In liquid/liquid extraction fuel cycle scenarios, successful metal partitioning depends upon maintaining predictable ligand concentrations and metal valence states in a non-equilibrium system perturbed by the constant input of energy. Energetic particles from nuclide decay interact with solution to yield ions and radicals that react with solutes. These reactions have the potential to interfere with the expected separations chemistry. This paper describes example reactions of the main transient products of aqueous and organic diluents with ligands or metal ions. These reactions tend to decrease ligand concentrations, generate unwanted products, and change metal valence states. It discusses the effects of these reactions on the desired separations, using examples mainly from work conducted at the Idaho National Laboratory Center for Radiation Chemistry Research (CR2).