Iron (II) iodide
Crystal structure | |||||||||||||||||||
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__ Fe 2+ __ I - | |||||||||||||||||||
General | |||||||||||||||||||
Surname | Iron (II) iodide | ||||||||||||||||||
other names |
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Ratio formula | FeI 2 | ||||||||||||||||||
Brief description |
red-purple solid |
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properties | |||||||||||||||||||
Molar mass | 309.65 g mol −1 | ||||||||||||||||||
Physical state |
firmly |
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density |
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Melting point |
587 ° C (decomposition) |
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solubility |
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safety instructions | |||||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Iron (II) iodide is an inorganic chemical compound of iron from the group of iodides .
Extraction and presentation
Iron (II) iodide can be obtained by reacting iron with iodine at 500 ° C.
Alternatively, the synthesis can be carried out by reacting freshly reduced iron with concentrated hydriodic acid under a nitrogen atmosphere in methanol . The hexamethanol solvate initially obtained is then thermally decomposed to anhydrous iodide:
Extremely finely divided iron (II) iodide is obtained by thermal decomposition of tetracarbonyldiiodido iron (II) Fe (CO) 4 I 2 .
properties
Iron (II) iodide is a hygroscopic red-violet to black solid that is soluble in water, ethanol and diethyl ether . Oxidation occurs rapidly in solution and in moist air . It becomes whitish in the air. The solution in water is colorless. It has a trigonal crystal structure of the cadmium (II) hydroxide type with the space group P 3 m 1 (space group no.164) (a = 404 pm, c = 675 pm). The tetrahydrate is a black solid that is soluble in ethanol and water and decomposes at 90-98 ° C.
use
Iron (II) iodide is used as an active ingredient in homeopathic medicines. In the scope it is known as Ferrum iodatum . The ascribed effect especially against glandular diseases has not been scientifically confirmed.
The tetrahydrate is used as a catalyst and for the production of alkali iodides.
Individual evidence
- ↑ a b c d e f g Data sheet Iron (II) iodide, anhydrous, beads, −10 mesh, ≥99.99% trace metals basis from Sigma-Aldrich , accessed on May 23, 2020 ( PDF ).
- ^ A b c Dale L. Perry: Handbook of Inorganic Compounds, Second Edition . Taylor & Francis, 2011, ISBN 1-4398-1462-7 , pp. 483 ( limited preview in Google Book search).
- ↑ a b Roger Blachnik (Ed.): Pocket book for chemists and physicists . Volume III: Elements, Inorganic Compounds and Materials, Minerals . founded by Jean d'Ans, Ellen Lax. 4th, revised and revised edition. Springer, Berlin 1998, ISBN 3-540-60035-3 , pp. 454 ( limited preview in Google Book search).
- ↑ 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. 1645.
- ↑ G. Winter: Iron (II) halides . In: Aaron Wold and John K. Ruff (Eds.): Inorganic Syntheses . tape 14 . McGraw-Hill Book Company, Inc., 1973, ISBN 07-071320-0 ( defective ) , p. 101-104 (English).
- ^ Karl-Heinz Lautenschläger: Pocket book of chemistry . Harri Deutsch Verlag, 2007, ISBN 978-3-8171-1760-4 , pp. 410 ( limited preview in Google Book search).
- ↑ Markus Wiesenauer: Homeopathy for chronic complaints in Große GU Kompasse , pp. 91, 106 & 152, Gräfe and Unzer Verlag GmbH, 2012