Kinetics and mechanism of the oxidation of oxyacids of phosphorus by butyltriphenylphosphonium dichromate

Butyltriphenylphosphonium dichromate (BTPPD), in dimethylsulphoxide, oxidizes lower oxyacids of phosphorus to oxyacids containing phosphorus in a higher oxidation state. The reaction is first order with respect to BTPPD. The Michaelis-Menten type kinetics was observed with respect to the oxyacids. The oxidation of deuteriated phosphinic and phosphorus acids indicated the presence of a substantial primary kinetic isotope effect. The reaction rate increases linearly with an increase in hydrogen-ion concentration. The reaction was studied in nineteen organic solvents. The solvent effect was analyzed using multiparametric equations. Suitable mechanism has been proposed.