WATER CAPTURE

Abstract

A method of capturing water from a gaseous composition comprising water vapour (suitably air), the method comprising: (a) providing a metal-organic material; and (b) contacting themetal-organic material with water and/or water vapour; wherein upon contact with water and/or water vapour the material switches from a first state to a second state wherein the second state is able to retain a higher amount of water than the first state.

Claims

1. A method of capturing water from a gaseous composition comprising water vapour (suitably air), the method comprising: (a) providing a metal-organic material; and (b) contacting the metal-organic material with water and/or water vapour; wherein upon contact with water and/or water vapour the material switches from a first state to a second state wherein the second state is able to retain a higher amount of water than the first state.

2. (canceled)

3. A metal-organic material wherein said material can exist in a first state and a second state; wherein switching from said first state to said second state occurs upon contact of the material with water and/or water vapour; and wherein said second state is able to retain a higher amount of water than said first state.

4. A device for capturing water from a gaseous composition comprising water vapour (suitably air), the device comprising a metal-organic material and a support; wherein the metal-organic material can exist in a first state and a second state; wherein switching from said first state to said second state occurs upon contact of the material with water and/or water vapour; and wherein said second state is able to retain a higher amount of water than said first state.

5. The method of claim 1, wherein the metal-organic material comprises metal species and ligands.

6. The method of claim 5 wherein the metal species is selected from copper, cobalt, nickel, iron, zinc, cadmium, zirconium, magnesium, calcium and aluminium.

7. The method of claim 1, wherein the ligands are selected from bidentate nitrogen ligands, nitrogen-carboxylate ligands and polycarboxylate ligands.

8. The method of claim 7 wherein the ligands are selected from 4,4′-bipyridine (L1), 1,4-bis(4-pyridyl)benzene (L2), 4,4′-(2,5-dimethyl-1,4-phenylene)dipyridine (L3), 1,4-bis(4-pyridyl)biphenyl (L4), 1,2-di(pyridine-4-yl)-ethene (L5), benzotriazole-5-carboxylic acid (L128), 2,4-pyridinedicarboxylic acid (L80), glutaric acid (L141) and benzene-1,4-dicarboxylic acid (L156).

9. The method of claim 1, wherein the metal-organic material further comprises one or more anions.

10. The method of claim 9 wherein the anions are selected from BF.sub.4.sup.−, NO.sub.3.sup.−, CF.sub.3SO.sub.3.sup.− and glutarate.

11. The method of claim 1, wherein switching from a first state to a second state occurs when a threshold humidity is reached.

12. The method of claim 1, wherein the metal-organic material is a porous metal-organic framework material comprising pores which have a hydrophobic pore window and a hydrophilic internal pore surface.

13. The method of claim 12, wherein the porous metal-organic framework material is a microporous material.

14. The method of claim 12, wherein the porous metal-organic framework material is selected from [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)], [Cu.sub.2(glutarate).sub.2(1,2-di(pyridine-4-yl)-ethene)], [Co.sub.3(μ.sub.3-OH).sub.2(2,4-pyridinedicarboxylate).sub.2], [Mg.sub.3(μ.sub.3-OH).sub.2(2,4-pyridinedicarboxylate).sub.2], [Co.sub.3(μ.sub.3-OH).sub.2(benzotriazolate-5-carboxylate).sub.2] and [Zr.sub.12O.sub.8(μ.sub.3-OH).sub.8(μ.sub.2-OH).sub.6(benzene-1,4-dicarboxylate).sub.9].

15. The method of claim 14 wherein the porous metal-organic framework material is [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)].

16. The method of claim 1, wherein the metal-organic material is a two-dimensional layered material.

17. The method of claim 16, wherein the two-dimensional layered material is selected from sql-3-Cu—BF.sub.4, sql-2-Cu—BF.sub.4, sql-2-Cu-OTf, sql-1-Cu—NO.sub.3, sql-A14-Cu—NO.sub.3, sql-1-Co-NO.sub.3 and sql-1-Ni—NO.sub.3.

18. The method of claim 1, wherein step (b) involves contacting the metal-organic material with ambient air of sufficient humidity to cause an increase in the amount of water the material is able to hold within its structure.

19-21. (canceled)

22. The method of claim 1, further comprising: (c) transporting and/or storing the metal-organic material.

23. The method of claim 1, further comprising: (d) applying a stimulus to the metal-organic material to effect desorption of water retained therein.

24. The method of claim 23, further comprising: (e) collecting desorbed water.

Description

[0239] The invention will now be further described by reference to the accompanying figures and examples.

[0240] In the following examples, powder X-ray diffraction (PXRD) measurements were taken using microcrystalline samples using a PANalytical Empyrean™ diffractometer equipped with a PIXcel3D detector. The variable temperature powder X-ray diffraction (VT-PXRD) measurements were collected using a Panalytical X'Pert diffractometer.

[0241] Single crystal X-ray diffraction (SCXRD) measurements were also collected on a number of compounds. The data was collected using a Bruker D8 Quest diffractometer.

[0242] Thermogravimetric analysis (TGA) was carried out under nitrogen using the instrument TA Q50 V20.13 Build 39 and data was collected in the high resolution dynamic mode.

[0243] Fourier Transform Infrared (FT-IR) spectra were measured on a Perkin Elmer spectrum 200 spectrometer.

[0244] Low-pressure N.sub.2 adsorption measurements were performed on approximately 200 mg of sample using ultra-high purity grade N.sub.2. The measurements were collected using a Micrometrics TriStar II PLUS and a Micrometrics 3 Flex was used to analyse the surface area and pore size.

[0245] Vacuum dynamic vapour sorption (DVS) studies made use of a Surface Measurement Systems DVS Vacuum, which gravimetrically measures the uptake and loss of vapour. The DVS methods were used for the determination of water vapour sorption isotherms using approximately 15 to 30 mg of sample. Pure water was used as the adsorbate for these measurements and temperature was maintained by enclosing the system in a temperature-controlled incubator.

Water Adsorption Isotherm Classification

[0246] Preliminary evaluation of sorption performance in either adsorption or desorption events of sorbents is conducted by obtaining sorption isotherms. The isotherm reveals the amount of adsorbate (in this case water vapour) adsorbed and/or desorbed across a range of relative humidities (RHs) at a given temperature. FIG. 1 illustrates four types of water sorption. Such isotherms can be obtained using the instruments and methods known to those skilled in the art. Metal-organic materials for use in the present invention desirably have an isotherm as shown by line (c) of FIG. 1.

[0247] Examples 1 to 7 which follow are examples two-dimensional layered materials of the present invention.

[0248] The remaining examples relate to embodiments in which the metal-organic materials are porous metal-organic framework material comprising pores which have a hydrophobic pore window and a hydrophilic internal pore surface.

EXAMPLE 1: sql-2-Cu—BF.SUB.4

[0249] Synthesis of sql-2-Cu—BF.sub.4

[0250] An ethanol solution (3.0 ml) containing 1,4-bis(4-pyridyl)benzene (11.6 mg, 0.05 mmol) was slowly layered on an aqueous solution (3.0 ml) of copper(II) tetrafluoroborate (6 mg, 0.025 mmol) at room temperature. The resulting green crystals were collected by filtration with a yield of approximately 60%.

Structure of sql-2-Cu—BF.sub.4

[0251] sql-2-Cu—BF.sub.4 forms a two-dimensional layered network with Cu.sup.2+ ions connected in one and two dimensions by 1,4-bis(4-pyridyl)benzene to form a square lattice shown in FIG. 2A. The square lattice layers are stacked above one another with an interlayer separation of 4.112 Å shown in FIG. 2B. The guest accessible volume was found to be 16%. The synthesised phase contained two ethanol molecules and two water molecules in the lattice, and two coordinated water molecules.

Water Vapour Sorption Studies of sql-2-Cu—BF.sub.4

[0252] Water sorption isotherms for sql-2-Cu—BF.sub.4 were collected at 25° C. and 35° C., shown in FIG. 3A and FIG. 3B respectively. The isotherms demonstrated Type F-I isotherm characteristics, pointing to gradual adsorption behaviour from an open to more open phase. Sorption isotherms for both temperatures were repeated and the second sorption isotherm was found to be nearly identical to the first sorption isotherm, indicating that repetitive isotherms on the same sample at different temperatures does not alter the structure of the material. There is a large hysteresis at higher humidity which is not present at lower humidities, demonstrating that the process of switching between a non-porous phase and a porous phase is completely reversible.

Kinetic Studies of sql-2-Cu—BF.sub.4

[0253] Water sorption kinetic data was collected for sql-2-Cu—BF.sub.4 at 25° C. and 35° C., shown in FIG. 4A and FIG. 4B respectively. The adsorption and desorption mechanism profiles are similar at 25° C. and 35° C., with a total uptake of 18 wt % observed. The sample adsorbed water molecules in small increments, with considerably fast adsorption and desorption kinetics.

Reversibility Studies of sql-2-Cu—BF.sub.4

[0254] Reversibility tests on sql-2-Cu—BF.sub.4 were performed at 25° C. to calculate the working capacity in g/g and are shown in FIG. 5.

EXAMPLE 2: sql-3-Cu—BF.SUB.4

[0255] Synthesis of sql-3-Cu—BF.sub.4

[0256] Cu(BF.sub.4).6H.sub.2O (0.237 g, 1 mmol), 1,4-bis(4-pyridyl)biphenyl (0.616 g, 2 mmol) and a few drops of methanol were grinded together for 30 minutes using a ball mill with a frequency of 25 Hz. The resulting powder was washed three times with methanol.

Water Vapour Sorption Studies of sql-3-Cu—BF.sub.4

[0257] Water sorption isotherms for sql-3-Cu—BF.sub.4 were collected at 25° C., 30° C. and 35° C., shown in FIG. 6. The hysteresis gap for this material is narrow, which indicates that water desorption is not restricted. Below 80% relative humidity, water uptake remains unchanged and is independent of temperature, while above 80% relative humidity the water uptake is lower at 35° C. compared to 25° C. and 30° C. The lower water uptakes at higher temperature are expected for a surface adsorption mechanism. All isotherms show type F-IV behaviour, which indicates a sudden switching from a closed phase to an open phase.

[0258] The heat of sorption was calculated from the linear region of the isotherms collected for sql-3-Cu—BF.sub.4 at 25° C., 30° C. and 35° C. using a Virial model. The average heat of sorption for sql-3-Cu—BF.sub.4 was found to be lower than the heat of vaporisation for water at 25° C. This demonstrates the intrinsic heat management offered by square lattice networks, reducing the amount of heat released during adsorption and the impact of cooling during desorption.

Kinetic Studies of sql-3-Cu—BF.sub.4

[0259] Water sorption kinetic data was collected for sql-3-Cu—BF.sub.4 at 25° C., 30° C. and 35° C. over a 0% to 95% relative humidity range, demonstrated in FIGS. 7A, 7B and 7C, respectively. Some water (approximately 10%) is found to remain in the material when desorption steps have completed, illustrated by the mass not returning to its original value at 0% relative humidity. Therefore the structure requires heating or high vacuum in order for the water to be completely removed.

Reversibility Studies of sql-3-Cu—BF.sub.4

[0260] sql-3-Cu—BF.sub.4 was subjected to a 0% to 10% to 0% relative humidity sequence 119 times, and all isotherms were taken on the same sample. Reversible switching isotherms are observed, showing that this material has a robust flexible structure and behaves predictably.

[0261] sql-3-Cu—BF.sub.4 shows a high working capacity in the low partial pressure range as demonstrated in FIG. 8, making sql-3-Cu—BF.sub.4 a potential candidate for water capture in arid conditions.

EXAMPLE 3: sql-1-Co—NO.SUB.3

[0262] Synthesis of sql-1-Co—NO.sub.3

[0263] sql-1-Co-NO.sub.3 was prepared by solvent diffusion. A mixture of 2.5 ml methanol and 2.5 ml α,α,α-trifluorotoluene (TFT) was slowly layered over 4,4′-bipyridine (0.3 mmol, 46.8 mg) dissolved in 5 ml of TFT. A solution of Co(NO.sub.3).sub.2.6H.sub.2O (0.3 mmol, 87.3 mg) in 5 ml methanol was layered over the methanol/TFT layer. The red brick crystals were collected by filtration and washed with TFT three times.

Structure of sql-1-Co—NO.sub.3

[0264] sql-2-Co—NO.sub.3 forms a two-dimensional layered network with Co.sup.2+ ions connected in one and two dimensions by 4,4′-bipyridine to form a square lattice, with NO.sub.3.sup.− also coordinated at the axial positions. The structure can be seen in FIG. 9. This material has an effective pore size of approximately 7.5 Å×7.5 Å.

Water Vapour Sorption Studies of sql-1-Co—NO.sub.3

[0265] Water sorption isotherms were collected on sql-1-Co—NO.sub.3 at 25° C., shown in FIG. 10. The isotherm demonstrates mixed Type F-I and Type F-II behaviour, indicated by a low initial adsorption and substantial uptake at higher relative humidity. The isotherm also shows that the material switches from an open phase to a more open phase.

[0266] The sample retains approximately 4.7% water vapour mass at 0% relative humidity, resulting in an open hysteresis loop. This indicates the sql-1-Co—NO.sub.3 requires heating or high vacuum in order to fully vacate the structure at low partial pressures.

Kinetic Studies of sql-1-Co—NO.sub.3

[0267] Water sorption and desorption kinetics for sql-1-Co—NO.sub.3 were studied at 25° C. and summarised in FIG. 11.

Reversibility Studies of sql-1-Co—NO.sub.3

[0268] There is no discernible difference between the first and tenth cycle isotherms, as illustrated by FIG. 12. In addition, there is no hysteresis between the sorption and desorption isotherms. This indicates that the water sorption mechanism is completely reversible after slight heating at 40° C. between each cycle, and there are no sample history effects related to water sorption. In total, 27 complete adsorption and desorption cycles were collected and the working capacity is also almost constant across the cycles.

EXAMPLE 4: sql-1-Ni—NO.SUB.3

[0269] Synthesis of sql-1-Ni—NO.sub.3

[0270] sql-1-Ni—NO.sub.3 was also prepared using solvent diffusion. A mixture of 2.5 ml methanol and 2.5 ml α,α,α-trifluorotoluene (TFT) was slowly layered over 4,4′-bipyridine (0.3 mmol, 46.8 mg) dissolved in 5 ml of TFT. A solution of Ni(NO.sub.3).sub.2.6H.sub.2O (0.3 mmol, 87.3 mg) in 5 ml methanol was layered over the methanol/TFT layer. The blue crystals were collected by filtration and washed with TFT three times.

Structure of sql-1-Ni—NO.sub.3

[0271] sql-1-Ni—NO.sub.3 forms a two-dimensional layered network with Ni.sup.2+ ions connected in one and two dimensions by 4,4′-bipyridine to form a square lattice, with NO.sub.3.sup.− also coordinated at the axial positions. The structure can be seen in FIG. 13. This material has an effective pore size of approximately 7.5 Å×7.5 Å.

Water Vapour Sorption Studies of sql-1-Ni—NO.sub.3

[0272] Water sorption isotherms were collected on sql-1-Ni—NO.sub.3 at 25° C., shown in FIG. 14. This material has a broad hysteresis in the region between 30% and 70% relative humidity and the loss of water is dramatic during the desorption isotherm, indicating an imminent closed phase structure during dehydration. The isotherm can be characterised by a Type F-III isotherm that shows a gradual uptake from low to high partial pressure.

Kinetic Studies of sql-1-Ni—NO.sub.3

[0273] Water sorption and desorption kinetics for sql-1-Ni—NO.sub.3 were studied at 25° C. and are summarised in FIG. 15.

Reversibility Studies of sql-1-Ni—NO.sub.3

[0274] Reversibility tests on sql-1-Ni—NO.sub.3 were performed to calculate the working capacity and are shown in FIG. 16.

EXAMPLE 5: scl-1-Cu—NO.SUB.3

[0275] Synthesis of sql-1-Cu—NO.sub.3

[0276] sql-1-Cu—NO.sub.3 was again prepared by solvent diffusion, in a similar fashion to sql-1-Ni—NO.sub.3 and sql-1-Co-NO.sub.3. A mixture of 2.5 ml methanol and 2.5 ml α,α,α-trifluorotoluene (TFT) was slowly layered over 4,4′-bipyridine (0.3 mmol, 46.8 mg) dissolved in 5 ml of TFT. A solution of Cu(NO.sub.3).sub.2.6H.sub.2O (0.3 mmol, 87.3 mg) in 5 ml methanol was layered over the methanol/TFT layer. The dark blue crystals were collected by filtration and washed with TFT three times.

Structure of sql-1-Cu—NO.sub.3

[0277] sql-1-Cu—NO.sub.3 forms a two-dimensional layered network with Cu.sup.2+ ions connected in one and two dimensions by 4,4′-bipyridine to form a square lattice, with NO.sub.3.sup.− also coordinated at the axial positions. The structure can be seen in FIG. 17. This material has an effective pore size of approximately 7.5 Å×7.5 Å.

Water Vapour Sorption Studies of sql-1-Cu—NO.sub.3

[0278] Water sorption isotherms were collected on sql-1-Cu—NO.sub.3 at 25° C. and are shown in FIG. 18. The sample progressively adsorbs water until 80% relative humidity, where a significant mass uptake is observed. During desorption, the sample loses a large amount of water, returning to the sorption 0% level at 3% relative humidity. This indicates that the sample returns to the initial form. This material can be characterised by a Type F-III isotherm, showing a gradual uptake from low or intermediate partial pressures and a high uptake at elevated partial pressure. In addition, the hysteresis gap presents shape memory.

Kinetic Studies of sql-1-Cu—NO.sub.3

[0279] Water vapour sorption kinetics for sql-1-Cu—NO.sub.3 were collected at 25° C. and are shown in FIG. 19. The sample mass increases progressively, achieving a 16% change in mass.

Reversibility Studies of sql-1-Cu—NO.sub.3

[0280] Reversibility tests on sql-1-Cu—NO.sub.3 were conducted at 25° C. for ten adsorption-desorption cycles and are summarised in FIG. 20.

EXAMPLE 6: sql-2-Cu-OTf

[0281] Synthesis of sql-2-Cu-OTf

[0282] An ethanol solution (3 ml) containing 1,4-bis(4-pyridyl)benzene (11.6 mg, 0.05 mmol) was slowly layered on top of an aqueous solution (3 ml) copper triflate (9 mg, 0.025 mmol). The light purple crystals were collected by filtration.

Structure of sql-2-Cu-OTf

[0283] sql-2-Cu-OTf forms a two-dimensional layered network with Cu.sup.2+ ions connected in one and two dimensions by 1,4-bis(4-pyridyl)benzene to form a square lattice shown in FIG. 21. There are ethanol and water molecules present in the lattice, as well as one coordinated water molecule. The square lattice frameworks are stacked above each other with an interlayer separation of 4.634 Å. The guest accessible volume was found to be 20%.

Water Vapour Sorption Studies of sql-2-Cu-OTf

[0284] The water vapour sorption isotherm for sql-2-Cu-OTf was collected at 25° C. and is shown in FIG. 22. Below 18% relative humidity, the material almost behaves as a non-porous material, demonstrating little water adsorption. The isotherm shows a dramatic increase in mass between 18% and 30% relative humidity, giving rise to the theory of a closed phase at 0% relative humidity with the ability to reach an open phase at 20% relative humidity. This isotherm closely resembles the Type F-II isotherm with a mild hysteresis gap between 15% and 25% partial pressure.

Kinetic Studies of sql-2-Cu-OTf

[0285] Water sorption and desorption kinetics for sql-2-Cu-OTf were obtained at 25° C. The kinetic data in FIG. 23 demonstrates that all steps reach equilibrium.

Reversibility Studies of sql-2-Cu-OTf

[0286] sql-2-Cu-OTf was subjected to a 0% to 30% to 0% relative humidity sequence 37 times, with isotherms collected on the same sample. Following 37 cycles, sql-2-Cu-OTf is able to uptake 71% of the initial water uptake compared to the first cycle. There is no significant change in the measured water content after the first seven cycles. This demonstrates that sql-2-Cu-OTf is able to reversibly transform its structural framework from a closed phase to an open phase. The results are summarised in FIG. 24.

EXAMPLE 7: sql-A14-Cu—NO.SUB.3

[0287] Synthesis of sql-A14-Cu—NO.sub.3

[0288] A buffer of isopropanol and water (2 ml, v/v=1:1) was layered over an aqueous solution of Cu(NO.sub.3).3H.sub.2O (3 mg, 0.012 mmol). An isopropanol solution of 4,4′-(2,5-dimethyl-1,4-phenylene)dipyridine (7.8 mg, 0.03 mmol) was layered over the buffer layer at room temperature. The resulting blue crystals were isolated with a calculated yield of 55%.

Structure of sql-A14-Cu—NO.sub.3

[0289] sql-2-Cu-OTf forms a two-dimensional layered network with Cu.sup.2+ ions connected in one and two dimensions by 4,4′-(2,5-dimethyl-1,4-phenylene)dipyridine to form a square lattice shown in FIG. 25. Terminal NO.sub.3.sup.− ions are also coordinated at the axial positions. The guest accessible volume was found to be 17%.

Water Vapour Sorption Studies of sql-A14-Cu—NO.sub.3

[0290] Water vapour sorption studies for sql-A14-Cu—NO.sub.3 were performed at 25° C. and 30° C., shown in FIGS. 26A and 26B, respectively. The sample has a narrow hysteresis in the region between 15% and 80% relative humidity. FIG. 26A suggests an adsorption mechanism dominated by Type F-I behaviour, illustrating a gradual mechanism from an open phase to a more open phase.

Kinetic Studies of sql-A14-Cu—NO.sub.3

[0291] Water sorption and desorption kinetics for sql-A14-Cu—NO.sub.3 were obtained at 25° C. and 30° C. The kinetic data is summarised in FIGS. 27A and 27B for 25° C. and 30° C., respectively.

Reversibility Studies of sql-A14-Cu—NO.sub.3

[0292] Twenty-three cycles of adsorption and desorption at 25° C. were performed in total. The adsorption and desorption branch show good agreement, suggest no significant hysteresis. As demonstrated in FIG. 28, the material retains constant working capacity across all of the cycles. The material sql-A14-Cu—NO.sub.3 has a high stability against repeated relative humidity cycles.

EXAMPLE 8: [Cu.SUB.2.(glutarate).SUB.2.(4,4′-bipyridine)]

[0293] Synthesis of [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)]

[0294] Cu(NO.sub.3).3H.sub.2O (242 mg, 1 mmol), glutaric acid (132.1 mg, 1 mmol), and 4,4′-bipyridine (78 mg, 0.5 mmol) were mixed in water (100 ml). NaOH was added dropwise with swirling to the solution to prevent precipitation. The blue solution was placed in an oven preheated to 85° C. Green powder was obtained after 24 to 48 hours. This compound may also be referred to as ROS037. FIGS. 29A and 29B shows the crystallographic structure of this compound.

Water Vapour Sorption Studies of [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)]

[0295] Water vapour sorption studies for [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] were performed at 25° C., shown in FIG. 30. The sample shows a very narrow hysteresis gap, indicating that water desorption is not restricted.

Kinetic Studies of [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)]

[0296] Water sorption and desorption kinetics for [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] were obtained at 25° C., demonstrated in FIG. 31. The kinetics data in FIG. 31 show that all steps reach equilibrium over a range of temperatures. The removal of water from the structure does not require any additional heating or vacuum, as evidenced by the mass returning to its original value at 0% relative humidity.

Reversibility Studies of [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)]

[0297] Nineteen cycles of adsorption and desorption at 25° C. were performed in total. Reversible switching isotherms are observed and no hysteresis gap is detected, indicating water desorption is not restricted. [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] shows a high working adsorption capacity in the low partial pressure range (≤30% P/Po), as demonstrated in FIG. 32.

EXAMPLE 9: Alternative Synthesis of [Cu.SUB.2.(glutarate).SUB.2.(4,4′-bipyridine)]

[0298] In a beaker, Cu(OH).sub.2 (488 mg, 5 mmol) was suspended in 100 mL of water with stirring for 5 minutes. Glutaric acid (1.32 g, 10 mmol) was added and allowed to stir for 5 minutes. The solution became clear and dark blue in colour. 4,4′-bypyridyl (390.5 mg, 2.5 mmol) was added and a green precipitate was formed in 10 minutes. The mixture was filtered and washed with 50 mL of water to obtain the solid product, Yield, 1.332 g, >94%.

[0299] Characterisation of the product confirmed this to be identical to the product obtained in Example 8.

EXAMPLE 10: Lab-Scale Synthesis of [Cu.SUB.2.(glutarate).SUB.2.(4,4′-bipyridine)]

[0300] ROS-037 was synthesized in lab scale by a modified literature protocol as follows: 350 mL of water was taken in a 500 mL conical flask and glutaric acid (24.3 g, 0.184 mol) was added followed by the addition of NaOH (14.7 g, 0.368 mol) and stirred until a clear solution was obtained. Cu(NO.sub.3).sub.2.2.5H.sub.2O (42.7 g, 0.184 mol) was added and allowed to stir for 10 minutes. 4,4′-bypyridyl (14.4 g, 0.092 mol) was added and the mixture was allowed to stir for 1 hour at 70° C. Once the reaction was completed, the solution was filtered to obtain the solid product, and further washed with water to remove any traces of unreacted reactants and air dried. Yield, ˜48 g, >98%.

[0301] Characterisation of the product confirmed this to be identical to the product obtained in Example 8.

EXAMPLE 11: Scale-Up Synthesis of [Cu.SUB.2.(glutarate).SUB.2.(4,4′-bipyridine)]

[0302] ROS-037 can be scaled up to mini-plant scale by water slurry method as follows. 3.5 L of water was added to the 5 L reactor and the stirrer was set to 750 rpm. Glutaric acid (243 g, 1.84 mol) was added and allowed to dissolve for 10 minutes. NaOH (147 g, 3.68 mol) was added and the temperature of the reactor was set to 70° C. (Note: Reaction can be carried out at room temperature also, however more reaction time is required). Once a clear solution is obtained, Cu(NO.sub.3).sub.2.2.5H.sub.2O (427 g, 1.84 mol) was added and allowed to stir for 15 minutes. 4,4′-bypyridyl (144 g, 0.92 mol) was added and the mixture was allowed to stir for 6 hours. Once the reaction was complete, the solution was filtered to obtain the solid product, which was further washed to remove any traces of NaOH and unreacted reactants and air dried. Yield, 481 g, >98%.

[0303] Characterisation of the product confirmed this to be identical to the product obtained in Example 8.

EXAMPLE 12: Synthesis of [Co.SUB.3.(μ.SUB.3.-OH).SUB.2.(btca).SUB.2.]

[0304] A mixture of benzotriazole-5-carboxylic acid (H.sub.2btca; 0.3 mmol, 48 mg), Co(NO.sub.3).sub.2.6H.sub.2O (0.5 mmol, 145 mg), CH.sub.3CN (3 mL), and H.sub.2O (2 mL) was sealed in a 15-mL Teflon-lined stainless reactor, which was heated to 150° C. and held at that temperature for 5 days. After cooling to room temperature, red-pink crystals were separated by decanting and washed with water. Yield: 28 mg, 31%.

[0305] The composition of the material was confirmed by PXRD.

[0306] The vapour sorption isotherm for this material is shown in FIG. 36.

EXAMPLE 13: Synthesis of [Mg.SUB.3.(μ.SUB.3.-OH).SUB.2.(2,4-pyridinedicarboxylate).SUB.2.]

[0307] Pale yellow solution of 2,4-pyridinedicarboxylic acid (167 mg, 1 mmol) and 2 mL of 2M KOH (4 mmol) in 2 mL of H.sub.2O was prepared. Mg(NO.sub.3).sub.2.6H.sub.2O (384 mg, 1.5 mmol) was dissolved in 3 mL of H.sub.2O in a Teflon lined steel autoclave (˜23 mL). The solution of 2,4-pyridinedicarboxylic acid was added to a solution of Mg(NO.sub.3).sub.2 6H.sub.2O under stirring, the formation of white suspension was observed. The reactor was sealed and heated at 210° C. for 15 hours. After cooling over 6 hours, the white crystals were filtered off and washed with water. The solid was then dried in air at ambient conditions. Yield: 130-180 mg, 43-60%.

[0308] The composition of the material was confirmed by PXRD.

[0309] The vapour sorption isotherm for this material is shown in FIG. 37.

EXAMPLE 14: Synthesis of [Co.SUB.3.(μ.SUB.3.OH).SUB.2.(2,4-pyridinedicarboxylate).SUB.2.]

[0310] A solution of 2,4-pyridinedicarboxylic acid (185 mg, 1.0 mmol) and KOH (1.0 M, 3.0 mL) in H.sub.2O (3.0 mL) was added to a stirred aqueous solution (4.0 mL) of CoCl.sub.2.6H.sub.2O (357 mg, 1.5 mmol). The resulting viscous, opaque mixture was heated to 200° C. in a Teflon-lined steel autoclave over 15 h, and then cooled to room temperature over 6 h. The crystalline solid was purified by cycles (3×30 min) of ultrasonic treatment in H.sub.2O (20 mL), followed by decanting of the cloudy supernatant. The solid was then dried in air at ambient conditions. Yield: 210 mg (46%).

[0311] The vapour sorption isotherm for this material is shown in FIG. 38.

EXAMPLE 15: Synthesis of [(Cu.SUB.2.(glutarate).SUB.2.(1,2-di(pyridine-4-yl)-ethene)]

[0312] Glutaric acid (198.0 mg, 1.5 mmol) was dissolved in 10 mL of water in a glass bottle. The solution was heated to 70° C. on a hot plate while stirring. NaOH (120 mg, 3 mmol) was dissolved in 5 mL of water and was slowly added to the hot solution of glutaric acid. Cu(NO.sub.3).sub.2.3H.sub.2O (241.6 mg, 1 mmol) was dissolved in 5 mL of water and added to the hot reaction mixture. A light blue precipitate was formed. After letting the reaction to stir for 10 min, 1,2-di(pyridine-4-yl)-ethene (91.1 mg, 0.5 mmol) was added to the reaction mixture. The precipitate turned to a rich green colour. The reaction mixture was left stirring for 24 h at 80° C. After cooling, the precipitate was filtered, washed with water and oven-dried at 85° C. This material may also be known as AMK-059.

[0313] The composition of the material was confirmed by PXRD.

[0314] The vapour sorption isotherm for this material is shown in FIG. 39.

EXAMPLE 16: Synthesis of [Zr.SUB.12.O.SUB.8.(μ.SUB.3.-OH).SUB.8.(μ.SUB.2.-OH).SUB.6.(benzene-1,4-dicarboxylate).SUB.9.]

[0315] In a Teflon lined steel autoclave (23 mL), ZrOCl.sub.2 8H.sub.2O (97 mg, 0.3 mmol), H.sub.2O (2 mL) and acetic acid (3 mL) were added and formation of clear solution was observed. Terephthalic acid (50 mg, 0.3 mmol) was added to the reaction mixture. The reaction mixture was heated at 150° C. for 1 day. After cooling, the white precipitate was filtered off and washed with H.sub.2O (yield 90 mg), soaked once with 9 mL DMF and soaked three times with H.sub.2O. The solid was then dried in air at ambient conditions.

[0316] The composition of the material was confirmed by PXRD.

[0317] The vapour sorption isotherm for this material is shown in FIG. 40.

EXAMPLE 17: Loading of [(Cu.SUB.2.(glutarate).SUB.2.(4,4′-bipyridine)] (ROS-037) on a Polymer Support

[0318] In a beaker, binder (Acrylic Polymer: HYCAR® 26410 from Lubrizol) was taken and water was added, stirred for 5 minutes. Isopropanol was added and the mixture stirred for a further 5 more and, while stirring continuously, [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] in powder form was added slowly to the solution. The stir bar was removed and blended for 1 minute using a hand blender with short bursts at high speed. Approximately 2 mL of slurry was taken from the beaker by using a dropper and drop casted onto a Teflon petridish before being placed in an oven for 1 hour at 120° C. and transferred to desiccator. The resulting thin film type was tested for its water sorption properties.

[0319] Films were prepared comprising 0, 30, 40, 50, 80, 90 and 100% ROS-037. Adsorption and desorption isotherms were measured at 27° C. and these are shown in FIG. 34. The top curve is for the composition comprising 100% ROS-037 and the bottom one is for the composition comprising 100% binder.

[0320] FIG. 35 shows the kinetics of adsorption.

[0321] These results show that the greater the amount of [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] present in the composite, the faster the kinetics of adsorption and the higher the water uptake.

EXAMPLE 18: Loading of [(Cu.SUB.2.(glutarate).SUB.2.(4,4′-bipyridine)] (ROS-037) on a Paper Support

[0322] [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] powder was added in a standard cellulose paper making process that anyone skilled in the art could perform. Cellulose fiber was first dispersed in water at approximately 3-5% solids. [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] powder was added to the fiber mixture and agitated in order to disperse. The blend was then diluted to very low solids content (1% or less) to provide an attraction between the fibers and the desiccant powder. The evenly dispersed mixture was drained through a screen. The remaining water was removed from the wet sheet of fibers/powder through vacuum, pressing, and drying. Good adsorption and desorption properties were recorded for the resulting material.

[0323] FIG. 41 shows the Powder X-ray diffraction spectrum of the paper composite (top line) in comparison with as synthesized powder (middle line) and calculated powder (bottom line).

[0324] FIGS. 42 and 43 show respectively flat section and cross section SEM images of the paper composite.

[0325] FIG. 44 shows experimental isotherms for water vapour sorption at 27° C. on [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] powder and its paper composite, respectively from the top down. In-situ pre-treatment (intrinsic-DVS) before collecting isotherm at 40° C. for 120 min. Isotherm collected at 27° C. (Intrinsic-DVS). dm/dt<0.01%/min.

EXAMPLE 19: Desalination Testing Using [(Cu.SUB.2.(glutarate).SUB.2.(4,4′-bipyridine)]

[0326] [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] samples were placed in an oven for 12 h at 80° C. Afterwards, the container was sealed and kept under nitrogen flow for 2 h. Adsorbent-solution (solution of 30 mL of saline (NaCl) aqueous solution in a concentration range from 0.0 to 111.1 g/L exposed to 1 g/L, 50 g/L or 500 g/L of adsorbent) were studied at 25° C. Suspensions were stirred using a magnetic stirrer for 8 h. The resulting slurry was filtered with a syringe filter (0.22 μm pore size) and the residual saline solution was collected. NaCl concentration in all aqueous solution (before and after soaking [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] at different concentrations) was analysed by using a conductivity meter (model: JENWAY 4510). Measurements were performed three times and the mean was calculated. The concentration of NaCl (g/L) was determined by correlating the conductivity (mS) and a [NaCl] calibration curve. The results indicate that [Cu.sub.2(glutarate).sub.2(4,4′-bipyridine)] increased NaCl concentration by the expected amount in every experiment.

CHARACTERISATION EXAMPLES

[0327] The porous metal-organic framework materials useful in the present invention have a number of common characteristics and the properties of these materials were tested according to the following methods.

[0328] The properties of the porous metal-organic framework materials of the invention were also compared to silica and mesoporous silica. These materials are the current commercially available materials which can be used in the same applications as the inventive materials.

[0329] Metal-organic materials useful in the present invention preferably satisfy the following criteria:

[0330] 1. Favourable kinetics of adsorption: materials that reach greater than 80% of full loading in less than 10 minutes at 27° C. and 30% RH are preferred.

[0331] 2. Water sorption capacity: materials that offer a water sorption capacity of cm.sup.3 water vapour/cm.sup.3 material under ambient conditions of temperature and humidity (27° C., 1 atm) as determined by vacuum, temperature, humidity or temperature/humidity swing tests are preferred. [0332] 2.1. Vacuum swing tests were conducted using materials that were first fully loaded with water at 97% RH and ambient pressure and subjected to 3 torr of vacuum for 15 minutes. [0333] 2.2. Temperature swing tests were conducted by first loading materials at 27° C. and 30% RH for 14 minutes followed by heating at 60° C. for 15 minutes. [0334] 2.3. Humidity swing tests were conducted by first loading activated sorbents at 30% RH at 27° C. for 14 minutes followed by exposure to a 0% humidity dry gas stream for 40 minutes. [0335] 2.4. Temperature and humidity swing tests that simulate direct air water capture in desert conditions were conducted through 17 adsorption/desorption cycles which involved loading the sorbent at 30% RH at 25° C. for 14 minutes and unloading the sorbent by heating at 49° C. for 20 minutes.

[0336] 3. Thermodynamics of desorption tests were conducted by first loading the porous material at ambient conditions and ˜30-40% RH. Sorbents that offer a desorption temperature <75° C. (determined by the position of the water desorption endotherm minimum when collected using differential scanning calorimetry (DSC)), and a heat of desorption <50 kJ/mol (as measured by combining thermogravimetric analysis (TGA), DSC and intrinsic Dynamic Vapour Sorption isotherm (DVS) measurements) are preferred.

EXAMPLE 20: Sorption Kinetics Testing

[0337] Intrinsic dynamic vapour sorption measurements were carried out on a number of materials at 27° C. and 30% relative humidity. The level of uptake capacity achieved after 10 minutes is shown in Table 1:

TABLE-US-00001 TABLE 1 Uptake Capacity Metal-organic material % Water loading after 10 minutes ROS-037 (Example 8) 99.9 ROS-037 Paper Composite (Example 18) 82.4 Silica Gel 74.6

EXAMPLE 21: Working Capacity

[0338] The working capacity is the difference in water vapour uptake between conditions of adsorption and desorption.

[0339] Adsorption/desorption was induced in various materials under conditions of a vacuum swing, a temperature swing or a humidity swing (see 2.1, 2.2 and 2.3 above for conditions). The results are shown in Tables 2, 3 and 4.

[0340] Following the procedure of section 2.1, a 3 torr vacuum was used and the working capacity was recorded after 15 minutes, as shown below in Table 2:

TABLE-US-00002 TABLE 2 Vacuum Swing Testing Working capacity Metal-organic material (cm.sup.3 water vapour/cm.sup.3 material) sql-2-Cu-BF.sub.4 (Example 1) 306.8 AMK-059 (Example 15) 200.8 ROS-037 (Example 8) 150.8 Mesoporous Silica 39.9 Silica Gel 36.4

[0341] Following the procedure of section 2.2, the working capacity was recorded after 15 minutes, as shown below in Table 3:

TABLE-US-00003 TABLE 3 Temperature Swing Testing Working capacity Metal-organic material (cm.sup.3 water vapour/cm.sup.3 material) Co-CUK-1 (Example 14) 204.0 ROS-037 (Example 8) 174.0 Mg-CUK-1 (Example 13) 135.1 hcp-UiO-66 (Example 16) 123.6 [Co.sub.3(μ.sub.3-OH).sub.2(btca).sub.2] (example 12) 133.9 sql-2-Cu-BF.sub.4 (example 1) 139.9 Silica Gel 27.8 Mesoporous Silica 2.5

[0342] Following the procedure of section 2.3, the working capacity was recorded after 40 minutes, as shown below in Table 4:

TABLE-US-00004 TABLE 4 Humidity Swing Testing Working capacity Metal-organic material (cm.sup.3 water vapour/cm.sup.3 material) Co-CUK-1 (Example 14) 202.9 ROS-037 (Example 8) 185.3 Mg-CUK-1 (Example 13) 131.5 hcp-UiO-66 (Example 16) 102.4 [Co.sub.3(μ.sub.3-OH).sub.2(btca).sub.2] (example 12) 121.1 sql-2-Cu-BF.sub.4 (example 1) 139.2 Silica Gel 21.0 Mesoporous Silica 3.6

EXAMPLE 22: Thermodynamics of Desorption

[0343] As mentioned above, heat of desorption was calculated by combining measurements taken by thermogravimetric analysis, differential scanning calorimetry and intrinsic dynamic vapour sorption isotherm measurements. The results are shown in Table 5 below:

TABLE-US-00005 TABLE 5 Heat of Desorption Metal-organic material Heat of desorption (kJ/mol) ROS-037 43.3 Mg-CUK-1 51.7 Silica Gel 59.4 Syloid AL-1 76.1 Zeolite 13X 203.8