High-yield synthesis of metal-organic frameworks

Abstract

Metal-organic frameworks are synthesized from either a high-concentration synthesis method, in which the reaction solution contains elevated reagent concentrations, or a suspension of reagents exceeding their solubility limits in the reaction solution, in a high-solids synthesis method. In both approaches, the solubility of the reagents is maximized by including a buffer and fixing the nominal pH of the reaction solution to allow for the formation of the metal-organic framework. These methods improve the yield and scale-up of metal-organic frameworks.

Description

[Technical field]

[0001] The present invention relates to a method for synthesizing metal-organic frameworks. [Background technology]

[0002] Traditional synthetic methods for creating metal-organic frameworks involve the complete dissolution of solids in a solvent to form a reaction solution, which then drives the growth of the metal-organic framework at high temperatures. Often, a prerequisite for such synthetic methods is a large amount of solvent required to dissolve the reagents. However, for crystal growth, the amount of solid reagents required to create the metal-organic framework is often a limiting factor.

[0003] Conventional synthesis protocols have two major drawbacks: long reaction times and low yields. Although the yields obtained using conventional solvothermal methods are reasonable for laboratory use, on an industrial scale, the methods are inefficient in terms of time, solvent separation, and heating. Optimizing and scaling up the synthesis of metal-organic frameworks is a particular challenge due to the nature of the raw materials, as they often require large amounts of solvent and can incorporate small amounts of solids. This inevitably results in poor yields of material, making the process extremely intensive to produce enough material for testing. Summary of the Invention [Problem to be solved by the invention]

[0004] Thus, there is a need for methods of synthesizing metal-organic frameworks that produce higher yields of metal-organic frameworks with less effort than is typically required to obtain high quality metal-organic frameworks. [Means for solving the problem]

[0005] A method for making a metal-organic framework includes dissolving a plurality of solid reagents and a buffer in a solvent to provide a synthesis solution, and adding an amount of the plurality of solid reagents to the synthesis solution to generate a reaction solution that causes deprotonation of a linker and formation of the metal-organic framework. The solid reagents include at least one metal salt and at least one linker. The reaction solution has a reagent concentration that is about 3 to about 7 times that of conventional solvothermal synthesis methods.

[0006] Also provided is a method of making a metal-organic framework, comprising mixing an amount of a plurality of solid reagents and a buffer in a solvent to provide a reaction mixture. The solid reagents include at least one metal salt and at least one linker, and the amount of the plurality of solid reagents exceeds the amount that can be dissolved in the solvent. The reaction mixture is a saturated suspension, resulting in deprotonation of the linker and formation of the metal-organic framework. In one embodiment, the method further comprises increasing the amount of the solid reagent until the solid reagent is no longer soluble in the solvent.

[0007] Also provided is a method of synthesizing a metal-organic framework comprising mixing reagents including one or more metal salts and one or more linkers with a buffer in a solvent to produce a reaction mixture that is a saturated suspension. The reaction mixture is heated to form the metal-organic framework in about 3-fold to about 45-fold increased yield on a mass basis normalized to volume compared to conventional solvothermal synthesis of the same reagents.

[0008] Also provided is a method of synthesizing a metal-organic framework, comprising dissolving a plurality of solid reagents and a buffer in a solvent to provide a synthesis solution, and adding an amount of the plurality of solid reagents to the synthesis solution to produce a reaction solution having an amount of reagent concentration that is about 3-fold to about 7-fold greater than the amount of reagent concentration in a conventional solvothermal synthesis method. The solid reagents include at least one metal salt and at least one linker. The reaction solution results in deprotonation of the linker and formation of the metal-organic framework in a mass-based yield normalized for volume that is about 3-fold to about 15-fold greater than the yield of the metal-organic framework in a conventional solvothermal synthesis method of the same reagents.

[0009] In one embodiment, the reaction solution or mixture is static for about 96 hours.

[0010] In one embodiment, the reaction solution or mixture is stirred, tumbled, shaken, mixed or otherwise agitated at room temperature, ie, from about 18° C. to about 22° C. or above room temperature, for about 24 hours.

[0011] In one embodiment, the buffer comprises a Bronsted acid and its conjugate base or a Bronsted base and its conjugate acid. In one embodiment, the reaction solution or reaction mixture is heated at about 25°C to about 160°C.

[0012] In one embodiment, the reaction solution is subjected to a spontaneously determined pressurized pressure. In one embodiment, the linker comprises two or more phenyl rings or multiple bridged aryl species having two phenyl rings linked by vinyl or alkynyl groups. In one embodiment, the linker comprises H 4 DOBDPC. In one embodiment, the metal salt is prepared by neutralizing the acid or base of the metal ion. In one embodiment, the metal salt is Mg(NO 3 ) 2 6H 2 O and MnCl 2 4H 2O. In one embodiment, the buffer is Na MOPS. In one embodiment, the metal-organic framework comprises one or more metal ions of separate elements and a plurality of organic linkers, each organic linker being bound to one of the metal ions of two or more separate elements. In one embodiment, the metal-organic framework is MOF-274. In one embodiment, the nominal pH of the reaction solution allows for deprotonation of the linker. In one embodiment, the solvent comprises water, acetonitrile, and tetrahydrofuran. In one embodiment, the solvent is selected by evaluation of the Hansen solubility parameters. In one embodiment, the reaction solution is heated at static conditions. In one embodiment, the reaction solution is heated at about 120° C. In one embodiment, the metal-organic framework comprises about 25 mmol / g to about 40 mmol / g N at a relative pressure of about 0.1 to about 0.9. 2 In one embodiment, the metal-organic framework produces powder X-ray diffraction peaks at 2θ values ​​of about 4° to about 6° and about 7° to about 9°. In one embodiment, the metal-organic framework produces powder X-ray diffraction peaks at 2θ values ​​approximately equal to those of metal-organic frameworks produced by conventional synthesis methods.

[0013] In one embodiment, the metal-organic framework provides an X-ray diffraction pattern with a unit cell that can be assigned to a hexagonal unit cell. In one embodiment, the unit cell is selected from space groups 168-194 defined in the International Tables for Crystallography. In one embodiment, the metal-organic framework of the present invention further comprises a metal rod structure composed of face-sharing octahedra as identified by Schoedel, Li, Li, O'Keeffe, and Yaghi, Chem.Rev., 2016, 116, 12466-12535 and described as a helix by Lidin-Andersson. In one embodiment, the metal-organic framework has hexagonal pores oriented parallel to the metal rod structure. In one embodiment, the metal organic framework of the present invention exhibits a (3,5,7)-c msi net according to the method described in Schoedel, Li, Li, O'Keeffe, and Yaghi, Chem.Rev., 2016, 116, 12466-12535. In one embodiment, the metal organic framework exhibits a (3,5,7)-c msg net according to the method described in Schoedel, Li, Li, O'Keeffe, and Yaghi, Chem.Rev., 2016, 116, 12466-12535.

[0014] In one embodiment, the subject metal-organic framework can be prepared by heating at 250° C. 2 After drying under vacuum for 30 minutes, at 30° C., it exhibits the following peak maxima in the X-ray diffraction pattern:

[0015] [Table 1]

[0016] In one embodiment, the metal organic framework is N 2 After drying under vacuum for 30 minutes, at 30° C., it exhibits the following peak maxima in the X-ray diffraction pattern:

[0017] [Table 2]

[0018] In one embodiment, the A-axis of the unit cell and the B-axis of the unit cell are each greater than 18 Å, and the c-axis is greater than 6 Å. [Brief description of the drawings]

[0019] [Figure 1] 1 is a chart showing the increasing yield of Mg / Mn-MOF-274 with increasing amounts of reagents in the starting mixture. [Diagram 2] 1 shows powder X-ray diffraction data for MOF-274 prepared using conventional synthesis, high solids synthesis, and high concentration synthesis methods. [Figures 3A-3H] SEM images of metal-organic framework ("MOF") materials obtained from high solids synthesis, conventional solvothermal synthesis, high solids synthesis, and conventional solids synthesis methods, respectively, showing that the MOF materials have a rod shape, i.e., a morphology typical of MOF-274, regardless of synthesis method. [Figure 4] 1 is a plot of mmol / gram vs. P / PO showing N2 adsorption for MOF-274 synthesized under the following conditions: (a) a conventional synthesis method described in McDonald, T., Mason, J., Kong, X., et al, Cooperative insertion of CO2 in diamine-appended metal-organic frameworks, Nature, 519, 303-08 (2015) (incorporated herein by reference) using low reagent concentration in DMF / MeOH solvent; (b) low reagent concentration in water / THF / MeCN solvent; (c) a high concentration synthesis method in water / THF / MeCN solvent; and (d) a high solids synthesis method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] As described herein, metal-organic frameworks are synthesized from either: (1) a reaction solution containing an elevated concentration of reagents (herein referred to as "high concentration synthesis"), or (2) a suspension of reagents in the reaction solvent that exceeds their solubility limit (herein referred to as "high solids synthesis"). In either approach, a chemical buffer ("buffer") is present to maximize the solubility of the reagents and fix the nominal pH of the reaction solution to allow deprotonation of the linker and then formation of the metal-organic framework. These techniques can improve the yield and scale-up of metal-organic framework ("MOF") materials. Typically, conventional synthetic methods for making metal-organic frameworks have low yields of the final reaction products, which are therefore a challenge for scale-up, enhancement and commercialization. In this case, the scale-up of the creation of metal-organic frameworks is enhanced by increasing the amount of solid reagents available relative to the volume of solvent. It is essential that the quality of the metal-organic framework is not sacrificed by the scale-up process. As presented herein, several characterization methods have shown that the MOF materials obtained by the enhanced process yield the same materials with comparable or better physical properties, e.g., crystallinity and / or surface area.

[0021] Before the present method and apparatus 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., and as such may vary unless otherwise specified. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0022] For purposes of this disclosure, the following definitions apply:

[0023] As used herein, the articles "a," "an," and "the" should be understood to include the plural as well as the singular.

[0024] As used herein, the term "heteroatom" includes oxygen (O), nitrogen (N), sulfur (S) and silicon (Si), boron (B) and phosphorus (P).

[0025] The term "aryl", unless otherwise specified, refers to a single ring or a polyunsaturated aromatic substituent which may be fused or covalently bonded to each other. In one embodiment, the substituent has 1 to 11 rings, more particularly 1 to 3 rings. The term "heteroaryl" refers to an aryl substituent (or rings) containing 1 to 4 heteroatoms selected from N, O and S, where the nitrogen and sulfur atoms are optionally oxidized and the nitrogen atom is optionally quaternized. Representative heteroaryl groups are six-membered azines such as pyridinyl, diazinyl and triazinyl. Heteroaryl groups may be attached to the remainder of the molecule via 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, Soxazolyl, 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 structures are selected from the group of acceptable substituents described below.

[0026] As used herein, the terms "alkyl," "aryl," and "heteroaryl" can 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." These substituents are selected, for example, from groups that are attached to the heteroaryl or heteroarene nucleus through a carbon or heteroatom (e.g., P, N, O, S, Si, or B) and include, but are 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', -CO.sub.2R', -CONR'R'', -OC(O)NR'R'', -NR''C(O)R', -NR'-C(O)NR''R''', -NR''C(O).sub.2R', -NR-C(NR'R''R'').dbd.NR'''', -NR-C(NR'R'')=NR'''', -S(O)R', -S(O)R', -S(O)NR'R'', -NRSOR', -CN and -R', -, -CH(Ph), fluoro(C 1 ~C 4 ) alkoxy and fluoro(C 1 ~C 4 ) alkyl (where the number ranges from zero to the total number of open valences on the aromatic ring structure). Each of the above groups is directly bonded to the aryl or heteroaryl nucleus via a heteroatom (e.g., P, N, O, S, Si, or B), where R', R'', R''', and R'''' are preferably independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl. When a compound of the invention includes more than one R group, for example, each of the R groups is independently selected as are the R', R'', R''', and R'''' groups, respectively (when more than one of these groups are present).

[0027] The term “alkyl,” by itself or as part of another substituent, means, unless otherwise stated, linear, branched, or cyclic hydrocarbon radicals, or combinations thereof, which may be fully saturated, unsaturated, or polyunsaturated, and have the specified number of carbon atoms (i.e., C 1 ~C 10 means 1 to 10 carbons). Examples of saturated hydrocarbon groups include, but are not limited to, the following groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl, cyclohexyl, (cyclohexyl)methyl, cyclopropylmethyl, and homologs and isomers such as n-pentyl, n-hexyl, n-heptyl, n-octyl, and the like. An "unsaturated alkyl group" is one having 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 the higher homologs and isomers. The term "alkyl," unless otherwise noted, is also meant to optionally include those derivatives of alkyl defined in more detail below, such as "heteroalkyl."

[0028] The term "heteroalkyl", by itself or in combination with another term, means, unless otherwise stated, a stable linear or branched or cyclic hydrocarbon radical, or combination thereof, consisting of the indicated number of carbon atoms and at least one heteroatom selected from the group consisting of O, N, Si and S, where the nitrogen and sulfur atoms may be optionally oxidized and the nitrogen heteroatom may be optionally quaternized. The heteroatoms O, N, S and Si can be present at any position within the heteroalkyl group or at the position at which the alkyl group is attached to the remainder of the molecule. Examples include, but are not limited to, the following: -CH 2 -CH 2 -O-CH 3 , -CH 2-CH 2 -NH-CH 3 , -CH 2 -CH 2 -N(CH 3 )-CH 3 , -CH 2 -S-CH 2 -CH 3 , -CH 2 -CH 2 , -S(O)-CH 3 , -CH 2 -CH 2 -S(O) 2 -CH 3 , -CH=CH-O-CH 3 , -Si(CH 3 ) 3 , -CH 2 -CH=N-OCH 3 and -CH=CH-N(CH 3 )-CH 3 Up to two heteroatoms may be, for example, -CH 2 -NH-OCH 3 and -CH 2 -O-Si(CH 3 ) 3 Similarly, the term "heteroalkylene" by itself or as part of another substituent refers to a divalent radical derived from heteroalkyl, e.g., -CH 2 -CH 2 -S-CH 2 -CH 2 - and -CH 2 -S-CH 2 -CH 2 -NH-CH 2 - is intended to mean, but is not limited to, -. For heteroalkylene groups, heteroatoms can occupy either or both ends of the chain (e.g., alkyleneoxy, alkylenedioxy, alkyleneamino, alkylenediamino, and the like). Additionally, for alkylene and heteroalkylene linking groups, no direction is implied as to the orientation of the linking group when writing the formula of the linking group. For example, a group of the formula -CO 2 R'-- represents both -C(O)OR' and -OC(O)R'.

[0029] As used herein, the term "ligand" refers to a molecule that contains one or more substituents capable of functioning as a Lewis base (electron donor). In one embodiment, the ligand can be oxygen, phosphorus, or sulfur. In one embodiment, the ligand can be a single amine or multiple amines containing 1-10 amine groups.

[0030] The terms "halo" or "halogen," by themselves or as part of another substituent, mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom.

[0031] The symbol "R" is a general abbreviation that represents a substituent, which is selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted heterocycloalkyl groups.

[0032] As used herein, the term "Periodic Table" means the Periodic Table of the Elements of the International Union of Pure and Applied Chemistry (IUPAC) (December 2015).

[0033] The term "salt" includes salts of compounds prepared by neutralizing an acid or base, depending on the particular ligand or substituents found on the compounds described herein. When compounds of the present invention have relatively acidic functionalities, base addition salts can be obtained in neutral form by contacting such compounds with a sufficient amount of the desired base, either neat or in a suitable inert solvent. Examples of base addition salts include: sodium, potassium, calcium, ammonium, organic amino or magnesium salts or similar salts. Examples of acid addition salts include those derived from inorganic acids such as hydrochloric acid, bromic acid, nitric acid, carboxylic acid, monohydrogen carboxylic acid, phosphoric acid, monohydrogen phosphoric acid, dihydrogen phosphoric acid, sulfuric acid, monohydrogen sulfuric acid, hydroiodic acid, or phosphorous acid, as well as 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 functional groups, and therefore the compounds can be converted into either base or acid addition salts. Hydrates of the salts are also included.

[0034] For any compound described herein having one or more chiral centers, unless the absolute stereochemistry is specified, it is to be understood that each center can independently be in either the R-configuration or the S-configuration or a mixture thereof. Thus, the compounds provided herein can be enantiomerically pure or can be stereoisomeric mixtures. In addition, for any compound described herein having one or more double bonds that form geometric isomers that can be defined as E or Z, it is to be understood that each double bond can independently be E or Z or a mixture thereof. Similarly, it is to be understood that any compound described is intended to include all tautomeric forms.

[0035] In addition, 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.

[0036] As used herein, a "metal organic framework" may be a mixed metal organic framework or metal-organic framework or a mixed metal mixed organic framework as described in U.S. Patent Application Serial No. 62 / 839,261.

[0037] Conventional synthesis method Traditionally, metal-organic frameworks are prepared by reacting pre-synthesized or commercially available linkers with metal ions. In another approach (called "in situ linker synthesis"), a specific organic linker(s) can be generated in situ from starting materials in the reaction medium.

[0038] In the synthesis of metal-organic frameworks, organic molecules are used not only as structural directing agents but also as reactants that are incorporated as part of the structure of the framework. With this in mind, conventional synthesis methods generally employ high reaction temperatures. Solvothermal reaction conditions, structural directing agent methods, mineralizer methods, and even microwave-assisted synthesis or steam-assisted conversion methods have recently been introduced.

[0039] As described herein, conventional synthesis methods are typically applied reactions carried out by conventional electrical heating and do not include any parallel reactions. In conventional synthesis methods, the reaction temperature is the main parameter for the synthesis of metal-organic frameworks, and two temperature ranges are usually distinguished, solvothermal and non-solvothermal, which represent the type of reaction set conditions used. Solvothermal reactions are generally carried out in a closed vessel, near the boiling point of the solvent used, under a pressure that is determined automatically. Non-solvothermal reactions are carried out under ambient pressure, below or at the boiling point, simplifying the requirements of the synthesis. Non-solvothermal reactions can be further classified as room temperature or high temperature.

[0040] Conventional synthesis of metal-organic frameworks is carried out in a solvent at temperatures ranging from room temperature to approximately 250° C. Heat is transferred by convection from a heat source oven. Alternatively, energy can be applied by electrical potential, electromagnetic radiation, mechanical waves (ultrasound) or mechanically. The energy source is closely related to the length of time, pressure and energy per molecule introduced into the system, each of these parameters can have a strong effect on the metal-organic framework formed and its morphology.

[0041] Conventional synthesis methods for metal-organic frameworks are described in the following literature: McDonald, T., Mason, J., Kong, X., et al., Cooperative insertion of CO 2in diamine-appended metal-organic frameworks, Nature, 519, 303-08 (2015) (hereby incorporated by reference). Typically, 0.10 mmol of linker, 0.25 mmol of metal salt and 10 mL of solvent, i.e., methanol / dimethylformamide (DMF), are mixed together in a 20 mL glass scintillation vial. The vial is then sealed and placed on a heating plate at 393°K in a 2 cm deep well plate for about 12 hours, after which a powder forms on the bottom and walls of the vial. The metal-organic framework material is then decanted and the remaining powder is immersed three times in DMF and then 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 remove the solvent. Using this particular technique, the conventional synthesis method yields approximately 0.073 mmol of metal-organic framework, i.e., a volume-normalized mass yield of 73% (comparing mmol of metal-organic framework produced to initial mmol of linker), i.e., 2.7 grams of MOF per liter of reaction solution.

[0042] In addition to the conventional synthetic methods described in Nature, 2015, 519, 303-308, which are incorporated herein by reference, synthetic methods for making metal-organic frameworks are further described in J. Am. Chem. Soc., 2012, 134, 7056-7065; Chem. Sci., 2018, 9, 160-174; U.S. Pat. No. 8,653,292 and U.S. Patent Application Publication Nos. 2007 / 0202038, 2010 / 0307336, and 2016 / 0031920.

[0043] Methods herein for making metal-organic frameworks Provided herein are methods of making metal-organic frameworks, in which either high concentrations of solid reagents are combined to provide a reaction solution having an amount of reagent concentration about 3-7 times greater than that used in conventional solvothermal synthesis methods, and / or the reaction mixture is saturated with solid reagents and / or is a suspension. Either method results in the formation of a metal-organic framework. As used herein, the term "solid reagent" refers to a combination of one or more metal salts and one or more organic linkers ("linkers"). In one embodiment, the organic linker comprises a molecule having multiple bridged aryl species, such as two or more phenyl rings or two phenyl rings linked by, for example, a vinyl or alkynyl group.

[0044] In the high concentration synthesis method, the buffer is present at a higher concentration to increase the solubility of the solid reagent in the synthesis solution, resulting in improved yield. More specifically, in the synthesis solution, a metal salt, one or more linkers and a buffer are dissolved in a solvent to obtain a synthesis solution having a reagent concentration. Additional solid reagents (metal salts and linkers) are then added to the synthesis solution to increase the reagent concentration to obtain a reaction solution. As provided herein, by applying this technique, the volume-normalized mass-based yield in the synthesis of MOF-274 can be increased by 15 times compared to the approach set forth in Nature, 2015, 519, 303-308.

[0045] In high solids synthesis, the reagent solids are well dispersed in the reaction mixture but not completely dissolved. More specifically, the amount of solid reagents (molten salts and linkers) is greater than the amount that can be dissolved to saturate the reaction solution. In this technique, the amount of solid reagents is increased so that they no longer dissolve in the reaction solution and a suspension is formed.

[0046] In both the high-concentration and high-solids synthesis methods, increasing the reagent concentration by up to 7-fold compared to conventional synthesis methods (Nature, 2015, 519, 303-308) can increase the mass yield ("yield") by up to about 35-fold when normalized by the volume of solvent used in the synthesis. Furthermore, both approaches increase the amount of MOFs prepared (yield) while maintaining or reducing the solvent volume and reactor size, making them suitable for potential scale-up applications.

[0047] In one embodiment, the high concentration synthesis method includes a method of making a metal-organic framework comprising combining one or more metal salts and one or more linkers in a buffer and dissolving the solid reagents in a solvent to obtain a synthesis solution. Additional metal salts and linkers are dispersed in the synthesis solution to obtain a reaction solution. The reaction solution is then sealed and heated by one of a variety of methods. In one embodiment, the cumulative concentration of the one or more metal salts is in an amount of about 25 mM to about 100 mM and the one or more linkers is in an amount of about 10 mM to about 40 mM. In one embodiment, the buffer concentration is about 100 mM to about 260 mM. In one embodiment, the reaction solution has a reaction concentration of the solid reagents of about 135 mM to about 400 mM. In one embodiment, the method of the present invention may have a mass-based, volume-normalized yield of metal-organic framework of about 2 to about 15 mg per mL of solvent.

[0048] In one embodiment, in the high solid content synthesis method, the solid reagent can have a concentration about 5 to about 35 times higher than the concentration of the solid reagent in the conventional synthesis method. In one embodiment, the one or more metal salts are in an amount of about 175 mM to about 867 mM, and the one or more linkers are in an amount of about 85 mM to about 361 mM. In one embodiment, the buffer concentration is about 270 mM to about 1.624 M. In one embodiment, the reaction solution has a reaction concentration of the solid reagent of about 530 mM to about 2.852 M.

[0049] The method of the present invention provides mass-based, volume-normalized yields of metal-organic frameworks that are about 10 to about 40 times, or about 14 to about 35 times, higher than mass-based, volume-normalized yields of conventional synthetic methods.

[0050] As described herein, the metal salt has the formula MX 2 For example, M=Mg, Mn, X 2 =(Oac) 2 , (HCO 3 ) 2 , (F 3 CCO 2 ) 2 , (acac) 2 , (F 6 acac) 2 , (NO 3 ) 2 , S.O. 4 ;M=Ni,X 2 =(Oac) 2 , (NO 3 ) 2 , S.O. 4 ;M=Zn, X 2 +(Oac) 2 , (NO 3 ) 2 In one embodiment, the metal salt can be in the form of a crystal or a crystalline powder. In one embodiment, the metal salt is, for example, Mg(NO 3 ) 2 6H 2 O and MnCl 2 4H 2 It is O.

[0051] As described herein, metal-organic frameworks are porous crystalline materials formed of one or more different metal cations, clusters or chains linked by two or more multitopic (polytopic) organic linkers. In one embodiment, the metal-organic framework is Mg / Mn-MOF-274 (sometimes referred to as MOF-274).

[0052] As described herein, a suitable linker can be formed by two phenyl rings linked at the 1,1' carbons with a carboxylic acid on the 3,3' carbons and an alcohol on the 4,4' carbons. The positions of the carboxylic acid and alcohol can also be switched (e.g., "pc-H 4 "DOBPDC" or "pc-MOF-274"), there is no change in the topology of the metal-organic framework. In one embodiment, the linker is H 4 DOBDPC.

[0053] Solvents useful in the methods of the present invention include, for example, water, acetonitrile, and tetrahydrofuran. More specifically, the solvent is about 20 to about 30% by volume water, about 35 to about 40% by volume acetonitrile, and about 35 to about 40% by volume tetrahydrofuran. Optionally, the solvent can be selected by evaluation of the Hansen solubility parameters.

[0054] Metal organic frameworks can be synthesized at room temperature or by conventional electrical heating, microwave heating, electrochemical, mechanochemical and ultrasonic methods. Conventional step-by-step and even high-throughput methods can be employed as well. However, in any synthesis method, conditions must be established to produce the desired inorganic building blocks without decomposing the organic linker. At the same time, the crystallization kinetics must allow nucleation and growth of the desired phase to occur.

[0055] The heating and sealing step may include heating the reaction solution under static conditions for about 96 hours. The heating and sealing step may include heating the reaction solution under dynamic (e.g., stirring, shaking, mixing, agitation) conditions for about 24 hours. The heating and sealing step may include heating the reaction solution in a static oven at about 120° C. The heating and sealing step may include heating the reaction solution in a rotating oven at about 150° C. The heating may be performed without sealing to synthesize the MOF under solvent reflux conditions at approximately 1 bar pressure. In one embodiment, the reaction solution is typically heated at 50° C. to 175° C. (or 100° C. to 160° C. or 115° C. to 145° C.) for 1 hour to 7 days, or 6 hours to 5 days, or 12 hours to 3 days. The reaction solution may be centrifuged or filtered to obtain the metal-organic framework and washed.

[0056] The methods of the present invention are advantageous because they reduce the cost and effort required to obtain high quality MOFs. Because they require less time and can synthesize more material, they can also make more material available for testing and characterization, significantly reducing the time required, which can have a significant effect on costs. Thus, this new method represents a process enhancement for MOF synthesis.

[0057] It is essential that the scale-up process does not compromise the quality of the MOFs. Several characterization techniques (detailed below) show that the novel methods disclosed herein yield MOFs of comparable or superior quality compared to traditional synthetic methods.

[0058] Metals and metal salts The metal organic framework comprises cations, clusters or chains of two or more different metals linked by two or more polytopic organic linkers. In one embodiment, the metal organic framework produced by the method of the present invention comprises one or more separate elements independently selected from the group of Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu and Zn. In one embodiment, each of the one or more separate elements is a metal, more specifically Mg, Mn, Ni or Zn.

[0059] More specifically, the metal of the metal-organic framework of the present invention can be one of the elements of groups IIA, IIIB, IVB, VB, VIB, VIIB, VIII, IB and IIB of the 4th period and group IIA of the 3rd period of the periodic table, namely Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu and Zn. Furthermore, the metal-organic framework can contain two or more separate elements, as well as any combination of multiple metals, and theoretically can be any combination of M. 1 x M 2 y ...M n z (A)(B) 2 |x+y+c+z=2, and M 1 ≠M 2 ≠...≠M n where x, y, and z are each independent values ​​between 0.0 and 2.0.

[0060] The metal can be a monovalent metal, which will form a protonated form of the linker. For example, the metal can be Na +or one from group 1. Furthermore, the metal can be one of two or more divalent cations ("divalent metals") or trivalent cations ("trivalent metals"). In one embodiment, the metal-organic framework includes a metal that can be in an oxidation state other than +2 (i.e., more than just divalent, trivalent, tetravalent...). The framework can have metals that include a mixture of different oxidation states. Examples of mixtures include Fe(II) and Fe(III), Cu(II) and Cu(I), and / or Mn(II) and Mn(III). More specifically, a trivalent metal is a metal that has an oxidation state of +3. Some metals used to form the metal-organic framework, particularly Fe and Mn, can adopt an oxidation state of +2 (divalent) or +3 (trivalent) under relatively mild conditions (Chem. Mater., 2017, 29, 6181). Similarly, Cu(II) can form Cu(I) under mild conditions. Therefore, any minor change to the oxidation state of any metal and / or selective change in the oxidation state of the metal can be used to improve the metal-organic framework of the present invention. 1 , C 2 ...C n Finally, all of the above variations can be combined, such as with multiple valence metals (two or more different metals) and multiple charge-balancing molecular fragments.

[0061] In the method of the invention, the metal is reacted with a divalent first row transition metal salt, MX, as described herein. 2 For example, M=Mg, Mn;X 2 =(Oac) 2 , (HCO 3 ) 2 , (F 3 CCO 2 ) 2 , (acac) 2 , (F 6 acac) 2 , (NO 3 ) 2 MX, e.g. M=Mg, Mn; X=SO 4 , CO 3 ;M=Ni,X 2=(Oac) 2 , (NO 3 ) 2 , S.O. 4 ;M=Zn, X 2 +(Oac) 2 , (NO 3 ) 2 It is possible to provide it as Examples of metals (M) suitable for use in the metal salts include, but are not limited to, lanthanum, cerium, praseodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, aluminum, gallium, indium, magnesium, calcium, strontium, barium, iron, niobium, scandium, yttrium, zirconium, titanium, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, lutetium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, lawrencium, rutherfordium, dubnium, seaborgium, bohrium, hassium, meitnerium, darmstadtium, roentgenium, and the like. Other sources of metals include metal oxides, metal hydroxides, metal sulfides, metal chalcogenides, pure metals or any combination of metal sources.

[0062] Examples of counterions in metal salts include, but are not limited to, nitrates, nitrites, phosphates, phosphites, sulfates, sulfites, fluorides, chlorides, bromides, iodides, acetates, carbonates, etc. Any metal can be in the form of any salt, selected based on the ability of the metal salt (metal / counterion combination) to dissolve in the solvent. Metal salts can be hydrates, alcoholates, or acetonates.

[0063] As described herein, metal organic frameworks are synthesized by mixing or otherwise combining metal salts and organic linkers. Suitable metal ions include metals and metalloids in a variety of coordination structures and oxidation states. In one embodiment, MOFs are produced using metal ions with distinct coordination structures in combination with ligands with multidentate functional groups and suitable templating agents. One metal ion that favors octahedral coordination is cobalt(II). One metal ion that favors tetrahedral coordination is zinc(II). MOFs can be made 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+ , Cd2+ , 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 + , B.E. 2+ as well as the counterions of the corresponding metal salts.

[0064] 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 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+ and the corresponding metal salt counterions. In one embodiment, metal ions for use in the preparation of MOFs 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 + and the corresponding metal salt counterions. In one embodiment, the metal ions for use in the preparation of MOFs are selected from the group consisting of: 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 counterions of the corresponding metal salts.

[0065] In general, metal salts include various salts of compounds prepared by neutralizing an acid or base, depending on the particular substituents found on the compound. When a compound has a relatively acidic functionality, a base addition salt can be obtained in neutral form by contacting 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, potassium, calcium, ammonium, organic amino or magnesium salts or similar salts. Examples of acid addition salts include those derived from inorganic acids such as hydrochloric acid, bromic acid, nitric acid, carboxylic acid, monohydrogen carboxylic acid, phosphoric acid, monohydrogen phosphoric acid, dihydrogen phosphoric acid, sulfuric acid, monohydrogen sulfuric acid, hydroiodic acid, or phosphorous acid, as well as 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 can contain both basic and acidic functional groups, and thus the compounds can be converted into either base or acid addition salts. Hydrates of the salts are included as well.

[0066] Linker Suitable organic linkers (also referred to herein as "linkers") can be determined from the structure of the metal-organic framework and the symmetry operations associated with the portion of the organic linker that binds to the metal node of the metal-organic framework. Ligands are chemically and / or structurally distinct and can be used to link the metal node-binding region of the metal-organic framework to a C 2 Note that it is possible to relate the symmetry axes.

[0067] In one embodiment, the linker is [ka] (In the formula, R 1 is R 1 ' and R 2 is R 2 '') may include.

[0068] Exemplary linkers include: [ka] where R is any molecular fragment. Includes.

[0069] Additional examples of organic linkers include para-carboxylates ("pc-linkers"), such as 4,4'-dioxidobiphenyl-3,3'-dicarboxylate (DOBPDC); 4,4''-dioxido-[1,1':4',1''-terphenyl]-3,3''-dicarboxylate (DOTPDC); and dioxidobiphenyl-4,4'-dicarboxylate (para-carboxylate-DOBPDC (also called PC-DOBPDC), as well as the following compounds: [ka]

[0070] In one embodiment, the organic linker has the formula: [ka] (In the formula, R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 and R 20 are each independently selected from H, halogen, hydroxyl, methyl, and halogen-substituted methyl. has.

[0071] In one embodiment, the organic linker has the formula: [ka] (In the formula, R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are each independently selected from H, halogen, hydroxyl, methyl, and halogen-substituted methyl. has.

[0072] In one embodiment, the organic linker has the formula: [ka] (In the formula, R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are each independently selected from H, halogen, hydroxyl, methyl or halogen-substituted methyl, and R 17 is selected from substituted or unsubstituted aryl, vinyl, alkynyl, and substituted or unsubstituted heteroaryl. having

[0073] In one embodiment, the organic linker has the formula: [ka] (In the formula, R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are each independently selected from H, halogen, hydroxyl, methyl, or halogen-substituted methyl. has.

[0074] Here, R 11 , R 12 , R 13 , R 14 , R 15 and R16 are each independently selected from H, halogen, hydroxyl, methyl or halogen-substituted methyl, and R 17 is selected from substituted or unsubstituted aryl, vinyl, alkynyl, and substituted or unsubstituted heteroaryl.

[0075] Examples of linkers include, but are not limited to, 4,5-dicyanoimidazole, substituted 4,5-dicyanoimidazole, oxalic acid, ethyl oxalate, fumaric acid, 1,3,5-benzenetribenzoic acid (BTB), DCPB, benzenetribiphenyl carboxylic acid (BBC), 5,15-bis(4-carboxyphenyl)zinc(II) porphyrin (BCPP), 1,4-benzenedicarboxylic acid (BDC), 2-amino-1,4-benzenedicarboxylic acid (R 3 -BDC or H 2 N BDC), 1,1'-azo-diphenyl 4,4'-dicarboxylic acid, cyclobutyl-1,4-benzenedicarboxylic acid (R 6 -BDC), benzenetricarboxylic acid, 2,6-naphthalenedicarboxylic acid (NDC), 1,1'-biphenyl 4,4'-dicarboxylic acid (BPDC), 2,2'-bipyridyl-5,5'-dicarboxylic acid, adamantanetetracarboxylic acid (ATC), adamantanedibenzoic acid (ADB), dihydroxyterephthalic acid (DHBDC), biphenyltetracarboxylic acid (BPTC), tetrahydropyrene 2,7-dicarboxylic acid (HPDC), dihydroxyterephthalic acid (DHBC), pyrene 2,7-dicarboxylic acid (PDC), pyrazinedicarboxylic acid, acetylenedicarboxylic acid (ADC), camphordicarboxylic acid, fumaric acid, benzenetetracarboxylic acid, 1,4-bis(4-carboxyphenyl)butadiyne, nicotinic acid and terphenyldicarboxylic acid (TPDC), 2,5-dihydroxy-1,4-benzene-dicarboxylic acid (H 4 DOBDC), 4,4'-dihydroxybiphenyl-3,3'-dicarboxylic acid (H 4 DOBPDC), 4,4''-dihydroxy-[1,1':4',1''-terphenyl]-3,3''-dicarboxylic acid (H 4substituted derivatives of the above mentioned linkers, such as 3,3'-dihydroxybiphenyl-4,4'-dicarboxylic acid (pc-DOBPDC), 3,3'-dihydroxybiphenyl-4,4'-dicarboxylic acid (pc-DOBPDC), and the like, as well as combinations of all of the above.

[0076] Linker H 4 DOBPDC or 4,4'-dihydroxy-(1,1'-biphenyl)-3,3'-dicarboxylic acid is an organic linker compound, which can be synthesized according to Lindsey, A.S.; Jeskey, H., Chem. Rev., 1957, 57(4), 583-620 (hereby incorporated by reference) or can be obtained commercially.

[0077] Chemical Buffers In any of the above methods, a chemical buffer (herein referred to as a "buffer") is present to maximize the solubility of the reagents by fixing the nominal pH of the reaction solution to allow for deprotonation of the linker and subsequent formation of the metal organic framework. The buffer may include an acid and its conjugate base or a base and its conjugate acid. The buffer may be generated in situ by adding a buffered acid followed by a basic solution to achieve the appropriate pH. Similarly, the buffer may be generated in situ by adding a buffered base followed by an acidic solution to achieve the appropriate pH. In one embodiment, the buffer may be 3-(N-morpholino)propanesulfonic acid ("MOPS") or Na MOPS.

[0078] Examples of suitable bases include, but are not limited to, piperazine, 1,4-dimethylpiperazine, sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonium hydroxide, and the like, and any combination thereof.

[0079] Examples of suitable acids include, but are not limited to, hydrochloric acid, nitric acid, citric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, acetic acid, perchloric acid, phosphoric acid, phosphorus-containing acids, sulfuric acid, formic acid, hydrofluoric acid, and the like, and any combination thereof.

[0080] Examples of suitable acids and conjugate bases and suitable bases and conjugate acids used to buffer at a nominal pH include, but are not limited to, acetic acid / acetate, citric acid / citrate, boric acid / borate, etc., buffers known as "good buffers" as defined in Biochemistry, 1966, 5, 467-477 (incorporated herein by reference), and non-complexing tertiary amine buffers known as "better buffers" as defined in Anal. Chem., 1999, 71, 3140-3144 (incorporated herein by reference).

[0081] Buffers may also include potential variants of MOPS, having the formula: [ka] (In the formula, n is an integer of 1 to 10, and R 1 and R 7 Any atom bridging the two may be functionalized with a chemical substituent or is "R" as defined in paragraphs

[0027] to

[0030] ,

[0032] and

[0033] above; R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are each independently C, O, N or S; and R 7 is any Bronsted acid functional group or the corresponding conjugate base, sulfonic acid, phosphonic acid and / or sulfonate, phosphonate, phosphate, hydroxyl, ammonia, or sulfate. It may be of the following type.

[0082] solvent Examples of solvents that can be used in the methods of the present invention, either alone or as a mixture of solvents, include, but are not limited to, acetone, acetonitrile, benzyl alcohol, 1-butanol, 2-butanol, n-butyl acetate, cyclohexane, cyclohexanol, cyclohexanone, diacetone alcohol, 1,4-dioxane, methanol, ethanol, ethyl acetate, ethylbenzene, ethyl lactate, ethylene carbonate, ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, gamma-butyrolactone (GBL), heptane, hexane, n-propanol, iso-propanol, n-butanol. , iso-butanol, t-butanol, iso-propyl acetate, isophorone, d-limonene, methyl acetate, methyl ethyl ketone, N-methyl-2-pyrrolidone (NMP), methylene chloride, 1-nitropropane, n-propyl acetate, propylene carbonate, water, dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), water, N,N-dimethylformamide (DMF), N,N-dimethylacetamide, 1,3-dimethylpropyleneurea, hexamethylphosphoramide, dimethyl ether, diethyl ether, methyl ethyl ether, pentane, benzene, cyclohexane, n-hexane, n-octane, kerosene, dodecane, methylcyclohexane, toluene, etc.

[0083] The Hansen solubility parameter can be derived from the Hildenbrand solubility parameter, which relates solubility to the square root of the cohesive energy density. The drawback of defining solubility as a single parameter, as presented by Hildenbrand, is that it does not account for intermolecular associations, such as those resulting from polar or hydrogen-bonding interactions. In contrast, the Hansen solubility parameter is premised on the understanding that the total evaporation energy, and hence the total cohesive energy, has several independent components arising from atomic dispersion forces, dipole-dipole forces between permanent dipoles, and hydrogen bonding. Thus, the Hansen solubility parameter is typically expressed in MPa. 0.5 There are three Hansen solubility parameters, measured in units of:D ), the energy from dipolar intramolecular forces between molecules (the polar parameter or δ P ) and the energy from hydrogen bonds between molecules (hydrogen bond parameter or δ H (also called Hansen Solubility Parameters). Substances with similar Hansen Solubility Parameters have a high affinity for each other, and the magnitude of the similarity determines the magnitude of the interaction. Thus, Hansen Solubility Parameters provide a more quantitative means of understanding the adage "like dissolves like" and are often used to predict whether a first substance will dissolve in a second substance to form a solution. See Hansen Solubility Parameters: A User's Handbook, Charles M. Hansen, CRC Press, Boca Raton, FL. (2007, 2nd ed.).

[0084] Hansen solubility parameters for certain solvents and solvates (e.g., acetone, methanol, dimethyl sulfoxide (DMSO), toluene, cyclohexane, etc.) are commercially available in the HSPiP database or in Hansen Solubility Parameters: A User's Handbook, Charles M. Hansen, CRC Press, Boca Raton, FL. (2007, 2nd ed.). Hansen solubility parameters for new molecules can also be experimentally determined by dispersing the molecule in a series of solvents with known Hansen solubility parameters. Once it is known which solvents will dissolve the molecule, the Hansen solubility parameters for those solvents can be plotted using Cartesian coordinates, assigning each parameter to its own axis, resulting in a solubility sphere, also called the "Hansen space". The center of the solubility sphere defines the experimental Hansen solubility parameter for the molecule. Additionally, Hansen solubility parameters for solvent mixtures can be calculated by volume-weighting and averaging the Hansen solubility parameters for each component in the mixture. In one embodiment, the solvent is selected by evaluation of the Hansen Solubility Parameters.

[0085] As a non-limiting example, a metal-organic framework can be synthesized by dissolving one or more metal salts together with one or more linkers in a solvent at a molar ratio of 0.2:1 to 5:1 (or 0.6:1 to 3:1, or 0.8:1 to 2:1, or 1:1) of total metal salts to total linkers to form a reaction solution.

[0086] As described in the following examples, metal-organic frameworks were prepared and then characterized by conventional methods and the novel methods described herein. EXAMPLES

[0087] Example 1 Metal-organic frameworks were synthesized by three methods: conventional synthesis, high-concentration synthesis, and high-solids synthesis. Metal-organic frameworks were synthesized from either 1) solutions with elevated reagent concentrations, or 2) suspensions saturated with the reagents, which exceed their solubility limits in the reaction solvent. In both approaches, the solubility of the reagents is maximized by the inclusion of a buffer and fixing the nominal pH of the reaction solution to allow deprotonation of the linker and subsequent formation of the metal-organic framework. Both approaches improve the yield and scale-up of the MOF materials. It is essential that the scale-up process does not sacrifice the quality of the MOFs. Several characterization techniques show that the MOF materials obtained by the enhanced process give the same material.

[0088] Conventional synthesis method The general protocol for synthesizing MOF-274 is from Nature, 2015, 519, 303-308. Add 27.4 mg to 41.1 mg (0.1-0.15 mmol) of linker H. 4 DOBPDC was combined with 0.25-0.375 mmol of metal salt and dissolved in 10 mL of the mixed solvent. The solution was sealed in a 20 mL scintillation vial and heated at 120° C. for 12 h, and the solid was collected and washed. Materials were obtained in yields ranging from 23.3 to 54.1 mg.

[0089] High concentration synthesis method To prepare Mg / Mn-MOF-274 in a high-concentration solid reagent, 0.75 mmol of H 4 DOBPDC, 1.68 mmol Mg(NO 3 ) 2 6H 2 0, 0.19 mmol MnCl 2 4H 2 2H2O and 7.5 mmol of buffer Na2O, MOPS were dissolved in 75 mL of solvent (made of 0.25:0.37:0.38 water:acetonitrile:tetrahydrofuran). Once all solids were completely dissolved, an additional 3 mmol of H2O was added. 4 DOBPDC, 6.72 mmol Mg(NO 3 )2 6H 2 0, 0.76 mmol MnCl 2 4H 2 O and 12 mmol of Na MOPS were added to the system. The reaction solution was transferred into a 125 mL Teflon-lined Parr autoclave, sealed, and heated at 120 °C for 96 h under static conditions. Mg / Mn-MOF-274 was obtained with a yield of 1.08 g.

[0090] High solid content synthesis method To obtain a higher yield of Mg / Mn-MOF-274, the metal-organic framework was prepared under high solids conditions. 4 DOBPDC, 11.696 mmol of Mg(NO 3 ) 2 6H 2 0, 1.300 mmol MnCl 2 4H 2 O and 24.4 mmol of Na MOPS buffer were mixed in 15 mL of solvent (made of 0.25:0.37:0.38 water:acetonitrile:tetrahydrofuran) to thoroughly disperse all solids. Note that these reagents do not completely dissolve in the reaction solution. The reaction solution was transferred into a 23 mL Teflon-lined Parr autoclave, which was sealed and placed in a tumbling oven at 150 °C for 24 h. Mg / Mn-MOF-274 was obtained in a yield of 3.6 g.

[0091] A summary of the different synthesis methods, the conventional synthesis method, the high concentration synthesis method, and the high solid content synthesis method, as described above, is shown in Table 1 below.

[0092] [Table 3]

[0093] As seen in Table 1, increasing the reagent concentration by 35-fold compared to the literature synthesis method resulted in an almost 45-fold increase in mass yield when normalized to the volume of solvent used in the synthesis method. The mass (yield) of the metal-organic framework MOF-274 as a function of each synthesis method is shown in Figure 1. Importantly, despite increasing the solid reagent content beyond the point where all solids are completely dissolved in the reaction solution (saturated suspension), the quality of the material is not sacrificed as can be seen in Figures 2, 3 and 4.

[0094] Powder X-ray diffraction patterns confirmed that the same level of material was prepared using a synthesis method with higher solids:solvent ratios and higher solids:solvent concentrations versus conventional solids (prepared by conventional synthesis methods, as well as benign solvents) as seen in Figure 2. No amines were added to these metal-organic frameworks, and they were not functionalized or activated.

[0095] Powder X-ray diffraction ("PXRD") data further revealed comparable material crystallinity, which was supported by SEM images showing persistent rod-shaped morphology with the formation of discrete crystallites (Figure 3). Surface area measurements indicate that the high concentration and high solids synthesis methods yielded metal-organic frameworks with comparable surface areas compared to the conventional synthesis method. The SEM images provided a quantitative assessment of the bulk material shape, morphology, and polydispersity of the materials. Images were taken on a Hitachi SEM using a top detector at 2 keV acceleration.

[0096] As can be seen in Figure 4, N 2 Adsorption isotherms confirmed that the MOFs prepared by the high-concentration synthesis method and the high-solids synthesis method had similar surface areas to those prepared by the conventional synthesis method. Specifically, the N adsorption isotherms of MOF-274 synthesized under literature conditions (low concentration in DMF / MeOH), low concentration in water / THF / MeCN, high concentration in water / THF / MeCN, and high solids synthesis method in water / THF / MeCN were 2The metal-organic frameworks prepared by the high-concentration synthesis method and the high-solid content synthesis method showed N adsorption of about 25 mmol / g to about 40 mmol / g at a relative pressure of about 0.1 to about 0.9. 2 showed absorption.

[0097] In summary, the metal-organic frameworks were characterized to analyze the similarity between those prepared by the conventional synthesis method and the high-concentration and high-solid content synthesis methods. Despite increasing the reagent content beyond the point where all solids dissolve in the reaction solution, the quality of the material was not sacrificed, as can be seen in Figures 2-4. As can be seen in Figure 2, the powder X-ray diffraction data also confirmed that the high-concentration and high-solid content synthesis methods produced the same level of material compared to the conventional synthesis method. Specifically, the metal-organic frameworks prepared by the high-concentration and high-solid content synthesis methods exhibit powder X-ray diffraction peaks at 2θ values ​​of about 4° to about 6° and about 7° to about 9°, which are similar to those of the metal-organic frameworks prepared by the conventional synthesis method. The powder X-ray diffraction data in Figure 2 also reveals a similar degree of material crystallinity, which is further supported by the scanning electron microscope images in Figure 3. Scanning electron microscope images in Figure 3 show that, regardless of the synthesis method, the resulting materials are rod-shaped, a morphology typical of MOF-274. In Figure 3, the images in each row correspond to the same sample taken at different magnifications. As shown, the metal-organic frameworks prepared by the high-concentration and high-solids synthesis methods exhibited comparable crystallinity compared to metal-organic frameworks made using conventional synthesis methods.

[0098] Certain features have been described using a set of upper numerical limits and a set of lower numerical limits. Ranges from any lower limit to any upper limit are to be understood as being contemplated unless otherwise noted. Certain lower limits, upper limits and ranges appear in one or more claims below. All numerical values ​​account for experimental error and variations that would be expected by one of ordinary skill in the art.

[0099] Various terms are defined above. If a term used in the claims is not defined above, one of ordinary skill in the relevant art should give that term the broadest definition given to it as reflected in at least one of the published publications or issued patents. Moreover, all patents, test procedures, and other literature cited in this application are incorporated by reference in their entirety to the extent such disclosures are not inconsistent with this application and for all jurisdictions where such incorporation is permitted.

[0100] The foregoing description of the present disclosure illustrates and describes the techniques of the present invention. In addition, while the present disclosure shows and describes representative methods, it is to be understood that any other combinations, modifications, and environments may be employed, and that the methods of the present invention may be altered or modified in accordance with the teachings set forth above and / or the skill or knowledge of the relevant art, within the scope of the concepts expressed herein. Preferred aspects of the present disclosure are as follows. [1] 1. A method of making a metal-organic framework, comprising: dissolving a plurality of solid reagents and a buffer in a solvent to provide a synthesis solution, the solid reagents including at least one metal salt and at least one linker; adding a quantity of a plurality of solid reagents to the synthesis solution to generate a reaction solution having a quantity of reagent concentration, the reagent concentration of the reaction solution being about 3 to about 7 times the amount of the reagent concentration in a conventional solvothermal synthesis method; The method includes: [2] 1. A method of making a metal-organic framework, comprising: mixing an amount of a plurality of solid reagents and a buffer in a solvent to prepare a reaction mixture, the solid reagents including at least one metal salt and at least one linker, and the amount of the plurality of solid reagents exceeds the amount that can be dissolved by the solvent at about 18° C. to about 22° C., and the reaction mixture is a saturated suspension; The method includes: [3] The method of claim 2, further comprising increasing the amount of the solid reagent until the solid reagent is no longer soluble in the solution. [4] 1. A method for synthesizing a metal-organic framework, comprising: mixing a reagent comprising one or more metal salts and one or more linkers with a buffer in a solvent to form a reaction solution, the reaction solution being a saturated suspension at about 18° C. to about 22° C.; heating the reaction mixture to form the metal-organic framework; The method includes: [5] The method for preparing a metal-organic framework according to any one of [1] to [4], wherein the reaction solution is not in a static state for about 24 to about 96 hours. [6] The method for preparing a metal-organic framework according to any one of [1] to [5], wherein the buffer contains a Brønsted acid and a conjugate base thereof, or a Brønsted base and a conjugate acid thereof. [7] The method for preparing a metal-organic framework according to any one of [1] to [6], wherein the reaction solution or reaction mixture is heated at about 100°C to about 160°C. [8] The method for preparing a metal-organic framework according to any one of [1] to [7], wherein the linker comprises two or more phenyl rings or a multi-bridged aryl species having two phenyl rings linked by a vinyl group or an alkynyl group. [9] The linker is H 4 The method for preparing the metal-organic framework according to any one of [1] to [8], wherein the metal-organic framework is DOBPDC.

[10] The method for preparing a metal-organic framework according to any one of [1] to [9], wherein the metal salt is prepared by neutralizing an acid or a base of a metal ion.

[11] The metal salt is Mg(NO 3 ) 2 ·6H 2 O and MnCl 2 ·4H 2 The method for producing a metal-organic framework according to any one of [1] to

[10] , wherein O is O.

[12] The method for preparing a metal-organic framework according to any one of [1] to

[11] , wherein the buffer is essentially of the family comprising morpholine and sulfonic acids bridged by alkyl groups.

[13] The method for preparing a metal-organic framework according to any one of [1] to

[12] , wherein the buffer is from the family of sodium carbonate or sodium bicarbonate.

[14] The buffer is MOPS, NaMOPS or NaHCO 3 The method for producing the metal-organic framework according to any one of [1] to

[13] ,

[15] The metal-organic framework has the formula: 1 x M 2 (2-x) (A) (where M 1 and M 2 is a metal cation, x ranges from 0 to 2, and A is a disalicylate organic linker.

[16] A is,

change

[14] . The mixed metal-organic framework according to

[14] , wherein the linkers are independently selected from the group consisting of:

[17]

[16] A mixed metal-organic framework according to

[16] , which exhibits an X-ray diffraction pattern that can be assigned to a hexagonal unit cell.

[18] The mixed metal-organic framework according to

[17] , wherein the unit cell is selected from space groups 168 to 194.

[19] The mixed metal-organic framework according to any one of

[16] to

[18] , further comprising metal rod structures formed from face-sharing octahedrons.

[20] A mixed metal-organic framework according to

[19] , having hexagonal pores oriented parallel to the metal rod structures.

[21] The mixed metal-organic framework according to any one of

[16] to

[20] , which exhibits a (3,5,7)-c msi network.

[22] The method for producing a metal-organic framework according to any one of [1] to

[15] , wherein the metal-organic framework is MOF-274.

[23] The method according to any one of [1] to

[15] or

[22] , wherein the nominal pH of the reaction solution allows for deprotonation of the linker.

[24] The method for preparing a metal-organic framework according to any one of [1] to

[15] ,

[22] or

[23] , wherein a solvent comprises water, acetonitrile and tetrahydrofuran.

[25] The method for preparing a metal-organic framework according to any one of [1] to

[15] or

[22] to

[24] , wherein the solvent is selected by evaluation of the Hansen solubility parameter.

[26] The method for preparing a metal-organic framework according to any one of [1] to

[15] or

[22] to

[25] , wherein the reaction solution or reaction mixture is heated under static, tumbling or stirring conditions.

[27] The method according to any one of [1] to

[15] or

[22] to

[26] , wherein the reaction solution or reaction mixture is heated at about 120°C.

[28] The method according to any one of [1] to

[15] or

[22] to

[27] , wherein the reaction solution or reaction mixture is heated at about 150°C.

[29] The metal-organic framework exhibits a N concentration of about 25 mmol / g to about 40 mmol / g at a relative pressure of about 0.1 to about 0.9. 2 The method according to any one of [1] to

[15] or

[22] to

[28] , wherein the absorption

[30] The method according to any one of [1] to

[15] or

[22] to

[29] , wherein the metal-organic framework produces powder X-ray diffraction peaks at 2θ values ​​of about 4° to about 6° and about 7° to about 9°.

[31] The method according to any one of [1] to

[15] or

[22] to

[30] , wherein the metal-organic framework produces powder X-ray diffraction peaks at 2θ values ​​equal to those of metal-organic frameworks produced by conventional synthetic methods.

Claims

1. A method for preparing a synthesis solution by dissolving a plurality of solid reagents and a buffer in a solvent, the solid reagents including at least one metal salt and at least one linker; adding a quantity of a plurality of solid reagents to the synthesis solution to generate a reaction solution having a reaction concentration of the solid reagents between 135 mM and 400 mM; 1. A method for making a metal-organic framework, comprising: The metal organic framework has the formula: M 1 x M 2 (2-x) (A) where M 1 and M 2 are metal cations, x ranges from 0 to 2, and A is a disalicylate organic linker. is shown in The metal includes at least one of Mg, Mn, Ni, and Zn; The buffer comprises a Brønsted acid and its conjugate base or a Brønsted base and its conjugate acid, and The method wherein the solvent comprises water, acetonitrile and tetrahydrofuran.

2. A step of preparing a reaction mixture by mixing in a solvent an amount of a plurality of solid reagents and a buffer, the solid reagents including at least one metal salt and at least one linker, and the amount of the plurality of solid reagents exceeds the amount that can be dissolved by the solvent at 18°C ​​to 22°C, the reaction mixture being a saturated suspension.

1. A method for making a metal-organic framework, comprising: The metal organic framework has the formula: M 1 x M 2 (2-x) (A) where M 1 and M 2 are metal cations, x ranges from 0 to 2, and A is a disalicylate organic linker. is shown in The metal includes at least one of Mg, Mn, Ni, and Zn; The buffer comprises a Brønsted acid and its conjugate base or a Brønsted base and its conjugate acid, and The method wherein the solvent comprises water, acetonitrile and tetrahydrofuran.

3. The method of claim 2, further comprising the step of increasing the amount of solid reagent until the solid reagent is no longer soluble in the solution.

4. The method of claim 2, wherein the reaction mixture has a reaction concentration of the solid reagent of 530 mM to 2.852 M.

5. A method for preparing the metal-organic framework of claim 1, wherein the reaction solution or mixture is not in a static state for 24 to 96 hours.

6. A method for preparing the metal-organic framework of claim 1, wherein the reaction solution or mixture is heated at 100° C. to 160° C.

7. A method for preparing a metal-organic framework as described in claim 1 or 2, wherein the linker comprises two or more phenyl rings or multiple bridged aryl species having two phenyl rings linked by a vinyl group or an alkynyl group.

8. The linker is selected from the group consisting of 4,4'-dioxidobiphenyl-3,3'-dicarboxylate (DOBPDC), 4,4''-dioxido-[1,1':4',1''-terphenyl]-3,3''-dicarboxylate (DOTPDC), dioxidobiphenyl-4,4'-dicarboxylate (para-carboxylate-DOBPDC) and the following compounds: 【Chemistry 1】 A method for making the metal-organic framework of claim 1 or 2, comprising at least one para-carboxylate ("pc-linker") selected from the group consisting of:

9. The linker is H ４ A method for preparing the metal-organic framework of claim 1 or 2, which is DOBPDC.

10. 3. The method of making the metal-organic framework according to claim 1 or 2, wherein the metal salt is prepared by neutralizing an acid or a base of a metal ion.

11. The method of making the metal-organic framework of claim 1 or 2, wherein the counter ion in the metal salt comprises nitrate, nitrite, phosphate, phosphite, sulfate, sulfite, fluoride, chloride, bromide, iodide, acetate and / or carbonate.

12. The metal salt is Mg(NO ３ ) ２ ・6H ２ O and MnCl ２ ・4H ２ 3. The method for producing the metal-organic framework according to claim 1 or 2, wherein 13. A method for preparing a metal-organic framework according to claim 1 or 2, wherein the buffer is essentially of the family comprising morpholine and sulfonic acids bridged by alkyl groups.

14. A method for preparing a metal-organic framework according to claim 1 or 2, wherein the buffer is from the sodium carbonate or sodium bicarbonate family.

15. The buffer is 3-(N-morpholino)propanesulfonic acid (MOPS), NaMOPS or NaHCO ３ 3. The method for producing the metal-organic framework according to claim 1 or 2, 16. The method for preparing the metal-organic framework of claim 1 or 2, wherein the metal-organic framework is MOF-274.

17. A method for making a metal-organic framework according to claim 1 or 2, wherein the nominal pH of the reaction solution allows for deprotonation of the linker.

18. A method for preparing a metal-organic framework according to claim 1 or 2, wherein the solvent is selected by evaluation of the Hansen solubility parameters.

19. A method for preparing the metal-organic framework of claim 1 or 2, wherein the reaction solution or mixture is heated under static, tumbling or stirring conditions.

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