WATER REPELLENT METAL-ORGANIC FRAMEWORKS, PROCESS FOR MAKING AND USES REGARDING SAME

• US 20100075123A1
• Filed: 04/08/2009
• Published: 03/25/2010
• Est. Priority Date: 04/08/2008
• Status: Active Grant

• Current Assignee: Board of Trustees of The University of Illinois
• Original Assignee: University of Illinois
• Inventors: NI, Zheng, MASEL, Richard I., CHEN, Qingmei
• Granted Patent: US 8,269,029 B2
• Time in Patent Office: Days
• US Class Current: 428/219
• CPC Class Codes: C07C 51/412 by conversion of the acids, their salts, esters or anhydrides with the same carboxylic acid part
• CPC Class Codes: C07C 63/15 all carboxyl groups bound to carbon atoms of the six-membered aromatic ring
• CPC Class Codes: C07C 63/28 Salts thereof
• CPC Class Codes: C07C 65/21 containing ether groups, groups, groups, or groups

Abstract

Microwave assisted synthesis may be used to produce water-repellent metallic organic frameworks (MOFs) molecules. The water-repellent MOFs contain non-polar functional groups, such as a trifluoromethoxy group, which has a strong water repellent effect. The water-repellent MOF, when exposed to water vapor for one week does not result in a significant X-ray power pattern change. The water-repellent MOFs may be suitable as an adsorbent in many industrial applications, such as gas chromatography.

Claims

1. A metal organic framework (MOF), comprising:

a plurality of metals and/or metal oxides and a plurality of ligands arranged to form a crystalline structure having a surface area of at least about 100 m²/gm, wherein said plurality of ligands have a structure of formula I;

2. The MOF of claim 1, wherein the major peaks in the X-ray powder diffraction (XRPD) spectrum of said MOF do not significantly shift when the MOF is exposed to water vapor for greater than about 1 hour, wherein the XPDP of the MOF before and after exposure to water vapor is substantially unchanged.

3. The MOF of claim 1, wherein said metal is one or more metals selected from the group consisting of magnesium, cadmium, beryllium, copper, terbium, gadolinium, iron, nickel, cobalt, silver and zinc.

4. The MOF of claim 1, wherein said metal oxide is one or more metal oxides selected from the group consisting of magnesium oxide, cadmium oxide, beryllium oxide, copper oxide, terbium oxide, gadolinium oxide, iron oxide, nickel oxide, cobalt oxide, silver oxide and zinc oxide.

5. The MOF of claim 1, wherein said metal is zinc and wherein R₁ is a methyl, ethyl, methoxy, trifluoromethyl, 1,1,1-trifluoroethyl, or trifluoromethoxy group and at least one of R₂, R₃, and R₄ is hydrogen.

6. The MOF of claim 1, wherein said metal is zinc and wherein at least one of R₁ and R₃ is a methyl, ethyl, methoxy, trifluoromethyl, 1,1,1-trifluoroethyl, or trifluoromethoxy group and at least one of R₂ and R₄ is hydrogen.

7. The MOF of claim 1, wherein said metal is copper and wherein at least one of R₁ and R₃ is a ethyl or methyl group and at least one of R₂ and R₄ is hydrogen.

8. The MOF of claim 1, wherein said metal is copper and wherein at least one of R₁ and R₃ is a methoxy group and at least one of R₂ and R₄ is hydrogen.

9. The MOF of claim 1, wherein said metal is cadmium and wherein at least one of R₁ and R₃ is a methoxy group and at least one of R₂ and R₄ is hydrogen.

10. The MOF of claim 1, wherein said crystalline structure is a non-linear structure.

11. The MOF of claim 10, wherein the non-linear structure is selected from the group consisting of cubic, spherical, oval, elliptical, fan-shaped, plate-shaped, rectangular, hexagonal, needle, rod, and irregularly shaped.

12. The MOF of claim 1, wherein said MOF is non-isoreticular.

13. The MOF of claim 1, wherein at least one of R₁ and R₂, and at least one of R₃ and R₄ are non-polar functional groups.

14. The MOF of claim 1, wherein said crystalline structure has a plurality of micropores.

15. The MOF of claim 14, wherein the pores have a size in a range of about 1 nm to about 3 nm.

16. The MOF of claim 1, wherein the MOF contains a plurality of macropores.

17. The MOF of claim 1, wherein the MOF includes a plurality of particles having a diameter less than about 40 nm.

18. The MOF of claim 1, wherein the MOF is a sorbent of analyte in a collection system.

19. The MOF of claim 18, wherein the collection system comprises one of a preconcentrator, micropreconcentrator, personal respirator, and dosimeter.

20. The MOF of claim 19, wherein one of the preconcentrator or micropreconcentrator is a purge and trap system, microelectromechanical (MEMS) valve system, array of microstructures, dosimeter, disc, pellet, or swab.

21. A process for synthesizing a water-repellent metallic organic framework (MOF), having a crystalline structure having a surface area of greater than about 100 m²/gm, said process comprising the steps of:

removing impurities from an organic ligand to provide a pre-treated organic ligand;

dissolving a metal and/or metal oxide and the pre-treated organic ligand in a solvent to provide a solution; and

subjecting the solution to microwaves for a time sufficient to form crystals of the water-repellent MOF.

22. The process of claim 21, further comprising the step of removing metal impurities from the water-repellent MOF.

23. The process of claim 22, wherein the metal impurities are removed by extracting them into an extractor solvent using a soxhlet extraction apparatus.

24. The process of claim 23, wherein the soxhlet extraction solvent is CH₂Cl₂.

25. The process of claim 21, wherein the organic ligand is a compound selected from the group consisting of terephthalic acid, naphthalene dicarboxylic acid, biphenyl-dicarboxylic acid, benzene tricarboxylic, di(carboxyphenyl)benzene, imidazole, benzimidazole, alkane dicarboxylic acid, alkene dicarboxylic acid, and alkyne dicarboxylic acid.

26. The process of claim 21, wherein the metal oxide is one or more metal oxides selected from the group consisting of magnesium oxide, cadmium oxide, beryllium oxide, copper oxide, terbium oxide, gadolinium oxide, iron oxide, nickel oxide, cobalt oxide, silver oxide and zinc oxide.

27. The process of claim 21, wherein the metal is one or more metals selected from the group consisting of magnesium, cadmium, beryllium, copper, terbium, gadolinium, iron, nickel, cobalt, silver and zinc.

28. The process of claim 21, wherein the impurities are removed by a method selected from the group consisting of contacting the ligand with a chelating resin, soxhlet extraction, liquid-liquid extraction, evaporation and precipitation, and removing metal by washing.

29. A process for synthesizing a water-repellent metallic organic framework (MOF), having a crystalline structure and a surface area of greater than about 100 m²/gm, said process comprising the steps of:

dissolving zinc nitrate hexahydrate and 2-trifluoromethoxy terephthalic acid in a solvent to provide a solution; and

subjecting the solution to microwaves for a time sufficient to form crystals of the water-repellent MOF.

30. The process of claim 29, wherein the sufficient time is about 80 seconds.

31. The process of claim 29, wherein the crystalline structure is cubic and the crystals in said heating step have a size in a range of about 4 μ

m to about 7 μ

m.

32. A process for synthesizing a water-repellent metallic organic framework (MOF), having a crystalline structure and a surface area of greater than about 100 m²/gm, said process comprising the steps of:

dissolving zinc nitrate hexahydrate and 2,5-dimethylterephthalic acid in a solvent to provide a solution; and

subjecting the solution to microwaves for a time sufficient to form crystals of the water-repellent MOF.

33. The process of claim 32, wherein the sufficient time is about 30 seconds.

34. The process of claim 32, wherein the crystalline structure is cubic and the crystals in said heating step have a size in a range of about 1 μ

m to about 3 μ

m.

35. A process for synthesizing a water-repellent metallic organic framework (MOF), having a crystalline structure having a surface area of greater than about 100 m²/gm, said process comprising the steps of:

dissolving cupric nitrate and 2,5-dimethylterephthalic acid in a solvent to provide a solution; and

subjecting the solution to microwaves for a time sufficient to form crystals of the water-repellent MOF.

36. The process of claim 35, wherein the sufficient time is about 30 seconds.

37. The process of claim 35, wherein the crystalline structure is irregularly shaped.

38. A process for synthesizing a water-repellent metallic organic framework (MOF), having a crystalline structure and a surface area of greater than about 100 m²/gm, said process comprising the steps of:

dissolving cupric nitrate and 2,5-dimethoxyterephthalic acid in a solvent to provide a solution;

subjecting the solution to microwaves for a time sufficient to form crystals of the water-repellent MOF.

39. The process of claim 38, wherein the sufficient time is about 30 seconds.

40. The process of claim 38, wherein the crystalline structure is fan-shaped.

41. A process for synthesizing a water-repellent metallic organic framework (MOF), having a crystalline structure and a surface area of greater than about 100 m²/gm, said process comprising the steps of:

dissolving cadmium nitrate tetrahydrate and 2,5-dimethoxyterephthalic acid in a solvent to provide a solution; and

subjecting the solution to microwaves for a time sufficient to form crystals of the water-repellent MOF.

42. The process of claim 41, wherein the sufficient time is about 30 seconds.

43. The process of claim 41, wherein the crystalline structure is plate-shaped.