jp710093w_si_002.pdf (159.93 kB)
Density Functional Theory Study of Uranium(VI) Aquo Chloro Complexes in Aqueous Solution
journal contribution
posted on 2008-03-20, 00:00 authored by Michael Bühl, Nicolas Sieffert, Volodymyr Golubnychiy, Georges WipffMixed uranyl aquo chloro complexes of the type [UO2(H2O)xCly]2-y (y = 1, 2, 3, 4; x + y = 4, 5) have been
optimized at the BLYP, BP86, and B3LYP levels of density functional theory in vacuo and in a polarizable
continuum modeling bulk water (PCM) and have been studied at the BLYP level with Car−Parrinello molecular
dynamics (MD) simulations in the gas phase and in explicit aqueous solution. Free binding energies were
evaluated from static PCM data and from pointwise thermodynamic integration involving constrained MD
simulations in water. The computations reveal significant solvent effects on geometric and energetic parameters.
Based on the comparison of PCM-optimized or MD-averaged uranyl−ligand bond distances with EXAFS-derived values, the transition between five- and four-coordination about uranyl is indicated to occur at a Cl
content of y = 2 or 3.