[N(<i>n</i>‑Bu)₄]₂[Pu(NO₃)₆] and [N(<i>n</i>‑Bu)₄]₂[PuCl₆]: Starting Materials To Facilitate Nonaqueous Plutonium(IV) Chemistry

The reaction of plutonium­(IV) in aqueous nitric acid with tetra-<i>n</i>-butylammonium nitrate leads to the immediate precipitation of [N­(<i>n</i>-Bu)₄]₂[Pu­(NO₃)₆] (<b>1</b>) in high yield. The analogous reaction in HCl with tetra-<i>n</i>-butylammonium chloride gives [N­(<i>n</i>-Bu)₄]₂[PuCl₆] (<b>2</b>). Both <b>1</b> and <b>2</b> are soluble in a range of organic solvents and have been characterized by single-crystal X-ray diffraction, IR spectroscopy, and solid- and solution-phase vis–near-IR spectroscopy. <b>1</b> and <b>2</b> provide facile synthetic entry routes to study plutonium­(IV) ligand complexation reactions in organic solvent media under both air/moisture-stable and -sensitive conditions