2-chloroethyl Phenyl Sulfide Research Articles

New microemulsions for oxidative decontamination of mustard gas analogues and polymer-thickened half-mustard

Chemical decontamination of toxic compounds (warfare agents and pesticides) is of increasing importance. In this study, we report the oxidation of mustard gas analogues in microemulsion media. A first formulation, very well-suited for stock-pile destruction, allows a fast, quantitative and chemoselective oxidation of the analogues. In a second formulation, the choice of microemulsion components used allowed us to study the oxidation of a polymer-thickened half-mustard (2-chloroethylphenyl sulfide), opening the field of application of these microemulsions to on-site decontamination. These results confirm both the efficiency and potential of microemulsions for mustard gas destruction/decontamination in essentially aqueous systems.

Reactions of VX, HD, and Their Simulants with NaY and AgY Zeolites. Desulfurization of VX on AgY

The room-temperature reactions of the chemical warfare agents VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothioate), HD (2,2‘-dichloroethyl sulfide, or mustard), and their common simulants, O,S-diethyl phenylphosphonothioate (DEPPT) and 2-chloroethyl phenyl sulfide (CEPS), with NaY and silver-exchanged (AgY) zeolites have been studied using solid-state magic angle spinning NMR. VX hydrolyzes via exclusive cleavage of the P−S bond on both NaY and AgY to yield ethyl methylphosphonate (EMPA). The reaction is significantly faster on AgY than on NaY, suggesting catalysis by silver. On AgY, an intermediate silver salt of EMPA is apparently formed which is slowly converted to ethyl 2-(diisopropylamino)ethyl methylphosphonate (QB, the desulfurized analogue of VX) in about a 78% yield. DEPPT similarly hydrolyzes via P−S cleavage on AgY to yield an apparent silver salt of ethyl phenylphosphonate, which does not undergo further reaction to the desulfurized analogue. No reaction is observed for DEPPT on NaY. HD on AgY forms both vinyl sulfide and the cyclic ether 1,4-thioxane. HD reacts faster on NaY to exclusively form the CH-TG sulfonium ion (HOCH2CH2SCH2CH2S+[CH2CH2OH]2). CEPS also reacts faster on NaY, forming 2-hydroxyethyl phenyl sulfide. On AgY, CEPS does not give the vinyl product, but does yield the ether product PhSCH2CH2OCH2CH2SPh. A mechanism is proposed for the silver-catalyzed hydrolysis of VX, the desulfurization of the cleaved thiol, and the formation of QB.

Reaction of a Vesicular Functionalized Surfactant with 2-Chloroethyl Phenyl Sulfide, a Mustard Simulant

Functionalized double-chain surfactant 1 (potassium O,O‘-didodecylphosphorodithioate) was synthesized. Its small unilamellar vesicles were characterized by dynamic laser light scattering and differential scanning calorimetry and its giant vesicles by phase-contrast optical microscopy. Also, 1's giant vesicles containing fluorescent dye 4a (5-carboxyfluorescein) or 4b [5-(dodecanamido)fluorescein] were characterized by epifluorescence microscopy. In a pH 9.0 borate buffer at 25 °C, vesicular 1 reacted with 2 (2-chloroethyl phenyl sulfide), a simulant for the chemical warfare agent mustard [bis(2-chloroethyl) sulfide], to give 5 [S-[(2-phenylthio)ethyl] O,O‘-didodecylphosphorodithioate], involving capture of reactive intermediate cation 9 (1-phenylthiocyclopropane) by the anion of 1. This reaction was accompanied by the precipitation of 5, which resulted in wounding/destruction of the vesicles and the release of dye 4a (from giant vesicles). The combination of the conversion of 2 into 5 and dye release sugg...

Degradation and Fate of Mustard in Soil As Determined by 13C MAS NMR

The environmental fate of chemical warfare agents is a current concern, and the notorious persistency of mustard in soil is well-known. The current study utilizes 13C MAS NMR as an in situ method to study the behavior of mustard, and the common simulants 2-chloroethyl methyl sulfide (CEMS) and 2-chloroethyl phenyl sulfide (CEPS), in a sandy loam soil. Spreading of these water-insoluble liquids and surface sorption on the dry soil particles is observable, as is the recoalescence of liquid droplets and/or hydrolysis in the presence of added water. The relative hydrolysis rates are in agreement with those observed in solution. CEMS, possessing the shortest aqueous half-life, hydrolyzes without droplet reformation. But mustard and CEPS, possessing much longer aqueous half-lives, do not substantially hydrolyze prior to droplet reformation. For mustard, this behavior is crucial to its longevity in soil. Hydrolysis of CEMS and CEPS in the sandy loam soil yields predominately their corresponding alcohols, with some ether formation for the latter. Mustard hydrolysis in the sandy loam soil results in the nearly exclusive formation of the branched sulfonium ion HOCH2CH2SCH2CH2S+(CH2CH2OH)2 (CH-TG). A simple model based on droplet size is presented to explain the persistency of mustard in soil.

Oxidation of sulfides by 3-hydroperoxy-4,4,5,5-tetramethyl-3-phenyl-1,2-dioxolane: Effect of solvent and sulfide substituent

The reaction of 3-hydroperoxy-4,4,5,5-tetramethyl-3-phenyl-1,2-dioxolane, 1, with a series of sulfides (2a = thioanisole, 2b = ethyl phenyl sulfide, 2c = 2-chloroethyl phenyl sulfide, and 2d = 2-chloroethyl methyl sulfide) at 34°C in various solvents yielded the corresponding sulfoxides and 3-hydroxy-1,2-dioxolane 3 in quantitative yields. The oxidations showed excellent second-order kinetic behavior overall. In CDCl3, the reactivity order was 2d > 2b > 2a > 2c. For 2a, the relative rate in various solvents was CDCl3 (17); CD3OD (7); C6D6 (∼3); CD3CN (1); CD3C(O)CD3 (∼0.3). Addition of ∼1 equivalent of acetic acid to reactions of 1 and 2a in CDCl3 and C6D6 resulted in small increases in the values of k2. The results are consistent with an electrophilic oxygen-atom transfer mechanism similar to that proposed for oxidations by α-azohydroperoxides. Since the precursor to 1, 3-hydroxy-1,2-dioxolane 3, is regenerated during the oxidation, the system has the potential to be developed as a cyclic process. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:75–78, 1998

Reactions of the mustard simulant 2-chloroethyl phenyl sulfide with self-decontaminating sorbents. A 13C MAS NMR study

Decomposition reactions for the mustard simulant 2-chloroethyl phenyl sulfide ( 13C-labelled, CEPS∗) sorbed on γ-alumina, polydivinylbenzene (impregnated with NaOH, polyethylene glycol and polyethylenimine) ( DVB NaOH ), and Ambergard ® XE-555, were characterized in situ using 13C MAS NMR. CEPS∗ hydrolyzes on γ-alumina to form 2-hydroxyethyl phenyl sulfide. On DVB NaOH , CEPS∗ eliminates HCl to yield vinyl phenyl sulfide. No products were observed on XE-555, where the applied CEPS∗ was spectroscopically observed to adsorb entirely within the micropores of the carbonaceous resin component of this material. Toxicities of the mustard products analogous to the degradation products observed for CEPS∗ are discussed.

Magic Angle Spinning NMR Study of Adsorbate Reactions on Activated Charcoal

Magic angle spinning (MAS) NMR can distinguish between molecules adsorbed in monolayers within the micropores (>20 A) of activated charcoal and those present in multilayers or capillary-condensed liquid in the mesopores (20-500 A). The differentiation is possible due to the NMR shifts to low frequency induced by the large, diamagnetic susceptibility of the graphitic surface of the micropores (upon which primary adsorption occurs) in combination with slow molecular exchange between the micropores and mesopores. This study uses MAS NMR to characterize the adsorption and oxidation of 2-chloroethyl phenyl sulfide (CEPS) on activated charcoal. Micropore-filling by solvents and solvent displacement of micropore-adsorbed CEPS are also demonstrated for charcoal using this technique