High yield synthesis of metal-organic frameworks

Abstract

This invention relates to the synthesis of metal-organic frameworks (MOFs) from high-concentration synthesis in which the reaction solution contains increased reagent concentrations, or from reagent suspensions exceeding their solubility limits in the reaction solvent in high-solids-content synthesis. In both methods, the solubility of the reagents is maximized by including a buffer that fixes the nominal pH of the reaction solution to achieve MOF formation. These methods improve the yield and scalability of MOFs.

Description

Technical Field

[0001] This invention relates to a method for synthesizing metal-organic frameworks. Background Technology

[0002] Traditional synthesis for the fabrication of metal-organic frameworks involves completely dissolving a solid in a solvent to form a reaction solution, followed by enhanced growth of the metal-organic framework at elevated temperatures. A necessary condition for this synthesis is typically a large amount of solvent required to dissolve the reagent. However, for crystal growth, the amount of solid reagent required to fabricate the metal-organic framework is often a limiting factor.

[0003] Traditional synthetic methods suffer from two main drawbacks: long reaction times and low yields. While the yields obtained using conventional solvothermal methods are reasonable for laboratory use, these methods are inefficient on an industrial scale due to time, solvent separation, and heating requirements. Optimizing and scaling up metal-organic framework synthesis is particularly challenging due to the nature of the materials, as they typically require large amounts of solvent and can accommodate small amounts of solids. This naturally leads to poor material yields and extremely intensive processes to produce enough material for testing.

[0004] Therefore, there is a need for metal-organic framework synthesis that yields higher quantities of metal-organic frameworks with less labor compared to what is typically required to obtain high-quality metal-organic frameworks. Summary of the Invention

[0005] A method for manufacturing a metal-organic framework includes the following steps: dissolving a plurality of solid reagents and a buffer in a solvent to provide a synthesis solution, and adding a certain amount of the plurality of solid reagents to the synthesis solution to generate a reaction solution that induces deprotonation of the linker and formation of the metal-organic framework. The solid reagents comprise at least one metal salt and at least one linker. The reagent concentration of the reaction solution is approximately 3 to approximately 7 times that of reagents used in conventional solvothermal synthesis.

[0006] A method for manufacturing a metal-organic framework is also provided, comprising the step of mixing a plurality of solid reagents and a buffer in a solvent to provide a reaction mixture. The solid reagents comprise at least one metal salt and at least one linker, and the amount of the plurality of solid reagents exceeds the amount soluble in the solvent. The reaction mixture is a saturated suspension and causes deprotonation of the linker and formation of the metal-organic framework. In one aspect, the method further comprises the step of increasing the amount of solid reagents until the solid reagents are no longer soluble in the solvent.

[0007] A further method for synthesizing metal-organic frameworks is provided, comprising the step of mixing a reagent containing one or more metal salts and one or more linkers with a buffer in a solvent to produce a reaction mixture as a saturated suspension. The reaction mixture is then heated to form a significantly larger quantity of metal-organic framework compared to conventional solvothermal synthesis with the same reagents, said significantly larger quantity being approximately 3 to approximately 45 times the volume-normalized mass-based yield.

[0008] A method for synthesizing metal-organic frameworks is also provided, comprising the steps of: 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 a reagent concentration of approximately 3 to approximately 7 times that of conventional solvothermal synthesis. The solid reagents comprise at least one metal salt and at least one linker. The reaction solution causes deprotonation of the linker and formation of a metal-organic framework in an amount approximately 3 to approximately 15 times the volume-normalized mass-based yield of a metal-organic framework obtained by conventional solvothermal synthesis using the same reagents.

[0009] In one respect, the reaction solution or reaction mixture stands for approximately 96 hours.

[0010] In one respect, the reaction solution or reaction mixture is stirred, turned, shaken, mixed or otherwise agitated for about 24 hours at room temperature or between about 18°C ​​and about 22°C, or at temperatures above room temperature.

[0011] In one aspect, the buffer comprises a Brønsted acid and its conjugate base, or a Brønsted base and its conjugate acid. In another aspect, the reaction solution or reaction mixture is heated between about 25°C and about 160°C.

[0012] In one aspect, the reaction solution is subjected to autogenous pressurization. In one aspect, the linker comprises a polybridged aryl class having two or more phenyl rings or two phenyl rings linked by vinyl or alkynyl groups. In one aspect, the linker is H4DOBDPC. In one aspect, the metal salt is prepared by neutralization of the metal ion with an acid or base. In one aspect, the metal salt is Mg(NO3)2·6H2O and MnCl2·4H2O. In one aspect, the buffer is Na MOPS. In one aspect, the metal-organic framework comprises one or more metal ions of different elements and multiple organic linkers, wherein each organic linker is linked to one of two or more metal ions of different elements. In one aspect, the metal-organic framework is MOF-274. In one aspect, the nominal pH of the reaction solution allows for deprotonation of the linker. In one aspect, the solvent comprises water, acetonitrile, and tetrahydrofuran. In one aspect, the solvent is selected by evaluating the Hansen solubility parameter. In one aspect, the reaction solution is heated under static conditions. In one aspect, the reaction solution is heated at approximately 120°C. In one aspect, the metal-organic framework exhibits N2 absorption between approximately 25 mmol / g and approximately 40 mmol / g at a relative pressure between approximately 0.1 and approximately 0.9. In another aspect, the metal-organic framework produces powder X-ray diffraction peaks at 2θ values ​​between approximately 4° and approximately 6° and between approximately 7° and approximately 9°. In yet another aspect, the metal-organic framework produces powder X-ray diffraction peaks at 2θ values ​​substantially equivalent to those of metal-organic frameworks prepared by conventional synthesis.

[0013] In one aspect, the metal-organic framework provides an X-ray diffraction pattern of a unit cell indexable to a hexagonal unit cell. In one aspect, the unit cell is selected from space groups 168 to 194 as defined in International Tables for Crystallography. In one aspect, the metal-organic framework of the present invention further comprises a metal rod structure composed of coplanar octahedra, as described by the Lidin-Andersson spiral as determined by Schoedel, Li, Li, O'Keeffe and Yaghi, Chem Rev. 2016 116, 12466-12535. In one aspect, the metal-organic framework has hexagonal holes parallel to the orientation of the metal rod structure. In one aspect, according to the method described in Schoedel, Li, Li, O'Keeffe and Yaghi, Chem Rev. 2016 116, 12466-12535, the metal-organic framework of the present invention exhibits a (3,5,7)-c msi network. In one respect, according to the method described by Schoedel, Li, Li, O'Keeffe and Yaghi, Chem Rev. 2016 116, 12466-12535, the metal-organic framework exhibits a (3,5,7)-c msg network.

[0014] In one aspect, after drying at 250°C for 30 minutes under N2, the metal-organic framework of the present invention exhibits the following peak values ​​in the X-ray diffraction pattern at 30°C:

[0015] In one aspect, the peak value in the X-ray diffraction pattern after drying at 250°C for 30 minutes under N2, at 30°C, is located at:

[0016] In one respect, the A-axis and B-axis of the unit cell are each greater than 1. And the c-axis is greater than Attached Figure Description

[0017] Figure 1 This is a graph showing the increase in the yield of Mg / Mn-MOF-274 as the amount of reagent in the starting mixture increases.

[0018] Figure 2 Showing powder X-ray diffraction data for MOF-274 prepared using conventional synthesis, high-solids-content synthesis, and high-concentration synthesis.

[0019] Figure 3A, 3B, 3C, 3D, 3E, 3F, 3G, and 3H are SEM images of metal-organic framework (“MOF”) materials obtained from high solids content synthesis, conventional solvothermal synthesis, high solids concentration synthesis, and conventional solids concentration synthesis, respectively. They show that regardless of the synthesis method, the MOF materials have a rod-like shape, which is the typical morphology of MOF-274.

[0020] Figure 4 The graph shows the N2 adsorption of MOF-27 synthesized under the following conditions: (a) conventional synthesis with low reagent concentration in DMF / MeOH solvent, as 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); (b) low reagent concentration in water / THF / MeCN solvent; (c) high concentration synthesis in water / THF / MeCN solvent; and (d) high solids content synthesis. Description of preferred implementation scheme

[0021] As described herein, metal-organic frameworks are synthesized from (1) reaction solutions containing increased reagent concentrations, referred to herein as “high-concentration synthesis”, or from (2) reagent suspensions exceeding their solubility limits in the reaction solvent, referred to herein as “high-solids-content synthesis”. In both approaches, the solubility of the reagents is maximized by including a chemical buffer (“buffer”) that fixes the nominal pH of the reaction solution to enable linker deprotonation and subsequent metal-organic framework formation. These approaches improve the yield and scalability of metal-organic framework (“MOF”) materials. Conventional synthesis for manufacturing metal-organic frameworks typically yields low quantities of the final product, thus presenting challenges for scaling up, intensifying, and commercializing the materials. Here, the scalability of manufacturing metal-organic frameworks is enhanced by increasing the amount of solid reagents available relative to the solvent volume. It is essential that the quality of the metal-organic framework is not sacrificed through the scaling-up process. Several characterization techniques presented herein demonstrate that MOF materials obtained through intensified processes produce the same material with comparable or better physical properties, such as crystallinity and / or surface area.

[0022] Before disclosing and describing this method and apparatus, it is to be understood that, unless otherwise specified, the invention is not limited to specific compounds, components, compositions, reactants, reaction conditions, ligands, catalyst structures, metallocene structures, etc., as these are variable unless otherwise specified. It should also be understood that the terminology used herein is for describing particular embodiments only and is not intended to constitute limitation.

[0023] For the purposes of this disclosure, the following definitions apply:

[0024] The terms “a” and “the” used in this article are understood to include both plural and singular forms.

[0025] The term “heteroatoms” as used in this article includes oxygen (O), nitrogen (N), sulfur (S), silicon (Si), boron (B), and phosphorus (P).

[0026] The term "aryl" refers to a polyunsaturated aromatic substituent, unless otherwise specified, which can be a monocyclic or fused together or covalently linked polycyclic rings. In one aspect, the substituent has 1 to 11 rings, or more specifically, 1 to 3 rings. The term "heteroaryl" refers to an aryl substituent (or ring) containing 1 to 4 heteroatoms selected from N, O, and S, wherein the nitrogen and sulfur atoms are optionally oxidized, and the nitrogen atom is optionally quaternized. An exemplary heteroaryl is a hexaazine, such as pyridyl, diazinyl, and triazinyl. Heteroaryl groups can be linked to the rest of the molecule via heteroatoms. Non-limiting examples of aryl and heteroaryl groups include phenyl, 1-naphthyl, 2-naphthyl, 4-biphenyl, 1-pyrrole, 2-pyrrole, 3-pyrrole, 3-pyrazolyl, 2-imidazolyl, 4-imidazolyl, pyrazinyl, 2-oxazolyl, 4-oxazolyl, 2-phenyl-4-oxazolyl, 5-oxazolyl, 3-isooxazolyl, 4-isooxazolyl, 5-isooxazolyl, 2-thiazolyl, 4 -Thiazolyl, 5-thiazolyl, 2-furanyl, 3-furanyl, 2-thienyl, 3-thienyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-benzothiazolyl, purinel, 2-benzimidazolyl, 5-indolyl, 1-isoquinolinyl, 5-isoquinolinyl, 2-quinoxalinyl, 5-quinoxalinyl, 3-quinolinyl, and 6-quinolinyl. The substituents in each of the above aryl and heteroaryl ring systems are selected from the following acceptable substituents.

[0027] As used herein, the terms “alkyl,” “aryl,” and “heteroaryl” may optionally include substituted and unsubstituted forms of the class shown. Substituents in aryl and heteroaryl compounds are collectively referred to as “aryl substituents.” Substituents are selected, for example, groups attached to a heteroaryl or heteroaryl ring via a carbon or heteroatom (e.g., P, N, O, S, Si, or B), including but not limited to substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted heterocyclic alkyl groups, --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”').dbd.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, in quantities from 0 to the total number of open valences on the aromatic ring system. Each of the aforementioned groups is attached directly or via a heteroatom (e.g., P, N, O, S, Si, or B) to an aryl or heteroaryl ring; and wherein 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 the compounds of the present invention include more than one R group, for example, each R group is selected independently as if more than one R', R”, R”’, and R”” group were present.

[0028] Unless otherwise stated, the term "alkyl," alone or as part of another substituent, refers to a straight-chain or branched or cyclic hydrocarbon group or a combination thereof, which may be fully saturated, monounsaturated or polyunsaturated and may include divalent, trivalent and polyvalent groups (i.e., C1-C1) having a specified number of carbon atoms. 10This refers to groups with 1 to 10 carbon atoms. Examples of saturated hydrocarbon groups include, but are not limited to, groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, sec-butyl, cyclohexyl, (cyclohexyl)methyl, cyclopropylmethyl, and homologues and isomers of, for example, n-pentyl, n-hexyl, n-heptyl, and n-octyl. Unsaturated alkyl groups are alkyl groups having one or more double or triple bonds. Examples of unsaturated alkyl groups include, but are not limited to, vinyl, 2-propenyl, crotonyl, 2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl, 3-(1,4-pentadienyl), ethynyl, 1- and 3-propynyl, 3-butynyl, and higher homologues and isomers. Unless otherwise stated, the term "alkyl" is also intended to optionally include those alkyl derivatives as defined in more detail below, such as "heteroalkyl".

[0029] Unless otherwise stated, the term "heteroalkyl," alone or in combination with another term, refers to a stable straight-chain or branched or cyclic hydrocarbon group or combination thereof, consisting of a specified number of carbon atoms and at least one heteroatom selected from O, N, Si, and S, wherein nitrogen and sulfur atoms may optionally be oxidized, and the nitrogen heteroatom may optionally be quaternized. The heteroatoms O, N, S, and Si may be located at any internal position of the heteroalkyl group or at the position where the alkyl group is attached to the rest of the molecule. Examples include, but are not limited to, --CH2--CH2--O--CH3, --CH2--CH.2--NH--CH3, --CH2--CH2--N(CH3)--CH3, --CH2--S--CH2--CH3, --CH2--CH2, --S(O)--CH3, --CH2--CH2--S(O)2--CH3, --CH=CH--O--CH3, --Si(CH3)3, --CH2—CH=N--OCH3, and –CH=CH--N(CH3)--CH3. At most two heteroatoms can be consecutive, for example, --CH2--NH--OCH3 and --CH2--O--Si(CH3)3. Similarly, the term "heteroalkylene," alone or as part of another substituent, refers to a divalent group derived from a heteroalkylene group, such as, but not limited to, --CH2--CH2--S--CH2--CH2-- and --CH2--S--CH2--CH2--NH--CH2--. For heteroalkylene groups, the heteroatom may also occupy any one or both chain ends (e.g., alkyleneoxy, alkylenedioxy, alkyleneamino, alkylenediamino, etc.). Furthermore, for alkylene and heteroalkyl linking groups, the direction in which the chemical formula of the linking group is written does not imply the orientation of the linking group. For example, the formula --CO2R'-- represents --C(O)OR' and --OC(O)R'.

[0030] As used herein, the term "ligand" refers to a molecule containing one or more substituents that can act as Lewis bases (electron donors). In one respect, the ligand can be oxygen, phosphorus, or sulfur. In another respect, the ligand can be an amine containing 1 to 10 amino groups.

[0031] Unless otherwise stated, the term "halogen," alone or as part of another substituent, refers to a fluorine, chlorine, bromine, or iodine atom.

[0032] The symbol “R” is a general abbreviation for a substituent selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted heterocyclic alkyl.

[0033] The term "periodic table" as used in this article refers to the Periodic Table of the Elements of the International Union of Pure and Applied Chemistry (IUPAC), dated December 2015.

[0034] The term "salt" includes salts of compounds prepared by neutralization of an acid or base, depending on the specific ligand or substituent found on the compound described herein. When the compounds of the present invention contain relatively acidic functional groups, base addition salts can be obtained by contacting the neutral form of these compounds with a sufficient amount of the desired base (pure 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 salts derived from inorganic acids such as hydrochloric acid, hydrobromic acid, nitric acid, carbonic acid, monohydrocarbonic acid, phosphoric acid, monohydrophosphoric acid, dihydrophosphoric acid, sulfuric acid, monohydrosulfuric acid, hydroiodic acid, or phosphorous acid, 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, octanoic acid, fumaric acid, lactic acid, mandelic acid, phthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, citric acid, tartaric acid, and methanesulfonic acid. Certain specific compounds disclosed herein contain both basic and acidic functional groups, enabling the compounds to be converted into base or acid addition salts. Hydrates of salts are also included.

[0035] It should be understood that in any compound described herein having one or more chiral centers, each center may independently be an R configuration or an S configuration or a mixture thereof, unless explicitly indicated by absolute stereochemistry. Therefore, the compounds provided herein may be enantiomerically pure or mixtures of stereoisomers. Furthermore, it should be understood that in any compound described herein having one or more double bonds to generate geometric isomers that can be defined as E or Z, each double bond may independently be E or Z or a mixture thereof. Similarly, it should be understood that all tautomeric forms are intended to be included in any of the compounds described herein.

[0036] Furthermore, the compounds described herein may also contain atomic isotopes in non-natural proportions at one or more atoms constituting such compounds. For example, the compound may use radioactive isotopes, such as tritium ( 3 H), Iodine-125 ( 125 I) or carbon-14 ( 14 C) Radiolabeling. All isotopic variants of this compound, whether or not radioactive, are intended to be covered within the scope of this disclosure.

[0037] The term "metal-organic framework" as used herein can refer to a hybrid metal-organic framework or metal-organic framework system or a hybrid metal-organic framework system as described in U.S. Patent Application No. 62 / 839,261. Traditional synthesis

[0038] Traditionally, metal-organic frameworks are prepared by reacting pre-synthesized or commercially available linkers with metal ions. In an alternative approach known as "in-situ linker synthesis," a specified organic linker (linker) can be generated in situ from raw materials in a reaction medium.

[0039] In the synthesis of metal-organic frameworks, organic molecules are not only structure-directing agents but also reactants that are incorporated into the framework structure. Considering this, elevated reaction temperatures are typically used in conventional synthesis. Recently, solvothermal reaction conditions, structure-directing agents, mineralizing agents, and microwave-assisted synthesis or steam-assisted conversion have also been proposed.

[0040] As mentioned in this article, conventional synthesis typically involves reactions carried out via conventional electric heating without any parallel reactions. In conventional synthesis, reaction temperature is a key parameter in metal-organic framework synthesis and is generally distinguished into two temperature ranges: solvothermal and non-solvothermal, which determines the type of reaction setup used. Solvothermal reactions are typically carried out in a closed vessel under autogenous pressure near the boiling point of the solvent used. Non-solvothermal reactions occur at ambient pressure at or below the boiling point, simplifying the synthetic requirements. Non-solvothermal reactions can be further classified as room temperature or elevated temperatures.

[0041] Traditional synthesis of metal-organic frameworks is carried out in solvents and at temperatures ranging from room temperature to approximately 250°C. Heat is transferred from a heat source, furnace, or via convection. Alternatively, energy can be introduced via electric potential, electromagnetic radiation, mechanical waves (ultrasound), or mechanical means. The energy source is closely related to the duration, pressure, and energy per molecule introduced into the system, and these parameters each have a strong influence on the metal-organic framework formed and its morphology.

[0042] The conventional synthesis of metal-organic frameworks is 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), which is hereby cited and incorporated herein by reference. Typically, 0.10 mmol of the linker, 0.25 mmol of the metal salt, and 10 mL of solvent, namely methanol / dimethylformamide (DMF), are combined in a 20 mL glass scintillation tube. The tube is then sealed and placed on a hot plate at 393°K for approximately 12 hours at a depth of 2 cm, after which powder forms on the bottom and walls of the tube. The metal-organic framework material is then decanted, and the remaining powder is soaked three times in DMF and then three times in methanol. The metal-organic framework is then collected by filtration and completely desolventized by heating at 523°K for 24 hours under dynamic vacuum (<10 μbar). Using this specific method, conventional synthesis yields approximately 0.073 millimoles of metal-organic framework or 73% yield (comparing the number of millimoles of the prepared metal-organic framework to the initial number of millimoles of the linker) or a volume-normalized mass-based yield of 2.7 g MOF / L reaction solution.

[0043] In addition to the conventional synthesis described in Nature, 2015, 519, 303-308, which is hereby cited and incorporated herein, synthetic methods for manufacturing metal-organic frameworks are further described in: J. Am. Chem. Soc. 2012, 134, 7056-7065; Chem. Sci. 2018, 9, 160-174; U.S. Patent No. 8,653,292 and U.S. Patent Application Publications Nos. 2007 / 0202038, 2010 / 0307336 and 2016 / 0031920. The present invention provides a method for manufacturing metal-organic frameworks.

[0044] This document provides a method for manufacturing a metal-organic framework, wherein a high concentration of solid reagent is incorporated to provide a reaction solution having a reagent concentration approximately three (3) to seven (7) times that used in conventional solvothermal synthesis, and / or the reaction mixture is saturated with and / or suspended from the solid reagent. In either method, a metal-organic framework is formed. 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 aspect, organic linkers include polybridged aryl groups, such as molecules having two or more phenyl rings or two phenyl rings linked by vinyl or alkynyl groups.

[0045] In high-concentration synthesis, the solubility of solid reagents in the synthesis solution is increased by including a higher concentration of buffer, thereby improving the yield. More specifically, in the synthesis solution, a metal salt, one or more linkers, and a buffer are dissolved in a solvent to provide a synthesis solution with reagent concentrations. Additional solid reagents (metal salt and linker) are then added to the synthesis solution to increase the reagent concentration and provide a reaction solution. As presented herein, this method enables a volume-normalized mass basis yield of MOF-274 synthesis that is up to fifteen (15) times higher than the method described in Nature, 2015, 519, 303-308.

[0046] In high-solids-content synthesis, the reagent solids are well dispersed but not completely dissolved in the reaction mixture. More specifically, the amount of solid reagents (molten salts and linkers) exceeds the soluble amount, causing the reaction solution to become saturated. In this method, the amount of solid reagents is increased until they are no longer soluble in the reaction solution and form a suspension.

[0047] In high-concentration and high-solids-content synthesis, reagent concentrations can be increased by up to 7 times compared to conventional synthesis (Nature, 2015, 519, 303-308), resulting in a mass yield (“yield”) that is approximately 35 times the amount normalized to the volume of solvent used in the synthesis. Furthermore, both methods increase the amount of MOF produced (yield) while maintaining or reducing solvent volume and reactor size, thus allowing for potential large-scale applications.

[0048] In one aspect, high-concentration synthesis includes a method for manufacturing a metal-organic framework, comprising the steps of: combining one or more metal salts and one or more linkers in a buffer, and dissolving a solid reagent in a solvent to provide a synthesis solution. Additional metal salts and linkers are dispersed into the synthesis solution to provide a reaction solution. The reaction solution is then sealed and heated by one of various methods. In one aspect, the cumulative concentration of one or more metal salts is provided in an amount between about 25 mM and about 100 mM, and the one or more linkers are provided in an amount between about 10 mM and about 40 mM. In one aspect, the buffer concentration is between about 100 mM and about 260 mM. In one aspect, the reaction solution has a reaction concentration of about 135 mM to about 400 mM of solid reagent. In one aspect, the method can have a mass-based volume-normalized yield between about 2 and about 15 mg metal-organic framework / mL solvent.

[0049] In one aspect, in high-solids-content synthesis, the concentration of the solid reagent can be about 5 to about 35 times that of the solid reagent in conventional synthesis. In one aspect, the one or more metal salts are provided in an amount between about 175 mM and about 867 mM, and the one or more linkers are provided in an amount between about 85 mM and about 361 mM. In one aspect, the buffer concentration is between about 270 mM and about 1.624 M. In one aspect, the reaction solution has a reaction concentration of the solid reagent of about 530 mM to about 2.852 M.

[0050] This method provides mass-based volume-normalized yields of metal-organic frameworks that are approximately 10 to approximately 40 times or approximately 14 to approximately 35 times greater than those in conventional synthesis.

[0051] As described herein, the metal salt can be a divalent first-row transition metal salt having the formula MX2, such as M = Mg, Mn; X2 = (Oac)2, (HCO3)2, (F3CCO2)2, (acac)2, (F6acac)2, (NO3)2, SO4; M = Ni, X2 = (Oac)2, (NO3)2, SO4; M = Zn, X2+(Oac)2, (NO3)2. In one aspect, the metal salt can be in the form of crystals or crystalline powder. In another aspect, the metal salt is, for example, Mg(NO3)2·6H2O and MnCl2·4H2O.

[0052] As described herein, a metal-organic framework is a porous crystalline material formed by one or more different metal cations, clusters, or chains linked by two or more multitopic (polytopic) organic linkers. In one respect, the metal-organic framework is Mg / Mn-MOF-274, sometimes referred to as MOF-274.

[0053] As described herein, suitable linkers can be formed by two phenyl rings linked at carbons 1,1', a carboxylic acid at carbons 3,3', and an alcohol at carbons 4,4'. Swapping the positions of the carboxylic acid and alcohol (e.g., "pc-H4DOBPDC" or "pc-MOF-274") does not alter the topology of the metal-organic framework. In one aspect, the linker is H4DOBDPC.

[0054] Solvents that can be used in this method include, for example, water, acetonitrile, and tetrahydrofuran. More specifically, the solvent is approximately 20 to approximately 30 vol% water, approximately 35 to approximately 40 vol% acetonitrile, and approximately 35 to approximately 40 vol% tetrahydrofuran. Optionally, the solvent can be selected by evaluating the Hansen solubility parameter.

[0055] Metal-organic frameworks can be synthesized at room temperature or by conventional electric heating, microwave heating, electrochemical methods, mechanochemical methods, and ultrasonic methods. Conventional stepwise methods and high-throughput methods are also possible. However, in any synthesis, conditions must be established to generate the specified inorganic structural units without decomposing the organic linkers. Simultaneously, the crystallization kinetics must allow for the nucleation and growth of the desired phase.

[0056] The heating and sealing steps may include heating the reaction solution under static conditions for approximately 96 hours. The heating and sealing steps may also include heating the reaction solution under dynamic conditions (e.g., stirring, shaking, mixing, or agitation) for approximately 24 hours. The heating and sealing steps may include heating the reaction solution in a static furnace at approximately 120°C. The heating and sealing steps may also include heating the reaction solution in a rotary furnace at approximately 150°C. Heating can be carried out without sealing, wherein MOFs are synthesized under solvent reflux at a pressure of approximately 1 bar. In one aspect, the reaction solution is typically heated to 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.

[0057] This approach is advantageous because it reduces the cost and labor required to obtain high-quality MOFs. Since these methods require less time and can synthesize more materials, they also provide more materials available for testing and characterization, and the significant reduction in time can have a major economic impact. This novel approach therefore represents a process intensification in MOF synthesis.

[0058] Essentially, the quality of MOFs must not be sacrificed through scaling up the process. Several characterization techniques described in detail below demonstrate that the novel methods disclosed in this paper produce MOFs of similar or better quality compared to conventional synthesis. Metals and metal salts

[0059] Metal-organic frameworks comprise two or more different metal cations, clusters, or chains linked by two or more multi-site organic linkers. In one aspect, the metal-organic framework prepared by this method comprises one or more different elements independently selected from Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu, and Zn. In another aspect, each of the one or more different elements is a metal, more particularly Mg, Mn, Ni, or Zn.

[0060] More specifically, the metal in the metal-organic framework of this invention can be one of the elements in Groups IIA, IIIB, IVB, VB, VIB, VIIB, VIII, IB and IIB of Period 4 and Group IIA of Period 3 of the periodic table, including Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu and Zn. Furthermore, the metal-organic framework can contain two other different elements and different combinations of metals, theoretically represented as M 1 x M 2 y …M n z (A)(B)2|x+y+…+z=2 and M 1 ≠M 2 ≠…≠M n , where x, y and z are each independent values ​​from 0.0 to 2.0.

[0061] The metal can be a monovalent metal, which will be made into a protonated form of the linker. For example, the metal could be Na. +Or it may be from Group I. The metal may also be one of two or more divalent cations (“divalent metals”) or trivalent cations (“trivalent metals”). In one aspect, the metal-organic framework includes metals in oxidation states other than +2 (i.e., not only divalent, but also trivalent, tetravalent, ...). The framework may have a mixture of metals comprising different oxidation states. Exemplary 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 having a +3 oxidation state. Some metals used to form the metal-organic framework, particularly Fe and Mn, may be in a +2 (divalent) or +3 (trivalent) oxidation state under relatively mild conditions. Chem. Mater, 2017, 29, 6181. Similarly, Cu(II) may form Cu(I) under mild conditions. Thus, any small change in the oxidation state of any metal and / or a selective change in the metal oxidation state can be used to modify the metal-organic framework of the present invention. In addition, different molecular fragments C1, C2, ... C may exist. n Any combination of these. Finally, all the above variations can be combined, for example, multiple metals (two or more different metals) with multiple valence states and multiple charge balance molecular fragments.

[0062] In this method, as described herein, the metal can be provided as a divalent first-row transition metal salt MX2, such as M = Mg, Mn; X2 = (Oac)2, (HCO3)2, (F3CCO2)2, (acac)2, (F6acac)2, (NO3)2, MX, such as M = Mg, Mn; X = SO4, CO3; M = Ni, X2 = (Oac)2, (NO3)2, SO4; M = Zn, X2+(Oac)2, (NO3)2. Examples of metals (M) suitable for this metal salt 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, ruthenium, pembrolizum, thorium, and others. Ferrite, ruthenium, etc. Other metal sources may include metal oxides, metal hydroxides, metal sulfides, metal chalcogenides, pure metals, or any combination of metal sources.

[0063] Examples of counterions in metal salts include, but are not limited to, nitrate, nitrite, phosphate, phosphite, sulfate, sulfite, fluoride, chloride, bromide, iodide, acetate, and carbonate. Any metal can be in any salt form and the choice is based on the ability of the metal salt (metal / counterion combination) to dissolve in a solvent. Metal salts can be hydrates, alkoxides, or pyruvates.

[0064] As described herein, metal-organic frameworks (MOFs) are synthesized by mixing or otherwise combining metal salts and organic linkers. Suitable metal ions include metals and metalloids with different coordination geometries and oxidation states. In one aspect, MOFs are produced using metal ions with significantly different coordination geometries combined with ligands having polydentate functional groups and suitable template agents. A preferred octahedral coordinated metal ion is cobalt(II). A preferred tetrahedral coordinated metal ion is zinc(II). MOFs may use one or more of the following metal ions: Mg 2+ Ca 2+ 、Sr 2+ Ba 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 + and Bi 5+ Bi 3+ Bi + Be 2+ It is manufactured together with the corresponding metal salt counterions.

[0065] The term "metal ion" refers to both metal ions and metalloid ions. In one aspect, metal ions suitable for the production of MOFs may 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+ Sn4+ Sn 2+ Pb 4+ Pb 2+ Sb 5+ Sb 3+ Sb + , and / or Bi 5+ Bi 3+ Bi + Be 2+ Together with corresponding metal salt counterions. In one aspect, the metal ions used to produce 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 + Together with corresponding metal salt counterions. In one aspect, the metal ions used to produce MOFs are selected from: 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+ Together with the corresponding metal salt counterions.

[0066] Generally, metal salts include various salts of compounds prepared by neutralization with acids or bases, depending on the specific substituents found on the compound. When a compound contains a relatively acidic functional group, a base addition salt can be obtained by contacting the neutral form of the compound with a sufficient amount of the desired base (pure 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 salts derived from inorganic acids such as hydrochloric acid, hydrobromic acid, nitric acid, carbonic acid, monohydrocarbonic acid, phosphoric acid, monohydrophosphoric acid, dihydrophosphoric acid, sulfuric acid, monohydrosulfuric acid, hydroiodic acid, or phosphorous acid, 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, octanoic acid, fumaric acid, lactic acid, mandelic acid, phthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, citric acid, tartaric acid, and methanesulfonic acid. Some compounds may contain both basic and acidic functional groups, allowing them to be converted into base or acid addition salts. Salt hydrates are also included. Connector

[0067] Suitable organic linkers (also referred to as "linkers" in this document) can depend on the structure of the metal-organic framework and the symmetry operation of the linker portion involving binding to the metal nodes of the metal-organic framework. Note that the ligands are chemically and / or structurally distinct and can associate the metal node binding region of the metal-organic framework with the C2 symmetry axis.

[0068] In one aspect, the connector may include:

[0069] R1 is connected to R1', and R2 is connected to R2.

[0070] Exemplary connectors include: Where R is any molecular fragment.

[0071] Other examples of organic linkers include p-carboxylic acids (salts) (“pc-linkers”), such as 4,4'-dioxobiphenyl-3,3'-dicarboxylic acid (DOBPDC); 4,4”-dioxo-[1,1':4',1”-terphenyl]-3,3”-dicarboxylic acid (DOTPDC); and dioxobiphenyl-4,4'-dicarboxylic acid (p-carboxylic acid-DOBPDC, also known as PC-DOBPDC), as well as the following compounds:

[0072] In one respect, organic linkers have the following formula:

[0073] Where R 11 R 12 R 13 R 14 R 15 R 16 R 17 R 18 R 19 and R 20 Each is independently selected from H, halogen, hydroxyl, methyl and halogen-substituted methyl.

[0074] In one respect, organic linkers have the following formula:

[0075] Where R 11 R 12 R 13 R 14 R 15 and R 16 Each is independently selected from H, halogen, hydroxyl, methyl and halogen-substituted methyl.

[0076] In one respect, organic linkers have the following formula:

[0077] Where R 11 R 12 R 13 R 14 R 15 and R 16 Each is independently selected from H, halogen, hydroxyl, methyl, or halogen-substituted methyl, and R 17 Selected from substituted or unsubstituted aryl, vinyl, ynyl and substituted or unsubstituted heteroaryl groups.

[0078] In one respect, organic linkers have the following formula:

[0079] Where R 11 R 12 R 13 R 14 R 15 and R 16 Each is independently selected from H, halogen, hydroxyl, methyl, or halogen-substituted methyl.

[0080] Where R 11 R 12 R 13 R14 R 15 and R 16 Each is independently selected from H, halogen, hydroxyl, methyl, or halogen-substituted methyl, and R 17 Selected from substituted or unsubstituted aryl, vinyl, ynyl and substituted or unsubstituted heteroaryl groups.

[0081] Examples of linkers include, but are not limited to, 4,5-dicyanimidazole, substituted 4,5-dicyanimidazole, oxalic acid, ethyl oxalic acid, fumaric acid, 1,3,5-benzenetribenzoic acid (BTB), DCPB, phenyltribenzoic acid (BBC), 5,15-bis(4-carboxyphenyl)zinc(II)porphyrin (BCPP), 1,4-phthalic acid (BDC), and 2-amino-1,4-phthalic acid (R3-BDC or H2N). BDC), 1,1′-azo-diphenyl-4,4′-dicarboxylic acid, cyclobutyl-1,4-phthalic acid (R6-BDC), triphenylcarboxylic acid, 2,6-naphthalenedicarboxylic acid (NDC), 1,1′-biphenyl-4,4′-dicarboxylic acid (BPDC), 2,2′-bipyridine-5,5′-dicarboxylic acid, adamantane tetracarboxylic acid (ATC), adamantane dibenzoic acid (ADB), dihydroxyterephthalic acid (DHBDC), biphenyl tetracarboxylic acid (BPTC), tetrahydropyrene 2,7-dicarboxylic acid (HPDC), dihydroxyterephthalic acid (DHBC), pyrene 2,7-dicarboxylic acid (PDC), pyrazine dicarboxylic acid, acetylene dicarboxylic acid Formic acid (ADC), camphor dicarboxylic acid, fumaric acid, benzotetracarboxylic acid, 1,4-bis(4-carboxyphenyl)butadiene, nicotinic acid and terphenyl dicarboxylic acid (TPDC), 2,5-dihydroxy-1,4-phenyl-dicarboxylic acid (H4DOBDC), 4,4'-dihydroxybiphenyl-3,3'-dicarboxylic acid (H4DOBPDC), 4,4”-dihydroxy-[1,1':4',1”-terphenyl]-3,3”-dicarboxylic acid (H4DOTPDC), 3,3'-dihydroxybiphenyl-4,4'-dicarboxylic acid (pc-DOBPDC), etc., substituted derivatives of the above linkers, and any combination thereof.

[0082] Linker H4DOBPDC or 4,4'-dihydroxy-(1,1'-biphenyl)-3,3'-dicarboxylic acid are organic linker compounds that can be synthesized as reported in Lindsey, AS; Jeskey, H. Chem. Rev. 1957, 57(4), 583-620, or are commercially available. Chemical buffers

[0083] In any of the methods described above, the solubility of the reagents is maximized by incorporating a chemical buffer (referred to herein as a "buffer"), which fixes the nominal pH of the reaction solution to facilitate linker deprotonation and subsequent metal-organic framework formation. The buffer may comprise an acid and its conjugate base, or a base and its conjugate acid. The buffer can be generated in situ by adding a buffer acid and then adding an alkaline solution to the appropriate pH. Similarly, the buffer can be generated in situ by adding a buffer base and then adding an acidic solution to the appropriate pH. In one aspect, the buffer may be 3-(N-morpholino)propanesulfonic acid ("MOPS") or Na MOPS.

[0084] Examples of suitable bases include, but are not limited to, piperazine, 1,4-dimethylpiperazine, sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonium hydroxide, and any combination thereof.

[0085] 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, phosphorous acid, sulfuric acid, formic acid, hydrofluoric acid, and any combination thereof.

[0086] Examples of suitable acids and conjugate bases, and suitable bases and conjugate acids used to buffer nominal pH, include, but are not limited to, acetate / acetate, citric acid / citrate, boric acid / borate, etc. These buffers are referred to as “Good Buffers”, defined in Biochemistry, 1966, 5, 467-477, which is incorporated herein by reference, and non-complexed tertiary amine buffers defined in Anal Chem., 1999, 71, 3140-3144, which is also incorporated herein by reference, are referred to as “Better Buffers”.

[0087] Buffers may include potential variations on MOPS and may have the following formula:

[0088] Where n = an integer between 1 and 10, any atom bridging R1 and R7 can be functionalized with chemical substituents, or “R” as defined in paragraphs

[0027] to

[0030] ,

[0032] and

[0033] above;

[0089] R1, R2, R3, R4, R5, and R6 are each independently C, O, N, or S; and

[0090] R7 is any Brønsted acid functional group or corresponding conjugate base, sulfonic acid, phosphonic acid and / or sulfoxylate, phosphonate, phosphate, hydroxyl, ammonia or sulfate. solvent

[0091] Examples of solvents that can be used alone or in solvent mixtures in this method 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, γ-butyrolactone (GBL), heptane, hexane, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, isopropyl acetate, and isophorone. d-Limonene, methyl acetate, methyl ethyl ketone, N-methyl-2-pyrrolidone (NMP), dichloromethane, 1-nitropropane, n-propyl acetate, propylene carbonate, water, dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), water, N,N-dimethylformamide (DMF), N,N-dimethylacetamide, 1,3-dimethylacrylurea, hexamethylphosphoramide, dimethyl ether, diethyl ether, methyl ethyl ether, pentane, benzene, cyclohexane, n-hexane, n-octane, kerosene, dodecane, methylcyclohexane, toluene, etc.

[0092] The Hansen solubility parameter can be derived from the Hildebrand solubility parameter, which correlates solubility with the square root of the cohesive energy density. A drawback of defining solubility as a single parameter, as proposed by Hildebrand, is that it fails to account for intermolecular interactions, such as those arising from polar or hydrogen bonding. In contrast, the Hansen solubility parameter is based on the understanding that the total energy of vaporization and therefore the total cohesive energy has several separate components, arising from atomic dispersion forces, dipole-dipole forces between permanent dipoles, and hydrogen bonding. Therefore, there are three Hansen solubility parameters, each typically expressed in MPa. 0.5 Measured in units: the energy from the dispersive forces between molecules (also known as the dispersion parameter or δ). D The energy derived from the intermolecular dipole internal forces (also known as the polarity parameter or δ) P ) and the energy from intermolecular hydrogen bonds (also known as the hydrogen bond parameter or δ) H Materials with similar Hansen solubility parameters have a high affinity for each other, and the degree of similarity determines the extent of their interaction. Therefore, Hansen solubility parameters provide a more quantifiable means of understanding the idiom "like dissolves like" and are often used to predict whether one material will dissolve in another to form a solution. See Hansen Solubility Parameters: A User's Handbook, Charles M. Hansen, CRC Press, Boca Raton, FL. (2007, 2nd edition).

[0093] Hansen solubility parameters for certain solvents and solvent compounds (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 edition). The Hansen solubility parameter of a new molecule can be experimentally determined by dispersing the molecule in a series of solvents with known Hansen solubility parameters. After identifying which solvents dissolve the molecule, the Hansen solubility parameters of these solvents are plotted using Cartesian coordinates—providing a sphere of solubility in so-called “Hansen space” by assigning each parameter to its own axis. The center of the solubility sphere defines the empirical Hansen solubility parameter of the molecule. Furthermore, the Hansen solubility parameter of a solvent mixture can be calculated by a volume-weighted average of the Hansen solubility parameters of the individual components in the mixture. In one respect, solvents are selected by evaluating their Hansen solubility parameters.

[0094] As a non-limiting example, a metal-organic framework can be synthesized by dissolving one or more metal salts and one or more linkers in a solvent at a total metal salt to total linker 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) to produce a reaction solution.

[0095] As described in the following examples, metal-organic frameworks were prepared by conventional methods and novel methods described herein, and then characterized. Example 1

[0096] Metal-organic frameworks (MOFs) are synthesized using three methods: conventional synthesis, high-concentration synthesis, and high-solids-content synthesis. MOFs are synthesized either by (1) solutions containing increased reagent concentrations or by (2) saturated suspensions of reagents exceeding their solubility limits in the reaction solvent. In both methods, reagent solubility is maximized by including buffers that fix the nominal pH of the solution to facilitate linker deprotonation and subsequent MOF formation. Both methods improve the yield and scalability of MOF materials. It is essential that the quality of the MOFs is not sacrificed during the scalability process. Several characterization techniques indicate that MOFs obtained through enhanced processes produce identical materials. Traditional synthesis

[0097] The general protocol for synthesizing MOF-274 is from Nature, 2015, 519, 303–308. 27.4 mg–41.1 mg (0.1–0.15 mmol) of the linker H4DOBPDC were combined with 0.25–0.375 mmol of a metal salt and dissolved in 10 mL of the mixed solvent. This solution was sealed in a 20 mL glass scintillation tube and heated at 120 °C for 12 h. The solid was collected and washed. Yields of 23.3–54.1 mg of material were obtained. High concentration synthesis

[0098] To prepare Mg / Mn-MOF-274 at high concentrations of solid reagents, 0.75 mmol H₄DOBPDC, 1.68 mmol Mg(NO₃)₂·6H₂O, 0.19 mmol MnCl₂·4H₂O, and 7.5 mmol Na MOPS buffer were dissolved in 75 mL of a solvent consisting of 0.25:0.37:0.38 water:acetonitrile:tetrahydrofuran. Once all solids were completely dissolved, an additional 3 mmol H₄DOBPDC, 6.72 mmol Mg(NO₃)₂·6H₂O, 0.76 mmol MnCl₂·4H₂O, and 12 mmol Na MOPS were added to the system. The reaction solution was transferred to a 125 mL Teflon-lined Parr autoclave, sealed, and heated at 120 °C for 96 hours under static conditions. A yield of 1.08 g of Mg / Mn-MOF-274 was obtained. High solids content synthesis

[0099] To obtain a higher yield of Mg / Mn-MOF-274, a metal-organic framework was prepared under high solids content conditions. Following the conventional synthetic method described above, 1.484 mmol H4DOBPDC, 11.696 mmol Mg(NO3)2·6H2O, 1.300 mmol MnCl2·4H2O, and 24.4 mmol Na MOPS buffer were mixed in 15 mL of a solvent consisting of 0.25:0.37:0.38 water:acetonitrile:tetrahydrofuran until all solids were fully dispersed. Note that the reagents were not completely dissolved in the reaction solution. The reaction solution was transferred to a 23 mL Teflon-lined Parr autoclave, sealed, and placed in an inverted oven at 150 °C for 24 hours. A yield of 3.6 g of Mg / Mn-MOF-274 was obtained.

[0100] A summary of the different syntheses used for the above-mentioned conventional synthesis, high-concentration synthesis and high-solids-content synthesis is provided in Table 1 below. Table 1. Comparison of Synthetic Results

[0101] As shown in Table 1, increasing the reagent concentration by 35-fold compared to the synthesis reported in the literature resulted in a nearly 45-fold increase in mass yield when normalized by the volume of solvent used in the synthesis. The mass (yield) of the metal-organic framework MOF-274 depending on each synthetic method is shown in the table. Figure 1 Importantly, although the solid reagent content is increased above the point where all solids are completely dissolved in the reaction solution (saturated suspension), as... Figure 2 , 3 As shown in Figure 4, the quality of the material was not sacrificed.

[0102] like Figure 2 As shown, powder X-ray diffraction patterns confirm that materials of the same phase were synthesized using a high solids:solvent ratio method, compared to conventional solids content (prepared using conventional synthesis methods):solvent ratio (prepared using conventional solvents as reported in the literature) and high solids:solvent concentration methods. Amines did not attach to these metal-organic frameworks, nor did they functionalize or activate them.

[0103] Powder X-ray diffraction (“PXRD”) data further revealed considerable material crystallinity, supported by SEM images showing a persistent rod-like morphology with discrete crystallite formation. Figure 3 Surface area measurements showed that high-concentration and high-solids-content synthesis provided a similar surface area to the metal-organic framework compared to conventional synthesis. SEM images provided a qualitative assessment of the bulk material shape, morphology, and polydispersity. Images were acquired on a Hitachi SEM using an upper detector at 2 keV acceleration.

[0104] like Figure 4 As shown, the N2 adsorption isotherms confirm that MOFs prepared via high-concentration synthesis and high-solids-content synthesis possess surface areas similar to those of conventionally synthesized MOFs. Specifically, N2 adsorption of MOF-274 was observed under literature conditions (low concentration in DMF / MeOH), at low concentration in water / THF / MeCN, at high concentration in water / THF / MeCN, and in water / THF / MeCN via high-solids-content synthesis. The metal-organic frameworks prepared via high-concentration synthesis and high-solids-content synthesis exhibited N2 absorption ranging from approximately 25 mmol / g to approximately 40 mmol / g at relative pressures between approximately 0.1 and approximately 0.9.

[0105] In summary, characterizing metal-organic frameworks (MOFs) was used to analyze the similarity between MOFs synthesized via conventional synthesis and those synthesized via high-concentration and high-solids-content synthesis. Although reagent concentrations were increased beyond the point where all solids are completely dissolved in the reaction solution, as... Figure 2-4As shown, the quality of the material was not sacrificed. Figure 2 As shown, powder X-ray diffraction data confirm that materials of the same phase are produced using high-solids-content synthesis and high-concentration synthesis, compared to conventional synthesis. Specifically, the metal-organic frameworks prepared by high-concentration synthesis and high-solids-content synthesis exhibit powder X-ray diffraction peaks at 2θ values ​​between approximately 4° and approximately 6° and between approximately 7° and approximately 9°, which are similar to those of metal-organic frameworks prepared by conventional synthesis. Figure 2 The powder X-ray diffraction data revealed a considerable degree of material crystallinity. Figure 3 The scanning electron microscope images in the image further support this. Figure 3 Scanning electron microscope images show that regardless of the synthesis method, the resulting material is rod-shaped, which is the typical morphology of MOF-274. Figure 3 In the diagram, the images in each column correspond to the same sample photographed at different magnifications. As shown, the metal-organic frameworks prepared by high-concentration synthesis and high-solids-content synthesis exhibit similar crystallinity to those prepared by conventional synthesis.

[0106] Certain features have been described using a set of upper and lower numerical limits. It should be understood that, unless otherwise specified, ranges from any lower limit to any upper limit are contemplated. Some of the lower limits, upper limits, and ranges appear in one or more of the following claims. All numerical values ​​take into account experimental errors and variations expected by those skilled in the art.

[0107] Various terms have been defined above. If a term used in the claims is not defined above, it shall be given the broadest definition that a person skilled in the art has given to the term, as reflected in at least one printed publication or granted patent. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated herein by reference to the extent that such disclosures do not contradict this application and to all jurisdictions where such incorporation is permitted.

[0108] The foregoing specification of this disclosure exemplifies and describes the method. Furthermore, this disclosure demonstrates and describes exemplary methods, but it is to be understood that various other combinations, modifications, and environments may be used, and the method is capable of variations or modifications within the scope of the concepts expressed herein, commensurate with the foregoing teachings and / or skills or knowledge in related fields.

Claims

1. A method for manufacturing a metal-organic framework, comprising the steps of: A synthesis solution is prepared by dissolving a variety of solid reagents and buffers in a solvent, wherein the solid reagents comprise at least one metal salt and at least one linker; and A certain amount of the various solid reagents is added to the synthesis solution to produce a reaction solution with a certain reagent concentration, wherein the reagent concentration of the reaction solution is 3 to 7 times that of the reagent concentration in conventional solvothermal synthesis. The reaction solution is heated to 50°C to 175°C for 1 hour to 7 days. The metal-organic framework described therein is of formula: M 1 x M 2 (2-x) (A), where M 1 and M 2 A is a metal cation, x is 0 to 2, and A is a disalicylic acid organic linker, wherein the disalicylic acid organic linker A is at least one p-carboxylate selected from the group consisting of: 4,4'-dioxobiphenyl-3,3'-dicarboxylate, 4,4''-dioxo-[1,1':4',1''-terphenyl]-3,3''-dicarboxylate, and dioxobiphenyl-4,4'-dicarboxylate. The metal is at least one of Mg, Mn, Ni, and Zn. The buffer is a Brønsted acid and its conjugate base, or a Brønsted base and its conjugate acid, wherein the buffer belongs to a class comprising morpholine and a sulfonic acid bridged by an alkyl group. The solvent mentioned above contains water, acetonitrile, and tetrahydrofuran, and The reaction solution has a reaction concentration of solid reagent ranging from 135 mM to 400 mM.

2. A method for manufacturing a metal-organic framework, comprising the steps of: A reaction mixture is prepared by mixing a certain amount of various solid reagents and a buffer in a solvent, wherein the solid reagents comprise at least one metal salt and at least one linker, and the amount of the various solid reagents exceeds the amount soluble in the solvent at 18°C ​​to 22°C, such that the reaction mixture is a saturated suspension. The reaction mixture is heated to 50°C to 175°C for 1 hour to 7 days. The metal-organic framework described therein is of formula: M 1 x M 2 (2-x) (A), where M 1 and M 2 A is a metal cation, x is 0 to 2, and A is a disalicylic acid organic linker, wherein the disalicylic acid organic linker A is at least one p-carboxylate selected from the group consisting of: 4,4'-dioxobiphenyl-3,3'-dicarboxylate, 4,4''-dioxo-[1,1':4',1''-terphenyl]-3,3''-dicarboxylate, and dioxobiphenyl-4,4'-dicarboxylate. The metal is at least one of Mg, Mn, Ni, and Zn. The buffer is a Brønsted acid and its conjugate base, or a Brønsted base and its conjugate acid, wherein the buffer belongs to a class comprising morpholine and a sulfonic acid bridged by an alkyl group. The solvent mentioned herein includes 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 solution has a reaction concentration of solid reagent from 530 mM to 2.852 M.

5. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the reaction solution or reaction mixture is kept non-static for 24 to 96 hours.

6. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the reaction solution or the reaction mixture is heated between 100°C and 160°C.

7. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the linker is 4,4'-dioxobiphenyl-3,3'-dicarboxylic acid.

8. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the metal salt is prepared by neutralization of metal ions with an acid or base.

9. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the counterions in the metal salt include nitrate, nitrite, phosphate, phosphite, sulfate, sulfite, fluoride, chloride, bromide, iodide, acetate and / or carbonate.

10. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the metal salt is Mg(NO3)2·6H2O and MnCl2·4H2O.

11. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the buffer is 3-(N-morpholino)propanesulfonic acid or Na MOPS.

12. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the metal-organic framework is MOF-274.

13. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the nominal pH of the reaction solution is capable of deprotonating the linker.

14. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the solvent is selected by evaluating the Hansen solubility parameter.

15. The method of manufacturing a metal-organic framework according to claim 1 or 2, wherein the reaction solution or the reaction mixture is heated under static, inverted or stirred conditions.

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