Surface Tension of Organophosphorus Compounds: Sarin and its Surrogates

Abstract

While the production and stockpiling of organophosphorus chemical warfare agents (CWAs), such as sarin, was banned three decades ago, CWAs have remained a threat. New approaches for decontamination and destruction of CWAs require detailed knowledge of their various physicochemical properties. In particular, surface tension is needed to describe the formation and evolution of hazardous aerosols when CWA liquids are dispersed in the air. Due to the extreme toxicity of sarin, most experimental studies are carried out using its surrogates�organophosphorus compounds which, while having similar structures, are much less toxic, e.g., dimethyl methylphosphonate (DMMP) and diisopropyl methylphosphonate (DIMP). However, not only for sarin, but also for its surrogates, literature data on the surface tension are scarce.Here we present experimental measurements and computational predictions of the surface tension of DMMP and DIMP. Classical molecular dynamics simulations using the Transferable Potentials for Phase Equilibria (TraPPE) force field produced an excellent agreement with the experimental results in the temperature range from 3 to 60 °C, validating the predictive capability of TraPPE. Consequently, we applied the TraPPE force field to sarin. Our modeled values for the sarin surface tension cover the range of temperatures from 0 to 85 °C, and the four experimental data points from the literature measured between 20 and 35 °C agree perfectly with our predictions. The temperature-dependent surface tension values for sarin and its surrogates obtained in our study can be used in models predicting the formation and evolution of aerosols made of these chemicals. Furthermore, our results justify the use of the TraPPE force field to derive the thermodynamic properties of other organophosphorus compounds with structures similar to the ones studied here.

Defective MOF-74 with ancillary open metal sites for the enhanced adsorption of chemical warfare agent simulants

“…The CWA simulants can also be present as an aerosol in the air. 67,68 CWA simulants in the liquid phase as well as those in the vapor phase are known to interact with adsorbents, such as polar-polar interaction, hydrogen bonding, hydrophobic–hydrophobic interaction. 14–18…”

“…The CWA simulants can also be present as an aerosol in the air. 67,68 CWA simulants in the liquid phase as well as those in the vapor phase are known to interact with adsorbents, such as polar-polar interaction, hydrogen bonding, hydrophobic-hydrophobic interaction. [14][15][16][17][18] Furthermore, the uptake of other CWAs such as DMMP and MS by pure MOF-74 and a series of D-MOF-74 samples was analyzed using the same jar-in-jar setup.…”

Assessment of Acetylcholinesterase Activity Using the Gold Nanocluster–MnO2 Nanosheet Pair for Detection of Paraoxon

“…The inhibition of AChE facilitates the aggregation of excess acetylcholine at the neuromuscular junction, resulting in many psychiatric and neurological disorders such as respiratory distress of the central nervous system, bronchial secretion at the muscarinic receptor, and skeletal muscle paralysis at the nicotinic receptor, which leads to death. 19 Therefore, the identification of these toxicants is a challenging task because the molecular-level reaction is very sensitive and precise. 20−23 Here, we report a versatile vitamin B 1 -stabilized highly bright-blue emissive gold nanocluster (VB 1 −AuNC)-based fluorescent sensor for the detection of neurotoxic OPs through the involvement of the FRET (Forster resonance energy transfer) mechanism (Scheme 1).…”

Cobalt and zinc nanoparticles from pyrolysis of their MOF precursors exhibiting potent organophosphorus hydrolase-mimicking activities

“…Organophosphorus compounds (OPCs) and their various derivatives are widely used as organophosphorus nerve agents and pesticides, 1,2 such as sarin, VX, parathion, and fenitrothion. OPCs contain phosphate ester bonds.…”