Method for producing fullerene derivative, fullerene derivative, and composition

Abstract

To provide a fullerene derivative having a shallower LUMO than a bisadduct fullerene derivative, where an amount of formation of an isomer is reduced.SOLUTION: The present invention provides a method for producing a fullerene derivative, comprising a first substituent introduction step and a second substituent introduction step. In the first substituent introduction step, a first substituent, represented by A1-RL-A2 in formula (1), is introduced on a fullerene ring and, in the second substituent introduction step, a second substituent, represented by A3 in formula (2), is introduced on the fullerene ring.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for producing a fullerene derivative, a fullerene derivative, and a composition.

Background Art

[0002] In the midst of accelerating climate change due to global warming, expanding the use of renewable energy to achieve a carbon-neutral society has become an urgent issue. An organic solar cell, which is a new type of solar cell that enables the expansion of the use of renewable energy, particularly solar energy, has attracted attention. The advantages of organic solar cells include the ability to generate electricity even at low illuminance, being lightweight and flexible, and being able to be fabricated at low cost by a coating process. These characteristics enable power generation in locations where existing silicon solar cells cannot be installed, such as the walls and windows of buildings. Among organic solar cells, perovskite solar cells are attractive because of their high power generation efficiency. At the research level, a conversion efficiency of over 20%, comparable to that of single-crystalline silicon, has already been achieved. In addition, inverted perovskite solar cells are also actively being studied to achieve stability and flexibility for commercialization. In an inverted device, an organic semiconductor capable of film formation at low temperature is required as a charge transport layer material (including an electron transport layer and a hole transport layer).

[0003] In perovskite solar cells, as a material responsible for electron transport, a fullerene derivative, which is an n-type semiconductor, is a promising candidate material. Regarding the light-absorbing layer, conventionally, lead-based perovskites have been mainly used. However, aiming at improving the power conversion efficiency and reducing the environmental impact of the materials used, the use of tin-based perovskites is becoming widespread. In a solar cell using a tin-based perovskite for the light-absorbing layer, one of the factors that most affects the power conversion efficiency is the difference in the orbital energy levels between the charge transport layer and the light-absorbing layer. In lead-based perovskite solar cells, PCBM (Phenyl C61-butyric acid methyl ester), which is commercially available, has been used as a reference material for the electron transport layer. However, since tin-based perovskite solar cells have a wider bandgap than lead-based perovskite solar cells, an electron transport layer material with a shallower orbital energy level is required. Here, the required orbital energy level corresponds to the LUMO of the bisadduct (56π) of the fullerene derivative. As a fullerene bisadduct, ICBA (Indene-C60 Bisadduct) is commercially available, and ICBA has been used as a reference material for the electron transport layer in tin-based perovskite solar cells.

[0004] Here, ICBA is generally sold as a mixture of isomers and has a different isomer composition for each production lot. Since conventional ICBA contains a plurality of types of isomers, it is difficult to align the arrangement in the electron transport layer, the electron mobility is kept low, and there is a limit to the obtained current value. On the other hand, in order to reduce the amount of isomers and obtain a fullerene derivative composed of a compound having a single structure, a method of regioselectively introducing two substituents into the fullerene nucleus has been studied. By using a bisadduct having a single structure that does not contain isomers, a highly efficient electron transport layer with a higher current value than ICBA can be constructed. Specifically, the following 56π-based fullerene derivatives are known, and tin-based perovskite solar cells using these as the electron transport layer have been studied (Non-Patent Documents 1 to 3).

[0005] [Chemical formula]

[0006] Since the above fullerene derivative has a low isomer content, in the electron transport layer containing the above fullerene derivative, a high current value derived from the uniformity of the arrangement can be expressed. On the other hand, since the LUMO level is deeper than that of ICBA, the voltage value was insufficient. Therefore, in order to construct a more efficient solar cell, a fullerene derivative capable of forming an electron transport layer that can obtain a high current value and can obtain a higher voltage value than the above-mentioned bis-adduct fullerene derivative has been demanded.

[0007] Therefore, as a measure to raise the voltage value, the use of a tris-adduct fullerene derivative with a shallower LUMO than the bis-adduct fullerene derivative has been investigated (Non-Patent Documents 4 and 5). Non-Patent Documents 4 and 5 show that when synthesizing a mono-adduct fullerene derivative, a bis-adduct fullerene derivative, and a tris-adduct fullerene derivative having one specific substituent, the LUMO becomes shallower as the number of substituents increases, and the tris-adduct fullerene derivative has a shallower LUMO than the bis-adduct fullerene derivative.

Prior Art Documents

Patent Documents

[0008]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

[0009] However, in the prior arts such as Non-Patent Documents 4 and 5, there is room for improvement in the yield of fullerene derivatives of trisadducts having a specific structure (for example, the yield of the fullerene derivative of trisadduct in Non-Patent Document 5 is 10.8%). Furthermore, the fullerene derivative of trisadduct could only be obtained as a mixture of complex positional isomers. That is, although the solar cell using an electron transport layer formed by the fullerene derivative of trisadduct has a higher voltage value compared to the solar cell using an electron transport layer formed by the fullerene derivative of bisadduct, since the fullerene derivative of trisadduct can only be obtained as a mixture of multiple isomers, the current value and FF (Fill Factor) are very low, and the efficiency is low.

[0010] The present invention has been made in view of such circumstances, and provides a fullerene derivative of trisadduct having a shallower LUMO than the fullerene derivative of bisadduct, with reduced amounts of by-products such as monoadduct, bisadduct, and tetraadduct, and reduced amounts of isomers of trisadduct.

Means for Solving the Problems

[0011] According to the present invention, there is provided a method for producing a fullerene derivative, comprising a first substituent introduction step and a second substituent introduction step, in the first substituent introduction step, A in formula (1) 1 -R L -A 2 represents a first substituent introduced onto the fullerene ring in the second substituent introduction step, A in formula (2) 3 represents a second substituent introduced onto the fullerene ring, and a production method is provided.

Chemical formula

Chemical formula

[0012] As a result of intensive studies, the present inventors have found that a production method including a first substituent introduction step having a specific structure and a second substituent introduction step having a specific structure can provide a fullerene derivative of a tris adduct having a shallower LUMO than a fullerene derivative of a bis adduct, and can reduce the production amounts of by-products such as a mono adduct, a bis adduct, and a tetra adduct, and the production amount of isomers of the tris adduct, leading to the completion of the present invention.

[0013] The following are examples of various embodiments of the present invention. The embodiments shown below can be combined with each other. [1] A method for producing a fullerene derivative, comprising a first substituent introduction step and a second substituent introduction step. In the first substituent introduction step, A in formula (1) 1 -R L -A 2 The first substituent represented by is introduced onto the fullerene ring. In the second substituent introduction step, A in formula (2) 3 The second substituent represented by is introduced onto the fullerene ring.

[0014] [Chemical formula] (In formula (1), FLN represents a fullerene ring, and the fullerene ring is C60, C70, or a mixture of C60 and C70. A 1 and A 2 each represent a monocyclic structure or a polycyclic structure that may have substituents. R L represents a bond, an ether bond, or a divalent organic group.)

[0015] [Chemical formula] (In formula (2), FLN represents a fullerene ring, and the fullerene ring is C60, C70, or a mixture of C60 and C70. A 3 represents a monocyclic structure or a polycyclic structure that may have substituents.) [2] A in formula (1) 1 is represented by formula (3-1), formula (3-2), or formula (3-3).

[0016] [Chemical formula] (In formula (3-1), R 111 , R 112 , R 113 , R 114 each represent hydrogen or an organic group. In formula (3-2), R121 , R 122 , R 123 , R 124 , R 125 represents hydrogen or an organic group respectively. In formula (3-3), R 131 , R 132 , R 134 , R 135 represents hydrogen or an organic group respectively. * represents a bond that binds to R L . A in formula (1) is represented by formula (4-1), formula (4-2), or formula (4-3), 2

[0017] [Chemical formula] (In formula (4-1), R 211 , R 212 , R 213 , R 214 represents hydrogen or an organic group respectively. In formula (4-2), R 221 , R 222 , R 223 , R 224 , R 225 represents hydrogen or an organic group respectively. In formula (4-3), R 231 , R 232 , R 234 , R 235 represents hydrogen or an organic group respectively. * represents a bond that binds to R L . A in formula (2) is represented by formula (5-1), formula (5-2), or formula (5-3), which is the method for producing the fullerene derivative described in [1]. 3

[0018] [Chemical formula] (In formula (5-1), R 311 , R 312 , R 313 , R 314 , R 315 represents hydrogen or an organic group respectively. In formula (5-2), R 321 , R 322 , R 323 , R 324 , R325 , R 326 each represents hydrogen or an organic group. In formula (5-3), R 331 , R 332 , R 333 , R 334 , R 335 , R 336 each represents hydrogen or an organic group.) A method for producing a fullerene derivative according to [3][1] or [2], wherein carbon contained in A 1 and located on the fullerene ring is defined as C A1F , and carbon contained in A 2 and located on the fullerene ring is defined as C A2F , the fullerene derivative has a ring containing C A1F and C A2F . A production method A method for producing a fullerene derivative according to any one of [4][1] to [3], wherein carbon contained in A 1 and having a bond connecting to R L is defined as C A1 , and carbon contained in A 2 and having a bond connecting to R L is defined as C A2 , when carbon C A1 and carbon C A2 are either connected by a bond or separated by an element with 20 or less. A production method A method for producing a fullerene derivative according to any one of [5][1] to [4], wherein A 3 in formula (2) is represented by formula (5-1), and at least one of R 311 , R 312 , R 313 , R 314 , R 315 optionally contains an aryl group having one or more substituents. A production method [6] The production method according to any one of [1] to [5], wherein the fullerene derivative is used as an electron transport layer material for a perovskite solar cell containing tin [7] A fullerene derivative having a structure represented by formula (6)

[0019] [Chemical formula] (In formula (6), FLN represents a fullerene ring, and the fullerene ring is C60, C70, or a mixture of C60 and C70, and A 1 , A 2 , and A 3 each represent a monocyclic structure or a polycyclic structure that may have substituents, and R L represents a bond, an ether bond, or a divalent organic group.) [8] A 1 in formula (6) is represented by formula (3-1), formula (3-2), or formula (3-3),

[0020] [Chemical formula] (In formula (3-1), R 111 , R 112 , R 113 , R 114 each represent hydrogen or an organic group. In formula (3-2), R 121 , R 122 , R 123 , R 124 , R 125 each represent hydrogen or an organic group. In formula (3-3), R 131 , R 132 , R 134 , R 135 each represent hydrogen or an organic group, and * represents a bond that binds to R L .) A 2 in formula (6) is represented by formula (4-1), formula (4-2), or formula (4-3),

[0021] [Chemical formula] (In formula (4-1), R 211 , R 212 , R 213 , R 214 each represent hydrogen or an organic group. In formula (4-2), R 221 , R 222 , R 223 , R224 and R 225 each represents hydrogen or an organic group. In formula (4-3), R 231 and R 232 and R 234 and R 235 each represents hydrogen or an organic group, and * represents a bond connecting to R L .) A in formula (6) 3 is a fullerene derivative described in [7], represented by formula (5-1), formula (5-2), or formula (5-3).

[0022]

Chemical formula

[10] , [7] to [9], wherein the carbon contained in A 1 and having a bond connecting to R L is designated as CA1 as, A 2 carbon contained in, R L carbon having a bond that binds to, C A2 when taken as, carbon C A1 and carbon C A2 is a fullerene derivative that is bonded by a bond or separated by an element of 20 or less. A fullerene derivative according to any one of

[11] [7] to

[10] , wherein A in formula (6) 3 is represented by formula (5-1), R 311 , R 312 , R 313 , R 314 , R 315 Among them, at least one contains an aryl group that may have one or more substituents, a fullerene derivative.

[12] The fullerene derivative is used as an electron transport layer material for a perovskite solar cell containing tin, a fullerene derivative according to any one of [7] to

[11] .

[13] A composition containing a fullerene derivative according to any one of [7] to

[12] , wherein when the fullerene derivative contained in the composition is 100% by mass, the content of the fullerene derivative represented by formula (6) is 0.1% by mass or more, a composition.

[14] The composition according to

[13] , wherein the composition contains two or more isomers of the fullerene derivative represented by formula (6), and among the isomers of the fullerene derivative represented by formula (6), when the isomer having the highest content rate in the composition is the fullerene derivative FLN-D1, the content rate of the fullerene derivative FLN-D1 with respect to 100% by mass of the fullerene derivative represented by formula (6) contained in the composition is 50% by mass or more, a composition. [Advantages of the Invention]

[0023] According to the method for producing a fullerene derivative according to the present invention, a tris-adduct fullerene derivative having a shallower LUMO than a bis-adduct fullerene derivative, and the production amounts of by-products such as mono-adducts, bis-adducts, and tetra-adducts and the production amount of isomers of the tris-adduct can be reduced. A fullerene derivative can be obtained. Further, according to the fullerene derivative, an electron transport layer capable of obtaining a high current value and a high voltage value can be formed in a tin-based perovskite solar cell, contributing to the improvement of the efficiency of the solar cell. Furthermore, according to the production method of the present invention, since the production amounts of by-products such as mono-adducts, bis-adducts, and tetra-adducts are small, the cost and labor of purification can be reduced.

Brief Description of Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0025] Hereinafter, the present invention will be described in detail by exemplifying embodiments of the present invention. The present invention is not limited to these descriptions. Each feature of the embodiments of the present invention shown below can be combined with each other. Further, the invention is established independently for each feature.

[0026] 1. Method for Producing Fullerene Derivative The method for producing a fullerene derivative according to the present invention includes a first substituent introduction step and a second substituent introduction step.

[0027] The manufacturing method according to the present invention has a first substituent introduction step and a second substituent introduction step, and the order of the first substituent introduction step and the second substituent introduction step is not particularly defined. The second substituent introduction step may be performed after the first substituent introduction step, or the first substituent introduction step may be performed after the second substituent introduction step. As a result of intensive studies, the inventors of the present invention have provided a first substituent introduction step for introducing a relatively bulky substituent having a specific structure in the production of a trisadduct fullerene derivative, and before or after the first substituent introduction step, By providing a second substituent introduction step separately from this, in the trisadduct fullerene derivative, the probability that the positions where the three substituents are introduced become fixed positions increases, and the production of by-products such as monoadducts, bisadducts, and tetraadducts and the generation of various isomers can be suppressed, and it has been found that the production amount can be reduced, and the present invention has been completed.

[0028] When the second substituent introduction step is performed after the first substituent introduction step, the fullerene derivative after the introduction of the first substituent after the first substituent introduction step already has a relatively bulky first substituent. Therefore, in the second substituent introduction step, the position where the second substituent is introduced is determined to some extent, and the probability of obtaining a fullerene derivative having a single structure (fullerene derivative after the introduction of the first and second substituents) is improved. Further, when the first substituent introduction step is performed after the second substituent introduction step, a relatively bulky first substituent is introduced into the fullerene derivative after the introduction of the second substituent after the second substituent introduction step. Also in this case, due to the bulkiness of the first substituent, the position where the first substituent is introduced is determined to some extent, and the probability of obtaining a fullerene derivative having a specific structure (fullerene derivative after the introduction of the first and second substituents) is improved. In this specification, the fullerene derivative after the introduction of the first substituent means the fullerene derivative after the first substituent introduction step, and includes a fullerene derivative having only the first substituent and a fullerene derivative having the first substituent and the second substituent. Further, in this specification, the fullerene derivative after the introduction of the second substituent means the fullerene derivative after the second substituent introduction step, and includes a fullerene derivative having only the second substituent and a fullerene derivative having the first substituent and the second substituent.

[0029] 1.1 First Substituent Introduction Step In the production method according to the present invention, in the first substituent introduction step, A in the formula (1) 1 -R L -A 2 represents a first substituent introduced onto the fullerene ring.

Chemical formula

[0030] In the formula (1), FLN represents a fullerene ring. The fullerene ring can be one selected from C60, C70, and a mixture of C60 and C70, can be C60, C70, or a mixture of C60 and C70, can be C60 or C70, and more preferably is C60 fullerene. When it is a mixture of C60 and C70, the content of C60 is, for example, 0.001, 0.01, 0.1, 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100% by mass, and may be within the range between any two of the values exemplified herein. A 1 and A 2 each represent a monocyclic structure or a polycyclic structure which may have a substituent. In this specification, the monocyclic structure or polycyclic structure includes aliphatic, aromatic, heterocyclic, and their monocyclic and polycyclic structures.

[0031] R Lrepresents a bond, an ether bond (-O-), or a divalent organic group. In the present specification, the organic group means a group containing one or more carbon atoms (or a group formed by removing one or more hydrogen atoms from an organic compound). Examples of the divalent organic group include an alkylene group, an alkenylene group, an alkynylene group, a cycloalkylene group, an alkylene cycloalkylene group, a cycloalkylene alkylene group, an arylene group, an alkylene arylene group, an arylene alkylene group, a group formed by linking two or more of these, and a structure formed by linking these with an ether bond, a thioether bond (-S-), an amino group, an ester bond, an amide bond, etc., and at least one carbon atom contained therein may be substituted with a divalent heteroatom (for example, oxygen). R L is preferably selected from a bond, an ether bond, an alkylene group which may have a substituent and may be substituted with a divalent heteroatom (for example, oxygen), an arylene group, and a structure formed by linking these with an ether bond, a thioether bond, an amino group, an ester bond, an amide bond, etc.

[0032] A in formula (1) 1 can be represented by formula (3-1), formula (3-2), or formula (3-3). [Chemical formula]

[0033] A in formula (1) 1 can be represented by formula (3-1). In formula (3-1), R 111 , R 112 , R 113 , R 114 each represent hydrogen or an organic group.

[0034] The organic group can be a hydrocarbon group which may have one or more substituents. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkadienyl group, an aryl group, and an aralkyl group, and groups formed by linking two or more of these. R 111 、R 112 、R 113 、R 114 Preferably, each of them contains one selected from the group consisting of hydrogen, an alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, or an aryl group which may have one or more substituents. As an example, R 111 、R 112 、R 113 、R 114 can be hydrogen or an alkyl group which may have one or more substituents.

[0035] Examples of the alkyl group which may have one or more substituents include linear or branched alkyl groups which may have one or more substituents. The alkyl group can also have no substituent. The number of carbon atoms of the alkyl group can be 1 to 20, preferably 4 to 15. The number of carbon atoms of the alkyl group can be, for example, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or can be within the range between any two of the exemplified values. Examples of the alkyl group include n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, etc., and alkyl groups having a branched structure thereof.

[0036] In an aralkyl group which may have one or more substituents, the number of carbon atoms of the aralkyl group can be 4 to 12, preferably 7 to 20. The number of carbon atoms of the aralkyl group is, for example, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range between any two of the numerical values exemplified herein. Examples of the aralkyl group include benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 3-phenylpropyl group, 4-phenylbutyl group, 5-phenylpentyl group and the like.

[0037] The aryl group which may have one or more substituents can be an aryl group having no substituent or an aryl group having one or more substituents. Examples of the aryl group include phenyl, 1-naphthyl, 2-naphthyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, or 2-anthryl group, and the aryl group is preferably a phenyl group.

[0038] R 111 、R 112 、R 113 、R 114 The substituents that R

[0039] in formula (1) 1 can be represented by formula (3-2). In formula (3-2), R 121 、R 122 、R 123 、R 124 、R 125 each represent hydrogen or an organic group. The organic group can be a hydrocarbon group which may have one or more substituents. Examples of the hydrocarbon group include alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, cycloalkadienyl group, aryl group, aralkyl group, and alkoxy group, and groups in which two or more of these are linked. R121 , R 122 , R 123 , R 124 , R 125 Each of R, R, R, R, R, and R is preferably selected from the group consisting of hydrogen, an alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, an aryl group which may have one or more substituents, or an alkoxy group which may have one or more substituents (e.g., a phenoxy group). As an example, R, R, R, R, R, and R may be hydrogen, an alkyl group which may have one or more substituents, or an alkoxy group which may have one or more substituents (e.g., a phenoxy group). 121 , R 122 , R 123 , R 124 , R 125 R, R, R, R, R, and R may be hydrogen, an alkyl group which may have one or more substituents, or an alkoxy group which may have one or more substituents (e.g., a phenoxy group).

[0040] Examples of the alkyl group which may have one or more substituents include a linear or branched alkyl group which may have one or more substituents. The alkyl group may have no substituent. The number of carbon atoms of the alkyl group can be 1 to 20, preferably 4 to 15. The number of carbon atoms of the alkyl group is, for example, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range between any two of the exemplified values. Examples of the alkyl group include an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, etc., and alkyl groups having a branched structure thereof.

[0041] In an aralkyl group which may have one or more substituents, the number of carbon atoms of the aralkyl group is preferably 7 to 20. The number of carbon atoms of the aralkyl group is, for example, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range between any two of the exemplified numerical values. Examples of the aralkyl group include benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 3-phenylpropyl group, 4-phenylbutyl group, 5-phenylpentyl group and the like.

[0042] In an alkoxy group which may have one or more substituents, the number of carbon atoms of the alkoxy group can be 1 to 20. The number of carbon atoms of the alkoxy group is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range between any two of the exemplified numerical values. Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, allyloxy group, phenoxy group, cyclohexyloxy group, benzyloxy group and the like.

[0043] R 121 、R 122 、R 123 、R 124 、R 125 The substituents that R

[0044] 、R 1 、R 、R 131 、R 132 、R 134 、R 135Each represents hydrogen or an organic group. The organic group can be a hydrocarbon group which may have one or more substituents. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkadienyl group, an aryl group, an aralkyl group, and an alkoxy group (e.g., a phenoxy group), and a group formed by linking two or more of these groups. R 131 , R 132 , R 134 , R 135 Each preferably contains one selected from the group consisting of hydrogen, an alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, an aryl group which may have one or more substituents, and an alkoxy group which may have one or more substituents. As an example, R 131 can be hydrogen or an alkyl group which may have one or more substituents. Also, R 132 , R 134 , R 135 can be hydrogen, an alkyl group which may have one or more substituents, an aryl group which may have one or more substituents, or an alkoxy group which may have one or more substituents.

[0045] Examples of the alkyl group which may have one or more substituents include a linear or branched alkyl group which may have one or more substituents. The alkyl group can also have no substituent. The number of carbon atoms of the alkyl group can be 1 to 20, preferably 4 to 15. The number of carbon atoms of the alkyl group can be, for example, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or within the range between any two of the exemplified values. Examples of the alkyl group include an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, etc., and alkyl groups having a branched structure thereof.

[0046] In an aralkyl group which may have one or more substituents, the number of carbon atoms of the aralkyl group can be 4 to 12, preferably 7 to 20. The number of carbon atoms of the aralkyl group is, for example, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range between any two of the exemplified numerical values. Examples of the aralkyl group include benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 3-phenylpropyl group, 4-phenylbutyl group, 5-phenylpentyl group and the like.

[0047] In an alkoxy group which may have one or more substituents, the number of carbon atoms of the alkoxy group can be 1 to 20. The number of carbon atoms of the alkoxy group is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range between any two of the exemplified numerical values. Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, allyloxy group, phenoxy group, cyclohexyloxy group, benzyloxy group and the like.

[0048] R 131 、R 132 、R 134 、R 135 The substituent that R

[0049] 、R L 、R 、R

[0050] 2 in formula (1) can be represented by formula (4-1), formula (4-2), or formula (4-3).

Chemical formula

[0051] A in formula (1) 2 can be represented by formula (4-1). In formula (4-1), R 211 , R 212 , R 213 , R 214 each represents hydrogen or an organic group.

[0052] The organic group can be a hydrocarbon group which may have one or more substituents. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkadienyl group, an aryl group, and an aralkyl group, and a group in which two or more of these are linked. R 211 , R 212 , R 213 , R 214 each preferably contains one selected from the group consisting of hydrogen, an alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, or an aryl group which may have one or more substituents. As an example, R 211 , R 212 , R 213 , R 214 can be hydrogen or an alkyl group which may have one or more substituents.

[0053] Examples of the alkyl group which may have one or more substituents include linear or branched alkyl groups which may have one or more substituents. The alkyl group may have no substituent. The number of carbon atoms of the alkyl group can be 1 to 20, preferably 4 to 15. The number of carbon atoms of the alkyl group can be, for example, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range between any two of the exemplified values. Examples of the alkyl group include n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, etc., and alkyl groups having a branched structure thereof.

[0054] In the aralkyl group which may have one or more substituents, the number of carbon atoms of the aralkyl group can be 4 to 12, preferably 7 to 20. The number of carbon atoms of the aralkyl group can be, for example, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range between any two of the exemplified values. Examples of the aralkyl group include benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 3-phenylpropyl group, 4-phenylbutyl group, 5-phenylpentyl group, etc.

[0055] The aryl group which may have one or more substituents can be an aryl group having no substituent or an aryl group having one or more substituents. Examples of the aryl group include phenyl, 1-naphthyl, 2-naphthyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, or 2-anthryl group, and the aryl group is preferably a phenyl group.

[0056] R 211 、R 212 、R 213 、R 214Examples of the substituent which can be included are at least one selected from the group consisting of linear or branched alkyl groups having 1 to 20 carbon atoms and groups in which these alkyl groups are substituted with oxygen, sulfur, nitrogen, chlorine, fluorine and the like.

[0057] A in formula (1) 2 can be represented by formula (4-2). In formula (4-2), R 221 , R 222 , R 223 , R 224 , R 225 each represents hydrogen or an organic group. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkadienyl group, an aryl group, an aralkyl group, an alkoxy group, and a group in which two or more of these are linked. R 221 , R 222 , R 223 , R 224 , R 225 each preferably contains one selected from the group consisting of hydrogen, an alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, an aryl group which may have one or more substituents, or an alkoxy group (e.g., a phenoxy group) which may have one or more substituents. As an example, R 221 , R 222 , R 223 , R 224 , R 225 can be hydrogen, an alkyl group which may have one or more substituents, or an alkoxy group (e.g., a phenoxy group) which may have one or more substituents.

[0058] R in formula (4-2) 221 , R 222 , R 223 , R 224 , R 225An alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, an aryl group which may have one or more substituents, and a specific example of an alkoxy group which may have one or more substituents are the R in formula (3-2). 121 , R 122 , R 123 , R 124 , R 125 It can be the same as the specific examples of an alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, and an aryl group which may have one or more substituents of R in formula (3-2).

[0059] As the substituent, it is preferable to include at least one selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and a group in which these alkyl groups are substituted with oxygen, sulfur, nitrogen, chlorine, fluorine, etc.

[0060] A in formula (1) 2 can be represented by formula (4-3). In formula (4-3), R 231 , R 232 , R 234 , R 235 each represent hydrogen or an organic group. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkadienyl group, an aryl group, an aralkyl group, and an alkoxy group (e.g., a phenoxy group), and a group in which two or more of these are linked. R 231 , R 232 , R 234 , R 235 each preferably contains one selected from the group consisting of hydrogen, an alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, an aryl group which may have one or more substituents, and an alkoxy group which may have one or more substituents. As an example, R 231 can be hydrogen or an alkyl group which may have one or more substituents. Also, R 232 , R 234 , R 235It can be a hydrogen atom, an alkyl group which may have one or more substituents, an aryl group which may have one or more substituents, or an alkoxy group which may have one or more substituents.

[0061] R in formula (4-3) 231 R 232 R 234 R 235 Specific examples of the alkyl group which may have one or more substituents, the aralkyl group which may have one or more substituents, and the aryl group which may have one or more substituents among R 131 R 132 R 134 R 135 can be the same as the specific examples of the alkyl group which may have one or more substituents, the aralkyl group which may have one or more substituents, and the aryl group which may have one or more substituents among R 131 R 132 R 134 R 135 in formula (3-3).

[0062] The substituent preferably includes at least one selected from the group consisting of linear and branched alkyl groups having 1 to 20 carbon atoms, and groups in which these alkyl groups are substituted with oxygen, sulfur, nitrogen, chlorine, fluorine, etc.

[0063] * in formula (4-1), formula (4-2), and formula (4-3) represents a bond that binds to R L .

[0064] The first substituent according to one embodiment of the present invention is · A in formula (1) 1 is represented by formula (3-1), and A in formula (1) 2 is represented by formula (4-1), or · A in formula (1) 1 is represented by formula (3-2), and A in formula (1) 2 is represented by formula (4-2), or · A in formula (1) 1 is represented by formula (3-3), and A in formula (1) 2 is represented by formula (4-3), and preferably any of them.

[0065] An example of the fullerene derivative after introduction of the first substituent obtained in the first substituent introduction step is shown below. In the following, the form having only the first substituent when the first substituent introduction step is carried out first is shown as an example.

[0066]

Chemical formula

[0067] The fullerene derivative after introduction of the first substituent obtained after the first substituent introduction step is the carbon contained in A 1 which is the carbon on the fullerene ring (the carbon constituting the ring structure A 1 and constituting the fullerene ring) is designated as C A1F and when the carbon contained in A 2 which is the carbon on the fullerene ring is designated as C A2F the resulting fullerene derivative preferably has a ring containing C A1F and C A2F That is, the fullerene derivative after introduction of the first substituent preferably has a ring containing C A1F and C A2F on the fullerene ring.

[0068] The fullerene derivative after introduction of the first substituent obtained after the first substituent introduction step is the carbon contained in A 1 which has a bond connecting to R L is designated as C A1 and when the carbon contained in A 2 which has a bond connecting to R L is designated as C A2 carbon C A1 and carbon C A2 are preferably bonded by a bond or separated by an element of 20 or less. The number of elements sandwiched between carbon C A1 and carbon C A2 is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range between any two of the numerical values exemplified here. Here, carbon C A1 and carbon C A2 The number of elements sandwiched between them means the number of elements passing through in the shortest path connecting carbon C A1 and carbon C A2 Here, the elements (separated elements) sandwiched between carbon C A1 and carbon C A2 are preferably carbon and / or oxygen.

[0069] According to one embodiment of the present invention, A 1 and A 2 By introducing substituents of the bis-adduct separated by a specific distance as described above, the probability of obtaining a fullerene derivative with a more single structure is improved.

[0070] The first substituent introduction step is not particularly limited as long as the first substituent represented by A 1 -R L -A 2 in formula (1) can be introduced onto the fullerene ring. For example, the methods described by Troshin, P. A. et al., Synthetic Metals 2021, Vol. 271, p. 116632, and Imahori, H. et al., Chemical Communications 2015, Vol. 51, p. 8199 can be adopted. By reacting an amino acid compound, an aldehyde compound, and fullerene, a fullerene derivative after the introduction of the first substituent having the first substituent can be obtained. As an example, when A 1 in formula (1) is represented by formula (3-1) and A 2 in formula (1) is represented by formula (4-1), an amino acid compound having substituents corresponding to R 111 、R 112 、R 113 、R 211 、R 212 、R 213 , and an aldehyde compound having substituents corresponding to R 114 、R 214 and R L are reacted with fullerene to obtain a fullerene derivative after the introduction of the first substituent having the first substituent.

[0071] The molar ratios of the aldehyde compound, the amino acid compound, and the fullerene are not particularly limited. From the viewpoint of increasing the yield, for example, 0.1 to 10 moles of the aldehyde compound and the amino acid compound can be used per 1 mole of the fullerene, and preferably they are used in amounts of 0.5 to 3 moles.

[0072] The reaction can be carried out without a solvent or in a solvent. Examples of the solvent include carbon disulfide, chloroform, dichloroethane, toluene, xylene, chlorobenzene, dichlorobenzene, etc. Among these, chloroform, toluene, xylene, chlorobenzene, etc. are preferable. These solvents may be used by mixing them in an appropriate ratio.

[0073] The reaction temperature can be, for example, from room temperature to 150 °C, and preferably it is 80 to 120 °C. In this specification, room temperature is 15 to 30 °C. The reaction time is, for example, 1 hour to 4 days, and preferably it is 10 to 48 hours.

[0074] The obtained fullerene derivative after the introduction of the first substituent can be purified by a known purification method as necessary. The purification method will be described later.

[0075] 1.2 Second Substituent Introduction Step In the production method according to the present invention, in the second substituent introduction step, the second substituent represented by A in formula (2) 3 is introduced onto the fullerene ring.

Chemical formula

[0076] In formula (2), FLN represents a fullerene ring. The fullerene ring can be one selected from C60, C70, and a mixture of C60 and C70, can be C60, C70, or a mixture of C60 and C70, can be C60 or C70, and more preferably is C60 fullerene. When it is a mixture of C60 and C70, the content of C60 is, for example, 0.001, 0.01, 0.1, 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100% by mass, and may be within the range between any two of the values exemplified herein. A 3 represents a monocyclic structure or a polycyclic structure which may have a substituent.

[0077] A in formula (2) 3 can be represented by formula (5-1), formula (5-2), or formula (5-3).

Chemical formula

[0078] A 3 can be represented by formula (5-1). In formula (5-1), R 311 , R 312 , R 313 , R 314 , R 315 each represents hydrogen or an organic group.

[0079] The organic group can be a hydrocarbon group which may have one or more substituents. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkadienyl group, an aryl group, and an aralkyl group, and groups in which two or more of these are linked. R 311 , R 312 , R 313 , R 314 , R 315Each preferably contains one selected from the group consisting of hydrogen, an alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, or an aryl group which may have one or more substituents. As an example, R 311 R 312 R 313 R 314 R 315 can be hydrogen, an alkyl group which may have one or more substituents, or an aryl group which may have one or more substituents.

[0080] Examples of the alkyl group which may have one or more substituents include linear or branched alkyl groups which may have one or more substituents. The alkyl group can also have no substituent. The number of carbon atoms of the alkyl group can be 1 to 20, preferably 4 to 15. The number of carbon atoms of the alkyl group is, for example, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and can also be within the range between any two of the exemplified values. Examples of the alkyl group include n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, etc., and alkyl groups having a branched structure thereof.

[0081] In the aralkyl group which may have one or more substituents, the number of carbon atoms of the aralkyl group can be 4 to 12, preferably 7 to 20. The number of carbon atoms of the aralkyl group is, for example, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and can also be within the range between any two of the exemplified values. Examples of the aralkyl group include benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 3-phenylpropyl group, 4-phenylbutyl group, 5-phenylpentyl group, etc.

[0082] The aryl group which may have one or more substituents may be an aryl group having no substituent or an aryl group having one or more substituents. Examples of the aryl group include phenyl, 1-naphthyl, 2-naphthyl, 2-biphenyl, 3-biphenyl, 4-biphenyl, or 2-anthryl group, and the aryl group is preferably a phenyl group.

[0083] R 311 、R 312 、R 313 、R 314 、R 315 The substituents included in R 311 , R 312 , R 313 , R 314 , R 315 preferably include at least one selected from the group consisting of linear and branched alkyl groups having 1 to 20 carbon atoms and groups in which these alkyl groups are substituted with oxygen, sulfur, nitrogen, chlorine, fluorine, etc., and one or more of these can be included, and it can be one or two.

[0084] R 311 、R 312 、R 313 、R 314 、R 315 Examples of the alkyl group which may have one or more substituents that the substituents included in R 311 , R 312 , R 313 , R 314 , R 315 can include include linear or branched alkyl groups which may have one or more substituents. Note that the alkyl group which may have one or more substituents can be one that does not include an alkyl fluoride group. The alkyl group can also have no substituent. The number of carbon atoms of the alkyl group can be 4 to 12, and is preferably 4 to 10. The number of carbon atoms of the alkyl group is, for example, 4, 5, 6, 7, 8, 9, 10, 11, 12, and may also be within the range between any two of the numerical values exemplified here.

[0085] In formula (5-1), R 311 、R 312 、R 313 、R 314 、R 315It is preferable that at least one is an aryl group which may have one or more substituents, preferably two or more are aryl groups which may have one or more substituents, and preferably three are aryl groups which may have one or more substituents. In formula (5-1), R 311 , R 312 One of them is preferably an aryl group which may have one or more substituents, and the other is preferably hydrogen. Also, R 314 , R 315 One of them is preferably an aryl group which may have one or more substituents, and the other is preferably hydrogen. Also, R 313 is preferably an aryl group which may have one or more substituents.

[0086] A 3 can be represented by formula (5-2). In formula (5-2), R 321 , R 322 , R 323 , R 324 , R 325 , R 326 each represent hydrogen or an organic group. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkadienyl group, an aryl group, an aralkyl group, and an alkoxy group, and groups formed by linking two or more of these. R 321 , R 322 , R 323 , R 324 , R 325 , R 326 each preferably contains one selected from the group consisting of hydrogen, an alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, an aryl group which may have one or more substituents, or an alkoxy group which may have one or more substituents (for example, a phenoxy group). As an example, R 321 , R 322 , R 323 , R 324 , R 325 , R326 may be composed of hydrogen, an alkyl group which may have one or more substituents, and an alkoxy group which may have one or more substituents (for example, a phenoxy group).

[0087] R in formula (5-2) 321 , R 322 , R 323 , R 324 , R 325 , R 326 Specific examples of the alkyl group which may have one or more substituents, the aralkyl group which may have one or more substituents, and the aryl group which may have one or more substituents of R 121 , R 122 , R 123 , R 124 , R 125 in formula (3-2) may be the same as the specific examples of the alkyl group which may have one or more substituents, the aralkyl group which may have one or more substituents, and the aryl group which may have one or more substituents of R

[0088] The substituent preferably includes at least one selected from the group consisting of linear and branched alkyl groups having 1 to 20 carbon atoms and groups in which these alkyl groups are substituted with oxygen, sulfur, nitrogen, chlorine, fluorine, etc.

[0089] A 3 may be represented by formula (5-3). In formula (5-3), R 331 , R 332 , R 333 , R 334 , R 335 , R 336 each represents hydrogen or an organic group. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkadienyl group, an aryl group, an aralkyl group, an alkoxy group (for example, a phenoxy group), and a group in which two or more of these are linked. R 331 , R 332 , R 333 , R 334 , R335 , R 336 is preferably selected from the group consisting of hydrogen, an alkyl group which may have one or more substituents, an aralkyl group which may have one or more substituents, an aryl group which may have one or more substituents, and an alkoxy group which may have one or more substituents. As an example, R 131 can be hydrogen or an alkyl group which may have one or more substituents. Also, R 132 , R 134 , R 135 can be hydrogen or an alkyl group which may have one or more substituents, an aryl group which may have one or more substituents, or an alkoxy group which may have one or more substituents.

[0090] For R in formula (5-3) 331 , R 332 , R 333 , R 334 , R 335 , R 336 , specific examples of the alkyl group which may have one or more substituents, the aralkyl group which may have one or more substituents, and the aryl group which may have one or more substituents of R 131 , R 132 , R 134 , R 135 in formula (3-3) can be the same as the specific examples of the alkyl group which may have one or more substituents, the aralkyl group which may have one or more substituents, and the aryl group which may have one or more substituents of R

[0091] The substituent preferably includes at least one selected from the group consisting of a linear or branched alkyl group having 1 to 20 carbon atoms and a group in which these alkyl groups are substituted with oxygen, sulfur, nitrogen, chlorine, fluorine, etc.

[0092] The second substituent introduction step is not particularly limited as long as the second substituent represented by A 3 in formula (2) can be introduced onto the fullerene ring. For example, the method described in WO2023 / 100719 can be adopted. Specifically, an amino acid compound, an aldehyde compound, and fullerene are reacted to obtain a fullerene derivative after introduction of a second substituent having a second substituent. As an example, A in formula (2) 3 When introducing the second substituent represented by formula (5-1), R 311 and R 312 and R 313 an amino acid compound having substituents corresponding to and R 314 and R 315 an aldehyde compound having substituents corresponding to and fullerene are reacted to obtain a fullerene derivative after introduction of a second substituent having a second substituent.

[0093] The molar ratio of the aldehyde compound, the amino acid compound, and fullerene is not particularly limited. From the viewpoint of increasing the yield, for example, 0.1 to 10 moles of the aldehyde compound and the amino acid compound can be used per 1 mole of fullerene, and preferably 0.5 to 2 moles are used.

[0094] The reaction can be carried out without a solvent or in a solvent. Examples of the solvent include carbon disulfide, chloroform, dichloroethane, toluene, xylene, chlorobenzene, dichlorobenzene, etc. Among these, chloroform, toluene, xylene, chlorobenzene, etc. are preferable. These solvents may be used by mixing them in an appropriate ratio.

[0095] The reaction temperature can be, for example, room temperature to 150 °C, preferably 80 to 120 °C. In this specification, room temperature is 15 to 30 °C. The reaction time is, for example, 1 hour to 4 days, preferably 10 to 48 hours.

[0096] The obtained fullerene derivative after introduction of the second substituent can be purified by a known purification method as necessary. The purification method will be described later.

[0097] 1.3 Purification step The manufacturing method according to an embodiment of the present invention may have a purification step of purifying the obtained reaction solution. As an example, the obtained compound can be purified by silica gel column chromatography. As the developing solvent, a heptane-toluene solvent can be used. As an example, a solvent containing 1 to 20 parts of heptane with respect to 1 part of toluene can be used to extract the target fullerene derivative of the tris adduct. Specifically, the tris adduct fullerene derivative can be extracted with a solvent containing, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 parts of heptane with respect to 1 part of toluene, and the ratio of heptane may be within the range between any two of the values exemplified here.

[0098] According to the manufacturing method according to an embodiment of the present invention, a fullerene derivative of the tris adduct can be obtained in a higher yield than the conventional manufacturing method. That is, the amount of by-products such as mono adduct, bis adduct, and tetra adduct can be reduced. According to the manufacturing method according to an embodiment of the present invention, when the fullerene derivative contained in the reaction solution obtained after the first substituent introduction step and the second substituent introduction step is taken as 100% by mass, the content of the target fullerene derivative of the tris adduct can be 0.1% by mass or more. The content of the target fullerene derivative of the tris adduct can be, for example, 0.1, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80% by mass, and may be within the range between any two of the values exemplified here.

[0099] After the first substituent introduction step and the second substituent introduction step, the resulting reaction solution can contain two or more isomers of the fullerene derivative of the trisadduct. Among the isomers of the fullerene derivative of the trisadduct, when the isomer with the highest content rate in the reaction solution is defined as fullerene derivative FLN-D1, the content rate of fullerene derivative FLN-D1 with respect to the total 100% by mass of the isomers of the fullerene derivative of the trisadduct contained in the reaction solution can be 50% by mass or more. The content rate of fullerene derivative FLN-D1 is, for example, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100% by mass, and may also be within the range between any two of the numerical values exemplified here. The fullerene derivative according to one embodiment of the present invention is a trisadduct fullerene derivative having a shallower LUMO than the bisadduct fullerene derivative and having a reduced amount of isomer generation. Therefore, in a tin-based perovskite solar cell, an electron transport layer capable of obtaining a high current value and a high voltage value can be formed, contributing to the high efficiency of the solar cell. In addition, since the amount of by-products such as monoadduct, bisadduct, and tetraadduct is small, the cost and labor of purification can be reduced. The fullerene derivative according to one embodiment of the present invention is suitably used as a material for an electron transport layer for a perovskite solar cell containing tin.

[0100] 2. Fullerene Derivative The fullerene derivative according to one embodiment of the present invention can be obtained by the above production method. The fullerene derivative according to one embodiment of the present invention has a structure represented by formula (6). The fullerene derivative according to one embodiment of the present invention has a shallower LUMO than the bisadduct fullerene derivative and can form an electron transport layer capable of obtaining a high voltage value, contributing to the high efficiency of the solar cell. In addition, since the fullerene derivative according to one embodiment of the present invention has two of the trisadducts as relatively bulky substituents, a fullerene derivative having a specific structure can be obtained more easily at a higher yield than in the past.

[0101] [Chemical formula]

[0102] In formula (6), FLN represents a fullerene ring. The fullerene ring can be one selected from C60, C70, and a mixture of C60 and C70, can be C60, C70, or a mixture of C60 and C70, can be C60 or C70, and more preferably is C60 fullerene. When it is a mixture of C60 and C70, the content of C60 is, for example, 0.001, 0.01, 0.1, 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100% by mass, and may be within the range between any two of the exemplified values. A 1 , A 2 , and A 3 each represent a monocyclic structure or a polycyclic structure which may have substituents. In the present specification, the monocyclic structure or polycyclic structure includes aliphatic, aromatic, heterocyclic, and their monocyclic and polycyclic structures.

[0103] R L represents a bond, an ether bond, or a divalent organic group. Also, in the present specification, the organic group means a group containing one or more carbon atoms (or a group formed by removing one or more hydrogen atoms from an organic compound). Examples of the divalent organic group include an alkylene group, an alkenylene group, an alkynylene group, a cycloalkylene group, an alkylene cycloalkylene group, a cycloalkylene alkylene group, an arylene group, an alkylene arylene group, an arylene alkylene group, and a group formed by linking two or more of these, and a structure in which these are linked by an ether bond, a thioether bond, an amino group, an ester bond, an amide bond, etc., and at least one carbon atom contained therein may be substituted with a divalent heteroatom (for example, oxygen). R Lis preferably selected from a linking group, an ether bond, an alkylene group which may have a substituent and may be substituted with a divalent heteroatom (such as oxygen), an arylene group, and a structure in which these are linked by an ether bond, a thioether bond, an amino group, an ester bond, an amide bond, or the like.

[0104] A in formula (6) 1 can be represented by formula (3-1), formula (3-2), or formula (3-3), and formula (3-1), formula (3-2), or formula (3-3) is as described above. Also, A in formula (6) 2 is represented by formula (4-1), formula (4-2), or formula (4-3), and formula (4-1), formula (4-2), or formula (4-3) is as described above. Also, A in formula (6) 3 is represented by formula (5-1), formula (5-2), or formula (5-3), and formula (5-1), formula (5-2), or formula (5-3) is as described above.

[0105] The fullerene derivative according to one embodiment of the present invention is preferably any of the following. · A in formula (6) 1 is represented by formula (3-1), and A in formula (1) 2 is represented by formula (4-1) · A in formula (6) 1 is represented by formula (3-2), and A in formula (1) 2 is represented by formula (4-2) · A in formula (6) 1 is represented by formula (3-3), and A in formula (1) 2 is represented by formula (4-3) Furthermore, the fullerene derivative according to one embodiment of the present invention is more preferably any of the following. · A in formula (6) 1 is represented by formula (3-1), A in formula (6) 2 is represented by formula (4-1), and A in formula (6) 3 is represented by formula (5-1) · A in formula (6) 1is represented by formula (3-2), and A in formula (6) 2 is represented by formula (4-2), and A in formula (6) 3 is represented by formula (5-1) · A in formula (6) 1 is represented by formula (3-3), and A in formula (6) 2 is represented by formula (4-3), and A in formula (6) 3 is represented by formula (5-1) · A in formula (6) 1 is represented by formula (3-1), and A in formula (6) 2 is represented by formula (4-1), and A in formula (6) 3 is represented by formula (5-3)

[0106] The fullerene derivative according to the present invention is A 1 The carbon contained in, and being a carbon on the fullerene ring, is designated as C A1F and A 2 The carbon contained in, and being a carbon on the fullerene ring, is designated as C A2F When designated as C A1F and C A2F it is preferable that the fullerene derivative has a ring containing C A1F and C A2F That is, it is preferable that the fullerene derivative after introduction of the first substituent has a ring containing C

[0107] The fullerene derivative according to the present invention is A 1 The carbon contained in, and having a bond that binds to R L is designated as C A1 and A 2 The carbon contained in, and having a bond that binds to R L is designated as C A2 When designated as carbon C A1 and carbon C A2 it is preferable that carbon C A1 and carbon C A2The number of elements sandwiched is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range between any two of the numerical values exemplified herein. Here, carbon C A1 and carbon C A2 The number of elements sandwiched between refers to the number of elements passed through in the shortest path connecting carbon C A1 and carbon C A2 Here, the elements (separated elements) sandwiched between carbon C A1 and carbon C A2 are preferably carbon and / or oxygen.

[0108] According to one embodiment of the present invention, A 1 and A 2 By introducing substituents of the bisadduct separated by a specific distance as described above, the probability of obtaining a fullerene derivative with a more single structure is improved.

[0109] In formula (5-1), R 311 , R 312 , R 313 , R 314 , R 315 are preferably such that at least one is an aryl group which may have one or more substituents, more preferably two or more are aryl groups which may have one or more substituents, and most preferably three are aryl groups which may have one or more substituents. In formula (5-1), it is preferable that either one of R 311 , R 312 is an aryl group which may have one or more substituents and the other is hydrogen. Also, it is preferable that either one of R 314 , R 315 is an aryl group which may have one or more substituents and the other is hydrogen. Further, it is preferable that R 313 is an aryl group which may have one or more substituents.

[0110] In formula (5-1), R 311 , R 312, R 313 , R 314 , R 315 It is preferable that at least one of them contains at least one of an aryl group having an electron-donating group at the meta-position and an aryl group having an electron-withdrawing group at the ortho-position and / or para-position. Also, R 311 , R 312 , R 313 , R 314 , R 315 It is preferable that at least one of them is an aryl group having an electron-donating group at the meta-position, and at least one of R 311 , R 312 , R 313 , R 314 , R 315 may be an aryl group having an electron-withdrawing group at the ortho-position and / or para-position.

[0111] Examples of the electron-donating group that can be present at the meta-position include an alkyl group which may have one or more substituents, and an aralkyl group, and it is preferably an alkyl group which may have one or more substituents. Examples of the alkyl group which may have one or more substituents include a linear or branched alkyl group which may have one or more substituents. Note that the alkyl group which may have one or more substituents can be one that does not contain a fluorinated alkyl group. The number of carbon atoms of the alkyl group can be 4 to 12, and is preferably 4 to 10. The number of carbon atoms of the alkyl group is, for example, 4, 5, 6, 7, 8, 9, 10, 11, 12, and may also be within the range between any two of the values exemplified here. The alkyl group can also be one that does not have a substituent.

[0112] Examples of the electron-withdrawing group that may be present at the ortho position and / or para position include a fluorine atom and an alkyl fluoride group. The alkyl fluoride group can be a fluoroalkyl group in which the alkyl group is substituted with one or more fluorine atoms. The alkyl fluoride group may have a substituent other than a fluorine atom. The alkyl fluoride group can also be an alkyl group having no substituent other than a fluorine atom. The alkyl fluoride group is preferably a perfluoroalkyl group in which all hydrogen atoms in the alkyl group are substituted with fluorine atoms. The number of carbon atoms of the alkyl fluoride group is preferably 1 or 2. Preferred examples of the alkyl fluoride group include a monofluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a monofluoroethyl group, a difluoroethyl group, a trifluoroethyl group, a tetrafluoroethyl group, and a pentafluoroethyl group. More preferred are a trifluoromethyl group and a pentafluoroethyl group, and even more preferred is a trifluoromethyl group. Note that the fullerene derivative according to one embodiment of the present invention can have one fullerene ring in the fullerene derivative and can have no two or more fullerene rings. The fullerene derivative according to one embodiment of the present invention can be one that does not contain dimers and oligomers.

[0113] The fullerene derivative according to one embodiment of the present invention is a tris-adduct fullerene derivative having a shallower LUMO than a bis-adduct fullerene derivative, and the production amounts of by-products such as mono-adduct, bis-adduct, and tetra-adduct and the production amount of isomers of the tris-adduct are likely to be reduced. Therefore, in a tin-based perovskite solar cell, an electron transport layer capable of obtaining a high current value and a high voltage value can be formed, contributing to the high efficiency of the solar cell. In addition, since the production amounts of by-products such as mono-adduct, bis-adduct, and tetra-adduct are small, the cost and labor of purification can be reduced. The fullerene derivative according to one embodiment of the present invention is suitably used as a material for an electron transport layer for a perovskite solar cell containing tin.

[0114] The fullerene derivative according to one embodiment of the present invention has the above structure, and thus has a LUMO level shallower than that of conventional ICBA or PCBM. It is preferable that the value of the LUMO level of the fullerene derivative according to one embodiment of the present invention exceeds -3.73 eV. The value of the LUMO level can be, for example, -3.73, -3.72, -3.71, -3.7, -3.69, -3.68, -3.67, -3.66, -3.65, -3.64, -3.63, -3.62, -3.61, -3.6, -3.59, -3.58, -3.57, -3.56, -3.55, -3.54, -3.53, -3.52, -3.51, -3.50, -3.45, -3.40 eV, and may be within the range between any two of the values exemplified here. The LUMO level can be measured by the method described in Karakawa et al., Journal of Materials Chemistry A, 2014, Vol. 2, p. 20889.

[0115] 3. Composition The composition according to one embodiment of the present invention contains the above fullerene derivative. In the above production method, the reaction solution after the first substituent introduction step and the second substituent introduction step can be used as the composition according to one embodiment of the present invention, or the extract obtained through the further production step can also be used as the composition according to one embodiment of the present invention.

[0116] When the fullerene derivative contained in the composition according to one embodiment of the present invention is 100% by mass, it is preferable that the content of the fullerene derivative represented by formula (6) is 0.1% by mass or more. The content of the fullerene derivative represented by formula (6) can be, for example, 0.1, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80% by mass, and may be within the range between any two of the values exemplified here.

[0117] The composition can contain two or more isomers of the fullerene derivative represented by formula (6). When the isomer of the fullerene derivative represented by the formula (6) with the highest content rate in the composition is defined as the fullerene derivative FLN-D1, it is preferable that the content rate of the fullerene derivative FLN-D1 with respect to 100% by mass of the fullerene derivative represented by the formula (6) contained in the composition is 50% by mass or more. The content rate of the fullerene derivative FLN-D1 is, for example, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100% by mass, and it may also be within the range between any two of the numerical values exemplified herein. The fullerene derivative according to one embodiment of the present invention is a tris-adduct fullerene derivative having a shallower LUMO than a bis-adduct fullerene derivative and having a reduced amount of isomers generated. Therefore, in a tin-based perovskite solar cell, an electron transport layer capable of obtaining a high current value and a high voltage value can be formed, contributing to the high efficiency of the solar cell. Also, The composition according to one embodiment of the present invention is suitably used as a material for an electron transport layer for a perovskite solar cell containing tin.

[0118] The electron transport layer according to one embodiment of the present invention contains the above fullerene derivative or composition. The perovskite solar cell according to one embodiment of the present invention contains the above electron transport layer material. The perovskite solar cell according to one embodiment of the present invention includes an electron transport layer containing the above fullerene derivative or composition, so that a high current value can be obtained and a high voltage value can be obtained.

Example

[0119] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not construed as being limited thereto.

[0120] <Example 1> Compound 1 was obtained based on the method described by Troshin, P. A. et al. in Synthetic Metals, 2021, Vol. 271, p. 116632. A 20 mL solution of dichlorobenzene containing Compound 1 (100 mg, 0.1 mmol), 2-Phenyl-N-(3-octylphenyl)glycine (136 mg, 0.4 mmol), and 1 mL of benzaldehyde was heated and stirred at 170 °C for 24 hours. After distilling off the solvent under reduced pressure, the product was purified by silica gel column chromatography. The raw material was obtained with heptane:toluene = 5:1, the tris-form was obtained with heptane:toluene = 3:1, and the tetra-form was obtained with heptane:toluene = 1:1. In each example, the structure of the product was determined by mass spectrometry (MALDI-TOFMS). The mass spectra of the tris-form and tetra-form are shown in Figure 1.

[0121] [Chemical formula]

[0122] · Raw material (Compound 1) 37 mg, 38% · Tris-form 75 mg, 55%, · Tetra-form 8 mg, 4%, were obtained. The tris-form is represented by the following formula. In the analysis by MALDI-TOFMS, C 108 H 51 N (M+1), Calcd 1362.6, Found 1362.3. (Hereinafter, Calcd indicates the calculated molecular weight, and Found indicates the molecular weight detected as a result of the analysis.) [Chemical formula]

[0123] The tetra-form is represented by the following formula. In the analysis by MALDI-TOFMS, 8 mg, 4%, C 136 H 83 N2, Calcd 1745.1, Found 1745.5.

[0124] [Chemical formula]

[0125] <Example 2 Based on the method described by Imahori, H. et al. in Chemical Communications 2015, Vol. 51, p. 8199, Compound 2 was obtained. A solution of Compound 2 (113 mg, 0.1 mmol), 2-Phenyl-N-(3-octylphenyl)glycine (136 mg, 0.4 mmol), and 1 mL of benzaldehyde in 10 mL of dichlorobenzene was heated with stirring at 150 °C for 72 hours. After the solvent was distilled off under reduced pressure, the product was purified by silica gel column chromatography. The starting materials were obtained with heptane:toluene = 5:1, and the tris product was obtained with heptane:toluene = 3:1. The mass spectrum of the tris product is shown in Figure 2.

Chemical formula

[0126] · Starting material 11 mg, 10% · Tris product 104 mg, 64% were obtained. The tris product is represented by the following formula. In the analysis by MALDI-TOFMS, C 122 H 92 N3 (M-H), Calcd 1600.1, Found 1600.6.

Chemical formula

[0127] <Example 3 Compound 2 was obtained based on the method described in Chemical Communications, 2015, Vol. 51, p. 8199 by Imahori, H. et al. A 30 mL solution of compound 2 (113 mg, 0.1 mmol), o-dibromoxylene (32 mg, 0.12 mmol), potassium iodide (116 mg, 1 mmol), and 18-crown-6 (1.0 g, 3.8 mmol) in dichlorobenzene was heated and stirred at 120 °C for 15 hours. The reaction solution was transferred to a separatory funnel, washed three times with 10 mL of 1N NaOH, washed with water, dehydrated, and then the solvent was distilled off under reduced pressure. The product was purified by silica gel column chromatography. The raw material was obtained with heptane:toluene = 5:1, the tris-form was obtained with heptane:toluene = 2:1, and the tetra-form was obtained with heptane:toluene = 1:1. The mass spectrum of the tris-form is shown in Figure 3.

[0128] JPEG2025104091000026.jpg69155

[0129] · 22 mg of raw material, 25% · 39 mg of tris-form, 40%, · 14 mg of tetra-form, 12%, were obtained. The tris-form is represented by the following formula. In the analysis by MALDI-TOFMS, C 102 H 68 N2, Calcd 1321.6, Found 1321.2.

Chemical formula

[0130] The tetra-form is represented by the following formula. The tetra-form is represented by the following formula. In the analysis by MALDI-TOFMS, C 110 H 76 N2, Calcd 1425.8, Found 1426.1.

Chemical formula

[0131] <Example 4> Based on the method described in WO2023 / 100719A1, Compound 3 was obtained. A 30 mL solution of Compound 3 (258 mg, 0.22 mmol), N-dodecylglycine (160 mg, 0.66 mmol), and o-phtalaldehyde (35 mg, 0.26 mmol) in dichlorobenzene was heated and stirred at 120 °C for 15 hours. After distilling off the solvent under reduced pressure, the product was purified by silica gel column chromatography. The raw material was obtained with heptane:toluene = 20:1, the fullerene dimer with heptane:toluene = 5:1, and the trisomer with heptane:toluene = 2:1. The mass spectrum of the trisomer is shown in Figure 4. [Chemical formula]

[0132] · Raw material 19 mg, 7% · Trisomer 198 mg, 54% · Fullerene dimer 122 mg, 21% were obtained. The trisomer is represented by the following formula. In the analysis by MALDI-TOFMS, it was C 123 H 92 F3N3, Calcd 1669.1, Found 1669.5. [Chemical formula]

[0133] The fullerene dimer is represented by the following formula. In the analysis by MALDI-TOFMS, it was C 212 H 124 N4F6 (M+1), Calcd 2842.3, Found 2842.6. In all the examples shown above, a fullerene derivative of tris-adduct with a shallower LUMO level than the conventional fullerene derivative of bis-adduct could be obtained. Also, in each example, the yield of the fullerene derivative of tris-adduct was significantly higher compared to the prior art.

Claims

1. A method for producing a fullerene derivative, comprising a first substituent introduction step and a second substituent introduction step, In the first substituent introduction step, A in formula (1) １ -R Ｌ -A ２ is introduced as the first substituent on the fullerene ring. In the second substituent introduction step, a second substituent represented by A in formula (2) is introduced onto the fullerene ring, the production method. ３ ​ 【Chemical 1】 (In formula (1), FLN represents a fullerene ring, The fullerene ring is C60, C70, or a mixture of C60 and C70, A １ and A ２ each represent a monocyclic or polycyclic structure which may optionally have a substituent, R Ｌ represents a linking group, an ether bond or a divalent organic group.) [Chemical Formula 2] (In formula (2), FLN represents a fullerene ring, The fullerene ring is C60, C70, or a mixture of C60 and C70, A ３ represents a monocyclic structure or a polycyclic structure which may have substituents.)

2. A in formula (1) １ is represented by formula (3-1), formula (3-2), or formula (3-3), [Chemical Formula 3] (In formula (3-1), R １１１ , R １１２ , R １１３ , R １１４ each represents hydrogen or an organic group. In formula (3-2), R １２１ , R １２２ , R １２３ , R １２４ , R １２５ each represents hydrogen or an organic group. In formula (3-3), R １３１ , R １３２ , R １３４ , R １３５ each represents hydrogen or an organic group, and * represents a bond that binds to R Ｌ . ) A in formula (1) ２ is represented by formula (4-1), formula (4-2), or formula (4-3), [Chemical Formula 4] (In formula (4-1), R ２１１ , R ２１２ , R ２１３ , R ２１４ each represents hydrogen or an organic group. In formula (4-2), R ２２１ , R ２２２ , R ２２３ , R ２２４ , R ２２５ each represents hydrogen or an organic group. In formula (4-3), R ２３１ , R ２３２ , R ２３４ , R ２３５ each represents hydrogen or an organic group, and * represents a bond that binds to R Ｌ .) A in formula (2) ３ is the manufacturing method according to claim 1, represented by formula (5-1), formula (5-2), or formula (5-3). 【Chemical Formula 5】 (In formula (5-1), R ３１１ , R ３１２ , R ３１３ , R ３１４ , R ３１５ each represents hydrogen or an organic group. In formula (5-2), R ３２１ , R ３２２ , R ３２３ , R ３２４ , R ３２５ , R ３２６ each represents hydrogen or an organic group. In formula (5-3), R ３３１ , R ３３２ , R ３３３ , R ３３４ , R ３３５ , R ３３６ each represents hydrogen or an organic group.)

3. A method for producing a fullerene derivative according to claim 1 or claim 2, A １ The carbon contained in １ and located on the fullerene ring is designated as C Ａ１Ｆ and A ２ carbon contained in A, with carbon on the fullerene ring designated as C Ａ２Ｆ when... The fullerene ring has a ring containing C Ａ１Ｆ and C Ａ２Ｆ Production method.

4. A method for producing a fullerene derivative according to claim 1 or claim 2, A １ The carbon contained in Ｌ and having a bond bonded to R is C Ａ１ and A ２ The carbon contained in, which has a bond bonded to R Ｌ is defined as C when it has a bond bonded to R Ａ２ When defined as such Carbon C Ａ１ and carbon C Ａ２ is a manufacturing method in which they are bonded by a bond or separated by an element of 20 or less.

5. The method for producing a fullerene derivative according to claim 1 or claim 2, wherein A in formula (2) ３ is represented by formula (5-1), and R ３１１ , R ３１２ , R ３１３ , R ３１４ , R ３１５ wherein at least one of them contains an aryl group which may have one or more substituents.

6. The method according to claim 1 or claim 2, wherein the fullerene derivative is used as an electron transport layer material for a perovskite solar cell containing tin.

7. A fullerene derivative having a structure represented by formula (6). 【Chemical Formula 6】 (In formula (6), FLN represents a fullerene ring, The fullerene ring is C60, C70, or a mixture of C60 and C70, A １ 、 A ２ 、 and A ３ each represent a monocyclic structure or a polycyclic structure which may each have a substituent. R Ｌ represents a linking group, an ether bond or a divalent organic group.)

8. A in formula (6) １ is represented by formula (3-1), formula (3-2), or formula (3-3), 【Chemical Formula 3】 (In formula (3-1), R １１１ , R １１２ , R １１３ , R １１４ each represents hydrogen or an organic group. In formula (3-2), R １２１ , R １２２ , R １２３ , R １２４ , R １２５ each represents hydrogen or an organic group. In formula (3-3), R １３１ , R １３２ , R １３４ , R １３５ each represents hydrogen or an organic group, and * represents a bond that binds to R Ｌ . ) A in formula (6) ２ is represented by formula (4-1), formula (4-2), or formula (4-3), 【Chemical 4】 (In formula (4-1), R ２１１ , R ２１２ , R ２１３ , R ２１４ each represents hydrogen or an organic group. In formula (4-2), R ２２１ , R ２２２ , R ２２３ , R ２２４ , R ２２５ each represents hydrogen or an organic group. In formula (4-3), R ２３１ , R ２３２ , R ２３４ , R ２３５ each represents hydrogen or an organic group, and * represents a bond that binds to R Ｌ . ) A in formula (6) ３ is the fullerene derivative according to claim 7, represented by formula (5-1), formula (5-2), or formula (5-3). 【Chemical Formula 5】 (In formula (5-1), R ３１１ , R ３１２ , R ３１３ , R ３１４ , R ３１５ each represents hydrogen or an organic group. In formula (5-2), R ３２１ , R ３２２ , R ３２３ , R ３２４ , R ３２５ , R ３２６ each represents hydrogen or an organic group. In formula (5-3), R ３３１ , R ３３２ , R ３３３ , R ３３４ , R ３３５ , R ３３６ each represents hydrogen or an organic group.)

9. A fullerene derivative according to claim 7 or claim 8, A １ carbon contained in A, where the carbon on the fullerene ring is designated as C Ａ１Ｆ and A ２ The carbon contained in ２ , which is on the fullerene ring, is designated as C Ａ２Ｆ When The fullerene ring is C Ａ１Ｆ and C Ａ２Ｆ A fullerene derivative having a ring containing

10. A fullerene derivative according to claim 7 or claim 8, A １ The carbon contained in Ｌ and having a bond that binds to R is designated as C Ａ１ and A ２ The carbon contained in, having a bond bonded to R Ｌ is defined as C Ａ２ when Carbon C Ａ１ and carbon C Ａ２ is a fullerene derivative in which they are bonded by a bond or separated by an element of 20 or less.

11. A fullerene derivative according to claim 7 or claim 8, A in formula (6) ３ is represented by formula (5-1), and R ３１１ , R ３１２ , R ３１３ , R ３１４ , R ３１５ is a fullerene derivative in which at least one of them contains an aryl group which may have one or more substituents.

12. The fullerene derivative according to claim 7 or claim 8, wherein the fullerene derivative is used as an electron transport layer material for a perovskite solar cell containing tin.

13. A composition comprising the fullerene derivative according to claim 7 or claim 8, A composition wherein when the fullerene derivative contained in the composition is 100% by mass, the content of the fullerene derivative represented by formula (6) is 0.1% by mass or more.

14. A composition according to claim 13, The composition contains two or more isomers of the fullerene derivative represented by formula (6), When the isomer having the highest content rate in the composition among the isomers of the fullerene derivative represented by formula (6) is defined as fullerene derivative FLN-D1, the content rate of fullerene derivative FLN-D1 with respect to 100% by mass of the fullerene derivative represented by formula (6) contained in the composition is 50% by mass or more.

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