Zinc iodide

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Zinc iodide
Portion of ZnI2 lattice (ICD Code2404).png
Names
IUPAC name
Zinc iodide
Other names
Zinc(II) iodide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.347 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/2HI.Zn/h2*1H;/q;;+2/p-2 Yes check.svgY
    Key: UAYWVJHJZHQCIE-UHFFFAOYSA-L Yes check.svgY
  • InChI=1/2HI.Zn/h2*1H;/q;;+2/p-2
    Key: UAYWVJHJZHQCIE-NUQVWONBAB
  • I[Zn]I
Properties
ZnI2
Molar mass 319.19 g/mol
Appearancewhite 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).
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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.

Contents

Preparation

It can be prepared by the direct reaction of zinc and iodine in water [1] [2] or refluxing ether: [3]

Zn + I2 → ZnI2

Absent a solvent, the elements do not combine directly at room temperature. [4]

Structure as solid, gas, and in solution

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]

Applications

References

  1. 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.
  2. DeMeo, S. (1995). "Synthesis and Decomposition of Zinc Iodide: Model Reactions for Investigating Chemical Change in the Introductory Laboratory" . Journal of Chemical Education. 72 (9): 836. Bibcode:1995JChEd..72..836D. doi:10.1021/ed072p836.
  3. Eagleson, M. (1994). Concise Encyclopedia Chemistry . Walter de Gruyter. ISBN   3-11-011451-8.
  4. 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.
  5. 1 2 3 Wells, A. F. (1984). Structural Inorganic Chemistry (5th ed.). Oxford Science Publications. ISBN   0-19-855370-6.
  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.
  7. Wakita, H.; Johansson, G.; Sandström, M.; Goggin, P. L.; Ohtaki, H. (1991). "Structure determination of zinc iodide complexes formed in aqueous solution". Journal of Solution Chemistry. 20 (7): 643–668. doi:10.1007/BF00650714. S2CID   97496242.
  8. Baker, A.; Dutton, S.; Kelly, D., eds. (2004). Composite Materials for Aircraft Structures (2nd ed.). AIAA (American Institute of Aeronautics & Astronautics). ISBN   1-56347-540-5.
  9. Ezrin, M. (1996). Plastics Failure Guide. Hanser Gardner Publications. ISBN   1-56990-184-8.
  10. USpatent 4109065,Will, F. G.; Secor, F. W.,"Rechargeable aqueous zinc-halogen cell",issued 1978-08-22, assigned to General Electric
  11. Hayat, M. A. (2000). Principles and Techniques of Electron Microscopy: Biological Applications (4th ed.). Cambridge University Press. ISBN   0-521-63287-0.
  12. Bercaw, John E.; Diaconescu, Paula L.; Grubbs, Robert H.; Kay, Richard D.; Kitching, Sarah; Labinger, Jay A.; Li, Xingwei; Mehrkhodavandi, Parisa; Morris, George E. (2006-11-01). "On the Mechanism of the Conversion of Methanol to 2,2,3-Trimethylbutane (Triptane) over Zinc Iodide". The Journal of Organic Chemistry. 71 (23): 8907–8917. doi:10.1021/jo0617823. ISSN   0022-3263. PMID   17081022.
  13. Rohe, Dieter M. M.; Wolf, Hans Uwe (2007), "Zinc Compounds", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, pp. 1–6, doi:10.1002/14356007.a28_537, ISBN   978-3527306732