6. Organic complexes

Actinides interact with organic compounds, particularly those with oxygenated complexing functions. As in the case of inorganic complexes, the formation of chemical bonds between the actinide or actinyl ion and carboxylate functions displaces molecules of water of hydration. This therefore induces several contributions to the free enthalpy of reaction Δ _r G ⁰ = Δ _r H ⁰ - TΔ _r S ⁰ ; often, complexation with single ligands is favored by entropic gain due to dehydration of the actinide or actinyl ion, whereas it has an enthalpic cost. When ligands have a chelate effect, i.e. complex ions with different chemical functions,...