JP6361009B2 - Dipyrine metal complex sheet having photoelectric conversion characteristics and method for producing the same - Google Patents

Description

  The present invention relates to a dipyrine metal complex sheet having photoelectric conversion characteristics. In more detail, this invention relates to the sheet | seat which has the photoelectric conversion characteristic formed from the metal complex polymer which made the dipyrine derivative the ligand.

  A new group of materials, “Nanosheet”, is attracting attention. A nanosheet is a two-dimensional crystal with a thickness of one to several atomic layers, and its use as a semiconductor active material layer leads to breakthroughs in electronic elements such as miniaturization, high density, high speed, and power saving. It is predicted. Research on nanosheets such as graphene and molybdenum disulfide concentrates on “top-down” nanosheets obtained by exfoliation of crystalline layered compounds (eg, graphite → graphene). On the other hand, chemists are also gaining a method of assembling nanosheets from the bottom up from constituent elements (organic molecules, metal atoms, ions). The advantages of this “bottom-up” nanosheet are: (1) Various variations with virtually unlimited combinations of components, (2) Free tuning of nanosheet structure and functionality (semiconductor properties, magnetism, etc.), (3 ) Concerted with the optical, magnetic, and electrical properties of the components and the physical properties of the nanosheets. At present, the report of “bottom-up type” nanosheets is limited to synthesis, and there is nothing that shows attractive physical properties.

  On the other hand, with the growing environmental protection, there is an increasing need for photovoltaic power generation that uses solar light, which is a renewable energy source. A solar cell is a power device that directly converts light energy into electric power by utilizing the photovoltaic effect. Conventionally, the semiconductor layers used in solar cells have been mainly silicon or compound semiconductors. However, since it has become obvious to improve the conversion efficiency, dye-sensitized solar cells that can greatly reduce manufacturing costs have been developed. It is getting in the spotlight.

The dye-sensitized solar cell mainly includes a photosensitive dye molecule that can absorb visible light and generate electron-hole pairs and a transition metal oxide that transmits the generated electrons. Dye-sensitized solar cells have attracted attention because their conversion efficiency has been greatly improved by the method of adsorbing ruthenium metal complex dyes on the surface of titanium dioxide fine particles proposed by Prof. Gretzel et al.
For this reason, the dye-sensitized solar cell currently under development is based on the structure proposed by Professor Gretzel, in which semiconductor fine particles such as titanium oxide adsorbed with a dye are deposited on the electrode as a light absorption layer. (Example: JP 2008-204956 A, JP 2009-132922 A).

JP 2008-204956 A JP 2009-132922 A

  However, from the viewpoint of expanding the technical potential of solar cells, it should be considered to construct a dye-sensitized solar cell using a material different from the conventional one. In view of the above circumstances, an object of the present invention is to provide a new sheet having photoelectric conversion characteristics that can be applied to a dye-sensitized solar cell by combining two technical fields of a bottom-up nanosheet and a solar cell. I will.

  The present inventors use a complex polymer by self-organization accompanied by complex formation by using a dipyrine derivative having a predetermined symmetrical structure and a metal salt or complex as raw materials and causing a complex formation reaction at the liquid-liquid interface or gas-liquid interface. It was found that the sheet can be easily produced. And it discovered that the said complex polymer sheet showed a photoelectric conversion characteristic. The present invention has been completed against the background of the above findings, and is specified by the following.

In one aspect, the present invention is a metal complex polymer sheet, wherein the metal complex polymer includes a dipyrine derivative represented by the formula (i) and a central metal, and the two dipyrine derivatives are included in one central metal. It is a sheet having a hexagonal network molecular structure that is constructed by repeating the connection, wherein the dipyrine derivatives are connected to each other by coordination.
Each Y is a monovalent group represented by formula (ii), each L independently represents a divalent linking group, each R ¹ independently represents a hydrogen atom or a substituent, and adjacent R ¹ may be bonded to each other to form a ring, and each X independently represents a carbon atom or a nitrogen atom, and R ¹ bonded to X does not exist when X represents a nitrogen atom.

In another aspect, the present invention provides a metal complex polymer sheet, wherein the metal complex polymer includes a dipyrine derivative represented by formula (iii) and a central metal, and two dipyrines per one central metal. It is a sheet having a hexagonal network molecular structure that is constructed by repeating the connection by connecting the dipyrine derivatives by coordination of the derivatives.
Each Y is a monovalent group represented by the formula (ii), each L independently represents a divalent linking group, A represents a nitrogen atom or a boron atom, and each R ¹ independently represents hydrogen. It represents an atom or a substituent, and adjacent R ^{1 's} may combine to form a ring.

In another aspect of the present invention, there is provided a metal complex polymer sheet, the metal complex polymer including a dipyrine derivative represented by the formula (iv) and a central metal, wherein The dipyrin derivative is linked to each other by coordination of the dipyrine derivative, and is a sheet having a triangular network molecular structure constructed by repeating the linkage.
Each Y is a monovalent group represented by formula (ii), each L independently represents a divalent linking group, each R ¹ independently represents a hydrogen atom or a substituent, and adjacent R ¹ may combine to form a ring.

In another aspect of the present invention, there is provided a metal complex polymer sheet, the metal complex polymer comprising a dipyrine derivative represented by formula (v) and a central metal, wherein The dipyrin derivative is linked to each other by the coordination of the dipyrine derivative, and the sheet has a rectangular network molecular structure constructed by repeating the linkage.

Each Y is a monovalent group represented by formula (ii), each L independently represents a divalent linking group, each R ¹ independently represents a hydrogen atom or a substituent, and adjacent R ¹ may be bonded to each other to form a ring, Q represents a hydrogen atom or a metal atom, Z represents a counter ion or an axial ligand, and n represents an integer of 0 or more.

  In one embodiment of the metal complex polymer sheet according to the present invention, each L is the same, and is substituted or unsubstituted p-phenylene group, substituted or unsubstituted 4,4′-biphenylylene group, substituted or unsubstituted. It is selected from the group consisting of alkenylene groups and substituted or unsubstituted alkynylene groups.

  In another embodiment of the metal complex polymer sheet according to the present invention, each L is a substituted or unsubstituted p-phenylene group.

In still another embodiment of the metal complex polymer sheet according to the present invention, each R ¹ is a hydrogen atom.

  In still another embodiment of the metal complex polymer sheet according to the present invention, the central metal is Zn, Ni, Pd, Pt, Cd, Hg, Co, Au, Ag, Sn, Pb or Cu.

  In still another embodiment of the metal complex polymer sheet according to the present invention, the average thickness is 0.5 nm to 100 μm.

  In yet another aspect of the present invention, an organic phase containing one or more dipyrrin derivatives represented by the above formula (i), formula (iii), formula (iv) or formula (v), and a central metal The metal complex polymer is formed at the interface between the organic phase and the aqueous phase by maintaining an aqueous phase containing at least one selected from a metal complex and a salt, while maintaining a phase-separated state. It is a manufacturing method of the metal complex polymer sheet | seat including the process of making a sheet grow.

  In another aspect of the present invention, an organic phase containing one or more dipyrrin derivatives represented by the above formula (i), formula (iii), formula (iv) or formula (v), a central metal, One of the aqueous phases containing at least one selected from the metal complex and the salt is coated with the other phase, and the two are kept in contact with each other while maintaining the phase-separated state. By this, it is a manufacturing method of the metal complex polymer sheet | seat including the process of growing a metal complex polymer in a sheet form in a gas-liquid interface.

  In one embodiment of the method for producing a metal complex polymer sheet according to the present invention, the growth time of the metal complex polymer is 1 second to 1 month.

  In another embodiment of the method for producing a metal complex polymer sheet according to the present invention, the metal complex polymer is grown only for a time necessary for the average thickness of the sheet to be 0.5 nm to 100 μm.

  In still another embodiment of the method for producing a metal complex polymer sheet according to the present invention, the method includes a step of flattening the sheet by heat treatment after collecting the grown metal complex polymer sheet.

  In still another aspect of the present invention, a solar cell using the metal complex polymer sheet according to the present invention for a light absorption layer.

  According to the present invention, a dipyrine metal complex sheet having photoelectric conversion characteristics is provided. There are several nanosheets synthesized bottom-up from organic compounds and metal ions, but this is the first to show photoelectric conversion characteristics. By using the sheet, there is a possibility that a dye-sensitized solar cell having an unprecedented structure and utilization method may be born.

It is a schematic diagram which shows an example of the molecular structure (part) of the metal complex polymer which concerns on this invention which contains a three-way dipyrine derivative as a ligand. It is a schematic diagram which shows an example of the molecular structure of the metal complex polymer based on this invention which contains a hexadirectional dipyrine derivative as a ligand. It is a schematic diagram which shows an example of the molecular structure of the metal complex polymer which concerns on this invention which contains a four-way dipyrine derivative as a ligand. The synthesis procedure of the nanosheet of Example 1 is shown. The AFM image of the nanosheet (single layer-several layers) of Example 1 is shown. The comparison of the absorption spectrum of the nanosheet (single layer-several layers) of Example 1 and a corresponding bis (dipyrinato) zinc mononuclear complex is shown. The change of the AFM image of the nanosheet (single layer) of Example 1 before and after scratching is shown. The change of the AFM image of the nanosheet (single layer-several layers) of Example 1 before and behind heat processing is shown. The synthesis procedure of the ligand L2 of Example 2 is shown. The synthesis procedure of the ligand L3 of Example 3 is shown. The synthesis procedure of the ligand L4 of Example 4 is shown. The synthesis procedure of the ligand L5 of Example 5 is shown. The synthetic | combination procedure of the porphyrin (compound 6) in Example 5 is shown. 7 is an XPS spectrum chart of a ligand L5 in Example 5. 7 is an XPS spectrum chart of the nanosheet synthesized in Example 5. FIG. 1 shows a reaction mechanism for synthesizing a dipyrine derivative according to formula (i). 2 shows a reaction mechanism for synthesizing a dipyrine derivative according to formula (iii). The reaction mechanism for synthesize | combining the dipyrine derivative which concerns on Formula (iv) is shown. 2 shows a reaction mechanism for synthesizing a dipyrine derivative according to formula (v). 2 shows another reaction mechanism for synthesizing a dipyrine derivative according to formula (i). 2 shows another reaction mechanism for synthesizing a dipyrine derivative according to formula (v). 2 is an XPS spectrum chart of the nanosheet synthesized in Example 1. FIG. It is a graph which shows the change of a photocurrent when changing the wavelength of the light to irradiate about the sample 1 of Example 6. FIG. It is a graph which shows the change of the photocurrent which flows according to on / off of the light of wavelength 500nm about the sample 1 of Example 6. FIG. It is a graph which shows the change of the photocurrent which flows according to on / off of the light of wavelength 500nm about the sample 2 of Example 6 (first 4 repetitions). It is a graph which shows the change of the photocurrent which flows according to on / off of the light of wavelength 500nm about the sample 2 of Example 6. (Whole). It is a graph which shows the change of the photocurrent which flows according to on / off of the light of wavelength 500nm about the sample 3 of Example 6. FIG. It is a graph which shows the change of the photocurrent which flows according to on / off of the light of wavelength 500nm about the sample 4 of Example 6 (first 4 repetitions). It is a graph which shows the change of the photocurrent which flows according to on / off of the light of wavelength 500nm about the sample 4 of Example 6 (whole). It is a graph which shows the change of the photocurrent which flows according to on / off of the light of wavelength 500nm about the sample 5 of Example 6. FIG. It is a graph which shows the change of the photocurrent which flows according to on / off of the light of wavelength 450nm about the sample 6 of Example 6. FIG.

<Ligand compound>
In one embodiment, the metal complex polymer sheet according to the present invention is formed from a metal complex polymer containing a dipyrine derivative represented by the formula (i) as a ligand.

Each Y is a monovalent group represented by formula (ii), each L independently represents a divalent linking group, each R ¹ independently represents a hydrogen atom or a substituent, and adjacent R ¹ may be bonded to each other to form a ring, and each X independently represents a carbon atom or a nitrogen atom, and R ¹ bonded to X does not exist when X represents a nitrogen atom.

The dipyrine derivative of formula (i) can be synthesized by the reaction mechanism shown in FIG. 16, for example. A 6-membered aromatic compound 1 substituted at the 1, 3 and 5 positions with a halogeno group or a pseudohalogeno group (bromine atom in FIG. 16), and a formyl group and a B (OR ² ) ₂ group at the end of the linking group L ( In the formula, when R ² is a hydrogen atom or an alkyl group (in FIG. 16, R ² = H), compound 2 is reacted in the presence of a catalyst such as Pd (PPh ₃ ) ₄ and a base such as sodium carbonate. Compound 3 is obtained (reaction 1). For reaction 1, in addition to the illustrated Suzuki coupling, various reactions such as Sonogashira coupling and Negishi coupling can be used.

Compound 3 is reacted with 5-membered aromatic compound 4 (pyrrole derivative) in the presence of an acid catalyst such as trifluoroacetic acid (TFA) or boron trifluoride diethyl ether complex (BF ₃ Et ₂ O) to formyl group and pyrrole derivative. The dipyrromethane of the formula (i) is obtained by producing dipyrromethane condensed with two and oxidizing the produced dipyrromethane (reaction 2). Although chloranil is suitable as the oxidizing agent for dipyrromethane, quinone-based oxidizing agents (eg, o-tetrachloroquinone, DDQ, etc.) and oxygen can also be used. Reaction 1 and reaction 2 are desirably performed in an inert atmosphere.

If the dipyrine derivative of the formula (i) cannot be successfully isolated from the reaction system after the reaction 2, it is possible to adopt a technique in which the dipyrine derivative is isolated after protection with BF ₂ and then deprotected. . Protection by BF ₂ is possible by reacting the dipyrine derivative of formula (i) with BF ₃ Et ₂ O in the presence of triethylamine (Et ₃ N), and deprotection by Chem. Asian J. 2012, 7, 907. The reaction described can be performed. The protection with BF ₂ may be carried out after reaction 2 or after simple purification and dissolution in a solvent such as dichloromethane. An example of a BF ₂ protected dipyrine derivative is shown in the following formula.

The dipyrrin derivative of the formula (i) is prepared by previously synthesizing a dipyrrin (E = H) or BODIPY (E = BF ₂ ) monomer, which is synthesized with a substrate having three reaction sites and Pd (PPh ₃ ) _4. It is also possible to synthesize by cross-coupling in the presence of a catalyst such as FIG. 20 shows an example of the reaction mechanism. In FIG. 20, Suzuki coupling is performed as the cross coupling. In FIG. 20, either route 1 or route 2 may be adopted. As R ² , a hydrogen atom or an alkyl group can be used, and as D 2, halogen and pseudohalogen (eg, trifluoromethylsulfonyl (OTf) group) can be used. Various reactions such as Sonogashira coupling and Negishi coupling can be used as the cross coupling. When E = BF ₂ , BF ₂ is deprotected as described above after cross coupling.

In another embodiment, the metal complex polymer sheet according to the present invention is formed from a metal complex polymer containing a dipyrine derivative represented by the formula (iii) as a ligand.
Each Y is a monovalent group represented by the formula (ii), each L independently represents a divalent linking group, A represents a nitrogen atom or a boron atom, and each R ¹ independently represents hydrogen. It represents an atom or a substituent, and adjacent R ^{1 's} may combine to form a ring.

The dipyrine derivative of formula (iii) can be synthesized, for example, by the reaction mechanism shown in FIG. A tertiary compound 5 in which three linking groups L each having a halogeno group or a pseudohalogeno group (in FIG. 17, a bromine atom) are bonded to a central nitrogen atom or boron atom is formylated with organolithium or the like to obtain a compound 6 (Reaction 3). Next, the compound 6 is reacted with a 5-membered aromatic compound 4 (pyrrole derivative) under an acid catalyst such as trifluoroacetic acid (TFA) or boron trifluoride diethyl ether complex (BF ₃ Et ₂ O) to form a formyl group. By producing dipyrromethane in which two pyrrole derivatives are condensed and oxidizing the produced dipyrromethane, a dipyrrin derivative of the formula (iii) is obtained (reaction 4). Although chloranil is suitable as the oxidizing agent for dipyrromethane, quinone-based oxidizing agents (eg, o-tetrachloroquinone, DDQ, etc.) and oxygen can also be used. Reaction 3 and reaction 4 are desirably performed in an inert atmosphere.

  The dipyrine derivative of formula (iii) is synthesized by the same procedure as in the synthesis method shown in FIG. 20 with respect to formula (i) except that the benzene ring at the center of the substrate having three reaction sites is replaced with a nitrogen atom or a boron atom. It is also possible.

In still another embodiment, the metal complex polymer sheet according to the present invention is formed from a metal complex polymer containing a dipyrine derivative represented by the formula (iv) as a ligand.
Each Y is a monovalent group represented by formula (ii), each L independently represents a divalent linking group, each R ¹ independently represents a hydrogen atom or a substituent, and adjacent R ¹ may combine to form a ring.

The dipyrine derivative of the formula (iv) can be synthesized, for example, by the reaction mechanism shown in FIG. Linking groups formyl and B at the end of L (OR ²⁾ ₂ group (wherein, R ² is a hydrogen atom or an alkyl group) (FIG. 18 in R ² = H) Compound 2 bound is B (OR ²⁾ ₂ After protecting the group with pinacol if necessary, acid catalyst such as 5-membered aromatic compound 4 (pyrrole derivative) and trifluoroacetic acid (TFA) or boron trifluoride diethyl ether complex (BF ₃ Et ₂ O) Reaction is carried out to produce dipyrromethane in which the formyl group and two pyrrole derivatives are condensed, and the resulting dipyrromethane is oxidized to obtain compound 7 (reaction 5). The B (OR ² ) ₂ group is preferably protected by pinacol or the like from the viewpoint of ease of handling, but it is not essential. Next, the dipyrine derivative of formula (iv) is obtained by reacting hexabromobenzene (compound 8) with compound 7 under a catalyst (reaction 6). Although chloranil is suitable as the oxidizing agent for dipyrromethane, quinone-based oxidizing agents (eg, o-tetrachloroquinone, DDQ, etc.) and oxygen can also be used. Reaction 5 and reaction 6 are desirably performed in an inert atmosphere.

  The dipyrine derivative of formula (iv) can also be synthesized by the same procedure with six reaction points of the substrate in the synthesis method shown in FIG. 20 for formula (i).

In yet another embodiment, the metal complex polymer sheet according to the present invention is formed from a metal complex polymer containing a dipyrine derivative represented by the formula (v) as a ligand.
Each Y is a monovalent group represented by formula (ii), each L independently represents a divalent linking group, each R ¹ independently represents a hydrogen atom or a substituent, and adjacent R ¹ may be bonded to each other to form a ring, each X independently represents a carbon atom or a nitrogen atom, Q represents a hydrogen atom or a metal atom, Z represents a counter ion or an axial ligand, n represents an integer of 0 or more.

  The dipyrine derivative of the formula (v) can be synthesized, for example, by the reaction mechanism shown in FIG. Compound 9 and pyrrole (compound 10) in which a formyl group and a halogeno group or pseudohalogeno group (bromine atom in FIG. 19) are bonded to the end of L ′ constituting a part of the linking group L are combined with trifluoroacetic acid (TFA) or the like. The reaction is carried out in the presence of an acid catalyst, followed by oxidation with an oxidant such as chloranil. When Q represents a metal atom, a complex formation reaction is further carried out in the presence of a metal salt to obtain a porphyrin compound 11 (Reaction 7). This is combined with the aforementioned compound 7 by Suzuki coupling to obtain the dipyrine derivative of the formula (v) (reaction 8). Reaction 7 and reaction 8 are desirably performed in an inert atmosphere. Regarding the reaction 8, in addition to the illustrated Suzuki coupling, various reactions such as Sonogashira coupling and Negishi coupling can be used.

According to another method, the dipyrine derivative of formula (v) can be synthesized by the reaction mechanism shown in FIG. Compound 12 having a formyl group and dipyrine (E = H) or BODIPY (E = BF ₂ ) moiety at the end of the linking group L and pyrrole (compound 10) are reacted under an acid catalyst such as trifluoroacetic acid (TFA), Subsequently, the porphyrin compound 13 is obtained by oxidizing with an oxidizing agent such as chloranil (reaction 9). In the formula (v), when Q represents a metal atom, a complex formation reaction is further performed in the presence of a metal salt. Further, after that, Z may be introduced to Q. When E = BF ₂ , BF ₂ is deprotected as described above.

  In the four-directional dipyrrin derivative represented by the formula (v), the metal atom Q in the porphyrin ring is not particularly limited and may be either a typical element or a metal atom of a transition element. A transition metal having a valence of is more preferable. Specific examples of the metal atom Q include Li, Be, Na, Mg, Al, K, Ca, Zn, Ga, Rb, Sr, Cd, In, Sn, Cs, Ba, Hg, and Tl as typical element metals. , Pb, Bi, Fr, Ra, and transition metals such as Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, So, Ir, Pt, Au, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg . One or more of these metal atoms Q can be arbitrarily selected. The metal atom Q is typically selected from the group consisting of Fe, Ni, Co, Cu, Zn, Sn, Ti, Mn, Mo, V, Zr, Cd, Ga, Sb, Cr, Nb, Al, and the like. One or more can be mentioned.

  The counter ion Z corresponds to various salts of the metal atom Q. The metal salt can be any of inorganic acids such as salts of hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, or organic acids. An axial ligand Z can be coordinated to the metal atom Q. The axial ligand Z is not particularly limited. For example, nitrogen-based axial ligands such as imidazole and its derivatives, pyridine and its derivatives, aniline and its derivatives, histidine and its derivatives, trimethylamine and its derivatives, thiophenol And its derivatives, sulfur axial ligands such as cysteine and its derivatives, methionine and its derivatives, benzoic acid and its derivatives, acetic acid and its derivatives, phenol and its derivatives, aliphatic alcohol and its derivatives, oxygen-based such as water An axial ligand is mentioned. n is a value of 0 or more according to the valence of the metal atom Q. When Q is a hydrogen atom, Q typically represents two hydrogen atoms. When Q is a hydrogen atom, Z does not exist.

In the formula (i), the formula (ii), the formula (iii), the formula (iv), and the formula (v), examples of the substituent represented by R ¹ include a halogen atom, a substituted or unsubstituted monovalent hydrocarbon group, Mercapto group, carbonyl mercapto group, thiocarbonyl mercapto group, substituted or unsubstituted hydrocarbon thio group, substituted or unsubstituted hydrocarbon thiocarbonyl group, substituted or unsubstituted hydrocarbon dithio group, hydroxyl group, substituted or unsubstituted Hydrocarbonoxy group, carboxyl group, aldehyde group, substituted or unsubstituted hydrocarbon carbonyl group, substituted or unsubstituted hydrocarbon oxycarbonyl group, substituted or unsubstituted hydrocarbon carbonyloxy group, cyano group, nitro group, amino Group, substituted or unsubstituted hydrocarbon monosubstituted amino group, substituted or unsubstituted hydrocarbon disubstituted amino group, phosphino group, substituted or unsubstituted hydrocarbon group Phosphino group, a substituted or unsubstituted hydrocarbon-disubstituted phosphino group, a group represented by the formula :-P (= O) (OH) 2, carbamoyl group, a substituted or unsubstituted hydrocarbon monosubstituted carbamoyl group, a substituted or Unsubstituted hydrocarbon disubstituted carbamoyl group, group represented by formula: —B (OH) ₂ , boric acid ester residue, sulfo group, substituted or unsubstituted hydrocarbon sulfo group, substituted or unsubstituted hydrocarbon A sulfonyl group, a substituted or unsubstituted monovalent heterocyclic group, a hydrocarbon group having two or more ether bonds, a hydrocarbon group having two or more ester bonds, a hydrocarbon group having two or more amide bonds A group represented by the formula: —CO ₂ M, a group represented by the formula: —PO ₃ M, a group represented by the formula: —PO ₂ M, a group represented by the formula: —PO ₃ M ₂ , formula: a group represented by -OM, wherein: a group represented by -SM, wherein: in -B (OM) ₂ Is a group of the formula: a group represented by -SO ₃ M, wherein: group (. Wherein, M is representative of the metal cation or a substituted or unsubstituted ammonium cations) represented by -SO ₂ M, wherein : 'group represented by the formula: -BR ₃ M' -NR ₃ M, a group represented by the formula: -PR ₃ 'group represented by the formula: -SR ₂ M' M group represented by (Wherein R represents a monovalent hydrocarbon group and M ′ represents an anion), and a substituted or unsubstituted monovalent monovalent quaternary nitrogen atom in the heterocyclic ring. Examples include heterocyclic groups.

R ¹ is a halogen atom, a substituted or unsubstituted hydrocarbon group, a hydroxyl group, a substituted or unsubstituted hydrocarbon oxy group, a carboxyl group, a substituted or unsubstituted hydrocarbon carbonyl group, a cyano group, an amino group, substituted or An unsubstituted hydrocarbon monosubstituted amino group, a substituted or unsubstituted hydrocarbon disubstituted amino group, a sulfo group, a substituted or unsubstituted monovalent heterocyclic group, and a hydrogen atom are preferred, and a halogen atom, substituted or unsubstituted A substituted hydrocarbon group, a hydroxyl group, a carboxyl group, a cyano group, an amino group, a substituted or unsubstituted monovalent heterocyclic group, and a hydrogen atom are more preferred, and a substituted or unsubstituted monovalent hydrocarbon group, substituted Or an unsubstituted monovalent heterocyclic group and a hydrogen atom are still more preferable, a monovalent hydrocarbon group and a hydrogen atom are still more preferable, and a hydrogen atom is especially preferable.

When R ¹ is a halogen atom, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom are preferred, a fluorine atom, a chlorine atom and a bromine atom are more preferred, and a chlorine atom and a bromine atom are still more preferred.

When R ¹ is a monovalent hydrocarbon group, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, nonyl group, dodecyl group, pentadecyl group C 1-20 alkyl group such as a group, octadecyl group, eicosyl group; 3 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group, cyclododecyl group, norbornyl group, adamantyl group A cycloalkyl group having 20 to 20 carbon atoms such as an ethenyl group, a propenyl group, a 3-butenyl group, a 2-butenyl group, a 2-pentenyl group, a 2-hexenyl group, a 2-nonenyl group, and a 2-dodecenyl group. Alkenyl group; phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4 Methylphenyl group, 4-ethylphenyl group, 4-propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, 4- Aryl groups having 6 to 20 carbon atoms such as adamantylphenyl group and 4-phenylphenyl group; phenylmethyl group, 1-phenyleneethyl group, 2-phenylethyl group, 1-phenyl-1-propyl group, 1-phenyl-2 -Propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, etc. An aralkyl group having 7 to 20 carbon atoms is exemplified, and an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 20 carbon atoms are preferable. A 12 alkyl group and an aryl group having 6 to 18 carbon atoms are more preferable, and an alkyl group having 1 to 6 carbon atoms and an aryl group having 6 to 12 carbon atoms are particularly preferable. In these monovalent hydrocarbon groups, at least a part (particularly 1 to 3, especially 1 or 2) of hydrogen atoms may be substituted, and examples of the substituent include halogens such as fluorine, chlorine and bromine. Atom: alkoxy group having 1 to 4 carbon atoms such as methoxy group, ethoxy group, propoxy group; methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, t- An alkoxycarbonyl group such as a butoxycarbonyl group; and a cyano group.

R ¹ is a hydrocarbon thio group, a hydrocarbon thiocarbonyl group, a hydrocarbon dithio group, a hydrocarbon oxy group, a hydrocarbon carbonyl group, a hydrocarbon oxycarbonyl group, a hydrocarbon carbonyloxy group, a hydrocarbon monosubstituted amino group, a hydrocarbon Disubstituted amino group, hydrocarbon monosubstituted phosphino group, hydrocarbon disubstituted phosphino group, hydrocarbon monosubstituted carbamoyl group, hydrocarbon disubstituted carbamoyl group, substituted or unsubstituted hydrocarbon sulfo group, substituted or unsubstituted hydrocarbon a sulfonyl group, the formula: 'group represented by the formula: -BR ₃ M' -NR ₃ M group represented by or the formula: -PR group represented by ₃ M ', the formula: -SR ₂ M In the case of a group represented by ', the hydrocarbon group moiety contained therein is as described above for the “monovalent hydrocarbon group”. At least a part of the hydrogen atoms in the hydrocarbon group part contained in these groups may be substituted in the same manner as in the case of the monovalent hydrocarbon group described above, and the same examples may be given as the substituents. it can.

Examples of the boric acid ester residue typically include groups represented by the following formulae.

  The monovalent heterocyclic group refers to the remaining atomic group obtained by removing one hydrogen atom from a heterocyclic compound. Heterocyclic compounds include pyridine, 1,2-diazine, 1,3-diazine, 1,4-diazine, 1,3,5-triazine, furan, pyrrole, thiophene, pyrazole, imidazole, oxazole, thiazole, oxa Monocyclic heterocyclic compounds such as diazole, thiadiazole, azadiazole, etc .; condensed polycyclic heterocyclic compounds in which two or more of the heterocyclic rings constituting the monocyclic heterocyclic compound are condensed; monocyclic heterocyclic Bridge two heterocyclic rings constituting a compound or one aromatic ring and one heterocyclic ring constituting a monocyclic heterocyclic compound with a divalent group such as a methylene group, an ethylene group or a carbonyl group. A bridged polycyclic heterocyclic compound having a crossed structure, and the like, and pyridine, 1,2-diazine, 1,3-diazine, 1,4-diazine, 1,3,5-triazine are preferable, Lysine, 1,3,5-triazine is preferred. The monovalent heterocyclic group may be substituted, and examples of the substituent include those mentioned for the monovalent hydrocarbon group described above.

Examples of the hydrocarbon group having two or more ether bonds include groups represented by the following formulas. In the formula, each R ′ independently represents a substituted or unsubstituted divalent hydrocarbon group. p is an integer of 2 or more.

  Examples of the divalent hydrocarbon group represented by R ′ include a methylene group, an ethylene group, a 1,2-propylene group, a 1,3-propylene group, a 1,2-butylene group, a 1,3-butylene group, 1 Divalent saturated hydrocarbon groups having 1 to 20 carbon atoms such as 1,4-butylene group, 1,5-pentylene group, 1,6-hexylene group, 1,9-nonylene group, 1,12-dodecylene group; 2 carbon atoms such as ethenylene group, propenylene group, 3-butenylene group, 2-butenylene group, 2-pentenylene group, 2-hexenylene group, 2-nonenylene group, 2-dodecenylene group, etc., and ethynylene group To 20 divalent unsaturated hydrocarbon groups; cyclopropylene group, cyclobutylene group, cyclopentylene group, cyclohexylene group, cyclononylene group, cyclododecylene group, norbornylene group, ada A divalent saturated hydrocarbon group having 3 to 20 carbon atoms such as an nylene group; a 1,3-phenylene group, a 1,4-phenylene group, a 1,4-naphthylene group, a 1,5-naphthylene group, 2, Examples include arylene groups having 6 to 20 carbon atoms such as 6-naphthylene group and biphenyl-4,4′-diyl group. At least a part of the hydrogen atoms of these divalent hydrocarbon groups may be substituted with a substituent. Examples of the substituent include those mentioned for the monovalent hydrocarbon group described above.

Examples of the hydrocarbon group having two or more ester bonds include groups represented by the following formulas. In the formula, R ′ and p are as described above.

Examples of the hydrocarbon group having two or more amide bonds include groups represented by the following formulae. In the formula, R ′ and p are as described above.

  The metal cation represented by M is preferably a 1 to 3 ion, and Li, Na, K, Cs, Be, Mg, Ca, Ba, Ag, Al, Bi, Cu, Fe, Ga, Mn, Examples include ions of metals such as Ni, Pb, Sn, Ti, V, W, Y, Yb, Zn, and Zr.

  The ammonium cation represented by M may be unsubstituted or substituted, and examples of the substituent include carbon such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, and t-butyl group. Examples thereof include an alkyl group having 1 to 10 atoms.

Examples of the anion represented by M ′ include F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , OH ⁻ , ClO ⁻ , ClO ₂ ⁻ , ClO ₃ ⁻ , ClO ₄ ⁻ , SCN ⁻ , CN ⁻ , NO ₃ ^−. , SO ₄ ²⁻ , HSO ⁴⁻ , PO ₄ ^3−, HPO ₄ ²⁻ , H ₂ PO ⁴⁻ , BF ⁴⁻ , PF ⁶⁻ , CH ₃ SO ³⁻ , CF ₃ SO ³⁻ , tetrakis (imidazolyl) Examples thereof include a borate anion, an 8-quinolinolato anion, a 2-methyl-8-quinolinolato anion, and a 2-phenyl-8-quinolinolato anion.

Examples of the monovalent heterocyclic group having a quaternized nitrogen atom in the heterocyclic ring include groups represented by the following formulae. In the formula, R and M ′ are as described above.

In Formula (i), Formula (ii), Formula (iii), Formula (iv), and Formula (v), adjacent R ^{1 's} may be bonded to form a ring. The number of constituent atoms of the formed ring is preferably 5 to 10, more preferably 5 to 7, and particularly preferably 6. In the formed ring, π electrons are preferably present so that conjugation spreads widely in the molecule from the viewpoint of photoelectric conversion characteristics, and it is more preferable that there are two or more π electrons to form an aromatic ring. Even more preferably.

In formula (i), formula (iii), formula (iv) and formula (v), the divalent linking group L is a substituted or unsubstituted divalent hydrocarbon group, and the following formula (A-1) To (A-7) are exemplified, and substituted or unsubstituted divalent hydrocarbon groups, (A-1) to (A-3), (A-6) and (A -7) is preferable, and the divalent group represented by (A-1), (A-2), and (A-3) is a substituted or unsubstituted divalent hydrocarbon group. And more preferably a substituted or unsubstituted divalent hydrocarbon group. In the formula, R ^d represents a hydrogen atom or a substituent. The substituent is as described for R ¹ , and the description of the examples is also the same, preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom or carbon number of 1 to 1. 10 alkyl groups, still more preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

  Examples of the substituted or unsubstituted divalent hydrocarbon group include a substituted or unsubstituted divalent saturated hydrocarbon group and a substituted or unsubstituted divalent unsaturated hydrocarbon group. It is preferably a valent unsaturated hydrocarbon group. Further, in these divalent hydrocarbon groups, the two regular binding sites are located in the opposite positions of the most distant positions (for example, in the para position in the case of an aromatic ring), the shape regularity and stability of the complex polymer. Desirable from a viewpoint.

  Examples of the substituted or unsubstituted divalent saturated hydrocarbon group include a substituted or unsubstituted alkylene group and a substituted or unsubstituted heteroalkylene group. The substituted or unsubstituted divalent unsaturated hydrocarbon group includes a substituted or unsubstituted alkenylene group, a substituted or unsubstituted heteroalkenylene group, a substituted or unsubstituted alkynylene group, a substituted or unsubstituted heteroalkynylene group. Is mentioned. 1-10 are preferable, as for carbon number in these saturated hydrocarbon groups and unsaturated hydrocarbon groups (when the hetero atom interposes), 1-5 are more preferable, and 1-3 are still more. preferable.

  Examples of the substituted or unsubstituted divalent unsaturated hydrocarbon group further include a substituted or unsubstituted arylene group and a substituted or unsubstituted heteroarylene group. 6-18 are preferable, as for carbon number in these unsaturated hydrocarbon groups (the number is also included when a hetero atom intervenes), 6-12 are more preferable, and 6-8 are still more preferable.

  Examples of the substituted or unsubstituted divalent unsaturated hydrocarbon group further include a substituted or unsubstituted aralkylene group and a substituted or unsubstituted heteroaralkylene group. 7-20 are preferable, as for the carbon number in these unsaturated hydrocarbon groups (the number is also included when a hetero atom intervenes), 7-12 are more preferable, and 7-9 are still more preferable.

  Among the substituted or unsubstituted divalent unsaturated hydrocarbon groups, a substituted or unsubstituted arylene group and a substituted or unsubstituted heteroarylene group are preferable from the viewpoint of structure and chemical stability.

  Examples of the hetero atom include an oxygen atom, a sulfur atom, and a nitrogen atom. When a plurality of heteroatoms are contained in the divalent hydrocarbon group, each heteroatom may be the same or different.

  When the divalent hydrocarbon group has a substituent, the substituent is a halogen atom such as fluorine, chlorine or bromine; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group or a propoxy group; a methoxycarbonyl group; Examples thereof include alkoxycarbonyl groups such as ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group and t-butoxycarbonyl group; cyano group and the like.

Specific examples of the alkylene group include an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, a 2-ethylhexamethylene group, an octamethylene group, and a decamethylene group. The alkylene group includes a cyclohexyl group. Also included are cyclic alkylene groups such as silene groups. Specific examples of the heteroalkylene group include a methyleneoxymethylene group, a methyleneoxyethylene group, an ethyleneoxyethylene group, an ethyleneoxymethyleneoxyethylene group, a methylenethiomethylene group, a methylenethioethylene group, and an ethylenethioethylene group. Specific examples of alkenylene group and alkynylene group include ethene-1,2-diyl group (—CH═CH— group), 2-butene-1,4-diyl group (—CH ₂ —CH═CH—CH). ₂ -group), and ethyne-1,2-diyl group (—C≡C— group). Specific examples of the arylene group include a phenylene group, a biphenylylene group, a naphthylene group, and an anthrylene group. Specific examples of the heteroarylene group include a pyridylene group, a pyrimidylene group, a dibenzofurylene group, and a dibenzothiophenylene group. And so on. Specific examples of the aralkylene group include a benzylidene group such as a styrylene group, a cinnamylidene group, a tolylene group, and a xylylene group.

<Center metal ion (Q ')>
In the metal complex polymer forming the metal complex polymer sheet according to the present invention, the central metal ion (Q ′) to which the above-mentioned ligand is coordinated is not particularly limited, and any of the typical element and transition element metal ions may be used. Good. Typical metal ions include Li, Be, Na, Mg, Al, K, Ca, Zn, Ga, Rb, Sr, Cd, In, Sn, Cs, Ba, Hg, Tl, Pb, Bi, Fr, Ra, and transition metal ions include Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd , La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, So, Ir, Pt, Au, Ac, Th , Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg. Q ′ can be arbitrarily selected from one or more of these. Q ′ is typically selected from the group consisting of ions of Fe, Ni, Co, Cu, Zn, Sn, Ti, Mn, Mo, V, Zr, Cd, Ga, Sb, Cr, Nb, and Al. It can be one or more.

<Metal complex polymer sheet>
The metal complex polymer sheet according to the present invention utilizes the self-organization phenomenon at the liquid-liquid interface or gas-liquid interface using the above-described ligand compound and the above-described complex or salt of the central metal ion as raw materials. It can be produced by forming a complex polymer spread in two dimensions. The obtained sheet can exhibit photoelectric conversion characteristics and is useful, for example, as a light absorption layer of a dye-sensitized solar cell.

  Specifically, in one embodiment of the method for producing a metal complex polymer sheet according to the present invention, a dipyrine derivative represented by formula (i), formula (iii), formula (iv) or formula (v) is contained. The organic phase and the aqueous phase containing one or more selected from the complex and salt of the metal that is the central metal, while maintaining the phase-separated state, And growing a metal complex polymer in the form of a sheet at the interface of the phases.

  In another embodiment of the method for producing a metal complex polymer sheet according to the present invention, an organic phase containing a dipyrine derivative represented by formula (i), formula (iii), formula (iv) or formula (v) And one of the aqueous phases containing one or more selected from the metal complex and salt as the central metal is coated with the other phase, while maintaining the state in which both phases are separated. And the step of growing the metal complex polymer in a sheet form at the gas-liquid interface by continuing the contact.

  In a typical embodiment of the method for producing a metal complex polymer sheet according to the present invention, an organic phase containing a dipyrine derivative represented by formula (i), formula (iii), formula (iv) or formula (v) A step of supplying an aqueous phase containing at least one selected from a complex of a metal and a salt as a central metal, and then maintaining a state in which both are phase-separated, whereby an organic phase and an aqueous phase And a step of growing a metal complex polymer in the form of a sheet at the interface. The water phase supplied from above disturbs the interface between the water phase and the organic phase, and as a result, to prevent the structural disorder of the nanosheet, before the water phase is supplied, the organic phase is A buffer layer may be formed thereon. By providing the buffer layer, the contact between the organic phase and the aqueous phase proceeds gently.

  By reducing the amount of the aqueous phase supplied from above and forming the thin aqueous phase, the thickness of the formed polymer sheet can also be reduced. When the aqueous phase is formed extremely thin by this method, substantially all of the metal complexes and salts contained in the supplied aqueous phase are used and consumed in the complexing reaction, and the metal complex polymer sheet is not at the liquid-liquid interface, It is formed at the gas-liquid interface. It is also possible to form a single layer polymer sheet by this method. Therefore, in one embodiment of the method for producing a metal complex polymer sheet according to the present invention, an organic phase containing a dipyrine derivative represented by formula (i), formula (iii), formula (iv) or formula (v) Is coated with an aqueous phase containing at least one selected from a complex of metal and a salt as a central metal, and the contact between the two is continued while maintaining a phase-separated state. And growing the metal complex polymer in a sheet form.

  In another exemplary embodiment of the method for producing a metal complex polymer sheet according to the present invention, a formula (i) is formed on an aqueous phase containing at least one selected from a metal complex and a salt as a central metal. ), Supplying the organic phase containing the dipyrine derivative represented by formula (iii), formula (iv) or formula (v), and then maintaining the state in which the two are phase-separated, And a step of growing the metal complex polymer in a sheet form at the interface of the aqueous phase. In order to prevent the interface between the aqueous phase and the organic phase from being disturbed by the organic phase supplied from above, resulting in structural disorder in the nanosheet, water is supplied with a pure organic solvent before supplying the organic phase. A buffer layer may be formed on the phase. By providing the buffer layer, the contact between the organic phase and the aqueous phase proceeds gently.

  By reducing the amount of the organic phase supplied from above and forming the organic phase thin, the thickness of the formed polymer sheet can also be reduced. When the organic phase is formed very thin by this method, substantially all dipyrine derivatives represented by formula (i), formula (iii), formula (iv) or formula (v) contained in the supplied organic phase are complexed. Used in the reaction and consumed, the metal complex polymer sheet is formed at the gas-liquid interface instead of the liquid-liquid interface. It is also possible to form a single layer polymer sheet by this method. Therefore, in still another embodiment of the method for producing a metal complex polymer sheet according to the present invention, an aqueous phase containing one or more selected from a metal complex and a salt as a central metal is represented by the formula (i). By coating with an organic phase containing the dipyrine derivative represented by formula (iii), formula (iv) or formula (v) and maintaining the phase-separated state, And growing a metal complex polymer in a sheet form at the liquid interface.

  Although it is not intended that the present invention be limited by theory, the organic phase containing the dipyrine derivative represented by formula (i), formula (iii), formula (iv) or formula (v) and the central metal An aqueous phase containing a metal salt or complex is maintained in a phase-separated state while maintaining contact with each other, whereby the two dipyrine derivatives are coordinated to one central metal, whereby the dipyrine Derivatives are linked to each other, and it is considered that the network molecular structure grows by repeating the linkage in three directions, four directions, or six directions depending on the type of dipyrine derivative.

  Further, the sheet can be grown thick by increasing the contact time at the interface. Although it is not intended that the present invention be limited by theory, it is considered that a single layer sheet grown in a two-dimensional direction becomes thicker by being laminated.

  When the dipyrine derivative represented by formula (i), formula (iii), formula (iv) or formula (v) is used as the ligand, a single type of ligand may be used, Combinations of different types of ligands may be used. However, from the viewpoint of uniformity, quality stability and shape stability of the sheet to be produced, it is preferable to combine the ligands used with dipyrine derivatives included in the same general formula, More preferably.

  In carrying out the manufacturing method, a complicated operation is unnecessary, and an expensive manufacturing apparatus is also unnecessary. Therefore, the metal complex polymer sheet according to the present invention can be produced at low cost. Further, since the area of the sheet depends on the area of the liquid-liquid interface, the area of the obtained sheet can be easily increased by increasing the reaction container. That is, the production method according to the present invention is advantageous for industrial production.

  The solvent for the dipyrine derivative is not particularly limited as long as it dissolves the dipyrine derivative, but a low-polar solvent can be preferably used in order to maintain the phase separation state of the organic phase and the aqueous phase, for example, petroleum ether. A solvent containing at least one selected from dichloromethane, benzene, toluene, dichloroethane, tetrachloromethane, cyclohexane, chloroform, carbon tetrachloride, and hexane can be mentioned as a preferable example. As the solvent, other solvents can also be mixed and used, but the ratio of the low polarity solvent to the whole solvent is preferably 50% or more by volume, more preferably 70% or more, still more preferably 90% or more, 95% or more is particularly preferable.

  Examples of the metal salt or complex used as the central metal include salts of inorganic acids (eg, hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, etc.), salts of organic acids (eg, carboxylic acid, sulfonic acid), ammine complexes, cyano. Complexes, halogeno complexes, and hydroxy complexes are exemplified.

  The reaction temperature may be appropriately set in consideration of the reaction rate, but can be performed at a temperature not lower than the freezing point and not higher than the boiling point of the solvent used. Moreover, although reaction time is not specifically limited, It can be set as 1 second-about 1 month, and a film thickness can be adjusted according to reaction time. Typically, it can grow to a thickness of several hundred nm with a reaction time of about one day. The obtained sheet | seat can be isolate | separated by a general method, for example, filtration, solvent removal, etc. However, the prepared sheet is very thin, so that it does not break during removal from the liquid, so that it can be prepared in a large container and easily removed, the Langmuir-Schaefer method (the liquid in which the sheet is formed) It is also possible to use a method in which the substrate is moved parallel to the liquid interface or the gas-liquid interface and transferred to the substrate), or a method of scooping up with a hard substrate. By repeatedly applying the Langmuir-Schaefer method to the same substrate, it is also possible to create a multi-layered film of sheets.

  The thickness of the metal complex polymer sheet according to the present invention is preferably 0.5 nm or more on average from the viewpoint of enhancing light absorption ability and photoelectric conversion characteristics and improving strength, and is preferably 50 nm or more on average. More preferably, it is more preferably 100 nm or more on average. In addition, the thickness of the polymer sheet according to the present invention is preferably 100 μm or less on average for reasons of inhibition of the carrier transfer process of the polymer sheet or the transfer process of the redox mediator / electrolyte, and is preferably 10 μm or less on average. More preferably, the average value is even more preferably 1 μm or less. In this invention, the average value of the thickness of a polymer sheet points out the value measured with the atomic force microscope.

  After recovering the metal complex polymer sheet after growth, the sheet can be flattened by heat treatment. When the metal complex polymer is placed on the substrate from the reaction solution, wrinkles are often formed because the sheet is flexible. Although the effect of the wrinkles on the photoelectric conversion characteristics has not been clarified, it can be a factor that at least hinders adhesion to the substrate or damages the sheet, so it is placed on the substrate in a flat state without wrinkles. It is desirable that In this regard, when the metal complex polymer according to the present invention placed on the substrate is heat-treated, the wrinkles are extended and the sheet can be flattened. The heat treatment may be performed under conditions that do not adversely affect the physicochemical properties of the sheet at a temperature effective for removing wrinkles, and examples of such conditions include, for example, 30 to 500 ° C. for 10 seconds to 1 week. Typically, a heat treatment is performed at 80 to 150 ° C. for 1 to 5 days, and more typically a heat treatment at 120 ° C. for 3 days.

  Although it is not intended that the present invention be limited by theory, in the present invention, since the growth region of the complex formation reaction is limited to a two-dimensional plane that is the interface between the organic phase and the aqueous phase liquid, It is thought that the complexing reaction between the dipyrine derivative and metal ions spreads in a planar manner in a chain due to the self-organization phenomenon. In particular, since the dipyrine portion of the dipyrine derivative used as a ligand in the present invention is located on the same plane and in point symmetry, it is considered that a planar sheet can grow regularly. Thereby, in the case of the three-directional dipyrrin derivative represented by the formula (i) or the formula (iii), a complex polymer having a hexagonal network structure as illustrated in FIG. 1 grows, and is represented by the formula (iv). If a hexagonal dipyrrin derivative represented by the formula (v) is grown, a complex polymer having a triangular network structure as illustrated in FIG. 2 grows. It is assumed that a complex polymer having a square network structure grows.

  The metal complex polymer sheet according to the present invention can exhibit insoluble properties with respect to water and organic solvents, in addition to the feature of having photoelectric conversion characteristics. In addition, the metal complex polymer sheet according to the present invention can be characterized by excellent durability (cycle characteristics). This is considered to be caused by the fact that the polymer sheet according to the present invention is formed of a complex polymer having a very high degree of polymerization and regularly arranged in a planar shape, and also has a large spread of conjugated π-electron system.

<Solar cell>
A solar cell can be produced by using the metal complex polymer sheet according to the present invention as a material of a light absorption layer in which photoelectric conversion is performed. Typically, dye-sensitized solar cells can be made. In one embodiment, a solar cell according to the present invention includes a pair of electrodes, a light absorption layer including the metal complex polymer sheet according to the present invention between the electrodes, and an optional electrolyte layer. When light such as sunlight is incident on the solar cell according to the present invention, the light is absorbed by the light absorption layer having photoelectric conversion characteristics, and an electromotive force is generated between the electrodes. The generated electromotive force allows a current to flow from one electrode to the other through an external circuit. The laminated structure of the solar cell using the metal complex polymer sheet which concerns on this invention is shown illustratively.
(1) Substrate / electrode / light absorption layer / counter electrode (2) substrate / light absorption layer / electrolyte / counter electrode (3) substrate / electrode / electrolyte / light absorption layer / counter electrode (4) substrate / electrode / electrolyte / Light absorption layer / electrolyte / counter electrode

  Examples of the substrate include glass, plastic, ceramic, resin film, silicon, metal, mirror and the like. In the case of an opaque substrate, the opposite electrode is preferably transparent or translucent.

The electrode is not limited, but a conductive metal oxide film, a translucent metal thin film, or the like can be used. From the viewpoint of improving conversion efficiency, it is preferable to use a porous electrode made of semiconductor particles. . Specific examples include indium oxide, zinc oxide, tin oxide, and indium tin oxide alloys (ITO), indium zinc oxide (IZO), gold, platinum, silver, copper, and the like, which are composites thereof. Examples include oxide semiconductors such as TiO ₂ , SnO ₂ , ZrO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , SrTiO ₃ , BaTiO ₃ , CaTiO ₃ , KTaO ₃ , WO ₃ and a composite system between these oxides. TiO ₂ is preferred. Moreover, you may use organic transparent conductive films, such as polyaniline and its derivative (s), polythiophene, and its derivative (s) as an electrode material. The film thickness of the electrode can be set to, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, more preferably 50 nm to 500 nm in consideration of light transmittance and electric conductivity. be able to.

  The electrolyte is not limited, but is preferably a compound such as lithium salt, sodium salt, potassium salt, ammonium salt, such as lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate, trifluoro Ammonium perchlorates such as lithium sulfate, lithium hexafluoroarsenate, tetrabutylammonium perchlorate, tetraethylammonium perchlorate, tetrapropylammonium perchlorate, tetrabutylammonium hexafluorophosphate, hexafluorophosphoric acid Examples thereof include ammonium hexafluorophosphates such as tetraethylammonium and tetrapropylammonium hexafluorophosphate.

An appropriate amount of various redox mediators can be added to the electrolyte from the viewpoint of increasing the photoelectric conversion efficiency. Examples of redox mediators include transition metal redox mediators, organic redox mediators, and inorganic redox mediators. Examples of transition metal redox mediators include Cu ²⁺ / Cu redox mediator, Fe ³⁺ / Fe ²⁺ redox mediator, [Fe (CN) ₆ ] ⁴⁺ / [Fe (CN) ₆ ] ³⁺ redox mediator, cobalt Polypyridine redox mediators (eg, tris (2,2′-bipyridine) cobalt (III / II) ([Co (bpy) ₃ ] ^{3 + / 2 +} ), tris (4,4′-dimethyl-2,2 ′) -Bipyridine) cobalt (III / II) ([Co (dmb) ₃ ] ^{3 + / 2 +} ), tris (4,4'-di-tert-butyl-2,2'-bipyridine) cobalt (III / II) ([Co (dtb) ₃ ] ^{3 + / 2 +} ), tris (1,10-phenanthroline) cobalt (III / II) ([Co (phen) ₃ ] ^{3 + / 2 +} )) and the like. Examples of the organic redox mediator include quinone / hydroquinone redox mediator, polyaniline, and nitroxy radical compound. The inorganic redox mediator, for example, I ^3- / I ^- redox mediator, Br ^3- / Br ^- redox mediator, NO ₂ / NO redox mediator, and the like.

  In the solar cell according to the present invention, any of a liquid electrolyte, a gel electrolyte, and a solid electrolyte can be used. That is, according to the present invention, for example, an all-solid-state dye-sensitized solar cell can be manufactured.

  There is no restriction | limiting in the use of the solar cell which concerns on this invention, It can use for arbitrary uses. For example, for building materials, automobiles, interiors, railways, ships, airplanes, spacecrafts, home appliances, stationery, mobile phones, watches, mobile terminals, wearable terminals, toys, and glasses And other uses. In addition, a storage battery can be provided to enable use at night.

EXAMPLES Examples (invention examples) of the present invention are shown below together with comparative examples, which are provided for better understanding of the present invention and its advantages, and are not intended to limit the invention. . ^{For 1} H NMR measurement, a JEOL AL 400 type nuclear magnetic resonance spectrometer (400 MHz) was used. The spectrum was calibrated with the tetramethylsilane peak at 0.00 ppm and the chloroform peak at 7.26 ppm.

Example 1
A metal complex nanosheet was prepared by the synthesis procedure shown in FIG.

<Synthesis of Compound 1>

To a solution of 1,3,5-tribromobenzene (1.26 g, 4.0 mmol) in a 15/15 mL mixed solvent of tetrahydrofuran / toluene, 4-formylphenylboronic acid (3.51 g, 23.4 mmol), Pd (PPh ₃ ) ₄ (693 mg, 0.6 mmol, 15 mmol%) and Na ₂ CO ₃ (2.48 g, 23.4 mmol in 5 mL water) were added. The resulting mixture was heated at reflux temperature for 16 hours, and the progress of the reaction was confirmed by thin layer chromatography (TLC) using a mixture of n-hexane: ethyl acetate = 5: 1 (volume ratio) as an eluent. After cooling to room temperature, water was added and the mixed solution was extracted with ethyl acetate. The organic phase was dried over anhydrous Na ₂ SO ₄ and filtered. Thereafter, the mixture was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography using a mixed solution (volume ratio) of n-hexane: ethyl acetate = 5: 1 as an eluent to obtain Compound 1 as a white solid.
¹ H NMR (400 MHz, CDCl ₃ , δ / ppm): 10.09 (s, 3H, O = CH), 8.03-8.01 (d, J = 8.0, 6H), 7.88-7.86 (d, J = 8.0, 6H ), 7.91 (s, 3H); FAB-MS (m / z): 390 [M] ⁺ .

<Synthesis of Compound 2>

A mixture of 2.0 g pyrrole-2-carboxaldehyde, 6.0 g potassium hydroxide, and 5 mL hydrazine monohydrate was placed in a 100 mL container. Then 1.7 g of ethylene glycol was added and the mixture was refluxed at 150 ° C. for about 1.5 hours. After cooling to room temperature, extraction with diethyl ether, washing with deionized water and brine, drying with anhydrous MgSO ₄ , and solvent removal by distillation under reduced pressure were performed to obtain a pale yellow product (compound 2) (4.20 g). Yield: 82.5%).
¹ H NMR (400 MHz, CDCl ₃ , δ / ppm): 7.69 (s, 1H, NH), 6.50-6.49 (d, 1H, J = 4.0), 6.03-6.01 (t, 1H, J = 4.0), 5.8 (s, 1H), 2.14 (s, 3H, CH ₃ ); FAB-MS (m / z): 81 [M] ⁺ .

<Synthesis of Ligand L1>

Compound 1 (450 mg, 1.15 mmol) and compound 2 (2-methylpyrrole) (0.63 mL, 7.49 mmol) were dissolved in 100 mL of CH ₂ Cl ₂ under Ar atmosphere. When a drop of trifluoroacetic acid (TFA) was added, the solution turned from pale yellow to bright red. Stirring was performed at room temperature for 3 hours. After confirming that the aldehyde was completely consumed by TLC (silica, CH ₂ Cl ₂ ), a solution of chloranil (848.2 mg, 3.45 mmol) in CH ₂ Cl ₂ was added and stirring was continued for 15 minutes. . The reaction mixture was washed with water, dried over anhydrous MgSO ₄ , filtered, and evaporated to dryness using an evaporator. The obtained crude compound was purified by alumina column chromatography (eluent: CH ₂ Cl ₂ ) to obtain the ligand L1 as a deep yellow powder (230.7 mg, yield: 24.5%).
¹ H NMR (400 MHz, CDCl ₃ , δ / ppm): 7.95 (s, 3H, Ar), 7.81-7.79 (d, J = 8.0 Hz, 6H, Ar), 7.62-7.60 (d, J = 8.0 Hz , 6H, Ar), 6.57-6.56 (d, J = 4.0 Hz, 6H, Ar), 6.20-6.19 (d, J = 4.0 Hz, 6H, Ar), 2.47 (s, 18H, -CH ₃ ); ¹³ C NMR (100 MHz, CDCl ₃ , δ / ppm): 165.18, 146.78, 141.99, 137.88, 135.32, 132.12, 130.51, 128.89, 127.12, 116.54, 112.11, 105.97 (Ar), 18.21 (CH ₃ ); FAB-MS (m / z): 817 [M] ⁺ .

<Nanosheet Synthesis (1): Single Layer Sheet>
30 mL of a 50 mM zinc acetate (II) aqueous solution was put in a vial, and a very small amount (14 μL) of a 1 mM ligand L1 dichloromethane solution was sprayed onto the zinc acetate (II) aqueous solution with a microsyringe. After leaving still for 20 minutes, the nanosheet generated at the gas-liquid interface was transferred to various substrates using the Langmuir-Schaefar method. The nanosheet was synthesized a plurality of times by the same procedure to obtain a plurality of sheets. An AFM image of one of the obtained sheets is shown in FIG. It can be seen that nanosheets having a size exceeding 100 μm ² are formed.

(Chemical structure)
A visible light absorption spectrum of one of the obtained nanosheets was measured and compared with a dinuclear ligand-containing mononuclear complex represented by the following formula (FIG. 6).
As a result, the peak around the wavelength of 495 nm seen in the mononuclear complex was shifted to the wavelength of 500 nm on the long wavelength side, suggesting the formation of the complex.
Moreover, the said nanosheet was affixed on the conductive carbon double-sided tape, it was set as the sample, and the X-ray photoelectron spectrum was measured using PHI 500 Versa Probe of ULVAC-PHI. Measurement was performed using AlKα rays (15 kV, 25 W or 20 kV, 100 W) as an X-ray light source. The spectrum obtained was corrected for charge-up so that the C1s peak was 284.6 eV. The obtained spectrum was compared with that of the dipyrine ligand (a) represented by the following formula and the monomer complex (b) of the ligand. The results are shown in FIG. It can be seen that N, which was not equivalent in the ligand state, became equivalent in the monomer complex and nanosheet. Moreover, Zn which was not seen in the state of a ligand was confirmed in the monomer complex and the nanosheet.
From these results, it can be determined that the nanosheet is a complex polymer having the ligand L1 and has a hexagonal network molecular structure.

(Film thickness)
One of the obtained nanosheets was placed on a Si-TMS substrate, a part of the nanosheet was scratched and cut out with an AFM probe, and the thickness was scanned in the direction of the arrow in the right diagram of FIG. . As a result, it was confirmed that the sheet had an average thickness of about 1.2 nm. The film thickness was measured on a flat portion avoiding the edge and wrinkle portion of the film. This thickness value indicates that the obtained nanosheet is a single layer.

(Effect of heat treatment)
FIG. 8 shows changes in the AFM image when one of the obtained nanosheets was placed on a Si-TMS substrate and heated in a dryer at 120 ° C. for 3 days. The wrinkles (typically the discoloration on the straight line existing in the circled area in FIG. 8A) that had been seen before the heat treatment almost disappeared after the heat treatment and changed to a flat sheet. I understand that.

<Nanosheet Synthesis (2): Multilayer Sheet>
10 mL of a 1 mM ligand L1 dichloromethane solution is placed in a vial, and 10 mL of pure water is gently overlaid on the dichloromethane solution so that the separated state of the aqueous phase and the organic phase is maintained. 20 mL of aqueous zinc (II) solution was gently piled up. When allowed to stand for 1 day, it was confirmed that a thin orange insoluble sheet was formed at the interface between the aqueous phase and the organic phase.

  When the film thickness of the sheet was measured by AFM, it was confirmed that the thickness was about 1000 nm on average. The film thickness was measured on a flat portion avoiding the edge and wrinkle portion of the film. This thickness value indicates that the obtained nanosheet is multilayer.

(Example 2)
Ligand L2 was synthesized by the synthesis procedure shown in FIG.

<Compound 2 '>
A pyrrole compound represented by the following formula was obtained from Wako Pure Chemical Industries.

A mixture of 2.0 g pyrrole-2-carboxaldehyde, 6.0 g potassium hydroxide, and 5 mL hydrazine monohydrate was placed in a 100 mL container. After adding 1.7 g of ethylene glycol, the mixture was refluxed at 150 ° C. for about 1.5 hours. After cooling to room temperature, extraction with diethyl ether, washing with deionized water and brine, drying with MgSO ₄ , and removal of the solvent by distillation under reduced pressure yielded a pale yellow product (compound 2 ′) (4.20 g). Yield: 82.5%).

<Synthesis of Ligand L2>

Ligand L2 was synthesized from compound 1 and compound 2 ′ according to the same synthesis procedure as ligand L1 (FIG. 9). Ligand L2 was obtained as an orange powder (yield: 24.2%).
¹ H NMR (400 MHz, CDCl ₃ , δ / ppm): 7.99 (s, 3H, Ar), 7.87-7.85 (d, J = 8.0 Hz, 6H, Ar), 7.46-7.45 7.81-7.79 (d, J = 8.0 Hz, 6H, Ar), 2.33 (s, 18H, -CH ₃ ), 2.31-2.27 (q, 12H, -CH _2- ), 1.31 (s, 18H, -CH ₃ ), 1.01-1.96 (t , J = 8.0 Hz, 18H, -CH ₃ ); ¹³ C NMR (100 MHz, CDCl ₃ , δ / ppm): 150.29, 141.89, 140.51, 138.32, 137.01, 136.04, 134.59, 131.33, 130.22, 127.23, 125.05 ( Ar), 17.58, 14.88, 14.41, 12.11 (alkyl); FAB-MS (m / z): 1070 [M] ⁺ .

(Example 3)
Ligand L3 was synthesized by the synthesis procedure shown in FIG.

<Synthesis of Compound 3>

A pentane solution (15.9 mL) of 1.57 M t-BuLi was added dropwise to 30 mL of an anhydrous diethyl ether solution of tris (4-bromophenylamine) (2 g, 24.9 mmol) at −78 ° C. under a nitrogen atmosphere. The reaction mixture was stirred for 1 hour while maintaining the temperature, then anhydrous DMF (1.92 mL, 24.9 mmol, 6 eq) was added dropwise. The resulting reaction suspension was returned to room temperature and stirred for 2 hours. The reaction was controlled by slowly adding saturated NH ₄ Cl. After distilling off the organic solvent, the aqueous phase was extracted with dichloromethane. The organic phase was dried with anhydrous MgSO ₄ and evaporated to dryness with an evaporator, and then purified by silica gel column chromatography using a mixed solution of n-hexane: ethyl acetate = 1: 1 (volume ratio) as an eluent to give compound 3 as a light Obtained as a yellow solid (852 mg, yield: 46%).
¹ H NMR (400 MHz, CDCl ₃ , δ / ppm): 9.95 (s, 3H, O = CH), 7.86-7.84 (d, 6H, J = 8.0), 7.26-7.24 (d, 6H, J = 8.0 ); FAB-MS (m / z): 330 [M] ⁺ .

<Synthesis of Ligand L3>
Ligand L3 was synthesized from compound 3 and compound 2 synthesized in Example 1 according to the same synthesis procedure as ligand L1 (FIG. 10). Ligand L3 was obtained as a brown solid (yield: 18.7%).
¹ H NMR (400 MHz, CDCl ₃ , δ / ppm): 7.45-7.43 (d, 6H, J = 8.0), 7.24-7.22 (d, 6H, J = 8.0), 6.62-6.61 (d, 6H, J = 4.0), 6.20-6.19 (d, 6H, J = 4.0), 2.46 (s, 18H, CH ₃ ); FAB-MS: 756.

Example 4
Ligand L4 was synthesized by the synthesis procedure shown in FIG.

<Synthesis of Compound 4>
4-Formylphenylboronic acid (2.002 g, 13.35 mmol) plus 1.1 equivalents of pinacol (1.806 g, 15.28 mmol) was dissolved in THF (30 mL) and toluene (30 mL). Immediately after that, the solvent was distilled off using a rotary evaporator and dried under vacuum to quantitatively obtain 4-formylphenylboronic acid protected with pinacol. After adding anhydrous sodium sulfate to the protected one, nitrogen substitution was performed. Dissolve in dichloromethane and add 2.1 equivalents of 2-methylpyrrole (2.55 mL, 29.5 mmol) and a catalytic amount (50 μL) of trifluoroacetic acid (TFA) to the protected one at room temperature under light-shielding conditions. Stirring was performed for 3 hours. After releasing to the atmosphere, 1.1 equivalent of chloranil (3.61 g, 14.7 mmol) was added and stirred at room temperature for 5 minutes. After 5 minutes, the solvent of the reaction mixture was distilled off, and separation was performed by alumina column chromatography (eluent: dichloromethane) to obtain Compound 4 (2.677 g, yield: 54%).
¹ H NMR (CDCl ₃ , 25 ° C) δ = 7.84 (d, J = 8.05, 2H), 7.46 (d, J = 8.05, 2H), 6.42 (d, J = 4.03, 2H), 6.14 (d, J = 4.03, 2H), 2.44 (s, 3H) 1.38 (s, 6H)

<Synthesis of Ligand L4>

Hexabromobenzene (60.2 mg, 0.109 mmol) in 15 equivalents of compound 4 (819 mg, 2.19 mmol) and a catalytic amount of bis (triphenylphosphine) palladium (II) dichloride (Pd (PPh ₃ ) ₂ Cl ₂ , 52.0 mg, 74 mmol), triphenylphosphine (PPh ₃ , 113 mg, 431 mmol), and 6 equivalents of potassium carbonate (94.1 mg, 0.68 mmol) were added to DMSO (30 mL), tert-butanol under nitrogen. (5 mL) and water (1.5 mL) were dissolved in a mixed solvent. The reaction solution was freeze-degassed and then stirred for 1 week at 90 ° C. under light-shielding conditions. After 1 week, brine and dichloromethane were added to the reaction solution released into the atmosphere, and the mixture was stirred for several minutes. This was washed with water and then dried over anhydrous sodium sulfate, and then the solvent was distilled off with a rotary evaporator. The reaction product was roughly purified by alumina column chromatography (eluent: dichloromethane), and then the ligand L4 was separated using GPC (1.1 mg, yield: 1%).

(Example 5)
Ligand L5 was synthesized from the dipyrine synthesized in Example 4 (compound 4) and porphyrin (compound 6) by Suzuki coupling (FIG. 12).

<Synthesis of Compound 6>
Compound 6 was synthesized according to the procedure shown in FIG. Pyrrole (370 μL, 5.4 mmol) and p-bromobenzaldehyde (1.0 g, 5.4 mmol) were dissolved in 500 mL of CH ₂ Cl ₂ under a nitrogen atmosphere. Trifluoroacetic acid (400 μL, 5.4 mmol) was added and stirred for 18 hours. Then chloranil (1.35 g, 5.4 mmol) was added and stirred for 4 hours. Then, Zn (OAc) ₂ (1.0 g, 5.4 mmol) was added and stirred for 1 hour. The reaction mixture was washed with water and dried by adding anhydrous Na ₂ SO ₄ . After the solvent was distilled off by an evaporator, the residue was purified by silica gel chromatography (eluent is n-hexane: CH ₂ Cl ₂ = 1: 1 volume ratio), recrystallized in MeOH / CH ₂ Cl ₂ , Compound 6 was obtained (0.26 g, yield: 20%).
¹ H NMR (400 MHz, CDCl ₃ ): δ / ppm 7.91 (8H, d, J = 4.1 Hz), 8.08 (8H, d, J = 4.1 Hz), 8.95 (8H, s) MS (FAB MS) ( m / z _calcd = 993.8); m / z _found : 994.

<Synthesis of Ligand L5>
Compound 6 porphyrin (150 mg, 0.15 mmol), compound 4 dipyrine (560 mg, 1.5 mmol), Pd (PPh ₃ ) ₂ Cl ₂ (35 mg, 0.05 mmol), K ₂ CO ₃ (275 mg, 2 mmol) and PPh ₃ (170 mg, 0.65 mmol) was dissolved in a mixed solvent of DMSO (30 mL) and H ₂ O (0.06 mL) (= 500: 1 volume ratio). This solution was freeze degassed (3 cycles) and stirred at 80 ° C. under a nitrogen atmosphere for 4 days. The reaction mixture was diluted with 300 mL of water and extracted with CH ₂ Cl ₂ (50 mL × 6 times). The organic phase was dried over anhydrous Na ₂ SO ₄ and the solution was concentrated under reduced pressure to give a purple solid. This solid was washed with MeOH to obtain the ligand L5 (73 mg, yield: 30%).
¹ H NMR (500 MHz, CDCl ₃ ): δ / ppm 2.50 (24 H, s), 6.24 (8H, d, J = 3.0 Hz), 6.66 (8H, d, J = 3.7 Hz), 7.70 (8H, d, J = 6.9 Hz), 8.00 (8H, d, J = 8.1 Hz), 8.07 (8H, d, J = 6.9 Hz), 8.35 (8H, d, J = 7.9 Hz), 9.02 (8H, s) .
¹³ C NMR (125 MHz, CDCl ₃ ): δ / ppm 16.39, 117.57, 120.28, 125.00, 126.38, 129.04, 131.59, 131.75, 136.74, 138.13, 139.13, 141.07, 142.93, 150.06, 153.91

<Nanosheet synthesis (3)>
1.7 mg of ligand L5 was dissolved in 10 mL of dichloromethane containing 1% by volume of pyridine to prepare a solution of ligand L5 in dichloromethane. After 10 mL of pure water was gently piled on the dichloromethane solution in the vial so that the separation of the aqueous phase and the organic phase was maintained, an additional 10 mL of 0.2 mM zinc acetate (II) aqueous solution was gently added. Piled up. When allowed to stand for 2 days, a green thin insoluble sheet was formed at the interface between the aqueous phase and the organic phase. After diluting the aqueous phase with pure water and the organic phase with CH ₂ Cl ₂ , the aqueous phase was removed with a pipette. After filtration, the sheet was washed with pure water, MeOH and CH ₂ Cl ₂ and dried in vacuum.

  FIGS. 14 and 15 show spectrum charts of X-ray photoelectron spectroscopy (XPS) of the nanosheet synthesized with the ligand L5, respectively. In the XPS of the ligand L5, two nitrogen 1s peaks of 398.0 eV and 399.7 eV are observed, but in the nanosheet XPS, a peak intensity of 398.2 eV is greatly observed. When the peak area ratio of the spectrum of nitrogen and zinc was calculated, nitrogen: zinc = 14: 1 (calculated value 12: 1) in the ligand L5, and nitrogen: zinc = 6: 1, (calculated value 4: 1) in the nanosheet. It is possible to confirm the complex formation of the zinc ion of the ligand L5 in the nanosheet synthesized from these. Here, it is considered that the peak area ratio of nitrogen is larger than the calculation because pyridine used for dissolving the ligand is coordinated to zinc as an axial ligand. The nanosheet is a complex polymer having the ligand L5 and can be determined to have a square network molecular structure.

  When the film thickness of the sheet was measured by AFM, it was confirmed that the thickness was about 20 nm on average. The film thickness was measured on a flat portion avoiding the edge and wrinkle portion of the film. This thickness value indicates that the obtained nanosheet is multilayer.

(Example 6)
In order to measure the photoelectric conversion characteristics of the nanosheet according to the present invention, nanosheets of Samples 1 to 5 were prepared by the following procedure.

<Sample 1: 4-layer nanosheet>
To a 50 mL glass vial was added 30 mL of aqueous zinc (II) acetate (50 mM, Zn (OAc) ₂ .2H ₂ O 0.3292 g). 7.4 × 10 ⁻⁵ mol / L solution of ligand L1 shown in Example 1 (7.4 × 10 ⁻⁴ g of ligand is dissolved in 6.0 mL dichloromethane + 0.3 mL ethyl acetate) 20 μL ( (Corresponding to the amount of nanosheets for 4 layers) was gently sprayed on the water surface in a glass vial and allowed to stand for 4 hours to form nanosheets. Thereafter, the nanosheet was transferred by bringing the SnO ₂ substrate into contact with the water surface for 1 minute by the Langmuir-Schaefer method. Further, after lifting the transferred substrate, the substrate was washed in sequence using pure water, ethanol, and dichloromethane to prepare Sample 1. The thickness of sample 1 is estimated to be about 4.8 nm or less).

<Sample 2: Multi-layered nanosheet>
Nanosheets were synthesized and laminated using an LB film creation apparatus (KSV NIMA, model KSV NIMA Small, hereinafter the same). First, the Wilhelmi plate used for measurement of trough, barrier and surface pressure of the LB film forming apparatus was washed with ethanol and pure water, and 60 mL of zinc acetate (II) aqueous solution (50 mM, Zn ( The trough was filled with OAc) ₂ · 2H ₂ O 0.6584 g). A very small amount of zinc acetate aqueous solution was removed from the water surface on the trough together with dust and dirt, and the area of the trough was changed to 69.75 cm ² (corresponding to 90% of the maximum area of the trough). Thereafter, a 7.5 × 10 ⁻⁴ mol / L solution of the ligand L1 shown in Example 1 (dissolve 1.27 × 10 ⁻³ g of ligand in 950 μL of dichloromethane + 50 μL of ethyl acetate) 16. 5 μL was gently spread on the water surface of the trough and allowed to stand for 18 hours to form a nanosheet. Thereafter, under a surface pressure of 1.83 mN / m (surface pressure after standing for 18 hours), the nanosheet is formed by bringing the SnO ₂ substrate into contact with the water surface for 1 minute by the LS method (in a state parallel to the water surface). The substrate was transferred and washed with pure water, ethanol, and dichloromethane in order. By repeating this process 6 times, multiple layers of nanosheets were formed to prepare Sample 2. The average number of layers of sample 2 was calculated by observing visible light absorption and found to be 27 (absorbance 0.00197 per single layer, sample absorbance 0.0530, estimated thickness about 32 nm).

<Sample 3: Multi-layered nanosheet>
Nanosheets were synthesized and laminated using an LB film forming apparatus. First, the Wilhelmi plate used for measurement of trough, barrier and surface pressure of the LB film forming apparatus was washed with ethanol and pure water, and 60 mL of zinc acetate (II) aqueous solution (50 mM, Zn ( The trough was filled with OAc) ₂ · 2H ₂ O 0.6584 g). A very small amount of zinc acetate aqueous solution was removed from the water surface on the trough together with dust and dirt on the water surface, and the area of the trough was changed to 69.75 cm ² (corresponding to 90% of the maximum area of the trough). Thereafter, a 7.5 × 10 ⁻⁴ mol / L solution of the ligand L1 shown in Example 1 (dissolve 1.27 × 10 ⁻³ g of ligand in 950 μL of dichloromethane + 50 μL of ethyl acetate) 16. 5 μL was gently sprayed on the water surface of the trough and left for 4 hours to form a nanosheet. Then, under a surface pressure of 1.83 mN / m (surface pressure after standing for 4 hours), the nanosheet is formed by bringing the SnO ₂ substrate into contact with the water surface for 1 minute by the LS method (in a state parallel to the water surface). After the transfer, the substrate was sequentially washed with pure water, ethanol, and dichloromethane to reduce the trough area by 2 cm ² (corresponding to the substrate area). This process was repeated 8 times. In order to further increase the number of layers, the following work was performed. In the same process as described above, the ligand solution was gently sprayed on the surface of the trough (spraying amount: 22.0 μL) and left for 22 hours to form a nanosheet. Thereafter, under the surface pressure of 1.83 mN / m (surface pressure after standing for 22 hours), the SnO ₂ substrate on which the multi-layered nanosheet obtained in the above step was formed was subjected to the LS method (in a state parallel to the water surface). ) To achieve further multi-layering of nanosheets by bringing them into contact with the water surface for 1 minute. The substrate was sequentially washed with pure water, ethanol, and dichloromethane to reduce the trough area by 2 cm ₂ (corresponding to the substrate area). Sample 3 was obtained by repeating this process nine times. The average number of layers of Sample 3 was calculated by observing visible light absorption, and found to be 36 (absorbance per single layer 0.00197, sample absorbance 0.0720, estimated thickness about 43 nm).

<Sample 4: Multi-layered nanosheet>
Nanosheets were synthesized and laminated using an LB film forming apparatus. First, the Wilhelmi plate used for measurement of trough, barrier and surface pressure of the LB film forming apparatus was washed with ethanol and pure water, and 60 mL of zinc acetate (II) aqueous solution (50 mM, Zn ( The trough was filled with OAc) ₂ · 2H ₂ O 0.6584 g). A very small amount of zinc acetate aqueous solution was removed from the water surface on the trough together with dust and dirt, and the area of the trough was changed to 69.75 cm ² (corresponding to 90% of the maximum area of the trough). Thereafter, the same ligand L1 as in Example 1 in a 7.5 × 10 ⁻⁴ mol / L solution (1.27 × 10 ⁻³ g of the ligand is dissolved in 950 μL of dichloromethane + 50 μL of ethyl acetate) 22.0 μL Was gently sprayed on the surface of the trough and allowed to stand for 17 hours. Then, under a surface pressure of 0.45 mN / m (surface pressure after standing for 17 hours), the nanosheet was formed by bringing the SnO ₂ substrate into contact with the water surface for 1 minute by the LS method (in a state parallel to the water surface). The substrate was transferred and washed with pure water, ethanol, and dichloromethane in order. This process was repeated 10 times. In order to further increase the number of layers, the following work was performed. In the same process as described above, the ligand solution was gently sprayed on the water surface of the trough (spraying amount 22.0 μL) and allowed to stand for 18 hours to form a nanosheet. Thereafter, the SnO ₂ substrate on which the multi-layered nanosheet obtained in the above step was formed under a surface pressure of 0.45 mN / m (surface pressure after standing for 18 hours) was subjected to the LS method (in a state parallel to the water surface). By making contact with the water surface for 1 minute, further multi-layering of nanosheets was realized. The substrate was sequentially washed with pure water, ethanol, and dichloromethane. Sample 4 was obtained by repeating this process 16 times. The average number of layers of sample 4 was calculated by observing visible light absorption and found to be 73 (absorbance per single layer 0.00197, sample absorbance 0.143, estimated thickness about 88 nm).

<Sample 5: Multilayer nanosheet>
10 mL of the same ligand L1 dichloromethane solution (1.0 × 10 ⁻⁴ mol / L, 8.2 × 10 ⁻⁴ g) as in Example 1 was added to a 50 mL glass vial, and 10 mL of pure water was further added to form an organic solution. A two-phase interface separated into a layer and an aqueous layer was formed. After standing for 2 hours, an aqueous solution of zinc (II) acetate (100 mM, Zn (OAc) ₂ .2H ₂ O 0.6584 g) was added. It left still in this state for 4 days, and the production | generation of the nanosheet on the interface was confirmed. The operation of removing the aqueous layer portion and adding pure water was performed 5 times, and further the operation of removing the organic layer portion and adding dichloromethane to the organic layer was performed twice. Sample 5 was then obtained by placing the generated nanosheet on the SnO ₂ substrate. When the average number of layers of sample 5 was calculated by observing visible light absorption, it was 243 (absorbance per single layer 0.00197, absorbance of sample 0.4796, estimated thickness about 292 nm).

<Sample 6: multilayer nanosheet using ligand L5>
1.7 mg of ligand L5 was dissolved in 10 mL of dichloromethane containing 1% by volume of pyridine to prepare a solution of ligand L5 in dichloromethane. After 10 mL of pure water was gently piled on the dichloromethane solution in the vial so that the separation of the aqueous phase and the organic phase was maintained, an additional 10 mL of 0.2 mM zinc acetate (II) aqueous solution was gently added. Piled up. When allowed to stand for 2 days, a green thin insoluble sheet was formed at the interface between the aqueous phase and the organic phase. After diluting the aqueous phase with pure water and the organic phase with CH ₂ Cl ₂ , the aqueous phase was removed with a pipette. After filtration, the sheet was washed with pure water, MeOH and CH ₂ Cl ₂ and dried in vacuum. Sample 6 was then obtained by placing the generated nanosheet on the SnO ₂ substrate. The thickness of the nanosheet is estimated to be 20 nm.

<Photocurrent measurement procedure>
Photocurrent was measured for all the samples 1 to 6 by the method described below. As an electrolyte solution, 12 mL of a mixed solution of tetrabutylammonium perchlorate (0.10 M) and a sacrificial reagent triethanolamine (0.05 M) was prepared (0.4103 g of tetrabutylammonium perchlorate and 0.0894 g of triethanolamine). . A mixed solution is added to the cell, and a SnO ₂ substrate (any one of Sample 1 to Sample 6) to which the nanosheet is transferred as a working electrode, a silver wire as a reference electrode and a three-electrode system using a platinum electrode as a counter electrode is set And bubbled with argon gas for 30 minutes.

Thereafter, the working electrode was irradiated with light and the photocurrent was observed. The photocurrent was observed by repeating on / off of light for 25 seconds, and the potential applied to the working electrode was 0 V with respect to the silver wire. It was also confirmed that the oxidation current of triethanolamine did not flow as a dark current even when a potential of 0 V was applied to the working electrode with respect to the silver wire. Sample 1-5 was irradiated with 500 nm monochromatic light. Sample 6 was irradiated with 450 nm monochromatic light. For sample 1, the irradiation current dependence (400 nm, 450 nm, 500 nm, 550 nm, 600 nm) of the photocurrent value was measured. With respect to Samples 2 and 4, photocurrent observation at an absorption wavelength of 500 nm was repeatedly performed, and durability measurement was performed. For Samples 2, 3, 4, and 5, the quantum yield and external quantum efficiency for monochromatic light of 500 nm were calculated. Further, the photocurrent was also observed for the SnO ₂ substrate on which the sample was not transferred, and it was clarified that no photocurrent was observed. The photocurrent was detected and data was acquired with ALS 650DT (manufactured by BAS). A HIGH POWER xenon light source MAX302 (Asahi Spectroscopic Co., Ltd.) was used as the light source, and the company's catalog value was adopted as the intensity of monochromatic light.

<Photocurrent measurement results>
Sample 1
The results are shown in FIG. When light of each wavelength was irradiated for 25 seconds and the photocurrent immediately before the end of the light irradiation was measured, the photocurrent of 13.3 nA was irradiated by the light irradiation of 400 nm, the photocurrent of 17.1 nA by the light irradiation of 450 nm, and the light current of 30 by the light irradiation of 500 nm. Photocurrents of 0.5 nA and 5.0 nA were observed by irradiation with light of 5 nA and 550 nm, and 5.0 nA and 600 nm, respectively. FIG. 24 also shows a graph showing a change in photocurrent flowing in response to light on / off for light irradiation of 500 nm.

Sample 2
The results are shown in FIG. 25 (first 4 iterations) and FIG. 26 (overall). A photocurrent of 126 nA was detected at the beginning of observation (immediately before the end of the first light irradiation) by measuring the photocurrent by irradiation with light of 500 nm. In this case, the quantum yield was 67.2%, and the external quantum efficiency was 7.77%. Further, a photocurrent of 27.8 nA was observed after 132 on / off repeated measurements, and the amount of current became constant. The decrease in the current value is due to physical peeling of the nanosheet, and it is considered that a more stable photocurrent can be taken out by improving the immobilization method with the electrode.

Sample 3
The results are shown in FIG. A photocurrent of 131 nA was detected at the beginning of observation (immediately before the end of the first light irradiation) by measuring the photocurrent by irradiation with light of 500 nm. In this case, the quantum yield was 52.5%, and the external quantum efficiency was 8.08%.

Sample 4
The results are shown in FIG. 28 (first 4 repetitions) and FIG. 29 (overall). A photocurrent of 114 nA was detected at the beginning of observation (immediately before the end of the first light irradiation) by measuring the photocurrent by irradiation with light of 500 nm. At this time, the quantum yield was 24.9%, and the external quantum efficiency was 7.03%. Further, after 130 on / off repeated measurements, a photocurrent of 18.1 nA was observed, and the amount of current became constant. The decrease in the current value is due to physical peeling of the nanosheet, and it is considered that a more stable photocurrent can be taken out by improving the immobilization method with the electrode.

Sample 5
The results are shown in FIG. A photocurrent of 0.86 nA was detected at the initial stage of observation (immediately before the end of the first light irradiation) by measuring the photocurrent by irradiation with light of 500 nm. In this case, the quantum yield was 0.079%, and the external quantum yield was 0.053%.

Sample 6
The results are shown in FIG. A photocurrent of 6.9 nA was detected at the initial stage of observation (immediately before the end of the first light irradiation) by measuring the photocurrent by light irradiation at 450 nm.

Claims (14)

A metal complex polymer sheet, the metal complex polymer comprising a dipyrine derivative represented by formula (i) and a central metal, wherein the central metal is Fe, Mn, Zn, Ni, Pd, Pt, Cd, Hg, Hexagonal shape which is Co, Au, Ag, Sn, Pb or Cu, the dipyrine derivatives are linked to each other by coordination of the two dipyrine derivatives to one central metal, and the coupling is repeated. A sheet with a network molecular structure.
Each Y is a monovalent group represented by formula (ii), each L independently represents a divalent linking group, each R ¹ independently represents a hydrogen atom or a substituent, and adjacent R ¹ may be bonded to each other to form a ring, and each X independently represents a carbon atom or a nitrogen atom, and R ¹ bonded to X does not exist when X represents a nitrogen atom. A metal complex polymer sheet, the metal complex polymer comprising a dipyrine derivative represented by formula (iii) and a central metal, wherein the central metal is Fe, Mn, Zn, Ni, Pd, Pt, Cd, Hg, Hexagonal shape which is Co, Au, Ag, Sn, Pb or Cu, the dipyrine derivatives are linked to each other by coordination of the two dipyrine derivatives to one central metal, and the coupling is repeated. A sheet with a network molecular structure.
Each Y is a monovalent group represented by the formula (ii), each L independently represents a divalent linking group, A represents a nitrogen atom or a boron atom, and each R ¹ independently represents hydrogen. It represents an atom or a substituent, and adjacent R ^{1 's} may combine to form a ring. A metal complex polymer sheet, the metal complex polymer comprising a dipyrine derivative represented by formula (iv) and a central metal, wherein the central metal is Fe, Mn, Zn, Ni, Pd, Pt, Cd, Hg, It is Co, Au, Ag, Sn, Pb or Cu, and the dipyrine derivatives are linked to each other by coordination of the two dipyrine derivatives to one central metal, and the triangular shape is constructed by repeating the coupling A sheet with a network molecular structure.
Each Y is a monovalent group represented by formula (ii), each L independently represents a divalent linking group, each R ¹ independently represents a hydrogen atom or a substituent, and adjacent R ¹ may combine to form a ring. A metal complex polymer sheet, the metal complex polymer comprising a dipyrine derivative represented by formula (v) and a central metal, wherein the central metal is Fe, Mn, Zn, Ni, Pd, Pt, Cd, Hg, Co, Au, Ag, Sn, Pb or Cu, and the dipyrine derivatives are linked to each other by coordination of the two dipyrine derivatives to one central metal, and are formed by repeating the coupling. A sheet with a network molecular structure.

Each Y is a monovalent group represented by formula (ii), each L independently represents a divalent linking group, each R ¹ independently represents a hydrogen atom or a substituent, and adjacent R ¹ may be bonded to each other to form a ring, Q represents a hydrogen atom or a metal atom, Z represents a counter ion or an axial ligand, and n represents an integer of 0 or more.   Each L is the same, and is selected from the group consisting of a substituted or unsubstituted p-phenylene group, a substituted or unsubstituted 4,4′-biphenylylene group, a substituted or unsubstituted alkenylene group, and a substituted or unsubstituted alkynylene group. The sheet according to any one of claims 1 to 4, which is selected.   The sheet according to any one of claims 1 to 5, wherein each L is a substituted or unsubstituted p-phenylene group. Sheet described in each R ¹ is any one of claims 1 to 6 is a hydrogen atom. The sheet according to any one of claims 1 to 7 , having an average thickness of 0.5 nm to 100 µm.   A dipyrine derivative 1 represented by the formula (i) according to claim 1, the formula (iii) according to claim 2, the formula (iv) according to claim 3, or the formula (v) according to claim 4. By continuing the contact between the organic phase containing at least one species and the aqueous phase containing at least one selected from a metal complex and salt as a central metal while maintaining a phase-separated state, A method for producing a metal complex polymer sheet, comprising a step of growing a metal complex polymer in a sheet form at an interface between an organic phase and an aqueous phase.   A dipyrine derivative 1 represented by the formula (i) according to claim 1, the formula (iii) according to claim 2, the formula (iv) according to claim 3, or the formula (v) according to claim 4. One of the organic phase containing at least a species and the aqueous phase containing at least one selected from a metal complex and salt as a central metal is coated with the other phase, and the two phases are separated. A method for producing a metal complex polymer sheet, comprising a step of growing a metal complex polymer in a sheet form at a gas-liquid interface by continuing contact between the two while maintaining a dry state. The method according to claim 9 or 10 , wherein the growth time of the metal complex polymer is 1 second to 1 month. The method according to any one of claims 9 to 11 , wherein the metal complex polymer is grown for a time necessary for the average thickness of the sheet to be from 0.5 nm to 100 µm. After recovering metal complex polymer sheet after growth method according to any one of claims 9-1 2, including the step of flattening the sheet by heat treatment. The solar cell which used the sheet | seat as described in any one of Claims 1-8 for the light absorption layer.