Reactivity of hydroxamic acids in nitric acid solutions

Full text of publication follows. Hydroxamic acids are salt free organic compounds with the general formula RC(=O)NHOH. They are weaker acids than carboxylic acids RC(=O)OH, which are structurally related. They are di-oxygen chelate ligands, and can form stable metal complexes with five-membered chelate rings with hard cations. Reactivity of hydroxamic acids upon reduction and co-ordination of actinides has been investigated using a range of experimental techniques (stop-flow/UV-Vis, spectroscopy, extraction) and chemical speciation modelling. Decomposition and acidic hydrolysis were studied as well. From the experimental kinetic and solvent extraction distribution data, the effect of hydroxamic acids on speciation and mass transfer of uranium and transuranic elements in model process solutions has been evaluated. (authors)