Ionic metal complex, anion detecting agent, and anion detecting method

Abstract

To provide a method for simply and accurately detecting or determining anions.SOLUTION: An ionic metal complex comprising a metal complex cation and at least one selected from the group consisting of predetermined anions.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an ionic metal complex, an anion detecting agent, and an anion detecting method. [Background technology]

[0002] In order to detect anions in aqueous samples, instrumental analyses such as ion chromatography and mass spectrometry are generally carried out.

[0003] For example, Patent Document 1 discloses a method for detecting specific anions (e.g., perchlorate ions (ClO4)) in an aqueous sample using a detection agent containing an aromatic compound represented by 3,5-bis(imidazol-1-yl-methyl)-2,4,6-trimethylphenol (bitph). - ), tetrafluoroborate ion (BF4 - ), and nitrate ions (NO3 - The detection agent forms a encapsulated molecule to capture the target anion, thereby enabling the detection of the anion.

[0004] Currently, preventing global warming is an urgent issue, and reducing carbon dioxide (CO2) emissions is a top priority. Most of the CO2 in the atmosphere dissolves in seawater, and 90% of it is converted into bicarbonate ions (HCO3 - ) in the waters of the world's oceans and rivers in order to trace the CO2 cycle. - However, quantifying bicarbonate ions is difficult.

[0005] A known method for quantifying bicarbonate ions and carbonate ions using conventional technology involves acidifying an aqueous solution containing dissolved bicarbonate ions with an acid such as phosphoric acid, purging the solution with an inert gas such as nitrogen, releasing the CO2 in the resulting aqueous solution into the gas phase, and quantifying the CO2 in the gas phase using an instrumental analysis method such as infrared spectroscopy.

[0006] This method requires complicated quantitative operations, takes several hours to complete, and requires expensive equipment. Another method is to perform neutralization titration and calculate the sum of bicarbonate ions and carbonate ions. This method also requires complicated operations, and there are concerns that the presence of ammonia or amine compounds may reduce the accuracy of the measurement, making it difficult to obtain accurate HCO3 - Quantitation of is not possible.

[0007] Patent Document 2 discloses a simple method for detecting perchlorate ions and other anions using a compound consisting of a cationic metal complex having a capsule structure and a dye anion.

[0008] However, the method disclosed in the document does not allow for the detection of bicarbonate ions. There is a need for a method for easily detecting and accurately quantifying anions such as bicarbonate ions and carbonate ions, which are generated when carbon dioxide, which is believed to be a cause of global warming, dissolves in ocean or land water.

[0009] The detection and quantification of anions in aqueous solutions is a useful technique used to track the nitrogen cycle in environmental waters, measure the concentration of harmful substances and chlorine in drinking water, etc. Known methods for detecting anions in aqueous solutions include instrumental analysis using ion chromatography or mass spectrometry, methods for detecting and quantifying anions using analytical procedures based on chemical treatment, and a simple detection method called a pack test.

[0010] While detection and quantification by ion chromatography can simultaneously detect and quantify multiple ions, it is not suitable for rapid detection and quantification of anions because the equipment is expensive, the maintenance and operation of the equipment are cumbersome, and the measurement takes several hours, including the time required to set up the equipment.In addition, detection or quantification of anions such as bicarbonate ion and carbonate ion is essentially impossible because it is difficult to avoid the influence of carbon dioxide dissolved in the air.

[0011] For example, one known method for chemical analysis is the Mohr method, which involves adding a 0.5% potassium chromate solution to a solution, then dripping a silver nitrate solution of known concentration into the solution, and determining the amount of chloride ions in the solution from the amount of silver nitrate added when a reddish-brown precipitate of silver chromate begins to form.

[0012] The Pack Test is a highly versatile method. For example, nitrate ions can be reduced to nitrous acid with metallic zinc, then converted to an azo compound, and the nitrate ions can be quantified based on the intensity of the resulting color. While it can be easily used outdoors, it has the disadvantage of not being able to obtain numerical results.

[0013] The detection of anions using chemical treatments or pack tests is generally performed by exploiting the specific chemical reactivity of the target anions, so the detection of chemically inert (i.e., chemically unreactive) anions must primarily rely on instrumental analysis.

[0014] Bicarbonate ions, or carbonate ions generated through equilibrium with bicarbonate ions, are a type of anion with poor chemical reactivity. For example, converting them into colored substances is difficult, and therefore no detection methods using pack tests or similar have been developed. Bicarbonate ions and carbonate ions in aqueous solutions are generated by dissolving carbon dioxide in the gas phase. For example, techniques for detecting and quantifying bicarbonate ions and carbonate ions are extremely useful in quantifying bicarbonate ions in seawater or blood, which are important in studying the process or mechanism of global warming.

[0015] Currently, the most well-known method for quantifying bicarbonate ions (and carbonate ions) in aqueous solutions is to acidify the solution, release the resulting carbon dioxide into the gas phase, and then quantify the concentration of this carbon dioxide using infrared spectroscopy. Another known method involves adding acid to the solution and calculating the concentration of bicarbonate ions (and carbonate ions) from the amount of acid required to neutralize all of the bicarbonate ions (and carbonate ions). However, both methods require complex procedures; the former requires expensive equipment, and the latter makes accurate quantification difficult when bases such as amines are present in the sample, as they act as interfering ions. Furthermore, the concentration of bicarbonate ions in aqueous solutions changes as carbon dioxide present in the air dissolves. Therefore, unless the sample is handled in a way that prevents contact with the gas phase, a shorter analytical procedure is required.

[0016] Simple quantitative techniques for chemically inert anions have not been fully developed, and in particular, simple methods for detecting and quantifying bicarbonate ions have not been developed. Recently, a technique has been developed for detecting and quantifying chemically inert perchlorate ions, in which a compound consisting of a metal complex cation and a dye anion undergoes counterion exchange with the perchlorate ion and the dye anion, releasing a dye anion corresponding to the amount of perchlorate ion into an aqueous solution, thereby coloring the aqueous solution. However, this method has problems such as being unable to detect bicarbonate ions or carbonate ions, and being limited in the types of solvents that can be used for anion detection.

[0017] Bicarbonate and carbonate ions are known to be anions that are difficult to chemically convert into colored substances. To detect and quantify these anions, two methods are known: converting the bicarbonate or carbonate ions to carbon dioxide, expelling them into the gas phase, and quantifying the resulting carbon dioxide using infrared spectroscopy; or calculating the amount of carbon dioxide by neutralization titration based on the amount of acid required to neutralize the anions to carbon dioxide. The former method requires a great deal of time and effort, and expensive equipment is required for carbon dioxide quantification. The latter method, while the neutralization titration itself is a simple procedure, requires meticulous work and has the drawback of being unable to eliminate the influence of bases such as amines when they are present.

[0018] A simple method for converting chemically inert inorganic ions such as bicarbonate ions into colored substances and quantifying them has not yet been developed. There is a need for a method for quickly and easily detecting or quantifying various anions, including chemically inert anions such as bicarbonate ions and carbonate ions, with high accuracy, even in places where the experimental and measurement environment is inadequate, such as marine areas or mountainous regions. [Prior art documents] [Patent documents]

[0019] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-168507 [Patent Document 2] International Publication No. 2021 / 039929 Summary of the Invention [Problem to be solved by the invention]

[0020] In view of the above circumstances, an object of the present invention is to provide a method for detecting or quantifying anions simply and with high accuracy. [Means for solving the problem]

[0021] The present inventors have conducted extensive research to solve the above-mentioned problems and have found that anions can be detected or quantified simply and with high accuracy by using an ionic gold complex based on a combination of a predetermined metal complex cation and a predetermined anion. Based on this finding, the present inventors have conducted further research and have completed the present invention.

[0022] That is, the present invention provides the following ionic metal complex, anion detecting agent, and anion detecting method. Section 1. An ionic metal complex comprising a metal complex cation and at least one anion selected from the group consisting of anions represented by the following formulas (1) to (7): [ka] TIFF0007825304000002.tif186170 [In formula (1), X1~X 12 each independently represents a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group; R1 is OH or O ― is. In formula (2), X 13 ~X 24 each independently represents a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group; R2 and R3 each independently represent OH or O; ― and at least one is O ― is. In formula (3), X 25 ~X 28 are each independently a hydrogen atom, SO3 ― , or SO3H, and X 25 ~X 28 At least one of the following is SO3 ― is. In formula (4), X 29 ~X 38are each independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group. In formula (5), R4 and R5 each independently represent SO3 ― or SO3H, and at least one is SO3 ― is. In formula (6), X 39 ~X 48 are each independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group; R6 is OH or O ― is. In formula (7), X 49 ~X 58 are each independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group; R7 and R8 are each independently OH or O ― and at least one is O ― It is. Section 2. Item 2. The ionic metal complex according to item 1, wherein the metal complex cation is represented by the following formula (8) or (9): [ka] [In formulas (8) and (9), A1 to A 42 each independently represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an aryl group, an n-butyl group, a tert-butyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, a carboxy group, a sulfonic acid group, or a methoxy group. M1 and M2 each independently represent a trivalent metal ion. Section 3. M1 and M2 are each independently Mn 3+ , Al 3+ , Co 3+ or Fe 3+ Item 2. The ionic metal complex according to Item 1, Section 4. 4. An anion detecting agent comprising the ionic metal complex according to claim 1. Section 5. Item 5. The detection agent according to item 4, for detecting bicarbonate ions, carbonate ions, perchlorate ions, tetrafluoroborate ions, nitrate ions, nitrite ions, halide ions, phosphate ions, phosphite ions, perfluorooctanesulfonate ions, or perfluorooctanoate ions. Section 6. A step of obtaining a mixture of an aqueous sample and the ionic metal complex according to any one of items 1 to 3 or the anion detector according to item 4 or 5; A method for detecting anions in an aqueous sample, comprising the steps of detecting anions contained in the aqueous sample by any one of the following methods (i) to (iv) in this order: (i) Visually confirm the color of the mixture. (ii) Measuring the visible and ultraviolet absorption spectrum of the mixture (iii) measuring the fluorescence spectrum of the mixture (iv) chemical reactions of the anions in said mixture; Section 7. A step of obtaining a mixture of an aqueous sample and the ionic metal complex according to any one of claims 1 to 3 or the anion detector according to claim 4 or 5; A method for quantifying anions in an aqueous sample, comprising the steps of quantifying anions contained in the aqueous sample by any one of the following methods (i) to (iii) in this order: (i) Measuring the visible and ultraviolet absorption spectrum of the mixture (ii) measuring the fluorescence spectrum of the mixture; (iii) a chemical reaction of the anions in said mixture; [Effects of the Invention]

[0023] According to the ionic metal complex, anion detecting agent, and anion detecting method of the present invention, anions can be detected or quantified simply and with high accuracy. [Brief explanation of the drawings]

[0024] [Figure 1] Schematic diagram of the single-crystal structure of [SO⊂Cu2(m-bbitrb)4](BTB)2. [Figure 2] Schematic diagram of the single crystal structure of [SO⊂Cu2(m-bbitrb)4](BPB). [Figure 3] Schematic diagram of the single crystal structure of [SO⊂Cu₂(m-bbitrb)₄](BCG). [Figure 4] Schematic diagram of the crystal structure of [SO4⊂Cu2(m-bdbitrbNH2)4](SO4). [Figure 5] Schematic diagram of the crystal structure of [SO4⊂Cu2(m-bdmbitrbNH2)4](IC). [Figure 6] Schematic diagram of the crystal structure of [SO4 ⊂ Cu2(m-bbitrbNH2)4](dmasbs)2. [Figure 7] Schematic diagram of the crystal structure of [SO4 ⊂ Cu2(m-bbitrbBr)4](Hfs)2. [Figure 8] Schematic diagram of the crystal structure of [SO4 ⊂ Cu2(m-bbitrbNH2)4](bssbp). [Figure 9] Schematic diagram of the crystal structure of [Mn(salophen)(MO)]. [Figure 10] Schematic diagram of the crystal structure of [Mn(salophen)(BTB)]. [Figure 11] Schematic diagram of the crystal structure of [Mn(tpp)(MO)]. [Figure 12] Photograph showing anion detection by [SO⊂Cu(m-bbitrb)⊂](BTB)⊂. [Figure 13] The visible-ultraviolet absorption spectrum (top) of an aqueous solution of sodium bicarbonate colored by [SO⊂Cu₂(m-bbitrb)₄](BPB)₂, and a chart plotting its absorption maximum (586 nm) (bottom). [Figure 14] Photograph (top) showing anion detection by [SO⊂Cu₂(m-bbitrbNO₂)₄](BCG) and a plot (bottom) of the absorbance at the absorption maximum determined using its visible-ultraviolet spectrum. [Figure 15]A photograph (top) showing anion detection using [Mn(salophen)(MO)] and a chart (bottom) plotting the absorbance at the maximum absorption of each aqueous solution. [Figure 16] A photograph of an aqueous solution containing anions colored by [Mn(salophen)(BTB)] (top) and a chart plotting the absorbance at the maximum absorption of each aqueous solution (bottom). [Figure 17] A photograph of an aqueous solution containing anions colored by [Mn(tpp)(MO)] (top) and a chart plotting the absorbance at the maximum absorption of each aqueous solution (bottom). [Figure 18] Photograph showing the detection of anions by [SO⊂Cu₂(m-bbitrb)₄](BTB)₂. [Figure 19] The visible-ultraviolet absorption spectrum (left) of an aqueous solution of sodium bicarbonate colored by [SO⊂Cu₂(m-bbitrb)₄](BTB)₂, and a chart plotting its absorption maximum (616 nm) (right). [Figure 20] Photograph showing anion detection by [Mn(salophen)(BTB)]. [Figure 21] Visible-ultraviolet spectrum chart of an aqueous solution colored by [Mn(salophen)(BTB)] (left), and charts plotting the maximum absorption values ​​against each concentration (center) and (right). [Figure 22] The luminescence behavior of an aqueous solution containing perchlorate ions upon addition of solid powder of [SO4⊂Cu2(m-bbitrbNH2)4](dmasbs)2 (left), and a chart plotting the luminescence intensity at 512 nm determined by fluorescence spectroscopy against each concentration (right). [Figure 23] The luminescence of an aqueous solution containing perchlorate ions upon addition of a DMF solution of [SO⊂Cu₂(m-bbitrbNH₂)₄](dmasbs)₂ (left) and a chart plotting the luminescence intensity at 512 nm determined by fluorescence spectroscopy against each concentration (right). [Figure 24]Chart (right) plots the emission intensity at 512 nm of aqueous solutions containing perchlorate ions at concentrations below 0.001 mM upon addition of a DMF solution of [SO4⊂Cu2(m-bbitrbNH2)4](dmasbs)2. [Figure 25] The luminescence of ion-exchanged water (blank) treated with [SO⊂Cu⊂(m-bbitrbBr)⊂](Hfs)⊂ and sodium perchlorate aqueous solution (a), the fluorescence spectra of each aqueous solution (b), and a chart plotting the fluorescence intensity at 513 nm against the concentration of sodium perchlorate aqueous solution (c). DETAILED DESCRIPTION OF THE INVENTION

[0025] (1. Ionic Metal Complexes) The ionic metal complex of the present invention comprises a metal complex cation and an anion having a predetermined structure. When the ionic metal complex of the present invention is placed in the same system as an anion and comes into contact with the anion, a color reaction occurs. By confirming or measuring the presence or absence of the color reaction and the degree of the color reaction, the anion can be easily detected or quantified.

[0026] By adding an anion to be detected or quantified to the metal complex cation and the anion having a predetermined structure contained in the ionic metal complex of the present invention, the metal complex cation and the anion to be detected or quantified are bound to each other and precipitated as a precipitate. On the other hand, the anion having the predetermined structure is also called a "dye anion" or "fluorescent anion," and it is believed that the color reaction occurs when these anions are liberated.

[0027] The reaction proceeds more efficiently as the precipitate formed by the metal complex cation and the anion to be detected or quantified is preferentially deposited. The present invention is based on the discovery that the reaction can be made to proceed extremely efficiently by combining the metal complex cation with an anion having a specific structure, which will be described later.

[0028] (1.1. Anion) Such anions are represented by the following formulas (1) to (7). [ka] TIFF0007825304000005.tif186170 [In formula (1), X1~X 12 each independently represents a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group; R1 is OH or O ― is. In formula (2), X 13 ~X 24 each independently represents a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group; R2 and R3 each independently represent OH or O; ― and at least one is O ― is. In formula (3), X 25 ~X 28 are each independently a hydrogen atom, SO3 ― , or SO3H, and X 25 ~X 28 At least one of the following is SO3 ― is. In formula (4), X 29 ~X 38 are each independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group. In formula (5), R4 and R5 each independently represent SO3 ― or SO3H, and at least one is SO3 ― is. In formula (6), X 39 ~X 48are each independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group; R6 is OH or O ― is. In formula (7), X 49 ~X 58 are each independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group; R7 and R8 are each independently OH or O ― and at least one is O ― It is.

[0029] Such anions may be used singly or in combination. The anions represented by formulas (1) to (3) are so-called "dye anions" and become free ions to produce color. The anions represented by formulas (4) to (7) are so-called "fluorescent anions" and become fluorescent colors when free.

[0030] The ionic metal complex of the present invention is based on an equilibrium reaction as shown in Reaction Scheme 1 below.

[0031] [ka]

[0032] The anions represented by formulas (1) to (7) are also called "dye anions" or "fluorescent anions," as described above. The salt formed on the right side of the above equilibrium equation precipitates from the aqueous solution more quickly than the salt of the detecting agent on the left side, resulting in a significant color change (fluorescence reaction).

[0033] In this color reaction, the coexisting organic solvent can affect the packing of the salts produced on the right side of the equilibrium reaction, and therefore their solubility. As a result, the type of anion detected and the intensity required for quantification change depending on the type of organic solvent used.

[0034] The detection of anions in aqueous solutions using the ionic metal complexes of the present invention is significantly affected not only by the metal complex cations but also by the types of dye anions and fluorescent anions, because the structure of the anions significantly affects the solubility of the salts and colorants produced in the detection reaction in water, as described above.

[0035] (1.2. Metal Complex Cations) The metal complex cation is not particularly limited and a wide variety of known metal complex cations can be used, although it is preferable to use a metal complex cation represented by the following formula (8) or (9):

[0036] [ka] [In formulas (8) and (9), A1 to A 42 each independently represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an aryl group, an n-butyl group, a tert-butyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, a carboxy group, a sulfonic acid group, or a methoxy group. M1 and M2 each independently represent a trivalent metal ion.

[0037] Furthermore, M1 and M2 in the above formulas (8) and (9) each independently represent Mn 3+ , Al 3+ , Co 3+ or Fe 3+ Preferably, Mn 3+ It is particularly preferred that:

[0038] The ratio of the metal complex cations contained in the ionic metal complex to the anions represented by formulas (1) to (7) is preferably 0.1 to 10 (the moles of the anions divided by the moles of the metal complex cations), more preferably 0.5 to 3, and even more preferably 1 to 2.

[0039] (2. Anion Detector) The present invention includes an invention relating to an anion detecting agent. The anion detecting agent of the present invention is a detecting agent containing the above-mentioned ionic metal complex.

[0040] The anion detector of the present invention preferably contains a solvent in addition to the metal complex cation and the anion represented by formulas (1) to (7). The solvent is not particularly limited as long as it is an organic solvent, and examples thereof include N,N-dimethylformamide (DMF), methanol, ethanol, acetone, acetonitrile, tetrahydrofuran (THF), acetone, and isopropyl alcohol. These may be used alone or in combination. The amount of solvent in the anion detector may be appropriately determined depending on the purpose of the detector.

[0041] The anion detector of the present invention may contain other additives as long as they do not impair the effects and objects of the present invention. Examples of such additives include silver ions, barium ions, calcium ions, magnesium ions, ammonium ions, and tetraphenylphosphonium ions. These may be contained alone or in combination.

[0042] By using the anion detector of the present invention, various anions can be suitably detected and quantified. Examples of such anions include, but are not limited to, bicarbonate ion, carbonate ion, perchlorate ion, tetrafluoroborate ion, nitrate ion, nitrite ion, halide ion, phosphate ion, phosphite ion, perfluorooctanesulfonate ion, and perfluorooctanoate ion. Among these, even chemically inactive anions that are difficult to detect using conventional techniques, such as bicarbonate ion or carbonate ion, can be detected or quantified simply and with high accuracy.

[0043] (3. Anion Detection and Quantitation Methods) The present invention includes an anion detection method and an anion quantification method, which involve mixing an aqueous sample to be tested with the ionic metal complex or the anion detector of the present invention.

[0044] When detecting anions in an aqueous sample, the presence or absence of anions can be confirmed by any of the following methods (i) to (iv). (i) Visually confirm the color of the mixture. (ii) Measuring the visible and ultraviolet absorption spectrum of the mixture (iii) measuring the fluorescence spectrum of the mixture (iv) chemical reactions of the anions in said mixture;

[0045] Visual confirmation involves adding the ionic metal complex or anion detecting agent of the present invention to an aqueous sample, and visually confirming that the dye anion contained in the ionic metal complex is liberated and interferes with the sample.

[0046] For more objective and accurate detection without relying on visual observation, it is also preferable to perform visible-ultraviolet absorption spectroscopy. Furthermore, when a fluorescent anion is used as the anion liberated when the mixture is obtained, it is also preferable to perform fluorescence spectroscopy. Alternatively, it is also preferable to subject the obtained mixture to an appropriate chemical reaction to detect the anion.

[0047] The chemical reaction here refers to a reaction that converts a substance into a specific organic compound by changing the acidity (pH) of the aqueous solution or by adding a detection reagent.

[0048] For example, one example of a sodium salt of an anionic compound represented by formula (1) is the pH indicator known as bromothymol blue (CAS number 34722-90-2, NaBTB). This anionic dye is green under neutral conditions, yellow under acidic conditions, and deep blue under basic (alkaline) conditions. In coloration experiments using this anionic dye, adding a few drops of sodium hydroxide solution to an aqueous sample turns the solution blue, allowing for the detection and quantification of the anion.

[0049] In addition, the azo dye used as the main component of the dye known as methyl orange is orange under neutral and basic (alkaline) conditions, and red under acidic conditions. In coloration using this anionic dye, adding a few drops of dilute hydrochloric acid to the aqueous sample obtained in the coloration experiment turns the aqueous solution red, which can be used to detect and quantify the anion.

[0050] Among the above-mentioned methods, when a visible-ultraviolet absorption spectrum measurement, a fluorescence spectrum measurement, or a chemical reaction is carried out, not only anion detection but also quantification can be carried out.

[0051] Although the embodiments of the present invention have been described above, the present invention is not limited to these examples, and it goes without saying that the present invention can be embodied in various forms without departing from the spirit of the present invention. [Example]

[0052] Hereinafter, the embodiments of the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[0053] Example 1 The anion represented by formula (1) is the sodium salt of the anionic compound (NaBTB), bromothymol blue (CAS number 34722-90-2) to BTB. -In addition, the metal complex cation [SO⊂Cu(m-bbitrb)⊂]SO⊂·8H⊂O (m-bbitrb = 1,3-bis(benzimidazol-1-yl-methyl)-2,4,6-trimethylbenzene) (starting complex 1) was synthesized according to the method described in the literature (Dalton Trans., 2014, Volume 43, pp. 17924-17927).

[0054] <Synthesis of [SO⊂Cu(m-bbitrb)⊂](BTB)⊂ Starting complex 1 (0.0933 g, 0.050 mmol) was dissolved in 90 mL of DMF. A solution of NaBTB (0.0624 g, 0.096 mmol) in 90 mL of water was added to this solution, mixed, and then allowed to stand for several days. The resulting reddish-brown powder was collected by suction filtration. The structure of this product was confirmed by single-crystal X-ray analysis.

[0055] -Single crystal X-ray structure analysis results- triclinic, space group P-1 (no. 2), a = 13.0859(2) Å, b = 17.7664(3) Å, c = 18.6487(3) Å, α = 66.175(2) °, β= 78.872(1) °,γ = 69.607(1)°, V = 3710.67(12) Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 14807 / 13891 / 1004, R1= 0.0670, wR2= 0.1917.

[0056] The single crystal structure of [SO⊂Cu(m-bbitrb)⊂](BTB)⊂ is shown in Figure 1.

[0057] Example 2 The anion represented by formula (1) is the sodium salt of the anionic compound (NaHBPB), bromophenol blue (CAS number 34725-61-6) to BTB. 2- was prepared.

[0058] <Synthesis of [SO⊂Cu2(m-bbitrb)4](BPB)> The starting material complex 1 (0.0937 g, 0.045 mmol) was dissolved in 10 mL of DMF. To this was added an aqueous solution of NaHBPB (0.0688 g, 0.10 mmol) dissolved in 10 mL of water, and the mixture was allowed to stand for several days. The resulting powder was collected by suction filtration. The structure of the product was confirmed by single crystal X-ray analysis. The results of single crystal X-ray analysis indicated that the obtained ionic metal complex was BTB. 2- It was revealed that the compound has a counter ion of

[0059] -Single crystal X-ray structure analysis results- monoclinic group c (no. 9), a = 25.5456(2) Å, b = 16.1469(1) Å, c = 31.9065(2) Å, β= 109.809(1)°, V = 12382.10(16) Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 153745 / 23656 / 1844, R1= 0.0824, wR2= 0.2337.

[0060] The single crystal structure of [SO⊂Cu₂(m-bbitrb)₄](BPB) is shown in Figure 2.

[0061] Example 3 The anion represented by formula (1) is the sodium salt of the anionic compound (NaHBCG), bromocresol green (CAS number 67763-24-0) to BCG. 2- was prepared.

[0062] The cation moiety of [SO⊂Cu(m-bbitrbNO)⊂]SO⊂·8H⊂O (m-bbitrbNO = 1,3-bis(benzimidazol-1-yl-methyl)-2,4,6-trimethyl-5-nitrobenzene) (complex 2) was used as the metal complex cation. m-bbitrb-NO⊂ was synthesized according to the method described in WO 2021 / 039929, and complex 2 was synthesized by reacting m-bbitrb-CNO⊂ with copper sulfate, CuSO⊂·5H⊂O.

[0063] <Synthesis of [SO⊂Cu2(m-bbitrb)4](BCG)> The raw material complex 2 was reacted with NaHBCG in the same manner as in Example 2. The single crystal X-ray analysis showed that the obtained ionic metal complex was BCG. 2- It was confirmed that the compound has the counter ion

[0064] -Single X-ray structural analysis results- triclinic, space group P-1 (no. 2), a = 17.57664(8) Å, b = 18.53780(9)Å, c = 23.49431(10) Å, α = 91.7254(4)°, β= 97.3044(4)°,γ = 113.4931(4)°, V = 6936.15(6)Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 90147 / 28346 / 2050, R1= 0.0518, wR2= 0.1421.

[0065] The single crystal structure of [SO⊂Cu₂(m-bbitrb)₄](BCG) is shown in Figure 3.

[0066] Example 4 The anion represented by formula (3) is the sodium salt of the anionic compound (NaIC), which is obtained by converting Indigo Carmine (cassino number 860-22-08) to IC. 2- was prepared.

[0067] [SO⊂Cu(m-bdbitrbNH)]SO was synthesized as starting complex 3. 1,3-bis(bromomethyl)-2,4,6-trimethyl-5-nitrobenzene was synthesized according to the method described in International Publication No. 2021 / 039929. Dimethyl benzimidazole (2.93 g, 20.0 mmol) and KOH (2.23 g, 40.0 mmol) were added to THF (100 ml) and stirred at room temperature for 4 hours. 1,3-bis(bromomethyl)-2,4,6-trimethyl-5-nitrobenzene (3.51 g, 10.0 mmol) was dissolved in THF (100 ml) and added dropwise to the solution, followed by stirring overnight at room temperature. The reaction solution was concentrated under reduced pressure, and the resulting residue was recrystallized from MeOH / H 2 O to obtain 1,3-bis(5,6-dimethylbenzimidazole-1-ylmethyl)-2,4,6-trimethylnitrobenzene as yellow crystals.

[0068] 1,3-bis(5,6-dimethylbenzimidazole-1-ylmethyl)-2,4,6-trimethylnitrobenzene (2.408 g, 5.00 mmol) and ammonium formate (3.16 g, 50.0 mmol) were dissolved in dry MeOH (200 ml) and Ar was bubbled through. 10% Pd / C (0.50 g) was added, Ar was stopped, and the mixture was stirred at room temperature overnight. The Pd / C was filtered, and the filtrate was concentrated. The target product was extracted into the dichloromethane layer with water (60 ml) / dichloromethane (70 × 3 ml). The mixture was dried over MgSO4, filtered, and the filtrate was concentrated under reduced pressure. Recrystallization from hot MeOH / H2O afforded 3,5-bis((5,6-dimethyl-benzoimidazol-1-yl)methyl)-2,4,6-trimethylaniline (m-bdbitrbNH2) as a white solid. m-bdbitrbNH2 (0.903 g, 2.00 mmol) was dissolved in 100 mL of THF, and CuSO4·5H2O (0.250 g, 1.00 mmol) was dissolved in 100 mL of MeOH. These solutions were mixed in a recovery flask to yield [SO4 ⊂ Cu2(m-bdbitrbNH2)4](SO4) as a blue powder. Single-crystal X-ray analysis confirmed the structure of the product.

[0069] -Single crystal X-ray structure analysis results- monoclinic, space group C2 / c (no. 15), a = 21.4198(5) Å, b = 37.4178(9)Å, c = 18.3567(4) Å,β= 90.761(2)°, V = 14711.3(6)Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 68515 / 17978 / 964, R1= 0.0605, wR2= 0.1940.

[0070] The crystal structure of [SO4⊂Cu2(m-bdbitrbNH2)4](SO4) (starting complex 3) is shown in Figure 4.

[0071] <Synthesis of [SO⊂Cu(m-bdmbitrbNH)](IC)> The starting complex 3 (0.5250 g, 0.200 mmol) was dissolved in 100 mL of DMF, and NaIC (0.0903 g, 0.200 mmol) was dissolved in 100 mL of water, and the mixture was stirred for 3 days to obtain a blue powder.

[0072] -Single crystal X-ray structure analysis results- triclinic, space group P-1 (no. 2), a = 14.3727(4) Å, b = 16.2589(5)Å, c = 17.6950(5) Å, α = 85.944(2)°, β= 84.517(2)°,γ = 69.766(3)°, V = 3859.0(2)Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 52693 / 15664 / 964, R1= 0.1232, wR2= 0.3696.

[0073] The crystal structure of [SO4⊂Cu2(m-bdmbitrbNH2)4](IC) is shown in Figure 5.

[0074] Example 5 The anion represented by formula (4) was synthesized as follows: the sodium salt of the anionic compound, sodium 4-(-(dimethylamino)styryl)benzenesulfonate (Nadmasbs). First, Hdmasbs was synthesized according to the method described in the literature (Chen et al. Chem. Lett. 2014, Vol. 43, 299-301), and then treated with an equimolar amount of NaOH to obtain Nadmasbs. - was prepared.

[0075] <Synthesis of [SO⊂Cu(m-bbitrbNH)](dmasbs)> [SO⊂Cu(m-bbitrbNH)]SO, synthesized by the method described in WO 2021 / 039929 4( Starting complex 4 (0.2064 g, 0.10 mmol) was dissolved in 50 mL of DMF. Nadmasbs (0.065 g, 0.20 mmol) in water (100 mL) was added and mixed, and the mixture was allowed to stand for 1 week. The resulting blue-green powder was collected by suction filtration. The structure of this product was confirmed by single-crystal X-ray analysis.

[0076] -Single crystal X-ray structure analysis results- triclinic, space group P-1 (no. 2), a = 14.2756(7) Å, b = 18.1280(9)Å, c = 29.1176(13) Å, α = 74.232(4)°, β= 76.782(4)°,γ = 68.970(4)°, V = 6696.2(6)Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 147071 / 35035 / 1874, R1= 0.0989, wR2= 0.2454.

[0077] The crystal structure of [SO4 ⊂ Cu2(m-bbitrbNH2)4](dmasbs)2 is shown in Figure 6.

[0078] Example 6 To obtain the anion represented by formula (6), the fluorescent dye sodium fluorescein (CAS number 518-47-8) (also known as uranine) Na2fs was prepared.

[0079] <Synthesis of [SO⊂Cu(m-bbitrbBr)⊂](Hfs)⊂> Starting complex 3 (0.243 g, 0.10 mmol) was dissolved in 50 mL of MeOH. Na2fs (0.0377 g, 0.10 mmol) was dissolved in 50 mL of water and mixed. The resulting brown powder was collected by suction filtration. The structure of this product was confirmed by single-crystal X-ray analysis.

[0080] -Single crystal X-ray structure analysis results- triclinic, space group P-1 (no. 2), a = 14.4881(3) Å, b = 15.1929(3)Å, c = 16.2975(4) Å, α = 67.971(2)°, β= 81.228(2)°,γ = 79.582 (2)°, V = 3256.49 (13)Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 79580 / 16776 / 897, R1= 0.0338, wR2= 0.0861.

[0081] The crystal structure of [SO⊂Cu₂(m-bbitrbBr)₄](Hfs)₂ is shown in Figure 7.

[0082] Example 7 The anion represented by formula (5) was prepared from the sodium salt of the anionic compound disodium 4,4'-bis(2-sulfonatostyryl)biphenyl (Na2BSSBP) (CAS number 27344-41-8) (Tokyo Chemical Industry Co., Ltd., Tokyo) to obtain DMABS. 2- was prepared.

[0083] <Synthesis of [SO⊂Cu(m-bbitrbNH)](bssbp)> [SO⊂Cu(m-bbitrbNH)](bssbp) was obtained as a light blue powder by reacting starting complex 4 with Nabsbbpb in the same manner as in Preparation Example 4. The structure of this product was confirmed by single crystal X-ray analysis.

[0084] -Single crystal X-ray structure analysis results- triclinic, space group P-1 (no. 2), a = 14.40220(10) Å, b = 19.3143(2)Å, c = 27.4316(3) Å, α = 70.9390(10)°, β= 85.5690(10)°,γ = 72.3890(10)°, V = 6872.25(13)Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 83745 / 28097 / 1860, R1= 0.1346, wR2= 0.3932.

[0085] The crystal structure of [SO⊂Cu2(m-bbitrbNH2)4](bssbp) is shown in Figure 8.

[0086] Example 8 As the metal complex cation represented by formula (8), ([Mn(salophen)] + ) (salophen = N,N''-bis-(3,5-di-tert-butyl-salicylidene)-1,2-phenylenediamine) and azo dye anion (MO - We synthesized a compound containing Mn(salophen)(MO). The anion of methyl orange (NaMO), which is used as a pH indicator, was used as the azo dye anion.

[0087] <Synthesis of starting material complex 5> [Mn(salophen)Cl] was used as the raw material complex 5 and synthesized according to the following procedure. The ligand, H2Salophen, was synthesized according to the literature method (J.-E. Backvall et al. Chem. Eur. J. 1999, 5, No. 5, 1460-1467). H2Salophen (0.27 g, 0.5 mmol) was dissolved in dichloromethane (15 mL), and triethylamine (10 drops) was added to the solution. MnCl2·4H2O (0.297 g, 1.5 mmol) dissolved in MeOH (15 mL) was added portionwise and stirred at room temperature for 6 h. The mixture was then separated into dichloromethane and brine. The dichloromethane layer was dried over MgSO4, filtered, and concentrated under reduced pressure to give [Mn(salophen)Cl] as a brown solid.

[0088] <Synthesis of [Mn(salophen)(MO)]> Starting complex 5 (0.0629 g, 0.100 mmol) was dissolved in 50 mL of DMF, and methyl orange (NaMO) (0.0327 g, 0.100 mmol) was dissolved in 50 mL of water. The resulting solution was stirred in a recovery flask for 7 days to obtain an orange powder of [Mn(salophen)(MO)]. The structure of the product was confirmed by single-crystal X-ray analysis.

[0089] -Single crystal X-ray structure analysis results- triclinic, space group P-1 (no. 2), a = 17.0623(3) Å, b = 20.4956(3)Å, c = 24.5727(4) Å, α = 17.0623(3)°, β= 88.656(2)°,γ = 87.4760(10)°, V = 8193.9(2)Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 86758 / 32369 / 2017, R1= 0.0559, wR2= 0.1635.

[0090] The crystal structure of [Mn(salophen)(MO)] is shown in Figure 9.

[0091] Example 9 As the metal complex cation represented by formula (8), ([Mn(salophen)] + ) and azo dye anion (MO - We synthesized a compound containing Mn(salophen)(MO). The anion of methyl orange BTB, which is used as a pH indicator, was used as the azo dye anion.

[0092] <Synthesis of [Mn(salophen)(BTB)]> Starting complex 5 (0.0629 g, 0.100 mmol) was dissolved in 50 mL of DMF, and NaBTB (0.0646 g, 0.100 mmol) was dissolved in 50 mL of water. The resulting solution was stirred in a recovery flask for 7 days to obtain [Mn(salophen)(BTB)] as a brown powder. The structure of the product was confirmed by single-crystal X-ray analysis.

[0093] -Single crystal X-ray structure analysis results- triclinic, space group P-1 (no. 2), a = 14.540(2) Å, b = 15.2992(2)Å, c = 16.3943(2) Å, α = 90.1740(10)°, β= 112.994(2)°,γ = 108.0050(10)°, V = 3159.37(9)Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 38056 / 12565 / 780, R1= 0.0365, wR2= 0.0985.

[0094] The crystal structure of [Mn(salophen)(BTB)] is shown in Figure 10.

[0095] Example 10 As the metal complex cation represented by formula (9), ([Mn(tpp)]+ ) (H2tpp = tetraphenylporphyrin), azo dye anions (MO - )-containing compound [Mn(tpp)(MO)] was synthesized.

[0096] <Synthesis of [Mn(tpp)(MO)]> [Mn(tpp)Cl] (CAS number 32195-55-4) was commercially available. [Mn(tpp)Cl] (0.070 g, 0.10 mmol) was dissolved in MeOH (20 mL) and Methyl Orange (NaMO) (0.031 g, 0.095 mmol) was dissolved in MeOH (20 mL). The mixture was slowly mixed and stirred at room temperature for 1 week. The reaction solution was then concentrated under reduced pressure, and the resulting crude product was dissolved in CHCl (50 mL). This solution was then filtered under suction to remove unreacted NaMO and the by-product NaCl. Hexane (200 mL) was added to the filtrate, and the mixture was allowed to stand for 30 min. The product was then filtered under suction to obtain the desired product as a greenish-brown powder. The structure of this product was confirmed by single-crystal X-ray analysis.

[0097] -Single crystal X-ray structure analysis results- tetragonal, space group P 42bc (no. 106), a = 32.138 (2) Å, c = 13.5662(5) Å, V = 14012.2 (18)Å 3 , T = 173 K, reflections collected / unique reflections / parameters refined: 43040 / 11370 / 633, R1= 0.1224, wR2= 0.3623

[0098] The crystal structure of [Mn(tpp)Cl] is shown in Figure 11.

[0099] (Anion detection test) Several 10.0 mL aqueous solutions containing various anions were prepared at a concentration of 1.0 mM. Additionally, ionic metal complexes were prepared in organic solvents to a concentration of 1.0 mM. These ionic metal complexes were added to the respective aqueous solutions containing the above anions. The anions used were sodium chloride (NaCl), sodium fluoride (NaF), sodium bromide (NaBr), sodium iodide (NaI), sodium sulfate pentahydrate (Na2SO4·5H2O), sodium nitrite (NaNO2), sodium nitrate (NaNO3), sodium dihydrogen phosphate dihydrate (NaH2PO4·2H2O), sodium acetate (CH3COONa) (AcONa), sodium perchlorate (NaClO4), sodium tetrafluoroborate (NaBF4), and sodium bicarbonate (NaHCO3). The reaction time was 30 minutes. The reaction solution was gently stirred at room temperature and then allowed to stand. HCO3 produced from NaHCO3 was analyzed. - In an aqueous solution, the concentration is lower than 1.0 mM because it is in equilibrium with the following reaction formula 2. However, in this case, the solution obtained by dissolving 1.0 mmol of NaHCO3 in 1.0 L of aqueous solution is considered to be 1.0 mM NaHCO3 or 1.0 mM HCO3. - The experiments were carried out using aqueous solutions. Each example and the detection or quantitative evaluation using the example will be described in detail below.

[0100] [ka]

[0101] <Detection of anions using [SO⊂Cu(m-bbitrb)⊂](BTB)⊂> Anion detection was performed using the ionic metal complex [SO⊂Cu⊂(m-bbitrb)⊂](BTB)⊂ described in Example 1. Anion-containing aqueous solutions were prepared by dissolving NaCl, NaF, NaBr, Na₂SO⊂, NaNO⊂, NaNO⊂, CH⊂COONa (NaAcO), NaI, NaH⊂PO⊂, and NaHCO⊂ in 1.0 mM DMF. 500 μL of the 1.0 mM solution of [SO⊂Cu⊂(m-bbitrb)⊂](BTB)⊂ prepared above in DMF was added to each of these solutions and ion-exchanged water, and the mixture was allowed to stand for 30 minutes. The solutions were then filtered through a syringe filter, and the color of the filtrates was compared. Photographs of each filtrate are shown in Figure 12. Only the solution containing sodium bicarbonate exhibited a visible color; essentially no color was observed in the other solutions or ion-exchanged water. This shows that bicarbonate ions in aqueous solution can be detected by using [SO4⊂Cu2(m-bbitrb)4](BTB)2.

[0102] <Detection and quantification of anions using [SO⊂Cu₂(m-bbitrb)₄](BPB)> The ionic metal complex [SO⊂Cu⊂(m-bbitrb)⊂](BPB) of Example 2 was used to detect and quantify anions. 1.0 mM aqueous solutions containing anions were prepared by dissolving Na⊂SO⊂, NaHCO⊂, NaBF⊂, NaBr, NaClO⊂, CH⊂COONa (NaAcO), NaH⊂PO⊂, NaF, NaNO⊂, NaI, NaNO⊂, and NaCl. 500 μL of the 1.0 mM DMF solution of [SO⊂Cu⊂(m-bbitrb)⊂](BPB)⊂ prepared above was added to each of these solutions and ion-exchanged water, gently stirred, and allowed to stand for 30 minutes. The solutions were then filtered through a syringe filter, and the color of the filtrates was compared. The sodium bicarbonate solution showed the strongest color, which could be confirmed visually. Photographs of the resulting filtrates are shown below. The visible-ultraviolet spectra of each solution were also measured. FIG. 13 shows a plot of the absorbance at the maximum absorption value (586 nm) versus the type of anion.

[0103] <Detection and quantification of anions using [SO⊂Cu₂(m-bbitrb)₄](BCG)> The ionic metal complex [SO⊂Cu∑(m-bbitrb)∑](BCG) of Example 3 was used to detect and quantify anions. 1.0 mM aqueous solutions containing anions were prepared by dissolving CH∑COONa(NaAcO), NaClO∑, NaBr, NaI, NaCl, NaF, NaNO∑, NaNO∑, Na∑SO∑, NaH∑PO∑, NaBF∑, and NaHCO∑. 500 μL of a solution containing [SO∑Cu∑(m-bbitrb)∑](BPB)∑ dissolved in an organic solvent to a concentration of 1.0 mM was added to each of these solutions and ion-exchanged water, and the mixture was allowed to stand for 30 minutes. The organic solvents used were DMF, methanol (MeOH), acetonitrile, 2-butanol, 2-ethoxyethanol, and 2-methoxyethanol. The aqueous solutions were then filtered through a syringe filter, and the color of the filtrates was compared. The aqueous solution obtained showed the strongest color with sodium bicarbonate, which could be confirmed by visual inspection. Photographs of the filtrate obtained when each organic solvent was used are shown in Figure 14. Also shown in Figure 14 is a plot of the absorbance at the maximum absorption value after measuring the visible-ultraviolet spectrum of each aqueous solution. The type of anion that produces color changes depending on the type of organic solvent used, and by utilizing this, it is possible to determine the type and quantity of anions contained in the aqueous solution. For example, if the solution turns green with 2-ethoxyethanol and is colorless with 2-methoxyethanol, this indicates that the anion is CH3COO - Alternatively, if the solution turns colorless in 2-butanol and blue in DMF, it is likely that the solution contains H2PO4 - It is clear that it contains

[0104] <Anion detection and quantification using [Mn(salophen)(MO)]> The ionic metal complex [Mn(salophen)(MO)] of Example 8 was used to detect and quantify anions. 10 mL of 1.0 mM aqueous solutions of NaF, NaCl, BaBr, NaI, Na2SO4, NaNO3, NaNO2, NaHPO4·2H2O, CH3COONa, NaClO4, and Na2CO3 were prepared. 500 μL of a 1.0 mM methanol solution of [Mn(salophen)(MO)] was added to each solution and 10 mL of ion-exchanged water prepared as a blank, and the mixture was stirred gently and allowed to stand for 30 minutes. The resulting precipitate was filtered through a syringe filter, and the resulting filtrate was observed. The visible-ultraviolet spectrum of each solution was measured to determine the absorbance at the absorption maximum. Photographs of the resulting filtrates and a plot of absorbance versus each anion are shown in Figure 15.

[0105] <Anion detection and quantification using [Mn(salophen)(BTB)]> The ionic metal complex [Mn(salophen)(BTB)] of Example 9 was used to detect and quantify anions. 1.0 mM aqueous solutions of NaF, NaCl, NaBr, NaI, Na2SO4, NaNO3, NaNO2, NaHPO4·2H2O, CH3COONa, NaClO4, and NaHCO3 were prepared. 500 μL of a 1.0 mM methanol solution of [Mn(salophen)(BTB)] was added to 10 mL of each solution and to 10 mL of ion-exchanged water (prepared as a blank). The mixture was gently stirred and allowed to stand for 30 minutes. The resulting precipitate was removed by filtration using a syringe filter. The filtrate was observed, and the visible-ultraviolet spectra of each solution were measured to determine the absorbance at the absorption maximum. The results are shown in Figure 16. Only the solution containing dissolved bicarbonate ions exhibited coloration, demonstrating that bicarbonate ions (and carbonate ions) could be detected.

[0106] <Anion detection using [Mn(tpp)(MO)]> The ionic metal complex [Mn(tpp)(MO)] of Example 10 was used to detect and quantify anions. 1.0 mM aqueous solutions of NaF, NaCl, NaBr, NaI, Na2SO4, NaNO3, NaNO2, NaHPO4·2H2O, CH3COONa, NaClO4, and NaHCO3 were prepared. 250 μL of a 1.0 mM [Mn(tpp)](MO) solution in 2(-2-methoxyethoxy)ethanol was added to 10 mL of each solution and to 10 mL of ion-exchanged water (prepared as a blank), followed by gentle stirring and allowing to stand for 30 minutes. The resulting precipitate was removed by filtration through a syringe filter, and the resulting filtrate was observed. The UV-visible spectra of each solution were also measured to determine the absorbance at the absorption maximum. The results are shown in Figure 17. The solution containing fluoride ions exhibited the strongest color, demonstrating its usefulness for detecting this anion.

[0107] <Determination of sodium bicarbonate ion by [SO⊂Cu₂(m-bbitrb)₄](BTB)₂> The ionic metal complex [SO⊂Cu⊂(m-bbitrb)⊂](BTB)⊂ described in Example 1 was used to detect and quantify sodium bicarbonate ions. 10 mL of 0.10 mM, 0.25 mM, 0.50 mM, 0.75 mM, 1.0 mM, and 2.0 mM NaHCO⊂ aqueous solutions were prepared. 500 μL of the 1.0 mM DMF solution of [SO⊂Cu⊂(m-bbitrb)⊂](BTB)⊂ prepared above was added to each solution and 10 mL of ion-exchanged water. The mixture was gently stirred and allowed to stand for 30 minutes. The solutions were then filtered through a syringe filter, and the color of the solutions was compared. A photograph of the filtrate is shown in Figure 18. Figure 19 shows the visible-ultraviolet absorption spectra of each solution, plotting the absorption maximum (616 nm) against the concentration of sodium bicarbonate ions in the solution. The absorbance increased linearly with the concentration of sodium bicarbonate in each aqueous solution, and it was confirmed that the bicarbonate ion in an aqueous solution can be quantified using this calibration curve of sodium bicarbonate aqueous solution using [SO⊂Cu₂(m-bbitrb)₄](BTB)₂.

[0108] <Determination of sodium bicarbonate ion using [Mn(salophen)(BTB)]> Sodium bicarbonate ion was quantified using the ionic metal complex [Mn(salophen)(BTB)] of Example 9. 10 mL of 0.10 mM, 0.25 mM, 0.50 mM, 0.75 mM, 1.0 mM, and 2.0 mM NaHCO3 aqueous solutions were prepared. 500 μL of the 1.0 mM DMF solution of [SO4⊂Cu2(m-bbitrb)4](BTB)2 prepared above was added to each solution and 10 mL of ion-exchanged water. The mixture was gently stirred and allowed to stand for 30 minutes. The solutions were then filtered through a syringe filter, and the color of the solutions was compared. A photograph of the filtrate is shown in Figure 20. Figure 21 shows the visible-ultraviolet absorption spectra of each solution, plotting the absorption maximum (616 nm) against the concentration of sodium bicarbonate ion in the solution.

[0109] Determination of anions in aqueous solution by adding solid powder of [SO⊂Cu₂(m-bbitrbNH₂)₄](dmasbs)₂ Anion quantification was performed using the ionic metal complex [SO⊂Cu(m-bbitrbNH)](dmasbs) of Example 5. 10 mL of 0.010 mM, 0.10 mM, and 1.0 mM sodium perchlorate solutions were prepared. 0.010 g of solid [SO⊂Cu(m-bbitrbNH)](dmasbs) was added to each solution and to a blank of ion-exchanged water. Each solution was shaken and stirred at 30°C for 24 hours using a thermostatic shaker. The precipitated complex was removed by filtration through a syringe filter. The filtrate was irradiated with UV light to examine its fluorescence, and the fluorescence spectrum of each filtrate was measured at 330 nm excitation. The emission intensity was confirmed to increase with the concentration of the anion, perchlorate ion. The results are shown in Figure 22.

[0110] <Determination of anions in aqueous solution by adding organic solvent solution of [SO⊂Cu₂(m-bbitrbNH₂)₄](dmasbs)₂> Anion quantification was performed using the ionic metal complex [SO⊂Cu₂(m-bbitrbNH₂)₄](dmasbs)₂ from Example 5. [SO⊂Cu₂(m-bbitrbNH₂)₄](dmasbs)₂ was dissolved in DMF to prepare a 1.0 mM solution. 500 μL of each complex solution was added to 10 mL of 1.0 mM, 0.10 mM, and 0.010 mM perchlorate ion solutions and ion-exchanged water (prepared as a blank) and allowed to stand. After one day, the precipitated complexes were filtered through a syringe filter, and the fluorescence was examined by UV irradiation. The fluorescence spectra of each filtrate were also measured at 330 nm excitation. The results are shown in Figure 23.

[0111] <Determination of anions in aqueous solution by adding a solvent solution of [SO⊂Cu₂(m-bbitrbNH₂)₄](dmasbs)₂> Anion quantification was performed using the ionic metal complex [SO⊂Cu₂(m-bbitrbNH₂)₄](dmasbs)₂ described in Example 5. [SO⊂Cu₂(m-bbitrbNH₂)₄](dmasbs)₂ was dissolved in DMF to prepare a 1.0 mM solution. 500 μL of each complex solution was added to 10 mL of 0.10 μM (0.00010 mM), 0.25 μM, 0.50 μM, 0.75 μM, and 1.0 μM sodium perchlorate aqueous solutions, and 10 mL of ion-exchanged water (blank) were added and allowed to stand. After one day, the precipitated complexes were filtered through a syringe filter, and the fluorescence was examined by UV irradiation. The fluorescence spectra of each solution were also measured at 330 nm excitation light. The same procedure was also performed using ultrapure water without perchlorate ions as a blank. The results are shown in Figure 24. Fluorescence was observed under ultraviolet light irradiation for perchlorate ions in the range of 0.1 μM (0.0001 mM) to 1.0 μM (0.001 mM), and the fluorescence intensity increased with concentration. Furthermore, since the fluorescence intensity increased in proportion to the concentration, it was demonstrated that perchlorate ions can be quantified in this low concentration range.

[0112] <Determination of anions in aqueous solution using [SO⊂Cu₂(m-bbitrbBr)₄](Hfs)₂> Anion quantification was performed using the ionic metal complex of Example 6. 5.0 mL of 0.010 mM, 0.050 mM, 0.10 mM, and 1.0 mM sodium perchlorate aqueous solutions were prepared, along with 5.0 mL of ion-exchanged water as a blank. 300 μL of a 1.0 mM THF solution (5.0 mL) of [SO⊂Cu₂(m-bbitrbBr)₄](Hfs)₂ was added to each solution. After standing for 1 hour, the solution was filtered through a syringe filter and the luminescence activity of the filtrate was examined. Clear coloration was observed even before UV irradiation for the 0.10 mM and 1.0 mM perchlorate ion aqueous solutions. At concentrations below 0.050 mM, almost no coloration was observed in the solutions before UV irradiation, but upon UV irradiation, all solutions, including the blank solution, exhibited weak fluorescence. The results are shown in Figure 25. Measurement of the fluorescence spectra of each filtrate revealed that there was almost no difference in the fluorescence intensity of aqueous solutions of perchlorate ions at concentrations of 0.050 mM or less, indicating that this method can quantify perchlorate ions at concentrations of 0.10 mM or more.

Claims

1. An ionic metal complex comprising a metal complex cation represented by the following formula (8) and an anion represented by the following formula (1): 【Chemistry 1】 [In formula (1), X １ ~X １２ each independently represents a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, or a methoxy group; R １ is OH or O ― It is. 【Chemistry 2】 [In formula (8), A 1 to A 14 each independently represent a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an aryl group, an n-butyl group, a tert-butyl group, a methoxy group, a halogen atom, a nitro group, an amino group, a substituted amino group, a hydroxy group, a carboxy group, a sulfonic acid group, or a methoxy group. M1 represents a trivalent metal ion.]

2. M 1 is Mn ３＋ , Al ３＋ , Co ３＋ or Fe ３＋ 2. The ionic metal complex of claim 1, wherein:

3. An anion detecting agent comprising the ionic metal complex of claim 1.

4. The detection agent according to claim 3 for detecting bicarbonate ions or carbonate ions.

5. Obtaining a mixture of an aqueous sample and the ionic metal complex according to claim 1 or 2 or the anion detecting agent according to claim 3 or 4; and A method for detecting anions in an aqueous sample, comprising the steps of detecting anions contained in the aqueous sample by any one of the following methods (i) to (iv) in this order: (i) Visually confirming the color of the mixture (ii) Measuring the visible and ultraviolet absorption spectrum of the mixture (iii) Measuring the fluorescence spectrum of the mixture (iv) a chemical reaction of the anions in the mixture.

6. Obtaining a mixture of an aqueous sample and the ionic metal complex according to claim 1 or 2 or the anion detecting agent according to claim 3 or 4; and A method for quantifying anions in an aqueous sample, comprising the steps of quantifying anions contained in the aqueous sample by any one of the following methods (i) to (iii) in this order: (i) Measurement of the visible and ultraviolet absorption spectrum of the mixture (ii) Measuring the fluorescence spectrum of the mixture (iii) a chemical reaction of the anions in the mixture.

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