Oxidizing rhodium with sulfuric acid: The sulfates Rh2(SO4)3 and Rh2(SO4)3∙2H2O

Journal articleResearchPeer reviewed

Publication data


ByStefan Schwarzer, Annika Betke, Christian Logemann, Mathias S. Wickleder
Original languageEnglish
Published inEuropean Journal of Inorganic Chemistry, None(3)
Pages752-758
Editor (Publisher)Wiley-Blackwell
ISSN1099-0682
DOI/Linkhttps://doi.org/10.1002/ejic.201601247
Publication statusPublished – 2017

The reaction of elemental rhodium and concentrated sulfuric acid (97 %) at 400 °C leads to red plate‐shaped single crystals of Rh2(SO4)3 [trigonal, R3, Z = 6, a = 806.8(1) pm, c = 2204.8(4) pm, V = 1242.8(4) × 106 pm3]. The same reaction carried out at a temperature of 475 °C leads to orange crystals of Rh2(SO4)3·2H2O [orthorhombic, Pnma, Z = 4, a = 920.46(2) pm, b = 1244.47(3) pm, c = 833.37(2) pm, V = 954.61(4) × 106 pm3]. Thermal analysis and X‐ray powder diffraction measurements were performed to investigate the decomposition and resulting residues of the compounds. For both compounds the decomposition occurs through two steps and is finished at around 1000 °C at the stage of elemental rhodium. Additionally both sulfates were characterized by means of IR spectroscopy.