Volatile adducts of neptunyl. beta. -diketonates. Synthesis and properties

The authors have recently described the synthesis of volatile pivaloyltrifluoroacetonate derivatives of neptunium (neptunyl), NpO/sub 2/(PTFA)/sub 2/, based on adducts with neutral ligands of varying ligand strengths. Not all of the adducts were stable with respect to decomposition to give Np (PTFA)/sub 4/ during sublimation. Since the degree of decomposition was found to depend on the basicity of the neutral ligand, it would also be expected to depend on the basicity of the ..beta..-diketonate anion. Their main goal in the present paper was to investigate the range of ..beta..-diketonate and neutral ligands which are capable of forming volatile, yet thermally stable, complexes with the neptunyl ion. Ligands with a wide range of basicities were evaluated as part of this study.