Abstract
The coordination of neutral ligands (L = O__C, HC__N, __N__H~3~, P__H~3~, S__H~2~, HNC__O and H~2~O) to Pb^2+^ is investigated and analyzed by means of the topological analysis of the Electronic Localization Function (ELF). It is shown that the mean charge density of the V(Pb) basin (〈ρ〉~V(Pb)~) can reach a ligand‐independent limiting value from n = 6, a coordination number from which the [PbL~n~]^2+^ complexes adopt holodirected structures. The investigations performed on anionic series (L = H__S^−^, __O__H^−^, __C__N^−^, F^−^, Cl^−^, and Br^−^) lead to optimized stable structures in which the coordination number does not exceed n = 4, even in the presence of a model aqueous solvent. This different behavior with respect to the neutral ligand series is interpreted by means of natural populations and electrostatic repulsions. The main result of this contribution is that stable Pb(II) complexes could be those exhibiting reasonable values of 〈ρ〉~V(Pb)~, namely those not exceeding the saturation plateau evidenced in the present piece of work. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010