Rhodium trifluoride

Rhodium(III) fluoride or rhodium trifluoride is the inorganic compound with the formula RhF₃. It is a red-brown, diamagnetic solid.

Rhodium trifluoride

Names
IUPAC name Rhodium(III) fluoride
Other names Rhodium trifluoride
Identifiers
CAS Number	60804-25-3
3D model (JSmol)	Interactive image
ChemSpider	28687977
PubChem CID	21688473
CompTox Dashboard (EPA)	DTXSID601336941 DTXSID90578682, DTXSID601336941
InChI InChI=1S/3FH.Rh/h3*1H;/q;;;+3/p-3 Key: TXUZMGFRPPRPQA-UHFFFAOYSA-K
SMILES [F-].[F-].[F-].[Rh+3]
Properties
Chemical formula	RhF3
Molar mass	159.90070 g·mol−1
Appearance	red-brown solid
Density	5.38 g/cm3[1]
Structure
Crystal structure	Trigonal
Space group	R3c
Lattice constant	a = 4.873, c = 13.550[2]
Formula units (Z)	6
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis and structure

The compound is prepared by fluorination of rhodium trichloride:

2 RhCl₃ + 3 F₂ → 2 RhF₃ + 3 Cl₂

It can also be obtained by direct combination of the elements:^[3]

2 Rh + 3 F₂ → 2 RhF₃

Anhydrous RhF₃ is insoluble in water and does not react with it, but the hydrates RhF₃·6H₂O and RhF₃·9H₂O can be prepared by adding hydrofluoric acid to aqueous rhodium(III) solutions.^[3]

According to X-ray crystallography, the compound adopts the same structure as vanadium trifluoride, wherein the metal achieves octahedral coordination geometry.^[2]