OXIDATION OF ETHYLENEDIAMINE TETRAACETIC ACID BY AROMATIC N-BROMAMINES IN ALKALINE-MEDIUM WITH OSO4 AS CATALYST - A KINETIC AND MECHANISTICSTUDY

Kinetics of oxidation of disodium ethylenediamine-tetraacetic acid (ED TA) by bromamine-B (BAB) and bromamine-T (BAT) have been investigated at 35-degrees-C in alkaline medium with OsO4 as catalyst. The oxidatio n behaviour is similar in both cases and obeys the rate law, rate = k[ OX][OH-][EDTA]0[RNH2]-2 where x is a fraction, indicating retardation of rate by the reaction products,benzene sulphonamide (BSA) and p-tolu ene sulphonamide (PTS). The rate is unaffected by added halide ions an d variation in ionic strength. Activation parameters for the reaction have been computed from the Arrhenius plots and are compared with thos e of uncatalysed reaction. The mechanism assumes the formation of a co mplex between the active oxidant species, NaOBr, and the catalyst whic h interacts with the substrate in a fast step.