An Ab Initio Investigation of the Hydration of Thallium(III) and Mercury(II)

An Ab Initio Investigation of the Hydration of Lead(II)

“…To our surprise, the structure was actually stable at some levels of theory (see Table 1), indicating that the hemidirected and holodirected structures for hexaaqualead(II) could be interchanged by inclusion of a second hydration sphere. In accordance with earlier calculations [2], the effect of the second hydration sphere is to shorten slightly the Pb-O distance and raise the symmetric stretching vibrational frequency by 20-30 cm −1 .…”

“…The enneaaqualead(II) structure can exist in one of two C 3 forms, the intermittently stable [9 + 0] and the more stable [6 + 3]. The octadecaaqualead(II) structure [6 + 12] was also examined, and in accordance with previous results the structure with symmetry T was chosen [2]. To our surprise, the structure was actually stable at some levels of theory (see Table 1), indicating that the hemidirected and holodirected structures for hexaaqualead(II) could be interchanged by inclusion of a second hydration sphere.…”

An Ab Initio Investigation of the Hydration of Antimony(III)

“…In many cases to follow, the symmetry of the minimum energy complexes was the same as those previously found for bismuth [26]. To confirm these results, starting with high symmetry structures, systematic desymmetrization along the various irreducible representations was carried out [27,28]. We did not employ an implicit solvation model for reasons described previously [3].…”

“…We also extended this work to lead(II), with valence electron configuration 6s 2 5d 10 [3]. The presence of an ns 2 subshell can give rise to either hemidirected structures (which tend to be favored at lower coordination numbers) with ligands that are not symmetrically distributed around the central ion, or holodirected structures with a symmetrical distribution. No consensus exists on the coordination number of lead(II), with predictions ranging from 4 to 9, but our results were most consistent with a hemidirected hexaaqualead(II) species.…”