WO2011132573A1 - Fullerene derivative and method for producing same - Google Patents

Abstract

Disclosed is a fullerene derivative having superior electrical characteristics. Specifically disclosed is a fullerene derivative having the structure represented by formula (1). [In formula (1), ring A represents a C₆₀ or more fullerene ring. Ring B¹ and ring B² are independent and represent C_3-6 heterocycles. R¹ and R² are independent and represent monovalent functional groups. Q represents a divalent organic group, bonded to a carbon atom of ring B¹ and ring B². j and k represent integers of 0 - 8. When a plurality of R¹'s is present, each R¹ can be different from the others. When a plurality of R²'s is present, each R² can be different from the others. C1, C2, C3 and C4 are carbon atoms constituting ring A, and C1 and C2 and also C3 and C4 are each adjacent in ring A.]

Description

Fullerene derivative and method for producing the same

The present invention relates to a fullerene derivative, a method for producing the fullerene derivative, a composition containing the fullerene derivative, and an organic photoelectric conversion device using the composition.

An organic semiconductor material having a property of transporting an electron or hole (hole) has been studied for application to an organic photoelectric conversion element such as an organic thin film solar cell or an optical sensor. For example, an organic thin film using a fullerene derivative Solar cells are being considered.

As such fullerene derivatives, for example, [6,6] -phenyl C ₆₁ -butyric acid methyl ester (hereinafter sometimes referred to as [60] -PCBM) is known (see Non-Patent Document 1).

That is, the present invention provides the following.
[1] A fullerene derivative having a structure represented by the following formula (1).

[In Formula (1), the A ring represents a fullerene ring having 60 or more carbon atoms. B ¹ ring and ^{B 2} ring represents a heterocyclic carbon number of 3-6. R ¹ and R ² independently represent a monovalent functional organic group. Q represents a divalent organic group and is bonded to the carbon atom of the B ¹ ring and the B ² ring. j and k each independently represents an integer of 0 to 8. When a plurality of R ¹ are present, R ¹ may be different from each other. If the R ² is plurally present, R ² to each other may be different from each other. C1, C2, C3 and C4 are carbon atoms constituting the A ring, and C1 and C2, C3 and C4 are adjacent to each other in the A ring. ]
[2] A composition comprising the fullerene derivative according to [1] and an electron donating compound.
[3] a pair of electrodes consisting of an anode and a cathode;
The organic photoelectric conversion element which has a layer containing the fullerene derivative as described in [1] clamped between a pair of electrodes.
[4] A pair of electrodes consisting of an anode and a cathode;
An organic photoelectric conversion device having a layer containing the composition according to [2] sandwiched between a pair of electrodes.
[5] A pair of electrodes consisting of an anode and a cathode;
An active layer sandwiched between a pair of electrodes, comprising an electron-accepting layer containing the fullerene derivative according to [1] and an electron-donating layer containing an electron-donating compound bonded to the electron-accepting layer. An organic photoelectric conversion element having an active layer.
[6] Fullerene and a glycine derivative selected from the group consisting of N-methoxymethylglycine, N- (2- (2-methoxyethoxy) ethyl) glycine and [2- (2-methoxyethoxy) ethylamino] acetic acid; Reacting the bisaldehyde compound 5- (5- (5-formylthiophen-2-yl) thiophen-2-yl) thiophene-2-carbaldehyde with heating under reflux in a solvent;
The method for producing a fullerene derivative according to [1], comprising a step of removing the solvent and separating and purifying by silica gel flash column chromatography and preparative thin layer chromatography.

FIG. 1 is a schematic cross-sectional view showing a configuration example (1) of an organic photoelectric conversion element. FIG. 2 is a schematic cross-sectional view showing a configuration example (2) of the organic photoelectric conversion element.

DESCRIPTION OF SYMBOLS 10 Organic photoelectric conversion element 20 Substrate 32 1st electrode 34 2nd electrode 40 Active layer 42 Electron donating layer 44 Electron accepting layer

Hereinafter, the present invention will be described in detail. In the following description, there are cases where description is made with reference to the drawings, but the drawings only schematically show the shape, size, and arrangement of the components to the extent that the invention can be understood. The invention is not particularly limited. In addition, the same components shown in a plurality of drawings are denoted by the same reference numerals, and redundant description thereof may be omitted.

<Fullerene derivative>
The fullerene derivative of the present invention has a structure represented by the following formula (1).

In the structure of the formula (1), R ¹ and R ² represent a monovalent functional group. As examples of the monovalent functional group, an alkyl group, an alkoxy group, an aryl group, a halogen atom, a monovalent heterocyclic group, a group having an ester structure, and a group represented by the following formula (5) are preferable. Further, when a plurality of R ¹ are present, R ¹ may be different from each other. If the R ² is plurally present, R ² to each other may be different from each other.

In the formula (5), m represents an integer of 1 to 6, n represents an integer of 1 to 4, and r represents an integer of 0 to 5. When a plurality of m are present, the plurality of m may be different from each other.

In the structure of the above formula (1), the alkyl group represented by R ¹ and R ² usually has 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms. The chain may be branched or branched, and may be a cycloalkyl group.

Specific examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl, 3-methylbutyl, pentyl, hexyl and 2-ethylhexyl. Group, heptyl group, octyl group, nonyl group, decyl group, lauryl group.

The hydrogen atom in the alkyl group may be substituted with a halogen atom. Specific examples of the alkyl group in which a hydrogen atom is substituted with a halogen atom include a monohalomethyl group, a dihalomethyl group, a trihalomethyl group, and a pentahaloethyl group. As the halogen atom for substituting a hydrogen atom, a fluorine atom is preferable. Specific examples of the alkyl group in which a hydrogen atom is substituted with a fluorine atom include a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a perfluorohexyl group, and a perfluorooctyl group.

In the structure of the above formula (1), the alkoxy group represented by R ¹ and R ² usually has 1 to 20 carbon atoms and may be linear or branched. It may be a group. Specific examples of the alkoxy group include methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, cyclohexyloxy group, Examples include heptyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, 3,7-dimethyloctyloxy group and lauryloxy group.

The hydrogen atom in the alkoxy group may be substituted with a halogen atom. As the halogen atom for substituting a hydrogen atom, a fluorine atom is preferable. Specific examples of the alkoxy group in which a hydrogen atom is substituted with a fluorine atom include a trifluoromethoxy group, a pentafluoroethoxy group, a perfluorobutoxy group, a perfluorohexyloxy group, and a perfluorooctyloxy group.

In the structure of the formula (1), the aryl group represented by R ¹ and R ² usually has 6 to 60 carbon atoms and may have a substituent. As the substituent that the aryl group may have, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, A cycloalkyl group having usually 3 to 20 carbon atoms, preferably 3 to 12 carbon atoms, more preferably 3 to 6 carbon atoms, usually 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, more preferably Is a linear or branched alkyl group having 1 to 6 and a cycloalkyl group having usually 3 to 20, preferably 3 to 12, more preferably 3 to 6 carbon atoms in the structure. The alkoxy group contained in is mentioned.

Specific examples of the aryl group which may be substituted include a phenyl group and a C ₁ to C ₁₂ alkoxyphenyl group (C ₁ to C ₁₂ indicate that the number of carbon atoms is 1 to 12. In the following description, Similarly, the number attached to C representing a carbon atom may represent the number of carbon.), C ₁ -C ₁₂ alkylphenyl group, 1-naphthyl group, 2-naphthyl group, and the like. An aryl group of 6 to 20 is preferable, and a C ₁ to C ₁₂ alkoxyphenyl group and a C ₁ to C ₁₂ alkylphenyl group are more preferable.
A hydrogen atom in the aryl group may be substituted with a halogen atom. As the halogen atom for substituting a hydrogen atom, a fluorine atom is preferable.

In the structure of the formula (1), examples of the halogen atom represented by R ¹ and R ² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In the structure of the formula (1), the monovalent heterocyclic group represented by R ¹ and R ² is preferably a monovalent aromatic heterocyclic group. Examples of the monovalent heterocyclic group represented by R ¹ and R ² include a thienyl group, a pyridyl group, a furyl group, a piperidyl group, a quinolyl group, an isoquinolyl group, and a pyrrolyl group.

Examples of the group having an ester structure represented by R ¹ and R ² in the structure of the formula (1) include methyl butyrate, butyl butyrate, isopropyl butyrate, and 3-ethylthienyl butyrate from the alcohol side portion of the ester. Examples include groups in which one hydrogen atom has been removed.
One embodiment of the group having an ester structure includes a group represented by the following formula (6).

In formula (6), p represents an integer of 0 to 10. q represents an integer of 0 to 10.

In the group of the formula (5), m is preferably 2 from the viewpoint of easy availability of raw materials. r is preferably an integer of 0 to 3 from the viewpoint of charge transportability.

In the structure of the formula (1), the hydrogen atom in the alkyl group, alkoxy group, aryl group or monovalent heterocyclic group represented by R ¹ and R ² is an alkoxy group, aryl group, halogen atom, 1 It may be substituted with a valent heterocyclic group or a group having an ester structure. Specific examples of the alkyl group, alkoxy group, aryl group, halogen atom, monovalent heterocyclic group, and group having an ester structure include the same groups as the corresponding groups already described.

In the structure of the formula (1), j and k independently represent an integer of 0 to 8. Among these, j and k are preferably integers of 1 to 3.

In the structure of the formula (1), the A ring represents a fullerene ring (fullerene skeleton) having 60 or more carbon atoms. The A ring is preferably a C ₆₀ fullerene ring or a C ₇₀ fullerene ring from the viewpoint of easy availability of the raw material (fullerene). C1, C2, C3 and C4 are carbon atoms constituting the A ring (fullerene ring), and are carbon atoms shared by the A ring and the B ring (B ¹ ring and B ² ring) described later.

In the structure of the formula (1), each of the B ¹ ring and the B ² ring includes a pair of adjacent carbon atoms (C 1 and C 2 and C 3 and C 4) of the A ring so as to be adjacent to the A ring. An added ring structure. Specific examples of the B ¹ ring and B ² ring include ring B 3, ring B 4 and ring B 5 having the following structures.

The ring B4 is preferable as the ring B from the viewpoint of ease of synthesis. From the viewpoint of further increasing the Voc (open end voltage) of the fullerene derivative, it is preferable that both of the two B rings are the ring B4. In Ring B3 and Ring B4, any two adjacent pairs of carbon atoms are also carbon atoms that constitute Ring A (shared with Ring A) as described above.

In the structure of the formula (1), Q represents a divalent organic group. The divalent organic group that is Q is preferably an alkylene group, an oxaalkylene group, an arylene group, or a divalent heterocyclic group.

As the fullerene derivative having a structure represented by the formula (1), a fullerene derivative having a structure represented by the following formula (2) is preferable.

In formula (2), ring A, R ¹ , R ² , Q, C 1, C 2, C 3 and C 4 have the same meaning as the corresponding structure defined in formula (1).

A preferred embodiment of the divalent organic group Q is a group having a structure represented by the following formula (3).

In formula (3), R ^a and R ^b independently represent a hydrogen atom or an alkyl group. c represents an integer of 1 to 5. When ^a plurality of R ^a are present, R ^a may be different from each other. When two or more ^Rb exists, ^Rb may mutually differ.
The carbon number and specific examples of the alkyl group represented by R ^a and R ^b are the same as the carbon number and specific examples described above for the alkyl group represented by R ¹ and R ² .

Examples of the group having the structure represented by the formula (3) include the following groups (a) to (e).

Specific examples of the fullerene derivative of the present invention include compounds having the following structures (fullerene derivatives) (A1) to (A7).

In the compounds (A1) to (A7), ring C ₆₀ represents a C ₆₀ fullerene ring, and ring C ₇₀ represents a C ₇₀ fullerene ring.

As the fullerene derivative represented by the formula (1) and the formula (2), a fullerene derivative having a structure represented by the following formula (4) is preferable.

In the formula (4), Ring _{C 60 represents} a _{C 60} fullerene ring. C1, C2, C3 and C4 have the same definition as in the above formula (1).

<Method for producing fullerene derivative>
The fullerene derivative having the structure represented by the formula (1) has, for example, j substituents R ¹ and k substituents R ² in a C ₆₀ fullerene ring or a C ₇₀ fullerene ring (fullerene). Further, a compound in which a group capable of forming a B ¹ ring and a B ² ring is connected to a divalent organic group Q is added by an addition reaction such as a carbenoid addition reaction or a 1,3-dipole addition reaction to form a B ring. It can be manufactured by forming.

If a fullerene derivative having the structure represented by the formula (1) is produced by a production method in which the above-mentioned linked compound is added to fullerene to form a B ¹ ring and a B ² ring, 2 fullerenes are obtained in high yield. A fullerene derivative to which one ring (B ¹ ring and B ² ring) is added can be produced. According to the production method, in the production of a fullerene derivative in which two rings are added to fullerene, by-product formation of isomers that are fullerene derivatives having different numbers of ring additions or fullerene derivatives having different ring addition positions is suppressed. Can do.

The fullerene derivative having the structure represented by the formula (2) is, for example, 1,3-dipolar cycloaddition of an iminium cation generated by decarboxylation from an imine generated from a glycine derivative and a bisaldehyde compound and fullerene. It can be synthesized by reaction (Prato reaction; Accounts of Chemical Research Vol.31, 1998, pages 519-526).

Examples of the glycine derivative used in the addition reaction include N-methoxymethylglycine, N- (2- (2-methoxyethoxy) ethyl) glycine, [2- (2-methoxyethoxy) ethylamino] acetic acid, and the like. .

The amount of these glycine derivatives used is usually in the range of 0.1 mol to 10 mol, preferably in the range of 0.5 mol to 3 mol, relative to 1 mol of fullerene.

As another raw material for adding an addition group (substituent), a bisaldehyde compound includes, for example, 5- (5- (5-formylthiophen-2-yl) thiophen-2-yl) thiophene-2-carbo Examples include aldehyde (5- (5- (5-formylthiophen-2-yl) thiophen-2-yl) thiophene-2-carbaldehyde).

The amount of the bisaldehyde compound used is usually in the range of 0.1 mol to 10 mol, preferably in the range of 0.5 mol to 4 mol, relative to 1 mol of fullerene.

Usually, the above addition reaction is carried out in a solvent. When the addition reaction is carried out in a solvent, as the solvent, for example, a solvent inert to the addition reaction such as toluene, xylene, hexane, octane, chlorobenzene and the like is used. The amount of the solvent used is usually in the range of 1 to 100000 times the weight of fullerene.

The reaction step may be performed, for example, by mixing a glycine derivative, bisaldehyde, and fullerene in a solvent and reacting the mixture by heating. The reaction temperature is usually in the range of 50 ° C to 350 ° C. The reaction time is usually 30 minutes to 50 hours.

After completion of the reaction step by heating, the obtained reaction mixture is allowed to cool to room temperature, and the solvent is distilled off under reduced pressure using a rotary evaporator to obtain a solid. The obtained solid is separated and purified by silica gel flash column chromatography and preparative thin layer chromatography (silica gel thin layer chromatography). The target fullerene derivative can be obtained by the above steps.

Fullerene derivatives having a desired structure can be selectively obtained by appropriately adjusting the reaction conditions such as the amount of glycine derivative and bisaldehyde compound used as raw materials and the reaction time, and by appropriately adjusting the separation and purification conditions. .

<Composition>
The fullerene derivative of the present invention can be used as both an electron accepting compound and an electron donating compound. It is particularly preferable to use it as an electron-accepting compound. The fullerene derivative of the present invention can be suitably used as a material for an active layer formed by a coating method.
The property of the composition containing the fullerene derivative of the present invention is not particularly limited. For example, when it is set as the composition for coating used for the apply | coating method, what is necessary is just to mix the fullerene derivative of this invention with arbitrary suitable solvents, and to make it liquid (solution state).

(First composition)
As will be described in detail later, in an organic photoelectric conversion element, a layer in which an active layer contains a layer containing an electron-accepting compound (electron-accepting layer) and a layer containing an electron-donating compound (electron-donating layer) When configured as a structure, a composition (first composition) containing the fullerene derivative of the present invention as an electron-accepting compound and not containing an electron-donating compound is used as the structure of the electron-accepting layer. It can be used as a component.

(Second composition)
When the fullerene derivative of the present invention is used in a single active layer containing both an electron-accepting compound and an electron-donating compound in an organic photoelectric conversion device, the composition of the present invention (second composition). Includes the fullerene derivative of the present invention and an electron donating compound.

In addition, the first composition and the second composition may further include any other suitable component selected according to the use mode.

The electron donating compound combined with the fullerene derivative of the present invention as the electron accepting compound is preferably a polymer compound from the viewpoint of coatability. The polymer compound as used herein preferably has a polystyrene-equivalent number average molecular weight of 10 ³ or more and a polystyrene-equivalent number average molecular weight of usually 10 ⁸ or less.
Examples of the polymer compound include polyvinyl carbazole and derivatives thereof, polysilane and derivatives thereof, polysiloxane derivatives having an aromatic amine in the side chain or main chain, polyaniline and derivatives thereof, polythiophene and derivatives thereof, polypyrrole and derivatives thereof, polyphenylene Examples include vinylene and its derivatives, polythienylene vinylene and its derivatives, and polyfluorene and its derivatives.

The electron donating compound used in the organic photoelectric conversion element is selected from the group consisting of a repeating unit represented by the following formula (7) and a repeating unit represented by the following formula (8) from the viewpoint of photoelectric conversion efficiency. A polymer compound having a repeating unit having an average molecular weight in the range of about 5 × 10 ³ to 10 ⁶ is preferable, and a polymer compound having a repeating unit represented by the formula (7) is more preferable.

In the repeating unit represented by the formula (7) and the repeating unit represented by the formula (8), R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ And R ¹² independently represents a hydrogen atom, an alkyl group, an alkoxy group or an aryl group.

In the repeating unit represented by the formula (7), the carbon number and specific examples when R ³ and R ⁴ are alkyl groups include the same alkyl groups as R ¹ and R ² described and exemplified above. Can be mentioned. Examples of the carbon number and specific examples when R ³ and R ⁴ are alkoxy groups include the same alkoxy groups as R ¹ and R ² described and exemplified above. Examples of the carbon number and specific examples when R ³ and R ⁴ are aryl groups include the same aryl groups as R ¹ and R ² described and exemplified above.

In the repeating unit represented by the formula (7), from the viewpoint of photoelectric conversion efficiency, it is preferable that at least one of R ³ and R ⁴ is an alkyl group having 1 to 20 carbon atoms, It is more preferable that the number is an alkyl group having 4 to 8.
As a suitable high molecular compound comprising the repeating unit represented by the formula (7), for example, a poly (3-hexylthiophene) polymer (P3HT) in which R ³ is H and R ⁴ is C ₆ H ₁₃ is used. Can be mentioned.

In the repeating unit represented by the formula (8), the number of carbon atoms and specific examples in the case where R ⁵ to R ¹² are alkyl groups include the same alkyl groups as R ¹ and R ² described and exemplified above. Can be mentioned. Examples of the carbon number and specific examples when R ⁵ to R ¹² are alkoxy groups include the same alkoxy groups as R ¹ and R ² described and exemplified as described above. Examples of the carbon number and specific examples when R ⁵ to R ¹² are aryl groups include the same aryl groups as R ¹ and R ² described and exemplified above.

In the repeating unit represented by the formula (8), R ⁷ to R ¹² are preferably hydrogen atoms from the viewpoint of ease of monomer synthesis. From the viewpoint of photoelectric conversion efficiency, R ⁵ and R ⁶ are preferably alkyl groups having 1 to 20 carbon atoms or aryl groups having 6 to 20 carbon atoms, and have 5 carbon atoms. More preferably, it is an alkyl group having ˜8 or an aryl group having 6 to 15 carbon atoms.

The fullerene derivative, which is an electron accepting substance contained in the second composition of the present invention, is preferably 10 parts by weight to 1000 parts by weight, and 50 parts by weight to 100 parts by weight of the electron donating compound. More preferably, it is 500 parts by weight.

<Organic photoelectric conversion element>
With reference to FIG.1 and FIG.2, it demonstrates per structural example of the organic photoelectric conversion element of this invention.
FIG. 1 is a schematic cross-sectional view showing a configuration example (1) of an organic photoelectric conversion element. FIG. 2 is a schematic cross-sectional view showing a configuration example (2) of the organic photoelectric conversion element.

The organic photoelectric conversion element of the present invention has a pair of electrodes composed of an anode and a cathode, and a layer containing a fullerene derivative sandwiched between the pair of electrodes.
Of the pair of electrodes, at least the electrode on the light incident side, that is, at least one of the electrodes is a transparent or translucent electrode that transmits the incident light.

Configuration example (1)
As shown in FIG. 1, the organic photoelectric conversion element 10 of the configuration example (1) includes, for example, a pair of electrodes including a first electrode 32 that is an anode and a second electrode 34 that is a cathode, and the pair of electrodes. And an active layer 40 including a sandwiched fullerene derivative. The polarities of the first electrode 32 and the second electrode 34 may be any suitable polarity corresponding to the element structure, and the first electrode 32 may be a cathode and the second electrode 34 may be an anode.

The organic photoelectric conversion element is usually formed on a substrate. That is, the organic photoelectric conversion element 10 is provided on the main surface of the substrate 20.

The material of the substrate 20 may be any material that does not change chemically when forming an electrode and forming a layer containing an organic substance. Examples of the material of the substrate 20 include glass, plastic, polymer film, silicon, and the like.

When the substrate 20 is opaque, the second electrode 34 (that is, the electrode far from the substrate 20) provided on the opposite side of the substrate facing the first electrode 32 may be transparent or translucent. preferable.

The active layer 40 is sandwiched between the first electrode 32 and the second electrode 34. The active layer 40 is an organic layer containing, for example, the fullerene derivative of the present invention, which is an electron-accepting compound, and an electron-donating compound, and is a layer having an essential function for the photoelectric conversion function.

A first electrode 32 is provided on the main surface of the substrate 20. The active layer 40 is provided so as to cover the first electrode 32. The second electrode 34 is provided in contact with the surface of the active layer 40.

Configuration example (2)
As shown in FIG. 2, the organic photoelectric conversion element of the configuration example (2) is sandwiched between a pair of electrodes including a first electrode 32 (anode) and a second electrode 34 (cathode) and the pair of electrodes. The active layer 40 includes an electron accepting layer 44 containing the fullerene derivative of the present invention, and the electron donating layer 42 containing an electron donating compound bonded to the electron accepting layer 44. And an active layer 40.

The organic photoelectric conversion element 10 is provided on one main surface viewed from the thickness direction of the substrate 20. A first electrode 32 is provided on the main surface of the substrate 20.

The active layer 40 is held in contact with both the first electrode 32 and the second electrode 34. The active layer 40 of Structural Example 2 has a laminated structure in which, for example, an electron accepting layer 44 containing the fullerene derivative of the present invention as an electron accepting compound and an electron donating layer 42 containing an electron donating compound are joined. Has been.

The electron donating layer 42 is provided so as to cover the first electrode 32. The electron accepting layer 44 is provided so as to cover the entire surface of the electron donating layer 32. The second electrode 34 is provided in contact with the surface of the electron accepting layer 44.

In the structural examples (1) and (2), the fullerene derivative of the present invention has been described as an electron-accepting compound. However, the active layer 40 of the structural example (1) or the fullerene derivative of the present invention is used as an electron-donating compound. It can also be contained in the electron donating layer 42 of the structural example (2).

In the organic photoelectric conversion element 10 of the configuration example (1), the active layer 40 has a configuration in which the electron accepting compound and the electron donating compound are contained in a single layer, and includes more heterojunction interfaces. From the viewpoint of further improving the photoelectric conversion efficiency.

The organic photoelectric conversion element 10 may be provided with an additional layer between at least one of the first electrode 32 and the second electrode 34 and the active layer containing the fullerene derivative of the present invention. Examples of the additional layer include a charge transport layer that transports holes or electrons (a hole transport layer or an electron transport layer).

As the material constituting the charge transport layer, any conventionally known suitable material can be used. When the charge transport layer is an electron transport layer, examples of the material include 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP). In the case where the charge transport layer is a hole transport layer, polyethylenedioxythiophene (PEDOT) is exemplified as the material.

The additional layer that may be provided between the first electrode 32 and / or the second electrode 34 and the layer containing the fullerene derivative may be a buffer layer. And alkali metals such as lithium halide, halides of alkaline earth metals, oxides such as titanium oxide, and the like. When an inorganic semiconductor is used, it can be used in the form of fine particles.

Here, an example of the layer structure which the organic photoelectric conversion element of this Embodiment can take is shown below.
a) Anode / active layer / cathode b) Anode / hole transport layer / active layer / cathode c) Anode / active layer / electron transport layer / cathode d) Anode / hole transport layer / active layer / electron transport layer / cathode e) Anode / electron supply layer / electron acceptor layer / cathode f) Anode / hole transport layer / electron supply layer / electron acceptor layer / cathode g) Anode / electron supply layer / electron acceptor layer / electron Transport layer / cathode h) Anode / hole transport layer / electron supply layer / electron accepting layer / electron transport layer / cathode (herein, the symbol “/” indicates that the layers sandwiching the symbol “/” are adjacent to each other) Is shown)

The layer configuration may be any of a form in which the anode is provided on the side closer to the substrate and a form in which the cathode is provided on the side closer to the substrate.
In the organic photoelectric conversion element 10 of the structural example (1), the ratio of the fullerene derivative in the active layer 40 containing the fullerene derivative as the electron-accepting compound and the electron-donating compound is 100 parts by weight of the electron-donating compound. The amount is preferably 10 to 1000 parts by weight, more preferably 50 to 500 parts by weight.

In the organic photoelectric conversion element 10 of the structural example (1), the active layer 40 containing the fullerene derivative and the electron donating compound can be produced using a composition containing the fullerene derivative and the electron donating compound.

The layer containing the fullerene derivative used in the organic photoelectric conversion element 10 (the active layer 40, the electron donating layer 42, and the electron accepting layer 44) is preferably formed from an organic thin film containing the fullerene derivative. The thickness of the organic thin film is usually 1 nm to 100 μm, preferably 2 nm to 1000 nm, more preferably 5 nm to 500 nm, and further preferably 20 nm to 200 nm.

Examples of the electrode material in the case where the first electrode 32 and / or the second electrode 34 are electrodes formed of a transparent or translucent film (thin film) include conductive metal oxides, translucent metals, and the like. Can be mentioned. Examples of the electrode material include indium oxide, zinc oxide, tin oxide, and indium tin oxide (ITO) which is a composite thereof, conductive material made of indium zinc oxide, NESA, gold, platinum, silver, copper, etc. ITO, indium zinc oxide, and tin oxide are preferable. Further, polyaniline and derivatives thereof, polythiophene and derivatives thereof, and the like may be used as electrode materials. Examples of the method for forming the electrodes (the first electrode 32 and the second electrode 34) include a vacuum deposition method, a sputtering method, an ion plating method, a plating method, and the like.

As the electrode material of the other electrode facing the transparent or translucent electrode, a material having a small work function is preferable. An electrode including a material having a low work function may be transparent or translucent. Examples of the material include lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and the like, And alloys of two or more of them, or one or more of them and one or more of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, tin, graphite or graphite For example, a compound (interlayer compound) in which the aforementioned metal element is disposed between the layers is used. Examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, and calcium-aluminum alloy.

Next, the operation mechanism of the organic photoelectric conversion element will be described. The energy of light incident through the transparent or translucent electrode is absorbed by the electron-accepting compound and / or the electron-donating compound to generate excitons in which electrons and holes are combined. When the generated excitons move and reach the heterojunction interface where the electron-accepting compound and the electron-donating compound are adjacent (junction), the difference between the HOMO energy and the LUMO energy at the heterojunction interface causes positive and negative electrons. Charges (electrons and holes) are generated that separate from the holes and can move independently. The generated electric charge moves to the electrode and can be taken out as electric energy (current).

<Method for producing organic thin film>
The method for producing the organic thin film is not particularly limited. As a manufacturing method, for example, a film forming method using a solution (composition) containing a fullerene derivative used in the present invention and using this solution can be mentioned.

The solvent used in the solution is not particularly limited as long as it can dissolve the fullerene derivative of the present invention. Examples of the solvent include hydrocarbon solvents such as toluene, xylene, mesitylene, tetralin, decalin, bicyclohexyl, butylbenzene, sec-butylbenzene, tert-butylbenzene, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, chlorobutane, bromobutane. , Halogenated saturated hydrocarbon solvents such as chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane, bromocyclohexane, halogenated unsaturated hydrocarbon solvents such as chlorobenzene, dichlorobenzene, trichlorobenzene, tetrahydrofuran, tetrahydropyran, etc. An ether solvent is mentioned. The fullerene derivative of the present invention can usually be dissolved in the solvent in an amount of 0.1% by weight or more.

The solution may further contain the polymer compound already described. Specific examples of the solvent used in the solution include the same solvents as described above. From the viewpoint of the solubility of the polymer compound, aromatic hydrocarbon solvents are preferable, and toluene, xylene, and mesitylene are more preferable.

As a film forming method using a solution, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, Flexographic printing methods, offset printing methods, inkjet printing methods, dispenser printing methods, nozzle coating methods, capillary coating methods, and other coating methods can be used, and spin coating methods, flexographic printing methods, inkjet printing methods, and dispenser printing methods are preferred. .

An organic photoelectric conversion element generates photovoltaic power between electrodes sandwiching an active layer by allowing light such as sunlight to enter a transparent or translucent electrode, and operates as an organic thin film solar cell. be able to. It can also be used as an organic thin film solar cell module by integrating a plurality of organic thin film solar cells.

When a voltage is applied between the electrodes of the organic photoelectric conversion element and light is applied so as to pass through the transparent or translucent electrode, a photocurrent flows. Therefore, it can be operated as an organic light sensor. It can also be used as an organic image sensor by integrating a plurality of organic photosensors.

Hereinafter, examples will be shown to describe the present invention in more detail, but the present invention is not limited to these examples.

The reagents and solvents used in the synthesis (production) were either commercially available products or used after being purified by distillation in the presence of a desiccant. As C ₆₀ fullerene, a product manufactured by Frontier Carbon Co. was used. The NMR spectrum was measured using MH500 manufactured by JEOL or ECX500 manufactured by JEOL, and tetramethylsilane (TMS) was used as an internal standard. The infrared absorption spectrum was measured using FT-IR 8000 manufactured by Shimadzu Corporation. The MALDI-TOF MS spectrum was measured using an AutoFLEX-T2 manufactured by BRUKER.

<Example 1> (Synthesis of fullerene derivative A)
Compound [1]: Benzyl [2- (2-hydroxyethoxy) ethylamino] acetate was synthesized according to the following scheme.

[First step]
Bromoacetic acid (20.8 g, 150 mmol), benzyl alcohol (16.2 g, 150 mmol), para-toluenesulfonic acid (258 mg, 1.5 mmol), and benzene (300 mL) were added to a two-necked flask equipped with a Dean-Stark trap. And dehydration condensation at 120 ° C. for 24 hours. Next, the solvent was distilled off under reduced pressure using an evaporator. The residue was then purified by silica gel flash column chromatography (developing solvent; hexane: ethyl acetate = 10: 1, 5: 1) to quantitatively obtain bromoacetic acid benzyl ester (34.3 g, 150 mmol) as a yellow oil. The composition of the developing solvent is a volume ratio (the same applies to the following examples).

R _f 0.71 (hexane: ethyl acetate = 4: 1);
¹ H NMR (500 MHz, ppm, CDCl ₃ , J = Hz) δ 3.81 (s, 2H), 5.14 (s, 2H), 7.31 (s, 5H);
¹³ C NMR (125 MHz, ppm, CDCl ₃ ) δ 25.74, 67.79, 128.27, 128.48, 128.54, 134.88, 166.91;
IR (neat, cm ^-1 ) 2959, 1751, 1458, 1412, 1377, 1167, 972, 750, 698.

[Second step]
Under argon atmosphere, a solution of bromoacetic acid benzyl ester (13.7 g, 60 mmol) obtained in the first step above in dichloromethane (90 mL) was kept at 0 ° C., triethylamine (17 mL, 120 mmol) was added, and 20 minutes at 0 ° C. A mixed solution was obtained by mixing. Next, a solution of 2- (2-aminoethoxy) ethanol (12 mL, 120 mmol) in dichloromethane (40 mL) was added to the resulting mixture, and the mixture was stirred at room temperature for 4 hours to obtain a reaction solution. Next, the organic phase of the obtained reaction solution was washed with water three times, dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure using an evaporator. The obtained residue was purified by silica gel flash column chromatography (developing solvent; ethyl acetate: methanol = 1: 0 (ethyl acetate only), 10: 1, 5: 1) to give a colorless oily glycine ester compound [1 ]: Benzyl [2- (2-hydroxyethoxy) ethylamino] acetate (12.2 g, 48.0 mmol) was obtained. The yield was 80%.

R _f 0.48 (ethyl acetate: methanol = 2: 1);
¹ H NMR (500 MHz, ppm, CDCl ₃ , J = Hz) δ 2.83 (t, 2H, J = 5.1 Hz), 3.50 (s, 2H), 3.52 (t, 2H, J = 4.6 Hz), 3.58 ( t, 2H, J = 5.0 Hz), 3.65 (t, 2H, J = 4.6 Hz), 5.11 (s, 2H), 7.28-7.30 (m, 5H);
¹³ C NMR (125 MHz, ppm, CDCl ₃ ) δ 48.46, 50.25, 61.29, 66.38, 69.80, 72.23, 126.63, 128.12, 128.37, 135.30, 171.78;
IR (neat, cm ⁻¹ ) 3412, 2880, 1719, 1638, 1560, 1508, 1458, 1067, 669.

Compound [2]: [2- (2-methoxyethoxy) ethylamino] acetic acid was synthesized according to the following scheme.

[First step]
Under an argon atmosphere, a solution of compound [1]: benzyl [2- (2-hydroxyethoxy) ethylamino] acetate (6.58 g, 26 mmol) in dichloromethane (50 mL) was kept at 0 ° C. to obtain triethylamine (4.3 mL, 31 mmol). Was added. Then 4- (N, N-dimethylamino) pyridine (DMAP) (32 mg, 0.26 mmol) was added to make a mixture. The resulting mixture was stirred for 20 minutes. Next, a solution of di-tert-butyl dicarbonate (6.77 g, 31 mmol) in dichloromethane (10 mL) was added dropwise to the mixture to prepare a reaction mixture. Next, the reaction mixture was stirred at room temperature for 4 hours, poured into a triangular flask containing water, the reaction was stopped, and diethyl ether extraction was performed three times. The obtained organic phase was dried and concentrated under reduced pressure. Then, the residue was purified by silica gel flash column chromatography (developing solvent; hexane: ethyl acetate = 3: 1, 2.5: 1, 2: 1) to give colorless oily benzyl {tert-butoxycarbonyl- [2- (2-hydroxy -Ethoxy) ethyl] amino} acetate (5.83 g, 16.5 mmol) was obtained. The yield was 63%.

R _f 0.58 (ethyl acetate: methanol = 20: 1);
¹ H NMR (500 MHz, ppm, CDCl ₃ , J = Hz) δ 1.34 (d, 9H, J = 54.5 Hz), 2.19 (brs, 1H), 3.38-3.45 (m, 4H), 3.50-3.60 (m , 4H), 3.99 (d, 2H, J = 41.3 Hz), 5.09 (d, 2H, J = 4.1 Hz), 7.25-7.30 (m, 5H);
¹³ C NMR (125 MHz, ppm, CDCl ₃ ) δ 27.82, 28.05, 47.90, 48.20, 49.81, 50.39, 61.23, 66.42, 69.92, 72.12, 80.08, 127.93, 128.14, 135.25, 154.99, 155.19, 169.94, 170.07;
IR (neat, cm ^-1 ) 3449, 2934, 2872, 1751, 1701, 1458, 1400, 1367, 1252, 1143;
_{. Anal Calcd for C 18 H 27} NO 6:. C, 61.17; H, 7.70; N, 3.96 Found: C, 60.01; H, 7.75; N, 4.13.

[Second step]
Under an argon gas atmosphere, sodium hydride (1.2 g, 24.8 mmol, 50% in general oil) in tetrahydrofuran (THF) (10 mL) was added to benzyl {tert-butoxycarbonyl- [2- (2-hydroxy-ethoxy)]. Ethyl] amino} acetate (5.83 g, 16.5 mmol) in THF (20 mL) was added dropwise at 0 ° C., stirred at 0 ° C. for 20 minutes, and then iodomethane (1.6 mL, 24.8 mmol) was added at 0 ° C. The reaction mixture was prepared. The reaction mixture was then stirred at room temperature for 20 hours, and water was added while cooling with an ice bath to stop the reaction. The organic phase was dried, concentrated under reduced pressure, and purified by silica gel flash column chromatography (developing solvent; hexane: ethyl acetate = 5: 1, 3: 1) to give a colorless oily benzyl {tert -Butoxycarbonyl- [2- (2-methoxy-ethoxy) ethyl] amino} acetate (3.02 g, 8.21 mmol) was obtained. The yield was 50%.

R _f 0.54 (hexane: ethyl acetate = 1: 1);
¹ H NMR (500 MHz, ppm, CDCl ₃ , J = Hz) δ 1.34 (d, 9H, J = 51.8 Hz), 3.28 (d, 3H, J = 2.7 Hz), 3.37-3.46 (m, 6H), 3.52 (dt, 2H, J = 5.4Hz, 16.5 Hz), 4.02 (d, 2H, J = 34.8 Hz), 5.09 (d, 2H, J = 4.5 Hz), 7.24-7.30 (m, 5H);
¹³ C NMR (125 MHz, ppm, CDCl ₃ ) δ 24.93, 25.16, 44.68, 45.00, 46.70, 47.40, 55.78, 63.30, 67.22, 68.60, 76.95, 124.98, 125.14, 125.36, 132.49, 151.99, 152.31, 166.84, 166.96 ;
IR (neat, cm ^-1 ) 2880, 1751, 1701, 1560, 1458, 1400, 1366, 1117, 698, 617;
Anal. Calcd for C ₁₉ H ₂₉ NO ₆ : C, 62.11; H, 7.96; N, 3.81. Found: C, 62.15; H, 8.16; N, 3.83.

[Third step]
To a solution of benzyl {tert-butoxycarbonyl- [2- (2-methoxy-ethoxy) ethyl] amino} acetate (3.02 g, 8.21 mmol) in dichloromethane (17 mL) under an argon atmosphere was added trifluoroacetic acid (TFA) (9 0.0 mL) and stirred at room temperature for 7 hours. Subsequently, 10% sodium carbonate aqueous solution was added to adjust to pH 10, and dichloromethane extraction was performed. The obtained organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to quantitatively analyze yellow oily benzyl [2- (2-methoxy-ethoxy) ethylamino] acetate (2.18 g, 8.19 mmol). I got it.

R _f 0.32 (ethyl acetate: methanol = 20: 1);
¹ H NMR (500 MHz, ppm, CDCl ₃ , J = Hz) δ 1.99 (brs, 1H), 2.83 (t, 2H, J = 5.3 Hz), 3.38 (s, 3H), 3.50 (s, 2H), 3.54 (t, 2H, J = 4.6 Hz), 3.60-3.62 (m, 4H), 5.17 (s, 2H), 7.32-7.38 (m, 5H);
¹³ C NMR (125 MHz, ppm, CDCl ₃ ) δ 48.46, 50.66, 58.76, 66.20, 70.00, 70.44, 71.64, 128.09, 128.33, 135.44, 171.84;
IR (neat, cm ^-1 ) 3350, 2876, 1736, 1560, 1458, 1117, 1030, 698, 619;
Anal. Calcd for C ₁₄ H ₂₁ NO ₄ : C, 62.90; H, 7.92; N, 5.24. Found: C, 62.28; H, 8.20; N, 5.05.

[Fourth step]
Activated carbon (219 mg) on which 10% by weight of palladium was supported was added to a solution of benzyl [2- (2-methoxy-ethoxy) ethylamino] acetate (2.19 g, 8.19 mmol) in methanol (27 mL) at room temperature. After purging with hydrogen gas, the mixture was stirred at room temperature for 7 hours under a hydrogen atmosphere. Pd / C was removed with a glass filter with a celite pad, the celite layer was washed with methanol, and the filtrate obtained was concentrated under reduced pressure to give yellow oily compound [2]: [2- (2-methoxy Ethoxy) ethylamino] acetic acid (1.38 g, 7.78 mmol) was obtained. The yield was 95%.

¹ H NMR (500 MHz, ppm, MeOD, J = Hz) δ 3.21 (t, 2H, J = 5.1 Hz), 3.38 (s, 3H), 3.51 (s, 2H), 3.57 (t, 2H, J = 4.4 Hz), 3.65 (t, 2H, J = 4.6 Hz), 3.73 (t, 2H, J = 5.1 Hz);
¹³ C NMR (125 MHz, ppm, MeOD) δ 48.13, 50.49, 59.16, 67.08, 71.05, 72.85, 171.10;
IR (neat, cm ^-1 ) 3414, 2827, 1751, 1630, 1369, 1111, 1028, 851, 799;
_{. Anal Calcd for C 7 H 15} NO 4:. C, 47.45; H, 8.53; N, 7.90 Found: C, 46.20; H, 8.49; N, 7.43.

Compound [3]: 5- (5- (5-formylthiophen-2-yl) thiophen-2-yl) thiophene-2-carbaldehyde (5- (5- (5-formylthiophen-2-yl) thiophen-2 -yl) thiophene-2-carbaldehyde) was synthesized according to the following scheme.

Terthiophene (molecular weight 248.39) (250 mg, 1.01 mmol) was added to a 30-mL two-necked flask. After replacing the gas in the flask with argon, N, N-dimethylformamide (DMF) (162 mg, 2.21 mmol) and dichloroethane (5.0 mL) were added, and the resulting mixture was kept at 0 ° C. and phosphoryl chloride ( POCl ₃ ) (0.21 mL, 2.21 mmol) was added and stirred at 50 ° C. for 6 hours to obtain a reaction solution. After allowing to cool to room temperature, the reaction solution is quenched with 1M sodium acetate aqueous solution and extracted with dichloromethane. The organic phase is dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and silica gel column chromatography. (Developing solvent; dichloromethane: ethyl acetate = 1: 0, 10: 1, 1: 1) to purify compound [3]: 5- (5- (5-formylthiophen-2-yl) thiophene-2 -Yl) thiophene-2-carbaldehyde (5- (5- (5-formylthiophen-2-yl) thiophen-2-yl) thiophene-2-carbaldehyde; molecular weight 304.41) (38 mg, 0.125 mmol) It was. The yield was 12%. In addition, Compound [4]: Monocarbaldehyde (molecular weight 276.4) (231 mg, 0.84 mmol) which stopped reaction in the middle was also obtained. The yield was 83%.

Fullerene derivative A was synthesized according to the following scheme.

Compound [3]: 5- (5- (5-formylthiophen-2-yl) thiophen-2-yl) thiophene-2-carbaldehyde (5- (5- (5-formylthiophen-2-yl) thiophen-2 -yl) thiophene-2-carbaldehyde) (21 mg, 0.070 mmol), compound [2]: [2- (2-methoxyethoxy) ethylamino] acetic acid (71 mg, 0.40 mmol), C ₆₀ fullerene (630 mg, 0 .88 mmol) was added to a 100 mL two-necked eggplant flask, and the reaction solution dissolved in chlorobenzene (60 mL) was heated to reflux for 7 hours. The reaction solution is allowed to cool to room temperature, the solvent is distilled off under reduced pressure, and unreacted C ₆₀ fullerene is removed using silica gel column chromatography (developing solvent; carbon disulfide: ethyl acetate = 1: 0, 30: 1). The residue was purified by silica gel thin layer chromatography (developing solvent; toluene: ethyl acetate = 10: 1). Fullerene derivative A (molecular weight 1255.40) (67 mg, 0.050 mmol), which is a fullerene derivative in which two rings were added to fullerene, was obtained. The yield was 76%.

<Example 2> (Synthesis of fullerene derivative C)
Fullerene derivative (C) was synthesized according to the following scheme.
In a 100 mL two-necked flask equipped with a Dimroth condenser, C ₆₀ fullerene (216 mg, 0.30 mmol) and compound [2]: [2- (2-methoxyethoxy) ethylamino] acetic acid (89 mg, 0.50 mmol) And compound [8]: 5,5- (2,1,3-benzothiadiazole-4,7-diyl) bis-2-thiophenecarboxaldehyde (5,5- (2,1,3-Benzothiadiazole-4 , 7-diyl) bis-2-thiophenecarboxaldehyde) (71 mg, 0.20 mmol), 100 mL of chlorobenzene was added, and the mixture was heated to reflux for 3 hours. After cooling to room temperature, the solvent was removed with a rotary evaporator, and the residue was washed 5 times with methanol. Subsequently, the washed residue is subjected to silica gel flash column chromatography (developing solvent; carbon disulfide: ethyl acetate = 1: 0, 10: 1), preparative thin layer chromatography (developing solvent; carbon disulfide: ethyl acetate = 10: 1). ) To obtain 113 mg (0.09 mmol) of fullerene derivative C. Fullerene derivative C was obtained as a brown powder. The yield of fullerene derivative C was 43%.

As is clear from Examples 1 and 2, according to the method for producing a fullerene derivative of the present invention, a fullerene derivative in which two ring structures (B ring) connected to each other by a divalent organic group (Q) are added. Can be manufactured efficiently. According to the method for producing a fullerene derivative of the present invention, the addition position in the fullerene ring is limited due to the structure of the addition group or the raw material bisaldehyde compound or glycine derivative. And the formation of isomers can be effectively suppressed. Therefore, the fullerene derivative of the present invention can be obtained in an extremely high yield. Therefore, the production method of the fullerene derivative of the present invention is an extremely excellent production method, and greatly contributes to the reduction of the production cost of the applied organic photoelectric conversion element, for example.

Further, according to the method for producing a fullerene derivative of the present invention, since the yield of the target fullerene derivative is extremely high as described above, further purification by purification is easy. Therefore, the fullerene derivative manufactured by such a manufacturing method greatly contributes to further improvement of the electrical characteristics of the organic photoelectric conversion element, and consequently the photoelectric conversion efficiency.

<Comparative Example 1> (Synthesis of fullerene derivative B)
Fullerene derivative B was synthesized according to the following scheme.

Fullerene C ₆₀ (500 mg, 0.69 mmol), compound [2]: [2- (2-methoxyethoxy) ethylamino] acetic acid (369 mg, 2.08 mmol), compound in a two-necked flask (200 mL) equipped with a Dimroth condenser [5]: 2-Methoxybenzaldehyde (470 mg, 3.45 mmol) was added, chlorobenzene (100 mL) was added, and the mixture was heated to reflux for 3 hours. After allowing to cool to room temperature, the solvent was removed with a rotary evaporator, and after purification using silica gel flash column chromatography (developing solvent; toluene: ethyl acetate = 1: 0 to 10: 0), preparative thin layer chromatography (development) Solvent; carbon disulfide: ethyl acetate = 10: 1), fractionated, fullerene C ₆₀ (95 mg, 0.13 mmol), compound [6]: monoadduct (fullerene derivative C) (302 mg, 0.31 mmol) ), Compound [7]: Diadduct (fullerene derivative B) (237 mg, 0.19 mmol) as a brown powder. The yield of fullerene derivative B, which is a fullerene derivative in which two rings were added to fullerene, was 28%.

Fullerene derivative B:
IR (Neat, cm ^-1 ) 2864, 2827, 1489, 1460, 1425, 1284, 1244, 1179, 1109, 1048, 1026, 754, 729, 527;
MALDI-TOF-MS (matrix: SA) found 1222.3297 (calcd for C ₈₈ H ₄₂ N ₂ O ₆ : Exact Mass: 1222.3, Mol.Wt .: 1223.28.m / e: 1222.30 (100.0%), 1223.31 (95.9% ), 1224.31 (46.7%), 1225.31 (15.4%), 1226.32 (3.8%).
Fullerene derivative C:
¹ H NMR (500 MHz, ppm, CDCl ₃ , J = Hz) δ 2.77-2.82 (1H, m), 3.39 (3H, s), 3.61 (2H, t, J = 4.5 Hz), 3.69 (3H, s ), 3.71-3.78 (2H, m), 3.92-4.02 (2H, m), 4.27 (1H, d, J = 9.6 Hz), 5.18 (1H, d, J = 9.6 Hz), 5.73 (1H, s) , 6.85 (1H, d, J = 8.2 Hz), 7.01 (2H, t, J = 7.5 Hz), 7.20 (1H, m), 7.94 (1H, d, J = 7.8Hz); ¹³ C NMR (125 MHz , ppm, CDCl ₃ ) δ52.19, 54.71, 58.77, 67.45, 69.17, 70.49, 70.57, 71.96, 73.92, 75.24, 76.75, 110.67, 121.10, 125.42, 128.80, 129.74, 134.32, 135.79, 136.21, 136.31, 139.09, 139.17, 139.86, 139.96, 141.27, 141.42, 141.52, 141.69, 141.78, 141.88, 141.96, 142.00, 142.05, 142.27, 142.33, 142.36, 142.71, 142.76, 144.08, 144.13, 144.29, 144.77, 144.94, 144.97, 145.028, 145.97, 145.028 145.44, 145.59, 145.74, 145.81, 145.86, 145.90, 145.94, 146.25, 146.47, 146.96, 153.86, 153.91, 154.76, 156.72, 157.79;
IR (Neat, cm ^-1 ) 2864, 2827, 1489, 1460, 1425, 1284, 1244, 1179, 1109, 1048, 1026, 754, 729, 527; MALDI-TOF-MS (matrix: SA) found 971.1526 (calcd for C ₇₄ H ₂₁ NO ₃ Exact Mass: 971.1521).

<Example 3> (Production and evaluation of organic thin-film solar cell)
Regioregular poly 3-hexylthiophene (manufactured by Aldrich, lot number: 09007 KH) as an electron donor was dissolved in chlorobenzene at a concentration of 1% (weight%). Thereafter, the fullerene derivative A was mixed into the solution as an electron acceptor so as to have an equal weight with respect to the weight of the electron donor. Thereafter, 1 part by weight of silica gel (Wakogel C-300 particle size: 45 to 75 μm, manufactured by Wako Pure Chemical Industries, Ltd.) was added as an adsorbent to 100 parts by weight of the solution and stirred for 12 hours. Subsequently, it filtered with the Teflon (trademark) filter with a hole diameter of 1.0 micrometer, and produced the coating solution.

An ITO film having a thickness of 150 nm was formed on one main surface of the glass substrate by sputtering. The ITO film was subjected to surface treatment by ozone UV treatment. Next, the coating solution was applied onto the ITO film by spin coating, and baked in a vacuum at 90 ° C. for 60 minutes to obtain an active layer (film thickness of about 100 nm) of the organic thin film solar cell. Thereafter, lithium fluoride was deposited on the active layer with a thickness of 4 nm by a vacuum deposition machine, and then aluminum (Al) was deposited with a thickness of 100 nm to obtain an organic thin film solar cell. The degree of vacuum during the vapor deposition process was 1 to 9 × 10 ⁻³ Pa in all cases. Moreover, the shape of the obtained organic thin-film solar cell was a regular square of 2 mm × 2 mm. The open-circuit voltage (Voc) of the obtained organic thin-film solar cell is irradiated with constant light using a solar simulator (trade name OTENTO-SUNII: AM1.5G filter, irradiance 100 mW / cm ² , manufactured by Spectrometer Co., Ltd.). The current and voltage generated are measured and determined. The results are shown in Table 1.

<Comparative Example 2> (Production and Evaluation of Organic Thin Film Solar Cell)
An organic thin film solar cell was prepared in the same manner as in Example 3 except that the fullerene derivative A was replaced with [60] -PCBM (manufactured by Frontier Carbon Co., Ltd., trade name E100, lot number: 9B0024-A). To determine the open circuit voltage. The results are shown in Table 1.

As is clear from Table 1, the organic thin film solar cell of Example 2 containing the fullerene derivative (fullerene derivative A) of the present invention in the active layer is the same as the organic thin film solar cell of Comparative Example 2 corresponding to the prior art. In comparison, a higher open-circuit voltage was obtained.

As is clear from the above description, if the layer containing the fullerene derivative of the present invention is used as an active layer of an organic photoelectric conversion element such as an organic thin film solar cell or an organic photosensor, it has extremely important characteristics particularly from the viewpoint of photoelectric conversion efficiency. A certain open end voltage can be further increased.
Therefore, the fullerene derivative of the present invention greatly contributes to further increasing the photoelectric conversion efficiency of the organic photoelectric conversion element.

Claims (11)

1. The fullerene derivative which has a structure represented by following formula (1).
   

   

   [In Formula (1), the A ring represents a fullerene ring having 60 or more carbon atoms. The B ¹ ring and the B ² ring independently represent a heterocyclic ring having 3 to 6 carbon atoms. R ¹ and R ² independently represent a monovalent functional group. Q represents a divalent organic group and is bonded to the carbon atom of the B ¹ ring and the B ² ring. j and k each independently represents an integer of 0 to 8. When a plurality of R ¹ are present, R ¹ may be different from each other. If the R ² is plurally present, R ² to each other may be different from each other. C1, C2, C3 and C4 are carbon atoms constituting the A ring, and C1 and C2, C3 and C4 are adjacent to each other in the A ring. ]
2. The fullerene derivative of Claim 1 represented by following formula (2).
   

   

   [In Formula (2), Ring A, R ¹ , R ² , Q, C 1, C 2, C 3 and C 4 have the same definitions as in Formula (1). ]
3. The fullerene derivative according to claim 1, wherein Q has a structure represented by Formula (3).
   

   

   [In Formula (3), R ^a and R ^b independently represent a hydrogen atom or an alkyl group. c represents an integer of 1 to 5. When ^a plurality of R ^a are present, R ^a may be different from each other. When two or more ^Rb exists, ^Rb may mutually differ. ]
4. The fullerene derivative of Claim 1 represented by following formula (4).
   

   

   Wherein (4), Ring _{C 60 represents} a _{C 60} fullerene ring. C1, C2, C3 and C4 have the same definition as in the above formula (1). ]
5. A composition comprising the fullerene derivative according to claim 1 and an electron donating compound.
6. The composition according to claim 5, wherein the electron donating compound is a polymer compound.
7. A pair of electrodes consisting of an anode and a cathode;
   The organic photoelectric conversion element which has a layer containing the fullerene derivative of Claim 1 pinched | interposed between a pair of electrodes.
8. A pair of electrodes consisting of an anode and a cathode;
   The organic photoelectric conversion element which has a layer containing the composition of Claim 5 clamped between a pair of electrodes.
9. A pair of electrodes consisting of an anode and a cathode;
   An active layer sandwiched between a pair of electrodes, comprising: an electron accepting layer comprising the fullerene derivative according to claim 1; and an electron donating layer comprising an electron donating compound bonded to the electron accepting layer. An organic photoelectric conversion element having the active layer.
10. Fullerene, a glycine derivative selected from the group consisting of N-methoxymethylglycine, N- (2- (2-methoxyethoxy) ethyl) glycine and [2- (2-methoxyethoxy) ethylamino] acetic acid, and 5- ( Reacting 5- (5-formylthiophen-2-yl) thiophen-2-yl) thiophene-2-carbaldehyde with heating under reflux in a solvent;
    The method for producing a fullerene derivative according to claim 1, comprising a step of removing the solvent and separating and purifying by silica gel flash column chromatography and preparative thin layer chromatography.
11. The method for producing a fullerene derivative according to claim 10, wherein the glycine derivative is [2- (2-methoxyethoxy) ethylamino] acetic acid.

Images