KINETICS OF OXIDATION OF PHOSPHINIC, PHENYLPHOSPHINIC AND PHOSPHORUS-ACIDS BY ETHYL N-CHLOROCARBAMATE

The oxidation of phosphinic, phenylphosphinic and phosphorous acids by ethyl N-chlorocarbamate (ECC) in perchloric acid solution, results in the formation of corresponding phosphorous acids containing phosphorus in the higher oxidation state. The reaction is first order each in [ECC], and the oxyacid. Hydrogen ion dependence has the form: k(obs) = a + b[H+]. Oxidation of deuteriated phosphinic and phosphorous acids show the presence of a substantial primary kinetic isotope effect. The reaction does not induce polymerization of acrylonitrile. Added ethyl carbamate, one of the products of the oxidation reaction, has no effect on the reaction rate. Both ECC and ECCH+ have been postulated as the reactive oxidizing species. It has been shown that the inactive tautomer of the phosphorus oxyacids, RHP(O)OH, participates in the oxidation process. A rate-determining step involving transfer of a hydride ion from the P - H bond to the oxidant has been proposed.