Mechanism of water exchange in aqueous uranyl(VI) ion. A density functional molecular dynamics study.
Constrained Car-Parrinello molecular dynamics simulations and thermodynamic integration have been performed for an associative pathway of water exchange between aqueous [UO2(OH2)5]2+ and bulk water. The simulated free energy of activation for this process, 6.7 kcal mol(-1), is significantly lower than that computed for a purely dissociative mechanism, 10.8 kcal mol(-1). Because the transient hexahydrate is indicated to have no chemically significant lifetime, the exchange mechanism can be classified as associative interchange.
Bühl
Michael
M
Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany. buehl@ mpi-muelheim.mpg.de
Kabrede
Hendrik
H