Tellurium tetraiodide

Crystal structure
__ Te 4+      __ I - Te 4 I 16 unit in the crystal structure of TeI 4
General
Surname	Tellurium tetraiodide
other names	Tellurium (IV) iodide
Ratio formula	Part 4
Brief description	gray to black solid with a pungent odor
External identifiers / databases
CAS number 7790-48-9 EC number 232-210-5 ECHA InfoCard 100.029.282 PubChem 82255 Wikidata Q2346228
properties
Molar mass	635.22 g mol −1
Physical state	firmly
density	5.403 g cm −3
Melting point	280 ° C
solubility	Decomposes in water
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 301-314-318 P: 260-301 + 310-303 + 361 + 353-305 + 351 + 338-405-501
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Tellurium tetraiodide is an inorganic chemical compound of tellurium from the group of iodides .

Extraction and presentation

Tellurium tetraiodide can be obtained by reacting telluric acid with hydrogen iodide .

${\displaystyle \mathrm {Te(OH)_{6}+6\ HI\longrightarrow TeI_{4}+I_{2}+6\ H_{2}O} }$

It can also be obtained by reacting tellurium and iodine , whereby tellurium diiodide and tellurium monoiodide can also be formed depending on the reaction conditions.

${\displaystyle \mathrm {Te+2\ I_{2}\longrightarrow TeI_{4}\rightleftharpoons TeI_{2}+I_{2}} }$

properties

Tellurium tetraiodide is an iron-gray solid that decomposes slowly in cold water and rapidly in warm water to form tellurium dioxide and hydrogen iodide . It is stable even in moist air and decomposes when heated, releasing iodine . It is soluble in hydriodic acid with formation of H [TeI5] and somewhat soluble in acetone . 5 modifications of tellurium tetraiodide are known, all of which are made up of tetrameric molecules. The δ-form is the thermodynamically most stable form. This derives (as well as the α-, β- and γ-form) structurally from the ε-form from which a structure of Kuban has -type as four linked via halide bridges TeI ₃ ⁺ I ^- describe units composed leaves. The individual shapes differ in that a part ₃ corner of the cube is shifted.

See also

• Tellurium tetrabromide
• Tellurium tetrachloride
• Tellurium tetrafluoride

Individual evidence

1. ↑ ^{a b c d e f g h} data sheet Tellurium (IV) iodide, 99% (metals basis) from AlfaAesar, accessed on December 17, 2013 ( PDF )(JavaScript required) .
2. ↑ ^{a b} Georg Brauer , with the collaboration of Marianne Baudler a . a. (Ed.): Handbook of Preparative Inorganic Chemistry . 3rd, revised edition. tape I . Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , pp. 435 .
3. ^ JJ Zuckerman: Inorganic Reactions and Methods, The Formation of Bonds to Halogens . John Wiley & Sons, 2009, ISBN 0-470-14538-2 , pp. 59 ( limited preview in Google Book search).
4. ↑ Erwin Riedel, Christoph Janiak: Inorganic Chemistry . Walter de Gruyter, 2011, ISBN 3-11-022567-0 , p. 461 ( limited preview in Google Book search).
5. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 632.