Neptunium(VII) oxide-hydroxide is a chemical compound which has neptunium in its highest oxidation state of +7. This compound reacts with basic salts such as potassium hydroxide to form neptunates (NpO53-) and water.[1]
NpO2(OH)3 + 3KOH → K3NpO5 + 3H2O
Neptunium(VII) oxide-hydroxide is stable in an alkaline solution, however, it is slowly reduced to Np(VI) in an acidic solution. In water, it forms a greenish solution.[1] This compound decomposes slowly to an oxidized solid.[2]
Production
Neptunium(VII) oxide-hydroxide is produced by the oxidation of Np(VI) in alkaline solution with ozone, then neutralized with nitric acid to precipitate out the neptunium(VII) oxide-hydroxide.
References
^ abV.I.Spitsyn; A.D.Gelman; N.N.Krot; M.P.Mefodiyeva; F.A.Zakharova; Yu.A.Komkov; V.P.ShilovI.; V.Smirnova (1968). "Heptavalent state of neptunium and plutonium". Journal of Inorganic and Nuclear Chemistry. 31 (9). Institute of Physical Chemistry of the Academy of Sciences of the USSR: 2733–2745. doi:10.1016/0022-1902(69)80187-9.
^Robert J. Lemire (2001). Lemire, Robert (ed.). Chemical Thermodynamics of Neptunium and Plutonium. Elsevier Science. p. 116. ISBN9780444503794.