A stopped-flow study on the kinetics and mechanism of CO2 uptake by chromium(III) complexes with histamine and pyridoxamine

Abstract

The mechanism and kinetics of the reaction between an aqueous solution of CO2 and coordinate ions, cis-[Cr(C2O4)(L–L)(OH2)2]+, where L–L denotes histamine (hm) or pyridoxamine (pm), were investigated using the stopped-flow technique. The studies were carried out at 5 to 25 °C over the pH range 6.04–8.15 at a fixed ionic strength solution (1 M NaClO4). The results enabled determination of the number of steps of the reactions studied. Based on the kinetic equations, rate constants were determined for each step. Finally, thermodynamic activation parameter values ΔH‡, were calculated for the reaction studied from temperature relationships.