Sheet and method for manufacturing the sheet

Abstract

To provide a sheet containing a coordination polymer and showing rectification characteristics, and to provide a manufacturing method of the same.SOLUTION: A sheet comprises: a coordination polymer-containing first layer containing a first central metal selected from a group consisting of Fe, Co, Ni, Cu and Zn, and a polydentate ligand that coordinates to the first central metal such as 1,3,5-tris-(4-(2,2':6',2"-terpyridyl) phenyl) benzene; and a coordination polymer-containing second layer containing a second central metal different from the first central metal, and selected from a group consisting of Fe, Co, Ni, Cu and Zn, and a polydentate ligand that coordinates to the second central metal such as 1,3,5-tris-(4-(2,2':6',2"-terpyridyl) phenyl) benzene.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a sheet and a method for manufacturing the sheet.

Background Art

[0002] A substance having a thickness on the order of nanometers and a two-dimensionally extended structure is called a nanosheet and is expected to be applied to electronic device materials. For example, nanosheets formed by coordination polymers have been actively studied. For example, a coordination polymer is known as a substance having a structure in which structural units formed by coordination of polydentate ligands to a central metal are continuously connected.

[0003] For example, Patent Document 1 below discloses an electrochromic sheet for an electrochromic device. The electrochromic sheet disclosed in Patent Document 1 below is formed of a metal complex polymer, and the metal complex polymer has a hexagonal network molecular structure constructed by repeating the connection of two terpyridine derivatives via one central metal.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Sheets formed by coordination polymers are expected to exhibit various functions depending on the combination of the central metal and the polydentate ligand. For example, the development of a nanosheet exhibiting rectifying characteristics can enhance the feasibility of applying nanosheets to electronic device materials. On the other hand, the electrochromic sheet disclosed in Patent Document 1 above does not exhibit desired rectifying characteristics.

[0006] An object of one embodiment of this disclosure is to provide a sheet containing a coordination polymer that exhibits rectifying properties. An object of other embodiments of this disclosure is to provide a method for producing a sheet containing a coordination polymer that exhibits rectifying properties. [Means for solving the problem]

[0007] This disclosure includes the following aspects: <1> A sheet comprising: a first layer containing a coordination polymer comprising a first central metal selected from the group consisting of Fe, Co, Ni, Cu, and Zn, and a polydentate ligand represented by the following formula (1) that coordinates to the first central metal; and a second layer containing a coordination polymer comprising a second central metal, different from the first central metal and selected from the group consisting of Fe, Co, Ni, Cu, and Zn, and a polydentate ligand represented by the following formula (1) that coordinates to the second central metal.

[0008] [ka]

[0009] In formula (1), each R 1 Each R independently represents a divalent linking group, 2 R independently represents a hydrogen atom or substituent, and adjacent R 2 They may bond together to form a ring, and each X independently represents a carbon atom or a nitrogen atom, with R bonded to the X representing a nitrogen atom. 2 It does not exist.

[0010] <2> The above second layer is in contact with the above first layer. <1> The sheet described above. <3> At the interface between the first layer and the second layer, the polydentate ligand represented by formula (1) is coordinated to the first central metal and the second central metal. <2> The sheet described above. <4> In at least one layer selected from the group consisting of the first layer and the second layer, the metal elements detected by energy-dispersive X-ray spectroscopy include at least two metal elements selected from the group consisting of Fe, Co, Ni, Cu, and Zn. <1> ~ <3> The sheet listed in one of the following options. <5> In the first layer described above, the metal elements detected by energy-dispersive X-ray spectroscopy include the metal elements constituting the first central metal and the metal elements constituting the second central metal. <1> ~ <4> The sheet listed in one of the following options. <6> In the second layer described above, the metal elements detected by energy-dispersive X-ray spectroscopy include the metal elements constituting the first central metal and the metal elements constituting the second central metal. <1> ~ <5> The sheet listed in one of the following options. <7> The first central metal is Fe, and the second central metal is Co. <1> ~ <6> The sheet listed in one of the following options. <8> The first central metal is Co, and the second central metal is Fe. <1> ~ <7> The sheet listed in one of the following options. <9> The average thickness of the first layer is 1 nm to 1,000 nm, and the average thickness of the second layer is 1 nm to 1,000 nm. <1> ~ <8> The sheet listed in one of the following options. <10> Each of the above R in equation (1) 1 However, it is a substituted or unsubstituted arylene group or a substituted or unsubstituted heteroarylene group. <1> ~ <9> The sheet listed in one of the following options. <11> Each of the above R in equation (1) 2 However, independently, these are halogen atoms, substituted or unsubstituted monovalent hydrocarbon groups, hydroxyl groups, substituted or unsubstituted hydrocarbon oxy groups, carboxyl groups, substituted or unsubstituted hydrocarbon carbonyl groups, cyano groups, amino groups, substituted or unsubstituted hydrocarbon monosubstituted amino groups, substituted or unsubstituted hydrocarbon disubstituted amino groups, sulfo groups, substituted or unsubstituted monovalent heterocyclic groups, or hydrogen atoms. <1> ~ <10> The sheet listed in one of the following options. <12> Each of the above R in equation (1) 2The sheet according to any one of <1> to <11>, wherein the atom is a hydrogen atom. <13> Contacting an organic phase containing a multidentate ligand represented by the following formula (1) with an aqueous phase containing a first precursor that supplies a first central metal selected from the group consisting of Fe, Co, Ni, Cu, and Zn; reacting the multidentate ligand and the first precursor at the interface between the organic phase and the aqueous phase to form a first layer containing a coordination polymer including the first central metal and the multidentate ligand coordinated to the first central metal; replacing at least a part of the aqueous phase with an aqueous phase containing a second precursor that supplies a second central metal selected from the group consisting of Fe, Co, Ni, Cu, and Zn, which is different from the first central metal; and reacting the multidentate ligand and the second precursor at the interface between the organic phase and the aqueous phase containing the second precursor to form a second layer containing a coordination polymer including the second central metal and the multidentate ligand coordinated to the second central metal. A method for manufacturing a sheet including these steps.

[0011]

Chemical formula

[0012] In formula (1), each R 1 independently represents a divalent linking group, each R 2 independently represents a hydrogen atom or a substituent, adjacent Rs 2 may combine with each other to form a ring, each X independently represents a carbon atom or a nitrogen atom, and R 2 bonded to X representing a nitrogen atom does not exist.

Advantages of the Invention

[0013] According to one embodiment of the present disclosure, a sheet containing a coordination polymer that exhibits rectifying characteristics is provided. According to another embodiment of the present disclosure, a method for manufacturing a sheet containing a coordination polymer that exhibits rectifying characteristics is provided.

Brief Description of the Drawings

[0014] [Figure 1]Figure 1 shows the current-voltage characteristics in Example 1. [Figure 2] Figure 2 shows the current-voltage characteristics in Example 2. [Figure 3] Figure 3 shows the current-voltage characteristics in Example 3. [Figure 4] Figure 4 shows the current-voltage characteristics in Comparative Example 1. [Figure 5] Figure 5 shows the current-voltage characteristics in Comparative Example 2. [Modes for carrying out the invention]

[0015] The embodiments of this disclosure are described in detail below. This disclosure is not limited to the embodiments described below. The embodiments described below may be modified as appropriate within the scope of the purposes of this disclosure.

[0016] In this disclosure, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively.

[0017] In numerical ranges described in stages within this disclosure, the upper limit stated in one numerical range may be replaced by the upper limit of another numerical range described in stages, and the lower limit stated in one numerical range may be replaced by the lower limit of another numerical range described in stages. In numerical ranges described in stages within this disclosure, the upper or lower limit stated in one numerical range may be replaced by the values ​​shown in the examples.

[0018] In this disclosure, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes if the intended purpose is achieved.

[0019] In this disclosure, if there are multiple substances corresponding to each component in a composition, unless otherwise specified, the amount of each component in the composition means the total amount of the multiple substances present in the composition.

[0020] In this disclosure, a preferred combination of embodiments is a more preferred embodiment.

[0021] In this disclosure, ordinal numbers (e.g., "1st" and "2nd") are terms used to distinguish elements and do not limit the number of elements or their relative importance.

[0022] <Sheet> The sheet relating to this disclosure will be described below. In one embodiment of this disclosure, the sheet includes a first layer and a second layer. The first layer includes a coordination polymer comprising a first central metal selected from the group consisting of Fe, Co, Ni, Cu, and Zn, and a polydentate ligand represented by the following formula (1) that coordinates to the first central metal. The second layer includes a coordination polymer comprising a second central metal, which is different from the first central metal and is selected from the group consisting of Fe, Co, Ni, Cu, and Zn, and a polydentate ligand represented by the following formula (1) that coordinates to the second central metal. In this disclosure, "second central metal different from the first central metal" means that the types of elements constituting the second central metal are different from the types of elements constituting the first central metal. For example, if the first central metal is Fe, the second central metal is selected from Co, Ni, Cu, and Zn.

[0023] [ka]

[0024] In formula (1), each R 1 Each R independently represents a divalent linking group, 2 R independently represents a hydrogen atom or substituent, and adjacent R 2 They may bond together to form a ring, and each X independently represents a carbon atom or a nitrogen atom, with R bonded to the X representing a nitrogen atom. 2 It does not exist.

[0025] According to one embodiment described above, a sheet containing a coordination polymer exhibiting rectification characteristics is provided. The manifestation of rectification characteristics is presumed to be due to the difference in the electrochemical behavior of the coordination polymer in the first layer and the electrochemical behavior of the coordination polymer in the second layer. The type of first central metal in the coordination polymer in the first layer is different from the type of second central metal in the coordination polymer in the second layer. Therefore, the coordination polymer containing the first central metal in the first layer can exhibit different electrochemical behavior from the coordination polymer containing the second central metal in the second layer. Examples of electrochemical behavior include oxidation-reduction properties. It is thought that the difference in electrochemical behavior described above makes it easier for current to flow from one layer to the other, thereby obtaining rectification characteristics.

[0026] [First layer] The first layer comprises a coordination polymer containing a first central metal selected from the group consisting of Fe, Co, Ni, Cu, and Zn, and a polydentate ligand represented by formula (1) that coordinates to the first central metal.

[0027] From the viewpoint of rectification characteristics, the first central metal is preferably selected from the group consisting of Fe, Co, and Ni, and more preferably selected from the group consisting of Fe and Co. From the viewpoint of rectification characteristics, the first central metal is preferably Fe, Co, or Ni, and more preferably Fe or Co.

[0028] The oxidation number of the first central metal may be determined according to the type of the first central metal, the type of the second central metal, and the oxidation number of the second central metal. Examples of oxidation numbers for the first central metal include monovalent, divalent, and trivalent. The oxidation number of Fe is preferably divalent. The oxidation number of Co is preferably divalent. The oxidation number of Ni is preferably divalent. The oxidation number of Cu is preferably divalent. The oxidation number of Zn is preferably divalent.

[0029] In formula (1), each R 1 R independently represents a divalent linking group. Hereafter, R 1 I will explain the specific details of this aspect.

[0030] R 1 Examples of divalent linking groups represented by the formulas (A-1) to (A-7) below include substituted or unsubstituted divalent hydrocarbon groups and divalent linking groups represented by the formulas (A-1) to (A-7) below. Substituted or unsubstituted divalent hydrocarbon groups, divalent linking groups represented by the formula (A-1), divalent linking groups represented by the formula (A-2), divalent linking groups represented by the formula (A-3), divalent linking groups represented by the formula (A-6) and divalent linking groups represented by the formula (A-7) below are preferred, substituted or unsubstituted divalent hydrocarbon groups, divalent linking groups represented by the formula (A-1), divalent linking groups represented by the formula (A-2) and divalent linking groups represented by the formula (A-3) below are more preferred, and substituted or unsubstituted divalent hydrocarbon groups are even more preferred.

[0031] [ka]

[0032] In formulas (A-1) to (A-7), each R d * independently represents a hydrogen atom or a substituent. Examples of substituents include R, which will be discussed later. 2 Examples of substituents represented by each R d Each of these atoms is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and even more preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

[0033] Examples of substituted or unsubstituted divalent hydrocarbon groups include substituted or unsubstituted divalent saturated hydrocarbon groups and substituted or unsubstituted divalent unsaturated hydrocarbon groups. Substituted or unsubstituted divalent unsaturated hydrocarbon groups are preferred. From the viewpoint of shape regularity and stability of the coordination polymer, it is preferable that the two bonding sites in the divalent hydrocarbon group are located at opposite positions that are furthest apart from each other (for example, the para position in an aromatic ring).

[0034] Examples of substituted or unsubstituted divalent saturated hydrocarbon groups include substituted or unsubstituted alkylene groups and substituted or unsubstituted heteroalkylene groups. A "heteroalkylene group" means an alkylene group containing a heteroatom. The number of carbon atoms in the above saturated hydrocarbon group is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3.

[0035] Examples of alkylene groups include ethylene, propylene, trimethylene, tetramethylene, hexamethylene, 2-ethylhexamethylene, octamethylene, and decamethylene. Furthermore, examples of alkylene groups include cyclic alkylene groups such as cyclohexylene.

[0036] Examples of heteroalkylene groups include methyleneoxymethylene group, methyleneoxyethylene group, ethyleneoxyethylene group, ethyleneoxymethyleneoxyethylene group, methylenethiomethylene group, methylenethioethylene group, and ethylenethioethylene group.

[0037] Examples of substituted or unsubstituted divalent unsaturated hydrocarbon groups include substituted or unsubstituted alkenylene groups, substituted or unsubstituted heteroalkenylene groups, substituted or unsubstituted alkylylene groups, and substituted or unsubstituted heteroalkylylene groups. "Heteroalkenylene group" means an alkenylene group containing a heteroatom. "Heteroalkylylene group" means an alkylylene group containing a heteroatom. The number of carbon atoms in the above unsaturated hydrocarbon groups is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3.

[0038] Examples of alkenylene groups and alkynylene groups include ethene-1,2-diyl group (-CH=CH- group), 2-butene-1,4-diyl group (-CH2-CH=CH-CH2- group), and ethyne-1,2-diyl group (-C≡C- group).

[0039] Examples of heteroalkenylene groups include the -CH=CH-O-CH=CH- group.

[0040] Examples of heteroalkylene groups include the -C≡C-O-C≡C- group.

[0041] Examples of substituted or unsubstituted divalent unsaturated hydrocarbon groups include substituted or unsubstituted arylene groups and substituted or unsubstituted heteroarylene groups. A "heteroarylene group" means an arylene group containing a heteroatom. The number of carbon atoms in the above unsaturated hydrocarbon groups is preferably 6 to 18, more preferably 6 to 12, and even more preferably 6 to 8.

[0042] Examples of arylene groups include phenylene groups, biphenylene groups, naphthylene groups, and anthrylene groups.

[0043] Examples of heteroarylene groups include pyridylene groups, pyrimidylene groups, dibenzofuranylene groups, and dibenzothiophenylene groups.

[0044] Examples of substituted or unsubstituted divalent unsaturated hydrocarbon groups include substituted or unsubstituted aralkylene groups and substituted or unsubstituted heteroaralkylene groups. A "heteroaralkylene group" means an aralkylene group containing a heteroatom. The number of carbon atoms in the above unsaturated hydrocarbon groups is preferably 7 to 20, more preferably 7 to 12, and even more preferably 7 to 9.

[0045] Examples of aralkylene groups include benzylidene groups such as styrene groups, cinnamyridene groups, torylene groups, and xylylene groups.

[0046] Examples of heteroaralkylene groups include the 2,6-pyridylenedimethylene group and the 2,5-thionylenedimethylene group.

[0047] From the viewpoint of structure and chemical stability, among substituted or unsubstituted divalent unsaturated hydrocarbon groups, substituted or unsubstituted arylene groups and substituted or unsubstituted heteroarylene groups are preferred.

[0048] Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms. One or more types of heteroatoms may be used.

[0049] Divalent hydrocarbon groups may have substituents. Examples of substituents include halogen atoms such as fluorine, chlorine, and bromine; alkoxy groups with 1 to 4 carbon atoms such as methoxy, ethoxy, and propoxy groups; alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, isopropoxycarbonyl, n-butoxycarbonyl, and t-butoxycarbonyl groups; and cyano groups.

[0050] In formula (1), each R 2 R independently represents a hydrogen atom or a substituent. Hereafter, R 2 I will explain the specific details of this aspect.

[0051] R 2Substituents represented by -P(=O)(OH)2 include, for example, halogen atoms, substituted or unsubstituted monovalent hydrocarbon groups, mercapto groups, carbonyl mercapto groups, thiocarbonyl mercapto groups, substituted or unsubstituted hydrocarbon thio groups, substituted or unsubstituted hydrocarbon thiocarbonyl groups, substituted or unsubstituted hydrocarbon dithio groups, hydroxyl groups, substituted or unsubstituted hydrocarbon oxy groups, carboxyl groups, formyl groups, substituted or unsubstituted hydrocarbon carbonyl groups, substituted or unsubstituted hydrocarbon oxycarbonyl groups, substituted or unsubstituted hydrocarbon carbonyloxy groups, cyano groups, nitro groups, amino groups, substituted or unsubstituted hydrocarbon monosubstituted amino groups, substituted or unsubstituted hydrocarbon disubstituted amino groups, phosphino groups, substituted or unsubstituted hydrocarbon monosubstituted phosphino groups, substituted or unsubstituted hydrocarbon disubstituted phosphino groups, groups represented by -P(=O)(OH)2, carbamoyl groups, and substituted or unsubstituted hydrocarbon monosubstituted groups. Examples include carbamoyl groups, substituted or unsubstituted disubstituted carbamoyl groups of hydrocarbons, groups represented by -B(OH)2, boric acid ester residues, sulfo groups, substituted or unsubstituted sulfo groups of hydrocarbons, substituted or unsubstituted sulfonyl groups of hydrocarbons, substituted or unsubstituted monovalent heterocyclic groups, hydrocarbon groups having two or more ether bonds, hydrocarbon groups having two or more ester bonds, hydrocarbon groups having two or more amide bonds, groups represented by -CO2M, groups represented by -PO3M, groups represented by -PO2M, groups represented by -PO3M2, groups represented by -OM, groups represented by -SM, groups represented by -B(OM)2, groups represented by -SO3M, groups represented by -SO2M, groups represented by -NR3M', groups represented by -BR3M', groups represented by -PR3M', groups represented by -SR2M', and substituted or unsubstituted monovalent heterocyclic groups having a quaternized nitrogen atom in the heterocycle. M represents a metal cation or a substituted or unsubstituted ammonium cation. R represents a monovalent hydrocarbon group. M' represents an anion.

[0052] Each R 2Preferably, each R is independently a halogen atom, a substituted or unsubstituted monovalent 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, a substituted or unsubstituted hydrocarbon monosubstituted amino group, a substituted or unsubstituted hydrocarbon disubstituted amino group, a sulfo group, a substituted or unsubstituted monovalent heterocyclic group, or a hydrogen atom. 2 It is more preferable that each R independently be a halogen atom, a substituted or unsubstituted monovalent hydrocarbon group, a hydroxyl group, a carboxyl group, a cyano group, an amino group, a substituted or unsubstituted monovalent heterocyclic group, or a hydrogen atom. 2 It is more preferable that each R independently be a substituted or unsubstituted monovalent hydrocarbon group, a substituted or unsubstituted monovalent heterocyclic group, or a hydrogen atom. 2 Each R is preferably independently a substituted or unsubstituted monovalent hydrocarbon group or hydrogen atom. 2 It is most preferably a hydrogen atom.

[0053] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Fluorine, chlorine, and bromine atoms are preferred, and chlorine and bromine atoms are more preferred.

[0054] Examples of monovalent hydrocarbon groups include C1-C20 alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, nonyl, dodecyl, pentadecyl, octadecyl, and eicosyl groups; C3-C20 cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclononyl, cyclododecyl, norbornyl, and adamantyl groups; C2-C20 alkenyl groups such as ethenyl, propenyl, 3-butenyl, 2-butenyl, 2-pentenyl, 2-hexenyl, 2-nonenyl, and 2-dodecenyl groups; and phenyl, 1-naphthyl, 2-naphthyl, and 2-methyl groups. Examples include aryl groups with 6 to 20 carbon atoms, such as phenyl 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-adamantylphenyl group, and 4-phenylphenyl group; and aralkyl groups with 7 to 20 carbon atoms, such as 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, and 6-phenyl-1-hexyl group. Among the monovalent hydrocarbon groups described above, alkyl groups having 1 to 20 carbon atoms and aryl groups having 6 to 20 carbon atoms are preferred, alkyl groups having 1 to 12 carbon atoms and aryl groups having 6 to 18 carbon atoms are more preferred, and alkyl groups having 1 to 6 carbon atoms and aryl groups having 6 to 12 carbon atoms are even more preferred. At least one hydrogen atom of the monovalent hydrocarbon group (for example, one to three hydrogen atoms, preferably one or two hydrogen atoms) may be substituted with a substituent (hereinafter referred to as "substituent X").Examples of substituent X include halogen atoms such as fluorine, chlorine, and bromine; alkoxy groups with 1 to 4 carbon atoms such as methoxy, ethoxy, and propoxy groups; alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, isopropoxycarbonyl, n-butoxycarbonyl, and t-butoxycarbonyl groups; and cyano groups.

[0055] R 2 Examples of hydrocarbon groups included in substituents represented by (specifically, hydrocarbon thio groups, hydrocarbon thiocarbonyl groups, hydrocarbon dithio groups, hydrocarbon oxy groups, hydrocarbon carbonyl groups, hydrocarbon oxycarbonyl groups, hydrocarbon carbonyloxy groups, hydrocarbon monosubstituted amino groups, hydrocarbon disubstituted amino groups, hydrocarbon monosubstituted phosphino groups, hydrocarbon disubstituted phosphino groups, hydrocarbon monosubstituted carbamoyl groups, hydrocarbon disubstituted carbamoyl groups, hydrocarbon sulfo groups, hydrocarbon sulfonyl groups, groups represented by -NR3M', groups represented by -BR3M', groups represented by -PR3M', and groups represented by -SR2M') include the monovalent hydrocarbon groups described above. At least one hydrogen atom of the hydrocarbon group portion may be substituted by a substituent. Examples of substituents of the hydrocarbon group portion include substituent X.

[0056] Examples of borate ester residues include the group represented by the following formula.

[0057] [ka]

[0058] A monovalent heterocyclic group refers to the group of atoms remaining after removing one hydrogen atom from a heterocyclic compound. Examples of heterocyclic compounds include monocyclic heterocyclic compounds such as pyridine, 1,2-diazine, 1,3-diazine, 1,4-diazine, 1,3,5-triazine, furan, pyrrole, thiophene, pyrazole, imidazole, oxazole, thiazole, oxadiazole, thiadiazole, and azadiazole; condensed polycyclic heterocyclic compounds in which two or more heterocycles constituting a monocyclic heterocyclic compound are fused; bridged polycyclic heterocyclic compounds having a structure in which two heterocycles constituting a monocyclic heterocyclic compound are bridged by a divalent group such as a methylene group, an ethylene group, or a carbonyl group; and bridged polycyclic heterocyclic compounds having a structure in which one aromatic ring and one heterocycle constituting a monocyclic heterocyclic compound are bridged by a divalent group such as a methylene group, an ethylene group, or a carbonyl group. Pyridine, 1,2-diazine, 1,3-diazine, 1,4-diazine, and 1,3,5-triazine are preferred, and pyridine and 1,3,5-triazine are more preferred. The monovalent heterocyclic group may have substituents. Examples of substituents include the substituent X described above.

[0059] Examples of hydrocarbon groups having two or more ether bonds include the group represented by the following formula. In the following formula, each R' independently represents a substituted or unsubstituted divalent hydrocarbon group, and p is an integer of 2 or more.

[0060] [ka]

[0061] Examples of divalent hydrocarbon groups represented by R' include divalent saturated hydrocarbon groups with 1 to 20 carbon atoms, such as methylene, ethylene, 1,2-propylene, 1,3-propylene, 1,2-butylene, 1,3-butylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,9-nonylene, and 1,12-dodecylene; and aluminum hydrocarbon groups such as ethenylene, propenylene, 3-butenylene, 2-butenylene, 2-pentenylene, 2-hexenylene, 2-nonenylene, and 2-dodecenylene. Examples include divalent unsaturated hydrocarbon groups having 2 to 20 carbon atoms, such as kenylene and ethynylene; divalent cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cyclononylene, cyclododecylene, norvonylene, and adamantylene; and arylene groups having 6 to 20 carbon atoms, such as 1,3-phenylene, 1,4-phenylene, 1,4-naphthylene, 1,5-naphthylene, 2,6-naphthylene, and biphenyl-4,4'-diyl. At least one hydrogen atom of a divalent hydrocarbon group may be substituted with a substituent. Examples of substituents include the substituent X described above.

[0062] Examples of hydrocarbon groups having two or more ester bonds include the group represented by the following formula. In the following formula, R' is synonymous with R' as previously described, and p is synonymous with p as previously described.

[0063] [ka]

[0064] Examples of hydrocarbon groups having two or more amide bonds include the group represented by the following formula. In the following formula, R' is synonymous with R' as previously described, and p is synonymous with p as previously described.

[0065] [ka]

[0066] Examples of substituted or unsubstituted monovalent heterocyclic groups having a quaternary nitrogen atom within the heterocycle include the group represented by the following formula. In the following formula, R is synonymous with R as previously described, and M' is synonymous with M' as previously described.

[0067] [ka]

[0068] R 2 In the substituent represented by , the metal cation represented by M is preferably a monovalent to trivalent ion. Examples of metal cations include ions of metals such as Li, Na, K, Cs, Be, Mg, Ca, Ba, Ag, Al, Bi, Cu, Fe, Ga, Mn, Ni, Pb, Sn, Ti, V, W, Y, Yb, Zn, or Zr.

[0069] R 2 Examples of substituents for the ammonium cation represented by M in the substituent represented by include alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and t-butyl groups.

[0070] R 2 In the substituent represented by M', the anion represented by M' is, for example, F - Cl - , Br - , I - , OH - , - ClO2 - ClO3 - ClO4 - SCN - 5CN - NO3 - SO4 2- HSO4 - , PO4 3- HPO4 2- H2PO4 - BF4 - PF6 - CH3SO3 - CF3SO3 -Examples include tetrakis(imidazolyl)borate anion, 8-quinolinolatoanion, 2-methyl-8-quinolinolatoanion, and 2-phenyl-8-quinolinolatoanion.

[0071] In equation (1), adjacent R 2 The atoms may bond together to form a ring. The number of constituent atoms in the ring is preferably 5 to 10, more preferably 5 to 7, and even more preferably 6. From the viewpoint of expanding the conjugated system, the ring preferably contains π electrons. The ring preferably contains 2 or more π electrons. The ring is preferably an aromatic ring.

[0072] In formula (1), each X independently represents a carbon atom or a nitrogen atom, and R is bonded to X representing a nitrogen atom. 2 It does not exist. Each X is preferably a carbon atom.

[0073] The polydentate ligand represented by formula (1) coordinates to the first central metal in the coordination polymer. The polydentate ligand represented by formula (1) may coordinate to multiple first central metals. In other words, the coordination polymer may contain multiple first central metals. The coordination polymer may contain multiple polydentate ligands represented by formula (1).

[0074] From the viewpoint of rectification characteristics, it is preferable that the coordination polymer has a constituent unit represented by the following formula (2). The constituent unit represented by formula (2) corresponds to the smallest constituent unit formed by the coordination of the polydentate ligand represented by formula (1) to the first central metal.

[0075] [ka]

[0076] In formula (2), M 1 represents the first central metal, R 1 This is R in equation (1) described above. 1 It is synonymous with R 2 This is R in equation (1) described above. 2This is equivalent to the above, and X is equivalent to X in equation (1) described above.

[0077] From the viewpoint of rectification characteristics, the coordination polymer is preferably having a repeating structure of constituent units represented by formula (2). In each constituent unit of the repeating structure described above, M 1 It is bonded to the nitrogen atom of the terpyridine structure contained in the adjacent structural unit, and the nitrogen atom of the terpyridine structure is bonded to the M contained in the adjacent structural unit. 1 It is connected.

[0078] The coordination polymer preferably has a network structure comprising a first central metal and a polydentate ligand represented by formula (1) that coordinates to the first central metal. Furthermore, the coordination polymer preferably has a hexagonal network structure. For example, the smallest unit of the hexagonal network structure is constructed by six first central metals and six polydentate ligands represented by formula (1) that connect the first central metals. For example, the smallest unit of the hexagonal network structure is constructed by connecting three constituent units represented by formula (2). Specific examples of the smallest unit of the hexagonal network structure are shown below. In the following specific examples, the nitrogen atom of the terpyridine structure (specifically M) 1 Nitrogen atoms that are not coordinated to the first central metal may be further coordinated to other first central metals.

[0079] [ka]

[0080] The sheet may contain one or more first layers.

[0081] The average thickness of the first layer is not limited. The average thickness of the first layer may be determined according to the application. From the viewpoint of rectification characteristics and durability, the average thickness of the first layer is preferably 1 nm to 1,000 nm. From the viewpoint of durability, the average thickness of the first layer is preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 50 nm or more. Furthermore, the average thickness of the first layer is preferably 60 nm or more, more preferably 80 nm or more, and even more preferably 100 nm or more. From the viewpoint of rectification characteristics, the average thickness of the first layer is preferably 800 nm or less, more preferably 600 nm or less, and even more preferably 400 nm or less. Furthermore, the average thickness of the first layer is preferably 300 nm or less, more preferably 200 nm or less, and even more preferably 100 nm or less. The average thickness of the first layer is expressed by the arithmetic mean of the thicknesses at five points. If the sheet contains multiple first layers, it is preferable that the average thickness of each first layer is within the range described above.

[0082] [Second layer] The second layer contains a coordination polymer comprising a second central metal selected from the group consisting of Fe, Co, Ni, Cu, and Zn, which is different from the first central metal, and a polydentate ligand represented by formula (1) that coordinates to the second central metal.

[0083] From the viewpoint of rectification characteristics, the second central metal is preferably selected from the group consisting of Fe, Co, and Ni, and more preferably selected from the group consisting of Fe and Co. From the viewpoint of rectification characteristics, the second central metal is preferably Fe, Co, or Ni, and more preferably Fe or Co. In a preferred embodiment, the first central metal is Fe and the second central metal is Co. In another preferred embodiment, the first central metal is Co and the second central metal is Fe.

[0084] The oxidation number of the second central metal may be determined according to the type of the second central metal, the type of the first central metal, and the oxidation number of the first central metal. The oxidation number of the second central metal may be the same as that of the first central metal. The oxidation number of the second central metal may be different from that of the first central metal. Examples of oxidation numbers for the second central metal include monovalent, divalent, and trivalent. The oxidation number of Fe is preferably divalent. The oxidation number of Co is preferably divalent. The oxidation number of Ni is preferably divalent. The oxidation number of Cu is preferably divalent. The oxidation number of Zn is preferably divalent.

[0085] The configuration of the polydentate ligand represented by formula (1) included in the second layer is the same as the configuration of the polydentate ligand represented by formula (1) included in the first layer as described above. The preferred configuration of the polydentate ligand represented by formula (1) included in the second layer is the same as the preferred configuration of the polydentate ligand represented by formula (1) included in the first layer as described above.

[0086] The polydentate ligand represented by formula (1) coordinates to the second central metal in the coordination polymer. The polydentate ligand represented by formula (1) may coordinate to multiple second central metals. In other words, the coordination polymer may contain multiple second central metals. The coordination polymer may contain multiple polydentate ligands represented by formula (1).

[0087] From the viewpoint of rectification characteristics, the coordination polymer preferably has a constituent unit represented by the following formula (3). The constituent unit represented by formula (3) corresponds to the smallest constituent unit formed by the coordination of the polydentate ligand represented by formula (1) to the second central metal.

[0088] [ka]

[0089] In formula (3), M 2 represents the second central metal, R 1 This is R in equation (1) described above. 1 It is synonymous with R 2 This is R in equation (1) described above.2 This is equivalent to the above, and X is equivalent to X in equation (1) described above.

[0090] From the viewpoint of rectification characteristics, the coordination polymer is preferably having a repeating structure of constituent units represented by formula (3). In each constituent unit of the repeating structure described above, M 2 It is bonded to the nitrogen atom of the terpyridine structure contained in the adjacent structural unit, and the nitrogen atom of the terpyridine structure is bonded to the M contained in the adjacent structural unit. 2 It is connected.

[0091] The coordination polymer preferably has a network structure comprising a second central metal and a polydentate ligand represented by formula (1) that coordinates to the second central metal. Furthermore, the coordination polymer preferably has a hexagonal network structure. For example, the smallest unit of the hexagonal network structure is constructed by six second central metals and six polydentate ligands represented by formula (1) that connect the second central metals. For example, the smallest unit of the hexagonal network structure is constructed by connecting three constituent units represented by formula (3). Specific examples of the smallest unit of the hexagonal network structure are shown below. In the following specific examples, the nitrogen atom of the terpyridine structure (specifically M) 2 The nitrogen atom that is not coordinated to the second central metal may be further coordinated to another second central metal.

[0092] [ka]

[0093] The sheet may include one or more second layers.

[0094] The average thickness of the second layer is not limited. The average thickness of the second layer may be determined according to the application. From the viewpoint of rectification characteristics and durability, the average thickness of the second layer is preferably 1 nm to 1,000 nm. From the viewpoint of durability, the average thickness of the second layer is preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 50 nm or more. Furthermore, the average thickness of the second layer is preferably 60 nm or more, more preferably 80 nm or more, and even more preferably 100 nm or more. From the viewpoint of rectification characteristics, the average thickness of the second layer is preferably 800 nm or less, more preferably 600 nm or less, and even more preferably 400 nm or less. Furthermore, the average thickness of the second layer is preferably 300 nm or less, more preferably 200 nm or less, and even more preferably 100 nm or less. The average thickness of the second layer is expressed by the arithmetic mean of the thicknesses at five points. If the sheet contains multiple second layers, it is preferable that the average thickness of each second layer is within the range described above.

[0095] The average thickness of the second layer may be the same as the average thickness of the first layer. The average thickness of the second layer may be different from the average thickness of the first layer. From the viewpoint of the difference between the conductivity of the first layer and the conductivity of the second layer, the ratio of the average thickness of the second layer to the average thickness of the first layer is preferably 0.001 to 1,000, more preferably 0.1 to 10, and even more preferably 0.2 to 5.

[0096] From the viewpoint of rectification characteristics, it is preferable that the second layer is in contact with the first layer. Furthermore, it is preferable that the second layer is in close contact with the first layer. For example, it is preferable that the second layer is in contact with the first layer without any gap between the two layers. For example, it is preferable that the second layer is attached to the first layer. "Attachment" means that one object sticks to another object and does not separate. Sheets in the above configuration are easily formed by a manufacturing method including the steps (1) to (4) described later.

[0097] From the viewpoint of rectification characteristics and adhesion, it is preferable that the polydentate ligand represented by formula (1) coordinates to the first central metal and the second central metal at the interface between the first and second layers. At the interface between the first and second layers, one polydentate ligand coordinating to one first central metal may coordinate to multiple second central metals. For example, one polydentate ligand may coordinate to one first central metal and two second central metals. At the interface between the first and second layers, one polydentate ligand coordinating to one second central metal may coordinate to multiple first central metals. For example, one polydentate ligand may coordinate to two first central metals and one second central metal. Sheets in the above configuration are easily formed by a manufacturing method including steps (1) to (4) described later.

[0098] The metallic elements detected by energy-dispersive X-ray spectroscopy in at least one layer selected from the group consisting of the first and second layers may include at least two metallic elements selected from the group consisting of Fe, Co, Ni, Cu, and Zn. The metallic elements detected by energy-dispersive X-ray spectroscopy in at least one layer selected from the group consisting of the first and second layers may include the metallic elements constituting the first central metal and the metallic elements constituting the second central metal. The metallic elements detected by energy-dispersive X-ray spectroscopy in the first layer may include the metallic elements constituting the first central metal and the metallic elements constituting the second central metal. For example, if the first central metal in the first layer is Fe and the second central metal in the second layer is Co, then in addition to Fe, Co may be detected in the first layer. The metallic elements detected by energy-dispersive X-ray spectroscopy in the second layer may include the metallic elements constituting the first central metal and the metallic elements constituting the second central metal. For example, if the first central metal in the first layer is Fe and the second central metal in the second layer is Co, then in addition to Co, Fe may be detected in the second layer. Sheets in the manner described above are easily formed by a manufacturing method including steps (1) to (4) described below.

[0099] The sheet may further include other components, to the extent that it does not deviate from the spirit of this disclosure.

[0100] [Method of manufacturing the sheet] The method of manufacturing the sheet is not limited as long as a sheet with the desired properties can be obtained. The sheet may be manufactured by stacking a first layer and a second layer. Each layer may be manufactured independently. For example, the method for manufacturing an electrochromic sheet described in Japanese Patent Application Publication No. 2018-136556 may be applied to a method in which each layer is manufactured independently. Each layer may be manufactured stepwise in the same reaction vessel.

[0101] The method for manufacturing the sheet preferably includes the following steps (1) to (4). The method for manufacturing the sheet including the following steps (1) to (4) can form a sheet that exhibits excellent rectification characteristics. In the following description, the "multidentate ligand represented by formula (1)" may be simply referred to as the "multidentate ligand". (1) Bringing an organic phase containing a polydentate ligand represented by formula (1) into contact with an aqueous phase containing a first precursor that supplies a first central metal selected from the group consisting of Fe, Co, Ni, Cu, and Zn (hereinafter referred to as the "first step"), (2) Reacting a polydentate ligand with a first precursor at the interface between the organic phase and the aqueous phase to form a first layer containing a coordination polymer that includes a first central metal and a polydentate ligand that coordinates to the first central metal (hereinafter referred to as "second step"). (3) Replacing at least a portion of the aqueous phase with an aqueous phase containing a second precursor that supplies a second central metal, which is different from the first central metal and is selected from the group consisting of Fe, Co, Ni, Cu, and Zn (hereinafter referred to as "the third step"). (4) React the polydentate ligand with the second precursor at the interface between the organic phase and the aqueous phase containing the second precursor to form a second layer containing a coordination polymer that includes a second central metal and a polydentate ligand that coordinates to the second central metal (hereinafter referred to as "step 4").

[0102] (1st step) The first step involves bringing into contact an organic phase containing a polydentate ligand represented by formula (1) with an aqueous phase containing a first precursor that supplies a first central metal selected from the group consisting of Fe, Co, Ni, Cu, and Zn.

[0103] The method for producing the polydentate ligand represented by formula (1) is not limited. For example, the polydentate ligand represented by formula (1) may be produced by utilizing a reaction mechanism described in known literature (e.g., M. Cavazzini et al., Inorg. Chem. 2009, 48, 8578-8592). For example, the polydentate ligand represented by formula (1) may be produced by a method similar to the method for producing the terpyridine derivative represented by formula (i-1) described in Japanese Patent Application Publication No. 2018-136556.

[0104] The organic phase preferably further contains a solvent. Examples of solvents include organic solvents. The organic solvent may be selected from known organic solvents capable of dissolving the polydentate ligand represented by formula (1). From the viewpoint of maintaining phase separation between the organic phase and the aqueous phase, the organic phase preferably contains a low-polarity organic solvent. The term "low-polarity" as used with respect to organic solvents means polarity sufficient to allow phase separation from water. Examples of low-polarity organic solvents include ethyl acetate, ether (e.g., diethyl ether), petroleum ether, dichloromethane, benzene, toluene, dichloroethane, tetrachloromethane, cyclohexane, chloroform, carbon tetrachloride, and hexane. The organic phase may contain one or more solvents. The proportion of the low-polarity organic solvent in the solvent is preferably 50% or more by volume, more preferably 70% or more, even more preferably 90% or more, and particularly preferably 95% or more.

[0105] The first precursor is the source of the first central metal of the coordination polymer formed in the second step described below. Examples of the first precursor include metal salts or metal complexes. Examples of metal salts include salts of inorganic acids (e.g., hydrochloric acid, sulfuric acid, phosphoric acid, and boric acid), salts of organic acids (e.g., carboxylic acids and sulfonic acids), ammine complexes, cyano complexes, halogeno complexes, and hydroxyl complexes. The metal element contained in the first precursor is selected according to the type of first central metal of interest. Examples of first precursors containing Fe include iron(II) tetrafluoroborate and iron(II) chloride. Examples of first precursors containing Co include cobalt(II) tetrafluoroborate and cobalt(II) chloride.

[0106] As long as the phase separation between the organic phase and the aqueous phase is maintained, the method of bringing the organic phase and the aqueous phase into contact with each other is not limited. For example, the aqueous phase can come into contact with the organic phase by being supplied on top of it. From the viewpoint of maintaining the phase separation between the organic phase and the aqueous phase and the growth of coordination polymers at the interface between the organic phase and the aqueous phase, the first step preferably includes supplying the aqueous phase on top of the organic phase and bringing the aqueous phase into contact with the organic phase.

[0107] (2nd process) The second step involves reacting a polydentate ligand with a first precursor at the interface between the organic phase and the aqueous phase to form a first layer containing a coordination polymer that includes a first central metal and a polydentate ligand that coordinates to the first central metal.

[0108] The first layer, containing the coordination polymer, is formed by a reaction between a polydentate ligand and a first precursor at the interface between the organic phase and the aqueous phase. A specific example of the formation process of the first layer is described below. As contact between the organic phase and the aqueous phase continues, the reaction between the polydentate ligand and the first precursor proceeds at the interface between the organic phase and the aqueous phase, and the polydentate ligand coordinates to the first central metal. Since the polydentate ligand can coordinate to multiple first central metals, the reaction between the polydentate ligand and the first precursor (i.e., the coordination of the polydentate ligand to the first central metal) spreads in a chain reaction at the interface between the organic phase and the aqueous phase. Through the process described above, the first central metal and the polydentate ligand are linked alternately, forming the first layer containing the coordination polymer.

[0109] The reaction temperature may be determined considering the reaction rate. The reaction temperature may be determined within a range above the freezing point of the solvent and below the boiling point of the solvent. The reaction temperature may be 10°C to 50°C. The reaction temperature may be 10°C to 30°C. The reaction temperature may be 20°C to 30°C.

[0110] The reaction time may be determined considering the growth rate of the coordination polymer and the desired thickness of the first layer. The reaction time may range from 1 second to 1 month. For example, the thickness of the first layer can reach several hundred nanometers with a reaction time of about one day.

[0111] (3rd step) The third step involves replacing at least a portion of the aqueous phase with an aqueous phase containing a second precursor that supplies a second central metal, selected from the group consisting of Fe, Co, Ni, Cu, and Zn, which is different from the first central metal. According to the third step, the second precursor and free metal ions remaining after the second step are removed or reduced. As a result, the formation of the second layer is promoted in the fourth step described below.

[0112] The second precursor is a source of the second central metal of the coordination polymer formed in the fourth step described below. Examples of the second precursor include metal salts or metal complexes. Examples of metal salts include salts of inorganic acids (e.g., hydrochloric acid, sulfuric acid, phosphoric acid, and boric acid), salts of organic acids (e.g., carboxylic acids and sulfonic acids), ammine complexes, cyano complexes, halogeno complexes, and hydroxyl complexes. The metal element contained in the second precursor is selected according to the type of second central metal of interest. Examples of second precursors containing Fe include iron(II) tetrafluoroborate and iron(II) chloride. Examples of second precursors containing Co include cobalt(II) tetrafluoroborate and cobalt(II) chloride.

[0113] The third step may include replacing a portion of the aqueous phase with an aqueous phase containing the second precursor. If a portion of the aqueous phase is replaced with an aqueous phase containing the second precursor in the third step, the two aqueous phases can form a single aqueous phase containing the second precursor. The third step may also include replacing the entire aqueous phase with an aqueous phase containing the second precursor.

[0114] The method for replacing at least a portion of the aqueous phase with an aqueous phase containing the second precursor is not limited. The third step may include removing at least a portion of the aqueous phase and supplying an aqueous phase containing the second precursor. The third step may also include replacing at least a portion of the aqueous phase with water and supplying an aqueous phase containing the second precursor. Replacing at least a portion of the aqueous phase with water may be repeated. Replacing at least a portion of the aqueous phase with water can efficiently reduce the second precursor and free metal ions remaining after the second step.

[0115] (4th step) The fourth step involves reacting a polydentate ligand with the second precursor at the interface between the organic phase and the aqueous phase containing the second precursor to form a second layer containing a coordination polymer that includes a second central metal and a polydentate ligand that coordinates to the second central metal. If the entire aqueous phase in question was not replaced with the aqueous phase containing the second precursor in the third step, the term "aqueous phase" in the fourth step may refer to a mixture of the aqueous phase that remained unsubstituted in the third step and the aqueous phase introduced in the third step.

[0116] The second layer, containing the coordination polymer, is formed through a process similar to that of the first layer described above. In other words, the second layer, containing the coordination polymer, is formed through a reaction between a polydentate ligand and a second precursor that occurs at the interface between the organic phase and the aqueous phase.

[0117] The reaction temperature may be determined considering the reaction rate. The reaction temperature may be determined within a range above the freezing point of the solvent and below the boiling point of the solvent. The reaction temperature may be 10°C to 50°C. The reaction temperature may be 10°C to 30°C. The reaction temperature may be 20°C to 30°C.

[0118] The reaction time may be determined considering the growth rate of the coordination polymer and the desired thickness of the second layer. The reaction time may range from 1 second to 1 month. For example, the thickness of the second layer can reach several hundred nanometers with a reaction time of about one day.

[0119] The second layer, which contains the coordination polymer, tends to form beneath the first layer, which also contains the coordination polymer. This phenomenon is thought to be due to the second precursor, or metal ions derived from the second precursor, passing through the first layer and coming into contact with the organic phase.

[0120] Finally, the sheet is obtained by removing it from the reaction solution. One method for removing the sheet is the Langmuir-Schafer method (a method in which a substrate is brought parallel to the liquid-liquid interface where the sheet is formed and the sheet is transferred to the substrate). Another method for removing the sheet is to scoop it up with a hard substrate. Another method for removing the sheet is to remove the reaction solution and place the sheet on a substrate that has been placed in advance at the bottom of the reaction vessel.

[0121] [Application] The sheet relating to this disclosure can be applied to various technologies by utilizing its rectification characteristics. Examples of applications for the sheet include various electronic device materials. Specific applications of the sheet include diodes and light-emitting diodes. [Examples]

[0122] The present disclosure will be described in detail below with reference to examples. However, the present disclosure is not limited to the following examples. The matters shown in the following examples may be modified as appropriate without departing from the spirit of the present disclosure.

[0123] <Explanation of Abbreviations> The following abbreviations have the following meanings: "Co-tpy": A coordination polymer containing a central metal Co and a polydentate ligand (A) that coordinates to the central metal Co. "Fe-tpy": A coordination polymer containing a central metal Fe and a polydentate ligand (A) that coordinates to the central metal Fe. "Polydentate ligand (A)": 1,3,5-tris-(4-(2,2':6',2"-terpyridyl)phenyl)benzene, represented by the following formula.

[0124] [ka]

[0125] <Synthesis of polydentate ligand (A)> To a tetrahydrofuran solution (40 mL) containing 75.2 mg of 1,3,5-tribromobenzene, 400 mg of 4'-{4-(neopentylglycolatoborone)phenyl}-2,2':6',2”-terpyridine, and 27.2 mg of tetrakistriphenylphosphine palladium (0), an aqueous solution (8.3 mL) containing 174.6 mg of sodium carbonate was added, and the mixture was stirred at 85°C for 18 hours. After the reaction mixture was allowed to return to room temperature, it was filtered. The resulting solid was washed with tetrahydrofuran, pure water, and diethyl ether, and 200 mg of the target product was obtained by vacuum drying (yield 84%).

[0126] <Example 1> [Preparation of Fe / Co-tpy sheet] Dichloromethane 0.1 mg / 1 mL (1 × 10 -4 A dichloromethane solution of polydentate ligand (A) was prepared by dissolving it at a concentration of mol / L. A single-crystal silicon substrate or a fluorine-doped tin oxide (FTO) coated glass substrate was placed at the bottom of a 40 mm inner diameter glass vial (hereinafter, in this paragraph, "single-crystal silicon substrate or fluorine-doped tin oxide coated glass substrate" may simply be referred to as "substrate"). 10 mL of the dichloromethane solution of polydentate ligand (A) was slowly added to the glass vial, followed by 10 mL of pure water, to form an aqueous layer on top of the dichloromethane layer (organic phase). 5 × 10¹⁶ units were added to the aqueous layer. -2The reaction was initiated by adding 10 mL of mol / L iron(II) tetrafluoroborate aqueous solution. After allowing the glass vial to stand for 24 hours, a purple Fe-tpy thin film formed at the interface between the dichloromethane layer and the aqueous layer. By repeatedly removing a portion of the aqueous layer and adding an equal amount of pure water, the concentration of iron ions in the aqueous layer was increased to 1 × 10⁻⁶. -4 The concentration was reduced to mol / L or less. The aqueous layer was removed until its volume was 10 mL, and 5 × 10 -2 10 mL of a mol / L cobalt(II) chloride aqueous solution was added to the aqueous layer to initiate the formation of a Co-tpy thin film. After allowing the glass vial to stand for 5 days, a portion of the aqueous layer was removed and diluted with pure water, resulting in a cobalt ion concentration of 1 × 10⁻⁶ in the aqueous layer. -4 The process was repeated until the concentration was less than mol / L. Ethanol was added to the aqueous layer, and then the entire solution in the glass vial was slowly removed in the order of the dichloromethane layer and the aqueous layer, and the Fe / Co-tpy sheet formed at the interface between the dichloromethane layer and the aqueous layer was transferred to a substrate placed at the bottom of the glass vial. The resulting laminate consists of the substrate, the Co-tpy layer and the Fe-tpy layer in this order. The Fe / Co-tpy sheet transferred onto a single-crystal silicon substrate is used for elemental mapping analysis and thickness measurement as described later. The Fe / Co-tpy sheet transferred onto a fluorine-doped tin oxide glass substrate is used for current-voltage characteristic measurement as described later. The Fe / Co-tpy sheet consists of an Fe-tpy layer and a Co-tpy layer. The Fe-tpy layer corresponds to the first layer in this disclosure, and the Co-tpy layer corresponds to the second layer in this disclosure.

[0127] [Elemental Mapping Analysis] A protective film was formed by applying an oil-based marker to an Fe / Co-tpy sheet transferred onto a single-crystal silicon substrate. The cross-section of the sheet was exposed by processing using a focused ion beam processing apparatus. Elemental mapping analysis by energy-dispersive X-ray spectroscopy was performed, and the elemental distribution of Fe and Co in the cross-section was measured by dark-field scanning transmission electron microscopy. In the region corresponding to the Fe-tpy layer, a small amount of Co was detected in addition to Fe. The Co detected in the region corresponding to the Fe-tpy layer is thought to be a component derived from cobalt(II) chloride used as a raw material for the Co-tpy layer. In the region corresponding to the Co-tpy layer, only Co was detected.

[0128] [Measure the score] Based on the elemental mapping analysis and cross-sectional observations using scanning transmission electron microscopy (STEM) described above, the average thickness of each layer of the Fe / Co-type sheet was measured. The average thickness of the Fe-type layer was 110 nm. The average thickness of the Co-type layer was 30 nm.

[0129] <Example 2> [Preparation of Co / Fe-tpy sheet] Dichloromethane 0.1 mg / 1 mL (1 × 10 -4 A dichloromethane solution of polydentate ligand (A) was prepared by dissolving it at a concentration of mol / L. A single-crystal silicon substrate and / or a fluorine-doped tin oxide (FTO) coated glass substrate was placed at the bottom of a glass vial with an inner diameter of 40 mm (hereinafter, in this paragraph, "single-crystal silicon substrate or fluorine-doped tin oxide coated glass substrate" may simply be referred to as "substrate"). 10 mL of the dichloromethane solution of polydentate ligand (A) was slowly added to the glass vial, followed by 10 mL of pure water, to form an aqueous layer on top of the dichloromethane layer (organic phase). 5 × 10¹⁶ units were added to the aqueous layer. -2The reaction was initiated by adding 10 mL of mol / L cobalt(II) tetrafluoroborate aqueous solution. After allowing the glass vial to stand for 2 days, an orange-yellow Co-tpy thin film formed at the interface between the dichloromethane layer and the aqueous layer. By repeatedly removing a portion of the aqueous layer and adding an equal amount of pure water, the concentration of cobalt ions in the aqueous layer was increased to 1 × 10⁻⁶. -4 The concentration was reduced to mol / L or less. The aqueous layer was removed until its volume was 10 mL, and the pH was adjusted to 2 with hydrochloric acid. -2 10 mL of mol / L iron(II) chloride aqueous solution was added to the aqueous layer to initiate the formation of a Fe-tpy thin film. After allowing the glass vial to stand for 4 days, a portion of the aqueous layer was removed and diluted with pure water, resulting in an iron ion concentration of 1 × 10⁻⁶ in the aqueous layer. -4 The process was repeated until the concentration was less than mol / L. Ethanol was added to the aqueous layer, and then the entire solution in the glass vial was slowly removed in the order of the dichloromethane layer and the aqueous layer. The Co / Fe-tpy sheet formed at the interface between the dichloromethane layer and the aqueous layer was transferred to a glass substrate placed at the bottom of the glass vial. The resulting laminate consists of a glass substrate, an Fe-tpy layer, and a Co-tpy layer in this order. The Co / Fe-tpy sheet transferred onto a single-crystal silicon substrate is used for elemental mapping analysis and thickness measurement as described later. The Co / Fe-tpy sheet transferred onto a fluorine-doped tin oxide glass substrate is used for current-voltage characteristic measurement as described later. The Co / Fe-tpy sheet consists of a Co-tpy layer and an Fe-tpy layer. The Co-tpy layer corresponds to the first layer in this disclosure, and the Fe-tpy layer corresponds to the second layer in this disclosure.

[0130] [Elemental Mapping Analysis] The elemental distribution of Fe and Co in the Co / Fe-tpy sheet was measured using a method similar to that described in Example 1 above. In the region corresponding to the Co-tpy layer, a small amount of Fe was detected in addition to Co. The Fe detected in the region corresponding to the Co-tpy layer is thought to be a component derived from iron(II) chloride used as the raw material for the Fe-tpy layer. In the region corresponding to the Fe-tpy layer, only Fe was detected.

[0131] [Measure the score] The average thickness of each layer of the Co / Fe-type sheet was measured by a method similar to that described in Example 1 above. The average thickness of the Co-type layer was 130 nm. The average thickness of the Fe-type layer was 45 nm.

[0132] <Example 3> [Creating a Fe-tpy sheet] Dichloromethane 0.1 mg / 1 mL (1 × 10 -4 A polydentate ligand (A) was dissolved at a concentration of mol / L to prepare a dichloromethane solution of polydentate ligand (A). 10 mL of the dichloromethane solution of polydentate ligand (A) was slowly added to a 40 mm inner diameter glass vial, followed by 10 mL of pure water, forming an aqueous layer on top of the dichloromethane layer (organic phase). 5 × 10¹⁶ units were added to the aqueous layer. -2 10 mL of mol / L iron(II) tetrafluoroborate aqueous solution was added. After the glass vial was left to stand for 1 day, a purple Fe-tpy thin film formed at the interface between the organic layer and the aqueous layer. The aqueous layer was washed with pure water, and then the aqueous layer and the dichloromethane layer were removed. The thin film was washed with dichloromethane and then filtered. The thin film was washed with pure water, ethanol, and dichloromethane, and then vacuum dried. Fe-tpy sheets were prepared using the above procedure. The thickness of the Fe-tpy sheets, measured using an atomic microscope, was 200 nm on average.

[0133] [Creating a Co-tpy sheet] Chloroform 0.1 mg / 1 mL (1 × 10 -4 A chloroform solution of polydentate ligand (A) was prepared by dissolving it at a concentration of mol / L. 10 mL of the chloroform solution of polydentate ligand (A) was slowly added to a 40 mm inner diameter glass vial, followed by 10 mL of pure water, forming an aqueous layer on top of the chloroform layer (organic phase). 10 × 10¹⁶ units were added to the aqueous layer. -2Ten milliliters of mol / L cobalt(II) chloride aqueous solution were added. The glass vial was left to stand for eight days, after which an orange-yellow Co-tpy thin film formed at the interface between the organic layer and the aqueous layer. After washing the aqueous layer with pure water, the aqueous layer and then the chloroform layer were removed. The thin film was washed with chloroform and then filtered. The thin film was washed with pure water, ethanol, and chloroform, and then vacuum-dried. A Co-tpy sheet was obtained by the above procedure. The thickness of the Co-tpy sheet, measured using an atomic microscope, was 120 nm on average.

[0134] [Creating Co-tpy / Fe-tpy sheets] A Co-tpy / Fe-tpy sheet was obtained by layering an Fe-tpy sheet and then a Co-tpy sheet on an indium tin oxide (ITO) coated glass substrate. The resulting laminate includes an indium tin oxide coated glass substrate, an Fe-tpy layer, and a Co-tpy layer in that order. The Co-tpy / Fe-tpy sheet includes a Co-tpy layer and an Fe-tpy layer. The Co-tpy layer corresponds to the first layer in this disclosure, and the Fe-tpy layer corresponds to the second layer in this disclosure.

[0135] <Comparative Example 1> [Creating a Fe-tpy sheet] A Fe-tpy sheet prepared according to the method described in Example 3 above was placed on an indium tin oxide (ITO) coated substrate. The resulting laminate consists of the indium tin oxide coated substrate and the Fe-tpy layer in that order.

[0136] <Comparative Example 2> [Creating a Co-tpy sheet] A Co-tpy sheet prepared according to the method described in Example 3 above was placed on an indium tin oxide (ITO) coated substrate. The resulting laminate includes the indium tin oxide coated substrate and the Co-tpy layer in that order.

[0137] <Evaluation: Current-Voltage Characteristics> The current-voltage characteristics of each laminate in Examples 1-3 and Comparative Examples 1-2 were measured using the following method. Electrodes were prepared by coating a gallium indium alloy onto a glassy carbon electrode. The obtained gallium indium electrode was brought into contact with the surface of a sheet placed on a substrate. The current flowing in the thickness direction of the sheet was measured by applying a voltage. The measurement results are shown in Figures 1-5. Figure 1 is a diagram of the current-voltage characteristics in Example 1. Figure 2 is a diagram of the current-voltage characteristics in Example 2. Figure 3 is a diagram of the current-voltage characteristics in Example 3. Figure 4 is a diagram of the current-voltage characteristics in Comparative Example 1. Figure 5 is a diagram of the current-voltage characteristics in Comparative Example 2. According to Figures 1-5, it was confirmed that the sheets in Comparative Examples 1-2 did not exhibit rectification characteristics, while the sheets in Examples 1-3 did. Compared to the sheet in Example 3, more current flowed in the sheets in Examples 1-2. Note that the difference in substrate type between the examples and comparative examples did not affect the current-voltage characteristics of the sheets.

Claims

1. A first layer comprising a coordination polymer containing a first central metal selected from the group consisting of Fe and Co, and a polydentate ligand that coordinates to the first central metal, A second layer comprising a coordination polymer containing a second central metal selected from the group consisting of Fe and Co, which is different from the first central metal, and a polydentate ligand that coordinates to the second central metal, Includes, The polydentate ligand is 1,3,5-tris-(4-(2,2':6',2''-terpyridyl)phenyl)benzene, At the interface between the first layer and the second layer, the multidentate ligand is coordinated to the first central metal and the second central metal. Seat.

2. The sheet according to claim 1, wherein the second layer is in contact with the first layer.

3. The sheet according to claim 1 or claim 2, wherein the metallic elements detected by energy-dispersive X-ray spectroscopy in at least one layer selected from the group consisting of the first layer and the second layer include Fe and Co.

4. The sheet according to any one of claims 1 to 3, wherein the metal elements detected in the first layer by energy-dispersive X-ray spectroscopy include the metal elements constituting the first central metal and the metal elements constituting the second central metal.

5. The sheet according to any one of claims 1 to 4, wherein the metal elements detected in the second layer by energy-dispersive X-ray spectroscopy include the metal elements constituting the first central metal and the metal elements constituting the second central metal.

6. The sheet according to any one of claims 1 to 5, wherein the first central metal is Fe and the second central metal is Co.

7. The sheet according to any one of claims 1 to 6, wherein the first central metal is Co and the second central metal is Fe.

8. The sheet according to any one of claims 1 to 7, wherein the average thickness of the first layer is 1 nm to 1,000 nm, and the average thickness of the second layer is 1 nm to 1,000 nm.

9. Bringing an organic phase containing a polydentate ligand and an aqueous phase containing a first precursor that supplies a first central metal selected from the group consisting of Fe and Co into contact with each other, The polydentate ligand and the first precursor are reacted at the interface between the organic phase and the aqueous phase to form a first layer containing a coordination polymer comprising the first central metal and the polydentate ligand that coordinates to the first central metal. Replacing at least a portion of the aqueous phase with an aqueous phase containing a second precursor that supplies a second central metal, which is different from the first central metal and selected from the group consisting of Fe and Co, The polydentate ligand and the second precursor are reacted at the interface between the organic phase and the aqueous phase containing the second precursor to form a second layer containing a coordination polymer comprising the second central metal and the polydentate ligand that coordinates to the second central metal. Includes, The polydentate ligand is 1,3,5-tris-(4-(2,2':6',2''-terpyridyl)phenyl)benzene, At the interface between the first layer and the second layer, the multidentate ligand is coordinated to the first central metal and the second central metal. A method for manufacturing a sheet.

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