Computational Study of the Mono- and Dianions of SO2, SO3, SO4, S2O3, S2O4, S2O6, and S2O8
journal contributionposted on 29.02.1996, 00:00 by Michael L. McKee
DFT theory (B3LYP/6-311+G(2d)//B3LYP/6-31+G(d)) has been used to characterize sulfoxy anions and dianions as large as S2O82-, while post-HF theory ([QCISD(T)/6-31+G(2df)]//MP2/6-31+G(d)) has been used for systems as large as S2O32-. Adiabatic and vertical ionization potentials have been computed to assess the gas-phase stability of the dianions. Three dianions (S2O62-, S2O82-, and SO42-·4H2O) are predicted to have positive vertical ionization energies. S2O62- is predicted to have a negative (exothermic) adiabatic ionization potential; however, a large predicted geometry change between the dianion and monoanion rationalizes the measurable experimental lifetime of the dianion in the gas phase. Isotropic hyperfine coupling constants for 33S have been calculated for the sulfoxy monoanions and compared with experiment.