Lithium iodide

  • Formula: LiI
  • Hill system formula: I1Li1
  • CAS registry number: [10377-51-2]
  • Formula weight: 133.845
  • Class: iodide
  • Colour: white
  • Appearance: crystalline solid
  • Melting point: 560°C; 469°C
  • Boiling point: 1171°C
  • Density: 4060 kg m-3

The following are some synonyms of lithium iodide:

  • lithium iodide
  • lithium(I) iodide

The oxidation number of lithium in lithium iodide is 1.


One way to make lithium iodide is to react the hydroxide with hydroiodic acid. The resulting salt can then be purified by recrystallization.

LiOH(aq) + HI(aq) → LiI(aq) + H2O(l)

Lithium(I) iodide can also be made by the neutralization of lithium(I) carbonate with hydroiodic acid. The resulting salt can then be purified by recrystallization.

Li2(CO3)(aq) + 2HI(aq) → 2LiI(aq) + H2O(l) + CO2(g)

While not a normal route of preparation because of the expense, lithium metal reacts vigorously with all the halogens to form lithium halides. So, it burns with iodine, I2, to form lithium(I) iodide, LiI.

2Li(s) + I2(s) → 2LiI(s)

Solid state structure

  • Geometry of lithium: 6 coordinate: octahedral
  • Prototypical structure: NaCl (rock salt)
Crystal structure of lithium iodide.
Crystal structure of lithium iodide.

Element analysis

The table shows element percentages for LiI (lithium iodide).

Element %
I 94.81
Li 5.19

Isotope pattern for LiI

The chart below shows the calculated isotope pattern for the formula LiI with the most intense ion set to 100%.


The data on these compounds pages are assembled and adapted from the primary literature and several other sources including the following.

  • R.T. Sanderson in Chemical Periodicity, Reinhold, New York, USA, 1960.
  • N.N. Greenwood and A. Earnshaw in Chemistry of the Elements, 2nd edition, Butterworth, UK, 1997.
  • F.A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann, in Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
  • A.F. Trotman-Dickenson, (ed.) in Comprehensive Inorganic Chemistry, Pergamon, Oxford, UK, 1973.
  • R.W.G. Wyckoff, in Crystal Structures, volume 1, Interscience, John Wiley & Sons, 1963.
  • A.R.West in Basic solid state chemistry Chemistry, John Wiley & Sons, 1999.
  • A.F. Wells in Structural inorganic chemistry, 4th edition, Oxford, UK, 1975.
  • J.D.H. Donnay, (ed.) in Crystal data determinative tables, ACA monograph number 5, American Crystallographic Association, USA, 1963.
  • D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
  • J.W. Mellor in A comprehensive treatise on inorganic and theoretical chemistry, volumes 1-16, Longmans, London, UK, 1922-1937.
  • J.E. Macintyre (ed.) in Dictionary of inorganic compounds, volumes 1-3, Chapman & Hall, London, UK, 1992.

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