Lithium iodide, or LiI, is a compound of lithium and iodine. When exposed to air, it becomes yellow in color, due to the oxidation of iodide to iodine.[2] It crystallizes in the NaCl motif.[3] It can participate in various hydrates.[4]

Lithium iodide
Lithium iodide
__ Li+     __ I
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.735 Edit this at Wikidata
UNII
  • InChI=1S/HI.Li/h1H;/q;+1/p-1 checkY
    Key: HSZCZNFXUDYRKD-UHFFFAOYSA-M checkY
  • InChI=1/HI.Li/h1H;/q;+1/p-1
    Key: HSZCZNFXUDYRKD-REWHXWOFAM
  • [Li+].[I-]
Properties
LiI
Molar mass 133.85 g/mol
Appearance White crystalline solid
Density 4.076 g/cm3 (anhydrous)
3.494 g/cm3 (trihydrate)
Melting point 469 °C (876 °F; 742 K)
Boiling point 1,171 °C (2,140 °F; 1,444 K)
1510 g/L (0 °C)
1670 g/L (25 °C)
4330 g/L (100 °C) [1]
Solubility soluble in ethanol, propanol, ethanediol, ammonia
Solubility in methanol 3430 g/L (20 °C)
Solubility in acetone 426 g/L (18 °C)
−50.0·10−6 cm3/mol
1.955
Thermochemistry
0.381 J/g K or 54.4 J/mol K
75.7 J/mol K
-2.02 kJ/g or −270.48 kJ/mol
-266.9 kJ/mol
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
0
0
Flash point Non-flammable
Safety data sheet (SDS) External MSDS
Related compounds
Other anions
Lithium fluoride
Lithium chloride
Lithium bromide
Lithium astatide
Other cations
Sodium iodide
Potassium iodide
Rubidium iodide
Caesium iodide
Francium 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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Applications

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LiI chains grown inside double-wall carbon nanotubes.[5]

Lithium iodide is used as a solid-state electrolyte for high-temperature batteries. It is also the standard electrolyte in artificial pacemakers[6] due to the long cycle life it enables.[7] The solid is used as a phosphor for neutron detection.[8] It is also used, in a complex with Iodine, in the electrolyte of dye-sensitized solar cells.

In organic synthesis, LiI is useful for cleaving C-O bonds. For example, it can be used to convert methyl esters to carboxylic acids:[9]

RCO2CH3 + LiI → RCO2Li + CH3I

Similar reactions apply to epoxides and aziridines.

Lithium iodide was used as a radiocontrast agent for CT scans. Its use was discontinued due to renal toxicity. Inorganic iodine solutions suffered from hyperosmolarity and high viscosities. Current iodinated contrast agents are organoiodine compounds.[10]

It is also useful in MALDI imaging mass spectrometry of lipids by adding lithium salts to the matrix solution

[11]

See also

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References

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  1. ^ Patnaik, Pradyot (2002) Handbook of Inorganic Chemicals. McGraw-Hill, ISBN 0-07-049439-8
  2. ^ "Lithium iodide" (PDF). ESPI Corp. MSDS. Archived from the original (PDF) on 2008-03-09. Retrieved 2005-09-16.
  3. ^ Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.
  4. ^ Wietelmann, Ulrich and Bauer, Richard J. (2005) "Lithium and Lithium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH: Weinheim. doi:10.1002/14356007.a15_393.
  5. ^ Senga, Ryosuke; Suenaga, Kazu (2015). "Single-atom electron energy loss spectroscopy of light elements". Nature Communications. 6: 7943. Bibcode:2015NatCo...6.7943S. doi:10.1038/ncomms8943. PMC 4532884. PMID 26228378.
  6. ^ Holmes, C. (2007-09-28). "The Lithium/Iodine-Polyvinylpyridine Pacemaker Battery - 35 years of Successful Clinical Use". ECS Transactions. 6 (5): 1–7. Bibcode:2007ECSTr...6e...1H. doi:10.1149/1.2790382. ISSN 1938-5862. S2CID 138189063.
  7. ^ Hanif, Maryam (2008). "The Pacemaker Battery - Review Article". UIC Bioengineering Student Journal.
  8. ^ Nicholson, K. P.; et al. (1955). "Some lithium iodide phosphors for slow neutron detection". Br. J. Appl. Phys. 6 (3): 104–106. Bibcode:1955BJAP....6..104N. doi:10.1088/0508-3443/6/3/311.
  9. ^ Charette, André B.; Barbay, J. Kent and He, Wei (2005) "Lithium Iodide" in Encyclopedia of Reagents for Organic Synthesis, John Wiley & Sons. doi:10.1002/047084289X.rl121.pub2
  10. ^ Lusic, Hrvoje; Grinstaff, Mark W. (2013). "X-ray-Computed Tomography Contrast Agents". Chemical Reviews. 113 (3): 1641–66. doi:10.1021/cr200358s. PMC 3878741. PMID 23210836.
  11. ^ Petit, Cerruti; Touboul, Laprévote (2011). "MALDI imaging mass spectrometry of lipids by adding lithium salts to the matrix solution". Analytical and Bioanalytical Chemistry. 401 (1): 75–87. doi:10.1007/s00216-011-4814-9. PMC 3878741. PMID 21380605.
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