Detoxification of VX by Chloramine-B. Final report, August 1989-April 1992
At ambient temperature, the nerve agent O-ethyl S-2(diisopropylamino)ethyl methylphosphonothiolate (VX), can be detoxified in an aqueous solution of Chloramine-B CAB, C6H5SQ2N(Cl)Na only in the presence of sufficient acid (pH 3). The thiolo sulfur is first attacked by the reactive species, benzene chlorosulfonamide, to form a chlorosulfonium ion intermediate followed by hydrolysis and substitution reactions with the sulfonamide anion at the P-S bond. These reactions produce strongly acidic products, which further accelerate the initial reaction. Consequently, one of the acidic hydrolysis products of VX, the toxic S-2-(diisopropylamino)ethyl methylphosphonothioic acid (EA 2192) reacts with CAB instantaneously. This acid-catalyzed mechanism is similar to that reported for bivalent sulfides; direct attack by active chlorine is considered insignificant. A neutral VX analog, O,S-diethyl methylphoshonothiolate, reacts with CAB rapidly in H20 with an initial pH of 8.9 but requires the addition of 0.006 N (H+) for the reaction to occur in D20. By comparison, bivalent sulfides are more reactive than the phosphonothiolates, in general, and can be rapidly oxidized in both H20 and D20, even at high pH values. Chloramine-B, VX, Bivalent sulfide, Benzenechlorosulfonamide, Thiolo sulfur, Phosphonothiolate.
- Research Organization:
- Edgewood Research, Development and Engineering Center, Aberdeen Proving Ground, MD (United States)
- OSTI ID:
- 5674506
- Report Number(s):
- AD-A-273006/7/XAB; ERDEC-TR-032
- Country of Publication:
- United States
- Language:
- English
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