Metal-organic framework based molecular traps for capture of radioactive organic iodides from nuclear waste

1. A method of capturing radioactive iodide, comprising contacting a substance containing a radioactive iodide with a complex comprising

a) a compound of Formula M 3 (O)X b [(O 2 C)—Y—(CO 2 )] 3 (Z) c , wherein

M is a transition metal with an oxidation state of +3 or +4;

Y is an optionally substituted aryl or heteroaryl;

X is an anion having 1 or 2 negative charges;

Z is a neutral molecule capable of coordinating to M;

b is 1 or 2;

c is 0 or 1;

and

b) one or more nitrogen-containing functional molecules, wherein said one or more two functional molecules each contain at least two nitrogens, and one of said at least two nitrogens is coordinated to the M.

2. The method of claim 1 , wherein the radioactive iodide is methyl iodide.

3. The method of claim 1 , wherein the radioactive iodide forms an irreversible bonding with the complex.

4. The method of claim 1 , further comprising treating the complex after capturing the radioactive iodide to regenerate M 3 (O)X b [(O 2 C)—Y—(CO 2 )] 3 (Z) a , wherein

M is a transition metal with an oxidation state of +3 or +4;

Y is an optionally substituted aryl or heteroaryl;

X is an anion having 1 or 2 negative charges;

Z is a neutral molecule capable of coordinating to the M;

a is 1 or 2;

b is 1 or 2.

5. The method of claim 1 , wherein b is 1.

6. The method of claim 1 , wherein c is 0, and wherein two of the functional molecules are coordinated to a cluster of the Ms.

7. The method of claim 1 , wherein the M is selected from the group consisting of Cr, Mo, Fe, Al, Zr and Ti.

8. The method of claim 1 , wherein the M is a +3 oxidation state metal selected from the group consisting of Cr, Mo, Fe, and Al, and Y is optionally substituted with a substituent selected from the group consisting of —OR 1 , —SR 1 , —SR 1 , —C 1 -C 4 alkyl, —NO 2 , —CN and —NR a R b , wherein R 1 at each occurrence is independently hydrogen (H) or C 1 -C 4 alkyl, and R a and R b are independently hydrogen, or C 1 -C 4 alkyl.

9. The method of claim 1 , wherein M is Cr 3+ .

10. The method of claim 1 , wherein the complex is a porous crystalline material.

11. The method of claim 1 , wherein said one or more functional molecules independently have a formula of R 1 R 2 NLNR 3 R 4 , wherein,

L is void or a C 1-4 linker optionally substituted with a C 1-4 alkyl; and

each of R 1 , R 2 , R 3 and R 4 are independently selected from the group consisting of H, methyl, ethyl, propyl, and isopropyl, or

R 1 and R 3 and/or R 2 and R 4 link up to form a C 2-4 alkyl chain, wherein each of said C 2-4 alkyl chain optionally and independently has a carbon replaced with a heteroatom or group selected from the group consisting of NR 5 , S, and O, wherein R 5 is H or C 1-4 alkyl, or two R 5 link up to form a C 1-2 alkyl chain.

12. The method of claim 11 , wherein L is void and each of R 1 , R 2 , R 3 , and R 4 is independently H or methyl.

13. The method of claim 11 , wherein L is a C 2 linker.

14. The method of claim 11 , wherein L is a C 2 linker, and R 1 and R 3 link up to form a C 2 linker.

15. The method of claim 1 , wherein the complex comprises one or two functional molecules each containing at least one tertiary amine and at least one primary or secondary amine.

16. The method of claim 1 , wherein the complex comprises two functional molecules each containing at least two tertiary amines.

17. The method of claim 1 , wherein said one or more functional molecules are selected from the group consisting of triethylenediamine (TED), hexamethylenetetramine (HMTA), N,N-dimethylethylenediamine (DMEDA), N,N-dimethyl-1,3-propanediamine (DMPDA) and N,N-dimethyl-1,4-butanediamine (DMBDA).

18. The method of claim 1 , wherein the complex is a porous crystalline material having an average pore diameter between about 10 Å and 21 Å.

19. The method of claim 1 , wherein b is 2.

20. The method of claim 1 , wherein the radioactive iodide forms an irreversible bonding with another of said at least two nitrogens.