Process for the preparation of a metal-organic compound

Abstract

A process for the preparation of a metal-organic compound, said metal-organic compound comprising at least one metal ion and at least one organic ligand, wherein said organic ligand is capable of associating with said metal ion, comprising at least the steps of; providing a first reactant comprising at least one metal in ionic form; providing a second reactant comprising at least one organic ligand capable of associating with said metal in ionic form; and admixing said first and second reactants under conditions of prolonged and sustained pressure and shear sufficient to synthesize said metal-organic compound.

Claims

1. A process for the preparation of a metal-organic compound, said metal-organic compound comprising at least one metal ion and at least one organic ligand, wherein said organic ligand is capable of associating with said metal ion, the process comprising: a. providing a first reactant comprising at least one metal in ionic form, wherein the metal is selected from Zn, Co, Mg, Cu, Al, a lanthanide, Fe, Li, Sc, Mn, Cr, Ti, Zr, Ni, and combinations thereof; b. providing a second reactant comprising at least one organic ligand capable of associating with said metal in ionic form, wherein the second reactant is an imidazole, pyridine, or carboxylic acid, moiety; and c. admixing said first and second reactants under conditions of prolonged and sustained pressure and shear sufficient to synthesise said metal-organic compound.

2. The process as claimed in claim 1, wherein said pressure and shear are applied by an extrusion process.

3. The process of claim 2, wherein the extrusion process is a screw-based extrusion process.

4. The process of claim 3, wherein the screw-based process is a multiple screw-based extrusion process.

5. The process of claim 4, wherein the screw-based extrusion process is a twin-screw extrusion process.

6. The process of claim 5, wherein the twin-screw extrusion process is a co-rotating twin-screw extrusion process or a counter-rotating twin-screw extrusion process.

7. The process of claim 3, wherein the screws are at least partially intermeshing.

8. The process as claimed in claim 1, wherein at least one of the first reactant and the second reactant in steps (a) and (b) is dry.

9. The process as claimed in claim 1, wherein the mixing of the reactants in step (c) is dry-mixing.

10. The process as claimed in claim 1, wherein the mixing of the reactants together is carried out in an extruder in the absence of an added solvent.

11. The process as claimed in claim 1, wherein the process is carried out in the presence of a liquid.

12. The process as claimed in claim 11, wherein the liquid is a solvent.

13. The process of claim 12, wherein said solvent is a hydrocarbon, an alcohol, water, an amide, an amine, an ester, an ionic liquid, a carboxylic acid, a base, an ether, a halogenated solvent, an aromatic solvent a sulfoxide or any combination of such solvents.

14. The process as claimed in claim 1, wherein the first reactant is a salt, or in salt form, including an oxide.

15. The process as claimed in claim 14, wherein the first reactant is a metal nitrate, nitrite, oxide, hydroxide, alkoxide, aryloxide, carbonate, sulfate, acetate, formate, benzoate, acetylacetonate, fluoride, chloride, bromide, iodide, or tartrate, hydrogen carbonate, phosphate, hydrogen phosphate, dihydrogen phosphate or sulfonate.

16. The process as claimed in claim 1, wherein the first and second reactants are exposed to additional heat during step (c).

17. The process as claimed in claim 16, wherein said first and second reactants are exposed to a temperature within 20° C. of the melting point of one of the first and second reactants.

18. The process as claimed in claim 1, wherein the process is a continuous process.

19. The process as claimed in claim 2, wherein the first and second reactants are mixed prior to passing into the extruder.

20. The process as claimed in claim 1, further providing step (d) heating the so-formed metal-organic compound in a subsequent heating step.

21. The process as claimed in claim 20, wherein said heating step involves a temperature change of up to 250° C.

22. The process as claimed in claim 1, wherein the process includes more than two reactants to obtain a multi-metal and/or multi-bridging-substance 2D or 3D metal-organic compound.

23. The process as claimed in claim 1, where the second reactant is selected from the group consisting of 2-methyl imidazole; 2-ethylimidazole; benzimidazole; trans-1,4-butene dicarboxylic acid (fumaric acid); 2-methyl imidazole; Isonicotinic acid; 1,4-benzenedicarboxylic acid (terephthalic acid); 1,3,5-benzenetricarboxylic acid; 2,5-dihydroxybenzene 1,4-dicarboxylic acid (2,5-dihydroxyterephthalic acid); 4,4′-bipyridine; 1,3 benzene dicarboxylic acid; and 4,4′-biphenyldicarboxylic acid.

Description

DRAWINGS

(1) FIG. 1 is a schematic diagram showing the basic layout of the Haake Rheomex and ThermoFisher Process twin screw extruders;

(2) FIG. 2 shows the screw configuration for the Haake Rheomex extruder;

(3) FIG. 3 shows the screw configuration for the ThermoFisher Process 11 extruder;

(4) FIG. 4 shows simulated and experimental PXRD patterns relating to the synthesis of ZIF-8 by extrusion;

(5) FIG. 5 shows simulated and experimental PXRD patterns relating to the synthesis of CuBTC by extrusion;

(6) FIG. 6 shows PXRD traces of the activated first extrudates from the extrusions of example 11 at varying speeds (55, 75 and 95 rpm);

(7) FIG. 7 shows PXRD traces of the activated extrudate from extrusion at 200° C. (55 rpm) (- - -) and the simulated PXRD trace of ZIF-8 from CCDC (-);

(8) FIG. 8—shows PXRD traces of the activated extrudate from extrusion of 1 kilo of reagents at 95 rpm (- - -) and the simulated PXRD trace of ZIF-8 from CCDC (-);

(9) FIG. 9 shows PXRD traces of the activated extrudate from Cu.sub.3(BTC).sub.2 synthesis at varying speeds;

(10) FIG. 10 shows PXRD traces of the activated extrudate from Cu.sub.3(BTC).sub.2 on a kilo scale;

(11) FIG. 11 shows PXRD traces of the activated extrudate from Cu.sub.3(BTC).sub.2 synthesis with reduced residence time;

(12) FIG. 12 shows PXRD traces of the activated extrudate from Cu.sub.3(BTC).sub.2 synthesis with reduced residence time;

(13) FIG. 13 shows PXRD traces of synthesized ALq.sub.3.AcOH (- - -) and the corresponding simulated pattern of ALq.sub.3 (-);

(14) FIG. 14 shows PXRD traces of synthesized [Ni(NCS).sub.2(PPh.sub.3).sub.2] (- - -) and the corresponding simulated pattern (-)

(15) FIG. 15 shows PXRD traces of synthesized [Ni(Salen)] (- - -) and the corresponding simulated pattern (-);

(16) FIG. 16 shows photographs of the PTFE screw used in example 24;

(17) FIG. 17 shows PXRD traces of ZIF-8 prepared from single screw extrusion (- - -) versus the simulated pattern (-) of ZIF-8 taken from CCDC.

EXPERIMENTAL METHODOLOGY

(18) General Aspects

(19) General aspects: Two different models of extruder were used, the Haake Rheomex OS PTW16 co-rotating twin screw extruder and the ThermoFisher Process 11 co-rotating twin screw extruder.

(20) FIG. 1 is a schematic diagram showing the basic layout of both extruders. The lower part of the barrel consists of a single piece, whereas the upper part is assembled in six sections. Some sections contain a plug that can be removed, so that a feeding neck can be inserted. The plug is circled and shows the two Allen-key screws that allow it to be fixed into the barrel and removed. The screws are not shown in this diagram so that the cross sectional shape of the empty barrel can be visualised.

(21) Haake Rheomex

(22) For the Haake Rheomex extruder, a metered feeding system was used. It consists of a simple funnel hopper that drops the material onto a single screw, which then conveys it to an opening allowing it to drop into the extruder barrel. This device has a screw diameter of 16 mm and a screw length to diameter (L/D) ratio of 25:1. It features five temperature-controlled barrel zones and a segmented screw configuration to allow fine control of the extrusion process. The screw configuration used throughout all the experiments on this instrument was FS (×7), F30 (×5), F60 (×3), A90 (×4), FS (×3), FS (½), F30 (×3), F60 (×1), FS (×3), F30 (×3), F60 (×3), F30 (×6), FS (×3), EXT. Specifications for each screw element are contained in the user manual for this equipment. The screw configuration for the Haake Rheomex extruder can be seen in FIG. 2.

(23) ThermoFisher Process 11 Extruder

(24) The ThermoFisher Process 11 extruder used a gravimetric micro twin-screw feeder. The hopper of this was an enclosed cylinder and had three rotating arms upon an axle spaced at 120° to each other. This allowed the continual agitation of the powder before feeding which prevents particles from adhering together. The screw configuration used throughout all the experiments on this instrument was FS (×9), F30 (×5), F60 (×3), A90 (×4), FS (×7), F60 (×6), FS (×8), F60 (×4), A90 (×8), FS (×7), EXT. Specifications for each screw element are contained in the user manual for this equipment. The, screw configuration for the ThermoFisher Process 11 can be seen in FIG. 3.

(25) A cleaned extruder was pre-heated to the selected processing temperature. A range of barrel temperature profiles were used, typically increasing from a cooled feed zone to a maximum mid-way along the barrel and decreasing towards the die end. For the purposes of these experiments the extruders were run without a die. Extruder screw rotation speed was set; a wide range of speeds can be achieved, up to 1000 revolutions per minute (rpm) with the extruder used here. Typical screw rotation speeds were set at between 40 and 70 rpm. A pre-mixed blend of metal salt and organic ligand reactants were then introduced into the feed hopper of the extruder. Manual dosing may prove convenient for small batch sizes (typically between 10-200 g). For larger batch sizes a gravimetric or volumetric feeder system can more conveniently be employed. The extruded product was then collected at the exit of the screws, in powder, sticky mass or molten form depending upon constituents and the set operating conditions. The collected material was subsequently analysed for metal organic compound formation.

(26) During the course of experiments, the following parameters could be adjusted: Set temperature Screw rotation speed Throughput Screw design (i.e. degree of distributive and dispersive mixing) Number of passes through the extruder Ratio of precursors Type of added solvent Amount of added solvent

(27) Inspection of the process by removal of the top of the barrel in order to view the reacting materials showed no evidence of the formation of a liquid phase.

Example 1—Zn MOF (ZIF-8)

(28) A physical mixture of basic zinc carbonate and 2-methylimidazole was prepared by mixing 40 g [ZnCO.sub.3].sub.2[Zn(OH).sub.2].sub.3 and 60 g C.sub.4H.sub.6N.sub.2 (HMIM) (molar ratio 10:1) in a cup. The Haake Rheomex extruder was used with the screw configuration detailed above, consisting primarily of forward feeding elements and a small distributive mixing zone. The barrel of the extruder was at room temperature. The physical mixture was slowly fed to the extruder at a rate of 5 g/minute and the screws were rotated at 55 rpm. The finely agglomerated product was collected at the extruder exit and then recirculated through the extruder four further times. On the fourth pass through the extruder, 8 mL of MeOH was also fed into the extruder.

(29) The resulting powder (Material 1) was collected. A 1 g sample of Material 1 was subjected to powder X-ray diffractometric (PXRD) characterisation. The X-ray diffraction pattern of the Material 1 was sufficiently similar to that calculated for the previously known metal-organic framework ZIF-8 to suggest that a reaction between the precursors had taken place to produce the metal organic framework ZIF-8. The comparative PXRD data were simulated from the single crystal X-ray diffraction data in the Cambridge Structural Database.

(30) A 2.5 g sample of Material 1 was washed and activated by immersing in 100 mL of MeOH for 20 minutes and then placed in an oven at 150° C. for 2 hours. The sample was then subjected to BET surface area analysis, giving a very high surface area of 1417 m.sup.2/g.

(31) FIG. 4 shows the PXRD patterns (simulated and experimental) obtained for material 1, alongside the theoretical PXRD pattern for known metal organic framework ZIF-8.

(32) Based on the above method, related materials can be prepared based on other metals such as ZIF-67 (by reaction of cobalt hydroxide with 2-methylimidazole), or based on other organic molecules such as ZIF-7 (by reaction between basic zinc carbonate and benzimidazole), Cu(isonicotinate).sub.2 (by reaction between isonicotinic acid and Cu(OAc).H.sub.2O), Mg(isonicotinate)2 (by reaction between Mg(OH)2 and isonicotinic acid), Li(isonicotinate) (by reaction between LiOH and isonicotinic acid) and Mn(isonicotinate)2 (by reaction between Mn(OAc).sub.2 and isonicotinic acid).

Example 2—Cu MOF (CuBTC)

(33) A physical mixture of copper acetate monohydrate and 1,3,5-benzenetricarboxylic acid was prepared by mixing 58.8 g Cu(OAc).sub.2.H.sub.2O and 41.4 g of H.sub.3BTC (molar ratio 3:2) in a cup. The Haake Rheomex extruder was used with the screw configuration detailed above, consisting primarily of forward feeding elements and a small distributive mixing zone. The barrel of the extruder was at room temperature. The physical mixture was slowly fed to the extruder at a rate of 5 g/minute and the screws were rotated at 55 rpm. The finely agglomerated product was collected at the extruder exit and then recirculated through the extruder two further times. On the second pass through the extruder, 20 mL of MeOH was also fed into the extruder.

(34) The resulting powder (Material 2) was collected. A 1 g sample of Material 2 was subjected to powder X-ray diffractometric (PXRD) characterisation. The X-ray diffraction pattern of the Material 2 was sufficiently similar to that calculated for the previously known metal-organic framework CuBTC (HKUST-1) to suggest that a reaction between the precursors had taken place to produce the metal organic framework CuBTC (HKUST-1). The comparative PXRD data were simulated from the single crystal X-ray diffraction data in the Cambridge Structural Database.

(35) A 2.5 g sample of Material 2 was washed and activated by immersing in 100 mL of EtOH for 20 minutes and then placed in an oven at 150° C. for 2 hours. The sample was then subjected to BET surface area analysis, giving a surface area of 706 m.sup.2/g.

(36) FIG. 5 shows the PXRD patterns (simulated and experimental) obtained for Material 2, alongside the theoretical PXRD pattern for known metal organic framework CuBTC (HKUST-1).

(37) Based on the above example, related materials can be prepared based on alternative metals such as Fe(BTC) (by reacting Fe(OAc).sub.3 with H.sub.3BTC) or La(BTC) (by reaction between La.sub.2(CO.sub.3).sub.3 and H.sub.3BTC) on alternative organic linkers such as MOF-74(Zn) (by reaction between basic zinc carbonate and 2,5-dihydroxyterephthalic acid), MOF-74(Mg) (by reaction between Mg(OH).sub.2 and 2,5-dihydroxyterephthalic acid), MOF-74(Co) (by reaction between Co(OH)2 and 2,5-dihydroxyterephthalic acid), MOF-74(Fe) (by reaction between Fe(OAc).sub.2 and 2,5-dihydroxyterephthalic acid), MIL-53 (by reaction between Al(OH)(OAc).sub.2 and terephthalic acid).

Example 3—Zn Complexes of 8-Hydroxyquinoline

(38) Zn-quinolinate complexes were synthesized as detailed below. Complexes were synthesized from zinc acetate dehydrate and from basis zinc carbonate. The HAAKE Rheomex PTW16 OS extruder and the ThermoFisher Process 11 extruder were used as indicated in the experimental sections below.

(39) ##STR00001##

(40) Structures of Zn-quinolinate complexes obtained by extrusion and referred to in example 3.

Example 3(i)—Synthesis from Zinc Acetate Dihydrate

(41) ##STR00002##
Method A (Haake Rheomex 16):

(42) Both reactants were pre-ground in a vibrational ball mill and sieved through industrial standard sieves (355 μm mesh). Zinc acetate dihydrate (43 g, 1.95 mol) was hand mixed with 8-hydroxyquinoline (57 g, 0.393 mol) for 5 minutes. The mixture was put in a hopper fed to the extruder barrel with a metering based feed screw at an approximate rate of 3 g/minute. The material was hand fed at an approximate rate of 3 g/min. The material was extruded at 55 rpm without applied heat to the barrel and a yellow/lime green material was collected. Analysis by PXRD showed the product to consist of a mixture of products (1) and (2).

(43) Method B (ThermoFisher Process 11):

(44) 8-hydroxyquinoline was pre-ground by hand in a large pestle and mortar, so that the diameter of the particles matched those of the zinc salt (between 1-3 mm). Zinc acetate dihydrate (43 g, 1.95 mol) was hand mixed with 8-hydroxyquinoline (57 g, 0.393 mol) for 5 minutes. The mixture was put in a hopper fed to the extruder barrel from at an exact rate of 1.33 g/minute. The hopper had a mechanical mixer in it, and a twin screw gravimetric feeder. The material was extruded at 200 rpm with the barrel temperature set at 50° C. A homogenous green material was collected Analysis by PXRD showed the product to consist of a mixture of products (1) and (2).

(45) Method C (ThermoFisher Process 11):

(46) Both reactants were pre-ground in a vibrational ball mill and sieved through industrial standard sieves (355 μm mesh). Zinc acetate dihydrate (43 g, 1.95 mol) was hand mixed with 8-hydroxyquinoline (57 g, 0.393 mol) for 5 minutes. The mixture was put in a hopper and fed to the extruder barrel from at an exact rate of 1.33 g/minute. The hopper contained mechanical mixer, which prevented aggregation of the mixture and kept it as a free-flowing powder. A twin screw gravimetric feeder designed for powder feeding was used. The material was extruded at 200 rpm with of the barrel temperature set at 50° C. A homogenous green material was collected. Analysis by PXRD showed the product to consist of a mixture of products (1) and (2).

Example 3(ii)—Synthesis from Basic Zinc Carbonate

(47) ##STR00003##
Method A (Haake Rheomex 16):

(48) 8-hydroxyquinoline was pre-ground in a vibrational ball mill and both reactants sieved (355 μm mesh). Basic zinc carbonate (20.55 g, 0.0374 mol) was added to 8-hydroxyquinoline (54.44 g, 0.375 mol) and hand mixed for 5 minutes. The mixture was put in a hopper fed to the extruder barrel with a metering based feed at an approximate rate of 3 g/minute. The material was extruded at 200 rpm with the barrel temperature set at 50° C. After collecting an initial 5-10 g of a feint yellow powder, a mustard yellow, flaky material was collected. Analysis by PXRD showed it to consist of product (1).

(49) Method C (ThermoFisher Process 11):

(50) The 8-hydroxyquinoline reactant was pre-ground in a vibrational ball mill and both reactants sieved (355 μm mesh). Basic zinc carbonate (20.55 g, 0.0374 mol) was added to 8-hydroxyquinoline (54.44 g, 0.375 mol) and hand mixed for 5 minutes. The mixture was placed in a hopper and fed to the extruder barrel at an exact rate of 1.33 g/minute. The hopper contained mechanical mixer, which prevented aggregation of the mixture and kept it as a free-flowing powder. A twin screw gravimetric feeder designed for powder feeding was used. The material was extruded at 200 rpm with the barrel temperature set to 50° C. After collecting about 5-10 g of the faint yellow powder, a mustard yellow, flaky material was collected. Analysis by PXRD showed it to consist of product (1).

(51) Based on the above example related complexes can be prepared such as Al(8-quinolinate).sub.3 (by reaction between Al(OH)(OAc).sub.2 and 8-hydroxyquinoline or Mg((8-quinolinate).sub.2 (by reaction between Mg(OH)2 and 8-hydroxyquinoline).

(52) TABLE-US-00001 TABLE 1 metal linker(s) MOF 1 Zn 2-methyl imidazole Zn(Me-im).sub.2 ZIF-8 2 Zn 2-ethylimidazole 3 Zn benzimidazole ZIF-7 4 Zn trans-1,4-butene dicarboxylic acid Zn.sub.2(fumarate).sub.2(dabco) or (fumaric acid) Zn.sub.2(fumarate).sub.2(bipyridine) and dabco/4,4′-bipyridine or 5 Co 2-methyl imidazole Co(Me-im).sub.2 ZIF-67 6 Mg Isonicotinic acid Mg(INA).sub.2 7 Cu Isonicotinic acid Cu(INA).sub.2 8 Al 1,4-benzenedicarboxylic acid Al(bdc)OH (terephthalic acid) MIL-53 9 Lanthanide 1,3,5-benzenetricarboxylic acid Ln(btc) 10 Cu 1,3,5-benzenetricarboxylic acid Cu.sub.3(btc).sub.2 HKUST-1 11 Fe 1,3,5-benzenetricarboxylic acid Fe(BTC) 12 Li Isonicotinic acid Li(INA) 13 Sc 1,4-benzenedicarboxylic acid Sc(terephthalate) (terephthalic acid) 14 Mn Isonicotinic acid Mn(INA).sub.2 15 Cr 1,4-benzenedicarboxylic acid MIL-101 (terephthalic acid) 16 Ti 1,4-benzenedicarboxylic acid MIL-125 (terephthalic acid) 17 Zn 2,5-dihydroxybenzene1,4- MOF-74 (Zn) dicarboxylic acid 18 Mg 2,5-dihydroxybenzene1,4- MOF-74 (Mg) dicarboxylic acid 19 Co 2,5-dihydroxybenzene1,4- MOF-74 (Co) dicarboxylic acid 20 Fe 2,5-dihydroxybenzene1,4- MOF-74 (Fe) dicarboxylic acid

Examples 4 to 10

(53) The HAAKE RHEOMEX PTW16 OS extruder was used in Examples 4 to 10 below. The screw speed was set at 55 rpm. The effect of the temperature on the synthesis of MOFs was evaluated by increasing the temperature of the five heated zones of the barrel from room temperature (25° C.) to 150° C. The reagents were pre-mixed and manually fed afterwards, using the first feed port at an addition rate of approximately 5 g/minute. The effect of liquid-assisted grinding was evaluated by manual addition of absolute MeOH to the solid mixture. The MOFs were activated with absolute EtOH, MeOH or H.sub.2O, as detailed below. The solid products were recovered by vacuum filtration and dried at 150° C. for 2 h in a Carbolite PF60 furnace (serial number 20-601895).

Example 4(i)—Cu3(BTC)2

(54) 41.05 g of Cu(OH).sub.2 (0.42 mol) and 58.95 g of 1,3,5-benzenetricarboxylic acid (0.28 mol) were pre-mixed in a cup. 30 mL of MeOH were added to the mixture and the resulting solid was passed through the extruder at room temperature. Finally, 30 mL more of MeOH were added to the mixture and the solid was extruded at room temperature a second time. The XRD patterns of the extruded materials confirmed the formation of CuBTC, even for the material that had only been extruded with 30 mL of MeOH. Activation of CuBTC was carried out by washing 1 g of the blue MOF with 40 mL of absolute ethanol for 20 min (×3). BET analysis confirmed the high surface area of the activated product (1324 m.sup.2/g).

Example 4(ii)—Alternative Synthesis of CuBTC Using Copper Acetate

(55) 58.8 g of Cu(OAc).sub.2.H.sub.2O (0.30 mol) and 41.2 g of 1,3,5-benzenetricarboxylic acid (0.20 mol) were pre-mixed in a cup. The solvent-free mixture was passed through the extruder at room temperature while 20 mL of MeOH were added at a rate of 1 mL/min using a second feed port. Finally, the mixture was passed through the extruder one last time without adding any more MeOH. XRD analysis of the extruded materials confirmed the formation of the CuBTC MOF. BET analysis of the activated product with absolute ethanol confirmed the high surface area of the MOF (706 m.sup.2/g).

Example 5(i)—Synthesis of ZIF-8

(56) 30.76 g of [ZnCO.sub.3].sub.2[Zn(OH).sub.2].sub.3 (0.056 mol) and 69.24 g of 2-methylimidazole (0.84 mol) were pre-mixed in a cup. The solid mixture was then passed through the extruder at 150° C. The solid sample was then passed through the extruder a second time at 150° C. The XRD patterns of the extruded materials confirmed the formation of ZIF-8, even for the material that had only been extruded once. Activation of the samples was carried out by washing 2.5 g of ZIF-8 with 50 mL of methanol for 20 min (×3) in order to remove the unreacted excess of 2-methylimizadole.

Example 5(ii)—Synthesis of ZIF-8

(57) Alternative synthesis of ZIF-8 at room temperature was also investigated. Liquid-assisted grinding (LAG) with methanol was carried out. The same solid mixture was passed through the extruder while 7 mL of MeOH were added using a second port. Finally, the solid mixture was passed through the extruder at room temperature a third time. The XRD analysis confirmed the formation of the MOF and BET analysis of the activated product confirmed the high surface area of ZIF-8 (1614 m.sup.2/g). Excess of 2-methylimidazole was used in the synthesis of ZIF-8 because previous work had showed that lower surface areas were obtained when stoichiometric quantities were used. Synthesis of ZIF-8 by extrusion at 150° C. using stoichiometric quantities (40 g of [ZnCO.sub.3].sub.2[Zn(OH).sub.2].sub.3 (0.073 mol) and 60 g of 2-methylimidazole (0.730 mol), resulted in ZIF-8 with a surface area of 1253 m.sup.2/g.

Example 6—Synthesis of ZIF-67

(58) 36.15 g of Co(OH).sub.2, m.p. 168° C. (0.39 mol) and 63.85 g of 2-methylimidazole, m.p. 144° C. (0.78 mol) were pre-mixed in a cup and the solvent-free mixture was passed through the extruder at 150° C. The solid product was then extruded again a second time at 150° C. The XRD patterns of the extruded materials (even for the product extruded once) exhibited the characteristic diffraction peaks of ZIF-67, confirming the formation of the MOF.

(59) ZIF-67 was activated by washing 2.5 g of the purple MOF with 50 mL of MeOH for 20 min (×3). The XRD pattern of the activated product did not show any significant differences compared to the material obtained directly from the extruder. The BET analysis of the activated product confirmed its high surface area (1232 m.sup.2/g). It should be noted that the characteristic diffraction peaks of ZIF-67 were not present on the XRD pattern of the extruded product when the same solid mixture was extruded at room temperature. However, upon activation with MeOH, the diffraction peaks corresponding to the MOF were detected, confirming the formation of ZIF-67.

Example 7—Synthesis of Mg-MOF-74

(60) 37.06 g of Mg(OH).sub.2 (0.64 mol) and 62.94 g of 2,5-dihydroxibenzene-1,4-dicarboxylic acid (0.32 mol) were pre-mixed in a cup. 10 mL of MeOH were added to the solid mixture while it was stirred with a spatula and the resulting solid was passed through the extruder at room temperature. 10 more mL of MeOH were then added to the extruded solid while stirring with a spatula and the resulting solid mixture was passed through the extruder at room temperature a second time. Finally, 10 more mL of MeOH were added to the solid mixture and the resulting solid powder was passed through the extruder at room temperature a third time. PXRD analysis of the product confirmed the formation of Mg-MOF-74. Mg-MOF-74 was activated by washing 1 g of the yellow MOF with 60 mL of degassed MeOH for 18 h and filtered under N.sub.2. The BET analysis of the activated product confirmed its high surface area (684 m.sup.2/g).

Example 8—Synthesis of Co-MOF-74

(61) 48.41 g of Co(OH).sub.2 (0.52 mol) and 51.59 g of 2,5-dihydroxibenzene-1,4-dicarboxylic acid (0.26 mol) were pre-mixed in a cup. 10 mL of MeOH were added to the cup containing the solid mixture while it was stirred with a spatula and then the solid mixture was passed through the extruder at room temperature. 10 more mL of MeOH were then added to the mixture while stirring with a spatula and the resulting solid was passed through the extruder at room temperature a second time. Finally, 10 more mL of MeOH were added to the solid mixture and the resulting solid was passed through the extruder at room temperature a third time. XRD analysis of the product confirmed the formation of Co-MOF-74. Activation of the MOF was carried out by washing 2.5 g of Co-MOF74 with 50 mL of MeOH for 20 min (×3). However, the XRD pattern of the activated MOF did not show any significant differences compared to the material obtained directly from the extruder.

Example 9—Synthesis of Zn-MOF-74

(62) 52.48 g of [ZnCO.sub.3].sub.2[Zn(OH).sub.2].sub.3 (0.096 mol) and 47.52 g of 2,5-dihydroxibenzene-1,4-dicarboxylic acid (0.240 mol) were pre-mixed in a cup. 10 mL of MeOH were added to the cup containing the solid mixture while it was stirred with a spatula and the resulting solid was passed through the extruder at room temperature. 10 more mL of MeOH were then added to the solid while stirring with a spatula and the solid mixture was passed through the extruder at room temperature a second time. Finally, 10 more mL of MeOH were added to the solid while stirring with a spatula and the resulting solid was passed through the extruder at room temperature a third time. XRD analysis of the product confirmed the formation of Zn-MOF-74. Activation of the MOF was carried out by washing 2.5 g MOF with 50 mL of MeOH for 20 min (×3). However, the XRD pattern of the activated MOF did not show any significant differences compared to the material obtained directly from the extruder.

Example 10—Synthesis of Al(OH) Fumarate

(63) 74.48 g of Al.sub.2(SO.sub.4).sub.3.18H.sub.2O (0.11 mol), 25.94 g of fumaric acid (0.22 mol) and 26.64 g of NaOH pellets (0.66 mol) were pre-mixed in a cup and then the solvent-free mixture was passed through the extruder at room temperature. After that, the solid was passed through the extruder at room temperature a second time without adding any solvent. Finally, the solid was the solid was passed through the extruder at room temperature a third time without adding any solvent. The XRD patterns of the materials passed through the extruder twice and three times showed the characteristic diffraction peaks of Al(OH)fumarate, confirming the formation of the MOF. However, Na.sub.2SO.sub.4 (formed as a biproduct) was also detected on the XRD patterns. Activation of the MOF was carried out by washing 1 g of product with 30 mL of H.sub.2O for 20 min (×3). The XRD pattern of the activated product showed only the diffraction peaks corresponding to Al(OH)fumarate, confirming that the Na.sub.2SO.sub.4 had been removed. High surface area of the activated Al(OH)fumarate MOF prepared by extrusion was confirmed by BET analysis (1010 m.sup.2/g). It should be noted that when the same mixture of solids was passed through the extruder at 150° C., the characteristic diffraction peaks of the aluminium MOF were detected even for the material extruded once. In addition, further work showed that the process could be optimised. Higher feed rates (10 g/min) were achieved by increasing the screw speed up to 95 rpm and by using NaOH pearls. BET analysis of the activated material confirmed the high surface area of the MOF produced even when activated in large scale (945 m.sup.2/g for the product activated in 14 g scale).

Example 11—Synthesis of ZIF-8 at 150° C.

(64) Basic zinc carbonate, [ZnCO.sub.3].sub.2.[Zn(OH).sub.2].sub.3 (30.81 g, 0.056 moles) and 2-methylimidazole (69.18 g, 0.84 moles) were physically mixed together (Molar ratio 1:15). These were manually fed into the Haake Rheomex OS PTW16 at a range of speeds—55, 75 and 95 rpm. The screws consisted mainly of forward conveying sections and two kneading sections. The barrel of the extruder was set at 150° C. A beige molten extrudate was collected from each experiment that solidified quite quickly upon cooling to room temperature. The extrudate was extruded at the same speed a further two times, however the second extrusion was quite difficult to feed due to the shaped ‘clumps’ formed upon cooling. Throughput rates from the first extrusion were determined and are outlined in Table 2.

(65) TABLE-US-00002 TABLE 2 Screw Speed (rpm) Throughput Time (mins) Throughput Rate (kg/hr) 55 18 0.33 75 10 0.60 95 6 1.00

(66) PXRDs of the as-synthesised ZIF-8 extrudates were sufficiently similar to the simulated PXRD pattern of ZIF-8 obtained from the single crystal X-ray diffraction data in the Cambridge Structural Database. PXRD traces indicated a complete reaction following the first extrusion.

(67) Activation was carried out by stirring in HPLC grade methanol (400 mL) at room temperature for 2 hours. The suspension was filtered to obtain a white solid. This was stirred at room temperature in HPLC methanol for a further 2 hours and filtered. The white solid was then dried in an oven at 150° C. for 2 hours. PXRD analysis provided traces matching that of the simulated PXRD pattern of ZIF-8 obtained from the single crystal X-ray diffraction data in the Cambridge Structural Database (FIG. 6). TGA and CHNS analysis also indicated complete reactions at each speed, even after one extrusion.

Example 12—Synthesis of ZIF-8 at 200° C.

(68) Basic zinc carbonate, [ZnCO.sub.3].sub.2.[Zn(OH).sub.2].sub.3 (30.81 g, 0.056 moles) and 2-methylimidazole (69.18 g, 0.84 moles) were physically mixed together (Molar ratio 1:15). These were manually fed into the Haake Rheomex OS PTW16, at a screw speed of 95 rpm. The screws consisted mainly of forward conveying sections and two kneading sections. The barrel of the extruder was set at 200° C. A beige molten extrudate was collected from each experiment that solidified quite quickly upon cooling to room temperature. In total 4.5 minutes was required to extrude the reagents and collect the extrudate therefore the throughput rate was determined to be 1.33 kg/hr. Only one extrusion was carried out as previous experiments showed that a complete reaction was obtained after one extrusion. Due to the high temperatures of the experiment, the 2-methylimidazole was observed to have formed a resistant polymer covering the surface of the screws that was difficult to remove.

(69) PXRD of the as-synthesised ZIF-8 was sufficiently similar to the simulated PXRD pattern of ZIF-8 obtained from the single crystal X-ray diffraction data in the Cambridge Structural Database.

(70) Activation was carried out by stirring in HPLC grade methanol (400 mL) at room temperature for 2 hours. The suspension was filtered to obtain a white solid. This was stirred at room temperature in HPLC methanol for a further 2 hours and filtered. The white solid was then dried in an oven at 150° C. for 2 hours. PXRD analysis provided traces matching that of the simulated PXRD pattern of ZIF-8 obtained from the single crystal X-ray diffraction data in the Cambridge Structural Database (FIG. 7).

Example 13—Synthesis of ZIF-8 on the Kilo Scale

(71) Basic zinc carbonate, [ZnCO.sub.3].sub.2.[Zn(OH).sub.2].sub.3 (308.1 g, 0.56 moles) and 2-methylimidazole (691.8 g, 8.4 moles) were physically mixed together in one batch (Molar ratio 1:15). This was manually fed into the Haake Rheomex extruder, with a screw speed of 95 rpm. The screws consisted mainly of forward conveying sections and two kneading sections. The barrel of the extruder was set at 200° C. A molten extrudate was produced and it was collected in 5 approximately equal batches to determine homogeneity. The reagents were extruded once only.

(72) PXRD of the as-synthesised extrudates (batches A-E) showed homogeneity and all the traces were very similar to that of the simulated pattern obtained from the single crystal X-Ray structure as provided by the Cambridge Structural Database.

(73) Activation was carried out by stirring a 5 g sample in 40 mL HPLC grade methanol for 2 hours. This was filtered to produce a white powder that was again immersed in solvent and stirred for a further 2 hours. The suspension was filtered and the resulting solid was oven-dried at 150° C. for 2 hours. PXRD of the activated product was very similar to the simulated PXRD trace obtained for ZIF-8 (FIG. 8).

Example 14—Synthesis of Cu3(BTC)2

(74) Copper (II) hydroxide (0.43 moles, 42.0 g), Cu(OH).sub.2 and benzene-1, 3, 5-tricarboxylic acid (58.0 g, 0.286 moles) were physically mixed together (Molar ratio 3:2). HPLC grade methanol was added slowly and the mixture was stirred. Heat was produced from the addition of the solvent and the mixed solid became a darker green in colour. These were manually fed into the Haake Rheomex extruder, at a range of screw speeds—55, 75, 95, 115, 135, 155 and 250 rpm. The screws consisted mainly of forward conveying sections and two kneading sections. The barrel of the extruder was kept at room temperature. A light blue extrudate paste was produced which formed large clumps after the first extrusion. These were broke down and a further 20 mL of MeOH was mixed into the extrudate. This was fed through the extruder a second time to produce a blue powder extrudate which was extruded a third time without extra MeOH addition. Throughput rates from the first extrusion were determined and are outlined in Table 3.

(75) TABLE-US-00003 TABLE 3 Screw Speed (rpm) Throughput Time (mins) Throughput Rate (kg/hr) 55 20 0.30 75 18 0.33 95 14 0.43 115 12 0.50 135 10 0.60 155 9 0.66 250 6 1.00

(76) PXRD of the as-synthesised extrudates indicated a complete reaction as the traces were very similar to that of the simulated trace produced from the single X-Ray crystal structure provided by the Cambridge Structure Database. Complete reactions can be suggested after the first extrusion.

(77) Activation of Extrudates:

(78) Four methods were employed to activate the Cu.sub.3(BTC).sub.2 extrudates.

(79) Method 1: 8 mL of absolute ethanol per 1 g of extrudate was used. The extrudate was immersed in absolute ethanol and sonicated in an ultrasonic cleaning bath for 20 minutes. The suspension was filtered. This process was repeated a further two times and a darkening of the blue colour was observed. The solid product was oven-dried at 150° C. for 2 hours. A dark purple solid was produced.

(80) Method 2: 8 mL of absolute ethanol per 1 g of extrudate was used. The extrudate was immersed in absolute ethanol and stirred for 20 minutes at room temperature. The suspension was then filtered and the process repeated a further two times. Again the darkening of the solid colour can be observed. The solid was oven-dried at 150° C. for 2 hours to produce a dark purple solid.

(81) Method 3: 8 mL of industrial alcohol (99.9% ethanol) per 1 g of extrudate was used. The extrudate was immersed in absolute ethanol and sonicated in an ultrasonic cleaning bath for 20 minutes. The suspension was filtered. This process was repeated a further two times and a darkening of the blue colour was observed. The solid product was oven-dried at 150° C. for 2 hours. A dark purple solid was produced.

(82) Method 4: 8 mL of industrial alcohol (99.9% ethanol) per 1 g of extrudate was used. The extrudate was immersed in absolute ethanol and stirred for 20 minutes at room temperature. The suspension was then filtered and the process repeated a further two times. Again the darkening of the solid colour can be observed. Oven-drying at 150° C. for 2 hours produced a dark purple solid.

(83) PXRDs of these activated products provided traces suitably matching that of the simulated PXRD trace obtained from the Cambridge Structure Database (FIG. 9).

Example 15—Synthesis of Cu3(BTC)2 (Varying Methanol % Wt)

(84) Copper (II) hydroxide (0.43 moles, 42.0 g), Cu(OH).sub.2 and benzene-1, 3, 5-tricarboxylic acid (58.0 g, 0.286 moles) were physically mixed together (Molar ratio 3:2). Varying amounts of HPLC grade methanol (40 mL, 60 mL, 80 mL, 100 mL and 120 mL) were added slowly in each experiment and the mixture was stirred. Heat was produced from the addition of the solvent and the mixed solid became a darker green in colour for the mixtures in which more than 60 mL of methanol was added. These were manually fed into the Haake Rheomex extruder, with a screw of length:diameter ratio of 25 twin screw extruder at 135 rpm. The screws consisted mainly of forward conveying sections and two kneading sections. The barrel of the extruder was kept at room temperature. A light blue powder extrudate was produced except for the experiment with 40 mL of methanol which produced a green extrudate. PXRD of the as-synthesised extrudates suggest complete reaction upon addition of 60-120 mL methanol. The PXRD of the experiment employing 40 mL of methanol showed the presence of Cu(OH).sub.2 and was therefore unsuccessful. Activation was carried out via Method 2 outlined above to produce dark purple powders from the experiments involving 60 mL or more of solvent. PXRD of the activated products were sufficiently similar to the simulated PXRD trace provided by the Cambridge Structure Database.

Example 16—Synthesis of Cu3(BTC)2 (Varying Industrial Alcohol % Wt)

(85) Copper (II) hydroxide (0.43 moles, 42.0 g), Cu(OH).sub.2 and benzene-1, 3, 5-tricarboxylic acid (58.0 g, 0.286 moles) were physically mixed together (Molar ratio 3:2). Varying amounts of industrial alcohol (99.9% ethanol) (40 mL, 60 mL, 80 mL, 100 mL and 120 mL) were added slowly in each experiment and the mixture was stirred. Heat was produced from the addition of the solvent and the mixed solid became a darker green in colour for the mixtures in which more than 60 mL of industrial alcohol was added. These were manually fed into the ThermoFisher Process 11, at a screw speed of 135 rpm. The screws consisted mainly of forward conveying sections and two kneading sections. The barrel of the extruder was kept at room temperature. A light blue powder extrudate was produced, however the experiment employing 40 mL of industrial alcohol produced a green extrudate.

(86) PXRD of the as-synthesised extrudates suggest complete reaction upon addition of 60-120 mL industrial alcohol. The PXRD of the experiment employing 40 mL of industrial alcohol showed the presence of Cu(OH).sub.2 and was therefore unsuccessful.

(87) Activation was carried out via Method 4 outlined above to produce dark purple powders from the experiments involving 60 mL or more of solvent. PXRD of the activated products were sufficiently similar to the simulated PXRD trace provided by the Cambridge Structure Database.

Example 17—Synthesis of Cu3(BTC)2 on the Kilo Scale

(88) Copper (II) hydroxide (4.30 moles, 420.0 g), Cu(OH).sub.2 and benzene-1, 3, 5-tricarboxylic acid (580.0 g, 0.2.86 moles) were physically mixed together (Molar ratio 3:2). 400 mL of methanol was added slowly to the reagent mixture, heat was produced from the addition of the solvent and the mixed solid became a darker green in colour. This was manually fed into the Haake Rheomex extruder, at a screw speed of 135 rpm. The screws consisted mainly of forward conveying sections and two kneading sections. The barrel of the extruder was kept at room temperature. A light blue powder extrudate was produced and collected in 5 batches to check for homogeneity. PXRD of the as-synthesised extrudates (batches A-E) showed homogeneity and all the traces were very similar to that of the simulated pattern obtained from the single crystal X-Ray structure as provided by the Cambridge Structural Database.

(89) Activation of 50 g was carried out via Method 2 to produce a dark purple solid after oven-drying at 150° C. for 2 hours. PXRD of the activated product produced a trace that was matching to the simulated trace obtained from the Cambridge Structure Database (FIG. 10).

Example 18—Synthesis of Cu3(BTC)2 with Reduced Residence Times

(90) Copper (II) hydroxide (0.43 moles, 42.0 g), Cu(OH).sub.2 and benzene-1, 3, 5-tricarboxylic acid (58.0 g, 0.286 moles) were physically mixed together (Molar ratio 3:2). Industrial alcohol (99.9% ethanol), 80 mL, was added slowly and the mixture was stirred. Heat was produced from the addition of the solvent and the mixed solid became a darker green in colour. These were manually fed into the ThermoFisher Process 11 Parallel Twin Screw Extruder, with a screw speed of 155 and 250 rpm. The screws consisted mainly of forward conveying sections and only one kneading section. The residence time was measured to be ca. 12 seconds at 155 rpm and ca. 6 seconds at 250 rpm. The barrel of the extruder was kept at room temperature. A light blue extrudate powder was produced. PXRD of the as-synthesised extrudates suggest a complete reaction in both cases as the traces are very similar to the simulated trace produced by the Cambridge Structure Database. Activation was carried out via Method 4 to produce dark purple powders in both cases. PXRD of the activated products were sufficiently similar to the simulated PXRD trace provided by the Cambridge Structure Database (FIG. 11).

Example 19—Synthesis of Cu3(BTC)2 with Reduced Residence Times

(91) Copper (II) hydroxide (0.43 moles, 42.0 g), Cu(OH).sub.2 and benzene-1, 3, 5-tricarboxylic acid (58.0 g, 0.286 moles) were physically mixed together (Molar ratio 3:2). Industrial alcohol (99.9% ethanol), 80 mL, was added slowly and the mixture was stirred. Heat was produced from the addition of the solvent and the mixed solid became a darker green in colour. These were manually fed into a ThemoFisher Process 11 Extruder, with a screw speed of 155 and 250 rpm. The mixture was fed into the last conveying section of the screw. The residence time was measured to be ca. 3-4 seconds at 155 rpm and ca. 1-2 seconds at 250 rpm. The barrel of the extruder was kept at room temperature. A light blue extrudate powder was produced. PXRD of the as-synthesised extrudates suggest a complete reaction in both cases as the traces are very similar to the simulated trace produced by the Cambridge Structure Database. Activation was carried out via Activation Method 4 to produce dark purple powders in both cases. PXRD of the activated products were sufficiently similar to the simulated PXRD trace provided by the Cambridge Structure Database (FIG. 12).

Example 21—Synthesis of Alq.AcOH

(92) Basic aluminium diacetate (8.1 g, 0.049 moles) and 8-hydroxyquinoline (22.65 g, 0.156 moles) were physically mixed together (Molar ratio 1:3). These were manually fed into a ThermoFisher Process 11 Extruder, at a screw speed of 55 rpm (residence time ca. 1.5-2 minutes). A dark yellow solid was produced. PXRD of the as-synthesised extrudate suggest a complete reaction in both cases as the traces are very similar to the simulated trace produced by the Cambridge Structure Database (FIG. 13). Excess acetic acid could be removed via heating at 200° C. for 2.0 hours to produce a bright yellow solid.

Example 22—Synthesis of [Ni(NCS)2(PPh3)2]

(93) Nickel (II) thiocyanate (5 g, 0.028 moles) and triphenylphosphine (15 g, 0.0572 moles) were physically mixed together (Molar ratio 1:2). To this, 0.4 equivalents of HPLC grade methanol was added (0.0112 moles, 0.57 mL). This paste was manually fed into a ThermoFisher Process 11 Extruder, at a screw speed of 55 rpm (residence time ca. 1.5-2 minutes). An orange solid was produced. PXRD of the as-synthesised extrudate suggest a complete reaction in both cases as the traces are very similar to the simulated trace produced by the Cambridge Structure Database (FIG. 14).

Example 23—Synthesis of [Ni(Salen)]

(94) Nickel (II) acetate tetrahydrate (9.27 g, 0.037 moles) and salenH.sub.2 (2,2′-[1,2-Ethanediylbis[(E)-nitrilomethylidyne]]bis-phenol) (10 g, 0.037 moles) were physically mixed together (Molar ratio 1:1). To this 0.3 equivalents of HPLC grade methanol was added (0.0111, 0.449 mL). This paste was manually fed into the ThermoFisher Process 11 Extruder, with a screw speed of 55 rpm (residence time ca. 1.5-2 minutes). A brick red solid was produced. PXRD of the as-synthesised extrudate suggest a complete reaction in both cases as the traces are very similar to the simulated trace produced by the Cambridge Structure Database (FIG. 15).

Example 24—Synthesis of ZIF-8 on the Kilo Scale Via Single Screw Extrusion

(95) Basic zinc carbonate, [ZnCO.sub.3].sub.2.[Zn(OH).sub.2].sub.3 (308.1 g, 0.56 moles) and 2-methylimidazole (691.8 g, 8.4 moles) were physically mixed together in one batch (Molar ratio 1:15). This was manually fed into a Dr. Collin E 25M single screw extruder with a l/d ratio of 25 at a speed of 30 rpm. A 25 mm diameter PTFE screw of constantly increasing root diameter was used. The screw consisted essentially of a conveying section and a short kneading section in the final zone. FIG. 16 shows the PTFE screw used in the experiment, highlighting the constantly increasing root diameter (top image) and the kneading section (bottom image). There were 5 zones making up the barrel, each set at different temperatures, Zone 1 i.e. the feeding zone was kept at 30° C. Zone 2 was kept at 50° C., Zone 3 at 130° C. and the final two zones at 150° C. The product emerged from the extruder as a beige solid suspended in the excess liquid 2-methylimidazole. This solidified upon cooling. The product was collected as one batch. The reagents were extruded once only. Several PXRD patterns of the as-synthesised extrudate were determined and showed homogeneity within the batch. All the traces were very similar to that of the simulated pattern of ZIF-8 obtained from the Cambridge Crystallographic Data Centre (FAWCEN), there were some differences between them and the simulated powder pattern for ZIF-8, but this was as a result of the excess 2-methylimidazole being occluded in the pores of the resulting MOF.

(96) Activation was carried out by stirring a 5 g sample in 40 mL HPLC grade methanol for 2 hours. This was filtered to produce a white powder that was again immersed in solvent and stirred for a further 2 hours. The suspension was filtered and the resulting solid was oven-dried at 150° C. for 2 hours. PXRD of the activated product was very similar to the simulated PXRD trace obtained for ZIF-8 (FIG. 17).