Rhenium (III) iodide

Crystal structure
__ Re 3+      __ I -
Crystal system	monoclinic
Space group	P 2 1 / m
Lattice parameters	a = 923.4 pm, b = 1130.9 pm, c = 879.9 pm, β = 110.25 °
General
Surname	Rhenium (III) iodide
other names	Rhenium triiodide
Ratio formula	ReI 3
Brief description	black solid
External identifiers / databases
CAS number 15622-42-1 EC number 239-698-9 ECHA InfoCard 100.036.074 PubChem 12984320 Wikidata Q4202668
properties
Molar mass	566.92 g mol −1
Physical state	firmly
density	6.37 g cm −3
Melting point	800 ° C (decomposition)
solubility	Slightly soluble in water and dilute acids
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 315-319-335 P: 261-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Rhenium (III) iodide is an inorganic chemical compound of rhenium from the group of iodides .

Extraction and presentation

Rhenium (III) iodide can be obtained by reacting a perrhenic acid solution with hydriodic acid and ethanol or methanol .

${\displaystyle \mathrm {HReO_{4}+3\ HI+2\ C_{2}H_{5}OH\longrightarrow ReI_{3}+4\ H_{2}O+2\ CH_{3}CHO} }$

It can also be achieved by thermal decomposition of rhenium (IV) iodide at 350 ° C

${\displaystyle \mathrm {2\ ReI_{4}\longrightarrow 2\ ReI_{3}+I_{2}} }$

or by reaction of rhenium (III) chloride with boron (III) iodide at 310 ° C.

properties

Rhenium (III) iodide is a black, shiny solid with needle-like crystals, which is sparingly soluble in water and dilute acids . It is almost insoluble in methanol , ethanol , ether, petroleum ether and carbon tetrachloride . It is soluble in liquid ammonia with solvolysis . In a vacuum, it slowly decomposes, especially at elevated temperatures, releasing iodine . It breaks down into rhenium and iodine when heated to 800 ° C. Rhenium (III) iodide has a monoclinic crystal structure with the space group P 2 ₁ / m (space group no. 11) and the lattice parameters a = 923.4 pm, b = 1130.9 pm, c = 879.9 pm and β = 110.25 °. The crystal structure consists of Re ₃ I ₉ units (island structure), which are linked by Re-I-Re bridges to form zigzag chains.

Individual evidence

1. ↑ ^{a b c d e f g h} 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. 1615.
2. ↑ ^{a b c} data sheet Rhenium (III) iodide, 97% from Sigma-Aldrich , accessed on July 28, 2013 ( PDF ).
3. ↑ Hans Peter Latscha, Martin Mutz: Chemistry of the elements . Springer, 2011, ISBN 3-642-16915-5 , pp. 239 ( limited preview in Google Book search).