Germanium (II) iodide

Crystal structure
__ Ge 2+      __ I -
Space group	P 3 m 1 (No. 164)
General
Surname	Germanium (II) iodide
other names	Germanium diiodide
Ratio formula	GeI 2
Brief description	yellow solid
External identifiers / databases
CAS number 13573-08-5 EC number 236-998-1 ECHA InfoCard 100.033.620 PubChem 6327215 Wikidata Q4202647
properties
Molar mass	326.45 g mol −1
Physical state	firmly
density	5.37 g cm −3 (25 ° C)
Melting point	428 ° C
boiling point	550 ° C (decomposition)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 314 P: 280-305 + 351 + 338-310
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Germanium (II) iodide is an inorganic chemical compound of germanium from the group of iodides .

Extraction and presentation

Germanium (II) iodide can be obtained by reacting germanium (IV) iodide in hydriodic acid with phosphinic acid and water.

${\displaystyle \mathrm {GeI_{4}+H_{2}O+H_{3}PO_{2}\longrightarrow GeI_{2}+H_{3}PO_{3}+2\ HI} }$

It is also possible to display it by reacting germanium (II) sulfide or germanium (II) oxide with hydriodic acid or from germanium with iodine at 200 - 400 ° C.

${\displaystyle \mathrm {GeO+2\ HI\longrightarrow GeI_{2}+H_{2}O} }$

${\displaystyle \mathrm {GeS+2\ HI\longrightarrow GeI_{2}+H_{2}S} }$

Another display option is:

${\displaystyle \mathrm {HGeCl_{3}+3\ HI\longrightarrow HGeI_{3}+HCl} }$

${\displaystyle \mathrm {HGeI_{3}\longrightarrow GeI_{2}+HI} }$

properties

Germanium (II) iodide is a yellow crystalline solid that is stable in dry air at room temperature, but slowly hydrolyzes to germanium (II) hydroxide in the presence of moisture . It is insoluble in hydrocarbons, but not very soluble in trichloromethane and carbon tetrachloride . The compound has a crystal structure of the polytype 2H of the cadmium (II) iodide type (a = 413 pm; c = 679 pm). It disproportionates into germanium (IV) iodide and iodine at 550 ° C. It reacts with ethyne to form a dimeric complex with a cyclic structure.

use

Germanium (II) iodide forms stable ionic adducts with carbenes . It is also used in the electronics industry to produce germanium layers by epitaxy by disproportionation.

Individual evidence

1. ^ Jean d'Ans, Ellen Lax, Roger Blachnik: Pocket book for chemists and physicists . Springer DE, 1998, ISBN 3-642-58842-5 , pp. 472 ( limited preview in Google Book search).
2. ↑ ^{a b c d} 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. 727.
3. ↑ ^{a b c d e} data sheet Germanium (II) iodide, ≥99.9% trace metals basis from Sigma-Aldrich , accessed on January 19, 2014 ( PDF ).
4. ^ ^{A b} William M. Haynes: CRC Handbook of Chemistry and Physics, 93rd Edition . CRC Press, 2012, ISBN 1-4398-8049-2 , pp. 4–65 ( limited preview in Google Book Search).
5. ^ Wolfgang Kirmse: Carbene Chemistry 2e . Elsevier, 2013, ISBN 0-323-16145-6 , pp. 540 ( limited preview in Google Book search).
6. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 959.
7. ↑ Balaram Sahoo: Inorganic Chemistry . PHI Learning Pvt. Ltd., 2012, ISBN 81-203-4308-5 , pp. 321 ( limited preview in Google Book search).
8. ^ AG Milnes: Heterojunctions and Metal Semiconductor Junctions . Elsevier, 1972, ISBN 0-323-14136-6 , pp. 104 ( limited preview in Google Book search).