19th Annual Student Research Conference
Science
Mechanisms for the Alkaline Hydrolysis and Perhydrolysis of a VX Simulant
Rebecca S. Hanania* and Ashley N. Jay
Dr. Eric V. Patterson, Faculty Mentor
The mechanism for the neutralization of the nerve agent VX by either alkaline hydrolysis or perhydrolysis is thought to begin with a nucleophilic attack at phosphorous giving a trigonal bipyramidal (TBP) intermediate structure with the alkoxide group in an apical position. This can be followed by cleavage of the P-O bond, or one or more pseudorotations to different TBP structures followed by P-O or P-S bond cleavage. Using a simulant (a simpler molecule with similar structure and reactivity), the energy of each transition state and intermediate was determined computationally for each pseudorotation reaction pathway. Density functional theory was used to obtain optimized structures and vibrational frequencies, and molecular orbital theory was used to obtain electronic and solvation energies. The calculations are consistent with experimental data, which show that hydrolysis of VX results in either P-S bond cleavage or P-O bond cleavage, whereas perhydrolysis results only in P-S bond cleavage.
Keywords: computational chem, VX, nerve agent, hydrolysis, perhydrolysis, pseudorotation
Topic(s):Chemistry
Presentation Type: Oral Paper
Session: 26-2
Location: VH 1432
Time: 10:00