Gas-phase vertical ionization potentials for 27 molecules have been corrected to account for the effects of solvation. Values thus modified do not correlate well with rate constants, k(r)(a-X), for the solution-phase O-2-(a(1)Delta(g))-O-2(X(3)Sigma(g)(-)) radiative transition. The data are, therefore, not in accord with a proposed model in which charge-transfer interactions are said to be a principal factor in the effect of the solvent on the O-2(a(1)Delta(g))-O-2-(X(3)Sigma(g)(-)) transition probability. The trend in plots of k(r)(a-X) against the ionization potential (IP) is shown, rather, to reflect a transitive effect, deriving from,relationships between (1) k(r)(a-X) and the solvent refractive index, n, and (2) n and IF. Using data recorded in 56 solvents, k(r)(a-X)/n(2) is shown to depend linearly on n or functions of n, such as the solvent optical polarizability.