Computational evaluation of the chemical warfare agents capture performances of robust MOFs

A series of stable MOFs containing zirconium or titanium ions as metal centers was screened to assess their capture performances for nerve agents including sarin and soman as well as their standard simulants, i.e. the dimethyl-methyl-phosphonate and diisopropyl fluorophosphate. These Monte Carlo simulations revealed that some of these MOFs show very high uptakes that significantly outperform those of other families of porous materials and interestingly they exhibit a very high affinity for these toxic molecules at low loading. These combined features make them potentially attractive to act as nerve agent filters. This set of adsorption data was further rationalized to establish structure-adsorption performances relationship and Monte Carlo simulations were combined with Density Functional Theory calculations to gain more insight into the adsorption mechanism in play. Finally, the choice of reliable simulants to accurately mimic the adsorption behavior of real toxic molecules in MOFs has been further discussed and in particular it has been established that soman is better described considering the pinacolyl methylphosphonate rather than the standard dimethyl-methyl-phosphonate and diisopropyl fluorophosphate simulants.