Oxidation Of Alihatic Primary Amines By Bromamine-B In Hydrochloric Acid Medium In The Presence of Ruthenium(III) Catalyst. A Kinetic And Mechanistic Study

摘要

The kinetics of ruthenium(III) catalyzed oxidation of aliphatic primary amines n-propylamine(nPA), n-butylamine (nBA) and n-hexylamine (nHA), by sodium N-bromobenzene sulphonamide or bromamine-B (BAB) in HCl medium has been studied in the temperataure range 298-313 K. The reaction rate shows a first order dependence each on BAB, amino and ruthenium(III). The reaction also shows an inverse fractional order dependence on acid concentration. Added halide ions and reaction product of BAB benzenesulphonamide and variation of ionic strength of the solvent medium have no effect on the rate: The activation parameters have been evaluated. Mechanisms consistent with the kinetic data have been propsoed. The protonation constant of monobromamine-B has been evaluated to be 24(+-)1. A Taft LFE relationship is observed for the ruthenium(III) catalyzed reaction with #rho#~*=-6.62 indicating that the electron donating groups enhance the reaction rate. An isokinetic relationship is observed with #beta# = 382 K indicating that enthalpy factors control the rate.