Chemistry:Praseodymium(IV) fluoride

Praseodymium(IV) fluoride

Names
Other names tetrafluoropraseodymium, praseodymium tetrafluoride
Identifiers
CAS Number	15192-24-2 Y
3D model (JSmol)	Interactive image
ChemSpider	9588184
PubChem CID	11413297
InChI InChI=1S/4FH.Pr/h4*1H;/q;;;;+4/p-4 Key: AQHKOMUMLGCMJB-UHFFFAOYSA-J
SMILES F[Pr](F)(F)F
Properties
Chemical formula	F4Pr
Molar mass	216.90127 g·mol−1
Appearance	light-yellow crystals
Density	g/cm3
Solubility in water	reacts with water
Hazards
GHS pictograms
GHS Signal word	Warning
Related compounds
Other cations	CeF4
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Praseodymium(IV) fluoride (also praseodymium tetrafluoride) is a binary inorganic compound, a highly oxidised metal salt of praseodymium and fluoride with the chemical formula PrF₄.

Synthesis

Praseodymium(IV) fluoride can be prepared by the effect of krypton difluoride on praseodymium(IV) oxide:

$\mathsf{P}\mathsf{r}{\mathsf{O}}_{\mathsf{2}}\mathsf{+}\mathsf{2}\mathsf{K}\mathsf{r}{\mathsf{F}}_{\mathsf{2}}\stackrel{}{\to }\mathsf{P}\mathsf{r}{\mathsf{F}}_{\mathsf{4}}\mathsf{+}{\mathsf{O}}_{\mathsf{2}}\mathsf{+}\mathsf{2}\mathsf{K}\mathsf{r}$

Praseodymium(IV) fluoride can also be made by the dissolution of sodium hexafluoropraseodymate(IV) in liquid hydrogen fluoride:

$\mathsf{N}{\mathsf{a}}_{\mathsf{2}}\mathsf{[}\mathsf{P}\mathsf{r}{\mathsf{F}}_{\mathsf{6}}\mathsf{]}\mathsf{+}\mathsf{2}\mathsf{H}\mathsf{F}\stackrel{}{\to }\mathsf{P}\mathsf{r}{\mathsf{F}}_{\mathsf{4}}\mathsf{\downarrow }\mathsf{+}\mathsf{2}\mathsf{N}\mathsf{a}\mathsf{H}{\mathsf{F}}_{\mathsf{2}}$

Properties

Praseodymium(IV) fluoride forms light yellow crystals. The crystal structure is anticubic and isomorphic to that of uranium tetrafluoride UF₄.

Decomposes when heated:

$\mathsf{2}\mathsf{P}\mathsf{r}{\mathsf{F}}_{\mathsf{4}}\stackrel{90^{o}C}{\to }\mathsf{2}\mathsf{P}\mathsf{r}{\mathsf{F}}_{\mathsf{3}}\mathsf{+}{\mathsf{F}}_{\mathsf{2}}$

Due to the high normal potential of the tetravalent praseodymium cations (Pr3+ / Pr4+: +3.2 V), praseodymium(IV) fluoride decomposes in water, releasing oxygen, O₂.

See also

• Praseodymium(III) fluoride
• Uranium tetrafluoride