Neptunium nitrates

Abstract

Hydrated neptunium-(IV),-(V), and-(VI) nitrates, Np(NO₃)₄,2H₂O (grey), NpO₂NO₃,H₂O (green), NpO(NO₃)₃,3H₂O (pink), and NpO₂(NO₃)₂,6H₂O (pink), have been prepared from aqueous nitric acid. Solvated neptunium-(IV) and -(VI) nitrates, Np(NO₃)₄,xN₂O₅(x∼ 1·2)(off-white) and NpO₂(NO₃)₂,N₂O₅,H₂O (pale pink), have been prepared by reaction of neptunium tetrachloride and neptunium trioxide hydrate, respectively, with dinitrogen pentoxide. The neptunium tetranitrate dimethylacetamide (DMA) complex, Np(NO₃)₄,2·5DMA (grey-green), has been prepared by reaction of the dihydrate with the ligand, or from the corresponding chloride complex and silver nitrate in methyl cyanide. The attempted preparation of neptunium(V) nitrato- and oxynitrato-complexes was unsuccessful. Magnetic properties, infrared spectra, and some X-ray diffraction measurements are also presented.