Rhodium(III) sulfate

Identifiers
CAS Number	(tetrahydrate): 15274-78-9 N[PubChem]
3D model (JSmol)	(monohydrate): Interactive image (tetrahydrate): Interactive image
ChemSpider	140097
ECHA InfoCard	100.030.909
PubChem CID	(monohydrate): 91886288 (tetrahydrate): 91886287
CompTox Dashboard (EPA)	DTXSID20890662
InChI (monohydrate): InChI=1S/3H2O4S.H2O.2Rh/c3*1-5(2,3)4;;;/h3*(H2,1,2,3,4);1H2;;/q;;;;2*+3/p-6 Key: MPJHDLITZOASKY-UHFFFAOYSA-H (tetrahydrate): InChI=1S/3H2O4S.4H2O.2Rh/c3*1-5(2,3)4;;;;;;/h3*(H2,1,2,3,4);4*1H2;;/q;;;;;;;2*+3/p-6 Key: JJITWKYISWZJBI-UHFFFAOYSA-H
SMILES (monohydrate): O.[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[Rh+3].[Rh+3] (tetrahydrate): O.O.O.O.[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[O-]S(=O)(=O)[O-].[Rh+3].[Rh+3]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Rhodium(III) sulfate refers to inorganic compounds of the formula Rh₂(SO₄)₃. It is a red crystalline solid.^[1]

Preparation

The first attempts to produce rhodium(III) sulfate was in 1929 with the reaction of rhodium(III) hydroxide and sulfuric acid . They reported that there were two different types of hydrates, the yellow colored tetradecahydrate and the red colored tetrahydrate. This not conformed due to the lack of structural proof. Then further investigations has been done on the hexahydrate and the tetradecahydrate with x-ray diffraction. The first structural elucidations have been done at 2009 which conformed the existence of the chemical.

Then at 2016, a much efficient production method was reported. This method used rhodium metal and sulfuric acid to make the rhodium(III) sulfate. The two compounds were heated together at 400°C to make the anhydrous compound. It was shown that if it was heated at 475°C instead, it would make the dihydrate.