Hydrolysis, solvation, and reduction of SO3, S2O6, ClO3(OH), Cl2O7, and ArO4-relating chemical properties to the instability of S=O, Cl=O, and Ar=O groups
Artikel i vetenskaplig tidskrift, 2002

Successive water addition to the mononuclear species SO3(g) and ClO3(OH)(g) and ArO4(g), as well as the binuclear clusters S2O6(g) and Cl2O7(g), is Studied by means of quantum chemistry. A large basis set effect is observed for the S-O, Cl-O, and Ar-O bond distances, as well as for redox energetics. While the 6-311+G(d,p) basis set is enough for O and H atoms, S, Cl, and Ar require the 6-311 +G(3df) set for an accurate description. Given this combination of basis sets, B3LYP is found to give very good results of equal quality to high-level methods. The dominating chemical feature that is monitored is the instability of the S=O, Cl=O, and Ar=O bonds. This instability causes the acidity displayed by water solutions of SO2(OH)(2) and ClO3(OH) and makes the Cl and Ar systems prone to O-2(g) evolution. The latter system is also reduced directly by water, while the reduction of SO2(OH)(2) to H2S requires a reducing agent of equivalent power to H,. Three water ligands are necessary to produce nanoscale deprotonation f SO2(OH)(2) and ClO3(OH). The hydrolytic cleavage of the S-O-S and Cl-O-Cl bridges is exothermic by 23-30 kJ/mol, which explains the sensitivity to excess of water displayed by these polymers.

HClO4

X=O bond

hydrolysis

ArO4

redox

S2O6

SO3

Cl2O7

Författare

J.R.T Johnson

Itai Panas

Chalmers, Institutionen för oorganisk miljökemi

Journal of Physical Chemistry A

1089-5639 (ISSN) 1520-5215 (eISSN)

Vol. 106 184-199

Ämneskategorier

Atom- och molekylfysik och optik

Teoretisk kemi