Département de chimie moléculaire

Mixed uranyl aqua fluoro complexes [UO2(H2O)xFy]2-y (y = 1-4; x + y = 4, 5) have been optimized with BLYP and B3LYP d. functionals in vacuo and in a polarizable continuum modeling bulk water, and have been studied at the BLYP level with Car-Parrinello mol. dynamics (MD) simulations. Using constrained MD simulations and thermodn. integration, the computed free binding energy between aq. uranyl and fluoride, affording [UO2(H2O)4F]+, is in excellent agreement with expt. With the same technique, five-coordinate [UO2F4(H2O)]2- is indicated to be unstable against loss of the water ligand, as the free energy for dissocn. is computed to be ca. -7 kcal/mol in aq. soln. [on SciFinder(R)]