Tabun hydrolysis products

Ultimately, depending on conditions (pH, reaction times, and so forth), tabun hydrolysis products may include cyanide ion hydrocyanic acid, the monoethyl ester of dimethylphosphor-amidic acid, ethanol, dimethylamine, and phosphoric acid. Under acidic conditions the P-N bond is cleaved early, whereas under aUcaline conditions the P-C bond cleaves much more readily than does P-N. Tabun has a half-life of about 7 h at pH 4—5, but this increases to about 8.5 h at pH 7. Tabun hydrolysis is less than 5% complete after 20 h at pH 8.5. 

The ester group is then hydrolysed, and the hydrolysis normally stops at the MePO(OH)2 stage. More vigorous conditions are required to rupture the Me—P bond. Thus the normal hydrolysis product of D.F.P. and of tabun, namely, phosphoric acid, will give a positive test with ammonium molybdate, whereas the product from sarin, namely, methylphosphonic acid, will not respond to this test. Vigorous reagents such as hot nitric acid and ammonium persulphate will break the C—P link and then a positive test for phosphate is obtained with ammonium molybdate. Sarin can be prepared in a variety of ways. Three... 

H20, and multiple adduct ions using ESI. 0-Ethyl (V,(V-dimethylphosphoramidic acid, the hydrolysis product of tabun, gave an abundant MH+ plus polymeric ions (28). 

The reaction of sarin with hydrogen chloride has been reported and kinetics determined by NMR imaging (Bard et al., 1970). With rate constants determined at 25°C, 81.5°C, and 100°C, Arrhenius analysis led to a calculated activation energy of 17.8 kcal/mole. The base-induced hydrolysis of sarin analogs and tabun was studied by Larsson (1958b) and the half-life of GA has been estimated to be 1.5 min at pH = 11 at 25°C. Ultimately, and depending on conditions (pH, reaction times, and so forth), hydrolysis products may include fluoride ion (or hydrogen fluoride), the 1-methylethyl ester of methylphosphonic acid, methylphosphonic acid, and 2-propanol. 

This material is a precursor for some G-series, GV-series, and V-series nerve agents and is also commonly found as a decomposition product/impurity resulting from hydrolysis of Tabun (C01-A001). 

This material is commonly found as a degradation product from hydrolysis of Tabun (C01-A001). 

Tabun has a good solubility in water. The hydrolysis rate is dependent on the pH value and also the temperature, but is always rapid. The products are phosphoric acid and hydrogen cyanide. The half-life for tabun in sea water at a temperature of 7oC is approximately 5 hours. It is important to note that there will always be a difference in the half-life for phosphor organic agents in fresh water compared to sea water. 

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