Theoretical model of copper Cu(I)/Cu(II) hydration.: DFT and ab initio quantum chemical study

Hydration study of both Cu+ and Cu2+ cations in variable water environment was performed using the DFT method. After optimization using B3PW91 functional, stabilization energies with and without ligand repulsion were calculated using B3LYP functional. It was found that optimal Cu+ coordination involves two directly bonded solvent molecules while Cu2+ cation prefers 4 (or 5) coordinated waters in the first solvation shell. Higher coordination corresponds to lower stabilization energies. Morokuma's energy decomposition (for Cu+ complexes only) was used to elucidate bonding characteristics in detail. NBO partial charges and MO's analyses support the explanation for these energy results. (C) 2004 Elsevier B.V. All rights reserved.