title: Advances on the Determination of the Astatine Pourbaix Diagram: Predomination of AtO(OH)2 (-) over At(-) in Basic Conditions.
abstract: It is generally assumed that astatide (At(-) ) is the predominant astatine species in basic aqueous media. This assumption is questioned in non-complexing and non-reductive aqueous solutions by means of high-pressure anion-exchange chromatography. Contrary to what is usually believed, astatide is found to be a minor species at pH=11. A different species, which also bears a single negative charge, becomes predominant when the pH is increased beyond 7. Using competition experiments, an equilibrium constant value of 10(-6.9) has been determined for the formation of this species from AtO(OH) with the exchange of one proton. The identification of this species, AtO(OH)2 (-) , is achieved through relativistic quantum mechanical calculations, which rule out the significant formation of the AtO2 (-) species, while leading to a hydrolysis constant of AtO(OH) in excellent agreement with experiment when the AtO(OH)2 (-) species is considered. Beyond the completion of the Pourbaix diagram of astatine, this new information is of interest for the development of (211) At radiolabeling protocols.
authors.affiliation: SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université de Nantes, 4 rue Alfred Kastler, BP 20722, 44307, Nantes Cedex 3, France.|CEISAM, UMR CNRS 6230, Université de Nantes, 2 rue de la Houssinière, BP 92208, 44322, Nantes Cedex 3, France.
authors.forename: Dumitru-Claudiu
authors.initials: DC
authors.lastname: Sergentu
authors.affiliation: SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université de Nantes, 4 rue Alfred Kastler, BP 20722, 44307, Nantes Cedex 3, France.|CEISAM, UMR CNRS 6230, Université de Nantes, 2 rue de la Houssinière, BP 92208, 44322, Nantes Cedex 3, France.
authors.forename: David
authors.initials: D
authors.lastname: Teze
authors.affiliation: SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université de Nantes, 4 rue Alfred Kastler, BP 20722, 44307, Nantes Cedex 3, France.
authors.forename: Andréa
authors.initials: A
authors.lastname: Sabatié-Gogova
authors.affiliation: GIP ARRONAUX, 1 rue Aronnax, CS 10112, 44817, Saint-Herblain Cedex, France.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Alliot
authors.affiliation: SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université de Nantes, 4 rue Alfred Kastler, BP 20722, 44307, Nantes Cedex 3, France.
authors.forename: Ning
authors.initials: N
authors.lastname: Guo
authors.affiliation: CEISAM, UMR CNRS 6230, Université de Nantes, 2 rue de la Houssinière, BP 92208, 44322, Nantes Cedex 3, France.
authors.forename: Fadel
authors.initials: F
authors.lastname: Bassal
authors.affiliation: CEMHTI, UPR CNRS 3079, Site Cyclotron CS30058, 3 A rue de la Férolerie, 45071, Orléans Cedex 2, France.
authors.forename: Isidro Da
authors.initials: ID
authors.lastname: Silva
authors.affiliation: CEISAM, UMR CNRS 6230, Université de Nantes, 2 rue de la Houssinière, BP 92208, 44322, Nantes Cedex 3, France.
authors.forename: David
authors.initials: D
authors.lastname: Deniaud
authors.affiliation: SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université de Nantes, 4 rue Alfred Kastler, BP 20722, 44307, Nantes Cedex 3, France.
authors.forename: Rémi
authors.initials: R
authors.lastname: Maurice
authors.affiliation: SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université de Nantes, 4 rue Alfred Kastler, BP 20722, 44307, Nantes Cedex 3, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Champion
authors.affiliation: CEISAM, UMR CNRS 6230, Université de Nantes, 2 rue de la Houssinière, BP 92208, 44322, Nantes Cedex 3, France. nicolas.galland@univ-nantes.fr.
authors.forename: Nicolas
authors.identifier: http://orcid.org/0000-0001-5618-226X
authors.initials: N
authors.lastname: Galland
authors.affiliation: SUBATECH, UMR CNRS 6457, IN2P3/EMN Nantes/Université de Nantes, 4 rue Alfred Kastler, BP 20722, 44307, Nantes Cedex 3, France. gilles.montavon@subatech.in2p3.fr.
authors.forename: Gilles
authors.initials: G
authors.lastname: Montavon
keywords: Pourbaix diagrams; astatine; competition experiments; hydrolysis constants; quantum mechanical calculations