Chemical Warfare Agent Surface Adsorption: Hydrogen Bonding of Sarin and Soman to Amorphous Silica

Abstract

Sarin and soman are warfare nerve agents that represent some of the most toxic compounds ever synthesized. The extreme risk in handling such molecules has, until now, precluded detailed research into the surface chemistry of agents. We have developed a surface science approach to explore the fundamental nature of hydrogen bonding forces between these agents and a hydroxylated surface. Infrared spectroscopy revealed that both agents adsorb to amorphous silica through the formation of surprisingly strong hydrogen-bonding interactions with primarily isolated silanol groups (SiOH). Comparisons with previous theoretical results reveal that this bonding occurs almost exclusively through the phosphoryl oxygen (P═O) of the agent. Temperature-programmed desorption experiments determined that the activation energy for hydrogen bond rupture and desorption of sarin and soman was 50 ± 2 and 52 ± 2 kJ/mol, respectively. Together with results from previous studies involving other phosphoryl-containing molecules, we have constructed a detailed understanding of the structure-function relationship for nerve agent hydrogen bonding at the gas-surface interface.

Spectroscopic investigation of substrates contaminated by chemical warfare agents

“…8a) and is attributed to d s (C-C-C). 38 In general, the peak positions are in good agreement with reported literature data 34,[38][39][40] (including the C-H frequencies 34,38,39 ).…”

Multidisciplinary Role of Mesoporous Silica Nanoparticles in Brain Regeneration and Cancers: From Crossing the Blood–Brain Barrier to Treatment

“…In the year 2012, Wilmsmeyer et al, showed that common stimulant, an organophosphorus compound, namely DMMP (dimethyl methylphophonate) binded hydrophilic silica more significantly than DMCP (dimethyl chlorophosphate), indicating that the sarin phosphorus‐halogen bond affects the surface chemistry of the agent in a complicated way . Then in the year 2014, Davis et al studied the energetics and mechanisms that regulated the hydrogen‐bonding interactions when soman and sarin adsorb on silica . In the same year, Li and coworkers evaluated the effect of MSNs on detoxification of toxic DMMP and according to them, MSNs is an ideal promising adsorbent agent owing to their high specific surface area, dense Si‐OH surface groups, and large pore volume .…”

“…It would be possible to store sufficient amount of drugs in several inner pores and release them via appropriate channels speedily without any surface polymer barriers. MSNs belong to a family of classic sponge‐like nanomaterials that can be potential decontaminating agents or NAs destroyers owing to their good biocompatibility and rapidly absorbing nature . Yang et al in their studies presented a detoxification system (DS) composed of MSNs functionalized with a brain‐targeted protein coatings that were endowed with HI‐6 reactivators for effective targeting of soman‐inhibited AChE in the brain .…”

Effective removal of chemical warfare agent simulants using water stable metal–organic frameworks: mechanistic study and structure–property correlation

“…43 Then, the hydrogen bond between the hydroxyl groups in the metal nodes and the elements, chlorine and sulfur of 2-CEES and/or C which may be responsible for intra-particle diffusion and further binding of the adsorbate. [43][44][45][56][57][58][59][60] The carboxylic group of the TBAPy ligand also adds to the strength of hydrogen bonding. Hence, the result of the various interactions between the 2-CEES and/or C and NU-1000 act as a strong chemical bond.…”

“…Among several methods to remove toxic chemicals, adsorptive removal is signicant, due to its simple operation and cost effectiveness. 34,[41][42][43][44][45][46][47][48][49] There are few reports where MOFs are used for this purpose, but the mechanism of these types of adsorption processes is still ambiguous. In the present work, we have used Zr-based MOFs (NU-1000 and UiO-67) for the efficient adsorption and removal of CWA simulants, (or namely) 2-CEES and DMMP from the aqueous medium.…”