Organic salt, device for detecting perfluoroalkyl compound, and method for detecting perfluoroalkyl compound

Abstract

This organic salt contains a fluorine-containing aromatic amine derivative (A) represented by formula (1) and a disulfonic acid compound (B) represented by formula (2). In formula (1), Ar1 is a substituted aromatic group that includes at least one fluorine atom, and Ar2 and Ar3 are each a substituted or unsubstituted aromatic group. In formula (2), X is a polycyclic aromatic hydrocarbon group, Y1 is a single bond or a group selected from the group consisting of an alkylene group, an alkenyl group, an alkynyl group and a phenylene group, and Y2 is a single bond or a group selected from the group consisting of an alkylene group, an alkenyl group, an alkynyl group and a phenylene group.

Description

Apparatus for detecting organic salts and perfluoroalkyl compounds, and method for detecting perfluoroalkyl compounds

[0001] The present invention relates to an apparatus for detecting organic salts and perfluoroalkyl compounds, and a method for detecting perfluoroalkyl compounds.

[0002] Organofluorine compounds have many useful and unique properties, such as the ability to simultaneously exhibit water and oil repellency and flame retardancy, and are widely used industrially. Among these, perfluoroalkyl compounds have been widely used in industrial products such as water and oil repellents, flame retardants, and fire extinguishing agents, as well as in their manufacturing processes. However, in recent years, potential health and environmental risks of perfluoroalkyl compounds have been identified, and their manufacture, use, etc. have been restricted.

[0003] However, to avoid adverse health and environmental effects caused by the release of already produced perfluoroalkyl compounds into the environment and their oral ingestion via drinking water or food, it is necessary to detect the perfluoroalkyl compounds and, if necessary, take measures such as removal or decomposition. Analytical methods for perfluoroalkyl compounds are described, for example, in JIS K 0450-70-10:2011 (Non-Patent Document 1), ISO 25101:2009 (Non-Patent Document 2), "Technical Considerations for the Treatment of PFOS- and PFOA-Containing Waste" (September 2022, Waste Control Division, Environmental Regeneration and Resource Recycling Bureau, Ministry of the Environment, Japan) (Non-Patent Document 3), and "OTM-45 Measurement of Selected Perfluoroalkyl and Polyfluoro Compounds from Stationary Flue Gas Sources, First Revised Edition" (January 14, 2025, United States Environmental Protection Agency) (Non-Patent Document 4).

[0004] JIS K 0450-70-10:2011 ISO 25101:2009 "Technical Considerations for the Treatment of PFOS and PFOA-Containing Waste" (September 2022, Waste Control Division, Environmental Regeneration and Resources Recycling Bureau, Ministry of the Environment) "OTM-45 Measurement of Selected Per- and Polyfluorinated Alkyl Substances from Stationary Sources, Rev. 1" (January 14, 2025, United States Environmental Protection Agency)

[0005] The detection methods for perfluoroalkyl compounds described in Non-Patent Documents 1 to 4 required complicated operations. Therefore, applying the detection methods described in Non-Patent Documents 1 to 4 to perfluoroalkyl compounds to be monitored at emission sources and the like was laborious, time-consuming, and costly.

[0006] Therefore, it is desirable to develop a detection device and detection method that can detect perfluoroalkyl compounds using a simpler method than conventional techniques, thereby enabling rational emission monitoring according to emission levels, as well as an organic salt that makes this possible.

[0007] The organic salt according to the present invention is an organic salt containing a fluorine-containing aromatic amine derivative (A) represented by formula (1) and a disulfonic acid compound (B) represented by formula (2), In formula (1), Ar １ is a substituted aromatic group containing at least one fluorine atom, and Ar ２ and Ar ３ is a substituted or unsubstituted aromatic group, and in formula (2), X is a polycyclic aromatic hydrocarbon group, and Y １ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group, and Y ２is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group.

[0008] The perfluoroalkyl compound detection device according to the present invention is a perfluoroalkyl compound detection device comprising: an organic salt unit containing an organic salt capable of including a perfluoroalkyl compound; an irradiator that irradiates the organic salt with ultraviolet light; and a detector that detects fluorescence emitted from the organic salt irradiated with ultraviolet light by the irradiator, wherein the organic salt contains a fluorine-containing aromatic amine derivative (A) represented by formula (1) and a disulfonic acid compound (B) represented by formula (2), In formula (1), Ar １ is a substituted aromatic group containing at least one fluorine atom, and Ar ２ and Ar ３ is a substituted or unsubstituted aromatic group, and in formula (2), X is a polycyclic aromatic hydrocarbon group, and Y １ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group, and Y ２ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group.

[0009] The method for detecting a perfluoroalkyl compound according to the present invention comprises the steps of: bringing an organic salt into contact with an analyte; irradiating the organic salt that has been brought into contact with the analyte with ultraviolet light and detecting fluorescence emitted by the organic salt; and determining the presence or absence of a perfluoroalkyl compound in the analyte based on the wavelength of the fluorescence, wherein the organic salt comprises a fluorine-containing aromatic amine derivative (A) represented by formula (1) and a disulfonic acid compound (B) represented by formula (2): In formula (1), Ar １ is a substituted aromatic group containing at least one fluorine atom, and Ar ２ and Ar ３ is a substituted or unsubstituted aromatic group, and in formula (2), X is a polycyclic aromatic hydrocarbon group, and Y １is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group, and Y ２ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group.

[0010] The organic salt according to the above configuration can selectively include perfluoroalkyl compounds. Furthermore, the organic salt according to the above configuration exhibits a different fluorescence spectrum depending on whether or not a perfluoroalkyl compound is included. Therefore, by observing the fluorescence spectrum of the organic salt according to the above configuration, perfluoroalkyl compounds can be easily detected. Therefore, by configuring a perfluoroalkyl compound detection device and detection method using the organic salt according to the above configuration, perfluoroalkyl compounds can be detected by a simpler method than conventional techniques.

[0011] Preferred embodiments of the present invention will be described below, but the scope of the present invention is not limited to the preferred embodiments described below.

[0012] In one embodiment of the organic salt according to the present invention, the fluorine-containing aromatic amine derivative (A) is a fluorine-containing triphenylamine derivative represented by formula (1a): In formula (1a), R １ , R ２ , and R ３ At least one of the groups is a fluorine-containing group containing at least one fluorine atom.

[0013] According to this configuration, the organic salt particularly easily includes the perfluoroalkyl compound, which makes it easy to detect the perfluoroalkyl compound.

[0014] In one embodiment, the organic salt according to the present invention comprises Ar １ However, it is preferably a substituted aromatic group in which at least one hydrogen atom is substituted with a fluorine atom or a fluoroalkyl group.

[0015] According to this configuration, the organic salt particularly easily includes the perfluoroalkyl compound, which makes it easy to detect the perfluoroalkyl compound.

[0016] In one embodiment of the organic salt according to the present invention, in formula (2), X is preferably a polycyclic aromatic hydrocarbon group having 2 to 5 aromatic rings.

[0017] According to this configuration, the organic salt tends to emit clear fluorescence, making it easier to detect the perfluoroalkyl compound.

[0018] In one embodiment of the organic salt according to the present invention, the disulfonic acid compound (B) in formula (2) is preferably 1,8-disulfoanthracene.

[0019] According to this configuration, the change in the fluorescence spectrum depending on the presence or absence of the perfluoroalkyl compound becomes particularly significant, making it easier to detect the perfluoroalkyl compound.

[0020] In one embodiment, the organic salt according to the present invention is preferably a crystal obtained by removing at least a part of the template compound (C) from a crystal containing the fluorine-containing aromatic amine derivative (A), the disulfonic acid compound (B), and at least one template compound (C) selected from the group consisting of benzene, chlorobenzene, toluene, chlorotoluene, dichlorobenzene, trichlorobenzene, anisole, methyl benzoate, xylene, mesitylene, nitrobenzene, benzonitrile, tetrahydrofuran, dioxane, methanol, dimethylformamide, and dimethyl sulfoxide.

[0021] According to this configuration, the organic salt particularly easily includes the perfluoroalkyl compound, which makes it easy to detect the perfluoroalkyl compound.

[0022] Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments, which is given with reference to the drawings.

[0023] FIG. 1 is a schematic diagram showing a partial structure of a supramolecular cluster in an organic salt according to an embodiment. FIG. 2 is a diagram showing an example of the crystalline structure of an organic salt according to Example 1. FIG. 3 is a diagram showing an example of the crystalline structure of an organic salt according to Example 2. FIG. 4 is a diagram showing an example of the crystalline structure of an organic salt according to Example 3. FIG. 5 is a diagram showing an example of the crystalline structure of an organic salt according to Example 5. FIG. 6 is a diagram showing fluorescence spectra according to Example 3A, Comparative Example 3A, and Comparative Example 3B. FIG. 7 is a diagram showing fluorescence spectra according to Example 6A, Comparative Example 6A, and Comparative Example 6B. FIG. 8 is a diagram showing fluorescence spectra according to Example 7A, Comparative Example 7A, and Comparative Example 7B. FIG. 9 is a diagram showing fluorescence spectra according to Example 8A, Comparative Example 8A, and Comparative Example 8B. FIG. 10 is a diagram showing fluorescence spectra according to Example 9A and Comparative Example 9B. FIG. 11 is a schematic diagram showing the configuration of a perfluoroalkyl compound detection device according to an embodiment.

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an organic salt, a perfluoroalkyl compound detection device, and a perfluoroalkyl compound detection method according to the present invention will be described with reference to the drawings.

[0025] [Constitution of Organic Salt] The organic salt according to this embodiment contains a fluorine-containing aromatic amine derivative (A) represented by formula (1) and a disulfonic acid compound (B) represented by formula (2).

[0026] The organic salt according to this embodiment is a composition having a network structure in which a fluorine-containing aromatic amine derivative (A) and a disulfonic acid compound (B) are bonded by hydrogen bonds.

[0027] (Fluorine-containing aromatic amine derivative) The fluorine-containing aromatic amine derivative (A) according to this embodiment is represented by formula (1). １ is a substituted aromatic group containing at least one fluorine atom, and Ar ２ and Ar ３ is a substituted or unsubstituted aromatic group.

[0028] Ar １is an aromatic group having at least one substituent containing a fluorine atom. Such an aromatic group may be a phenyl group, a pyridyl group, a pyrimidyl group, a pyridazyl group, a pyrazyl group, a pyrrolyl group, a pyrazolyl group, an imidazolyl group, a furanyl group, a thiophenyl group, or the like. The substituent containing a fluorine atom may be, but is not limited to, a fluorine atom and a fluoroalkyl group. Ar １ The number of substituents containing fluorine atoms that Ar has is arbitrary. １ When Ar has a plurality of substituents containing a fluorine atom, some or all of the substituents may be the same group, or all of the substituents may be different groups. １ However, it is not prohibited to have a substituent that does not contain fluorine. Examples of such a substituent include, but are not limited to, an alkyl group (e.g., a methyl group, an ethyl group), an alkenyl group (e.g., an ethenyl group), an alkynyl group (e.g., an ethynyl group), a chloro group, a bromo group, an iodo group, a nitrile group, a hydroxy group, a methoxy group, a carboxy group, an ester group, an amino group, and an amide group.

[0029] Ar ２ and Ar ３ is a substituted or unsubstituted aromatic group. Such aromatic groups may be phenyl, pyridyl, pyrimidyl, pyridazyl, pyrazyl, pyrrolyl, pyrazolyl, imidazolyl, furanyl, thiophenyl, etc. １ , Ar ２ , and Ar ３ The aromatic groups in Ar are each independently selected, and some or all of them may be the same aromatic group, or all may be different aromatic groups. ２ and Ar ３ When Ar has a substituent, the substituent is not limited, and may be any of non-fluorine-based substituents such as alkyl groups (e.g., methyl groups, ethyl groups), alkenyl groups (e.g., ethenyl groups), alkynyl groups (e.g., ethynyl groups), chloro groups, bromo groups, iodo groups, nitrile groups, hydroxy groups, methoxy groups, carboxy groups, ester groups, amino groups, and amide groups, as well as fluorine-based substituents such as fluorine atoms and fluoroalkyl groups. ２ and Ar ３One or both of １ In this case, Ar may be a substituted aromatic group containing at least one fluorine atom, as defined above. １ , Ar ２ , and Ar ３ may be the same group partially or entirely, or may all be different groups.

[0030] The fluorine-containing aromatic amine derivative (A) is preferably a fluorine-containing triphenylamine derivative represented by formula (1a). Formula (1a) is a compound represented by formula (1) in which Ar １ , Ar ２ , and Ar ３ and R are phenyl groups each having at least one substituent containing a fluorine atom. １ , R ２ , and R ３ In other words, the fluorine-containing triphenylmethylamine derivative represented by formula (1a) is a triphenylmethylamine derivative containing at least one fluorine atom at the para-position or meta-position of the phenyl group.

[0031] The fluorine-containing group is not limited as long as it is a functional group containing a fluorine atom. Non-limiting examples of the fluorine-containing group include a fluorine atom, a fluoroalkyl group, etc. The fluorine-containing group is preferably a fluorine atom or a fluoroalkyl group, more preferably a fluorine atom or a fluoromethyl group, and particularly preferably a fluorine atom or a trifluoromethyl group.

[0032] R １ , R ２ , and R ３ There is no limitation as to which of R １ Only the phenyl group has a fluorine-containing group (the para-position of the phenyl group has a fluorine-containing group), R ２ only a fluorine-containing group (only one meta position of the phenyl group is a fluorine-containing group), R ２ and R ３ only has a fluorine-containing group (only both meta positions of the phenyl group have a fluorine-containing group), R１ and R ２ only the para-position and one meta-position of the phenyl group are fluorine-containing groups, and R １ , R ２ , and R ３ and all of the above may be fluorine-containing groups (fluorine-containing groups at the para-position and both meta-positions of the phenyl group).

[0033] R １ , R ２ , and R ３ Among R, the non-fluorine-containing groups are any groups that do not contain fluorine atoms and can be independently selected. Examples of such groups include, but are not limited to, hydrogen atoms, alkyl groups (e.g., methyl groups, ethyl groups), alkenyl groups (e.g., ethenyl groups), alkynyl groups (e.g., ethynyl groups), chloro groups, bromo groups, iodo groups, nitrile groups, hydroxy groups, methoxy groups, carboxy groups, ester groups, amino groups, and amide groups. １ , R ２ , and R ３ Among these, the group that is not a fluorine-containing group is preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom.

[0034] R ４ and R ５ can be any group, i.e., R ４ and R ５ may be a group containing a fluorine atom or a group not containing a fluorine atom. Non-limiting examples of groups containing a fluorine atom include a fluorine atom and a fluoroalkyl group. Non-limiting examples of groups not containing a fluorine atom include a hydrogen atom, an alkyl group (e.g., a methyl group, an ethyl group), an alkenyl group (e.g., an ethenyl group), an alkynyl group (e.g., an ethynyl group), a chloro group, a bromo group, an iodo group, a nitrile group, a hydroxy group, a methoxy group, a carboxy group, an ester group, an amino group, an amide group, etc. From the viewpoint of reducing the steric hindrance between the three phenyl groups, R ４ and R ５ is preferably a fluorine atom or a hydrogen atom.

[0035] Specific examples (A1) to (A5) of the fluorine-containing aromatic amine derivative (A) are shown below: A1: tris(4-fluorophenyl)methylamine A2: tris(3,5-difluorophenyl)methylamine A3: tris(3,4,5-trifluorophenyl)methylamine A4: tris(pentafluorophenyl)methylamine A5: tris(4-trifluoromethylphenyl)methylamine A6: 3,4,5-trifluorophenyldiphenylmethylamine

[0036] (Disulfonic Acid Compound) The disulfonic acid compound (B) according to this embodiment is represented by formula (2).

[0037] In formula (2), X is a polycyclic aromatic hydrocarbon group. This polycyclic aromatic hydrocarbon group may or may not contain a heteroatom. Non-limiting examples of polycyclic aromatic hydrocarbon groups include naphthyl, anthracenyl, o-terphenyl, m-terphenyl, p-terphenyl, phenanthrenyl, tetracenyl, pyrenyl, triphenylenyl, chrysenyl, pentacenyl, benzopyrenyl, perylenyl, corannulenyl, and coronenyl groups. Note that for any of the polycyclic aromatic polycyclic hydrogen groups, -Y １ -SO ３ H and -Y ２ -SO ３ There are no limitations on the combination of substitution positions of H. X is preferably a polycyclic aromatic hydrocarbon group having 2 to 5 aromatic rings, and particularly preferably an anthracenyl group.

[0038] In formula (2), Y １ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group; Y ２ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group. １ and Y ２may be the same or different groups, but are preferably the same group. Examples of alkylene groups include, but are not limited to, methylene, ethylene, and propylene groups. Examples of alkenyl groups include, but are not limited to, ethenyl, propenyl, and butenyl groups. Examples of alkynyl groups include, but are not limited to, ethynyl, propynyl, and butynyl groups.

[0039] Y １ and Y ２ However, if Y is a group that forms a conjugate with the polycyclic aromatic hydrocarbon group X, it is preferable because the ability to detect perfluoroalkyl compounds is likely to be enhanced. Details will be described later. Examples of such groups include alkenyl groups and alkylene groups. １ and Y ２ are more preferably all alkenyl groups, and particularly preferably all ethenyl groups.

[0040] Specific examples (B1) and (B2) of the disulfonic acid compound (B) are shown below: B1: 9,10-bis(2-sulfoethenyl)anthracene B2: 1,8-disulfoanthracene

[0041] As shown in the Examples below, it has been found that when the disulfonic acid compound (B) is 1,8-disulfoanthracene, the ability to detect perfluoro compounds is high. Therefore, it is preferable that the disulfonic acid compound (B) is 1,8-disulfoanthracene.

[0042] (Template Compound) The organic salt according to this embodiment may be preferably produced using a template compound (C). The template compound (C) is preferably at least one compound selected from the group consisting of benzene, chlorobenzene, toluene, chlorotoluene, dichlorobenzene, trichlorobenzene, anisole, methyl benzoate, xylene, mesitylene, nitrobenzene, benzonitrile, tetrahydrofuran, dioxane, methanol, dimethylformamide, and dimethyl sulfoxide. Even when the combination of the fluorine-containing aromatic amine derivative (A) and the disulfonic acid compound (B) is the same, the network structure of the organic salt may vary depending on the type and presence or absence of the template compound (C).

[0043] (Structure and Function of Organic Salt) As described above, the organic salt according to this embodiment is a composition in which a fluorine-containing aromatic amine derivative (A) and a disulfonic acid compound (B) form a network structure. The template compound (C), which is optionally used when producing the organic salt, penetrates into the gaps in the network structure when the fluorine-containing aromatic amine derivative (A) and the disulfonic acid compound (B) form the network structure, thereby defining the network structure. The network structure of the organic salt will be described below.

[0044] In the organic salt, the amino group of the fluorine-containing aromatic amine derivative (A) and the sulfo group of the disulfonic acid compound (B) form a hydrogen bond. ３ ＋ ) and a sulfo group (―SO ３ － ) can form hydrogen bonds in three directions. This results in the formation of a supramolecular cluster centered on a three-dimensional hydrogen-bonding unit in which amino groups and sulfo groups are alternately arranged at each vertex of a cube (Figure 1). Disulfonic acid compound (B) has two sulfo groups per molecule, and each of the two sulfo groups participates in the formation of a different supramolecular cluster. Therefore, the supramolecular clusters are connected to each other via the disulfonic acid compound (B). In this way, the organic salt according to this embodiment has a continuous structure in which the supramolecular clusters are connected by the disulfonic acid compound (B).

[0045] The organic salt forms a crystal in which the above-mentioned supramolecular clusters are self-assembled. The arrangement of the supramolecular clusters is determined by factors such as the molecular structure of the fluorine-containing aromatic amine derivative (A), the molecular structure of the disulfonic acid compound (B), and whether or not a template compound (C) is used and its molecular structure. As an example, the crystal structure of an organic salt containing a fluorine-containing aromatic amine derivative (A1) (tris(4-fluorophenyl)methylamine) and a disulfonic acid compound (B1) (9,10-bis(2-sulfoethenyl)anthracene) is shown in Figures 2 and 3. Figure 2 shows an organic salt produced without using the template compound (C), and has almost no voids in its crystal structure. Figure 3 shows an organic salt produced using toluene as the template compound (C), and shows a crystal structure with regularly spaced voids (V).

[0046] In the example of Figure 3, the fluorine-containing groups (fluorine atoms in this example) of the fluorine-containing aromatic amine derivative (A1) are arranged in the voids V, and the voids V are spaces where the fluorine atoms are exposed. As in this example, spaces rich in fluorine atoms are formed in the crystals of the organic salt. The fluorine-atom-rich spaces have selective affinity for guest compounds that are also rich in fluorine atoms, and are easy to include (take in) molecules of the guest compounds. Non-limiting examples of guest compounds that can be included in the organic salts of this embodiment include perfluoroalkyl compounds such as perfluoroalkylsulfonic acids and perfluoroalkyl acids.

[0047] The organic salt exhibits fluorescent behavior derived from the polycyclic aromatic hydrocarbon group X of the disulfonic acid compound (B). When the organic salt is irradiated with ultraviolet light, it emits fluorescence, the wavelength of which is related to the molecular structure of the disulfonic acid compound (B). The wavelength of the fluorescence emitted by the organic salt also depends on the presence or absence of a guest compound. This is because the electronic state of the disulfonic acid compound (B) changes when a guest compound is placed in the vicinity of the disulfonic acid compound (B).

[0048] In addition, the group Y of the disulfonic acid compound (B) １ and group Y ２is a group capable of forming a conjugated system with the polycyclic aromatic hydrocarbon group X, the conformation of the disulfonic acid compound (B) changes depending on the presence or absence of a guest compound, thereby varying the extent of the conjugated system. For example, in the disulfonic acid compound (B1) (see below), the single bond a １ , a ２ can rotate freely, resulting in conformational changes.

[0049] double bond b １ , b ２ In the conformation where the double bond b is not coplanar with the anthracenyl group, a conjugated system containing only the anthracenyl group is formed. １ , b ２ In the conformation where the double bond b is coplanar with the anthracenyl group, １ , b ２ and an anthracenyl group. The latter conjugated system is wider than the former, so the fluorescence wavelength when the latter conformation is adopted is longer than when the former conformation is adopted.

[0050] In the organic salt containing the disulfonic acid compound (B1), when the guest compound is not included, the disulfonic acid compound (B1) has a double bond b １ , b ２ When a guest compound is included, the single bond a is sterically hindered by the anthracenyl group. １ , a ２ Rotation of the double bond b occurs. １ , b ２ The anthracenyl group is coplanar with the anthracenyl group.

[0051] Due to the above factors, the wavelength of the fluorescence emitted by the organic salt changes depending on the presence or absence of guest molecules. Specifically, the wavelength of the fluorescence emitted by an organic salt that includes guest molecules is longer than the wavelength of the fluorescence emitted by an organic salt that does not include guest molecules. １ and group Y ２is a group capable of forming a conjugated system together with the polycyclic aromatic hydrocarbon group X, the difference in fluorescence wavelength depending on the presence or absence of a guest molecule tends to become large because the second factor (a change in the conjugated system of the disulfonic acid compound (B) due to the guest molecule) contributes in addition to the first factor (a change in the electronic state of the disulfonic acid compound (B) due to the approach of the guest molecule).

[0052] For example, the peak wavelength of fluorescence emitted by an organic salt is 400 to 600 nm when no guest molecules are included, and when a guest molecule is included, the peak appears at a different wavelength than when no guest molecules are included. For example, the peak wavelength of fluorescence emitted by an organic salt containing a fluorine-containing triphenylmethylamine derivative (A1) (tris(4-fluorophenyl)methylamine) and a disulfonic acid compound (B1) (9,10-bis(2-sulfoethenyl)anthracene) is 470 nm when no guest molecules are included, and 530 nm when guest molecules are included. Furthermore, the peak wavelength of fluorescence emitted by an organic salt containing a fluorine-containing triphenylmethylamine derivative (A1) and a disulfonic acid compound (B2) (1,8-disulfoanthracene) is 520 nm when no guest molecules are included, and 460 nm when guest molecules are included. As can be seen from these examples, whether the peak wavelength shifts to a longer wavelength or a shorter wavelength due to the inclusion of a guest molecule can vary depending on conditions such as the combination of the fluorine-containing aromatic amine derivative (A) and the disulfonic acid compound (B). The peak wavelength of the fluorescence emitted by the organic salt refers to the wavelength at which the fluorescence intensity is maximum in the fluorescence spectrum measured by fluorescence spectroscopy at an excitation wavelength of 365 nm using a spectrofluorometer (such as the FP-8500 manufactured by JASCO Corporation).

[0053] The organic salt according to this embodiment is preferably a crystal obtained by removing at least a part of the template compound (C) from a crystal containing the fluorine-containing aromatic amine derivative (A), the disulfonic acid compound (B), and the template compound (C).

[0054] Crystals (first crystals) containing a fluorinated aromatic amine derivative (A), a disulfonic acid compound (B), and a template compound (C) can be obtained, for example, by gradually removing the solvent from a solution containing the fluorinated aromatic amine derivative (A), the disulfonic acid compound (B), and the template compound (C). This process results in crystals having a crystalline structure in which the template compound (C) is inserted into the network structure formed by the fluorinated aromatic amine derivative (A) and the disulfonic acid compound (B). The template compound (C) can be removed from the obtained crystals by, for example, contacting the crystals with supercritical carbon dioxide using a supercritical fluid extraction apparatus. This process results in crystals (second crystals) from which at least a portion of the template compound (C) has been removed. The second crystals obtained by the above procedure have voids corresponding to the spaces occupied by the template compound (C) in the first crystals, and therefore have a higher porosity than crystals of an organic salt produced without the template compound (C). That is, the crystals of the organic salt obtained by the above procedure tend to have a high porosity, which is suitable for the inclusion of guest compounds.

[0055] The crystalline structure of an organic salt produced using template compound (C) is difficult to determine uniquely because it depends on conditions such as the type and amount of template compound (C), the temperature, humidity, and atmosphere used to obtain the first crystals, and the medium and temperature used to remove at least a portion of template compound (C). Therefore, it is not practical to directly identify an organic salt produced using template compound (C) based on its structure or properties. However, the present inventors experimentally confirmed that organic salts produced using template compound (C) actually have high porosity and are advantageous in the inclusion of perfluoroalkyl compounds, thereby completing the present invention. For more information on this point, please refer to the Examples below.

[0056] [Perfluoroalkyl compound detection device and detection method] The perfluoroalkyl compound detection device 1 according to this embodiment (hereinafter simply referred to as the detection device 1) comprises an organic salt unit 2, an irradiator 3, a detector 4, and a control device 5 (Figure 12).

[0057] The organic salt unit 2 contains the above-mentioned organic salt. That is, the organic salt unit 2 contains an organic salt that can include a perfluoroalkyl compound. As an example, the organic salt unit 2 has a configuration in which an organic salt 22 is placed in a sample chamber 21. A test specimen 23 can be placed in the sample chamber 21.

[0058] The irradiator 3 is a device that irradiates the organic salt 22 of the organic salt unit 2 with ultraviolet light. The ultraviolet light emitted by the irradiator 3 is not limited as long as it is ultraviolet light that can cause the organic salt 22 to emit fluorescence, and may be, for example, ultraviolet light with a wavelength of 365 nm. The irradiator 3 may be a known UV-A light source. The type of ultraviolet light source is not limited, and may be, for example, an ultraviolet lamp or an ultraviolet LED.

[0059] The detector 4 is a device that detects the fluorescence emitted by the organic salt 22 of the organic salt unit 2. The detector 4 can be a known device such as a spectrofluorophotometer (for example, the FP-8500 manufactured by JASCO Corporation) or an image analyzer (for example, the Image Checker PV200 manufactured by Panasonic Corporation). When a spectrofluorophotometer is used as the detector 4, the amount of the perfluoroalkyl compound can be quantified based on a quantitative evaluation of the intensity of the detected fluorescence. When an image analyzer is used as the detector 4, the amount of the perfluoroalkyl compound can be quantified based on the distribution of RGB values ​​of each pixel in an image captured of the organic salt 22 in a fluorescent state.

[0060] The control device 5 is a device that controls each part of the detection device 1, and may be a known device having arithmetic processing capabilities, such as a personal computer or a microcontroller. The control device 5 performs processes such as starting and stopping ultraviolet irradiation by the irradiator 3, and processing data (spectrum drawing, peak detection, etc.) of the detection results by the detector 4. The control device 5 may include a calculation device such as a CPU, a user interface device such as a keyboard or a liquid crystal display, a storage device such as a hard disk drive, etc.

[0061] The method for detecting perfluoroalkyl compounds according to this embodiment includes the steps of contacting an organic salt with a test specimen, detecting fluorescence emitted by the organic salt, and determining the presence or absence of perfluoroalkyl compounds based on the wavelength of the fluorescence. Hereinafter, an example will be described in which the above-described detection device 1 is used to determine the presence or absence of perfluoroalkyl compounds in a test specimen whose presence or absence of perfluoroalkyl compounds is unknown.

[0062] The step of contacting the organic salt with the analyte is achieved by placing the analyte 23 in the organic salt unit 2. If the analyte 23 is a gas, the analyte 23 is introduced into the sample chamber 21 using piping or the like. In an example where the analyte 23 is a gas, an inlet pipe and an outlet pipe are provided in the sample chamber 21, and the gas of the analyte 23 that has undergone necessary pretreatment is introduced into the sample chamber 21 through the inlet pipe, filling the sample chamber 21 with the gas, thereby achieving contact between the organic salt 22 and the analyte 23. An example of the analyte 23 that is a gas is, but is not limited to, the exhaust gas from an incinerator. Examples of pretreatment of the analyte 23 include treatments to remove substances (such as soot and moisture) that may inhibit the detection of perfluoroalkyl compounds, and treatments (such as temperature adjustment and flow rate adjustment) for introducing the analyte 23 into the sample chamber 21 under certain conditions. Furthermore, an activated carbon adsorption column or the like may be provided in the outlet pipe to prevent perfluoroalkyl compounds contained in the specimen 23 from leaking out of the system.

[0063] If the analyte 23 is solid, placing the analyte 23 in the sample chamber 21 allows the perfluoroalkyl compound volatilized from the analyte 23 to come into contact with the organic salt 22. Treatment such as heating may be performed to promote volatilization from the analyte. If the analyte 23 is liquid, the organic salt and the analyte can be brought into contact with each other by a method such as placing a container containing the analyte 23 in the sample chamber 21, providing an open flow path in the sample chamber 21 through which the analyte 23 flows continuously, or immersing the organic salt 22 in the analyte 23 placed in the sample chamber 21.

[0064] The inventors' investigations have revealed that the organic salt and perfluoroalkyl compound according to the above embodiment can form a clathrate simply by being in close proximity to each other, even without any visible contact (see the Examples below). This is thought to be because the perfluoroalkyl compound vaporized by evaporation or sublimation is included in the organic salt. Therefore, the step of contacting the organic salt with the analyte does not require any visible contact between the organic salt and the analyte, but can be said to be a step of contacting the organic salt and the analyte at the molecular level.

[0065] The process of irradiating ultraviolet light onto the organic salt 22 that has been brought into contact with the specimen 23 and detecting the fluorescence emitted by the organic salt 22 is achieved by irradiating ultraviolet light onto the organic salt 22 from the irradiator 3 and detecting the fluorescence emitted by the organic salt 22 with the detector 4. As described above, the start and stop of ultraviolet light irradiation by the irradiator 3 and the data processing of the detection results by the detector 4 are controlled by the control device 5.

[0066] The step of determining the presence or absence of a perfluoroalkyl compound in the analyte 23 based on the wavelength of the fluorescence is realized by arithmetic processing by the control device 5. The control device 5 pre-stores the peak wavelength of fluorescence when the analyte 23 does not contain a perfluoroalkyl compound as a standard value, identifies the peak wavelength of the fluorescence detected by the detector 4 (measured value), and compares it with the standard value. Since the wavelength of the fluorescence emitted by the organic salt 22 that has encapsulated a guest molecule differs from the wavelength of the fluorescence emitted by the organic salt 22 that has not encapsulated a guest molecule, a difference between the measured value and the standard value indicates that the organic salt 22 has encapsulated a guest molecule. In this case, it is determined that the analyte 23 contains a guest molecule, i.e., a perfluoroalkyl compound. More specifically, the presence or absence of a perfluoroalkyl compound in the analyte 23 is determined based on the magnitude relationship between the difference between the measured value and the standard value and a predetermined threshold.

[0067] EXAMPLES The present invention will be further described below by way of examples, but the present invention is not limited to these examples.

[0068] (1) Synthesis of Fluorine-Containing Aromatic Amine Derivative (A) Fluorine-containing aromatic amine derivatives (A1) to (A6) were synthesized by the following procedure. The fluorine-containing aromatic amine derivatives (A1) to (A6) are the same as those exemplified above, but will be listed again. The fluorine-containing aromatic amine derivatives (A1) to (A5) are fluorine-containing triphenylamine derivatives, and will be referred to as fluorine-containing triphenylamine derivatives (A1) to (A5), respectively. A1: tris(4-fluorophenyl)methylamine A2: tris(3,5-difluorophenyl)methylamine A3: tris(3,4,5-trifluorophenyl)methylamine A4: tris(pentafluorophenyl)methylamine A5: tris(4-trifluoromethylphenyl)methylamine A6: 3,4,5-trifluorophenyldiphenylmethylamine

[0069] (1-1) Synthesis of Fluorine-Containing Triphenylmethylamine Derivative (A1) Tris(4-fluorophenyl)bromomethane (1.00 g, 2.65 mmol) and dichloromethane (80 mL) were added to an aqueous ammonia solution (30% by mass, 30 mL) containing ammonium chloride (1.40 g, 26.2 mmol) at 0°C. The mixture was stirred at 25°C for 6 hours. An aqueous sodium pyrosulfite solution was added to the mixture to quench the reaction. The product was extracted with dichloromethane and water and then purified by column chromatography using silica gel as the stationary phase and dichloromethane as the mobile phase to obtain a pale yellow solid. １ H NMR and １３ The product was identified as tris(4-fluorophenyl)methylamine by C NMR. １ H NMR (400 MHz, deuterated chloroform, δ): 7.22 (dd, J = 8.8 Hz, 6H), 7.04 (t, J = 8.8 Hz, 6H) １３ C NMR (400 MHz, deuterated chloroform, δ): 161.6, 144.1, 129.6, 114.8, 65.1

[0070] (1-2) Synthesis of Other Fluorine-Containing Triphenylmethylamine Derivatives (A2) to (A5) The synthesis routes of the fluorine-containing triphenylmethylamine derivatives (A2) to (A5) are shown below. １ ~R ５ Regardless of the method, the synthetic route is the same, so the synthetic method is shown below in a generalized form.

[0071] A diethyl ether solution of the fluorine-containing bromide bromobenzene derivative (Aa) was cooled to -78°C, and a hexane solution of n-butyllithium (1.6 M) was added dropwise thereto. The mixture was stirred for 2 hours, and then diethyl carbonate was further added dropwise thereto. The mixture was stirred overnight at room temperature. A saturated aqueous solution of ammonium chloride was added to the mixture to quench the reaction. The product was purified by a conventional purification process to obtain fluorine-containing triphenylmethyl alcohol (Ab).

[0072] A methylene chloride solution of fluorine-containing trifluorophenylmethyl alcohol (Ab) was cooled to -78°C, and trifluoromethanesulfonic acid was added. The mixture was stirred for 15 minutes, and then trimethylsilyl azide was added. The mixture was allowed to warm to room temperature and then stirred overnight. The mixture was poured onto ice to quench the reaction, thereby obtaining fluorine-containing triphenylmethyl azide (Ac).

[0073] A methanol solution of fluorine-containing triphenylmethyl azide (Ac) was added to zinc and ammonium formate, and the mixture was stirred at room temperature for 17 hours. After removing zinc from the reaction solution, the product was purified by a conventional purification process to obtain a fluorine-containing triphenylmethylamine derivative.

[0074] (1-3) Synthesis of Fluorine-Containing Aromatic Amine Derivative (A6) A diethyl ether solution of 1-bromo-3,4,5-trifluorobenzene was cooled to −78°C, and a hexane solution of n-butyllithium (1.6 M) was added dropwise thereto. The mixture was stirred for 2 hours, and then benzophenone was further added dropwise thereto. The mixture was stirred overnight at room temperature. A saturated aqueous solution of ammonium chloride was added to the mixture to quench the reaction. The product was purified by a conventional purification process to obtain 3,4,5-trifluorophenyldiphenylmethyl alcohol.

[0075] A methylene chloride solution of 3,4,5-trifluorophenyldiphenylmethyl alcohol was cooled to -78°C, and trifluoromethanesulfonic acid was added. The mixture was stirred for 15 minutes, and then trimethylsilyl azide was added. The mixture was allowed to warm to room temperature and then stirred overnight. The mixture was poured onto ice to quench the reaction, yielding 3,4,5-trifluorophenyldiphenylmethyl azide.

[0076] A methanol solution of 3,4,5-trifluorophenyldiphenylmethyl azide was added to zinc and ammonium formate, and the mixture was stirred at room temperature for 17 hours. After removing zinc from the reaction solution, the product was purified by a conventional purification process to obtain 3,4,5-trifluorophenyldiphenylmethylamine (fluorine-containing aromatic amine derivative (A6)).

[0077] (2) Synthesis of disulfonic acid compound (B) Disulfonic acid compounds (B1) and (B2) were synthesized by the following procedure. Disulfonic acid compounds (B1) and (B2) are the same as those exemplified above, but are listed again below. B1: 9,10-bis(2-sulfoethenyl)anthracene B2: 1,8-disulfoanthracene

[0078] (2-1) Synthesis of 9,10-bis(2-sulfoethenyl)anthracene

[0079] 9,10-Dibromoanthracene (9.61 g, 28.6 mmol, 1.00 equivalents), palladium(II) acetate (0.154 g, 0.686 mmol, 0.0240 equivalents), and tri(o-tolyl)phosphine (0.351 g, 1.15 mmol, 0.0402 equivalents) were added to a 300 mL three-neck flask, and the atmosphere inside the flask was replaced with nitrogen. Next, dimethylformamide (30 mL, nitrogen-bubbled), triethylamine (10 mL, 71.7 mmol), and 2.3 M aqueous sodium vinylsulfonate solution (26.0 mL, 59.8 mmol, 2.02 equivalents) were added, and the mixture was refluxed at 120°C for 14 hours. The reaction mixture was then filtered, and the remaining residue was dissolved in water. The resulting dark suspension was centrifuged. The supernatant was decanted and centrifuged again, and this procedure was repeated until the supernatant became clear. The water was then distilled off, and the precipitated solid was washed with dichloromethane to obtain a dark yellow-green solid. The solid was dissolved in a 1:2 mixture of water and ethanol with heating, and after complete dissolution, it was recrystallized by ice cooling to obtain the sodium salt of 9,10-bis(2-sulfoethenyl)anthracene as bright yellow crystals (6.14 g, 14.1 mmol). The yield was 49%.

[0080] The sodium salt of 9,10-bis(2-sulfoethenyl)anthracene obtained by the above procedure was subjected to ion exchange to obtain 9,10-bis(2-sulfoethenyl)anthracene (B1). The ion exchange procedure is as follows. First, 120 mL of ion exchange resin was packed into a brown column, and a mixed solution of 12 M hydrochloric acid (30 mL) and water (400 mL) was passed through it for 1 hour to activate the ion exchange resin. After activation, an additional 500 mL of deionized water was passed through the column to remove residual HCl. Next, the sodium salt of 9,10-bis(2-sulfoethenyl)anthracene (up to 1 g) was dissolved in deionized water (700 mL per 1 g of salt) and passed through the ion exchange resin in the brown column for 2 to 3 hours. The distillation of the compound was confirmed using pH paper and a black light. After passing through the column, the distilled aqueous solution was distilled off to obtain solid 9,10-bis(2-sulfoethenyl)anthracene (B1).

[0081] (2-2) Synthesis of 1,8-disulfoanthracene (B2)

[0082] The zinc powder was activated by washing twice with 3% hydrochloric acid, once each with deionized water, ethanol, and ether, and then dried under vacuum. Dipotassium anthraquinone-1,8-disulfonate (5.0 g, 11 mmol) was added to 30% aqueous ammonium carbonate (175 mL), and then activated zinc powder (5.0 g, 76 mmol) was added. The mixture was stirred vigorously at 60°C for 3 hours, during which the solution turned orange and a yellow and gray precipitate formed. The precipitate was filtered, and concentrated sulfuric acid (40 mL) was added dropwise in an ice bath. A yellow precipitate formed and was collected by filtration. The yellow solid was washed with acetone and recrystallized from 1.1 M aqueous potassium chloride (200 mL) to give the potassium salt of 1,8-disulfoanthracene (3.3 g, 7.9 mmol) as thin brown platelets. The yield was 72%.

[0083] The potassium salt of 1,8-disulfoanthracene obtained by the above procedure was subjected to ion exchange to obtain 1,8-disulfoanthracene (B2). The ion exchange procedure was the same as that described for the synthesis of 9,10-bis(2-sulfoethenyl)anthracene (A1). The aqueous solution distilled from the brown column was distilled off to obtain solid 1,8-disulfoanthracene (B2).

[0084] (3) Synthesis of Organic Salts Organic salts were synthesized using the fluorine-containing aromatic amine derivative (A) and disulfonic acid compound (B) synthesized by the above procedure, and, if necessary, a template compound (C). The template compounds used in the following examples are as follows: C1: toluene, C2: benzonitrile, C3: dimethylformamide.

[0085] Example 1 A methanol solution of a fluorine-containing triphenylmethylamine derivative (A1) and a methanol solution of a disulfonic acid compound (B1) were prepared separately. The two solutions were mixed so that the equivalent ratio of the fluorine-containing triphenylmethylamine derivative (A1) to the disulfonic acid compound (B1) was 2:1. Methanol was evaporated from the resulting mixed solution, and the residue was washed with diethyl ether to obtain a powdered organic salt. This powdered organic salt was uniformly dissolved in methanol, heated to 40°C, and the solvent was gradually removed to obtain crystals of the organic salt. X-ray crystal structure analysis of the obtained crystals identified the P1- triclinic crystal structure shown in Figure 2. The organic salt of Example 1 contained the fluorine-containing triphenylmethylamine derivative (A1) and the disulfonic acid compound (B1) and was produced without using a template compound (C).

[0086] Example 2 A methanol solution of a fluorine-containing triphenylmethylamine derivative (A1) and a methanol solution of a disulfonic acid compound (B1) were prepared separately. The two solutions were mixed so that the equivalent ratio of the fluorine-containing triphenylmethylamine derivative (A1) to the disulfonic acid compound (B1) was 2:11. Methanol was evaporated from the resulting mixed solution, and the residue was washed with diethyl ether to obtain a powdered organic salt. This powdered organic salt was uniformly dissolved in methanol, and the template compound (C1) (toluene) was added to the solution. The solution was heated to 40°C to gradually remove the solvent, yielding a crystal of the organic salt. Using a supercritical fluid extraction system (manufactured by JASCO Corporation), the obtained crystals were contacted with supercritical carbon dioxide fluid to remove the template compound (C1) from the crystals. X-ray crystal structure analysis of the crystals after removal of the template compound (C1) identified the C2 / c monoclinic crystal structure shown in FIG. 3. The porosity of this crystal structure was 10.8%. The organic salt of Example 2 contains a fluorine-containing triphenylmethylamine derivative (A1) and a disulfonic acid compound (B1), and was produced using a template compound (C1) (toluene).

[0087] Example 3 A methanol solution of a fluorine-containing triphenylmethylamine derivative (A1) and a methanol solution of a disulfonic acid compound (B1) were prepared separately. The two solutions were mixed so that the equivalent ratio of the fluorine-containing triphenylmethylamine derivative (A1) to the disulfonic acid compound (B1) was 2:1. Methanol was evaporated from the resulting mixed solution, and the residue was washed with diethyl ether to obtain a powdered organic salt. This powdered organic salt was uniformly dissolved in methanol, and a template compound (C2) (benzonitrile) was added to the solution. The solution was heated to 40°C to gradually remove the solvent, yielding a crystal of the organic salt. Using a supercritical fluid extraction system (manufactured by JASCO Corporation), the obtained crystals were contacted with supercritical carbon dioxide fluid to remove the template compound (C2) from the crystals. X-ray crystal structure analysis of the crystals after removal of the template compound (C2) identified the I2 / a monoclinic crystal structure shown in FIG. 4. The porosity of this crystal structure was 50.0%. The organic salt of Example 3 contains a fluorine-containing triphenylmethylamine derivative (A1) and a disulfonic acid compound (B1), and was produced using a template compound (C2) (benzonitrile).

[0088] Example 4 A methanol solution of a fluorine-containing triphenylmethylamine derivative (A2) and a methanol solution of a disulfonic acid compound (B1) were prepared separately. The two solutions were mixed so that the equivalent ratio of the fluorine-containing triphenylmethylamine derivative (A2) to the disulfonic acid compound (B1) was 2:1. Methanol was evaporated from the resulting mixed solution, and the residue was washed with diethyl ether to obtain a powdered organic salt. This powdered organic salt was uniformly dissolved in a template compound (C3) (dimethylformamide), to which 1,2,4-trichlorobenzene was further added. The solution was heated to 40°C to gradually remove the solvent, yielding crystals of the organic salt. Using a supercritical fluid extraction system (manufactured by JASCO Corporation), the obtained crystals were contacted with supercritical carbon dioxide fluid to remove the template compound (C3) from the crystals. X-ray crystal structure analysis of the crystals after removal of the template compound (C3) identified the P1-triclinic crystal structure shown in FIG. 5. The porosity of this crystal structure was 15.9%. The organic salt of Example 4 contained a fluorine-containing triphenylmethylamine derivative (A2) and a disulfonic acid compound (B1), and was produced using a template compound (C3) (dimethylformamide).

[0089] Example 5 A methanol solution of a fluorine-containing triphenylmethylamine derivative (A2) and a methanol solution of a disulfonic acid compound (B1) were prepared separately. The two solutions were mixed so that the equivalent ratio of the fluorine-containing triphenylmethylamine derivative (A2) to the disulfonic acid compound (B1) was 2:1. Methanol was evaporated from the resulting mixed solution, and the residue was washed with diethyl ether to obtain a powdered organic salt. This powdered organic salt was uniformly dissolved in methanol, to which a template compound (C2) (benzonitrile) was added. The solution was heated to 40°C to gradually remove the solvent, obtaining crystals of the organic salt. Using a supercritical fluid extraction system (manufactured by JASCO Corporation), the obtained crystals were contacted with supercritical carbon dioxide fluid to remove the template compound (C2) from the crystals. X-ray crystal structure analysis was performed on the crystals after removing the template compound (C2). I4 shown in FIG. 6 was obtained. １A 22-tetragonal crystal structure was identified. The porosity of this crystal structure was 41.6%. The organic salt of Example 5 contains a fluorine-containing triphenylmethylamine derivative (A2) and a disulfonic acid compound (B1), and was produced using a template compound (C2) (benzonitrile).

[0090] Example 6 A methanol solution of a fluorine-containing triphenylmethylamine derivative (A1) and a methanol solution of a disulfonic acid compound (B2) were prepared separately. The two solutions were mixed so that the equivalent ratio of the fluorine-containing triphenylmethylamine derivative (A1) to the disulfonic acid compound (B2) was 2:1. After adding a template compound (C2) (benzonitrile), the mixed solution was maintained at 3°C ​​to volatilize the methanol, yielding crystals of an organic salt. Using a supercritical fluid extraction system (manufactured by JASCO Corporation), the obtained crystals were contacted with supercritical carbon dioxide fluid to remove the template compound (C2) from the crystals. X-ray crystal structure analysis of the crystals after removal of the template compound (C2) identified a triclinic crystal structure. The porosity of this crystal structure was 6.7%. The organic salt of Example 6 contained a fluorine-containing triphenylmethylamine derivative (A1) and a disulfonic acid compound (B2) and was produced using the template compound (C2) (benzonitrile).

[0091] Example 7 A methanol solution of a fluorine-containing triphenylmethylamine derivative (A2) and a methanol solution of a disulfonic acid compound (B2) were prepared separately. The two solutions were mixed so that the equivalent ratio of the fluorine-containing triphenylmethylamine derivative (A2) to the disulfonic acid compound (B2) was 2:1. After adding the template compound (C2) (benzonitrile), the mixed solution was kept at 3°C ​​to volatilize the methanol, yielding crystals of an organic salt. Using a supercritical fluid extraction system (manufactured by JASCO Corporation), the obtained crystals were contacted with supercritical carbon dioxide fluid to remove the template compound (C2) from the crystals. X-ray crystal structure analysis of the crystals after removing the template compound (C2) identified a triclinic crystal structure. The porosity of this crystal structure was 27.6%. The organic salt of Example 7 contains a fluorine-containing triphenylmethylamine derivative (A2) and a disulfonic acid compound (B2), and was produced using a template compound (C2) (benzonitrile).

[0092] Example 8 A methanol solution of a fluorine-containing triphenylmethylamine derivative (A3) and a methanol solution of a disulfonic acid compound (B2) were prepared separately. The two solutions were mixed so that the equivalent ratio of the fluorine-containing triphenylmethylamine derivative (A3) to the disulfonic acid compound (B2) was 2:1. After adding the template compound (C2) (benzonitrile), the mixed solution was kept at 3°C ​​to volatilize the methanol, yielding crystals of an organic salt. Using a supercritical fluid extraction system (manufactured by JASCO Corporation), the obtained crystals were contacted with supercritical carbon dioxide fluid to remove the template compound (C2) from the crystals. X-ray crystal structure analysis of the crystals after removing the template compound (C2) identified a triclinic crystal structure. The porosity of this crystal structure was 13.9%. The organic salt of Example 8 contains a fluorine-containing triphenylmethylamine derivative (A3) and a disulfonic acid compound (B2), and was produced using a template compound (C2) (benzonitrile).

[0093] Example 9 A methanol solution of a fluorine-containing aromatic amine derivative (A6) and a methanol solution of a disulfonic acid compound (B1) were prepared separately. The two solutions were mixed so that the equivalent ratio of the fluorine-containing aromatic amine derivative (A6) to the disulfonic acid compound (B1) was 2:1. Methanol was evaporated from the resulting mixed solution, and the residue was washed with diethyl ether to obtain a powdered organic salt. This powdered organic salt was uniformly dissolved in methanol, heated to 40°C, and the solvent was gradually removed to obtain crystals of the organic salt. The organic salt of Example 9 contained the fluorine-containing aromatic amine derivative (A6) and the disulfonic acid compound (B1), and was produced without using a template compound (C).

[0094] (4) Inclusion of guest molecules Using the organic salts synthesized by the above procedure, we attempted to inclusion of guest compounds and to detect their inclusion.

[0095] (Test using the crystals of the organic salt of Example 3) (Example 3A) The crystals of the organic salt of Example 3 and perfluoroheptanoic acid (C ６ F １３ COOH) (an example of a perfluoroalkyl compound) were placed in a semi-sealed container in a manner that prevented visible contact and were maintained at 23°C for 19 hours. The organic salt crystals were removed from the semi-sealed container, and their fluorescence spectra were measured by fluorescence spectroscopy using a spectrofluorometer (FP-8500 manufactured by JASCO Corporation) with an excitation wavelength of 365 nm.

[0096] Comparative Example 3A: Perfluoroheptanoic acid was replaced with heptanoic acid (C ６ H １３ The test was carried out in the same manner as in Example 3A, except that the hydroxypropyl methylcellulose was changed to hydroxypropyl methylcellulose (COOH).

[0097] (Comparative Example 3B) The fluorescence spectrum of the organic salt crystals of Example 3 was measured by fluorescence spectroscopy at an excitation wavelength of 365 nm using a spectrofluorometer (FP-8500 manufactured by JASCO Corporation). The fluorescence spectrum of Comparative Example 3B is the fluorescence spectrum exhibited by the organic salt in a state in which no guest compound is included.

[0098] (Test using crystals of organic salt of Example 6) (Example 6A) A test was carried out in the same manner as in Example 3A, except that the crystals of organic salt of Example 3 were changed to the crystals of organic salt of Example 6.

[0099] Comparative Example 6A: Perfluoroheptanoic acid was replaced with heptanoic acid (C ６ H １３ The test was carried out in the same manner as in Example 6A, except that the hydroxypropyl methylcellulose was changed to hydroxypropyl methylcellulose (COOH).

[0100] Comparative Example 6B The organic salt crystals of Example 6 were tested in the same manner as in Comparative Example 3B.

[0101] (Test using crystals of organic salt of Example 7) (Example 7A) A test was carried out in the same manner as in Example 3A, except that the crystals of organic salt of Example 3 were changed to the crystals of organic salt of Example 7.

[0102] Comparative Example 7A: Perfluoroheptanoic acid was replaced with heptanoic acid (C ６ H １３ The test was carried out in the same manner as in Example 7A, except that the hydroxypropyl methylcellulose was changed to hydroxypropyl methylcellulose (COOH).

[0103] Comparative Example 7B The organic salt crystals of Example 7 were tested in the same manner as in Comparative Example 3B.

[0104] (Test using crystals of organic salt of Example 8) (Example 8A) A test was carried out in the same manner as in Example 3A, except that the crystals of organic salt of Example 3 were changed to the crystals of organic salt of Example 8.

[0105] Comparative Example 8A: Perfluoroheptanoic acid was replaced with heptanoic acid (C ６ H １３ The test was carried out in the same manner as in Example 18A, except that the hydroxypropyl methylcellulose was changed to hydroxypropyl methylcellulose (COOH).

[0106] Comparative Example 8B The organic salt crystals of Example 8 were tested in the same manner as in Comparative Example 3B.

[0107] (Test using crystals of organic salt of Example 9) (Example 9A) A test was carried out in the same manner as in Example 3A, except that the crystals of organic salt of Example 3 were changed to the crystals of organic salt of Example 9.

[0108] Comparative Example 9B The organic salt crystals of Example 9 were tested in the same manner as in Comparative Example 3B.

[0109] (Results) The fluorescence spectra in the tests using the crystals of the organic salts of Examples 3 and 6 to 9 are shown in Figures 7 to 11, respectively.

[0110] 7, the peak wavelength of Example 3A was 530 nm. This was significantly longer than the peak wavelength of 470 nm of Comparative Example 3B. On the other hand, the peak wavelength of Comparative Example 3A was 470 nm, and no significant difference was observed between Comparative Example 3A and Comparative Example 3B.

[0111] 8, the peak wavelength of Example 6A was 460 nm. This was significantly shifted to shorter wavelengths compared to the peak wavelength of 520 nm of Comparative Example 6B. On the other hand, the peak wavelength of Comparative Example 6A was 520 nm, and no significant difference was observed between Comparative Example 6A and Comparative Example 6B.

[0112] 9, Example 7A gave a spectrum with two peaks, at 470 nm and 530 nm. A significant change was observed compared to the spectrum of Comparative Example 7B, which had only a peak at 460 nm. On the other hand, Comparative Example 7A gave a spectrum with only a peak at 470 nm, and the appearance of a new peak like that of Example 7A was not observed.

[0113] 10, the peak wavelength of Example 8A was 450 nm. This was significantly shifted to shorter wavelengths compared to the peak wavelength of 540 nm of Comparative Example 8B. On the other hand, the peak wavelength of Comparative Example 8A was 540 nm, and no significant difference was observed between Comparative Example 8A and Comparative Example 8B.

[0114] 11, the peak wavelength of Example 9A was 480 nm, which can be said to have been significantly shifted to shorter wavelengths compared to the peak wavelength of 490 nm of Comparative Example 9B.

[0115] As described above, perfluoroheptanoic acid can be detected based on the change in the fluorescence spectrum when it comes into contact with perfluoroheptanoic acid. As is clear from the above experimental procedure, perfluoroheptanoic acid is included in the organic salt crystals without any visible contact. This is thought to be because perfluoroheptanoic acid vaporized by evaporation or sublimation is included in the organic salt.

[0116] In the above examples, perfluoroheptanoic acid was used as a specific example of a perfluoroalkyl compound, and it was confirmed that the organic salt could include the perfluoroalkyl compound. However, the perfluoroalkyl compound that can be included in the organic salt according to this embodiment is not limited to perfluoroheptanoic acid.

[0117] [Other Embodiments] In the above embodiment, as a synthesis example of the fluorine-containing aromatic amine derivative (A), １ , Ar ２ , and Ar ３ are all substituted aromatic groups containing a fluorine atom (fluorine-containing triphenylamine derivatives (A1) to (A5)), and １ , Ar ２ , and Ar ３ Among them, Ar １ A specific example is given for the case where only Ar is a substituted aromatic group containing a fluorine atom (fluorine-containing aromatic amine derivative (A6)). １ , Ar ２ , and Ar ３ Among them, Ar １ and Ar ２ is a substituted aromatic group containing a fluorine atom, and Ar ３ When is an aromatic group not containing fluorine, the fluorine-containing aromatic amine derivative (A) can be synthesized by the following generalized method.

[0118] First, a diethyl ether solution of a brominated fluorine-containing substituted aromatic compound is cooled, and a hexane solution of n-butyllithium is added dropwise to the cooled solution. After stirring the mixture for a predetermined time, methyl benzoate is further added dropwise. After stirring the mixture at room temperature, a saturated aqueous solution of ammonium chloride is added to the mixture to quench the reaction. The product is purified by a conventional purification process, and HO-CAR １ Ar ２ Ar ３ Thereafter, an amine derivative can be obtained via an azide compound in the same manner as in the cases of the fluorine-containing triphenylmethylamine derivatives (A2) to (A5) and the fluorine-containing aromatic amine derivative (A6).

[0119] Regarding other configurations, it should be understood that the embodiments disclosed in this specification are illustrative in all respects and that the scope of the present invention is not limited thereby. Those skilled in the art will easily understand that appropriate modifications are possible without departing from the spirit of the present invention. Therefore, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention.

[0120] The present invention can be used to detect perfluoroalkyl compounds.

[0121] 1: Detector 2: Organic salt unit 21: Sample chamber 22: Organic salt 23: Specimen 3: Irradiator 4: Detector 5: Control device

Claims

1. An organic salt comprising a fluorine-containing aromatic amine derivative (A) represented by formula (1) and a disulfonic acid compound (B) represented by formula (2), In formula (1), Ar １ is a substituted aromatic group containing at least one fluorine atom, Ar ２ and Ar ３ is a substituted or unsubstituted aromatic group, and in formula (2), X is a polycyclic aromatic hydrocarbon group, and Y １ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group, and Y ２ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group.

2. The fluorine-containing aromatic amine derivative (A) is a fluorine-containing triphenylamine derivative represented by formula (1a): In formula (1a), R １ , R ２ , and R ３ 2. The organic salt according to claim 1, wherein at least one of the groups is a fluorine-containing group containing at least one fluorine atom.

3. Ar １ 2. The organic salt according to claim 1, wherein is a substituted aromatic group in which at least one hydrogen atom is substituted with a fluorine atom or a fluoroalkyl group.

4. The organic salt according to claim 1, wherein in formula (2), X is a polycyclic aromatic hydrocarbon group having 2 to 5 aromatic rings.

5. The organic salt according to claim 4, wherein the disulfonic acid compound (B) is 1,8-disulfoanthracene.

6. The organic salt according to any one of claims 1 to 5, which is a crystal obtained by removing at least a portion of template compound (C) from a crystal containing the fluorine-containing aromatic amine derivative (A), the disulfonic acid compound (B), and at least one template compound (C) selected from the group consisting of benzene, chlorobenzene, toluene, chlorotoluene, dichlorobenzene, trichlorobenzene, anisole, methyl benzoate, xylene, mesitylene, nitrobenzene, benzonitrile, tetrahydrofuran, dioxane, methanol, dimethylformamide, and dimethyl sulfoxide.

7. A device for detecting a perfluoroalkyl compound, comprising: an organic salt unit containing an organic salt capable of encapsulating a perfluoroalkyl compound; an irradiator for irradiating the organic salt with ultraviolet light; and a detector for detecting fluorescence emitted from the organic salt irradiated with ultraviolet light by the irradiator, wherein the organic salt contains a fluorine-containing aromatic amine derivative (A) represented by formula (1) and a disulfonic acid compound (B) represented by formula (2), In formula (1), Ar １ is a substituted aromatic group containing at least one fluorine atom, Ar ２ and Ar ３ is a substituted or unsubstituted aromatic group, and in formula (2), X is a polycyclic aromatic hydrocarbon group, and Y １ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group, and Y ２ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group.

8. A method for detecting a perfluoroalkyl compound, comprising the steps of: bringing an organic salt into contact with a test specimen; irradiating the organic salt that has been brought into contact with the test specimen with ultraviolet light and detecting fluorescence emitted by the organic salt; and determining the presence or absence of a perfluoroalkyl compound in the test specimen based on the wavelength of the fluorescence, wherein the organic salt comprises a fluorine-containing aromatic amine derivative (A) represented by formula (1) and a disulfonic acid compound (B) represented by formula (2), In formula (1), Ar １ is a substituted aromatic group containing at least one fluorine atom, Ar ２ and Ar ３ is a substituted or unsubstituted aromatic group, and in formula (2), X is a polycyclic aromatic hydrocarbon group, and Y １ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group, and Y ２ is a group selected from the group consisting of a single bond, an alkylene group, an alkenyl group, an alkynyl group, and a phenylene group.

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