title: First structural characterization of a protactinium(V) single oxo bond in aqueous media.
abstract: The present work describes the first structural studies of protactinium(V) in sulfuric and hydrofluoric acid media using X-ray absorption spectroscopy. The results show unambiguously the absence of the trans-dioxo bond that characterizes the other early actinide elements such as U and Np. In concentrated sulfuric acid (13 M), Pa(V) is proved to exhibit a single oxo bond as postulated in the literature for species in more dilute media. In a 0.5 M HF medium, XANES and EXAFS spectra indicate the absence of any oxo bond: Pa(V) exists in the form of a pure fluoro complex.
authors.affiliation: Centre National de la Recherche Scientifique/IN2P3/Paris XI, Institut de Physique Nucléaire, 91406 Orsay Cedex, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Le Naour
authors.forename: Didier
authors.initials: D
authors.lastname: Trubert
authors.forename: Maria V
authors.initials: MV
authors.lastname: Di Giandomenico
authors.forename: Clara
authors.initials: C
authors.lastname: Fillaux
authors.forename: Christophe
authors.initials: C
authors.lastname: Den Auwer
authors.forename: Philippe
authors.initials: P
authors.lastname: Moisy
authors.forename: Christoph
authors.initials: C
authors.lastname: Hennig