Vanadium (II) iodide
Crystal structure | ||||||||||||||||
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__ V 2+ __ I - | ||||||||||||||||
General | ||||||||||||||||
Surname | Vanadium (II) iodide | |||||||||||||||
other names |
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Ratio formula | VI 2 | |||||||||||||||
Brief description |
red-violet, crystalline solid |
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properties | ||||||||||||||||
Molar mass | 304.75 g mol −1 | |||||||||||||||
Physical state |
firmly |
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density |
5.44 g cm −3 |
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Melting point |
≈ 800 ° C |
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boiling point |
850 ° C |
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solubility |
dissolves in water with formation of [V (H 2 O) 6 ] 2+ ions |
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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 . |
Vanadium (II) iodide is a chemical compound of the elements vanadium and iodine .
Extraction and presentation
Vanadium (II) iodide can be obtained by disproportionation of vanadium (III) iodide at 280 ° C:
The representation from the elements at around 500 ° C is also possible. If the reaction takes place with a slight excess of iodine, the black form of the compound is created.
properties
Physical Properties
Vanadium (II) iodide comes in two forms. The red form only dissolves after several hours in moist air. In water it dissolves only slowly, but completely, even when heated. In contrast, the black form is as sensitive to moisture as vanadium (III) iodide . The red form has very thin leaflets, the black appears in hexagonal columns. The trigonal crystal structure of the red form corresponds to the trigonal form of cadmium (II) iodide with the space group P 3 m 1 (space group no.164 ) and the lattice parameters a = 4,000 Å , c = 6,670 Å.
Chemical properties
Vanadium (II) iodide is a powerful reducing agent that even reduces nitrogen to hydrazine in the presence of magnesium hydroxide .
It dissolves in water with the formation of [V (H 2 O) 6 ] 2+ ions:
Individual evidence
- ^ A b A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1545.
- ↑ a b Vanadium (II) iodide on webelements.com
- ^ A b c A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1550.
- ↑ harmonized classification for this substance . A labeling of vanadium diiodide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), retrieved on July 28, 2019, is reproduced from a self-classification by the distributor . There is not yet a
- ↑ Lothar Kolditz: Inorganic Chemistry Part 2 . VEB Deutscher Verlag der Wissenschaften, Berlin, 1980, p. 641.
- ↑ a b 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. 1413.