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Names | |
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IUPAC name Zinc iodide | |
Other names Zinc(II) iodide | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.030.347 |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
ZnI2 | |
Molar mass | 319.19 g/mol |
Appearance | white solid |
Density | 4.74 g/cm3 |
Melting point | 446 °C (835 °F; 719 K) |
Boiling point | 1,150 °C (2,100 °F; 1,420 K) decomposes |
450 g/100mL (20 °C) | |
−98.0·10−6 cm3/mol | |
Structure | |
Tetragonal, tI96 | |
I41/acd, No. 142 | |
Hazards | |
Flash point | 625 °C (1,157 °F; 898 K) |
Safety data sheet (SDS) | External MSDS |
Related compounds | |
Other anions | Zinc fluoride Zinc chloride Zinc bromide |
Other cations | Cadmium iodide Mercury(I) iodide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Zinc iodide is the inorganic compound with the formula ZnI2. It exists both in anhydrous form and as a dihydrate. Both are white and readily absorb water from the atmosphere. It has no major application.
It can be prepared by the direct reaction of zinc and iodine in water [1] [2] or refluxing ether: [3]
Absent a solvent, the elements do not combine directly at room temperature. [4]
The structure of solid ZnI2 is unusual relative to the dichloride. While zinc centers are tetrahedrally coordinated, as in ZnCl2, groups of four of these tetrahedra share three vertices to form “super-tetrahedra” of composition {Zn4I10}, which are linked by their vertices to form a three-dimensional structure. [5] These "super-tetrahedra" are similar to the P4O10 structure. [5] [6]
Molecular ZnI2 is linear as predicted by VSEPR theory with a Zn-I bond length of 238 pm. [5]
In aqueous solution the following have been detected: Zn(H2O)62+, [ZnI(H2O)5]+, tetrahedral ZnI2(H2O)2, ZnI3(H2O)−, and ZnI42−. [7]