Nerve Agent Degradation with Polyoxoniobates

Polyoxoniobates are exceptional amongst polyoxometalates in that they can potentially perform base catalysis in water, a process in which a proton is bonded to an oxo ligand, and a hydroxyl is released. Catalytic decomposition of chemical warfare agents such as organofluorophosphates that were used recently in the infamous civilian attacks in Syria is one opportunity to employ this process. Upon evaluation of the polyoxoniobate Lindqvist ion, [Nb6O19](8-), fast neutralization kinetics was discovered for the breakdown of the nerve agent simulant diisopropyl fluorophosphate (DFP). The polyoxoniobates were also tested against the nerve agents Sarin (GB) and Soman (GD). It was determined that different Lindqvist countercations (Li, K, or Cs) affect the rate of decomposition of the organophosphate compounds in both aqueous media (homogeneous reaction), and in the solid state (heterogeneous reaction). Small-angle X-ray scattering analysis of solutions of the Li, K, and Cs salts of [Nb6O19](8-) for concentrations at which the experiments were performed revealed distinct differences that could be linked to their relative reaction rates. This study represents the first demonstration of exploiting the unique alkaline reactivity of polyoxoniobates for nerve agent decontamination.