Stabilization calculation of the energy and lifetime of metastable SO_4~(2-)

摘要

It is known that SO_4~(2-) is not electronically stable as an isolated species but can be rendered stable by solvation (e.g., by adding a few H_2O molecules). Recently, our group introduced a Coulomb repulsion model that offers an approximation to the energy instability and lifetimes of such species. In order to achieve an independent and likely more reliable estimate of the instability of SO_4~(2-), we have undertaken a follow-up study of this dianion. Specifically, we apply a stabilization method to determine the vertical electronic energy difference between the metastable SO_4~(2-)dianion and its SO_4~(-1) daughter at several levels of theory. The particular variant of the stabilization method used here involves adding a partial positive charge to the central sulfur nucleus in order to confine the escaping electron. Our coupled-cluster data, which represent our highest level of theory, suggest that SO_4~(2-) is unstable by 1.1 eV and has a lifetime with respect to electron loss of 1.6 X 10~(-10) s(our earlier estimates were 0.75 eV and 2.7 X 10~(-8) s).