title: Assessment of an effective quasirelativistic methodology designed to study astatine chemistry in aqueous solution.
abstract: A cost-effective computational methodology designed to study astatine (At) chemistry in aqueous solution has been established. It is based on two-component spin-orbit density functional theory calculations and solvation calculations using the conductor-like polarizable continuum model in conjunction with specific astatine cavities. Theoretical calculations are confronted with experimental data measured for complexation reactions between metallic forms of astatine (At(+) and AtO(+)) and inorganic ligands (Cl(-), Br(-) and SCN(-)). For each reaction, both 1:1 and 1:2 complexes are evidenced. The experimental trends regarding the thermodynamic constants (K) can be reproduced qualitatively and quantitatively. The mean signed error on computed Log K values is -0.4, which corresponds to a mean signed error smaller than 1 kcal mol(-1) on free energies of reaction. Theoretical investigations show that the reactivity of cationic species of astatine is highly sensitive to spin-orbit coupling and solvent effects. At the moment, the presented computational methodology appears to be the only tool to gain an insight into astatine chemistry at a molecular level.
authors.affiliation: Laboratoire CEISAM, UMR CNRS 6230, Université de Nantes, 2 Rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Champion
authors.forename: Mahamadou
authors.initials: M
authors.lastname: Seydou
authors.forename: Andrea
authors.initials: A
authors.lastname: Sabatié-Gogova
authors.forename: Eric
authors.initials: E
authors.lastname: Renault
authors.forename: Gilles
authors.initials: G
authors.lastname: Montavon
authors.forename: Nicolas
authors.initials: N
authors.lastname: Galland