A. Field of the Invention

The present invention relates generally to a new method and practical method for metal organic framework synthesis and, more particularly to a system and method for making metal organic framework materials crystallized by polyoxometallate templates, transition metal ions or transition metal clusters, linked by organic ligands and more particularly a fast and convenient method for synthesis of metal organic frameworks even in a time of a few minutes at a temperature below 30°C using polyoxometallate molecules as molecular templates, transition metal ions or transition metal clusters and organic ligands .

Several documents are cited throughout the text of this specification. Each of the documents herein (including any manufacturer's specifications, instructions etc.) are herby incorporated by reference; however, there is no admission that any document cited is indeed prior art of the present invention.

B. Description of the Related Art

Metal organic frameworks (MOFs) are porous materials composed of transition metal ions or clusters, linked by organic ligands.

They are particular suitable. Metal organic frameworks (MOFs) materials are for instance used to fabricate porous materials which are currently used for the absorption of liquids for binding=liquids in=or=tθ'them-in-order=to=ensure4hat=these=liquids-do-not=s pread-or-come=into- contact with other liquids or solids or to make the abovementioned liquids capable of being handled. The porous metal-organic framework are for instance used to store gases, such as hydrogen. The current hydrothermal synthesis process of fabrication of such MOFs has particular disadvantages. Porosity is enforced by the rigidity of the linkers and the specific coordination geometry around the transition metal ions.

In present invention we report the first example of the synthesis of a MOF using a template. Moreover the present invention demonstrates that template reduces the conventional hydrothermal synthesis process of Cu ₃ (BTC) ₂ at temperatures from 100-180 °C to an instantaneous room temperature self-assembly.

A benefit not to be dependent on hydrothermal synthesis is that the MOF' s can be directly formed on devices and substrates (for instance into a coating) that otherwise would not resist the hydrothermal process or a temperature above room temperature or in the of 100-180 °C range . The formation of MOF' s on thermosensitive or low melt point materials is a particular embodiment of present invention.

Beside this significant practical benefit, the molecular mechanism of the template action could be determined.

SUMMARY OF THE INVENTION

In accordance with the purpose of the invention, as embodied and broadly described herein, the invention is broadly drawn to a method for fabricating a metal organic frameworks material, comprising the steps: combing solutions of polyoxometallate molecules as molecular templates, and of transition metal ions or transition metal clusters; and mixing it at room temperature with an organic ligand solution to form calcium said metal organic frameworks material. Such fabrication is very practical since the metal organic frameworks material form at room temperature and in times of minutes.

In ^~ a ^~ parπcuiardnDoαiment or present invention ine metnoα oi iaoncanng a meiai organic frameworks material, comprises combining polyoxometallate molecules as molecular templates, transition metal ions or transition metal clusters and organic ligands in a watery reaction mixture at room temperature, whereby the reaction is at room temperature and during a time less than 24 h and depending on the condition even in less than 1 hour. Formation of the metal organic frameworks actually occurred in a few minutes. Yet another embodiment of present invention is a method for synthesis of metal organic frameworks in a time of minutes at a room temperature using polyoxometallate molecules as molecular templates, transition metal ions or transition metal clusters and organic ligands at a temperature above 7°C and below 30°C

The invention also concerns a metal organic framework material crystallized from mixed polyoxometallate templates, transition metal ions or transition metal clusters and from linking by organic ligands.

These metal organic framework materials are very useful. They can be used to synthesize powders, films and coatings for application in molecular separation, purification, protective clothing and catalysis .

Some embodiments of the invention are set forth in claim format directly below:

1. A method for fabricating a metal organic frameworks material, comprising the steps: combing solutions of polyoxometallate molecules as molecular templates, and of transition metal ions or transition metal clusters; in a recipient or reactor and mixing it less than 35 °C with an organic ligand solution until formation or self assembling of said metal organic frameworks material.

2. The method for fabricating the metal organic frameworks material of embodiment 1, wherein the temperature is room temperature.

3. The method for fabricating the metal organic frameworks material of embodiment 1, wherein the temperature is less than 30 ⁰ C.

4. The method for fabricating the metal organic frameworks material of embodiment 1, wherein the temperature is between 5 and 30°C.

5. The method for fabricating the metal organic frameworks material of embodiment 1, wherein the recipient or reactor is not pressurized. 6. The method for fabricating the metal organic frameworks material of embodiment 1, wherein the recipient or reactor is not an hydrothermal recipient or reactor or where the process is under non hydrothermal conditions.

7. The method for fabricating the metal organic frameworks material of embodiment 1, wherein the recipient or reactor is open or a contact with the atmosphere via an opening. 8. The method for fabricating the metal organic frameworks material of embodiment 1, wherein the formation or self assembling of said metal organic frameworks material is under normal atmospheric pressure.

9. The method for fabricating the metal organic frameworks material of embodiment 1, wherein the solution is in a watery medium

10. The method for fabricating the metal organic frameworks material of embodiment 1, wherein the solution is water

1 1. The method for fabricating the metal organic frameworks material of embodiment 1 , wherein the solution is water and alcohol. 12. The method for fabricating the metal organic frameworks material of embodiment 1, wherein the solution is water and ethanol

13. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 to 12, wherein the formation or self assembling of said metal organic frameworks material is a spontaneous and immediate formation or self assembling. 14. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the mixing is for less than 5 minutes.

15. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the reacting of self assembling time to form the metal organic frameworks material in less than 5 minutes 16. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the mixing is for less than 20 min. .

17. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the reacting of self assembling time to form the metal organic frameworks material in less than 20 minutes. 18. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the mixing is for less than 1 hour.

19. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the reacting of self assembling time to form the metal organic frameworks material in less than 1 hour. 20. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the mixing is for less than 5 hour.

21. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the reacting of self assembling time to form the metal organic frameworks material in less than 5 hour. 22. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the mixing is for less than 12 hour.

23. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the reacting of self assembling time to form the metal organic frameworks material in less than 12 hour.

24. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the mixing is for less than 24 hour.

25. The method for fabricating the metal organic frameworks material of any of the previous embodiments 1 - 13, wherein the reacting of self assembling time to form the metal organic frameworks material in less than 24 hour.

26. The method for fabricating the metal organic frameworks material of any of the previous embodiments, wherein the recipient further comprises a carrier material or a substrate whereon or wherein the polyoxometallate molecules as molecular templates, the transition metal ions or transition metal clusters the organic ligand are forming or self assembling the metal organic frameworks material.

27. The method for fabricating the metal organic frameworks material of embodiment 26, whereby the carrier material or substrate is a film

28. The method for fabricating the metal organic frameworks material of embodiment 26, whereby the carrier material or substrate is a protective clothing The method for fabricating the metal organic frameworks material of embodiment 26, whereby the carrier material or substrate is a fibre, textile or a surfaces

29. The method for fabricating the metal organic frameworks material of any of the previous embodiments, to synthesize of powders, films or coatings for application in molecular separation, purification, protective clothing and catalysis 30. The powders, films or coatings obtainable by embodiment 29, for use in molecular separation, purification, protective clothing and catalysis.

31. A method of fabricating a metal organic frameworks material, comprising: combining oolvoxometallate molecules as molecular templates, transition metal ions or transition metal clusters and organic ligands in a watery reaction mixture at room temperature, whereby the reaction is at room temperature and during a time less than 24 h .

32. The method for fabricating the metal organic frameworks material of embodiment 31, wherein the mixing until self assembling or formation of the metal organic frameworks material is for less than 12 h . 33. The method for fabricating the metal organic frameworks material of embodiment 31, wherein the mixing until self assembling or formation of the metal organic frameworks material is for less than 6 h .

34. The method for fabricating the metal organic frameworks material of embodiment 31, wherein the mixing until self assembling or formation of the metal organic frameworks material is for less than 1 h .

35. The method for fabricating the metal organic frameworks material of embodiment 31, wherein the mixing until self assembling or formation of the metal organic frameworks material is for less than 15 minutes. 36. A method for synthesis of metal organic frameworks in a time of minutes at a room temperature using polyoxometallate molecules as molecular templates, transition metal ions or transition metal clusters and organic ligands at a temperature above 7°C and below 30°C 37. A metal organic framework material crystallized from mixed polyoxometallate templates, transition metal ions or transition metal clusters and from linking by organic ligands. 38. Synthesis of powders, films and coatings for application in molecular separation, purification, protective clothing and catalysis using the metal organic framework materials of previous embodiments.

39. A carrier comprising the metal organic framework material obtained by any of the previous embodiments 1 - 38. 40. The carrier of embodiment 39, whereby the carrier is a film.

41. The carrier of embodiment 39, whereby the carrier is a protective clothing.

42. The carrier of embodiment 39, whereby the carrier is a coatings on fibres, textiles or surfaces.

43. A carrier coated by a metal organic framework material for instance the metal organic framework obtained by any of the previous embodiments 1 - 38, whereby the carrier is a material having a low melting point.

44. A carrier coated by a metal organic framework material for instance the metal organic framework obtained by any of the previous embodiments 1 - 38, whereby the carrier is__a_ material having a melting point at normal atmospheric pressure under a temperature value in the range 100 - 180°C.

45. A carrier coated by a metal organic framework material for instance the metal organic framework obtained by any of the previous embodiments 1 - 38, whereby the carrier is a material having at normal atmospheric pressure a melting point under 100 °C 46. A carrier coated a metal organic framework material for instance the metal organic framework obtained by any of the previous embodiments 1 - 38, whereby the carrier is thermoplastic polyesters.

47. A carrier coated by a metal organic framework material for instance the metal organic framework obtained by any of the previous embodiments 1 - 38, whereby the carrier is a thermoplastic polyester of the group consisting of PET, PBT, PCTG, PCT, PETG, and PTT.

48. A carrier coated a metal organic framework material for instance the metal organic framework obtained by any of the previous embodiments 1 - 38, whereby the carrier is a thermoplastic vinyl polymer of the group consisting of PMMA, SAN, ABS, EPDM, MBS and Poly butyl acrylate.

49. The use of the metal organic framework material or carrier comprising the metal organic framework material obtained by any of the previous embodiments 1 - 38, in a process of the group consisting of catalysis, molecular separation, purification, gas absorption.

50. Any of the previous embodiments, whereby the polyoxometallate is heteropoly acid (HPA)

51. Any of the previous embodiments, whereby the polyoxometallate is H3PMol2O40, H3PW12O40 or H4SiW12O40.

52. Any of the previous embodiments, whereby the polyoxometallate is silicotungstic acid.

53. Any of the previous embodiments, whereby the transition metal is under the form of Cu(NO3)2.

54. Any of the previous embodiments, whereby the transition metal is under the form of transition metal nitrate.

55. Any of the previous embodiments, whereby the organic ligand benzene tri carboxylic acid. 56. Any of the previous embodiments, whereby the solvent is a watery solution.

57. Any of the previous embodiments, whereby the solvent is a water/alcohol solution.

58. Any of the previous embodiments, whereby the solvent a water/ethanol solution.

59. Any of the previous embodiments, whereby the pH of the solution is maintained at ~ 1.2.

60. Any of the previous embodiments, whereby the pH of the solution is maintained between 1 and 3.

61. Any of the previous embodiments, whereby the pH of the solution is maintained between l and 1.5. Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly set out in the claims.

Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Detailed Description

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The following detailed description of the invention refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims and equivalents thereof.

Room temperature as used herein is a common term to denote a certain temperature within enclosed space at which humans are accustomed. Room temperature is thus often indicated by general human comfort, with the common range of 7°C (44°F) to 32 ⁰ C (90 ⁰ F).

"Clusters" as used herein refers to more than one, and typically three or more transition metal atoms coupled to one another by metal-type bonds or ionic bonds. Clusters are intermediate in size between single atoms and colloidal materials. The metal components in the framework according to the present invention is preferably selected from the groups Scandium, Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Yttrium, Zirconium, Niobium, Molybdenum, Technetium, Ruthenium, Rhodium, Palladium, Silver, Cadmium, Lanthanum, Hafnium, Tantalum, Tungsten, Rhenium, Osmium, Indium, Platinum, Gold, Mercury, Actinium, Rutherfordium, Dubnium, Seaborgium, Bohrium, Hassium, Meitnerium, Darmstadtium, Roentgenium and Ununbium.

Suitable transition metals can for present invention be under the form of a transition metal nitrate, i.e. a nitrate of metals selected from Groups 3-12 inclusive of the Periodic Table of the Elements. This can include nitrates of La, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu and Zn, more preferably nitrates of Cr, Mn, Fe, Ru, Co, Rh, Lr, Ni, Pd, Pt, Cu and Zn.. By the term "transition metal nitrate" we include transition metal nitrate compounds of formula M(NO3)X whereby x is the valency of the transition metal M.

We prepared a solution of Cu(NO ₃ ) ₂ to which we added successively an aqueous solution of HPA and 1, 3, 5 - Benzene-tri-carboxylic acid (BTC), under not hydrothermal conditions. We observed instantaneous and stoichiometric formation of Cu ₃ (BTC) ₂ -type metal organic framework with intact HPA molecules positioned in the MOF pores under this not hydrothermal conditions f(or instance at room temperature and an normal atmospheric pressure). In absence of HPA the synthesis failed to yield a crystalline material. The synthesis also failed when BTC was added prior to HPA. The importance of the addition order was an indication that HPA takes the role of arranging the Cu ²⁺ ions in the way needed to build the MOF framework. A direct interaction between the Cu and Keggin ions was revealed using two different experimental approaches - ³¹ P & ¹⁷ O nuclear magnetic resonance (NMR) and dynamic light scattering (DLS) were used.

Direct ⁼ evidence ⁼ of^me^template ⁼ action^during=synthesis=is= ⁱ obtained=-from ⁱ⁼ ^P=^NMR spectroscopy performed on the reaction mixture containing Cu ²⁺ and H ₃ PMo I ₂ O ₄ O- Figure 2 shows that a clear shift of 0.7 ppm is observed in the ³¹ P resonance of the Keggin HPA upon addition of Cu ²⁺ . Such a prominent impact on the local environment of the central P atom in the Keggin ion can only be result of a strong interaction of the HPA with Cu ²⁺ ions. Upon adding BTC to this solution a further slight shift of ³¹ P NMR resonance indicated a slightly reduced Cu ²⁺ -Keggin interaction, presumably due to the coordination of BTC linker to Cu ²⁺ . Unequivocal confirmation of BTC binding was obtained from ¹ H NMR spectra. A large broadening and a downfield shift of BTC proton resonance from 8.80 to 9.26 ppm upon its addition to Cu ² VHPA system, strongly indicate the coordination of BTC to Cu ²⁺ ions.

Extra proof for the strong interaction of Cu ²⁺ with HPA oxygen atoms before BTC addition was obtained from ¹⁷ O NMR spectra. The Cu concentration was selected to be sufficient to bind to 80% of the present terminal oxygen atoms of the Keggin ions. Under normal conditions a comparable solution of Cu(NO)3)2 yields no signal of water oxygen due to fast exchange of the water molecules in the vicinity of the paramagnetic ion which is causing rapid relaxation and extensive signal broadening. However, in the presence of HPA a strong water signal easily is observed. This is a clear hint that the majority, if not all, of the Cu ions is removed from water interaction and fast exchange. Furthermore, the spectrum shows a large shifting and splitting of all ¹⁷ O resonances assigned to HPA. Due to the symmetrical structure of free, deprotonated H ₃ PMOi ₂ O ₄₀ , its ¹⁷ O NMR spectrum consists of only three O signals at 769, 427 and 409 ppm ⁴ . Especially the resonance of the terminal oxygen is significantly shifted by about 70 ppm. This can be taken as evidence these oxygen atoms are affected the strongest by the presence of Cu ions which supports the here developed model of template action, where Cu ions are binding to the terminal oxygen atoms of the HPA. Upon addition of Cu ²⁺ the resonances not only shift but also split: The symmetrical HPA structure has been perturbed due to strong interaction with Cu ²⁺ . The break in symmetry can only occur if equivalent oxygen atoms have varying environments on the timescale of the NMR experiment. This shows that the Cu ions reside long times in the vicinity of one terminal oxygen atom. As there are insufficient numbers of Cu ions present in the solution the symmetry of the Keggin ions no longer is retained.

If indeed the Cu ions firmly associate with the Keggin ions the assembly should show different dvnamic behavior compared to free Keεein ions. To confirm this, dynamic lifiht scattering (DLS) experiments were performed for both the HPA and Cu-HPA solutions. A strongly increased count rate was consistent with the overall increase in particle size when Cu was added to the HPA solution. Diffusion constants derived from the correlation function indicated strongly retarded dynamics after addition of Cu2+ which in turn indicates the diffusive motion of the Keggin ions indeed is strongly slowed by interaction. As already indicated by IH NMR adding BTC as organic linker to the solution clearly points at interaction of the molecules with Cu-ions and/or strong increase of particle size as was derived from the strong line broadening of the proton resonances. As a matter of fact after the addition of BTC to the solution and within the short time necessary to place the sample into the laser (1-2 min) 500nm sized particles are formed, which were identified by PXRD of the crystal suspension as crystalline CuBTC with outstanding crystallinity as was derived from the small line width of the reflections (Figure 3)

Immediately after formation the crystals show cubic habitus (figure 4). When the solution is stirred for two days the crystals have assumed octahedral shape which indicates the (111) face to be the face lowest in energy. The change of the crystal shape from cubes to octahedra is further evidence the initial formation of the material is a spontaneous, structure directed self- organization and only at later stages the crystals assume lowest energy configuration. Consistent results from NMR and DLS experiments helped us to conclude that HPA acts as a structure directing agent by defining the position of Cu atoms before the ligand is added to solution. The organic linkers then consolidate the Cu-positions by coordination and in a last step the building units assemble rapidly into the final crystalline material (Figure 5)

Up to now the same scenario was encountered for three different types of HPAs: H ^" 3PMoi ₂ 0 ₄ o, H ₃ PW ₁₂ O ₄₀ and H ₄ SiWi ₂ O ₄₀ . Silicotungstic acid anions carry a charge of 4- compared to the 3- of the phosphoric Keggin species. The variation of charge appears to have no effect on the structure directing power during MOF formation. All structures were confirmed by Rietveld refinement of powder X-ray diffraction data based on data describing hydrothermal synthesis [Kozhevnikov, I. V. Chem. Rev., 98, 171-198 (1998)]. As can be seen in figure 1 and 5, the CuBTC framework consists of two types of large cavities which differ in orientation of the linker molecules and Cu-pairs. Keggin ions only reside in those cavities of the structure where the BTC molecules are in plane with the cavity wall. This is a direct consequence of presented model where first copper is prearranged, then linked during formation of a cavity and finally during structure assembly re-organized into the paddlewheels made up from 2 Cu ions and 4 BTC molecules (figure 5). In the final structures water is found in the other type of large cavity in interaction distance with the copper ions which point directly into these cages.

The present invention thus clearly demonstrates the structure directing behavior of HPAs for the synthesis of particular MOF materials. Even though the use of templates for synthesis of MOFs has been conceived, the direct observation of structure directing behavior was not observed before. Our examples clearly shown that it is possible to analyze the dynamics of molecular interaction of the HPAs and Cu ions with high precision and tune the conditions for successful synthesis of HPA incorporated MOFs at room temperature.

Our room temperature synthesized MOFs resemble the materials obtained under hydrothermal conditions (Figure 1 ) but show superior crystallinity.

The successful incorporation of Mo and W-based HPAs in MOF pores suggests possible extension of incorporating different types of heteropoly acids and polyoxometallates in various other MOF materials. Potential applications such as for the synthesis of films, coatings on fibles, textiles and surfaces and application in catalysis, molecular separation, purification, gas absorption and protective clothing will largely benefit from this discovery of a synthesis under ambient conditions.

Methods

Synthesis of MOF-HPA at room temperature

A typical synthesis procedure was followed: 1.215 g of Cu(NO ₃ ) ₂ (Fluka) was dissolved with

25ml of water. To this, a solution of 0.8 g of HPA (Fluka) dissolved in 25 ml of water was added and stirred for 5 min. The pH of the solution was maintained at ~ 1.2. A solution of 0.5825 g of 1, 3, 5 Benzene tri carboxylic acid (Acros organics) in 25 ml of ethanol (VWR) was added and stirred for 24 h at room temperature. The product formed was filtered with repeated washing with water and dried at 40 °C. The reactant weights, reagent volume, pH of the solution, period of stirring and the sequence of addition of individual solution was optimized by changing each parameter (for example, the volume of water and ethanol), and characterizing the reaction products formed. Stirring for a longer period of time (1 to 6 days) did not show any changes in the reaction products formed.

Synthesis of MOF-HPA by hydrothermal route The hydrothermal synthesis of MOF-HPA was based on the standard procedure [Luc Alaerts et al. Chem. Eur. J., 12, 7353-7363 (2006)]. 1.215 g of Cu(NO3)2 (Aldrich) and 0.8 g of HPA(Aldrich) was dissolved in ~ 25 ml water and stirred. To this, 0.5825 g of 1, 3, 5 Benzene-tri-carboxylic acid dissolved in 25 ml of ethanol (Acros organics) was added and allowed to stir for 30 min at room temperature. The reaction mixture was then filled in teflon- lined autoclaves and heated to 110 °C for 15 h with the rate of 1 °C/min and then allowed to cool for a day. The reaction product was then filtered with repeated washing with water and dried at 40 °C.

³¹ P and ¹⁷ O NMR

³¹ P NMR spectra were measured at 162 MHz on a Bruker Avance 400 spectrometer. External 85% phosphoric acid reference was used. The amount of Cu(NO ₃ ) ₂ , HPA and BTC taken were similar to that used in the synthesis. The solutions were prepared in D ₂ O and pH of the solution mixture was maintained at 1.2. ¹⁷ O NMR spectra were recorded at 81 MHz on a Bruker Avance 600 spectrometer. 3 ml solution of 0.5 M HPA and 0.4 M Cu(NO ₃ ) ₂ at a pH of 1.6 was prepared in D ₂ O, and D ₂ O was used as the reference.

DLS

0.005 M solution of H ₃ PMoi ₂ 0 ₄ o and 0.13 M Cu(NO ₃ ) ₂ solution was prepared in filtered Millipore water using 20 nm Whatman antop syringe filters. The samples were measured in glass tubes. After inserting the sample in the instrument, 5 min were allowed for temperature stabilization. The laser wavelength of 659 nm was used. Measurements were performed in three different angles 30, 90 and 150°. A time delay of 60 s was used between the measurements at each angle. Since the HPA gave very weak signals due to very small particles, the measurement was performed for 24 h duration for both the HPA and Cu-HPA solutions.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Drawing Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

Figure 1 displays a structure that includes HPA's were H8-xXM12O40, with X being Si4+ or P5+, x representing the positive charge on these atoms, and M being Mo6+ or W6+. In those structures there exists a striking relationship between the geometries of the Keggin type heteropoly acid and one of the two cavities of Cu3(BTC)2 framework. The oxygen atoms of the HPA molecule point directly towards 12 positions of the nodes of the cuboctahedral Cu3(BTC)2 cavity

Figure 2: is a view demonstrating the ³¹ P NMR of Cu-HPA interaction in D ₂ O: (A) pure H ₃ PMOi ₂ O ₄₀ (B) mixture of Cu-H ₃ PMo ₁₂ O ₄ O and (C) mixture of Cu-H ₃ PMOi ₂ O ₄₀ with BTC. A peak at O ppm belongs to external reference (85% phosphoric acid).

Figure 3. demonstrates the replace with decay curves.

Figure 4. is a picture of crystalline CuBTC immediately after formation. The crystals show cubic habitus.

Figure 5 demonstrates the structure directing effect of HPA on Cu2+ during formation of MOF framework