A Study of the Kinetics of La3+-Promoted Methanolysis of S-Aryl Methylphosphonothioates: Possible Methodology for Decontamination of EA 2192, the Toxic Byproduct of VX Hydrolysis

摘要: The kinetics of the La3+-catalyzed methanolysis a series S-aryl methylphosphonothioates (4a−e, phenyl substituents = 3,5-dichloro, 4-chloro, 4-fluoro, 4-H, 4-methoxy) were studied at 25 °C with sspH control. reaction involves saturation binding anionic substrates to dimeric La3+/methoxide catalysts formulated as La23+(−OCH3)x, where x 2−5 depending on solution sspH. Cleavage La3+-bound is fast, ranging from 5 × 10−3 s−1 5.5 10−5 for 4a−e 8.4 and 1.6 10−1 4 10−3s−1 11.7. rate accelerations 4a−e, relative their background methoxide-promoted reactions, average 7 1010 1.5 109, respectively, sspH’s catalytic system predicted cleave EA 2192 (S-2(N,N-di-iso-propylaminoethyl) methylphosphonothioate), toxic byproduct hydrolysis VX, t1/2 between 8 min 8.4, 27