A) and (b) of FIG. 3 are schematic diagrams showing the geometry (calculated by TD-DFT for HOMO and LUMO molecular orbitals, B3LYP / 3-21G) of the dye compounds 1a and 1c of the present invention, respectively,

4 is an incident photon-to-current conversion efficiency (IPCE) spectrum of a solar cell manufactured using each of the dye compounds 1a to 1c of the present invention.

5 is a photocurrent voltage curve (under AM 1.5 radiation) of a solar cell manufactured using each of the dye compounds 1a to 1c of the present invention.

The present invention relates to a novel julolidine-based dye containing a bithiophene derivative used in dye-sensitized solar cells (DSSC) and a method for producing the same.

Since the development of the dye-sensitized nanoparticle titanium oxide solar cell by the team of Michael Gratzel of the Swiss National Lausanne Institute of Advanced Technology (EPFL) in 1991, much work has been done in this area. Dye-sensitized solar cells have the potential to replace conventional amorphous silicon solar cells because of their higher efficiency and lower manufacturing costs than conventional silicon-based solar cells. It is a photoelectrochemical solar cell whose main constituent material is a dye molecule capable of absorbing and generating electron-hole pairs, and a transition metal oxide for transferring generated electrons.

As a dye used in dye-sensitized solar cells, ruthenium metal complexes having high photovoltaic conversion efficiency have been widely used, but this ruthenium metal complex has a disadvantage of being too expensive.

Recently, metal-free organic dyes, which exhibit excellent physical properties in terms of light absorption efficiency, redox reaction stability, and intramolecular charge-transfer (CT) absorption, can replace expensive ruthenium metal complexes. It has been found that it can be used as a dye for solar cells, and research on organic dyes lacking metals has been focused.

Organic dyes generally have a structure of electron donor-electron acceptor residues linked by π-binding units. In most organic dyes, amine derivatives act as electron donors, 2-cyanoacrylic acid or rhodanine residues act as electron acceptors, and these two sites are π-binding systems such as metaine units or thiophene chains. Is connected by.

In general, the structural change of the amine unit, which is an electron donor, results in a change in the electronic properties, for example, an absorption spectrum shifted toward blue, and by changing the π-bond length, the absorption spectrum and redox potential. Can be adjusted.

However, most of the organic dyes known so far have lower conversion efficiency and lower driving stability than ruthenium metal complex dyes. Thus, by changing the type or the π-bond length of these electron donors and acceptors, Efforts have been made to develop new dyes having an improved molar absorption coefficient and showing high photoelectric conversion efficiency.

Accordingly, an object of the present invention is to provide an organic dye and a method for manufacturing the same, which can improve the efficiency of a solar cell by exhibiting an improved molar absorption coefficient and photoelectric conversion efficiency than conventional metal complex dyes.

In addition, the present invention exhibits a markedly improved photoelectric conversion efficiency including the dye, a dye-sensitized photoelectric conversion device excellent in J _sc (short circuit photocurrent density) and a molar absorption coefficient, and the solar efficiency is significantly improved It is an object to provide a battery.

In order to achieve the above object, the present invention provides a gluolidine-based dye represented by the following formula (1).

Where

R ₁ and R ₂ are each independently hydrogen, C _1-12 alkyl or C _1-12 alkoxy, where C _1-12 alkoxy may combine with each other to form an oxygen-containing heterocycle;

n is an integer from 2 to 5, optionally two or more thiophene units may be linked to a vinyl group.

In addition, the present invention

(1) by reacting bromozuloridine with the compound of the formula (2) and Suzuki coupling to prepare a compound of the formula (3),

(2) preparing a compound of formula 4 by lithiation of the compound of formula 3 with n-butyllithium and then cooling with dimethylformamide successively;

(3) reacting a compound of formula 4 with cyanoacetic acid in the presence of piperidine in CH ₃ CN

It provides a method for producing a dye represented by the formula (1).

Wherein R ₁ , R ₂ and n are as defined above.

In another aspect, the present invention provides a dye-sensitized photoelectric conversion device comprising an oxide semiconductor fine particle carrying a compound represented by the formula (1).

In another aspect, the present invention provides a dye-sensitized solar cell comprising the dye-sensitized photoelectric conversion device.

Hereinafter, the present invention will be described in detail.

The present inventors use gluolidine as an electron donor, introduce a bithiophene unit to increase the molar extinction coefficient and increase the stability of the device at the intermediate connection portion, and is well connected to the TiO ₂ modification to improve the electron transport ability. When manufacturing dye-sensitized solar cell by supporting the compound represented by the formula (1) having the new organic dye structure with the best cyanoacrylic acid as the electron acceptor on the oxide semiconductor fine particles, photoelectric conversion efficiency, Jsc (short circuit photocurrent density) And it has been confirmed that the molar absorption coefficient is higher than the conventional dye-sensitized solar cell and completed the present invention.

The gluolidine organic dye of the present invention is characterized by represented by the following general formula (1), preferably has a structure of the general formula (1a) to (1c).

[Formula 1]

Wherein R ₁ , R ₂ and n are as defined above.

In another aspect, the present invention provides a method for producing a dye represented by the formula (1), the dye represented by the formula (1) (1) bromozulolidine to the compound of formula (2) and Suzuki (Suzuki) coupling Reaction to prepare a compound of formula (3), (2) Lithium-substituted reaction of the compound of formula 3 with n-butyllithium (1.2 equivalents) and then continuously cooled to dimethylformamide (DMF) to the compound of formula And (3) a compound of formula 4 can be prepared by reacting with cyanoacetic acid in the presence of piperidine in CH ₃ CN (see Scheme 1 below).

[Formula 2]

[Formula 3]

[Formula 4]

Wherein R ₁ , R ₂ and n are as defined above.

In the above scheme, bromozulolidine used as starting material for the preparation of the dye of formula 1 can be obtained by bromination of juliolidine with NBS in CHCl ₃ .

In addition, the present invention provides a dye-sensitized photoelectric conversion device, the dye-sensitized photoelectric conversion device is characterized in that the dye represented by the formula (1) on the oxide semiconductor fine particles. The present invention is a dye-sensitized photoelectric conversion device in addition to using the dye represented by the formula (1) can be applied to the method of manufacturing a dye-sensitized photoelectric conversion device for solar cells using a conventional dye, of course, preferably the present invention The dye-sensitized photoelectric conversion device may be prepared by fabricating a thin film of an oxide semiconductor on a substrate using oxide semiconductor fine particles, and then supporting the dye of the present invention on the thin film.

In this invention, it is preferable that the surface is electroconductive as a board | substrate which provides the thin film of an oxide semiconductor, and what is marketed can also be used. As a specific example, conductive metal oxides such as tin oxide coated with indium, fluorine, and antimony on a surface of glass or a transparent polymer material such as polyethylene terephthalate or polyethersulfone, or a metal thin film such as steel, silver, or gold may be used. The formed thing can be used. In this case, the conductivity is preferably 1000 Ω or less, particularly preferably 100 Ω or less.

As the fine particles of the oxide semiconductor, a metal oxide is preferable. As specific examples, oxides such as titanium, tin, zinc, tungsten, zirconium, gallium, indium, yttrium, niobium, tantalum and vanadium can be used. Of these, oxides such as titanium, tin, zinc, niobium and indium are preferable, among these, titanium oxide, zinc oxide and tin oxide are more preferable, and titanium oxide is most preferred. The oxide semiconductor may be used alone, or may be mixed or coated on the surface of the semiconductor.

The particle diameter of the fine particles of the oxide semiconductor is preferably 1 to 500 nm, more preferably 1 to 100 nm as the average particle diameter. In addition, the fine particles of the oxide semiconductor may be mixed with a large particle size and a small particle size, or may be used as a multilayer.

The oxide semiconductor thin film is a method of forming oxide semiconductor fine particles into a thin film directly on a substrate by spray spraying, a method of electrically depositing a semiconductor fine particle thin film using a substrate as an electrode, a slurry of semiconductor fine particles or semiconductor fine particles such as a semiconductor alkoxide. After applying the paste containing the fine particles obtained by hydrolyzing the precursor onto the substrate, it can be produced by a method of drying, curing or baking, and a method of applying the paste onto the substrate is preferred. In the case of this method, a slurry can be obtained by disperse | distributing the oxide semiconductor microparticles | fine-particles which are secondary aggregated so that an average primary particle diameter may be 1-200 nm in a dispersion medium by a conventional method.

The dispersion medium for dispersing the slurry can be used without particular limitation so long as it can disperse the semiconductor fine particles, and alcohols such as water and ethanol, ketones such as acetone and acetylacetone, or hydrocarbons such as hexane can be used, and these can be mixed and used. Among them, it is preferable to use water among them in order to reduce the viscosity change of the slurry. Moreover, a dispersion stabilizer can be used for the purpose of stabilizing the dispersion state of oxide semiconductor microparticles | fine-particles. Specific examples of the dispersion stabilizer that can be used include acids such as acetic acid, hydrochloric acid and nitric acid, or acetylacetone, acrylic acid, polyethylene glycol, and polyvinyl alcohol.

The substrate coated with the slurry can be fired, and its firing temperature is at least 100 ° C, preferably at least 200 ° C, and the upper limit is generally below the melting point (softening point) of the substrate, and usually the upper limit is 900 ° C, preferably 600. It is below ℃. In the present invention, the firing time is not particularly limited, but is generally within 4 hours.

It is preferable that the thickness of the thin film on a board | substrate in this invention is 1-200 micrometers, Preferably it is 1-50 micrometers. Although some thin layers of oxide semiconductor fine particles are welded when firing, such welding is not particularly troubled for the present invention.

In addition, the oxide semiconductor thin film may be subjected to secondary treatment. For example, the performance of a semiconductor thin film may be improved by directly depositing a thin film for each substrate and drying or refiring it in a solution such as an alkoxide, chloride, nitride or sulfide of the same metal as the semiconductor. Examples of the metal alkoxide include titanium ethoxide, titanium isopropoxide, titanium t-butoxide, n-dibutyl-diacetyl tin and the like, and an alcohol solution thereof can be used. As a chloride, titanium tetrachloride, tin tetrachloride, zinc chloride, etc. are mentioned, for example, The aqueous solution can be used. The oxide semiconductor thin film thus obtained is composed of fine particles of an oxide semiconductor.

In addition, the method of supporting the dye on the oxide semiconductor fine particles formed in the thin film phase in the present invention is not particularly limited, as a specific example by dispersing a solution obtained by dissolving the dye represented by the formula (1) in a solvent capable of dissolving, or dye The method of immersing the board | substrate with which the said oxide semiconductor thin film was provided in the obtained dispersion liquid is mentioned. The concentration in the solution or dispersion can be appropriately determined by the dye. The deposition time is usually from room temperature to the boiling point of the solvent, and the deposition time is about 1 minute to 48 hours. Specific examples of the solvent that can be used to dissolve the dye include methanol, ethanol, acetonitrile, dimethyl sulfoxide, dimethylformamide, acetone, t-butanol and the like. The dye concentration of the solution is usually suitably 1 × 10 ⁻⁶ M to 1 M, and preferably 1 × 10 ⁻⁵ M to 1 × 10 ⁻¹ M. In this way, the photoelectric conversion element of this invention which has oxide semiconductor microparticles | fine-particles on the thin film sensitized with dye can be obtained.

The dye represented by the formula (1) supported by the present invention may be one kind or may be mixed in several kinds. In addition, when mixing, another dye or a metal complex dye can be mixed with the dye of this invention. Examples of the metal complex dyes that can be mixed are not particularly limited, but ruthenium complexes, quaternary salts thereof, phthalocyanine, porphyrin, and the like are preferable, and organic dyes used for mixing include metal-free phthalocyanine, porphyrin, cyanine, merocyanine, Methine dyes such as oxonol, triphenylmethane, and acrylic acid dyes as shown in WO2002 / 011213, and dyes such as xanthene, azo, anthraquinone and perylene-based dyes (MK Nazeeruddin, A). .Kay, I.Rodicio, R.Humphry-Baker, E.Muller, P.Liska, N.Vlachopoulos, M.Gratzel, J. Am. Chem. Soc., Vol. 115, p . 6382 (1993). ). In the case of using two or more kinds of dyes, the dyes may be adsorbed onto the semiconductor thin film in sequence, or may be mixed and dissolved and adsorbed.

In the present invention, when the dye is supported on the thin film of the oxide semiconductor fine particles, it is preferable to support the dye in the presence of the inclusion compound in order to prevent the dyes from bonding. Examples of the inclusion compound include carboxylic acids such as deoxycholic acid, dehydrodeoxycholic acid, kenodeoxycholic acid, methyl ester of cholate, and sodium cholate, steroidal compounds such as polyethylene oxide and cholic acid, crown ether, cyclodextrin, and calix arene, Polyethylene oxide and the like can be used.

After the dye is supported, the semiconductor electrode surface can be treated with an amine compound such as 4-t-butyl pyridine or a compound having an acidic group such as acetic acid or propionic acid. As a treatment method, for example, a method of dipping a substrate provided with a thin film of semiconductor fine particles in which a dye is supported in an amine ethanol solution may be used.

In another aspect, the present invention provides a dye-sensitized solar cell comprising the dye-sensitized photoelectric conversion device, using a dye-sensitized photoelectric conversion device using the oxide semiconductor fine particles carrying the dye represented by the formula (1) In addition, conventional methods for manufacturing a solar cell using a conventional photoelectric conversion device may be applied, and, as a specific example, a photoelectric conversion device electrode (cathode) and a counter electrode supporting the dye represented by Formula 1 on the oxide semiconductor fine particles. (Anode), a redox electrolyte, a hole transport material, a p-type semiconductor, or the like.

Preferably, one example of a specific method of manufacturing a dye-sensitized solar cell of the present invention is the step of coating a titanium oxide paste on a conductive transparent substrate, baking the substrate coated with a paste to form a titanium oxide thin film, titanium oxide thin film Impregnating the formed substrate into a mixed solution in which the dye represented by Chemical Formula 1 is dissolved to form a titanium oxide film electrode on which the dye is adsorbed, and providing a second glass substrate having a counter electrode formed thereon. Forming a hole penetrating a glass substrate and a counter electrode, placing a thermoplastic polymer film between the counter electrode and the dye-adsorbed titanium oxide film electrode, and performing a heat compression process to perform the counter electrode and titanium oxide. Bonding a film electrode to the thermoplastic polymer film between the counter electrode and the titanium oxide film electrode through the hole; Implanting be and can be prepared through the step of sealing the thermoplastic polymer.

Redox electrolytes, hole transport materials, p-type semiconductors, and the like may be in the form of liquids, coagulants (gels and gels), solids, and the like. As liquids, redox electrolytes, dissolved salts, hole transport materials, p-type semiconductors, and the like are dissolved in a solvent, and at room temperature, dissolved salts, etc., in the case of coagulation bodies (gels and gels), these are polymer matrices or low molecular gelling agents. What was contained in etc. can be mentioned, respectively. As the solid, a redox electrolyte, a dissolved salt, a hole transport material, a p-type semiconductor, or the like can be used.

Examples of the hole transport material include an amine derivative, a conductive polymer such as polyacetylene, polyaniline, and polythiophene, and an object using a discotech liquid crystal phase such as triphenylene-based compound. Moreover, CuI, CuSCN, etc. can be used as a p-type semiconductor. It is preferable that the counter electrode has conductivity and catalyzes the reduction reaction of the redox electrolyte. For example, platinum, carbon, rhodium, ruthenium, or the like deposited on glass or a polymer film, or coated with conductive fine particles can be used.

As the redox electrolyte used in the solar cell of the present invention, a halogen redox electrolyte composed of a halogen compound having a halogen ion as a large ion and a halogen molecule, a ferrocyanate-ferrocyanate, a ferrocene-ferricinium ion, a cobalt complex and the like Metal redox-based electrolytes such as metal complexes, organic redox-based electrolytes such as alkylthiol-alkyldisulfides, viologen dyes, and hydroquinone-quinones, and the like, and halogen redox-based electrolytes are preferable. As a halogen molecule in the halogen redox electrolyte composed of halogen compound-halogen molecules, an iodine molecule is preferable. In addition, the halogen compound to a halogen ion as a counter ion LiI, NaI, KI, CaI _2, MgI _2, a halogenated metal salt such as CuI, or tetra-alkyl ammonium iodine, imidazolium iodine, the organic ammonium salt of halogen such as flutes Stadium iodine, Or I ₂ can be used.

In addition, when the redox electrolyte is configured in the form of a solution containing the same, an electrochemically inert one may be used as the solvent. Specific examples include acetonitrile, propylene carbonate, ethylene carbonate, 3-methoxy propionitrile, methoxy acetonitrile, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, butyrolactone, dimethoxyethane, dimethyl carbonate, 1,3-dioxolane, methylformate, 2-methyltetrahydrofuran, 3-methoxy-oxazolidin-2-one, sulfolane, tetrahydrofuran, water, and the like, in particular acetonitrile , Propylene carbonate, ethylene carbonate, 3-methoxypropionitrile, ethylene glycol, 3-methoxy-oxazolidin-2-one, butyrolactone and the like are preferable. The solvents may be used alone or in combination. In the case of a gel positive electrolyte, one containing an electrolyte or an electrolyte solution in a matrix such as an oligomer and a polymer, or one containing an electrolyte or an electrolyte solution in the same manner as a starch gelling agent can be used. The concentration of the redox electrolyte is preferably 0.01 to 99% by weight, more preferably 0.1 to 30% by weight.

In the solar cell of the present invention, a counter electrode (anode) is disposed in a photoelectric conversion element (cathode) on which a dye is carried on an oxide semiconductor fine particle on a substrate so as to face it, and a solution containing a redox electrolyte is filled therebetween. Can be obtained.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1 Synthesis of Dye

All reactions were run in an argon atmosphere and the solvent was distilled off with a suitable reagent purchased from Sigma-Adrich. 1H and 13C NMR spectra were measured with a Varian Mercury 300 spectrometer, elemental analysis with a Carlo Elba Instruments CHNS-O EA 1108 analyzer, and mass spectra with a JEOL JMS-SX102A instrument. Absorption and emission spectra were measured with a Perkin-Elmer Lambda 2S UV-visible spectrometer and a Perkin LS fluorescence spectrometer, respectively.

<Circulating Voltammetry> BAS 100B (Bioanalytical Systems, Inc.) was used as a cyclic voltammeter. A three-electrode system consisting of gold disks, working electrodes and platinum wire electrodes was used. The redox potential of the dye on TiO ₂ was measured in CH ₃ CN using 0.1 M ( n- C ₄ H ₉ ) ₄ N-PF ₆ at a scan rate of 50 mV s ⁻¹ (vs. Fc / Fc ⁺ ). .

I) 9-Bromo Cis, cis -1,7-diethoxy-3-isopropylzulolidine

Cis, cis- 1,7-diethoxy-3-isopropylzulolidine (5 g, 16.47 mmol) and N -bromosuccinimide (2.91 g, 16.47 mmol) were mixed in chloroform (100 ml) for 2 hours. . Water (30 ml) and brine were added to the mixed solution, and the organic layer was separated and dried over magnesium sulfate. The solid obtained after removal of the solvent under vacuum was chromatographed (eluent MC: Hx = 1: 1, R _f = 0.5) to give the title compound as a colorless oil (yield 70%).

1 H NMR (CDCl ₃ ): δ 7.27 (s, 1H), 7.17 (s, 1H), 4.34 (t, J = 6.0 Hz, 1H), 4.19 (t, J = 3.9 Hz, 1H), 3.72 (m, 2H), 3.57 (m, 2H), 3.22 (m, 2H), 3.00 (m, 1H), 2.36 (oct, J = 6.6 Hz, 1H), 1.97 (m, 4H), 1.26 (q, J = 6.6 Hz, 6H), 0.97 (d, J = 6.6 Hz, 3H), 0.85 (d, J = 6.9 Hz, 3H). 13C {1H} NMR (CDCl ₃ ): δ 141.0, 131.3, 130.3, 125.0, 124.1, 107.2, 73.8, 64.2, 63.7, 61.9, 42.9, 28.8, 27.4, 27.1, 20.5, 17.0, 15.7, 15.6. MS: m / z 381 [M ⁺ ]. Anal. Calcd for C ₁₉ H ₂₈ BrNO ₂ : C, 59.69; H, 7.38. Found: C, 59.42; H, 7.24.

II) 9- (2,2'-bithiophen-5-yl)- Cis, cis -1,7-diethoxy-3-isopropylzulolidine (Compound 3a)

Compound (1g, 2.61mmol) obtained in step I), 2- (2,2'-bithiophen-5-yl) -4,4,5,5, -tetramethyl-1,3,2-di Oxaborolane (0.915 g, 3.132 mmol), Pd (PPh ₃ ) ₄ (0.150 g, 0.13 mmol) and 2M K ₂ CO ₃ aqueous solution (2 ml) were refluxed in THF (100 ml) for 12 hours. The reaction solution was cooled, water (30 ml) and brine were added, and the organic layer was separated and dried over magnesium sulfate. The solvent was removed under vacuum and the resulting solid was chromatographed (eluent MC: Hx = 1: 1, R _f = 0.3) to give the title compound as a yellow solid (yield 70%).

Mp: 189 ° C. 1 H NMR (CDCl ₃ ): δ 7.42 (s, 1H), 7.32 (s, 1H), 7.15 (t, J = 6.3 Hz, 1H), 7.08 (d, J = 3.9 Hz, 1H), 7.03 (d, J = 3.9 Hz, 1H), 7.00 (d, J = 3.3 Hz, 1H), 6.99 (d, J = 3.3 Hz, 1H), 4.42 (t, J = 5.1 Hz, 1H), 4.30 (t, J = 3.9 Hz, 1H), 3.75 (m, 2H), 3.67 (m, 2H), 3.27 (m, 2H), 3.05 (m, 1H), 2.42 (oct, J = 6.9 Hz, 1H), 2.06 (m, 4H), 1.29 (q, J = 7.1 Hz, 6H), 0.99 (d, J = 6.6 Hz, 3H), 0.88 (d, J = 6.9 Hz, 3H). 13C {1H} NMR (CDCl ₃ ): δ 139.8, 138.7, 136.4, 135.5, 133.9, 133.3, 132.2, 131.5, 130.3, 128.2, 127.4, 124.8, 122.1, 109.8, 72.7, 70.8, 65.8, 63.8, 62.7, 42.8 , 28.8, 27.4, 27.2, 20.4, 19.3, 15.4, 15.2. MS: m / z 467 [M &lt; + &gt;]. Anal. Calcd for C ₂₇ H ₃₃ NO ₂ S ₂ : C, 69.34; H, 7.11. Found: C, 69.12; H, 6.95.

III) 9- (3,3'-dimethyl-2,2'-bithiophen-5-yl)- Cis, cis -1,7-diethoxy-3-isopropylzulolidine (Compound 3b)

2- (3,3'-dimethyl instead of 2- (2,2'-bithiophen-5-yl) -4,4,5,5, -tetramethyl-1,3,2-dioxaborolane Same process as in Step II) above except that -2,2'-bithiophen-5-yl) -4,4,5,5, -tetramethyl-1,3,2-dioxaborolan is used Was carried out to give the title compound (yield 65%).

Mp: 187 ° C. 1 H NMR (CDCl ₃ ): δ 7.40 (s, 1H), 7.29 (s, 1H), 7.24 (d, J = 5.1 Hz, 1H), 6.95 (s, 1H), 6.91 (d, J = 5.1 Hz, 1H), 4.42 (t, J = 5.1 Hz, 1H), 4.29 (t, J = 3.9 Hz, 1H), 3.77 (m, 2H), 3.63 (m, 2H), 3.26 (m, 2H), 3.05 ( m, 1H), 2.40 (oct, J = 6.9 Hz, 1H), 2.22 (s, 3H), 2.17 (s, 3H), 2.01 (m, 4H), 1.27 (q, J = 6.9 Hz, 6H), 0.99 (d, J = 6.6 Hz, 3H), 0.89 (d, J = 6.1 Hz, 3H). 13C {1H} NMR (CDCl ₃ ): δ 139.0, 138.5, 137.3, 135.8, 134.1, 133.3, 130.5, 130.3, 129.4, 125.9, 125.3, 122.1, 121.0, 109.8, 72.1, 70.7, 65.8, 64.5, 63.8, 48.0 , 31.9, 31.5, 29.2, 27.2, 27.1, 20.4, 19.4, 15.5, 15.1. MS: m / z 467 [M &lt; + &gt;]. Anal. Calcd for C ₂₉ H ₃₇ NO ₂ S ₂ : C, 70.26; H, 7.52. Found: C, 69.89; H, 7.13.

IV) 9- (2,2'-bis (3,4-ethylenedioxythiophene) -5-yl)- Cis, cis -1,7-diethoxy-3-isopropylzulolidine (Compound 3c)

4,4,5,5, -instead of 2- (2,2'-bithiophen-5-yl) -4,4,5,5, -tetramethyl-1,3,2-dioxaborolane Tetramethyl-2- (2,2 ', 3,3'-tetrahydro-5,7'-bithieno [3,4- b ] [1,4] dioxin-7-yl) -1,3 The title compound was obtained in the same manner as Step II) except that, 2-dioxaborolane (1.278 g, 3.132 mmol) was used (yield 77%).

Mp: 198 ° C. 1 H NMR (CDCl ₃ ): δ 7.55 (s, 1 H), 7.42 H. Choi et al. / Tetrahedron 63 (2007) 1553.1559 (s, 1H), 6.23 (s, 1H), 4.43 (t, J = 5.1 Hz, 1H), 4.34.4.25 (m, 8H), 4.24 (t, J = 3.7 Hz, 1H), 3.74 (m, 2H), 3.66 (m, 2H), 3.26 (m, 2H), 3.03 (m, 1H), 2.41 (oct, J = 6.9 Hz, 1H), 2.06 (m, 4H), 1.26 (q, J = 7.2 Hz, 6H), 0.98 (d, J = 6.9 Hz, 3H), 0.88 (d, J = 6.3 Hz, 3H). 13C {1H} NMR (CDCl ₃ ): δ 141.4, 137.8, 136.5, 136.0, 127.9, 126.8, 122.5, 121.5, 119.8, 116.9, 110.6, 105.4, 97.0, 92.9, 73.9, 73.1, 65.9, 65.1, 65.0, 64.7 , 63.7, 63.3, 62.3, 42.9, 29.2, 27.5, 25.7, 20.6, 17.6, 15.8, 15.7. MS: m / z 583 [M &lt; + &gt;]. Anal. Calcd for C ₃₁ H ₃₇ NO ₆ S ₂ : C, 63.78; H, 6.39. Found: C, 63.55; H, 6.18.

V) 9- (5'-formyl-2,2'-bithiophen-5-yl)- Cis, cis -1,7-diethoxy-3-isopropylzulolidine (Compound 4a)

To anhydrous ethanol solution of compound 3a (0.22 g, 0.47 mmol) obtained in step II) n- BuLi (0.35 ml, 1.6 M solution in hexane) was added under argon. After 3 hours, DMF (0.05 g, 0.7 mmol) was added thereto at 0 ° C. under argon and washed with 5% KOH. The reaction solution was dried over magnesium sulfate, the solvent was removed, and the obtained solid was subjected to silica gel chromatography (eluent MC: Hx = 1: 1, R _f = 0.2) to obtain the title compound (yield 75%).

Mp: 186 ° C. 1 H NMR (CDCl ₃ ): δ 9.82 (s, 1H), 7.64 (d, J = 3.9 Hz, 1H), 7.43 (s, 1H), 7.33 (s, 1H), 7.28 (d, J = 3.9 Hz, 1H), 7.28 (d, J = 3.9 Hz, 1H), 7.20 (d, J = 3.9 Hz, 1H), 7.08 (d, J = 3.9 Hz, 1H), 4.41 (t, J = 5.4 Hz, 1H) , 4.30 (t, J = 3.7 Hz, 1H), 3.77 (m, 2H), 3.65 (m, 2H), 3.28 (m, 2H), 3.08 (m, 1H), 2.41 (oct, J = 6.3 Hz, 1H), 2.02 (m, 4H), 1.29 (q, J = 6.9 Hz, 6H), 0.99 (d, J = 6.6 Hz, 3H), 0.88 (d, J = 6.3 Hz, 3H). 13C {1H} NMR (CDCl ₃ ): δ 182.6, 145.8, 143.2, 136.2, 134.5, 133.9, 133.3, 132.2, 131.5, 130.8, 128.2, 127.4, 124.8, 122.1, 111.8, 72.5, 70.1, 65.8, 63.8, 62.7 , 42.8, 28.8, 27.4, 27.2, 20.4, 19.3, 15.4, 15.2. MS: m / z 495 [M &lt; + &gt;]. Anal. Calcd for C ₂₈ H ₃₃ NO ₃ S ₂ : C, 67.84; H, 6.71. Found: C, 67.36; H, 6.24.

VI) 9- (5'-formyl-3,3'-dimethyl-2,2'-bithiophen-5-yl)- Cis, cis -1,7-diethoxy-3-isopropylzulolidine (Compound 4b)

The title compound was obtained in the same manner as Step V) except that compound 3b was used instead of compound 3a (yield 72%).

Mp: 179 ° C. 1 H NMR (CDCl ₃ ): δ 9.82 (s, 1H), 7.58 (s, 1H), 7.40 (s, 1H), 7.29 (d, J = 5.1 Hz, 1H), 6.98 (s, 1H), 4.41 ( t, J = 5.1 Hz, 1H), 4.29 (t, J = 3.9 Hz, 1H), 3.74 (m, 2H), 3.63 (m, 2H), 3.27 (m, 2H), 3.07 (m, 1H), 2.41 (oct, J = 6.9 Hz, 1H), 2.31 (s, 3H), 2.25 (s, 3H), 2.00 (m, 4H), 1.28 (q, J = 7.2 Hz, 6H), 0.99 (d, J = 6.9 Hz, 3H), 0.88 (d, J = 6.3 Hz, 3H). 13C {1H} NMR (CDCl ₃ ): δ 182.8, 143.0, 141.2, 140.4, 139.2, 138.4, 137.0, 130.5, 127.1, 126.0, 125.0, 122.9, 122.0, 120.6, 112.1, 73.7, 73.1, 64.0, 63.5, 62.3 , 42.9, 31.9, 31.5, 29.1, 27.2, 27.1, 22.6, 17.4, 15.8, 15.7. MS: m / z 523 [M &lt; + &gt;]. Anal. Calcd. for C ₃₀ H ₃₇ NO ₃ S ₂ : C, 68.80; H, 7.12. Found: C, 68.55; H, 6.89.

VII) 9- (5'-formyl-2,2'-bis (3,4-ethylenedioxythiophene) -5-yl)- Cis, cis -1,7-diethoxy-3-isopropylzulolidine (Compound 4c)

The title compound was obtained in the same manner as Step V) except that compound 3c was used instead of compound 3a (yield 75%).

Mp: 186 ° C. 1 H NMR (CDCl ₃ ): δ 9.86 (s, 1H), 7.58 (s, 1H), 7.45 (s, 1H), 4.42 (m, 9H), 4.31 (t, J = 3.7 Hz, 1H), 3.73 ( m, 2H), 3.64 (m, 2H), 3.27 (m, 2H), 3.04 (m, 1H), 2.41 (oct, J = 6.3 Hz, 1H), 2.08 (m, 4H), 1.27 (q, J = 7.5 Hz, 6H), 0.99 (d, J = 6.6 Hz, 3H), 0.88 (d, J = 6.0 Hz, 3H). 13C {1H} NMR (CDCl ₃ ): δ 179.6, 159.0, 156.0, 138.9, 137.7, 136.5, 133.4, 132.1, 130.5, 129.8, 128.7, 125.9, 124.9, 121.0, 106.9, 73.7, 73.3, 65.8, 65.4, 65.1 , 64.7, 63.7, 63.3, 62.3, 42.3, 29.1, 27.2, 25.5, 20.7, 17.6, 15.8, 15.7. MS: m / z 611 [M &lt; + &gt;]. Anal. Calcd for C ₃₂ H ₃₇ NO ₇ S ₂ : C, 62.82; H, 6.10. Found: C, 62.55; H, 5.95.

VIII) 2-cyano-3- (5 '-( Cis, cis -1,7-diethoxy-3-isopropylzulolidinyl) -2,2'-bithiophen-5-yl) acrylic acid (Compound 1a)

A mixture of compound 4a (0.38 g, 0.76 mmol) and cyanoacetic acid (0.13 g, 1.53 mmol) was vacuum dried and then added to MeCN (60 ml) and piperidine (0.07 ml, 0.76 mmol), and the mixed solution It was refluxed for 6 hours. The reaction solution was cooled and the organic layer was removed under vacuum, and the obtained solid was subjected to silica gel chromatography (eluent MC: MeOH = 2: 1, R _f = 0.6) to obtain the title compound (yield 51%).

Mp: 225 ° C. _{1H NMR (DMSO- d 6):} δ 8.12 (s, 1H), 7.65 (d, J = 3.3 Hz, 1H), 7.39 (d, J = 3.6 Hz, 1H), 7.37 (d, J = 3.6 Hz, 1H), 7.35 (s, 1H), 7.32 (s, 1H), 7.22 (d, J = 3.3 Hz, 1H), 4.37 (t, J = 5.8 Hz, 1H), 4.28 (t, J = 3.9 Hz, 1H), 3.70 (m, 2H), 3.61 (m, 2H), 3.20 (m, 2H), 3.06 (m, 1H), 2.25 (oct, J = 6.3 Hz, 1H), 1.90 (m, 4H), 1.19 (q, J = 6.9 Hz, 6H), 0.94 (d, J = 6.9 Hz, 3H), 0.82 (d, J = 6.9 Hz, 3H). 13C {1H} NMR (DMSO- d ₆ ): δ 164.3, 150.6, 145.8, 142.3, 142.0, 141.7, 140.6, 136.6, 135.3, 134.8, 131.7, 126.9, 123.6, 122.5, 122.0, 119.1, 118.7, 73.7, 72.8 , 64.2, 63.0, 62.5, 41.4, 29.7, 28.6, 28.2, 22.5, 17.0, 15.4, 15.3. MS: m / z 562 [M &lt; + &gt;]. Anal. Calcd for C ₃₁ H ₃₄ N ₂ O ₄ S ₂ : C, 66.16; H, 6.09. Found: C, 65.78; H, 5.87.

IX) 2-cyano-3- (5 '-( Cis, cis -1,7-diethoxy-3-isopropylzulolidinyl) -3,3'-dimethyl-2,2'-bithiophen-5-yl) acrylic acid (Compound 1b)

The title compound was obtained in the same manner as Step VIII) except that compound 4b was used instead of compound 4a (yield 56%).

Mp: 212 ° C. _{1H NMR (DMSO- d 6):} δ 8.03 (s, 1H), 7.55 (s, 1H), 7.32 (s, 1H), 7.28 (s, 1H), 7.15 (s, 1H), 4.37 (t, J = 5.3 Hz, 1H), 4.28 (t, J = 3.9 Hz, 1H), 3.69 (m, 2H), 3.57 (m, 2H), 3.27 (m, 2H), 3.08 (m, 1H), 2.35 (oct , J = 6.8 Hz, 1H), 2.20 (s, 3H), 2.17 (s, 3H), 1.90 (m, 4H), 1.18 (q, J = 7.2 Hz, 6H), 0.94 (d, J = 6.9 Hz , 3H), 0.83 (d, J = 6.9 Hz, 3H). 13C {1H} NMR (DMSO- d ₆ ): δ 163.3, 149.0, 145.4, 144.8, 141.5, 137.8, 136.1, 135.6, 135.3, 134.8, 132.2, 128.9, 127.3, 125.5, 124.6, 124.1, 119.0, 73.8, 72.8 , 64.3, 63.1, 61.5, 41.4, 40.4, 38.6, 29.7, 28.6, 28.4, 23.0, 17.2, 15.4, 15.1. MS: m / z 523 [M &lt; + &gt;]. Anal. Calcd. for C ₃₃ H ₃₈ N ₂ O ₄ S ₂ : C, 67.09; H, 6.48. Found: C, 66.79; H, 6.33.

X) 2-cyano-3- (5 '-( Cis, cis -1,7-diethoxy-3-isopropylzulolidinyl) -2,2'-bis (3,4-ethylene-dioxythiophene) -5-yl) acrylic acid (Compound 1c)

The title compound was obtained in the same manner as Step VIII) except that compound 4c was used instead of compound 4a (yield 60%).

Mp: 232 ° C. _{1H NMR (DMSO- d 6):} δ 8.03 (s, 1H), 7.44 (s, 1H), 7.35 (s, 1H), 4.42 (m, 8H), 4.35 (t, J = 5.9 Hz, 1H), 4.27 (t, J = 3.8 Hz, 1H), 3.70 (m, 2H), 3.57 (m, 2H), 3.16 (m, 2H), 3.10 (m, 1H), 2.35 (oct, J = 6.8 Hz, 1H ), 1.93 (m, 4H), 1.17 (q, J = 7.3 Hz, 6H), 0.95 (d, J = 6.3 Hz, 3H), 0.83 (d, J = 6.9 Hz, 3H). 13C {1H} NMR (DMSO- d ₆ ): δ 161.8, 155.9, 144.6, 140.9, 140.4, 135.9, 126.1, 125.4, 122.4, 120.1, 118.4, 118.1, 115.3, 109.1, 108.1, 104.7, 103.8, 72.5, 72.1 , 67.2, 65.2, 64.4, 63.0, 61.2, 59.6, 47.3, 28.6, 23.0, 22.5, 20.1, 17.2, 15.5, 15.4. MS: m / z 678 [M &lt; + &gt;]. Anal. Calcd for C ₃₅ H ₃₈ N ₂ O ₈ S ₂ : C, 61.93; H, 5.64. Found: C, 61.56; H, 5.34.

Example 2 Fabrication of Dye-Sensitized Solar Cell

In order to evaluate the current-voltage characteristics of the dye compound, a solar cell was manufactured using a 12 + 8 μm TiO ₂ transparent layer. TiO ₂ paste (Solaronix, 13 nm paste) was screen printed to prepare a 12 μm thick first TiO ₂ layer, and another light paste (CCIC, HWP-400) was used to make a 2 μm thick TiO ₂ scattering layer. Prepared. This TiO ₂ bilayer film was treated with 40 mM TiCl ₄ solution and dried at 500 ° C. for 30 minutes. The treated film was cooled to 60 ° C. and then impregnated with a solution of each of the dye compounds 1a to 1c of the present invention prepared in steps VIII) to X) above (0.3 mM dye in 10 mM kenodioxycholic acid ethanol). A sealed sandwich cell was assembled by heating a hot melt film (Surlyn 1702, 25 μm thick) as a spacer between the dye-adsorbed TiO ₂ electrode and the platinum-electrode. As the electrolyte solution, 0.6 M 3-hexyl-1,2-dimethylimidazolium iodine, 0.04 MI ₂ , 0.025 M LiI, 0.05 M guanidium thiocyanate and 0.28 M tert -butylpyridine were dissolved in acetonitrile. Used.

Example 3 Measurement of Physical Properties of Prepared Dye and Dye-Sensitized Solar Cell

Absorbance and emission spectra of each of the dye compounds 1a to 1c of the present invention prepared in the above steps VIII) to X) (1a: solid line, 1b: bar line, 1c: dotted line), and supported on the TiO ₂ layer The absorbance spectrum of the city (1a: bar-dotted line, 1b: bar-dotted-dotted line, 1c: short barline) is shown in FIG. The emission spectrum was obtained by excitation at 450 nm for compound 1a, 410 nm for 1b, and 500 nm for 1c at 298K.

From the graph of FIG. 1, it can be seen that when compared with the absorption spectrum of Compound 1a, the absorption spectrum of Compound 1b is shifted toward blue, and the absorption spectrum of Compound 1c is shifted toward red.

This difference is due to the difference in the molecular structure of the dye compound, and the optimized structure (calculated by TD-DFT for B3LYP / 3-21G) of each of compounds 1a to 1c is shown in FIG. 2 ((a): 1a, ( b): 1b, (c): 1c). The angle generated at the top observed in FIGS. 2A and 2B is the twist angle between gluolidine and thienyl units, and the angle generated at the bottom is the bilateral angle of two thienyl units. The upper angle observed in (c) of FIG. 2 is the dihedral angle of gluolidine and 3,4-ethylenedioxythiophene, and the lower angle is formed of bis (3,4-ethylenedioxythiophene). It is two-sided. From the molecular structure of FIG. 2, it can be seen that when compared to compound 1a, compound 1b is more twisted and compound 1c is less twisted, thus being closer to the plane.

In addition, the geometries of each of Compounds 1a and 1c (molecular orbitals of HOMO and LUMO, calculated by TD-DFT for B3LYP / 3-21G) are shown in FIG. 3. From this, it can be seen that the electron distribution is shifted from the HOMO-LUMO excitation aniline unit to the cyanoacrylic acid group, and the change of the electron distribution induced by photoexcitation leads to efficient charge separation.

The optical and redox performance of each of the dye compounds 1a to 1c of the present invention, and the photoelectrochemical characteristics and the IPCE spectrum of the solar cell manufactured using the respective dye compounds were measured, and the results of FIGS. 4, 5 and Table 1 shows.

In Table 2, N719 is a ruthenium-based catalyst used in a conventional dye-sensitized solar cell and has a structure as follows.

In Table 1, ε is the extinction coefficient, E _ox is the oxidation potential, E _{0 -0} is the voltage at the intersection of the absorption and emission spectrum, J _sc is a short-circuit photocurrent density, V _oc is an open circuit The open circuit photovoltage, ff, is the fill factor, and η is the overall photoconversion efficiency. In addition, a is the absorption spectrum is measured in ethanol solution, b is the redox potential of the dye on TiO ₂ 0.1M ( n -C ₄ H _{9 at} a scan rate of 50 mV s ^-1 (vs. Fc / Fc ⁺ ) ) Is measured in CH ₃ CN using ₄ N-PF ₆ , c is determined from the intersection of the absorption and emission spectra of E _0-0 in ethanol, d is E _LUMO is determined by E _ox -E _0-0 E means that the performance of the fuel-sensitized solar cell is measured by 0.18 cm ² working area.

From the IPCE graph of the solar cell of FIG. 4 and the photocurrent voltage curve (under AM 1.5 radiation) of the solar cell of FIG. 5 (1a: solid line, 1b: bar line, 1c: dashed line, N719: bar line-dashed line), of compound 1c It can be seen that the IPCE maximum is lower than that obtained in compounds 1a and 1b and the overall conversion efficiency is also low.

These results indicate that the efficiency of the dye depends largely on the degree of aggregation of the dye on the TiO ₂ layer rather than the amount of dye adsorption, which is also related to the twisted nonplanar structure of the dye compounds of the present invention. In other words, the photoelectric conversion efficiency of the dye is greatly changed according to the structural modification of the bithiophene linking moiety, the higher the twist between the gluolidine and thienyl unit, the higher the photoelectric conversion efficiency.

The novel gluolidine-based dyes of the present invention exhibit improved molar absorption coefficient, J _sc (single-circuit photocurrent density) and photovoltaic conversion efficiency than conventional metal complex dyes, which can greatly improve the efficiency of solar cells and reduce the cost of expensive columns. Purification is possible without the use of the dye can significantly lower the synthesis cost.

Claims (9)

Julolidine-based dye represented by Formula 1 below: [Formula 1]

Where R ₁ and R ₂ are each independently hydrogen, C _1-12 alkyl or C _1-12 alkoxy, where C _1-12 alkoxy may combine with each other to form an oxygen-containing heterocycle; n is an integer from 2 to 5, optionally two or more thiophene units may be linked to a vinyl group. The method of claim 1, Julolidine-based dye, characterized in that the dye is one of those represented by the formula (1a to 1c): [Formula 1a]

[Formula 1b]

[Formula 1c]

(1) a compound of formula 3 is prepared by reacting bromozuloridine with a compound of formula 2 and Suzuki. (2) preparing a compound of formula 4 by lithiation of the compound of formula 3 with n-butyllithium and then cooling with dimethylformamide successively; (3) reacting a compound of formula 4 with cyanoacetic acid in the presence of piperidine in CH ₃ CN Method for preparing a gluolidine-based dye represented by the formula (1) of claim 1: [Formula 2]

[Formula 3]

[Formula 4]

Wherein R ₁ , R ₂ and n are as defined in claim 1. A dye-sensitized photoelectric conversion device comprising oxide semiconductor fine particles carrying the gluolidine-based dye of claim 1. The method of claim 4, wherein A dye-sensitized photoelectric conversion device characterized in that a gluolidine-based dye is supported on the oxide semiconductor fine particles in the presence of an inclusion compound. The method of claim 4, wherein Dye-sensitized photoelectric conversion device, characterized in that the oxide semiconductor fine particles contain titanium dioxide as an essential component. The method of claim 4, wherein Dye-sensitized photoelectric conversion device, characterized in that the oxide semiconductor fine particles have an average particle diameter of 1 to 500 nm. A dye-sensitized solar cell comprising the dye-sensitized photoelectric conversion device of claim 4 as an electrode. The method of claim 8, Wherein the dye-sensitized solar cell, coating a titanium oxide paste on a conductive transparent substrate, baking the paste-coated substrate to form a titanium oxide thin film, the substrate in which the titanium oxide thin film is formed Impregnating the dissolved mixed solution to form a titanium oxide film electrode on which dye is adsorbed; providing a second glass substrate having a counter electrode formed thereon; a hole penetrating the second glass substrate and the counter electrode; Forming a thermoplastic polymer film between the counter electrode and the titanium oxide film electrode on which the dye is adsorbed, and performing a heat compression process to bond the counter electrode and the titanium oxide film electrode to each other through the hole. Injecting an electrolyte into the thermoplastic polymer film between the counter electrode and the titanium oxide film electrode, and the thermoplastic polymer The dye-sensitized solar cell, characterized in that is produced through the step of sealing.

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