Neptunium(IV) fluoride

Neptunium(IV) fluoride or neptunium tetrafluoride is a inorganic compound with the formula NpF₄. It is a green salt and is isostructural with UF₄.

Synthesis

Alternative view of the structure of solid NpF₄.

Neptunium(IV) fluoride can be prepared by reacting neptunium(III) fluoride or neptunium dioxide with a gas mixture of oxygen and hydrogen fluoride at 500 °C:

$\mathrm{4}\mathrm{N}\mathrm{p}{\mathrm{F}}_{\mathrm{3}}\mathrm{+}{\mathrm{O}}_{\mathrm{2}}\mathrm{+}\mathrm{4}\mathrm{H}\mathrm{F}\mathrm{⟶}\mathrm{4}\mathrm{N}\mathrm{p}{\mathrm{F}}_{\mathrm{4}}\mathrm{+}\mathrm{2}{\mathrm{H}}_{\mathrm{2}}\mathrm{O}$

It can also be prepared by treating neptunium dioxide with HF gas:

$\mathrm{N}\mathrm{p}{\mathrm{O}}_{\mathrm{2}}\mathrm{+}\mathrm{4}\mathrm{H}\mathrm{F}\mathrm{⟶}\mathrm{N}\mathrm{p}{\mathrm{F}}_{\mathrm{4}}\mathrm{+}\mathrm{2}{\mathrm{H}}_{\mathrm{2}}\mathrm{O}$