MONO-COMPLEX FORMATION KINETICS OF 2-ACETYLCYCLOHEXANONATOCHROMIUM(III) IN AQUEOUS-SOLUTION

The kinetics and mechanism of the reaction of complexation of chromium(III) with 2-acetylcyclohexanone has been investigated spectrophotometrically in aqueous solution at 50-degrees-C and ionic strength 0.5 mol dm-3 NaClO4. The equilibrium constants of the complex have been determined. The mechanism proposed to account for the kinetic data involves a double reversible pathway where both Cr3+ and Cr(OH)2+ react with the enol tautomer of the ligand wit rate constants of 9.6 X 10(-3) dm3 mol-1 s-1, and 3.69 X 10(-2) dm3 mol-1 s-1, respectively. Some discussions are made on the basis of Eigen-Wilkins theory considering the effect of solvent exchange on the complex formation.