Collect. Czech. Chem. Commun. 2003, 68, 2377-2385

On the Stability of Hydroxo-Dilead(II) Complex Cations

Martin Breza* and Stanislav Biskupič

Department of Physical Chemistry, Slovak Technical University, SK-812 37 Bratislava, Slovakia


Using Hartree-Fock, B3LYP and MP2 treatments, the optimal geometries and corresponding electronic structures of various isomers of [Pb2(OH)n]q complex cations with total charges q = 4 - n, n = 1, 2, 3, are investigated. [Pb(μ-OH)Pb]3+ seems to be the most stable whereas [Pb(μ-OH)Pb(OH)]2+ and [Pb(μ-OH)Pb(OH)2]+ are unstable (because additional non-bridging hydroxyl weakens the neighboring Pb-Oμ and Oμ-Hμ bonds). Direct Pb-Pb and Oμ-Oμ interactions are weakly antibonding in all the systems under study. The clusters are held together exclusively by relatively weak Pb-O bonds. Non-measurable concentrations of [Pb(μ-OH)Pb]3+ in aqueous solutions might be explained by its reaction with OH- yielding preferably unstable [Pb(μ-OH)Pb(OH)]2+ species.

Keywords: Lead(II) clusters; Hydroxo complexes; Molecular structure; Geometry optimization; Ab initio calculations; HF; DFT.

References: 22 live references.