Unsaturated hydrocarbon scavengers, novel compounds, and metal-organic structures

Abstract

To provide an unsaturated hydrocarbon scavenger capable of scavenging an unsaturated hydrocarbon having at least one carbon-carbon double bond, with high selectivity.SOLUTION: An unsaturated hydrocarbon scavenger according to one aspect of the present disclosure has at least one carbon-carbon double bond, and contains a metal-organic framework that has a metal and a ligand coordinated to the metal, wherein the ligand includes a compound having a nitrogen-containing aromatic heterocycle.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to unsaturated hydrocarbon scavengers, novel compounds, and metal-organic frameworks. Background Art

[0002] Dienes such as isoprene and 1,3-butadiene are useful compounds as starting materials for synthetic rubber production and as intermediates for a very large number of compounds. Dienes are obtained by separation from fractions such as those from naphtha cracking units. Examples of C5 fractions include isoprene, 2-methyl-1-butene, 2-methyl-2-butene, 1-pentene, isopentane, and n-pentane. Examples of C4 fractions include 1,3-butadiene, isobutene, 1-butene, 2-butene, n-butane, and isobutane. Since the boiling points of the components in each fraction are close to each other, it is difficult to separate isoprene or 1,3-butadiene by distillation. Currently, extractive distillation is used for separating isoprene from C5 fractions and 1,3-butadiene from C4 fractions, but this method has the problem that large amounts of energy are consumed for regenerating the extraction solvent. For this reason, PSA / TSA methods (adsorptive separation methods), which can separate and recover dienes with lower energy consumption, have attracted attention.

[0003] For example, Non-Patent Document 1 discloses that using MIL-125 and NH₂-MIL-125 as metal-organic frameworks enables selective capture of isoprene from a mixture of 2-methylbutane and isoprene. Prior Art Documents Non-Patent Documents

[0004] Non-Patent Document 1 Kim, S., Ahn, W., catalysis today, 2013, 204, 85-93. Summary of the Invention Problems to be Solved by the Invention

[0005] However, the metal-organic framework disclosed in Non-Patent Document 1 still has room for improvement in terms of isoprene selectivity.

[0006] The present disclosure provides an unsaturated hydrocarbon scavenger capable of capturing unsaturated hydrocarbons having at least one carbon-carbon double bond with high selectivity. The present disclosure also provides a novel metal-organic framework and a novel compound useful as such an unsaturated hydrocarbon scavenger. [Means for Solving the Problem]

[0007] One aspect of the present disclosure relates to an unsaturated hydrocarbon scavenger for an unsaturated hydrocarbon having at least one carbon-carbon double bond, the unsaturated hydrocarbon scavenger containing a metal-organic framework having a metal and a ligand coordinated to the metal, and the ligand comprising a compound having a nitrogen-containing aromatic heterocycle.

[0008] In one embodiment, the unsaturated hydrocarbon may contain a chain diolefin having 4 to 5 carbon atoms. In one embodiment, the unsaturated hydrocarbon may contain a chain monoolefin having 4 to 5 carbon atoms. In one embodiment, the metal may comprise a metal of Groups 2 to 14 of the periodic table.

[0009] In one embodiment, the compound having a nitrogen-containing aromatic heterocycle may include a compound represented by the following general formula (1). [Chemical Formula] [In the formula, Ar 1 to Ar 4 each independently represent a monovalent nitrogen-containing aromatic heterocyclic group, and X 1 to X 4 each independently represent an integer of 1 to 3.]

[0010] In one embodiment, the compound having a nitrogen-containing aromatic heterocycle may include at least one compound selected from the group consisting of compounds represented by the following general formulas (1-1) to (1-3). [Chemical Formula] [In the formula, X 1 to X 4 each independently represent an integer of 1 to 3.] [Chemical Formula] [In the formula, X 1 to X 4 each independently represent an integer of 1 to 3.] [Chemical Formula] [In the formula, X 1 to X 4 each independently represent an integer of 1 to 3.]

[0011] In one aspect, the ligand may further comprise a halogen.

[0012] In one aspect, the metal contains Cu, the ligand further contains I, the compound having a nitrogen-containing aromatic heterocycle comprises a compound represented by general formula (1-1), and when the compound represented by general formula (1-1) is defined as L 1 , the composition formula of the metal-organic framework may be represented by Cu₂I₂L 1 .

[0013] In one aspect, the metal contains Cu, the ligand further contains I, the compound having a nitrogen-containing aromatic heterocycle comprises a compound represented by general formula (1-2), and when the compound represented by general formula (1-2) is defined as L 2 , the composition formula of the metal-organic framework may be represented by Cu₂I₂L 2 .

[0014] In one aspect, the metal contains Ni, the compound having a nitrogen-containing aromatic heterocycle comprises a compound represented by general formula (1-3), and when the compound represented by general formula (1-3) is defined as L 3 , the composition formula of the metal-organic framework may be represented by Ni₂L 3 .

[0015] In one embodiment, the metal includes Cu, and the compound having a nitrogen-containing aromatic heterocycle includes a compound represented by general formula (1-3), and the compound represented by general formula (1-3) is L 3 Therefore, the compositional formula of the metal-organic structure is Cu2L 3 It can be expressed as follows.

[0016] Another aspect of this disclosure relates to compounds represented by the following general formulas (1-3). [ka] [where, X 1 ~X 4 Each of these independently represents an integer between 1 and 3.

[0017] Another aspect of this disclosure relates to a metal-organic structure comprising a metal and a ligand coordinating to the metal, wherein the metal comprises a metal consisting of a first transition series element, and the ligand comprises a compound relating to the other aspect described above. [Effects of the Invention]

[0018] This disclosure provides an unsaturated hydrocarbon scavenger capable of capturing unsaturated hydrocarbons having at least one carbon-carbon double bond with high selectivity. Furthermore, this disclosure provides novel metal-organic structures and novel compounds useful as such unsaturated hydrocarbon scavengers. [Brief explanation of the drawing]

[0019] [Figure 1] Figure 1(a) shows the gas adsorption / desorption isotherm measured using the metal-organic structure of Example 1. Figure 1(b) shows the gas adsorption / desorption isotherm measured using the metal-organic structure of Example 2. [Figure 2] Figure 2(a) shows the gas adsorption / desorption isotherm measured using the metal-organic structure of Example 3. Figure 2(b) shows the gas adsorption / desorption isotherm measured using the metal-organic structure of Example 4. [Figure 3]Figure 3(a) shows the peak chart obtained by powder X-ray diffraction for the metal-organic structure of Example 3 and the peak chart obtained by simulation of powder X-ray diffraction for the metal-organic structure [Ni2L13]. Figure 3(b) shows the peak chart obtained by powder X-ray diffraction for the metal-organic structure of Example 4 and the peak chart obtained by simulation of powder X-ray diffraction for the metal-organic structure [Cu2L13]. [Modes for carrying out the invention]

[0020] Preferred embodiments of this disclosure are described in detail below.

[0021] [Unsaturated hydrocarbon scavengers] The unsaturated hydrocarbon scavenger according to this embodiment contains a metal-organic structure having a metal and a ligand coordinated to the metal, wherein the ligand includes a compound having a nitrogen-containing aromatic heterocycle. According to the unsaturated hydrocarbon scavenger according to this embodiment, unsaturated hydrocarbons can be captured with high selectivity.

[0022] The unsaturated hydrocarbons captured by the unsaturated hydrocarbon scavenger according to this embodiment have at least one carbon-carbon double bond. The number of carbon atoms in such unsaturated hydrocarbons is preferably 4 and 5, as this tends to allow for more selective capture. The unsaturated hydrocarbons may be in chain form. Examples of such unsaturated hydrocarbons include monoolefins and diolefins (dienes). Examples of monoolefins include 1-pentene, trans-2-pentene, cis-2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 1-butene, trans-2-butene, cis-2-butene, and isobutene. Examples of dienes include isoprene, trans-piperylene, cis-piperylene, and 1,3-butadiene, with isoprene being preferred as it tends to allow for more selective capture. Note that the "unsaturated hydrocarbon having at least one carbon-carbon double bond" in this disclosure does not include aromatic compounds.

[0023] The content of the metal-organic structure may be 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass, based on the total amount of the unsaturated hydrocarbon scavenger.

[0024] <Metal organic structure> The following provides a detailed description of metal-organic structures.

[0025] Metal-organic frameworks (MOFs) are also known as porous coordination polymers (PCPs) or porous coordination networks (PCNs).

[0026] Metallic-organic structures have a framework. The framework is constructed by ligands bonding to nodal metals via coordinate bonds, and consists of constituent elements and chemical bonds (mainly covalent and coordinate bonds).

[0027] Metal-organic structures are capable of capturing and desorbing unsaturated hydrocarbons. Within the metal-organic structure, pores are formed by the three-dimensional structure of the metal-organic structure. These pores are spaces in which unsaturated hydrocarbons can be contained.

[0028] When the raw materials for adsorption and desorption include isoprene and 2-methylbutane, and the molar ratio of isoprene to 2-methylbutane in the raw materials (isoprene:2-methylbutane) is 1:1, the amount of isoprene adsorbed by the metal-organic structure may be 1.8 mol or more, 2.2 mol or more, 9.0 mol or more, or 300 mol or more per 1 mol of 2-methylbutane at 50 kPa and 25°C.

[0029] When the raw materials for adsorption and desorption contain 2-methyl-1-butene and 2-methylbutane, and the molar ratio of 2-methyl-1-butene to 2-methylbutane in the raw materials (2-methyl-1-butene:2-methylbutane) is 1:1, the amount of 2-methyl-1-butene adsorbed by the metal-organic structure may be 1.4 mol or more, 1.6 mol or more, 5.0 mol or more, or 80 mol or more per mol of 2-methylbutane at 50 kPa and 25°C.

[0030] When the raw materials for adsorption and desorption contain isoprene and 2-methyl-1-butene, and the molar ratio of isoprene to 2-methyl-1-butene in the raw materials (isoprene:2-methyl-1-butene) is 1:1, the amount of isoprene adsorbed by the metal-organic structure may be 1.2 mol or more, 1.4 mol or more, 1.5 mol or more, or 3.5 mol or more per mol of 2-methyl-1-butene at 50 kPa and 25°C.

[0031] The ratio of adsorption amounts in various raw materials can be calculated by measuring the gas adsorption / desorption isotherms for each component contained in the raw material, and then using the Ideal Adsorbed Solution Theory (IAST) method, following the method described in Lee, S.; Lee, JH; Kim, J. Korean J. Chem. Eng. 2018, 35, 214-221.

[0032] When the raw materials for adsorption and desorption include isoprene and 2-methylbutane, and the molar ratio of isoprene to 2-methylbutane in the raw materials (isoprene:2-methylbutane) is 1:1, it is preferable that the amount of isoprene adsorbed by the metal-organic structure is 8 mmol / g or more at 50 kPa and 25°C.

[0033] Since metals tend to capture unsaturated hydrocarbons with higher selectivity, they are preferably metals from groups 2 to 14 of the periodic table, preferably metals composed of first transition series elements, and more preferably Cu and Ni. Examples of metals from groups 2 to 14 of the periodic table include Zr, Cd, Ti, Cu, Zn, Fe, Cr, Ni, Co, Mo, Hf, Mg, Al, Si, Cu, Zr, Zn, and Cd. Examples of metals composed of first transition series elements include Cr, Mn, Fe, Co, Ni, and Cu.

[0034] The ligand includes a compound having a nitrogen-containing aromatic heterocycle. The nitrogen-containing aromatic heterocycle is, for example, coordinated to the metal by the nitrogen atom contained in the nitrogen-containing aromatic heterocycle. Since the nitrogen-containing aromatic heterocycle tends to capture unsaturated hydrocarbons with higher selectivity, it is preferable that the compound is represented by the following general formula (1), and more preferably that it is at least one compound selected from the group consisting of compounds represented by the following general formulas (1-1) to (1-3). [ka] [In the formula, Ar 1 ~Ar 4 Each of these independently represents a monovalent nitrogen-containing aromatic heterocyclic group, X 1 ~X 4 Each of these independently represents an integer between 1 and 3. [ka] [where, X 1 ~X 4 Each of these independently represents an integer between 1 and 3. [ka] [where, X 1 ~X 4 Each of these independently represents an integer between 1 and 3. [ka] [where, X 1 ~X 4 Each of these independently represents an integer between 1 and 3.

[0035] In formula (1), Ar 1 ~Ar 4 Examples of such groups include pyridine, pyrazole, triazole, and tetraazole groups. Pyridine and pyrazole groups are preferred because they tend to capture unsaturated hydrocarbons with even higher selectivity.

[0036] In equations (1), (1-1), (1-2), and (1-3), X 1 ~X 4 It is preferable that the ratio is 1, as this tends to capture unsaturated hydrocarbons with even higher selectivity.

[0037] The compound represented by the above general formula (1-1) tends to capture unsaturated hydrocarbons with even higher selectivity, therefore, the compound represented by the following formula (1-1a) (3-TPPM: Tetra-4-(3-pyridyl)phenyl methane) is preferable. [ka]

[0038] The compound represented by the above general formula (1-2) tends to capture unsaturated hydrocarbons with even higher selectivity, therefore, the compound represented by the following formula (1-2a) (4-TPPM: Tetra-4-(4-pyridyl)phenyl methane) is preferred. [ka]

[0039] The compounds represented by the above general formula (1-3) tend to capture unsaturated hydrocarbons with even higher selectivity, and therefore, the compound represented by the following formula (1-3a) (pyrazolate TPM: Tetrakis-4-(4-1H-pyrazolyl)phenyl methane) is preferred. [ka]

[0040] The ligand may further contain a halogen. Examples of halogens include F, Cl, Br, and I, with I being preferred because it tends to capture unsaturated hydrocarbons with even higher selectivity.

[0041] The compositional formula of metal-organic structures is preferably represented as [M2I2L] or [M2L], as they tend to capture unsaturated hydrocarbons with higher selectivity. 1 ], [Cu2I2L 2 ], [Ni2L 3 ] or [Cu2L 3 It is more preferable that it be represented as ]. Here, M represents a metal, L represents a compound having a nitrogen-containing aromatic heterocycle, and L 1 L represents the compound represented by the above general formula (1-1), 2 L represents a compound represented by the above general formula (1-2), 3 This represents a compound represented by the general formula (1-3) above.

[0042] The method for producing the compound represented by the above general formula (1-1) is not particularly limited, and for example, a method of production according to the synthesis reaction in the scheme below can be cited. [ka] [In formula (1A), Y 1 ~Y 4 X is a halogen atom, 1 ~X 4 Each of these independently represents an integer between 1 and 3.

[0043] The synthesis reaction in the above scheme is the so-called Suzuki-Miyaura coupling reaction. Examples of palladium catalysts used in the reaction include [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride (PdCl2(dppf)), tetrakis(triphenylphosphine)palladium (Pd(PPh3)4), bis(triphenylphosphine)dichloropalladium (Pd(PPh3)2Cl2), bis(benzylideneacetone)palladium (Pd(dba)2), tris(benzylideneacetone)dipalladium (Pd2(dba)3), bis(tritert-butylphosphine)palladium (Pd(Pt-Bu3)2), palladium acetate (Pd(OAc)2), and chloro[(tri-tert-butylphosphine)-2-(2-aminobiphenyl)]palladium(II) ((tBu3P)Pd G2). These catalysts may be used with known appropriate ligands. The amount of catalyst used may be, for example, 20 mol% or less, or 10 mol% or less, relative to the compound represented by formula (1B) above. Furthermore, if a ligand is used, its amount may be, for example, 20 mol% or less, or 10 mol% or less, relative to the compound represented by formula (1B) above.

[0044] A base may be used in the reaction to obtain the compound represented by the above general formula (1-1). Examples of bases include hydroxides, alkoxides, fluoride salts, carbonates, phosphates, and fluoride salts. Examples of hydroxides include sodium hydroxide, potassium hydroxide, and cesium hydroxide. Examples of alkoxides include tert-butoxysodium and tert-butoxypotassium. Examples of fluoride salts include lithium fluoride, potassium fluoride, and cesium fluoride. Examples of carbonates include lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, and potassium bicarbonate. Examples of phosphates include potassium phosphate. Examples of amines include trimethylamine, triethylamine, diisopropylamine, n-butylamine, and diisopropylethylamine. Of these, from the viewpoint of efficiently obtaining the target product, the base is preferably a carbonate or a phosphate, and more preferably potassium carbonate or cesium carbonate. The amount of base used is preferably 1 to 20 mol, and more preferably 2 to 10 mol, per 1 mol of formula (1B).

[0045] The solvent used in the reaction to obtain the compound represented by the above general formula (1-1) is not particularly limited as long as it does not adversely affect the reaction, but examples include aliphatic hydrocarbons, halogenated aliphatic hydrocarbons, aromatic hydrocarbons, ethers, amides, lactams, lactones, alcohols, urea derivatives, sulfoxides, and water. Examples of aliphatic hydrocarbons include pentane, n-hexane, n-octane, n-decane, and decalin. Examples of halogenated aliphatic hydrocarbons include chloroform, dichloromethane, dichloroethane, and carbon tetrachloride. Examples of aromatic hydrocarbons include benzene, nitrobenzene, toluene, o-xylene, m-xylene, p-xylene, and mesitylene. Examples of ethers include diethyl ether, diisopropyl ether, tert-butyl methyl ether, tetrahydrofuran (THF), dioxane, 1,2-dimethoxyethane, and 1,2-diethoxyethane. Examples of amides include N,N-dimethylformamide (DMF) and N,N-dimethylacetamide. Examples of lactams include N-methylpyrrolidone. Examples of lactones include γ-butyrolactone. Examples of alcohols include methanol, ethanol, and propanol. Examples of urea derivatives include N,N-dimethylimidazolidinone and tetramethylurea. Examples of sulfoxides include dimethyl sulfoxide, sulfolane, etc., and nitriles (acetonitrile, propionitrile, and butyronitrile). These may be used individually or in combination of two or more.

[0046] The amount of compound represented by formula (1B) above is preferably 4 to 10 moles, and more preferably 4.2 to 10 moles, per 1 mole of the compound represented by formula (1A), in order to ensure that the coupling reaction proceeds efficiently.

[0047] The reaction temperature for obtaining the compound represented by the general formula (1-1) above is appropriately set within the range from the melting point to the boiling point of the solvent, taking into consideration the type and amount of starting compounds and catalyst used, but is usually around 0 to 200°C, preferably 20 to 100°C. The reaction time cannot be specified in general as it varies depending on the starting compounds used, the reaction temperature, etc., but is usually around 1 to 72 hours.

[0048] The reaction to obtain the compound represented by the above general formula (1-1) is preferably carried out with nitrogen flowing through the reaction vessel.

[0049] The method for producing the compound represented by the above general formula (1-2) is not particularly limited, and for example, a method of production according to the synthesis reaction in the scheme below can be cited. [ka]

[0050] The synthesis reaction in the above scheme can be carried out in the same manner as the reaction to obtain the compound represented by the general formula (1-1), except that the compound represented by formula (1C) is used instead of the compound represented by formula (1B).

[0051] The method for producing the compounds represented by the above general formula (1-3) is not particularly limited, and for example, a method of production according to the synthesis reaction in the scheme below can be cited. [ka] [In formula (1E), X 1 ~X 4 Each of these independently represents an integer between 1 and 3.

[0052] In the step of obtaining the compound represented by the above general formula (1E), a so-called Suzuki-Miyaura coupling reaction is carried out. The palladium catalyst, ligand, base, and solvent used in the reaction can be the same as those used in the synthesis of the compound represented by the above general formula (1-1). The amount of catalyst used may be, for example, 20 mol% or less, or 10 mol% or less, relative to the compound represented by formula (1D). The amount of ligand used may be, for example, 20 mol% or less, or 10 mol% or less, relative to the compound represented by formula (1D). The amount of base used is preferably 1 to 20 mol, and more preferably 2 to 10 mol, per 1 mol of formula (1D).

[0053] The amount of compound represented by formula (1D) above is preferably 4 to 10 moles, and more preferably 4.2 to 10 moles, per 1 mole of the compound represented by formula (1A), in order to ensure that the coupling reaction proceeds efficiently. The reaction temperature and reaction time may be the same as those for the synthesis of the compound represented by general formula (1-1) above. The reaction is preferably carried out with nitrogen flowing through the reaction vessel.

[0054] Examples of acids used in the process of obtaining the compound represented by the above general formula (1-3) include hydrochloric acid. Examples of solvents used in the process of obtaining the compound represented by the above general formula (1-3) include ethanol. The reaction temperature in this step may be, for example, 85 to 90°C. When ethanol is used as the solvent, the reaction temperature in this step is not particularly limited as long as the temperature at which ethanol refluxes is not restricted.

[0055] <Method for manufacturing metal-organic structures> The method for producing metal-organic structures is not particularly limited, and known methods for producing metal-organic structures can be employed. Examples include one-pot synthesis methods (e.g., self-assembly, solvothermal, microwave irradiation, ionothermal, high-throughput), stepwise synthesis methods (e.g., metal-organic node structure precursor complex method, complex ligand method, in-situ sequential synthesis, post-synthesis modification), sonochemical synthesis, and mechanochemical synthesis. Among these, the solvothermal method is preferred because it yields stable thermodynamic products. The production of metal-organic structures using the solvothermal method can be carried out by referring to, for example, the literature (Shi-Bin Ren, et al. CrystEngComm, 2009, 11, 1834-1836).

[0056] The following describes an example of a method for producing a metal-organic structure containing the compound represented by the above general formula (1-3) and copper using the solvothermal method.

[0057] In the solvothermal method, for example, a mixture of a compound represented by the above general formula (1-3), a copper compound, and a solvent is heated.

[0058] Examples of copper compounds include Cu(NO3) 2· Examples of solvents include 3H2O, CuCl2, Cu(OAc)2·H2O, CuSO4·5H2O, and Cu(ClO4)2·6H2O. Examples of solvents include N,N-dimethylformamide (DMF) and water. One solvent may be used alone or in combination of two or more. When the solvent contains DMF and water, the volume ratio of DMF to water (DMF:water) may be 9:1 to 5:5, and preferably 8:2 to 6:4. Additives such as acetic acid may be added to the solvent. The amount of additive added is preferably 5 to 11 μL per 1 ml of solvent, and more preferably 9 to 11 μL.

[0059] The mixing ratio of the compound represented by the general formula (1-3) to the copper compound in the mixture is not particularly limited. When compounding, the molar ratio of the compound represented by the general formula (1-3) to the copper element contained in the copper compound (compound represented by the general formula (1-3):copper element contained in the copper compound) is preferably 1:1 to 1:4, and more preferably 1:1.5 to 1:2.5.

[0060] When producing metal-organic structures, modulators may be used to promote crystallization as needed. Examples of modulators include triphenylphosphine, pyridinium hydrochloride, and isoquinoline. The amount of modulator used when producing metal-organic structures is not particularly limited, but 0.5 to 10 equivalents, and more preferably 1 to 5 equivalents, is preferred relative to the compound represented by the general formula (1-3) above.

[0061] The amount of solvent used when manufacturing metal-organic structures is not particularly limited.

[0062] During heating, the raw material solution may be placed in any sealed container, or the heating may be carried out while refluxing the raw material solution.

[0063] The heating temperature is not particularly limited; for example, it may be 100°C or higher, or 120°C or higher, from the viewpoint of increasing reactivity, and may be 150°C or lower from the viewpoint of preventing vapor leakage during the reaction.

[0064] The heating time is not particularly limited and can be adjusted as appropriate according to the heating temperature. The heating time may be 6 hours or more, 10 hours or more, 12 hours or more, 18 hours or more, 24 hours or more, 30 hours or more, 36 hours or more, 42 hours or more, 48 hours or more, 54 hours or more, or 60 hours or more, from the viewpoint of completely completing the reaction, or it may be 96 hours or less, 84 hours or less, 72 hours or less, 60 hours or less, 48 ​​hours or less, 24 hours or less, 12 hours or less, or 10 hours or less.

[0065] Furthermore, after the reaction is complete, the obtained product may be subjected to appropriate post-treatment.

[0066] As a post-treatment, for example, the obtained product may be filtered. Alternatively, if necessary, a poor solvent may be added to the filtrate obtained by filtration, and the mixture may be dispersed at room temperature or by heating as appropriate before being filtered again. The poor solvent may be any solvent in which the target metal-organic structure is poorly soluble, such as water, acetonitrile, hexane, ethanol, or dimethylformamide. The heating temperature may be, for example, 40°C or higher, 50°C or higher, 60°C or higher, 70°C or higher, or 80°C or higher, or 100°C or lower, 90°C or lower, or 80°C or lower. The heating time may be, for example, 1 hour or more, 2 hours or more, 6 hours or more, 10 hours or more, or 12 hours or more, or 24 hours or less, or 16 hours or less.

[0067] Furthermore, the target metal-organic structure can be obtained by appropriately drying the filtrate obtained by filtration or refiltration. Here, drying may be carried out under normal pressure or under reduced pressure, but it is preferable to carry it out under reduced pressure from the viewpoint of improving efficiency. The drying temperature may be, for example, 20°C or higher, 25°C or higher, 40°C or higher, 50°C or higher, or 60°C or higher, or 100°C or lower, 90°C or lower, 80°C or lower, or 60°C or lower. The drying time may be, for example, 1 hour or more, 2 hours or more, 6 hours or more, 10 hours or more, or 12 hours or more, or 24 hours or less, or 16 hours or less.

[0068] While there are no particular limitations on the applications of metal-organic structures, unsaturated hydrocarbon scavengers are preferred due to their excellent scavenging properties for unsaturated hydrocarbons, and monoolefin scavengers and diene scavengers are more preferred due to their excellent scavenging properties for monoolefins and dienes. Monoolefin scavengers can be suitably used in monoolefin storage systems capable of storing monoolefins. Diene scavengers can be suitably used in diene storage systems capable of storing dienes. [Examples]

[0069] The present disclosure will be described below in detail based on examples, but the present disclosure is not limited to these examples.

[0070] [Synthesis of the compound represented by formula (1-1a)] The compound (3-TPPM) represented by the following formula (1-1a) was synthesized. The synthesis was carried out according to the following synthesis scheme. [ka]

[0071] <Synthesis of the compound represented by formula (II)> Trityl chloride (10.37 g, 37.2 mmol) was added to aniline (20 ml) and heated at 200 °C for 5 minutes with stirring to obtain a mixture. After thoroughly dissolving the components in the mixture, the mixture was cooled to 120 °C. Hydrochloric acid (2 M, 40 ml) and methanol (60 ml) were added to the cooled mixture and stirred under reflux at 120 °C for 1 hour. The reaction mixture was cooled to room temperature. The cooled mixture was filtered by suction to obtain a residue on filter paper. The residue was washed with water on the filter paper and then dried under reduced pressure at 80 °C to obtain the crude product of 4-Tritylaniline hydrochloride (yield: 12.49 g, 35.17 mmol). The yield was 94.5%. Acetonitrile (40 mL) was added to the entire amount of 4-Tritylaniline hydrochloride and stirred for 1 hour to obtain a mixture. Hydrochloric acid (12M, 10 mL) and hypophosphorous acid (20 mL) were added to the resulting mixture and heated at 50°C to obtain a reaction solution. Sodium nitrite (4.6 g, 67 mmol) was gradually added to the reaction solution and stirred overnight. The solid was recovered from the reaction solution by filtration. The recovered solid was washed with water and ethanol and dried for one day. The dried solid was recrystallized using hot DMF (35 mL) as the solvent to obtain crystals. The crystals were purified by sublimation to obtain the compound represented by formula (II) (Tetraphenylmethane) as a white solid (yield: 1.420 g, 2.142 mmol, yield: 12.6%).

[0072] <Synthesis of compounds represented by formula (I-II)> Tetraphenylmethane (5.120 g, 16.0 mmol) was mixed with 10 ml of bromine dropwise for 30 minutes. The mixture was cooled to -78°C (ethanol and liquid nitrogen), and then 50 ml of ethanol was slowly added to the mixture and stirred overnight. The mixture was cooled to room temperature and filtered by suction while washing with water and saturated thiosulfate solution. The residue on the filter paper was dissolved in chloroform, and recrystallization was performed using ethanol as a poor solvent to obtain the compound represented by the above formula (I-II) (Tetrakis(4-bromophenyl)methane, yield: 9.90 g, 15.56 mmol, yield: 97.3%) as pink needle-shaped crystals.

[0073] <Synthesis of the compound represented by formula (1-1a)> Tetrakis(4-bromophenyl)methane (1.440 g, 2.26 mmol), 3-pyridylboronic acid (1.968 g, 13.7 mmol), and tetrakistriphenylphosphine palladium (0.345 g, 0.331 mmol) were added to a Schlenk tube (capacity: 250 ml). The Schlenk tube was degassed and replaced with nitrogen gas three times. Then, 40 ml of toluene (degassed by bubbling with nitrogen gas), 30 ml of ethanol, and 16 ml of saturated aqueous solution of sodium carbonate (2.48 g, 2.34 mmol) were added to the Schlenk tube to obtain a mixture. The reaction of the obtained mixture was carried out under reflux at 90°C for 2 days. After the reaction, the mixture was cooled to room temperature and filtered. The organic layer was extracted from the filtrate by liquid-liquid separation. The crude product was obtained by drying the organic layer using a rotary evaporator. Column chromatography yielded the compound represented by formula (1-1a) above (3-TPPM, yield: 0.314 g, 0.500 mmol, yield: 22.1%) as a white solid from the crude product. Ethyl acetate and methanol (volume ratio (ethyl acetate:methanol = 1:2)) were used as eluates. The obtained white solid was dissolved in methanol and recrystallized to obtain colorless, transparent needle-shaped crystals.

[0074] [Synthesis of the compound represented by formula (1-2a)] The compound (4-TPPM) represented by the following formula (1-2a) was synthesized. The synthesis was carried out according to the following synthesis scheme. [ka]

[0075] Tetrakis(4-bromophenyl)methane (1.508 g, 2.37 mmol), 4-pyridylboronic acid (1.968 g, 16.0 mmol), and tetrakistriphenylphosphine palladium (0.400 g, 0.345 mmol) were added to a Schlenk tube (capacity: 250 ml). Degassing and nitrogen gas replacement of the Schlenk tube were repeated three times. Then, 60 ml of toluene, 20 ml of ethanol, and 18 ml of saturated aqueous solution of sodium carbonate (2.46 g, 2.32 mmol), which had been degassed by bubbling nitrogen gas, were added to the Schlenk tube to obtain a mixture. The reaction of the obtained mixture was carried out under reflux at 90°C for 2 days. After the reaction, the mixture was cooled to room temperature. The crude product was obtained by filtering the mixture and collecting the solid. By Soxhlet extraction using chloroform, the compound represented by the above formula (1-2a) (Tetrakis(4-(pyridinyl)phenyl)methane) (yield: 0.209 g, 0.332 mmol, yield: 14.6%) was obtained from the crude composition as a white solid.

[0076] [Synthesis of compounds represented by formula (1-3a)] The compound (pyrazolate TPM) represented by the following formula (1-3a) was synthesized. The synthesis was carried out according to the following synthesis scheme. [ka]

[0077] <Synthesis of compounds represented by formulas (I-III)> Under a nitrogen atmosphere, Tetrakis(4-bromophenyl)methane (1272 mg, 2 mmol), 1-(Tetrahydro-2H-pyran-2-yl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborlan-2-yl-)-1H-pyrazole (2502 mg, 9 mmol), and [Pd(PPh3)4] (460 mg, 0.4 mmol) were added to a Schlenk tube and degassed. A saturated NaHCO3 solution treated with nitrogen bubbles for 30 minutes, ethanol (40 mL), and toluene (80 mL) were added to the Schlenk tube to obtain a mixture. The obtained mixture was refluxed at 90°C under a nitrogen atmosphere for 2 days. The organic phase was separated from the mixture and the organic layer was allowed to dry to obtain a brown solid. This brown solid was purified by column chromatography to obtain the compound represented by the above formulas (I-III) (yield: 58%, yield: 531 mg) as a white solid.

[0078] <Synthesis of the compound represented by formula (1-3a)> Tetrakis(4-(1-(trtrahydro-2H-pyran-2-yl)-1H-pyrazol-4-yl)phenyl)methane (531 mg, 0.582 mmol) was suspended in 100 mL of ethanol, and 10 mL of 1 M hydrochloric acid was added to obtain a mixture. The mixture was refluxed at 95°C overnight and slowly cooled. A white solid was recovered by filtration of the mixture. A solution was obtained by suspending the obtained white solid in water. A saturated sodium bicarbonate aqueous solution was added to the solution so that the pH of the solution was 7-8. A white solid was recovered by filtration of the solution. The white solid was washed with water and vacuum-dried at 80°C to obtain the compound represented by the above formula (1-3a) (yield: 83%, yield: 283 mg).

[0079] 1 ¹H NMR (JEOL, 400MHz, DMSO-d6, reference: DMSO solvent residual peak set to 2.5 ppm): δ 7.197 (8H,d,J=7.200), 7.529 (8H,d,J=6.800), 8.002 (8H,s) [ka] 13 ¹³C NMR (JEOL, 400 MHz, DMSO-d6, reference: solvent residual peak of DMSO set to 39.52 ppm): δ 63.538(a), 124.607(b), 130.775(c), 130.527(d), 120.335(e), 120.774(f), 144.171(g) [ka]

[0080] 1 H-NMR spectrum (400 MHz) and 13 The 1C-NMR spectrum (400 MHz) was measured using a JEOL (JEOL) JNM-ECA400II. The sample was dissolved in deuterated dimethyl sulfoxide (DMSO-d6).

[0081] [Synthesis of metal-organic structures] (Example 1) The compound represented by the above formula (1-1a) is L 11 Therefore, the empirical formula is Cu2I2L 11 A metal-organic structure represented by the formula (1-1a) was synthesized. Specifically, 100 ml of N,N-dimethylacetamide (DMA) was heated to 165°C in an oil bath. The compound represented by the formula (1-1a) (72.0 mg, 0.115 mmol) and [Cu4I4(PPh3)4] (216.0 mg, 0.119 mmol) were dissolved in DMA to obtain a solution. After confirming that the solution had become clear and yellow, the solution was removed from the oil bath. The solution was cooled to room temperature to obtain the metal-organic structure. The obtained metal-organic structure was a yellow crystal.

[0082] (Example 2) The compound represented by the above formula (1-2a) is L 12 Therefore, the empirical formula is Cu2I2L 12A metal-organic structure represented by the formula (1-2a) was synthesized. Specifically, a solution consisting of 50 ml of DMA and 50 ml of DMSO was heated to 185°C in an oil bath. The compound represented by the formula (1-2a) (72.0 mg, 0.115 mmol) and [Cu4I4(PPh3)4] (216.0 mg, 0.119 mmol) were dissolved in the solution. After confirming that the solution had become clear and yellow, the solution was removed from the oil bath. The solution was cooled to room temperature to obtain the metal-organic structure. The obtained metal-organic structure was a yellow crystal.

[0083] (Example 3) The compound represented by the above formula (1-3a) is L 13 Therefore, the empirical formula is Ni2L 13 A metal-organic structure represented by the formula (1-3a) was synthesized. Specifically, a compound represented by the formula (1-3a) (23.4 mg, 0.04 mmol), nickel nitrate hexahydrate (23.3 mg, 0.08 mmol), N,N-dimethylformamide (DMF) (7 mL), distilled water (3 mL), and acetic acid (100 μL) were added to a Teflon® pressure vessel to obtain a mixture. The mixture was heated at 150°C for 24 hours. The mixture was cooled, and a yellow solid was filtered from the mixture. The obtained yellow solid was washed with DMF and methanol (MeOH), and dried under a nitrogen atmosphere to obtain 21.8 mg of the metal-organic structure. The obtained metal-organic structure was a yellow powder.

[0084] (Example 4) The compound represented by the above formula (1-3a) is L 13 Therefore, the empirical formula is Cu2L 13 A metal-organic structure represented by the formula (1-3a) was synthesized. Specifically, a compound represented by the formula (1-3a) (23.4 mg, 0.04 mmol), copper nitrate trihydrate (23.3 mg, 0.08 mmol), and DMF (10 mL) were added to a Teflon® pressure vessel to obtain a mixture. The mixture was heated at 150°C for 24 hours. The mixture was cooled, and a yellowish-gray solid was filtered from the mixture. The obtained yellowish-gray solid was washed with DMF and methanol (MeOH), and dried under a nitrogen atmosphere to obtain 23 mg of the metal-organic structure. The obtained metal-organic structure was a dark yellow powder.

[0085] [Measurement of gas adsorption / desorption isotherms] (Example 1) The adsorption and desorption isotherms of isoprene, 2-methyl-1-butene, and 2-methylbutane were measured for metal-organic structures. First, the solvent (DMA) adsorbed on the metal-organic structures was replaced with a solvent with low polarity and a low boiling point by Soxhlet extraction. The solvent adsorbed in the pores of the metal-organic structures interacts strongly with the metal-organic structures. Therefore, if the metal-organic structures are heated under vacuum as is, the pores may collapse. Specifically, a mixture of acetone and the metal-organic structures was refluxed in a Soxhlet tube at 90°C for 1 day. This replaced the adsorbed DMA with acetone. Next, a mixture of hexane and the metal-organic structures was refluxed in a Soxhlet tube at 90°C for 2 days. This replaced the adsorbed acetone with hexane. Hexane is expected to have less interaction and preserve the pores. The mixture was dried to obtain samples for measurement. A Microtrac-Bel fully automated gas adsorption analyzer BELSORP MAX was used to measure the adsorption and desorption isotherms. The measurement temperature was set to 25°C. The sample was ground in a mortar and pestle, and approximately 60 mg was placed in a glass measuring container and attached to the measuring device. The container was evacuated using a rotary pump and a turbomolecular pump to remove the solvent from the pores. The evacuation temperature was 50°C and the duration was 12 hours. Adsorption and desorption isotherms were measured using the sample after evacuation. The adsorption and desorption isotherm for the fourth cycle, with gas adsorption and desorption counted as one cycle, is shown in Figure 1(a). The amount of isoprene adsorbed in the fourth cycle is shown in Table 1.

[0086] (Example 2) For the metal-organic structure, a sample for measurement was obtained by replacing the solvent using the Soxhlet extraction method, in the same manner as in Example 1. The adsorption-desorption isotherm was measured in the same manner as in Example 1, except that the vacuum temperature was set to 75°C. The adsorption-desorption isotherm for the first cycle, with gas adsorption and desorption considered as one cycle, is shown in Figure 1(b). The amount of isoprene adsorbed in the first cycle is shown in Table 1.

[0087] (Examples 3 and 4) A mixture of methanol and a metal-organic structure was refluxed in a Soxhlet tube for 24 hours. The mixture was dried to obtain a sample for measurement. The adsorption-desorption isotherm was measured in the same manner as in Example 1, except that the vacuum temperature was 200°C and the vacuum time was 20 hours. The adsorption-desorption isotherm for the first cycle, with gas adsorption and desorption considered as one cycle, is shown in Figure 2(a) (Example 3) and Figure 2(b) (Example 4). The amount of isoprene adsorbed in the first cycle is shown in Table 1.

[0088] [Calculation of adsorption ratio] (Examples 1-4) The ratio of gas adsorption amounts for each example was calculated using the measurement results of gas adsorption / desorption isotherms. The ratios were calculated under conditions of 25°C and 50kPa. Specifically, the ratios of adsorption amounts for the following gases were calculated. • Molar ratio of adsorbed isoprene (IP) to adsorbed 2-methylbutane (2MB) (adsorbed isoprene:adsorbed 2-methylbutane) • Molar ratio of adsorbed isoprene to adsorbed 2-methyl-1-butene (2MB-ene) (adsorbed isoprene:adsorbed 2-methyl-1-butene) • Molar ratio of adsorbed 2-methyl-1-butene to adsorbed 2-methylbutane (adsorbed 2-methyl-1-butene: adsorbed 2-methylbutane)

[0089] The calculation was performed based on the Ideal Adsorbed Solution Theory (IAST) method, following the method described in Lee, S.; Lee, JH; Kim, J. Korean J. Chem. Eng. 2018, 35, 214-221. The results are shown in Table 1. [Measuring pore size] (Examples 1, 3-4) The pore size of the obtained metal-organic structures was measured. Specifically, the nitrogen adsorption / desorption curves of the metal-organic structures at a temperature of 77K were measured. The measurement results were analyzed using the NLDFT (Non-Local Density Functional Theory) method. The software "BELMaster" was used for the analysis. The results are shown in Table 1.

[0090] [Measurement of BET specific surface area] (Examples 1, 3-4) The BET specific surface area was measured for the obtained metal-organic structures. Specifically, the nitrogen adsorption / desorption curves of the metal-organic structures at a temperature of 77K were measured. The BET specific surface area was calculated by analyzing the measurement results using the software "BELMaster". The results are shown in Table 1.

[0091] [Powder X-ray diffraction measurement] (Example 3) Powder X-ray diffraction (PXRD) measurements were performed on the obtained metal-organic structures. A Rigaku SmartLab fully automated multi-purpose X-ray diffractometer was used for the powder X-ray diffraction measurements. At room temperature, the powder sample was irradiated with CuK characteristic X-rays (λ=1.5418Å), and the diffraction pattern was detected while rotating the sample using a D / teX Ultra(1D) detector. The results are shown in Figure 3(a). These results are before the removal of the solvent in the crystal. Furthermore, the metal-organic structure [Ni2L 13 Figure 3(a) shows the simulation results of powder X-ray diffraction of [Ni2L]. The simulation results are reported in Dinca. M, Dailly. A, Long. J. R, Chem. Eur. J. 2008, 14, 10280-10285. Metal-organic structure [Ni2L] 13 The experimental results of powder X-ray diffraction for [the substance] were in close agreement with the simulation results.

[0092] (Example 4) Powder X-ray diffraction (PXRD) measurements were performed on the obtained metal-organic structure in the same manner as in Example 3. The results are shown in Figure 3(b). These results are before the removal of the solvent from the crystal. Also, the metal-organic structure [Cu2L 13 Figure 3(b) shows the simulation results of powder X-ray diffraction of [Cu2L]. The simulation results are reported in Dinca. M, Dailly. A, Long. J. R, Chem. Eur. J. 2008, 14, 10280-10285. Metal-organic structure [Cu2L] 13 The experimental results of powder X-ray diffraction for [the substance] were in close agreement with the simulation results.

[0093] [Table 1]

[0094] Table 1 shows the literature values ​​(see Kim, S., Ahn, W., catalysis today, 2013, 204, 85-93.) for the metal-organic structures MIL-125 and NH2-MIL-125, including pore size, BET specific surface area, isoprene adsorption amount, and the ratio of isoprene adsorption amount to 2-methylbutane adsorption amount.

Claims

1. An unsaturated hydrocarbon scavenger having at least one carbon-carbon double bond, It contains a metal-organic structure having a metal and a ligand coordinated to the metal, The ligand includes a compound having a nitrogen-containing aromatic heterocycle, An unsaturated hydrocarbon scavenger, wherein the nitrogen-containing aromatic heterocycle compound includes a compound represented by the following general formula (1). 【Chemistry 1】 [In the formula, Ar1 to Ar4 each independently represent a monovalent nitrogen-containing aromatic heterocyclic group, and X1 to X4 each independently represent an integer from 1 to 3.]

2. The unsaturated hydrocarbon scavenger according to claim 1, wherein the unsaturated hydrocarbon captured by the unsaturated hydrocarbon scavenger includes a chain-like diolefin having 4 to 5 carbon atoms.

3. The unsaturated hydrocarbon scavenger according to claim 1, wherein the unsaturated hydrocarbon captured by the unsaturated hydrocarbon scavenger includes a chain-like monoolefin having 4 to 5 carbon atoms.

4. The unsaturated hydrocarbon scavenger according to any one of claims 1 to 3, wherein the metal comprises metals from groups 2 to 14 of the periodic table.

5. The unsaturated hydrocarbon scavenger according to any one of claims 1 to 4, wherein the nitrogen-containing aromatic heterocycle compound comprises at least one compound selected from the group consisting of compounds represented by the following general formulas (1-1) to (1-3). 【Chemistry 2】 [In the formula, X １ ~X ４ Each of these independently represents an integer between 1 and 3. 【Transformation 3】 [In the formula, X １ ~X ４ Each of these independently represents an integer between 1 and 3. 【Chemistry 4】 [In the formula, X １ ~X ４ Each of these independently represents an integer between 1 and 3.

6. The unsaturated hydrocarbon scavenger according to any one of claims 1 to 5, wherein the ligand further comprises a halogen.

7. The aforementioned metal includes Cu, The ligand further includes I, The nitrogen-containing aromatic heterocycle compound includes the compound represented by the general formula (1-1), The compound represented by the general formula (1-1) is L １ , wherein the composition formula of the metal-organic framework is Cu ２ I ２ L １ The unsaturated hydrocarbon scavenger according to claim 5, which is represented by .

8. The aforementioned metal includes Cu, The ligand further includes I, The nitrogen-containing aromatic heterocycle compound includes the compound represented by the general formula (1-2), The compound represented by the general formula (1-2) above is L ２ Therefore, the composition formula of the metal-organic structure is Cu ２ I ２ L ２ An unsaturated hydrocarbon scavenger according to claim 5, represented as shown in the image.

9. The aforementioned metal contains Ni, The nitrogen-containing aromatic heterocycle compound includes the compound represented by the general formula (1-3), The compound represented by the general formula (1-3) above is L ３ Therefore, the composition formula of the metal-organic structure is Ni ２ L ３ An unsaturated hydrocarbon scavenger according to claim 5, represented as shown in the image.

10. The aforementioned metal includes Cu, The nitrogen-containing aromatic heterocycle compound includes the compound represented by the general formula (1-3), The compound represented by the general formula (1-3) above is L ３ Therefore, the composition formula of the metal-organic structure is Cu ２ L ３ An unsaturated hydrocarbon scavenger according to claim 5, represented as shown in the image.

11. Compounds represented by the following general formulas (1-3). 【Transformation 5】 [In the formula, X １ ~X ４ Each of these independently represents an integer between 1 and 3.

12. It contains a metal-organic structure having a metal and a ligand coordinated to the metal, The aforementioned metal includes a metal composed of first transition series elements, A metal-organic structure wherein the ligand comprises the compound described in claim 11.

Images