Phenyliodoso Acetate Oxidation of Cobalt(III) Bound and Unbound α-Amino Acids

Abstract

The kinetics of phenyliodoso acetate (PIA) oxidation of cobalt(III) bound and unbound α-amino acids have been studied in aq. acetic acid in the presence of 1.00 M HClO₄ at 50ºC. The reaction exhibits total second order kinetics, first order in each reactant. The rate of PIA oxidation is
susceptible to polar influences. The introduction of substituents at the α-carbon
atom in amino acids increase rate marginally while introduction of
substituents at the amino nitrogen retard the rate considerably evidencing
an initial attack by PIA at amino nitrogen. The formation of glyoxylatopentaamrninecobalt(
III) complex during the PIA oxidation of glycinatopentaamrninecobalt(
III) complex suggests cleavage of N—H and C—H
bonds.