Zinc iodide is theinorganic 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.
The structure of solid ZnI2 is unusual relative to the dichloride. While zinc centers are tetrahedrally coordinated, as inZnCl2, 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 theP4O10 structure.[5][6]
Molecular ZnI2 is linear as predicted byVSEPR 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]
United Statespatent 4,109,065[10] describes a rechargeable aqueous zinc-halogencell that includes an aqueous electrolytic solution containing a zinc salt selected from the class consisting ofzinc bromide, zinc iodide, and mixtures thereof, in both positive and negativeelectrode compartments.
In combination withosmium tetroxide, ZnI2 is used as a stain in electron microscopy.[11]
^F. Wagenknecht; R. Juza (1963). "Zinc iodide". In G. Brauer (ed.).Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. NY, NY: Academic Press. p. 1073.
^Gilbert, George; Houston, Kelly; Jacobsen, Jerrold J.; Phillips, David (2022) [6 Mar 2012].Zinc iodine reaction (web video). American Chemical Society, Division of Chemical Education – via ChemEdX.
^abcWells, A. F. (1984).Structural Inorganic Chemistry (5th ed.). Oxford Science Publications.ISBN0-19-855370-6.
^Fourcroy, P. H.; Carré, D.; Rivet, J. (1978). "Structure Cristalline de l'Iodure de Zinc ZnI2".Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry.34 (11):3160–3162.Bibcode:1978AcCrB..34.3160F.doi:10.1107/S0567740878010390.
^US patent 4109065, Will, F. G.; Secor, F. W., "Rechargeable aqueous zinc-halogen cell", issued 1978-08-22, assigned to General Electric
^Hayat, M. A. (2000).Principles and Techniques of Electron Microscopy: Biological Applications (4th ed.). Cambridge University Press.ISBN0-521-63287-0.
.png)
