| Title : 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 - Dhar_2011_Inorg.Chem_50_3071 |
| Author(s) : Dhar BB , Edwards DR , Brown RS |
| Ref : Inorg Chem , 50 :3071 , 2011 |
| Abstract : The kinetics of the La3+-catalyzed methanolysis of a series of S-aryl methylphosphonothioates (4a-e, phenyl substituents = 3,5-dichloro, 4-chloro, 4-fluoro, 4-H, 4-methoxy) were studied at 25 degreesC with s(s)pH control. The reaction involves saturation binding of the anionic substrates to dimeric La3+/methoxide catalysts formulated as La2(3+)(-OCH3)x, where x = 2-5 depending on the solution s(s)pH. Cleavage of the La3+-bound methylphosphonothioates is fast, ranging from 5 x 10(-3) s(-1) to 5.5 x 10-(5) s(-1) for substrates 4a-e at a s(s)pH of 8.4 and 1.6 x 10(-1) s(-1) to 4 x 10(-3) s(-1) at a s(s)pH of 11.7. The rate accelerations for the methanolysis of substrates 4a-e, relative to their background methoxide-promoted reactions, average 7 x 10(10) and 1.5 x 10(9), respectively, at s(s)pH's of 8.4 and 11.7. The catalytic system is predicted to cleave EA 2192 (S-2(N,N-di-iso-propylaminoethyl)methylphosphonothioate), a toxic byproduct of the hydrolysis of VX, with a t1/2 between 4 and 8 min at a s(s)pH of 8.4, and 27 min at a s(s)pH of 11.7. |
| ESTHER : Dhar_2011_Inorg.Chem_50_3071 |
| PubMedSearch : Dhar_2011_Inorg.Chem_50_3071 |
| PubMedID: 21388185 |
Dhar BB, Edwards DR, Brown RS (2011)
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
Inorg Chem
50 :3071
Dhar BB, Edwards DR, Brown RS (2011)
Inorg Chem
50 :3071