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

Related Research Articles

<span class="mw-page-title-main">Iodine</span> Chemical element with atomic number 53 (I)

Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at 114 °C (237 °F), and boils to a violet gas at 184 °C (363 °F). The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek Ιώδης, meaning 'violet'.

<span class="mw-page-title-main">Hydroiodic acid</span> Aqueous solution of hydrogen iodide

Hydroiodic acid is a colorless liquid. It is an aqueous solution of hydrogen iodide with the chemical formula HI(aq). It is a strong acid, in which hydrogen iodide is ionized completely in an aqueous solution. Concentrated aqueous solutions of hydrogen iodide are usually 48% to 57% HI by mass.

<span class="mw-page-title-main">Zinc chloride</span> Chemical compound

Zinc chloride is an inorganic chemical compound with the formula ZnCl2·nH2O, with n ranging from 0 to 4.5, forming hydrates. Zinc chloride, anhydrous and its hydrates, are colorless or white crystalline solids, and are highly soluble in water. Five hydrates of zinc chloride are known, as well as four forms of anhydrous zinc chloride.

<span class="mw-page-title-main">Hydrogen iodide</span> Chemical compound

Hydrogen iodide (HI) is a diatomic molecule and hydrogen halide. Aqueous solutions of HI are known as hydroiodic acid or hydriodic acid, a strong acid. Hydrogen iodide and hydroiodic acid are, however, different in that the former is a gas under standard conditions, whereas the other is an aqueous solution of the gas. They are interconvertible. HI is used in organic and inorganic synthesis as one of the primary sources of iodine and as a reducing agent.

<span class="mw-page-title-main">Metal ammine complex</span> Class of chemical compounds

In coordination chemistry, metal ammine complexes are metal complexes containing at least one ammonia ligand. "Ammine" is spelled this way for historical reasons; in contrast, alkyl or aryl bearing ligands are spelt with a single "m". Almost all metal ions bind ammonia as a ligand, but the most prevalent examples of ammine complexes are for Cr(III), Co(III), Ni(II), Cu(II) as well as several platinum group metals.

<span class="mw-page-title-main">Triiodide</span> Ion

In chemistry, triiodide usually refers to the triiodide ion, I
3
. This anion, one of the polyhalogen ions, is composed of three iodine atoms. It is formed by combining aqueous solutions of iodide salts and iodine. Some salts of the anion have been isolated, including thallium(I) triiodide (Tl+[I3]) and ammonium triiodide ([NH4]+[I3]). Triiodide is observed to be a red colour in solution.

<span class="mw-page-title-main">Copper(I) iodide</span> Chemical compound

Copper(I) iodide is an inorganic compound with the chemical formula CuI. It is also known as cuprous iodide. It is useful in a variety of applications ranging from organic synthesis to cloud seeding.

<span class="mw-page-title-main">Zinc bromide</span> Chemical compound

Zinc bromide (ZnBr2) is an inorganic compound with the chemical formula ZnBr2. It is a colourless salt that shares many properties with zinc chloride (ZnCl2), namely a high solubility in water forming acidic solutions, and good solubility in organic solvents. It is hygroscopic and forms a dihydrate ZnBr2·2H2O.

<span class="mw-page-title-main">Zinc cyanide</span> Chemical compound

Zinc cyanide is the inorganic compound with the formula Zn(CN)2. It is a white solid that is used mainly for electroplating zinc but also has more specialized applications for the synthesis of organic compounds.

<span class="mw-page-title-main">Zinc nitrate</span> Chemical compound

Zinc nitrate is an inorganic chemical compound with the formula Zn(NO3)2. This colorless, crystalline salt is highly deliquescent. It is typically encountered as a hexahydrate Zn(NO3)2·6H2O. It is soluble in both water and alcohol.

Terbium(III) iodide (TbI3) is an inorganic chemical compound.

Iodine compounds are compounds containing the element iodine. Iodine can form compounds using multiple oxidation states. Iodine is quite reactive, but it is much less reactive than the other halogens. For example, while chlorine gas will halogenate carbon monoxide, nitric oxide, and sulfur dioxide, iodine will not do so. Furthermore, iodination of metals tends to result in lower oxidation states than chlorination or bromination; for example, rhenium metal reacts with chlorine to form rhenium hexachloride, but with bromine it forms only rhenium pentabromide and iodine can achieve only rhenium tetraiodide. By the same token, however, since iodine has the lowest ionisation energy among the halogens and is the most easily oxidised of them, it has a more significant cationic chemistry and its higher oxidation states are rather more stable than those of bromine and chlorine, for example in iodine heptafluoride.

<span class="mw-page-title-main">Beryllium chloride</span> Chemical compound

Beryllium chloride is an inorganic compound with the formula BeCl2. It is a colourless, hygroscopic solid that dissolves well in many polar solvents. Its properties are similar to those of aluminium chloride, due to beryllium's diagonal relationship with aluminium.

<span class="mw-page-title-main">Hypoiodous acid</span> Chemical compound

Hypoiodous acid is an inorganic compound with the chemical formula HIO. It forms when an aqueous solution of iodine is treated with mercuric or silver salts. It rapidly decomposes by disproportionation:

Zinc compounds are chemical compounds containing the element zinc which is a member of the group 12 of the periodic table. The oxidation state of zinc in most compounds is the group oxidation state of +2. Zinc may be classified as a post-transition main group element with zinc(II). Zinc compounds are noteworthy for their nondescript appearance and behavior: they are generally colorless, do not readily engage in redox reactions, and generally adopt symmetrical structures.

Iron(II) iodide is an inorganic compound with the chemical formula FeI2. It is used as a catalyst in organic reactions.

Europium(III) iodide is an inorganic compound containing europium and iodine with the chemical formula EuI3.

<span class="mw-page-title-main">Gadolinium(III) iodide</span> Chemical compound

Gadolinium(III) iodide is an iodide of gadolinium, with the chemical formula of GdI3. It is a yellow, highly hygroscopic solid with a bismuth(III) iodide-type crystal structure. In air, it quickly absorbs moisture and forms hydrates. The corresponding oxide iodide is also readily formed at elevated temperature.

Astatine compounds are compounds that contain the element astatine (At). As this element is very radioactive, few compounds have been studied. Less reactive than iodine, astatine is the least reactive of the halogens. Its compounds have been synthesized in nano-scale amounts and studied as intensively as possible before their radioactive disintegration. The reactions involved have been typically tested with dilute solutions of astatine mixed with larger amounts of iodine. Acting as a carrier, the iodine ensures there is sufficient material for laboratory techniques to work. Like iodine, astatine has been shown to adopt odd-numbered oxidation states ranging from −1 to +7.

Ruthenium(III) iodide is a chemical compound containing ruthenium and iodine with the formula RuI3. It is a black solid.

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