Neptunium(V) fluoride
Neptunium(V) fluoride is an inorganic chemical compound with the formula NpF5. It is a solid actinide pentahalide. It is one of the binary compounds of neptunium and fluorine, the other being neptunium(VI) fluoride (NpF6) and neptunium(IV) fluoride (NpF4).
NpF5 is a reddish-brown solid under normal conditions. It is hygroscopic, meaning it readily absorbs moisture from the air. The structure in the solid state consists of polymeric chains where neptunium is octahedrally coordinated to six fluorine atoms, with bridging fluorine atoms linking the neptunium centers.
NpF5 can be synthesized by reacting neptunium(VI) fluoride with iodine or by heating neptunium(IV) fluoride with fluorine gas under pressure. The reaction with iodine reduces the oxidation state of neptunium from +6 to +5.
Neptunium(V) fluoride is a strong fluorinating agent and is used in chemical reactions to introduce fluorine atoms into other compounds. It is also of interest in nuclear chemistry due to neptunium's role in nuclear fuel cycles. Handling NpF5 requires specialized equipment and procedures due to its radioactivity and reactivity. It is corrosive and toxic. Detailed data on its physical and chemical properties are limited due to its radioactivity and the difficulties in handling such compounds.