Estimation of the pKa values of water ligands in transition metal complexes using density functional theory with polarized continuum model solvent corrections.

The deprotonation energies of the water ligands in a set of 40 d-block metal complexes have been calculated using density functional theory with polarized continuum model solvent corrections. The complexes include 13 aqua ions [M(OH(2))(n)](2+/3+) and a variety of aqua complexes with organic co-ligands, whose experimental pK(a) values have been reported in the literature. For comparison, the deprotonation energies of a set of 60 organic and inorganic molecules with experimental pK(a) values ranging from -25 (HSbF(6)) to +52 (C(2)H(6)) have also been calculated.