Lithium iodide explained

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.^[1] It crystallizes in the NaCl motif.^[2] It can participate in various hydrates.^[3]

Applications

Lithium iodide is used as a solid-state electrolyte for high-temperature batteries. It is also the standard electrolyte in artificial pacemakers^[4] due to the long cycle life it enables.^[5] The solid is used as a phosphor for neutron detection.^[6] 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:^[7]

RCO₂CH₃ + LiI → RCO₂Li + CH₃ISimilar 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.^[8]

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

^[9]

See also

• Lithium battery

External links

• Web site: WebElements – Lithium Iodide . 2005-09-16.
• Web site: Composition of Lithium Iodide – NIST . 2006-02-03.

Notes and References

1. Web site: Lithium iodide . ESPI Corp. MSDS . 2005-09-16 . https://web.archive.org/web/20080309151355/http://www.espimetals.com/msds's/lithiumiodide.pdf . 2008-03-09 . dead .
2. Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. .
3. Wietelmann, Ulrich and Bauer, Richard J. (2005) "Lithium and Lithium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH: Weinheim. .
4. Holmes. C.. 2007-09-28. The Lithium/Iodine-Polyvinylpyridine Pacemaker Battery - 35 years of Successful Clinical Use. ECS Transactions. en. 6. 5. 1–7. 10.1149/1.2790382. 2007ECSTr...6e...1H. 138189063 . 1938-5862.
5. Hanif. Maryam. 2008. The Pacemaker Battery - Review Article. UIC Bioengineering Student Journal.
6. Nicholson . K. P. . etal . 1955 . Some lithium iodide phosphors for slow neutron detection . Br. J. Appl. Phys. . 6 . 3 . 104–106 . 10.1088/0508-3443/6/3/311. 1955BJAP....6..104N .
7. Charette, André B.; Barbay, J. Kent and He, Wei (2005) "Lithium Iodide" in Encyclopedia of Reagents for Organic Synthesis, John Wiley & Sons.
8. 10.1021/cr200358s. 23210836. X-ray-Computed Tomography Contrast Agents. Chemical Reviews. 113. 3. 1641–66. 2013. Lusic. Hrvoje. Grinstaff. Mark W.. 3878741.
9. 10.1007/s00216-011-4814-9. 21380605. MALDI imaging mass spectrometry of lipids by adding lithium salts to the matrix solution. Analytical and Bioanalytical Chemistry. 401. 1. 75–87. 2011. Petit. Cerruti. Touboul. Laprévote. 3878741.