Molecular Modeling of Organophosphorous Agents and Their Aqueous Solutions

Vishnyakov, Aleksey; Gor, Gennady Y.; Lee, Ming‐Tsung; Neimark, Alexander V.

doi:10.1021/jp200509u

Cited by 21 publications

(47 citation statements)

References 41 publications

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“…Observed similarities between adsorption equilibrium of sarin and DMMP are consistent with experimental measurements 1 and recent works. 40,41 Because DMMP is commonly used in both static and dynamics adsorption measurements, we further focus on the DMMP adsorption.…”

Section: Resultsmentioning

confidence: 99%

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Screening of carbonaceous nanoporous materials for capture of nerve agents

Kowalczyk

Gauden²,

Terzyk³

et al. 2013

Phys. Chem. Chem. Phys.

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A strategy for combined experimental and computational screening of candidate carbonaceous materials for capturing highly volatile nerve agents at ambient temperature using physisorption. Based on theoretical calculations of Henry constants and zero-coverage adsorption enthalpies for sarin and DMMP (its common stimulant) adsorbed in model slit-shaped carbon pores at 298 K, we found the following. Slit-shaped carbon pores with pore width ~0.5 nm are optimal for agent adsorption due to strong confinement of adsorbed molecules. Agent adsorption enthalpy at zero coverage computed for optimal pore width is very high and reaches ~83 kJ mol(-1). Widening of pore width above ~1 nm results in a significant decrease of the Henry constant and zero-coverage adsorption enthalpy (~44 kJ mol(-1)). Polydispersity of studied candidate carbonaceous materials strongly affects adsorption capacity for DMMP under the operating conditions. The optimal carbonaceous adsorbent, pitch-based P7 activated carbon fiber, adsorbed ~100 μg g(-1) DMMP at 0.03 μg m(-3). Commercial Norit activated carbon adsorbed only ~20 μg g(-1) DMMP at 0.03 μg m(-3). Surprisingly, a small shift of the pore size distribution towards wider micropores has a great impact on agent adsorption. Because the adsorption enthalpies computed at zero coverage weakly dependent on pore size, the heat released during agent adsorption is similar for all studied candidate adsorbents (i.e.~55-60 kJ mol(-1)).

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Section: Resultsmentioning

confidence: 99%

“…DMMP is a highly polar molecule, and as many warfare agents, is acidic in nature. 40,41 Therefore, pore surface chemistry may enhance adsorption affinity. This and other aspects of nerve agent capture by physisorption will be subject of our future works.…”

Section: Carbonaceousmentioning

confidence: 99%

Screening of carbonaceous nanoporous materials for capture of nerve agents

Kowalczyk

Gauden²,

Terzyk³

et al. 2013

Phys. Chem. Chem. Phys.

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“…It was shown previously that the resulting thermodynamic properties of DMMP varied significantly based on the force fields used to describe the molecules. 27,30 There are three force fields reported in the literature for DMMP 24,30,31 and one for sarin [transferable potentials for phase equilibria (TraPPE)], 30 but all of them are not properly documented, as shown below. Therefore, in this work, our goal was to summarize the existent force fields for sarin and DMMP molecules with the corrected parameters based on the communication with the force fields' authors.…”

Section: ■ Introductionmentioning

confidence: 99%

Force Fields for Molecular Modeling of Sarin and its Simulants: DMMP and DIMP

et al. 2021

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Even three decades after signing the Chemical Weapons Convention, organophosphorus chemical warfare agents (CWAs), such as sarin, remain a threat. The development of novel methods for the detection of CWAs, protection from CWAs, and CWA decontamination motivates research on their physicochemical properties. Due to the extreme toxicity of sarin, most of the experimental studies are carried out using less toxic simulant compounds. In addition to experimental studies of sarin simulants, both sarin and simulants can be studied using in silico experimentsmolecular simulations. The results of classical molecular modeling of the compounds and their agreement with experimental data rely on the force field used to describe the system. In recent years, there have been several force fields proposed for sarin and its most common simulant dimethyl methylphosphonate (DMMP). However, other simulants frequently used in experiments received less attention from the molecular simulation perspective, for example, to date, there is no force field and no simulation data for diisopropyl methylphosphonate (DIMP). Here, we compare the literature force fields for sarin and DMMP, focusing specifically on the vapor–liquid equilibrium for the pure species. We carried out Monte Carlo and molecular dynamics simulations using the existing literature force fields from which we predicted the liquid densities and vapor pressures developing the entire binodal curves. We compared the predictions to the experimental data and showed that the TraPPE-UA force field outperformed the other force fields. Thus, we extended TraPPE-UA for DIMP, utilized this force field in molecular simulations, and predicted the liquid densities and vapor pressures for a range of temperatures (binodal curve), which agreed well with the published experimental data. From the binodal, we calculated the critical properties of DIMP and demonstrated that these parameters can be used in the Peng–Robinson equation of state for this compound.

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“…Computer simulations generally consider gas phase structures. While these are of interest, particularly for sensor applications, it is also important to understand what occurs in aqueous solution, as investigated by the groups of Ault and Neimark, because atmospheric moisture is likely to affect detection (28)(29)(30).…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic and inclusion properties of G-series chemical warfare agents and their simulants: a DFT study

Sambrook

Gass

Cragg

2017

Supramolecular Chemistry

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A computational protocol to predict the infrared spectra of chemical warfare agents (CWAs) tabun (GA), sarin (GB), soman (GD) and cyclosarin (GF) has been developed. Sarin was used to benchmark the method through gas phase simulations. DFT calculations using the EDF2 functional and diffuse 6-311++G** basis set was found to give the closest match to experimental infrared spectra. Using the same functional the 6-31G (2df, 2p) basis set was found to be superior when hydrated sarin was modelled. GA, GB, GD and GF, together with 11 commonly used simulants, were modelled in the gas and hydrated states. Complexes of GB and a number of CWA mimics with α-cyclodextrin were modelled to give insight into their different modes of inclusion

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Molecular Modeling of Organophosphorous Agents and Their Aqueous Solutions

Cited by 21 publications

References 41 publications

Screening of carbonaceous nanoporous materials for capture of nerve agents

Screening of carbonaceous nanoporous materials for capture of nerve agents

Force Fields for Molecular Modeling of Sarin and its Simulants: DMMP and DIMP

Spectroscopic and inclusion properties of G-series chemical warfare agents and their simulants: a DFT study

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