Large pore metal organic frameworks
The present invention relates to novel micro or mesoporous metal organic frameworks (MOFs) which contain as ligands piperidine based phosphonic acids, as well as a method of synthesizing such MOFs and uses of the MOFs themselves.
1. A porous isoreticular metal organic framework (MOF) comprising an organic compound co-ordinated to at least one metal selected from the group consisting of Co, Ni, Mg, Mn, Fe, Zn, Cd and Ru, wherein the organic compound is of the formula
PO 3 CH 2 X—Y—XCH 2 PO 3
wherein X is a substituted or unsubstituted heterocyclic amine containing one or more amine groups and Y forms a link between each group and is selected from the group consisting of a single bond, —(CH 2 ) n — where n is greater than or equal to 1,
and a cyclic or heterocyclic substituted or unsubstituted ring structure.
2. The porous MOF according to claim 1 wherein the metal is selected from the group consisting of Co, Ni, Mn, Mg, Fe and mixtures thereof.
3. The porous MOF according to claim 1 wherein X is a fully saturated heterocyclic amine ring structure.
4. The porous MOF according to claim 1 wherein one or more available atoms on X is substituted by a functional group selected from the group consisting of C 1 -C 4 alkyl, hydroxy, amino, nitro, and halo, where halo is selected from the group consisting of bromo, chloro, and iodo.
5. The porous MOF according to claim 1 , wherein Y is a substituted or unsubstituted benzene ring.
6. The porous MOF according to claim 1 , wherein the organic compound is 4,4′-N,N′-bipiperidinylbis(methylenephosphonate).
7. The porous MOF according to claim 1 , wherein the MOF has large regular pore structures of at least 1.5 nm in diameter.
8. The porous MOF according to claim 1 which has a porosity of at least 0.5 cm 3 g −1 .
9. A method of making a MOF in accordance with claim 1 , the method comprising the step of reacting a suitable base with at least one type of divalent metal cation and an organic acid of the formula:
H 2 PO 3 CH 2 X—Y—XCH 2 PO 3 H 2 ,
in aqueous solution, wherein X and Y are as defined in claim 1 , under hydrothermal reaction conditions, to thereby form a MOF.
10. The method according to claim 9 , wherein the base is sodium or potassium hydroxide, and the base is added in an amount sufficient to adjust the pH of the solution and to assist dissolution of the acid form of the ligand.
11. The method according to claim 9 , wherein the molar ratios of the starting materials range from: divalent metal cation:bisphosphonic acid: base: H 2 O=0.5-2:1:0.5-2:1000-1500.
12. A method of uptake of one or more substances, the method comprising combining the porous MOF according to claim 1 with a substance selected from a gas, liquid and drug molecule, to thereby result in uptake of the substance in the pores of the MOF.
13. The method of claim 12 , further comprising a step selected from the group consisting of storing, separating, controllably releasing and chemically reacting the substance taken up in the pores of the porous MOF.
14. The porous MOF of claim 3 , wherein X is a piperidine ring, optionally substituted at one or more positions with a functional group selected from the group consisting of C 1 -C 4 alkyl, hydroxy, amino, nitro, and halo.
15. The porous MOF of claim 5 , wherein Y is a substituted benzene ring having one or more positions substituted with a nitro, amino, or halo group.
16. The porous MOF according to claim 1 , having a porosity of at least 0.6 cm 3 g −1 or higher.
17. A porous isoreticular metal organic framework (MOF) comprising an organic compound co-ordinated to at least one metal selected from the group consisting of Co, Ni, Mg, Mn, Fe, Zn, Cd and Ru, wherein the organic compound is of the formula
PO 3 CH 2 X—Y—XCH 2 PO 3
wherein X is a substituted or unsubstituted heterocyclic amine containing one or more amine groups and Y forms a link between each group and is a substituted or unsubstituted benzene ring.
18. The porous MOF according to claim 17 , wherein Y is a substituted benzene ring having one or more positions substituted with a nitro, amino, or halo group.