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. It crystallizes in the NaCl motif. It can participate in various hydrates.
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| ECHA InfoCard | 100.030.735 |
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| 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) | |
| 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 | |
Refractive index (nD) | 1.955 |
| Thermochemistry | |
Heat capacity (C) | 54.4 J mol−1 K−1 |
Std molar entropy (S⦵298) | 75.7 J mol−1 K−1 |
Std enthalpy of formation (ΔfH⦵298) | −270.48 kJ/mol |
Gibbs free energy (ΔfG⦵) | −266.9 kJ/mol |
| Hazards | |
| NFPA 704 (fire diamond) | 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). verify (what is ?) Infobox references | |
Applications
Lithium iodide is used as a solid-state electrolyte for high-temperature batteries. It is also the standard electrolyte in artificial pacemakers due to the long cycle life it enables. The solid is used as a phosphor for neutron detection. 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:
- 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.
It is also useful in MALDI imaging mass spectrometry of lipids by adding lithium salts to the matrix solution.
See also
wikipedia, wiki, encyclopedia, book, library, article, read, free download, Information about Lithium iodide, What is Lithium iodide? What does Lithium iodide mean?