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Names | |
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IUPAC name
Manganese(II) iodide
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Identifiers | |
3D model (JSmol)
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ChemSpider | |
ECHA InfoCard | 100.029.274 |
EC Number |
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PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
MnI2 | |
Molar mass | 308.747 g/mol |
Appearance | pink crystalline |
Density | 5.01 g/cm3 |
Melting point | 701 °C (1,294 °F; 974 K) (anhydrous) 80 °C (tetrahydrate) |
Boiling point | 1,033 °C (1,891 °F; 1,306 K) |
soluble | |
+14,400·10−6 cm3/mol | |
Structure | |
Rhombohedral, hP3, SpaceGroup = P-3m1, No. 164 | |
octahedral | |
Hazards[1] | |
GHS labelling: | |
Danger | |
H360 | |
P201, P202, P281, P308+P313, P405, P501 | |
NFPA 704 (fire diamond) | |
Flash point | non-flammable |
Related compounds | |
Other anions
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Manganese(II) fluoride Manganese(II) chloride Manganese(II) bromide |
Other cations
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Iron(II) iodide Cobalt(II) iodide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Manganese(II) iodide is the chemical compound composed of manganese and iodide with the formula MnI2(H2O)n. The tetrahydrate is a pink solid while the anhydrous derivative is beige.[2] Both forms feature octahedral Mn centers. Unlike MnCl2(H2O)4 and MnBr2(H2O)4 which are cis, MnI2(H2O)4 is trans.[3]
Anhydrous MnI2 is prepared from the elements:[4]
The tetrahydrate can be prepared by treating manganese(II) carbonate with hydriodic acid. The anhydrous form can be produced from it by dehydration in a vacuum.[2]
Samples turn brown in air under the influence of light as a result of the oxidation of the iodide ion to iodine.[5] It has a trigonal crystal structure of the cadmium iodide type (polytype 2H)[6][7] with the space group P3m1 (space group no. 164). It dissolves in water and decomposes.[5] The tetrahydrate has a monoclinic crystal structure with the space group P21/c (No. 14).[3]
It is often used in the lighting industry.[8]