Rhodium (III) iodide

Crystal structure
__ Rh 3+      __ I -
General
Surname	Rhodium (III) iodide
other names	Rhodium triiodide Rhodium iodide
Ratio formula	RhI 3
Brief description	black odorless solid
External identifiers / databases
CAS number 15492-38-3 314071-45-9 (hydrate) EC number 239-521-5 ECHA InfoCard 100.035.913 PubChem 84945 Wikidata Q4202670
properties
Molar mass	483.62 g mol −1
Physical state	firmly
density	6.4 g cm −3
solubility	almost insoluble in water
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: 413 P: 273-501
Toxicological data	> 5000 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Rhodium (III) iodide is an inorganic chemical compound of rhodium from the group of iodides . It is used as a catalyst in the Monsanto process , for example .

Extraction and presentation

Rhodium (III) iodide can be obtained by reacting an aqueous solution of potassium hexachlororhodate (III) K ₃ RhCl ₆ with a concentrated potassium iodide solution.

${\displaystyle \mathrm {2\ K_{3}[RhCl_{6}]+6\ KI\longrightarrow 2\ RhI_{3}\downarrow +\ 12\ KCl} }$

properties

Rhodium (III) iodide is a hygroscopic black, odorless solid that is insoluble in water. It is insoluble in acids and organic solvents and has a monoclinic crystal structure with the space group C 2 / m (space group no. 12) and the lattice parameters a = 677 pm, b = 1172 pm, c = 683 pm and β = 109.3 °. This corresponds to that of yttrium (III) chloride .

Individual evidence

1. ↑ ^{a b c d e f g} data sheet Rhodium (III) iodide, 99.9% (metals basis), Rh 20.8% min from AlfaAesar, accessed on August 17, 2019 ( PDF )(JavaScript required) .
2. ↑ ^{a b c} Georg Brauer (Ed.) U. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume III, Ferdinand Enke, Stuttgart 1981, ISBN 3-432-87823-0 , p. 1740.
3. ^ Peter Paetzold: Chemistry: An introduction . Walter de Gruyter, 2009, ISBN 3-11-021135-1 , p. 204 ( limited preview in Google Book search).