Flocculation and rapid filtration of metal-organic frameworks

Abstract

Provided herein is a method for producing a metal-organic framework, comprising forming a suspension capable of producing a metal-organic framework; inducing flocculation of the suspension to form a plurality of flocs; separating the flocs from the suspension to produce a solid phase comprising the metal-organic framework and a supernatant liquid phase; separating the solid phase from the supernatant liquid phase; and recovering the metal-organic framework from the solid phase. The method of the invention comprises dissolving a metal salt and at least one ligand in a solvent to form a suspension.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 191,585, filed May 21, 2021, which is incorporated by reference in its entirety herein.

[0002] The present disclosure relates generally to methods for producing metal-organic frameworks, and specifically to flocculation of metal-organic frameworks in a synthesis suspension or slurry to enable more rapid and efficient settling of the metal-organic frameworks and provide increased space-time yield of the synthesis. [Background technology]

[0003] Metal-organic frameworks can be synthesized using a mixture of metal salts, organic ligands, water and organic solvents. As part of the synthesis, the metal-organic frameworks are suspended in a liquid phase or dispersion as a solid phase. The metal-organic frameworks are then isolated and purified by filtration and washing. The filtration and washing steps are inefficient and time-consuming, reducing the productivity of the synthesis and often resulting in poor properties. The settling times required for these materials and the washing steps are often bottlenecks encountered during synthesis. Faster and more efficient isolation and purification allows for faster production of materials and improved space-time yields. Summary of the Invention

[0004] Provided herein is a method of producing a metal-organic framework, comprising forming a suspension capable of producing a metal-organic framework, producing the metal-organic framework, inducing flocculation of the suspension to form a plurality of flocs, separating the flocs from the suspension to produce a solid phase comprising the metal-organic framework and a supernatant liquid phase, separating the solid phase from the supernatant liquid phase, and recovering the metal-organic framework. The method further comprises dissolving a metal salt and at least one ligand in a non-aqueous solvent to form a suspension.

[0005] Also provided herein is a method for enhancing the settling rate of a metal-organic framework in a suspension, comprising the steps of: providing a suspension of the metal-organic framework; adding a flocculating agent to the suspension to form a plurality of flocs comprising aggregates of the metal-organic framework particles; and settling the plurality of flocs from the suspension to produce a metal-organic framework having approximately the same surface area as a metal-organic framework produced under the same process conditions but without the flocculating agent.

[0006] Further provided herein is a method of making a metal-organic framework, the method comprising: (a) forming a metal-organic framework in a suspension; (b) adding a flocculating agent to the suspension to form a plurality of aggregates of the metal-organic framework; (c) precipitating the plurality of aggregates of the metal-organic framework from the suspension to form a solid phase comprising the metal-organic framework and a liquid phase; and (d) filtering the solid phase from the liquid phase to provide the metal-organic framework. The suspension comprises a plurality of solid reagents in at least one non-aqueous solvent. The solid reagents comprise at least one metal salt and at least one ligand.

[0007] These and other features and attributes of the disclosed methods, as well as their advantageous applications and / or uses, will become apparent from the following detailed description. [Brief description of the drawings]

[0008] To assist those of ordinary skill in the art in making and using the invention described herein, reference is made to the accompanying drawings. [Figure 1A] 1 shows powder X-ray diffraction ("pXRD") patterns of Mg-MOF-74 produced with and without the flocculation step as described in Example 1. [Figure 1B] 1 shows N2 isotherms obtained at 77 K for Mg-MOF-74 produced with and without the flocculation step as described in Example 1. [Figure 2A] 1 provides pXRD patterns of Mg-MOF-74 with and without flocculation as described in Examples 2 and 3. [Figure 2B] 1 provides N2 isotherms obtained at 77 K for Mg-MOF-74 with and without flocculation as described in Examples 2 and 3. [Figure 3A] 1 provides pXRD patterns of UiO-66 with and without flocculation as described in Example 4. [Figure 3B] 1 provides N2 isotherms obtained at 77 K for UiO-66 with and without flocculation as described in Example 4. [Figure 4A] pXRD patterns of HKUST-1 with and without flocculation as described in Example 5 [Figure 4B] 1 provides N2 isotherms obtained at 77 K for HKUST-1 with and without flocculation as described in Example 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Before the present methods and devices are disclosed and described, it is to be understood that, unless otherwise specified, this invention is not limited to particular compounds, components, compositions, reactants, reaction conditions, ligands, catalyst structures, metallocene structures, etc. It is also to be understood that the terminology used herein is for the purpose of describing some embodiments only and is not intended to be limiting.

[0010] All numerical values ​​within the detailed description and claims herein are modified by "about" or "approximately" with respect to the indicated value to account for experimental error and variations that would be expected by one of ordinary skill in the art. Unless otherwise indicated, room temperature is about 25°C.

[0011] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, just as a range from any lower limit can be combined with any upper limit to describe a range not explicitly described, a range from any lower limit can be combined with any other lower limit to describe a range not explicitly described, and similarly, a range from any upper limit can be combined with any other upper limit to describe a range not explicitly described. Furthermore, a range includes every point or individual value between its endpoints, even if not explicitly described. Thus, every point or individual value can be combined with any other point or individual value, or with any other lower or upper limit, to serve as its own lower or upper limit to describe a range not explicitly described.

[0012] For purposes of this disclosure, the following definitions apply. As used herein, the terms "a" and "the" are understood to encompass the plural as well as the singular.

[0013] The term "aryl" refers to a polyunsaturated aromatic substituent, which may be a single ring or multiple fused or covalently linked rings, unless otherwise specified. In one embodiment, the substituent has 1-11 rings, more specifically 1-3 rings. The term "heteroaryl" refers to an aryl substituent (or ring) containing 1-4 heteroatoms selected from N, O and S, where the nitrogen and sulfur atoms are optionally oxidized and the nitrogen atoms are optionally quaternized. Exemplary heteroaryl groups are 6-membered azines, such as pyridinyl, diazinyl and triazinyl. Heteroaryl groups can be attached to the remainder of the molecule through a heteroatom. Non-limiting examples of aryl and heteroaryl groups include phenyl, 1-naphthyl, 2-naphthyl, 4-biphenyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 3-pyrazolyl, 2-imidazolyl, 4-imidazolyl, pyrazinyl, 2-oxazolyl, 4-oxazolyl, 2-phenyl-4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, and 5-isoxazolyl. aryl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 2-furyl, 3-furyl, 2-thienyl, 3-thienyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidyl, 4-pyrimidyl, 5-benzothiazolyl, purinyl, 2-benzimidazolyl, 5-indolyl, 1-isoquinolyl, 5-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl, 3-quinolyl, and 6-quinolyl. Substituents for each of the above noted aryl and heteroaryl ring systems are selected from the group of acceptable substituents described below.

[0014] As used herein, the terms "alkyl", "aryl" and "heteroaryl" may optionally include both substituted and unsubstituted forms of the indicated species. Substituents for aryl and heteroaryl groups are generally referred to as "aryl group substituents". Substituents may be selected, for example, from the following: groups attached to the heteroaryl or heteroarene nucleus via a carbon or heteroatom (e.g., P, N, O, S, Si, or B), including, but not limited to, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocycloalkyl, -OR', =O, =NR', =N-OR', -NR'R'', -SR', -halogen, -SiR'R''R''', -OC(O)R', -C(O)R', -CO2R', -CONR'R'', -OC(O)NR'R'', -NR''C(O)R', -NR'-C(O)NR''R''', -NR''C(O)2R', -NR-C(NR'R''R'')=NR'''', -NR-C(NR'R'')=NR''', -S(O)R', -S(O)R', -S(O)NR'R'', -NRSOR', -CN and -R', -CH(Ph), fluoro(C1-C4)alkoxy, and fluoro(C1-C4)alkyl number from 0 to the total number of open valences in the aromatic ring system. Each of the above groups is attached to an aryl or heteroaryl nucleus directly or through a heteroatom (e.g., P, N, O, S, Si, or B); and where R', R'', R''', and R'''' can be independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl. When a compound contains more than one R group, for example, each of the R groups is independently selected, as are each R', R'', R''', and R'''' groups when more than one of these groups is present.

[0015] The term “alkyl,” by itself or as part of another substituent, means, unless otherwise stated, straight- or branched-chain, or cyclic hydrocarbon radicals, or combinations thereof, which may be fully saturated or mono- or polyunsaturated, and have the specified number of carbon atoms (i.e., C1 to C6). 10 means 1 to 10 carbons. Examples of saturated hydrocarbon groups include, but are not limited to, groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl, cyclohexyl, (cyclohexyl)methyl, cyclopropylmethyl, homologs and isomers of, e.g., n-pentyl, Congeners and isomers include n-hexyl, n-heptyl, n-octyl, and the like. Unsaturated alkyl groups are those that have one or more double or triple bonds. Examples of unsaturated alkyl groups include, but are not limited to, vinyl, 2-propenyl, crotyl, 2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl, 3-(1,4-pentadienyl), ethynyl, 1- and 3-propynyl, 3-butynyl, and higher homologs and isomers. The term "alkyl," unless otherwise noted, is also meant to include any of the derivatives of alkyl defined in more detail below, such as "heteroalkyl."

[0016] The terms "halo" or "halogen," by themselves or as part of another substituent, mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom.

[0017] As used herein, "isotherm" refers to the adsorption of an adsorbate as a function of concentration while the temperature of the system is held constant. In an embodiment, the adsorbate is CO2 and the concentration can be measured as CO2 pressure. As described herein, isotherms can be performed using porous materials and various mathematical models applied to calculate the apparent surface area. Brunauer, S. et al., Adsorption Gas in Multimolecular Layers, J. Am. Chem. Walton, K. et al., Applicability of BET Method for Determining Surface Areas of Microporous Metal-Organic Frameworks, J. Am. Chem. Chem. Soc. 129, 8552-8556, 2007; Langmuir, I., J. The Constitution of Fundamental Properties of Solids and Liquids, Part 1.Solids, Am. Chem. Soc., 38, 2221-2295, 1916.

[0018] As used herein, the term "ligand" refers to a molecule that contains one or more substituents that can function as a Lewis base (electron donor). In one embodiment, the ligand may be an oxygen, phosphorus, or sulfur-containing molecule. In one embodiment, the ligand may be an amine or an amine containing 1-10 amine groups.

[0019] The symbol "R" is a general abbreviation that represents a substituent selected from H, substituted or unsubstituted alkyl groups, substituted or unsubstituted heteroalkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, and substituted or unsubstituted heterocycloalkyl groups.

[0020] As used herein, the term "Periodic Table" refers to the International Union of Pure and Applied Chemistry (IUPAC) Periodic Table of the Elements dated December 2015.

[0021] The term "salt" includes salts of compounds prepared by neutralization of an acid or base, depending on the specific ligand or substituents found on the compounds described herein. When a compound contains a relatively acidic functional group, a base addition salt can be obtained by contacting the neutral form of such a compound with a sufficient amount of a desired base, either neat or in a suitable inert solvent. Examples of base addition salts include sodium salts, potassium salts, calcium salts, ammonium salts, organic amino salts, magnesium salts, or similar salts. Examples of acid addition salts include those derived from inorganic acids such as hydrochloric acid, hydrobromic acid, nitric acid, carbonic acid, monohydrogencarbonic acid, phosphoric acid, monohydrogenphosphoric acid, dihydrogenphosphoric acid, sulfuric acid, monohydrogensulfuric acid, hydroiodic acid, phosphoric acid, and the like, as well as salts derived from relatively non-toxic organic acids such as acetic acid, propionic acid, isobutyric acid, butyric acid, maleic acid, malic acid, malonic acid, benzoic acid, succinic acid, suberic acid, fumaric acid, lactic acid, mandelic acid, phthalic acid, benzenesulfonic acid, p-tolylsulfonic acid, citric acid, tartaric acid, methanesulfonic acid, and the like. Certain compounds of the present disclosure contain both basic and acidic functionalities, allowing the compounds to be converted into either base or acid addition salts. Hydrates of salts are also included.

[0022] In compounds described herein having one or more chiral centers, when the absolute stereochemistry is not specified, it is understood that each center may be independently R-configuration or S-configuration, or a mixture thereof. Thus, the compounds provided herein may be enantiomerically pure or may be a mixture of stereoisomers. In addition, in compounds described herein having one or more double bonds that generate geometric isomers that can be defined as E or Z, it is understood that each double bond may be independently E or Z, or a mixture thereof. Similarly, it is understood that in any compound described, all tautomeric forms are also intended to be included.

[0023] Furthermore, the compounds provided herein may contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute such compounds. For example, the compounds may contain isotopes of, for example, tritium ( 3 H), Iodine-125( 125 I) or carbon-14 ( 14 C). All isotopic variations of the subject compounds, whether radioactive or not, are intended to be encompassed within the scope of the present disclosure.

[0024] As used herein, the term "metal-organic framework material" or "MOF material" refers to a metal or metalloid and an organic ligand capable of coordinating with the metal or metalloid. In some embodiments, the MOF coordination network of the organic ligands and the metal (or metalloid) forms a porous three-dimensional structure.

[0025] As used herein, a "metal organic framework" may be a mixed metal organic framework or a metal organic framework system or a mixed metal mixed organic framework system as described in WO 2020 / 219907.

[0026] (Metal-Organic Frameworks) Metal-organic frameworks ("MOFs") are a class of highly porous materials that have potential applications in a wide range of fields, including gas storage, gas and liquid separation, isomer separation, waste removal, and catalysis. In contrast to zeolites, which are purely inorganic, MOFs can utilize organic ligands that act as "pillars" to bridge metal atoms or metal atom clusters. Like zeolites, MOFs are microporous. The shape and size of the pores in metal-organic frameworks ("MOFs") can be tailored by the choice of organic ligands and metals. The organic ligands can be modified, resulting in MOFs with a variety of structures that differ from zeolites as a whole. Factors that influence the structure of MOFs include, for example, one or more of the following: density of the ligands, size and type of the coordinating groups, additional substitutions at or near the coordinating groups, size and shape of the ligands, hydrophobicity or hydrophilicity of the ligands, choice of metal and / or metal salt, choice of solvent, and reaction conditions such as temperature, concentration, etc.

[0027] Metal-organic frameworks (MOFs) are materials that contain metals and multitopic organic linkers that self-assemble to form coordination networks. MOFs have a wide range of potential uses in many different applications including gas storage, gas separation, catalysis, sensing, and environmental cleanup.

[0028] As provided herein, the metal-organic framework may be ZIF (or Zeolitic Imidazolate Frameworks), MIL (or Materiaux de l'Institut Lavoisier), IRMOF (or IsoReticular Metal Organic Frameworks), alone or in combination with other MOFs. In some embodiments, the MOF is selected from HKUST-1, MOF-74, MIL-100, ZIF-7, ZIF-8, ZIF-90, UiO-66, UiO-67, MOF-808, or MOF-274. In one embodiment, the metal-organic framework is selected from the group of HKUST-1, UiO-66, ZIF-8, ZIF-7, MIL-100, MOF-74, M2(m-dobdc), MOF-274, Cu(Qc)2, and combinations thereof.

[0029] MOFs can be made with an organic ligand or a combination of one or more organic ligands and a combination of a metal or metalloid, as described below. For example, MOF-274 and EMM-67 contain Mg 2+ , Mn 2+ , Fe 2+ , Zn 2+ , Ni 2+ , Cu 2+ , Co 2+ or a combination thereof with 4,4'-dihydroxy-(1,1'-biphenyl)-3,3'-dicarboxylic acid. Additionally, MOF-274 can contain amines coordinated to metal sites within its structure.

[0030] (organic ligand) As used herein, an organic ligand is a monodentate, bidentate, or polydentate ligand. The organic ligand may be a single type of ligand or a combination thereof. In general, the organic ligand is capable of coordinating with a metal ion, and in principle, any compound suitable for such coordination may be used. An organic ligand containing at least two centers is capable of coordinating with a metal ion of a metal salt, or a metal or metal salt. In one embodiment, the organic ligand comprises (i) an alkyl group moiety having 1-10 carbon atoms, (ii) an aryl group moiety having 1-5 aromatic rings, (iii) an alkyl or arylamine moiety comprising an alkyl group having 1-10 carbon atoms or an aryl group having 1 to 5 aromatic rings, where the moiety has at least two functional groups "X" covalently bonded to the moiety, and X is capable of coordinating with a metal or metalloid.

[0031] In one embodiment, each X is independently selected from the neutral or ionic forms of CO2H, OH, SH, NH2, CN, HCO, CS2H, NO2, SO3H, Si(OH)3, Ge(OH)3, Sn(OH)3, Sn(SH)3, PO3H, CH(RSH)2, C(RSH)3, CH(RNH2)2, C(RNH2)3, CH(ROH)2, C(ROH)3, CH(RCN)2, C(RCN)3, CH(SH)2, C(SH)3, CH(NH2)2, C(NH2)2, CH(OH)2, C(OH)3, CH(CN)2, C(CN)3, a nitrogen-containing heterocycle, a sulfur-containing heterocycle, and combinations thereof, where R is an alkyl group having 1-5 carbon atoms, or an aryl group containing 1-2 phenyl rings.

[0032] In one embodiment, the organic ligands contain at least one heteroatom including substituted or unsubstituted, mono- or polynuclear aromatic di-, tri-, and tetracarboxylic acids, and substituted or unsubstituted, aromatic di-, tri-, and tetracarboxylic acids, which have one or more nuclei.

[0033] In one embodiment, the organic ligand is benzenetricarboxylate (BTC) (one or more isomers), ADC (acetylene dicarboxylate), NDC (naphthalene dicarboxylate) (any isomer), BDC (benzene dicarboxylate) (any isomer), ATC (adamantane tetracarboxylate) (any isomer), BTB (benzene tetrabenzoate) (any isomer), MTB (methane tetrabenzoate), ATB (adamantane tetrabenzoate) (any isomer), biphenyl-4,4'-dicarboxylate, benzene-1,3,5-tris(1H-tetrazole), imidazole, or derivatives thereof, or combinations thereof.

[0034] Ligands with multidentate functional groups can be coupled to the corresponding countercations, e.g., H + , Na + , K + , Mg 2+ , Ca 2+ , Sr 2+ , ammonium ions, alkyl-substituted ammonium ions, aryl-substituted ammonium ions, and aryl-substituted ammonium ions, or counter anions, such as F - , Cl - , Br - , I - , ClO - , ClO2 - , ClO3 - , ClO4 - , O.H. - , NO3 - , NO2 - , SO4 2- , SO3 2- , PO4 3- , CO3 2- , and HCO3 - may include:

[0035] In one embodiment, the organic ligand comprises a monodentate functional group. A monodentate functional group is defined as a moiety attached to a moiety that can comprise an organic ligand or an amine ligand moiety L as defined above, and can form only one bond to a metal ion. According to this definition, a ligand can comprise one or more monodentate functional groups. For example, cyclohexylamine and 4,4'-bipyridine are ligands that comprise a monodentate functional group, since each functional group can only bind to one metal ion.

[0036] Thus, cyclohexylamine is a monofunctional ligand containing a monodentate functional group, and 4,4'-bipyridine is a bifunctional ligand containing two monodentate functional groups. Specific examples of ligands containing monodentate functional groups include pyridine, a monofunctional ligand, hydroquinone, a bifunctional ligand, and 1,3,5-tricyanobenzene, a trifunctional ligand.

[0037] Ligands with monodentate functional groups can be blended with ligands containing multidentate functional groups to make MOFs in the presence of suitable metal ions and, optionally, a template agent. Monodentate ligands can also be used as template agents. Template agents can be added to the reaction mixture to occupy the pores of the resulting MOF. Monodentate ligands and / or template agents can include the following substances and / or derivatives thereof: A. Alkylamines or arylamines or phosphines and their corresponding ammonium or phosphonium salts, the alkylamines or phosphines can contain linear, branched, or cyclic aliphatic groups (and their corresponding ammonium salts) having 1 to 20 carbon atoms, and the arylamines or phosphines can contain 1 to 5 aromatic rings, including heterocycles. Examples of monofunctional amines are methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, sec-butylamine, isobutylamine, tert-butylamine, n-pentylamine, neopentylamine, n-hexylamine, pyrrolidine, 3-pyrroline, piperidine, cyclohexylamine, morpholine, pyridine, pyrrole, aniline, quinoline, isoquinoline, 1-azaphenanthrene, and 8-azaphenanthrene. Examples of di- and trifunctional amines are 1,4-diaminocyclohexane, 1,4-diaminobenzene, 4,4'-bipyridyl, imidazole, pyrazine, 1,3,5-triaminocyclohexane, 1,3,5-triazine, 1,3,5-triaminobenzene. B. Alcohols containing an alkyl or cycloalkyl group containing 1-20 carbon atoms or an aryl group containing 1-5 phenyl rings. Examples of monofunctional alcohols are methanol, ethanol, n-propanol, isopropanol, allyl alcohol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol, sec-pentanol, neopentanol, n-hexanol, cyclohexanol, phenol, benzyl alcohol, and 2-phenylethanol. Examples of difunctional and trifunctional alcohols are 1,4-dihydroxycyclohexane, hydroquinone, catechol, resorcinol, 1,3,5-trihydroxybenzene, and 1,3,5-trihydroxycyclohexane. C. Ethers containing an alkyl or cycloalkyl group containing 1 to 20 carbon atoms, or an aryl group containing 1 to 5 phenyl rings. Examples of ethers are diethyl ether, furan, and morpholine. D. Thiols containing an alkyl or cycloalkyl group containing 1-20 carbon atoms, or an aryl group containing 1-5 phenyl rings. Examples of monofunctional thiols are thiomethane, thioethane, thiopropane, thiocyclohexane, thiophene, benzothiophene, and thiobenzene. Examples of difunctional and trifunctional thiols are 1,4-dithiocyclohexane, 1,4-dithiovertosene, 1,3,5-trithiocyclohexane, and 1,3,5-trithiobenzene. E. Nitriles containing an alkyl or cycloalkyl group containing 1-20 carbon atoms, or an aryl group containing 1-5 phenyl rings. Examples of monofunctional nitriles are acetonitrile, propanenitrile, butanenitrile, n-valeronitrile, benzonitrile, and p-tolunitrile. Examples of difunctional and trifunctional nitriles are 1,4-dinitrilocyclohexane, 1,4-dinitrilobenzene, 1,3,5-trinitrilocyclohexane, and 1,3,5-trinitrilobenzene. F. Inorganic anions from the group consisting of sulfate, nitrate, nitrite, sulfite, bisulfite, phosphate, hydrogen phosphate, dihydrogen phosphate, diphosphate, triphosphate, phosphite, chloride, chlorate, bromide, bromate, iodide, iodate, carbonate, bicarbonate, thiocyanide and isonitrile, as well as the corresponding acids and salts of the aforementioned inorganic anions. G. Organic Acids and Corresponding Anions (and Salts). Organic acids can include alkyl organic acids containing linear, branched, or cyclic aliphatic groups having 1-20 carbon atoms, or aryl organic acids having 1-5 aromatic rings, which may include heterocycles, and the corresponding aryl organic anions and salts. H. Other organic and inorganic substances such as ammonia, carbon dioxide, methane, oxygen, ethylene, hexane, benzene, toluene, xylene, chlorobenzene, nitrobenzene, naphthalene, thiophene, pyridine, acetone, 1-2-dichloroethane, methylene chloride, tetrahydrofuran, ethanolamine, triethylamine or trifluoromethylsulfonic acid.

[0038] Additionally, the templating agent can include other aliphatic and aromatic hydrocarbons that do not contain functional groups, hi one embodiment, the templating agent includes a cycloalkane, such as cyclohexane, adamantane, or norbornene, and / or an aromatic, such as benzene, toluene, or xylene.

[0039] (Metal ions) As mentioned above, MOFs can be synthesized by combining metal ions, organic ligands, and optionally a suitable templating agent. Suitable metal ions include metals and metalloids of various coordination geometries and oxidation states. In one embodiment, MOFs are produced using metal ions with distinctly different coordination geometries in combination with ligands with multidentate functional groups and a suitable templating agent. MOFs can be prepared using metal ions that prefer octahedral coordination, such as cobalt(II), and / or metal ions that prefer tetrahedral coordination, such as zinc(II). MOFs can be produced using one or more of the following metal ions: Mg 2+ , Ca 2+ , Sr 2+ , B.A. 2+ , Sc 3+ , Y 3+ , Ti 4+ , Zr 4+ , Hf 4+ , V 5+ , V 4+ , V 3+ , V 2+ , Nb 3+ , Ta 3+ , Cr 3+ , Mo 3+ , W 3+ , Mn 3+ , Mn 2+ , Re 3+ , Re 2+ , Fe 3+ , Fe 2+ , Ru 3+ , Ru 2+ , Os 3+ , Os 2+ , Co 3+ , Co 2+ , Rh 2+ , Rh +, Ir 2+ , Ir + , Ni 2+ , Ni + , Pd 2+ , Pd + , Pt 2+ , Pt + , Cu 2+ , Cu + , Ag + , Au + , Zn 2+ , Cd 2+ , Hg 2+ , Al 3+ , Ga 3+ , In 3+ , Tl 3+ , Si 4+ , Si 2+ , Ge 4+ , Ge 2+ , Sn 4+ , Sn 2+ , Pb 4+ , Pb 2+ , As 5+ , As 3+ , As + , Sb 5+ , Sb 3+ , Sb + , Bi 5+ , Bi 3+ , Bi + , B.E. 2+ and the corresponding metal salt counterion. The term metal ion refers to both metal ions and metalloid ions. In one embodiment, metal ions suitable for use in the preparation of MOFs can include: Sc 3+ , Ti 4+ , V 4+ , V 3+ , V 2+ , Cr 3+ , Mo 3+ , Mg 2+ , Mn 3+ , Mn 2+ , Fe 3+ , Fe 2+ , Ru 3+ , Ru 2+ , Os 3+ , Os 2+ , Co 3+ , Co 2+ , Rh 2+ , Rh+ , Ir 2+ , Ir + , Ni 2+ , Ni + , Pd 2+ , Pd + , Pt 2+ , Pt + , Cu 2+ , Cu + , Ag + , Au + , Zn 2+ , Cd 2+ , Al 3+ , Ga 3+ , In 3+ , Ge 4+ , Ge 2+ , Sn 4+ , Sn 2+ , Pb 4+ , Pb 2+ , Sb 5+ , Sb 3+ , Sb + , and / or Bi 5+ , Bi 3+ , Bi + , B.E. 2+ together with the counter anion of the corresponding metal salt. In one embodiment, the metal ions used in the preparation of the MOF include: Sc 3+ , Ti 4+ , V 4+ , V 3+ , Cr 3+ , Mo 3+ , Mn 3+ , Mn 2+ , Fe 3+ , Fe 2+ , Co 3+ , Co 2+ , Ni 2+ , Ni + , Cu 2+ , Cu + , Ag + , Zn 2+ , Cd 2+ , Al 3+ , Sn 4+ , Sn 2+ , and / or Bi 5+ , Bi 3+ , Bi +with the corresponding metal salt counterion. In one embodiment, the metal ion for use in the preparation of the MOF is selected from the group including: Mg 2+ , Mn 3+ , Mn 2+ , Fe 3+ , Fe 2+ , Co 3+ , Co 2+ , Ni 2+ , Ni + , Cu 2+ , Cu + , Pt 2+ , Ag + , and Zn 2+ , as well as the corresponding metal salt counterions.

[0040] (Preparation of Metal-Organic Frameworks) The synthesis of rigid, stable metal-organic frameworks ("MOFs") can be carried out under mild reaction conditions where the reagents are combined in solution (in an open beaker) using synthesis reaction temperatures ranging from 0°C to 100°C. Alternatively, the solution reaction may be carried out in a closed vessel at temperatures between 25°C and 300°C. In either case, a crystalline, microporous solid or powder is formed.

[0041] In the preparation of metal-organic frameworks, the reactants are added in a molar ratio of 1:10 to 10:1 of metal ion to ligand containing polydentate functionality. In one embodiment, the ratio of metal ion to ligand containing polydentate functionality is 1:3 to 3:1, such as 1:2 to 2:1. The amount of template agent affects the preparation, and in fact, in some circumstances, the template agent can be employed as the solvent in which the reaction occurs. The template agent can be employed in excess accordingly without interfering with the reaction or the overall synthesis. Furthermore, when a ligand containing monodentate functionality is used in combination with the metal ion and a ligand containing polydentate functionality, the ligand containing monodentate functionality can be employed in excess. In certain circumstances, the ligand containing monodentate functionality can be utilized as the solvent in which the reaction occurs. Additionally, in certain circumstances, the template agent and the ligand containing monodentate functionality can be the same. An example of a templating agent that is a ligand containing monodentate functionality is pyridine.

[0042] To prepare metal-organic frameworks, the reaction is carried out in a non-aqueous system. The solvent can be polar or non-polar, and the solvent can be a template agent or any ligand containing a monodentate functional group. Examples of non-aqueous solvents include pentane, hexane, benzene, toluene, xylene, chlorobenzene, nitrobenzene, cyanobenzene, aniline, naphthalene, naphthanes; n-alcohols such as methanol, ethanol, n-propanol, isopropanol; acetone, 1,2,-dichloroethane, methylene chloride, chloroform, carbon tetrachloride, tetrahydrofuran, dimethylformamide, dimethylsulfoxide, thiophene, pyridine, ethanolamine, triethylamine, ethylenediamine, etc.

[0043] To form large single crystals of microporous materials suitable for X-ray structural analysis, solution reactions can be carried out in the presence of viscous materials such as polymeric additives. Specific additives include polyethylene oxide, polymethylmethacrylate, silica gel, agar, fat, collagen, etc., which can aid in achieving high yields and pure crystalline products. The growth of large single crystals of microporous materials leads to unambiguous characterization of the microporous scaffold. Large single crystals of microporous materials are useful for magnetic and electronic sensing applications.

[0044] (optional additive) Additionally, the metal-organic framework coating layer may contain fillers, antioxidants (e.g., hindered phenols such as IRGANOX® 1010 or IRGANOX® 1076 available from Ciba-Geigy), inhibitors of photo-oxidation (e.g., hindered amine light stabilizers, HALS, such as TINUVN® 123 available from BASF), phosphites (e.g., IRGAFOS® 168 available from Ciba-Geigy), anti-cleaning additives, tackifiers such as polybutenes, terpene resins, aliphatic and aromatic hydrocarbon resins, alkali metal and glycerol stearates, and hydrogenated rosins, UV stabilizers; heat stabilizers, antiblocking agents, release agents, antistatic agents, pigments; colorants, dyes, waxes, silicas, fillers, and talc.

[0045] Other optional additives include precipitated silica, silica derived from by-products such as fly ash, e.g., silica-alumina, silica-calcium particles, fumed silica, etc. In one embodiment, the silica is a particulate material and has an average particle size of 10 μm or less, e.g., 5 μm or less, or 1 μm or less. In one embodiment, the silica is amorphous silica.

[0046] Other additives that may be optionally included in the metal-organic coating layer include inorganic compounds such as titanium dioxide, hydrated titanium dioxide, hydrated alumina or alumina derivatives, mixtures of silicon and aluminum compounds, silicon compounds, clay minerals, alkoxysilanes, amphiphilic materials, etc. The additives may also include any suitable compound used for adhesion of powdered materials, such as oxides of silicon, aluminum, boron, phosphorus, zirconium, and / or titanium. In addition, additives may include oxides of magnesium and oxides of beryllium. In addition, tetraalkoxysilanes may be used as additives, such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane, similar tetraalkoxytitanium and tetraalkoxyzirconium compounds, and trimethoxy-, triethoxy-, tripropoxy-, and tributoxy-aluminum.

[0047] (Current method) Metal-organic frameworks are prepared by the reaction of presynthesized or commercially available ligands with metal ions. Another approach is called "in situ linker synthesis", where the organic ligands, also called "linkers", can be generated in situ in the reaction medium from the starting materials.

[0048] When synthesizing metal-organic frameworks, organic molecules are not only structure-directing agents, but also reactants that are incorporated as part of the framework structure. With this in mind, traditional synthesis allows for higher reaction temperatures. Solvothermal reaction conditions, structure-directing agents, mineralizers, as well as microwave-assisted synthesis and steam-assisted transformations have also been introduced recently.

[0049] Conventional synthesis can be carried out by conventional electrical heating without parallel reactions. In conventional synthesis, the reaction temperature is often a parameter in the synthesis of metal-organic frameworks, and two temperature ranges are distinguished, solvothermal and non-solvothermal, that define the reaction set-up utilized. Solvothermal reactions are often carried out in a closed vessel under autogenous pressure, around the boiling point of the solvent used. Non-solvothermal reactions are carried out at ambient pressure, below or at the boiling point, simplifying the synthesis requirements. Non-solvothermal reactions can be further classified as room temperature or elevated temperature.

[0050] The synthesis of metal-organic frameworks is often carried out in a solvent at temperatures ranging from room temperature to about 250 °C. Heat is transferred from a high temperature source, an oven, by convection. Alternatively, energy can be introduced mechanically, by electrical potential, electromagnetic radiation, mechanical waves (ultrasound), or mechanically. The energy source is closely related to the time, pressure, and energy per molecule introduced into the system, and each of these parameters can have a strong influence on the metal-organic framework formed and its morphology.

[0051] The synthesis of conventional metal-organic frameworks is described in McDonald, T., Mason, J., Kong, X. et al, Cooperative insertion of CO2in diamine-appended metal-organic frameworks, Nature 519, 303-08 (2015), which is incorporated herein by reference. In general, 0.10 mmol of linker, 0.25 mmol of metal salt, and 10 mL of solvent, i.e., methanol / dimethylformamide (DMF), are placed together in a 20 mL glass scintillation vial. The vial is then sealed and placed in a 2 cm deep well plate on a hot plate at 393°K for approximately 12 hours. The metal-organic framework material is then decanted and the remaining powder is immersed three times in DMF and three times in methanol. The metal-organic framework is then collected by filtration and heated under dynamic vacuum (<10 μbar) at 523°K for 24 hours to completely desolvate. Using this particular methodology, approximately 0.073 mmol of metal-organic framework is obtained, or a 73% yield (comparing mmol of metal-organic framework produced to the initial mmol of linker), or a volume-normalized mass-based yield of 2.7 g MOF per liter of reaction solution.

[0052] In addition to the conventional synthesis described by McDonald, T. et al., Cooperative Insertion of CO2in Diamine-Appended Metal-Organic Frameworks, Nature, 519, 303-308, 2015 (incorporated herein by reference), other suitable syntheses for making metal-organic frameworks include those described in McDonald, T. et al., Capture of Carbon Dioxide from Air and Flue Gas in the Alkylamine Appended Metal-Organic Framework mmen-Mg2 (dobpdc), J. Am. Chem. Soc. 134, 7056-7065, 2012, Xiao, D. et al., Pore Environmental Effectors on Catalytic Cyclohexance Oxidation in Expanded Fe2(dobdc) Analogues, J. Am. Chem. Sci., 9, 160-174; 2018; U.S. Patent No. 8,653,292; and U.S. Patent Application Publication Nos. 2007 / 0202038, 2010 / 0307336, and 2016 / 0031920.

[0053] As provided herein, metal-organic frameworks are synthesized using a suspension of metal salts and organic ligands, and at least one solvent. The metal-organic frameworks are suspended as a solid phase in a liquid phase or dispersion, and are isolated and purified by filtration and washing steps. Depending on the particle size and other colloidal properties of the metal-organic framework, the filtration and washing steps can be time-consuming and inefficient, reducing the productivity of the synthesis and resulting in poor properties of the resulting metal-organic framework. In fact, the settling time required for these porous materials is often the bottleneck in many syntheses, second only to the washing steps.

[0054] Flocculation is the process by which colloids or dispersions break out of suspension in the form of flocs or flakes. There are different mechanisms for flocculation, but all generally increase the particle size of the material. Here we demonstrate for the first time that the addition of polymers to MOF suspensions to form flocs (larger aggregates of MOFs) can result in rapid settling (within minutes) and easy filtration of reaction or washing mixtures.

[0055] Flocculation is the aggregation of particles in a colloidal suspension caused by random collisions between suspended particles to form larger particles. Eventually particles large enough form that they separate due to density differences (creaming and settling). Colloidal suspensions are often long-lived because the particles do not clump together due to repulsion between like charges. Flocculation can be induced by the addition of flocculating agents such as electrolytes, which essentially neutralize the charged particles, after which flocculation occurs. Polymers provide significant van der Waals interactions due to their size.

[0056] Provided herein is a method for producing a metal-organic framework, the method comprising the steps of: (a) forming a suspension capable of producing a metal-organic framework; (b) inducing flocculation of the suspension to form a plurality of flocs; (c) separating the flocs from the suspension to produce a solid phase comprising the metal-organic framework and a supernatant liquid phase; (d) separating the solid phase from the supernatant liquid phase; and (e) recovering the metal-organic framework from the solid phase. In one embodiment, the method further comprises dissolving a metal salt and at least one ligand in a solvent to form a suspension.

[0057] In the method, flocculation is induced by the addition of a polymer solution. In one embodiment, the polymer solution comprises p(amic acid). In one embodiment, the suspension is agitated while inducing flocculation. In one embodiment, the polymer is added to the suspension in an amount between about 0.1% and 15% by weight based on the solid phase, or between 1% and 5% by weight based on the solid phase. The flocs are aggregates of the metal-organic framework particles. The flocs separate from the suspension and settle out of the suspension. In one embodiment, the solid phase is separated from the liquid phase by filtering the solid phase from the liquid phase. The metal-organic framework can be recovered as a solid phase by washing the metal-organic framework material with one or more solvents. In one embodiment, the metal-organic framework is recovered by washing the solid phase with DMF and methanol.

[0058] Also provided herein is a method for enhancing the settling rate of a metal-organic framework in a suspension, comprising the steps of: providing a suspension of the metal-organic framework; adding a flocculating agent to the suspension to form a plurality of flocs comprising aggregates of the metal-organic framework particles; and allowing the plurality of flocs to settle from the suspension to produce a metal-organic framework having approximately the same surface area as a metal-organic framework produced under the same process conditions but without the use of a flocculating agent.

[0059] Further provided herein is a method of producing a metal-organic framework, the method comprising: (a) preparing a metal-organic framework in a suspension; (b) adding a flocculant to the suspension to produce a plurality of aggregates of the metal-organic framework; (c) precipitating the plurality of aggregates of the metal-organic framework from the suspension to produce a solid phase comprising the metal-organic framework and a liquid phase; and (d) filtering the solid phase from the liquid phase to provide the metal-organic framework. The suspension comprises a plurality of solid reagents and at least one solvent. The solid reagents comprise at least one metal salt and at least one ligand. In one embodiment, the solid phase is washed with DMF and methanol. In one embodiment, the solid phase is washed with water or methanol or ethanol or a combination thereof.

[0060] In one embodiment, the method of the invention produces metal-organic frameworks comprising organic ligands comprising one or more of an alkyl group moiety having 1-10 carbon atoms; or an aryl group moiety having 1-5 aromatic rings; each of the one or more moieties having at least two X groups, where X is a functional group configured to coordinate to a metal or metalloid. In one embodiment, the method of the invention can produce metal-organic frameworks comprising organic ligands comprising an alkylamine moiety having 1-10 carbon atoms or an arylamine or nitrogen-containing heterocyclic moiety having 1-5 aromatic rings; and wherein each of the moieties has at least two X groups, where X is a functional group configured to coordinate to a metal or metalloid. In one embodiment, in any one of the examples, each X is selected from the group consisting of CO2H, OH, SH, OH2, NH2, CN, HCO, CS2H, NO2, SO3H, Si(OH)3, Ge(OH)3, Sn(OH)3, Si(SH)4, Ge(SH)4, Sn(SH)3, PO3H, AsO3H, AsO4H, P(SH)3, As(SH)3, CH(RSH)2, C(RSH)3, CH(RNH2)2, C(RNH2)3, CH(ROH ... and independently selected from the neutral or ionic forms of (ROH)3, CH(RCN)2, C(RCN)3, CH(SH)2, C(SH)3, CH(NH2)2, C(NH2)2, CH(OH)2, C(OH)3, CH(CN)2, C(CN)3, a nitrogen-containing heterocycle, a sulfur-containing heterocycle, or combinations thereof, where R is an alkyl group having 1 to 5 carbon atoms, or an aryl group having 1 to 2 phenyl rings.In one embodiment, the organic ligand is 1,3,5-benzenetricarboxylate, 1,4-benzenedicarboxylate, 1,3-benzenedicarboxylate, biphenyl-4,4'-dicarboxylate, benzene-1,3,5-tris(1H-tetrazole), acetylene-1,2-dicarboxylate, naphthalene dicarboxylate, adamantane tetracarboxylate, benzenetribenzoate, methane tetrabenzoate, adamantane tetrabenzoate, biphenyl-4,4'-dicarboxylate, imidazole, 2,5-dihydroxy-1,4-benzenedicarboxylic acid, 4,4'-dihydroxy-(1,1'-biphenyl)-3,3'-dicarboxylic acid, derivatives thereof, or combinations thereof.

[0061] Furthermore, the method of the present invention comprises the step of: 2+ , Mg 2+ , Ca 2+ , Sr 2+ , B.A. 2+ , Sc 3+ , Y 3+ , Ti 4+ , Zr 4+ , Hf 4+ , V 4+ , V 3+ , V 2+ , Nb 3+ , Ta 3+ , Cr 3+ , Mo 3+ , W 3+ , Mn 3+ , Mn 2+ , Re 3+ , Re 2+ , Fe 3+ , Fe 2+ , Ru 3+ , Ru 2+ , Os 3+ , Os 2+ , Co 3+ , Co 2+ , Rh 2+ , Rh + , Ir 2+ , Ir + , Pd 2+ , Pd + , Pt 2+ , Pt + , Cu 2+ , Cu+ , Ag + , Au + , Zn 2+ , Cd 2+ , Hg 2+ , Al 3+ , Ga 3+ , In 3+ , Tl 3+ , Si 4+ , Si 2+ , Ge 4+ , Ge 2+ , Sn 4+ , Sn 2+ , Pb 4+ , Pb 2+ , As 5+ , As 3+ , As + , Sb 5+ , Sb 3+ , Sb + , and Bi 5+ , Bi 3+ , Bi + or a combination thereof. In one embodiment, the metal ion is selected from Mg 2+ , Mn 3+ , Mn 2+ , Fe 3+ , Fe 2+ , Co 3+ , Co 2+ , Cu 2+ , Cu + , Pt 2+ , Ag + , Zn 2+ , Zr 4+ , Hf 4+ , or a combination thereof.

[0062] In one embodiment, the metal-organic framework is selected from Mg-MOF-74, UiO-66 and / or HKUST-1.

[0063] As described herein, the flocculating agent used in the method comprises a polymer. In one embodiment, the polymer is added to the suspension in an amount between about 1% and 13% by weight based on the solid phase. In one embodiment, the polymer is a p(amic acid). More specifically, the polymer solution comprises at least one polymer for inducing flocculation of the suspension of the metal-organic framework. The at least one polymer may comprise 0.1% or more (e.g., 0.1% or more, 0.2% or more, 0.3% or more, 0.4% or more, 0.5% or more, 0.6% or more, 0.7% or more, 0.8% or more, 0.9% or more, 1.0% or more, 1.1% or more, 1.2% or more, 1.3% or more, 1.4% or more, 1.5% or more, 1.6% or more, 1.7% or more, 1.8% or more, 1.9% or more, 2.0% or more, 2.1% or more, 2.2% or more, 2.3% or more, 2.4% or more, 2.5% or more, 2.6% or more, 2.7% or more, 2.8% or more, 2.9% or more, 3.0% or more, 3.1% or more, 3.2% or more, 3.3% or more, 3.4% or more, 3.5% or more, 3.6% or more, 3.7% or more, 3.8% or more, 3.9 ... 3% or more, 2.4% or more, 2.5% or more, 2.6% or more, 2.7% or more, 2.8% or more, 2.9% or more, 3.0% or more, 3.1% or more, 3.2% or more, 3.3% or more, 3.4% or more, 3.5% or more, 3.6% or more, 3.7% or more, 3.8% or more, 3.9% or more, 4.0% or more, 4.1% or more, 4.2% or more, 4.3% or more, 4.4% or more, 4.5% or more, 4.6% or more, 4.7% or more, 4.8% or more, 4.9% or more, or 5% or more) of the solution.

[0064] As described herein, the polymer may be present in an amount of 5% or less (e.g., 0.1% or less, 0.2% or less, 0.3% or less, 0.4% or less, 0.5% or less, 0.6% or less, 0.7% or less, 0.8% or less, 0.9% or less, 1.0% or less, 1.1% or less, 1.2% or less, 1.3% or less, 1.4% or less, 1.5% or less, 1.6% or less, 1.7% or less, 1.8% or less, 1.9% or less, 2.0% or less, 2.1% or less, 2.2% or less, 2.3% or less, 2.4% or less, 2.5% or less, 2.6% or less, 2.7% or less, 2.8% or less, 2.9% or less, 3.0% or less, 3.1% or less, 3.2% or less, 3.3% or less, 3.4% or less, 3.5% or less, 3.6% or less, 3.7% or less, 3.8% or less, 3.9 ... 7% or less, 2.8% or less, 2.9% or less, 3.0% or less, 3.1% or less, 3.3% or less, 3.4% or less, 3.5% or less, 3.6% or less, 3.7% or less, 3.8% or less, 3.9% or less, 4.0% or less, 4.1% or less, 4.2% or less, 4.3% or less, 4.4% or less, 4.5% or less, 4.6% or less, 4.7% or less, 4.8% or less, 4.9% or less).

[0065] The polymer is present in an amount of 0.5% to 15% by weight (e.g., 1.1% to 3.9%, 1.2% to 3.8%, 1.3% to 3.7%, 1.4% to 3.6%, 1.5% to 3.5%, 1.6% to 3.4%, 1.7% to 3.3%, 1.8% to 3.2%, 1.9% to 3.1%, or 2% to 3%) based on the total weight of the suspension. Generally, the polymer is present in an amount of about 0.1% to about 13.0% by weight based on the total weight of the solid phase.

[0066] The solvents used in the methods of the invention are capable of dissolving the reagents used in the MOF synthesis and providing a suspension of the resulting MOFs at room temperature and pressure. Suitable examples of solvents include, but are not limited to, non-polar solvents, polar aprotic solvents, polar protic solvents, water-miscible solvents, non-coordinating solvents, water, or combinations thereof. Exemplary solvents include, but are not limited to, acetaldehyde, acetic acid, acetone, acetonitrile, butanediol, butoxyethanol, butyric acid, diethanolamine, diethylenetriamine, dimethylacetamide (DMAc), dimethylformamide (DMF), dimethylformamide (DEF), dimethoxyethane, dimethylsulfoxide (DMSO), dioxane, ethanol, ethylamine, ethylene glycol, formic acid, furfuryl alcohol, glycerol, methanol, methyldiethanolamine, N-methyl-2-pyrrolidone ("NMP"), propanol, propanediol, propanoic acid, propylene glycol, pyridine, tetrahydrofuran ("THF"), triethylene glycol, dimethylhydrazine, hydrazine, pentane, cyclopentane, hexane, cyclohexane, benzene, toluene, chloroform, diethyl ether, dichloromethane, or combinations thereof.

[0067] Polymers, copolymers and / or classes of polymers useful for inducing flocculation in the method of making the metal-organic frameworks of the invention include polymers and / or copolymers including polyamides, polyacrylic acids, poly(meth)acrylic acids, polysaccharides including alginic acid, xanthan gum, polyamides, polyacrylamides, polyols, polyamines, polyimides, polyamic acids, and polyesters. The polymers may contain potentially charged groups (e.g., carboxylate, ammonium, amide, amic acid) that have different charge states depending on the pH of the solution and / or suspension. The polymers may contain aliphatic, aromatic, ether and ester backbone groups. Heteroatoms such as chlorine and fluorine may also be part of the polymer backbone. As described in the examples below, the polymer is added to the suspension as a polymer in solution.

[0068] Flocculation of the metal-organic framework in suspension allows for more rapid and efficient isolation (sedimentation of the metal-organic framework), recovery and purification (filtration and washing), increasing the space-time yield of the synthesis. In the method of the present invention, the metal-organic framework can be produced more rapidly by flocculating the metal-organic framework into aggregates using a polymer. The addition of one or more polymers to induce flocculation of the metal-organic framework causes the particles of the metal-organic framework to aggregate. The aggregates can be filtered and washed more efficiently than in the absence of the flocculating agent.

[0069] In the following examples, we first show that flocculation affects the efficiency and effectiveness of the production of metal-organic frameworks. The resulting solid phase can be washed with a solvent to remove excess unwanted material. Furthermore, the polymers shown below: (Formula I) TIFF2024520357000001.tif19162 (Formula II) A variety of polymers can be utilized in this method, including TIFF2024520357000002.tif28124. EXAMPLES

[0070] Features of the methods and compositions of the invention are described in the following non-limiting examples.

[0071] Example 1: Flocculation of Mg-MOF-74 In this example, Mg-MOF-74 successfully flocculated while retaining surface area. 2 g of Mg-MOF-74 powder was suspended in 18 g of N,N-dimethylformamide (DMF, 18 g) to produce a MOF suspension. Varying amounts of polymer in amino acid solution were added to the MOF suspension. In this example, an amic acid solution containing 3.8 wt% poly(amic acid) in DMF resulted in almost immediate visual aggregation of fine MOF particles. The MOF particles were allowed to settle, which was faster compared to the comparative example without added poly(amic acid). pXRD patterns were collected, and N2 isothermal measurements and surface area calculations were performed. The data are summarized in Table 1 and shown in Figure 1A and Figure 1B. TIFF2024520357000003.tif78153

[0072] Example 2: Flocculation of Mg-MOF-74 4.5 g of a 3.8 wt% solution of poly(amic acid) in DMF (Formula I) (0.171 g polymer, 4.7 wt% polymer solids relative to the theoretical amount of MOF solids) was added to a mixture of Mg-MOF-74 or 80 g of reaction mixture with a 55:45 ratio of N,N-dimethylformamide (DMF) and methanol (MeOH). The MOF wt% based on 100% yield was 4.55 wt% or 3.64 g. This resulted in immediate visual aggregation of fine MOF material.

[0073] The MOFs were allowed to settle, and the settling rate was faster, e.g., less than 2 minutes, compared to the control without added poly(amic anhydride). pXRD patterns were collected, and N2 isotherm measurements and surface area calculations were performed. The data are summarized in Table 2 below. TIFF2024520357000004.tif51154

[0074] Example 3: Various flocculants of Mg-MOF-74 To determine the extent of flocculation, multiple 5 g aliquots of the reaction mixture were taken into separate vials. The reaction mixture contained Mg-MOF-74 in 55:45 N,N-dimethylformamide (DMF):methanol (MeOH) (80 g reaction mixture, % MOF wt based on 100% yield equals 4.55 wt % equals 3.64 g). To each vial (5 g reaction mixture, 0.23 g theoretical MOF based on 4.55 wt % equals 100% yield) was added a 1 wt % solution of a potential flocculating agent. The potential flocculating agents and results are shown in Table 3 below. TIFF2024520357000005.tif130161

[0075] Figure 2A shows the pXRD patterns of Mg-MOF-74 without and with flocculation using poly(amic acid) washed without a large amount of MeOH, and Figure 2B shows the N2 isotherm measured at 77 K.

[0076] Example 4: Flocculation of UiO-66 with various polymers UiO-66 was synthesized in a mixture of N,N-dimethylformamide (DMF) and acetic acid ("AcOH"). After completion of the reaction, a filtration step is typically performed. Here, multiple 5 milliliter ("mL") aliquots were taken from the reaction mixture to demonstrate the benefits of flocculation. Different polymers were added to the 5 mL aliquots. Several polymers showed signs of flocculation. The polymers included commercially available poly(amic acid) and poly(acrylamide-co-acrylic acid) partial sodium salt. pXRD patterns were collected, and N2 isothermal measurements and surface area calculations were performed. The data are summarized in Table 4. TIFF2024520357000006.tif80169

[0077] Figure 3A shows the pXRD patterns of UiO-66 with and without flocculation, and Figure 3B shows the N2 isotherm measured at 77 K.

[0078] Example 5: Flocculation of UiO-66 with various polymers HKUST-1 powder (10 g) was suspended in 20 g of a 50–50 wt% mixture of ethanol to water. To determine the extent of flocculation, 5 mL aliquots were taken from the suspension and then diluted with 3 g of 50–50 wt% ethanol to water and placed in separate vials, except for p(amic acid), for which 3 g of extra g was not added. To each vial (8 g of mixture, 20.8 wt% MOF, which equates to 0.157 g), a 1 wt% solution of a potential flocculant was added. Several polymers showed positive signs of flocculation. These polymers included poly(amic acid) ("p(amic acid)"); Formula I), sodium alginate, xanthan gum, etc. pXRD patterns were collected and N2 isothermal measurements and surface area calculations were performed. As can be seen, there was some reduction in surface area due to flocculation. The data are summarized in Table 5. TIFF2024520357000007.tif64161

[0079] Figure 4A shows the pXRD patterns of HKUST-1 with and without flocculation, and Figure 4B shows the N2 isotherm measured at 77K.

[0080] The polymers tested in Example 5 include: Xantham Gum: Xantham Gum from Xanthomonas campestris, CAS No.=11138-66-2; Sodium Alginate: Alginic acid sodium salt, CAS No.=9005-38-3; Poly(N-isopropylacrylamide): Mn=85,000, CAS No.=25189-55-3; Polyacrylamide: Mn=150,000, CAS No.=9003-05-8; p(acrylamide-acrylic acid / Na): Poly(acrylamide-co-acrylic acid) partial sodium salt, Mw=520,000, Mn=150,000; Acrylamide~80 wt%, CAS No.=62649-23-4; Commercially available p(amic acid): Poly(pyromellitic dianhydride-co-4,4'-oxydianiline), amic acid solution. See Formula II above; Chitosan: high molecular weight, CAS No.=9012-76-4; p (amic acid), see Formula I above.

[0081] When numerical lower limits and numerical upper limits are described herein, ranges from any lower limit to any upper limit are contemplated. The present disclosure is described in terms of a specific embodiment, but is not so limited. Appropriate changes / modifications for operation under specific conditions should be obvious to those skilled in the art. Therefore, it is intended that the following claims be interpreted as covering all such changes / modifications that fall within the true spirit / scope of the present disclosure.

[0082] Additionally or alternatively, the present invention relates to:

[0083] EMBODIMENT 1 (a) forming a suspension capable of producing a metal-organic framework; (b) inducing flocculation of the suspension to form a plurality of flocs; (c) separating the flocs from the suspension to produce a solid phase comprising the metal-organic framework and a supernatant liquid phase; (d) separating the solid phase from the supernatant liquid phase; and (e) recovering the metal-organic framework from the solid phase. A method for producing a metal-organic framework comprising:

[0084] EMBODIMENT 2 2. The method of embodiment 1, further comprising dissolving the metal salt and the at least one ligand in at least one solvent to form a metal-organic framework suspension.

[0085] EMBODIMENT 3 3. The method of embodiment 1 or 2, wherein floc formation is induced by the addition of a polymer solution.

[0086] EMBODIMENT 4 4. The method of any one of the preceding embodiments, wherein the polymer solution comprises a poly(amic acid).

[0087] EMBODIMENT 5 5. The method of any one of the preceding claims, wherein the polymer is added to the suspension in an amount between about 0.1% and 13% by weight based on the solid phase.

[0088] EMBODIMENT 6 6. The method of any one of the preceding claims, wherein the flocs are aggregates of metal-organic framework particles or crystals.

[0089] EMBODIMENT 7 7. The method according to any one of the preceding embodiments, wherein the flocs are separated from the suspension by settling out of the suspension.

[0090] EMBODIMENT 8 8. The method according to any one of the preceding claims, wherein the solid phase is separated from the liquid phase by filtering or decanting the liquid phase from the solid phase.

[0091] EMBODIMENT 9 9. The method of any one of the preceding embodiments, wherein the metal-organic framework is recovered from the solid phase by washing the metal-organic framework material with one or more solvents.

[0092] EMBODIMENT 10 10. The method of any one of the preceding embodiments, wherein the metal-organic framework is recovered by washing the solid phase with DMF and methanol.

[0093] EMBODIMENT 11 11. The method according to any one of the preceding embodiments, wherein the suspension is agitated when inducing flocculation.

[0094] EMBODIMENT 12 12. The method according to any one of the preceding embodiments, wherein the suspension is not stirred when inducing flocculation.

[0095] EMBODIMENT 13 (a) providing a suspension of a metal-organic framework; (b) adding a flocculating agent to the suspension to form a plurality of flocs comprising aggregates of metal-organic framework particles; and (c) allowing the plurality of flocs to settle from the suspension to produce a metal-organic framework having approximately the same surface area as a metal-organic framework produced under the same process conditions but without the use of a flocculating agent. A method for enhancing the settling rate of a metal-organic framework in a suspension, comprising:

[0096] EMBODIMENT 14 14. The method of embodiment 13, wherein the flocculant comprises at least one soluble polymer comprising an amic acid group.

[0097] EMBODIMENT 15 (a) preparing a metal-organic framework in a suspension; (b) adding a flocculating agent to the suspension to produce a plurality of aggregates of the metal-organic framework; (c) allowing the plurality of aggregates of the metal-organic framework to settle from the suspension to produce a solid phase comprising the metal-organic framework and a liquid phase; and (d) filtering the solid phase from the liquid phase to provide the metal-organic framework. Including, A method for preparing a metal-organic framework, wherein the suspension comprises a plurality of solid reagents in at least one solvent, the solid reagents comprising at least one metal salt and at least one ligand.

[0098] EMBODIMENT 16 16. The method of embodiment 15, wherein the flocculating agent comprises a polymer.

[0099] EMBODIMENT 17 The method of embodiment 16, wherein the polymer is added to the suspension in an amount of about 0.1% to 13% by weight based on the solid phase.

[0100] EMBODIMENT 18 18. The method of embodiment 16 or 17, wherein the polymer comprises an amic acid group.

[0101] EMBODIMENT 19 19. The method according to any one of embodiments 15 to 18, wherein the solid phase is washed with DMF and methanol.

[0102] EMBODIMENT 20 20. The method of any one of the preceding claims, wherein the metal-organic framework is selected from Mg-MOF-74, UiO-66 and / or HKUST-1.

[0103] EMBODIMENT 21 the metal-organic framework comprising: an alkyl group moiety having 1 to 10 carbon atoms, or an aryl group moiety having 1 to 5 aromatic rings; and an organic ligand comprising one or more of: each of the one or more moieties has at least two X groups; 21. The method of any one of the preceding embodiments, wherein X is a functional group configured to coordinate to a metal or metalloid.

[0104] EMBODIMENT 22 22. The method of any one of the preceding claims, wherein the metal-organic framework comprises an organic ligand comprising an alkylamine moiety having 1-10 carbon atoms or an arylamine or nitrogen-containing heterocyclic moiety having 1-5 aromatic rings; and wherein one or more of the moieties each have at least two X groups; and wherein X is a functional group configured to coordinate to a metal or metalloid.

[0105] EMBODIMENT 23 Each X is independently CO2H, OH, SH, OH2, NH2, CN, HCO, CS2H, NO2, SO3H, Si(OH)3, Ge(OH)3, Sn(OH)3, Si(SH)4, Ge(SH)4, Sn(SH)3, PO3H, AsO3H, AsO4H, P(SH)3, As(SH)3, CH(RSH)2, C(RSH)3, CH(RNH2)2, C(RNH2)3, CH(ROH)2, C(ROH)3, CH(RCN)2 23. The method of claim 21 or 22, wherein the heterocyclic ring is selected from the neutral or ionic form of C(RCN)3, CH(SH)2, C(SH)3, CH(NH2)2, C(NH2)2, CH(OH)2, C(OH)3, CH(CN)2, C(CN)3, a nitrogen-containing heterocycle, a sulfur-containing heterocycle, or a combination thereof, where R is an alkyl group having 1 to 5 carbon atoms, or an aryl group having 1 to 2 phenyl rings.

[0106] EMBODIMENT 24 23. The method of embodiment 21 or 22, wherein the organic ligand is selected from 1,3,5-benzenetricarboxylate, 1,4-benzenedicarboxylate, 1,3-benzenedicarboxylate, biphenyl-4,4'-dicarboxylate, benzene-1,3,5-tris(1H-tetrazole), acetylene-1,2-dicarboxylate naphthalene dicarboxylate, adamantane tetracarboxylate, benzenetribenzoate, methane tetrabenzoate, adamantane tetrabenzoate, biphenyl-4,4'-dicarboxylate, imidazole, 2,5-dihydroxy-1,4-benzenedicarboxylic acid, 4,4'-dihydroxy-(1,1'-biphenyl)-3,3'-dicarboxylic acid, derivatives thereof, or combinations thereof.

[0107] EMBODIMENT 25 The metal-organic framework is Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ , B.A. 2+ , Sc 3+ , Y 3+ , Ti 4+ , Zr 4+ , Hf 4+ , V 4+ , V 3+ , V 2+ , Nb 3+ , Ta 3+ , Cr 3+ , Mo 3+ , W 3+ , Mn 3+ , Mn 2+ , Re 3+ , Re 2+ , Fe 3+ , Fe 2+ , Ru 3+ , Ru 2+ , Os 3+ , Ru 2+ , Os 3+ , Os 2+ , Co 3+ , Co 2+ , Rh 2+ , Rh + , Ir 2+ , Ir + , Pd 2+, Pd + , Pt 2+ , Pt + , Cu 2+ , Cu + , Ag + , Au + , Zn 2+ , Cd 2+ , Hg 2+ , Al 3+ , Ga 3+ , In 3+ , Tl 3+ , Si 4+ , Si 2+ , Ge 4+ , Ge 2+ , Sn 4+ , Sn 2+ , Pb 4+ , Pb 2+ , As 5+ , As 3+ , As + , Sb 5+ , Sb 3+ , Sb + , Bi 5+ , Bi 3+ , Bi + 25. The method of any one of the preceding claims, comprising a metal ion selected from:

[0108] EMBODIMENT 26 The metal ion is Mg 2+ , Mn 3+ , Mn 2+ , Fe 3+ , Fe 2+ , Co 3+ , Co 2+ , Cu 2+ , Cu + , Pt 2+ , Ag + , Zn 2+ , Zr 4+ , Hf 4+ or a combination thereof.

Claims

1. forming a suspension capable of producing a metal-organic framework; inducing flocculation of the suspension to form a plurality of flocs; separating the flocs from the suspension to produce a solid phase comprising the metal-organic framework and a supernatant liquid phase; Separating the solid phase from the supernatant liquid phase; and Process for recovering metal-organic frameworks from the solid phase - Patents.com A method for producing a metal-organic framework comprising:

2. 10. The method of claim 1, further comprising dissolving the metal salt and the at least one ligand in at least one solvent to form a metal-organic framework suspension.

3. 3. The method of claim 1 or 2, wherein floc formation is induced by the addition of a polymer solution, the polymer solution comprising a poly(amic acid).

4. The method of claim 3, wherein the polymer is added to the suspension in an amount between 0.1% and 13% by weight based on the solid phase.

5. The method of claim 1 or 2, wherein the flocs are aggregates of metal-organic framework particles or crystals.

6. 3. The method of claim 1 or 2, wherein the flocs separate from the suspension by settling out of the suspension.

7. 3. The method of claim 1 or 2, wherein the solid phase is separated from the liquid phase by filtering or decanting the liquid phase from the solid phase.

8. 3. The method of claim 1 or 2, wherein the metal-organic framework is recovered from the solid phase by washing the metal-organic framework material with one or more solvents, preferably the metal-organic framework is recovered by washing the solid phase with DMF and methanol.

9. preparing a metal-organic framework in a suspension; adding a flocculating agent to the suspension to produce a plurality of aggregates of the metal-organic framework; allowing the plurality of aggregates of the metal-organic framework to settle from the suspension to produce a solid phase comprising the metal-organic framework and a liquid phase; and filtering the solid phase from the liquid phase to provide a metal-organic framework. Including, 10. The method of claim 1, wherein the suspension comprises a plurality of solid reagents in at least one solvent, the solid reagents comprising at least one metal salt and at least one ligand.

10. The method of claim 9, wherein the solid phase is washed with DMF and methanol.

11. 10. The method of claim 1 or 9, wherein the metal-organic framework is selected from Mg-MOF-74, UiO-66 and / or HKUST-1.

12. the metal-organic framework comprising: an alkyl group moiety having 1 to 10 carbon atoms; or an aryl group moiety having 1 to 5 aromatic rings; and an organic ligand comprising one or more of: each of the one or more moieties has at least two X groups; 10. The method of claim 1 or 9, wherein X is a functional group configured to coordinate to a metal or metalloid.

13. 10. The method of claim 1 or 9, wherein the metal-organic framework comprises organic ligands comprising an alkylamine moiety having 1 to 10 carbon atoms or an arylamine or nitrogen-containing heterocyclic moiety having 1 to 5 aromatic rings; and wherein one or more of the moieties each have at least two X groups; and wherein X is a functional group configured to coordinate to a metal or metalloid.

14. Each X is independently CO ２ H, OH, SH, OH ２ , N.H. ２ ,CN,HCO,CS ２ H, NO ２ , S.O. ３ H, Si(OH) ３ , Ge(OH) ３ , Sn(OH) ３ , Si(SH) ４ , Ge(SH) ４ , Sn(SH) ３ , P.O. ３ H, AsO ３ H, AsO ４ H, P (SH) ３ , As(SH) ３ , CH(R.S.H.) ２ , C(R.S.H.) ３ , CH(RNH ２ ) ２ , C(RNH ２ ) ３ , CH(ROH) ２ , C(ROH) ３ , CH(RCN) ２ , C(RCN) ３ , CH(SH) ２ , C(SH) ３ , CH(NH ２ ) ２ , C(NH ２ ) ２ , CH(OH) ２ , C(OH) ３ , CH(CN) ２ , C(CN) ３ 13. The method of claim 12, wherein the heterocyclic ring is selected from the neutral or ionic form of a heterocyclic ring, a nitrogen-containing heterocyclic ring, a sulfur-containing heterocyclic ring, or a combination thereof, where R is an alkyl group having 1 to 5 carbon atoms, or an aryl group having 1 to 2 phenyl rings.

15. 13. The method of claim 12, wherein the organic ligand is selected from 1,3,5-benzenetricarboxylate, 1,4-benzenedicarboxylate, 1,3-benzenedicarboxylate, biphenyl-4,4'-dicarboxylate, benzene-1,3,5-tris(1H-tetrazole), acetylene-1,2-dicarboxylate naphthalene dicarboxylate, adamantane tetracarboxylate, benzenetribenzoate, methane tetrabenzoate, adamantane tetrabenzoate, biphenyl-4,4'-dicarboxylate, imidazole, 2,5-dihydroxy-1,4-benzenedicarboxylic acid, 4,4'-dihydroxy-(1,1'-biphenyl)-3,3'-dicarboxylic acid, derivatives thereof, or combinations thereof.

16. A metal-organic framework contains Be ２＋ , Mg ２＋ , Ca ２＋ , Sr ２＋ , Ba ２＋ , Sc ３＋ , Y ３＋ , Ti ４＋ , Zr ４＋ , Hf ４＋ , V ４＋ , V ３＋ , V ２＋ , Nb ３＋ , Ta ３＋ , Cr ３＋ , Mo ３＋ , W ３＋ , Mn ３＋ , Mn ２＋ , Re ３＋ , Re ２＋ , Fe ３＋ , Fe ２＋ , Ru ３＋ , Ru ２＋ , Os ３＋ , Ru ２＋ , Os ３＋ , Os ２＋ , Co ３＋ , Co ２＋ , Rh ２＋ , Rh ＋ , Ir ２＋ , Ir ＋ , Pd ２＋ , Pd ＋ , Pt ２＋ , Pt ＋ , Cu ２＋ , Cu ＋ , Ag ＋ , Au ＋ , Zn ２＋ , Cd ２＋ , Hg ２＋ , Al ３＋ , Ga ３＋ , In ３＋ , Tl ３＋ , Si ４＋ , Si ２＋ , Ge ４＋ , Ge ２＋ , Sn ４＋ , Sn ２＋ , Pb ４＋ , Pb ２＋ , As ５＋ , As ３＋ , As ＋ , Sb ５＋ , Sb ３＋ , Sb ＋ , Bi ５＋ , Bi ３＋ , Bi ＋ 10. The method of claim 1 or 9, comprising metal ions selected from Mg2+, Mn3+, Mn2+, Fe3+, Fe2+, Co3+, Co2+, Cu2+, Cu+, Pt2+, Ag+, Zn2+, Zr4+, Hf4+, or combinations thereof, preferably wherein the metal ions are selected from Mg2+, Mn3+, Mn2+, Fe3+, Fe2+, Co3+, Co2+, Cu2+, Cu+, Pt2+, Ag+, Zn2+, Zr4+, Hf4+, or combinations thereof.

17. The process of claim 17, comprising providing a suspension of a metal-organic framework; adding a flocculating agent to the suspension to form a plurality of flocs comprising aggregates of the metal-organic framework particles; and allowing the plurality of flocs to settle from suspension. The use of a polymer solution comprising a poly(amic acid) as a flocculant to enhance the settling rate of a metal-organic framework in suspension, comprising:

18. The use according to claim 17, wherein the metal-organic framework has approximately the same surface area as a metal-organic framework produced under the same process conditions but without the use of a flocculant.

19. The use according to claim 17 or 18, wherein the polymer is added to the suspension in an amount of 0.1% to 13% by weight, based on the solid phase.

20. The method of claim 17 or 18, wherein the metal-organic framework is selected from Mg-MOF-74, UiO-66 and / or HKUST-1. [Others] Claims 11 to 14 and 16 to 18 before the amendment have been deleted. The grounds for amending claims 1 to 20 of the present application after the amendment are briefly explained below. (Claim 1 and 2) No amendment, (Claim 3) Claims 3 and 4 before amendment, (Claim 4) Make claim 4 dependent only on claim 3, and delete "about." (Claim 5 to 7) are dependent on claim 1 or 2, (Claim 8) Claims 9 and 10 before amendment are dependent on claim 1 or 2, (Claim 9) Change "method for producing a metal-organic framework" to "method for producing a metal-organic framework" (Claim 10) Dependent only on claim 3, (Claim 11 to 13) Dependent on claim 1 or 9, (Claim 14-15) Dependent only on claim 12, (Claim 16) Claims 25 and 26 before amendment are dependent on claim 1 or 9, (Claim 17-18) Claims 13-14 before amendment and paragraph [0005] of the specification, (Claim 19) Claim 17 before amendment, (Claim 20) Claim 20 before amendment. (Underlining omitted.)

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