A group of chemists co-led by Dr Joseph Hupp and Dr Omar Farha, both from Northwestern University, has developed a new material that is very effective at destroying toxic nerve agents.
Molecular representations of the NU-1000 node and linker (left), MOF topology (two views, center), and the dehydration of the NU-1000 node (right). Zr – blue, O – red, C – black, H – white. Image credit: Joseph E. Mondloch et al.
The new material – a zirconium-based metal-organic framework (MOF) named NU-1000 – degrades in minutes soman, one of the most toxic chemical agents known to mankind. Computer simulations show it should be effective against other easy-to-make agents, such as VX.
MOFs are well-ordered, lattice-like crystals. The nodes of the lattices are metals, and organic molecules connect the nodes. Within their very roomy pores, MOFs can effectively capture gases, such as nerve agents.
NU-1000 has nodes of zirconium – the active catalytic site where all the important chemistry takes place. The organic ligand gives the material its important structure by connecting the nodes, but it does not participate in the catalysis of the nerve agent.
The zirconium node selectively clips the phosphate-ester bond in the nerve agent, rendering it innocuous. With the critical bond broken, the rest of the molecule is left alone. The bond is broken through the process of hydrolysis, a reaction involving the breaking of a molecule’s bond using water. The MOF can use the humidity in the air.
“This designed material is very thermally and chemically robust, and it doesn’t care what conditions it is in. The material can be in water or a very humid environment, at a temperature of 130 degrees or minus 15, or in a dust storm. A soldier should not need to worry about under what conditions his protective mask will work. We can put this new catalyst in rugged conditions, and it will work just fine,” said Dr Farha, who is a co-author of the study published in the journal Nature Materials.
NU-1000 is inspired by the enzyme phosphotriesterase, which is found in bacteria. The natural enzyme has two zinc ions bridged by a hydroxyl group as the active catalytic site.
Dr Hupp, Dr Omar Farha and their colleagues first tested NU-1000 against the soman simulant DMNP and found the material degraded half of the target in less than 1.5 minutes.
Next, they tested it against soman and found the catalyst degraded half of the nerve agent in less than 3 minutes.
“These half-lives are very impressive and show how well the catalyst is working,” Dr Farha said.
The scientists also tested the zirconium cluster alone, without the cluster being in the MOF structure, and the catalyst was not as effective at degrading the nerve agent. This shows the importance of the MOF scaffold.
“Our catalyst is fantastic compared to other catalysts, but there is still more work to be done,” Dr Farha said.
_____
Joseph E. Mondloch et al. Destruction of chemical warfare agents using metal–organic frameworks. Nature Materials, published online March 16, 2015; doi: 10.1038/nmat4238
![Chemical structure of the cyclo[48]carbon [4]catenan. Image credit: Harry Anderson.](https://cdn.sci.news/images/2025/08/image_14141-Cyclo-48-Carbon-104x75.jpg)
