Kinetics and mechanism of oxidation of n-propanolamine by dihydroxydiperiodatonickelate (IV) in alkaline medium

Abstract

The kinetics of oxidation of n-Propanolamine (n—PA) by dihydroxy diperiodato-nickelate(IV) (DPN) in alkaline medium was studied with spectrophotometry in a temperature range of 293.2-308.2 K. The reaction was found to be pseudo first-order with respect to DPN and fractional order to n—PA. The rate constant $k_{obs}$, rose with an increase in the concentration of $OH^-$ and a decrease in the concentration of $IO_4^-$. Added salts did not affect the rate and no free radical was detected. From the evaluation of linear data, a reaction mechanism is proposed which involves a pre-equilibrium of an adduct formation between n—PA and dihydroxymonoperiodatonickelate(IV) (MPN), and the activation parameters of the rate-determining step have been calculated.