19th Annual Student Research Conference
Science
Computational Chemical Studies of Alkaline Hydrolysis of VX Nerve Agent
Kelly A. Daniel
Dr. Eric V. Patterson, Faculty Mentor
O-ethyl S-(2-(diisopropylamino)ethyl) methylphosphonothiolate (VX), is a nonvolatile liquid chemical warfare agent that is unusually persistent in the environment. VX is a potent irreversible acetylcholinesterase inhibitor with an LD50 of only 3.5 mg/70 kg man. Exposure to a lethal dose of VX results in convulsions, loss of muscle control and death through asphyxiation within 15 minutes. Neutralization of this deadly nerve agent requires cleavage of the P-S bond. Hydrolysis in alkaline solution results in both P-S (87%) and P-O (13%) bond cleavage, with the product from P-O bond cleavage remaining highly toxic. The potential energy surface for the reaction of hydroxide with VX has been computed at the MP2/6-31+G(d)//MPW1K/MIDI! level of theory, with corrections added for thermodynamic and solvation effects. Results indicate that hydroxide attack opposite the P-O bond is slightly favored, but that processes leading to P-S bond cleavage are more favorable than direct P-O bond cleavage.
Keywords: Computational Chem, VX, Nerve Agents, Hydrolysis
Topic(s):Chemistry
Presentation Type: Oral Paper
Session: 41-5
Location: VH 1408
Time: 2:15