Neptunium(IV) fluoride
IUPAC name
Neptunium(IV) fluoride
Other names
Neptunium tetrafluoride
3D model (JSmol)
  • InChI=1S/4FH.Np/h4*1H;/q;;;;+4/p-4
  • F[Np](F)(F)F
Molar mass 313 g/mol
Appearance Green solid[1]
Monoclinic, mS60[1]
C2/c, No. 15[2]
a = 1.27 nm, b = 1.0082 nm, c = 0.833 nm
α = 90°, β = 126.03°, γ = 90°
0.86256 nm3
116 ± 4 J/mol·K[1]
148 ± 3 J/mol·K[1]
−1874 ± 16 kJ/mol[1]
-1783 ± 16 kJ/mol[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Neptunium(IV) fluoride or neptunium tetrafluoride is a inorganic compound with the formula NpF4. It is a green salt and is isostructural with UF4.[3]


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:[1]

It can also be prepared by treating neptunium dioxide with HF gas:[1]


  1. ^ a b c d e f g h Haire, Richard G. (2006). "Neptunium". In Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. pp. 730–736. doi:10.1007/1-4020-3598-5_9. ISBN 1-4020-3555-1.
  2. ^ Zachariasen, W. H. (1949). "Crystal chemical studies of the 5f-series of elements. XII. New compounds representing known structure types". Acta Crystallographica. 2 (6): 388–390. doi:10.1107/S0365110X49001016.
  3. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.