5 research outputs found
Assessment of an effective quasirelativistic methodology designed to study astatine chemistry in aqueous solution
International audienceA 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
Questioning the Affinity of Electrophilic Astatine for Sulfur-containing Compounds: Unexpected Bindings Revealed
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