Arsenic (III) iodide

Crystal structure
__ As 3+      __ I -
General
Surname	Arsenic (III) iodide
other names	Arsenic triiodide Triiodarsine
Ratio formula	AsI 3
Brief description	red solid with a pungent odor
External identifiers / databases
CAS number 7784-45-4 EC number 232-068-4 ECHA InfoCard 100.029.153 PubChem 24575 Wikidata Q2661846
properties
Molar mass	455.64 g mol −1
Physical state	firmly
density	4.38 g cm −3
Melting point	141.8 ° C
boiling point	403 ° C
solubility	slow decomposition in water Easily soluble in carbon disulfide and trichloromethane
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 301-331-410 P: 261-273-301 + 310-311-501
Thermodynamic properties
ΔH f 0	−58.2 kJ / mol
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Arsenic (III) iodide is an inorganic chemical compound of arsenic from the group of iodides .

Extraction and presentation

Arsenic (III) iodide can be obtained by reacting arsenic (III) chloride with potassium iodide or from the elements.

${\displaystyle \mathrm {AsCl_{3}+3\ KI\longrightarrow AsI_{3}+3\ KCl} }$

${\displaystyle \mathrm {2\ As+3\ I_{2}\longrightarrow 2\ AsI_{3}} }$

It can also be obtained from arsenic (III) oxide by reacting with hydrochloric acid and a potassium iodide solution.

${\displaystyle \mathrm {As_{2}O_{3}+6\ HCl+6\ KI\longrightarrow 2\ AsI_{3}+6\ KCl+3\ H_{2}O} }$

properties

Arsenic (III) iodide is a red-orange solid with a pungent odor that slowly decomposes in water.

${\displaystyle \mathrm {AsI_{3}+3\ H_{2}O\longrightarrow H_{3}AsO_{3}+3\ HI} }$

In air it gradually decomposes to iodine and arsenic (III) oxide . It has a trigonal crystal structure with the space group R 3 (space group no.148) . From 110 ° C, the compound is a high-temperature modification with a crystal structure with the space group P 3 ₂ 12 (No. 153) .

use

Arsenic (III) iodide was previously used to treat dermatitis in cats and as Donovan's solution to treat skin inflammation and other conditions.

Individual evidence

1. ↑ ^{a b c d e f g h i} Entry for CAS no. 7784-45-4 in the GESTIS substance database of the IFA , accessed on April 24, 2016(JavaScript required) .
2. ^ Franz von Bruchhausen, Siegfried Ebel, Eberhard Hackenthal: Hager's Handbook of Pharmaceutical Practice: Substances AK . Springer DE, 1999, ISBN 978-3-642-58387-2 , pp. 107 ( limited preview in Google Book search).
3. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-5.
4. ↑ ^{a b} Entry on arsenic (III) iodide in the Hazardous Substances Data Bank , accessed on August 5, 2013.
5. ↑ Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 575.
6. ^ Jean D'Ans, Ellen Lax: Pocket book for chemists and physicists . Springer DE, 1997, ISBN 3-540-60035-3 , pp. 306 ( limited preview in Google Book search).