Hafnium tetrafluoride

Hafnium tetrafluoride is the inorganic compound with the formula HfF₄. It is a white solid. It adopts the same structure as zirconium tetrafluoride, with 8-coordinate Hf(IV) centers.

Hafnium(IV) fluoride

Names
IUPAC names Hafnium(IV) fluoride Hafnium tetrafluoride
Identifiers
CAS Number	13709-52-9 Y
3D model (JSmol)	Interactive image
ChemSpider	3306631 Y
ECHA InfoCard	100.033.856
EC Number	237-258-0
PubChem CID	50925283
CompTox Dashboard (EPA)	DTXSID30929710
InChI InChI=1S/4FH.Hf/h4*1H;/q;;;;+4/p-4 Key: QHEDSQMUHIMDOL-UHFFFAOYSA-J
SMILES [F-].[F-].[F-].[F-].[Hf+4]
Properties
Chemical formula	HfF4
Appearance	white crystalline powder
Density	7.1 g/cm3[1]
Boiling point	970 °C (1,780 °F; 1,240 K) (sublimes)[1]
Structure
Crystal structure	Monoclinic, mS60[2]
Space group	C2/c, No. 15
Lattice constant	a = 1.17 nm, b = 0.986 nm, c = 0.764 nm
Hazards
Flash point	Non-flammable
Related compounds
Other anions	Hafnium(IV) chloride
Other cations	Titanium(IV) fluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Hafnium tetrafluoride forms a trihydrate, which has a polymeric structure consisting of octahedral Hf center, described as (μ−F)₂[HfF₂(H₂₀)₂]_n(H₂O)_n and one water of crystallization. In a rare case where the chemistry of Hf and Zr differ, the trihydrate of zirconium(IV) fluoride has a molecular structure (μ−F)₂[ZrF₃(H₂₀)₃]₂, without the lattice water.^[3]

References

1. Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, Florida: CRC Press. p. 4.66. ISBN 1-4398-5511-0.
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. p. 965. ISBN 978-0-08-037941-8.

Further reading

• Benjamin, S. L., Levason, W., Pugh, D., Reid, G., Zhang, W., "Preparation and structures of coordination complexes of the very hard Lewis acids ZrF₄ and HfF₄", Dalton Transactions 2012, 41, 12548. doi:10.1039/C2DT31501G