Barium iodide explained

Barium iodide is an inorganic compound with the formula BaI₂. The compound exists as an anhydrous and a hydrate (BaI₂(H₂O)₂), both of which are white solids. When heated, hydrated barium iodide converts to the anhydrous salt. The hydrated form is freely soluble in water, ethanol, and acetone.

Structure

The structure of the anhydrous form resembles that of lead(II) chloride with each Ba center bound to nine iodide ligands^[1] and has a crystalline packing structure that is quite similar to BaCl₂.^[2]

Reactions

Anhydrous BaI₂ can be prepared by treating Ba metal with 1,2-diiodoethane in ether.^[3]

BaI₂ reacts with alkyl potassium compounds to form organobarium compounds.^[4]

BaI₂ can be reduced with lithium biphenyl, to give a highly active form of barium metal.^[5]

Safety

Like other soluble salts of barium, barium iodide is toxic.

Notes and References

1. Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. .
2. Brackett, E. B.; Brackett, T. E.; Sass, R. L.; The Crystal Structures of Barium Chloride, Barium Bromide, and Barium Iodide. J. Phys. Chem., 1963, volume 67, 2132 – 2135
3. Duval, E.; Zoltobroda, G.; Langlois, Y.; A new preparation of BaI2: application to (Z)-enol ether synthesis. Tetrahedron Letters, 2000, 41, 337-339
4. Walter, M. D.; Wolmershauser, G.; Sitzmann, H.; Calcium, Strontium, Barium, and Ytterbium Complexes with Cyclooctatetraenyl or Cyclononatetraenyl Ligands. J. Am. Chem. Soc., 2005, 127 (49), 17494 – 17503.
5. Yanagisawa, A.; Habaue, S.; Yasue, K.; Yamamoto, H.; Allylbarium Reagents: Unprecedented Regio- and Stereoselective Allylation Reactions of Carbonyl Compounds. J. Am. Chem. Soc.1994, 116,6130-6141