title: On the stoichiometry and stability of americium(III) complexes with a hydrophilic SO3-Ph-BTP ligand, studied by liquid-liquid extraction.
abstract: 1:1 and 1:2 complexes of americium(III) with a hydrophilic anionic SO3-Ph-BTP4-ligand were detected in acidic aqueous nitrate solutions by a solvent extraction method. The determined conditional stability constants of these complexes, logβ1= 4.35 ± 0.07 and logβ2= 7.67 ± 0.06, related to 1 M aqueous solutions, are much lower than the literature values for the analogous curium species, determined by TRLFS in very dilute aqueous solutions. There is also no evidence for the existence of the 1:3 Am3+complex similar to the reported curium(III) complex. A hypothesis has been formulated to explain these discrepancies. It suggests the necessity to carefully check the equilibria in each phase of solvent extraction systems containing two competing ligands-lipophilic and hydrophilic.
authors.affiliation: Department - Centre for Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Steczek
authors.affiliation: Department - Centre for Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Rejnis
authors.affiliation: Department - Centre for Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Narbutt
authors.affiliation: Nuclear Energy Division, RadioChemistry & Processes Department, CEA Marcoule, 30207 Bagnols sur Cèze, France.
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Charbonnel
authors.affiliation: Nuclear Energy Division, RadioChemistry & Processes Department, CEA Marcoule, 30207 Bagnols sur Cèze, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Moisy
keywords: Americium(III); Complexes; Hydrophilic BTP ligand; Partitioning; Solvent extraction