Reactions of metal ions with β-ketoamides
Abstract
The kinetics and mechanisms of the reactions of copper(II), iron (III) and dioxouranium(VI) with acetoacetamide have been investigated in aqueous solution at 25 °C and ionic strength 0.5 mol dm–3 NaClO4 using stopped-flow spectrophotometry. Mechanisms have been proposed which account satisfactorily for the kinetic data. Unlike β-diketones where in many instances the metal ion reacts exclusively with the enol tautomer, co-ordination of the amide tautomer of acetoacetamide is favoured by increased basicity of the carbonyl oxygen as a consequence of amide resonance.
Cu2+ and Fe3+ and Fe(OH)2+ react with the keto tautomer of acetoacetamide with rate constants of 10.0, 14.1 and 50 dm3 mol–1 s–1 respectively.