| Abstract
| - The hydrates of Cu+, Ag+, CuS-, AgS-, Cu2S, andAg2S were investigated with density functional theory(DFT), solvent field, and atoms-in-molecules (QTAIM) calculations. We found that covalent bonding of thefirst-shell water molecules to the metals plays a significant role in the total solvation energy. Moleculargraphs were obtained and the bonding characterized by analysis of the electron density and its laplacian atbond critical points. Long-range electrostatic interactions between solute and the bulk solvent, quantified bysolvent-field calculations, are more important for hydrated anions CuS- and AgS- than for Cu+ and Ag+ aswell as for the neutral species Cu2S and Ag2S. Computed enthalpies of formation for hydrated Cu+ and Ag+correlated well with experimentally determined values and allowed us to characterize the structures of severalhydrates studied in the gas phase. We found that the stability of the hydrates is leveled in the water solventfield. The reactions of dissociation and substitution of metal sulfides in the gas phase and in solution werecompared. A decrease in the of energy of the reactions in going from the gas phase to solution is explainedon the basis of the higher coordination of metal atoms in the first hydration shell.
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