Acetohydroxamatoiron (III) complexes Andrieux et al. ACETOHYDROXAMATOIRON (III) COMPLEXES: THERMODYNAMICS OF FORMATION AND TEMPERATURE DEPENDENT SPECIATION

1 Acetohydroxamatoiron (III) complexes Andrieux et al. Abstract Studies of the thermodynamics of formation of the acetohydroxamatoiron(III) complexes were carried out in acidic media at temperatures ranging from 293 to 323 K. Through the isolation of the unique UV –visible spectra of all three complexes, it was possible to determine their formation constants and deduce enthalpies and entropies of formation as well as their molar absorptivities. The enthalpies of formation of the mono-, bis-and trisacetohydroxamatoiron(III) complexes were found to be –56.4, –17.09 and +19.74 kJ • mol-1 , respectively. Following the determination of the enthalpy and entropy of formation of these complexes, speciation diagrams were calculated for the complexes at temperatures ranging from 293 to 323 K. 2 Acetohydroxamatoiron (III) complexes Andrieux et al.